microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 1 mikrostruktur dan karakterisasi sifat mekanik lapisan cr3c2-nial-al2o3 hasil deposisi dengan menggunakan high velocity oxygen fuel thermal spray coating edy riyanto, budi prawara pusat penelitian tenaga listrik dan mekatronik, lembaga ilmu pengetahuan indonesia komplek lipi, jl. cisitu no.21/154d, bandung, jawa barat 40135, indonesia edyr001@lipi.go.id; budi.prawara@lipi.go.id diterima: 20 juli 2010; direvisi: 17 september 2010; disetujui: 29 september 2010; terbit online: 10 oktober 2010. abstrak proses pelapisan permukaan komponen dengan menggunakan metode thermal spray telah banyak diaplikasikan di industri. pelapisan keramik matrik komposit yang terdiri dari cr3c2-nial-al2o3 telah dilakukan untuk memperoleh lapisan material yang memiliki sifat mekanik yang unggul untuk meningkatkan kinerja komponen. metode thermal spray yang digunakan adalah high velocity oxygen fuel (hvof). penelitian ini bertujuan untuk mengetahui pengaruh ukuran partikel serbuk terhadap mikrostruktur, kekasaran permukaan dan kekerasan lapisan, dengan membuat variasi ukuran partikel serbuk nial. hasil uji menunjukkan ukuran partikel serbuk nial memiliki pengaruh terhadap sifat mekanik lapisan keramik matrik komposit yang dihasilkan. semakin kecil ukuran partikel serbuk nial, nilai kekerasan lapisan cr3c2-nial-al2o3 semakin meningkat dengan nilai kekasaran permukaan yang semakin rendah. kata kunci: thermal spray coating, high velocity oxygen fuel, lapisan cr3c2-nial-al2o3. abstract surface coating processing of industrial component with thermal spray coatings have been applied in many industrial fields. ceramic matrix composite coating which consists of cr3c2-al2o3-nial had been carried out to obtain layers of material that has superior mechanical properties to enhance component performance. deposition of cmc with high velocity oxygen fuel (hvof) thermal spray coating has been employed. this study aims to determine the effect of powder particle size on the microstructure, surface roughness and hardness of the layer, by varying the nial powder particle size. test results show nial powder particle size has an influence on the mechanical properties of cmc coating. hardness of coating increases and surface roughness values of coating decrease with smaller nial particle size. key words : thermal spray coating, high velocity oxygen fuel, cr3c2-nial-al2o3 coating i. pendahuluan pelapisan dengan metode high velocity oxygen fuel (hvof) thermal spray coating menghasilkan struktur bahan yang sangat padat, porositas rendah dengan tegangan sisa tarik (residual stress) yang rendah. karena proses ini memiliki energi kinetik partikel sangat tinggi pada saat berdeposisi pada permukaan substrat, hvof cocok untuk aplikasi pelapisan permukaan yang memerlukan densitas tinggi [1]. proses ini dicirikan dengan kecepatan partikel droplet yang tinggi dan temperatur nyala api yang rendah [2]. panas pada hvof diperoleh dari hasil pembakaran campuran oksigen dengan bahan bakar gas, terutama berupa hidrogen, kerosene, propana, propylene, gas alam cair dan acetilene. dengan menggunakan desain nosel konvergen-divergen, jet nyala api hasil pembakaran dapat mencapai kecepatan supersonik yang ditandai dengan pembentukan shock diamond [3], [4]. pembakaran yang dihasilkan adalah pembakaran yang kontinyu sehingga hasil deposisi memiliki ketebalan yang seragam. pada aplikasi industri, cr3c2 , al2o3 dan tungsten carbide telah banyak dikenal sebagai material penguat yang digunakan untuk meningkatkan nilai kekerasan dan ketahanan aus dengan koefisien friksi yang rendah [5], [6]. untuk membentuk struktur lapisan yang memiliki densitas yang tinggi, material yang berfungsi sebagai pengikat partikel penguat berfasa padat diperlukan. karakter serbuk partikel tersebut memiliki temperatur lebur yang lebih rendah daripada material penguat. material pengikat yang digunakan dapat berupa nikel, khrom, kobalt dan aluminium [2]. mikrostruktur dan karakterisasi sifat mekanik lapisan cr3c2-nial-al2o3 hasil deposisi dengan menggunakan high velocity oxygen fuel thermal spray coating (edy riyanto, budi prawara) pp.1-4 2 tujuan dari penelitian ini adalah untuk memperoleh lapisan permukaan yang memiliki nilai kekerasan permukaan yang tinggi dengan nilai kekasaran yang rendah. modifikasi lapisan permukaan dilakukan dengan menggunakan serbuk cr3c2 dan al2o3 sebagai material penguat dan serbuk nial sebagai material pengikat. untuk mengetahui pengaruh ukuran partikel serbuk terhadap sifat mekanik lapisan, ukuran serbuk nial divariasikan. ii. metodologi penelitian bahan yang digunakan sebagai substrat adalah baja karbon menengah s45c berukuran 50 x 40 x 3 mm. baja jenis ini memiliki nilai kekerasan microhardness sebesar 138 hv. alat yang digunakan untuk proses pelapisan adalah hvof gun spray dengan tipe hipojet-2700. udara bertekanan digunakan sebagai pendingin hvof gun spray. propana digunakan sebagai bahan bakar pembentuk nyala api berkecepatan tinggi. komposisi perbandingan berat campuran serbuk cr3c2-nial-al2o3 adalah 60-30-10 %. parameter yang digunakan pada proses penyemprotan ditunjukkan pada tabel 1. tabel 1. parameter proses penyemprotan. parameter hp2700 kecepatan alir oksigen (lt/min) 271 kecepatan alir bahan bakar (lt/min) 62,4 kecepatan alir gas pembawa (lt/min) 8 tekanan gas pembawa (bar) 5 tekanan oksigen (bar) 8 tekanan bahan bakar (bar) 5 bahan bakar propana sebelum proses spraying permukaan substrat dikasarkan dengan menggunakan blasting yang memiliki diameter nosel 3 mm. bahan blasting yang digunakan adalah steel grit berukuran mesh 24. jarak antara ujung nosel dan permukaan substrat 15 cm. mikrostruktur potongan melintang lapisan cr3c2-nial-al2o3 di amati dengan menggunakan scanning electron microscopy (sem). nilai kekerasan lapisan diukur dengan menggunakan indentasi vicker’s berbeban 200 g. masing-masing spesimen dilakukan proses indentasi sebanyak 5 titik mengikuti standard jis h8666. untuk mengetahui pengaruh penggunaan ukuran partikel terhadap kekasaran permukaan, uji kekasaran dilakukan dengan menggunakan surftest sj-301 (mitutoyo). iii. hasil dan diskusi a. mikrostruktur lapisan hasil deposisi dengan menggunakan hvof thermal spray coating menunjukkan ikatan mekanik (mechanical bonding) antara ceramic matrix composite dengan medium carbon steel substrate seperti ditunjukkan pada gambar 1. lapisan oksida tidak terbentuk pada interface coating dengan substrat, hal ini menunjukkan bahwa stochiometri pembakaran campuran propane dan oksigen yang baik dan temperatur substrat yang selalu terjaga di bawah 150 ºc. gambar 1. sem micrograph potongan melintang cmc coating. mikrostruktur dari potongan penampang lintang lapisan cr3c2-nial-al2o3 dengan berbagai ukuran reinforced nial partikel ditunjukkan pada gambar 2. hasil deposisi dengan menggunakan hvof thermal spray coating menunjukkan ikatan yang kuat antar lamella (interlamella contact) dan tidak ada crack (retak) yang terbentuk diantara lamella. perbedaan unsur pada coating dapat dilihat dengan menggunakan perbedaan skala warna kelabu (gray scale) hasil dari backscattered image. warna hitam menunjukkan porositas dari coating serta unsur cr, ni, dan al berturut-turut sesuai dengan degradasi ke warna kelabu yang lebih muda. porositas dari coating dapat berpengaruh pada sifat mekanik seperti kekerasan [7]. semakin tinggi persentase porositas lapisan maka kekerasan akan menurun demikian pula sebaliknya lapisan dengan densitas yang semakin tinggi akan memiliki kekerasan yang semakin tinggi pula. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 3 gambar 2. mikrostruktur lapisan cr3c2-nial-al2o3 dengan variasi ukuran partikel serbuk nial, (a) mesh 120, (b) mesh 200, (c) mesh 270, (d) mesh 400. b. kekerasan lapisan gambar 3. pengaruh ukuran partikel nial terhadap kekerasan lapisan cr3c2-nial-al2o3. bahan substrat yang digunakan pada proses pelapisan cr3c2-nial-al2o3 adalah baja karbon menengah dengan kekerasan 138 hv. dengan dilapisi cr3c2-nial-al2o3 menggunakan metode hvof thermal spray, nilai kekerasan dapat di tingkatkan sampai dengan 925 hv. gambar 3 menunjukkan pengaruh ukuran partikel nial terhadap nilai kekerasan lapisan cr3c2-nialal2o3. semakin kecil ukuran partikel nial, nilai kekerasan lapisan semakin meningkat. hal ini disebabkan oleh pengaruh dari kondisi melting dari partikel pada saat menumbuk substrat membentuk lapisan coating. semakin besar ukuran partikel serbuk nial, semakin besar nilai fraksi volume partikel yang tidak lebur, sehingga daya ikat antara partikel penguat semakin rendah. daya ikat yang rendah akan mengakibatkan nilai kekerasan lapisan yang rendah. kondisi tersebut juga menyebabkan ruang kosong di antara partikel-partikel yang tidak meleleh membentuk porositas [6]. c. kekasaran permukaan lapisan gambar 4 menunjukkan hubungan ukuran partikel serbuk yang digunakan terhadap kekasaran rata-rata permukaan lapisan yang terbentuk. semakin kecil ukuran partikel nial, nilai rata-rata kekasaran permukaan lapisan semakin rendah. gambar 4. pengaruh ukuran partikel nial terhadap kekasaran permukaan lapisan. 0 100 200 300 400 500 600 700 800 900 1000 0 100 200 300 400 500 k ek er as an (h v) ukuran partikel nial (mesh) 0 2 4 6 8 10 0 100 200 300 400 500 k ek as ar an ra ta -r at a (r a) (µ m ) ukuran partikel nial (mesh) (b) (d)(c) oksida cr3c2 (a) nial mikrostruktur dan karakterisasi sifat mekanik lapisan cr3c2-nial-al2o3 hasil deposisi dengan menggunakan high velocity oxygen fuel thermal spray coating (edy riyanto, budi prawara) pp.1-4 4 hal ini menunjukan bahwa semakin rendah nilai kekasaran, permukaan lapisan semakin halus. fenomena ini dimulai dari proses awal pembentukan droplet pada saat masing-masing partikel menyerap energi panas nyala api. partikel yang besar cenderung membentuk droplet dalam ukuran besar dengan tingkat volume partikel yang meleleh yang rendah atau leleh sebagian [8]. droplet dengan kondisi tersebut akan menumbuk substrat membentuk lamella dalam ukuran yang besar. tumpukan lamella berukuran besar akan membentuk lapisan yang memiliki nilai kekasaran permukaan yang tinggi. sedangkan partikel yang memiliki ukuran kecil akan mudah untuk meleleh penuh membentuk droplet cair dan berdeposisi ke arah samping membentuk lapisan yang memiliki permukaan yang halus [8], [9]. sesaat setelah droplet menumbuk substrat akan terbentuk splat dengan ketebalan yang sangat dipengaruhi oleh kecepatan pergerakan droplet sesaat sebelum berdeposisi. ketebalan splat berkurang dengan bertambahnya kecepatan droplet dan sebaliknya. faktor kondisi lebur partikel juga berpengaruh terhadap proses pembentukan splat. meningkatnya fraksi volume fasa padat droplet menyebabkan ketebalan splat meningkat dengan ukuran radius splat yang semakin pendek [2]. splat yang tebal akan membentuk lamella berukuran tebal dengan diameter yang pendek. tumpukan lamella-lamella dengan kondisi tersebut membentuk permukaan lapisan dengan nilai kekasaran yang tinggi. iv. kesimpulan deposisi lapisan keramik matrik komposit (ceramic matrix composite) berbasis chrome carbide dengan partikel penyisip nial yang memiliki variasi ukuran telah dilakukan menggunakan high velocity oxygen fuel (hvof) thermal spray coating. hasil-hasil yang didapat dari kegiatan/penelitian ini dapat disimpulkan sebagai berikut : a. nilai kekasaran permukaan lapisan cr3c2nial-al2o3 dipengaruhi oleh ukuran partikel serbuk, fraksi volume fasa padat droplet, ketebalan dan radius splat yang terbentuk. b. berkurangnya ukuran partikel serbuk yang digunakan pada lapisan cr3c2-nial-al2o3 menyebabkan nilai kekerasan meningkat dengan nilai kekasaran permukaan lapisan yang semakin rendah. ucapan terima kasih penulis mengucapkan terima kasih kepada semua teknisi puslit telimek lipi yang telah membantu kegiatan penelitian ini. penelitian ini merupakan bagian dari penelitian kompetitif lipi tahun 2010. daftar pustaka [1] m. magnani, p.h. soegama, n. espallargas, c.s. fugivara, s. dosta, j.m. guilemany, and a.v. benedetti, corrosion and wear studies of cr3c2-nicr-hvof coatings sprayed on aa7050 t7 under cooling, journal of thermal spray technology, march 2009. [2] j. he, m. ice and e. lavernia, particle melting behaviour during high velocity oxygen fuel thermal spraying, journal of thermal spray technology, vol 10(1), 2001, pp. 83-93. [3] e. turunen, diagnostic tools for hvof process optimization, dissertation for the degree doctor of science, helsinki university of technology, espoo, finland, 2005. [4] k.w. david hart, d.h. harper, m.j. gill and g.r. heath, case studies in wear resistance using hvof, ptaw and spray fusion surfacing, eutectectic canada inc., edmonton, alberta, canada. [5] d.e. wolfe, t.j. eden, j.k. potter and a.p. jaroh, investigation and characterization of cr3c2 – based wear-resistant coatings applied by the cold spray process, journal of thermal spray technology, vol 15(3), 2006, pp. 400412. [6] g.-j. ji, c.-j. li, y.-y. wang and w.-y. li, erotion performance of hvof-sprayed cr3c2-nicr coatings, journal of thermal spray technology, vol 16(4), 2007, pp. 557-565. [7] c.-j. li, y.-y. wang, effect of particle state on the adhesive strength of hvof sprayed metallic coating, journal of thermal spray technology, vol 11(4), 2002, pp. 523529. [8] v.v.sobolev, j.m.guilemany, and a.j.martin, flattening of composite powder particles during thermal spraying, journal of thermal spray technology, vol 6(3), 1997, pp. 353360. [9] r.s.neiser, m.f.smith, and r.c.dykhuizen, oxidation in wire hvofsprayed steel, journal of thermal spray technology, vol 7(4), 1998, pp. 537-545. mev mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.75-80 design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter moh. zaenal efendi a,*, novie ayub windarko a, m. faisal amir a adepartment of electrical engineering, politeknik elektronika negeri surabaya, kampus pens, keputih sukolilo, surabaya received 18 october 2013; received in revised form 14 november 2013; accepted 15 november 2013 published online 24 december 2013 abstract this paper presents a design and implementation of a converter which has a high power factor for battery charger application. the converter is a combination of a sepic converter and a full-bridge dc-dc converter connected in two stages of series circuit. the sepic converter works in discontinuous conduction mode and it serves as a power factor corrector so that the shape of input current waveform follows the shape of input voltage waveform. the full-bridge dc-dc converter serves as a regulator of output voltage and operates at continuous conduction mode. the experimental results show that the power factor of this converter system can be achieved up to 0.96. keywords: sepic converter, full-bridge dc-dc converter, discontinuous conduction mode, power factor correction, battery charger. i. introduction most of modern electronic applications are equipped with battery which works as energy storage. battery charger can be developed using conventional diode rectifier. however, this type of rectifier produces harmonics and low power factor. the harmonics and power factor are recognized as sources of disturbance in power quality issues. many researchers have been conducting research to develop rectifiers having low harmonics and high power factor. furthermore, the rectifier should produce low output voltage ripple to reduce losses in battery charger. several methods for reducing high harmonics and improving power factors of rectifier circuit above have been proposed in several ways, such as installing passive filter and power factor correction (pfc) converter. some researchers have proposed to install a passive filter by using an inductor on the system [1]. however, this solution may increase the size and the weight of the rectifier which operates in low frequency of 50–60 hz. some other researchers have proposed power factor correction converter to increase the power factor of ac-dc conversion. this system can be developed by two stage power factor correction converter which commonly uses preregulator buck [2,9], pre-regulator boost [5,8], pre-regulator buck-boost [3,4], and others [6,10,11,12]. this paper proposes a high power factor battery charger. the charger consists of combination of two converters connected in two stages of series circuit. the series converters are sepic converter and full-bridge dc-dc converter. the block diagram of the proposed converter system is shown in figure 1. ii. circuit configuration one of the methods for improving low power factor is to install a sepic converter as a power factor corrector. the sepic converter is series connected to a full bridge dc-dc converter in two stages which is shown in figure 2. the sepic converter is operated in discontinuous conduction mode so that it will have a high power factor and operate as a voltage follower. * corresponding author. e-mail: zen@eepis-its.edu / zenefendi@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.75-80 m. z. efendi et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 76 this operation principle means that the input current waveform follows the input voltage waveform [5]. thus, the power factor will be close to unity. the circuit of sepic converter in figure 3 consists of two inductors (i.e., the first inductor is in input (l1) and the second inductor is in output (l2)). it operates in discontinuous conduction mode and is used to improve the power factor. the shape of input current waveform, which is shown in figure 4, is represented by l1’s current. by assuming the output current (io), the input current ( ii) is determined in equation 1 [6]. ditv l td ti otii ⋅+⋅ ⋅ = ωsin 2 )( )( 1 2 (1) where d is duty cycle, t is the switching period, vi is the input voltage and io is the output current. according to equation 1, the sepic converter is operated in discontinuous conduction mode and in constant duty cycle, then the current ii(t) follows the shape of input voltage waveform and it means the sepic converter acts as a pfc converter. to obtain the function of pfc, sepic converter is designed to operate in discontinuous conduction mode with the following steps [6]. assume that m is ratio of the output voltage ( ov ) and the input voltage ( iv ), then: 𝑀𝑀 = 𝑉𝑉𝑜𝑜 𝑉𝑉𝑖𝑖 (2) ka is conduction parameter and ka,crit is critical conduction parameter which are determined by: 𝐾𝐾𝑎𝑎,𝑐𝑐𝑐𝑐𝑖𝑖𝑐𝑐 = 1 2(𝑀𝑀)2 (3) which ka<ka,crit. then 𝐷𝐷 = √2 ∙ 𝑀𝑀 ∙ �𝐾𝐾𝑎𝑎 (4) the values of l1 and l2 which operate in discontinuous mode are determined by using equation 5 and equation 6. 𝐿𝐿1 = 𝑉𝑉1 ∙ 𝐷𝐷 ∙ 𝑇𝑇 𝐼𝐼𝑐𝑐𝑖𝑖𝑟𝑟 (5) and l2 can be obtained from ac-dc full-wave rectifier sepic converter (pfc converter) dc-dc fullbridge converter (dc regulator) load figure 1. block diagram of sepic converter and fullbridge dc-dc converter connected in series circuit vs ci cs d1 i s q 1 li l1 c1 l2 c2 q2 q4 q3 q5 l3 co r d2 d4 d3 d5 tr figure 2. circuit of a sepic converter and a full-bridge dc-dc converter connected in the two stage of series circuit cs d1 q1 l1 c1 l2vi(t) ci ii li c2 r ioil1 figure 3. circuit of sepic converter dt t t t il d1t io 1 figure 4. inductor current and output current m. z. efendi et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 77 𝐿𝐿2 = 𝐿𝐿1𝐿𝐿𝑒𝑒𝑒𝑒 𝐿𝐿1−𝐿𝐿𝑒𝑒𝑒𝑒 (6) the equivalent inductance leq from both inductors can be determined as: 𝐿𝐿𝑒𝑒𝑒𝑒 = 𝑅𝑅 ∙ 𝑇𝑇 ∙ 𝐾𝐾𝑎𝑎 2 (7) where r is resistive load and irip is peak to peak of input current. the intermediate capacitor c1 is determined by assuming that resonant frequency of c1, l1, and l2 must be higher than the fundamental frequency. therefore, the resonant frequency of c1 and l2 must be lower than the switching frequency [10]. the value of c1 can be obtained from: 𝐶𝐶1 = 1 𝜔𝜔𝑐𝑐 2 (𝐿𝐿1 +𝐿𝐿2 ) (8) furthermore, the full-bridge dc-dc converter which is shown in figure 5 serves as dc voltage regulator. it is designed in normal operation which consider to equation 9 to equation 11. assume that d is duty cycle, then: 𝑑𝑑 = 𝑁𝑁1𝑥𝑥 𝑉𝑉𝑜𝑜 2 𝑥𝑥 𝑁𝑁2𝑥𝑥 𝑉𝑉𝑖𝑖𝑖𝑖 (9) the filter inductor can be obtained from: 𝐿𝐿𝑐𝑐𝑐𝑐𝑖𝑖 = (1−𝑑𝑑) 4 𝑥𝑥 𝑅𝑅 𝑇𝑇 (10) and, the filter capacitor is 𝐶𝐶𝑜𝑜 = (1 − 𝑑𝑑)𝑥𝑥 𝑉𝑉𝑜𝑜 32 𝐿𝐿𝑜𝑜𝑓𝑓2 ∆𝑉𝑉𝑜𝑜 (11) iii. implementation and experiment to verify the design that has already been discussed, the converter system was built using the following parameters which are shown in table 1 and table 2. the above parameters are designed parameters for the converter to deliver unity power factor and to verify the function of battery charger. in this experiment, a conventional rectifier and a sepic converter are compared to verify the effectiveness of the design criteria. first test was done by providing 120 vdc from full wave rectifier to full-bridge converter. the observed parameters are input current, harmonic spectrum, power factor and performance of full-bridge dc-dc converter. figure 6 shows the values of the input current waveform, and the harmonic spectrum of input current and figure 7 shows the value of power factor. data in this experiment was obtained using fluke 41b. by providing dc voltage source of 120 v from full wave rectifier, the experimental results show that the system has a low power factor (0.69) and high harmonic distortion of 70.8% of thd. second experiment system was done using the proposed system as shown in figure 2. figure 8 shows the values of the input current waveform, and the harmonic spectrum of input current and figure 9 shows the value of power factor. the experimental results verify that the converter system has high power factor of 0.96 and harmonic distortion decreases to 24.2% of thd. q2 q4 q3 q5 l3 co r d2 d4 d3 d5 tr vin figure 5. fullbridge dc-dc converter circuit table 2. parameters of full-bridge dc-dc converter parameter value input voltage 120 volt switching frequency 25 khz inductor l3 860 μh diode d2, d3, d4, d5 (ultra fast recovery diode) stth 1b0l0bcwg switch q2-5 igbt transformer tr n11:n12= 48:43 capacitor co 86 μf ,450 volt table 1. parameters of sepic converter parameter value ac input voltage 220 volt output voltage 120 volt switching frequency 25 khz inductor l1 2.6 mh inductor l2 83 μh diode d1 (ultra fast recovery diode) stth 1b0l0bcwg switch q1 igbt capacitor c1 2 μf,1000 volt capacitor c2 680 μf,450 volt m. z. efendi et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 78 table 3 shows the experiment data of varying load and pfc results. this experiment is done by operating the proposed system with input ac voltage source of 220 v. the load is increased by around 0.5 a step. the converter can deliver power factor up to 0.96 which is close to unity. the largest power factor is 0.96 when the output current is 3.14 a. these results verify that the converter can be operated as pfc. furthermore, figure 10 shows the value of the power factor according to load and shows the trends of data in table 3. overall hardware experimental results obtained a high power factor. based on data above, the correction of power factor is achieved from 0.69 to 0.96. after the experiment of pfc had already done, then characteristic of battery charging were going to be observed. there are two parameters which must be concerned about battery charging. the first parameter is the charging current and it should be kept to around 10% to 30% of the capacity of the battery (ah: ampere-hours) and the second parameter is the charging voltage and it should be set to 2.3 2.4 volt per 2 volt cell. for example a 12 volt battery (6 cells of 2 volt) is charged at 6 × 2.3 = 13.8 volt to at 6 × 2.4 = 14.4 volt. the battery used for this experiment has a 72 volt of voltage that consists of 6 pieces of 12 volt of battery or 36 cells of 2 volt. the capacity of battery that is used for this experiment is 20 ah (ampere-hours). so, to meet the requirement of charging voltage and charging current, the output voltage of converter system is adjusted at 87 volt (36 cells times 2.4 volt) and produces the charging current about 3.14 a or 10% of the capacity. charging characteristic is shown in figure 11. according to this figure we know that the battery charger can work well. figure 6. input current waveform and its parameter analysis of conventional rectifier figure 7. power analysis of conventional rectifier figure 8. input current waveform and its parameter analysis of sepic converter figure 9. power analysis of sepic converter table 3. overall systems performance vin (v) iin (a) vo (v) io (a) pf 217 0.54 87 0.56 0.87 218 0.83 87 1.13 0.94 220 1.32 87 1.68 0.95 218 1.71 87 2.15 0.96 216 2.33 87 2.8 0.96 220 2.48 87 3.14 0.96 m. z. efendi et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 79 iv. conclusion this paper has already discussed about the design and implementation of a combination of sepic converter and full bridge dc-dc converter for battery charger application with power factor correction. the experimental results have confirmed that this converter provides high power factor correction up to 0.96. this converter can be used for battery charger application such as electric vehicle and electronic appliances. acknowledgement this research was funded by research unit of politeknik elektronika negeri surabaya (pens) to energy and transportation research centre, budgeting year of 2013. we would thank chairman and staff of research unit of pens for supporting to publish this paper. references [1] a. w. kelly, “rectifier design for minimum line-current harmonics and maximum power factor,” ieee transaction on power electronics, vol.7, no.2, april, 1992. [2] h. endo, t. yamashita, t. sugiura, ”a high power factor buck converter,” in proceedings of ieee applied power electronics conference, 1992. [3] m. c. ghanem, k. al-haddad, g. roy, “a new single phase buck-boost converter with unity power factor,” in conference record of the 1993 ieee industry applications society annual meeting, ias’93, pp. 785-792, 1993. [4] y.m. jiang, f.c. lee, “a new control scheme for buck+boost power factor correction circuit,” in proceedings of the virginia power electronics seminar, 1993, pp. 189-193. figure 10. chart of pf vs output current figure 11. characteristic of battery charging 0.7 0.75 0.8 0.85 0.9 0.95 1 0.56 1.13 1.68 2.15 2.8 3.14 pf iout (a) 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 0 1. 32 2. 64 3. 96 5. 28 6. 6 7. 92 9. 24 10 .5 6 11 .8 8 13 .2 14 .5 2 15 .8 4 17 .1 6 18 .4 8 19 .8 21 .1 2 22 .4 4 23 .7 6 25 .0 8 26 .4 27 .7 2 29 .0 4 ch ar gi ng c ur re nt (a ) charging time (minute) m. z. efendi et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 75-80 80 [5] d.maksimovic, r.w erickson, ”universal input, high power factor boost doubler rectifiers,” in proceedings of ieee applied power electronics conference, 1995. [6] d. s. l. simonetti, j. sebastian, j. uceda, ”the discontinuous conduction mode sepic and cuk power factor preregulators: analysis and design,” ieee transaction on industrial electronics, vol.4, no.5, october, 1997. [7] h. wei, “comparison of basic converter topologies for power factor correction,” in proceedings of ieee, southeastcon, 1998. [8] m.gotfryd, ”output voltage and power limits in boost power factor corrector operating in discontinuous inductor current mode,” ieee transaction on power electronics, vol.15, no.1, january 2000. [9] g. spiazzi, s. buso, “power factor preregulators based on combined buck flyback topologies,” ieee transaction on power electronics, vol.15, no.2, march 2000. [10] j. falin, “designing dc/dc converter based on sepic topology,” texas instruments incorporated, 2008. [11] m. z. efendi, n. ayub, h. oktavianto, ”design and implementation of ac-dc double series flyback power factor correction (pfc) converter,” emitter journal, vol.1 no.1, politeknik elektronika negeri surabaya, 2010. [12] m. z. efendi, “single stage hybrid power factor correction (pfc) converter,” in proceedings of industrial electronics seminar, pens, surabaya, 2010. introduction circuit configuration implementation and experiment conclusion acknowledgement references microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 69 ra�ca�g ba�gu� ke�dali sekue� u�tuk sambu�ga� jala-jala listrik me�ggu�aka� cycloco�verter yuliadi erdani, aris eko setiyawan, maulana aria pratama jurusan teknik otomasi manufaktur dan mekatronika politeknik manufaktur negeri bandung jl. kanayakan no. 21 bandung jawa barat 40275, indonesia yul_erdani@yahoo.com; yul_erdani@polman-bandung.ac.id diterima: 27 oktober 2010; direvisi: 10 desember 2010; disetujui: 21 desember 2010; terbit online: 24 desember 2010. abstrak rangkaian cycloconverter yang dikembangkan pada penelitian ini mensimulasikan rangkaian koneksi ke jalajala listrik dua buah function generator sebagai pengganti sumber tegangan ac-nya. function generator pertama digunakan sebagai pengganti gelombang masukan pembangkit pln dengan referensi frekuensi 50hz. function generator kedua digunakan sebagai pengganti gelombang masukan pembangkit baru dengan referensi frekuensi mulai dari 10hz sampai dengan 90hz. dengan inisialisasi kondisi frekuensi seperti itu, maka dimungkinkan perubahan frekuensi berupa penaikkan frekuensi dari 10hz – 40hz menjadi 50hz dan penurunan frekuensi dari 60hz – 90hz menjadi 50hz. rangkaian cycloconverter ini menggunakan rangkaian trigger untuk mengaktifkan komponen elektronikanya. rangkaian trigger tersebut meliputi rangkaian trigger penyulutan thyristor dan rangkaian trigger pengaktifan mosfet. semua perangkat keras pada rangkaian ini dikendalikan oleh mikrokontroler atmega 8535 yang mengatur kerja dari rangkaian-rangkaian trigger yang dibutuhkan oleh cycloconverter. hasil pengujian menunjukkan bahwa simulasi rangkaian cycloconverter ini dapat mengubah frekuensi, dan menyamakan sudut fasa pada jaringan listrik. hal ini menunjukan bahwa cycloconverter yang dikembangkan memungkinkan untuk koneksi ke jala-jala listrik. kata kunci: cycloconverter, koneksi jala-jala listrik, elektronika daya. abstract this developed cycloconverter circuit simulates grid connector circuit using two function generators, which substitute ac power. the first function generator was used to represent input wave from pl� with 50 hz frequency. the other function generator was used to represent input wave from new generator with 10-90 hz frequency. such initial condition enabled us to control the frequency increase from 10hz – 40hz to 50hz and decrease from 60hz – 90hz to 50hz. this cycloconverter used trigger circuit to activate its electrical components. the trigger circuit contains trigger parts such as thyristor and mosfet. all hardware components in this circuit were controlled by microcontroller atmega 8535. this controller manages all trigger circuits that were needed by cycloconverter. the experiment result shows that the cycloconverter was able to modify frequency and phase angle, so that it enabled the connection to the electrical grid. key words: cycloconverter, electrical grid connection, power electronic. i. pe�dahulua� dikarenakan sumber daya listrik yang terbatas maka sering dilakukan pemadaman listrik secara bergilir oleh pln sebagai perusahaan milik negara yang menyediakan energi listrik. hal inilah yang membuat pln membuka peluang bagi masyarakat indonesia yang ingin membantu menambah daya listrik untuk memperbesar pendistribusian daya listrik. penambahan daya listrik pln tersebut dapat dilakukan dengan cara memparalelkan jaringan listrik pln dengan pembangkit listrik baru. untuk dapat menghubungkan pembangkit listrik baru dengan sistem maka harus dilakukan sinkronisasi antara pembangkit listrik baru tersebut dengan pln [1][2]. syarat sinkronisasi adalah tegangan masukan dari pembangkit listrik baru harus sama dengan tegangan jaringan, frekuensi masukan dari pembangkit listrik baru harus sama dengan frekuensi jaringan, demikian juga dengan fasanya, pembangkit listrik baru dengan jaringan harus satu fasa. oleh karena itu dibutuhkan sebuah alat untuk menghubungkan jaringan listrik pln dengan pembangkit baru [1] [3] [4]. tujuan makalah ini adalah untuk melaporkan hasil pembuatan rangkaian cycloconverter yang mensimulasikan rangkaian koneksi ke jala-jala listrik dengan menggunakan dua buah function generator sebagai pengganti sumber tegangan ac-nya. function generator pertama digunakan sebagai pengganti gelombang masukan rancang bangun kendali sekuen untuk sambungan jala-jala listrik menggunakan cycloconverter (yuliadi erdani, aris eko setiyawan, maulana aria pratama) pp. 69-74 70 pembangkit pln, sedangkan function generator kedua digunakan sebagai pengganti gelombang masukan pembangkit baru. ii. isi makalah untuk menunjang penelitian ini dibutuhkan peralatan berupa solder, alat ukur (osciloscope, voltmeter, frekuensi meter dan cycloconverter) dan peralatan mekanis untuk membuat penutup dari panelnya. selain itu juga dibutuhkan perangkat lunak yang mempunyai kemampuan untuk membuat desain skematik rangkaian elektronika. sedangkan bahannya berupa printed circuit board (pcb) double layer, komponen transistor-transistor logic (ttl berisi dioda, resistor, kapasitor, trimpot, dan lainnya), vertinax dan box cover. tahap persiapan meliputi pencarian data dan bahan mengenai cycloconverter dan data mengenai rangkaian trigger untuk cycloconverter, dilakukan dengan cara berselancar di internet, membaca buku literatur dan diskusi. pada bagian ini dijelaskan mengenai tahapan/proses pengembangan cycloconverter, terlihat pada gambar 1. tahap pertama peneliti melakukan analisis situasi yang bersumber dari lapangan dan literatur, dan mendefinisikan kebutuhan yang harus dipenuhi oleh sistem yang akan dibangun. tahap berikutnya peneliti membuat perencanaan sistem berdasarkan hasil tahap sebelumnya. selanjutnya peneliti menerjemahkan perencanaan system ke dalam konsep rancangan alat baik perangkat lunak maupun perangkat keras, yang di dalamnya diturunkan menjadi peralatan dan bahan serta perancangan peralatan itu sendiri. tahap berikutnya adalah implementasi hasil rancangan dalam bentuk pembuatan alat. di dalam proses pembuatan alat, senantiasa dilakukan uji coba parsial. gambar 1. skema tahap-tahap proses perancangan. pada rancangan sistem untuk pembangkit baru menggunakan regulator ac 50 hz agar tegangan yang masuk ke dalam cycloconverter dapat dikontrol dan pembangkit lama menggunakan function generator (gfg-8219a, spesifikasi terlampir), sebagai referensi frekuensi 50 hz. gambar 2 menunjukan arsitektur sistem yang dikembangkan. gambar 2. arsitektur sistem. agar keluaran tegangan keluaran dari cycloconverter dapat diatur maka digunakanlah thyristor bertipe 25ria120. hal yang dimanfaatkan dari thyristor ini adalah penyulutan tegangannya dimana besarnya tegangan yang disulut dapat diatur dengan mengatur sudut penyulutan dari thyristor dari mikrokontroler. untuk mengatur besarnya frekuensi yang akan dihasilkan oleh cycloconverter maka digunakanlah metal–oxide–semiconductor field-effect transistor (mosfet), dengan tipe irf634. hal yang dimanfaatkan dari mosfet ini adalah waktu pengaktifan dari masing-masing mosfet tersebut. gambar 3 menunjukkan rangkain mosfet dan thyristor dalam cycloconverter. gambar 3. rangkaian cycloconverter menggunakan thyristor dan mosfet. rangkaian cycloconverter terdiri dari dua buah rangkaian penyearah gelombang penuh dengan menggunakan thyristor. satu rangkaian penyearah pertama berfungsi sebagai penghasil gelombang positif dan satu rangkaian lagi journal of mechatronics, electrical power vol. 01, �o 2, 2010 berfungsi sebagai penghasil gelombang negatif [6]. besarnya waktu (dalam satuan ms) penyalaan antar kedua penyearah ini dapat mempengaruhi kerapatan suatu gelombang yang akan dihasilkan dan mengakibatkan terjadinya perubahan nila dari frekuensi. untuk itu digunakan sebagai sakelar otomatis yang mengatur waktu pengaktifan dari kedua penyearah ini. yang digunakan pada pembuatan alat ini adalah thyristor bertipe 25ria. thyristor mengurangi tegangan pada sebuah dengan mengatur sudut penyulutan sendiri [8]. untuk mengatur sudut penyulutan thyristor tersebut, maka perlu dibuat sebuah rancangan rangkaian yang mampu memberikan trigger pada kaki gate dari thyristor pulsa dengan keluaran arus yang mencukupi untuk men-trigger thyristor tersebut. langkah langkah atau bagaimana cara rangkaian cycloconverter ini bekerja dalam mengubah suatu frekuensi menjadi frekuensi yang baru sesuai dengan yang diinginkan, dapat dilihat pada untuk men-trigger thyristor gelombang pulsa dengan besar arus tertentu. besar arus trigger thyristor tersebut bergantung pada spesifikasi dari thyristor yang digunakan, untuk rancangan ini thyristor bertipe 25ria yang kaki gate-nya dapat ditrigger dengan minimal arus sebesar 60 ma. pembuatan rangkaian trigger thyristor ini menggunakan mikrokontroler sebagai pembangkit pulsa yang nantinya digunakan untuk mengatur sudut penyulutan pada thyristor, terlihat pada arus keluaran mikrokontroler dikua optocoupler ltv-4n35 [7]. keluaran dari optocoupler ditempatkan pada kaki emitornya sehingga terjadi penguatan arus pada pulsa. selain berfungsi sebagai penguat arus ic ltv 4n35 tersebut berfungsi sebagai pengaman/isolator antara rangkaian elektronika dengan rangkaian mikrokontroler. gambar 4. rangkaian penyulutan of mechatronics, electrical power, and vehicular technology berfungsi sebagai penghasil gelombang negatif . besarnya waktu (dalam satuan ms) penyalaan antar kedua penyearah ini dapat mempengaruhi kerapatan suatu gelombang yang akan dihasilkan dan mengakibatkan terjadinya perubahan nilai dari frekuensi. untuk itu digunakan mosfet otomatis yang mengatur waktu pengaktifan dari kedua penyearah ini. thyristor yang digunakan pada pembuatan alat ini adalah thyristor dapat mengurangi tegangan pada sebuah gelombang dengan mengatur sudut penyulutan thyristor itu . untuk mengatur sudut penyulutan tersebut, maka perlu dibuat sebuah aian yang mampu memberikan thyristor yang berupa pulsa dengan keluaran arus yang mencukupi tersebut. langkahlangkah atau bagaimana cara rangkaian ini bekerja dalam mengubah suatu frekuensi menjadi frekuensi yang baru sesuai dengan yang diinginkan, dapat dilihat pada [9]. ristor diperlukan gelombang pulsa dengan besar arus tertentu. tersebut bergantung yang digunakan, yang digunakan nya dapat ditrigger gan minimal arus sebesar 60 ma. pembuatan ini menggunakan mikrokontroler sebagai pembangkit pulsa yang nantinya digunakan untuk mengatur sudut , terlihat pada gambar 4. arus keluaran mikrokontroler dikuatkan oleh ic . keluaran dari ic ditempatkan pada kaki emitornya sehingga terjadi penguatan arus pada pulsa. bagai penguat arus ic ltv4n35 tersebut berfungsi sebagai pengaman/isolator antara rangkaian elektronika dengan rangkaian mikrokontroler. 4. rangkaian penyulutan thyristor. gambar 5. rangkaian trigger transistor tip41c dalam rangkaian ini berfungsi sebagai sakelar menghubungkan antara rangkaian keluaran dari ic optocoupler dengan rangkaian trafo pulsa transistor tipe tip41c ini transistor ini telah terbukti tangguh robotika dan mikrokontroler, transistor ini sudah dibuktikan tangguh, baik sebagai sak otomatis maupun sebagai penguat. hasil dari pengolahan pulsa yang dikeluarkan melalui trafo pulsa yang nantinya akan menjadi pulsa trigger penyulutan thyristor. penggunaan trafo pulsa pada rangkaian ini juga berfungsi sebagai pengisolasi antara rangkai rangkaian elektronika daya sehingga ketika terjadi arus balik dari tegangan ac yang berlebih maka trafo pulsa saja yang akan rusak terlebih dahulu. berbeda dengan thyristor gate-nya harus di-trigger tertentu, maka untuk mendilakukan dengan memberikan tegangan dengan besar tertentu, terlihat pada yang digunakan pada rangkaian ini adalah mosfet bertipe irf634. penggunaan tipe irf634 ini dilatarbelakangi karen masukan yang digunakan adalah sebesar 220 vac dan tegangan (vds) yang diberikan kepada mosfer irf634 ini maksimal 250 volt. tegangan maksimal untuk men-trigger irf634 ini adalah ±20 volt. karena mikrokontroler hanya mampu memberikan tegangan keluaran sebesar ± 5 volt maka dari itu pada rangkaian ini digunakanlah ltv-4n35 dengan keluarannya ditempatkan pada kaki kolektor dari ic optocoupler iss� 2087-3379 71 rangkaian trigger mosfet. transistor tip41c dalam rangkaian ini sakelar otomatis yang menghubungkan antara rangkaian keluaran dari dengan rangkaian trafo pulsa [7]. transistor tipe tip41c ini digunakan karena telah terbukti tangguh di dunia robotika dan mikrokontroler, transistor ini sudah dibuktikan tangguh, baik sebagai sakelar otomatis maupun sebagai penguat. hasil dari pengolahan pulsa yang dikeluarkan melalui trafo pulsa yang nantinya akan menjadi pulsa trigger . penggunaan trafo pulsa pada rangkaian ini juga berfungsi sebagai pengisolasi antara rangkaian elektronika dengan rangkaian elektronika daya sehingga ketika terjadi arus balik dari tegangan ac yang berlebih maka trafo pulsa saja yang akan rusak terlebih thyristor yang pada kaki trigger dengan besar arus -trigger mosfet dapat dilakukan dengan memberikan tegangan dengan besar tertentu, terlihat pada gambar 5. mosfet yang digunakan pada rangkaian ini adalah bertipe irf634. penggunaan mosfet tipe irf634 ini dilatarbelakangi karena tegangan masukan yang digunakan adalah sebesar 220 vac dan tegangan (vds) yang diberikan kepada mosfer irf634 ini maksimal 250 volt. tegangan trigger mosfet tipe irf634 ini adalah ±20 volt. karena mikrokontroler hanya mampu memberikan tegangan keluaran sebesar ± 5 volt maka dari itu pada rangkaian ini digunakanlah ic optocoupler 4n35 dengan keluarannya ditempatkan ic optocoupler tersebut. rancang bangun kendali sekuen untuk sambungan jala-jala listrik menggunakan cycloconverter (yuliadi erdani, aris eko setiyawan, maulana aria pratama) pp. 69-74 72 gambar 6. flowchart program minimum system. berbeda dengan perancangan rangkaian trigger penyulutan thyristor yang menggunakan kaki emitor sebagai keluaran tegangannya, ic optocoupler ltv-4n35 pada rangkaian ini berfungsi sebagai penguat tegangan maka dari itu keluaran dari ic optocoupler tersebut ditempatkan pada kaki kolektornya. tegangan yang dikeluarkan ic optocoupler tersebut selalu mengikuti besar tegangan vcc yang diberikan, apabila pada rangkaian diberikan tegangan (vcc) sebesar +10 volt maka keluarannya pun akan bernilai +10 volt namun konsekuensinya bentuk pulsa keluarannya akan berkebalikan dengan bentuk pulsa awalnya, misalnya jika bentuk pulsa awal bernilai “1” (high) maka bentuk pulsa keluarannya akan bernilai “0” (low). sama seperti penggunaan pada perancangan rangkaian trigger penyulutan thyristor, ic optocoupler ltv-4n35 selain berfungsi sebagai penguat tegangan pada rangkaian yang dibuat, ic inipun berfungsi sebagai isolator antara rangkaian mikrokontroler dengan rangkaian elektronika daya. iii. hasil & a�alisis pe�elitia� pada pengujian rangkaian cycloconverter ini besarnya tegangan pada pembangkit baru dan pln berada pada besaran nilai yang sama. frekuensi 50hz dijadikan referensi frekuensi untuk pembangkit pln dan frekuensi 10hz sampai 90hz adalah frekuensi untuk pembangkit baru. dengan inisialisasi kondisi seperti itu, dilakukan penaikan frekuensi dari 10hz 40hz menjadi 50hz dan penurunan frekuensi dari 60hz 90hz menjadi 50hz. untuk mengetahui kondisi awal dari nilai tegangan keluaran yang dihasilkan oleh cycloconverter maka fungsi dari thyristor digantikan oleh dioda. hasilnya dapat dilihat pada gambar 7 sampai dengan gambar 10. gambar 7. gelombang penaikan frekuensi dari 10hz menjadi 50hz. gambar 8. gelombang penaikan frekuensi dari 20hz menjadi 50hz. journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 73 gambar 9. gelombang penurunan frekuensi dari 60hz menjadi 50hz. gambar 10. gelombang penurunan frekuensi dari 90hz menjadi 50hz. pada rangkaian cycloconverter gelombang masukannya adalah 50 hz dan akan diubah menjadi 60 hz berdasakan nilai referensi frekuensi yang didapatkan dari pembangkit lama yang telah diolah oleh rangkaian pengaktifan mosfet dan nilai vrms keluarannya dapat diubah berdasarkan nilai referensi penyulutan tyhristor. hasilnya dapat dilihat gambar 11. gambar 11. gelombang keluaran cycloconverter (merah) terhadap gelombang keluaran pembangkit lama (biru). dari data tersebut di atas dapat dilihat perubahan frekuensi yang terjadi. dengan cara mengatur waktu pengaktifan mosfet, frekuensi gelombang bisa berubah dari 50hz menjadi 60hz dan sebagainya. waktu pengaktifan mosfet diatur oleh sensor frekuensi (zero crossing detector) apabila sensor frekuensi mendeteksi bahwa frekuensi pada gelombang adalah 60hz maka waktu yang dibutuhkan dalam membuat frekuensi 60hz adalah: f = 60hz => t = 1/f = 1/60 s = 16,67 ms waktu yang dibutuhkan untuk membuat satu gelombang baru adalah 16,67 ms. pada rangkaian digunakan dua buah mosfet yang aktif secara bergantian, maka untuk satu buah mosfet waktu pengaktifannya sebesar 8,335 ms. selain itu dengan menggunakan bantuan sensor frekuensi dapat diketahui pula bahwa sudut fasa juga dapat disinkronkan. dari hasil percobaan dapat dilihat bahwa terjadi penurunan tegangan rata-rata pada gelombang keluaran. terdapat dua penyebab penurunan nilai tegangan tersebut yaitu: rugi-rugi daya penyakelaran akibat penggunaan mosfet dan rumus keluaran dari gelombang penyearah dioda adalah: vout = 0,9 vin sehingga nilai tegangan rata-rata keluaran selalu lebih rendah dari nilai tegangan rata-rata masukannya. apabila fungsi dari dioda digantikan oleh thyristor maka nilai tegangan rata-rata gelombang keluaran akan cenderung lebih berkurang lagi sehingga untuk percobaan ini rangkaian cycloconverter tidak menggunakan thyristor tapi menggunakan dioda. gambar 12. pengaturan sudut penyulutan thyristor. proses sinkronisasi dapat dilakukan dengan tiga proses sekuen yaitu frekuensi dari pembangkit listrik baru sama dengan frekuensi pembangkit lama, tegangan dari pembangkit listrik baru sama dengan tegangan pembangkit rancang bangun kendali sekuen untuk sambungan jala-jala listrik menggunakan cycloconverter (yuliadi erdani, aris eko setiyawan, maulana aria pratama) pp. 69-74 74 lama, dan sudut fasa dari pembangkit listrik baru sama dengan pembangkit lama sehingga sefasa. ketika semua proses sekuen sudah terpenuhi maka koneksi antara pembangkit listrik lama dan pembangkit baru dapat dilakukan. diagram untuk proses koneksi dapat dilihat pada gamabar 12. hasil dari koneksi antara pembangkit dapat dilihat pada gambar 13. gambar 13. gelombang keluaran hasil koneksi antar pembangkit. dari gambar 13 dapat dilihat gelombang yang dihasilkan tidak membentuk gelombang sinus sempurna, karena gelombang tersebut telah mengalami penggabungan antara gelombang yang dihasilkan oleh cycloconverter dengan gelombang dari pembangkit lama. dapat dilihat pulsa frekuensi yang dihasilkan memiliki frekuensi yang sama dengan frekuensi pembangkit lama. iv. kesimpula� da� sara� rangkaian cycloconverter hasil modifikasi dapat menurunkan dan menaikan suatu frekuensi tertentu pada jaringan listrik menjadi frekuensi yang ingin dicapai dan menjadikan urutan fasa yang tidak sefasa menjadi sefasa dengan menggunakan bantuan sensor frekuensi (zero crossing detector) yang hasil dari pembacaan sensor tersebut menjadi titik acuan pengaktifan mosfet. rangkaian cycloconverter yang dibuat pada tegangan pembangkit yang sama tidak mengakibatkan terjadinya kenaikan tegangan melainkan terjadinya kekurangan besar tegangan, hal ini disebabkan karena pada rangkaian cycloconverter ini tidak menggunakan thyristor tetapi dioda. dengan proses kendali sekuen pada cycloconverter maka sinkronisasi dapat dilakukan, sehingga memungkinkan untuk menghubungkan pembangkit listrik ke jala-jala listrik. ucapa� terimakasih ucapan terimakasih disampaikan kepada sdr sodipta dan sdr yudi, alumni ae polman bandung angkatan tahun 2007 yang telah membantu kelancaran kegiatan penelitian ini, serta kepada proyek i-mhere melalui program research grant atas biaya yang diberikan untuk kegiatan penelitian ini. daftar pustaka [1] willis, h. l., “power distribution planning reference book”, marcel dekker, inc., 2nd ed., 2004. [2] short, t. a., “electric power distribution handbook,” crc press, 2004. [3] lander, cyril w., “power electronics” (3rd ed.), london: mcgraw-hill, 1993. isbn 0-07-707714-8. [4] thomas p. hughes, “networks of power: electrification in western society” 18801930, the johns hopkins university press, baltimore, 1983. isbn 0-8018-2873-2. [5] grigsby, l. l., et al., “the electric power engineering handbook”, usa: crc press, 2001. isbn 0-8493-8578-4. [6] dorf, richard c., the electrical engineering handbook, boca raton: crc press, 1993. isbn 0-8493-0185-8 [7] sistem pengendali elektronika daya [online]. available: http://www.scribd.com/doc/31754304/sist em-pengendali-elektronika-daya. diakses 4/12/2010. [8] kadek fendy sutrisna, (november 2008) cycloconverter : ac-ac konverter penurun frekuensi [online]. available: http://konversi.wordpress.com/2008/11/20/ cyclo-converter-ac-ac-konverter-penurunfrekuensi/, diakses 4/12/2010. [9] anoop mathew, [online]. available: http://www.anoopmathew.110mb.com/file s/ diakses 4/12/2010. mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.45-50 cfd and wind tunnel analysis for mounted-wind turbine in a tall building for power generation dany perwita sari a, *, kang-pyo cho b a research center for biomaterials, indonesian institute of sciences (lipi) cibinong science center bogor, jl. raya bogor km. 46, cibinong bogor 16911, indonesia b ckp wind solutions 992-73 dongjisan-ri, cheongha-myeon, gimje si, jeollabuk-do 576-893, korea received 08 january 2014; received in revised form 17 february 2014; accepted 19 february 2014 published online 23 july 2014 abstract a mounted wind turbine on the top of a tall building may provide high wind power in regions of high wind speed and low turbulence. the objective of this study is to evaluate wind speed on roof top models to optimize the wind turbine performance for power generation. comparative analyses from three different roof top models were conducted. computational fluid dynamics (cfd) simulation and wind tunnel testing were performed to evaluate the performance of wind turbine. wind speed on the building model with a geometric scale of 1:150 was measured in cfd simulation then it was validated in wind tunnel test. results presented in this paper suggest that an increase of wind speed could be achieved with ¼ circular shapes around the rooftop which can provide additional wind speed of 55.24%, respectively. keywords: wind speed, roof shape, cfd, wind tunnel, tall building. i. introduction in order to cope with global climate changes, it is urgently necessary to further develop new power energy system in which distributed energy is produced based on renewable energy source. indonesia government created legislatively binding target to reduce fossil fuel consumption by 26% by the year 2020 [1] with the vision of energy mixes originated from four main sources: oil (30%), coal (22%), gas (23%) and new renewable energy (25%) [2]. hence, tall building may use insulation and low energy devices to reduce energy and electricity consumption. nowadays architects and designers are starting to seek out an innovative tall building design. they are important players behind the commercial greening movement [3]. in fact, green building is considered one of the most cost-efficient ways of reducing greenhouse gas emissions [4]. mounted wind turbine on the top of a tall building is one of green buildings which on the rise. however, installations of a building integrated wind turbines (biwt) are still limited because of low mean wind speeds, high levels of turbulence and relatively high aerodynamic noise levels generated by the turbine [5]. abohela et al. [6] demonstrated that roof shapes could maximize energy harvesting from acceleration of the wind above the building. wind turbine power of a wind generator [7] can be expressed as follows: 𝑃𝑡𝑢𝑟𝑏𝑖𝑛𝑒 = 1 2 𝜌𝐶𝑝𝐴𝑉 3 (1) where 𝑃𝑡𝑢𝑟𝑏𝑖𝑛𝑒 is the wind turbine power, 𝜌 is the air density (kg/m 3 ), 𝐶𝑝 is the coefficient of performance, a is the swept area of the blades (m2), and v is free wind speed (m/s). from equation (1), it is showed that the power of the wind increases with the cube of the wind speed. it is clear that wind speed has an important part to maximize the power generation. wind turbine should be located at relatively windy site [8] and best roof shape. a few simulations using computational fluid dynamics (cfd) has been undertaken to study wind flow close to building’s roof for applications of roof mounted wind turbine [9]. on the other hand, a wind tunnel can be used to conduct wind turbine performance test [10]. * corresponding author. phone: +62-21-87914511 e-mail: dany.perwitasari@gmail.com http://dx.doi.org/10.14203/j.mev.2014.v5.45-50 d. p. sari and k. p. cho / mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 46 to maximize the wind turbine performance, three different roof shapes covering a tall building were simulated using cfd. in this study wind tunnel tests were carried out to validate the wind speed distribution and to determine turbulence flow. this model was tested in seoul, south korea. it rises about 64m from the ground. each model was simulated and tested with scale of 1:150. the objective of this study is to find the best design of rooftop on a tall building which can maximize wind turbine performance. ii. modelled parameters a mounted-wind turbine in a tall building is usually located in urban areas. this case study took place at seoul, the capital city of south korea. from the korean building code (kbc) 2009 [11], seoul is classified as terrain b which means urban and suburban areas with closely spaced residential or other buildings with height of 3.5m or so or scattered medium-rise buildings. a unique characteristic of wind is the variation of speed with height. the movement of the wind is controlled by the deviating force due to the earth’s rotation and the effects of friction of the surface of earth [12]. the wind velocity profile at certain area in atmospheric boundary layer could calculate using power law formula [12]. the urban terrain type specifies a mean wind speed profile with a power law exponent of 𝛼 = 0.22, exposure constant of zb = 15 m and nominal height of the atmospheric boundary layer of zg = 400 m. for specifying the optimum roof shape, the cfd commercial code fluent 6.2.16 was used to simulate wind flow and to calculate wind speed above three different roof shapes above rectangular building shape whose edge height is 64m (high rise building ratio depth : width : height = 1:1:4). wind turbine mounted building models are single tall building which were adopted and redesigned from mounted-wind turbine which currently exist (fig. 1). this building tower was designed to increase wind speed to maximize wind turbine power. using the wind turbine mounted building model in figure 1, experimental results are shown as velocity coefficient. it is obtained from the velocity in a certain point (at horizontal coordinate x) divided by velocity approach from boundary layer in terrain b. 𝐶𝑣 = 𝑉(𝑥) 𝑉𝛼 (2) wind turbine locations on building a, building b and building c are in the top of the building in the height range between 50m to 70m from the ground. the average wind velocity is 10m/s so that the wind velocity approach 𝑉𝛼 for each model is normalized to 10m/s. iii. cfd simulation first of all, each building is analyzed using cfd. cfd is used for simulating wind flow between twin towers and to develop the models to find the best aerodynamic shape and the point for wind turbine to get maximum wind velocity. building a, building b and building c are drawn using gambit 2.3. (scale 1:150). this scale is used for similarity in wind tunnel test to validate the cfd analysis result. each model uses boundary layer in terrain b with viscous kepsilon and all of the models were successfully iterated. the k-𝜀 turbulence model solves the flow based on the assumption that the rate of production and dissipation of turbulent flows are near-balance in energy transfer. the k-𝜀 model is one of the most common turbulence models [13]. figure 1. modelled roof shapes, from left to right: building a, building b, building c d. p. sari and k. p. cho / mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 47 figure 2 shows simulation results using cdf. the left hand side figure indicates vertical position (y), the right hand side figure demonstrates wind speed contour and horizontal position (x) from top view, and the middle figure plots velocity coefficient. in the middle figure, horizontal axis denotes horizontal position (x), vertical axis indicates velocity coefficient and each curve has certain vertical position (y) as its parameter. the wind velocity in building a increases in the center between the rounded towers. wind velocity coefficient increases to 1.4 (fig. 2(a)) or 40% more than wind velocity approach. figure 2(a) shows the best horizontal position for turbine, with height 2m up to 5m above the roof between the rounded towers. building b and building c are analyzed using the same method as building a. as to building b and building c, wind velocity was calculated at vertical location from 1m up to 5m above the roof surface (fig. 2(b)(c)). figure 2(d) compares velocity coefficient among building a, building b and building c. it can be seen that building b has the highest wind velocity coefficient in the value of 1.49. iv. wind tunnel experiment cfd simulations result has shown that maximum wind speed could be reached in building b and building c. hence, only building b and building c was tested using wind tunnel. wind tunnel experiment is use to validate the cfd analysis result. wind tunnel experiment was held in ckp wind solutions, gimje, south korea. detail of the wind tunnel size and component is shown in figure 3. wind tunnel test is also possible to calculate turbulence intensity which cannot be detected in cfd. the results are more accurate than cfd analysis and include the information for structural engineer. turbulence intensity is important to detect the turbulent flow around the wind turbine. this information is important to prevent the blade flicker and the user’s safety. figure 2. location of measurement point, wind speed coefficient result and wind speed contour: (a) building a, (b) building b, (c) building c, (d) wind velocity coefficient comparison between building a, building b and building c. the highest wind velocity coefficient is in building b d. p. sari and k. p. cho / mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 48 wind tunnel experiment also uses roughness block for terrain b to create boundary layer as the same as in the cfd analysis (fig. 3). wind velocities in wind tunnel experiment are calculated using cobra probes and pitot tube. figure 4 shows measurement set up and experimental result. wind velocity increases in the center of rounded towers along horizontal direction (x axis). in building b, the highest wind velocity is at point 3 in vertical direction between rounded towers. this point corresponds to the height of 3m above the roof surface. the maximum wind velocity coefficient is 1.33 or increase of 30% from approach wind velocity. in building c the maximum velocity coefficient increases 43% from wind velocity approach after passing rounded tower. wind velocity is higher and more stable compared to that in building b. the highest wind velocity is located in point 2 and 3. maximum wind coefficient is 1.43. turbulence intensity is shown in table 1. in building b it increases at point 1 and 2, and figure 3. (a) wind tunnel at ckp wind solutions, south korea; (b) roughness block of terrain b in wind tunnel experiment table 1. turbulence intensity data from cobra probes in building b and building c building b building c position i a overall (%) iu b (%) iv c (%) iw d (%) position i a overall (%) iu a (%) iv b (%) iw c (%) v inlet 12,488 14,005 11,920 11,256 v inlet 12,773 14,574 12,394 11,161 point 01 21,872 21,872 21,683 21,967 point 01 25,759 23,010 30,593 22,631 point 02 23,673 24,811 24,052 22,157 point 02 19,218 23,389 17,702 15,616 point 03 12,299 15,427 11,446 9,360 point 03 9,266 11,730 9,019 6,251 point 04 10,024 13,342 8,555 7,086 point 04 9,550 12,488 8,640 6,754 point 05 9,550 12,394 8,697 6,896 point 05 9,218 11,730 8,555 6,650 a i is the value of turbulence intensity; b iu is the value of turbulence intensity from the longitudinal (horizontal) direction; c iv is the value of turbulence intensity from the vertical direction; d iw is the value of turbulence intensity from the lateral directions. d. p. sari and k. p. cho / mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 49 being normal at point 3. in building c it increases at point 1 and 2 and normal at point 3. v. validation figure 5 shows validation result between cfd analysis result and wind tunnel testing result. figure 5 (a) shows the result of building b while figure 5 (b) shows the result of building c. wind velocity increases in the center of rounded towers. as to building b, wind velocity increases 30% in wind tunnel experiment and 50% in cfd analysis. one reason of wind velocity decrease in wind tunnel test is because of the roughness surface of the rounded tower in the model. even though wind tunnel result has been proven to be representative of real world situation, it requires a correct model which accounts for the features of the atmosphere and exact scaling as well as model shape. building c is a modified twin tower from building b. wind velocity increases at the center of rounded towers. the highest wind velocity is figure 5. validation result from cfd simulation and wind tunnel test: (a) building b and (b) building c figure 4. cobra probes test in wind tunnel windward surfaces in the middle of rounded towers and wind velocity coefficient results: (a) building b, (b) building c d. p. sari and k. p. cho / mechatronics, electrical power, and vehicular technology 05 (2014) 45-50 50 in point 3 between rounded towers. in wind tunnel experiment, wind velocity increase 32 to 42% from wind velocity approach. wind velocity increase 42% in cfd. blockage effect in wind tunnel test because of swept area (a) is covered by cobra probes (blockage effect in building c is 7.49%). normally, blockage effect is not more than 5% [12]. this model shape is less performance than building b. on the other hand, building c’s turbulence intensity is more stable than building b, which is safer and less vibration. vi. conclusions based on cfd simulation and wind tunnel test result on three roof shapes, this study evaluated wind speed, wind flow and turbulence intensity on the roof top of tall building. the most important results of this study can be summarized as follows: 1. wind speed plays an important role to maximize performance of mounted-wind turbine in a tall building. modifying the building roof top could increase wind speed ranging from 27 to 55%. 2. cfd simulation and wind tunnel test on roof top designs show that wind speed increases at the center of rounded towers. 3. the cfd simulation results show that the minimum performance is in building a and the maximum performance is in building b. 4. the wind tunnel test results in building b and building c indicate a good agreement with the cfd simulation results. 5. the wind tunnel test data also shows that building c is the safer and less vibration building design, based on turbulence intensity result. acknowledgement we would like to thank the indonesian institute of sciences (lipi), wonkwang university and ckp wind solutions for allowing this study to be undertaken and to the staff at each institute and university for taking the time to participate in this study. references [1] presidential regulation (peraturan presiden) no.6/2011, “rencana aksi nasional penurunan emisi gas rumah kaca,” in national standarization agency of indonesia, 2011. [2] directorate general of new renewable energy and energy conservation, “renewable energy development,“ in ministry of energy and mineral resources, 2012. [3] s. deneen and b. howard, “buildings that breathe: green construction is coming of age,” e magazine january/february, 2007. [4] j. ola, “the spatial diffusion of green building technologies: the case of leadership in energy and environmental design (leed) in the united states,“ international journal of technologies management and sustainable development, vol.10, no.3, 2011, pp.251-266. [5] l. ledo, et al., “roof mounting site analysis for micro-wind turbines,“ renewable energy, vol.36, 2011, pp.13791391. [6] i. abohela, et al., “effect of roof shape, wind direction, building height and urban configuration on the energy yield and positioning of roof mounted wind turbine,“ renewable energy, vol.50, 2013, pp.1106-1118. [7] s. sinisa, et al., “urban wind energy,“ earthscan, uk and usa, 2009. [8] q.s. li, et al., “implementing wind turbines in a tall building for power generation: a study of wind loads and wind speed amplifications,“ journal of wind engineering and industrial aerodynamics, vol.116, 2013, 70-82. [9] w. sara louise, “building mounted wind turbines and their sustainability for the urban scale-a review of methods of estimating urban wind resource,“ energy and buildings, vol.43, 2011, pp.1852-1862. [10] pudji irasari, “experiment and analysis of car alternator for wind turbine application,” journal of mechatronics, electrical power and vehicular technology, vol.02, pp.1-10, 2011. doi: 10.14203/j.mev.2011.v2.1-10. [11] korean building code-stuctural, 2009. [12] n.m. guirguis, et al., “study of wind effects on different buildings of pitched roofs“, desalination, vol.209, 2007, pp.190-198. [13] l. henry, “wind engineering: a handbook for structural engineers,” prentice hall, ebook, 2008. microsoft word vol04_no1 add pages _rev_aam_ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv journal of mechatronics, electrical power, and vehicular technology international peer reviewers prof.ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof.dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering,universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2,yogyakarta 55281, indonesia a.setiawan@ugm.ac.id pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, blg 20, 2ndfl, bandung 40135, indonesia pudji.irasari@lipi.go.id dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 v dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr.eng. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135 estiko.rijanto@ lipi.go.id dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia moch019@lipi.go.id dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vi publication ethics and malpractice statement mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics lipi). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vii 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 viii author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with coma and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board j. mechatron. electr. power veh. technol 06 (2015) 1–8 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.1-8 development of a microcontroller-based wireless accelerometer for kinematic analysis maria clarissa alvarez carasco a, *, jan pierre potato pizarro a , giovanni alarkon tapang a a versatile instrumentation system for science education and research national institute of physics, university of the philippines diliman, quezon city, philippines received 14 october 2014; received in revised form 14 february 2015; accepted 16 february 2015 published online 30 july 2015 abstract wireless sensor networks (wsns) allow real-time measurement and monitoring with less complexity and more efficient in terms of obtaining data when the subject is in motion. it eliminates the limitations introduced by wired connections between the sensors and the central processing unit. although wireless technology is widely used around the world, not much has been applied for education. through versatile instrumentation system for science education and research (visser), a project which aims to develop modern science laboratory equipment for high school education and research in the philippines, a low cost wsn using nrf24l01+ rf transceiver that is developed to observe and analyze the kinematics of a moving object is discussed in this paper. data acquisition and transmission is realized with the use of a low power and low cost microcontroller attiny85 that obtains data from the adxl345 three-axis accelerometer. an attiny85 also controls the receiving module with a uart connection to the computer. data gathered are then processed in an open-source programming language to determine properties of an object’s motion such as pitch and roll (tilt), acceleration and displacement. this paper discusses the application of the developed wsn for the kinematics analysis of a toy car moving on flat and inclined surfaces along the three axes. the developed system can be used in various motion detection and other kinematics applications, as well as physics laboratory activities for educational purposes. keywords: wireless sensor network; accelerometer; kinematics; nrf24l01+. i. introduction with the world pushing forward towards the internet of things (iot), which improves the transfer of information without much human interaction, almost everything is going wireless. wireless technology is already being used in the industry, home automation and monitoring applications. wireless sensor networks (wsns) are one of the key components in the iot, which serves as ground for information about physical quantities of the world that can be accessed remotely by any computing system. wsn integrates sensing, communication and computation capabilities into a single, compact device. this addresses the challenges of detecting significant quantities, monitoring and collecting data, and analyzing the information gathered [1, 2]. wireless sensor networks eliminate the complexity in connections for wired systems and allow free movement for bodies with on-board sensors. numerous designs for wireless sensor networks have already been published. wsns have been developed for health care that can monitor physiological conditions, motion and activity such as accidental falls [3, 4], and behavioral patterns [5]. aside from medical and health care; various prototypes have been made for environmental monitoring like temperature [6], soil moisture and temperature in croplands [7], and a cluster of environmental factors can be analyzed from wsn data like solar radiations, co2 flux, wind, water contamination, etc [8]. papers on wsns for industrial monitoring applications have also been published like fault analysis in the electrical field [9, 10]. still, there have only been few efforts in incorporating such technology in the field of science education. in the philippines, a 2012 official report stated that only 2,809 public high schools out of 7,470 had science laboratories [11], moreover some of the laboratory devices of those who have are outdated or incomplete. although there are science laboratory equipment * corresponding author.phone: +632 9209749 e-mail: clarissa.carasco@gmail.com m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 2 available in the market, they are expensive and public high schools cannot afford them. to improve the quality of science education and the state of science laboratories in high schools, versatile instrumentation system for science education and research (visser) develops laboratory devices (e.g. sensors) that incorporate modern technology such as wireless capabilities and multiple interfacing of datagathering devices. the developed devices must be robust, sophisticated and low cost so that public high schools and institutes can afford those [12]. in line with the goals of visser, a design of a wireless sensor network that is applied to kinematic analysis, such as acceleration of an object moving on flat and inclined surfaces, is developed. the main goal is to implement the wireless sensor network design with low cost and low power components. ii. methodology a. system architecture figure 1 shows the overall design of the wireless sensor network. the accelerometer is connected to the microcontroller unit (mcu) through serial peripheral interface (spi) and a radio frequency (rf) transceiver module is used to transmit the data to the central receiving module. the rf transceiver is connected to the microcontroller via spi as well. for the receiving side, a similar architecture is used. a microcontroller accesses the transceiver through spi and sends the data to a pc application via uart. sensor adxl345 microcontroller attiny85 rf transceiver nrf24l01+ (a) rf transceiver nrf24l01+ microcontroller attiny85 pcpc (b) figure 1. system overview of: (a) transmitter module; (b) receiver module m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 3 b. microcontroller the system uses attiny85, a low power and low cost cmos8-bit microcontroller that is based on the avr advanced risc structure, as its main processor [13]. it is an 8-pin microcontroller that can be powered with a voltage supply of 1.8 v – 5.5 v and draws about 300 μa when in active mode and 0.1 μa when in power-down mode, both at 1.8 input voltage. the attiny85 has 8 kbytes of program memory that is in-system programmable via spi ports. although the program memory of the microcontroller is smaller than many other chips, 8 kbytes is enough for our application. also, the microcontroller has 6 programmable i/o lines but out of the 6 i/o lines of the attiny85, only five are used actively as i/o pins with the default setting of the fuses. these i/o lines can also be configured for i2c or spi interface using universal serial interface (usi) to communicate with one or multiple slave devices such as sensors, (e.g. accelerometer), real-time clocks, sd card modules, etc. the attiny85 is chosen because of its cost which is around $1 and can be easily bought in electronics stores and online shops. c. radio frequency transceiver the nrf24l01+ (see figure 2) is an rf transceiver that operates at the 2.4 ghz industrial, scientific and medical (ism) radio band and uses the enhanced shockburst™ protocol engine for ultra-low power wireless applications [14]. some of the key features of enhanced shockburst™ are:  1 to 32 bytes dynamic payload length  automatic packet handling  auto packet transaction handling  auto acknowledgement  auto retransmission  6 data pipe multiceiver™ for 1:6 star networks. it is also a low power device consuming only 11.3 ma when in transmitting mode and 12.3 ma at 2 mbps receiving mode. the nrf24l01+ transceiver can be powered with 1.9 v – 3.6 v. in standby mode, the nrf24l01+ uses 22 μa and is disabled with 900 na current consumption when in power-down mode. the air data rate, output power and frequency channel settings are userprogrammable via spi. it can be used with speeds of 1mbps or 2mbps. this rf transceiver utilizes a minimum of 7 pins, 4 i/o pins for spi interfacing, 1 pin as enable and 2 pins for the supply. this means that all the available i/o ports of the attiny85 will be used by the rf transceiver alone. the nrf24l01+ transceiver is available for less than $1 which makes it suitable for the low cost wsn design. d. sensor and transmitter module design in order to gather data regarding the motion of the subject, adxl345 accelerometer is used. the adxl345 is a three-axis accelerometer that measures static acceleration of gravity, as well as figure 2. nrf24l01+ transceiver circuit schematic m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 4 dynamic acceleration resulting from motion. it has a supply range of 2 v – 3.6 v and consumes 23 μa in measuring mode and 0.1 μa in standby mode with 2.5 v input. it has a user-selectable measurement range of ±2 g, ±4 g, ±8 g, and ±16 g and output resolution of up to 13-bit at ±16 g [15]. the accelerometer can be interfaced to the microcontroller via spi (3-wire and 4-wire) and i2c. for this application, the adxl345 accelerometer is accessed by the microcontroller via 4-wire spi and selects the full range ±16 g resolution. since all the pins for one microcontroller is being used by the rf transceiver alone, a second attiny85 is utilized. figure 3 shows the block diagram for the solution to lack of pins in the microcontroller. the first microcontroller (mcu1) accesses the accelerometer via spi and passes the data gathered to another microcontroller via rx/tx. the accelerometer uses the 4 i/o pins of the microcontroller leaving one free i/o pin that is used as tx line to the second microcontroller. the second microcontroller will then retrieve the data serially then pass it on to the rf transceiver for final relaying of data to the receiving module. the fuse of the second microcontroller (mcu2) is altered from the default settings in order to use reset pin as “weak” i/o port to free up one i/o pin for serial communications. the rstdisbl is programmed to use pin 1 as an i/o port. figure 4 shows the flow chart of the hardware program for the two microcontrollers (mcu1 and mcu2). the two programs in each mcus run simultaneously once the transmitter module is powered. rx tx adxl345 accelerometer sck mosi miso cs attiny85 microcontroller attiny85 microcontroller sck mosi miso cs nrf24l01+ rf transceiver figure 3. block diagram of the transmitter module figure 4. flow chart for the transmitter module hardware program m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 5 e. receiver module design the receiver module uses the same microcontroller and transceiver for data reception. shown in figure 5 is the block diagram of the receiver module. after receiving the data from the transmitter module, the microcontroller passes it now to the pc for data storage and analysis via rx/tx to usb connection. f. data handling and storage the data sent from the rx/tx lines of the pc are saved in a file for later analysis. python, a general-purpose, high-level (hll) programming language, is used to read the data from the serial line, and store the time-stamped data locally in the computer. iii. testing and results figure 6 shows the prototype developed for the transmitter module. the prototype is modular and compact. it is powered by a cr2032 3-volts coin battery. the prototype is tested by placing the transmitter module onboard a toy car and then measuring the triaxial acceleration of the toy car when pulled/pushed and when let down on an inclined plane. figure 7 shows the triaxial acceleration when pulling then pushing the toy car with the attached sensor along the y-axis. the acceleration along the z axis does not change since the subject does not experience acceleration due to motion and is affected only by the earth’s pull. the negative values denote that the subject is moving along the positive direction of the y-axis. on the other hand, the negative values denote that the subject is moving in the opposite side of the y-axis. although the expectation is that no acceleration is present for the x-axis, the plot shows that there are readings at some points. this is due to the movement of the axle of the toy car’s wheels which is not fixed. also, the ideal straight line path of the toy car is not possible rx tx nrf24l01+ rf transceiver sck mosi miso cs attiny85 microcontroller computer figure 5. block diagram of the receiver module figure 6. prototype of the transmitter module m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 6 with this type of front wheels. hence, the readings in x-axis. also, in order to test if the transmitter is working along the z-axis, the toy car with the attached sensor is made to go down an inclined plane. figure 8 shows the acceleration when in an inclined plane with 21.3 degrees. figure 9 shows the result for an inclination of 36.06 degrees. it is shown in the figures 8 and 9 that the value of acceleration at z-axis is changing when the subject is on an inclined plane. also the value of the acceleration at y-axis varies since the forward movement of the subject is not only towards z-axis but also aligned with y-axis. while the accelerations at x-axis is low since there is no significant movement along this axis. the graphs above are only preliminary tests which show that the wireless accelerometer is working and behaves as expected. the device can now be calibrated as a next step. figure 7. acceleration vs time for pushing/pulling of toy car figure 8. acceleration vs time for inclined plane with ө = 21.38 degrees m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 7 iv. conclusion the wireless sensor network developed is capable of determining the kinematics of an object moving on a flat and inclined surface along the three axes. also, other properties of an object’s motion such as pitch and roll, and free fall detection, can be obtained and analyzed from the stored raw data. the integration of wireless technology to kinematic analysis delivers a more efficient way of data gathering. such sensor network can be applied to physics laboratory experiments for educational purposes. this kind of technological advancement for science education would lead to the realization of the goal of visser. for further improvements, a user-interface which can set when to start and stop data gathering can be included in the system. acknowledgement this paper is a part of the versatile instrument system for science education and research (visser), a project funded by the department of science and technology (dost) and university of the philippines emerging interdisciplinary research (up eidr). references [1] r. roman, et al., “do wireless sensor networks need to be completely integrated into the internet?” future internet of people, things and services (iopts) ecosystems, brussels. 2nd, december. 2009. [2] f.l. lewis, “wireless sensor networks,” smart environments: technologies, protocols, and applications, new york, 2004. [3] y. lee, et al., “implementation pf accelerometer sensor module and fall detection monitoring system based on wireless sensor network,” proceedings of the 29 th annual international conference of the ieee embs, cite internationale, lyon, france, august. 2007. [4] h. chan, et al., “wireless body area network for physical-activity classification and fall detection,” 5th international summer school and symposium on medical devices and biosensors, june. 2008. [5] z. zhang and x. hu, “zigbee based wireless sensor networks and their use in medical and health care domain,” seventh international conference on sensing technology, 2013. [6] y. zhu, et al., “design of wireless multipoint temperature transmission system based on nrf24l01,” international conference on business management and electronic information (bmei), 2011. [7] h. liu, et al., “a wireless sensor network for cropl and environmental monitoring,” international conference on networks, security, wireless communications and trusted computing, 2009. [8] r. mittal and m.p.s. bhatia, “wireless sensor networks for monitoring the environmental activities,” ieee 2010. figure 9. acceleration vs time for inclined plane with ө = 36.03 degrees m.c.a. carasco et al. / j. mechatron. electr. power veh. technol 06 (2015) 1–8 8 [9] l. hou and w. bergmann, “novel industrial wireless sensor networks for machine condition and fault diagnosis,” ieee transactions on instrumentation and measurement, vol. 61 no. 10, october 2012. [10] f. salvadori, et al., ”monitoring and diagnosis in industrial systems using wireless sensor networks,” ieee, 2007. [11] s. panela. (2012, sept. 17). do top phl schools' low world rankings reflect state of science ed in country? [online]. available: http://www.gmanetwork.com/news/story/27 4398/scitech/science/do-top-phl-schoolslow-world-rankings-reflect-state-of-scienceed-in-country [12] philippine-american academy of science and engineering. visser: versatile instrumentation system for science education and research. [online], 2011, available: http://www.paase.org/visser.html [13] atmel, “atmel 8-bit avr microcontroller with 2/4/8 k bytes in-system programmable flash,” attiny85 datasheet, 2013. [14] nordic semiconductor, “nrf24l01+ single chip 2.4 ghz transceiver preliminary product specification v1.0,” nrf24l01+ datasheet, march 2008. [15] analog devices, “3-axis, ±2 g/±4 g/±8 g/±16 g digital accelerometer,” adxl345 data sheet, 2013. quality evaluation of the modified diesel-electric train (krde) mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.51-56 quality evaluation of the modified diesel-electric train (krde) taufik hidayat*, hilman syaeful alam technical implementation unit for instrumentation development lipi jl. sangkuriangkomplek lipi gedung 30, bandung 40135, indonesia received 10 december 2012; received in revised form 18 march 2013; accepted 18 march 2013 published online 30 july 2013 abstract quality of the diesel-electric train (krde) modified from the electric train (a and b types) which were used in three operating regions in the indonesian railway company has been evaluated by analyzing the cause of the krde damages in terms of some aspects including: design, components quality, maintenance (method, finance, human resources), environment and way of operation. based on the evaluation, it was found that the modification of the both types of krde provided a very low reliability and availability due to design and technical problems, as well as unoptimal maintenance. in krde type a, damage occurs in the cabling system, compressor, radiator fan system, and the braking system. while in type b, damage occurs in the traction motors, static inverter, and radiator fan. it is predicted that their life span can not reach the design life of 25 years, and even they are expected to be grounded. many improvement is required to lengten their service life including: repair, modification, human resource competence, facilities, spare parts, maintenance and management. keywords: quality improvement, diesel-electric train, damage, maintenance, operation. i. introduction one of effective ground transportation modes in terms of speed, capacity and flexibility of transport is train [1]. transportation cars and other motor vehicles contribute highest energy consumption and emissions when compared to trains in the aspects of vehicle production, maintenance, operations, infrastructure and production materials [2]. in the poin of view of effectiveness and cost benefit, railroad is more profitable than conventional bus [3]. pt. kai is a leading provider of public transportation using railways in indonesia. to address the problems of urban commuter transport, it has been operating rail diesel electric trains (krde). in the operation area 2, 6, and 8 it also operates krde modified from two types of electric trains (krl). however, there are some problems that occur both technically and commercially, such as reduced reliability whether caused by technical aspects (design and manufacturing) as well maintenance (availability of spare parts, machinery, equipment, human resources and financing). these problems result in the cancellation of the scheduled departure, train delays and break downs. moreover, high operating cost and maintenance cost will probably lead the trains to be grounded. the study in this paper focuses on analyzing the causes of the krde damage in terms of design, components quality, maintenance (methods, financing, human resources), environment and way of operation. ii. materials and methods a rail diesel train (krd) has its own drive train whose power is provided by its diesel power source. a diesel electric train (krde) is one type of krd that uses electric power transmission (generator, electric power control and electric motor) [4, 5]. in 2005, modification of electric trains (krl) into diesel electric trains (krde) has been conducted. figure 1 (a) shows a modified version krde from krl type a, and (b) shows a push-pull krde modified from krl type b. the configuration difference between both types of krde can be seen in figure 2 [6, 7], while the captions are tec: car trailer with diesel generator sets and cab driver, m: motor * corresponding author. tel: +62-813-94297528 e-mail: taufiklipi@yahoo.co.id http://dx.doi.org/10.14203/j.mev.2013.v4.51-56 t. hidayat and h.s. alam / mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 52 car with inverters and traction motors, t: car trailer, and tc: car trailer with cab driver. table 1 shows the name and operational areas of the modified krde in three operation regions (daop) of pt. kai. to facilitate evaluation, the problems are classified into five categories, namely: (1) human resources (hr), (2) facilities and equipment, (3) method or procedure of maintenance including materials or spare parts, (4) maintenance execution, and (5) operational facilities including graph train journey (gapeka). common technical problems concerning maintenance which reflect real conditions that exist in the operation areas are obtained through interviews, field observations, and supporting data observations. iii. results and discussion the first aspect of krde quality improvement evaluation is human resources. based on the results of a survey conducted through questionnaires to 21 maintenance personnels spread across the area of krde operations, the following finding is obtained: training has been rarely done related to electronics technology which is applied to krde; ability of the technicians is still lacking in operation of electrical measuring devices such as avo-meter, oscilloscope and megger. the level of knowledge of krde technicians concerning basic electronics and power electronics maintenance is obtained by giving 10 basic questions. figure 3 shows graphically the level of their knowledge. yogyakarta’s operational area was the highest at 70%, and no one was able to answer all questions correctly even if only a basic question. the graph shows that the competency of krde technicians stills less. improvement is needed by providing continuing training. other problems associated with human resources are: inadequate number of maintenance personal; and rapid rotation of employees. the second aspects in the evaluation are the facilities and equipment. the facilities that exist in almost every area of operations, such as supporting building, workshops, track, pit gauge, servicing horizontal ladder, overhead cranes, lifting jacks, etc., are designed for locomotive maintenance, so that they are not suitable for krde maintenance. the length of gauge of servicing horizontal ladder is not enough (minimum requirement is 80 meters). there is less or no lifting jack to lift at once a set of krde. special equipment to repair krde is still incomplete (for example: software for communication and diagnostic of the traction converter for krde). the third aspects of evaluation are related to maintenance methods and procedures. in general, every region already has a clear organizational structure of running maintenance, and has been carrying out the scope of work in accordance figure 2. configuration difference between both types of krde figure 1. (a) modified version krde from krl type a (b) push-pull krde modivied from krl type b table 1. name and operational areas of krde no. operation regions (daop) name of krde 1 daop 8 surabaya krde arek surokerto 1 krde arek surokerto 2 2. daop 2 bandung krde baraya geulis krde rencang geulis 3. daop 6 yogyakarta krde prameks-1 krde prameks-2 krde prameks-3 t. hidayat and h.s. alam / mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 53 with its function. however, the method of maintenance is still based on time, while krde maintenance should be based on operating time (hours of operation) and mileage (kilometers). other problems are limitation of krde maintenance budget, lack of spare parts, lack of procurement mechanisms of special components so that the krde cannot be operated because it must wait for the materials or spare parts. the 4th aspect of evaluation is related to maintenance execution. general maintenance of krde has been done at two places, dipo and balai yasa in each daop. the maintenance carried out at the dipo is a monthly periodic of maintenance as follows: daily maintenance, 1month maintenance (p1), 3-month maintenance (p3), 6-month maintenance (p6) and 12-month maintenance (p12). the maintenance done at balai yasa includes 2nd annual maintenance (spa), 4-year maintenance (pa) and repair (pb). monthly periodic maintenance of krde facilities has been implemented at the dipo, but other maintenances at balai yasa which covers spa, pa, and pb, has not been implemented according to the requirements because of the following reasons: insufficient competence to perform maintenance and lack of supporting equipment. the 5th aspect is related to operational patterns of train journey (gapeka). this pattern is strongly influences to the effectiveness of the krde maintenance. due to short time available for maintenance, in fact krde maintenance is not possible to be conducted. krde performance can be seen from the aspect of availability and operational. there are several terms that describe krde conditions, namely: so, tso and res. so means ready for operation, tso means not ready for operation, and res indicates a condition in which the train can be operated but it was decided not to operate due to routine maintenance, inspection and minor repair. res is also associated to a condition in which the train is ready for operation (so) but the management decided not to be operated. in the daop 8 surabaya, there are 2 sets of krde arek surokerto, which started operating in october 2009 as commuter trains having route from surabaya to mojokerto. these krde are modification version of krl type b or krde push-pull, namely krde set 1 and krde set 2. the krde has been experiencing technical problems even though improvement and modification efforts have been made by the manufacturer. it can be seen from the percentage of so, which only reached an average of 51%, figure 5. tso causes of krde arek surokerto set-1 and set-2 figure 3. charts of basic electronics and power electronics knowledge level of krde technicians figure 4. operationilability of krde arek surokerto t. hidayat and h.s. alam / mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 54 see figure 4. the data processing is carried out in the period from 1 october 2009 until 27 november 2011 [8]. tso causes of krde arek surokerto can be seen in figure 5. it impaired and damage due to the traction motors dominated the causes of tso of krde set 1, while krde set 2 is dominated by the engine problems. damage to the traction motor (tm) is the most prominent case, because the damage occurred in all the units from the total of eight units of tm. figure 6 shows the traction motor of krde push-pull. the majority of the damage occurred on the pinion gear that connects the rotor to the shaft that is connected to the power distributor gearbox. this damage contributes significantly to the total damage resulting in tso. damage to the engine ranks second as a cause of krde tso. one cause of damage to the engine was leaking oil filter. the oil filter is easily hit by hard objects (rocks, etc.) because its position is too low and it is not equipped with a safety protection. the position of air combustion intake is under floor, so it is easy for dirt or dust to enter and clog the air filter. damage also occurred at the engine sensors, such as oil pressure sensor. it is difficult to obtain spare parts. in the daop 2 bandung, there is krde baraya geulis with a round-trip route from padalarang to cicalengka. maintenance and repairs of krde are periodically handled by locomotive dipo bandung. krde barayageulis has experienced journey of 65632 km or 2216.30 hours. its average performance since the beginning of operation until september 2011 is shown in figure 7 [9]. disruptions and damage are categorized into four categories, namely: pneumatic, diesel, electric, and mechanical. the amounts of damage per category during 2008 to 2011 are shown in figure 8 [9]. based on this data, it can be concluded that the damage to the pneumatic system (compressor, air ducts) and the electrical system is the dominant factors. besides baraya geulis, krde operated in daop 2 bandung is krde rencang geulis. krde rencang geulis has own mileage of 76,064 miles or 3141.45 hours with a round-trip route from padalarang to cibatu. the average performance of krde rencang geulis from the beginning of operation until september 2011 was the 65% so and 35% tso, as shown in figure 9 [9]. the number of disruption of krde rencang geulis per category can be seen in figure 10 [9]. major disruptions at krde rencang geulis are not much different from krde baraya geulis, which are dominated by the pneumatic system (compressor, air ducts), and electrical systems. in the daop 6 yogyakarta, there are krde prameks 1, 2 and 3 with a round trip route from solo to yogyakarta and solo to kutoarjo. krde maintenance is the responsibility of the locomotive dipo solo. figure 11 shows the performance of krde prameks-1, 2 and 3 from 2009 until 2011 [10]. figure 6. (a) traction motor (tm) which has been repaired, and (b) tm position that is still attached to the system figure 7. operations (so) of krde baraya geulis from 2008 to 2011 figure 8. total disruptions per-category of krde baraya geulis from 2008 to 2011 figure 9. operations (so) of krde rencang geulis from 2009 to 2011 t. hidayat and h.s. alam / mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 55 figure 12, figure 13 and figure 14 show technical factors cause disruption or tso beyond routine maintenance and inspection for each krde prameks 1, 2 and 3. while the code of disruption causes is described in table 2 [10]. based on the average percentage of so, krde prameks-1 has the so by 79% over the past three years, indicating that supply is still below from the target of 85% so. based on data disruption, there is a number of dominant damage, such as compressor system, braking system and control cables. there is a recurrent nature of the disorder, such as damage to the compressor, control wiring, and damage to the stairs or doors, resulting long enough of tso. there is a nonrecurring disruption that results in a long tso due to unavailable parts, such as traction motor damage. in krde prameks-2, the average percentage of so for three years, amounting to 89%, suggesting that the availability of krde prameks-2 meet the target (minimum 85%), while the disruption is dominated by the damage in the compressor system, engine, and control systems. there is a recurrent nature of the disorder, such as impaired compressors, control cables, and disruption of the stairs or doors that lead to long tso status. next on krde prameks 3, the average percentage of so for three years, which are 70%, figure 10. total disruptions per-category of krde rencang geulis from 2008 to 2011 figure 11. operations (so) of krde prameks 1, 2 and 3 from 2008 to 2009 figure 12. tso of kdre prameks 1 from the year 2009 to 2011 figure 13. tso of kdre prameks-2 from the year 2009 to 2011 figure 14. tso of kdre prameks-3 from the year 2009 to 2011 table 2. code of causing tso of krde prameks codes tso causes of krde prameks a compressor system. b braking system: wind pipe, air tank, valve, and air dryer. c doors, stairs, glass, lighting, and painting. d routine maintenance (km base, time base). e examination (outside routine, because visible symptoms of damage). f control system, wiring, coupler, 110 vdc supply voltage, battery. g alternator, main rectifier, vvvf, siv, tm. h engine, engine start system, fuel system. j cooling system engine (micromaster, cooler, etc.). l bogie, spring water, leveling valve. m wheels & bearings. t. hidayat and h.s. alam / mechatronics, electrical power, and vehicular technology 04 (2013) 51-56 56 indicating that the availability of krde prameks-3 has not met the target (minimum 85%). damage occurs predominantly in the control system, wiring, electrical compiler, engine cooling system (micromaster, cooler, etc.), and compressor systems. very long tso on the krde prameks-3 was caused by revamping cabling system that takes a very long time, and the delay is due to the procurement of spare parts of micromaster. iv. conclusions the krdes which were modified from krl type a and b had a very low reliability and availability due to the design and technical problems as well as un-optimal maintenance. disruption and damage that often occur on krde (modification from krl a) are the cabling system, compressor, radiator fan system, and the braking system, while krde push-pull (modification from krl b) are the traction motors, static inverter, and radiator fan.the krdes maintenance is not optimal because the facilities and support equipment have not been adequate. there is no specific maintenance budget for krde. the competency of human resources is still lacking and there are mistakes in maintenance management system and delays in maintenance. the life span of krde for both type a and b is predicted that it can not reach the design life of 25 years, and even they are expected to be grounded. many improvements are required to extend their service life including: repair, modification, human resource competence, facilities, spare parts, maintenance and management. references [1] j. armstrong and j. preston, "alternative railway futures: growth and/or specialisation?," journal of transport geography, vol. 19, pp. 1570-1579, 2011. [2] m. v. chester, et al., "comparison of lifecycle energy and emissions footprints of passenger transportation in metropolitan regions," atmospheric environment, vol. 44, pp. 1071-1079, 2010. [3] a. tirachini, et al., "restating modal investment priority with an improved model for public transport analysis," transportation research part e: logistics and transportation review, vol. 46, pp. 1148-1168, 2010. [4] undang-undang republik indonesia nomor 23 tahun 2007 tentang perkeretaapian, 2007. [5] peraturan pemerintah republik indonesia nomor 56 tahun 2009 tentang penyelenggaraan perkeretaapian, 2009. [6] p. t. inka, "manual maintenance and operation of diesel electric train (krde push pull)," p.t. inka 2009. [7] p. t. inka, "manual maintenance and operation of diesel electric train (krde)," p.t. inka 2009. [8] p. t. kai, "the disruption watch list of krde arek surokerto," daop 8 surabaya, p.t. kai 2011. [9] p. t. kai, "data summary and disorders of baraya geulis and rencang geulis," daop 2 bandung, p.t. kai 2011. [10] p. t. kai, "the damage, repair, and maintenance of krde," dipo locomotive solobalapan, daop 6 yogyakarta, p.t. kai 2011. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 73-78, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.73-78 kajian biogas sebagai sumber pembangkit tenaga listrik di pesantren saung balong al-barokah, majalengka, jawa barat study of biogas for power generation at pesantren saung balong al-barokah, majalengka, west java maulana arifin, aep saepudin, arifin santosa pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia maul004@lipi.go.id; hilal_zalfa@yahoo.com diterima: 18 oktober 2011; direvisi: 2 november 2011; disetujui: 25 november 2011; terbit online: 22 desember 2011. abstrak pemanfaatan biogas dari kotoran sapi sebagai alternatif bahan bakar pembangkit listrik dilakukan melalui proses anaerobik. pilot plant dengan produksi biogas sebesar 7 m3/hari telah terpasang di pesantren saung balong. biogas ini dimanfaatkan untuk keperluan sehari-hari seperti memasak dan penerangan, dan digunakan sebagai bahan bakar pure biogas dengan genset skala 2.500 watt. produksi biogas rata-rata sebesar 0,040 m3 per 30 menit atau 0,080 m3/jam. biogas yang dihasilkan selama pengukuran (450 menit) adalah 0,604 m3. dengan data tersebut maka diperkirakan dalam sehari (24 jam) biogas yang dapat dihasilkan adalah sebesar 1,92 m3. sementara, konsumsi biogas untuk genset pada beban 1.047 w adalah 0,019 m3/menit, genset akan beroperasi selama 101,05 menit atau sekitar 1,68 jam. dengan demikian listrik yang dapat dihemat adalah 1,759 kwh per-hari atau 52,77 kwh per-bulan dan biaya listrik yang dapat dihemat yaitu sebesar rp. 40.896/bulan. kata kunci: biogas, pure biogas, pilot plant, anaerobik. abstract utilization of biogas from cow manure as a fuel alternative for power plants is done through an anaerobic process. a pilot plant with biogas production of 7 m3/day has been installed at pesantren saung balong. biogas is used for everyday purposes such as cooking and lighting, and used as pure biogas with 2.500 watt scale generator. biogas produced with the rate of 0.080 m3/hr. biogas produced during the measurement (450 minutes) is 0.604 m3. with these data it is predicted that within a day (24 hours) biogas which can be generated is equal to 1.92 m3. meanwhile, consumption of biogas to the generator with 1.047 w load is 0.019 m3/minutes, the generator will operate for approximately 101.05 minutes or 1.68 hours. thus electricity that can be saved is 1.759 kwh per day or 52.77 kwh per month and electricity cost that can be saved that is equal to rp.40.896/month. keywords: biogas, pure biogas, pilot plant, anaerobic. i. pendahuluan pemanfaatan sumber energi terbarukan yang berasal dari sumber non-fosil seperti sampah perkotaan, kotoran ternak, limbah pertanian dan sumber biomasa lainnya saat ini menjadi semakin penting. biogas merupakan sumber energi terbarukan yang dihasilkan oleh fermentasi anaerobik dari bahan organik. biogas dapat diproduksi dari limbah kotoran hewan, air limbah, dan limbah padat. komposisinya bervariasi, tergantung sumber bahan biogasnya. akan tetapi, biasanya memiliki kandungan 50–70 % ch4, 25– 50 % co2, 1–5 % h2, 0,3–3 % n2 dan h2s [1][2]. biogas merupakan sumber energi yang menarik untuk daerah pedesaan khususnya di negaranegara berkembang [3]. salah satu karakteristik yang menarik adalah biogas dapat diproduksi mendekati titik konsumsinya sehingga sangat ideal untuk pembangkit listrik yang terdesentralisasi di daerah pedesaan terpencil. di sisi lain, biogas juga dapat diproduksi pada skala yang lebih besar dari bahan limbah perkotaan dan digunakan untuk menghasilkan listrik bagi masyarakat setempat [4]. teknologi biogas telah berkembang sejak lama namun aplikasi penggunaannya sebagai sumber energi alternatif belum berkembang secara luas. beberapa kendala antara lain yaitu kekurangan kemampuan teknis, reaktor biogas tidak berfungsi akibat bocor/kesalahan konstruksi, desain reaktor tidak http://dx.doi.org/10.14203/j.mev.2011.v2.73-78 kajian biogas sebagai sumber pembangkit tenaga listrik di pesantren saung balong al-barokah, majalengka, jawa barat (maulana arifin, a. saepudin, a. santosa) jmev 02 (2011) 73-78 74 user friendly, penanganan masih secara manual dan biaya konstruksi yang mahal [5]. di pesantren saung balong telah dibuat pilot plant biogas dengan produksi biogas sekitar 7 m3/hari. biogas ini dimanfaatkan untuk keperluan sehari-hari seperti memasak dan penerangan, dan digunakan sebagai bahan bakar pure biogas dengan genset skala 1.000-10.000 watt dan skala 10 kw dengan system dual fuels dan telah dibuat teknologi pengayaan biogas melalui proses absorpsi dan teknologi pengisian biogas kedalam tabung. listrik yang dihasilkan dari instalasi biogas di pesantren saung balong al barokah digunakan untuk mengurangi ketergantungan terhadap listrik yang di peroleh dari perusahaan listrik negara (pln). tujuan penelitian ini adalah untuk mengetahui bagaimana potensi penggunaan biogas pada pilot plant yang sudah terinstalasi, sehingga diharapkan hasil pengujian ini dapat digunakan sebagai tahap awal untuk mengetahui bagaimana potensi biogas sebagai sumber pembangkit listrik yang siap untuk dikomersialisasikan ii. metode penelitian penelitian dilakukan mennggunakan metode observasi dan studi literatur. a. observasi metoda ini dilakukan penulis dengan cara mengukur langsung parameter-parameter yang berkaitan dengan pilot plant biogas yang terinstalasi. pengujian produksi biogas bertujuan untuk mengetahui produksi biogas yang dihasilkan digester perhari yang ada di pilot plant biogas di pesantren saung balong al barokah. data produksi biogas digunakan sebagai indikator keberhasilan penerapan instalasi biogas dan digunakan pula untuk analisis kebutuhan biogas untuk bioelektrik pengukuran produksi biogas dilakukan dengan cara mengukur debit biogas yang keluar dari digester. pengukuran produksi biogas dilakukan selama 450 menit (7,5 jam) dari pukul 08:00 hingga 15:30 dengan pencatatan setiap 30 gambar 1. alat untuk pengukuran produksi biogas (biogas flow-meter, thermo-hygrometer digital). menit. pengukuran dilakukan dengan menggunakan alat biogas flow-meter, selain itu dilakukan pula pengukuran suhu ruangan dan kelembaban (rh) dengan alat thermohygrometer digital. pengujian biogas diawali dengan persiapan bahan baku yaitu kotoran sapi yang dihasilkan dari peternakan. kotoran sapi dicampur dengan air dalam bak pencampur dengan perbandingan 1:1 sampai campuran homogen dengan menghasilkan slurry. slurry tersebut didiamkan selama 30 menit dan kemudian dimasukan kedalam digester pada pukul 07:00 dengan volume slurry sebesar 0,105 m3. setelah satu jam, baru dilakukan pengukuran produksi biogas. b. studi literatur dalam hal ini penulis melakukan pencarian data literatur baik melalui internet, textbook, dokumentasi, jurnal ilmiah, dan sebagainya yang berhubungan dengan masalah biogas sebagai alternatif pembangkit listrik. iii. hasil dan pembahasan a. pengujian produksi biogas bioelektrik atau biotrik adalah istilah yang dipakai pusat penelitian tenaga listrik dan mekatronik – lipi untuk sebutan perangkat yang mengkonversi bioenergi (biogas) menjadi listrik. konversi biogas dilakukan dengan memodifikasi sistem bahan bakar pada genset konvensional sehingga menjadi genset biogas. biogas juga dapat digunakan dan dikombinasikan dengan bahan bakar solar (system dual fuels) untuk mendapatkan energi listrik yang lebih besar. sampai saat ini, bioelektrik masih dalam tahap pengembangan untuk menghasilkan energi listrik yang lebih besar. adapun spesifikasi untuk bioelektrik dapat di lihat tabel 1. gambar 2. digester dan genset biogas yang terinstalasi di pesantren saung balong, majalengka. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 73-78, 2011 p-issn 2087-3379 75 tabel 1. spesifikasi perangkat bioelektrik. spesifikasi keterangan digester tipe kubah tetap sistem pengumpanan batch (curah) kapasitas 7 m3 diameter 200 cm tinggi 390 cm bahan fiber glass, jenis resin eternal 2504 ketebalan bahan 3-5 mm jumlah ternak 6-20 ekor sapi dimensi bak slurry 350 x 100 x 30 cm penampung biogas bahan plastik polietilen dengan tebal 1 mm, kapasitas tampung 2m3 biogas kompor kompor biogas kualitas pabrik dengan satu perapian genset genset biogas 2.500 w dari literatur grafik hubungan waktu dengan produksi biogas (gambar 3), diperlihatkan kurva yang cenderung linier. pertambahan akumulasi produksi biogas bertambah seiring dengan waktu. akan tetapi setelah melewati 20 hari proses produksi biogas cenderung sedikit. sehingga dibutuhkan pemasukan slurry baru pada digester [6]. pada tabel 2, diperlihatkan data produksi biogas. dari tabel tersebut diketahui laju produksi biogas rata-rata sebesar 0,040 m3/30 menit atau 0,080 m3/jam. biogas yang dihasilkan gambar 3. grafik literatur rasio produksi biogas vs waktu – batch test (lfu 2007) [6]. tabel 2. produksi biogas untuk satu digester. waktu (menit) pembacaan alat (m3) pertambahan biogas (m3) akumulasi gas (m3) suhu ruangan (0c) rh (%) 0 1.638 0 0 27,4 85,0 30 1.677 0,039 0,039 27,8 80,0 60 1.716 0,039 0,078 28,9 76,0 90 1.768 0,052 0,130 28,9 73,0 120 1.807 0,039 0,169 29,4 73,0 150 1.875 0,068 0,237 29,4 68,0 180 1.906 0,031 0,268 30,3 64,0 210 1.972 0,066 0,334 32,1 59,0 240 2.005 0,033 0,367 31,4 56,0 270 2.060 0,055 0,422 32,0 55,0 300 2.088 0,028 0,450 31,7 54,0 330 2.144 0,056 0,506 31,9 55,0 360 2.180 0,036 0,542 33,3 51,0 390 2.198 0,018 0,560 33,4 51,0 420 2.238 0,040 0,600 32,5 52,0 450 2.242 0,004 0,604 32,0 55,0 480 0,600 0,6 0,6795 32,0 55,0 510 0,590 0,59 0,7223 32,5 52,0 540 0,560 0,56 0,7651 32,5 52,0 rata-rata 0,040 30,8 62,9 total 0,604 kajian biogas sebagai sumber pembangkit tenaga listrik di pesantren saung balong al-barokah, majalengka, jawa barat (maulana arifin, a. saepudin, a. santosa) jmev 02 (2011) 73-78 76 selama pengukuran (450 menit) adalah 0,604 m3. dengan data tersebut maka diperkirakan dalam sehari (24 jam) biogas yang dapat dihasilkan adalah sebesar 24 x 0,080 m3/jam = 1,92 m3. dari grafik hubungan waktu dengan produksi biogas (gambar 4), diperoleh kurva yang cenderung linier dengan nilai r2 = 0,9905. dengan demikian produksi biogas per satuan waktu dapat dikatakan konstan. adapun sedikit penyimpangan kemungkinan terjadi karena suhu lingkungan yang tinggi (27,4°c 33,4°c). idealnya suhu di dalam digester adalah 25°c dan diusahakan tidak terpapar langsung oleh sinar matahari. dengan adanya penghalang di atas digester diharapkan suhu di dalam digester tetap stabil pada kisaran 25°c. produksi biogas perhari hasil pengukuran masih belum optimal yaitu 1,92 m3. sedangkan jika digester (kapasitas 7m3) berfungsi dengan baik , diperkirakan dapat menghasilkan biogas sekitar 4-6 m3 perhari dengan syarat jumlah minimal campuran kotoran sapi dan air yang dimasukkan setiap harinya sebanyak 0,5 m3 (setara dengan kotoran yang dihasilkan 4-6 ekor sapi dewasa) dan kondisi lingkungan yang mendukung [7]. pada kenyataannya slurry yang dimasukkan kedalam digester hanya sebanyak 0,105 m3, sehingga biogas yang dihasilkan kurang dari 5 m3. untuk itu sebaiknya pemasukan slurry dilakukan sesering mungkin agar jumlah kotoran minimal yang harus dimasukan kedalam digester dapat terpenuhi. selain itu, diperlukan skala ukur pada bak slurry agar volume slurry yang dimasukan dapat diperkirakan supaya perbandingan antara grafik literatur dan grafik hasil pengujian cenderung sama, dimana pertambahan akumulasi produksi biogas bertambah seiring dengan waktu. akan tetapi setelah melewati 450 menit, proses produksi biogas cenderung sedikit. sehingga dibutuhkan pemasukan slurry baru pada digester. b. pengujian bioelektrik pengujian konsumsi biogas dilakukan dengan mengukur debit biogas yang masuk kedalam ruang bakar genset. biogas yang tertampung dalam penampungan disalurkan dengan pipa menuju genset. sebelum masuk genset, biogas terlebih dahulu masuk kedalam biogas flowmeter yang berfungsi untuk mengetahui debit biogas yang masuk kedalam genset persatuan waktu. pengukuran konsumsi biogas dilakukan pada beban listrik berbeda yaitu 0 w, 21 w, 221 w, 622 w, dan 1.047 w. pengukuran dilakukan selama 10 menit untuk masing-masing beban. hasil pengukuran dapat dilihat pada tabel 3. tabel 3. perbandingan konsumsi biogas pada beban listrik berbeda. beban listrik (watt) laju konsumsi biogas rata-rata (m3/menit) 0 0.018 21 0.019 221 0.021 622 0.020 1047 0.019 pada tabel 3 terlihat adanya perbedaan laju konsumsi biogas pada beban listrik berbeda. pada saat beban 0 w, 21 w, 221 w, laju konsumsi biogas meningkat seiring dengan beban listrik yang meningkat, namun pada beban 622 w, dan 1.047 w, laju konsumsi biogas kembali menurun dan sama seperti pada beban yang rendah (lihat gambar 5). hal ini kemungkinan terjadi karena pada awal pengujian (0 w, 21 w, 221 w) suhu genset belum mencapai optimal untuk proses pembakaran di dalam ruang bakar genset, sehingga konsumsi bahan bakarnya tinggi, sedangkan di akhir pengujian kemungkinan suhu di ruang bakar genset telah optimal untuk pembakaran sehingga konsumsi bahan bakarnya kembali menurun dan sama seperti awal pengujian walaupun beban listrik yang diberikan lebih besar. dengan demikian laju konsumsi biogas tidak dipengaruhi oleh beban listrik yang diberikan selama masih berada di bawah beban listrik maksimal yang mampu ditanggung genset (2,5 kw). oleh karena itu, penggunaan genset biogas akan lebih ekonomis apabila digunakan pada beban listrik yang besar. pada gambar 5, terlihat bahwa konsumsi biogas tertinggi yaitu pada beban listrik 221 watt dan terendah yaitu pada penggunaan tanpa beban 0 watt. sementara beban tertinggi yang dilakukan saat pengujian yaitu 1.047 watt dengan konsumsi biogas 0,019 m3/menit. konsumsi biogas dengan beban 1.047 watt ini menjadi dasar analisis penggunaan bioelektrik untuk penerangan, karena merupakan beban listrik minimal yang diperlukan untuk memenuhi kebutuhan listrik peternakan. dengan demikian, kebutuhan biogas untuk menyalakan genset selama 12 jam adalah : 12 x 60 menit x 0,019m3/menit = 13,68 m3 pada kondisi sebenarnya jumlah biogas yang diproduksi perhari hanya sebanyak 1,92 m3, untuk itu analisis bioelektrik tidak dilakukan untuk penerangan selama 12 jam, akan tetapi dilakukan selama biogas mencukupi untuk menyalakan genset. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 73-78, 2011 p-issn 2087-3379 77 gambar 4. grafik hubungan produksi kumulatif biogas dengan waktu. gambar 5. diagram konsumsi biogas pada beban listrik berbeda. c. analisis penggunaan bioelektrik untuk substitusi listrik pln analisis penggunaan bioelektrik bertujuan untuk mengetahui penghematan yang dapat diperoleh jika bioelektrik digunakan untuk substitusi listrik pln. penggunaan bioelektrik diharapkan dapat mengurangi pengeluaran dari penggunaan listrik, penggunaan bioelektrik diutamakan pada saat beban puncak yaitu pada pukul 18:00-20:00, karena pada waktu tersebut biaya listrik per kwh paling tinggi sehingga memungkinkan untuk lebih menghemat biaya pengeluaran. dari pengujian produksi biogas diketahui bahwa jumlah rata-rata biogas yang dihasilkan digester adalah sebanyak 1,92 m3/hari. sementara, konsumsi biogas untuk genset pada beban 1.047 kw adalah 0,019 m3/menit. dari data tersebut maka lama genset beroperasi dapat ditentukan dengan perhitungan sebagai berikut : lama genset beroperasi = produksi biogas biogas untuk genset = 1,92 m3 0,019𝑚𝑚3 /𝑚𝑚𝑚𝑚𝑖𝑖𝑖𝑖𝑜𝑜 = 101,05 menit dari hasil perhitungan, genset akan beroperasi selama 101,05 menit atau sekitar 1,68 jam. dengan demikian listrik yang dapat dihemat adalah 1,047 kw x 1,68h = 1,759 kwh per hari atau 52,77 kwh per bulan. jika biaya kwh listrik pln adalah sebesar rp. 755/kwh (pt. pln 2011), maka biaya listrik yang dapat dihemat yaitu sebesar rp. 40.896/bulan. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 pr od uk si b io ga s (m 3 ) waktu (menit) produksi biogas linear (produksi biogas) y = 0,0014x + 0,0086 r2 = 0,9905 0.0165 0.017 0.0175 0.018 0.0185 0.019 0.0195 0.02 0.0205 0.021 0.0215 0 21 221 622 1047 ko ns um si b io ga s (m 3/ m en it ) beban listrik (watt) 0,018 0,019 0,021 0,020 0,019 kajian biogas sebagai sumber pembangkit tenaga listrik di pesantren saung balong al-barokah, majalengka, jawa barat (maulana arifin, a. saepudin, a. santosa) jmev 02 (2011) 73-78 78 iv. kesimpulan berdasarkan hasil pengujian dan analisis dalam penelitian ini, dapat disimpulkan sebagai berikut: 1. penggunaan instalasi bioelektrik sebagai pembangkit listrik tenaga biogas di pesantren saung balong belum menghasilkan prosuksi biogas yang optimal. berdasarkan teori digester berkapasitas 7 m3 seharusnya dapat menghasilkan 4-6 m3 biogas perhari, sedangkan kenyataannya produksi biogas hanya 1,92 m3 perhari. 2. kurangnya produksi biogas dapat disebabkan beberapa faktor diantaranya faktor suhu yang terlalu tinggi, kurangnya kotoran yang dimasukan kedalam digester, perbandingan campuran slurry yang tidak homogen. 3. konsumsi biogas untuk genset pada beban yang berbeda relatif sama yaitu berkisar antara 0,018 0,021 m3/menit sehingga tidak ada terpengaruh beban listrik dengan konsumsi biogas. konsumsi biogas pada beban listrik tertinggi (1.047 watt) adalah 0,019 m3/menit. 4. penghematan yang diperoleh dari penggunaan seperangkat instalasi bioelektrik yang terdiri dari satu genset (daya maksimal 2,5 kw) dan satu perangkat digester (kapasitas 7 m3) adalah sebesar rp. 40.896/bulan. 5. perbandingan antara grafik literatur dan grafik hasil pengujian cenderung sama, dimana pertambahan akumulasi produksi biogas bertambah seiring dengan waktu. ucapan terima kasih penulis mengucapkan terimakasih kepada pusat penelitian tenaga listrik dan mekatronik lipi melalui program dipa tahun 2010 atas sumber dana dan kesempatan yang diberikan untuk penelitian ini, teman-teman di bidang sarana penelitian yang telah membantu dalam penelitian ini, bapak hoeruman sebagai pimpinan pesantren saung balong, zana fauzilah mahasiswa praktek kerja lapangan dari faperta unpad yang telah mengambil data-data di lapangan, serta semua pihak yang tidak dapat disebutkan satu persatu. daftar pustaka [1] r. sitthikhankaew, s. predapitakkun, r. kiattikomol, s. pumhiran, s. assabumrungrat, n. laosiripojana, “performance of commercial and modified activated carbons for hydrogen sulfide removal from simulated biogas,”in proceeding of conference on ieee first conference on clean energy and technology (cet), 2011, 27-29 june 2011, pp 135-139. [2] tran minh tien, pham xuan mai, nguyen dinh hung, huynh thanh cong, “a study on power generation system using biogas generated from the waste of pig farm”. in proceeding of international forum on strategic technology (ifost) 2010, 13-15 oct. 2010, pp 203 207. [3] jawurek, h.h., lane, n.w. and rallis, c.j., “biogas/petrol dual fuelling of si engine for rural third use,” biomass, volume 12, 1987, pp. 87-103. [4] jiasheng guo, chaokui qin, schmitz, g., “numerical investigation on the performance of spark ignition engine used for electricity production fuelled by natural gas/liquefied petroleum gas-biogas blends with modelica,“ in proceeding of 2nd international conference on computer engineering and technology (iccet) 2010, vol 6, 16-18 april 2010, pp 682-687. [5] teguh wikan widodo, ahmad asari, ana n., dan elita r., “rekayasa dan pengujian reaktor biogas skala kelompok tani ternak,” jurnal enjiniring pertanian, volume 4, nomor 1, pp. 41-52, april 2006. [6] l. sasse, biogas plants. a publication of the deutsches zentrum für entwicklungstechnologien gate in: deutsche gesellschaft für technische zusammenarbeit (gtz) gmbh, 1988. [7] deublein and a. steinhauser, biogas from waste and renewable resources. germany: wiley-vch verlag gmbh & co. kgaa, germany, 2008. [8] k. von mitzlatf, engine for biogas. germany: deutsche gesellschaft für technische zusammenarbeit (gtz) gmbh, 1988. [9] robert. d zucker and oscar b., fundamental of gas dynamics. department of aeronautics and astronautics naval postgraduate school monterey, california: john wiley & sons, inc., 2002. [10] t. al seadi, d. rutz, h. prassl, m. köttner, t. finsterwalder, s. volk, r. janssen, biogas handbook. esbjerg, denmark: university of southern denmark esbjerg, niels bohrs vej 9-10, dk-6700, october 2008. optimization for biogas power plants using automatic control of gas pressure mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.9-16 optimization for biogas power plants using automatic control of gas pressures dodiek ika candra a,b,*, camilo andreas wilches tamayo b aresearch centre for electrical power & mechatronics, indonesian institute of sciences kampus lipi, jl. sangkuriang gd. 20, bandung 40135 indonesia bbwe biogas-weser-ems gmbh & co. kg zeppelinring 12-16 26129 friesoy, the germany received 19 february 2013; received in revised form 02 april 2013; accepted 03 april 2013 published online 30 july 2013 abstract in many cases, gas storages on biogas power plants are not used optimally to store gas as much as their capacity. the digester is sometimes overload to store gas and the controller cannot deliver gas to other storage. consequently, gas is often released from digester to avoid over pressure. at the end, biogas power plant has less efficiency. hence, a mechanism to control gas pressure to make different pressure between its storages is required. fans were used to manipulate the most majority system pressures on a biogas power plant using frequency converters. measurements, simulations, and experiments were conducted to create a new system on a biogas power plant. a controller, programmable logic controller was used to control the entire system pressure using proportional-integral-derivative algorithm. when the gas pressures are not in the allowable range of pressure, then the controller changes the fans’ frequency to the desired conditions. as a result, gas moves to another storage and system pressures are in the allowable range. keywords: control biogas pressures, biogas storages optimization, biogas system pressure. i. introduction the company biogas-weser-ems (bwe) gmbh & co. kg built a biogas power plant in rhedegermany in 2010 with feeding from maize silage, chicken and pig manure. the produced biogas is delivered to two combine heat and power chp units to generate electricity. the plant was chosen because of long record of stability measurements and the owner’s interest to improve the efficiency of his biogas power plant. table 1 [1] shows detailed information of investigated biogas power plant. this research is aimed to investigate the system pressure behavior, the effect to the connected system, and to optimize gas storage utilization. the gas pressures were very small and fluctuate (see figure 1). the blue graph is gas pressure on digester and green graph is gas pressure on post digester. this condition leads a risk for biogas power plant such as construction damage. at the end, it can reduce lifetime of the biogas power plant. gas storage utilization also was the problem of this plant. gas volume on digester was always at maximum level, while on post digester was close to minimum level. figure 2 shows the example gas volume conditions (in m3) on digester (red graph) and post digester (green graph) respectively to their maximum volume. gas volume stored in digester was higher than gas volume stored in post digester. at some points, the conditions were difficult to be stored for the controller due to limitation of the acquisition process. finally, some systematical errors for the biogas power plant were generated. ii. methodology a. current control system investigation this step is aimed to investigate current control system of biogas power plant especially the pressures controller. the installed devices on investigated biogas power plant were below: 1) fan small fan were used to manipulate gas pressure inside the digester and post digester tanks. there were 2 types of fan used on this research, dng 2-4.8_10-50hz and dng 3-6_10*corresponding author. tel: +62-8121-9601-835 e-mail: dincandra@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.9-16 d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 10 50hz type. they rotate at the same frequency, but generate different pressure [1]. in the beginning, two fans of dng 3-6_10-50hz with fixed frequency at 50 hz for digester and post digester were used. but, at the end, users decided to add frequency converter for each installed fan. user can regulate fans’ frequency to the desired frequency by using frequency converters. on the other hand, the allowable regulated gas pressure was determined by the desired gas pressure between minimum and maximum range. figure 3(a) shows installed fan on biogas power plant and figure 3(b) shows installed fan on digester tank. 2) under/over pressure relief devices figure 4 shows over/under pressure relief device. the device was used to maintain system pressure by giving signal to controller to activate fan to create certain pressure. 3) volume meter volume meters were used due to the regulations that gas volume on digester and post digester should not exceed the standard [2]. 4) plc siemens s7/300-et200s programmable logic controller plc could not provide biogas system pressure correctly in the beginning. losses gas from digester tank was higher than delivered gas to post digester tank. 5) manometers manometers were installed on digester and post digester tank. these sensors were used to measure actual pressure inside the tanks. but, they were not giving a signal to the actuators (fan) regard to the instability of system pressure. during the research, these manometers have been replaced by pressure sensors, so they could be connected to plc. the mechanism created by current controller was not working properly to control systems pressures of the plant. fans were used only for single pressure. the controller could not identify the entire gas conditions and was not able to decide whether pressures should be changed or kept constant. moreover, other gas conditions such as temperature or volume were not considered on the algorithm. b. other studies in assistance of fh köln, online measurements, models and optimization methods were developed. online measurements were used to characterize the operating values and to develop implementation of anaerobic digestion model 1 (adm1) on matlab [3]. the intelligent system for non linear digester using fuzzy [4] and the comparison among different types of controller such as proportional-integraltable 1. investigated biogas power plant specifications description value unit digester diameter 22 m total height 6 m volume brutto 2,281 m3 volume netto 1,977 m3 post digester diameter 32 m total height 6 m volume brutto 4,825 m3 volume netto 4,182 m3 input maize silage 17 ton/day chicken manure 5 ton/day pig manure 11 m3/day output chp 1 250 kw chp 2 250 kw electricity 38.8 % heat 45.2 % figure 1. gas pressure conditions in digester and post digester d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 11 derivative (pid) had been investigated. pid was used to control gas pressure [5]. the model of intelligent biogas power plant including smart control from other company [6] and also in a small scale biogas power plant [7] had been investigated. c. chosen control method many people used pid to control pressure [8] for hardware-in-loop (hil) applications as well as for non linear input/output [9]. it could be applied on a plc [10]. on the other hand, some researcher [11], [12] described how to use pid. they explained process control and how to manipulate variable respective to its set point using pid control algorithm. in case of investigated biogas power plant on this research, variable measurements were measured gas pressures on digester and post digester. the manipulated variables were gas pressures and disturbances were gas temperatures. the mathematic models and stepby-step of finding pid’s parameters and process could not be presented in this paper due to bwe company’s property right. d. pid controller in siemens s7/300 the siemens s7/300 et200s plc was used on this research as a controller device. simatic manager software was used to create a pressure controller program [13] and pid function block fb inside plc. there are three different types of pid controllers on this plc [13]. the first type is continuous control which can be found in function block fb 41. the second type is step control on function block fb 42 and the last type is pulse generator that can be found in function block fb 43. the continuous process measurements and actions were used by applying fb 41 [13] on the controller. the algorithms of pid are internally connected in parallel and can be activated or deactivated individually. the function block fb 41 allows the controller to use p, pi, pd, or pid in manual mode or automatic mode. the entire investigated biogas power plant was modeled by fh köln biologically and mathematically. fan outlet air post digester under/over pressure safety device fan digester under/over pressure safety device to chp 2 to chp 1 outlet air outlet air outlet air gas transport pipe (a) (b) figure 3. (a) fan locations in a biogas power plant; (b) installed fan on digester tank figure 2. the comparison between gas volume in digester and post digester tank d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 12 e. model algorithm figure 5 shows an algorithm to control gas pressure. the controller receives all values from pressure and volume sensor on digester and post digester. the values were processed in the controller. the controller decides the right actions for fans based on logic conditions. if the actual value is not in the allowable range, then adjusted pressure value is used as set point. figure 6 shows basic flowchart of gas pressures controller where ‘a’ is percent volume of gas in digester and ‘b’ is percent volume of gas in post digester. total logic conditions that have been built based on gas conditions, standard and desired outputs are 162 conditions. example logic is below: if volume (v) gas post digester < minimum setting percentage volume and v gas digester < minimum setting percentage volume and pressure (p) digester < minimum setting pressure and p post digester < minimum setting pressure and absolute differences between post digester and digester > absolute setting different pressure and v gas digester > v gas post storage then p digester and p post digester should be increased. iii. result and analysis step-by-step the controller operations are: 1. 1st step: scanning, sensing, scaling, and categorizing of data (volumes and pressures). 2. 2nd step: check conditions (less, equal, or more) then executed to the specific process (increase pressure, keep constant, or decrease pressure) individually. 3. 3rd step: looping to 1ststep. the controller measures the values from sensors, classifying them, processing, and then give a value to actuators. table 2 shows the setting pid parameters that found using mat-lab simulation. figure 7 shows the scaling function for gas pressure that was created on plc. in scaling process, pressure from sensor was scaled into range between 0 and 3.5 mbar then compared to minimum pressuremaximum pressure (save as pv). if gas pressure in digester or post digester is less than minimum pressure, then gas pressures are classified as pdig_less or psto_less. if gas figure 4. over/under pressure relief device biogas gas outlet over pressure gas inlet under pressure figure 5. block diagram of the algorithm d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 13 pressures value is in the range between minimum and maximum pressure then gas pressures are classified as pdig_norm or psto_normal. if the values are more than maximum pressure, then gas pressures are classified aspdig_over or psto_over. figure 8 shows a classification function of pressure condition. the two following figures, figure 9(a) and figure 9(b) show scaling function for gas volume on digester and post digester with different values. volume would be classified as v minimum if gas volume on digester or post digester is less than minimum percentage, v normal if in the range of minimum-maximum percentage, and v maximum if more than maximum percentage. the absolute difference percentage of gas volume was calculated by comparing the difference percentage of gas volume on digester and post digester. if the difference is less than minimum percentage level then the absolute difference percentage of gas volume is classified as normal, while other is classified as abnormal. an excerpt of algorithm psto,pdig , vsto,vdig start initialization vsto _max, vsto_min, vdig_max, vdig_min, a inequal b? storage full? digester full? y both p kept y increase p storage decrease p digester digester empty? n y y n n increase p digester decrease p storage y end storage empty? digester empty? y else n p dig= p dig max? decrease p digester n p dig = p dig min? n else increase p digester y p sto= p sto max? decrease p storage y p sto = p sto min? n else increase p storage y y figure 6. basic flowchart of gas pressures controller table 2. pid parameters description value sample time 0.00e+00 internal set point 0.00e+00 process variable in w#16#0 manual value 0.00e+00 proportional gain 2.00e+00 reset time t#20s derivative time t#10s time lag of the derivative action t#2s dead band width 0.00e+00 manipulated value high limit 1.00e+00 manipulated value low limit 0.00e+00 process variable factor 1.00e+00 process variable offset 0.00e+00 manipulated value factor 1.00e+00 manipulated value offset 0.00e+00 initialization value of the integral action 0.00e+00 disturbance variable 0.00e+00 cmp >=r en in1’’pv’’ in2minimum pressure ’’pdig_normal’’ cmp <=r en in1’’pv’’ in2 ’’pdig_less’’ not ’’pdig_over’’ minimum pressure maximum pressure cmp <=r en in1’’pv’’ in2 figure 8. classification function of gas pressures scale move en in eno out hi_lim lo_lim bipolar ret_val’’pdig’’ mw22 in out mw22 mw6 ’’pv’’maximum pressure scale minimum pressure scale i1.1 figure7. function of scaling pressure d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 14 to choose a set point for pid controller on digester and post digester is shown by figure 10(a) and figure 10(b). in these figures, different logics between digester and post digester tank were used based on desired condition on the biogas power plant. as an example case: if pressure p digester is normal and difference percentage of volume between two tanks is normal (<minimum limit) then p digester is maintained as it is. two pid function blocks were built during this research. an example pid block for digester can be seen in figure 11. a value of 7.1425 is used as factorization value in order to set pid result to the desired value. as a result, gas pressure on digester and post digester of new system stayed between the minimum and maximum value. as can be seen in figure 12, gas pressure on digester (red curve) and gas pressure on post digester tank (green curve) with new system are within allowable range of pressure. moreover, gas volume on digester and post digester (see figure 13) is also in the range between minimum and maximum percentage respectively to their maximum capacity. compared to the previous system (without regulating fans’frequency), the delivered gas to post digester was found higher as well as gas volume on post digester. figure 11. pid function block applied for digester ’’vdig’’ scale move en in eno out hi_lim lo_lim bipolar ret_valmw36 in out mw36 mw10 ’’scaled_vdig’’ maximum volume scale minimum volume scale i1.1 ’’vsto’’ scale move en in eno out hi_lim lo_lim bipolar ret_valmw38 in out mw38 mw12 ’’scaled_vsto’’ maximum volume scale minimum volume scale i1.1 (a) (b) figure 9. (a) function of scaling volume of digester; (b) function of scaling volume of post digester (b) figure 10. (a) algorithm to choose a set point of pid in digester tank; (b) algorithm to choose a set point of pid in post digester tank d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 15 iv. conclusion there are many aspects to optimize biogas power plant. technically, it can be done by gas storage, engine configurations, or feeding optimization. the system pressures controller on gas storage is one of this optimization. by regulating and controlling the system pressures, the biogas power plant was able to decide actions when gas should send to chp or just store it in the storage. in addition, pid control that was used in this biogas power plant brought a better system than previous system. gas pressures on digester and post digester were never reached their limits. furthermore, gas volumes on digester and post digester were found to reach the desired volume. in addition to that, the power plant’s efficiency was increased by reducing released gas on digester tank. in conclusion, the new system (after implementing pid controller) brought better effects for biogas power plant compared to the previous system. . figure 12. gas volume conditions on digester ( red curve) and post digester (green curve) in the new system figure 13. gas pressure conditions on digester and post digester in the new system d. i. candra and c. a. w. tamayo / mechatronics, electrical power, and vehicular technology 04 (2013) 9-16 16 acknowledgement the author would like to thank biogasweserems gmbh & co. kg and ppre staff of university of oldenburg for provided facilities and given opportunity to conduct this research. references [1] d. i. candra, "automatic control of gas pressures," university of oldenburg, germany 2012. [2] b. v. gmbh, "tragluftbauten: berechnung, ausführung, und betrieb," vol. din 4134, ed. berlin: beuth verlag gmbh, 1983. [3] c. wolf, et al., "biogas plant control and optimization using computational intelligence methods biogasanlagenregelung und -optimierung mit computational intelligence methoden," at automatisierungstechnik, vol. 57, pp. 638-649, 2009. [4] s. balasubramaniam, "non-linear fermenter with pressure dynamics," purdue 2010. [5] g. sanstede and e. m. robens, "system for automatic control of gas pressure," germany patent 3,516,429, 1967. [6] oekobit. ökobit smart control: supervision and monitoring of a new generation. available: http://www.oekobitbiogas.com/en/biogas-plant-monitoringwith-elsa.html [7] m. arifin, et al., "study of biogas for power generation at pesantren saung balong al-barokah, majalengka, west java," journal of mechatronics, electrical power, and vehicular technology, vol. 02, pp. 73-78, 2011. [8] s. driscoll, "the design and qualification of a hydraulic hardwarein-the-loop simulator," masters of science in mechanical engineering, mechanical engineering, school of mechanical engineering georgia institute of technology, georgia, 2005. [9] u. bakirdogen and m. liermann, "simulation study on pressure control using nonlinear input/output linearization method and classical pid approach," in the fluid power and motion control symposium (fpmc 2010), 2010. [10] a. vodencarevic, "design of plc-based smith predictor for controlling processes with long dead time," presented at the proceeding of the international multiconference of engineers and computer scientists 2010, hong kong, 2010. [11] p. prof. zoran vukic and o. kuljaca. (2002, lectures on pid controllers. (april, 2002). available: http://arri.uta.edu/acs/jyotirmay/ee4343/ labs_projects/pidcontrollers.pdf [12] j. a. shaw. the pid control algorithm how it works, how to tune it, and how to use it. 2. available: http://www.picvietnam.com/download/pi dcontrolbook2.pdf [13] siemens, "standard software for s7-300 and s7-400 pid control," siemens, ed., c79000-g7076-c516-01 ed. nürnberg: siemens ag automation group industrial automation systems, 1996. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 23-30, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.23-30 penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot noor cholis basjaruddin jurusan teknik elektro politeknik negeri bandung jl. gegerkalong hilir, ds. ciwaruga, kotak pos 1234, bandung jawa barat 40012, indonesia ppmteam@gmail.com diterima: 28 maret 2011; direvisi: 11 april 2011; disetujui: 23 april 2011; terbit online: 7 juli 2011. abstrak extended kalman filter (ekf) merupakan versi nonlinear dari tapis kalman dan merupakan tapis yang biasa dipakai pada estimasi peubah keadaan nonlinear. pada penelitian ini ekf diterapkan untuk mengolah ciri citra dari kamera tunggal yang terpasang pada end effector sebuah robot. data yang dihasilkan oleh ekf kemudian diolah untuk mendapatkan parameter gerak. simulasi sistem kendali servo visual dibangun dengan tujuan untuk meneliti penggunaanekf sebagai estimator sikap. hasil simulasi menggunakan program matlab menunjukkan bahwa ekf mampu mengestimasi sikap robot dengan baik. kata kunci: kendali servo visual, position-based visual servo, tapis kalman, estimator sikap. abstract extended kalman filter (ekf) is the non-linear version of kalman filter and the said filter is usually used in nonlinear state estimation. in this study ekf is applied to process the image features of a single camera mounted on the end effector of a robot. data generated by the ekf then is to be processed to obtain the motion parameters. simulation of visual servo control system was built with the aim to examine the use of the ekf as a pose estimator. the simulation results using matlab show that the ekf is able to well estimate the robot pose. keywords: visual servo control system, position-based visual servo, extended kalman filter, pose estimation. i. pendahuluan estimasi peubah keadaan nonlinier menjadi bagian dari teori estimasi yang terus dikembangkan. berbagai metode estimasi peubah keadaan nonlinier yang saat ini dikembangkan antara lain ekf, unscented kalman filter (ukf), dan particle filters [1]. sebagai estimator, ekf bisa digunakan pada berbagai sistem nonlinier seperti pada sistem kendali servo visual [2]. sistem kendali servo visual adalah sistem kendali yang memanfaatkan kamera sebagai sensor posisi. sistem kendali ini lazim dipakai pada robot canggih yang menggunakan kamera sebagai mata [3] [4]. ii. metode penelitian a. sistem kendali servo visual robot sistem kendali servo visual robotdengan kamera terpasang pada end effector dapat diterangkan dengan memperhatikan gambar 1. w𝑂𝑂 𝐵𝐵 dan w𝐸𝐸 𝐵𝐵 menyatakan posisi dan orientasi dari objek danend effector robot dalam kerangka base (dasar) robot. w𝐸𝐸 𝑂𝑂 dan w𝐸𝐸𝑟𝑟𝑚𝑚𝑟𝑟𝑟𝑟 𝑂𝑂 menyatakan posisi dan orientasi aktual dan yang diinginkan dari end effector robot dalam kerangka objek. ∆w𝐸𝐸 𝐸𝐸 adalah vektor galat dalam kerangka end effector. tujuan pengendalian robot adalah mengendalikan gerakan robot agar vektor galat menjadi minimum untuk nilai acuan w𝐸𝐸𝑟𝑟𝑚𝑚𝑟𝑟𝑟𝑟 𝑂𝑂 yang berubah. base object b ow b ew o ew oereffw e ew∆ gambar 1. hubungan vektor pada sistem. http://dx.doi.org/10.14203/j.mev.2011.v2.23-30 penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot (noor cholis basjaruddin) jmev 02 (2011) 23-30 24 gambar 2. blok diagram sistem. pada gambar 2 dapat dilihat blok diagram sistem. oeŵ adalah estimasi posisi dan orientasi end effector dalam kerangka objek yang diperoleh dari ekf. masukan ekf adalah vektor ciri f yaitu sebuah vektor satu dimensi yang mengandung informasi ciri. ciri citra dihasilkan dari ekstraksi citra yang ditangkap oleh kamera. b. estimasi sikap 3d menggunakan extended kalman filter langkah pertama dalam estimasi sikap relatif adalah membuat hubungan geometrik antara titik ciri yang terdefinisi di dalam kerangka objek dan hubungannya dengan titik-titik bidang citra di dalam kerangka kamera. lihat gambar 3. gambar 3. proyeksi citra ciri objek. keterangan gambar 3. oo xoyozo kerangka acuan objek oc xcyczc kerangka acuan kamera dengan sumbu zc berimpit dengan sumbu optik oi – xiyi kerangka acuan citra to j o j o j o j )z,y,(xp =  vektor koordinat dari titik ciri objek ke j di dalam kerangka objek tc j c j c j c j )z,y,(xp =  vektor koordinat dari titik ciri objek ke j di dalam kerangka kamera i j i j y,x proyeksi koordinat titik ciri ke-j di dalam kerangka citra karakteristik intrinsik kamera: f panjang fokus kamera px, py jarak didalam pixel sepanjang sumbu xi dan yi (m/pixel) transformasi koordinat-koordinat titik ciri kej di dalam kerangka objek yang berhubungan dengan koordinat di dalam kerangka kamera adalah: o j c j pψ)α,,r(tp φ+= (1) o jp dianggap diketahui dari model cad, [ ]tzy,x,t =  dan r(ϕ,α,ψ) adalah matrik rotasi. r(ϕ,α,ψ)=           − −+ +− ααα φψαφφψαφαφ φψαφφψαφαφ cc sc s cc css cc sss cs ss ssc csssc cc ψψ ψψ ψψ (2) dari gambar 3 dapat diturunkan persamaan lokasi titik ciri proyeksi di dalam kerangka citra, yaitu: c jy c ji jc jx c ji j zp fy y , zp fx x −=−= (3) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 23-30, 2011 p-issn 2087-3379 25 gabungan persamaan 1 dan 2 menghasilkan persamaan yang mendefinisikan lokasi ciri citra sebagai fungsi nonlinier dari parameterparameter sikap. c. algoritma tapis kalman tapis kalman mendefinisikan estimasi optimal dari state (keadaan) dengan dinamika yang terspesifikasi melalui sebuah model dinamika ruang keadaan linear dan pengukuran keluaran yang terdefinisikan sebagai fungsi linear dari keadaan. hal ini menganggap bahwa ratarata derau gaussian adalah nol pada masukan model dinamika dan pada kesalahan pengukuran keluaran. model dinamika menggambarkan gerakan objek relatif terhadap kamera dalam bentuk fungsi keadaan sistem yang didalamnya terkandung parameter sikap. jika objek diam yang diperhatikan, model dinamika ini hanya berhubungan dengan karakteristik dinamika robot. jika objek bergerak, gerakan relatif tidak akan terdefinisi. hal ini disebabkan perubahan gerakan relatif tidak dapat dinyatakan oleh sebuah model dinamika yang terstruktur, sehingga model dinamika pendekatan dibutuhkan. model yang dibangun didasarkan pada anggapan bahwa gerakan relatif dalam bidang 3d adalah relatif lambat terhadap laju cuplik dan cukup halus sehingga turunan pertama parameter sikap )ψαφ  ,,,z,y,x ( dapat dianggap tetap sepanjang periode cuplik. model dinamika sistem waktu diskrit seperti persamaan berikut: wk = awk-1 + γk (4) yang mana, w = [ ]t,,,,,,zz,,yy,,xx, ψψααφφ  γ = vektor derau gangguan, dianggap rataratanya nol dan derau gaussian dengan kovarian q t = periode cuplik k = waktu cuplik 1212 1 0 t 1 . . . 1 0 t 1 1 0 t 1 a x                                 = (5) keluaran model diberibatasan sebagai hubungan geometri antara pengukuran vision zk dari lokasilokasi titik citra dan vektor keadaan sistem wk. untuk model dinamika (persamaan 4), paling sedikit 6 persamaan pengukuran bebas yang dibentuk dengan menggunakan 3 ciri, dibutuhkan sehingga seluruh keadaan sistem teramati. perhatikan (𝑋𝑋𝑗𝑗 0 , 𝑌𝑌𝑗𝑗 0 , 𝑍𝑍𝑗𝑗 0 ) , j = 1,2,3 adalah koordinat tiga citra dan �𝑋𝑋𝑗𝑗 𝑤𝑤, 𝑌𝑌𝑗𝑗 𝑤𝑤� 𝑘𝑘 adalah pengukuran ke-k lokasi ciri citra yang berhubungan. model keluaran tapis kalman dapat diturunkan sebagai, zk = g(wk) + vk (6) yang mana, [ ]tk,,,,, i3i3i2i2i1i1k yxyxyx z = (7) t k ,,,,,         = c 3y c 3 c 3x c 3 c 2y c 2 c 2x c 2 c 1y c 1 c 1x c 1 k zp y zp x zp y zp x zp y zp x f )w(g (8) vk adalah derau pengukuran yang dianggap termasuk dalam derau gaussian rata-rata nol dengan kovarian r. disebabkan keluaran model nonlinier, maka dibutuhkan tapis kalman terluaskan (extended kalman filter). ekf berfungsi sebagaimana sebuah sensor posisi dinamis yang menerima pengukuran citra kasar sebagai masukan dan menyiapkan parameter sikap terestimasi pada setiap terjadi pencuplikan. persamaan rekursif untuk ekf diberikan sebagai berikut: persamaan prediksi, 1-k1,-k1-kk, ˆˆ waw = (9) 1-k t 1-k1,-k1-kk, qaapp += (10) penguatan kalman -1t k-1kk,k t k-1kk, )cpcr(cpk k+= (11) pembaharuan estimasi, ))ˆ((ˆˆ k -1kk,-1kk,kk, wgzkww −+= (12) -1kk,-1kk,kk, pkcp p k−= (13) penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot (noor cholis basjaruddin) jmev 02 (2011) 23-30 26 d. matrik q dan r matrik q adalah matrik kovarian yang berhubungan dengan derau gangguan dinamik pada model sistem, sedangkan matrik r adalah matrik kovarian yang berhubungan dengan derau pengukuran pada model keluaran sistem. derau gangguan dinamik pada model sistem menggambarkan pengaruh dari pengabaian bentuk turunan orde tinggi dari tiap parameter sikap. atas dasar itu maka pembobotan dalam matrik q hendaknya dipilih lebih besar untuk perubahan yang lebih cepat pada parameter gerak dan dipilih pembobotan lebih kecil untuk perubahan lebih lambat dari parameter gerak. jika dianggap derau gangguan pada model sistem hanya terjadi pada parameter keadaan kecepatan )ψαφ  ,,,z,y,x ( , maka pembobotan matrik q yang berhubungan dengan parameter keadaan posisi )ψαφ ,,z,y, x,( dapat dipilih nol. pembobotan matrik q yang berhubungan dengan kecepatan dapat diperoleh melalui perhitungan variansi galat kecepatan dari beberapa data. matrik kovarian r dapat ditentukan berdasarkan variansi galat pengukuran ciri citra ),i yx( i dari beberapa data. derau pada model sistem maupun derau pada pengukuran keduanya dianggap tidak berkorelasi, merupakan derau putih dan memiliki fungsi kepadatan probabilitas gaussian dengan rata-rata nol. anggapan bahwa derau tidak berkorelasi memberi kemudahan dalam pemilihan bentuk matrik q dan r. bentuk matrik yang sesuai dengan anggapan tersebut adalah matrik diagonal dan elemen-elemen diagonalnya merupakan variansi galat proses untuk q serta variansi galat pengukuran untuk r. anggapan bahwa rata-rata dari fungsi kepadatan gaussian adalah nol memudahkan dalam perhitungan variansi galat. variansi galat dengan anggapan tersebut adalah sama dengan nilai rata-rata kuadratnya. e. diagram alir simulasi gambar 4 menunjukkan diagram alir simulasi penggunaan ekf sebagai estimator sikap robot. program simulasi diawali dengan penentuan sikap end effector terhadap objek yang dikehendaki (weoref), posisi objek terhadap base robot (wob), jumlah iterasi ekf (k), lama waktu simulasi (t) dan sikap robot pada saat awal simulasi. masukan yang diberikan pada program adalah matrik bobot q dan r. saat awal simulasi perhitungan kinematika balik didasarkan pada selisih weoref dan sikap robot pada saat awal simulasi. nilai sudut sendi robot kemudian digunakan untuk perhitungan persamaan dinamika dan kinematika. hasil perhitungan tahap ini adalah sikap robot terhadap base (web). sikap robot kemudian dibandingkan dengan posisi objek terhadap base (wob) dan hasilnya adalah weo yaitu posisi endeffector terhadap objek. posisi objek bisa dikenali oleh kamera yang ada di endeffector. ciri yang dihasilkan oleh kamera kemudian diestimasi oleh ekf secara iteratif menggunakan persamaan (9)-(13). hasil estimasi posisi endeffector adalah weoekf. hasil estimasi ini kemudian dibandingkan dengan weoref dan diperoleh selisih sikap yang terjadi dengan sikap yang dikehendaki (∆wee). gambar 4. diagram alir simulasi. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 23-30, 2011 p-issn 2087-3379 27 hasil estimasi kadang terlalu jauh dari yang dikehendaki, hal ini mengakibatkan robot tidak bisa mencapai posisi tersebut. secara matematis kondisi ini ditandai dengan tidak terpecahkannya persamaan kinematika (divergen). pemilihan matrik q dan r yang tepat bisa mengatasi masalah ini [5]. iii. hasil dan pembahasan pada penelitian ini dibangun program simulasi untuk mengamati kerja ekf dalam mengestimasi sikap robot. simulasi dibangun menggunakan program matlab dengan robotic toolbox. pemilihan matrik q dan r menjadi fokus dalam simulasi ini. simulasi bagian pertama bertujuan untuk meneliti pengaruh pemilihan matrik q. pada simulasi ini dipilih matrik r tertentu dengan matrik q berubah-ubah. simulasi bagian kedua bertujuan untuk meneliti pengaruh pemilihan matrik r. pada simulasi ini dilakukan sebaliknya, matrik q dipilih tetap dan matrik r berubah-ubah. a. pengaruh pemilihan matrik q pada simulasi ini matrik r dianggap tetap yaitu matrik diagonal dengan elemen diagonal 1000. hasil simulasi yang ditampilkan dalam gambar hanya untuk posisi sikap robot. hasil simulasi untuk orientasi sikap robot ditunjukkan dalam bentuk tabel. simulasi 1;pada simulasi ini, r dan q adalah matriks diagonal dimana r berelemen 1.000 dan q berelemen 0,01. gambar 5 menunjukkan estimasi posisi sikap robot pada simulasi 1. simulasi 2; pada simulasi ini, r dan q adalah matriks diagonal dimana r berelemen 1.000 dan q berelemen 0 untuk pembobotan pada parameter sikap serta 1.000 untuk pembobotan tabel 1. perbandingan rata-rata galat estimasi antara simulasi 1, 2 dan 3. arah rata-rata galat estimasi simulasi 1 simulasi 2 simulasi 3 x -0,0064 0,0024 -0,0037 y 0,0016 0,0005 -0,0004 z -0,0008 -0,0024 -0,0000 r 0,0034 0,0038 0,0301 p -0,0011 0,0115 -0,0230 y -0,0040 0,0000 0,0049 pada laju sikap. gambar 6 menunjukkan estimasi posisi sikap robot pada simulasi 2. simulasi 3; pada simulasi ini, r dan q adalah matriks diagonal dimana r berelemen 1.000 dan q berelemen 0,1 untuk pembobotan pada parameter sikap serta 0 untuk pembobotan pada laju sikap. gambar 7 menunjukkan estimasi posisi sikap robot pada simulasi 3. berdasarkan simulasi 1 dan 2 dapat disimpulkan bahwa pemilihan matrik q berbentuk diagonal dengan elemen matrik dipilih nol untuk yang berhubungan dengan parameter posisi dan dipilih 1000 untuk yang berhubungan dengan parameter kecepatan menghasilkan kinerja ekf yang lebih baik untuk estimasi arah x dan y. hal ini mendukung anggapan awal bahwa derau gangguan dinamis terjadi pada parameter keadaan kecepatan ),,,z,y,x ( ψαφ  . kesimpulan yang sama juga didapat dari hasil simulasi 2 yang menunjukkan kinerja ekf yang lebih baik dibanding simulasi 3. perbandingan rata-rata galat estimasi pada simulasi 1, 2, dan 3 ditampilkan dalam tabel 1. b. pengaruh pemilihan matrik r pada simulasi ini matrik q dianggap tetap yaitu matrik diagonal dengan elemen 0.01. r adalah matrik diagonal dengan elemen 100.000. hasil simulasi estimasi posisi sikap robot pada simulasi ini dapat dilihat pada gambar 8. rata-rata galat estimasi pada simulasi ini dibandingkan dengan hasil simulasi 1 pada simulasi pengaruh pemilihan matrik q (iii.a) dan ditampilkan dalam tabel 2. hasil simulasi ini menunjukkan bahwa pembesaran nilai elemen matrik r akan menjadikan ekf lebih tepat dalam mengestimasi sikap robot pada arah x dan y. tabel 2. perbandingan rata-rata galat estimasi antara simulasi pemilihan matrik r dan pemilihan matrik q. arah rata-rata galat estimasi r=1000 r=100.000 x -0,0064 0,0024 y 0,0016 0,0005 z -0,0008 -0,0024 r 0,0034 0,0032 p -0,0011 0,0115 y -0,0040 0,0000 penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot (noor cholis basjaruddin) jmev 02 (2011) 23-30 28 gambar 5. estimasi posisi sikap robot pada simulasi 1. gambar 6. estimasi posisi sikap robot pada simulasi 2. gambar 7. estimasi posisi sikap robot pada simulasi 3. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 23-30, 2011 p-issn 2087-3379 29 gambar 8. estimasi posisi sikap robot dengan r berelemen 100.000 dan q berelemen 0,01. iv. kesimpulan extended kalman filter (ekf) dapat diterapkan sebagai estimator sikap robot pada sistem kendali servo visual. keberhasilan kerja ekf sebagai estimator sangat dipengaruhi oleh pemilihan matrik q dan r. pengamatan pengaruh matrik q bisa dilakukan dengan cara memilih satu matrik r dan mengubah matrik q hingga dicapai estimasi yang terbaik. selanjutnya pilih matrik q yang menghasilkan estimasi terbaik dan ubah matrik r sehingga dicapai estimasi yang lebih baik. berdasarkan penelitian elemen matrik q yang jauh lebih kecil dari elemen matrik r akan menghasilkan kerja ekf yang lebih baik. pada saat pelaksanaan simulasi perlu diperhatikan pemilihan matrik q dan r agar didapat konvergensi perhitungan kinematika tak langsung. penelitian ini dapat dikembangkan lebih lanjut dengan menggunakan metoda estimasi lain seperti adaptive kalman filter (akf), unscented kalman filter (ukf) atau particle filter (pf). daftar pustaka [1]. john l. crassidis, “survey of nonlinear attitude estimation methods”, journal of guidance, control, and dynamics, vol. 30, no. 1, january–february 2007 [2]. william j wilson, “visual servo control of robots using kalman filter estimates of robot pose relative to work-pieces”, proceedings ifac 12th world congress, page 9-399 to 9-404, sydney, 1993 [3]. pi. corke, “visual control of robot manipulators – a review”, visual servoing real-time control of robot manipulators based on visual sensory feedback, world scientific publishing,1993 [4]. pi.corke, “visual control of robots, high-performance visual servoing”, john wiley & sons inc, new york, 1996 [5]. noor cholis basjaruddin, “simulasi kendali servo visual dengan tapis kalman sebagai estimator sikap pada robot puma 560”, tesis, program pascasarjana itb, bandung, 2002 [6]. j.hill and wt park, “real time control of a robot with a mobile camera”, 9th, international symposium on industrial robots, pp-233-246, march 1979. [7]. ks.fu et.al, “robotics, control, sensing, vision and intelligence”, mcgrawhill international editions,singapura, 1987 [8]. luh, j.y.s et.al, “on-line computational scheme for mechanical manipulators”, trans. asme, j.dynamic systems, measurements and control, vol.120, pp.69-76 [9]. j.wang, wj.wilson, “3d relative position and orientation estimation using kalman filtering for robust control”, proceedings for the 1992 ieee robotics and automation conference, nice, france, may 10-15, 1992 [10]. pi. corke, “robotic toolbox (release 5)”, pinjarra hills, australia, 1999 [11]. rd klafter, ta. chmielewski, and m.negin, “robotic engineering an integrated approach”, prentice hall, usa, 1989 [12]. robert grover brown & patrick yc hwang, “introduction to random signals penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot (noor cholis basjaruddin) jmev 02 (2011) 23-30 30 and applied kalman filtering”, john wiley & sons inc, canada, 1997 [13]. koichi hashimoto, “visual servoing real time control of robot manipulator based on visual sensory feedback”, world scientific publishing, singapura, 1993 [14]. hutchinson, seth, “a tutorial on visual servo control”, ieee transactions on robotics and automation, vol.12 no.5, 1996 [15]. j. rajruangrabin, et.al, “simultaneous visual tracking and pose estimation with applications to robotic actors”,the 2008 international conference on image processing, computer vision, and pattern recognition, usa, 2008 [16]. jetto, leopoldo, “development and experimental validation of an adaptive extended kalman filter for the localization of mobile robots”, ieee transactions on robotics and automation, vol. 15, no. 2, usa,1999 [17]. arko djajadi, et.al, “a model vision of sorting system application using robotic manipulator”, telkomnika, vol.8, no.2 yogyakarta, 2010 mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.75-82 design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle aditya sukma nugraha a, *, bagus budiwantoro b , estiko rijanto a a research center for electrical power and mechatronics, indonesian institute of sciences komplek lipi jl. sangkuriang, bandung, 40135, indonesia b faculty of mechanical and aerospace engineering, institut teknologi bandung jl.ganesha 10, bandung 40132, indonesia received 24 september 2014; received in revised form 30 october 2014; accepted 30 october 2014 published online 24 december 2014 abstract this paper presents a design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle. such a rifle is used in a remote-controlled weapon system (rcws) or a turret where it is fixed using a two degree of freedom pan-tilt mechanism. a half car lumped mass dynamic model of armored vehicles was derived. numerical simulation was conducted using fourth order runge kutta method. various types of vibration absorbers using spring and rubber with different configurations are installed in the elevation element. vibration effects on horizontal direction, vertical direction and angular deviation of the elevation element was investigated. three modes of fire were applied i.e. single fire, semi-automatic fire and automatic fire. from simulation results, it was concluded that the parallel configuration of damping rubber type 3, which has stiffness of 980,356.04 (n/m 2 ) and damping coefficient of 107.37 (n.s/m), and carbon steel spring whose stiffness coefficient is 5.547 x 10 6 (n/m 2 ) provides the best vibration absorption. keywords: vibration absorber, spring, rubber, armored vehicle, rifle. i. introduction turret and rcws play important role in modern security and defense instruments. they are composed offour main components i.e. rifle, mechanism, sensing and controller. the rifle is fixed using a two degree of freedom pan-tilt mechanism. its shooting direction should be stabilized against external disturbance. kinematics stabilization of a pan-tilt mechanism has been reported [1]. effectiveness of stabilization methods using invers angle and inertia measurement unit (imu) has also been investigated [2, 3]. sift and surf methods can be used for object recognition system in a turret or rcws [4]. such a turret or rcws may be installed in a mobile robot for special missions [5, 6]. experiment has been carried out to identify precision tolerance as a function of distance of a weapon system as shown in figure 1 [7]. in order to improve precision of the weapon system, modern automotive technology adopts two vibration attenuation approaches i.e. pasive and active [8, 9]. this paper aims to improve vibration attenuation and shock absorption performance of a 5.56 mm caliber rifle armored vehicle fixed with two degree of freedom pan-tilt mechanism using passive approach. a dynamic model of armored vehicle is derived using half car lumped figure 1. angle deviation tolerance as a function of distance [7] * corresponding author: tel: +62-22-2503055 e-mail: adit003@lipi.go.id http://dx.doi.org/10.14203/j.mev.2014.v5.75-82 a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 76 mass approach [10-14]. parameter values of the dynamic model are determined based on mechanical characteristics [15-18]. fourth order runge kutta method has been used to solve the dynamic model [19,20]. numerical parameters used in the runge kutta method can be seen in table 1 [21]. ii. methodology when a turret or rcws is attached on a vehicle, the structure of the armored vehicle can be illustrated in figure 2. it consists of elevation component, azimuth component, platform, tires, and road. (m) and (m) represent horizontal and vertical dislocations of the elevation component. the rifle shooting angle is determined directly by the elevation component and the azimuth component using an appropriate control system. irregularity of the road generates external disturbance which should be compensated using stabilization method. characteristics of the tire and the platform also contribute to the performance of the system. it is assumed that the armored vehicle is simmetric. a half car lump mass model as shown in figure 3 is used to simplify the analysis of dynamical model of the armored vehicle. (n/m) and (n/m) denote horizontal and vertical stiffness coefficients of the elevation component while (n/m) and (n/m) are the azimuth component stiffness. , , and are the stiffness of the suspension at each tire, respectively. (n/m) and (n.s/m) represent stiffness coefficient and damping coefficient of each tire ( ). the elevation component has three degrees of freedom including horizontal dislocation, vertical dislocation and elevation angle (pitch). the azimuth component has two degrees of freedom including vertical dislocation and azimuth angle (yaw). the platform has 6 degrees of freedom including vertical dislocation and bouncing of the center of gravity of the platform as well as vertical discolation of each tire. thus, the overall model has 11 degrees of freedom. motion equations were derived from the dynamical model shown in figure 3. the model was used to analize dislocation and angular deviation of the center of gravity of the elevation component when an external force works on it. in this paper the external force is due to the rifle firing. parameter values of the vehicle platform and azimuth mechanism were obtained from the mobile robot in the laboratory at research centre for electrical power and mechatronics, indonesian institute of sciences. spring and damping rubber were used for vibration absorber in the rifle mounting as shown in figure 4. table 2, table 3 and table 4 list up some important parameter values related to the elevation mechanism, azimuth mechanism, vibration damping spring and rubber. table 1. numerical parameter of fourth order runge kutta [15] t x y 𝐚 t1= ti x1= xi y1= xi a1=a(t x y ) t2= ti + ∆t x2= xi + y1 ∆t y2= xi + a1 ∆t a2=a(t x y ) t3= ti + ∆t x3= xi + y2 ∆t y3= xi + a2 ∆t a3=a(t x y ) t4= ti + δt x4= xi + y3 δt y4= xi + a3 δt a4=a(t x y ) figure 2. weaponized vehicle structure figure 3. armored vehicle half car model a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 77 the rifle utilizes military bullet whose caliber is 5.56 mm x 45 mm. it can be used in three modes of firing i.e. single, semi automatic and automatic firing. in single firing mode, the shock force is 831 n which corresponds to the shock torque of 27 nm. the shock force and torque of both semi automatic and automatic firing modes can be calculated based on the geometry and location of the rifle mounting. the methodology is wrapped up in a flow chart illustrated in figure 5. 1) motion equation derivation of the half car model in figure 3. 2) parameter values setting based on values in table 2 to table 4. 3) numerical parameters setting of the fourth order runge kutta according to table 1. 4) numerical simulation using matlab ® application software. sampling time was set to 1 milli second. iii. results and discussion first, single fire mode was applied when only spring in table 2 was fixed in the rifle mounting. every type of the spring effect was investigated by changing one type after another. there exists four types of spring. during every simulation, three variables were recorded, namely: horizontal dislocation (mm), vertical dislocation (mm) and angular deviation (mrad) of the center of gravity of the elevation component. with the same configuration, simulation was conducted for semi-automatic mode and automatic mode rifle firing. table 2. parameters of the azimuth and elevation components simbol description values ma azimuth weight 8.08 kg me elevation weight 14.4 kg ia moment of inertia of azimuth component 0.412 kg.m 2 ie moment of inertia of elevation component 1.25 kg.m 2 ka1 stiffness coefficient at the first bushinng of the azimuth component 9x10 4 n/m ka2 stiffness coefficient at the second bushinng of the azimuth component 9x10 4 n/m ey vertical distance between the trunion and the axis of the shoot 0.0325 m table 3. parameter values of the spring [11, 12]. type material stifness(n/m 2 ) ka carbon steel 5.55 x 10 6 kb stainless steel 4.77 x 10 6 kc monel metal 2.99 x 10 6 kd brass 2.38 x 10 6 table 4. parameter values of damping rubber [13, 14] rubber hardeness stiffness (n/m) damping (ns/m) 1. soft 149,986.61 114.59 2. medium 244,605.26 144.48 3. hard 980,356.04 107.37 (a) (b) figure 4. vibration absorber in the rifle mounting; (a) the rifle mounted on the elevation element; (b) rifle mounting using spring a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 78 second, single fire mode was applied when only damping rubber in table 3 was fixed in the rifle mounting. every type of the damping rubber effect was investigated by changing one type after another. there exists three types of damping rubber. in the same way, during every simulation, three variables were recorded namely: horizontal dislocation (mm), vertical dislocation (mm) and angular deviation (mrad) of the center of gravity of the elevation component. with the same configuration, simulation was conducted for semi-automatic mode and automatic mode rifle firing. next, all possible combinations of serial and parallel configurations between spring and damping rubber were tested for single firing mode, semi automatic firing mode and automatic firing mode. figure 6 shows simulation results of single firing mode when only the spring was mounted. horizontal dislocation, vertical dislocation and angular deviation of the elevation element were plotted with time. figure 7 shows simulation results of single firing mode when only the rubber is mounted. horizontal dislocation, vertical dislocation and angular deviation of the elevation element were plotted with time. figure 8 shows shock force which was generated during semi automatic firing mode. the rifle was fired three times in 0.9 second. figure 9 shows simulation results of semi automatic firing mode when only spring was mounted. figure 10 shows simulation results of single firing mode when damping rubber type 3 was combined with spring in parallel configuration. horizontal dislocation, vertical dislocation and angular deviation of the elevation element were plotted with time. figure 11 shows simulation (a) (b) (c) figure 6. single firing mode (spring only); (a) horizontal dislocation; (b) vertical dislocation; (c) angular deviation figure 5. calculation flow chart a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 79 results of semi automatic firing mode when damping rubber type 3 was combined with spring in parallel configuration. simulation of automatic firing mode was conducted by firing the rifle 12 times in 0.9 second. its simulation results are similar to those of semi automatic ones. performance of single firing mode can be analyzed using simulation results shown in figures 6, 7 and 10. from figure 6 it can be observed that the spring of type a produces the smallest values of angular deviation (0.104 mrad), vertical dislocation (0.506 mm) and (a) (b) (c) figure 7. single firing mode (rubber only); (a) horizontal dislocation; (b) vertical dislocation; (c) angular deviation figure 8. rifle shock force in semi-automatic firing mode (a) (b) (c) figure 9. semi automatic firing mode (spring only); (a) horizontal dislocation; (b) vertical dislocation; (c) angular deviation a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 80 horizontal dislocation (0.104 mm). from figure 10 it can be noted that the parallel configuration of type a spring and type 3 rubber resulted in relatively small value of angular deviation (0.11 mrad), vertical dislocation (0.507 mm) and horizontal dislocation (0.112 mm). furthermore, this configuration performs vibration damping effect. however the damping effect in angular deviation is smaller than that in horizontal dislocation. performance of semi automatic firing mode can be analyzed using simulation result shown in figure 9 and figure 11. from figure 9, we know that the spring of type a exhibits the smallest values of angular deviation (1.103 mrad), vertical dislocation (9.127 mm) and horizontal dislocation (0.19 mm). from figure 11 it is obvious that the parallel configuration of type a spring and type 3 rubber provides relatively small values of angular deviation (1.26 mrad), vertical dislocation (9.15 mm) and horizontal dislocation (0.2 mm). further analysis has been done to observe effect of spring and rubber configuration on (a) (b) (c) figure 10. single firing mode with damping rubber type 3 and spring in parallel; (a) horizontal dislocation; (b) vertical dislocation; (c) angular deviation (a) (b) (c) figure 11. semi automatic mode with damping rubber type 3 and spring in parallel; (a) horizontal dislocation; (b) vertical dislocation; (c) angular deviation a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 81 displacement. figure 12 shows bode diagrams when using weak spring, the strong spring and the parallel configuration between damping rubber type 3 and spring a. it can be seen that the magnitude of each displacement against each parameter is different. the parallel configuration of spring a and damping rubber type 3 give the smallest peak magnitude both in horizontal displacement dan angular displacement. these results confirm the results shown in figure 6 to figure 11. iv. conclusion parallel configuration of damping rubber type 3, with stiffness of 980,356.04 (n/m 2 ) and damping coefficient of 107.37 (n.s/m), and carbon steel spring with stiffness coefficient of 5.547 x 10 6 (n/m 2 ) provided the best vibration absorption. in single firing mode, angular deviation of 0.1102 mrad, vertical dislocation of 0.5065 mm and horizontal dislocation of 0.1116 mm of the elevation component were produced. in both semi automatic and automatic firing modes, angular deviation of 1.2647 mrad, vertical dislocation of 9.1516 mm and horizontal dislocation of 0.2052 mm were produced. acknowledgement the authors would like to thank the indonesian institute of sciences, institut teknologi bandung, and indonesian ministry of research and technology for the opportunity and financial support in conducting this research. references [1] f. schillebeeckx, j. peirs, v. w. vijver, d. reynaerts, “compact zero-backlash tilp-pan mechanism based on differential gear technology,” 9 th international conference on new actuators, pp. 641-644, 2004. [2] w. e. dixon, d. m. dawson, e. zergeroglu malithong, “adaptive tracking control of a wheeled mobile robot via an uncalibrated camera system,” ieee transactions on systems, man, and cybernetics,vol. 31, pp.341-352, 2001. [3] h. m. saputra, z. abidin, e. rijanto, “imu application in measurement of vehicle position and orientation for controlling a pan tilt mechanism,” journal of mechatronics, electrical power, and vehicular technology,2013,vol.4,no.1, pp.41-50.doi:10.14203/j.mev.2013.v4.4150. [4] m. mirdanies, a. s. prihatmanto, e. rijanto, “object recognition system in remote controlled weapon station using sift and surf methods,” journal of mechatronics, electrical power, and vehicular technology, 2013, vol.4, no.2, pp.99-208. doi:10.14203/j.mev.2013.v4.99108 [5] r. p. saputra, e. rijanto, h. m. saputra. 2012. “trajectory scenario control for the remotely operated mobile robot lipi platform based on energy consumption (a) (b) (c) figure 12. bode diagram of vibration of firing arm; (a) horizontal displacement; (b) vertical displacement; (c) angular displacement a. s. nugraha et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 75-82 82 analysis,” international journal of applied engineering research, vol.7, no.8, pp.851866. [6] e. rijanto, r. p. saputra, h. m. saputra. 2013. “positioning control for the mobile robot lipi articulated robot arm based on pd control approach,” international journal of applied engineering research, vol.8, no.4, pp.423-433 [7] j. balla, “dynamics of mounted automatic cannon on track vehicle,” international journal of mathematical models and methods in applied sciences., vol.5, pp.423-432, 2011. [8] j. biti, “an investigation of damping supercar,” bachelor of engineering, school of mechanical and manufacture engineering, 2008. [9] d. c. akiwate, s. s. gawade, “design and performance analysis of smart fluid damper for gun recoil system,” international journal of advanced mechanical engineering, vol. 4, no. 5, pp. 543-550, 2014. [10] w. borkowski, p. rybak, z. hryciów, j. wysocki, k. papliĕski, b. michaáowski., “operational loads of combat vehicles,” journal of kones powertrain and transport, vol. 18, no. 1, 2011. [11] e. h. choi, j. b. ryoo, j. r. cho, o. k. lim, “optimum suspension unit design for enhancing the mobility of wheeled armored vehicles,” journal of mechanical science and technology, vol. 24, pp. 323-330, 2010. [12] s. sulaiman, p. m. samin, h. jamaluddin, r. a. rahman, m. s. burhaumudin, “groundhook control of semi-active suspension for heavy vehicle,” international journal of research in engineering and technology (ijret), vol. 1, no. 3, pp.146-152, 2012. [13] a. c. mitra, n. benerjee, “vehicle dynamics for improvement of ride comfort using a half car bondgraph model,” international journal of researchers, scientist and developers., vol 2, 1-5, 2014. [14] o. bayrakdar, “random vibration of road vehicle,” master thesis, master of science, izmir institute of technology, 2010. [15] schmid, hamrock, jacobson, fundamentals of machine elements, 3 rd , crc press, 2014. [16] g. stigliana, d. mundo, s. donders, t. tamarozzi, “advanced vehicle body contact modelling approach using reduced models of beams and joint,” in proceedings of isma, pp. 4179-4190, 2010. [17] f. l. neto, b. santos, “a procedure for the parametric identification of viscoelastic dampers accounting for preload,” j. of the braz. soc. of mech. sci. & eng., vol.xxxiv, pp. 213-218, 2011. [18] a. shirahatt, p. prasad, p. panzade, m. kulkarni, “optimal design of passenger car suspension for ride and road holding,” journal of the brazilian society of mechanical science and engineering, vol.xxx, pp. 66-76, 2008. [19] m. bayat, i. pakar, “on the approximate analytical solution to non-linear oscillation systems,” journal of shock and vibration, vol. 20, pp. 43-52, 2013. [20] h. yaghoobi, m. torabi, “an analytical approach to large amplitude vibration and post-buckling of functionally graded beams rest on non-linear elastic foundation,” journal of theoretical and aplied mechanics, pp. 39-52, 2013. [21] t. salau, k. a. olaiya, o. o. ajide, “simulation of oscillators dynamics using selected versions of fourth order rungekutta scheme,” international journal of engineering and technology vol.4 no. 8, pp. 444-450, 2014 mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.83-90 evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system sunarto kaleg a, *, aam muharam a , muhammad redho kurnia a , abdul hapid a a research centre for electrical power and mechatronics, indonesian institute of sciences komplek lipi, building 10, basement, jl. cisitu no. 154d, bandung, west java, 40135 indonesia received 30 october 2013; received in revised form 7 november 2014; accepted 10 november 2014 published online 24 december 2014 abstract the main target of a steering system is that the driver can change vehicle trajectory in accordance with the desired direction. power steering has become a standard feature in automobile. it provides assisting power when the driver turns the steering wheel. the well-known power steering types include; hydraulic power steering (hps), electro hydraulic power steering (ehps), and electric power steering (eps). ehps or eps uses an electronic control unit (ecu), which is specific for each vehicle. the ecu should be able to regulate power of electric motor to provide corresponding assisting power for the steering wheel. therefore, ecu requires input signals, one of which is vehicle wheel angle that can be indicated from the vehicle steering wheel angle. incremental type of rotary encoder (re) is used in steering angle sensor on a minibus. re specification used was 60 pulses per rotation and the minibus steering transmission specification is 3.5 round of right wheel off angle to the left whe el off angle. so we get the re angular resolution of 6º per pulse and 105 number of pulses to half of the steering transmission ratio. repeatability then was tested against a steering angle counter module. testing was done with a test cycle consisting 3 repetitions: condition center of the steering wheel, the steering wheel is turned to full right, then to the full left, then back to the right up to the steering wheel center. the results obtained were 2 pulses deviation, or equivalent to 12º of steering angle. keywords: vehicle steering system, rotary encoder, incremental, steering wheel angle, repeatability. i. introduction most of the vehicles that roam the city road are comprised of piloted vehicles such as cars, buses, and trucks. the trajectory is a tridimensional or planar curve, determined by a guidance system controlled by a human pilot. the guidance system acts by exerting forces on the vehicle that are able to change its trajectory [1]. steering system is constituted of several main components as described in figure 1: steering wheel, steering column, and steering transmission [2]. the steering wheel must be designed such it can be easily controlled and allows firm grip. it is made from composite and plastic enabling comfort and firm grip. the power which generated by the steering wheel is distributed to the steering transmission component through the steering column. the column is precisely and several segments built such that its axis is not in line with that of the steering transmission. the segments also contribute to the ergonomic steering wheel positioning. steering transmission amplifies the power applied by the driver which will be transmitted to the vehicle’s wheels. the effect of the reduction gear varies with vehicle type. suppose a sedan utilizes a steering system that exhibits steering transmission ratio of 16. this configuration should enable curving the car wheels angle of 40° for 1.7 rotations relative to the steering wheel center. two types of steering transmission are commonly used; rack-pinion type and screwsector or re-circulating ball bearing type. the first type, as seen in figure 2, is commonly used by passenger car or small cargo vehicle [2]. its versatility is mainly contributed by its simple mechanism, and favorable mechanical efficiency due to relatively low gear friction [1]. the direction of the forces acting on the steering transmission is parallel to lateral axis relative to the vehicle. this force causes the drivercontrolled wheel to have the same lateral forces acting on it as it was on the rest of the wheels. in * corresponding author: tel: +6222.2503055 e-mail: sunarto.kaleg@lipi.go.id http://dx.doi.org/10.14203/j.mev.2014.v5.83-90 s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 84 return, the driver’s ability to react to different kinds of road condition greatly enhanced. figure 3 shows the screw and sector type of steering transmission [3]. this type commonly used in middle class vehicle up to heavy cargo due to its compact transmission design that allows spacious engine room. it is quite beneficial compared to the previous type which forces the transmission to be placed right at the wheel axis. this type of transmission is composed of screw shaft that acts as the trajectory of the ball bearing causing minimal friction which in return greatly increases the mechanical transmission efficiency. despite these benefits, the driver may not be able to react accordingly as well as if the previous type was used. it is caused by the inability of the wheels to transfer the lateral force to the driver-controlled wheel. steering torque originated from the drivercontrolled wheel itself. however, the torque from the wheels cannot return to the driver-controlled wheel. power steering has become a standard feature in automotive. it provides assisting power when the driver turns the steering wheel. the wellknown power steering types include; hydraulic power steering (hps), electro hydraulic power steering (ehps), and electric power steering (eps). ehps or eps uses an electronic control unit (ecu), which is specific for each vehicle. nowadays, hps is commonly used in most vehicles. the energy source is originated from the hydraulic energy which is produced by the engine turned the fluid pump. excessive power of the engine enables hps to be able to be used properly in many situations. the fluid pump components and its tank is shown in figure 4. hps was deeply researched due to the increasing needs on high fuel efficiency, and strict gas emission standard. at low engine rotation, the power produced by hps is very low causing the steering wheel to be heavy when rotated especially for large curving angle. on the other hand, when the engine spins at high angular velocity, the necessary power needed to supply the fluid pump increases while the power needed to turn the steer decreases. hence, marking the flaw of hps which lies in energy efficiency [4]. in response to this matter, ehps was developed. it enables controlled and adjustable fluid pump mechanism relative to the vehicle speed and condition. its main component is electric motor figure 1. steering system scheme on the main components that constitute it [2] figure 2. rack and pinion-type steering transmission [2] figure 3. screw and sector-type steering transmission [3] s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 85 which is used to supply the fluid pump. the electronic control unit (ecu) controls the electric motor. the ehps scheme is depicted in figure 4. figure 4 also illustrates the ecu component which is integrated with the fluid pump [5]. the compact design enables the installation to be both flexible and integrated with steering transmission. finally, the fluid used in either ehps or hps is the same thus allowing it to be used in all types of vehicles. in eps, an electric motor can be directly connected either to the axis of steering transmission or to the steering column. figure 5 shows a column-type eps [6]. it is noticeable that eps is more compact than both hps and ehps. furthermore, by utilizing a proper ecu, an eps can produce the same power that is on par with both hps and ehps. both ehps and eps use ecu which is specific for each types of vehicle. in order to acquire suitable additional power, the ecu should be able to regulate the power produced by the electric motor. several factors are used as inputs for ecu including torque of the steering wheel, vehicle speed, angular speed of steering wheel, and wheels’ angle [1]. the ecu in the eps also uses the electric motor current as feedback signals to produce appropriate assisting power. however, when the power steering fails, such a steering system must allow a driver to take over manually. eps can independently design treatments of, for example, road surface information and disturbance information and steering safety and also can obtain safe, comfortable steering performance which is easily tunable has been proposed [7]. in line with intelligent transport system (its) trend, in the future, automatic controlled steering is predicted to be implemented [8-10]. nowadays, absolute-type optical sensor, such as rotary encoder (re), is commonly used. absolute-type re has an advantage in terms of the generated digital data that is ready to be processed. methode electronics released steering sensor which utilizes this type of sensor which has 1080° resolution [11]. moreover, its sensitivity is about 1.5°, and has been equipped with a computer that is able to detect both steering angle and steering rotation speed. as shown in figure 6, the light will go through combination of codes producing light patterns which will be sensed by the photocells. it will then be processed by the microprocessor whose result will be given to the ecu to regulate the response of electric motor according to the angle measurement. disadvantages of absolute-type re are it requires many photocells to be mounted and alignmented very precisely [12]. other disadvantage is that the disk made with unequal 1. steering column assembly 2. steering column with intermediate spindle 3. rack and pinion steering with external drive figure 5. illustration on column-type eps [6] figure 4. the scheme of electro-hydraulic power steering (ehps) [5] s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 86 spaced slots, make it expensive to be produced. the incremental-type re has only one disk of equally spaced slots. wheels’ angle is determined by counting the number of slots that pass the photocells. this type re only use two photocells for counting and convey the disk direction. so, it makes incremental-type re cheaper than the absolute-type re. this paper reports experiment results of angle sensor using incremental-type re to investigate its possibility to be used as a steering angle sensor. ii. incremental-type rotary encoder as angle sensor autonics e80h is a hollow shaped incremental-type re. this design, as shown in figure 7, aims to connect to steering column without any transmission medium such as gear or pulley. the output is frequency of two waves, a and b, and one reference wave named z. the shape of the superposition of the two waves is quadrature as shown in figure 8 [13]. pulse counter and direction determination are essential for re to be able to be used as a steering angle sensor. as seen in figure 9, direction can be determined by using two unique conditions of wave a relative to wave b. suppose; an incremental-type re has two waves namely a and b or v1 and v2. hence, when v2 is low while v1 remains high, the direction is counter-clockwise. on the other hand, when both v1 and v2 are low, the direction is clockwise. the obtained direction can be combined with v2 through and gate to count the pulse. the pulse increases when the re axis is rotated clockwise, and decreases when rotated counter-clockwise [12]. the pulses counter flowchart is shown in the figure 10, which is processed using microcontroller. steering shaft position is counted from cw (count of pulse a in form of clockwise) and reduced by ccw (count of pulse a in form of counter-clockwise), then multiplied with re resolution used. iii. accuracy and repeatability re was characterized by its resolution rather by its calculation accuracy. it is able to accurately detect motion while limited by the quality of the rotation [14]. suppose that an element deflection due to loading produces thread toleration of 0.1 inches. by using re whose resolution is about 1,000 pulse per rotation, a reading of 0.001 inches can be read. however, it will never be able to read a movement of about 0.1 inches. the accuracy of an re in steering system is determined by the precise reading of the pulse against the curving angle. the accuracy limitation of the steering system is affected by figure 7. incremental-type re e80h released by autonics [13] figure 6. steering sensor made by methode electronics [11] figure 8. the output of the wave a, b, and z [13] s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 87 tolerance value of the steering angle due to tolerances on mechanical components connections steering column, steering transmission and ball joint tolerance at the end of steering transmission with kingpins. repeatability is an re ability to show the same value when rotated from the reference point to some point, and then back to the same reference point. in terms of steering system, the reference point is the center of the steer, and the wheels are positioned parallel to each other; enabling the vehicle to move in straight path. if rotated clockwise and counter-clockwise, then two curves in first quadrant and third quadrants will be obtained respectively. figure 11 illustrates two curves in the first quadrant and third quadrant forming straight line bridging both quadrants. if the reference point is in the origin of the coordinate system (0, 0), then it is obvious that the ordinate will be negative to the left of the curve, and positive to the right of the curve. repeatability is affected by the pulse deviation which is typically occurs in optical re. this deviation is formulated as follows, (1) instrument error is an eccentric code, wrong pattern, worn-out bearing, and optics flaws. quadrature error is a combined effect of wave toleration, duty-cycle, and other variables in basic analog signals. interpolation error is an error that occurs when the re resolution raises after four calculations per optics cycle. suppose, re with resolution of 512 pulses per rotation was used for angle sensing. then, the angle resolution would be 0.703125° per pulse. the computer will interpolate this value until the allowed rounding point which causes pulse increment. quantization error is an error that is not originated form re but will always occur in digital instrumentation [15]. suppose we have digital number whose value is between 1 and 0, then this number must be quantized to either 1 or 0. iv. result on incremental-type re this type of re was used in the construction of steering sensor of a passenger car. the resolution of the re is 60 pulses per rotation while the specification of the steering transmission is 3.5 rotations relative from the figure 10. the flowchart process counting of steering shaft position figure 9. direction determination through v1 and v2 processing [3] s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 88 fixed angle of the right to the fixed angle of the left. the resolution of the re angle is formulated as follows, (2) using equation (2), if specification of re is 60 pulses per rotation, then the re angle resolution is 6 o per pulse. if the center of the steering wheel (the wheel facing straight forward) is half of the steering transmission ratio which is 1.75, then the number of pulses from the center of the steering wheel to the fixed angle of the wheels can be calculated using the formula, (3) the generated pulse is 105 relative from the center of the steering wheel to the fixed axis of the wheels. one cycle of tests comprised of 3 repeats; from the center of steering wheel, it was turned to the all the way right, and the all the way to the left and then back to the initial position. figure 12 shows the number of pulses within one cycle. the value is negative when the steer was turned left and positive when turned right. data sampling was taken in every 30 degree of steering wheel angle. then resulting total 133 data in one cycle. count 5 pulse in every data theoretically. from the tests, the relation between pulse deviation and number of tests was obtained as depicted in figure 12. figure 12 shows us that the highest pulse deviation is 2 pulses. the pulse figure 11. relation between steering angle and number of pulses figure 12. generated pulses versus pulse deviation within one cycle s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 89 deviation occurs in random data. it occurs when the encoder stops in the transition position i.e. position that does not generate one count. then it one count is added to next data. next, if the encoder stops in perfect position, there is no pulse deviation. the pulse deviation value can be converted to the actual angle deviation using the formula, (4) the angle deviation that occurred was 12°. figure 13 shows the value of steering angle tolerance is 5 degree. the angle deviation resulted by pulse deviation larger than permitted steering angle tolerance. these values will be used for developing methods to resolving re signal conditioning, less pulse deviation, resulting less angle deviation. however, an re which exhibits a much higher resolution to produce much smaller angle deviation produced, so that smaller angle deviation is can be used. v. conclusion ehps and eps are additional power system for the steering wheel which uses specific ecu for each vehicle types. power regulation of the electric motor is necessary to acquire the suitable additional power. one of the ecu inputs is the wheel’s angle which can be sensed using optical sensor such as rotary encoder (re). among the types of re, incremental type whose resolution is about 60 pulses per rotation was used. after repeatability tests, which comprised of 3 repeats; from the center of steering wheel, it was turned to the all the way right, and the all the way to the left and then back to the initial position. it produced pulse deviation of 2 pulses which equals to 12° of angle deviation. the angle deviation resulted by pulse deviation larger than permitted steering angle tolerance. these values will be used for developing methods to resolve re signal conditioning, less pulse deviation, resulting less angle deviation. references [1] g. genta and l. morello, the automotive chassis vol. 1: springer, 2009. [2] tenneco inc. (2011, 23 september). steering systems. available: http://www.monroe.com.au/tradecorner/tech-info/suspensionsystems/steering-systems.html [3] philippe. (2003, 23 september). steering system terms and how the system works. available: http://www.imperialclub.com/repair/steerin g/terms.htm [4] x. chang-gao, et al., "realization of control algorithm for electro-hydraulic power steering system based on mc9s08aw32 microcontroller," in international conference on informatics, cybernetics, and computer engineering (icce2011), melbourne, australia, 2011, pp. 581-589. [5] b. heißing and m. ersoy, chassis handbook, 1 ed.: vieweg+teubner, 2011. [6] d. a. crolla, automotive engineering, 1 ed.: butterworth-heinemann, 2009. [7] s. endo, et al., "electric power steering apparatus control apparatus," patent number: us 20050103561 a1, 2005. [8] j. m. armingol, et al., "ivvi: intelligent vehicle based on visual information," robotics and autonomous systems, vol. 55, pp. 904-916, 2007. [9] s. a. birrell and m. s. young, "the impact of smart driving aids on driving performance and driver distraction," transportation research part f: traffic psychology and behaviour, vol. 14, pp. 484-493, 2011. [10] v. milanés, et al., "intelligent automatic overtaking system using vision for vehicle detection," expert systems with applications, vol. 39, pp. 3362-3373, 2012. [11] methode electronics automotive group europe, "steering angle sensor for automotive applications," ed: methode electronics, 2007, p. 1. figure 13. toyota minibus steering angle tolerance measurement s. kaleg et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 83-90 90 [12] c. t. killian, modern control technology: components and systems, 2 ed.: delmar, 2001. [13] autonics corporation. (2007, 7 oktober). e80h series. available: http://id.autonics.com/products/products_det ail.php?catecode=01/06/01&db_uid=63 [14] danaher industrial controls, encoder application handbook. gurnee, il: danaher controls, 2003. [15] g. s. gordon. (1998 – 2002, 7 october). let's talk accuracy. available: http://www.gpi-encoders.com/ mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.1-8 rotor-dynamic characteristic evaluation of interior permanent magnet motor using finite element method hilman syaeful alam a, *, pudji irasari b a technical implementation unit for instrumentation development, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 30 bandung, 40135, indonesia. b research centre for electrical power and mechatronics, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 20 lantai 2 bandung, 40135, indonesia. received 27 december 2013; received in revised form 12 february 2014; accepted 12 february 2014 published online 23 july 2014 abstract dynamic characteristics of a critical speed of the rotor components at interior permanent magnet motor were evaluated using one-dimensional (1d) and three-dimensional (3d) finite element methods. critical speed of the rotor wasinvestigated in the campbell diagram, which shows the relationship between natural frequency and rotational velocity of the system when the motor is not in operation. the 1d finite element analysis shows that there are two modes which are close to the design frequency of 300 hz i.e. mode 1 and 2. however the critical rotational velocity in both modes are still far above the maximum velocity design of 6,000 rpm. validation using 3d finite element analysis demonstrated that all modes were still above the designed frequency and did not find any critical speed below 6,000 rpm. it can be concluded that the critical speed of the rotor of ipm motor is still outside the system resonance region, and can be operated safely. keywords: natural frequency, campbell diagram, interior permanent magnet motor, finite element method. i. introduction interior permanent magnet (ipm) motor is one of electric motor type, which is widely applied in the compact system for its several advantages: lightweight, small size, simple mechanical construction, easy maintenance, high reliability as well as high energy to volume ratio [1-5]. one of the problems in designing the rotating machinery including ipm motors is the vibration, because the vibration is usually a direct cause of the component damage. every spinning rotor has some vibration, at least a once-per-revolution frequency component (1st order) therefore it is impossible to make any rotor perfectly mass balanced. rotor-dynamic analysis is essential for quantifying safe upper limits of allowable vibration levels by analyzing the critical speed of the system which is very useful. it can provide information about the resonance region of the system and can be used as a standard to monitor the possibility of harmful, due to damage of the components. in addition, it is very useful for designers in understanding the relationship between the selection of design schemes including the shaft size, bearing properties, housing stiffness and machine stability [6]. there are two methods which are often adopted to deal with rotor dynamic problem. one is the transfer matrix method, such as riccati transfer matrix method and the other is the finite element method (fem), which has higher numerical stability but need more storage space of the computer. both methods are widely used to solve the rotor dynamic problem. the former method divides the system into several parts after it gets the lumped mass model, such as the disk, the shaft and the bearing. then it establishes the relation of the state vectors between the both ends of the cross-section and use the continuity conditions to obtain the relation between the state vectors in any cross section and the initial one. the latter method, namely fem, was not adopted to analyze rotor dynamic problem until 1970s.the key idea of the fem is to transform the infinite dof (degrees of freedom) problem into a finite number of dof, and then solve it. as the computer technology develops, the fem become very popular to analyze mechanical problems, not just the rotor dynamic [7]. *corresponding author. tel.: +62-81394297528 e-mail: alam_hilman@yahoo.com http://dx.doi.org/10.14203/j.mev.2014.v5.1-8 h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 2 the fem has several advantages such as reduction of time when solving complex equation system. in addition, it can be applied by the software and can be widely applied in solving problems in engineering field for high accuracy and flexibility [8]. some previous research have been used finite element to evaluate the dynamic characteristics of the rotor shaft system for some applications, such as: main shaft system in a hydro-turbine [7], gas turbine rotor [8], rotating structures [9], rotor-shaft system for evaluating hydro-dynamic action in journal bearings [10], and induction motors [11], and the rotor deflection of permanent magnet (pm) generator [12]. in this study, the dynamic characteristic of the rotor is evaluated using finite element method, in order to determine the existence of a critical speed and safe upper limits of allowable vibration levels of ipm motors, so it can be used as a reference for dynamic analysis and a foundation for the design or improvement. ii. materials and methods the dynamic characteristic of the rotor was evaluated using finite element method by analyzing the critical speed based on the campbell diagram which represents the relationship between the natural frequencies and the rotational velocity of the system. 1d finite element analysis is conducted numerically based on the development of the lagrange equations and the effects of unbalanced mass and bearing influence are neglected. then, the results of analysis are validated using ansys, a commercially software based on three 3d finite element analysis. the main components of rotor are the shaft, bearing and permanent magnet along with the crank which is modeled simply as a disk, shown in figure 1. to determine the dynamic characteristics of the rotor, the calculation of the kinetic energy is required to characterize disk, shaft and unbalanced mass. in addition, the strain energy is employed to characterize the shaft. force on the bearing as the action force on the shaft is used to calculate the virtual work due to an external force. the general equation to evaluate the dynamic characteristics of the rotor can be modeled using lagrange equation as follows [15]: ( ) (1) where ( ) is the number degree of freedom, are generalized independent coordinates, are generalized forces, and denotes differentiation with respect to time . a. 1d finite element in 1d finite element, shaft is modeled as a beam which has a constant circular cross-section. if the element has two nodal, it will form the 8order matrix. each of the nodal has 4 degrees of freedom: 2 displacements and 2 slopes in both xy plane and y-z planes (figure 2), therefore nodal displacement vector can be written in the equation [15]: [ ] (2) the relationship between displacement and slope are: (3) (4) displacements and in accordance with movements in the x and z directions written by the equation: [ ] (5) [ ] (6) displacements in the finite element are formed from: ( ) (7) ( ) (8) ( ) and ( ) are the function of displacements for the beam that are subjected to bending loads: figure 1. rotor components of ipm motors figure 2. modeling of one dimensional (1d) rotor [15] h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 3 ( ) * + (9) ( ) * + (10) kinetic energy of the shaft can be calculated as: ∫ [ ̇ ̇ ̇ ̇] ∫ [ ̇ ̇ ̇ ̇] ∫ ̇ (11) where is the mass per unit volume, is the cross sectional area of the beam, and is the area moment of inertia of the beam cross section about the neutral axis, is the length of element and is the angular velocity. substitution of equation (9) and (10) into equation (11), then: ̇ ̇ ̇ ̇ ̇ ̇ ̇ ̇ ̇ (12) and are the classical mass matrix, and are generated due to a secondary effect of rotor inertia, and is generated due to gyroscopic. by applying the lagrange equation, then: ( ̇ ) ( ) ̈ ̇ (13) where and are obtained from and from , thus: [ ] (14) [ ] (15) [ ] (16) strain energy on the shaft can be calculated by the equation: ∫[ ] ∫ * + (17) then, after integration: (18) h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 4 where and are the classical stiffness matrix ( ), and are the matrix due to the axial force ( ). the effect of shear force can be calculated by the equation: (19) with shear modulus: ( ) (20) where is the poissons ratio and e is young’s modulus of the material. then by applying eq. (17) to the lagrange equation: (21) (22) where dan , can be calculated ( ) [ ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ] (23) [ ( ] (24) furthermore the equations for the components of permanent magnet and the hollow crank are modeled as a disk, which only characterized by its kinetic energy. the node of the rotor has four degrees of freedom: two displacements and and two slopes about the x-y and y-z planes, which are and respectively. then if the nodal displacement vector δ of center of the disk is [ ] (25) by applying the lagrange equations, the equation for the disk: ( ̇ ) [ ][ ̈ ̈ ̈ ̈ ] [ ] [ ̇ ̇ ̇ ̇ ] (26) where the first matrix is the classical stiffness matrix and the second one is the matrix due to gyroscopic effects. in this study, the effects of unbalanced mass and bearing influence are neglected so that the general equation of rotor dynamics is ̈ ( ) (27) where is all nodal displacement vectors, is the mass matrix, is the stiffness matrix and ( )is the force vector. 1d finite element analysis in this study uses the discretization of 4 elements and 5 nodal. simplification scheme of the rotor with dimension in mm is shown in figure 3. to produce the equality throughout the element, the local element matrix of each element is arranged into a global matrix. every element, which has the same number of nodal and that of degrees of freedom, is placed on the same row and column and this applies to the mass matrix, stiffness matrix and damping matrix [14]. the h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 5 illustrative example of the element assembly from local elements into global element for two local elements can be seen in figure 4. globalizing matrix in this way is the fastest and easy, even for a lot of elements and nodal degrees of freedom. in addition to the dimensions of each component of the rotor, the mechanical properties of the component are also required as the input data of the calculation. in this study, the material of the shaft is jis s45c steel, with poissons ratio = 0.27 to 0.30, tensile strength = 569 mpa, yield strength = 343mpa, young's modulus, e = 190 to 210 gpa and density = 7,700 to 8,030 kg/m 3 [16]. meanwhile, the disk consists of two components, namely the crank is made of steelst37 and the permanent magnet type is ndfeb. both the density of the material is almost the same which is about 8,000 kg/m 3 . b. 3d finite element the evaluation procedures of 3d finite element analysis using ansys to analyze rotordynamic characteristics consist of geometric modeling, material definition, meshing (discretization), the determination of boundary conditions, calculation, and displaying the results [6][7]. in the geometry modeling stage, the geometry of every rotor component is made in 3d and its material type is defined from specification. meshing stage is conducted by dividing the components into small elements with a finite number and then doing analysis according to the material properties, boundary conditions and loading. in this study, the tetrahedral 3d element type on auto-mode is used, meaning that the discretization step is performed automatically by ansys program, including the selection of the elements number. after the processes of iteration and calculation are solved, then the final stage is to display the results of the simulation. iii. results and discussion a. 1d finite element campbell diagram showing the output results of numerical simulations using the finite element method represents a natural frequency as a function of rotational speed. figure 5 shows the dynamic characteristics of the rotor using 1d finite element that are visualized by campbell diagram, where the x axis is the rotation in rpm and the y axis is the natural frequency of the system. the black solid line indicates the frequency of the rotor which equals to the frequency of rotation, while the black dashed line indicates the frequency of the rotor which equals half of the frequency of the rotation. figure 4. element assembly from local elements into global element for two elements [15][16] figure 5.campbell diagram of 1d finite element analysis 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 0 500 1000 1500 2000 2500 3000 n (rpm) f ( h z ) campbell diagram f=n/60 f=0.5n/60 mode 1 bw mode 1 fw mode 2 bw mode 2 fw mode 3 bw mode 3 fw mode 4 bw mode 4 fw figure 3. simplification scheme of the discretization in 1d finite element analysis for the rotor h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 6 the simulation results illustrate only the first four modes in the diagram because the value of the other modes is far above the operating speed of the motor. each mode has two lines of response in the opposite direction those are fw (solid line) and bw (dashed line). when the response lines equal to the rotational speed or showing intersections in the diagram then these intersections are called critical speed. the maximum speed of the ipm motor refers to the maximum frequency of the speed control used that is 300 hz. having 6 poles number, the maximum speed of the motor equals to 120 multiplied by the frequency and divided by the number of poles yields 6,000 rpm. according to the simulation results, the possibilities of rotor critical speeds are in mode 1 and 2, therefore the analysis is focused on both frequencies. by enlarging the campbell diagram near the maximum design frequency of 300hz, modes 1 and 2 are investigated as shown in figure 6.as shown on figure 6, there is intersecting point between the response line and mode 1 at the rotational speed of 7,000 rpm (116.4 hz). however, that critical speed resulted from the 1d finite element analysis is above the motor maximum speed of 6,000 rpm and frequency of 300 hz so that the motor can operate safely. these results are then compared with the results obtained from 3d finite element analysis. b. 3d finite element discretization or meshing in ansys uses tetrahedral 3d element in auto mode. the meshing process produces 18,077 elements and 37,571 nodal, shown in figure 7. if we compared with 1d finite element, that has very few elements and nodal, 3d finite element will generate a more detailed analysis on each segment of the rotor. after iteration and calculation process are solved by the computer, campbell diagram and each natural frequency modes will be generated from the results of calculations. in this study, the first ten modes are examined and represented in table 1. from the 10 modes generated by 3d finite element, the smallest natural frequency is well above the design frequency of 300 hz. campbell diagram in figure 8 shows that all modes do not indicate critical speeds in the system for the rotational velocity 1,000 rad/s or 9,554.14 rpm. based on these results, the ipm motor designed with the maximum speed of 6,000 rpm and the frequency of 300 hz can be operated safely. the other simulation result is the modal map in different modes. the modal maps of the first six modes are shown in figure 9. the first and the second modes appear to be bending on the disk to the shaft position, while the third and fourth modes there is a shift toward the disk position to the shaft axis. then at the fifth and sixth modes, bending occurs on the shaft. iv. conclusion rotor-dynamic characteristics of the ipm motor in the form of the critical speed in the campbell diagram has been evaluated using the 1d and 3d finite element method. 1d finite figure 6. rotor critical speeds in mode 1 and 2 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 0 50 100 150 200 250 300 350 400 450 500 n (rpm) f ( h z ) campbell diagram f=n/60 f=0.5n/60 mode 1 bw mode 1 fw mode 2 bw mode 2 fw figure 7. discretization using tetrahedral elements table 1. frequencies at the first ten modes mode frequency (hz) 1 505.08 2 552.16 3 655.71 4 992.08 5 1,084.80 6 1,087.40 8 3,288.90 9 3,684.30 10 3,711.70 h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 7 figure 8. campbell diagram of 3d finite element analysis figure 9. the model maps of the first six modes h. s. alam and p. irasari / mechatronics, electrical power, and vehicular technology 05 (2014) 1-8 8 element analysis yields two modes (modes 1 and 2) which are in the range of frequency design of 300 hz, however the critical rotational velocity in both modes are still far above the maximum velocity design of 6,000 rpm. validation using 3d finite element analysis demonstrates that all modes are still above of the designed frequency and did not find any critical speeds below 6,000 rpm. it can be concluded that the critical speed of the rotor of ipm motor is still outside the system resonance region and could be operated safely. acknowledgement authors would like to thank to kegiatan kompetitif lipi 2013, which has funded this research. moreover thanks to all the team members of electric machines in the research centre for electrical power and mechatronics, for any assistance that has been given. references [1] c. y. young, et al.,“research on the output characteristics of ipmsm according to the pole-slot combinations,” energy precedia, vol. 14, pp. 1187-1192, 2012. [2] h. m. hasanien, “torque ripple minimization of permanent magnet synchronous motor using digital observer controller,” energy conversion and management, vol. 51, pp. 98-104, 2010. [3] c.c. hwang, et al., “comparison of performances between ipm and spm motors with rotor eccentricity,” journal of magnetism and magnetic materials, vol. 282, pp. 360-363, 2004. [4] j. d. ede, et al., “rotor resonances of highspeed permanent-magnet brushless machines,” ieee transactions on industry applications, vol. 38, no. 6, pp. 1542-1548, 2002. [5] s. i. kim, et al., “optimization for reduction of torque ripple in interior permanent magnet motor by using the taguchi method,” ieee transactions on magnetics, vol. 41, no. 5, pp. 1796-1799, 2005. [6] f. trebuňa1, et al., “numerically computed dynamics rotor using ansys software,” the 4 th international conference: modelling of mechanical and mechatronic systems, herľany, slovak republic, pp. 498-501, 2011. [7] b. bai, et al.,”analysis of dynamic characteristics of the main shaft system in a hydro-turbine based on ansys,” procedia engineering, vol. 31, pp. 654-658, 2012. [8] h. taplak and m. parlak, “evaluation of gas turbine rotor dynamic analysis using the finite element method,” measurement, vol. 45, pp. 1089-1097, 2012. [9] i. bucher and d. j. ewin, “modal analysis and testing of rotating structures,” philosophical transactions the royal society london, vol. 359, pp. 61-96, 2001. [10] m. chouksey, et al., “modal analysis of rotor-shaft system under the influence of rotor-shaft material damping and fluid film forces,” mechanism and machine theory, vol. 48, pp. 81-93, 2012. [11] p. paolaor, et al., “studies of mechanical vibrations and current harmonics in induction motors using finite element method,” wseas transactions on systems, issue 3, vol. 7, pp. 195-202, 2008. [12] hilman s. alam, et al., “analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator,” mechatronics, electrical power, and vehicular technology, vol. 03, pp. 8794, doi: 10.14203/j.mev.2012.v3.87-94, 2012. [13] hutton, d. v., fundamental of finite element analysis, usa: the mcgraw hill company, 2004, pp. 1-50. [14] rao s. s., “the finite element method in engineering 4th edition,” elsevier science, 2004. [15] m. lalanne, g. ferraris, rotor dynamics prediction in engineering, 2nd edition, united kingdom: john wiley and sons ltd, 1998, pp. 1-248. [16] t. admono, (2003), “pembuatan program simulasi prediksi prilaku dinamik sistem mono rotor menggunakan matlab,” pusat penelitian informatika lipi,. [online]. available: http://digilib.informatika.lipi.go.id/informati ka/mybox/290tri_admono_pembuatan_progr am_simulasi_monorotor.pdf. [17] jis s45c mild steel an overview, mead info, 2010. [online]. available: http://www.meadinfo.org/2010/03/s45c-jismechanical-properties.htm http://digilib.informatika.lipi.go.id/informatika/mybox/290tri_admono_pembuatan_program_simulasi_monorotor.pdf http://digilib.informatika.lipi.go.id/informatika/mybox/290tri_admono_pembuatan_program_simulasi_monorotor.pdf http://digilib.informatika.lipi.go.id/informatika/mybox/290tri_admono_pembuatan_program_simulasi_monorotor.pdf mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.99-108 object recognition system in remote controlled weapon station using sift and surf methods midriem mirdanies a, ary setijadi prihatmanto b, estiko rijanto a a research center for electrical power and mechatronics, indonesian institute of sciences (lipi) komp lipi bandung, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia b school of electrical engineering and informatics, bandung institute of technology (itb) jl. ganesha no 10, bandung 40132, indonesia received 8 april 2013; received in revised form 12 november 2013; accepted 13 november 2013 published online 24 december 2013 abstract object recognition system using computer vision that is implemented on remote controlled weapon station (rcws) is discussed. this system will make it easier to identify and shoot targeted object automatically. algorithm was created to recognize real time multiple objects using two methods i.e. scale invariant feature transform (sift) and speeded up robust features (surf) combined with k-nearest neighbors (knn) and random sample consensus (ransac) for verification. the algorithm is designed to improve object detection to be more robust and to minimize the processing time required. objects are registered on the system consisting of the armored personnel carrier, tanks, bus, sedan, big foot, and police jeep. in addition, object selection can use mouse to shoot another object that has not been registered on the system. kinect™ is used to capture rgb images and to find the coordinates x, y, and z of the object. the programming language used is c with visual studio ide 2010 and opencv libraries. object recognition program is divided into three parts: 1) reading image from kinect™ and simulation results, 2) object recognition process, and 3) transfer of the object data to the ballistic computer. communication between programs is performed using shared memory. the detected object data is sent to the ballistic computer via local area network (lan) using winsock for ballistic calculation, and then the motor control system moves the direction of the weapon model to the desired object. the experimental results show that the sift method is more suitable because more accurate and faster than surf with the average processing t ime to detect one object is 430.2 ms, two object is 618.4 ms, three objects is 682.4 ms, and four objects is 756.2 ms. object recognition program is able to recognize multi-objects and the data of the identified object can be processed by the ballistic computer in realtime. keywords: rcws, object recognition, shared memory, sift, surf, opencv, c language, kinect™. i. introduction defense system of a country requires reliable weapon systems [1], one of them is remote controlled weapon station (rcws). rcws is commonly used in modern combat equipment such as tank or armoured personnel carrier (apc). rcws is a weapons system that can be operated remotely from vehicle cabin so the gunner is protected savely. this paper describes the results of the computer vision research which is implemented on rcws. this system will make it easier to recognize and to shoot targeted objects automatically, including to shoot multiple objects. kinect™ is used to capture rgb images and the object coordinates x, y, and z in meters [2] which can be seen in figure 1. kinect™ consists of infrared cameras, rgb camera, infrared laser projector, microphone, and tilt motors. the research was performed at the mechatronics lab. research center for electrical power and mechatronics (indonesian institute of sciences), and the school of electrical engineering and informatics lab. bandung institute of technology (itb). rcws model tested to move the weapon model in the laboratory. the weapon model can be seen in * corresponding author. phone: +62-22-2503055 e-mail: midriem.mirdanies@lipi.go.id http://dx.doi.org/10.14203/j.mev.2013.v4.99-108 m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 100 figure 2. kinect™ is placed in the front side and separated from the weapon model. methods that can be used in tracking and object recognition have been reported by yilmaz [3]. methods to recognize objects can be based on color [4], shape, or other. methods used in this research is scale invariant feature transform (sift) [5], [6] and speeded up robust features (surf) [7] combined with the k-nearest neighbors (knn) and random sample consensus (ransac) for verification. the programming language used is c with visual studio ide 2010 and open cv libraries [8], [9], [10]. experiment was done to compare the accuracy and process speed of the both methods. an algorithm is developed to detect multiple objects simultaneously, while improving object detection results to be more robust and to minimize the time required for the object recognition. the recognized objects are sent to the ballistic computer through local area network (lan) using winsock [11] for further processing. object recognition program is divided into three section: capturing images from kinect™ and simulation results, object recognition process, and object data transfer to the ballistic computer. communication between programs was performed using shared memory. with shared memory, data on the memory can be accessed by multiple programs [12]. concept used in sift and surf method is to find interest points, also called keypoint or feature points. the idea is to find the unique features in the images and perform analysis on that feature. the advantage of using sift and surf methods than some other methods is scale invariant, i.e. the object that had been detected may have different scale than the comparison object. it also supports object rotation and can detect objects even if partially visible. there are four major stages in the sift method to generate the set of image features: scale-space extrema detection, keypoint localization, orientation assignment, and calculating keypoint descriptor [13]. after doing these stages, features will be obtained which is used as a descriptor of an object to be processed further. in the process, sift uses laplacian filter. laplacian filter in difference scale is calculated based on gaussian filter. the stages of surf almost the same as sift, but it uses hessian determinant filter, not the laplacian filter. the main difference between the surf and the sift is the speed and accuracy, typically surf gives faster process, whereas sift is more accurate in finding its matching feature [14]. ii. remote controlled weapon station design figure 3 shows the rcws design conducted in this research. there are three main parts on the rcws system, i.e. computer vision, ballistic figure 1. kinect™ sensor used in this research color sensor ir emitter ir depth sensor tilt motor microphone array figure 3. rcws design figure 2. weapon model m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 101 computer, and motor control. the dotted lines in figure 3 are area of this research. there are two computers used, the first computer is for computer vision, and the other is for ballistic computer and motor control. communication between both computers is done via lan. image from kinect is processed by the first computer to recognize object. objects coordinate that are detected will be sent to the second computer to do ballistic calculation. ballistic calculation is performed by several parameters, i.e. the object coordinates, projectile, and other data from the temperature sensor, wind velocity and wind direction in order to obtain the correction of shooting angle (azimuth and elevation), then the motor control system will give the command to the motor driver to move the weapon model in order to direct towards a selected object. iii. computer vision design two computer programs have been created. the first is used to store data in a database (training data) that can be seen in figure 4. the second is realtime object recognition process that can be seen in figure 6 and figure 7. the database file was created with ".yml" extension and it is saved separately for each object and method. it is intended to be efficient, so only the required files are used. this would avoid the buildup of data in a single file. the process storage of objects data to the database is done by selecting the desired object using mouse figure 5. objects stored in the database figure 4. object data storage process in the database m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 102 so it is user friendly. objects used consist of toys apc, tank, bus, sedan, big foot, and police jeep. figure 5 shows the objects, while the database file object is listed in table 1. object was trained from several sides. each file contains object name, images, key point, and the object descriptor. all data is stored in the database so there is no need to look for key point and descriptor again during the process of object recognition. this method will speed up the program execution. figure 6 shows real time objects identification flowchart. in the initial phase, all databases are loaded into memory, to speed up the execution time. the experiment result shows that the speed of the object identification process is faster than if it is made directly to the database. the next step is to compare all the data in the database that has been loaded into memory with the image data from kinect™ to find a match object. this process is based on an algorithm created by robert lagainere [14]. the experimental results show that the objects identification becomes more robust. however, this study has done some modifications, such as addition of data checking i.e. keypoint checking before matching process, symmatches before ransactest, outmatches before the conversion of keypoint to point process, and point before the findfundamentalmat. the experimental result shows that realtime process will generate error if the data input does not exist or insufficient extent. the algorithm was also modified to be able to choose the method used (sift or surf method) by changing the parameter setjenisfeature. in addition, the searching process of the keypoint and descriptor for each compared image table 1. object database file no file name object method the amount of data object name images keypoints descriptors 1 sift_bus.yml bus sift 1 36 36 36 2 surf_bus.yml bus surf 1 36 36 36 3 sift_mobil_sedan.yml sedan sift 1 36 36 36 4 surf_mobil_sedan.yml sedan surf 1 36 36 36 5 sift_tank.yml tank sift 1 38 38 38 6 surf_tank.yml tank surf 1 38 38 38 7 sift_panser.yml apc sift 1 38 38 38 8 surf_ panser.yml apc surf 1 38 38 38 9 sift_big_foot.yml big foot sift 1 48 48 48 10 surf_big_foot.yml big foot surf 1 48 48 48 11 sift_jeep_polisi.yml police jeep sift 1 49 49 49 12 surf_jeep_polisi.yml police jeep surf 1 49 49 49 figure 6. real time object recognition flowchart m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 103 is not performed continuously, but only as needed, i.e. the image from the kinect™ is done only at the beginning when image from kinect™ will be compared with the database and if there is a marking of detected objects for every image. as a result, it is not necessary for the image to search a key point and descriptor again, because it’s already stored in the database. this way will speed up the program execution process. section of finding objects and sending data objects to ballistic computer in figure 6 consists of matching process, calculating homography, finding object coordinate and sending to ballistic computer. detail process of finding objects and sending data objects to ballistic computer can be seen in figure 7. realtime object recognition program is divided into three parts and interact each other using shared memory as shown in figure 8. three parts of data are shared between programs: captured image from kinect™, object identified object data (name and center of the object), and a complete objects data (name and coordinate x, y, z in meter). handle file mappings used for each data are “global\\matmappingobject”, “global\\objekmappingobject”, and “global\\dtlngkpmappingobject”. figure 9 shows the flowchart of the delivery of the detected object data to the ballistic computer flowchart, figure 10 shows the object recognition flowchart, and figure 11 shows flowchart of the real time images captures from kinect™ and the detected object display to the screen for simulation. figure 7. find objects and send object data to ballistic computer figure 8. distribution of object identification programs with shared memory mechanism figure 9. distribution of object identification programs with shared memory mechanism m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 104 iv. result and discussion the computer used in this experiment is a laptop with the following specifications: processors intel® core™ i5-2450m cpu @ 2.50 ghz, 8 gb ram, microsoft windows 7 64 bit, and nvidia geforce 410m, which can be seen in figure 12. a. object recognition algorithm figure 13 is an experiment result displaying the detection of an apc. name and coordinates x, y, and z of the detected object is displayed on the screen and command prompt. the program execution time is displayed in the command prompt. figure 10. object recognition flowchart figure 11. flowchart of the image capturing process from kinect™ and simulation results figure 12. laptops used in experiments m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 105 experiments were performed to detect a tank and apc objects in the lab, ten times for each object from several positions. experiments to test speed of the three methods were done by calculating the process time for every iteration from the key point calculation from kinect™ to the completion of comparisons between the data and the database. table 2 lists experiment results concerning accuracy and processing time of the three methods. from table 2 can be seen that the sift method provides better accuracy and faster processing time. the sift method can detect 13 times in 20 experiments (65%), with an average processing time of 1519.2 ms. the surf method can detect 8 times (50%), with an average processing time of 2667.4 ms. based on experiments it can be seen that the less feature point (uniqueness) in an image and the ruination of lighting, the smaller the possibility of the object can be detected. it was also found that the process time of the sift method being faster than the surf method figure 13. experiment to detect apc table 2. experiment results concerning accuracy and processing time using sift and surf methods no object name detection process time (ms) sift surf sift surf 1 panser √ √ 1,511 2,329 2 panser √ √ 1,489 2,505 3 panser √ 1,526 4 panser √ √ 1,519 2,634 5 panser √ √ 1,508 2,554 6 panser 7 panser 8 panser √ 1,482 9 panser √ 1,521 10 panser √ 1,583 11 tank √ √ 1,511 2,876 12 tank 13 tank 14 tank √ √ 1,531 2,825 15 tank √ √ 1,541 2,829 16 tank √ √ 1,525 2,787 17 tank 18 tank 19 tank 20 tank √ 1,502 figure 14. the number of keypoints using sift and surf methods 0 200 400 600 800 1000 1200 1400 0 5 10 15 20 t h e n u m b e r o f k e y p o in ts experiments sift surf m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 106 because the number of key point in the sift method is less than the surf method. figure 14 shows the comparison of number of key point using sift and surf method. twenty times of the experiments results show that the average number of sift key point is 274.1, while surf is 1008.9. b. shared memory figure 15 shows experiment result of the communication between the three programs using shared memory. in figure 15 it can be seen that the three programs can communicate each other using shared memory. it can be seen from the data congruence displayed on the command prompt of each program with the data display on the screen. experiments to see a comparison of the process time before and after the program being divided into three parts using the sift method can be seen in table 3. the object recognition process was calculated since the image from kinect™ was loaded from the shared memory until the whole process of comparisons between the data from kinect™ and the database is complete. the experiments results proved that figure 15. communication experiment using shared memory mechanism (a) (b) figure 16. data transmission experiments via lan; (a) computer vision; (b) balistic computer and motor control m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 107 object recognition process become faster than before, with an average processing time is 430.2 ms. experiment to see object recognition time in the case of two to four objects at a time can be seen in table 4. table 4 indicates that the average time required to detect two objects is 618.4 ms, three objects is 682.4 ms and four objects is 756.2 ms. figure 16 shows flow of data sent from computer vision to ballistic computer or servo motor control system. in figure 16 it can be seen that data from the computer vision was received correctly by the ballistic computer that is panser: -0.396863; -0.0530291 = 0.985. experiments to examine the performance of rcws in the case of moving weapon model towards a selected object can be seen in figure 17. experiments results show that the weapon model can move towards a selected object, which is proven by the laser pointer direction that leads to the object. v. conclusions object recognition using sift and surf methods have been successfully implemented on rcws. the object recognition algorithms can detect multiple objects simultaneously. experiments results show that the sift method gives better performance than the surf method. process time can be minimized by optimizing the algorithm, and dividing the program into three figure 17. rcws experiments in the case of moving weapon model table 3. experiments to see object recognition process time after program was divided into three parts no object detected (using sift method) processing time (ms) 1 panser √ 418 2 panser √ 407 3 panser √ 430 4 panser √ 405 5 panser √ 409 6 panser 7 panser 8 panser √ 387 9 panser √ 409 10 panser √ 468 11 tank √ 453 12 tank 13 tank 14 tank √ 461 15 tank √ 481 16 tank √ 461 17 tank 18 tank 19 tank 20 tank √ 404 table 4. experiments to see object recognition process time to detect two to four objects at once no object number processing time (ms) 1 2 637 2 2 619 3 2 634 4 2 605 5 2 597 6 3 677 7 3 688 8 3 683 9 3 701 10 3 663 11 4 748 12 4 755 13 4 759 14 4 765 15 4 754 m. mirdanies et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 99-108 108 parts, each part runs independently and communicates with each other using shared memory. the average processing time to detect an object is 430.2 ms, two object is 618.4 ms, three objects is 682.4 ms, and four objects is 756.2 ms. the data of the identified object can be processed by the ballistic computer in realtime manner and the weapon model can move towards the desired object. further research may be done by increasing training data number for each object to obtain more robust object recognition. acknowledgement authors would like to thank to the research center for electrical power and mechatronics indonesian institute of sciences, school of electrical engineering and informatics bandung institute of technology, and the ministry of research and technology for the opportunity and financial support, also to iwan muhammad erwin, adi yasri bahri, riyo wardoyo, and all those who have helped conducting this research. references [1] m. mirdanies, et al., kajian kebijakan alutsista pertahanan dan keamanan republik indonesia. jakarta: lipi press, 2013. [2] n. v. bagwe, "a study of the microsoft’s kinect camera," indian institute of technology, bombay2012. [3] a. yilmaz, et al., "object tracking: a survey," acm computing surveys, vol. 38, no. 4, 2006. [4] a. djajadi, et al., "a model vision of sorting system application using robotic manipulator," telkomnika, vol. 8, no. 2, pp. 137-148, 2010. [5] d. l. g, "object recognition from local scale-invariant features," in international conference on computer vision, corfu, 1999. [6] g. bradski and a. kaehler, "learning opencv," m. loukides, ed., ed. sebastopol: o’reilly media, inc., 2008. [7] h. bay, et al., "surf: speeded up robust features," computer vision eccv, vol. 3951, pp. 404-417, 2006. [8] i. corp., "the opencv reference manual (release 2.4.2)," ed, 2012. [9] i. corp., "the opencv tutorials (release 2.4.2)," ed, 2012. [10] i. corp., "the open cv user guide," ed, 2012. [11] microsoft. using winsock (windows) [online]. available: http://msdn.microsoft.com/enus/library/windows/desktop/ms740632%28v =vs.85%29.aspx [12] microsoft. creating named shared memory [online]. available: http://msdn.microsoft.com/enus/library/windows/desktop/aa366551%28v =vs.85%29.aspx [13] d. g. lowe, "distinctive image features from scale-invariant keypoints," international journal of computer vision, vol. 60, no. 2, pp. 91-110, 2004. [14] r. laganiere, opencv 2 computer vision application programming cookbook. birmingham: packt publishing, 2011. 10.14203/j.mev.2013.v4.99-108 kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 65-72, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.65-72 solar-based fuzzy intelligent water sprinkle system sistem kecerdasan fuzzy untuk penyiram tanaman menggunakan tenaga surya riza muhida1, momoh jimoh e. salami2, winda astuti2, nurul amalina bt ahmad kasim2, nani rahayu2 1stkip surya, surya research and education center scientia garden, gading serpong, tangerang, banten 15810, indonesia 2department of mechatronics engineering, faculty of engineering international islamic university malaysia jalan gombak, 53100 kuala lumpur, malaysia muhida@gmail.com recieved: may 9th, 2011; revised: may 27th, 2011; accepted: november 24th, 2011; published online: december 22th, 2011. abstrak sistem kecerdasan fuzzy untuk penyiram tanaman menggunakan tenaga surya sudah dikembangkan untuk meningkatkan keefektifan penyiraman tanaman yaitu dengan membuat sistem ini bekerja secara otomatis. sistem pengendali terdiri dari suatu sensor kelembaban tanah yang bekerja menggunakan prinsip kapasitansi listrik, yang ditanamkan di dalam tanah. sensor ini kemudian dihubungkan dengan antarmuka dengan unit pengontrol motorola 68hc11. pemograman mikrokontroler berdasarkan aturan pengambilan keputusan melalui pendekatan logika fuzzy. sistem secara keseluruhan menggunakan tenaga dari energi surya. sistem ini dihubungkan kepada suatu jenis pewaktu irigasi untuk penjadwalan pemupukan tanaman dan detektor hujan mengunakan pengumpul hujan jenis ember kembar. unit pengendali untuk membuka katup pengendali irigasi ditempatkan dalam satu garis antara sensor kelembaban tanah dan dua jenis divais lainnya yaitu pewaktu irigasi dan pendeteksi hujan. unit pengendali ini secara otomatis mengirimkan sinyal stop kepada katup pengendali ketika kondisi rumput basah dan tidak memerlukan irigasi. menggunakan sistem ini, kami mengkombinasikan penerapan logika di dalam area irigasi dan peralatan sensor cuaca, dan membuat pendistribusian air mejadi lebih efisisen. kata kunci: surya, penyiram tanaman, fuzzy, mikrokontroler. abstract a solar-based intelligent water sprinkler system project that has been developed to ensure the effectiveness in watering the plant is improved by making the system automated. the control system consists of an electricalcapacitance soil moisture sensor installed into the ground which is interfaced to a controller unit of motorola 68hc11 handy board microcontroller. the microcontroller was programmed based on the decision rules made using fuzzy logic approach on when to water the lawn. the whole system is powered up by the solar energy which is then interfaced to a particular type of irrigation timer for plant fertilizing schedule and rain detector through a simple design of rain dual-collector tipping bucket. the controller unit automatically disrupted voltage signals sent to the control valves whenever irrigation was not needed. using this system we combined the logic implementation in the area of irrigation and weather sensing equipment, and more efficient water delivery can be made possible. keywords: solar, water sprinkler, fuzzy, microcontroller. i. introduction the primary reason for watering is to provide water to plant when the frequency and amount of rainfall is insufficient to replenish water used by the plant system. sprinkler watering system is a method of applying water similar to rainfall. however, the extreme use of water will result in ill water distribution and landscapes overirrigating which cause one-third of urban water to be wasted [1]. keeping these facts in mind, we decided to tackle part of the problem by trying to improve the water efficiency in irrigation systems by proposing an intelligent water sprinkler that can be operated automatically based on the moisture level of the soil using soil moisture sensor placed in the soil. a microcontroller activates a valve when signal from the sensor indicates the moisture level of the soil is low or not enough. based on that, water is distributed through a pipe to be sprayed into the air covering entire soil surface through spray heads so that it breaks up into water drops and fall to the ground. http://dx.doi.org/10.14203/j.mev.2011.v2.65-72 solar-based fuzzy intelligent water sprinkle system (riza muhida, m.j.e. salami, w. astuti, n. amalina, n. rahayu) jmev 02 (2011) 65-72 66 this solar-based intelligent water sprinkler system is not like other ordinary water sprinkler. the conventional watering system is operated manually and using common electrical power supply source. this water sprinkler is a solarbased intelligent water sprinkler, which is designed to operate automatically, manages water correctly based on the type of soil and keeps the plant healthy by watering the plant at the right time and also not over waterring the plant. this water sprinkler system is a closed loop system. figure 1 shows the block diagram of the solar-based intelligent water sprinkler system. the soil moisture sensor senses condition of moisture in the soil for the grass or plant [1-18]. then the signal or information from the sensor will be sent to microcontroller (m68hc11) which acts as the brain of the whole system. in order to create the ability of the intelligent system to automate the irrigation process, fuzzy logic system approach is implemented for the brain of the controller. the output signal from the sensor is in the form of voltage. beside the information about soil moisture, the microcontroller will also check weather condition and fertilizing needs of the plants. then the controller decides the next operation or task, wether to activate the valve and sprinkler or not. another advantage of this system is that alternative power used as a power supply for the system is photovoltaic. the power from the pv system is needed to power up the microcontroller, sensors and valve. the solar system is chosen for the system because its energy from the sun is not only free but also environmentally friendly to the system and accomplishes the task of keeping healthy growth of plant. the main objective of this research is to design and develop a solarbased intelligent water sprinkler system that is capable of monitoring and adjusting its environment accordingly by using soil moisture sensor and powered by solar power supply. ii. methodology refer to figure 1, the major parts of this program are the soil moisture sensor, controller system design, solar power supply, and sprinkler construction. the main components from the diagram are the controller which consists of analog to digital and digital to analog conversions, the feedback from the soil moisture sensor, rain detector and digital timer with the outputs to activate the valves for both water supply and fertilizing apparatus. the controller is powered by solar energy which converts the energy into electricity from the photovoltaic cells as the substitute to the direct power supply. the operation of the system is based on the interruption of the voltage differences and resistance changes from the soil moisture sensor. when these occur, the system will execute the decision made and apply according to the rules at appropriate time. from the block diagram, the first analog response from the soil moisture sensor is transferred to the controller once the sensor detects an interruption signal or voltage drop. due to this interrupt signal, the controller then started to execute its program which is developed based on the fuzzy logic approach in order to automate the system by activating the valve and turn on the sprinkler based on the rules applied. the rules developed are based on the weather condition using rain detector in order to indicate the existence of rainfall and digital timer to set the fertilizing time for the plant. the process will go on continuously until the soil moisture sensor sends another signal indicating that there is adequate amount of water in the soil to interrupt the program. figure 1. block diagram of solar-based intelligent water sprinkler. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 65-72, 2011 p-issn 2087-3379 67 in this project, a fuzzy logic approach is implemented by applying set of rules which can operate the system based on weather condition and the needs of fertilization. figure 2 shows the mechanism of this water sprinkler. from the starting point, first, the system detected whether all the sensors are in active condition. then, in the next routine, we measure the soil condition using soil moisture sensor. when there are sufficient amount of water in the soil detected with low voltage input to the microcontroller, the soil wet routine is evaluated. this routine checks the condition according to the fertilizing schedule based on the digital timer. the digital timer is set at 8 a.m in the morning daily for the fertilizing process of the plant. thus, if timer is alarmed with high voltage signal received by the controller, the valve will activate the sprinkler. other wise, if figure 2. water sprinkle flowchart. the voltage from the digital timer is low, the valve will not indicate it is no time to fertilize. the duration set to fertilize the plant is one minute. the next routine is evaluated when the condition for the soil is dry. from here, the controller will first checked the weather condition whether it is raining or not according to the rain detector with rain collector tipping bucket which will be on when it is raining. then watering the lawn is not necessary when the soil is not dry and the process will loop again to the main program and check the activation of all sensors. a. soil moisture sensor the soil moisture sensor presently being developed measures the change in capacitance across the probe as a function of water content in the surrounding soil. the dielectric constant of water is an order of magnitude greater than that of common soil components. in a soil/water matrix, the amount of water present greatly influences the capacitance between two conductive plates placed in the matrix. the picure of the conceptual circuit is shown in figure 3. and figure 4 shows the probe of soil moisture sensor. the crystal oscillator stabilizes the frequency that is produced by the sensor. there are two figure 3. probe of soil moisture sensor. figure 4. circuit diagram of soil moisture sensor. solar-based fuzzy intelligent water sprinkle system (riza muhida, m.j.e. salami, w. astuti, n. amalina, n. rahayu) jmev 02 (2011) 65-72 68 output produced from the oscillator, where one of the output is inverted. after that, a phase detector compares the frequency produced by the sensor blade (capacitor) with frequency of stable source derived from crystal oscillator. the difference is converted to dc output signal. the phase difference is applied to a filter to get smooth frequency. amplifier is also used in the sensor system to amplify any small dc signal from the phase detector to a large voltage or a range of voltage that is suitable to the microcontroller. the microcontroller will continuously detect the signal or output from the sensor to activate or deactivate the valves that allow water to flow through to the sprinkler and for watering a certain area. for example, the output range that is produced by the amplifier (of the sensor) is 0 v to 5 v. so if the voltage output is 5 v, then the microcontroller will understand that the soil is 100% dry and needs water. after that, the valve is on and the sprinkler waters the area. because the water sprinkler system is closed loop system, the microcontroller continuously checks the signal from the sensor blade that is placed in the soil. once the microcontroller detects that the voltage dropped and it tells that the soil is moist enough, the valve is automatically off and no water is supplied to the area. in order to know the suitable voltage range for a few types of soil that will be used in this project, an experiment has been done on those soils. after getting the voltage range, an operational amplifier that can amplify the output of the sensor into a suitable voltage range can be designed. b. rain detector a 2" pvc t-connector is used with 4" diameter funnel attached to it. the dual bucket collector is made from aluminum and the water detector probe is used to detect the state of assembly. the cable wire is then attached to the microcontroller and the program is written to increment a counter on every transition (high or low going) of the sensor’s output line. the diagram of the rain detector is shown below in figure 5. this rain detector was equipped with a circuit as shown in figure 6. the main component is ic 555, where the probe will trigger the timer in ic to give high output, using an npn transistor as an amplifier to gain this signal in order to activate a relay. in normal operation, the relay will be active approximately a second after a signal occurs from the rain detector probe located at the end of the rain collector bucket whenever rain occurs. the relay will remain activated until the signal from the rain detector probe stops or the rain ceases. the output from the relay is measured to be 1.26 v when the relay is activated. this is insufficient for handy board input, to overcome this, two inverters 74ls04 are placed and the output became 4.67 v when activated and 1.24 v when it is deactivated. figure 5. rain detector. figure 6. circuit for rain detector. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 65-72, 2011 p-issn 2087-3379 69 c. liquid fertilizer liquid or water soluble fertilizer are easy to use with the irrigation sprinkler, and like all liquid or water soluble fertilizers, the risk of burning the lawn and plants can be avoided. liquid and water soluble fertilizers are ideal for deep root feeding of shrubs, trees, landscape ornamentals and lawns. it is also easy to apply fertilizer directly to the leaf surface. not only do liquid or water soluble fertilizers immediately feed leaves and roots, but by using liquids harmful runoff can also be avoided. the conceptual design of the fertilizing apparatus is sketched in figure 7. this apparatus gives a continuous addition of a selected amount of fertilizer. the system splits incoming water into the dispenser and underneath the dispenser where a steel washer with an inward faced beveled through-hole along with the cap forms a point of lowest pressure region where the fertilizer is injected into an output fluid flow to the sprinkler and dependent upon different sizes of the cap. d. fuzzy mechanism this controller for water sprinkle system is designed by implementing an intelligent system where the controller will execute its program based on the signal sends from the sensor and makes decision by the rules set based on the weather condition and fertilizing time for the plant. the input of the controller is in the form of voltage drop and the change of resistance in the soil. the set of rules for fuzzy logic approach is as below. input membership function soil_dry soil_wet yes_fert no_fert rainy no_rain output membership function valve1_on ( fertilizing apparatus ) valve1_off valve2_on ( water supply ) valve2_off valve1 = fertilizing apparatus valve2 = water supply rules of the membership function are as below: 1. if soil_dry, yes_fert and rainy then valve1_on, valve2_off 2. if soil_dry, yes_fert and no_rain then valve1_on, valve2_on 3. if soil_dry, no_fert and rainy then valve1_off, valve2_off 4. if soil_dry, no_fert and no_rain then valve1_off, valve2_on 5. if soil_wet, yes_fert then valve1_on , valve2_off 6. if soil_wet, no_fert then valve1_off, valve2_off figure 7. fertilizing apparatus. solar-based fuzzy intelligent water sprinkle system (riza muhida, m.j.e. salami, w. astuti, n. amalina, n. rahayu) jmev 02 (2011) 65-72 70 iii. results figure 8 and 9 show the experimental results for a day data in range of time from 7:15 am to 7:00 pm the data is collected by elapsed time within 15 minutes. the data was collected based on the input and output of the controller. there are three inputs of the controller which are soil moisture sensor, rain detector and fertilizing timer. while the outputs are the 6 v relay controlling the solenoid valves for both the water supply and the fertilizing apparatus. based on figure 8 and 9, when this system worked from 07:00 am, the fertilizing apparatus worked to supply the liquid fertilizes at 08:00 am. the soil moisture sensor always detects the soil condition. at 01:00 pm, when the values of moisture sensor dropped, water valve was on to supply the water. the rain sensor detected the rain condition at 03:00 – 04:30 pm. from the experiment, the output measured from the soil moisture sensor at dry condition was between 1.96 v to 2.94 v. it can be concluded from the graph that more water can be saved if the system can work automatically. the healthy growth of the plant is taken care by the needs of its nutrient as we set the time to fertilize daily and the soil moisture content for different area is measured and over watering will not occur at rain condition. figure 8. performance of soil moisture sensor, fertilizing drop and rain sensor. figure 9. performance of sprinkle watering system. 07:12 am 09:36 am 12:00 pm 02:24 pm 04:48 pm -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 in pu t v ol ta ge (v ol ts ) time (hr) soil moisture sensor fertilizing time rainfall 07:12 am 09:36 am 12:00 pm 02:24 pm 04:48 pm 07:12 pm 0.0 0.5 1.0 1.5 2.0 o ut pu t v al ve 2 (v ol ts ) time (hr) watering time journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 65-72, 2011 p-issn 2087-3379 71 iv. conclusions through this work, we implemented the intelligent system for irrigation and water distribution to make it more efficient to safe water and energy. the overall design of the controller and its system integration on both hardware and software are expected to be realistic and the whole operation meets its objectives. in general, the project was a success, with system performing most of the functions as expected. references [1] information centre of irrigation and drainage icid, 1990. [2] kate ravilious, "a sprinkle of limestone dust makes global warming wishes come true," the new scientist, volume 198, issue 2656, p. 16, 17 may 2008. [3] saleh m. ismail, kiyoshi ozawa, nur a. khondaker, "influence of single and multiple water application timings on yield and water use efficiency in tomato (var. first power)," agricultural water management, volume 95, issue 2, pp. 116-122, february 2008. [4] mahdi gheysari, seyed majid mirlatifi, mohammad bannayan, mehdi homaee, gerrit hoogenboom, "interaction of water and nitrogen on maize grown for silage," agricultural water management, volume 96, issue 5, pp. 809-821, may 2009. [5] yaohu kang, ming chen, shuqin wan, "effects of drip irrigation with saline water on waxy maize (zea mays l. var. ceratina kulesh) in north china plain," agricultural water management, volume 97, issue 9, pp. 1303-1309, september 2010. [6] ming chen, yaohu kang, shuqin wan, shiping liu, "drip irrigation with saline water for oleic sunflower (helianthus annuus l.)," agricultural water management, volume 96, issue 12, pp. 1766-1772, december 2009. [7] öner çetin, demet uygan, "the effect of drip line spacing, irrigation regimes and planting geometries of tomato on yield, irrigation water use efficiency and net return," agricultural water management, volume 95, issue 8, pp. 949-958, august 2008. [8] salah e. el-hendawy, essam a. abd ellattief, mohamed s. ahmed, urs schmidhalter, "irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn," agricultural water management, volume 95, issue 7, pp. 836-844, july 2008. [9] xi liang, derong su, shuxia yin, zhi wang, "leaf water absorption and desorption functions for three turfgrasses," journal of hydrology, volume 376, issue 12, pp. 243-248, 30 september 2009. [10] d. isidoro, d. quílez, r. aragüés, "drainage water quality and end-member identification in la violada irrigation district (spain)," journal of hydrology, volume 382, issue 14, pp. 154-162, 1 march 2010. [11] j.n. ortíz, j.a. de juan, j.m. tarjuelo, "analysis of water application uniformity from a centre pivot irrigator and its effect on sugar beet (beta vulgaris l.) yield," biosystems engineering, volume 105, issue 3, pp. 367-379, march 2010. [12] r. delirhasannia, a.a. sadraddini, a.h. nazemi, d. farsadizadeh, e. playán, "dynamic model for water application using centre pivot irrigation," biosystems engineering, volume 105, issue 4, pp. 476485, april 2010. [13] hong li, tingxian li, robert j. gordon, samuel k. asiedu, kelin hu, "strawberry plant fruiting efficiency and its correlation with solar irradiance, temperature and reflectance water index variation," environmental and experimental botany, volume 68, issue 2, pp. 165-174, april 2010. [14] cs 411 ilcs, intelligent lawn care system (spring 2003). virginia: old dominion university, [online] available: http://www.coursehero.com/file/3285859/il cs/ [accessed: november 20, 2011] [15] aaron wills, (october 25, 2002), "development and test of sensor-aided microcontroller based irrigation system with web browser interface," perth, wa: dept of electrical and computer engineering curtin university pp. 5-6,. [online] available: http://www.jkmicro.com/irrigation_thesis.pd f, [accessed: november 20, 2011] [16] mohd taufiq b, mohd yusof, designing and prototyping of automatic garden watering system. kuala lumpur, malaysia: international islamic university malaysia, 2005. [17] brent q mercham, (apr 2010), using soil moisture sensors to control landscape irrigation. loveland, colorado: northem colorado water conservancy district loveland, [online] available: http://www.docstoc.com/docs/33299632/usi solar-based fuzzy intelligent water sprinkle system (riza muhida, m.j.e. salami, w. astuti, n. amalina, n. rahayu) jmev 02 (2011) 65-72 72 ng-soil-moisture-sensors-to-controllandscape-irrigation [accessed: november 20, 2011] [18] richard r. spencer & mohammed s. ghausi, introduction to electronic circuit design. 1st ed, new jersey: prentice hall, august, 2002. mev mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.17-26 design and implementation of a magnetic levitation system controller using global sliding mode control rudi uswarman a, *, adha imam cahyadi a , oyas wahyunggoro a a department of electrical engineering and information technology, universitas gadjah mada jl. grafika 2, yogyakarta 55281, indonesia received 12 march 2014; received in revised form 16 june 2014; accepted 19 june 2014 published online 23 july 2014 abstract this paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. sliding mode control will be robusting when in sliding mode condition. however, it is not necessarily robust at attaining phase. in the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. however, the value of the parameter uncertainties needs to be limited. besides that, the common problem in sliding mode control is high chattering phenomenon. if the chattering is too large, it can make the system unstable due the limited ability of electronics component. the strategy to overcome the chattering phenomenon is needed. based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control. keywords: magnetic levitation system, global sliding mode control, conventional sliding mode control, chattering. i. introduction magnetic levitation systems (mls) have been widely applied in various fields that aims to help people, such as biomedical [1], maglev train [2], maglev wind tunnel [3], and micro-robotic [4]. several techniques have been implemented to control the magnetic levitation system, for examples using gain scheduling [5], high-gain observers [6], and passivity based control [7, 8]. these controllers do not consider the parameter uncertainties of magnetic levitation system. however, some researchers have used nonlinear controllers considering mass parameter uncertainties of magnetic levitation such as using gain scheduling [5], and sliding mode control [9]. the uncertainty of parameters other than mass is not considered. in this paper, not only uncertainty of the mass but also uncertainties of the other parameters are considered. linear controller is not suitable for control magnetic levitation because the dynamic of magnetic levitation is highly nonlinear. nonlinear controller is needed to overcome the nonlinearity of magnetic levitation. besides that, general problem in mls is uncertainties of the system. the uncertainties are a very challenging task for researchers. these problems can be overcome with robust controller. robust controller are composed of a nominal part, similar to a feedback linearization or inverse control law, and of additional terms aimed at dealing with model uncertainty [10]. sliding mode control technique will be investigated to control position object of mls. sliding mode control is precise controller to solve the problems of the system, because this technique are nonlinear controller and robust from disturbances and parameter uncertainties. sliding mode control technique was initially proposed in the early 1960s. the ideas did not appear outside russia until mid 1970s [11]. the mls consists of an object suspended in a voltage controlled magnetic field. the magnetic field is used to against gravity effect. to adjust the desired position of the object, we can use a controller to change appropriate magnetic field. model of mls is shown in figure 1. * corresponding author.tel: +62-81227632318 e-mail: uswarman@yahoo.com http://ugm.academia.edu/departments/department_of_electrical_engineering_and_information_technology http://dx.doi.org/10.14203/j.mev.2014.v5.17-26 r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 18 ii. dynamics of the mls the lagrangian will be presented to find the mathematical model of a mls. lagrange equations of motion can be written as: 𝑑 𝑑𝑡 𝜕𝐿 𝜕 𝑥 𝑖 − 𝜕𝐿 𝜕 𝑥𝑖 = 0 , 1 ≤ 𝑖 ≤ 𝑛. (1) we now define 𝐿 = 𝑇 − 𝑉; 𝐿 is called the lagrangian, 𝑇 is kinetic energy and 𝑉 is potential energy. the generalized coordinates to be chosen such that 𝑥1 = 𝑥 , 𝑥 1 = 𝑥 , 𝑥 2 = 𝑖 . 𝑥 represent the object position, 𝑥 represent the velocity, and 𝑖 represent the current. the kinetic energy and potential energy can be written as: 𝑇 = 1 2 𝐿 𝑥 𝑖2 + 1 2 𝑚𝑥 2 , 𝑉 = −𝑚𝑔𝑥, (2) where coil inductivity 𝐿(𝑥) is a nonlinear function of the ball’s position, 𝑔 is the gravitational constant, and 𝑚 is the mass of a levitated object. the lagrangian formula can be written as: 𝐿 = 1 2 𝐿 𝑥 𝑖2 + 1 2 𝑚𝑥 2 + 𝑚𝑔𝑥. (3) the approximation coil inductance 𝐿(𝑥) can be written as: 𝐿 𝑥 = 𝐿𝑖 + 𝐿0𝑥0 𝑥 , (4) where 𝐿0 𝑥0 = 2𝑘, 𝐿𝑖 is a system parameter, and 𝑘 is the magnetic force constant. thus, the general form of lagrangian equation can be written as: 𝑥 = 𝑓 𝑚 + 𝑔 − 𝑘 𝑖 2 𝑚𝑋 2 ,and (5) 𝑑𝑖 𝑑𝑡 = 𝑢 𝐿 − 𝑖𝑅 𝐿 + 𝑖 2𝑘 𝐿𝑥 2 𝑥 . (6) taking 𝑥1 = 𝑥, 𝑥2 = 𝑥 , 𝑥3 = 𝑖, 𝑢 = 𝑒. then, we can get state space model of a mls as: 𝑥 1 = 𝑥2 , 𝑥 2 = 𝑔 − 𝑘 𝑥3 2 𝑚𝑥1 2 , 𝑥 3 = − 𝑅𝑥3 𝐿 + 2𝑘𝑥2 𝑥3 𝐿𝑥1 2 + 𝑢 𝐿 . (7) consider the nonlinear change of coordinates. the nonlinear change in coordinates is presented in equation (8). 𝑛1 = 𝑥1 − 𝑥1𝑑 , 𝑛2 = 𝑥2 − 𝑥2𝑑 , 𝑛3 = 𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2 . where 𝑥1 > 0 and 𝑥3 > 0. (8) in the new coordinates, we can get: 𝑛 1 = 𝑛2 , 𝑛2 = 𝑛3 , 𝑛 3 = 𝑓 𝑛 + 𝑔(𝑛)𝑢. (9) differentiating equation (9), then substituting equation (7) into 𝑛 3: 𝑛 3 = − 4𝑘 2𝑥2𝑥3 2 𝑚𝐿 𝑥1 4 + 2𝑘𝑅𝑥3 2 𝑚𝐿 𝑥1 2 + 2𝑘𝑥3 2𝑥2 𝑚 𝑥1 3 − 2𝑘𝑥3𝑢 𝑚 𝑥1 2𝐿 . (10) the function 𝑓 𝑛 and 𝑔(𝑛) are correspondent to the original coordinates: 𝑓 𝑥 = − 4𝑘 2𝑥2𝑥3 2 𝑚𝐿 𝑥1 4 + 2𝑘𝑅 𝑥3 2 𝑚𝐿 𝑥1 2 + 2𝑘 𝑥3 2𝑥2 𝑚 𝑥1 3 , 𝑔 𝑥 = − 2𝑘𝑥3 𝑚 𝑥1 2𝐿 , where 𝑥1 > 0. (11) . figure 1. model of mls r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 19 iii. controller design sliding mode control was first proposed by emel’yanov and barbhasin in the early 1960s [11]. the major advantages of this technique are completely insensitive to variation in system parameters, external disturbances, and modeling errors. the methodology of sliding mode control consists of three components. the first is designing a sliding surface in the state space. the second is designing high switching control law to reach the sliding surface. the third is designing equivalent control law to maintain the system state trajectory on the sliding surface for all subsequent times. a. conventional sliding mode control the first step in conventional sliding mode control (csmc) is designing the switching surface. the sliding surface is defined as: 𝑠 = n 1 + 𝛼𝑛 1 + 𝛽𝑛 1 , (12) substituting equation (8) into equation (12): 𝑠 = 𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2 + 𝛼(𝑥2 − 𝑥2𝑑 ) + 𝛽(𝑥1 − 𝑥1𝑑 ). (13) the switching control law can be written as: 𝑢𝑠 = −𝐴 𝑠𝑖𝑔𝑛 (𝑠), (14) where 𝑠𝑖𝑔𝑛 𝑠 = 1, 𝑠 > 0, 0, 𝑠 = 0, −1, 𝑠 < 0. (15) the sliding mode control technique generally experiences chattering phenomenon, which is an oscilation around sliding surface as an effect of high switching. the saturation function can be used to overcome chattering phenomenon. the technique can be written as: 𝑢𝑠 = −𝐴 𝑠𝑎𝑡 (𝑠), (16) where 𝑠𝑎𝑡 𝑠 𝜑 = 1, 𝑠 𝜑 > 1, 𝑠 𝜑 , 𝑠 𝜑 = 1, −1, 𝑠 𝜑 < 1. (17) the equivalent control design to maintain the system state trajectory is: 𝑠 = 𝑛 1 + 𝛼𝑛 1 + 𝛽𝑛 1. (18) substituting equation (9) and (11) into equation (18): 𝑠 = 𝑓 𝑥 + 𝑔 𝑥 𝑢𝑒𝑞 + α 𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2 + 𝛽(𝑥2 − 𝑥2𝑑 ), (19) and we get equivalent control: 𝑢𝑒𝑞 = 1 𝑔 𝑥 (−𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽(𝑥2 − 𝑥2𝑑 )). (20) finally, we can get the csmc controller as: 𝑢 = 1 𝑔 𝑥 (−𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚𝑥1 2) − 𝛽(𝑥2 − 𝑥2𝑑 )) − 𝐴𝑠𝑎𝑡( 𝑠 𝜑 )). (21) the stability of a controller can be analyzed by lyapunov function. lyapunov function candidate is defined as: 𝑉 = 1 2 𝑆2 > 0, (22) and 𝑉 = 𝑠𝑠 𝑉 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 𝑢𝑒𝑞 + α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) + 𝛽(𝑥2 − 𝑥2𝑑 )), (23) substituting equation (21) into 𝑢𝑒𝑞 in equation (23): 𝑉 = 𝑠𝑠 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 1 𝑔 𝑥 (−𝑓 𝑥 −α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽(𝑥2 − 𝑥2𝑑 )) − 𝐴𝑠𝑎𝑡( 𝑠 𝜑 )) +α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) + 𝛽(𝑥2 − 𝑥2𝑑 )). (24) it can be simplified as: 𝑉 = 𝑠𝑠 < 0 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 1 𝑔 𝑥 −𝑓 𝑥 − 𝐴𝑠𝑎𝑡( 𝑠 𝜑 )). (25) we ensure the stability of our system by choosing a to be large enough so that stable in the sense of lyapunov. b. global sliding mode control the robustness of sliding mode control to disturbances and parameter uncertainties exists in sliding mode condition, and not necessarily robust at attaining phase. in the global sliding mode control (gsmc), the attaining motion phase was eliminated, so that the robustness of the controller can be improved [12-14]. the first step is designing the switching surface. the sliding surface is defined as: 𝑠 = 𝑛 1 + 𝛼n 1 + 𝛽𝑛1 − 𝑟(𝑡), (26) substituting equation (8) into equation (26): 𝑠 = 𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2 + 𝛼 𝑥2 − 𝑥2𝑑 + 𝛽 𝑥1 − 𝑥1𝑑 − 𝑟(𝑡). (27) the additional function 𝑟(𝑡) should be satisfied: 𝑟 0 = 𝑒 0 + 𝛼𝑒 0 + 𝛽𝑒0, (28a) 𝑟 𝑡 → 0 as 𝑡 → ∞, (28b) 𝑟(𝑡) ∈ ℝ′ , (28c) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 20 where 𝑒0 = 𝑒 𝑡 = 0 , 𝛼 > 0, and 𝛽 > 0. equation (28a) represents the initial states on the sliding surface, equation (28b) represents asymptotic stability, and equation (28c) represents the existence of sliding mode (gsmc improved design for a brush). from three conditions to equation (28a), (28b), and (28b), 𝑟(𝑡) can be designed as: 𝑟 𝑡 = 𝑟(0)e−𝑘𝑡 . (29) the switching control law can be written as: 𝑢𝑠 = −(( 1 ∆𝑔 𝑥 (−∆𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽 𝑥2 − 𝑥2𝑑 − 𝑟 )) + 𝐷)𝑠𝑎𝑡 𝑠 𝜑 . (30) the equivalent control to maintain the system state trajectory can be written as: 𝑢𝑒𝑞 = 1 𝑔 𝑥 (−𝑓 𝑥 − α 𝑔 − 𝑘 𝑥3 2 𝑚𝑥1 2 − 𝛽 𝑥2 − 𝑥2𝑑 + 𝑟 ), (31) where 𝑅 = 𝑅𝑚𝑎𝑥 +𝑅𝑚𝑖𝑛 2 , ∆𝑅 = 𝑅𝑚𝑎𝑥 −𝑅𝑚𝑖𝑛 2 , 𝐿 = 𝐿𝑚𝑎𝑥 +𝐿𝑚𝑖𝑛 2 , ∆𝐿 = 𝐿𝑚𝑎𝑥 −𝐿𝑚𝑖𝑛 2 , 𝑚 = 𝑚 𝑚𝑎𝑥 +𝑚 𝑚𝑖𝑛 2 , ∆𝑚 = 𝑚 𝑚𝑎𝑥 −𝑚 𝑚𝑖𝑛 2 , 𝐷 > 0, 𝑓(𝑥) = − 4𝑘 2 𝑥2𝑥3 2 𝑚 𝐿 𝑥1 4 + 2𝑘 𝑅 𝑥3 2 𝑚 𝐿 𝑥1 2 + 2𝑘𝑥3 2𝑥2 𝑚 𝑥1 3 , 𝑔 𝑥 = − 2𝑘 𝑥3 𝑚 𝑥1 2𝐿 , 𝑓 𝑥 = − 4𝑘 2 𝑥2𝑥3 2 ∆𝑚 ∆𝐿𝑥1 4 + 2𝑘 ∆𝑅𝑥3 2 ∆𝑚 ∆𝐿𝑥1 2 + 2𝑘 𝑥3 2𝑥2 ∆𝑚 𝑥1 3 , ∆𝑔 𝑥 = − 2𝑘 𝑥3 ∆𝑚 𝑥1 2∆𝐿 . (32) finally, we can get the gsmc controller: 𝑢 = 1 𝑔 𝑥 (−𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚𝑥1 2) − 𝛽 𝑥2 − 𝑥2𝑑 + 𝑟 ) − (( 1 ∆𝑔 𝑥 (−∆𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽 𝑥2 − 𝑥2𝑑 − 𝑟 )) + 𝐷)𝑠𝑎𝑡 𝑠 𝜑 . (33) lyapunov function candidate is defined as: 𝑉 = 1 2 𝑆2 > 0, (34) and 𝑉 = 𝑠𝑠 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 𝑢𝑒𝑞 + α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) + 𝛽 𝑥2 − 𝑥2𝑑 − 𝑟 ). (35) substituting equation (33) into 𝑢𝑒𝑞 in equation (35): 𝑉 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 1 𝑔 𝑥 (−𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽 𝑥2 − 𝑥2𝑑 + 𝑟 ) − (( 1 ∆𝑔 𝑥 (−∆𝑓 𝑥 − α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) − 𝛽 𝑥2 − 𝑥2𝑑 −)) + 𝐷)𝑠𝑎𝑡 𝑠 𝜑 + α(𝑔 − 𝑘 𝑥3 2 𝑚 𝑥1 2) + 𝛽 𝑥2 − 𝑥2𝑑 − 𝑟 ). (36) it can be simplified: 𝑉 = 𝑠𝑠 < 0 = 𝑠(𝑓 𝑥 + 𝑔 𝑥 1 𝑔 𝑥 (−𝑓 𝑥 ) − (( 1 ∆𝑔 𝑥 −∆𝑓 𝑥 − 𝑟 + 𝐷)𝑠𝑎𝑡 𝑠 𝜑 ). (37) we ensure the stability of our system choosing d to be large enough so that stable in the sense of lyapunov. iv. simulation results the robustness of the csmc and gsmc from parameter uncertainties and disturbance are proposed. furthermore, the chattering phenomenon will be investigated. the parameters of the magnetic levitation system are the gravitational 𝑔 = 9.81 𝑚/𝑠2 , the mass of the object 𝑚 = 340 𝑔 , the coil’s resistance 𝑅 = 7.3 𝛺 , the magnetic force constant 13 ∙ 10−5𝑁𝑚2 /𝐴2, and the inductance 𝐿 = 0.089 𝐻. the simulation results of chattering phenomenon are shown in figure 2 and figure 3. the simulation results of csmc are shown in figure 2 to figure 7. the simulation results of gsmc are shown in figure 8 to figure 11. the chattering phenomenon is considering as a problem in sliding mode control. the simulation in figure 2 shows the controller has high chattering phenomenon and figure 3 shows the position of the object can follow the reference. although the object can follow the reference, in actual plant, chattering phenomenon will make the system unstable due the limited ability of electronics component. the chattering phenomenon can be reduced by saturated function. figure 4 is control versus time for the system without uncertainties. figure 5 shows the object can follow the reference very well. the matches between mathematical model of the controller and dynamics of the magnetic levitation make the system stable. figure 6 and figure 7 are simulation results of the system with uncertainties and disturbance. the parameters in figure 6 and figure 7 are the mass of the object 𝑚 = 340 𝑔 + 20 𝑔 , the coil’s resistance 𝑅 = 7.3 𝛺 + 1.7 𝛺 , and the inductance 𝐿 = 0.089 𝐻 + 0.032 𝐻 .the cosine disturbance is −5 ∗ cos 5 ∗ 𝑡 𝑉. r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 21 figure 2. control with signum function (csmc) figure 3. output with signum function (csmc) figure 4. control without parameter uncertainty and disturbance (csmc) figure 5. output without parameter uncertainty and disturbance (csmc) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 22 figure 7 shows that the object can follow the reference but have larger steady state error than the system without parameter uncertainties and disturbances. simulation results of gsmc are shown in figure 8 to figure 11. figure 8 is control versus time for the system without uncertainties. the position object in figure 9 shows that the object can follow the desired reference and have faster response than csmc. the robustness of controller from disturbance and parameter uncertainties are shown in figure 10 and figure 11. figure 11 shows the object can follow the desire reference more closely than csmc. the parameters in figure 10 and figure 11 are mass of the object 𝑚 = 340 𝑔 + 20 𝑔, the coil’s resistance 𝑅 = 7.3 𝛺 + 1.7 𝛺 , and the inductance 𝐿 = 0.089 𝐻 + 0.032 𝐻. besides that the cosine disturbance −5 ∗ cos 5 ∗ 𝑡 𝑉 is given in figure 10 and figure 11. v. experimental results matlab simulink with block set embedded target for microchip device was used to construct program in the microcontroller. the experiment set up consists of iron ball, dspic33fj128mc802 microcontroller with 16 bit resolution, electromagnet coil, and infrared-photodiode sensor. the output and control was recorded by daq 6009 with 1,000 hz sample rate. the set point position of the object is 1 𝑐𝑚. parameters values were conditioned as follow. nominal mass was 𝑚 = 340 𝑔 , and it was supposed that 𝑅 = 7.3 𝛺 and 𝐿 = 0.089 𝐻. mass deviation was 𝑚 = 340 𝑔 + 20 𝑔. uncertainties of 𝑅 and 𝐿 occur naturally when the temperature of the coil increases. external disturbance was undefined. they can make the system unstable if the controller is not really robust. experimental results of csmc are shown in figure 12 to figure 15. figure 12 describes control versus time for the system without uncertainties. figure 13 shows the object can follow the reference. the matches between mathematical model of the controller and dynamics of the magnetic levitation make the system stable. figure 14 represents control versus time for the system with uncertainties. figure 15 shows the object cannot follow the reference 1 𝑐𝑚 because the csmc is not really overcome the parameter uncertainties. experimental results of gsmc are shown in figure 16 to figure 19. figure 16 is control versus time for the system without uncertainties. the position object in figure 17 shows the object can follow the desired reference. figure 18 is control versus time for the system with uncertainties. the position object in figure 19 shows the object can follow the set point although the parameter uncertainties occur. figure 6. control with parameteruncertainties and disturbance (csmc) figure 7. output with parameter uncertainties and disturbance (csmc) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 23 figure 8. control without parameter uncertainty and disturbance (gsmc) figure 9. output without parameter uncertainty and disturbance (gmsc) figure 10. control with parameter uncertainties and disturbance (gsmc) figure 11. output with parameter uncertainties and disturbance (gsmc) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 24 figure 12. control without parameter uncertainty (csmc) figure 13. output without parameter uncertainty (csmc) figure 14. control with parameter uncertainties (csmc) figure 15. output with parameter uncertainties (csmc) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 25 figure 16. control without parameter uncertainty (gsmc) figure 17. output without parameter uncertainties (gsmc) figure 18. control with parameter uncertainties (gsmc) figure 19. output with parameter uncertainties (gsmc) r. uswarman et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 17-26 26 vi. conclusion this paper described the robustness of csmc and gsmc from disturbances and parameter uncertainties. the csmc is not necessarily robust at attaining phase. the mismatches between mathematical model of the controller and dynamics of the magnetic levitation make the system unstable. the gsmc shows good performance from disturbances and uncertainties. this technique can eliminate the mismatches between mathematical model of the controller and dynamics of the magnetic levitation. in the gsmc, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. however, the value of the parameter uncertainties needs to be limited. based on simulation and experimental results, the gsmc has better performance than csmc. references [1] k. qian, et al., "investigation on applying passive magnetic bearings to impeller left ventricular assist devices," in international conference on biomedical engineering and informatics, 2010, pp. 1516-1518. [2] s. m. jang, et al., "dynamic characteristics of a linear induction motor for predicting operating performance of magnetic vehicles based on electromagnetic field theory," ieee transactions on magnetics, vol. 47, pp. 3673-3676, 2011. [3] c. v. aravind, et al., "a novel magnetic levitation assisted vertical axis wind turbine-design procedure and analysis," in ieee8th international colloqunium on signal processing and its applications, 2012, pp. 93-98. [4] m. hagiwara, et al., "high speed microrobot actuation in amicrofluidic chip by levitated structure with riblet surface," in ieee international conference on robotics and automation, 2012, pp. 25172522. [5] y. c. kim and k. h. kim, "gain scheduled control of magnetic suspension system," in ieee american control conference, 1994, pp. 3127-3131. [6] h. katayama and t. oshima, "stabilitation of a magnetic levitation system by backstepping and high-gain observers," in sice annual conference, 2011, pp. 754-759. [7] m. velasco-villa, et al., "modelling and passivity based control of a magnetic levitation system," in ieee international conference on control applications, 2001, pp. 64-69. [8] t. shimizu, et al., "passivity based control of a magnetic levitation system with two electromagnets for a flexible beam," in ieee international workshop on advanced motion control, 2004, pp. 129-134. [9] n. f. al-muthairi and m. zribi, "sliding mode control of a magnetic levitation system," mathematical problems in engineering, vol. 2004, pp. 93-107, 2004. [10] j.-j. e. slotie and w. lie, applied nonlinear control. new jersey: prentice hall, 1991. [11] c. edwards and s. k. spurgeon, sliding mode control: theory and applications: crc press, 1998. [12] j. liu and x. wang, advanced sliding mode control for mechanical systems beijing: tsinghua university press, 2011. [13] h.-s. choi, et al. (2001) global slidingmode control improved design for a brushless dc motor. control systems, ieee. 27-35. [14] s. z. zhang and x. l. ma, "a pmsm sliding mode control system based on exponential reaching law," in international on computational aspects of social networks, 2010, pp. 412-414. mev j. mechatron. electr. power veh. technol. 06 (2015) 97-104 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.97-104 study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system hilman syaeful alam a, *, john sasso b, imam djunaedi c atechnical implementation unit for instrumentation development, indonesian institute of sciences jl. sangkuriang komplek lipi gedung 30 bandung, 40135, indonesia brrt sigma engineering, one huntington quadrangle 3s-01 melville, new york, 11747, usa cresearch center for physics, indonesian institute of sciences jl. sangkuriang komplek lipi gedung 80 lantai 2 bandung, 40135, indonesia received 5 may 2015; received in revised form 26 august 2015; accepted 17 september 2015 published online 30 december 2015 abstract the study is intended to improve the performance of gas turbine engines in order to meet both electrical power demand and peak load in the power plant. in this paper, evaporative cooling system had been applied to improve the performance of gas turbine in pesanggaran power plant in southern bali island, indonesia. moreover, the economic analysis was conducted to determine the capacity cost, operating cost and payback period due to the investment cost of the system. based on the evaluation results, the power improvement for the three gas turbine units (gt1, gt2 and gt3) are 2.09%, 1.38%, and 1.28%, respectively. these results were not very significant when compared to the previous studies as well as on the aspects of sfc (specific fuel consumption), heat rate and thermal efficiency. based on the evaluation of the economic aspects, the reduction of production costs due to the application of evaporative cooling system was not economical, because it could not compensate the investment cost of the system and it resulted a very long payback period. these unsatisfactory results could be caused by the high relative humidity. therefore, further studies are needed to investigate the other alternative technologies which are more suitable to the climate conditions in indonesia. keywords: performance improvement; economic analysis; evaporative cooling; gas turbine; power plant. i. introduction gas turbines are the constant volume machines which always move the same volume of air at the given shaft speed. since the combusted air is taken directly from the environment, their performance is strongly affected by ambient temperature. the power output of a gas turbine depends on the flow of mass through it. in hot days when air is less dense, power output falls off. a rise of 1°c temperature of inlet air decreases the power output by 1% [1]. the simplest way to overcome the problem is to decrease the temperature of the inlet air. inlet air cooling is considered the most effective technique to increase the power output as well as thermal efficiency of industrial gas turbines. in general, the inlet air cooling technology on the gas turbine system can be classified into three types: evaporative cooling, chiling and fogging. evaporative cooling is the most widely used method for power augmentation of gas turbine because it remains a most costs-efficient method for temperature control of the gas turbine inlet air supply [2]. several studies have been done related to the issue of power augmentation, for simple cycle and combined cycle gas turbine using evaporative cooling technique [2-9]. hamdan et al. [2] conducted a study on the performance improvement of a simple cycle gas turbine with a nominal rating of 250 mw. this engine is operated at shuaiba power plant in kuwait. the obtained results shows that the system appears to *corresponding author. tel: +62-22-2503053 e-mail: alam_hilman@yahoo.com http://dx.doi.org/10.14203/j.mev.2015.v6.97-104 h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 98 be capable of boosting generated power for about 11.07%. santos et al. [3] did the same study but applied to non-commercial gas turbine in brazilian sites with increased power reached 9.65%. hosseini et al. [4] resulted in an increased output power of up to 13.3% which was applied to the combined cycle gas turbine power plant in fars, iran. in this study, performance improvement of a simple cycle gas turbine using evaporative cooling system will be analyzed according to the different climatic conditions with previous studies. the case study was conducted in pesanggaran power plant which owned and operated by indonesia power. this power plant is located in southern bali island, indonesia, the load peaks occur during the early and late evening when the tourist hotels demand the most electricity. moreover, the economic analysis was conducted to determine the capacity cost, operating cost and payback period due to the investment cost of the evaporative cooling system on the gas turbine. ii. materials and methods a. basic of gas turbine cycle the basic of gas turbine operating cycle which also called brayton cycle is depicted in figure 1. it consists of a compression stage, a heat addition (combustion) stage and an expansion stage (turbine). according to santos et al. [3] and oyedepo et al. [5], the following is the thermodynamic calculation for an open simple gas turbine cycle. in the existing condition or without a cooling system, the compressor inlet temperature is equal to ambient temperature, thus the inlet pressure is given by 𝑃0 = 𝑃03 (1) where p0 is inlet pressure, and p03 is ambient pressure. the air and combustion products are assumed as ideal gases. the pressure of the air leaving the compressor (𝑃04) is calculated as: 𝑃04 = 𝑟 𝑃03 (2) where r is the compression ratio. assuming an ideal gas for state 04, the total temperature of the fluid leaving the compressor (𝑇04) can be evaluated using ideal gas relations: 𝑇04 = 𝑇03 𝜂𝑐 [( 𝑃04 𝑃03 ) 𝛾−1 𝛾 − 1] + 𝑇03 (3) where t03 is ambient temperature, 𝜂𝑐 is the compressor efficiency and γ is the specific heat ratio. the compressor work (�̇�𝐶 ) is calculated from the mass flow rate and enthalpy change across the compressor as follows: �̇�𝐶 = �̇�𝑎 𝐶𝑝𝑎(𝑇04 − 𝑇03) (4) where �̇�𝑎 is the air-mass flow rate and 𝐶𝑝𝑎 is the specific heat capacity of air at constant pressure. the turbine inlet pressure ( 𝑃05 ) can be calculated as: 𝑃05 = 𝑃04(1 − 𝛥𝑃𝑐𝑐 ) (5) where 𝑃05 is the turbine entry level pressure, 𝑃04 is the combustion chamber inlet pressure, and 𝛥𝑃𝑐𝑐 is pressure drop across the combustion chamber. the heat delivered by the combustion chamber (�̇�𝑖𝑛 ) is determined from energy balance: �̇�𝑖𝑛 = 𝐶𝑝𝑔 (𝑇05 − 𝑇04) (6) where 𝐶𝑝𝑔 is the specific heat capacity of combustion products and t05 is the turbine inlet temperature. by knowing lower heating value (𝐿𝐻𝑉) of the fuel gas, the mass flow rate of fuel (�̇�𝑓 ) is computed as: �̇�𝑓 = �̇�𝑖𝑛 𝐿𝐻𝑉 𝜂𝑐𝑜𝑚 (7) where 𝜂𝑐𝑜𝑚 is combustor efficiency. the exhaust temperature of the gas that leaves the turbine (𝑇06) can be written as: 𝑇06 = 𝑇05 {1 − 𝜂𝑇 [1 − (( 𝑃05 𝑃06 ) 1−𝛾𝑔 𝛾𝑔 )]} (8) where 𝜂𝑇 is the turbine isentropic efficiency and 𝑃06 is the ambient pressure. hence, the turbine power (�̇�𝑇 ) is equal to: �̇�𝑇 = �̇�𝑔𝑐𝑝𝑔 (𝑇05 − 𝑇06) (9) where �̇�𝑔 is the total mass flow rate of flue gas. it is composed of fuel and air mass flow rate(�̇�𝑔) and given by �̇�𝑔 = �̇�𝑎 + �̇�𝑓 (10) figure 1. schematic of the standard gas turbine cycle h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 99 the net power obtained from the gas turbine (�̇�𝑁𝑒𝑡 ) is given by: �̇�𝑁𝑒𝑡 = �̇�𝑇 − �̇�𝑐 (11) the specific fuel consumption (sfc) compares the ratio of the fuel used by an engine to a characteristic power such as the amount of power produced by the engine [5]. sfc is determined by equation: 𝑆𝐹𝐶 = 3600 �̇�𝑓 �̇�𝑁𝑒𝑡 (12) another important gas turbine parameter is the heat rate (hr) of a gas turbine cycle determined by: 𝐻𝑅 = 𝑆𝐹𝐶 𝑥 𝐿𝐻𝑉 (13) therefore, the thermal efficiency of the gas turbine (𝜂𝑡ℎ ) is calculated as: 𝜂𝑡ℎ = �̇�𝑁𝑒𝑡 �̇�𝑓 𝐿𝐻𝑉 (14) b. evaporative cooling system figure 2 shows a schematic diagram of a gas turbine cycle with evaporative cooling system that is placed in the inlet compressor. evaporative cooling is a passive process which the schematic can be seen in figure 3. in the evaporative cooling system, a wet media is installed in the cross-section of the gas turbine filter house. the media is kept wet using high quality water, such as that from a reverse osmosis unit. the air entering the filter house passes over the saturated media, and the water contained in the media evaporates into the air stream on its way to the gas turbine [10]. the extent of the evaporation and the decreased of temperature is inversely proportional to the percentage of a humidity in the air stream [5], as shown in the saturation process in the psychrometric chart in figure 4. according to santos et al. [3], the inlet air temperature after the cooling process (𝑇03) in figure 2 can be calculated as: 𝑇03 = 𝑇𝑏02 − 𝜀(𝑇𝑏02 − 𝑇𝑤02) (15) where 𝑇𝑏02 is the dry-bulb temperature, 𝑇𝑤02 is the wet-bulb temperature and 𝜀 is the cooling effectiveness. the evaporated water mass flow associated with the evaporative cooling (�̇�𝑤) is given by: �̇�𝑤 = �̇�𝑎 (𝜔02 − 𝜔03) (16) where �̇�𝑎 is the air mass flow rate and 𝜔02 and 𝜔03 is the specific humidity in the inlet and outlet of the evaporative system respectively. the cooling load due to evaporative cooling system (�̇�𝐶𝐿 ) can be calculated by [5]: �̇�𝐶𝐿 = �̇�𝑎 𝐶𝑝𝑎,𝑎𝑣𝑔 (𝑇02 − 𝑇03) (17) where 𝐶𝑝𝑎,𝑎𝑣𝑔 is the specific heat of dry air at constant pressure, determined as a function of the average temperature across the evaporative system. c. existing performance data table 1 summarizes the three gas turbines, manufacturer, years of commissioning and design capacity that are located at the pesanggaran site. the existing performance of the three gas turbines is based on the latest plant performance test results which are shown in table 2. figure 2. schematic diagram of the gas turbine cycle with cooling system figure 3. schematic diagram of evaporative cooler figure 4. saturation process in the psychrometric chart h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 100 d. evaluation methodology gtpro, a power cycle thermodynamic computer modeling software, was utilized to conduct the performance evaluation of the addition of evaporative cooling system on the three unit of gas turbine in pesanggaran site. the first step of evaluation is to replicate the new and clean (n&c) performance of each gas turbine at the design ambient conditions when the unit was installed. site specific conditions are entered such as generator voltage, line voltage, site specific fuel composition, gt starter mechanism, and others. using gtpro, the model is run at the ambient conditions of the latest performance test provided by the plant. degradation factor can be calculated by comparing the corrected performance divided by the n&c performance. each gt is then modelled in gtpro with each of the performance improvements under consideration. the analysis is focused on power output, fuel consumption, heat rate, and thermal efficiency. an estimation of the cost to install the gas turbine in current year dollars is determined using the gtpro capital cost estimating segment of the computer program (peace). it is assumed to use the default cost multipliers for indonesia provided in gtpro for commodities, equipment, labor and materials which can be seen in table 3. the evaluation was focused to determine the capacity cost, operating cost and payback period due to the investment cost of the evaporative cooling system on the gas turbine. iii. results & discussions based on the evaluation methodology, the performance of gas turbine (gt) was analyzed using gtpro simulation. the initial step in the simulation is to analyze the effect of operating hours to the performance of new and clean (n&c) condition, therefore the results of evaluation before and after the addition of evaporative cooling system can be corrected by the degradation factor. the simulation results for the n&c performance of gt unit 2 (gt2) can be seen in figure 5, while the result for the latest performance test can be seen in figure 6. based on these results, the degradation factor for the gt2 can be estimated at 2.4%, the value is derived from the net amount of power based on the performance test divided by net power based on the n&c performance. degradation factors then are taken into account in the analysis of base and new performance by adding evaporative cooling system. the simulation results of the base performance with degradation factor for gt2 can be seen in figure 7, while the simulation results of new performance for gt2 by entering the degradation factor and cooling system is shown in figure 8. evaporative cooling process is designed with an increase in relative humidity approaching 100% saturation point where the ambient air conditions that were used as a reference in the analysis is the condition at the latest of the performance test. the ambient conditions in gt2 due to cooling process can be shown in the psychrometric chart in figure 9. the ambient conditions before cooling are pressure at 14.69 psia, temperature at 80.6of and relative humidity (rh) at 83%. after passing through the evaporative cooling system, an increase in relative humidity reaches 98.04%, which resulted in a decrease in temperature at the table 1. pesanggaran gas turbine installation summary gt oem model yr cap. [mw] tamb (oc) 1 ge ms-500-l 1993 20.10 (b) 23.05 (p) 30 2 siemens cw-251-b11 1994 42.07 27 3 siemens cw-251-b11 1994 42.07 27 table 2. gas turbine performance summary gt last capacity test date test results (mw) aux. loads (kw) tamb (°c) 1 15/01/14 (7pm-8pm) 16.30 220 30 2 06/01/14 (7pm-8pm) 39.80 161 30 3 19/01/14 (7pm-8pm) 35.40 98 30 table 3. cost factors gtpro recommended for indonesia category factor for indonesia specialized equipment 1.05 other equipment 0.75 commodities 0.65 labor 0.54 h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 101 compressor inlet into 76.61of (dropped 4.95%) and pressure at 14.51 psia (dropped 1.23%). a decrease in temperature at the compressor inlet impact on the performance improvement of the gas turbine. summary performance improvement of gas turbine in pesanggaran power plant for unit 1 (gt1), unit 2 (gt2), and unit 3 (gt3) can be seen in table 4, whereas the comparison between new three gt performance against the base performance can be seen in figure 10. an increased power in the gas turbine as a result of the addition of evaporative cooling system can be referred to the additional net power which is calculated from the new power reduced by base power and parasitic load. parasitic load is the extra power needed to run the cooling system that reduces the net power output of the gas turbine. based on simulation results, the power improvement for the three gas turbine units (gt1, gt2, and gt3) respectively are 2.09%, 1.38%, and 1.28%. based on the aspect of fuel consumption per power generated (sfc), there has been a decrease in incremental of sfc for figure 5. the simulation results of gt 2 for new & clean performance figure 6. the simulation results of gt 2 for the latest performance test figure 7. the simulation results of gt 2 for the base performance with degradation factor figure 8. simulation result of new gt performance with degradation factor and evaporative cooling h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 102 gt1 and gt 3 for about 0.93% and 0.40%, so the fuel consumption is lower than existing conditions respectively. however on gt2, incremental of sfc against existing conditions is increased up to 0.20%, this is because the degradation factor on gt 2 is 2.4% which is smaller than gt1 and gt3 that has the same degradation factor of 13.2%. therefore the application of evaporative cooling system on gt2 which has a performance similar to the n&c conditions is considered not economical to be applied. this applies also to the value of incremental heat rate which is equal to the incremental sfc as a function of the same parameters. the incremental value for gt1, gt2, and gt3 respectively are ˗0.93%, 0.20%, and ˗0.40%. based on the aspects of thermal efficiency, the improvement occurred in gt1 and gt3 with the efficiency improvement from the existing condition respectively are 0.23% and 0.12%, while in gt2 the decrease in thermal efficiency is 0.06%. the addition of evaporative cooling system on gas turbine has an impact on the additional cost, i.e. the investment or capacity cost. the calculation results of capacity cost using peace due to the addition of evaporative cooling system can be shown in table 5. the investment costs are estimated based on the costs required for new plant with the addition of cooling system and the demineralized water plant reduced by the cost of base plant. if divided by the additional energy generated from addition of evaporative cooling system, the incremental capacity cost for gt1, gt2 and gt3 are 1,358.0, 1,023.1, and 1,244.1 usd/kwh, respectively. the incremental cost of capacity should ideally be balanced with a decrease in production costs due to the addition evaporative cooling system, so the payback period of the investment can be estimated. assuming the gas turbine operated for 2000 hours in a year and fuel costs figure 9. psychrometric chart of gt inlet air after cooling process figure 10. performance comparison between three gt units after using evaporative cooling system against the base performance h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 103 of 0.88 usd/liter [11], the annual production cost can be shown in table 6. the ratio between the cost of fuel and energy produced can generate average power cost in one year. the difference in fuel consumption between the existing conditions (base) and after the application of cooling system (new) can be expressed as the incremental average power cost in usd/kwh per year. an average power cost reduction for gt1 and gt3 of one year respectively are 0.0032 usd/kwh and 0.0011 usd/kwh, however for gt2 increases at 0.0005 usd/kwh, so the evaporative cooling system on gt2 is not economical. if the decrease in annual production costs on the gt1 and gt3 is compared to the investment cost of the cooling system, the fastest payback period can reach until 544 years. iv. conclusion performance of improvement analysis of gas turbine in pesanggaran power plant due to the addition of the evaporative cooling system is focused on increasing power, specific fuel consumption (sfc), heat rate and thermal efficiency. based on the evaluation results, the power improvement for the three gas turbine table 4. performance of the three unit of gas turbine (gt) in pesanggaran plant parameter gt 1 gt 2 gt 3 base power, kw 16,203 40,743 36,249 new power, kw 16,548 41,316 36,722 new parasitic load, kw 7 10 10 additional net power, kw 338 563 463 base heat rate, btu/kwh 13695.0 11004.0 11423.0 new heat rate, btu/kwh 13567.0 11026.0 11377.0 incremental heat rate, btu/kwh -128.0 22.000 -46.000 base specific fuel consumption, liter/kwh 0.387 0.311 0.323 new specific fuel consumption, liter/kwh 0.383 0.311 0.321 incremental specific fuel consumption, liter/kwh -0.00362 0.00062 -0.00130 base thermal efficiency 24.92% 31.01% 29.87% new thermal efficiency 25.15% 30.95% 29.99% incremental thermal efficiency 0.23% -0.06% 0.12% table 5. capacity cost evaluation results for the three unit of gas turbine (gt) in pesanggaran plant parameter gt 1 gt 2 gt 3 additional net power due to cooling sytem, kw 338 563 463 cost base plant, kusd 22,232 33,379 33,379 cost new plant, kusd 22,656 33,905 33,905 cost demin/ro plant, kusd 35 50 50 estimated cost of cooling system, kusd 459 576 576 capacity cost of cooling system, usd/kwh 1,358.0 1,023.1 1,244.1 table 6. operating cost evaluation results for the three unit of gas turbine (gt) in pesanggaran plant for one year (2000 hr) parameter gt 1 gt 2 gt 3 base electric energy generated, mwh 32,406.0 81,486.0 72,498.0 new electric energy generated, mwh 33,082.0 82,612.0 73,424.0 base annual total fuel consumption, kilter 12,535.9 25,328.1 23,392.5 new annual total fuel consumption, kilter 12,677.8 25,729.5 23,595.8 base annual fuel cost, kusd 11,031.6 22,288.8 20,585.4 new annual fuel cost, kusd 11,156.5 22,641.9 20,764.3 base average power cost, usd/kwh 0.3404 0.2735 0.2839 new average power cost, usd/kwh 0.3372 0.2741 0.2828 incremental average power cost, usd/kwh -0.0032 0.0005 -0.0011 h.s. alam et al. / j. mechatron. electr. power veh. technol. 06 (2015) 97-104 104 units (gt1, gt2, and gt3) respectively are 2.09 %, 1.38 %, and 1.28%. these results are not very significant compared to the previous studies with the enhancement of power ranges between 5-13.3%. these apply also to the sfc, heat rate and thermal efficiency, where the influence of evaporative cooling system does not have a significant impact to the performance of the gas turbine. this could be caused by the high relative humidity in pesanggaran site so that a decrease in turbine inlet temperature from the existing conditions is less effective only around 4.95%, whereas in previous studies could reach between 30-35%. based on the evaluation of the economic aspects, capacity costs which are calculated from the investment cost of the evaporative cooling system and demineralized water plan for gt1, gt2 and gt3, respectively are 1,358.0, 1,023.1 and 1,244.1 usd/kwh. these capacity costs should be balanced with a decrease in the production cost. however the production costs reduction due to the evaporative cooling system application on the three units of gas turbine was not economical because it could not compensate the investment cost of the system and it resulted a very long payback period. further studies are needed to investigate the other alternative technologies which are more suitable to the climate conditions in indonesia. acknowledgement this research is motivated by a memorandum of understanding (mou) which has been implemented by the indonesian institute of sciences (lipi) and pt. indonesia power in the fields of research and development of electricity on november 7, 2011 with the mou number: 8.mou/2/ip/2011 and 10/ks/lipi/ix/2011. references [1] thamir k. ibrahim et al., “improvement of gas turbine performance based on inlet air cooling systems: a technical review,” international journal of physical sciences, vol. 6(4), 18 february, 2011, pp. 620-627. [2] o. r. al-hamdan and a. a. saker, “studying the role played by evaporative cooler on the performance of ge gas turbine existed in shuaiba north electric generator power plant, ” energy and power engineering, vol. 5, 2013, pp. 391-400. [3] a. p. santos and c. r. andrade, “analysis of gas turbine performance with inlet air cooling techniques applied to brazilian sites,” j. aerospace. technol. manag., vol.4, no 3, jul.-sep., 2012, pp. 341-353. [4] r. hosseini et al., “performance improvement of gas turbines of fars (iran) combined cycle power plant by intake air cooling using a media evaporative cooler,” energy conversion and management, vol. 48, 2007, pp. 1055–1064. [5] s. o. oyedepo and o. kilanko, “thermodynamic analysis of a gas turbine power plant modeled with an evaporative cooler,” international journal of thermodynamics, vol. 17, no. 1, 2014, pp. 14-20. [6] s. agarwal et al., “performance improvement of a regenerative gas turbine cycle through integrated inlet air evaporative cooling and steam injection,” international journal of emerging technology and advanced engineering, vol. 2, issue 12, december 2012, pp. 354-363. [7] e. farvaresh et al., “investigation of gas turbine intake air cooling via evaporative media and its effects on cartridge filters pressures drop,” international journal of occupational hygiene, vol. 6, no. 2, 2014, pp. 75-80. [8] a. d. pascale et al., “analysis of inlet air cooling for igcc power augmentation,” energy procedia, vol. 45, 2014, pp. 12651274. [9] r. espanani et al., “efficiency improvement methods of gas turbine,” energy and environmental engineering, vol. 1(2), 2013, pp. 36-54. [10] technical report, evaluation of gas turbine performance improvement alternatives for indonesia power, power phase llc and indonesian institute of sciences, no. 1246-001-01, january 28, 2015. [11] indonesia diesel prices, liter, available at: http://www.globalpetrolprices.com/indonesi a/diesel_prices/. http://www.globalpetrolprices.com/indonesia/diesel_prices/ http://www.globalpetrolprices.com/indonesia/diesel_prices/ mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.65-74 design and development of a control system for nanofiber electrospinning dayat kurniawan a, *, purwoko adhi a , muhammad nasir b a research center for electronics and telecommunication, indonesian institute of sciences kampus lipi, jl. sangkuriang, gd. 20, bandung 40135, indonesia b research center for chemical, indonesian institute of sciences kampus lipi, jl. sangkuriang, gd. 80, bandung 40135, indonesia received 14 may 2013; received in revised form 16 october 2013; accepted 17 october 2013 published online 24 december 2013 abstract this paper describes the development of a control hardware and software for a nano-fiber electro-spinning system. the hardware consists of motor driver boards, a high dc voltage board, and a main control board. the user interface software on pc is developed using visual studio c # 2010 express edition. the motor driver boards are controlled by an atmega8 microcontroller ic, while the main board is controlled by an atmega 128 microcontroller ic. communication between the main board and the motor driver boards uses the inter integrated circuit (i2c), while communication between pc and the main board uses a serial communication at a baud rate of 9,600 bps. the high dc voltage generator is designed to have an output of 0-25 kv. high dc voltage output is configurable by giving a combination of low logic and high impedance into a six bit input. the result show that maximum output of high dc voltage is 25.025 kv with formula of curve is y = 1x – 0.0244 with r2 = 0.9998 and pc software interface can work very well. polymer flow rate can be configured from pc interface software via i2c connected to the main board. the flow rate y follows the rpm setting x, according to the formula y = 0.954x – 0.0099 with r2 = 1. the results of scanning electron microscope (sem) for morphology analysis of pvdf copolymer composite nano-fiber shows that the average diameter of the resulted fiber is 136.43 nm, when output high dc voltage is set to 15 kv and speed of syringe pump is set to 5 rpm. keywords: electrospinning, high dc voltage, i2c, motor driver, microcontroller, pc interface software. i. introduction polymer nanofiber can be applied in several areas such as biomedical, textile industry, filtration, and others [1-3]. one technique to make nanofibers is electrospinning. electrospinning technology is chosen because it has several advantages such as ease of use, adaptability, and the ability to fabricate fibers with diameters on the nanometer size scale. the principle of electrospinning is giving high dc voltage source to form a polymer solution jet and arrested at the collector [4, 5]. a typical electrospinning setup consists of a capillary through which the liquid to be electrospun is forced, a high voltage source with positive or negative polarity, which injects charge into the liquid, and a grounded collector (figure 1) [6]. control system for nanofiber electrospinning is developed to control and to monitor electrospinning system by pc. the main parts of electrospinning system are high dc voltage and motor driver for syringe pump. high dc voltage controller is designed to control and to monitor the output voltage by microcontroller. motor driver is designed to drive stepper motor with four phase and maximum current of 1 a. the inter integrated circuit (i2c) is used for communication between main board and motor drivers, while usb to serial protocol is used for communication between main board and pc software. i2c allows an atmega128 microcontroller ic to be connected to up to 128 motor driver’s board with different address [7]. this paper discusses the development of control system for electrospinning nanofiber based on interface software installed on a pc and microcontroller ic. *corresponding author. tel.: +62-8122-0440-463 e-mail: daysdk63@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.65-74 d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 66 ii. design a. system architecture the system consists of electronic boards and software installed on a pc. the electronic boards are a main board, a high dc voltage board, and some motor driver boards. the main board is controlled by atmega128 microcontroller, while the motor driver boards are controlled by atmega8. communication between the main board and the motor drivers uses i2c protocol, while the main board communicates with pc using a usb to serial converter. the main board is configured as master and motor driver are configured as slave. the number of motor drivers that can be connected to this i2c bus is 128 with different slave addresses [7]. microcontroller atmega128 ic in the main board has function to extract data from pc and then send it to motor driver boards to control stepper motors, like speed, on/off and direction. another function of the atmega128 is to regulate and monitor the output voltage of the high dc voltage. pc software interface is also equipped with the ability to monitor the movement of the syringe pump using a webcam and have a time schedule facility to configure output voltage of the dc high voltage, the speed of stepper motor, also the system start and stop. block diagram of the system is shown in figure 2. b. high dc voltage high dc voltage generator is designed to produce output in the range of 0-25 kv. the main component of high dc voltage is uc3842 ic and flyback transformer. the principle of high dc voltage is giving signal with certain frequency and duty cycle in order to drive the flyback transformer to generate output of 0-25 kv. the operating frequency of the flyback transformer is from 1.5 khz to 82.5 khz [8]. the operating frequency generated by uc3842 ic depends on the ct and rt values which are connected to pin 8, 4, and 5 as shown in figure 3 [9]. operating frequency about 36 khz is to be used in this design. this value is the optimum frequency of the flyback transformer used in this design. the output frequency can be calculated by equation (1) [9]. 𝑓𝑜𝑟𝑅𝑇 > 5𝐾 𝑓𝑜𝑢𝑡 = 1.72 𝐶𝑇∗𝑅𝑇 (1) to obtain fout = 36 khz, rt = 10 k and ct = 4.7 nf can be used. figure 1. electrospinning system setup [6] main board (atmega128a) control motor syringe 1 (atmega8) control motor syringe 2 (atmega8) control motor stepper verical (atmega8) control motor stepper horizontal (atmega8) usb i2 c b u s high dc voltage u s b figure 2. electrospinning system block diagram figure 3. oscilator using uc3842 ic [9] d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 67 c. main board the main board extracts data from pc and then sends it to driver motor board to control the speed of stepper motor. it also controls and monitors the output voltage of the high dc voltage generator. the main component of main board is microcontroller atmega128 ic. microcontroller atmega128 ic has some feature such as 128 kbyte of flash program, 4 kbyte eeprom, 4 kbyte internal sram, about 48 i/o pin, 16 bit timer/counters, 6 pwm channels, 8 channel 10 bit adc, two wire serial interface (twi/i2c), dual programmable serial usart and so on [7]. communication between microcontroller atmega128 ic and pc uses serial port. for simple operation reason, the ft232rl ic used in this design as converter from serial to usb port pc. serial communication is set to a baud rate of 9,600 bps, one stop bit, and none parity. after receiving data from the pc, microcontroller atmega128 ic will extract motor data and then send it to the motor driver or extract high voltage setting and set the high dc voltage generator output. communication between microcontroller atmega128 ic and motor driver board uses i2c protocol, where atmega128 is set as a master and motor driver boards are set as slaves. the communication system of microcontroller atmega128 is shown in figure 4. d. motor driver board the motor drivers control motor speed, direction and on/off state. the main component of the motor driver boards are microcontroller atmega8 ic and ucn5804b ic. the microcontroller atmega8 has some feature such as 8 kbyte of flash programming, 512 of kbyte eeprom, 1 kbyte of internal sram, three pwm channel, timer/counter, two wire serial interfaces (twi/i2c) and so on. ucn5804b ic is a bimos ii unipolar stepper motor translator/driver which has the ability to control and drive a four phase unipolar stepper motor with continuous output current ratings to 1.25 a per phase (1.5 a startup) and 35 v [10]. the motor speed can be adjusted with giving signal with different frequency for different speed on pin 11 of ucn5804b ic. on/off motor can be done by giving logic low/high on pin 15 while the direction of motor on pin 14 of ucn5804b ic. the function of microcontroller atmega8 ic on the motor driver board are to communicate with the main board, to generate frequency to control motor speed, and to give low/high logic to control on/off or direction of the motor. microcontroller atmega8 uses timer/counter that was operated in clear timer on compare match (ctc) mode to generate frequency. motor driver circuit uses ucn5804b ic is shown in figure 5. ft232rl atmega128 usb serial i2c pc/laptop n driver motor figure 4. communication system of microcontroller atmega128 ic figure 5. motor driver uses ucn5804b ic [10] d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 68 e. pc software interface pc interface software serves as a graphical user interface (gui) to control the electrospinning system through computer. visual c# 2010 express edition used to develop this gui. a packet data sent from this gui to main board through usb port to control motor speed and high dc voltage output. format packet data is shown in figure 6. where:  header  1 byte, contain ”@” character  id  1 byte data, contain id address of driver motor board  function  1 byte, describes function of motor control like speed, direction, on/off or function of regulating high dc voltage  data  n byte data  tail  1 byte, contain ”#” character iii. implementation a. high dc voltage high dc voltage output is configurable by setting a combination of low logic and high impedance into a six bit input. the combination input and output high dc voltage is shown in table 1. 0 represents 0 v and 1 represents high impedance. high dc voltage input circuit is shown in figure 7. the input of high dc voltage is connected to port c.0 to port c.5 of the table 1. combinations of input and output combinations (msb-lsb) output voltage (kv) 000000 0 000001 1 000010 2 000011 3 000100 4 000101 5 000110 6 000111 7 001000 8 001001 9 001010 10 001011 11 001100 12 001110 13 001111 14 010000 15 010001 16 010010 17 010011 18 010100 19 010101 20 010110 21 010111 22 011000 23 011001 24 011010 25 header id function data tail figure 6. serial data packet format figure 7. high dc voltage input circuit d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 69 atmega128 microcontroller ic. b. main board microcontroller atmega128 ic has enough i/o to connect with other peripheral in this system such as liquid crystal display (lcd), keypad, max232 ic, ft232rl ic and the other. minimum system of the main board is shown in figure 8. port a.0-7 is connected to limit switches of syringe pump, horizontal, and vertical motors. port b.2-5 are connected to keypad while port c.0-5 are connected to high dc voltage control input i2c bus using port d.0 as clock signal and port d.1 as data. serial data communication uses port d.2 as receiver and port d.3 as transmitter. lcd control input is connected to port f.4-7. port f.0-3 is used as adc for monitor of high dc voltage output. the program flowchart implemented in the atmega128 is shown in figure 9. c. motor driver the motor drivers consist of microcontroller atmega8 ic and uc5804b ic. communication between atmega8 and atmega128 microcontroller ics uses i2c protocol. in this figure 8. minimum system of main board start serial initialization i/o,adc check data packet data packet for motor driver data packet for high dc voltage send to motor driver set high dc voltage, monitor adc clear buffer data n y y y n figure 9. program flowchart of atmega128 d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 70 system, atmega8 are configured as slaves. the slaves addresses configured by giving logical low or high on port c.0 – port c.3. port d.4 is connected to pin 15 of ucn5804 ic which is used to control of on/off motor. port d.5 is connected to pin 14 of ucn5804b ic which is used to control the motor direction. port b.1 is connected to pin 11 of ucn5804b ic which is used to control motor speed. port b.1 is configured as output of timer/counter 1 a which is configured in ctc mode. port c.4 is used as data signal of i2c while port c.5 is used as clock signal. the minimum system of motor driver board is shown in figure 10. atmega8 microcontroller ics will extract data from the main board before controlling motors. it is done by comparing address data from main board with atmega8 own address data. for monitoring the control mode of atmega8 microcontroller ic, two led, which connected to port d.2 and port d.3, are used. d. pc software interface communication between pc and the main board uses serial port. interface software will check all active serial ports and then show them to combo box dialog. the program syntax is shown in listing program 1. privatevoid form1_shown(object sender, eventargs e) { // get com port available combobox9.items.clear(); foreach (string s inserialport.getportnames()) { combobox9.items.add(s);} combobox9.selectedindex = 0;} serial data communication is set to a baud rate of 9,600 bps, with 8 data bits, 1 stop bit, no parity, and no handshake. transfer data rate can be increased by changing the baud rate to a higher value than the default, such as 115,200 bps. the same serial port setting must be used by atmega128. atmega128 ic will not receive valid data if serial port settings are not the same. the program syntax is shown in listing program 2. serialport2.portname = combobox9.text; //get id comport com = combobox9.selectedindex; serialport2.baudrate = int.parse("9600"); serialport2.databits = int.parse("8"); serialport2.stopbits = (stopbits)enum.parse(typeof(stopbits), "one"); serialport2.parity = (parity)enum.parse(typeof(parity), "none"); serialport2.handshake = (handshake)enum.parse(typeof(handshake), "none"); serialport2.open(); figure 10. minimum system of motor driver board d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 71 a control command is sent to the main board in the form of data packet. data packet has header, id, function, data and tail as describe in previous section. the program syntax is shown in listing program 3. publicvoid speedm2() { char function = 'a'; //send to serial data if (main_form.serialport2.isopen){ doublenilai = convert.todouble(numericupdown2.value) * speed_kali; main_form.serialport2.write("@b" + function + convert.tostring(nilai) + "#"); speed2 = convert.tostring(numericupdown2.value);}} user interface consists of a start/stop button, a motor speed control form, a high dc voltage button, a video webcam form, and an automatic setting form. figure 11 show the display of the user interface. iv. experiment and analysis a. high dc voltage testing for high dc voltage were conducted by connecting port c.0-5 of the microcontroller to the input of the high dc voltage board and connecting adc channel0 (portf.0) of microcontroller atmega128 ic to the high dc voltage output via a voltage divider. adc readings show on lcd. electronics configuration is shown in figure 12. high dc voltage output is configured from pc interface software by clicking the high dc voltage button. measurements of high dc voltage output are taken three times and the results are shown in table 2. the high dc voltage output curves can figure 11. display of pc software interface figure 12. electronics setup for high dc voltage test d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 72 be seen in figure 13. the output y follow the voltage setting x, according to the formula y = 1x – 0.0224 and r 2 = 0.9998. this result shows that high dc voltage generator and pc interface software work as expected. b. polymer flow rate the control for polymer flow rate is done by configuring speed of motor stepper. testing for relation between motor speed and polymer flow rate were conducted by connecting motor driver to main board via i2c, the syringe with 10 ml volume, a timer to show minute as in figure 14. polymer flow rate is configured from pc interface software by clicking the motor speed control button. measurements are taken three times and the result is shown in table 3. the polymer flow rate curves are shown in figure 15. the polymer flow rate (ml/minute) y follows the motor speed (rpm) setting x, according to the formula y = 0.954x – 0.0099 and r 2 = 1. this result shows that motor driver work as expected. c. sem analysis a scanning electron microscope (sem) is used to analyze the nanofibers produced in this experiment. the results of sem for morphology analysis of pvdf copolymer composite nanofiber is shown in figure 16. the average diameter of the fibers is 136.43 nm, when the high dc voltage is set to 15 kv and the syringe pump speed is set to 5 rpm. there are some table 2. adc reading on high dc voltage output setting (kv) adc 1 (kv) adc 2 (kv) adc 3 (kv) 1,00 1,15 1,15 1,19 2,00 2,29 2,32 2,31 3,00 2,95 2,98 2,98 4,00 3,93 3,98 3,97 5,00 4,91 4,96 4,96 6,00 5,92 5,96 5,96 7,00 6,90 6,94 6,94 8,00 7,95 7,98 7,98 9,00 8,94 8,97 8,97 10,00 9,95 9,99 10,00 11,00 10,91 10,93 10,97 12,00 11,93 11,98 11,97 13,00 12,94 12,97 12,97 14,00 13,92 13,97 13,99 15,00 14,84 14,94 14,92 16,00 15,96 16,05 16,06 17,00 16,94 17,06 17,05 18,00 17,91 18,05 18,03 19,00 19,05 19,12 19,14 20,00 19,92 20,01 20,01 21,00 21,06 21,19 21,15 22,00 21,97 22,02 22,04 23,00 23,10 23,17 23,19 24,00 24,12 24,23 24,25 25,00 24,99 25,04 25,05 table 3. polymer flow rate (ml/minute) motor speed (rpm) m1 (ml/minute) m2 (ml/minute) m3 (ml/minute) 1,00 0,9466 0.9460 0.9466 2,00 1.8986 1.8966 1.8962 3,00 2.8426 2.8439 2.8420 4,00 3.8128 3.8220 3.8138 5,00 4.7594 4.7553 4.7576 figure 13. high dc voltage output curve figure 14. testing for polymer flow rate setup d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 73 processing parameters that can greatly affect the fiber formation and structure on electrospinning system. these parameters are high dc voltage, polymer flow rate, capillary-collector distance, polymer concentration, solution conductivity, and solvent volatility [4, 11-15]. a number of general relationships between processing parameters and fiber morphology are shown in table 4 [4]. v. conclusions pc interface software works as expected. high dc voltage output can be configured from pc interface software via serial communication. the maximum output of high dc voltage is 25.025 kv. the output y follows the voltage setting x, according to the formula y = 1x – 0.0224 and r2 = 0.9998. polymer flow rate can be configured from pc interface software via i2c connected to the main board. the flow rate y follows the rpm setting x, according to the formula y = 0.954x – 0.0099 and r 2 = 1. the results of scanning electron microscope (sem) for morphology analysis of pvdf copolymer composite nanofibers show that average diameter of produced fibers is 136.43 nm, when high dc voltage is set to 15 kv and syringe pump speed is set to 5 rpm. acknowledgement this work was fully funded by competitive program of indonesian institute of sciences, 2011-2013. references [1] fang jian, wang xungai and lin tong, “functional applications of electrospun nanofibers”, intech, china, 2011. [2] khan nishath, “applications of electrospun nanofibers in the biomedical field”, studies by undergraduate researchers at guelph, vol. 5, no. 2, pp. 63 73, winter 2012. [3] z. rozek, et al., “potential applications of nanofiber textile covered by carbon coatings”, journal of achievements in materials and manufacturing engineering, volume 27, no. 1, march, 2008. [4] travis j. sill and horst a. von recum, “electrospinning: applications in drug delivery and tissue engineering”, biomaterial, volume 29, issue 13, may 2008, pages 1989–2006 http://www.sciencedirect.com/science/artic le/pii/s0142961208000203, 2008. [5] hai-sheng wang, guo-dong fu, xin-song li., ”functional polymeric nanofibers figure 15. flow rate curve figure 16. the result of sem for pvdf copolymer composite and 15 kv high dc voltage table 4. effects of electrospinning parameters on fiber morphology[4] parameter effect on fiber morphology applied voltage ↑ fiber diameter ↓ initially, then ↑(not monotonic) flow rate ↑ fiber diameter ↑ (beaded morphologies occur if the flow rate is too high) distance between capillary and collector ↑ fiber diameter ↓ (beaded morphologies occur if the distance between the capillary and collector is too short) polymer concentration (viscosity) ↑ fiber diameter ↑ (within optimal range) solution conductivity ↑ fiber diameter ↓ (broad diameter distribution) solvent volatility ↑ fibers exhibit micro texture (pores on their surfaces, which increase surface area) y = 0,954x 0,009 r² = 1 0 1 2 3 4 5 0 2 4 6 f lo w r a te ( m l/ m in u te ) motor speed (rpm) m1 m2 m3 d. kurniawan et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 65-74 74 from electrospinning”, recent patents on nanotechnology, 3, 21-31, 2009. [6] ziabari m. v, et al.,”application of direct tracking method for measuring electrospun nanofiber diameter“, brazilian journal of chemical engineering, vol. 26, no. 01, pp. 53-62, january-march, 2009. [7] atmel corporation, 8 bit avr microcontroller with 128 kbyte in system programable flash, datasheet atmega128a, 2006. [8] rahman and muhammad muktadir, “variable hvdc supply using integrated high voltage transformer with several protective features to the output power bjt/ mosfet”, proceedings of the world congress on engineering and computer science 2011 vol i wcecs 2011, october 19-21, 2011, san francisco, usa. [9] fairchild semiconductor corporation, uc3842/uc3843/uc3844/uc3845 smps controller, datasheet uc3842, 2002. [10] allegro microsystems, bimos ii unipolar stepper motor translator/driver, datasheet uc5804b, 2000. [11] angammana, chitral j. and jayaram, shesha h., “analysis of the effects of solution conductivity on electrospinning process and fiber morphology”, ieee transactions on industry application, vol. 47, no. 3, may/june, 2011. [12] chowdhury , mohammad and stylios , george, “effect of experimental parameters on the morphology of electrospun nylon 6 fibres”, international journal of basic & applied sciences ijbas-ijens, vol.10, no.06, 2010. [13] rodoplu, didem and mehmet mutlu, ph.d, “effects of electrospinning setup and process parameters on nanofiber morphology intended for the modification of quartz crystal microbalance surfaces”, journal of engineered fibers and fabrics, vol. 7, no. 2, 2012. [14] zargham shamin, et al., “the effect of flow rate on morphology and deposition area of electrospun nylon 6 nanofiber”, journal of engineered fibers and fabrics, vol. 7, no. 4, 2012 [15] c. henriques, r. vidinha, d. botequim, j. p. borges, and j. a. m. c. silva, “a systematic study of solution and processing parameters on nanofiber morphology using a new electrospinning apparatus”, journal of nanoscience and nanotechnology, vol.8, pp. 1–11, 2008. mev mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.117-126 ombustion property analysis and control system for the dynamics of a single cylinder diesel engine bambang wahono a, *, wang xiaoli b , harutoshi ogai c a research centre for electrical power and mechatronics, indonesian institute of sciences, komp lipi jl cisitu 21/154d, gd 20, bandung 40135, indonesia b foster electric. co., ltd 512 miyazawa-cho, akishima city, tokyo, 196-8550, japan c graduate school of information, production and systems, waseda university 2-7 hibikino, wakamatsu-ku, kitakyushu, fukuoka 808-0135, japan received 21 october 2013; received in revised form 05 december 2013; accepted 06 december 2013 published online 24 december 2013 abstract corresponding to global environment problems in recent year, the technology for reducing fuel consumption and exhaust gas emission of engine was needed. simulation of transient engine response is needed to predict engine performance that frequently experience rapid changes of speed. the aim of this research is to develop a non-linear dynamic control model for direct injection single cylinder diesel engine which can simulate engine performance under transient conditions. in this paper, the combustion model with multistage injection and conducted experiments in the transient conditions to clarify the combustion characteristics was proposed. in order to perform the analysis of acceleration operation characteristics, it was built a model predictive control (mpc) to reproduce the characteristic values of the exhaust gas and fuel consumption from the control parameters in particular. finally, mpc is an effective method to perform the analysis of characteristic in diesel engine under transient conditions. key words: model predictive control (mpc), transient, diesel engine, disturbance, modeling. i. introduction the big problem in the diesel engine is the exhaust gas emission such as soot, nox, co and hc. these emissions are harmful not only for human being but also for environment. many approaches have been proposed to reduce these emissions [1]. in recent years, diesel engine has been equipped with some control devices such as multiple injection equipment with common rail system and turbocharger [2]. the diesel engine with direct injection (di) has established an effective method for improving the engine performance. simulation of transient diesel engine response is needed to forecast diesel engine performance including exhaust gas emissions and fuel consumptions that frequently experience rapid changes of speed. most of the research done in this field has concentrated on steady-state control models for the purpose of modifying engine control parameters in order to minimize exhaust gas emissions and fuel consumptions. however, recent regulations have enforced stringent emissions and fuel consumptions standards that cannot longer be addressed by a steady-state analysis of the diesel engine. to contribute towards solving this problem, the current research is focused with the aim of developing a non-linear dynamic control model for direct injection of single cylinder diesel engine which can simulate the engine performance under transient operating conditions. there are two major categories in diesel dynamics model i.e. steady-state non-linear dynamics, and non-linear transient models. the steady-state nonlinear dynamics model can be found in [3, 4, 5, 6], which simulate engines to estimate engine torque and cylinder pressure. in this paper, the research focused on the construction of engine control model with multistage injection in single cylinder diesel engine. exhaust gas prediction is more difficult *corresponding author. tel: +62 22 250 3055 e-mail: bambang.wahono@lipi.go.id http://dx.doi.org/10.14203/j.mev.2013.v4.117-126 b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 118 for diesel engine in ignition timing and diffuse combustion than in a gasoline engine. then, for carrying out the construction of the engine control model with multistage injection, it conducted experiments in the transient operating conditions to clarify the combustion characteristics. in order to perform the analysis of the acceleration operation characteristics, it was built a model predictive control (mpc) to reproduce the characteristic values of the exhaust gas and fuel consumption from the control parameters in particular. in order to more clearly, it proposed the comparison of disturbance insertion control with model predictive control and without model predictive control. finally, it will be evaluated the fuel consumption and exhaust characteristic improvement of the model control. ii. basic concepts of model predictive control predictive model control (mpc) is also called receding horizon control is an effective tool to handle limited multivariable control problem and has been widely used in industry [7, 8]. in the 1960s, the ideas of the model predictive control can be tracked back [9]. since the 1980s interest in this area began to increase after the publication of papers on idcom [10] and dynamic matrix control (dmc) [11, 12], and generalized predictive control (gpc) in the 1980s [13, 14]. although the ideas underlying the dmc and gpc are similar, dmc was contained in multivariable constrained control, while gpc is especially suitable for single variable and adaptive control. basic structure of model predictive control is illustrated in figure 1. the name mpc come from the idea of employing an explicit plant model to be controlled which is used to predict the future output behavior. this prediction capability allows solving optimal control problems on line, where tracking error, namely the difference between the predicted output and reference trajectory, is minimized over a future horizon input, possibly subject to constraints on the manipulated inputs and outputs. the underlying principle in every type model predictive control, among others: 1. using a process model to predict the future output within a predetermined time range (horizon). 2. calculate the control signals to minimize the objective function (criterion function) defined previously with the aim to keep the future output that is as close as possible to the reference trajectory. 3. control signals u(k|k) sent to the process, while the next predictable control signals discarded, because at the next sampling, the output y(k+1)is already known values. so the first step is repeated with the new value of new process output and all procedures necessary calculations repaired. the new control signal u(k+1|k+1)value is different from u(k+1|k), obtained by using the concept of receding horizon. the concept of receding horizon can be seen in figure2. iii. experiment of transient diesel engine a. the transient of a diesel engine since the diesel engine used in the transient state, in which the rotational speed and the load changes large, it is important to understand the characteristics of the transient operation very well. then, it will be tried to analyze each characteristic of the diesel engine in the transient operation. figure 1. basic structure of model predictive control figure 2. receding horizon strategy b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 119 b. transient experiment of diesel engine in this research, it will be done the experiment in transient operation based on the rotation of engine (rpm). the rotation of engine will be accelerated from 1,000 rpm to 2,000 rpm and slowdown until 1,000 rpm. the experiments with multiple injections are performed on a diesel engine experimental device (in figure 3) included exhaust measuring device and controller of single cylinder diesel engine (in figure 4) whose specifications are listed in table 1. in this research, it used the single cylinder diesel engine experimental device to get the experiment data. the experimental device of this research is yanmar tf70 v-e diesel engine with 4 cycle horizontal type water-cooling and equipped with a turbocharger (in figure 3). the explanation of optimization objectives is listed as table 2, and engine control parameters are set as table 3. based on experiment data, optimization objectives are formulated using stepwise method with multicollinearity. equation (1) shows a second-order model: i p 1i 2 iii p ji jiij p 1i ii0a exβxxβxββy    (1) where ya is the characteristic value of the optimization objective, a = 1, 2, 3, 4, β0is coefficient constant, βi is coefficient on the xi predictor, βij is coefficient on the xi predictor and xj predictor, βii is coefficient on the xi predictor second-order, p is the total number of predictors and ei is error term. iv. diesel engine modeling a. transient control with model predictive control corresponding to global environment problems in recent years and energy depletion problem, the technology of improving the fuel figure 3. single cylinder diesel engine experimental device figure 4. exhaust measuring device and controller of single cylinder diesel engine table 1. specification of the diesel engine parameter unit engine type 4-cycle, 1cylinder, di bore x stroke 78 mm x 80 mm top clearance 0.98 mm con-rod length 115 mm compression ratio 21.4 cylinder capacity 0.382l maximum output 5.5/2600 kw/min -1 full-length 640 mm full-height 474 mm full-width 330.5 mm table 2. optimization objectives optimization objective meaning unit y1 power kw y2 bsfc g/kwh y3 nox ppm y4 soot m -1 table 3. diesel engine control parameters control parameter meaning unit x1 pilot 1 injection timing deg. atdc x2 pilot 1 injection quantity mm 3 /st x3 pilot 2 injection timing deg. atdc x4 pilot 2 injection quantity mm 3 /st x5 main injection timing deg. atdc x6 main injection quantity mm 3 /st x7 injection pressure mpa x8 engine speed rpm b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 120 consumption and exhaust gas emission of an automobile engine is needed. if it compared with a gasoline engine, the diesel engine for cars has a high-thermal-efficiency and low co2. in other side, the amount of nox and soot is increased. although many electronic control devices, such as a common rail system, egr, and a turbocharger, are mounted on the present diesel engine, the fuel consumption and the exhaust gas emission require the technology which sets the control parameter of these devices and get the optimal value of control parameter. moreover, in order to realize the efficiency of engine control system, the engine control system development and engine appropriate technology of the model base is developed attract attention in recent years. one of the engine control system development is based on the prediction result of such a model. then, the attention in last years has been paid to engine and complete power train control using the knowledge of the models [15], [16]. model predictive control (mpc) is a group of algorithm of control computer that uses explicit process models to predict future responses of an application in which each control interval of a mpc algorithm tries to optimize future behavior by calculating a sequence of future adjustment of the manipulated variable. [17]. mpc meet the automotive requirements since this method can be expressed in the form of a constrained multi input multi output optimal control problem and provides an approximate solution of the problems [18]. in this research, it used the following equation to build a model predictive control. 1,...,4i δub....δubδubδubfaf 7i,73i,32i,21i,1 t ii 1t i    with fi is controlled variable, uj is control input (injection timing, injection quantity), and 𝑏𝑖,𝑗 = (𝜕𝑓𝑖 )/(𝜕𝑢𝑗 ) is influence coefficient (calculated from engine model). it adjusted the input u as control input (pilot 1 injection timing, pilot 1 injection quantity, pilot 2 injection timing, pilot 2 injection quantity, main injection timing and main injection quantity), which is a predictive control for match the set value from the observed value output (power, bsfc, nox, soot). b. derivative of the prediction model based on the previous study [19], the four optimization objectives evaluated using stepwise methods considering multicollinearity and it got the combustion model are as follows: y1: power (kwh) y1 = −1.2209 + 1.5953e −10−1 x6 +2.1274e−10 −3 x6x8 + 6.7681e 10−6 x7x8 − 707904e10 −7 x8 2 (2) y2: bsfc (g/kwh) y2 = 3.7745e 10 − 5.7032e10 x5 +4.9796e10 −2 x5 x8 + 1.1326e 10 x6x7 − 5.8178e10 −1 x6 x8 − 7.1307e 10−2 x7 2 + 3.2240e10 −4 x8 2 (3) y3: nox (ppm) y3 = 2.4205e 103 + 1.7414e10 2 x6 − 1.8747x8 + 3.6476e10 −2 x3 2 − 3.9282e10 x6 x7 + 1.586x6x8 + 1.6560e 10−1 x7 2 + 2.9429e10 −3 x7 x8 (4) y4: soot (m -1 ) y4 = −4.3300 + 5.0931e 10 x2+2.0626e 10−3 x1 + 1.1329x1x2 + 3.8892e 10−4 x1 x3 + 2.5323e10 −3 x2 x3 − 2.9668e 10−4 x3 2 (5) in order to bring an evaluation value close to a desired value, the influence coefficient is calculated. to get value of the influence coefficient, the combustion model has to be derived. the derivative from these combustion models are as follow: y1: power (kwh) y x6 = 1.5953e −1 + 2.1274e−3x8 y x7 = 6.7681e −6x8 y x8 = 6.768e −6x7 − 707904e −72x8 y2: bsfc (g/kwh) y x5 = −5.7032e 1 + 4.9796e−2x8 y x6 = 1.1326e 1x7 − 5.8178e −1x8 y x7 = 1.1326e 1x6 − 7.1307e −22x7 y x8 = 4.9796e −2x5 − 5.8178e −1 x6 + 3.2240𝑒−42x8 y3: nox (ppm) y x3 = 3.6476e −22x3 y x6 = 1.7414e 2 − 3.9282e1x7 + 1.586x8 y x7 = −3.9282e 1x6 + 1.6560e −12x7 + 2.9429𝑒−3x8 y x8 = −1.8747 + 1.586x6 + 2.9429𝑒 3x7 y4: soot (m-1) y x1 = 2.0626e −3 + 1.1329x2+3.8892e −4 x3 y x2 = 5.0931e 1 + 1.1329x1+2.5323e −3x3 y x3 = 3.8892e −4x2 + 2.5323e −3 x2 + 2.9668e−42x3 the coefficient in these four differentiation type is used for control calculation of the diesel engine transient control simulation by matlab/simulink. b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 121 v. model implementation a. transient control simulation model in this section, it used the formula of predictive control model described in section iii, the deviation from the optimal value, which is calculated with basis error of prediction model and disturbance to make a transient control simulation model in matlab / simulink. figure 5 shows transient control simulation model of the single-cylinder diesel engine by simulink. the main advantage of the simulink module is its ability to represent the whole engine model with a set of interconnected blocks. input design parameters are passed on to the blocks from the input file, but all of the operating parameters derived from the block (functions) for the other components of the system. the control simulation of the model prediction control by the regression model of combustion was constituted. a right block is an engine revolution combustion model, and a left block is a control model. in this research, it use the model prediction control to understand the engine characteristic by change the rotation of engine from 1,000 rpm to 2,000 rpm and 2,000 rpm to 1,000 rpm. in a control model, the relation between eight control inputs and four controlled variables is used as an influence coefficient. the result is based on the engine rotations from 1,000 rpm, 1,500 rpm, and 2,000 rpm shown below. four variables were chosen from this result as a control input i.e. pilot 1 injection quantity, pilot 2 injection timing, main injection timing, and main injection quantity. influence coefficient ne=1000 pr = 1.0e+003 * 0 0 0 0 0 0.0023 0 0 0 0 0 0 −0.0072 0.5508 −0.0046 −0.0001 0 0 −0.0026 0 0 −2.1680 −3.3029 −0.0002 0 −0.0170 0 0 0 0 0 0 ne=1500 pr = 1.0e+003 * 0 0 0 0 0 0.0034 0 0 0 0 0 0 0.0177 0.2599 −0.0046 0.0002 0 0 −0.0026 0 0 −1.3750 −3.3014 −0.0002 0 −0.0170 0 0 0 0 0 0 ne=2000 pr = 1.0e+003 * 0 0 0 0 0 0.0044 0 0 0 0 0 0 0.0426 −0.0310 −0.0046 0.0005 0 0 −0.0026 0 0 −0.5820 −3.2999 −0.0002 0 −0.0170 0 0 0 0 0 0 the impact on output from injection quantity of pilot 1, the injection timing of pilot 2, the main injection timing and the main injection quantity should be inserted into matrix 4 × 4 then inverse of matrix multiplied control amount of deviation that it was looking for. this is an example of a matrix of 4 × 4: figure 5. the transient control simulation model by simulink b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 122 0 0 0 0.0023 0 0 −0.0072 0.5508 0 −0.0026 0 −2.1680 −0.0170 0 0 0 b. result of model predictive control first of all, 4 optimal values (power, bsfc, nox, soot) of engine rotation 1,000 rpm are set as target value, then changes in the characteristics of the rotation of engine from 1,000 rpm to 2,000 rpm and 2,000 rpm to 1,000 rpm is shown in the figure 6-10. in order to show the sufficient performance of a predictive model, it compared the model which has controlled and hasn‟t controlled. in figure 6, it can be seen control input when carrying out model predictive control has many variations value such as pilot 1 injection quantity (0.1900 to 0.1844 mm 3 /st), pilot 2 injection timing (-25.7 to -24.8 deg. atdc), main injection timing (-4.74 to -4.69 deg. atdc), and main injection quantity (0.98 to 1.08 mm 3 /st). if it compared with model which hasn‟t controlled, the all control input has stabile. it can be seen the control input of model without controlled in figure 8. the result of controlled variable from the experiment with transient control based on the engine rotations from 1,000 rpm to 2,000 rpm and 2,000 rpm to 1,000 rpm shown below. the controlled variable with model predictive control has variation value better than controlled variable without model predictive control especially in value of soot. i can be seen the detail value of controlled variable with model predictive control in figure 7 i.e. engine power (1.05 to 1.8 kw), bsfc (225 to 370 g/kwh), nox (279 to 308 ppm) and soot (0.092 to 0.094 m -1 ) and controlled variable without model predictive control in figure 9 i.e. engine power (0.94 to 1.41 kw), bsfc (225 to 390 g/kwh), nox (364 to 375 ppm) and soot (0.1 m -1 ). in this result it can be seen that value of soot without model predictive control stable 0.1 m -1 . judging from the transient control input changes suggested by (pilot 1 injection quantity, pilot 2 injection timing, main injection timing, main injection quantity) as well as the controlled variable (power, bsfc, nox, soot), control performance can be known. in order to more clearly, it proposed the comparison of disturbance insertion control with model predictive control and without model predictive control in figure 10. in figure 10(a), the value of soot and nox is stable. this means that with a given disturbance insertion control does not change significantly. it seems different on models with mpc. from this explanation, experiment in transient operation based on the rotation of engine from 1,000 rpm to 2,000 rpm and slowdown until 1,000 rpm has been improved by model prediction control, and validity was shown. (a) (b) (c) (d) figure 6. control input with model predictive control; (a) pilot 1 injection quantity; (b) pilot 2 injection timing; (c) main injection timing; (d) main injection quantity b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 123 (a) (b) (c) (d) (e) figure 7. controlled variable with model predictive control; (a) engine speed; (b) engine power; (c) bsfc; (d) nox; (e) soot (a) (b) (c) (d) figure 8. control input without model predictive control; (a) pilot 1 injection quantity; (b) pilot 2 injection timing; (c) main injection timing; (d) main injection quantity b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 124 (a) (b) (c) (d) (e) figure 9. controlled variable without model predictive control; (a) engine speed; (b) engine power; (c) bsfc; (d) nox; (e) soot (a) b. figure 10. comparison of disturbance insertion control with mpc and without mpc; (a) disturbance insertion control in nox and soot without model predictive control; (b) disturbance insertion control in nox and soot with model predictive control b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 125 vi. conclusion steady-state analysis of the engine is insufficient to meet that the latest regulations imposed one missions and fuel economy. the research described in this paper has dealt with the dynamic model for a single cylinder diesel engine which can simulate the engine performance under transient operating conditions. this model is developed with investigating experiment in transient operation based on the rotation of engine from 1,000 rpm to 2,000 rpm and slowdown until 1,000 rpm. the major conclusions of this work are:  the transient engine simulation has been improved by model prediction control.  the results illustrate the important of single cylinder diesel engine simulation as nonlinear dynamic control system. in the future, by improving the control model, it would be like to improve the model closer to the target value for the output more transient. acknowledgement i would like to thank to ogai laboratory members, especially zong lu and yuga for their suggestions. i‟d also like to recognize imam sutrisno and muhammad abu jami'in for their contributions. references [1] p.k. karra, s.c. kong, “diesel engine emissions reduction using particle swarm optimization”, combustion science and technology, 182:7, taylor and francis, pp. 879–903. [2] z. lu, m. ogawa h. ogai, “response surface modeling of multiple injection diesel engine”, the 54th conference of the automatic control federation, toyohashi university of technology, november 19-20, 2011. [3] rizzoni, g., “estimate of indicated torque from crankshaft speed fluctuations: a model for the dynamic of the ic engine”, ieee trans. vehicular technology, vol.38, issue: 3, 168-179. [4] rizzoni, g. and zhang, y., “identification of a non-„linear internal combustion engine model for on-u ne indicated torque estimation”, mechanical systems and signal processing, 8, 275-287. [5] lida, k. et al., “imep estimation from instantaneous crankshaft torque variation”, sae technical paper no. 900617. [6] zhang. , y. and rizzoni, g., “an on-line indicated torque estimator for ic engine diagnosis and control”, asme j. advanced automotive tech, 52,147162. [7] lee, j.h. and b. cooley (1997). recent advances in model predictive control. in: chemical process control v. vol. 93, no. 316. pp. 201-216b. aiche symposium series american institute of chemical engineers. [8] qin, s.j. and t.a. badgewell (1997). an overview of industrial model predictive control technology. in: chemical process control v. vol. 93, no. 316. pp. 232-256. aiche symposium series american institute of chemical engineers. [9] garcia, c.e., d.m. prett and m. morari (1989). model predictive control: theory and practice – a survey. automatica. [10] richalet, j. et al., model predictive heuristic control: applications to industrial processes. automatica 14(5), 413-428, 1978. [11] cutler, c. r. and b. l. ramaker. dynamic matrix control a computer control algorithm. in: aiche 86th national meeting. houston, tx, 1979. [12] cutler, c. r. and b. l. ramaker (1980). dynamic matrix control a computercontrol algorithm. in: joint automatic control conf.. san francisco, california. [13] clarke, d. w., c. mohtadi and p. s. tuffs. generalized predictive controli. the basic algorithm. automatica 23, 137-148, 1987. [14] clarke, d. w., c. mohtadi and p. s. tuffs. generalized predictive control-ii. extensions and interpretations. automatica 23, 149-160, 1987. [15] pischinger, s. et al., investigation of predictive models for application in engine cold-start behaviour, sae paper 2004 010994. [16] winsel, t. et al., hil-calibration of si engine cold start and warm-up using neural real-time model, sae paper 200401-1362. [17] qin, s. j. and t. a. badgwell. "a survey of industrial model predictive control technology." control engineering practice 11(7): 733-764, 2003. [18] l. del re et al. (eds.), automotive model predictive control, lncis 402, pp. 1–22. springer-verlag berlin heidelberg, 2010. b. wahono et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 117-126 126 [19] wahono, b., ogai, h., construction of response surface model for diesel engine using stepwise method, the 6th international conference on soft computing and intelligent systems and the 13th international symposium on advanced intelligent systems, november 20-24, 2012, kobe, japan. mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.37-44 distributed control system design for portable pc based cnc machine roni permana saputra a,b, *, tinton dwi atmaja a , budi prawara a a research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi jl. sangkuriang, gd. 20, lt 2, bandung, west java, 40135 indonesia b school of mechanical and manufacturing engineering, the university of new south wales library rd, kensington nsw 2033 australia received 28 march 2013; received in revised form 05 june 2014; accepted 06 june 2014 published online 23 july 2014 abstract the demand on automated machining has been increased and emerges improvement research to achieve many goals such as portability, low cost manufacturability, interoperability, and simplicity in machine usage. these improvements are conducted without ignoring the performance analysis and usability evaluation. this research has designed a distributed control system in purpose to control a portable cnc machine. the design consists of main processing unit, secondary processing unit, motor control, and motor driver. a preliminary simulation has been conducted for performance analysis including linear accuracy and circular accuracy. the results achieved in the simulation provide linear accuracy up to 2 μm with total cost for the whole processing unit is up to 5 million idr. keywords: distributed control, portable cnc machine, linear interpolation, circular interpolation. i. introduction recently, the demand on automated machining has increased remarkably in the industrial world. at present decade, some fields such as the electronic, automotive, and medical have incorporated applications requiring microproducts [1]. this research purpose is to solve this current status based on other current research which focused on research and development of micro-machines and low cost pc based cnc system. research and development of micromachines for different applications is widely available, mainly at academic and experimental level [2]. a general discussion on micromachining with emphasis in the selection of the cutting parameters and the vibrations can be found. it is emphasized that for micro-turning, diamond tools, as well as micro-tools shaped through the focused ion beam (fib) sputtering technique are the usual choice, thus achieving results ranging from 15 to 100 microns and edge radii of 40 nanometers. in [2] we can find the development of a cnc micro-lathe for bone micro implants. micro turning with the cnc micro-lathe has been proved as a method for the fabrication of bone micro implants with controlled geometries. other research on cnc system was conducted by yamanaka et al. [3], weidong et al. [4], atmaja et al. [5], [6], and permana et al. [7]. research in the pc-based cnc is so much. in james et al [8], the authors developed pc-based low-cost cnc automation of plasma profile cutting of pipe. they developed cnc pipe profile cutting machine which has the capability of producing high precision parts by simultaneous control of only two axes. in surya et al. [9], a discussion on pc-based open architecture servo controller for cnc machining can be found. this system is modular with greater flexibility with the choice of its components. in zhiming et al. [10], it can be found the development of pcbased adaptive cnc control system. the new concept of integrating cnc control systems with adaptive feedback control for intelligent material processing has been explored. in onwubolu et al. * corresponding author. tel: +62-22-2503055 e-mail: permana.saputra@yahoo.co.id http://dx.doi.org/10.14203/j.mev.2014.v5.37-44 r. p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 38 [11], development of a pc-based computer numerical control drilling machine can be found. on the other hand, distributed architecture development for control system started to emerge many advantages e.g. open architecture, dynamic ability, fast mobility, and high flexibility. moreover, distributed system provides simplicity on the extension and configuration by adding and removing certain module [12]. the distributed system contains of structured devices having respective function which can exchange their function with each other. one of the important advantages on this distributed system is that the exchange method between structured devices is done via communication appliance [13]. the examples of popular distributed control system implementation are on the complex manufacturing production control and the centralized factory control system [14]. ii. methods methodology used in this research involved three steps. firstly, literature studies concerning cnc machine. secondly, machine elements selection and integration to realize a portable cnc machine having a distributed control system. thirdly is development of control algorithm through computer simulation. the cnc machine is controlled by an operator by means of a portable computer using designated user interface. in order to disseminate the resulted technology to small and medium enterprises, special consideration has been put to emerge a low cost system. the cnc machine has two axis motors and one spindle motor. it is equipped with one working table for holding the work piece. stepper motors of the type of 4-phase unipolar were used for axis motors. the maximum rotation speed attainable is 300 rpm and the detent torque is 3.5 nm. the displacement of the xy table is produced by a helical rack and pinion mechanism in each axis. thus the rotational motion applied to the pinion by a reduction system and the stepper motor will cause the rack to move to the side, up to the limit of its travel. the pitch diameter in these pinions varies depending on the axis, for the x-axis the pitch diameter of the pinion is 13.5 mm and for the y-axis is 6.5 mm. for the purpose of this research the displacement resolution per step was 1μm in each axis. this research focuses on design and analyzing of a control system for portable cnc machine based on pc using distributed control method. iii. distributed control system design the distributed control system block diagram proposed in this research is shown in figure 1. it consists of a primary processing unit, secondary processing unit, motor controllers, motor drivers and feedback sensors. secondary processing unit / supervisory control unit using microcontroller motor control unit (speed & position control) motor control unit (speed & position control) motor control unit (speed & position control) driver motor unit driver motor unit driver motor unit motor actuator 1 motor actuator 2 motor actuator 3 s e ri a l c o m m u n ic a ti o n using usb to serial device portable computer for user interface and main processing unit feed back sensor feed back sensor feed back sensor f e e d b a c k s ig n a l f e e d b a c k s ig n a l f e e d b a c k s ig n a l figure 1. distributed control system design r.p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 39 the primary processing unit was designed to receive, process, and interpret the input geometry data. the input was given to the software in the form of machine g-code according to the iso841 standard. in this research, not all functionalities of the g-code were used, and only the very basic features were implemented. interpolation was processed in a software application, which receives the geometric information input in the form of machine g-code and then converts it into 8-bit words that will be interpreted by the microcontroller. these words contain information such as motor to be actuated, sense of motion, or stepping sequence. the secondary processing unit was designed to facilitate the microprocessor embedded to the system. for the purpose of this research, motion control of the machine tool was done following a cnc-like approach. therefore, the use of a microcontroller unit was required to interpret the software output and convert it into registries that will actuate the stepper motors. the basic functions of the microcontroller in this project can be summarized as receive input data, write random access memory (ram), read ram, interpret instruction and actuate motors. a. main processing unit the overall of the main processing unit is in the form of a portable computer. it is used to facilitate portability of the control module and simplify the dimension of the control system. this unit processes the data inputted by the operator via the designated user interface. input data is in the form of g-code and m-code including a value data representing the geometric coordinate for the end effectors geometric movement. mainly, there are two kinds of geometric movement i.e. linear and circular movement. coordinate calculation for linear trajectory is called linear interpolation while the coordinate calculation for circular trajectory is called circular interpolation. article [7] shows the calculation method for linear interpolation and circular interpolation. this paper proposes a design of main processing unit algorithm which consists of a distributed control system algorithm and a user interface for the operator whose flowcharts are shown in figure 2 and figure 3, respectively. b. secondary processing unit this unit is the second part of the distributed control system. it translates the geometrical data sent from the main processing unit into control algorithm producing control signal for the mechanical servo. this unit consists of supervisory control module and motor control module. the supervisory control module is to process the reference data from the main processing unit and to produce reference data for each motor control module. the motor control module is to control each motor actuator over servo mechanism. 1. supervisory control module the supervisory control module in this system was designed to communicate with the main processing unit using serial communication port. it reads reference data sent by the computer. the received data is in the form of velocity data and position data for all motor actuators. the data begin input g-code data by operator save data in acumulator read 1 row data from accumulator interpretation data : 1. function (g-code / m-code) 2. value (geometrical value) linear interpolation circular interpolation other functions send data to secondary processing unit (start/stop; run/brake; ω 1-n; θ 1-n) end figure 2. flowchart of the software for the main processing unit figure 3. user interface design for the main processing unit r. p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 40 is then distributed to all control motor sequentially from control motor 1 until control motor n. this data will be used as the main reference by unit control motor. this unit contains software and hardware. the hardware usually microcontroller system equipped with embedded software. microcontroller atmega128 was used because it has many i/o port so it can distribute many data to many control unit module [15]. i/o port in this microcontroller system is divided into several parts i.e. port common speed data reference, common position data reference, header control identifier, verification data identifier, external data input unit, and external control unit. figure 4 shows the system schematic of atmega128 as the supervisory control module. to execute its function, it was equipped with embedded software using flowchart shown in figure 5. 2. motor controller module the motor controller module in this system serves as the motor actuator movement controller either for the axis motor actuator or for the spindle motor actuator. this unit controls velocity and angle of motor rotation. this unit consists of hardware in the form of a microcontroller chip with embedded software. this system use atmega16 as the main component of the module. atmega16 microcontroller module was selected because it has 32 i/o ports with the process speed up to 1 µs per working cycle [16]. moreover, economical aspect and availability in the domestic market are included in the main consideration [17]. i/o port in this module was divided into several parts i.e. position data reference, speed data reference, spv communication, motor control digital signal, and feedback control signal. figure 6 shows schematic system design of the motor control module. as in the supervisory control module, the motor control module has also been equipped with embedded software. this module receives data distribution from the supervisory control module in the form of velocity reference and position reference. after receiving the data, this module will send back a feedback signal to the supervisory control module. the received data will be used as the reference on controlling the motor actuator. this module produces digital figure 4. system schematic of the supervisory control module using atmega128 begin read refference data from supervisory control unit (ω 1~n ; θ 1~n) transmit data to motor control unit 1 n save actual data in accumulator yes no has data transmit from main processing unit? innitial data end figure 5. flowchart of the software for the secondary processing unit r.p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 41 signal to the motor driver to drive the motor to designated trajectory with designated velocity according to the received reference. furthermore, this module observes the actual condition corresponds to the feedback signal from the sensor. the received feedback signal will be compensated back to the calculation of the motor control module. flowchart of the software for the motor controller module is shown in figure 7. c. servo mechanism unit the servo mechanism unit is the physical part of the cnc machine which actuates all the orders received from the control system and also generates the status of the machine [7]. this part consists of motor actuator with motor driver and feedback sensor giving the actual information of position and velocity of the end effectors. the designated motor actuator can be dc motor, stepper motor, brushless dc motor, ac motor, etc. this motor must be equipped with a driver unit suitable with the motor type. figure 8 shows the example of the motor driver actuator equipped with a driver [18]. feedback sensor used in this system was a rotary encoder which acts as position and velocity sensor. rotary encoder was used to measure rotary position. the number of the pulse sent by the rotary encoder can be counted as the number of the steps taken by the motor actuator so the position and the direction can be controlled. figure 9 shows incremental type and absolute type of rotary encoder which can be used as feedback sensor [19] [20]. iv. result and discussion the technical prototype of this distributed control system is shown in figure 10. figure 10(a) shows user interface used in main processing unit while figure 10(b) shows the secondary processing unit and figure 10(c) shows complete integrated prototype of the distributed control system on cnc lathe machine. figure 6. system schematic design of the motor control module using atmega16 microcontroller begin read refference data from supervisory control unit (ω ; θ) refference = actual read actual data from feedback sensor send signal to driver unit to running motor actuator save actual data in accumulator save actual data in accumulator end yes no figure 7. flowchart of the software for the motor controller module figure 8. motor driver actuator figure 9. incremental type and absolute type of rotary encoder [19] [20] r. p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 42 some preliminary tests were conducted to observe the performance of each component of the designated distributed control system, including main processing unit, secondary processing unit and the communication between each other. the testing was done by inputting one g-code instruction set to the user interface in main processing unit and then generate numerical path for the instruction set. the testing analysis consists of three interpolation processes. first is performance calculation for linear interpolation, second is calculation for circular interpolation using g-02 instruction with clockwise characteristic, and the third is calculation for circular interpolation using g-03 instruction with counterclockwise characteristic. further calculation will consider the combination of them. the interpolation result from the main processing unit was then simulated using numerical programming software to generate the actual curve and the planned curve. this simulation was performed on 1 μm movement resolution for x axis and y axis. figure 11 shows the simulation of linear interpolation from the main processing unit which was designed using quasi continuous movement with the calculation explained in [7].the set instruction for figure 11 was: g01 x0000 y0000 g01 x1000 y2000 where the unit is at μm. the same method was used for circular interpolation simulation shown in figure 12 at clockwise direction and figure 13 at counterclockwise direction. the set instruction (a) (b) (c) figure 10. processing unit as the control system of the prototype; (a) main processing unit; (b) secondary processing unit; (c) complete prototype of the distributed control system on cnc lathe machine (a) (b) figure 11. simulation of g-code interpretation process by the main processing unit for linear interpolation; (a) simulation result on 100 μm scale (0.1 mm); (b) simulation result on 2 μm scale (a) (b) figure 12. simulation of g-code interpretation process by the main processing unit for counterclockwise circular interpolation; (a) simulation result on 100 μm scale (0.1 mm); (b) simulation result on 2 μm scale 0 500 1000 1500 2000 2500 0 200 400 600 800 1000 1200 y -a x is ( μ m ) x-axis (μm) result planning 0 5 10 15 20 25 30 35 40 45 0 5 10 15 20 y -a x is ( μ m ) x-axis (μm) result planning 0 100 200 300 400 500 600 0 100 200 300 400 500 600 y -a x is ( μ m ) x-axis (μm) result planning 0 2 4 6 8 10 12 0 20 40 60 80 100 y -a x is ( μ m ) x-axis (μm) result planning r.p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 43 for counterclockwise circular interpolation shown in figure 12 was: g00 x000 y000 g02 x500 y500 i000 j500 while the set instruction for clockwise circular interpolation shown in figure 13 was: g00 x000 y000 g03 x500 y500 i500 j000 from the description from figure 11 to figure 13, it can be seen that the algorithm designed for the main processing unit can perform the task as per requested. figure 11(a), 12(a), and 13(a) show that on 0.1 mm scale, the resulted interpolation path looks smooth and coincides with the planned path. figure 11(b), 12(b), and 13(b) show the actual interpolation path compared to the planned pathon reduced scale up to 2 μm. it is proved that this design has advantages from its technical aspect. while on the economical aspect, the software can be selfdeveloped and the only cost emerged is on the portable pc as the main processing unit and the electronic hardware for secondary processing unit. table 1 shows the price list and the availability of the processing unit for two axes. it shows that the hardware cost is low and the availability is high even in domestic market. overall, the cost of the whole processing system is approximately 5 million idr. v. conclusions according to these research results, it could be concluded that the designed distributed control system is applicable on the pc based cnc machine and can be considered as a low cost system. distributed control system enables high flexibility and openness to adapt with more complex developed system. the system can vary the number of the axis by just simply installing the additional unit motor controller, driver, motor actuator, and sensor feedback corresponds to the number of the axis. in this paper, the case shows a distributed system for two axes cnc machine. this proposed system also presents advantages in economical aspect. the economic analysis shows that this design is considered low cost and its component has a high availability in domestic market. further economic analysis should consider the mechanical unit on cnc machine whether it was lathe, milling, etc. further research is needed to improve the accuracy in more precision mechanism such as in nano scale. acknowledgement the authors would like to thank indonesia toray science foundation (itsf) for the research grant and to research centre for electrical power and mechatronics (lipi) for the support and the devices on the completion of this portable cnc research. the authors would also like to all parties correspond to the completion of this research. (a) (b) figure 13. simulation of g-code interpretation process by the main processing unit for clockwise circular interpolation; (a) simulation result on 100 μm scale (0.1 mm); (b) simulation result on 2 μm scale table 1. component price list and availability component price availability 1 main processing hardware (pc) 3.000.000 idr available in domestic market 2 main processing software n/a can be self-developed 3 secondary processing hardware 2.000.000 idr available in domestic market 4 secondary processing software n/a can be self-developed 0 100 200 300 400 500 600 0 100 200 300 400 500 600 y -a x is ( μ m ) x-axis (μm) result planning 0 20 40 60 80 100 120 0 2 4 6 8 10 12 y -a x is ( μ m ) x-axis (μm) result planning r. p. saputra et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 37-44 44 references [1] t. masuzawa, "state of the art of micromachining," annals of the clrp, vol. 49, no. 2, pp. 473-488, 2000. [2] d. a.. rangel, et al., "development of a cnc micro-lathe for bone microimplants," escuela de ingeniería de antioquia, no. 15, pp. 113-127, juli 2011. [3] m. yamanaka; et al. , "evaluation of size effect on micro-machine-tools design for microfactory," in proceedings of the 35th international matador conference, london: springer, 2007, pp. 301-304. [4] w. d. yang and j. chang, "an open cnc system based on motion controller," applied mechanics and materials, vol. 44 47, pp. 956-959, december 2010. [5] t.d. atmaja and a. muharam, "open source software implementation at three axis table control algorithm for three dimensional scanner mechanism," in proceeding of national seminar of open source software iii, bandung, november 2009, pp. b31-b36. [6] d.g. subagio and t.d. atmaja, "the use of open source software for open architecture system on cnc milling machine ," journal of mechatronics, electrical power and vehicular technology, vol. 2, no. 2, pp. 105-112, december 2011. [7] r. p. saputra, et al., "desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine," journal of mechatronics, electrical power and vehicular technology, vol. 2, no. 1, pp. 41-50, july 2011. [8] n. james, et al. , "pc-based low-cost cnc automation of plasma profile cutting of pipes," arpn journal of engineering and applied sciences, vol. 2, no. 5, 2007. [9] s. kommareddy, et al., pc-based oper architecture servo controllers for cnc machining. [10] g. zhiming, "development of pc-based adaptive cnc control system," automated material processing group, automation technology division, simtech technical report (at/01/043/amp) 2001. [11] g. c. onwubolu, "development of a pcbased computer numerical control drilling machine," journal of engineering manufacture , vol. 21, no. 6, p. 1509, 2002. [12] a. a. loukianov, et al., "implementing distributed control system for intelligent mobile robot," in the 8th international symposium on artificial life and robotics, oita, japan, january 2003, pp. 24–26. [13] l. cauffriez, et al., "design of intelligent distributed control systems: a dependability point of view," reliability engineering and system safety, vol. 84, pp. 19-32, 2004. [14] d. trentesaux, "distributed control of production systems," engineering applications of artificial intelligence , vol. 22, pp. 971–978, (2009). [15] atmel, "8-bit microcontroller with 128k bytes in-system programmable flash (atmega128/128l)," atmel, datasheet rev. 2467x–avr–06/11, 2011. [16] atmel, "8-bit microcontroller with 16k bytes in-system programmable flash (atmega16/16l)," atmel, datasheet rev. 2466t–avr–07/10, 2010. [17] digi-ware. (2013, feb.) digiware unlimited innovations. [online]. http://digiware.com [18] oriental motor. (2013, feb.) oriental motor website. [online]. http://catalog.orientalmotor.com [19] alibaba corp. (2013, feb.) alibaba website. [online]. maxwelleletric.en.alibaba.com [20] amci corp. (2013, feb.) amci advanced micro controls inc. [online]. http://amci.com/rotary-encoders/nr25profibus-dp-absolute-multi-turn-rotaryencoder.asp [21] atmel. (2010, july) atmel website. [online]. http://www.atmel.com mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 05, issue 1, july 2014 aim and scope mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal providing authoritative source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, tubine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev journal vision is to become international platform with high scientific contribution for global community. mev journal mission is presenting important results of work, whether in the form of research, development, application, or design. editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h1034, hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia za@dynamic.pauir.itb.ac.id prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2 nd fl, bandung 40135, ndonesia budi.prawara@lipi.go.id mailto:patko@uni-obuda.hu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 05, issue 1, july 2014 imprint journal of mechatronics, electrical power, and vehicular technology (mev) is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). mev journal is managed to be issued twice in every volume. issn print edition: 2087-3379 issn electronics edition: 2088-6985 electronics edition is available at: www.mevjournal.com accreditation accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 mev has been certificated as a national scientific journal by indonesian institute of sciences (lipi) by 24 april 2012. valid thru: 24 april 2015 indexing & abstracting indexed in ebscohost, index copernicus, directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), indonesian publication index (ipi), crossref, mendeley, citeulike, cite factor, academic journal database, and researchbib. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2 nd floor bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 managing editors aam muharam, m.t. electrical engineering aam.muharam@lipi.go.id dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com layout editors arief a firdaus, s.i.kom. communication science rif212@yahoo.com bambang wahono, m.eng. mechanical engineering bambangwahono80@yahoo.co.id midriem mirdanies, m.t. computer engineering midr001@lipi.go.id secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com vita susanti, s.kom. computer science vitasusanti@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com section editors amin, m.t. electrical engineering amin_hwi@yahoo.co.id arini wresta, m.eng. chemical engineering awresta@gmail.com dian andriani, m.eng. bioenergy engineering dea1401@yahoo.com ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com hendri m saputra, m.t. robotics and mechatronics hendri_maja@yahoo.co.id naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com rakhmad i pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id graphic designer m redho kurnia, s.sn. graphic design muha058@lipi.go.id http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 © 2014 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 05, issue 1, july 2014 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has been accreditated by the indonesian institute of sciences (lipi) in april 2012. it started using open journal system (ojs) since the online publishing of the third volume released in july 2012. this journal has been indexed by ebscohost, index copernicus, directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), indonesian publication index (ipi), crossref, mendeley, citeulike, cite factor, academic journal database, and researchbib. in addition, it has been granted digital object identifier with the doi prefix 10.14203. this issue publishes eight papers, all are written in english, with the total number of paper pages of 66 pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. three topics are related to mechatronics, three topics to electrical power and two topics to vehicular technology. most of the papers reflect one of the characteristics of this journal i.e. interdisciplinary. the policy up to this current issue is that both authors and readers are not charged at all. on the other hand, the editorial board is planning to improve the quality by registering the journal to other international academic citation index. moreover, the editorial board is also considering to gradually increase the number of papers and journal’s pages. all of this plan will give consequence on financial burden. therefore, from the next issue,financial policy will probably change based on that condition. we wish to offer our thanks to all the editorial members and the research centre for electrical power and mechatronics (rc-epm) – indonesian institute of sciences (lipi) for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2014 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 05, issue 1, july 2014 list of contents rotor-dynamic characteristic evaluation of interior permanent magnet motor using finite element method hilman syaeful alam, pudji irasari 1-8 experimental investigation of 2nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine yanuandri putrasari, haznan abimanyu, achmad praptijanto, arifin nur, yan irawan, sabar pangihutan simanungkalit 9-16 design and implementation of a magnetic levitation system controller using global sliding mode control rudi uswarman, adha iman cahyadi, oyas wahyunggoro 17-26 a trajectory generation method based on edge detection for auto-sealant cartesian robot eka samsul maarif, endra pitowarno, rusminto tjatur widodo 27-36 distributed control system design for low cost pc base cnc machine roni permana saputra, tinton dwi atmaja, budi prawara 37-44 cfd and wind tunnel analysis for mounted-wind turbine in a tall building for power generation dany perwita sari, kang-pyo cho 45-50 techno-economic analysis of biogas utilization as an alternative fuel merry indahsari devi, kristian ismail, arifin nur 51-58 the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation rizqon fajar, hari setiapraja 59-66 further articles can be found at www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 05, issue 1, july 2014 abstracts sheet e-issn: 2088-6985 date of issues: 23 july 2014 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. hilman syaeful alam a , pudji irasari b ( a technical implementation unit for instrumentation development, indonesian institute of sciences, bandung, indonesia; b research centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia) rotor-dynamic characteristic evaluation of interior permanent magnet motor using finite element method mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 1-8, 9 ill, 1 tab, 17 ref. dynamic characteristics of a critical speed of the rotor components at interior permanent magnet motor were evaluated using onedimensional (1d) and three-dimensional (3d) finite element methods. critical speed of the rotor wasinvestigated in the campbell diagram, which shows the relationship between natural frequency and rotational velocity of the system when the motor is not in operation. the 1d finite element analysis shows that there are two modes which are close to the design frequency of 300 hz i.e. mode 1 and 2. however the critical rotational velocity in both modes are still far above the maximum velocity design of 6,000 rpm. validation using 3d finite element analysis demonstrated that all modes werestill above the designed frequency and did not find any critical speed below 6,000 rpm. it can be concluded that the critical speed of the rotor of ipm motor is still outside the system resonance region, and canbe operated safely. (author) keywords: natural frequency, campbell diagram, interior permanent magnet motor, finite element method. yanuandri putrasari a , haznan abimanyu b , achmad praptijanto a , arifin nur a , yan irawan b , sabar pangihutan simanungkalit b ( a research centre for electrical power & mechatronics, indonesian institute of sciences, bandung, indonesia; b research center for chemistry, indonesian institute of sciences, serpong, indonesia) experimental investigation of 2 nd generation bioethanol derived from empty-fruit-bunch (efb)of oil-palmon performance and exhaust emission of si engine mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 9-16, 6 ill, 2 tab, 41 ref. the experimental investigation of2nd generation bioethanol derived from efb of oil-palm blended with gasoline for 10, 20, 25% by volume and pure gasoline were conducted on performance and exhaust emission tests of si engine. a four stroke, four cylinders, programmed fuel injection (pgmfi), 16 valves variable valve timing and electronic lift control (vtec), single overhead camshaft (sohc), and 1,497 cm3 si engine (honda/l15a) was used in this investigation. engine performance test was carried out for brake torque, power, and fuel consumption. the exhaust emission was analyzed for carbon monoxide (co) and hydrocarbon (hc). the engine was operated on speed range from 1,500 until 4,500 rev/min with 85% throttle opening position. the results showed that the highest brake torque of bioethanol blends achieved by 10% bioethanol content at 3,000 to 4,500 rpm, the brake power was greater than pure gasoline at 3,500 to 4,500 rpm for 10%bioethanol, and bioethanol-gasoline blends of 10 and 20% resulted greater bsfc than pure gasoline at low speed from 1,500 to 3,500 rpm. the trend of co and hc emissions tended to decrease when the engine speed increased. (author) keywords: bioethanol, si engine, performance, emission. rudi uswarman a , adha imam cahyadi a , oyas wahyunggoro a ( a department of electrical engineering and information technology, universitas gadjah mada, yogyakarta, indonesia) design and implementation of a magnetic levitation system controller using global sliding mode control mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 17-26, 19 ill, 0 tab, 14 ref. this paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. sliding mode control will be robusting when in sliding mode condition. however, it is not necessarily robust at attaining phase. in the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. however, the value of the parameter uncertainties needs to be limited. besides that, the common problem in sliding mode control is high chattering phenomenon. if the chattering is too large, it can make the system unstable due the limited ability of electronics component. the strategy to overcome the chattering phenomenon is needed. based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control. (author) keywords: magnetic levitation system, global sliding mode control, conventional sliding mode control, chattering. eka samsul ma’arif a,b , endra pitowarno a , rusminto tjatur w a ( a electronic engineering polytechnic institute of surabaya, indonesia; b astra manufacturing polytechnic, north jakarta, indonesia) a trajectory generation method based on edge detection for auto-sealant cartesian robot mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 27-36, 19 ill, 5 tab, 17 ref journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv this paper presents algorithm ingenerating trajectory for sealant process using captured image. cartesian robot as auto-sealant in manufacturing process has increased productivity, reduces human error and saves time. but, different sealant path in many engine models means not only different trajectory but also different program. therefore robot with detection ability to generate its own trajectory is needed. this paper describes best lighting technique in capturing image and applies edge detection in trajectory generation as the solution. the algorithm comprises image capturing, canny edge detection, integral projection in localizing outer most edge, scanning coordinates, and generating vector direction codes. the experiment results show that the best technique is diffuse lighting at 10 cd. the developed method gives connected point to point trajectory which forms sealant path with a point to next point distance is equal to 90° motor rotation. directional movement for point to point trajectory is controlled by generated codes which are ready to be sent by serial communication to robot controller as instruction for motors which actuate axes x and y directions. (author) keywords: canny edge detection, integral projection, scanning the coordinate, vector direction code. roni permana saputra a,b , tinton dwi atmaja a , budi prawara a ( a research centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia; b school of mechanical and manufacturing engineering, the university of new south wales, australia) distributed control system design for portable pc based cnc machine mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 37-44, 13 ill, 1 tab, 21 ref. the demand on automated machining has been increased and emerges improvement research to achieve many goals such as portability, low cost manufacturability, interoperability, and simplicity in machine usage. these improvements are conducted without ignoring the performance analysis and usability evaluation. this research has designed a distributed control system in purpose to control a portable cnc machine. the design consists of main processing unit, secondary processing unit, motor control, and motor driver. a preliminary simulation has been conducted for performance analysis including linear accuracy and circular accuracy. the results achieved in the simulation provide linear accuracy up to 2 μm with total cost for the whole processing unit is up to 5 million idr. (author) keywords: distributed control, portable cnc machine, linear interpolation, circular interpolation. dany perwita sari a , kang-pyo cho b ( a research center for biomaterials, indonesian institute of sciences, cibinong, indonesia; b ckp wind solutions, gimje si, south korea) cfd and wind tunnel analysis for mounted-wind turbine in a tall building for power generation mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 45-50, 5 ill, 1 tab, 13 ref. a mounted wind turbine on the top of a tall building may provide high wind power in regions of high wind speed and low turbulence. the objective of this study is to evaluate wind speed on roof top models to optimize the wind turbine performance for power generation. comparative analyses from three different roof top models were conducted. computational fluid dynamics (cfd) simulation and wind tunnel testing were performed to evaluate the performance of wind turbine. wind speed on the building model with a geometric scale of 1:150 was measured in cfd simulation then it was validated in wind tunnel test. results presented in this paper suggest that an increase of wind speed could be achieved with ¼ circular shapes around the rooftop which can provide additional wind speed of 55.24%, respectively. (author) keywords: wind speed, roof shape, cfd, wind tunnel, tall building. merry indahsari devi a , kristian ismail a , arifin nur a ( a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia) techno-economic analysis of biogas utilization as an alternative fuel mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 51-58, 2 ill, 12 tab, 16 ref. this paper will discuss the feasibility and economic analysis of biogas energy as a supply for the diesel engine generator. the techno-economic analysis was performed by using three parameters which are net present value (npv), internal rate of return (irr), and payback period (pp) as the feasibility indicators of the biogas power plant project. calculation of substitution was obtained from the comparison between data of diesel engine using diesel fuel and dual-fuel with biogas. economic calculations include the substitution percentage of diesel fuel by biogas for dual-fuel. meanwhile, the calculation of savings was based on the ratio of energy content between diesel fuel and biogas. the eventual outcome is determined using economic comparison between the use of diesel fuel and dual-fuel mode. feasibility shows that the pilot plant of 1 to 6 kwh using diesel fuel and dual-fuel are not feasible while techno-economic parameter analysis shows that npv<0, irr<marr, while pp is undefined. the biogas power plant project is feasible in some conditions such as there is no labor cost, and 5 and 6 kwh will be feasible under the assumption that expenses for machine maintenance is eliminated. however, even when applying both conditions where biogas is feasible, diesel fuel is still not. (author) keywords: techno-economic, feasibility, biogas, diesel fuel, dualfuel. rizqon fajar a , hari setiapraja a ( a center for thermodynamic, motor and propulsion the agency for assessment and application of technology (btmp-bppt), serpong, indonesia) the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation mechatronics, electrical power, and vehicular technology, july 2014, vol. 5, no. 1, p. 59-66, 10 ill, 4 tab, 11 ref. experimental research has been conducted to investigate the effects of blend of hydrogenated and unhydrogenated jatropha biodiesel with diesel fuel in volume ratio of 30:70 (b30) on combustion characteristics (bsfc, thermal efficiency and smoke emission) of single cylinder diesel engine. in this experiment, engine speed was kept constant at 1,500, 2,500, and 3,500 rpm with maximum engine load at bmep 5 bar and injection timings were varied. experimental result showed that at engine speed 1,500 rpm, bsfc of b30 hydrogenated and unhydrogenated jatropha biodiesel were higher than it of diesel fuel at all injection timings (10 to 18°btdc). at the same condition, partial hydrogenated jatropha biodiesel showed higher bsfc than unhydrogenated jatropha biodiesel. however, the difference in bsfc became smaller for all fuels at engine speed 2,500 rpm and 3,500 rpm at all injection timing. jatropha biodiesel with and without partial hydrogenation tend to have higher thermal efficiency compared with diesel fuel at all engine speed and injection timing. the best injection timings to operate b30 jatropha biodiesel with and without hydrogenation were 14, 18 and 24°btdc at engine speed 1,500, 2,500, and 3,500 rpm respectively. this conclusion was deduced based on the minimum value of bsfc and the maximum value of thermal efficiency. smoke emissions for all fuels were in the same level for all conditions. (author) keywords: jatropha, hydrogenation, bsfc, thermal efficiency, smoke emission mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 05, issue 2, december 2014 aim and scope mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal providing authoritative source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev journal vision is to become international platform with high scientific contribution for global community. mev journal mission is presenting important results of work, in the form of research, development, application, or design. editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi) komp lipi jl sangkuriang, bld 20, 2 nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h1034, hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia za@dynamic.pauir.itb.ac.id prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, bld 20, 2 nd fl, bandung 40135, ndonesia budi.prawara@lipi.go.id mailto:patko@uni-obuda.hu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 05, issue 2, december 2014 imprint journal of mechatronics, electrical power, and vehicular technology (mev) is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). mev journal is managed to be issued twice in every volume. issn print edition: 2087-3379 issn electronics edition: 2088-6985 electronic edition is available at: www.mevjournal.com accreditation accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 mev has been certified as a national scientific journal by indonesian institute of sciences (lipi) on 24 april 2012. valid until: 24 april 2015 indexing & abstracting indexed in ebscohost, index copernicus, directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), indonesian publication index (ipi), crossref, mendeley, citeulike, cite factor, academic journal database, and researchbib. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2 nd floor bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 managing editors aam muharam, m.t. electrical engineering aam.muharam@lipi.go.id dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com layout editors arief a firdaus, s.i.kom. communication science rif212@yahoo.com bambang wahono, m.eng. mechanical engineering bambangwahono80@yahoo.co.id midriem mirdanies, m.t. computer engineering midr001@lipi.go.id secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com vita susanti, s.kom. computer science vitasusanti@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com section editors amin, m.t. electrical engineering amin_hwi@yahoo.co.id arini wresta, m.eng. chemical engineering awresta@gmail.com dian andriani, m.eng. bioenergy engineering dea1401@yahoo.com ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com hendri m saputra, m.t. robotics and mechatronics hendri_maja@yahoo.co.id naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com rakhmad i pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id graphic designer m redho kurnia, s.sn. graphic design muha058@lipi.go.id http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 © 2014 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 05, issue 2, december 2014 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has been indexed by google scholar, ebscohost, index copernicus, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib and cite factor. in addition, it has been granted digital object identifier with the doi prefix 10.14203. in near future we are planning to be indexed by scopus. this issue publishes nine papers with the total number of paper pages of 72 pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. five topics are related to mechatronics, one topic to electrical power and three topics to vehicular technology. the authors came from usa, vietnam, pakistan, jordan, philippines and indonesia. the policy up to this current issue is that both authors and readers are not charged at all. on the other hand, the editorial board is planning to improve the quality by registering the journal to other international academic citation index. moreover, the editorial board is also considering to gradually increase the number of papers and journal’s pages. all of this plan will give consequence on financial burden. therefore, from the next issue, financial policy will probably change based on that condition. we wish to offer our thanks to all the editorial members and indonesian institute of sciences (lipi) for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology bandung, december 2014 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 05, issue 2, december 2014 list of contents proportional derivative active force control for “x” configuration quadcopter ni’am tamami, endra pitowarno, i gede puja astawa 67-74 design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle aditya sukma nugraha, bagus budiwantoro, estiko rijanto 75-82 evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system sunarto kaleg, aam muharam, muhammad redho kurnia, abdul hapid 83-90 learning efficiency of consciousness system for robot using artificial neural network osama shoubaky, tala m. sharari 91-98 adhesion detection analysis by modeling rail wheel set dynamics under the assumption of constant creep coefficient zulfiqar ali soomro 99-106 design and development of rc railed robot for coffee nursery logistics marivic g. dizon, carlo t. sevillano, mark anthony t. cabaluna 107-114 comparison of unmodulated current control characteristics of permanent magnet synchronous motor anwar muqorobin, pudji irasari, taufik 115-122 braking system modeling and brake temperature response to repeated cycle zaini dalimus 123-128 an experiment of ocular artifacts elimination from eeg signals using ica and pca methods arjon turnip, iwan r. setiawan, edy junaidi, le hoa nguyen 129-138 further articles can be found at www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 05, issue 2, december 2014 abstracts sheet e-issn: 2088-6985 date of issues: 24 december 2014 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. ni’am tamami, endra pitowarno, i gede puja astawa (electronics engineering polytechnic institute of surabaya, surabaya, indonesia) proportional derivative active force control for “x” configuration quadcopter mechatronics, electrical power, and vehicular technology, december 2014, vol. 5, no. 2, p. 67-74, 10 ill, 2 tab, 16 ref. this paper presents a stabilization control method for “x” configuration quadcopter using pdafc (proportional derivative active force control). pd is used to stabilize quadcopter, whereas afc is used to reject disturbance uncertainty (e.g. wind) by estimating disturbance torque value of quadcopter. simulation result shows that pdafc is better than pd and afc can minimize disturbance uncertainly effect. the sensitivity toward disturbance uncertainly can be set from sensitivity constant to get best performance of disturbance rejection. constant disturbance simulation result shows that the best sensitivity constant ( ) is 0.15, the quadcopter maximum error is 0.125 radian and can stable in 5 seconds. fluctuated disturbance simulation result shows that pdafc with 0.18 sensitivity constant gives lowest rms error value, there are 0.074 radian for sine disturbance, 0.055 radian for sawtooth disturbance, and 0.092 radian for square pulse disturbance. (author) keywords: “x” configuration quadcopter, pd, afc. aditya sukma nugraha a , bagus budiwantoro b , estiko rijanto a ( a research center for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia; b faculty of mechanical and aerospace engineering, institut teknologi bandung, indonesia) design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle mechatronics, electrical power, and vehicular technology, december 2014, vol. 5, no. 2, p. 75-82, 12 ill, 4 tab, 21 ref. this paper presents a design of vibration absorber using spring and rubber for 5.56 mm caliber rifle armored vehicle. such a rifle is used in a remote-controlled weapon system (rcws) or a turret where it is fixed using a two degree of freedom pan-tilt mechanism. a half car lumped mass dynamic model of armored vehicles was derived. numerical simulation was conducted using fourth order runge kutta method. various types of vibration absorbers using spring and rubber with different configurations are installed in the elevation element. vibration effects on horizontal direction, vertical direction and angular deviation of the elevation element was investigated. three modes of fire were applied i.e. single fire, semiautomatic fire and automatic fire. from simulation results, it was concluded that the parallel configuration of damping rubber type 3, which has stiffness of 980,356.04 (n/m 2 ) and damping coefficient of 107.37 (n.s/m), and carbon steel spring whose stiffness coefficient is 5.547 x 106 (n/m 2 ) provides the best vibration absorption. (author) keywords: vibration absorber, spring, rubber, armored vehicle, rifle. sunarto kaleg, aam muharam, muhammad redho kurnia, abdul hapid (research center for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia) evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system mechatronics, electrical power, and vehicular technology, december 2014, vol. 5, no. 2, p. 83-90, 13 ill, 0 tab, 15 ref. the main target of a steering system isthat the driver can change vehicle trajectory in accordance with the desired direction. power steering has become a standard feature in automobile. it provides assisting power when the driver turns the steering wheel. the wellknownpower steering types include; hydraulic power steering (hps), electro hydraulic power steering (ehps), and electric power steering (eps). ehps or eps uses an electronic control unit (ecu), which is specific for each vehicle. the ecu should be able to regulate power of electric motor to provide corresponding assisting power for the steering wheel. therefore, ecu requires input signals, one of which is vehicle wheel angle that can be indicated from the vehicle steering wheel angle. incremental type of rotary encoder (re) is used in steering angle sensor on a minibus. re specification used was 60 pulses per rotation and the minibus steering transmission specification is 3.5 round of right wheel off angle to the left wheel off angle. so we get the re angular resolution of 6º per pulse and 105 number of pulses to half of the steering transmission ratio. repeatability then tested against a steering angle counter module. testing is donewith a test cycle consisting 3 repetitions: condition center of the steering wheel, the steering wheel is turned to full right, then to the full left, then back to the right up to the steering wheel center. the results obtained was 2 pulses deviation, or equivalent to 12º of steering angle. (author) keywords: vehicle steering system, rotary encoder, incremental, steering wheel angle, repeatability. osama shoubaky a , tala m. sharari b ( a computer and intelligent systemscenter, jordan; b institute of engineering &technology, department of electrical engineering, control laboratory and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv automation, jordan) learning efficiency of consciousness system for robot using artificial neural network mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 91-98, 9 ill, 4 tab, 18 ref. this paper presents learning efficiency of a consciousness system for robot using artificial neural network. the proposed conscious system consists of reason system, feeling system and association system. the three systems are modeled using module of nerves for advanced dynamics (modnad). artificial neural network of the type of supervised learning with the back propagation is used to train the modnad. the reason system imitates behaviour and represents self-condition and other-condition. the feeling system represents sensation and emotion. the association system represents behaviour of self and determines whether self is comfortable or not. a robot is asked to perform cognition and tasks using the consciousness system. learning converges to about 0.01 within about 900 orders for imitation, pain, solitude and the association modules. it converges to about 0.01 within about 400 orders for the comfort and discomfort modules. it can be concluded that learning in the modnad completed after a relatively small number of times because the learning efficiency of the modnad artificial neural network is good. the results also show that each modnad has a function to imitate and cognize emotion. the consciousness system presented in this paper may be considered as a fundamental step for developing a robot having consciousness and feelings similar to humans. (author) keywords: consciousness, robot, artificial neural network. zulfiqar ali soomro (directorate of post-graduate studies, mehran university of engg &tech jamshoro (sindh), pakistan) adhesion detection analysis by modeling rail wheel set dynamics under the assumption of constant creep coefficient mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 99-106, 5 ill, 0 tab, 21 ref. adhesion level controlplays significant role in order to keep smooth running of a train. to design a proper adhesion controller, adhesion dynamics needs to be analyzed. in this paper adhesion is analyzed by modeling rail wheel set dynamics under the assumption of constant creep coefficient. equations of creepage and creep forces were derived in longitudinal, lateral and angular directions. numerical simulation was conducted under assumption of constant creep coefficient. the creep coefficient was obtained by applying coulomb’s law of friction. from the simulation results it can be concluded that adhesion level for suitable dynamic model determination depends on assumption of creep analysis to avoid slip or derailment of rail wheelset. (author) keywords: adhesion, rail wheel set, creep coefficient, longitudinal, lateral. marivic g. dizon, carlo t. sevillano, mark anthony t. cabaluna (cavite state university, indang, cavite, philippines) design and development of rc railed robot for coffee nursery logistics mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 107-114, 10 ill, 5 tab, 12 ref. the remote controlled (rc) railed robot was designed and developed to transfer polybags from manual operation to an automated logistic system. gizduino microcontroller was used to read and interpret commands sent and received by the transceivers to the robot and a remote to command instructions to the robot. the project was tested and evaluated at the coffee nursery of cavite state university by determining the speed of the robot, the effectiveness of the remote control and the accuracy of the robot to lift a pallet and place it into an empty space. results showed that the robot was able to receive and interpret commands provided by the remote control as well as perform the tasks successfully. the most significant recommendation was to use a counterweight at the rear side of the robot to avoid unnecessary derailments of the robot if lifting the heavier or greater number of pallets are desired. (author) keywords: remote control, coffee nursery, gizduino microcontroller, automated logistic system. anwar muqorobin a , pudji irasari a , taufik b ( a research centre for electrical power and mechatronics, indonesian institute of sciences, bandung; b electric power institute, california polytechnic state university, san luis obispo, united states of america) comparison of unmodulated current control characteristics of permanent magnet synchronous motor mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 107-114, 13 ill, 5 tab, 29 ref. this paper discusses comparison of unmodulated current controls in pmsm, more specifically, on-off, sliding mode, predictive and hybrid controls. the purpose of this study is to select the most appropriate control technique to be adopted. the comparison method is preceded by modeling the motor and entering the values of the motor parameters. pi control is used for speed control and zero d-axis current is employed. furthermore, performing simulation for each type of the selected current controls and analyzing their responses in terms of dq and abc currents, q-axis current response with step reference, as well as thd. simulation results show that the on-off control gives the best overall performance based on its abc-axis current ripple and thd at large load torque. the hybrid control shows the best response occurring only at the fastest transient time of q-axis current but its response exhibits bad qualities compared with other controls. the predictive control yields the best responses offering the smallest d-axis ripple current and thd at small load torque condition. the sliding mode control, however, does not exhibit any prominent performance compared to the others. results presented in this paper further indicate that for the pmsm used in the simulation the most appropriate control is the predictive control. (author) keywords: unmodulated current controls, on-off control, sliding mode control, predictive control, hybrid control. zaini dalimus ( a electrical engineering department, andalas university, indonesia) braking system modeling and brake temperature response to repeated cycle mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 123-128, 12 ill, 2 tab, 9 ref. braking safety is crucial while driving the passenger or commercial vehicles. large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. if the braking system fails to work, road accident could happen and may result in death. this research aims to model braking system together with vehicle in matlab/simulink software and measure actual brake temperature. first, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. next, arduino based prototype brake temperature monitoring was developed and tested on the road. from the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle. (author) keywords: raking, kinetic energy, brake characteristic, arduino. arjon turnip a , iwan r. setiawan a , edy junaidi b , le hoa nguyen c ( a technical implementation unit for instrumentation development, indonesian institute of sciences, bandung, indonesia; b department of physics, indonesian university of education, bandung, indonesia; c dept. of electrical engineering, the university of danang, vietnam) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 v an experiment of ocular artifacts elimination from eeg signals using ica and pca methods mechatronics, electrical power, and vehicular technology, december 2014, vol. 4, no. 2, p. 129-138, 9 ill, 3 tab, 25 ref. in the modern world of automation, biological signals, especially electroencephalogram (eeg) is gaining wide attention as a source of biometric information. eye-blinks and movement of the eyeballs produce electrical signals (contaminate the eeg signals) that are collectively known as ocular artifacts. these noise signals are required to be separated from the eeg signals to obtain the accurate results. this paper reports an experiment of ocular artifacts elimination from eeg signal using blind source separation algorithm based on independent component analysis and principal component analysis. eeg signals are recorded on three conditions, which are normal conditions, closed eyes, and blinked eyes. after processing, the dominant frequency of eeg signals in the range of 12-14 hz either on normal, closed, and blinked eyes conditions is obtained. (author) keywords: eeg, eog, ica, pca, artifacts elimination. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vi this page is left blank kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 41-50, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.41-50 desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine roni permana saputra1, anwar muqorrobin1, arif santoso1, teguh pudji purwanto2 1pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia. permana.saputra@yahoo.co.id 2jurusan teknik mesin dan industri – universitas gadjah mada jl. grafika no. 2, yogyakarta 55281, indonesia teguhpp@yahoo.com diterima: 13 april 2011; direvisi: 25 april 2011; disetujui: 2 mei 2011; terbit online: 7 juli 2011. abstrak makalah ini membahas tentang desain sistem kendali router berbasis computer numerical control (cnc) menggunakan personal computer (pc), untuk diimplementasikan di flame cutting machine (fcm). nc-code yang diinputkan ke komputer diterjemahkan menjadi sinyal perintah yang dikirimkan pc ke microcontroller untuk mengendalikan gerakkan end effector mesin pada sumbu x dan sumbu y secara simultan berdasarkan hasil perhitungan interpolasi linier dan interpolasi sirkular pada pc. sistem kendali ini diimplementasikan pada fcm dengan menghubungkan output kendali dari microcontroller dengan driver aktuator fcm berupa motor dc. hasil yang diperoleh berupa suatu prototipe sistem kendali router cnc untuk diimplementasikan di fcm dan mampu melakukan interpolasi linier dan interpolasi sirkular. kata kunci: kontrol cnc, cnc based pc, routercnc. abstract this paper focuses on design of router control systems based on computer numerical control (cnc) using personal computer (pc) implemented in flame cutting machine (fcm). nc-code entered into the computer translated to be a command signal sent by the pc to a microcontroller to control the end effector’s movement along the x and y axis simultaneously based on linear and circular interpolations calculation on the pc. this control system is implemented on fcm by connecting the output control of the microcontroller with the driver actuator of the fcm in the form of a dc motor. the obtained result is in the form of a cnc router control system prototype to be implemented in the fcm which is capable to perform linear interpolation and circular interpolation. keywords: cnc control, cnc based pc, router cnc. i. pendahuluan aplikasi teknologi computer numerical control (cnc) dewasa ini telah berkembang luasuntuk mesin-mesin perkakas di industri manufaktur yang membutuhkan keunggulan dalam hal fleksibilitas, akurasi, dan kemampuan pengulangan dibandingkan mesin konvensional [1]. mesin ini harus mampu mengulang gerakanidentik dengan jumlah banyak dengan ketelitian tinggi. mesin cnc bekerja berdasarkan nc-codeyang diinputkan oleh operator pada perangkat kendalinya [2]. jika suatu program telah dibuat untuk membuat suatu produk, maka operator hanya tinggal mengulangi proses running dari program itu sebanyak produk yang ingin dihasilkan. salah satu jenis mesin yang mengunakan teknologi cnc ialah mesin pemotong plat dengan berbagai macam model alat irisnya, diantaranya flame cutting machine produk ltech peacemaker yang terdapat dilaboratorium cnc teknik mesin ugm [3]. mesin ini memiliki kemampuan memotong platdengan kontur sesuai dengan program cnc yang diinputkan. mesin ini mengalami kerusakan pada sistem pengontrol cnc, sehingga tidak dapat lagi dioperasikan. salah satu kendala yang ada adalah sulit dan mahalnya suku cadang mesin. sementara itu, saat ini sudah banyak dikembangkan penelitian mengenai pengendalian mesin cnc berbasis pc. hal ini banyak dilakukan untuk menghasilkan mesin cnc yang lebih murah, serta dengan suku cadang yang mudah didapat [4] [5]. untuk itu, pada penelitian ini dilakukan desain sistem kendali router berbasis cnc menggunakan pc dengan tetap mempertahankan metode pengendalian mesin dengan nc-code untuk dapat diimplementasikan di flame cutting http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine (roni permana saputra, anwar m., arif s., teguh p.p.) jmev 02 (2011) 41-50 42 machine. adapun tujuan dari penulisan makalah ini adalah untuk melaporkan unjuk kerja dari hasil desain sistem kendali diatas dengan melakukan eksperimen di laboratorium ii. teori pada perancangan ini, mesin yang dikendalikan berupa mesin cnc flame cutting machine dengan geometri kartesian yang memiliki gerakan end effector mesin dalam dua arah yang independen, yaitu arah x, dan arah y. untuk mengatur gerakan kedua aktuator secara simultan dilakukan dengan interpolasi linear untuk membentuk garis lurus, dan interpolasi sirkular untuk membentuk busur lingkaran a. interpolasi linear untuk menghasilkan garis lurus, digunakan pendekatan dengan runtutan gerakan-gerakan pendek yang terkoordinasi oleh sistem pengendali. metode runtutan gerakan-gerakan ini dinamakan quasi continuous movement [6]. untuk menggerakkan end effektor membentuk garis lurus dari titik (x1,y1) ke titik (x2,y2), end effektor digerakkan nx step dalam arah sumbu x dan ny step dalam arah sumbu y [6]. untuk nilai gradien positif, apabila koordinat posisi end effector saat ini berada diatas kurva, maka step gerakan berikutnya adalah ke kanan, dan apabila kooordinat posisi alat potong saat ini berada di bawah kurva, maka step gerakan motor berikutnya adalah ke atas. untuk gradien garis negatif, gerakan end effector ke arah sebaliknya. metode yang dijelaskan pada bagian ini disebut dengan metode direct function estimation method (metode dfe) [7]. b. interpolasi sirkular interpolasi sirkular digunakan untuk membentuk busur lingkaran. proses pembuatan busur lingkaran ditunjukkan pada gambar 1. busur lingkaran dapat dinyatakan dengan menentukan titik awal (x1,y1), titik akhir (x2,y2), arah putar dan posisi relatif pusat lingkaran terhadap titik awal (i,j). maka busur lingkaran yang dimaksud ditunjukkan pada gambar 1a [6]. nilai a merupakan posisi sudut titik awal (x1,y1) terhadap titik pusat busur lingkaran. nilai b merupakan posisi sudut titik akhir (x2,y2) terhadap titik pusat busur lingkaran. nilai θ merupakan posisi sudut titik-titik sepanjang busur (xn,yn) terhadap titik pusat busur. busur lingkaran pada gambar 1 didekati dengan poligon bersegi banyak seperti pada gambar 1b [6]. pada gambar 1b diperlihatkan bahwa untuk mendapatkan busur lingkaran yang mulus dapat dilakukan dengan membuat segmen garis sekecil mungkin sedemikian rupa sehingga nilai t yang diperoleh berupa toleransi. untuk membuat segmen garis poligon dari busur lingkaran dilakukan dengan membagi busur lingkaran dengan sudut θ menjadi juring-juring dengan sudut g. maka akan dihasilkan segmensegmen garis dimana segmen garis ke-n memiliki koordinat titik awal (xn-1, yn-1) dan koordinat titik akhir (xn,yn). setelah diperoleh titik awal dan titik akhir segmen garis poligon tersebut, kemudian dilakukan interpolasi linier [6]. c. pengendalian mesin menggunakan nccode mesin cnc bekerja untuk memotong benda kerja dengan lintasan pemotongan sesuai dengan kode-kode numerical control yang telah diberikan yang dikenal dengan nc-code. nc-code yang digunakan pada perancangan sistem kendali pada penelitian ini ditunjukkan pada tabel 1 [6]. iii. pelaksanaan penelitian penelitian ini terdiri dari tahap perancangan sistem pengendali router cnc yang terdiri dari perangkat keras dan perangkat lunak, pengujian linieritas, pengujian repeatabilitas, pengujian interpolasi linear, dan pengujian interpolasi sirkular. diagram blok dari sistem kendali yang dibuat, ditunjukkan pada gambar 2. (a) (b) gambar 1. proses pembuatan busur lingkaran(a) parameter-parameter pada busur lingkaran, (b) poligon pendekatan busur lingkaran. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 41-50, 2011 p-issn 2087-3379 43 tabel 1. daftar nc-code. kode eksekusi yang dilakukan g00 interpolasi linear tanpa pemotongan g01 interpolasi linear dengan pemotongan dengan dimensi normal g02 interpolasi sirkular cw dengan pemotongan dengan dimensi normal g03 interpolasi sirkular ccw dengan pemotongan dengan dimensi normal g04 waktu penundaan dengan lamanya waktu ditentukan dengan nilai f g10 interpolasi linear dengan pemotongan dengan dimensi panjang (10x) g11 interpolasi linear dengan pemotongan dengan dimensi pendek g20 interpolasi sirkular cw dengan pemotongan dengan dimensi panjang(10x) g21 interpolasi sirkular cw dengan pemotongan dengan dimensi pendek g30 interpolasi sirkular ccw dengan pemotongan dengan dimensi panjang (10x) g31 interpolasi sirkular ccw dengan pemotongan dengan dimensi pendek g90 pemrograman dimensi absolut g91 pemrograman dimensi inkrimental m00 program berhenti sampai ditekan kembali tombol jalankan. m30 akhir dari program gambar 2. diagram blok rancangan sistem pengendali router cnc. a. perancangan perangkat keras perangkat keras sistem pengendali router cnc ini berupa pc dan rangkaian elektronika yang terintegrasi untuk melakukan pengendalian aktuator. aktuator yang dikendalikan berupa dua motor dc yang masing-masing menggerakkan sumbu x dan sumbu y. rangkaian elektronika pada sistem ini berupa rangkaian sistem microcontroller untuk komunikasi dengan pc sebagai pengendali, rangkaian penggerak motor dc, dan rotary encoder untuk feed back posisi. gambar 3 menunjukkan skema keseluruhan rangkaian elektronika sistem pengendali router cnc. microcontroller menerima data posisi dari pc. kemudian microcontroller mengaktifkan aktuator agar end effector bergerak ke posisi yang diperintahkan. sinyal feed back dari rotary gambar 3. skema rangkaian elektronik pengendali router cnc. desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine (roni permana saputra, anwar m., arif s., teguh p.p.) jmev 02 (2011) 41-50 44 gambar 4. algoritma perangkat lunak kendalidi microcontroller. encoder diterima oleh microcontroller untuk memastikan end effector telah bergerak ke posisi yang tepat. perangkat lunak di komputer berfungsi untuk menerjemahkan nc-code yang diinputkan dengan proses interpolasi linier atau interpolasi sirkular berdasarkan input program nc-code dan sebagai antar muka antara operator dengan mesin. pada gambar 5, ditunjukkan algoritma proses interpolasi linier dan interpolasi sirkular pada komputer. untuk interpolasi linier (gambar 5a), input yang dibutuhkan nilai koordinat tujuan (x2,y2). sedangkan nilai koodinat awal (x1,y1) sudah tersimpan di memori. dari input tersebut kemudian dihitung nilai gradien (m) [7]. kemudian dari gradien tersebut bisa dihitung nilai fungsi etimasi dari titik sesaat end effector [7]. dari perhitungan fungsi estimasi dan nilai dari δx, ditentukan pergerakan end effector kekiri, kanan, atas, atau bawah yang selanjutnya sinyal kendali tersebut dikirimkan pc ke microcontroller. untuk interpolasi sirkular (gambar 5b), input yang dibutuhkan koordinat tujuan (x2,y2), arah busur, dan posisi titik pusat (i,j). dari nilai input (a) (b) gambar 5. diagram alir perangkat lunak kendali di pc(a) diagram alir interpolasi linier (b) diagram alir interpolasi sirkular. mulai baca data sinyal kendali dari pc aktifkan aktuator (motor x dan motor y) baca feedback posisi dari rotary encoder posisi ok? matikan aktuator (motor x dan motor y) selesai ya tidak mulai baca input data (x,y) hitung gradien (m) x & y ≠ 0 ? gradien > 0 ? δx > 0 ? δx > 0 ? x > 0 => geser kanan x < 0 => geser kiri y < 0 geser atas y < 0 geser bawah estimasi > 0 => geser kanan estimasi < 0 => geser atas selesai estimasi > 0 => geser bawah estimasi < 0 => geser kiri estimasi > 0 => geser bawah estimasi < 0 => geser kanan estimasi > 0 => geser kiri estimasi < 0 => geser atas ya tidak ya tidak ya tidak ya tidak mulai baca input data (x, y, i, j) selesai hitung nilai r hitung nilai α hitung nilai γ hitung nilai β hitung nilai θ = α−β hitung jumlah segmen poligon n = θ/γ hitung koordinat segmen (xn,yn) interpolasi linier (xn,yn) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 41-50, 2011 p-issn 2087-3379 45 tersebut dihitung nilai jari jari r [6]. selanjutnya dihitung nilai α dan β [6]. nilai θ merupakan selisih dari α dan β seperti pada gambar 4. selanjutnya untuk membagi busur menjadi poligon, nilai γ dihitung sebagai sudut pembagi [6]. setelah didapat poligon segi-n, dihitung nilai koordinat tiap-tiap ruas garis poligon tersebut (xn,yn) [6]. setelah didapat koordinat masingmasing ruas garis poligon tersebut, tinggal dilakukan interpolasi linier sesuai diagram alir pada gambar 5a. selain sebagai kendali utama, pc juga digunakan sebagai sarana perantara antara operator dengan sistem pengendali, dimana operator akan menginputkan program nc-code untuk menggerakkan mesin ke pc. maka dibuat tampilan user interface di pc. tampilan user interface dirancang sedemikian hingga dapat menampilkan layar yang memuat nc-code yang diimputkan, hasil kompile, dan gambar simulasi pergerakan mesin dari program yang diinputkan. selain layar tersebut, user interface juga dirancang agar panel kendali yang terdapat didalamnya mudah untuk mengoperasikan mesin. b. pengujian linieritas pengujian linieritas dilakukan dengan menginputkan program gerakan lurus sepanjang 50 mm sampai dengan 200 mm secara bertahap pada sistem kendali untuk gerakkan arah sumbu x dan sumbu y. gambar 6 menunjukkan proses pengujian gerakan end effector mesin. setelah mesin dijalankan, end effector mesin yang telah dipasangi spidol dan diletakkan white board di bawahnya seperti terlihat pada gambar 6 gambar 6. pengujian gerakan end effector mesin. akan melakukan gerakkan sesuai progam yang diinputkan. selanjutnya pergerakan end effector mesin yang tergambar di whiteboard diukur panjang gerakkan aktual yang terbentuk berdasarkan gambar tersebut, kemudian dihitung koefisien regresi linier dari nilai-nilai terukur tersebut. c. pengujian repeatabilitas pengujian repeatabilitas dilakukan dengan menginputkan program gerakan lurus sepanjang 100 mm berulang-ulang sebanyak seratus kali. selanjutnya pergerakan end effector mesin yang tergambar di white board diukur panjang gerakkan aktualnya, kemudian dihitung simpangan standar deviasi dari nilai terukur tersebut. d. pengujian interpolasi linier pengujian kemampuan interpolasi linear dilakukan dengan menginputkan program nccode untuk membentuk suatu pola yang terdiri dari garis-garis lurus. kemudian, nc-code ang telah diinputkan tersebut disimulasikan dan dieksekusi untuk kemudian diamati hasilnya. e. pengujian interpolasi sirkular pengujian kemampuan interpolasi sirkular dilakukan dengan menginputkan program nccode untuk membentuk suatu pola yang terdiri dari busur-busur lingkaran.kemudian, nc-code yang telah diinputkan tersebut disimulasikan dan dieksekusi untukkemudian diamati hasilnya. iv. hasil dan pembahasan dari penelitian ini, dihasilkan sistem pengendali router berbasis cnc untuk diimplementasikan di flame cutting machine. pada gambar 7 ditunjukkan tampilan user interface sistem kendali di pc. tampilan layar utama sistem kendali (gambar 7a) terdiri dari layar input yang berfungsi untuk memasukan input program nc-code yang akan disimulasikan ataupun dieksekusi, dan layar output berfungsi untuk menampilkan baris program yang sedang dieksekusi. jika program nc-code yang telah diinputkan disimulasikan, maka akan muncul tampilan layar simulasi (gambar 7b) yang menunjukkan simulasi gerakan end effector mesin sesuai dengan nccode yang diinputkan. fungsi dari tombol-tombol yang terdapat pada tampilan utama sistem kendali ditunjukkan pada tabel 2. selanjutnya, hasil pengujian linearitas positioning end effector mesin ditunjukkan pada tabel 3 dan gambar 8. desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine (roni permana saputra, anwar m., arif s., teguh p.p.) jmev 02 (2011) 41-50 46 (a) (b) gambar 7. tampilan user interface sistem kendali di pc (a) tampilan layar utama, (b) tampilan layar simulasi. tabel 2. fungsi tombol-tombol pada tampilan utama sistem kendali. tombol fungsi tombol fungsi kelompok tombol ini berfungsi untuk proses input data program nc-code ke dalam pc. tombol simulasi berfungsi untuk melakukan simulasi program nc-code yang diinputkan. kelompok tombol ini berfungsi untuk proses pengecekan program nc-code dari kemungkinan error. kelompok tombol ini berfungsi untuk melakukan eksekusi, pause, dan menghentikan eksekusi program nc-code yang diinputkan. option button ini berfungsi untuk memilih metode pemrograman yang digunakan antara sistem inkrimental dan sistem absolut. kelompok tombol ini berfungsi untuk menggerakkan end effector secara manual (tanpa nc-code)ke empat arah yaitu arah x+, x-, y+, dan y-. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 41-50, 2011 p-issn 2087-3379 47 tabel 3. data hasil pengujian linearitas. sumbu x positif (mm) sumbu x negatif (mm) sumbu y positif (mm) sumbu y negatif (mm) setting nilai terukur setting nilai terukur setting nilai terukur setting nilai terukur 50 52,63 50 52 50 51,5 50 52 75 77,12 75 76 75 77 75 77 100 102 100 101 100 101 100 103 125 128 125 126 125 126 125 127 150 155 150 150 150 150 150 151 175 178 175 175 175 175 175 177 200 202 200 201 200 201 200 202 (a) (b) (c) (d) gambar 8. grafik hasil pengujian linearity (a) pengujian sumbu x positif, (b) pengujian sumbu x negatif, (c) pengujian sumbu y positif, (d) pengujan sumbu y negatif. hasil perhitungan regresi linier menunjukkan bahwa untuk gerakan end effector pada arah sumbu x positif (gambar 8a), sumbu x negatif (gambar 8b), sumbu y positif (gambar 8c), dan sumbu y negatif (gambar 8d) dikatakan linier dengan koefisien regresi linier r = 0,999. untuk kondisi ideal, persamaan regresi linier untuk masing-masing arah gerakan ialah y = x, atau dengan kata lain gerakan aktual yang dilakukan end effector mesin harus sama dengan nilai yang diinputkan ke program. dari grafik menunjukkan koefisien x pada masing-masing persamaan sudah mendekati 1. nilai ini menunjukkan perbandingan antara nilai setting, sudah sama dengan nilai aktualnya. namun pada masingmasing persamaan terlihat adanya nilai konstanta sebesar 2,308 untuk sumbu x positif, 1,928 untuk sumbu x negatif, 2,089 untuk sumbu y positif, dan 2.357 untuk sumbu y negatif. nilai ini menunjukkan adanya rata-rata pergeseran dari nilai setting pada masing-masing sumbu sebesar 2 mm. hal ini dikarenakan oleh error sistemik dari pembacaan rotary encoder sebagai feed back posisi oleh microcontroller. untuk memperbaiki akurasi gerakan end effector, nilai ini bisa dimasukkan sebagai nilai koreksi. untuk hasil pengujian positioning repeatability pada end effector mesin ditunjukkan pada gambar 9. y = 1.004x + 2.308 r² = 0.999 0 50 100 150 200 250 0 100 200 n ila i a kt ua l ( m m ) nilai setting (mm) sumbu x positif y = 0.991x + 1.928 r² = 0.999 0 50 100 150 200 250 0 100 200 n ila i a kt ua l ( m m ) nilai setting (mm) sumbu x negatif y = 0.990x + 2.089 r² = 0.999 0 50 100 150 200 250 0 100 200 n ila i a kt ua l ( m m ) nilai setting (mm) sumbu y positif y = 0.997x + 2.357 r² = 0.999 0 50 100 150 200 250 0 100 200 n ila i a kt ua l ( m m ) nilai setting (mm) sumbu y negatif desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine (roni permana saputra, anwar m., arif s., teguh p.p.) jmev 02 (2011) 41-50 48 (a) (b) (c) (d) gambar 9. grafik hasil pengujian repeatability (a) pengujian sumbu x positif, (b) pengujian sumbu x negatif, (c) pengujian sumbu y positif, (d) pengujan sumbu y negatif. dari gambar 9, bisa dilihat hasil pengukuran aktual pergerakan end effector mesin pada pengujian repeatabilitas. nilai yang diinputkan pada pengujian ini adalah 100 mm untuk masingmasing arah sumbu. nilai pergerakkan aktual diukur dan dirata-ratakan dari semua pengulangan. dari hasil perhitungan nilai ratarata tersebut didapat pergeseran nilai rata-rata terhadap nilai setting sebesar 2,31 mm pada sumbu x positif (gambar 9a), 2,63 mm pada sumbu x negatif (gambar 9b), 2,59 mm pada sumbu y positif (gambar 9c), dan 2,27 mm pada sumbu y negatif (gambar 9d). seperti pada pengujian linieritas, pergeseran nilai rata-rata ini menunjukkan adanya error sistemik. semua nilai pengukuran berada di atas nilai setting menunjukkan kemungkinan error sistemik diakibatkan belum adanya kontrol pengereman yang baik dari kontrol motor, sehingga ketika kontrol memerintahkan untuk berhenti aktuator tidak dapat langsung berhenti seketika sehingga menimbulkan kelebihan pergerakan dari yang diinputkan. dari hasil perhitungan statistik didapat nilai standar deviasi 1,82 mm pada sumbu xpositif, 1,84 mm pada sumbu x negatif, 1,66 mm pada sumbu y positif, dan 1,42 mm pada sumbu y negatif. nilai ini menunjukkan ketelitian positioning end effector mesin dengan menggunakan sistem kendali ini rata-rata sebesar ± 1,82 mm. selanjutnya, pada gambar 10 ditunjukkan hasil dari pengujian kemampuan interpolasi linier dengan menguji kemampuan sistem untuk membentuk pola linier berbentuk bintang segi delapan. pola linier (gambar 10a) diujikan dengan menginputkan nc-code untuk pergerakan linier dan koordinatnya ke sistem kendali (gambar 10b). setelah program di-running, bentuk yang diujikan dapat disimulasikan dan dieksekusi dengan baik. hasil simulasi pada layar simulasi (gambar 10c) dan hasil gambar pergerakan aktual end effector mesin (gambar 10d) menunjukkan bentuk yang sesuai dengan program yang diinputkan. hal ini menunjukkan algoritma perangkat lunak di pc untuk perhitungan interpolasi linier sudah berfungsi dengan baik dan dapat diimplementasikan dengan baik untuk positioning end effector mesin. efek dari error sistemik yang didapat dari pengujian linearitas tidak terlihat pada eksekusi intepolasi linier ini. hal ini dikarenakan nilai error pada semua sumbu sama sehingga nilai error terkompensasi. 99 101 103 105 107 109 1 14 27 40 53 66 79 92 pa nj an g ge ra kk an (m m ) percobaan kehasil pengukuran gerakan sumbu x positif rata-rata 99 101 103 105 107 109 1 14 27 40 53 66 79 92 pa nj an g ge ra kk an (m m ) percobaan kehasil pengukuran gerakan sumbu x negatif rata-rata 99 101 103 105 107 1 14 27 40 53 66 79 92 pa nj an g ge ra kk an (m m ) percobaan kehasil pengukuran gerakan sumbu y positif rata-rata 99 101 103 105 107 1 14 27 40 53 66 79 92 pa nj an g ge ra kk an (m m ) percobaan kehasil pengukura n gerakan sumbu y negatif rata-rata journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 41-50, 2011 p-issn 2087-3379 49 (a) (b) (c) (d) gambar 10. hasil pengujian interpolasi linear(a) pola linier yang diujikan, (b) input nc-code (c) hasil simulasi di komputer, (d) hasil gerakan aktual end effector. kemudian pada gambar 11 ditunjukkan hasil dari pengujian kemampuan interpolasi sirkular dengan menguji kemampun sistem untuk membentuk pola sirkular berbentuk cakra. pola sirkular (gambar 11a) diujikan dengan menginputkan nc-code ke sistem kendali (gambar 11b). hasil simulasi dari program yang diinputkan menunjukkan bentuk yang sesuai dan sempurna (gambar 11c). hal ini menunjukkan algoritma perangkat lunak di pc untuk perhitungan interpolasi sirkular sudah berjalan dengan baik. (a) (b) (c) (d) gambar 11. hasil pengujian interpolasi sirkular (a) pola sirkular yang diujikan, (b) input nc-code, (c) hasil simulasi di komputer, (d) hasil gerakan aktual end effector. desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine (roni permana saputra, anwar m., arif s., teguh p.p.) jmev 02 (2011) 41-50 50 sedangkan pada hasil pergerakan aktual end effector (gambar 11d), bagian yang dilingkari menunjukkan bentuk yang tidak sempurna dari bagian akhir interpolasi sirkular.hal ini terjadi dimungkinkan karena adanya error sistemik dari sistem seperti telihat pada pengujian linieritas dan repeatabilitas. pada pengujian interpolasi linier, efek ini tidak begitu berpengaruh, karena error sistemik pada masing-masing sumbu saling mengkompensasi. sedangkan pada pengujian interpolasi sirkular pengaruhnya sangat signifikan karena pada perhitungan sirkular menggunakan banyak rumus yang pada masingmasing perhitungannya dapat terjadi pembulatan sehingga pada bagian akhir proses interpolasi, nilai error tidak terkompensasi. v. kesimpulan pada penelitian ini, telah dihasilkan sistem pengendali router berbasis cnc untuk flame cutting machine dengan menggunakan personal computer. berdasarkan hasil dan analisis, gambar hasil simulasi yang ditampilkan pada layar simulasi sudah sesuai dengan program input yang dimasukkan baik untuk pola linier maupun pola sirkular. untuk pengujian pergerakan aktual pada end effector, hasil pengujian linearitas menunjukkan sistem memiliki linearitas yang baik dengan koefisien regresi linier 0,99, dan dari pengujian repeatabilitas diperoleh nilai akurasi positioning end effector rata-rata ±1,8 mm. pembuatan bentukbentuk linear sudah dapat dilakukan dengan baik. sedangkan pembuatan bentuk-bentuk sirkular masih belum sempurna yang kemungkinan disebabkan error sistemik yang belum terkompensasi. dari hasil yang diperoleh, dapat disimpulkan bahwa algoritma kendali yang dibuat sudah mampu berfungsi dengan baik. untuk implementasi di hardware sebenarnya, paremeterparameter dari faktor koreksi yang disebabkab error sistemik bisa dimasukkan dan diujikan untuk memperoleh hasil yang lebih baik terutama pada pembuatan pola-pola sirkular. ucapan terimakasih penulis mengucapkan terima kasih kepada bapak prof. dr. masno ginting, msc.yang telah banyak memberikan masukan, saran, dan ilmu dalam proses bimbingan penulisan karya tulis ini. terakhir penulis juga mengucapkan terima kasih kepada dr. eng.estiko rijanto selaku kepala bidang mekatronik, pusat penelitian tenaga listrik dan mekatronik lipi, yang telah memberikan bimbingan hingga terselesaikannya penulisan makalah ini. daftar pustaka [1] ulsoy, a.g. koren, y. 1993 control of machining processes, asme journal of dynamic systems measurement, and control 115 (1993) 301–307. [2] international standards organization,. iso 14649-1. datamodel for computerized numerical controllers : part 1, 2003. [3] 5 axis cnc routers, 3 axis routers, used cnc routers [online]. available: http://ww.machineks. com/ machines/cncplasma-flamecutters-9, diakses 28 februari 2011 [4] pabolu, v.k. srinivas, s.k.n.h.. design and implementation of a three dimensional cnc machine. international journal on computer science and engineering (ijcse), 02(08) : 2567-2570, 2010. [5] x.w. xu and newman, s.t.. 2006 making cnc machine tools more open, interoperable and intelligent—a review of the technologies. computers in industry, 57(2) :141-152 [6] pressman, rs. numerical control and computer-aided manufacturing, john wiley & sons, inc. new york, ny, usa, 1977. [7] mehta, nk. machine tool design, tata mcgraw hill company limited, new delhi. 1980. modeling of electric field around 100 mva 150/20 kv power transformatorusing charge simulation method mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.33-40 modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method noviadi arief rachman a,*, agus risdiyanto a, ade ramdan b aresearch centre for electrical power and mechatronics, indonesian institute of sciences kompleks lipi gd. 20, lt 2, jl. sangkuriang, bandung, indonesia bresearch center for informatics, indonesian institute of sciences kompleks lipi gd. 20, lt. 3, jl. sangkuriang, bandung, indonesia received 8 april 2013; received in revised form 21 may 2013; accepted 21 may 2013 published online 30 july 2013 abstract charge simulation method is one of the field theory that can be used as an approach to calculate the electromagnetic distribution on the electrical conductor. this paper discussed electric field modeling around power transformator by using matlab to find the safety distance. the safe distance threshold of the electric field to human health refers to who and sni was 5 kv/m. the specification of the power transformator was three phases, 150/20 kv, and 100 mva. the basic concept is to change the distribution charge on the conductor or dielectric polarization charge with a set of discrete fictitious charge. the value of discrete fictitious charge was equivalent to the potential value of the conductor, and became a reference to calculate the electric field around the surface contour of the selected power transformator. the measurement distance was 5 meter on each side of the transformator surface. the results showed that the magnitude of the electric field at the front side was 5541 v/m, exceeding the safety limits. keywords: electric field, charge simulation method, discrete charge, power transformator. i. introduction the electric field is an area that is still influenced by the electrical properties of a particular charge. an electric field presents in any region where a charged object experiences an electric force. this is a fancy way of saying that the only way we can conclude the present of electric field is by performing a test charge on that spot. in nature, the electric field generated bythe natural formation of electrical charges in the atmosphere associated with lightning. the electric field also exists due to the electrical equipment such as generators, transformators, transmission lines, distribution lines, and other electric and electronic equipment. however, the influence of an electric field around high voltage equipment is greater than the effect of electric fields that exist in nature. the existence of an electric field can indirectly cause problems to human health. it is depending on how powerful electric field and magnetic field exposed to the human body that can cause problems. population growth and technological change have led to increase in demand for electrical energy in larger quantities. this causes enhancement of electric field pollution in the urban and the work environments [1]. as it is stated before that the electric field can affect human health, it is also shown risk of cancer death in children living near the transmission line of high voltage [2]. in the 1960 and early 1970, the soviet union reported health effects experienced by their workers in high voltage switch yard. within several months the first 500 kv substations operated in the soviet union, maintenance workers complained about headaches, sexual potency reduction, and general ill health. the electric field was assumed to be responsible for the health complaints. personnel working with 500 kv and 750 kv lines were compared to the workers at 110kv and 220 kv substations. maximum intensities within the 500 kv and 750 kv switchyard were generally between 15 kv/m and 25 kv/m and biological effects were reported above 5 kv/m[3]. * corresponding author: tel: 022-2503055; fax: 022-2504773 e-mail: opay_23@yahoo.com http://dx.doi.org/10.14203/j.mev.2013.v4.33-40 n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 34 according to the who standard in 1990, boundary electric field allowed in the public areas for 24 hours per day is 5 kv/m [4].the indonesian government adopted the irpa and who recommendations which then included in the indonesian national standards (sni) concerning the safety limit for the influence of a 50-60 hz electric field, as shown in table 1. there is a lot of high voltage electrical equipment used in electric power systems one of which is the power transformator. power transformator is a device that is used to convert inbound electricity or voltage to a higher or lower value in order to accommodate the current flow needed for specific purposes. power transformator are a normal component in the power grids of many nations, making it possible to regulate the transfer of power to residences and commercial buildings without overloading the circuitry in those structures [5]. there are various levels of voltage used in power distribution systems, i.e. extra high voltage (500/150 kv), high voltage (150/70 kv), medium voltage (150/20 kv, 70/20 kv), and low voltage (20 kv/380 v). since the area around the power transformator has a large electric field, it is important to determine the safety distance from electric field effect for human health according to who and sni. this paper discusses the electric field that is produced by power transformator 100mva, 150/20 kv, 50 hz, from different sides of a surface with reference to each measurement distance of 5 meters. the modeling of electric field used the charge simulation method (csm) which applied to the matlab. the aims is to know the magnitude of electric field generated by influence of power transformator 100 mva, 150/20 kv, 50 hz, to a safe distance according to who standard. ii. basic theory a. electric field the electric field can be analyzed as an electrostatic field and magneto static, the electric field generated by ac-current is quasi-static [6]. it also produced by the voltage from electrical equipment. the strength of an electric field at a given point in space near an electrically charged object is proportional to the amount of charge on the object, and inversely proportional to the distance between the point and the object. electric fields strength are usually denoted by the symbol e, and it is a vector that has both magnitude and direction, as defined below [7]: 𝐸𝐸 = 𝑄𝑄 4𝜋𝜋𝜋𝜋 0𝑅𝑅2 . 𝛼𝛼𝑅𝑅 (1) where e : electric field strength (v/m) q : point charge (coloumb) 𝜋𝜋0 : permittivity dielectric r : distance between point charge and point p if described in cartesian coordinates, the electric field e of a point charged +q and lies in the coordinates of the point p (x, y, z) seen as vectors as shown in figure 1. if there are many charges on the different positions, the fields caused by n point charges can be written as follow [8]: 𝐸𝐸(𝑟𝑟) = 𝑄𝑄1 4𝜋𝜋𝜋𝜋 0 |𝑟𝑟−𝑟𝑟1 |2 . 𝒶𝒶1 + 𝑄𝑄2 4𝜋𝜋𝜋𝜋 0 |𝑟𝑟−𝑟𝑟2 |2 . 𝒶𝒶2 + ⋯ + 𝑄𝑄𝑛𝑛 4𝜋𝜋𝜋𝜋 0 |𝑟𝑟−𝑟𝑟𝑛𝑛 |2 . 𝒶𝒶𝑛𝑛 (2) where e(r) : electric field strength at point r (v/m) 𝑄𝑄𝑛𝑛 : point charge at point n (coloumb) 𝜋𝜋0 : permittivity dielectric r : the position of the observation point 𝑟𝑟𝑛𝑛 : the position of the sources 𝒶𝒶𝑛𝑛 : unit vector n. for homogeneous line charge with charge density per unit length 𝜌𝜌𝐿𝐿, then equation of the electric field above will be shown in eq. (3): 𝐸𝐸(𝜌𝜌) = 𝑄𝑄𝐿𝐿 2𝜋𝜋𝜋𝜋0𝜌𝜌𝐿𝐿 . 𝒶𝒶𝜌𝜌 (3) figure 1. the point pis the vector sum of the electric field due to charge+q table 1. the threshold electric field and magnetic field 50-60 hz no classification electric field (kv/m) 1 working area: working time short time 10 30 (0 2 hour/day) 2 public area : 24 hour/day few hour/day 5 10 n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 35 where e(𝜌𝜌) : electric field strength due to line charge (v/m) 𝑄𝑄𝐿𝐿 : line charge (coloumb) 𝜋𝜋0 : permittivity dielectric 𝜌𝜌𝐿𝐿 : length (m) b. charge simulation method (csm) charge simulation method (csm) is a method that used as an approach to distribution electric field problem induced by the charged conductor csm considered a practical method for calculating the fields and from its simplicity in representing the equipotential surfaces of the electrodes, its application to unbounded arrangements whose boundaries extend to infinity and its direct determination to the electric field [9]. the magnitudes of fictitious discrete charges are equivalent to the potential value of the conductor and used as a reference to calculate the electric field around the contour of the conductor surface that selected. once the values and positions of simulation charges are known, the potential and field distribution anywhere in the region can be computed easily [10]. in many practical problems of electrostatic, charge always located near a conductor. an electron released by an electrode and a power transmission line suspended over the earth conductor is an example of a commonly encountered. let’s review the case of a point charge near an infinite plane conductor, as shown in figure 3,in determining the potential +q with height d using poisson equation with z > 0, and boundary condition v = 0 at z = 0 and at infinity [11]. since there is no conductor, the solution to find the point charge in free space is as follows: 𝑉𝑉(𝑥𝑥, 𝑦𝑦, 𝑧𝑧) = 𝑞𝑞 4𝜋𝜋𝜋𝜋 � 1 �𝑥𝑥 2 +𝑦𝑦2 +(𝑧𝑧−𝑑𝑑)2 � (4) where 𝑉𝑉 : electric potential (v) 𝑞𝑞 : point charge (coloumb) 𝜋𝜋 : permittivity dielectric potential function v on equation (4) accomplishes poisson’s equation for z > 0 with boundary condition v = 0. however, the potential is not zero on z = 0. so the solution of case above can be shown in figure 4 as follow: the potential is expressed as: 𝑉𝑉 (𝑥𝑥, 𝑦𝑦, 𝑧𝑧) = 𝑞𝑞 4𝜋𝜋𝜋𝜋 � 1 �𝑥𝑥 2 +𝑦𝑦2 +(𝑧𝑧−𝑑𝑑)2 − 1𝑥𝑥2+𝑦𝑦2+𝑧𝑧+𝑑𝑑2 (5) the electro static potential in area z > 0 is super position of point charge +q and its image –q. once the potential function is obtained, the electric field can be calculated directly from the potential by using equation (6) [12]: 𝐸𝐸 = −∇𝑉𝑉 = 𝑞𝑞 4𝜋𝜋𝜋𝜋 � 𝑥𝑥�𝑥𝑥+ 𝑦𝑦�𝑦𝑦+ 𝑧𝑧̂ (𝑧𝑧−𝑑𝑑) (𝑥𝑥 2 + 𝑦𝑦2 +(𝑧𝑧−𝑑𝑑)2 ) 3 2� − 𝑥𝑥𝑥𝑥+ 𝑦𝑦𝑦𝑦+ 𝑧𝑧𝑧𝑧−𝑑𝑑𝑥𝑥2+ 𝑦𝑦2+𝑧𝑧+𝑑𝑑232 (6) c. two dimensional charge field simulation of two-dimensional charge field can be calculated with some line charges depicted on the x and y axis, with coefficients of line charge can be written by equation (7)[13]: 𝑃𝑃𝑛𝑛 = 1 2𝜋𝜋𝜋𝜋 1n � (𝑥𝑥−𝑥𝑥𝑛𝑛 )2 + (𝑦𝑦−𝑦𝑦𝑛𝑛 )2 (𝑥𝑥−𝑥𝑥𝑛𝑛 )2 + (𝑦𝑦+𝑦𝑦𝑛𝑛 )2 (7) where 𝜋𝜋 is permittivity, (𝑥𝑥𝑛𝑛 , 𝑦𝑦𝑛𝑛 ) is coordinate online charge which forms two-dimensional plane, and (x, y) is the coordinate of measurement point. in the gauss theorem explained that the line charge located at y = 0 (ground), the potential is zero. by adjusting the boundary conditions on the components of the x and y coordinates that form a two-dimensional plane, then the electric field at any point due to n charges that form two-dimensional plane can be calculated by the following equation: for n conductor, the potential of each is [11]: 𝑉𝑉1 = 𝜌𝜌1 2𝜋𝜋𝜋𝜋 1n 𝐿𝐿11′ 𝐿𝐿11 + ρ2 2πε 1n 𝐿𝐿12′ 𝐿𝐿12 + ρ3 2πε 1n 𝐿𝐿13′ 𝐿𝐿13 + ⋯ + ρ𝑛𝑛 2πε 1n 𝐿𝐿1𝑛𝑛′ 𝐿𝐿1𝑛𝑛 (8) figure 2. discretization charges on the rod conductor figure 3. a point charge +q near infinite conductor +q dx z n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 36 𝑉𝑉2 = 𝜌𝜌1 2𝜋𝜋𝜋𝜋 1n 𝐿𝐿21′ 𝐿𝐿21 + ρ2 2πε 1n 𝐿𝐿22′ 𝐿𝐿22 + ρ3 2πε 1n 𝐿𝐿23′ 𝐿𝐿23 + ⋯ + ρ𝑛𝑛 2πε 1n 𝐿𝐿2𝑛𝑛′ 𝐿𝐿2𝑛𝑛 (9) 𝑉𝑉3 = 𝜌𝜌1 2𝜋𝜋𝜋𝜋 1n 𝐿𝐿31′ 𝐿𝐿31 + ρ2 2πε 1n 𝐿𝐿32′ 𝐿𝐿32 + ρ3 2πε 1n 𝐿𝐿33′ 𝐿𝐿33 + ⋯ + ρ𝑛𝑛 2πε 1n 𝐿𝐿3𝑛𝑛′ 𝐿𝐿3𝑛𝑛 (10) 𝑉𝑉𝑛𝑛 = 𝜌𝜌1 2𝜋𝜋𝜋𝜋 1n 𝐿𝐿n 1′ 𝐿𝐿n 1 + ρ2 2πε 1n 𝐿𝐿n 2′ 𝐿𝐿n 2 + ρ3 2πε 1n 𝐿𝐿n 3′ 𝐿𝐿n 3 + ⋯ + ρ𝑛𝑛 2πε 1n 𝐿𝐿n𝑛𝑛′ 𝐿𝐿n𝑛𝑛 (11) the above equation can be written in matrix format follows: ⎣ ⎢ ⎢ ⎢ ⎡ v1 v2 v3 ⋮ vn⎦ ⎥ ⎥ ⎥ ⎤ = ⎣ ⎢ ⎢ ⎢ ⎡ p11 p12 p13 … p1n p21 p22 p23 … p3n p31 ⋮ pn 1 p32 ⋮ pn 2 p33 … p3n ⋮ ⋮ ⋮ pn 3 … pnn ⎦ ⎥ ⎥ ⎥ ⎤ . ⎣ ⎢ ⎢ ⎡ ρ1 ρ2 ρ3 ⋮ ρn⎦ ⎥ ⎥ ⎤ (12) or [𝑉𝑉] = [𝑃𝑃]. [𝜌𝜌] (13) thus, the line charge can be found using the equation: [𝜌𝜌] = [𝑃𝑃]−1. [𝑉𝑉] (14) where: v =potential phase p =matrix coefficients of maxwell 𝜌𝜌 =line charge d. application of (csm) for the computation of the electric field in power transformator for three-phase power transformator, where the number conductors more than one (r, s, t on the high voltage side and the r, s, t on the low voltage side), the magnitude of the potential at a point is the number of potential caused by their conductor on each side of the high voltage 150 kv and low voltage 20 kv potential transformator windings shown in figure 5. iii. methodology a. specification of measurement the specifications of power transformator that used in simulation are: voltage (v1(rms )) : 150,000 v (150kv) voltage (v2(rms )) : 20,000 v (20kv) transformator dimension: 2.5 x 1.5 x 1 m conductor distance to v1:1.25 m conductor distance to v2:0.5 m the software that used in the simulation is matlab 2007. electric field strength is expressed in the vertical axis and horizontal axis, each with real and imaginary parts, or with magnitude and phase angle. vertical axis of electric field strength: 𝐸𝐸𝑦𝑦 = 𝐸𝐸𝑟𝑟𝑦𝑦 + j𝐸𝐸𝑖𝑖𝑦𝑦 or 𝐸𝐸𝑦𝑦 = �𝐸𝐸𝑦𝑦� < φ𝑡𝑡𝑦𝑦 vertical axis of electric field strength: 𝐸𝐸𝑥𝑥 = 𝐸𝐸𝑟𝑟𝑥𝑥 + j𝐸𝐸𝑖𝑖𝑥𝑥 or 𝐸𝐸𝑥𝑥 = |𝐸𝐸𝑥𝑥 | < φ𝑡𝑡𝑥𝑥 voltage equations of each phase are: 𝑉𝑉𝑅𝑅1 = 𝑉𝑉01 √3 √2[cos 0 + 𝑗𝑗 sin 0] 𝑉𝑉𝑆𝑆1 = 𝑉𝑉01 √3 √2[cos −120 + 𝑗𝑗 sin −120] 𝑉𝑉𝑇𝑇1 = 𝑉𝑉01 √3 √2[cos 120 + 𝑗𝑗 sin 120] 𝑉𝑉𝑅𝑅2 = 𝑉𝑉01 √3 √2[cos 0 + 𝑗𝑗 sin 0] 𝑉𝑉𝑆𝑆2 = 𝑉𝑉01 √3 √2[cos −120 + 𝑗𝑗 sin −120] 𝑉𝑉𝑇𝑇2 = 𝑉𝑉01 √3 √2[cos 120 + 𝑗𝑗 sin 120] +q dx z -q d figure 4. a point charge +q and its image -q figure 5. front view of 3 phasa power transformator, 100 mva 150 kv/20 kv 1,5 m 1,25 m trafo 3 fasa, 150/20 kv 100 mva, 5o hz 2,5 m 1,5 m 0,5 m 1 3 phasa power transformator 150/20 kv, 100 mva, 50 hz n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 37 b. boundary conditions the boundary conditions are determined by adjusting the position of a point charge (discretization) with layout coordinates (x,y) on the boundary dimensions of the system to be measured with the following: measurement distance (h) : 5 m radius of phase conductor : 0.007727 m permittivity of air (𝜋𝜋0 ) : 1 permittivity of insulation (𝜋𝜋𝑟𝑟) : 4.5 the difference of permittivity will affect the magnitude of discrete charges around the area of measurement. since the permittivity of air (𝜋𝜋0 ) is less than the relative permittivity of the insulator (𝜋𝜋𝑟𝑟 ), the breakdown voltage will be greater. so that the electric field around the wire conductor will be larger than the electric field around the transformator. because there is some n charge in the system, then all the electric field of the system is calculated by equation (11). figure 6 is a flow chart, and the results of charge discretization on transformator will be the calculation of the electric field from all sides. from figure 7 can be explained as follows: a. coordinates (x, y) of front view: x = (-1.25, 0, 1.25, -1.25, 0, 1.25, -1.25, 0, 1.25, 1.25, 2.5, 0, -2.5, -1.25). y = (5, 5, 5, 5.75, 5.75, 5.75, 6.5, 6.5, 6.5, 7, 7, 7.35, 7.75, 7.75) b. coordinates (x, y) of 150 kv side: x = (-0.5, 0, 0.5, -0.5, 0, 0.5, -0.5, 0, 0.5, 0.5, 0, 0.5) y = (5, 5, 5, 5.75, 5.75, 5.75, 6.5, 6.5, 6.5, 7.75, 7.75, 7.75) c. coordinates (x, y) of 20 kv side: x = (-0.5, 0, 0.5, -0.5, 0, 0.5, -0.5, 0, 0.5, 0.5, 0, 0.5) y = (5, 5, 5, 5.75, 5.75, 5.75, 6.5, 6.5, 6.5, 7, 7, 7) d. coordinates (x, y) of above view: x = (-2.5, -1.25, 0, 1.25, 2.5, -2.5, -1.25, 0, 1.25, 2.5, -2.5, -1.25, 0, 1.25, 2.5). y = (5, 5, 5, 5, 5, 5.5, 5.5, 5.5, 5.5, 5.5, 6, 6, 6, 6, 6) coordinates of measurement point for all view measurement located at the point p (0,0). figure 6. flow chart of csm start plot the field distributions end n y input boundary conditions, parameters, and dimension assume the possitions of simulated charges and matching points compute the coefficient matrix [q] = [p] [v]-1 solve the simultaneous equations is the result reliable ? figure7. coordinates of fictitious charge (a) front view, (b) 150 kv-side, (c) 20 kv-side, (d) above view n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 38 iv. results and discussions the simulation has been done using the mat lab, the distribution of the electric field and equipotential lines from each side of the transformator three-phase 100 mva, 150/20 kv at a distance of 5 meters measurements are shown in figure 8 and figure 9. electric field distribution shown is the electric field strength, without indicating its direction, which is the vector sum of real and imaginary electric field in the direction x (horizontal) and y (vertical). the electric field generated from the front view of transformator has a maximum value at a distance of -2.6 m from the x-axis measurement point, with magnitude of electric field strength 6833 v/m, respectively. while at the measurement point (5 m), the resulting electric field is higher than who standard, amounting to 5541 v/m. according to equation (1), the farther the distance from the maximum value (x < -2.6 m and x > -2.6 m), the smaller the distribution of electric field is. the electric field generated from 150 kv-side of transformator has a maximum value at a distance of -3 m and 3 m from the x-axis measurement point, with magnitude of electric field strength, 3050 v/m (shown in figure 10 and figure 11). while at the measurement point, the resulting electric field is smaller than who standard, amounting to 1930 v/m. the farther the distance from the maximum value (x < -3 m and x > 3 m), the smaller the distribution of electric field is. the electric field generated from 20 kv-side of transformator has a maximum value at a distance of -3 m and 3 m from the x-axis measurement point, with magnitude of electric field strength 502 v/m, respectively (shown in figure 12 and figure 13). mean while, at the measurement point (5 m), the resulted electric field is smaller at the amount of 427 v/m. the farther the distance from the maximum value (x < -3 m and x > 3 m), the smaller the distribution of electric field. the electric field generated from above of transformator has a maximum value at a distance figure 10. simulated and measured electric field of 150kv-side figure 11. equipotential distribution of 150 kv-side figure 8. simulated and measured electric field in front viewof power transformator figure 9. equipotential distribution in front view of power transformator n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 39 of -0.5 m from the x-axis measurement point, with magnitude of electric field strength 9960 v/m, respectively (shown in figure 14 and figure 15). while at the measurement point, the resulting electric field is smaller, in the amount of 9890 v/m. the farther the distance from the maximum value (x < -0.5 m and x > 0.5 m), the smaller the distribution of electric field is. from all measurement results, the electric field around the wire conductor (r, s, t) without isolation is greater than the electric field around an isolated transformator wall, this is due to differences in the dielectric permittivity (𝜋𝜋) of a medium that causes the breakdown voltage differences that affect the magnitude of the electric field generated. the level of precision and measurement error in the simulation results depend on the determination of the location of the position discretization contour points to be measured as well as the boundary conditions as an important parameter in measuring and mapping the electric field. v. conclusion from the simulation results of the electric field in the area of the transformator, it can be concluded that simulation results shows the magnitude of the electric field generated in power transformator at the measurement point (5 m) is 5541 v/m. this can be considered that the safety limit of the electric field effect is in accordance with the who (world health organization), which is 5 kv/m. moreover, csm is efficient for calculating the electric field with fairly simple programs and less computing time. the surface of the electrodes and the polarization charges on the interface of different dielectrics are replaced by a set of discrete simulated charge. the types and positions of the simulated charges are predetermined. the magnitudes of these equivalent charges are determined by the boundary conditions on the collocation points of the boundary. hence, csm is one of the collocation methods and can be classified as an equivalent source method. figure 12. simulated and measured electric field of 20kv-side figure 13. equipotential distribution of 20kv-side figure 14. simulated and measured electric field from above of power transformator figure 15. equipotential distribution from above of power transformator n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 40 references [1] d. m. petković, et al., "the effect of electric field on humans in the immediate vicinity of 110 kv power lines," facta universitatis series: working and living environmental protection, vol. 3, pp. 63-72, 2006. [2] n. wertheimer and e. leeper, "electrical wiring configurations and childhood cancer," american journal of epidemiology, vol. 109, pp. 273-284, 1979. [3] v. p. korobkova, "influence of the electric field in 500 and 750 kv switchyards on maintenance staff and means for its protection," in the international conference on large high tension systems, paris, 1972. [4] s. azmi, "penggunaan fem (finite elemen method) dalam memetakan medan listrik pada permukaan isolator jenis pin dan post 20 kv dan saluran udara sekitarnya," jurusan elektro fakultas teknik, universitas diponegoro, semarang, 2011. [5] a. risdiyanto, et al., "effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection," mechatronics, electrical power, and vehicular technology, vol. 03, pp. 73-80, 2012. [6] s. n. indonesia, "ruang bebas dan jarak bebas minimum pada saluran udara tegangan tinggi (sutt) dan saluran udara tegangan ekstra tinggi (sutet)," ed. jakarta: badan standarisasi nasional, 2002. [7] william h. hayt, jr., ed., engineering electromagnetics. mcgraw-hill international book company, 1989. [8] m. f. iskander, ed., electromagnetic fields and waves. illinois: waveland press, 1992. [9] s. salama, et al., "comparing charge and current simulation method with boundary element method for grounding system calculations in case of multi-layer soil," international journal of electrical & computer sciences, vol. 12, pp. 17-24, august 2012. [10] a. ranković and m. s. savić, "generalized charge simulation method for the calculation of the electric field in high voltage substations," electrical engineering, vol. 92, pp. 69-77, 2010. [11] n. h. malik, "a review of charge simulation method and its application," ieee transaction on electrical insulation, vol. 24, pp. 3-20, 1989. [12] l. c. shen and j. a. kong, aplikasi elektromagnetik, 3 ed. vol. 2. jakarta: erlangga, 2001. [13] y. kato, "a charge simulation method for the calculation of two-dimensional electrostatic fields," fukui university of technology bulletin, vol. 03, 1980. n.a. rachman et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 33-40 41 introduction basic theory electric field charge simulation method (csm) two dimensional charge field application of (csm) for the computation of the electric field in power transformator methodology specification of measurement boundary conditions results and discussions conclusion mev mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.129-138 an experiment of ocular artifacts elimination from eeg signals using ica and pca methods arjon turnip a, *, iwan r. setiawan a , edy junaidi b , le hoa nguyen c a technical implementation unit for instrumentation development, indonesian institute of sciences, bandung, indonesia b indonesian university of education, department of physics, bandung, indonesia c dept. of electrical engineering, university of science and technology-the university of danang, vietnam. received 24 april 2014; received in revised form 10 november 2014; accepted 10 november 2014 published online 24 december 2014 abstract in the modern world of automation, biological signals, especially electroencephalogram (eeg) is gaining wide attention as a source of biometric information. eye-blinks and movement of the eyeballs produce electrical signals (contaminate the eeg signals) that are collectively known as ocular artifacts. these noise signals are required to be separated from the eeg signals to obtain the accurate results. this paper reports an experiment of ocular artifacts elimination from eeg signal using blind source separation algorithm based on independent component analysis and principal component analysis. eeg signals are recorded on three conditions, which are normal conditions, closed eyes, and blinked eyes. after processing, the dominant frequency of eeg signals in the range of 12-14 hz either on normal, closed, and blinked eyes conditions is obtained. keywords: eeg, eog, ica, pca, artifacts elimination. i. introduction the electrical activity produced by the brain is recorded by the electroencephalogram (eeg) using several electrodes placed on the scalp due to the effect of millions of neurons. signals characteristics vary from one state to another, such as wakefulness/sleep or normal. classically, five major brain waves can be distinguished by their frequency ranges: delta 0.5–4 hz, theta 4–8 hz, alpha 8–13 hz, beta 13–30 hz, and gamma 30–128 hz [1]. the eeg has been developed in various fields such as the medical field, the development of brain computer interface (bci) [2-6], etc. in the medical field eeg is used to diagnose diseases such as epilepsy, metabolic encephalopathy, and cerebral parenchyma infective. applications of eeg in the medical field are also able to determine the treatment to patients who have diseases related to nerves. in the development of bci, eeg signals are used to move the cursor in two dimensions [7,8], to design a virtual keyboard [9,10], to move the three-dimensional simulations [11-14], and to design a mobile robot for users who have a physical or mental deficiency [2-4]. the recorded eeg signals are not only the original signal according to the brain activity but also contaminated by noise signals such as eye blink, eye movement, muscular movement, line noise, etc. [1,15-17]. eye-blinks and movement of the eyeballs produce electrical signals that are collectively known as ocular artifacts (oa). the oa are pervasive problems in event-related potential (erp) research. the electric potentials created during saccades and blinks can be orders of magnitude larger than the eeg and can propagate across much of the scalp, masking and distorting brain signals. therefore, these noise signals are required to be separated from the eeg signals to obtain the accurate results. in a wide variety of research, artifact removal has been done by various methods. signal recording method performed with a variety of stimulus, such as moving the limbs, moving the eyes, etc. not only signal recording methods is * corresponding author. tel: +62-22-2503053 e-mail: jujhin@gmail.com http://dx.doi.org/10.14203/j.mev.2014.v5.129-138 a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 130 diverse, signal processing methods are also diverse. among of them is independent component analysis (ica) [15], principal component analysis (pca) [18], adaptive filters, autoregressive models [19], non-liniear pca [20], neural networks [21-25], wavelet denoising [1,15], gyroscope signal [16] etc. all of methods will be more powerfull when the artifacts are well identified. this paper describes an experiment to identify the artifacts with completely automated method for eliminating electro ocular contamination from eeg signals using statistical criteria applied to data components obtained using a blind source separation (bss) algorithm based on independent component analysis (ica) and principal component analysis (pca). the artifact is composed of horizontal and vertical eye movements, and eye blinks as indicated in table 1. in the experiment, the eeg signals when normal condition, closed eyes, and blinked eyes are recorded. ica attempts to separate the eeg signals recorded into statistically independent sources (components), and then reject it with regard to artifacts. pca is widely used for feature extraction by removing features that have no significant variance. ii. methods this experiment involved seven male subjects with age range from 20 to 25 year old. all subjects had never done recording the eeg signals before. eeg signals were recorded using the emotiv epoch system (figure 1(a)). eeg signals were recorded on a six channel is f7, f8, t7, t8, o1, and o2 as they relate to visual activity. electrode placement pattern is shown in figure 1(b). the first step of the experiment is the electrode preparation. electrodes are firstly smeared using an electrolyte liquid to improve conductivity of the electrode. this process takes approximately 5 minutes, following by the pairing the emotiv epoch system on the subject and adjust the location of the electrodes on the scalp to record. experiments carried out with three stimuli, i.e., normal conditions, closed eyes, and blinked eyes. data recording scenarios is shown in table 1. prior to ocular artifacts elimination using bss based on ica and pca, a preprocessing operations filter fir chebyshev type ii was carried out. flowchart of signals processing is shown in figure 2. a. independent component analysis ica is one of algorithms group to solve the problem of blind source separation. independent component analysis can be used to estimate based on independent information and this makes it possible to separate the original signals from their mixtures. table 1. data recording scenarios time (second) stimulus activity 0-20 + normal 20-40 ↓ closed eyes 40-41 ↑ blinked eyes 41-45 + normal 45-46 ↑ blinked eyes 46-50 + normal 50-51 ↑ blinked eyes 51-55 + normal 55-56 ↑ blinked eyes 56-60 + normal (a) (b) figure 1. (a) emotiv epoch system; (b) electrode placement pattern a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 131 the observed signal is denoted by x with elements , d and the original signal is denoted by s with elements , and a is the mixing matrix . with the vector notation, mixing models can be written as follows [20, 21]: (1) estimating the independent components can be accomplished by finding the right linear combinations of the mixture variables, with invert the mixing as follow [20, 21]: (2) thus, to estimate one of the independent components, we can consider a linear combination of the . assume a new vector as ∑ (3) where b is a vector to be determined [20, 21]. ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) (4) ( ) ( ) ( ) ( ) by substituting equation (1) to equation (3) it can be written . thus, y is a certain linear combination of the , where is a coefficient matrix denoted by q [20, 21]. so the equation (3) can be obtained ∑ (5) if b was one of the rows of the inverse of a, this linear combination would actually equal one of the independent components. in that case, the corresponding q would be such that just one of its elements is 1 and the others are zero. in practice, b and a cannot be determined but we can find an estimator that gives a good approximation. the fundamental idea here is that since a sum of two independent random variables is more gaussian than the original variables, is usually more gaussian than any of the and becomes the least gaussian when it in fact equals to one of the . in this case, obviously only one of the elements of q is nonzero. in practice the values of q is unknown, but by the definition of q. such a vector would necessarily correspond to a , which has only one nonzero component. this means that equals to one of the independent components [20]. b. principal component analysis the starting point for pca is a random vector x (i.e., ( ) ( )) with n elements. typically the elements of x are measurements like pixel gray levels or values of a signal at different time instants. it is essential in pca that the elements are mutually correlated, and there is thus some redundancy in xx. in the pca transform, the vector x is first centered by subtracting its mean [20]: * + (6) the mean in this practice is estimated from the available sample ( ) ( ). assume in the following that the centering has been done and thus * + . next, x is linearly transformed to another vector y with m elements (m < n) so that the redundancy induced by the correlations is removed. this is done by finding a rotated orthogonal coordinate system such that the elements of x in the new coordinates become uncorrelated. at the same time, the variances of the projections of x on the new coordinate axes are maximized so that the first axis corresponds to the maximal variance, the second axis corresponds to the maximal variance in the direction orthogonal to the first axis, and so on. in mathematical terms, consider a linear combination [20, 21]: ∑ , (7) where the vector x is the elements . the are scalar coefficients or weights of an ndimensional vector , and denotes the transpose of . the factor is called the first principal component of x when the variance of is maximally large. because of the variance figure 2. flowchart of signals processing a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 132 is depends on both the norm and orientation of the weight vector , impose the constraint that in the norm of is constant become equal to 1 in practice. thus we look for a weight vector maximizing the pca criterion as follow ( ) * + {( ) } * + (8) so that ‖ ‖ . the * + is the expectation over the (unknown) density of input vector x. the matrix is the n x n covariance matrix of x given for the zero-mean vector x with the correlation matrix as * + (9) it is well known from basic linear algebra that the solution to the pca problem is given in terms of the unit-length eigenvectors of the matrix . the ordering of the eigenvectors is such that the corresponding eigenvalues satisfy . the solution equation (8) is given by . thus the first principal component of x is . the criterion in equation (8) can be generalized to m principal components, with m any number between 1 and n. denoting the m-th ( ) principal component by , with the corresponding unit norm weight vector, the variance of is now maximized under the constraint that is uncorrelated with all the previously found principal components: * + (10) note that the principal components have zero means because of: * + { } (11) the condition (10) yields: * + {( )( )} (12) for the second principal component, we have the condition as follow (13) it is known that , thus looking for maximum variance * + {( ) } in the subspace orthogonal to the first eigenvector of . the solution is given by . likewise, recursively it follows that . thus the k-th principal component is . iii. result preparatory to an analysis of the ocular elimination from eeg signals, actual signals were recorded in a six-channel (f7, f8, t7, t8, o1, and o2) configuration as they relate to visual activity. the raw data (see figure 3) were first pre-processed using a filter fir chebyshev type figure 3. recorded eeg signal from the 1 st subjects a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 133 ii with cut-off frequencies of 0.5 (i.e., to remove the trend from low frequency bands) to 49 hz (i.e., to remove unimportant information from high frequency bands), respectively (figure 4). the low and the high frequency bands are clearly remove in figure 4 compared to figure 3 and the amplitude of eeg signals turn out to be 20-100 μv. all channels except channel f8 are highly contaminated by medium frequency bands. it can be seen that the signals were corrupted by noises. since the original eeg signal to the eeg power (noise) ratio is small, a method of extracting the brain activity component from the eeg is desirable. one way of gaining further figure 4. filter eeg signal using bpf figure 5. clean eeg signal using ica a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 134 insights into eeg signals is by applying bss based on ica and pca techniques. figure 5 and figure 6 shows the feature extraction results of the bss base on ica and pca, respectively. the visually comparing the time domain plots, it is clear that the both algorithm reduces the amplitude of the ocular artifact while preserving the background eeg. the extracted signals using both metods show the similarities of the signals propagation in each channel with the same condition of stimulus. the similarities patterns are given in the red color marks. in the closed eyes condition, the amplitude is a little bit higher compare with others condition. this results indicated that other conditions are more contaminated by noise. the other results about the highly degradation of the amplitude (from 100 μv to 10 μv) also indicated in the extracted eeg signals. compared with the ica method, the extracted eeg signals using pca method produces eeg signals with larger amplitude as shown in figure 6. this indicates that the signal is not completely separated from the mixture. although the signals were still corrupted by noises (manifested as the high amplitudes of the artifacts in some sessions), the behaviors of the extracted signals clearly represented the brain activity components. in order to show the visually performance of the extracted eeg signals, the brain mapping process is applied. the brain maps using both methods is given in figure 7. the magnitude around 500 ms after given stimulus of each extracted signals are ploted in 2-d maps. the active brain regions that have been separated on any channels are indicated with a yellow to red. the red color indicated the higher brain activity and the blue color indicate the lower brain activity. the brain maps using pca method indicates that the ocular artifacts are not perfectly separated (specially on channels f8 and o1) compared with the ica method. figure 7. (a) brain maps using ica, (b) brain maps using pca figure 6. clean eeg signal using pca a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 135 other results about average eeg spectra based on three conditions stimulus (i.e. normal, closed, and blinked eyes condition) in the experiment using both methods are given in figure 8 and figure 9, respectively. the higher amplitude using both method is achieved in the range frequencies of 12-14 hz. this results indicate that both method are success in eliminate the ocular artifacts without losing of important information on the recorded eeg signals. the ica method presents the amplitude: normal and blinked eyes condition about 1-1,5 μv while closed eyes condition about 5 μv. the pca method present the amplitude: normal and blinked eyes condition about 1.3-1.4 μv while closed eyes condition about 18 μv. the differences in the level of amplitude between both methods indicate the ability of the separation of the noise from the brain activity in the recorded eeg signals. dominant frequency figure 8. average eeg spectra of each channels on normal, closed, and blinked eyes condition extracted using ica figure 9. average eeg spectra of each channels on normal, closed, and blinked eyes condition extracted using pca a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 136 and amplitude of each condition for all subjects are shown in table 2 and table 3 using ica and pca methods, respectively. table 2 and table 3 show the brain waves spectrum of all subjects (s) in the frequency range about 11-16 hz. there are two subjects with high frequency range under normal and blinked eyes conditions that are the 4 th and 6 th subject which is in the frequency range about 2128 hz. there are two possible reasons for these results: the subject was not focus on the given stimulus and or was not relaxed during the experiment. overall results of the signal processing show the average frequency of normal condition, closed eyes, and blinked eyes more dominant in the frequency ranges of 12-14 hz (alpha-beta). when the brain on alpha waves, it shows the subjects in a relaxed state, and beta waves showed that subjects in a state of full awareness, it is accordance with the current state of the recording signal. there are some subjects that have a larger frequency (high beta) than the other. when subjects are at high beta conditions, it indicate that the subjects were thinking on other activities or not to focus on the given stimulus. iv. conclusion an experiment for the elimination of eye blink artifact from eeg signal using blind source separation algorithm based on independent component analysis and principal component analysis is reported. eeg signals are recorded on three conditions, which are normal conditions, closed eyes, and blinked eyes. after processing, the higher amplitude of eeg signals in the range of 12-14 hz either on normal, closed, and blinked eyes conditions is obtained. both methods are successfully eliminate the ocular artifacts without losing of important information on the recorded eeg signals. acknowledgment this research was supported by the thematic program (no. 3425.001.013) through the bandung technical management unit for instrumentation development (deputy for scientific services) and the competitive program (no. 079.01.06.044) through the research center for metalurgy (deputy for earth sciences) funded by indonesian institute of sciences, indonesia. table 2. frequency (hz) and brainwave amplitude (µv) in normal, closed, and blinked eyes conditions using ica s normal closed eyes blinked eyes f (hz) a (µv) f (hz) a (µv) f (hz) a (µv) 1 13 1,143 13 5,029 13 1,575 2 15 0,918 11 2,691 14 1,035 3 16 1,290 11 4,001 16 1,014 4 27 0,935 12 1,015 15 0,725 5 13 0,839 12 4,763 13 0,912 6 22 1,017 12 4,948 19 0,739 7 13 0,520 12 5,830 13 0,371 table 3. frequency (hz) and brainwave amplitude (µv) in normal, closed, and blinked eyes conditions using pca s normal closed eyes blinked eyes f (hz) a (µv) f (hz) a (µv) f (hz) a (µv) 1 13 1,355 13 18,087 14 1,318 2 14 1,603 11 6,488 13 2,326 3 16 0,468 12 2,721 12 0,312 4 13 1,496 12 9,911 13 1,323 5 12 4,144 12 14,899 12 3,063 6 11 0,475 12 14,538 9 0,465 7 12 4,296 12 17,706 12 4,070 a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 137 references [1] r. r. vázquez, h. v. pérez, r. ranta, v. d. louis, d. maquin, and l. maillard, “blind source separation, wavelet denoising and discriminant analysis for eeg artefacts and noise cancelling,” biomedical signal processing and control, vol. 7, pp. 389–400, 2012. [2] l. bi, x.-a. fan, and y. liu, “eeg-based brain-controlled mobile robots: a survey,” ieee transactions on human-machine systems, vol. 43, no. 2, pp. 161-176, 2013. [3] p. f. dieza, s. m. t. müller, v. a. mut, e. laciar, e. avila, t. f. b. filho, and m. s. filho, “commanding a robotic wheelchair with a highfrequency steady-state visual evoked potential based brain–computer interface,” medical engineering & physics, vol. 35, pp. 1155–1164, 2013. [4] a. c. lopes, g. pires, and u. nunes, “assisted navigation for a brain-actuated intelligent wheelchair,” robotics and autonomous systems, vol. 61, pp. 245–258, 2013. [5] a. turnip, d. soetraprawata, and d. e. kusumandari, "a comparison of eeg processing methods to improve the performance of bci,” international journal of signal processing systems, vol. 1, no. 1, 2013. [6] a. turnip, and d. e. kusumandari, “improvement of bci performance through nonlinear independent component analisis extraction,” journal of computer, vol. 9, no. 3, pp. 688-695, march 2014. [7] b. z. allisona, c. brunner, c. altstätter, i. c. wagner, s. grissmann, and c. neuper, “a hybrid erd/ssvep bci for continuous simultaneous two dimensional cursor control,” journal of neuroscience methods, vol. 209, pp. 299– 307, 2012. [8] y. li, j. long, t. yu, z. yu, c. wang, h. zhang, and c. guan, “an eeg-based bci system for 2-d cursor control by combining mu/beta rhythm and p300 potential,” ieee transactions on biomedical engineering, vol. 57, no. 10, pp. 2495-2504, 2010. [9] l. mayaud, s. filipe, l. pétégnief, o. rochecouste, and m. congedo, “robust braincomputer interface for virtual keyboard (robik): project results” irbm, vol. 34, pp. 131–138, 2013. [10] r. b. ashari, i. a. al-bidewi, and m. i. kamel, “design and simulation of virtual telephone keypad control based on brain computer interface (bci) with very high transfer rates,” alexandria engineering journal, vol. 50, pp. 49–56, 2011. [11] a. s. royer, a. j. doud, m. l. rose, and b. he, “eeg control of a virtual helicopter in 3dimensional space using intelligent control strategies,” ieee transactions on neural systems and rehabilitation engineering, vol. 18, no. 6, pp. 581-589, 2010. [12] a. akce, m. johnson, o. dantsker, and t. bretl, “a brain–machine interface to navigate a mobile robot in a planar workspace: enabling humans to fly simulated aircraft with eeg,” ieee transactions on neural systems and rehabilitation engineering, vol. 21, no. 2, pp. 306-318, 2013. [13] g. g. gentiletti, j. g. gebhart, r. c. acevedo, o. yá˜nez-suárez, and v. medina-ba˜nuelos, “command of a simulated wheelchair on a virtual environment using a brain-computer interface,” irbm, vol. 30, pp. 218–225, 2009. [14] h.-j. hwang, k. kwon, and c.-h. im, “neurofeedback-based motor imagery training for brain–computer interface (bci),” journal of neuroscience methods, vol. 179, pp. 150–156, 2009. [15] g. geetha, and s. n. geethalakshmi, “artifact removal from eeg using spatially constrained independent component analysis and wavelet denoising with otsu’s thresholding technique,” procedia engineering, vol. 30, pp. 1064 –1071, 2012. [16] s. o’regan, s. faul, and w. marnane, “automatic detection of eeg artefacts arising from head movements using eeg and gyroscope signals,” medical engineering & physics, vol. 35, pp. 867– 874, 2013. [17] s. o’regan, and w. marnane, “multimodal detection of head-movement artefacts in eeg,” journal of neuroscience methods, vol. 218, pp. 110–120, 2013. [18] t. liu, and d. yao, “removal of the ocular artifacts from eeg data using a cascaded spatiotemporal processing,” computer methods and programs in biomedicine, vol. 83, pp. 95–103, 2006. [19] v. lawhern, w. d. hairston, k. mcdowell, m. westerfield, and k. robbins, “detection and classification of subject-generated artifacts in eeg signals using autoregressive models,” journal of neuroscience methods, vol. 208, pp. 181–189, 2012. [20] a. cichocki and s.-i. amari, blind decorrelation and sos for robust blind identification. adaptive blind signal and image processing, chapter 4, (2002). [21] a. turnip, k.-s. hong, and m.-y. jeong, "realtime feature extraction of p300 component using adaptive nonlinear principal component analysis," journal of biomedical engineering online, 10:83, 2011. [22] d. soetraprawata, and a. turnip, "autoregressive integrated adaptive neural networks classifier for eeg-p300 classification," journal of mechatronics, electrical power and vehicular technology, vol. 4, no. 1, pp. 1-8, 2013. [23] h.-a. t. nguyen, j. musson, f. li, w. wang, g. zhang, r. xu, c. richey, t. schnell, f. d. mckenzie, and j. li, “eog artifact removal a. turnip et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 129-138 138 using a wavelet neural network,” neurocomputing, vol. 97, pp. 374–389, 2012. [24] a. turnip, and d. soetraprawata, "performance of eeg-p300 classification using backpropagation neural networks," journal of mechatronics, electrical power and vehicular technology, vol. 4, no. 2, pp. 81-88, 2013. [25] a. turnip, and k.-s. hong, "classifying mental activities from eeg-p300 signals using adaptive neural network," international journal of innovative computing, information and control (ijicic), vol. 8, no. 7, 2012. j. mechatron. electr. power veh. technol 06 (2015) 31–38 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.31-38 prediction model of battery state of charge and control parameter optimization for electric vehicle bambang wahono a, *, kristian ismail a , harutoshi ogai b a research centre for electrical power and mechatronics, indonesian institute of sciences jl. sangkuriang komplek lipi gedung 20 lantai 2 bandung, 40135, indonesia b graduate school of information, production and systems, waseda university 2-7 hibikino, wakamatsu-ku, kitakyushu, fukuoka 808-0135, japan received 9 september 2014; received in revised form 23 february 2015; accepted 2 march 2015 published online 30 july 2015 abstract this paper presents the construction of a battery state of charge (soc) prediction model and the optimization method of the said model to appropriately control the number of parameters in compliance with the soc as the battery output objectives. research centre for electrical power and mechatronics, indonesian institute of sciences has tested its electric vehicle research prototype on the road, monitoring its voltage, current, temperature, time, vehicle velocity, motor speed, and soc during the operation. using this experimental data, the prediction model of battery soc was built. stepwise method considering multicollinearity was able to efficiently develops the battery prediction model that describes the multiple control parameters in relation to the characteristic values such as soc. it was demonstrated that particle swarm optimization (pso) succesfully and efficiently calculated optimal control parameters to optimize evaluation item such as soc based on the model. keywords: soc; stepwise method; multicollinearity; electric vehicle; particle swarm optimization. i. introduction rising crude oil price and worldwide awareness of environmental issues have resulted in increased development of energy storage systems and electric vehicle (ev), which are essential for energy saving and environment protection [1]. batteries get widely used in the electric car or hybrid power system. state of charge (soc) estimation is a fundamental challenge for battery use. the soc of a battery, which is used to describe its remaining capacity, is a very important parameter for a control strategy [2]. there are several methods to estimate battery soc. in this paper, direct measurement is used to estimate the battery soc. direct measurement method refers to some physical battery properties like terminal voltage, current, and temperature. there are two kinds of direct measurement methods which are open circuit voltage and terminal voltage. open circuit voltage method is a method where voltage is not connected to any load in a circuit. this voltage has a linear relationship to the soc but this condition only occurs on lead-acid battery [3]. because the relation between open circuit voltage and soc differs among batteries there is a problem in this relationship. to estimate soc accurately, it should be measured with terminal voltage method. terminal voltage method is based on the terminal voltage drops from internal impedances when the battery is discharging, so the electromotive force (emf) of battery is proportional to the terminal voltage. since the emf of battery is approximately proportionally linear to the soc, the terminal voltage of battery is also approximately linear proportional to the soc [4]. the terminal voltage method has been employed at different discharge currents and temperatures [4]. in this paper direct measurement was done using terminal voltage method. the advantages of this method are: it can be applied to any battery type with any discharger current profile, it * corresponding author. phone: +62-22-2503055 fax. +6222-2504773 e-mail: bambangwahono80@ yahoo.co.id, bamb053@lipi.go.id b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 32 offers low complexity of the algorithm, and it can be used as a real-time electro-analysis tool for battery diagnosis [5]. although some physical battery properties as control parameters were used to estimate the battery soc, a method which improves the performance of battery is required. this paper presents a construction of a battery soc prediction model and an optimization method of the model to control the number of control parameters appropriately in accordance with the soc as the battery output objectives. soc is an important parameter for estimating residual capacity of the battery. an accurate soc estimation can enhance the performance of the battery and increase the security of the electric vehicle. stepwise method considering multicollinearity was applied to construct the polynomial battery model that describes the multiple control parameters in relation to the characteristic values such as soc. in order to improve the performance of battery, particle swarm optimization (pso) was applied in this prediction model. pso was applied to calculate optimal battery control parameters and optimize evaluation item such as soc based on the model. ii. construction of the model using stepwise method a. stepwise method some battery properties can be used to estimate the value of the battery soc. however, a new method is needed in order to improve the efficiency and performance of the battery. the better the estimation of soc the higher the battery performance will be. one method which can be used to estimate the soc battery is stepwise method. in this study, stepwise method considering multicollinearity was applied to build battery soc model. to enable the construction of a good mathematical model, stepwise method employs the addition and subtraction of variables taken from a multi linear model considering their importance level in regression [6]. this method uses statistical method to remove the pleonastic variables. in this research, good model was obtained using a method that enables less variable inputs and less computation. this method actually can choose the most significant variables to be incorporated in model construction. stepwise method is a combination of backward elimination and forward selection. backward elimination method works by issuing one by one independent variable that is not significant and carrying it out continuously until no insignificant variables left. on the contrary, forward selection method starts from zero variables (empty model), then one by one variable input is added until certain criteria are met. the first variable inputted in stepwise method is one that has the highest correlation and significance. variables entered next is one with the highest partial correlation and still significant. after certain variables entered into the model, other variables in the model are evaluated. if there is a variable that is not significant, the variable will be removed. b. construction of mathematical model based on the experiment data 1x 7x as control parameters (input) and 1y that represents the characteristic value of the optimization objective (output), the mathematical model was built using stepwise method. this model represents the value of a response variable as a multilinear function of one or more independent variables in 1 st order and 2 nd order: i p i iii p ji jiij p i iii exxxxy    1 2 1 0  (1) where 𝑦𝑖 is response variable in observation x , o  is coefficient constant, i  is coefficient of the ix variable, ij is coefficient of the ix and jx variable, ii is coefficient of the 2 nd order ix variable, p is total number of variables, and ie is error term. the model in equation (1) was estimated by least squares method, which yields parameters estimate such that the sum of squares of errors is minimized. in order to select a clause effectively in presumption, one explaining variable redefines about all the 2 nd order respectively. for example, 1u redefines 2 1x and 2u redefines 21 xx . thus, the polynomial model selects the combination of an explaining variable effectively in presumption to be constituted by the stepwise method afterward. the resulting prediction equation is:    p i iii p ji jiij p i iii xxxxy 1 2 1 0 ˆˆˆˆˆ  (2) where the variables are defined as in equation (1) except that “^” denotes estimated values. the error term in equation (1) is unknown because the b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 33 true model is unknown. once the model has been estimated, the regression residuals are defined as: iii yye ˆˆ  (3) where iy is the observed value of response in observations i and iŷ is the predicted value of response in observation i . then, the sum of squared residuals (sse) equation is:    n i iesse 1 2 ˆ (4) where n is the number of observations. the sum of squared regression (ssr) equation is:    n i ii yyssr 1 2 )ˆ( (5) where iy is the mean of the iy values. the sum of squared total (sst) equation is:    n i ii yyssrssesst 1 2 )( (6) sst sse r  1 2 (7) )1/( /   pnsse pssr f (8) where f is the statistic value. the correlation coefficient r indicates the matching level of the calculation data by the regression equation and the original data, the result is better when r is closer to 1. statistic values indicate the significance of the regression equation, whose values comply f distribution. c. multicollinearity the procedure of the stepwise method generally has three steps. first, an initial regression model is determined. second, the procedure is repeated until produces a good model by adding and removing the corresponding variable in accordance with the f -test [7]. third, the search is stopped when the response variables that meet the stepping criterion are no longer exist, or when the step of iteration has reached a specified maximum number. the flowchart of the stepwise method is shown in figure 1. stepwise is one method to solve a case of multicollinearity, a condition where there is a strong correlation between independent variables. multicollinearity does not cancel the model in terms that the estimation value of the equation may still be good as long as the estimations are based on combinations of independent variables within the same multivariate space used to calibrate the equation. one of negative effects of multicollinearity is the values of the individual regression coefficients may change radically by adding or removing independent variable in the equation. the variance inflation factor (vif) is a statistic factor used to identify multicollinearity case in a matrix of independent variables [8]. it is used to mention the effect of multicollinearity on the variance of estimated regression coefficients. multicollinearity depends not only on the bivariate correlation between pairs of independent variable, but also on the multivariate predictability of any one variable from other variables. finally, the vif is based on the multiple correlation coefficients of each variable in multivariate regression on all the other variables: 2 1 1 r vif   (9) iii. particle swarm optimization a. particle swarm optimization technique the battery soc prediction model which was built by stepwise method was not optimized yet. in this paper, pso was applied to the prediction model to calculate optimal battery control parameters and optimize soc based on the model. pso is one of the optimization methods inspired by the behavior of herd animals such as fish movement (school of fish), herbivore animals (herd), and birds (flock) where each animal object is simplified into a particle. a particle in space has a position that is encoded as a vector coordinates. this position vector is considered as a state of being occupied by a particle in the search space. each position in the search space is an alternative solution that can be evaluated using the objective function. each particle moves with a specific velocity. the pso characteristic is the particle velocity regulated heuristically and probabilistically. if a particle has a constant speed then the position of a particle visualized trail will form a straight line. with the external factors that distort the line which moves the particle in the search space it is expected that the particles can lead, approach, and ultimately achieve optimal point. external factors mean, among others, the best position ever visited by the particle, the best position throughout the particles (each particle is assumed to know the best position of every other particles), and the factor of creativity to explore. b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 34 first described by james kennedy and russell c. eberhart in 1995 [9], pso is similar to the genetic algorithm (ga), since it randomly generates a population of solutions. however, pso still differs from ga in three aspects. first, it randomly initializes velocities for the first loop. second, solutions are named as “particles” which are restricted with a search space [10]. the search figure 1. model-building procedure of stepwise regression (adopted from [11]) b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 35 points are known as particles, indicated as particles positions and velocities with certain dimensions. third, a particle regulates its velocity according to the best position of its own experience and the global best position of all particles in each iteration [12, 13]. b. the basic algorithm of pso here is the analogy of pso mimicking animal herd: a random group of birds looking for food in an area. in this area, there is only a piece of food that will be searched. in each iteration of pso, the whole group of birds does not know where the food is but they know the food distance. so, what is the best strategy to find this food? one effective way to find this food is by following the bird closer to the food [14]. pso algorithm has two main operators: velocity update and position update. the procedure of pso algorithm is as follows: first, define a set of random particles n (each particle represents a possible solution to the optimization problem). second, establish the position of each particle j in iteration i   ix j and the velocity of each particle   iv j . third, calculate the value of each particle objective function f   ix j based on formula and model that have been determined in accordance with the optimization problem. fourth, for each particle, compare the value of objective function f   ix j with the best value has been achieved jbestp , (local best) if f   ix j < jbestp , then jbestp , will be replaced with f   ix j . fifth, for each particle, compare the value of objective function f   ix j with the best value achieved in the population bestg (global best). if f   ix j < bestg , to bestg , then replace bestg with f   ix j . sixth, based on the similarities in step 4 and 5, velocity   ijv and the position of the particle   ix j will change. the formula of velocity change is   ijv :           njixgrc ixprciwviv jbest jjbestjj ,...,2,1;1 11 22 ,11   (10) where w is called the inertia weight; this value is usually a linear decreasing value from 0.9 to 0.4. the acceleration constants 1c and 2c are the cognitive (individual) and social (group) learning rates respectively, and 1r and 2r are uniformly distributed random numbers in the range 0 and 1. the parameters 1c and 2c denote the relative importance of the memory (position) of the particle itself to the memory (position) of the swarm. the values of 1c and 2c are usually assumed to be two so that 11rc and 22 rc ensure that the particles would overfly the target about half of the time. the formula of position change is   ijx :       njivixix jjj ,...,2,1;1  (11) finally, check the convergence of the final condition. if the final condition of all particles position has been converged (the maximum iteration or looping value has reached the optimum value) then the iteration stops. if this condition is not reached then step 3 is repeated. iv. experiment research centre for electrical power and mechatronics has built test vehicle which is able to monitor several parameters like voltage, current, velocity, temperature, and soc [15]. the monitored data will be stored and displayed on board computer. components layout and graphic user interface (gui) are shown in figure 2 and 3. the control parameters are set in table 1 and the optimization objectives are listed in table 2. the number of experiment data used to create the model is 202 data and number of experiment data used to test the model is 60 data. figure 2. components layout figure 3. gui from onboard computer b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 36 v. result and discussion a. prediction and experiment result of soc model the results of the predicted value and experiment value of soc employing stepwise method without multicollinearity and using multicollinearity are shown in figure 4 and 5. in figure 4, the dotted line is experiment value and solid line is predicted value. the multiple correlation coefficient is 0.99752 but this model uses 35 variables and f value is 951.0478. the polynomial model of soc constructed by stepwise method without multicollinearity is: 2 776 2 6 7565 2 574 6454 2 473 6353 43 2 3 7262 5242 32 2 2 7161 5141 3121 2 176 543 211 005916.000149.00052275.7 00087659.00053938.1 0051506.301876.0 00066276.000019401.0 00064325.00075704.6 0075209.60071354.4 0061774.20109916.5 0011794.00054893.4 00011109.000015986.0 0081122.80062204.2 0057077.20064171.2 0063654.40050438.1 0085767.20064268.3 0086609.30237.1040672.0 02037.014627.000012173.0 011223.00004689.04602.7 xxxxe xxxxe xexx xxxx xxxe xxexxe xxexe xxxxe xxxx xxexe xxexxe xxexxe xxexxe xexx xxx xxy                 (12) in figure 5, the multiple correlation coefficient is only 0.99492 but this model only uses nine variables and f value is higher i.e. 2083.5822. it shows higher accuracy. the polynomial model of soc constructed by stepwise method considering multicollinearity is: 2 5 54 2 4 7161 51 2 1 541 0052797.1 00019556.000058728.0 0056051.10067938.4 0062566.30082148.7 011122.0056749.042384.0 xe xxx xxexxe xxexe xxy      (13) based on the polynomial model of soc in equation (13) it can be explained that some of the control parameters that give an effect significantly to the prediction of soc are load current  1x , electronic temperature  4x , and vehicle velocity  5x . internal resistance is affected by changes in the voltage drop during the load current. the change of internal resistance is linear with value of soc. electronic temperature is the temperature rise in power electronic components that is highly influenced by load current through it so that it indirectly affects the change of soc. load current is one of the significant control parameters which affect the prediction of soc. load current is also influenced by vehicle table 1. control parameter control parameter meaning unit variation range x1 load current ampere 108-612 x2 batteries voltage volt 50-74 x3 electric motor speed rpm 1,4226,696 x4 electronic temperature o c 60-69 x5 vehicle velocity km/h 7.34480.784 x6 time sec 4-67 x7 gear 1-4 table 2. optimization objective optimization objective y1 meaning state of charge unit % figure 4. the prediction and experiment value of soc based on stepwise method without multicollinearity figure 5. the prediction and experiment value of soc based on stepwise method considering multicollinearity b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 37 velocity in which the test is done on a flat road. the greater the load current the smaller the vehicle velocity will be. indirectly, vehicle velocity can affect the value of soc. b. the optimization of battery control parameter the important factor to get the optimal results of pso is a fitness function. in this research, one optimization objective is adjusted to a fitness function as: 15.0 yminj  (14) where 1y is normalized values of the 1y (equation (1)). a simulation was realized using matlab, and performed on a pc with an intel(r) pentium(r) dual cpu t2390 @ 1.86 ghz, and 0.99 gb ram. a simulation using pso was carried out based on the conditions in table 3. an optimal control solution was found. the computing time took 1.061202 s. convergence of the global best fitness value is shown in figure 6. the global best fitness value convergences at j = 0.3322. simulation with pso was repeated 4 times based on the number of gear from 1 to 4, and 4 simulated optimal control parameters were obtained. the battery optimal control parameters are listed in table 4 and the calculated battery optimal objectives based on prediction model is shown in table 5. vi. conclusion based on the experiment data, in order to control the large number of control parameters appropriately considering soc as the battery output objectives, the model construction which reproduce the characteristic value of soc from control parameter is needed. in this study, the stepwise method considering multicollinearity was applied to construct the 1 st order and 2 nd order polynomial model. the accuracy of prediction model made by stepwise method depends on how well the function of regression suits the data. there should be routine to check how well the function of regression is suitable with the given data. this can be done through routine updates to ensure that the value of error is always below the pre-specified error threshold. in this paper, a prediction model of battery soc has been reported using stepwise method table 3. the condition of pso simulation items value number of particles 30 number of iteration 200 table 4. the battery optimal control parameters control parameter meaning gear (-) 1 2 3 4 x1 load current (ampere) 601.41 572.04 577.10 580.19 x2 batteries voltage (volt) 73.38 59.66 69.16 73.34 x3 electric motor speed (rpm) 4,353.59 6,628.49 6,247.05 1,740.03 x4 electronic temperature ( o c) 67.86 67.71 67.98 67.48 x5 vehicle velocity (km/h) 71.72 71.37 69.75 70.77 x6 time (sec) 5.92 6.73 7.91 8.25 table 5. calculated battery optimal objectives optimization objective y1 meaning state of charge (%) gear (-) 1 0.704 2 0.703 3 0.696 4 0.690 figure 6. convergence of pso (j = 0.3322) b. wahono et al. / j. mechatron. electr. power veh. technol 06 (2015) 31–38 38 considering multicollinearity. this paper shows that the predictive accuracy by stepwise method considering multicollinearity was high. this was proved by the multiple correlation coefficient of 0.9000 or more and f value that is very high. it can be regarded that the stepwise method can effectively estimate the objectives. the optimal control input parameters obtained by pso were tested and analyzed. the result proved that the pso is an effective method for battery optimization problem. in order to improve the performance of battery and increase the security of electric vehicle, in the future work, these battery optimal control parameters should be validated on the road, and the results of validation based on the optimal control parameters simulation should be compared with the calculated battery optimal objective values. then, the battery model which added pso should be mounted in a controller, and control performance should be evaluated. acknowledgement the author would like to thank to aam muharam, sunarto kaleg, amin, naili huda, mulia pratama for the assistance in collecting experiment data, their suggestion, and productive discussion. references [1] h, wang, et al., “estimation of state of charge of batteries for electric vehicles,” international journal of control and automation, vol. 6, no. 2, pp. 185-194, april 2013. [2] w.y. chang, “the state of charge estimating methods for battery: a review,” isrn applied mathematics, vol. 2013, article id 953792, 7 pages, 2013. http://dx.doi.org/10.1155/2013/953792. [3] j. chiasson and b. vairamohan, “estimating the state of charge of a battery,” ieee transactions on control systems technology, vol. 13, no.3, pp. 465–470, 2005.http://dx.doi.org/10.1109/tcst.2004.8 39571. [4] h. anbuky and p. e. pascoe, “vrla battery state-of-charge estimation in telecommunication power systems,” ieee transactions on industrial electronics, vol. 47, no. 3, pp. 565–573, 2000. http://dx.doi.org/10.1109/41.847897. [5] b. xiao, et al.,“a universal state-of-charge algorithm for batteries,” design automation conference (dac), 47 th acm/ieee, pp. 687-692, 2010. http://dx.doi.org/10.1145/1837274.1837449. [6] n. zhou, et al., “a modified stepwise linear regression method for estimating modal sensitivity,” ieee power and energy society general meeting, pp. 1-7, 24-29 july2011.http://dx.doi.org/10.1109/pes.201 1.6039795. [7] a.c. rencher, “methods of multivariate analysis,” new york: wiley, 2002. [8] j.o. rawlings, et al., “applied regression analysis: a research tool,” 2 nd ed., new york: springer, 1998. [9] j. kennedy and r. eberhart, “particle swarm optimization,” proceedings of the ieee international conference on neural networks, vol. 4, pp. 1942–1948, 1995. http://dx.doi.org/10.1109/icnn.1995.48896 8. [10] r. eberhart, and y. shi, “particle swarm optimization: developments, applications and resources,” proceedings congress on evolutionary computation, vol. 1, pp. 8186, 2001. http://dx.doi.org/10.1109/cec.2001.934374. [11] m. ogawa et al., “development of method for construction of a response surface model and control parameter optimization method for automobile engine,” transactions of the society of instrument and control engineers, vol. 47 no. 10, pp. 501-510, 2011. http://dx.doi.org/10.9746/sicetr.47.501. [12] j.j. xu and z.h. xin, “an extended particle swarm optimizer,” proceeding of the 19 th ieee international parallel and distributed processing symposium, 2005. http://dx.doi.org/10.1109/ipdps.2005.101. [13] s. he, et al., “a particle swarm optimizer with passive congregation,” biosystems, vol. 78, pp. 135-147, 2004. http://dx.doi.org/10.1016/j.biosystems.2004. 08.003. [14] j. kennedy and r. eberhart. “swarm intelligence,” morgan kaufmann publishers inc., san francisco, ca, 2001. [15] k. ismail et al., “desain test vehicle untuk sistem manajemen energi kendaraan hibrida seri,” prosiding seminar nasional smart, pp. d84-d89, 2010. microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 53 modificatio of surface rough ess a d area of fecral substrate for catalytic co verter usi g ultraso ic treatme t y. putrasari 1 , p. untoro 2 , s. hasan 1 , . huda 3 , d. sebayang 1 1 advanced manufacturing and materials centre (ammc), faculty of mechanical and manufacturing engineering, university tun hussein onn malaysia (uthm) parit raja, batu pahat 86400, malaysia y.putrasari@gmail.com; sulaiman@uthm.edu.my; darwin@uthm.edu.my 2 centre for technology of nuclear industry materials national nuclear energy agency (batan) kawasan puspiptek gd. 71, serpong tangerang 15314, indonesia untoro@batan.go.id 3 research centre for electrical power and mechatronics indonesian institute of sciences (lipi) komp. lipi bandung , jl sangkuriang, gd 20, lt 2, bandung jawa barat 40135, indonesia. naili.huda@lipi.go.id diterima: 26 juni 2010; direvisi: 16 september 2010; disetujui: 13 desember 2010; terbit online: 24 desember 2010. abstrak kekasaran dan luas permukaan memainkan peranan penting terutama dalam deposisi dan reaksi katalis pada substrat catalytic converter. tujuan makalah ini adalah untuk menunjukkan modifikasi kekasaran dan luas permukaan substrat fecral untuk catalytic converter menggunakan metode ultrasonik. metode dilakukan dengan memproses fecral dalam piranti ultrasonic cleaning bath 35 khz dalam waktu 10 menit. kekasaran permukaan, morfologi, dan komponen kimia dari substrat catalytic converter fecral setelah proses ultrasonik dianalisis menggunakan atomic force microscope (afm) dan diamati dengan scanning electron microscope (sem) dikombinasikan dengan energy dispersive x-ray spectroscopy (eds). perlakuan ultrasonik dibantu dengan serbuk al2o3 berhasil meningkatkan kekasaran dan luas permukaan fecral lebih baik daripada serbuk sic. kata kunci: permukaan, perlakuan, kekasaran, fecral, substrat, catalytic, converter, ultrasonic. abstract surface roughness and area play important role especially in deposition and reaction of the catalyst in the catalytic converter substrate. the aim of this paper is to show the modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic method. the method was conducted by agitating the fecral in 10 minutes 35 khz ultrasonic cleaning bath. the surface roughness, morphology, and chemical components of fecral catalytic converter substrate after ultrasonic treatment were analyzed using atomic force microscope (afm) and examined with scanning electron microscope (sem) in combination with energy dispersive x-ray spectroscopy (eds). the ultrasonic treatment assisted with al2o3 powders successfully increased the roughness and surface area of fecral better than sic powders. keywords: surface, treatment, roughness, fecral, substrate, catalytic, converter, ultrasonic. i. i troductio fecral has been used for fabrication of high temperatures applications components: heating elements, fire grid and honeycomb (substrate) catalytic converters for automotive exhausts. the surface area of substrate plays important role in deposition and reaction of the catalyst [1,2,3]. the honey-comb manufactured is of the efforts to increase the amount of surface area available to support the catalyst, and therefore is often called a "catalyst support" [3,4]. other is to create washcoat, when developed on the substrate, forms a rough, irregular surface, which has a far greater surface area compared to the flat one, which then gives the converter substrate a larger surface area, and therefore more possible places for active precious metal sites [3,4,5,6]. mellali [7] studied the influence of substrate roughness and temperature on the adhesion/cohesion of alumina coatings, when starting with a cold substrate (<100°c) the adhesion/cohesion increases almost linear with the substrate roughness. henke [8] has used surface roughness measurements to estimate surface area on modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic treatment (y.putrasari, p. untoro, s. hasan, �. huda, d. sebayang) pp. 53-60 54 substrates. surfaces can be roughened or smoothened using various techniques including chemical deposition, grinding, polishing, and chemical etching [9]. the innovative approach for surface modification is ultrasonic treatment. panin [10] studied the effect of ultrasonic treatment on mechanical behavior of titanium and steel specimens. the ultrasonic treatment used by panin was done by exciting ultrasonic oscillations within a treating tool. the oscillation amplitude and frequency of waveguide that used were 15 µm and 24 khz. zhang [11] used ultrasonic horn type with the frequency and power of the ultrasound were set constant at 25 khz and 100 w respectively, for surface treatment of magnesium hydroxide to improve its dispersion in organic phase. the transducer of ultrasound with frequency of 20 khz was applied by liu [12] to the aramid/epoxy composites when it was just pulled off from the resin bath to enhance its adhesion. paniwnyk [13] has already shown that electronics materials can be surface modified using ultrasound in water medium. paniwnyk, suggested that a rough, debris free surface, is important for optimal adhesion and that ultrasound does achieve surface modification at low temperatures of 40°c in chemical free, green and environmentally friendly deionised water. in our previous effort [14,15,16], the influence of ultrasonic assisted with sic or al2o3 powders on fecral substrate to high temperature resistance and nio catalyst development has been discussed. the ultrasonic technique successfully increased the high temperature resistance of fecral substrate and homogeneity of nickel electroplating layer. however, the roughness and surface area of fecral after ultrasonic treatment still needed special investigation. therefore, in this study, the investigations of modification of surface roughness and area of fecral substrate for catalytic converter by ultrasonic treatment were conducted. the discussions in this paper are focused on three following issues. roughness, as a measure of surface topography commonly occurs in the form of scratches, digs, pits, dust particles, polishing marks on optical surfaces, machining marks on machined surfaces, granularity or crystallites in films deposited on surfaces, undulations left by chemical etching or electropolishing, or marks left by rollers on sheet stock [8]. in this research, ultrasonic approach assisted with sic and/or al2o3 powders was expected to tune the surface roughness of fecral substrate. the surface roughness was created to obtain the good quality for the next catalyst coating process on the fecral substrate as explained in our previous papers [14-16]. surface roughness was related to coating adhesion/cohesion of materials [7]. ultrasonic wave or sound will generate cavitation bubbles in a liquid system [18]. then, the explosion of the cavitation bubbles will produce a jet flash energy that can damage the surface of a solid material. in this work, slurring of sic or al2o3 powders in ultrasonic media liquid was expected to assist the process of surface destruction. it is estimated that the particles of the powders driven by the jet flash energy would hit the surface of the material (fecral). therefore, the irregular surface roughness occurs. due to the higher hardness property of sic, it was expected that ultrasonic treatment with sic would produce higher roughness to fecral. atomic force microscopy (afm), is one member of a family of techniques that provides images of surface topography by mechanically moving a probe across the sample to detect the contours of the surface and enables one to detect surface morphology, nanoscale structures and molecular and atomic scale lattices [8]. refer to literature [8], the afm was chosen for the analysis of surface roughness and estimation of surface area of fused silica and glass substrates. this work used similar approach to calculate the surface area of fecral substrate. the approach assumed that all morphology grains were nodules on fecral substrate in half of sphere form. then, the mean area taken from afm was assumed as area of circles with diameter same as the sphere. the half of sphere surface area was then calculated using sphere surface area formula. ii. experime t a. materials the fecral foils (aluchrom yhf) with 0.1 mm thickness were used as substrate in this experiment. the chemicals components of this foil are presented in table 1. table 1. chemical components of aluchrom yhf (wt-%) [17]. i cr fe c mn si al zr y hf min 19.0 bal 5.5 max 0.3 22.0 0.05 0.50 0.50 6.5 0.07 0.10 0.10 0.01 journal of mechatronics, electrical power vol. 01, �o 2, 2010 the substrate was prepared by cut foils into 1 cm x 2 cm. the water and methanol were applied as medium for ultrasonic treatment. the sic and al2o3 powders with particle size 90 µm were provided to assist the ultrasonic treatment. these materials were supplied by syarikat sainfik bersatu, sdn. bhd. b. ultrasonic treatment the ultrasonic cleaning bath laborette 17 was applied to the fecral foils treatment. the voltage 230 v/i~, input power 2 x 240 w/period, frequency 50-60 hz and the ultrasound frequency 35 khz are the technical data. the bath was filled with water due to ultrasonic irradiation media. the specimens were put into a beaker which consists of methanol mixed with sic and/or al2o3 powders as liquid solution. the mg/ml concentration of solution by slurring 20 mg sic or al2o3 powders into 100 ml methanol. the beaker filled with slurry and fecral foils then immersed into the ultrasonic bath. the fecral then sonicated for 10 minutes. the illustration of ultrasonic treatment was presented in figure 1. the specimens then dried in atmospheric condition. figure 1. schematic diagram of ultrasonic treatment (1) methanol; (2) specimen; (3) beaker; (4) water; (5) bath; (6) ultrasonic source c. surface characterization atomic force microscope (afm) images of the fecral, fecral under ultrasonic treatment with sic, and al2o3 were collected using a xe 100 park systems atomic force microscope (park systems corp). the effect of ultrasonic on the fecral substrate was examined from imaging a region on the sample before and after the ultrasonic treatment. the roughness measurement was taken using horizontal straight line mode. the roughness profiles were presented to clarify the roughness phenomenon caused by ultrasonic treatment on fecral surface. the mean roughness (ra) was resulted from a random 100 µm2 scan area of specimens. the ra of each specimen was presented as the reported 3 2 1 of mechatronics, electrical power, and vehicular technology the substrate was prepared by cutting fecral foils into 1 cm x 2 cm. the water and methanol were applied as medium for ultrasonic treatment. powders with particle size ≤ provided to assist the ultrasonic treatment. these materials were supplied by syarikat sainfik bersatu, sdn. bhd. the ultrasonic cleaning bath laborette 17 was applied to the fecral foils treatment. the voltage 230 v/i~, input power 2 x 240 w/period, 60 hz and the ultrasound frequency 35 khz are the technical data. the bath was fully to ultrasonic irradiation media. the specimens were put into a beaker which consists of methanol mixed with sic powders as liquid solution. the 0.2 concentration of solution could be made powders into 100 ml methanol. the beaker filled with slurry and fecral foils then immersed into the ultrasonic bath. the fecral then sonicated for 10 minutes. the illustration of ultrasonic treatment was the specimens then dried ultrasonic treatment; (1) methanol; (2) specimen; (3) beaker; (4) water; (5) bath; (6) ultrasonic source. atomic force microscope (afm) images of ultrasonic treatment were collected using a xe100 park systems atomic force microscope (park systems corp). the effect of ultrasonic on the fecral substrate was examined using the result imaging a region on the sample before and after the ultrasonic treatment. the roughness measurement was taken using horizontal straight line mode. the roughness profiles were presented clarify the roughness phenomenon caused by rasonic treatment on fecral surface. the mean roughness (ra) was resulted from a random 100 µm2 scan area of specimens. the ra of each as the reported roughness. the 3d images from afm were displayed to analyze the topography of each specimen. the grain area (µm measured in afm analysis to calculate the total surface area of specimen. the scanned surface areas of specimen were calculated by sphere surface area approach. the microstructure and chemical components on s before and after ultrasonic treatment were investigated using jeol scanning electron microscopy (sem) model jsm combination with energy dispersive x spectroscopy (eds). iii. result a d d a. influence of ultrasonic treatmen surface roughness of fecral substrate figure 2 shows the atomic force microscope (afm) roughness profile of the fecral (a) untreated, (b) ultrasonic treatment with sic, and (c) ultrasonic treatment with were taken by afm random sca µm long area of fecral. from these profiles, can be seen that the highest, medium, and lowest gap between peaks and valley occurred on fecral untreated, treatment with sic, respectively. the means roughness of these fecral presented in table (a) (b) (c) figure 2. roughness profile of fecral b) ultrasonic treatment with sic, c) ultrasonic treatment with al the mean roughness of each specimen was resulted from roughness analysis using horizontal 4 5 6 iss� 2087-3379 55 roughness. the 3d images from afm were displayed to analyze the topography of each specimen. the grain area (µm 2 ) as 2d image was measured in afm analysis to calculate the total surface area of specimen. the scanned surface areas of specimen were calculated by sphere surface area approach. the microstructure and chemical components on surface of fecral before and after ultrasonic treatment were investigated using jeol scanning electron microscopy (sem) model jsm-6380la in combination with energy dispersive x-ray discussio influence of ultrasonic treatment on surface roughness of fecral substrate figure 2 shows the atomic force microscope (afm) roughness profile of the fecral (a) untreated, (b) ultrasonic treatment with sic, and (c) ultrasonic treatment with al2o3. the profiles were taken by afm random scanning from 10 µm long area of fecral. from these profiles, it the highest, medium, and lowest gap between peaks and valley occurred on fecral untreated, treatment with al2o3 and with the means roughness of these table 2. (a) (b) (c) roughness profile of fecral a) untreated, b) ultrasonic treatment with sic, c) ultrasonic treatment with al2o3. the mean roughness of each specimen was resulted from roughness analysis using horizontal modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic treatment (y.putrasari, p. untoro, s. hasan, �. huda, d. sebayang) pp. 53-60 56 straight line method on random position of 10 µm x 10 µm afm image. the most completed results were observed using the afm 3d image. the 3d image for representing the visualization of different topography from each specimen was displayed on figure 3. (a) (b) (c) figure 3. 3d observation on fecral a) untreated, b) ultrasonic treatment with sic, c) ultrasonic treatment with al2o3. table 2. mean roughness of fecral. materials mean roughness, ra (nm) fecral untreated 31.409 fecral ultrasonic treatment with sic 15.790 fecral ultrasonic treatment with al2o3 34.470 in contrast with the expected result, according to afm roughness test results; profile, mean roughness, and 3d topography images, the fecral treatment with al2o3 has the highest surface roughness compared the two others. it can be estimated that the roughness of fecral resulted from treatment using ultrasonic approach, assisted with sic and/or al2o3 powders depend on the particle size and homogeneity of the powders. b. the influence of ultrasonic treatment on fecral surface area figure 4 shows the grain area of fecral which were (a) untreated, (b) ultrasonic treatment with sic, (c) ultrasonic treatment al2o3 were taken using afm, respectively. these images resulted from 10 µm x 10 µm random scanning area of each specimen. the grain numbers on fecral ultrasonic treatment with sic was the highest, followed by fecral untreated, and the lowest was fecral ultrasonic treatment with al2o3. whereas the higher grain area was fecral ultrasonic treatment with al2o3, then fecral untreated, and the smallest was fecral ultrasonic treatment with sic. the mean grain area and grain numbers from afm examination of fecral is presented in table 3. table 3. mean of grain area of fecral. materials grain numbers mean area, (µm 2 ) fecral untreated 172 5.412 x 10 -1 fecral ultrasonic treatment with sic 183 5.058 x 10 -1 fecral ultrasonic treatment with al2o3 167 5.599 x 10 -1 table 4. surface area of fecral. materials grain numbers mean of half nodules surface area, (µm 2 ) total surface area, (µm 2 fecral untreated 172 10.82 x 10 -1 1861.73 x 10 -1 fecral ultrasonic treatment with sic 183 10.12 x 10 -1 1851.96 x 10 -1 fecral ultrasonic treatment with al2o3 167 11.20 x 10 -1 1870.40 x 10 -1 journal of mechatronics, electrical power vol. 01, �o 2, 2010 (a) (b) (c) figure 4. grain area of fecral ultrasonic treatment with sic; c) ultrasonic treatment with al2o3. the total surface area of 10 scanning fecral area obtained from a half area multiplied by grain numbers, which presented in table 4. from the table, it can be seen that the of mechatronics, electrical power, and vehicular technology a) untreated, b) ultrasonic treatment with sic; c) ultrasonic the total surface area of 10 µm x 10 µm scanning fecral area obtained from a half area multiplied by grain numbers, which presented in can be seen that the fecral treatment with al total surface area. the surface area acts as catalyst reaction effective. in order to accommodate the catalyst in significant amounts, substrate must be provided wi area. twigg [19] suggest substrate must provide a maximum superficial surface area that can be presented to the exhaust gas, as it is upon this surface that the catalytic coating is applied, and on which the pollutant reactant gases must impinge in order to react. the afm technique results ( show that the fecral ultrasonic treatment with al2o3 was rougher than with sic and the surface area followed linearly. it estimated that the roughness of fecral resulted from treatment using ultrasonic approach, assisted with sic and/or al2o3 powders also depend on the particle size and homogeneity of the powders. c. the influence of ultrasonic treatment on surface morphology of fecral and its chemical composition figure 5 reveals sem images and eds results of fecral substrates which were (b) ultrasonic treatment with sic, and (c) ultrasonic treatment with respectively. the morphology of the f untreated substrate forms a line texture along the roller manufacturing process direction. on the other hand, the morphology of the fecral substrate treatment with showed many nodules, and a number of dimples were formed. the differe surface obviously describe the different roughness, and have been clarified using afm in the discussion before. the sic grains also observable on the fecral ultrasonic treatment with sic powders (figure 5.b) and al2o3 grain on the fecral ultrasonic treatment with al2o3 powders (figure 5.c). to clarify the chemical components adhered on each fecral the eds technique was implemented. the arrow-sign at figure 5.a shows standard fecral foils chemicals component. while on fecral ultrasonic treatment with sic powders (figure 5b), the arrow sic grains. meanwhile, on fecral ultrasonic treatment with al2o3 powders (figure 5.c), the point with arrow-sign indicates the it can be an evidence to the i ultrasonic treatment on chemical composition of fecral surface, although the percentage of each chemicals is not displayed. the al2o3 and sic powders after ultrasonic treatment process iss� 2087-3379 57 fecral treatment with al2o3 resulted the highest the surface area acts as the main role on the catalyst reaction effective. in order to accommodate the catalyst in significant amounts, substrate must be provided with a high surface area. twigg [19] suggested that the design of substrate must provide a maximum superficial surface area that can be presented to the exhaust gas, as it is upon this surface that the catalytic coating is applied, and on which the pollutant and reactant gases must impinge in order to react. e results (table 2 and 4) that the fecral ultrasonic treatment with was rougher than with sic and the surface y. it estimated that the roughness of fecral resulted from treatment using ultrasonic approach, assisted with sic powders also depend on the particle size and homogeneity of the powders. the influence of ultrasonic treatment on logy of fecral and its chemical composition figure 5 reveals sem images and eds results which were (a) untreated, (b) ultrasonic treatment with sic, and (c) with al2o3 powders, respectively. the morphology of the fecral substrate forms a line texture along the roller manufacturing process direction. on the other hand, the morphology of the fecral substrate treatment with al2o3 and/or sic many nodules, and a number of dimples were formed. the different textures of fecral cribe the different surface roughness, and have been clarified using afm in the sic grains also observable on the fecral ultrasonic treatment with sic powders (figure grain on the fecral ultrasonic powders (figure 5.c). to clarify the chemical components adhered on each fecral the eds technique was implemented. sign at figure 5.a shows the standard fecral foils chemicals component. n fecral ultrasonic treatment with sic powders (figure 5b), the arrow-sign indicates sic grains. meanwhile, on fecral ultrasonic powders (figure 5.c), the sign indicates the al2o3 grains. evidence to the influenced of ultrasonic treatment on chemical composition of fecral surface, although the percentage of each chemicals is not displayed. and sic powders stick on fecral after ultrasonic treatment process was a proof that modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic treatment (y.putrasari, p. untoro, s. hasan, �. huda, d. sebayang) pp. 53-60 58 the jet flush energy of ultrasonic irradiation promoted the powders to bond on the substrate. it is estimated the amount of the adhered powders will increase with the increase of the ultrasonic treatment duration. then if the specimen is oxidized, the al2o3 and sio will be formed on fecral substrate. it was known that al2o3 and sio are include in the type of higher surface area catalyst carrier [3]. (a) (b) (c) figure 5. morphology and eds of fecral a) untreated, b) ultrasonic treatment with sic; c) ultrasonic treatment with al2o3. journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 59 iv. co clusio the surface treatment using ultrasonic assisted with al2o3 powders for 10 minutes increased the surface roughness of fecral substrate better than sic powders. the greater surface area of fecral substrate was achieved using 10 minutes ultrasonic treatment assisted with al2o3 powders, compared to one assisted with sic powders. the al2o3 and sic powders were successfully attached on fecral substrate after ultrasonic treatment process. these achievements will be useful for catalytic converter production using fecral as a substrate. ack owledgeme t the authors would like to thank the ministry of higher education malaysia and universiti tun hussein onn malaysia (uthm) through the funding support of fundamental research grant scheme (frgs), vot no. 0265 and 0361. the authors would also like to thank the thyssen krupp vdm gmbh for supplying material. refere ces [1]. bruck, r., emitec gmbh., lohmar. "development status of metal substrate catalysts" in material aspects in automotive catalytic converters, bode, h., wiley-vch verlag gmbh &co. kgaa, 2002, pp. 18-30. [2]. nicholls, j. r., and quadakkers, w. j. "materials issues relevant to the development of future metal foil automotive catalytic converters" in material aspects in automotive catalytic converters, hans bode, wiley-vch verlag gmbh &co. kgaa, 2002, pp 3148. [3]. heck. r. m. et al, catalytic air pollution control commercial technology 3 rd ed, john wiley & sons, inc., 2009. [4]. bharali. p., "automotive exhaust catalysis", �. e. quest, 3, issue 4, pp 4043, 2010. [5]. sun, h., et al, "preparation of well-adhered γ-al2o3 washcoat on metallic wire mesh monoliths by electrophoretic deposition", applied surface science, 253, pp. 33033310, 2007. [6]. whu, x., et al., "influence of an aluminized intermediate layer on the adhesion of a γ-al2o3 washcoat on fecral", surface and coatings technology, 190, pp. 434-439, 2005. [7]. mellali, m., et al., "influence of substrate roughness and temperature on the adhesion/cohesion of alumina coatings", surface and coatings technology, 81, pp. 275-286, 1996. [8]. henke, l., et al., "an afm determination of the effects on surface roughness caused by cleaning of fused silica and glass substrates in the process", biosensors and bioelectronics, 17, pp. 547-555, 2002. [9]. ortel, e., et al., "influence of steel substrate roughness on morphology and mesostructure of tio2 porous layers produced by template-assisted dip coating", microporous and mesoporous materials, 127, pp. 17–24, 2010. [10]. panin, a.v., et al., "the effect of ultrasonic treatment on mechanical behavior of titanium and steel specimens", theoretical and applied fracture mechanics, 41, pp. 163–172, 2004. [11]. zhang, f., et al., "surface treatment of magnesium hydroxide to improve its dispersion in organic phase by the ultrasonic technique", applied surface science, 253, pp. 7393–7397, 2007. [12]. liu, l., et al., "ultrasonic treatment of aramid fiber surface and its effect on the interface of aramid/epoxy composites", applied surface science, 254, pp. 2594– 2599, 2008. [13]. paniwnyk, l., cobley, a., "ultrasonic surface modification of electronics material", physics procedia, 3, pp. 1103– 1108, 2010. [14]. sebayang, d., et al., "influence of difference deposition technique of nickel on the fecral metallic monolith" in proceedings of the malaysian metallurgical conference '09 (mmc'09), unimap perlis malysia, 2009. [15]. sebayang, d., et al., "effect of pretreatment using ultrasonic technique with sic or al2o3 on high temperature oxidation behavior of the fecral” in proceeding of the 14 th international conference on applied mechanics and mechanical engineering amme-14, egypt, 25-27 may, military technical college cairo, 2010. [16]. sebayang, d. et al., "nio development on fecral substrate for catalytic converter ultrasonic and nickel electroplating methods", to be published in the 2010 international conference on material and manufacturing technology (icmmt 2010), chongqing china, 17-19 september modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic treatment (y.putrasari, p. untoro, s. hasan, �. huda, d. sebayang) pp. 53-60 60 2010, advanced materials research journal. [17]. _______ "aluchrom yhf material data sheet", (2008), no. 4049 march 2008". germany: thyssenkrupp vdm. [18]. saez, v. and mason, t.j., "sonoelectrochemical synthesis of nanoparticle", molecules, pp. 1420-3049, 2009. [19]. twigg, m.v. and webster, d.e. "metal and coated metal catalysts" in structured catalysts and reactors 2 nd ed, cybulski, a., moulijn, j.a. taylor & francis group, usa, 2006 microsoft word 242-1542-3-pb gt j. mechatron. electr. power veh. technol. 06 (2015) 75-82 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379   www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.75-82 algorithm of 32-bit data transmission among microcontrollers through an 8-bit port midriem mirdanies *, hendri maja saputra, estiko rijanto research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komp lipi bandung, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia received 24 july 2015; received in revised form 13 october 2015; accepted 21 october 2015 published online 30 december 2015 abstract this paper proposes an algorithm for 32-bit data transmission among microcontrollers through one 8-bit port. this method was motivated by a need to overcome limitations of microcontroller i/o as well as to fulfill the requirement of data transmission which is more than 10 bits. in this paper, the use of an 8-bit port has been optimized for 32-bit data transmission using unsigned long integer, long integer, and float types. thirty-two bit data is extracted into binary number, then sent through a series of 8-bit ports by transmitter microcontroller. at receiver microcontroller, the binary data received through 8-bit port is reconverted into 32 bits with the same data type. the algorithm has been implemented and tested using c language in atmega32a microcontroller. experiments have been done using two microcontrollers as well as four microcontrollers in the parallel, tree, and series connections. based on the experiments, it is known that the data transmitted can be accurately received without data loss. maximum transmission times among two microcontrollers for unsigned long integer, long integer, and float are 630 µs, 1,880 µs, and 7,830 µs, respectively. maximum transmission times using four microcontrollers in parallel connection are the same as those using two microcontrollers, while in series connection are 1,930 µs for unsigned long integer, 5,640 µs for long integer, and 23,540 µs for float. the maximum transmission times of tree connection is close to those of the parallel connection. these results prove that the algorithm works well. keywords: transmission algorithm; 32-bit data; data transmission; 8-bit port; microcontroller; c language. i. introduction in a complex system, the use of multiple microcontrollers is typically required to handle each sub section. therefore, a communication among microcontrollers is needed [1, 2]. the number of the microcontrollers that can be connected and the number of data that can be sent are very determines in the communication media selection. the communications media on the microcontroller is limited and data size that can be sent is usually 8-10 bits. research that applied communication between microcontrollers via uart using zigbee wireless have been carried out by reddy [3] and thakur [4]. a similar thing has been done by saputra [1] using a ys-c20k type of wireless module. in leeman research [5], communication between microcontrollers via uart was performed using rs-232 cable, while solanke [6] using a wireless rf at frequency 433.92 mhz. data communication via uart / ys-c20k will be troublesome if the communication is done among many microcontrollers simultaneously. research that applied communication via the can bus have been done by prickett [7] and kutlu [8], however, communication using this medium requires an additional interface. moreover, it is difficult to be implemented on an 8-bit microcontroller with the minimum system which does not provide an embedded can controller i.e. atmega8/ atmega8535. communication among the microcontrollers also can be made using an 8-bit port. research that applied communication among the microcontrollers through an 8 port have been done by saputra [1] and mirdanies [2], however the number of data are limited to 8 bits only (0255 decimal). communication among the microcontrollers through multiple 8-bit ports can also be done by adding port expander [9], but this * corresponding author.tel: +62-22-2503055 e-mail: midriem.mirdanies@lipi.go.id http://dx.doi.org/10.14203/j.mev.2015.v6.75-82 m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 76 method is not optimal due to the addition of several devices and coding is not practical. this paper proposes a new algorithm for 32bit data transmission among microcontrollers through one port which is consisted of 8 bits. the data types used are long integer, unsigned long integer, or float types [10]. this method is used to overcome the limitations of the microcontroller i/o for connectivity among microcontrollers without the use of additional interfaces, and requirement of data transmission more than 10 bits. communication can be done among many microcontrollers simultaneously using parallel, tree, or series connection. experiments have been done using four atmega32a microcontroller boards [11]. ii. method/material an example connection between two microcontroller can be seen in figure 1. several pins used on the port partialy functioned as identifier while others as data. pins configuration for unsigned long integer, long integer, and float types can be seen in figure 2, figure 3, and figure 4. pins used as data in both unsigned long integer and long integer data types are pin 0-4, while in float data type are pin 0-3. in the second block of data transmission, pin 0 in long integer and float serves as an identifier that the data sent is positive (0) or negative (1). pin 4 on float serves as the identifier that the data sent is an integer (0) or fractions (1). pin 5 in any data type serves as the identifier from the transmitter indicating that the data is ready to be read by the receiver. pin 6 as an identifier from the transmitter indicating that the data sent is the last data, and pin 7 serves as the identifier from the receiver which indicates that the data has been read/received. connection among microcontrollers described in this paper is not limited for two microcontroller, but can be used for communication with many microcontrollers at the same time in parallel, tree, or series connections. an example of each connection type used can be seen in figures 5, 6, and 7. specifically in tree connection, an additional confirmation step is required for sending data to a specific microcontroller. this step to ensure that the data transmitted to the microcontroller target is correct. therefore, the number of microcontrollers that can be installed is limited to 2 64 units. pin configuration used in this step can be seen in figure 8. pins 0-5 are used to store data, while the pin 6 is the identifier from the transmitter that the data is ready to be read and pin 7 is the identifier from the receiver that the data has been read. a. algorithm of 32-bit data transmission data transmission flowchart among microcontrollers for unsigned long int, long int, and float types can be seen in figure 9, figure 10, and figure 11. figure 1. connection between two microcontrollers figure 2. pins asignment for unsigned long integer type ·0 ·1 ·2 ·3 ·4 ·5 ·6 ·7 data identifier data per block last data data has been received figure 3. pins assignment for long integer type figure 4. pins assignment for float type ·0 ·1 ·2 ·3 ·4 ·5 ·6 ·7 data identifier negative/positive (on the second block transmission) data per block last data data has been received ·0 ·1 ·2 ·3 ·4 ·5 ·6 ·7 data identifier data per block last data data has been received negative/positive (on the second block transmission) integer or fraction m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 77 at the transmitter microcontroller, the 32-bit data is extracted into binary number using equation 1 and equation 2, then it is sent through a series of 8 bits. _ % 2 (1) _ _ 2⁄ (2) where is a binary value that will be stored on data pins. the equations is repeated until _ 0. at the receiver microcontroller, the binary data received through 8-bit port is reconverted into 32 bits with the same data type. this algorithm has an acknowledgment or an identifier that ensures the data has been received so errors can be avoided. the waiting process for this acknowledgement is 100 ms, if no acknowledgement arrived, then process will be stop and system will return to 0 value (that means an error/mistake occured). there are differences in the phases of data transfer in each type as shown in figure 9, figure 10 and figure 11. unsigned long int consists of two phases: transmission of the identifier of data type and data/value. long int consists of three phases: transmission of the identifier of data type, identifier of positive or negative sign, and data/value. whereas float consists of five phases: transmission of the identifier of data type, identifier of positive or negative sign, decimal value, number of zero value behind the comma, and fractional value. figure 5. series connection figure 6. parallel connection figure 7. tree connection figure 8. confirmation step for sending data to a specific microcontroller in tree connection type ·0 ·1 ·2 ·3 ·4 ·5 ·6 ·7 data identifier data is ready to read data has been received figure 9. flowchart of unsigned long int data transmission initialization set identifier: data to be transmitted is unsigned long int (pin 1 = 1) and set identifier: data is ready to read (pin 5 = 0) transmitter receiver initialization read identifier, call procedure to read unsigned long int, and set identifier: data has been read (pin 7 = 0) set identifier: data isn't ready to read (pin 5 = 1) set identifier: data hasn't been read (pin 7 = 1) set pins 0-4 = 0, set identifier: data is ready to read, and set identifier: now is last block (pin 6 = 0) read data and set identifier: data has been read set identifier: data isn't ready to read and set identifier: now isn't last block (pin 6 = 1) set identifier: data hasn't been read convert input_value to binary: bincounter = input_value % 2 input_value = input_value / 2 enter each bit of bincounter to pins 0-4 and set identifier: data is ready to read read data (pin 0-4), and set identifier: data has been read set identifier: data isn't ready to read set identifier: data hasn't been read . . . enter bit in the last block of bincounter to pins 0-4, set identifier: data is ready to read, and set identifier: now is last block read data, merge, and change to decimal, then set identifier: data has been read set identifier: data isn't ready to read and set identifier: now isn't last block set identifier: data hasn't been read if input_value = 0 then else then . . . . . . m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 78 there are an additional steps in tree connection before sending data, i.e. unsigned long integer, long integer, or float types, that can be seen in figure 12. input_value mentioned in figure 12 is a number of specific microcontroller (0-63). afterwards, the next process is the same as in figure 9, figure 10, or figure 11. b. data transmitter/receiver procedures in order to implement the algorithm, a program has been created using c language with codevision advanced avr v3.10 ide. four functions have been created for data transmission, those are int datasend_unsigned_long_int(unsigned long int input_value) int datasend_long_int(long int input_value) int datasend_float(float input_value) int datasend_mikroke(int micro) figure 10. flowchart of long int data transmission set identifier: data to be transmitted is long int (pin 0 = 1) and identifier: data is ready to read (pin 5 = 0) read identifier, call procedure to read long int, and set identifier: data has been read (pin 7 = 0) set identifier: data isn't ready to read (pin 5 = 1) set identifier: data hasn't been read (pin 7 = 1) . . . enter each value of bincounter to pins 0-4, and set identifier: data is ready to read read data (pin 0-4), and set identifier: data has been read initialization transmitter receiver initialization set pins 0-4 = 0, set identifier: data is ready to read, and set identifier: now is last block (pin 6 = 0) read data and send identifier: data has been read set identifier: data hasn't been read set identifier: data isn't ready to read and set identifier: now isn't last block (pin 6 = 1) convert input_value to binary: bincounter = input_value % 2 input_value = input_value / 2 enter each bit of bincounter to pins 1-4, set pin 0 as identifier of positive value (0) or negative value (1), and set identifier: data is ready to read read identifier (pin 0) and save to var. multiplier, read data (pin 1-4), and set identifier: data has been read set identifier: data isn't ready to read set identifier: data hasn't been read set identifier: data isn't ready to read set identifier: data hasn't been read enter bit in the last block of bincounter to pins 0-4, set identifier: data is ready to read, and set identifier: now is last block read data, merge, and change to decimal, and set identifier: data has been read set identifier: data isn't ready to read and set identifier: now isn't last block set identifier: data hasn't been read if input_value = 0 then else then . . . . . . figure 11. flowchart of float type data transmission separated fractions and integer of var. input_value fractions=input_value-floor (input_value) input_value = floor (input_value) then convert var. input_value to binary. bincounter = input_value floor(input_value/2)*2 input_value = floor (input_value/2) enter each bit of bincounter to pins 1-3, set pin 0 as identifier of positive value (0) or negative value (1), set identifier: data is integer (pin 4=0), and set identifier: data is ready to read . . . . . . initialization transmitter receiver initialization send identifier: data to be transmitted is float (pin 2 = 1) and identifier: data is ready to read (pin 5 = 0) read identifier, call procedure to read float, and set identifier: data has been read (pin 7 = 0) set identifier: data is'nt ready to read (pin 5 = 1) set identifier: data hasn't been read (pin 7 = 1) set pins 0-4 = 0, set identifier: data is ready to read, and identifier: now is last block (pin 6 = 0) read data and set identifier: data has been read set identifier: data hasn't been read set identifier: data isn't ready to read and identifier: now isn't last block (pin 6 = 1) read identifier (pin 0) then save to var. multiplier, read data (pin 1-3) then save to var. data1, and set identifier: data has been read set identifier: data hasn't been read set identifier: data isn't ready to read enter each bit of bincounter to pins 0-3, set identifier: data is integer, and set identifier: data is ready to read read data (pin 0-3) then save to var. data1, and set identifier: data has been read set identifier: data hasn't been read set identifier: data isn't ready to read if all of var. input_value (integer) has been sent, then count the number of 0 after comma and insert to pin 0-3, then set identifier: data is ready to read read data (pin 0-3) then save to var. jml0, and set identifier: data has been read set identifier: data isn't ready to read set identifier: data hasn't been read convert var. fraction to integer value, then set input_value = fraction. convert var. input_value to binary. bincounter = input_value floor(input_value/2) *2 input_value = floor(input_value/2) enter each value of bincounter to pins 0-3, set identifier: data is fraction (pin 4=1), and set identifier: data is ready to read read data (pin 0-3) then save to var. data2, and set identifier: data has been read set identifier: data isn't ready to read set identifier: data hasn't been read enter bit in the last block of bincounter to pins 0-3, set identifier: data is fraction (pin 4=1), set identifier: data is ready to read, and set identifier: now is last block read data, merge, reconvert var. data2 to fraction (using var. jml0), and convert to decimal: data1 = (data1 + data2) x multiplier set identifier: data has been read set identifier: data isn't ready to read and set identifier: now isn't last block set identifier: data hasn't been read if input_value = 0 then else then . . . . . . . . . . . . m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 79 where input_value filled with values that will be sent. micro filled with numbers of specific microcontroller that will receive the data. all these functions will return to 1 if it is successful or otherwise will return to 0. the receiver microcontroller simply call one of the following two procedures. int datareceive() int specificdatareceive (int micro) if the connection type used is tree type, then call the procedure int specificdatareceive (int micro) on the receiver microcontroller. parameter micro is filled with the microcontroller number (0-63). if the connection used is not tree type, then call the procedure int datareceive () on the receiver microcontroller. this function will automatically call other functions according to the data type that the transmitter used, and return 1 if successful and otherwise is 0. functions that are called are as follows. long int datareceive_long_int() unsigned long int datareceive_unsigned_ long_int() float datareceive_float() the function returns a value that is received whose type is unsigned long int, long int, or float. iii. result and discussion experiments have been conducted to test the accuracy and speed of data transfer between two microcontrollers (figure 1) as well as using four microcontrollers in series (figure 5), parallel (figure 6), and tree (figure 7). the data transmitted and received is displayed on a pc terminal via com 3 and com 5 to view the results. port b is used for experiments between two microcontrollers. for experiments using 4 microcontrollers ports are assigned as follows. in series connection, the transmitter uses port a while the receiver uses port b. in parallel connection, the transmitter uses ports a, b, and c, while the receiver uses port b. in tree connection, both the transmitter and receiver use port b. measurement of data transmission time is performed using the timer microcontroller [11] as shown in figure 13. the time calculation algorithm can be seen in figure 14. at the start of the data transmission process, the transmitter set port d.6 = 0, then timer will start calculate using 16-bit timer, after the data transmission process is completed then set the port d.7 = 0, finally data transmission time can be calculated from the time interval. a. data accuracy experiments several data from minimum to maximum for each data type are used in experiments. figure 15 and figure 16 are described example data which sent from the first microcontroller and data received by the second microcontroller. it can be seen that the data transmitted from the first microcontroller can be received without any damage or data loss by the second microcontroller. the range of values that can be used for each data type are listed in table 1. figure 12. flowchart of confirmation step for sending data to a specific microcontroller in tree connection initialization transmitter receiver initialization read input_value and convert to binary: bincounter = input_value % 2 input_value = input_value / 2 enter each bit of bincounter to pins 0-4 and set identifier: data is ready to read (pin 6 = 0) read data (pin 0-4), merge, and change to integer, then send identifier: data has been read (pin 7 = 0) set identifier: data is'nt ready to read (pin 6 = 1) set identifier: data hasn't been read (pin 7 = 1) call data transmission procedures for unsigned long integer, long integer, or float figure 14. algorithm of data transmission time calculation figure 13. connection for calculation of transmission time m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 80 b. data transmission time experiments experiment of transmission times is done by sending sampling value from minimum to maximum. the number of data used in experiment is 11 for each type. in the float, the maximum number of digit used is seven digit [12, 13]. the transmission time between two microcontrollers for unsigned long int, long int, and float can be seen in tables 2, 3, and 4. based on table 2, table 3, and table 4 it can be seen that maximum data transmission times for 32 bits between two microcontrollers for unsigned long integer, long integer, and float are 630 µs, 1,880 µs, 7,830 µs. unsigned long integer has the fastest time of data transmission than long integer and float. this is related to the number of processes/steps used in float is more than long integer, and number of processes used in long integer is more than unsigned long integer. the experiments results of data transmission time using four microcontrollers in series, parallel, and tree connections using unsigned long int, long int, and float can be seen in figures 17, 18, and 19. x-axis in figure 19 is float value which is represented as data sequence as can be seen in table 4. based on figures 17, 18, and 19, it can be seen that data transmission time of unsigned long integer, long integer, and float are almost figure 15. data transmitted from the first microcontroller figure 16. data received by the second microcontroller table 1. data types with the range of values data types value unsigned long int 0 to 4,294,967,295 long int -2,147,483,647to2,147,483,647 float ±1.175e-38 to ±3.402e38 (seven digit precision) [12,13] table 2. data transmission time of unsigned long int no unsigned long int time (µs) 1 0 50 2 390,451,572 550 3 780,903,145 570 4 1,171,354,717 620 5 1,561,806,289 620 6 1,952,257,861 610 7 2,342,709,434 620 8 2,733,161,006 630 9 3,123,612,578 630 10 3,514,064,150 630 11 4,294,967,295 630 table 3. data transmission time of long int no long int time (µs) 1 -2,147,483,647 1820 2 -1,717,986,919 1880 3 -1,288,490,189 1880 4 -858,993,460 1820 5 -429,496,730 1740 6 0 50 7 429,496,729 1730 8 858,993,459 1820 9 1,288,490,188 1870 10 1,717,986,918 1860 11 2,147,483,647 1810 table 4. data transmission time of float no float time (µs) 1 -999,999.9 7290 2 -12,345.67 7830 3 -123.456 6220 4 -12.3 2920 5 -0.1 1750 6 0 460 7 0.1 1720 8 12.3 2890 9 123.456 6180 10 12,345.67 7810 11 999,999.9 7260 m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 81 equal between tree and parallel connections with the average absolute difference on unsigned long integer is 69 μs, long integer is 66 μs, and float is 54 μs, while series connection is slower with an average difference on unsigned long integer is 1,160 μs to parallel, long integer is 3,334 μs to parallel, and float is 9,543 μs to parallel. it is due to the data transmission performed gradually over three microcontrollers. the maximum transmission time on (a) unsigned long integer using parallel connection is 630 μs, tree is 700 μs, and series is 1,930 μs, (b) long integer using parallel connection is 1,880 μs, tree is 1,930 μs, and series is 5,640 μs, (c) float using parallel connection is 7,830 μs, tree is 7,890 μs, and series is 23,540 μs. based on the above experiments results, in order to maximize the range of available data and to minimize the transmission time, the following data type selection is recommended: in the case of transferred data is positive integers, then use unsigned long integer type. if transfered data is negative and positive integers, long integer type is preferable to be used. finally, the float type should be used when the transferred data has fractions. iv. conclusion a 32-bit data transmission among microcontrollers using an 8-bit port can be realized by using the algorithm described in this paper. the data types used are long integer, figure 17. unsigned long int type data transmission time figure 18. long int type data transmission time figure 19. float type data transmission time 0 500 1000 1500 2000 2500 0 1,000,000,000 2,000,000,000 3,000,000,000 4,000,000,000 5,000,000,000 t im e  ( µ s) value tree parallel series 0 1000 2000 3000 4000 5000 6000 ‐3,000,000,000 ‐2,000,000,000 ‐1,000,000,000 0 1,000,000,000 2,000,000,000 3,000,000,000 t im e  ( µ s) value tree parallel series 0 5000 10000 15000 20000 25000 0 2 4 6 8 10 12 t im e  ( µ s) value tree parallel series m. mirdanies et al. / j. mechatron. electr. power veh. technol. 06 (2015) 75-82 82 unsigned long integer, or float types. the algorithm has been successfully implemented using the c language with codevision avr v3.10 advanced ide. it has been successfully tested for the communication among atmega32a microcontrollers. based on the experiment results, it is known that the data transmitted using 32-bit long integer, unsigned long integer, or float can be accurately received without errors or data loss. maximum transmission times between two microcontrollers for unsigned long integer, long integer, and float are 630 µs, 1,880 µs, and 7,830 µs. unsigned long integer has the fastest time of data transmission than long integer and float. maximum transmission times using four microcontrollers in parallel connection for unsigned long integer is 630 µs, long integer is 1,880 µs, and float is 7,830 µs. maximum transmission times in tree connection for unsigned long integer is 700 µs, long integer is 1,930 µs, and float is 7,890 µs. maximum transmission times in series connection for unsigned long integer is 1,930 µs, long integer is 5,640 µs, and float is 23,540 µs. acknowledgement authors would like to thank to rifa rahmayanti and the research centre for electrical power and mechatronics indonesian institute of sciences (lipi) that has supported this research and all those who have helped conducting this research. references [1] r. p. saputra et al., "dc brushless motor control design and preliminary testing for independent 4-wheel drive rev-11 robotic platform," journal of mechatronics, electrical power, and vehicular technology, vol. 2, no. 2, dec 2011, pp. 8594. [2] m. mirdanies and r. p. saputra, "control system of solar tracking mechanism using combination of astronomy algorithm and light sensor," in seminar nasional rekayasa energi, mekatronik, dan teknologi kendaraan (rimtek 2013), bandung, 2013, pp. 213-222. [3] m. r. reddy et al., "touch screen and zigbee based wireless communication assistant," international journal of combined research & development (ijcrd), vol. 1, no. 4, aug 2013, pp. 6-10. [4] d. s. thakur and a. sharma, "voice recognition wireless home automation system based on zigbee," iosr journal of electronics and communication engineering (iosr-jece), vol. 6, no. 1, june 2013, pp. 65-75. [5] m. leeman et al., "bridging the educational gap in embedded systems curricula: developing an e-commerce audio streaming system," in ninth annual ieee international conference and workshop on the engineering of computer-based systems, lund, 2002, pp. 211-220. [6] m. solanke et al., "automatic override of speed and brake control and abs system," international journal of thesis projects and dissertations (ijtpd), vol. 2, no. 2, june 2014, pp. 04-08. [7] p. w. prickett et al., "a microcontrollerbased end milling cutter monitoring and management system," the international journal of advanced manufacturing technology, vol. 55, no. 9, aug, 2011, pp. 855–867. [8] a. kutlu, "microlab: a web-based multiuser remote microcontroller laboratory for engineering education*," international journal of engineering education, 2004, pp. 879-885. [9] mikro elektronika, "port expander manual," zemun, manual book 2014. [10] c. pozrikidis, introduction to c++ programming and graphics, 1st ed. university of california, san diego: springer science+business media, llc, 2007. [11] atmel. (2015, oct.) atmega32a 8-bit avr microcontroller datasheet complete. [online]. http://www.atmel.com/images/atmel-81558-bit-microcontroller-avratmega32a_datasheet.pdf [12] ieee, "ieee standard floating-point arithmetic," ieee std 754-2008, aug 2008, pp. 1-58. [13] microsoft. (2014) floating point types. [online]. https://msdn.microsoft.com/enus/library/aa691146%28v=vs.71%29.aspx mev mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.9-16 experimental investigation of 2 nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palm on performance and exhaust emission of si engine yanuandri putrasari a, *, haznan abimanyu b , achmad praptijanto a , arifin nur a , yan irawan b , sabar pangihutan simanungkalit b a internal combustion engine laboratory, research centre for electrical power and mechatronics, indonesian institute of sciences komplek lipi, jl. cisitu no.21/154d, bandung 40135 indonesia b research center for chemistry, indonesian institute of sciences puspitek, serpong, banten, 15314 indonesia received 09 march 2014; received in revised form 24 april 2014; accepted 25 april 2014 published online 23 july 2014 abstract the experimental investigation of 2nd generation bioethanol derived from efb of oil-palm blended with gasoline for 10, 20, 25% by volume and pure gasoline were conducted on performance and exhaust emission tests of si engine. a four stroke, four cylinders, programmed fuel injection (pgmfi), 16 valves variable valve timing and electronic lift control (vtec), single overhead camshaft (sohc), and 1,497 cm 3 si engine (honda/l15a) was used in this investigation. engine performance test was carried out for brake torque, power, and fuel consumption. the exhaust emission was analyzed for carbon monoxide (co) and hydrocarbon (hc). the engine was operated on speed range from1,500 until 4,500 rev/min with 85% throttle opening position. the results showed that the highest brake torque of bioethanol blends achieved by 10% bioethanol content at 3,000 to 4,500 rpm, the brake power was greater than pure gasoline at 3,500 to 4,500 rpm for 10% bioethanol, and bioethanol-gasoline blends of 10 and 20% resulted greater bsfc than pure gasoline at low speed from 1,500 to 3,500 rpm. the trend of co and hc emissions tended to decrease when the engine speed increased. keywords: bioethanol, si engine, performance, emission. i. introduction ethanol has been proposed and used as a fuel for vehicle engines since the 18 th century [1]. ethanol is the most suited fuel for spark-ignition (si) engine with several advantages over gasoline, such as it can be produced from renewable energy source, it has better anti-knock characteristics, and the combustion resulting lower exhaust emission [2, 3]. it was reported that henry ford presented it as the fuel chosen for his automobiles during their earliest stages of development [1]. due to the higher ethanol fuel grade production cost relative to gasoline, over several decades, the utilization of gasoline in spark-ignition engine is preferably. although the properties of ethanol is nearer to gasoline than diesel fuel, the research and development of ethanol utilization both for si and compression ignition (ci) engine have been carried out by many internal combustion engine researchers previously [3-28]. physical and chemical properties of the fuel indicate its quality to be combusted in an engine, which influence performance and emission characteristics of the engine. a comparison between the properties of ethanol and gasoline is shown in table 1. due to its properties, ethanol can be used on si engine without modification by blending it with gasoline to obtain lower concentrations of ethanol. pure ethanol can be used in si engines but some modifications to the engine is necessary [2, 29]. al-hasan [1] studied the effect of 99% purity ethanol-unleaded gasoline blends ranging from 0% to 25% with an increment of 2.5% on performance and exhaust emission of four stroke, 1,452 cm 3 , and 9:1 compression ratio toyota si engine. the results showed that 20% ethanol fuel blend gave the best results of the engine performance and exhaust emissions. then, the * corresponding author.tel: +62-82120136976 e-mail: yanuandri.putrasari@lipi.go.id http://dx.doi.org/10.14203/j.mev.2014.v5.9-16 y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 10 addition of 25% ethanol to the unleaded gasoline did not give any problem during engine operation. bayraktar [29] used single-cylinder, four stroke and swept volume 763 cm 3 si engine, investigating performance and emission experimentally. the 93% purity of ethanol with the blends of concentrations 1.5, 3, 4.5, 6, 7.5, 9.1 and 12% (by volume) were used as fuels. the results showed that the most suitable blend for si engines had been specified for 7.5% ethanol. from the emission analysis, the using of gasoline-ethanol blends in si engines was dramatically reduced the co concentrations. costa [30] investigated the influence of 10:1, 11:1 and 12:1 compression ratio of the four cylinders, eight-valves, and 1,000 cm 3 flexible fuel engine on its performance using 22% ethanol blended in gasoline and 100% hydrous ethanol. the engine was operated in the speed range from 1,500 to 6,500 rev/min. the results showed that engine torque, brake mean effective pressure (bmep) and output power substantially improved with the increasing of compression ratio at high speeds for both, e22 and hydrous ethanol. the specific fuel consumption of hydrous ethanol was higher than it of e22 in flexible fuel engine. the combustion performance of bioethanol at various blend ratios in gasoline direct injection engine had been experimentally worked by turner [24]. in this study when ethanol/gasoline blend increased from 0% to 100% compared with gasoline, the engine characteristics showed that efficiency increased and co emission reduced. recently, the development of a clean, renewable and sustainable energy system has been started and became popular in many countries [31-40]. the depletion anxiety of fossil fuel source and increasing level of air pollution caused by combustion of fossil fuel from transportation or industrial sector lead engineers and scientists to anticipate it. the one of popular developed renewable fuel is bioethanol. bioethanol is produced from the fermentation of sugars obtained from biomass. bioethanol feedstock can contain either sucrose (e.g. sugarcane, sugar beet) or starch (e.g. corn, wheat) or a lignocellulosic material (e.g. sugarcane bagasse, wood and straw, etc.) [33]. since the ethanol is produced from these kinds of feed stocks it is called bioethanol. bioethanol from sucrose or starch is known as 1 st generation bioethanol, while bioethanol from lignocellulose is named as 2 nd generation. as mentioned in the literatures above, the utilization of ethanol in si engine have been many reported. however, the utilization of ethanol derived from efb of oil-palm in si engine was not reported in literatures. therefore, this study introduced efb of oil-palm which is become great potential to be converted for the fermentative production of bioethanol due to its high cellulose content [31]. the aim of the study reported in this paper is to investigate the performance and emission of si engine using bioethanol derived from efb of oil-palm blended with gasoline varying from 0% to 25% by volume and engine speed from 1,500 to 4,500 rev/min. as has been reported that ethanol has 35% mass composition of oxygen, lower than bioethanol derived from efb of oil-palm with 42.65% mass composition of oxygen [26, 41], therefore, bioethanol from efb of oil-palm is suspected produces complete combustion on si engine. the engine setup, experimental procedures, experimental results and finally conclusions are discussed in the following sections. table 1. properties of ethanol and gasoline [26] property ethanol gasoline chemical formula c2h5oh c4-c12 composition (c, h, o) (% mass) 52, 13, 35 86, 14, 0 lower heating value (mj/kg) 26.8 42.7 density (kg/m 3 ) 790 715-765 octane number ((r+m)/2) 100 90 boiling temperature 78 25-215 laten heat vaporization (25 o c) (kj/kg) 904 380-500 self ignition temperature ( o c) 420 ≈300 stoichiometric air/fuel ratio 9.0 14.7 laminar flame speed @ 1 bar, 393k, ø= 1.1 (cm/s) ≈63 ≈52 mixture calorific value (mj/m 3 ) 3.85 3.75 lower ignition limit in air (%vol) 3.5 0.6 upper ignition limit in air (%vol) 15 8 solubility in water at 20 o c (ml/100ml h2o) fully miscible <0.1 y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 11 ii. experimental setup a. engine and instruments installation the performance and emission test were performed on a naturally aspirated, inline four cylinders and four stroke si engine honda l15a. the engine specification is shown in table 2.the engine was coupled with eddy current dynamometer manufactured by schenk, type w70 with 70 kw maximum brake power of measurements. the dynamometer was equipped with control panel type ls-2010 fitted with torque gauge, proximity sensor tachometer and potentiometer to adjust or manage required load and speed. the dynamometer was also connected to water cooling system to release the heat resulted during the braking process. to monitor the temperature of oil, water coolant in the inlet and outlet of radiator, exhaust in the outlet manifold, engine block wall and cylinder head, several of k-type temperature sensors were attached on the related area of the engine. the cylinder pressure was measured using water-cooled pressure transducer kistler 6041a. this transducer was combined with datac crank angle sensor attached on dynamometer shaft. to obtain imep value, the cylinder pressure signal and crank angle signal were processed in amplifier and data acquisition system dewetron dewe-2600-ca. fuel consumption was measured by using avl fuel balance type 733s. the fuel balance was equipped with driver software rs733 which was installed in a personal computer. this software could be used to take certain data in once measurement process. then the data were calculated automatically to obtain simple statistic analysis such as mean and standard deviation. the air intake flow was measured by using hotwire anemometer dn50 from technogerma system gmbh. the air flow meter was also equipped with thermometer to measure the air intake temperature. both flowmeter and thermometer value could be observed on one display monitor by pushing the switch to change over. the exhaust gas emission was measured using portable emission analyzer sukyoung ga401. the schematic diagram of engine and instruments installation is shown in figure 1. table 3. specification of 2 nd generation bioethanol derived from efb of oil-palm parameter unit, min/max test result ethanol content %-v, min 99,66 methanol content mg/l 176,4 water content %-v, max 0,2256 copper content (cu) mg/kg, max 0,001 acidity as ch3cooh mg/l, max 22,94 chloride ions content(cl ) mg/l, max 3,94 sulfur content(s) mg/l, max 15,75 gum content, washed mg/100 ml, max 0,3 figure 1. schematic diagram of engine and instruments installation table 2. engine specification engine parameter basic data model/type honda l15a/four stroke si fuel system vtec pgmfi air intake system naturally aspirated cylinder/type 4/inline number of valve 16 swept volume 1,497 cm 3 bore x stroke 73 x 89.4 mm compression ratio 10.4:1 max torque 143 nm @ 4,800 rpm max power 81kw @ 5,800 rpm y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 12 b. fuels preparation in this study, four fuel samples were investigated. a commercial gasoline called “premium” produced by pertamina tbk was used as base fuel for the preparation of all blends and was named e0. 2 nd generation bioethanol fuel grade at >99.5% purity, derived from efb of oilpalm was produced and provided by research centre for chemistry, indonesian institute of sciences. the specification of 2 nd generation bioethanol derived from efb of oil-palm was presented in table 3.the gasoline was blended with ethanol to obtain three fuel blends i.e. 10%, 20% and 25% of total volume, named e10, e20 and e25.the fuel blends were prepared just before the experimental started to ensure the homogeneity and avoid extend reaction with air or water vapor. c. testing procedure the engine was started and operated in idle for about 15 until 30 minutes to warm up and ensure it in good condition. then, the engine throttle was opened on 85% opening position. the engine load was adjusted through dynamometer control panel. the measuring loads were obtained by reducing the engine speed from 4,500, 3,000, 2,500, 2,000, and until 1,500 rpm. the engine parameters that were continuously recorded from each experiment included engine speed (rpm), brake torque (nm), fuel consumption (kg/hour), oil temperature ( o c), air mass flow (kg/hour), air temperature ( o c), and imep (bar). the room or environment condition test such as temperature ( o c), pressure (mbar), and air humidity (%) were also recorded as supporting data. from the exhaust gas emission the content of co (%), co2 (%) and hc (ppm) were measured, while, the parameters such as brake power (kw) and bsfc (g/kwh) were obtained from calculation of the recorded data. the following equations are formula for the calculation: 𝑃 = 𝑛 × 𝑇 9549 ,3 (1) 𝑏𝑠𝑓𝑐 = 𝑚 × 1000 𝑃 (2) where p is the power (kw), n is the engine speed (rpm), t is the engine torque (nm), bsfc is brake specific fuel consumption (g/kwh), and ṁ is fuel consumption (kg/h). iii. results and discussion a. brake torque the effects of bioethanol-gasoline blends on engine brake torque at 1,500 to 4,500 rpm are shown in figure 2. it can be seen that all the fuels had similar trends of brake torque. in other word, the brake torque characteristics of the engine were very similar when using pure gasoline compared to bioethanol-gasoline blends. even though it has been reported that the ethanol addition decreased the heating value of gasoline[2], in this result there were no significant influence to engine brake torque. it may be explained that the bioethanol blends increased the oxygen content in the fuel and produced better combustion. but, it is possible that the octane number of the fuel blends not appropriate with the engine compression ratio. therefore, the engine brake torque was not significantly influenced. from the four types of fuels the highest brake torque was obtained at e25 when the engine was operated at low speed from 1,500 to 2,500 rpm. the opposite from that, at e25, when the engine was operated at high speed from 3,000 to 4,500 rpm the brake torque tended to decrease. the highest brake torque of high speed was obtained when engine operated using e10.the brake torque of e20 also decreased at high speed from 3,000 to 4,500 rpm. b. brake power the effect of bioethanol blends on brake power is illustrated in figure 3. generally, the brake power characteristics of the engine were figure 3. the effect of bioethanol blends on brake power figure 2. the effect of bioethanol blends on brake torque y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 13 similar when using gasoline compared to bioethanol blends. this behavior agreed with that of the brake torque shown in figure 2. as shown in the figure, 10% ethanol-gasoline blends, e10, enhanced the engine brake power greater than gasoline at 3,500 to 4,500 rpm. meanwhile, the e20 and e25 showed lower engine brake power than that of gasoline at 3,500 to 4,500 rpm. the 10% bioethanol addition might be the optimal blend for increasing the brake power and be an appropriate blend for the engine compression ratio in this study. as explained by bayraktar [29], ethanol addition to gasoline caused the engine operation leaner and improved engine complete combustion thereby, increasing the engine performance. c. bsfc figure 4 represents the effect of bioethanol blends on bsfc. the bsfc was calculated by divided fuel consumption measurement with brake power. it could be seen from the figure that at low speed from 1,500 to 3,500 rpm the bsfc of e10 and e25 were greater than that of pure gasoline e0. the results were in accordance with the finding of koc et al. [2], where the lower energy content of ethanol-gasoline blends caused some increment in bsfc of the engine when it was used without any modification. the increment mainly depended on the percentage of ethanol. other reason could be explained by bayraktar [29] that ethanol addition reduced the heating value of the bioethanolgasoline blends, therefore, more fuel (by mass) was needed to obtain some power when blended fuels were used instead of gasoline. to produce same power at the same condition more blends were needed. the fuel consumption also depended on engine compression ratio. the higher engine compression ratio caused the lower fuel consumption. the bsfc of e20 increased at high engine speed from 3,500 to 4,500 rpm. meanwhile, the bsfc of e10 and e25 decreased. it was possible that the bioethanol gasoline blends 20% suspected as optimal blends and appropriate to be used for 10,4:1 engine compression ratio at high speed operation. d. carbon monoxide (co) figure 5 shows the effect of bioethanol blends on the emission of co. even though the three bioethanol blends showed greater co emission than gasoline, the co emission trend tended to decrease when the engine speed increased. the better trend of co was obtained from 20% ethanol-gasoline blends. it could be seen that the co emission trend dramatically decreased when engine speed increased from 1,500 to 4,500 rpm. it was possible and could be predicted from the trend if the engine speed increased more than 4,500 rpm the co emission from all fuel blends would be lower than that from pure gasoline. the co content was always present in the exhaust gas even at lean mixture due to dissociation of fuel mixture[2]. the concentration of co emissions was greatly depended on the operating condition of engine and air fuel ratio. the higher co content at low engine speed might be caused by the lower charge temperatures in cylinder which could affect fuel vaporation and the lower co content was achieved at high engine speed due to the higher charge temperatures obtained. this condition was in accordance with venugopal study [26]. the other reason was explained by s.h. yoon [28], that this might be due to the evaporation decreasing and the mixing of fuel under low temperature. therefore, low temperature combustion depressed the hydrocarbon oxidization and created higher co emissions. e. hydrocarbon (hc) the effect of bioethanol blends on hc emission is shown in figure 6. the trend showed that hc concentration of all fuel decreased when the engine speed increased. the hc concentration of bioethanol blends that was lower than pure gasoline occurred on e25. this might be resulted from leaning affect and oxygen figure 4. the effect of bioethanol blends on bsfc figure 5. the effect of bioethanol blends on co emissions y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 14 enrichment caused by bioethanol addition. the reason for the concentration reducing of hc emissions was that ethanol contains higher oxygen content in the fuel[28]. iv. conclusion in this paper, the experimental investigation of bioethanol derived from empty-fruit-bunch of oil-palm-gasoline blends for 10%, 20%, 25% and pure gasoline were conducted on si engine. the results were obtained and concluded as follows: 1. the highest brake torque of bioethanol blends was resulted from 10% ethanol content at 3,000 to 4,500 rpm engine speed. it could be explained that the bioethanol blends increased the oxygen content in the fuel and produced better combustion at 3,000 to 4,500 rpm. 2. the 10% bioethanol-gasoline blends enhanced the engine brake power greater than gasoline at 3,500 to 4,500 rpm. the 10% bioethanol addition was possible suspected as optimal blends for increasing the brake power and was an appropriate blend for the engine compression ratio in this study. 3. bioethanol-gasoline blends 10 and 20% at low speed from 1,500 to 3,500 rpm resulted greater bsfc than pure gasoline. it could be explained that the lower energy content of ethanol-gasoline blends caused some increment in bsfc of the engine when it was used without any modification. 4. the co emission trend of bioethanol blends tended to decrease when the engine speed increased. 5. the hc concentration trend of bioethanol blends showed decreased when the engine speed increased. acknowledgement this study was conducted in internal combustion engine laboratory of research centre for electrical power and mechatronics and was funded by research centre for chemistry through the kompetitif lipi 2013 research project. the authors would like to acknowledge the assistance of mr. bambang wahono, m. eng, mr. ahmad dimyani, st. and mr. mulia pratama, st. references [1] m. al-hasan, "effect of ethanol-unleaded gasoline blends on engine performance and exhaust emission," energy conversion and management, vol. 44, pp. 1547-1561, 2003. [2] m. koç, et al., "the effects of ethanol– unleaded gasoline blends on engine performance and exhaust emissions in a spark-ignition engine," renewable energy, vol. 34, pp. 2101-2106, 2009. [3] f. yüksel and b. yüksel, "the use of ethanol–gasoline blend as a fuel in an si engine," renewable energy, vol. 29, pp. 1181-1191, 2004. [4] arifin nur, et al., "the effect of ethanoldiesel blends on the performance of a direct injection diesel engine," mechatronics, electrical power, and vehicular technology, vol. 03, pp. 49-56, 2012. [5] y. putrasari, et al., "performance and emission characteristic on a two cylinder di diesel engine fuelled with ethanoldiesel blends," energy procedia, vol. 32, pp. 21-30, 2013. [6] l. pidol, et al., "ethanol–biodiesel–diesel fuel blends: performances and emissions in conventional diesel and advanced low temperature combustions," fuel, vol. 93, pp. 329-338, 2012. [7] c. gong, et al., "cycle-by-cycle combustion variation in a disi engine fueled with methanol," fuel, vol. 90, pp. 2817-2819, 2011. [8] j. huang, et al., "experimental investigation on the performance and emissions of a diesel engine fuelled with ethanol–diesel blends," applied thermal engineering, vol. 29, pp. 2484-2490, 2009. [9] d. b. hulwan and s. v. joshi, "performance, emission and combustion characteristic of a multicylinder di diesel engine running on diesel–ethanol–biodiesel blends of high ethanol content," applied energy, vol. 88, pp. 5042-5055, 2011. [10] j. lei, et al., "a novel emulsifier for ethanol–diesel blends and its effect on performance and emissions of diesel engine," fuel, vol. 93, pp. 305-311, 2012. [11] c. d. rakopoulos, et al., "experimental heat release analysis and emissions of a hsdi diesel engine fueled with ethanol– figure 6. the effect of bioethanol blends on hc emissions y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 15 diesel fuel blends," energy, vol. 32, pp. 1791-1808, 2007. [12] c. d. rakopoulos, et al., "multi-zone modeling of combustion and emissions formation in di diesel engine operating on ethanol–diesel fuel blends," energy conversion and management, vol. 49, pp. 625-643, 2008. [13] d. c. rakopoulos, et al., "experimentalstochastic investigation of the combustion cyclic variability in hsdi diesel engine using ethanol–diesel fuel blends," fuel, vol. 87, pp. 1478-1491, 2008. [14] d. c. rakopoulos, et al., "effects of ethanol–diesel fuel blends on the performance and exhaust emissions of heavy duty di diesel engine," energy conversion and management, vol. 49, pp. 3155-3162, 2008. [15] d. c. rakopoulos, et al., "combustion heat release analysis of ethanol or n-butanol diesel fuel blends in heavy-duty di diesel engine," fuel, vol. 90, pp. 1855-1867, 2011. [16] a. kyriakides, et al., "evaluation of gasoline–ethanol–water ternary mixtures used as a fuel for an otto engine," fuel, vol. 108, pp. 208-215, 2013. [17] a. a. martins, et al., "cold start and full cycle emissions from a flexible fuel vehicle operating with natural gas, ethanol and gasoline," journal of natural gas science and engineering, vol. 17, pp. 94-98, 2014. [18] m. c. roberts, "e85 and fuel efficiency: an empirical analysis of 2007 epa test data," energy policy, vol. 36, pp. 1233-1235, 2008. [19] m. rocha and j. simoesmoreira, "a simple impedance method for determining ethanol and regular gasoline mixtures mass contents," fuel, vol. 84, pp. 447-452, 2005. [20] i. schifter, et al., "combustion characterization in a single cylinder engine with mid-level hydrated ethanol–gasoline blended fuels," fuel, vol. 103, pp. 292-298, 2013. [21] i. schifter, et al., "combustion and emissions behavior for ethanol–gasoline blends in a single cylinder engine," fuel, vol. 90, pp. 3586-3592, 2011. [22] t. topgül, et al., "the effects of ethanol– unleaded gasoline blends and ignition timing on engine performance and exhaust emissions," renewable energy, vol. 31, pp. 2534-2542, 2006. [23] n. türköz, et al., "experimental investigation of the effect of e85 on engine performance and emissions under various ignition timings," fuel, vol. 115, pp. 826832, 2014. [24] d. turner, et al., "combustion performance of bio-ethanol at various blend ratios in a gasoline direct injection engine," fuel, vol. 90, pp. 1999-2006, 2011. [25] j. vancoillie, et al., "the potential of methanol as a fuel for flex-fuel and dedicated spark-ignition engines," applied energy, vol. 102, pp. 140-149, 2013. [26] t. venugopal and a. ramesh, "experimental studies on the effect of injection timing in a si engine using dual injection of n-butanol and gasoline in the intake port," fuel, vol. 115, pp. 295-305, 2014. [27] x. wu, et al., "dual-injection: the flexible, bi-fuel concept for spark-ignition engines fuelled with various gasoline and biofuel blends," applied energy, vol. 88, pp. 23052314, 2011. [28] s. h. yoon and c. s. lee, "effect of undiluted bioethanol on combustion and emissions reduction in a si engine at various charge air conditions," fuel, vol. 97, pp. 887-890, 2012. [29] h. bayraktar, "experimental and theoretical investigation of using gasoline–ethanol blends in spark-ignition engines," renewable energy, vol. 30, pp. 1733-1747, 2005. [30] r. c. costa and j. r. sodré, "compression ratio effects on an ethanol/gasoline fuelled engine performance," applied thermal engineering, vol. 31, pp. 278-283, 2011. [31] y. sudiyani, et al., "utilization of biomass waste empty fruit bunch fiber of palm oil for bioethanol production using pilot–scale unit," energy procedia, vol. 32, pp. 31-38, 2013. [32] g. p. hammond, et al., "development of biofuels for the uk automotive market," applied energy, vol. 85, pp. 506-515, 2008. [33] m. o. s. dias, et al., "production of bioethanol and other bio-based materials from sugarcane bagasse: integration to conventional bioethanol production process," chemical engineering research and design, vol. 87, pp. 1206-1216, 2009. [34] n. h. ravindranath, et al., "biofuel production and implications for land use, food production and environment in india," energy policy, vol. 39, pp. 5737-5745, 2011. [35] s. k. wahono, et al., "characterization and utilization of gunungkidul natural zeolite y. putrasari et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 9-16 16 for bioethanol dehydration," energy procedia, vol. 47, pp. 263-267, 2014. [36] d. setyarini, et al., "determination of organic impurities in lignocellulosic bioethanol product by gc-fid," energy procedia, vol. 32, pp. 153-159, 2013. [37] m. m. ishola, et al., "biofuels in nigeria: a critical and strategic evaluation," renewable energy, vol. 55, pp. 554-560, 2013. [38] r. janssen and d. d. rutz, "sustainability of biofuels in latin america: risks and opportunities," energy policy, vol. 39, pp. 5717-5725, 2011. [39] a. kristiani, et al., "effect of pretreatment process by using diluted acid to characteristic of oil palm's frond," energy procedia, vol. 32, pp. 183-189, 2013. [40] g. najafi, et al., "potential of bioethanol production from agricultural wastes in iran," renewable and sustainable energy reviews, vol. 13, pp. 1418-1427, 2009. [41] s. kerdsuwan and k. laohalidanond, "renewable energy from palm oil empty fruit bunch," in renewable energy trends and applications, d. m. nayeripour, ed., ed available from: http://www.intechopen.com/books/renewabl e-energy-trends-andapplications/renewableenergy-from-palm-oil-empty-fruit-bunch: intech, 2011. mev mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.89-98 economic analysis of cikaso mini hydro power plant as a cdm project for increasing irr irhan febijanto * centre for technology of energy resources development, deputy for technology of informatic, energy and mineralbppt, cluster 5 of energy building, puspiptek serpong, tangerang selatan 15314 received 18 august 2013; received in revised form 31 october 2013; accepted 31 october 2013 published online 24 december 2013 abstract renewable energy fueled power generations are few developed by private sector in indonesia. high-cost investment and low electricity selling price to pt pln as a single buyer is main barriers for private sector to involve in the development of renewable energy fueled power generations. in this project, the economic feasibility of mini hydro power plant of cikaso with capacity of 5.3 mw, located at sukabumi regency, west java province was assessed. this project utilized revenue generated from carbon market to increase the economic feasibility. procedure to register the project to united nation for climate change convention (unfccc) as a clean development mechanism project was explained in detail. approved consolidation methodology (acm) 0002 version 12.3.0 was used to calculate grid emission factor in jawa-bali-madura the grid electricity system. it was calculated that the grid emission factor is 0.833 (t-co2/mwh), and the carbon emission reduction generated for this project is 21,982 ton/year. from the analysis result, it can be proven that the additional revenue from carbon credit could increase the project irr from 10.28% to 13.52%. key words: mini hydro power plant, clean development mechanism, emission factor, irr. i. introduction a. background renewable energy potential in indonesia is quite large. hydro energy potential in indonesia is around 75 gw scattered over islands in indonesia. until now, only 4000 kw from the potential has been utilized as a power plant [1]. the utilization of mini hydro (over than 1 mw), micro hydro (10 kw – 1 mw) and pico hydro (below 10 kw) is suitable for remote areas and the area where pt perusahaan listrik negara (hereinafter referred as to ”pln”) persero’s electric grid is not yet built. pln is the stateowned electric power company, which has a role as a single buyer in the electricity business in indonesia [2]. indonesia government has targeted ratio of renewable energy to be 2.5% from all energy consumption in 2025. regarding green house gas (hereinafter referred as to ”ghg”) reduction, indonesia’s government has planned to reduce 26% of ghgs in 2020 [3]. despite policy and target for supporting renewable energy development have been implemented. investors of renewable energy power plants still get a constrains on economic problems within the project. unlike other countries, although the incentive for supporting renewable energy development has been implemented, however, the benefit still not be felt by investors. the incentive for renewable energy regarding electricity tariff for selling to pln was determined by regulation of ministry of energy and mineral resources in the year of 2002, 2006, and 2009 [4, 5, 6]. despite the electricity tariff determined in 2009 relative closes to the economic price of the renewable energy project. however, it is not applicable to a hydro power plant project. renewable energy based power plant is not economic. it is one reason why private sector is not interested to involve in it an investment in * corresponding author.tel: (021) 75791355 e-mail: irhan.febijanto@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.89-98 i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 90 indonesia. development of the hydro power plants in remote areas needs high investment cost. besides that the electricity selling price must compete with the electricity selling price of fossil fuel based power plant that gets a subsidy. this is another reason, why renewable energy based power plant is not a lot of built in indonesia [7]. clean development mechanism (hereinafter referred as to ”cdm”) is one of the mechanism of kyoto protocol as an attempt to reduce green house gasses [8] (hereinafter referred to as ”ghg”) such gas of co2, n2o, ch4, and so on. the reduction emission amount refers to the ghg amount generated by every country during a year of 1990. cdm has been implemented throughout the world since 1997, however, the implementation number in indonesia is less compared to other countries in asia such as india and china. ratification of cdm by indonesian government has been done in 2004, signed by the president of republic of indonesia. through cdm, developed countries (member of annex i) collaborate with these countries to reduce ghgs emission. the benefit of cdm program for developing countries includes: (1) flow of the foreign fund which could help financial of a domestic project; (2) participation of foreign investors for the project which could minimize the risk to local developers; (3) possibility of transfer technology that could help domestic technology development in domestic; (4) loan rate from a foreign bank usually that has a lower rate compared to domestic bank rate. among the benefits of cdm project above, lower bank loan rate is the most interesting factor for the local developers. for developed countries, cdm is the mechanism for reducing ghg with low cost compared to develop the project activity in their country. cdm itself has procedures determined by united frameworks for convention climate change (hereinafter referred as to”unfccc”). the procedures should be conducted in order for approved officially by unfccc as an entity that provides a certificate for cdm project. each step conducted in the cdm procedures may need a time more than one year. basically, all procedures implemented on the project should be clarified whether the project can reduce ghg emission exactly and in line with the determined methodology. one of the conditions that a project can be implemented as cdm project, if the project economic can be increased using additional revenue from selling carbon credit. project economic is a value of internal rate return (hereinafter referred as to ”irr”). cdm is one of the mechanisms that can reduce unfeasible economic factors of the renewable power generation project. the renewable power generation is a project than can reduce carbon emission generated from fossilfuel power generation plant connected by the grid electricity system in a certain area. revenue from selling carbon credit can be extra revenue, and usually for hydro power plant the additional revenue increases irr value around 1-2% more, and also grosses revenue around 10-20%. pt bumiloka cikaso energi has conducted the investigation of hydro power potential and found the hydro potential in curug luhur water fall in cikaso river, in west java province. the investigation result concluded that the river in that area has a potential to generate electric power. this project utilizes potential energy generated from height differences between cikaso river and curug luhur (luhur waterfall) (see figure 1). after reaching the optimum head, the flow is returned to the cikaso river from the river bank having height differences of 40 m with the cikaso river. using penstock the water flow is returned to the river through turbine. the potential energy is converted to mechanical energy by three units of turbines, and then it is converted to the electric energy by three units of generators. table 1 shows the specification of cikaso small scale hydro power plant (hereinafter referred to as ”sshpp”). the lowest of turbine capacity of 0.8 mw is used especially in the dry season when the water flow decrease drastically. during the rainy season, all of three turbines can be operated at full capacity of 5.3 mw. rocky condition of the site leads to high investment cost, especially the cost for developing water channel toward to turbine became several times higher compared to the normal condition. based on feasibility study figure 1. site condition i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 91 report that has been completed in 2009, it can be concluded that this project has irr value of 10.28%. it is lower than a benchmark that determined based on the lowest rate of working capital rate of 12.22% issued by bank of indonesia in 2009. the project investment is rp 122.2 billion funded by 100% owner equity. in order to increase the feasibility level to the project, it is needed to add additional revenue through cdm mechanism for this project. for this purpose, this project activity would be submitted as cdm project and it was planned to be registered in unfccc. certification of this project activity can be sold, and it can generate additional revenue besides the main revenue from selling electricity to pln. b. purpose this paper describes the grid emission factors (hereinafter referred as to ”ef”) calculation for jawa-bali-madura grid electricity system (hereinafter referred as to ”jamali system”). using the ef, the ghg reduction generated from this project activity can be calculated annually. the economy of cikaso small scale hydro power plant (hereinafter referred as to ”sshpp”) as the cdm project is calculated by considering the additional revenue from selling credit carbon. the economic condition with and without the additional revenue are compared. the economic feasibility of the project is compared using the conservative benchmark at that time. ii. methodology a. green house gas calculation grid ef in this project activity is calculated using methodology determined by unfccc. two methodologies are category of i-d:”grid connected renewable electricity generation” [8], ver. 16 and acm (approved consolidation methodology) 0002 version 12.3.0, “consolidated methodology for grid-connected electricity generation from renewable sources” [9]. using both methodologies, the electricity amount exported to the grid is converted to the emission reduction amount, and then based on the carbon market price, the additional revenue is calculated. project boundary is determined based on the methodology as illustrated in figure 2 [8]. this figure indicates that the emission reduction activity is limited to the activities related to the cikaso sshpp only. in this project activity, small part of generated electricity is utilized for auxiliary equipments and the remaining is exported to the grid owned by pln of west java region. the difference between both electricity amounts is net electricity that used in the in the emission reduction calculation. the data used during the determination of ef is all electricity generated by all power plants connected by the jamali system and all fuel consumption used in the all power plant during 2001-2005 [10-15]. based on acm 0002 [9], ef value is calculated by average value of the latest three years of data used during the determination of ef, 2003-2005 [12-15]. jamali system is the interconnection electricity system in jawa, madura and bali island. based on ams-i.d [8], baseline emission, bey, is obtained by multiplying net of electricity, egy, by the grid emission factor within the system, efy. equation of be is indicated in equation (1). 𝐵𝐵𝐸𝐸𝑦𝑦 = 𝐸𝐸𝐺𝐺𝑦𝑦 𝑥𝑥 𝐸𝐸𝐹𝐹𝑦𝑦 (1) where bey is baseline emission (tco2 e) in year y, egy is quantity of net electricity generation that is produced and fed through the system as a result of the implementation of the cdm project table 1. cikaso sshpp specification item unit value installed total capacity mw 5.3 installed capacity each unit mw 2 x 2.25 1 x 0.8 average of exported energy to the grid annually mwh 26,390 capacity factor % 58 head m 40 water flow m3/s 16.5 unit number 3 turbine type horizontal francis figure 2. project boundary project boundary electricity stream electricity to jamali grid electricity to end-user cikaso sshpp auxiliary consumption i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 92 activity in the year y, and efy is emision factor (tco2 e). prior bey calculation, parameters used in the steps below should be determined [16]. 1) step 1; determination of operating margin emission factor simple operating (om) is selected for the emission factor calculation with the reason as follows. • dispatch data analysis emission factor is unable to be implemented, because required data cannot be published • number of plants which includes the category of “low-cost and must-run/lcmr” power generation plan is below of 50% compared to total of power generations connected to jamali system during five years (2005-2009). in this case, numbers of lcmr power plants are five units of power plant in 2005 and 2006, six units of power plant in 2007 and 2008, and seven units of power plant in 2009. calculation of simple operating margin (efom ,y) uses equation (2) as follows. 𝐸𝐸𝐹𝐹𝑂𝑂𝑂𝑂,𝑎𝑎𝑣𝑣𝑣𝑣𝑣𝑣𝑎𝑎𝑣𝑣𝑣𝑣 ,𝑦𝑦 � 𝑡𝑡𝑡𝑡𝑂𝑂2 𝑂𝑂𝑀𝑀ℎ � = ∑ (𝐸𝐸𝐺𝐺𝑚𝑚 ,𝑦𝑦 𝑥𝑥 𝐸𝐸𝐹𝐹𝐸𝐸𝐸𝐸 ,𝑚𝑚 ,𝑦𝑦 )𝑚𝑚 ∑ 𝐸𝐸𝐺𝐺𝑚𝑚 ,𝑦𝑦𝑚𝑚 (2) where egm,y, is net quantity of electricity generated and delivered to the grid by power unit m in the year y (mwh), efel,m,yis co2 emission factor of power unit m in the year y (tco2/mwh), m is power unit included in the operated margin, and y is most recent historical years for which power generation data is available. 2) step 2; calculation of build margin emission factor build margin emission factor (efbm,y) calculation indicates an amount of co2 reductions in the absence of fossil fuel based power plant or on the delay to the development. in the efbm,y, calculation, the most recently developed a set of power plant having the highest electricity production annually is selected according to the following procedures. • the set of five power units that have been built most recently, or • the set of power capacity additions to the electricity system that comprise 20% of the system generation (in mwh) and that have been built most recently. the set of power units that comprises the larger annual generation is selected, and then build margin emission factor is calculated using the following equation (3). 𝐸𝐸𝐹𝐹𝐵𝐵𝑂𝑂,𝑦𝑦 � 𝑡𝑡𝑡𝑡𝑂𝑂2 𝑂𝑂𝑀𝑀ℎ � = ∑ 𝐹𝐹𝑖𝑖,𝑚𝑚 ,𝑦𝑦𝑖𝑖,𝑚𝑚 ∙ 𝑡𝑡𝑂𝑂𝐸𝐸𝐹𝐹𝑖𝑖,𝑚𝑚 ∑ 𝐺𝐺𝐸𝐸𝐺𝐺𝑚𝑚 ,𝑦𝑦𝑚𝑚 (3) where fi,m,y, coefi,m and genm,ycan be analogous as the same parameters which are used throughout the operating margin emission factor calculation for a set of power units, m. 3) step 3; calculation of baseline emission factor combined margin emission factor (efy) is using equation (4). 𝐸𝐸𝐹𝐹𝑦𝑦 = 𝑤𝑤𝑂𝑂𝑂𝑂 𝑥𝑥 𝐸𝐸𝐹𝐹𝑂𝑂𝑂𝑂,𝑦𝑦 + 𝑤𝑤𝐵𝐵𝑂𝑂 𝑥𝑥 𝐸𝐸𝐹𝐹𝐵𝐵𝑂𝑂,𝑦𝑦 (4) where the ratio for wom and wbm, is 50% respectively (wom= wbm= 0,5). 4) step 4. calculation of baseline emission baseline emission (bey) is calculated using equation (5): 𝐵𝐵𝐸𝐸𝑦𝑦 = 𝐸𝐸𝐺𝐺𝑦𝑦 𝑥𝑥 𝐸𝐸𝐹𝐹𝑦𝑦 (5) where egy is quantity of net electricity generation and efy is emision factor. 5) step 5. calculation of emission reduction calculation of emission reduction (ery) is using equation (6): 𝐸𝐸𝐸𝐸𝑦𝑦 = 𝐵𝐵𝐸𝐸𝑦𝑦 − 𝑃𝑃𝐸𝐸𝑦𝑦 − 𝐸𝐸𝑦𝑦 (6) this project activity is a renewable energy based power generation. therefore, there is no leakage, ly=0, and project emission, pey=0. b. economic analysis the aim to submit the project activity as cdm project is to increase the economic feasibility of the project. the internal rate return (hereinafter referred as to ”irr”) is used as an economic parameter. the value is lower than the selected benchmark. the lowest bank loan rate over the year of 2009 is taken as the benchmark. the feasibility study was completed in 2009. sensitivity analysis is calculated using ±10% of change of the following parameters, • investment cost • electricity selling prive • general administration and o&m cost the change of ±10% is considered can be represented the changes due to inflation, increase over the prices, change of water debit and other parameters that able to change parameter of (i) investment cost, (ii) selling electricity price and (iii) generation administration cost and o&m cost. the irr project is re-calculated using the additional revenue generated from selling carbon credit and then the economic feasibility of the project is re-analyzed. i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 93 iii. results and discussions a. green houses gasses emission green houses gasses emitted from power generation plant activity is carbon dioxide (hereinafter referred as to ”co2”), mainly. the amount of the ghg in jamali system rises year by year along with the increase of the coalfired power plant number as a result of implementation of the crash program i. the increase of co2 is shown in figure 3. figure 3 indicates that co2 rose sharply in 2006. the increase is caused by cilacap and tanjung jati b coal-fired power plants started to operate in that year. even, there is no new power plant operated. the consumption of coal increased gradually that resulted co2 emissions increased, in the following years. according to the methodology [8], emission factor shall be calculated using the average of the last three years of 2007, 2008 and 2009. b. calculation of emission factor ef of jamali system is calculated using equations (1), (2) and (3). coefficient emission calculation (coef) of co2 for each fuel is shown in table 2. the total amount of generated electricity within five years in the system is indicated in table 3. table 4 shows the ratio number between low cost must run (hereinafter referred as to ”lcmr”) [16] power plants and total power plant connected with the system. in the table, it is indicated that within five years (2001-2005) consecutive, the ratio of lcmr power plant is lower than 50%. therefore, according to the tool, the calculation of efom shall use a simple om [16]. table 5 shows the loss generated from own consumption and generated from sub stations. the lost data used is only for 2005 and 2006, because in the following years, a net electricity production of each power plant was published. the net electricity production is an amount of figure 3. co2 emitted from coal fired power plant in jamali system during 2004-2010 [17] table 2. fuel specification fuel type (a) (b) ( c) (d) (e) (f) (g) calorie value carbon content standard oxidized carbon factor standard carbon emissin, co2 specific gravity emission co2 (a)x(b)x(c) (d) x 44/12 (e) x (f) tj/kt fuel (tc/tj) tc/kt fuel tco2/kt fuel kt/k l tco2/kl fuel sources pertamina mem ipcc ipcc ipcc mfo 41.02 21.1 1 865.50 3,173.51 0.00099 3.142 hsd 42.73 20.2 1 863.12 3,164.77 0.000845 2.674 coal 24.03 26.20 1 629.61 2,308.56 natural gas 48.00 15.30 1 734.40 2,692.80 note. : hsd: high diesel speed, mfo: marine fuel oil, ipcc: intergovernmental panel on climate change; pertamina: perusahaan pertambangan minyak dan gas bumi negara/state-owned oil company of indonesia, kt fuel: kilo tonne fuel; tc: tonne carbon, tj: terra joule, kl fuel : kilo litre fuel i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 94 electricity generated deducted by the loss generated from own consumption and generated from sub stations. fuel consumption of each power plant during five years, 2005-2009 is shown in table 6. amount of ghg emitted from each kind of fuel is shown in table 7. table 8 shows efsimpleom derived from the amount of co2 emission and total amount of electricity generated during the last three years, 2007, 2008, and 2009. the value of efsimpleom was calculated using equation (4), and the result is 0.9583 (tco2/mwh). table 3. electricity generated in jamali system based on the fuel type (mwh nett) source of plant operation year 2005 2006 2007 2008 2009 fuel gwh hydro 7,023 5,309 5,930 6,251 6,635 diesel oil 128 101 87 173 121 gas turbine gas 2,603 2,038 2,126 3,073 4,688 oil 2,547 2,087 1,958 2,191 3,275 geothermal 6,185 6,183 6,672 7,337 8,188 steam coal 45,477 51,826 57,206 54,140 56,965 gas 646 669 941 690 563 oil 6,673 7,171 7,685 8,274 7,301 combined cycle gas 16,559 6,193 17,929 18,953 20,301 oil 8,980 8,444 7,192 10,505 7,527 total net production 96,821 100,021 107,726 111,586 115,564 tabel 4. ratio of low cost and must run power of power plant in the last 5 years (2005 2009) item units 2005 2006 2007 2008 2009 total generation net gwh (net) 83,436 88,351 95,124 97,999 100,741 low cost and must-run generation gwh (net) 13,385 11,670 12,603 13,588 14,823 low cost and must-run generation/ total generation % 16% 13% 13% 14% 15% table 5. lost ratio year 2005 2006 average losses in java-bali system due to own consumption 3.94% 4.21% table 6. fuel consumption in the grid during 2005-2009 fuel type unit 2005 2006 2007 2008 2009 hsd kilo litre 4,406,883 3,623,332 3,498,197 4,031,017 2,781,649 mfo kilo litre 1,944,142 2,054,365 2,225,317 2,374,577 2,150,386 ido kilo litre 4,074 2,343 2,306 4,401 gas mmbtu 136,744,924 141,147,996 145,991,700 167,844,288 219,008,065 coal ton 24,524,261 26,860,205 29,584,714 28,353,988 29,409,721 table 7. co2 emission in jamali grid system during 2005-2009 year 2005 2006 2007 2008 2009 fuel type t-co2 hsd 11,785,015 9,689,620 9,354,980 10,779,863 7,438,768 mfo 6,108,049 6,454,344 6,991,436 7,460,377 6,756,020 ido 11,142 6,408 6,307 12,037 gas 8,093,881 8,354,497 8,641,195 9,934,641 63,006 coal 6,615,701 62,008,365 68,298,053 65,456,849 67,524,209 total 82,613,788 6,513,234 93,291,971 93,643,767 94,682,002 i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 95 efbm calculation is conducted after determined the most recently developed a set of power plant having the highest electricity generated annually. two groups of power plants were determined according to step 2. the first group consisted of five units the most recently developed power plant, and the second group consisted of power plant generating electricity with the amount ratio of 20% from total electricity generated within the system. the highest electricity generated from both groups that consist of power plants producing electricity in amount of 20% from the total in 2009 was selected, as shown in table 9. table 10 to table 12 indicates electricity generated and fuel consumption in 2009 from a group of power plants having electricity generated of 20% from total electricity generated inside the system. using equation (2), efbm is 0.7075 (t-co2/mwh). using equation (3), ef2005 is 0.833 (t-co2/mwh). c. emission reduction, (ery) er in this project activity is calculated using equation (4) and equation (5). ly=pey=0, and then emission reduction of co2 resulted from operation of cikaso sshpp is 21,982 tco2/yr. d. economic analysis the calculation results of sensivity analysis are shown in figure 4. x-axis and y-axis indicates the amount of parameter change and irr value. in the figure, benchmark line of 12.22%, selling electricity price, investment cost, and general administration cost and o&m cost is indicated by symbol of (x), (■), (◆) and (▲), respectively. the selected benchmark used throughout the calculation is the conservative bank loan rate in 2009 when the feasibility study completed. change of three parameters within the amount of ±10% shows irr is still below than the benchmark value. it can be concluded that the figure 4. irr project and the benchmark 5.00% 6.00% 7.00% 8.00% 9.00% 10.00% 11.00% 12.00% 13.00% -１０％ base case ＋１０％ ir r table 8. operating margin emission factor during in the last three years (2007-2009) item unit 2007 2008 2009 total total emissions tco2 e 93,291,971 93,643,767 94,682,002 281,617,740 total generation mwh (net) 95,123,861 97,998,684 100,741,000 293,863,545 efom tco2 e/mwh 0.958 table 9. two groups of power plant using to determine build margin emission factor sample group (m) classification “the five power plants that have been built recently” (gwh) “the power plants capacity addition to the electricity system that comprises 20% of system generation ( in gwh) and that have been built most recently” comments electricity quantity 12,578.0 25,660 total generation is 115,564 (gwh) in jamali grid proportion (ratio to total generation in jamali grid) 10.88% 22.20% selected group o i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 96 change of three parameters doesn’t give an effect to the feasibility of the project to be unfeasible. the assumption of cer (certified emission reduction) is 13 euro/t-co2 for 30 years. the calculation results considered the additional revenue from cer shows irr increased 3.24%, from 10.28% to 13.52% as shown in table 13. the additional revenue increased the value of irr of 13.52%. it becomes higher than the benchmark value of 12.22%. iv. conclusion according to the calculation result of economic feasibility of the project, it can be proven that the additional revenue generated from carbon credit could increase the project irr table 10. sample group power plant for build margin calculation (part 1) no. power plant fuel type opera tion year capa city generated power thermal eff. actual data calculation data mw mwh gj/gw/h owner power plant a c c=axbx 8760/1000 d 1 pt java power paiton ii #6 steam-coal 2000 1220 4541.7 0.00 2 pt geo dipa energi dieng geothermal 2002 50 93.0 0.00 3 pt cikarang listrindo power cikarang gt-gas 2003 150 1043.0 9119.04 4 pt krakatau daya listrik krakatau steam-coal 2003 0 2.0 9235.95 5 muara tawar block 3 & 4 gt-gas 2004 840 3555.0 9119.04 6 block 3 & 4 gt-oil 2004 840 351.0 9119.04 7 pt sumberenergi sakti prima cilacap #1 steam-coal 2006 562 3496.0 9235.95 8 cilacap #2 steam-coal 2006 562 3496.0 0.00 9 tanjung jati b unit #1 steam-coal 2006 660 8226.0 9235.95 10 unit #2 steam-coal 2006 660 8226.0 0.00 11 cilegon cilegon ccgt-gas 2006 740 3916.0 6003.37 12 indorama indorama steam-coal 2007 50 0.0 9235.95 13 pln labuhan steam-coal 2009 300 436.0 9235.95 total 25,659.7 table 11. sample group power plant for build margin calculation (part 2) no. power plant ncv fuel consumption unit gj/k t fuel gj/k ltr fuel actual data calculation data owner power plant e f g= cxd/e g= 1000x cxd/e 1 pt java power paiton ii #6 24,031 2 pt geo dipa energi dieng 9,014,689 mmbtu 3 pt cikarang listrindo power cikarang 769 ton 4 pt krakatau daya listrik krakatau 24,031 30,726,000 mmbtu 5 muara tawar block 3 & 4 41 78,820 kltr 6 block 3 & 4 1,899,271 ton 7 pt sumberenergi sakti prima cilacap #1 24,031 8 cilacap #2 3,620,231 ton 9 tanjung jati b unit #1 24,031 10 unit #2 22,282,040 mmbtu 11 cilegon cilegon ton 12 indorama indorama 24,031 ton 13 pln labuhan 24,031 total i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 97 from 10.28% to 13.52%. the additional revenue from carbon credit can increase the economic feasibility of a renewable energy. this mechanism is suitable for indonesian condition that still doesn’t have incentives to renewable energy power generation development. the other benefit for implementing cdm, the project can be known internationally as the project that contributes in emission reduction of ghg. it can increase the project image as a green project which contributes in ghg emission reduction. references [1] ministry of energy and mineral resources, “indonesia energy outlook 2010”, pp.39, jakarta, 2010. [2] fabby tumiwa, “switch on/switch off: lesson learn from the reform indonesia power sector”, presented at international conference on “establishing dialogue on fuel and energy sector transparency initiative” bishkek, 26-27 september 2011. [3] bappenas, guidelines of local action plan for reducing green house gasses (rangrk), jakarta, 2011. [4] ministry of energy and mineral resources, minister regulation, no: 1122 k/30/mem/2002 regarding distributed energy power plant, jakarta, 2002. [5] ministry of energy and mineral resources, minister regulation, no: 002/2006 medium scale of renewable energy generation power plant, jakarta, 2006. [6] ministry of law and human rights, indonesian law, no. 30/2009 on electricity, jakarta, 2009. [7] center for strategic & international studies, a report of the csis chair for southeast asia studies and the energy national security program,” sustainable energy future in southeast asia”, pp.11, jakarta, december 2012. [8] united nation for climate change convention, ams-i d, ver.16, approved small scale methodologies, http://cdm.unfccc.int/filestorage/c/d/m/cd table 12. sample group power plant for build margin calculation (part 3) no. power plant fuel type operation year effective co2 emission factor emission reduction (tco2/gj) t-co2 owner power plant h g= (exf)xh/1000 g= exgxh 1 pt java power paiton ii #6 steam-coal 2000 4,968,464 2 pt geo dipa energi dieng geothermal 2002 0 3 pt cikarang listrindo power cikarang gt-gas 2003 0 533,576 4 pt krakatau daya listrik krakatau steam-coal 2003 0 1,775 5 muara tawar block 3 & 4 gt-gas 2004 0 1,818,661 6 block 3 & 4 gt-oil 2004 0 237 7 pt sumber energi sakti prima cilacap #1 steam-coal 2006 4,384,579 8 cilacap #2 steam-coal 2006 0 9 tanjung jati b unit #1 steam-coal 2006 8,357,517 10 unit #2 steam-coal 2006 0 11 cilegon cilegon ccgt-gas 2006 0 1,318,866 12 indorama indorama steam-coal 2007 0 13 pln labuhan steam-coal 2009 386,848 total 21,770,522 table 13. irr calculation with and without the additional revenue without additional revenue with additional revenue investment cost rp 122.2 billion benchmark 12.22% life time 30 years irr project 10.28% 13.52% i. febijanto / mechatronics, electrical power, and vehicular technology 04 (2013) 89-98 98 mwf_am_2ghdc30tpdjk04ls07sy07 x9mfzrg5/ams_i.d._ver09.pdf?t=m1v8 bxu0z3prfdaco-arwxzwkc4vvptj0w7q, accessed on october 3, 2013. [9] united nation for climate change convention, approved large scale methodologies, acm0002 ver.12.3.0, http://cdm.unfccc.int/filestorage/4/w/1/4w1 sckx3empo6aygrjutd7bq8ivn0h/ consolidated%20baseline%20methodology %20for%20gridconnected%20electricity%20generation%20 from%20renewable%20sources.pdf?t=ykt8 bxu0age5fddrp6_zxqo_0f407poidwu, accessed on october 3, 2013. [10] pt indonesia power annual statistic 2005, jakarta, 2006. [11] pt indonesia power annual statistic 2006, jakarta, 2007. [12] pt indonesia power annual statistic 2007, jakarta, 2008. [13] pt indonesia power annual statistic 2008, jakarta, 2009. [14] pt indonesia power annual statistic 2009, jakarta, 2010. [15] pt pjb, annual statistic pt pembangkit jawa bali, 2005-2009, jakarta 2010. [16] unfccc, methodological tool (version 01.1) “tool to calculate the emission factor for an electricity system”, eb 35 report annex 12 page 1, 28 july 2008. [17] rencana penyediaan tenaga listrik sistem jawa-madura-bali 2003-2010, direktorat transmisi dan distribusi pt pln (persero), jakarta, september 2003. introduction background purpose methodology green house gas calculation step 1; determination of operating margin emission factor step 2; calculation of build margin emission factor step 3; calculation of baseline emission factor step 4. calculation of baseline emission step 5. calculation of emission reduction economic analysis results and discussions green houses gasses emission calculation of emission factor emission reduction, (ery) economic analysis conclusion references j. mechatron. electr. power veh. technol 06 (2015) 19–30 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.19-30 nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung fadjar rahino triputra a,c, *, bambang riyanto trilaksono a , trio adiono a , rianto adhy sasongko b , mohamad dahsyat c a school of electrical engineering and informatics, institut teknologi bandung jl. ganesha 10, bandung, indonesia b faculty of mechanical and aerospace engineering, institut teknologi bandung jl. ganesha 10, bandung, indonesia c agency for the assessment and application of technology (bppt) komplek puspiptek serpong, tangerang, indonesia received 13 february 2015; received in revised form 30 june 2015; accepted 30 june 2015 published online 30 july 2015 abstract developing a nonlinear adaptive control system for a fixed-wing unmanned aerial vehicle (uav) requires a mathematical representation of the system dynamics analytically as a set of differential equations in the form of a strict-feedback systems. this paper presents a method for modeling a nonlinear flight dynamics of the fixed-wing uav of bppt wulung in any conditions of the flight altitude and airspeed for the first step into designing a nonlinear adaptive controller. the model was formed into 10dof differential equations in the form of strict-feedback systems which separates the terms of elevator, aileron, rudder, and throttle from the model. the model simulation results show the behavior of the flight dynamics of the wulung uav and also prove the compliance with the actual flight test results. keywords: fixed-wing uav; nonlinear flight dynamics; strict-feedback systems. i. introduction a fixed-wing unmanned aerial vehicle (uav) has many advantages to fulfill important missions in a wide range of territory. agency for the assessment and application of technology (bppt) developed a fixed-wing uav called wulung as shown in figure 1, to provide a solution of the country problem for keeping critical assets in a wide territory such as ocean and forest from disaster, illegal fishing, and illegal logging. this uav has the proficiency to carry a 20 kg payload and the flight range of 200 km from the home base for various missions such as surveillance, aerial photography, search and rescue, and weather modification. however, to meet the needs of concerned missions, an adaptive flight control is needed to drive this fixed-wing uav to the mission locations autonomously. hence, a nonlinear dynamic model of wulung uav is also needed as part of the flight control design to manage the uav flying to the mission destinations reliably and safely. afterwards, some modeling studies of wulung uav have been conducted to formulate the flight control design. formerly, the flight dynamics modeling of a fixed-wing uav in the case of bppt wulung uav [1] have been conducted using the linear systems approach [2] in which the analytical model aerodynamic coefficients are calculated using datcom software [3]. flight test data of wulung uav has also been obtained to identify a linear model using grey-box method [4] that involves the analytical linear model. however, the flight dynamics model in the form of linear state-space cannot handle the changes in altitude and airspeed because the differential equations of flight dynamics use datcom aerodynamic coefficients which only can be applied for a specific altitude and airspeed. these studies led to a conclusion to develop a nonlinear wulung uav model in any condition of the flight altitude and airspeed for the first step into designing a nonlinear adaptive controller. consequently, a * corresponding author: tel: +62-8158000730 e-mail: fadjar.rahino@bppt.go.id f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 20 practical nonlinear flight dynamic model is required for a chosen adaptive control systems. subsequently, an adaptive control systems of an integrator back stepping, that have the advantage to handle the nonlinear model well, have been described by krstic [5]. nevertheless, a complicated analytical model derivation must be solved in designing this control systems. successively, command filtered back stepping (cfbs) has been proposed by farrell [6][7] that eliminated the requirement of analytical model derivation and simplified its control design. however, introducing the wulung uav model to this controller needs a nonlinear model in the form of strict-feedback systems [8][9] that separates the terms of the fixed-wing uav control variables as shown in figure 2 and expressed as the following model: 𝑥 = 𝑓 𝑥 + 𝑔 𝑥 𝑢 (1) where x and u are vectors of state and control variables respectively. this paper presents the development of a nonlinear flight dynamics model in any conditions of the flight altitude and airspeed by calculating aerodynamic coefficients as functions of altitude and airspeed. the program source of datcom software [3] are used as the basis to build analytical equations for aerodynamic coefficients using basic aerodynamics of lifting surfaces [10]. the advantage of this proposed nonlinear model is to eliminate the use of thirdparty software to obtain the aerodynamic coefficients, thus the geometry characteristic of the fixed-wing uav such as wing span and wing chord can be directly applied. later, we constructed 10 degrees of freedom (dof) of differential equations in the form of strictfeedback systems to represent a non-linear dynamic model [2][10][11] using the model of the proposed forces and moments that have input parameters of state variables including the altitude and the airspeed. simulations of bppt wulung uav in longitudinal and lateral dynamic have been conducted using this model, then their results have been matched with the actual flight test data to prove the compliance of this nonlinear model. ii. fixed-wing uav modeling figure 3 shows the movement components of fixed-wing uav consisting of the attitude 𝛯 = 𝜙 𝜃 𝜓 ⊺, velocity 𝑉 = 𝑈 𝑉 𝑊 ⊺, angular rate 𝛺 = 𝑝 𝑞 𝑟 ⊺, forces 𝐹 = 𝑋 𝑌 𝑍 ⊺, and moments 𝑀 = 𝐿𝜙 𝑀𝜃 𝑁𝜓 ⊺ in the vehicle coordinate frame 𝑥𝑣 , 𝑦𝑣 , 𝑧𝑣 . based on the newton's motion equations of the rigid body, the forces and moments [2][10] are defined as follows: 𝐹 = 𝑚𝑉 + 𝛺 × 𝑉 (2) 𝑀 = 𝐽𝛺 + 𝛺 × 𝐽𝛺 (3) where 𝑚 is the mass and j is the moment of inertia. figure 1. a prototype of bppt wulung uav figure 2. strict-feedback systems model f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 21 hence, the model of fixed-wing uav is then written in the following equation: 𝑉 = 𝐹 𝑚 − 𝛺 × 𝑉 (4) 𝛺 = 𝐽−1 𝑀 − 𝛺 × 𝐽𝛺 (5) the velocity is generally obtained from inertia sensors such as gps/ins that provides calculated velocity in an inertia coordinate frame. so these components can be converted into a vehicle coordinate frame as follows: 𝑉 = 𝑅𝑒 𝑣 𝑉𝑔𝑝𝑠 (6) where 𝑉𝑔𝑝𝑠 = 𝑉𝑛𝑜𝑟𝑡 𝑕 𝑉𝑒𝑎𝑠𝑡 𝑉𝑑𝑜𝑤𝑛 ⊺ is inertia velocity from gps/ins and r𝑒 𝑣 is direct cosine matrix (dcm) as defined as follows: 𝑅𝑒 𝑣 = 𝑅𝜙 𝑣 𝑅𝜃 𝑣 𝑅𝜓 𝑣 (7) 𝑅𝜙 𝑣 = 1 0 0 0 𝑐𝑜𝑠 𝜙 𝑠𝑖𝑛 𝜙 0 − 𝑠𝑖𝑛 𝜙 𝑐𝑜𝑠 𝜙 (8) 𝑅𝜃 𝑣 = 𝑐𝑜𝑠 𝜃 0 −𝑠𝑖𝑛 𝜃 0 1 0 𝑠𝑖𝑛 𝜃 0 𝑐𝑜𝑠 𝜃 (9) 𝑅𝜓 𝑣 = 𝑐𝑜𝑠 𝜓 𝑠𝑖𝑛 𝜓 0 −𝑠𝑖𝑛 𝜓 𝑐𝑜𝑠 𝜓 0 0 0 1 (10) beside angular rate of equation (5), the calculation of the euler angular rate ξ that has a link with the following angular rate is required: 𝛺 = 𝜙 0 0 + 𝑅𝜙 𝑣 0 𝜃 0 + 𝑅𝜙 𝑣 𝑅𝜃 𝑣 0 0 𝜓 (11) hence, the euler angular rate is written as follows: 𝛯 = 𝑅𝛺𝛺 (12) where, 𝑅𝛺 = 1 𝑠𝑖𝑛 𝜙 𝑡𝑎𝑛 𝜃 𝑐𝑜𝑠 𝜙 𝑡𝑎𝑛 𝜃 0 𝑐𝑜𝑠 𝜙 − 𝑠𝑖𝑛 𝜙 0 𝑠𝑖𝑛 𝜙 𝑐𝑜𝑠 𝜃 𝑐𝑜𝑠 𝜙 𝑐𝑜𝑠 𝜃 (13) in addition, the altitude rate can be written as follows: 𝑕 = −𝑉𝑑𝑜𝑤𝑛 = 𝑅𝑕 𝑉 (14) where, 𝑅𝑕 = 𝑠𝑖𝑛 𝜃 − 𝑠𝑖𝑛 𝜙 𝑐𝑜𝑠 𝜃 − 𝑐𝑜𝑠 𝜙 𝑐𝑜𝑠 𝜃 (15) therefore, a nonlinear fixed-wing uav model is obtained using equations (4), (5), (12), and (14) as 10-dof of differential equations. thereafter, the forces and the moments due to the influence of vehicle aerodynamics, propeller thrust, and gravity must be described as follows: 𝐹 = 𝐹𝑎 + 𝐹𝑝 + 𝐹𝑔 (16) 𝑀 = 𝑀𝑎 + 𝑀𝑝 (17) where 𝐹𝑎 and 𝑀𝑎 respectively are aerodynamic forces and moments, 𝐹𝑝 and 𝑀𝑝 respectively are propeller thrust forces and moments, and 𝐹𝑔 is gravity forces. a. aerodynamic forces and moments figure 4 shows three frames of coordinate, namely the vehicle coordinate frame 𝑥𝑣 , 𝑦𝑣 , 𝑧𝑣 , the stability coordinate frame 𝑥𝑠 , 𝑦𝑠, 𝑧𝑠 , and the wind coordinate frame 𝑥𝑤 , 𝑦𝑤 , 𝑧𝑤 . aerodynamic forces and moments, that occurs in fixed-wing uav, generally are caused by three kind of forces in the wind coordinate frame, i.e. lift force 𝐿, drag force 𝐷, and side force 𝑆. then the aerodynamic forces in vehicle coordinate frame is written as follows: 𝐹𝑎 = 𝑅𝑠 𝑣 𝑅𝑤 𝑠 −𝐷 𝑆 −𝐿 ⊺ (18) where, 𝑅𝑠 𝑣 = 𝑐𝑜𝑠 𝛼 0 −𝑠𝑖𝑛 𝛼 0 1 0 𝑠𝑖𝑛 𝛼 0 𝑐𝑜𝑠 𝛼 (19) 𝑅𝑤 𝑠 = 𝑐𝑜𝑠 𝛽 𝑠𝑖𝑛 𝛽 0 −𝑠𝑖𝑛 𝛽 𝑐𝑜𝑠 𝛽 0 0 0 1 (20) figure 3. vehicle coordinate frame components f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 22 whereas the aerodynamic moments in vehicle coordinate frame is also written as follows: 𝑀𝑎 = 𝐿𝜙𝑎 𝑀𝜃𝑎 𝑁𝜓𝑎 ⊺ (21) in order to form strict-feedback system, the forces and moments must be separated into two kind of forces and moments, i.e. affected by the control surfaces (elevator 𝛿𝑒 , aileron 𝛿𝑎 , and rudder 𝛿𝑟 ) or not affected. then equations (18) and (21) are rewritten as follows: 𝐹𝑎 = 𝐹𝑎𝑣 + 𝐶𝐹𝑎𝛿 𝛿𝑒 𝛿𝑎 𝛿𝑟 ⊺ (22) 𝑀𝑎 = 𝑀𝑎𝑣 + 𝐶𝑀𝑎𝛿 𝛿𝑒 𝛿𝑎 𝛿𝑟 ⊺ (23) hence, the lift, drag, and side forces in wind coordinate frame must also be separated as it is done to aerodynamic forces in vehicle coordinate frame, then equations (22) and (23) are broken down into the following equation: 𝐹𝑎𝑣 = 𝑅𝑠 𝑣 𝑅𝑤 𝑠 −𝐷𝑣 𝑆𝑣 −𝐿𝑣 ⊺ (24) 𝐶𝐹𝑎𝛿 = 𝑅𝑠 𝑣 𝑅𝑤 𝑠 −𝐶𝐷𝑒 0 −𝐶𝐷𝑟 0 0 𝐶𝑆𝑟 −𝐶𝐿𝑒 0 0 (25) 𝑀𝑎𝑣 = 𝐿𝜙𝑣 𝑀𝜃𝑣 𝑁𝜓𝑣 ⊺ (26) 𝐶𝑀𝑎𝛿 = 0 𝐶𝐿𝜙 𝑎 𝐶𝐿𝜙 𝑟 𝐶𝑀𝜃𝑒 0 0 0 𝐶𝑁𝜓 𝑎 𝐶𝑁𝜓 𝑟 (27) afterwards, the lift, drag, and side forces are calculated as follows: 𝐿𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝐿 0 + 𝐶𝐿𝛼 𝛼 (28) 𝐶𝐿𝑒 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝐿𝛿𝑒 (29) 𝑆𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝑆𝛽 𝛽 (30) 𝐶𝑆𝑟 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝑆𝛿𝑟 (31) 𝐷𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝐷 0 + 𝐶𝐷𝛼 𝛼 + 𝐶𝐷𝛽 𝛽 (32) 𝐶𝐷𝑒 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝐷𝛿𝑒 (33) 𝐶𝐷𝑟 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝐶𝐷𝛿𝑟 (34) in addition, the rolling, pitching, and yawing moments are calculated as follows: 𝐿𝜙𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝐿𝜙 𝛽 𝛽 (35) 𝐶𝐿𝜙 𝑎 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝐿𝜙 𝛿𝑎 (36) 𝐶𝐿𝜙 𝑟 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝐿𝜙 𝛿𝑟 (37) 𝑀𝜃𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝑀𝜙 0 + 𝐶𝑀𝜙 𝛼 𝛼 (38) 𝐶𝑀𝜃 𝑒 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝑀𝜃 𝛿𝑒 (39) 𝑁𝜓𝑣 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝑁𝜓 𝛽 𝛽 (40) 𝐶𝑁𝜓 𝑎 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝑁𝜓 𝛿𝑎 (41) 𝐶𝑁𝜓 𝑟 = 1 2 𝜌𝑉𝑎 2𝑆𝑤 𝑏𝑤 𝐶𝑁𝜓 𝛿𝑟 (42) where 𝜌 is the air density at altitude 𝑕, 𝑉𝑎 is the true airspeed, 𝑆𝑤 is the main wing surface area, and 𝑏𝑤 is the main wingspan. figure 4. aerodynamic and thrust forces f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 23 in linear system approach, all of those coefficients 𝐶∗ in equations (28) until (42) are assumed as constants. however, those coefficients are also depend on the true airspeed 𝑉𝑎 and the altitude 𝑕. hence, all of the coefficients are calculated into functions of 𝐶∗ 𝑉𝑎 , 𝑕 . note that ∗ denotes any character. subsequently, the aerodynamics coefficients are written as follows: 𝐶𝐿 0 = 𝐶𝐿𝑤𝛼 𝜂𝑤 − 𝛼𝑤0 + 𝐶𝐿𝑕𝛼 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 𝑑 𝑑𝛼 𝛼𝑤0 − 𝜂𝑤 − 𝛼𝑕0 + 𝜂𝑕 (43) 𝐶𝐿𝛼 = 𝐶𝐿𝑤𝛼 + 𝐶𝐿𝑕𝛼 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 1 − 𝑑 𝑑𝛼 (44) 𝐶𝐿𝛿𝑒 = 𝐶𝐿𝑕𝛿𝑒 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 (45) 𝐶𝑆𝛽 = 𝐶𝑆𝑣𝛽 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (46) 𝐶𝑆𝛿𝑟 = 𝐶𝑆𝑣𝛿𝑟 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (47) 𝐶𝐷 0 = 𝐶𝐷𝑤𝑝 + 𝐶𝐷𝑕𝑝 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 + 𝐶𝐷𝑣𝑝 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 + 𝐶𝐿𝑤𝛼 𝜂𝑤 − 𝛼𝑤0 2 𝜋𝐴𝑤 𝑒𝑤 + 𝐶𝐿𝑕𝛼 𝛼𝑕 0 − 𝛼𝑕0 2 𝜋𝐴𝑕 𝑒𝑕 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 𝐶𝐷 0 + 2𝐶𝐿 𝑕𝛼 2 𝛼𝑕 0 −𝛼𝑕 0 𝜋𝐴𝑕 𝑒𝑕 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 𝜂𝑕 (48) 𝐶𝐷𝛼 = 2𝐶𝐿 𝑤 𝛼 2 α+𝜂𝑤 −𝛼𝑤 0 𝜋𝐴𝑤 𝑒𝑤 𝐶𝐷𝛼 = 2𝐶𝐿𝑕𝛼 2 𝛼𝑕 𝛼 − 𝛼𝑕0 𝜋𝐴𝑕 𝑒𝑕 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 1 − 𝑑 𝑑𝛼 (49) 𝐶𝐷𝛽 = 2𝐶𝑆𝑣𝛽 2 𝛽−𝛽𝑣0 𝜋𝐴𝑣𝑒𝑣 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (50) 𝐶𝐷𝛿𝑒 = 2𝐶𝐿 𝑕𝛼 𝛼𝑕 𝛼 −𝛼𝑕 0 𝜋𝐴𝑕 𝑒𝑕 𝐶𝐿𝑕𝛿𝑒 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 (51) 𝐶𝐷𝛿𝑟 = 2𝐶𝑆𝑣𝛽 𝛽−𝛽𝑣0 𝜋𝐴𝑣𝑒𝑣 𝐶𝑆𝑣𝛿𝑟 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (52) 𝐶𝐿𝜙 𝛽 = 𝐶𝐿𝜙 𝑤 𝛽 + 𝐶𝐿𝜙 𝑕𝛽 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 𝑏𝑕 𝑏𝑤 𝐶 𝐿𝜙 𝛽 + 𝐶𝐿𝜙 𝑣𝛽 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 𝑏𝑣 𝑏𝑤 (53) 𝐶𝐿𝜙 𝛿𝛼 = 𝐶𝐿𝜙 𝑤 𝛿𝛼 (54) 𝐶𝐿𝜙 𝛿𝑟 = 𝐶𝑆𝑣𝛿𝑟 𝑧mac v 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 𝑏𝑤 (55) 𝐶𝑀𝜙 0 = 𝐶𝑀𝜙 𝑤 ac + 𝐶𝑀𝜙 𝑓0 +𝐶𝐿𝑤𝛼 𝜂𝑤 − 𝛼𝑤0 +𝐶𝐿𝑤𝛼 𝜂𝑤 − 𝛼𝑤0 𝑥ac 𝑤𝑓 −𝑥cg 𝑐 −𝐶𝐿𝑕𝛼 𝑥cg −𝑥ac 𝑕 𝑐 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 𝑑 𝑑𝛼 𝛼𝑤0 − 𝜂𝑤 − 𝛼𝑕0 (56) 𝐶𝑀𝜙 𝛼 = 𝐶𝐿𝑤𝛼 𝑥ac 𝑤𝑓 −𝑥cg 𝑐 𝐶𝑀𝜙 𝛼 − 𝐶𝐿𝑕𝛼 𝑥cg −𝑥ac 𝑕 𝑐 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 1 − 𝑑 𝑑𝛼 (57) 𝐶𝑀𝜃 𝛿𝑒 = −𝐶𝐿𝑕𝛿𝑒 𝑥cg −𝑥ac 𝑕 𝑐 𝑞𝑕 𝑞∞ 𝑆𝑕 𝑆𝑤 (58) 𝐶𝑁𝜓 𝛽 = −𝐶𝑆𝑣𝛽 𝑥cg −𝑥ac 𝑣 𝑐 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (59) 𝐶𝑁𝜓 𝛿𝑎 = 𝐶𝑁𝜓 𝑤 𝛿𝑎 (60) 𝐶𝑁𝜓 𝛿𝑟 = −𝐶𝑆𝑣𝛿𝑟 𝑥cg −𝑥ac 𝑣 𝑐 𝑞𝑕 𝑞∞ 𝑆𝑣 𝑆𝑤 (61) where 𝜂𝑤 and 𝜂𝑕 respectively are wing and horizontal tail plane (htp) rigging angles, 𝐴𝑤 , 𝐴𝑕 , 𝐴𝑣 respectively are wing, htp, and vertical tail plane (vtp) aspect ratios, 𝛼𝑤0 , 𝛼𝑕0 , 𝛽𝑣0 respectively are wing, htp, and vtp angles of attack at zero-lift, 𝑞𝑕 𝑞∞ is htp dynamic pressure ratio, 𝑑 𝑑𝛼 is downwash gradient, 𝑒𝑤 , 𝑒𝑕 , 𝑒𝑣 respectively are wing, htp, and vtp oswald coefficient, 𝑆𝑕 and 𝑆𝑣 respectively are htp and vtp surface area, 𝑏𝑕 and 𝑏𝑣 respectively are htp and vtp span. 𝛼𝑕 𝛼 is htp angle of attack due to the vehicle angle of attack that is formulated as follows: 𝛼𝑕 𝛼 = 𝛼 + 𝜂𝑕 − 𝜂𝑤 − 𝑑 𝑑𝛼 α − 𝛼𝑤0 (62) 𝑐 is wing mean aerodynamic chord (mac) length, 𝑥cg is center position of gravity, 𝑥ac 𝑤𝑓 , 𝑥ac 𝑕 , 𝑥ac 𝑣 respectively are wing-fuselage, htp, and vtp aerodynamic center (a.c.) positions, and 𝑧mac v is vtp mac normal position. 𝐶𝐷𝑤𝑝 , 𝐶𝐷𝑕𝑝 , 𝐶𝐷𝑣𝑝 respectively are wing, htp, and vtp parasite drag. 𝐶𝑀𝜙 𝑤 ac and 𝐶𝑀𝜙 𝑓0 respectively are wing and fuselage rolling moment coefficient at 𝛼 = 0. 𝐶𝑁𝜓 𝑤 𝛿𝑎 is wing yawing moment coefficient due to aileron. furthermore, the wing, htp, and vtp lift coefficients respectively are defined as follows [10]: f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 24 𝐶𝐿𝑤𝛼 = 2𝜋𝐴𝑤 2+ 𝐴𝑤 1− 𝑉𝑎 𝑎 2 𝑐𝑙𝑤 𝛼 0 2𝜋 2 1+ tan 𝛬 1 2𝑤 2 1− 𝑉𝑎 𝑎 2 +4 (63) 𝐶𝐿𝑕𝛼 = 2𝜋𝐴𝑕 2+ 𝐴𝑕 1− 𝑉𝑎 𝑎 2 𝑐𝑙𝑕𝛼 0 2𝜋 2 1+ tan 𝛬 1 2𝑕 2 1− 𝑉𝑎 𝑎 2 +4 (64) 𝐶𝑆𝑣𝛽 = − 2𝜋𝐴𝑣 2+ 𝐴𝑣 1− 𝑉𝑎 𝑎 2 𝑐𝑙𝑣𝛼 0 2𝜋 2 1+ tan 𝛬 1 2𝑣 2 1− 𝑉𝑎 𝑎 2 +4 (65) where 𝑎 is the speed of sound at altitude 𝑕, 𝑐𝑙 𝑤𝛼 0 , 𝑐𝑙 𝑕𝛼 0 , 𝑐𝑙 𝑣𝛼 0 respectively are wing, htp, and vtp airfoil lift coefficients, 𝛬1 2𝑤 , 𝛬1 2𝑕 , 𝛬1 2𝑣 respectively are wing, htp, and vtp half sweep angles. in addition, the elevator, aileron, and rudder coefficients respectively are defined as follows [10]: 𝐶𝐿𝑕𝛿𝑒 = 𝑐𝑙𝑕𝛿𝑒0 1− 𝑉𝑎 𝑎 2 (66) 𝐶𝐿𝜙𝑤 𝛿𝑎 = 𝑐𝑙𝜙 𝑕 𝛿𝑎 0 1− 𝑉𝑎 𝑎 2 (67) 𝐶𝑆𝑣𝛿𝑟 = 𝑐𝑙𝑣𝛿𝑟0 1− 𝑉𝑎 𝑎 2 (68) where 𝑐𝑙 𝑕𝛿𝑒0 , 𝑐𝑙 𝜙𝑕 𝛿𝑎 0 , 𝑐𝑙 𝑣𝛿𝑟0 respectively are elevator, aileron, and rudder airfoil lift coefficients which are not affected by altitude and airspeed. the wing, htp, and vtp rolling moment are defined as follows [10]: 𝐶𝐿𝜙 𝑤 𝛽 = −𝐶𝐿𝑤𝛼 𝜂𝑤 − 𝛼𝑤0 𝑦mac 𝑤 𝑏𝑤 𝐶𝐿 sin 2𝛬𝑤le − 𝛤𝑤 𝐶𝐿𝑤𝛼 𝑦mac 𝑤 𝑏𝑤 (69) 𝐶𝐿𝜙 𝑕𝛽 = −𝐶𝐿𝑕𝛼 𝜂𝑕 − 𝛼𝑕0 𝑦mac 𝑕 𝑏𝑕 sin 2𝛬𝑕le − 𝛤𝑕 𝐶𝐿𝑕𝛼 𝑦mac 𝑕 𝑏𝑕 (70) 𝐶𝐿𝜙 𝑣𝛽 = 𝐶𝑆𝑣𝛽 𝑧mac 𝑣 𝑏𝑣 (71) where 𝑦mac 𝑤 and 𝑦mac 𝑕 respectively are wing and htp mac side positions, 𝛤𝑤 and 𝛤𝑕 respectively are wing and htp dihedral angles, 𝛬𝑤le and 𝛬𝑕le respectively are wing and htp leading-edge sweep angles. b. propeller thrust forces and moments the relation between the engine power and the thrust generally use the power and thrust coefficients [12][11] that are defined respectively as follows: 𝐶𝑝 𝐽 = 𝑃 𝜌𝑛prop 3 𝐷prop 5 (72) 𝐶𝑡 𝐽 = 𝑇 𝜌𝑛prop 2 𝐷prop 4 (73) where 𝑃 is engine power, 𝐷prop is propeller diameter, 𝑛prop is propeller rotation per second, and 𝐽 is rate of advance that is also defined as follows [12][11]: 𝐽 = 𝑉𝑎 𝑛prop 𝐷prop (74) figure 5a and figure 5b show the power and thrust coefficient for wulung uav model that can be represented as polynomial equations as follow: 𝐶𝑝 𝐽 = 𝑎𝐶𝑝 1 𝐽3 + 𝑎𝐶𝑝 2 𝐽2 + 𝑎𝐶𝑝 3 +𝑎𝐶𝑝 4 (75) 𝐶𝑡 𝐽 = 𝑎𝐶𝑡1 𝐽3 + 𝑎𝐶𝑡2 𝐽2 + 𝑎𝐶𝑡3 𝐽 +𝑎𝐶𝑡4 (76) then, the relation between the throttle and engine power is proposed as follows: 𝑃 𝛿𝑡 = 𝑎𝑃1 𝛿𝑡 3 + 𝑎𝑃2 𝛿𝑡 2 + 𝑎𝑃3 𝛿𝑡 + 𝑎𝑃4 (77) figure 5c shows the relation of equation (77) for wulung uav. therefore, a solution for the following equation must be performed to obtain propeller rotation 𝑛. 𝑃 𝛿𝑡 = 𝑎𝑛1 𝑛 3 + 𝑎𝑛2 𝑛 2 + 𝑎𝑛3 𝑛 + 𝑎𝑛4 (78) where 𝑎𝑛1 = −𝑎𝐶𝑝 4 𝜌𝐷𝑝𝑟𝑜𝑝 3 , 𝑎𝑛2 = −𝑎𝐶𝑝 3 𝜌𝑉𝑎 𝐷𝑝𝑟𝑜𝑝 2 , 𝑎𝑛3 = −𝑎𝐶𝑝 2 𝜌𝑉𝑎 2𝐷𝑝𝑟𝑜𝑝 , and 𝑎𝑛4 = −𝑎𝐶𝑝 1 𝜌𝑉𝑎 3. hence, the propeller thrust can be calculated as follows: 𝑇 = 𝐶𝑡 𝑉𝑎 𝑛𝑝𝑟𝑜𝑝 𝐷𝑝𝑟𝑜𝑝 𝜌𝑛2𝐷𝑝𝑟𝑜𝑝 4 (79) next, the thrust as shown in figure 5d is linearized as follows: 𝑇 = 𝑇0 + 𝐶𝑇𝛿𝑡 𝛿𝑡 (80) f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 25 similar to aerodynamic coefficients calculation, 𝑇0 and 𝐶𝑇𝛿𝑡 are depend on the true airspeed 𝑉𝑎 and the altitude 𝑕. hence, the forces and moments caused by the thrust in vehicle coordinate frame is written as follows: 𝐹𝑝 = 𝐹𝑝𝑣 + 𝐶𝐹𝑝 𝛿 𝛿𝑡 (81) 𝑀𝑝 = 𝑀𝑝𝑣 + 𝐶𝑀𝑝 𝛿 𝛿𝑡 (82) similar to aerodynamic forces and moment, the equations (81) and (82) is then broken down as follows: 𝐹𝑝𝑣 = 𝑇0 𝑐𝑜𝑠 𝜏 0 −𝑇0 𝑠𝑖𝑛 𝜏 ⊺ (83) 𝐶𝐹𝑝 𝛿 = 𝐶𝑇𝛿𝑡 𝑐𝑜𝑠 𝜏 0 −𝐶𝑇𝛿𝑡 𝑠𝑖𝑛 𝜏 ⊺ (84) 𝑀𝑝𝑣 = 𝐹𝑝𝑣 × 𝑃𝑝𝑟𝑜𝑝 (85) 𝐶𝑀𝑝 𝛿 = 𝐶𝐹𝑝 𝛿 × 𝑃𝑝𝑟𝑜𝑝 (86) where 𝑃𝑝𝑟𝑜𝑝 = 𝑥𝑝𝑟𝑜𝑝 0 𝑧𝑝𝑟𝑜𝑝 ⊺ is the position of the propeller in vehicle coordinate frame and 𝜏 is propeller rigging angle. c. gravitational forces figure 6b shows the forces of gravitation in inertia coordinate frame, while figure 6a shows the forces in vehicle coordinate frame. thus, we write the gravitational forces in vehicle coordinate frame as follows: (a) (b) (c) (d) figure 5. wulung propeller model: (a) power coefficient; (b) thrust coefficient; (c) power vs throttle; (d) thrust vs throttle (a) (b) figure 6. gravitational forces: (a) vehicle frame; (b) inertia frame f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 26 𝐹𝑔 = 𝑅𝑒 𝑣 0 0 𝑚𝑔 ⊺ = 𝑚𝑔 −𝑠𝑖𝑛 𝜃 𝑐𝑜𝑠 𝜃 𝑠𝑖𝑛 𝜙 𝑐𝑜𝑠 𝜃 𝑐𝑜𝑠 𝜙 ⊺ (87) where 𝑚 is mass of the fixed-wing uav and 𝑔 is gravitational constant. d. nonlinear flight dynamic model the control input 𝑢 and the state variable 𝑥 are defined as follows: 𝑢 = 𝛿𝑒 𝛿𝑎 𝛿𝑟 𝛿𝑡 ⊺ (88) 𝑥 = 𝑉⊺ 𝛺⊺ 𝛯⊺ 𝑕 ⊺ (89) hence, from equations (12), (14), (24)-(27), (83)-(87), the nonlinear functions f x and g x of equation (1) can be written as follows: 𝑓 𝑥 = 𝐹𝑎 𝑣 +𝐹𝑝𝑣 +𝐹𝑔 𝑚 − 𝛺 × 𝑉 𝐽−1 𝑀𝑎𝑣 + 𝑀𝑝𝑣 − 𝛺 × 𝐽𝛺 𝑅𝛺𝛺 𝑅𝑕 𝑉 (90) 𝑔 𝑥 = 𝐶𝐹𝑎 𝛿 𝑚 𝐶𝐹𝑝𝛿 𝑚 𝐽−1𝐶𝑀𝑎 𝛿 𝐽−1𝐶𝑀𝑝 𝛿 04×3 04×1 (91 iii. flight dynamics responses wulung uav profiles in table 1 are used as model parameters for simulating the responses of the flight dynamics. two scenarios of disturbance are done by providing doublet angles of elevator and aileron to show the longitudinal and lateral dynamics responses of wulung uav. before performing simulation, the steady state of flight must be found in the condition that the uav cruises without changing the altitude by trimming the elevator and throttle. therefore, if the altitude, throttle, and elevator are respectively set to 𝑕 = 3000 feet, 𝛿𝑡 = 67%, and 𝛿𝑒 = −3.3 deg, the steady state condition of wulung uav model will be occurred at pitching angle 𝜃 = 1.87 deg, axial velocity 𝑈 = 58.75 knots, and normal velocity 𝑊 = 1.21 knots. wulung uav model is then simulated using 10-dof differential equation (90) and (91). after the calculation, the velocity, angular rate, attitude, and altitude of wulung uav are obtained for each simulation scenario. a. longitudinal dynamics responses in this simulation scenario, the uav moves westward with the throttle, altitude, velocity, and table 1. wulung uav profiles parameter unit mass, 𝑚 120 (kg) wing area, 𝑆𝑤 3.9718 (m 2 ) wingspan, 𝑏𝑤 6.355 (m) htp area, 𝑆𝑕 0.819 (m 2 ) htp span, 𝑏𝑕 1.95 (m) vtp area, 𝑆𝑣 0.519 (m 2 ) vtp span, 𝑏𝑣 0.845 (m) wing rigging angle, 𝜂𝑤 6 htp rigging angle, 𝜂𝑕 -3 wing dihedral, 𝛤𝑤 3 c.g. position, 𝑥cg -1.576 (m) wing-fuselage a.c. position, 𝑥ac 𝑤𝑓 -1.497 (m) htp a.c. position, 𝑥ac 𝑕 -4.136 (m) vtp a.c. position, 𝑥ac 𝑣 -3.97 (m) wing mac side position, 𝑦mac 𝑤 1.589 (m) htp mac side position, 𝑦mac 𝑕 0.488 (m) vtp mac normal position, 𝑧mac v 0.294 (m) 𝐽xx 79.045 (kgm 2 ) 𝐽yy 103.473 (kgm 2 ) 𝐽𝑧𝑧 159.541 (kgm 2 ) 𝐽𝑥𝑧 19.131 (kgm 2 ) engine max power 20 (hp) propeller diameter, 𝐷𝑝𝑟𝑜𝑝 32 (inch) f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 27 attitude as well as steady state condition. therefore, the elevator angle is set to 𝛿𝑒 = 6.7 deg at time 𝑡 = 10 sec, 𝛿𝑒 = −13.3 deg at time 𝑡 = 10.5 sec, and 𝛿𝑒 = −3.3 deg at time 𝑡 = 11 sec as shown in figure 7a. figure 7a also shows the responses of the pitch and attack angles. once elevator trailing edge down (positive), decreasing the both angles of pitch and attack, and after elevator trailing edge up (negative), increasing the both angles of pitch and attack. thereafter, the angle of attack immediately return to normal angle less than 3 second, but the pitching angle takes time of damped oscillation to back to steady states. in addition, figure 7b shows the responses of the velocity and altitude. it seems clear that the wulung uav suffered phugoid motion with 2 minutes of damping. this simulation denotes to a conclusion that the longitudinal dynamics characteristic of wulung uav is stable without a hard control effort that indicated by the convergence of states. b. lateral dynamics responses similar to longitudinal simulation scenario, the fixed-wing uav moves westward in steady state condition. therefore, the aileron angle is set to 𝛿𝑎 = 5 deg at time 𝑡 = 10 sec, 𝛿𝑎 = −5 deg at time 𝑡 = 10.5 sec, and aileron angle back to zero again at time 𝑡 = 11 sec as shown in figure 8a. figure 8a also shows the responses of the roll, pitch, and sideslip angles. once left aileron trailing edge down (positive), increasing bank angle (roll to right) at high roll rate but decreasing the sideslip angle slightly, and after aileron trailing edge up (negative), still increasing the bank angle at weakened roll rate and also increasing the sideslip angle. thereafter, the sideslip angle takes time about 2 minutes of damped oscillation to back to the steady state. in contrast, the bank angle decreases to minimum negative angle (roll to left) about 30 seconds and then slowly rises gradually towards steady state in a long time. the aileron doublet disturbance is also reacting on the pitching angle that oscillates for about 3 minutes damping. figure 8b shows the responses of the heading and altitude. it seems clear that wulung uav bank angle did not immediately return to the steady state in a long time after aileron doublet disturbance, thus causing the vehicle has a tendency to turn. this (a) (b) figure 7. wulung longitudinal dynamics responses: (a) elevator doublet and the responses; (b) the velocity and altitude (a) (b) figure 8. wulung lateral dynamics responses: (a) aileron doublet and the responses; (b) the heading and altitude f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 28 simulation denotes to a conclusion that the lateral dynamics characteristic of wulung uav is stable but still need a lateral control to restore the bank angle to the steady state immediately. wulung uav also suffered phugoid motion for about 2 minutes that is indicated by pitching angle damped oscillation. iv. simulation and flight test a flight test of wulung uav has been conducted and the results are compared with model simulation. the elevator doublet of flight test as shown in figure 9b is mimicked into model simulation of longitudinal dynamic as shown in figure 9a. the difference of physical angles may be caused by initial steady state and the windy conditions when the flight test conducted. further, both results are normalized so the steady state is same and compared as shown in figure 9c and figure 9d. figure 9c shows that both responses of the pitching angle and the angle of attack between model simulation and flight test approached similarity. while figure 9d shows that pitch rate responses are nearly similar between model simulation and the flight test. hence, these results demonstrate conformity of model simulation with the actual flight of longitudinal dynamic. the model is better than the system identification method using grey-box [1] because it is compliance with any conditions of altitude and airspeed. figure 10 shows the response of normalized altitude and velocity so the initial steady state is same. the difference between the simulation and the flight test may be caused by the windy conditions when the flight test conducted. (a) (b) (c) (d) figure 9. model simulation and flight test results of longitudinal dynamics responses; (a) model simulation results; (b) flight test results; (c) pitching and attack angles responses; (d) pitch rate responses f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 29 v. conclusion the longitudinal and lateral dynamics responses of wulung uav are good enough concerning to the outcome of model simulations that show the stability of flying without the hard control effort. our proposed model is also compliance with flight test results of wulung uav. furthermore, our nonlinear model of the fixed-wing uav has the advantage to calculate flight dynamics for all conditions of altitude and airspeed that is important to build a controller that adapt to the uav altitude and airspeed. as future works, this model will be used for an adaptive nonlinear controller using command filtered backstepping method. this model also will be employed for building the hardware in the loop simulation (hils) systems that very useful for testing the hardware controller module before being used in the field. acknowledgement the authors express thanks to uav team of bppt technology center for defense and security industry, for the support and the providing of required facilities and conducive conditions for this research. references [1] f. r. triputra, et al., "longitudinal dynamic system modeling of a fixed-wing uav towards autonomous flight control system development: a case study of bppt wulung uav platform," in proc. ieeeicset, sep. 2012. [2] m. v. cook, flight dynamics principles: a linear systems approach to aircraft stability and control. 2nd ed., massachusetts: elseivier, 2007. [3] r. d. finck, usaf stability and control datcom. mcdonnell douglas corp, wright-patterson afb, ohio,final report afwal-tr-83-3048, revised, april, 1978. [4] l. ljung, system identification toolbox users’s guide for use with matlab, the math works inc., 1995. [5] m. krstic, et al., nonlinear and adaptive control design. new york: john wiley & sons, inc., 1995, pp. 87-121. [6] j. a. farrell and m. m. polycarpou, adaptive approximation based control. new jersey: john wiley & sons, inc., 2006. [7] j. a. farrell, et al., "command filtered backstepping", ieee transaction on automatic control, 54(6), pp. 1391-1395, june, 2009. [8] o. harkegard and s. t. glad, flight control design using backstepping. linkoping university, sweden, rep. no. lith-isy-r2323, 2001. [9] t. espinoza, et al., "backstepping sliding mode controllers applied to a fixed-wing uav," in proc. ieee-cerma, may, 2013. [10] d. k. schmidt, modern flight dynamics. int. ed., new york: mcgraw-hill, 2012, pp. 156-322. figure 10. altitude and velocity responses f.r. triputra et al. / j. mechatron. electr. power veh. technol 06 (2015) 19–30 30 [11] r. w. beard and t. w. mclain, small unmanned aircraft: theory and practice. united kingdom: princeton university press, 2012, pp. 8-38. [12] a. fillipone, "propeller characteristics", 2.4.9, aerospace engineering desk reference. first ed., san diego, ca: elsevier inc., 2009. j. mechatron. electr. power veh. technol 06 (2015) 9–18 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.9-18 a modified gain scheduling controller by considering the sparseness property of uav quadrotors m. qodar abdurrohman a, *, reka inovan a , ahmad ataka a , hilton tnunay a , ardhimas wimbo a , iswanto a , adha cahyadi a , yoshio yamamoto b a department of electrical engineering and information technology, gadjah mada university jalan grafika 2, yogyakarta 55281 b department of precision engineering, school of engineering, tokai university 1117 hiratsuka-shi, kanagawa-ken, japan received 12 november 2014; received in revised form 17 march 2015; accepted 17 march 2015 published online 30 july 2015 abstract this work presented the gain scheduling based lqr for quadrotor systems. from the original nonlinear model, the system is always controllable and observable in various equilibrium points. moreover, the linearized systems have a unique property that is known as sparse system. hence, in order to implement the most efficient state feedback controller, post-filter and pre-filter were introduced to transform the state coordinate to decrease coupling between states. finally, the gain scheduling systems using these facts was proposed. the system behavior was tested using the proposed controller. the numerical studies showed the effectiveness of the controller to achieve desired altitude, attitude, and its ability during the disturbance. keywords: quadcopters; sparse system; linearization; gain scheduling; pole-placement. i. introduction quadcopter is one of unmanned aerial vehicles that become popular and having much attention recently, especially from the researchers and hobbyist in aeromodelling. several factors that contribute to its popularity are its reliability in maneuvering, its ability to be flown indoors, and easier to model and control [1], [2]. one of the most important problem on the quadcopter stems comes from the fact that quadcopter is essentially not a stable system, both in stabilization and trajectory following. therefore, special considerations are needed in designing the control system for stabilizing or maneuvering. existing control theories in controlling quadcopter are widely varied. the most commonly used is the conventional pid control [3], mainly due to its simple structure that is easy enough to be designed and implemented in varied systems, including quadcopter [1]. the drawback of pid controller is the gain that set for optimum in some specific conditions. in order to get the better results, the controller has to be adaptive so that it can adjust the controller gain to adapt to the position and attitude change of the quadrotor. many people have tried to design this adaptive control such as gaikwad [4] with auto-tuning pid loop shaping and liu [5] who design self-adaptive pid based on the least-square method. another approach is proposed to control a quadcopter using pd controller equipped with active force control to reject uncertainty disturbance by estimating disturbance torque value [6]. one of the challenges in designing controller for quadrotor is that the system is non-linear, a very common to linearize first. the basic limitation of the controller design via standard linearization is the fact that the control is guaranteed to work only in the neighborhood of a single equilibrium point. gain scheduling is a technique to design a controller of non-linear system by linearization the system at several equilibrium points, designing the controller at each point, and implementing the family of linear controllers as a single controller with varying gain or parameter [7]. this paper also present the linearization of the simplified model of quadrotor based on [1] using * corresponding author.tel: +6281804092541 e-mail: m.qodar.a@mail.ugm.ac.id m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 10 the gain scheduling linearization at some equilibrium points. then, the controllability and observability of the system for various equilibrium points is proposed. after that, using the linearized state equations, the state feedback controllers is obtained and applied to control the altitude and attitude of the quadrotor non-linear model. for implementation purpose, a controller that focused on improvement of pole placement method is proposed by restructuring the state variable of linearized quadcopter dynamics to its jordan form to emphasize the sparseness of the dynamics. ii. system overview a. notation explanation this section consists of explanation on the derivation of state-space equations of quadcopter system. the linearization is performed to formulate the transfer function of the quadcopter plant. the model is shown in figure 1. 12 states are used for this state-space model. the position in world frame is denoted as = [x y z], while the roll, pitch, yaw angles denoted as  = []. the velocity due to x-axis, y-axis, zaxis denoted as  = [ẋ ẏ ż], and the angular velocity due to x-axis, y-axis, z-axis denoted as  = [ṗ q̇ ṙ]. the state variable and its system input is set as x = [        ], and u = [        ]. hence it was set that x = [ x1, . . . , x12 ] t and u = [ u1, . . . , u4 ] t b. translational and rotational analysis based on newton’s second law of translational motion, this equation is obtained: 𝐹 = 𝑚𝑣 + (𝜔 × 𝑚𝑣)  where 4 and v = 3. from figure 1, the forces which is worked on the quadcopter is obtained as: 𝐹 = 𝐹𝑔 − 𝐹thrust  𝐹 = 0 0 𝑚𝑔 𝑇 +𝑤 𝑅𝐵 0 0 𝑇 𝑇  therefore, equation 3 can be expressed as: 𝑣 = 1 𝑚 0 0 1 − 𝑅 0 0 𝑇 𝐵 𝑊 − 𝑝 𝑞 𝑟 × 𝑥 𝑦 𝑧  where m is the mass of quadcopter, t is vertical thrust of quadcopter against gravity and w rb is the rotation matrix from body-frame to worldframe or inertial-frame, where: 𝑊 𝑅𝐵 = 𝑐𝜃 𝑐𝜓 𝑠𝜙 𝑠𝜃 𝑐𝜓 − 𝑐𝜙 𝑠𝜓 𝑐𝜙 𝑠𝜃 𝑐𝜓 + 𝑠𝜙 𝑠𝜓 𝑐𝜃 𝑠𝜓 𝑠𝜙 𝑠𝜃 𝑠𝜓 + 𝑐𝜙 𝑐𝜓 𝑐𝜙 𝑠𝜃 𝑠𝜓 − 𝑠𝜙 𝑐𝜓 𝑠𝜃 𝑠𝜙 𝑐𝜃 𝑐𝜙 𝑐𝜃  𝑣 = 1 𝑚 −𝑇(𝑐𝜙 𝑠𝜃 𝑐𝜓 + 𝑠𝜙 𝑠𝜓 ) −𝑇(𝑐𝜙 𝑠𝜃 𝑠𝜓 − 𝑠𝜙 𝑐𝜓 ) 𝑚𝑔 − 𝑇𝑐𝜙 𝑐𝜃 − 𝑅 𝑞 𝑧 − 𝑟 𝑦 𝑟 𝑥 − 𝑝 𝑧 𝑝 𝑦 − 𝑞 𝑥 𝐵 𝑊  assumed that ṗ, q̇, ṙ, ẋ, ẏ, ż equal to zero, then: 𝑥 = − 1 𝑚 𝑇(𝑐𝜙 𝑠𝜃 𝑐𝜓 + 𝑠𝜙 𝑠𝜓 )  𝑦 = − 1 𝑚 𝑇(𝑐𝜙 𝑠𝜃 𝑠𝜓 − 𝑠𝜙 𝑐𝜓 )  𝑧 = 𝑔 − 1 𝑚 𝑇𝑐𝜙 𝑐𝜃  using rigid body rotational law, 𝛤 is: 𝛤 = 𝐼𝜔 + (𝜔 × 𝐼𝜔)   where, i is moment of inertia of quadcopter as: 𝐼 = 𝐼𝑥 0 0 0 𝐼𝑦 0 0 0 𝐼𝑧   then, equation 10 can be written as: 𝐼𝜔 = 𝜏𝑥 𝜏𝑦 𝜏𝑧 − 𝑝 𝑞 𝑟 × 𝐼𝑥 𝑝 𝐼𝑦 𝑞 𝐼𝑧𝑟  and 𝜏𝑥 = 𝑑𝑏 𝜔4 2 − 𝜔2 2  𝜏𝑦 = 𝑑𝑏 𝜔1 2 − 𝜔3 2  𝜏𝑧 = 𝑘 𝜔1 2 − 𝜔2 2 + 𝜔3 2−𝜔4 2  𝑇 = 𝑏(𝜔1 2 + 𝜔2 2 + 𝜔3 2 +𝜔4 2 )  thus, these equations for angular acceleration of quadcopter is: 𝑝 = 𝑑𝑏 𝐼𝑥 (𝜔4 2 − 𝜔2 2 ) − 𝐼𝑧 −𝐼𝑦 𝐼𝑥 𝑞 𝑟   𝑞 = 𝑑𝑏 𝐼𝑦 (𝜔1 2 − 𝜔3 2 ) − 𝐼𝑥 −𝐼𝑧 𝐼𝑦 𝑝 𝑟   𝑟 = 𝑘 𝐼𝑧 (𝜔1 2 − 𝜔2 2 + 𝜔3 2−𝜔4 2 ) − 𝐼𝑦 −𝐼𝑥 𝐼𝑧 𝑝 𝑞   figure 1. quadcopter axis m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 11 the roll, pitch and yaw (rpy) rates which is a function of angular velocity were derived using inverted jacobian matrix, denoted as: 𝑊−1 = 1 𝑐𝜃 𝑐𝜃 𝑠𝜙 𝑠𝜃 𝑐𝜙 𝑠𝜃 0 𝑐𝜙 𝑐𝜃 −𝑠𝜙 𝑐𝜃 0 𝑠𝜙 𝑐𝜙  and the relation between rpy rates and angular velocity is expressed by matrix: 𝜙 𝜃 𝜓 = 𝑊−1 𝑝 𝑞 𝑟  so, the roll, pitch, yaw rates: 𝜙 = 𝑝 + 𝑠𝜙 𝑡𝜃 𝑞 + 𝑐𝜙 𝑡𝜃 𝑟 = 0  𝜃 = 𝑐𝜙 𝑞 + 𝑠𝜙 𝑟 = 0  ψ = sϕ cθ q + cϕ cθ r = 0   c. linearization the non-linear model of quadrotor will be linearized at the equilibrium points to make the system more amenable. in order to do the linearization, it is required to find the equilibrium point of the system, hence 0 = 𝑓(𝜒 𝛼, 𝛽, 𝛾, 𝛿 ). it is trivial that part of equibrium points are as follow: 𝑥1 = 𝑥 = 𝑥7 = 0  𝑥2 = 𝑥 = 𝑥8 = 0  𝑥3 = 𝑥 = 𝑥9 = 0  𝑥 4 = 𝜙 = 𝑥10 + 𝑠𝑥4 𝑡𝑥5 𝑥11 + 𝑐𝑥4 𝑡𝑥5 𝑥12 = 0  𝑥 5 = 𝜃 = 𝑐𝑥4 𝑥11 + 𝑠𝑥4 𝑥12 = 0  𝑥 6 = 𝜓 = 𝑠𝑥 4 𝑐𝑥 5 𝑥11 + 𝑐𝑥 4 𝑐𝑥 5 𝑥12 = 0  𝑥 7 = 𝑥 = − 1 𝑚 𝑇(𝑐𝑥4 𝑠𝑥5 𝑐𝑥6 + 𝑠𝑥4 𝑠𝑥6 ) = 0  𝑥 8 = 𝑦 = − 1 𝑚 𝑇(𝑐𝑥4 𝑠𝑥5 𝑠𝑥6 − 𝑠𝑥4 𝑐𝑥6 ) = 0  𝑥 9 = 𝑧 = 𝑔 − 1 𝑚 𝑇(𝑐𝑥4 𝑐𝑥5 ) = 0  𝑥 10 = 𝑝 = 𝑑𝑏 𝐼𝑥 𝑢4 − 𝑢2 − 𝐼𝑧 −𝐼𝑦 𝐼𝑥 𝑥11 𝑥12 = 0  𝑥 11 = 𝑞 = 𝑑𝑏 𝐼𝑦 (𝑢1 − 𝑢3 ) − 𝐼𝑥 −𝐼𝑧 𝐼𝑦 𝑥10 𝑥12  𝑥 12 = 𝑟 = 𝑘 𝐼𝑧 (𝑢1 − 𝑢2 + 𝑢3 − 𝑢4 ) − 𝐼𝑦 −𝐼𝑥 𝐼𝑧 𝑥10 𝑥11  from equation (31) and (32), it was obtained: 𝑠2𝑥5 + 𝑡 2𝑥4 = 0  the only solution for this equation is x4 = 0 and x5 = 0. by combining the results with equation (28), (29), and (30) following state can be obtained as x10 = 0, x11 = 0 and x12 = 0. using assumption that the equilibrium point is located at certain positions in cartesian coordinate (x, y, z) and at some yaw angle positions is defined by x = y = , z = and = . so, the complete list of the state variables value in this equilibrium, x(), can be written as x1 = α, x2 = β, x3 = γ, x4 =0, x5 = 0, x6 = δ, x7= 0, x8 = 0, x9 = 0, x10 = 0, x11= 0, and x12= 0. remark 1. it can be noted that in the equilibrium, unless the arbitrary position and the yaw angle, all of the state are zeros. the state equation for the linearized state space model is represented by: 𝑥 = 𝐴𝑥 + 𝐵𝑢 𝑦 = 𝐶𝑥 + 𝐷𝑢.  where the matrix a and b can be found by using following equation. 𝐴 = 𝜕 𝑓1 𝜕𝑥1 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋯ 𝜕 𝑓1 𝜕𝑥12 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋮ ⋱ ⋮ 𝜕𝑓12 𝜕𝑥1 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋯ 𝜕𝑓12 𝜕𝑥12 |𝑋(𝛼, 𝛽, 𝛾, 𝛿)  𝐵 = 𝜕𝑓1 𝜕𝑢1 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋯ 𝜕𝑓1 𝜕𝑢12 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋮ ⋱ ⋮ 𝜕𝑓12 𝜕 𝑢1 |𝑋(𝛼, 𝛽, 𝛾, 𝛿) ⋯ 𝜕𝑓12 𝜕𝑢12 |𝑋(𝛼, 𝛽, 𝛾, 𝛿)  by careful calculation it was found that: 𝐴(12×12) = 𝑂 6×6 𝐼 6×6 𝑂 2×2 𝑁 2×2 𝑂 2×1 𝐼 6×6 𝑂 4×6   and 𝐵 12 ×4 = 𝑂 8×4 𝑀 4×4 (42) where o is zero matrix and i is identity matrix. while n and m can be defined as: 𝑁 2×2 = −𝑔𝑠𝛿 −𝑔𝑐𝛿 𝑔𝑐𝛿 𝑔𝑠𝛿  𝑀 2×2 = − 𝑏 𝑚 − 𝑏 𝑚 0 − 𝑑𝑏 𝐼𝑥 − 𝑏 𝑚 − 𝑏 𝑚 0 𝑑𝑏 𝐼𝑥 𝑑𝑏 𝐼𝑦 0 𝑘 𝐼𝑧 − 𝑘 𝐼𝑧 − 𝑑𝑏 𝐼𝑦 0 𝑘 𝐼𝑧 − 𝑘 𝐼𝑧  for simulation purpose, the constants which are going to be used is set as g = 9.81 m/s 2 , ix = 0.0820 kg.m 2 , iy = 0.0845 kg.m 2 , iz = 0.1377 kg.m 2 , b = 1.2953 x 10 -5 kg.m, d = 0.165 m, k = 1.0368 x 10 -7 kg.m 2 , m = 4.34 kg. the output of this quadrotor model is defined by the vector y = [x y z ] t , so the matrix c can be written as: m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 12 𝐶 4×12 = 𝐼 3×3 𝑂 3×9 𝑂 1×3 𝐿 1×3  where 𝐿 4×12 = [0 0 1 0 0 0 0 0 0]  finally, the linearization model of this quadcopter is: 𝑥 = 𝐴12 ×12 𝑥 + 𝐵12 ×4𝑢  𝑦 = 𝐶12 ×1𝑥  remark 2. it can be seen from equation (41) to (45) that most of the components of the linearized state space model are zero components. remark 3. here matrices a, b, and c as sparse matrices and the corresponding state equation is called by the systems with sparseness property. d. controlability and observability before designing the controller or the observer, it has been checked the controllability and observability of the system. define the controllability matrix as: 𝑃𝑐 = [𝐵 𝐴𝐵 𝐴2𝐵 ⋯ 𝐴𝑛−1𝐵]  where n defines the order of the system. in this case, the matrix can be written as: 𝑃𝑐 (12 ×48 ) = [𝐵 𝐴𝐵 𝐴 2𝐵 ⋯ 𝐴11 𝐵]  𝑃𝑐 4×12 = 𝑂 8×4 𝑀 4×4 𝑂 2×4 𝑀 4×4 𝑂 6×4 𝑂 6×4 𝑅 2×4 𝑂 4×4 𝑅 2×4 𝑂 10 ×4 𝑂 8×4 𝑂 12 ×36 (51) where 𝑅 2×4 = − 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑦 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑥 − 𝑔𝑠𝛿 𝑑𝑏 𝐼𝑦 − 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑥 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑦 − 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑥 𝑔𝑠𝛿 𝑑𝑏 𝐼𝑦 𝑔𝑐𝛿 𝑑𝑏 𝐼𝑥  from the above equation is concluded the following proposition. proposition 1. the linearized sytems with components in equation (41) to (45) are controllable regardless of the value of and  proof. the controllability matrix equation (51) has unique configuration of the matrix element. only prove that the rank of the controllability matrix will always be full rank is needed, i.e., rank of 12, regardless of the value of and . using standard reduced row escelon form, the systems should be converted into a perfect triangular matrix thus the prove that the system is controllable can be concluded. by the definition, the matrix observability can be written as: 𝑃𝑜 (48 ×12 ) = 𝐶 𝐶𝐴 𝐶𝐴 2 ⋯ 𝐶𝐴11 𝑇  𝑃𝑜(48×12) = 𝜒1 4×12 𝜒2 4×12 𝜒3 4×12 𝜒4 4×12 𝑂 32×12 𝑇  where 𝜒1 4×12 = 𝐼 3×3 𝑂 3×9 𝑂 1×3 𝐿 1×9  𝜒2 4×12 = 𝑂 4×6 𝐼 3×3 𝑂 1×3 𝑂 4×2 𝑍 4×1  𝜒3 4×12 = 𝑂 4×3 𝑁 2×2 𝑂 4×7 𝑂 2×2  𝜒4 4×12 = 𝑂 2×9 𝑁 2×2 𝑂 4×1 𝑂 2×2  and 𝑍 4×1 = 0 0 0 1 𝑇  then the observability of the systems as summarized in the following preposition can also be concluded. preposition 2. the above linearized system is also always observable regardless of the variation of the value of and . proof. the proof is very similar with the proof of the first preposition, thus to save space, it is omited. remark 4. what makes this result interesting is the fact that the controllability and observability depend on the equilibrium point in the beginning, which is at x = y = , z = and = eventually, the property of matrix a and b depended only on the yaw angle value. from the above remark, the system can be controlled by more advanced adaptive controller technique such as gain scheduling without concerning the controllability and observability of the system. for gain scheduling, the controller matrix k will depend on the value of yaw angle and will be both controllable and observable for all . iii. controller implementation before discussing the gain scheduling that is going to explain in the next section, the novel method for implementing the controller is proposed. it can be observed from the derived model in the previous section that the linearized dynamics of the quadcopter are dominated by chain of integrator. the controller design strategy is based on exploiting this fact by restructuring m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 13 the state variable to its jordan form to emphasize the sparseness of the dynamics [8]. from the restructured states, a pole placement controller is designed. both of the designed controllers are then re-transformed to the original state space. the aim of controller design in this article is to formulate a gain matrix k for state-feedback controller, such that the eigen value of a matrix (a+bk) coincides with the desired dynamics pole. the method employed in this article is based on a notion of matrix similarity. a pair of matrix a and b are called similar if there is a similarity transformation p such that: 𝐵 = 𝑃𝐴𝑃−1  one of the interesting characteristics of similarity transforms is that the eigen value of the matrices are preserved under the similarity transformation. in this article, the transformed matrix of a matrix a is denoted as a. the similarity transform used in this article are the transformation matrix from the original state notation to a new state notation x composed of: 𝒙′ = [𝜖𝑥 𝑥 𝑥 𝛼1𝜑𝑟 + 𝛼2𝜑𝑝 𝛼1𝜑 𝑟 + 𝛼2𝜑 𝑝 𝜖𝑦 𝑦 𝑦 𝛼3𝜑𝑟 + 𝛼4𝜑𝑝 𝛼3𝜑 𝑟 + 𝛼4𝜑 𝑝 𝜖𝑧 𝑧 𝑧 𝜖𝑦 𝜑𝑦 𝜑 𝑦 ] 𝑇  the matrix used for this similarity transform can be found on the appendix. the resulting matrix from this similarity transform is: 𝐴′ = 𝐻5×5 0 0 0 0 0 𝐻5×5 0 0 0 𝐻5×5 0 0 0 0 𝐻5×5   with hn × n is an n × n matrix such that: 𝐻𝑛 ×𝑛 = 0 𝐼𝑛 −1×𝑛−1 0 0   by changing the last row of h matrix with row vector [a1 . . . an] the h matrix become a controller canonical matrix with characteristics polynomial as: 𝐻 𝑠 = 𝑎1 + 𝑎2𝑠 2 + ⋯ + 𝑎𝑛 𝑠 𝑛 + 𝑠𝑛 +1  the other interesting property of a is that by separation principle, the poles of each h can designed without regarding the poles of other blocks. this property permits to do pole placement of each h matrix separately. for a hn × n matrix, n number of poles (p1 . . . pn) are selected. the desired characteristics polynomial is given by: 𝐻𝑖𝑑 𝑠 = (𝑠 − 𝑝𝑖 ) 𝑛 𝑖=1 = 𝑎1 + 𝑎2𝑠 2 + ⋯ + 𝑎𝑛 𝑠 𝑛 + 𝑠𝑛 +1  the coefficients of the desired polynomial (a1 . . . an) are then inserted as [a1 . . . an] to the last row of h. such the desired dynamics matrix of the systems is given by: 𝐴𝑖𝑑 ′ = 𝐴′ + (𝐵𝐾)′ 𝐵𝑖𝑑 ′   the bid is the collection of h blocks last rows that control the dynamics of the systems. by simple algebraic manipulation, the desired b and k can be derived from a bid. the k are calculated as: 𝐾 = 𝐵† (𝑃−1𝐵𝑖𝑑 ′ 𝑃)  the b † matrix is defined such that for every vector v this relation hold: 𝑣 = 𝐵†𝐵𝑣   matrix b has a special structure as: 𝐵† = [𝑂4×8 𝐵𝑠𝑢𝑏 𝑇 𝑂4×4 ]  then matrix b † can be defined as: 𝐵† = [𝑂4×8 𝐵𝑠𝑢𝑏 −1 𝑂4×4 ]  the bsub matrix has same structure with the haar wavelet analysis matrix [9], these structures ensures that bsub matrix are invertible as long the coefficients are not zero. a. block diagram of controller in this work, the gain will be computed using lqr via gain scheduling. however, pole placement is used in this section for clarity. the naive implementation of the controller will need 48 multiplication and addition. this stems from the fact that the designed gain matrix is not sparse under the original state base. the approach in implementing the designed controller is by using a pre-filter and post-filter before the controller to transform the signal between bases. the formula of gain as given in equation (67) can be divided as follows. 𝐾 = 𝐵†𝑃−1 𝑃𝑜𝑠𝑡 −𝑓𝑖𝑙𝑡𝑒𝑟 𝐵𝑖𝑑 ′ 𝐶𝑜𝑛𝑡𝑟𝑜𝑙𝑙𝑒𝑟 𝑃 𝑃𝑟𝑒 −𝑓𝑖𝑙𝑡𝑒𝑟   the value of b † are fully parameterized by the physical construction of the quadcopter. thus the gains of this part are static for each quadcopter type. this fact is reflected in designing the controller by only using static gain and adder for this part of post-filter. the p -1 part of the postfilter would only permute the position of control signal, thus does not need any mathematical operation to be implemented. the block diagram of the implementation is shown in figure 2. m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 14 the pre-filter part of the implementation is composed of permutation of state structure, eight multiplication blocks and four addition blocks. in the original gain-scheduling method in the next section, the entire gain has to be calculated for each yaw value. however, by using this implementation the equivalent process is achieved by changing the coefficient { a1, a2, a3, a4 }. the block diagram of the implementation is shown in figure 3. the implementation for the controller with desired poles in -1 is shown in the block diagram in figure 4. b. numerical experiment the numerical experiment is conducted by using quadrotor model from peter corke’s robotic toolbox [1]. the controller is implemented using simulink block. there is two numerical experiment performed. the first experiment shows the ability of the controller to achieve desired height. the second experiment shows the ability of the controller to stabilize its height given a force impulse. time constant for controller in figure 5 is 0.998, it closely resembles a linear system with corresponding poles in -1, while the time constant for controller in figure 6 is 0.644. the controlled system also differs with the linear system by the existence of overshoot in both controllers. the second experiment is conducted by giving force impulse during the period of 7s to 8s. this experiment is aimed to shows the ability of the controller to correct disturbance due to external forces. the experiment is conducted using a controller with poles in -2. the result of this experiment is shown in figure 7. it is shown figure 2. block diagram implementation of post – filter figure 3. block diagram implementation of pre-filter figure 4. block diagram implementation of controller figure 5. step response for controller with -1 poles figure 6. step response for controller with -2 poles figure 7. controller response to disturbance m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 15 that the controller is able to correct the error due to force impulse. iv. control system design knowing the controllability and observability property that is independent of the position and yaw movement of the systems, the usage gain scheduling controller is opted. for simplicity, the gain in each of system’s structural changing due to the change of eign structure is going to be computed using lqr formalism. moreover, in order to give more insight, hereby the controller directly was implemented into the original nonlinear system equation (7) to (23) using the series of numerical studies. a. linear quadratic regulator linear quadratic regulator is a control method using state feedback law u = kx to minimize the cost function, defined as: 𝐽(𝑢) = 𝑥𝑇𝑄𝑥 + 𝑢𝑇𝑅𝑢 𝑑𝑡 ∞ 0  where q is weight matrix for state energy and r is weight matrix for input energy. the matrix k can be derived from equation (73). 𝐾 = 𝑅−1 𝐵𝑇 𝑆 + 𝑁𝑇  while the matrix s is solution for the riccati equation: 𝐴𝑇𝑆 + 𝑆𝐴 − 𝑆𝐵 + 𝑁 𝑅−1 𝐵𝑇𝑆 + 𝑁𝑇 + 𝑄 = 0 in order to solve matrix k, one have to give numerical value for  so that all numerical values of matrix a and b can be obtained. for simplicity, choose the weight matrix q and r as q = qi12×12, r = ri4×4, where q = 10,000,000,000 and r = 0.0000000001. a small value for weight matrix r is chosen because of the minimal energy of input signal is desired. in order to make the quadrotor able to maintain its altitude, a great amount of energy for input signal is used. however, in order to include the effect of motor saturation, a maximum and minimum boundary of the motor’s rotational speed is also used (which is square root of the input signal) according to the [1], where i;max = 1,000 rpm and i;min = 700 rpm for all i = {i : 1 ≤ i ≤ 4|i  z }. here, it was choosen the value for  = 0.5. the matrix k obtained from the lqr is: 𝐾 4×12 = 𝜉 × [𝑈 4×4 𝑉 4×4 𝑊 4×4 ]  where  is a constant, its value is 1.0 × 10 10 and 𝑈 4×4 = −0.6205 −0.3390 0.3390 −0.6250 −0.5000 0.0000 −0.5000 −3.8392 0.6205 0.3390 −0.3390 0.6250 −0.5000 0.0000 −0.5000 3.8392 ,  𝑉 4×4 = 3.8392 0.5000 0.0000 −0.5000 −0.9007 −0.4921 0.4921 −0.9007 −3.8392 0.5000 0.0000 −0.5000 0.9007 0.4921 −0.4921 0.9007 ,  𝑊 4×4 = −0.5000 0.0000 −0.5000 −0.7071 0.7071 0.5000 0.0000 −0.5000 −0.5000 0.0000 −0.5000 0.7071 −0.7071 0.5000 0.0000 −0.5000  using the matrix, which has been mentioned above to produce input signal based on the state feedback law u = kx and fed the input signal to then on-linear model of quadrotor. in this part, the result for non-linear model quadrotor attitude and altitude control using the state feedback controller that is obtained by using the linearized model property of quadrotor is presented. figure 8 shows the quadrotor altitude with initial condition z = 0 to steady state condition z = 5. while, figure 9, shows the quadrotor yaw angle with initial condition = 0 to steady state condition  = 0.5. as the picture shown, the state feedback controller obtained from the linearized model of the quadrotor can be concluded to works well. there is no overshoot seen and the system does not need much time to reach the stability. when changing the value of variable = 1, the result was got as seen in figure 10 and figure 9. altitude yaw, for δ = 0.5 figure 8. altitude z, for δ = 0.5 m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 16 figure 11. through this simulation, it can be concluded that proposed controller is effective. b. observer to verify the observability of the system, linear feedback observer also known as luenberger observer is applied. the state space equation of the estimated state can be written as follow. 𝑥 = 𝑓 𝑥 + 𝐿(𝑦 − 𝐶𝑥 )  where l is the luenberger matrix gain and f(x) is nonlinear function describing the quadrotor model as explained in equation (25) until (36). it can be determined that the matrix l using the pole placement strategy. the eigen value of matrix (a + lc) is designed to have value 1.5 times the poles of the controller, which is the eigen value of matrix (a + kb). to make sure that the error of the observer, the difference between the real state and estimated state, is close to zero fast enough before the states value is forced to close to the desired value by the controller. the value of matrix l is: 𝐿 12 ×4 = 𝜁 × 𝑋 4×4 𝑌 4×4 𝑍 4×4 𝑇  where 𝜁 is a constant, its value is 1.0 × 10 6 and 𝑋 4×4 = 0.5319 −0.0475 −0.0475 0.0438 0.0081 0.0005 0.0319 −0.0091 0.0080 0.0319 −0.9690 0.1999 0.1124 −0.1307 0.0788 −0.0269 , () 𝑌 4×4 = −1.4502 0.0675 0.0005 −0.0091 −0.0730 0.0128 −0.1307 0.5135 4.3321 −0.3868 −0.3867 −0.3568 0.0656 0.0042 0.2596 −0.0741 , () 𝑍 4×4 = 0.0121 0.0478 −1.0013 0.2066 0.1686 −0.1960 0.0814 −0.0278 −1.4986 0.0698 0.0008 −0.0136 −0.0754 0.0132 −0.1960 0.7702 () in figure 12 until 15, the real states drew can be seen in blue line and the estimated states in red line are convergent. for all the states, the observer seems to works well. through this simulation, the observability of the linearized model of quadrotor has been approved. figure 10. altitude z, for δ = 1 figure 11. altitude yaw, for δ = 1 figure 12. state 1 to state 3 m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 17 figure 13. state 4 to state 6 figure 14. state 7 to state 9 figure 15. state 10 to state 12 m.q. abdurrohman et al. / j. mechatron. electr. power veh. technol 06 (2015) 9–18 18 v. conclusion in this paper, the linearized model of quadrotor simplified model is obtained and show that the system is controllable and observable regardless of the value of reference position in cartesian coordinate as well as the reference yaw angle. it is found from the linearization that the system has mostly zero components thus can be considered as a sparse system. by rearranging into its respective jordan form finally via similarity transformation the number of components can be reduced from 48 to 8 plus one permutation and one addition blocks. a numerical study of the implementation said that the scenario worked well. finally, the gain scheduling controller whose gains are designed via lqr approach is proposed. the simulation results said that the proposed controller that is implemented in the original system using the sparseness property was effective. appendix the similarity matrix for transforming the states is given as: 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 𝑎1 0 0 0 0 0 0 0 0 0 0 𝑎2 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 𝑎1 0 0 𝑎2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 𝑎3 0 0 0 0 0 0 0 0 1 0 𝑎4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 𝑎3 0 0 𝑎4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 acknowledgement the authors would like to thanks to japan international for cooperation agency (jica) for their kind support in providing the collaborative grant for researches alumnae. references [1] p. i. corke, robotics, vision and control: fundamental algorithms in matlab, ser. springer tracts in advanced robotics. berlin: springer, 2011, no. v. 73. [2] p. pounds, et al., “modelling and control of a quad-rotor robot,” in australasian conference on robotics and automation, auckland, new zealand: australian robotics and automation association inc., 2006. [3] s. bouabdallah, et al., “pid vs lq control techniques applied to an indoor micro quadrotor” in intelligent robots and systems (iros 2004), vol 3, 2004, pp. 2451-2456. [4] s. gaikwad, et al., “auto-tuning pid using loopshaping ideas,” proceedings of the 1999 ieee international conference on control applications, vol. 1, 1999, pp. 589-593. [5] x. liu, et al., “design of self-adaptive pid controller based on least square method.” 3 rd international conference on genetic and evolutionary computing, ieee., oct. 2009, pp. 527-529. [6] n. tamami, et al., “proportional derivative active force control for “x” configuration quadcopter”, journal of mechatronics, electrical power, and vehicular technology, vol.5, pp. 67-74, 2014. doi: 10.14203/j.mev.2014.v5.67-74. [online]. available: www.mevjournal.com [7] h. k. khalil, nonlinear systems, 2nd ed. upper saddle river, nj: prentice hall, 1996. [8] k. busawon, “control design using jordan controllable canonical form,” proceedings of the 39th ieee conference on decision and control, vol. 4, 2000, pp. 3386–3391. [9] s. g. mallat, a wavelet tour of signal processing the sparse way. amsterdam; boston: elsevier /academic press, 2009. microsoft word vol03_no2 yg dioprek neli sutisno dan muhida-nya journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 03, issue 2, december 2012 insured editor head of the research centre for electrical power and mechatronics editor-in-chief dr.eng. estiko rijanto (control system and mechatronics engineering) managing editor tinton d atmaja, m.t. (information system and electrical engineering) peer reviwers dr.-ing. moch ichwan (vehicular technology; lipi) ir. edi leksono, m.eng., phd. (electrical engineering; itb) dr. ahmad agus setiawan (renewable energy systems; ugm) ir. arko djajadi, ph.d. (mechatronics; swiss german university) dr.eng. estiko rijanto (mechatronics and control systems; lipi) pudji irasari, m.sc.rer.nat. (electrical engineering/electric machines; lipi) dr.eng. anindito purnowidodo, s.t., m.eng. (mechanical engineering; unibraw) dr. ir. yoyon ahmudiarto, m.sc., ipm. (electrical power; lipi) dr. ir. zainal abidin (mechanical engineering; itb) advisory editor rachmini saparita, phd. (interdisciplinary engineering) copy editors achmad praptijanto, m.eng. (mechanical engineering) nur rohmah, m.t. (chemical engineering) proofreader naili huda, m.eng.sc (industrial engineering) ghalya pikra, m.t. (energy conversion) subscription manager noviadi a rachman, m.t. (electrical engineering) secretariat andri j purwanto, s.t. (mechanical engineering) mella p susantika, a.md. (information management) section editors merry i devi, s.t. (industrial engineering) vita susanti, s.kom. (computer science) layout editors aam muharam, m.t. (electrical engineering) arief a firdaus, s.i.kom. (communication science) web admin dadan r saleh, m.t. (informatics engineering) graphic designer m. redho kurnia, s.sn. (graphic design) mechatronics, electrical power, and vehicular technology (mev) is a journal aims to be a leading peerreviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics. mev is published and imprinted by research center for electrical power and mechatronics indonesian institute of sciences and managed to be issued twice in every volume. for every edition, the online edition is published earlier than the print edition. journal address secretariat research centre for electrical power and mechatronics – indonesian institute of sciences komp lipi jl. sangkuriang, building 20, 2nd floor, r 209, bandung, west java, 40135 indonesia telp: +62-022-2503055/2504770 fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com homepage: www.mevjournal.com; www.telimek.lipi.go.id/mev.htm journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 03, issue 2, december 2012 foreword from editor-in-chief the journal of mechatronics, electrical power, and vehicular technology (mev) has been acreditated by the indonesian institute of sciences (lipi) in april 2012. it started using open journal system (ojs) since the online publishing of the third volume released in july 2012. this issue of the journal mev publishes eight papers with the total number of paper pages is 60 pages. in comparison with the previous issue, we have achieved an increment of one paper and 4 paper pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. five topics are related to mechatronics and three topics to electrical power. six papers are written in english and two papers are written in bahasa indonesia. the policy up to this current issue is that both authors and readers are not charged at all. on the other hand, the editorial board is planning to lift the quality up by promoting papers written in english to reach international readers as well as registering the journal to the international academic citation index. moreover, the editorial board is also considering to gradually encrease the number of papers and journal’s pages. all of this plan will give consequence on financial burden. therefore, from the next issue, financial policy will change based on that condition. we wish to offer our thanks to all the editorial board members and administration division of the research center for electrical power and mechatronics for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s peer reviewers: ir. arko djajadi, ph.d., dr.ing. moch ichwan, dr. ahmad agus setiawan, ir. edi leksono, m.eng., p.hd., pudji irasari, m.sc.rer.nat., dr. yoyon ahmudiarto, dr. zainal abidin, and dr. anindito purnowidodo. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2012 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 03, issue 2, december 2012 list of contents development of swept-sine excitation control method to minimize the frf measurement error asmara yanto, zainal abidin 57-64 a review of atomic layer deposition for nanoscale devices edy riyanto, estiko rijanto, budi prawara 65-72 effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection agus risdiyanto, noviadi arief rachman, maulana arifin 73-80 the effect of the addition of active digester effluent for start-up accelerator in anaerobic digestion of soybean curd industry waste water (basic research for biogas power generation) arini wresta, wiratni budhijanto 81-86 analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator hilman s. alam, pudji irasari, dyah kusuma dewi 87-94 design of a dc-ac link converter for 500w residential wind generator riza muhida, ahmad firdaus a. zaidi, afzeri tamsir, rudi irawan 95-102 analysis and development of walking algorithm kinematic model for 5-degree of freedom bipedal robot gerald wahyudi setiono, prianggada indra tanaya, henricus riyanto hendradji 103-110 vibration disturbance damping system design to protect payload of the rocket sutisno, andreas prasetya adi 111-116 mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.107-114 design and development of rc railed robot for coffee nursery logistics marivic g. dizon a, *, carlo t. sevillano a , mark anthony t. cabaluna a a cavite state university, indang, cavite, 4122 philippines received 09 september 2014; received in revised form 30 october 2014; accepted 02 november 2014 published online 24 december 2014 abstract the remote controlled (rc) railed robot was designed and developed to transfer polybags from manual operation to an automated logistic system. gizduino microcontroller was used to read and interpret commands sent and received by the transceivers to the robot and a remote to command instructions to the robot. the project was tested and evaluated at the coffee nursery of cavite state university by determining the speed of the robot, the effectiveness of the remote control and the accuracy of the robot to lift a pallet and place it into an empty space. results showed that the robot was able to receive and interpret commands provided by the remote control as well as perform the tasks successfully. the most significant recommendation was to use a counterweight at the rear side of the robot to avoid unnecessary derailments of the robot if lifting the heavier or greater number of pallets is desired. keywords: remote control, coffee nursery, gizduino microcontroller, automated logistic system. i. introduction coffee is one of the most valuable primary products in world trade, but coffee seeds grow slowly during cold weather. to achieve faster seed growth during this weather, the seed should be planted in a clear plastic or polyethylene bag and placed in a coffee nursery beneath a shade. the nursery includes the seedbeds or germination beds where the seeds are sown to germinate and produce seedlings as well as nursery beds where the seedlings are nurtured until they are ready for planting out in the field [1]. the existing method of nursery logistics in the cavite state university coffee center is through manual operation. since this type of method is very laborious and tedious, nursery logistics can be operated automatically using a remote controlled robot that navigates into a railway to overcome this kind of problem [2]. several components such as microcontroller can be used for taking input from a device and control it by sending signals to different components in the system [3]; dc motors that uses electricity and a magnet to produce torque in order to turn the motor [4]; transceiver for transmitting and receiving data from a wireless communication [5]. another component is sensors that detect changes in a certain condition or in the state or another device [6]. the remote controlled (rc) railed robot was designed and developed to provide an alternative way of transferring polybags from manual operation to an automated logistic system for the coffee nursery. by developing a remote controlled robot, it would reduce the drudgery in moving seedlings from one location to another which is essential in reducing plant populations to account for canopy growth. it was composed of microcontroller unit, dc motors, transceiver, sensors, and powered by a 12v power supply. the gizduino microcontroller board reads and interprets commands sent and received by the transceivers to the robot. a remote control unit was used to command instructions the robot has to perform. ii. methodology this chapter involves the development and design perspective, the steps and procedures in the development of the remote controlled railed robot for coffee nursery logistics. this also covers dry-run and evaluation procedures and techniques to determine the acceptability of the system. * corresponding author. phone: +63-9173519855 e-mail: mavic_mgd2001@yahoo.com http://dx.doi.org/10.14203/j.mev.2014.v5.107-114 m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 108 a. design and construction of microcontroller circuit two microcontroller units were used in the study, both of which were arduino based, gizduino atmega328. the control unit served as the brain of the robot since it tells when to allow the execution of an operation. the circuit of the controller was first designed, set up and tested in a breadboard to check its operation. pins and socket were used to prevent any damages in the testing. the design layout shown in figure 1 was plotted in the pcb, after the circuit has been thoroughly developed and tested. the board was soaked in a developer solution until the layout becomes visible. the pcb was rinsed in water, fabricated, and tested for the continuity of every line using a multimeter. when no errors are detected, the board was drilled according to the pin layout of the circuit and was soldered. the microcontroller circuit has its own platform that was connected to the motor drivers, sensors, and motors. this included h-bridge motor driver, relay boards that switched which motor would operate, a voltage regulator that regulates the output voltage from 12.9 and 5 v, ultrasonic and proximity sensors, wiper and power window motors. the microcontroller circuit was placed at the inner part of the robot to prevent the damage of components during the operation. once all the units held together firmly, it was paired through connecting wires to the load cell and the direct current motors. b. system development the remote control consisted of uhf data transceiver and microcontroller unit with 4x3 encoder circuit to have a unique identity of each value in the keypad. after determining the pin configurations of the data transceiver and identities of a keypad, the circuit layout for the remote control shown in figure 2 was drawn on a tracing paper and was tested on a breadboard. the transparency films were drafted and attached on a double sided presensitized printed circuit board (pcb). the printed circuit board layout shown in figure 3 was soaked and etched using a ferric chloride. all the necessary connections had been checked using a multi tester and perforated using a drill bit. the transmitter in the remote control transmits commands depending on the buttons pressed in the keypad which the rf receiver receives. the received command will be interpreted by the microcontroller. the microcontroller then sends commands to the motors which serve as the output. motor 1 controls the mobility of the robot. motor 2 controls the rotation of the upper part of the robot figure 2. keypad to the microcontroller unit configuration figure 3. pcb layout of the remote control unit figure 1. pcb layout of the microcontroller circuit m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 109 whether the input command would be to rotate to the left or rotate to the right side. it was then connected to three limit switches indicating the position of the pivot mechanism. motor 3 was designated for the retraction of the fork lift. motor 4 is for lifting and dropping of the pallets that contains polybags. ultrasonic sensor was used as an input to determine if a pallet is present in a station. it was placed at the bottom left and right of the device. the ultrasonic sensor and limit switch were directly connected to the digital input pins of the microcontroller and the data transceiver i/o pins were connected to tx and rx of the microcontroller and were programmed to function as a receiver. another transceiver interfaced to the second microcontroller was programmed to function as a transmitter. this was the remote control unit that emits the input signals that the main microcontroller unit receives. the motors were connected to the digital output pins of the microcontroller and responds according to the input signals received by the main microcontroller unit transmitted by the remote control unit. c. software development the system software was first designed in a flowchart which is necessary to present the step by step operation of the system as shown in figure 4. the programs were checked for errors and debugged once error occurs and analysis was done to come up with an accurate program to control the operation of the system. the software was programmed using the arduino language. the remote control unit was programmed to have multiple buttons for eight stations, start and stop, and enter. the main microcontroller unit was programmed to control mobility of the robot and the function of the fork lift. d. design and construction of the railway for the robot steel angle bars ¾ × 1 inch were used as the railway for the robot. it was placed inside the coffee nursery to designate stations for the robot. there were eight stations for the robot labeled as a to h and a base station which was labeled a where the robot stops after placing the pallet in its destination. the layout of the railway for the robot is shown in figure 5. figure 4. program flowchart of the system m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 110 e. testing and evaluation of the system the system was tested and evaluated at the national coffee research development and extension center of cavite state university, indang, cavite by the faculty members of the department of computer and electronics engineering of cavite state university, indang. the system underwent a test run for a week to evaluate its function, capability, limitations and accuracy of the system to determine if the robot can execute the command from the remote control accurately. the strength of the forklift was also tested and evaluated to determine the number of polybags it can handle. iii. results and discussion this chapter presents the results of the study, analysis, and interpretation of data gathered with the end view of answering the research problem. a. presentation and analysis of design the remote controlled railed robot was designed mainly to be used in the national coffee research development and extension center for coffee nursery logistics. figure 6 shows embodiment of rc railed robot. the design project consisted of the following: small bike wheels, ultrasonic sensors, wiper motors, power window motors, infrared proximity anticollision sensor, data transceiver, battery, hbridge motor driver, and a microcontroller unit. motor 1 controls the mobility of the robot. motor 2 is for the rotation of the upper part of the robot. motor 3 was designated for the retraction of the fork lift. motor 4 is for lifting and dropping of the pallets. a remote control was also designed using the same microcontroller unit, a voltage divider used as an encoder, and a transceiver for the transmission of the commands. b. principles of operation the major function of the remote controlled railed robot is to transfer coffee seed bags from one place to another using the remote controller supplied by a 9 v rechargeable battery. once the command is transmitted to the rf receiver, it will be interpreted by the microcontroller (see figure 7). the battery will start to supply power to the main controller of the system which is arduino atmega328 with 40 ma output and the h-bridge motor driver with 50 ma output to the designated destination. an ultrasonic sensor placed at the left and right bottom of the robot will detect if a pallet is present or not. the presence of the pallet will trigger the 12 v wiper motor to rotate exactly 90 degrees using a limit switch indicating that it is the end of the arc. the infrared proximity-collision sensor will give a signal to the microcontroller if the lifting device is on its right position to lift a pallet. the retraction system will continue to move forward to its limit and the lifting device will lift a pallet containing figure 5. nursery layout figure 7. system block diagram figure 6. rc railed robot m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 111 coffee seed bags. the system will continue until it reaches the desired destination and unloaded the pallets and goes back to the starting point. c. microcontroller circuit figure 8 shows photo of the developed microcontroller circuit. the microcontroller circuits were composed of gizduino atmega 328 microcontroller unit where all the inputs and outputs are connected. at a conceptual level, when using the arduino software stack, all boards are programmed over an rs-232 serial connection. the arduino board exposes most of the microcontroller's i/o pins for use by other circuits. the h-bridge motor driver controller was connected to the digital input/output pins of the microcontroller. the control of the speed of the motor was connected to digital pin number 3. the directions of the motor were connected to digital pin numbers 6 and 7. additional transistors and 5 volts contact triggering relays became the solution of the controller circuit. the output of the additional relays of the wiper motor and power window motor were connected to digital input/output pin number 12, 11, 10, 9, 8 and 5 depending on the motor that would function specifically. ultrasonic sensors were used to detect the presence of the pallets. the trigger input of right and left bottom ultrasonic sonar sensor were connected to digital input/output pin numbers 4 and 8. the echo of the ultrasonic sonar sensor was connected to analog inputs a4 and a5. limit switch was also used as an input to indicate that the pivot of upper mechanism is in 90 degrees and center position. it was connected to analog input a0 for its idle position. analog input a1 was for pivot left while analog input a5 was for pivot right position. relays with 5 volts contact voltage triggers which motor would be used in a given command of a user. d. sensors for detecting pallets compact ultrasonic sonar sensors were used for detecting pallets. it was a low cost solution for circuit applications that requires distance measurements from an object, such as walls or any object that can bounce back the sound wave. user circuit initiates a measurement by driving the ultrasonic sensor trigger input to logic high. in response, it will send short bursts of ultrasonic sound wave, and then outputs a pulse as soon as a returning echo is detected. the circuit resolves the distance by measuring the pulse width of the output pulse. distances of up to 4.5 meters from the sensor can be measured with resolving resolution depending mainly on the user circuit. proximity collision sensor detects as far as 25 centimeters from the sensor face. infrared beam makes it relatively insensitive to ambient light and color of target objects. applications include non-contact object detection and collision sensor for mobile robots. it was used for accurate retraction of the forklift to the pallets. e. remote control figure 9 shows the actual image of the remote control. the remote control of the robot consisted of a microcontroller unit, a voltage divider circuit, a transceiver, a 4 x 3 keypad with numbers from 1 to 0, a button for * and #, and an antenna. the identities of each pin of the keypads were identified using a voltage divider circuit. the microcontroller unit interprets the signal figure 8. microcontroller circuit wiring diagram m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 112 input from the keypad and transmits to the robot using the transmitter. f. software description the arduino is a cross-platform application written in java which is a c-based programming language used for the controller and receiver unit. starting from check input on the transmitter, this checked the system when the input command to the remote controller was triggered. if input is greater than or equal to serial available 0, the led that connected to pin 13 would blink, otherwise it would not blink meaning the command was not interpreted. in the receiver, if the data transceiver receives a signal coming from the transmitter, it would make the led in the pin 13 blink and checks if the received command is in mode1 or mode 2. if mode 1 is the input command, it would first check if the ultrasonic reading sensor is greater than or equal to 6,500. if yes, it would give high signal condition to motor1 telling it to move forward and search for available pallet. if the reading of the sensor is less than the given condition, it would not move forward. motor 3 would activate for retraction, get a pallet, and gives a signal to motor 1 to high condition indicating to move forward and search for a vacant place in the desired station. after putting the pallet in the vacant slot, it would go back to its starting point. if mode 2 is activated, it would start to give signals to three motors to high conditions sequentially with the given delay to pick up a pallet first in the starting point then move the pallet in the vacant slot. if there is no vacant space sensed by the ultrasonic sensor, it would move forward and search for a space to drop a pallet. after the given condition of the input command is done, it would go back to initial position of the robot in the rail and wait for another input. g. testing and evaluation the evaluation and testing were conducted at the national coffee research development and extension center, cavite state university, indang, cavite. the time travel of the robot to its destination with a different number of polybags and the effectiveness of the remote-controlled robot operation were recorded. the range of wireless data transmission of the remote control was also evaluated to ensure that transmission of data is properly working. figure 10 shows photo of the robot when transferring polybags. the results of the evaluation are shown in the table 1, table 2, and table 3. the data shown in table 1, that the number of polybags increases, then, the time travel of the robot also increases. however, the feet per minute and meters per minute are decrease. figure 9. remote control of the robot table 1. speed of rc railed robot at 5 meters no. of polybags (1.5 kg each) time travel (sec) speed ft/min m /min 0 23.2 70.8 21.6 1 24.3 67.5 20.5 2 25.9 63.2 19.3 3 27.9 58.7 17.9 4 31.7 51.7 15.8 table 2. speed of rc railed robot at 10 meters no. of polybags (1.5 kg each) time travel (sec) speed ft/min m /min 0 48.3 67.8 20.6 1 50.3 65.2 19.9 2 53.1 61.5 18.2 3 56.7 57.8 17.4 4 64.9 50.5 15.2 figure 10. the rc railed robot is transferring polybags. m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 113 as shown in table 2, the time travel of rc railed robot to the destination became longer depending on the number of polybags carried in the pallet. the data obtained show that the number of polybags and time travel is inversely proportional to feet per minute and meters per minute. at 15 meters, table 3 shows that increasing the number of polybags really affected the speed and time travel of the rc railed robot. moreover, the data imply that the feet per minute and meters per minute of the robot decreases when time travel becomes longer. the results have been shown by the test, the number of polybags increases in the pallet as the time travel to its destination becomes longer. the time travel and the speed are inversely proportional. the maximum number of polybags that the device can carry was four polybags with approximately 6 kilos in weight. if it increases its capacity, it would affect the performance and the balance of the rc railed robot and can cause to derailments. h. data transceiver a data transceiver is a device that is both a transmitter and a receiver which is combined and shares a common circuitry or a single housing. to examine the effectiveness of the data transceiver to the receiver unit, the remote control was tested in different distances several times. the rating used is shown in table 4. table 5 shows the results of the evaluation of the remote control in different distances. at 10 meters, the remote control successfully transmitted the commands to the rc robot. the expected function of the robot was achieved. at 20 meters, the robot did not complete the expected function at the 3 rd trial. after rotating 90 degrees right, it stopped suddenly. the receiver unit during first trial at 30 meters did not respond. the command coming from the sender at 40 meters was not successfully transmitted during first and third trial. at 50 meters, the rc railed robot did not respond from any command. the actual range effectiveness achieved from the transmitter to the receiver was only approximately 45 meters with interference including nets, trees, poles and posts. without any object blocking the signal of transmission, effective distance was 55 meters. iv. conclusion the robot was able to receive and perform the commands that came from the remote control. the robot was operated through the use of a remote control. the desired station and the mode of either picking up or placing a pallet selected through the remote control were properly initiated. the robot was able to carry a pallet from either its left or right containing a maximum of four polybags weighing approximately 6 kilos at the speed of 0.157 meters/second. the robot could only receive a command coming from the remote control at a maximum distance of 44.09 meters with interference and in a clear field at 55 meters. the sensors used worked accurately in detecting the presence of a pallet and in aiming the fork to the pallet. the switch used determined the current station of the robot. the speed of the robot was around 20.6 – 21.6 m/min while carrying no polybags and was around 15.2 – 15.8 m/min while carrying four polybags. the effectiveness ratio of the robot to receive a command from the remote control at 10 m was 100 percent, 30 m 73 percent, and 0 percent table 5. effectiveness ratio of the remote control from the receiver unit distance (m) trials effectiveness (%) 1 st 2 nd 3 rd 10 5 5 5 100 20 5 5 4 93 30 1 5 5 73 40 1 5 3 60 45 1 1 3 40 50 0 0 0 0 table 3. speed of rc railed robot at 15 meters no. of polybags (1.5 kg each) time travel (sec) speed ft/min m /min 0 71.6 68.7 20.9 1 74.8 65.8 19.7 2 80.3 61.3 18.5 3 85.7 57.8 17.9 4 94.2 52.2 15.2 table 4. reference for rating the accuracy of the remote control to the receiver unit rating description 5 excellent – exceeds the expected function of the robot. 4 satisfactory – meet all the functions of the robot. 3 fair – good enough for its use. 2 needs improvement – did not meet all the functions of robot 1 poor – not effective and no response from the receiver unit. m. g. dizon et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 107-114 114 effectiveness at 50 m. the data implies that as the distance increase from the receiver, the effectiveness ratio decreases. based on the results from the project, the following are highly recommended to enhance the device: enhancement of the infrared proximity sensor to an mk02 reed proximity switch for more accurate detection of a pallet containing polybags; and, use a counterweight at the rear side of the robot to avoid unnecessary lunging or derailments of the robot if lifting a heavier or greater number of pallets is desired. acknowledgement the authors would like to thank cavite state university for giving funds and allowing us to present the paper for international conference. also, to all the concerned faculty members and staff of the college of engineering and information technology for all the help and support that has been given. references [1] "about coffee," international coffee organization, 2006. [online]. available: http://www.ico.org/coffee_story.asp?section =about_coffee/ on april, 2012. [accessed april 2012]. [2] p. baltzan, "automation" business driven technology, 2012. [3] m. brain, "microcontroller unit," 1998. [online]. available: http://course.physastro.iastate.edu.pdf . [4] m. h.w., "cultivation and harvesting of the arabica coffee tree," coffee agronomy: ed. r.j. clarke, new york, 1998. [online]. available: http://library.thinkquest.org/04oct/01639/lig ht_en/science/plant/arabica/... [5] "microcontrollers and microcontrollers information," knighlight, 20000. [online]. available: http://www.knightlight.com.uk. [accessed april 2012]. [6] m. j., dictionary, prentice-hall international, united kingdomlimited, london england, 2000. [7] "engineer on a disk, a review on three technologies," 2012. [online]. available: http://engineeronadisk.com/v2/book_plc/e ngineeronadisk-20.html/ .on may 2012.. [accessed may 2012]. [8] a. b. a. b. j. a. malbino, digital computer eletronics 2 nd edition, mcmillan inc., 1993. [9] e. h. miller, "a note on reflector arrays," ieee transmission antennas propagation , 2012. [10] p. j. s. a. f. n., "what is dc motor," [online]. available: http://www.wisegeek.org/what-is-a-dcmotor.htm.. [accessed april 2012]. [11] j. a. b. k. seminara, "electric forklift motor," 2012. [online]. available: http://www.wisegeek.com/what-is-anelectric-forklift-motor.htm.. [accessed april 2012]. [12] s. j. a. f. n., "what are the different types of dc motors?," 2012. [online]. available: http://www.wisegeek.com/what-are-thedifferent-types-of[accessed january 2012]. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 57-64, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.57-64 uji coba awal parabolic trough solar collector parabolic trough solar collector initial trials ghalya pikra, agus salim, andri joko purwanto, zaidan eddy pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia ghalyapikra@yahoo.com; agus.salim35@yahoo.com; ajp_jun@yahoo.com; zaid001@lipi.go.id diterima: 28 oktober 2011; direvisi: 11 november 2011; disetujui: 15 november 2011; terbit online: 22 desember 2011. abstrak makalah ini membahas tentang uji coba awal parabolic trough solar collector (ptsc) yang dilakukan di bandung. model parabolic trough solar collector terdiri dari concentrator, absorber/receiver dan tracking system. concentrator merupakan alat penangkap panas matahari, sedangkan absorber/receiver adalah pipa yang berisi fluida yang akan menerima panas dari concentrator yang diletakkan pada titik fokusnya, dan tracking system adalah sistem kontrol untuk menggerakkan concentrator sehingga selalu bergerak menghadap ke arah matahari. desain concentrator dibuat dengan lebar aperture 2 m, panjang 6m dan jarak fokus 0,75 m. desain dilengkapi dengan sistem tracking otomatis yang digerakkan menggunakan motor dc 12 v dan 24 watt dengan kecepatan putar akhir 0,0125 rpm. absorber/receiver didesain dengan jenis evacuated tube, dengan pipa dalam yang memiliki diameter 1 inci berbahan aisi304 dan dilapisi oleh black oxide, pipa luar adalah kaca borosilicate dengan diameter 70 mm dan panjang 1,5 m. fluida kerja ditampung di dalam thermal storage jenis single tank, satu fasa dengan volume 37,7 liter. pengujian model solar collector yang dilakukan selama 2 jam 10 menit menghasilkan kalor output dan input masing-masing sebesar 11,5 kw dan 0,64 kw. kata kunci: solar collector, concentrator, absorber, sistem tracking. abstract this paper discusses initial trials of parabolic trough solar collector (ptsc) in bandung. ptsc model consists of concentrator, absorber and tracking system. concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. the design is equipped with an automatic tracking system which is driven using 12v and 24watt dc motor with 0.0125rpm rotational speed. absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of aisi304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. ptsc model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kw and 0.64 kw respectively. key words: solar collector, concentrator, absorber, tracking system. i. pendahuluan concentrated solar power (csp) adalah sistem yang memanfaatkan teknologi dengan prinsip mengumpulkan cahaya matahari dalam suatu media yang kemudian dikonversikan menjadi energi panas yang mana dalam proses selanjutnya dapat digunakan dalam suatu sistem yang menghasilkan listrik. sistem csp terdiri dari beberapa jenis, diantaranya sistem parabolic trough, sistem solar tower, sistem parabolic dish, dan sistem reflektor fresnel linear. parabolic trough solar collector merupakan salah satu jenis dari sistem csp yang banyak dikembangkan di berbagai negara karena hingga saat ini teknologi tersebut dianggap paling matang dan telah terbukti penggunaannya [1][2]. negara-negara yang telah mengembangkan sistem csp adalah algeria, mesir, yunani, india, italia, meksiko, moroko, spanyol, dan amerika [3]. lipi sejak tahun 2010 telah mengembangkan salah satu jenis sistem csp, yaitu jenis parabolic trough. sistem ini dipilih karena indonesia merupakan negara yang memiliki kelembaban yang tinggi. layout sistem pembangkit listrik matahari yang sedang dikembangkan oleh lipi ditunjukkan pada gambar 1. solar collector didesain dan dibuat dalam bentuk parabola, dan absorber/receiver terletak di titik fokus dari parabola [4]. energi matahari yang dikumpulkan oleh collector dipantulkan ke absorber yang ditempatkan di sepanjang garis pusat kelengkungan/fokus parabola. panas yang http://dx.doi.org/10.14203/j.mev.2011.v2.57-64 uji coba awal parabolic trough solar collector (ghalya pikra, a. salim, a.j. purwanto, z. eddy) jmev 02 (2011) 57-64 58 gambar 1. sistem pembangkit listrik matahari. diterima oleh absorber kemudian digunakan untuk memanaskan fluida kerja (oli) yang mengalir di dalam pipa absorber. fluida kemudian mengalir ke thermal storage untuk disimpan dan selanjutnya dialirkan ke evaporator dalam sistem orc (organic rankine cycle). fluida kerja di dalam evaporator kemudian memanaskan fluida kerja organik (refrigerant organic) yang kemudian dialirkan ke turbin untuk menghasilkan uap yang menggerakkan generator sehingga menghasilkan listrik. collector bergerak mengikuti arah matahari yang dikontrol oleh tracker yang terpasang pada solar collector. fuel burner dibuat sebagai pemanas bantuan apabila panas yang ditangkap oleh solar concentrator tidak dapat memenuhi kebutuhan. sistem orc turbin digunakan dalam sistem pembangkit listrik solar collector karena sistem ini dapat beroperasi pada temperatur rendah [5] [6]. penelitian ini bertujuan untuk melakukan uji coba awal dari sistem parabolic trough solar collector yang telah dibuat sejak tahun 2010. pengujian dilakukan hanya pada daerah solar collector dan thermal storage seperti yang ditunjukkan pada gambar 1 yang ditandai dengan garis putus-putus. pengujian dilakukan untuk mengetahui performa dari sistem solar collector yang telah dibuat, sehingga hasilnya dapat dievaluasi dan diperbaiki apabila belum menunjukkan nilai optimal. ii. parabolic trough solar collector parabolic trough solar collector (ptsc) terdiri dari solar concentrator, absorber dan tracking system. spesifikasi dari sistem ptsc yang telah dibuat ditunjukkan pada tabel 1. indonesia merupakan negara dengan kelembaban yang tinggi, sehingga jarak fokus dibuat dengan jarak yang dekat. pipa absorber dibuat dengan bahan stainless steel aisi304 dan dilapisi oleh black oxide agar penyerapan panas lebih optimal. selubung kaca dibuat dengan bahan borosilicate karena tahan terhadap panas. tracking system dibuat dengan menggunakan motor dc 12 v dan 24 watt dengan kecepatan putar akhir 0,0125 rpm. prototipe sistem yang telah dibuat kemudian dipasang di komplek pusat penelitian tenaga listrik dan mekatronik lipi kampus bandung, jawa barat. prototipe dari ptsc yang telah terpasang dapat dilihat pada gambar 2. tabel 1. data parabolic trough solar collector. data notasi nilai lebar aperture la 2 m panjang talang parabola p 6 m jarak fokus f 0,75 m diameter pipa absorber da 1 inchi diameter selubung kaca dk 70 mm journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 57-64, 2011 p-issn 2087-3379 59 gambar 2. prototipe parabolic trough solar collector. iii. metoda pengujian parabolic trough solar collector spesifikasi pengujian disusun untuk pengujian parabolic trough solar collector. performa penyerapan energi termal matahari pada spesifikasi pengujian ini diukur dari kemampuan sebuah sistem solar collector untuk memanaskan fluida kerja dari temperatur lingkungan ke temperatur tertentu pada interval waktu tertentu. perangkat pengujian sistem parabolic trough solar collector ditunjukkan pada gambar 3. untuk mendapatkan hasil pengukuran yang baik, pengujian dilakukan sesuai spesifikasi sebagai berikut. a. pemasangan solar collector pemasangan collector dilakukan di tempat terbuka sehingga tidak ada bayangan benda sekitar yang menutupi collector. b. instrumentasi instrumentasi yang digunakan dalam pengujian adalah solarmeter, thermometer, anemometer, dan stopwatch. gambar 3. perangkat pengujian. uji coba awal parabolic trough solar collector (ghalya pikra, a. salim, a.j. purwanto, z. eddy) jmev 02 (2011) 57-64 60 c. standar kondisi pengujian nilai intensitas matahari selama pengujian harus lebih besar daripada 700 w/m2 [7]. d. prosedur pengujian collector harus diuji pada temperatur operasinya dalam kondisi langit cerah dengan intensitas matahari minimal sesuai dengan yang dipersyaratkan pada standar kondisi pengujian. selama pengujian berlangsung, dilakukan pengukuran beberapa parameter, diantaranya intensitas matahari, kecepatan angin, temperatur udara sekitar, dan temperatur fluida yang dipanaskan. flowchart prosedur pengujian ditunjukkan pada gambar 4. e. analisis hasil pengujian analisis hasil pengujian dilakukan untuk mendapatkan performa dari sistem solar collector. perhitungan diawali dengan menghitung daya output, kemudian menghitung daya input dan yang terakhir menghitung efisiensi sistem. daya output yang dihasilkan dari pengujian dihitung dengan menggunakan persamaan berikut ini [8]: 𝑄𝑄𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 = 𝐼𝐼 × 𝐴𝐴 (1) dengan qoutput adalah daya output (w), i adalah intensitas matahari (w/m2), dan a adalah luas aperture (m2). ya mulai intensitas matahari > 700 w/m2 collector bersih? tidak ada kebocoran? selesai ya batalkan pengujian, ulangi saat intensitas matahari mencukupi bersihkan collector, perbaiki kebocoran tidak tidak ukur intensitas matahari ukur kecepatan angin periksa kondisi collector nyalakan pompa, periksa kebocoran ukur kecepatan angin ukur intensitas matahari ukur temperatur sekitar ukur temperatur fluida kerja gambar 4. flowchart prosedur pengujian. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 57-64, 2011 p-issn 2087-3379 61 daya yang dapat ditangkap dari energi matahari pada solar collector dihitung dengan persamaan umum berikut [9]: 𝑄𝑄𝑖𝑖𝑖𝑖𝑜𝑜𝑜𝑜𝑜𝑜 = 𝜌𝜌𝑓𝑓𝑉𝑉𝑓𝑓𝐶𝐶𝑜𝑜𝑓𝑓∆𝑇𝑇 𝑜𝑜 (2) dengan qinput adalah panas input (w), ρf adalah densitas fluida (kg/m3), vf adalah volume fluida (m3), cpf adalah panas spesifik fluida (j/kg °c), δt adalah perbedaan temperatur (°c), dan t adalah waktu pengujian (detik). efisiensi sistem solar collector dihasilkan dari rasio antara panas input dan outputnya seperti ditunjukkan pada persamaan berikut ini. 𝜂𝜂 = 𝑄𝑄𝑖𝑖𝑖𝑖𝑜𝑜𝑜𝑜𝑜𝑜 𝑄𝑄𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 (3) dengan η adalah efisiensi, sedangkan qinput dan qoutput diperoleh dari persamaan (1) dan (2). iv. hasil dan pembahasan hasil pengukuran yang ditunjukkan pada tabel 2 memberikan nilai temperatur udara, kecepatan udara, intensitas matahari dan temperatur fluida. pengujian parabolic trough solar collector menggunakan palm oil sebagai fluida kerja yang dilakukan mulai pukul 9:20 wib sampai dengan pukul 11:30 wib dengan selang waktu pengambilan adalah 5 menit. volume fluida adalah 37,7 liter serta luas aperture sebesar 12 m2. data pengujian solar collector yang ditunjukkan pada tabel 2 merupakan data yang diambil di lapangan saat dilakukan pengujian yang berfungsi untuk menentukan nilai efisiensi kerja dari model solar collector. hasil pengukuran/ pengujian pada tabel 2 ditunjukkan dalam bentuk grafik pada gambar 5, gambar 6 dan gambar 7. tabel 2. data hasil pengujian solar collector. no waktu (menit) temperatur udara (oc) kecepatan udara (m/s) intensitas matahari (w/m2) temperatur fluida (oc) 1 09:20 27,1 0,00 969 27,2 2 09:25 27,4 1,44 969 34,1 3 09:30 28,3 1,24 956 40,9 4 09:35 26,7 2,74 966 44,9 5 09:40 26,8 2,40 971 51,1 6 09:45 26,1 2,99 983 60,3 7 09:50 26,1 2,97 969 66,4 8 09:55 27,5 1,87 997 74,7 9 10:00 26,1 1,93 1007 80,4 10 10:05 27,4 1,37 1015 85,8 11 10:10 27,8 2,29 1006 90,0 12 10:15 28,0 0,00 1006 94,0 13 10:20 27,7 1,70 1007 97,0 14 10:25 28,7 0,00 975 99,5 15 10:30 28,7 1,89 987 100,6 16 10:35 29,5 0,75 967 103,1 17 10:40 29,5 1,63 951 103,7 18 10:45 29,3 0,53 950 106,1 19 10:50 30,3 0,80 900 106,2 20 10:55 29,5 1,85 935 106,2 21 11:00 30,1 0,53 922 106,3 22 11:05 29,7 0,61 940 105,7 23 11:10 31,2 0,71 931 105,4 24 11:15 32,0 1,08 883 105,0 25 11:20 31,3 3,58 851 104,6 26 11:25 31,1 1,60 888 104,7 27 11:30 30,6 1,83 919 104,7 uji coba awal parabolic trough solar collector (ghalya pikra, a. salim, a.j. purwanto, z. eddy) jmev 02 (2011) 57-64 62 grafik hubungan temperatur fluida terhadap waktu yang ditunjukkan pada gambar 5 menunjukkan bahwa temperatur meningkat seiring dengan semakin lamanya dilakukan pengujian dan kondisi cuaca yang semakin panas. gambar 6 dan gambar 7 yang menunjukkan grafik kecepatan udara terhadap waktu dan grafik intensitas matahari terhadap waktu berfluktuasi selama dilakukannya pengujian. hal ini terjadi karena kondisi cuaca yang berubah-ubah serta kecepatan angin yang mempengaruhi terjadinya fluktuasi pada nilai intensitas matahari yang terukur. intensitas matahari tertinggi yang dapat dicapai adalah 1.015 w/m2. namun semua nilai intensitas matahari terukur memiliki nilai di atas 700 w/m2 sehingga masih layak untuk dilakukan pengujian. analisis dari pengujian yang telah dilakukan dengan menggunakan fluida palm oil selama 2 jam 10 menit memberikan nilai kalor output dan input masing-masing 11,5 kw dan 0,64 kw, dan efisiensi kerja sebesar 5,6%. nilai efisiensi kerja ini belum maksimal karena fluida kerja (palm oil) saat pengujian mengandung air sehingga energi pemanasan banyak digunakan untuk penguapan air yang ada di dalam fluida tersebut yang besarnya tidak diukur. penguapan air yang terjadi membuat kehilangan energi yang besar sehingga menyebabkan rendahnya efisiensi kerja. oleh karena itu perlu dilakukan pengujian kembali dengan terlebih dahulu memanaskan fluida kerja di dalam thermal storage sebelum disirkulasikan hingga kandungan airnya hilang. gambar 5. grafik temperatur terhadap waktu. gambar 6. grafik kecepatan udara terhadap waktu. 0 30 60 90 120 0 20 40 60 80 100 120 140 te m pe ra tu r ( °c ) waktu (menit) temperatur vs waktu tudara 0 1 2 3 4 0 20 40 60 80 100 120 140 ke ce pa ta n u da ra (m /s ) waktu (menit) kecepatan udara vs waktu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 57-64, 2011 p-issn 2087-3379 63 gambar 7. grafik intensitas matahari terhadap waktu. v. kesimpulan pengujian yang dilakukan selama 2 jam 10 menit pada pukul 9:20 sampai dengan pukul 11:30 dengan interval waktu 5 menit menghasilkan kalor output dan input sebesar 11,5 kw dan 0,64 kw serta efisiensi 5,6%. pengujian perlu dilakukan kembali untuk memperbaiki performa dengan cara menghilangkan kandungan air yang terdapat di dalam fluida kerja (palm oil) sehingga nilai efisiensi kerja lebih optimal. ucapan terima kasih terima kasih disampaikan kepada kepala pusat penelitian tenaga listrik dan mekatronik – lembaga ilmu pengetahuan indonesia yang telah memfasilitasi penelitian ini dengan sumber dana dipa tahun 2011, dan kepada berbagai pihak yang telah membantu dalam penulisan makalah ini. daftar pustaka [1] r. aringhoff, g. brakmann, m. geyer, s. teske, concentrated solar thermal powernow. greenpeace: estia-iea solarpaces, 2005. [2] k.s. reddy, g.v. satyanarayana, "numerical study of porous finned receiver for solar parabolic trough concentrator," engineering applications of computational fluid mechanics, volume 2, nomor 2, pp. 172-184, 2008. [3] p.f. ruiz, european research on concentrated solar thermal energy. luxemburg: european communities, 2004. [4] j.a. duffie, w.a beckman, solar engineering of thermal processes. 3rd ed. united states of america: john wiley & sons, inc., 2006. [5] s. quoilin, experimental study and modeling of a low temperature rankine cycle for small scale cogeneration. belgia: thesis electro-mechanical engineer, university of liege, faculty of applied sciences, aerospace and mechanical engineering department thermodynamics laboratory, 2007. [6] s. quoilin, v. lemort, "technological and economical survey of organic rankine cycle systems," in proceeding of 5th european conference economic and management of energy in industry, belgia, portugal, 2009. [7] european committee for standardization, "thermal solar systems and components solar collector part 2: test methods," british standard, london, uk, bs en 12975-2:2006, 2006. [8] m. qu, d.h. archer, s.v. masson, "a linear parabolic trough solar collector performance model," in proceeding of icebo international conference for enhanced building operations: renewable energy resources and a greener future, volume viii-3, nomor 3, 2006. [9] f.p. incropera, d.p. dewitt, fundamentals of heat and mass transfer. 6th ed. united states of america: john wiley & sons, inc., 2007. [10] h.m. steinhagen, solar thermal power plants – on the way to commercial market introduction. almeria/spain: institute for 840 880 920 960 1000 1040 0 20 40 60 80 100 120 140 in te ns it as m at ah ar i ( w /m 2) waktu (menit) intensitas matahari vs waktu uji coba awal parabolic trough solar collector (ghalya pikra, a. salim, a.j. purwanto, z. eddy) jmev 02 (2011) 57-64 64 technical thermodynamics, german aerospace centre (dlr), stuttgard – cologne, 2008. [11] n. castaneda, j. vazquez, m. domingo, a. fernandez, j. leon, sener parabolic trough collector design and testing. france: solarpaces, 2006. [12] p. cameron, g. crompton, solar power plant pre-feasibility study. brisbane, australia: actew agl and act government, 2008. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 79-84, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.79-84 machine vision implementation in rapid pcb prototyping implementasi machine vision pada pembuatan duplikasi pcb yosafat surya murijanto, rusman rusyadi, maralo sinaga department of mechatronics, faculty of engineering swiss german university, bumi serpong damai banten 15321, indonesia yosafat. murijanto@student.sgu.ac.id; rusman.rusyadi@gmail.com; maralo.sinaga@sgu.ac.id recieved: august 24th, 2011; revised: october 27th, 2011; accepted: december 1st, 2011; published online: december 22th, 2011. abstrak pemrosesan image yang merupakan inti dari machine vision telah membuktikan dirinya menjadi bagian yang penting pada industri saat ini. penerapan pemrosesan image telah membuka pintu yang baru dalam proses manufaktur yang lebih baik. karya tulis ini memaparkan penerapan machine vision dalam proses desain modul yang mampu mengekstrak lubang bor dan mengarahkan jalur koordinat pcb dari kondisi yang belum tersusun menjadi jalur koordinat yang tersusun. algoritma ini dimulai dengan proses pre-capturing, diikuti dengan segmentasi image dan pemfilteran, deteksi sisi dan kontur, ekstraksi koordinat dan diakhiri dengan pembuatan g-code. library yang ada di opencv dan qt ide merupakan perangkat utama yang dipergunakan. melalui beberapa percobaan yang dilakukan, disimpulkan bahwa algoritma ini mampu memberikan hasil yang cukup baik. algoritma pengeboran dan ekstraksi jalur menghasilkan rata-rata 90% dan 82% dari jumlah lubang bor dan jalur yang ada pada pcb yang discan dalam total waktu pemrosesan kurang dari 3 detik. hal ini dapat dicapai pada kondisi pencahayaan yang baik, permukaan pcb yang baik, dan webcam yang berkualitas baik. kata kunci: pcb scanning, ekstraksi koordinat, g-code, machine-vision. abstract image processing, the heart of machine vision, has proven itself to be an essential part of the industries today. its application has opened new doorways, making more concepts in manufacturing processes viable. this paper presents an application of machine vision in designing a module with the ability to extract drills and route coordinates from an un-mounted or mounted printed circuit board (pcb). the algorithm comprises pre-capturing processes, image segmentation and filtering, edge and contour detection, coordinate extraction, and g-code creation. opencv libraries and qt ide are the main tools used. throughout some testing and experiments, it is concluded that the algorithm is able to deliver acceptable results. the drilling and routing coordinate extraction algorithm can extract in average 90% and 82% of the whole drills and routes available on the scanned pcb in a total processing time of less than 3 seconds. this is achievable through proper lighting condition, good pcb surface condition and goodwebcam quality. keywords: pcb scanning, coordinate extraction, g-code, machine vision. i. introduction this paper mainly focuses on the application of vision in manufacturing processes. the concept was born from the reverse engineering concept suggested by koivunen [1], in which she stated that integrating reverse engineering and computer vision will benefit manufacturing processes in many ways. in this case, vision is used to generate design data of an existing printed circuit board (pcb). the data is then further processed to form a computer aided design (cad) model and other manufacturing information, before finally a prototype of the scanned component is built in a manufacturing cell. g-code acts as the cad model mentioned previously. the concept will greatly decrease design time and at the end could save much manufacturing cost. ii. methodology a. creating proper lighting condition martin [2] uttered that “the quality and appropriateness of lighting are critical aspects for creating a robust vision inspection”. two lighting modules were constructed: back light to support drilling coordinate extraction (un-mounted pcb case) and front light to support routing coordinate extraction. based on figure 1 which is shows a comparison of common machine vision lighting, sources led arrays was chosen as the lighting source of these lighting modules due to its http://dx.doi.org/10.14203/j.mev.2011.v2.79-84 machine vision implementation in rapid pcb prototyping (yosafat surya murijanto, r. rusyadi, m. sinaga) jmev 02 (2011) 79-84 80 figure 1. comparison of common machine vision lighting sources [2]. superiority to other light sources: stability, flexibility, lifetime, and cost effectiveness (low power consumption). lighting techniques can be classified as bright field (on-axis lighting), partial bright field (directional lighting) and dark field (off-axis lighting). each has its own application field and further categorized as direct and diffuse lighting. figure 2 groups lighting techniques according to their application fields. the application focuses on scanning pcbs, a surface with relatively uneven topology and mixed surface reflectivity, and thus bright and dark field lighting can be applied in the front light. however, bright field is chosen because of its better capability in generating contrast and enhancing topographic details [2]. when dealing with metals, however, bright field may create glares on the metal surface. this could result in incorrect contour extraction and at the end, false coordinate extraction. this problem can be reduced by applying a diffuser in our front light module [3]. back lighting provides excellent image contrast as it produces silhouettes of the image against the bright background [2]. this is used to expose pcb edges and drill holes. the back light design can be observed in the figure 3. b. image preparation image preparation will consist three operations. those operations are color conversion, smoothing and edge detection described as follow. 1) color conversion each frame grabbed by the webcam is stored as an red, green and blue (rgb) image. this is of course useful if it is used for visual inspection by humans, but not for image processing done by computers [4]. rgb image stores the value of each pixel in 3 channels and in many cases computers are only able to process operation in 1 channel at a time. processing 3 channel images could take too much time and consume too much memory. therefore rgb image has to be converted to grayscale image, which represents major features of the rgb image in a single channel. 2) smoothing smoothing (or blurring) is done to remove unwanted camera artifact or noises [5]. the simplest burring technique is applied by replacing a pixel value with the average of its surrounding neighbor-pixels. 3) edge detection edge detection is the base of contour extraction operation, which is the main algorithm of drilling and routing coordinate extraction. a method developed by j. canny is applied. this technique takes the first and second derivatives of intensity of an image pixel, as shown in figure 4. an edge is defined if the second derivative result is zero and the first derivative result is above the defined threshold. c. routing coordinate extraction the objective of developing this algorithm is the ability to extract lines from a complex image (pcb image). to do so, contour extraction and polygon approximation techniques are applied. figure 2. lighting techniques application fields [2]. figure 3. back light design. frame led engraved acrylic journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 79-84, 2011 p-issn 2087-3379 81 figure 4. canny edge detection concept [5]. a contour is a list of points that represent a curve in an image [5]. the contour extraction algorithm comprises component labeling and assembling. component labeling differentiates holes from contours. then these found contours are assembled according to the defined method. this module will assemble the contours as trees. polygons are the approximated from these contours. this is done to ensure that the extracted points form a close-loop and to filter the results from excessive points caused by image noises. first, a line is drawn from two extreme points of the contours. a farthest point of the contour, measured from that line, is then defined and lines are drawn to connect the newly-defined point with the existing points. this continues until the length of each line exceeds the defined precision parameter. figure 5 illustrates the polygon approximation. d. drilling coordinate extraction the challenge of developing the drilling coordinate extraction is to be able to detect small and imperfect circles. to meet this requirement, two main algorithms were applied: hough [6] and thresholding-based circle detection. hough circle is based on edge detection and first-order sobel derivative. it provides more practical way of detecting the drill holes. the center coordinate figure 5. polygon approximation [5]. of the circles is also directly returned. however ,the algorithm is very prone to noises. the thresholding-based circle detection integrates tophat image morphology, basic thresholding, contour extraction and polygon approximation. tophat algorithm is applied according to equation (1). the input image is subtracted by the opened image. the opened image itself is done by first eroding and then dilating the image. figure 6 illustrates the tophat image morphology. the result of the tophat image morphology is then thresholded and.dilated once again; this will reveal the drill holes. finally, contour extraction and polygon approximation are applied and the drilling coordinates can be extracted. the advantage of this algorithm is the ability to preserve edges even on glare area or in case uneven reflection exists. however, the time needed to complete the operation highly depends on the number of circles to be detected. tophat(src) = src – open(src) (1) e. generating g-code the communication between systems should use standardized data formats [1]. for this reason, g-code file creation is chosen as the final step of the main program. after the coordinates are extracted, they are masked to form standardized g-code based on rs274d and din 66025 [7]. to be manufacturable, the g-code should include the drilling and routing coordinates and the drilling and engraving parameters, including spindle speed, feed rate and depth of cut. the g-code creation utilizes qplain text edit class provided by qt. machine vision implementation in rapid pcb prototyping (yosafat surya murijanto, r. rusyadi, m. sinaga) jmev 02 (2011) 79-84 82 figure 6. tophat image morphology [5]. iii. results and discussion a. routing coordinate extraction the routing coordinate extraction was tested using a simple “s curve” image and 4 pcb types.the result shows that it is able to detect in average more than 80% of all routes. as mentioned in the previous section, the algorithm highly depends on edge detection. however the edge detection failed in some cases. this is due to the uneven contrast and reflection caused by the front light module. if the input is an “ideal” image, the algorithm will perform perfectly, this can be seen as it was tested using a simple binary image. evaluating the processing time, the algorithm managed to detect and process 1698 contours in 828ms time. the test conclusion can be observed in table 1 and the routing coordinate extraction result can be seen in figure 7. b. drilling coordinate extraction the detections using hough circle and thresholding-based circle are discussed as follow. 1) hough circle hough circle offers easy and practical way of detecting drill holes. however this algorithm delivers poor performance as it is applied in this case. the algorithm is based on sobel operation, which is rather sensitive to noises. setting the threshold values too high would eliminate most drill holes, but setting it too low would result in so much noises and false circle detection. this algorithm was only able to detect 13 out of 842 correct holes 2) thresholding-based circle detection this algorithm performs much better compared to the hough circle. the holes in the glare area can also be really preserved due to the tophat algorithm. though there are some problems around the glared and shadowed area, the result is still acceptable. the algorithm managed to detect 817 out of 842 holes on the matrix pcb. the test conclusion can be observed in table 2 and the drilling coordinate extraction result can be seen in the figure 8. c. g-code generation after doing some observations and testing of the generated g-code, it can be seen that the algorithm delivers precise result. the test was done by manufacturing a simple pcb from a generated g-code. the result showed that every line can be executed correctly. the unit used in the g-code is mm as a result of applying g71 in the code. an example of generated g-code that shows the drilling operation can be observed in the figure 9. figure 7.routing coordinate extraction result. figure 8. drilling coordinate extraction result. (the rectangles show improper drill detection). journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 79-84, 2011 p-issn 2087-3379 83 table 1. routing coordinate extraction performance. sbi spcba spcb b dpcb mpcb processed image size (pixels) 242 x 336 341 x 296 339 x 249 162 x 172 561 x 271 detected raw contours 1 248 475 78 1698 detected routes 1 23 34 47 227 detected routes –approx. 100% 70% 95% 100% 45% processing time (ms) 78 265 438 156 828 note: sbi: simple binary image; spcb-a: single layer pcb a; spcb-b: single layer pcb b; dpcb: double layer pcb; mpcb: matrix pcb. table 2. overall drilling coordinate extraction performance. hough circle basic thresholding tophat + thresholding detected circles 15 757 817 correct holes 13 627 757 error 98.46% 25.53% 10.10% processing time (ms) 438 16 140 figure 9. generated g-code example. iv. conclusion and recommendation the project managed to integrate vision sensor in reverse engineering process through the pcb scanning module. it is able to extract in average 80% of all routes and 90% of all drill holes of a pcb in less than 3s time. it is also able to output manufacturable g-code as the cam data. to perfect the module, the front light can be changed into dome or coaxial lighting, which will eliminate glares and uneven reflection. computer graphic techniques such as path refining, line approximation and circle approximation can also be applied to output better engraving movement. finally, a component library can be added to the database to improve the drilling coordinate extraction accuracy. this component library should comprise the basic components, especially standard integrated circuits (ics). references [1] visa koivunen and ruzena bajcsy, (1992, aug.). rapid prototyping using threedimensional computer vision. scholarly commons. [online]. available: http://repository.upenn.edu/cgi/viewcontent. cgi?article=1496&context=cis_reports&seiredir=1#search=%22machine+vision+rapid+ prototyping%22 [accessed: november 4, 2011] [2] daryl martin, a practical guide to machine vision lighting. rochester, vt: advanced illumination, october 2007. [3] cvi melles griot, “machine vision lighting fundamentals,” in fundamentals of imaging and machine vision. cvi melles griot 2009 technical guide, volume 2, issue 1. pp. 3. 2009. [4] g. bradski, open source computer vision library in robotics, new jersey: prentice hall, 2004. [5] bradski, g. and kaehler, a., “learning opencv”, 1st ed., ca: o’reily media inc., 2008. [6] brovička, j., “coms30121 – image processing and computer vision,” circle detection using hough transform documentation, march 2003. [7] power automation america, inc., “standard list of cnc codes.” machine mate inc. [online]. available: http://www.machinemate.com/standardcod es.htm [acessed: november 4, 2011] [8] y. murijanto, machine vision implementation in rapid pcb prototyping. thesis report, swiss german university, bsdcity, tangerang, indonesia, july 2011 machine vision implementation in rapid pcb prototyping (yosafat surya murijanto, r. rusyadi, m. sinaga) jmev 02 (2011) 79-84 84 [9] d.a. forsyth, & j. ponce. computer vision: a modern approach. nj: prentice hall, 2003. [10] t.q. chen, j.x. zhang, y.n. zhou, and y.l. murphey. a smart machine vision system for pcb inspection. university of michigan, 2000. j. mechatron. electr. power veh. technol 06 (2015) 49–56 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.49-56 economic valuation of hypothetical paratransit retrofitting naili huda a, *, kim peter hassall b , sunarto kaleg a , abdul hapid a a research centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu/sangkuriang, bandung 40135, indonesia b department of infrastructure engineering, the university of melbourne level 02 room c201 engineering block c, parkville 3010, australia received 17 october 2013; received in revised form 05 january 2015; accepted 07 january 2015 published online 30 july 2015 abstract this paper describes a feasibility analysis of conventional and retrofitted paratransits, comparing economic performance of conventional paratransit with those using lead acid and lithium batteries. research object is dago-kalapa paratransit in bandung, west java, travelling the distance of 11 km in town, under 8 peak hour operation. after calculating the estimated annual cost and benefit; net present value (npv), payback period (pbp), and internal rate of return (irr) then were quantified to provide feasibility description of those three paratransits. in addition, a sensitivity analysis regarding discount rate, gasoline price, and battery price is given to offer broader sense of factors embraced. it is found that both gasoline and lead acid paratransit have big npvs with only slight differences, while lithium paratransit has negative npv. this phenomenon applies to their pbps and irrs as well. only when gasoline costs reaches idr 15,000 will electric paratransit prevails over conventional one. thus, it can be inferred that at the moment, paratransit runs with gasoline is still the most cost effective compared to its counterparts. however, starting retrofitting from now is endorsed due to its environmental benefit. keywords: feasibility; paratransit; conventional; electric; bandung; indonesia. i. introduction paratransit, or usually called ‘angkot’ by locals, is the most common means of urban transport in indonesia. paratransit armada is mostly possessed by private individuals [1], and run on determined routes but not determined schedule [2]. paratransit provides ease of access while on the other hand, generates high emission [3]. emission comes from the fossil fuel used by the paratransit. this condition is coupled by the fact that paratransit fleet mainly consists of old vehicles, resulting in poor exhaust system of the vehicles. beside emission, some noted public outcries associated to public image of paratransit include traffic jam [3], traffic accidents, and its low quality of service. in bandung and in most indonesia’s cities and towns, paratransit is the main medium of commuting [4]. though not always 24 hours available to serve the commuters, paratransit’s departures during the day are quite frequent [5]. moreover, it offers relatively cheaper fare compared to other transportation methods. fare is set based on distance. passengers pay directly to the driver rather than using ticket. since price is the main consideration factor for customers to decide which public transport they would like to use [6], paratransit market is always available. paratransit by far is community’s favorite choice. to tell apart one route from another, paratransits are differentiated by colors, and in some locations, numbers. using vans or minibus, its capacity ranges from twelve to fourteen passengers, driver not counted. at peak hours, paratransit can load up to twenty two passengers per return and only five during off peak hours [1]. many ideas have been proposed to improve bandung’s paratransit condition. some studies propose rerouting, new pools for paratransit, and paratransit reduction to eliminate traffic jam; and others recommend the use of renewable energy to substitute fossil fuel as an effort to suppress air pollution [1, 4-7]. this paper will only discuss the economic viability of paratransit retrofitting as an endeavor to reduce fossil fuel usage and minimize pollution by applying alternative energy to fuel paratransit. in the national level it *corresponding author. tel: +62-22-2503055 e-mail: vedderforeva@yahoo.com n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 50 complies with presidential decree number 5/2006 which states that in 2025 oil consumption should be only 20% in indonesian total energy mix [8]. in the meantime, electric vehicle is gaining popularity as a transportation device that emits a very low level of emission, if not zero [9]. when generated from renewable energy, electricity offers bigger benefit as fuel, even when compared to direct use of biomass [10] and cng [11]. many suggested that if applied as mass transport, electric vehicle will generate significant reduction of local and global emission, not to mention oil usage, traffic noise, and traffic jam [12]. nevertheless, due to the current battery capacity, distance range will be narrow. consequently to date, electric vehicles are more suitable for everyday travel and city commuting [12]. studies [12-15] have been done to compare performance of gasoline and electric vehicles. most of them emphasize the benefit of electric vehicle over gasoline cars in term of minimizing pollution and vehicle operational cost. therefore, exploring electric vehicle for future application would be beneficial. continual and thorough study should be done to endorse implementation as well as creating capacity building and public awareness. in indonesia researches on electric vehicle have been done by several research institutions and industry. as seen in local media, some research products and prototype of electric vehicle have been made by public. this paper will elaborate the economic feasibility of converting the conventional paratransit into electric. there are two electric paratransits that are about to be investigated, one uses lead acid battery and the other uses lithium. lead acid is deemed obsolete at this time, nonetheless considering its modest price and some improvements made related to resistance, weight and cost [16], the possibility of its application still exists. lithium is included to provide the ideal condition of electric paratransit. the type of lithium battery investigated for this study is lithium iron phosphate (lifepo4). due to its advantages over lead acid in terms of weight, size, and capacity, lithium is more widely used for current electric and hybrid vehicles available in the global automobile market. paratransit is elected for this study for some basis. paratransit is a popular public transport and available in massive amount. moreover, it operates almost all day, therefore using large amount of gasoline which is the core of our energy and pollution problem. most importantly, paratransit business is very open to government interference. for those reasons, it is expected that if paratransit electrification plan is executed, reduction of emission and fossil fuel usage would be massive and the benefit would be clear. ii. methodology figure 1 explains steps done in this research. for studying the feasibility of retrofitted paratransit, the cost needed to alter conventional paratransit into electric paratransit using lead acid and lithium battery is quantified. cost covers the retrofitting cost plus operation and maintenance cost. retrofitting cost incorporates price of vehicles, batteries and retrofitting workshop. operation and maintenance cost comprises of gasoline price, charging cost, and common maintenance cost. after daily operation cost was calculated and aggregated to ten years, net present value (npv), internal rate of return (irr), and payback period (pbp) then were counted. below is formula for npv: npv (i) = 𝑅𝑡 (1+𝑖)𝑡 𝑁 𝑡=0 (1) where t represents number of calculation years, which in this case is 10; i is discount rate and rt is cash flow of annual revenue and disbursement. irr can be determined using extrapolation to find in what exact discount rate npv would be zero. furthermore, payback period is counted by dividing the initial capital with annual profit in present value. all calculations were executed using built in formulas based on equation above in ms excel. end result is presented in table 1. npv is in idr, irr is in % and payback period is in year. the calculation was done by presuming 8% of roughly estimated inflation, averaged from year 2000-2013 inflation data from badan pusat figure 1. research methodology quantifying prices of conventional and retrofitted paratransits estimating annual operational and maintenance cost, and benefit performing cost and benefit analysis determining npv, irr, and pbp n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 51 statistik [17], 10 years vehicle useful life according to bandung mayor decree 2002/1714 [18], and 13% discount rate following loan interest rate of bank bni (pt bank negara indonesia) [19], an indonesian leading national bank. it is further assumed that paratransit operates 30 days per month, 10 months per year considering some days off that usually employed by paratransit owners spent on overhaul, repairing and mere holidays. npv, irr, and pbp were computed to gain economic parameters to evaluating the financial performance of those three paratransit. as widely known, npv, irr, and pbp are the most common ways to assess the performance of future investment. please note that some data and calculations will not be revealed in this paper. please contact the author when you need one. calculation basis are as follows: • working hours per day = 8, working days per month = 30, working days per year = 300. • kalapa dago paratransit fare is assumed idr 5,000 fixed. as authors could not get the valid established fare from the authorities, fare is inferred from articles [20] and [21]. • price of gasoline is idr 6,500, needed gasoline per 4 hour operation = 10 liters. • maintenance cost is calculated in accordance with keputusan direktur jenderal perhubungan darat sk. 687/aj.206/drjd/2002 for conventional paratransit and adjusted for retrofitted paratransit. • vehicle used is mitsubishi colt t120ss 1300 cc and the same mpi 1.5 l for conventional paratransit, price of new vehicle is about idr 90,000,000. • assumed resale value of 10 year vehicle = idr 30,000,000. • electric motor used is fbi-4001 144 v. • distance that can be travel with such vehicle weight and 50% state of charge battery per charge ≈ 51 km. • battery replacement is done per year considering the available cycles of the batteries. for lead acid: • lead acid battery used is ns2200 6 v 220 ah produced by pt nipress tbk., weighted 25 kg each cell, hence 24 cells per vehicle with total weight of 600 kg. • battery replacement price = idr 36,000,000. • assumed battery resale value = idr 2,640,000. • price for retrofitted paratransit using lead acid = idr 202.41, assumed resale value = idr 6,000,000. • energy needed to charge using 25 a charger is 3.6 kva. in pln (indonesian state electricity company) tariff list, this falls into cluster 4 for industry (3,500 va – 14 kva) [22], idr 1,112 per kwh. • energy to charge one electric paratransit per day = 3.6 kva x 3.667 hours = 13.201 kwh. • cost per charge = 13.201 kwh x idr 1,112 per kwh = idr 14,679.51 bringing monthly charging cost of idr 14,679.51 x 30 = idr 440,385.36. for lithium ion: • lithium battery used is 3.2 v 220 ah. for 144 v, total cells used are 45. • battery replacement price = idr 225,720,000. • assumed battery resale value = resale of lead acid battery = idr 2,640,000. actually the predicted salvage value of lithium battery can be higher or lower than that of lead acid, depending on valuable components it still has at the end of its economic life [23]. for this study however, the salvage values are assumed similar. • price for retrofitted paratransit using lithium ion idr 392.13, assumed resale value = idr 6,000,000. • energy needed to charge using 60 a charger is 8,640 va. in pln (indonesian state electricity company) tariff list, this falls into cluster 4 for industry (3,500 va – 14 kva) [22], idr 1,112 per kwh. • energy to charge one electric paratransit per day = 8.64 kva x 1.833 hours = 15.837 kwh. • cost per charge = 15.837 kwh x idr 1,112 per kwh = idr 17,610.74 bringing monthly charging cost of idr 17,610.74 x 30 = idr 528,322.32. iii. result and discussion using the above assumptions and data, economic performance valuation of three paratransit schemes has been done. result is shown in table 1. npv is in idr and payback period in years. it can be seen that conventional paratransit has the best performance of all. lead acid paratransit comes after and retrofitted paratransit with lithium is the worst. lithium has negative npv since the cost it bears is ultimately high. majority of lithium paratransit cost is generated from battery replacement. cost of one replacement is more than idr 200,000,000. since replacement must be done once a year due n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 52 to battery cycle, annual cost of operation becomes large. while income gained from daily operation cannot compete with the escalating disbursement, lithium cash flow eventually produces minus npv. therefore, irr and payback period for paratransit with lithium battery cannot be counted due to its very big accumulation of annual disbursements. conventional paratransit has big npv because the income is far bigger than the annual cost which comes mostly from gasoline consumption. to test the effect of some factors incorporated in the feasibility calculation, table 2 to table 9 below consecutively show sensitivity analysis concerning gasoline price, discount rate applied, battery price discount, and paratransit fare increase. table 2 and 3 list the new values of npv, irr, and payback period of those three paratransits due to change on gasoline price. it can be seen that npvs of lithium paratransit are still negative. however, paratransit with lead acid battery outweighs paratransit with gasoline when gasoline price is at least idr 13,500, an increase of more than 200% from current price which is idr 6,500. this happens because when gasoline price escalates, operational cost of the conventional paratransit automatically escalates resulting in lower annual cash flow as on the other hand, revenue does not increase. in regard with revenue upsurge, when fare is increased to idr 7,000 and idr 10,000 from idr 5,000 at the moment, as can be seen in table 4 and 5, there is no significant improvement to the financial performance of electric paratransit. yet in the real world, when condition is still in status quo, increasing fare that much is unlikely to happen. furthermore, when discount is reduced to become 5% and enlarged to become 20% from the previous 13% as described in table 6 and 7, no crucial improvement takes place in term of lead acid and lithium feasibility. both electric paratransit still cannot overcome the conventional paratransit. these same conditions are also applied to battery price cut in table 8 and 9. even though battery price is reduced with 50% and 60% markdown for lead acid and lithium, conventional paratransit still wins the race. nevertheless, it is good to note that the bigger the markdown, the better the financial performance of electric paratransit will be. npv of lithium paratransit is better albeit the value still does not make lithium paratransit feasible. likewise, lead acid performance also gets better. in contrast, performance of conventional paratransit remains the same since it is not affected by battery price. it should be noted that price reduction will only apply for bulk buy. therefore, as long as retrofit is done solely, price reduction would be hard to get. table 1. estimated financial performance of three kinds of paratransit scenario paratransit types lead acid conventional lithium ion npv 296,026,974.43 407,056,330.83 -1,090,727,925.02 irr 44.09% 90.81% payback period 2.27 1.10 table 2. feasibility when gasoline price is idr 13,000 scenario paratransit types lead acid conventional lithium ion npv 228,495,089.12 123,010,209.27 -979,356,140.28 irr 40.24% 42.10% payback period 2.49 2.38 table 3. feasibility when gasoline price is idr 13,500 scenario paratransit types lead acid conventional lithium ion npv 228,495,089.12 106,563,427.48 -979,356,140.28 irr 40.24% 38.48% payback period 2.49 2.60 n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 53 lithium actually has a number of advantages over lead acid. it has lighter weight and higher energy density than lead acid [24-29], isastia even mentions that lead acid’s energy density and specific energy is one fourth of lithium’s [30]. other studies find that lead acid’s lifetime is far shorter, moreover, it is easier to get and the most attractive factor is that it is cheaper than lithium [30-35]. this makes cost of ownership for lithium then is higher to at least twice than that of lead acid. lithium on the other hand, has serious protection risk and more expensive [26], [36] despite the fact that it is the most promising battery available for electric vehicle [37]. lead acid technology is mature, the battery has been marketed for over 100 years [38] although at the moment lithium is the most sought for electric vehicle [39]. nevertheless, even though it is widely applied for electric vehicle at the beginning of ev development, lead acid’s range is shorter and its performance is poorer than lithium’s [37], [40]. lead acid cheap price and mature technology trades off its low energy density [35]. amount of energy produced, weight, life time, charging time, distance per unit energy, and other aspects. weinert states whereas both kind of batteries will develop in the future, for the time being, taken into account the performance of lithium batteries, the cost of ownership is very high [36], hence shifting to lithium from lead acid is not recommended from financial perspective. the weakness of this study is that passenger quantification is based on busy hours, where number of passenger is assumed as 22 per return or paratransit seats are full. while in fact number of passengers is not always that big. however, although this income seems too optimistic, even when we assume it as half of the current income, the npv value is still positive; hence this investment is feasible to execute. this applies for lead acid case as well. this scenario seems to support the existing mode of paratransit and does not endorse the electrification or paratransit. however, when looking into the real matter, both conventional and lead acid options actually are table 4. feasibility when paratransit fare is idr 7,000 scenario paratransit types lead acid conventional lithium ion npv 517,958,448.68 626,281,732.14 -689,892,780.72 irr 69.98% 146.26% payback period 1.43 0.68 table 5. feasibility when paratransit fare is idr 10,000 scenario paratransit types lead acid conventional lithium ion npv 952,153,488.02 1,060,476,771.49 -225,697,741.38 irr 112.85% 234.82% payback period 0.89 0.43 table 6. feasibility when discount rate applied is 5% scenario paratransit types lead acid conventional lithium ion npv 438,413,673.21 569,929,949.43 -1,366,621,194.63 irr 40.24% 86.99% payback period 2.49 1.15 table 7. feasibility when discount rate applied is 20% scenario paratransit types lead acid conventional lithium ion npv 126,132,602.85 221,934,367.37 -777,157,979.31 irr 40.24% 86.99% payback period 2.49 1.15 n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 54 profitable, thus supporting electrification using lead acid is good to be considered. their npv are close, lead acid’s payback period is half that of conventional’s, but that does not mean that lead acid is not profitable. for lithium, since its npv is negatively huge, unless there is interference from the donor to settle this value in the ways of providing the battery or probably increasing the paratransit fare to improve its income, it is better to be left off of this discussion. exception can be given when lithium battery replacement price is available below lead acid’s. for starting annual income of idr 132,000,000 from the passenger, the paratransit owner is clearly cannot afford it. not to mention the escalating price in the years to come. fare raise, if exists due to inflation or other enablers, will not be able to compete with the raise of lithium ion battery. on lead acid battery, recycling technologies are available, has been commonly used and more technologies are proposed [41-43]. consequently, when capital cost is ready, there is no stopping in implementing lead acid retrofitting for paratransit. electric vehicle is created to reduce fossil fuel and eradicate emission [44-46]. as a result, although only allows short range, electric vehicle application will provide great benefit compared to conventional vehicle [15], even greater when the electricity used is generated from renewable energy. predicted to have more than 10% growth before 2025 [47], nowadays electric vehicle selling are supported almost everywhere. this fact is supported by some reported enhancements related with electric vehicle, such as battery [11]. all these information opens the possibility of cheaper vehicles in the future, hence wider application of electric vehicle. regarding efforts to advocate the implementation of ev nationally, government involvement is a must. support can be given in the forms of ev purchase incentives, parking fee waiver, special policy to attract investment in ev industry [48], and making available charging infrastructure. however, first step should be to release regulation on ev usage on road. iv. conclusion retrofitting paratransit into electric paratransit using lead acid battery is endorsed, while lithium is not, until the price is competitive. further investigation can be done taken into account reduced price of batteries and motors due to bulk buy. this will provide more benefit since the price will be remarkably cheaper. considering peak and off peak hour would be a plus point as well, since income from the passenger may increase during peak hours. from sensitivity analysis, increase of gasoline price will benefit the application of electric paratransit, particularly lead acid, as they will improve the economic performance of the retrofitted paratransit. finally, based on the financial performance of proposed paratransit electrification, as long as capital is available to support for battery price discount, electric paratransit retrofitting can be executed promptly in indonesia. depart from the discussion presented, this paper hence of its accord recommends government support to facilitate early ev implementation in terms of realizing friendly business climate, releasing policies benefitting future ev industries and ev owners, and providing early establishment of charging facilities. v. references [1] solichin, "the role of route pattern and activity to the operators income at urban public transport in bandung municipal," table 8. feasibility when battery prices are 50% discounted scenario paratransit types lead acid conventional lithium ion npv 327,175,779.88 336,818,372.58 -360,628,209.22 irr 50.63% 86.99% payback period 1.98 1.15 table 9. feasibility when battery prices are 60% discounted scenario paratransit types lead acid conventional lithium ion npv 346,911,918.03 336,818,372.58 -236,882,623.00 irr 52.66% 86.99% payback period 1.90 1.15 n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 55 master, insitute technology bandung, bandung, 2007. [2] t. b. joewono and h. kubota, "user perceptions of private paratransit operation in indonesia," journal of public transportation article, vol. 10, 2008. [3] a. sumaryana. (2009, september). di balik demonstrasi sopir angkot. pikiran rakyat. [online]. available: http://www.pikiranrakyat.com/prprint.php?mib=beritadetailandi d=50038 [4] o. z. tamin, "integrated public and road transport network system for bandung metropolitan area," proceedings of eastern asia society for transportation studies, vol. 5, p. 20, 2005. [5] a. munawar, "sustainable public transport planning in indonesia, case study in yogyakarta and bandung," presented at the the 2007 international conference and annual meeting of chinese institute of transportation challenges and opportunities toward more sustainable transportation, taipei, 2007. [6] t. b. joewono and h. kubota, "exploring public perception of paratransit service using binomial logistic regression," civil engineering dimension, vol. 9, p. 8, march 2007. [7] t. b. joewono and h. kubota, "the characteristics of paratransit and nonmotorized transport in bandung, indonesia," journal of the eastern asia society for transportation studies, vol. 6, p. 16, 2005. [8] k. r. d. t. ri, indonesia 2005-2025 buku putih energi, m. o. r. a. technology, ed., ed. jakarta, 2006, p. 105. [9] s. bickerstaffe. (2009, april) electric dreams. powertrain. 1. [10] b. h. pro, et al., "energy and land use impacts of sustainable transportation scenarios," journal of cleaner production, p. 11, 2005. [11] i. hossain, "lifecycle analysis of different urban transport options for bangladesh," energy policy, p. 10, gurcan gulen. [12] e. a. f. b. e. vehicles, "energy consumption, co2 emissions and other considerations related to battery electric vehicles," european association for battery electric vehicles, 2008. [13] m. werber, et al., "batteries: lower cost than gasoline? ," energy policy, p. 4, 2009. [14] h. mousazadeh, et al., "technical and economical assessment of a multipurpose electric vehicle for farmers," journal of cleaner production, vol. 17, p. 7, 2009. [15] m. a. delucchi and t. e. lipman, "an analysis of the retail and lifecycle cost of battery-powered electric vehicles," transportation research part d, p. 34, 2001. [16] a. ingram. (2012, 5 september). could hybrids use lead-acid batteris? startup says yes. available: http://www.greencarreports.com/news/1081 319_could-hybrids-use-lead-acid-batteriesstartup-says-yes [17] b. p. statistik, "tabel inflasi dan ihk indonesia tahun 2000-2014 menurut bulan," in ms excel, ed. jakarta: badan pusat statistik, 2014. [18] "paratransit driver strike impact, bandung is flooded with motorcycles," in kapanlagi.com, ed, 2009. [19] b. indonesia. (2013, december). suku bunga dasar kredit. available: http://www.bi.go.id/web/id/perbankan/suku +bunga+dasar+kredit/ [20] antarajawabarat.com. (2012, december). bandung's organda ensures there is no tariff increase. available: http://antarajawabarat.com/lihat/berita/3690 2/lihat/kategori/96/hukum [21] metronews.com. (2013, december). paratransit fare in bandung increases more than 30%. available: http://www.metrotvnews.com/metronews/re ad/2013/06/23/6/163400/tarif-angkutan-dibandung-naik-di-atas-30 [22] peraturan menteri no 30 tahun 2012 tarif dasar listrik, m. o. energy, 2012. [23] i. buchmann. (2012, 20 november 2014). bu-705a: battery recycling as a business. battery university. available: http://batteryuniversity.com/learn/article/batt ery_recycling_as_a_business [24] g. j. offer, et al., "comparative analysis of battery electric, hydrogen fuel cell and hybrid vehicles in a future sustainable road transport system," energy policy, vol. 38, pp. 24-29, 2010. [25] j. van mierlo, et al., "which energy source for road transport in the future? a comparison of battery, hybrid and fuel cell vehicles," energy conversion and management, vol. 47, pp. 2748-2760, 2006. [26] d. g. vutetakis and j. b. timmons, "a comparison of lithium-ion and lead-acid aircraft batteries," 2008. [27] c. xiang, et al., "a research on charge and discharge strategy of hybrid batteries based on the electrochemical characteristics," in telecommunications energy conference n. huda et al. / j. mechatron. electr. power veh. technol 06 (2015) 49–56 56 'smart power and efficiency' (intelec), proceedings of 2013 35th international, 2013, pp. 1-5. [28] b. bednar, et al., "diagnostic tool for lithium and lead-acid battery," in clean electrical power (iccep), 2013 international conference on, 2013, pp. 8486. [29] n. omar, et al., "rechargeable energy storage systems for plug-in hybrid electric vehicles-assessment of electrical characteristics," energies (19961073), vol. 5, pp. 2952-2988, 2012. [30] v. isastia and s. meo, "overview on automotive energy storage systems," international review of electrical engineering, vol. 4, pp. 1122-1144, 2009. [31] j. mcdowall, "conventional battery technologies-present and future," in power engineering society summer meeting, 2000. ieee, 2000, pp. 1538-1540 vol. 3. [32] m. gustavsson and d. mtonga, "lead-acid battery capacity in solar home systems— field tests and experiences in lundazi, zambia," solar energy, vol. 79, pp. 551558, 2005. [33] e. m. krieger, et al., "a comparison of leadacid and lithium-based battery behavior and capacity fade in off-grid renewable charging applications," energy, vol. 60, pp. 492-500, 2013. [34] r. spotnitz, "simulation of capacity fade in lithium-ion batteries," journal of power sources, vol. 113, pp. 72-80, 2003. [35] j. leadbetter and l. g. swan, "selection of battery technology to support grid-integrated renewable electricity," journal of power sources, vol. 216, pp. 376-386, 2012. [36] j. x. weinert, et al., "lead-acid and lithiumion batteries for the chinese electric bike market and implications on future technology advancement," journal of power sources, vol. 172, pp. 938-945, 2007. [37] p. cicconi, et al., "cooling simulation of an ev battery pack to support a retrofit project from lead-acid to li-ion cells," in vehicle power and propulsion conference (vppc), ieee, 2013, pp. 1-6. [38] k. t. chau, et al., "an overview of energy sources for electric vehicles," energy conversion and management, vol. 40, pp. 1021-1039, 1999. [39] s. j. gerssen-gondelach and a. p. c. faaij, "performance of batteries for electric vehicles on short and longer term," journal of power sources, vol. 212, pp. 111-129, 2012. [40] f. esposito, et al., "pso based energy management strategy or pure electric vehicles with dual energy storage systems," international review of electrical engineering, vol. 5, pp. 1862-1871, 2010. [41] a. m. genaidy, et al., "an exploratory study of lead recovery in lead-acid battery lifecycle in us market: and evidence-based approach," science of the total environment, p. 16, 2008. [42] r. l. lankey and f. c. mcmichael, "lifecycle methods for comparing primary and rechargeable batteries," environment and science technology, p. 6, 2000. [43] m. a. kreusch, et al., "technological improvements in automotive battery recycling," resources, conservation and recycling, p. 13, 2007. [44] i. b. weinstock, "recent advances in the us department of energy's energy storage technology research and development programs for hybrid electric and electric vehicles," journal of power sources, vol. 110, p. 4, 2002. [45] a. vasebi, et al., "a novel combined battery model for state-of-charge estimation in leadacid batteries based on extended kalman filter for hybrid electric vehicle applications," journal of power sources, vol. 174, p. 41, 2007. [46] d. m. kammen, "cost-effectiveness of greenhouse gas emission reductions from plug-in hybrid electric vehicles," 2008. [47] g. b. sreshtha and s. g. ang, "a study of electric vehicle battery charging demand in the context of singapore," presented at the power engineering conference, 2007. [48] r. faria, et al., "a sustainability assessment of electric vehicles as a personal mobility system," energy conversion and management, vol. 61, pp. 19-30, 2012. mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.59-66 the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation rizqon fajar a, *, hari setiapraja a a center for thermodynamic, motor and propulsion the agency for assessment and application of technology (btmp-bppt) komplek puspiptek gd. 230 serpong, indonesia received 27 december 2013; received in revised form 31 march 2014; accepted 07 may 2014 published online 23 july 2014 abstract experimental research has been conducted to investigate the effects of blend of hydrogenated and unhydrogenated jatropha biodiesel with diesel fuel in volume ratio of 30:70 (b30) on combustion characteristics (bsfc, thermal efficiency and smoke emission) of single cylinder diesel engine. in this experiment, engine speed was kept constant at 1,500, 2,500, and 3,500 rpm with maximum engine load at bmep 5 bar and injection timings were varied. experimental result showed that at engine speed 1,500 rpm, bsfc of b30 hydrogenated and unhydrogenated jatropha biodiesel were higher than it of diesel fuel at all injection timings (10° to 18° btdc). at the same condition, partial hydrogenated jatropha biodiesel showed higher bsfc than unhydrogenated jatropha biodiesel. however, the difference in bsfc became smaller for all fuels at engine speed 2,500 rpm and 3,500 rpm at all injection timing. jatropha biodiesel with and without partial hydrogenation tend to have higher thermal efficiency compared with diesel fuel at all engine speed and injection timing. the best injection timings to operate b30 jatropha biodiesel with and without hydrogenation were 14°, 18° and 24° btdc at engine speed 1,500, 2,500, and 3,500 rpm respectively. this conclusion was deduced based on the minimum value of bsfc and the maximum value of thermal efficiency. smoke emissions for all fuels were in the same level for all conditions. keywords: jatropha, hydrogenation, bsfc, thermal efficiency, smoke emission. i. introduction several alternative fuels which can contribute as solution for fossil fuel crisis and environment cleaner have been investigated extensively. biodiesel is one of such fuel due to its renewable and low exhaust gas emissions properties. for utilizing biodiesel in diesel engine, many researchers reported that non edible feedstock such as jatropha might be the best raw material since it would not influence on edible oil market. the mainly disadvantage of biodiesel made from non-edible oils is its low oxidation stability because the large content of poly unsaturated fatty acids, especially linoleic (c18:2) and linolenic acid (c18:3). various studies have shown that the oxidation stability of jatropha biodiesel does not meet the requirements defined by en 14214, in which the induction period should be a minimum of 6 h. most jatropha biodiesels were found had an induction period of about 3.23 to 4.21 h [1, 2, 3]. partial hydrogenation is a method to improve the oxidation stability with the minimum detriment to the cold-temperature properties. the partial hydrogenation is designed to convert the poly-unsaturated fame (fatty acid methyl esters) into mono-unsaturated and saturated fame. partial hydrogenation will alter the profile of fame compositions and hence the physical properties other than oxidation stability such as cetane number, pour point, and cold flow plugging point. fajar et al. [4] studied partial hydrogenation of jatropha biodiesel and showed that the oxidation stability improved from 4.16 to 5.99 h. the cetane number also increased slightly from 55.87 to 56.65 after the hydrogenation. wadumesthrige et al. [5] and papadopoulos et al. [6] also found the similar phenomenon after studying partial hydrogenation of biodiesel from poultry fat and cotton oil. after hydrogenation, the physical characteristic of jatropha biodiesel *corresponding author. tel: +62-81510389879 e-mail: rizqon66@gmail.com http://dx.doi.org/10.14203/j.mev.2014.v5.59-66 r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 60 especially the cetane number will change, that further more give a great effect on combustion characteristic. study on combustion of jatropha biodiesel and its blends have been studied by many researchers. in general, combustions of blend of jatropha biodiesel and diesel fuel have lower power than pure diesel fuel. moreover, fuel consumption using jatropha biodiesel blending is little higher than using pure diesel fuel. combustion of jatropha biodiesel blending tends to have lower emission of carbon monoxide and hydrocarbon compared with diesel fuel [7, 8, 9]. combustion characteristics of biodiesel can be predicted by fame composition or fuel properties related to combustion process such as cetane number, heating value and viscosity. partial hydrogenation of biodiesel will decrease total content of unsaturated fame and increase the content of saturated fame adversely. therefore, the changes on physical properties of biodiesel jatropha depend on partial oxidation conversion level. study conducted by puhan et al. [10] showed that biodiesel with high total content of unsaturated fame would have high cetane number, high calorie content and lower viscosity. therefore, hydrogenated jatropha biodiesel was expected to have higher cetane number, higher calorie content and lower viscosity compared with unhydrogenated jatropha biodiesel. besides that, the combustion of high content unsaturated fame produces higher carbon monoxide (co), hydrocarbon and smoke emissions. nox emission also tends to be higher due to its longer ignition delay. cetane number of hydrogenated jatropha biodiesel will be higher than original biodiesel as shown in table 4. the combustion characteristics will be different due to its shorter ignition delay. to optimize an increasing in cetane number, optimum setting of injection timing can be used as one method to get lower emissions while engine performance can be kept at optimum condition. therefore, mapping of engine performance related to setting of injection timing is necessary to investigate the effect of hydrogenation of biodiesel which then can result in the increasing in cetane number. various studies also show that setting of injection timing can be expected to achieve higher engine performance with lower emissions. beside from injection timing, combustion from diesel engine can also be evaluated from smoke emission. smoke is one of important parameter of exhaust gas emission consisting of solid and liquid phase. solid phase consist of carbon particle, sulphate, nitrate and liquid phase resulted from condensation of hydrocarbon. both of solid and liquid phase are the product of incomplete combustion. smoke number is also used as standard to determine the quality of combustion related to negative impact on human health. other parameters which can influence the combustion are injection pressure and compression ratio but it will not be discussed in this study. the objectives of this study were to investigate the effect of mapping injection timing on the performance of single cylinder diesel engine such as brake specific fuel consumption (bsfc), thermal efficiency (te) and smoke number, using blending fuel of jatropha biodiesel with and without hydrogenation with diesel fuel on volume ratio of 30:70 (b30). the best injection timing for jatropha biodiesel with and without hydrogenation will result minimum bsfc and smoke emissions with maximum thermal efficiency. ii. investigation procedure a. engine testing installation an experimental research was conducted on hydra single cylinder diesel engine with direct injection. the specification of the engine is shown in table 1. in this experiment, all engine characteristics and others related parameters for analyzing purposes such as air flow rate, fuel flow rate, exhaust gas pressure, and temperature were monitored and recorded. eddy current dynamometer was used to measure power and torque. here, engine load was kept constant at maximum level for all experimental condition. the engine test bench for this experiment is shown in figure 1. smoke emission was measured with avl 415s smoke meter with an accuracy of ±0.16 fsn. another parameters accuracy and uncertainty of power, bsfc and brake thermal efficiency (bte) are shown in table 2. figure 1. the installation of hydra single cylinder diesel engine r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 61 b. engine testing procedure the engine testing procedures for performance mapping were as follows: 1. testing was conducted at engine speed 1,500, 2,500 and 3,500 rpm respectively. 2. diesel fuel at full load was used as a reference. here, full load defined as engine load when smoke emission was at maximum of 5 bosch smoke number (bsn) which was equal to bmep 5 bar. 3. injection timings were varied during testing. 4. after testing the diesel fuel, fuel blending of diesel fuel and jatropha biodiesel (with and without hydrogenation) with volume ratio of 70:30 were tested at full load, the same conditions as diesel fuel. therefore, the performance parameter of all fuels could be seen from the value of brake specific fuel consumption and exhaust gas emission (smoke number). in this experiment, the engine was operated at optimum conditions in which the specific fuel consumption was low and the thermal efficiency was at the best value. these conditions could be achieved when the engine were set at full load. the engine speed was kept constant at 1,500, 2,500, and 3,500 rpm for the whole of experiment. the injection pressure was set constant at 250 bar. three type fuels tested in this experiment were hydrogenated jatropha biodiesel blended with diesel fuel with ratio 30:70 by volume (b30 with hydrogenation), unhydrogenated jatropha biodiesel blended with diesel fuel with ratio 30:70 by volume (b30), and a pure diesel fuel (b0) as a reference fuel. b30 was utilized with the reason that from study conducted by fajar et al. [11] b30 showed an acceptable condition for engine performance, emissions and fuel consumption without any engine modification. iii. results and discussion a. properties of tested fuels table 3 shows main properties of 3 types of fuels used in this experiment. the density of hydrogenated and unhydrogenated jatropa biodiesel was higher than it of diesel fuel and the heating value of both jatropha biodiesel was around 11% lower than diesel fuel (b0). table 4 shows main properties of diesel fuel, b100 hydrogenated biodiesel and b100 biodiesel without hydrogenation. cetane number and viscosity of hydrogenated and unhydrogenated jatropha biodiesel were higher than diesel fuel. b. effects of injection timing on bsfc performances of diesel engines fuelled with diesel fuel, b30 unhydrogenated jatropha biodiesel and b30 hydrogenated jatropha biodiesel at full load were evaluated based on parameters bsfc and brake thermal efficiency in various injection timing and engine speed. figure 2, 3, and 4 show the effect of various injection timing on bsfc for diesel fuel and b30 jatropha biodiesel with and without hydrogenation. diesel fuel had lowest bsfc compared with both of b30 unhydrogenated and hydrogenated jatropha biodiesel at engine speed table 4. properties of diesel fuel, b100 hydrogenated jatropha biodiesel and b100 unhydrogenated jatropha biodiesel properties diesel fuel jatropha biodiesel unhydroge nated a hydroge nated b oxidation stability, hour n/a 3.90 8.88 cetane number 51 55.65 58.97 kinematic viscosity at 40°c, cst 3.61 3.87 3.97 cloud point, °c n/a 3.35 5.31 pour point, °c n/a -3.20 -1.08 cfpp, °c n/a -2.02 1.08 a, b the properties were calculated based on the model proposed by chen et al. [3] table 1. engine specification engine parameters basic data bore x stroke 80.26 mm x 88.9 mm max. power 9 kw/3600 rpm compression 203 : 1 max. speed 4.500 rev/min injector bosch kbel 88pv 1 870 005 546 nozzle bosch 4 x 4 x 0.25 x 160 o inj. pressure 250 bar table 2. the measurement accuracy and uncertainty of calculation result parameter accuracy calculation result uncertainty load ±0.08 nm power ±2.6% speed ±1.6 rpm bsfc ±2.5 g/kwh time ±0.6 s bte ±2.6% table 3. tested fuel properties tested fuel density (g/cm 3 ) calorie cont. (mj/kg) diesel fuel (b0) 0.8522 44.87 b30 unhydrogenated jatropha 0.8613 43.37 b30 hydrogenated jatropha. 0.8604 43.51 r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 62 1,500 rpm. here the higher calorie content of diesel fuel could be a reason for lower bsfc of diesel fuel. however the difference of bsfc became smaller when the engine speed increased and it was comparable with optimization of injection timing for all fuels. the results also showed that optimum injection timing for all fuels were in the same timing and the difference of bsfc became smaller varied with engine speed. c. effects of injection timing on thermal efficiency figure 5, 6, and 7 show the effect of various injection timing on thermal efficiency for diesel fuel, b30 jatropha biodiesel with and without figure 2. bsfc at engine speed 1,500 rpm figure 3. bsfc at engine speed 2,500 rpm figure 4. bsfc at engine speed 3,500 rpm r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 63 hydrogenation at engine speed 1,500, 2,500, and 3,500 rpm. the figure showed that b30 biodiesel with hydrogenation had higher thermal efficiency than diesel fuel and b30 biodiesel without hydrogenation for all engine speed. the maximum thermal efficiency for b30 jatropha with and without hydrogenation happened at injection timing of 14°, 18°, and 24° btdc at engine speed 1,500, 2,500, and 3,500 rpm respectively. meanwhile for diesel fuel, the maximum thermal efficiency was achieved at injection timing of 14°, 22°, and 24° btdc. from figure 2, 3, and 4, the minimum bsfc and the maximum thermal efficiency for all fuels were achieved at the same injection timing. the high thermal efficiency of b30 jatropha biodiesel figure 5. thermal efficiency of tested fuels at engine speed 1,500 rpm figure 6. thermal efficiency of tested fuels at engine speed 2,500 rpm figure 7. thermal efficiency of tested fuels at engine speed 3,500 rpm r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 64 with hydrogenation might be caused by the increasing in cetane number and calorie content. the increasing in cetane number and calorie content for jatropha biodiesel after hydrogenation could improve the combustion and also the thermal efficiency. d. effects of injection timing on smoke emission smoke emission is one of important exhaust gas parameter since it shows an efficiency of combustion. smoke also becomes parameter for judgment of diesel engine condition related to performance of fuel injection systems and fuel properties. figure 8, 9, and 10 show smoke figure 8. smoke emission of tested fuels at engine speed 1,500 rpm figure 9. smoke emission of tested fuels at engine speed 2,500 rpm figure 10. smoke emission of tested fuels at engine speed 3,500 rpm r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 65 emission at various injection timing for diesel fuel and b30 jatropha biodiesel with and without hydrogenation. smoke emissions of b30 jatropha biodiesel with and without hydrogenation were lower than it of diesel fuel for all injection timings and engine speeds. in general, although it was not significant, smoke became lower if the injection time was advanced. this phenomenon could be explained as follows: advancing the injection timing would shift part of diffusion combustion into premixed combustion. here, fuel would be more accumulated during ignition delay period and caused an increasing in cylinder temperature during expansion stroke and gave enough time for oxidation of soot particle. figure 8 to 10 also show that smoke numbers vary in a range of 4 to 5 at tested engine speed. iv. conclusion in this experiment biodiesel made from jatropha with and without hydrogenation were blended with diesel fuel with ratio of 30:70 by volume. combustion characteristics (bsfc, thermal efficiency and smoke number) were analyzed and compared with ordinary diesel fuel available in indonesia at various injection timing and at engine speed of 1,500, 2,500, and 3,500 rpm. the results might be summarized as follows: the bsfc of b30 jatropha biodiesel with and without hydrogenation were higher than it of diesel fuel at 1,500 rpm on all of the variations of injection timing (10° to 18° btdc). the difference in bsfc between the fuels would be smaller if the engine speed increased up to 3,500 rpm. thermal efficiencies of the combustion of b30 biodiesel with and without hydrogenation tend to be higher than that of diesel fuel at all injection timing, especially at high engine speed 3,500 rpm. the highest thermal efficiency for b30 with and without hydrogenation was 36% and for diesel fuel was 35%. these values were achieved at engine speed 3,500 rpm and injection time 24° btdc. the smoke level of b30 jatropha biodiesel with and without hydrogenation were quite similar compared with diesel fuel at all injection timing, smoke emission tended to increase when engine speed increased from 1,500 to 3,500 rpm. the best injection timings to operate b30 jatropha biodiesel with and without hydrogenation were 14°, 18°, and 24° btdc at engine speed 1,500, 2,500, and 3,500 rpm respectively. this conclusion was deduced based on the minimum value of bsfc and the maximum value of thermal efficiency. acknowledgement the authors thank to the center for thermodynamics, motor & propulsion system bpp teknologi indonesia for financial and technical support. references [1] a. sarin et al., “effect of blends of palmjatropha-pongamia biodiesels on cloud point and pour point,” energy, vol. 34, pp. 2016-2021, 2009. [2] d. chaithongdee et al., “effect of antioxidant and additives on the oxidation stability of jatropha biodiesel,” kasetsart journal natural science, vol 44, pp. 243250, 2010. [3] y.h. chen et al., “property modification of jatropha oil biodiesel by blending with other biodiesels or adding antioxidants,” energy, vol. 36, pp. 4415-4421, 2011. [4] r. fajar et al., “predicting fuel properties of partially hydrogenated jatropha methyl ester: used for biodiesel formulation to meet the fuel specification for automobile and engine manufacturer,” kasetsart journal natural science, vol. 46, pp. 629637, 2012. [5] k. wadumesthrige et al., “effects of partial hydrogenation, epoxidation, and hydroxylation on the fuel,” fuel processing technology, vol. 90, pp. 12921299, 2009. [6] c. e. papadopoulos et al., “optimization of cotton seed biodiesel quality (critical properties) through modification of its fame composition by highly selective homogeneous hydrogenation,” bioresource technology, vol. 10, pp. 1812–1819, 2010. [7] t. ganapathy et al., “influence of injection timing on performance, combustion and emission characteristics of jatropha biodiesel engine,” applied energy, vol. 88(12), pp. 4376-4386, 2011. [8] b. s. chauhan et al., “a study on the performance and emission of a diesel engine fueled with jatropha biodiesel oil and its blends,” energy, vol. 37, pp. 616622, 2012. [9] c. y. chen et al., “fuel properties and combustion characteristics of jatropha oil biodiesel–diesel blends,” journal of the taiwan institute of chemical engineers, vol. 44, pp. 214-220, 2013. [10] s. puhan et al., “effect of biodiesel unsaturated fatty acid on combustion characteristics of a di compression ignition r. fajar and h. setiapraja / mechatronics, electrical power, and vehicular technology 05 (2014) 59-66 66 engine,” biomass and bioenergy, vol. 34, pp. 1079-1088, 2010. [11] r. fajar et al., “efek penggunaan biodiesel kualitas standar pada kendaraan komersial,” laporan teknis btmp-bpp teknologi, 2004. microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 61 ra�ca�g ba�gu� aplikasi tele-ke�dali komputer via jari�ga� pst� de�ga� modul dtmf da� mikroko�troller atti�y2313 yuliadi erdani, hendy rudiansyah jurusan teknik otomasi manufaktur dan mekatronika politeknik manufaktur negeri bandung jl. kanayakan no. 21 bandung jawa barat 40275, indonesia yul_erdani@yahoo.com; yul_erdani@polman-bandung.ac.id diterima: 27 oktober 2010; direvisi: 1 desember 2010; disetujui: 13 desember 2010; terbit online: 24 desember 2010. abstrak jarak pengendalian yang sangat jauh, target/aktuator yang sulit dijangkau, serta pembangunan jaringan pengendali yang sulit dan mahal, menjadi beberapa masalah dalam sistem pengendalian jarak jauh. contohnya adalah dalam pengendalian komputer-komputer pada papan iklan digital/digital signage yang kerap disimpan di tempat-tempat yang sulit dijangkau, seperti di atas jembatan penyebrangan, di persimpangan jalan, dan sebagainya. perusahaan pengelola kerap melakukan penonaktifan alat guna menghemat energi, namun belum ada alat yang memadai untuk mengendalikannya. oleh karena itu, pengendalian dengan menggunakan jaringan telepon baik kabel maupun selular menjadi solusi yang tepat. selain lingkup kendali yang sangat luas, telepon juga sangat mudah dioperasikan. rangkaian aplikasi yang dikembangkan pada penelitian ini menggunakan dual tone multi frequency yang dibangkitkan melalui penekanan tombol telepon yang dijadikan data input pengendali mikrokontroller. data frequency diubah menjadi data digital, lalu data tersebut dijadikan input pengendali mikrokontroller. mikrokontroller kemudian mengendalikan komputer melalui relay dan port serial. hasil percobaan menunjukan bahwa aplikasi yang dikembangkan ini mampu mematikan dan menghidupkan komputer serta perangkat lunak aplikasi pada komputer dari jarak jauh. kata kunci : dual tone multi frequency, tele-control, kendali dengan phone. abstract extremely long distance control, hardly reachable actuator/target and costly network development are some concerns whithin a distance control system. such control is computer control for advertisements placed in tricky areas as locations over the bridge, at a junction, etc. the provider usually performs system inactivation in order to save energy. but until now, it is still difficult to find a system that can be turned on and off in remote manner. that is why the distant control using telephone can be the best alternative solution. �ot only can the telephone be used in wide range of area, but also easily operated. the developed circuit in this research uses dual tone multiple frequency (dtmf). it is operated by pressing telephone button as control input for microcontroller. the microcontroller processes the input and controls the computer via relay and serial port. the result of experiment shows that the developed application is able to shut down and turn on computer as well as to apply software remotely. keywords: dual tone multi frequency, tele-control, control by phone. i. pe�dahulua� pengendalian jarak jauh di tempat-tempat yang sulit dijangkau membutuhkan jaringan komunikasi data pengendali yang memiliki jangkauan luas dan instalasi yang mudah sehingga pengaksesan objek yang dikendalikan dapat dilakukan dengan mudah dan efisien. jaringan yang dimaksud adalah jaringan dengan ruang lingkup yang sangat luas, antar kota bahkan nasional atau internasional [1]. salah satu yang memungkinkan adalah jaringan telepon, baik telepon seluler maupun telepon kabel [2]. dalam penelitian ini, akan didalami tentang bagaimana memanfaatkan dual tone multi frequency (dtmf) pada telepon sebagai data input pengendali. data frekuensi tersebut akan dikirim melalui hubungan telepon kemudian diterima dan diubah menjadi data digital. data digital ini yang kemudian akan dijadikan input pengendali [3] [4]. dengan adanya alat ini, pengendalian dalam lingkup yang sangat luas dapat dilakukan tanpa harus membangun jaringan komunikasi yang baru. rancang bangun aplikasi tele-kendali komputer via jaringan pst� dengan modul dtmf dan mikrokontroller attiny2313 (yuliadi erdani, hendy rudiansyah) pp. 61-68 62 ii. isi makalah seperti terlihat pada diagram pada gambar 1, alat pengendali ini dirancang untuk mengendalikan komputer dari jarak jauh melalui telepon. pengendali dapat mengendalikan komputer dari mana pun selama alat dan pengendali masih berada dalam jangkauan jaringan telepon, baik sellular maupun kabel. nada dtmf yang dapat terdengar ketika telepon tersambung dijadikan data input pengendalian. sedangkan aktuatornya adalah relay dan program computer control pada komputer yang menerima perintah melalui komunikasi serial. gambar 1. diagram blok sistem. relay dikendalikan langsung oleh mikrokontroller melalui salah satu port. relay digunakan untuk menyalakan komputer, karena program computer control belum aktif. sedangkan pengendalian melalui komunikasi serial digunakan untuk shutdown, restart, atau untuk mengaktifkan suatu program tertentu. telepon pada alat diatur agar menjawab secara otomatis. ketika telepon tersambung, nada dtmf dikirimkan melalui sambungan telepon dengan menekan tombol pada telepon pengguna. melalui port audio pada telepon penerima, frekuensi dtmf diterima dan diterjemahkan ke dalam data digital 4 bit oleh dekoder dtmf [5]. mikrokontroller attiny2313 sebagai pengendali menerima data tersebut sebagai input . sebagai penerima komunikasi dari mikrokontroller, program computer control harus disalin terlebih dahulu ke komputer yang akan dikendalikan. program dibuat di microsoft visual basic berupa berkas aplikasi [9] [10]. program tersebut diatur agar aktif ketika start up. sehingga ketika komputer aktif, pengendali sudah bisa mengendalikan komputer. tahapan pembuatan alat meliputi perancangan, pembuatan, dan ujicoba. perancangan terdiri dari perancangan perangkat keras dan perangkat lunak. untuk perangkat keras meliputi, rangkaian dekoder dtmf, sistem minimum mikrokontroller attiny2313, dan transmisi komunikasi data antara mikrokontroller dan komputer melalui pengubah level tegangan ttlcmos. sedangkan untuk perangkat lunak meliputi program pengendali mikrokontroller menggunakan bahasa c dan program pengendali internal pada komputer yang dibuat menggunakan visual basic. tahap berikutnya adalah pembuatan alat, dimualai dari pembuatan perangkat keras, ujicoba perangkat keras, lalu dilanjutkan dengan pembuatan perangkat lunak. terakhir barulah pengintegrasian antara perangkat keras dan lunak. masukan mikrokontroller berasal dari dekoder dtmf, yaitu 4 bit data hasil konversi dan 1 bit indikator pendeteksian nada dtmf. kelima bit tersebut dihubungkan ke pinb.0 sampai pinb.4. sedangkan 3 bit sisanya dialokasikan untuk keluaran. portb.5 untuk pwdn, portb.6 untuk buzzer, dan portb.7 untuk relay [8]. pengkoneksian dua alat yang memiliki level tegangan berbeda harus melalui konverter level tegangan agar komunikasi dapat berlangsung. seperti terlihat pada gambar 3. 3 level konversi dari tegangan rs232 dan ttl maupun sebaliknya menggunakan ic max232. level tegangan rs232 adalah -3 volt sampai dengan 25 volt merupakan logic high sedangkan 3 volt sampai dengan 25 volt merupakan logic low. untuk level ttl, 5 volt merupakan logic high dan 0 volt merupakan logic low. gambar 2. rangkaian dekoder dtmf. pada rangkaian sistem minimum attiny2313 telah tergambar bahwa pada intinya receiver pada komputer menerima data dari transmitter mikrokontroller dan receiver mikrokontroller menerima data dari transmitter komputer. sehingga komunikasi dua arah dapat dilakukan dengan menghubungkan port db9 pada mikrokontroller (female) dengan db9 pada computer (male) melalui kabel straight, bukan cross. rangkaian dekoder dtmf yang digunakan adalah rangkaian tipe single ended input seperti terlihat pada rangkaian di gambar 2. keterangan lebih lengkap mengenai tipe rangkaian dapat dilihat pada datasheet mt88l70ac [10]. journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 63 pengaktifan buzzer menggunakan transistor dengan memanfaatkan salah satu fungsinya, yaitu sebagai sakelar elektronik. pada alat ini, buzzer yang digunakan adalah buzzer 5v. buzzer digunakan untuk memberi informasi kepada penelpon atas proses pengendalian yang berlangsung. gambar 3. rangkaian buzzer. cara kerja rangkaian relay di bawah ini sama dengan rangkaian buzzer. adapun fungsi relay pada alat ini adalah untuk mengaktifkan komputer. kontak normally open (no) dihubungkan ke pin power on pada motherboard komputer, diparalelkan dengan tombol power komputer. ada dua jenis program yang diperlukan, program untuk mikrokontroller dan program computer control yang dibuat di microsoft visual basic 6.0. program computer control akan menjadi penerima perintah dari mikrokontroler. data masukan ke mikrokontroller berupa kode penekanan tombol telepon dari dekoder dtmf [7]. jika kode perintah benar, mikrokontroller akan mengirimkan data string ke komputer sebagai kode perintah (untuk shutdown, restart, atau mengaktifkan program) dan atau mengaktifkan komputer melalui relay sesuai dengan kode yang diterima. jika tejadi kesalahan kode, mikrokontroller akan memberikan pemberitahuan error melalui buzzer yang akan terdengar oleh penelpon. sebagai umpan balik kepada pengguna atas perintah yang berhasil dijalankan, mikrokontroller memberikan kode melalui suara buzzer yang diatur agar berbunyi dalam rentang dan konfigurasi tertentu. gambar 4. rangkaian relay. kedua program yang telah dituliskan di atas merupakan syarat yang harus dipenuhi guna terjadinya komunikasi antara computer dan mikrokontroller. komunikasi yang digunakan adalah komunikasi uart (unsynchronous) karena pendetakkan dari kedua alat yang berkomunikasi dilakukan masing-masing. oleh karena itu, bagian utama yang harus diperhatikan adalah inisialisasi komunikasi serial tersebut, dari mulai pengaturan baud rate, data, paritas, dan port komunikasi yang digunakan. berikut diagram alir program mikrokontroller dan computer control. program difungsikan untuk menerima dan mengolah input dari dekoder dtmf. sebagai pengaman, setiap perintah terdiri dari 3 penekanan. penekanan pertama sebagai kode lewat berupa penekanan tombol bintang, penekanan kedua sebagai pemilih perintah, dan penekanan ketiga berupa kode penutup berupa penekanan tombol pagar. perintah hanya akan dijalankan jika ketiga kode tersebut benar. jika kode salah, mikrokontroller akan memberikan umpan balik berupa kode error. gambar 5. diagram alir program mikrokontroller. rancang bangun aplikasi tele-kendali komputer via jaringan pst� dengan modul dtmf dan mikrokontroller attiny2313 (yuliadi erdani, hendy rudiansyah) pp. 61-68 64 untuk perintah mematikan, restart, dan membuka file, peran mikrokontroller adalah sebagai pengirim perintah ke komputer melalui komunikasi serial. data yang dikirimkan berupa data string. mikrokontroller akan memberikan informasi status perintah yang telah dikirimkan ke komputer setelah program computer control mengirimkan umpan balik kepada mikrokontroller. informasi tersebut berupa bunyi buzzer dengan konfigurasi seperti terlihat pada tabel 3.1. gambar 6. diagram alir program computer control. program menerima masukan berupa data string dari mikrokontroller melalui komunikasi serial asinkron. terdapat empat pilihan perintah yang dapat dikerjakan program tersebut, yaitu shutdown, restart, dan membuka file. konfigurasi ini dapat diubah sesuai kebutuhan dengan merubah list program. tabel 1. data keluaran dekoder dtmf. tombol keluaran tombol keluaran 1 0001 7 0111 2 0010 8 1000 3 0011 9 1001 4 0100 0 1010 5 0101 * 1011 6 0110 # 1100 iii. hasil & a�alisis pe�elitia� pengujian bagian ini meliputi penggambaran gelombang nada dtmf sebagai masukan rangkaian dtmf dan pengecekan 4 bit data keluaran beserta 1 bit indikator pendeteksian nada dtmf. gambar 7. gelombang dtmf untuk tombol 6. berikut daftar kode perintah beserta data yang dikirim ke komputer: tabel 2. input/output program mikrokontroller. input fugsi data yang dikirim *2# shutdown komputer “matikan” *3# restart komputer “restart” *4# membuka file_a “file_a” *5# membuka file_b “file_b” dekoder mengeluarkan output data digital 4 bit dan 1 bit indikator pendetksian nada dtmf. input mikrokontroller adalah data 5 bit dari dekoder dtmf yang merepresentasikan penekanan tombol-tombol telepon. untuk keperluan pengamanan, input tersebut dibentuk ke dalam kode perintah tiga digit. journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 65 tabel 3. data string keluaran mikrokontroller. data gelombang matikan restart file_a file_b program computer control ini befungsi sebagai pengendali internal komputer. fungsi utamanya adalah untuk melakukan shutdown komputer, restart komputer, dan membuka file tertentu yang telah ditentukan sebelumnya. fungsi tersebut dijalankan ketika program menerima perintah dari mikrokontroller. untuk keperluan percobaan dan pengaturan manual, fungsi tersebut dibuat juga antarmukanya berupa tombol-tombol. program aktif bersamaan dengan aktifnya komputer dengan cara menyalin program pada rancang bangun aplikasi tele-kendali komputer via jaringan pst� dengan modul dtmf dan mikrokontroller attiny2313 (yuliadi erdani, hendy rudiansyah) pp. 61-68 66 folder start up. gambar 8 berikut menunjukkan tampilan antarmuka untuk program computer control dan tampilannya pada system tray. gambar 8. program computer control pada sistem tray. gambar 9. tampilan antarmuka program. program tersebut memiliki tiga perintah utama yang dapat dilaksanakan. perintah utama tersebut masing-masing ditulis dalam satu prosedur. prosedur dipanggil ketika data masukan sesuai dengan komparasi di program. untuk pemindaian data masukannya itu sendiri digunkan 2 timer yang aktif bergantian dengan interval waktu 10ms. 1) scanning data masukan private sub timer1_timer() 'scanning data yang masuk if data = "matikan" then mati_click umpanbalik 'memanggil prosedur ‘umpan balik ke mikrokontroller else timer2.enabled = true timer1.enabled = false end sub private sub timer2_timer() timer1.enabled = true timer2.enabled = false end sub 2) perintah shutdown komputer private sub mati_click() 'prosedur untuk shutdown shell "shutdown.exe -s -f -t 0" end sub 3) perintah restart private sub mati_click() 'prosedur untuk restart shell "shutdown.exe -r -f -t 0" end sub 4) perintah membuka file private sub filea_click() shellexecute me.hwnd, "open", "c:\program files\computer control\file_a.pps", vbnullstring, "c:\", byval 1& end sub program computer control melaksanakan pengendalian dan memberikan umpan balik kepada mikrokontroller dengan mengirim data string. berikut daftar umpan balik untuk setiap perintah yang dilaksanakan. tabel 4. perintah dan data umpan balik computer control. perintah umpan balik shutdown komputer “matiok” restart komputer “restok” membuka file_a “fileaok” membuka file_b “filebok” fitur lain dari program computer control adalah memungkinkannya pengaturan mscomm. mscomm dapat diatur pada menu mscomm setting. tampilan di bawah adalah pengaturan default program. pengaturan diperlukan untuk mengganti salah satu properties dari mscomm jika diperlukan. untuk menampilkannya, tekan menu serial lalu setting. sedangkan dua sub menu lainnya adalah buka dan tutup port untuk menutup dan membuka port komunikasi yang digunakan. gambar 10. tampilan menu comm setting. icon program computer control pada sistem tray journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 67 tabel 5. data string keluaran komputer ke mikrokontroller. data gelombang matiok restok fileaok filebok semua data yang diambil merupakan data percobaan yang dilakukan berulang-ulang (sekitar 10 kali). berdasarkan data yang diperoleh, sistem yang dikembangkan ini menunjukan suatu sistem yang cukup handal, karena menghasilkan data yang cukup stabil. demikianpun dengan waktu tanggap sistemnya, sistem tersebut mampu memberikan respon dalam waktu yang cukup singkat, sesuai dengan desain, meskipun penggunaannya telah dilakukan secara berulangulang. rancang bangun aplikasi tele-kendali komputer via jaringan pst� dengan modul dtmf dan mikrokontroller attiny2313 (yuliadi erdani, hendy rudiansyah) pp. 61-68 68 iv. kesimpula� da� sara� kesimpulan yang dapat diambil dari makalah ini adalah alat pengendali komputer ini menggunakan mikrokontroller attiny2313 sebagai pengendali eksternal komputer dan program computer control sebagai pengendali internal komputer. pengendalian dilakukan dengan cara memanggil telepon pada alat lalu menekan kode perintah setelah panggilan dijawab secara otomatis. alat dapat digunakan untuk membuka file pada komputer, power on, shutdown, dan restart komputer. program shutdown control mengirim umpan balik ketika data perintah telah diterima mikrokontroller, lalu mikrokontroller mengirimkan informasi umpan balik dalam bentuk bunyi buzzer. ruang lingkup pengendalian mencapai lingkup global dan sangat bergantung pada ada tidaknya jaringan telepon. ucapa� terimakasih ucapan terimakasih disampaikan kepada sdr ajie jamaludin, alumni ae polman bandung angkatan tahun 2007 yang telah membantu kelancaran kegiatan penelitian ini, serta kepada proyek i-mhere melalui program research grant atas biaya yang diberikan untuk kegiatan penelitian ini daftar pustaka [1] sharma, r.. et al., “dtmf based remote control system”, ieee international conference, icit 2006. isbn: 1-42440726-5 [2] yun chan cho and jae wook jeon, “remote robot control system based on dtmf of mobile phone”, industrial informatics, i�di� 2008. 6th ieee international conference, 2008. isbn: 978-1-4244-2170-1 [3] manojkumar, mathankumar, saranya, pavithradevi, “mobile controlled robot using dtmf technology”, international journal of electronic engineering research., volume 2 number 3, pp. 349– 355, 2010. issn 0975 – 6450 [4] t. ramashri and p. gangadhara reddy, “adaptive channel equalizer and dtmf detection”, arp� journal of engineering and applied sciences, vol. 3, no. 2, april 2008. issn 1819-6608. [5] schenker, l., “pushbutton calling with a two-group voice-frequency code”, the bell system technical journal vol:39, pp:235255, 1960. issn 0005-8580. [6] i. coskun and h. ardam, “a remote controller for home and office appliances by telephone”, ieee trans. consumer electron, vol. 44, no. 4, pp. 12911297, november 1998 [7] yavuz erol, et al., “safe and secure pic based remote control application for intelligent home, ijcs�s international journal of computer science and �etwork security, vol.7 no.5, may 2007 [8] wilson, verne. 1989. dual tone multi frequency (dtmf), diakses pada 30 april 2010 dari www.national.com [9] octovhiana, krisna d. “cepat mahir visual basic 6.0,” ilmukomputer.com. 2003 [10] perry, gregg., “visual basic dalam 12 pelajaran yang mudah”, yogyakarta : andi, 1995. [11] noname, “datasheet integrated dtmf receiver mt88l70ac” j. mechatron. electr. power veh. technol 06 (2015) 39–48 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.39-48 geometry analysis and effect of turbulence model on the radial rotor turbo-expander design for small organic rankine cycle system maulana arifin a, *, ari darmawan pasek b , zaidan eddy a a research centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu/sangkuriang, bandung 40135, indonesia b thermodynamics laboratory, faculty of mechanical and aerospace engineering, bandung institute of technology received 04 february 2015; received in revised form 03 june 2015; accepted 03 june 2015 published online 30 july 2015 abstract organic rankine cycle (orc) is one of the most promising technology for small electric power generations. the geometry analysis and the effect of turbulence model on the radial turbo-expanders design for small orc power generation systems were discussed in this paper. the rotor blades and performance were calculated using several working fluids such as r134a, r143a, r245fa, n-pentane, and r123. subsequently, a numerical study was carried out in the fluid flow area with r134a and r123 as the working fluids. analysis were performed using computational fluid dynamics (cfd) ansys multiphysics on two real gas models, with the k-epsilon and shear stress transport (sst) turbulence models. the result shows the distribution of mach number, pressure, velocity, and temperature along the rotor blade of the radial turbo-expanders and estimation of performance at various operating conditions. the operating conditions are as follow: 250,000 grid mesh flow area, real gas model sst at steady state condition, 0.4 kg/s of mass flow rate, 15,000 rpm rotor speed, 5 bar inlet pressure, and 373 k inlet temperature. by using those conditions, cfd analysis shows that the turbo-expander able to produce 6.7 kw and 5.5 kw of power when using r134a and r123, respectively. keywords: radial turbo-expander; cfd; k-epsilon; shear stress transport; organic rankine cycle. i. introduction climate change concerns coupled with high oil prices are driving research and development on renewable energies such as solar and geothermal energy. one of electric power generation technology that can be used to utilize renewable energy potency in remote area is organic rankine cycle (orc). orc uses organic fluid as the working fluid to provide higher thermal cycle efficiency compared to the conventional steam rankine cycle at temperature heat source below 300°c. orc has been studied as the utilization of waste heat recovery [1, 2], solar energy [3], the combination of heat and power (chp) [4], geothermal [5], and heat recovery from the exhaust gases from the engine [6]. the results of experimental studies show that the small-scale units orc has a promising performance for power generation especially in remote areas [7]. the orc could provide a wide output power range, but consist of less components, so that the orc could be more compact and smaller in size compared to conventional electric power plants. most studies were focused on the thermodynamic analysis of the orc, and the selection of the working fluid, with particular attention to obtain the best efficiency of power generation. on the other hand, only few published papers discuss on the design and geometry optimization of turboexpander. basically, for output power ranges from 5 to 5,000 kw two types of turbines are proposed, axial or radial turbines. the latter turbine type is considered more attractive, since it has better performance at small output capacity. in basic analysis for optimizing orc system, isentropic efficiency of expander is specified as a constant value for all working fluids and all conditions. the constant value for all working fluids makes error in theoretical analysis of orc system. by using different working fluids, the expander has optimum value and different * corresponding author. tel: +62-22-2503055 e-mail: maul004@lipi.go.id m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 40 performance [8]. therefore, it is important to study internal analysis of turbo-expander for developing knowledge on geometry design and its relation to the performance of radial turboexpanders in orc systems. the objectives of this study are to calculate the geometry of a radial inflow turbo-expander for small orc system and predict its performance for various working fluids and operating conditions. ii. geometry analysis of radial rotor turbo-expander baines’s method [9] is normally used for preliminary geometry design of radial turbines. this paper deals with a radial turbo-expander shown in figure 1, where important parameters for geometry design can be observed [10]. load coefficient ψ and flow coefficient ϕ can be calculated based on the velocity u4 and can be calculated using euler’s turbo machinery equation as in equation (1). 4 6 4 4 2 4 0 u c u c u h      (1) where ψ is load coefficient, δh0 is entalphy drop in isentropic expansion or specific work output (j/kg), u4 is blade speed at inlet condition (m/s), cθ4 is absolute tangential velocity at inlet condition (m/s), ε is radius ratio of rotor (r6/r4), cθ6 is absolute tangential velocity at outlet condition (m/s). figure 2 shows the meridional plane geometry on the radial turbo-expanders. in this model the rotor shroud contour is assumed to be a circle, while the rotor hub to the contours is described as elliptical geometry assumptions made by glassman [11]. by assuming that magnitude of outlet swirl is very small, the load coefficient can be predicted as in equation (2). hence the rotor inlet velocity triangle at station four (inlet) is defined in equation (3) to (5). 4 4 u c  (2) 44 uc m  (3)  2 1 2 4 2 44 ccc m  (4)           4 41 4 tan m c c (5) where cm4 is absolute meridional velocity at inlet condition (m/s), ξ is meridional velocity ratio, ϕ is flow coefficient, c4 is absolute velocity at inlet condition (m/s), α4 is absolute flow angle at inlet condition (degree). the static temperature t4 and the static pressure p4 at the inlet to the rotor are calculated from equation (6)-(10).            4 441 4 tan m c uc (6) p c c tt 2 2 4 044  (7)  1 04 4 044           k k t t pp (8) figure 1. geometry parameters of radial turbo-expander m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 41  4 4 u r  (9)   444 4 2 m cr m b    (10) where β4 is relative flow angle at inlet condition (degree), t4 is static temperature at inlet condition (k), t04 is total temperature at inlet condition (k), cp is specific heat at constant pressure (j/kg.k), p4 is static pressure at inlet condition (bar), p04 is total pressure at inlet condition (bar), k is ratio of specific heats, r4 is radius rotor at inlet condition (m), ω is angular velocity (rpm), b4 is blade height at inlet condition (m), ṁ is mass flow (kg/s), ρ is density (kg/m 3 ). t04 = t01 (total temperature at inlet, k) and p04 = p01 δp0 (total pressure at inlet, bar) δp0 is the total pressure loss in the stator (bar). inlet area a4 is given by equation (11). the number of blades zr and total to static isentropic efficiency ηts are defined as shown in equation (12)-(13) [11]. 44 4 4 m cp rtm a   (11)     30 tan110 44   zr (12) loss ts hh h    0 0 (13) where 𝐴4 is area at inlet condition (m), r is universal gas constant (8.314 kj/kmol.k), zr is blade number, ℎ𝑙𝑜𝑠𝑠 is total enthalpy losses (j/kg), 𝜂𝑡𝑠 is total to static efficiency. results of geometry design are shown in table 1. figure 3 shows model for radial rotor turbo-expander with geometry obtained from the design process. iii. cfd simulation cfd simulation was done with various number of grids to know the influence of number of grid on the simulation speed and accuracy. table 2 shows operational condition of the radial turbo-expander the grid number used in the simulation. ansys multiphysics provide 2 types of turbulence models for real gas, the k-epsilon, and shear stress transport (sst). the influence of these model on the simulation results were investigated. in this paper, simulations were performed at steady state condition using various rotor speeds 15,000 rpm, 20,000 rpm, and 30,000 rpm. after the simulation pressure, temperature distribution and torque variation in the rotor were analyzed, using equation (14) to calculate performance of turbo-expander, where p is power output of turbo-expander (kw). 𝑃 = 𝑚 ∆ℎ0 (14) figure 2. the meridional-plane geometry on the radial turbo-expander m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 42 iv. result and discussion numerical simulations using the finite volume method were done to find the fluid flow characteristics, that able to predict the resulted torque, power, and efficiency of the designed turbo-expander. the simulation was done at various of model number of grids, rotational speeds, and working fluids. the number of grid are coarse grid (20,000 mesh), medium grid (100,000 mesh), and fine grid (250,000 mesh). figure 4 shows velocity contour model with figure 3. result geometry radial rotor turbo-expander for small organic rankine cycle system table 1. result for geometry parameter rotor radial turbo-expander parameter unit r134a r123 r245fa r143a npentane input parameter mass flow (ṁ) kg/s 0.40 0.40 0.40 0.40 0.40 angular velocity (ω) rpm 20,000 20,000 20,000 20,000 20,000 total temperature at inlet (t04) k 373 373 373 373 373 number of blades (zr) 12 12 12 12 12 output parameter absolute meridional velocity (cm4) (inlet) m/s 50 44 43 48 49 blade speed (u4) m/s 167 146 143 160 163 absolute tangential velocity (cθ4) m/s 150 132 129 144 147 absolute flow angle (inlet) (α4) degree 71.57° 71.57° 71.57° 71.57° 71.57° relative flow angle (inlet) (β4) degree -18.43° -18.43° -18.43° -18.43° -18.43° absolute velocity (c4) m/s 158 139 136 151 155 relative velocity (w4) m/s 52.7 46.38 45.33 50.60 51.60 inlet temperature (t4) k 360.47 361.15 364.37 362.60 367.37 inlet pressure (p4) bar 3.60 3.75 3.93 3.85 4.15 inlet area (a4) m 2 6.5x10 -4 4.7x10 -4 5.3x10 -4 7.7x10 -4 8.3x10 -4 radius rotor (r4) m 0.100 0.093 0.091 0.101 0.104 inlet blade height (b4) m 0.010 0.008 0.009 0.012 0.012 inlet density (ρ4) kg/m 3 12.238 19.121 17.384 10.737 9.813 inlet mach number (m4) 0.87 0.93 0.85 0.75 0.72 m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 43 different number of grids using r123 as working fluid at 20,000 rpm. model with high number of grid (250,000 mesh), gives better results and shows comparison of the computation time and the number of iterations for the k-epsilon and sst turbulence models. with high number of grid, a strong vortex can be seen. this vortex form a higher pressure area in the region after the leading edge, separating flow from the hub surface and moving it up the blade toward the tip. other calculation results obtained from the simulation for r123 and r134 working fluids are listed in table 3. table 4 shows comparison of the computation time and the number of iterations for the kepsilon and sst turbulence models. from figure 4, it can be seen that sst model has good swirl flow prediction on blade passage and results higher power output. for k-epsilon turbulence model, the power ouput is 6.1 kw while for the sst models the power output is 7.2 kw, which is 18% higher. a better model between those two cannot be verified in this study; however experimental results on the expander model may clarify this discrepancy. the results of an aerodynamic evaluation of rotor radial turbo-expander using sst turbulence model are shown in figure 5 and figure 6. this rotor is designed for a low specific speed rotor radial turbo-expander with inlet and outlet ratio under 1. the lower specific speed makes the outlet area of rotor considerably small. this makes the outlet tip of rotor smaller than the inlet area of rotor. the outlet blade's height of rotor is also smaller than the inlet area of rotor [9]. the results are different with conventional characteristic of rotor radial turbo-expander of this type. at rotor with low specific speed using air as working fluid, the fluid flow is more uniform. meanwhile, at rotor radial turbo-expander using r123 and r134a as working fluid, a strong vortex is forming on the pressure surface soon after the leading edge, separating flow from the hub surface and moving flow up to the blade toward the tip. it is interesting to note that the pressure gradient introduced in inlet region of the blade passage affect even the flow upstream of the leading edge quite strong. the large variations in flow field that are created in the passage cause very significant changes in the outlet flow (figure 7). contours of both relative and absolute flow angle downstream of the trailing edge. table 2. operational condition of the radial turbo-expander and grid number for analysis rotor turbo-expander parameter value inlet temperature (k) 353-423 mass flow (kg/s) 0.1-1.0 outlet pressure (atm) 1.0 outlet temperature (k) 313-373 table 3. power and efficiency for rotor radial turbo-expander with different grid number fluids' parameter model 1: 20,000 mesh model 2: 100,000 mesh model 3: 250,000 mesh fluid: r123 (20,000 rpm) torque (nm) 0.32 0.35 0.36 power (kw) 6.56 7.08 7.21 efficiency 0.63 0.64 0.65 time consuming 6 minutes 30 seconds 11 minutes 56 seconds 28 minutes 5 seconds fluid r134a (20,000 rpm) torque (nm) 0.44 0.47 0.48 power (kw) 7.94 8.60 8.53 efficiency 0.63 0.64 0.65 time consuming 6 minutes 21 seconds 11 minutes 54 seconds 27 minutes 30 seconds table 4. power and efficiency for rotor radial turbo-expander with different grid number model time consuming (minutes) iteration power (kw) k-epsilon (k-ɛ) 28 200 6.1 sst 28 200 7.2 m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 44 (a) (b) figure 4. velocity contour for turbulence models: (a) k-epsilon; (b) shear stress transport (sst) m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 45 (a) (b) figure 5. flow prediction at meridional plane for rotor radial turbo-expander at 15,000 rpm using: (a) r123; (b) r134a m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 46 (a) (b) figure 6. flow prediction for rotor radial turbo-expander at 15,000 rpm using: (a) r123; (b) r134a m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 47 (a) (b) figure 7. flow prediction at trailing edge (te) for rotor radial turbo-expander at 15,000 rpm using: (a) r123; (b) r134a m. arifin et al. / j. mechatron. electr. power veh. technol 06 (2015) 39–48 48 v. conclusion this paper present the geometry calculation of a small radial turbo-expander for small organic rankine cycle system. the performances of the turbo-expander have been evaluated using geometry and 3d numerical analysis method. in geometry analysis, the performance estimation is calculating in iterative loop. the result shows total efficiency-to-static (ηts) for r134a is 0.71 and r123 is 0.66. in simulation using 3d numerical can be concluded that the higher number of grid will give better and accurate results. it is also suggested to use sst models for the numerical analysis to give higher power output. however this results has to be verified in the experimental study. from the two working fluids use in the analysis, r134a gives better performance. at mass flow rate 0.4 kg/s, 15,000 rpm, inlet pressure 5 bar, and inlet temperature 373 k, the expander with r134a produces 6.7 kw power. on the other hands r123 only produces 5.5 kw, respectively. acknowledgement authors would like to express gratitude to all the members of the research centre for electrical power and mechatronics indonesian institute of sciences and all members of thermodynamics laboratory of faculty of mechanical and aerospace engineering, institute technology of bandung, for any assistance that have been given. references [1] t. c. hung, "waste heat recovery of organic rankine cycle using dry fluids," energy conversion and management, vol. 42, pp. 539-553, 2001. [2] z. gnutek and a. bryszewska-mazurek, "the thermodynamic analysis of multicycle orc engine," energy, vol. 26, pp. 10751082, 2001. [3] d. manolakos, et al., "experimental evaluation of an autonomous lowtemperature solar rankine cycle system for reverse osmosis desalination," desalination, vol. 203, pp. 366-374, 2007. [4] a. schuster, et al., "energetic and economic investigation of organic rankine cycle applications," applied thermal engineering, vol. 29, pp. 1809–1817, 2009. [5] m. kanoglu, "exergy analysis of a dual-level binary geothermal power plant," geothermics, vol. 31, pp. 709–724, 2002. [6] m. talbi and b. agnew, "energy recovery from diesel engine exhaust gases for performance enhancement and air conditioning," applied thermal engineering, vol. 22, pp. 693–702, 2002. [7] m. imran, et al., "thermo-economic optimization of regenerative organic rankine cycle for waste heat recovery applications," energy conversion and management, vol. 87, pp. 107–118, 2014. [8] l. pan and h. wang, "improved analysis of organic rankine cycle based on radial flow turbine," applied thermal engineering, vol. 61, pp. 606–615, 2013. [9] n. c. baines, "radial turbine design," in axial and radial turbines, ed: concepts eti, inc., 2003, pp. 199–327. [10] c. a. m. ventura, et al., "preliminary design and performance estimation of radial inflow turbines: an automated approach," journal of fluids engineering, vol. 134, pp. [031102-1]-[031102-13], 2012. [11] a. j. glassman, turbine design and application: nasa, 1994. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 1-10, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.1-10 experiment and analysis of car alternator for wind turbine application pudji irasari research centre for electrical power and mechatronics – indonesian institutes of sciences komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, west java 40135, indonesia pudji.irasari@lipi.go.id received: february 1st, 2011; revised: february 8th, 2011; accepted: april 8th, 2011; published online: july 7th, 2011 abstrak makalah ini membahas eksperimen dan analisis untuk mengetahui kelayakan alternator mobil sebagai generator turbin angin. eksperimen dilakukan dua kali. eksperimen pertama adalah karakterisasi alternator untuk menentukan rasio transmisi mekanik. dalam eksperimen ini alternator diputar oleh mesin bubut dan daya keluarannya digunakan untuk mengisi baterai. dalam eksperimen kedua, alternator diintegrasikan dengan baling-baling dan mengujinya sebagai satu kesatuan sistem. simulasi kecepatan angin dilakukan menggunakan terowongan angin. dalam kedua eksperimen tersebut pembangkitan listrik alternator dilakukan dengan metoda fixed excitation current. korelasi antara karakteristik alternator dengan tip speed ratio menghasilkan rasio transmisi mekanik sebesar 1 : 3. hasil pengujian menunjukkan bahwa efisiensi alternator sekitar 50% dan cut-in wind speed (setelah perhitungan koreksi) adalah 6.35 m/s. kata kunci: alternator, mobil, fixed excitation current, turbin angin. abstract this paper discusses experiment and analysis to find out the feasibility of a car alternator to be used as a generator for wind turbine. the experiment was conducted twice. the first experiment was to characterize the alternator to determine the mechanical transmission ratio. in this experiment the alternator was driven by a lathe machine and its output power was supplied to charge a battery. in the second experiment the alternator was integrated with the turbine blades and they were tested as a unit system. in both experiments, the electric generation of alternator was executed with fixed excitation current method. the correlation between the alternator characteristic and the tip speed ratio gives the mechanical transmission ratio of 1 : 3. the experiment results show that the efficiency of alternator is around 50% and cut-in wind speed (after correction) is 6.35 m/s indicating that alternator is not feasible for wind turbine system application. key words: alternator, car, fixed excitation current, wind turbine. i. introduction the electrification ratio of indonesia is 66% [1]. this coerces part of the society to fulfill their electricity self-reliance by utilizing surrounding potential energy sources. one of the attractive energy sources is wind energy since almost all of the components of small wind turbine can be easily made by small local workshops. among the components that are demanded to be found in local market yet bear high cost for still being imported is low speed generator. this condition has driven people to make use of any available and cheap generator types. one of them is car alternator. discussions on the feasibility of car alternator for wind energy system are still going on. some conducted researches utilizing car alternator as generator in wind turbine system are [2][3][4]. research [2] used a windpro2004 wind turbine that could generate 163w electric power with wind speed around 9m/s and the selected gear ratio was 1:4. in the generator section, an excitation supply was provided as the generator exceeds a pre-determined speed (rpm) preserving the battery from draining unnecessarily. the field controller circuit automates this function. when the battery is fully charged and the rotor exceeds the safe rpm, a braking system is activated automatically by using a resistive dump load. under the experimental conditions the wind turbine could generate 18.75 kwh per month at 4.8m/s of average wind speed. in research [3] the car alternator is mechanically coupled to the shaft of a squirrel cage induction motor, which is controlled through an ac drive that simulates the variable speed wind. the old rectifier diode array of the alternator was replaced with the new one that not http://dx.doi.org/10.14203/j.mev.2011.v2.1-10 experiment and analysis of car alternator for wind turbine application (pudjiirasari) jmev 02 (2011) 1-10 2 figure 1. characteristic of current – speed measured from three car alternators. only providing a basic dc output but also incorporating both a field and an output voltage regulators in the same case. from the tests performed, 87% of overall system efficiency was obtained. this achievement is very good but there is no information on how much power consumed by the controller. the rotor type used in [4] was of double step savonious rotors. in order to obtain power at low speed, the conventional car alternator winding was modified (rewound). the built prediction data for the prototype on mechanical power, rotational speed, nominal wind speed, and efficiency are 81 w, 386 rpm, 10 m/s and 29%, respectively. this paper will discuss the feasibility of car alternator for wind turbine application with fixed excitation current. ii. theory a. car alternator it is already known that a car alternator usually starts producing electric power at a high speed which is around 1000 rpm [2][4][5]. however, an experimental work carried out in [3] shows the possibility for generating energy at low rotational speed, as illustrated in fig. 1. in principle, alternators work similarly to generator, which is converting mechanical energy into electrical energy. in indonesia, the term of “alternator” is frequently related to the automotive application while “generator” is for electric power plant. knowing the alternator characteristic is a very important point, particularly to match wind turbine and alternator speed in order to obtain the smallest gearbox ratio. fig. 1 has a drawback since it does not present complete information particularly on the magnitude of the excitation current. in an automotive system, excitation current is drawn automatically by a voltage regulator. the lower the battery level, the higher the excitation current drawn by the regulator which leads to higher reverse torque. the working principle of car alternator in more detail can be explained with the help of fig. 2. when the key is turned on, current from the ignition switch flows to the rotor through voltage regulator. since the rotor is spinning, a pair of brushes that makes constant contact with two slip rings on the rotor shaft is required. this causes the rotor to become magnetized and the alternator is producing alternating current in the stator. afterward, the alternating current has to be converted to direct current by using a series of 6 diodes that are mounted in a rectifier assembly. the direct current leaves the rectifier through the b terminal. connected to the b terminal of the alternator is a fairly heavy wire that runs straight to the battery. current generated by the ignition switch and flows in the field coil, is usually called as “field current” or “excitation current”. the voltage figure 2. typical alternator circuit. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 1-10, 2011 p-issn 2087-3379 3 regulator monitors the voltage coming out of the alternator and, when it reaches a threshold of about 14.5 volts, the regulator reduces the excitation current in the rotor to weaken the magnetic field. when the voltage drops below this threshold, the current flows to the rotor is increased. there is another circuit in the alternator to control the charging system warning lamp that is on the dash. part of that circuit is another set of diodes mounted inside the alternator called the diode trio. the diode trio takes current coming from the three stator windings and passes a small amount through three diodes so that only the positive voltage comes through. after the diodes, the wires are joined into one wire and sent out of the alternator at the l connection. it then goes to one side of the dash warning lamp that is used to indicate when there is a problem with the charging system. the other side of the lamp is connected to the run side of the ignition switch. if both sides of the warning lamp have equal positive voltage, the lamp will not light. remove voltage from one side and the lights on to inform there is a problem. for wind power application, the rising of excitation current will be sensed as a shocking break that could stop the blades from rotation and, when it frequently happens, damage the mechanical components such as bearing and shaft. therefore, in order to have smooth operation, it is better to set the excitation current at a certain value. an experiment is, therefore, required to find out the most appropriate excitation current from the torque and rotation point of views. b. tip speed ratio in this research, tip speed ratio is one of the main parameters to determine gearbox ratio. the unavailability data of the tip speed ratio of the wind turbine used is approached using the graph showing a relationship between power coefficient cp and tip speed ratioλ, as illustrated in fig. 3. the wind turbine used is of three-blade types, so according to fig. 3, the corresponding tip speed ratio is in the range of 5 – 11. iii. experiment a. alternator performance test ideally, a generator or a car alternator laboratory performance test is conducted by employing a set of ac or dc motor with speed controller as performed in [3][8][9]. however, since such experiment set-up was not available in the laboratory, a lathe machine was utilized instead. this machine has speed setting of 220, 300, 400, 540, 720, 980, 1300 and 1800 rpm which means that the experiment speed variations are very limited. the experiment circuit is illustrated in fig. 4. the driver m is a lathe machine coupled directly with the alternator g. the alternator g has no technical specification except it is from magnetimarelli brand and for use in car chrysler/sinca. the dc power supply is functioned as excitation current injector to the alternator g so it can generate electricity. the higher the excitation current, the higher the output power will be. all of the output power is flowed to the battery. at the beginning of the experiment the excitation current should be set at figure3. the graph of power coefficient cp vs. tip speed ratio λ. experiment and analysis of car alternator for wind turbine application (pudji irasari) jmev 02 (2011) 1-10 4 a certain value and the battery should be fully charged (±13v). as the experiment started, the battery is discharged by turning on the load (variable lamps), and at the same time the battery is charged by the alternator. the load is increased randomly until the battery voltage is down to 12v. this procedure is repeated with different excitation current and speed setting. since generally car alternator starts generating electricity at around 1000 rpm, this speed is set to become the minimum speed for this experiment. the power generation method of alternator under constant field excitation has also been carried out within [8], giving better efficiency than internal regulator the other parameter measurement to obtain is the torque. the experiment set-up for torque measurement is shown in fig. 5, based on the method described in [10]. the shaft of alternator and lathe machine are coupled so that the alternator’s body could hang freely (fig. 5(a)). the imbalanced position of alternator due to fixation gives some force at no load condition (fig. 5(b)) f0 = 0.6 n. therefore, the measured force, fm, should be subtracted by this value to obtain the net force, f. the length of the arm (l) is 0.26 m. the recording of the torque is done along with the other electrical parameters, which are current and voltage at every load set. b. alternator performance test there are a lot of data obtained from the alternator performance test but only one experiment setting, which is one speed with two excitation current, presented here to give a figure of mechanical power and efficiency calculations. furthermore, the other data can be similarly calculated. the experiment result is shown in table 1. torque is calculated using equation [11]: 𝑇𝑇 = 𝑙𝑙 ∙ 𝐹𝐹 (1) where l = the length of cantilever, and f = the net force obtained from 𝐹𝐹 = 𝐹𝐹𝑚𝑚 − 𝐹𝐹0 (2) for simplicity, only the measured force presented in table 1, which is the net force directly involved in the calculation of efficiency. mechanical power can be found as [12] 𝑃𝑃𝑚𝑚𝑚𝑚𝑚𝑚 ℎ. = 𝑇𝑇 ∙ 𝜔𝜔𝑚𝑚 = 𝑇𝑇 ∙ 2𝜋𝜋𝑛𝑛𝑎𝑎𝑙𝑙𝑎𝑎 60 (3) where nalt = rotational speed of alternator in rpm. efficiency is obtained from: 𝜂𝜂 = 𝑃𝑃𝑚𝑚𝑙𝑙𝑚𝑚𝑚𝑚𝑎𝑎 . 𝑃𝑃𝑚𝑚𝑚𝑚𝑚𝑚 ℎ . × 100% (4) figure4. circuit diagram of experiment. (e) figure 5. torque measurement set-up, (a) the position of alternator onthe lathe machine, (b) unbalance position at no load condition, (c) doing measurement using cantilever and newton meter, (d) measuring position, (e) the alternator and lathe machine used in the experiment. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 1-10, 2011 p-issn 2087-3379 5 table 1. alternator characteristic at 1,070 rpm and excitation current 1.2a. speed, nalt (rpm) excitation current (a) voltage (v) current (a) f (n) t (nm) pmech. (w) pelect. (w) η (%) 1070 1.0 12.44 2.04 1.5 0.525 58.83 25.38 43.14 12.36 2.27 1.8 0.630 70.59 28.06 39.75 12.23 2.56 1.9 0.665 74.51 31.31 42.02 12.07 2.86 2.0 0.700 78.44 34.52 44.01 1.2 12.36 5.70 3.4 1.190 133.34 70.45 52.84 12.33 5.80 3.5 1.225 137.26 71.51 52.10 12.23 6.00 3.5 1.225 137.26 73.38 53.46 12.04 6.24 3.6 1.260 141.18 75.13 53.21 figure6. electrical power vs. excitation current at maximum efficiency. figure7. torque vs. excitation current at maximum efficiency. figure8. maximum efficiency at diverse rotational speed and excitation current. experiment and analysis of car alternator for wind turbine application (pudji irasari) jmev 02 (2011) 1-10 6 at every period of experiment there is always an achieved maximum efficiency, like 44.01% and 53.46% in table 1. the theoretical efficiency of a conventional car alternator is around 40 – 60% [2][8] and until 70% for nowadays alternator [13]. moreover, the alternator characteristics represented by its all maximum efficiencies at every excitation current and speed setting are presented in fig. 6 – 8. fig. 6 & 7 show that with the same excitation current, the electrical power at 1850 rpm is always higher than the others. to obtain higher electrical and mechanical power with the same speed, the excitation current should be enhanced. however, referring to eq. (3), the increase of mechanical power means the torque also becomes higher. for wind turbine application, this causes the increase of required wind speed to produce the same power output and of cut-in wind speed. while if the excitation current is small, high speed is needed to reach big power output. it can be achieved by installing a high transmission ratio which could lead to higher transmission losses so the wind turbine becomes inefficient. by implementing a controlled excitation current, some of the energy of the battery will be drawn by the controller, the delivered energy to consumers therefore is diminished. in this research, the excitation current is not controlled but is set at a certain point. fig. 8 shows the efficiency graph of the generated power displayed in fig. 6 & 7. unlike the power curve which tends to ascend, the efficiency curve shows little increase until a certain point but then almost flat and tends to decrease due to core saturation [14]. c. alternator characteristic – tip speed ratio correlation it is already known that the ratio of mechanical transmission will affect directly to the wind turbine system performance. the higher the ratio, the higher the starting torque and the maximum power reached. the other way will be if the ratio is lower. since in wind turbine system the mechanical transmission connecting rotor blades and electric generator in which each has its optimum characteristic that should be maintained, therefore, the ratio of mechanical transmission should be able to meet as lowest cut-in wind speed or starting torque as possible and as highest maximum power as possible in this research, the mechanical transmission employed is pulley belt for cost and ease of manufacture considerations. the calculation of pulley ratio is approached with assuming: 1. the tip speed ratio λ is in the range of 5 – 11 (fig. 3) 2. the wind speed vwind is between 3 – 6 m/s (the most average wind speed in indonesia’s regions [15]) the correlation between wind speed and tip speed ratio is expressed as [12] 𝜆𝜆 = 2∙𝜋𝜋∙𝑅𝑅∙𝑛𝑛𝑤𝑤𝑎𝑎 60∙𝑉𝑉𝑤𝑤𝑤𝑤𝑛𝑛𝑤𝑤 (5) with r = radius of rotor blade = 0.85 m. eq. (5) shows the reverse correlation between λ and vwind and the proportional correlation of the shaft speed n and λ. however, from fig. 2 and eq. (5), it cannot be determined surely the value of lambda and cp since they always change with the change of the wind. therefore it is made a hypothesis: “if the wind speed increases the rotation of the wind turbine will also increase and the extracted power will increase as well. the increase of power causes the increase of the load (current flowing to the battery), which will generate an adverse torque to the rotor shaft and consequently decreases the rotation of the wind turbine so that it will always go back to the maximum value of cp”. hence, the correlation among them can be illustrated as shown in fig. 9. figure 9. correlation among wind speed, alternator speed, lambda, and power coefficient. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 1-10, 2011 p-issn 2087-3379 7 the minimum blade shaft speed nwt is obtained by substituting the minimum value of λ and vwind into eq. (5): 𝑛𝑛𝑤𝑤𝑎𝑎 (min ) = 60 ∙ 11 ∙ 3 2 ∙ 𝜋𝜋 ∙ 0.85 = 370.73 𝑟𝑟𝑟𝑟𝑚𝑚 the minimum gearbox ratio is found as: gearbox ratio (min) = 𝑛𝑛𝑎𝑎𝑙𝑙𝑎𝑎 (𝑚𝑚𝑤𝑤𝑛𝑛 ) 𝑛𝑛𝑤𝑤𝑎𝑎 (𝑚𝑚𝑤𝑤𝑛𝑛 ) = 1000 370 .73 = 2.697 similarly, the calculation is conducted for the maximum gearbox ratio, yielding 5.3 with the blade shaft rotation of 337 rpm. from both options, the smaller gearbox ratio (rounded up to 3) is chosen by considering the transmission losses. refering to the alternator experiment result and the pulley ratio calculation, the excitation current is set to 1.6 a and little higher at 1.7 a in order to gain big power output. the starting torque is not taken into account as the system will be simulated using wind tunnel. d. wind turbine performance test after getting the alternator characteristic and choosing the suitable transmission ratio, the alternator is then integrated to the wind turbine to be tested as a unity system. the experiment method for wind turbine system is similar to that of the alternator except the lathe machine is substituted by the wind tunnel. the wind turbine experiment set-up is illustrated in fig. 10. relating to fig. 8, a dc power supply is employed to inject excitation current to the alternator with the magnitude of 1.6 a and 1.7 a for each experiment. the load is battery with initial voltage about 12v. the experiment is started by blowing wind from wind tunnel, turning the rotor blades. the data are recorded when the blade rotation is considered stable, covering the rotor shaft speed, battery current and voltage. the wind speed is gradually increased by 0.5 m/s until the battery voltage has reached around 13v. at every speed setting, the same data is recorded. the considered maximum wind speed is when the system becomes unstable. at this point the experiment is ended to avoid damage. (a) (b) (c) figure 10. small wind system experiment set-up (a) experiment configuration, (b) blades and alternator set-up, (c) wind turbine and wind tunnel set-up. a v + dc power supply wind tunnel battery speed meter experiment and analysis of car alternator for wind turbine application (pudji irasari) jmev 02 (2011) 1-10 8 e. the experiment drawback the experiment drawback is that the dimension of wind tunnel is smaller than that of the rotor blades. this causes not all of blade area swapped by the wind blown from the tunnel. both dimensions are illustrated in fig. 11. the power of the wind is calculated using [16]: 𝑃𝑃𝑤𝑤 = 1 2 ∙ 𝜌𝜌 ∙ 𝐶𝐶𝑟𝑟 ∙ 𝜋𝜋 ∙ 𝑅𝑅2 ∙ 𝑉𝑉𝑤𝑤𝑤𝑤𝑛𝑛𝑤𝑤 3 (6) where ρ = air density (1.25 kg/m3), r = blade radius = 850 mm, vwind = wind speed, cp = power coefficient. due to the mismatch dimension, the swapped blade area (πr2 in eq. (6)) is amended by the wind tunnel area. the ratio of the ideal wind power generated by wind turbine pwt to the wind power after being corrected by wind tunnel area pw(experiment) is: 𝑃𝑃𝑊𝑊𝑇𝑇 𝑃𝑃𝑊𝑊(𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 ) = 1 2� 𝜌𝜌𝑉𝑉𝑤𝑤𝑤𝑤𝑛𝑛𝑤𝑤 3 𝑚𝑚𝑟𝑟(𝜋𝜋0.852 ) 1 2� 𝜌𝜌𝑉𝑉𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 3 𝑚𝑚𝑟𝑟(0.8 ∙ 1) = 2.27 0.8 = 2.8 figure 11. the mismatch dimension between the wind turbine and wind tunnel. the ratio of 2.837 means that with the same wind speed, the power generated by actual wind speed is higher than that of the wind tunnel (experiment). the power correction does not take into account the blade aerodynamic factor. to find out the magnitude of the equity of terrain wind speed, the approach calculation is as follows: 𝑃𝑃𝑊𝑊𝑇𝑇 = 𝑃𝑃𝑊𝑊(𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 ) 1 2 ∙ 𝜌𝜌 ∙ 2.27 ∙ 𝑉𝑉𝑤𝑤𝑤𝑤𝑛𝑛𝑤𝑤 3 = 1 2 ∙ 𝜌𝜌 ∙ 0.8 ∙ 𝑉𝑉𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 3 𝑉𝑉𝑤𝑤𝑤𝑤𝑛𝑛𝑤𝑤 = 0.706 ∙ 𝑉𝑉𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 (7) substituting vwind into eq.(6) 𝑃𝑃𝑤𝑤 = 1 2 ∙ 𝜌𝜌 ∙ 𝐶𝐶𝑟𝑟 ∙ 𝜋𝜋 ∙ 𝑅𝑅2 ∙ 0.706 ∙ 𝑉𝑉𝑚𝑚𝑒𝑒𝑟𝑟𝑚𝑚𝑟𝑟𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑎𝑎 3 iv. result and discussion the graphs of the power curve and wind turbine efficiency are illustrated in fig. 12. the displayed wind speed is terrain wind speed calculated using eq. (7). fig. 12 shows that there is no significant difference between the excitation current 1.6a and 1.7a in yielding the power; even the two curves are close together. the cut-in wind speed arises at about 6.35 m/s, much higher than that of the commercial wind turbine which is in the range of 2.5 – 3 m/s. if the cut-in wind speed is required to be smaller, then the excitation current should be decreased. however, it will reduce the achieved maximum power, as shown in fig. 6. if the efficiency of alternator and mechanical transmission are assumed to be 55% and 90% [17] respectively then the efficiency of the wind system is 49.5%. figure 12. the experiment result of the capacity of the wind turbine. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 1-10, 2011 p-issn 2087-3379 9 table 2. the rotation of alternator and blade shaft of alternator. v (m/s) excitation current 1.7a 1.6a nwt(rpm) nalt(rpm) nwt(rpm) nalt(rpm) 6,35 320 960 320 960 6,71 330 990 330 990 7,06 340 1020 340 1020 7,41 350 1050 360 1080 7,77 360 1080 360 1080 8,12 360 1080 375 1125 8,47 360 1080 380 1140 by using pulley belt ratio of 1 : 3, the rotation of the blades and alternator are shown in table 2. as predicted, the car alternator starts generating electrical power at 960 rpm or close to 1000 rpm. some data in table 2 show that the increase of wind speed is not always followed by the increase of the alternator rotation. nevertheless, the output power of alternator (fig. 12) goes up. it means that the reverse torque generated by the alternator also raises, preventing alternator to rotate faster. v. conclusion and recommendation the experiment results show that the car alternator with fixed excitation current can be implemented for wind turbine (up to 1 kw) but its efficiency is very low (around 50%) and it starts producing electric power at high speed (approximately 1000 rpm). the output power can be improved by enhancing the transmission ratio or excitation current but it will increase the starting torque and cut-in wind speed at once in consequence. therefore, the use of alternator for wind turbine application is not recommended. references [1] anonim, terbebas dari pemadaman bergilir, rasio elektrifikasi masih 66%, [online], available: http://www.kabarbisnis.com/energi/kelistri kan/2813532terbebas_dari_pemadaman_b ergilir__rasio_elektrifikasi_masih_66_.ht ml. accessed on 28 january 2011 [2] s. whid, l.r. peiris, p. laan, sandagiri. ca, siriwardena. kap, introduction of car alternators for small scale wind power generation, [online], available: http://www.elect.mrt.ac.lk/ug_papers/p09_ oct04.pdf, accessed on 25 march 2011 [3] h. fernández, a. martínez, v. guzmán and m. giménez. (2004, april). wind turbine generation system implemented with a car alternator for use in isolated locations. presented at icrepq. [online]. available: http://www.icrepq.com/ponencias/4.28 8.fernandez.pdf [4] j.-l. menet. (2004). adouble-step savonius rotor for local production of electricity: a design study, renewable energy29, pp. 1843–1862. [5] d.j. perreault, v. caliskan, a new design for automotive alternators, [online], available: http://leesweb.mit.edu/lees/dperreault/conferencepa pers/cpconvergence00p583.pdf, accessed on 26 march 2011. [6] c. ofria, a short course on charging systems [online], available: http://www.alternatorparts.com/understand ing_alternators.htm, accessed on february 2011 [7] p. irasari, small wind system, master thesis, carl von oszietsky university. oldenburg. 2003. germany. [8] d.m. whaley, w.l. soong and n. ertugrul. (2004, september). extracting more power from the lundell car alternator. presented at aupec [online]. available: http://itee.uq.edu.au/~aupec/aupec04/paper s/paperid82.pdf [9] a. gálvez, m. lejárraga, j. s. artal, a. usón and f.j. arcega. (2003, april). recycling of small electrical machines and its applications for low cost wind turbines, presented at icrepq [online]. available: http://www.icrepq.com/pdfs/galvez393.pd f [10] m.b. robert, w. grove, n.h., “dynamometer torque arm and dynamometer assemby,” us patent5,370,003,dec. 6, 1994 experiment and analysis of car alternator for wind turbine application (pudji irasari) jmev 02 (2011) 1-10 10 [11] f. sahin, design and development of a high-speed axial-flux permanent-magnet machine, ph.d thesis, technische universiteit eindhoven, 2001, netherland. [12] n.s. çetin, m.a. yurdusev, r. ata and a. özdemir. (2005). assessment of optimum tip speed ratio of wind turbines, mathematical and computational appl., vol. 10, no. 1, pp. 147-154 [13] a.gimeno, g.friedrich, k.el-kadribenkara, “experimental and numerical evaluation of iron losses in a claw pole car generator,” in proc.icem xix, 2010, pp. 1 – 6. [14] e.s. hamdi, design of small electrical machines, england: john wiley & sons, 1994, pp. 2 – 11 [15] a. hardoko and soeripno. (2008, november). prospect of wind energy development in indonesia. [japan – indonesia symposium & expo] [16] t. burton, d. sharpe, n. jenkins and e. bossanyi, wind energy hand book, england: john wiley & sons, 2001, pp. 44 – 46 [17] energy loss and efficiency of power transmission belts. carlisle power transmission products, inc. atlanta, georgia, third world energy engineering congress. [online]. available: http://www.cptbelts.com/pdf/misc/energy_ loss_and_belt_efficiency.pdf, accessed on 5 april 2011 mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.123-128 braking system modeling and brake temperature response to repeated cycle zaini dalimus a,* a electrical engineering department, andalas university kampus unand limau manis padang, indonesia received 24 april 2014; received in revised form 10 november 2014; accepted 10 november 2014 published online 24 december 2014 abstract braking safety is crucial while driving the passenger or commercial vehicles. large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. if the braking system fails to work, road accident could happen and may result in death. t his research aims to model braking system together with vehicle in matlab/simulink software and measure actual brake temperature. first, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. next, arduino based prototype brake temperature monitoring was developed and tested on the road. from the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle. keywords: braking, kinetic energy, brake characteristic, arduino. i. introduction driver performs braking to safely decelerate or stop the vehicle. the braking time depends on initial speed, vehicle mass, road condition and brake demand. in that short time, vehicle kinetic energy is transformed into heat energy in roadtire contact and brake contact area. at tyre slip rate of 10%, about 90% of heat energy is dissipated in friction brakes. braking 1470 kg vehicle from 98.4 km/h to 1 km/h in 15 seconds caused the brake temperature to rise to 157°c [1]. in the development stage, friction brake is subjected to fade test. a cycle is an accelerated period of 40 seconds and followed by deceleration period of 5 seconds. after 15 cycles, it was found that the disc brake temperature reached 510°c [2]. the acceleration time is not sufficient to cool the disk through conduction, convection and radiation processes. computer simulation known as finite element method (fem) was used to predict the temperature distribution across the disc brake and showed good results compared to lab test. zhang and meng [3] used fem model to predict disc transient temperature field and normal stress in radial with asymmetrical outer and inner disc thickness were considered. the fem results were then validated through experiment using thermocouples and non-contact displacement sensors. however, vehicle dynamic was not considered in calculating frictional interface pressure and total normal force. heat crack appears in the brake rotor surface as a result from repeated thermal stresses, compressive yield and tensile residual stress cycle [4]. good brake rotor material has shorter average crack length for same number of stress cycles. cho et al. [5] show that friction coefficient decreases noticeably when the temperature rises over 200°c, resulting in generated brake torque reduction hence increasing stopping distance. the initial brake temperature was 100°c and the test lasted for 10 minutes [5]. one way to improve brake performance is maximizing convective cooling from the rotor to surrounding airflow. nutwell and ramsay [6] developed cfd (computational fluid dynamics) model of disc brake assembly installed on an inertia brake dynamometer. combined with physical test, the effects of cooling air flow, braking energy input rate, and rotational speed on brake operating temperatures can be evaluated with the proposing cfd model [6]. however, the thermal load was given, not derived from real braking condition obtained from simulation or experiment. * corresponding author. phone: +62-81266224644 e-mail: zzaini21@gmail.com http://dx.doi.org/10.14203/j.mev.2014.v5.123-128 z. dalimus / mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 124 ii. brake system elements the basic braking system components in a conventional passenger car are brake pedal, linkage, master cylinder, vacuum booster, pipes, disc or drum brake assembly including slave cylinder(s), brake pads or shoes, and rotor (disc or drum). the brake pedal is a lever that amplifies the foot force f generated by the driver. force on the pushrod is: (1) where lp is brake pedal length. since front chamber in figure 1 is held at lower pressure either by engine inlet depression or a “vacuum” pump (e.g. on diesel engines), additional force is produced. when atmospheric air at pressure enters the rear chamber, the pressure difference generates a force on the master cylinder piston given by: ( ) (2) where a1 is cross-sectional area of power piston and the brake booster ratio is defined as: (3) the booster ratio of modern passenger cars is typically between 4 and 9. the force on the master cylinder primary piston + and the generated pressure is: (4) where a2 is cross-sectional area of brake booster. this equation does not include spring forces and seal friction forces in the master cylinder. using the simplified cross-section of the master cylinder shown in figure 1, the generated hydraulic actuation line pressures are: (5) (6) where fmc is master cylinder force, amc is crosssectional of master cylinder and fk is spring force. therefore, the pressure in cylinder 2 is less than the pressure in cylinder 1 because of the reaction forces. seal friction includes both static and dynamic friction and it can be estimated from: ( ) ( ) (7) where and are static friction and dynamic friction coefficients, x is cylinder position and n is normal force. detailed explanation of above equations can be sourced in reference [7]. static friction force is the force required to move the piston hydraulic seal from the stationary state, and dynamic friction occurs between the seal and the cylinder bore when the seal is sliding. empirical brake model is preferred since non linearity due to vacuum booster operation is taken into account. the pedal force/travel characteristic curve has three distinct regions [6]. first, the pedal moves under constant applied force from the origin to a point called “jump-in”. second, the pedal moves further as the applied force increases up to a point called the “knee point”; beyond this point no additional boost force is available. these two points are shown as “a” point and “b” point in figure 2 and are typically about 25 and 300 n. third, the vacuum booster can’t longer amplify the applied pedal. this third state is dangerous if reached in practice since the driver will not be able to make any significant increase in hydraulic brake line actuation pressure and thus braking force. additionally, he/she will sense the absence of servo assistance and will interpret this as brake failure, leading to a loss of confidence and panic. figure 1. pressure generation in brake system [7] figure 2. pedal force/travel characteristic of a mid-size passenger car [8] figure 1. pressure generation in brake system [7] figure 2. pedal force/travel characteristic of a mid-size passenger car [8] z. dalimus / mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 125 the amount of braking torque that the friction brakes generate on one wheel is: (8) for a disc brake and drum brake: ( ) (9) where pline is brake caliper pressure, ac is crosssectional of brake caliper, is friction coefficient of brake pad, rdisk is radius of disk brake, sleading and strail are friction coefficient of leading and trail pads, and rdrum is radius of drum brake. for one axle, these torques are multiplied by 2 since the friction brake are identical. the frictional heat generated over a time period is: ∫ (10) where ωwheel is angular speed of wheel. iii. research methodology models of basic vehicle components such as engine, tyre and chassis have been available in matlab/simulink software. empirical model of brake pedal from other researchers were then programmed and combined with built-in matlab models to produce better vehicle models. so, this research does not propose a component model but integrates all available models. since the heat transfer model has not been included yet, predicted brake temperature cannot be determined. rather, road test was used to investigate temperature response of drum brake as performed in long repeated deceleration and acceleration cycle. iv. braking simulation with matlab/simulink a simulink model was then developed to predict the braking dynamics in terms of vehicle speed, wheel speeds, slip and weight transfer as shown in figure 3; the program parameters are listed in table 1. the tyre force is multiplied by 2 because both front tyres and rear tyres have the same braking response. the model input was either brake pedal travel or pedal force as plotted in figure 4. in simulink, both the pedal force and travel inputs were time-dependent series. it was figure 4. driver brake input (pedal travel and pedal force) figure 3. two-axle vehicle model z. dalimus / mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 126 assumed that these inputs changed linearly with time. both pedal travel and pedal force reached steady values of 31 mm and 56 n in 0.5 s. since the master cylinder pressure was modeled differently, the pressures generated were also different as shown in figure 5. with pedal force as input, the pressure rise after 0.25 seconds. in contrast, the pressure increases as the pedal travel rise, following a quadratic function. though the initial vehicle speeds of both models were the same at 60.4 km/h, different pressure profiles were resulted from the different braking times. the vehicle speed and its wheel translational speeds are shown in figure 6. it was found that the braking system with pedal travel as input had a braking time of 9.9 seconds, while with the pedal force as input was 9.7 seconds. these speeds exhibit low slip since they are close each other. compared to the front wheels, the slip of the rear wheels is smaller. brake force distribution k is defined as ratio between front braking torque to total braking torque and it can be derived from equation (8). assuming all the heat flows into the disc and are not conducted or convicted away, the absorbed energy is: (11) when 90% of kinetic energy is disposed in friction brake, energy transformation in one front wheel is given by: ( ) (12) the temperature rise prediction is found by substituting equation (12) into equation (11), taking into account the heat transfer mechanism by introducing factor 0.5 and there are two disk surfaces for each brake. using vehicle data in appendix, the front disk temperature rise was about 340°c. figure 5. hydraulic pressure generated in brake line table 1. parameters parameters description value m vehicle mass (kg) 1,500 a distance of front axle from the vertical projection point of vehicle cg onto the axle-ground plane (m) 1.008 b distance of rear axle from the vertical projection point of vehicle cg onto the axle-ground plane (m) 1.542 h height of vehicle cg above the ground (m) 0.569 cd aerodynamic drag coefficient (ns 2 m -1 kg -1 ) 0.346 a effective frontal vehicle cross-sectional area (m 2 ) 1.746 re effective rolling radius (m) 0.279 iw wheel-tyre assembly inertia (kg.m 2 ) 0.5 acf area of front wheel cylinder (m 2 ) 2*10 -3 acr area of rear wheel cylinder (m 2 ) 0.7*10 -3 rdisk disc mean radius, (ro + ri)/2 (m) 0.105 µpad friction coefficient of brake pad 0.4 mbrake brake assembly mass (kg) 15 cp the specific heat capacity of the brake disc material 586 figure 6. vehicle road and translational wheel speeds z. dalimus / mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 127 v. brake temperature monitoring a. hardware and software the sensing element is contact-less infrared thermometer mlx90614 that is able to measure object temperature between -70°c up to +380°c. this unit contains dsp chip performing signal conditioning and provides pwm and smbus methods for data communication. figure 7 shows the sensor pin definition that only needs two signals to communicate with other microprocessors. scl/vz is serial clock input to synchronize master and slave processors. pwm/sda is digital input and output. arduino is a single-board controller designed as open-source platform that facilitates programmer to develop applications. figure 8 shows arduino uno board containing atmel avr 16 mhz processor as the brain. there are 14 digital i/o pins and 6 analog input pins for connection with sensors and actuators. three type memories are available in the processor chip i.e. 32 kb flash, 2 kb sram and 1 kb eeprom. to load firmware to the board, ide arduino 1.0.5 was used in this research. pins connection between arduino boards as master processor with temperature sensor unit as slave processor is shown in table 2. to enable communication between them, a library named i2cmaster was included to arduino program as highlighted in figure 9. this hides low level communication from the programmer and makes reading temperature become easier. a led was connected to digital pin 6 and would blink when temperature reading of rear brakes exceeds 150°c. this warned the driver to stop the vehicle and let the brake to cool down. b. result of road test and analysis during the road test, temperature sensor was fitted on the rear brake of suzuki carry minivan as shown in figure 10. the sensor was positioned toward drum brake and able to measure outer surface of rear brake while driving in the padang city. next, garmin gps was used to record vehicle speed and later transferred to pc for further processing. both vehicle speed and rear brake temperature readings were plotted on same graph to show correlation between braking event with temperature rise. figure 8. arduino uno board figure 9. arduino code for i2c communication figure 10. sensor fitted in rear axle figure 7. pin definitions of mlx90614 thermometer [9] z. dalimus / mechatronics, electrical power, and vehicular technology 05 (2014) 123-128 128 the solid line in figure 11 is vehicle speed and dashed line is brake temperature profile. repeated deceleration and acceleration cycles were performed to generate increasing brake temperature. the initial brake temperature was 58°c and vehicle speed was 63.2 km/h. after 285 seconds driving, the brake temperature became 77.8°c and thus temperature rise is 19.5°c. with brake distribution ratio between front and rear brake of 3:1, the front brake temperature was predicted to be 116.6°c calculated from  5.19358  . then, the second road test was performed as shown in figure 12. it was confirmed that steady temperature increase was observed. after 380 seconds of driving, brake temperature rise was 23.7°c. vi. conclusion the hydraulic pressure generated in brake line depends on brake pedal characteristic. this means same brake pedal force applied in different cars produces different brake pressures. since the vehicle model was based on built-in matlab/simulink model and empirical model, the accuracy of result can be accepted. it was confirmed from the road test that repeated deceleration and acceleration cycles leads to increasing brakes temperature. references [1] l. liang, s. jiang and q. xuele, “study on vehicle braking transient thermal field based on fast finite element method simulation,” sae paper, no. 01-3945, 2005. [2] a.a. apte and h. ravi, “fe prediction of thermal performance and stresses in a disc brake system,” sae paper, no. 01-3558, 2006. [3] l. zhang and d. meng, “theoretical modeling and fem analysis of the thermomechanical dynamics of ventilated disc brakes,” sae paper, no. 01-0075, 2010. [4] j.yamabe, m. takagi, t. matsui, t.kimura and m. sasaki, “development of disc brake rotors for trucks with high thermal fatigue strength,” japan sae paper, no. 4017, 2002. [5] m. h choa, s. j. kimb, d. kimc, and h. janga, “effects of ingredients on tribological characteristics of a brake lining: an experimental case study,” journal of wear, vol. 258, 2005. [6] b. nutwell and t. ramsay, “modeling the cooling characteristics of a disk brake on an inertia dynamometer, using combined fluid flow and thermal simulation,” sae paper, no. 01-0861, 2009. [7] h. heisler, “advanced vehicle technology,” butterworth-heinemann, oxford, 2002. [8] j.w. zehnder, s.s. kanetker and c.a. osterday, “variable rate pedal feel emulator designs for a brake-by-wire system,” sae international, no 01-0481, 1999. [9] melexis, "mlx90614 family, single and dual zone infra red thermometer in to39," datasheet, february 2013. table 2. pins connection between master and slave processor arduino mlx90614 vcc vdd gnd vss digital 4 sda digital 5 scl figure 11. vehicle speed and rear brake temperature (first test) figure 12. vehicle speed and rear brake temperature (second test) kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 51-56, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.51-56 monitoring vibration of a model of rotating machine arko djajadi, arsi azavi, rusman rusyadi, erikson sinaga mechatronics department, faculty of engineering, swiss german university (sgu) edutown bsdcity, tangerang 15339, indonesia arko@sgu.ac.id received: april 27th, 2011; revised: may 3rd, 2011; accepted: june 15th, 2011; published online: july 7th, 2011. abstrak pergerakan mekanis benda atau perputaran mesin putar cenderung menyebabkan getaran tambahan. divais sensor getaran perlu dipasang untuk memonitor tingkat getaran secara kontinyu pada sebuah sistem yang melibatkan mesin putar. sensor ini diperlukan karena frekuensi dan amplitude getaran tidak dapat dengan mudah diukur secara kuantitatif hanya melalui pengamatan dengan mata manusia atau dengan rabaan tangan. apabila sinyal getaran dari sistem dengan mesin putar mengadung banyak derau, kemungkinan besar sistem tersebut mengalami gangguan yang dapat berlanjut menjadi kegagalan atau kerusaan lebih parah. dalam proyek riset eksperimen ini, sebuah model struktur telah dibuat untuk mensimulasikan getaran dan melakukan pengukuran dan monitor kinerja struktur dari segi tingkat getaran yang ditimbulkan pada saat putaran dengan kondisi seimbang dan tidak seimbang.dalam model terskala ini, sinyal luaran dari sensor getaran diproses awal dalam mikrokontroler dan dikirimkan hasilnya ke pc melalui saluran serial untuk diplotkan ke layar dengan menggunakan perangkat lunak yang dibuat dalam bahasa c. bentuk gelombang sinyal dapat dipakai untuk analisis getaran lebih lanjut.batas tingkat getaran maksimum dapat diatur dalam mikrokontroller yang memungkinkan sistem mesin putar dimatikan dalam kondisi getaran yang berlebihan untuk mengurangi tingkat kerusakan yang ditimbulkan. hasil dari eksperimen menunjukkan kesesuaian dengan teori bahwa kondisi tidak seimbang pada putaran mesin dapat menimbulkan getaran yang lebih besar dibandingkan dengan kondisi seimbang. penambahan dan pengurangan massa untuk penyeimbang dapat dilakukan untuk mendapatkan kondisi getaran yang lebih rendah. kata kunci: sensor getaran mekanik, mikrokontroler, perangkat lunak plot, model terskala, monitoring. abstract mechanical movement or motion of a rotating machine normally causes additional vibration. a vibration sensing device must be added to constantly monitor vibration level of the system having a rotating machine, since the vibration frequency and amplitude cannot be measured quantitatively by only sight or touch. if the vibration signals from the machine have a lot of noise, there are possibilities that the rotating machine has defects that can lead to failure. in this experimental research project, a vibration structure is constructed in a scaled model to simulate vibration and to monitor system performance in term of vibration level in case of rotation with balanced and unbalanced condition. in this scaled model, the output signal of the vibration sensor is processed in a microcontroller and then transferred to a computer via a serial communication medium, and plotted on the screen with data plotter software developed using c language. the signal waveform of the vibration is displayed to allow further analysis of the vibration. vibration level monitor can be set in the microcontroller to allow shutdown of the rotating machine in case of excessive vibration to protect the rotating machine from further damage. experiment results show the agreement with theory that unbalance condition on a rotating machine can lead to larger vibration amplitude compared to balance condition. adding and reducing the mass for balancing can be performed to obtain lower vibration level. keywords: mechanical vibration sensor, microcontroller, data plotter software, scaled model, monitoring. i. introduction vibration analysis [1] is one of the most important conditions monitoring techniques that are applied in real life, as more and more indispensible rotating machines are found in daily life. iso 13373-1: 2001 states that the monitoring condition and diagnostic of machines, in this case the vibration monitoring, must be seriously considered to avoid machine faults or defects [9]. most of the defects encountered in such rotating machinery give different vibration patterns where mostly faults can be identified by using vibration analysis techniques. the need of vibration monitoring in rotating machine is part of regular maintenance program to keep the machinery work properly and to avoid any damage. therefore, low cost vibration monitoring system to address such cases is justified and must be made available. vibration measurement system in this experimental research includes vibration sensors to convert mechanical movement to electrical http://dx.doi.org/10.14203/j.mev.2011.v2.51-56 monitoring vibration of a model of rotating machine (arko djajadi, arsi a, rusman r, erikson s) jmev 02 (2011) 51-56 52 signal, signal amplifiers to improve signal level, data acquisition device (i.e. adc of the microcontroller) and pc for signal analysis and display. usually machine vibrations are estimated by measuring the displacement, velocity or acceleration. displacement sensor is used for measurement of relative motion between two surfaces or objects (i.e. rotating shaft and machine base). mathematically, the velocity is time derivative of displacement, while the acceleration is time derivative of velocity [2]. in the system of the rotating machine, the measurement of vibration can be achieved by many different types of sensors, one of them is accelerometer [3][5][6][7][8]. a particular type of accelerometer commonly employed is piezoelectric accelerometers, while other type is thermal accelerometer. once the acceleration is measured, other vibration quantities can be calculated theoretically. the machine displacement or vibration speed can be calculated by integration of the acceleration signal. the vibration monitoring system as an embedded system to the rotating machines is represented in the following figure1. it consists of the rotating machine under inspection, the accelerometer attached as the vibration sensor, data acquisition system using microcontroller and pc for further analysis and plotting. in figure 1, first step, the rotating machine vibration will be measured by accelerometers with different axis orientation. next, the signal from the sensor will be sent to the microcontroller. in the microcontroller the data will be processed, then transferred to a computer via a serial communication, and the signal is plotted using c++ builder data plotter. in this experimental research project, a vibration structure including its embedded system is constructed in a scaled model with a purpose to simulate vibration and to monitor system performance in term of vibration level in case of rotation with balance and unbalance conditions. this can be used as a base of modelling and later on can be extended to many fields related to vibration system. figure 1. block diagram of the vibration monitoring system. serial communication te xtmotor microcontroller h-bridge e lcd display button push button pwm up button push button pwm down button push button dc motor leftright button push button on-off dc motor accelerometer (memsic2125) led warning indicator figure 2. system design overview. ii. system design all the system is controlled by atmega 8535 microcontroller. from the figure 2 there are four push buttons to control the system. the first push button is for increasing the speed of the motor. the second push button is for decreasing the speed of the motor. the last two push buttons are to control the direction of the motor and to turn on-off the motor. to control the direction of the motor, ems (embedded module system) 5a h-bridge is used. with this circuit the speed of the motor can be controlled by using pwm (pulse width modulation) technique. encoder is also required to know the speed of the motor, then lcd (liquid crystal display) is used for displaying the direction and the rpm (rotation per minute) of the motor. the vibration sensor (memsic2125 accelerometer) has two axes to sense the acceleration of the machine when the machine is rotated. the memsic 2125 is a low-cost thermal accelerometer capable of measuring tilt, collision, static and dynamic acceleration, rotation, and vibration with a range of ±3 g on two axes with output in 100 hz pwm having duty cycle proportional to acceleration [4]. the memsic2125 accelerometer contains a small heater. this heater warms a “bubble” of air within the device. when gravitational forces act on this bubble, it moves. this movement is detected by a very sensitive temperature sensor and the onboard electronics convert the bubble relative position to the g forces, and into pulse outputs for the x and y axis. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 51-56, 2011 p-issn 2087-3379 53 software is one of the most important parts in the system; it can be used for controlling all the system. in this experimental research, all the system is controlled by using atmega 8535 while for the data plotter it is using personal computer (pc) to show the data from measurement. first, the microcontroller is initialized. settings, such as lcd configuration, port initialization, baud rate value, are performed according to the requirement in the flow chart and its program listing. after initialization, the microcontroller is programmed to monitor all the inputs and gives control signal to output devices. the primary input in this system is the signal from accelerometer that must be acquired in the microcontroller. once the motor is turned on, the accelerometer will measure the vibration from the rotating machine. then, the data will be transferred to pc via serial to usb converter. in the pc, after the c++ builder data plotter program initializes some parameters, such as baud rate and communication port, data from the microcontroller are captured. the accelerometer data from microcontroller are processed, and converted in real time. then the data is plotted using the c++ builder data plotter software. the other microcontroller inputs are from the push buttons to control the system when the rotating machine was rotated. all the push buttons information will be display in the lcd, such as the rpm speed of the motor, the direction of the rotating machine and also the increase or decrease of the speed of the rotating machine. figure 3 shows the program flowchart of the system, within microcontroller (left) and within pc (right). the vibration data from the sensor will be processed in the microcontroller and displayed on the pc using c++ builder data plotter program. figure 4 shows the data plotter display. the system also provides the alarm signal to give a warning message and led (light emitting diode) warning to the user in case the system of the rotating machine has failures due to excessive vibration amplitude. iii. result of measurement the output signal from the memsic2125 accelerometer is pulse width modulated (pwm) signal. the pulse output from the memsic2125 accelerometer is set to 50% duty cycle at 0g. t1 is the output from xout or yout; t2 is calibrated to 10 milliseconds at 25°c (room temperature). t1 and t2 are used to get the g value using the g start port initialization lcd initialization display lcd default if push button on? motor off motor on read accelerometer port data transfer start serial port initialization data sampling plotting data plotting is left-right push button on? lcd display “right” lcd display “left” motor on to left. setting pwm motor on to right. setting pwm is push buton pwm++ on? lcd display “pwm++” is push buton pwm-on? lcd display “pwm--” pwm increased pwm decreased n y y n n y y data trasmiter n figure 3. the flowchart of the program. figure 4. c++ builder data plotter. formula (1) for the memsic2125, referring to figure 5 of its pulse modulated output. the formula for the acceleration a in g is [4]: a(g) = ((t1/t2) – 0.5)/12.5% (1) monitoring vibration of a model of rotating machine (arko djajadi, arsi a, rusman r, erikson s) jmev 02 (2011) 51-56 54 figure 5. memsic2125 pulse output. after several testing with the condition of the rotating machine, the results of data measurement g from the memsic2125 accelerometer are shown in table 1 and table 2. all the results of the acceleration have been converted to mg (for gravitation where 1g = 1000 mg = 9.81 m/s2). the unbalance condition from the rotating machine is achieved by adding the unbalance mass on the end of the rotating shaft. the unbalance location from the rotating machine is show in figure 6, several points along the shaft. the range of the sensor measurement in balance condition is between 251 mg and -244 mg (for x axis); between 72 mg and -40 (for y axis). meanwhile, unbalance condition is between 348 mg and -316 mg (for x axis); between 72 mg and -192 mg (for y axis), which is higher than in balance condition by a factor between 1.2 to 1.5 for x-axis and between 1 to 4.8 for y-axis in this case. figure 7 shows the data output of accelerometer in balance condition; it means no additional mass on the system of the rotating machine. further analysis of the graphs in figure 7 and 8, it is found that the maximum vibration amplitudes along the x-axis (along the shaft) during balance and unbalance conditions show similar patterns and increase in amplitude which mainly due to the inperfect rubbler coupling between the motor and the shaft. meanwhile, the maximum vibration amplitude along the y-axis (along the unbalance mass vertical to the shaft) during balance and unbalance conditions show significant increase in amplitude which mainly due to the simulated unbalance mass. the unbalance mass affects the vibration level along the y-axis more than along the x-axis, an expected behaviour. figure 6. unbalance mass. tabel 1. balance condition. x axis (mg) y axis (mg) -19 -32 176 16 251 64 -92 16 -196 64 168 0 -196 32 236 16 -172 24 -20 72 92 16 -244 64 -180 8 -75 -40 131 48 -59 -24 -4 64 43 72 -3 -40 24 -16 -19 -32 -204 56 table 2. unbalance condition. x axis (mg) y axis (mg) 180 48 -316 -64 -148 -40 203 24 -211 -80 -108 32 124 16 -168 -176 28 -192 -147 -168 124 40 -11 -64 -51 -88 -19 -88 348 -88 -147 -112 -152 56 -176 -152 -176 -136 187 72 11 144 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 51-56, 2011 p-issn 2087-3379 55 figure 7. accelerometer outputof balance condition experiment. figure 8. accelerometer output of unbalance condition experiment. due to the limitation of the accelerometer frequency resolution of the memsic2125, only its statistical amplitude is used to monitor vibration amplitude. figure 8 shows the data output of accelerometer in unbalance condition. it means there is additional mass on the system of the rotating machine. iv. conclusion the vibration monitoring system for a model of rotating machine demonstrates the effect of vibration as expected. the vibration from the machine in balance and imbalance conditions can be monitored, transmitted, and processed in real time. it means that the mechanical and electrical parts are working properly. the experiment is also able to successfully demonstrate the condition of the machine and its effect to vibration level. the low-cost memsic2125 accelerometer sensor that is implemented using g force formula gives g force digital output signal according to the vibration of the rotating machine. the memsic2125 accelerometer output signal is already readable by the microcontroller, because the output signal is in pwm signal. data are successfully sent to the software plotter via serial communication. overall, low cost system can be used to improve maintenance systems cost effectively, especially for older rotating machines without built-in vibration sensors. for higher quality output, new accelerometers with wider bandwidth (in range of khz) and higher g level (25 g or more) are highly favourable for detailed analysis. -300 -200 -100 0 100 200 300 1 4 7 10 13 16 19 22 a cc el er om et er v al ue (m g) time (s) x axis y axis -300 -200 -100 0 100 200 300 1 4 7 10 13 16 19 22 25 a cc el er om et er v al ue (m g) time (s) x axis y axis monitoring vibration of a model of rotating machine (arko djajadi, arsi a, rusman r, erikson s) jmev 02 (2011) 51-56 56 references [1] j. l. taylor, vibration analysis handbook, 1st ed., huston: gulf publishing company, 2008. [2] c.d. johnson, process control intrumentation technology, 8th ed., houston: pearson education, 2006,pp. 246257 [3] g. rizzoni, principles and applications of electrical engineering, 5th ed., new york: mcgraw-hill,2007, pp. 762 [4] datasheet: memsic2125 dual-axis accelerometer (#28017), v2.0 29 january 2009, pp.1-3, [online]. available: http://www.parallax.com [5] p. irasari, a.s. nugraha, m. kasim, “analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik”, journal of mechatronics, electrical power and vehicular technology, vol. 1, no.1. [6] didik r. santoso, “a simple instrumentation system for large structure vibration”, jurnal telkomnika, 20108.3.12.10.08, issn: 1693-6930, e-issn: 2087-278x, [online]. available: http://telkomnika.ee.uad.ac.id [7] yusuf yesilce, “effect of axial force on the free vibration of reddy–bickford multispan beam carrying multiple spring–mass systems”, journal of vibration and control 2010, [online]. available: http://jvc.sagepub.com/content/16/1/11 [8] wilfried reimche, ulrich südmersen, oliver pietsch, christian scheer, fiedrich (2003, june 2-6). “basics of vibration monitoring for fault detection and process control”, wilhelm bach university of hannover, germany, proceeding rio de janeiro rj – brasil [9] j michael robichaud, p.eng., “reference standards for vibration monitoring and analysis”, [online]. available: http://www.bretech.com/reference/referenc e%20standards%20for%20vibration%20m onitoring%20and%20analysis.pdf kata pengantar dewan editor daftar isi car alternator tip speed ratio alternator performance test alternator performance test alternator characteristic – tip speed ratio correlation wind turbine performance test the experiment drawback analisa keekonomian daftar pustaka / figure 5. memsic2125 pulse output. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology international peer reviewers prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering,universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135 indonesia estiko.rijanto@ lipi.go.id prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2,yogyakarta 55281, indonesia a.setiawan@ugm.ac.id dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia epit@eepis-its.edu dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id mailto:patko@uni-obuda.hu mailto:a.setiawan@ugm.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vi dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8 th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia trina.fizzanty@lipi.go.id dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia amsriasih@ugm.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2,yogyakarta 55281, indonesia masimam@jteti.gadjahmada.edu dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia moch019@lipi.go.id pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vii publication ethics and malpractice statement mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics lipi). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 viii 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ix author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with coma and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.67-74 proportional derivative active force control for “x” configuration quadcopter ni’am tamami a, *, endra pitowarno a , i gede puja astawa a a electronics engineering polytechnic institute of surabaya kampus pens, jalan raya its, sukolilo, surabaya 60111, indonesia received 21 august 2014; received in revised form 10 september 2014; accepted 16 september 2014 published online 24 december 2014 abstract this paper presents a stabilization control method for “x” configuration quadcopter using pdafc (proportional derivative active force control). pd is used to stabilize quadcopter, whereas afc is used to reject disturbance uncertainty (e.g. wind) by estimating disturbance torque value of quadcopter. simulation result shows that pdafc is better than pd and afc can minimize disturbance uncertainly effect. the sensitivity toward disturbance uncertainly can be set from sensitivity constant to get best performance of disturbance rejection. constant disturbance simulation result shows that the best sensitivity constant ( ) is 0.15, the quadcopter maximum error is 0.125 radian and can stable in 5 seconds. fluctuated disturbance simulation result shows that pdafc with 0.18 sensitivity constant gives lowest rms error value, there are 0.074 radian for sine disturbance, 0.055 radian for sawtooth disturbance, and 0.092 radian for square pulse disturbance. keywords: “x” configuration quadcopter, pd, afc. i. introduction unmanned aerial vehicles (uavs) have been developed and used over the last few years. uavs can be built not only for a hobby but also for performing important task such as area mapping, surveillance, disaster monitoring, air pollution monitoring, etc. they are capable to hover without an on-board pilot. uavs become good choice because it has low operational cost and also is safe in important task where risk to pilot are high. quadcopter has a simple structure. it utilises rotors which are directed upwards and placed at the end of a crossed frame. it is controlled by adjusting the angular velocities of each rotors. the quadcopter biggest advantage is that the blades do not have to be movable. a normal helicopter has blades that can be tilted up or down to vary lift. they have complex joints at the hub of the blade, which makes the blades hard to manufacture, difficult to maintain, and very dangerous if any failure occurs. moreover, quadcopter can take off, land in limited spaces and hover above targets. these vehicles have certain advantages over conventional fixed-wing aircraft for surveillance and inspection tasks. there are many researches about quadcopter control algorithm and uncertainty disturbance rejection. bouabdallah et al. designed an lq controller and pid controller then compared it [1]. the pid controller result is better than lq controller. jun li and yuntang li designed pid controller to control angular and linear position, and succeeded to stabilize quadcopter [2]. mokhtari and benallegue applied state parameter control to quadcopter rotation angle [3]. by using state observer, quadcopter can measure external disturbance. gupte et al. described that “x” configuration quadcopter is more stable than “+” configuration quadcopter because of the distribution of rotor force during hover [4]. bora and erdinc have been controlling position of quadcopter using pd controller and combined by using a vision system [5]. pounds et al. developed independent linear siso controllers to regulate quadcopter using pid controller [6]. a. tayebi et al. proposed a controller which is based upon the compensation of the coriolis and gyroscopic torques and the use of pd 2 feedback structure [7]. sumantri et al. designed a sliding * corresponding author. tel: +6285733316323 e-mail: niam@eepis-its.edu http://dx.doi.org/10.14203/j.mev.2014.v5.67-74 n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 68 mode control using a nonlinear sliding surface (nss) to design a robust tracking controller for a quad-rotor helicopter [8]. chen and huzmezan used linear h∞ controller to achieve stabilization in angular rates, vertical velocity, longitudinal velocity, lateral velocity, yaw angle, and height of a quadcopter [9]. a linear h∞ controller can be designed to obtain stabilization and tracking performance using a systematical approach [10]. pitowarno had designed active force control and knowledge-based system for planar twojoint robot arm to improve performance of active force control [11]. katsura et al. have been modeled force sensing using disturbance observer without force sensor [12]. chen et al. designed disturbance observer control for nonlinear system to control robotic manipulator [13]. it is very important to make a simple control algorithm to control the quadcopter stability although get uncertainty disturbance from environment. because in real system, control algorithm will be embed in low speed data processing unit. pd can stabilize quadcopter but still not enough to maintain the quadcopter against uncertainty disturbance such as wind. afc has the ability to estimate the force on the system without using complicated mathematical computation. the purpose of this work is modelling and combining pd and afc to control “x” configuration quadcopter when hover even if get uncertainty disturbance. this paper is structured as follows. section 2, presents a quadcopter dynamic modelling. section 3, deals quadcopter controller design. section 4, presents the performance of the controller is shown in numerical simulations. finally, in section 5 conclusions of this work. ii. quadcopter modelling before designing the controller, in this section the mathematical model of the quadcopter will be presented. this dynamic model as much as possible same as the real quadcopter. it is contain the model of the rotor force and torque, gyroscopic effect, and the derived force model of “x” configuration quadcopter. figure 1 is the design of “x” configuration quadcopter. the rotors (m1, m2, m3, m4) are placed in sequence π/4, 3π/4, 5π/4, 7π/4. two diagonal rotors (m1 and m3) are rotating in the same direction (counter clockwise) whereas the others (m2 and m4) in the clockwise direction to eliminate the anti-torque that caused by rotor rotation. absolute position of the quadcopter can be described by a coordinate position of the body frame {b} with reference earth frame {e}. absolute attitude of the quadcopter can be described by three euler’s angles ( ),which are roll, pitch, and yaw with reference to body frame {b} when xb, yb, and zb axis are in parallel with x, y, and is rotated 180° z axis. to make a movement along xb axis, quadcopter must produce pitch torque ( ). it means, quadcopter decreases rotor speed at m1 and m4, and increases rotor speed at m2 and m3. likewise to make movement along yb axis quadcopter must produce roll torque ( ). quadcopter decreases rotor speed at m1 and m2, and increases rotor speed at m3 and m4. then, to change quadcopter heading, quadcopter must produce yaw torque ( ) by increasing m1 and m3 rotor speed, and decreasing m2 and m4 rotor speed. figure 2 shows the force distribution in quadcopter. “f1, f2, f3, f4” arrows are thrust figure 1. an “x” configuration quadcopter n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 69 force of each motor, and “m.g” arrow is weight force of quadrotor. from li et al., the thrust and hub force for each rotor ( ) can be represented in equation (1) and (2) [2]. thrust force is the resultant of the vertical forces acting on all blade elements. hub force is the resultant of the horizontal forces acting on all blade elements. (1) (2) where is air density; is thrust constant that depends on polar lift slope, geometric blade, velocity through motor, the ratio of the surface area and rotor disk area [6]. is drag constant, and is propeller rotation speed. quadcopter can change its position by combining translation and rotation angle. linear movement on the quadcopter can be produced by total thrust force of the four rotors in equation (3), whereas changes in the angle of rotation (roll, pitch, yaw) will cause a change in the direction of quadcopter translational movement. so, the total forces of the quadcopter can be decomposed into force elements in each axis ( ). figure 3 shows the illustration of force decomposition to each axis in body frame {b}. ∑ (3) equation (4) is rotation matrix of quadcopter. are cosine and sine function respectively. [ ] (4) the derived model of quadcopter translational movement can be represented as equation (5). where ̈ ̈ ̈ are linear acceleration in of quadcopter in each axis. [ ̈ ̈ ̈ ] [ ] [ ] (5) the model also contains a gyroscopic effect. derived torque models of quadcopter are presented in equation (6), (7), and (8). [ ] [ ] ̇ ̇ (6) [ ] [ ] ̇ ̇ (7) ̇ ̇ (8) are roll, pitch, and yaw torque respectively. is distance of rotor between center of mass. ̇ ̇ ̇ are roll, pitch, and yaw angular body speed respectively. are roll, pitch, and yaw body inertia respectively. is force resistance constant in equation (2). let us define the control inputs of quadcopter are . where is total force to control input. total force control input can be figure 3. total forces illustration that decomposed into each axis figure 2. force distribution in quadcopter n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 70 derived by substituting equation (1) to (3). is roll torque control input, is pitch torque control input, and is yaw torque control input can be derived by substituting equation (1) to (6)(7) and equation (2) to (8). where, and are constant values from equation (1) and (2). ∑ ∑ (9) ∑ ∑ by substituting equation (9) into (5) to (8), the derived model of quadcopter in (10). ̈ ̈ ̈ ̈ ̇ ̇ (10) ̈ ̇ ̇ ̈ ̇ ̇ where ̈ ̈ ̈ are roll, pitch, yaw, angular acceleration at quadcopter body. iii. quadcopter controller design in this section, the control algorithm of quadcopter is presented. the purpose is to combine pd and afc as rotational controller to stabilize quadcopter. figure 4 shows quadcopter control structure. figure 5 shows the proposed rotational controller to stabilize quadcopter. in this simulation, translational movement are neglected. the controller design is focused to stabilize the quadcopter toward disturbance. pd controller is used to stabilize quadcopter and afc to reject uncertainty disturbance from environment. in this simulation, quadcopter get constant and fluctuated disturbance. from figure 4, the relationship of each input and each state can be represented as: ̇ [ ̇ ̇ ̇] (11) [ ] ̇ [ ̇ ̇ ̇ ̈ ̈ ̈] the system matrix (a) can be represented as: a = [ ̇ ̇ ̇ ̇ ̇ ̇ ] (12) the control matrix (b) can be represented as: b = [ ] (13) figure 4. quadcopter control structure n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 71 a. disturbance model in this subsection, the model of disturbance will be presented. figure 1 shows disturbance position of quadcopter, disturbance mass located at (ldxb, ldyb) from the center of quadcopter in (xb, yb) axis. state equation (11) can be written as follows: ̇ (14) the simulation disturbance is: [ ] (15) b. pd controller design pd controller will be presented to stabilize quadcopter. the reason is this controller very simple and easy implemented. in this section, pd control algorithm is designed without disturbance parameter. the controller design is focused to stabilize quadcopter when hovering without get uncertainty disturbance. the model that presented at section 2 is completed by gyroscopic effect. gyroscopic effect can be ignored because it does not have significant effect on quadcopter system [14]. the model can be simplified: ̈ ∑ ̈ ∑ (16) ̈ ∑ the simulation purposes to stabilize roll, pitch, and yaw angle. integrating twice about time and introducing s operator in equation (16), the model can be rewritten as: ∑ ∑ (17) ∑ from equation (17), the model is second order form, in order to make it possible to design multiple pd controllers for this system, one can neglect gyroscopic effects and thus remove the cross coupling [1]. this is pd controller for each orientation angle. (18) where are control input for roll, pitch, yaw torque respectively; are proportional control for roll, pitch, and yaw respectively; are derivative control for roll, pitch, and yaw respectively. c. afc controller design afc controller is designed to reject uncertainty disturbance from environment. figure 6 shows afc block diagram that used in simulation. this block has two inputs, they are measured angular velocity and applied propeller speed. let us define as rotation angle roll and pitch axis ( ), ̈ ̇ (19) = (20) ̈ (21) figure 5. the proposed rotational controller n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 72 ̈ ̈ ̈ (22) ( ̈ ) , with ̈ ( ̈ ̈) (23) first input is measured angular velocity that differentiated into actual angular acceleration in equation (19). second input is applied propeller speed that converted into angular acceleration reference in equation (21). ̈ is estimated disturbance acceleration. to get estimated disturbance, actual angular acceleration is compared by angular acceleration reference in equation (22) [11]. last, convert the disturbance acceleration into propeller speed in equation (23) then add the result with pd controller result. is a constant value to set afc sensitivity output toward disturbance, then simplified to . is propeller speed calculation of afc controller output. iv. simulation result the simulation test was performed using simulink to evaluate the performance of the controller. the simulation model (10) was used in s-function block. in this simulation, the model contain disturbance that has been modeled in section 3, there are constant and fluctuated disturbances. before doing some simulation process, the parameters of quadcopter must be collected from real data. this simulation used quadcopter data obtained from [16]. they are listed in table 1. pd coefficients that used for simulations were derived by trial and error to get best performance, the pd parameter are listed in table 2. first simulation compared pd and pdafc performance when they constant disturbance. second, third, and fourth simulation compared pd and pdafc performance when they fluctuate disturbance using sinusoid disturbance, sawtooth disturbance, and pulse disturbance. then, root mean square (rms) method was used to determine the controller performance analysis. lower rms error value means better performance of controller. figure 7 shows the simulation result of pd method and pdafc method with constant disturbance. in this simulation, pdafc was tested with three figure 6. afc block diagram table 1. quadcopter simulation parameter parameter unit value m kg 1.025 l meter 0.270 kt ns 2 3.122e-06 kd nms 2 1.759e-08 ixx,iyy kgm 2 0.012 izz kgm 2 0.048 disx n amp x waveform(freq) 1. 0.2 2. 0.2 x s (2π0.4t) 3. 0.2 x sawtooth (0.4 hz) 4. 0.2 x square (0.4 hz) ldxb mm 0 ldyb mm 190 table 2. pd coefficients simulation parameter parameter value kp roll 0.097 kd roll 0.036 kp pitch 0.097 kd pitch 0.036 kp yaw 0.0001368 kd yaw 0.0000684 n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 73 sensitivities constants ( ) in equation (23), they were 0.13, 0.15 and 0.18. by using pd, maximum error is 0.326 radian with rms valued is 0.060. pdafc with 0.13 constant, maximum error is 0.153 radian and rms value is 0.029. then with 0.15 constant, maximum error is 0.125 radian and rms value is 0.017, it can stable in 5 seconds. last is pdafc with 0.18 constant, maximum error is 0.090 radian and rms value is 0.018, but still noisy because of the controller became more sensitive with disturbance. figure 8 shows second simulation result to compare pd method and pdafc method with sine function disturbance. in this simulation, disturbance maximum amplitude was 0.2 with frequency 0.4 hz. pdafc was tested with three sensitivities constant ( ) in equation (23), which were 0.13, 0.15 and 0.18. pd maximum error is 0.394 radian with rms value of 0.255. pdafc with 0.13 constant, maximum error was 0.210 radian and rms value is 0.121. then with 0.15 constant, maximum error is 0.161 radian and rms value is 0.098. last is pdafc with 0.18 constant, maximum error is 0.130 radian and rms value is 0.074. pdafc with 0.18 constant give lowest rms error value. figure 9 shows third simulation by using sawtooth function disturbance. in this simulation, disturbance maximum amplitude is 0.2 with frequency 0.4 hz. pdafc was tested with three sensitivities constant ( ), they were 0.13, 0.15 and 0.18. pd maximum error is 0.241 radian with rms valued is 0.186. pdafc with 0.13 constant, maximum error is 0.241 radian and rms value is 0.092. then with 0.15 constant, maximum error is 0.199 radian and rms value is 0.073. last is pdafc with 0.18 constant, maximum error is 0.156 radian and rms value is 0.055. pdafc with 0.18 constant give lowest rms error value. figure 10 shows fourth simulation by using square function disturbance. in this simulation, disturbance maximum amplitude was 0.2 with frequency 0.4 hz. pdafc was tested with three sensitivities constant ( ), they were 0.13, 0.15 and 0.18. pd maximum error is 0.575 radian, rms value is 0.317. pdafc with 0.13 constant, maximum error is 0.315 radian and figure 7. constant disturbance simulation result figure 8. sine disturbance simulation result figure 9. sawtooth disturbance simulation result figure 10. square disturbance pulse simulation result n. tamami et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 67-74 74 rms value is 0.170. then with 0.15 constant, maximum error is 0.272 radian and rms value is 0.128. last is pdafc with 0.18 constant, maximum error is 0.190 radian and rms value is 0.092. pdafc with 0.18 constant give lowest rms error value. v. conclusion an “x” configuration quadcopter has been successfully modeled. then, simulation results have been presented to show the controller performance. by adding pd with afc, better result was obtained. from the simulation, pdafc controller can minimize the effect of disturbance. inconstant disturbance simulation, the best sensitivity constant ( ) was obtained when the value was 0.15, the quadcopter maximum error 0.125 radian and could stable in 5 seconds. in fluctuated simulation result, pdafc with 0.18 constant gave lowest rms error value, 0.074 radian for sine disturbance, 0.055 radian for sawtooth disturbance, and 0.092 radian for square pulse disturbance. acknowledgement the author would like to thank the electronic engineering polytechnic institute of surabaya for giving laboratories facilities for the research. references [1] bouabdallah et al. "pid vs lq control techniques applied to an indoor micro quadrotor." intelligent robots and systems, 2004.(iros 2004). proceedings. 2004 ieee/rsj international conference on. vol. 3. ieee, 2004, pp.2451-2456. [2] li, jun, and yuntang li. "dynamic analysis and pid control for a quadrotor."mechatronics and automation (icma), 2011 international conference on. ieee, 2011, pp. 573-578. [3] mokhtari et al. "dynamic feedback controller of euler angles and wind parameters estimation for a quadrotor unmanned aerial vehicle." robotics and automation, 2004. proceedings. icra'04. 2004 ieee international conference on. vol. 3. ieee, 2004, pp. 2359-2366. [4] gupte et al. "a survey of quadrotor unmanned aerial vehicles." southeastcon, 2012 proceedings of ieee. ieee, 2012, pp. 1-6. [5] erginer et al."modeling and pd control of a quadrotor vtol vehicle." intelligent vehicles symposium, 2007 ieee. ieee, 2007, pp. 894-899. [6] pounds et al."modelling and control of a large quadrotor robot." control engineering practice 18.7 elsevier, pp. 691-699, 2010. [7] tayebi, a., and s. mcgilvray. "attitude stabilization of a four-rotor aerial robot." decision and control, 2004. cdc. 43rd ieee conference on. vol. 2. ieee, 2004, pp. 1216-1221. [8] sumantri et al. "robust tracking control of a quad-rotor helicopter utilizing sliding mode control with a nonlinear sliding surface." journal of system design and dynamics 7, no. 2, pp. 226-241, 2013. [9] ming chen and mihaihuzmezan, “a combined mbpc/2dof h∞ controller for a quadrotor uav”, proceeding of aiaa guidance, navigation, and control conference and exhibit, texasusa, 11-14 august 2003. [10] estiko rijanto, “robust control: theory for application”, isbn: 979-9299-12-8, bandung: itb press, 2000. [11] pitowarno, endra. "an implementation of a knowledge-based system method to an active force control robotic scheme." master thesis, universiti teknologi malaysia, 2002. [12] katsura, seiichiro et al. "modeling of force sensing and validation of disturbance observer for force control." industrial electronics, ieee transactions on 54, no. 1, pp. 530-538, 2007. [13] chen, wen-hua. "disturbance observer based control for nonlinear systems." mechatronics, ieee/asme transactions on 9, no. 4, pp. 706-710, 2004. [14] bouabdallah et al."design and control of an indoor micro quadrotor." robotics and automation, 2004. proceedings. icra'04. 2004 ieee international conference on. vol. 5. ieee, 2004, pp. 4393-4398. [15] benallegue, a. et al. "feedback linearization and high order sliding mode observer for a quadrotor uav." variable structure systems, 2006. vss'06. international workshop on. ieee, 2006, pp. 365-372. [16] ni’am tamami et al."modelling and pd control for “x” configuration quadcopter." indonesian symposium on robot soccer competition, 2013. proceedings. dian nuswantoro university. isbn:979-26-0264x, semarang: dian nuswantoro university press, 2013, pp. 98-103. mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.127-134 mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car seno aji a, *, dwi ajiatmo b , imam robandi a , heri suryoatmojo a a department of electrical engineering, institut teknologi sepuluh nopember (its) kampus its sukolilo, surabaya, east java, indonesia. telp. (+6231) 5947302 b department of electrical engineering, universitas darul ulum jombang jl. presiden kh. abdurrahman wachid 29 a, jombang, east java, indonesia.telp. (+62321) 854106 received 18 october 2013; received in revised form 04 november 2013; accepted 06 november 2013 published online 24 december 2013 abstract this paper presents a control called maximum power point tracking (mppt) for photovoltaic (pv) system in a solar car. the main purpose of this system is to extracts pv power maximally while keeping small losses using a simple design of converter. working principle of mppt based fuzzy logic controller (mppt-flc) is to get desirable values of reference current and voltage. mppt-flc compares them with the values of the pv's actual current and voltage to control duty cycle value. then the duty cycle value is used to adjust the angle of ignition switch (mosfet gate) on the boost converter. the proposed method was shown through simulation performed using psim and matlab software. simulation results show that the system is able to improve the pv power extraction efficiency significantly by approximately 98% of pv’s power. keywords: maximum power point tracking (mppt), photovoltaic (pv), boost converter, fuzzy logic controller, solar car. i. introduction consumption on fossil fuels as source of transportation energy has been predicted to increase along with population and economic growth in indonesia. on the other hand, the depletion of fossil fuels, increasing emissions of pollutants and greenhouse gases become a serious problem in big cities. nowadays, renewable energy becomes a solution to solve this problem in supplying the energy needs especially in the field of transportation. there are so many kinds of renewable energy that have been developed as sources of energy for transportation. indonesia is a tropical region and has availability of abundant solar energy. among renewable energy sources, solar energy seems to be the most attractive energy source for electrical energy used by cars in indonesia. the advantages of solar energy compared to fossil fuels are because it is clean, pollution-free, and quiet/without sound. conversion of solar energy into electrical energy requires a device called a photovoltaic (pv). lately, pv has been produced in different types. some commercial pvs have average efficiency varying with the highest efficiency value of 20 % [1]. electricity provided by pv is the result of voltage and current in the same time. pv voltage and current depends on temperature and solar irradiation changes. maximum power point tracking (mppt) is a technique to extract possible maximum power from the pv modules under all conditions of temperature and solar irradiation. mppt has to use a good algorithm to find the mpp condition in a short time and also has a high efficiency. mppt simulations have been investigated over the last few years and are summarized in [2-4]. many conventional methods have been used for mppt such as perturb and observe (p&o), fractional open-circuit voltage and incremental conductance. conventional methods have slow responds and unsatisfactory. to resolved this problem and overcome non linearity of pv, an intelligent mppt algorithm based on fuzzy logic controller (flc) will be discussed in this paper. *corresponding author. tel.: +62-85695045489 e-mail: senoaji.eepis@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.127-134 s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 128 ii. material and method a. electrical car powered by pv electric car (ec) powered by photovoltaic (pv) project is a joint research between the institut teknologi sepuluh nopember (its) surabaya and smk muhammadiyah 7 gondanglegi, malang. this ec’s name is suryawangsa. it uses brushless dc motor as its main propulsion and lead-acid batteries as its source of electricity. there are four pvs on the top the ec. total maximum output power of the pv is 200 watts. battery in addition is being used as a source of electrical energy storage or as energy storage generated by photovoltaic (pv). the electric car powered by pv is able to perform self-charging from sun energy. this car’s design and shape can be seen in figure 1 [5]. in figure 1, the whole car system consists of 6 blocks of diagram. the first block is photovoltaic array. the second block is boost converter. the third block is battery. the fourth block is dc motor’s driver. the fifth block is speed/torque control system of dc motor and the last block is monitoring system using serial communication. this paper focus is on the battery charging powered by pv as shown by block 1-3. photovoltaic model pv model is described as a simple circuit consisting of a current source which is connected in parallel with a diode as shown in figure 2. pv’s output power depends on irradiation of sunlight and temperature received by pv cell’s surface [6]. pv has various types and models. each pv module has different characteristics and efficiency. in this work, the selected pv module is bell 50wp whose specification is shown in table 1. this pv module was simulated using psim software in order to get the i-v (current-voltage) and p-v (power-voltage) curves. simulation results are plotted in figure 3 and figure 4. figure 3 is the simulation results with different temperature and constant irradiation conditions, 1 pv array mppt fuzzy current voltage duty cycle 3. battery 48 volt 4 motor drive dc motor 3500watt 5 contol system of speed, torque speed reff 2 boost converter 6 monitoring with pc serial communication input voltage input current boost’s power output voltage output current battery’s power pv’s power motor’s power figure 1. electrical vehicle powered by pv [5] iph d rp rs icell + vcell figure 2. pv model s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 129 while figure 4 is the simulation results with different irradiation and constant temperature conditions. b. boost converter design dc-dc boost converter has an important role in the pv system. mpp conditions can be achieved by using boost converter as a power conditioner. references [7-8] offers boost converter topologies. in this paper the boost converter topology shown in figure 5 is used [9]. it consists of a single mosfet or igbt switch, an inductor, a diode and a capacitor. to design a good converter, it requires calculation of appropriate components since wrong values of the components may cause unfavorable outcomes. the results of equation (1 to 5) are parameters that required for the design of boost converter [5], as seen at table 2. where: p is power, vin is input voltage, iin is input current, vout is output voltage, iout is output current, f is frequency, d is duty cycle, r is resistance, il is inductor’s current, l is inductor and c is capacitor. calculation of duty cycle (d): 𝐷 = 1 − (𝑉𝑖𝑛/𝑉𝑜𝑢𝑡) = 1 − (34/50) = 32 (1) calculation of output current (iout): 𝐼𝑜𝑢𝑡 = 𝑃/𝑉𝑜𝑢𝑡 = 200𝑊/50𝑉 = 4𝐴 (2) calculation of resistance (r): 𝑅 = 𝑉𝑜𝑢𝑡/𝐼𝑜𝑢𝑡 = 50𝑉/4𝐴 = 2.5𝛺 (3) calculation of inductor’s current (il): table 1. specifications of solar panel spesifications value manufacture bell electronics standart irradiance and temperature 1000 w/m2, 25°c maximum power (pmax) 50 w voltage @ pmax (vmp) 17.35 v current @ pmax (imp) 2.88 a open-circuit voltage (voc) 21.88 v short-circuit current (isc) 3.08 a number of cell 24 cell tollerance wattage 5% weight module 10 kg size module 670cm*620cm*35 cm (a) (b) figure 3. simulation result of different irradiance from 100 w/m 2 until 1000 w/m 2 (step 100 w/m 2 ) and constant temperature at 25°c; (a) p-v curve; (b) i-v e s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 130 𝐼𝐿 = 0.2 × 𝐼𝑖𝑛 = 0.2 × 𝐼𝑜𝑢𝑡 × 𝑉𝑜𝑢𝑡/𝑉𝑖𝑛 (4) = 0.2 × 4𝐴 × 50𝑉 34𝑉 = 0.11𝐴 calculation of inductor (l): 𝐿 = (𝑉𝑖𝑛 × (𝑉𝑜𝑢𝑡 – 𝑉𝑖𝑛))/(𝐼𝐿 × 𝑓 × 𝑉𝑜𝑢𝑡) (5) = 34𝑉 × 50𝑉 − 34𝑉 0.11𝐴 × 20khz × 50v = 5.44 𝑚𝑖𝑙𝑖𝐻𝑒𝑛𝑟𝑦 calculation of capacitor (𝐶): assumed: ∆vout/vr = 0.1v 𝐶 = (𝑉𝑜𝑢𝑡 × 𝐷)/((∆𝑉𝑜𝑢𝑡/𝑉𝑟) × 𝑓 × 𝑅) (6) = 50𝑉 × 0.32 0.1 × 20𝑘ℎ𝑧 × 12.5𝛺 = 640 𝑢𝐹 c. maximum power point tracking (mppt) the basic method of mppt controller is to find voltage reference (vmpp) and current reference (impp) under different conditions of solar irradiation and temperature by changing the value of load (r). figure 6 shows characteristics of i-v (current-voltage) and p-v (power-voltage) curves. working point (opr1) is the maximum power point (mpp) value in the condition insolation (λ1), temperature (t1) and load (r1). if irradiation changes from λ1 to λ2 and temperature change from t1 to t2, the i-v curve shift from the curve (λ1, t1) to the curve (λ2, t2). load condition should be changed from r1 to r2 to get mpp conditions (opr2). d. fuzzy logic controller (flc) a fuzzy logic controller (flc) uses two inputs such as error (e) and changes in error (∆e), while the output of flc is the duty cycle (a) (b) figure 4. simulation result of different temperature from 10°c until 50°c (step 5°c) and constant irradiance 1000 w/m 2; (a) p-v curve; (b) i-v curve s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 131 d. equation 7 is error’s equation and equation 8 is change in error’s equation. 𝐸 𝑘 = 𝑃 𝑘 −𝑃 𝑘−1 𝑉 𝑘 −𝑉 𝑘−1 (7) ∆𝐸 𝑘 = 𝐸(𝑘) − 𝐸(𝑘−1) (8) designing a flc involves four steps: fuzzification, interference, rule based, and defuzzification. numerical input variables are converted into linguistic variables based on the membership function during fuzzification [10]. in operation of mppt control, after e and ∆e are calculated, these inputs are converted into linguistic variables and then the output d is generated by looking up a rule-base table. the flc tracks the mpp based on master rule of “if a and b, then c” [10]. to determine the output of the fuzzy logic, the inference is used. there are many methods for inference but the popular one is mamdani [10]. in this paper, fuzzy vi vo + + -l c figure 5. boost converter. figure 6. mppt curve (a) (b) (c) figure 7. (a) membership e(k), (b) membership ∆e (k), (c) membership duty cycle table 2. specification of boost converter parameter value power (p) 200 watt input voltage (vin) 34 volt output voltage (vout) 50 volt frequency 20 khz capacitor (c) 640 uf inductor (l) 5.44 mh load resistor (r) 12.5 ohm table 3. fuzzy rule e ∆e nbe nse ze pse pbe nbde m m vb vb vb nsde m m b b b zede b m m m s psde s s s m m pbde vs vs vs m m s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 132 inference is carried using mamdani’s type and the defuzzification use the center of grafity (cog) to compute the output of this flc [11]. the result of this process is membership function of mppt control, as seen at figure 7 and fuzzy rule, as seen in table 3. where: nbe is negative big error, nse is negative small error, ze is zero error, pbe is positive big error, pse is positive small error, nbde is negative big delta error, nsde is negative small delta error, zde is zero delta error, pbde is positive big delta error, psde is positive small delta error, vs is very small, s is small, m is medium, b is big and vb is very big. iii. simulation designing a pv model and a boost converter on psim is simpler than on matlab. the problem is that a fuzzy logic controller cannot be designed on psim. sim coupler in figure 8 is a plug-in that could help to connect matlab simulink with psim. block diagram of pv system is shown in figure 9. it consists of pv array (yellow), boost converter (purple), mppt based fuzzy logic controller/flc algorithm (red) and the battery/load (blue). the mppt algorithm (red) is explained in more detail in figure 10 and figure 11. simulation results in figure 3 and figure 4 show that the effect of irradiation changes is more significant than the effect of temperature changes in pv’s output power changes. therefore, simulation was only done by changing the value of irradiation and keeping temperature constant. figure 12 shows simulation result of the pv system with mppt. figure 13 shows simulation result of the pv system without mppt. the system was tested in irradiation 1000 w/m 2 , 800 w/m 2 , and 600 w/m 2 . it shows that pv’s power output almost reached the maximum power (pmax). from the results in table 4 and table 5, it is obvious that the system with mppt gives higher efficiency than that without mppt. it is concluded that the mppt system could produce a maximum power output of pv eventhough under different (high/low) irradiation conditions. figure 8. psim coupler in matlab simulink figure 10. schematic of mppt system in psim pv array dc-dc converter ( boost) mppt fuzzy control system temperatur e iradiation pwm (duty cycle) load baterai vref vdc vdc vpv ipv figure 9. block diagram of pv system s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 133 figure 11. schematic of mppt in matlab figure 12. simulation result with mppt system figure 13. simulation result without mppt system s. aji et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 127-134 134 iv. conclusion in this paper we have presented the design and simulation of maximum power point tracking (mppt) for a photovoltaic system in the solar car using fuzzy logic. based on simulation results we can conclude that: the effect of irradiation changes is more significant than the effect of temperature changes in pv’s output power changes. the resulting efficiency value system with mppt is 96 to 98% (almost reaches the maximum peak power), while the efficiency of the resulting system without mppt is 51% to 90% (not producing maximum power). acknowledgement authors would like to thank to vocational high school muhammadiyah 7, gondanglegi malang, indonesia, and lpdp (lembaga pengelola dana pendidikan) for their supports in financial and facilities. references [1] t. esram and p.l. chapman, “comparison of photovoltaic array maximum power point tracking techniques,” ieee transactions on energy conversion vol. 22, pp. 439-449, june 2007. [2] e. bianconi, et al., “perturb and observation mppt algorithm with a current controller based on the sliding mode,” science direct: electrical power and energy systems vol.44, pp. 346-356, july 2012. [3] t. esram and p.l. chapman, “t-s fuzzy maximum power point tracking control of solar power generation systems,” ieee transactions on energy conversion vol. 25, no. 4, december 2010. [4] c. b. salah and m. ouali, “comparison of fuzzy logic and neural network in maximum power point tracker for pv systems,” science direct: electric power systems research vol. 81, pp. 43–50, july 2010. [5] m. veerachary, et al., “neural network based maximum power point tracking of coupled inductor interleaved boost converter supplied pv system using fuzzy controller,” ieee trans. ind. electron., vol. 50, no. 4, pp. 749–758, august 2003. [6] hong wang, “the stand-alone pv generation system with parallel battery charger”, international conference on electrical and control engineering (icece), pp. 4450-4453, june. 2010. [7] m. a. a. mohd zainuri, et al., “adaptive p&o fuzzy control mppt for pv boost dcdc converter,” ieee international conference on power and energy (pecon), 978-1-4673-5019-8, december 2012. [8] l. guo, et al., “design of a fuzzy controller using variable structure approach for application to dc–dc converters,” science direct: electric power system research vol. 83, pp.104-109, august 2012 [9] j.m. enrique, et al., “a reliable, fast and low cost maximum power point tracker for photovoltaic applications,” solar energy vol. 84, pp. 79-89, november 2009. [10] yeu wu, et al, “fuzzy logic and neuro-fuzzy system: a systemetic introduction”, international journal of artificial intelligence and expert system (ijae) vol. 2, issue 2, pp 47-80, 2011. [11] a. m. a. mahmoud, et al., “fuzzy logic implementation for photovoltaic maximum power tracking,” in proc. 9th ieee int. workshop robot human interactive commun., pp. 155–160, 2000. table 4. power output with mppt at irradiation 800-1000 w/m 2 and temperature 25°c parameters pmax power out efficiency 1000 w/m 2 200 196 98% 800 w/m 2 163 160 98% 600 w/m 2 104 100 96% table 5. power output without mppt at irradiation 800-1000 w/m 2 and temperature at 25°c parameters pmax power out efficiency 1000 w/m 2 200 190 95% 800 w/m 2 163 139 85% 600 w/m 2 104 54 51% mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.115-122 comparison of unmodulated current control characteristics of permanent magnet synchronous motor anwar muqorobin a,*, pudji irasari a, taufik b a research centre for electrical power and mechatronics, indonesian institute of sciences jl. sangkuriang komplek lipi gedung 20 lantai 2 bandung, 40135, indonesia b electric power institute, california polytechnic state university san luis obispo, ca 93407, united states of america received 10 september 2014; received in revised form 29 october 2014; accepted 29 october 2014 published online 24 december 2014 abstract this paper discusses comparison of unmodulated current controls in permanent magnet synchronous motor (pmsm), more specifically, on-off, sliding mode, predictive and hybrid controls. the purpose of this study is to select the most appropriate control technique to be adopted. the comparison method is preceded by modeling the motor and entering the values of the motor parameters. pi control is used for speed control and zero d-axis current is employed. furthermore, performing simulation for each type of the selected current controls and analyzing their responses in terms of dq and abc currents, q-axis current response with step reference, as well as total harmonic distortion (thd). simulation results show that the on-off control gives the best overall performance based on its abc-axis current ripple and thd at large load torque. the hybrid control shows the best response occurring only at the fastest transient time of q-axis current but its response exhibits bad qualities compared with other controls. the predictive control yields the best responses offering the smallest d-axis ripple current and thd at small load torque condition. the sliding mode control, however, does not exhibit any prominent performance compared to the others. results presented in this paper further indicate that for the pmsm used in the simulation the most appropriate control is the predict ive control. keywords: unmodulated current controls, on-off control, sliding mode control, predictive control and hybrid control. i. introduction permanent magnet synchronous motor (pmsm) has gradually shifted the use of induction motor for small to medium power applications. compared to induction motor, pmsm has higher torque to current ratio, higher power to volume ratio as well as higher efficiency and power factor. in addition, without the existence of slip this type of motor is easier to control. vector control that has been employed successfully for induction motor can simply be applied for pmsm. in motor control, the most influencing parameter is torque that is proportional to the motor speed. therefore, in a closed loop speed control, the control will provide torque reference associated with the desired speed. meanwhile, load torque that has opposite correlation with system torque is considered as disturbance. to obtain a certain value of torque according to the reference given by the speed control, a torque control inside the closed loop speed control is engaged. an example is the direct torque control (dtc) which was initially applied for induction motor [1] and then was successfully introduced to pmsm [2, 3]. since theoretically motor torque is proportional to current; hence, controlling current in vector control method is basically to control the motor torque. some current controllers that have been implemented for pmsm are conventional nonlinear control (on-off, hysteresis, delta modulation) [4-6], pi control [79], internal model control [10, 11], linear matrix inequality [12], resonant control [13], sliding mode control [14-16], predictive control [17-22], hybrid control [23], and intelligence control [24, 25]. furthermore, these controls can be categorized basically in two types: with modulation [7-15, 17-20, 22, 24, 25] and without modulation [4-6, 16, 19, 21, 23]. the modulated * corresponding author. phone: +62-22-2504770 e-mail: anwa006@lipi.go.id http://dx.doi.org/10.14203/j.mev.2014.v5.115-122 a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 116 control requires a process to calculate the duty cycle of pulse width modulation. on the other hand, the unmodulated control does not need such process since the control provides on and off actions directly into the switching components of inverter. additionally, the modulated control has a better steady state response since its switching frequency is not varied. according to [23, 25, 26], pi control with pwm gives better steady state response while the modern control has better response during transient condition. however, [21] demonstrates that pi control with pwm could provide better response in steady state and transient conditions. this paper compares four unmodulated current control techniques for a pmsm including on-off control, sliding mode control, predictive control and hybrid control. prior to this comparison study, the pmsm was manufactured and measurement of its parameters had been carried out [27]. the objective of this paper is to select the most appropriate control technique to be adopted. ii. methodology comparison method of the characteristic of selected current controls is described using the flow chart in figure 1. a block diagram of speed control for pmsm is illustrated in figure 2. the speed control sets the reference of q-axis current. below nominal speed, there are some strategies for d-axis current reference, those are zero d-axis current, maximum torque per ampere (mtpa), maximum efficiency, unity power factor and constant mutual flux linkage (cmfl) [28]. in this study, pi control is used for speed control and zero d-axis current is employed due to its simplicity and our investigation is focused on current control. pmsm is modeled in dq-axis with the following equations: (1) ( ) (2) ( ( ) ) (3) (4) (5) where , represent dand q-axis stator voltage, and represent dand q-axis stator current, is stator resistance per phase, and represent dand q-axis inductance, is electromagnetic torque, is load torque, is motor and load moment of inertia, is the number of pole pair, is electrical angular velocity, is mechanical angular velocity, and is permanent magnet flux. the dand q-axis currents and voltages are obtained by using equation of abc to dq-axis transformation: [ ( ) ( ) ( ) ( ) ⁄ ⁄ ⁄ ] (6) while the inverse transformation from dq-axis to abc is [ ( ) ( ) ( ) ( ) ] (7) figure 2. block diagram of pmsm speed control [28] figure 1. flow chart for characteristic comparison of the current controls a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 117 the three phase inverter topology used to drive the pmsm and the voltage space vectors are shown in figures 3 and 4 respectively. there are eight control combinations for switching the inverter (table 1) [28]. the value of 1 means the upper switch is on and the lower one is off, while the value of 0 turns off the upper switch and on the lower one. a. on-off control the on-off control for current control in pmsm is shown in figure 5 [29]. this control has two actions of control (i.e. on and off) and it is referred to the unmodulated control where current references are set on abc axis [28]. therefore, the current references from the speed control should be first converted to abc axis. b. sliding mode control sliding mode control uses sliding surface to determine the control action. the sliding surface used is [14]: ( ) ( ) ∫ ( ) (8) equation (8) is a pi control algorithm. the block diagram of current control on abc axis by using sliding mode is illustrated in figure 6 [14]. the selection of abc coordinates on sliding mode control follows the same reason as that on the onoff control. c. hybrid control to design the hybrid control for a plant with dynamic model below ( ) ( ) (9) the following lyapunov function is applied: ( ) ( ) (10) with, ( ) ( ) ( ) (11) to maintain the system stability, the condition that should be fulfilled is ( ) ( ) (12) or in this case the following should hold: ( ) ( ) (13) eq.(1) and (2) can be rewritten as ( ) (14) ( ( ) ) (15) elaboration of eq.(13) yields, ( ) ( ) (16) the eight combinations of the control are then transformed into dq-axis and substituted in equation (14) and (15). the selected control is the figure 4. voltage space vector of three phase inverter table 1. switching combinations of three phase inverter vector combination of va, vb, and vc v0 000 v1 100 v2 110 v3 010 v4 011 v5 001 v6 101 v7 111 figure 6. sliding mode control [14] figure 3. three phase inverter topology for pmsm drive figure 5. on-off control [29] a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 118 one giving the smallest value in equation (16) [23]. the block diagram of the hybrid control is shown in figure 7 [28]. d. predictive control like hybrid control, predictive control also applies eight control combinations [29]. integration of equation (14) and (15) is solved to obtain id and iq currents to minimize the following function [19], ( ) ( ) ( ) (17) e. motor parameters the methods of measurement and calculation of the motor parameters have been presented in [27] and the results are listed in table 2. iii. results and discussion the four controllers are simulated with the same sampling time (1e -5 second) and mechanical angular velocity reference of 300 rad/s. the simulation is done first by loading the motor with the torque of 5 nm and then changed to 35 nm in 0.2 second. meanwhile, the speed control employs pi control with kp of 30 and ti of 3 seconds. the simulation results are depicted in figures 8 to 13. the blue line is the reference signal and the red line is the controlled output signal. figure 8 describes the mechanical speed of the motor implementing on-off control. within 0.2 seconds of the given torque, the motor can reach steady state in 0.05 seconds (figure 8a). despite the existence of offset error at steady state, the motor control tends to gain the reference point (figure 8b). figure 9 shows that in the steady state the motor torque follow the load torque closely. controlling current by using the other control methods yields similar speed response to that of the on-off control. the q-axis currents of the four controllers produce different transient responses as shown in figure 10. from all controls, the predictive control is the only one that does not show the offset error. meanwhile the ripple current (a) (b) figure 8. motor speed characteristics, (a) time to reach steady state, (b) tendency to gain the reference point figure 7. hybrid control [28] table 2. pmsm parameters parameters magnitude p 25 hp v 62.5 v p 3 pole pairs rs 11.15 mω m 0.0639 weber ld 0.123 mh lq 0.142 mh j 0.004177 kg.m 2 figure 9. motor torque a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 119 characteristics of the predictive and hybrid controls reveal uniform frequency, although their amplitudes are higher than that of the on-off and sliding mode controls. figure 11 illustrates the simulation of the transient response when the step reference is applied. the results are summarized in table 3 which shows that hybrid control yields the fastest transient time while the predictive control is the slowest. the replenishment of pi control in the on-off control (turns to sliding mode) does not improve the response of the system at steady state. both on-off and sliding mode controls generate an average of q-axis current lower than the reference or what so called the offset error. sliding mode control does not seem to reduce the figure 10. q-axis currents (a) on-off control (b) sliding mode control (c) predictive control (d) hybrid control figure 11. q-axis currents with step reference (a) on-off control (b) sliding mode control (c) predictive control (d) hybrid control a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 120 ripple produced by on-off control since both make use of the same final action that is without modulation. currents in the d-axis of the four controls are shown in figure 12. it appears that the on-off control and sliding mode control give large d-axis ripple currents, followed by the hybrid control and predictive control the smallest. the abc-axis currents of the four controls are exhibited in figure 13. paying attention to the peak of the sinusoidal wave, the ripple current produced by each controller in the order from the smallest to the largest are by the on-off control, sliding mode control, predictive control and hybrid control. figure 12. d-axis current (a) on-off control (b) sliding mode control (c) predictive control (d) hybrid control figure 13. q-axis currents (a) on-off control (b) sliding mode control (c) predictive control (d) hybrid control a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 121 tables 4 and 5 respectively represent thd of the motor when it is started with 35 nm and 5 nm of the load torque. from the two tables, it can be seen that the smallest harmonics is attained by two controllers at two opposite conditions, those are at low torque by the predictive control and at large torque by the on-off control. meanwhile the hybrid controls always generate high harmonics at both conditions. iv. conclusion comparative study of the four unmodulated current controls, namely on-off control, sliding mode control, predictive control and hybrid control, has been performed. computer simulations were conducted to investigate the responses from each controller on their dq-axis and abc currents, transient response, q-axis current response with step reference, as well as thd at small and large load torques. the simulation results show different characteristics of each controller that can be concluded as follows: good characteristic of the hybrid control is observed at the transient response of q-axis current (290 s) while other conditions yields bad quality of responses. the predictive control exhibits poor performance at the transient response of qaxis current (380 s). its best responses are represented by the smallest of both d-axis ripple current and thd at 5 nm of load torque. with other test conditions, its performance is good as indicated by its q-axis ripple current responses without offset error at steady state. the on-off control produces is superior in both abc-axis ripple currents and thd at 35 nm. however, its good performances are hindered by the existence of the offset error in q-axis current responses. the sliding mode control does not demonstrate a stand out performance compared to others. generally, its response qualities are in between the on-off and predictive controls. looking at overall performances, results of this study show that the most appropriate type of control for the given pmsm is the predictive control. acknowledgement the authors are grateful to kompetitif-lipi activity and to all team members of electric machines and power electronics research group for all assistance that has been given. references [1] i. takahashi and t. noguchi, "a new quickresponse and high-efficiency control strategy of an induction motor," ieee transactions on industry applications, vol. ia-22, pp. 820-827, sept/oct. 1986. [2] c. french and p. acarnley, "direct torque control of permanent magnet drives," ieee transactions on industry applications, vol. 32, pp. 1080-1088, sept/oct 1996. [3] l. zhong, et al., "analysis of direct torque control in permanent magnet synchronous motor drives," ieee transactions on power electronics, vol. 12, pp. 528-536, 1997. [4] p. pillay and r. krishnan, "modeling, simulation and analysis of permanentmagnet motor drives. part i: the permanentmagnet synchronous motor drive," ieee transactions on industry applications, vol. 25, pp. 265-273, march/april 1989. [5] a. naik, et al., "improved performance of adaptive hysteresis current controller based vector control of pmsm drive system," in proceedings of the ieee student’s technology symposium, 2011, pp. 1-8. [6] h. m. soliman and s. m. e. hakim, "improvement the current control methods for three phase voltage source inverter to drive the permanent magnet synchronous motor," international journal of engineering and advanced technology (ijeat), vol. 2, pp. 53-61, october 2012. [7] m. novak, et al., "application of sinusoidal phase current control for synchronous drive," in ieee international symposium on industrial electronics, 2006, pp. 2260-2265. table 4. thd at 35 n.m of the load torque control thd on-off 3.79 % sliding mode 3.83 % predictive 3.87 % hybrid 5.36 % table 5. thd at 5 n.m of the load torque control thd on-off 23.87 % sliding mode 23.35 % predictive 21.90 % hybrid 31.00 % a. muqorobin et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 115-122 122 [8] b. zigmund, et al., "experimental evaluation of pi tuning techniques for field oriented control of permanent magnet synchronous motors," advances in electrical and electronic engineering, pp. 114-119, 2012. [9] k. takahashi, et al., "high-performance inverter based on shaft acceleration torque for ac drives," ieee transactions on industrial electronics, vol. 60, pp. 66-77, january 2013. [10] l. harnefors and h. p. nee, "model-based current control of ac machines using the internal model control method," ieee transactions on industry applications, vol. 34, pp. 133-141, january/february 1998. [11] t. s. hu and c. j. yeh, "hardware implementation of the current control using the internal model method in the electric power steering application," in ieee vehicle power and propulsion conference, 2009, pp. 66-70. [12] t. miyajima, et al., "synthesis and analysis of time-optimal current trajectory based on final-state control for ipmsm," in the 10th ieee international conference on power electronics and drive systems, kitakyushu, japan, 2013, pp. 433-438. [13] p. degobert, et al., "high performance control of the permanent magnet synchronous motor using self-tuning resonant controllers," in the thirty-eighth southeastern symposium system theory, 2006, pp. 382-386. [14] v. repecho, et al., "sensorless sliding mode control of pmsm drives using a high frequency injection algorithm," przeglad electrotechniczny (electrical review), vol. 88, pp. 16-20, 2012. [15] b. bossoufi, et al., "fpgas in industrial current control for pmsm," international journal of emerging technology and advanced engineering, vol. 2, pp. 131-142, february 2012. [16] m. curkovic, et al., "fpga-based predictive sliding mode controller of a three-phase inverter," ieee transactions on industrial electronics, vol. 60, pp. 637-644, february 2013. [17] j. w. sun, et al., "a novel discrete-time predictive current control for pmsm," in iccas2005, 2005, pp. 1-6. [18] p. wipasuramonton, et al., "predictive current control with current-error correction for pm brushless ac drives," ieee transactions on industry applications, vol. 42, pp. 1071-1079, july/august. 2006. [19] f. morel, et al., "a comparative study of predictive current control schemes for a permanent magnet synchronous machine drive," ieee transactions on industrial electronics, vol. 56, pp. 2715-2728, july 2009. [20] s. mariethoz, et al., "high-bandwidth explicit model predictive control of electrical drives," ieee transactions on industry applications, vol. 48, pp. 19801992, november/ december 2012. [21] c. s. lim, et al., "model predictive control of a two-motor drive with five-leg inverter supply," ieee transactions on industrial electronics, vol. 60, pp. 54-65, january 2013. [22] s. chai, et al., "a cascade mpc control structure for a pmsm with speed ripple minimization," ieee transactions on industrial electronics, vol. 60, pp. 29782987, augustus 2013. [23] x. lin-shi, et al., "implementation of hybrid control for motor drives," ieee transactions on industrial electronics, vol. 54, pp. 1946-1952, august. 2007. [24] j.-w. jung, et al., "fuzzy pi-type current controllers for permanent magnet synchronous motors," in iet electric power applications, 2011, pp. 143-152. [25] a. v. sant, et al., "permanent magnet synchronous motor drive using hybrid pi speed controller with inherent and noninherent switching functions," ieee transactions on magnetics, vol. 47, pp. 4088-4091, october 2011. [26] j. rodriguez, et al., "state of the art of finite control set model predictive control in power electronics," ieee transactions on industrial informatics, vol. 9, pp. 10031014, may 2013. [27] a. muqorobin and p. irasari, "analisis respon motor magnet permanent pada saat pengukuran parameter elektrik," telaah, vol. 31, pp. 123-131, november 2013. [28] m. p. kazmierkowski, et al., control in power electronics selected problem. san diego: elsevier science, 2002. [29] k. ogata, modern control engineering. new jersey: prentice hall, 2002. mev j. mechatron. electr. power veh. technol. 06 (2015) 89-96 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.89-96 development of a low-cost electronic wheelchair with obstacle avoidance feature edwin romeroso arboleda*, mary christine tumambing alegre, kathleen felix idica department of computer and electronics engineering, college of engineering and information technology, cavite state university, indang, cavite, philippines received 23 january 2015; received in revised form 02 december 2015; accepted 04 december 2015 published online 30 december 2015 abstract a low-cost electronic wheelchair was designed and developed which can perform the similar functions and features as a commercially available wheelchair. it also provides obstacle avoidance capability as added value. the electronic wheelchair was realized by modification of a lightweight manual wheelchair. it uses two electric motors each of 320 w 24 v dc, 5-24 vdc 6 a h-bridge drivers, and a 12 v 17 ah rechargeable lead acid battery. it equipped with switches, joystick, infrared sensors and ultrasonic sensors. a gizduino atmega328 microcontroller is used to read and interpret commands. user’s acceptance evaluation results show that the developed low-cost wheelchair is able to receive and interpret commands provided by the joystick, detect if a person is seated on it, navigate to avoid obstacles as well as to detect edge and stairs. technical evaluation result shows that on a flat surface it could move at the speed of around 39.9 m/min without load and 32 m/min with 80 kg load. at 10 degrees inclined surface, the maximum weight limit is 30 kg with the speed of 12 m/min. at 20 degrees inclined surface, the maximum weight limit is 10 kg with the speed of 3 m/min. regarding cost, it is just a fraction of a cost compared to the commercially available model. therefore, the developed wheelchair offers an option for potential users who cannot afford to buy the commercially available one. keywords: electronic wheelchair; obstacle avoidance; edge detection; gizduino atmega328; microcontroller. i. introduction wheelchair was invented to serve as a primary means of mobility for persons with disability, those who are recuperating from illness and the elderly [1]. with the aid of wheelchairs they can move independently, can reintegrate into society as well as live productively [2][3]. the wheelchairs come in variations: manually operated wheelchairs that are propelled by the occupant by turning the large rear wheels or someone can push it through the handle in the back seat, and electrically powered wheelchairs that use motors for propulsion. through decades of development and improvement electrically powered wheelchair now uses a mobile robotic technology [4][5][6] is equipped with some navigation systems that are a combination of joystick, infrared and ultrasonic sensors, camera, and machine vision for collision avoidance and autonomous operation [7][8][9]. the most fundamental type of controller is the joystick mounted in the armrest. for others who are not capable of using a joystick, control systems using head gesture [10][11], speech [12][13], or tongue [14] may allow independent control of the wheelchair. operating a manual wheelchair usually needs another person to push it. turning the wheels by the seated occupant is difficult, considering the user’s condition. thus, assistance from others is required. in hospitals, staffs are responsible for assisting the patients whose mobility depends on the wheelchair. usually, a staff assists one patient but, with the electrically powered wheelchair, the staff would be able to assist more patients since the patients can control the wheelchair by themselves. electrically powered wheelchairs provide more convenience than the manually operated wheelchairs, but not everyone can afford to buy one since it is expensive in the market today. for this reason, the authors have *corresponding author. tel: +63-9189597934 e-mail: edwin.r.arboleda@cvsu.edu.ph http://dx.doi.org/10.14203/j.mev.2015.v6.89-96 e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 90 decided to design and develop an electronic wheelchair that can reach the general performance of electrically powered wheelchairs available in the market today but with minimal cost. this paper describes design and development of such a low-cost electric wheelchair and proposes obstacle avoidance feature as added value using appropriate sensors. user’s acceptance test, technical performance, and cost analysis are presented through questionnaire and, experiment. ii. methodology the low-cost electronic wheelchair was designed to perform functions equivalent to the commercially available wheelchairs but with minimal cost. the commercially available wheelchair does not have sensors to serve as a safety switch and to detect and avoid obstacles thus, increase the probability of users getting into accidents. in line with this, the authors considered the addition of ultrasonic and infrared collision proximity sensors to ensure the safety of the users. the microcontroller used is gizduino atmega328 [15] since it was found to fit the requirements of the design. the authors developed an electronic wheelchair by modifying a lightweight manual wheelchair. the following materials and components were installed on the wheelchair: two wiper motors, battery, battery voltage indicator, joystick, two ultrasonic sensors, one ir sensor, and the main circuit. figure 1 shows the design of the electronic wheelchair. each wheel is fixed to each motor using roller chain. subsequently, the motors were connected to the drivers and the gizduino. after the assembly, the result is a modified electronic wheelchair. table 1 shows the specifications of the major electronic parts. the navigational controller has five wires that are all connected to the gizduino circuit. likewise, two pins from each sensor were connected to the gizduino circuit. the operation of the low-cost electronic wheelchair is shown in the block diagram in figure 2. the interface between the navigational controller and sensors that were interfaced to the gizduino is shown in figure 3. the system consists of a multi directional joystick that indicates forward, backward, right and left direction commands. once the main switch of the electronic wheelchair is switched on, the battery will start to supply power to the main controller of the system that is the gizduino atmega328 with 40 ma output and the h-bridge motor driver with 50 ma output [16]. an infrared sensor placed on the right armrest that serves as a safety switch will detect whether a user is present or not. the presence of the user will trigger the infrared sensor [17] that will cause the joystick to be enabled. upon tilting the joystick forward, the 12 v wiper motor will rotate forward together with the rear drive wheels. however, if the ultrasonic sensor in front of the wheelchair detects that the wheelchair is heading towards the edge of the stairs with a distance of 0.127 meters, the electronic wheelchair will automatically stop. upon tilting the joystick backward, the 12 v wiper motor will rotate backward together with the rear drive wheels. however, if the ultrasonic sensor [18] in front of the wheelchair detects that the wheelchair is heading towards the edge of the stairs with a distance of 0.127 meters, the electronic wheelchair will automatically stop. upon tilting the joystick backward, the 12 v wiper motor will rotate backward together with the rear drive wheels. however, if the ultrasonic sensor at the rear part of the wheelchair detects that the figure 1. the design of electronic wheelchair e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 91 wheelchair is heading towards an obstacle with a distance of 0.9144 meters, the wheelchair will automatically stop upon tilting the joystick to the right, the main circuit will only allow the forward movement of the left and the right wheel to remain at rest, which makes the wheelchair move to the right. upon tilting the joystick to the left, the main circuit will only allow the forward movement of the right wheel and the left wheel to remain at rest, which makes the wheelchair move to the left. the system will continue until such time that the main switch will be switched off, or the battery will be totally discharged. iii. results and discussions figure 4 shows the developed wheelchair which consists of the following: wheelchair, joystick, two ultrasonic sensors, an infrared sensor, two wiper motors, battery, two h-bridge motor drivers, and gizduino atmega328 microcontroller that controls the whole operation of the system. if the command is to move forward, the left and the right motors will revolve clockwise simultaneously. if the command is to move backward, the left and the right motors will revolve counterclockwise simultaneously a platform was installed under the wheelchair to place the battery in the wheelchair. the battery voltage indicator was then fixed in front of the battery so that the user will be aware of the change in battery charge. the joystick was fixed to the right armrest of the wheelchair. the rocker switch that is responsible for turning the system on and off and the toggle switch that controls the speed of the electronic wheelchair to high (maximum speed) and low (minimum speed) were both attached to the joystick unit. the main circuit that consists of the gizduino and two motor drivers and an ultrasonic sensor is placed at the rear of the electronic wheelchair. an antitip table 1. capacity electronic wheelchair specifications parts specifications microcontroller 1 pc., gizduino atmega328, 14 digital input/output pins, six analog inputs, 16 mhz crystal oscillator motor 2 pcs, 320 watt 24 vdc permanent magnet motor battery 1 pc., 12 v, 17 ah rechargeable battery h-bridge 2 pcs, 5-24 vdc, 6 a e-gizmo h-bridge driver ultrasonic sensor 2 pcs, maximum detection distance = 4.5 meters infrared proximity collision sensor 1 pc., maximum detection distance = 25 cm figure 2. block diagram of the designed low-cost electronic wheelchair e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 92 was also installed to the wheelchair so that it will still be usable if the battery is completely discharged. two ultrasonic sensors and one ir sensor were installed on the wheelchair. one ultrasonic sensor is placed at the rear along with the main circuit, tilted 73 degrees to detect obstacles at the rear. the other ultrasonic sensor is placed in front of the wheelchair, tilted 88.63 degrees to avoid falling from the stairs. the ir sensor is placed on the right armrest to serve as a figure 3. schematic diagram of the circuit design e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 93 safety switch and ensure that the wheelchair will not move unless a seated occupant is present. a flowchart was made to show a succession of the electronic wheelchair operation. the software used for the programming of the system was c programming language and was loaded to the gizduino atmega328. figure 5 shows the program flowchart. to start the system operation, the rocket switch must be turned on. the system will then ask if the safety switch is on. if no, the system will end. if yes, the navigational joystick and sensors are enabled. then, the system will ask if the joystick is maneuvered forward. if yes, the system will ask if the edge detecting sensor is on. if yes, the wheelchair will stop and ask if the safety switch is off. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the edge detector is off, the wheelchair will move forward. the system will then ask if the joystick is still maneuvered. if yes, the navigational joystick and sensors are enabled, and the process is repeated. if no, the wheelchair will stop and ask if the safety switch is off. if no, the navigational joystick and sensors are enabled, and the process is repeated. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the joystick is not maneuvered forward, the system will ask if the joystick is maneuvered backward. if yes, the system will ask if the rear sensor is on. if yes, the wheelchair will stop and ask if the safety switch is off. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the rear sensor is off, the wheelchair will move backward. the system will then ask if the joystick is still maneuvered. if yes, the navigational joystick and sensors are enabled, and the process is repeated. if no, the wheelchair will stop and ask if the safety switch is off. if no, the navigational joystick and sensors are enabled, and the process is repeated. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the joystick is not maneuvered backward, the system will ask if the joystick is maneuvered to the right. if yes, the wheelchair will move to the right. the system will then ask if the joystick is still maneuvered. if yes, the navigational joystick and sensors are enabled and the process is repeated. if no, the wheelchair will stop and ask if the safety switch is off. if no, the navigational joystick and sensors are enabled, and the process is repeated. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the joystick is not maneuvered to the right, the system will ask if the joystick is maneuvered to the left. if yes, the wheelchair will move to the left. the system will then ask if the joystick is still maneuvered. if yes, the navigational joystick and sensors are enabled, and the process is repeated. if no, the wheelchair will stop and ask if the safety switch is off. if no, the navigational joystick and sensors are enabled, and the process is repeated. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. if the joystick is not maneuvered to the left, the wheelchair will stop and ask if the safety switch is off. if no, the navigational joystick and sensors are enabled, and the process is repeated. if yes, the wheelchair will turn off, and the joystick will be disabled. the program will then end. evaluation of the developed wheelchair has been conducted through user’s acceptance test, technical test, and cost analysis. results of these evaluations are presented and discussed as follows. the authors conducted user’s acceptance evaluation for the electronic wheelchair using a survey questionnaire involving 30 persons with disability (pwd) participants categorized with (a) (b) figure 4. the developed electronic wheelchair; (a) front view; (b) back view e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 94 their weights. the weight categories are divided into four, namely: weight category a (88 – 109.9 lbs.), b (110 – 131.9 lbs), c (132 – 153.9 lbs.) and d (154 – 175.9 lbs.). seven questions were prepared to evaluate the low-cost electronic wheelchair: (1) the electronic wheelchair is easy to use, (2) it runs smoothly, (3) the joystick works properly (4) the sensor that serves as safety switch works properly, (5) the sensor in the front part of the electronic wheelchair is effective for avoiding the stairs, (6) the rear sensor is effective for avoiding collisions, and (7) all the parts of the electronic wheelchair is functioning. each question were rated using the following likert scale: 4.5-5.0 = excellent; 3.54.49 = satisfactory; 2.5-3.49 = fair; 1.5-2.49 = needs improvement; 1-1.49 = poor. start main switch is on? safety switch is on? joystick and sensora are enabled a d no yes a no b yes joystick maneuvered forward? joystick maneuvered backward? joystick maneuvered to the right? joystick maneuvered to the left? b no no no no edge detecting sensor is on? yes obstacle detecting sensor is on? b yes wheelchair will move forward no wheelchair will move backward wheelchair will move to the right yes no wheelchair will move to the left yes joystick still maneuvered? c wheelchair will stopb no yes safety switch is off? c no yes main switch is off? d no end a yes yes c figure 5. the system flowchart e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 95 the overall mean for the performance of the low-cost electronic wheelchair is 4.5286. therefore, the overall evaluation of the project is excellent. it is concluded that the low-cost electronic wheelchair is accepted by pwd users with regards to the weight category they belong to. technical evaluation was conducted by measuring speed of the wheelchair as a function of load and inclination. figure 6 shows the speed performance of the wheelchair. on a flat surface, it can move at the speed of around 39.9 m/min without load and 32 m/min with 80 kg load. at 10 degree inclined surface, the maximum weight limit is 30 kg with the speed of 12 m/min. at 20 degree inclined surface, the maximum weight limit is 10 kg with the speed of 3 m/min. the cost analysis was done by comparing the specifications of the low-cost electronic wheelchair with the three models of commercially available ones (rear wheel drive, medalist power, and rear wheel drive power). the cost analysis result is shown in table 2. table 2. cost analysis result function model 1 (php 15 665.00) model 2 (php 65 250.00) model 3 (p 351 000.00) model 4 (p 450 000.00) low-cost electronic wheelchair rear wheel drives wheelchair medalist power chair rear wheel drives power chair transports the user comfortably √ √ √ √ transports a user with a weight of at least 50 kg √ √ √ √ transports user to an inclined surface √ √ √ √ has sufficient speed √ √ √ √ has adjustable speed √ √ √ √ has good battery charge capacity √ √ √ √ detects and avoids obstacles √ √ √ √ detects and avoids stairs edge √ √ √ √ includes an alternative rear-wheel for manual operation √ √ √ √ includes safety switch that makes the wheelchair unusable when no seated occupant is present √ √ √ √ figure 6. speed of the electronic wheelchair as affected by floor inclination and weight of load e.r. arboleda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 89-96 96 iv. conclusion based on the results gathered throughout the study, it can be concluded that a low-cost electronic wheelchair has been successfully developed. through testing and evaluation with 30 pwd participants having different weights, the overall performance of the wheelchair is excellent. its performance is equivalent to the commercially available electric wheelchair but is less in cost. moreover, it has added values such as the infrared sensor as the safety switch and ultrasonic sensors for obstacle avoidance and edge (stairs) detection. some recommendations for further improvement are: remote control may be added to the additional navigational controller so that navigation will be possible to users who cannot stretch their arms, and add buzzers for obstacle indication to alert the user. acknowledgement the authors gratefully acknowledge the training grant abroad provided to one of them by dost-pcieerd. references [1] r. a. cooper, “wheelchair research progress, perspectives, and transformation,” j. rehabil. res. dev., vol. 49, no. 1, pp. 1 – 5, 2012. [2] v. de s. p. costa et al., “social representations of the wheelchair for people with spinal cord injury,” rev. latinoamericana enferm., vol. 18, no. 4, pp. 755– 762, 2010. [3] h. nunome et al., “a kinematic study of the upper-limb motion of wheelchair basketball shooting in tetraplegic adults,” j. rehabil. res. dev., vol. 39, no. 1, pp. 63 – 71, 2002. [4] b. daveler et al., “participatory design and validation of mobility enhancement robotic wheelchair.,” j. rehabil. res. dev., vol. 52, no. 6, pp. 739–50, jan. 2015. [5] b. jenita amali rani and a. umamakeswari, “electroencephalogrambased brain controlled robotic wheelchair,” indian j. sci. technol., vol. 8, no. s9, p. 188, may 2015. [6] e. perez et al., “robotic wheelchair controlled through a vision-based interface,” robotica, vol. 30, no. 05, pp. 691–708, aug. 2011. [7] y. ji et al., “an intelligent wheelchair using situation awareness and obstacle detection,” procedia soc. behav. sci., vol. 97, pp. 620–628, nov. 2013. [8] m. r. m. tomari et al., “development of smart wheelchair system for a user with severe motor impairment,” procedia eng., vol. 41, pp. 538–546, 2012. [9] r. a. m. braga et al., “intellwheels: modular development platform for intelligent wheelchairs,” j. rehabil. res. dev., vol. 48, no. 9, p. 1061, jan. 2011. [10] z. yi et al., “intelligent wheelchair system based on semg and head gesture,” j. china univ. posts telecommun., vol. 22, no. 2, pp. 74 – 80, 95, 2015. [11] r. tomari et al., “analysis of socially acceptable smart wheelchair navigation based on head cue information,” procedia comput. sci., vol. 42, pp. 198 – 205, 2014. [12] a. škraba et al., “speech-controlled cloudbased wheelchair platform for disabled persons,” microprocess. microsyst., vol. 39, pp. 819–828, 2015. [13] n. peixoto et al., “voice controlled wheelchairs: fine control by humming.,” comput. methods programs biomed., vol. 112, no. 1, pp. 156–65, oct. 2013. [14] l. n. s. a. struijk, “an inductive tongue computer interface for control of computers and assistive devices.,” ieee trans. biomed. eng., vol. 53, no. 12 pt 2, pp. 2594–7, dec. 2006. [15] e-gizmo mechatronix central, “gizduino version 5 w/atmega328p .” [online]. available: http://www.egizmo.com/kit/gizduinov.html. [accessed: 05-dec-2015]. [16] e-gizmo mechatronix central, “6.0a hbridge motor driver.” [online]. available: http://www.e-gizmo.com/kit/hbd6.htm. [accessed: 05-dec-2015]. [17] e-gizmo mechatronix central, “infrared proximity-collision sensor.” [online]. available: http://www.egizmo.com/kit/collision.ht m. [accessed: 05-dec-2015]. [18] e-gizmo mechatronix central, “us-100 ultrasonic sonar.” [online]. available: http://www.e-gizmo.com/kit/sonar.htm. [accessed: 05-dec-2015]. mev mechatronics, electrical power, and vehicular technology 05 (2014) 99-106 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.99-106 adhesion detection analysis by modeling rail wheel set dynamics under the assumption of constant creep coefficient zulfiqar ali soomro a, * a directorate of post-graduate studies, mehran university of engg & tech jamshoro (sindh) pakistan received 21august 2014; received in revised form 14 november 2014; accepted 14 november 2014 published online 24 december 2014 abstract adhesion level control plays significant role in order to keep smooth running of a train. to design a proper adhesion controller, adhesion dynamics needs to be analyzed. in this paper adhesion is analyzed by modeling rail wheelset dynamics under the assumption of constant creep coefficient. equations of creepage and creep forces were derived in longitudinal, lateral and angular directions. numerical simulation was conducted under assumption of constant creep coefficient. the creep coefficient was obtained by applying coulomb’s law of friction. from the simulation results it can be concluded that adhesion level for suitable dynamic model determination depends on assumption of creep analysis to avoid slip or derailment of rail wheelset. keywords: adhesion, rail wheel set, creep coefficient, longitudinal, lateral. i. introduction the study of railway vehicle braking is important to investigate in-train forces, ride comfort, safe operation, braking distance and time, and vehicle speed. modeling the longitudinal dynamics of trains is important to understand the behavior of rail vehicles while in operation. this can also help with better understanding the effects of braking forces and other forces and moments that resist the forward motion of the train. improving dynamic braking forces result in shorter train stopping distance [1-3]. train speed control and train braking estimations are required to prevent train accidents. ptc is a gps-based technology that is designed to prevent train collisions and derailments, and to control train movements along the track. ptc requires understanding the longitudinal train dynamics while operating on the railway network [2, 4]. the interaction forces between the wheel and the rail have a significant effect on the dynamic behavior of the railway vehicle. adhesion, creep, and wear have significant importance on the railway vehicle dynamics. the adhesion relies upon the environmental conditions and rough surfaces. creep forces depend upon the wheel dimensions and the rail profile, as well as the materials of the wheel and the rail. in order to calculate the creep forces, wheel/rail contact mechanics must be studied [5]. polach found that large creep forces mainly occur in the longitudinal direction at the time of traction or braking [6]. measurements were modeled for five types of locomotives under different weather and wheel/rail conditions [7]. also, adhesion tests under various speeds and contamination conditions were carried out using a full-scale roller rig in [8]. the results conclude that the adhesion coefficient has high values for dry and clean surfaces and does not change much for all ranges of speeds. it also has low values for oil contamination conditions and does not change much for all ranges of speeds. the longitudinal rail dynamic model is a twodimensional model that is used to study the forward motion of the train [9]. a simple model of the longitudinal dynamics of a long freight train was developed [10, 11]. each group of researchers has focused on longitudinal train dynamics from different perspectives. * corresponding author.tel: +92-304-0298529 e-mail: zulfiqarali_s@yahoo.com mailto:zulfiqarali_s@yahoo.com http://dx.doi.org/10.14203/j.mev.2014.v5.99-106 z. a. soomro / mechatronics, electrical power, and vehicular technology 05(2014) 99-106 100 the study of the longitudinal train model leads the better concept of the effects upon various conditions and different retardation of the forces which act upon the train dynamics. the behavior of the longitudinal train dynamics is analyzed upon applicationof control design. a railcar model was developed to study wagon body pitch, derailment, and wheelset skid during braking [12]. this model showed that suddenly applying large braking or traction forces can cause wheel skid. also, it is mentioned in the study that track defects play an important role in increasing pitch. the longitudinal dynamic behavior of a train is a function of brake forces and track geometry. wheel rail interaction forces consist of propulsion resistance and railcar connection. a multibody formulation of the train longitudinal dynamics results in a set of differential equations for each carbody, truck and wheelset. when considering train dynamics, most researchers ignore the vertical and lateral movements, as well as the suspension forces. references [13, 14] extended its application to a more general case. at the delft university, kalker performed his studies applying the limitations as low as possible, conceiving an elliptical contact area with the simultaneous presence of the creepage λx (longitudinal), λy (lateral) and λψ (spin) [15, 16]. so many theories and algorithms invented procedure as the knowledge based foundation of the modern rail wheelset contact theories [17]. in this paper, creep force analysis is discussed and simulated for dynamic modeling of train for detection of adhesion level to avoid slip. ii. dynamics of rail wheelset kalker suggested that the motion is a rigid body motion in the plane of rail wheel contact, i.e., the common tangential plane of wheel and rail, and that the velocity corresponding to this motion is the translational and a rotational about the common normal at the centre of the contact area, which is taken about the z axis [16]. in general, the wheel and rail surfaces can be pressed against each other tangentially displaced and rotated [18]. a. creep forces on wheel set the kinematic representation of the wheelset (klingel formula) has, for a long time been used to explain the sinusoidal behavior of a free wheelset, but the situation is different under a real vehicle. the real wheelset is strongly linked to the vehicle through flexible suspension elements, and these links creates significant forces when the wheelset is entering a curve or running on a real track with irregularities. the suspension forces find their reaction forces (normal and tangent) at the rail – wheel contact interface, where the tangent components or creep forces are related to the relative speed between the two bodies (creepages). in the contact coordinate systems, the forces are denoted, ‘n’ for the normal forces, ‘fx’ for the longitudinal creep force, ’fy’ for the lateral creep force in the contact plane [18, 19]. in figure 1, the inner and outer diameters (do and dr) are shown along with concity γ, and spin moment mz is shown with prescribed creep forces. figure 1.creep forces and geometry of wheelset z. a. soomro / mechatronics, electrical power, and vehicular technology 05 (2014) 99-106 101 b. velocities and creepages figure 2 shows parameters which are used to analyze relative motions and creepages between wheel and track. 1) longitudinal creepage the wheel profile is conned then longitudinal creep arises when there is a difference in the rolling radii of the two wheels of the wheelset. the longitudinal creepage is defined as follows [20]: v vv x 1 1 1 1    (1) where , , and represent forward velocity of wheel, forward velocity of rail, and pure rolling forward velocity, respectively. 2) lateral creepage it is defined as the quotient between the lateral components of the relative velocity of the contact points i.e. the lateral slip velocity and the wheel forward velocity. the lateral creepage has a significant effect upon the rails corrugations caused by the lateral creepage forces. furthermore, the stick-slip phenomenon can be supposed to be induced between a resultant of mainly lateral and longitudinal creepage force. v vv y 2 1 2 1    (2) where and represent lateral velocity of wheel and lateral velocity of rail, respectively. 3) spin creepage the spin creepage is due to the component of the relative angular velocity of the two bodies normal to the contact surfaces. generally speaking, the angular velocity of a wheel relative to the rail can be ecomposed into three components; one of them is perpendicular to the contact plane, while the other two are tangent to the plane of contact. however pure rolling occurred when the rolling occurs without sliding or spin [21]. v 33     (3) where and represent forward velocity of wheel and forward velocity of rail, respectively. two tangential velocities along x and y axes called rolling velocity. the x-velocity contains the rolling velocity of the vehicle, to which is added some perturbing motions, while the yvelocity contains only perturbations. we can assume that the x component is much larger than the y. a displacement parallel to the z axes given by δ such displacement is called compression if δ < 0, and loss of contact if δ > 0 [17]. one rotation around the z axis is angular velocity about z. the difference between them is called spin. the spin, divided by the rolling velocity is called spin creepage. the longitudinal creepage can confers through the difference in the effective rolling radii of the wheels, left and right, due to the conicity, through acceleration or braking couples and through the rotation of the yaw angle by which the left wheel moves with a different velocity over the rail than the right wheel. c. creep modeling upon left rail wheel angular left wheel velocity wl and forward left wheel velocity v are given by )r+ v/(r=w oll and ol r* w= v where rl denotes inner radius of left wheel. the concerned velocities in longitudinal, lateral and spin are as follows. longitudinal creepage of left wheel: v)/v]-w*[(r = loxl  (4) lateral velocity is given by  *vy , where rad 0.9250= (constant value for spin wheel). lateral creepage of left wheel:  -/v)y( = yl  (5) figure 2. velocity analysis acting upon wheel and track z. a. soomro / mechatronics, electrical power, and vehicular technology 05(2014) 99-106 102 yaw (spin) velocity of left wheel: vw ll / (6) the longitudinal creep force on left wheel is: xlxl ff  11  (7) the lateral creep force on left wheel is: ylyl ff  22  (8) the spin moment creep force on right/left wheel is: ll ff    23 (9) d. creep modeling uponright rail wheel angular right wheel velocity wr and forward rightwheel velocity v are given by )r+ v/(r=w orr and or r* w= v where rr denotes inner right wheel radius. longitudinal creepage of right wheel is: v)/v]-w*[(r = roxr  (10) lateral velocity is given by  *vy , where rad 0.9250= . lateral creepage of right wheel equals to the lateral creep of left wheel:  -/v)y( = yr  (11) yaw (spin) velocity of right wheel: vw rr / (12) total longitudinal creepage: xrxlx   (13) total lateral creepage (λl): yryly   (14) total spin (yaw) creepage: rl    (15) thus combining all the above creepages we get total creepage of rail wheelset as below:    22 yx (16) the longitudinal creep force on right wheel is: xrxr ff  11  (17) the lateral creep force on right wheel is: yryr ff  22  (18) the spin moment creep force on right wheel is: rr ff    23 (19) total creep forces:   ffff yx (20) where f11, f22 and f23 are the creep coefficient of longitudinal, lateral and spin moment. iii. application of coulomb’s law coulomb’s law holds in limited usage and range with approximate to detect coefficients of friction of sliding [13]. it determines the angle of friction and repose by comparing tangential and normal forces. it describes the following relations: cos..gmf n  (21) sin..gmf t  (22) it states that: nt ff . (23) means the body is in rest that there is no any slip. and if nt ff . , then there is slip. putting values from equations (21 and 22) into equation (23) we get  cos..sin.. gmgm  hence α = tan -1 μ .thus μ =tan (α), it further explains that nt ff . means left sliding and if nt ff . means right slidingon motion. where ft is total tangential force, fn is normal force and gmw . . iv. results and discussion since the friction between rail track and wheelset is very complicated and difficult problem, here we have focused on simple approximation to apply coulomb’s law of sliding friction with known coefficient of friction or creep co-efficient. in the real world, this assumption is applicable hence we can sustain to walk based on the second law of motion. if there would have not been friction, everything would have been slippery. mathematical dynamics are simulated by using matlab ® . the results are plotted in the following graphs. here longitudinal, lateral and yaw velocities are applied upon each wheel of rail wheelset to check their behavior over dynamics and running for rail vehicle on track. similarly concerned creep forces in major directions are acted upon each z. a. soomro / mechatronics, electrical power, and vehicular technology 05 (2014) 99-106 103 wheelset. thus through these analysis, the level of adhesion is detected to avoid slip from derailment. in the 1 st part of figure 3, the velocities working in three directions have been shown. the blue line representing velocity in longitudinal direction starts above 0 with a little rise upward to end at 40 m/s. similarly the green line denoting velocity in lateral direction starts from same destination along with and a little bit lower than longitudinal line to end at same stop. whereas the red line denoting the yaw velocity starts from 0 and falls gradually lower than 0 to end at -18 rad/s in 1.4 seconds, like the previous lines of longitudinal and lateral velocities. in the 2 nd part of figure 3, the creep forces working in mentioned three directions have been shown. the blue line representing force in longitudinal direction starts above 0 with a little rise upward linearly to end at 4e+6 mn. similarly green line denotes force in lateral direction falls linearly from same destination lower than longitudinal line to ends below 0 in 1.4 seconds. whereas red line denotes the yaw force starting from 0 and falls gradually lower than 0 to end at nearly -4.8 mn in 1.4 seconds. similarly spin moment start from 0 in straight line linearly without any change which reflects the idea that yaw rate are the same among longitudinal and lateral velocities. in the 3 rd part of figure 3, total creepage is compared with longitudinal force of left to detect the adhesion level to protect from slippage. here the curve starts from 0 to travel linearly in straight path up to 3e+6 mm/s in 0.63 seconds. this denotes that adhesion level is increased to control slip. this straight line represents maximal coulomb’s law for friction in contact surfaces. in the 1 st part of figure 4, the velocities working in three directions have been shown. the blue line representing velocity in longitudinal direction starts above 0 with a little rise upward to end at 100 m/s. similarly the green line denotes velocity in lateral direction starts from same destination along with a little bit lower than longitudinal line to end at same stop at 1.4 seconds. whereas red line denotes the yaw velocity starts from 0 and falls gradually lower than 0 to end at -45 rad/sec in 1.4 seconds, like previous lines of longitudinal and lateral velocities. in the 2 nd part of figure 4, the creep forces working in mentioned three directions have been shown. the blue line representing force in longitudinal direction starts above 0 with a little rise upward linearly to end at 4 n in 1.4 seconds. similarly green line denotes force in lateral direction falls linearly from same destination lower than longitudinal line to ends below 0 in 1.4 seconds. whereas red line denotes the yaw velocity starts from 0 and falls gradually lower than 0 to end at nearly -4.8 n in 1.4 seconds. similarly spin moment start from 0 in straight line linearly without any change which reflects figure 3. action of velocities, creep forces and detection of adhesion on left wheel z. a. soomro / mechatronics, electrical power, and vehicular technology 05(2014) 99-106 104 the idea that yaw rate are the same among longitudinal and lateral velocities. in the 3 rd part of figure 4, total creepage is compared with longitudinal force of right wheel to detect the adhesion level to protect from slippage. here the curve starts from 0 to travel linearly in straight path up to -2e+6 mm/s in 0.35 seconds. this denotes that adhesion level is increased to control slip. this straight line represents maximal coulomb’s law for friction in contact surfaces. in the 3 rd part of figure 5, total creepage is compared with spin moment force of wheel set to detect the adhesion level to protect from slippage. figure 5. behavior of total 3d creep forces and creepage to detect adhesion on wheelset figure 4. action of velocities, creep forces and detection of adhesion on right wheel z. a. soomro / mechatronics, electrical power, and vehicular technology 05 (2014) 99-106 105 here the black line representing adhesion level starts from 0 to 5,000 mn of yaw forces linearly in straight path with vertical to 5.1 n total creepage horizontally. this denotes that when spin force rises with increase of total creepage, hence adhesion level is increased to control slip. this straight line represents maximal coulomb’s law for friction in contact rough surfaces. here μ = 0.15 and ft = -8.5622e+005. by substituting into equation (23) and after rearrangement we get fn = ft/μ = -5.7082e+006 which is greater than ft but μ.fn is equal to ft. it demonstrates that there is small ratio of overall slip. to determine entire adhesion for verifying slip ratio this model is good enough to explore relative problems, and perform smoothly. from whole discussion it can be observed that this designed model helps to detect adhesion level to control precautionary steps from incident of slip from huge accidents. this dynamic model paves path to invent adhesion measuring instrument to avoid slip depending upon creep forces and velocity analysis v. conclusion in above analysis, the railway wheelset model was taken to enumerate its concerned dynamics to calculate the creep forces and creepage acting upon it. the velocities of wheelset and rail track were assumed and discussed on each rail wheel to compute the creep forces in main directions i.e. longitudinal, lateral and spin. thus total creep forces of these three dimensions were compared with total creepage of these directions to identify the level of adhesion for escaping from slip to avoid derailment of rail vehicle. coulomb’s law for sliding friction was used to verify the validation of the linear model. the modeling and simulation by matlab ® is well sufficient to detect the adhesion manually too. references [1] h. ahmad and m. ahmadian, "train braking distance estimation under different operating conditions," in asme 2011 rail transportation division fall technical conference, minneapolis, minnesota, usa, 2011. [2] h. ahmad and m. ahmadian, "model reference adaptive control of train dynamic braking," in asme 2012 joint rail conference, philadelphia, pennsylvania, usa, 2012. [3] (2013, july). federal railroad administration. available: http://www.fra.dot.gov [4] (2013). association of american railroads. available: www.aar.org [5] v. k. garg and r. v. dukkipati, dynamics of railway vehicle systems: academic press, 1984. [6] o. polach, "a fast wheel-rail forces calculation computer," veh. syst. dyn. suppl., vol. 33, pp. 728-739, 1999. [7] w. zhang, et al., "wheel/rail adhesion and analysis by using full scale roller rig," wear, vol. 253, pp. 82-88, 2002. [8] l. pugi, et al., "modelling the longitudinal dynamics of long freight trains during the braking phase," in 12th iftomm world congress, france, 2007. [9] z. zhang and m. dhanasekar, "dynamics of railway wagons subjected to braking/traction torque," vehicle system dynamics, vol. 47, pp. 285-307, 2009/03/01 2009. [10] s. iwnicki and a. h. wickens, "validation of matlab vehicle simulation using a scaled test rig," vehicle system dynamics, vol. 30, pp. 257-270, 1998. [11] s. iwnicki, handbook of railway vehicle dynamics: taylor & francis, 2006. [12] a. a. shabana, et al., "a multi-body system approach for finite-element modelling of rail flexibility in railroad vehicle applications," proceedings of the institution of mechanical engineers, part k: journal of multi-body dynamics, vol. 222, pp. 1-15, march 1, 2008 2008. [13] j. pombo, "a multibody methodologyfor railway dynamics applications," phd thesis, instituto superior t´ecnico, universidad t´ecnica de lisboa, 2004. [14] a. shabana and j. sany, "a survey of rail vehicle track simulations and flexible multibody dynamics," nonlinear dynamics, vol. 26, pp. 179-212, 2001/10/01 2001. [15] j. j. kalker, "a strip theory for rolling with slip and spin," in proceedings kon. ned. akad. van wetenshappen, 1967. [16] j. j. kalker, three-dimensional elastic bodies in rolling contact: dordrecht: kluwer academic publishers, 1990. [17] m. ishida, et al., "the effect of lateral creepage force on rail corrugation on low rail at sharp curves," wear, vol. 253, pp. 172-177, 2002. z. a. soomro / mechatronics, electrical power, and vehicular technology 05(2014) 99-106 106 [18] i. y. shevtsov, et al., "optimal design of wheel profile for railway vehicles," wear, vol. 258, pp. 1022-1030, 2005. [19] i. y. shevtsov, et al., "design of railway wheel profile taking into account rolling contact fatigue and wear," in 7th international conference on contact mechanics and wear of rail/wheel systems (cm2006), brisbane, australia, 2006, pp. 667-674. [20] p. gaspar, et al., "observer based estimation of the wheel-rail friction coefficient," in 2006 ieee international conference on control applications, munich, germany, 2006, pp. 1043-1048. [21] y. zhao, et al., "estimation of the friction coefficient between wheel and rail surface using traction motor behaviour," journal of physics: conference series, vol. 364, p. 012004, 2012. mev mechatronics, electrical power, and vehicular technology 05(2014) 91-98 mechatronics, electrical power, andvehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.91-98 learning efficiency of consciousness system for robot using artificial neural network osama shoubaky a, *, tala m. sharari b ªcomputer and intelligent systems center, po.box. 2150, jordan b institute of engineering &technology, department of electrical engineering, control laboratory and automation, po.box. 81, jordan received 26 october 2014; received in revised form 22 november 2014; accepted 23 november 2014 published online 24 december 2014 abstract this paper presents learning efficiency of a consciousness system for robot using artificial neural network. the proposed conscious system consists of reason system, feeling system and association system. the three systems are modeled using module of nerves for advanced dynamics (modnad). artificial neural network of the type of supervised learning with the back propagation is used to train the modnad. the reason system imitates behaviour and represents self-condition and other-condition. the feeling system represents sensation and emotion. the association system represents behaviour of self and determines whether self is comfortable or not. a robot is asked to perform cognition and tasks using the consciousness system. learning converges to about 0.01 within about 900 orders for imitation, pain, solitude and the association modules. it converges to about 0.01 within about 400 orders for the comfort and discomfort modules. it can be concluded that learning in the modnad completed after a relatively small number of times because the learning efficiency of the modnad artificial neural network is good. the results also show that each modnad has a function to imitate and cognize emotion. the consciousness system presented in this paper may be considered as a fundamental step for developing a robot having consciousness and feelings similar to humans. keywords: consciousness, robot, artificial neural network. i. introduction consciousness has been studied extensively in brain science, neural science, psychology, philosophy, others academic fields and recently in robotics [1-9]. various robots that can communicate with consciousness and feeling functions have been reported by many researchers and companies [10-18]. the actroid robot is one of them [1], however it cannot talk to others cleverly because it lacks human-like consciousness and feelings. the we-4r ii robot of waseda university reportedly has the functions for feelings [2]. emotional equation is used in this robot system. this robot is different from the robot proposed in this paper which expresses emotion using artificial neural models of the consciousness system. moreover, this paper reports not only emotion but also the function of consciousness. both human consciousness and emotion are being actively studied and interesting researches have been reported in various fields [14-18]. nevertheless, no paper has ever elucidated the relationship between emotions and consciousness. the present paper proposes a computational model capable of realising the function of emotion and reports on the experiments from which robots learn the imitation behaviour. the emotions are assumed to be cognised by imitating others behaviour. this will be able to cause advanced self-cognition and other-cognition. the relationship between consciousness and imitation behaviours, self-cognition, and other-cognition is discussed in the next section. consciousness is generally considered to be the state when one is paying attention to something, thinking, or awake. with a focus on the imitation function of humans, this paper * corresponding author. phone:+962-0778679772 e-mail: o.shoubaky@yahoo.com http://dx.doi.org/10.14203/j.mev.2014.v5.91-98 o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 92 defines consciousness to arise from “a consistency of cognition and behaviour.” based on this belief, this paper presents a devised module for the consciousness system named module of nerves for advanced dynamics (modnad). in addition, by the modnad, most of husserl’s ten functions of consciousness can be accounted for [8]. a strong relationship was found between consciousness and imitation based on four important instances of consciousness: mirror neuron, mimisis theory [3-5], medical cases of imitation behaviour [6], and a study of imitation behaviour [7, 12]. the immediate objective of the present study is the realisation of selfconsciousness. as the first step inthe study, there was an attempt to realise the function of imitation and verify whether self-cognition coud be realized based on feedback information regarding the condition of self and the other. an implementation of self-consciousness must need self-cognition. first, other and self conditions are represented by imitating others behaviours with the consciousness system. second, the representations of self and others are compared. if other representation is similar to self representation, the other is more-self-like. during the imitation experiments for the consciousness system, a great interest was given to how an autonomous robot behaved when it confronted difficulty caused by harmful obstacles. this theme has a close relationship with emotion. emotion is generally said to have the following three features [8, 9], as follow: 1. emotion is evoked by internal information representing a change in the condition of the body or by external information. for example, one feels pain upon hitting something, or feels bad when one’s stomach is upset 2. emotion plays the role of an adjuster in the body. this is particularly important for understanding the homeostasis function [8] 3. emotion helps people to reason and make choices. based on these observations, with regard to feelings of discomfort, a new hypothesis is proposed considering in which emotions are generated by internal or external information to the body, they make people pay attention to the cause of the discomfort, and assist the person to avoid the discomfort-causing behaviour, eventually enabling the person to avoid harmful damage using this assistance. by implementation of the emotional function, self-cognition and other-cognition will be able to make further progress. this will enable robots to possess human-like sociality. ii. outline of the consciousness system a. modnad structure the consciousness module "modnad" is a consciousness computational model using neural networks. shown in figure 1, modnad consists of the cognition system (a), behaviour system (b), primary representation (c) which is common area of cognition and behaviour systems, and symbolic representation (d), and input/output units (a/b). symbolic representation has cognition representation rl, which represents what modnad cognises now, and behaviour representation bl, which represents symbol how modnad will behave next. these two representations serve as the communication terminals for the higher-level modules. without information transmitted from the higher-level module, the information of cognition representation rl is basically copied to behaviour representation bl. the most important feature of modnad is primary representation, the common area for the cognition and the behaviour system. primary representation enables the system to learn behaviour while it cognises and, conversely, to learn cognition while the system behaves. it is also possible torealise artificial thought and expectation using modnad. because the feedback b’ as somatic sensation is in this system, therefore, self-condition can be grasped more. b. general concept of the system figure 2 shows a conceptual model of the consciousness system proposed in this paper. an important feature of the system is that it consists of multiple modnads. the major components of the consciousness system are the reason, feelings and association system. the reason system cognises the external environment based on information received from the input unit (figure 2 (1)). the output unit performs the decided behaviour. the reason system has a hierarchical structure of modnads. figure 1. modnad concept model o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 93 the feelings system represents feelings based on information from the external environment and the internal environment reflecting bodily changes (figure 2 (1), (2)). the feelings system is also a hierarchical structure of modnads. the highest layer of the feelings system holds two modules corresponding to comfort and discomfort. another important feature of the consciousness system is that information from the reason system is also used in cognising comfort or discomfort. information from the reason system (cognised language label) is input into the comfort and discomfort modules (figure 2 (3)). the reason system and the feelings system exchange information between higher and lower levels using their hierarchical structures. the association system receives two inputs: information cognised in the reason system and the condition of self as understood by the feelings system (figure 2 (4), (5)). based on these two pieces of information, the association system determines the behaviour that will make self comfortable. to reflect the decision on the behaviour of the robot the association system produces information to the reason system and the feelings system (figure 2 (6)). this functioning of the association system modifies the representation of both the reason and feelings systems and, eventually, the reason system outpu the command to perform a certain behaviour that makes the robot comfortable (figure 2 (7)). at this time, the association system is not a so-called homunculus because the modnad of the association system is driven by information from the lower-level modnads. . iii. development of conscious system this section describes the learning functions of each of the reason, feelings and association systems. fundamental construction of the modnad is shown in figure 3. as shown in figures 4, 5 and 6, the modnad is applied to the implementation of the emotional and associating function. figure 3 also shows the network in the reason system to imitate for representing self and other condition. figure 4 shows the lower-level networks in the feelings system to represent feeling of pain from internal information. figure 5 shows the higher-level network in the feelings system to represent feeling of comfort from the lower-level emotional representation. figure 6 shows the network in the association system to give support figure 2. consciousness system concept model figure 3. modnad computational model and imitation behaviour module figure 4. pain module of consciousness system figure 5. comfortable module of consciousness system figure 6. the association module of the consciousness system o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 94 to decide next action from the comfortable and uncomfortable representation, the representation of self-cognition and other-cognition. in this paper, the differences of the network form are considered. the networks in the feelings system do not have output unit m because they are used mainly to represent self condition. but an information flow circulates from primary representation to symbolic representation, and it can change emotional condition and the representation. this change will generate emotional thinking. the association network does not have feedback, m’. the reason is that the association network is the higher-level modnad and does not have motors as somatic sensation. this network also has circulation, so it capable in implementing thought. a. consciousness system for self-cognition figure 7 shows an overall image of the consciousness system developed for conducting experiments on mirror image cognition. module a, the reason system, imitates behaviour based on external information from the infrared (ir) sensor and represents self-condition and othercondition. modules b through e make up the feelings system: b represents “pain” based on internal information or an error detected by pid control; c represents “solitude” from the value of the ir sensor; d and e receive the values of representation from modules a, b, and c represent the emotions of “comfort” and “discomfort”, respectively. module f is the association system. three behaviours of advance, stop and retreat are used in the robotic experiments. just one module a is used in the reason system but two or more modules may be used for robots requiring more complex motions. the robot used in the experiments is khepera2. these robots have infrared sensors and motors of pid control. the robot is assumed to have two sensations of pain and solitude in the experiment. the reason why the error detected by pid control gives pain to the robot and why the sensor condition generates solitude is described below. this paper focused on the fact that emotion plays a role of adjuster in the body. when no error is detected by pid control, the robot moves at the set speed. when the error detected by pid control increases, some fault such as friction is present and the actual speed decreases to below the set speed. this increases the load on the motor, and the robot thinks the speed must be adjusted, which gives pain to the robot. the present consciousness system is designed to imitate behaviours and learn self-cognition using emotions. if the sensor does not react, the robot cannot learn, making self-cognition impossible. if no information arrives at the sensor, discomfort results causing solitude. pain and solitude prevent the robots from imitating for self-cognition, which is discomfort. this section describes the flow of information through the consciousness system that performs self-cognition (figure 7). the value of the infrared sensor for capturing external information is input into terminals in1 and in3. any error detected by pid control representing internal information is input into terminal in2. in the symbolic representation of imitation module a, behaviour of self and the other is cognised from the external information input into in1 and from the somatic sensation of a. using information from in2 and in3, the degree of pain and solitude is matched to one of four stages of language labels at the symbolic representations b and c, respectively. as a result of the cognition of behaviour of self and the other at a, the degree of pain and solitude determined at b and c are respectively input as comfort and discomfort into modules d and e via p1, p2 and p3. similarly, in the comfort and discomfort modules, the degree of comfort and discomfort is matched to one of four stages of language labels at the symbolic representation. the result of the cognition by the module of imitation at a and the degree of comfort and discomfort respectively determined at d and e are eventually input into module f via p4, p5 and p6 to associate information from the reason system and the feelings system. the association system module f represents at a-rl (figure 6) the behaviour of self and whether self is comfortable or not at the present moment as determined by the result of the cognition by the imitation module and the degree of comfort and discomfort determined. this information from cognition representation a-rl is copied to the behaviour representation a-bl (figure 6). figure 7. consciousness system for self-cognition o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 95 as a result, the association system module f transmits information to module a via p7, enabling it to change the “expectation of behaviour” generated in the cognition-byimitation process of module a. this means that the reason system is dictated to prepare the next behaviour according to the condition of the feelings system of self at the present moment. if a-rl of the module f represents discomfort, module f transmits to the lower-level module information by which the lower-level reason module will invite discomfort as a result of behaviour. if a-rl of module f represents comfort, module f transmits to the lower-level module information by which the lower-level reason module will allow comfort to continue as a result of behaviour. information determined by the association system module f is transmitted to the feelings systems d and e via p8. this information affects the feedback on comfort and discomfort. this feedback is assumed to be able to cause a change in emotional thinking without input. assume the result of the cognition by imitation at the reason system is advance for both self and the other and the robot is imitating the specified behaviour smoothly. if at this time the degree of discomfort determined by the feelings system is high, the consciousness system judges that advance is a discomfort. in response, the association system determines a new step and instructs the robot to retreat in the next behaviour. the timing of the above determination is described below. in the mirror image cognition experiments, the robot built for these experiments repeatedly imitated the motion of its image in the mirror. when the robot imitates the motion of its image in the mirror, and if the robot itself advances, the other or the mirror image always advances. by repeating this imitation of the advance behaviour, the robot eventually collides with the mirror. the collision causes an error detected by pid control and the consciousness module represents pain while the discomfort module e represents discomfort. the association system module f transmits representation of retreat to the reason unit. behaviour to avoid discomfort and invite comfort is implemented to continue imitation for self-cognition. b. neural network learning method the neural network learning method used in the present study is supervised learning with the back propagation method. specifically, we prepared bit strings for s, m’ and b as the learning inputs for the modnad of the reason system (figure 3). bit strings for s and b were prepared for the feelings systems. here are each bit strings. table 1 shows input in the imitation module. table 2 shows output in the imitation module. bit strings in table 2 are used in self and other cognition, e.g. if both self and other advance, bit strings in symbolic representation are 000. tables 3 and 4 show representation of pain and comfort modules. the imitation module a (figure 4) has 27 learning patterns. each of the feelings systems bthrough to e has 32 paterns and the association system has 72 patterns. in the connection from lower-layer to higherlayer in the feelings system, the trilaminar neural network is used and has 32 learning patterns. r and m at the reason and association system become the outputs when a value is entered into the neural network of the respective modnad (figure 3). r is the only output in the feelings systems. table 1. bit strings of input of the system condition bit strings both advances 000 one advance 001 both stop 010 one retreat 100 both retreats 111 table 2. bit strings of robotic behaviour condition bit strings advance 00 stop 01 retreat 11 table 3. bit strings of representation of pain condition bit strings no pain 000 a little pain 100 pain 011 lots of pain 111 table 4. bit strings of representation of comfort condition bit strings no comfortable 000 a little comfortable 001 comfortable 100 lots of comfortable 110 o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 96 the system learns by calculating the sum of mean square errors for the number of patterns using outputs r and m. the difference with the corresponding teacher signals then sequentially reduces the determined error. learning continues until the sum of mean square errors is reduced to below a certain value (0.01). c. result of learning and discussion figure 8 shows the learning of the imitation module, the association module, the pain and solitude modules. figure 9 shows the learning of the connections, and the discomfort and comfort modules. the x-axis of the graph is the learning number (order) and the y-axis is the mean square error (error). the graphs in figure 8 show that learning converges to about 0.01 within about 900 orders for the imitation module, the pain module, the solitude module, and the association module. the graphs in figure 9 show that learning converges to about 0.01 within about 400 orders for the comfort and discomfort module. but in the connections to comfort and discomfort learning converges to about 3,000 and 40,000 orders. learning in the modnad completed after a relatively small number of times because the processing efficiency of the modnad neural network is good. the results also show that each modnad has a function to imitate and cognise emotion. it further shows that the functions of consciousness and emotion as defined in this paper can be realised by combining the respective modnads. by structuring the consciousness system as described above, when mounted on a robot the system can imitate and cognise emotion and if discomfort is determined, select behavior to remove the discomfort. self-cognition can continue for the implementation of selfconsciousness. in the learning experiments using the consciousness system developed in this paper, the robot is considered capable of avoiding harmful obstacles if the robot is given an emotion function. the consciousness system will be mounted on a robot to verify that the robot actually evades obstacles using the emotion function and that the robot is capable of selfcognition. for robotic experiments, four objects to be imitated are prepared for. the following is four objects prepared: a robot taking action which figure 8. results of learning experiment ofimitation, association, solitude, and pain figure 9. results of learning experiment ofcomfort, discomfort, and the connections o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 97 is advance, stop or retreat at random; a robot possessing the consciousness system (a conscious robot); a robot controlled via cables from a conscious robot; and a mirror image of a conscious robot. a conscious robot will imitate these four objects and then it will be shown that the robot can have self-consciousness by comparing representations of self-condition to representations of other-condition in the system proposed in this paper. iv. conclusions this paper reported on research into functions that are intrinsic to humans such as mirror neuron and mimisis theory and defined a new consciousness. this paper also established a definition of the robot’s emotions based on human emotions. a consciousness system has been developed and successfully taught using artificial neural networks. a robot was asked to perform tasks using the consciousness system. learning converges to about 0.01 within 900 orders for imitation, pain, solitude and association modules. it converges to about 0.01 within 400 orders for the comfort and discomfort modules. it can be concluded that the learning efficiency of the modnad artificial neural network is good. these results provide a fundamental step for developing a robot having consciousness and feelings similar to humans. acknowledgement i would like to thank s.masri for his help in this work. references [1] k. company. (feb., 2013). available: http://www.kokoro-dreams.co.jp [2] h. miwa, et al., "effective emotional expressions with emotion expression humanoid robot we-4rii," in ieee/rsj intl. conf. on intelligent robots and systems, miyagi, japan, 2004, pp. 2203-2208. [3] v. gallese, et al., "action recognition in the premotor cortex," brain, vol. 119, pp. 593609 1996. [4] m. donald, origins of the modern mind. cambridge: harvard university press, 1991. [5] u. o. maryland. (20/12/2012). hearing and speech sciences. available: http://www.bsos.umd.edu/hesp/ index.htm [6] a. n. meltzoff and m. k. moore, "imitation of facial and manual gestures by human neonates," science, vol. 198, pp. 75-78, 1977. [7] k. ikegami, "effect of extrauterine and intrauterine experiences on tongue protruding imitation in premature infants and full-term neonates," annual report of grant-in-aide for scientific research, ministry of education, science, sports and culture: the emergence of human cognition and language, 3, pp 9-13, 1996. [8] a. r. damasio, the feeling of what happens: body and emotion in the making of consciousness. florida, u.s.a. : harcourt brace, orlando, 1999. [9] a. r. damasio, descartes’ error: emotion, reason and the human brain. quill, new york: g.p. putnam's sons, a divisions of the putnam berkley group, inc., 1994. [10] a. alsmith and f. de vignemont, "embodying the mind and representing the body," review of philosophy and psychology, vol. 3, pp. 1-13, 2012. [11] m. asada, et al., "cognitive developmental robotics: a survey," autonomous mental development, ieee transactions on, vol. 1, pp. 12-34, 2009. [12] l. w. barsalou, "grounded cognition," annu. rev. psychol., vol. 59, pp. 617-645, 2008. [13] r. d. beer, "the dynamics of active categorical perception in an evolved model agent," adaptive behavior, vol. 11, pp. 209243, december 1, 2003 2003. [14] r. blickhan, et al., "intelligence by mechanics," phil. trans. r. soc. a, vol. 365, pp. 199-220, 2007. [15] i. aleksander and b. dunmall, "axioms and tests for the presence of minimal consciousness in agents i: preamble," journal of consciousness studies, vol. 10, pp. 7-18, 2003. [16] i. aleksander, et al., "will and emotions: a machine model that shuns illusion," in proceedings of symposium on next generation approaches to machine consciousness: imagination, development, intersubjectivity, and embodiment, university of hertfordshire, hatfield, uk, 2005, pp. 110-116. [17] t. bosse, et al., "simulation and representation of body, emotion, and core consciousness," in proceedings of symposium on next generation approaches to machine consciousness: imagination, development, intersubjectivity, and embodiment, university of hertfordshire, hatfield, uk, 2005, pp. 95-103. [18] d. calverley, "towards a method for determining the legal status of a conscious o. shoubaky and t.m. sharari/ mechatronics, electrical power, and vehicular technology 05 (2014) 91-98 98 machine," in proceedings of symposium on next generation approaches to machine consciousness: imagination, development, intersubjectivity, and embodiment, university of hertfordshire, hatfield, uk, 2005, pp. 75-84. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 31-40, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.31-40 rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi midriem mirdanies, rizqi andry a, hendri maja saputra, aditya sukma nugraha, estiko rijanto, adi santoso pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia midr001@lipi.go.id diterima: 26 oktober 2010; direvisi: 7 april 2011; disetujui: 4 mei 2011; terbit online: 7 juli 2011. abstrak energi surya yang dihasilkan menggunakan panel pengumpul panas matahari agar lebih optimal diperlukan mekanisme pelacakan arah matahari. pada tulisan ini disajikan rancang bangun sistem kontrol pelacakan matahari dengan energi kecil beserta fasilitas telekontrolnya. metode yang digunakan untuk memacu pergerakan panel agar selalu menyesuaikan dengan arah matahari yaitu gabungan antara timer dan sensor cahaya. pada sistem kontrol ini, sinyal referensi diambil dari 2 buah sensor cahaya sedangkan umpan balik diambil dari sensor posisi, dan sensor suhu. telah dibuat program menggunakan bahasa pemrograman c dan diimplementasikan pada mikrokontroller atmega8535 yang digunakan sebagai otak dari sistem. fasilitas telekontrol untuk monitoring data via komputer menggunakan modul transceiver terkoneksi port rs-232. motor dc yang digunakan berdaya 0,74 watt dan dikopel ke reducer dengan rasio 1:7.300. telah dilakukan eksperimen karakteristik sensor cahaya dan simulasi pergerakan panel. dari eksperimen sensor cahaya diperoleh kesimpulan bahwa sinyal keluaran 0-4 volt, saat cerah 3,3-3,9 volt, saat mendung dan agak cerah 1,5-3,3 volt . dari hasil simulasi pergerakan panel, diketahui bahwa sistem kontrol pelacakan matahari yang dibuat dapat menggerakkan panel dan mengikuti arah pergerakan matahari. kata kunci: pelacakan matahari, sistem kontrol, mikrokontroler atmega8535, bahasa pemrograman c, telekontrol. abstract solar energy produced by concentrated solar heat collector panels requires tracking mechanisms for a more optimal direction. this paper presents the design and construction of a low energy solar tracking control system with telecontrol facilities. to accelerate the movement of the panel in always adjusting itself to the direction of the sun, a combination of the timer and light sensor was used. in this control system, the reference signal is taken from two pieces of light sensors while the feedback is taken from the positionand temperature sensors. the program has been developed using c language and was implemented on the microcontroller atmega8535 as the brain of the system. telecontrol facilities for monitoring the data to a computer uses transceiver modules via rs-232 connection. a dc motor having power capacity of 0.74 watts was used and was clutched with 1:7,300 gearbox ratio. experiments on light sensor characteristics and simulated movement of the panel were carried out. from the light sensor experiment it can be concluded that the sensor produces 0-4 volt output signal when bright 3.3-3.9 volts, when cloudy and 1.5-3.3 volts when sunny. from the simulation of panel movement, it is known that the solar tracking control system moves the panel and tracks the direction of the sun movement. keywords: solar tracking, control system, microcontroller atmega8535, c programming language, telecontrol. i. pendahuluan pemanfaatan energi surya sebagai sumber energi listrik dapat dihasilkan menggunakan panel fotovoltaik atau pemusatan sinar surya. saat ini penguapan fluida, yang juga dikenal sebagai pemusatan sinar surya atau termal surya lebih banyak menggunakan pemusatan sinar surya daripada panel fotovoltaik. energi surya yang dihasilkan menggunakan panel pengumpul panas matahari agar lebih optimal diperlukan mekanisme pelacakan arah matahari, supaya sinar matahari jatuh tegak lurus dibidang panel. mekanisme pelacakan arah metahari yang telah ada saat ini biasanya menggunakan metode timer atau data referensi dari sensor cahaya [1][2]. tujuan makalah ini adalah untuk menyajikan rancang bangun sistem kontrol pelacakan matahari dengan energi yang hemat beserta fasilitas telekontrolnya. metode yang digunakan untuk memacu pergerakan panel agar selalu menyesuaikan dengan arah matahari gabungan antara timer dan sensor cahaya. pada sistem kontrol ini, sinyal referensi diambil dari 2 buah sensor cahaya sedangkan umpan balik diambil http://dx.doi.org/10.14203/j.mev.2011.v2.31-40 rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi (midriem mirdanies, rizqi a.a., hendri m.s., aditya s.n., estiko r., adi s.) jmev 02 (2011) 31-40 32 gambar 1. desain sistem kontrol elektronik dan mekanisme tracking panel pengumpul panas matahari. dari sensor posisi dan sensor suhu. dalam penelitian ini telah dibuat sebuah desain produk sistem kontrol elektronik dan mekanisme tracking panel pengumpul panas matahari untuk menggerakkan panel solar collector dengan berat sekitar 679 kg dan luasan panel 24 m2 dengan kapasitas daya 1 kw. ii. metodologi penelitian penelitian ini terdiri dari beberapa tahap, yaitu studi literatur, perancangan desain sistem tracking, pembuatan mekanisme gerak, pembuatan sistem elektronika, pembuatan sistem monitoring, integrasi sistem tracking matahari, dan pengujian desain prototipe tracking matahari. pada pembuatan mekanisme gerak, digunakan motor dc sebagai actuator, speed reducer slewing dan gearbox untuk menyesuaikan kecepatan putar sistem dengan kecepatan matahari. pada pembuatan sistem elektronika, digunakan mikrokontroller atmega8535 sebagai otak dari sistem yang dihubungkan dengan modul dac, modul real time clock (rtc) dan drivermotor dc (h-bridge). sistem monitoring secara wireless via modul transceiver ys-c20ua [3] antara komputer dan ecu-nya melalui koneksi rs-232. desain sistem kontrol elektronik dan mekanisme tracking panel pengumpul panas matahari ditunjukkan pada gambar 1. sensor yang digunakan adalah sensor ldr (light dependent resistor) [4]. ldr adalah sebuah resistor yang nilai resistansinya menurun seiring meningkatnya intensitas cahaya yang mengenainya. gambar 2 menunjukkan perubahan nilai resistansi (r) sensor ldr terhadap intensitas cahaya (i) yang mengenainya. nilai intensitas cahaya dan resistansi berbanding terbalik secara eksponensial. untuk mendapatkan hasil nilai keluaran sensor yang lebih bagus maka ditambahkan rangkaian jembatan wheatstone serta rangkaian pengkondisi sinyal differential [5]. gambar 3 berikut ini merupakan skema dari rangkaian jembatan wheatstone serta rangkaian pengkondisi sinyal differential yang dirancang bangun. persamaan (1) berikut adalah persamaan dari jembatan wheatstone dan persamaan (2) gambar 2. karakteristik sensor ldr. gambar 3. skema rangkaian jembatan wheatstone. merupakan hasil keluaran dari rangkaian pengkondisi sinyal differential.       −∗ 31 3 2 r+r r r+r r v=v v v cdab (1) abo vr r =v ∗ − 4 7 (2) gambar 4 menunjukkan keseluruhan rangkaian elektronik pengontrol yang telah dibuat. cara kerja dari sistem kontrol ini adalah jika journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 31-40, 2011 p-issn 2087-3379 33 tidakmendung maka sistem akan memantau secara realtime arah dan intensitas cahaya matahari menggunakan sensor cahaya (ldr). sedangkan jika cuaca mendung maka sistem akan menggunakan metode timer saja, dengan menyesuaikan kecepatan putar panel dengan kecepatan matahari, dimana kecepatan matahari dapat diketahui dengan rumus berikut : ωmatahari=360°/24jam=0,0006944rpm untuk efisiensi maka digunakan motor dc (beserta gearbox) tipe: rs-360sh-10500 [6] dengan τ = 1,16nm, ω = 6,0955rpm dan pmotor = 0,74watt yang cukup untuk menggerakkan panel seberat 679 kg dengan center of gravity~0 setelah matahari terbenam di sore hari maka sistem akan menggerakkan panel kembali ke posisi awal matahari terbit. pergerakan ini dilakukan segera setelah matahari terbenam karena dengan kecepatan motor yang ada, dibutuhkan waktu yang lama untuk kembali ke posisi awal matahari. rangkaian sensor cahaya dibuat dengan 1 derajat kebebasan seperti yang ditunjukkan pada gambar 5. cara kerjanya yaitu dengan melihat perbedaan intensitas cahaya matahari yang diterima oleh kedua sensor cahaya tersebut. jika intensitas cahaya matahari yang diterima oleh sensor cahaya a < b maka sistem akan memerintahkan aktuator untuk bergerak kearah kanan hingga a = b, begitu juga sebaliknya, jika intensitas cahaya matahari yang diterima oleh sensor cahaya a dan b lebih kecil daripada intensitas cahaya minimum, maka data dari sensor cahaya ini tidak akan digunakan. penempatan sensor cahaya bersinggungan dengan plang pembatas bagian kiri dan kanan, hal ini dimaksudkan agar perubahan arah cahaya matahari yang kecil dapat langsung di deteksi oleh rangkaian ini. selain menggunakan rangkaian sensor cahaya, digunakan juga modul real time clock (rtc) [7] sebagai penghitung waktu seperti ditunjukkan pada gambar 6. rtc tersebut mempunyai menggunakan catu daya 5v dc atau dari baterai. pembacaan data dari rtc ini menggunakan i2c (inter-integrated circuit) atau biasa disebut ‘antarmuka dua kabel’. dalam kegiatan ini digunakan sensor suhu thermokouple tipe-k [8] yang dapat dilihat pada gambar 7 di bawah ini. sensor suhu ini berfungsi untuk mengukur suhu air yang mengalir pada pipa terpasang di panel solar collector. desain mekanisme penggerak dapat dilihat pada gambar 8. untuk menyesuaikan kecepatan putar dengan kecepatan matahari digunakan gambar 4. keseluruhan rangkaian elektronika. gambar 5. simulasi sensor cahaya. gambar 6. real time clock (rtc). gambar 7. sensor suhu thermokouple tipe-k. gambar 8. desain mekanisme penggerak. rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi (midriem mirdanies, rizqi a.a., hendri m.s., aditya s.n., estiko r., adi s.) jmev 02 (2011) 31-40 34 gambar 9. rangkaian h-bridge drivermotor dc yang dirancang bangun. speed reducer yang terdiri dari slewing [9] dan gearbox denganreduksi total = 1 : 7.300, aktuatornya menggunakan motor dc seperti yang telah dijelaskan sebelumnya. untuk menggerakkan motor dc digunakan rangkaian h-bridge seperti ditunjukkan pada gambar 9. rangkaian ini menggunakan empat mosfet irf540 yang dikendalikan oleh mikrokontroller melalui empat pin (x1-1, x1-2, x1-3, x1-4). empat buah optocoupler dipasang sebagai isolator antara mikrokontroller dan mosfet. untuk fasilitas sistem monitoring data digunakan modul transceiver ys-c20ua, dimana transmisi datanya menggunakan frekuensi 433 mhz dan dihubungkan ke komputer dan mikrokontrollernya melalui rs232. data yang dimonitor berupa posisi sudut panel, waktu sistem dan suhu pemanasan saat ini, dan dibaca melalui human machine interface (hmi) pada komputer. flowchart cara kerja sistem pada komputer dapat dilihat pada gambar 10. pada flowchart ini dilakukan inisialisasi variabel, serial port, dan timer. kemudian dilakukan pembacaan nilai sudut, cahaya, suhu, dan waktu dari modul transceiver. nilai pada sistem yang dapat diatur melalui komputer adalah nilai waktu (tanggal, jam, menit, detik). flowchart cara kerja sistem pada mikrokontroller atmega8535 dapat dilihat pada gambar 11. ketika sistem pertama kali bekerja, sistem akan menyesuaikan posisi panel dengan posisi matahari. selanjutnya sistem akan menyesuaikan pergerakan panel secara terus menerus berdasarkan data dari sensor cahaya atau dari timer. ketika komputer mengirimkan data gambar 10. flowchart cara kerja sistem pada komputer. perubahan waktu ke dalam sistem melalui modul transceiver, maka sistem akan mengkoreksi posisi sudut panel sesuai data yang dikirimkan oleh komputer. pada komputer start deklarasi : variabel serial port timer memetakan nilai sudut ke gambar baca data yang diterima (sudut, cahaya, suhu, dan waktu) dari modul transceiver tampilkan ke layar monitor / gui (data sudut, cahaya, suhu, dan waktu) ulangi input perubahan waktu (tgl, jam, menit dan detik) kirim data perubahan waktu melalui modul transceiver jika ada perubahan data waktu jika ada perubahan data waktu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 31-40, 2011 p-issn 2087-3379 35 start deklarasi : usart adc dac rtc (timer) ulangi baca data timer melalui adc dari modul rtc kirim data sudut, cahaya, suhu & waktu melalui modul transceiver pada mikrokontroller atmega8535 baca data waktu yang diterima (tgl, jam, menit dan detik) dari modul transceiver ubah waktu sistem ada data perubahan waktu yang dikirim melalui modul transceiver atau sistem baru mulai transmisi data sesuaikan posisi panel saat ini dgn waktu sistem (berdasarkan timer & map) menggerakkan panel setiap beberapa waktu dgn kec mengikuti kec matahari (dipicu oleh timer) menggerakkan panel dgn kec > kec matahari kearah kanan hingga data sensor cahaya kiri = kanan data dari kedua sensor cahaya matahari > nilai minimal ya data sensor cahaya kanan > kiri tidak menggerakkan panel dgn kec > kec matahari kearah kiri hingga data sensor cahaya kiri = kanan yatidak baca data dari sensor cahaya, sudut, arus & suhu melalui adc apakah saat ini antara jam 7 pagi s/d jam 5 sore yatidak sudut = 10 derajat (sesuaikan dengan map) ya tidak menggerakkan panel dgn kec 100% ke arah timur ulangi jika ada perubahan data waktu jika ada perubahan data waktu tidak ya gambar 11. flowchart cara kerja sistem pada mikrokontroller atmega8535. rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi (midriem mirdanies, rizqi a.a., hendri m.s., aditya s.n., estiko r., adi s.) jmev 02 (2011) 31-40 36 pembuatan hmi dilakukan menggunakan bahasa pemrograman visual basic 2008 (.net). tampilan hmi-nya adalah seperti ditunjukkan gambar 12. pada group data, textbox tanggal dan waktu merupakan tanggal dan waktu yang dibaca dari sistem (pada modul rtc), textbox sudut menunjukkan sudut panel saat ini, dan textbox suhu menunjukkan suhu pemanasan saat ini. sedangkan pada group set rtc, textbox tanggal, bulan, tahun, jam, menit dan detik diisi jika ingin mengubah tanggal pada sistem berdasarkan tanggal yang diisi atau jika ingin mengubah tanggal pada sistem berdasarkan tanggal komputer maka dapat dilakukan dengan menekan tombol automatic. tombol connect digunakan untuk koneksi dengan sistem dan tombol disconnect digunakan untuk memutuskan koneksi dengan sistem. untuk mengetahui berfungsi atau tidaknya sistem kontrol mekanisme solar tracker saat dipasang pada panel yang sebenarnya maka dibuat simulasi mekanisme gerak solar tracker dahulu dimana pembuatannya disesuaikan dengan desain panel concentrator yang sebenarnya dapat ditunjukkan pada gambar 13. dudukan masing-masing komponennya disesuaikan dengan desain kaki dari panel concentrator, dan pada simulasi ini juga dibuat simulasi beban dimana bebannya dapat ditambah sesuai keinginan untuk mengetahui kemampuan sistem. iii. hasil danpembahasan gambar 14 merupakan simulasi mekanisme penggerak yang telah dibuat berdasarkan desain pada gambar 13. pada simulasi mekanisme penggerak yang telah dibuat, telah dilakukan ujicoba simulasi beban dan dudukan alat pada kaki panel. dari hasil simulasi yang dilakukan tersebut diketahui bahwa alat-alat mekanik yang digunakan dapat dipasang pada panel yang sesungguhnya dengan desain dudukan ini, serta dari simulasi ini diketahui pula bahwa motor dc yang digunakan dapat menggerakkan beban dengan baik. di bawah ini merupakan data yang diperoleh dari percobaan dengan menggunakan sun simulator tipe oriel corporation model 81193 [10] dan sensor ldr yang dapat ditunjukkan pada tabel 1 dan tabel 2 serta hasil grafik pada gambar 15. percobaan ini dilakukan dengan tujuan untuk mengetahui sensitifitas dari sensor ldr dengan cara mengatur daya pada sun simulator sehingga dihasilkan nilai hambatan yang bervariasi pada sensor ldr. disana terlihat bahwa perubahan nilai hambatan sensor ldr gambar 12. tampilan hmi. gambar 13. desain simulasi mekanisme penggerak. gambar 14. simulasi mekanisme penggerak yang telah dibuat. berbanding terbalik dengan nilai daya yang diset pada sun simulator, semakin besar nilai daya yang diset pada sun simulator maka semakin kecil nilai hambatan pada sensor ldr. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 31-40, 2011 p-issn 2087-3379 37 tabel 1. percobaan sun simulator center. no daya simulator (watt) pyranometer (w/m2) nilai ldr (ω) 1 0 0 2 200 35 86,2 3 400 100 52,6 4 600 195 41 5 800 290 35,1 6 1.000 395 31,2 7 800 290 35,3 8 600 190 41,4 9 400 100 53,8 19 200 35 86,3 11 0 0 tabel 2. percobaan sun simulator geser 1cm. no daya simulator (watt) pyranometer (w/m2) nilai ldr (ω) 12 0 0 13 200 35 85,7 14 400 105 53 15 600 205 41 16 800 305 35,1 17 1000 410 31,7 18 800 295 35,7 19 600 195 41,8 20 400 105 53,9 21 200 35 86,7 22 0 0 gambar 15. grafik percobaan memakai sun simulator. untuk mengetahui karakteristik rangkaian jembatan wheatstone penguat differensial yang telah dirancang bangun di gambar 3, telah dilakukan pengujian dengan cara memberikan nilai tegangan beragam melalui pengaturan dengan variabel resistor rv (lihat gambar 3) kemudian dicatat hasil keluarannya apakah sesuai dengan hasil yang diinginkan. data yang didapat pada percobaan ini bisa dilihat pada tabel 3 dan gambar 16. dari data pada tabel 3 serta gambar 16 terlihat bahwa ketika nilai resistansi rv dinaikkan maka tegangan yang dihasilkan pada vab (jembatan wheatstone) akan mengalami peningkatan, kemudian ketika nilai resistansi rv mencapai 200 ohm nilai yang dihasilkan vab menjadi nol. hal ini karena jembatan wheatstone mengalami kesetimbangan dimana formulasi setimbang jembatan wheatstone adalah rv*r6=r4*r5, lihat gambar 3. sedangkan nilai tabel 3. pengukuran dengan rv. no rv (ω) vab (v) vout (v) 1 10 -1,844 3,694 2 20 -1,73 3,464 3 40 -1,503 3,009 4 60 -1,291 2,583 5 80 -1,081 2,163 6 100 -0,884 1,767 7 120 -0,692 1,382 8 140 -0,506 1,009 9 160 -0,333 0,66 10 180 -0,156 0,306 11 200 -0,008 0 12 500 1,905 -3,83 13 1000 3,76 -7,56 14 1500 4,86 -8,41 30 40 50 60 70 80 90 0 100 200 300 400 n ila i l d r (o hm ) pyranometer (w/m2) geser 1cm center rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi (midriem mirdanies, rizqi a.a., hendri m.s., aditya s.n., estiko r., adi s.) jmev 02 (2011) 31-40 38 gambar 16. grafik pengukuran vout terhadap rv. gambar 17. grafik hasil pengukuran cahaya matahari menggunakan modul sensor cahaya yang telah dibuat dengan tinggi sensor dari ujung pipa 3cm. pada kolom vout merupakan hasil dari penguatan tegangan vab dengan gain = -2. telah dilakukan pengukuran cahaya matahari menggunakan modul sensor cahaya yang telah dibuat. pengukuran ini dilakukan pada lantai atas gedung 20 lipi bandung. posisi gedung ini berada pada garis lintang : 6°52’52” s dan garis bujur : 107°36’39” t. perubahan cahaya matahari yang diterima oleh modul sensor cahaya yang telah dibuat dapat dilihat pada tabel 4 dan gambar 17. dari grafik hasil pengukuran di gambar 17 didapat dari pengukuran mulai pukul 09.00 sampai pukul 15:00 dalam 3 hari. pada grafik terlihat bahwa mulai pukul 9-11 pagi nilai vout akan mulai meningkat, nilai tertinggi vout terlihat antara pukul 11-12 karena saat itu matahari tepat di atas kepala, kemudian vout tabel 4. pengukuran intensitas matahari secara langsung. no jam nilai vout (v) 28/12/10 29/12/10 06/01/11 1 9:15 2,958 2,823 2,564 2 10:15 3,136 3,092 3,105 3 11:15 3,18 2,13 3,274 4 12:15 3,176 2,282 3,172 5 13:15 3,109 1,758 1,477 6 14:15 2,674 2,731 2,622 7 15:15 2,403 2,387 1,857 akan mulai cenderung menurun sampai pukul 15:00. pada grafik di atas juga terlihat ketidakteraturan pola turun naik hal ini karena kondisi cuaca yang tidak menentu, kadang cerah kemudian mendung gelap. -10 -8 -6 -4 -2 0 2 4 6 0 500 1000 1500 2000 n ila i v ou t ( v ) nilai rv (ω) 0 0.5 1 1.5 2 2.5 3 3.5 8 10 12 14 16 n ila i v ou t( v ) waktu (jam) 28/12/10 29/12/10 06/01/11 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 31-40, 2011 p-issn 2087-3379 39 gambar 18. grafik pengambilan data sensor kena sinar matahari tabel 5. pengambilan data sensor kena sinar matahari. no bagian kena matahari (%) nilai vout (v) data grafik 1 data grafik 2 data grafik 3 1 0 3,379 3,347 3,376 2 25 3,51 3,526 3,59 3 50 3,653 3,695 3,78 4 75 3,781 3,818 3,827 5 100 3,855 3,87 3,877 6 0 3,357 3,361 3,352 data pada tabel 5 didapat dengan cara mengukur intensitas cahaya matahari (pada saat cerah) yang mengenai sensor ldr yang telah diberi selubung pipa, dimana sensor ldr dibenamkan sedalam 3 cm dari permukaan pipa. pipa digerakkan sehingga sensor ldr yang didalamnya terkena cahaya matahari dengan prosentase yang telah ditentukan seperti yang tertera pada tabel 5. percobaan ini dilakukan sebanyak tiga kali dan nilai yang dicatat adalah nilai tegangan yang dihasilkan oleh sensor ldr yang sebelumnya dilewatkan melalui rangkaian jembatan wheatstone dan dikuatkan sebesar 2 kali oleh penguat differensial. pada grafik gambar 18 terlihat bahwa semakin luas penampang ldr yang terkena cahaya, maka semakin tinggi nilai yang dihasilkan iv. kesimpulan dan saran berdasarkan hasil simulasi dan analisisdalam penelitian ini, dapat diambil kesimpulan sebagai berikut: 1. sistem kontrol mekanisme pelacakan matahari yang dibuat dapat menggerakkan panel hanya dengan menggunakan motor dc berdaya rendah sehingga energi yang terbuang untuk mensuplai motor dc menjadi kecil. 2. modul sensor cahaya dapat digunakan sebagai referensi untuk menyesuaikan arah panel dengan arah matahari, sedangkan kelemahan menggunakan modul ini saat mendung (intensitas cahaya matahari lemah) dapat teratasi dengan menggunakan metoda timer. 3. sistem monitoring menggunakan wireless, memudahkan pemantauan panel concentrator untuk mengetahui waktu sistem, suhu pemanasan, maupun sudut panel melalui hmi pada komputer. 4. data percobaan sensor cahaya diperoleh data sebagai berikut: sinyal keluaran berkisar 0-4 volt, saat cerah 3,3-3,9 volt, saat mendung dan agak cerah 1,5-3,3 volt. 5. sensor suhu jenis thermokouple digunakan untuk mengukur temperatur air pada pipa yang terpasang di panel solar tracker. ucapan terimakasih penulis mengucapkan terimakasih kepada kepala bidang mekatronik serta teman-teman di bidang mekatronik yang telah membantu dalam penelitian ini, pusat penelitian tenaga listrik dan mekatronik lipi atas kesempatan yang diberikan, serta semua pihak yang tidak dapat disebutkan satu persatu, yang telah membantu penulisan karya tulis ilmiah ini daftar pustaka [1] johnson, george, listrik matahari, national geographic indonesia, 2009. 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 0 20 40 60 80 100 120 n ila i v ou t ( v ) prosentase luas penampang kena sinar (%) grafik1 grafik2 grafik3 rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi (midriem mirdanies, rizqi a.a., hendri m.s., aditya s.n., estiko r., adi s.) jmev 02 (2011) 31-40 40 [2] lee, chia-yen, et al. 2009. sun tracking systems: a review, sensors, 9, 38753890. 2009 [3] rf transceiver modules. (june 2009) shenzhen yishi electronic technology development co., ltd. guangdong, china. [online]. available: http://www.yishi.net.cn/rf/productshow.as p?id=99 [4] light dependent resistors datasheet, rs component, uk,maret 1997. [5] mancini , ron , op amps for everyone, texas instruments, agustus 2002. [6] rs-360sh. (august 2010) mabuchi motor. chiba, japan. [online]. available: http://www.mabuchi-motor.co.jp/cgibin/catalog/e_catalog.cgi?cat_id=rs_360 sh [7] i2c peripheral. (2005). innovative electronics. surabaya, indonesia. [online]. available: http://www.innovativeelectronics.com/inno vative_electronics/download_files/manual/ manualdt-io serial rtc & eeprom.pdf [8] temperatures.com, inc., (2010), thermocouples (tcs) [online]. available: http://www.temperatures.com/sensors/csen sors/thermocouples-tcs/ [9] slewing drives. (2010) jiangyin huafang new energy hi-tech equipment co., ltd. jiangyin city, china. [online]. available: http://www.h-fang.com.cn/ [10] manual book sun simulator oriel corporation model 81193 ser.no 134, usa, juni 1994. maximum power point tracking of photovoltaic system for traffic light application mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.57-64 maximum power point tracking of photovoltaic system for traffic light application riza muhida a,*, nor hilmi mohamad b, ari legowo c, rudi irawan a, winda astuti b asurya university, sure center building, jl. scientia boulevard, blok u/7, summarecon gading serpong, tangerang, indonesia bdepartment of mechatronics engineering, international islamic university malaysia gombak, kuala lumpur 53100, malaysia cdepartment of mechanical engineering, international islamic university malaysia gombak, kuala lumpur 53100, malaysia received 1 april 2013; received in revised form 15 may 2013; accepted 15 may 2013 published online 30 july 2013 abstract photovoltaic traffic light system is a significant application of renewable energy source. the development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. since photovoltaic (pv) modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (mppt) method is applied to the traffic light system. mppt is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. mppt is actually a dc-dc converter that can step up or down voltage in order to achieve the maximum power using pulse width modulation (pwm) control. from experiment, we obtained the voltage of operation using mppt is at 16.454 v, this value has error of 2.6%, if we compared with maximum power point voltage of pv module that is 16.9 v. based on this result it can be said that this mppt control works successfully to deliver the power from pv module to battery maximally. keywords: photovoltaic, maximum power point tracking, traffic light, voltage converter, battery charging. i. introduction photovoltaic pedestrian light system is a significant application of photovoltaic source. the development of the system is an alternative for local authority to reduce expenditure for paying fees to power supplier which the power comes from electric generator. many research institutions around the world have developed these systems as contribution to society and thus will accelerate initiatives to adopt solar energy as an alternative source for power supply. since the photovoltaic pedestrian light system is expensive to build, it should be operated at its maximum output power level, using a control technique in order to the system can work efficiently [1-12]. the main objective in this project is to design a traffic light system powered by photovoltaic and to obtain the maximum power from pv energy output to charge the battery and to operate the system. ii. traffic light system powered by photovoltaic a. diagram of overall system figure 1 below shows the general layout of the electrical system. this system consists of pv module, mppt, battery, traffic light lamp, push button switch for pedestrian, relay unit, voltage regulator and peripheral interface controller (pic) microcontroller. traffic light lamp in this experiment uses light-emitting diode (led) type, the led-based lamps consist of an array of led elements, arranged in various patterns. when viewed from a distance, the array appears as a continuous light source. led-based lamps have numerous advantages over incandescent lamps; among them are: much greater energy efficiency, much longer lifetime between replacements, brighter illumination with better contrast even in direct sunlight, the ability to display multiple colors and patterns from the same lamp. individual led elements can be enabled or disabled, and different color leds can be mixed * corresponding author. tel: +62-21-70200270 e-mail: muhida@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.57-64 r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 58 in the same lamp, much faster switching. figure 2 shows led traffic light that is used in this experiment. the solar module selected for this prototype is polycrystalline silicon type. table 1 shows characteristic of this pv module. to store the energy we use a battery. battery is a device that converts chemical energy contained in active materials directly into electrical energy by means of an electrochemical reaction. batteries used in pv lighting system must be rechargeable. battery characteristic used in this experiment is shown in table 2 and figure 3. the optimal type of battery for pv traffic light is a deep-cycle (or deep discharge) battery which most of its energy can be repeatedly drained and recharged. the maximum depth of discharge for low-maintenance (sealed) batteries is 30%. the maximum depth of discharge is a measure (in percentage) of the amount of energy that can be drained from the battery during the cycle, without damaging the battery. batteries should generally be located in a weather resistant, non-metallic enclosure in order to prevent corrosion. the main controller used to control the sequence of traffic light and reading battery level as well is pic microcontroller 16f877a. in another word, we can say that it is the brain of the system. in order to give instruction to this kind of microcontroller, we need to do programming according to the sequence needed. to achieve this, we need its software (pic c compiler) and pic programmer kit. in this pic, there is also a module for displaying characters in liquid-crystal display (lcd) and reading analog input. we select pic 16f877a as main controller in here because this microcontroller has complete peripheral and more reliable, if compared with other microcontroller [9]. basic wiring of pic microcontroller is shown in figure 4. because figure 1. schematic diagram of traffic light system powered by photovoltaic table 1. characteristics of pv module item specification manufacturer kyocera (japan) model kc120-1 standard irradiance / cell temperature 1000 w/m2 (am 1.5) 25 °c maximum power 120 w voltage at maximum power 16.9 v current at maximum power 7.0 a open circuit voltage 21.5 v short circuit current 7.45 a figure 2. led traffic light (left) and led pedestrian light (right) are under testing in lab table 2. characteristics of battery item specification manufacturer msb model msl 12-40 voltage 12 v capacity 40 ah dimensions 195 × 165 × 170 mm weight 10.0 kg figure 4. basic connection of pic microcontroller figure 3. sealed lead acid battery r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 59 pic microcontroller (or small scale circuit) needs only small amount of voltage, a voltage regulator is required to regulate the voltage coming from pv cell. in this system, we have chosen lm7805 which provides 5v supply. in order to have further stabilized voltage, the capacitors are required to filter high frequency (as shown in the following voltage regulator schematic diagram) because digital devices are very sensitive with small change of voltage. basic wiring of the regulator for the pic microcontroller shown in figure 5. to control voltage of traffic light lamp using pic microcontroller we use a relay. it is very crucial to isolate one circuit electrically from another, while still allowing the first circuit to control the second. one simple method of providing electrical isolation between two circuits is to place a relay between them, as shown in the circuit diagram in figure 6 below. a relay consists of a coil which may be energized by the low-voltage circuit and one or more sets of switch contacts which may be connected to the high-voltage circuit. in this project, single pole double throw (spdt) relays with 5v-rating have been chosen because the relay voltage is supplied by output of pic microcontroller. even though every output pin already produces 5v (for high state), it is still insufficient to energize the relay due to the low current output. therefore, transistors are required to amplify the current for energizing the relays. b. control mechanism of traffic light flow chart of control mechanism for traffic light system is shown in figure 7. where we set an instruction command for pic microcontroller 16f877a, in pic has some i/o pin in port d, we can control the traffic light lamp to be on or off use a set a sequence command to make port d on or off, and based on this on or off sequence we can make the lamp (green, yellow or red) on or off too. c. pv-battery charging this design implements a charger for a leadacid battery as a sub-function in a microcontroller whose main function can be any more complex task. furthermore, pic microcontroller gets its power from the same battery. the charging process is gradual and uses so little processor time and therefore it does not disturb the pic microcontroller primary task-controlling sequence of lighting. diagrams of connection and charging between pv and battery are shown in figure 8 and figure 9. in the case, when the battery is being charged, power switch must be on until the voltage reaches the upper limit of charging. in the second case, when the battery is being discharging, the power switch must be off until it reaches the lower limit of discharging. the lowest limit can be configured in pic microcontroller and the state of charge can be monitored by user using lcd. figure 5.basic connection of pic microcontroller. figure 6. basic connection of pic microcontroller, relay and lamp figure 7. control mechanism of traffic light system figure 8. pv-battery charging diagram r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 60 charging control mechanism is shown in figure 10. where if voltage of the battery over 14.5 v, then switch of relay will be off. and if voltage of the battery below 14.5 v this switch will be on. iii. maximum power point tracking a. theoretical approach electrical characteristic of voltage and current of solar module can be represented by the curve experimentally and can be mathematically expressed using curve identification. 𝑖𝑖(𝑣𝑣) = 𝐼𝐼𝑠𝑠𝑠𝑠 − 𝐼𝐼𝑑𝑑 �exp � 𝑒𝑒𝑒𝑒 𝑘𝑘𝑘𝑘 �− 1� (1) where i(v) is current density flowing into load (a/m2), isc is short-circuit current density (a/m2), id is dark (saturation) current density (a/m2), v is voltage across cell (v), k is boltzmann’s constant (1.38 x 10-23 j/k), t is absolute temperature (k), and e is single electron charge (1.6 × 10-19 c). the maximum voltage across pv cell is achieved under open-circuit condition, or i(v)=0, � 0 = 𝐼𝐼𝑠𝑠𝑠𝑠 − 𝐼𝐼𝑑𝑑 �exp � 𝑒𝑒𝑒𝑒𝑜𝑜𝑠𝑠 𝑘𝑘𝑘𝑘 �− 1� 𝑒𝑒𝑜𝑜𝑠𝑠 = � 𝑘𝑘𝑘𝑘 𝑒𝑒 � ln �𝐼𝐼𝑠𝑠𝑠𝑠 𝐼𝐼𝑑𝑑 + 1� � (2) power obtained from pv cell is: � 𝑝𝑝 = 𝑖𝑖𝑣𝑣 𝑝𝑝(𝑣𝑣) = �𝐼𝐼𝑠𝑠𝑠𝑠 − 𝐼𝐼𝑑𝑑 �exp � 𝑒𝑒𝑣𝑣 𝑘𝑘𝑘𝑘 � − 1�� [𝑣𝑣] � (3) the maximum power point is obtained by applying the condition dp/dt = 0.                              −      −+            −=             −      −+                  −=             −=             −=            −=             −      −= += 1 e exp e exp e 1 e exp e exp e e exp e e exp e exp 1 e exp )( dsc d dscd d dd dsc kt v ii kt v kt vi kt v ii kt v kt iv dv dp kt v kt i kt v dv d i kt v i dv d kt v ii dv d dv di vi dv di v dv dp (4) 0 = −�𝐼𝐼𝑑𝑑𝑒𝑒𝑣𝑣 𝑘𝑘𝑘𝑘 � exp �𝑒𝑒𝑣𝑣 𝑘𝑘𝑘𝑘 � + 𝐼𝐼𝑠𝑠𝑠𝑠 − 𝐼𝐼𝑑𝑑 �exp� 𝑒𝑒𝑣𝑣 𝑘𝑘𝑘𝑘 � − 1� (5) the maximum power is achieved at the voltage that satisfies 𝑑𝑑𝑝𝑝/𝑑𝑑𝑣𝑣 = 0 as shown in figure 11. figure 9. pv-battery charging circuit figure 10. pv-battery charging control mechanism r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 61 in a dc-dc converter, we can set voltage as a function of duty factor (d), as formulated below: 𝑒𝑒𝑜𝑜 = 𝑒𝑒𝑖𝑖 𝐷𝐷 (6) where 𝑒𝑒𝑖𝑖 is voltage input of dc-dc converter, 𝑒𝑒𝑜𝑜 is voltage output of dc-dc converter, and d is duty cycle of pulse width modulation (pwm) in switching mosfet. therefore, changing of duty cycle will increase or decrease the output voltage. b. dc-dc converter stepping-down or stepping up the voltage needs adjustment of pwm connected to mosfet as switch. in this case, according to investigation of electrical characteristics of current-voltage, we have decided to use stepdown or buck converter to implement dc-dc conversion. actually, most of mppts usually use buck converter. diagram of dc-dc converter used in this experiment is shown in figure 12. switching dc-dc converter is more efficient at very high frequency. therefore, using pic, we can generate high frequency pwm. a very high frequency signal is generated, with amount of 2.4 khz through pin c2. for duty cycle adjustment, we need to know the maximum power obtained at particular voltage. this voltage can be either measured by investigating electrical characteristic or referring data sheet or specification provided by manufacturer. according to the specification provided by the manufacturer (kindly refer to table 1), the maximum power is obtained at 16.9 v at 1000 w/m2 irradiance with 25°c temperature. because the load of the system is almost constant, we can only fix the duty cycle according to the input and output voltage in which depend on the load. we have output voltage from pv module at certain load, and then the maximum power point voltage has been obtained. then, duty cycle is the ratio of maximum power point voltage (𝑒𝑒𝑀𝑀𝑀𝑀𝑀𝑀 ) to output voltage from pv module at certain load. mathematically, it can be expressed as follows: 𝐷𝐷 = 𝑒𝑒𝑀𝑀𝑀𝑀𝑀𝑀 𝑒𝑒𝑜𝑜𝑜𝑜𝑜𝑜𝑝𝑝𝑜𝑜𝑜𝑜 (7) for instance, the output voltage from pv module is 18 v and maximum power point voltage is 16 v. then, duty cycle = 16/18 = 0.89. in the algorithm, the signal is generated using the following algorithm: setup_ccp1(ccp_pwm);//pin c2 setup_timer_2(t2_div_by_16,127,1); // 2.4 khz signal set_pwm1_duty(113);// 0.89 duty cycle according the algorithm above, 113 is obtained based on duty cycle value obtained previously, 113/127 ≈ 16/18. figure 11. characteristic of power-voltage of pv panel figure 12. a dc-dc converter circuit for mppt control r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 62 iv. result and discussion a. implementation circuit figure 13 shows circuit of this experiment board consits of dc-dc converter, control circuit and relay. figure 14 shows a traffic light lamp with a mounting pv modul that is used in this experiment. b. measurement technique after completing traffic light module installation and its control, performance analysis for power consumption should be done. this involves measurement of voltage and current for both pv-battery and battery-load. for voltage and current analysis, it was suggested to take the reading for every 10 minutes for graph plotting purpose. there were two ways of measurement of these parameters; using data acquisition or multimeters. for voltage measurement, labview 7.0 is used with several hardwares: • ni-pci-6221 is installed inside the host computer through pci slot with provided driver software. • ni-scc-68 is to be connected with to-bemeasured source (attenuated source) or to be connected with direct source in between 10v and +10v. • nc-scc-ai01 for voltage attenuation due to the limited range of ni-scc-68. the gain for this attenuator is 0.2. therefore, 12v will display 12v x 0.2 = 2.4v. for current measurement, there must have been a current to voltage converter with a determined gain prior to attenuation using nc-scc-ai01. however, the current-to-voltage package was unavailable. figure 14. traffic light lamp and pv module figure 15. measurement components using ni scc-68 figure 13. experimental board r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 63 designing the new one seemed to be difficult and required a lot of time. hence, the manual way was suggested; using two multimeters with ammeter configuration. then, the data containing four parameters were taken from the morning until evening and tabulated. after finishing tabulation, the data were plotted with four parameters versus time. figure 15 shows some components that are used to measure the performance of this system. c. battery charging performance figure 16 shows performance graph of battery charging system. based on figure 16 and figure 10, we can see that this charging system work well. where in the beginning of this experiment the battery is in full condition (voltage of battery more than 14.5 v), this condition makes relay circuit cut off the current. when the voltage of battery below 14.5 v the relay switch will on and charging battery occurs, at this time we can see the current 3.5 a delivered from pv modul to battery. d. mppt performance the experimental tests have been done for the mppt. figure 17 shows output of generated pulse from microcontroller as a feed pulse for mosfet. this generated pulse can be programmed as we desired as duty cycle of dcdc converter. for pwm control, the duty cycle is 0.866 with 2.4 khz frequency. from theoretical analysis, we can obtain the expected output voltage, 0.866 × 19 v = 16.454 v at maximum power. figure 18 shows the output voltage of the dc-dc converter after being filtered, where we can keep output of the dc-dc converter oround 16.5 v. this voltage is a swing point of maximum power point of pv module. this method is known as mppt technique uses constant voltage control [13]. this value had has error of 2.6%, if we compared with maximum power point voltage of pv module in table 1 that is 16.9 v. e. test of the overall system we have tested overall system of traffic light system powered by photovoltaic and mppt for one day. based on the test, the traffic light lamp, battery charging system and mppt work well as we designed. v. conclusions in this paper we have presented the design and experimental of traffic light system powered by photovoltaic and mppt. based on experiment we can conclude that the mppt, battery charging and lamp controller worked as we desired in design process. the output voltage from dc-dc converter circuit from measurement showed value around 16.5 v, where this voltage measurement closes to mpp voltage of pv module data sheet. this shows that mpp control worked well to deliver a maximum power from pv module to battery. figure 16. performance of battery charging system figure 17. generated pulse from microcontroller as a feed pulse for mosfet figure 18. the output voltage output of dc-dc converter r. muhida et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 57-64 64 references [1] s.-h. ko and r.-m. chao, "photovoltaic dynamic mppt on a moving vehicle," solar energy, vol. 86, pp. 1750-1760, 2012. [2] f. chekired, et al., "implementation of a mppt fuzzy controller for photovoltaic systems on fpga circuit," energy procedia, vol. 6, pp. 541-549, 2011. [3] syafaruddin, et al., "performance enhancement of photovoltaic array through string and central based mppt system under non-uniform irradiance conditions," energy conversion and management, vol. 62, pp. 131-140, 2012. [4] t. bennett, et al., "photovoltaic model and converter topology considerations for mppt purposes," solar energy, vol. 86, pp. 2029-2040, 2012. [5] p. e. kakosimos and a. g. kladas, "implementation of photovoltaic array mppt through fixed step predictive control technique," renewable energy, vol. 36, pp. 2508-2514, 2011. [6] n. a. ahmed, et al., "development of an efficient utility interactive combined wind/photovoltaic/fuel cell power system with mppt and dc bus voltage regulation," electric power systems research, vol. 81, pp. 1096-1106, 2011. [7] r. muhida, et al., "a maximum power point tracking for photovoltaic-spe system using a maximum current controller," solar energy materials & solar cells, vol. 75, pp. 697–706, 2003. [8] n. a. ahmed and m. miyatake, "a novel maximum power point tracking for photovoltaic applications under partially shaded insolation conditions," electric power systems research, vol. 78, pp. 777-784, 2008. [9] s. roy chowdhury and h. saha, "maximum power point tracking of partially shaded solar photovoltaic arrays," solar energy materials and solar cells, vol. 94, pp. 1441-1447, 2010. [10] k. m. tsang and w. l. chan, "model based rapid maximum power point tracking for photovoltaic systems," energy conversion and management, vol. 70, pp. 83-89, 2013. [11] y.-c. wu, et al., "maximum power point tracking on stand-alone solar power system: three-point-weighting method incorporating mid-point tracking," international journal of electrical power & energy systems, vol. 52, pp. 14-24, 2013. [12] m. m. algazar, et al., "maximum power point tracking using fuzzy logic control," international journal of electrical power & energy systems, vol. 39, pp. 21-28, 2012. [13] m. park, et al., "a novel mppt control method using optimal voltage of pv with secondary phase-shift pwm control dcac converter," in proceeding of international conference on electric power engineering, budapest 99, aug. 29 1999-sept. 2 1999, p. 269. diagram of overall system control mechanism of traffic light pv-battery charging theoretical approach dc-dc converter microsoft word vol04_no1 add pages _rev_aam_ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 04, issue 1, july 2013 aim and scope mechatronics, electrical power, and vehicular technology (mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on: mechatronics: including control system, robotic application, and cnc machining development. electrical power: including power generation, transmission system, new and renewable energy, tubine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev journal vision is to become international journal with high scientific contribution for global community. mev journal mission is presenting important results of work, whether in the form of research, development, application, or design. indexing indexed in google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), and indonesian publication index (ipi). editor-in-chief dr.eng. estiko rijanto mechatronics division, research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 5528,1indonesia jamasri_tmugm@yahoo.com prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h1034, hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia za@dynamic.pauir.itb.ac.id prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering,universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id advisory editor ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 04, issue 1, july 2013 imprint journal of mechatronics, electrical power, and vehicular technology (mev) is published and imprinted by research center for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). mev journal is managed to be issued twice in every volume. for every edition, the online edition is published earlier than the print edition. issn print edition: 2087-3379 issn electronics edition: 2088-6985 electronics edition is available at www.mevjournal.com accreditation mev journal has been certificated as national scientific journal by indonesian institute of sciences (lipi) by 24 april 2012. accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 valid thru: 24 april 2015 postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 managing editors aam muharam, m.t. electrical engineering aam.muharam@yahoo.com dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com section editors ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com arini wresta, m.eng. chemical engineering awresta@gmail.com yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id dian andriani, m.eng. bioenergy dea1401@yahoo.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com layout editors rakhmad i pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com hendri m saputra, m.t. robot and mechatronic hendri_maja@yahoo.co.id arief a firdaus, s.i.kom. communication science rif212@yahoo.com proofreaders naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com achmad praptijanto, m.eng. mechanical engineering cak.yanto@gmail.com subscription managers noviadi a rachman, m.t. electrical engineering n.ariefrachman@gmail.com vita susanti, s.kom. computer science vitasusanti@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com graphic designer m redho kurnia, s.sn. graphic design muha058@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 © 2013 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 04, issue 1, july 2013 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has been accreditated by the indonesian institute of sciences (lipi) in april 2012. it started using open journal system (ojs) since the online publishing of the third volume released in july 2012. this journal has been indexed by directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), and indonesian publication index (ipi). recently it has been granted digital object identifier with the doi prefix 10.14203. this issue publishes eight papers, all are written in english, with the total number of paper pages are 64 pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. two topics are related to mechatronics, four topics to electrical power and two topics to vehicular technology. the policy up to this current issue is that both authors and readers are not charged at all. on the other hand, the editorial board is planning to elevate the quality by registering the journal to other international academic citation index. moreover, the editorial board is also considering to gradually increase the number of papers and journal’s pages. all of this plan will give consequence on financial burden. therefore, from the next issue,financial policy will probably change based on that condition. we wish to offer our thanks to all the editorial members and administration division of the research center for electrical power and mechatronics (rcepm) – indonesian institute of sciences (lipi) for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s international editorial board members and peer reviewers: prof. dr. taufik, prof. dr. rosli bin abu bakar, prof. dr. muhammad nizam, arko djajadi, ph.d., edi leksono, ph.d., dr. yuliadi erdani, dr. riza muhida, dr. ahmad agus setiawan, dr. rizqon fajar, dr. yoyon ahmudiarto, and dr.-ing. mochamad ichwan. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2013 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 04, issue 1, july 2013 list of contents autoregressive integrated adaptive neural networks classifier for eeg-p300 classification demi soetraprawata, arjon turnip 1-8 optimization for biogas power plants using automatic control of gas pressures dodiek ika candra, camilo andreas wilches tamayo 9-16 the influence of two cylinder diesel engine modification (idi to di) on the performance and its emission yanuandri putrasari, arifin nur, aam muharam 17-24 effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia ghalya pikra, andri joko purwanto, adi santoso 25-32 modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method noviadi arief rachman, agus risdiyanto, ade ramdan 33-40 imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism hendri maja saputra, zainal abidin, estiko rijanto 41-50 quality improvement evaluation of the modified diesel-electric train (krde) taufik hidayat, hilman syaeful alam 51-56 maximum power point tracking of photovoltaic system for traffic light application riza muhida, nor hilmi mohamad, ari legowo, rudi irawan, winda astuti 57-64 further articles can be found at www.mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 04, issue 1, july 2013 abstracts sheet e-issn: 2088-6985 date of issues: 30 july 2013 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. demi soetraprawata, arjon turnip (technical implementation unit for instrumentation development division – lipi, bandung) autoregressive integrated adaptive neural networks classifier for eeg-p300 classification mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 1-8, 6 ill, 0 tab, 19 ref. brain computer interface has a potency to be applied in mechatronics apparatus and vehicles in the future. compared to the other techniques, eeg is the most preferred for bci designs. in this paper, a new adaptive neural network classifier of different mental activities from eeg-based p300 signals is proposed. to overcome the over-training that is caused by noisy and non-stationary data, the eeg signals are filtered and extracted using autoregressive models before passed to the adaptive neural networks classifier. to test the improvement in the eeg classification performance with the proposed method, comparative experiments were conducted using bayesian linear discriminant analysis. the experiment results show that the all subjects achieve a classification accuracy of 100%. (author) keywords: brain computer interface, feature extraction, classification accuracy, autoregressive, adaptive neural networks, eeg-based p300, transfer rate. dodiek ika candra a,b, camilo andreas wilches tamayo b (aresearch centre for electrical power & mechatronics, indonesian institute of sciences, bandung; bbwe biogas-weser-ems gmbh & co. kg, friesoy-germany) optimization for biogas power plants using automatic control of gas pressures mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 9-16, 13 ill, 2 tab, 13 ref. in many cases, gas storages on biogas power plants are not used optimally to store gas as much as their capacity. the digester is sometimes overload to store gas and the controller cannot deliver gas to other storage. consequently, gas is often released from digester to avoid over pressure. at the end, biogas power plant has less efficiency. hence, a mechanism to control gas pressure to make different pressure between its storages is required. fans were used to manipulate the most majority system pressures on a biogas power plant using frequency converters. measurements, simulations, and experiments were conducted to create a new system on a biogas power plant. a controller, programmable logic controller was used to control the entire system pressure using proportional-integralderivative algorithm. when the gas pressures are not in the allowable range of pressure, then the controller changes the fans’ frequency to the desired conditions. as a result, gas moves to another storage and system pressures are in the allowable range. (author) keywords: control biogas pressures, biogas storages optimization, biogas system pressure. yanuandri putrasari, arifin nur, aam muharam (research centre for electrical power and mechatronics, indonesian institute of sciences, bandung) the influence of two cylinder diesel engine modification (idi to di) on the performance and its emission mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 17-24, 10 ill, 3 tab, 19 ref. modification of combustion system from indirect injection (idi) to direct injection (di) was carried out on the two cylinder diesel engine, followed with tests for performance and emission. the modification from idi to di was conducted on a two cylinder diesel engine by removing the pre-chamber from the inside of the cylinder head, replacing the injector and its position to the top of the combustion chamber directly and also replacing the original piston with a piston that has a bowl on the crown. performance and emission tests were conducted on 1,500 rpm with loads that vary from 0, 10, 20, 30, 40, 50, to 60 nm. the investigation results of the diesel engine modification from idi to di showed several interesting phenomena. further research is needed in order to increase the engine performance and reduce its emission. (author) keywords: diesel, idi, di, performance, emission. ghalya pikra, andri joko purwanto, adi santoso (research centre for electrical power & mechatronics, indonesian institute of sciences, bandung) effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 25-32, 12 ill, 3 tab, 28 ref. this paper presents effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia. solar thermal power is a plant that uses solar energy as heat source. indonesia has high humidity level, so that parabolic trough is the most suitable type of solar thermal power technology to be developed, where the design is made with small focal distance. organic rankine cycle (orc) is a rankine cycle that use organic fluid as working fluid to utilize low temperature heat sources. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv rorc is used to increase orc performance. the analysis was done by comparing orc system with and without regenerator addition. refrigerant that be used in the analysis is r123. preliminary data was taken from the solar collector system that has been installed in yogyakarta. the analysis shows that with 36 m total parabolic length, the resulting solar collector capacity is 63 kw, heat input/evaporator capacity is determined 26.78 kw and turbine power is 3.11 kw for orc, and 3.38 kw for rorc. orc thermal efficiency is 11.28% and rorc is 12.26%. overall electricity efficiency is 4.93% for orc, and 5.36% for rorc. with 40°c condensing temperature and evaporation at 10 bar saturated condition, efficiency of rorc is higher than orc. greater evaporation temperature at the same pressure (10 bar) provide greater turbine power and efficiency. (author) keywords: solar thermal power, parabolic trough, regenerative organic rankine cycle, regenerator, r123. noviadi arief rachman a, agus risdiyanto a, ade ramdan b (aresearch centre for electrical power and mechatronics, indonesian institute of sciences, bandung; bresearch centre for informatics, indonesian institute of sciences, bandung) modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 33-40, 15 ill, 1 tab, 13 ref. charge simulation method is one of the field theory that can be used as an approach to calculate the electromagnetic distribution on the electrical conductor. this paper discussed electric field modeling around power transformator by using mat lab to find the safety distance. the safe distance threshold of the electric field to human health refers to who and sni was 5kv/m. the specification of the power transformator was three phases, 150/20kv, and 100mva. the basic concept is to change the distribution charge on the conductor or dielectric polarization charge with a set of discrete fictitious charge. the value of discrete fictitious charge was equivalent to the potential value of the conductor, and became a reference to calculate the electric field around the surface contour of the selected power transformator. the measurement distance was 5 meter on each side of the transformator surface. the results showed that the magnitude of the electric field at the front side was5541 v/m, exceeding the safety limits. (author) keywords: electric field, charge simulation method, discrete charge, power transformator. hendri maja saputra a, zainal abidin b, estiko rijanto a (aresearch center for electrical power & mechatronics, indonesian institute of sciences, bandung; bfaculty of mechanical and aerospace engineering, institut teknologi bandung) imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 41-50, 18 ill, 8 tab, 14 ref. this paper describes a modeling and designing of inertial sensor using inertial measurement unit (imu) to measure the position and orientation of a vehicle motion. sensor modeling is used to derive the vehicle attitude models where the sensor is attached while the sensor design is used to obtain the data as the input to control the angles of a pan-tilt mechanism with 2 degrees of freedom. inertial sensor phidget spatial 3/3/3, which is a combination of 3-axis gyroscope, 3-axis accelerometer and 3-axis magnetometer, is used as the research object. software for reading the sensor was made by using matlab™. the result shows that the software can be applied to the sensor in the real-time reading process. the sensor readings should consider several things i.e. (a) sampling time should not be less than 32 ms and (b) deviation ratio between measurement noise (r) and process noise (q) for the parameters of kalman filter is 1:5 (i.e. r = 0.08 and q = 0.4). (author) keywords: imu, pan-tilt, gyroscope, accelerometer, magnetometer, kalman filter. taufik hidayat, hilman syaeful alam (technical implementation unit for instrumentation development lipi, bandung) quality improvement evaluation of the modified diesel-electric train (krde) mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 51-56, 14 ill, 2 tab, 10 ref. quality of the diesel-electric train (krde) modified from the electric train (a and b types) which were used in three operating regions in the indonesian railway company has been evaluated by analyzing the cause of the krde damages in terms of some aspects including: design, components quality, maintenance (method, finance, human resources), environment and way of operation. based on the evaluation it was found that the modification of the both types of krde provided a very low reliability and availability due to design and technical problems, as well as unoptimal maintenance. in krde type a, damage occurs in the cabling system, compressor, radiator fan system, and the braking system. while in type b, damage occurs in the traction motors, static inverter, and radiator fan. it is predicted that their life span can not reach the design life of 25 years, and even they are expected to be grounded. many improvement is required to lengten their service life including: repair, modification, human resource competence, facilities, spare parts, maintenance and management. (author) key words: quality improvement, diesel-electric train, damage, maintenance, operation. riza muhida a, nor hilmi mohamad b, ari legowo c, rudi irawan a, winda astuti b (asurya university, tangerang, bdepartment of mechatronics engineering, international islamic university malaysia, kuala lumpur, malaysia, cdepartment of mechanical engineering, international islamic university malaysia, kuala lumpur, malaysia) maximum power point tracking of photovoltaic system for traffic light application mechatronics, electrical power, and vehicular technology, july 2013, vol. 4, no. 1, p. 57-64, 18 ill, 2 tab, 13 ref. photovoltaic traffic light system is a significant application of renewable energy source. the development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. since photovoltaic (pv) modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (mppt) method is applied to the traffic light system. mppt is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. mppt is actually a dc-dc converter that can step up or down voltage in order to achieve the maximum power using pulse width modulation (pwm) control. from experiment, we obtained the voltage of operation using mppt is at 16.454 v, this value has error of 2.6%, if we compared with maximum power point voltage of pv module that is 16.9v. based on this result it can be said that this mppt control works successfully to deliver the power from pv module to battery maximally. (author) keywords: photovoltaic, maximum power point tracking, traffic light, voltage converter, battery charging. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal providing authoritative source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, tubine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev’s vision is to become international platform with high scientific contribution for global community. mev’s mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi) and managed to be issued twice in every volume. the first issue should be in the mid of the year and the second issue is in the end of the year. issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: www.mevjournal.com mev allows reuse and remixing of its content, in accordance with a cc license of cc by-nc-sa. article management & plagiarism check every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. accepted article to be published in mev journal will be proofed using grammarly® checker software. plagiarism screening will be conducted by mev editorial board using grammarly® plagiarism checker. article processing charges every article submitted to mev journal will not have any article processing charges. this includes peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. indexing & abstracting indexed in ebscohost, index copernicus, directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), indonesian publication index (ipi), crossref, mendeley, citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi) by 15 april 2015. accreditation number: 633/au/p2mi-lipi/03/2015 valid thru: 15 april 2020. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034, hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia za@dynamic.pauir.itb.ac.id prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia, depok, indonesia, dasumarsono@gmail.com george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id advisory editor ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id mailto:patko@uni-obuda.hu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 deputy editors aam muharam, m.t. electrical engineering aam.muharam@lipi.go.id tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com managing editors, central office ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com managing editor, asia pacific region yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id managing editor, europe region naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com section editors agus risdiyanto, m.t. electrical engineering riesdian@gmail.com amin, m.t. electrical engineering amin_hwi@yahoo.co.id arini wresta, m.eng. chemical engineering awresta@gmail.com bambang wahono, m.eng. mechanical engineering bambangwahono80@yahoo.co.id dian andriani, m.eng. bioenergy engineering dea1401@yahoo.com hendri m saputra, m.t. robotics and mechatronics hendri_maja@yahoo.co.id kadek heri sanjaya, ph.d ergonomics, biomechanics, physiology kade001@lipi.go.id midriem mirdanies, m.t. computer engineering midr001@lipi.go.id muhammad kasim, m.renen electrical engineering kasime99uh@yahoo.co.id nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com vita susanti, s.kom computer science vitasusanti@gmail.com layout editors aditya sukma nugraha, m.t. mechanical engineering aditngrh@gmail.com arief a firdaus, s.i.kom. communication science rif212@yahoo.com maulana arifin, m.t. mechanical engineering maul004@lipi.go.id rakhmad indra pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com yayat ruhiyat, a.md. electrical engineering yayatruhi@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com henny sudibyo, m.eng industrial engineering hennysudibyo@yahoo.com graphic designer yukhi mustaqim kusuma sya bana, s.sn. graphic design yuqmail@yahoo.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 © 2015 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has been indexed by google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib and cite factor. in addition, digital object identifier (doi) has been granted to our journal with doi prefix 10.14203. in this issue, seven papers are published with the total number of paper pages of 66 pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. three topics of the papers are related to mechatronics which address dynamical model of fixed wing uav, control of quadrotors uav and development of wireless accelerometer. two topics are related to electrical power concerning radial rotor turbo-expander design for small organic rankine cycle system and prediction of battery state of charge using particle swarm optimization. modeling, identification, estimation and simulation of urban traffic flow as well as economic valuation of hypothetical paratransit retrofitting are also presented in this issue. since the first issue, our journal provides discretion in financial term by waiving the article processing charge. we are planning to improve the quality by registering the journal to other international academic citation index. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2015 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 ii list of contents development of a microcontroller-based wireless accelerometer for kinematic analysis maria clarissa alvarez carasco, jan pierre potato pizarro, giovanni alarkon tapang 1-8 a modified gain schedulling controller by considering the sparseness property of uav quadrotors m qodar abdurrohman, reka inovan, ahmad ataka, hilton tnunay, ardhimas wimbo, iswanto, adha cahyadi, yoshio yamamoto 9-18 nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung fadjar rahino triputra, bambang riyanto trilaksono, trio adiono, rianto adhy sasongko, mohamad dahsyat 19-30 prediction model of battery state of charge and control parameter optimization for electric vehicle bambang wahono, kristian ismail, harutoshi ogai 31-38 geometry analysis and effect of turbulence model on the radial rotor turbo-expander design for small organic rankine cycle system maulana arifin, ari darmawan pasek, zaidan eddy 39-48 economic valuation of hypothetical paratransit retrofitting naili huda, kim peter hassall, sunarto kaleg, abdul hapid 49-56 modeling, identification, estimation, and simulation of urban traffic flow in jakarta and bandung herman y. sutarto, endra joelianto 57-66 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 06, issue 1, july 2015 abstracts sheet e-issn: 2088-6985 date of issues: 30 july 2015 p-issn: 2087-3379 the descriptions given are free terms. this abstracts sheet may be reproduced without permission or change. maria clarissa alvarez carascoa, jan pierre potato pizarroa, giovanni alarkon tapanga (aversatile instrumentation system for science education and research national institute of physics, university of the philippines diliman, quezon city, philippines) development of a microcontroller-based wireless accelerometer for kinematic analysis journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 1-8, 9 ill, 0 tab, 15 ref. wireless sensor networks (wsns) allow real-time measurement and monitoring with less complexity and more efficient in terms of obtaining data when the subject is in motion. it eliminates the limitations introduced by wired connections between the sensors and the central processing unit. although wireless technology is widely used around the world, not much has been applied for education. through versatile instrumentation system for science education and research (visser), a project which aims to develop modern science laboratory equipment for high school education and research in the philippines, a low cost wsn using nrf24l01+ rf transceiver that is developed to observe and analyze the kinematics of a moving object is discussed in this paper. data acquisition and transmission is realized with the use of a low power and low cost microcontroller attiny85 that obtains data from the adxl345 three-axis accelerometer. an attiny85 also controls the receiving module with a uart connection to the computer. data gathered are then processed in an open-source programming language to determine properties of an object’s motion such as pitch and roll (tilt), acceleration and displacement. this paper discusses the application of the developed wsn for the kinematics analysis of a toy car moving on flat and inclined surfaces along the three axes. the developed system can be used in various motion detection and other kinematics applications, as well as physics laboratory activities for educational purposes. (author) keywords: wireless sensor network; accelerometer; kinematics; nrf24l01+. m. qodar abdurrohmana, reka inovana, ahmad atakaa, hilton tnunaya, ardhimas wimboa, iswantoa, adha cahyadia, yoshio yamamotob (adepartment of electrical engineering and information technology, gadjah mada university, jalan grafika 2, yogyakarta 55281; bdepartment of precision engineering, school of engineering, tokai university 1117 hiratsuka-shi, kanagawa-ken, japan) a modified gain scheduling controller by considering the sparseness property of uav quadrotors journal of mechatronics, electrical power, and vehicular technology, july 2015, vol.6, no. 1, p. 9-18,15 ill, 0 tab, 9 ref. this work presented the gain scheduling based lqr for quadrotor systems. from the original nonlinear model, the system is always controllable and observable in various equilibrium points. moreover, the linearized systems have a unique property that is known as sparse system. hence, in order to implement the most efficient state feedback controller, post-filter and pre-filter were introduced to transform the state coordinate to decrease coupling between states. finally, the gain scheduling systems using these facts was proposed. the system behavior was tested using the proposed controller. the numerical studies showed the effectiveness of the controller to achieve desired altitude, attitude, and its ability during the disturbance. (author) keywords: quadcopters; sparse system; linearization; gain scheduling; pole-placement. fadjar rahino triputraa,c, bambang riyanto trilaksonoa, trio adionoa, rianto adhy sasongkob, mohamad dahsyatc (aschool of electrical engineering and informatics, institut teknologi bandung, jl. ganesha 10, bandung, indonesia; bfaculty of mechanical and aerospace engineering, institut teknologi bandung, jl. ganesha 10, bandung, indonesia; cagency for the assessment and application of technology (bppt), komplek puspiptek serpong, tangerang, indonesia) nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 19-30, 10 ill, 1 tab, 12 ref. developing a nonlinear adaptive control system for a fixed-wing unmanned aerial vehicle (uav) requires a mathematical representation of the system dynamics analytically as a set of differential equations in the form of a strict-feedback systems. this paper presents a method for modeling a nonlinear flight dynamics of the fixed-wing uav of bppt wulung in any conditions of the flight altitude and airspeed for the first step into designing a nonlinear adaptive controller. the model was formed into 10-dof differential equations in the form of strictfeedback systems which separates the terms of elevator, aileron, rudder, and throttle from the model. the model simulation results show the behavior of the flight dynamics of the wulung uav and also prove the compliance with the actual flight test results. (author) keywords: fixed-wing uav; nonlinear flight dynamics; strictfeedback systems. bambang wahonoa, kristian ismaila, harutoshi ogaib (aresearch centre for electrical power and mechatronics, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 20 lantai 2 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv bandung, 40135, indonesia; bgraduate school of information, production and systems, waseda university 2-7 hibikino, wakamatsu-ku, kitakyushu, fukuoka 808-0135, japan) prediction model of battery state of charge and control parameter optimization for electric vehicle journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 31-38, 6 ill, 5 tab, 15 ref this paper presents the construction of a battery state of charge (soc) prediction model and the optimization method of the said model to appropriately control the number of parameters in compliance with the soc as the battery output objectives. research centre for electrical power and mechatronics, indonesian institute of sciences has tested its electric vehicle research prototype on the road, monitoring its voltage, current, temperature, time, vehicle velocity, motor speed, and soc during the operation. using this experimental data, the prediction model of battery soc was built. stepwise method considering multicollinearity was able to efficiently develop the battery prediction model that describes the multiple control parameters in relation to the characteristic values such as soc. it was demonstrated that particle swarm optimization (pso) succesfully and efficiently calculated optimal control parameters to optimize evaluation item such as soc based on the model. (author) keywords: soc; stepwise method; multicollinearity; electric vehicle; particle swarm optimization. maulana arifina, ari darmawan pasekb, zaidan eddya (aresearch centre for electrical power and mechatronics, indonesian institute of sciences, jl. cisitu/sangkuriang, bandung 40135, indonesia; bthermodynamics laboratory, faculty of mechanical and aerospace engineering, bandung institute of technology) geometry analysis and effect of turbulence model on the radial rotor turbo-expander design for small organic rankine cycle system journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 39-48, 7 ill, 4 tab, 11 ref. organic rankine cycle (orc) is one of the most promising technology for small electric power generations. the geometry analysis and the effect of turbulence model on the radial turboexpanders design for small orc power generation systems were discussed in this paper. the rotor blades and performance were calculated using several working fluids such as r134a, r143a, r245fa, n-pentane, and r123. subsequently, a numerical study was carried out in the fluid flow area with r134a and r123 as the working fluids. analyses were performed using computational fluid dynamics (cfd) ansys multiphysics on two real gas models, with the k-epsilon and shear stress transport (sst) turbulence models. the result shows the distribution of mach number, pressure, velocity and temperature along the rotor blade of the radial turboexpanders and estimation of performance at various operating conditions. the operating conditions are as follow: 250,000 grid mesh flow area, real gas model sst at steady state condition, 0.4 kg/s of mass flow rate, 15,000 rpm rotor speed, 5 bar inlet pressure, and 373k inlet temperature. by using those conditions, cfd analysis shows that the turbo-expander able to produce 6.7 kw and 5.5 kw of power when using r134a and r123, respectively. (author) keywords: radial turbo-expander; cfd; k-epsilon; shear stress transport; organic rankine cycle. naili hudaa, kim peter hassallb, sunarto kalega, abdul hapida (aresearch centre for electrical power and mechatronics, indonesian institute of sciences, jl. cisitu/sangkuriang, bandung 40135, indonesia; bdepartment of infrastructure engineering, the university of melbourne level 02 room c201 engineering block c, parkville 3010, australia) economic valuation of hypothetical paratransit retrofitting journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 49-56, 1 ill, 9 tab, 48 ref. this paper describes a feasibility analysis of conventional and retrofitted paratransits, comparing economic performance of conventional paratransit with those using lead acid and lithium batteries. research object is dago-kalapa paratransit in bandung, west java, travelling the distance of 11 km in town, under 8 peak hour operation. after calculating the estimated annual cost and benefit; net present value (npv), payback period (pbp) and internal rate of return (irr) then were quantified to provide feasibility description of those three paratransits. in addition, a sensitivity analysis regarding discount rate, gasoline price and battery price is given to offer broader sense of factors embraced. it is found that both gasoline and lead acid paratransit have big npvs with only slight differences, while lithium paratransit has negative npv. this phenomenon applies to their pbps and irrs as well. only when gasoline costs reaches idr 15,000 will electric paratransit prevails over conventional one. thus, it can be inferred that at the moment, paratransit runs with gasoline is still the most cost effective compared to its counterparts. however, starting retrofitting from now is endorsed due to its environmental benefit. (author) keywords: feasibility; paratransit; conventional; electric; bandung; indonesia. herman y. sutartoa, endra joeliantob (asystems research group, universiteit gent technologiepark 913, b-9052 zwijnaarde, belgium; binstrumentation and control research group, institut teknologi bandung, jalan ganesha 10, bandung 40132, indonesia) modeling, identification, estimation, and simulation of urban traffic flow in jakarta and bandung journal of mechatronics, electrical power, and vehicular technology, july 2015, vol. 6, no. 1, p. 57-66, 6 ill, 1 tab, 11 ref. this paper presents an overview of urban traffic flow from the perspective of system theory and stochastic control. the topics of modeling, identification, estimation and simulation techniques are evaluated and validated using actual traffic flow data from the city of jakarta and bandung, indonesia, and synthetic data generated from traffic micro-simulator vissim. the results on particle filter (pf) based state estimation and expectation-maximization (em) based parameter estimation (identification) confirm the proposed model gives satisfactory results that capture the variation of urban traffic flow. the combination of the technique and the simulator platform assembles possibility to develop a real-time traffic light controller. (author) keywords: intelligent transportation system; stochastic hybrid system; state/parameter estimation; expectation-maximization; particle filter. mev mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.87-94 analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator kajian defleksi analitis dan numerik pada struktur generator magnet permanen kecepatan rendah kapasitas 10 kw hilman s. alam a, *, pudji irasari b, dyah kusuma dewi c a technical implementation unit for instrumentation development, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 30 bandung, 40135, indonesia b research center for electrical power and mechatronics, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 20 lantai 2 bandung, 40135, indonesia c directorate of technology for manufacturing industry, agency for assessment and application of technology, gedung teknologi 2 puspitek serpong, tangerang, indonesia received 23 october 2012; received in revised form 01 december 2012; accepted 03 december 2012 published online 18 december 2012 abstract analytical and numerical studies of the deflection in the structure of 10 kw low speed permanent magnet generator (pmg) have been discussed in this paper. this study is intended to prevent failure of the structure when the prototype is made. numerical analysis was performed with the finite-element method (fem). flux density, weight and temperature of the components are the required input parameters. deflection observed were the movements of the two main rotor components, namely the rim and shaft, where the maximum deflection allowed at the air gap between rotor and stator should be between 10% to 20% of the air gap clearance or 0.1000 mm to 0.2000 mm. base on the analysis, total deflection of the analytic calculation was 0.0553 mm, and numerical simulation was 0.0314 mm. both values were in the acceptable level because it was still below the maximum allowed deflection. these results indicate that the structure of a permanent magnet generator (rim and shaft) can be used safely. key words: permanent magnet generator, finite element, air gap, deflection. abstrak studi secara analitis dan numerik mengenai defleksi pada struktur generator magnet permanen (gmp) kecepatan rendah kapasitas 10 kw telah dibahas dalam makalah ini. studi ini dimaksudkan untuk mencegah kegagalan struktur saat prototipe sudah dibuat. analisis numerik dilakukan dengan metode elemen hingga (meh). kerapatan fluks, berat dan suhu komponen merupakan parameter-parameter masukan. defleksi yang diamati adalah gerakan dua komponen utama rotor yaitu rim dan poros, di sini defleksi maksimum yang diizinkan pada celah udara antara rotor dan stator harus berkisar antara 10% sampai 20% dari clearance celah udara atau 0,1000 mm sampai 0,2000 mm. berdasarkan hasil analisis, defleksi total hasil perhitungan analitis adalah 0,0553 mm sedangkan simulasi numerik adalah 0,0314 mm. kedua nilai tersebut memenuhi persyaratan karena masih di bawah defleksi maksimum yang diizinkan. hasil tersebut menunjukkan bahwa struktur generator magnet permanen (rim dan poros) dapat digunakan secara aman. kata kunci: generator magnet permanen, elemen hingga, celah udara, defleksi. i. introduction in general, the constructions of low-speed high torque permanent magnet generators (pmg) tend to have large dimension, heavy and expensive. the major costs are caused by materials, installation and transportation. the construction of the radial flux pmg is dominated by the weight of inactive components that is equal to 2/3 of the total weight, while the rest is that of the active components (iron, copper, and permanent magnet) [1]. they serve as a support to keep the clearance at the air gap and to hold * corresponding author. tel: +62-81394297528 e-mail: alam_hilman@yahoo.com http://dx.doi.org/10.14203/j.mev.2012.v3.87-94 h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 88 the active components to stay in place when subjected to normal force, shear force and thermal effects. reducing the weight of generator is an issue of interest to designers and manufacturers. this is because the inactive structure of direct drive generator is directly connected to the prime mover and its weight can reach 80% of the total [1]. it is needed to counteract the magnetic attractive force between the stationary and moving parts and it is influenced by the type and nature of the material used. tensile stress is generated by normal/maxwell force that could reach ten times the shear stress. distance or clearance between the rotor and the stator must be maintained to avoid damage to the pmg [2,3]. research to find potential solutions in terms of geometry, materials and sources of excitation becomes an important issue to increase market competition, reducing prices and weights of components so that the efficiency and reliability of pmg can be improved [3]. design of the generator in this study is focused on the rotor shaft that serves as a support structure of active components. one important step in the design is stress analysis on the structure, which will find the number of iterations to meet allowable rotor deflection before manufacturing of prototypes. stress analysis based on an analytical approach then is validated by numerical methods or also called finite element method (fem). the method has been applied to the analysis of electromagnetic in some earlier studies [1-10]. several advantages over other numerical methods are: it gives detailed and exact analysis and computation [5][9]; it provides an efficient solution [6]; it is able to analyze various types of electrical machines, including permanent magnet parametric geometry, post processing and visualization of results [10]. ii. methodology clearance on generator is generally calculated as 1/1000 of the air gap diameter [1]. for 10 kw of capacity, the pmg with air gap radius, rg = 168.5 mm will need 0.1685 mm of clearance. the allowed deflection of the rotor ranges from 1020% [1]. figure 1 shows a cross-section of radial flux pmg. air gap between the stator and rotor is designed to be 1 mm, greater than it should be (0.1685 mm) due to manufacturing consideration, then the maximum deflection of the air gap clearance to be ranged between 0.100 mm to 0.200 mm. the parameters, which affect the deflection of the structure consist of flux density 𝐵𝐵�, mass of the component m and the temperature difference δt. they are used as inputs to calculate the normal stress, weight of the components and the thermal expansion of the material. design is analytically calculated and the results are validated using fem. the allowable maximum deflection is used as a consideration in the design iteration. input data is obtained from the calculation using the fem. figure 2 shows the method used in designing the structure of pmg to target 10-20% total deflection of the air gap clearance. a. the existence of forces on pmg the distance between the rotor and stator in the pmg, is one of the most critical factors in the design considerations. besides affected by weight of the part itself, deflection is also influenced by the air gap flux density. if it increases, the normal figure 1. cross section of the radial flux pmg. figure 2. design methodology of the pmg. h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 89 stress and deflection in the rotor will rise higher. in addition subjected to normal stresses, pmg is subjected to a shear stress as well. shear stress is one of the important factors in the design as it relates to the torque to be generated [1]. normal stresses on pmg occur in the normal direction or lead directly to the air gap, see figure 3. normal stresses on the stator and rotor move in and out radially and are larger than the shear stress. when the flux density, 𝐵𝐵� in the air gap rises (during operation: 𝐵𝐵� >0.8t), the normal stress, which will be produced is around 10 times the shear stress. the normal stress 𝑞𝑞 is a function of the square of the air gap flux density [1]: 𝑞𝑞 = 𝐵𝐵 �2 2𝜇𝜇𝑡𝑡 [pa] (1) where: 𝐵𝐵�: air gap flux density [t or n/am] and µo: permeability of free space (1.26 × 10-6 n/a2). shear stress 𝜎𝜎� [pa] is the most important variable in the design and is proportional to the generated torque as represented by the equation [1]: 𝑇𝑇 = 2𝜋𝜋𝜎𝜎�𝑅𝑅2𝑙𝑙[n.m] (2) where: r = radius of pmg [m] and l = axial length of the pmg [m]. shear stress 𝜎𝜎� [pa] acting on the pmg is perpendicular or cut the air gap, see figure 4. when the wave of flux density 𝐵𝐵� [t or n/am] and the electric load 𝐾𝐾� is sinusoidal at an angle δ [a/m], the shear stress is [1]: 𝜎𝜎� = 1 2 𝐵𝐵�𝐾𝐾�[pa] (3) b. thermal expansion besides influenced by the normal force and weight of the components, the air gap clearance is affected by dimensional changes due to heating. the heat arising from the losses occurred in the pmg causes the temperature rise and the expansion of the components. the difference in temperature rise between the stator and the rotor will cause changes in the air gap clearance, see figure 5. dimensional changes due to thermal expansion are calculated as [1]: ∆𝐿𝐿 = 𝐿𝐿𝑡𝑡𝛼𝛼∆𝑇𝑇 (4) where ∆𝑙𝑙 : dimensional changes [m], 𝛼𝛼 : coefficient of thermal expansion of the material [°c-1], 𝑙𝑙𝑡𝑡: initial length [m], and ∆𝑇𝑇: temperature rise [°c]. c. designing rim rim on the rotor serves as a retaining structure and the permanent magnet holder as demonstrated in figure 6. in this study, it uses steel with young's modulus of 200 gpa. deflection on the rim, 𝑈𝑈𝐴𝐴 is calculated using [1, 10]: figure 3. cross-section of the pmg with normal voltage along the air gap. figure 5. expansion due to temperature rise in the stator ∆ts and rotor ∆tr. figure 4. cross section of the pmg with shear stress along the air gap. figure 6. cross section area of the rim. h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 90 𝑈𝑈𝐴𝐴 = 𝑞𝑞𝑅𝑅2 𝐸𝐸ℎ𝑦𝑦𝑟𝑟 ⎩ ⎪ ⎨ ⎪ ⎧ 1 + 𝑅𝑅3�𝑘𝑘1 (𝑠𝑠𝑙𝑙𝑛𝑛𝑠𝑠 −𝑠𝑠𝑐𝑐𝑡𝑡𝑠𝑠𝑠𝑠 ) 4𝑠𝑠𝑙𝑙𝑛𝑛 2 𝑠𝑠 − 𝑘𝑘2 2𝑠𝑠𝑙𝑙𝑛𝑛𝑠𝑠 +𝑘𝑘2 2 2𝑠𝑠 � 𝐼𝐼�� 𝑠𝑠 𝑠𝑠𝑙𝑙𝑛𝑛 2 𝑠𝑠 + 1 𝑡𝑡𝑝𝑝𝑛𝑛𝑠𝑠 �� 𝑅𝑅 4𝐴𝐴 +𝑅𝑅 3 4𝐼𝐼 �−𝑅𝑅 3 2𝐼𝐼𝑠𝑠 � 1 �𝑘𝑘𝑅𝑅� 2 +1 �+𝑅𝑅1−𝑅𝑅𝑡𝑡 𝑝𝑝 � ⎭ ⎪ ⎬ ⎪ ⎫ [mm] (5) where, r : radius of the neutral axis at the rim (143.5 mm), ro: radius of the shaft (50 mm), ri: radius of the rim surface (135 mm), θ: angle between the two rim (30°), a: cross-section area of the arm retaining rim (43,975 mm2), a: crosssection area of the rim, 20,781 mm2, i: moment of inertia rim (258,575,015 mm4), k: radius of the rim gyration (𝑘𝑘 = �𝐼𝐼/𝐴𝐴 = 76.68 𝑚𝑚𝑚𝑚), k1 and k2: the correction factor of stress concentration due to momen and shear stress, and hyr: thickness of the rim (10 mm). stress concentration at the retaining structure of the rim will result in a correction factor due to the moments and shear forces, see figure 7. by assuming the geometry of the structure is in the form of ellipse, the correction factor can be calculated with the equation [10]: 𝑘𝑘1 = 𝐶𝐶1 + 𝐶𝐶2 � 2𝑝𝑝 𝐷𝐷 � + 𝐶𝐶3 � 2𝑝𝑝 𝐷𝐷 � 2 (6) for 0.4 ≤ 2𝑝𝑝/𝐷𝐷 ≤ 1.0, then : 𝐶𝐶1 = 3.465 − 3.739 × � 𝑝𝑝 𝑐𝑐 + 2.274 × 𝑝𝑝 𝑐𝑐 (7) 𝐶𝐶2 = −3.841 + 5.582 × � 𝑝𝑝 𝑐𝑐 − 1.741 × 𝑝𝑝 𝑐𝑐 (8) 𝐶𝐶3 = 2.376 − 1.843 × � 𝑝𝑝 𝑐𝑐 − 0.534 × 𝑝𝑝 𝑐𝑐 (9) the correction factor due to the influence of shear force is represented by [10]: 𝑘𝑘2 = 𝐶𝐶1 + 𝐶𝐶2 � 2𝑝𝑝 𝐷𝐷 � + 𝐶𝐶3 � 2𝑝𝑝 𝐷𝐷 � 2 + 𝐶𝐶4 � 2𝑝𝑝 𝐷𝐷 � 3 (10) for 0.5 ≤ 𝑝𝑝/𝑐𝑐 ≤ 10.0, then: 𝐶𝐶1 = 1.000 + 2.000 × 𝑝𝑝 𝑐𝑐 (11) 𝐶𝐶2 = −0.351 − 0.021 × � 𝑝𝑝 𝑐𝑐 − 2.483 × 𝑝𝑝 𝑐𝑐 (12) 𝐶𝐶3 = 3.621 − 5.183 × � 𝑝𝑝 𝑐𝑐 + 4.494 × 𝑝𝑝 𝑐𝑐 (13) 𝐶𝐶4 = −2.270 + 5.204 × � 𝑝𝑝 𝑐𝑐 − 4.011 × 𝑝𝑝 𝑐𝑐 (14) d. shaft design shaft diameter is designed based on analytical calculations with the data inputs are weight of the components. figure 8 shows the design of the rotor shaft construction of the pmg. the mass that must be supported by the shaft is obtained from the data of geometry and density of the permanent magnet material and rim. based on figure 8, diagram of a simple freebody can be modeled to calculate the load and deflection in the shaft (see figure 9). force f1 is generated from the input torque to rotate the generator while the force f2 is generated from normal weight of the rim and the magnet. these two forces are detained by the reaction forces on the bearing ra and rb. to find out-loading on the shaft, the following static equilibrium equations are used [12]: �σ𝐹𝐹 = 0 σ𝑀𝑀 = 0 � (15) the maximum shear stress on the shaft 𝜏𝜏 [mpa] is [12]: 𝜏𝜏 = 0.5𝜎𝜎𝑦𝑦𝑝𝑝 𝐹𝐹𝑠𝑠 = 16 𝜋𝜋𝑑𝑑3 �((𝐶𝐶𝑚𝑚𝑀𝑀)2 + (𝐶𝐶𝑡𝑡𝑇𝑇)2 ) (16) where: 𝜎𝜎𝑦𝑦𝑝𝑝 : yield strength of the material (250 mpa for steel st 45), 𝐹𝐹𝑠𝑠 : safety factor, m: the maximum moment on the shaft [n.m], t: the maximum torque on the shaft from the design power [n.m], cm: the fatigue life factor and shock loads (1.5 for initial sudden load), ct: figure 7. correction factor due to: (a) moment and (b) shear force. figure 8. rotor shaft construction. h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 91 factor influenced by torque/twist (1.0 for small vibration) [11]. based on the relationship between strain and torque curves for elastic material, shaft deflection is calculated by the equation [12]: 𝑑𝑑2𝑣𝑣 𝑑𝑑𝑥𝑥 2 = 𝑀𝑀 𝐸𝐸𝐼𝐼 (17) where 𝑣𝑣: the elastic deflection curve [m], m: the maximum moment on the shaft [mpa], e: modulus of elasticity of the shaft material [mpa] and i: moment of inertia of the shaft [m4]. by integrating the equation and inserting the boundary conditions on the support or bearing then the maximum deflection on the shaft can be known. e. finite element method in general, analysis procedure using fem consists of three steps: preprocessing, field solution, and post processing. preprocessing comprises meshing and defining the material sand problems. in the meshing process, the continuum or area is divided into a set of finite number of elements. defining the materials includes determination of the types of material in the sub-region, while defining the problems is the determination of the boundary conditions required as input in the calculation. field processing is the solution of partial differential equation based on minimizing the energy function, which is a mathematical function that relates to the potential energy stored in the system. post processing is the extraction of the solution into a quantitative value in the form of graphs that contains all the parameters, and critical value [4]. iii. result and discussion a. rim deflection input data to get the rim deflection is the air gap flux density, which is calculated using the finite element solver femm4.2 [17]. the maximum flux density 𝐵𝐵� to one pole is 1.05 t, see figure 10. with reference to eq.(1), the normal stress q is 438.67 kn/m2. then based on eq.(6) to (9), the constants c1, c2 and c3 are 2.771, 0.582 and 1.355 respectively. the correction factor due to the moment k1 is 2.666. from eq.(10) to (14), the constants c1, c2 and c3 each is 5.095, -5.465 and 5.406. the correction factor due to the shear stress, k2 is 3.184. by substituting all constants and correction factors above into equation (5), 0.00452 mm of the total deflection at the rim ua is obtained. the result of analytical calculation of the rim deflection is further validated using fem. figure 11 shows the result of post processing. the maximum deflection at the rim is equal to 0.00791 mm, found at the end of the rim marked in red color. deflection on other areas of the rim is clearly visible in accordance with subdomains or elements. b. shaft deflection based on the geometry and material density data, the total mass that must be supported by the shaft is 29.833 kg. multiplying the gravitational acceleration 9.8 m/s2, thereby the load on the shaft due to the weight of the component f2 is 292.36 n. in designing the shaft, normal stresses arising from the flux density in the air gap could be ignored because the direction is opposite to each other thus eliminating one another. from design data, the maximum power transmitted p = 10 kw and speed n = 600 rpm, as a result the maximum torque of the shaft is 159.26 n.m. assuming that 100 mm of a pulley diameter is mounted on the rotor then the force generated f1 is 3,184.8 n. according to moment equilibrium law (eq.(15)), the maximum moment acting on the shaft lies in the pedestal of the bearing a, with m = 462.75 n.m. by using eq.(16), the maximum stress in the shaft is 62.5 mpa. referring to the calculation results, the diameter of the shaft, which is safe from the aspect of loading with the minimum safety factor of 2 is 40 mm. however, for the ease of manufacturing, the shaft diameter is adapted to the diameter of the figure 9. free-body diagram on the shaft. figure 10. flux density distributions at air gap region for one pole. h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 92 common bearing in the market and 55 mm of the closest diameter is determined. by entering the boundary conditions of the bearing deflection equals to 0 then according to eq.(17) shaft deflection is 0.0518 mm, which is found at the end part or in the area of f1. shaft deflection resulted from fem simulation reaches its maximum value at 0.0246 mm or about 50% lower than the analytical calculation, see fig.12. while the deflection at the middle or on the rim support is close to zero. thus, 55 mm of shaft diameter is safe to use as rotor retaining structure. c. deflection due to thermal expansion of the material maximum permissible temperature of the permanent magnet (100°c) is a reference to calculate the thermal expansion of material between the stator and rotor. if the thermal expansion coefficient of steel is 2.13×10-6/°c, the ambient temperature is 25°c, rotor radius rr is 0.1680 m, and stator radius rs is 0.1685 m, then referring to eq.(4), the changes of rotor and stator diameters (δrr and δrs ) are 0.166 mm and 0.167 figure 11. deflection on the rim resulted from numerical simulation. figure 12. shaft deflection resulted from numerical simulation. h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 93 mm respectively. thereby the change in diameter due to thermal expansion will cause the increase of air gap opening of 0.001 mm. d. total deflection on the structure of pmg total deflection on the structure of pmg is the sum of the rim and shaft deflection and deflection due to thermal expansion of the material. table 1 shows the maximum deflection for each component and the total deflection on all structures. there is a little difference in the deflection between the analytical and simulation results; however, both are allowable because the values are still below the maximum allowable deflection (10% to 20% of the air gap clearance). iv. conclusion • analytical and numerical analysis of the deflection of generator structure have been discussed in this paper. • both analyses are each producing 0.0553 mm and 0.0314 mm of the total d e f l e c t i o n or about 43% di f f er e n t . nevertheless both are included in the safe deflection categories because the values are still below 10% to 20% of the air gap clearance. • based on the results, it can be concluded that 55 mm of the selected shaft rotor diameter can be safely used. acknowledgement the authors grateful to directorate of technology for manufacturing industry, agency for assessment and application of technology, for allowing numerical simulation using catia. moreover thanks to all the team members of electric machines in the research center for electrical power and mechatronics, indonesian institute of sciences forany assistance that has been given. references [1] a. s. mcdonald, m. a. mueller and h. polinder, “comparison of generator topologies for direct-drive wind turbines including structural mass,” proceedings of the international conference on electrical machines (icem06), chania, crete, 2-5 september 2006. [2] a. s. mcdonald, m. a. mueller and h. polinder, “structural mass in direct-drive permanent magnet electrical generators,” renewable power generation, vol. 2, pp. 315, 2008. [3] m. a. mueller and a. s. mcdonald, “a lightweight low speed permanent magnet electrical generator for direct-drive wind turbines,” wind energy, vol. 12, pp. 768780, 2009. [4] l. ovacik, “optimal design of nonlinier magnetic systems using finite elements,” journal of engineering and natural sciences, pp. 1-39, 2004. [5] y. dou, y. gu, j. zhu, h. chen, and y. yan, “analysis of a hybrid excitation synchronous generator using three dimensional magnetic field finite element method,” journal of the japan society of applied electromagnetics and mechanics, vol.is, pp. s69-s72, 2007. [6] m. s. widyan, “design, optimization, construction and test of rare-earth permanent-magnet electrical machines with new topology for wind energy applications,” elektrotechnik und informatik der technischen universität berlin, genehmigte dissertation, 2006. [7] m. s. widyan and r. e. hanitsch, “a novel directly coupled high-energy permanentmagnet sinusoidal three-phase generator for wind energy applications,” international conference and exhibition on green energy & sustainability for arid regions & mediterranean countries, 2009. [8] s.m. hosseini, m. a. mirsalim, and m. mirzaei, “design, prototyping and analysis of low-cost disc permanent magnet generator with rectangular flat-shaped magnets,” iranian journal of science & technology, transaction b, engineering, vol. 32, no. b3, pp 191-203, 2008. [9] e. schlemmer, “finite element analysis of electrical machines used in two-frequency indirect temperature rise tests,” international conference on renewable energies and power quality, 2009. [10] a. reinap, d. hagstedt, f. márquez, y. loayza, and m. alaküla, “development of a radial flux machine design environment,” ieee international conference on electrical machines, 2008. table 1. total maximum deflection on the structure of pmg. component max. deflection (mm) analytic numeric rim 0.0045 0.0078 shaft 0.0518 0.0246 termal expansion 0.0010 (analytic) total deflection 0.0553 0.0314 h.s. alam et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 87-94 94 [11] r.j. roark and w.c. young, “roark's formulas for stress and strain,” 7th ed., mcgraw-hill international, 2002. [12] spott, m.f., “design of machine elements,” prentice hall, tokyo, 2003. [13] e.p. popov, “mechanics of materials,” 2nd ed., prentice hall, usa, 1978. [14] o.c. zienkiewicz and r. l. taylor, “the finite element method,” 5th ed., vol.1 the basis, butterworth-heinemann, 2000. [15] d.v. hutton, “fundamentals of finite element analysis,” mcgraw−hill companies, 2004. [16] s.s. rao, “the finite element method in engineering,” 4th ed., elsevier science & technology books, 2004. [17] d. meeker, “finite element method magnetics,” version 4.2, user’s manual, 2009. imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.41-50 imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism hendri maja saputra a, *, zainal abidin b, estiko rijanto a aresearch centre for electrical power & mechatronics, indonesian institute of sciences kampus lipi, jl. sangkuriang, gd. 20, bandung 40135, indonesia bfaculty of mechanical and aerospace engineering, institut teknologi bandung jl ganesha 10, bandung 40132, indonesia received 19 february 2013; received in revised form 27 march 2013; accepted 27 march 2013 published online 30 july 2013 abstract this paper describes a modeling and designing of inertial sensor using inertial measurement unit (imu) to measure the position and orientation of a vehicle motion. sensor modeling is used to derive the vehicle attitude models where the sensor is attached while the sensor design is used to obtain the data as the input to control the angles of a pan-tilt mechanism with 2 degrees of freedom. inertial sensor phidget spatial 3/3/3, which is a combination of 3-axis gyroscope, 3-axis accelerometer and 3-axis magnetometer, is used as the research object. software for reading the sensor was made by using matlab™. the result shows that the software can be applied to the sensor in the real-time reading process. the sensor readings should consider several things i.e. (a) sampling time should not be less than 32 ms and (b) deviation ratio between measurement noise (r) and process noise (q) for the parameters of kalman filter is 1:5 (i.e. r = 0.08 and q = 0.4). keywords: imu, pan-tilt, gyroscope, accelerometer, magnetometer, kalman filter. i. introduction two degrees of freedom pan-tilt mechanism requires orientation information of its platform due to movement of the vehicle in which it is fixed [1]. the orientation data can be read by an inertial measurement unit (imu). in this paper imu is positioned as a part of attitude and heading references system (ahrs) and inertial navigation system (ins) as shown in figure 1 [2]. ahrs can be used in a various applications such as land vehicles (e.g. cars, trains, and mobile robots), ships, and aircraft (eg.uav [3]). attitude modeling process in fact is quite complicated due to the error of sensor data which leads/causes the error accumulation in the calculation [2]. advanced technology has developed a high precision and reliable imu sensor using microelectro-mechanical systems (mems). an advanced imu is constructed with a combination of the three coordinate axis orientation complementary, where each axis consists of gyroscope (angular rate), accelerometer (acceleration), and magnetometer (flux) [4]. attitude or orientation can be represented by a three-way, i.e. (a) roll, pitch and yaw (rpy) or bank, elevation, and heading (beh) with euler angle zyx method [5], (b) direction cosine matrix, and (c) quaternion. the advantages and disadvantages of the three methods of representation are discussed in detail by nguyen [6]. euler angle is very intuitive and is widespread used, but has the disadvantage that it will have a singularity if the angle closes to 90º [3, 6-7]. there are two approaches that are commonly used for attitude calculation. the first (relative attitude) is the attitude calculated based on inertial mechanization which uses discrete time integral of the rotational velocity measurements using data from 3-axis gyroscope. angle resulting from this approach is roll, pitch and yaw (rpy). in this case, the determination of attitude does not depend on the value of the previous measurements and will always have a drift, for it requires correction compensation continuously. the second (absolute attitude) is calculated based on recent measurements of the data from accelerometer and magnetometer, using analytic * corresponding author. tel: +62-8138-1006-059 e-mail: hendri_maja@yahoo.co.id http://dx.doi.org/10.14203/j.mev.2013.v4.41-50 h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 42 geometry. angle resulting from this approach is the bank, elevation, and heading (beh). bank and elevation are obtained from gravity vector measured by accelerometer, while heading is calculated from magnetometer and bankelevation angle [3, 7]. orientation of the magnetic field must mathematically be rotated to the horizontal plane. if it is not rotated to the horizontal plane heading calculation would result in a considerable error [8]. the most fundamental problem in imu sensor is noise in the form of white noise [9] which can lead to inaccuracy and imprecision of attitude calculation. methods to minimize the noise using a kalman filter is discussed by cheng [10]. kalman filter is a very effective estimator for dynamics state estimation of complex systems, particularly linear dynamic discrete systems involving process noise and measurement noise. implementation of phidget spatial 3/3/3 [9] has been discussed by agarwal [11] and andersson [12], but they did not mention sensor performance issues in detail. this paper provides two important things. the first is description of a simple and systematic attitude computation model so that it can be used directly to calculate absolute attitude and relative attitude as an input for controlling joint angles of a pan-tilt mechanism. relation of coordinate systems between the pan-tilt mechanism and attitude rpy/beh is shown in figure 2 [1]. the second is explanation of application of imu phidget spatial 3/3/3 by creating its own software using matlab™ which works in realtime manner. ii. modeling a. sensor model model of angular rate, acceleration, and flux is used to obtain estimated value of relative attitude (roll, pitch, and yaw/rpy), absolute attitude (bank, elevation, and heading/beh), position and velocity. angular rate is modeled as follows: 𝜔𝜔 = 𝜔𝜔𝑔𝑔 − 𝑏𝑏𝑔𝑔 − 𝑛𝑛𝑔𝑔 (1) where 𝜔𝜔𝑔𝑔 is angular rate from gyroscope, 𝑏𝑏𝑔𝑔 is the gyroscope bias, 𝑛𝑛𝑔𝑔 is noise from the gyroscope measurement. acceleration is modeled as follows: 𝑎𝑎 = 𝑎𝑎𝑎𝑎 − 𝑛𝑛𝑎𝑎 (2) where 𝑎𝑎𝑎𝑎 is acceleration, 𝑛𝑛𝑎𝑎 is noise from the accelerometer measurement. flux is modeled as follows: 𝑚𝑚 = 𝑚𝑚𝑚𝑚 − 𝑖𝑖𝑚𝑚 − 𝑛𝑛𝑚𝑚 (3) where 𝑚𝑚𝑚𝑚 is the magnetic field vector derived from the magnetometer, 𝑖𝑖𝑚𝑚 is the magnetic field vector caused by vehicles interference, and 𝑛𝑛𝑚𝑚 is the noise of the magnetometer measurement. based on the three models of the sensor, the noise (𝑛𝑛𝑔𝑔,𝑛𝑛𝑎𝑎 , and 𝑛𝑛𝑚𝑚 ) can be minimized by the use of a kalman filter, the bias (𝑏𝑏𝑔𝑔) can be eliminated by static calibration process, while interference (𝑖𝑖𝑚𝑚 ) can be considered as zero if it is assumed that the magnetometer is isolated from vector magnetic field generated by the vehicle. b. ahrs model ahrs is a combination of three separate models derived through geometrical approach of the measurement sensors (gyroscope, accelerometer, and magnetometer) as shown in figure 3. in the figure, it can be seen that the ahrs is broken down into three models: (1) the model of relative attitude consisting roll, pitch, and yaw (rpy) angles from the gyroscope, (2) the model of absolute attitude which consists of bank, elevation, and heading (beh) angles from the accelerometer and magnetometer, and (3) the model of linear position and linear velocity from the accelerometer. it should be noted that prior to derivation of the three models described above, the difference between the sensor coordinate and global reference should be adjusted as shown in figure 4. notation of the two coordinates are adjusted to obtain 𝑋𝑋𝑟𝑟 = 𝑋𝑋, 𝑌𝑌𝑟𝑟 = 𝑍𝑍, and 𝑍𝑍𝑟𝑟 = −𝑌𝑌. figure 1. ins components figure 2. relation of coordinate systems h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 43 1) relative attitude model from gyroscope data the relative attitude model was set up to obtain the roll, pitch, and yaw (rpy) angles. gyroscope sensor output (𝜔𝜔) gives a value that states the amount of angular velocity. angle (𝜃𝜃) of the sensor output can be calculated by integration. the relationship between angular rate and angle signals are given below: 𝜃𝜃(𝑡𝑡) = ∫ 𝜔𝜔(𝑡𝑡) 𝑡𝑡𝑘𝑘 𝑡𝑡𝑘𝑘−1 𝑑𝑑𝑡𝑡 (4) 𝑑𝑑𝜃𝜃 (𝑡𝑡) 𝑑𝑑𝑡𝑡 = 𝜔𝜔(𝑡𝑡) (5) in discrete form, the above equation can be written as follows: 𝜃𝜃𝑘𝑘 +1−𝜃𝜃𝑘𝑘 ∆𝑇𝑇 = 𝜔𝜔𝑘𝑘 (6) 𝜃𝜃𝑘𝑘+1 = 𝜃𝜃𝑘𝑘 + 𝜔𝜔𝑘𝑘∆𝑇𝑇 (7) where 𝜃𝜃𝑘𝑘 is the current time angle, 𝜃𝜃𝑘𝑘+1 is calculated angle, 𝜔𝜔𝑘𝑘 is angular rate (gyroscope data), and ∆𝑇𝑇 is the current time 𝑡𝑡𝑘𝑘 minus the previous time 𝑡𝑡𝑘𝑘−1. 2) absolute attitude model from accelerometer and magnetometer data the absolute attitude model was derived to obtain bank, elevation, and heading angles [13]. the angles formed by rotation along x-axis and y-axis were calculated from the accelerometer data by assumption that z'≈ 1 as shown in figure 5. if z coordinates of the sensors is turned up the speed on z-axis will become negative (az<0) so that α and γ turn to negative. rotation matrix formed by the euler angles can be calculated by substitution of α and γ, where α = sin-1(ax) and γ = sin-1(ay). assuming that the magnetometer faces north or bearing (β= 0) then the following equation can be derived. r = � 𝑐𝑐(𝛼𝛼) −𝑠𝑠(𝛼𝛼) 𝑐𝑐(𝛾𝛾) 𝑠𝑠(𝛼𝛼) 𝑠𝑠(𝛾𝛾) 𝑠𝑠(𝛼𝛼) 𝑐𝑐(𝛼𝛼) 𝑐𝑐(𝛾𝛾) −𝑐𝑐(𝛼𝛼) 𝑠𝑠(𝛾𝛾) 0 𝑠𝑠(𝛾𝛾) 𝑐𝑐(𝛾𝛾) � (8) in the implementation, acceleration [ax, ay, az] and flux [mx, my, mz] should be normalized to ensure that the resulted vector is worth one. they are normalized as follows: 𝐴𝐴𝑥𝑥 = 𝑎𝑎𝑥𝑥 𝑎𝑎 ; 𝐴𝐴𝑦𝑦 = 𝑎𝑎𝑦𝑦 𝑎𝑎 ;𝐴𝐴𝑧𝑧 = 𝑎𝑎𝑧𝑧 𝑎𝑎 (9) 𝑀𝑀𝑥𝑥 = 𝑚𝑚𝑥𝑥 𝑚𝑚 ; 𝑀𝑀𝑦𝑦 = 𝑚𝑚𝑦𝑦 𝑚𝑚 ;𝑀𝑀𝑧𝑧 = 𝑚𝑚𝑧𝑧 𝑚𝑚 (10) where 𝑎𝑎 = �𝑎𝑎𝑥𝑥2 + 𝑎𝑎𝑦𝑦2 + 𝑎𝑎𝑧𝑧2 ; 𝑚𝑚 = �𝑚𝑚𝑥𝑥2 + 𝑚𝑚𝑦𝑦2 + 𝑚𝑚𝑧𝑧2 by adjusting the magnetic field coordinates from sensor to coordinates as shown in figure 4 then mfx=mx, mfy=mz, and mfz=–my. in vector form, they are expressed as below: 𝑚𝑚𝑣𝑣𝑣𝑣𝑘𝑘 = [𝑚𝑚𝑓𝑓𝑥𝑥 𝑚𝑚𝑓𝑓𝑦𝑦 𝑚𝑚𝑓𝑓𝑧𝑧 ] (11) the magnetic field vector in the above equation is then transformed to eliminate the influence of rotation that occurs through the following equation: 𝑉𝑉𝑚𝑚 = 𝑚𝑚𝑣𝑣𝑣𝑣𝑘𝑘 𝑅𝑅 = [𝑋𝑋𝑟𝑟 𝑌𝑌𝑟𝑟 𝑍𝑍𝑟𝑟 ] (12) where: 𝑋𝑋𝑟𝑟 = 𝑚𝑚𝑓𝑓𝑥𝑥 𝑐𝑐(𝛼𝛼) + 𝑚𝑚𝑓𝑓𝑦𝑦 𝑠𝑠(𝛼𝛼) (13) 𝑌𝑌𝑟𝑟 = −𝑚𝑚𝑓𝑓𝑥𝑥 𝑠𝑠(𝛼𝛼) 𝑐𝑐(𝛾𝛾) + 𝑚𝑚𝑓𝑓𝑦𝑦 𝑐𝑐(𝛼𝛼) 𝑐𝑐(𝛾𝛾) + 𝑚𝑚𝑓𝑓𝑧𝑧 𝑠𝑠(𝛾𝛾) (14) 𝑍𝑍𝑟𝑟 = 𝑚𝑚𝑓𝑓𝑥𝑥 𝑠𝑠(𝛼𝛼) 𝑠𝑠(𝛾𝛾) − 𝑚𝑚𝑓𝑓𝑦𝑦 𝑐𝑐(𝛼𝛼) 𝑠𝑠(𝛾𝛾) + 𝑚𝑚𝑓𝑓𝑧𝑧 𝑐𝑐(𝛾𝛾) (15) figure 3. ahrs modelling principle figure 4. equalization of global reference coordinates with the sensor coordinate h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 44 the above equation describes components of x and y at global reference coordinates that are rotated along x-axis and along z-axis as shown in figure 6. if the coordinates are adjusted back to the global reference coordinate we obtain xh = –zr, yh = –xr, and zh = yr. on this basis, xh and yh are given by the following equations: 𝑋𝑋ℎ = −𝑚𝑚𝑥𝑥 𝑠𝑠(𝛼𝛼) 𝑠𝑠(𝛾𝛾) + 𝑚𝑚𝑦𝑦 𝑐𝑐(𝛼𝛼) 𝑠𝑠(𝛾𝛾) − 𝑚𝑚𝑧𝑧 𝑐𝑐(𝛾𝛾) (16) 𝑌𝑌ℎ = −𝑚𝑚𝑥𝑥 𝑐𝑐(𝛼𝛼) − 𝑚𝑚𝑦𝑦 𝑠𝑠(𝛼𝛼) (17) xh and yh components in the above equation are used to calculate the north or bearing (β) of the coordinates of the earth as shown in figure 7. xh and yh are calculated using arctan so the quadrant of the two components must be considered. the two components are subject to provision shown in table 1. at the time zh coordinate changes in the opposite direction on z–axis, acceleration will be negative (az<0). in this case, β is the absolute value of (β–2π). all stages, the value that has been obtained are converted into a unit of degrees as the following equation: heading, 𝛽𝛽𝑘𝑘 = 𝛽𝛽 � 180 𝜋𝜋 � (18) elevation, 𝛼𝛼𝑘𝑘 = 𝛼𝛼� 180 𝜋𝜋 � (19) bank, 𝛾𝛾𝑘𝑘 = 𝛾𝛾 � 180 𝜋𝜋 � (20) 3) the position and velocity model from accelerometer data linear velocity is derived through integration process of acceleration data that can be written as follows: 𝑉𝑉�⃗ = ∫�𝐴𝐴�𝑑𝑑𝑡𝑡 (21) where a��⃗ is the acceleration vector (ax, ay, az) after normalization. the position is obtained by double integration of the acceleration data. s�⃗ = ∫�∫�a��⃗ � dt� dt (22) before performing the integral, the acceleration coordinate must be adjusted to the sensor coordinates as figure 4. in addition, the acceleration must be transformed in order to remain on the field of play in a horizontal plane (a) (b) figure 5. rotation of coordinate: (a) y-axis; (b) x-axis table 1. quadrant rules for xh and yh components [8] condition absolute value (𝜷𝜷) (xh< 0) 𝜋𝜋 − 𝑡𝑡𝑎𝑎𝑛𝑛−1 � 𝑌𝑌ℎ 𝑋𝑋ℎ � (xh> 0 & yh< 0) −𝑡𝑡𝑎𝑎𝑛𝑛−1 � 𝑌𝑌ℎ 𝑋𝑋ℎ � (xh> 0 & yh> 0) 2𝜋𝜋 − 𝑡𝑡𝑎𝑎𝑛𝑛−1 � 𝑌𝑌ℎ 𝑋𝑋ℎ � (xh = 0 & yh< 0) 𝜋𝜋/2 (xh = 0 & yh> 0) 3𝜋𝜋/2 figure 6. changes in the global reference coordinate figure 7. coordinate of xh and yh components h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 45 through the process of multiplying the acceleration data with rotation matrix as follows: 𝐴𝐴 = [𝐴𝐴𝑥𝑥 𝐴𝐴𝑦𝑦 𝐴𝐴𝑧𝑧]. 𝑅𝑅 = [𝐴𝐴𝑥𝑥2 𝐴𝐴𝑦𝑦2 𝐴𝐴𝑧𝑧2 ] (23) where: 𝐴𝐴𝑥𝑥2 = 𝐴𝐴𝑥𝑥 𝑐𝑐(𝛼𝛼) + 𝐴𝐴𝑦𝑦 𝑠𝑠(𝛼𝛼) (24) 𝐴𝐴𝑦𝑦2 = −𝐴𝐴𝑥𝑥 𝑠𝑠(𝛼𝛼) 𝑐𝑐(𝛾𝛾) + 𝐴𝐴𝑦𝑦 𝑐𝑐(𝛼𝛼) 𝑐𝑐(𝛾𝛾) + 𝐴𝐴𝑧𝑧 𝑠𝑠(𝛾𝛾) (25) 𝐴𝐴𝑧𝑧2 = 𝐴𝐴𝑥𝑥 𝑠𝑠(𝛼𝛼) 𝑠𝑠(𝛾𝛾) − 𝐴𝐴𝑦𝑦 𝑐𝑐(𝛼𝛼) 𝑠𝑠(𝛾𝛾) + 𝐴𝐴𝑧𝑧 𝑐𝑐(𝛾𝛾) (26) iii. hardware and software the complete structure of pan-tilt mechanism control system is shown in figure 8. in this section, the hardware is presented focusing only on imu sensor, while the software described is only associated with data reading. a. hardware the imu sensor used in this research is phidget spatial 3/3/3 [9]. it consists of a combination of three sensors, those are: 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer. the electronic component of the sensor physically consists of several integrated circuits (ics) collected in one electronic module as shown in figure 9. specifications of the sensor are listed in table 2. b. software in this paper a software has been developed using matlab™ to read measurement data from sensor phidget spatial 3/3/3. figure 10 shows the flowchart of the software. appropriate sampling time was determined by trial and error through experiment. figure 11 depicts effect of sampling time on the magnetometer sensor (z-axis). figure 11(a) shows an example that sampling time less than 32 ms (e.g. 16 ms) caused mall-function of the magnetometer sensor reading. figure 11(b) shows experiment result using sampling time of 32ms. experiment result using sampling time above 32 ms demonstrate to some extent the similar results. therefore, in this paper 32 ms is selected as the sampling time. the hardware connection greatly influences the program operation; therefore correct understanding of phidget library is necessary. the software reads data from the sensor and displays some information including: the three figure 9. top view of phidget spatial 3/3/3 sensor figure 8. pan-tilt mechanism control system h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 46 sensors measurement data, and calculation results of both models. output of model 3 (velocity and position) is ignored because it is useless for the pan-tilt mechanism to compensate the disruption of the platform. iv. experiment and analysis a. sensor data measurement the measurements were conducted by adjusting the sensor at stop position (kept in a state of rest). figure 12 shows the results of the reading of the accelerometer, gyroscope, and magnetometer sensors. the signals in the figure show that the raw data obtained from the sensor contains noise. the detail of noise reduction will be discussed in the next section. the most common noise in the imu sensor is in the form of white noise [9], so that it can be analyzed using standard deviation and average value. table 3 shows the analysis result. standard deviation value of the accelerometer and magnetometer sensor is smaller than the gyroscope sensor. b. attitude computation using kalman filter a kalman filter was designed through computer simulation using matlab. the kalman filter is used to minimize the noise effect. figure 13 shows an illustration of a kalman filter formulation. the detail formula was described by welch and bishop [14]. the measurement noise covariance (r) was obtained from the direct measurement when the sensor was positioned stationary (not moving). in this paper, r is the square of the standard deviation values of the measurement noise (r). the presented data in this section is the table 2. specifications of phidget spatial 3/3/3 [9] characteristics value gyroscope measurement max ±400 °/s resolution 0,02 °/s drift 4°/m compass measurement max ± 4 gauss resolution 400µg offset from north 2° accelerometer measurement max ±5g (49m/s2) resolution 228µg error through rotation 2mg bandwidth 110 hz axis 0 noise level (x-axis) 300µg axis 1 noise level (y-axis) 300µg axis 2 noise level (z-axis) 500µg board sampling speed 4ms– 1000ms usb voltage 4,75 – 5,25 vdc current consumption max 45ma usb speed full speed (12mbit) operating temperature 0 70°c figure 10. phidget spatial 3/3/3 software flowchart (a) (b) figure 11. effect of sampling time on the magnetometer sensor data (z-axis): (a) sampling time 16 ms; (b) sampling time 32 ms h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 47 gyroscope sensor data that has been stored in the form of text. it was selected for kalman filter design due to the larger standard deviation than the accelerometer and magnetometer as shown in table 3. the parameters set in the simulation are standard deviation values of the process noise (q) and the measurement noise (r). the selected noise measurement value was 0.08º/s. the estimated standard deviation of the process noise (q) is used to obtain the value of the process noise covariance (q). the q value was set half of standard deviation of the measurement noise(r). the combination of parameters for the simulation can be seen in table 4 and table 5. the simulation results of the three parameter combinations are shown in figure 14. it can be seen that the greater the value of q the better the kalman filter estimates the actual movement, while the smaller the value of q the worst the kalman filter estimate the actual movement. in contrast to the variation in the value of q, the value of r indicates that the smaller value of r makes the kalman filter estimate the better actual movement, while the greater the value of r makes the kalman filter estimate the worse actual movement. it can be seen that figure 14(c) shows the better performance compared to figure 14(a) and figure 14(b). based on these results the ideal ratio between the deviation of the measurement noise (r) and the deviation of process noise (q) is about 1:5 (r = 0.08 and q = 0.4) or (r = 0.008 and q = 0.04). based on this result, in this paper r = 0.08 and q = 0.4 are chosen. figure 15 and figure 16 show the results of measurements of the relative attitude and absolute attitude calculation. sensor data used to generate the attitude has been filtered through the kalman filter. noise in gyroscope sensor affects the results of integration, so that the calculated rpy angles accumulate error and continuously drift, when the sensor is in a state of rest. figure 13. operation of a kalman filter [14] (a) (b) (c) figure 12. measurement of x-axis: (a) gyroscope; (b) accelerometer; (c) magnetometer 0 10 20 30 40 50 60 -0.4 -0.2 0 0.2 0.4 gyroscope x-axis time (second) a ng ul ar ra te (o /s ) stddev = 0.0881 mean = -0.0104 0 10 20 30 40 50 60 -0.055 -0.054 -0.053 -0.052 -0.051 accelerometer x-axis time (second) a cc el er at io n( g) stddev = 0.0003 mean = -0.0538 ( ) 0 10 20 30 40 50 60 -0.82 -0.818 -0.816 -0.814 -0.812 magnetometer x-axis time (second) fl ux (g ) stddev = 0.0006 mean = -0.8170 table 3. standard deviation and average value of the sensor data measurements sensor x axis y axis z axis gyroscope (°/s) mean -0.0104 0.0042 -0.0054 standard deviation 0.0881 0.0880 0.0741 accelerometer (g) mean -0.0538 0.0126 0.9985 standard deviation 0.0003 0.0003 0.0000 magnetometer (g) mean -0.8170 -0.1382 0.5598 standard deviation 0.0006 0.0010 0.0009 h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 48 the drift can be observed in table 6. drift accumulation was successfully minimized by the kalman filter algorithm. the drift in the table (roll = 0.6º/min, pitch = 0.2º/min, and yaw = 0.3º/min) is smaller than the original specification from the manufacturer, 4º/min in average, as shown in the specifications for gyroscope sensors in table 2. the noise analysis result of the calculated absolute attitude shown in figure 16 is listed in table 7. the absolute attitude in table 7 has small standard deviation values. thus, it can be said that the model 2 which calculates the absolute attitude using measurement data from the accelerometer and magnetometer works well. c. imu sensor implementation the modelled and designed imu sensor has been tested on a crane. figure 17 shows the application of the imu on a crane. desired information from the measurements data was to determine the extent of horizontal rotation (pan) of the crane. as the crane worked according to sequence in table 8, the data generated by the (a) (b) (c) figure 14. optimization of the angular rate when the sensor is not actuated 0 50 100 150 200 250 300 350 400 0 0.2 0.4 0.6 0.8 data-i an gu la r r at e (o / s) q type no.1 & r type no.3 without kalman with kalman 0 50 100 150 200 250 300 350 400 0 0.2 0.4 0.6 0.8 data-i an gu la r r at e (o / s) q type no.2 & r type no.2 without kalman with kalman 0 50 100 150 200 250 300 350 400 0 0.2 0.4 0.6 0.8 data-i an gu la r r at e (o / s) q type no.3 & r type no.1 without kalman with kalman table 8. crane working sequence time events 14:42 crane was lifting a motor wire moving from west to north 14:44 crane was placing the motor wire at north 14:49 crane was lifting a box moving from west to north 14:52 crane was placing the box at north 14:54 crane was lifting a generator moving from north to south east 14:58 crane was lifting the generator higher at south east 15:01 crane was placing the generator at north 15:02 crane was rotating from north to south east, then to north 15:07 crane was lifting two small drums from north to west 15:09 crane was placing the drums at west 15:13 crane was placing the boom to boom rest 15:14 crane was lifting the boom from boom rest 15:16 crane was lifting a motor from north to north west 15:16 crane was placing the motor at north west 15:18 crane was placing the boom to boom rest table 4. variations of the process noise (q) no combination ofq process noise (q) measurement noise (r) 1 q/10 0.004 0.08 2 q (estimation) 0.04 0.08 3 q*10 0.4 0.08 table 5. variations of the measurement noise (r) no combination of r process noise (q) measurement noise (r) 1 r/10 0.04 0.008 2 r (estimation) 0.04 0.08 3 r*10 0.04 0.8 table 6. drift of relative attitude value rpy angle slope (°) drift (°/min) initial value final value roll 0 -0.5959 0.6 pitch 0 0.2410 0.2 yaw 0 0.3459 0.3 table 7. standard deviation and mean value of the calculated absolute attitude beh angle mean (°) standard deviation (°) bank 0.7224 0.0066 elevation 3.0845 0.0075 heading -98.8103 0.0460 h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 49 imu sensor was recorded. angle values obtained in this trial do not exactly represent the actual values because were not measured with a calibrated comparison tool. this test was only to find out the sensor ability in open environment application. the data generated in this trial can be seen in figure 18. the figure shows that in general the developed imu sensor can work well and can be used to measure the horizontal angle of the crane movement. the data possessed ‘jump’ which may be caused by metal interference and the rigidity of the crane itself. (a) (b) (c) figure 15. calculated relative attitude: (a) x-axis; (b) y-axis; and (c) the z-axis \ (a) (b) (c) figure 16. calculated absolute attitude: (a) x-axis;(b) y-axis; and (c) the z-axis figure 17. imu sensor implementation on a crane h. m. saputra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 41-50 50 v. conclusions from the results of this research the following conclusions can be drawn. the modelling and design of the imu sensor derived in this research could be implemented on the sensor phidget spatial 3/3/3 to obtain position, velocity, and attitude of an object. the standard deviation of error that occurs in the gyroscope sensor at the x axis is ± 0.0881°, in the accelerometer at the x axis is ± 0.0003 g, and in the magnetometer at the x axis is ± 0.0006 g. in this research, through simulation and experiment, the following appropriate values are obtained: (a) sampling time should not be less than 32 ms; (b) comparison between the measurement noise (r) and the process noise (q) for the parameters of the kalman filters is 1 : 5 with r = 0.08 and q = 0.4. references [1] h. m. saputra, et al., "analysis of inverse angle method for controlling two degree of freedom manipulator," journal of mechatronics, electrical power, and vehicular technology, vol. 03, pp. 9-16, 2012. [2] d. h. titterton and j. l. weston, strapdown inertial navigation technology, second ed.: united kingdom: the institution of electrical engineers, 2004. [3] w. adiprawita, et al., "development of ahrs for autonomous uav," in proceedings of international conference on electrical engineering and informatics, institut teknologi bandung, indonesia 2007, pp. 714-717. [4] k. waller, "developing a benchmark suite for the evaluation of orientation sensors," msc. thesis, clemson university, 2006. [5] j. j. craig, introduction to robotics: mechanics and control, third ed.: pearson education, inc., 2005. [6] n. h. q. phuong, et al., "a dcm based orientation estimation algorithm with an inertial measurement unit and a magnetic compass," journal of universal computer science, vol. 15, pp. 859-876, 2009. [7] a. budiyono, et al., "the application of mems-based inertial sensors for onboard avionics system of unmanned aerial vehicles," presented at the 5 th international symposium on nanomanufacturing, 2008. [8] m. j. caruso, "applications of magnetic sensors for low cost compass systems," presented at the position location and navigation symposium, san diego, 2000. [9] i. phidgets. (2012, 25 sept). 1056 phidgetspatial 3/3/3. available: http://www.phidgets.com/products.php?p roduct_id=1056 [10] l. cheng, et al., "attitude determination for mavs using a kalman filter," tsinghua science and technology, vol. 13, pp. 593-597, 2009. [11] p. k. agarwal, "real-time data acquisition, transmission and archival framework," master of science, department of computer engineering, rochester institute of technology, rochester, new york, 2011. [12] t. andersson and m. idegren, "set-up and real-traffic assessment of a data logger for vulnerable-road-user motion," master’s thesis, department of applied mechanics, chalmers university of technology, g¨oteborg, sweden, 2011. [13] i. phidgets, "1056 phidgetspatial 3/3/3, code samples for this product, 2010," ed, 2010. [14] g. welch and g. bishop, "an introduction to the kalman filter," university of north carolina at chapel hill, technical report, tr 95-041, 2006. figure 18. measurements of horizontal crane angle relative attitude model from gyroscope data absolute attitude model from accelerometer and magnetometer data the position and velocity model from accelerometer data hardware software conclusions mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 04, issue 2, december 2013 aim and scope mechatronics, electrical power, and vehicular technology (mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, tubine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev journal vision is to become international journal with high scientific contribution for global community. mev journal mission is presenting important results of work, whether in the form of research, development, application, or design. editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h1034, hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia za@dynamic.pauir.itb.ac.id prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2 nd fl, bandung 40135, ndonesia budi.prawara@lipi.go.id advisory editor ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id mailto:patko@uni-obuda.hu journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 04, issue 2, december 2013 imprint journal of mechatronics, electrical power, and vehicular technology (mev) is published by research center for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). mev journal is managed to be issued twice in every volume. for every edition, the online edition is published earlier than the print edition. issn print edition: 2087-3379 issn electronics edition: 2088-6985 electronics edition is available at: www.mevjournal.com accreditation accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 mev has been certificated as national scientific journal by indonesian institute of sciences (lipi) by 24 april 2012. valid thru: 24 april 2015 indexing & abstracting indexed in directory of open access journal (doaj), google scholar, indonesian scientific journal database (isjd), indonesian publication index (ipi), crossref, mendeley, citeulike, academic journal database, researchbib, cite factor. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2 nd floor bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 managing editors aam muharam, m.t. electrical engineering aam.muharam@yahoo.com dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com section editors ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com arini wresta, m.eng. chemical engineering awresta@gmail.com yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id dian andriani, m.eng. bioenergy engineering dea1401@yahoo.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com vita susanti, s.kom. computer science vitasusanti@gmail.com secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com layout editors rakhmad i pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com hendri m saputra, m.t. robotics and mechatronics hendri_maja@yahoo.co.id arief a firdaus, s.i.kom. communication science rif212@yahoo.com proofreaders naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com achmad praptijanto, m.eng. mechanical engineering cak.yanto@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com subscription managers noviadi a rachman, m.t. electrical engineering n.ariefrachman@gmail.com vita susanti, s.kom. computer science vitasusanti@gmail.com graphic designer m redho kurnia, s.sn. graphic design muha058@lipi.go.id http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 © 2013 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 04, issue 2, december 2013 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has been accreditated by the indonesian institute of sciences (lipi) in april 2012. it started using open journal system (ojs) since the online publishing of the third volume released in july 2012. this journal has been indexed by google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib, and cite factor. in addition, it has been granted digital object identifier with the doi prefix 10.14203. this issue publishes eight papers, all are written in english, with the total number of paper pages of 70 pages. the selected papers in this issue have passed some levels of reviews and revisions based on the standard operating procedure of the journal. four topics are related to mechatronics, three topics to electrical power and one topic to vehicular technology. most of the papers reflect one of the characteristics of this journal i.e. interdisciplinary. in the paper concerning nano-fiber fabrication, for example, the authors who have different backgrounds of expertise tackle a focused issue in a multidisciplinary approach. the policy up to this current issue is that both authors and readers are not charged at all. on the other hand, the editorial board is planning to improve the quality by registering the journal to other international academic citation index. moreover, the editorial board is also considering to gradually increase the number of papers and journal’s pages. all of this plan will give consequence on financial burden. therefore, from the next issue, financial policy will probably change based on that condition. we wish to offer our thanks to all the editorial members and the research center for electrical power and mechatronics (rc-epm) – indonesian institute of sciences (lipi) for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2013 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 04, issue 2, december 2013 list of contents design and development of a control system for nanofiber electrospinning dayat kurniawan, purwoko adhi, muhammad nasir 65-74 design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter moh. zaenal efendi, novie ayub windarko, m. faisal amir 75-80 the performance of eeg-p300 classification using backpropagation neural networks arjon turnip, demi soetraprawata 81-88 economic analysis of cikaso mini hydro power plant as a cdm project for increasing irr irhan febijanto 89-98 object recognition system in remote controlled weapon station using sift and surf methods midriem mirdanies, ary setijadi prihatmanto, estiko rijanto 99-108 control of pan-tilt mechanism angle using position matrix method hendri maja saputra, arif santoso, midriem mirdanies, vikita windarwati, riastus nayanti, lukni maulana 109-116 combustion property analysis and control system for the dynamics of a single cylinder diesel engine bambang wahono, wang xiaoli, harutoshi ogai 117-126 mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car seno aji, dwi ajiatmo, imam robandi, heri suryoatmojo 127-134 further articles can be found at www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 04, issue 2, december 2013 abstracts sheet e-issn: 2088-6985 date of issues: 24 december 2013 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. dayat kurniawan a , purwoko adhi a , muhammad nasir b ( a research center for electronics and telecommunication, indonesian institute of sciences, bandung, b research center for chemical, indonesian institute of sciences, bandung) design and development of a control system fornanofiber electrospinning mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2,p. 65-74, 16 ill, 4tab, 15 ref. this paper describes the development of a control hardware and software for a nano-fiber electro-spinning system. thehardware consists of motor driver boards, a high dc voltage board, and a main control board. the user interface software on pcis developed using visual studio c # 2010 express edition. the motor driver boards are controlled by an atmega8microcontroller ic, while the main board is controlled by an atmega 128 microcontroller ic. communication between the mainboard and the motor driver boards uses the inter integrated circuit (i2c), while communication between pc and the main boarduses a serial communication at a baud rate of 9600 bps. the high dc voltage generator is designed to have an output of 0-25 kv.high dc voltage output is configurable by giving a combination of low logic and high impedance into a six bit input. the resultshow that maximum output of high dc voltage is 25.025 kv with formula of curve is y = 1x-0.0244 with r2=0.9998 and pcsoftware interface can work very well. polymer flow rate can be configured from pc interface software via i2c connected to themain board. the flow rate y follows the rpm setting x, according to the formula y = 0.954x – 0.0099 with r2 = 1. the results ofscanning electron microscope (sem) for morphology analysis of pvdf copolymer composite nano-fiber shows that the averagediameter of the resulted fiber is 136.43 nm, when output high dc voltage is set to 15 kv and speed of syringe pump is set to 5rpm.. (author) keywords: electrospinning, high dc voltage, i2c, motor driver, microcontroller, pc interfacesoftware. moh. zaenal efendi a , novie ayub windarko a , m. faisal amir a ( a department of electrical engineering, politeknik elektronika negeri surabaya, surabaya) design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 75-80, 11 ill, 3tab, 12 ref. this paper presents a design and implementation of a converter which has a high power factor for battery charger application. the converter is a combination of a sepic converter and a full-bridge dc-dc converter connected in two stages of series circuit. the sepic converter works in discontinuous conduction mode and it serves as a power factor corrector so that the shape of input current waveform follows the shape of input voltage waveform. the fullbridge dc-dc converter serves as a regulator of output voltage and operates at continuous conduction mode. the experimental results show that the power factor of this converter system can be achieved up to 0.96. (author) key words: sepic converter,full-bridgedc-dc converter, discontinuous conduction mode, power factor correction, battery charger. demi soetraprawata, arjon turnip(technical implementation unit for instrumentation development division – lipi, bandung) the performance of eeg-p300 classification using backpropagation neural networks mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 81-88, 4 ill, 4tab, 22 ref. electroencephalogram (eeg) recordings signal provide an important function of brain-computer communication, but the accuracy of their classification is very limited in unforeseeable signal variations relating to artifacts. in this paper, we propose aclassification method entailing time-series eeg-p300 signals using backpropagation neural networks to predict the qualitative properties of a subject’s mental tasks by extracting useful information from the highly multivariate non-invasive recordings ofbrain activity. to test the improvement in the eeg-p300 classification performance (i.e., classification accuracy and transferrate) with the proposed method, comparative experiments were conducted using bayesian linear discriminant analysis (blda).finally, the result of the experiment showed that the average of the classification accuracy was 97% and the maximum improvement of the average transfer rate is 42.4%, indicating the considerable potential of the using of eeg-p300 for the continuous classification of mental tasks. (author) keywords: eeg-p300 classification, backpropagation neural networks, blda, accuracy, transfer rate. irhanfebijanto a ( a centre for technology of energy resources development, deputy for technology of informatic, energy and mineralbppt, serpong) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv economic analysis of cikaso mini hydro power plant as a cdm project for increasing irr mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 89-98, 4ill, 13tab, 17 ref. renewable energy fueled power generations are few developed by private sector in indonesia. high-cost investment and low electricity selling price to pt pln as a single buyer is main barriers for private sector to involve in the development of renewable energy fueled power generations. in this project, the economic feasibility of mini hydro power plant of cikaso with capacity of 5.3 mw, located at sukabumi regency, jawa barat province was assessed. this project utilized revenue generated from carbon market to increase the economic feasibility. procedure to register the project to united nation for climate change convention (unfccc) as a clean development mechanism project was explained in detail. approved consolidation methodology (acm) 0002 version 12.3.0 was used to calculate grid emission factor in jawa-bali – madura the grid electricity system. it was calculated that the grid emission factor is 0.833 (t-co2/mwh), and the carbon emission reduction generated for this project is 21,982 ton/year. from the analysis result, it can be proven that the additional revenue from carbon credit could increase the project irr from 10.28% to 13.52%. (author) keywords: mini hydro power plant, clean development mechanism, emission factor, irr. midriem mirdanies a , ary setijadi prihatmanto b , estiko rijanto a ( a research centre for electrical power & mechatronics, indonesian institute of sciences, bandung; b school of electrical engineering and informatics, bandung institute of technology (itb)) object recognition system in remote controlled weapon station using sift and surf methods mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 99-108, 17 ill, 4tab, 14 ref. object recognition system using computer vision that is implemented on remote controlled weapon station (rcws) is discussed. this system will make it easier to identify and shoot targeted object automatically. algorithm was created to recognizereal time multiple objects using two methods i.e. scale invariant feature transform (sift) and speeded up robust features (surf) combined with k-nearest neighbors (knn) and random sample consensus (ransac) for verification. the algorithm is designed to improve object detection to be more robust and to minimize the processing time required. objects are registered on the system consisting of the armoured personnel carrier, tanks, bus, sedan, big foot, and police jeep. in addition, object selection can use mouse to shoot another object that has not been registered on the system. kinect(™) isused to capture rgb images and to find the coordinates x, y, and z of the object. the programming language used is c with visual studio ide 2010 and opencv libraries. object recognition program is divided into three parts: 1) reading image from kinect(™) and simulation results, 2) object recognition process, and 3) transfer of the object data to the ballistic computer. communication between programs is performed using shared memory. the detected object data is sent to the ballistic computer via local area network (lan) using winsock for ballistic calculation, then the motor control system moves the direction of the weapon model to the desired object. the experimental results show that the sift method is more suitable because more accurate and faster than surf with the average processing time to detect one object is 430.2 ms, two object is 618.4 ms, three objects is 682.4 ms, and four objects is 756.2 ms. object recognition program is able to recognize multi-objects and the data of the identified object can be processed by the ballistic computer in realtime. (author) keywords: rcws, object recognition, shared memory, sift, surf, opencv, c language, kinect(™). hendri maja saputra a , arif santoso a , midriem mirdanies a ,vikita windarwati b , riastus nayanti b , lukni maulana b ( a research centre for electrical power and mechatronics, indonesian institute of sciences, bandung; b mechatronics department, faculty of engineering yogyakarta state university, yogyakarta) control of pan-tilt mechanism angle using position matrix method mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 109-116, 7 ill, 0tab, 10 ref. control of a pan-tilt mechanism (ptm) angle for the bomb disposal robot morolipi-v2 using inertial sensor measurement unit, x-imu, has been done. the ptm has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving morolipi-v2 platform. the x-imu detects the platform orientation and sends the result in order to automatically control the ptm. the orientation is calculated using the quaternion combined with madwick and mahony filtermethods. the orientation data that consists of angles of roll (α), pitch (β), and yaw (γ) from the x-imu are then being sent to the camera for controlling the ptm motion (pan & tilt angles) after calculating the reverse angle using position matrix method.experiment results using madwick and mahony methods show that the x-imu can be used to find the robot platform orientation. acceleration data from accelerometer andflux from magnetometer produce noise with standard deviation of 0.015g and 0.006g, respectively. maximum absolute errors caused by madgwick and mahony method with respect to x-axis are 48.45º and 33.91º, respectively. the x-imu implementation as inertia sensor to control the pan-tilt mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle. (author) keywords: pan-tilt control, x-imu sensor, quaternion, position matrix, morolipi-v2. bambangwahono a, , wang xiaoli b , harutoshiogai c ( a research centre for electrical power and mechatronics, indonesian institute of sciences, bandung; b foster electric. co., ltd, 512 miyazawacho, akishima city, tokyo, 196-8550, japan; c graduate school of information, production and systems, waseda university, 2-7 hibikino, wakamatsu-ku, kitakyushu, fukuoka 808-0135, japan) combustion property analysis and control system for the dynamics of a single cylinder diesel engine mechatronics, electrical power, and vehicular technology, december 2013, vol. 4, no. 2, p. 117-126, 10 ill, 3tab, 19 ref. corresponding to global environment problems in recent year, the technology for reducing fuel consumption and exhaust gas emission of engine was needed. simulation of transient engine response is needed to predict engine performance that frequently experience rapid changes of speed. the aim of this research is to develop a nonlinear dynamic control model for direct injection single cylinder diesel engine which can simulate engine performance under transient conditions. in this paper, the combustion model with multistage injection and conducted experiments in the transient conditions to clarify the combustion characteristics was proposed. in order to perform the analysis of acceleration operation characteristics, it was built a model predictive control (mpc) to reproduce the characteristic values of the exhaust gas and fuel consumption from the control parameters in particular. finally, mpc is an effective method to perform the analysis of characteristic in diesel engine under transient conditions. (author) keywords: model predictive control (mpc), transient, diesel engine, disturbance, modeling. seno aji a , dwi ajiatmo b , imam robandi a , heri suryoatmojo a ( a department of electrical engineering, institut teknologi sepuluh nopember (its), surabaya; b department of electrical engineering, universitas darul ulum jombang, jombang) mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car mechatronics, electrical power, and vehicular technology, journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 v december 2013, vol. 4, no. 2, p. 127-134, 13 ill, 5tab, 11 ref. this paper presents a control called maximum power point tracking (mppt) for photovoltaic (pv) system in a solar car. the main purpose of this system is to extracts pv power maximally while keeping small losses using a simple design of converter. working principle of mppt based fuzzy logic controller (mpptflc) is to get desirable values of reference current and voltage. mppt-flc compares them with the values of the pv's actual current and voltage to control duty cycle value. then the duty cycle value is used to adjust the angle of ignition switch (mosfet gate) on the boost converter. the proposed method was shown through simulation performed using psim and matlab software. simulation results show that the system is able to improve the pv power extraction efficiency significantly by approximately 98% of pv’s power. (author) keywords: maximum power point tracking (mppt), photovoltaic (pv), boost converter, fuzzy logic controller, solar car. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vi this page is left blank mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2014 rcepm lipi all rights reserved doi: 10.14203/j.mev.2014.v5.27-36 a trajectory generation method based on edge detection for auto-sealant cartesian robot eka samsul ma’arif a,b, *, endra pitowarno a , rusminto tjatur w a a electronic engineering polytechnic institute of surabaya jalan raya its sukolilo, surabaya 60111 b astra manufacturing polytechnic gaya motor raya no. 8, astra international, sunter, north jakarta received 7 november 2013; received in revised form 12 february 2014; accepted 16 february 2014 published online 23 july 2014 abstract this paper presents algorithm ingenerating trajectory for sealant process using captured image. cartesian robot as autosealant in manufacturing process has increased productivity, reduces human error and saves time. but, different sealant path in many engine models means not only different trajectory but also different program. therefore robot with detection ability to generate its own trajectory is needed. this paper describes best lighting technique in capturing image and applies edge detection in trajectory generation as the solution. the algorithm comprises image capturing, canny edge detection, integral projection in localizing outer most edge, scanning coordinates, and generating vector direction codes. the experiment results show that the best technique is diffuse lighting at 10 cd. the developed method gives connected point to point trajectory which forms seala nt path with a point to next point distance is equal to 90° motor rotation. directional movement for point to point trajectory is controlled by generated codes which are ready to be sent by serial communication to robot controller as instruction for motor s which actuate axes x and y directions. keywords: canny edge detection, integral projection, scanning the coordinate, vector direction code. i. introduction sealant process is one of production stages which has purpose to cover machine surface with adhesive liquid. specific surface is the edge of machine block that liquid prevents air exchangein machine space. it has been developed using cartesian robot that its movement programmed to follow the specific surface to be covered. a cartesian robot (also called linear robot) is an industrial robot whose three principal axes of control are linear (i.e. they move in a straight line rather than rotate) and are at right angles to each other[1]. high precision, low reject product and rapid process obtained by using it. but, large amount of machine models or new machine models cause new problem, a programmer has to do re-programming and re-calibration in change every models. so, we need fast adaptive and flexible robot for many models of machine. basically, every robot works with sequential processes that is defined by computer or controller trough codes, programming languages or pictures. common cartesian robots have a machine control unit (mcu) which inputs a numerical program to control the behavior and movements of all the parts of the machine. currently numerical programs interpreted by mcus are formed by an assembler-like code which is divided into single instructions called gcodes. another way is using geometric models, they are generated in a computer aided design (cad)-system and then exported to computer aided manufacturing (cam) software [2]. both codes and geometric models are offline conventional methods which require reprogramming in trajectory change. online or sensor based trajectory generation considers the motion of a system to be dependent on the sensor at the robot or movement pattern, which means that the motion is directly modified based on the new command in every iteration. pitowarno proposed an alternative scheme called knowledge-based trajectory error pattern method (kbtepm) to suppress the trajectory track error of the afc (active force control) scheme. the knowledge is developed from the * corresponding author. phone: +62-85691655860 e-mail: ekasamsul@student.eepis-its.edu http://dx.doi.org/10.14203/j.mev.2014.v5.27-36 e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 28 trajectory track error characteristic based on the previous experimental results of the crude approximation method. his method was success to control two-link robot arm [3]. a new approach is using captured image. images treated with image processing can generate information to give instruction as the robots trajectory. thus, computer vision becomes important in robotics and industries. takarics and szemes presented a new way to determine the trajectory for welding robots based on the intelligent space concept. the system uses two cameras and edge detection with other image processing algorithms to find the welding path in the image. it’s three dimensional position is obtained by stereo vision and then it is transformed to the robot language [4]. another online trajectory research was developed by bojan kuljic, he has developed autonomous mobile robot to find path in unknown indoor environment based on edge detection which combined with infra red distance as measuring sensor. 3d feature of environment was extracted using 2d image detection in determining object in front the robot. lines detected was considered as obstacle then measured distance by infra red, so robot can generate avoidance algorithm to find other path for its movement [5]. computer vision allows robot not only to determine environment but also to recognize specific object. an object recognizing system in remote control weapon station has been developed by midriem mirdanies. the research applies scale invariant feature transform (sift) and speeded up robust features (surf) to define the number of vehicle’s keypoint and descriptor, then stores it to database as registered object. the data from database was compared to capturing image from camera in real time object recognition. the name of captured object will be displayed if has suitable data with registered object [6]. this paper presents offline trajectory generation using captured image. previous researches above had proved that computer vision has essential part in trajectory generation and environment recognizing. the objective of this paper is to find edge of the machine then processes it to trajectory, so edge detection is used. edges in images are areas with strong intensity contrasts – a jump in intensity from one pixel to the next. several algorithms exist, different method work better under different condition and goal. this paper focuses on canny detection method because of the good performance and detail detected result [7]. beside, canny edge detector is widely considered to be the standard edge detection algorithm in the industry [8]. many publications have written about canny edge detection method, such as prof. prem kalra at his lecturer classroom who describes step by step of canny edge detection method clearly [9]. pixel coordinates from detected edge becomes main information for generating trajectory from one pixel point to another as axis movement of the cartesian robot. section ii explains about image preparation, capturing technique, and edge detection. canny edge detection is used to detect edge of machine block then it is localized from the background. the output of canny edge detection still contain various pixel of edge, so another algorithm needed go get only one specific edge. integral projection applied to detect outer edge boundary and get the outer most pixel. finally, edge is scanned in order to get the coordinates. section iii shows experiment result and data acquisition in generating accurate trajectory codes. section iv presents the research conclusion and further research. ii. methodology a. image preparation main step in image preparation is lighting technique. the quality and appropriateness of lighting are critical aspects for creating a robust vision inspection [10]. lighting techniques can be categorized as direct and diffuse lighting. both direct and diffuse are used in this research. dark background is needed to avoid reflection that becomes noise in image processing. lighting figure 1. direction lighting (a) top view, (b) side view figure 2. diffuse lighting (a) top view, (b) side view e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 29 which spread evenly is used to avoid shadow in machine block. lighting directions are shown in figure 1 and figure 2. figure 1 is direct lighting where 3 light sources are used directly to machine. figure 2 is diffuse lighting with object placed in diffuse area. both direct and diffuse are keep light spread evenly around the background and object to avoid shadow. light intensity at object is controlled and measured by a luxmeter. secondary step is capturing image. cartesian robot has main duty to do sealant process which its movement follows edge of machine accurately, therefore image must provide accurate information including absolute 2d projection and image scale. image scale has a role in dimensional ratio between image and real object. background has been marked to keep every captured image always has same size (l and w). l and w are length and width of real dimension respectively. l and w are length and width of scaled dimension respectively. so, 1 pixel in image represents certain millimeter in real dimension called ratio (r). 𝑟 = 𝐿 𝑙 (1) figure 3 shows how to capture machine block (object). background area represents real dimension (in mm) and image is scaled dimension (in pixel). a pocket camera canon ixus 220 hs is used to capture machine image with dimension 4:3 in long and width. captured image by the camera is stored as a red, green and blue (rgb) image. rgb image stores the value of each pixel in 3 channels but it could take too much time and consume too much memory for computer, therefore rgb image has to be converted to grayscale image. almost 90% of edge information in a color image can be found in the corresponding grayscale image [11]. b. canny edge detection the canny edge detection algorithm is known to many as the optimal edge detector. john f. canny was very successful in achieving his goal which his ideas and methods can be found in his paper, "a computational approach to edge detection". the aim was to develop an algorithm that is optimal to the following steps [9]: 1) smoothing using gaussian filter 2) finding gradients using sobel operator 3) non-maxima suppression to sharpen the edge 4) thresholding and edge tracking by hysteresis to separate between strong and weak edges. edge detection program was developed in microsoft visual studio 6.0 and open cv libraries. figure 4 shows steps of canny edge detection. blurred image as the result of gaussian filter kernel has purpose to reduce noise from input image. then sobel-operator and nonmaxima suppression are applied respectively in getting edge and sharpen it. image still contains figure 3. capturing technique figure 4. canny edge detection steps e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 30 various intensity of edge at this step. some may true edge but the rest is noise [12]. only strong edge with certain value will be kept by using double threshold. stronger edge than high threshold marked as strong edge, weaker edge than low threshold erased, then edge between high and low threshold assume as weak edge [13], [14]. so that strong edge can be isolated from weak edge then the final result of edge detection process is only image with strong edges. c. localize main edge final result from canny edge detection still contain a lot of edges, whereas only outer most edge needed. to localize the outer most edge integral projection function is applied. due to their simplicity and robustly, image integral projection functions have been used widely for the detection of the boundary between different image regions. among them, the vertical and horizontal integral projection functions are most popular. here, suppose i(x,y) is the intensity of a pixel at location (x,y), the vertical integral projection function ipfv(x) and horizontal integral projection function ipfh(y) of i(x,y) in intervals [y1, y2] and [x1,x2] can be defined respectively as: 𝐼𝑃𝐹𝑣 𝑥 = 𝐼(𝑥, 𝑦)𝑑𝑦 𝑦2 𝑦1 (2) 𝐼𝑃𝐹ℎ (𝑦) = 𝐼(𝑥, 𝑦)𝑑𝑥 𝑥2 𝑥1 (3) the above two functions are used to detect the boundary of different image regions in the vertical and horizontal directions. assuming pf is a projection function and ξ is a small constant. thus, if the value of pf rapidly changes from z0 to (z0+ ξ) , it indicates that z0 lie on the boundary between two homogeneous regions. using this approach, we can localize machine image from the background and detect the outer most side [15]. d. finding pixel coordinate the outer most edge obtained by applying integral projection. then, every pixel coordinate must be found in order to generate point to point direction. scanning process began by divides image frame into 4 quadrants [16], (figure 5). scanning algorithm described below : 1) scan quadrant ii by increasing x coordinate form left to right pixel and find y with direction from bottom to top, note every pixel found. 2) scan quadrant i by increasing x coordinate form left to right pixel and find y with direction from top to bottom, note every pixel found. 3) scan quadrant iv by decreasing x coordinate form right to left pixel and find y with direction from top to bottom, note every pixel found. 4) scan quadrant iii by decreasing x coordinate form right to left pixel and find y with direction from bottom to top, note every pixel found. figure 6 is pixel coordinates illustration. program will computer scanning algorithm start from most left pixel in ii quadrant to continue right pixel from top coordinate to bottom. according to figure 6, pixel coordinates list should be, 2,7 ; 3,6 ; 4,5 ; 4,4 ; 5,3 ; 6,3………………. ; 3,12 ; 3,11 ; 3,10 ; 2,9 ; 2,8. first pixel is initial point to begin and last pixel is end point of sealant process. pixel coordinate has difference with cartesian coordinate in y axis, so y axis has to be multiplied by -1 to equate perception. e. generating trajectory true edge pixels will always be associated with other edge pixels. so, initial pixel to next pixel always has 1 pixel difference (+1 or -1) in figure 5. scanning algorithm illustration figure 6. pixel coordinates illustration figure 7. vector direction code e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 31 vertical, horizontal or both of them. generating vector direction code uses dijkstra algorithm (shortest path). direction of displacement from initial pixel to next pixel determines the code, figure 7. program computes algorithm from initial pixel (1) to next pixel (2) by subtraction operation y1-y0 and x1-x0 in cartesian coordinate. possible result of both y1-y0 and x1-x0 are 1,-1 or 0, and explained to appropriate direction code in table 1. according to figure 6, vector direction code generated is 3, 3, 2, 3, 4, 4 ………………, 8, 2, 2, 1, 2, 2. directional codes will be saved then sent to motor controller. direction code is converted to motor x and y rotation as shown in table 2. iii. result and discussion a. lighting technique and edge detection capturing process has been done indoor in order to simplify lighting adjustment and light intensity was measured by luxmeter. l and w were always kept in 40 cm and 30 cm to get stable image scaling by adjusting distance from camera to the object (machine). captured images are stored at 320x240 pixels dimension, so every pixel of the image represents r =1.25 mm in real object. capturing set up was set as shown by figure 8. direct lighting and diffuse lighting were applied in capturing process with various intensity (i) in candela, start from 10 cd to 3,000 cd. low intensities among 10 cd to 400 cd was obtained from 50w tab lamp configuration and table 1. vector direction code logic δy= 1 δy= 0 δy= 1 δx= 1 1 4 7 δx= 0 2 0 6 δx= 1 3 8 5 table 2. vector direction code to dc motor rotation code motor x motor y 0 off off 1 reverse forward 2 off forward 3 forward forward 4 forward off 5 forward reverse 6 off reverse 7 reverse reverse 8 reverse off table 3. captured image in various intensity and lighting i (cd) light image edge 10 direct 10 diffuse 30 direct 30 diffuse 70 direct 70 diffuse 200 direct 200 diffuse 300 direct 300 diffuse 400 diffuse 800 diffuse 1,000 diffuse 3,000 diffuse e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 32 higher one was produced by 500 w halogen lamp. table 3 shows captured images and detection results in various intensities with two different lighting techniques. b. edge boundary and finding pixel coordinate the captured image with intensity of 10 cd and diffuse lighting is used to localize boundary in getting outer most edge shown in figure 9. figure above shows that outer most pixels are found successfully although contains some noise. then, scanning algorithm (figure 5) is applied to find pixel coordinates. pixel coordinate which found in scanning process is read in matlab as matrix, then multiplied with [1 -1] to get same orientation in plotting cartesian coordinate. plotted coordinate has main purpose to verify between scanning accuracy with real capturing object, figure 10. edge detected may contain noise called disperse pixel or jumping coordinate which y1-y0 and x1-x0 greater than 1 or less than -1 (marked in red), therefore filtering has to be applied. changes values of x form a point to next point are always 1, 0 or -1 because of increasing and decreasing scanning algorithm at figure 5, but not in y. jumping coordinate has drastic changes in y, figure 11. filter has been design to correct x and y when jumping pixel was happened. filter will replace x1 and y1 with xc and yc (pixel connector to next pixel) as shown in figure 12 [17]. pixel connector for (x0,y0) to (x2,y2) : if x2 – x0 = 2, or x2 – x0 = 1, then xc = (x0 + 1) if x2 – x0 = -2, or y2 – y0 = -1, then xc = (x0 – 1) if y2 – y0 = 2 or y2 – y0 = 1, (a) (b) figure 8. capturing; (a) direct; (b) diffuse figure 9. localized edge boundary figure 10. original coordinate with noise figure 11. original coordinate difference e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 33 then yc = (y0 + 1) if y2 – y0 = -2 or y2 – y0 = -1, then yc = (y0 – 1) designed filter replaces jumping pixels so the differences are located from -1 to 1 as shown in figure 13. table 4 shows filtered in pixel coordinate and final result in cartesian coordinate. figure 14 shows plotted filtered coordinate in matlab graphic. combined finding and filter algorithm successfully find continuous pixel coordinate which is main idea in point to point trajectory. c. generating trajectory from pixel coordinate pixel coordinate which plotted in figure 11 has sequence start from initial pixel to next pixel up to last pixel in clockwise direction. initial pixel is (14,-70) as the most left pixel in quadrant ii and the last is (15,-70). deviation from pixel n to pixel n+1 is calculated to generate vector direction code. generated code from cartesian coordinate in table 4 is saved in .txt file and the code list is shown in tabel 5. figure 15 figure 12. flowchart filter pixel coordinate figure 13. filtered coordinate difference table 4. filtered coordinate point pixel coordinate cartesian coordinate x y x y 1 14 70 14 -70 2 14 69 14 -69 3 14 68 14 -68 4 14 67 14 -67 5 14 66 14 -66 6 14 65 14 -65 7 14 64 14 -64 8 14 63 14 -63 9 14 62 14 -62 10 14 61 14 -61 ……. ……. ……. ……. ……. ……. ……. ……. ……. ……. 1,007 17 79 17 -79 1,008 16 78 16 -78 1,009 16 77 16 -77 1,010 16 76 16 -76 1,011 16 75 16 -75 1,012 15 74 15 -74 1,013 15 73 15 -73 1,014 15 72 15 -72 1,015 15 71 15 -71 1,016 15 70 15 -70 e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 34 represents point to point trajectory from generated vector direction codes. generated codes are point to point trajectory which form sealant path, figure 16. codes will be sent using serial communication from pc to controller robot in controlling axes movement which is actuated by dc motor. cartesian robot has simple movement direction such as horizontal, vertical and diagonal with constant speed, and the position control functions figure 14. filtered coordinate figure 15. point to point trajectory figure 16. point to point trajectory table 5. direction code list point direction code to next point 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 2 10 2 ……. ……. ……. ……. 1,007 2 1,008 1 1,009 2 1,010 2 1,011 2 1,012 1 1,013 2 1,014 2 1,015 2 1,016 2 figure 17. flow chart axis movement e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 35 only to follow the direction code in point to point manner. figure 17 shows flow chart robot axis movement in following trajectory generated by vector direction code. the rotation angle of dc motor rotation θ is calculated according to correlation between pixel displacement and stroke of the axis. figure 18 shows stroke and ball screw. this robot uses stroke with 5 mm lead, it means 1 full motor rotation bring 5 mm displacement in x or y. thus, 1.25 mm displacement from 1 pixel to another neighbor pixel needs 0.25 motor rotation or 90°. motor will be controlled at certain constant speed and the step reference value along each axis is 90° in every movements. the cartesian robot is shown at figure 19. iv. conclusions lighting has main role in capturing process to get good image, so that edge can be detected accurately. by the experiments, diffuse lighting technique with evenly spreading light gives better results than direct one both high intensity and low intensity. but, high light intensity frequently causes reflection and shadow that disguise the real edge at detection process. designed edge detection algorithm has good performance in intensity 10 cd – 3,000 cd with diffuse lighting technique, but the best result is 10 cd. the outer most edge pixel has been obtained by applying integral projection and its coordinates have been successfully founded by scanning algorithm. 1,016 continuous coordinates are successfully found and sealant path has accurate shape with captured machine which was verified with matlab graphic plot. it consists of connected point to point trajectory which the distance a point to next point equal to 90° motor rotation in x axis, y axis or both of them. directional movement for point to point trajectory is controlled by generated codes. in further research, codes are sent to robot controller using serial communication as instruction for axis movement to do sealant process. each axis is actuated by dc motor that its rotation position controlled according to certain direction and displacement. acknowledgement the author would like to thank the electronic engineering polytechnic institute of surabaya for giving laboratories facilities for the research and astra manufacturing polytechnic for providing financial support. references [1] y. maddahi, "reliability and quality improvement of robotic manipulation systems," wseas transactions on systems and control, vol. volume 6, pp. 339-348, 2011. [2] s. brell-cokcan, "a new parametric design tool for robot milling," acadia, 2010. [3] e. pitowarno, et al.,"knowledge-based trajectory error pattern method applied to an active force control scheme," iium engineering journal, vol. 3 no.1, 2002. [4] b. takarics and p. t. szemes, "super flexible welding robot based on the intelligent space concept," presented at the 7th international symposium of hungarian researchers on computational intelligence, 2008. [5] b. kuljic, "pathfinding based on edge detection and infrared distance measuring sensor," acta polytechnica hungarica, vol. 6 no.1, pp. 103-116, 2009. [6] m. mirdanies, et al., "object recognition system in remote controlled weapon station using sift and surf methods," journal of mechatronics, electrical power and vehicular technology, vol. 04, no. 2, pp. 99-108, 2013. doi : 10.14203/j.mev.2013. v4.99-108 [7] e. s. maarif, "applied canny edge detection in trajectory planning for auto figure 18. stroke and ball screw of the axis figure 19. cartesian robot e. s. ma’arif et al. / mechatronics, electrical power, and vehicular technology 05 (2014) 27-36 36 sealant cartesian robot," in indonesian symposium on robot soccer competition 2013, semarang, indonesia, 2013. [8] e. nadernejad, "edge detection techniques: evaluations and comparisons," applied mathematical sciences, vol. 2, no. 31, pp. 1507 – 1520, 2008. [9] p. kalra. “canny edge detection,”. lecturer classroom. department of computer science and engineering. india institute of technology, new delhi. 2009. [online]. available: www.cse.iitd.ernet.in/~pkalra/csl783/canny. pdf [10] y. surya, "machine vision implementation in rapid pcb prototyping," journal of mechatronics, electrical power, and vehicular technology, vol. 02, no. 2, pp. 79-84, 2011. doi : 10.14203 /j.mev.2011. v2.79-84 [11] s. dutta and b. b. chaudhuri, "a color edge detection algorithm in rgb color space," in international conference on advances in recent technologies in communication and computing., 2009, pp. 337-340. [12] m. juneja and p. s. sandhu, "performance evaluation of edge detection techniques for images in spatial domain," international journal of computer theory and engineering, vol. 01, no. 5, pp. 614621, december 2009. [13] g. t. shrivakshan and c. chandrasekar, "a comparison of various edge detection techniques used in image processing," international journal of computer science issues (ijcsi), vol. vol. 9, issue 5, no. 1, pp. 269 -276, september 2012. [14] p. zhou, "an improved canny algorithm for edge detection," journal of computation information systems, pp. 1516-1523, 2011. [15] g. j. mohammed, "eyeball localization based on angular integral projection function," slovenian society informatica, vol. 33 issue 4, pp. 475-480, november 2009. [16] s. p. khandait, et al., "comparative analysis of anfis and nn approach for expression recognition using geometry method," international journal of advanced research in computer science and software engineering, vol. 2, issue 3, march 2012. [17] l. xiao-yan and c. yan-li, "application of dijkstra algorithm in logistics distribution lines," in third international symposium on computer science and computational technology (iscsct ’10), jiaozuo, p. r. china, august, 2010, pp. 048-050. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 05, 2014 authors index aam muharam,“ evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system,” 05(2): 83-90 abdul hapid,“ evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system,” 05(2): 83-90 achmad praptijanto, “experimental investigation of 2 nd generation bioethanol derived from emptyfruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 9-16 adha iman cahyadi, “design and implementation of a magnetic levitation system controller using global sliding mode control,” 05(1): 17-26 aditya sukma nugraha, “design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle,” 05(2): 75-82 anwar muqorobin, “comparison of unmodulated current control characteristics of permanent magnet synchronous motor,” 05(2): 115-122 arifin nur, “experimental investigation of 2 nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 9-16 arifin nur, “techno-economic analysis of biogas utilization as an alternative fuel,” 05(1): 51-58 arjon turnip, “an experiment of ocular artifacts elimination from eeg signals using ica and pca methods,” 05(2): 129-136 bagus budiwantoro, “design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle,” 05(2): 75-82 budi prawara, “distributed control system design for portable pc based cnc machine,” 05(1): 37-44 carlo t. sevillano, “design and development of rc railed robot for coffee nursery logistics,” 05(2): 107-114 dany perwita sari, “cfd and wind tunnel analysis for mounted-wind turbine in a tall building for power generation,” 05(1): 45-50 edy junaidi, “an experiment of ocular artifacts elimination from eeg signals using ica and pca methods,” 05(2): 129-136 eka samsul maarif, “a trajectory generation method based on edge detection for auto-sealant cartesian robot,” 05(1): 27-36 endra pitowarno, “a trajectory generation method based on edge detection for auto-sealant cartesian robot,” 05(1): 27-36 endra pitowarno, “proportional derivative active force control for “x” configuration quadcopter,” 05(2): 67-74 estiko rijanto, “design of vibration absorber using spring and rubber for armored vehicle 5.56 mm caliber rifle,” 05(2): 75-82 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 viii hari setiapraja, “the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation,” 05(1): 59-66 haznan abimanyu, “experimental investigation of 2 nd generation bioethanol derived from empty-fruitbunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 9-16 hilman syaeful alam, “rotor-dynamic characteristic evaluation of interior permanent magnet motor using finite element method,” 05(1): 1-8 i gede puja astawa, “proportional derivative active force control for “x” configuration quadcopter,” 05(2): 67-74 iwan r. setiawan, “an experiment of ocular artifacts elimination from eeg signals using ica and pca methods,” 05(2): 129-136 kang-pyo cho, “cfd and wind tunnel analysis for mounted-wind turbine in a tall building for power generation,” 05(1): 45-50 kristian ismail, “techno-economic analysis of biogas utilization as an alternative fuel,” 05(1): 51-58 le hoa nguyen, “an experiment of ocular artifacts elimination from eeg signals using ica and pca methods,” 05(2): 129-136 marivic g. dizon, “design and development of rc railed robot for coffee nursery logistics,” 05(2): 107-114 mark anthony t. cabaluna, “design and development of rc railed robot for coffee nursery logistics,” 05(2): 107-114 merry indahsari devi, “techno-economic analysis of biogas utilization as an alternative fuel,” 05(1): 51-58 muhammad redho kurnia,“ evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system,” 05(2): 83-90 ni’am tamami, “proportional derivative active force control for “x” configuration quadcopter,” 05(2): 67-74 o. shoubaky, “learning efficiency of consciousness system for robot using artificial neural network,” 05(2): 91-98 oyas wahyunggoro, “design and implementation of a magnetic levitation system controller using global sliding mode control,” 05(1): 17-26 pudji irasari, “rotor-dynamic characteristic evaluation of interior permanent magnet motor using finite element method,” 05(1): 1-8 pudji irasari, “comparison of unmodulated current control characteristics of permanent magnet synchronous motor,” 05(2): 115-122 rizqon fajar, “the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation,” 05(1): 59-66 roni permana saputra, “distributed control system design for portable pc based cnc machine,” 05(1): 37-44 rudi uswarman, “design and implementation of a magnetic levitation system controller using global sliding mode control,” 05(1): 17-26 rusminto tjatur widodo, “a trajectory generation method based on edge detection for auto-sealant cartesian robot,” 05(1): 27-36 sabar pangihutan simanungkalit, “experimental investigation of 2 nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 916 sunarto kaleg,“ evaluation of potential usage of incremental-type rotary encoder application for angle sensing in steering system,” 05(2): 83-90 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ix t. m. sharari, “learning efficiency of consciousness system for robot using artificial neural network,” 05(2): 91-98 taufik, “comparison of unmodulated current control characteristics of permanent magnet synchronous motor,” 05(2): 115-122 tinton dwi atmaja, “distributed control system design for portable pc based cnc machine,” 05(1): 37-44 yan irawan, “experimental investigation of 2 nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 9-16 yanuandri putrasari, “experimental investigation of 2 nd generation bioethanol derived from emptyfruit-bunch (efb) of oil-palmon performance and exhaust emission of si engine,” 05(1): 9-16 zaini dalimus, “braking system modeling and brake temperature response to repeated cycle,” 05(2): 123-128 zulfiqar ali soomro, “adhesion detection analysis by modeling rail wheel set dynamics under the assumption of constant creep coefficient,” 05(2): 99-106 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 x journal of mechatronics, electrical power, and vehicular technology volume 05, 2014 affiliation index astra manufacturing polytechnic, indonesia 27 cavite state university, philippines 107 ckp wind solutions, korea 45 center for thermodynamic, motor and propulsion, the agency for assessment and application of technology (btmp-bppt), indonesia 89 computer and intelligent systems center, jordan 91 department of electrical engineering, andalas university, indonesia 123 department of electrical engineering, control laboratory and automation, jordan 91 department of electrical engineering, the university of danang, vietnam 129 department of electrical engineering, universitas gadjah mada (ugm), indonesia 17 department of physics, indonesian university of education, indonesia 129 directorate of post-graduate studies, mehran university of engg & tech jamshoro (sindh), pakistan 99 electronic engineering polytechnic institute of surabaya , indonesia 27, 67 electric power institute, california polytechnic state university, united states of america (usa) 115 faculty of mechanical and aerospace engineering, institut teknologi bandung (itb), indonesia 75 research center for biomaterials, indonesian institute of sciences (lipi), indonesia 45 research center for chemistry, indonesian institute of sciences (lipi), indonesia 9 research centre for electrical power and mechatronics,indonesian institute of sciences (lipi), indonesia 1, 9, 37, 51, 75, 83, 115 school of mechanical and manufacturing engineering, the university of new south wales, australia 37 technical implementation unit for instrumentation development, indonesian institute of sciences (lipi), indonesia 1, 129 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xi journal of mechatronics, electrical power, and vehicular technology international peer reviewers prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, bld 20, 2 nd fl, bandung 40135 indonesia estiko.rijanto@ lipi.go.id prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia a.setiawan@ugm.ac.id dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, bld 20, 2 nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia epit@eepis-its.edu dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id mailto:patko@uni-obuda.hu mailto:a.setiawan@ugm.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xii dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8 th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia trina.fizzanty@lipi.go.id dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia amsriasih@ugm.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia masimam@jteti.gadjahmada.edu esa prakasa, ph.d. research centre for informatics – lipi, komp lipi jlsangkuriang, bld 20, 3 rd fl, bandung 40135, indonesia esa.prakasa@lipi.go.id dr. edi kurniawan, s.t., m.eng. research centre for informatics – lipi, komp lipi jlsangkuriang, bld 20, 3 rd fl, bandung 40135, indonesia edi.kurniawan@lipi.go.id dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, bld 20, 2 nd fl, bandung 40135, indonesia moch019@lipi.go.id pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, bld 20, 2 nd fl, bandung 40135, indonesia pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiii publication ethics and malpractice statement mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics lipi). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiv 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xv author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with coma and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 04, 2013 authors index aam muharam, “the influence of two cylinder diesel engine modification (idi to di) on the performance and its emission,” 04(1): 17-24 ade ramdan, “modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method,” 04(1): 33-40 adi santoso, “effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia,” 04(1): 25-32 agus risdiyanto, “modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method,” 04(1): 33-40 andri joko purwanto, “effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia,” 04(1): 25-32 ari legowo, “maximum power point tracking of photovoltaic system for traffic light application,” 04(1): 57-64 arif santoso, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109-116 arifin nur, “the influence of two cylinder diesel engine modification (idi to di) on the performance and its emission,” 04(1): 17-24 arjon turnip, “the performance of eeg-p300 classification using backpropagation neural networks,” 04(2): 81-88 arjon turnip,“autoregressive integrated adaptive neural networks classifier for eeg-p300 classification,” 04(1): 1-8 ary setijadi prihatmanto, “object recognition system in remote controlled weapon station using sift and surf methods,” 04(2): 99-108 bambang wahono, “combustion property analysis and control system for the dynamics of a single cylinder diesel engine,” 04(2): 117-126 camilo andreas,“optimization for biogas power plants using automatic control of gas pressures,” 04(1): 9-16 dayat kurniawan, “design and development of a control system for nanofiber electrospinning,” 04(2): 65-74 demi soetraprawata, “autoregressive integrated adaptive neural networks classifier for eeg-p300 classification,” 04(1): 1-8 demi soetraprawata, “the performance of eeg-p300 classification using backpropagation neural networks,” 04(2): 81-88 dodiek ika candra, “optimization for biogas power plants using automatic control of gas pressures,” 04(1): 9-16 dwi ajiatmo, “mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car,” 04(2): 127-134 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 viii estiko rijanto, “imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism,” 04(1): 41-50 estiko rijanto, “object recognition system in remote controlled weapon station using sift and surf methods,” 04(2): 99-108 ghalya pikra, “effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia,” 04(1): 25-32 harutoshi ogai, “combustion property analysis and control system for the dynamics of a single cylinder diesel engine,” 04(2): 117-126 hendri maja saputra, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109-116 hendri maja saputra, “imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism,” 04(1): 41-50 heri suryoatmojo, “mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car,” 04(2): 127-134 hilman syaeful alam, “quality improvement evaluation of the modified diesel-electric train (krde),” 04(1): 51-56 imam robandi, “mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car,” 04(2): 127-134 irhan febijanto, “economic analysis of cikaso mini hydro power plant as a cdm project for increasing irr,” 04(2): 89-98 lukni maulana, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109-116 m. faisal amir, “design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter,” 04(2): 75-80 midriem mirdanies, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109116 midriem mirdanies, “object recognition system in remote controlled weapon station using sift and surf methods,” 04(2): 99-108 moh. zaenal efendi, “design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter,” 04(2): 75-80 muhammad nasir, “design and development of a control system for nanofiber electrospinning,” 04(2): 65-74 nor hilmi mohamad, “maximum power point tracking of photovoltaic system for traffic light application,” 04(1): 57-64 noviadi arief rachman, “modeling of electric field around 100 mva 150/20 kv power transformator using charge simulation method,” 04(1): 33-40 novie ayub windarko, “design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter,” 04(2): 75-80 purwoko adhi, “design and development of a control system for nanofiber electrospinning,” 04(2): 6574 riastus nayanti, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109-116 riza muhida, “maximum power point tracking of photovoltaic system for traffic light application,” 04(1): 57-64 rudi irawan, “maximum power point tracking of photovoltaic system for traffic light application,” 04(1): 57-64 seno aji, “mppt based on fuzzy logic controller (flc) for photovoltaic (pv) system in solar car,” 04(2): 127-134 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ix taufik hidayat, “quality improvement evaluation of the modified diesel-electric train (krde),” 04(1): 51-56 vikita windarwati, “control of pan-tilt mechanism angle using position matrix method,” 04(2): 109116 wang xiaoli, “combustion property analysis and control system for the dynamics of a single cylinder diesel engine,” 04(2): 117-126 wilches tamayo,“optimization for biogas power plants using automatic control of gas pressures,” 04(1): 9-16 winda astuti, “maximum power point tracking of photovoltaic system for traffic light application,” 04(1): 57-64 yanuandri putrasari, “the influence of two cylinder diesel engine modification (idi to di) on the performance and its emission,” 04(1): 17-24 zainal abidin, “imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism,” 04(1): 41-50 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 x journal of mechatronics, electrical power, and vehicular technology volume 04, 2013 affiliation index bwe biogas-weser-ems gmbh & co. kg, germany 9 centre for technology of energy resources development, deputy for technology of informatic, energy and mineral, bppt, indonesia 89 department of electrical engineering, institut teknologi sepuluh nopember (its), indonesia 127 department of electrical engineering, politeknik elektronika negeri surabaya (pens), indonesia 75 department of electrical engineering, universitas darul ulum jombang, indonesia 127 department of mechanical engineering, international islamic university malaysia, malaysia 57 department of mechatronics engineering, international islamic university malaysia, malaysia 57 faculty of mechanical and aerospace engineering, institutteknologi bandung (itb), indonesia 41 foster electric. co., ltd, japan 117 graduate school of information, production and systems, waseda university, japan 117 mechatronics department, faculty of engineering, yogyakarta state university (uny), indonesia 109 research center for chemical, indonesian institute of sciences (lipi), indonesia 65 research center for electronics and telecommunication, indonesian institute of sciences (lipi), indonesia 65 research center for informatics, indonesian institute of sciences (lipi), indonesia 33 research centre for electrical power and mechatronics,indonesian institute of sciences (lipi), indonesia 9, 17, 25, 33, 41, 99, 109,117 school of electrical engineering and informatics, bandung institute of technology (itb), indonesia 99 surya university, indonesia 57 technical implementation unit for instrumentation development, indonesian institute of sciences (lipi), indonesia 1, 51, 81 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xi journal of mechatronics, electrical power, and vehicular technology international peer reviewers prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering,universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135 indonesia estiko.rijanto@ lipi.go.id prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2,yogyakarta 55281, indonesia a.setiawan@ugm.ac.id dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com mailto:patko@uni-obuda.hu mailto:a.setiawan@ugm.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xii dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia moch019@lipi.go.id dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8 th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia trina.fizzanty@lipi.go.id dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia amsriasih@ugm.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiii publication ethics and malpractice statement mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics lipi). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiv 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xv author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with coma and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v international peer reviewers acknowledgement prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia estiko.rijanto@ lipi.go.id prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia, depok, indonesia, dasumarsono@gmail.com george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia a.setiawan@ugm.ac.id dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com mailto:patko@uni-obuda.hu mailto:a.setiawan@ugm.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi dr. endra joelianto engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia epit@eepis-its.edu dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia trina.fizzanty@lipi.go.id dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia amsriasih@ugm.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia masimam@jteti.gadjahmada.edu dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia moch019@lipi.go.id dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta, jl. ir. sutami 36a, surakarta, 57126, indonesia wahyudisutopo@gmail.com esa prakasa, ph.d research centre for informatics – lipi, komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia esa.prakasa@gmail.com dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi, komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia ekurniawan@live.com dr. arjon turnip technical management unit for instrumentation development lipi, komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia jujhin@gmail.com pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, blg 20, 2ndfl, bandung 40135, indonesia pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with semi colon and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev j. mechatron. electr. power veh. technol. 06 (2015) 123-128 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.123-128 estimating power needed to fuel electric paratransits in bandung naili huda a, *, kim p. hassall b, aam muharam a, kristian ismail a aresearch centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu/sangkuriang, bandung 40135, indonesia bdepartment of infrastructure engineering, melbourne school of engineering engineering blocks b, c & d, the university of melbourne parkville 3010 vic, australia received 19 september 2014, received in revised form 17 november 2015, accepted 29 november 2015 published online 30 december 2015 abstract this is the preliminary finding of a study elaborating the total energy consumption when paratransits in bandung are altered into electric and the scenario to fulfill it. therefore, there are lots to be done further concerning result of this initial research, of which will be discussed in another publication. in this paper calculation was done to find out the volume of power needed to fuel electric paratransits in bandung. steps carried out include computing total energy consumption for all paratransits, clustering stations from classified routes established by local department of transport, and estimating the electricity demand in every clustered station. data used for this study was acquired from badan pusat statistik kota bandung and pt pln dja apd jawa barat and banten. a total demand of 61.12 mwh per month will surface to charge the total of 5,521 paratransits from 38 available routes in 15 clustered stations under the assumptions that all paratransits only make 6 return travels per day, operate 30 days per month, and use batteries with 50% state of charge. keywords: transportation; electric paratransit; in town; electricity demand; feasibility study. i. introduction functioning in a small yet busy city, bandung transportation is excessively active while on the other hand pollution it produces is too much. these facts make bandung a potential project site for electric car initiative. despite its pricey purchase cost [1], electric vehicle (ev) provides solution to lower pollution level and operation as well as maintenance costs reduction [2-5]. best when applied for mass transport [6] for the sake of more pollution cutback, electric vehicle conversion then could be suitable when implemented to paratransit. existing research on indonesian paratransit mainly discuss about general problems surrounding paratransit [7-9], tariff, service and customer perception [9, 10], the effect of air pollution it creates [11, 12], driver welfare [1315], routes and programming [16-19], paratransit stop design [20], and feasibility on fleet addition [21]. on bandung paratransit in particular, main research were done related to user satisfaction [9, 22, 23] and feasibility of electric paratransit initiative [24] which emphasizes on cost rather than energy implication. as the pilot of a more comprehensive research, this paper is limited only to find out total electricity should be made available by the government to guarantee full operation of paratransits when they are converted into electric in bandung. conversion could cover retrofitting the available paratransit into electric or procure a full brand new electric vehicle for paratransit. how the demand would be satisfied is beyond the scope of this paper. ii. methodology this study was done according to simple steps illustrated in figure 1. with single aim of giving rough estimation of energy demand when paratransits in bandung turned electric, these following factors are not taken into account in all calculations performed. it has to be born in mind that this study assumes all routes to have the * corresponding author.tel: +62-22-2503055 e-mail: vedderforeva@yahoo.com http://dx.doi.org/10.14203/j.mev.2015.v6.123-128 n. huda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 123-128 124 same topology, hence using average energy consumption. it is known that topology, traffic, driving style and temperature are of factors affecting energy consumption in ev [25]. in reality, routes topology probably a lot differs, resulting bias from the calculated energy consumption, either too high or even too low. moreover, it was presumed that electric paratransits are retrofitted into electric using electric motor that still fulfills the function of their old internal combustion engines and fueled using lead acid batteries. furthermore, regardless distance of each route, all routes are supposed to travel 6 returns per day. actually, they can travel less and often, more. this will affect the concrete total energy consumption as well. to provide a glimpse of what is paratransit, figure 2 displays the multicolored paratransits in bandung whose colors define routes [26]. using basic retrofitted paratransit in [24], presuming power consumption of retrofitted paratransit would be 500 wh/mile, lead acid battery energy of 31,680 wh and battery state of charge (soc) of 50%, maximum distance that can be obtained per charge is approximately 51 km. there are 5,521 paratransits available in bandung, accommodating 38 routes with route distances range from 7 to more than 24 km one way [27]. for each route, first thing done was calculating kilometer traveled per day for each vehicle, which is 6 returns or equals to 12 times one-way distance. using 1 mile = 1.61 km, we got energy consumption of 310.56 wh/km. considering vehicle load which is about to carry 15 people, this number is in line with other research where a smart ed of 2 passengers consumes 0.17 wh/km [28] and another passenger vehicle consumes an average of 0.62 mj/km [29] or 172.22 wh/km when air conditioner is off. by multiplying this energy consumption per kilometer with total distance traveled per day, energy consumption per day per vehicle was found. multiplying again this number with the quantity of paratransit per route, energy consumption of all paratransits per route per day then is resulted. to find total energy consumption for all paratransit, energy consumptions of all paratransits from all routes were aggregated. next step was clustering the avalaible routes to classify paratransits in which route should be charged in which station. clusters are set in compliance with route and station convenience, and rough observation of paratransit in which route usually be mostly parked in or near which station. routes, distance of each route, total energy consumption and alternative clustering are recapped in table 1. iii. results and discussion total energy needed per day to run all retrofitted paratransits in bandung is 2,037,397.824 wh. this makes 61.12 mwh per month. albeit an official yet confidential data obtained from pt pln apd jawa barat and banten [30] which seems like a safe supply for the charging needs, it does not mean that charging process can be done anywhere at any time. mapping should be done in defining which nearest main distributing point can supply the power and at what time slot charging should be done to make sure electricity is sufficiently available, hence preventing blackout. this will be covered in another paper. as this is a paper that leads to a feasibility study and not analyzing present application, scenario concerning number of paratransits involved in this electrification project can actually later be extrapolated. this is critical to define which number will match bandung capability in providing electricity to support eparatransits. extrapolation can be executed concerning degree of electrification covering which routes should be involved, number of altered paratransits per route, work hours, number of travels and state of charge (soc). lessening routes number will decrease the power demand. from road topology point of view, this would be wise if implemented to routes that have hilly road topology. hilly road calls for higher energy consumption than estimated, hence higher energy demand. for shorter routes (10 km and below), e-paratransit application would be convenience as charging can be done after 2-time returns. cutting the number of paratransits to be converted to electric will cut the total energy consumption as well. not to mention reducing the number of work hour and travels per day. in contrast, lowering or increasing soc will not have significant effect to total energy consumption. to charging process, the action figure 1. methodology of this study n. huda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 123-128 125 table 1. total energy consumption and proposed stations clustering n o . r o u te * d is ta n c e * σ d is ta n c e /w a y σ v e h ic le s σ v e h ic le s e n e r g y c o n s u m p ti o n σ e n e r g y c o n s u m p ti o n c lu st e r e d s ta ti o n (k m ) /s ta ti o n ( k m ) /r o u te ( u n it s) /s ta ti o n ( u n it s) /1 2 w a y o r a d a y ( w h ) /s ta ti o n /d a y ( w h ) n a m e 1 a b d u l m u is – c ic a h e u m v ia b in o n g 1 6 .3 0 4 8 .1 5 3 6 9 5 9 5 6 0 ,7 4 6 1 7 9 ,4 4 1 .5 7 1 . a b d u l m u is 2 a b d u l m u is – c ic a h e u m v ia a c e h 1 1 .5 5 1 0 0 4 3 ,0 4 4 3 a b d u l m u is – e la n g 9 .7 5 1 0 1 3 6 ,3 3 6 4 a b d u l m u is – m e n g g e r 1 0 .5 5 2 5 3 9 ,3 1 7 5 a b d u l m u is – d a g o 9 .3 0 3 9 .9 0 2 7 3 5 2 6 3 4 ,6 5 8 1 4 8 ,6 9 6 .1 3 2 . d a g o 6 s ta si u n h a ll – d a g o 1 0 .0 0 5 2 3 7 ,2 6 7 7 d a g o – r iu n g b a n d u n g 2 0 .6 0 2 0 1 7 6 ,7 7 0 8 a b d u l m u is – l e d e n g 1 6 .0 0 5 0 .0 5 2 4 5 5 8 4 5 9 ,6 2 8 1 8 6 ,5 2 2 .3 4 3 . l e d e n g 9 c ic a h e u m – l e d e n g 1 4 .2 5 2 1 4 5 3 ,1 0 6 1 0 m a rg a h a y u – l e d e n g 1 9 .8 0 1 2 5 7 3 ,7 8 9 1 1 c ic a h e u m – c ir o y o m 1 7 .0 0 5 0 .1 0 2 0 6 5 5 6 6 3 ,3 5 4 1 8 6 ,7 0 8 .6 7 4 . c ic a h e u m 1 2 c ic a h e u m – c iw a st ra – d e rw a ti 1 7 .0 0 2 0 0 6 3 ,3 5 4 1 3 c ic a h e u m – c ib a d u y u t 1 6 .1 0 1 5 0 6 0 ,0 0 0 1 4 s ta si u n h a ll – s a d a n g s e ra n g 1 1 .0 0 2 9 .1 0 1 5 0 3 5 0 4 0 ,9 9 4 1 0 8 ,4 4 7 .5 5 5 . s a d a n g s e ra n g 1 5 s a d a n g s e ra n g – c a ri n g in 1 8 .1 0 2 0 0 6 7 ,4 5 4 1 6 s ta si u n h a ll – c iu m b u le u it v ia e y k m a n 9 .8 0 1 8 .1 0 6 0 1 0 0 3 6 ,5 2 2 6 7 ,4 5 3 .6 3 6 . c iu m b u le u it 1 7 s ta si u n h a ll – c iu m b u le u it v ia c ih a m p e la s 8 .3 0 4 0 3 0 ,9 3 2 1 8 s ta si u n h a ll – g e d e b a g e 2 1 .0 0 3 9 .7 0 2 0 0 3 3 0 7 8 ,2 6 1 1 4 7 ,9 5 0 .7 8 7 . s ta si u n h a ll 1 9 s ta si u n h a ll – s a ri ja d i 1 0 .2 0 7 5 3 8 ,0 1 3 2 0 s ta si u n h a ll – g u n u n g b a tu 8 .5 0 5 5 3 1 ,6 7 7 2 1 p a sa r in d u k c a ri n g in – d a g o 1 9 .8 5 6 3 .5 5 1 4 0 4 2 0 7 3 ,9 7 5 2 3 6 ,8 3 3 .0 6 8 . d ip a ti u k u r 2 2 p a n g h e g a r p e rm a i – d ip a ti u k u r – d a g o 1 9 .3 5 1 5 5 7 2 ,1 1 2 2 3 b u m i p a n y il e u k a n – s e k e m ir u n g 2 4 .3 5 1 2 5 9 0 ,7 4 6 2 4 c ir o y o m – s a ri ja d i 1 1 .7 5 4 6 .7 0 9 7 4 9 7 4 3 ,7 8 9 1 7 4 ,0 3 7 .8 2 9 . c ir o y o m 2 5 c ir o y o m – b u m i a sr i 8 .3 5 1 1 5 3 1 ,1 1 8 2 6 c ir o y o m – c ik u d a p a te u h 1 2 .9 0 1 2 5 4 8 ,0 7 5 2 7 a n ta p a n i – c ir o y o m 1 3 .7 0 1 6 0 5 1 ,0 5 6 2 8 s e d e rh a n a – c ip a g a lo 1 6 .0 5 3 3 .9 5 2 7 6 3 9 8 5 9 ,8 1 4 1 2 6 ,5 2 2 .1 4 1 0 . s e d e rh a n a 2 9 s e d e rh a n a – c ij e ra h 8 .9 0 6 7 3 3 ,1 6 8 3 0 s e d e rh a n a – c im in d i 9 .0 0 5 5 3 3 ,5 4 0 3 1 c iw a st ra – u ju n g b e ru n g 1 3 .4 0 3 5 .7 0 3 2 2 3 2 4 9 ,9 3 8 1 3 3 ,0 4 3 .9 0 1 1 . c iw a st ra 3 2 c ij e ra h – c iw a st ra – d e rw a ti 2 2 .3 0 2 0 0 8 3 ,1 0 6 3 3 c is it u – t e g a ll e g a 1 3 .9 5 1 3 .9 5 8 2 8 2 5 1 ,9 8 8 5 1 ,9 8 7 .7 4 1 2 . c is it u 3 4 e la n g – g e d e b a g e – u ju n g b e ru n g 2 2 .4 5 4 7 .5 0 1 1 5 4 5 0 8 3 ,6 6 5 1 7 7 ,0 1 9 .2 0 1 3 . e la n g 3 5 c ib o g o – e la n g 7 .0 0 3 5 2 6 ,0 8 7 3 6 c ic a d a s – e la n g 1 8 .0 5 3 0 0 6 7 ,2 6 7 3 7 c ic a d a s – c ib ir u – p a n y il e u k a n 1 3 .6 5 1 3 .6 5 2 0 0 2 0 0 5 0 ,8 7 0 5 0 ,8 6 9 .7 3 1 4 . c ib ir u 3 8 c ib a d u y u t – k a ra n g s e tr a 1 6 .6 0 1 6 .6 0 2 0 1 2 0 1 6 1 ,8 6 4 6 1 ,8 6 3 .5 5 1 5 . c ib a d u y u t t o t a l 5 4 7 .0 0 5 4 7 .0 0 5 ,5 2 1 5 ,5 2 1 2 ,0 3 7 ,3 9 7 2 ,0 3 7 ,3 9 7 .8 2 * d a ta i s ta k e n f ro m [ 2 7 ] n. huda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 123-128 126 will only affect charging schedule since the charging should be done earlier and shorter (when soc is smaller) or later and longer (when soc is bigger). from 38 routes, it was created 15 charging stations based on rough observation of majority paratransit settled on the stations when not in operation, and distance of paratransit parking and owner dwellings. table 1 lists all that proposed charging locations. actually, this kind of clustering might not be effective since there will be lots of efforts to put it into realization. the problem is when not in use paratransits are usually parked within the close proximity of the owners, which are often located far from the stations. therefore, if paratransits are charged in the stations, then to be brought home to the owners, the energy reserved for the next run the day after will be lessened. there are two proposed ways to overcome this. first, build a station where people can park their paratransit as well as charge them. even though this is one manifestation of government interference, the cost would be massive, for building and security officer for instance. or instead, conduct a survey to map locations of each paratransit park lot, and subsequently create new locations for charging station and its new capacity as oppose from the old charging stations clustered above. this can be solved by providing a battery exchange, a big wide warehouse where batteries are charged to be readily used later. this is just a convenience clustering that actually needs to be further investigated. the ideal should incorporate detail process comprising mapping paratransit parking locations, mapping electricity supply at potential or designated charging hours, matching number of charging needs with charging supply, and last but not least, interviewing stakeholders. as transportation is the main contributor for air pollution in bandung [31], and shifting to environmentally safe fuel and vehicle can be the way out [32] [33], paratransit electrification could be the answer to bandung’s circumstances. beside, global condition creates a more conducive movement for electric vehicle application [34]. in accordance to fund in creating start-up fleet, government should do its best to establish a funding policy for this matter [2]. be it the government, private sectors or other possible third parties. as considering cost to procure one electric paratransit could reach idr 500 million, or idr 450 million via retrofitting [24], sum of money should be provided would be huge. this cost falls mostly for batteries, which need to be replaced approximately once a year when lead acid is used. this cost will decline due to mass electrification since for example, battery price will decrease from bulk buy [3, 35]. nevertheless, it still involved so much money. further discussion about this is not within the reach of this paper. another option of charging stations is battery exchange or battery swapping stations. when battery is low, paratransit could visit a battery exchange station to have its empty battery be replaced with the fully loaded one. nonetheless, as the consequence, a big warehouse containing stacks of battery should be provided. this will bring new obligations like land acquisition, building construction, operational management and security. since the two alternatives in really have their own advantages and disadvantages, both can be executed according to circumstances of the future charging station locations. iv. conclusion paratransit electrification in bandung yields a power demand of virtually 62 mwh per month that should be met by energy provider, which in this case is indonesian government through pln (name of indonesian national electricity company). even the demand seems can be sufficiently fulfilled, careful planning should be conducted to ensure the demand will be satisfied without disturbing other industry. the planning will embrace obtaining real data on energy demand for paratransit electrification in bandung. field survey would be crucial in acquiring data to design and map places of charging stations taken into account paratransit parking and electricity availability at certain charging hours. acknowledgement gratitude goes to sunarto kaleg, m. redho kurnia, and abdul hapid for the useful discussion on ev retrofitting; arifin nur, yanuandri putrasari, achmad praptijanto, widodo budi santoso and bambang wahono on the potential of electric paratransit in bandung; pudji irasari and amin on data collection, and finally, to fitri rahma from pln jawa barat for providing electricity supply data. figure 2. paratransit colors interpret its specific route [26] n. huda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 123-128 127 references [1] a. kihm and s. trommer, "the new car market for electric vehicles and the potential for fuel substitution," energy policy, vol. 73, pp. 147-157, 10// 2014. [2] e. h. green et al., "increasing electric vehicle policy efficiency and effectiveness by reducing mainstream market bias," energy policy, vol. 65, pp. 562-566, 2// 2014. [3] t. muneer et al., "energetic, environmental and economic performance of electric vehicles: experimental evaluation," transportation research part d: transport and environment, vol. 35, pp. 40-61, 3// 2015. [4] z. a. needell, "technology evaluation for automobile transportation: electric vehicle energy requirements under real-world use," in electric vehicle energy requirements under real-world use, ed, 2015. [5] i. wolf et al., "changing minds about electric cars: an empirically grounded agent-based modeling approach," technological forecasting and social change, vol. 94, pp. 269-285, 5// 2015. [6] p. a. driscoll et al., "is the future of mobility electric? learning from contested storylines of sustainable mobility in iceland," european planning studies, vol. 20, pp. 627-639, 2012. [7] i. syabri and b. t. s. pradono, "embracing paratransit in bandung metropolitan area, west java, indonesia," 2011. [8] o. z. tamin, "integrated public and road transport network system for bandung metropolitan area (indonesia)," proc. eastern asia soc. transport. studies, vol. 5, pp. 1281-1300, 2005. [9] t. b. joewono et al., "paratransit transport in indonesia: characteristics and user perceptions," presented at the eastern asia society for transportation studies 2015 conference, cebu philipines, 2015. [10] y. o. susilo et al., "an exploration of public transport users’ attitudes and preferences towards various policies in indonesia: some preliminary results," journal of the eastern asia society for transportation studies, vol. 8, pp. 299-314, 2009. [11] h. anggraini and e. t. maharani, "paparan timbal (pb) pada rambut sopir angkot rute johar-kedungmundu," media kesehatan masyarakat indonesia, vol. 11, pp. 47-50, 2012. [12] d. condrorini et al., "gender aspects in public perception and acceptance of angkot stopping point as an effort to reduce roadside air pollution (case study of angkot in bandung, indonesia)," in proceedings: international conference on air quality management in southeast asia, 2007, p. 239. [13] c. nisa, "respon pengemudi jasa transportasi angkutan umum kota (angkot) kota bogor terhadap kenaikan harga bbm jenis premium," 2012. [14] a. d. rahayu, "model matematika pendapatan pengemudi angkutan kota (angkot) jalur adl dan al di malang," 2011. [15] w. weningtyas et al., "does improved level of paratransit service improve drivers’ quality of life?," journal of the eastern asia society for transportation studies, vol. 10, pp. 1367-1383, 2013. [16] f. arthuro, "aplikasi mobile rute angkot kota bekasi dengan sistem operasi android 2.3. 3 menggunakan adt bundle dan sqlite," 2013. [17] m. irawan, "penerapan algoritme dijkstra pada rute angkot bogor berbasis android," 2013. [18] o. f. saputra and h. b. e. prakoso, "kajian pelayanan rute moda angkutan kota (angkot) di kota cimahi," universitas gadjah mada, 2014. [19] e. s. wihidayat, "sistem informasi transportasi umum terpadu dengan sistem informasi geografis (sig) berbasis web, studi kasus angkutan umum kota bandung," universitas gadjah mada, 2013. [20] f. r. aulia and d. wahjudi, "pengembangan fasilitas transpotasi publik dengan desain halte dan rambu lalu lintas khusus pada halte di kota bandung," product design, vol. 3, 2014. [21] m. s. bahkri, "analisa kelayakan investasi penambahan armada angkot (studi kasus: perusahaan kopasri jurusan pilangsari– pasar bunder sragen)," universitas muhammadiyah surakarta, 2011. [22] a. tarigan et al., "negative experiences and willingness to use paratransit in bandung, indonesia: an exploration with ordered probit model," center for transport and society, vol. 15, p. 16, 2010. [23] a. k. tarigan et al., "segmentation of paratransit users based on service quality and travel behaviour in bandung, indonesia," transportation planning and technology, vol. 37, pp. 200-218, 2014. n. huda et al. / j. mechatron. electr. power veh. technol. 06 (2015) 123-128 128 [24] n. huda, "viability of lead acid battery conversion for electric paratransit initiative in bandung indonesia " master of engineering science, civil engineering, the university of melbourne, melbourne, 2009. [25] c. de cauwer et al., "energy consumption prediction for electric vehicles based on real-world data," energies (19961073), vol. 8, pp. 8573-8593, 2015. [26] -, "direktori info bandung," vol. 2015, ed, 2013. [27] badan pusat statistik kota bandung, "bandung city in figures," bandung2014. [28] t. donateo et al., "a method to estimate the environmental impact of an electric city car during six months of testing in an italian city," journal of power sources, vol. 270, pp. 487-498, 2014. [29] d. a. howey et al., "comparative measurements of the energy consumption of 51 electric, hybrid and internal combustion engine vehicles," transportation research part d: transport and environment, vol. 16, pp. 459-464, 2011. [30] p. p. a. jawa barat dan banten, "beban tertinggi 1 oktober 31 oktober 2015," ed. bandung, 2015. [31] n. ambarsari et al., "inventarisasi emisi black carbon, prekursor ozon (co, nox, spesi voc) dan penentuan ozone formation potential (studi kasus: bandung raya) emission inventory of black carbon, ozone precursors (co, nox, voc species) and quantifying of." [32] n. kusminingrum and g. gunawan, "polusi udara akibat aktivitas kendaraan bermotor di jalan perkotaan pulau jawa dan bali," jurnal, jakarta, puslitbang jalan dan jembatan, 2008. [33] h. ma et al., "a new comparison between the life cycle greenhouse gas emissions of battery electric vehicles and internal combustion vehicles," energy policy, vol. 44, pp. 160-173, 2012. [34] b. a. davis and m. a. figliozzi, "a methodology to evaluate the competitiveness of electric delivery trucks," transportation research part e: logistics and transportation review, vol. 49, pp. 823, 2013. [35] p. d. larson et al., "consumer attitudes about electric cars: pricing analysis and policy implications," transportation research part a: policy and practice, vol. 69, pp. 299-314, 11// 2014. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.11-22 kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi irhan febijanto pusat teknologi pengembangan sumberdaya energi, deputi teknologi informatika, energi dan mineralbppt gedung ii, lt. 22,jl. m.h. thamrin no. 8, jakarta pusat jakarta 10340, indonesia irhan.febijanto@gmail.com diterima: 30 maret 2011; direvisi: 11 april 2011; disetujui: 23 april 2011; terbit online: 7 juli 2011. abstrak pemanfaatan limbah tandan kosong sebagai bahan bakar pembangkit listrik merupakan salah satu pilihan pabrik kelapa sawit (pks) dalam usaha penanggulangan limbah tandan kosong. limbah tandan kosong saat ini belum banyak dimanfaatkan karena beberapa pilihan untuk pemanfaatan seperti penggunaan untuk bahan baku pupuk dan kompos sudah dilaksanakan akan tetapi hasilnya tidak efektif, terutama dalam pengolahan tandan kosong dalam jumlah besar. jumlah pembangkit listrik berbahan bakar limbah biomasa sawit yang menggunakan bahan bakar tandan kosong tidak banyak di indonesia. makalah ini menjelaskan secara teknis dan keekonomian pemanfaatan limbah tandan kosong di pks pinang tinggi, sei bahar, propinsi jambi, untuk pembangkit listrik. listrik di jual ke pt pln (persero). kelayakan keekonomian sangat rendah jika pendapatan tambahan dari penjualan remnant oil, abu sisa pembakaran dan penjualan kredit karbon tidak dimasukkan sebagai pendapatan. ketiga pendapatan tambahan dapat meningkatkan irr proyek dari 2,03% menjadi 15,12%. besarnya nilai investasi dan harga jual listrik sangat menentukan sensivitas keekonomian proyek. kata kunci: pabrik kelapa sawit, tandan kosong, cangkang, gas rumah kaca, kredit karbon. abstract utilization of empty fruit bunch (efb) waste as a fuel for power electric generation is one of the options available for palm oil factory in the effort to reduce efb waste. at the moment, there are several options to utilize efb waste such as fertilization and composting. however, both ways show ineffective result, particularly in handling huge amount of efb. up to now, indonesia only has a limited number of efb fueled power plants.this paper explains technically and economically efb fueled power plant supplying to pln grid in pinang tinggi palm oil factory located at sei bahar, jambi province. the economical feasibility is low, if the additional revenue generated from selling remnant oil, selling ash of efb and selling credit carbon are not counted as an income. using these additional revenues, the irr project increased from 2.03% to 15.12%. the investment cost and the selling electricity price are critical sensitivity factors for project economics. keyword: palm oil factory, empty fruit bunch, shell, green houses gasses, carbon credit. i. pendahuluan a. latar belakang limbah padat di pabrik kelapa sawit (pks) terdiri dari tandan kosong (empty fruit bunch/efb atau tks), cangkang (shell) dan serabut (fibre). pemanfaatan limbah padat, cangkang dan serabut sebagai bahan bakar sudah dilakukan pada ketel uap (boiler) di pks untuk menghasilkan uap air/steam untuk kebutuhan proses pabrik, dan membangkitkan listrik untuk kebutuhan pabrik maupun perumahan pegawai di sekitar pks. karakteristik tandan kosong berbeda dengan cangkang dan serabut, hal ini menyebabkan tandan kosong tidak dapat digunakan sebagai sumber energi secara langsung dengan menggunakan fasilitas yang sama dengan cangkang dan serabut. tandan kosong diketahui mengandung moisture/kandungan air yang sangat tinggi sekitar 50%-60%, dan mengandung potasium (k) yang mencapai 2,4% [1], selain itu juga diketahui mengandung klorin (cl). efek korosi akan meningkat dengan meningkatnya kandungan cl, dan unsur potasium dapat berperan dalam pembentukan deposit pada superheater yang dapat mengganggu proses pemindahan panas di tungku bakar [2]. karakteristik yang berbeda dari tks (tandan kosong), menyebabkan dibutuhkannya teknologi yang khusus dalam pemanfaatannya sebagai http://dx.doi.org/10.14203/j.mev.2011.v2.11-22 kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 12 gambar 1. fasilitas pembakaran tandan kosong. bahan bakar. pada prinsipnya untuk meningkatkan efisiensi pembakaran, kandungan air tks harus dikurangi sampai sekitar 40% dan efek dari unsur unsur alkali harus diatasi. penyemprotan zat aditif kimia dengan menggunakan sootblower ke permukaan pipa di dalam tungku bakar merupakan salah satu teknik untuk mengurangi pengaruh unsur unsur alkali seperti terjadinya deposit, sintering dan efek lainnya [3]. tetapi pada umumnya karena keterbatasan dana dan teknologi maka tandan kosong hanya dikumpulkan di sekitar pks untuk dibakar begitu saja. abu hasil pembakaran dipakai untuk pupuk oleh para petani di sekitar pks. fasilitas pembakaran yang umumnya digunakan di beberapa pks ditunjukan di gambar 1. pada tahun 1996, dimulai program langit biru oleh kementrian lingkungan hidup [4], sebagai dampaknya cara mengatasi limbah tandan kosong dengan cara pembakaran dilarang, karena menyebabkan pencemaran udara. sebagai gantinya limbah tandan kosong digunakan sebagai pupuk dan atau bahan baku kompos. akan tetapi pelaksanaannya tidak begitu membuahkan hasil yang baik, bahkan di beberapa tempat diketemukan ketidakefisienan dalam pelaksanaan. pengembalian limbah tandan kosong sebagai bahan baku pupuk alam dan pengganti pupuk buatan ke lahan perkebunan, membutuhkan biaya buruh dan solar untuk pengangkutan, sehingga menjadi beban tambahan. biaya pelaksanaannya tidak dapat mengurangi biaya pembelian pupuk kimia. dari hasil survei yang pernah dilakukan pengawasan pengembalian tandan kosong ke lahan pertanian tidak bisa dilaksanakan secara efektif, umumnya dibuang begitu saja di pinggir jalan, seperti ditunjukkan pada gambar 2 [5]. pelaksanaan pengkomposan juga membutuhkan biaya yang tidak sedikit, sehingga pemanfaatan limbah tandan kosong untuk pupuk dan kompos tidak banyak berlanjut karena gambar 2. pelaksanaan pengembalian limbah tandan kosong ke lahan perkebunan yang tidak efektif. tingginya biaya operasional dan kendala-kendala teknis lainnya. pemanfaatan tandan kosong sebagai bahan bakar boiler menjadi salah satu alternatif pilihan yang banyak dipertimbangkan akhir-akhir ini. proyek pemanfaatan tandan kosong ini biasanya dikaitkan dengan perdagangan karbon melalui mekanisme cdm (clean development mechanism). ini menunjukkan bahwa proyek pltbs (pembangkit listrik tenaga biomasa sawit) yang menggunakan tandan kosong sebagai bahan bakar merupakan proyek yang tidak layak secara keekonomian jika hanya mendapatkan pendapatan dari hasil jual beli listrik. proyek menjadi ekonomis jika ada pendapatan tambahan dari hasil jual beli emisi karbon yang dikurangi dengan beroperasinya pltbs. hal ini bisa menjadi salah satu alasan mengapa proyek pltbs tidak ada sebelum protokol kyoto diratifikasi oleh pemerintah indonesia pada tahun 2004. potensi energi dari tandan kosong ini sangat besar, cukup untuk memberikan kontribusi kekurangan listrik di pulau sumatera. dari 69 pks di sumatera yang dikelola pt perkebunan nusantara (ptpn), yang merupakan bumn (badan usaha milik negara), tercatat potensi 10.000 ton/tahun tandan kosong dan jika dikonversikan ke daya listrik dengan asumsi efisiensi panas 21%, maka limbah tandan kosong tersebut setara dengan pembangkit dengan kapasitas 510 mw [6]. potensi yang besar ini berusaha dimanfaatkan oleh pt pln (persero) dengan melakukan ikatan kerjasama dengan seluruh ptpn yang memiliki perkebunan kelapa sawit di sumatera dan kalimantan. kerjasama ini telah ditandatangani pada bulan januari 2010 [7]. sebagai tindak lanjutnya, setiap ptpn melakukan studi potensi limbah tandan kosong untuk bahan bakar pembangkit listrik tenaga biomass sawit. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 13 b. tujuan tujuan dari studi ini adalah memberikan gambaran/estimasi perihal tingkat kelayakan teknis, nilai ekonomi dan finansial untuk pembangunan pembangkit listrik tandan kosong, atau disebut pembangkit listrik tenaga biomasa sawit (pltbs) di pks pinang tinggi, ptpn vi, jambi. c. waktu dan lokasi penelitian waktu penelitian dilakukan antara bulan agustus 2010 hingga bulan oktober 2010.kandidat lokasi pltbs adalah seluruh pks milik ptpn vi, yang ditunjukkan di tabel 1. terdapat 5 pks, 3 terletak di daerah sungai bahar (sei bahar) dan 2 pks berlokasi di daerah muara bungo. dimana hanya ada 2 pks yang berkapasitas olah tbs (tandan buah segar) sebesar 60 ton/jam. ii. metodologi metodologi penentuan lokasi pltbs mirip dengan penentuan aspek-aspek yang digunakan untuk penentuan lokasi pltu, yaitu sebagai berikut: 1. aspek fisik lokasi aspek fisik lokasi berkaitan dengan kondisi dan karakteristik fisik lokasi yang ditunjukkan oleh kondisi umum, kondisi geologi, kondisi lingkungan dan sarana penunjang yang terletak pada lokasi yang bersangkutan. penilaian aspek ini berdasarkan beberapa faktor di antaranya data seismik (gempa), data hasil survei penyelidikan tanah untuk penentuan kedalaman pondasi tiang bor, serta peta topografi lahan. 2. aspek kelistrikan aspek kelistrikan berkaitan dengan kondisi dan karakteristik yang berpengaruh terhadap masalah kelistrikan yang ditunjukkan oleh parameter jarak terdekat terhadap jaringan transmisi. tabel 1. kapasitas pabrik kelapa sawit. pabrik kelapa sawit kapasitas ton tbs/jam sungai bahar bunut pinang tinggi tanjung lebar 60 60 30 muara bungo rimbo dua ophir 30 50 3. aspek jalan masuk aspek jalan masuk berkaitan dengan kemudahan aksesibilitas lokasi yang akan mempengaruhi biaya transportasi. 4. aspek bahan bakar dan air aspek bahan bakar dan air berkaitan dengan ketersediaan bahan bakar dan air di lokasi tersebut. bahan bakar dalam hal ini adalah limbah biomasa sawit. ketersediaan air selain digunakan untuk umpan pada boiler juga diperlukan sebagai air pendingin pada kondensor. 5. aspek lingkungan aspek lingkungan berkaitan dengan kondisi lingkungan pada saat ini serta dampak yang mungkin timbul dengan didirikannya pembangkit listrik. 6. aspek biaya aspek biaya berkaitan dengan biaya investasi dan biaya operasi pembangkit pada tiap-tiap lokasi yang dipilih, oleh karena itu menjadi faktor yang sangat dominan dalam pemilihan lokasi pembangkit. semua aspek tersebut di atas harus dipertimbangkan sehingga didapatkan lokasi pembangkit yang paling layak dan menguntungkan. namun karena lokasi pltbs berada di dalam area pks maka aspek fisik, aspek jalan masuk dan aspek lingkungan tidak menjadi pertimbangan yang penting. aspek kelistrikan, aspek sumber bahan bakar dan air, dan aspek biaya merupakan tiga faktor yang menjadi inti dari pokok pembahasan dalam laporan studi ini. setelah penentuan lokasi, maka dilakukan analisa data sesuai dengan konsep dasar pembangunanan pltbs, meliputi penentuan konfigurasi fasilitas peralatan pltbs disesuaikan dengan keberlanjutan suplai dari bahan bakar biomasa, tks dan cangkang. dari penetapan kapasitas fasilitas pltbs dilakukan estimasi investasi harga fasilitas peralatan kemudian dilakukan analisa keekonomian. pendapatan dari pltbs berasal dari hasil penjualan listrik ke pt pln (persero), ditambah dengan pendapatan tambahan dari penjualan kredit karbon, penjualan remnant oil dan penjualan abu sisa pembakaran. a. penentuan lokasi seperti ditunjukkan dalam tabel 1, ptpn vi memiliki 5 pks, diantaranya adalah pks bunut dan pinang tinggi, yang berkapasitas 60 ton tbs/jam. dengan dasar pertimbangan jumlah suplai tandan buah segar (tbs) yang maksimal, maka pemilihan lokasi mengarah ke lokasi pks kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 14 berkapasitas 60 ton tbs/jam, yaitu pks bunut dan pks pinang tinggi. dari perencanaan jangka pendek-menengah ptpn vi, diketahui bahwa tks yang dihasilkan di pks bunut akan digunakan untuk bahan baku pembuatan kompos. hal ini berarti limbah tks di pks ini sudah akan termanfaatkan, sehingga jumlah tks yang dapat dimanfaatkan sebagai bahan bakar akan berkurang. sebaliknya di pks pinang tinggi, belum ada rencana pemanfaatan tks. karena itu pks pinang tinggi dipilih sebagai kandidat lokasi pltbs berdasarkan keberlanjutan jumlah suplai bahan bakar tks. dari segi aspek kelistrikan, sampai tahun 2010, rasio elektrifikasi provinsi jambi baru mencapai 51,41% dan rasio desa berlistrik sebesar 99,43%. daftar tunggu pln telah mencapai 31.371 permintaan atau sebesar 92,3 mva, dimana permintaan serta defisit tersebut belum dapat dipenuhi oleh pln dalam waktu dekat [8]. produksi listrik pltbs pinang tinggi ini direncanakan dapat memberikan kontribusi terhadap pemenuhan konsumsi pertumbuhan listrik di propinsi jambi, sekaligus memperbaiki kualitas suplai listrik di sekitar daerah sei bahar, jambi. lokasi pks pinang tinggi, berada di area sekitar 01°57’45” lintang selatan dan 103°24’07” bujur timur. b. jenis dan lokasi sumber bahan bakar bahan bakar untuk pltbs direncanakan berasal dari tks dan kekurangannya berasal dari cangkang. kekurangan bahan bakar tersebut akan disuplai dari pks bunut dan pks tanjung lebar. suplai bahan bakar dari kedua pks dibatasi hanya suplai cangkang saja. suplai tks tidak memungkinkan karena kandungan air tks mencapai sekitar 50%, sehingga dari segi biaya transportasi tidak menguntungkan. dari gambar 3, diketahui hanya posisi kedua pks tersebut yang relatif dekat, berada dalam radius 10 km dari pks pinang tinggi. sedangkan gambar 3. lokasi pks di sekitar pks pinang tinggi. gambar 4. kondisi jalan pada saat musim hujan. pks lain berada di radius lebih dari 20 km yang membuat biaya transportasi sangat tidak menguntungkan. dari hasil survei lapangan diketahui bahwa jarak tempuh dari pks pinang tinggi ke pks bunut berkisar 9 km dengan waktu tempuh ratarata 2 jam. untuk mengangkut cangkang, jarak ini dapat ditempuh oleh truk pengangkut (kapasitas 5 ton) dengan 6 kali pulang-pergi (rit) dalam satu hari kerja. sedangkan jarak tempuh dari pks pinang tinggi ke pks tanjung lebar berkisar 37 km dengan waktu tempuh 6 jam atau 2 kali pulang-pergi (rit) dalam satu hari kerja. waktu tempuh akan menjadi lebih lama karena buruknya kondisi jalan terutama pada saat musim hujan, di beberapa lokasi, kondisi jalan berubah menjadi berlumpur dan berkubang seperti ditunjukkan gambar 4. c. potensi jumlah bahan bakar tujuan pembangunan pltbs adalah untuk memanfaatkan jumlah limbah tks sebagai sumber energi, dan mengurangi biaya pengolahan tks semaksimal mungkin. oleh karena itu direncanakan seluruh tks dapat dimanfaatkan sebagai bahan bakar. akan tetapi karena kendala jumlah tks yang diproduksi pks pinang tinggi tidak mencukupi maka dilakukan pencampuran cangkang seminimal mungkin. transportasi tks dari pks lain dihindari, karena kandungan airnya yang tinggi. suplai tambahan bahan bakar dari pks lain dibatasi hanya cangkang saja. potensi jumlah cangkang dan jumlah tks di pks pinang tinggi ditunjukkan tabel 2. sedangkan potensi jumlah cangkang di pks tanjung lebar dan pks bunut ditunjukkan pada tabel 3. dalam perhitungan diasumsikan hanya 90% dari potensi bahan bakar yang ditunjukkan tabel 2 dan 3, yang dapat dimanfaatkan sebagai bahan bakar. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 15 tabel 2 menunjukkan produksi tks dan sisa cangkang di pks pinang tinggi selama kurun 5 tahun yang lalu. jumlah produksi tks dan cangkang diasumsikan dari rasio tbs sebesar 23% dan cangkang 3,75% [8]. tabel 3 menunjukkan sisa cangkang di pks bunut dan pks tanjung lebar selama 5 tahun berturut-turut dengan asumsi jumlah sisa cangkang adalah 3,75% dari jumlah tbs olah [9]. definisi sisa cangkang dalam studi ini adalah jumlah cangkang yang tersisa dari jumlah cangkang yang dimanfaatkan untuk bahan bakar boiler untuk memproduksi steam dan listrik (existing boiler) di pks. dari tabel 2 ditunjukkan total rata-rata jumlah tks dalam 5 tahun (2005-2009) terakhir yang dapat dimanfaatkan adalah 49.174 ton/tahun, dan dari tabel 2 dan 3, total jumlah sisa cangkang yang dapat dimanfaatkan adalah 21.646 ton/thn (= 8.018 + 7.875 + 5.843 ton/thn). penurunan massa tks akibat penurunan kadar air diasumsikan bahwa pada kadar air 60% massa tks yang dapat dimanfaatkan adalah 49.174 ton/tahun. sebagai perbandingan, igwe memakai asumsi kadar air pada tks 55-65% [10]. nasrin menggunakan nilai asumsi sebesar 67% [11]. tabel 2. produksi tks dan cangkang di pks pinang tinggi. tahun pinang tinggi (ton) tbs tks (23,0 %) cangkang (3,75 %) 2005 235,000 54,050 8,813 2006 223,000 51,290 8,363 2007 173,000 39,790 6,488 2008 202,000 46,460 7,575 2009 236,000 54,280 8,850 jumlah 1,069,000 245,870 40,089 rerata/ tahun 213,800 49,174 8,018 melalui proses pre-treatment, kadar air diturunkan sebesar 66,7% (menjadi kadar air 40%). maka potensi massa tks mengalami penurunan dari 49.174 ton/tahun menjadi 32.782,7 ton/tahun (= 66,7% x 49.174 ton/tahun). d. nilai kalor bahan bakar nilai kalor dari tks ditunjukkan pada gambar 5, dimana tks dapat dibagi menjadi dua jenis, yaitu yang mengandung minyak (oily) dan yang sudah tidak mengandung minyak (pure). (a) (b) gambar 5. hubungan antara oily efb dengan kadar air (a) dan pure efb dengan kadar air (b) tabel 3. produksi cangkang di pks bunut dan tanjung lebar. tahun bunut tanjung lebar tbs cangkang(3,75 %) tbs cangkang(3,75 %) 2005 197,000 7,388 165,000 6,188 2006 216,000 8,100 172,000 6,450 2007 206,000 7,725 146,000 5,475 2008 201,000 7,538 144,000 5,400 2009 230,000 8,625 152,000 5,700 jumlah 1,050,000 39,376 779,000 29,213 rerata/tahun 210,000 7,875 155,800 5,843 y = -213.4x + 18836 r² = 1 5,000 10,000 15,000 20,000 0 10 20 30 40 50 60 70 lh v (k j/ kg ) moisture (%) oily efb y = -202.0x + 17563 r² = 0.999 5,000 10,000 15,000 20,000 0 10 20 30 40 50 60 70 lh v (k j/ kg ) moisture (%) pure efb kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 16 kedua jenis tks ini mempunyai nilai kalor yang berbanding terbalik dengan kandungan kadar air, dimana nilai kalor akan naik dengan berkurangnya kadar air dan pada saat bersamaan jumlah massa tks pun berkurang akibat hilangnya jumlah kadar air yang dikandung tks. hubungan persamaan empiris antara nilai kalor dan kandungan air pada kedua jenis tks ditunjukkan pada persamaan, y= -213,47x + 18.836 untuk tks yang mengandung minyak, dan y= -202,07x + 17.563 untuk tks kering [12]. dalam persamaan ini, x adalah kadar air dan y adalah nilai kalor dalam kj/kg. dari potensi jumlah bahan bakar (tandan kosong dan cangkang) dilakukan estimasi panas yang dihasilkan tiap jam dan estimasi daya listrik yang dibangkitkan dengan memperhitungkan daya listrik untuk konsumsi sendiri. dari nilai penjualan listrik dan pendapatan tambahan lainnya, dilakukan analisa keekonomian dengan faktor-faktor keekonomian yang ditetapkan. e. harga jual listrik harga pembelian tenaga listrik berdasarkan permen esdm no.30/2009[13], ditetapkan sebesar rp 656/kwh x f, jika terinterkoneksi pada tegangan menengah, dimana untuk wilayah sumatera, f = 1,2. dengan demikian, harga jual listrik menjadi sebesar rp 787,2/kwh (= 1,2 x rp 656/kwh). f. pendapatan lain ada tiga jenis pendapatan lain selain penjualan listrik ke pt pln (persero). gambar 6 menunjukkan proses pre-treatment tks dan pemakaian tks untuk memproduksi listrik. dari proses tersebut didapat hasil sampingan yang dapat menambah pendapatan pltbs, yaitu : 1) remnant oil, pada proses pre-treatment dihasilkan minyak pada saat pemerasan (remnant oil). jumlah remnant oil yang didapat, diasumsikan sebesar 0,15% dari jumlah tks. remnantoil yang didapat dari proses pemerasan tks dikembalikan lagi ke dalam proses atau dijual ke pembeli yang menghendaki minyak kelapa sawit kualitas rendah. harga jual remnant oil diasumsikan rp 4.500/kg, atau hampir sama dengan separuh harga crude palm oil. 2) abu hasil pembakaran, dari proses pembakaran tks didapat abu sisa pembakaran. abu ini digunakan untuk pupuk dan dijual ke petani di sekitar pks. jumlah pupuk yang didapat diasumsikan sebesar 2,7% dari total tks yang dibakar. dari survei lapangan harga jual abu senilai rp 800/kg. 3) penjualan karbon, dengan terkoneksinya listrik yang dibangkitkan dari bahan bakar carbon netural atau bahan bakar biomasa ke jaringan grid pt pln (persero)/jaringan interkoneksi sumatera, maka listrik yang dihasilkan dapat mereduksi gas rumah kaca (grk) yang dihasilkan dari pembakaran bahan bakar berbasis karbon (fosil fuel) di pembangkit listrik yang telah terkoneksi dengan jaringan grid tersebut. perhitungan emisi grk yang dikurangi menggunakan emisi faktor jaringan interkoneksi sumatera yaitu 0,743 tco2/mwh [14]. harga karbon sangat berfluktuasi bergantung kepada saat penjualan dan pembelinya, maka diasumsikan antara 15€/tco2 -25 €/t-co2. gambar 6. diagram proses pembangkit listrik tenaga biomasa sawit. steam/water cycle recirculation loop fuel combustion (boiler combustion zone) ash collection steam generation (boiler water tubes) electricity production (steam turbine generator) ash sales electricity sales to grid tks collection &storage tks mousiture & size reduction prepared tks fuel storage oil recovery oil sales river/jba water journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 17 g. perhitungan gas rumah kaca perhitungan grk menggunakan metodologi yang telah ditetapkan oleh unfccc (united nation framework convention on climate chagge). untuk jenis perhitungan grk dalam studi ini, karena listrik yang dibangkitkan terkoneksi ke grid dengan bahan bakar biomasa dan berkapasitas di bawah 15 mw, maka dikategorikan ke type i-d, yaitu renewable energy projects, category d-grid connected renewable electricity generation [15]. untuk menghitung jumlah pengurangan emisi grk yang dapat dihasilkan dari pltbs maka perlu ditetapkan emisi proyek (project emissions), emisi kondisi awal proyek (baseline emissions), dan kebocoran (leakage) berdasarkan persamaan yang ditentukan di metodologi ams id (aprroved methodology small-scale i d) [15], sebagai berikut: ( )ygridygridygridygrid lepebeer ,,,, +−= (1) dimana ergrid,y t-co2/y pengurangan emisi (emission reduction) dalam tahun y begrid,y t-co2/y total emisi kondisi awal (baseline emissions) dalam tahun y pegrid,y t-co2/y total emisi proyek (project emission) dalam tahun y legrid,y t-co2/y total efek kebocoran dalam tahun y emisi proyek, pegrid, dianggap tidak ada (pegrid=0), karena tidak menggunakan bahan bakar fosil. emisi pembakaran hanya berasal dari limbah biomasa (tandan kosong, cangkang dan mungkin serat) yang dikatagorikan zero emission. iii. hasil dan pembahasan dari hasil pengumpulan data di lapangan didapat estimasi jumlah bahan bakar dan estimasi jumlah daya dalam mw yang dapat dihasilkan dari pltbs pinang tinggi ini. a. hasil perhitungan heat and mass balance ketersedian bahan bakar biomasa (tks dan cangkang) yang digunakan sebagai bahan bakar ditunjukkan di tabel 2 dan 3. dalam perhitungan, 90% dari jumlah tersebut dianggap bahan bakar yang tersedia. gambar 7 menunjukkan tekanan, p (bar), suhu, t (oc) dan entalpi, h (kj/kg) di tiap fasilitas peralatan pltbs yang digunakan untuk menghitung heat and mass balance. nilai p, t dan h di tiap fasilias peralatan ditunjukkan di tabel 4. dari perhitungan heat dan mass balance, yang hasilnya ditunjukkan pada tabel 4, didapat beda entalpi dari inlet turbin dan outlet turbin. nilai perbedaan enthalpi ini menentukan kapasitas pltbs. jumlah konsumsi biomasa, masing-masing adalah tks sejumlah 29.519,2 ton/thn (kadar air 40%) dan cangkang sebanyak 21.735,6 ton/thn. jumlah cangkang ini diasumsikan merupakan 90% dari jumlah potensi cangkang pada tabel 1 dan tabel 2. persentase suplai tks dan cangkang adalah 60%:40%. perbandingan ini ditentukan oleh jumlah cangkang yang maksimal hanya bisa mensuplai 40% dari total berat bahan bakar biomasa sawit (cangkang dan tks). jika ketersediaan jumlah cangkang dapat ditingkatkan maka potensi kapasitas mw yang dihasilkan dapat lebih tinggi. akan tetapi karena keterbatasan suplai cangkang maka suplai biomasa dari ketiga pks, yaitu pks pinang tinggi, pks bunut dan pks tanjung lebar dengan jumlah tersebut di atas merupakan jumlah yang maksimal. gambar 7. heat dan mass balance pltbs. tabel 4. disain p, t dan h di pltbs. flow m, ton/jam p, bar t, ºc h, kj/kg kondisi 2 25.2 0.11 47.80 2,442 campuran 3 25.2 0.11 47.80 200 saturated liquid 4 25.2 31.00 47.80 200 subcooled liquid keterangan: p = tekanan, t = suhu, h = entalpi kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 18 dari ketersediaan biomasa tersebut maka kapasitas pltbs maksimal yang didapat adalah 4 mw. kapasitas lebih tinggi membutuhkan suplai bahan bakar terutama cangkang yang lebih banyak dari nilai rata-rata dalam 5 tahun (20052009). kebutuhan tks dan cangkang rata-rata untuk pltbs 4 mw ini adalah 4.100 ton/bulan dan 1.600 ton bulan. dengan asumsi pengoperasian pltbs adalah 7.446 jam (= 8.760jam x kapasitas faktor 85%) dalam setahun, maka jumlah listrik yang dijual ke pt pln (persero) adalah sebesar 4 mw x 7.446 = 29.316 mwh b. konfigurasi fasilitas pltbs gambar 8 menunjukkan konfigurasi peralatan dari pltbs pada studi ini. pada dasarnya konfigurasi fasilitas peralatan pltbs hampir sama dengan fasilitas peralatan di pltu, yang berbeda pada fasilitas peralatan pre-treatment, dimana pada fasilitas ini kadar air tks dikurangi dari 60% sampai 40%. sedangkan cangkang langsung dimasukkan ke dalam tungku bakar, tanpa melalui proses pre-treatment tahapan proses pre-treatment tks sebagai bahan bakar pada boiler pltbs adalah sebagai berikut: 1. tks disalurkan ke dalam sebuah drum pemisah dimana pasir, batu, dan bahan asing lainnya dipisahkan. 2. tks kemudian dicacah dan di-press dalam fibre shredder dan agitator breaker/press dimana kandungan moisture-nya akan berkurang hingga 40%. tks yang keluar dari alat akan berbentuk potongan dengan panjang berkisar antara 20-100 mm. 3. selanjutnya tks disimpan di dalam hopper, sebelum dibakar di unit boiler tunggal. jenis boiler yang digunakan adalah grate stoker boiler dengan kapasitas 4 mw, dengan parameter kerja boiler 30 bar, 300°c dan 30 ton/jam. jenis steam turbine yang dipilih adalah jenis condensing steam turbine. jenis ini dipilih karena mampu memberikan pembangkitan listrik yang maksimum dari steam yang disuplai. exhaust dari steam turbine jenis ini harus dijaga memiliki kualitas di atas 90% karena dryness factor pada steam akan mempengaruhi efisiensi turbin, selain itu juga memacu terjadinya erosi fisik pada blade turbin. untuk steam turbine kapasitas kecil, di bawah 3.000 kw dapat digunakan steam turbinestage tunggal, tanpa ekstraksi. boiler feed pump pompa sirkulasi cooling tower air deaerator tanki kondensat turbin uap boiler generator listrik kondensor uap airtandan kosong(efb) dryer siloefb pressershredder air tambahan untuk boiler pengolahan air umpan boiler sumber air (sungai dll) pengolahan air untuk cooling tower air gambar 8. konfigurasi pltbs. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 19 spesifikasi turbin pada gambar 7 adalah sebagai berikut: a. gross rating : min. 4 mw b. tekanan exhaust perancangan : min. 0,135 bar c. kondisi steam : min. 30 bar /300°c d. kapasitas steam inlet : min. 30 ton/jam e. kondisi steam proses : tidak ada f. estimasi auxiliary power : min. 0,6 mw g. estimasi net outputmaksimal : max. 4 mw h. jenis turbin : condensing, nonreheat,single casing i. speed : 3.000 rpm j. effisiensi : 70% untuk sistem pendinginan kondensat digunakan sistem closed loop cooling, dimana kebutuhan air pendingin untuk mendinginkan air kondensat disirkulasi dan didinginkan di cooling tower. pada saat pendinginan di cooling tower ini terjadi penguapan yang membutuhkan make up water sekitar 5% dari air yang disirkulasikan. estimasi laju alir air pendingin min 1.000 ton/jam. c. analisa keekonomian analisa keekonomian disusun berdasarkan asumsi yang ditunjukkan di tabel 5. sedangkan biaya pengoperasian pltbs terdiri dari biayabiaya yang ditunjukkan pada table 6. tabel 5 asumsi aspek finansial. no parameter nilai satuan 1 faktor inflasi 6 % 2 hutang 70 % 3 equity 30 % 4 bunga 11 % 5 jumlah dipinjam 40.726,8 rp jt 6 equity 17.454,3 rp jt 7 total biaya proyek 58.181,1 rp jt 8 hari produksiper tahun 318 hari 9 produksi listrik 25.316 mwh 10 implementasi proyek 25 tahun tabel 6 biaya pengoperasian. no parameter nilai satuan 1 maintenance 785,7 rp jt 2 asuransi 261,9 rp jt 3 bahan bakar 3658,1 rp jt 4 air dan zat kimia 987,7 rp jt biaya pengoperasian didapat dari bagian teknis pks pinang tinggi berdasarkan data pengoperasian boiler yang ada, yang digunakan untuk suplai listrik dan uap ke pabrik/pks. gaji pegawai tidak diperhitungkan, karena diasumsikan pltbs ini dioperasikan oleh pegawai pks pinang tinggi, yang dianggap telah mempunyai pengalaman dalam mengoperasikan boiler yang sudah ada. pendapatan yang didapat dari hasil penjualan listrik dengan harga rp 787/kwh, menghasilkan pendapatan sebesar rp 19,9 milyar/tahun. nilai irr proyek adalah 2,03%. nilai investasi ini masih berada sangat jauh di bawah nilai irr yang dapat diterima oleh ptpn vi, yaitu 15%. pendapatan tambahan yang berasal dari ke tiga pendapatan tambahan diperhitungkan, sebagai berikut : 1. minyak yang didapat dari pemerasan tandan kosong (remnant oil) sebesar sekitar 199,15 ton/tahun dengan harga diasumsikan rp 4.500/kg. potensi pendapatan remnant oil adalah rp 896,2 juta/tahun. harga minyak yang diperoleh dari tandan kosong diasumsikan naik 6% setiap tahun, sesuai dengan asumsi nilai inflasi. 2. abu sisa pembakaran 5.184 ton/tahun, dengan asumsi harga abu yang diambil di tempat (di pks) dengan harga rp 800/kg, maka didapatkan penjualan abu sebesar rp 4,14 milyar/tahun, dengan asumsi jumlah abu adalah 2,7% dari tandan kosong. harga abu diasumsikan naik 6% setiap tahun, sesuai dengan asumsi nilai inflasi. 3. jumlah pengurangan emisi karbon/grk adalah 19.063 ton co2 per tahun. harga karbon sangat fluktuatif, bergantung kepada saat penjualan dan kondisi pasar karbon, biasanya yang menjadi acuan adalah pasar karbon eropa, dengan acuan harga eua (european union allowance), dimana pada tanggal 21 maret 2011, tercatat harga karbon adalah 16,89 €/t-co2[16]. pada studi ini harga karbon diasumsikan 15 (€/tco2), maka didapat pendapatan sebesar rp 19,92 milyar/tahun. jangka waktu pendapatan dari penjualan karbon adalah kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 20 sama dengan crediting period, yaitu 10 tahun. dari ketiga pendapatan tambahan ini, masingmasing dari penghematan minyak hasil perasan dapat menaikkan irr sebesar 3,03%, dari penjualan abu sisa pembakaran menaikkan irr sebesar 9,03% dan dari penjualan karbon menaikkan irr sebesar 3,79%. total kenaikan irr dari ketiga pendapatan tersebut sebesar 13,09%. sehingga nilai irr dari 2,03% meningkat menjadi 15,12%. batas persyarat keekonomian yang diajukan pihak manajemen ptpn vi adalah 15%. pay back period menjadi lebih cepat, yaitu menjadi 5 tahun. pendapatan tambahan merupakan faktor yang penting untuk kelayakan keekonomian pltbs, karena pendapatan dari penjualan listrik saja memberikan nilai irr yang sangat rendah. tabel 7 menunjukkan hasil analisis sensitivitas dengan mengambil parameterparameter yang memberikan dampak terhadap irr, yaitu nilai investasi, harga jual abu sisa pembakaran, biaya bahan bakar dan harga karbon. penurunan nilai investasi dan harga jual listrik sebesar ±10%, memberikan dampak masingmasing sebesar±1,78% dan ±1,72% dari nilai irr. perubahan biaya bahan bakar dan harga jual abu sisa pembakaran sebesar ±10% memberikan dampak yang hampir sama terhadap perubahan nilai irr yaitu ±0,53%. sedangkan perubahan nilai jual karbon sebesar ±10% memberikan perubahan nilai irr yaitu ±0,26%. sensitivitas proyek sangat dipengaruhi oleh nilai investasi proyek dan harga jual listrik. tabel 7 asumsi aspek finansial. parameter -10% 0 10% investasi 17,24% 15,12% 13,34% abu 14,56% 15,12% 15,65% harga karbon 14,86% 15,12% 15,38% bahan bakar 15,64% 15,12% 14,58% bahan bakar 13.33% 15,12% 16,84% tabel 8 daftar proyek cdm untuk pltbs kelapa sawit di indonesia. nama proyek kapasitas (mw) mss biomass 9,7 mna biomass 9,7 listrindo biomass 12,0 belitung biomass 8,0 nagamas biomass 3 d. perbandingan dengan proyek lain dari proyek pembangunan pltbs yang telah menjadi proyek cdm diketahui bahwa di indonesia ada 7 proyek, dimana 5 proyek yang memanfaatkan limbah kelapa sawit, yang lainnya memanfaatkan limbah kayu dan limbah kelapa [15]. ke-lima proyek tersebut ditunjukkan pada tabel 8. dari keenam proyek, empat proyek pertama menjual produksi listriknya ke pt pln (persero) sedangkan sisanya memproduksi listrik untuk kebutuhan pabrik dan steam untuk proses pabrik pks. skema keekonomian pada nagamas biomass project adalah untuk menggantikan bahan bakar diesel dari pembangkit listrik tenaga diesel yang memakai bahan bakar minyak, sehingga tidak dapat dipakai sebagai perbandingan terhadap pltbs pinang tinggi. dari kapasitas listrik, pltbs pinang tinggi relatif lebih kecil dibandingkan dengan pltbs yang telah beroperasi di indonesia. hal ini berdampak terhadap pendapatan dari produksi listrik maupun penjualan kredit karbon dari produksi listrik yang dihasilkan. walaupun perbandingan harga listrik ke empat pltbs tersebut lebih rendah tetapi perbedaan tersebut tidak sampai kurang dari 70% dari harga jualpltbs pinang tinggi (tidak kurang dari rp 550/kwh). dengan semakin besarnya produksi listrik maka pendapatan dari penjualan kredit karbon semakin besar, sehingga dari ke empat proyek tersebut tidak dibutuhkan pendapatan tambahan selain penjualan kredit karbon untuk menaikkan irr, dari segi investasi, pltbs pinang tinggi relatif lebih mahal dibandingkan dengan pltbs lainnya yaitu usd 1,6 juta/mw karena kapasitas pembangkit yang rendah. sebagai perbandingan adalah nilai investasi pltbs mss senilai usd 1,2juta/mw untuk kapasitas 9,7mw[15] dan usd 1,6 juta/mw untuk 5,92 mw[17]. dengan melihat perbandingan nilai investasi tersebut, dapat disimpulkan nilaiinvestasi pltbs pinang tinggi dapat dinilai cukup layak untuk kapasitasnya. harga jual listrik rp 787/kwh masih terlalu rendah untuk investasi di bidang pltbs. pendapat ini didukung hasil studi yang dilakukan oleh asian development bank pada tahun 2006, terhadap potensi di pks gunung meliau milik ptpn xiii. dengan investasi sebesar usd 9,85 juta untuk membangun pltbs berkapasitas 5,92 mw maka tidak layak secara keekonomian jika harga jual listrik masih berada di bawah 0,08 usd/kwh atau rp 670/kwh[17]. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 1, pp 11-22, 2011 p-issn 2087-3379 21 nilai investasi dari pltbs yang tercantum di tabel 8 tidak bisa didapatkan, akan tetapi dari hasil analisis sensitivitas dapat diduga bahwa investasi tidak semahal pltbs pinang tinggi. oleh sebab itu kelayakan keekonomian dapat dicapai relatif tinggi dan hanya dengan mengandalkan pendapatan tambahan dari penjualan kredit karbon didapat kelayakan keekonomian. pengurangan nilai investasi dapat dilaksanakan dengan mengurangi porsi investasi dari investor dengan menggunakan fasilitas yang telah ada, seperti pemanfaatan pembangkit diesel yang ada untuk kondisi darurat pltbs, pemanfaatan ruang/bangunan untuk menghemat investasi bangunan, sehingga dapat mengurangi porsi investasi dari investor dengan mengalihkan sebagian porsi kecil investasi ke ptpn. investasi pltbs dalam pemanfaatan tks dan cangkang sebagai campurannya tidak dapat sepenuhnya memanfaatkan pendapatan dari penjualan listrik saja tanpa adanya tambahan pendapatan. hal ini berarti investasi pltbs adalah investasi dengan keuntungan yang minim dan resiko karakteristik tks yang mengandung kadar air tinggi dan unsur alkali yang tinggi serta keberlanjutan suplai yang perlu diperhatikan dalam kurun waktu 5-10 tahun ke depan. iv. kesimpulan dari hasil studi kasus pada kelayakan teknologi dan ekonomi pembangunan pembangkit listrik tenaga biomasa sawit (pltbs) di pks pinang tinggi didapat beberapa kesimpulan sebagai berikut: 1. nilai investasi pltbs di pks pinang tinggi dan harga jual listrik sangat menentukan keekonomian proyek. harga jual listrik yang ditetapkan oleh permen 30/2009 masih belum mencukupi untuk mencapai kelayakan proyek pltbs pinang tinggi. 2. kelayakan keekonomian pltbs pinang tinggi menjadi meningkat dengan adanya pendapatan tambahan yang berasal penjualan abu sisa pembakaran, pemanfaatan remnant oil dan penjualan kredit karbon. kontribusi dari pendapatan tambahan tersebut terhadap kelayakan keekonomian akan semakin besar dengan meningkatnya kapasitas pltbs. 3. secara teknis dengan adanya pltbs yang sudah beroperasi, kendala unsur alkali dan kadar air di tks sudah bukan merupakan kendala yang berarti bagi pengoperasian pltbs. ucapan terima kasih ucapan terima kasih ditujukan pks pinang tinggi, pt. perkebunan nusantara (ptpn) 6, yang telah memberikan data-data, informasi serta fasilitas kunjungan lapangan yang terkait dalam pembuatan makalah ini. daftar pustaka [1] kantor menko perekonomian, 2004, "kajian pembiayaan investasi transportasi perkotaan dengan skema debt-for-nature swap,". [2] jan sandberg, christer karlsson, and rebei bel fadhila, 2010, a 7 year long measurement period investigating the correlation of corrosion, deposit and fuel in a biomass fired circulated fluidized bed boiler, applied energy 88 (2011) 99–110, elsevier. [3] michaël becidan, lars sørum, flemming frandsen, and anne juul pedersen, 2009, corrosion in waste-fired boilers: a thermodynamic study, fuel 88 (2009) 595– 604, elsevier. [4] kementrian lingkungan hidup, keputusan menteri kementerian lingkungan hidup no. 15/1996. tentang : program langit biru. [5] study on power project using biomass from palm oil plantation in indonesia, tokyo electric power, institute economic and energy japan & ptpse-bpp teknologi, march 2005. [6] materi presentasi bpp teknologi pada forum diskusi, ptpn 2 biomass feasibility study, hotel sahid jaya, jakarta, 28 february 2011. [7] mou no:06.07/mou/01/2010, ptpn dan pt pln (persero) tentang kerjasama pembelian tenaga listrik oleh pt pln persero dari pembangkit tenaga listrik berbasis biomasa dan/atau energi terbarukan lainnya. [8] kementrian energi dan sumber daya mineral, rencana usaha ketenagalistrikan nasional (rukn) 20082027, jakarta, 2008. [9] pt. perkebunan nusantara (ptpn) vi sumatera barat dan jambi, informasi tertulis dari bagian teknis pks pinang tinggi, jambi, 2010. [10] j.c. igwe and c.c., onyegbado, a review of palm oil effluent (pome) water treatment, global journal of environmental research, 1(2):54-62, 2007 kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi(irhan febijanto) jmev 02 (2011) 11-22 22 [11] a.b. nasrin and et.al, oil palm biomass as potentia substitution raw materials for commercial biomass briquettes production, american journal of applied science 583):179-183, 2008, [12] general guide to consultants, biomassbased grid connected power generation, 2010 [13] kementrian esdm, peraturan menteri esdm no. 30/2009 tentang penetapan dan pemberlakuan standar kompetensi tenaga teknik kelistrikan bidang pembangkitan tenaga listrik sub bagian perancangan, sub bagian perencanaan, sub bagian konstruksi dan sub bagian inspeksi. [14] national commision for clean development mechanism. (2008). pdd and approval letter of cdm projects that have been approved by indonesian dna. [online]. available: http://dnacdm.menlh.go.id/en/database/, diakses tanggal 17 maret 2011. [15] united nations framework convention on climate change. (2011). clean development mechanism [online]. available: http://cdm.unfccc.int/index.html, diakses tanggal 21 maret 2011. [16] point carbon [online]. available: http://www.pointcarbon.com/productsands ervices/carbon/, diakses tanggal 21 maret 2011. [17] project definitian report for waste to energy in poms, gunung meliau cluster, sanggau, west kalaimantan, indonesia, asian development bank, 6 adb avenue, mandaluyong city, metro manila philippines., 2006 j. mechatron. electr. power veh. technol 06 (2015) 57–66 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.57-66 modeling, identification, estimation, and simulation of urban traffic flow in jakarta and bandung herman y. sutarto a, *, endra joelianto b a systems research group, universiteit gent technologie park 913, b-9052 zwijnaarde, belgium b instrumentation and control research group, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia received 6 december 2014; received in revised form 6 april 2015; accepted 8 april 2015 published online 30 july 2015 abstract this paper presents an overview of urban traffic flow from the perspective of system theory and stochastic control. the topics of modeling, identification, estimation and, simulation techniques are evaluated and validated using actual traffic flow data from the city of jakarta and bandung, indonesia, and synthetic data generated from traffic micro-simulator vissim. the results on particle filter (pf) based state estimation and expectation-maximization (em) based parameter estimation (identification) confirm the proposed model gives satisfactory results that capture the variation of urban traffic flow. the combination of the technique and the simulator platform assembles possibility to develop a real-time traffic light controller. keywords: intelligent transportation system; stochastic hybrid system; state/parameter estimation; expectation-maximization; particle filter. i. introduction the application of advanced technologies including computers, electronics, and communications can contribute to traffic conditions improvement, environmental quality enhancement, and economic productivity increase. these technologies, collectively known as intelligent transportation system (its), are rapidly being accepted by transport authorities as a viable alternative to reliance on building more roads to reduce congestion. advanced traffic management systems (atms) in particular have been shown in many experiments around the world to decrease travel times, to improve networks speeds, and to reduce environmental emissions and congestion. however, the benefits of these systems have also been found to be a function of the accuracy and the robustness of the underlying computer algorithms and optimization techniques that provide various levels of intelligence to traffic signal control and operations. one of the its technologies is a coordinated control of traffic lights in an urban area. it proposes good prospects for reducing travel time and pollution due to traffic. the control action that can be used in order to improve the behavior of the system consists of selecting the red-togreen switching times of traffic signals. however, the design of a good (model based) control system, typically, needs a dynamic model that relies on the prior knowledge of a mathematical model that describes the evolution of states and the noise characteristics. therefore, it is necessary to identify or to estimate the parameters of the system model, both offline and online, from the data observed during the operation. the stochastic model must be able to describe the variability over time of the traffic flow, allowing probabilistic prediction of future traffic flows so that control actions by switching traffic lights can anticipate future traffic. anticipation (including prediction) can improve the performance by properly coordinating traffic lights. this requires models that depict the evolution of traffic flow both in time and in space. plant modeling can be either data-driven or based on first principles. data-driven plant modeling uses techniques such as system identification (parameter estimation). with * corresponding author.phone: +62-82130271090 e-mail: hytotok@gmail.com h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 58 system identification, the plant model is identified by acquiring and processing raw data from a real-world system and selects a mathematical algorithm that is used to identify a mathematical model. various kinds of analysis and simulations can be performed using the identified model before it is utilized to design a model-based controller. the need for accurate traffic flow has long been proposed in the international scientific literatures [1,2,3]. numerous methods have been developed especially for freeway traffic state estimation. these methods aim to estimating traffic variables such as flow, speed, and densities for considered freeway network with an adequate time-spatial resolution. this estimation is performed with an assumption based on a limited amount of available noisy measurement data. the methods were almost exclusively based on the macroscopic traffic flow modeling such as by using (extended) kalman filter [4] and particle filter [5]. the macroscopic model depends on some important parameters such as free speed, critical density and capacity, etc. the values of some considered parameters are set as unknown parameters that should be determined by using previous off-line model calibration. the stochastic models with estimated parameters can be used for estimating and predicting traffic flow, and thus also for estimating queue lengths at signalized intersections. the variability of the traffic flow during successive cycles of the traffic light is a prominent factor in predicting the expected queue-length, therefore estimating parameters. establishing model that represents this variability correctly is a challenging problem due to strong coupling between traffic light (discrete events) and traffic flow (discrete time). the discrete event and the discrete time dynamics of such model are coupled, called the stochastic hybrid model. in traffic measurement data, we have to deal with many types of errors. this paper uses data from a video-type sensor to detect the vehicles on the road network of two cities of indonesia, namely jakarta and bandung. noise for this type of sensor includes both false detections and missed vehicles (due to of traffic congestion, counting errors due to night time and obstacles in an urban environment). the paper is aimed to introduce the general overview of modeling, identification/estimation and simulation aspects of urban traffic flow which is then validated using actual traffic flow data. in the simulation parts, vissim is used to simulate traffic flow through the analysis of queueing and fluid flow model. ii. problem formulation in this section, we consider stochastic hybrid modeling of traffic flow along one particular approach route to a signalized intersection, and indicate how this model is useful in controlling the operation of a signalized intersection, explaining why the identification/parameter estimation problem treated in this paper fits into the overall traffic control problem. we may define the evolution of the queuelength by:   t t dtqtq 0 ))()(()()( 0   (1) where ))(()( tt   is the traffic flow rate (generally called )(t so far) of the arrival stream of vehicles (respectively the departure stream of vehicles), measured in veh/sec. as mentioned above, we use the fluid-flow approach, aggregate the number of vehicles during a cycle period, and implicitly assume that during the k -th cycle, between kt and 1kt , the flow rate remains constant, equals to k respectively k . figure 1 shows that intersection i-313 has arrival flow 11l which is determined by using sensor (video camera) output that counts the 313 314 l11 l12 l14 l13 8 9 10 9 6 7 12 d_f_1_3d_f_1_4 d_f_1_1 d_f_1_2 d_f_2_3d_f_2_4 d_f_2_2 d_f_2_1 l22 l23 l24 l21 figure 1. configuration of arterial study h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 59 number of vehicles that passes the sensor location 9, 6, 7, and 12 divided by the cycle length of the intersection i-314. this approach defines the arrival rate )(t . the departure rate for intersection 314, called 11l  , is defined by counting the vehicles that pass the sensor location 8, 9, 10 at downstream intersection i-313, divided by green period of lane 11l at intersection i-313 (the time delay corresponding to the travel time between intersection 313 and 314 must of course be taken into account here). of course this is under the assumption that drivers of vehicles that pass the sensor location 9, 6, 7, and 12 follow the traffic rules. for each intersection, the traffic cycle is divided into two separate periods, called the red and the green periods. for each of the period, only some traffic flows are allowed to cross the intersection so that the departure rate 0)(11 tl whenever traffic in the north-south direction sees red at intersection 313. there are, for each intersection, two decision variables kkg ttt 212   (green period) representing the time duration between switching times kt2 and 12 kt while 1222   kkr ttt (red period) acting between 12 kt and 22 kt . the traffic control signal problem is to determine, for each cycle, good values for these two decision variables by minimizing some cost functions, typically depending on the expected queue-length. the design of a good traffic controller therefore requires that a good model is available to represent the evolution of the arrival and the departure traffic flows, k (a non-negative random process) and k (a non-negative random process that takes the value 0 whenever the traffic light is red for the corresponding direction). the stochastic hybrid model provides the required model. the goal of this paper is to develop an efficient algorithm for estimating the parameters of such model using real data from sensors at the location where the model is to be applied. referring to the simple intersection in figure 1, with one single lane per approach road, let assume that a stochastic hybrid model for the arrival and the departure traffic flows kt  )( for t in k -th cycle, and kt  )( if t in k -th cycle and traffic light green, 0k otherwise. the evolution of k and k is well defined as soon as the parameters of the stochastic hybrid model proposed in this paper have been identified with sufficient accuracy. a complete model for the queue sizes )(tx j for the j -th queue is described in the following equation              otherwisett ttandtxif jtz orjtzift tx jj jjj j j )()( )()(0)(0 4,2,0)( 3,1,0)()( )( 2 1    (2) the operation of the intersection can be modeled as a stochastic hybrid system as shown in figure 2 with the time-driven dynamics described by (1) and the event-driven dynamics dictated by green-red light switches and by events causing some )(tx j to switch from positive to zero or vice versa. the evolution of ])(0,0[ )()( 111 111      tzx ttx ]0)(,0[ )( 11 11    tzx tx  ]0[ 0 1 1    x x 0)( 111  reset ztz  0)( 222  reset ztz  0 1 x 0)()(0)( 111  tttz  0)(0)( 12  ttz  0,0)()( 1111  reset ztandtz  or mode-1 mode-2 mode-3 figure 2. stochastic hybrid automaton h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 60 queue-length with 1n can be described, for example, by a stochastic hybrid automaton as shown in figure 2. the event set that affects the evolution of queue is },,,,{ 54321 eeeeee  , where: (a) 1e corresponds to the value of )()( tt jj   becoming strictly positive (after a period of nonpositive), (b) 2e switches in the sign of )(tj from 0 (zero) to strictly positive or a switch from mode-3 to mode-2, (c) 3e is the queue-length becoming empty, i.e., 0jx or a switch from mode-1 to mode-3, (d) 4e switches a traffic light from red to green or a switch from mode-2 to mode-1, (e) 5e switches a traffic light from green to red or a switch from mode-1 to mode-2. in this paper, we assume that k and k can be approximated by hidden markov model (hmm). in the next section, we further develop this model in detail. in later section, it is then shown how to estimate the parameters of this model by using data-driven approaches. iii. model of traffic flow in this approach, we use fluid flow model [6,7]. the traffic flow is described by a continuous random variable )(t which expresses the number of vehicles passing a given location in the urban network during the time interval ),( dttt  is dtt).( . in order to avoid working with large integers, we fluidize our traffic variables by approximating integer numbers of vehicles by the real number. hence, it can be defined as traffic flow with the ratio: )( 1 kk k k tt n     (3) where kn counts the number of vehicles in the interval ),( 1kk tt . the fluid flow approximation implicitly assumes that the traffic flow remains constant during the interval ),( 1kk tt , i.e. )(tk   for ),( 1 kk ttt . this paper uses macroscopic approach to simplify the complexity of traffic flow. the hidden markov model (hmm) model is also considered in this study. in this section, we model a generic traffic with flow rate kk   (which could represent the arrival flow rate k or the departure flow rate k ). this hmm with gaussian distribution is one of the simplest types of hybrid model. this type of hmm will be studied and used to show that this simple model with the transition probabilities is able to capture the complex phenomena of urban traffic flows. the underlying idea behind hmm is to describe the observed phenomena by two (or more) separate regimes with different statistical properties. here, we use the gaussian distribution to describe the traffic flow distribution (called )(t ) [8]:          2,~)( 1,~)( : 2 222 2 111 sifnt sifnt s    (4) where the traffic flow measurement is described by two separates states (modes) with different underlying properties. the variable denotes the state variable for traffic flow condition ”1” is the non-congestion mode, and ”2” is the congestion mode. the random variable traffic flow is driven by the normal distribution with mean  and variance 2  as parameters. equation (4) implies that statistical properties of the measurement nh depend on the actual state s . the jumping/switching mechanism between states is assumed to be governed by an unobserved markov chain. the discrete transitions are assumed markovian which means the current discrete mode 𝑠 depends only on the mode in the preceding period 1s . this model is completed by defining the transition probabilities of moving from one mode to another denote.     ijnnnn jsisis    11 prpr (5) where 1n is a vector representing all the information available at the time 1n . these transitions can be used to represent the transition matrix ][ ijpp  controlling the behavior of traffic flow. markovian assumption is reasonable since systems frequently exhibit probabilistic patterns in their switching behavior. to illustrate, urban traffic flow changes abruptly during the transition phases of entering or leaving in the rush hours. the hmm system has a framework of multiple modes corresponding to different traffic flow conditions. by defining the parameters   ,, sss  of hmm, the objective is to estimate or to identify the parameters of hmm system (4) by using expectation-maximization (em) technique described in the next section. iv. identification/parameter estimation the parameter estimation can be carried out using an iterative two step em procedure. in this case, the em algorithm allows us to completely identify the hmm stochastic hybrid models proposed in the previous sections as a model for traffic flow. in this section, it is described the h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 61 application of the em approach, originally proposed in [9] and then refined in [8] for switching systems (hmm) based on forwardbackward recursion or ‟smoothing‟. the em approach is formulated in batch or off-line form, i.e. it uses a given number of observations obtained over a time interval ),0( t to iteratively find better and better estimate of the unknown parameters of a model that is valid over the period ),0( t . this offline approach needs a significant memory requirement and processing power for storing and processing large data sets. however, this approach is shown to be useful and applicable further in this paper. estimation of the parameters  of the traffic flow model can be defined for hmm. the parameters of the hmm model are given by  2,1,,,,,, 2211  jiij and the transition probabilities 2,1,, jiij . in this section, it will be briefly discussed the application of the em algorithm for hmm due to limited space. the algorithm starts with an arbitrarily chosen vector of initial parameters   ,,,, 2211 for  2,1s . in the e-step inferences about the state process are derived. since ns is unobservable, only the expected values of the state process given by the observation vector can be calculated. in bayesian inferences, these expectations result in the so called smoothed inferences that represent the conditional probabilities of the process being in modes s at time n . next step is the second step (m-step) maximum likelihood estimates of the parameters vector  based on the smoothed inferences in the e-step. the both steps (e and m steps) are repeated until the maximum of the likelihood function is reached with certain accuracy. the i -th mode weighted loglikelihood function is given by the following formula:                       2 2 2 2 2ln ;|,,ln    ini t n k nnii ispl (6) the two main issues with the implementation of the em algorithm are: (1) the conditional expectation is sometimes difficult to compute. this is the reason for using smoothed inferences which means that we use the whole data (batch) to find more accurate results. (2) the parameter vector converges to a local maximum, a good choice of initial conditions is necessary. in our traffic case, it is simply done by choosing the initial conditions based on the real measurement data. a detailed explanation of the algorithm is given in the following steps. a. the e-step the e-step consists of forward filtering and backward filtering/smoothing. this step aims to calculate the conditional probabilities   knn isp  ;1 . assume that n  is the parameter vector calculated in the m-step during the previous iteration and    ispi  1 0  . 1) forward filtering: for n = 1,2…., n iterate on this equation:                     2 1 1 ;; ;; ; i k ni k nn k ni k nnk nn gisp gisp isp    (7) where  21, n is the vector of traffic flow measurements and   knig  ; is the probability density function at time n conditional on the measured value coming from mode i (here, 1g and 2g are gaussian pdfs as shown in equation (4)); and        knn j k ji k nn isppisp  ;; 2 1 1    until   knn isp  ; is calculated. the starting point for the iteration is chosen as:     kikisp   ;01 . 2) backward filtering for n = 1n , 2n ,…, 1 iterate on                     2 1 1 1 ;| ;|;| ; j k nn k ij k nn k nnk nn jsp pjspisp isp    (8) b. the m-step the new parameter estimates  1k  can be derived by maximizing the log-likelihood function as shown in equation (6). it is straight forward in finding the parameters i and 2 i .               n n k nn n n k nnnik i isp ispf 1 1 ,1 ; ;    (9)                n n k nn n n k nnnik i isp ispg 1 1 ,21 ; ;    (10) where inni ef ,,  and   21,,  kiinni eg  , 2,1i . finally, we have     knki isp  ;11  and the transition probabilities are estimated by using equation (11), with the transition probabilities are restricted only by the condition that 0ijp and 1)...( 321  iniii pppp as shown in [9]. h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 62                             n n k nn n n k nn k nn k ijk nn k ij ip jp ispp jsp p 2 1 2 1 11 1 ;| ;| ;| ;|     (11) where  k ijp is the transition probability from the previous iteration. all values obtained in the mstep are then used as a new parameter vector           11111 ,,,   kikkikik  , 2,1i in the next iteration of the m-step. the algorithm is terminated when       1kk for some small  . v. state estimation as mentioned previously, the paper concerns with hybrid systems. referring to equation (2) to (4) as a complete hybrid model of queue-length evolution, it is clear that the model depends on the arrival and departure flows:  and  . these flows can then be approximated by hmm whose parameters evolve through time according to the mode k s . these parameters of hmm are resulted from em parameter estimation. the state estimation/filtering problem means to look for an estimate of the state x based on the measurements up to the time instant k , which will be denoted by },,,{ 21 kk yyyy  . due to the stochastic nature of the system, the state is a random variable described by the conditional pdf  kyxp . it is important to note that in state estimation, we consider the state not as parameters. in this state estimation, we use pf technique but the pf algorithm is not discussed in detail. the tutorial paper by [11] is a very good introduction to study pf. in this pf, we use parameters of the hmm model identified in the em parameter estimation. in this paper, we develop particle filter (pf) which is one of the approximations of bayesian estimation. pf state estimation of a hybrid system with computationally efficient is the observation and transition-based most likely mode tracking particle filter (otpf) technique proposed in [10]. in state estimation based on otpf, one needs to compute the pdf of the hybrid system: )|,( kkk ysxp , where ks is the mode of the system at time k . the basic idea of otpf algorithm is to look at the mode as an unknown system parameter. since at each time step the system only follows one mode, and then it is reasonable to let it follows the most-likely mode denoted by kŝ , therefore: )|()|( ),|()|(~ ),|()|(),( kkskk kkkkk kkkkkkkk yxpysp ysxpysp ysxpyspysxp k      (12) where )|ˆ( kk ysp is a constant and },,,{ 21 kk yyyy  are the measurements up to the time instant k . from the derivation of equation (12), it can be noted that )|ˆ( kk ysp will be absorbed in the normalization constant and will not affect the basic pf algorithm. thus, the estimation problem for the hybrid system can be solved by using the basic pf [11] after the most likely mode is substituted. the pf in combination with the em offline parameter estimation is a crucial part of the predictor system of the traffic flow. it can be useful and practical for periodically updating the parameters of hybrid model leading to an adaptive traffic flow state estimator/predictor. the interested reader may refer to references [8] for the detail. vi. experimental layout this section focuses on modeling urban traffic flows using parameter estimation techniques. the data set of the experiment layout is shown in figure 1 over a time window ],0[ t . the timewindow size is important in order to define the model that will be used for estimating traffic flow for the next time-window. the effect of varying time-window size and its practical implication on the performance of the estimator will be investigated in the next section. the accuracy of estimated traffic flow is critical for achieving good performance of traffic control strategies. an example of the arrival flow 11l and the departure flow 11l of the intersection i-313 using the data with a one day time-window size to identify the parameters of the flow model as a hybrid system with 3 modes is considered as introduced in the section 2 and 3. the data set was obtained from the sensors of the the sydney coordinated adaptive traffic system (scats) system on jalan thamrin in jakarta. the system includes measurement of the traffic flow as well as the period of the cycle of each intersection. note that the intersections (313 and 314) have a different red/green cycle time. this implies that there is a difference in the time intervals ),[ 1n k n k tt , 313n or 314n , which are used for measuring 11l and 11l . let m kn be the number of vehicles passing sensor location m ( m = 6, 7, 9, 12 at intersection 314n ; m = 8, 9, 10 at intersection 313n ) during the time intervals h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 63 ),[ 1n k n k tt , 313n or 314n , then l11 k = (n7,314 k + n8,314 k + n9,314 k + n12,314 k )/(tk+1 314 tk 314 ), and l11 k = (n8,313 k + n9,313 k + n10,313 k )/(tk+1 313 tk 313 ). note that the k -th sample for arrival and for departure flows does not in general correspond to the same physical time t . the paper only focuses on the study of the development and the validation of a model of traffic flow as a hybrid system. the experiment is aimed to model the traffic flows using hmm characterized by parameters shown in equation (2) to (4). the objective of next experiment is to model the considered traffic flow using hmm. the model is characterized by parameters   ,, sss  which are mean and variance of traffic flow in each mode, and transition probabilities. in this experiment, there are two cases: case 1 is a case of an urban traffic flow of the city of jakarta with the configuration and location is shown in figure 1. the data are taken from september 1 to september 8, 2012. it is important to note that the data consist of not only the traffic flow but also the duration of cycle of each intersection. in this case, we consider a departure flow l11 of i-313. in this case, the traffic flow is defined as a number of vehicles passing to the lane number 8, 9 and 10 of l11/green duration of i-313. whereas case 2 is a case of incoming flow to urban network on the city of bandung is considered. the data were taken at 15 minutes time interval during june 11 to june 13, 2012. the data were gathered from 0:00 am to 24 pm on each day. in this case, the traffic flow is defined as a number of vehicles passing the specific lanes during 15 minutes. using the em-technique as shown in previous section, we can find the parameters of the model for the traffic flow of the two cases as shown in table 1. it is clear that the em technique is able to identify the modes. although this hmm is a simple model, as shown in figure 3, the model can capture the complexity of the traffic flow. a capability to identify the mode is represented by the results of estimated probabilities for that measurement data nh being in specific mode j at time n , such as mode 1 or mode 2. this capability is very important to capture the transition phenomena in traffic flow. overall, the em algorithm with hmm is able to correctly identify clusters of mode-1or mode-2. the parameters in table 1 are used to carry out one-step-ahead prediction, but we only do validation for the case 2 with 15 minutes time update. the particle filter (pf) technique will be applied to validate the model and to estimate the traffic flow under the assumption that the parameters of the underlying hmm model are known correctly. as shown in previous section, the objective of optimization in the em algorithm is to find the parameters of the hmm through maximization the log-likelihood function defined in equation (6) with respect to the underlying unknown parameters. case 2 is the case for 15 minute updated traffic flow and compared with measurement/ observations on june 13, 2012. it is important to note that the parameters in table 1 were built based on the measurement data on june 11-12. for prediction, we used measurement data on june 13. figure 4 shows that the proposed model is able to capture the complex phenomena with satisfactory results except around index 80 th . this result confirms that the model is applicable to this case. vii. traffic simulation the increasing power of computer technologies, the evolution of software engineering and the advent of the intelligent transport systems (its) have prompted traffic simulation to become one of the most used approaches for traffic analysis in support of the design and evaluation of traffic systems. the ability of traffic simulation to emulate the time variability of traffic phenomena makes it a unique tool for capturing the complexity of traffic systems. microscopic traffic simulation based on the emulation of traffic flows from the dynamics of individual vehicle is becoming one the most attractive approaches. the paper is not intended to explain the simulator in detail. the interested reader may refer to documents of vissim. however, in this paper, traffic simulator vissim will be used to analyze traffic flow in urban network, especially in the signalized intersection context. we use vissim microscopic traffic simulator to create a hypothetical network to test the proposed bayesian pf estimator (part of control strategies) at a network level. the studied network is a single grid type intersection. the length of each link is 300 meters with two-way roads exist in this network to simulate the typical situation of an urban network. the features or the characteristics of the simulation are described below. the desired speed distribution used in this exercise was 35 to 65 kph. this value was chosen based on prior experience with vissim and by default, we considered one vehicle occupies the full width of one lane in vissim. the signals in the network are set to fit the configuration of the intersection. there are twoh.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 64 phased signals. the signal is modeled as fixed controlled with duration of each phase is fixed for minimum green time to a maximum green time. the cycle length is set to 80 seconds with green duration is 35 seconds, amber duration is 3 seconds and all-to-red is 2 seconds. the traffic demand of this network is an input in the form of od matrices. the vehicle flow of generation origin is 0.16 vehicle/second and the simulation time interval is 3,600 seconds. there are „zones‟ located at the periphery of the network, and the od matrix is defined as zone to zone demand. from the links associated with these zones, vehicles are released into the network. in vissim simulator: (a). a vehicle is in queue condition if its speed is less than the begin speed and has not exceeded the end speed yet; (b). current queue length is measured upstream every time step. from these values, the arithmetical average is computed for every time interval. by that definition and hybrid model of the queue-length in equation (2, 3, 4), the cumulative numbers of vehicles traversing sensor locations (e.g. af-4 and df-4) are recorded w.r.t traffic signal sequence which therefore refer to ggk t., , rrk t., , and ggk t., . based on that, the pf algorithm can then be applied to estimate the queue length. the ‟actual‟ queue length (by vissim) can be recorded by putting the queue counter in the front of stop-line at the end of every red light (cycle-by-cycle). in this case, we set and used type of „average‟ of the queuelength. figure 5 shows that the particle filter estimator gives a similar result compare to the table1. parameter estimation results case 1: case 2: n s = 1 ns = 2 ns =1 n s =2  = 0.2174  = 0.6806  = 115.78  = 471.16 2  = 0.014 2  = 0.044 2  = 6.3762e+003 2  = 4.3072e+003 transition probabilities        0.98750.0125 0.01320.9868  transition probabilities        0.98080.0192 0.02390.9761  figure 4. predicted flow versus observed flow 0 10 20 30 40 50 60 70 80 90 100 0 100 200 300 400 500 600 each 15 minute # v e h ic le d u ri n g 1 5 m in u te -: estimation based on parameter model of june 11-12 --: measurement based on the data on june 13 h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 65 both approach of vissim. figure 6 shows the example of the visualization of signal time table and measuring data (veh) in each detector in vissim. viii. conclusion the paper presents an overview of the application of modeling, identification, estimation, and simulation techniques for urban traffic flows. the application confirmed that the proposed model gave satisfactory results which captures the variation of traffic flow. the technique together with simulator platform create the possibility to develop a real-time traffic light controller. by describing the urban traffic flow in the perspective of system and control theory, we encourage the control community to explore the figure 5. queue length estimation in vissim figure 6. visualization in vissim 0 5 10 15 20 25 30 35 0 10 20 30 40 50 60 70 cycle index c y c le -b y -c y c le q u e u e l e n g th ( m e te r) pf estimation vissim average queue length vissim cumulative veh w.r.t traffic signal sequence h.y. sutarto and e. joelianto / j. mechatron. electr. power veh. technol 06 (2015) 57–66 66 ideas and perspectives for its community. the big problem in its is how to develop the coordinated control for large-scale urban network and for that the control community has a big opportunity to offer a better solution. acknowledgement the work of the first author was supported in part by european community‟s seventh framework programmed under project disc (grant agreement n.infso-ict-224498). the authors would like to gratefully acknowledge ir. agoes suwardi and ir. rosyad from p.t. newtel, bandung, and also ir. zulkarnaen zakaria, m.eng. from p.t. general intelligent technology, bandung for their helpful discussion and assistance of the measurement data. the first author would also like to specially acknowledge em.prof. rené k. boel at universiteit gent for deep and helpful discussion and having an eye for the details and also aditya nugroho, senior engineer at surbana international consultans pte. ltd., singapore and also prof. budi yulianto from universitas sebelas maret, solo for their assistance and cooperation in running vissim simulator. this work is also supported by the research and innovation program, institut teknologi bandung, 2012. references [1] w.y. ming, et al., “user needs in green its: results of a questionnaire survey and proposal for green its design,” inter. j. intell. transport. syst., 10, 47–55, 2012. [2] w. liu, et al., “decision-making analysis on urban transportation planning based on improved gra model,” inter. j. app. math. stat., 48(18), 136-142, 2013. [3] j. zheng, “simulation model for transportation flows and its nexus to economic growth under small sample,” inter. j. app. math. stat., 52(3), 90-99, 2014. [4] y.b. wang, et al., “an adaptive freeway traffic estimator,” automatica, 45(1), 10-24, 2009. [5] l. mihaylova, et al., “freeway traffic estimation within particle filtering framework,” automatica, 43, 290-300, 2007. [6] h.y. sutarto and r.k. boel, “hybrid automata model approach for coordinating traffic signal control,” 29 th benelux meeting on systems and control, heeze-netherland, 2010. [7] c.r. vasquez, et al., “hybrid petri net model of a traffic intersection in a urban network,” ieee multi-conference on systems and control, yokohama, japan, sept 2010. [8] h.y. sutarto and e. joelianto,“expectation maximization based parameter identification for hidden markov model of urban traffic flow,” inter. j. app. math. stat., 53(2), 90101, 2015. [9] j.d. hamilton, “analysis of time series subject to change in regime,” journal of econometrics, 45,39-70,1990. [10] s. tafazoli and x. sun, “hybrid system state tracking and fault detection using particle filter,” ieee trans. on control system technology, 14(6), 2006. [11] b. ristic, et al., “beyond the kalmanfilter,” artech house, 2004. kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 85-94, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.85-94 perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 dc brushless motor control design and preliminary testing for independent 4-wheel drive rev-11 robotic platform roni permana saputra, rizqi andry ardiansyah, midriem mirdanies, arif santoso, aditya sukma nugraha, anwar muqorobin, hendri maja saputra, vita susanti, estiko rijanto pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia. permana.saputra@yahoo.co.id diterima: 18 november 2011; direvisi: 25 november 2011; disetujui: 12 desember 2011; terbit online: 22 desember 2011. abstrak makalah ini membahas tentang desain sistem kendali motor dc brushless menggunakan microcontroller atmega 16 untuk diimplementasikan pada independent 4-wheel drives pada platform mobil robot lipi versi 2 (rev-11). sistem kendali yang dibuat terdiri dari 2 bagian yaitu modul kendali motor dc brushless dan kendali supervisor yang berfungsi untuk mengoordinasi perintah ke modul-modul kendali motor. untuk mengendalikan platform rev-11, kendali supervisory mengirimkan data referensi berupa kecepatan dan arah pada modul kendali motor sebagai referensi untuk mengendalikan kecepatan dan arah dari masing-masing aktuator pada platform rev11. dari hasil pengujian disimpulkan bahwa sistem kendali yang didesain sudah mampu berfungsi dengan baik untuk mengkoordinasi dan mengendalikan kecepatan dan arah gerak motor aktuator platform rev-11. kata kunci: motor dc brushless , microcontroller, mobile robot, kontrol supervisory, kontrol gerak. abstract this paper discusses the design of control system for brushless dc motor using microcontroller atmega 16 that will be applied to an independent 4-wheel drive mobile robot lipi version 2 (rev-11). the control system consists of two parts which are brushless dc motor control module and supervisory control module that coordinates the desired command to the motor control module. to control the rev-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform rev-11. from the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor rev-11 platform. keywords: brushless dc motor, microcontroller, mobile robot, supervisory control, motion control. i. pendahuluan robot merupakan contoh klasik produk mekatronik yang dikenal banyak orang pada umumnya. mekatronik sendiri secara keseluruhan di indonesia belum banyak dikenal. untuk membuat suatu robot diperlukan berbagai bidang keilmuan yang meliputi teknik mesin, teknik elektro, teknik kendali, teknik komputer, teknik komunikasi, dan pengolahan citra [1]. akhirakhir ini telah banyak dilakukan penelitian di bidang robotika baik di level akademisi, mahasiswa, dan peneliti, termasuk negara kita indonesia yang juga turut berperan dalam penelitian dan berinovasi dalam pembuatan robot [2]. selain itu, banyak juga dilakukan konteskontes robot di level pelajar dan mahasiswa, terutama yang lebih menekankan pada aspek algoritma kecerdasan buatan [2]. sesuai dengan tugas dan fungsi pokok pusat penelitian tenaga listrik dan mekatronika (p2 telimek), untuk meningkatkan kompetensi bidang mekatronik, p2 telimek telah dan sedang melakukan penelitian dan pengembangan robotika, khususnya robot untuk aplikasi pertahanan dan keamanan. pada tahun 2009 telah dihasilkan satu contoh produk mobil robot lipi versi pertama (mrv-1) yang memiliki kemampuan menaiki tangga dan melewati tanggul. robot ini mampu menaiki tangga dengan kemiringan 15° dan melewati tanggul setinggi 10 cm. robot ini memiliki dimensi 190 x 190 x 190 cm dan berat 190 kg. dengan dimensi http://dx.doi.org/10.14203/j.mev.2011.v2.85-94 perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 (roni permana saputra, et. al.) jmev 02 (2011) 85-94 86 yang besar ini, robot sulit bermanuver di ruang sempit dan karena bobotnya yang berat, mrv-1 sulit diangkut sehingga menghambat mobilitas. platform mrv-1 memiliki drive train mechanism berupa mekanisme roda, trase dan ramp. mekanisme ini digerakkan menggunakan motor dc. sistem kendali yang diterapkan baru menggunakan kendali arus analog. pada tahun 2011, p2-telimek melakukan kembali penelitian rancang bangun robotik hankam. pada penelitian ini, dilakukan penyempurnaan desain mobil robot lipi yang baru untuk menghasilkan contoh produk baru mobil robot lipi versi kedua (rev-11). perbedaan robot ini dengan versi sebelumnya terletak pada desain sistem mekanik platformnya yang berdimensi lebih kecil dan lebih ringan. selain itu, sistem penggerak platform pada robot ini juga berbeda dengan versi sebelumnya yang menggunakan motor dc dengan kendali analog. pada rev-11, sistem penggerak platform menggunakan 4 motor dc brushless dengan kendali digital. penggunaan motor dc brushless memiliki keuntungan efisiensi yang lebih tinggi dibandingkan motor dc karena tidak menggunakan sikat sehingga tidak ada rugi gesekan. selain itu motor dc brushless memiliki konstruksi yang lebih sederhana dan coil yang terletak sebagai stator yang terpasang pada body sehingga proses pendinginan lebih baik [3]. makalah ini membahas tentang desain dan pengujian sistem kendali motor dc brushless menggunakan microcontroller atmega 16 untuk diimplementasikan pada independent 4-wheel drive pada platform mobil robot lipi versi 2 (rev-11). ii. perancangan sistem sistem ini terdiri dari perangkat keras dan perangkat lunak. perangkat keras berupa sistem rangkaian elektronika dan rangkaian digital yang terintegrasi untuk melakukan pengendalian terhadap aktuator dari sistem penggerak rev-11. dalam penelitian ini, aktuator yang dikendalikan berupa motor dc brushless produk oriental motor. penggunaan motor dc brushless dilakukan dengan pertimbangan bahwa unit motor dc brushless memiliki fitur sebagai berikut [4] : 1. memiliki efisiensi yang tinggi karena menggunakan rotor permanen magnet dan rugi-rugi sekunder yang kecil. 2. inersia rotor dapat dikurangi, dan diperoleh respon kecepatan yang tinggi. 3. karena efisiensinya tinggi memungkinkan mengurangi ukuran motor menjadi lebih kecil 4. fluktuasi kecepatan akibat perubahan beban kecil. perangkat keras sistem pada penelitian ini terdiri dari rangkaian sistem microcontroller, driver motor dc brushless, dan modul digital to analog converter (dac). adapun perangkat lunak berupa algoritma kendali pada microcontroller yang terdiri dari algoritma kendali supervisor dan algoritma kendali motor. diagram blok dari sistem kendali digital ini ditunjukkan pada gambar 1. gambar 1. diagram blok sistem kendali platform rev-11. supervisory mikrokontroller atmega16 input dataserial a1 a2 a3 a4 a5 a6 a7 a8 k2 k3 k4 k5 k6 k7 k8k1 v2 v3 v4 v5 v6 v7 v8v1 d2 d3 d4d1 modul wireless rotarymeter atmega 8 driver motor dc 1 motor dc 1 rotary encoder m ikrokontroller a t m ega16 θ ω rst a b driver motor dc 2 motor dc 2 kontrol motor trase kanan d a c z data kontrol kontrol m2 input data input kontrol kontrol m1 kontrol m1 kontrol m2 d1 d2 d3 d4 k3 output verifikasi v3 supervisory rotarymeter atmega 8 driver motor dc 1 motor dc 1 rotary encoder m ikrokontroller a t m ega16 θ ω rst a b driver motor dc 2 motor dc 2 kontrol motor trase kanan d a c z data kontrol kontrol m2 input data input kontrol kontrol m1 kontrol m1 kontrol m2 d1 d2 d3 d4 k4 output verifikasi v4 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 85-94, 2011 p-issn 2087-3379 87 gambar 1 menunjukkan bagian kendali supervisory yang menerima data dari wireless, kemudian mengoordinasikan kendali motor pada wheel drive kanan dan kiri dan mengirimkan data kecepatan serta arah putaran ke masingmasing kendali motor. data dikirimkan pada port yang sama di bagian supervisory kendali dalam bentuk sinyal pulse width modulation (pwm) untuk semua modul kendali motor. penerima data dibedakan dengan memberikan port penanda yang berbeda untuk masing-masing modul kendali motor. a. perangkat keras sistem pengendali perangkat keras sistem pengendali ini berupa microcontroller dan rangkaian elektronika digital yang terintegrasi untuk melakukan pengendalian aktuator. aktuator yang dikendalikan berupa empat motor dc brushless independent yang masing-masing menggerakkan sistem roda platform. pada gambar 2, ditunjukkan konfigurasi motor dc brushless pada platform rev-11. aktuator yang digunakan pada sistem penggerak rev-11 berupa empat motor dc brushless produksi oriental motor. pada gambar 3 ditunjukkan motor dc brushless oriental dan driver penggeraknya. pengendalian motor ini dilakukan dengan mengendalikan konfigurasi pin gambar 2. konfigurasi motor dc brushless pada sistem penggerak platform rev-11. (a) (b) gambar 3. aktuator platform robot rev-11 [5]. (a) motor dc brushless, (b) driver penggerak motor. input pada driver motor. untuk mengatur kecepatan motor, dilakukan dengan memberikan input analog pada pin vrh dan mengkonfigurasi pin int vr / ext input pada posisi ext input. pada gambar 4 ditunjukkan konfigurasi pin i/o pada driver penggerak motor dc brushless oriental [6]. perangkat keras sistem kendali digital yang dibuat berupa modul kendali motor dan satu buah modul kendali supervisor. modul sistem kendali digital ini menggunakan microcontroller atmega16 yang mampu menyimpan memori sebanyak 16 kbyte dan memiliki 32 pin i/o [6][7][8]. skema rangkaian modul sistem kendali yang dibuat ditunjukkan pada gambar 5 dan perangkat keras modul sistem kendali yang telah dibuat ditunjukkan pada gambar 6. b. algoritma perangkat lunak sistem kendali perangkat lunak sistem ini terdiri dari dua bagian, yaitu perangkat lunak di microcontroller sebagai supervisor dan sebagai sistem pengendali aktuator. gambar 7 menunjukkan diagram alir perangkat lunak di microcontroller sebagai kendali supervisor. microcontroller supervisor menerima data posisi dan kecepatan semua aktuator dari pengaturan operator melalui modul wireless. data yang diterima akan dibagikan ke masingmasing modul kendali aktuator untuk dijadikan sebagai update data referensi masing-masing aktuator. data referensi tersebut dikirimkan secara berkala ke semua modul kendali aktuator. pengiriman data tersebut dilakukan dengan metode pwm. port data yang digunakan untuk gambar 4. konfigurasi pin i/o pada driver penggerak motor dc brushless oriental [5]. 4 motor dc brushless perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 (roni permana saputra, et. al.) jmev 02 (2011) 85-94 88 (a) (b) gambar 5. skema rangkaian elektronik kendali supervisory. (a) rangkaian kendali supervisory (b) rangkaian kendali digital motor dc brushles. (a) (b) gambar 6. perangkat keras modul sistem kendali digital yang dibuat. (a) rangkaian kendali supervisory (b) rangkaian kendali digital motor dc brushless. mengirimkan data pwm ke semua modul kendali menggunakan port yang sama. pengiriman ke masing-masing modul kendali dilakukan secara bergantian dan berurutan pada frekuensi tinggi. untuk membedakan peruntukan data pada masing-masing modul kendali digunakan port penanda yang berbeda pada masing-masing modul kendali. jika port penanda suatu modul bernilai high, maka modul tersebut harus membaca data pwm yang dikirim modul supervisor. selain port penanda, terdapat pula port verifikasi yang berbeda untuk masingmasing modul kendali yang digunakan untuk memberikan tanda pada modul supervisor bahwa modul kendali tersebut telah selesai membaca data yang dikirim modul supervisor. algoritma perangkat lunak di microcontroller sebagai modul kendali motor ditunjukkan pada gambar 8. pada modul kendali motor, microcontroller menerima data referensi dari modul supervisor berupa data pwm. modul kendali akan membaca data pwm dari supervisor jika pin kendali pada modul tersebut bernilai high. setelah modul kendali selesai membaca data pwm, modul kendali akan mengirimkan sinyal acknowledgement ke modul supervisor sebagai verifikasi. data yang diterima dari supervisor digunakan untuk meng-update referensi sudut dan kecepatan aktuator yang dikendalikan. jika data posisi aktual aktuator berbeda dengan nilai referensi, maka modul kendali akan mengatur run brake motor aktuator journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 85-94, 2011 p-issn 2087-3379 89 gambar 7. algoritma perangkat lunak kendali di microcontroller sebagai kendali supervisor. gambar 8. diagram alir perangkat lunak kendali di pc. sampai posisi aktual aktuator sesuai dengan nilai referensi. untuk mengendalikan kecepatan aktuator, modul kendali akan menaikkan atau menurunkan kecepatan sampai nilainya sama dengan nilai referensi kecepatan. iii. hasil pengujian dan pembahasan pengujian awal yang dilakukan pada sistem elektronik dan kendali ini meliputi uji fungsi pin input kendali pada driver motor, uji pembacaan sinyal umpan balik kecepatan dari motor, uji fungsi perangkat keras modul sistem kendali digital yang telah dibuat, pengujian fungsi kendali supervisor, dan pengujian fungsi kendali motor aktuator. uji coba fungsi pin input kendali pada driver motor dc dilakukan dengan mengkonfigurasikan dan memberikan input pada pin kendali driver motor. koneksi dan konfigurasi pada pengujian fungsi pin input kendali pada driver motor ditunjukkan pada gambar 9. proses pengujian fungsi pin input kendali pada driver motor gambar 9. koneksi dan konfigurasi pada pengujian fungsi pin input kendali pada driver motor. ditunjukkan pada gambar 10. berdasarkan pengujian semua pin input berfungsi dengan baik. hasil pengujian i/o driver motor dc brushles ditunjukkan pada tabel 1. uji coba pembacaan sinyal umpan balik kecepatan motor, dilakukan dengan memberi pull up pada sinyal keluaran perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 (roni permana saputra, et. al.) jmev 02 (2011) 85-94 90 umpan balik kecepatan motor, kemudian dibaca oleh osciloscope dan ditampilkan di komputer. koneksi dan konfigurasi pada pengjian fungsi pembacaan sinyal umpan balik kecepatan motor ditunjukkan pada gambar 11. hasil pembacaan sinyal umpan balik kecepatan motor ditunjukkan pada gambar 12. selain menggunakan oscilloscope, pengujian sinyal umpan balik kecepatan motor juga dilakukan dengan mengukur secara analog tegangan pada output umpan balik kecepatan motor dengan menggunakan multimeter. untuk memvariasikan kecepatan motor, dilakukan dengan melakukan perubahan input analog secara berkala antara 0 sampai dengan 5 volt pada pin vrm pada driver motor. hasil pengujian output umpan balik kecepatan motor dc brushless ditunjukkan pada tabel 2 dan gambar 13. tabel 1. hasil pengujian pin i/o driver oriental motor dc brushless. nama pin kondisi 1 kondisi 2 kondisi 3 kondisi 4 start/ stop on on on off run/ brake on on off on cw/ ccw on off off off hasil motor berputar searah jarum jam motor berputar berlawanan jarum jam motor berhenti seketika motor berhenti karena inersia gambar 10. proses pengujian fungsi pin input kendali pada driver motor. gambar 11. koneksi dan konfigurasi pada pengujian fungsi pembacaan sinyal umpan balik kecepatan motor. gambar 12. hasil pembacaan sinyal umpan balik kecepatan motor menggunakan oscilloscope. r sinyal umpan balik dari driver motor dibaca osciloscope v < 26 volt i < 1 0 m a low speed high speed journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 85-94, 2011 p-issn 2087-3379 91 tabel 2. hasil pengujian output umpan balik kecepatan motor dc brushless. input analog (volt) lebar pulsa low (ms) lebar pulsa high (ms) tegangan output analog (volt) kecepatan motor (rpm) 1 30 248 4,46 600 2 30 119 3,99 1.200 3 30 84 3,68 1.800 4 30 54 3,21 2.400 5 30 34 2,66 3.000 gambar 13. hasil pengujian output umpan balik kecepatan motor dc brushless. untuk mengetahui unjuk kerja fungsi modul kendali supervisor yang telah dibuat pada gambar 6, pengujian fungsi kendali supervisor dilakukan dengan menghubungkan modul kendali supervisor dengan dua modul kendali aktuator untuk menguji fungsi koordinasi dan pengiriman data ke masing-masing modul kendali aktuator. kemudian pada masing-masing modul kendali aktuator, data yang diterima dari modul supervisor ditampilkan untuk disesuaikan dengan input data yang dikirim modul supervisor. pada gambar 14 ditunjukkan proses pengujian fungsi kendali supervisor. hasil pengujian distribusi data kendali supervisor ke modul kendali motor ditunjukkan pada tabel 3. dari tabel 3 dapat dilihat modul kendali aktuator hanya akan membaca dan meng-update data referensi dari modul supervisor jika pin kendali pada modul tersebut bernilai high. berdasarkan hasil ini, modul supervisor sudah mampu untuk membagi dan mengkoordinasikan data ke masing-masing modul kendali aktuator. konversi pembacaan data yang dikirim oleh kendali supervisor pada modul kendali motor ditunjukkan pada gambar 15. gambar 15 menunjukkan konversi pembacaan data yang dikirim oleh modul kendali supervisor oleh modul kendali motor mengikuti persamaan (1): d = 0,694 x + 0,446 (1) gambar 14. pengujian fungsi kendali supervisor. gambar 15. konversi pembacaan data oleh modul kendali motor. y = -0.082x + 255.7 r² = 0.847 y = -0.000x + 4.914 r² = 0.992 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 50 100 150 200 250 300 0 1000 2000 3000 te ga ng an o ut pu t ( vo lt ) le ba r p ul sa h ig h (m s) setting kecepatan (rpm) lebar pulsa high output tegangan umpan balik y = 0.694x + 0.446 r² = 1 0 50 100 150 200 0 100 200 300 h as il ba ca m od ul k on tr ol m ot or data pwm dari kontrol supervisor perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 (roni permana saputra, et. al.) jmev 02 (2011) 85-94 92 tabel 3. hasil pengujian distribusi data kendali supervisor ke modul kendali motor. data pwm yang dikirim pin kendali modul 1 pin kendali modul 2 hasil baca modul 1 hasil baca modul 2 0 high high 0 0 32 low low 0 0 64 low high 0 45 128 low high 0 89 255 high low 177 89 0 low high 177 0 32 high low 23 0 64 high high 45 45 128 low low 45 45 255 high low 177 45 pada persamaan (1), dengan nilai r2 = 1 dan nilai r menunjukkan bahwa linearitas pembacaan data oleh modul kendali motor dalam kondisi baik. pengujian pengendalian i/o driver motor oleh modul kendali motor dilakukan dengan menghubungkannya pin out di microcontroller untuk mengendalikan gerakan motor dengan mode cw/ccw, start/stop, dan run/brake menggunakan microcontroller. selain itu dilakukan pengujian fungsi kendali kecepatan dan kendali posisi motor berdasarkan input yang dimasukkan. proses pengujian fungsi perangkat keras modul sistem kendali digital motor ditunjukkan pada gambar 16 dan hasil pengujian fungsi perangkat keras ditunjukkan pada tabel 4. berdasarkan tabel hasil pengujian, fungsi modul kendali aktuator untuk memberikan input kendali pada pin-pin kendali pada driver motor dc brushless dapat berfungsi dengan baik. response time sistem untuk variasi perubahan setting kecepatan ditunjukkan pada tabel 5. dari tabel 5 dapat dilihat bahwa variasi perubahan nilai setting kecepatan tidak berpengaruh signifikan terhadap response time dari sistem. gambar 16. pengujian fungsi perangkat keras modul sistem kendali digital motor. tabel 4. hasil uji coba fungsi perangkat keras modul sistem kendali digital. nama pin kondisi 1 kondisi 2 kondisi 3 kondisi 4 start/ stop low low low high run/ brake low low high low cw/ ccw low high high high hasil motor berputar searah jarum jam motor berputar berlawanan jarum jam motor berhenti seketika motor berhenti karena inersia tabel 5. response time sistem untuk variasi perubahan setting kecepatan. perubahan setting kecepatan ∆v (volt) response time (ms) rata-rata response time (ms) 1 (51) 0,632 0,66 2 (102) 0,6 3 (153) 0,72 4 (204) 0,67 5 (255) 0,692 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 85-94, 2011 p-issn 2087-3379 93 iv. kesimpulan pada penelitian ini, telah dihasilkan sistem pengendali digital motor dc brushless menggunakan microcontroller atmega 16 untuk diaplikasikan pada aktuator platform mobile robot rev-11. berdasarkan hasil pengujian awal dan analisis, fungsi input dan output pada driver motor sudah mampu untuk mengendalikan putaran motor dc brushless pada putaran 0 sampai dengan 3.000 rpm. untuk pengujian sinyal umpan balik kecepatan motor menunjukkan lebar pulsa low pada sinyal umpan balik kecepatan tetap dengan lebar pulsa 30 ms. sedangkan lebar pulsa high pada sinyal umpan balik kecepatan motor berubah mengikuti perubahan kecepatan motor. berdasarkan hasil pengujian, pada kecepatan maksimum lebar pulsa high pada sinyal umpan balik kecepatan motor menunjukkan nilai 34 ms. tegangan analog konversi pada sinyal umpan balik pada kecepatan maksimum bernilai 2,66 v. dari hasil yang diperoleh, dapat disimpulkan bahwa perangkat keras dan algoritma kendali yang dibuat sudah menunjukkan unjuk kerja yang baik. kendali supervisory mampu mendistribusikan data ke masing-masing kendali motor yang kemudian kendali motor mengeksekusi data yang diterima untuk mengendalikan kecepatan motor dengan respon time rata-rata 0,66 ms. dengan demikian dapat disimpulkan sistem kendali yang dibuat dapat bekerja dengan baik dan dapat diimplementasikan untuk mengendalikan aktuator pada sistem platform mobile robot rev11. ucapan terimakasih penulis mengucapkan terimakasih kepada kepala bidang mekatronik serta teman-teman di bidang mekatronik yang telah membantu dalam penelitian ini. selain itu penulis juga mengucapkan terima kasih kepada pusat penelitian tenaga listrik dan mekatronik lembaga ilmu pengetahuan indonesia (lipi) atas kesempatan yang diberikan melalui dana tematik sehingga penelitian robot rev-11 dapat berjalan dengan lancar. penulis juga berterima kasih kepada semua pihak yang tidak dapat disebutkan satu persatu, yang telah membantu penulisan karya tulis ilmiah ini. daftar pustaka [1] estiko rijanto. (2005) apa itu mekatronika?. [online]. available: http://www.telimek.lipi.go.id/ [dikutip: 15 september 2011] [2] balza achmad, "simulator lengan robot enam derajat kebeasan menggunakan opengl," telkomnika, volume 6, nomor 3, pp. 209-216, 2008. [3] atef saleh, "proportional integral and derivative control of brushless dc motor," european journal of scientific research, volume 35, nomor 2, pp. 198-203, 2009. [4] kazuya shirahata. speed control methods of various types of speed control motors. [online]. available: http://www.orientalmotor.com/technology/ar ticles/pdfs/usa_renga_no166_1e.pdf [dikutip: 15 september 2011] [5] oriental motor. (2011) brushless dc motor system axh series. [online]. available: http://site.motadistribution.com/brochures/o rientalmotor/spdaxh.pdf [dikutip: 15 september 2011] [6] dian anggraini. (2010) aplikasi mikrokontroler atmega16 sebagai pengontrol sistem emergency dan lampu jalan yang dilengkapi dengan sensor cahaya (ldr) pada miniatur kompleks perumahan modern. [online]. available: http://eprints.undip.ac.id/20728/1/makala h_ta_dian.pdf [dikutip: 15 september 2011] [7] mokh. sholihul hadi. (2008) mengenal mikrokontroler avr atmega16. [online]. available: http://ilmukomputer.org/wpcontent/uploads/2008/08/sholihulatmega16.pdf [dikutip: 15 september 2011.] [8] x. xiao, y. li, m. zhang, and m. li, "a novel control strategy for brushless dc motor drive with low torque ripples," in proceeding of 31st annual conference of ieee: industrial electronics society (iecon), 2005, pp. 1660-1664. [9] j. puranen, induction motor versus permanent magnet synchronous motor in motion control applications. lappeenranta: university of technology, lappeenranta, 2006. [10] s. ruangsinchaiwanich, z.q. zhu, and d. howe, "influence of magnet shape on cogging torque and back-emf waveform in permanent magnet machines,: in proceedings of the eighth international conference on electrical machines and systems (icems), 2005, pp. 284-289. [11] microchip technology, “brushless dc (bldc) motor fundamentals”, application note, an885, 2003. [online]. available: http://electrathonoftampabay.org/www/docu ments/motors/brushless%20dc%20(bldc perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 (roni permana saputra, et. al.) jmev 02 (2011) 85-94 94 )%20motor%20fundamentals.pdf [dikutip: 15 september 2011] [12] kazuo abe, "low-noise drive technology of brushless motor," renga, vol. 163, pp. 1925, 2003. [13] texas instrument. (2008) brushless dc motor controller. [online]. available: www.ti.com/lit/ds/symlink/uc2625-ep.pdf [dikutip: 15 september 2011] [14] atmel. (2008) avr194: brushless dc motor control using atmega32m1. [online]. available: http://atmel.com/dyn/resources/prod_docum ents/doc8138.pdf [dikutip: 15 september 2011] [15] atmel. (2010) 8-bit microcontroller with 16k bytes in-system programmable flash (atmega16, atmega16l). [online]. available: http://www.atmel.com/dyn/resources/prod_d ocuments/2466s.pdf [dikutip: 15 september 2011] microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 editorial board of journal of mechatronics, electrical power and vehicular technology editor-in-chief dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com executive editor dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id pudji irasari, m.sc.rer.nat. electrical power indonesian institute of sciences pudji.irasari@lipi.go.id managing editor ghalya pikra, m.t. mechanical engineering, energy conversion indonesian institute of sciences ghalyapikra@yahoo.com naili huda, m.eng.sc. industrial engineering indonesian institute of sciences naili.huda@gmail.com noviadi arief rachman, m.t. electrical power engineering indonesian institute of sciences novi001@lipi.go.id tinton dwi atmaja, m.t. electrical engineering, informatics indonesian institute of sciences tinton_dwi@yahoo.com peer reviewer prof.dr. satryo soemantri brodjonegoro mechanical engineering bandung institute of technology bandung satrio1@indo.net.id prof.dr. jamasri composite and mechanics of materials gajah mada university yogyakarta jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering bandung institute of technology bandung suhono@stei.itb.ac.id dr. endra joelianto engineering physics, control engineering bandung institute of technology bandung ejoel@tf.itb.ac.id dr. yuliadi erdani informatics engineering polteknik manufaktur bandung yul_erdani@polman-bandung.ac.id dr. arko djajadi mechatronics engineering swiss german university serpong arko@sgu.ac.id dr. eng. tri agung rochmat mechanical engineering gajah mada university yogyakarta triagung_rohmat@ugm.ac.id journal of mechatronics, electrical power and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 tata cara penulisan redaksi menerima naskah karya tulis ilmiah yg berupa hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya. aturan penerbitan naskah adalah sebagai berikut: 1. naskah dikirim melalui e-mail ke permana.saputra@yahoo.com atau dapat melalui pos ke alamat sekretariat 2 buah hardcopy dan 1 buah softcopy. 2. sistematika penulisan terdiri dari: a. judul; title case, small caps, centered, bold, times new roman (tnr) 16, spasi 1. b. nama penulis; tanpa gelar, centered, bold, tnr 11, spasi 1. penulis ganda dengan instansi berbeda dibedakan dgn penomoran angka superscript (1) c. alamat instansi dan e-mail; centered, tnr 10, spasi 1. d. abstrak ditulis dalam bahasa indonesia dan bahasa inggris. judul dalam bahasa indonesia adalah abstrak, sedangkan dalam bahasa inggris adalah abstract; justified, bold, tnr 12, spasi 1. e. isi abstrak singkat, jelas, dan tidak melebihi 200 kata tanpa memuat gambar atau tabel; justified, tnr 10, spasi 1. f. kata kunci atau keyword terdiri dari 2-5 kata; justified, tnr 10, spasi 1. g. isi naskah; ditulis dalam 2 (dua) kolom, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. 3. aturan pembaban disusun dalam empat bagian: pendahuluan, isi makalah, hasil dan pembahasan, serta kesimpulan. diikuti ucapan terima kasih (bila diperlukan) dan daftar pustaka. pengaturan heading adalah sebagai berikut. a. heading pertama ditulis dengan format; title case, small caps, rata kiri, bold, tnr 14, spasi 1, dengan penomoran romawi diikuti titik (contoh: i. pendahuluan) b. heading kedua ditulis dengan format; title case, rata kiri, bold, tnr 11, spasi 1, dengan penomoran huruf besar diikuti titik (contoh: a. pengujian) c. heading ketiga ditulis dengan format; title case, rata kiri, italic, tnr 11, spasi 1, dengan penomoran angka diikuti kurung tutup (contoh: 1) pengujian lapangan) d. heading keempat tidak direkomendasikan, namun masih bisa diterima dengan format; sentence case, rata kiri, hanging indent 5 mm, italic, tnr 11, spasi 1, dengan penomoran huruf kecil diikuti kurung tutup (contoh: a) hasil pengujian lapangan) e. heading kelima tidak direkomendasikan, namun masih bisa diterima dengan format poin /bullet. 4. gambar, grafik dan tabel harus terbaca dengan jelas, diberi nomor urut dan keterangan ringkas, tnr 11, spasi 1. gambar harus disertai keterangan gambar dalam isi naskah. file gambar/grafik/tabel disertakan dalam folder terpisah dengan format (.tif/.jpg/.jpeg). 5. daftar pustaka; semua buku atau tulisan yang menjadi referensi harus diberi nomor dengan format [1], [2], [3], dst. referensi di akhir tulisan sesuai urutan kemunculannya dalam tulisan. pengambilan referensi yang bersumber dari electronic sources, harus mencantumkan, 1) protocol atau pelayanan, 2) lokasi, dimana item tersebut ditemukan, 3) item dapat didapatkan kembali. tidak diperkenankan mengambil acuan dari sumber sejenis wikipedia, blog pribadi atau situs lain yang tidak bersifat ilmiah. tata cara penulisan daftar pustaka secara lebih lengkap dapat mengikuti contoh-contoh pada ‘layout penulisan makalah’ di website jurnal atau sesuai tata cara penulisan referensi ieee. 6. persamaan matematik harus ditulis dengan jelas, diberi nomor urut, dan diberi keterangan notasi yang dipergunakan. 7. panjang naskah berkisar antara 4-10 halaman, termasuk gambar dan tabel tanpa lampiran. naskah direkomendasikan diketik menggunakan word processor baik open office text document (.odt) atau microsoft office word (.doc/.docx) dengan format margin 2 cm untuk tepi atas, kanan dan bawah serta 2,5 cm untuk tepi kiri pada kertas ukuran a4. dewan editor berhak menolak suatu naskah yang dianggap tidak memenuhi syarat, setelah mendengar pendapat para ahli. dewan editor berhak mengubah dan menyesuaikan bahasa dan istilah tanpa perubahaan isi, dengan tidak memberitahukan kepada penulis terlebih dahulu. jika perubahaan isi dianggap perlu, maka akan dikonsultasikan dengan penulis dewan editor mev j. mechatron. electr. power veh. technol 07 (2016) 1-6 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.1-6 accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. hardware simulation of automatic braking system based on fuzzy logic control noor cholis basjaruddin a,*, kuspriyanto b, suhendar a, didin saefudin a, virna apriani azis a adepartment of electrical engineering, politeknik negeri bandung jl. gegerkalong hilir, ds.ciwaruga, bandung, indonesia bschool of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung, indonesia received 04 october 2015; received in revised form 07 december 2015; accepted 14 december 2015 published online 29 july 2016 abstract in certain situations, a moving or stationary object can be a barrier for a vehicle. people and vehicles crossing could potentially get hit by a vehicle. objects around roads as sidewalks, road separator, power poles, and railroad gates are also a potential source of danger when the driver is inattentive in driving the vehicle. a device that can help the driver to brake automatically is known as automatic braking system (abs). abs is a part of the advanced driver assistance systems (adas), which is a device designed to assist the driver in driving the process. this device was developed to reduce human error that is a major cause of traffic accidents. this paper presents the design of abs based on fuzzy logic which is simulated in hardware by using a remote control car. the inputs of fuzzy logic are the speed and distance of the object in front of the vehicle, while the output of fuzzy logic is the intensity of braking. the test results on the three variations of speed: slow-speed, medium-speed, and high-speed shows that the design of abs can work according to design. keywords: automatic braking system; advanced driver assistance system; fuzzy logic. i. introduction every two hours, pedestrians were killed or every seven minutes, the pedestrian was injured due to being struck by a vehicle in the united states [1]. the insufficiency of braking time owned by the driver is the main reason the vehicle hit a pedestrian. the sudden appearance of pedestrians in front of vehicles often does not allow the driver to brake. the percentage of vehicles crashing object is around 14.2% of all types of collisions. the figure has not been merged with rear-end collisions which are caused by the sudden brake or stop of the vehicle in front. about 28% of the entire collision is a rear-end collision and about 25% of the collision is due to the insufficiency of the vehicle to brake [2]. three main factors causing road crashes are the driver, the vehicle, and the infrastructure. in indonesia, collisions caused by driver error are 93% [3]. efforts are being made to reduce the number of traffic accidents involving fixing the vehicles and improve infrastructure technologies as well as to increase the awareness and expertise of drivers. automatic braking system was developed to help drivers cope with braking delay so that the vehicle can avoid the collision. this device is also known as automatic/advanced emergency braking systems (aebs) [4]. abs is an element of the advanced driver assistance system (adas) or intelligent driver assistance system (idas). other elements of adas which are adaptive cruise control (acc) [5], overtaking assistance system (oas) [6], and lane keeping assist system (lkas) [7]. honda has used a collision mitigation braking system (cmbs) on products namely legend saloon (2006) and cr-v 4x4 (2007). nissan uses intelligent brake system while mercedes-benz has equipped the s-class products (2006) with brake assist plus (bas * corresponding author.tel: +62-22-2013789 e-mail: noorcholis@polban.ac.id http://dx.doi.org/10.14203/j.mev.2016.v7.1-6 n.c. basjaruddin et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 1-6 2 plus). ford and volvo jointly develop the collision mitigation by braking (cmbb). volvo s80 (2007) and ford s-max have been equipped with a collision warning with brake support system. abs technology development can be seen in figure 1. braking is done by two-stages that is monitoring the situation and step on the brake pedal. brake warning system (bws) assist the driver in recognizing situations needed for braking. at the time of dangerous situations, bws will give a warning to the driver for braking. warnings can be done through sound, light, or haptic [8]. in vehicular networks, the bws is developed into the cooperative bws [9]. in certain circumstances such as the existence of a pedestrian crossing the road suddenly, abs will perform automatic braking. at [10] examined the influence of abs braking time at the driver's behavior. some abs is developed by combining the role of the driver and braking assistance system in action. at the far distance with obstacle objects, the system will serve as bws. if the warning is not considered by the driver and the object are near, and then the abs will perform braking gradually from soft to hard brake. some research in the development of abs, among others, performed by [11, 12, 13]. in [11] and [12] were examined the use of cameras for abs, whereas [13] developed abs for smart vehicles. in the cooperative system, the abs on different vehicles works together through communication systems such as vehicular ad hoc network (vanet). some vanet research conducted were [14, 15]. cooperative abs (cabs) allows the braking a vehicle because some vehicles are far in front of him stopped. vehicle braking information obtained through inter-vehicle communication such as vanet. cabs enables the braking process can be done early and prevent pileup. other than that this technology can be developed into advanced adaptive cruise control (aacc). in cooperative acc situation monitoring and brake pedal action are carried out cooperatively with the aim to improve safety and comfort. information about when and how the intensity of braking is done by observing the data situation around the vehicle received by the sensor and communication system between vehicles. ii. research method braking is the most important action in the process of driving. two factors related to the safety braking are when and how the intensity of braking should be done. one of the factors that related to the driving comfort is the magnitude of deceleration when braking process. braking suddenly would lead to inconvenience the driver as well as passengers. in this study, the driving comfort has not considered due to the difficulties in the remote control car brakes. a. how abs work illustration of the workings of the abs can be seen in figure 2. abs will prevent the following vehicle (fv) from a collision with leading vehicle (lv) if lv braking or sudden stop. collision avoidance process is done by the brakes at braking distance (bd) so that fv car stopped just behind the lv without crashing (stopping distance, sd). before the abs gave orders automatic braking, the driver of fv will know that lv decelerates abruptly at a distance of warning distance (wd). if the warning is not taken by the driver with braking, the vehicle is automatically braked at a distance of bd. braking at such distances would cause the vehicle to stop at a distance that is still safe (od). parameters of the system can be seen in table 1. figure 2. how abs work figure 1. transition between different levels of abs n.c. basjaruddin et al./j. mechatron. elect. power, and veh. technol. 07 (2016) 1-6 3 safe braking must meet the conditions bd > sd. the stopping distance (sd) value depends on the vehicle speed and the braking intensity. at highspeed and close distance there is needed of hard braking. in contrast, the low-speed and far distance only needed a soft braking. the main issue on abs is how to regulate the intensity of the brake (br) so the car will not hit any object in various speed (v) and (bd). this issue can be resolved by using the on-off method as has been done by [16]. the use of onoff method has drawbacks when applied to the real car is braking intensity are less smooth, thereby reducing driving comfort. this paper contains improvement using the on-off method on abs by using the fuzzy logic method. the use of fuzzy logic is expected to improve the comfort of the real car. some research has been done in the development of fuzzy logic based abs among others on [17, 18, 19]. b. abs based on fuzzy logic input membership functions at the abs can be seen in figure 3 and figure 4. the membership function of the input consists of the speed and distance of the object in front of the vehicle. both the membership function is divided into three fuzzy sets are low-speed (ls), medium-speed (ms), and high-speed (hs) for speed and close-distance (cd), medium-distance (md), and far-distance (fd) for the distance. figure 5 shows the output membership function while figure 6 shows a relationship between input and output on the basis of rules that are shown in table 2. membership function output is the braking intensity which is divided into five fuzzy set that is very-soft-brake (vsb), soft-brake (sb), normal-brake (nb), hard-brake (hb), and very-hard-brake (vhb). table 1. system parameters parameter description bd braking distance sd stopping distance wd warning distance od obstacle distance v the speed of the car br brake intensity of car figure 3. membership function of distance figure 4. membership function of speed figure 5. membership function of output figure 6. the relationship between input and output n.c. basjaruddin et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 1-6 4 c. hardware simulation the block diagram of the abs hardware simulation is shown in figure 7. abs hardware simulation is built using a remote control (rc) car as shown in figure 8 and figure 9 [20]. hardware simulation used two ultrasonic sensors are which mounted on the front of the car. the sensor is used to measure the distance from lv to fv. information about object distance is provided by ultrasonic sensor 1 and 2. the potentiometer is used to adjust the speed of the remote control car. two arduino uno microcontrollers are used in this experiment. one microcontroller is used to run the fuzzy logic based abs algorithm and perform various other functions such as sensor readings and processing the signal to the actuator. the other microcontroller is used for data logging during the testing process. measurement results of testing process stored on the sd card. the arduino uno r3 is a microcontroller board based on atmega328 and library functions for fuzzy logic-based control can be added on the sources code. the library functions are using min-max mamdani method with the center of the area for the defuzzification process as inference method. the important data that obtained during testing procces using hardware simulator is stored in a secure digital (sd) memory card via arduino shield. iii. results and analysis fuzzy-logic based abs algorithm is tested in three situations, namely low-speed, mediumspeed, and high-speed. the distance from an obstacle is assumed to be fixed at 250 cm and there were observation to the the intensity of the braking so that vehicles do not hit the object, see figure 10. a. testing at different speeds at each test, the data of speed and distance stored in the sd card. testing also generates the data of stopping distance, braking distance, and obstacle distance for three different speeds. the relationship between the value of the pwm and the speed of the rc car can be seen in table 3. 1) low-speed testing the results of testing at low-speeds can be seen in figure 11. the abs starts working when the distance of the rc car and the obstacle is smaller than 120 cm. braking is done in accordance with the fuzzy logic control of verysoft-brake, soft-brake, and normal-brake. car stops when the distance of 32 cm. table 2. rules base speed ls ms hs distance cd nb hb vhb md sb nb hb fd vsb sb nb figure 7. block diagram of abs hardware simulation figure 8. side view of experiment car figure 9. front view of experiment car table 3. pwm value and speed relation pwm speed (m/s) speed level 140 0.62 low-speed 199 0.84 medium-speed 255 1.42 high-speed figure 10. test scenario n.c. basjaruddin et al./j. mechatron. elect. power, and veh. technol. 07 (2016) 1-6 5 2) medium-speed testing testing with medium-speed braking is done in accordance with the fuzzy logic control of softbrake, normal-brake, and hard-brake. the car stops when the distance of the rc car and obstacle is 14 cm. the test results in this situation can be seen in figure 12. 3) high-speed testing the results of testing at high speeds can be seen in figure 13. the braking is done in accordance with the fuzzy logic control of normal-brake, hard-brake, and very-hard-brake. the speed of the rc car to zero when the distance of rc car and the obstacle is 5 cm. b. system analysis the test results for three levels speed can be seen in table 4. based on the data obtained on table 2 it can be seen that when the remote control car speed is greater, then the stopping distance is also greater, and the distance to the obstacle becomes smaller. the braking action begins when the distance is equal or smaller than 120 cm in accordance with membership function of distance. the action of braking is done in accordance with the capabilities of the sensor in reading the distance. at low-speed, braking action is done more often than at high-speed. at high-speed, the sensor is often too late in the process of reading distance. iv. conclusion the results show that the hardware simulated of abs can work well. the fuzzy-logic based abs algorithm can set when and how the intensity of braking is needed so that the car does not crash into an obstacle. at high-speed (1.42 m/s), the sensors are too late to measure the distances thereby affecting to abs work. acknowledgement the authors would like to thank unit penelitian dan pengabdian masyarakat (uppm) politeknik negeri bandung and mechatronic laboratory at electrical departement, politeknik negeri bandung for supporting in this research. authors wish to thank the dikti dp2m for financial support through penelitian hibah bersaing 2014 and 2015. references [1] nhtsa, "traffic safet facts," national center for statistics and analysis, nhtsa, washington, dc, 2014. figure 11. test results on low-speed figure 12. test results on medium-speed figure 13. test results on high-speed table 4. braking response speed level stopping distance (cm) braking distance (cm) obstacle distance (cm) low-speed 88 120 32 medium-speed 92 106 14 high-speed 111 116 5 n.c. basjaruddin et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 1-6 6 [2] henrik clasen, "rear-end accident statistics stationary vehicles vs. stopped and moving," clepa, sweden, 2009. [3] sutanto soehodo, "road accidents in indonesia," iatss research, vol. 33, no. 2, 2009. [4] c grover et al., "automated emergency brake systems: technical requirements, costs and benefits," trl, 2008. [5] noor cholis basjaruddin et al., "developing adaptive cruise control based on fuzzy logic using hardware simulation," international journal of electrical and computer engineering (ijece), vol. 4, no. 6, 2014. [6] noor cholis basjaruddin et al., "overtaking assistant system based on fuzzy logic," telkomnika (telecommunication computing electronics and control), vol. 13, no. 1, 2015. [7] noor cholis basjaruddin et al., "lane keeping assist system based on fuzzy logic," in 2015 international electronics symposium (ies), pens, surabaya, 2015. [8] john l. campbell et al., "crash warning system interfaces:human factors insights and lessons learned," washington, dc, 2007. [9] ming-fong tsai et al., "cooperative emergency braking warning system in vehicular networks," journal on wireless communications and networking, vol. 2015, 2015. [10] takahiro wada et al., "effect of activation timing of automatic braking system on driver behaviors," in sice annual conference, taipei, 2010. [11] vicente milanés et al., "vision-based active safety system for automatic stopping," expert systems with applications, vol. 39, 2012. [12] christoph g. keller et al., "active pedestrian safety by automatic braking and evasive steering," ieee transaction on intelligent transportation systems, vol. 12, no. 4, december 2011. [13] shrey modi et al., "a driver-automation system for brake assistance in intelligent vehicles," in 10th ieee international conference on industrial informatics (indin), beijing, 2012, pp. 446 451. [14] g. chandrasekaran, "vanets: the networking platform for future vechicular applications," in mobile networking for vehicular environments, los angeles, 2009, pp. 109-114. [15] sherali zeadally et al., "vehicular ad hoc networks (vanets): status, results, and challenges," telecommun syst, 2010. [16] wahyu eko phasa, "automatic braking system on remote control car," bandung, 2013. [17] ml sharma and sheetal atri, "fuzzy rule based automatic braking system in train using vhdl," international journal of computer science and technology, vol. 2, no. 2, pp. 332-335, 2011. [18] j.h li and h.m kim, "design for the predictor of the emergency braking system based on fuzzy algorithm," journal of automation and control engineering vol.1 no.3, vol. 1, no. 3, pp. 240-244, 2013. [19] dhivya p and murugesan a, "intelligent car braking system with collision avoidance and abs," international journal of computer applications, 2015. [20] virna apriani azis, "automatic braking system based on fuzzy logic," electrical engineering, politeknik negeri bandung, bandung, final project 2014. i. introduction ii. research method a. how abs work abs based on fuzzy logic c. hardware simulation iii. results and analysis testing at different speeds low-speed testing 2) medium-speed testing 3) high-speed testing b. system analysis conclusion acknowledgement references microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, no 2, 2010 issn 2087-3379 editorial board of journal of mechatronics, electrical power and vehicular technology editor-in-chief dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com executive editor dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id pudji irasari, m.sc.rer.nat. electrical power indonesian institute of sciences pudji.irasari@lipi.go.id managing editor ghalya pikra, m.t. mechanical engineering indonesian institute of sciences ghalyapikra@yahoo.com naili huda, m.eng.sc. industrial engineering indonesian institute of sciences naili.huda@lipi.go.id noviadi arief rachman, m.t. electrical power engineering indonesian institute of sciences novi001@lipi.go.id tinton dwi atmaja, m.t. informatics, electrical engineering indonesian institute of sciences tinton_dwi@yahoo.com peer reviewer prof.dr. satryo soemantri brodjonegoro mechanical engineering bandung institute of technology bandung satrio1@indo.net.id prof.dr. jamasri composite and mechanics of materials gajah mada university yogyakarta jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering bandung institute of technology bandung suhono@stei.itb.ac.id dr. endra joelianto engineering physics, control engineering bandung institute of technology bandung ejoel@tf.itb.ac.id dr. yuliadi erdani informatics engineering polteknik manufaktur bandung yul_erdani@polman-bandung.ac.id dr. arko djajadi mechatronics engineering swiss german university serpong arko@sgu.ac.id dr. eng. tri agung rochmat mechanical engineering gajah mada university yogyakarta triagung_rohmat@ugm.ac.id journal of mechatronics, electrical power and vehicular technology vol. 01, no 2, 2010 issn 2087-3379 tata cara penulisan redaksi menerima naskah karya tulis ilmiah yg berupa hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya. aturan penerbitan naskah adalah sebagai berikut: 1. naskah dikirim melalui e-mail ke permana.saputra@yahoo.com atau dapat melalui pos ke alamat sekretariat 2 buah hardcopy dan 1 buah softcopy. 2. sistematika penulisan terdiri dari: a. judul; title case, small caps, centered, bold, times new roman (tnr) 16, spasi 1. b. nama penulis; tanpa gelar, centered, bold, tnr 12, spasi 1. penulis ganda dengan instansi berbeda dibedakan dgn penomoran angka superscript ( 1 ) c. alamat instansi dan e-mail; centered, tnr 10, spasi 1. d. abstrak ditulis dalam bahasa indonesia dan bahasa inggris. judul dalam bahasa indonesia adalah abstrak, sedangkan dalam bahasa inggris adalah abstract; justified, bold, tnr 12, spasi 1. e. isi abstrak singkat, jelas, dan tidak melebihi 200 kata tanpa memuat gambar atau tabel; justified, tnr 10, spasi 1. f. kata kunci atau keyword terdiri dari 2-5 kata; justified, tnr 10, spasi 1. g. isi naskah; ditulis dalam 2 (dua) kolom, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. 3. aturan pembaban disusun dalam empat bagian: pendahuluan, isi makalah, hasil dan pembahasan, serta kesimpulan. diikuti ucapan terima kasih (bila diperlukan) dan daftar pustaka. pengaturan heading adalah sebagai berikut. a. heading pertama ditulis dengan format; title case, small caps, rata kiri, bold, tnr 14, spasi 1, dengan penomoran romawi diikuti titik (contoh: i. pendahuluan) b. heading kedua ditulis dengan format; title case, rata kiri, bold, tnr 11, spasi 1, dengan penomoran huruf besar diikuti titik (contoh: a. pengujian) c. heading ketiga ditulis dengan format; title case, rata kiri, italic, tnr 11, spasi 1, dengan penomoran angka diikuti kurung tutup (contoh: 1) pengujian lapangan) d. heading keempat tidak direkomendasikan, namun masih bisa diterima dengan format; sentence case, rata kiri, hanging indent 5 mm, italic, tnr 11, spasi 1, dengan penomoran huruf kecil diikuti kurung tutup (contoh: a) hasil pengujian lapangan) e. heading kelima tidak direkomendasikan, namun masih bisa diterima dengan format poin /bullet. 4. gambar, grafik dan tabel harus terbaca dengan jelas, diberi nomor urut dan keterangan ringkas, tnr 11, spasi 1. gambar harus disertai keterangan gambar dalam isi naskah. file gambar/grafik/tabel disertakan dalam folder terpisah dengan format (.tif/.jpg/.jpeg). 5. daftar pustaka; semua buku atau tulisan yang menjadi referensi harus diberi nomor dengan format [1], [2], [3], dst. referensi di akhir tulisan sesuai urutan kemunculannya dalam tulisan. pengambilan referensi yang bersumber dari electronic sources, harus mencantumkan, 1) protocol atau pelayanan, 2) lokasi, dimana item tersebut ditemukan, 3) item dapat didapatkan kembali. tidak diperkenankan mengambil acuan dari sumber sejenis wikipedia, blog pribadi atau situs lain yang tidak bersifat ilmiah. tata cara penulisan daftar pustaka secara lebih lengkap dapat mengikuti contoh-contoh pada ‘layout penulisan makalah’ di website jurnal atau sesuai tata cara penulisan referensi ieee. 6. persamaan matematik harus ditulis dengan jelas, diberi nomor urut, dan diberi keterangan notasi yang dipergunakan. 7. panjang naskah berkisar antara 4-10 halaman, termasuk gambar dan tabel tanpa lampiran. naskah direkomendasikan diketik menggunakan word processor baik open office text document (.odt) atau microsoft office word (.doc/.docx) dengan format margin 2 cm untuk tepi atas, kanan dan bawah serta 2,5 cm untuk tepi kiri pada kertas ukuran a4. dewan editor berhak menolak suatu naskah yang dianggap tidak memenuhi syarat, setelah mendengar pendapat para ahli. dewan editor berhak mengubah dan menyesuaikan bahasa dan istilah tanpa perubahaan isi, dengan tidak memberitahukan kepada penulis terlebih dahulu. jika perubahaan isi dianggap perlu, maka akan dikonsultasikan dengan penulis dewan editor mev j. mechatron. electr. power veh. technol. 06 (2015) 113-122 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.113-122 comparative study between internal ohmic resistance and capacity for battery state of health estimation m. nisvo ramadan, bhisma adji pramana, sigit agung widayat, lora khaula amifia, adha cahyadi *, oyas wahyunggoro department of electrical engineering and information technology, universitas gadjah mada jalan grafika no 2 universitas gadjah mada yogyakarta 55581 indonesia received 26 october 2015; received in revised form 27 november 2015; accepted 01 december 2015 published online 30 december 2015 abstract in order to avoid battery failure, a battery management system (bms) is necessary. battery state of charge (soc) and state of health (soh) are part of information provided by a bms. this research analyzes methods to estimate soh based lithium polymer battery on change of its internal resistance and its capacity. recursive least square (rls) algorithm was used to estimate internal ohmic resistance while coloumb counting was used to predict the change in the battery capacity. for the estimation algorithm, the battery terminal voltage and current are set as the input variables. some tests including static capacity test, pulse test, pulse variation test and before chargedischarge test have been conducted to obtain the required data. after comparing the two methods, the obtained results show that soh estimation based on coloumb counting provides better accuracy than soh estimation based on internal ohmic resistance. however, the soh estimation based on internal ohmic resistance is faster and more reliable for real application. keywords: battery management system; state of health; lithium polymer; recursive least square; coulomb counting. i. introduction global warming is one among hot issues a lot of people talk about. in 2013, the average of earth temperature has reached 14.6°c, it was up to 0.6°c compared to the mid-20th century [1]. one of the main causes of global warming is the excessive use of fossil fuel. as it is known number of cars, which are using fossil fuels, continues to grow significantly. this case makes the demand of fossil fuels increases and is known as one major cause of global warming. electric car is one way to reduce fossil fuel consumption in order to hold global warming. the use of electric car is estimated to increase rapidly by 2020 [2]. for this car, lithium battery is widely used as the main energy source. thus battery is key to the success or failure of electric cars. to avoid battery failure, battery management system (bms) is usually required. bms is a system aimed for regulating the battery work in its prime area of operation and providing information to the user to perform the necessary actions such as stopping the use of battery or charging the battery. in this case, bms optimizes the operation of the electric vehicle by knowing the capacity of the battery that has been used as well as ensuring extended battery life. it also controls the cell charging, protects the battery, sets the battery condition, and maintains the balance voltage among battery cells. it is known that state of charge (soc) and state of health (soh) are part of the information provided by bms. as soc and soh can not be measured directly, an algorithm based on battery model is needed to estimate them. there are various battery models that have been developed. in general, battery model is divided into four classes: physical model (electrochemical), statistical model, analytical model, and electrical equivalent circuit model [3]. electrical equivalent circuit model is widely used. this model allows battery parameters analysis using mathematical calculations of circuit components [3-5]. battery in most cases is characterized using parameters of lumped circuit model. with various approaches, *corresponding author. telp : +62-89673487276 e-mail : adha.imam@ugm.ac.id http://dx.doi.org/10.14203/j.mev.2015.v6.113-122 mailto:adha.imam@ugm.ac.id m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 114 battery parameters can be found using many algorithms, such as i-arx [3], and recursive least square [4]. soh describes the general condition and performance of the battery compared to that of battery when it is still new. moreover soh estimation allows us to estimate the life of battery to avoid battery failure due to improper usage. on electric cars, soh informs the user that the battery replacement is needed when it reaches a certain degradation threshold. the study about soh increases recently. a common approach is considering soh estimation as a black box that is solved using artificial intelligence (ai) and machine learning (ml) with various battery condition without considering battery aging mechanism. the studies of ai and ml algorithms include neural network (nn) [5], [6], fuzzy logic [7], and support vector machine (svm) [8]. in this study, valid and sufficient data are required to provide accurate estimation. others methods, which are based on numerical analysis, describe battery aging mechanism such as mathematic equation [9], equivalent circuit model [10–12], and electro-chemical model [13]. in this paper, a battery soh estimation method is proposed based on internal ohmic resistance and capacity of the battery where performances are compared. as the battery is used, its internal ohmic resistance will change so that it can be used for soh estimation. the capacity will degrade due to battery aging that informs the degradation of soh. the battery capacity can be obtained using coulomb counting method that computes current which flows of the battery. ii. battery model a. equivalent circuit model the first-order resistor-capacitor (rc) model is one among the best options available to be used in this work. the reason is the trade off between complexity, accuracy, and robustness as stated by x hu [14]. the capacitance ccap in figure 1 represents the soc of the battery. using coulomb counting, the soc can be defined as follows: 𝑆𝑂𝐶 = 𝑆𝑂𝐶𝑜 − 1 𝐶𝑁 ∫ 𝐼 𝑑𝑡 𝑡 𝑡𝑜 (1) where soc0 is soc at initial time to, cn is capacity value in standard condition of the battery, η is coulombic efficiency that equals 1 while discharge and is smaller than 1 in charge and i represents current which is negative at charge and positive at discharge [15]. in figure 1, voc is cell open circuit voltage (ocv) of battery cell, r0 is internal ohmic resistance, rp is diffusion resistance, cp is diffusion capacitance, ibatt, vt are the corresponding current and terminal voltage. here vt is set as output variable. current source, ibatt, represents the current flowing out of the battery cell. ibatt acts as input variable. r0 describes internal resistance. the mathematical equations for the equivalent circuit are as follows: 𝑢�̇� = − 𝑢𝑝 𝐶𝑝𝑅𝑝 + 𝐼𝑏𝑎𝑡𝑡 𝐶𝑝 , (2) �̇�𝑜𝑐 = 𝐼𝑏𝑎𝑡𝑡 𝐶𝑐𝑎𝑝 , (3) 𝑉𝑡 = 𝑉𝑜𝑐 − 𝑢𝑝 − 𝐼𝑏𝑎𝑡𝑡 𝑅0 (4) where 𝑢𝑝 is the voltage at the parallel rc network. b. battery testing and schedule system when a car is moving irregularly, at a certain moment the batteries undergo a large load, but in other time encounter low constant load according to the usage. changing road conditions can make the battery load varies unpredictably. thus, this study included a few additional tests to see the battery life as well as to ensure that the battery model is valid. schematic design of the experiments is shown in figure 2. figure 1. battery model structure [10] figure 2. experimental schematic design m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 115 the objective of this experimental design is to obtain the battery parameter in the form of current and voltage. in this work, the experimental devices consist of dc power source using imax b6 lipro balance charger, dummy load using gw instek pel-2004, microcontroller arduino uno 32, and matlab® r2013a software for computation and analysis purposes. moreover, turnigy lithium polymer battery with a nominal capacity of 2.2 ah was used in this study. the battery specifications are shown in table 1 [16]. the experimental procedures are begun with static capacity test at 1c discharge current as shown in figure 3. this test is conducted to determine the battery capacity and to obtain the corresponding battery soc. the next test is pulse test. in this test, the battery is discharged for 30 seconds and then rested for 30 seconds. after that, connect to load again and repeat the proses until the cut off voltage is reached. cut off voltage is defined as terminal voltage at 20% soc. discharge pulse is 30 seconds for better accuracy of ocv curve because more data points ocv. rest 30 seconds because at that time the battery terminal voltage has reached steady state. enlarged rest time will have no effect on the condition of the battery terminal voltage. soc 20% is used as discharge limits to avoid over discharge and try to treat the battery as safely as possible. pulse test is conducted to identify the battery model parameters of equivalent circuit and to obtain the ocv-soc relationship. the next test is a test with varying input. the test is used for parameters of equivalent circuit model validation. the last test is aging cycle test where each cycle is done with constant current charging or discharging mode until the voltage reaches a specified value. battery cycle life is usually determined by the number of cycles of charge – discharge. a battery can work well before its nominal capacity falls below 80% of the initial capacity of the battery [3][9][17]. therefore, a number of cycles are needed to see the effect that occurs in the battery. iii. battery model parameter identification a. identification method based on the battery model shown in figure 1, there are four series of parameters that must be obtained, those are ccap, ro, rp, and cp. the identification details of these parameters are illustrated as follows: a) the value of ccap is obtained from static capacity test as shown in figure 4. 𝐶𝑐𝑎𝑝 = 𝑖 ∆𝑡 ∆𝑉 . (5) b) in the pulse test, voc is obtained from steady state voltage of each pulse as shown figure 5. c) the resistance ro is proportional to the reduction of voltage drop connected to the load. resistance rp and capacitance cp are start static capacity test pulse test pulse variation test cc – charge & cc – discharge end figure 3. battery test schedule table 1. battery specifications parameter value capacity 2.2 ah max discharge current 44 a max charge rate current 4.4 a charge limit voltage 4.2 v discharge limit voltage 2.7 v m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 116 associated with voltage changes as shown in figure 5. rls algorithm is used to obtain the value of ro, rp, and cp. linear relationship of input and output is obtained through a transfer function model of the battery. 𝑉 = 𝑉𝑡 − 𝑉𝑜𝑐 (6) 𝑉𝑡 − 𝑉𝑜𝑐 = [ 𝑅𝑝 1+𝑠𝑅𝑝𝐶𝑝 + 𝑅0] 𝐼 (7) 𝑠 = 2 𝑇 𝑘−1 𝑘+1 (8) where t is the sampling period. then equation (7) can be written as: 𝑉(𝑘) + 𝑎1𝑉(𝑘 − 1) = 𝑏0𝐼(𝑘) + 𝑏1(𝑘 − 1) (9) where 𝑎1 = 𝑇−2𝑅𝑝𝐶𝑝 𝑇+2𝑅𝑝𝐶𝑝 (10) 𝑏0 = (𝑅𝑝+𝑅0)𝑇+2𝑅0𝑅𝑝𝐶𝑝 𝑇+2𝑅𝑝𝐶𝑝 (11) 𝑏1 = (𝑅𝑝+𝑅0)𝑇−2𝑅0𝑅𝑝𝐶𝑝 𝑇+2𝑅𝑝𝐶𝑝 (12) a1, b0, b1 are parameters that need to be solved. in this work, these parameters will be defined using rls algorithm. the process in obtaining the parameters using rls algorithm is described as follows: 𝐺(𝑘) = 𝑃(𝑘−1)𝜑(𝑘) 1+𝜑𝑇(𝑘)𝑃(𝑘−1)𝜑(𝑘) (13) 𝜃(𝑘) = 𝜃(𝑘 − 1) + 𝐺(𝑘) [ 𝑉(𝑘) − 𝑉(𝑘 − 1) − 𝜑𝑇 (𝑘)𝜃(𝑘 − 1) ] (14) 𝑃(𝑘) = 𝑃(𝑘 − 1) − 𝐺(𝑘)𝜑𝑇 (𝑘)𝑃(𝑘 − 1) (15) where 𝜑(𝑘) = [ 𝑉(𝑘 − 1), 𝐼(𝑘), 𝐼(𝑘 − 1) ]𝑇 , (16) 𝜃(𝑘) = [ −𝑎1, 𝑏0, 𝑏1 ] 𝑇 . (17) the initial estimation value of parameter θ(0) and covariance matrix p(0) are first determined. ro, rp, and cp parameter can be obtained by rewriting equation (10), (11), and (12) as: 𝑅𝑝 = 2(𝑎1𝑏0+𝑏1) 1−𝑎1 2 , (18) 𝐶𝑝 = 𝑇(1+𝑎1) 2 4(𝑎1𝑏0+𝑏1) , (19) 𝑅0 = 𝑏0−𝑏1 1+𝑎1 . (20) b. battery parameter estimation result figure 6 represents the relationship between soc and ocv. from this relationship, the soc can be predicted if value of voc is known. figure 7, 8, and 9 respectively are r0-soc, rp–soc, and cp-soc curves which are approximated by a second order polynomial. matlab® / simulink™ was used to simulate the behavior of the battery. by trial and error, the parameters value are selected at 90% soc. this choice will give good estimation errors. it seems that the model is able to follow the changes in the terminal voltage vt as shown in the pulse variations test 1 and 2 in figure 10(a) and 11(a). in addition, the model is able to predict the battery vt when the current variation is added. it is also indicated by the relative error. in the pulse variation test 1, the maximum relative error is less than 3%, while in the pulse variation test 2, the maximum relative error is less than 1.5% as shown in figure 10(b) and 11(b). this research was conducted at room temperature and the battery was not maintained at a certain temperature. however, the battery model can work optimally with the mean relative error for pulse variation of 0.25% for test 1 and the mean relative error pulse variation of 0.19% for test 2. figure 4. static capacity test figure 5. zoom-in of discharge pulse test m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 117 based on this error value, this model is acceptable. as shown in figure 4, the battery discharge curve indicates that the battery is a nonlinear system as the voltage drops drastically when it is nearly depleted. when the battery capacity is approaching its lowest discharged limit, the battery voltage drops quickly and the condition is difficult to be modeled. hence, the model well describes the battery on the linear part where the soc is between 80% and 20%. iv. state of health (soh) as the lithium batteries start degrading once manufactured, due to the chemical degradation of the active material and other electrochemical phenomena, the internal ohmic resistance will increase and the capacity will decrease with age [18]. the process of degradation will change the battery performance. by increasing the number of cycles, the battery performance will decrease. this condition is monitored by soh. soh can be described as the battery performance at the present time compared to the performance at ideal condition and the battery’s fresh state [19]. there are many ways to determine the value of soh, which are based on internal ohmic resistance, the battery capacity, the slope of charge or discharge curve, and the curve area of charge or discharge. however, the determination of the soh based on internal resistance is more frequently used. a. soh based on internal ohmic resistance one of the battery parameters that changes as a result of the degradation process is an internal ohmic resistance. by increasing number of cycles, the battery internal resistance will also increase. therefore, the internal resistance can be selected to determine the value of soh. 0% soh means that the battery reaches its end of life. a battery reaches its end of life, when the internal resistance rises twice its initial value [17]. in other words: soh= 100% <=> r=riv soh= 0% <=> r=reol=2xriv with riv is the initial value of internal resistance, and reol is the value of internal resistance at the end of life. therefore, soh can be formulated into: 𝑆𝑂𝐻 = (2 − 𝑅 𝑅𝐼𝑉 ) 𝑥100%. (21) figure 6. soc-ocv plot figure 8. rp-soc plot figure 7. ro-soc plot figure 9. cp-soc plot m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 118 other forms of soh based on internal resistance is formulated as: 𝑆𝑂𝐻 = (1 + 𝑅𝐼𝑉−𝑅 𝑅𝐼𝑉 ) 𝑥100% (22) where, r is the actual internal resistance and riv is internal resistance of new battery [20]. the flowchart of soh estimation on the basis of internal resistance is shown in figure 12. data from the experiment is shown in figure 13. it is seen that the resistance of the battery increases with the increasing number of cycles. soh curve in figure 14(a) was soh based on internal resistance which was obtained from experiments. figure 14(b) shows soh curve from the battery model, the internal resistance value was obtained from the estimation using rls algorithms. (a) (b) figure 10. validation result in pulse variation test 1; (a) terminal voltage in pulse; (b) terminal voltage error in pulse (a) (b) figure 11. validation result in pulse variation test 2; (a) terminal voltage in pulse; (b) terminal voltage error in pulse m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 119 the result of soh from the model has similar trend of that from the experimental. when the cycle is more than 20, the estimated soh also shows 0% which is the same as the experimental results. in addition, the shape of soh estimation curve is similar to the soh experimental curve. however, this estimation algorithm does not give good estimation accuracy. as shown on the relative error of soh in figure 15, it can be seen that the greater error occurs when the cycle is more than 20. the soh estimation based internal ohmic resistance can be determined easily. by obtaining the internal resistance only, the soh can be estimated immediately. therefore, this method is suitable to be applied on electric vehicle. b. soh based on battery capacity in addition to using the internal ohmic resistance, soh of battery can also be determined using its capacity. the battery start pulse test all data ? recursive least square algorithm ro soh=2-(r/riv) end no yes ro=rivpulse 1 yes no figure 12. flowchart of soh estimation based on internal ohmic resistance figure 13. change of internal ohmic resistance m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 120 capacity will decrease with increasing number of charge-discharge cycles. the battery reaches its end of life which means 0% soh when the capacity falls to 80% of its initial value [17] soh= 100% <=> c=civ soh= 0% <=> c=ceol=0.8xciv with civ is the initial value of the capacity, and ceol is the value of the capacity at the end of life. soh equation based on the capacity [17] is: 𝑆𝑂𝐻 = ( 𝐶 𝐶𝐼𝑉 −0.8 0.2 ) 𝑥100% (23) and 𝐶 = ∆𝑆𝑂𝐶 ∗ 𝑄 (24) with c is the value of computed capacity, ∆𝑆𝑂𝐶 is the difference between initial soc and soc at the current time, and q is the new battery capacity. c was computed with two methods, coulomb counting method and open circuit voltage method respectively. the flowchart of soh estimation based on the battery capacity is shown in figure 16. the result of the c value is shown in figure 17. as shown in figure 17, the capacity of a new battery is no more than 2.2 ah but more than 1.78 ah. that happens because the used value is battery capacity at 80% soc. figure 17 also shows the soh change for both methods. both methods show similar trends of soh. the soh which is based on coulomb counting method is smaller than the soh which is based on open circuit voltage method so that it reaches the end of life threshold first. both methods are easy to use in estimating soh, but usually need longer computing time until all data is computed (a) (b) figure 14. (a) soh from experiment; (b) soh from model figure 15. relative error of soh m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 121 v. conclusion based on the simulation and experimental results, it can be concluded that the model can be used to estimate the soh as proven. the soh estimation method based on battery capacity is more accurate than that based on internal ohmic resistance. however, the soh estimation method based on internal ohmic resistance is faster. the methods also confirm that the soh of the battery decreases according to the increasing number of charge-discharge cycles. start finish initial soc compute c soh = ( c/civ 0.8 ) / 0.2 * 100% compute soc civ = c all data ? cycle 1 ? all cycle ? yes no no no yes yes figure 16. flowchart of soh estimation based on capacity (a) (b) figure 17. change of battery capacity; (a) capacity cycle; (b) soh cycle m.n. ramadan et al. / j. mechatron. electr. power veh. technol. 06 (2015) 113-122 122 acknowledgement this research program is fully supported by universitas gadjah mada faculty of engineering. therefore, the authors would like to express their sincere appreciation to the faculty for providing the grant. references [1] s. cole and m. leslie, “long-term global warming trend sustained in 2013,” 2014. [online]. available: http://climate.nasa.gov/news/1029/. [2] a. dinger et al., “focus batteries for electric cars,” 2010. [3] t. sar et al., “a hybrid battery model and state of health estimation method for lithium-ion batteries,” pp. 1349–1356, 2014. [4] s. li et al., “study of battery modeling using mathematical and circuit oriented approaches,” pp. 1–8, 2011. [5] h. lin et al., “estimation of battery state of health using probabilistic neural network,” vol. 9, no. 2, pp. 679–685, 2013. [6] d. andre et al., “comparative study of a structured neural network and an extended kalman filter for state of health determination of lithium-ion batteries in hybrid electric vehicles,” eng. appl. artif. intell., vol. 26, no. 3, pp. 951–961, 2013. [7] p. singh and d. reisner, “fuzzy logic-based state-of-health determination of lead acid batteries,” 24th annu. int. telecommun. energy conf., pp. 583–590. [8] v. klass and m. behm, “a support vector machine-based state-of-health estimation method for lithium-ion batteries under electric vehicle operation,” vol. 270, pp. 262–272, 2014. [9] z. guo et al., “state of health estimation for lithium ion batteries based on charging curves,” j. power sources, vol. 249, pp. 457–462, 2014. [10] y. zou et al., “combined state of charge and state of health estimation over lithiumion battery cell cycle lifespan for electric vehicles,” j. power sources, vol. 273, pp. 793–803, 2015. [11] c. r. gould et al., “new battery model and state-of-health determination through subspace parameter estimation and stateobserver techniques,” vol. 58, no. 8, pp. 3905–3916, 2009. [12] a. hentunen et al., “electrical battery model for dynamic simulations of hybrid electric vehicles,” 2011 ieee veh. power propuls. conf., pp. 1–6, sep. 2011. [13] x. li and s. choe, “state-of-charge (soc) estimation based on a reduced order electrochemical thermal model and extended kalman filter,” 2013 am. control conf., pp. 1100–1105, jun. 2013. [14] x. hu et al., “a comparative study of equivalent circuit models for li-ion batteries,” j. power sources, vol. 198, pp. 359–367, 2012. [15] l. lu et al., “a review on the key issues for lithium-ion battery management in electric vehicles,” j. power sources, vol. 226, pp. 272–288, mar. 2013. [16] a. hand, “no title.” [online]. available: http://www.hobbyking.com/hobbyking/store /__317__85__batteries_accessoriesturnigy_lipoly.html. [accessed: 20-nov2015]. [17] a. zenati et al., “a methodology to assess the state of health of lithium-ion batteries based on the battery ’ s parameters and a fuzzy logic system,” iecon 2010, 2010. [18] e. davis et al., “internal ohmic measurements and their relationship to battery capacity – epri’s ongoing technology evaluation,” pp. 1–10. [19] m. u. cuma and t. koroglu, “a comprehensive review on estimation strategies used in hybrid and battery electric vehicles,” renew. sustain. energy rev., vol. 42, pp. 517–531, 2015. [20] j. remmlinger et al., “on-board state-ofhealth monitoring of lithium-ion batteries using linear parameter-varying models q,” j. power sources, vol. 239, pp. 689–695, 2013. microsoft word vol03_no1_v4 mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved direction and policies needed to support hybrid electric car research arah dan kebijakan yang diperlukan dalam menunjang penelitian mobil listrik hibrid ridwan arief subekti a,*, agus hartanto a, vita susanti a a pusat penelitian tenaga listrik dan mekatronik lipi kompleks lipi jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia received 15 march 2012; received in revised form 28 june 2012; accepted 29 june 2012 published online 31 july 2012 abstract the rising number of vehicles over the years has driven the increase of air pollution and fuel consumption. one of the solutions to overcome this problem is using hybrid electric car because it is environmentally friendly and efficient in fuel consumption. lipi has conducted electric car research since 1997, but there were so many problems in its development that electric car can not be developed into a national industry scale. therefore, it is important to conduct a study that maps the problems and finds the solutions to prevent the same failure of electric car commercialization process from happening to hybrid electric car . this study was done by collecting and analyzing the primary and secondary data through interviews, discussing electric hybrid car with stakeholders, and examining earlier study results and regulations. based on this study, several policies to support sustainability research of hybrid electric car were proposed. some recommendations were the making of national roadmap and regulation for the usage of hybrid electric car on the road. for policy makers at lipi, a research focus, research coordination, and pre-commercialization program were recommended. key words: national policy, hybrid electric cars, research, air pollution, national road map. abstrak peningkatan jumlah kendaraan bermotor dari tahun ke tahun menyebabkan peningkatan pencemaran udara dan konsumsi bbm. salah satu cara untuk mengatasi masalah tersebut adalah dengan menggunakan kendaraan mobil listrik hibrid karena ramah lingkungan dan hemat bbm. lipi telah mengembangkan penelitian mobil listrik sejak tahun 1997. akan tetapi muncul berbagai permasalahan yang menyebabkan mobil listrik tersebut tidak dapat berkembang ke skala industri nasional. oleh karena itu dilakukan suatu kajian untuk memetakan permasalahan dan mencari solusi agar kegagalan proses komersialisasi mobil listrik tidak terulang pada mobil listrik hibrid yang saat ini penelitiannya masih berjalan. kajian ini dilakukan dengan mengumpulkan dan menganalisis data primer dan sekunder melalui wawancara, diskusi dengan pihak terkait, serta mempelajari hasil kajian dan peraturan yang ada. berdasarkan kajian ini selanjutnya direkomendasikan beberapa usulan kebijakan untuk menunjang kesinambungan penelitian mobil listrik hibrid. beberapa rekomendasi yang diusulkan antara lain adalah perlunya dukungan pemerintah pusat melalui program nasional mobil listrik hibrid yang didukung dengan adanya road map nasional dan peraturan legalitas penggunaan mobil listrik hibrid di jalan raya, sedangkan untuk pengambil kebijakan di lingkungan lipi, direkomendasikan adanya fokus penelitian, koordinasi penelitian dan program pra komersialisasi. kata kunci: kebijakan nasional, mobil listrik hibrid, penelitian, polusi udara, road map nasional. i. pendahuluan jumlah kendaraan bermotor di indonesia dari tahun ke tahun meningkat secara tajam. pada tahun 2004 kendaraan bermotor yang terdiri dari mobil penumpang, bis, truk, dan sepeda motor berjumlah sekitar 30,7 juta, dan pada tahun 2009 jumlahnya mencapai 70,7 juta, sehingga dalam kurun waktu 5 tahun jumlahnya meningkat lebih dari 2 kali lipat [1]. peningkatan jumlah kendaraan bermotor tersebut mempertinggi tingkat konsumsi bahan bakar minyak (bbm) sehingga sejak tahun 2004 indonesia harus mengimpor bbm untuk memenuhi kebutuhan bbm dalam negeri (gambar 1) [2]. kenaikan konsumsi bbm mengakibatkan subsidi yang * corresponding author. tel: +62-22-2503055 e-mail: ridwanarief_rais@yahoo.com r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 2 gambar 1. grafik produksi dan konsumsi minyak mentah indonesia [2]. ditanggung oleh pemerintah juga meningkat. pada apbn 2011, anggaran subsidi untuk sektor energi mencapai rp136,6 triliun dimana sebagian besar anggaran subsidi tersebut dialokasikan untuk subsidi bbm yaitu sebesar rp95,9 triliun dan subsidi listrik sebesar rp40,7 triliun [3]. dampak lain adalah polusi udara meningkat sehingga biaya kesehatan juga meningkat. pada tahun 2002 indonesia menanggung kerugian sekitar us$400 juta per tahun dalam bentuk kehilangan produktifitas dan biaya kesehatan. apabila tidak ada upaya pencegahan polusi udara ini maka pada tahun 2015 diperkirakan pengeluaran biaya kesehatan sekitar us$450 juta [4][5]. untuk mengatasi permasalahan tersebut, salah satu cara adalah dengan pemakaian kendaraan listrik hibrid karena lebih ramah lingkungan dan hemat bbm jika dibandingkan dengan kendaraan konvensional [6]. kendaraan listrik hibrid adalah kendaraan listrik dengan tambahan generator yang berfungsi untuk mengisi baterai saat mulai melemah, sedangkan kendaraan listrik adalah kendaraan yang menggunakan motor listrik sebagai tenaga penggeraknya. puslit telimek lipi telah melakukan penelitian mengenai mobil listrik sejak tahun 1997 dan pada tahun 2005, contoh produk mobil listrik hasil penelitian tersebut diserahkan kepada presiden republik indonesia susilo bambang yudhoyono. tetapi dalam perkembangannya muncul berbagai permasalahan, sehingga mobil listrik tersebut tidak dapat berkembang ke skala industri nasional. salah satu penyebab tidak berkembangnya mobil listrik tersebut adalah masalah kehandalan. pada tahap awal penelitian mobil listrik, prototipe yang dihasilkan masih jauh dari istilah sempurna karena belum teruji kehandalannya. hal ini terjadi karena keterbatasan waktu penelitian, peralatan laboratorium tidak komplet, sumber daya manusia terbatas, dana penelitian kecil serta tidak adanya koordinasi penelitian. pengembangan penelitian mobil listrik di puslit telimek lipi berlanjut dengan adanya penelitian mobil listrik hibrid atau lebih dikenal dengan istilah mobil hibrid dimana penelitiannya dimulai sejak tahun 2005. beberapa penelitian yang berhubungan dengan mobil listrik hibrid yang telah dilakukan di puslit telimek lipi antara lain adalah rancang bangun mobil hibrid, sistem transmisi, sarana uji, metode fast charging, sistem display indikator, motor dc, dinamika unit hibrid, electronic power steering, sistem manajemen energi, dan lainnya [7]. banyaknya topik penelitian yang dikerjakan, sedangkan sdm dan dana penelitian yang terbatas menyebabkan teknologi yang dikuasai menjadi kurang mendalam atau sangat global sehingga penelitian mobil listrik hibrid menjadi tidak fokus. tidak adanya kooordinasi antar sub penelitian yang bernaung di bawah penelitian mobil listrik hibrid menyebabkan prototipe yang dihasilkan dari sub kegiatan tersebut tidak dapat diintegrasikan dengan prototipe mobil listrik hibrid seperti prototipe gear transmisi, sistem pengisian fast charging, motor dc, dan electronic power steering. berdasarkan latar belakang tersebut maka dilakukan suatu kajian guna mencari akar permasalahan dan solusi agar kegagalan proses komersialisasi mobil listrik tidak terulang pada penelitian mobil listrik hibrid yang sampai saat ini penelitiannya masih berjalan di puslit telimek lipi. kajian tersebut menghasilkan beberapa rekomendasi yang perlu dilakukan yaitu usulan kebijakan dan langkah-langkah strategis yang menunjang kesinambungan penelitian mobil listrik hibrid. beberapa rekomendasi yang diusulkan antara lain adalah perlunya dukungan r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 3 pemerintah pusat melalui program nasional mobil listrik hibrid yang didukung dengan adanya road map nasional dan peraturan legalitas penggunaan mobil listrik hibrid di jalan raya, sedangkan untuk pengambil kebijakan di lingkungan lipi, direkomendasikan beberapa hal yang antara lain adalah perlunya fokus penelitian, koordinasi penelitian, dan adanya program pra komersialisasi. dengan kebijakan dan langkah strategis tersebut, diharapkan penelitian mobil listrik hibrid dapat memperoleh hasil yang lebih baik dan siap menuju tahap komersialisasi. ii. metodologi metodologi yang digunakan pada makalah ini adalah dengan melakukan pengumpulan dan analisis data primer dan sekunder. data primer dikumpulkan melalui wawancara dan diskusi dengan para peneliti yang terlibat dalam penelitian mobil listrik hibrid, pengambil kebijakan di lingkungan lipi dan pakar yang terkait dengan masalah otomotif. wawancara dan diskusi dilakukan untuk mengetahui perkembangan dan permasalahan penelitian mobil listrik hibrid yang dihadapi selama ini serta masukan yang diperlukan untuk mengatasinya. data sekunder dikumpulkan melalui studi literatur terhadap hasil kajian yang ada dan peraturan-peraturan yang berhubungan dengan legalitas penggunaan mobil listrik hibrid. berdasarkan analisis data-data tersebut, dirumuskan suatu masukan kebijakan yang perlu dilakukan baik oleh pengambil keputusan di lingkungan lipi maupun pemerintah untuk mendorong berkembangnya mobil listrik hibrid di indonesia. iii. hasil dan pembahasan a. kebijakan pemerintah untuk mendukung program nasional mobil listrik hibrid pemerintah indonesia kurang serius mendorong perkembangan mobil listrik hibrid di indonesia. hal ini ditunjukkan dengan tidak adanya dukungan untuk menjadikan program mobil listrik hibrid menjadi program nasional. berbeda dengan beberapa negara tetangga seperti thailand, malaysia, dan singapura yang telah bekerjasama dengan beberapa perusahaan dari negara lain untuk mengembangkan mobil listrik hibrid di negaranya. thailand yang diwakili oleh global electric motors car asia co., ltd., melakukan kerjasama dengan leo motors, inc., yang berbasis di korea selatan untuk pengembangan dan pemasaran mobil listrik di thailand. malaysia melakukan kerjasama dengan detroit electric dari belanda untuk mengembangkan prototipe kendaraan listrik, sedangkan singapura membentuk “kelompok kerja” dan memberikan bantuan dana untuk pengembangan mobil listrik hibrid serta melakukan kerjasama dengan “renault-nissan and keppel energy”. selain itu negara-negara seperti amerika, inggris, belanda, swiss, italia, india, dan china juga terus mendorong berkembangnya mobil listrik hibrid di negaranya dengan memberikan bantuan dana penelitian dan subsidi bagi masyarakatnya dalam pembelian mobil listrik hibrid [8]. dukungan pemerintah yang minim juga dapat dilihat dari anggaran penelitian yang sangat minim. ironisnya, di saat dana pendidikan cukup tinggi yaitu mencapai 20,2% pada apbn 2011 [9], dana penelitian justru cenderung turun dari waktu ke waktu. walaupun ekonomi indonesia secara umum tetap tumbuh, namun anggaran riset nasional terus menurun dimana pada tahun 1990 apabila dibandingkan anggaran riset dengan produk domestik bruto indonesia adalah sebesar 0,13% dan turun menjadi 0,08% pada tahun 2010. sebaliknya dalam periode yang sama, produk domestik bruto telah naik 30 kali lipat atau dalam harga konstan tumbuh rata-rata 7% sebelum krisis dan sekitar 5% setelah krisis ekonomi 1997. penurunan intensitas riset nasional disebabkan oleh beberapa faktor yang antara lain adalah investasi dana riset swasta yang rendah, jumlah terbesar industri adalah industri dengan kadar teknologi rendah dan menengah yang tidak memerlukan riset, dan perhatian pemerintah terhadap iptek yang menurun [10]. untuk mendukung program nasional mobil listrik hibrid, selain membutuhkan dana setidaknya diperlukan dua hal mendasar yaitu adanya road map nasional dan peraturan legalitas penggunaan mobil listrik hibrid. untuk lebih jelasnya akan dijabarkan seperti yang terdapat di bawah ini. 1) road map nasional untuk mendorong berkembangnya mobil listrik hibrid di indonesia, diperlukan adanya road map nasional mobil listrik hibrid yang jelas dan terarah agar dapat mensinergikan seluruh instansi terkait guna mendukung terbentuknya industri nasional mobil listrik hibrid. road map nasional tersebut memerlukan dukungan dari pemerintah pusat sebagai pembuat kebijakan dan regulator, industri manufaktur sebagai pihak yang akan berkecimpung langsung dalam proses produksinya serta perguruan tinggi dan lembaga penelitian yang berperan di bidang riset dan pengembangannya. dengan adanya road map nasional tentu akan menumbuhkan industri dalam r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 4 negeri khususnya industri mobil nasional beserta industri-industri pendukungnya seperti industri bahan baku, industri komponen dan peralatan serta industri-industri lainnya. untuk mendukung road map tersebut, pemerintah dapat berinvestasi dalam bentuk bantuan dana penelitian seperti yang dilakukan oleh negara lain seperti singapura, amerika dan lainnya. 2) legalitas mobil listrik hibrid kendaraan listrik hibrid adalah salah satu jenis kendaraan yang ramah lingkungan dan hemat energi. akan tetapi penerapannya di indonesia saat ini masih terkendala karena belum ada peraturan yang melegalkan penggunaan mobil listrik hibrid khususnya untuk penggunaaan di jalan raya. undang-undang no. 22 tahun 2009 belum mengakomodir legalitas penggunaan kendaraan listrik hibrid jalan raya apalagi kendaraan listrik baik motor maupun mobil. penggunaan kendaraan listrik hibrid di jalan raya saat ini masih mengacu peraturan pada peraturan kendaraan konvensional. tidak adanya peraturan yang melegalkan penggunaan kendaraan listrik hibrid menyebabkan keengganan masyarakat untuk menggunakan jenis kendaraan tersebut. oleh karena itu diharapkan adanya peraturan pemerintah sebagai turunan dari uu no. 22 tahun 2009 yang mengakomodir legalitas kendaraan listrik hibrid di jalan raya. dengan adanya peraturan pemerintah tersebut diharapkan dapat mendorong berkembangnya industri kendaraan listrik dan listrik hibrid dalam negeri khususnya industri motor listrik hibrid yang telah ada saat ini seperti betrix, fuboru, e motto, dan lainnya. b. kebijakan lipi dalam mendukung penelitian mobil listrik hibrid selain perlunya dukungan pemerintah, lipi juga perlu mengambil langkah-langkah strategis guna menunjang penelitian mobil listrik hibrid yang sedang berjalan saat ini. untuk itu diusulkan beberapa kebijakan yang perlu dilakukan oleh lipi antara lain adalah fokus penelitian, koordinasi penelitian dan adanya program pra komersialisasi hasil penelitian. untuk lebih jelasnya akan dijabarkan sebagai berikut. 1) fokus penelitian keberhasilan dari suatu penelitian terutama penelitian yang bersifat multi disiplin dan multi bidang seperti penelitian mobil listrik hibrid ini adalah dibutuhkannya fokus penelitian. agar penelitian mobil listrik hibrid dapat berhasil sesuai rencana, perlu dilakukan fokus penelitian pada bidang-bidang prioritas saja sehingga tidak harus melakukan penelitian seluruh komponen gambar 2. skema mobil listrik hibrid. mobil listrik hibrid tersebut. gambar 2 memperlihatkan beberapa komponen utama mobil listrik hibrid yang antara lain terdiri dari mesin bensin, generator, baterai, power converter, motor listrik, speed control, energy management system dan sistem pengisian. berdasarkan beberapa permasalahan yang ada seperti yang telah dijelaskan sebelumnya, diusulkan fokus penelitian yang perlu dilakukan oleh puslit telimek lipi adalah pada bagian speed control, generator, motor, dan sistem pengisian. dengan fokus penelitian pada empat komponen tersebut diharapkan teknologi yang dikuasai menjadi tidak global dan lebih mendalam atau spesifik serta prototipe hasil penelitian masing-masing komponen tersebut dapat lebih baik. perlunya fokus penelitian mobil listrik hibrid pada empat komponen tersebut adalah karena puslit telimek lipi telah memiliki pengalaman penelitian komponen itu sehingga tidak perlu melakukan penelitian dari awal lagi. penelitian speed control pernah dikerjakan di puslit telimek lipi, akan tetapi penelitian tersebut perlu dilanjutkan untuk mendapatkan hasil yang lebih baik. penelitian generator dan motor juga pernah dilakukan walaupun tidak spesifik untuk mobil listrik hibrid. dengan berbekal pengalaman penelitian yang pernah dilakukan tersebut dan untuk menunjang penelitian mobil listrik hibrid, perlu dilakukan penelitian mengenai generator dan motor dengan mengacu pada spesifikasi mobil listrik hibrid, sedangkan sistem pengisian perlu dilakukan penelitian lanjutannya agar menghasilkan sistem fast charging yang bentuknya lebih kecil dari yang sudah ada saat ini sehingga dapat diintegrasikan pada mobil listrik hibrid. selain itu, untuk menunjang penelitian mobil listrik hibrid sangat diperlukan peremajaan secara berkala terhadap sarana dan prasarana yang saat ini telah dimiliki oleh puslit telimek lipi. beberapa peralatan pengujian yang belum dimiliki oleh puslit telimek lipi seperti alat uji r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 5 baterai, alat uji speed control, dan test bag perlu untuk dilengkapi. dengan fokus penelitian ini, puslit telimek lipi dapat berperan lebih mendalam pada sektor penelitian dan pengembangannya saja, sedangkan untuk proses komersialisasi dapat diserahkan kepada pihak lain seperti industri manufaktur. selain untuk memperoleh hasil penelitian yang optimal, fokus penelitian juga dapat mengatasi masalah keterbatasan dana penelitian. anggaran penelitian yang sangat minim akan semakin berkurang karena sistem anggaran yang berlaku saat ini hanya sekitar 40% nilai pagu yang diajukan yang secara riil dapat digunakan untuk pengadaan bahan dan peralatan sedangkan 60% dari dana penelitian dipakai untuk gaji upah, perjalanan, pajak-pajak, dan potongan-potongan lainnya. bila dicoba suatu pola kerjasama antara lembaga penelitian seperti lipi dengan pihak swasta seperti industri juga akan sulit. menurut data dari survei pada tahun 2010 yang dilakukan pappiptek lipi, diketahui bahwa anggaran penelitian industri manufaktur terbesar yaitu mencapai 96% digunakan oleh litbang internal perusahaan tersebut, sedangkan sisanya yaitu 4% disediakan perusahaan untuk diberikan kepada instansi lain yang melakukan kegiatan litbang untuk kepentingan perusahaan tersebut [11]. bila dihubungkan relevansi kegiatan penelitian mobil listrik hibrid yang dilakukan oleh puslit telimek lipi dengan kebutuhan dari industri manufaktur, tentu akan cukup sulit untuk mendapatkan dana penelitian dari sektor industri manufaktur karena penelitian ini tidak mendukung kepentingan industri manufaktur tersebut. agar tidak membebani dana penelitian yang nilainya kecil, disarankan lembaga penelitian diberikan subsidi oleh pemerintah berupa pembebasan pajak terutama untuk bahan-bahan penelitian dan peralatan sehingga hasil penelitian dapat semakin optimal. keterbatasan dana penelitian selama ini menyebabkan hasil penelitian menjadi kurang optimal. skema block grant dapat diterapkan dimana dana diberikan secara utuh dan tidak dikenakan pemotongan pajak. mengingat pentingnya fokus kegiatan, direkomendasikan agar lipi dapat mengambil suatu kebijakan untuk memfokuskan kegiatan penelitian mobil listrik hibrid pada empat komponen seperti yang telah diuraikan di atas yaitu speed control, generator, motor, dan sistem pengisian. dengan fokus kegiatan penelitian yang telah ditentukan secara matang sesuai dengan kompetensi yang dimiliki oleh puslit telimek lipi diharapkan dapat mengatasi masalah yang dihadapi terutama masalah keterbatasan waktu, sumber daya manusia dan dana penelitian sehingga hasil penelitian mobil listrik hibrid menjadi lebih optimal. 2) koordinasi penelitian selama ini kurang adanya koordinasi pada penelitian-penelitian yang berkaitan dengan penelitian mobil listrik hibrid menyebabkan prototipe hasil penelitian tersebut tidak dapat diintegrasikan menjadi satu kesatuan pada prototipe mobil listrik hibrid. mobil listrik hibrid terdiri dari beberapa komponen yang saling berhubungan dan terintegrasi menjadi satu kesatuan. untuk itu dalam mendesain setiap bagian harus mempunyai spesifikasi yang telah ditentukan dari awal sehingga bagian yang lain dapat disesuaikan agar dapat digunakan dengan baik secara sistem. saat ini masing-masing bagian bekerja sendiri dengan spesifikasi yang tidak sesuai dengan kebutuhan mobil listrik hibrid sehingga setelah menjadi prototipe tidak dapat diintegrasikan. contoh kasus komponen gear transmisi, sistem pengisian fast charging, motor dc, dan electronic power steering karena spesifikasinya tidak sesuai dengan spesifikasi yang diperlukan oleh mobil listrik hibrid, maka komponen tersebut tidak bisa diintegrasikan sehingga saat ini beberapa komponen masih menggunakan komponen yang ada di pasaran. untuk itu diperlukan adanya koordinator program yang mengkoordinir bidang-bidang penelitian pada penelitian mobil listrik hibrid, baik penelitian yang dilakukan oleh puslit telimek maupun di luar puslit telimek. gambar 3 merupakan suatu contoh koordinasi penelitian yang diharapkan hasilnya dapat menuju satu tujuan yang konvergen. pada gambar 3, koordinator program dapat dibantu oleh tiga sub koordinator seperti: (1) sub koordinator bidang administrasi dan sdm yang bertugas mengkoordinir distribusi sdm penelitian, aturan kerjasama antar satuan kerja, dan mengatur sarana dan prasarana yang ada; (2) sub koordinator bidang anggaran yang bertugas mengkoordinir anggaran penelitian; serta (3) sub koordinator bidang penelitian teknis yang bertugas mengkoordinir sub-sub kegiatan penelitian di bawahnya. untuk mencapai hasil penelitian yang maksimal, diperlukan juga sinergi penelitian yang ada di bidang lain untuk dapat mendukung penelitian mobil listrik hibrid sehingga terkoordinasi dalam satu program. pada rencana strategis implementatif puslit telimek lipi tahun 2010-2014 sebenarnya telah tersusun sub-sub kegiatan yang bernaung di bawah kegiatan penelitian transportasi ramah lingkungan dengan konsep mobil listrik dan r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 6 gambar 3. bagan koordinasi penelitian mobil listrik hybrid. hibrid. renstra implementatif ini disusun berdasarkan pada rpjmn ii, renstra lipi tahun 2010-2014, dan renstra koordinatif kedeputian ilmu pengetahuan teknik [12]. untuk menunjang penelitian mobil listrik hibrid seperti pada renstra tersebut, disarankan sistem koordinasi kegiatan seperti yang disajikan pada gambar 3 dapat diterapkan sehingga terjalin koordinasi yang sinergi pada tiap sub kegiatan. 3) program pra komersialisasi hasil penelitian proses komersialisasi suatu hasil penelitian sebenarnya harus melewati tahapan yang relatif panjang mulai dari pemunculan gagasan, penyaringan gagasan, pengembangan dan pengujian konsep, pengembangan strategi pemasaran, analisis bisnis, pengembangan produk, pengujian pasar, dan komersialisasi [13]. akan tetapi secara ringkas model ideal pengembangan mobil listrik hibrid mulai dari tahap penelitian sampai komersialisasi ditampilkan pada gambar 4. pada gambar 4, tahap awal yaitu tahap riset dan pengembangan, lipi dapat berperan seluruhnya baik sdm maupun pendanaan. tahap selanjutnya yaitu pilot project atau tahap pra komersialisasi dimana pada tahap ini lipi dapat bekerja sama dengan pihak swasta dalam hal pendanaan, sedangkan pada tahap komersialisasi dan layanan purna jual, seluruhnya ditangani oleh pihak swasta dengan dukungan lipi sebagai tenaga ahlinya. untuk menuju tahap komersialisasi hasil penelitian mobil listrik hibrid, diperlukan suatu program inkubasi atau pra komersialisasi dalam bentuk pilot project yang ditujukan untuk meningkatkan nilai produk/prototipe hasil penelitian agar teruji kehandalannya. dari dana inkubasi tersebut, dapat dibuat beberapa contoh produk yang dapat dimanfaatkan langsung oleh pemakai sebagai uji coba sehingga dapat diketahui kekurangan atau kelemahannya untuk selanjutnya dilakukan perbaikan. pada tahap awal, contoh produk mobil listrik hibrid yang telah dibuat dapat digunakan oleh instansi-instansi pemerintah sebagai kendaraan operasionalnya. apabila secara teknis telah teruji kehandalannya, kemudian mengundang investor untuk masuk pada tahap komersialisasi. dalam kasus mobil listrik buatan puslit telimek lipi, program inkubasi ini tidak ada sehingga dari prototipe hasil penelitian langsung masuk ke tahap komersialisasi padahal produknya belum teruji secara baik. pada tahap pilot project atau pra komersialisasi, selain pengujian juga harus dilakukan studi kelayakan atau feasibility study. studi kelayakan bertujuan untuk menilai kelayakan implementasi sebuah bisnis sehingga dapat menjadi dasar yang kuat untuk mencegah hal-hal dapat merugikan di kemudian hari. pada kasus mobil listrik, karena terbatasnya dana penelitian menyebabkan belum dilakukannya studi kelayakan secara spesifik sehingga semuanya berjalan secara sederhana. tahap selanjutnya setelah program inkubasi adalah komersialisasi yang contoh produknya sudah teruji kehandalannya serta dilengkapi dengan studi kelayakan dan cetak biru yang lengkap. adanya studi kelayakan dan cetak biru dapat memberikan keyakinan lebih kepada calon investor untuk berinvestasi memproduksi mobil listrik hibrid tersebut. selain itu, untuk menunjang produk mobil listrik hibrid yang telah dipasarkan kepada masyarakat umum, diperlukan juga layanan purna jual yang didukung oleh ketersediaan suku cadang, jaringan bengkel yang memadai, dan tenaga teknisi yang terlatih. hal tersebut perlu dipersiapkan guna tercapainya kepuasan pelanggan. iv. kesimpulan penelitian mobil listrik yang dilakukan oleh puslit telimek lipi telah masuk sampai ke tahap komersialisasi. akan tetapi dalam perkembangannnya terdapat beberapa masalah r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 7 gambar 4. proses komersialisasi hasil penelitian. yang menyebabkan tidak berkembangnya produksi mobil listrik tersebut. hal ini dapat terjadi karena kurangnya dukungan pemerintah, keterbatasan peralatan laboratorium pengujian, sdm yang terbatas, dana penelitian yang kecil dan tidak adanya koordinasi penelitian sehingga hasil penelitian belum benar-benar terbukti secara teknologi. dukungan yang dibutuhkan dari pemerintah saat ini untuk mendorong berkembangnya mobil listrik hibrid di indonesia adalah adanya program penggunaan mobil listrik hibrid di dalam negeri. untuk menunjang program tersebut diusulkan adanya road map nasional sehingga dapat terbentuk industri nasional mobil listrik hibrid. selain itu, diperlukan juga legalitas penggunaan mobil listrik hibrid khususnya pemakaian di jalan raya melalui peraturan pemerintah. untuk intern lipi, agar penelitian mobil listrik hibrid seperti yang terdapat dalam rencana strategis implementatif puslit telimek lipi tahun 2010-2014 tidak mengalami hal yang sama seperti penelitian mobil listrik, maka diusulkan suatu kebijakan untuk mempercepat penguasaan teknologi sehingga penelitian mobil listrik hibrid dapat berlanjut sampai tahap komersialisasi. beberapa kebijakan yang diusulkan antara lain adalah perlunya fokus penelitian, koordinasi penelitian dan adanya program pra komersialisasi atau pilot project berupa program inkubasi yang dilengkapi dengan studi kelayakan dan cetak biru agar hasil penelitian mobil listrik hibrid benarbenar matang dan siap ke tahap komersialisasi dimana pada tahap komersialisasi ini lipi dapat kerjasama dengan pihak swasta. selain itu, untuk menunjang penelitian mobil listrik hibrid diperlukan juga peremajaan secara berkala peralatan yang telah dimiliki serta melengkapi peralatan pengujian yang belum dimiliki seperti alat uji baterai, alat uji speed control, dan test bag. referensi [1] bps. (2009) perkembangan jumlah kendaraan bermotor menurut jenis tahun 1987-2009. [online]. available: http://www.bps.go.id/tab_sub/view.php?tabe l=1&daftar=1&id_subyek=17&notab=12, diakses 23 november 2011. [2] index mundi. (2011) indonesia crude oil production and consumption by year. [online]. available: http://www.indexmundi.com/energy.aspx?co untry=id&product=oil&graph=production+c onsumption, diakses 27 januari 2012. [3] sekretariat jenderal kementerian keuangan, "media keuangan," apbn 2011 sebuah momentum menuju akselerasi, vol. 5, no. 39, p. 2, november 2010. [4] s. syahril, b.p. resosudarmo, h.s. tomo. (2002, september) study on air quality in jakarta, indonesia future trends, health impacts, economic value and policy options, indonesia. [online]. available: http://www.adb.org/documents/studies/air_ quality_ino/air_quality.pdf, diakses 14 desember 2011. [5] a. safrudin, r. noviantara, "fuel gases for transport options to reduce vehicular emissions in indonesia," jakarta, 2011. [6] a. bandivadekar et al. (2008, july) on the road in 2035 reducing transportation’s petroleum consumption and ghg emissions. [online]. available: http://web.mit.edu/sloan-autolab/research/beforeh2/otr2035/on%20the%2 0road%20in%202035_mit_july%202008. pdf, diakses 14 desember 2011. [7] puslit telimek lipi, "laporan akuntabilitas kinerja instansi pemerintah puslit telimek," puslit telimek lipi, bandung, laporan tahunan 2000-2010. riset & pengembangan pilot project komersialisasi layanan purna jual prototipe contoh produk produk kepuasan pelanggan pengujian pengujian, fs dan blue print promosi suku cadang, bengkel & sdm r.a. subekti et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 1-8 8 [8] m. kasim, et al., “kebijakan nasional mobil listrik hibrid,” agus hartanto, ed. bandung, indonesia: lipi press, 2010. [9] menteri hukum dan hak asasi manusia republik indonesia. (2010, november) undang-undang republik indonesia nomor 10 tahun 2010 tentang anggaran pendapatan dan belanja negara tahun anggaran 2011. [online]. available: http://www.anggaran.depkeu.go.id/peraturan /uu%2010%20-%202010%20%20apbn%202011.pdf, diakses 27 januari 2012. [10] e. aminullah, "dinamika dana riset nasional dan pertumbuhan ekonomi indonesia jangka panjang," pada seminar pappiptek, jakarta, 2011, pp. 6-14. [11] n.g. simamora, "mengungkap fakta r&d indonesia," pada seminar pappiptek, jakarta, 2011, pp. 15-35. [12] puslit telimek lipi, “rencana strategis implementatif 2010-2014,” tinton dwi atmaja, ed. bandung, indonesia: puslit telimek lipi, 2010. [13] p. kotler, k.l. kelle, “marketing management,” 12th ed. new york, us: prentice hall, 2006. microsoft word vol02_no1 journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 1, 2011 issn: 2088-6985 (online) iii editorial board of journal of mechatronics, electrical power and vehicular technology editor-in-chief dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com executive editor dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id pudji irasari, m.sc.rer.nat. electrical engineering/electric machines indonesian institute of sciences pudji.irasari@lipi.go.id managing editor ghalya pikra, m.t. mechanical engineering indonesian institute of sciences ghalyapikra@yahoo.com naili huda, m.eng.sc. industrial engineering indonesian institute of sciences naili.huda@lipi.go.id noviadi arief rachman, m.t. electrical power engineering indonesian institute of sciences novi001@lipi.go.id tinton dwi atmaja, m.t. electrical engineering, informatics indonesian institute of sciences tinton_dwi@yahoo.com peer reviewer prof.dr. satryo soemantri brodjonegoro mechanical engineering bandung institute of technology satrio1@indo.net.id prof.dr. jamasri mechanical and industrial engineering gajah mada university, yogyakarta jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering bandung institute of technology suhono@stei.itb.ac.id dr. endra joelianto engineering physics, instrumentation & control bandung institute of technology ejoel@tf.itb.ac.id dr. yuliadi erdani information, computer science polteknik manufaktur bandung yul_erdani@polman-bandung.ac.id ir. arko djajadi, ph.d. mechatronics engineering swiss german university, serpong arko@sgu.ac.id dr. eng. tri agung rochmat mechanical engineering gajah mada university, yogyakarta triagung_rohmat@ugm.ac.id dr. ahmad agus setiawan renewable energy systems gajah mada university, yogyakarta a.setiawan@ugm.ac.id ir. edi leksono, m.eng. ph.d. physics engineering bandung institute of technology edi@tf.itb.ac.id dr. ir. iman kartolaksono reksowardojo mechanical engineering bandung institute of technology iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. mechatronics engineering stkip surya, serpong riza.muhida@stkipsurya.ac.id journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 1, 2011 issn: 2088-6985 (online) iv tata cara penulisan redaksi menerima naskah karya tulis ilmiah yg berupa hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya.aturan penerbitannaskah adalah sebagai berikut: 1. naskah dikirim melalui e-mail ke sekretariat@mevjournal.com atau dapat melalui pos ke alamat sekretariat menyertakan 2 buah hardcopy dan 1 buah softcopy. 2. sistematika penulisan terdiri dari: a. judul; title case, small caps, centered, bold, times new roman (tnr) 16, spasi 1. b. nama penulis; tanpa gelar, centered, bold, tnr 12, spasi 1. penulis ganda dengan instansi berbeda dibedakan dgn penomoran angka superscript (1) c. alamat instansi dan e-mail; centered, tnr 10, spasi 1. d. abstrak ditulis dalam bahasa indonesia dan bahasa inggris. judul dalam bahasa indonesia adalah abstrak, sedangkan dalam bahasa inggris adalah abstract; justified, bold, tnr 12, spasi 1. e. isi abstrak singkat, jelas, dan tidak melebihi 200 kata tanpa memuat gambar atau tabel; justified, tnr 10, spasi 1. f. kata kunci atau keyword terdiri dari 2-5 kata dipisahkan koma; justified, tnr 10, spasi 1. g. isi naskah; ditulis dalam 2 (dua) kolom, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. 3. aturan pembaban disusun dalam empat bagian: pendahuluan, isi makalah, hasil dan pembahasan, serta kesimpulan. diikuti ucapan terima kasih (bila diperlukan) dan daftar pustaka. pengaturan heading adalah sebagai berikut. a. heading pertama ditulis dengan format; title case, small caps, rata kiri, bold, tnr 14, spasi 1, dengan penomoran romawi diikuti titik (contoh: i. pendahuluan) b. heading kedua ditulis dengan format; title case, rata kiri, bold, tnr 11, spasi 1, dengan penomoran huruf besar diikuti titik (contoh: a. pengujian) c. heading ketiga ditulis dengan format; title case, rata kiri, italic, tnr 11, spasi 1, dengan penomoran angka diikuti kurung tutup (contoh: 1) pengujian lapangan) d. heading keempat tidak direkomendasikan, namun masih bisa diterima dengan format; sentence case, justified, left indent 5 mm hanging indent 5 mm, italic, tnr 11, spasi 1, dengan penomoran huruf kecil diikuti kurung tutup. (contoh: a) hasil pengujian lapangan) e. heading kelima tidak dapat diterima 4. gambar, grafik dan tabelharus terbaca dengan jelas, diberi nomor urutdan keterangan ringkas, tnr 11, spasi 1. gambar harus disertai keterangan gambar dalam isi naskah. file gambar/grafik/tabel disertakan dalam folder terpisah dengan format (.tif/.jpg/.jpeg). 5. daftar pustaka;semua buku atau tulisan yang menjadi referensi harus diberi nomor dengan format [1], [2], [3], dst. referensi di akhir tulisan sesuai urutan kemunculannya dalam tulisan. pengambilan referensi yang bersumber dari electronic sources, harus mencantumkan, 1) protocol atau pelayanan, 2) lokasi, dimana item tersebut ditemukan, 3) item dapat didapatkan kembali. tidak diperkenankan mengambil acuan dari sumber sejenis wikipedia, blog pribadi atau situs lain yang tidak bersifat ilmiah. tata cara penulisan daftar pustaka secara lebih lengkap dapat mengikuti contoh-contoh pada ‘layout penulisan makalah’ di website jurnal atau sesuai tata cara penulisan referensi ieee. 6. persamaan matematik harus ditulis dengan jelas, diberi nomor urut, dan diberi keterangan notasi-notasi yang dipergunakan. 7. panjang naskah naskah minimal 2.000 kata dan tidak lebih dari 10 halaman, termasuk gambar dan tabel tanpa lampiran. naskah direkomendasikan diketik menggunakan word processor baik open office text document (.odt) atau microsoft office word (.doc/.docx) dengan format margin 2 cm untuk tepi atas, kanan dan bawah serta 2,5 cm untuk tepi kiri pada kertas ukuran a4. dewan editor berhak menolak suatu naskah yang dianggap tidak memenuhi syarat, setelah mendengar pendapat para ahli. dewan editor berhak mengubah dan menyesuaikan bahasa dan istilah tanpa perubahaan isi, dengan tidak memberitahukan kepada penulis terlebih dahulu. jika perubahaan isi dianggap perlu, maka akan dikonsultasikan dengan penulis dewan editor kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 105-112, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.105-112 penggunaan perangkat lunak open source untuk sistem open architecture pada mesin milling cnc the use of open source software for open architecture system on cnc milling machine dalmasius ganjar subagio dan tinton dwi atmaja pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia. tinton_dwi@yahoo.com diterima: 28 oktober 2011; direvisi: 2 november 2011; disetujui: 19 desember 2011; terbit online: 22 desember 2011. abstrak sistem kerja mesin computer numerical control (cnc) milling tidak dapat terlepas dari perangkat lunak sebagai penerjemah bahasa operator ke bahasa mesin. perangkat lunak ini dituntut untuk mengikuti ketentuan open architecture yang antara lain mempunyai kapabilitas portability, extendability, interoperability, dan scalability. proses manufaktur modern terkadang menggunakan mesin cnc milling untuk waktu yang lama bahkan melebihi waktu kerja yang ditentukan oleh produsen. ketika mesin sudah melewati masa yang ditentukan dan produsen memutuskan discontinue, maka pengguna akan menemui masalah untuk mempertahankan kinerja mesin jika diharuskan tetap tergantung pada perangkat lunak bawaan dari produsen. tulisan ini bertujuan menunjukkan bahwa penggunaan open source software (oss) adalah jalan keluar untuk mempertahankan kinerja mesin. dengan penggunaan oss, pengguna tidak lagi tergantung pada perangkat lunak dari produsen karena oss bersifat terbuka dan dapat dikembangkan secara mandiri. dalam tulisan ini dipergunakan usbcnc v.3.42 sebagai alternatif oss pada mesin cnc milling. oss ini menunjukkan hasil uji coba benda kerja yang sesuai dengan pola yang diinginkan. hasil uji coba menunjukkan kinerja mesin dengan oss serupa dengan kinerja mesin ketika menggunakan perangkat lunak dari produsen. kata kunci: mesin cnc milling, open architecture, open source software. abstract computer numerical control (cnc) milling machine system can not be separated from the software required to follow the provisions of the open architecture capabilities that have portability, extendability, interoperability, and scalability. when a prescribed period of a cnc milliing machine has passed and the manufacturer decided to discontinue it, then the user will have problems for maintaining the performance of the machine. this paper aims to show that the using of open source software (oss) is the way out to maintain engine performance. with the use of oss, users no longer depend on the software built by the manufacturer because oss is open and can be developed independently. in this paper, usbcnc v.3.42 is used as an alternative oss. the test result shows that the workpiece is in match with the desired pattern. the test result shows that the performance of machines using oss has similar performance with the machine using software from the manufacturer. keywords: cnc milling machine, open architecture, open source software. i. pendahuluan teknologi di bidang manufaktur berkembang sangat pesat dalam beberapa tahun terakhir ini. mesin computer numerical control (cnc) merupakan mesin yang tergolong canggih, sehingga banyak sekali digunakan dalam industri pemesinan untuk memproduksi komponen dengan tingkat kerumitan dan presisi yang tinggi. selain itu, mesin cnc mempunyai konsistensi yang lebih efektif untuk pengerjaan dalam jumlah banyak. penggunaan mesin cnc konvensional dalam proses pemotongan, pengeboran, pengetapan dan proses pemesinan lainnya, tentu saja memberikan hasil yang tidak presisi dan memerlukan waktu cukup lama dikarenakan hasil produksi akan tergantung dari kemampuan operator dalam melakukan proses tersebut. gambar 1 merupakan contoh mesin cnc frais/milling yang banyak terdapat di industri pemesinan, dimana mesin tersebut telah dilengkapi dengan kontrol penggerak untuk proses kerja pemesinan [1][2]. mesin cnc milling tersebut mampu mengerjakan bentukbentuk yang tidak mungkin dikerjakan oleh http://dx.doi.org/10.14203/j.mev.2011.v2.105-112 penggunaan open source software untuk sistem open architecture pada mesin cnc milling (dalmasius ganjar subagio, tinton dwi atmaja) jmev 02 (2011) 105-112 106 gambar 1. mesin cnc frais/milling. mesin frais konvensional karena dilengkapi oleh kontrol penggerak yang dapat diperintah oleh program atau kode standar umum. manfaat mesin cnc yang signifikan menciptakan kebutuhan atas kinerja mesin yang konsisten bahkan disaat mesin telah tidak lagi dikembangkan (discontinue). ketika masa ini datang, pengembangan perangkat lunak akan menjadi masalah jika tetap memaksakan untuk menggunakan perangkat lunak berlisensi dari produsen asli. perangkat lunak lama akan bermasalah dengan kinerjanya yang harus uptodate terhadap kebutuhan yang terus meningkat. kadang dituntut untuk interoperable dengan perangkat yang lebih baru. hal ini akan meningkatkan pos pembiayaan tidak terduga demi mempertahankan kinerja mesin seperti ketika masih menggunakan perangkat lunak keluaran produsen. ketika pengguna memaksakan diri untuk menghubungi produsen, maka akan muncul faktor penundaan waktu produksi karena produsen memerlukan waktu untuk mendapatkan kembali perangkat lunak yang dipesan lengkap dengan kondisi ter-update. dalam tulisan ini akan di bahas mengenai pengembangan open architecture cnc milling machine terutama dalam pemilihan perangkat lunak program/kontrol penggerak guna mengurangi biaya pembuatan dan mengurangi ketergantungan degan produsen dengan tidak mengabaikan fungsi dari mesin cnc milling tersebut. perangkat lunak kontrol penggerak yang digunakan adalah open source software (oss) jenis freeware controller yang dapat diunduh dan di-update. fungsinya sama dengan perangkat lunak kontrol penggerak berbayar yang banyak digunakan pada industri manufaktur saat ini seperti: siemen, fanuc, okuma dan lain-lain. ii. oss pada open architecture mesin milling cnc pada tahun 90-an, “technical committee of open systems” dari ieee mendefinisikan open system sebagai sebuah sistem terbuka yang menyediakan kapabilitas yang memungkinkan aplikasi yang diimplementasikan dapat berjalan dalam berbagai platform dari berbagai vendor, interoperate dengan sistem aplikasi lainnya dan menyediakan gaya yang konsisten dalam berinteraksi dengan pengguna [3]. estimasi kapabilitas dari keterbukaan sistem open architecture dikemukakan dalam empat hal berikut [4][5]. • portability; modul aplikasi dapat digunakan pada platform yang berbeda tanpa ada perubahan dengan tetap mempertahankan kemampuan kerjanya. • extensibility; sejumlah modul aplikasi dapat berjalan dalam satu platform tanpa menimbulkan konflik. • interoperability; modul-modul dapat bekerja sama satu sama lain dalam suatu perlakukan yang konsisten dan dapat bertukar data dalam cara yang telah terdefinisikan. • scalability; fungsi, kinerja, dan ukuran fisik modul dapat beradaptasi sesuai dengan kebutuhan pengguna. banyak teknologi open architecture cnc dikembangkan berdasarkan pada microsoft windows, sebuah 32-bit embedded control system yang cocok untuk manajemen tugas-tugas umum [6][7]. dengan kemajuan terbaru dalam teknologi elektronik dan informasi, perangkat keras pengendali gerak telah menggunakan mikroprosesor dan memiliki digital signal processor (dsp), field programmable gate array (fpga) atau aplikasi sirkuit terpadu lainnya sebagai pendukung. pengembangan open architecture cnc milling machine juga mengadopsi struktur master-slave menggunakan pc dan modul numerical control (nc) yang masing-masing dirancang khusus sebagai master dan slave. modul slave nc menjalankan tugastugas kontrol real-time, seperti kontrol gerakan sumbu pada dsp dan fpga, sedangkan pc master menjalankan tugas-tugas non real-time seperti penjadwalan, pemantauan input/output dan on-screen simulation [8]. a. alur kerja mesin miling cnc alur kerja mesin milling ini dianalisis untuk menghasilkan alur sistem kendali yang diinginkan. mesin cnc (computer numerical control) pada dasarnya merupakan gabungan antara mekanik dan elektronik dimana informasi pergerakan mesin didapatkan berdasarkan kodekode yang dapat dibaca oleh mesin cnc tersebut. informasi ini bersifat digital dan digunakan sebagai acuan untuk menggerakkan motor (stepping motor atau servo motor) sesuai dengan journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 105-112, 2011 p-issn 2087-3379 107 gambar 2. alur kerja mesin cnc milling. gambar 3. contoh tampilan perangkat lunak berlisensi pada monitor mesin cnc milling [14]. yang diinginkan melalui driver. dari gambar 2 dapat kita lihat bahwa modul computer design memiliki hubungan erat dengan operator dan mesin cnc. operator hanya membuat suatu gambar menggunakan sistem computeraided design (cad) atau computer aided manufacturing (cam) dimana gambar tersebut berisi informasi mengenai bentuk dan ukuran yang dikehendaki oleh operator. modul cnc controller merupakan perangkat keras yang berfungsi sebagai penerima kodekode dari modul computer design dan menterjemahkannya ke dalam instruksi atau perintah dalam bentuk bahasa yang dapat diterima oleh mesin cnc. pada umumnya mesin cnc ini menggunakan sumbu x, y dan z untuk mesin frais (milling 3 axis). hasil terjemahan dari modul cnc controller ini kemudian diterima oleh modul servo drive. modul driver ini akan meneruskan instruksi kepada motor-motor penggerak mesin cnc sesuai dengan sumbu kerjanya. dalam prinsip kerja mesin cnc milling ini, spindle motor current akan dideteksi dan diolah untuk mendapatkan pergerakan pemotongan yang konstan dengan mengapplikasikan fuzzy logic controller (flc) [9]. teknologi multi-agent dipakai untuk meningkatkan performa distribusi sistem sebagai suatu bagian intelligent mechatronic system (ims) generasi baru. dasar keberhasilan ims adalah kemampuan setiap intelligent agent untuk berkomunikasi dan bekerjasama antar agen [10][11][12]. dengan ims ini, dapat diperoleh ultra-precision motion control, proses manufaktur kecepatan tinggi, dan penyelesaian berkualitas tinggi dengan biaya rendah dengan reliability yang lebih baik [13]. b. perangkat lunak mesin cnc milling berdasar pada definisi the open systems architecture, perangkat lunak dirancang dan diimplementasikan dengan human machine interface (hmi) yang user-friendly sehingga memerlukan perhatian lebih pada penampakan visualnya. perangkat lunak ini juga harus mudah dioperasikan, dan dapat memenuhi kebutuhankebutuhan operator yang beragam [16]. perangkat lunak yang dapat digunakan dalam pengoperasian mesin cnc milling dapat berupa perangkat lunak yang berbayar atau perangkat lunak open source.perangkat lunak yang berbayar atau licensed software biasanya merupakan bawaan dari mesin dan mendapat update dan pengembangan berkala dari produsennya. gambar 3 menunjukkan tampilan perangkat lunak berlisensi gsk 983m yang ditanam pada mesin cnc milling. masalah akan terjadi ketika banyak mesinmesin cnc milling yang sudah tidak diproduksi lagi membutuhkan pemeliharaan perangkat lunak. oleh karena itu perangkat lunak open source menjadi sebuah alternatif yang cukup menjanjikan demi kelangsungan kinerja mesin. gambar 4 menunjukkan tampilan open source software yang digunakan sebagai retrofit perangkat lunak berbayar. oss yang digunakan disini adalah usbcnc v.3.42 [15]. c. standard g-code penggunaan oss tidak dapat dipisahkan dari penggunaan kode yang sudah terstandarisasi untuk membantu penentuan tingkat keakuratan hasil yang diperoleh. tabel 1 menunjukkan gcode sebagai kode standar yang digunakan untuk membuat program cnc milling secara populer melebihi penggunaan bahasa lainnya seperti step-nc [17]. pada sistem ini, masih memungkinkan penggunaan step-nc karena perangkat lunak yang digunakan dapat menerjemahkan bahasa step-nc ke bahasa g-code [18][19]. fitur ini mendukung faktor portability sebagai salah satu kapabilitas sistem open architecture yang harus dipenuhi. servo drives computer design cnc controller programmer mesin cnc penggunaan open source software untuk sistem open architecture pada mesin cnc milling (dalmasius ganjar subagio, tinton dwi atmaja) jmev 02 (2011) 105-112 108 tabel 1. keterangan standar g code. kode keterangan kode keterangan g00 pindah posisi axis dengan kecepatan penuh g83 counter bore dengan waktu tunda g01 pindah posisi axis secara linear (feed rate) g84 pengetapan (tapping) g02 berputar searah jarum jam g85 reamer g03 berputar berlawanan arah jarum jam g86 boring g04 waktu tunda (dwell) g90 absolute g17 melingkar x-y dipakai pada g02 dan g03 g91 incremental g18 melingkary-z dipakai pada g02 dan g03 g92 koordinat referensi benda kerja g19 melingkar x-z dipakai pada g02 dan g03 g98 pengembalian pahat pada z awal g28 mengembalikan keposisi otomatis g99 pahat pada jarak yg ditentukan (r) g40 pembatalan kompensasi diameter pahat m02 spindle stop g41 kompensasai diameter pahat kiri m03 spindle berputar searah jarum jam g42 kompensasai diameter pahat kanan m04 spindle berputar berlawanan arah jarum jam g43 kompensasi panjang arah positif m05 spindle dan pendingin stop g44 kompensasi panjang arah negatif m06 pergantian tool g49 pembatalan kompensasi panjang pahat m08-m09 on dan off pompa pendingin g54 g59 sistem koordinat m30 akhir program g80 membatalkan fixed cycle m98 masuk ke sub program g81 fixed cycle untuk pengeboran (drilling) m99 keluar ke sub program gambar 4. tampilan monitor usb cnc milling [15]. gambar 5. hasil rancang bangun mesin cnc milling di p2 telimek-lipi. iii. implementasi oss dan uji coba tahap berikutnya adalah melakukan implementasi dan uji coba oss pada open architecture cnc milling machine. pertama adalah menyiapkan perlengkapan ujicoba, membuat program cnc dan menguji coba mesin pada benda kerja. a. perlengkapan uji coba aparatus yang akan digunakan adalah mesin cnc milling hasil penelitian dan rancang bangun yang dilaksanakan di p2 telimek – lipi seperti ditunjukkan gambar 5. mesin cnc ini dengan menggunakan freeware controller usbcnc v.3.42 berbasis oss. mesin tersebut di buat dengan menggunakan komponen lokal dan beberapa komponen impor (gambar 5). teori pendukung dalam proses rancang bangun mesin cnc milling ini diantaranya ilmu bahan dalam menentukan konstruksi mesin dan pemilihan benda kerja. hal-hal yang harus di perhatikan dalam pemilihan bahan sebuah komponen mesin adalah fungsi, pembebanan dan umur, kemampuan untuk dibentuk dan diproduksi, ongkos produksi dan mudah didapat dipasaran. pada umumnya pemilihan bahan tersebut dapat berdasarkan tabel bahan standar misalnya [20]: 1. bahan untuk poros dan gardan digunakan baja karbon st 60. 2. bahan untuk poros engkol (crankshaft) digunakan baja kualitas tinggi atau besi cor khusus. 3. bahan untuk pasak dan pegas digunakan st 60. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 105-112, 2011 p-issn 2087-3379 109 4. bahan roda gigi bergantung kepada pembebanan dan ukuran komponen. disini digunakan bahan seperti besi cor kelabu, besi cor baja, baja st 42 – st 70 kadangkadang digunakan bahan non logam atau bahan sintetis. 5. bahan untuk baja pemotong digunakan bahan baja perkakas yang di keraskan. 6. bahan konstruksi ringan dapat digunakan besi cor kelabu. disamping ilmu bahan juga digunakan digunakan teori pendukung untuk menghitung gaya-gaya yang terjadi pada suatu komponen yang tidak di bahas dalam tulisan ini. b. pembuatan program cnc arsitektur yang akan digunakan dalam proses kendali ini mengutamakan tiga proses utama yaitu samppling, filtering, dan processing data untuk menghasilkan sinyal kendali [21]. susunan perintah akan dibuat dalam bentuk teks dalam bahasa g-code yang disesuaikan dengan perangkat lunak yang dipergunakan. terdapat dua cara dalam membuat listing program yang berisi perintah yaitu menggunakan notepad atau menggunakan cad/cam. kedua cara tersebut diawali dengan pengetikan susunan perintah dalam g-code. ketika menggunakan perangkat lunak bawaan, seperti fanuc,contoh format program yang biasa digunakan sebagai berikut : g90 g00 g54 x0. y0.z50. m03 s2000 m08 g00 z5. go1 z-0,5 f100 - line omitted - g00 z50. g91 g28 x0. y0. z0. m30 sedangkan jika menggunakan software controller usbcnc v.3.42, format penulisan adalah seperti berikut: n106g0g90g54x.375y3.249z50.s5000m3 n110z5. n112g1z-.2f20. - line omitted - n7550g0z5. n7552z50. n7554m5 n7556g91g28x0.y0.z0. n7560m30 ketika menggunakan notepad, susunan perintah dapat diketik langsung dalam program notepad kemudian disimpan dengan nama file; misalnya: “percobaan” dengan format ekstensi ‘cnc’, contoh: “percobaan.cnc”. maka file tersebut akan dapat dieksekusi oleh mesin cnc milling. cara lain adalah dengan memasukkan susunan perintah tersebut kedalam cad/cam kemudian di simpan langsung dengan format file ‘cnc’, contoh: “percobaan.cnc”. maka file tersebut juga dapat dieksekusi langsung oleh mesin cnc milling. c. uji coba mesin uji coba mesin dilakukan setelah mesin selesai dirangkai, baik konstruksi mekanik maupun bagian kontrol penggerak. setelah mesin selesai terpasang kemudian dicoba untuk data program untuk mengoperasikan mesin. langkah pertama adalah menentukan pola yang akan digambarkan pada benda kerja. gambar 6 menunjukkan pola yang akan di ukir pada benda kerja. kemudian pola tersebut diterjemahkan kedalam g-code dan dimasukkan kedalam open source software. gambar 7 merupakan tampilan proses kerja mesin dari data gambar 6. pola kerja yang akan di proses. gambar 7. tampilan user interface oss. penggunaan open source software untuk sistem open architecture pada mesin cnc milling (dalmasius ganjar subagio, tinton dwi atmaja) jmev 02 (2011) 105-112 110 gambar 8. proses uji coba mesin. gambar 9. benda kerja hasil uji coba. yang diperoleh dari hasil cad/cam. setelah mesin dieksekusi, maka pola pada gambar 6 akan dieksekusi oleh oss seperti gambar 7. kemudian diterjemahkan kedalam bahasa mesin yang dibaca oleh mesin cnc milling untuk melakukan kegiatan seperti ditunjukkan pada gambar 8. gambar 8 menunjukkan proses milling ketika program diuji-cobakan kepada benda kerja. iv. hasil uji coba dan pembahasan berdasarkan hasil uji coba mesin dengan menggunakan kontrol usbcnc ternyata produk yang dihasilkan sesuai dengan gambar kerja yang direncanakan. gambar 9 menunjukkan benda kerja hasil uji coba mesin cnc milling menggunakan oss. pendeteksian dan pengolahan sinyal spindle motor current serta penggunaan flc telah mempertahankan kesinambungan proses pemotongan. penggunaan teknologi multi-agent meningkatkan performa distribusi sistem sebagai suatu bagian ims dapat dilihat dari kemudahan pengumpulan instruksi dalam bahasa mesin dan peningkatan kemampuan monitoring. penggunaan g-code tidak menimbulkan masalah karena kebanyakan perangkat lunak saat ini sudah terintegrasi dengan varian-varian gaya penulisan instruksi gcode. teknologi open architecture memungkinkan pengembang dan operator mesin untuk mengimplementasikan dan mengintegrasikan perangkat keras dan perangkat lunak yang berbeda dari berbagai vendor dalam satu platform dengan tetap mempertahankan antarmuka pengguna yang efektif. dalam hal ini, oss sangat mendukung faktor portability dan extendability, bahkan untuk faktor interoperability, oss dapat dengan mudah dimodifikasi untuk dapat saling bertukar data antar modul. faktor scalability tidak terlalu berpengaruh ketika dilihat dari sisi perangkat lunak, namun begitu skala besar dilihat dari biaya pengadaan perangkat lunaknya, maka oss dapat menghemat biaya pengadaan secara signifikan. efektivitas biaya oss pada open architecture sangat tinggi selain dari biaya pengadaan/akuisisi yang lebih rendah daripada perangkat lunak berbayar, biaya support untuk pengembangan dan pengujian dapat dihemat jika dilakukan pengembangan personel it mandiri. mesin-mesin berbasis oss akan mampu dipelihara secara mandiri tanpa tergantung pada layanan purna jual produsen. tingkat kemudahan pemakaian oss akan tergantung pada pengembangan sumber daya manusianya. operator pastinya terbiasa menggunakan perangkat lunak bawaan dari produsen. user interface dari oss tentunya akan membuat operator yang terbiasa menggunakan perangkat lunak bawaan produsen membutuhkan waktu adaptasi. proses adaptasi operator akan memakan waktu sehingga dalam skala besar akan menimbulkan hambatan tersendiri dalam proses produksi. jalan keluarnya adalah melakukan manajemen perubahan dan pelatihan yang terencana sehingga penggunaan mesin tetap optimal. keamanan pada oss lebih menjanjikan daripada perangkat lunak berbayar. oss mempunyai patch yang lebih sedikit daripada perangkat lunak berbayar. lebih sedikit patch artinya lebih sedikit isu dan ancaman dari luar. virus-virus yang dibuat untuk berjalan pada platform umum akan kesulitan untuk berjalan pada platform open source. sehingga dapat disimpulkan bahwa oss mempunyai resiko keamanan yang lebih rendah daripada perangkat lunak bawaan produsen. tabel 2 menunjukkan parameter kinerja mesin yang menggunakan open source software dibandingkan dengan mesin yang menggunakan software berbayar. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 105-112, 2011 p-issn 2087-3379 111 tabel 2. perbandingan penggunaan mesin dengan open source software dan mesin dengan software berbayar. parameter mesin menggunakan open source software mesin menggunakan software berbayar portability compatible compatible extendability compatible compatible interoperability compatible compatible scalability compatible compatible antarmuka pengguna butuh adaptasi mudah dipahami keamanan beresiko rendah beresiko tinggi biaya pengadaan/akuisisi perangkat lunak biaya rendah biaya tinggi biaya pemeliharaan perangkat lunak support yang hemat support yang berkesinambungan pemeliharaan mesin dapat dilakukan mandiri tergantung pada produsen v. kesimpulan penggunaan open source sofware adalah alternatif yang telah teruji sebagai pengganti perangkat lunak berbayar bawaan dari produsen. open architecture cnc milling machine mempunyai prinsip portability, extendability, interoperability, dan scalability dimana open source sofware dapat menyajikannya dengan tidak mengurangi kinerja mesin cnc milling. oss yang digunakan adalah usbcnc dengan menggunakan g-code yang diterapkan pada prototipe mesin cnc milling 3 sumbu yang dikembangkan oleh pusat penelitian tenaga listrik dan mekatronik. hasil pengujian pada benda kerja aluminium menunjukkan pola yang dihasilkan sesuai dengan pola yang direncanakan. sehingga secara kinerja, oss dapat menterjemahkan perintah operator kepada mesin serupa dengan perangkat lunak berbayar. mengaplikasikan oss pada cnc milling machine secara umum tetap dapat mendukung empat prinsip dasar open architecture dengan memunculkan keuntungan dan kerugian tersendiri. keuntungan akan muncul dari segi biaya akuisisi, pemeliharaan, dan keamanan. pemeliharaan mesin akan lebih mandiri tanpa tergantung pada layanan produsen terutama pada produk discontinue. kelemahan akan muncul pada faktor adaptasi operator yang nantinya memerlukan manajemen perubahan dan pelatihan yang terencana. ucapan terimakasih penulis berterima kasih kepada dian andriani dan siti fausiyah rahman dari chonnam national university atas sumbangan kajian internasionalnya. juga kepada peneliti dari gwangju institute of science and technology, dan university of adelaide yang telah mendukung banyak hal dalam tulisan ini. penulis juga berterima kasih kepada vita susanti dan semua peneliti pusat penelitian tenaga listrik dan mekatronik – lipi yang belum dapat disebutkan satu persatu yang telah banyak membantu terselesaikannya tulisan ini daftar pustaka [1] suryaputra, (2008, december) teknik permesinan. [online]. available: http://suryaputra.edublogs.org/2008/12/20/te knik-frais-dasar/ [dikutip: 25 oktober 2011] [2] suzhou sunda machine tools co., ltd. machine tools cnc milling machine. [online]. available: http://www.sundamachinetools.com/cncmilling-machine/ [dikutip: 25 oktober 2011] [3] institute of electrical and electronics engineers, 1003.0-1995; ieee guide to posix open system environment (ose).: ieee computer society, 1995. [4] pengfei li, tao gao, jianping wang, hongzhao liu, "open architecture of cnc system research based on cad graphdriven technology," robotics and computer-integrated manufacturing, volume 26, issue 6. pp. 720–724, december 2010. [5] günter pritschow, co-ordinator, yusuf altintas, francesco jovane, yoram koren, mamoru mitsuishi, shozo takata, hendrik van brussel, manfred weck, kazuo yamazaki, "open controller architecture past, present and future," cirp annals manufacturing technology, volume 50, issue 2, pp. 463-470, 2001. [6] z. wang, e. gao and y. zhang, "a windows ce-based open-architectured cnc system," manufacturing automation, volume 23, issue 9, pp. 1-4, 2005. [7] s. xiao, d. li, y. lai, j. wan and s. feng, "an open architecture numerical control system based on windows ce," in penggunaan perangkat lunak open source untuk sistem open architecture pada mesin milling cnc (dalmasius ganjar subagio, tinton dwi atmaja) jmev 02 (2011) 105-112 112 proceeding of ieee international conference on control and automation, guangzhow, prc, june 2007, pp. 12371240. [8] k. ekkachai, u. komin, w. chaopramualkul, a. tantaworrasilp, p. kwansud, p. seekhao, t. leelasawassuk, k. tanta-ngai, k. tungpimolrut, "design and development of an open architecture cnc controller for milling machine retrofitting," in proceeding of icros-sice international joint conference 2009, fukuoka international congress center, japan, august 18-21, 2009, pp. 5629-5632. [9] dohyun kim, doyoung jeon, "fuzzy-logic control of cutting forces in cnc milling processes using motor currents as indirect force sensors," precision engineering, volume 35, issue 1, pp. 143–152, januari 2011. [10] g. rzevsski, "on conceptual design of intelligent mechatronics system," mechatronics, volume 13, issue 10, pp. 1029-1044, desember 2003. [11] a. coronato, g. de pietro, l. gallo, "an agent based platform for task distribution in virtual environments," journal of systems architecture, volume 54, issue 9, pp. 877– 882, september 2008. [12] x. desforges, b. archimede, "multi-agent framework based on smart sensors/actuators for machine tools control and monitoring, 19," engineering applications of artificial intelligence, volume 19, issue 6, pp. 641– 655, september 2006. [13] luis morales-velazquez, rene de jesus romero-troncoso, roque alfredo osorniorios, gilberto herrera-ruiz, eduardo cabalyepez, "open-architecture system based on a reconfigurable hardware–software multiagent platform for cnc machines," journal of systems architecture, volume 56, issue 9, pp. 407–418, september 2010. [14] gsk cnc. (2007) cnc machine and cnc equipment, cnc milling controller gsk 983m. [online]. available: http://gskcnc.com/cnc_controller.php [dikutip: 25 oktober 2011] [15] damen cnc. (2009) usbcnc cpu v3 software+hardware interface. [online]. available: http://www.damencnc.com/damencnc.php?d ir=cpt&idcomp=195&langid=en [dikutip: 25 oktober 2011] [16] li zhang, ruqiang yan, robert x. gao, and kang b. lee, "open architecture software design for online spindle health monitoring," in proceeding of instrumentation and measurement technology conference imtc 2007, warsaw, poland, 1-3 may, 2007, pp. 1-6. [17] fanuc ltd japan, fanuc operator’s manual., 1988. [18] tao liu, yongzhang wang and hongya fu, "the open architecture cnc system hitcnc based on step-nc," in proceeding of 6th world congress on intelligent control and automation, dalian, china, june 21 23, 2006, pp. 7983-7987. [19] m. minhat, v. vyatkin, x. xu, s. wong, z. al-bayaa, "a novel open cnc architecture based on step-nc data model and iec 61499 function blocks," robotics and computer-integrated manufacturing, volume 25, issue 3, pp. 560–569, june 2009. [20] lawrence h. vanvlack, ilmu dan teknologi bahan, ed. surabaya, indonesia: elangga, 1990. [21] roberto augusto gómez loenzo, pedro daniel alaniz lumbreras, rené de jesús romero troncoso, gilberto herrera ruiz, "an object-oriented architecture for sensorless cutting force feedback for cnc milling process monitoring and control," advances in engineering software, volume 41 , issue 5, pp. 754–761, mei 2010. kata pengantar dewan editor daftar isi pemasangan solar collector instrumentasi standar kondisi pengujian prosedur pengujian analisis hasil pengujian references hough circle offers easy and practical way of detecting drill holes. however this algorithm delivers poor performance as it is applied in this case. the algorithm is based on sobel operation, which is rather sensitive to noises. setting the threshold ... this algorithm performs much better compared to the hough circle. the holes in the glare area can also be really preserved due to the tophat algorithm. though there are some problems around the glared and shadowed area, the result is still acceptable.... / table 1. routing coordinate extraction performance. table 2. mev j. mechatron. electr. power veh. technol 07 (2016) 87-92 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.87-92. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine bambang wahono a, b,*, arifin nur b, achmad praptijanto b, widodo budi santoso b, suherman b, zong lu c a graduate school of mechanical engineering, university of ulsan ulsan, san 29, mugeo2-dong, nam-gu, ulsan, 44610, republic of korea b research centre for electrical power and mechatronics, indonesian institute of sciences, komplek lipi, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia c brother industries, ltd. 15-1 naeshiro-cho, mizuho-ku, nagoya, 467-8561, japan received 11 october 2016; received in revised form 7 november 2016; accepted 8 november 2016 published online 23 december 2016 abstract range extender engine is one of the main components of the range-extended electric vehicle (reev) and together with a generator to extend the mileage of the electric vehicle. the main component of reev is an electric motor, battery, and generator set that consist of generator and engine. in this study, we compared two models of reev performance with two different types of the engine by simulation. single cylinder 499 cc gasoline engine and single cylinder 667 cc diesel engine are chosen as the object of this research especially relating to the utilization of the fuel consumption and co2 emissions when fitted to an electric vehicle. the simulation was conducted by using avl cruise software and performed by entering the data, both experiment and simulation data, on all the main components of reev. this simulation was performed in japan 08 driving cycle. based on the simulation, fuel consumption is reduced up to 35.59% for reev with single cylinder diesel engine 667 cc compared to reev with single cylinder gasoline engine 499 cc. the reduction of co2 emissions from reev with single cylinder 499 cc gasoline engine compared to reev with single cylinder 667 cc diesel engine up to 30.47%. keywords: range extender engine; performance; diesel; gasoline; avl cruise. i. introduction energy efficiency and emission are the most important aspects in the development of vehicle technology. in many types of research related to the energy and vehicle, many researchers give more attention to these aspects. some countries have done a large number of studies with these focuses such as china [1, 2], us [3, 4], portugal [5], uk [6], india [7] and etc. they do this type of research because of its great effects. the vehicle emission affects the air quality, health, and climate in the world [8]. on the other hand, based on the who research, the emission of the vehicle is responsible for the death of people accounted up to seven million per year [9]. with respect to energy efficiency, transportation has become the largest sector which needs fuel approximately 90% of the total energy consumption needed [10]. on the other hand, oil resources have been rapidly running out and expected to be completely depleted within 50 years [11]. based on this situation, researchers in the world are required to conduct research that is able to reduce fuel consumption and decrease vehicle emissions. one of the latest technologies that have been developed is the electric car. but an electric car has some disadvantages such as limited mileage and expensive batteries. to solve this problem, a range extender technology has been developed. the range extender is a technology that uses a small engine installed in a series configuration with a generator in the electric car. the car is called the range-extended electric vehicle (reev). although this technology still has emission, but the number is * corresponding author.tel: +6222-2503055 e-mail: bambangwahono80@yahoo.co.id, bamb053@lipi.go.id http://dx.doi.org/10.14203/j.mev.2016.v7.87-92 b. wahono et al. / j. mechatron. electr. power veh. technol 07 (2016) 87-92 88 relatively low because it works only when needed to charge the batteries. the main drive of reev is the battery. the range extender is mounted in a car to increase the mileage of electric cars. similar researches have been conducted by researchers from several vehicles companies and research institutes such as avl that develop a range extender with 2-cylinder engine with a power of 15 kw. this engine has a compact size but its emission is still high, and furthermore, the maintenance cost is also high [12]. the other researcher also developed a range extender from the fuel cell. the advantages of this range extender engine are able to produce lower noise, vibration, and emissions. the disadvantage of this range extender engine is high production cost [13]. this paper is focused on the investigation of range extender engine with 1 cylinder gasoline engine 499 cc and 1 cylinder diesel engine 667 cc, especially relating to the utilization of the fuel consumption and co2 emissions by using a simulation system of the vehicle. the goal of this research is to understand the comparison of the performance and co2 emission of the range extender engine by two types of engine on minimal engine capacity. this study is the continuation of the previous research that has been published previously [14]. in the previous research, some of the gasoline engines were compared to get the best performance and emission of the range extender engine. based on this research, the performance and co2 emission of the engine will be well understood and the result can be used as a reference to build the real engine and optimization of the energy balance that can be applied in an electric vehicle especially in the electric vehicle developed in lipi. ii. simulation of rangeextended electric vehicle in this study, range-extended electric vehicle (reev) was chosen as the model. the components were all the same, it was only the engine that makes the difference in the two models. in this simulation, two engine models are used, i.e. the single cylinder 499 cc gasoline engine was compared against the single cylinder 667 cc diesel engine. the vehicle system simulation was performed by avl cruise and japan 08 driving cycle was chosen as road condition characteristic. the details of electric vehicle size and specification of motor generator component are shown in table 1 and table 2. the engine parameters used to investigate as the object on reev modelling by avl cruise are shown on table 3. the basic configuration of range extended electric vehicle (reev) is shown in figure 1. range extended electric vehicle have table 1. basic parameter of electric vehicle parameter range extended electric vehicle fuel diesel, gasoline frontal area 1.97 (m2) dynamic rolling radius 301 (mm) final drive transmission ratio 4.266 battery model wb-lyp200aha table 2. motor generator specification type gkn af-130 max speed 8,000 rpm nominal torque 170 nm peak torque @20 s 400 nm nominal output power 80 kw peak output power @20 s 150 kw peak efficiency 95.10% dimension (l x d) 110 x 300 mm weight 30.5 kg table 3. engine specification type gasoline 499 cc diesel 667 cc * model hatz 1d81 cylinder/valve 1/4 dohc 1/2 ohc bore x stroke (mm) 86 x 86 100 x 80 max torque (nm/rpm) 27.3/3,500 32.6/2500 max power (kw/rpm) 10.54/4,000 10.21/3000 maximum speed (rpm) 6,000 3,600 stroke 4 4 inertia moment 0.35 0.51 fuel system efi di fuel gasoline diesel heating value (kj/kg) 43,500 43,100 *based on experiment figure 1. reev drive train configuration b. wahono et al. / j. mechatron. electr. power veh. technol 07 (2016) 87-92 89 some main components i.e. range extender that consists engine and generator in a series configuration, battery, and electric motor. in this study, we used two models of engine to investigate the performance of reev i.e. a single cylinder 499 cc gasoline engine with maximum power 10.54 kw and a single cylinder 667 cc direct injection diesel engine with maximum power 10.21 kw. the model of the generator is af 130 synchronous-axial flux with a maximum speed of 8,000 rpm and nominal output power is 80 kw [15]. the series configuration was chosen to minimize engine power capacity when the battery capacity drops to 30% of its capacity, the combustion engine starts the on mode to supply the battery by rotating the af 130 generator. on this phase, the hpevs ac 20 electric motor is powered by the battery that is charged by the af 130 generator. the generator itself, in turn, was pulled by the combustion engine that is managed by the battery management system (bms). the model of the battery was lifeypo4 type lithiumion batteries with 200 ah/3.2 v, arranged in a series configuration consist of 30 unit of batteries [16]. the model of the electric motor is hpevs ac-20 96 v 650 a, ac induction motor with a curtis controller [17]. the weight values of two models vehicle are given in table 4. in this research, the model of reev was built in the avl cruise vehicle simulation. the model of reev is shown in figure 2. all data from the main components of reev and others data for the vehicle were input to the avl cruise. in this study, the japan 08 driving cycle was used to represent the driving condition congested with city traffic, idling periods, frequently alternating acceleration and deceleration. japan 08 driving cycle was chosen due to stop and go road condition. this japan 08 driving cycle has been frequently used for emission measurement and fuel economy determination, both of gasoline or diesel vehicles. the mode of this driving cycle is shown in figure 3. in this research, two types of engine were modelled to determine the performance of the best model of range-extended electric vehicle. maps of the engine performance came from the data that were collected through the experiment at various speeds in an internal combustion engine laboratory at lipi and the simulation by table 4. weight for each component parameter reev with 1 cylinder gasoline engine 499 cc reev with 1 cylinder diesel engine 667 cc curb weight (kg) 873.0 873.0 engine weight (kg) 53.0 105.0 electric machine weight (kg) 27.2 27.2 battery weight (kg) 237.0 237.0 generator weight (kg) 30.5 30.5 load (kg) 263.0 263.0 gross weight 1,483.7 1,535.7 figure 2. reev model in avl cruise figure 3. japan 08 driving cycle b. wahono et al. / j. mechatron. electr. power veh. technol 07 (2016) 87-92 90 using avl boost to get the maximum torque, brake specific fuel consumption (bsfc) maps and motoring torque at full or partial throttle in each engine. table 3 shows the specifications of each internal combustion engine. the full load torque output of each internal combustion engine was input into avl cruise, as shown in figure 4. iii. result and discussion in this simulation, it was assumed that the energy stored in the battery when the vehicle started to run was 90% of soc as an initial charge and the vehicle would not run until the battery capacity was down to 30%. range extender engine was used as one of the main components of reev with the engine speed of 3000 rpm both in diesel engine and gasoline engine. the term of the range extender is used in order to describe that the engine is used to extend the operational range of the electric vehicle until the ev find the nearest ev charging point. the engine used as the range extender will be off as long as there is enough energy in the batteries and will be activated when the total batteries capacity which is called as the state of charge (soc) drops to 35%. the range extender system will still be active until the batteries are charged up to 48% soc. the simulation results based on japan 08 driving cycle of the reev vehicle conducted with road range, fuel consumption and emissions of the two systems are shown in table 5. since the reev is configured on a series system that means the engine is only propulsing the generator to generate the electricity for charging the batteries, then the batteries supply the energy to the electric motor, therefore it can be concluded that the engine should have enough energy to rotate the generator on it maximum rotation. the engine will only work when the soc value dropped to 35%. on figure 5, it can be seen that the single cylinder 499 gasoline engine is running harder to rotate the generator for charging the batteries. as the effect, the gasoline engine is always on and automatically increases the fuel consumption. the fuel consumption of reev with a single cylinder gasoline engine 499 cc is 3.54 l/100 km, while the reev with single cylinder diesel engine 667 cc is 2.28 l/100 km. this is because the reev with a single cylinder diesel engine 667 cc have enough power to propulse the generator which charges the batteries that is controlled by battery management system (bms). the diesel engine is working only when needed while the gasoline engine is running continuously to charge the batteries. after the engine is activated, the generator works and transmits the energy to the batteries. an reev with a single cylinder diesel engine 667 cc is fast to increase the battery capacity up to 48%, so automatically the vehicle is powered by the batteries. the mode is repeated. this is different if compared with the reev with a single cylinder gasoline engine 499 cc. in this condition, the reev with a single cylinder gasoline engine 499 cc was unable to increase the soc, due to lack of power to rotate the generator. although the maximum power output of 499 cc gasoline engine is higher than 677 cc diesel engine but by modelling it shows that the continuous output power of the reev with a single cylinder diesel engine 667 cc is higher than reev with single cylinder gasoline engine 499 cc. the continuous power output of the engine single cylinder diesel 667 cc that can be transmitted to rotate the generator up to 10.04 kw while the continuous power output of the range extender engine with a single cylinder gasoline engine 499 cc is 8.22 kw. this happens due to the lower torque generated by the gasoline (27.3 nm/3,500 rpm) engine, while the torque of the diesel engine is 32.5 nm/3,000 rpm (max 32.6 nm/2,500 rpm). as the effect, the range extender engine with a single cylinder diesel 667 cc is easier to increase the soc value of the batteries. this condition has a relation with the co2 emission of range extender engine. the difference of the fuel consumption of each vehicle model also affects the co2 emissions produced. it can be seen in table 3 that co2 figure 4. full load torque output of engine table 5. performance of two vehicle model in japan 08 driving cycle parameter reev with 1 cylinder gasoline engine 499 cc reev with 1 cylinder diesel engine 667 cc model hatz 1d81 fuel consumption of engine (l/100 km) 3.54 2.28 co2 (g/km) 86.11 59.88 b. wahono et al. / j. mechatron. electr. power veh. technol 07 (2016) 87-92 91 emission of the re with a single cylinder diesel 667 cc is lower than the re with a single cylinder gasoline 499 cc. in addition, the increasing of co2 emissions of the re with a single cylinder gasoline 499 cc is also caused by the prolonged use of a range extender engine when the batteries capacity is down to its limit. to increase the value of soc from 35% to 48% of batteries capacity requires operation up to 30 minutes for a single cylinder diesel engine, while the re with a single cylinder gasoline 499 cc operates continuously until the fuel is depleted. as the effect, co2 emission of the re with a single cylinder gasoline 499 cc is 30.47% higher than the re with a single cylinder diesel 667 cc. the operating condition of each range extender engine is shown in figure 5. figure 6 and figure 7 show the characteristics of the range extender engine operation mode related to battery soc curve versus operational range (distance). in addition, these two figures also show the engine output power versus operational range (distance). for the re with the diesel engine that is shown in figure 6, the generator set was operated temporarily to charge the battery, when the battery capacity was enough to power the electric motor then the generator set will be shut off. in addition for figure 6, it can be observed that the minimum power that should be supplied to the vehicle to follow the road characteristic based on the japan 08 driving cycle is about 10.04 kw. while figure 7 shows the minimum power that should be supplied to the vehicle to follow the operational characteristic based on the japan 08 driving cycle is about 8.22 kw. it is shown by the flatted dash line when the soc falls to 35%. when this event occurred, it means the operational range of the electric vehicle becomes unlimited depend on diesel or gasoline fuels. this condition induces the generator set working as a range extender on the electric vehicle as known as reev. since the generator works in optimum conditions, the advantages of the range extender engine on the electric vehicle can be achieved. based on this simulation, the reev model with the re single cylinder diesel engine 667 cc gave the best performance on fuel consumption and co2 emission for range extender application. iv. conclusion the simulation model of range-extended electric vehicle (reev) was built using avl cruise software piloting a japan 08 driving cycle. the diesel engine is better than gasoline engine if applied as a component of the range extender if the optimum rotation of generator is relatively low. the major factor that influences the engine ability to increase the battery capacity is torque rather than power at same optimum rotation for the generator. based on the weight of the engine simulation and inertia moment of the engine, we found that there is not much effect the operational range of the reev. based on the simulation, the range-extender electric vehicle with a single cylinder diesel 667 cc appeared as the best choice when running on japan 08 driving cycles. the performance characteristics of range extended electric vehicles can be predicted for further system development. a comprehensive study for building a better understanding of range extender systems for an electric vehicle is necessary to understand the compatibility of each component and characteristic of the rangeextender electric vehicle. figure 5. soc of two vehicle model simulated over japan 08 driving cycle figure 6. soc, engine speed, and engine power in reev 1 cylinder 667 cc simulated over japan 08 driving cycle figure 7. soc, engine speed, and engine power in reev 1 cylinder 499 cc simulated over the japan 08 driving cycle b. wahono et al. / j. mechatron. electr. power veh. technol 07 (2016) 87-92 92 acknowledgement this research is supported by competitive research grant 2015, provided by indonesian institute of sciences. the author would like to thank all member of internal combustion engine laboratory, indonesian institute of sciences for their assistance in collecting data in internal combustion engine experiment. references [1] y. wu et al., "energy consumption and co2 emission impacts of vehicle electrification in three developed regions of china," energy policy, vol. 48, pp. 537550, 2012. [2] x. ou et al., "life-cycle analysis on energy consumption and ghg emission intensities of alternative vehicle fuels in china," applied energy, vol. 90, pp. 218224, 2012. [3] a. y. saber and g. k. venayagamoorthy, "plug-in vehicles and renewable energy sources for cost and emission reductions," ieee transactions on industrial electronics, vol. 58, pp. 1229-1238, 2011. [4] f. an et al., "global overview on fuel efficiency and motor vehicle emission standards: policy options and perspectives for international cooperation," united nations background paper, 2011. [5] d. l. greene and s. plotkin, "reducing greenhouse gas emission from us transportation," arlington: pew center on global climate change, 2011. [6] e. demir et al., "a comparative analysis of several vehicle emission models for road freight transportation, "transportation research part d: transport and environment". vol. 16, pp. 347-357, 2011. [7] k. subramanian et al., "comparative evaluation of emission and fuel economy of an automotive spark ignition vehicle fuelled with methane enriched biogas and cng using chassis dynamometer," applied energy, vol. 105, pp. 17-29, 2013. [8] d. shindell et al., "climate, health, agricultural and economic impacts of tighter vehicle-emission standards," nature climate change, vol. 1, pp. 59-66, 2011. [9] who. (2014, may 13, 2015). global health observatory data reporting 2014. available: http://www.who.int/mediacentre/news/rele ases/2014/air-pollution/en/ [10] s. sorrell et al., "global oil depletion: a review of the evidence," energy policy, vol. 38, pp. 5290-5295, 2010. [11] c. i. agency, the world fact book, pp. 1553–8133, 2009. [12] avl. (2015, may, 21). avl range extender specifications. available: www.avl.com/rangeextender. [13] p. sharer and a. rousseau, "fuel cells as range extenders for battery electric vehicles," presented at the 2013 doe hydrogen program and vehicle technologies annual merit review, 2013. [14] b. wahono et al, "a comparison study of range-extended engines for electric vehicle based on vehicle simulator," journal of mechanical engineering and sciences (jmes), volume 10, issue 1, pp. 18031816, june 2016. [15] (2015, may 29). af-130 generator evo electric. available: http://www.evoelectric.com/inc/files/af130%20spec%20sheet%20v1.1.pdf. [16] t. s. winston. (2015, may 31). wblyp200aha. available: http://en.winstonbattery.com/index.php/products/powerbattery/item/wb-lyp200ahab. [17] hpevs. (2014, august 28). ac-20 torque & horsepower, high performance electric vehicle systems. available: http://www.hpevs.com/power-graphs-ac20.htm. i. introduction simulation of range-extended electric vehicle iii. result and discussion iv. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. ir. suhono h supangkat, m.eng, cgeit. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. dr. ir. zainal abidin mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. iman k reksowardojo mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135 indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810, indonesia ir. edi leksono, m.eng, ph.d. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. arjon turnip technical management unit for instrumentation development lipi komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2ndfl, bandung 40135, indonesia dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. sunit hendrana research center for physics lipi komp lipi jl sangkuriang, blg 60, 2nd fl, bandung 40135, indonesia dr. ary setijadi prihatmanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. adi soeprijanto, mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. ir. feri yusivar, m.eng department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr. agus purwadi school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, st., mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with semi colon and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev j. mechatron. electr. power veh. technol 07 (2016) 27-34 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.27-34. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. nonlinear tracking control of a 3-d overhead crane with friction and payload compensations anh-huy vo a, quoc-toan truong a, ha-quang-thinh ngo a,b, quoc-chi nguyen a,b,* adepartment of mechatronics, ho chi minh city university of technology 268 ly thuong kiet st., dist. 10, 703500, ho chi minh city, vietnam bcontrol and automation laboratory, ho chi minh city university of technology 268 ly thuong kiet st., dist. 10, 703500, ho chi minh city, vietnam received 29 february 2015; received in revised form 02 may 2015; accepted 02 may 2015 published online 29 july 2016 abstract in this paper, a nonlinear adaptive control of a 3d overhead crane is investigated. a dynamic model of the overhead crane was developed, where the crane system is assumed as a lumped mass model. under the mutual effects of the sway motions of the payload and the hoisting motion, the nonlinear behavior of the crane system is considered. a nonlinear control model-based scheme was designed to achieve the three objectives: (i) drive the crane system to the desired positions, (ii) suppresses the vibrations of the payload, and (iii) velocity tracking of hoisting motion. the nonlinear control scheme employs adaptation laws that estimate unknown system parameters, friction forces, and the mass of the payload. the estimated values were used to compute control forces applied to the trolley of the crane. the asymptotic stability of the crane system is investigated by using the lyapunov method. the effectiveness of the proposed control scheme is verified by numerical simulation results. keywords: 3-d overhead crane; nonlinear adaptive control; lyapunov method; euler-lagrange equation; sway control. i. introduction overhead crane systems are widely used to move goods from one place to another in factories and harbors. a crane is naturally an underactuated mechanical system, in which the number of actuators is less than degrees of freedom (dof) of the system. for an overhead crane, the degree of freedom is five (i.e., trolley and girder positions, rope length, and two sway angles) but the number of actuators is three (i.e., trolley, girder, and hoisting-motors). to improve the efficiency of an overhead crane, the trolley and girder should travel as fast as possible. however, fast trolley and (or) girder motions resulted in the large sway motions of the payload. therefore, the fast motions of the trolley and (or) girders do not guarantee the improvement of the overhead crane efficiency because it may take a long time to suppress the sway motions of the payload. moreover, for safety, the sway motions should be kept as small as possible during crane operation. therefore, development of a control algorithm that allows fast trolley and girder motions together with quick sway suppression is desirable for crane systems. a number of crane control algorithms based on 2d models [1-8] have been developed. it should be noted that 2d models do not represent all the cases of overhead crane operation in practice. 3d models [9-20] have been proposed to describe the crane more precisely, but they are more complex than 2d models. it should be noted that the complexity of the 3-d models yields difficulties in control design. most researchers focused on 3d models of overhead cranes with four dofs [914,17-18, 20] (i.e., trolley and girder, and two sway motions), where hoisting motion was not considered. it should be noted that the hoisting motion cannot be neglected in practice because the variation of the rope length significantly affects the sway dynamics. however, only few researches consider crane systems with five dofs that include the hoisting motion [15-16] due to the * corresponding author. tel: +84-8-38688611 e-mail: nqchi@hcmut.edu.vn http://dx.doi.org/10.14203/j.mev.2016.v7.27-34 a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 28 complexity of the model and consequently control design. most of the researches about overhead crane in recent years are developed based on the eulerlagrange equation. some of them use lyapunov theory to design adaptive control [1-4,10-13, 16, 17] which estimates unknown parameters. the others use linearization technique in order to simplify the mathematical model and design of linear controllers such as sliding mode control [2, 7, 8] and fuzzy control [12, 17]. in practice, the crane systems are usually operated under the unknown parameters such as the mass of payload and friction/damping force. to solve this problem, adaptive control [1-4,10-13, 16, 17], fuzzy control [12, 17], and sliding mode control [2, 7, 8] have been developed. since adaptive control schemes are able to estimate unknown parameters that is used in control laws, lyapunov energy-based control can be employed to establish the control design. the use of the lyapunov control energy-based control facilitates the development of control algorithms based on nonlinear models, which represent nonlinear system precisely. the work [7] proposed an adaptive sliding mode control using estimated unknown payload and damping coefficient, where the variation of the rope length is considered. however, the control adaptive scheme is based on a 2d model. in this paper, a 3d overhead crane model with five dofs (motions of trolley and girder, hoisting, two sway angles) is derived using euler-lagrange equation. a nonlinear adaptive control that estimates the coefficients of friction and the mass of payload is proposed. the stability of the proposed control system is investigated using lyapunov method. the effectiveness of the proposed control law is illustrated by experiment results. ii. dynamics of a 3d overhead crane figure 1 shows an overhead crane system with the sway motions of the payload in the world coordinate system oxyz. in the derivation of the dynamic model of the crane, the following assumptions are made: (i) the payload and the trolley are connected by a massless-rigid link. also, the mechanical frame of the crane is considered as a rigid body. (ii) the mass of trolley is unknown. (iii) the friction forces fcx and fcy cannot be measured, where the viscous friction coefficients cx and cy are unknown. as shown in figure 1, the girder, the trolley, and the payload position vectors are given as follows 0 0 , 0 , sin cos sin cos cos , r c p r x r x y r x l y l l (1) where x and y are the trolley position in x and y directions, respectively. let 5( )q t r be the generalized coordinate vector defined as follows. t ( ) ( ) ( ) ( ) ( ) ( )q t x t y t l t t t (2) the forces applied to the system are given by. [( ) ( ) 0 0] x cx y cy l f f f f f f (3) the friction forces in the x and y directions respective are given as follows. ( ) ( ), ( ) ( ) cx x cy y f t c x t f t c y t (4) where cx and cy are the viscous friction coefficients in x and y directions, respectively. the total kinetic energy k and the potential energy p of the crane system are given as , , trolley rail payload payload k k k k p p (5) where 1 2 trolley c c c k m r r  (6) 1 , 2 rail r r r k m r r  (7) 1 , 2 payload p p p k m r r  (8) (1 cos cos ). payload p p m gl (9)   x y z o f l f ( )l t cy f cx f c m r m p m  figure 1. the overhead crane system a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 29 using the euler-lagrange equation [21], the equations of motion are derived as follows ( 1, 2,3, 4,5) i i i d l l t i dt q q (10) with l = k-p. the dynamic equations (10) can be rewritten as ( ) ( , ) ( ) , m m q q c q q q g q u (11) where 5 5 ( )m q r is inertia matrix of the crane system and 5 5 ( ) m c q r represent the centripetal coriolis, and 5 ( )g q r is the gravity term. based on the structure of ( )m q and ( , ) m c q q given by eq. (11), it should be noted that the following skew-symmetric relationship is satisfied. 51 ( ) ( , ) 0, , 2 t m m q c q q r (12) where ( )m q can be upper and lower bounded by the following inequality. 2 2 5 1 2 ( ) , t n m q n r (13) where 1 2 and n n r are positive bounded constants. iii. control design in this section, a control law is proposed to drive the crane to the desired position and to suppress the sway angles simultaneously. for convenience, a new generalized coordinate vector is defined as follows t , m a q q q (14) where ( ) ( ) ( ) t m q x t y t l t , ( ) ( ) t a q t t . the equations of motion of the overhead crane (11) can be rewritten as follow. (15) to achieve the control objective, with the given desired signals d q , d q , and d q (which are assumed to be bounded), the control law mf u is designed to guarantee the asymptotical convergence of q to d q . the error signals are defined as (16) where t = m m dm x y l e q q e e e tt a a da d d e q q e e where are defined trajectories of , respectively. are defined as follows (17) where 0 0 0 0 0 , 0 0 m a k k k 1 2 3 0 0 0 0 , 0 0 k k k k 4 5 0 0 k k k and are positive definite matrices. a new variable s are defined as follows (18). then, using eq. (11), the dynamics in terms of the signals and can be derived as (19) where the fictitious torques and are defined as follows ( ) , ( ). m mm rm ma ra mm rm ma ra m mcf a am rm aa ra am rm aa ra a m q m q c q c q g q u m q m q c q c q g q (20) the signals and can be expressed as in term of a known matrix and and unknown parameter vectors, and . 11 13 22 23 32 0 0 0 0 0 0 0 0 , c r p c pm m pm m m xm y m m m m m m mx my c c τ (21) ( ) ( ) . 0 0 mm ma m mm ma m m am aa a am aa a a mf mcf m m q c c q g q m m q c c q g q u u , t t t d m a e q q e e , , , , d d d d d x y l , , , , x y l r q , rx ry dm m m rm rlr d da a a ra r r q q q k e q qq q ke q k e q q q m k a k m rm m r a ra a q q s s q q q q s m s a s , mm ma m mm ma m m mf am aa a am aa a a m m s c c s u m m s c c s m a m a m a m a a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 30 where (22) where as a majority of the adaptive controller, the following signal is defined. (23) where is a positive constant and (24) from eq. (24), it is concluded that is positive. define a positive function . it can be shown that 2 2 1 ˆ( ) ( ) ( ) 0 m t t a a a a av a m h s h t s s k s h t s h t (25) it is assumed that there exists a measure zero set of time sequences such that (i.e., ). the following control law is proposed. (26) where where are the estimates of and , respectively. the adaptation laws are given as. (27) then the error dynamics can be obtained as. (28) which can be rewritten as follows. (29) where since are constant, we obtain. (30) theorem: consider the system (11) under the parameters systems unknown. the proposed control law (26) employing the adaption laws (27) guarantees the asymptotic stability of the systems, i.e., , , and as . proof: lyapunov function candidate can be defined as. (31) 11 13 sin cos cos cos sin sin (cos cos sin sin ) cos cos sin cos cos sin sin sin cos sin sin cos m rx m rl r r rl r r q q l q l q q l l l q l l l q 22 23 32 2 sin cos cos cos sin sin cos sin + cos cos cos . m ry m rl r rl r m rx ry rl r r q q l q q l l q q q q l q l q g g 11 22 0 , 0 pa a a a pa m m 2 2 2 11 2 2 2 2 22 2 cos cos cos cos cos sin cos + cos sin sin cos sin sin cos cos sin a rx ry rl r r a rx ry r rl r r l q l q l q l l l q l q gl l q l q l q l q l q llq g cos sin .l 2 2 2 11 2 2 2 2 22 2 cos cos cos cos cos sin cos + cos sin sin cos sin sin cos cos sin a rx ry rl r r a rx ry r rl r r l q l q l q l l l q l q gl l q l q l q l q l q llq g cos sin .l 2( ( ) ( )), ( ) 0 2 ( ) ( ) 0 ( ) 0 , ( ) 0 ( ) 0 x x x x x x x x x x x z a t b t z t z b t z t b t z t b t x 2 2 2 ˆ( ) ˆ( ) m t t x a a a a av a m t t x a a a a av a m s a t s s k s s b t s s k s s ( ) x z t ( ) x h t z 1i i t ( ) 0 i z t ( ) 0, 1, 2, 3,..., i h t i ˆ mf m m v mv m u k s 2 ( 1) ˆt tm v a a a a av a m h s s s k s s ˆ ˆ m a and m a ˆ ˆ t m m m m t a a a a s s 0 0 , mm ma m mm ma m mv m am aa a am aa a av a m m v a a av a m m s c c s k s m m s c c s k s k s ( ) ( , ) m m v m a a av a m q s c q q s ks k s ˆ ˆ m mm a a a ˆ ˆ m a and ˆ ˆ . ˆ ˆ m m m m a a a a 0s 0e 0e t 1 11 1 1 1 ( ) ( ) 2 2 2 2 t t t m m m a a a x v t s m q s z a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 31 from eqs. (23)-(24), positive-definite can be concluded. taking the time derivative of yields. 1 1 ( )= . t t t t t m m m m m a a a a a v t s ks s s (32) by substituting (27) into (32), the following inequality is obtained. t ( ) 0v t s ks (33) from eq. (23), it is concluded that is continuous for all . since is a continuous function of , is continuous at time , i.e., . from eq. (33), and then it is concluded that is nonincreasing at time , which implies . therefore, from eq. (22) , and using definitions of , is obtained. moreover, it is clear that ∫ �̇�𝑑𝑡 = 𝑉() − v(0) <   0 , or equivalent. therefore by invoking the barbalat’s lemma, we obtain that asymptotically as , therefore, implies as . iv. experiment results the experiments were carried out with the testbed, as shown in figure 2. the payload hangs at the end of the rope whose top end is hinged by the pulley mounted on the trolley. three ac servo motors (mitsubishi mr-j2s-40) make the three motions of the crane system: the trolley, the girder, and the hoisting. the three motors are controlled via current inputs provided by a power interface. the five encoders are employed to measure the five variables, i.e. the displacements of the trolley and the gantry, the rope length, and the two sway angles of the payload, where three encoders are available in the three ac servo motors. the pulse signals of the five encoders are converted to 16-bit digital signals by the power interface. the reference signals for the three ac servo motors are sent from a pc to the power interface through a pci board (smc-4df-pci provided by contec company), which also receives the 16bit digital signals of the five encoders. the control program runs in windows 7 environment. to illustrate the control performance, we perform the experiments of the proposed nonlinear adaptive controller of (30) employing the adaptation laws (27) in a testbed (as shown in figure 2) with the following parameters: 2 5 kg, 5 kg, 0.5 kg, 9.81 m/s c r p m m m g the initial state of the system is chosen as: (0) 0, (0) 0, y(0) 0, (0) 0, (0) 1 m, (0) 0, (0) 0, (0) 0, (0) 0, (0) 0. x x y l l ( )v t ( )v t ( )h t i t ( )v t ( )h t ( )v t i t ( ) ( ) i i v t v t ( ) 0 i v t ( ) 0 i v t ( )v t i t ,s h l , , m a e l , m a s l 0s t and 0e e t ac servo of x direction ac servo of y direction ac servo of hoisting motion controller driver ac servo figure 2. experimental system a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 32 the trolley moves to the desired position selected as follows: the control gains of the control law (26) are turned until the best performance is achieved, which yields the following control gains. figures 3, 4 and 5 plots demonstrate that trolley reach 0.8 m d x at t = 12.3s and 0.8 m d y at t = 12.3s, the rope will drop payload down from initial height (0) 0.8 ml to zero position after duration t = 12.3s. during trolley is moving, the maximum vibration amplitudes of the sway angles and are demonstrated in figure 6 and 7. after 14 seconds, the vibration almost eliminated figures 8 and 9 are the parameters estimation results. the estimated values converge to constant although it may not get the true values. as shown in figures 8 and 9, the values may not get the true values. however, getting true values of the parameters was not the purpose of this paper. 0.8 , 0, 0.8 , 0, 0 , 0. d d d d d d x m x y m y l m l       17 0 0 0.1 0 0 15 0 , , 0 0.1 0 0 15 1.2 0 0 0.6 0 0 1.5 0 , , 0 0.6 0 0 3.5 m a vm va k k k k                               0.02, 0.2, 0.03 m a      0 max ( ) 4t 0 max ( ) 3.3t figure 5. rope length figure 3. position of the trolley in x-direction figure 6. sway angle ( )t figure 4. position of the trolley in y-direction figure 7. sway angle ( )t a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 33 v. conclusion in this paper, a 5-dof dynamic model of the 3d overhead crane was developed under the effects of unknown friction force and unknown payload. a nonlinear adaptive controller was proposed for the overhead crane to drive it to its desired point and to suppress the swing of payload. under the proposed controller, asymptotic stability of the overhead crane system is proved by using lyapunov method. experiment and simulation results illustrate the effectiveness of the proposed controller. acknowledgement this research is funded by vietnam national foundation for science and technology development (nafosted) under grant number 107.04-2012.37 and by vietnam national university ho chi minh city (vnu-hcm) under grant number c2013-20-01. references [1] d. liu et al., “adaptive sliding mode fuzzy control for a 2d overhead crane,” mechatronics, vol. 15, no. 5, pp. 505–522, 2005. [2] h. h. lee et al., “a sliding mode anti-swing trajectory control for overhead cranes with high speed load hoisting,” journal of dynamic systems, measurement and control, vol. 128, no. 4, pp. 842–845, 2006. [3] c. y. chang, “adaptive fuzzy controller of the overhead cranes with nonlinear disturbance,” ieee transactions on industrial informatics, vol. 3, no. 2, pp. 164– 172, 2007. [4] m. s. park et al., “anti-sway tracking control of overhead cranes with system uncertainty and actuator nonlinearity using an adaptive fuzzy sliding mode control,” ieee transactions on industrial electronics, vol. 55, no. 11, pp. 3972–3984, 2008. [5] s. w. su et al., j. zhu, d. b. lowe, p. b. mclean, s. huang, n. nguyen, r. s. nicholson and k. wing, “model predictive control of gantry crane with input nonlinearity compensation,” in world academy of science, engineering and technology, 2009. [6] y. fang et al., “a motion planning based adaptive control method for an under actuated crane system,” ieee transactions on control systems technology, vol. 20, no. 1, pp. 241–248, 2011. [7] l. a. tuan et al., “adaptive sliding mode control of overhead cranes with varying cable length,” journal of mechanical science and technology, vol. 27, no. 3, pp. 885–893, 2013. [8] d. qian and j. yi, “design of combining sliding mode controller for overhead crane systems,” international journal of control and automation, vol. 6, no. 1, 2013. [9] h. chen et al., “dynamical modeling and nonlinear control of a 3d crane,” in proc. of the international conference on control and automation, 2005, pp. 1085-1090. [10] j. h. yang and k. s. yang, “adaptive control for 3-d overhead crane systems,” in proc. of the american control conference, 2006. [11] k. s. lee and h. c. cho, “adaptive control and stability analysis of nonlinear crane systems with perturbation,” journal of mechanical science and technology, vol. 22, no. 6, pp. 1091–1098, 2008. [12] c. y. chang and k. h. chiang, “fuzzy projection control law and its application to the overhead crane,” mechatronics, vol. 18, no. 10, pp. 607–615, 2008. 0 2 4 6 8 10 12 14 -0.5 0 0.5 1 1.5 2 time (s) 1 ˆ m c r p m m m    2 ˆ m c p m m   4 ˆ m x c  5 ˆ m y c  3 ˆ m p m  0 2 4 6 8 10 12 14 0 0.2 0.4 0.6 0.8 1 1.2 1.4 time (s) 2 ˆ a p m  1 ˆ a p m  figure 8. estimated parameters ˆ ( ) m t figure 9. estimated parameters ˆ ( ) a t a.h. vo et al. /j. mechatron. elect. power, and veh. technol. 07 (2016) 27-34 34 [13] j.-h. yang, linear adaptive control-chapter 13: on the adaptive tracking control of 3-d overhead crane system, intech, doi: 10.5772/6511, 2009. [14] n. b. almutairi and m. zribi, “sliding mode control of a three-dimensional overhead crane,” journal of vibration and control, vol. 15, no. 11, pp. 1679–1730, 2009. [15] a. pisano et al., “load swing suppression in the 3-dimensional overhead crane via second-order sliding-modes,” in proc. of the 2010 11 th international workshop on variable structure systems (vss), pp. 452457, 2010. [16] j. h. yang and s. h. shen, “novel approach for adaptive tracking control of a 3-d overhead crane system,” journal of intelligent & robotic systems, vol. 62, no. 1, pp. 59–80, 2010. [17] w. yu, m. a. m. armendariz and f. o. rodriguez, “stable adaptive compensation with fuzzy cmac for an overhead crane,” information sciences, vol. 181, no. 21, pp. 4895–4907, 2011. [18] l. a. tuan et al., “partial feedback linearization control of a three-dimensional overhead crane,” international journal of control, automation and systems, vol. 11, no. 4, pp. 718–727, 2013. [19] r. m. t. r. ismail et al., “nonlinear dynamic modeling and analysis of a 3-d overhead gantry crane system with payload variation,” in proc. of uksim third european modeling symposium on computer modeling and simulation, pp. 350-354, 2009. [20] q. h. ngo and k. s. hong, “sliding-mode anti-sway control of an offshore container crane,” ieee/asme transactions on mechatronics, vol. 17, no. 2, pp. 662–668, 2012. [21] s-j. ying, “dynamics of mechanical systems,” in plastics, ed.virginia: american insitute of areonautics astronautics, 1997, pp. 55-56 mev j. mechatron. electr. power veh. technol 07 (2016) 49-56 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.49-56. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake zaini dalimus a, *, khallid hussain b , andrew j. day b a electrical engineering department, andalas university, indonesia b school of engineering, design and technology, university of bradford, u.k received 19 january 2016; received in revised form 24 may 2016; accepted 24 may 2016 published online 29 july 2016 abstract in mixed-mode braking applications, the electric motor/generator(m/g) and hydraulic pressure valve are controlled to meet the driver’s braking demand. controlling these braking elements is achieved by modulating the current generated by the m/g and adjusting the fluid pressure to the wheel brake cylinders. this paper aims to model and design combined regenerative and hydraulic braking systems which, comprise an induction electric machine, inverter, nimh battery, controller, a pressure source, pressure control unit, and brake calipers. a 15 kw 1500 rpm induction machine equipped with a reduction gear having a gear ratio of 4 is used. a hydraulic brake capable to produce fluid pressure up to 40 bar is used. direct torque control and pressure control are chosen as the control criteria in the m/g and the hydraulic solenoid valve. the braking demands for the system are derived from the federal testing procedure (ftp) drive cycle. two simulation models have been developed in matlab ® /simulink ® to analyze the performance of the control strategy in each braking system. the developed model is validated through experiment. it is concluded that the control system does introduce torque ripple and pressure oscillation in the braking system, but these effects do not affect vehicle braking performance due to the high frequency nature of pressure fluctuation and the damping effect of the vehicle inertia. moreover, experiment results prove the effectiveness of the developed model. keywords: mixed-mode braking; regenerative brake; induction machine; hydraulic brake; direct torque; pulse-wide modulation. i. introduction in a conventional vehicle, braking is provided by the friction on each wheel. the kinetic energy is transformed into heat energy through the process of friction between the two surfaces in contact in the brake; the rotor and the stator. a conventional braking system has been modeled, and it was confirmed through experiment that energy loss during braking appeared in a rear drummed brake temperature rise [1]. meanwhile, a hybrid electric vehicle allows the kinetic energy to be converted into electrical energy using an electric motor/generator (m/g), stored in a battery or an ultra-capacitor and subsequently returned to the m/g, and this is known as regenerative braking. since the m/g capacity to absorb braking energy is limited, the hydraulic brake must be controlled to meet the driver’s demand. the challenge is how to control both regenerative and hydraulic braking systems accurately and effectively, so the braking performance remains the same as the conventional vehicle. many m/gs have been applied in electric vehicles (evs) and hybrid evs, such as permanent magnet brushless (pmbl) drive in the toyota prius and induction drive in the gm ev1 [2]. the advantages of the pmbl drive include high efficiency, high torque density, and high reliability. however, an induction motor is a better choice in terms of lower material and manufacturing costs, and higher durability. it also offers energy saving in free-wheel operation and more flexibility of flux control [3]. * corresponding author.tel: +6281266224644 e-mail: zzaini21@gmail.com http://dx.doi.org/10.14203/j.mev.2016.v7.49-56 z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 50 typical control techniques applied in the pmbl drives are efficiency optimizing, direct torque, artificial intelligence, and position-sensor less controls. direct torque control (dtc) constitutes the closed-loop control system where the controlled state variables are torque and stator flux without a current controller [4]. two common techniques are switching-table-based hysteresis and constant-switching-frequency with space-vector modulation. these work on the principle that the electromagnetic torque can be controlled by changing the load angle for a constant stator flux linkage, where the load angle is the angle between the stator and permanent magnet flux linkage vectors [5]. as in electrical drives for vehicle applications, the conventional braking system has evolved to incorporate advanced feature onboard. for instance, an electrically-assisted actuation called e-act was developed and implemented in the nissan leaf car [6]. to generate pressure in the master cylinder, the vacuum booster was replaced by an electric motor. a stroke sensor in the brake pedal measured the driver’s demand (i.e. the force applied by the driver to the brake pedal) and transmitted it to the engine control unit (ecu) to distribute into regenerative and friction portions. pressure modulation is performed by a linear solenoid valve that allows a smooth pressure rise during braking. the proportional-integral-derivative (pid) technique is used to control solenoid current producing the magnetic force [7]. park et al. [8] conducted an experiment to find the pressure-current relation in normally open (no) and normally closed (nc) valves. in the no valve, the current maintains the pressure difference between the master cylinder and the wheel when the valve was closed, while the current was supplied to the nc valve to allow fluid pressure from the wheel cylinder. it was found that the pressure-current relation in these valves is linear. experimental work has shown that regenerative-friction blending can successfully meet the brake demand, though small errors between target and operated brake forces were observed [6]. aoki et al. [9] also investigated the hydraulic brake response in mixed mode braking and found that the target pressure followed the control pressure closely. in another experimental work by albrichsfeld et al. [10], regenerative and friction brake were blended to stop the vehicle from 90 km/h in 8 seconds without adversely affecting the vehicle deceleration. it shows that at a pedal stroke of 10 mm, the vehicle deceleration was constant at 0.36g. lei et al. [11] simulated brake blending between regenerative and antilock braking system where the electric motor and hydraulic brake were modeled by simple transfer functions. the model was simulated on the roads with low and high friction coefficient. however, the blending performance could not be analyzed accurately as in the experimental work previously mentioned. in this paper, dynamic models of both regenerative braking and friction braking are developed and proved through experiment. the paper is organized so that in section ii, a model of an induction motor, inverter, and battery as the primary components of regenerative braking are derived together with a controller employing direct torque control technique. in section iii, a friction braking model is developed consisting of many components, including accumulator, solenoid valve and wheel cylinder. a pressure control criterion as the control scheme is also presented. the simulations to implement the dynamic models are presented in section iv. section v describes validation of the developed model through experiments. finally, the conclusions are drawn in section vi. ii. regenerative brake model a schematic diagram of the regenerative braking system is shown in figure 1. the current flows from the induction motor to the battery in braking mode and vice versa in traction mode. the torque controller uses voltages, currents, and rotor position measurements to switch on or off the three-phase inverter. to match the voltage level of the inverter and the battery and generate smooth battery current, a dc link is needed. table 1 shows important parameters of regenerative brake components namely induction motor, battery, and dc link. in some cases, dcdc booster is needed to increase the battery voltage but, here, it was not considered. the dc link was then represented by inductor and capacitor. the machine equations in the 𝑑𝑞 reference frame are as described in equations (1) – (5). 𝜓𝑑 = 𝐿𝑑𝑖𝑑 + 𝜓𝑚 (1) 𝜓𝑞 = 𝐿𝑞𝑖𝑞 (2) 𝑢𝑑 = 𝑅𝑠𝑖𝑑 + 𝑑𝜓𝑑 𝑑𝑡 − 𝜔𝑟𝜓𝑞 (3) battery dc link inverter induction motor torque controller command powertrain figure 1. electrical traction/braking system in the hybrid vehicle z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 51 𝑢𝑞 = 𝑅𝑠𝑖𝑞 + 𝑑𝜓𝑞 𝑑𝑡 − 𝜔𝑟𝜓𝑑 (4) 𝑇𝑒 = 3𝑝 2 𝜓𝑑𝑖𝑞 − 𝜓𝑞𝑖𝑑 (5) an inverter is an electronic switch used to convert dc voltage into ac voltage at a specified amplitude and frequency. in a high power electric drive, insulated-gate bipolar transistor (igbt) switches are widely used due to their high switching frequency, high impedance gate and small on state voltage. during traction operation, power flows from the dc source to the electric m/g through the inverter. meanwhile, the m/g acts as a generator during braking and generates ac voltage across the terminal. then, the inverter converts the generated voltage into dc form and stores electrical energy in the battery. in this case, the inverter operates as a rectifier. three types of battery are commercially available for hev and ev application; these are lead-acid, nickel metal hydride (nimh), and lithium ion, each with their own advantages and disadvantages. tremblay et al. [12] developed a simulation model of these batteries and also provided experimental validation. the battery was modeled by a voltage source in series with a resistance whereas the voltage magnitude is affected by many parameters. equation (6) is for discharging, and equation (7) is for charging of nimh battery. 𝑉𝑏𝑎𝑡𝑡 = 𝐸0 − 𝑅𝑖𝑖𝑏 − 𝐾 𝑄𝑏 𝑄𝑏− 𝑖𝑡 𝑖𝑡 + 𝑖∗ + 𝐸𝑥𝑝 𝑡 (6) 𝑉𝑏𝑎𝑡𝑡 = 𝐸0 − 𝑅𝑖𝑖𝑏 − 𝐾 𝑄𝑏 𝑖𝑡 −0.1𝑄𝑏 𝑖∗ − 𝐾 𝑄𝑏 𝑄𝑏− 𝑖𝑡 𝑖𝑡 + 𝐸𝑥𝑝 𝑡 (7) as explained briefly in the introduction, the load angle is modified to control the electromagnetic torque. to analyze the effect of load angle to the torque, the currents in equation (5) can be replaced with fluxes for voltage source inverter-fed induction motor drives, and obtained: 𝑇𝑒 = 𝐿𝑀 𝐿𝑟 𝜓𝑟 1 𝜎𝐿𝑠 𝜓𝑠𝑠𝑖𝑛𝛿𝜓 (8) it shows that applying the selected voltage across motor terminals, the load angle can be increased or decreased. a switching table dtc with a circular stator flux path is used in this research as shown in figure 2. the idea is to select an entry in the optimal switching table of the inverter based on estimation of electromagnetic torque and stator flux linkage. the stator flux linkage reference is derived from motor speed considering constant of torque and power operation. iii. friction brake model unlike a conventional braking system, the hydraulic pressure is not directly controlled by the driver, but utilizes a control device in the form of a solenoid valve. to analyze the braking operation of an electro-hydraulic braking system, the hydraulic circuit of the system and the electric circuit in the solenoid valve must be modeled. the main elements of hydraulic circuit are directional valves, relief valve and brake cylinder where their parameters and values are listed in table 2. the solenoid valve includes an orifice which is a sudden restriction in a flow passage which may have a fixed or variable area. the pressure drop across the orifice is caused by fluid acceleration in turbulent flow, and is given by equation (9). 𝑄 = 𝐶𝑑𝐴0 2 𝑃1− 𝑃2 𝜌 (9) both the discharge coefficient and the orifice are determined by the structural configuration of the control valve. there are three equations governing the dynamics of the solenoid valve as described in equations (10) – (12). table 1. regenerative brake parameters parameters values induction motor power (kw) 15 base speed (rpm) 1500 terminal voltage (v) 140 dc link inductance (h) 0.1 capacitance (mf) 470 battery open-circuit voltage (v) 200 capacity (ah) 123 figure 2. dtc scheme of induction motor for induction motor drives [13] z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 52 𝑑𝑖 𝑑𝑡 = 1 𝐿+𝑖 𝜕𝐿 𝜕𝑖 𝑈 − 𝑅𝑖 − 𝑖𝑣 𝜕𝐿 𝜕𝑥 (10) 𝑑𝑣 𝑑𝑡 = 1 𝑚 𝐹𝑚 𝑥, 𝑖 − 𝐾 𝑥 + 𝐺0 − 𝐹𝑝 𝑥 − 𝑏𝑣−𝐹𝑓 (11) 𝑑𝑡 𝑑𝑡 = 𝑣 (12) the first equation is derived from kirchhoff’s voltage law while the second comes from newton’s law. the relation between force and inductance to current and position is nonlinear. if the current is held constant during the movement at the iron core, the magnetic force is given by equation (13). 𝐹𝑒 = 1 2 𝑖2 𝛽 𝛼+𝛽𝑥 2 (13) the finite element modeling of fluid field in the abs from qi [13] is used to calculate the hydrokinetic force as a function of valve movement. to simplify the solving of equation (10), the magnetic circuit operates in the linear region, therefore the dependence of inductance on current is ignored and by calculation on the magnetic circuit, inductance is given by equation (14). 𝐿 𝑥 = 𝛽 𝛼 + 𝛽𝑥 (14) using a finite element result from qi [14], the inductance saturates at 0.015 h when the current is 2 a regardless plunger positions. therefore, operation in both linear and saturated regions can be approximated by equation (15). 𝐿 𝑥 = 𝛽 𝛼+𝛽𝑥 , 𝑖 ≤ 2 0,015, 𝑖 > 2 (15) the control variable is the solenoid voltage which is switched on or off at high frequency to generate controlled current in the electric circuit and thus control the magnetic force in the valve movement. in this simulation, one inlet valve to increase slave cylinder pressure and one outlet valve to decrease slave cylinder pressure are used in the friction braking system as shown in figure 3. the opening and closing operations of these valves are determined from pressure measurement, and the control criteria are: error>𝜃𝑢𝑝𝑝𝑒𝑟 : pressure apply control 𝜃𝑙𝑜𝑤𝑒𝑟 ≤error≤ 𝜃𝑢𝑝𝑝𝑒𝑟 : pressure hold control error<𝜃𝑙𝑜𝑤𝑒𝑟 : pressure dump control where the error is a difference between desired pressure and measured pressure. firstly, pressure applied control means the inlet valve is directed to open, and the outlet valve is directed to close. secondly, both valves are directed to close in pressure hold control. finally, the controller commands the inlet valve to close and the outlet valve to open in pressure dump control. iv. simulations in the previous research, torque demands for the ftp drive cycle have been derived, and the two results are reproduced here as shown in figure 4 and 5 [15]. for the 15 kw induction motor with nominal speed of 1500 rpm connected to the front axle via the reduction gear (n=4), the regenerative torque at the wheel is 382 nm for vehicle speeds less than 39.5 km/h. however, the available torque is smaller in the constant power region (motor speed > 1500 rpm). since torque demands are lower at higher speeds, the induction motor can provide braking torque required on these braking events. therefore, the friction brake is only applied at very low vehicle speed to stop the vehicle safely. the actual regenerative torque generated by the induction m/g using dtc is plotted in figure 6. as can be seen in the figure, the actual torque table 2. detail specification of hydraulic brake parameters values pressure relief valve maximum passage area (cm 2 ) 0.1 valve pressure setting (bar) 60 valve regulation range (bar) 2 flow discharge coefficient 0.7 critical reynolds number 2000 2-way directional valve maximum passage area (cm 2 ) 15 valve maximum opening (mm) 5 flow discharge coefficient 0.7 critical reynolds number 2000 single-acting hydraulic cylinder piston area (cm 2 ) 3.14 piston stroke (mm) 5 dead volume (cm 3 ) 10 -2 specific heat ratio 1.4 contact stiffness (n/m) 10 6 contact damping (n/m/s) 150 figure 3. friction braking model using pressure control criteria z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 53 closely follows the desired torque though it contains high-frequency ripple (> 2khz) oscillating around the desired torque. here, regenerative torque demand was obtained from torque demand from the driver, soc, and capability curve of electric m/g. if demand is lower than the m/g capacity and soc is not high, then the m/g supplies the braking torque. the above torque response can be generalized to observe all braking events in a drive cycle. however, the effect of torque ripple to the wheel speed cannot be analyzed since it is a backwardfacing simulation where the wheel speed is the input to the model. figure 7 shows the result from the forward-facing model where the inputs are load torque and target torque. the load torque is requested by the driver and the vehicle controller adjusts that torque according to drive capacity and forward to motor controller, called target torque. the figure tells that torque ripple caused by operation of m/g controller does not affect vehicle comfort in terms of steady vehicle speed, thus the driver does not feel the different with conventional vehicle. since the regenerative brake is capable of meeting the driver’s demand, the friction brake is only applied at a very low speed (< 7 km/h) as shown in figure 8. the dotted line is the friction brake demand generated by the hydraulic braking system where it rises steadily at t=618 seconds. the friction demand reaches its maximum value when the regenerative braking is totally disengaged at t = 619 seconds. the interval between t = 617 seconds and t=620 seconds is reproduced in figure 9 to highlight the wheel pressure response to follow the hydraulic brake demand. the pressure is controlled accurately although a small fluctuation can be seen. figure 4. torque demands (initial speed: 51.52 km/h, braking time: 12 seconds) figure 5. torque demands (initial speed: 58.24 km/h, braking time: 17 seconds) figure 6. torque demands (initial speed: 58.24 km/h, braking time: 17 seconds) 114 116 118 120 122 124 0 20 40 60 time (sec) v e h ic le s p e e d ( k m /h ) 114 116 118 120 122 124 0 100 200 300 400 time (sec) b ra k in g t o rq u e ( n m ) regen friction 113 115 117 119 221 223 225 -20 0 20 40 60 80 100 120 time (sec) r e g e n e ra ti v e t o rq u e ( n m ) actual target figure 7. torque and speed of induction motor in the forward-facing model figure 8. torque demands (initial speed: 42.4 km/h, braking time: 9 seconds) 0.4 0.42 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0 20 40 60 80 100 time (sec) b ra k in g t o rq u e ( n m ) 0.4 0.42 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0 50 100 150 200 time (sec) m o to r s p e e d ( ra d /s ) traction load 611 612 613 614 615 616 617 618 619 620 0 20 40 60 time (sec) v e h ic le s p e e d ( k m /h ) 611 612 613 614 615 616 617 618 619 620 0 200 400 time (sec) b ra k in g t o rq u e ( n m ) z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 54 v. validation through experiment experimental data done on toyota auris hybrid was supplied by jaguar land rover uk to investigate pressure control during brake blending. the vehicle was fitted with sensors to measure brake pressures, pedal force, pedal travel, vehicle speed, and wheel speeds. it was braked from 70 km/h with braking time of 11 seconds. figure 10 clearly shows that front wheel pressure was modulated to meet brake demand in terms of brake pedal travel. after t = 4 seconds, the pedal was held at about 16.5 mm and returned to initial position when t > 14 seconds. initially, the front pressure rose with pedal travel and was maintained at about 6 bar. however, it was gradually reduced after t = 7 seconds who indicates that regenerative brake portion increased. at lower vehicle speeds, the front pressure was increased to 10 bar again to stop the vehicle completely. this front pressure response is then used to validate the model of a proposed hydraulic brake system. as shown in figure 11, the model successfully follows the auris front pressure despite pressure spikes appeared in the output. hydraulic pressure overshot could be lowered by reducing duty cycle of pwm voltage to the coil as shown in figure 12. here, the set point is 10 bar and three pwm signals were compared and signal with the 25% duty cycle exhibit lower overshot value. the second braking data was obtained from nissan leaf ev. the brake pedal travel demanded by the driver and resulted from front brake pressure are shown in figure 13. compared with auris hybrid, the brake condition is more challenging since it exhibited fluctuating brake demand. pedal force from the driver was then converted into total braking torque demand as shown in figure 14. next, it was split into regenerative and hydraulic front wheel brakes. in response to driver demand, the regenerative torque also oscillated during braking period and figure 9. controlled wheel pressure in mixed-mode braking system figure 10. pedal travel and front pressure of auris braking system figure 11. comparing model output with the experimental result on auris hybrid 617.0 671.5 618.0 618.5 619.0 619.5 620.0 0 5 10 15 20 25 time (sec) w he el p re ss ur e (b ar ) 4 6 8 10 12 14 0 2 4 6 8 10 12 14 16 18 20 time (sec) b a r, m m front pressure pedal travel 0 2 4 6 8 10 12 0 2 4 6 8 10 12 time (sec) p re s s u re ( b a r) simulation experiment figure 12. wheel pressure responses for different pwm ratios figure 13. pedal travel and front pressure of nissan leaf braking system 0.4 0.42 0.44 0.46 0.48 0.5 0 2 4 6 8 10 12 14 16 18 20 time (sec) w h e e l p re s s u re ( b a r) pwm 25% pwm 50% pwm 75% 0 2 4 6 8 10 12 14 16 18 0 5 10 15 20 25 30 35 40 time (sec) m m , b a r travel pressure z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 55 tried to optimize energy recovery as shown in the figure. the front brake pressure became set point in simulation model and was plotted together with a pressure response in figure 15. as can be seen, the pressure response generated by the model closely followed the set point. an interesting condition was observed in which the pressure can not be increased to meet the demand around t = 12 sec. observing responses in figure 16, this was caused by source pressure in the accumulator decreased significantly as a result from pressure dump control discussed in section iii. vi. conclusions the applications of direct torque control and pressure control criteria on mixed-mode braking system has been explored through simulation as well as experiment. the conclusions to be made are: first, regenerative braking torque is maximized and friction braking must provide the difference with driver demand under all operating conditions. second, a 15 kw 1500 rpm induction motor satisfies the most braking demand in the ftp drive cycle while the friction portion is dominant at low speeds in that cycle when regenerative braking is ineffective. third, regenerative torque generated contains a high frequency ripple but this does not affect vehicle deceleration. finally, a lower ratio of pwm signal is better to control pressure because it generates lower of overshoot. references [1] zaini dalimus, “braking system modeling and brake temperature response to repeated cycle,” journal of mechatronics, electrical power, and vehicular technology, 2014, vol.05, pp. 123-128. doi:10.14203/j.mev.2014.v5.123-128. [2] chau, k. t et al., “overview of permanentmagnet brushless drives for electric and hybrid electric vehicles,” ieee transactions on industrial electronics, 2008, 55, (6), pp. 2246-2257. doi:10.1109/tie.2008.918403. [3] dorrell, d.g et al., d.a.: “comparison of different motor design drives for hybrid electric vehicles,” energy conversion congress and exposition, 2010, pp. 3352 – 3359. doi:10.1109/ecce.2010.5618318. [4] khoucha, f et al., m.e.h. : “improved sensorless dtc scheme for ev induction motors,” 2007 ieee international electric machines & drives conference, antalya, 2007, pp. 1159-1164. doi: 10.1109/iemdc.2007.383594. [5] vyncke, t. j et al., “direct torque control of permanent magnet synchronous motors – an overview,” 3rd ieee benelux young researchers symposium in electrical power engineering, ghent, belgium, 2006, pp. 1-5. doi: 10.1109/iecon.2009.5414686 [6] ohtani, y et al., “development of an electrically-driven intelligent brake unit,” sae techical paper, 2011-01-0572. 2007. doi: 10.4271/2011-01-0572. [7] yuan, d et al., “simulation of hydraulic brake built-in test system for a certain uav,” figure 14. pedal travel and front pressure of nissan leaf braking system figure 15. comparing model output with the experimental result on leaf ev figure 16. effect of source pressure on brake response 0 2 4 6 8 10 12 14 16 18 0 100 200 300 400 500 600 700 800 900 1000 1100 time (sec) b ra k in g t o rq u e ( n m ) total regenerative 0 2 4 6 8 10 12 14 16 18 -5 0 5 10 15 20 25 30 35 40 time (sec) fr o n t p re s s u re ( b a r) experiment simulation 0 2 4 6 8 10 12 14 -10 0 10 20 30 40 50 60 time (sec) p re s s u re ( b a r) accumulator front wheel z. dalimus et al. / j. mechatron. electr. power veh. technol 07 (2016) 49-56 56 control conference (ccc), 2013 32nd chinese, xi'an, 2013, pp. 801-804. [8] park, m. et al., “development of the control logic of electronically controlled hydraulic brake system for hybrid vehicle,” sae technical paper 2009-01-1215, 2009, pp. 17. doi: 10.4271/2009-01-1215. [9] aoki, y et al.,“development of hydraulic servo brake systemfor cooperative control with regenerative brake,” sae technical paper 2007-01-0868, 2007, pp. 1-9. doi: 10.4271/2007-01-0868 [10] albrichsfeld, c. v.and karner, j.: “brake system for hybrid and electric vehicles,” saetechnical paper2009-01-1217, 2009, pp. 1-7. doi: 10.4271/2009-01-1217. [11] lei, z., yugong, let al., “a novel brake control strategy for electric vehicles based on slip trial method,” vehicular electronics and safety, 2007. icves. ieee international conference on, beijing, 2007, pp. 1-6. doi: 10.1109/icves.2007.4456364. [12] tremblay and o., dessaint, l. a.: “experimental validation of a battery dynamic model for ev applications,” world electric vehicle journal, 2009, 3, pp. 1-10 [13] ghorbani, m. jet al.,.“direct torque control of induction motor by active learning method,” power electronic & drive systems & technologies conference (pedstc), 2010 1st, tehran, iran, 2010, pp. 267-272. doi: 10.1109/pedstc.2010.5471817. [14] qi, x. et al.,“influence of hydraulic abs parameters on solenoid valve dynamic response and braking effect,” saetechnical paper2005-01-1590, 2005, pp. 1-12. doi: 10.4271/2005-01-1590. [15] zaini, z.et al.,“mixed-mode braking system for road vehicles with regenerative braking,” 6th european conference on braking, lille, france, 2010, pp. 115-122. nomenclature variable definition id d-axis component of current iq q-axis component of current ψd d-axis component of flux ψq q-axis component of flux ψm magnetizing flux ψs stator flux linkage ψr rotor flux linkage ud d-axis component of voltage uq q-axis component of voltage ld d-axis component of inductance lq q-axis component of inductance ls stator leakage inductance lr rotor leakage inductance lm mutual inductance rs stator resistance σ leakage factor ωr rotor speed δψ load angle te electromagnetic torque vbatt battery voltage e0 battery constant voltage it actual battery charge i∗ filtered current qb battery capacity exp(t) exponential zone voltage ri internal resistance k polarisation constant q volumetric flow rate cd coeeficient of discharge  fluid density a0 cross-sectional area of the orifice p1 fluid upstream pressure p2 fluid downstream pressure i coil current u coil voltage l coil inductance r coil resistance m plunger mass k spring constant b viscous damping constant x plunger position v pluger speed ff frictional force fm magnetic force fp hydrokinetic force microsoft word vol03_no2 yg dioprek neli sutisno dan muhida-nya journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 03, 2012 abstracts sheet e-issn: 2088-6985 date of issues vol. 3, no. 1: july 2012 p-issn: 2087-3379 date of issues vol. 3, no. 2: december 2012 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. ridwan arief subekti a, agus hartanto a, vita susanti a (a pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) direction and policies needed to support hybrid electric car research (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 1-8, 4 ill, 13 ref. the rising number of vehicles over the years has driven the increase of air pollution and fuel consumption. one of the solutions to overcome this problem is using hybrid electric car because it is environmentally friendly and efficient in fuel consumption. lipi has conducted electric car research since 1997, but there were so many problems in its development that electric car cannot be developed into a national industry scale. therefore, it is important to conduct a study that maps the problems and finds the solutions to prevent the same failure of electric car commercialization process from happening to hybrid electric car. this study was done by collecting and analyzing the primary and secondary data through interviews, discussing electric hybrid car with stakeholders, and examining earlier study results and regulations. based on this study, several policies to support sustainability research of hybrid electric car were proposed. some recommendations were the making of national roadmap and regulation for the usage of hybrid electric car on the road. for policy makers at lipi, a research focus, research coordination, and precommercialization program were recommended. (author) keywords: national policy, hybrid electric cars, research, air pollution, national road map. hendri maja saputra a, zainal abidin b, estiko rijanto a (a pusat penelitian tenaga listrik dan mekatronik– lipi, bandung; b teknik mesin, fakultas teknik mesin dan dirgantara– itb, bandung) analysis of inverse angle method for controlling two degree of freedom manipulator (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 9-16, 13 ill, 4 tab, 16 ref. driver mechanism with two degree of freedom (mp 2-dk) is a robotic device that can be used for various applications such as turret drive system, gutling gun, launcher, radar antennas, and communications satellite antennas. the precision and the speed of a mp 2-dk are determined by its control system. the calculation inverse angle due to interference in six degree of freedom is necessary to control a mp 2 dk. this paper analyses three calculation methods of inverse angle which are iteration method using jacobian matrix, reduction of matrix equations using positioning geometry, and an analytical derivation using a rotation matrix. the simulation results of the three methods showed that the first and the third methods could visually demonstrate three rotational disturbances, whereas the second method could only demonstrate the pitch and yaw (py) disturbances. the third method required less processing time than the first and the second methods. the best method based on this research was the method of rotation matrix. (author) keywords: driver mechanism, control, inverse angle, jacobian, geometry kristian ismail a, syamsu ismail b (a pusat penelitian tenaga listrik dan mekatronik– lipi, bandung; b pusat penelitian elektronika dan telekomunikasi – lipi, bandung) development of discrete power supply with charge pump method for high powered sonar system (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 17-22, 12 ill, 0 tab, 10 ref. power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. there are several types of power supplies that can be applied depend on the requirement and functions. one example is the use of power supply for sonar systems. sonar system is a device which can be used to detect a target under water. the sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on) and the specific lag time (when off). this paper discusses the design of power supply for highpowered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. charge pump was used to get the appropriate output voltage from lower input voltage. charge pump utilized a combination of series and parallel connections of capacitors. the working mode of this power supply used the lag time as the calculation of time to charge journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series. (author) keywords: power supply, charge pump, discrete method. pudji irasari a, hilman syaeful alam b, muhammad kasim a (a pusat penelitian tenaga listrik dan mekatronik– lipi, bandung; b upt balai pengembangan instrumentasi– lipi, bandung) magnetic simulation and analysis of radial flux permanent magnet generator using finite element method (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 23-30, 13 ill, 3 tab, 21 ref. this paper discusses magnetic simulation and analysis of radial flux permanent magnet generator (pmg) using finite element method (fem) by utilizing open source software femm 4.2. the specification of generator is 25 v, 28 a, 3 phase, 300 rpm. the analyzed magnetic flux was in the air gap, stator teeth and slots to find out the distribution pattern and its fluctuation. the simulations were conducted in noload and nominal load (28 a) conditions. furthermore, the maximum flux density of simulation (bg(sim)) was used to calculate phase voltage eph to find out the magnitude of generated electromotive force (emf). the calculation results were presented as voltage vs. rotation graph in noload condition and voltage vs. current graph in nominal load condition. both graphs were validated using eph from experiment result (eph(exp)) and eph whose bgvalue was obtained from analytical calculation (eph(calc)). the final results showed that in no-load condition, eph graph with bg(sim) (eph(sim)) was close to eph(exp) and eph(calc). the error rate with respect to the experiment was 6,9%. in nominal load condition, eph(sim) graph almost coincided with eph(calc.) graph, with the voltage drop of both was 0.441 v. both graphs however were far different from eph(exp) graph, which had 9 v of voltage drop. the overall results demonstrated that magnetic distribution pattern presented by fem was very helpful to avoid magnetic flux accumulation in a particular segment. besides, bg(sim) made the process to predict the value of ephbecome easier. (author) key words: simulation, magnetic flux, generator, permanent magnet, finite element . muh. zakiyullah romdlony a, amin a, b (a sekolah teknik elektro dan informatika, institut teknologi bandung, bandung; b pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) design and implementation of anti-windup pi control on dc-dc bidirectional converter for hybrid vehicle applications (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 31-38, 16 ill, 2 tab, 10 ref. well-regulated dc bus voltage is the important point to guarantee power demand fulfillment in hybrid vehicle applications. voltage regulation can be achieved with control method that determines switching signal on dc-dc converter. this paper describes the design and small scale experiment results of bus voltage regulation control for dcdc bidirectional converter with battery and super capacitor as energy sources. the control system consisted of two control loops. the outer loop got dc bus voltage feedback using anti-windup pi back calculation control method. this outer loop would generate a reference current for the inner loop that implemented hysteresis control. the inner control loop compared that reference current with the source current obtained from the current sensor. simulation and experiment results showed that bus voltage was well-regulated under the load changes of 1% ripple voltage. (author) keywords: anti-windup pi, hysteresis, dc-dc bidirectional converter edi leksono a, justin pradipta a, tua agustinus tamba b (a laboratorium manajemen energi, teknik fisika – institut teknologi bandung, bandung; b department of electrical engineering – university of notre dame, usa) modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 39-48, 10 ill, 2 tab, 19 ref. one essential parameter in fuel cell operation is oxygen excess ratio which describes comparison between reacted and supplied oxygen number in cathode. oxygen excess ratio relates to fuel cell safety and lifetime. this paper explains development of air feed model and oxygen excess ratio calculation in commercial self-humidified pem fuel cell system with 1 kw output power. this modelling was developed from measured data which was limited in open loop system. it was carried out to get relationship between oxygen excess ratio with stack output current and fan motor voltage. it generated fourth-order 56.26% best fit arx linear polynomial model estimation (loss function = 0.0159, fpe = 0.0159) and second-order arx nonlinear model estimation with 75 units of wavenet estimator with 84.95% best fit (loss function = 0.0139). the second-order arx model linearization yielded 78.18% best fit (loss function = 0.0009, fpe = 0.0009). (author) keywords: pem fuel cell, self-humidified, oxygen excess ratio, system identification, polynomial model arifin nur a, yanuandri putrasari a, iman kartolaksono reksowardojo b (a bidang sarana peralatan transportasi, pusat penelitian tenaga listrik dan mekatronik-lipi, bandung; b laboratorium motor bakar dan sistem propulsi, institut teknologi bandung, bandung) the effect of ethanol-diesel blends on the performance of a direct injection diesel engine (orig. ind.) mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, p. 49-56, 9 ill, 2 tab, 26 ref. the experiment was conducted on a conventional direct injection diesel engine. performance test was carried out to evaluate the performance and emission characteristics of a conventional diesel engine that operates on ethanol-diesel blends. the test procedure was performed by coupling the diesel engine on the eddy current dynamometer. fuel consumption was measured using the avl fuel balance, and a hotwire anemometer was used to measure the air consumption. some of the emission test devices were mounted on the exhaust pipe. the test of fuel variations started from 100% diesel fuel (d100) to 2.5% (de2.5), 5% (de5), 7.5% (de7.5), and 10% (de10) ethanol additions. performance test was conducted at 1500 rpm with load journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 v variations from 0 to 60 nm by increasing the load on each level by 10 nm. the addition of 5% ethanol to diesel (de5) increased the average pressure of combustion chamber indication to 48% as well as reduced the specific fuel consumption to 9.5%. there were better exhaust emission characteristics at this mixture ratio than diesel engine which used pure diesel fuel (d100), the reduction of co to 37%, hc to 44% and opacity to 15.9%. (author) key words: performance test, fuel supplement, bioethanol, emission, diesel engine. asmara yanto a, zainal abidin b (a teknik mesin, fakultas teknologi industri – itp, padang; b teknik mesin, fakultas teknik mesin dan dirgantara – itb, bandung) development of swept-sine excitation control method to minimize the frf measurement error mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 57-64, 10 ill, 3 tab, 19 ref. shaker excitation in frf (frequency response function) measurement of a testing system can be controlled by using swept-sine signal source in a signal generator and it is called with swept-sine excitation. frf’s magnitude error of the system which be obtained from the frf measurement using swept-sine excitation depends on swept function of sweptsine signal. in this paper, swept-sine signals using linear and s535 swept functions have been simulated to controlling swept-sine excitation in the frf measurement of sdof (single degree of freedom) system. linear swept is swept function of swept-sine signal which often be used in the frf measurement and s535swept is a swept function has been developed in this paper. based on simulation results, the frf’s magnitude error at system’s resonant frequency which be obtained from the frf measurement using linear swept-sine excitation can be minimized by redoing the frf measurement using s535 swept-sine excitation. (author) keywords: frf, swept-sine, linear swept, s535 swept, magnitude. edy riyanto a, b, c, estiko rijanto b, budi prawara b (a state key laboratory for modification of chemical fibers and polymer materials, china; b research centre for electrical power & mechatronics, indonesian institute of sciences, bandung) a review of atomic layer deposition for nanoscale devices mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 65-72, 8 ill, 0 tab, 53 ref. atomic layer deposition (ald) is a thin film growth technique that utilizes alternating, self-saturation chemical reactions between gaseous precursors to achieve a deposited nanoscale layers. it has recently become a subject of great interest for ultrathin film deposition in many various applications such as microelectronics, photovoltaic, dynamic random access memory (dram) and microelectromechanic system (mems). by using ald, the conformability and extremely uniformity of layers can be achieved in low temperature process. it facilitates to be deposited onto the surface in many variety substrates that have low melting temperature. eventually it has advantages on the contribution of the wider nanodevices (author) key words: thin coating, atomic layer deposition, nanoscale devices. agus risdiyanto a, b, noviadi arief rachman b, maulana arifin b (a sekolah teknik elektro dan informatika, institut teknologi bandung, bandung; b pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection (orig. ind.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 73-80, 11 ill, 2 tab, 12 ref. this paper discussed the influence of tightness or contacts pressure on copper busbar joints to determine changes in the value of the initial contact resistance and the maximum temperature at the joint due to high current load. the test sample using copper busbar 3 x 30 mm with configuration of bolted overlapping joint. increasing contact pressure at the joint was measured to find out its effect on the value of contact resistance. the applied pressure was 6 to 36 mpa. procedure of contact resistance measurement refers to the astm b539 standard using four-wire method. the sample subsequently loaded with the current of 350 a for 60 minutes and the maximum temperature at the joint was measured. the result shows that increasing contact pressure at the busbar joint will reduce the contact resistance and maximum temperature. the increasing of contact pressure from 6 to 30 mpa causes decreasing contact resistance from 16 μω to11 μω. further increasing of contact pressure more than 30 mpa didn’t affect the contact resistance significantly. the lowest temperatur of busbar joint of 54°c was reached at a contact pressure of 36 mpa. (author) key words: contact pressure, contact resistance, maximum temperature, copper busbar joint. arini wresta a, b, wiratni budhijanto a (a laboratory of food and bioprocess engineering, chemical engineering department, faculty of engineering, gadjah mada university, yogyakarta; b research centre for electrical power and mechatronics-indonesian institute of sciences, bandung) the effect of the addition of active digester effluent for start-up accelerator in anaerobic digestion of soybean curd industry waste water (basic research for biogas power generation) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 81-86, 2 ill, 0 tab, 17 ref. biogas production from soybean curd industry waste water was studied in laboratory scale to improve the application of anaerobic digestion process. the problem with the soybean curd waste water was the fact that it did not sufficiently contain anaerobic microorganisms required in biogas production. therefore, it is necessary to add a welldeveloped population of anaerobic microorganisms to accelerate the start-up of the anerobic digestion. this research was aimed to verify the influence of the addition of active digester effluent into the soybean curd waste water batches in an anaerobic digestion process. batch experiments were done in two digesters. the first digester was only fed with soybean curd waste water while the second digester was fed with soybean curd waste water and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vi active digester effluent from a digester processing cow manure which was very rich in anaerobic microorganism consortium. the results indicated that soybean curd industry waste water did not contain methanogenic bacteria but there were existed some acidogenic bacteria. the addition of active digester effluent accelerated the anaerobic digestion start-up and directed the process pathway towards methanogenic process so that more methane was obtained. the high methane content obtained (more than 64% volume) was very potential for power generation. the capacity of soybean curd industry must be as high as 697.13 kg soybean per day to generate the electric energy of 8.4 kwh. (author) key words: active digester effluent, start-up, anaerobic digestion, soybean curd waste water, anaerobic bacteria, methanogenic process, electric energy. hilman s. alam a, pudji irasari b, and dyah kusuma dewi c (a technical implementation unit for instrumentation development, indonesian institute of sciences, bandung; b research center for electrical power and mechatronics, indonesian institute of sciences, bandung; c directorate of technology for manufacturing industry, agency for assessment and application of technology, serpong) analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 87-94, 12 ill, 1 tab, 17 ref. analytical and numerical studies of the deflection in the structure of 10 kw low speed permanent magnet generator (pmg) have been discussed in this paper. this study is intended to prevent failure of the structure when the prototype is made. numerical analysis is performed with the finite-element method (fem). flux density, weight and temperature of the components are the required input parameters. deflection observed is the movements of the two main rotor components, namely the rim and shaft, is here the maximum allowable deflection at the air gap between rotor and stator should be between 10% to 20% of the air gap clearance or 0.1000 mm to 0.2000 mm. base on the analysis, total deflection of the analytic calculation is 0.0553 mm, and numerical simulation is 0.0314 mm. both values are in the acceptable level because it is still below the maximum allowable deflection. these results indicate that the structure of a permanent magnet generator (rim and shaft) can be used safely. (author) keywords: permanent magnet generator, finite element, air gap, deflection. riza muhida a, b, ahmad firdaus a. zaidi c, afzeri tamsir a, b, rudi irawan b, d (a department of informatics and computer, surya college of education (stkip surya), serpong; b international institute for clean energy and climate change (iicecc), serpong; c school of mechatronics engineering, university malaysia perlis, malaysia; d department of physics, surya college of education (stkip surya), serpong) design of a dc-ac link converter for 500w residential wind generator mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 95-102, 10 ill, 2 tab, 24 ref. as one of alternative sources of renewable energy, wind energy has an excellence prospect in indonesia, particularly in coastal and hilly areas which have potential wind to generate electricity for residential uses. there is urgent need to locally develop low cost inverter of wind generator system for residential use. recent developments in power electronic converters and embedded computing allow improvement of power electronic converter devices that enable integration of microcontrollers in its design. in this project, an inverter circuit with suitable control scheme design was developed. the circuit was to be used with a selected topology of wind energy conversion system (wecs) to convert electricity generated by a 500w directdrive permanent magnet type wind generator which is typical for residential use. from single phase ac output of the generator, a rectifier circuit is designed to convert ac to dc voltage. then a dc-dc boost converter is used to step up the voltage to a nominal dc voltage suitable for domestic use. the proposed inverter then will convert the dc voltage to sinusoidal ac. the duty cycle of sinusoidal pulse-width modulated (spwm) signal controlling switches in the inverter was generated by a microcontroller. the lab-scale experimental rig involves simulation of wind generator by running a geared dc motor coupled with 500w wind generator where the prototype circuit was connected at the generator output. the experimental circuit produced single phase 240v sinusoidal ac voltage with frequency of 50hz. measured total harmonics distortion (thd) of the voltage across load was 4.0% which is within the limit of 5% as recommended by ieee standard 519-1992. (author) key words: wind energy, inverter, converter, microcontroller, generator, residential electricity. gerald wahyudi setiono a, prianggada indra tanaya b, henricus riyanto hendradji a (a department of mechatronics engineering, swiss german university, serpong; b department of industrial engineering, swiss german university, serpong) analysis and development of walking algorithm kinematic model for 5-degree of freedom bipedal robot mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 103-110, 11 ill, 3 tab, 15 ref. a design of walking diagram and the calculation of a bipedal robot have been developed. the bipedal robot was designed and constructed with several kinds of servo bracket for the legs, two feet and a hip. each of the bipedal robot leg consists of 5-degrees of freedom, three pitches (hip joint, knee joint and ankle joint) and two rolls (hip joint and ankle joint). the walking algorithm of this bipedal robot was based on the triangle formulation of cosine law to get the angle value at each joint. the hip height, height of the swinging leg and the step distance are derived based on linear equation. this paper discussed the kinematic model analysis and the development of the walking diagram of the bipedal robot. kinematics equations are derived, the joint angles are simulated and coded into arduino board to be executed to the robot. (author) keywords: bipedal robot, kinematics model, kinematics analysis, 5-degree of freedom, walking algorithm. sutisno a, andreas prasetya adi a (a lapan) vibration disturbance damping system design to protect journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 vii payload of the rocket mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, p. 111-116, 8 ill, 0 tab, 13 ref. rocket motor generates vibrations acting on whole rocket body including its contents. part of the body which is sensitive to disturbance is the rocket payload. the payload consists of various electronic instruments including : transmitter, various sensors, accelerometer, gyro, the embedded controller system, and others. this paper presents research on rocket vibration influence to the payload and the method to avoid disturbance. avoiding influence of vibration disturbance can be done using silicone gel material whose typical damping factors are relatively high. the rocket vibration was simulated using electromagnetic motor, and the vibrations were measured using an accelerometer sensor. the measurement results were displayed in the form of curve, indicating the vibration level on some parts of the tested material. some measurement results can be applied to determine the good material to attenuate vibration disturbance on the instruments of the payload key words: motor, rocket, vibration, payload, silicone. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 viii journal of mechatronics, electrical power, and vehicular technology volume 03, 2012 lembar abstrak e-issn: 2088-6985 bulan terbit vol. 3, no. 1: juli 2012 p-issn: 2087-3379 bulan terbit vol. 3, no. 2: desember 2012 kata kunci yang dicantumkan adalah istilah bebas. lembar abstrak ini dapat diperbanyak tanpa izin dan biaya. ridwan arief subekti a, agus hartanto a, vita susanti a (a pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) arah dan kebijakan yang diperlukan dalam menunjang penelitian mobil listrik hibrid mechatronics, electrical power, and vehicular technology, juli 2012, vol. 3, no. 1, hal. 1-8, 4 ill, 0 tab, 13 ref. peningkatan jumlah kendaraan bermotor dari tahun ke tahun menyebabkan peningkatan pencemaran udara dan konsumsi bbm. salah satu cara untuk mengatasi masalah tersebut adalah dengan menggunakan kendaraan mobil listrik hybrid karena ramah lingkungan dan hemat bbm. lipi telah mengembangkan penelitian mobil listrik sejak tahun 1997. akan tetapi muncul berbagai permasalahan yang menyebabkan mobil listrik tersebut tidak dapat berkembang ke skala industry nasional. oleh karena itu dilakukan suatu kajian untuk memetakan permasalahan dan mencari solusi agar kegagalan proses komersialisasi mobil listrik tidak terulang pada mobil listrik hibrid yang saat ini penelitiannya masih berjalan. kajian ini dilakukan dengan mengumpulkan dan menganalisis data primer dan sekunder melalui wawancara, diskusi dengan pihak terkait, serta mempelajari hasil kajian dan peraturan yang ada. berdasarkan kajian ini selanjutnya direkomendasikan beberapa usulan kebijakan untuk menunjang kesinambungan penelitian mobil listrik hibrid. beberapa rekomendasi yang diusulkan antara lain adalah perlunya dukungan pemerintah pusat melalui program nasional mobil listrik hibrid yang didukung dengan adanya road map nasional dan peraturan legalitas penggunaan mobil listrik hibrid di jalan raya, sedangkan untuk pengambil kebijakan di lingkungan lipi, direkomendasikan adanya focus penelitian, koordinasi penelitian dan program pra komersialisasi. (penulis) kata kunci: kebijakan nasional, mobil listrik hibrid, penelitian, polusi udara, road map nasional. hendri maja saputra a, zainal abidin b, estiko rijanto a (a pusat penelitian tenaga listrik dan mekatronik – lipi, bandung; b teknik mesin, fakultas teknik mesin dan dirgantara – itb, bandung) analisis metode sudut balik untuk pengendalian mekanisme penggerak dua derajat kebebasan mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 9-16, 13 ill, 4 tab, 16 ref. mekanisme penggerak dua derajat kebebasan (mp 2-dk) merupakan peralatan robotik yang dapat digunakan untuk berbagai aplikasi seperti system penggerak turret, peluncur roket/rudal, antena radar, dan antenna komunikasi satelit. tingkat presisi dan kecepatan gerak mp 2-dk sangat ditentukan oleh system kendalinya. untuk pengendalian mp 2-dk perlu dihitung sudut balik akibat gangguan enam derajat kebebasan (rotasi: roll, pitch, yaw, translasi:bx, by, bz). makalah ini membahas hasil analisis 3 metode perhitungan sudut balik, antara lain metode iterasi menggunakan matriks jacobian, penurunan persamaan geometri menggunakan matriks posisi, dan penurunan secara analitis menggunakan matriks rotasi. hasil simulasi dari ketiga metode membuktikan bahwa metode pertama dan ketiga secara visual dapat mempresentasikan ketiga gangguan rotasi yang terjadi, sedangkan metode kedua hanya mempresentasikan gangguan pitch dan yaw (py) saja. metode ketiga memerlukan waktu proses lebih cepat dari pada metode pertama dan metode kedua. metode yang terbaik berdasarkan penelitian ini adalah metode ketiga (metode matriks rotasi). (penulis) kata kunci: mekanisme penggerak, pengendalian, sudut balik, jacobian, geometri. kristian ismail a, syamsu ismail b (a pusat penelitian tenaga listrik dan mekatronik– lipi, bandung; b pusat penelitian elektronika dan telekomunikasi – lipi, bandung) rancang bangun catu daya diskrit dengan metode charge pump untuk sistem sonar berdaya tinggi mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 17-22, 12 ill, 0 tab, 10 ref. catu daya adalah salah satu perangkat elektronika yang dapat menyediakan energy listrik untuk system elektronika atau system lainnya. terdapat beberapa jenis catu daya yang dapat diaplikasikan sesuai dengan kebutuhan dan fungsinya, salah satu contohnya adalah penggunaan catu daya untuk sistem sonar. sistem sonar adalah alat pendeteksi keberadaan target di bawah air, system tersebut berupa rangkaian elektronika yang memerlukan catu daya dengan karakteristik yang spesifik. catu daya dibutuhkan pada saat sonar sebagai pemancar dan sebagai penerima dalam rentang journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ix waktu (saat on) dan jeda waktu (saat off) yang spesifik. untuk memenuhi karakteristik danb spesifikasi tersebut, maka digunakan catu daya diskrit yang menggunakan metode charge pump untuk mengumpulkan energy listriknya. dalam tulisan ini dibahas tentang rancang bangun catu daya yang digunakan untuk menyediakan energy listrik bagi sistem sonar berdaya tinggi dengan metoda diskrit yaitu pengaktifan catu daya tinggi tidak kontinyu melainkan hanya pada saat gelombang akustik diradiasikan di bawah air. metoda pengumpulan energy ke komponen pengubah tegangan menggunakan charge pump. charge pump pada catu daya yang dikembangkan ini memanfaatkan kombinasi hubungan seri dan parallel kapasitor. cara kerja catu daya ini menggunakan jeda waktu sebagai perhitungan waktu untuk pengisian kapasitor charge pump secara parallel sedangkan rentang waktu digunakan untuk perhitungan pengosongan kapasitor charge pump secara seri. (penulis) kata kunci: catu daya, charge pump, metode diskrit. pudji irasari a, hilman syaeful alam b, muhammad kasim a (a pusat penelitian tenaga listrik dan mekatronik– lipi, bandung; b upt balai pengembangan instrumentasi– lipi, bandung) simulasi dan analisis magnetik generator magnet permanen fluks radial menggunakan metoda elemen hingga mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 23-30, 13 ill, 3 tab, 21 ref. dalam makalah ini dibahas simulasi dan analisis magnetik generator magnet permanen (gmp) fluks radial menggunakan metoda elemen hingga (meh) dengan perangkat lunak terbuka femm 4.2. generator memiliki spesifikasi 25 v, 28 a, 3 fasa, 333 rpm. fluks magnet yang dianalisis adalah pada celah udara, gigi dan alur stator untuk mengetahui pola distribusi dan fluktuasinya. simulasi dilakukan dalam keadaan tanpa beban dan dengan beban nominal (28 a). selanjutnya kerapatan fluks celah udara maksimum hasil simulasi (bg(sim)) digunakan untuk menghitung tegangan fasa eph guna mengetahui besarnya electromotive force (emf) yang dibangkitkan. hasil perhitungan ditampilkan berupa grafik tegangan vs. putaran untuk kondisi tanpa beban dan grafik tegangan vs. arus untuk kondisi beban nominal. kedua grafik tersebut divalidasi dengan eph hasil eksperimen (eph(exp)) daneph yang nilai bg nya diperoleh dari perhitungan analisis (eph(calc)). hasil akhir menunjukkan bahwa dalam kondisi tanpa beban grafik eph dengan bg(sim) (eph(sim)) mendekati eph(exp) maupun eph(calc). tingkat kesalahan terhadap eksperimen sebesar 6,9%. untuk kondisi beban nominal, grafik eph(sim) hamper berimpit dengan eph(calc.), dengan tegangan jatuh keduanya sebesar 0,441 v. namun kedua grafik tersebut berbeda cukup jauh dengan grafik eph(exp) yang tegangan jatuhnya 9 v. dari keseluruhan hasil yang diperoleh menunjukkan bahwa pola distribusi magnet yang disajikan oleh meh sangat membantu untuk menghindari penumpukan fluks magnet pada segmen tertentu. selain itu bg(sim) sangat memudahkan dalam memprediksi besarnya eph. (penulis) kata kunci: simulasi, fluks magnet, generator, magnet permanen, elemen hingga. muh. zakiyullah romdlony a, amin a, b (a sekolah teknik elektro dan informatika, institut teknologi bandung, bandung; b pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) perancangan dan implementasi kendali pi anti-windup pada konverter dc-dc dua arah untuk aplikasi kendaraan hibrid mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 31-38, 16 ill, 2 tab, 10 ref. tegangan dc bus yang teregulasi dengan baik merupakan hal yang sangat penting pada aplikasi kendaraan hibrid, karena menjamin terpenuhi permintaan daya beban. regulasi tegangan dapat dicapai dengan menerapkan metode kendali tertentu yang akan menentukan sinyal penyaklaran pada konverter dc-dc. paper ini menjelaskan perancangan dan hasil eksperimen kendali regulasi tegangan bus pada konverter dc-dc dua arah (bidirectional converter) untuk skala kecil, dengan sumber berupa baterai dan superkapasitor. sistem kendali terdiri dari dua buah loop kendali. loop kendali luar mendapatkan umpan balik dari tegangan bus menerapkan metoda anti-windup pi back calculation. pengendali ini akan menghasilkan arus referensi untuk loop kendali dalam yang menerapkan kendali histeresis. loop kendali dalam membandingkan arus referensi tersebut dengan arus sumber yang diperoleh dari bacaan sensor arus. hasil simulasi dan eksperimen menunjukkan bahwa tegangan bus teregulasi dengan baik ketika terjadi perubahan beban dengan riak tegangan sekitar 1%. (penulis) kata kunci: anti-windup pi, histeresis, konverter dc-dc dua arah. edi leksono a, justin pradipta a, tua agustinus tamba b (a laboratorium manajemen energi, teknik fisika – institut teknologi bandung, bandung; b department of electrical engineering – university of notre dame, usa) pemodelan dan identifikasi rasio kelebihan oksigen pada sistem self-humidified pem fuel cell mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 39-48, 10 ill, 2 tab, 19 ref. salah satu parameter pengoperasian fuel cell adalah rasio kelebihan oksigen yang menggambarkan perbandingan antara jumlah oksigen yang bereaksi dengan jumlah oksigen yang dipasok pada katode fuel cell. rasio kelebihan oksigen penting untuk diperhatikan karena berkaitan dengan keselamatan operasi dan usia penggunaan fuel cell. makalah ini memaparkan teknik penentuan model masukan udara dan perhitungan rasio kelebihan oksigen pada self-humidified pem fuel cell komersial dengan daya keluaran 1 kw. pemodelan dilakukan berdasarkan data hasil pengukuran yang relatif terbatas pada sistem loop terbuka. persamaan rasio kelebihan oksigen kemudian ditentukan dengan menggunakan model pasokan udara. identifikasi loop terbuka dengan model arx dilakukan untuk memperoleh hubungan antara rasio kelebihan oksigen terhadap nilai arus stack dan tegangan motor fan. berdasarkan hasil identifikasi sistem diperoleh bahwa estimasi polinomial linier arx orde 4 menghasilkan tingkat kecocokan 56,26% (loss function = 0,0159; final prediction error (fpe) = 0,0159) dan estimasi model non linier arx orde 2 dengan estimator wavenet 75 unit menghasilkan tingkat kecocokan 84,95% (loss function = 0,0139). untuk kemudahan perancangan sistem kontrol, linearisasi dilakukan pada model non linier arx dan menghasilkan model arx orde 2 dengan tingkat kecocokan 78,18% (loss function 0,0009; fpe 0,0009). journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 x (penulis) kata kunci: pem fuel cell, self-humidified, rasio kelebihan oksigen, identifikasi sistem, model polinomial. arifin nur a, yanuandri putrasari a, iman kartolaksono reksowardojo b (a bidang sarana peralatan transportasi, pusat penelitian tenaga listrik dan mekatronik-lipi, bandung; b laboratorium motor bakar dan sistem propulsi, institut teknologi bandung, bandung) pengaruh penambahan etanol pada solar terhadap motor diesel injeksi langsung mechatronics, electrical power, and vehicular technology, july 2012, vol. 3, no. 1, hal. 49-56, 9 ill, 2 tab, 26 ref. eksperimen dilakukan pada motor diesel dengan sistem injeksi langsung (direct injection). uji prestasi ini dilakukan guna melihat karakteristik prestasi dan emisi motor diesel konvensional terhadap penambahan etanol sebagai bahan bakar suplemen pada solar. uji prestasi dilakukan dengan menempatkan motor uji pada perangkat eddy current dynamometer. konsumsi bahan bakar diukur dengan menggunakan perangkat avl fuel balance sementara untuk pengukuran konsumsi udara digunakan hotwire anemometer. beberapa perangkat uji emisi dipasangkan pada saluran gas buang motor diesel untuk mengukur emisi. beberapa variasi campuran solar dengan etanol diujikan pada penelitian ini. campuran bahan bakar yang diujikan mulai dari solar 100% (d100), penambahan etanol 2,5% (de2,5), 5% (de5), 7,5% (de7,5), dan pada campuran 10% etanol (de10). uji prestasi dilakukan pada 1500 rpm dengan variasi pembebanan mulai dari 0 nm (no load) sampai 60 nm (full load) dengan penambahan beban setiap 10 nm. penambahan 5% etanol dalam solar dapat meningkatkan tekanan rata-rata indikasi ruang bakar sebesar 48% disertai penurunan konsumsi bahan bakar spesifik mencapai 9,5%. pada rasio campuran ini terjadi perbaikan karakteristik emisi gas buang di mana emisi karbon monoksida (co) tereduksi hingga 37 %, emisi hidrokarbon (hc) tereduksi hingga 44%, dan kadar kepekatan emisi gas buang tereduksi hingga 15,9% jika dibandingkan dengan motor diesel yang menggunakan bahan bakar solar murni (d100). (penulis) kata kunci: uji prestasi, pencampur solar, etanol, emisi, motor diesel. asmara yanto a, zainal abidin b (a teknik mesin, fakultas teknologi industri – itp, padang; b teknik mesin, fakultas teknik mesin dan dirgantara – itb, bandung) pengembangan metode pengontrolan eksitasi swept-sine untuk meminimalisasi kesalahan pengukuran frf mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 57-64, 10 ill, 3 tab, 19 ref. eksitasi shaker pada pengukuran frf (fungsi respon frekuensi) dari suatu sistem uji dapat dikontrol dengan sinyal swept-sine yang bersumber dari sebuah generator sinyal dan disebut dengan eksitasi swept-sine. kesalahan magnitudo frf sistem yang diperoleh dari pengukuran frf dengan eksitasi swept-sine bergantung kepada fungsi swept dari sinyal swept-sine. pada makalah ini, sinyal swept-sine dengan fungsi linear swept dan s535 swept telah disimulasikan untuk mengontrol eksitasi swept-sine pada pengukuran frf sistem 1-dk (satu derajat kebebasan). linear swept adalah fungsi swept dari sinyal swept-sine yang sering digunakan pada pengukuran frf dan s535 swept adalah sebuah fungsi swept yang dikembangkan pada makalah ini. berdasarkan hasil simulasi, kesalahan magnitudo frf pada frekuensi resonansi sistem yang diperoleh dari pengukuran frf dengan eksitasi linear sweptsine dapat diminimalisasi dengan mengulang kembali pengukuran frf dengan eksitasi s535 swept-sine. (penulis) kata kunci: frf, swept-sine,linear swept, s535 swept, magnitudo. edy riyanto a, b, c, estiko rijanto b, budi prawara b (a state key laboratory for modification of chemical fibers and polymer materials, china; b research centre for electrical power & mechatronics, indonesian institute of sciences, bandung) review deposisi lapisan tipis untuk peralatan skala nano (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 65-72, 8 ill, 0 tab, 53 ref. atomic layer deposition (ald) adalah teknik penumbuhan lapisan tipis yang menggunakan reaksi kimia jenuh antara gas pendahulu untuk mendapatkan deposisi lapisan skala nano. teknik ini menjadi subyek yang sangat menarik saat ini untuk deposisi lapisan sangat tipis pada berbagai aplikasi seperti mikroelektronik, photovoltaic, dynamic random access memory (dram) dan sistem mikroelektromekanik (mems). dengan menggunakan ald keseragaman dan penglarasan dari lapisan dapat dicapai pada temperatur proses yang rendah. deposisi lapisan dengan teknik ini dapat digunakan pada beragam substrat yang memiliki temperatur leleh yang rendah. keuntungan dari ald adalah teknik deposisi ini memiliki kontribusi yang luas untuk aplikasi peralatan skala nano (penulis) kata kunci: lapisan tipis, atomic layer deposition, peralatan skala nano. agus risdiyanto a, b, noviadi arief rachman b, maulana arifin b (a sekolah teknik elektro dan informatika, institut teknologi bandung, bandung; b pusat penelitian tenaga listrik dan mekatronik – lipi, bandung) pengaruh tekanan kontak terhadap nilai tahanan kontak dan perubahan temperatur pada sambungan busbar tembaga mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 73-80, 11 ill, 2 tab, 12 ref. paper ini membahas pengaruh kekencangan atau tekanan kontak pada sambungan busbar tembaga untuk mengetahui perubahan nilai tahanan kontak awal dan temperatur maksimum pada sambungan akibat pembebanan arus yang tinggi. sampel uji menggunakan busbar tembaga ukuran 3 x 30 mm untuk konfigurasi sambungan tumpang tindih dengan baut tunggal. peningkatan tekanan kontak pada sambungan diukur untuk mengetahui pengaruhnya terhadap nilai tahanan kontak. besarnya tekanan kontak yang diterapkan adalah 6 sampai 36 mpa. prosedur pengukuran tahanan kontak mengacu pada standar astm b539 menggunakan metode empat kawat. selanjutnya sampel dibebani dengan arus 350 a selama 60 menit kemudian diukur temperatur maksimum pada masing-masing tekanan kontak. hasil pengujian menunjukkan bahwa nilai tahanan kontak pada sambungan busbar akan semakin kecil dengan meningkatnya tekanan kontak.. peningkatan tekanan kontak journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xi dari 6 sampai 30 mpa menurunkan nilai tekanan kontak dari 16 micro ohm sampai 11 micro ohm. peningkatan tekanan kontak pada tekanan lebih dari 30 mpa tidak menyebabkan kenaikan tahanan kontak secara signifikan. temperatur terendah sambungan busbar adalah 54°c dan dicapai pada tekanan kontak 36 mpa. (penulis) kata kunci: tekanan kontak, tahanan kontak, temperatur maksimum, sambungan busbar tembaga. arini wresta a, b, wiratni budhijanto a (a laboratory of food and bioprocess engineering, chemical engineering department, faculty of engineering, gadjah mada university, yogyakarta; b research centre for electrical power and mechatronics-indonesian institute of sciences, bandung) pengaruh penambahan effluent digester aktif untuk mempercepat start-up peruraian anaerobik air limbah industri tahu (riset dasar pembangkit listrik tenaga biogas) (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 81-86, 2 ill, 0 tab, 17 ref. untuk memperluas aplikasi proses peruraian anaerobik, telah dilakukan proses pembuatan biogas skala laboratorium dengan substrat air limbah industri tahu. masalah yang dihadapi adalah sedikitnya bakteri-bakteri anaerobik di dalam air limbah tersebut. oleh karena itu, untuk mempercepat start-up pembuatan biogas diperlukan starter yang banyak mengandung bakteri-bakteri anaerobik. penelitian ini bertujuan untuk menguji pengaruh penambahan effluent digester aktif sebagai starter pada peruraian anaerobik air limbah tahu. penelitian dilakukan dalam dua buah digester batch berisi 600 gram bahan baku, dimana digester pertama berisi air limbah tahu saja dan digester ke-2 berisi air limbah tahu dan starter effluent digester kotoran sapi aktif yang sangat kaya akan konsorsium bakteri-bakteri anaerobik. hasil percobaan menunjukkan bahwa air limbah tahu mengandung bakteri asidogen tetapi tidak mengandung bakteri metanogen. penambahan effluent digester aktif sebagai starter mempercepat star-up peruraian anaerobik dan mengarahkan jalannya proses ke metanogenesis sehingga diperoleh produk akhir berupa metana. kadar metana yang dihasilkan mencapai di atas 64% sehingga sangat potensial untuk pembangkit listrik. energi listrik sebesar 8,4 kwh dapat dibangkitkan dari industri tahu dengan kapasitas 697,13 kg kedelai per hari. (penulis) kata kunci: effluent digester aktif, start-up, peruraian anaerobik, air limbah tahu, bakteri anaerobik, metanogenesis, energi listrik. hilman s. alam a, pudji irasari b, and dyah kusuma dewi c (a technical implementation unit for instrumentation development, indonesian institute of sciences, bandung; b research center for electrical power and mechatronics, indonesian institute of sciences, bandung; c directorate of technology for manufacturing industry, agency for assessment and application of technology, serpong) kajian defleksi analitis dan numerik pada struktur generator magnet permanen kecepatan rendah kapasitas 10 kw (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 87-94, 12 ill, 1 tab, 17 ref. studi secara analitis dan numerik mengenai defleksi pada struktur generator magnet permanen (gmp) kecepatan rendah kapasitas 10 kw telah dibahas dalam makalah ini. studi ini dimaksudkan untuk mencegah kegagalan struktur saat prototipe sudah dibuat. analisis numerik dilakukan dengan metode elemen hingga (meh). kerapatan fluks, berat dan suhu komponen merupakan parameter-parameter masukan. defleksi yang diamati adalah gerakan dua komponen utama rotor yaitu rim dan poros, di sini defleksi maksimum yang diizinkan pada celah udara antara rotor dan stator harus berkisar antara 10% sampai 20% dari clearance celah udara atau 0,1000 mm sampai 0,2000 mm. berdasarkan hasil analisis, defleksi total hasil perhitungan analitis adalah 0,0553 mm sedangkan simulasi numerik adalah 0,0314 mm. kedua nilai tersebut memenuhi persyaratan karena masih di bawah defleksi maksimum yang diizinkan. hasil tersebut menunjukkan bahwa struktur generator magnet permanen (rim dan poros) dapat digunakan secara aman. (penulis) kata kunci: generator magnet permanen, elemen hingga, celah udara, defleksi. riza muhida a, b, ahmad firdaus a. zaidi c, afzeri tamsir a, b, rudi irawan b, d (a department of informatics and computer, surya college of education (stkip surya), serpong; b international institute for clean energy and climate change (iicecc), serpong; c school of mechatronics engineering, university malaysia perlis, malaysia; d department of physics, surya college of education (stkip surya), serpong) perancangan konverter dc-ac untuk generator tenaga angin bagi penggunaan perumahan jenis 500w (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 95-102, 10 ill, 2 tab, 24 ref. salah satu sumber energi terbarukan, yaitu tenaga angin memiliki prospek yang bagus di indonesia khususnya di pinggiran pantai dan di pegunungan, dimana energi angin ini memiliki potensi untuk menyediakan listrik di perumahan. agar pengembangan pembangkit listrik tenaga angin ini dapat berkelanjutan, maka penting untuk memproduksi inverter secara lokal. perkembangan teknologi saat ini di bidang konversi elektronika daya dan teknologi tertanam memungkinkan untuk mengintegrasikan antara mikrokontroller dan converter daya. dalam penelitian ini, rangkaian inverter dengan skema kontrol yang sesuai telah dikembangkan. rangkaian yang digunakan telah dipilih untuk pembangkin listrik tenaga angin bagi perumahan dengan besar konversi 500w. dari keluaran generator berupa tegangan ac kemudian diubah ke dc, lalu digunakan konverter dc ke dc untuk meningkatkan tegangan ke nilai nominal tegangan dc yang sesuai untuk penggunaan domestik. konverter dc-ac yang didesain akan mengubah tegangan dc menjadi ac. sinyal siklus yang dibangkitkan oleh mikrokontroller berupa sinusida modulasi lebar pulsa akan mengontrol switch di dalam rangkaian inverter, sinyal siklus ini akan dijadikan referensi oleh inverter untuk menghasilkan bentuk tegangan sinusida sebagai tegangan keluaran dari inverter yang akan digunakan sebagai sumber listrik di perumahan. mengingat kecepatan angin di indonesia selalu berubah maka dikembangkan suatu alat pengetesan dalam skala laboratorium, yaitu suatu rig simulator, kecepatan rig journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xii simulator ini dapat dikontrol untuk menghasilkan kecepatan yang berbeda, rig simulator terdiri dari suatu dc motor yang dihubungkan ke poros generator untuk memutar 500w generator angin, tegangan yang dihasilkan oleh generator ini dihubungkan dengan rangkaian konverter dc-ac yang telah dirancang. hasil percobaan menunjukkan bahwa rangkaian konverter ini mampu menghasilkan tegangan keluaran ac sebesar 240v, dan frekuensi 50hz. hasil pengukuran distorsi harmonik keseluruhan sebesar 4% dari tegangan yang dihasilkan ke beban, nilai ini masih memenuhi rekomendasi standard 519-1992 dari ieee. (penulis) kata kunci: energi angin, inverter, konverter, mikrokontroler, generator, perumahan. gerald wahyudi setiono a, prianggada indra tanaya b, henricus riyanto hendradji a (a department of mechatronics engineering, swiss german university, serpong; b department of industrial engineering, swiss german university, serpong) analisis dan pengembangan model kinematik algoritma berjalan untuk 5-derajat kebebasan bipedal robot (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 103-110, 11 ill, 3 tab, 15 ref. makalah ini merupakan pengembangan desain untuk algoritma berjalan dan kalkulasi bipedal robot. dalam hal ini, bipedal robot didesain dan dikonstruksi dengan bagian pinggul, telapak kaki dan beberapa jenis dudukan servo untuk kakinya. setiap kaki terdiri dari 5-derajat kebebasan, 3 pitch (engsel pinggul, lutut dan engkel) dan dua roll (sendi pinggul dan engkel). algoritma berjalan untuk nilai sudut tiap engsel dari bipedal robot ini berdasarkan formula cosinus dan sinus dari segitiga. tinggi hip, tinggi kaki yang diayun dan jarak tempuh melangkah diturunkan berdasarkan persamaan linear. makalah ini akan mendiskusikan analisis model kinematik dan pengembangan diagram berjalan dari bipedal robot. persamaan kinematika diturunkan, sudutsudut joint disimulasikan dan diubah kedalam kode program untuk dieksekusikan pada robot, menggunakan arduino board. (penulis) kata kunci: bipedal robot, model kinematik, analisis kinematik, 5-derajat kebebasan, algoritma berjalan. sutisno a, andreas prasetya adi a (a bidang kendali dan telemetri, pusat teknologi roket lapan) perancangan sistem peredam gangguan getaran untuk melindungi beban-guna roket (orig. eng.) mechatronics, electrical power, and vehicular technology, december 2012, vol. 3, no. 2, hal. 111-116, 8 ill, 0 tab, 13 ref. motor roket dapat menimbulkan getaran yang menggetarkan roket beserta isinya. bagian yang rentan mengalami gangguan adalah beban-guna roket. beban-guna ini terdiri dari berbagai peralatan elektronik seperti : transmitter, macam-macam sensor, akselerometer, gyro, embedded controller system, dan lain sebagainya. pada makalah ini disajikan penelitian pengaruh getaran motor roket terhadap beban-guna dan cara mengatasi gangguan tersebut. untuk mengatasi pengaruh gangguan getaran dapat dilakukan dengan menggunakan bahan silicone gel. silicone gel dipilih sebagai bahan isolator karena memiliki faktor redaman spesifik yang relatif tinggi dibandingkan dengan beberapa bahan lain. getaran motor roket disimulasikan menggunakan motor listrik dan diukur menggunakan sensor akselerometer. hasil pengukuran ditampilkan dalam bentuk kurva, yang menunjukkan level getaran pada beberapa bagian benda uji. hasil dari beberapa percobaan dapat digunakan untuk menentukan bahan peredam yang baik untuk mengurangi getaran yang mengganggu instrumen pada beban-guna. (penulis) kata kunci: motor, roket, getaran, beban-guna, silikon. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiii journal of mechatronics, electrical power, and vehicular technology volume 03, 2012 authors index afzeri tamsir, “design of a dc-ac link converter for 500w residential wind generator,” 03(2): 95102 agus hartanto, “direction and policies needed to support hybrid electric car research,” 03(1): 1-8 agus risdiyanto, “effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection,” 03(2): 73-80 ahmad firdaus a. zaidi, “design of a dc-ac link converter for 500w residential wind generator,” 03(2): 95-102 amin, “design and implementation of anti-windup pi control on dc-dc bidirectional converter for hybrid vehicle applications,” 03(1): 31-38 andreas prasetya adi, “the effect of ethanol-diesel blends on the performance of a direct injection diesel engine,” 03(2): 111-116 arifin nur, “the effect of ethanol-diesel blends on the performance of a direct injection diesel engine,” 03(1): 49-56 arini wresta, “the effect of the addition of active digester effluent for start-up accelerator in anaerobic digestion of soybean curd industry waste water (basic research for biogas power generation),” 03(2): 81-86 asmara yanto, “development of swept-sine excitation control method to minimize the frf measurement error,” 03(2): 57-64 budi prawara, “a review of atomic layer deposition for nanoscale devices,” 03(2): 65-72 dyah kusuma dewi, “analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator,” 03(2): 87-94 edi leksono, “modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system,” 03(1): 39-48 edy riyanto, “a review of atomic layer deposition for nanoscale devices,” 03(2): 65-72 estiko rijanto, “a review of atomic layer deposition for nanoscale devices,” 03(2): 65-72 estiko rijanto, “analysis of inverse angle method for controlling two degree of freedom manipulator,” 03(1): 9-16 gerald wahyudi setiono, “analysis and development of walking algorithm kinematic model for 5degree of freedom bipedal robot,” 03(2): 103-110 hendri maja saputra, “analysis of inverse angle method for controlling two degree of freedom manipulator,” 03(1): 9-16 henricus riyanto hendradji, “analysis and development of walking algorithm kinematic model for 5degree of freedom bipedal robot,” 03(2): 103-110 hilman s. alam, “analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator,” 03(2): 87-94 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xiv hilman s. alam, “magnetic simulation and analysis of radial flux permanent magnet generator using finite element method,” 03(1): 23-30 iman kartolaksono reksowardojo, “the effect of ethanol-diesel blends on the performance of a direct injection diesel engine,” 03(1): 49-56 justin pradipta, “modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system,” 03(1): 39-48 kristian ismail, “development of discrete power supply with charge pump method for high powered sonar system,” 03(1): 17-22 maulana arifin, “effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection,” 03(2): 73-80 muh. zakiyullah romdlony, “design and implementation of anti-windup pi control on dc-dc bidirectional converter for hybrid vehicle applications,” 03(1): 31-38 muhammad kasim, “magnetic simulation and analysis of radial flux permanent magnet generator using finite element method,” 03(1): 23-30 noviadi arief rachman, “effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection,” 03(2): 73-80 prianggada indra tanaya, “analysis and development of walking algorithm kinematic model for 5degree of freedom bipedal robot,” 03(2): 103-110 pudji irasari, “analytical and numerical deflection study on the structure of 10 kw low speed permanent magnet generator,” 03(2): 87-94 pudji irasari, “magnetic simulation and analysis of radial flux permanent magnet generator using finite element method,” 03(1): 23-30 ridwan arief subekti, “direction and policies needed to support hybrid electric car research,” 03(1): 1-8 riza muhida, “design of a dc-ac link converter for 500w residential wind generator,” 03(2): 95102 rudi irawan, “design of a dc-ac link converter for 500w residential wind generator,” 03(2): 95-102 sutisno, “the effect of ethanol-diesel blends on the performance of a direct injection diesel engine,” 03(2): 111-116 syamsu ismail, “development of discrete power supply with charge pump method for high powered sonar system,” 03(1): 17-22 tua agustinus tamba, “modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system,” 03(1): 39-48 vita susanti, “direction and policies needed to support hybrid electric car research,” 03(1): 1-8 wiratni budhijanto, “the effect of the addition of active digester effluent for start-up accelerator in anaerobic digestion of soybean curd industry waste water (basic research for biogas power generation),” 03(2): 81-86 yanuandri putrasari, “the effect of ethanol-diesel blends on the performance of a direct injection diesel engine,” 03(1): 49-56 zainal abidin, “analysis of inverse angle method for controlling two degree of freedom manipulator,” 03(1): 9-16 zainal abidin, “development of swept-sine excitation control method to minimize the frf measurement error,” 03(2): 57-64 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xv journal of mechatronics, electrical power, and vehicular technology volume 03, 2012 affiliation index department of electrical engineering university of notre dame 39 department of informatics and computer, surya college of education (stkip surya) 95 department of industrial engineering, swiss german university (sgu) 103 department of mechatronics engineering, swiss german university (sgu) 103 directorate of technology for manufacturing industry, agency for assessment and application of technology (bppt) 87 international institute for clean energy and climate change (iicecc) 95 laboratory of combustion engine and propulsion system itb 49 laboratory of energy management, engineering physics itb 39 laboratory of food and bioprocess engineering, chemical engineering department, faculty of engineering, gadjah mada university (ugm) 81 mechanical engineering, faculty of industrial technology itp 57 mechanical engineering, faculty of mechanical and aerospace engineering itb 9, 57 national institute of aeronautics and space (lapan) 111 research centre for electrical power and mechatronics lipi 1, 9, 17, 23, 31, 49, 65, 73, 81, 87 research centre for electronics and telecommunication lipi 17 school of electrical engineering and informatics (stei) itb 31 school of mechatronics engineering, university malaysia perlis 95 technical implementation unit for instrumentation development lipi 23, 87 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xvi journal of mechatronics, electrical power, and vehicular technology peer reviewers prof.dr. jamasri mechanical and industrial engineering gajah mada university jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering institut teknologi bandung suhono@stei.itb.ac.id george anwar, ph.d. mechanical engineering, dynamics and controls university of california, berkeley ganwar@integratedmotions.com dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com ir. arko djajadi, ph.d. mechatronics engineering swiss german university arko@sgu.ac.id dr. ahmad agus setiawan renewable energy systems gajah mada university a.setiawan@ugm.ac.id dr. yuliadi erdani information, computer science polteknik manufaktur bandung yul_erdani@polmanbandung.ac.id dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id ir. edi leksono, m.eng. ph.d. physics engineering institut teknologi bandung edi@tf.itb.ac.id dr. irhan febijanto renewable energy development and cdm project the agency for the assesment and application of technology irhan.febijanto@gmail.com dr. endra joelianto engineering physics, instrumentation & control institut teknologi bandung ejoel@tf.itb.ac.id dr. ir. iman kartolaksono reksowardojo mechanical engineering institut teknologi bandung iman@lmbsp.ms.itb.ac.id dr. ir. zainal abidin mechanical engineering institut teknologi bandung za@dynamic.pauir.itb.ac.id riza muhida, ph.d. mechatronics engineering stkip surya riza.muhida@stkipsurya.ac.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id dr. ir. rizqon fajar, m.sc. fuels and lubricant the agency for the assesment and application of technology rizqon66@gmail.com pudji irasari, m.sc.rer.nat. electrical engineering/electric machines indonesian institute of sciences pudji.irasari@lipi.go.id dr.eng. anindito purnowidodo, s.t., m.eng. mechanical engineering brawijaya university anindito@ub.ac.id dr. ir. yoyon ahmudiarto, m.sc., ipm. electrical power engineering indonesian institute of sciences yahmudiarto@yahoo.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 xvii author information writing should be submitted according to these following restrictions: 1. manuscript should be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages a4 including figures and tables, contain no appendix, written using open office text document (.odt) or microsoft word (.doc/.docx) with margin for top, right and bottom is 2cm and 2.5cm for left. 3. title, abstract, and keywords should be written in english and indonesian a. title should be less than 15 words : title case, small caps, centered, bold, font type times new roman (tnr) and single spaced. font size 16 for indonesian title and 14 for english title. b. abstract contains neither pictures nor tables, justified, in 10 tnr and single spaced. the titles are ‘abstract’ (in english) and ‘abstrak’ (in indonesian): justified, bold, in 12 tnr and single spaced. indonesian abstract should not exceed 250 words and english abstract should not exceed 150 words. c. keywords contain three to five words separated with coma, justified, in 10 tnr and single spaced. d. the body of the writing should be in 1 cm spaced two columns, justified, in 11 tnr, and single spaced. 4. manuscript body should be: a. written in two columns, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. b. consist of four main sections: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment (if any) and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 10 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. 8. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 9. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. e. references writing style should be as follows. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 10. detailed writing guidance can be seen in the ‘writing layout manual’ that can be downloaded in journal website. the editorial board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first editorial board mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.65-72 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder dao minh duc a, *, pham dang phuoc a, tran xuan tuy b, le thi thuy tram c a faculty of engineering technology, pham van dong university 509 phan dinh phung street, quang ngai city, viet nam b faculty of mechanical, university of science and technology 41 nguyen luong bang street, lien chieu, da nang city, viet nam c department of electrical and electronics, technological colleges quang nam 224 huynh thuc khang, tam ky city, viet nam received 23 january 2018; received in revised form 2 december 2018; accepted 12 december 2018 published online 30 december 2018 abstract a lower limb rehabilitation device was designed using the compressed air cylinder in order to answer the particular request in viet nam. this paper is presenting the results of a study of the device response. dynamic equation of the actuator and equations of the proportional valve have been established. the relationship between the input signal and the output signal of the actuator was derived. inventor® software was used to design the mechanical structure of the device. matlab® software was used to calculate the parameters values of the pid controller by simulating the response of the actuator. the results show that the response time of both knee drive and hip drive mechanisms are 8 seconds while the overshoot of both knee drive and hip drive mechanisms are 1%. moreover, the starting torque of the knee drive mechanism is 17 nm, and the starting torque of the hip drive mechanism is 35 nm. the simulation results show that the pid controller gives a fast response time and a low overshoot. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: lower limb rehabilitation; hip and knee joint; pneumatic cylinder; pid controller. i. introduction at present, the mechanical engineering industry contributes greatly to the development of society. the products of the mechanical industry are diversified and rich in various fields. in the biomedical field, there are also many products that help the patients and physicians in treating the disease [1]. in the treatment of herniated disc patients with spinal stretch bed, many authors are interested in research, design, manufacture and have achieved certain success [2][3][4]. some studies have applied robots to support rehabilitation for patients with underlying limb disease, helping patients to shorten treatment and helping doctors to monitor the course of treatment for patients [5]. however, in the treatment of patients with hemiplegia due to a cerebrovascular accident in viet nam, at present, there is no automatic device that supports the treatment of equipment for purely mechanical treatment. overseas studies have also been available for the treatment of patients and have also been successful [6][7]. today, compressed air is widely used in industry as well as in social life. the main advantages of compressed air include large capacity, low cost, and ability to be used in harsh environments. these advantages can make the actuator extremely useful in the applications of rehabilitation techniques for stroke or knee pain patients [8][9][10]. the use of compressed air to drive the lower limb rehabilitation device has also been investigated. previous research had used compressed air to control the actuators and produce very promising results [11][12][13]. the request for equipment to support the treatment of patients with hemiplegia caused by accident has been approved by the researchers. this paper has studied the response of an exercise support structure, which evaluates the feasibility of the structure before practical modeling is expected to contribute to patient treatment * corresponding author. tel: +84 905 423 314 e-mail address: dmduc@pdu.edu.vn https://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.65-72 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.65-72&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 66 support. this paper’s aim is studying the use of pneumatic cylinders to drive rehabilitation equipment for the hip and knee joint. the advantage of this solution is to build passive exercises for patients with levels 1 to 3 and active impedance exercises for patients with muscle levels of 3 to 5. combining two active and passive exercises will help the patient shorten the joints rehabilitation time. ii. materials and methods a. the lower limb research model analysis of the lower limb joints including hip joints, knee joints, and ankle joints shows the total degrees of freedom of the lower limb are 9, as shown in figure 1 [14]. however, this paper introduces the degrees of hip and knee arthritis that are commonly used in rehabilitation exercises in hospitals and centers nationwide, as illustrated in figure 2 and figure 3. hip and knee joints are reduced to a two-degree system, and the model is shown in figure 4. b. model of lower limb rehabilitation actuator the functional lower limb rehabilitation actuator model is illustrated in figure 5. its structure consists of two stages with two degrees of freedom around the z axis. stitches are driven by pneumatic cylinders, controlling the cylinders through pneumatic servo valves. c. the dynamic equations of the actuator the dynamic equation of the actuator is expressed by equation (1) and (2).      d q q h q,q g q    (1) n cc ms       (2) where τn is the torque caused by the hip, and thigh muscles τcc and τms are the friction torque components at the robotic stage. because torque components have negligible effects, both components can be ignored and only observing the torque generated by the mechanism. inertial matrix, centrifugal force and coriolis matrix, and gravity force matrix are given as follow. 1) inertial matrix 𝐷(𝑞): 2 2 2 11 1 1 2 1 2 2 1 2 2 1 1 d m l m l l m l l c 3 3           2 2 12 21 2 2 2 1 2 1 2 2 1 d d m l m l m l l c 3     2 22 2 2 1 d m l 3  figure 1. the degrees of freedom of the lower limb figure 2. hip and knee joints in extension state figure 3. hip and knee joints in the contraction state figure 4. lower limb model figure 5. model of rehabilitation lower limb actuator d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 67 2) centrifugal force and coriolis matrix: 2 2 1 2 2 2 2 1 2 1 2 2 2 2 1 2 1 2 1 m l l s m l l s 2 h 1 m l l s 2                     3) gravity force matrix:  1 1 1 1 2 1 1 2 2 1 1 1 1 g m gl c m gl c m gl c 2 2         2 2 2 1 2 1 g m gl c 2    from the above matrix d, h, g, the dynamical equation (1) becomes: 2 2 2 1 1 2 1 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 2 2 2 1 2 1 2 2 1 22 2 2 1 1 m l m l l l l c 3 3 1 m l l m l l c 3 1 m l l l l c 3 1 l m 3                                               2 2 1 2 2 2 2 1 2 1 2 2 2 2 1 2 1 2 1 m l l s m l l s 2 1 m l l s 2                         1 1 1 2 1 1 2 2 1 1 2 2 1 2 1 1 m gl c m gl c m gl c 2 2 1 m gl c 2                      (3) d. design of controller for the actuator figure 6 shows a model of control mechanism at each joint. at each torque joint, the piston's impact force in the cylinder creates the following torque equation: 1 2 f .r.sin            (4) where f is the force generated by the pressure in the cylinders affecting the piston area, r is the rotational radius of the link. force equation in the cylinder is given by (5). f p.a (5) where a is the area of the piston. the valve pressure dependent gas pressure is given by (6). v p k .u (6) from equations (3), (4), (5), and estimating point θ, the equation between torque and voltage can be found as follow [15]. 1 v 2 k .r.a. .u            (7) pid controller was used to examine and evaluate the response of the structure as shown in figure 7. furthermore, equation (1) has been transformed into the equation (8).         1 1 q h q,q g q d q d q       (8) the pid controller is described as follow: t p i d 0 u k e k edt k e   (9) in controlling the actuator, it is necessary to provide the valve opening and closing pressure, from which the pneumatic pressure acts on the piston to produce the torque that controls rotates the rotation at each joint. the rotation angle of the stages are as follows: 1 1d 1 2 2d 2 e e          where θ1d, θ2d are the angles set values of joints 1 and 2. additionally, denoted control voltage can be found as: figure 6. model of control at each joint figure 7. control chart for the actuator d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 68 1 2 u u u        (10) equation (11) can be found by substituting equation (9) into equation (10):     1 1 1 2 2 2 t 1 p 1d 1 i 1 d 1 0 t 2 p 2d 2 i 2 d 2 0 u k k e dt k u k k e dt k                       (11) the define state variable as follows : t 1 1 1 1d 1 0 t 2 2 2 2 d 2 0 x e dt x x e dt x                     (12) equation (13) can be made by substituting equation (12) into equation (10): 1 1 1 2 2 2 1 p 1 i 1 d 1 2 p 2 i 2 d 2 u k x k x k u k x k x k           (13) moreover, substituting equation (12) into equation (6) can emerge equation (14):     1 1 1 2 2 2 v 1 1 1 p 1 i 1 d 1 v 2 2 2 p 2 i 2 d 2 k .r .a . . k x k x k k .r .a . . k x k x k                (14) combining equations (8) and (14) will generate this following equation             1 1 1 2 2 2 1 2 v 1 1 1 p 1 i 1 d 1 v 2 2 2 p 2 i 2 d 2 1 h q,q g g d q k .r .a . . k x k x k1 d q k .r .a . . k x k x k                            iii. results and discussions a. device 3d model after analyzing the dynamics of the lower limb rehabilitation actuator, inventor® software was used to design mechanical structure for the device. a 3d drawing of the device is shown in figure 8. the device supports the patient to practice both feet. the patient is able to sit and lie down for training. at the extension and flexion exercise, the limit angle of the knee is from 0° to 135°. for the hip joint, when the patient is in the sitting position, the limit angle is 0° to 60° in the extension exercise. when the patient is lying down, the limit angle is 0° to 110° at the extension and flexion exercise. b. simulation results this study was using simulink® tool in matlab® to simulate the dynamics of the actuator. the parameter values are selected as follows. 𝐴1 = 0.00524 (𝑚 2); 𝐴2 = 0.002826 (𝑚 2); 𝑙1 = 0.5 (𝑚); 𝑙2 = 0.45 (𝑚); 𝑝 = 4.105 (𝑁/𝑚2); 𝑚1 = 13 (𝑘𝑔); 𝑚2 = 10 (𝑘𝑔); 𝐾𝑣 = 0,0283 (𝑁/𝑚 2. 𝑉); 01 0 02 0 q 2                  ; 1d d 2 d 4 q 4                      𝐾𝑃 = 50; 𝐾𝐼 = 15; 𝐾𝐷 = 5; figure 8. 3d model of the device d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 69 figures 9 to figure 14 show simulated responses of the actuator. analysis and discussion of the simulation results are described as follows. in flexion exercises, the initial values and set point were set using this configuration: the knee joint initial angle was 90°, and the angle set point was 45°, while the hip initial angle was 0° and angle set point was 45°. the following results are obtained: 1) the response time of the knee drive mechanism is 8 seconds, and the response time of the hip drive mechanism is 8 seconds. 2) overshoot of the knee drive mechanism is 1%, and overshoot of the hip drive mechanism is 1%. 3) the starting torque of the knee drive mechanism is 17 nm, and the starting torque of the hip drive mechanism is 35 nm. figure 9. torque response of joint 1 figure 10. torque response of joint 2 figure 11. angle response of joint 1 d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 70 from the simulation results of the actuator at flexion exercise for knee and hip, the error is zero and the overshoot is low. however, the response time is long (approximately 6 to 8 seconds), and the starting torque is quite large. these results are due to the actuator and the human load are quite large. therefore, the high level of torque is very much required to drive the actuator. from this result, the application of pneumatic cylinder can be used for practical experiments. figure 12. angle response of joint 2 figure 13. error angle response of joint 1 figure 14. error angle response of joint 2 d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 71 iv. conclusion in this paper, a dynamic equation for the actuators of a lower limb rehabilitation device was derived, and their responses were simulated using matlab®. in a flexion exercise simulation, initial values, and set points were set as: the knee joint initial angle was 90° and its angle setpoint was 45°, while the hip initial angle was 0° and its angle set point was 45°. the results show that the response time for both knee drive and hip drive mechanisms are 8 seconds while the overshoot of both knee drive and hip drive mechanisms are 1%. moreover, the starting torque of the knee drive mechanism is 17 nm, and the starting torque of the hip drive mechanism is 35 nm. the simulation results show that the response is consistent throughout the training of the patient. in the next step, it would be best to examine the empirical model in order to evaluate the results obtained in theoretical simulation. acknowledgement the authors would like to thank the faculty of the college of technology, the pham van dong university for cooperation and help. references [1] g.z xu, a.g. song, and h.j. li, “system design and control technique of robot aided rehabilitation,” journal of clinical rehabilitation tissue engineering research, vol. 13, pape 714717, 2009. [2] z. li, d. guiraud, d. andreu, a. gelis, c. fattal, and m. hayashibe, “real-time closed-loop functional electrical stimulation control of muscle activation with evoked electromyography feedback for spinal cord injured patients,” international journal of neural systems, vol. 28, no. 06, p. 1750063, aug. 2018. [3] m. o. ibitoye, n. a. hamzaid, m. hayashibe, n. hasnan, and g. m. davis, “restoring prolonged standing via functional electrical stimulation after spinal cord injury: a systematic review of control strategies,” biomedical signal processing and control, vol. 49, pp. 34–47, mar. 2019. [4] y. chen, j. hu, w. wang, l. peng, l. peng, and z.-g. hou, “an fes-assisted training strategy combined with impedance control for a lower limb rehabilitation robot,” in proceeding of 2013 ieee international conference on robotics and biomimetics (robio), 2013, pp. 2037–2042. [5] p. coenen, g. werven, m. nunen, j. dieën, k. gerrits, and t. janssen, “robot-assisted walking vs overground walking in stroke patients: an evaluation of muscle activity,” journal of rehabilitation medicine, vol. 44, no. 4, pp. 331–337, 2012. [6] h. wang, d. zhang, h. lu, y. feng, p. xu, r.-v. mihai, and l. vladareanu, “active training research of a lower limb rehabilitation robot based on constrained trajectory,” in proceeding of 2015 international conference on advanced mechatronic systems (icamechs), 2015, pp. 24–29. [7] t. khoo and s. senanayake, “intelligent musculosoccer simulator,” in the impact of technology on sport ii, taylor & francis, 2007. [8] f. molteni, g. gasperini, g. cannaviello, and e. guanziroli, “exoskeleton and end-effector robots for upper and lower limbs rehabilitation: narrative review,” pm&r, vol. 10, no. 9, pp. s174–s188, sep. 2018. [9] r. r. torrealba, s. b. udelman, and e. d. fonseca-rojas, “design of variable impedance actuator for knee joint of a portable human gait rehabilitation exoskeleton,” mechanism and machine theory, vol. 116, pp. 248–261, oct. 2017. [10] g. chen, p. qi, z. guo, and h. yu, “mechanical design and evaluation of a compact portable knee–ankle–foot robot for gait rehabilitation,” mechanism and machine theory, vol. 103, pp. 51–64, sep. 2016. [11] j. f. veneman, r. kruidhof, e. e. g. hekman, r. ekkelenkamp, e. h. f. van asseldonk, and h. van der kooij, “design and evaluation of the lopes exoskeleton robot for interactive gait rehabilitation,” ieee transactions on neural systems and rehabilitation engineering, vol. 15, no. 3, pp. 379–386, sep. 2007. [12] c. l. lynch and m. r. popovic, “a comparison of closed-loop control algorithms for regulating electrically stimulated knee movements in individuals with spinal cord injury,” ieee transactions on neural systems and rehabilitation engineering, vol. 20, no. 4, pp. 539–548, july 2012. [13] h. yu, m. s. cruz, gong chen, sunan huang, c. zhu, e. chew, yee sien ng, and n. v. thakor, “mechanical design of a portable knee-ankle-foot robot,” in 2013 proceeding of ieee international conference on robotics and automation, 2013, pp. 2183–2188. [14] s. liu and j. e. bobrow, “an analysis of a pneumatic servo system and its application to a computer-controlled robot,” journal of dynamic systems, measurement, and control, vol. 110, no. 3, p. 228, 1988.. [15] h. s. nam, s. koh, y. j. kim, j. beom, w. h. lee, s.-u. lee, and s. kim, “biomechanical reactions of exoskeleton neurorehabilitation robots in spastic elbows and wrists,” ieee transactions on neural systems and rehabilitation engineering, vol. 25, no. 11, pp. 2196–2203, nov. 2017. https://www.researchgate.net/publication/290492052_system_design_and_control_technique_of_robot-aided_rehabilitation https://www.researchgate.net/publication/290492052_system_design_and_control_technique_of_robot-aided_rehabilitation https://www.researchgate.net/publication/290492052_system_design_and_control_technique_of_robot-aided_rehabilitation https://www.researchgate.net/publication/290492052_system_design_and_control_technique_of_robot-aided_rehabilitation https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1142/s0129065717500630 https://doi.org/10.1016/j.bspc.2018.11.006 https://doi.org/10.1016/j.bspc.2018.11.006 https://doi.org/10.1016/j.bspc.2018.11.006 https://doi.org/10.1016/j.bspc.2018.11.006 https://doi.org/10.1016/j.bspc.2018.11.006 https://doi.org/10.1109/robio.2013.6739769 https://doi.org/10.1109/robio.2013.6739769 https://doi.org/10.1109/robio.2013.6739769 https://doi.org/10.1109/robio.2013.6739769 https://doi.org/10.1109/robio.2013.6739769 https://doi.org/10.2340/16501977-0954 https://doi.org/10.2340/16501977-0954 https://doi.org/10.2340/16501977-0954 https://doi.org/10.2340/16501977-0954 https://doi.org/10.1109/icamechs.2015.7287123 https://doi.org/10.1109/icamechs.2015.7287123 https://doi.org/10.1109/icamechs.2015.7287123 https://doi.org/10.1109/icamechs.2015.7287123 https://doi.org/10.1109/icamechs.2015.7287123 https://doi.org/10.1201/9781439828427.ch59 https://doi.org/10.1201/9781439828427.ch59 https://doi.org/10.1201/9781439828427.ch59 https://doi.org/10.1016/j.pmrj.2018.06.005 https://doi.org/10.1016/j.pmrj.2018.06.005 https://doi.org/10.1016/j.pmrj.2018.06.005 https://doi.org/10.1016/j.pmrj.2018.06.005 https://doi.org/10.1016/j.mechmachtheory.2017.05.024 https://doi.org/10.1016/j.mechmachtheory.2017.05.024 https://doi.org/10.1016/j.mechmachtheory.2017.05.024 https://doi.org/10.1016/j.mechmachtheory.2017.05.024 https://doi.org/10.1016/j.mechmachtheory.2016.04.012 https://doi.org/10.1016/j.mechmachtheory.2016.04.012 https://doi.org/10.1016/j.mechmachtheory.2016.04.012 https://doi.org/10.1016/j.mechmachtheory.2016.04.012 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2007.903919 https://doi.org/10.1109/tnsre.2012.2185065 https://doi.org/10.1109/tnsre.2012.2185065 https://doi.org/10.1109/tnsre.2012.2185065 https://doi.org/10.1109/tnsre.2012.2185065 https://doi.org/10.1109/tnsre.2012.2185065 https://doi.org/10.1109/icra.2013.6630870 https://doi.org/10.1109/icra.2013.6630870 https://doi.org/10.1109/icra.2013.6630870 https://doi.org/10.1109/icra.2013.6630870 https://doi.org/10.1109/icra.2013.6630870 https://doi.org/10.1115/1.3152676 https://doi.org/10.1115/1.3152676 https://doi.org/10.1115/1.3152676 https://doi.org/10.1115/1.3152676 https://doi.org/10.1109/tnsre.2017.2714203 https://doi.org/10.1109/tnsre.2017.2714203 https://doi.org/10.1109/tnsre.2017.2714203 https://doi.org/10.1109/tnsre.2017.2714203 https://doi.org/10.1109/tnsre.2017.2714203 d.m. duc et al. / mechatronics, electrical power, and vehicular technology 9 (2018) 65–72 72 this page is intentionally left blank mev j. mechatron. electr. power veh. technol 07 (2016) 105-112 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.105-112. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator hendri maja saputra *, midriem mirdanies, estiko rijanto research center for electrical power and mechatronics, indonesian institute of sciences, komplek lipi, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia received 28 october 2016; received in revised form 14 november 2016; accepted 15 november 2016 published online 23 december 2016 abstract analysis of algorithms to determine the accuracy of aiming direction using two inverse kinematic approaches i.e. geometric and numeric has been done. the best method needs to be specified to precisely and accurately control the aiming direction of a two degrees of freedom (tdof) manipulator. the manipulator degrees of freedom are azimuth (az) and elevation (el) angles. a program has been made using c language to implement the algorithm. analysis of the two algorithms was done using statistical approach and circular error probable (cep). the research proves that accuracy percentage of numerical method is better than geometrical method, those are 98.63% and 98.55%, respectively. based on the experiment results, the numerical approach is the right algorithm to be applied in the tdof robot manipulator. keywords: azimuth; elevation; geometrical; numerical; c language. i. introduction two degrees of freedom (tdof) manipulator is a device that makes a modern instrument more convenient to be operated. modern tdof robot manipulator has been equipped with object detection and identifies features using certain sensors, such as acoustic sensors and visual sensors. in the study conducted by mirdanies [1], object detection and identification was performed using kinecttm camera with sift and surf methods. visual sensors and algorithm are used to convert the coordinates of the target to the aiming direction which is the key to this technology. the algorithm will determine the accuracy and precision of the tdof manipulator aiming direction. the formula of this algorithm is closely associated with the forward and inverse kinematic as in the science of robotics [2]. inverse kinematic can be completed with two common approaches, i.e. geometrical and numerical [3, 4] approaches. robotic or mechatronic systems that use high-speed processing devices can use the numerical approach through an iterative process of jacobian matrix for the inverse kinematic solution [5, 6]. research on inverse kinematic via geometrical and numerical approach has been done by feng [7] for puma 560, but the accuracy and precision issues are not discussed in detail. especially for inverse kinematic via numerical approach, tchon [8] has applied it to the stationary manipulators and mobile robots. in the numerical approach undertaken by soch [9], the extended jacobian technique has been compared with the inverse jacobian. kinecttm is used as a visual sensor in this study. it is placed on a fixed base so that coordinate transformation from a position of the manipulator is to be derived using the denavit-hartenberg (dh) notation [2]. this study aims to analyze the effect of using geometrical and numerical approaches to the accuracy and precision of a tdof robot manipulator aiming direction. ii. homogeneous transformation matrix figure 1 illustrates coordinates system of the camera, the tdof manipulator, and the pointed * corresponding author.tel: +62 8138 1006 059 e-mail: hend018@lipi.go.id http://dx.doi.org/10.14203/j.mev.2016.v7.105-112 h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 106 direction of a specific target. homogeneous transformation matrix of the camera can be written in the form of zyx euler representation ( rα,β,γb a ) in combination with the translational vector [2]. assuming that there is no change in orientation ( α = β = γ = 0 ) and there is only translation along the x-axis (∆x), y-axis (-∆y ), and z-axis ( ∆z ) the homogeneous camera transformation tc can be written as equation (1). 𝑇𝑇𝐶 = � 1 0 0 ∆x 0 1 0 −∆y 0 0 1 ∆z 0 0 0 1 � (1) based on direct measurements in the mechanism, it is known that ∆x value is 26.5 cm, ∆y is 1.25 cm, and ∆z is 0 cm. the tdof robot manipulator parameters in the dh notation [2] can be seen in table 1. these parameters are used to calculate the coordinates of each point based on homogeneous transformations in equation (2). the calculation results of each link are shown by equation (3) and equation (4). homogeneous transformation matrix of the manipulator from the tip relative to the base coordinates can be seen in equation (5). 𝑇𝑇𝑚𝑖 𝑖−1 = � 𝑐 𝜃𝑖 −𝑠 𝜃𝑖 𝑐 𝛼𝑖 𝑠 𝜃𝑖 𝑠 𝛼𝑖 𝑎𝑖 𝑐 𝜃𝑖 𝑠 𝜃𝑖 𝑐 𝜃𝑖 𝑐 𝛼𝑖 −𝑐 𝜃𝑖 𝑠 𝛼𝑖 𝑎𝑖 𝑠 𝜃𝑖 0 𝑠 𝛼𝑖 𝑐 𝛼𝑖 𝑑𝑑𝑖 0 0 0 1 �(2) 𝑇𝑇𝑚1 0 = � 𝑐 𝜃1 0 𝑠 𝜃1 0 𝑠 𝜃1 0 −𝑐 𝜃1 0 0 1 0 𝑑𝑑1 0 0 0 1 � (2) 𝑇𝑇21 𝑚 = � 𝑐 𝜃2 −𝑠 𝜃2 0 𝑎2 𝑐 𝜃2 𝑠 𝜃2 𝑐 𝜃2 0 𝑎2 𝑠 𝜃2 0 0 1 0 0 0 0 1 � (3) 𝑇𝑇𝑚2 0 = � 𝑐 𝜃1 𝑐 𝜃2 −𝑐 𝜃1 𝑠 𝜃2 𝑠 𝜃1 𝑎2 𝑐 𝜃1 𝑐 𝜃2 𝑠 𝜃1 𝑐 𝜃2 −𝑠 𝜃1 𝑠 𝜃2 −𝑐 𝜃1 𝑎2 𝑠 𝜃1 𝑐 𝜃2 𝑠 𝜃2 𝑐 𝜃2 0 𝑑𝑑1 + 𝑎2 𝑠 𝜃2 0 0 0 1 � (4) where 𝑠 𝜃1 = sin 𝜃1 , 𝑐 𝜃1 = cos 𝜃1 , 𝑠 𝜃2 = sin 𝜃2 , and 𝑐 𝜃2 = cos 𝜃2. 𝑑𝑑1 represents length of link 1, and 𝑎2 is length of link 2. based on measurements, it is known that d1 is 34.25 cm, whereas 𝑎2 is 40 cm. the targets are assumed to be simply a translation along the x-axis (lx), thus homogeneous transformation matrix of the target referred to the tip of the link 2 can be written as equation (6). 𝑇𝑇𝑇 = � 1 0 0 𝐿𝑥 0 1 0 0 0 0 1 0 0 0 0 1 � (5) the total homogeneous transformation matrix is obtained by multiplying homogeneous transformation matrix of the camera, the manipulator, and the target matrix as follows: 𝑇𝑇 = 𝑇𝑇𝐶 ∗ 𝑇𝑇𝑚2 0 ∗ 𝑇𝑇𝑇 = � 𝑅𝑅 𝑃𝑃 0 1 � (6) where 𝑅𝑅 = � 𝑛𝑥 𝑠𝑥 𝑎𝑥 𝑛𝑦 𝑠𝑦 𝑎𝑦 𝑛𝑧 𝑠𝑧 𝑎𝑧 � = � 𝑐 𝜃1 𝑐 𝜃2 −𝑐 𝜃1 𝑠 𝜃2 𝑠 𝜃1 𝑠 𝜃1 𝑐 𝜃2 −𝑠 𝜃1 𝑠 𝜃2 −𝑐 𝜃1 𝑠 𝜃2 𝑐 𝜃2 0 � (7) z1 target (px, py, pz) d1 camera y1 z0 x0 x1 elevation (θ₂) azimuth (θ₁) y0 a2 δx lx z3 y3 x3 zt yt xt -δy δz = 0 identification & detection [kx, ky, kz] figure 1. coordinates system of camera, tdof manipulator, and target point table 1. tdof robot manipulator parameters link i αi ai di θi 1 π/2 0 d1 θ1 2 0 a2 0 θ2 h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 107 𝑃𝑃 = � (𝑎2 + 𝐿𝑥) 𝑐 𝜃1 𝑐 𝜃2 (𝑎2 + 𝐿𝑥) 𝑠 𝜃1 𝑐 𝜃2 𝑑𝑑1 + (𝑎2 + 𝐿𝑥) 𝑠 𝜃1 � + � ∆𝑥 −∆𝑦 ∆𝑧 � (8) iii. inverse kinematics coordinates system of the camera, as shown in figure 1, the object being detected by the camera is expressed in the camera coordinate system as [kx, ky, kz]. in the camera coordinate system, z-axis forms a straight line between the camera and the object, and kz represents the distance between them in z-axis. therefore, the coordinates of the object in the dh-coordinate system is given by the following equation: 𝑃𝑃𝑑 = � 𝑃𝑃𝑥 𝑃𝑃𝑦 𝑃𝑃𝑧 � = � �𝑘𝑧2 − 𝑘𝑦2 − 𝑘𝑥2 + ∆𝑥 𝑘𝑥 − ∆𝑦 𝑘𝑦 + ∆𝑧 � (9) a. geometrical approach figure 2 illustrates coordinates system which is used to derive inverse kinematics using geometrical approach. from trigonometric formula, the following equations are obtained [3]. � θ1 = tan−1 � py px � θ2 = tan−1 � z r � = tan−1 � pz− 𝑑1 �px 2+py 2 � ⎭ ⎪ ⎬ ⎪ ⎫ (10) where θ1 is a rotation of joint on the horizontal plane which is called azimuth angle, θ2 is a rotation of joint on the vertical plane which is called elevation angle, (px, py, pz) is the target coordinates relative to the manipulator base coordinate, and (d1, a2) is the length of the link 1 and link 2, respectively. the distance l from the second joint to the target can be calculated as follows: 𝐿 = 𝑎2 + 𝐿𝑥 = �p𝑥2 + p𝑦2 + (p𝑧 − 𝑑𝑑1)2 (11) b. numerical approach the algorithm of numerical approach is carried out through iteration process using pseudo-inverse jacobian matrix [1] as figure 3. iv. accuracy measurement in general, imprecise measurement is associated with random errors while the inaccurate measurement is associated with systematic errors. good aiming results will have small systematic and random errors, and vice versa. systematic errors values are expressed by the difference between the average results of the aim with the midpoint of the target value, while the random errors value is determined by the value of the standard deviation from the results of the aim [10]. data can be analyzed under the assumption gaussian (normal) distribution and independent of each other [11]. gaussian is a distribution of data whose characteristics matches a probability density function (pdf) with average (mean) µ and variance σ2. experiment results are data sets of points in the horizontal axis (x) and the vertical axis (y) in a window area generated by a laser pointer. once the impact point distribution has been assumed to be normal and independent in both dimensions, the dispersion of aiming points can be described using the circular error probable (cep) [12, 13, 14, 15]. the cep is often used to measure the level of accuracy in many z0 x0 0 y0 target (px, py, pz) d1 l θ1 θ2 (px, py) z r r a₂ lx figure 2. geometrical approach coordinates h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 108 applications [12]. cep is defined as the radius r of a circle, centered on the target, which includes 50% of the aiming points [13, 15]. estimation of cep is based on means and standard deviations [13]. the use of cep must meet four criteria: independence, normality, circular distribution, and mean point of impact (mpi) at the target. these criteria can be determined based on the general statistical tests. independence and mpi use the student-test, normality using the lillifors test, and circular distribution using the f-test. in the aim results that have sampled the standard deviation of the two coordinate axes, the cep is calculated using equation (13) [12]. 𝐶𝐸𝑃𝑃 = � (0.820𝑘 − 0.007)𝜎𝑠 + 0.675𝜎𝑙 𝑘 < 0.3 0.615𝜎𝑠 + 0.564𝜎𝑙 𝑘 ≥ 0.3 1.177𝜎 𝑘 = 1 � (12) where 𝑘 is 𝜎𝑠/𝜎𝑙 , 𝜎𝑠 is the smaller standard deviation, 𝜎𝑙 is the larger standard deviation, and 𝜎 is 𝜎𝑥 or 𝜎𝑦. in this paper, accuracy e is expressed in the form of a percentage of accuracy level according to equation (14). e % = �1 − 𝛽 𝐴 � × 100% (13) where 𝛽 is radius of systematic error ( 𝛽 = ��̅� + 𝑦�) and a is maximum radius of aiming area. v. experimental set-up the experimental set up is illustrated in figure 4 and its working principle is shown in figure 5. the target trajectory is represented by a linear and sinusoidal line input to produce movement of azimuth and elevation angles. it is given by the following equations: �𝑋𝑖 = 𝑋𝑖−1 + 20, for 20 ≤ 𝑋𝑖 ≤ 640 𝑌𝑖 = 𝐴𝑦 sin�2𝜋𝑓𝑋𝑖 + 𝜙𝑦� + 𝑏 � (14) where xi and xi-1 are horizontal pixels along x-axis, yi is vertical pixel along y-axis, ay is sinusoidal gain, f is frequency, and b is offset. figure 3. numerical approach st art compute distance between second joint to target using eq. 12 com pute hom ogeneous transformat ion td at default posit ion (θ₁=0 and θ₂=0) using eq. 7-9. td consists of rotat ion matrix rd and translation m atrix pd compute j(e, θ) for the current pose θ: create homogenous transformation matrix at current pose θ using eq. 7-9, convert a transform difference to differential representation: com pute m anipul ator jacobian j = [j1 j2] in end-effector frame wi th init ial ization: a₂ = l and u3 is i denti ty matri x while (θno rm> accuracy) for i = 2:1 compute manipulator jacobian in world coordinates com pute pseudo-invers e j-1 com pute change in joi nt dofs: δθ= j-1 · e apply change to dofs: θ= θ + δθ norm ali zation: θn orm = norm(θ) number i teration: i ++ fi nish if (i > lim it) display error message and abort functi on initialization before iteration lim it = 5000; i=0;accuracy = 1e-12; θnor m =1; θ = [0 0]; yes no loop yes no loop yes no ui = 𝑇𝑇𝑖𝑖 𝑖𝑖−1 𝑚𝑚 ui+1 ji = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ −ui (1,1) ui (2,4) + ui (2,1) ui (1,4) −ui (1,2) ui (2,4) + ui (2,2) ui (1,4) −ui (1,3) ui (2,4) + ui (2,3) ui (1,4) ui (3,1) ui (3,2) ui (3,3) ⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ j = � 𝑅𝑅 zeros(3,3) zeros(3,3) r � j 𝐞𝐞 = � pd − 𝑃𝑃𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 1 2 ��nloop × n𝑑𝑑� + �sloop × s𝑑𝑑� + �a𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 × ad�� � elevation rotation azimuth rotation laser pointer point camera window area 0 640 pixel 480 pixel 0 figure 4. experimental set-up. the heading direction is represented by a laser pointer on the window area (640x480 pixel) to be captured by the camera h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 109 the trajectory pixel data input is converted by the camera into trajectory coordinates (x,y). the azimuth and elevation angles of the tdof manipulator are computed using inverse kinematic and then the robot is driven by the motors so that the heading direction of the tip pin points to the trajectory coordinates by a laser pointer. the laser point (object) coordinates (x,y) and its distance is read by the camera. the trajectory pixel data output is compared with the trajectory pixel data input, figure 6 plots the trajectory data input (kx, ky, kz). in practice, the microcontroller receives decimal values corresponding to the reference angle values from the host computer. in the experimental set up the following unit conversion holds: 1 pixel = 0.00176 cm = 0.00172 rad = 0.0984 deg. the resolution of the input-output signal is 10 bits. from calibration through direct measurement, the relationship between angle and decimal value is given as follows: 𝐷𝑎𝑧 = −0.0002𝜃13 + −0.0001𝜃12 + 1.1492𝜃1 + 524.36 (15) 𝐷𝑒𝑙 = −0.0004𝜃22 + 3.9254𝜃2 + 530.08 (16) where daz is a decimal value to enable azimuth rotation pulse, and del is a decimal value to enable elevation rotation pulse. the default position (0,0) of the tdof manipulator in decimal is 526 (azimuth) and 530 (elevation). vi. result and analysis a computer code has been made using c language to implement the algorithm. figure 7 shows experiment results of aiming direction driver bldc microcontroller pwm pin i/o θ (t) θᵣ (t) computer (kx, ky, kz) window area laser pointer kinect camera trajectory coordinates (a) pixel at (x and y) axis (eq. 14-15) cartesi an coordinate (x, y, z) axis compute inverse kinematics: geometri cal approach numerical approach driver m otor tdof pixel at (x and y) axis (read laser pointer point via camera) laser pointer trajectory input (pixel) trajectory outpu t (pixel) coordinate (cm) angle (degree) pulsa (decimal code) window area data comparis on (b) figure 5. the working principle of experiment: (a) hardware set-up; (b) information flow figure 6. isometric view of trajectory input figure 7. experiment results 0 100 200 300 400 500 600 0 50 100 150 200 250 300 350 400 450 horizontal frame (pixel) ve rti ca l f ra m e (p ix el ) target geometrical numerical h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 110 with 28 pieces of target coordinates. the solid black line is the reference target coordinates generated by equation (18), the broken red line is output coordinates using geometrical approach, and the solid blue line is the output coordinate using numerical approach. performance indicators of the error signal, i.e. average value (μ) and standard deviation (σ), are listed in table 2. processing time consumed by the host computer during the experiment was also recorded, and shown in figure 8. the maximum processing time required to calculate the inverse kinematic is 0.7 µs for geometrical approach and 139.0 µs for the numerical approach. average processing times of geometrical and numerical approaches are 0.4 µs and 108.4 µs, respectively. it can be said that the processing time of the numerical approach is 250 times longer than the geometrical approach. the experiment result has been further analized in the form of aiming error as shown in figure 9. from figure 9, it can be seen that the results of the aiming fall into the scope of the field tested, in other words, it has high accuracy and precision. by substituting performance indicator values in table 2 into equation 17, relative accuracy percentage is obtained which is 98.55% for geometrical approach and 98.63% for the numerical approach. the experiment results were also analyzed statistically. table 3 shows the details of statistical tests and values from cep test data. it gives confidence level of 90% (α = 0.1). the statistical tests show generally good results. special to the mpi test at the target, the population distribution at x axis produces critical t < t statistical which means it rejects the null hypothesis. however, since p-value > 0.1 (90%), this does not provide evidence to reject the null hypothesis that the mpi is not at the targets. the cep plots can be seen in figure 10. it appears that the cep (50% probable) for the numerical approach is smaller than the geometrical approach, i.e. 10.27 pixels and 9.79 pixels, respectively. figure 8. processing time during experiment zoom + geometrical x numerical frame target horizontal error (pix el) ve rt ic al e rr or (p ix el ) figure 9. aiming error table 2. performance indicators of error signal parameter geometrical numerical x y x y mean, µ 3.50 -0.11 3.32 0.29 deviation standard, σ 8.28 9.17 8.09 8.54 count, n 28.00 28.00 28.00 28.00 degree of freedom, df 27.00 27.00 27.00 27.00 k = σmin/σmax 0.90 0.95 table 3. cep statistical test details cep results at (α = 0,01) geometrical (pixel) numerical (pixel) az el az el t-test for statistical independence σ2 68.63 84,10 65.41 72.88 �̂�𝑝𝑜𝑜𝑙𝑒𝑑 2 76.36 69.14 df 54.00 54.00 t statistical 1.54 1.37 t critical 1.67 1.67 independent: yes yes lilliefors test for normality t statistical 0.10 0.13 0.1 0.14 t critical 0.15 0.15 bivariate normal: yes yes t-test for mpi at target t statistical 2.24 0.06 2.17 0.18 t critical 0.15 0.15 mpi at the target: no yes no yes p-value 0.98 0.52 0.98 0.57 f-test for circular distribution f statistical 0.60 0.78 f critical 1.65 1.65 circular: yes yes cep results cep (about mpi) 10,27 9,79 h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 111 vii. conclusion the research proves that numerical method provides relative accuracy percentage which is better than geometric method, which is equal to 98.63% and 98.55%, respectively. therefore, it can be recommended to implement the numerical algorithm into tdof robot manipulator instead of the geometrical one. acknowledgement this work was supported by the research center for electrical power and mechatronics lipi, indonesia.the authors would like to thank aditya sukma nugraha m.t. who helped in the manufacture of the tdof mechanism. thanks also to dr. maria margaretha suliyanti who guided scientific paper writing. references [1] m. mirdanies, et al., “object recognition system in remote controlled weapon station using sift and surf methods,” mechatronics, electrical power, and vehicular technology, vol. 4, no. 2, pp. 99-108, 2013. [2] j. j. craig, introduction to robotics: mechanics and control. third penyunt., canada: pearson prentice hall, 2005. [3] h. m. saputra, et al., “analysis of inverse angle method for controlling two degree of freedom manipulator,” mechatronics, electrical power, and vehicular technology, vol. 3, no. 1, pp. 9-16, 2012. [4] h. m. saputra, “simulation of 2-dof mechanism control system for satellite communication antennas, ” master thesis, aerospace and mechanical department, institut teknologi bandung (itb), bandung, 2012. [5] h. m. saputra and e. rijanto, “analisis kinematik dan dinamik mekanisme penggerak 2-dof untuk antena bergerak pada komunikasi satelit (kinematic and dynamic analysis of a 2-dof mechanism for mobile satellite communication (satcom) antennas),” teknologi indonesia, vol. 32, pp. 21-29, 2009. [6] a. aristidou and j. lasenby, “inverse kinematics: a review of existing techniques and introduction of a new fast iterative solver,” university of cambridge, technical report cued/f-infeng/tr6322009, 2009. [7] y. feng, et al., “inverse kinematic solution for robot manipulator based on electromagnetism-like and modified dfp algorithms,” acta automatica sinica, vol. 37, no. 1, pp. 74-82, 2011. [8] k. tchon, et al., “approximation of jacobian inverse kinematics algorithms,” int. j. appl. math. comput. sci, vol. 19, no. 4, pp. 519-531, 2009. [9] m. soch and r. lorencz, “solving inverse kinematics–a new approach to the extended jacobian technique,” acta polytechnica, vol. 45, no. 2, pp. 21-26, 2005. [10] r. taufiq, “perancangan penelitian dan analisis data statistika, ” penerbit itb, bandung, 2006. [11] m. c. anderson, “generalize weapon effectiveness modeling,” naval cep_geometrical =10.27 cep_numerical = 9.79 horizontal error (pixel) ve rt ic al e rr or (p ix el ) aiming point figure 10. cep result h.m. saputra et al. / j. mechatron. electr. power veh. technol 07 (2016) 105-112 112 postgraduate school, monterey, california, 2004. [12] t. r. jorris, et al., "design of experiments and analysis examples from usaf test pilot school," us air force t&e days conference nashville, tennessee, pp. 337363, 2010. [13] c. mcmillan and p. mcmillan, "characterizing rifle performance using circular error probable measured via a flatbed scanner," version 1.01 ed: creative commons attribution-noncommercial-no derivative works 3.0 united states license, 2008. [14] y. wang, et al., “comprehensive assessment algorithm for calculating cep of positioning accuracy,” measurement, vol. 47, pp. 255-263, 2014. [15] a. didonato, “computation of the circular error probable (cep) and confidence intervals in bombing test,” dahlgren division naval surface warfare center nswcdd/tr-07/13, dahlgren, virginia, 2007. i. introduction ii. homogeneous transformation matrix iii. inverse kinematics a. geometrical approach b. numerical approach iv. accuracy measurement v. experimental set-up vi. result and analysis vii. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.41-48 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. combustion duration influence on hydrogen-ethanol dual fueled engine emissions: an experimental analysis syed yousufuddin department of mechanical engineering, jubail university college jubail industrial city-31961, saudi arabia received 26 december 2017; received in revised form 17 september 2018; accepted 1 october 2018 published online 30 december 2018 abstract the research presented in this article expresses experimental results of combustion duration effect on a dual fueled engine. in particular, the research was focused on the emissions occurred specifically from a hydrogen-ethanol dual fueled engine. this study was performed on a compression ignition engine that was converted to run and act as a spark ignition engine. this modified engine was fueled by hydrogen–ethanol with various percentage substitutions of hydrogen. the substitution was altered from 20 to 80% at a constant speed of 1500 rpm. the various engine emission characteristics such as co, hydrocarbon, and nox were experimentally determined. this study resulted that at a compression ratio of 11:1 and combustion duration of 25°ca, the best operating conditions of the engine were shown. moreover, the optimum fuel combination was established at 60 to 80% of hydrogen substitution to ethanol. the experimental results also revealed that at 100% load and at compression ratios 7, 9, and 11; the co and hc emissions have decreased while nox increased and followed with the increase in the percentage of hydrogen addition and combustion duration. it was concluded that the retarding combustion duration was preferred for nox emission control in the engine. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: combustion duration; compression ratio; dual fuel engine; alternative fuels; compression ignition; spark timing. i. introduction there are various alternative fuels which have been emerged in the energy sector. among those alternative fuels, hydrogen and alcohol substances are attractively developed due to their practical importance. however, some disadvantages have occurred from the operation with ethanol in order to reduce the power output. this resulted in a misfire which reduces engine performance and wastes the existing fuel. some researches show that mixing hydrogen with ethanol has properly reduced this drawback. while the hydrogen emerges a low ignition energy limit, along with elevated burning speed, the hydrogen-ethanol mixture was coming as an easier substitution to ignite, reduces misfire, and by this means reduces the released emissions [1]. wang c et al. [2] conducted performance and emission studies on a passenger car that run by the hydrogen–gasoline engine. previous experimental results showed that when the engine was started with only hydrogen and fueled with the gasoline, the hydrocarbons (hc) and carbon monoxide (co) emissions content were condensed by 64.1% and 62.1%, respectively. park et al. [3] studied the hydrogen ratio and exhaust gas recirculation (egr), especially on its effect on combustion and emission characteristics of hydrogen and diesel dual-fuel premixed charged compression ignition (pcci) engine. they have found that implementing hydrogen or diesel dual-fuel pcci mode could decrease the hc, co, and nitrogen oxides (nox) emissions. huang et al. [4] studied characteristics on combustion which were implemented on a directinjection spark-ignited engine under lean mixture conditions at various ignition time fueled by hydrogen and natural gas combinations. their research has revealed that the ignition time has affected the emissions, and they found that the hc was decreased while nox was increased by escalating the ignition * corresponding author. tel: +96 659 5920 189 e-mail address: yousufuddins@ucj.edu.sa https://dx.doi.org/10.14203/j.mev.2018.v9.41-48 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.41-48 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.41-48&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 42 timing whereas the co was slightly varied under different ignition timings. moreno et al. [5] conducted the experiments at different speeds and equivalence ratios. for each speed, the ignition time could be preserved independently for its equivalence ratio and blend used. it was observed that at the chosen ignition time, the hydrogen addition to the blend had improved the combustion. moreover, they have found that due to the increase in the combustion temperature of hydrogen, the nox emissions at stoichiometric conditions were higher. hamdan et al. [6] have studied a compression ignition (ci) engine. the performance and emission characteristics of the ci engine were observed while inducting the hydrogen in its inlet manifold. the exhaust temperature along with nox emissions was determined while varying the ignition time, engine speed, and hydrogen content. the results revealed that for the same diesel mass flow and with hydrogen content increased, the thermal efficiency of the engine has increased. karagoz et al. [7] have evaluated the emission features from a hydrogen supplemented diesel engine. at full loads with hydrogen addition, a great improvement on co, carbon dioxide (co2), and smoke emissions with an increase in nox emissions were found from his experimental studies. teng su et al. [8] have developed a rotary engine which has a provision at the port to inject n-butanol and hydrogen. their main aim was studying the emissions and the combustion characteristics of a rotary engine fueled by hydrogen-blended n-butanol. this research has developed a self-developed hybrid electronic control unit to regulate the injection duration of a mixture of hydrogen and n-butanol. the research has shown that the hc emissions were reduced by 54.5% while the hydrogen volume fraction was increased from 0 to 6.3%. in addition, co2 and co emissions were also reduced with a substantial increase in hydrogen blending fraction. the last result was about nox emissions that found to be increased because of the increasing of the chamber temperature. fanbo meng et al. [9] have studied the emission characteristics of hydrogen and n-butanol fueled engine. the hydrogen addition fractions of 0%, 2.5%, and 5% were used under spark timings of 10°, 15°, 20°, 25°, and 30° crank angle before top dead center ca btdc. the obtained results showed that co and hc emissions were decreased while the nox emissions were increased along with the hydrogen escalation. sridhara reddy et al. [10] have studied the effect of compression ratios (cr) on the performance and the emissions of a diesel-cng dual fuel engine by adding hydrogen fraction as a combustion booster. their results revealed that the addition of hydrogen in cng had given better results than diesel-cng dual fuel operation. yasin karagoz et al. [11] investigated how the hydrogen addition variation affects engine performance, emissions, and combustion characteristics. it was found from their study that with hydrogen induction by 25 and 50% of total charge energy, there was a decrease in smoke emissions with an increase in nitrogen oxides. after increasing the hydrogen content, an increase was observed in hc although the co2 and co gaseous emissions were significantly reduced. this research discusses the effect of combustion duration on emission characteristics such as co, hc, and nox emissions. the research focus was particularly on hydrogen-ethanol dual fuel implementation on three different compression ratios. the compression ratio has been set at 7:1, 9:1, and 11:1. thereafter, experimental studies were conducted to define the effect of combustion duration on the emission characteristics. the main goal was to get an updated understanding on the interaction between combustion duration and emission characteristic. ii. materials and methods a. research engine and experimental setup this work was implementing a single cylinder direct injection diesel engine (figure 1) which was installed using the specifications mentioned in table 1. this engine was converted by changing the diesel fuel system with a carburetor in order to be able to operate in petrol. the carburetor was later attached to the air intake manifold of the engine, and a spark plug was mounted in place of the diesel injector. a suitable provision was provided to admit hydrogen in the inlet manifold [12]. the different spacers were arranged between the cylinder and the cylinder head to vary compression ratio. the compression will be modified from 7 to 11 ratio. the eddy current dynamometer was connected to the engine. a varying timing arrangement is applied to the engine to operate the engine under spark timing. the spark timing could be adjusted by altering this arrangement mechanically [13]. a specific software then analyzes the combustion duration period within various degrees and the rate of the released heat [14]. detail specification of the instruments is described in table 2. the temperature was recorded using k-type thermocouples positioned at several engine points (i.e., inlet, exhaust of the engine, engine head, cooling water inlet, and cooling water outlet). to measure engine exhaust emissions, an advanced avl five-gas analyzer was used. b. research testing the final test was performed to observe the engine emission on finding the effect of combustion duration on the various engine emission characteristics (i.e., co, table 1. engine specifications engine specifications value cylinder diameter 80 mm cylinder capacity 552.64 cc stroke length 110 mm orifice diameter 15 mm rated power 3.7 kw rated speed 1500 rpm ignition source spark plug compression ratio 7:1 to 11:1 combustion chamber disk shaped s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 43 hc, and nox). the tests were directed using three designated compression ratios (7, 9, and 11) and the speed was constantly set at 1500 rpm for each ratio. the set on the throttle was varied while the load was kept persistent at 100% in kw. within this set, the hydrogen and ethanol flow rate were controlled to keep the speed at a constant state. this control process was conducted by adjusting the volume of hydrogen substitutions with a specific increment (20% increment for 0 to 80% hydrogen substitution). moreover, to achieve the best torque, an adjustment was made to the spark timing. iii. results and discussions a. combustion duration effect on hc concentration the decreases of hc concentration on engine exhaust linearly advance the combustion duration. delaying combustion duration shall increase the fraction implied on the unburned fuel, and also increase the fraction of lean mixture within the combustion chamber, and finally decreases the combustion temperature. this matter had triggered a reduction of hc post-flame oxidation especially throughout the expansion stroke. another reason for the decrease in hc emission could be explained based on the surface to volume ratio, which increases as the spark is advanced and this reduces the hc emissions. it is also revealed by figure 2, figure 3, and figure 4 that because time interval reduction from the ending of fuel induction to the beginning of ignition there is a decrease in hc concentration linearly. with the variation of hydrogen percentage substitution from zero to 80%, the percentage reduction in the hc values is 68.2% at cr 7, 72.63% at cr 9, and 77.59% at cr 11, respectively. the effect of the changing on compression ratio from 7:1 to 11:1 for pure ethanol and 80 % of hydrogen substitutions is a reduction of hc by 15.6 and 40.58 % respectively. hc reduction up to 21.26% has figure 1. experimental setup; (1) hydrogen gas cylinder; (2) pressure gauge; (3) flash back arrestor; (4) hydrogen gas flow controller; (5) flame arrestor; (6) air tank; (7) inlet air heating unit; (8) carburetor; (9) fuel (ethanol) tank connected to carburetor; (10) spark plug; (11) variable compression ratio (vcr) engine; (12) eddy current dynamometer; (13) manomater; (14) burrete; (15) speed indicator; (16) current indicator; (17) voltage indicator; (18) temperature indicator; (19) loading unit; (20) piezoelectric sensor; (21) computer interfaced with vcr engine; (22) cable connecting the sensor to computer; (23) calorimeter; (24) exhaust gas analyzer; (25) power supply; (26) control panel table 2. instrumentation specifications particulars specifications uncertainty temperature sensor radix, type rtd ±1.1% radix, thermocouple type “k” measures the temperature of exhaust gases before and after calorimeter. range 0 to 400°c ±0.7% piezo sensors pcb piezotronics ±0.1% load sensor sensortronics ±0.1% exhaust gas analyzer mn-05 multi gas analyser. co % vol ±1.15% o2 % vol ±0.5% nox (ppm) ± 0.1% dynamometer 10000 rpm maximum speed and 12.5 n-m torque speed ±1.2% and torque ±0.5% s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 44 been found as the effect of the variation of the compression ratio from 7:1 to 11:1. this cr alteration was made at the same change in substitution percentage. figure 2 expresses the hc concentration variation within combustion duration at compression ratios 7:1. figure 3 shows the similar variation of hc concentration at compression ratios 9:1. finally, figure 4 indicates the slight reduction when implemented at compression ratios 11:1. b. combustion duration effect on co concentration low co concentration can be seen in figure 5, figure 6, and figure 7 for both ethanol combustion and ethanol–hydrogen dual fuel combustion. this is mainly because of the high diffusivity of hydrogen and reduction in carbon atoms for ethanol combustion and ethanol–hydrogen combustion. figure 2. variation of hc concentration with combustion duration at cr 7:1 figure 3. variation of hc concentration with combustion duration at cr 9:1 figure 4. variation of hc concentration with combustion duration at cr 11:1 30 55 80 105 130 155 180 205 230 9 11 13 15 17 19 21 23 25 27 29 31 h c c o n c e n tr a ti o n ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 30 50 70 90 110 130 150 170 190 9 11 13 15 17 19 21 23 25 27 29 31 h c c o n c e n tr a ti o n ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 20 50 80 110 140 170 9 11 13 15 17 19 21 23 25 27 29 31 h c c o n c e n tr a ti o n ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 45 following the variation of the hydrogen substitution percentage from 0 to 80%, co emissions reduction has occurred by 72.7%, 77.6%, and 79.9% for 7, 9, and 11 compression ratios respectively. it was also found that the reduction of co by 30.4% had been found when the cr was altered from 7:1 to 11:1 at the same substitution percentage. the experimental tests also revealed that at 100% load co concentration reduction happened at those three compression ratios. c. combustion duration effect on nox concentration the nox concentration increases almost exponentially by advancing the combustion duration (figure 8, figure 9, and figure 10). as mentioned, the higher nox emissions at the advanced spark timings for all the hydrogen substitutions to ethanol are due to the higher peak temperatures realized at those timings. the increase of nox as the combustion duration varied from figure 5. variation of co emissions with combustion duration at cr 7:1 figure 6. variation of co emissions with combustion duration at cr 9:1 figure 7. variation of co emissions with combustion duration at cr 11:1 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 9 11 13 15 17 19 21 23 25 27 29 31 c o ( % v o l) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 9 11 13 15 17 19 21 23 25 27 29 31 c o ( % v o l) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 9 11 13 15 17 19 21 23 25 27 29 31 c o ( % v o l) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 46 10 to 30° before top dead center (tdc) of 80 to 0% by volume, and with a 20% hydrogen decrement at cr 7:1 is 11.92, 8.1, 10.94, 12.63, and 13.8% respectively. whereas under similar conditions of operation at compression ratios 9 and 11, the increase of nox for different hydrogen substitutions is found as 23.3, 14.47, 12.31, 18, 8.74%, and 31.33, 18.7, 17, 13.17, 8.62%. thus, it can be seen that by varying the combustion duration from 10 to 30° and compression ratio from 7:1 to 11:1, the minimum increment percentage in nox was around 8.62% at cr of 11:1. the nox levels were found to be higher because of the higher percentages of hydrogen substitutions used in the study. in place of the percentage of hydrogen, an addition was changed from 0 to 80%. it was found that for 7, 9, 11 compression ratios, the nox has increased by 58.62, 59.3, 62.74% respectively at 100% load that might be caused by increasing in chamber temperature [8]. figure 8. variation of nox emissions with combustion duration at cr 7:1 figure 9. variation of nox emissions with combustion duration at cr 9:1 figure 10. variation of nox emissions with combustion duration at cr 11:1 600 710 820 930 1040 1150 9 11 13 15 17 19 21 23 25 27 29 31 n o x ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 500 600 700 800 900 1000 1100 1200 1300 9 11 13 15 17 19 21 23 25 27 29 31 n o x ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen 500 600 700 800 900 1000 1100 1200 1300 1400 9 11 13 15 17 19 21 23 25 27 29 31 n o x ( p p m ) combustion duration, °ca 100% ethanol 20% hydrogen 40% hydrogen 60% hydrogen 80% hydrogen s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 47 as can be seen from figure 8, figure 9, and figure 10, the nox formation is depends on combustion duration. any small changes in combustion duration resulted in a change in nox emissions [15]. therefore, from the results, it is analyzed that the retarding combustion duration is preferred for nox emission. iv. conclusion the increasing of hydrogen substitution and the decreasing in carbon to hydrogen ratio are responsible for co and hc reduction. due to the high diffusivity of hydrogen and reduction in carbon atoms for ethanol combustion and ethanol–hydrogen combustion, the co concentration remains low. the optimum fuel combination and the best operating conditions observed in the present study were 60 to 80% of hydrogen substitution and 11:1 compression ratio. the best combustion duration for emissions reduction was found to be 25°ca. therefore, the result of this research mentioned that the retarding combustion duration was preferred for nox emission control in the engine. however, the engine operating parameters showed an effect on the combustion duration, and therefore, the designer has to consider these parameters carefully. thus it can be conclude that combustion duration is needed to be carefully designed to attain a better performance and emission characteristics of the engine. references [1] s. yousufuddin, s. n. mehdi, and m. masood, “performance and combustion characteristics of a hydrogen−ethanol-fuelled engine,” energy & fuels, vol. 22, no. 5, pp. 3355–3362, sep. 2008. [2] c. ji, s. wang, b. zhang, and x. liu, “emissions performance of a hybrid hydrogen–gasoline engine-powered passenger car under the new european driving cycle,” fuel, vol. 106, pp. 873–875, apr. 2013. [3] h. park, j. kim, and c. bae, “effects of hydrogen ratio and egr on combustion and emissions in a hydrogen/diesel dual-fuel pcci engine,” jsae/sae 2015 international powertrains, fuels & lubricants meeting, 2015. [4] z. huang, j. wang, b. liu, k. zeng, j. yu, and d. jiang, “combustion characteristics of a direct-injection engine fueled with natural gas–hydrogen blends under different ignition timings,” fuel, vol. 86, no. 3, pp. 381–387, feb. 2007. [5] f. moreno, j. arroyo, m. muñoz, and c. monné, “combustion analysis of a spark ignition engine fueled with gaseous blends containing hydrogen,” international journal of hydrogen energy, vol. 37, no. 18, pp. 13564–13573, sep. 2012. [6] m. o. hamdan, m. y. e. selim, s.-a. b. al-omari, and e. elnajjar, “hydrogen supplement co-combustion with diesel in compression ignition engine,” renewable energy, vol. 82, pp. 54–60, oct. 2015. [7] y. karagöz, t. sandalcı, l. yüksek, and a. s. dalkılıç, “engine performance and emission effects of diesel burns enriched by hydrogen on different engine loads,” international journal of hydrogen energy, vol. 40, no. 20, pp. 6702–6713, jun. 2015. [8] t. su, c. ji, s. wang, x. cong, l. shi, and j. yang, “investigation on combustion and emissions characteristics of a hydrogen-blended n-butanol rotary engine,” international journal of hydrogen energy, vol. 42, no. 41, pp. 26142–26151, oct. 2017. [9] f. meng, x. yu, l. he, y. liu, and y. wang, “study on combustion and emission characteristics of a n-butanol engine with hydrogen direct injection under lean burn conditions,” international journal of hydrogen energy, vol. 43, no. 15, pp. 7550–7561, apr. 2018. [10] s. reddy, m. dutta, and k. v. k. reddy, “effect of compression ratio on performance of a hydrogen blended cng-diesel dual fuel engine,” journal of mechanical engineering, vol. 44, no. 2, p. 87, jan. 2015. [11] y. karagöz, t. sandalcı, l. yüksek, a. s. dalkılıç, and s. wongwises, “effect of hydrogen–diesel dual-fuel usage on performance, emissions and diesel combustion in diesel engines,” advances in mechanical engineering, vol. 8, no. 8, p. 168781401666445, aug. 2016. [12] k. s. kumar and r. t. k. raj, “effect of fuel injection timing and elevated intake air temperature on the combustion and emission characteristics of dual fuel operated diesel engine,” procedia engineering, vol. 64, pp. 1191–1198, 2013. [13] v. b. pedrozo, i. may, t. d. m. lanzanova, and h. zhao, “potential of internal egr and throttled operation for low load extension of ethanol–diesel dual-fuel reactivity controlled compression ignition combustion on a heavy-duty engine,” fuel, vol. 179, pp. 391–405, sep. 2016. [14] y. putrasari, a. nur, and a. muharam, “the influence of two cylinder diesel engine modification (idi to di) on its performance and emission,” journal of mechatronics, electrical power, and vehicular technology, vol. 4, no. 1, p. 17, jun. 2013. [15] y. chen, j. ma, b. han, p. zhang, h. hua, h. chen, and x. su, “emissions of automobiles fueled with alternative fuels based on engine technology: a review,” journal of traffic and transportation engineering (english edition), vol. 5, no. 4, pp. 318–334, aug. 2018. https://doi.org/10.1021/ef800309b https://doi.org/10.1021/ef800309b https://doi.org/10.1021/ef800309b https://doi.org/10.1021/ef800309b https://doi.org/10.1016/j.fuel.2013.01.011 https://doi.org/10.1016/j.fuel.2013.01.011 https://doi.org/10.1016/j.fuel.2013.01.011 https://doi.org/10.1016/j.fuel.2013.01.011 https://doi.org/10.4271/2015-01-1815 https://doi.org/10.4271/2015-01-1815 https://doi.org/10.4271/2015-01-1815 https://doi.org/10.4271/2015-01-1815 https://doi.org/10.1016/j.fuel.2006.07.007 https://doi.org/10.1016/j.fuel.2006.07.007 https://doi.org/10.1016/j.fuel.2006.07.007 https://doi.org/10.1016/j.fuel.2006.07.007 https://doi.org/10.1016/j.ijhydene.2012.06.060 https://doi.org/10.1016/j.ijhydene.2012.06.060 https://doi.org/10.1016/j.ijhydene.2012.06.060 https://doi.org/10.1016/j.ijhydene.2012.06.060 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.ijhydene.2015.03.141 https://doi.org/10.1016/j.ijhydene.2015.03.141 https://doi.org/10.1016/j.ijhydene.2015.03.141 https://doi.org/10.1016/j.ijhydene.2015.03.141 https://doi.org/10.1016/j.ijhydene.2017.08.200 https://doi.org/10.1016/j.ijhydene.2017.08.200 https://doi.org/10.1016/j.ijhydene.2017.08.200 https://doi.org/10.1016/j.ijhydene.2017.08.200 https://doi.org/10.1016/j.ijhydene.2017.08.200 https://doi.org/10.1016/j.ijhydene.2018.02.138 https://doi.org/10.1016/j.ijhydene.2018.02.138 https://doi.org/10.1016/j.ijhydene.2018.02.138 https://doi.org/10.1016/j.ijhydene.2018.02.138 https://doi.org/10.1016/j.ijhydene.2018.02.138 http://dx.doi.org/10.3329/jme.v44i2.21431 http://dx.doi.org/10.3329/jme.v44i2.21431 http://dx.doi.org/10.3329/jme.v44i2.21431 http://dx.doi.org/10.3329/jme.v44i2.21431 https://doi.org/10.1177/1687814016664458 https://doi.org/10.1177/1687814016664458 https://doi.org/10.1177/1687814016664458 https://doi.org/10.1177/1687814016664458 https://doi.org/10.1177/1687814016664458 https://doi.org/10.1016/j.proeng.2013.09.198 https://doi.org/10.1016/j.proeng.2013.09.198 https://doi.org/10.1016/j.proeng.2013.09.198 https://doi.org/10.1016/j.proeng.2013.09.198 https://doi.org/10.1016/j.fuel.2016.03.090 https://doi.org/10.1016/j.fuel.2016.03.090 https://doi.org/10.1016/j.fuel.2016.03.090 https://doi.org/10.1016/j.fuel.2016.03.090 https://doi.org/10.1016/j.fuel.2016.03.090 http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 https://doi.org/10.1016/j.jtte.2018.05.001 https://doi.org/10.1016/j.jtte.2018.05.001 https://doi.org/10.1016/j.jtte.2018.05.001 https://doi.org/10.1016/j.jtte.2018.05.001 https://doi.org/10.1016/j.jtte.2018.05.001 s. yousufuddin / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 41–48 48 this page is intentionally left blank mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.1-10 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer hendri novia syamsir a,*, dalila mat said b, yusmar palapa wijaya a a electronics engineering, polytechnic caltex riau, jl. umbansari no 1 rumbai, pekanbaru, riau 28265, indonesia b centre of electrical energy systems (cees), university technology malaysia (utm), johor bahru 81310, malaysia received 10 february 2016; received in revised form 23 december 2016; accepted 26 december 2016 published online 31 july 2017 abstract this paper presents a simple and costs effective equipment design multi-feeder data logger for recording and monitoring power quality. the system design uses remote supervising and multi-feeder data logging system (resmos). the data collected through resmos portable unit (rmpu) will automatically be saved with the format as binary and comma separated value (csv). the time setting on the rmpu can be configured with minimum one minute per logging. this data logger uses a single transducer with a multiplexer for recording and monitoring ten channels of power quality at busbar. the system design has been validated with national metrology laboratory scientific and industrial research institute of malaysia (sirim). this tool has the advantage that it can be used to measure harmonic data more than 21st at the same time for ten channels and equipped with software making it easier for analysis data with low operational costs versus another power quality equipment. the experimental results indicate that the proposed technique can accelerate data reading with conversion rate one sample per second for each channel. the device can be used to measure harmonic level and power quality with a confidence level above 95% and percentage error under 2.43% for total harmonics distortion (thd) and 1.72% for voltage harmonics. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: harmonic; power quality; measurement; data logging; multi-feeder i. introduction traditionally, measurements are taken using a variety of measuring instruments, each of which requires a particular skill for obtaining readings. if the detailed data are needed by a certain time interval, the measurement should be repeated in the interval of time and for a very short time interval, for example, a few seconds, measurement cannot be done manually. in the 1970's and 80's first personal computer was developed, and with the development of the personal computer, people began to use computers for data analysis, data storage, and report generation. the need to bring data into the pc is a new special-purpose device for data logging. this data must be transferred to the pc for analysis, permanent storage, and report generation. data is typically transferred either by manually moving a storage device of the data logger to the computer or by connecting the data logger to the pc through some communications link such as serial port, usb, wireless or ethernet. data logging is the measurement and recording of physical or electrical parameters over a period and used to collect readings, or output, from sensors a data logger is an electronic instrument that records environmental parameters or industrial parameters such as pressure, temperature, relative humidity, solar radiation, wind speed and direction, light intensity, water level, and water quality over time. this instrument is stand-alone, box instruments that measure signals, convert to digital data, and store the data internally. although data loggers are used in many industries from space exploration to oil refining, to drag racing, this research will be focusing on their application for power quality monitoring, especially harmonic. typically, data loggers are compact, battery-powered devices that are equipped with microprocessor input channels and data storage. most data loggers utilize turnkey software on a personal computer to initiate the logger and view the collected * corresponding author. tel: +62 813 6333 3978 e-mail address: hendri.fte@gmail.com https://dx.doi.org/10.14203/j.mev.2017.v8.1-10 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.1-10 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 2 data. data logger is a good option, to gather some data for the future analysis on pc. this study developed the equipment as research product output for recording and monitoring power quality problem using remote supervising techniques and multi-feeder data logging system [1, 2]. the equipment can measure and analyze the power quality problem, particularly harmonic problem measurement and the data can be saved over long test periods and analyzed with appropriate software. we had also developed the software to support practitioners to be easy and understand the analyzing power quality problem measurement. ii. power quality problem and harmonic measurement harmonic problem issue is critical and heavy impacted by power quality problem [3, 4]. it is caused by interferences that have two causes such as loads with non-linear current-voltage-characteristics and non-steady operation. equipment to monitor or record the harmonic is necessary for practitioners in electrical products to know the harmonic problem when they are testing the prototype of electrical products. remote supervising technique is powerful techniques to record measurement of power quality because it can do fundamental measurement such as voltage (r, y, b), current (r, y, b, n), power factors (r, y, b), and also harmonic measurement as secondary measurement such as the voltage total harmonic distortion (r, y, b), the voltage harmonics value for odd harmonics up to 21st harmonic level (r, y, b), and current total harmonic distortion (r, y, b). a monitoring system for recording measurement of a power quality problem can be easy and less cost by using multi-feeder data logging system. this tool only uses a single transducer with a multiplexer to monitor from many feeders and many types of power quality measurement simultaneously. on the other hands, multi-feeder data logging system designed to operate in a harsh environment area which works like a paperless recorder, storing data in memory at a rate which is much longer than the time required for the electrical industry. it is important to understand the type of power quality problem and their measurement. type of power quality problem can be divided into two basic categories i.e. the disturbances and steady state [5, 6]. disturbances are measured by triggering on an abnormally in the voltage or the current. steady state variation has normal rood mean square (rms) voltages or the current and harmonic distortion. measurement of power quality can be described through monitoring quality of voltage, current, power factors, and harmonic distortion [7, 8]. harmonics are electric voltages and currents that appear on the electric power system as a result of certain kinds of electric loads [9, 10]. harmonic frequencies in the power grid are a frequent that cause power quality problems. one of the major effects of power system harmonics is the increasing the current in the system [11]. this is particularly the case for the third harmonic, which causes a sharp increase in the zero sequence current, and therefore, increases the current in the neutral conductor. this effect can require special consideration in the design of an electric system to serve non-linear loads. in addition to the increased line current, different pieces of electrical equipment can suffer effects from harmonics on the power system. effect of harmonics can be divided into two categories i.e. the effect of voltage harmonics and current harmonics [5, 6, 12]. harmonic voltages and currents in an electric power system are a result of non-linear electric loads. harmonic frequencies in the power grid are a frequent cause of power quality problems. harmonics in power systems result in increased heating in the equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors. harmonics in power systems result in increased heating in the equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors. the current of harmonic effect is of significance. these harmonic current components cause additional losses in the windings and other structural parts. for a transformer winding turns which consist of small strands, skin effect or the current redistribution due to internal current is usually assumed to be negligible [13, 14]. there are many measurements employed to describe the harmonic on a power system. this study used three measurements of harmonic i.e. voltage harmonic, current harmonic, and total harmonic distortion for current and voltage. a. voltage total harmonic distortion a pure voltage or current sine wave has no distortion and no harmonics. therefore, voltage total harmonic distortion (vthd) is zero. the nonsinusoidal wave has distortion and harmonics. to quantify the distortion, the vthd as a percentage is used to show how badly a waveform is distorted on a pure sine wave [3, 5]. hence, vthd is defined as below: 𝑉𝑇𝐻𝐷 = √∑ 𝑣ℎ 2∞ ℎ=2 𝑉1 (1) 𝑉𝑟𝑚𝑠 = 𝑉1√1 + 𝑉𝑇𝐻𝐷 2 (2) with 𝑣ℎ is voltage harmonic, 𝑉1is voltage line and 𝑉𝑟𝑚𝑠 is root mean square voltage. b. current total harmonic distortion definition of current total harmonic distortion (ithd) is not relative similar with voltage total harmonic distortion [5, 15]. the current distorted can cause increased losses in the end-user and utility power system components. the effect is a decrease in the power factor and increases reactive power. hence, current total harmonic distortion (ithd) is defined as below: 𝐼𝑇𝐻𝐷 = √∑ 𝐼ℎ 2∞ ℎ=2 𝐼1 (3) 𝐼𝑟𝑚𝑠 = 𝐼1√1 + 𝐼𝑇𝐻𝐷1 2 (4) h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 3 with 𝐼ℎ is current harmonic, 𝐼1is current line, and 𝐼𝑟𝑚𝑠 is root mean square current. c. the total power factor total power factor or true power factor can be calculated by considering the effect of harmonic in the system, as follows: 𝑝𝑓 = ( 𝑃 𝑉1𝐼1 ) ( 1 √(1+𝑉𝑇𝐻𝐷)2(1+𝐼𝑇𝐻𝐷)2 ) (5) in which 𝑝𝑓 is power factor and 𝑃 is power. iii. design consideration for power quality data logger a typical online diagram measurement of a power substation network is shown in figure 1. the portable master unit, three phase line, and current transformer are main components in the typical online diagram measurement of power substation network. l1, l2, l3 are the three line that will be measured, and n is the neutral current. each flow was measured using the current transformer (ct). its compact size – the unit will fit into various types of substations or electrical distribution point for both 1p/3p systems i.e. standard sub, compact and pole mounting substation, feederpillars, and main switchboard cabinets. terminate voltage signal cables that figure the crocodile clip is used tohn measure red voltage (vr), yellow voltage (vy), blue voltage (vb) phase, neutral (n), and earth (e). terminate of voltage crocodile figured should be clipped on the bus bar that has three voltage phases i.e. red, yellow, blue voltage phase, and also in earth (e) and neutral (n). this determination process is actually reversible of the termination process meaning that the operation must determinate neutral n followed by earth e and each phase (vr, vy, vb). after the terminating process completed, the user must switch two cpu switches such as transducer tx and auxiliary aux switch. the rebooting system needed 10-15 seconds, and the system will run default setting of software. the user can change program setting and active channel by connection two rs-232 cables to communication board system and notebook and run the program of terminal communication. most pc or notebook has 2 com port which serial rs232 communication compatible. the commonly use setting to establish a serial rs232 communication is 9600 baud rate, none parity 8 data bits, and 1 stop bit [1, 2]. as this project relates with data collection, thus the data obtained from the transducer needs to be collected and saved. this can be done by using the graphical user interface (gui) monitoring system where it automatically saves the data received in a comma separated values (csv) file. a. motherboard and daughterboard design to reduce the footprint size of the multiplexer, a concept of motherboard and daughterboard is used as shown in figure 2. the figure also illustrates the method of assembly of the system which is by using a stacked implementation approach. 1) double-wide motherboard (dw motherboard) the dw motherboard only allows phase current passing through itself, but the phase voltage is monitored directly by the voltage sensor. the phase current and phase voltage have to pass through the multiplexer before being captured by the transducer. the neutral current can only be monitored if the dw daughterboard is stack in the dw motherboard. 2) double-wide daughterboard (dw daughterboard) the dw daughterboard is designed just to monitor the neutral current to all feeders (2 incoming and 8 outgoing). the daughterboard design concept allows the inclusion of additional relays to enable the monitoring of neutral current to all feeders without having to increase the footprint size of the system unit. the dw daughterboard size is smaller than the dw motherboard because the number (quantity) of the ds2y relays type on the daughterboard is 12 pieces, while dw motherboard has 30 ds2y relays. this board can activate only if it is stacked on the motherboard because the dw motherboard controls the entire channel in the dw daughterboard. l1 l2 l3 n configsys setting download com 1 figure 1. typical online diagram measurement of a substation network h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 4 b. transducer specification the power transducer ct1700 is an instrument that measures, calculates, and displays all main electrical parameters at any electrical network (balanced or not). the measuring is true rms value, through three ac voltage inputs 240v and three ac current inputs (from current transformers 100/5a). it is featured by its high measuring accuracy and easy assembly mode. it can be integrated into a communication network through its built-in-rs232 output by just using modbus standard protocol. c. remote supervising techniques the remote supervising technique is a tool to measure and monitor the power quality in distribution. figure 3 depicted the relationship between remote sensing than the power distribution and power system. remote supervising has three components i.e. portable master unit (rmpu), terminal communicator program and software analyzer system. rmpu equipment is designed as a portable unit for easy handling, transportation, and installation. the function of the transducer ct 1700 is converting the electrical signal to digital signal. the communicator program enables the technician to communicate with the rmpu. it can run on a notebook or desktop pc. analyzer software is a fundamental component that is used to record among measurement of power quality. the analyzer program runs through windows 95/98/xp/win7 operating platform. it maintains the substation database containing monitored data such as line current, line voltage, neutral current, phase angle, power factor, active power, reactive power, apparent power, and substation configuration. computerized electrical load monitoring and data acquisition system for general power industry application divided into three major modules namely display, data record, and software general specifications. 1) display the display form of the data logger is to view the measurement data that are being recorded. the display function can view live data and historical data. live data display to view data as it is being acquired and many stand-alone data loggers have a live data display integrated into the box with them. historical data display data that was previously acquired. most standalone data loggers are required to move data to a pc for historical viewing. with pc-based data logging applications, both live display and historical display are combined into the same user interface. figure 4 shows an example of data displayed the total harmonic distortion for voltage with the available software analyzer, and figure 5 shows the harmonic spectrum for current. figure 6 shows the view on the screen of data logger under dos using c++ direct from rmpu at the offline condition. ds2y relay sw/dw daughterboard 34 pin pg back socket sw/dw motherboard figure 2. stack design motherboard multiplexer pq transducer ( dos,c++) pc windows ( vb 6) data ”csv” format data storage ( cf) “binary” format setting download substation current transducer voltage 3 phase com 1com 2 cpu terminal communicator program and software analyzer system s e n s o r te m p e ra tu re channel 7 8 9 temp1 temp2 temp3 temp4 temp1 temp2 temp3 temp4 temp1 temp2 temp3 temp4 channel 0...6 (ir,iy,ib,in) t e m p e r a tu r e figure 3. remote supervising technique communicator h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 5 2) data record each data collected through rmpu will automatically be formatted both as binary and comma separated value (csv). this csv format is purposely for viewing in microsoft excel. microsoft excel can be used to copy and paste the data operations. the time setting on the rmpu can be configured with set the minimum one minute per logging. software analyzer can take the data from the database while communicator can download the data from rmpu to store and transfer them to the database server. finally, software analyzer will be used to convert data into a database. 3) software general specifications table 1 describes the specification of software general developed that are detailed by description, type of os/rmpu, communication software, and analyzer software. analyzer program supports harmonic data, for instance, vthd, voltage figure 4. graphic view on screen for voltage thd figure 5. graphic view on screen harmonic current table 1. software general developed description operation system communicator development tools borland c++ ms visual basic 6.0 operating platform ms-dos ms windows (95/98/me/xp,win7) site/location substation substation brief functional specifications  control data flow  format the structure of data  log date & time  log voltage (red, yellow, blue)  log current (red, yellow, blue, neutral) log power factor(red, yellow, blue)  allow configuration to be made to rmpu through windows environment  allow data to be stored to a notebook before transferring to end user database  download & save data as 1. csv (*.csv) 2. binary (*.bin) h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 6 harmonics, ithd, and current harmonic. there would be dramatically changed to the database regarding size, the data stored, and the definitions of the table. figure 7 shows the system and data flow diagram. four types of harmonic value identified to be used in software analyzer database are: 1. harmonic current 2. harmonic voltage 3. current thd 4. voltage thd table 2 describes phase, channel (feeder), and level for each harmonic. the total database table for harmonic value is 363, such as the following calculation. the complete calculation of this total database table for harmonic value is expressed in equation (6) to equation (10). thc = 𝑃ℎ𝑎𝑠𝑒 𝑥 𝐶ℎ𝑎𝑛𝑛𝑒𝑙 𝑥 𝐿𝑒𝑣𝑒𝑙 (6) thv = 𝑃ℎ𝑎𝑠𝑒 𝑥 𝐿𝑒𝑣𝑒𝑙 (7) tcthd = 𝑃ℎ𝑎𝑠𝑒 𝑥 𝐶ℎ𝑎𝑛𝑛𝑒𝑙 (8) tvthd = 𝑃ℎ𝑎𝑠𝑒 (9) tdt = 𝑇𝐻𝐶 + 𝑇𝐻𝑉 + 𝑇𝐶𝑇𝐻𝐷 + 𝑇𝑉𝑇𝐻𝐷 (10) where thc is total harmonic current, thv is total harmonic voltage, tcthd is total current thd , tvthd is total voltage thd, and tdt is total database table for harmonic. figure 6. view on screen data logger under dos using c++ direct from rmpu at offline condition analysis particular graph table report feeder analysis particular browser substation summary voltage analysis individual substation group of subtation substation voltage current power factor harmonic particular 1.0 os temporary database data transfer 2.0 terminal communicator data download temporary database data download 3.0 analyzer database data upload & download lan enable voltage current power factor harmonic particular figure 7. system and data flow diagram table 2. total channel, phase, and level for each type of harmonic type of harmonic phase channel (feeder) level harmonic current r, y, b 10 channel 21 (odd level) harmonic voltage r, y, b 21 (odd level) current thd r, y, b 10 channel voltage thd r, y, b h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 7 iv. data logging and result this logger is used to log the harmonic data at three different types of loads which are industrial, residential, and office building. the data was logged for one day with an interval time of one minute. from the formatted data in binary and comma separated value (csv), then the data transfer to excel format. in this format, the spectrum of harmonic and a trend of total harmonic distortion over time was plotted. figure 8, figure 9, and figure 10 show the current harmonic spectrum for the residential, commercial, and industrial building. the total harmonic distortions for residential are 15.02%, 4.77%, and 0.93%, commercial are 3.6%, 3.02%, and 3.52% and industrial are 8.52%, 7.78%, and 7.45% for phase r, y, and b respectively. v. result and discussion table 3 and table 4 describe certificate of calibration national metrology laboratory by sirim malaysia for each phase. refer to statistic calculation it is found that the confidence level meets the requirement of the national standard by sirim. it shows that the data are valid with the confidence level above 95%. this data logger was compared with power quality analyzer fluke 435. the data were taken from three different locations. the comparison data is shown in table 5, table 6, and table 7. figure 11, figure 12, and figure 13 show the graph of percent harmonic current number three for phase r, y, and b respectively. the comparable data sets agree on each other. table 3. certificate of calibration national metrology laboratory by sirim for voltage harmonic fundamental: 50 hz, 240 v harmonic no error (%) *uncertainty ± (%) phase 1 phase 2 phase 3 phase 1 phase 2 phase 3 3 0.24 0.18 0.22 0.14 0.04 0.10 5 -1.07 -1.24 -1.48 0.03 0.11 0.14 7 -0.95 -1.09 -1.82 0.03 0.11 0.14 9 -0.83 -0.02 -1.83 0.03 0.05 0.11 11 -0.71 -1.01 -2.20 0.03 0.14 0.17 13 -0.92 -0.96 -2.60 0.12 0.14 0.18 15 -0.84 -0.86 -2.62 0.2 0.13 0.14 17 -0.72 -0.79 -2.26 0.15 0.17 0.17 19 -0.69 -0.57 -1.71 0.17 0.15 0.15 21 -0.37 -0.5 -0.83 0.15 0.16 0.18 thd 0.12 0.12 -2.33 0.18 0.11 0.19 *coverage factor, k = 2 at 95% confidence level table 4. certificate of calibration national metrology laboratory by sirim for current harmonic fundamental: 50 hz, 5 a harmonic no error (%) *uncertainty ± (%) phase 1 phase 2 phase 3 phase 1 phase 2 phase 3 3 -0.05 -0.05 -0.06 0.08 0.05 0.06 5 -0.05 -0.06 -0.21 0.05 0.08 0.11 7 -0.07 -0.06 -0.80 0.07 0.13 0.09 9 -0.08 -0.16 -1.29 0.09 0.08 0.08 11 -0.08 -0.18 -1.69 0.05 0.06 0.14 13 -0.07 -0.19 -1.72 0.06 0.06 0.06 15 -0.09 -0.16 -1.54 0.21 0.08 0.06 17 -0.12 -0.13 -1.38 0.11 0.08 0.06 19 -0.17 -0.16 -1.07 0.19 0.12 0.11 21 -0.13 -0.14 -1.40 0.18 0.13 0.17 thd -0.31 -0.25 -2.43 0.14 0.12 0.15 *coverage factor, k = 2 at 95% confidence level table 5. harmonic current data of resmos and fluke 435 for case 1 harmonic no resmos fluke 435 ir iy ib ir iy ib 3 1.14 4.7 4.95 1.12 4.65 4.92 5 4.02 3.31 4.27 3.97 3.3 4.25 7 2.39 2.08 3.41 2.37 2.07 3.39 9 0.45 0.91 0.13 0.41 0.89 0.1 h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 8 table 6. harmonic current data of resmos and fluke 435 for case 2 harmonic no. resmos fluke 435 ir iy ib ir iy ib 3 1.45 1.4 1.95 1.44 1.39 1.94 5 0.43 1.81 1.45 0.42 1.79 1.42 7 2.18 2.08 2.73 2.1 2.07 2.67 9 0.88 1.05 1.08 0.86 1.04 1.07 figure 8. current harmonic spectrum for residential load figure 9. current harmonic spectrum for commercial load figure 10. current harmonic spectrum for industrial load 0 2 4 6 8 10 12 ih3 ih5 ih7 ih9 ih11 ih13 ih15 ih17 ih19 ih21 h a r m o n ic c u r r e n t ( % ) harmonic no. ir iy ib 0 0.5 1 1.5 2 2.5 3 3.5 4 ih3 ih5 ih7 ih9 ih11 ih13 ih15 ih17 ih19 ih21 h a r m o n ic c u r r e n t (% ) harmonic no. ir iy ib 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 ih3 ih5 ih7 ih9 ih11 ih13 ih15 ih17 ih19 ih21 h a r m o n ic c u r r e n t (% ) harmonic no. ir iy ib h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 9 table 7. harmonic current data of resmos and fluke 435 for case 3 harmonic no. resmos fluke 435 ir iy ib ir iy ib 3 1.12 1.23 1.28 1.05 1.22 1.25 5 2.89 1.18 1.81 2.8 1.17 1.59 7 4.59 1.48 5.69 4.09 1.46 5.11 9 1.12 1.21 1.38 1.05 1.19 1.24 figure 11. comparison data ih3r resmos and fluke figure 12. comparison data ih3y resmos and fluke figure 13. comparison data ih3b resmos and fluke -0.5 0 0.5 1 1.5 2 2.5 3 1 6 :3 1 :5 2 1 7 :0 2 :5 2 1 7 :3 3 :5 2 1 8 :0 4 :5 2 1 8 :3 5 :5 2 1 9 :0 6 :5 2 1 9 :3 7 :5 2 2 0 :0 8 :5 2 2 0 :3 9 :5 2 2 1 :1 0 :5 2 2 1 :4 1 :5 2 2 2 :1 2 :5 2 2 2 :4 3 :5 2 2 3 :1 4 :5 2 2 3 :4 5 :5 2 0 :1 6 :5 2 0 :4 7 :5 2 1 :1 8 :5 2 1 :4 9 :5 2 2 :2 0 :5 2 2 :5 1 :5 2 3 :2 2 :5 2 3 :5 3 :5 2 4 :2 4 :5 2 4 :5 5 :5 2 5 :2 6 :5 2 5 :5 7 :5 2 6 :2 8 :5 2 6 :5 9 :5 2 7 :3 0 :5 2 8 :0 1 :5 2 8 :3 2 :5 2 9 :0 3 :5 2 9 :3 4 :5 2 1 0 :0 5 :5 2 h a rm o n ic c u rr e n t (% ) time resmos fluke -0.5 0 0.5 1 1.5 2 2.5 3 1 6 :3 1 :5 2 1 6 :5 9 :5 2 1 7 :2 7 :5 2 1 7 :5 5 :5 2 1 8 :2 3 :5 2 1 8 :5 1 :5 2 1 9 :1 9 :5 2 1 9 :4 7 :5 2 2 0 :1 5 :5 2 2 0 :4 3 :5 2 2 1 :1 1 :5 2 2 1 :3 9 :5 2 2 2 :0 7 :5 2 2 2 :3 5 :5 2 2 3 :0 3 :5 2 2 3 :3 1 :5 2 2 3 :5 9 :5 2 0 :2 7 :5 2 0 :5 5 :5 2 1 :2 3 :5 2 1 :5 1 :5 2 2 :1 9 :5 2 2 :4 7 :5 2 3 :1 5 :5 2 3 :4 3 :5 2 4 :1 1 :5 2 4 :3 9 :5 2 5 :0 7 :5 2 5 :3 5 :5 2 6 :0 3 :5 2 6 :3 1 :5 2 6 :5 9 :5 2 7 :2 7 :5 2 7 :5 5 :5 2 8 :2 3 :5 2 8 :5 1 :5 2 9 :1 9 :5 2 9 :4 7 :5 2 1 0 :1 5 :5 2h a rm o n ic c u rr e n t (% ) time resmos fluke -0.5 0 0.5 1 1.5 2 2.5 3 3.5 1 6 :3 1 :5 2 1 7 :0 2 :5 2 1 7 :3 3 :5 2 1 8 :0 4 :5 2 1 8 :3 5 :5 2 1 9 :0 6 :5 2 1 9 :3 7 :5 2 2 0 :0 8 :5 2 2 0 :3 9 :5 2 2 1 :1 0 :5 2 2 1 :4 1 :5 2 2 2 :1 2 :5 2 2 2 :4 3 :5 2 2 3 :1 4 :5 2 2 3 :4 5 :5 2 0 :1 6 :5 2 0 :4 7 :5 2 1 :1 8 :5 2 1 :4 9 :5 2 2 :2 0 :5 2 2 :5 1 :5 2 3 :2 2 :5 2 3 :5 3 :5 2 4 :2 4 :5 2 4 :5 5 :5 2 5 :2 6 :5 2 5 :5 7 :5 2 6 :2 8 :5 2 6 :5 9 :5 2 7 :3 0 :5 2 8 :0 1 :5 2 8 :3 2 :5 2 9 :0 3 :5 2 9 :3 4 :5 2 1 0 :0 5 :5 2h a rm o n ic c u rr e n t (% ) time resmos fluke h.n. syamsir et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 1–10 10 vi. conclusions pc-based data logging systems provide the most customizations, flexibility, and scalable data logging solutions to meet numerous challenges. the device can be used to measure harmonic level and power quality with a confidence level above 95% and percentage error under 2.43% for thd and 1.72% for voltage harmonics. considered the comparison data sets, particularly the current harmonic data, the data agree on each other. the advantage of this tool can be used to measure power quality at the same time for ten channels and equipped with software making it easier for data analysis with low operational costs versus power quality equipment. for data storage, the binary data format in rtu allows storage of data can be done more because of the use operating system under dos. acknowledgement the authors gratefully acknowledgement to the centre of electrical energy systems, university technology malaysia, and the dataran berlian sdn.bhd for the financial support. references [1] hendri n.s and k. m.n, remote supervising and monitoring multi-channel data logging system. electrical energy and industrial electronic system (eeies 2009) on 7th-8th december 2009. [2] s. saha et al., “design of low cost multi channel data logger,” arpn j. eng. appl. sci., vol. 1, no. 1, 2006. [3] a. kumar et al., “design and development of multi-channel data logger for built environment,” in proceedings of the international multi conference of engineers and computer scientists imec, hong kong., vol.ii, march, 2010. [4] d. m. said and k. m. nor, “simulation of the impact of harmonics on distribution transformers,” in 2008 ieee 2nd international power and energy conference, 2008, pp. 335– 340. [5] khalid m.n., “the malaysian standards on power quality in the last decade (2000-2010). pqs 2010,” in power quality symposium 2010, kuala lumpur, july 13-14, 2010. [6] g. h. kjolle et al., “customer costs related to interruptions and voltage problems: methodology and results,” in ieee transactions on power systems, 2008, vol. 23, no. 3, pp. 1030–1038. [7] jonathan manson and roman targosz, “european power quality survery report, leonardo energy, vol. 1204, november,” 2008. [8] a. prudenzi et al., “power quality survey on italian industrial customers: paper industries,” in 2008 ieee power and energy society general meeting conversion and delivery of electrical energy in the 21st century, 2008, pp. 1–5. [9] s. elphick et al., “the australian long term power quality monitoring project,” in 2008 13th international conference on harmonics and quality of power, 2008, pp. 1–6. [10] e2i/epri, “assessing power quality impacts and solutions for the california food-processing industry, california energy commission public interest energy research program,” 2005. [11] r. targosz and j. manson, “pan-european power quality survey,” in 2007 9th international conference on electrical power quality and utilisation, 2007, pp. 1–6. [12] neville r. watson, “power quality, a new zealand perspective,” in power quality symposium (pqs 2010), kuala lumpur, july 13-14, 2010. [13] m. a. eldery et al., “a novel power quality monitoring allocation algorithm,” ieee trans. power deliv., vol. 21, no. 2, pp. 768–777, apr. 2006. [14] dalila m. s. and khalid m.n., “effects of harmonics on distribution transformers,” in australasian universities power engineering conference (aupec’08), sydney australia, december 14-17, 2008, pp. 1–5. [15] roman targosz, “end use perceptions of power quality – a european perspective,” in epri power quality applications (pqa) and advanced distribution automation (ada) joint conference and exhibition, european copper institute, june 12, 2007. j. mechatron. electr. power veh. technol 07 (2016) 93-104 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.93-104. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. optimal selection of lqr parameter using ais for lfc in a multi-area power system muhammad abdillah a,*, herlambang setiadi b, adelhard beni reihara a, c, karar mahmoud d, imam wahyudi farid a, adi soeprijanto e a department of cybernetics, graduate school of engineering, hiroshima university 4-1, kagamiyama 1chome, higashi-hiroshima, 739-8527, japan b department of electrical engineering, university of bhayangkara jl. ahmad yani 114, surabaya, east java 60231, indonesia c department of electrical engineering, university of papua jln. gunung salju, amban, manokwari, indonesia d faculty of engineering, aswan university sahari city-airport way, aswan, 81528, egypt e department of electrical engineering, institut teknologi sepuluh nopember, building b, c & aj campus its sukolilo surabaya, east java 60111, indonesia received 30 march 2016; received in revised form 01 october 2016; accepted 03 october 2016 published online 23 december 2016 abstract this paper proposes a method to optimize the parameter of the linear quadratic regulator (lqr) using artificial immune system (ais) via clonal selection. the parameters of lqr utilized in this paper are the weighting matrices q and r. the optimal lqr control for load frequency control (lfc) is installed on each area as a decentralized control scheme. the aim of this control design is to improve the dynamic performance of lfc automatically when unexpected load change occurred on power system network. the change of load demands 0.01 p.u used as a disturbance is applied to lfc in area 1. the proposed method guarantees the stability of the overall closed-loop system. the simulation result shows that the proposed method can reduce the overshoot of the system and compress the time response to steady-state which is better compared to trial error method (tem) and without optimal lqr control. keywords: linear quadratic regulator (lqr); artificial immune system; clonal selection; load frequency control (lfc) i. introduction load frequency control (lfc) is one of the main parts of the power system where the main function of lfc is to maintain the frequency fluctuation during exchange power in the power system network on which the generator dispatch must satisfy the system conditions caused by the fluctuation of load change [1]. multi-area power system is a complex dynamic system. the decentralized control design is suitable for multi-area power system because the controller is set to work in each area. the controller works based on the information only on each area. when any change of output variables in one area occurs, only the controller takes action in order to maintain the stability from a disturbance in its area. the improvement of the dynamic performance caused by small load change has been reported by robandy et al. [2] and the application of optimal control to improve the dynamic performance on power system using a linear quadratic regulator (lqr) is provided by mahmud et al. [3]. the method used to improve the dynamic performance on power system by those two previous researches [2, 3] provides satisfactory results. the number of control strategies has been employed in control design of lfc in order to achieve better dynamic performance [4-6]. * corresponding author. tel: +81-8042671315 e-mail: abdee.muhammad83@gmail.com http://dx.doi.org/10.14203/j.mev.2016.v7.87-92 m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 94 many types of artificial immune system (ais) algorithms are based on the variety of immunological studies such as immune network [7], negative selection [8], danger theory [9], and clonal selection [10]. clonal selection algorithm (csa) is a special type of ais which uses the clonal selection part of the ais as the main mechanism. clonal selection is based on a situation of ‘b’ cell response against nonselfmolecule called antigen with an affinity by proliferating and producing antibody in order to kill antigenic cells [11]. ais via clonal selection is one of metaheuristic methods utilized to solve a complex problem in optimization research field. the optimal solution obtained by ais via clonal selection is better than optimal solution produced by a genetic algorithm (ga) [12]. furthermore, the ais via clonal selection is more efficient than other classical heuristic algorithms such as simulated annealing (sa), tabu search (tb), and ga [13]. ais via clonal selection had received much attention regarding its potential as a global optimization technique and it has been applied in power system research field as reported in [1416]. in research by li et al. [14], ais via clonal was used for allocating an optimal var compensator in power system. ais via clonal selection was used to adjust the parameter of pss based lqr in the single machine infinite bus (smib) by haybar et al. [15]. the authors apply optimal lqr control as pss to a study dynamic stability. maryono et al. [16] uses ais via clonal selection for tuning parameter of the thyristor controlled series capacitor (tcsc) and pss for damping controller in power system. this paper proposes ais via clonal selection to tune q and r matrices as to obtain feedback controller gain where applied for multi-area load frequency control (lfc). some of the classical control approaches for lfc are based on mathematical models. these approaches have difficulties in gaining the control purposes in the presence of changing the operating points such as load changes under which the model is derived, and lack of system components. in order to tackle these limitations, an application of intelligent technology is proposed. in this paper, ais via clonal selection method is utilized to optimize the parameters of lqr. the weighting matrices q and r of lqr are important parameters which obtaining an optimal feedback gain to improve the dynamic performance of lfc in multi-area power system by observing the change of frequency in each area. this paper is organized as follows: the power system model of lfc for multi-area power system is explicated in section ii. the proposed method is introduced in section iii. the implementation of proposed method is given in section iv. the simulation results are shown in section v. ii. power system model the configuration of a multi-area power system in this paper is depicted in figure 1. it consists of 4 lfc areas where each area has a number of generators. all generators in one area are simplified as an equivalent generator unit (egu). in a certain lfc area the dynamical model of its egu can be expressed as follows: without generator rates and/or turbine dead-band, the dynamic model can be expressed as a linear model in the following equations. iitiemii fppf ∆−∆−∆=∆ − pipi pi pi pi t 1 t k t k  lip∆− pi pi t k (1) tigiti ppp ∆−∆=∆ titi t 1 t 1  (2) giicigi pfpp ∆−∆−∆=∆ giigigi t 1 rt 1 t 1  iu git 1 + (3) itieici pfp −∆−∆−=∆ iiiii kbk (4) ( )ij ij 1 t ttie i i jp f fs− ∆ = ∆ − ∆� (5) the linear dynamic model of the ith lfc area is depicted in figure 2. equations (1)-(5) form a state-space model representation as follow [17]: x i(t)=aixi(t)+ ∑ ≠ = n a x ij 1j ij )t(j +biui(t)+fi ∆ pli(t) (6) yi(t)= cixi(t) (7) where n( )ix t ∈ℜ is state variable of area i, m)( ℜ∈tui is input variable of area i, and r)( ℜ∈tyi is output variable of area i. the variables are defined as follows: 1area 2area 4area 3area figure 1. multi-area power system configuration m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 95 xi(t) = [ ∆ fi ∆ pti ∆ pgi ∆ pci ∆ ptie-i]t (8) ui (t) = the i-th area input signal of acei (9) acei = ∆ ptie-i + bi ∆ fi (10) yi (t) = ∆ fi (11) definitions of model parameters and variables stated in equations (1)–(7) are shown in table 1. by combining 4 egus, a block diagram of lfc in the four areas power systems can be illustrated in figure 3. its state space equation is described as follows: x i(t)=aixi(t)+ ∑ ≠ = n a x ij 1j ij )t(j +biui(t)+fi ∆ pli(t) (12) )()( txty c= (13) state variable, input variable and output are given by: x(t)=[δ f1 δ pt1 δ pg1 δ pc1 δ ptie-1 δ f2 δ pt2 δ pg2 δ pc2 δ ptie-2 δ f3 δ pt3 δ pg3 δ pc3 δ ptie-3 δ f4 δ pt4 δ pg4 δ pc4 δ ptie-4]t (14) pist1 pik + tist1 1 + gist1 1 + ir 1 ipc∆ itp∆ lip∆ itiep −∆ if∆ ib s iik− iace + igp∆ + + + +− ijt s 1 + jf∆ + nf∆ if∆ ijt … . …. itiep −∆ the i-th area iu figure 2. a linear block diagram of the i-th lfc area table 1. definitions of model parameters and variables parameter/ variable decriptions δfi the i-th area frequency deviation δpti the i-th area turbine output deviation δpgi the i-th area governor output deviation δpci the i-th area control input deviation δptie-i the i-th area net tie-line power deviation δpl-i the i-th area load disturbance di the i-th area load damping coefficient mi the i-th area inertia constant ri the it-h area governor speed regulation tti the i-th area turbine time constant tgi the i-th area governor time constant tij the i-th area synchronizing coefficient kii the i-th area integration gain bi the i-th area frequency bias parameter kpi the i-th area power system gain tpi the i-th area power system time constant ui the i-th area input signal m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 96 u(t)=[u1 u 2 u3 u 4]t (15) y(t)=[δf1 δf2 δf3 δf4]t (16) where δf1, δf2, δf3, δf4 are frequency deviation for area 1, 2, 3, and 4, respectively; δpt1, δpt2, δpt3, δpt4 express of turbine output deviation for area 1, 2, 3, and 4; δpg1, δpg2, δpg3, δpg4 denote of governor output deviation for area 1, 2, 3, and 4; δpc1, δpc2, δpc3, δpc4 refer to control input deviation of area 1, 2, 3, and 4; δptie-1, δptie-2, δptie3, δptie-4 stand for deviation in net tie-line power of area 1, 2, 3, and 4; u1, u2, u3, u4 denote for input signal of area 1, 2, 3, and 4 respectively. matrix representation of the state space and output equations of the lfc in one area power system is as follows: 1 1 1 p p st k + 11 1 chst+11 1 gst+ 1b 1 1 r 1ace 1e∆ 1pc∆ 1lp∆ + + ++ + 1f∆ s k i 1− + + s 1 + + 12t 13t 14t + + 2 2 1 p p st k + 21 1 chst+21 1 gst+ 2b 2 1 r 2ace 2e∆ 2pc∆ 2lp∆ + + ++ + 2f∆ s k i 2− +s 1 + 21t 23t + 3 3 1 p p st k + 31 1 chst+31 1 gst+ 3b 3 1 r 3ace 2e∆ 3pc∆ 3lp∆ + + ++ + 3f∆ s k i 3− +s 1 + 31 t 32t + 4 4 1 p p st k + 41 1 chst+41 1 gst+ 4b 4 1 r 4ace 4e∆ 4pc∆ 4lp∆ + + ++ + 4f∆ s k i 4− s 1 41t 2tp∆ 1tp∆1g p∆ 2gp∆ 3tp∆3gp∆ 4tp∆4gp∆ u2 u3 u1 u4 figure 3. block diagram of 4 areas lfc power system in linear model m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 97                           ∑ −×− − × − − −− = 0000 j ij t iik000ibiik 0 git 1 git 1 0 igtgir 1 00 tit 1 tit 1 0 pit pik 00 pit pik ipt 1 iia (17)               = 0000 00000 00000 00000 00000 ijt2i π ja (18)               − =≠ 0000t 00000 00000 00000 00000 )( ij jiijh (19) [ ]tii 00t100 gi=b (20) [ ]tii 0000tk pipi−=f (21) [ ]00001=iic (22) the parameters of lfc for the four areas interconnection power system are provided in table 2. iii. proposed method this paper proposes the well-known optimal linear quadratic regulator (lqr) where the parameters of lqr are optimized by ais via clonal selection to design load frequency control system. a. linear quadratic regulator (lqr) an optimal control system based on lqr can be stated as a matter of practical control system then it is desirable to minimize an error signal function. its application can be expressed in the form of a block diagram as illustrated in figure 4. in order to obtain the necessary control signal u, amplifier controller k has to be obtained from lqr method. on the other hand, to keep the system stable, a stable controller is required. the plant is assumed to be a linear time-invariant (lti) system which can be expressed in equation (12) and equation (13). based on lqr theory, the control signal can be calculated as follows [8]. a quadratic criterion is chosen to optimize the problem with its performance index is as follows, )t(x)t(s)t(x)t(j t 2 1 0 = ∫ ++ t t tt dt)t(u)t(u)t(x)t(x 0 ][ 2 1 rq (23) where t0 is the initial condition of the system, s(t)≥0 (positive semi-definite), q≥0 (positive semi-definite) and r>0 (positive definite) with the dimension qnxn and rmxm respectively. s(t), q, and r are symmetric shaped weights matrices. table 2. parameters of lfc for the 4 areas interconnection power system [17] area 1 area 2 area 3 area 4 kp1 120hz/pumw kp2 112.5hz/pumw kp3 125hz/pumw kp4 115hz/pumw tg1 0.08s tg2 0.072s tg3 0.07s tg4 0.085s tp1 20s tp2 25s tp3 20s tp4 15s tt1 0.3s tt2 0.33s tt3 0.35s tt4 0.375s rg1 2.4hz/pumw rg2 2.7hz/pumw rg3 2.5hz/pumw rg4 2hz/pumw ki1= ki2= ki3= ki4=0.6 b1= b2= b3= b4=0.425 pumw/hz t12= t13= t14= t21= t23= t31= t32= t41=0.545 t24= t34= t42= t43=0 ∑ + u plant outputreference lqrk figure 4. block diagram control system m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 98 from optimal control theory, the gain and control input are given by the following equations: )t(s)t( tbrk 1−= , ∈ ℜmxn (24) )t(x)t()t(u k−= (25) s(t) is the solution of the following riccati equation: qbbraa +−+=− − sssss tt 1 (26) the state space of the closed loop system is x)()t(x bka −= (27) in the closed-loop system matrix, riccati equation becomes joseph stabilized formulation as follows: qrkkbkabka ++−+−=− tt )(ss)(s (28) and ∫ ++= − t t r tt dtusx)t(x)t(s)t(x)t(j 21 2 1 2 1 br (29) the performance index on [t,t] become: )()()( 2 1 )( txtstxtj t= (30) gain matrix k in equation (25) which is obtained from equation (24) is substituted into equation (26) then fed it back to the system in order to obtain the minimum output. b. artificial immune system (ais) ais is an optimization algorithm that mimics human immune system. the immune system has the function to protect the human body from the attack of foreign organisms. the immune system has the ability to differentiate between the normal components of our organism and the foreign organism that can cause harm. the foreign organisms are called antigens. the molecules called antibodies have an important role in the immune system response. the immune system response is specific to a certain antigen. when an antigen is known, those antibodies that best identify an antigen will proliferate by cloning. this process is called clonal selection principle. the principle of ais via clonal selection is illustrated in figure 5 [10, 11]. three aspects of the clonal selection concept are described as follows: a) the new cells which are submitted to chromosomal mutation chemical mechanism are verily duplicated of their parents. b) evacuation of newly differentiated lymph cell is bringing self-reactive sensory receptor. c) development and differentiation on contact of mature cells with antigens. sub population of bone marrow cells derived (b lymphocytes) will react by resulting anti bodies (ab) when an antibody is strongly matched to an antigen. every cell confidential only has one type of antibody which is relatively specific for the antigen. the antigen is identified by antibody with a particular affinity (degree of match), the b lymphocytes will be encouraged to proliferate (divide) and finally grow into terminal (nondividing) antibody secreting cells, called plasma cell. the proliferation of the b lymphocytes is a mitotic process with the help of the cells divides themselves, producing a set of clones identical to the parent cell. the proliferation degree is proportional to the affinity level, i.e. the higher affinity levels of b lymphocyte, the more of them will be readily chosen for cloning and cloned in large numbers. in addition to proliferating and mature into plasma cells, the immune cells can distinguish into the long-lived memory cell. memory cells distribute through the blood, lymph, and tissues, and when exposed to the second antigenic stimulus they commence into large immune cells (lymphocyte) capable of producing high affinity antibody specific antigen that once stimulated the primary response. pseudo code of ais via clonal selection is described as follows [11]: p ← rand(n, l) while not stop condition do for each p of p do // presentation affinity(p) end for p1 ← select(p, n) // clonal selection for each p1 of p1 do // clonal expansion c ← clone(p1) figure 5. artificial immune system (ais) via clonal selection [11] m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 99 end for for each c of c do //affinity maturation hypermutation(c) end for for each c of c do // presentation affinity(c) end for p ← insert (c, n) // greedy selection pr ← rand (d, l) p ← replace (p. d. pr) // random replacement end while the description of parameter for ais via clonal selection is illustrated in table 3. c. implementation of proposed method in this section, the implementation of ais via clonal selection to optimize the parameters of optimal lqr control is described. the scheme of optimal lqr control is illustrated in figure 6. klqr in figure 6 is a gain for feedback control obtained from the solution of equation (26). the ais via clonal selection serves as a tool to adjust the values contained in q and r matrices automatically which are a very important component of optimal lqr control. equation (30) is used as the performance index (j) of the system which will be minimize in this paper. this function is used as an affinity function in the optimization process. flowchart of ais via clonal selection utilized to select the optimal weighting matrices q and r is shown in figure 7. computation procedure of ais via clonal selection to obtain optimal lqr parameters depicted in figure 7 is as follows: a. generate initial population of antibody: generate initial antibody in population. b. calculate the objective function (affinity): performance index used as objective function is defined as follows: )()()( 2 1 )( txtstxtj t= (31) subject to, min max min maxr r r ≤ ≤ ≤ ≤ q q q where qmin, qmax, rmin, rmax are 0, 100, 0, 10, respectively. c. select the best antibody by measuring their affinities: affinity is calculated by performance index in step b. antibody with high affinity is the best antibody in this algorithm. d. clone best antibody: antibody with high affinity in population has higher probabilities will be cloned. e. take into account the population of clones to an affinity maturation scheme: antibody with lower affinity has higher probabilities will be hyper-mutated. table 3. ais via clonal selection description parameter description p antibodies’ repertoire n number of antibodies n antibodies will be selected for cloning l bit string length for each antibody nc number of clone produced by each selected antibody d random number of antibodies to insert at the end of each generation. best antibodies replace the d lowest affinity antibodies in the repertoire stop condition maximum generation affinity solution evolution clone duplication of selected bit string hypermutate modification of a bit string where the flipping of bit (it may be single bit or multiple bit) is governed by an affinity proportionate probability distribution the ith control area −∆ tie ip dip∆ if∆ n lqr−− ∑ j j j=1 x k ui + optimal lqr control scheme +reference figure 6. optimal lqr control scheme power system model using equation (8) and (9) start designing matrices q and r using ais via clonal selection lqr optimization process using equation (12), (13) & (15) is j minimum ? start no yes figure 7. proposed method m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 100 f. re-select: every antibody is re-select based on step b. g. replace a new antibody to the previous antibody: antibody with lower affinity will be replaced. iv. numerical studies all simulations are implemented on a desktop personal computer with a 2.20 ghz intel core i7 processor with 8 gb of ram using the matlab software environment. we set the number of antibodies for ais via clonal selection to 50, the maximum number of generations to 100 for all areas. the proposed method is examined by applying the change of load 0.01 p.u on area 1 as a disturbance. the convergence curves of ais via clonal selection for the best affinity values on each area are illustrated in figure 8. figure 8 shows that ais via clonal selection reaches the convergence value at generation 19, 6, 43, 66 for area 1, 2, 3, and 4, respectively. performance index (pi) value of optimal lqr control on each area is illustrated in table 4. although the maximum generation is set to 100, the ais via clonal selection for area 1 to area 4 had reached earlier than a maximum generation for all areas. the comparison of matrices q and r obtained by trial and error (tem) and ais via clonal selection are listed in table 5. frequency deviation and control input deviation for area 1 to area 4 are depicted in figure 9 (a) and (b) to 12 (a) and (b). from figure 9 (a) and (b) to 12 (a) and (b), we can observe that the smallest overshoot and settling time are obtained by the proposed method. the values of overshoot and settling time in figure 9 to figure 12 are shown in table 6 and table 7. from table 6 and table 7, we can observe that the shortest settling time and minimum overshoot of frequency deviation table 4. pi value of optimal lqr control using ais via clonal selection area j (minimum) 1 0.7824 2 0.2053 3 0.4339 4 0.4092 table 5. parameter of optimal lqr control area parameter of optimal lqr control tem ais via clonal selection q r q r 1 0.7 0.7 0.7 0.7 0.7 2.4 72.2633 1.0000 27.3150 4.7557 3.0630 1 2 0.7 0.7 0.7 0.7 0.7 2.7 14.2810 94.0000 68.3249 8.0154 3.8331 1 3 0.7 0.7 0.7 0.7 0.7 2.5 61.2065 0 39.3815 25.3775 28.6025 1 4 0.7 0.7 0.7 0.7 0.7 2 94.8829 0 64.8708 23.3996 7.7552 1 0 10 20 30 40 50 60 70 80 90 100 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 generation p er fo rm an ce i nd ex j (m in im um ) area1 area2 area3 area4 figure 8. convergence curve of ais via clonal selection m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 101 can be obtained by ais via clonal selection. system without optimal lqr control is the worst; this system used manual gain feedback to produce signal control of the system. the best (a) (b) figure 9. frequency and control input deviations on area 1: (a) frequency deviation ∆ f1; (b) control input deviation δpc1 (a) (b) figure 10. frequency and control input deviations on area 2: (a) frequency deviation ∆ f2; (b) control input deviation δpc2 m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 102 performance of the system is lfc equipped by the optimal control which was tuned by ais via clonal selection. if the control input has a good response, less overshoot and faster settling time then the response of the system will be as good as the control input. (a) (b) figure 11. frequency and control input deviations on area 3: (a) frequency deviation ∆ f3; (b) control input deviation δpc3 (a) (b) figure 12. frequency and control input deviations on area 4: (a) frequency deviation ∆ f4; (b) control input deviation δpc4 m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 103 v. conclusion in this paper, load frequency control (lfc) for multi-area power system network is presented. the impact of lfc control method to maintain the frequency fluctuation caused by load change is examined. an application of ais via clonal selection to determine the optimal lqr control parameters is provided. the advantage of the proposed method is that it can adjust automatically the parameters of optimal lqr control when there is load change on power system network. although trial error method (tem) is simple, it is difficult to obtain optimal control performances. also, it takes a long time to select the best optimal lqr control parameters. it is clear that optimal lqr control optimized by ais via clonal selection is more suitable to improve the system dynamic than tem. acknowledgement the authors are grateful to all anonymous reviewers for their valuable suggestions in order to improve the quality of our paper. references [1] r. w. w. atmaja et al., “optimal design of pid controller in interconnected load frequency control using hybrid differential evolutionparticle swarm optimization algorithm,” in proceedings of 2014 seminar on intelligent technology and its applications, 2014. [2] i. robandi, desain sistem tenaga modern, penerbit andi yogyakarta, 2006. [3] m. a. mahmud, “an alternative lqr-based excitation controller design for power systems to enhance small-signal stability,” international journal of electrical power and energy systems, vol. 63, pp. 1-7, 2014. [4] s. k. pandey et al., ”a literature survey on load frequency control for conventional and distribution generation power systems,” renewable and sustainable energy reviews, vol. 25, pp. 318–34, 2013. [5] ibraheem et al., “agc of two area power system interconnected by ac/dc links with diverse sources in each area,” international journal of electrical power and energy systems, vol. 55, pp. 297–304, 2014. [6] m. r. sathya and m. m. t. ansari, “load frequency control using bat inspired algorithm based dual mode gain scheduling of pi controllers for interconnected power system,” international journal of electrical power and energy systems, vol. 64, pp. 365–74, 2015. [7] x. hao and s. cai-xin, “artificial immune network classification algorithm for fault diagnosis of power transformer,” ieee transaction on power delivery, vol. 22, pp. 930-935, 2007. [8] i. idris and a. selamat, “negative selection algorithm in artificial immune system for spam detection, ” in proceedings of the 2011 ieee software engineering, pp. 379-382, 2011. [9] y. zhuang et al., “information security risk assessment dased on artificial immune danger theory,” in proceedings of the 2009 ieee computing in the global information technology, pp. 169-174, 2009. [10] m. w. yaw et al., “optimization of the multi-flow rate mode selection for pneumatic dispensing valve system using clonal selection based artificial immune system algorithm,” in proceedings of the table 7. settling time (second) output without optimal lqr control trial-error method (tem) optimal control ais ∆ f1 >20 8.01 6.34 ∆ f2 >20 7.58 5.32 ∆ f3 >20 7.99 5.90 ∆ f4 >20 7.67 5.12 ∆ pc1 >20 9.89 13.57 ∆ pc2 >20 10.67 7.13 ∆ pc3 >20 17.26 15.11 ∆ pc4 >20 16.11 14.29 table 6. overshoot (p.u) output without optimal lqr control trial-error method (tem) optimal control ais ∆ f1 -0.01583 -0.006319 -0.0009466 ∆ f2 -0.009948 -0.001992 -0.0003705 ∆ f3 -0.009625 -0.001986 -0.0003067 ∆ f4 -0.01038 -0.001985 -0.0002702 ∆ u1 0.01043 0.00565 0.001685 ∆ u2 0.0008278 -0.000426 -0.000144 ∆ u3 0.0005908 -0.0003785 -0.0001659 ∆ u4 0.0004677 -0.0003806 -0.000215 m. abdillah et al. / j. mechatron. electr. power veh. technol 07 (2016) 93-104 104 2011 ieee control system, computing and engineering, pp. 327-331, 2011. [11] l. n. de castro and j. timmis, “artificial immune system: a novel paradigm to pattern recognition, ” in proceeding of soco, university of paisley, uk, pp. 67-84, 2002. [12] e. hart et al., “producing robust schedules via an artificial immune system,” in proceedings of the international conference on electronic commerce 1998 (icec’98), april 6-9, 1998. [13] e. hart and p. ross, “an immune system approach to scheduling in changing environments,” in proceedings of the genetic and evolutionary computation conference 1999 (gecco’99), july 13-17, 1999. [14] y. li et al., “improved immune algorithm for reactive power optimization,” in proceeding of 2013 ieee instrumentation and measurement, sensor network and automation, pp. 458-462, 2013. [15] z. haybar et al., “dynamic power system stability improvement on single-machine power system using optimal artificial immune system power system stabilizer (opaispss),” in proceedings of seminar nasional efisiensi dan konversi energi, 2006. [16] h. maryono et al., “coordination of power system stabilizer (pss) and thyristor controlled series capacitor (tcsc) damping controller using ais via clonal selection,” in proceeding of seminar on intelligent technology and its applications (sitia), 2006 (in indonesian languange). [17] t. c. yang et al., “decentralized power system load frequency control beyond the limit of diagonal dominance,” international journal of electrical power and energy systems, vol. 24, pp. 173-184, 2002. received 30 march 2016; received in revised form 01 october 2016; accepted 03 october 2016 i. introduction ii. power system model iii. proposed method a. linear quadratic regulator (lqr) b. artificial immune system (ais) implementation of proposed method iv. numerical studies v. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. ir. suhono h supangkat, m.eng, cgeit. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. dr. ir. zainal abidin mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. ir. adi soeprijanto, mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. iman k reksowardojo mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135 indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia ocktaeck lim, ph. d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan korea, republic of dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810, indonesia ir. edi leksono, m.eng, ph.d. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia esa prakasa, ph.d research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. arjon turnip technical management unit for instrumentation development lipi komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2ndfl, bandung 40135, indonesia dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. sunit hendrana research center for physics lipi komp lipi jl sangkuriang, blg 60, 2nd fl, bandung 40135, indonesia dr. ary setijadi prihatmanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. feri yusivar, m.eng department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, st., mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. widodo budi santoso research center for electical power and mechatronics-lipi komp lipi jl sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia slamet riyadi, s. ds., m.ds. product design department faculty of art and design bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. https://www.crossref.org/services/crossmark/ http://publicationethics.org/files/retraction%20guidelines.pdf journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with semi colon and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2017.v8.95-102 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter fri murdiya a, *, febrizal a, amun amri b a department of electrical engineering, faculty of engineering, universitas riau jl. h.r. subrantas km. 12,5 kampus binawidya simpang baru panam, pekanbaru, riau, indonesia b department of chemical engineering, faculty of engineering, universitas riau jl. h.r. subrantas km. 12,5 kampus binawidya simpang baru panam, pekanbaru, riau, indonesia received 25 september 2017; received in revised form 13 december 2017; accepted 15 december 2017 published online 28 december 2017 abstract this paper reports an application of a series resonance converter as a high voltage generator to drive a surface barrier discharge with a magnetic field. the high voltage was about 5 kv with the frequency of 25 khz. it was connected to circular aluminum plates as the anode electrode and a rectangular aluminum plate as the cathode electrode. these electrodes were separated by a glass dielectric as the barrier. the experiment result indicated that the discharge current with magnetic field was lower than without magnetic field. the plasma on the surface barrier with magnetic field was more luminous than without magnetic field. it also indicated that the area of lissajous diagram for the surface barrier discharge with magnetic field was slightly decreased than without magnetic field. it could be concluded that the magnetic field affects the plasma progress on the surface barrier. molecular dynamic (md) could be used in understanding the ionization process of air molecules. the ionization energies for co2, n2, and o2 were 0.0502 kcal/mol, 0.0526 kcal/mol and 0.430 kcal/mol, respectively in 1,000 seconds. the highest ionization energy was o2. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: surface barrier discharge; magnetic field; series resonance converter; molecular dynamic; ionization energy. i. introduction high voltage plasma generator has been used in many areas such as in medical, chemistry, physics, etc. this technology includes high voltage generator, electrodes, and dielectric. one way to get the plasma is by increasing the voltage until that material was initiated into the plasma (discharge) and eyes can see it. in the theory of high voltage engineering, the plasma formation process is the unsuccessful of the material to defend itself as an insulating material. this process was known as electron discharges or gas ionization. high voltage plasma technology was applied in the ozone generation, bacteria destruction in the drinking water, decomposition of dangerous organic compounds in the drinking water and also the decomposition of nox compounds from diesel engine fumes [1], [2]. ayman et al. reported about decomposition of naphthalene using high voltage with mica dielectric material [3], [4]. in this decomposition, ozone is needed. this ozone was formed from oxygen using high voltage plasma. lukes et al. have designed cylindrical electrodes and a ceramic dielectric made of aluminum compounds (al2o3) to produce plasma in the water [5]. currently, the most common application of the high voltage plasma generators is the ozone generator through an air ionization process under corona exposure with dc voltage [6]. in order to produce high voltage plasma in the reactor, there are some configurations of barrier discharge such as cylindrical, planar, and surface barrier discharges as presented in figure 1. the presence of dielectric layer between metallic electrodes is to increase the electric field density in the gap or surface and it leads to occur the barrier discharge process in the gap. typical materials for dielectric barriers are glass, teflon, acrylic, quartz, and ceramics. the most important characteristics in dielectric barrier discharge are the presence of a capacitive coupling of * corresponding author. tel: +62 812 8881 6276 e-mail address: frimurdiya@eng.unri.ac.id https://dx.doi.org/10.14203/j.mev.2017.v8.95-102 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.95-102 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.95-102&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 96 the insulation material that can be driven by high frequency alternating current and pulsed dc voltage as well [7]. power supply with the frequency from 22 khz to 50 khz has been used to initiate plasma between the electrode and dielectric material. high frequency was chosen for this power supply to decrease the transformer dimension. this transformer was used to convert low voltage into high voltage up to 8 kv [1]. salam et al. reported another research about power supply without transformer, for then it can be applied to make ozone from oxygen [8]. this power supply used the boost converter with a voltage of 4 kv. fly back converter was also used to initiate dielectric barrier discharge for argon initiation process [9], [10]. t. c manley proposed the measurement technique of power dissipation from high voltage plasma generator using lissajous diagram as referring to figure 2 [11]. in addition, it was also used in high voltage research like oil insulation test using sawyer-tower circuit [12]. in order to determine lissajous figure as referring to figure 2, we can use the formula for the electric energy consumed per voltage cycle ( 𝐸𝑒𝑙 ) and the electric power (𝑃𝑒𝑙 ). the electric energy consumed per voltage cycle 𝐸𝑒𝑙 is closed integral of applied voltage (u) and total charge (q), and it can be derived by using equation (1). 𝐸𝑒𝑙 = ∮ 𝑈(𝑡)𝑑𝑄 (1) park et al. investigated the characteristic of plasma by using multi needles as high voltage electrodes, which were placed above the dielectric material [13]. there was a gap between the needles and the dielectric material. in this experiment, he was also investigated the effect of magnetic field on the performance of plasma. the position of the magnetic field was perpendicular to the electric field [13]. pakarek et al. also research the use of a needle as a high-voltage electrode [14]. the position of the permanent magnet was parallel to the needle electrode. the permanent magnet induced the movement of electrons after the plasma released in the gas insulation [14]. liu et al. conducted a study to figure out the differences between planar barrier discharge in the magnetic field and without a magnetic field in the air. the nanosecond pulsed power source was installed on the planar barrier discharge. it was found that the characteristics of barrier discharge in magnetic field and without magnetic field were slightly different [15]. generally, another investigation is the surface barrier discharge to produce the ozone gas. the researchers have applied this technology, and they did not considered the effect of the magnetic field to plasma progress. the comparison of the performance of surface barrier discharge with and without magnetic field is very interesting. these data will answer why we should use magnetic field to produce plasma on the surface barrier. the effect of the magnetic field on the surface barrier discharge needs to be verified by several things such as plasma, discharge current, and power dissipation, etc. in order to study the differences between surface barrier discharge with magnetic field and without magnetic field, we need to do research. in this research, a high voltage plasma generator has been tested using an aluminum plane electrode and a glass dielectric. it was controlled by a high voltage power supply up to voltage level of 5 kv with the frequency of 25 khz using an lc resonance oscillation circuit. this power supply converts the dc input voltage into high voltage up to 5 kv using a ferrite transformer. in this investigation, we attempted to find the effect of the magnetic field to the surface barrier discharge progress on the surface glass material as a dielectric. some measurements have been done such as power dissipation, current, and output voltage of the plasma generator. we used air as the gas insulation. ii. molecular dynamic theory the general content of the air consists of several elements of gases such as n2, co2, and o2. air ionization is caused by sunlight, high electric fields and collisions between electrons from gas molecules. this ionized air in high voltage leads to the event of isolation figure 1. dielectric barrier discharge configuration; (a). cylindrical barrier discharge; (b) planar barrier discharge; (c) surface barrier discharge [7] figure 2. u-q lissajous figure [11] f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 97 failure or better known as the failure process of streamer and townsend. in order to study on ionized air, molecular dynamic (md) can be used to understand the ionization process of the molecule. md was developed to provide a thermodynamically accurate mess scale model capable of describing nonequilibrium process such as shocks. there are many factors that will influence to the md simulation. the important characteristic of md simulation is the planck constant [16], [17]. the planck constant (denoted ℎ , also called planck's constant) is a physical constant that is the quantum of action, central in quantum mechanics. generally, it can be written as follow: 𝐸 = ℎ𝑣 (2) where 𝐸 is energy, ℎ is planck constant and 𝑣 is frequency. based on this equation, if the energy is higher, planck constant and frequency is also will be increasing. the other factor is volume, the original formulation of the isothermal-isobaric ensemble can be traced back to 1939, where guggenheim wrote the partition function, ∆(𝑁, 𝑃, 𝑇), as follow: ∆(𝑁, 𝑃, 𝑇) = 𝑋 𝑉 𝑄(𝑁, 𝑉, 𝑇)𝑒 − 𝑃 𝑉 /𝑘𝐵𝑇 (3) where kb is boltzmann constant, 𝑄(𝑁, 𝑉, 𝑇) is the canonical ensemble partition function of a system composed of 𝑁 particles held in a volume 𝑉 , and at a temperature 𝑇, and 𝑃 is the external pressure to which the system is exposed as the volume is allowed to fluctuate. the third factor is timing, time-dependent statistical mechanics is important in the md simulation. firstly, in recent years, there have been significant advances in the understanding of molecular dynamics algorithms, which have arisen out of an appreciation of the formal operator approach to classical mechanics. second, an understanding of equilibrium time correlation functions, their link with dynamical properties, and especially their connection with transport coefficients, is essential in making contact with experiment. third, the last decade has seen a rapid development of the use of nonequilibrium molecular dynamics, with a better understanding of the formal aspects, particularly the link between the dynamical algorithm, dissipation, chaos, and fractal geometry [18], [19]. iii. research method a. experimental set-up the experiment was carried out by arranging the electrical circuit in figure 3. high voltage generator was installed at the left side of figure 3 such as a half bridge converter and it was connected to an lc resonance and then, they were connected to a ferrite transformer with ratio 1:200. the input power supply was 220 v ac and frequency of 50 hz and 150 watt. the frequency of resonance converter was 25 khz. the maximum output voltage at seconder ferrite transformer was about 5 kv. the seconder transformer terminal was connected to an anode electrode (circular aluminum plate with dimension 8 cm in diameter and thickness of 1 mm) and the cathode electrode (aluminum plates with dimension 100 mm x 100mm x 1mm) was connected to another side of transformer terminal. a dielectric glass (with dimension 100x100x5 in mm) was put above the cathode electrode. this dielectric was the window glass. if the high voltage power supply was energized, it would initiate electrical discharge (plasma) in the air on the surface barrier. we installed a permanent magnet under a cathode electrode with a density of magnetic field in this research was about 315 mt, it was measured by fh51 gauss tesla meter. the plasma occurred on surface barrier was recorded by a digital camera (sony xperia 14 megapixels). the high voltage power supply was measured by using a high voltage probe p2300c and it was connected to a digital oscilloscope (hantek bmv5200). in order to achieve lissajous figure, the voltage of capacitor cs was measured by an oscilloscope probe with setting 1x and it was known as sawyer-tower circuit [12]. discharge current was recorded by hantek cc650 probe. during the experiment, the free air was used in this study. we did not use a pump to spray air into the discharge medium. the experiment was conducted under room temperature and air pressure of 1 atm. we compared the properties of surface barrier discharge progress in the magnetic field (model i) and without magnetic field (model ii). figure 3. schematic diagram of experiment hantek oscilloscope high voltage probe p2300c 300 mhz cs _metal plate glass 5 mm gap 0.5 cm l c h a lf b ri d g e ac 220 v 50 hz ferrite transformer 1 : 200 magnet camera current probe cc650 hantek https://en.wikipedia.org/wiki/physical_constant https://en.wikipedia.org/wiki/quantum https://en.wikipedia.org/wiki/action_(physics) https://en.wikipedia.org/wiki/quantum_mechanics f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 98 b. molecular dynamic simulation molecular dynamics simulation consists of a stepby-step numerical solution of the classical equations of motion. in addition, calculations might give a guide to the “best” molecular force-field; also a comparison of simulation results with thermo physical properties and vibration frequencies was invaluable in force-field development and refinement. a separate family of force fields, such as amber17, amber18, charmm19, and opls20 was geared to larger molecules (proteins, polymers) in condensed phases; their functional form was simpler. a preliminary study of molecular dynamics simulation was performed using namd (nanoscale molecular dynamics program; v 2.9), it has been done to see the ionization process of gas o2, n2, co2. charmm19 (chemistry at harvard macromolecular mechanics) was selected as a force field, npa was then used as an algorithm and nvt was used as an ensemble parameter [16]. iv. results and discussion a. surface barrier discharge the development of plasma on surface barrier was occurred because of air failure to maintain itself as the gas insulation. this was also marked by the use of high voltage with high frequency that can decrease the air breakdown voltage and the air can be ionized. this ionized air (especially oxygen) easily formed itself into an ozone gas. the charge transfer on surface dielectric material was mainly determined by the sort of dielectric and the width of the gas gap. the surface barrier discharge released the plasma and it was fully separated at the end of electrode. the color of plasma was purple. both plasmas developed on the surface barrier in magnetic field and without magnetic field were shown in figure 4. the plasma on surface barrier was sometimes clearly displayed or not clearly displayed for both models in magnetic field and without magnetic field. we attempted to take pictures until a half hour when the plasma progress on the surface barrier. in the investigation of surface barrier discharge, the development of plasma on surface barrier was unstable discharge. it was shown that plasma in the model with magnetic field was more luminous rather than without magnetic field as they were presented in figure 4 and figure 5. both plasmas progressed in the models with magnetic field and without magnetic field showed similar types of plasma as presented in figure 5. they produced many micro discharges at the end side of the circular electrode. the applied voltage that was connected to an anode electrode was maximum 5 kv and the frequency was 25 khz. the applied voltage and discharge current were sinusoidal waves. the development of plasma on the surface barrier in the model with magnetic field was started from zero to a positive half cycle of apply voltage and then, it also progressed at a half of negative cycle as shown in figure 6. there were many current pulses for both cycles. however, for the model ii, the current pulses occurred at both positive and negative cycles of apply voltage, refer to figure 7. the current pulses occurred at near end of a half cycle of apply voltage. there were no pulses at the maximum or minimum value of current. however, plasma progressed in the model with magnetic field (model i) contributed the current pulses at the maximum or minimum value of current, and after a quarter cycle of apply voltage, there were no pulses for both negative and positive cycles until the current figure 6. apply voltage and discharge current graphs in magnetic field 0 3 3 6 6 v o lt a g e ( k v ) 1.5 3.0 0 -1.5 -3.0 c u rre n t (m a ) 200 time (us) applied voltage 40 60 80 discharge current pulses generation figure 5. result of typical of plasma in magnetic field and without magnetic field 315 mt 0 mt figure. 4. result of surface barrier discharge in magnetic field and without magnetic field 0 mt315 mt f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 99 manages to zero. it also shown that the current amplitude for the model without magnetic field was higher than with magnetic field. the amplitude of current in the model without magnetic field was about twice of the current in the model with magnetic field. every current pulse corresponded to a series of micro discharges on the surface barrier material [7]. from figure 6, it could be concluded that the series of micro discharges in the model with magnetic field were released from a circular electrode at every quarter cycle of apply voltage. however, it was different to the series of micro discharges in the model without magnetic field, they have released almost a half cycle of apply voltage. u-q lissajous parallel diagram shapes for surface barrier discharge in the model without magnetic field and in the model with magnetic field was presented in figure 8. during the experiment, it was difficult to find stable area of lissajous figures for both models. the area always varied versus discharge times. however, the figures of lissajous were almost similar with many pulses. it was indicated that the lissajous figures that recorded by using a digital oscilloscope were the electrical discharge in air. the area lissajous for both were almost similar b. molecular dynamic simulation in order to study on ionized air, molecular dynamic can be used to understand the ionization process of the molecule. for the co2 molecule, the best pose selected was time value of 1,000 s, energy of 0.0502 kcal/mol, and a temperature of 120.440 k, respectively. like the other gas, the n2 molecule was seen to be stable for the ionization process. from the best poses, time value of 1,000 s, energy of 0.0526 kcal/mol, with a temperature figure 7. apply voltage and discharge current graphs without magnetic field 0 3 3 6 6 v o lt a g e ( k v ) 1.5 3.0 0 -1.5 -3.0 c u rre n t (m a ) 200 time (us) applied voltage 40 60 80 discharge current pulses generation (a) (b) figure 8. lissajous diagram for surface barrier discharge; (a) without magnetic field; (b) in magnetic field f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 100 of 205.949 k. based on the molecular dynamics results, the ionization process of molecule o2 occurred at the time value of 1,000, the energy of 0.430 kcal/mol, and a temperature of 0.0104. the ionization process in co2, n2 and o2 were presented in figures 9, 10, and 11, respectively. molecule co2 was seen to be able to ionize since this co2 molecule observed the energy and the lowest time, respectively. the pink dot was shown the stable condition of molecule co2. like the other gas, the n2 molecule was seen to be stable for the ionization process. likewise, in the case of gas o2, based on the figure 9. the ionization process of co2 molecule figure 10. the ionization process of n2 molecule f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 101 molecular dynamic results, it shown that the gas (o2) was ionized on time value of 1,000, energy of 0.430 kcal/mol. the simulation result in table 1 presented the ionization energy. it was shown that the ionization in n2 gas was easier than o2 gas. v. conclusion the effect of magnetic field for producing plasma on the surface barrier had a very detail difference with the surface barrier discharge without magnetic field. the current produced by the plasma progressed on surface barrier with magnetic field was lower than the current produced by the plasma progressed on surface barrier without magnetic field. the amplitude of current for the model i was almost a half of current for the model ii. there were many current pulses in the both models. these pulses indicated that micro discharges developed on the surface dielectric material for both of these models. the micro discharges in the model i occurred for a quarter cycle of apply voltage. however, it was different with the micro discharges in the model ii that was occurred almost of a half cycle of applied voltage. the plasma progressed on surface barrier in magnetic field was more luminous than the plasma progressed on surface barrier without magnetic field. the typical of micro plasma released from a circular electrode was similar for both plasma models. the typical lissajous figures for both models were similar with many pulses. it also can be concluded that the effect magnetic field will influence the plasma progress on the surface barrier. molecular dynamic can be used to understanding the ionization process of molecule. the ionization process can be obtained by using the energy ionization. the ionization in n2 gas was easier than o2 gas. acknowledgement we thanks kementerian ristek-dikti for financial support through penelitian produk terapan 2017. references [1] n. osawa et al., “investigation on reactor configuration of nonthermal plasma catalityc hybrid method for nox removal of diesel engine exhaust”, international journal of plasma and enviromental science and technology, vol. 6, no.2, september 2012. [2] k. shimizu et al., “water treatment by low voltage discharge in water”, international journal of plasma and enviromental science and technology, vol. 4, no.1, march 2010. [3] ayman a.a et al., “influence of applied voltage waveforms on the performance of surface dielectric barrier discharge reactor for decomposition of naphthalene”, journal of physics d: applied physics, vol. 48, no. 19, 2015. [4] ayman a.a, et al.,” influence of nitrogen excited species on the destruction of naphthalene in nitrogen and air using surface dielectric barrier discharge,” journal of hazardous materials 246-247, december 2012, c:26-33 · [5] p. lukes et al., “pulsed electrica discharge in water generated using porous-ceramic-coated electrodes”, ieee transactions on plasma science, vol. 36, no. 4, august 2008 figure 11. the ionization process of o2 molecule table 1. simulation result gases energy (kcal/mol) co2 0.0502 n2 0.0526 o2 0.430 http://www.iesj.org/service/ijpest/13/8 http://www.iesj.org/service/ijpest/13/8 http://www.iesj.org/service/ijpest/13/8 http://www.iesj.org/service/ijpest/13/8 http://www.iesj.org/service/ijpest/13/8 http://www.iesj.org/content/files/pdf/ijpest_vol4_no1_09_pp058-064.pdf http://www.iesj.org/content/files/pdf/ijpest_vol4_no1_09_pp058-064.pdf http://www.iesj.org/content/files/pdf/ijpest_vol4_no1_09_pp058-064.pdf https://doi.org/10.1088/0022-3727/48/19/195201 https://doi.org/10.1088/0022-3727/48/19/195201 https://doi.org/10.1088/0022-3727/48/19/195201 https://doi.org/10.1088/0022-3727/48/19/195201 https://doi.org/10.1016/j.jhazmat.2012.12.005 https://doi.org/10.1016/j.jhazmat.2012.12.005 https://doi.org/10.1016/j.jhazmat.2012.12.005 https://doi.org/10.1016/j.jhazmat.2012.12.005 https://doi.org/10.1109/tps.2008.920945 https://doi.org/10.1109/tps.2008.920945 https://doi.org/10.1109/tps.2008.920945 f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 95–102 102 [6] j. chen and p. wang, “effect of relative humidity on electron distribution and ozone production by dc coronas in air,” ieee transactions on plasma science, vol. 33, , 2005, pp.808812. [7] h.-e. wagner et al., ”the barrier discharge: basic properties and applications to surface treatment”, vacuum, vol. 71, issue 3, 19 may 2003, pages 417–436 [8] z. salam et al., "transformerless power supply based on single switch resonant inverter for ozone generation," 2013 twentyeighth annual ieee applied power electronics conference and exposition (apec), long beach, ca, usa, 2013, pp. 3330-3333. [9] c. yong-nong and k. chih-ming, “design of plasma generator driven by high-frequency high-voltage power supply”, journal of applied research and technology, vol. 11, 2013, pp.225-234. [10] v. j. law et al., ” handheld flyback driven coaxial dielectric barrier discharge: development and characterization”, review of scientific instruments, vol. 79, issue 9, 2008. [11] t.c. manley, “the electric characteristics of the ozonator discharge”, j. electrochem. soc. 1943 vol. 84, issue 1, 83-96. [12] f. murdiya et al., "creeping discharge developing on vegetablebased oil / pressboard interface under ac voltage," in ieee transactions on dielectrics and electrical insulation, vol. 21, no. 5, 2014, pp. 2102-2110. [13] j.y park et al., ”nox removal using dc corona discharge with magnetic field”combustion science and technology, vol. 133 issue 1-3, 1998, pp. 65-77, taylor & francis [14] s. pekarek “experimental study of nitrogen oxides and ozone generation by corona-like dielectric barrier discharge with airflow in a magnetic field”. plasma chem plasma process, vol. 37, 2017, pp. 1313–1330, springer [15] y. liu et al., “ the impacts of magnetic field on repetitive nanosecond pulsed dielectric barrier discharge in air “, physic of plasmas, vol. 23, 2016. [16] m. j. uline and d. s. corti, “molecular dynamics at constant pressure: allowing the system to control volume fluctuations via a “shell” particle”. entropy 2013, 15, 3941-3969. [17] h. h. rugh, “dynamical approach to temperature”. phys. rev. lett. 1997, 78, 772–774. [18] o. g. jepps et al., “microscopic expressions for the thermodynamic temperature”. phys. rev. e. 2000, 62, 4757– 4763. [19] k. p. travis and c. braga, “configurational temperature and pressure molecular dynamics: review of current methodology and applications to the shear flow of a simple fluid”. mol. phys. 2006, 104, 3735–3749. https://doi.org/10.1109/tps.2005.844530 https://doi.org/10.1109/tps.2005.844530 https://doi.org/10.1109/tps.2005.844530 https://doi.org/10.1109/tps.2005.844530 https://doi.org/10.1016/s0042-207x(02)00765-0 https://doi.org/10.1016/s0042-207x(02)00765-0 https://doi.org/10.1016/s0042-207x(02)00765-0 https://doi.org/10.1109/apec.2013.6520779 https://doi.org/10.1109/apec.2013.6520779 https://doi.org/10.1109/apec.2013.6520779 https://doi.org/10.1109/apec.2013.6520779 https://doi.org/10.1109/apec.2013.6520779 https://doi.org/10.1016/s1665-6423(13)71532-3 https://doi.org/10.1016/s1665-6423(13)71532-3 https://doi.org/10.1016/s1665-6423(13)71532-3 https://doi.org/10.1016/s1665-6423(13)71532-3 https://doi.org/10.1063/1.2988833 https://doi.org/10.1063/1.2988833 https://doi.org/10.1063/1.2988833 https://doi.org/10.1149/1.3071556 https://doi.org/10.1149/1.3071556 https://doi.org/10.1109/tdei.2014.004569 https://doi.org/10.1109/tdei.2014.004569 https://doi.org/10.1109/tdei.2014.004569 https://doi.org/10.1109/tdei.2014.004569 https://doi.org/10.1080/00102209808952027 https://doi.org/10.1080/00102209808952027 https://doi.org/10.1080/00102209808952027 https://doi.org/10.1007/s11090-017-9831-9 https://doi.org/10.1007/s11090-017-9831-9 https://doi.org/10.1007/s11090-017-9831-9 https://doi.org/10.1007/s11090-017-9831-9 https://doi.org/10.1063/1.4968233 https://doi.org/10.1063/1.4968233 https://doi.org/10.1063/1.4968233 http://dx.doi.org/10.3390/e15093941 http://dx.doi.org/10.3390/e15093941 http://dx.doi.org/10.3390/e15093941 https://doi.org/10.1103/physrevlett.78.772 https://doi.org/10.1103/physrevlett.78.772 https://doi.org/10.1103/physreve.62.4757 https://doi.org/10.1103/physreve.62.4757 https://doi.org/10.1103/physreve.62.4757 https://doi.org/10.1080/00268970601014880 https://doi.org/10.1080/00268970601014880 https://doi.org/10.1080/00268970601014880 https://doi.org/10.1080/00268970601014880 mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology volume 07, 2016 authors index achmad praptijanto, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 adelhard beni reihara, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 adi soeprijanto, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 adnan rafi al tahtawi, "simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose," 07(2): 77-86 ahmad e. esmaio, "derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses," 07(2): 67-76 andrew j. day, "modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake," 07(1): 49-56 anh-huy vo, "nonlinear tracking control of a 3-d overhead crane with friction and payload compensations," 07(1): 27-34 arief syaichu rohman, "simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose," 07(2): 77-86 arifin nur, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 bambang wahono, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 didin saefudin, "hardware simulation of automatic braking system based on fuzzy logic control," 07(1): 1-6 edwar yazid, "application of empirical mode decomposition method for characterization of random vibration signals," 07(1): 21-26 estiko rijanto, "accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator," 07(2): 105-112 ha-quang-thinh ngo, "nonlinear tracking control of a 3-d overhead crane with friction and payload compensations," 07(1): 27-34 hasan m.s. atia, "derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses," 07(2): 67-76 hendri maja saputra, "accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator," 07(2): 105-112 herlambang setiadi, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi imam wahyudi farid, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 kadek heri sanjaya, "review on the application of physiological and biomechanical measurement methods in driving fatigue detection," 07(1): 35-48 karar mahmoud, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 khallid hussain, "modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake," 07(1): 49-56 kuspriyanto, "hardware simulation of automatic braking system based on fuzzy logic control," 07(1): 1-6 liana ellen taylor, "optimized object tracking technique using kalman filter," 07(1): 57-66 maher a.r. sadiq al-baghdadi, "a cfd model for analysis of performance, water and thermal distribution, and mechanical related failure in pem fuel cells," 07(1): 7-20 matthias günther, "a hybrid pv-battery/diesel electricity supply on peucang island: an economic evaluation," 07(2): 113-122 midriem mirdanies, "accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator," 07(2): 105-112 midriem mirdanies, "optimized object tracking technique using kalman filter," 07(1): 57-66 miftahul anwar, "derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses," 07(2): 67-76 mohamed milad baiek, "derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses," 07(2): 67-76 muhammad abdillah, "optimal selection of lqr parameter using ais for lfc in a multi-area power system," 07(2): 93-104 muhammad nizam, "derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses," 07(2): 67-76 noor cholis basjaruddin, "hardware simulation of automatic braking system based on fuzzy logic control," 07(1): 1-6 quoc-chi nguyen, "nonlinear tracking control of a 3-d overhead crane with friction and payload compensations," 07(1): 27-34 quoc-toan truong, "nonlinear tracking control of a 3-d overhead crane with friction and payload compensations," 07(1): 27-34 roni permana saputra, "optimized object tracking technique using kalman filter," 07(1): 57-66 setyamartana parman, "application of empirical mode decomposition method for characterization of random vibration signals," 07(1): 21-26 soomin lee, "review on the application of physiological and biomechanical measurement methods in driving fatigue detection," 07(1): 35-48 suhendar, "hardware simulation of automatic braking system based on fuzzy logic control," 07(1): 1-6 suherman, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 tetsuo katsuura, "review on the application of physiological and biomechanical measurement methods in driving fatigue detection," 07(1): 35-48 virna apriani azis, "hardware simulation of automatic braking system based on fuzzy logic control," 07(1): 1-6 widodo budi santoso, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii zaini dalimus, "modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake," 07(1): 49-56 zong lu, "fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine," 07(2): 87-92 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii journal of mechatronics, electrical power, and vehicular technology volume 07, 2016 affiliation index brother industries, ltd., nagoya, japan 87 center for environment, health, and field sciences, chiba university, chiba prefecture, japan 35 control and automation laboratory, ho chi minh city university of technology, ho chi minh city, vietnam 27 department of computer engineering, politeknik sukabumi, sukabumi, indonesia 77 department of cybernetics, graduate school of engineering, hiroshima university, hiroshima, japan 93 department of electrical engineering, institut teknologi sepuluh nopember, surabaya, indonesia 93 department of electrical engineering, politeknik negeri bandung, bandung, indonesia 1 department of electrical engineering, university of bhayangkara, surabaya, indonesia 93 department of electrical engineering, university of papua, manokwari, indonesia 93 department of mechanical engineering, faculty of engineering, university of kufa, najaf, kufa, iraq 7 department of mechatronics, ho chi minh city university of technology, ho chi minh city, vietnam 27 electrical engineering department, andalas university, padang, indonesia 49 faculty of engineering, aswan university, aswan, egypt 93 general electricity company of libya (gecol), tripoli, libya 67 graduate school of mechanical engineering, university of ulsan, ulsan, republic of korea 87 humanomics laboratory, graduate school of engineering, chiba university, chiba-shi, japan 35 laboratory for control and computer systems, institut teknologi bandung, bandung, indonesia 77 mechanical engineering departement, universiti teknologi petronas, perak, malaysia 21 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix postgraduate program, mechanical engineering department, sebelas maret university, surakarta, indonesia 67 research centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia 21, 35, 57, 87, 105 research center for renewable energy and energy efficiency, swiss german university, tangerang, indonesia 113 school of electrical engineering and informatics, institut teknologi bandung, bandung, indonesia 1 school of engineering and information technology -university of new south wales (unsw), canberra, australia 57 school of engineering, design and technology, university of bradford, united kingdom 49 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. ir. suhono h supangkat, m.eng, cgeit. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. dr. ir. zainal abidin mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. iman k reksowardojo mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135 indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia ir. edi leksono, m.eng, ph.d. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. arjon turnip technical management unit for instrumentation development lipi komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2ndfl, bandung 40135, indonesia dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. sunit hendrana research center for physics lipi komp lipi jl sangkuriang, blg 60, 2nd fl, bandung 40135, indonesia dr. ary setijadi prihatmanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. adi soeprijanto, mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. ir. feri yusivar, m.eng department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr. agus purwadi school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, st., mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research center for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with semi colon and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev j. mechatron. electr. power veh. technol. 07 (2016) 113-122 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.113-122. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. a hybrid pv-battery/diesel electricity supply on peucang island: an economic evaluation matthias günther * research center for renewable energy and energy efficiency, swiss german university edutown, bsd, 15339 tangerang, indonesia received 17 may 2016; received in revised form 19 october 2016; accepted 04 november 2016 published online 23 december 2016 abstract renewable energy technologies are currently under a dynamic cost development. this case holds especially for solar technology that has reached price levels that were unimaginable until a short time ago. it also holds for battery technologies the application of which is related to the increasing usage of photovoltaic energy converters and the growing interest in electric vehicles. with the decreasing prices more and more possible application cases of renewable energy technologies become economically viable. a case study was done for a location on a small island located on the west tip of java. the levelized electricity cost of a hybrid electricity supply system composed of a solar generator and battery in combination with the existing diesel generators was compared to the electricity generation cost of the existing system. two different battery options were taken into account, lead-acid batteries and lithium-ion batteries. the results of this study can give a rough orientation also for other locations with similar characteristics. keywords: hybrid electricity supply; photovoltaics; lead-acid battery; lithium-ion battery; peucang island. i. introduction the discontinuous geography of indonesia implies that many parts of the country are not and cannot be connected to the large electricity supply grids. the only option is then the installation of small decentralized energy supply and distribution systems. most of the existing small systems are diesel-based. years ago diesel gensets were the most economically competitive decentralized energy generation technology, especially at locations where no hydropower potential is given. diesel gensets require the lowest investment among the different existing options, and even if their operation comes with continuous fuel costs, they were the preferred technology for decentralized electricity supply systems. by now, however, several renewable energy technologies have become more costefficient. additionally, the fuel prices have the tendency to increase. the latter holds even if the prices are quite low at the moment; in the long run, they will rise again. therefore, more and more economically viable application opportunities for renewable energy systems appear. in many cases, small hydropower stations, wind turbines, and solar photovoltaic (pv) systems have been integrated into small supply systems or even constitute the sole electricity generation basis. also in indonesia, many systems have been installed in the last years (see interactive map of renewable energy projects in indonesia [1]). indeed, renewable energy solutions (besides hydropower) have not only become competitive for off-grid applications [2], which this study concentrates on, but also for ongrid systems [3]. the present study examines the economic viability of the installation of a hybrid pv-battery or diesel electricity supply system at a typical off-grid location on an indonesian island. the economic viability of the hybrid system is evaluated in comparison to the further exclusive usage of the existing diesel-genset infrastructure. additionally, the present study inquires the economic competitiveness of two different battery options, namely lead-acid batteries and lithium-ion batteries. currently, most existing * corresponding author.tel: +62-21-30450045 e-mail: matthias.guenther@sgu.ac.id http://dx.doi.org/10.14203/j.mev.2016.v7.113-122 m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 114 systems contain lead-acid batteries, which are the cheapest in terms of investment costs. however, over the past years, lithium-ion batteries have become more cost-efficient even if they still require considerably higher investment costs than lead-acid batteries. it has already been argued that the better performance of lithium-ion batteries should be sufficient to result in lower costs of ownership compared to lead-acid batteries, especially under hot climate conditions [4]. the present study also has the objective to scrutinize this claim besides evaluating the economic viability of the operation of a solar/hybrid diesel system at the given location. the studied site is located on peucang island in the national park ujung kulon at the west tip of java. this national park contains the largest remaining lowland rainforest on java and is especially known for being the last refuge for the critically endangered javan rhinoceros. the small peucang island hosts a national park post and a touristic resort. due to its remoteness, it is not connected to any grid operated by the state electricity company (pt. pln), and a future grid connection is not to be expected. currently, the electricity needs on peucang island are covered by diesel generators. the diesel fuel has to be transported by boats from the village sumur, which is located at a distance of about 40 km. figure 1 shows the geographical situation of peucang island and the village sumur. figure 2 shows a map of the studied site specifying the different buildings and other facilities, some of which belong to the touristic resort while others belong to the national park. according to national park and resort employees, the cost of the fuel delivered to peucang island to power the diesel gensets is about 15,000 idr (about 1.14 usd) per litre, which is about the double of the cost in urban centers. with this high fuel cost, the installation of an alternative renewable source-based electricity supply system is economically promising. the annual sum of global horizontal radiation on peucang amounts to 1,751 kwh/m2 (meteorological data are acquired from meteonorm [5]). as to be seen in figure 3, the radiation is quite evenly distributed over the year. these are favourable conditions for an effective usage of a photovoltaic system. the temperature on peucang island fluctuates within quite a narrow range around an average value of about 28°c. the ambient temperature is an important parameter for the performance of the pv generator as well as of the batteries. ii. research method the first step was a site visit to peucang island, realized in october 2015. the aim of the visit was the registration of the load and energy consumption of the existing electrical consumers and an estimation of their future usage including possible additional future consumers. additionally, the currently existing electricity supply infrastructure was analysed. it was planned from the outset to make use of the existing infrastructure also for the future supply figure 3. daily global horizontal radiation sums during one year figure 1. geographical situation of the site (source: google earth) figure 2. sitemap. 1: national park information center, 2: barracks for national park employees, 3: mosque, 4: building fauna, 5: building flora a, 6:building flora b, 7: restaurant, 8: resort information center, 9: barracks for resort employees, 10: service rooms, 11: jetty, 12 a – d: water wells, 13 a – c: water tanks, 14 a – c: diesel generators, 15: radio communication tower, 16: telkomsel antenna, 17: helipad (source: own design based on google earth) m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 115 system. in particular, the existing diesel generator and the distribution network should be used in the future electricity supply system. the second step was the design of a consumption scenario for the location. a growing number of tourists were taken into account as well as some seasonal fluctuations. the third step was the technical design of the hybrid electricity supply system. the system is based on the developed load profile and integrates the existing diesel generator infrastructure. finally, an economic evaluation of the proposed system (and its different versions) was done. the levelized cost of electricity (lcoe) was taken as the main economic parameter. the system is considered to be economically competitive if its lcoe is lower than the lcoe of the existing system, which is taken as a reference system. the existing system consists basically of a 24 kva diesel generator and two small 2.8 kva generators for emergency applications. the levelized cost of electricity of an electricity generation system is the ratio of the costs that incur during the system lifetime (discounted according to the year they incur) to the produced energy (discounted according to the year it is generated): 𝐿𝐶𝑂𝐸 = ∑ 𝐼𝑡+𝑀𝑡+𝐹𝑡 (1+𝑖)𝑡 𝑛 𝑡=1 ∑ 𝐸𝑡 (1+𝑖)𝑡 𝑛 𝑡=1 (1) where 𝐼𝑡 is investment in year t, 𝑀𝑡 is operation and maintenance cost in year t, 𝐹𝑡 is fuel cost in year t, 𝐸𝑡 is energy yield in year t, 𝑖 is discount rate, and 𝑛 is system lifetime. in our case, 𝑀𝑡, 𝐹𝑡, and 𝐸𝑡 are considered to be constant for each year so that they can be substituted by annual amounts 𝑀𝑦 , 𝐹𝑦 , and 𝐸𝑦 . the investment is done principally in the year 0, but additional investments are done during the system lifetime due to the necessary renovation of the battery system. taking into account additionally that ∑ 1 (1+𝑖)𝑡 𝑛 𝑡=1 = (1+𝑖)𝑛−1 (1+𝑖)𝑛∙1 , the lcoe equation can be simplified then to: 𝐿𝐶𝑂𝐸 = ∑ 𝐼𝑡 (1+𝑟)𝑡 𝑛 𝑡=1 𝐸𝑦 (1+𝑖)𝑛−1 (1+𝑖)𝑛∙1 + 𝑀𝑦+𝐹𝑦 𝐸𝑦 (2) for the reference system, i.e. the existing system, based exclusively on the existing diesel gensets, no investment was taken into account so that the equation for that system can be simplified to: 𝐿𝐶𝑂𝐸 = 𝑀𝑦+𝐹𝑦 𝐸𝑦 (3) the calculations were done with lead-acid batteries as well as with lithium-ion batteries. additionally to the lcoe, which is considered the main economical parameter, the payback time with respect to the further usage of the dieselonly system was calculated. a discount rate of 3% was chosen. the operation and maintenance costs were considered to be 3 usct/kwh. for the reference system operation and maintenance costs of 4 usct/kwh were assumed based on [6] and [7]. for the calculation of the lcoe, a system lifetime of 25 years was assumed, except for the batteries the lifetime of which was treated separately. the battery lifetime is one of the most important parameters that determine the electricity costs because the battery is the most expensive component of the system. for the lead-acid batteries, the lifetime was determined in accordance with typical cycle lifetimes of these batteries taking into account depth of discharge and temperature (for different lifetime calculation methods, see [8]). for depths of discharge until 10%, and for a temperature of 25°c, a cycle lifetime of 10,000 was considered, for depths of discharge between 10 and 20% about 6,000 cycles, etc. until below 2,000 cycles for a depth of discharge of 80% [9]. for each charge cycle the respective lifetime loss is taken into account (e.g. 0.0001 lifetimes if a depth of discharge of 10% is reached). in the case of a battery room without an additional cooling and hence with an average temperature around 30 to 32°c, the respective lifetime loss is increased by a factor of 1.5 with respect to the lifetime loss at 25°c [10]. for the lithium-ion batteries, the lifetime was determined in accordance with the warranties given by the manufacturers. the system modelling was done for one year, and with an hourly resolution. consumption time series were designed on the basis of the existing infrastructure, on the basis of assumptions about future tourist numbers, and on the basis of assumptions about future electrical consumers and their usage. generation time series were designed on the basis of meteorological data and in dependence on respective system configurations (installed pv, diesel and battery capacities, pv module orientation and shading conditions, etc.). iii. result a. consumption scenario the consumption scenario includes assumptions about the future number of tourists, about the number of employees on site, and about the type and number of electrical consumers and their usage. the resort is assumed to be fully m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 116 booked, with a maximum visitor number of 50, on the weekends in the dry season between may and october. for the rest of the days, and especially in the rainy season, lower numbers of visitors are considered. the national park has eight staff members on peucang, and the resort has ten staff members in the low season and 12 staff members in the high season. the electrical consumers are the currently existing ones including some additional consumers that are assumed to be added. based on these assumptions standard low-season and highseason consumption weeks were defined, the load curves of which are represented in figure 4. according to this scenario, the peak load is 5,068 w in the low season and 7,828 w in the high season. the consumption is 308 kwh in a low-season week and 422 kwh in a high-season week. the dominating electrical consumers are the fans in the resort rooms and other locations. the sharp peaks in the load curves reflect the increased usage of the fans in the resort rooms in the late afternoon and during the night. this scenario does not yet include battery room cooling. if battery room cooling with an assumed permanent additional load of 300 w is taken into account, the peak load would be 5,368 w in the low season and 8,128 w in the high season. the consumption would be 358 kwh in a low-season week and 472 kwh in a high-season week. b. design of the proposed electricity supply system figure 5 shows the general design of the proposed hybrid system. it is a three-phase ac system. a so-called multicluster box from sma/germany [11], represented as the boxes in the center, serves as interconnection of the main system components, i.e. the inverter that converts the dc from the pv generator to three-phase ac (top), the bidirectional inverters for battery connection (bottom), the diesel genset (left), and the grid (right). the operational logic is roughly the following: an existing power demand is covered by pv electricity whenever it is available. if the pv electricity is insufficient, the needed electricity is taken from the batteries. if the batteries reach their maximum depth of discharge (80% for lead-acid batteries, and 90% for lithium-ion batteries), the diesel generator starts and runs until the batteries are fully charged. c. economic evaluation and system dimensioning for a system with lead-acid batteries the system was modelled according to the climatic conditions, the consumption scenario, and the possible location of the pv panels. the most appropriate locations for the pv generator are the northeast facing flat roofs of the two buildings flora a and flora b (see figure 2, buildings 5 and 6). these large roofs allow the installation of up to more than 15 kwp on each one. some shading has to be taken into account in the late afternoon when the trees behind the buildings and the roofs themselves cast a shadow onto the pv modules (figure 6). in a first step, an economic analysis was done under the condition that the lead-acid batteries are located in a figure 6. resort building flora a the large flat roof of which is one of the preferred pv locations figure 4. consumption scenario for a high-season week (top) and a low-season week (bottom) figure 5. system structure m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 117 naturally ventilated battery room without additional cooling. the maximum depth of discharge was fixed at 80%. in jakarta, the cost of the most economic valve-regulated sealed lead-acid batteries, appropriate for solar applications, is about 220 usd/kwh [12]. the installed pv capacity, as well as the installed battery capacity, was varied, and the resulting total lcoe were calculated. the result of this calculation is represented in figure 7, which shows the lcoe in dependence on the installed pv capacity and the installed battery capacity. as to be seen in figure 7, the lowest lcoe is reached for battery capacities between 90 and 130 kwh and a very broad range of installed pv capacities between 20 and 32 kwp. for these system dimensions, the lcoe are around 48 to 49 usct/kwh. taking into account the characteristics of the northeast oriented roofs of the resort buildings flora a and b, and respecting some aesthetic considerations concerning the covering of these roofs with pv modules, the following system dimensioning can be selected: on each of the two roofs 36 pv modules a 300 wp with a size of 1 m x 2 m are installed, which results in a total installed pv capacity of 21.6 kwp. figure 8 gives a visual impression of the coverage of the roofs with this number of modules. the battery capacity amounts to 95 kwh. the daily reached a depth of discharge is 30 to 60% in the low season and 50 to 75% in the high season. figure 9 shows the depths of discharge, ordered by magnitude, that are reached during the days of the model year. the charge state of the battery comes very seldom close to the maximum depth of discharge of 80%. this cycle behavior and an assumed battery room temperature of 30 to 32°c render a battery lifetime of about four years and one month. the lcoe for this system is about 48 usct/kwh, compared to about 98 usct/kwh for the existing diesel-only system (for the same consumption scenario). the payback time with respect to the usage of the reference system is about four years. ninety four percent of the consumed electrical energy is delivered by the solar generator, only six percent is delivered by the diesel generator. the first main result is, hence, that the investment in a solar generator would be highly profitable for the selected location under the assumed consumption conditions. the short payback time of only four years is most of all a result of the high fuel prices of 15,000 idr per litre. additionally, it has to be taken into consideration that the diesel generator works under very unfavourable part-load conditions if used to cover the load directly. the load is permanently quite far below the rated power of the used diesel generator (24 kva), which diminishes the efficiency of the generator quite drastically. both, the high diesel price and the unfavourable part-load operation of the diesel generator, provoke the high lcoe of the reference system of 98 usct/kwh. if the generator is used to charge the batteries instead figure 8. 2x36x300 wp distributed on flora a (left) and on flora b (right) figure 7. lcoe in dependence on the installed battery capacity and the installed pv capacity m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 118 of powering the consumers directly, it can be operated closer to its nameplate power and, hence, with a considerably higher efficiency. this difference in the diesel genset efficiency contributes to the large difference between the lcoe of the hybrid system and the lcoe of the reference system. and it contributes to the quite short payback time of the investment of about 70,000 usd that has to be done to buy the components of the proposed system and to install the system on peucang. the investment costs are calculated according to information from jakartabased senior advisor for renewable energies dipl.-ing. horst kruse and refer to the year 2015 (pv panel prices dropped further in 2016 so that the investment would be slightly lower if calculated for the moment of publication). until this point, the system was evaluated without considering a possible battery room cooling. the installation of a battery room cooling has the advantage to increase the battery lifetime. as the battery is the most expensive component of the system, a higher battery lifetime can be a useful lever to reduce the lcoe. the downside is that the battery room cooling increases the power consumption in the grid and that it requires a small additional investment for the air conditioner and possibly for the appropriate adaptation of the battery room (the additional investment is taken to be 2000 usd). the battery room is supposed to be maintained at 25°c, which is assumed to be achieved with a permanently running air conditioning device with a power of 300 w. according to the simulation, the economic optimum configuration is reached with a pv capacity of 26 kwp and a battery capacity of 105 kwh. the battery lifetime increases from 4 years and one month to 6 years and six months. the lcoe drops from 48 usct/kwh to 42 usct/kwh. so the installation of a battery room cooling is a profitable additional investment. table 1 compares some key numbers of the two configurations, i.e. the configuration without battery room cooling and the configuration with a cooled battery room. d. comparison to lithium-ion batteries lithium-ion batteries are mostly considered as too expensive for solar applications. however, prices of lithium-ion batteries are dropping currently, which requires a new evaluation of the economic competitiveness of these batteries with respect to lead-acid batteries. most probably lithium-ion battery prices will continue to drop given that there are important battery market drivers, in particular e-mobility. the prospects of this technology are positive [13]. lithium-ion batteries have some technical and operational advantages over lead-acid batteries. the most important for mobile applications is the higher energy density. lithium-ion batteries are lighter and smaller than lead-acid batteries with the same capacity. this advantage, however, is not so important for stationary applications like the one on peucang island. what is more important for stationary applications is that the still higher prices of lithium-ion batteries may be offset by the higher cycle lifetime, by larger discharge depths without losing as much lifetime as lead-acid batteries,by higher cycle efficiencies, by a more constant voltage level over a charge cycle, and by a better tolerance of higher temperatures [14]. additionally, the capacity is less affected by the discharge rate. currently, table 1. key numbers for the systems with lead-acid battery with and without battery room cooling item no battery room cooling battery room cooling unit pv capacity 21.6 26 kwp installed battery capacity 95 105 kwh lcoe 48 42 usct/kwh payback time 4.0 4.5 years battery lifetime 4.2 6.5 years diesel consumption 410 (=2.5% of the diesel consumption in the reference system) 340 (=2.1%) l/year figure 9. depths of daily discharge of the battery reached during the model year, ordered by magnitude m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 119 small lithium-ion battery systems for home applications cost 1,600 to 2,200 usd/kwh [15]. these costs are generally too high to be competitive with lead-acid batteries. larger batteries have lower specific costs. in 2015, the best offer identified in jakarta for a stationary lithium-ion battery with capacities that are needed in peucang was 900 usd/kwh (based on the ex-factory price in this case in germany [16] taking into account some additional transport costs). the further cost reduction potential of lithium-ion batteries is considered to be high. lithium-ion battery prices are expected to fall to 200 usd/kwh by 2020 and to even lower prices in the more remote future [17]. the battery manufacturer tesla announced in 2015 the market entry of the so called powerwall, a stationary lithium-ion battery for solar home systems for a price of 350 usd/kwh. for now, this is only an announcement; the storage is not yet in the market. but even if the price of the battery systems should be a bit higher at the end, lithium-ion battery systems with a price level close to the announced level will have the potential to change the energy storage market situation considerably. pv-battery home systems will become economically competitive in many countries, and in many applications, lead-acid batteries may be substituted by lithium-ion batteries. the mentioned offered lithium-ion battery system for the stationary application on peucang, for a price of about 900 usd/kwh, is still considerably more expensive than the lead-acid batteries, which can be purchased at 220 usd/kwh. taking into account the better performance of lithium-ion batteries and the longer lifetime, the question comes up whether this price is already sufficiently low to make them competitive in the sense of allowing lower lcoe of the hybrid system on peucang. to answer this question, the following assumptions are made: the batteries are located in a climatised room with a constant temperature of 25°c, which is in the range of the optimum operating temperature with respect to cycle lifetime [18]. a maximum depth of discharge of 90% is defined. at a reasonable battery size, this depth of discharge is reached only exceptionally (compare figure 9). the mentioned battery offer includes a 10-year warranty for 50% of the nominal capacity for 8,000 cycles with a depth of discharge of 70% or 5,000 cycles with a depth of discharge of 90%. as a system lifetime of 25 years is assumed, it seems plausible to assume one battery exchange during the system lifetime. if the battery exchange is located in the middle of the system lifetime, i.e. in the 13th year, then about 4,500 cycles are assumed for one battery system. for the selected system dimensions the depth of discharge is mostly 50 to 60% in the low season and 70 to 80% in the high season. with these generally quite low depths of discharge, and taking into account the warranty conditions, the assumption of a battery lifetime of 12.5 years is quite conservative. additionally, we assume that the price for the replacement battery in the 13th year is the same as the price for the first battery, which makes our calculation even more conservative taking into account the positive price expectations for lithium-ion batteries. as the lithium-ion battery is more expensive than the lead-acid battery (and the maximum depth of discharge is deeper than for the leadacid battery) it can be expected, for the economical optimum configuration, that the installed battery should be smaller than for the lead-acid battery version. the simulation renders the following optimum system dimensioning: the pv capacity is 30 kwp and the battery capacity is 70 kwh. the resulting lcoe is 55 usct/kwh. the payback time with respect to the usage of the reference system amounts to 7 years and one month. in this system, 88% of the power is delivered from the solar generator and 12% from the diesel generator. the result is, hence, that the lcoe using the offered lithium-ion batteries (under the mentioned very conservative assumptions) is higher than the lcoe using lead-acid batteries. under the mentioned assumptions and for the specifically considered battery offers the lithiumion batteries are not yet economically competitive with the considered system on peucang island. taking into account that the assumed 12.5 years lifetime of the battery implies only around 4,500 cycles, most of which do not reach deep depths of discharge, it seems reasonable to consider additionally a slightly more ambitious battery scenario in which the batteries have a lifetime of 15 years (so that the second battery set has a residual value of one third of the replacement value at the end of the total system lifetime of 25 years). in this case, the lcoe drops to 51 usct/kwh (compared to the 55 usct/kwh for a battery lifetime of 12.5 years). however, the lcoe for the system with leadacid batteries is still lower. table 2 shows some key numbers of the systems with lithium-ion batteries in comparison to the system with leadacid batteries in a cooled battery room. even for the more ambitious scenario, according to which the battery lifetime is 15 years, the lcoe of the m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 120 system with lithium-ion batteries is still higher than for the system with lead-acid batteries. therefore it is interesting to know, finally, what price lithium-ion batteries should have in order to reach the lcoe of the systems with lead-acid batteries, i.e. 42 usct/kwh. the results of the respective simulations are the following: at an assumed lifetime of 12.5 years the lithium-ion batteries must reach a price of 425 usd/kwh. if the lifetime is 15 years, a battery price of 490 usd/kwh is already sufficient to reach the same lcoe as the system with the lead-acid batteries. table 3 shows some key numbers of the respective optimized systems in comparison to the lead-acid battery system in a cooled battery room. the calculated prices of lithium-ion batteries that are sufficient to make them competitive with lead-acid batteries for the studied system allow the following conclusion: although lithium-ion batteries are still too expensive to make the stationary system on peucang island even more cost-efficient than lead-acid batteries, the shortto-medium-term prospective of lithium-ion batteries is positive. taking into account the mentioned price expectations the calculated prices should be achievable in the near future. the prices that are the threshold for the economically reasonable application of lithiumion batteries are well above the announced future battery prices. it can be expected, therefore, that lithium-ion batteries will become soon an economically competitive option for stationary electricity supply systems like the one on peucang island. iv. conclusion in this study, a typical off-grid location was considered with the aim to figure out, first, whether the investment in a hybrid electricity supply system is economically feasible, and, second, whether lithium-ion batteries have already reached sufficiently low prices to compete with traditional solar lead-acid batteries under the circumstances of the considered location. the answer to the first question is positive: the investment in a complementing solar system makes sense; the lcoe can be reduced considerably to less than half of the high lcoe that have to be covered with the current diesel-based system. the answer to the second question is negative: the lithium-ion batteries (at least the batteries considered in this study) are still too expensive. however, there is a positive outlook; the price expectations of lithium-ion batteries are such that the competitive situation should change in the near future. if lithium-ion batteries reach the low costs that are announced by renowned manufacturers, then these batteries will be able to substitute lead-acid batteries in many applications. the price threshold for systems like the studied one on peucang island is located around 425 to 490 usd/kwh. from this price level on the higher investment (in comparison to lead-acid batteries, which cost about half of this price) is compensated by the longer lifetime of lithium-ion batteries and their table 2. key numbers for the systems with lithium-ion battery in comparison to the system with lead-acid battery item lead-acid 220 usd/kwh lithium-ion 900 usd/kwh unit 12.5 years lifetime 15 years lifetime pv capacity 26 30 30 kwp installed battery capacity 105 70 70 kwh max. dod 80 90 90 % lcoe 42 55 51 usct/kwh payback time 4.5 7.0 7.0 years battery lifetime 6.5 12.5 15 years diesel cons. 339 (= 2.1%) 930 (= 5.7%) 930 (= 5.7%) l/year table 3. key numbers for systems with lithium-ion battery at specific investment costs that make them competitive with lead-acid batteries item lead-acid batteries (with cooling) lithium-ion batteries unit 12.5 years lifetime 15 years lifetime pv capacity 26 28 30 kwp installed battery capacity 105 70 70 kwh max. dod 80 90 90 % lcoe 42 42 42 usct/ kwh battery price 220 425 490 usd/ kwh payback time 4.5 5.4 5.7 years battery lifetime 6.5 12.5 15 years diesel cons. 339 (=2.1%) 1040 (=6.4%) 930 (=5.7%) l/year m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 121 better performance. the results of this study hold first of all for the selected location on peucang island. but in principle, they can be taken into account for any location with similar characteristics. however, as no site is the same as the studied one, additional considerations will always be indispensable. acknowledgement i would like to express my gratitude to jakarta-based senior advisor for renewable energies dipl.-ing. horst kruse who accompanied this study substantially with his expertise. nevertheless, i emphasize that i take on responsibility for any possible error or vaguenesses in the published text. i would like to thank the administration of the national park ujung kulon for their friendly support, in particular, mrs. monica rahmaningsih, as well as the employees on peucang island who gave us a comprehensive understanding of the energy supply and consumption situation on the studied site. i would like to thank also the peucang island resort for offering transportation to the island and accommodation in the national park. finally, i am grateful that swiss german university could support this study through an internal research support scheme. references [1] energising development indonesia, (2016, may). interactive map of renewable energy power generation systems in indonesia [online]. available: http://www.remapindonesia.org/en/home [2] s. blocks. (2013, june). business assessment for diesel hybrid systems in indonesia. ekonid, [online]. available: https: //www.giz.de/fachexpertise/downloads/giz 2013-en-blocks1-pep-workshopindonesien-pv-hybridsysteme.pdf [3] t. strobel. diesel-fuel replacement: potential analysis for grid-connected photovoltaic systems in indonesia. giz, kementerian energi dan sumber daya mineral indonesia 2014. [online]. available: http://www.lcoreindonesia.or.id/index.php/publications [4] g. albright, j. edie, s. al-hallaj. a comparison of lead-acid to lithium-ion in stationary storage applications. allcell technologies llc 2015. [online]. available:https://www.scribd.com/docume nt/149522305/a-comparison-of-leadacid-to-lithium-ion-in-stationarystorage-applications [5] meteotest. (2016, may). irradiation data for every place on earth [online]. available: http://www.meteonorm.com [6] c. kost et al.. (2013). levelized cost of electricity. renewable energy technologies. fraunhofer. [online]. available: https://www.ise.fraunhofer.de/en/publicatio ns/veroeffentlichungen-pdf-dateienen/studien-und-konzeptpapiere/studylevelized-cost-of-electricity-renewableenergies.pdf [7] homer energy llc. (2016, may). microgrid software by homer energy. [online]. available: http://www.homerenergy.com/ [8] r. dufo-lopez et al., “comparison of different lead-acid battery lifetime prediction models for use in simulation of stand-alone photovoltaic systems,” in applied energy, volume 115, pp. 2422530, 2014. [9] powerthru. lead acid battery working– lifetime study. [online]. available: http://www.powerthru.com/documents/the%20truth%20ab out%20batteries%20%20powerthru%20white%20paper.p df. [10] j.m. bhatt. “effect of temperature on battery life and performance in electric vehicle,” international journal of scientific research, volume 2, issue 10, 2013. [11] sma solar technology ag. (2016, may). multicluster boxes for sunny island. [online]. available: http://www.sma.de/en/products/batteryinverters/multicluster-boxes-for-sunnyisland.html [12] hoppecke batterien gmbh & co. kg. (may, 2016). power.bloc opzv: valve regulated lead-acid battery. [online]. available: https://www.hoppecke.com/en/product/po werbloc-opzv/ [13] b. nykvist and m. nilsson. “rapidly falling costs of battery packs for electric vehicles,” nature climate change 5, pp. 329-332, 2015. [14] m. sterner and i. stadler, “energiespeicher–bedarf,” technologien, integration, berlin heidelberg: springer, pp. 613-616, 2014. [15] m.sterner, et al., der positive beitrag dezentraler batteriespeicher fuer eine m. günther / j. mechatron. electr. power veh. technol. 07 (2016) 113-122 122 stabile stromversorgung. forschungsstelle energienetze und energiespeicher (fenes), oth regensburg. short study mandated by bee e.v. and hannover fair 2015. regensburg/berlin/hannover, p. 8. [online]. available: http://www.beeev.de/fileadmin/publikationen/bee_hm_f enes_kurzstudie_der_positive_beitrag_v on_batteriespeichern_2015.pdf. [16] tesvolt gmbh. (2016, may). lithium storage. [online]. available: http://www.tesvolt.com/lithium-storagebattery-system-solar-wind-chp.html. [17] p. hummel,et al.. global utilities, auto & chemicals. will solar, batteries and electric cars re-shape the electrical system?. ed. by ubs2014. [online]. available: http://www.qualenergia.it/sites/default/files /articolo-doc/ues45625.pdf [18] t. waldmann et al., “temperature dependent ageing mechanisms in lithiumion batteries–a post-mortem study”, in journal of power sources, volume 262, pp. 129–135, 2014. i. introduction ii. research method iii. result a. consumption scenario b. design of the proposed electricity supply system iv. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2017.v8.76-84 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm muhammad ruswandi djalal a, *, herlambang setiadi b, andi imran c a department of mechanical engineering, ujung pandang state polytechnics jl. perintis kemerdekaan 7 km. 10, makassar, indonesia b school of information technology & electrical engineering the university of queensland level 4 / general purpose south building (building 78) st. lucia campus, brisbane, australia c department of electrical engineering, sepuluh nopember institute of technology jl. raya its, surabaya 60117, indonesia received 16 march 2017; received in revised form 7 november 2017; accepted 9 november 2017 published online 28 december 2017 abstract micro hydro has been chosen because it has advantages both economically, technically and as well as in terms of environmental friendliness. micro hydro is suitable to be used in areas that difficult to be reached by the grid. problems that often occur in the micro hydro system are not the constant rotation of the generator that caused by a change in load demand of the consumer. thus causing frequency fluctuations in the system that can lead to damage both in the plant and in terms of consumer electrical appliances. the appropriate control technology should be taken to support the optimum performance of micro hydro. therefore, this study will discuss a strategy of load frequency control by using energy storage. superconducting magnetic energy storage (smes) and capacitor energy storage (ces) are devices that can store energy in the form of a fast magnetic field in the superconducting coil. for the optimum performance, it is necessary to get the optimum tuning of smes and ces parameters. the artificial intelligence methods, cuckoo search algorithm (csa) are used to obtain the optimum parameters in the micro hydro system. the simulation results show that the application of the csa that use to tune the parameters of hybrid smes-ces-pid can reduce overshoot oscillation of frequency response in micro hydro power plant. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: micro hydro; superconducting magnetic-capacitive energy storage; cuckoo; overshoot. i. introduction development of micro hydro power plant is one of the government policies for improving the economic and social conditions of rural communities. in this case, the provision of electric power in the countryside is one of the solutions to enhance the social and economic conditions in the rural area. therefore, it is necessary to develop and utilize new and renewable energy sources by sticking to the principle of economically profitable, technically feasible, socially acceptable culture, and not causing environmental damage. hence, micro hydro is one of the power plants that can achieve such as requirements. one of the most important aspects of the power system is the frequency. the frequency has to be maintained according to the system requirement. the frequency generated by the micro hydro generator is greatly influenced by the rotational speed of the generator. moreover, the rotational speed of the generator is affected by the load changing. at night (above 23:00), ninety percent of homes turn off the lights, that makes the burden of the micro hydro is decreased. as a result, the frequency of the system will increase significantly. if the deviation of frequency is not well maintained, it will damage the electronic devices. therefore, it is necessary to control frequency and load demand automatically. this method can be called as load frequency control (lfc) [1]. the lfc of micro hydro can be done by arranging the wicket gate of micro hydro to control the water flow to the micro hydro. however, due to increasing load demand and uncertainty of it, lfc alone is not enough to handle the problems. hence, utilizing * corresponding author. tel: +62 852 5098 6419 e-mail: wandi@poliupg.ac.id https://dx.doi.org/10.14203/j.mev.2017.v8.76-84 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.76-84 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.76-84&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 77 energy storage as an additional device to increase the frequency stability of micro hydro power system is essential. the integration of energy storages has been increased significantly over the past few decade. there have been many application of energy storage on power sectors such as for voltage stability, small signal stability, and frequency stability. as reported by hung et al., the battery energy storage is used to stabilize the voltage stability on distribution system by considering high penetration of uncertainty photovoltaic plant [2]. impact of integration of battery energy storage system (bess) on electromechanical oscillations on the power system is reported by setiadi et al. [3]. in this research, the variation of bess proportional gain controller could change the dynamic characteristic of the power system. the influence of the large-scale battery energy storage system in the small signal stability of power system is reported by setiadi et al. [4]. in that research, battery energy storage has a significant influence on local and interarea oscillation. the application of redox flow batteries to enhance the frequency performance of power system is reported by shankar et al. [5]. this research reports that the rfb has a huge influence on stabilizing the frequency performance of the power system. the application of capacitor energy storage (ces) to stabilize the frequency performance of power systems is reported by kumar et al. [6]. moreover, the application of superconducting magnetic energy storage (smes) for enhancing small disturbance angle stability of multi-machine power system is reported by lastomo et al. [7]. however, very scant attention has been paid to integrate two different energy storages at the same time and assess the performance on frequency stability. hence, it is important to conduct a deeper study on how the frequency performance of power system, especially in micro hydro power plant when two different energy storage is integrating at the same time. other major issues are how to design the parameter of the energy storage and make it secure and reliable for providing active power to the system. hence, the utilizing metaheuristic algorithm as optimization method can be a solution for designing energy storage parameter. metaheuristic algorithm can be classified based on the inspiration. there are a socially based inspiration, a physically based inspiration, and a biological based inspiration. in recent years, the application of metaheuristic based on biological inspiration such as particle swarm optimization and ant colony optimization are increasing significantly [8, 9]. however, those algorithms still have several drawbacks including long computation process and stuck at local optimum [10]. hence, the deployment of a new and optimum algorithm such as cuckoo search algorithm (csa) is crucial [11]. hence, the novelty of this paper are: investigating the frequency performance of micro hydro power plant, enhancement of frequency stability of micro hydro power plant using hybrid superconducting magnetic energy storage (smes) and capacitor energy storage (ces), and utilizing csa as optimization method for designing smes and ces. ii. fundamental theory a. micro hydro power plant the working principle of micro hydro power plant is utilizing the waterfall flow of a river. micro hydro turbine can generate the mechanical energy using water flow power. this mechanical energy will spin the generator to produce electricity. the mathematical representation of electric power that can be generated from micro hydro can be described as given in equation (1) [12]. 3 [ ] [ / ]. [ ]. [ / ] th p w q m s h m k n kg (1) where pth and q are active power generated from micro hydro and the amount of water flow to the turbine. h and k corresponded to the high of the water flow and gravitational constant. moreover, completed representation of active power from the systems considering turbine (turbine) and generator (gen) efficiency can be described using equation (2) [12]. 3 [ ] [ / ]. [ ]. [ / ]. . real turbin gen p w q m s h m k n kg   (2) for frequency stability study, the micro hydro power plant modelled as linear system (figure 1) 1 . 1 b t s  + _ + _ + _ _ . 1 kg tg s  . 1 s k ts s  + _ 3 . 1 k t s  water discharge 0.01 rate limiter servo motor as governor error detection gain 1 induction generator gain turbine load excharge k2 k1 scope figure 1. block diagram of micro hydro m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 78 consists of induction generator, turbine, and servomotor as the governor [12]. b. superconducting magnetic energy storage superconducting magnetic energy storage (smes) store energy in a magnetic field created by the dc current in superconducting coils cooled by cryogenic systems. smes comprises of a superconducting coil, cryogenic cooling system, and a power conditioning system (pcs). pcs is referred as a power electronic interface between smes coil and the grid. in principle, superconductors have losses almost zero at cold temperature. the cryogenic of smes consist of liquid helium, which can maintain the temperature at 4 k. the pcs is used to transfer energy from the smes coil towards the system. a dc link capacitor pcs uses to connect the source voltage of the smes coil towards the system. the working principle of smes is divided into three, charging mode, standby mode, and discharging mode [13]. setting performance of smes is carried out by adjusting the duty cycle (d) of the converter which in this case using the gate turn off (gto) thyristors [14]. figure 2 shows a schematic diagram of smes while the mathematical representation of smes can be described as given in equations (3) to (7). * sm dc v d v (3) (1 ) * sm dc v d v   (4) 0 0 1 t sm dc sm t sm i v d i l   (5) sm sm sm p v i (6) 21 2 sm sm sm w l i (7) equation (3) is smes mode in charging mode, where vsm is voltage in smes coils, vdc is voltage in dc link capacitor and d is duty cycle. ism0 is the initial current of the inductor. psm is power stored or transmitted by smes. wsm is the energy stored in the smes coil. then, equation (4) is a mathematical representation of smes in discharging mode, while equation (5) is a representation of current smes. furthermore, equation (6) described energy from smes, while equation (7) described the energy in smes’s coil. figure 3 shows smes configuration. the parameters that are owned by the smes is starting from the input side in the form of . after that, the signal will enter the washout block where there is a washout time constant from smes. it is then amplified by the smes constantly reinforcing on the loop gain block. in this block, there is also a tdc time delay constant from the smes control device. the next step is to restrict the signal to the desired saturation conditions on the rate limiter. next signal is forwarded to the transfer block function inductance smes where there is a parameter of lsm. the lsm is then summed with ido to produce the output. the resulting output, psm, is used as input (compensation) on the generator while waiting for the governor work. smes is placed at the bus terminal of the generator to control the balance of power in the generator effectively. the block diagram of smespid can be made using several smes equations from references, as shown in figure 4 [14, 15]. dc link capacitor transformer voltage source converter using gto dc-dc chopper ism bypass switch smes coil 3 phase ac (from terminal bus generator) figure 3. smes configuration w ( + + ) 1+st i p d ks k sk s δω 1 + c dc k st 1 sm sl π+ id0 psm vsm ism figure 4. block diagram of smes-pid figure 2. schematic diagram of smes m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 79 c. capacitor energy storage capacitor energy storage (ces) stores energy in the form of an electric field in the capacitor. a ces consists of a storage capacitor and pcs. storage capacitor consists of several discrete capacitors connected in parallel with capacitance (c). leaking losses and dielectric capacitor bank at ces modeled by a resistance (r) connected in parallel to the capacitor. storage capacitor connected to the grid through the pcs 12-pulse. pcs consists of ac to dc rectifier and dc to ac inverter. figure 5 shows the schematic diagram of ces [16, 17]. thyristor bypass serves to provide a path for current flow (id) when converter failure occurs. dc breaker allows current (id) energy diverted to discharge energy of resistor rd if the converter fails. by ignoring losses, bridge voltage (ed) is as given in equation (8) and (9) [16, 17]. 02 cos 2d d d de e i r  (8) 2 2 1/ 2 max min 0 [ ] 2 d d d e e e   (9) in the case that perturbation occurs in the system, the capacitor voltage is too low and other disorders occur before the voltage back to normal values, the energy will be more withdrawn from the capacitor which can cause intermittent control. the limit for the capacitor voltage is 30% lower from the rating ed0 value to solve this problem. hence, the mathematical representation can be described using equation (10) [16, 17]. min 0 30 d d e e (10) the operating point of the capacitor is such that the total energy absorbed which is equal to the amount of energy depleted. initially, the capacitor is charged to its set ed0 value. the ces voltage must find the initial condition as soon as possible to maintain the performance of the system. therefore, a negative feedback signal of capacitor voltage deviation is essential to achieve a fast response of ces. the block diagram of ces is depicted in figure 6 [17, 18]. where the capacitor voltage deviation (δed) can be described as given in equation (11) [17, 18]. 1 1d d e i sc r           (11) moreover, the ces power output injected into the system can be presented in equation (12) [17, 18]. 0 ( ) ces d d d p e e i    (12) iii. design hybrid smes and ces using cuckoo search algorithm this section provides a dynamic model of the overall system and cuckoo search algorithm. at the end of this section, the objective function of the simulation is presented and the objective function will be achieved by using csa. a. overall simulation based on the equations (1) to (12), the overall dynamic model of the entire system can be expressed in figures 7 to figure 9. figure 7 illustrates the test system (micro hydro for frequency stability) with smes and ces installed in the system. figure 8 shows the dynamic model of ces in simulink, while figure 9 depicts a dynamic representation of smes in simulink. in this research, all of the systems are expressed in the linear model. the parameter that will be optimized by csa is the smes and ces parameter. dc breaker dump resistor r storage capasitor + c id id 6-pulse bridge convertor 6-pulse bridge convertor y pcs by pass scr reversing switch arrangement s1 s2 s3 s 4 3p 3p 3p figure 5. schematic diagram of capacitor energy storage   - cesk dcst1 1 vdk r sc 1 1  di di     dd ee 0 de 0de f cesp figure 6. block diagram ces m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 80 b. cuckoo search algorithm the cuckoo search algorithm is one of the metaheuristic algorithm developed by xin she yang et al. [19], inspired by the behavior of cuckoo bird in breeding. from all species of cuckoo, it is known that 59 of them are parasitic. they utilize breeding nests of other birds of different species to incubate their eggs. in fact, not infrequently cuckoo eggs were put on another cuckoo's nest [20, 21]. several types of cuckoo throw eggs from the original parent at the nest to increase the likelihood of their eggs hatch. it may cause a conflict between the host and cuckoo birds when the cuckoo lays its eggs, so the bird hosts throw the cuckoo’s egg or leave their nests and then discard the new nest. other parasitic behavior is when the cuckoo hatches, cuckoo eggs usually hatch earlier than the host bird eggs, the unhatched eggs were discharged from the cuckoo's nest for children to get more food [20, 21]. figure 10 shows the cuckoo algorithm process in finding the controller parameters. starting from the initialization parameters, the optimization process, and finally the optimum parameter optimization results. the final rule can be simplified with the approach pa fraction of n nest replaced with a new nest (with new solutions at random). for maximizing problems, quality or fitness of a solution can be compared to the figure 7. simulink model of entire system figure 8. simulink model of smes figure 9. simulink model of ces figure 10. cuckoo search algorithm process m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 81 value of the objective function. other forms of fitness can be defined in the same manner as the fitness function in the genetic algorithm. for simplicity, it can use a simple representation that any eggs in the nest represent a solution, and the cuckoo egg represents a new solution, the aim is to use the potential of new and better solutions (cuckoos) to replace a solution that is not good on the nest. then the eggs had to be evolved, the more eggs will replace other eggs as measured by fitness, like in ga [20, 21]. in a host nest, there can be two eggs, in other words, the nest can hold more than one solution only to simplify the problem, and a nest will only store one solution (eggs). based on the three rules, the basic steps cuckoo search (cs) can be summarized as pseudo code below [20, 21]. begin objective function f (x), x = (x 1, ..., x) t initialize the population of the target bird nest n xi (i = 1,2, ..., n) while (t <generasitotal) or (other criteria to stop) evaluation of the quality values of each cuckoo cuckoo choose from randomly and do a random walk if (fi> fj) replace cuckoo cuckoo j with i end if re reset nests with the worst conditions (pa) save nests that survived sort and find the best solutions end while process results and visualization end when the generation of new solutions x (t + 1) for a i cuckoo, levy flight is shown as follows: the mathematical representation to generate a new solution considering levy flight can be described using equation (13) [20, 21].  )1( ( ) t ti ix x levy      (13) in equation (13), α> 0 is a measure of the stages that should be related to the scale of the problem of interest. in the most cases, the value of α is 1. furthermore, the mathematical representation of levy flight (random walk) can be defined using equation (14) [20, 21].   ~ , 1 3levy u t     (14) c. objective function the objective function that used is integral time absolute error (itae), where the csa will be optimized all parameters by minimizing the frequency error of the micro hydro as described in equation (15). 0 ( ) t itae t t dt  (15) where δω is the frequency deviation of the system while t is the period of the simulation. figure 11 shows the flowchart of the csa for optimizing smes and ces parameter. the parameter of smes that will be optimized by csa is ksmes, tdc, tw, kp, ki, and kd, while the parameter of ces is kces, tdc, kp, ki and kd. table 1 shows the parameter of cuckoo search algorithm (the parameter if cuckoo search algorithm is a dimensionless parameter) on this paper while table 2 shows the lower and upper limit of the smes and ces parameter. the algorithm starts by initializing the micro hydro, smes, ces, and csa parameters followed by initializing the population of the host with the particular constraint. the next step is a random search of cuckoo by using levy flight function. evaluation of the objective function is done by using itae of the frequency micro hydro. the process is continued by finding the best nest by using random process. the cuckoo will remove the pa from the worst nest and put that pa to the new nest. if the criteria are not satisfied, then the algorithm will be back to the initializing process. the algorithm will loop the process until the criteria is satisfied, in this paper the criteria is the max generation. table 1. parameters of cuckoo search algorithm. parameter value number of nests 25 discovery rate of alien eggs/solutions 0.25 tolerance 1.0e-5 max generation 50 number of variable (nd) 11 table 2. constraints of csa parameters lower upper ces kces 80 90 tdc 0.03 0.06 kp 10 15 ki 0.1 0.5 kd 0 1 smes tdc 0.01 0.03 tw 15 30 ksmes 70 90 kp 35 40 ki 0 1 kd 0 0.1 m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 82 iv. result and discussion in this paper, three sections are reported in an attempt to investigate the enhancement of frequency stability using the proposed method. a load frequency control model of the micro hydro power system is used in this study. the case study was carried on matlab/simulink environmental. table 3 shows the dynamic data of micro hydro [22], smes, and ces used in this paper while table 4 illustrates the optimized parameter of smes and ces using csa. a. governor time domain response this section is focusing on analyzing the governor response of micro hydro under different scenarios due to the small load perturbation. figure 12 illustrates the governor response of micro hydro under different scenarios. it can be seen that by adding additional devices such as smes, and ces, the overshoot of the governor response was decreased. table 5 shows the detailed featured of overshoot of the micro hydro governor under different scenarios. it was observed that the best response was performed by system with smes-pid-ces-pid indicated by smallest overshoot compared to the other scenarios. start input parameter of csa : number of nest (n) discovery rate (pa) tolerance (tol) lower bounds & upper bound smes, ces and pid (lb,ub) maximum generation (maxgen) number of variable smes-ces-pid (nd) micro-hydro parameter cuckoo random search with levy flights end no evaluation fitness function of cuckoo the owner put back the cuckoo's nest best quality at random removing pa from worst nest and make a new one with the levy flights initialization population of host nest results process, visualization and output results of tuning parameters smes, ces & pid check criteria manufacture, describe best solution / the best nest a b a b yes figure 11. flowchart of the csa for optimizing ces and smes table 4. optimum parameter of smes and ces parameters csa result ces kces 88.1472 tdc 0.0572 kp 10.6349 ki 0.4654 kd 0.6324 smes tdc 0.0120 tw 19.1775 ksmes 80.9376 kp 39.7875 ki 0.9649 kd 0.0158 table 3. dynamic data of the test system [22] parameter value tb 1 kg 1 tg 13,333 k1 5 k2 8,52 k3 0.004 t 0,02 ts 0,1 ks 2,5 sg 40 pf 0,8 vg 400/231 ω 1500 fg 50 m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 83 b. frequency dynamic response the time domain response of the frequency micro hydro could be performed by giving step input of small load disturbance in the system as shown in figure 13. it was found that the frequency response of the system was increased when smes and ces were installed on the system. this condition can be happened due to additional active power from ces and smes. it was also found that by adding pid controller on smes and ces could also increase the frequency of the system. it could be happened due to additional control signals from pid that make smes and ces able to give more detailed active power to the system when small perturbation occurs. table 6 illustrates the detailed features of overshoot of the micro hydro frequency response under different scenarios. it was observed that system table 6. overshoot of governor cases overshoot uncontrolled -0.00031811 pid -0.00021392 ces -0.00012623 ces-pid -0.00001604 smes -0.00019384 smes-pid -0.00004173 smes-ces -0.00010412 smes-ces-pid -0.00001581 smes-pid-ces -0.00003552 smes-pid-ces-pid -0.00000983 table 5. overshoot of governor cases overshoot uncontrolled -0.00000453 pid -0.00000312 ces -0.00000181 ces-pid -0.00000023 smes -0.00000281 smes-pid -0.00000061 smes-ces -0.00000154 smes-ces-pid -0.00000013 smes-pid-ces -0.00000052 smes-pid-ces-pid -0.00000009 figure 12. governor response under different scenarios figure 13. frequency response under different scenarios 0 5 10 15 20 -5 -4 -3 -2 -1 0 1 x 10 -6 time (s) g o v e rn o r r e s p o n s e uncontrol smes-ces smes-ces-pid ces-pid ces smes smes-pid smes-pid-ces pid smes-pid-ces-pid 0 5 10 15 20 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 x 10 -4 time (s) f re q u e n c y d e v ia ti o n ( p u ) uncontrol smes-ces smes-ces-pid ces-pid ces smes smes-pid smes-pid-ces pid smes-pid-ces-pid m.r. djalal et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 76–84 84 with hybrid smes-pid and ces-pid experienced lower overshoot compared to the other scenarios. moreover, smes and ces could store and release active power from the system depending on the condition of the load. if the load was increased, then smes and ces will release (discharging) active power to the system, so the burden of the system is decreased (the system will experience lower overshoot). in contrary, if the load was decreased, the smes and ces will store (charging) surplus active power from the system. v. conclusion this paper proposed a method to enhance the frequency performance of micro hydro power system using hybrid smes and ces based on csa. from the investigated case study, it is found that by adding smes and ces can enhance the frequency performance of the micro hydro power systems. it is also observed that the best performance is shown by the system with proposed method (hybrid smes and ces based on csa) indicated by the smallest overshoot and fastest settling from all of the scenarios. further research needs to be conducted to analyze the impact of integrating smes – ces hybrid in larger system, such as load frequency control of two or more power systems. high penetration of renewable energy sources in frequency stability domain can be considered to analyze the significant impact of integrating smes – ces hybrid. moreover, employing another metaheuristic algorithm such as grey wolf algorithm, whale algorithm, and social spider algorithm can be considered to get better parameter of smes and ces. acknowledgement authors would like to thank state polytechnic of ujung pandang for supporting this research. references [1] m. abdillah et al., "optimal selection of lqr parameter using ais for lfc in a multi-area power system," journal of mechatronics, electrical power, and vehicular technology, vol. 7, pp. 93-104, 2016. [2] d. q. hung et al., "integration of pv and bes units in commercial distribution systems considering energy loss and voltage stability," applied energy, vol. 113, pp. 1162-1170, 2014. [3] h. setiadi et al., "impact of battery energy storage systems on electromechanical oscillations in power systems," in 2017 ieee power and energy general meeting, chicago, usa, 2017. [4] h. setiadi et al., "influence of bes system on local and interarea oscillation of power system with high penetration of pv plants," in applied system innovation (icasi), 2017 international conference on, 2017, pp. 1-4. [5] r. shankar et al., "impact of energy storage system on load frequency control for diverse sources of interconnected power system in deregulated power environment," international journal of electrical power & energy systems, vol. 79, pp. 11-26, 7// 2016. [6] n. v. kumar and m. m. t. ansari, "a new design of dual mode type-ii fuzzy logic load frequency controller for interconnected power systems with parallel ac–dc tie-lines and capacitor energy storage unit," international journal of electrical power & energy systems, vol. 82, pp. 579-598, 2016. [7] d. lastomo et al., "optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system," journal of mechatronics, electrical power, and vehicular technology, vol. 8, pp. 11-21, 2017. [8] d. lastomo et al., "enabling pid and sssc for load frequency control using particle swarm optimization," in 2017 3rd international conference on science in information technology (icsitech), 2017. [9] m. taufik et al., "small-disturbance angle stability enhancement using intelligent redox flow batteries," in 2017 4th international conference on electrical engineering, computer science and informatics (eecsi 2017), yogyakarta, indonesia, 2017. [10] d. lastomo et al., "small signal stability enhancement of hybrid power system using rfb tune with craziness particle swarm optimization," in 2017 3rd international conference on science in information technology (icsitech), bandung, indonesia, 2017. [11] m. r. djalal et al., "desain optimal kontroler pid motor dc menggunakan cuckoo search algorithm," prosiding sentia, 2015. [12] s. doolla et al., "load frequency control of an isolated small hydro power plant using multi-pipe scheme," electric power components and systems, vol. 39, pp. 46-63, 2011. [13] h. setiadi and k. o. jones, "power system design using firefly algorithm for dynamic stability enhancement," indonesian journal of electrical engineering and computer science, vol. 1, pp. 446-455, 2016. [14] w. yao et al., "adaptive power oscillation damping controller of superconducting magnetic energy storage device for interarea oscillations in power system," international journal of electrical power & energy systems, vol. 78, pp. 555-562, 2016. [15] h. shayeghi and h. shayanfar, "application of pso for fuzzy load frequency design with considering superconducting magnetic energy storage," international journal on “technical and physical problems of engineering”(ijtpe), vol. 2, pp. 24-33, 2010. [16] m. r. djalal et al., "frequency control pltmh dengan capacitive energy storage menggunakan cuckoo search algorithm," in sentia 2015, 2015. [17] a. chatterjee et al., "transient performance improvement of grid connected hydro system using distributed generation and capacitive energy storage unit," international journal of electrical power & energy systems, vol. 43, pp. 210-221, 2012. [18] d. lastomo et al., "the effects of energy storage on small signal stability of a power system," in 2017 international seminar on technology and its application (isitia), surabaya, indonesia, 2017. [19] s. m. abd elazim and e. s. ali, "optimal power system stabilizers design via cuckoo search algorithm," international journal of electrical power & energy systems, vol. 75, pp. 99-107, 2016/02/01/ 2016. [20] a. h. gandomi et al., "cuckoo search algorithm: a metaheuristic approach to solve structural optimization problems," engineering with computers, vol. 29, pp. 17-35, 2013. [21] x.-s. yang, cuckoo search and firefly algorithm: theory and applications vol. 516: springer, 2013. [22] i. t. yuniahastuti et al., "load frequency control (lfc) of micro-hydro power plant with capacitive energy storage (ces) using bat algorithm (ba)," in technology of information and communication (isemantic), international seminar on application for, 2016, pp. 147-151. http://dx.doi.org/10.14203/j.mev.2016.v7.93-104 http://dx.doi.org/10.14203/j.mev.2016.v7.93-104 http://dx.doi.org/10.14203/j.mev.2016.v7.93-104 http://dx.doi.org/10.14203/j.mev.2016.v7.93-104 https://doi.org/10.1016/j.apenergy.2013.08.069 https://doi.org/10.1016/j.apenergy.2013.08.069 https://doi.org/10.1016/j.apenergy.2013.08.069 https://doi.org/10.1016/j.apenergy.2013.08.069 http://pes-gm.org/2017/images/pdfs/ieee_pes_gm2017_program.pdf http://pes-gm.org/2017/images/pdfs/ieee_pes_gm2017_program.pdf http://pes-gm.org/2017/images/pdfs/ieee_pes_gm2017_program.pdf http://pes-gm.org/2017/images/pdfs/ieee_pes_gm2017_program.pdf https://doi.org/10.1109/icasi.2017.7988234 https://doi.org/10.1109/icasi.2017.7988234 https://doi.org/10.1109/icasi.2017.7988234 https://doi.org/10.1109/icasi.2017.7988234 https://doi.org/10.1016/j.ijepes.2015.12.029 https://doi.org/10.1016/j.ijepes.2015.12.029 https://doi.org/10.1016/j.ijepes.2015.12.029 https://doi.org/10.1016/j.ijepes.2015.12.029 https://doi.org/10.1016/j.ijepes.2015.12.029 https://doi.org/10.1016/j.ijepes.2016.03.063 https://doi.org/10.1016/j.ijepes.2016.03.063 https://doi.org/10.1016/j.ijepes.2016.03.063 https://doi.org/10.1016/j.ijepes.2016.03.063 https://doi.org/10.1016/j.ijepes.2016.03.063 https://doi.org/10.1016/j.ijepes.2016.03.063 http://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://icsitech.org/2017/program http://icsitech.org/2017/program http://icsitech.org/2017/program http://icsitech.org/2017/program https://doi.org/10.1109/eecsi.2017.8239143 https://doi.org/10.1109/eecsi.2017.8239143 https://doi.org/10.1109/eecsi.2017.8239143 https://doi.org/10.1109/eecsi.2017.8239143 https://doi.org/10.1109/eecsi.2017.8239143 http://icsitech.org/2017/program http://icsitech.org/2017/program http://icsitech.org/2017/program http://icsitech.org/2017/program http://icsitech.org/2017/program http://sentia.polinema.ac.id/index.php/sentia2015/article/view/185 http://sentia.polinema.ac.id/index.php/sentia2015/article/view/185 http://sentia.polinema.ac.id/index.php/sentia2015/article/view/185 https://doi.org/10.1080/15325008.2010.513362 https://doi.org/10.1080/15325008.2010.513362 https://doi.org/10.1080/15325008.2010.513362 https://doi.org/10.11591/ijeecs.v1.i3.pp446-455 https://doi.org/10.11591/ijeecs.v1.i3.pp446-455 https://doi.org/10.11591/ijeecs.v1.i3.pp446-455 https://doi.org/10.11591/ijeecs.v1.i3.pp446-455 https://doi.org/10.1016/j.ijepes.2015.11.055 https://doi.org/10.1016/j.ijepes.2015.11.055 https://doi.org/10.1016/j.ijepes.2015.11.055 https://doi.org/10.1016/j.ijepes.2015.11.055 https://doi.org/10.1016/j.ijepes.2015.11.055 http://www.iotpe.com/ijtpe/ijtpe-2010/ijtpe-issue2-vol2-no1-mar2010/5-ijtpe-issue2-vol2-no1-mar2010-pp24-33.pdf http://www.iotpe.com/ijtpe/ijtpe-2010/ijtpe-issue2-vol2-no1-mar2010/5-ijtpe-issue2-vol2-no1-mar2010-pp24-33.pdf http://www.iotpe.com/ijtpe/ijtpe-2010/ijtpe-issue2-vol2-no1-mar2010/5-ijtpe-issue2-vol2-no1-mar2010-pp24-33.pdf http://www.iotpe.com/ijtpe/ijtpe-2010/ijtpe-issue2-vol2-no1-mar2010/5-ijtpe-issue2-vol2-no1-mar2010-pp24-33.pdf http://www.iotpe.com/ijtpe/ijtpe-2010/ijtpe-issue2-vol2-no1-mar2010/5-ijtpe-issue2-vol2-no1-mar2010-pp24-33.pdf http://sentia.polinema.ac.id/index.php/sentia2015/article/view/176 http://sentia.polinema.ac.id/index.php/sentia2015/article/view/176 http://sentia.polinema.ac.id/index.php/sentia2015/article/view/176 https://doi.org/10.1016/j.ijepes.2012.04.031 https://doi.org/10.1016/j.ijepes.2012.04.031 https://doi.org/10.1016/j.ijepes.2012.04.031 https://doi.org/10.1016/j.ijepes.2012.04.031 https://doi.org/10.1016/j.ijepes.2012.04.031 https://doi.org/10.1109/isitia.2017.8124054 https://doi.org/10.1109/isitia.2017.8124054 https://doi.org/10.1109/isitia.2017.8124054 https://doi.org/10.1109/isitia.2017.8124054 https://doi.org/10.1016/j.ijepes.2015.08.018 https://doi.org/10.1016/j.ijepes.2015.08.018 https://doi.org/10.1016/j.ijepes.2015.08.018 https://doi.org/10.1016/j.ijepes.2015.08.018 http://dx.doi.org/10.1007/s00366-012-0308-4 http://dx.doi.org/10.1007/s00366-012-0308-4 http://dx.doi.org/10.1007/s00366-012-0308-4 http://dx.doi.org/10.1007/s00366-012-0308-4 https://doi.org/10.1007/978-3-319-02141-6 https://doi.org/10.1007/978-3-319-02141-6 https://doi.org/10.1109/isemantic.2016.7873828 https://doi.org/10.1109/isemantic.2016.7873828 https://doi.org/10.1109/isemantic.2016.7873828 https://doi.org/10.1109/isemantic.2016.7873828 https://doi.org/10.1109/isemantic.2016.7873828 mev j. mechatron. electr. power veh. technol. 06 (2015) 105-112 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.105-112 design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model slamet kasbi a, c, estiko rijanto b, *, rasli bin abd ghani a ªmalaysia-japan international inst. of tech. (mjiit), universiti teknologi malaysia (utm) kuala lumpur jalan semarak, 54100 kuala lumpur, malaysia bresearch center for electrical power and mechatronics, indonesian institute of sciences (lipi) kampus lipi, jalan sangkuriang, gd.20, bandung 40135, indonesia cministry of energy and mineral resources (kesdm), research and development agency (p3tkebtke) jl. ciledug raya kav.109 cipulir kebayoran lama, jakarta 12230, indonesia received 5 august 2015; received in revised form 17 september 2015; accepted 17 september 2015 published online 30 december 2015 abstract boost dc-dc converters are used in many renewable energy sources including photovoltaic and fuel cell. they are also used in uninterrupted power supply, inverters, electric vehicles and robots. in this paper a boost converter was built and its controller was developed using proportional integral (pi) action for current loop and low pass filter (lpf) for voltage loop. the controller was derived analytically based on small signal model. experiment results show that the boost controller functions well in regulating the output voltage under a variation of load. during the start up without any load it can elevate input voltage from 119.6 v to output voltage of 241.6 v. the developed controller can regulate the output voltage smoothly under load variation from no load to sudden load of 352 w. when a large sudden load change happens from 0 w to 1,042 w the output voltage experiences small drop before it is recovered to 241.6 v. it can be concluded that the developed control system satisfies the design specification. keywords: controller; boost dc-dc converter; pi; lpf; small signal. i. introduction a boost dc-dc converter functions to elevate a low level dc voltage to a higher level dc voltage. they are used in many renewable energy sources including photovoltaic and fuel cell. they are also used in uninterrupted power supply (ups), inverters, electric vehicles, and robots. many types of controllers for boost dc-dc converters have been proposed by other researchers. one type of the controller is a controller that was designed on the basis of current mode control (cmc) and linear quadratic regulator (lqr) [1]. it incorporates feedback gains of the lqr. the controller was designed so that the inductor current could follow any given reference current which could be the output of a maximum power point tracking (mppt) algorithm. the method has been proved through matlab/simulink simulation [1]. in other study, a repetitive controller was added to a proportional integral controller in current loop to lessen crossover distortion of input current as proved through computer simulation [2]. in a more recent study, an extended kalman filter was proposed for inductor current estimation and output voltage filtering where a predictive average current control was used to regulate the current [3]. experimental results showed that the transient response was improved compared to conventional voltage control system. rao et al. (2013) used a proportional integral derivative (pid) controller without any current loop to directly control output voltage where its parameter values were determined by the use of genetic algorithm (ga) [4]. they concluded that ga provides better performance than bacterial foraging algorithm (bfoa). other studies proposed different approaches. a model predictive control (mpc) approach was used * corresponding author.tel: +62-22-2503055 e-mail: estiko.rijanto@lipi.go.id http://dx.doi.org/10.14203/j.mev.2015.v6.105-112 s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 106 which could explicitly account for physical constraints on duty cycle and inductor current [5]. an approximate 2-degrees-of-freedom digital controller was proposed for suppressing the change of step response characteristics and variation of output voltage in the load sudden changes [6]. the load and output voltage changes are considered as parameter changes which are transformed to equivalent disturbances. the controller is constructed using model matching, inverse system and filter, and it has been examined and well-proved through experiment [6]. control methods based on sliding mode have also been reported by many other researchers [7,8]. they demonstrated the effectiveness of their methods through computer simulations. zakiyullah et al. (2012) used pi controller for a dc-dc bidirectional converter where its parameter values were determined through numerical simulation [9]. in other study by seno aji et al. (2013), fuzzy controller was used for a boost dc-dc converter coupled with mppt in a photovoltaic system for a solar car where its effectiveness was verified through computer simulation [10]. in this study, boost dc-dc converter was built and its controller was also designed. an analytical approach is used based on average small signal model. the converter is to elevate a dc voltage source from 120 v to 240 v with the power capacity of 4.5 kw. to realize such a converter, a power electronic circuit was built using appropriately selected inductor, capacitor, mosfet and other components. then, a controller was designed to maintain the converter output voltage under load variations. to design the controller, firstly small signal dynamical model was derived. the controller was composed of two control loops namely current control loop and voltage controller loop. the current controller was designed using proportional and integral (pi) actions while the voltage controller was designed using low pass filter (lpf) transfer function. finally, the effectiveness of the developed control system was verified through an experiment. section 2 of this paper presents conceptual design, specification and dynamical modeling of the boost dc-dc converter. section 3 is devoted to controller design of the boost dc-dc converter using simplified version of the derived dynamical model. section 4 describes experiment results and discussion. section 5 summarizes the conclusions. ii. specification and modeling a. specification figure 1 shows block diagram of the boost dc-dc converter control system developed in this study. this control system consists of a boost dc-dc converter and its controller. the boost converter was constructed from inductor, diode, capacitor, and switch which was equipped with its driver circuit. other components shown in the figure are input filter, soft start circuit, and snubber. a controller was designed to control the output voltage of the converter. it receives feedback signals including output voltage, input voltage, and input current. it computes error value between the voltage reference and ouput voltage signal, and then calculates modulated control pulse signal which is sent to the driver of the switch. table 1 shows the design specification of the boost dc-dc converter. this specification came from a real need to accommodate an inverter which converts 240 v dc to 220 v ac using 120 v dc from a string of batteris. from this table it can be calculated that the inductor average current is 37.5 a, and the nominal load is 12.8 ohm. b. modeling of the boost dc-dc converter the boost converter operates in two switching modes namely closed mode (switch on) and open mode (switch off). during the closed mode, the dynamics of the converter can be expressed in the following equations; cin d3 d2 d5 r3 r1 co d1 d4 r2rin vi vosw1 sw2 llf load vos vis iis controller vref figure 1. the developed boost converter control system table 1. specification of the boost converter parameter value unit maximum power, pmax 4,500 w maximum input voltage, vimax 130 v nominal input voltage, vinom 120 v minimum input voltage, vimin 100 v reference ouput voltage, vref 240 v switching frequency, fs 62,000 hz s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 107 𝐿 𝑑𝑖𝐿 (𝑡) 𝑑𝑡 + 𝑟𝑖𝐿 (𝑡) = 𝑉𝑖 (1) 𝐶 𝑑𝑉𝑜(𝑡) 𝑑𝑡 + 𝑉𝑜(𝑡) 𝑅 = 0 (2) where the parameters 𝐿 , 𝐶 , 𝑟 , and 𝑅 denote inductor, output capacitor, internal resistance of the inductor, and load resistor, respectively. the variable s𝑖𝐿, 𝑉𝑜, and 𝑉𝑖 represent inductor current, output voltage, and input voltage. the initial values of inductor current and output voltage are assumed to be 𝑖𝐿 (0) = 𝑖10 and 𝑉𝑜(0) = 𝑉10. during open mode, the dynamics of the converter is given as follows; 𝐿 𝑑𝑖𝐿 (𝑡) 𝑑𝑡 + 𝑟𝑖𝐿 (𝑡) + 𝑉𝑜 (𝑡) = 𝑉𝑖 (3) 𝐶 𝑑𝑉𝑜(𝑡) 𝑑𝑡 + 𝑉𝑜(𝑡) 𝑅 = 𝑖𝐿 (𝑡) (4) the initial values of inductor current and output voltage are assumed to be 𝑖𝐿 (0) = 𝑖20 and 𝑉𝑜(0) = 𝑉20. the relationship among the time period of the switch being closed 𝑡𝑜𝑛 , opened 𝑡𝑜𝑓𝑓 and switching period 𝑇𝑠 is given by the following equation. 𝑡𝑜𝑛 + 𝑡𝑜𝑓𝑓 = 𝑇𝑠 = 1 𝑓𝑠 (5) in the steady state condition the following relationships hold; 𝑖20 = 𝑖𝐿 (𝑡𝑜𝑛) 𝑖10 = 𝑖𝐿 (𝑡𝑜𝑓𝑓 ) } (6) 𝑉20 = 𝑉𝑜 (𝑡𝑜𝑛) 𝑉10 = 𝑉𝑜 (𝑡𝑜𝑓𝑓 ) } (7) furthermore, under ideal condition without energy losses, the total energy transferred from the energy source to the output capacitor through the inductor during switch off is the same as that which is saved into the inductor during switch on. this yields the following equation; 𝑉𝑜 𝑉𝑖 = 𝑇𝑠 𝑡𝑜𝑓𝑓 = 𝑇𝑠 𝑇𝑠−𝑡𝑜𝑛 = 1 1−𝐷 (8) where 𝐷 denotes duty ratio. given input voltage and output voltage values in the specification listed in table 1, the nominal duty ratio of 0.5 is obtained. after some calculation from the dynamics equations in (1)-(4) the following average small signal model is obtained: [ �̇�1 �̇�2 ] = [ 0 −(1−𝐷) 𝐿 (1−𝐷) 𝐶 −1 𝑅𝐶 ] [ 𝑥1 𝑥2 ] + [ 𝑉𝑜 𝐿 −𝐼𝐿 𝐶 ] �̂� + [ 1 𝐿 0 ] �̂�𝑖 (9) where 𝑥1 is small deviation of current value around its nominal value 𝑥2 is small deviation of output voltage value around its nominal value �̂� and 𝑣𝑖 represent deviation of duty ratio around nominal value and the deviation of input voltage value around its nominal value, respectively. the internal resistance of the inductor is assumed to be much smaller than the inductance so that the following relationship can be derived from equation (1). 𝐿 ∆𝑖𝐿 𝑡𝑜𝑛 = 𝑉𝑖 ⇒ 𝐿 = 𝑉𝑖 ∆𝑖𝐿 𝐷 𝑓𝑠 (10) where ∆𝑖𝐿 represents inductor current ripple. by specifying acceptable current ripple value, from equation (10) the value of inductance can be determined. in this paper the values of inductance and output capacitor are selected to be 129 µh and 2.15 mf. iii. controller design from the average small signal model in equation (9) the following transfer functions can be derived: 𝑃1(𝑠) = 𝑥1(𝑠) �̂�(𝑠) = (𝐶𝑉𝑜)𝑠+2(1−𝐷)𝐼𝐿 (𝐿𝐶)𝑠2+ 𝐿 𝑅 𝑠+(1−𝐷)2 (11) 𝑃2(𝑠) = 𝑥2(𝑠) �̂�(𝑠) = (1−𝐷)𝑉𝑜−(𝐿𝐼𝐿)𝑠 (𝐿𝐶)𝑠2+ 𝐿 𝑅 𝑠+(1−𝐷)2 (12) 𝑃1(𝑠) and 𝑃2(𝑠) express transfer functions from duty ratio to inductor current and from duty ratio to output voltage of the boost converter. obviously, it seems from equation (12) that the simplest way to control the output voltage of the converter is by using duty ratio as the control input. however, the transfer function in equation (12) has zero in the right hand side. it is difficult to design linear controller which can satisfy small overshoot and fast time response specification. an alternative method is needed to design an appropriate controller. from equation (11) it is noticeable that the inductor current may be controlled using duty ratio as the control input. therefore, another method to control the output voltage of the converter is by using inductor current as the control input. from equations (11) and (12) the following transfer function can be derived; 𝑃3(𝑠) = 𝑥2(𝑠) 𝑥1(𝑠) = (1−𝐷)𝑉𝑜−(𝐿𝐼𝐿)𝑠 (𝐶𝑉𝑜)𝑠+2(1−𝐷)𝐼𝐿 (13) similar to equation (12), this transfer function also has zero in the right hand side which make it difficult to obtain good result using only linear feedback control. therefore, as an alternative method in this study in order to control the output voltage of the boost dc-dc converter two control loops are incorporated using current control loop in the inner loop and voltage control loop in the outer control loop. some assumptions were set to make it easier in designing both current controller and voltage controller. s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 108 figure 2 shows the current control loop which is designed in this study. current controller 𝐾1(𝑠) is designed so that the inductor current 𝑖𝐿 (𝑠) follows the given reference current 𝑖𝑟𝑒𝑓 (𝑠). the current controller 𝐾1(𝑠) receives current feedback signal 𝑦1(𝑠) from the current sensor 𝑆𝐴(𝑠). the current controller produces command signal 𝑢1(𝑠) to the pulse width modulator (pwm) 𝑀(𝑠) , then the pwm sends pulse command duty 𝑑(𝑠) to the switch of the boost dc-dc converter. a current sensing circuit was developed. based on experiment results, its relationship is given by the following equation; 𝑦1(𝑡) = −0.007𝑖𝐿 (𝑡) − 0.364 (14) pulse width modulation is realized using saw tooth signal as given below; 𝑣𝑀 (𝑡) = 𝑣𝐿 + (𝑣𝑈 − 𝑣𝐿 ) 𝑡 𝑇𝑠 (15) where 𝑣𝑈 and 𝑣𝐿 represent upper voltage limit and lower voltage limit of the modulation signal 𝑣𝑀 (𝑡). in this paper, the upper voltage limit and the lower voltage limit are set to be 6.3 v and 1.3 v, respectively. the peak to peak value of the modulation signal 𝑉𝑚𝑝𝑝 is 5 v. thus, transfer function of the modulator is given as follows; 𝑀(𝑠) = 1 𝑉𝑚𝑝𝑝 = 0.2 (16) from equations (11), (14) and (16) the total transfer function 𝑃1𝑇 (𝑠) from current control input 𝑢1(𝑠) to current feedback signal 𝑦1(𝑠) can be derived as follows; 𝑃1𝑇 (𝑠) = −2.5∙103(𝑠+72,6) 𝑠2+36.3𝑠+900.3∙103 (17) in this study, a current controller was designed using proportional and integral actions as below. this current controller is equipped with a low pass filter to filter out noise due to high frequency switching. 𝐾1(𝑠) = [𝐾𝑝 + 𝐾𝑖 𝑠 ] [ 1 1 𝜔𝑝 𝑠+1 ] (18) determining controller parameters values in equation (18) based on transfer function in equation (17) is rather complicated. in order to make it easier to calculate the controller parameter values, it was assumed that the deviation values of both input voltage and output voltage were substantially smaller than the value of output voltage itself. thus from the small signal model in equation (9) the effect of both the deviation values to the current can be neglected. as a result, the total transfer function 𝑃1𝑇 (𝑠) from current control input 𝑢1(𝑠) to current feedback signal 𝑦1(𝑠) can be simplified as below; 𝑃1𝑇𝑛 (𝑠) = 𝛼1 𝑠 (19) upon obtaining the simplified transfer function in equation (19), the current controller parameter values in equation (18) are determined. by setting cross over frequency value 𝜔𝑐 and phase angle margin value 𝛼, the current controller parameter values can be calculated using unity gain and phase angle margin relationships as commonly known in the conventional control theory based of frequency domain. |𝐾1(𝑠)𝑃1𝑇𝑛 (𝑠)|𝑠=𝑗𝜔𝑐 = 1 (20) tan(𝐾𝑖 + 𝐾𝑝𝑠)𝑠=𝑗𝜔𝑐 = tan(𝛼 − 𝜋) (21) the low pass filter parameter value 𝜔𝑝 is selected to suppress high frequency switching noise. table 2 shows an example of current controller parameter values (𝐾𝑝, 𝐾𝑖 , 𝜔𝑝) obtained using the above approach. the next step is designing a voltage controller. figure 3 shows voltage control loop used in this paper. the voltage controller 𝐾2(𝑠) is designed so that output voltage 𝑉𝑜(𝑠) tracks the given reference value 𝑉𝑟𝑒𝑓 (𝑠) . the voltage controller 𝐾2(𝑠) receives feedback signal 𝑦2(𝑠) from the voltage sensor 𝑆𝑇(𝑠) . the controller sends command signal 𝑢2(𝑠)to the current control loop 𝐶𝐶𝐿(𝑠), in turn current 𝑖𝐿 (𝑠)is delivered to 𝑃2(𝑠) to control the output voltage 𝑉𝑜(𝑠). for the sake of simplicity, it was assumed that the current control loop works well and that it was much faster than the voltage control loop. by imposing p1(s)k1(s) sa(s) m(s) iref(s) e1(s) u1(s) d(s) il(s) y1(s) figure 2. the designed current control loop p2(s)k2(s) st(s) ccl(s) vo(s)e2(s)vref(s) y2(s) il(s)u2(s) figure 3. the designed voltage control loop table 2. an example of current controller parameter values parameter value unit proportional gain: 𝐾𝑝 3.06 integral gain: 𝐾𝑖 36773 low pass filter frequency: 𝜔𝑝 65940 rad/sec s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 109 this assumption into the average small signal model, the following simplified transfer function from inductor current to output voltage can be derived; 𝑃2(𝑠) = 𝛽1 𝑠+𝛽2 (22) by observing equation (22), in this study a controller is designed of the form low pass filter (lpf). the parameter values of the controller were determined by taking into account the desired cut off frequency, steady state error and oscillation damping. after some calculation, the following output voltage controller 𝐾2(𝑠) is obtained. 𝐾2(𝑠) = 88556 𝑠+708 (23) iv. implementation results and discussion figure 4 shows a photo of the developed boost dc-dc converter. high frequency switching is realized using n-channel power mosfet ixfh50n60p3 while the soft start switch uses thyristor skkl 92. the controller is realized using both analog and digital circuits. some experiments have been conducted in order to verify the effectiveness of the developed boost dc-dc converter control system. the power source was realized using 10 lead acid batteries connected in series to provide 120 v input voltage. each battery has the capacity of 45 ah. experiments were carried out in some cases including start up without load and sudden load variations (352 w, 1,042 w, and 1,393 w). signals of concern were measured using available oscilloscope and multi tester. figure 5 shows the experimental result when the boost converter starts working. the horizontal axis indicates time in second and the vertical axis is voltage in volt from each sensor. the red line represents output voltage of the boost converter while the blue line expresses inductor current. from this figure it can be noted that the boost converter could elevate the output voltage from initial value around 120 v to steady state voltage around 240 v. this happens because the controller generates pulses command which is reflected in the inductor current ripple as shown in the figure. after having reached the steady state condition the controller stops generating pulses command continuously. it only produces pulses command when it is needed to compensate power losses. figure 6 to 9 show the experimental results when the boost dc-dc converter is loaded with certain load. the horizontal axis indicates time in second and the vertical axis is voltage in volt from each sensor. figure 6 demonstrates experimental result when the converter is suddenly loaded with a small halogen lamp. the red line represents output voltage while the blue line expresses inductor current. it can be seen that figure 5. output voltage response during start up s0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 v -10 -8 -6 -4 -2 0 2 4 6 8 10 v -10 -8 -6 -4 -2 0 2 4 6 8 10 x=620mv ch a: dc voltage(mv) 755.3 ch b: dc voltage(mv) 2227 ch a: frequency(hz) not enough data ch b: frequency(hz) 112.0 13jun2015 13:13 (a) (b) figure 4. the developed boost dc-dc converter; (a) battery string; (b) boost dc-dc converter s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 110 the output voltage is maintained at constant value. at the instant when the load is added a quite small voltage drop exists but it is soon recovered to the reference value. large current rise indicates the effort of the controller to compensate the sudden voltage drop. under loaded condition, the controller continuously sends pulse width modulator command to deliver current from the energy source to the load while maintaining the output voltage at the reference value. the average current flowing through the inductor at the steady state condition was around 0.576 mv which corresponded to 2.94 a. measurement using a multi meter showed that at the steady state under the load, the input and ouput voltages were 119.6 v and 241.6 v respectively. thus the power quantity of the small halogen lamp was around 352 w. figures 7 and 8 demonstrate experimental result when the converter was suddenly loaded with a large halogen lamp. in figure 7, the red line represents output voltage of the boost converter while the blue line expresses inductor current. at the instant when the load was added to the converter a voltage drop existed but it was gradually recovered. once a large current rise was noticeable but it soon diminished since the current protection mechanism took place to protect the system. after a while the current rises again to compensate the voltage drop. under loaded condition, the controller continuously sends pulse width modulator command to deliver current from the energy source to the load while maintaining the output voltage at the reference value. the average current flowing through the inductor at the steady state condition was around figure 6. ouput voltage and inductor current under small halogen lamp load figure 7. ouput voltage and inductor current under large halogen lamp load s0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 v -10 -8 -6 -4 -2 0 2 4 6 8 10 v -10 -8 -6 -4 -2 0 2 4 6 8 10 x=1198mv,o=620mv,xo=-578mv ch a: dc voltage(mv) 1138 ch b: dc voltage(mv) 2987 ch a: frequency(hz) 424.9 ch b: frequency(hz) not enough data 13jun2015 13:17 s0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 v -10 -8 -6 -4 -2 0 2 4 6 8 10 v -10 -8 -6 -4 -2 0 2 4 6 8 10 ch a: dc voltage(mv) 489.6 ch b: dc voltage(mv) 2954 ch a: frequency(hz) 351.0 ch b: frequency(hz) not enough data 13jun2015 13:40 s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 111 8.71 a. measurement using a multi meter showed that at the steady state under the load, the voltage input was 119.6 v and the voltage output was 241.6 v. the power of the large halogen lamp was around 1,042 w. in figure 8 the red line shows pulse width modulation output of the controller while the blue line demonstrates inductor current under steady state condition with load. it can be noted that when the switch was closed (pwm “high”) the inductor current rose, oppositely when the switch was open (pwm “low”) the inductor current went down. this result demonstrates that the controller works in continuous current mode control. the switching frequency was around 62.33 khz and the period of switch on was around 8.22 µs which corresponded to duty ratio of 51.2%. figure 9 shows experimental result when the converter is loaded with the large and the small halogen lamp in parallel concurrently. the red line shows pulse width modulation output of the controller while the blue line demonstrates inductor current under steady state condition. when the switch was closed (pwm “high”) the inductor current rose, oppositely when the switch was open (pwm “low”) the inductor current went down. the average inductor current was around 11.65 a which corresponded to 1,393 w. the switching frequency was around 62.42 khz and the period of switch on was around 8.37 µs which corresponded to duty ratio of 52.2%. figure 8. controller output pwm and inductor current under large halogen lamp load figure 9. controller output pwm and inductor current under load of the large and small halogen lamps in parallel µs0 10 20 30 40 50 60 70 80 90 100 v -10 -8 -6 -4 -2 0 2 4 6 8 10 v -20 -16 -12 -8 -4 0 4 8 12 16 20 x=27,85µs,o=19,64µs,xo=-8216ns ch a: dc voltage(mv) 2472 ch b: dc voltage(mv) 6084 ch a: frequency(khz) 62.18 ch b: frequency(khz) 62.33 13jun2015 13:33 xo µs0 10 20 30 40 50 60 70 80 90 100 v -10 -8 -6 -4 -2 0 2 4 6 8 10 v -20 -16 -12 -8 -4 0 4 8 12 16 20 x=28,87µs,o=37,24µs,xo=8373ns ch a: dc voltage(mv) 3047 ch b: dc voltage(mv) 6189 ch a: frequency(khz) 177.1 ch b: frequency(khz) 62.42 13jun2015 14:44 x o s. kasbi et al. / j. mechatron. electr. power veh. technol. 06 (2015) 105-112 112 there was no much difference in duty ratio between these two cases. this is because the ratio between output voltage and input voltage were almost the same. these experiment results are in line with equation (8). v. conclusion from the experimental results the following conclusion can be drawn. during the start up without any load the developed boost dc-dc converter can elevate input voltage of 119.6 v to output voltage of 241.6 v. the developed controller can regulate the output voltage of the boost converter smoothly under load variation from no load to sudden load of 352 w. these results prove that the pi controller in the current loop and the lpf controller in the voltage loop work well. when large sudden load change happens from 0 w to 1,042 w the output voltage experiences small drop wich proves that the current protection works well. afterwards the ouput voltage is recovered to 241.6 v. there is no significant difference of duty ratio between different conditions under load variations in steady state condition. this is because the ratio between the output voltage and the input voltage is almost the same. it can be concluded that the developed control system satisfies the design specification. acknowledgement the authors thank to universiti teknologi malaysia (utm) kuala lumpur, the indonesian institute of sciences (lipi), and the ministry of energy and mineral resources of the republic of indonesia for providing conducive circumstances to carry out this research activity. references [1] m.a. abdullah et al., “input current control of boost converters using current-mode controller integrated with linear quadratic regulator,” international journal of renewable energy research, vol. 2, no.2, pp.262-268, 2012. [2] t.k. hassan, “a repetitive pi current controller for boost single phase pfc converters”, energy and power engineering, vol.3, pp.69-78, 2011. [3] q. tong et al., “a sensorless predictive current controlled boost converter by using an ekf with load variation effect elimination function”, sensors, vol.15, pp.9986-10003, 2015. [4] g.s. rao et al., “design of feedback controller for boost converter using optimization technique”, international journal of power electronics and drive system, vol.3, no.1, pp.117-128, 2013. [5] a.g. beccuti et al., “optimal control of the boost dc-dc converter”, proceedings of the 44 th ieee conference on decision and control, and the european control conferences, spain, dec.12-15, pp.44574462, 2005. [6] yoshihiro and k. higuchi, “robust digital control for boost dc-dc converter,” transactions on electrical engineering, electronics, and communications, vol. 10, no.1, pp. 68-73, 2012. [7] h. sira-ramirez and m. rios-bolivar, “sliding mode control of dc-to-dc power converters via extended linearization,” ieee transactions on circuits and systemsi: fundamental theory and applications, vol. 41, no.10, pp. 652-661, 1994. [8] b. allaoua et al., “a robust fuzzy sliding mode controller synthesis applied on boost dc-dc converter power supply for electric vehicle propulsion system,” international journal of vehicular technology, vol. 2013. [9] m.z. romdlony and amin, “design and implementation of anti-windup pi control on dc-dc bidirectional converer for hybrid vehicle applications,” journal of mechatronics, electrical power and vehicular technology, vol. 3, no.1, pp.31-38, 2012. [10] s. aji et al., “mppt based on fuzzy logic controller for photovoltaic system in solar car,”, journal of mechatronics, electrical power and vehicular technology, vol. 4, no.2, pp.127-134, 2013. mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2017.v8.70-75 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study yukhi mustaqim kusuma sya’bana a, b, *, kadek heri sanjaya b, muhammad redho kurnia b, james shippen c a industrial design, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, south korea b research centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu/sangkuriang, bandung 40135, indonesia c department of mechanical and automotive engineering, coventry university coventry cv1 5fb, united kingdom received 14 march 2017; received in revised form 21 november 2017; accepted 23 november 2017 published online 28 december 2017 abstract this is the preliminary finding of a study to simulate lumbar and neck flexion while ingress to the paratransit. the result of simulation will determine design aspect criteria as a preliminary step before ideation and implementation design steps. biomechanics of bodies (bob) is software that used to represent passenger task during paratransit ingress simulation, with skeleton model that used is height 165 cm and weight 65 kg. environment to represent this simulation is measured suzuki carry ss 2013 as a private car that has been modified into a public transportation in accordance with the indonesian government roadworthy test. due to the low height of the entrance and the high ground clearance, lumbar and neck joint angle was a focus of this ingress simulation. the peak angle at the neck joint is 40° when 2 s skeleton nod in the door limitation ingress and lumbar flexion is 70° when 5 s skeleton is walking while bend over that will increase the load on that area. based on biomechanical simulation approach, we may suggest the dimension of public transportation design framework developments, especially paratransit. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: paratransits ingress; angkot; product design process; biomechanical simulation. i. introduction paratransits, which is called angkot in indonesia are the connector of larger public transportation vehicle such as bus and train, are very common in developing countries in asia and africa. figure 1 shows the example of paratransit in bandung, indonesia, the city that in 2014 has total number 5521 units of paratransit, 39 different routes, and distances between 7 – 24.35 km [1]. the attraction of paratransit to passengers is decreasing due to the increasing number of private vehicles [2], [3]. there are various issues on paratransits in such as limited access for the elderly and passengers with a disability. these vehicles have fixed routes without fixed schedule trip and stop on demand from the passengers; nevertheless paratransits still stand to be a public transportation due to the other factors such as, affordable of the payment rates, individual ownership that allows the development of * corresponding author. tel: +81 221 886 22 e-mail address: yukh001@lipi.go.id figure 1. suzuki ss 2014 as one of bandung paratransit https://dx.doi.org/10.14203/j.mev.2017.v8.70-75 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.70-75 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.70-75&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ y.m.k. sya’bana et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 71 small entrepreneurship, as well as the dispersed urban planning spaces for such vehicle to operate. the aspects that are necessary to be given attention in order to improve paratransits systems in many countries are the quality of services, the role of government, the promotion of electric paratransits and integration with mass transit systems and the concept of human mobility as a whole [4], [5]. existing paratransit standardization refers to the terms of the road-worthiness test according to the indonesian government rules [6], [7]. in our research centre, there are efforts to improve the paratransits by performing modifications on an existing angkot driven by both environmental and ergonomics issues. the efforts were performed by converting the propulsion system from internal combustion engine into an electric propulsion system and modification of passenger cabin dimension, especially the cabin height to make it more comfortable for ingress and egress [8]. however, it was constrained by the floor of the passenger cabin that was too high due to the light truck basic chassis of the vehicle [8]. it is possible to change the conventional combustion engine paratransit becomes an electric vehicle (ev) with estimating the total energy consumption and demand at each charging station [9]. mock up scale of future electric paratransit concept has been done with features include folding seat, accommodation of disabilities passenger, priority seat and standing positions. nevertheless, the concept still used existing high ground clearance without considering standardization measurement through systematic human factor study [10]. in a previous study that can be used as a reference, an automated urban mobility system with low floor concept is able to accommodate 12 standing passengers and 12 seats, and an allowance for 1 wheelchair space inside of a compact vehicle of only 5 meters long [11]. in another study, the design concept of paratransits transportation payment was introduced [12]. it was using an integrated payment system based on the distance that recorded from the time when the passenger passes the entrance door and to the time when the passenger leaves the exit door, this effort was performed to speed up the payment process and to reduce traffic congestion [12]. study of activities that related to the paratransit either the vehicles, facilities, infrastructures, and users, both direct and indirect are the reference for a designer to improve paratransit design [13]. the definition of good designs are designs that can accommodate the needs of users through an empathic designing approach [14]. in this case, those public transportations must accommodate users with special needs such as an elderly user or people with disabilities, and parents with a baby stroller. thus paratransit design must fulfill “design for all” criteria according to the particular posture, not limited to separated design for the small, mean, or for the tall users [15]. one critical point in passengers’ activities while using a paratransit is walking to enter the vehicle or ingress. during ingress, the passenger should flex the trunk and the knee, followed by lifting the foot onto the vehicle entrance. because of the low height of the entrance and the high ground clearance, ingress can be considered the most uncomfortable activity in the paratransit. the neck flexion degree positions are significantly affecting neck pain cause [16]. fear of falling as injury factor is the one of elderly risk on mobility activities including stairs issues and walking without assistance [17]. the biomechanics simulations ingress and egress as a driver scene have conducted to predict an effective motion analysis [18]–[23]. however, behaviours of elderly people and people with an impairment may be difficult to classify in a simulation [24]. we did not find any specific reference with regard to biomechanical study on angkot ingress. however, previous studies have reported the greater low back muscular load during trunk flexion both in static [25] and dynamic [26] condition. the purpose of this study is to determine and assess biomechanical aspect during ingress of angkot especially to explore the risk of lower back injury, the eligibility of empathic design approach and to provide a preliminary research design to improve the paratransits design in indonesia by means of computer biomechanical simulation. ii. research method the study plan consists of four main phase process as follows: inspiration, preliminary, ideation and implementation as shown in figure 2. first step is inspiration process that consists of literature study to make a better paratransit design from the state of the art findings. design aspect study which consists of ergonomic approach study by performing biomechanics of bodies (bob) simulation is the part of the second phase that is a preliminary phase. thus, the result of simulation will determine design aspect criteria as a preliminary step for the design improvement. the third step is ideation that consists of design product process; this process is conducted before the final step that is an implementation to make a product, mock-up and prototyping. in this article, we will describe the first two phases of the study plan. variables of biomechanical measurement and assessment methods, especially in transportation field could be conducted with some measuring tools i.e. load cell, force plate, pressure sensor, motion analysis, figure 2. this study methodology inspiration • literature study preliminary • design aspects study (ergonomic) bob simulation • design aspects criteria ideation • design product process implementation • product/prototype y.m.k. sya’bana et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 72 electromyography, and many more [27]. the study was conducted by measuring some parameters and learn about how to measure time, movement and biomechanics skeleton model when entering paratransit. computer simulation is used to represent the movement when the passenger takes a step into the paratransit toward the passenger seat. biomechanics of bodies software by james shippen which is usually combined with a motion capture system is used to quickly answer biomechanics issues like dancing, vehicle egress, ingress and many more. skeleton model has major anatomical components that are representing 31 segments that were connected with 35 joints, 666 locomotor muscle units and maximal isometric load that is characterized [28]–[33]. in this study, we also measured paratransit that was based on suzuki carry ss 2013 which is one of the privately owned vehicles that has been operated to be a paratransit in indonesia, with the aim is to use it as the reference for the environment of biomechanical study simulation. measurement of body segments movements and joint motion angles are examined with regard to time/second (s), and through the simulation, we determine the peak angle of lumbar and neck angle flexion during paratransit ingress. the data of skeleton and paratransit entrance dimension were used to determine the limit points between the entrance door and head clearance of paratransit cabin ceiling, the height of footstep, the height of the seat cushion and another environment on paratransit as shown in figure 3. there are anatomical body landmarks that are specifically calculated based on time, axis, transition and rotation which include head, neck, shoulder, elbow, hip, pelvis, lumbar, knee and ankle. the components of paratransit dimension that related to ingress activity were also measured as shown in figure 4. the components include inner width between back cushion, depth of seat cushion, inner width between base cushion, width of entrance sidestep, vehicle width, interior ceiling width, seat height, height of passenger cabin, height of door from cabin deck, height of entrance sidestep, sidestep height from ground, width of entrance door, length of left base seat and length of right base seat. the measurement was intended to know spatial limitations in simulating body movements as shown in table 1. figure 5 shows that for this study, the simulation was using the biomechanics of bodies, custom-built software which was developed within matlab® (the mathworks inc™) environment. skeleton model that was used in the simulation assumed with height 165 cm and weight 65 kg without age specification option provided, which represents 50th percentile of indonesian anthropometric [34]. the direction of rotation and axis displacement of the human body model was simulated according to the coordinates in the three axes of x, y, and z. red arrow is x-axis, the green arrow is y-axis, and blue arrow is z-axis. for joint angles articulation in non-translation movement, figure 4. paratransit ingress joint angle points figure 3. paratransit and stature of human model measured variables table 1. the dimension of suzuki carry ss 2013 paratransit and human model variable measured variable dimension (cm) a inner width between back cushion 103,5 b depth of seat cushion 31 c inner width between base cushion 72,7 d width of entrance sidestep 19,5 e vehicle width 139 f roof width 90 g seat high 28 h height of passenger cabin 129 i height of door from cabin deck 107 j height of entrance sidestep 25 k sidestep height from ground 37,5 l width of entrance door 69,5 m length of left base seat 144 n length of right base seat 230 o stature of bob model 165 y.m.k. sya’bana et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 73 red arrow represents axis 3, green arrow represents axis 2, and blue arrow represents axis 1. the ingress of paratransit period used in the simulation was that it was conducted within 12 seconds (s) duration. the commands and movements were customized with regard to the time axis, coordinate transitions and joints angle rotation that makes the skeleton model of the body able to represents the movement in the paratransit ingress more realistically. we consider the dynamic postures during movement can be calculated by a series of static postures during certain time references. iii. result and discussion figure 6 illustrates the overall neck joint angle while paratransit ingress movement for the period 12 s while entering the paratransit. neck angle peak achieved in the first 2 s that is 30° and withstand up to 3 s that is beginning to enter the paratransit passenger cabin door. afterward, a slight reduction to 20° was occurred on the last 4 s and then stable up into 11 s when walking into the inside of paratransit and eventually fell back down to 10° in 12 s, i.e. while sitting in the vehicle. this data suggest that the greatest neck flexor muscles load occurs at the earliest stage of ingress. neck flexion or cranio-cervical flexion among people with chronic neck pain has been reported to affect postural control and proprioception [35]. craniocervical flexion also affects gaze. thus, the awareness of head position is also affected, which may be hazardous during entering a narrow place like the paratransit. the condition of pressure and isometric strength of neck flexors and extensors muscles are also reported to be closely related to certain type of a headache [36], [37]. the difficult situation in ingress is not only faced by subjects with chronic neck pain, but also by healthy subjects with neck flexor muscles fatigue [38]. we speculate that the narrow design of the paratransit ingress can be harmful to users with the limitation on neck muscles condition as well as the subject with the larger size of anthropometry. figure 7 shows that the lumbar joint angle flexion was increasing from 0° to 30° in 3 s during the early stage of entering the paratransit, when the body is positioned to start to take a step into the side steps of paratransit. the position of other body landmarks are: left ankle axis1 (-10°), left hip axis2 (15°), right hip axis2 (-60°), left hip axis2 (15°), left shoulder axis1 (90°), left shoulder axis2 (-30), right shoulder axis1 (90°), right shoulder axis2 (15°), left elbow axis1 (-60°), right elbow axis1 (-60°), neck joint axis2 (30°), left front head axis2 (15°), and pelvis transition-x (0.3°). at the 5 s time point, the peak of the lumbar joint angle flexion is up to 70° where the position of pelvis translation-x (0.5°), pelvic transition-z (0.4°) and pelvic rotation-z (-90°), which means that the body orientation was turned to the right with the turning radius 90° toward the seating position. lumbar joint angle began to decline dramatically in the last two seconds after the time point of 10 s which is the body orientation was figure 7. lumbar joint angle flexion axis-2 (red) while ingress paratransit results figure 6. neck joint angle flexion axis-2 (red) while ingress paratransit results figure 5. bob skeleton model axis [30] y.m.k. sya’bana et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 74 rotated to 180°, preparing to sit down after turn, and adjusting the direction of seat position, with joint motion data as follows: lumbar joint axis2 (70°), left hip axis2 (-10°), right hip axis2 (20°), right knee axis2 (20°), left knee axis2 (20°), left shoulder axis1 (90°), left shoulder axis2 (-30°), right shoulder axis1 (-90°), right shoulder axis2 (-30°), pelvis trans-x (0.7°), pelvis trans-y (-0.7), pelvis rot-z (-180°), neck joint axis2 (20°), left ankle axis1 (-10°), and right ankle axis1 (10°). lumbar position at the time point of 12 s is the last lumbar position to 0° that have been in seating position on paratransit seat, with the joint motion data as follows: right hip axis2 (-120°), right knee axis2 (120°), left knee axis2 (120°), left shoulder axis1 (90°), left shoulder axis2 (0°), right shoulder axis1 (-90°), right shoulder axis2 (0°), pelvis trans-x (1.2°), pelvis trans-y (-0.7°), pelvis trans-z (-0.2°), pelvis rot-z (180°), neck joint axis2 (10°), and left hip axis2 (-120°). meanwhile, the angle of both of knees axis are flexed up to (120°), both hips (-120°) and both ankles (-40°) while seated and trip with paratransit. in a previous study on static postures, lumbar flexion angles were found to be linear with lumbar erector spinae muscular activation up to 45° [25]. erector spinae muscle is responsible for maintaining body posture with regard to balance during locomotion [26], [39]. the data of this simulation study may suggest that the greatest muscle load occurs right after the entrance to right before taking a seat. in a coordinated movement, a movement of one part of the body will affect the other part. the spinal condition has been reported to interact with both upper and lower limb muscle with regard to fatigue [40]. gait characteristics also affect lumbar muscular load [41], [42]. step width was also reported to be related to flexion-relaxation phenomenon of the lumbar muscles [43]. therefore, the narrow width of the entrance provides another challenge for the passengers. as both lumbar and neck flexor-extensor muscles are very crucial for maintaining balance, walking while stooping inside the paratransit should require greater work from those muscles. moreover, the anthropometry data of many subjects with distinctive characteristics, like indonesia as a country of angkot user, should be measured on every particular body parts [44]. iv. conclusion this study shows that it is possible to make a simulation using software biomechanics of bodies to measure ingress lumbar and neck angle flexion while ingress of paratransit in indonesia. the data show that the largest angle at the neck joint for cervo-cranial flexion is 30° which occurs between the 2 s to 4 s due to narrow entrance and lumbar flexion is 70° started at 5 s from the start of walking due to bending the trunk over that increases the lumbar muscular load. based on this biomechanical simulation, we may suggest that the dimension of the entrance of the existing paratransit is very narrow and may lead to greater musculoskeletal load for the passengers. as a preliminary study, we have suggested that the dimension of the entrance and passenger cabin on public transportation design development especially angkot should be enlarged so that the passengers do not have to flex their body parts excessively. biomechanical simulation allows the consideration to improve the paratransit design based on human factors data in a more rapid and efficient way. however, as this study is still at the preliminary stage, further studies are required. in the future, we will enhance more simulation of various anthropometry data followed by laboratory experiment using motion capture system and electromyography (emg) analysis to makes more accurate analysis. as the software of bob is still under development, its quality will be improved by comparison between simulation and laboratory experiment. acknowledgement we are grateful to research center for electrical power and mechatronics (rcepm-lipi) as my institution, dr. james shippen, prof. andrew parkes, dr. cyriel diels from coventry university for the useful discussion. references [1] dinas perhubungan kota bandung, “trayek angkutan kota di kota bandung,” 2014. [online]. available: http://data.go.id/dataset/trayek-angkutan-kota-di-bandung. [2] cecep wijaya, “tren penggunaan angkot menurun, 33 trayek mati,” 28-sep-2014. [3] badan pusat statistik, “perkembangan jumlah kendaraan bermotor menurut jenis, 1949-2015,” 2015. [online]. available: https://www.bps.go.id/linktabledinamis/view/id/1133. [4] t. b. joewono, “the characteristics of paratransit and nonmotorized transport in bandung, indonesia,” vol. 6, pp. 262– 277, 2005. [5] r. lave and r. mathias, “state of the art of paratransit,” building, pp. 1–7, 1990. [6] presiden republik indonesia, “peraturan pemerintah republik indonesia nomor 55.” 2012. [7] direktorat jendral perhubungan darat, “peraturan pemerintah republik indonesia nomor 43 tahun.” 1993. [8] m. redho, “angkot design modification; based on conversion from conventional engine to electric drive,” int. conf. sustain. energy eng. appl. (icseea), sustain. energy green mobil., pp. 19–26, 2014. [9] n. huda et al., “estimating power needed to fuel electric paratransits in bandung,” j. mechatronics, electr. power, veh. technol., vol. 6, no. 2, p. 123, 2015 [10] r. wisaksono, “pengembangan desain angkutan kota sebagai transportasi,” itb undergrad. j. vis. art des., vol. 4, no. 1, pp. 1–8, 2015. [11] a. ponsford and m. kunur, “the mobilicity ppt automated urban mobility system ‘see the future today,’” world electr. veh. j., vol. 1, no. 1, pp. 264–270, 2007. [12] m. fauzi et al., “perangkat pendukung pembayaran angkutan umum kota bandung dengan sistem integrasi,” itb undergrad. j. vis. art des., vol. 4, no. 1, pp. 1–9, 2015. [13] k. h. sanjaya and m. redho, “identifikasi aspek ergonomi dalam angkutan umum,” in national proceeding of ergonomi. bandung, 2007, pp. 36–52. [14] j. thomas and d. mcdonagh, “empathic design: research strategies.,” australas. med. j., vol. 6, no. 1, pp. 1–6, 2013. [15] m. johan and de b. renate, “enhancing the use of anthropometric data,” in human factors in design, safety, and management, maastricht, the netherlands: shaker publication, 2005, pp. 289–297 [16] g. a. m. ariens, “are neck flexion, neck rotation, and sitting at work risk factors for neck pain? results of a prospective cohort study,” occup. environ. med., vol. 58, no. 3, pp. 200–207, 2001. http://data.go.id/dataset/trayek-angkutan-kota-di-bandung http://data.go.id/dataset/trayek-angkutan-kota-di-bandung http://data.go.id/dataset/trayek-angkutan-kota-di-bandung http://www.pikiran-rakyat.com/bandung-raya/2014/09/02/295217/tren-penggunaan-angkot-menurun-33-trayek-mati http://www.pikiran-rakyat.com/bandung-raya/2014/09/02/295217/tren-penggunaan-angkot-menurun-33-trayek-mati https://www.bps.go.id/linktabledinamis/view/id/1133 https://www.bps.go.id/linktabledinamis/view/id/1133 https://www.bps.go.id/linktabledinamis/view/id/1133 https://www.bps.go.id/linktabledinamis/view/id/1133 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.590.7030&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.590.7030&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.590.7030&rep=rep1&type=pdf http://onlinepubs.trb.org/onlinepubs/millennium/00107.pdf http://onlinepubs.trb.org/onlinepubs/millennium/00107.pdf https://smalbncilacap.files.wordpress.com/2013/05/pp_no_55_2012-tt-kendaraan.pdf https://smalbncilacap.files.wordpress.com/2013/05/pp_no_55_2012-tt-kendaraan.pdf http://hubdat.dephub.go.id/peraturan-pemerintah/79-pp-no-43-tahun-1993-tentang-prasarana-dan-lalu-lintas-jalan http://hubdat.dephub.go.id/peraturan-pemerintah/79-pp-no-43-tahun-1993-tentang-prasarana-dan-lalu-lintas-jalan http://proceeding.icseea.org/index.php/icseea/icseea2014/paper/view/27/26 http://proceeding.icseea.org/index.php/icseea/icseea2014/paper/view/27/26 http://proceeding.icseea.org/index.php/icseea/icseea2014/paper/view/27/26 http://proceeding.icseea.org/index.php/icseea/icseea2014/paper/view/27/26 http://dx.doi.org/10.14203/j.mev.2015.v6.123-128 http://dx.doi.org/10.14203/j.mev.2015.v6.123-128 http://dx.doi.org/10.14203/j.mev.2015.v6.123-128 http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/575 http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/575 http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/575 https://id.scribd.com/document/258783346/the-mobilicity-ppt-automated-urban-mobility-system-see-the-future-today-alan-ponsford-merih-kunur-weva https://id.scribd.com/document/258783346/the-mobilicity-ppt-automated-urban-mobility-system-see-the-future-today-alan-ponsford-merih-kunur-weva https://id.scribd.com/document/258783346/the-mobilicity-ppt-automated-urban-mobility-system-see-the-future-today-alan-ponsford-merih-kunur-weva http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/562/480 http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/562/480 http://jurnal-s1.fsrd.itb.ac.id/index.php/product/article/view/562/480 https://www.researchgate.net/publication/304351240_identifikasi_aspek_ergonomi_dalam_angkutan_umum_dalam_kota_angkot https://www.researchgate.net/publication/304351240_identifikasi_aspek_ergonomi_dalam_angkutan_umum_dalam_kota_angkot https://www.researchgate.net/publication/304351240_identifikasi_aspek_ergonomi_dalam_angkutan_umum_dalam_kota_angkot https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3575059/ https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3575059/ https://www.researchgate.net/publication/299913408_the_effects_of_mindfulness_on_acute_pain_examination_of_brief_training_and_individual_differences https://www.researchgate.net/publication/299913408_the_effects_of_mindfulness_on_acute_pain_examination_of_brief_training_and_individual_differences https://www.researchgate.net/publication/299913408_the_effects_of_mindfulness_on_acute_pain_examination_of_brief_training_and_individual_differences https://www.researchgate.net/publication/299913408_the_effects_of_mindfulness_on_acute_pain_examination_of_brief_training_and_individual_differences https://dx.doi.org/10.1136%2foem.58.3.200 https://dx.doi.org/10.1136%2foem.58.3.200 https://dx.doi.org/10.1136%2foem.58.3.200 y.m.k. sya’bana et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 70–75 75 [17] m. auais, b. e. alvarado, c. l. curcio, a. garcia, a. ylli, and n. deshpande, “fear of falling as a risk factor of mobility disability in older people at five diverse sites of the imias study,” arch. gerontol. geriatr., vol. 66, pp. 147–153, 2016. [18] m. p. reed and s. huang, “modeling vehicle ingress and egress using the human motion simulation framework,” sae technical paper, no. 2008–01–1896. pittsburgh, pennsylvania, pp. 1–12, 2008 [19] p. pudlo et al., “prediction of the car entering motion,” sae tech. pap., no. 724, 2006 [20] t. robert et al., “a 3-d dynamics analysis of driver’s ingressegress motion,” in sae technical paper digital human modeling for design and engineering, 2013, pp. 1–8, 2009. [21] j. causse et al., “effects of roof height on car ingress/egress movement,” sae technical papers, no. june. researchgate, pp. 1–8, 2011. [22] j. causse et al., “dynamic analysis of car ingress / egress movement : an experimental protocol and preliminary results,” sae int. j. passeng. cars mech. syst., vol. 2, no. 1, pp. 1633– 1640, 2009 [23] f. dufour, “discomfort assessment of car ingress / egress motions using the concept of neutral movement approach discomfort,” sae tech. pap., vol. 2005–01–27, no. 724, pp. 1–11, 2005 [24] e. chateauroux and x. wang, “a database of ingress / egress motions of elderly people,” sae tech. pap. digit. hum. model. des. eng., no. 2007–01–24, 2007. [25] k. sanjaya et al., “the effects of different trunk inclinations on bilateral trunk muscular activities, centre of pressure and force exertions in static pushing postures,” j. hum. ergol. (tokyo)., vol. 43, pp. 9–26, 2014. [26] k. h. sanjaya et al., “the influence of laterality on different patterns of asymmetrical foot pressure and muscle activation during gait cycle in manual pushing,” j. hum. ergol. (tokyo)., vol. 43, pp. 77–92, 2014. [27] k. h. sanjaya and y. m. k. sya’bana, “conceptual framework on the application of biomechanical measurement methods in driving behavior study,” in aip conference proceedings, 2017, p. 40002. [28] b. may and j. shippen, “visualisation of dance performance using 3-dimensional motion tracking and muscle modelling techniques,” in visual and performing arts, 2012, no. february, pp. 329–342 [29] s. bronner and j. shippen, “biomechanical metrics of aesthetic perception in dance,” exp. brain res., vol. 233, no. 12, pp. 3565–3581, 2015 [30] j. shippen, “biomechanical analysis of entry , egress and loading of a passenger vehicle with rear hinged rear doors,” international j. traffic transp. eng., vol. 1, no. october 2016, pp. 107–117, 2012 [31] j. shippen, “biomechanical analysis of entry , egress and loading of a passenger vehicle with rear hinged rear doors,” international j. traffic transp. eng., vol. 1, no. october 2016, pp. 107–117, 2012 [32] j. shippen and b. may, “a kinematic approach to calculating ground reaction forces in dance.,” j. dance med. sci., vol. 16, no. 1, pp. 39–43, 2012. [33] j. shippen and b. may, “teaching biomechanical analysis using the bob matlab/simulink model,” coventry university, uk., 2013. [online]. available: https://pdfs.semanticscholar.org/7477/cf303cf7e4dff328edfc64 203986d2474a3d.pdf [34] “antropometri indonesia, rekap data antropometri indonesia.” [online]. available: http://antropometriindonesia.org/index.php/detail/artikel/4/10/ data_antropometri . [35] t. gallego izquierdo et al., “comparison of cranio-cervical flexion training versus cervical proprioception training in patients with chronic neck pain: a randomized controlled clinical trial,” j. rehabil. med., vol. 48, no. 1, pp. 48–55, 2016 [36] r. castien et al., “pressure pain and isometric strength of neck flexors are related in chronic tension-type headache,” pain physician, no. 18, pp. 201–206, 2015 [37] l. l. florencio et al., “patients with chronic, but not episodic, migraine display altered activity of their neck extensor muscles,” j. electromyogr. kinesiol., vol. 30, no. june, pp. 66–72, 2016. [38] c. h. cheng et al., “changes of postural control and muscle activation pattern in response to external perturbations after neck flexor fatigue in young subjects with and without chronic neck pain,” gait posture, vol. 41, no. 3, pp. 801–807, 2015. [39] k. h. sanjaya, “biomechanical study on laterality during manual pushing and locomotion,” chiba university, 2015. [40] s. k. sidhu et al., “spinal μ-opioid receptor-sensitive lower limb muscle afferents determine corticospinal responsiveness and promote central fatigue in upper limb muscle.,” j. physiol., vol. 592, no. 22, pp. 5011–24, 2014. [41] s. sasada et al., “volitional walking via upper limb musclecontrolled stimulation of the lumbar locomotor center in man,” j. neurosci., vol. 34, no. 33, pp. 11131–11142, 2014. [42] t. k. rupp et al., “a forward dynamics simulation of human lumbar spine flexion predicting the load sharing of intervertebral discs, ligaments, and muscles,” biomech. model. mechanobiol., vol. 14, no. 5, pp. 1081–1105, 2015. [43] b. hu et al., “the effects of stance width and foot posture on lumbar muscle flexion-relaxation phenomenon,” clin. biomech., vol. 29, no. 3, pp. 311–316, 2014. [44] y. mustaqim et al., “camouflage design and head measurement characteristic of indonesian armoured vehicle helmet,” in science and nanotechnology science and nanotechnology aip conference proceedings, 2017, vol. 300751, no. 10. https://doi.org/10.1016/j.archger.2016.05.012 https://doi.org/10.1016/j.archger.2016.05.012 https://doi.org/10.1016/j.archger.2016.05.012 https://doi.org/10.1016/j.archger.2016.05.012 https://doi.org/10.4271/2008-01-1896 https://doi.org/10.4271/2008-01-1896 https://doi.org/10.4271/2008-01-1896 https://doi.org/10.4271/2008-01-1896 https://doi.org/10.4271/2006-01-2357 https://doi.org/10.4271/2006-01-2357 https://sites.google.com/site/dhmsymposium/dhm2013_submission_18.pdf https://sites.google.com/site/dhmsymposium/dhm2013_submission_18.pdf https://sites.google.com/site/dhmsymposium/dhm2013_submission_18.pdf https://www.researchgate.net/publication/283123219_effects_of_roof_height_on_car_ingressegress_movement https://www.researchgate.net/publication/283123219_effects_of_roof_height_on_car_ingressegress_movement https://www.researchgate.net/publication/283123219_effects_of_roof_height_on_car_ingressegress_movement https://doi.org/10.4271/2009-01-2309 https://doi.org/10.4271/2009-01-2309 https://doi.org/10.4271/2009-01-2309 https://doi.org/10.4271/2009-01-2309 https://doi.org/10.4271/2005-01-2706 https://doi.org/10.4271/2005-01-2706 https://doi.org/10.4271/2005-01-2706 https://doi.org/10.4271/2005-01-2706 https://doi.org/10.4271/2007-01-2493 https://doi.org/10.4271/2007-01-2493 https://doi.org/10.4271/2007-01-2493 https://doi.org/10.11183/jhe.43.1_9 https://doi.org/10.11183/jhe.43.1_9 https://doi.org/10.11183/jhe.43.1_9 https://doi.org/10.11183/jhe.43.1_9 https://doi.org/10.11183/jhe.43.2_79 https://doi.org/10.11183/jhe.43.2_79 https://doi.org/10.11183/jhe.43.2_79 https://doi.org/10.11183/jhe.43.2_79 https://doi.org/10.1063/1.4968390 https://doi.org/10.1063/1.4968390 https://doi.org/10.1063/1.4968390 https://doi.org/10.1063/1.4968390 https://pureportal.coventry.ac.uk/en/publications/visualisation-of-dance-performance-using-3-dimensional-motion-tra-3 https://pureportal.coventry.ac.uk/en/publications/visualisation-of-dance-performance-using-3-dimensional-motion-tra-3 https://pureportal.coventry.ac.uk/en/publications/visualisation-of-dance-performance-using-3-dimensional-motion-tra-3 https://pureportal.coventry.ac.uk/en/publications/visualisation-of-dance-performance-using-3-dimensional-motion-tra-3 https://doi.org/10.1007/s00221-015-4424-4 https://doi.org/10.1007/s00221-015-4424-4 https://doi.org/10.1007/s00221-015-4424-4 http://ijtte.com/uploads/2012-06-18/5ebd8640-2e18-c3f6ijtte%20vol%202%20no%202%20(2).pdf http://ijtte.com/uploads/2012-06-18/5ebd8640-2e18-c3f6ijtte%20vol%202%20no%202%20(2).pdf http://ijtte.com/uploads/2012-06-18/5ebd8640-2e18-c3f6ijtte%20vol%202%20no%202%20(2).pdf http://ijtte.com/uploads/2012-06-18/5ebd8640-2e18-c3f6ijtte%20vol%202%20no%202%20(2).pdf http://www.ingentaconnect.com/contentone/jmrp/jdms/2010/00000014/00000001/art00002 http://www.ingentaconnect.com/contentone/jmrp/jdms/2010/00000014/00000001/art00002 http://www.ingentaconnect.com/contentone/jmrp/jdms/2010/00000014/00000001/art00002 http://www.ingentaconnect.com/contentone/jmrp/jdms/2010/00000014/00000001/art00002 http://www.ingentaconnect.com/contentone/jmrp/jdms/2012/00000016/00000001/art00006 http://www.ingentaconnect.com/contentone/jmrp/jdms/2012/00000016/00000001/art00006 http://www.ingentaconnect.com/contentone/jmrp/jdms/2012/00000016/00000001/art00006 http://www.asbweb.org/conferences/2013/abstracts/6.pdf http://www.asbweb.org/conferences/2013/abstracts/6.pdf http://www.asbweb.org/conferences/2013/abstracts/6.pdf http://www.asbweb.org/conferences/2013/abstracts/6.pdf http://www.asbweb.org/conferences/2013/abstracts/6.pdf http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri https://doi.org/10.2340/16501977-2034 https://doi.org/10.2340/16501977-2034 https://doi.org/10.2340/16501977-2034 https://doi.org/10.2340/16501977-2034 http://www.painphysicianjournal.com/current/pdf?article=mji4ma%3d%3d&journal=87 http://www.painphysicianjournal.com/current/pdf?article=mji4ma%3d%3d&journal=87 http://www.painphysicianjournal.com/current/pdf?article=mji4ma%3d%3d&journal=87 https://doi.org/10.1016/j.jelekin.2016.06.003 https://doi.org/10.1016/j.jelekin.2016.06.003 https://doi.org/10.1016/j.jelekin.2016.06.003 https://doi.org/10.1016/j.gaitpost.2015.02.007 https://doi.org/10.1016/j.gaitpost.2015.02.007 https://doi.org/10.1016/j.gaitpost.2015.02.007 https://doi.org/10.1016/j.gaitpost.2015.02.007 http://opac.ll.chiba-u.jp/da/curator/900119151/tla_0192.pdf http://opac.ll.chiba-u.jp/da/curator/900119151/tla_0192.pdf https://doi.org/10.1113/jphysiol.2014.275438 https://doi.org/10.1113/jphysiol.2014.275438 https://doi.org/10.1113/jphysiol.2014.275438 https://doi.org/10.1113/jphysiol.2014.275438 https://doi.org/10.1523/jneurosci.4674-13.2014 https://doi.org/10.1523/jneurosci.4674-13.2014 https://doi.org/10.1523/jneurosci.4674-13.2014 https://doi.org/10.1007/s10237-015-0656-2 https://doi.org/10.1007/s10237-015-0656-2 https://doi.org/10.1007/s10237-015-0656-2 https://doi.org/10.1007/s10237-015-0656-2 https://doi.org/10.1016/j.clinbiomech.2013.12.009 https://doi.org/10.1016/j.clinbiomech.2013.12.009 https://doi.org/10.1016/j.clinbiomech.2013.12.009 https://doi.org/10.1063/1.4968328 https://doi.org/10.1063/1.4968328 https://doi.org/10.1063/1.4968328 https://doi.org/10.1063/1.4968328 mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.40-49 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study latif rozaqi a, *, estiko rijanto a, stratis kanarachos b a research center for electrical power and mechatronics, indonesian institute of sciences (lipi) kampus lipi, jalan sangkuriang, gd.20, bandung 40135, indonesia b centre for mobility & transport, coventry university priory street, coventry, cv1 5fb, united kingdom received 22 march 2017; received in revised form 31 may 2017; accepted 03 july 2017 published online 31 july 2017 abstract this paper proposes a new method of concurrent soc and soh estimation using a combination of recursive least square (rls) algorithm and particle swarm optimization (pso). the rls algorithm is equipped with multiple fixed forgetting factors (mfff) which are optimized by pso. the performance of the hybrid rls-pso is compared with the similar rls which is optimized by single objective genetic algorithms (soga) as well as multi-objectives genetic algorithm (moga). open circuit voltage (ocv) is treated as a parameter to be estimated at the same time with internal resistance. urban dynamometer driving schedule (udds) is used as the input data. simulation results show that the hybrid rls-pso algorithm provides little better performance than the hybrid rls-soga algorithm in terms of mean square error (mse) and a number of iteration. on the other hand, moga provides pareto front containing optimum solutions where a specific solution can be selected to have ocv mse performance as good as pso. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: li-ion; battery; state of charge (soc); state of health (soh); recursive least square (rls); particle swarm optimization (pso); genetic algorithm (ga) i. introduction battery states of charge (soc) and state of health (soh) have to be estimated properly in order to build a good battery management system (bms) for electric vehicles. it is known that lithium battery has time varying nonlinear dynamics where the speed of parameter values change is different on each parameter. there have been many soc estimation methods proposed by other researchers. a mixed coulombcounting and model-based algorithm was proposed for soc estimation of lifepo4 battery [1, 2, 3]. current and terminal voltages are measured, and an integral feedback controller is used to compensate terminal voltage and soc estimation errors. a pi observer was proposed for soc estimation of li-ion battery where the soc and polarization voltage are used as state variables [4]. more robust and advanced methods such as kalman filter [5, 6] and sliding mode observer [7] have also been used. however, the above methods assumed that the battery parameter values are constant or constant at some specified region, and treated the parameter values variance as a disturbance. a deeper investigation is required to evaluate the stability and estimation performance when the parameter values vary largely. recursive least square (rls) has also been applied for battery soc estimation. it was applied to a single rc thevenin model of lithium-ion battery whose open circuit voltage (ocv) was depicted by nernst equation [8]. it was applied to a double polarization rc thevenin model of a lifepo4 battery of which the soc is estimated by online identification of ocv and the predetermined ocv-soc look up table [9]. moving window least square (mwls) method was developed and applied to single rc * corresponding author. tel: +62 22 250 3055 e-mail address: latiefrozaqie@gmail.com https://dx.doi.org/10.14203/j.mev.2017.v8.40-49 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.40-49 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.40-49&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 41 thevenin models of li-ion and li-polymer batteries [10]. the soc and battery parameters are coestimated using a combination of mwls and linear observer. all the above rls based soc estimation methods use single forgetting factor. rls with multiple fixed forgetting factors (mfff) has been used to estimate soc of a li-ion battery. the forgetting factors were optimized using genetic algorithm (ga), and it was proved that the algorithm provided better performance than rls with single forgetting factor [11]. an interesting result has been reported on the estimation of battery soh using rls without forgetting factor. estimation speed and reliability have been compared between internal ohmic resistance based estimation and capacity based estimation. it can be concluded that soh estimation based on internal resistance is faster and more reliable [12]. many researchers have used pso algorithm for estimating battery soc in different ways. support vector regression (svr) was used to estimate soc of a lead-acid battery in which hyperparameters of the svr are determined using pso [13]. a hybrid model which combined multivariate adaptive regression splines (mars) and pso was used to estimate soc of a lifemnpo4 battery cell. pso was used to find the optimal parameters of the mars model. as a result, soc is represented by 29 pairs of basis functions and their coefficients [14]. stepwise method considering multicollinearity was used to predict battery soc. pso was used to find optimum coefficient values, and the soc can be expressed using 9 variables [15]. some methods for concurrent estimation of battery soc and soh have been proposed. dual kalman filter (dkf) was used for adaptive state and parameter estimation of lithium-ion batteries. diffusion voltage, state of charge, and internal resistance are selected as state variables, while cell capacity, diffusion resistance, and diffusion capacitance are chosen as parameters. one kalman filter is used for state estimation and the other kalman filter is used for parameter values [16]. a hybrid battery model was proposed which consists of an enhanced coulomb counting algorithm and an electrical circuit model. the coulomb counting algorithm is used for soc estimation while the electrical circuit model is used for electrical impedance estimation. five parameters are used in the electrical model those are internal resistance, one pair of resistance and capacitance which governs shortterm dynamics, and one pair of resistance and capacitance which governs long-term dynamics. a set of nonlinear discrete time dynamic equations are formulated using battery terminal voltage and current as measured signals as well as six unknown parameters. the unknown parameters include internal resistance, open circuit voltage, two parameters as a function of short-term dynamical resistance and capacitance, and two parameters as a function of longterm dynamical resistance and capacitance. pso is used to find a set of values of the unknown parameters which minimizes the selected fitness function. the ocv is then used for soc estimation using the enhanced coulomb counting method [17]. the dkf involves extended kalman filter for parameter identification which adds computational burden. the use of pso in the hybrid model requires execution of the pso iteration independently to the soc calculation routine which may rise a problem since there is no guarantee that the stopping criterion is fulfilled in the sampling period of soc calculation. an adaptive algorithm which can estimate soc and soh concurrently and can work under single sampling time and less computing burden is necessary. in this paper, such requirement is answered by proposing a new algorithm named hybrid recursive least square – particle swarm optimization (rlspso). rls is equipped with multiple fixed forgetting factors whose the values are tuned by pso. pso is simple and inexpensive computational effort compared to other artificial intelligence (ai) methods. the pso is used to find the optimum values of these forgetting factors in an offline manner using ai to avoid the tedious effort instead of trial and error. once optimum forgetting factor λ is obtained, the rls will run online with these determined optimum forgetting factor. soc is predicted based on open circuit voltage (ocv) while soh is predicted based on internal resistance. moreover, in order to evaluate the performance of hybrid rls-pso, a hybrid rls-ga (single objective ga (soga)) which is a more common method and had already used by the author on previous paper is employed [11]. furthermore, hybrid rls with multi-objectives ga (moga) is also introduced. in section ii, battery dynamical model, rls, and problem formulation described. section iii presents optimization methods to calculate values of forgetting factors using pso, soga, and moga. simulation results and discussion are reported in section iv. finally, conclusion is drawn in section v. ii. modeling and problem formulation figure 1 shows an equivalent circuit model using single rc [3]. 𝑉𝑡 and 𝐼 represent the battery terminal voltage and current, respectively. 𝑅0 is the battery internal resistance, 𝑅𝑝 is diffusion resistance, and 𝐶𝑝 is diffusion capacitance. 𝑈𝑑 denotes the voltage drop in the diffusion resistance. by using a convention that the current is positive when it flows into the battery, the dynamics of the battery model can be expressed in the following discrete time equations. 𝑈𝑑(𝑘) = −𝑎1𝑈𝑑(𝑘 − 1) + 𝑏0𝐼(𝑘) + 𝑏1𝐼(𝑘 − 1) (1) 𝑉𝑡(𝑘) = 𝑈𝑑(𝑘) + 𝑂𝐶𝑉(𝑘) (2) where: 𝑅0 = 𝑏0; 𝑅𝑝 = ( 𝑏1−𝑎1𝑏0 1+𝑎1 ); 𝐶𝑝 = ( 𝑇 𝑏1−𝑎1𝑏0 ) l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 42 terminal voltage and current are measurable, but 𝑈𝑑(𝑘) and 𝑂𝐶𝑉(𝑘) can not be measured in real time manner. ocv of the battery is known to be a nonlinear function of its soc [8]. the internal battery parameters are dependent on soc and they are time varying in nature. terminal voltage estimate �̂�𝑡(𝑘) can be expressed in the following linear equation. �̂�𝑘 = �̂�𝑡(𝑘) = �̂�𝑘 𝑇𝑥𝑘 (3) where the regressor 𝑥𝑘 and the parameter estimates �̂�𝑘 are given below. 𝑥𝑘 = [𝑈𝑑(𝑘 − 1);𝐼(𝑘); 𝐼(𝑘 − 1); 1] 𝜃𝑘 = [−𝑎1(𝑘); 𝑏0(𝑘); 𝑏1(𝑘); 𝑂𝐶𝑉(𝑘)] the measured terminal voltage is assumed to follow the following formula. 𝑦𝑘 = 𝑉𝑡(𝑘) = �̂�𝑡(𝑘) + 𝑒𝑘 (4) the parameter estimates are calculated using rls with multiple fixed forgetting factors (mfff-rls) as follows [18, 19]. 𝑒𝑘 = 𝑦𝑘 − 𝑥𝑘 𝑇 �̂�𝑘−1 (5) kik = pik−1 xik λi+xik t pik−1 xik (6) pik = (1 − kikxik t )pik−1 (7) lk = 1 1+ p1k−1 x1k−1 2 λ1 +⋯+ pik−1 x ik−1 2 λi [ p1k−1 x1k−1 λ1 ⋮ pik−1 xik−1 λi ] (8) θ̂k = θ̂k−1 + lkek (9) where subscript 𝑖 indicates the scalar components 𝑖 = 1,2 . . .𝑛. for the battery model addressed in this paper 𝑛 = 4. 𝜆𝑖 denotes forgetting factor. by assuming that ocv changes faster than the internal parameters, it is reasonable to select different values of forgetting factors among them. a computer script code (m file in matlab®) has been built to realize the mfff-rls algorithm according to the above description and formulae. the following performance index is used to evaluate the mfff-rls algorithm. 𝐽0 = 1 𝑁𝑠 ∑ {𝑉𝑡(𝑘) − �̂�𝑡(𝑘)} 2𝑁𝑠 𝑘=1 (10) soc estimation is optimized using performance index 𝐽1 , while soh estimation is optimized by performance index 𝐽2 as follows. 𝐽1 = 1 𝑁𝑠 ∑ (𝑂𝐶𝑉∗(𝑘) − 𝑂𝐶𝑉(𝑘))2 𝑁𝑠 𝑘=1 (11) 𝐽2 = 1 𝑁𝑠 ∑ (𝑅0 ∗(𝑘) − 𝑅0(𝑘)) 2𝑁𝑠 𝑘=1 (12) 𝑂𝐶𝑉∗ and 𝑅0 ∗ represent true values of ocv and internal resistance, respectively. the problem of determining optimum forgetting factor values is formulated as follows. 𝑀𝑖𝑛𝑖𝑚𝑖𝑧𝑒: 𝐽1(𝜆𝑖) 𝑀𝑖𝑛𝑖𝑚𝑖𝑧𝑒: 𝐽2(𝜆𝑖) 𝑊ℎ𝑒𝑟𝑒: 0 < 𝜆𝑖 < 1 𝐼(𝑘) 𝑖𝑠 𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑒𝑑 𝑏𝑦 𝑈𝐷𝐷𝑆 } (13) iii. optimization methods using pso and ga the optimization problem is solved using particle swarm optimization (pso) and genetic algorithm (ga). figure 2 shows the block diagram of the optimization method proposed in this paper. three methods are elaborated i.e. optimization based on pso (method 1), optimization based on soga (method 2), and optimization based on moga (method 3). their results are analyzed and compared. pso is a kind of evolutionary computation techniques which resembles the social behaviour of fish schooling or bird flocking. its basic conceptual framework was originally proposed in 1995 for optimization of continuous nonlinear functions [20]. the term swarm was selected because it articulated well five basic principles of swarm intelligence in artificial life, those are the proximity principle, the quality principle, the principle of diverse response, the principle of stability, and the principle of adaptability. it involves cooperation and competition among individuals throughout generations. each individual remembers the best position which had found, and the information of the global best position that an individual had found was shared to all members. since then it has been experiencing various developments [21, 22]. in pso, a particle represents a solution, and a swarm of particles is referred to as population of solutions. each particle is characterized by its velocity and position. every time a new position is achieved the best positions and velocities are updated. each particle adjusts its velocity based on its experiences. the following equations are used in pso to find optimum values of forgetting factors. 𝜆0 𝑖 = 𝜆𝑚𝑖𝑛 + 𝑅𝑎𝑛𝑑(𝜆𝑚𝑎𝑥 − 𝜆𝑚𝑖𝑛) (14) 𝑣0 𝑖 = 𝜆0 𝑖 𝑡𝑠 (15) 𝑣𝑘+1 𝑖 = 𝑤𝑣𝑘 𝑖 + 𝑐1𝑅𝑎𝑛𝑑 ( 𝑝𝑖−𝜆𝑘 𝑖 𝑡𝑠 ) + 𝑐2𝑅𝑎𝑛𝑑( 𝑝 𝑘 𝑔 −𝜆𝑘 𝑖 𝑡𝑠 )(16) 𝜆𝑘+1 𝑖 = 𝜆𝑘 𝑖 + 𝑣𝑘+1 𝑖 𝑡𝑠 (17) figure 1. single rc equivalent circuit model l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 43 𝜆𝑘 𝑖 and 𝑣𝑘 𝑖 represent the ith particle at time k of the positions and velocities, respectively. the upper and lower bounds on the positions are denoted by 𝜆𝑚𝑎𝑥 and 𝜆𝑚𝑖𝑛 . rand is a uniformly distributed random variable whose value is between 0 and 1. 𝑡𝑠 denotes a positive scalar. the initial positions 𝜆0 𝑖 and initial velocities 𝑣0 𝑖 are randomly generated by equation (14) and (15). for the next iteration, velocities of each particle is given by equation (16). 𝑝𝑖 is the best positions of each particle over time in current and all previous moves. 𝑝𝑘 𝑔 is the best global positions of a certain particle in the current swarm with respect to a predefined fitness function. the new search direction incorporates three pieces of information which have each own weight factor. the first part is current motion which is multiplied by its inertia factor 𝑤. the second part is particle memory influence which is multiplied by its cognitive factor 𝑐1, and the third part is swarmed influence which is multiplied by its social factor 𝑐2. position update of each particle is given by equation (17). in order to minimize mean square error values of open circuit voltage and internal resistance, the following fitness function is used. ft = αf1 + (1 − α)f2 (18) where f1 = 1 ns ∑ (1 − ocv(k) ocv∗(k) ) 2 ns k=1 (19) f2 = 1 ns ∑ (1 − r0(k) r0 ∗(k) ) 2 ns k=1 (20) 0 < α < 1 (21) by normalizing performance indexes in equation (11) and (12), their corresponding dimensionless fitness functions are obtained in equation (19) and (20). the total fitness function in equation (18) is a sum of the weighted normalized fitness functions. values of the weight 𝛼 are listed in table 1. genetic algorithm (ga) is an evolutionary algorithm which imitates evolution of living creature. many variants of gas exists depending on evaluation method of new chromosomes, a calculation method using serial or parallel processors, combination with some local optimization algorithms (hill climbing, etc), and other factors [23]. a computer code script (m file in matlab®) has been built to realize a ga according to the following procedure: first, define parameter values including number of initial population/chromosomes 𝑁𝑖𝑝 , number of genes in a chromosome is 4, boundary value of each gene (0 < 𝜆𝑖 < 1 ), and number of bits for each genotype to construct phenotype 𝑁𝑏.second, define probability rate values including selection probability rate 𝑃𝑠, crossover probability rate 𝑃𝑐, and mutation probability rate 𝑃𝑚. each probability rate is divided into three sets which are generated randomly, namely small (random value from 0.1 to 0.3), medium (random value from 0.4 to 0.6), and large (random value from 0.7 to 0.9). thus, there exist 27 sets of probability rate values which yield 27 best chromosomes from 27 different evolutions. third, create initial random chromosomes. fourth, evaluate fitness of each chromosome using fitness function in equation (18), and select best individuals using ranking method. fifth, create mating pool and generate offsprings by applying a single point crossover. sixth, reproduce and ignore few chromosomes. seventh, performs mutation by bit flipping operation randomly according to the mutation probability rate. elitism principle is used to control mutation. finally, back to step 4, until termination criterion is achieved. method 1 and method 2 above are used to solve the single objective function in equation (18). in order to solve the original multiple objectives optimization problem described in the problem formulation at the previous section, multiple objectives ga (moga) is also implemented. a fast elitist multiobjective ga known as nondominated sorting genetic algorithm ii (nsgaii) is used to solve this problem since this algorithm has three advantages, i.e. a fast nondominated sorting procedure, a fast crowded distance estimation process, and a simple crowded comparison operator. the main loop of the nsga ii procedure is described below [24]. first, combine parent and offspring population and saved as 𝑅𝑡. second, execute the fast non-dominated sorting procedure against 𝑅𝑡, and save the result of all non-dominated fronts of 𝑅𝑡 into 𝐹 = (𝐹1,𝐹2,⋯). third, set initial values of parent population 𝑃𝑡+1 = 0 , and generation counter 𝑖 = 1 . fourth, run iteration of generation until the parent population is filled and |𝑃𝑡+1| + |𝐹𝑖| ≤ 𝑁. execute the crowded distance estimator in 𝐹𝑖 , include i-th nondominated front in the parent population, then check the next front for inclusion 𝑖 = 𝑖 + 1. fifth, sort 𝐹𝑖 in figure 2. the optimization method of forgetting factors values table 1. weight of finess function no 1 2 3 4 5 6 7 8 9 α 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 44 descending order using the crowded comparison operator. sixth, choose the first (𝑁 − |𝑃𝑡+1|) elements of 𝐹𝑖 and include them into the parent population. seventh, use selection, crossover, and mutation to create offspring 𝑄𝑡+1 . finally, increment the generation counter 𝑡 = 𝑡 + 1. more details about the algorithm can be seen in [24]. iv. results and discussion in order to validate the proposed method, computer simulation has been conducted. the swarm size in pso and initial population in ga is set to 64. the population size is chosen based on the crossover operation in ga, it is easier to choose a 2n number. larger n needs more calculation time each iteration but yields smaller number of generation. based on this consideration we choose n=6. for the sake of equality and comparability, the swarm size in pso is chosen the same number. the optimization is executed iteratively until a termination criterion is achieved. fitness function tolerance is set to 10e-6 while stall iteration is set to 50. for method 1, the cognitive factor and social factor are set 𝑐1 = 1.49 and 𝑐2 = 1.49. in order to maintain the speed of convergence while avoiding local optima, the inertia factor is changed linearly with iteration counter 𝑘 as follows. 𝑤 = 𝑤𝑖 − (𝑤𝑖−𝑤𝑓) 𝑁 𝑘 (22) in this simulation, parameter values related to inertia factors are set as follows: 𝑤𝑖 = 1.1, 𝑤𝑓 = 0.1, and 𝑁 = 50. figure 3 shows trajectories of fitness function 𝐹𝑡 as a function of generation for 9 different weight values in table 1. figure 3(a) plots the results of method 1 while figure 3(b) those of method 2. in method 2, every single weight produces 27 sets of solutions according to the values of selection, crossover, and (a) (b) figure 3. trajectories of fitness function 𝐹𝑡; (a) pso; (b) soga l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 45 mutation probability rates. the best solution is selected among 27 choices. therefore, in figure 3(b) we have 9 curves of the best-selected solutions. it is obvious that the value of weight affects the fitness function value significantly. the best result of method 1 and method 2 in figure 3 are plotted together in figure 4. from figure 4, some important results can be summarized as follows: first, the soga and pso provide similar performance index values at the end of generation (after 52 iterations). second, at the 3rd and 4th generation, soga provides better performance than pso. third, the 5th generation, soga and pso provide similar performance. fourth, at the 6th generation, pso gives better performance than soga, and this condition remains until the 43rd generation. during this condition, the performance difference is around 10-8 this implies that pso provides better performance than soga in terms of less generation number. depending on the engineering problem solved, a performance difference of 10-8 may be considered as substantially small, so that one may argue that soga and pso have the same capability for solving optimization problem such as this paper. however, in this paper, the cognitive and social factor values of pso are fixed. investigation of the impact of different cognitive and social factor on the performance is left for further study. figure 5 shows the pareto front obtained by nsga ii. from this result, it can be seen that nsga ii provides several optimal solutions of the original multi-objectives optimization problem stated in equation (13). in other words, this implies that nsga ii leaves the final decision to us to select a solution. in this paper, a solution is selected which gives the similar performance of fitness functions 𝐹1 and 𝐹2 from pso and soga above. thus, 𝐹1 = 1.5733𝑒 − 6 and 𝐹2 = 1.3829𝑒 − 6. in respect to the time consumed or a number of generation during iteration, the following results are obtained: first, pso requires a smaller number of generation to yields better mse performance than soga. second, moga requires much longer time than pso and soga because it computes pareto front containing several numbers of optimum solutions. table 2 lists up the forgetting factors obtained by pso, soga, and nsga ii. these forgetting factors are used together with mfff-rls to estimate battery terminal voltage, ocv, soc, and internal resistance 𝑅0. figure 6 shows battery terminal voltage and its estimation error during the udds testing using the forgetting factors in table 2. red line is the results of pso, the blue line is the results of soga, and the green line is the results of nsga ii. figure 7 shows the corresponding ocv while figure 8 shows the corresponding soc and its estimation error. figure 9 shows time history of internal resistance estimate �̂�0(𝑘) and its error 𝑒�̂�0(𝑘) = 𝑅0(𝑘) − �̂�0(𝑘). table 3 lists performance index values obtained from these results. as expected pso, soga and nsga ii give similar performances in terms of mean square error. however, pso and moga provide a little better performance than soga in terms of ocv mse value. figure 4. the best performance index 𝐹𝑡 of pso and soga table 2. forgetting factors obtained through optimization method 𝝀𝟏 𝝀𝟐 𝝀𝟑 𝝀𝟒 pso 0.9298 0.0101 0.7171 0.2316 soga 0.9395 0.0508 0.7489 0.2692 nsga ii 0.9365 0.9185 0.8148 0.3062 table 3. performance index value no performance index values pso soga nsgaii 1 𝐽0 2.0574e-08 2.1339e-08 2.2961e-08 2 𝐽1 2.4773e-05 2.4912e-05 2.4339e-05 3 𝐽2 1.1559e-11 1.1559e-11 4.1533e-10 l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 46 figure 5. pareto front of nsga ii (a) (b) figure 6. tracking performance of various methods; (a) terminal voltage; (b) estimation error l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 47 figure 7. open circuit voltage (a) (b) figure 8. tracking performance of various methods; (a) time history of state of charge; (b) soc error l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 48 v. conclusions from the computer simulation results, the following conclusion can be drawn. by selecting proper probability rates of selection, crossover, and mutation, soga was able to produce almost similar performance with pso in terms of mse. considering the number of generation, pso provides better performance than soga in terms of less generation number. moga provides pareto fronts containing optimum solutions where a specific solution can be selected to have mse performance as good as pso. however, the moga requires much longer time than pso and soga because it computes pareto fronts containing several numbers of optimum solutions. acknowledgement the authors thank to the indonesian institute of sciences (lipi) for providing financial support in the scheme of excellent research programme with the contract number 1975.3/d3/pg/2016 of the financial year of 2016. they also deliver gratitude to the ministry of science, technology, and higher education of the republic of indonesia in providing financial support for conducting individualized immersion programme at centre for mobility & transport, coventry university, united kingdom in 2016. references [1] f. codeca et al., "on battery state of charge estimation: a new mixed algorithm," in proc. ieee int. conf. control appl., pp.102-107, 2008. [2] f. codeca et al., "the mix estimation algorithm for battery state-of-charge estimator – analysis of the sensitivity to measurement errors," pp.8083-8088, 2009. [3] a. nugroho et al., "battery state of charge estimation by using a combination of coulomb counting and dynamic model with adjusted gain," in international conference on sustainable energy engineering and application (icseea), pp.54-58, 2015. [4] j. xu et al., "the state of charge estimation of lithium-ion batteries based on a proportional-integral observer," ieee trans. veh. technol., vol. 63, no. 4, pp. 1614-1621, 2014. [5] r. xiong et al., "a robust state-of-charge estimator for multiple types of lithium-ion batteries using adaptive extended kalman filter," j. power sources, vol. 243, pp. 805-816, 2013. [6] d. li et al., "state of charge estimation for limn2o4 power battery based on strong tracking sigma point kalman filter," j. power sources, vol. 279, pp. 439-449, 2015. [7] x. chen et al., "a novel approach for state of charge estimation based on adaptive switching gain sliding mode observer in electric vehicles," j. power sources, vol. 246, p. 667–678, 2014. [8] x. hu et al., "online estimation of an electric vehicle lithium-ion battery using recursive least squares with forgetting," 2011. [9] h. he et al., "online model-based estimation of state-ofcharge and open-circuit voltage of lithium-ion batteries in electric vehicles," energy, vol. 39, no. 1, p. 310–318, 2012. [10] h. r. eichi and m. chow, "adaptive parameter identification and state-of-charge estimation of lithium-ion batteries," (a) (b) figure 9. tracking performance of various methods (a) internal resistance; (b) error in internal resistance l. rozaqi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 40–49 49 iecon 2012 38th annual conference on ieee industrial electronics society, pp. 4012-4017, 2012. [11] l. rozaqie and e. rijanto, "soc estimation for li-ion battery using optimum rls method based on genetic algorithm, "proc. international conference on information technology, electrical engineering, date of conference oct, 2016. added to ieee xplore 28 february 2017. [12] m. n. ramadan et al., "comparative study between internal ohmic resistance and capacity for battery state of health estimation," journal of mechatronics, electrical power, and vehicular technology, vol. 6, no. 2, pp. 113-122, 2015. [13] v. surendar et al., "estimation of state of charge of a lead acid battery using support vector regression," procedia technology 21, pp. 264-270, 2015. [14] j. c. anton et al., "a new predictive model for the state of charge of a high power lithium-ion cell based on a pso optimized multivariate adaptive regression splines approach," ieee transactions on vehicular technology , 2015. [15] b. wahono et al., "prediction model of battery state of charge and control parameter optimization for electric vehicle," journal of mechatronics, electrical power, and vehicular technology, vol. 6, no. 1, pp. 31-38, 2015. [16] g. walder et al., "adaptive state and parameter estimation of lithium-ion batteries based on a dual linear kalman filter," proceeding of second international conference on the society of diital information and wireless communications (sdiwc), , 2014. [17] t. kim et al., "online state of charge and electrical impidance estimation for multicell lithium-ion batteries," ieee transportation electrification conference and expo (itec), pp. 1-6, 2013. [18] a. vahidi et al., "simultaneous mass and time-varying grade estimation for heavy-duty vehicles," proc. 2003 american control conference, vol. 6, p. 4951–4956, 2003. [19] a. vahidi, et al., "recursive least squares with forgetting for online estimation of vehicle mass and road grade: theory and experiments," veh. syst. dyn., vol. 43, no. 1, pp. 31-55, 2005. [20] j. kennedy and r. eberhart, "particle swarm optimization," proceedings of the ieee international conference on neural ntworks, pp. 1942-1945, 1995. [21] j. yisu et al., "the landscape adaptive particle swarm optimizer," applied soft computing, vol. 8, pp. 295-304, 2008. [22] a. sahu et al., "fast convergence particle swarm optimization for functions optimization," procedia technology, vol. 4, pp. 319-324, 2012. [23] a. munawar et al., "a survey: genetic algorithms and the fast evolving world of parallel computing," in proc. 10th ieee int. conf. high perform. comput. commun. hpcc 2008, pp. 897–902, 2008. [24] k. deb et al., "a fast and elitist multiobjective genetic algorithm: nsga ii," ieee transactions on evolutionay computation, vol. 6, no. 2, pp. 182-197, 2002. mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2018.v9.17-24 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. condition assessment of power transformers status based on moisture level using fuzzy logic techniques vezir rexhepi *, petar nakov technical university of sofia, faculty of electrical engineering, boulevard “sveti kliment ohridski”, 8, 1000, sofia, bulgaria received 19 february 2018; received in revised form 27 april 2018; accepted 2 may 2018 published online 31 july 2018 abstract power transformers are one of the most expensive components; therefore the focus on their status and its continuous operation is the primary task. in the power systems, condition assessment of performance and reliability is based on the state of components, measurements, testing, and maintenance as well as their diagnosis. hence, condition assessment of power transformer parameters is important regarding their status and finding incipient failures. among many factors, the most factors that affect the safe operation and life expectancy of the transformer is the moisture in oil. it is known that the low moisture oil in power transformers causes many problems including electrical breakdown, increase the amount of partial discharge, decreases the dielectric withstand strength and other phenomena. thus, knowledge about the moisture concentration in a power transformer is significantly important for safe operation and lifespan. in this study, moisture level in oil is estimated, and its status classification is proposed by using fuzzy logic techniques for the power transformer monitoring and condition assessment. moreover, the goal of the study is to find methods and techniques for the condition assessment of power transformers status based on the state of moisture in oil using the fuzzy logic technique. these applied techniques increase the power system reliability, help to reduce incipient failures and give the better maintenance plan using an algorithm based on logic rules. also, by using the fuzzy logic techniques, it is easier to prevent failures which may have consequences not only for transformers but also for the power system as a whole. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: moisture in oil; power transformers; fuzzy logic techniques; failures; condition assessment; measurements. i. introduction power transformers are key components for transmission and distribution infrastructure that transfer electricity from the substations to consumers. forced component outages caused by failures may collapse the electrical power systems, interrupt the electricity consumption and give an environmental impact. the transformer could fail due to electrical failures, mechanical or thermal stresses. such defects are sometimes catastrophic and can be lead to an unscheduled outage of the component, therefore causing the need of repairment and replacement. assessment of power transformer condition is the basis for reliable operation and optimal repairs schedule. generally, there are four main aspects of transformer condition monitoring and assessment, includes thermal dynamics, dissolved gas, partial discharge, and winding deformation [1]. continuous monitoring of oil insulation characteristics has become an important task to avoid deterioration of its characteristics under working conditions. several efforts have been made over the past years to study the electrical, physical, and chemical of insulating oils [2]. methods for evaluating the status and monitoring of transformer parameters create a possibility of diagnosis and analysis to define accurate measures for necessary steps that should be taken into consideration. various methods have been explained [3], such as using fuzzy logic techniques or the neural network methods. the combination of these techniques will improve diagnostic decision-making under the uncertainty inherent in diagnostic information, and it can also capture gradual system degradation [4]. the techniques for condition assessment, measurement, * corresponding author, tel: +383 44 558 305 e-mail: vezir.rexhepi@gmail.com https://dx.doi.org/10.14203/j.mev.2018.v9.17-24 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.17-24 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.17-24&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ v. rexhepi and p. nakov. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 18 and interpretation of gases have been developed [5]. however the assessment technique should be extended to other parameters such as moisture concentration in oil. furthermore, through such techniques, a more detailed look at the predictions of failures based on the statistics for transformers is not needed. faults in different parts of transformer winding or other parts during impulse tests generate distinct signatures in the time-frequency spectrum. thus, such signs are difficult and impossible for the human eyes to identify; this complex task can be successfully handled and developed by modern classification algorithm such as fuzzy logic [6]. the main objective of this paper is to design a model or technique for condition assessment of the moisture in oil of the power transformers. the assessment of parameter conditions through fuzzy logic techniques also makes a significant contribution to the recognition of transformer status as well as its ranking according to the conditions and quality of parameters in the case of moisture in oil. the model includes the design of the algorithm, which the given inputs are the conditions of moisture in oil (five conditions), and oil level (defining oil by standards). those inputs are processed by logic rules if, and, then, to finally results in the condition assessment of the moisture in oil, monitoring measures, diagnosis, and preventive measures. the condition assessment through this logic is also compared with the statistical database. ii. failure analysis in a power system and assessment methods in a power system, unplanned outages, faults, and hidden failures are difficult to track down and to model because those are obviously hidden [7]. the reliability of the power system is classified into adequacy and security. the adequacy is related to the existence of sufficient generation of the electric power system to comply the consumer demand. meanwhile, the security is related to the ability of power system to respond to the transients and disturbances that occur in the system [8]. failure is an inability of a part or equipment to carry out its specified function. meanwhile, a fault has broader meaning than a failure in specific equipment and its related features that needed for proper operation of the equipment [9]. a power transformer condition monitoring focuses mainly on the detection of incipient faults inside the transformer that are generated from the gradual deterioration. some of these incipient faults may be detected during routine maintenance; however other faults may cause numerous problems before the regular maintenance cycle. markov method is a stochastic process in which future states are conditional only on the present state and independent of previous states [10]. the markov process in which there is the number of finite states 𝑆1, 𝑆2, 𝑆3, . . . , 𝑆𝑛 that may exist at any given time. the probability of the process moving from 𝑆𝑖 to 𝑆𝑗 is denoted by the transition probability 𝑃𝑖𝑗 and the probability of the process remaining in the same state is denoted by the probability -𝑃𝑖𝑖 [11]. markov method is widely used for reliability and simulation analysis [12]. a system is made of a number of components 𝑛, which at any given time may be operating successfully or not. the successful operation of the entire system depends on the operation or failure of its components. therefore, the system may exist in one of two states as follow: 1. an operating state, where the system is operating even if some of its components have failed. a fully operational system is one in which no components have failed. 2. a failed state, where the system is not operating because of the failure of one or more of its components [12][13]. previous researches have discussed the topic of condition assessment of transformers in several contexts. one method is fault identification at the defective condition, commissioning test, and trend analysis [14]. the power transformer monitoring process evaluation starts from the beginnings of incipient failures, their diagnosis, and the final actions of the measures to prevent the defects or failures are presented in figure 1. another method is a linear regression that consists of finding a linear function bxwxf  )()(  that gives the best interpolation of a set of training points labeled from y r . geometrically this corresponds to a hyperplane fitting of the given points. this technique is known as a method of least squares [15]. therefore, the training process of a neural network involves tune of the value of the weights and the biases of the networks to optimize network performance, as defined by the network performance function [16].      n i n i iit n ie n msef 1 1 2 )( 12 )( 1  (1) in the equation (1),  is network outputs, t target, and mse is the mean square error. by comparing the data in their input, and processing by combining the data, it is possible to obtain results that enable the recognition of the conditions of the transformer operation according to the parameters that had been taken into account [17]. in some condition, assessment methods can be confirmed or automated with the use of electronic performance support systems such as statistics based systems, expert systems, and algorithms [18]. iii. problem formulation using fuzzy logic probability and fuzziness are related to different concepts. fuzziness is a type of deterministic figure 1. process evaluation of power transformer monitoring symptoms diagnosis cure v. rexhepi and p. nakov / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 19 uncertainty. it describes the event class ambiguity, so fuzziness measures the degree in which an event occurs. a linguistic variable can be regarded as a variable of value, either a fuzzy number, or a variable. fuzzy logic of fuzzy set theory provides a basis for mathematical modeling and language to express quite sophisticated algorithms in a precise manner [19]. the fuzzy techniques consist of several phases and processes, which are analyzed according to the defined conditions in the assessment range. through the building concept of the model, inputs, and outputs; the database is processed according to the numerical values of the membership that are allocated to the respective sets. the output is obtained through the set of inputs rules. the implementation of the fuzzy logic technique to a real application requires the following three steps: a) fuzzification – convert classical data into fuzzy data or membership functions, b) fuzzy interference process – combine membership functions with the control rules to derive the fuzzy output, and c) defuzzification – use different methods to calculate each associated output to put them into a table or graphical structure [20]. the most popular fuzzy logic systems are mamdani and sugeno which use crisp data as inputs. as an extension of the mamdani model in order to work with interval inputs, the fuzzy sets are represented by triangular fuzzy numbers [21]. the processes and steps of operating conditions assessment and their status according to fuzzy logic are also included. determining the membership functions of inputs means that the data populations as well as the assessment of transformers parameters are inputted at certain time periods or on a continuous basis. the membership functions of the outputs are determined by members and their impact on the status of power transformers. for different cases involving aspects of issues evaluation that have an impact on specific parameters, such as temperature, state of gases, moisture in oil, paper, tap changer, hot spot partial discharge, and load factor. therefore, this structure of fuzzy logic operation is built by populating the data at certain time periods in the online or offline mode.                                       hx gxf fxe ex hgfejand xd dxc bxa ax dcbai 0 ),,,,0(, 0 ),,,,0( (2) in equation (2), the logic technique for defining the inputs and outputs parameters is depicted. this includes the membership determination by the levels and numbers belonging to the sets, which based on the respective measurements, and their comparison is made to reach the most accurate conclusions. structuring the rules of fuzzy logic includes a set of rules (range of data) that are created according to the classification of transformer occurrences. the entirety of the failures causes is processed according to the logic operators, if, and, then. through the processing of the causes, their ranking according to the assessment results is derived from the outputs. it constitutes a logical method of data processing and obtaining results that can be helpful in monitoring and diagnosis of transformers during continuous operation. in this study, a problem of condition estimation of the power transformers that are installed in the transmission system of kosovo is addressed. the transformers conditions are estimated based on moisture content in the oil using fuzzy logic. simulation results are compared with real measurements results, and a ranking of the power transformers conditions is presented. iv. condition assessment model of power transformer parameters condition assessment of electrical, thermal, and mechanical parameters is one of the fundamental elements for determining the operational continuity of transformers. fuzzy logic may be applied for condition assessment and status classification of the transformers which emphasize the main parameters such as oil temperature, winding temperature, dissolved gases, moisture in oil, and partial discharge. oil insulation is an important form of the power transformer insulation system. the remaining life of the transformer largely depends on the oil insulation status. aging degree and moisture content are two important factors of insulation state assessment. thus, accurate assessment technique to evaluate the condition of oil in the power transformers insulation has become a popular research topic. a lot of valuable research about oil insulation condition assessment and the influence of moisture have been done, such as; spectroscopy, polarization and depolarization current, and recovery voltage measurement [22]. this paper proposes a fuzzy model which involves two fuzzy input variables, i.e., moisture in oil and moisture level, and transformer condition status as the fuzzy output. the moisture in oil is divided into five functions: condition 1 (con1), condition 2 (con2), condition 3 (con3), condition 4 (con4), and condition 5 (con5). the moisture level is also divided into five functions: very low (vl), low (l), medium (m), high (h), and very high (vh). the transformer condition status is divided into six functions: very good (vg), good (g), medium (m), alarm 1 (a1), alarm 2 (a2), and alarm 3 (a3). figure 2 illustrates the proposed fuzzy model. the model includes an algorithm where the two fuzzy inputs are given and processed by logic rules (if, and, then) to produce a condition assessment. this fuzzy model links the two fuzzy input variables with a transformer condition status. this model provides a clear view of a transformer conditions status and necessary measurement according to the fuzzy output. figure 3 and figure 4 show the functions of the fuzzy input and output variables, respectively. v. rexhepi and p. nakov. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 20 moisture in oil moisture level rule 1 rule 2 rule 3 rule 4 rule 5 rule 11 condition assessment condition 1 condition 2 condition 3 condition 4 condition 5 very low low medium high very high very good good medium alarm 1 alarm 2 alarm 3 if moisture in oil is condition 1 and oil level is very low operation then condition assessment is very good rule 6 if moisture in oil is condition 1 and oil level is low operation then condition assessment is very good if moisture in oil is condition 2 and oil level is low operation then condition assessment is good if moisture in oil is condition 2 and oil level is medium operation then condition assessment is good if moisture in oil is condition 3 and oil level is medium operation then condition assessment is good if moisture in oil is condition 3 and oil level is medium operation then condition assessment is medium if moisture in oil is condition 5 and oil level is very high operation then condition assessment is alarm 3 figure 2. fuzzy logic model for condition assessment (a) (b) figure 3. the functions of fuzzy input variables; (a) moisture in oil; (b) moisture level v. rexhepi and p. nakov / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 21 according to oil moisture ranges in the standard of power transformer operation condition, the universe of discourse (uod) of fuzzy input variables is expressed in equations (3) and (4), whereas uod of fuzzy output variable is expressed in equation (5) [23].                         305 29204 20153 1562 601 econdtion dcondition ccondition bcondition acondition oilinmoisture (3)                         30 2920 2015 158 80 ehighvery dhigh cmedium blow alowvery levelmoisture (4)                          303 29252 25201 2015 158 80 ealarm ealarm dalarm cmedium bgood agoodvery assessmentcondition (5) this fuzzy rule refers to the standard regarding power transformer condition status [24]. eleven fuzzy rules are proposed in this study and listed in table 1. figure 5 and figure 6 illustrate 11 fuzzy rules that link each relevant fuzzy input variable with the corresponding fuzzy output variable using logic operators (if, and, then) in matlab®/simulink® environment. figure 7 shows three dimensional form of the parameter levels extension according to the level of moisture in oil, output to the z axis through measured samples, and data processing based on the rules of fuzzy logic. the standards or codes recommend the counter measures or actions to be done for each power transformer conditions status [25]. table 2 summarizes the appropriate measure according to the standards/codes. v. results and discussion monitoring and diagnosis of the status of transformers in the operator transmission system of kosovo were conducted from july to august 2017. the fuzzy logic model of transformer condition assessment includes 65 transformers from 20 up to 400 mva power capacity. the kelman transport x – mobile labs was used to measure moisture in oil and its level. measurement of moisture in oil and moisture level was conducted manually. manual diagnostics were conducted by mapping values of the manual measurements to the condition status according to the power transformer assessment code. simulated diagnostics were carried out by inputting the same values of measurement to the fuzzy logic model to obtain the corresponding transformer condition status. figure 8 presents the assessment results of the power transformers. transformer condition status is shown as figure 4. output and membership functions table 1. fuzzy rule base (11 fuzzy rules) condition status moisture in oil con 1 con 2 con 3 con 4 con 5 m o is tu re l e v e l vl vg l vg g m g g+m m h m+a1 a2 vh a3 table 2. recomended measures / actions according to standard status recommended action vg no need any action to make a diagnosis g no need any action to make a diagnosis m should be under monitoring from time to time a1 should be under continuous monitoring a2 need any action to make diagnosis and analysis a3 should be out of operation for deep analysis v. rexhepi and p. nakov. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 22 the result of manual diagnostics and simulated diagnostic using fuzzy logic. the same results are listed in table 3. the error is calculated by subtraction the manual diagnostic value from the corresponding fuzzy logic diagnostic value. from the error values, it can be calculated that the mean error is zero and the root mean squared error (rmse) is 1.62. explanation of the first raw in table 4 is as follows: 1st condition assessment; moisture in oil = 3 ppm; moisture level = 7 ppm; and condition assessment = 4.07 ppm. from the data, the result only emerges the 1st rule, where according to this rule, it can be concluded that if the moisture in oil is condition 1 and the moisture level is in very low operation then the condition assessment is very good, that means the transformers are in very good condition and do not need any diagnosis or analysis. other raws in table 4 have a similar explanation. discussion of the cases related to the status of the power transformers parameters such as moisture in oil is helpful in achieving results for defining the transformer status during their work. it is also table 3. condition assessment results status number of transformer error fuzzy logic diagnostic manual diagnostic vg 2 4 -2 g 55 53 2 m 7 5 2 a1 0 2 -2 a2 0 0 0 a3 1 1 0 total 65 65 0 figure 5. assessment model by the fuzzy logic method figure 6. definition of the structure rules v. rexhepi and p. nakov / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 23 important to perform other analysis. through the fuzzy logic model, condition assessment or diagnosis of the power transformers can be carried out automatically. measurements values of moisture in oil and moisture level are fed to the fuzzy logic model, and the transformer condition status is automatically obtained. vi. conclusion a fuzzy logic model for transformers condition assessment was designed based on moisture content. the fuzzy logic model was applied to 65 transformers condition assessment in order to classify them into 5 statuses, i.e. very good, good, medium, alarm 1, alarm 2, and alarm 3. the simulation result using the fuzzy logic model was compared with the manual assessment result based on the standard/code. the error between the simulation result and the manual assessment result was calculated. the mean value of error was zero, and the root means square error (rmse) was 1.62. these results demonstrated that the proposed fuzzy logic model had provided good assessment performance. it can be assumed that fuzzy logic technique constitutes an efficient method for understanding transformer status over the key parameters. it also reflects the connectivity between on-line measurements and time to time measurements in a function to achieve the most accurate and reliable results. table 4. examples of some diagnostics using fuzzy logic ca moisture in oil (ppm) moisture level (ppm) ca (ppm) effective rule status 1st 3 7 4.07 1 vg 2nd 16 18 14.0 5 g 3rd 20 19 17.2 5 m 4th 24 24 20.3 9 a2 5th 35 35 47.0 11 a3 figure 7. three-dimensional graphic of the moisture level in the oil figure 8. condition assessment monitoring of the moisture in oil to the power transformers 4 53 5 2 0 1 2 55 7 0 0 1 0 10 20 30 40 50 60 very good good medium alarm 1 alarm 2 alarm 3 c o n d it io n a ss e ss m e n t o f p o w e r tr a n sf o r m e r s power transformer numbers simulation by fuzzy logic measurements v. rexhepi and p. nakov. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 17–24 24 acknowledgement this work was supported by the kosovo transmission system kostt. references [1] jose luis martinez, “condition assessment of power transformers: a practical methodology approach”, 23rd international conference on electricity distribution, june 2015, cired, lyon, france. [2] nikolina petkova, petar nakov, valeri mladenov, “real time monitoring of incipient faults in power transformer”, electricity distribution, springer, pp. 221 – 240, berlin heidelberg, march 2016. isbn: 978-3-662-49434-9. [3] ioana făgarăşan, sorina costinas, sergiu st. iliescu, “monitoring and diagnosis methods for high voltage power transformers”, u.p.b. sci. bull. series c, vol. 70, no.3, 2008, romania. [4] lefeng cheng, tao yu, “dissolved gas analysis principlebased intelligent approaches to fault diagnosis and decision making for large oil-immersed power transformers: a survey”, energies, mdpi, april, 2018. [5] s. tenbohlen, j. aragon-patil, m. fischer, z.d. wang, m. schäfer, i höhlein atanasova, “investigation on sampling, measurements and interpretation of gas-in-oil analysis for power transformers”, 42nd international conference on large high voltage electric systems,2008, cigre, 2008. paris, france. [6] shweta taneja, bhawna suri, himanshu narwal, anchit jain, akshay kathura, sachin gupta, “a new approach for data classification using fuzzy logic”, cloud system and big data engineering (confluence), 2016th international conference, ieee, january 2016. [7] lili zhao, xueming li, ming ni, tianyu li, yameng cheng, “review and prospect of hidden failure: protection system and security and stability control system”, journal of modern power systems and clean energy, pp. 1 – 9, april, 2015. [8] j. p. deane, francesco gracceva, alessandro chiodi, maurizio gargiulo, brian p.o. gallachoir, “assessing power system security. a framework and a multi model approach”, international journal of electrical power & energy systems, volume 73, december 2015, pp. 283-297. [9] vezir rexhepi, “an analysis of power transformer outages and reliability monitoring”, 4th international conference on power and energy systems engineering, cpese, energy procedia, volume 141, september, 2017, pp. 418-422. [10] wimonmas bamrungsetthapong and adisak pongpullponsak, “parameter interval estimation of system reliability for repairable multistate series-parallel system with fuzzy data”, the scientific world journal, may, 2014. [11] charles m. grinstead, j. laurie snell, introduction to probability.. american mathematical society, usa, july, 1997, pp. 405 – 452. [12] m. srinivasa rao, v. n. a. naikan, “reliability analysis of repairable systems using system dynamics modeling and simulation”, journal of industrial engineering international, september, 2014, springer berlin heidelberg. [13] g. levetin, “computational intelligence in reliability engineering evolutionary techniques in reliability analysis and optimization”, springer-verlag berlin heidelberg, pp. 11-18, 2007. [14] jean sanchez, mladen banovic, “a general overview of power transformer diagnosis”, april, 2014, research gate. [15] guowei yang, jia xu, “a new fitting scattered data method based on the criterion of geometric distance”, 2nd aasri conference on computational intelligence and bioinformatics, vol 6, 2014, pp. 41-48. [16] ivan nunes da silva, danilo hernane spatti, rogerio andrade flauzino, luisa helena bartocci liboni, silas franco dos reis alves, “artificial neural network architectures and training processes” in ,artificial neural networks, springer international publishing switzerland, 2017, pp. 21-28. [17] mark hudson beale, martin t. hagan, haward b. demuth, neural network toolbox user’s, matlab, the math works, inc,2015. [18] arturas kaklauskas, “intelligent decision support systems”, intelligent systems, 2015, springer, doi: 10.1007/978-3-31913659-2_2. [19] rafik aziz aliev, “fundamentals of the fuzzy logic-based generalized theory of decisions”, fuzzy sets and fuzzy logic, springer, berlin, heidelberg, 2013, pp. 1-64. [20] mohd hilmi hasan, izzatdin abdul aziz, jafreezal jaafar, lukman ab rahim, joseph mabor agany manyiel, “a comparative study of mamdani and sugeno fuzzy models for quality of web services monitoring”, (ijacsa) international journal of advanced computer science and applications, vol.8, no. 9, 2017. [21] lhossein hassani & jafar zarei, “interval type-2 fuzzy logic controller design for the speed control of dc motors”, systems science & control engineering, published by taylor & francis, 2015. [22] guoqiang xia, guangning wu, bo gao, haojie yin and feibao yang, “a new method for evaluating moisture content and aging degree of transformer oil-paper insulation based on frequency domain spectroscopy”, energies, 2017, 10(08), 1195; mdpi, basel, switzerland, august, 20017. [23] cigre, guide on transformers intelligent condition monitoring (ticm) systems, working group a2.44. september, 2015. [24] cigre, guidelines for life management techniques for power transformers, draft final report rev. 2, 22 june 2002. [25] mark tostrud, brian d. sparling, ty a. foren, “monitoring, diagnoostics, or changing condition?”, ptpiree conference may 12 – 14th, 2015, gdannsk, poland. http://cired.net/publications/cired2015/papers/cired2015_0024_final.pdf http://cired.net/publications/cired2015/papers/cired2015_0024_final.pdf http://cired.net/publications/cired2015/papers/cired2015_0024_final.pdf http://cired.net/publications/cired2015/papers/cired2015_0024_final.pdf https://doi.org/10.1007/978-3-662-49434-9_9 https://doi.org/10.1007/978-3-662-49434-9_9 https://doi.org/10.1007/978-3-662-49434-9_9 https://doi.org/10.1007/978-3-662-49434-9_9 https://www.scientificbulletin.upb.ro/arhiva_2008/seria_c/nr3c-2008.pdf https://www.scientificbulletin.upb.ro/arhiva_2008/seria_c/nr3c-2008.pdf https://www.scientificbulletin.upb.ro/arhiva_2008/seria_c/nr3c-2008.pdf https://www.scientificbulletin.upb.ro/arhiva_2008/seria_c/nr3c-2008.pdf https://doi.org/10.3390/en11040913 https://doi.org/10.3390/en11040913 https://doi.org/10.3390/en11040913 https://doi.org/10.3390/en11040913 https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://e-cigre.org/publication/d1-204_2008-investigation-on-sampling-measurement-and-interpretation-of-gas-in-oil-analysis-for-power-transformers https://doi.org/10.1109/confluence.2016.7508041 https://doi.org/10.1109/confluence.2016.7508041 https://doi.org/10.1109/confluence.2016.7508041 https://doi.org/10.1109/confluence.2016.7508041 https://doi.org/10.1109/confluence.2016.7508041 https://doi.org/10.1007/s40565-015-0128-9 https://doi.org/10.1007/s40565-015-0128-9 https://doi.org/10.1007/s40565-015-0128-9 https://doi.org/10.1007/s40565-015-0128-9 https://doi.org/10.1016/j.ijepes.2015.04.020 https://doi.org/10.1016/j.ijepes.2015.04.020 https://doi.org/10.1016/j.ijepes.2015.04.020 https://doi.org/10.1016/j.ijepes.2015.04.020 https://doi.org/10.1016/j.ijepes.2015.04.020 https://doi.org/10.1016/j.egypro.2017.11.053 https://doi.org/10.1016/j.egypro.2017.11.053 https://doi.org/10.1016/j.egypro.2017.11.053 https://doi.org/10.1016/j.egypro.2017.11.053 http://dx.doi.org/10.1155/2014/275374 http://dx.doi.org/10.1155/2014/275374 http://dx.doi.org/10.1155/2014/275374 http://dx.doi.org/10.1155/2014/275374 https://bookstore.ams.org/iprob/ https://bookstore.ams.org/iprob/ https://bookstore.ams.org/iprob/ https://doi.org/10.1007/s40092-014-0069-3 https://doi.org/10.1007/s40092-014-0069-3 https://doi.org/10.1007/s40092-014-0069-3 https://doi.org/10.1007/s40092-014-0069-3 https://doi.org/10.1007%2f978-3-540-37372-8 https://doi.org/10.1007%2f978-3-540-37372-8 https://doi.org/10.1007%2f978-3-540-37372-8 https://doi.org/10.1007%2f978-3-540-37372-8 https://www.researchgate.net/publication/303075801_a_general_overview_of_power_transformer_diagnosis https://www.researchgate.net/publication/303075801_a_general_overview_of_power_transformer_diagnosis https://doi.org/10.1016/j.aasri.2014.05.007 https://doi.org/10.1016/j.aasri.2014.05.007 https://doi.org/10.1016/j.aasri.2014.05.007 https://doi.org/10.1016/j.aasri.2014.05.007 https://doi.org/10.1007/978-3-319-43162-8_2 https://doi.org/10.1007/978-3-319-43162-8_2 https://doi.org/10.1007/978-3-319-43162-8_2 https://doi.org/10.1007/978-3-319-43162-8_2 https://doi.org/10.1007/978-3-319-43162-8_2 https://www.mathworks.com/help/pdf_doc/nnet/nnet_ug.pdf https://www.mathworks.com/help/pdf_doc/nnet/nnet_ug.pdf https://www.mathworks.com/help/pdf_doc/nnet/nnet_ug.pdf https://doi.org/10.1007/978-3-319-13659-2_2 https://doi.org/10.1007/978-3-319-13659-2_2 https://doi.org/10.1007/978-3-319-13659-2_2 https://doi.org/10.1007/978-3-642-34895-2_1 https://doi.org/10.1007/978-3-642-34895-2_1 https://doi.org/10.1007/978-3-642-34895-2_1 http://dx.doi.org/10.14569/ijacsa.2017.080948 http://dx.doi.org/10.14569/ijacsa.2017.080948 http://dx.doi.org/10.14569/ijacsa.2017.080948 http://dx.doi.org/10.14569/ijacsa.2017.080948 http://dx.doi.org/10.14569/ijacsa.2017.080948 http://dx.doi.org/10.14569/ijacsa.2017.080948 https://doi.org/10.1080/21642583.2015.1013644 https://doi.org/10.1080/21642583.2015.1013644 https://doi.org/10.1080/21642583.2015.1013644 https://doi.org/10.1080/21642583.2015.1013644 https://doi.org/10.3390/en10081195 https://doi.org/10.3390/en10081195 https://doi.org/10.3390/en10081195 https://doi.org/10.3390/en10081195 https://doi.org/10.3390/en10081195 https://doi.org/10.3390/en10081195 https://e-cigre.org/publication/630-guide-on-transformer-intelligent-condition-monitoring-ticm-systems https://e-cigre.org/publication/630-guide-on-transformer-intelligent-condition-monitoring-ticm-systems https://e-cigre.org/publication/630-guide-on-transformer-intelligent-condition-monitoring-ticm-systems https://e-cigre.org/publication/elt_208_5-guide-for-life-management-techniques-for-power-transformers https://e-cigre.org/publication/elt_208_5-guide-for-life-management-techniques-for-power-transformers https://docplayer.net/20049006-monitoring-diagnostics-or-changing-condition.html https://docplayer.net/20049006-monitoring-diagnostics-or-changing-condition.html https://docplayer.net/20049006-monitoring-diagnostics-or-changing-condition.html mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology volume 08, 2017 authors index abdul halim, “increasing efficiency of a 33 mw otec in indonesia using flat-plate solar collector for the seawater heater,” 08(1): 33-39 ali alouache, “performance comparison of consensus protocol and l-φ approach for formation control of multiple nonholonomic wheeled mobile robots,” 08(1): 22-32 amun amri, “the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter,” 08(2): 95-102 andi imran, “frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm,” 08(2): 76-84 ary setijadi prihatmanto, “design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware,” 08(1): 60-69 carmadi machbub, “design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware,” 08(1): 60-69 dalila mat said, “a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer,” 08(1): 1-10 dwi lastomo, “optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system, ” 08(1): 11-21 egi muhammad idris hidayat, “design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware,” 08(1): 60-69 estiko rijanto, “comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study,” 08(1): 40-49 febrizal, “the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter,” 08(2): 95-102 fri murdiya, “the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter,” 08(2): 95-102 hendri novia syamsir, “a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer,” 08(1): 1-10 herlambang setiadi, “frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm,” 08(2): 76-84 herlambang setiadi, “optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system, ” 08(1): 11-21 irhan febijanto, “the impacts of a biofuel use on the gas turbine operating performance,” 08(2): 103-114 http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/351/performance-comparison-of-consensus-protocol-and-l--phi-approach-for-formation-control-of-multiple-nonholonomic-wheeled-mobile-robots http://www.mevjournal.com/index.php/mev/article/view/351/performance-comparison-of-consensus-protocol-and-l--phi-approach-for-formation-control-of-multiple-nonholonomic-wheeled-mobile-robots http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer http://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer http://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi irwan purnama, “increasing efficiency of a 33 mw otec in indonesia using flat-plate solar collector for the seawater heater,” 08(1): 33-39 iwan rohman setiawan, “increasing efficiency of a 33 mw otec in indonesia using flat-plate solar collector for the seawater heater,” 08(1): 33-39 james shippen, “simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study,” 08(2): 70-75 kadek heri sanjaya, “simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study,” 08(2): 70-75 latif rozaqi, “comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study,” 08(1): 40-49 midriem mirdanies, “experimental review of distance sensors for indoor mapping,” 08(2): 85-94 muhammad redho kurnia, “simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study,” 08(2): 70-75 muhammad ruswandi djalal, “frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm,” 08(2): 76-84 muhammad ruswandi djalal, “optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system, ” 08(1): 11-21 muji setiyo, “afr and fuel cut-off modeling of lpg-fueled engine based on engine, transmission, and brake system using fuzzy logic controller (flc),” 08(1): 50-59 qinghe wu, “performance comparison of consensus protocol and l-φ approach for formation control of multiple nonholonomic wheeled mobile robots,” 08(1): 22-32 reza aulia yulnandi, “design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware,” 08(1): 60-69 roni permana saputra, “experimental review of distance sensors for indoor mapping,” 08(2): 85-94 stratis kanarachos, “comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study,” 08(1): 40-49 suroto munahar, “afr and fuel cut-off modeling of lpg-fueled engine based on engine, transmission, and brake system using fuzzy logic controller (flc),” 08(1): 50-59 yukhi mustaqim kusuma sya’bana, “simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study,” 08(2): 70-75 yusmar palapa wijaya, “a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer,” 08(1): 1-10 http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/326/increasing-efficiency-of-a-33-mw-otec-in-indonesia-using-flat-plate-solar-collector-for-the-seawater-heater http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system http://www.mevjournal.com/index.php/mev/article/view/361/optimization-of-smes-and-tcsc-using-particle-swarm-optimization-for-oscillation-mitigation-in-a-multi-machines-power-system http://www.mevjournal.com/index.php/mev/article/view/374/afr-and-fuel-cut-off-modeling-of-lpg-fueled-engine-based-on-engine--transmission--and-brake-system-using-fuzzy-logic-controller--flchttp://www.mevjournal.com/index.php/mev/article/view/374/afr-and-fuel-cut-off-modeling-of-lpg-fueled-engine-based-on-engine--transmission--and-brake-system-using-fuzzy-logic-controller--flchttp://www.mevjournal.com/index.php/mev/article/view/351/performance-comparison-of-consensus-protocol-and-l--phi-approach-for-formation-control-of-multiple-nonholonomic-wheeled-mobile-robots http://www.mevjournal.com/index.php/mev/article/view/351/performance-comparison-of-consensus-protocol-and-l--phi-approach-for-formation-control-of-multiple-nonholonomic-wheeled-mobile-robots http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/376/design-and-implementation-of-hardware-in-the-loop-simulation-for-electric-ducted-fan-rocket-control-system-using-8-bit-microcontroller-and-real-time-open-source-middleware http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/369/comparison-between-rls-ga-and-rls-pso-for-li-ion-battery-soc-and-soh-estimation--a-simulation-study http://www.mevjournal.com/index.php/mev/article/view/374/afr-and-fuel-cut-off-modeling-of-lpg-fueled-engine-based-on-engine--transmission--and-brake-system-using-fuzzy-logic-controller--flchttp://www.mevjournal.com/index.php/mev/article/view/374/afr-and-fuel-cut-off-modeling-of-lpg-fueled-engine-based-on-engine--transmission--and-brake-system-using-fuzzy-logic-controller--flchttp://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer http://www.mevjournal.com/index.php/mev/article/view/285/a-compact-design-of-multi-feeder-data-logging-system-for-power-quality-measurement-with-a-multiplexer-and-a-single-pq-transducer journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 08, 2017 affiliation index centre for mobility & transport, coventry university, coventry, united kingdom 40 centre for technology of energy resources development, deputy for technology of informatic, energy and mineralbppt, tangerang selatan, indonesia 103 centre of electrical energy systems (cees), university technology malaysia (utm), johor bahru, malaysia 1 department of automotive engineering, universitas muhammadiyah magelang, magelang, indonesia 50 department of chemical engineering, faculty of engineering, universitas riau, indonesia 95 department of electrical engineering, faculty of engineering, universitas riau, riau, indonesia 95 department of electrical engineering, faculty of engineering, university of indonesia, depok, indonesia 33 department of electrical engineering, sepuluh nopember institut of technology, surabaya, indonesia 76 department of mechanical and automotive engineering, coventry university, coventry, united kingdom 70 department of mechanical engineering, ujung pandang state polytechnics, makassar, indonesia 11, 76 dyson school of design engineering, imperial college london, london, united kingdom 85 electronics engineering, polytechnic caltex riau, riau, indonesia 1 industrial design, keimyung university, daegu, south korea 70 research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), bandung, indonesia 40, 70, 85 school of automation, beijing institute of technology, beijing, china 22 school of electrical engineering and informatics, institut teknologi bandung, bandung, indonesia 60 school of information technology & electrical engineering, the university of queensland, brisbane, australia 11, 76 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii technical implementation unit for instrumentation development, indonesian institute of sciences (lipi), bandung, indonesia 33 upmb institut teknologi sepuluh nopember, surabaya, indonesia 11 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. ir. suhono h supangkat, m.eng, cgeit. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. dr. ir. zainal abidin mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. ir. adi soeprijanto, mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. iman k reksowardojo mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135 indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university jl.grafika2, yogyakarta 55281, indonesia ocktaeck lim, ph. d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan korea, republic of dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia ir. edi leksono, m.eng, ph.d. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha cahyadi department of electrical engineering, gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia esa prakasa, ph.d research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2ndfl, bandung 40135, indonesia dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. sunit hendrana research center for physics lipi komp lipi jl sangkuriang, blg 60, 2nd fl, bandung 40135, indonesia dr. ary setijadi prihatmanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. feri yusivar, m.eng department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, st., mt. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia aji prasetya wibawa, ph.d department of electrical engineering state university of malang jl. semarang no. 5, malang, jawa timur, indonesia dr. widodo budi santoso research centre for electical power and mechatronics-lipi komp lipi jl sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia slamet riyadi, s. ds., m.ds. product design department faculty of art and design bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. agfianto eko putra, m.sc department of computer and electronic science gadjah mada university jl.grafika 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering institut teknologi nasional jl. phh. mustafa no. 23, bandung , jawa barat, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, south korea dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with semi colon and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and maske a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register microsoft word vol.01_no.1_v3 issn 2087-3379 journal of mechatronics, electrical power and vehicular technology volume 01 nomor 1, 2010 penanggung jawab kepala pusat penelitian tenaga listrik dan mekatronik lipi ketua dewan editor dr.eng. estiko rijanto (mechatronics and control systems) editor pelaksana ghalya pikra, m.t. (teknik mesin, konversi energi) naili huda, m.eng.sc. (teknik industri, transportasi) noviadi arief rachman, m.t. (teknik tenaga listrik) tinton dwi atmaja, m.t. (elektro informatika) editor ahli dr.eng. budi prawara (material engineering) dr.-ing. moch ichwan (vehicular technology) pudji irasari, m.sc.rer.nat. (electrical power) mitra bestari prof.dr. jamasri (teknik mesin/struktur; ugm) dr. arko djajadi (mekatronika; swiss german university) sekretariat henny sudibyo, m.t. (sekretariat) roni permana saputra, s.t. (sekretariat) benua grahana sontani, a.md. (web admin) desain grafis m. redho kurnia, s.sn. (desain) jurnal ini tebit 2 (dua) kali dalam setahun journal of mechatronics, electrical power and vehicular technology adalah jurnal ilmiah yang diterbitkan oleh pusat penelitian tenaga listrik dan mekatronik lembaga ilmu pengetahuan indonesia (lipi). jurnal ini memuat karya ilmiah yg berupa hasil penelitian, pengembangan dan penerapan dalam bidang ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya. alamat redaksi sekretariat jurnal pusat penelitian tenaga listrik dan mekatronik lipi komp lipi jl. sangkuriang, gd. 20, lt. 2, ruang 229 bandung, jawa barat, 40135 telp: 022-2503055/2504770 fax: 022-2504773 e-mail: permana.saputra@yahoo.co.id website: www.mevjournal.com www.telimek.lipi.go.id issn 2087-3379 i journal of mechatronics, electrical power and vehicular technology volume 01 nomor 1, 2010 kata pengantar ketua dewan editor puji dan syukur kami panjatkan kepada tuhan yang maha esa, atas berkat dan karunia-nya kami dapat mempublikasikan journal of mechatronics, electrical power, and vehicular technology (jmev) volume 01 nomor 1 tahun 2010 ini. atas nama dewan editor kami mengucapkan terimakasih atas kerjasama dan kontribusi berbagai pihak yang telah membantu terbitnya jurnal ini. pada jmev vol. 01 no. 1 tahun 2010 ini dimuat 5 makalah yang telah melalui seleksi penilaian berjenjang oleh editor pelaksana, editor ahli dan mitra bestari sesuai dengan prosedur operasi standar yang ada. satu makalah tentang survey potensi air untuk pembangkit listrik mikro hidro, satu makalah tentang konsep pembangkit listrik tenaga arus laut, satu makalah tentang pengujian vibrasi generator magnet permanen, satu makalah tentang material untuk pelapisan, dan satu makalah tentang analisis penyimpan panas untuk pembangkit listrik tenaga panas matahari. kami mengucapkan selamat membaca dan semoga publikasi ini dapat turut menjadi sumbangsih bagi kemajuan ilmu pengetahuan dan teknologi pada umumnya, dan kemajuan bangsa pada khususnya. bandung, 30 september 2010 ketua dewan editor issn 2087-3379 ii journal of mechatronics, electrical power and vehicular technology volume 01 nomor 1, 2010 daftar isi mikrostruktur dan karakterisasi sifat mekanik lapisan cr3c2-nial-al2o3 hasil deposisi dengan menggunakan high velocity oxygen fuel thermal spray coating edy riyanto, budi prawara 1-4 survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam ridwan arief subekti 5-12 analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari ghalya pikra, agus salim, tri admono, merry indahsari devi 13-18 analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik pudji irasari, aditya sukma nugraha, muhamad kasim 19-26 ocean current energy conversion system in wallacea region using variable speed control approach aditya sukma nugraha, estiko rijanto 27-34 mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2018.v9.25-31 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. pendulum energy harvester with amplifier michal černý *, michal dzurilla, miloš musil, marek gašparík faculty of mechanical engineering, slovak university of technology námestie slobody 17, 812 31 bratislava, slovakia received 23 january 2018; received in revised form 04 may 2018; accepted 14 june 2018 published online 31 july 2018 abstract this paper presents a new principle of inductive vibration power harvester. harvester is a pendulum that uses energy capacitor which is the mass. the mass is connected to the pendulum via a gearbox to achieve greater movement of the pendulum that generates an electromagnetic voltage. the harvester is developed at a very low frequency (1 to 10 hz) which uses the rectified magnetic fluxes. magnets are statically placed in the harvester case, and relative motion is carried out by the coil. magnets are static, and the coil moves due to the weight ratio of magnets which the steel leads of the magnetic flux and the coil itself. this paper is focused on a harvester with a mechanical amplifier with the proposed technique is brings the plow harvester access with an auxiliary force. the experimental results indicate that the optimal results of the harvester with an accumulator for the resonant zone are 3.75 hz, 7 hz, and 10 hz. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: pendulum; energy; harvester; amplifier; vibration. i. introduction today, given the wireless data transmission, sensors are limited by the necessity of electric power supply. when using the cable system to power the devices, the advantages of wireless communication are considerably reduced. using batteries is not the best solution because of their durability and limited working conditions. to push the limits of the possibilities for technical control and management, the new alternatives based on the inexhaustible energy sources in the close distance around the power system are investigated. one of the most effective alternative ways to supply power to electronic devices is by utilizing the surrounding vibrations. however, kinetic parameters of the standard environment, including human movement, the vibration of bridges, buildings, machines, and many devices are low frequency. to solve this problem, many solutions were designed, such as utilization of resonance oscillation, mechanical frequency, or rotating movement with eccentric mass [1]. performance of these systems goes down out of the appropriate conditions range whenever big static displacement, non-periodic vibrations, and low amplitude exist. the range is usually narrow, which is a huge disadvantage. the opposite approach to this solution is “direct force” where vibrations are transmitted only by transfer multiplying amplitude and frequency [2]. although these solutions tend to create less energy compared to resonance harvesters, these also have the advantage of a wider excitation band. the however, these solutions might not be applicable everywhere, especially for vehicles and enclosed spaces, where only a relative movement to the earth that can be utilized. therefore, this paper is focused on the harvester with the mechanical amplifier. the proposed solution brings the plow harvester access with an auxiliary force. it accumulates in a mechanical condenser. the transformation of the excitation of the excised mass (capacitor) in the translational motion is associated with the pendulum through the constrained accouplement. the layout has proven to be suitable for very low excitation frequencies and further research. there are a large number of physical phenomena combinations that are used to construct the collector. different ways of storing resonant and power components that have a * corresponding author. tel: +421 91 017 8503 e-mail address: m.michal.cerny@gmail.com https://dx.doi.org/10.14203/j.mev.2018.v9.25-31 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.25-31 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.25-31&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 26 tremendous impact on performance. the proposed harvester is unique due to its solution that offers options for further innovation in its extensive development. ii. harvester assembly the principle of capturing vibration energy is the resonant operation of the oscillation mass and the subsequent electromechanical transformation into electrical energy [3]. these devices work correctly only in narrow resonant bandwidth. therefore, the energy collector structure is tuned into a resonant frequency of operation that is the same as the dominant vibration frequency. the excited oscillation movement inside the mechanism is transformed by a certain physical principle of electromechanical conversion. vibration energy collecting devices typically use the principles of piezoelectric, electrostatic, electromagnetic, or magnetostrictive conversion [4]. schematic diagram of the vibration energy harvester principle is shown in figure 1 [5]. mechanical vibrations generate the mass of the resonant mechanism, and the relative movement of mass with the magnetic circuit against the solid coil (vice versa) leads to tension due to faraday's law. the current flows through the connected electronics (electrical load), and then the output power is harvested. the vibration pickup bandwidth is a key element in gaining energy from mechanical vibrations. nonlinear stiffness is therefore used to extend the working bandwidth of non-linear vibration energy harvesting devices [6][7]. non-linear behavior can be ensured by several designs of flexible elements, pendulum architecture [8], mems structure of electrostatic collectors [9], resilient spiral structures of polymer resonators [1], or a set of permanent repellent magnets [10]. the combination of magnetic forces and mechanical spring provides another possibility of nonlinear operation with extended bandwidth operation [11][12]. an electromechanical power generator is proposed for converting mechanical energy in the form of lowfrequency vibrations that available in the measurement environment into electrical energy. the intended applications for the proposed electromechanical power generator described in this paper are for examples mechanical systems with lower frequency vibrations (1 to 10 hz). the main mean of the phenomenon explored is an oscillating body which can amplify small amplitude 0.325 r-times because of an amplifying gear connected to a coil on a crank. the system of magnets in the trajectory of the coil multiplies the frequency four times to give a maximum oscillation. the scheme of the oscillating body harvester is shown in figure 2. according to the figure 2, it was shown that a pendulum connected to the base with a mass “m2”, and its center of gravity in a distance “r” from the rotation axis and the inertia "i". a gear wheel radius is “r”. the gear ratio is 1 mm = 18°. the harvester is performed optimally by the acceleration of the ambient vibration a(t), k stiffness, dm mechanical damping and de electrical damping. the magnetic field of magnets is paired and connected by steel plates. b is a vector of magnetic flux density. the generator implements a novel configuration of magnets that is proposed and analyzed with the aim to improve the conversion efficiency and increase the spatial variation of magnetic flux. to create a proper design of individual parts which define its parameters and efficiency, the equations have been assembled to be processed in matlab and other analytical programs. the axial stiffness k, which calculated in equation (1) was purposed to add the measured values obtained during the load test. meanwhile, f is the load force, and δy is the difference in which the spring length has changed. in equation (2), the relation between displacement of the mass m and change in an angle of the pendulum φ is defined, and the respective velocity values are yielded by the derivation. in equation (3), the kinetic energy has modified, as all of the single variable φ. for simplicity, a gear wheel and a pendulum have been put with a spool into the inertia of the coil. afterwards, the equation (4) is generated with potential energy. all elements in the system, containing energy terms are rearranged into the basic figure 1. schematic diagram of vibration energy harvester principle figure 2. schematic of the oscillating body harvester m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 27 2nd order lagrangian equation (5) with d is the dissipative energy, ep is potential energy, ek is kinetic energy and qj are generalized forces. 𝑘 = 𝐹 ∆𝑦 (1) 𝑥 = 𝑟 𝑠𝑖𝑛𝜑 → �̇� = �̇� 𝑟 𝑐𝑜𝑠𝜑 (2) 𝐸𝑘 = 1 2 𝑚�̇�2 + 1 2 𝐼�̇�2 = 1 2 𝑚 𝑟2�̇�2𝑐𝑜𝑠2𝜑 + 1 2 𝐼�̇�2 (3) 𝐸𝑝 = 1 2 𝑚2𝑔𝑅(1 − 𝑐𝑜𝑠𝜑) + 𝑘𝑟 𝑠𝑖𝑛𝜑 (4) 𝑑 𝑑𝑡 ( 𝜕𝐸𝑘 𝜕�̇� ) − 𝜕𝐸𝑘 𝜕𝜑 + 𝜕𝐸𝑝 𝜕𝜑 + 𝜕𝐷 𝜕�̇� = 𝑄𝑗 (5) 𝜕𝐸𝑘 𝜕�̇� = 𝜕 𝜕�̇� ( 1 2 𝑚𝑟2𝜑2̇𝑐𝑜𝑠2𝜑 + 1 2 𝐼𝜑2̇) = 𝑚𝑟2�̇� 𝑐𝑜𝑠2𝜑 + 𝐼�̇� (6) the kinetic energy is further adjusted by partial derivation in equation (6) and equation (7). then the potential energy of the saturation is expressed in equation (8) and equation (9). 𝑑 𝑑𝑡 ( 𝜕𝐸𝑘 𝜕�̇� ) = 𝑚𝑟2𝜑 ̈ 𝑐𝑜𝑠2𝜑 − 2𝑚𝑟2�̇� 𝑐𝑜𝑠𝜑 𝑠𝑖𝑛𝜑 + 𝐼�̈� = 𝑚𝑟2(�̈�𝑐𝑜𝑠2𝜑 − �̇� sin(2𝜑)) + 𝐼𝜑 ̈ (7) 𝜕𝐸𝑝 𝜕𝜑 = 1 2 𝑘𝑟2𝑠𝑖𝑛2𝜑 + 1 2 𝑚2𝑔𝑅 𝑠𝑖𝑛𝜑 (8) 𝜕𝐸𝐷 𝜕𝜑 = 1 2 𝑅2𝑏𝑒𝜑 2̇ + 1 2 𝑏𝑚𝑟 2𝜑2̇𝑐𝑜𝑠2𝜑 (9) all acquired energy is set in equation (5), from which the equation (10) is obtained. 𝑚𝑟2(�̈�𝑐𝑜𝑠2𝜑 − �̇� 𝑠𝑖𝑛2𝜑) + 𝐼�̈� + 1 2 𝑚𝑟2�̇�2 sin(2𝜑) + 1 2 𝑚2𝑔𝑅 𝑠𝑖𝑛𝜑 + 𝑘𝑟 𝑠𝑖𝑛𝜑 + 1 2 𝑅2𝑏𝑒𝜑 2̇ + 1 2 𝑏𝑚𝑟 2𝜑2̇𝑐𝑜𝑠2𝜑 = 0 (10) before finishing the basic description of the system, the equation (11) is arranged as follow: �̈�[𝑚𝑟2𝑐𝑜𝑠2𝜑 + 𝐼] + �̇�2 1 2 𝑚𝑟2 𝑠𝑖𝑛2𝜑 − �̇�𝑚𝑟2 𝑠𝑖𝑛2𝜑 + 1 2 𝑅2𝑏𝑒𝜑 2̇ + 1 2 𝑏𝑚𝑟 2𝑠𝑖𝑛2�̇� + 1 2 𝑚2𝑔𝑅 𝑠𝑖𝑛𝜑 = 0 (11) the magnetic circuit with permanent magnets is firmly attached to the frame of the harvester. coil with the oscillated mass is part of the oscillating resonance mechanism. this design provides magnetic fields with a vector of magnetic flux and density b. the velocity of the moving coil against fixed magnetic circuit induced voltage due to faraday's law in accordance with equation (12). the induced voltage ui depends on the velocity of magnetic circuit 𝑥 = 𝑟 𝑠𝑖𝑛𝜑 and magnetic flux density b through activate the length of the coil l with known number of coil turns n. 𝑢𝑖 = 𝑁 ∮ (𝑥 × �⃗� )𝑑𝑟 0 𝑙 (12) the resonance frequency ω is determined by the stiffness k and mass m ratio as shown in equation (13). 𝛺 = √ 𝑘 𝑚 (13) periodic excitation optimally transferred and stored into the energy vibration system. because of this repeated storage and additional energy input, the system swings stronger until its load limit is exceeded. iii. model of construction in this study, defining assignments and solving tasks for designing a low frequency harvester were proceeded with a simple model that was tuned by experiments. the overall process of the energy harvesting device development is shown in figure 3. the model of the harvester is implemented to multibody dynamics (mbd) software, adams together with matlab software. using these types of software, the relatively accurate response of the system to the input parameters is obtained. for a better vision of the total distribution of single particles in the harvester, a view from a slight angle of the profile is shown in figure 4. due to more complicated harvester with several new solutions, the static and supportive parts of the collector are removed as shown in figure 5. one of the four magnetic pairs on the steel sheet was taken away for the position of a pendulum with a coil. the harvester design is not final, and it is intended for laboratory experiments. therefore, it is designed spatially without higher claim of the frame. figure 3. diagram of the energy harvesting device m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 28 iv. result and discussion based on the model, a prototype was created as shown in figure 6 which also serves to verify the analytical model. this prototype can be used for tuning the system for further development. measurements have shown the best results when keeping dynamic parameters of 3 to 7 hz and excitation amplitude of ± 2 mm, respectively. the asymmetric progress of generating voltage was caused by the incomplete track of the coil between the magnets, and also their non-linear velocity in the given sections between the magnetic pairs. figure 7 has shown the captured progress of a voltage at the resistance of 240 ω, excitation frequency 3 hz, amplitude ± 3, and upk-pk = 4.04 v. in table 1, dimensions of the energy harvester were recorded with the holder based on the prototype that has been made in laboratory scale. meanwhile, table 2 has shown recorded electrical energy from the harvester. the obtained advantage was there were two parts which respond together up to three zones resonance. when comparing to harvester, it was also sized from 3 to 10 hz, and had the approximately same dimensions. the harvester with the parameters was shown in figure 8 [13], a magnetic field between two magnetic materials was served virtual mechanical spring. the harvester is 200 cm high is capable of producing 100 to 200 mv with a voltage of 4,500 mv. resonance of the given values has reached up from 3.5 to 6.5 hz and accelerated to 10 m/s. the advantage of the present harvester was up to 3 times the lesser acceleration needed to achieve resonance. the overall trend of the generated voltage was shown in figure 9. there were two resonance curves. the top curve has shown a generated voltage of 240 ω without direction. the lower curve has described the value after the direction of generated voltage. undirectional voltage has been measured through a graetz bridge made of schottky diode and 220 μf smoothing capacitor. schotty diode opens the circuit from a voltage of 0.3 v and due to the stiffness of the mechanism it is possible to reach the resonant zone. figure 4. the model of the assembly from the profile: 1) wheel for oscillating mass, 2) oscillate mass, 3) gear wheel, 4) pendulum, 5) adjustable holder for adjusting the position of magnets, 6) ndfeb magnets, and 7) the steel plate table 1. dimensions of the harvester laboratory assemblies. parameters value height 100 width 50 depth 50 unit mm table 2. summary of optimal performance information. parameters value unit f 3 hz a 2 mm rl 240 ω rc 30 ω upk 4 v u 1.2 v p 440 µw m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 29 figure 5. selected main parts of the model from the profile: 2) oscillate mass, 6) ndfeb magnets, 7) the steel plate, 8) coil, 9) spring, 10) gear rack of mass m, and 11) spacer support of spring figure 6. the prototype printed on a 3d printer m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 30 v. conclusion the harvester with an accumulator has shown the optimal results in a wider spectrum of frequencies for resonant zone 3.75 hz, 7 hz, and 10 hz, which allowed non-linear damping by magnets and the addition of an oscillating mass. measured experimental results were the highest for the frequency of 3.75 hz with power (p) = 3.6 mw, volume power (pv) = 14.4 μw/cm3 and dc = 2000 mv. the disadvantage of the harvester was the loss of energy in the toothed gear. further research should be focused on how to eliminate the energy loss. great opportunities appear mainly in the alternative folding of magnetic field lines, which can streamline the various non-standard system of oscillating bodies. acknowledgement authors would like to thank veronika o. for her willingness and help. references [1] e. sardini and m. serpelloni, "an efficient electromagnetic power harvesting device for low-frequency applications," sensors and actuators, a: physical, vol. 172, pp. 475-482, 2011. [2] i. shahosseini and k. najafi, "mechanical amplifier for translational kinetic energy harvesters," journal of physics: conference series, vol. 557, p. 012135, 2014. [3] s. priya and d. j. inman, "energy harvesting technologies," energy harvesting technologies, pp. 1-517, 2009. [4] l. mateu and f. moll, "review of energy harvesting techniques and applications for microelectronics," in figure 7. the progress of a voltage at the resistance of 240 ω, excitation frequency 3 hz, and amplitude ± 3, upk pk = 4.04 v figure 8. the harvester with the specification: 200 centimeters high, capable of producing 100 to 200 mv with a voltage of 4,500 mv figure 9. the overall trend of the generated voltage https://doi.org/10.1016/j.sna.2011.09.013 https://doi.org/10.1016/j.sna.2011.09.013 https://doi.org/10.1016/j.sna.2011.09.013 https://doi.org/10.1016/j.sna.2011.09.013 https://doi.org/10.1088/1742-6596/557/1/012135 https://doi.org/10.1088/1742-6596/557/1/012135 https://doi.org/10.1088/1742-6596/557/1/012135 https://doi.org/10.1007/978-0-387-76464-1 https://doi.org/10.1007/978-0-387-76464-1 https://doi.org/10.1117/12.613046 https://doi.org/10.1117/12.613046 m. černý et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 25–31 31 proceedings of spie vol. 5837, j. f. lopez, et al., eds., ed: international society for optics and photonics, 2005, pp. 359373. [5] z. hadas, et al., "power sensitivity of vibration energy harvester," microsystem technologies, vol. 16, pp. 691-702, 2010. [6] l. gammaitoni, et al., "nonlinear oscillators for vibration energy harvesting," applied physics letters, vol. 94, p. 164102, 2009. [7] a. cammarano, et al., "bandwidth of a nonlinear harvester with optimized electrical load," journal of physics: conference series, vol. 476, p. 012071, 2013. [8] t. w. ma, et al., "a novel parametrically excited non-linear energy harvester," mechanical systems and signal processing, vol. 28, pp. 323-332, 2012. [9] s. d. nguyen and e. halvorsen, "nonlinear springs for bandwidth-tolerant vibration energy harvesting," journal of microelectromechanical systems, vol. 20, pp. 1225-1227, 2011. [10] s. w. guan, et al., "finite element modeling and experimental verification of a suspension electromagnetic energy harvester," applied mechanics and materials, vol. 444-445, pp. 879-883, 2013. [11] s. g. burrow and l. r. clare, "a resonant generator with non-linear compliance for energy harvesting in high vibrational environments," in 2007 ieee international electric machines & drives conference, ed: ieee, 2007, pp. 715-720. [12] j. yang, et al., "a magnetoelectric-based broadband vibration energy harvester for powering wireless sensors," science china technological sciences, vol. 54, pp. 1419-1427, 2011. [13] b. p. mann and b. a. owens, "investigations of a nonlinear energy harvester with a bistable potential well," journal of sound and vibration, vol. 329, pp. 1215-1226, 2010. https://doi.org/10.1117/12.613046 https://doi.org/10.1117/12.613046 https://doi.org/10.1117/12.613046 https://doi.org/10.1007/s00542-010-1046-4 https://doi.org/10.1007/s00542-010-1046-4 https://doi.org/10.1007/s00542-010-1046-4 https://doi.org/10.1063/1.3120279 https://doi.org/10.1063/1.3120279 https://doi.org/10.1063/1.3120279 https://doi.org/10.1088/1742-6596/476/1/012071 https://doi.org/10.1088/1742-6596/476/1/012071 https://doi.org/10.1088/1742-6596/476/1/012071 https://doi.org/10.1016/j.ymssp.2012.01.017 https://doi.org/10.1016/j.ymssp.2012.01.017 https://doi.org/10.1016/j.ymssp.2012.01.017 https://doi.org/10.1109/jmems.2011.2170824 https://doi.org/10.1109/jmems.2011.2170824 https://doi.org/10.1109/jmems.2011.2170824 https://doi.org/10.1109/jmems.2011.2170824 https://doi.org/10.4028/www.scientific.net/amm.444-445.879 https://doi.org/10.4028/www.scientific.net/amm.444-445.879 https://doi.org/10.4028/www.scientific.net/amm.444-445.879 https://doi.org/10.4028/www.scientific.net/amm.444-445.879 https://doi.org/10.1109/iemdc.2007.382755 https://doi.org/10.1109/iemdc.2007.382755 https://doi.org/10.1109/iemdc.2007.382755 https://doi.org/10.1109/iemdc.2007.382755 https://doi.org/10.1109/iemdc.2007.382755 https://doi.org/10.1007/s11431-011-4367-3 https://doi.org/10.1007/s11431-011-4367-3 https://doi.org/10.1007/s11431-011-4367-3 https://doi.org/10.1016/j.jsv.2009.11.034 https://doi.org/10.1016/j.jsv.2009.11.034 https://doi.org/10.1016/j.jsv.2009.11.034 mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2017.v8.103-114 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. the impacts of a biofuel use on the gas turbine operating performance irhan febijanto * centre for technology of energy resources development, deputy for technology of informatics, energy, and mineral bppt cluster 5 of energy building, puspiptek, tangerang selatan 15314, indonesia received 19 november 2017; received in revised form 14 december 2017; accepted 15 december 2017 published online 28 december 2017 abstract the use of pure plant oil (ppo) as a fuel blend in a power plant is mandatory as stipulated in the ministerial decree of energy and mineral resource of the republic of indonesia. however, the implementation of ppo used in power generation has many obstacles due to a lack of information concerning the impacts of ppo used in the operating performance of the power generation engine. in this study, the effect of ppo as a blended fuel with high-speed diesel (hsd) was studied by using the gas turbine with a capacity of 18 mw. the ppo was blended based on volume with a ratio of 0%, 5%, 10%, and 20%. as the results, it is shown that the use of ppo with a blend ratio of 20% is the maximum fuel blend ratio according to the threshold value of a flue gas temperature and a vibration velocity in the gas turbine. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: gas turbine power plant; pure plant oil; high-speed diesel; blended fuel. i. introduction the republic of indonesia as the biggest palm oil producer country has a significant potential to utilize palm oil as an alternative energy source. the ministerial decree of energy and mineral resource no. 25 year 2013 concerning on amendment to the previous ministerial regulation no. 32 year 2008 concerning provision, utilization, and trade of biofuel as an alternative energy has been published. according to the ministerial decree, the use of biodiesel and pure plant oil (ppo) are mandatory in power generation plant with blend ratio determined gradually. the mandatory ratio of ppo used was 6% in 2014 and increased to 15% in 2015 and at last, was 20% in 2016. ppo is a pure vegetable oil extracted from palm oil that has no chemical change. it has been used as an alternative fuel to increase a reduction of fossil fuel consumption. pure plant oil is also known as straight vegetable oil (svo). however, until now, ppo as an alternative fuel of power generation plant is only implemented at diesel power generation plant only, with a used ratio of ppo is 50% [1]. the implementation of ppo that used in another kind of power generation plant is not yet conducted due to a lack of know-how related to the use of ppo, and there is a big concern about the impact on the engine operating performance. the previous studies show that studies on the use of svo or ppo as a blended fuel in a gas turbine were conducted limited only for a micro gas turbine that has a capacity below 1 mw or only for laboratory scale study [2] [5]. therefore, the impact of ppo fuel blend on the gas turbine operating performance is still insufficient. an increase in ppo blend ratio will increase a fuel viscosity, which affects an atomization condition in nozzles and a combustion condition in the combustion chamber. however, by increasing an injection temperature of ppo fuel, the effects of viscosity on an atomization pressure at the nozzle and an incomplete combustion at combustor chambers can be minimized [2], [3], [5]. the increase of the temperature in the combustor chambers leads to increase on nox emission level and decrease on co emission level [4], [5]. the impacts of ppo used on a safety and a stability of the gas turbine operating performance can be known obviously, after a long period of operating time. unfortunately, there is no investigation * corresponding author. tel: +62 812 1303 020 e-mail address: irhan.febijanto@gmail.com https://dx.doi.org/10.14203/j.mev.2017.v8.103-114 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.103-114 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.103-114&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 104 regarding the impacts of ppo as a gas turbine fuel concerning a safety and a stability on the gas turbine performance for a long operating time. this study aims to determine the impacts of fuel blend of high-speed diesel (hsd) and ppo on the gas turbine operating performances. the gas turbine operated at 100% load during peak hours for several days, with a total operating period of 40 hours. the ratio of ppo was 0%, 5%, 10%, and 20%, based on the volume. the hsd-ppo fuel blend was preheated and mixed homogeneously by using the blending facility dedicated built for this study. the impacts of hsd-ppo fuel blend on the gas turbine operating performance were observed by using the gas turbine operating parameters including the flue gas. the flue gas parameters were used as indicators for a qualitative evaluation of the combustion process. ii. research method figure 1 showed the flowchart of the experiment in this study. the viscosity and the spray angle test were conducted in the laboratory. the gas turbine operating performance test was conducted at the site where the gas turbine located. in the viscosity test, a correlation between an enhancement in temperature and viscosity of the hsdppo fuel blend (here in after referred as to sample) was investigated by using a viscometer sv-10. the viscosity of the sample for ppo with a volume ratio of 0% (hsd 100%), 5%, 10%, 20%, and 30% was measured at each temperature rise of 5°c. the test was conducted based on astm d45. a spray angle test was carried out to determine the temperature effect on the spray angle at the nozzle for each sample. the type and the size of nozzle were the same with the nozzle used in the gas turbine. the angle was measured by a visual measurement through a glass viewing window. the temperature of each sample was adjusted until the spray angle was the same as the standard spray angle of 60°. the gas turbine operating performance test was conducted in the site by using the gas turbine as shown in figure 2. the standard fuel of the gas turbine is hsd. during the study, there was no adjustment in the gas turbine engine including the a/f ratio. the specification of the gas turbine was shown in table 1 [6]. the gas turbine had been operated since 1983 and recently is operated as a peaker power plant, which operated at 100% load during peak hours every day. the capacity had derated to 18 mw from 21 mw. the items and the data sources of the operating performance test were shown in table 2. the monitoring item was monitored and recorded with a specific interval during 40 hours at a peak hour (20:00 03:00) for several days, at the maximum load. load performances consist of a speed of a compressor and generator, frequency, and power output. figure 3 showed the schematic diagram of the operating performance test. dotted line indicated the measurement instruments, which a part of the gas turbine system. straight line indicated the measurement instrument, which installed during the experiment. fuel flow rate, pressure nozzle, flue gas temperature, vibration velocity, turbine speed, compressor speed, noise level, power output and figure 1. flowchart of the experiment figure 2. gas turbine pg 5341 table 1. specification of gas turbine [6] specification value type pg 5341 manufacturer gec alstom capacity 18.0 mw compressor + turbine speed 5,100 rpm compressor stages 17 turbine stages 2 combustor (nozzle) 10 (10) generator speed 3,000 rpm table 2. operating performance parameters no monitoring item monitoring point/ data resource 1 load performance data logger control room 2 specific fuel consumption (sfc) flow rate taken from flow counter, kwh taken from kwh meter in the control room 3 vibration point 1 (compressor bearing at the air inlet inside), point 2 (compressor body), point 3 (generator bearing at the front of generator shaft), point 4 (generator bearing at the behind of generator shaft). 4 nozzle pressure monitor in the control room 5 deposit visual observation 6 flue gas flue gas duct 7 flue gas temperature monitor in the control room 8 noise level monitor in the control room i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 105 figure 3. flowchart of the experiment frequency were measured by the existing measurement instruments, which was a part of the gas turbine system. the measured values were recorded manually taken from monitoring displays in the control room by a one-hour interval. exhaust gas analyzer was installed during the experiment.the analyzer was used for measuring flue gas velocity and flue gas level. vibration velocity was measured at four points located at air inlet side of the compressor bearing (point 1), at the compressor body (point 2), at front side (point 3) and behind the generator bearing (point 4). a measurement instrument of noise was at the side of the turbine and the side of the generator. specific fuel consumption (sfc) was the calculation result derived from a sample flow rate measured by the flow counter installed at the inlet supply pipe of the gas turbine and power generated which recorded by kwh meter in the control room. the interval recording was one hour. figure 4 showed the activity of making holes for the exhaust gas analyzer. the monitoring instrument of the analyzer was located below the flue gas duct. flue gas level measurement was conducted according to several standards. to determine the number of sampling holes in a flue gas duct, indonesia national standard / standar nasional indonesia (sni) 7117.13:2009 was implemented. flue gas velocity was measured by type-s pitot tube, and the measurement procedures were conducted according to sni 7117.14:2009. to calculate the flue gas velocity, a weight of gas molecules and water content in the gas molecules was required to be known previously. sni 7117.15:2009 and sni 7117.16:2009 were used to calculate the flue gas velocity. all measurement related to the flue gas was conducted after the gas turbine operates steadily which usually achieved in two or three hours after the experiment had started. the measurement result was corrected to 15% of oxygen level to prevent the concentration of pollutant being achieved by dilution of the exhaust with air. a visual observation of formed deposit at nozzles was conducted after the nozzle was released. it was carried out after the experiment for each sample completed, in the cold condition. figure 5 showed the blending facility that had a capacity of 8,000 ltr/hr. the facility was constructed to support this study and located behind the gas turbine plant. using the blending facility, the sample was preheated and blended homogeneously. figure 6 showed sub facilities of the blending facility. there are four sub-systems in the blending facility. as shown in figure 6, the functions of sub facility were a) to preheat ppo and the sample (indicated by a green line), b) to supply ppo from an hsd tank to a blending tank (indicated by a yellow line), c) to supply hsd from a hsd tank to a blending tank (indicated by a brown line) and d) to supply the sample from a buffer tank to the gas turbine (indicated by a red line). figure 5. blending facility figure 4. installing sampling holes i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 106 a bi-metal thermometer was mounted on both tanks to monitor a sample temperature in the blending tank and the buffer tank. a blend ratio of ppo and hsd was a volumetric ratio, which was measured by two units of turbine flowmeters, and installed at both supply pipes to the blending tank. a blend ratio of hsd and ppo was manually controlled by valve mounted on both turbine flowmeters. a flow rate of the sample to be supplied into the gas turbine was measured by the existing flowmeter installed at the inlet pipe supply. a mini boiler was used to heat the water to preheat ppo and the sample (ppo and hsd fuel blend) at the ppo tank and the blending tank, as well as the buffer tank. in this study, the specification of hsd and ppo were analyzed at the laboratory by using astm standards. the analyzed result was shown in table 3. table 4 showed a blended fuel ratio composition for each sample. the blended fuel used in this study must comply the astm 2880 “standards specification of gas turbine fuel oil” to minimize the effects of viscosity on a fuel atomization, a fuel evaporation including a fuel combustion, and also to guarantee the stability and safety of the gas turbine during the operation time, the blended fuel used in this study must comply with astm 2880 “standard specification of gas turbine fuel oil.” table 5 showed the classification of gas turbine fuel which divided into five grades. hsd fuel as the standard fuel of the gas turbine was classified into grade 2-gt. according to this classification, the kinematic viscosity of the sample must be between 1.9 4.1 cst. iii. result and discussion a. viscosity and spray angle test figure 7 showed the result of viscosity test. as shown in figure 7, the viscosity increases in line with the increasing of ppo ratio and decreases with the increase of temperature. the same result is also indicated by nozomu et al. [7], and sallevelt et al. [5]. they had measured the effect of the temperature rise table 3. characteristics of ppo and hsd fuel calorific value density viscosity kj/kg kg/m2 cst at 40 °c hsd 45.52 811 3.46 ppo 39.81 883 40.57 table 4. sample composition sample composition i hsd100% ii hsd95%-ppo5% iii hsd90%-ppo10% iv hsd80%-ppo15% figure 6. sub-facilities of blending facility ppo tank buffer tank blending tank water heater burner expansion tank water tank v-201 v-202 v-301 v-302 f t t v-103 f ppo pump ppo filter hsd filter hsd pump f v-304 v-401v-402 t v-101 v-102 water pump v-303 sample flowmeter ppo flowmeter hsd flowmeter gas turbine combustor hsd tank p p p p table 5. classification of gas turbine fuel characteristics unit grade no.0-gt no.1-gt no.2-gt no.3-gt no.4-gt flash point °c >= 38 >= 38 >= 55 >= 55 kinetic viscosity cst 1.3 2.4 1.9 4.1 = 5.5 = 5.5 carbon residue % <= 0.15 <= 0.15 <= 0.35 ash content % <= 0.01 <= 0.01 <= 0.01 <= 0.03 water and sediment % <= 0.05 '<= 0.05 <= 0.05 i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 107 on kinematic viscosity of biofuel, which derived from a palm methyl ester and a vegetable oil, respectively. as shown in figure 7, at the ambient temperature, and the viscosity of sample ii, iii, and iv exceed the grade 2-gt with the range of 1.9 4.1 cst. therefore, these sample were impossible to comply the classification of grade 2-gt without pre-heating. table 6 showed the result of the spray angle test. the preheat sample was injected to the nozzle, when the spray angle of the sample was already the same with the standard angle, then the temperature sample was recorded. as an addition, by using figure 7, a kinematic viscosity of each sample was estimated. as shown in table 6, the estimated viscosity located in the range of grade no.2-gt. figure 8 showed the spray angle measurement condition for the sample i and iv. through a glass viewing window, the spray angle was shown to be 60°. by using this experiment, it was proved that the high viscosity could be decreased by the increment of temperature, and a decrease in viscosity could keep the fuel atomization condition as indicated by the spray angle test. this result was also supported by the following previous studies concerning a nozzle spray angle in biofuel use [8], [9]. they had found that hightemperature fuel injection reduced the kinematic viscosity value of the biofuel and could improve the biofuel spray atomization at a nozzle. b. gas turbine operating performance test after the viscosity test and the spray angle test were conducted in the laboratory, the gas turbine operating test was performed. the results were explained in figure 9 and table 7. figure 9 showed a power output profile of the gas turbine during the operation time for each sample. the fluctuation of power output was depending on the demand of the national grid at the operation time. there was no influence from an increase in ppo ratio. the average value of the gas turbine operating performance was shown in table 7. the gas turbine and the generator speed were constant. however, the output and the frequency were fluctuated due to the demand fluctuation at that time. an increase of ppo ratio did not give any effects on both of turbine speed and generator speed. table 8 showed the fuel blend/sample specification. the calorific value of sample was decreased in an increase of ppo ratio. however, the kinematic viscosity, the relative density, as well as the fuel flow rate were increased. figure 10 showed the fluctuation table 6. spray angle measurement sample hsd vol. ppo vol. temp. test viscousity press. test spray angle (ltr) (ltr) (°c) cst mpa (°) i 50 0 36 4.00 1.034 60 ii 47.5 2.5 40 4.10 1.034 60 iii 47.5 5.3 45 4.10 1.034 60 iv 47.5 11.9 55 4.10 1.034 60 figure 7. effect of an increase in temperature on a sample viscosity figure 8. spray angle of sample i and sample iv i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 108 profile of specified fuel consumption (sfc) for each sample. the profile fluctuation of each sample was relatively stable, except for sample i. sample i showed several excessive fluctuations due to load fluctuations. in general, sfc value of sample i was located at the lowest value because it has the highest calorific value. as shown in table 9, an average of sfc was increased with the increasing of ppo ratio. the increase in sfc was caused by a decrease in calorific value of the samples. the sample flow rate was increased automatically to maintain the gas turbine output. chiramonti et al. [3] and szalay et al. [10] studies showed a lower calorific value and obtained an increase in a flow rate supply of fuel blend by using a blend of diesel and biofuel. figure 11 showed a vibration velocity profile measured at the generator and the compressor of the gas turbine. as shown in figure 11, the vibration velocity at point 1 was located at the highest range of 0.76 0.99 cm/s and followed by the vibration velocity at point 2, which located in the range of 0.480.74 cm/s. the vibration velocity was wider at point 3, with a range of 0.53 1.14 cm/s and at point 4 with a range of 0.21 1.02 cm/s, respectively. the average vibration velocity at point 1 was the highest, and the range of vibration velocity at point 4 was the widest. the vibration velocity profile at the point 1 and 2 were relatively stable. however, the excessive fluctuation was seen at the point 3 and 4, especially for sample iv. since a combustion and a fuel atomization of the gas turbine system was designed to be used for the sample i. as shown in figure 10, the vibration velocity profile of sample i was in general appears to be the most stable and located at the lowest level at all measurement points. it can be predicted that a mixing of sample i with a combustion air was in an optimal combustion condition. table 9. average sfc sample i ii iii iv sfc (ltr/kwh) 0.428 0.433 0.442 0.446 figure 9. power output figure 10. sfc profile table 7. gas turbine performance gas turbine performance unit sample i sample ii sample iii sample iv output mw 16.75 16.56 16.92 17.06 frequency hz 50.1 50.13 50.18 50.18 turbine speed rpm 5,100 5,100 5,100 5,100 generator speed rpm 3,000 3,000 3,000 3,000 table 8. sample specification fuel blend specification unit sample i sample ii sample iii sample iv caloric value kkal/kg 10,879 10,811 10,743 10,606 kinematic viscosity cst 3.46 4.34 5.14 5.01 relative density kg/m3 811 836 837 837.5 i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 109 the vibration at point 1 was induced by a rotating part vibration, while other vibrations induced by other mechanisms. the oscillations were known induced by the combustion. the effect of an increase in ppo ratio was represented by the combustion-induced oscillations. as explained by othman et al., the heated flow in the combustor was resulted in a higher vibration level, since the temperature had induced the higher turbulence intensity in a heated flowing medium. othman et al. also showed the effects of fuel kind on induced vibration in a gas turbine, and a combustion-driven oscillation tends to increase with c/h ratio [11]. ppo had a carbon/hydrogen (c/h) rate higher than hsd, as a consequence, an increase in ppo ratio might generate an accumulation of soot inside the combustion chamber or turbine blades [12]. the velocity vibration at point 2 decreased due to the measurement location that had a distance from the rotating part as the main vibration source. the measurement point was in the compressor body. the vibration velocity at point 3 and 4 were induced by the same kind vibration resources of at point i. however, the rotating parts were the generator shaft with a speed of 3,000 rpm, which lower than a speed of the gas turbine compressor of 5,100 rpm. this lower speed induced a wider vibration velocity at point 3 and point 4 as shown in table 10. table 10 showed an average vibration at the four locations of measurement point for each sample. the effect of an increase in ppo ratio on the vibration velocity was readily apparent at point 3 and 4, which induced by rotating part with speed of 3,000 rpm. however, in the higher rotating part speed of 5,100, the effect was not shown explicitly at point 1. the highest average vibration velocity was shown by sample iv. at the point 4, the average velocity was the lowest value except for sample iv. figure 11. vibration velocity profile table 10. average vibration fuel average vibration (cm/sec) point 1 point 2 point 3 point 4 sample i 0.89 0.66 0.64 0.23 sample ii 0.86 0.64 0.79 0.38 sample iii 0.89 0.64 0.74 0.33 sample iv 0.86 0.69 0.94 0.69 [ i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 110 the maximum increase of vibration velocity was still below the threshold value for the vibration velocity of 2.03 cm/sec, which the threshold value was set at 1.27 cm/sec. according to the safety standard for gas turbine operation, it should be wary of the impact of an increase in vibration on the shaft of the compressor and the generator. figure 12 showed ten chambers of combustion installed circumferentially. the nozzle was mounted inside each the combustor chamber. figure 13 showed the fluctuation profile of pressures at nozzle 1, 3, 5, 7, and 9 for each sample. these nozzle pressure profiles were considered to be represented others nozzle figure 12. combustor chambers [6] figure 13. nozzle pressure profile i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 111 figure 14. average value of nozzle pressure pressure profile. therefore, the other profiles were not shown in this paper. as shown in figure 13, compared to the other nozzle pressure profile, the nozzle pressure profile of sample i indicated the lowest value at all nozzle for each sample. a pressure nozzle affected to fuel atomization condition, therefore, a higher-pressure nozzle indicated high pressurized atomization. in this study, the fuel atomization condition at nozzle in a combustor chamber was not observed. however, the effect of the nozzle on the fuel atomization could be predicted based on the following studies. nozomu et al. showed that an increase in the nozzle pressure had influences on a decrease in sauter mean diameter (smd) and an increase in nox emission level [7]. as an addition, the effect of nozzle pressure on smd was expressed by the equation proposed by ee sann tan et al. [13]. figure 14 showed an average of nozzle pressure at all nozzles for each sample. the sample i was usually at the lowest value for all samples at all nozzles. in general, an increase in ppo ratio caused an increase in the average value of nozzle pressure. figure 15 showed a condition of nozzle 1 after used sample i (left side) and sample iii (right side). according to the visual observation, deposit at nozzle i was found with various thickness and attachment conditions. for all sample, the deposit was black and brittle. the deposit was formed at the nozzle due to the incomplete combustion, whereas, the formation velocity of deposit was depended on the fuel characteristics. the deposit amount of sample iii exceeded the deposit amount of sample i. this result was supported by the argument of gökalp et al. concerning an increase in ppo ratio that might generate an accumulation of soot inside the combustion chamber or turbine blades [13]. in this study, according to the visual observation, it was concluded that the amount of deposit increases with an increase in ppo ratio. the formed deposit at the nozzle induced the nozzle pressure. the nozzle pressure increased due to the formed deposit at nozzle that was a possibility to cover the nozzle holes. it was known that the carbon content in sample i was higher than sample iii, then the more carbon content in fuel molecule, the more likely it to produce soot [14]. in this study, conversely, since the a/f ratio was fixed, there was no balance adjustment of a combustion air flow rate to an increase in fuel flow rate supply (an increase in sfc). it leads an incomplete combustion and generates soot. nozomu et al. showed that an increase in o2 (a combustion air) supply would decrease the soot [7]. deposit amount in the nozzle was related to an increase in ppo ratio and the fix of a/f ratio. deposit at nozzle might cause a difficulty in a releasing nozzle. this condition will potentially change a nozzle maintenance interval. based on the deposit observation result at the nozzles, it should be a possibility that deposit was also attached to turbine blades and duct surface. the increase of nozzle pressure as shown in figure 13 could predict a result of the deposit formed in the nozzles. the deposit was formed due to incomplete combustion since no adjustment of the a/f ratio. increasing in ppo ratio required more o2 to combust the sample containing ppo, completely. although ppo contained o2, it is unlike enough to combust it completely. figure 15. deposit at no 1 nozzle, after used sample i (left side) and sample iii (right side) i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 112 table 11 flue gas (mg/m3) emission sample i sample ii sample iii sample iv average 15% o2 average 15% o2 average 15% o2 average 15% o2 co 0 0 0 0 18.5 25.9 2,5 3.5 nox 65.7 87.2 94.3 133.2 235 332 222 310 so2 84 165 16.2 11.5 60 84 49 69 o2 16.9 15 16.8 15 16.5 15 16,7 15 table 12. flue gas temperature sample i sample ii sample iii sample iv temperature (°c) 459.1 464.9 478.7 478.8 flue gas emission was used as indicators combustion performance evaluation. table 11 indicated flue gas content, which consists of carbon monoxide (co), nitrogen oxide (nox), sulphur (so2) and oxygen (o2) emission level. the correction value used 15% of oxygen was also shown. the flue gas was formed by a combustion process, in which the composition of flue gas depends on a kind of fuel and a combustion condition, such as a/f ratio, fuel atomization condition. the flue gas level for each sample was below the threshold value stipulated by ministerial decree of environment and forestry, no.21 of 2008, which the threshold value of nox = 450 mg/nm3, and sox = 650 mg/nm3, respectively. as shown in table 11, co increased for sample iii and iv. using svo from rapeseed, sunflower and soybean, cavarzere et al. presented that co emission level from svo fuel blend ratio up to 20% was almost same with the co emission from pure diesel. beyond 20% of svo fuel blend ratio, the co emission was known higher than the emission from pure diesel [2]. a lower co indicated a good combustion characteristics and a complete combustion occurred or it close to the stoichiometric conditions. the factors affected co emission level were a/f ratio, engine speed, injection time, atomization rate and kind of fuel [15], [16]. in this study, co emission increased as a result of the ppo ratio increment, since the combustion system was designed for diesel fuel. this situation was also found in cavarzere et al. study [3]. the increase in co level was resulted from a decrease in a/f ratio and a calorific value of the sample. the a/f ratio of the gas turbine was the specified ratio value for sample i. as a consequence for others sample used, the a/f ratio should be adjusted due to an increase of sample flow rate. however, since a/f ratio was fixed, the co emission level increased due to insufficient air for combustion. this result was supported by nozomu et al. [7], who used biofuel blend as fuel in a gas turbine. co emission level can be decreased by an increase in a/f ratio [7]. a decrease in the calorific value of sample iii and iv caused an increase in fuel flow rate and also causes combustion condition moves to rich mixture condition (a decrease in a/f ratio). table 11 showed nox level that increased with an increase in ppo ratio, except for sample iv. the increase of nox caused by several factors which can be explained by several hypotheses proposed by lapuerta et al. [17] and cheng et al. [18], such as: (i) at combustion phase, a flame of ppo with a cetane number of 62 ignited faster compared to flame of hsd with cetane number of 45. therefore, the combustion result of ppo had a longer residence time which caused an increase in thermal nox emission level [18], [19]. (ii) at pre-mixed burn fraction, ppo contains high oxygen which was resulted in a rise of nox [20]. (iii) ppo had a higher adiabatic ignition flame than hsd. therefore, it produced more nox. as shown in table 11 and table 12, nox level and flue gas temperature increased with the increasing of ppo ratio. hence, as indicated in both the tables, the effects that generated due to hypotheses (i) (iii) were dominant in the combustion system. as shown in table 11, so2 emission level did not show a relation with an increase in ppo ratio. the so2 emission level depended on the sulphur content in the sample [20]. based on the laboratory analysis result which measured according to astm d 2622-03, it was indicated that sulphur content (% wt) in hsd and ppo were 0.22% and 0.03%, respectively. it can be understood that a level emission of so2 in sample i was higher than others sample. the effect due to an increase in ppo ratio to o2 emission level was not shown. figure 16 showed flue gas temperature profile during the experiment for each sample. red line indicated tmax. in general, the flue gas temperature of sample i was lower, and sample iv was higher compared to others. the flue gas temperature for sample ii and iii was fluctuated. in general, the flue gas temperature for sample ii was lower compared to the temperature of sample iii, both fluctuated each other. flue gas temperature had a close relation with a temperature in the combustion chamber and a nox emission level. table 12 showed an average of flue gas temperature, taverage. taverage increases with an increase in ppo ratio for each sample. an increase in taverage was caused by an increase in temperature of the gas turbine combustor, which was indicated by an increase in nox emission level as shown in table 12. an increase in taverage was still below the flue gas i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 113 temperature threshold of the gas turbine, tmax = 490°c. however, the increase in flue gas temperature should be supervised concerning of the operational safety standards of the gas turbine. table 13 showed an average of noise level at the turbine and the generator. the noise level was tended to increase with an increase in ppo ratio. however, it was shown a decrease in sample iv. the maximum noise level occurred at the turbine for sample iii. the decrease in noise level for sample iv was resulted by the decrease of the vibration for sample iv. it can be predicted that in this case, the noise source was mainly induced by a mechanical vibration of equipment due to the combustion vibration in the combustors, and others vibration and oscillation induced by the combustion vibration. the threshold value of noise was 120 db, respectively. iv. conclusion based on the standard operation of the gas turbine, the use of fuel blend with ppo ratio of 20% was the maximum blend ratio in this study. by using this ratio, the maximum temperature of flue gas, the noise level, and the velocity vibration which achieved in this study were 478.8°c (97.7% of the threshold value), 100.29 db (83.6% of the threshold value), 0.86 cm/sec (67.7% of the threshold value), respectively. they were almost close to the threshold value of 490°c, 120 db, and 1.27 cm/sec, respectively. an adjustment of a/f ratio to a certain kind of fuel blend was required to improve the combustion condition and to increase of combustion efficiency. the generated soot at the nozzles due to use of a higher ppo blended ratio and an adjustment of a/f ratio to certain kind of fuel will be an object for the next study before the hsd-ppo fuel blend implemented widely as the obligation for power generation company. acknowledgement acknowledgments are granted to pt pln wilayah padang, the gas turbine investigation team of bpptptpse and other persons who assist and support to complete this study for six months. references [1] bpp teknologi, refleksi tahun 2013, melalui teknologi kita tingkatkan daya saing dan ciptakan ketahanan nasional, jakarta, 23 desember 2013, [online] available: http://repositori.bppt.go.id/index.php?action=download&dir=_ data%2fdownload%2fpidatotahunan&item=paparan+ refleksi+bppt+akhir+2013.pdf&order=name&srt=yes&lang =en. [2] a. cavarzere et al., “experimental analysis of a micro gas turbine fuelled with vegetable oils from energy crops,” energy proc., vol.45, pp. 91-100, 2014. [3] d. chiaramonti et al., “exhaust emissions from liquid fuel micro gas turbine fed with diesel oil, biodiesel and vegetable oil,” applied energy, vol.101, pp. 349–356, jan. 2013. [4] m. prussi et al, “straight vegetable oil use in micro gas turbines: system adaptation and testing,” applied energy, vol. 89, pp. 287-295, 2012. [5] j.l.h.p. sallevelt et al, “the impact of spray quality on the combustion of a viscous biofuel in a micro gas turbine,“applied energy, vol. 132, no.1, pp. 575-585, nov. 2014. [6] rrt sigma engineering, “evaluation of gas turbine performance improvement alternatives for indonesia power,” 2015, [online] available: http://www.powerphase.com/wpcontent/uploads/2015/06/rrt-sigma-indonesia-power.pdf [7] n. hashimoto et al., “fundamental combustion characteristics of palm methyl ester as alternative fuel for gas turbines”, fuel, vol. 87, pp.3373-3378, 2008. [8] i.k.g. wirawan et al., “pengaruh temperatur pemanasan awal tipe straight pada minyak kelapa terhadap sudut semprot nosel”, proceeding seminar nasional tahunan teknik mesin xiv (snttm xiv), banjarmasin, 7-8 oktober 2015, ke-30. figure 16. profile of flue gas temperature table 13. noise level fuel noise level (db) turbine generator sample i 97.14 95.16 sample ii 98.91 95.67 sample iii 100.29 96.39 sample iv 99.21 91.09 http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en http://repositori.bppt.go.id/index.php?action=download&dir=_data%2fdownload%2fpidatotahunan&item=paparan+refleksi+bppt+akhir+2013.pdf&order=name&srt=yes%e2%8c%a9=en https://doi.org/10.1016/j.egypro.2014.01.011 https://doi.org/10.1016/j.egypro.2014.01.011 https://doi.org/10.1016/j.egypro.2014.01.011 https://doi.org/10.1016/j.apenergy.2012.01.066 https://doi.org/10.1016/j.apenergy.2012.01.066 https://doi.org/10.1016/j.apenergy.2012.01.066 https://doi.org/10.1016/j.apenergy.2011.07.031 https://doi.org/10.1016/j.apenergy.2011.07.031 https://doi.org/10.1016/j.apenergy.2011.07.031 https://doi.org/10.1016/j.apenergy.2014.07.030 https://doi.org/10.1016/j.apenergy.2014.07.030 https://doi.org/10.1016/j.apenergy.2014.07.030 https://doi.org/10.1016/j.apenergy.2014.07.030 http://www.powerphase.com/wp-content/uploads/2015/06/rrt-sigma-indonesia-power.pdf http://www.powerphase.com/wp-content/uploads/2015/06/rrt-sigma-indonesia-power.pdf http://www.powerphase.com/wp-content/uploads/2015/06/rrt-sigma-indonesia-power.pdf http://www.powerphase.com/wp-content/uploads/2015/06/rrt-sigma-indonesia-power.pdf https://doi.org/10.1016/j.fuel.2008.06.005 https://doi.org/10.1016/j.fuel.2008.06.005 https://doi.org/10.1016/j.fuel.2008.06.005 http://eprints.ulm.ac.id/610/1/ke-30.pdf http://eprints.ulm.ac.id/610/1/ke-30.pdf http://eprints.ulm.ac.id/610/1/ke-30.pdf http://eprints.ulm.ac.id/610/1/ke-30.pdf http://eprints.ulm.ac.id/610/1/ke-30.pdf i. febijanto / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 103–114 114 [9] a. adam et al.,” analysis of straight vegetable oil (svo) spray characteristics at end of injection (eoi),” journal of medical and bioengineering (jomb), vol.1, no. 1, pp.59-62, 2012. [10] d. szalay et al., using biodiesel fuel for gas turbine combustors, appl. agric-forestry res., vol. 2, no. 65, pp. 6576, 2015. [11] m. othman et al., “fuel effect on induced vibration in gas turbine engines,” fuel, vol. 67, pp. 321-326, 1988. [12] i. gökalp, e. lebass, ”alternative fuels for industrial gas turbines (aftur)”, applied thermal engineering, vol. 24, 2014. [13] e.s. tan, et al., “biodiesel for gas turbine application-an atomization characteristics study”, intech, pp. 213-243, 2013. [14] p.k. devan et al., ”performance, emission and combustion characteristics of poon oil and its diesel blends in a di diesel engine,” fuel , vol.88, no. 86, pp. 1–7, 2009. [15] m. mofijur et al.,”comparative evaluation of performance and emission characteristics of moringa oleifera, and palm oil based biodiesel in a diesel engine,” industrial crops and products, vol.53, pp. 78–84, 2014. [16] m. gumus et al., “the impact of fuel injection pressure on the exhaust emissions of a direct injection diesel engine fueled with biodiesel-diesel fuel blends,” fuel, vol.95, pp. 486-494, 2012. [17] m. lapuerta et al., "effect of biodiesel fuels on diesel engine emissions," progress in energy and combustion science, vol. 34, pp. 198-223, 2008. [18] a.s. cheng et al.,"investigation of the impact of biodiesel fuelling on nox emissions using an optical direct injection diesel engine," international journal of engine research, vol.7, pp. 297318, 2006. [19] k. sivaramakrishnan and p. ravikumar, “determination of cetane number of biodiesel and it’s influence on physical properties,” arpn journal of engineering and applied sciences, vol.7, no.2, pp.205-211, 2012. [20] n. a. rahim et al., “effect on particulate and gas emission by combusting biodiesel blend fuels made from different plant oil feedstocks in a liquid fuel burner,” energies, vol. 9, pp. 1-18, 2016. https://doi.org/10.12720/jomb.1.1.59-62 https://doi.org/10.12720/jomb.1.1.59-62 https://doi.org/10.12720/jomb.1.1.59-62 https://doi.org/10.12720/jomb.1.1.59-62 https://doi.org/10.3220/lbf1443169529000 https://doi.org/10.3220/lbf1443169529000 https://doi.org/10.3220/lbf1443169529000 https://doi.org/10.1016/0016-2361(88)90313-4 https://doi.org/10.1016/0016-2361(88)90313-4 https://doi.org/10.1016/j.applthermaleng.2003.10.035 https://doi.org/10.1016/j.applthermaleng.2003.10.035 https://doi.org/10.1016/j.applthermaleng.2003.10.035 https://doi.org/10.5772/54154 https://doi.org/10.5772/54154 https://doi.org/10.5772/54154 https://doi.org/10.1016/j.fuel.2008.11.005 https://doi.org/10.1016/j.fuel.2008.11.005 https://doi.org/10.1016/j.fuel.2008.11.005 https://doi.org/10.1016/j.indcrop.2013.12.011 https://doi.org/10.1016/j.indcrop.2013.12.011 https://doi.org/10.1016/j.indcrop.2013.12.011 https://doi.org/10.1016/j.indcrop.2013.12.011 https://doi.org/10.1016/j.fuel.2011.11.020 https://doi.org/10.1016/j.fuel.2011.11.020 https://doi.org/10.1016/j.fuel.2011.11.020 https://doi.org/10.1016/j.fuel.2011.11.020 https://doi.org/10.1016/j.pecs.2007.07.001 https://doi.org/10.1016/j.pecs.2007.07.001 https://doi.org/10.1016/j.pecs.2007.07.001 https://doi.org/10.1243/14680874jer05005 https://doi.org/10.1243/14680874jer05005 https://doi.org/10.1243/14680874jer05005 https://doi.org/10.1243/14680874jer05005 http://www.arpnjournals.com/jeas/research_papers/rp_2012/jeas_0212_640.pdf http://www.arpnjournals.com/jeas/research_papers/rp_2012/jeas_0212_640.pdf http://www.arpnjournals.com/jeas/research_papers/rp_2012/jeas_0212_640.pdf http://www.arpnjournals.com/jeas/research_papers/rp_2012/jeas_0212_640.pdf http://dx.doi.org/10.3390/en9080659 http://dx.doi.org/10.3390/en9080659 http://dx.doi.org/10.3390/en9080659 http://dx.doi.org/10.3390/en9080659 mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.73-80 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. enhancement of motionability based on segregation of states for holonomic soccer robot gunawan dewantoro*, anton suprayudi, daniel santoso faculty of electronics and computer engineering, satya wacana christian university jl. diponegoro 52-60, salatiga 50711, indonesia received 21 july 2018; received in revised form 28 october 2018; accepted 29 october 2018 published online 30 december 2018 abstract one of the critical issues when navigating a wheeled robot is the ability to move effectively. omnidirectional robots might overcome these nonholonomic constraints. however, the motion planning and travel speed of the movement has been in continuous research. this study proposed segregation of states to improve the holonomic motion system with omnidirectional wheels, which is specially designed for soccer robots. the system used five separate defined states in order to move toward all directions by means of speed variations of each wheel, yielding both linear and curved trajectories. the controller received some parameter values from the main controller to generate robot motion according to the game algorithm. the results show that the robot is able to move in an omnidirectional way with the maximum linear speed of 3.2 m/s. the average error of movement direction is 4.3°, and the average error of facing direction is 4.8°. the shortest average time for a robot to make a rotational motion is 2.84 seconds without any displacement from the pivot point. also, the robot can dribble the ball forward and backward successfully. in addition, the robot can change its facing direction while carrying the ball with a ball shift of less than 15 cm for 5 seconds. the results show that state segregations improve the robots capability to conduct many variations of motions, while the ball-handling system is helpful to prevent the ball get disengaged from the robot grip so the robot can dribble accordingly. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: holonomic motion; omnidirectional robot; soccer robot; ball-handling. i. introduction the popularity of soccer robot contests has been emerging in the last decades. it came with various divisions, namely: kids league, small size league, medium size league, etc. one of the vital aspects in conducting the game is regarding the robot motion mechanisms. some literature has addressed similar issues, such as in [1][2], which proposed a ballhandling mechanism while freely moving. matlab was used to simulate the control system. on the other hand, some conventional locomotion systems are still evolving. a two-wheeled robot was controlled using a pid controller to vary the velocity of the left and right wheels [3]. a genetic algorithm was utilized to optimize the pid parameters. also, pi controllers together with fuzzy systems were used in [4] to regulate the four-wheeled omnidirectional robot. the development of mechanical design has also become important to ensure motion flexibility. a spherical wheel for an omnidirectional mobile robot is proposed in [5][6]. the main purpose of such development is to address the drawback of fourwheeled robot design. in [7], two active wheels were employed to control the ball rotation. the mathematical foundations were critical to derive the kinematics between the ball rotation and the wheels. a comprehensive review of wheel types of omnidirectional robots was shown in [8][9]. two categories of omni-wheels, namely special omnidirectional wheels and conventional steerable wheels, were compared to show the pros and cons of each wheel type to be applied in omnidirectional wheeled mobile robots. in addition, a well-planned trajectory is also important to navigate the soccer robot [10]. even though various sophisticated algorithms have been proposed, the range of path planning problems has been continuously growing [11]. many * corresponding author. tel: +62 857 4343 8874 e-mail address: gunawan.dewantoro@staff.uksw.edu https://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.73-80 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.73-80&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 74 important issues have to be addressed in the path planning process such as the modeling of multiple optimal functions, dynamic environment, dynamic constraints, etc., which cause a heavy computational operation. the aim of this research is to develop a navigation system of the holonomic robot without computational burdens that typically occur in both on-line and off-line motion planning [10][11][12], which leads to shorter travel time. the motion controller would only require parameter values such as state, heading, speed, and handler from the main controller. those four parameters values will be used to obtain the speed value of each omnidirectional wheel, so it generates all of the desired robot motions. the trajectories are decomposed into five available states, which have been developed in robotics research center (r2c), satya wacana christian university since 2016. some experimental setups are employed to show the effectiveness of this method compared to other motion planning methods [10][11][12][13]. ii. materials and methods figure 1 shows the complete block diagram of the robot hardware system. the arduino receives four parameters: motion, heading, speed, and handler from the main controller to determine the motion profile of the robot. those four parameter values will be used to determine the speed and rotational direction of three major driving motors and two ball-handling motors so that the robot will move accordingly. in the major driver motor control, pid control system is used in order to harmonize the motor rotational speed with the desired speed. rotary encoder sensor is used to acquire the actual speed value of the major driving motor, which in turn, used as feedback to the pid control system. the specifications of electric motors and robot are given in table 1. the cad model of the robot and ball-handling system are shown in figure 2 and 3, respectively. two infrared sensors are used to detect whether the ball has been grasped by the ball handling system or not. these data will be utilized in the game algorithm by the main controller. one emergency switch is functioned to run and deactivate the motion of the robot which mounted on the top part of the robot so it can be easily reached. figure 1. block diagram of robot hardware system figure 2. the cad model of the robot figure 3. the cad model of the ball-handling system table 1. physical and electrical specifications specification electric motors robot dimension 0.125 m ×  0.045 m 0.8 m ×  0.51 m weight 0.8 kg 21 kg voltage 24 volts dc max. current 4 ampere power 60 watt speed 500 rpm (no load) torque 2.45 nm gearbox planetary gear encoder 7 ppr g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 75 a. states segregation the servomotors generate pan and tilt values of the robot head, which together with the compass value are used as parameters in the game algorithm (processed in the main controller) to determine which states should be executed. therefore, in order to perform the robots motion effectively, five states from state 0 to state 4 were developed. 1) state 0 state 0 is used to make the robot does not move or immobile. when the motion parameter is 0, all the major driving motors will be deactivated because the value of the speed set point on the pid system is 0 rpm. when the handler parameter is ‘1’, then the ball handling system will be active so that the robot can chase the ball. state 0 is used to make the robot stop while either carrying the ball or not. 2) state 1 state 1 is a type of motion where the robot can perform linear motion toward all directions while maintaining its facing direction. this motion is used by the robot when the robot locates itself on the pitch at the beginning of the game. to set the motion direction, heading parameters ranging from 0° to 360° were used. the speed of motion is set by using speed parameter with a speed scale of 0 rpm to 350 rpm. the value of handler is ‘1’ in order to activate the ball-handling system. the equations used to obtain the speed set point of each motor for state 1 are [13]: 𝑉𝑚𝐴 = 𝑣.cos⁡(150 − 𝐷𝐷𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛) (1) 𝑉𝑚𝐵 = 𝑣.cos⁡(30 − 𝐷𝐷𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛) (2) 𝑉𝑚𝐶 = 𝑣.cos⁡(270 − 𝐷𝐷𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛) (3) where 𝑉𝑚𝐴 is the speed of motor a, 𝑉𝑚𝐵 is the speed of motor b, 𝑉𝑚𝐶 is the speed of motor c, v is speed parameter, and 𝐷𝐷𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛 is the desired direction (°). after obtaining the set point value of each motor using equations (1) to (3), the pid system sets the pwm value so that the motor rotates according to the specified set point. 3) state 2 state 2 is a type of movement where the robot moves rotationally with respect to the center point of the robot body. this motion is used when the robot locates the ball position. in order to move the robot rotationally, all the major driving motors must rotate in the same direction with the same speed, so that the robot rotates with respect to the center point of the robot body. the heading parameters are used so that the rotation speed movement of the robot can be adjusted, e.g., 1° to 180o for the clockwise rotation and -1° to -180° for the counter clockwise rotation. the pwm value of the major driving motor for the slowest and fastest rotation motion is obtained by trial and error. the governing equation is: 𝑉𝑚 = (𝐻⁡–⁡hmin)⁡×⁡(𝑆𝑚𝑎𝑥⁡–⁡𝑆𝑚𝑖𝑛)⁡ (𝐻𝑚𝑎𝑥⁡–⁡𝐻𝑚𝑖𝑛)⁡ + 𝑆𝑚𝑖𝑛 (4) where vm is the pwm value of motor speed, h is the heading parameter, hmin is the minimum value of heading parameter, hmax is the maximum value of heading parameter, smin is the pwm value for slowest rotation, and the last, smax is the pwm value for fastest rotation. 4) state 3 state 3 is a type of motion that can be used to turn with an adjustable angle to chase the ball. the aim is that when chasing and taking the ball, the robot does not need to rotate until the ball position is right in front of the ball handling system, which only has a width of 14 cm. the heading parameter is used to set the angle of turning, ranging from 1° to 90° for turning right and -1° to -90° for turning left. to set the speed of motion, the speed parameter with a scale value of 0 rpm to 350 rpm speed is used. the equations used to obtain the value of set point speed of each motor for state 3 are:  for turning right, 𝑉𝑚𝐴 ⁡=⁡𝑆𝑃 (5) 𝑉𝑚𝐵 ⁡= (𝐻⁡−⁡hmin)⁡×⁡(𝑆𝑚𝑖𝑛⁡−⁡𝑆𝑝) (𝐻𝑚𝑎𝑥⁡−⁡𝐻𝑚𝑖𝑛⁡) + 𝑆𝑝 (6)  for turning left, 𝑉𝑚𝐴 ⁡= ((𝐻⁡−⁡hmin)⁡×⁡−1)×⁡(𝑆𝑚𝑖𝑛⁡−⁡𝑆𝑝) ((𝐻𝑚𝑎𝑥⁡−⁡𝐻𝑚𝑖𝑛)×−1) + 𝑆𝑝 (7) 𝑉𝑚𝐵 ⁡=⁡𝑆𝑝 (8) where h is the heading parameter (-90° ≤ heading ≤ 90°), sp is the speed parameter, smin is the minimum value of speed parameter, vma is the speed of motor a, vmb is the speed of motor b, hmin is the minimum value of the heading parameter, and hmax is the maximum value of the heading parameter. from equations (5), (6), (7), and (8), one can obtain the set point value of the speed of the major driving motor in rpm. the pid control system will adjust the pwm value of the major driving motor in order to rotate the motor in accordance with the specified set point. 5) state 4 state 4 is used when the robot is intended to change its facing direction to the goal post with or without the ball. unlike the state 2, the center point of the rotation is the ball which is held in the ball handling system. the aim of this motion is to ensure that the ball is kept in place when doing the rotational motion. it can be seen in figure 4 that in order to produce rotational motion to the right, motor b is off, and motor c rotates faster than motor a with the turning direction of motor a and c to the left. whereas for the rotational motion to the left can be seen in figure 5, motor a is off; then motor c rotates faster than motor b with the rotating direction of motor b and c to the right. in state 4, the ball handling system is always in active mode to keep the ball in place. if the speed of the ball-handling motor is too slow, the ball will easily loose; while if it is too fast, it will reduce the battery lifetime. g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 76 b. pid control of major driving motor the pid control system is used to set the pwm value of each major driving motor in order to accord its rotational speed with the specified set point [14]. this process is conducted by arduino 1 with the set point value obtained from the calculation of each type of motion. the feedback is in the form of speed value in rpm of each major driving motor that was processed by arduino 2. the pid algorithm is shown by the following equation: 𝑦(𝑡) =⁡𝐾𝑝 (𝑥(𝑡) + 1 𝑇𝑖 ∫ 𝑥(𝜏)𝑑𝜏 + 𝑡 0 ⁡𝑇𝑑 𝑑𝑥(𝑡) 𝑑𝑡 ) (9) where x(t) is the input of the pid controller, and y(t) is the output of the pid controller. to determine the coefficients kp, ti, td, trial and error method was used [15]. the desired response is not in the form of underdamped response, e.g., no overshoot. otherwise, the motor will rotate suddenly and the speed exceeds the set point value for some time. fast rotation of the wheel at the beginning of the motion will lead the wheels to slip resulting from the motion errors. c. ball-handling system the ball-handling system is used to catch and dribble the ball, and placed in the middle of the forepart of the robot with a width of 14 cm. it consists of two wheels motors that have a diameter of 3 cm, a width of 1.5 cm, and with a height of ±4/5 of the ball height. the ball-handling system works by rotating the active wheel to the inner direction of the robot. the right wheel rotates counter clockwise, and the left wheel rotates clockwise. thus, when there is a ball attached to the wheel, the ball will be automatically stuck into the ball-handling area as shown in figure 6 and 7. if the ball already gets into the ball-handling area, both of ball handling motors will decrease the rotational speed. the aim of reducing the speed of the ballhandling motor is to conserve battery life. the sensors that used to detect the ball in the ball handling area are the infrared sensors. iii. results and discussions a. pid control performance to obtain the desired control performance, some experiments are conducted to show the step responses using different pid parameters. it can be seen in figure 8, the response of the pid system of the major driving motor with the value of kp = 0.05, ki = 0, and kd = 0.01 is not an underdamped response. this result is in accordance with the expectation, which is no overshoot. b. motionabilty 1) state 0 the experimental results show that all of the motors can stop successfully. at the time the robot activates state 0 while dribbling the ball, the handler parameter value must be ‘1’ so that the ball handling system can hold the ball securely. the average time needed to make the robot stop from its maximum speed is 0.26 seconds. 2) state 1 state 1 test is conducted by running robot with some heading parameter value as far as ± 3 meters at 10 times of attempts, then observing the movement direction error and facing direction error. the results are shown in figure 9 and figure 10 are the results of experiments carried out by using the parameter value of 220 rpm speed. these values are used in the game algorithm to navigate on the pitch. from the experimental results conducted as many as 10 times for each heading value, the robot motion is not always constant. the average error of the robot motion direction is 4.3°, and the direction of the robot is 4.8°. a slight slip occurred on the major driver becomes the cause of motion direction errors in the robot. whereas, the error of the direction of the robot is likely because of the inertial force figure 4. the right rotation figure 5. the left rotation off b a c off a c b figure 6. ball-handling design (side view) figure 7. ball-handling design (top view) g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 77 exerted by the robot when suddenly stopped. the center of gravity of robots that are not at the center point of the robot also affects the inertial force felt by the robot so that it affected on the resulting movement. on the other hand, the maximum robot linear speed is 3.2 m/s when the speed parameter is set to 350 rpm. 3) state 2 test of state 2 is carried out by calculating the time to make a full rotation at some heading values. to test whether there is a shift at the center point of the rotational movement, a line is made on the field at the outside of the robot wheel followed by the observation whether there is a shift or not. table 2 shows that more positive or negative heading values lead to a shorter time required for the robot to perform a full rotation. this is because the heading parameter is used to set the robot's rotational speed. in addition to the observations made, there is no visible shift in the position of the wheels to the lines made. therefore, it can be concluded that there is no shift at the center point of robot rotational movement. the fastest average time from five times robot attempts to do one full rotation is 2.88 seconds for right rotation and 2.92 seconds for left rotation. 4) state 3 in the game algorithm, this state is used to chase and take the ball as long as the robot can see the ball, with the ball position is not more than 18 cm to the right or to the left of the center point of the robot forepart. the test is done by placing the ball on the left or right side figure 8. the response of pid system 0 50 100 150 200 250 300 350 400 1 4 7 1 0 1 3 1 6 1 9 2 2 2 5 2 8 3 1 3 4 3 7 4 0 4 3 4 6 4 9 5 2 5 5 5 8 6 1 6 4 6 7 7 0 7 3 7 6 7 9 8 2 8 5 8 8 9 1 9 4 9 7 1 0 0 m o to r s p e e d ( rp m ) time (ms) kp= 0,04 : ki= 0 : kd= 0 kp= 0,05 : ki= 0 : kd= 0 kp= 0,05 : ki= 0 : kd= 0,01 kp= 0,06 : ki= 0 : kd= 0,01 figure 9. the average error of motion direction 2.1 1 3.7 0.8 2.7 4.3 0.8 2.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 45 90 135 180 225 270 315 t h e e rr o r o f m o ti o n d ir e ct io n ( °) heading value (°) table 2. physical and electrical specifications heading (°) the average time for the right rotation (s) the average time for the left rotation (s) 30 8.46 8.24 60 5.96 5.98 90 4.70 4.78 120 3.84 3.96 150 3.32 3.36 180 2.84 2.92 g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 78 of the robot as far as 5 cm and 18 cm from the center point of the robot forepart whereas the ball distance in front of the robot is varied from 15 cm to 300 cm. in overall, the success rate of state 3 to chase and catch the ball at a front distance of more than 15 cm is 100%. however, at a front distance of no more than 15 cm and the distance of the left or right side of the robot is 18 cm, is ending with an unsuccessful result. this is because the ball position is still too close to the forepart of the robot, so the ball hit the front side of the robot, which is not part of the ball-handling system. 5) state 4 test of state 4 is carried out by making a circle line with a diameter of 15 cm on the field; then motions run for 5 seconds for both left and right rotation. each test is done as many as 10 times with the position of the ball center point inside the circle line. it is then observed whether the ball center point is out of the circle line or not while and after rotating. ten times experimental results for left and right rotation had shown 100% successful operations. the slight movement of the ball position can be caused by the value of the major driver speed that has not been precise, so the center of the robot’s rotational movement is not at the center point of the ball. overall, this motion can be used to change the facing direction of the robot when carrying the ball. c. dribbling test the dribbling test is carried out by using different motions, e.g., state 3 with heading 0° for forwarding dribble, and state 1 with heading 180° for the backward dribble. the value of the speed parameter is 220 rpm in accordance with that is used in the game algorithm. the test is conducted by carrying 10 times of attempts to dribble forward and backward and then observed whether the ball is detached from the robot while moving or stopping. from the 10 times of attempts conducted, the robot can dribble the ball forward and backward with a success rate of 100%. iv. conclusion the use of state segregations for three omniwheeled robots is suitable because of the capability to conduct many variations of motions. this segregation requires neither online nor offline path planning and gives relatively fast linear speed at 3.2 m/s. the results show that the robot is able to move in an omnidirectional way with the average error of the robot movement direction is 4.3°, and the average error facing the direction of the robot is 4.8°. the fastest average time for a robot to make a rotational motion is 2.84 seconds without any displacement from the pivot point. these results outperform the aforementioned motion planning methods in terms of time consumed when the robot moves along linear and curved trajectories. the robot can dribble the ball forward and backward successfully. the robot can change its facing direction while carrying the ball with a ball shift of less than 15 cm for 5 seconds. the ball-handling system is helpful to prevent the ball get disengaged from the robot grip so the robot can dribble accordingly. slip on the main driver wheels might create inaccuracies of robot movement. acknowledgement the authors would like to express sincere gratitude to satya wacana christian university for the supports and making this research possible. references [1] s. chikushi, t. weerakoon, k. ishii, t. sonoda, “motion analysis and control of the ball operation for dribbling action in robocup soccer robot,” in proceeding of international conference on soft computing and intelligent systems, japan, 2016. [2] r.p.m. chan, k.a. stol, c.r. halkyard, “review of modeling and control of two-wheeled robots,” annual reviews in control, vol. 37, no. 1, pp. 89-103, 2013. [3] z. jian, “control improvement of soccer robot motion based on genetic algorithm,” romanian review precision mechanics, optics & mechatronics, vol. 50, pp. 281-285, 2016. figure 10. the average error of facing direction 1.5 4.8 2.5 3 3.1 1.8 1.7 2 0 1 2 3 4 5 6 0 45 90 135 180 225 270 315 t h e e rr o r o f f a ci n g d ir e ct io n ( °) heading value (°) https://doi.org/10.1109/scis-isis.2016.0117 https://doi.org/10.1109/scis-isis.2016.0117 https://doi.org/10.1109/scis-isis.2016.0117 https://doi.org/10.1109/scis-isis.2016.0117 https://doi.org/10.1109/scis-isis.2016.0117 https://doi.org/10.1016/j.arcontrol.2013.03.004 https://doi.org/10.1016/j.arcontrol.2013.03.004 https://doi.org/10.1016/j.arcontrol.2013.03.004 https://search.proquest.com/openview/2179f62ddbb4e831e6dc9ac5e2d80f38/1?pq-origsite=gscholar&cbl=2035039 https://search.proquest.com/openview/2179f62ddbb4e831e6dc9ac5e2d80f38/1?pq-origsite=gscholar&cbl=2035039 https://search.proquest.com/openview/2179f62ddbb4e831e6dc9ac5e2d80f38/1?pq-origsite=gscholar&cbl=2035039 g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 79 [4] e. hashemi, m. g. jadidi, n. g. jadidi, “model-based pi–fuzzy control of four-wheeled omni-directional mobile robots,” robotics and autonomous systems, vol. 59, no. 11, pp. 930-942, november 2016. [5] k. tadakuma, r. tadakuma, j. berengeres, “development of holonomic omnidirectional vehicle with “omni-ball”: spherical wheels,” in proceeding of ieee/rsj international conference on intelligent robots and systems (iros), usa, 2007. [6] k. tadakuma, r. tadakuma, “mechanical design of "omniball": spherical wheel for holonomic omnidirectional motion,” in proceeding of ieee international conference on automation science and engineering (case), usa, 2007. [7] s. chikoshi, t. weerakoon, t. sonoda, k. ishii, “ball dribbling control for robocup soccer robot,” in proceeding of international conference on artificial life and robotics. (icarob), japan, 2017. [8] k. kanjanawanishkul, “omnidirectional wheeled mobile robots: wheel types and practical applications,” international journal of advanced mechatronic systems, vol. 6, no. 6, pp. 289-302, 2015. [9] a. s. al-ammri, i. ahmed, “control of omni-directional mobile robot motion,” al-khwarizmi engineering journal, vol. 6, no. 4, pp. 1-9, 2010. [10] e. j. jung, b. j. yi, “motion planning algorithms of an omnidirectional mobile robot with active caster wheels,” intelligent service robotics, vol. 4, no. 3, pp. 167-180, 2011. [11] p. raja and s. pugazhenthi, “optimal path planning of mobile robots: a review,” international journal of physical sciences, vol. 7, no. 9, pp. 1314-1320, 2012. [12] y. liu, x. wu, j. zhu, and l. lew, “omni-directional mobile robot controller design by trajectory linearization,” in proceeding of american control conference, usa, 2003. [13] f. ribeiro, i. moutinho, p. silva, c. fraga, n. pereira, “three omni-directional wheels control on a mobile robot,” braga : universidade do minho, 2004. [14] g. dewantoro, “robust fine-tuned pid controller using taguchi method for regulating dc motor speed,” in proceeding of international conference on information technology and electrical engineering (icitee), thailand, 2015. [15] j. han, “from pid to active disturbance rejection control,” ieee transactions on industrial electronics, vol. 56, no. 3, pp. 900-906, 2009. [16] https://doi.org/10.1016/j.robot.2011.07.002 https://doi.org/10.1016/j.robot.2011.07.002 https://doi.org/10.1016/j.robot.2011.07.002 https://doi.org/10.1016/j.robot.2011.07.002 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://doi.org/10.1109/iros.2007.4399560 https://www.semanticscholar.org/paper/ball-dribbling-control-for-robocup-soccer-robot-ishii/74a97ee83d076c0915847a68eceb637d93ce523e https://www.semanticscholar.org/paper/ball-dribbling-control-for-robocup-soccer-robot-ishii/74a97ee83d076c0915847a68eceb637d93ce523e https://www.semanticscholar.org/paper/ball-dribbling-control-for-robocup-soccer-robot-ishii/74a97ee83d076c0915847a68eceb637d93ce523e https://www.semanticscholar.org/paper/ball-dribbling-control-for-robocup-soccer-robot-ishii/74a97ee83d076c0915847a68eceb637d93ce523e https://doi.org/10.1504/ijamechs.2015.074788 https://doi.org/10.1504/ijamechs.2015.074788 https://doi.org/10.1504/ijamechs.2015.074788 https://doi.org/10.1504/ijamechs.2015.074788 https://www.iasj.net/iasj?func=fulltext&aid=2195 https://www.iasj.net/iasj?func=fulltext&aid=2195 https://www.iasj.net/iasj?func=fulltext&aid=2195 https://doi.org/10.1007/s11370-011-0089-4 https://doi.org/10.1007/s11370-011-0089-4 https://doi.org/10.1007/s11370-011-0089-4 https://doi.org/10.5897/ijps11.1745 https://doi.org/10.5897/ijps11.1745 https://doi.org/10.5897/ijps11.1745 https://doi.org/10.1109/acc.2003.1244061 https://doi.org/10.1109/acc.2003.1244061 https://doi.org/10.1109/acc.2003.1244061 http://ukacc.group.shef.ac.uk/proceedings/control2004/papers/237.pdf http://ukacc.group.shef.ac.uk/proceedings/control2004/papers/237.pdf http://ukacc.group.shef.ac.uk/proceedings/control2004/papers/237.pdf https://doi.org/10.1109/iciteed.2015.7408936 https://doi.org/10.1109/iciteed.2015.7408936 https://doi.org/10.1109/iciteed.2015.7408936 https://doi.org/10.1109/iciteed.2015.7408936 https://doi.org/10.1109/tie.2008.2011621 https://doi.org/10.1109/tie.2008.2011621 https://doi.org/10.1109/tie.2008.2011621 g. dewantoro et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 73–80 80 this page is intentionally left blank mev j. mechatron. electr. power veh. technol. 06 (2015) 67-74 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.67-74 obstacle avoidance method for a group of humanoids inspired by social force model ali sadiyoko a, b, *, bambang riyanto trilaksono b, kusprasapta mutijarsa b, widyawardana adiprawita b amechatronics engineering department, universitas katolik parahyangan jl. ciumbuleuit no 94, bandung, indonesia bschool of electrical engineering & informatics, institut teknologi bandung jl. ganesha no 10, bandung, indonesia received 01 september 2015; received in revised form 11 october 2015; accepted 19 october 2015 published online 30 december 2015 abstract this paper presents a new formulation for obstacle and collision behavior on a group of humanoid robots that adopts walking behavior of pedestrian crowd. a pedestrian receives position information from the other pedestrians, calculate his movement and then continuing his objective. this capability is defined as socio-dynamic capability of a pedestrian. pedestrian’s walking behavior in a crowd is an example of a sociodynamics system and known as social force model (sfm). this research is trying to implement the avoidance terms in sfm into robot’s behavior. the aim of the integration of sfm into robot’s behavior is to increase robot’s ability to maintain its safety by avoiding the obstacles and collision with the other robots. the attractive feature of the proposed algorithm is the fact that the behavior of the humanoids will imitate the human’s behavior while avoiding the obstacle. the proposed algorithm combines formation control using consensus algorithm (ca) with collision and obstacle avoidance technique using sfm. simulation and experiment results show the effectiveness of the proposed algorithm. keywords: humanoid robots; formation control; obstacle avoidance; social force model; consensus algorithm. i. introduction this paper propose a new approach to solve obstacle avoidance problem on a group of humanoid robots by combining of consensus algorithm and sociodynamic approach. sociodynamics is a systematic approach to mathematical modeling in the social sciences. sociodynamics has been developed starting from interdisciplinary approach that attempts to model the dynamic behavior of the social system of stochastic and quasi-deterministic models into more structured physical-mathematical system. the term of socio-dynamic is introduced by weidlich, as quoted in [1]. the goal of this new approach is to make a group of humanoid robots can walk to desired position and still able to avoid obstacle while still maintaining their path to their desired position. the new approach is using social force model (sfm) approach to make robots able to avoid obstacle and collision. sfm itself is a pedestrian’s walking behavior dynamic mathematical model developed by helbing and molnar [2]. the implementation of human behavior in humanoid’s behavior is based on the premise that, in the next few years, a humanoid robot will be placed on the human environment. so, if a robot will be placed in a human environment/crowd, it must have some knowledge of human behavior and capable to imitate and calculate it into its behavior. by using the sfm, the robot’s walking behavior is expected to be able to imitate the behavior of pedestrians in a crowd. the social force captures the effect of the neighboring pedestrians and the environment on the movement of individuals in the crowd. helbing [2] used the sfm approach into collective model of social panic to simulate the behavior of an escape panic of a crowd. in this model, both * corresponding author. tel: +62-8562156807 e-mail: asadiyoko@yahoo.com/alfa51@unpar.ac.id http://dx.doi.org/10.14203/j.mev.2015.v6.67-74 a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 68 psychological and physical effects are considered in formulating the behavior of the crowd. since our research’s aim is implementing the obstacle/collision avoidance algorithm on a group of humanoid robots, a capable algorithm is needed to assemble the robots into a group. for this purpose, an algorithm called the consensus algorithm was used [3]. consensus algorithm (ca) is a distributed algorithm for multi-agent system to achieve an agreement on the information states of each agent. its implementation in the field of robotics today is very much developed. by using consensus algorithm, a robot group can perform various tasks together including formation control, attitude alignment, foraging, rendezvous and cooperative search. when multiple robots agree on the value of a variable of interest, they are said to have reached consensus. to achieve consensus there must be a shared variable of interest, called the information state, which represents an instantiation of the coordination variable for the team. for this research, the information states are robot’s position, the center and shape of a formation and the direction of motion. robots update the value of their information states based on the information states of their neighbors. the aim of consensus algorithm is to design an update law so that the information states of all the robots in the network converge to a common value [4]. this paper is organized as follows, the problem statement and formulation are described in section ii. the method and basic theory of sfm, ca for formation control, obstacle and collision avoidance techniques and stability analysis of the proposed algorithm, and system architecture are described in section iii. some simulation and experiment results are shown in section iv. finally, section v concludes this paper. ii. problem statements and formulation given is a formation composed of three robots with a known virtual center as illustrated in figure 1. in figure 1, r1, r2, r3, r4 stand for robot1, robot2, robot3, and robot4. a position variable 𝑟𝑖 = [𝑥𝑖,𝑦𝑖] 𝑇, 𝑟𝑖 𝑑 = [𝑥𝑖 𝑑,𝑦𝑖 𝑑] 𝑇 and 𝑟𝑜𝑏𝑠 = [𝑥𝑜𝑏𝑠,𝑦𝑜𝑏𝑠] 𝑇 represents, respectively, the i-th robot’s actual position, robot’s desired position and obstacle’s position. the variable 𝑟𝑗 𝑑 = [𝑥𝑗 𝑑,𝑦𝑗 𝑑] 𝑇 and 𝑟𝑗 = [𝑥𝑗,𝑦𝑗] 𝑇 represent the j-th robot’s actual and desired position, and 𝑟𝑗𝐹 𝑑 = [𝑥𝑗𝐹 𝑑 ,𝑦𝑗𝐹 𝑑 ] 𝑇 represents the desired deviation of the j-th robot relative to 𝐶𝐹, where: [ 𝑥𝑗 𝑑(𝑡) 𝑦𝑗 𝑑(𝑡) ] = [ 𝑥𝑐(𝑡) 𝑦𝑐(𝑡) ]+ [ 𝑐𝑜𝑠[𝜃𝑐(𝑡)] −𝑠𝑖𝑛[𝜃𝑐(𝑡)] 𝑠𝑖𝑛[𝜃𝑐(𝑡)] 𝑐𝑜𝑠[𝜃𝑐(𝑡)] ][ 𝑥𝑗𝐹 𝑑 (𝑡) 𝑦𝑗𝐹 𝑑 (𝑡) ] (1) 𝐶𝐹 is coordinate frame on position 𝑟𝑖, where the x-axis is coincide with the orientation of the robot. this coordinate frame transformation is illustrated in figure 2. since research is focused only on robots and group behavior, the dynamics of robots as a single integrator system were considered, which is given by: 𝑢𝑖 = �̇�𝑖 (2) where 𝑟𝑖 ≜ [𝑥𝑖,𝑦𝑖] 𝑇 and �̇�𝑖 denote the position and velocity of the i-th robot, and 𝑢𝑖 is the control input and 𝑟𝑖 𝑑 ≜ [𝑥𝑖 𝑑,𝑦𝑖 𝑑] 𝑇 as target or desired position of 𝑟𝑖 . the static obstacle is defined as 𝑟𝑜𝑏𝑠 ≜ [𝑥𝑜𝑏𝑠,𝑦𝑜𝑏𝑠] 𝑇 and 𝑅𝑠𝑎𝑓𝑒, respectively as the position of an obstacle and its radii. all robots are connected with a communication topology as describe with graph )( nnn evg  , where },...,1{ nvn  is the node set and nnn vve  is the edge set, representing robots and its communication links. the communication topology among robots is illustrated in figure 3. figure 1. a formation composed of three robots with a known virtual center & an obstacle figure 2. frame coordinate transformation from global into robot’s frame coordinate a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 69 given the initial configuration as shown in figure 1, the objective of the system are: • all robot can walk from an initial position to their desired position, in a certain formation. r1, r2, and r3 are placed on the left side, and r4 is placed on the right side of the experimental platform. a control input 𝑢𝑖 will make i-th robot walks from 𝑟𝑖 to 𝑟𝑖 𝑑 as 𝑡 → ∞. • all robots can avoid obstacle while they walk along the way to reach their desired destination. • for obstacle avoidance, collision and obstacle avoidance factor from sfm equation were used. by using the observation results of moussaïd et al. [5] as a comparison, the expected results of the experiment of this new algorithm will resemble the behavior as depicted in figure 4. figure 4 shows the results of computer simulations for the heuristic pedestrian model (solid lines) compared with experimental results (shaded lines) during simple avoidance maneuvers in a corridor. part (a) shows the average trajectory of a pedestrian passing a static obstacle in the middle of the corridor; and part (b) shows the average trajectory of a pedestrian passing another individual moving in the opposite direction. iii. method this section describes the method that is used to solve the problem, begin with the basic theory of sfm, ca for formation control, obstacle/collision avoidance techniques and stability analysis. a. social force model according to helbing et al. [2], the motion behavior of a pedestrian is determined by some factors, which are: (i) individual desired direction, (ii) some influences from other pedestrians, (iii) some influences from obstacles, walls or other objects, and (iv) influence of an attractive object. the general sfm equation can be written as: 𝐹𝑖(𝑡) = 𝐹𝑖 0(𝑣𝑖,𝑣𝑖 0𝑒𝑖) + ∑ 𝐹𝑖𝑗(𝑒𝑖,𝑟𝑖 −𝑗 𝑟𝑗) + ∑ 𝐹𝑖𝑂(𝑒𝑖,𝑟𝑖 − 𝑟𝑂 𝑖)𝑂 + ∑ 𝐹𝑖𝑂(𝑒𝑖,𝑟𝑖 − 𝑟𝑂 𝑖)𝑂 (3) the first term, 𝐹𝑖 0(𝑣𝑖,𝑣𝑖 0𝑒𝑖), in equation (3) represents pedestrian’s individual desired direction, where 𝑣𝑖, 𝑣𝑖 0 , and 𝑒𝑖 represents, respectively, actual speed, desired speed, and desired direction of pedestrian i. the second term, 𝐹𝑖𝑗(𝑒𝑖,𝑟𝑖 − 𝑟𝑗) represents the influence of other pedestrian to pedestrian i, where 𝑟𝑖 and 𝑟𝑗 represent position of pedestrian i and j. in particular, the pedestrian keeps a certain distance from other pedestrian and to avoid collision, depends on the desired speed (𝑣𝑖 0) and pedestrian density. a repulsive effect of other pedestrian j is denoted in this term. the third and fourth term represent, respectively, a repulsive effects of an obstacle 𝐹𝑖𝑂(𝑒𝑖,𝑟𝑖 − 𝑟𝑂 𝑖) and an attractive effect of an attractive object/person, 𝐹𝑖𝐴(𝑒𝑖, 𝑟𝑖 − 𝑟𝐴, 𝑡). pedestrians are sometimes attracted by other persons (friends, street artists, commercials, etc). since research focus on obstacle/collision avoidance behavior and formation control, the fourth term from equation (3) was excluded. so, by using this simplification and equation in [3], the avoidance behavior part of sfm is written as: ∑ 𝐹𝑖𝑗(𝑒𝑖,𝑟𝑖𝑗)𝑗 = 𝑤𝑑𝐶𝑑𝑒 0.5√(‖𝑟𝑖𝑗‖+‖𝑟𝑖𝑗−s‖) 2 −s2 (4) and ∑ 𝐹𝑖𝑂(𝑒𝑖,𝑟𝑖 − 𝑟𝑂 𝑖)𝑂 = 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠)/𝐵 (5) where 𝐵,𝐶𝑠,𝐶𝑑 are positive scalar, 𝑟𝑖𝑗 ≜ (r𝑖 − r𝑗) , 𝑠 is step distance of the robot and 𝑟𝑜𝑏𝑠is position of an obstacle. the repulsive effects of equations (4) and (5) only hold for situation that are perceived in the figure 3. communication topology from the virtual center to all robots in the system figure 4. comparison between simulations with experimental results of the heuristic pedestrian walking model during simple avoidance maneuvers in a corridor [6] a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 70 pedestrian’s field of view (fov, 2φ). in order to take this effect of perception into account, it need to introduce the direction dependent weights 𝑤𝑠 and 𝑤𝑑: 𝑤(𝑒,𝑓) ∶= { 1, if𝑒 ∙ 𝑓 ≥ ‖𝑓‖cosφ c, 𝑜𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒. (6) by replacing (4) and (5) into (3), sfm equation can be derived as: 𝐹𝑖(𝑡) = 𝐹𝑖 0(𝑣𝑖,𝑣𝑖 0𝑒𝑖) + ∑ 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠)/𝐵 𝑂 + ∑ 𝑤𝑑𝐶𝑑𝑒 0.5√(‖(r𝑖−r𝑗)‖+‖(r𝑖−r𝑗)−s‖) 2 −s2 𝑗 (7) comparing with the other obstacle/collision avoidance equations which were used in some algorithms [6-9], the use of fov in this algorithm will become a distinctive factor, with the others. in the experiment, the value of φ is set to 60°. the avoidance behavior of the robots should be acted differently. the first term of equation (7) is the formation control term which will maintain robot position on a formation or still keeping them in a group. this formation control term will be described in the next section. b. consensus algorithm for formation control consensus algorithm (ca) is a distributed control algorithm for multi-agent systems, which allow each agent in the system to achieve agreement with the other agents by sharing its information states. ca is a major method to solve many multi-agent cooperative control problems. currently, ca has been developed and used in many applications of multi-robot systems. this is because the algorithm is distributive, so that the control equation for the robot can be simpler than the centralized control method. a necessary condition to achieve consensus is the availability of a communication topology that allow the information states are shared to all member of the group. if a communication topology in a multi-robots system is established for all robots, then consensus will be achieved if and only if the topology has a spanning tree [4]. in the case of formation establishment and control, some information states are needed to be shared. in this paper, virtual structure (vs) approach to solve the formation control problems was used. using this approach, the entire formation is treated as a rigid body or single structure, and then, the control strategy is derived in three stages [3]: 1. stage 1: define the desired dynamics of the virtual leader/virtual center of a virtual structure. this stage is illustrated in figure 1. 2. stage 2: translate the motion of the virtual leader/virtual center into desired motion for each robot. this stage is also illustrated in figure 1. 3. stage 3: derive tracking controls for each robot. since the research used 4 robots, a triangle formation for the group of 3 robots (r1, r2, and r3) was defined. the 4th robot will be acted as dynamic obstacle. in the group, the information states are shared to all robots by using communication topology depicted in figure 3, while r4 received the position of the other robots and the obstacle. all information states (i.e. 𝑟𝑖,𝑟𝑗,𝑟𝑜𝑏𝑠 ) are provided by a visual localization module (vlm), which consists of a web camera and a pc. vlm uses visual odometry (vo) technique to obtain all robots and obstacle positions and then share it to all robots. by taking the capability of robots used in the experiment into account, vo is regarded as the most appropriate technique to apply in the experiment. the illustration of the experiment is depicted in figure 5. the algorithm of vo technique is depicted in figure 6. figure 5. illustration of the experiment figure 6. the algorithm of visual odometry technique a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 71 for stage 3 of the vs approach, ca equation for reference tracking was used, which can be written as in equation (8). all position states (𝑟𝑖,𝑟𝑗,𝑟𝑜𝑏𝑠) are obtained by using vo. 𝑢𝑖 = �̇�𝑖 𝑑 − 𝛼𝑖(𝑟𝑖 − 𝑟𝑖 𝑑) − ∑ 𝑎𝑖𝑗[(𝑟𝑖 − 𝑟𝑖 𝑑) −𝑛𝑗=1 (𝑟𝑗 − 𝑟𝑗 𝑑)] (8) where 𝛼𝑖 is a positive scalar, 𝑎𝑖𝑗 is the (𝑖, 𝑗) entry of adjacency matrix 𝐴𝑛 associated with communication topology 𝐺𝑛 and 𝑟𝑖 𝑑 = [𝑥𝑖 𝑑,𝑦𝑖 𝑑] 𝑇 is the i-th robot’s desired position. while, 𝑟𝑖 − 𝑟𝑖 𝑑 and 𝑟𝑗 − 𝑟𝑗 𝑑 represents respectively, distance between the i-th robot’s actual and desired position, the j-th robot’s actual and desired position. c. obstacle/collision avoidance technics to implement sfm into robot’s behavior, ca equation (8) was integrated into equation (7), so that equation (7) is expanded to equation (9). 𝑢𝑖 = �̇�𝑖 𝑑 − 𝛼𝑖(𝑟𝑖 − 𝑟𝑖 𝑑) − ∑ 𝑎𝑖𝑗[(𝑟𝑖 − 𝑟𝑖 𝑑) −𝑛𝑗=1 (𝑟𝑗 − 𝑟𝑗 𝑑)] + 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠)/𝐵 + 𝑤𝑑𝐶𝑑𝑒 0.5√(‖𝑟𝑖𝑗‖+‖(𝑟𝑖𝑗)−s‖) 2 −s2 (9) equation (9) is the final equation to be implemented into humanoids robot. the obstacle and collision avoidance force are respectively presented by the fourth and fifth term of equation (9). the stability analysis of this algorithm is derived by using lyapunov’s stability analysis and will be explained in the next subsection. to implement equation (9) to robot, it need 2 more processes, which are: frame coordinate transformation and limitation process of the robot’s steps and orientation. since robot nao has some limitation on its moves, the research try to imitate pedestrian’s walking behavior that is tend to be a non-holonomic behavior, treat and reprogram nao as a non-holonomic robot. to make a leg movement on nao, control input given by equation (9) must not exceed robot’s maximum foot step parameters, which are 0.08 m to step forward (x-axis) and 0.06 m to step aside (y-axis). control input 𝑢𝑖 is transformed into foot step 𝑢𝑖𝑥 and 𝑢𝑖𝑦 where 𝑢𝑖𝑥 ≤ 0.08 and 𝑢𝑖𝑦 ≤ 0.06. by using this foot step parameter, the robot’s maximum steps is set to 𝑠𝑗 = 0.08. as a result, robot will move in its maximum velocity if 𝑢𝑖𝑥 > 0.08 or 𝑢𝑖𝑦 > 0.06. d. stability analysis in this subsection, will be carried out analysis of the stability of equation (9). the purpose of this analysis is examining equation (9), to ensure the robot able to avoid obstacles and still returning to its mission toward its desired destination. the analysis was performed using lyapunov stability analysis approach. to understand the analysis, some assumptions and definition are needed. throughout this section, a system of nonlinear differential equations was considered. �̇� = 𝑓(𝑥), 𝑥(𝑡0) = 0 (10) where 𝑥,𝑥0 ∈ ℝ 𝑛 and 𝑓(∙):ℝ𝑛 → ℝ𝑛. 1) definition a) equilibrium point (𝑥∗) : 𝑥∗ is said to be an equilibrium point of equation (10) if 𝑓(𝑥∗) = 0. b) stable equilibrium: the equilibrium point 𝑥∗ = 0 is said to be a stable point of equation (10) if, for all 𝜖 > 0, there exists a 𝛿(𝜖) such that ‖𝑥0‖ < 𝛿(𝜖) ⇒ ‖𝑥(𝑡)‖ < 𝜖,∀𝑡 ≥ 𝑡0 where 𝑥(𝑡) is the solution of equation (10). c) asymptotic stability: the equilibrium point 𝑥∗ = 0 is said to be an asymptotically stable point of (10) if: (a) it is stable; (b) it is attractive, i.e. there exists a 𝛿 such that: ‖𝑥0‖ < 𝛿 ⇒ lim 𝑡→∞ ‖𝑥(𝑡)‖ = 0, where 𝑥(𝑡) is the solution of equation (10). note that (a) above does not necessarily imply (b). d) locally positive definite function: a continuous function 𝑉(𝑥): ℝ𝑛 → ℝ+ is called a locally positive definite function if, for some ℎ > 0 and 𝛼(∙),𝑉(0) = 0 and 𝑉(𝑥) ≥ 𝛼(‖𝑥‖) ∀𝑥:‖𝑥‖ < ℎ where 𝛼(∙): ℝ𝑛 → ℝ+ is continuous, strictly increasing, and 𝛼(0) = 0. 2) assumptions a) the robot’s radii (𝑅𝑟𝑜𝑏𝑜𝑡) is 0.2 m. b) the maximum robot’s walking step (𝑠𝑗 𝑚𝑎𝑥) is 0.08 m. following the works of [4] and [10], analysis is started by noting that: 𝐹𝑖 = 𝐹𝑖 𝑎𝑡𝑡 + 𝐹𝑖 𝑟𝑒𝑝 (11) where 𝐹𝑖 𝑎𝑡𝑡 is the attractive potential function and 𝐹𝑖 𝑟𝑒𝑝 is the repulsive potential function of the i-th robot. intuitively and necessarily, potential functions should have the properties that. { 𝐹𝑖 𝑎𝑡𝑡(0) = 0, ∇𝐹𝑖 𝑎𝑡𝑡(𝑟𝑖 − 𝑟𝑖 𝑑)| (𝑟𝑖−𝑟𝑖 𝑑)=0 = 0, 0 < 𝐹𝑖 𝑎𝑡𝑡(𝑟𝑖 − 𝑟𝑖 𝑑) < ∞,if ‖𝑟𝑖 − 𝑟𝑖 𝑑‖ ≠ 0 is finite, ‖∇𝐹𝑖 𝑎𝑡𝑡(𝑟𝑖 − 𝑟𝑖 𝑑)‖ < +∞ if ‖𝑟𝑖 − 𝑟𝑖 𝑑‖ is finite (12) a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 72 and { 𝐹𝑖 𝑟𝑒𝑝 (𝑟𝑖 − 𝑟𝑜𝑏𝑠) = 0, if(𝑟𝑖 − 𝑟𝑜𝑏𝑠) ∉ 𝑆𝑜𝑏𝑠, 𝐹𝑖 𝑟𝑒𝑝 (𝑟𝑖 − 𝑟𝑜𝑏𝑠) ∈ (0,∞), if (𝑟𝑖 − 𝑟𝑜𝑏𝑠) ∈ 𝑆𝑜𝑏𝑠. (13) it can be defined that: 1. 𝐹𝑖 𝑎𝑡𝑡 > 𝐹𝑖 𝑟𝑒𝑝 , if ‖𝑟𝑖 − 𝑟𝑜𝑏𝑠‖ > 𝑅𝑠𝑎𝑓𝑒, 2. 𝐹𝑖 𝑎𝑡𝑡 < 𝐹𝑖 𝑟𝑒𝑝 , if ‖𝑟𝑖 − 𝑟𝑜𝑏𝑠‖ < 𝑅𝑠𝑎𝑓𝑒, 3. 𝐹𝑖 𝑎𝑡𝑡 = −𝐹𝑖 𝑟𝑒𝑝 , if ‖𝑟𝑖 − 𝑟𝑜𝑏𝑠‖ = 𝑅𝑠𝑎𝑓𝑒 ⟹ equilibrium point (𝑟𝑖 ∗). where 𝑆𝑜𝑏𝑠 is an area around the obstacle, defined as a circle with a radius 𝑅𝑠𝑎𝑓𝑒. this condition is illustrated in figure 7. since this paper focuses on obstacle/collision avoidance, only 𝐹𝑖 𝑟𝑒𝑝 term was considered for analysis. using properties in equation (11) can be rewrote to equation (10) where: 𝑢𝑖 𝑟𝑒𝑝 = 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠)/𝐵 + 𝑤𝑑𝐶𝑑𝑒 0.5√(‖(r𝑖−r𝑗)‖+‖(r𝑖−r𝑗)−𝑠𝑗‖) 2 −𝑠𝑗 2 (14) focused on obstacle/collision avoidance term, define lyapunov-like function candidate for (14) as 𝑉 = 𝑢𝑖 𝑟𝑒𝑝 , where: 𝑉 = 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠) 𝐵 + 𝑤𝑑𝐶𝑑𝑒 0.5√(‖𝑟𝑖𝑗‖+‖𝑟𝑖𝑗−𝑠𝑗‖) 2 −𝑠𝑗 2 (15) assumption iii.1 implies that 𝑟𝑖𝑗 > 2𝑅𝑅𝑜𝑏𝑜𝑡 > 𝑠𝑗. because 𝑤𝑠,𝑤𝑑, 𝐶𝑠, and 𝐶𝑑 are positive scalar, it is obvious that 𝑉 is a positive definite function. to find the derivative function of 𝑉,𝑉 should be seen as 𝑉 = 𝑉𝑎 + 𝑉𝑏where : 𝑉𝑎 = 𝑤𝑠𝐶𝑠𝑒 (𝑟𝑖−𝑟𝑜𝑏𝑠)/𝐵, (16) 𝑉𝑏 = 𝑤𝑑𝐶𝑑𝑒 0.5√(‖(r𝑖−r𝑗)‖+‖(r𝑖−r𝑗)−𝑠𝑗‖) 2 −𝑠𝑗 2 (17) then, by using derivative calculation, the derivative functions of 𝑉𝑎 and 𝑉𝑏 are given by: �̇�𝑎 = − 𝑤𝑠𝐶𝑠 𝐵 𝑒−‖𝑟𝑖−𝑟𝑜𝑏𝑠‖/𝐵 < 0 (18) and �̇�𝑏 = −0.5𝑤𝑑𝐶𝑑𝑒 −0.5√(‖𝑟𝑖𝑗‖+‖r𝑖𝑗−𝑠𝑗‖) 2 −𝑠𝑗 2 ( ‖𝑟𝑖𝑗‖−𝑠𝑗 ‖𝑠𝑗−𝑟𝑖𝑗‖ + 𝑟𝑖𝑗 ‖𝑟𝑖𝑗‖ )(‖𝑠𝑗 − 𝑟𝑖𝑗‖ + ‖𝑟𝑖𝑗‖) < 0 (19) e. system architecture in this subsection, will be described how to implement the new algorithm into a robot. the vs approach needs a special architecture that can perform those three steps. so, the system architecture is built by using three hierarchical layers: a consensus tracking module, a consensus-based formation control module, and the physical robot control module. the elaboration of virtual structure approach into architecture for formation control with obstacle/collision avoidance system is shown in figure 8. figure 7. illustration of obstacle/collision avoidance and formation control figure 8. the elaboration of vs approach into distributed architecture for obstacle/collision avoidance and formation control [3] a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 73 figure 9 shows the robot which was used in the experiment. the robots used for experiment are nao robot from aldebaran robotic, france. iv. result and discussion in this section, some simulation and experiment results of the application of the proposed equation on a group of humanoid robots were presented. as mentioned before, robot’s dynamics is assumed as a single integrator system. for simulation and experiment, 3 robots are placed in the left side of the experiment area and 1 robot on the right. an obstacle also placed randomly in the middle of the area. the group of robots walk to their destination on the right side and the 4th robot walks to left side of the experiment area. a. simulation result simulations were performed on 4 agents, representing 4 robots, using topology in figure 3. the initial position of robot1, robot2, robot3, and robot4 are, respectively, 𝑟𝑅1 = [0.7300,1.1905] , 𝑟𝑅2 = [−0.0081,1.2198] , 𝑟𝑅3 = [−0.0149,0.4276], and 𝑟𝑅4 = [7.1790, 0.4428]; while the obstacle is placed at position 𝑟𝑂𝑏𝑠𝑡 = [2, 0.6]. all these positions are obtained by using vo, which the algorithm is depicted in figure 6. as seen in figure 9, all robots wear a marker on their head. figure 10 shows the simulation result of the proposed algorithm. the result shows that when robot1 met the safety barrier ( 𝑅𝑠𝑎𝑓𝑒 ), it started to avoid the obstacle. during robot1 was avoiding the obstacle (point [a]), robot2, and robot3, also perform an avoidance maneuvers, although there is no obstacle in front of them. this is because the consensus term has worked while the avoidance term has not active yet. this can be seen in the behavior of robot3, as shown in point [b]. at point [c], it is shown that robot2 is following the formation of robot1, but must meet the 𝑅𝑠𝑎𝑓𝑒 of the obstacle. robot2 reacts to turn left, but at point [d] he met with dynamic obstacle (robot4). the reaction of robot3 is keeping its maneuver by continuing to turn left, while robot4 being avoiding static obstacle turn to the right [e]. as result, the two robots constantly avoiding each other, until at some point one of them sense the absence of the obstacle. it’s shown in point [f], where robot4 and robot3 sensed the absence of the obstacle. robot4 was continuing its mission towards point [0, 0.6] and robot3 was returning back to its formation [g]. b. experiment result experiments were performed on 4 nao robot, using topology in figure 3. an asus rt-n10 router, a genius f-120 web camera and a computer were used to perform the experiment. the video of this experiment can be watched on youtube channel [11]. the experiment result is depicted in figure 11 showing that the experiment result also get a similar result to the simulation. figure 9. aldebaran’s nao robots for the experiment figure 10. simulation result figure 11. experiment result a. sadiyoko et al. / j. mechatron. electr. power veh. technol. 06 (2015) 67-74 74 v. conclusion in this research, a new algorithm for obstacle and collision avoidance on a group of humanoid robots inspired by sfm is successfully developed. stability analysis on the new algorithm has proved that algorithm can make a group of humanoid robots avoid obstacle. comparing to our previous results, this algorithm has a smoother avoidance maneuver and faster to return to its formation. it also found in this study that the ca part on the algorithm is succeeded to maintain the position of the robot back to its formation. in the case of robot is trapped in a crowded situation (singularity condition), robot will still trying to look a new position, until it find a condition that allow him to move forward. acknowledgement the authors would like to thank to advanced robotic laboratory at school of electronic engineering and informatics, institut teknologi bandung for providing all robots and facilities for the research. references [1] weidlich, w. "sociodynamics – a systematic approach to mathematical modelling in the social sciences," an interdisciplinary journal on nonlinear phenomena in complex systems, vol. 5, no. 4, 2002, pp. 479-487. [2] d. helbing and p. molnár. "social force model for pedestrian dynamics," physical review e, vol 51, may, 1995, pp. 4282– 4286. [3] a. sadiyoko et al., “consensus algorithm for obstacle avoidance and formation control,” proceedings of 10 th asian control conference, 2015. [4] cao et al., “an overview of recent progress in the study of distributed multi-agent coordination,” ieee trans. on industrial informatics, vol. 9, no. 1, 2013, pp. 427438. [5] moussaïd et al., “how simple rules determine pedestrian behavior and crowd disasters,” proceedings of the national academy science of the usa, vol. 108, no. 17, 2011, pp. 6884-6888. [6] m. casini et al., “a lego mindstorms multi-robot setup in the automatic control telelab,” proc. of the 18 th world congress of the international federation of automatic control (ifac2011), 2011, pp. 9812-9817. [7] m. ho et al., “collision free cooperative navigation of multiple wheeled robots in unknown cluttered environments,” robot. auton. syst., vol. 60, no. 10, october 2012, pp. 1253-1266. [8] d. panagou et al., “multi-objective control for multi-agent systems using lyapunovlike barrier functions,” proceedings of the 52 nd annual conference on decision and control (cdc), 2013, pp. 1478-1483. [9] z. chao et al., “collision-free uav formation flight control based on nonlinear mpc,” proceedings of the ieee international conference on electronics, communication & control, 2011, pp. 19511956. [10] j. chunyu et al., “a new reactive targettracking control with obstacle avoidance in a dynamic environment,” proceedings of the 2009 american control conference, 2009, pp. 3872-3877. [11] a. sadiyoko, “nao: robots formation control, obstacle & collision avoidance,” https://youtu.be/2793rwcamgm, 2015. mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.50-59 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. afr and fuel cut-off modeling of lpg-fueled engine based on engine, transmission, and brake system using fuzzy logic controller (flc) muji setiyo*, suroto munahar department of automotive engineering, universitas muhammadiyah magelang jl. bambang sugeng km.05 mertoyudan magelang 56172 indonesia received 17 april 2017; received in revised form 2 june 2017; accepted 13 june 2017 published online 31 july 2017 abstract during deceleration, continuous fuel flows into the engine not only causing over fuel consumption but also increasing exhausts emissions. therefore, this paper presents a simulation of afr and fuel cut-off modeling in the lpg-fueled vehicle using fuzzy logic controller (flc). the third generation of lpg kits (liquid phase injection, lpi) was chosen due to its technological equivalency to efi gasoline engine and promising to be developed. given that the fuel system control is complex and non-linear, flc has been selected because of simple, easy to understand, and tolerant to improper data. simulation results show that the afr and fuel cut-off controller able to maintenance afr at the stoichiometric range during normal operation and able to cut the fuel flow at deceleration time for saving fuel and reducing emissions. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: lpg-fueled engine; deceleration; flc; afr; fuel cut-off i. introduction over the last decade, declining air quality, especially in urban areas has become a serious concern since it has direct impacts on human health. the transportation sector becomes a major contributor to increased air pollutant, emissions, and global greenhouse gas [1]. now, most countries have implemented a policy of fuel economy standards for vehicles as an effective way to reduce oil consumption, carbon emissions, and air pollution. the internal combustion engine technology is also evolving in that direction [2, 3, 4, 5]. the use of lpg as an alternative fuel is also a trend in some countries as a medium-term solution, which until 2016, reportedly there are over 26 million lpg vehicles in use around the world and over 74,000 refueling sites [6]. therefore, this paper presents a simulation of afr controller and fuel cut-off during deceleration in the lpg-fueled engine as an effort to reduce fuel consumption and emissions. currently, the effort to reduce exhaust emissions from the automotive sector to improve urban air quality and public health is stronger than ever before [1, 2]. in the urban areas, particulate matter (pm) of the internal combustion engine has also become a concern [3, 4, 5]. especially in the spark ignition (si) engine, reducing fuel consumption and co2 are also a concern in the present. in the last decades, the alternative automotive propulsion technologies such as fuel cells vehicles and electric vehicles have been commercialized as the green vehicles. however, fuel cell and electric vehicles will be facing the limited of mileage and high total cost of ownership [7]. developing of bio-fuel as the alternative fuel will also be constrained by the availability of land for production [8, 9]. as a result, lpg will be a choice for at least two decades in the future as long as the price competes with gasoline [8]. on the other hand, fuel consumption and exhaust emissions from motor vehicles will be regulated more strictly [10]. combustion with a lean mixture that is controlled by engine management systems (ems) becomes the trend development of today's lpg engine [11]. in indonesia, the implementation of low-emissions vehicles has become a government program through * corresponding author. tel: +62 823 3062 3257 e-mail address: setiyo.muji@ummgl.ac.id https://dx.doi.org/10.14203/j.mev.2017.v8.50-59 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.50-59 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.50-59&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:setiyo.muji@ummgl.ac.id m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 51 low-cost green car and low carbon emission program [12]. initially, the air to fuel ratio (afr) entering the lpg engine was regulated only by converter and mixer or simple electronic control [13]. the stoichiometric mixture is obtained only at partial conditions. now, the liquid phase injection (lpi) of lpg-fueled engines has been supported by mechatronic systems with sensors, actuators, and control system (figure 1). several treatments have also been made to improve performance, fuel economy, and emissions [14, 15]. afr settings were intended to produce complete combustion throughout the engine load [16, 17]. in fact, the need for engine power is more than the fulfillment of low emissions. for example, tests performed by massi and gobbato, fiat 838 a-1.000 engine describe the actual afr is lower than stoichiometric afr (15.7) for the most of the engine load, from 1000 rpm to 7000 rpm [18]. in the other case, there is significant variation in vehicle emissions during acceleration, deceleration, and cruising [19, 20]. the principle of lpi is the same as the gasoline efi engine. liquid lpg is supplied from the tank to the fuel rail and then injected into the intake manifold. lpg evaporation occurs entirely in the intake manifold [6]. the lpi system has the potential to achieve fuel savings, produce better power, and lower emissions than the vpi system. subsequently, the main problem of afr control is to solve the nonlinear problem [22]. nowadays, the look-up tables combining with the proportional and integral feedback controller is widely used for afr control method because of its simple structure and robustness. however, this method is inefficient due to many engine variants and components [23]. the development of control technology also shows significant progress. nonlinear model predictive control (nmpc) has been attempted for si engines to obtain the desired afr in si engine [24, 25, 26]. studies conducted by wang shows that the good control performance was obtained by adaptive radial basis function (rbf) model based nmpc method for afr control [27]. generally, afr is controlled largely only by engine sensors. meanwhile, the need for proper fuel in vehicles is not only influenced by the engine behavior but also influenced by the behavior of vehicles, such as braking condition and gear position. it is known that a car consists of a complex system with power flow as shown in figure 2. during acceleration, the engine drives the wheels so that the engine speed and vehicle speed are increased in accordance with the throttle valve opening. conversely, the vehicle inertia makes the engine speed higher than the proportion of throttle valve opening during deceleration. therefore, a possible method for controlling afr is by using fuzzy logic control (flc) [22]. flc was chosen by many researchers because it has relatively good system stability, able to resolve the black box problem, and can be applied on a multi input multi output (mimo) [28, 29]. flc has been widely applied to car engine control as afr control, emissions, and torque [31, 32, 33]. however, the application for afr control is the most popular researched. most of the flc applications on si engines are to limit afr in narrow bands around stoichiometric values to meet the limits imposed on automotive emissions with constraints from engine systems only. it consists of three sub-models that describe the dynamics of the intake manifold (including airflow, pressure, and air temperature), crankshaft speed, and fuel injection [33, 34]. afr control based on the braking system was conducted by triwiyatno et al. [35] that is quite promising to reduce fuel consumption. afr control with additional external control of the engine is very likely to be developed. in addition to the brake system, another system that may be involved is the transmission system. in fact, wasted fuel is influenced by faulty transmission gear position. the combination of the engine, brake, and transmission systems as a controlling factor of afr are particularly important, considering the vehicle often operates in downhill roads, highways, urban cycle, or in congestion [36, 37, 38]. in the previous study [39], afr modeling on efi engines based on engine dynamics, transmission, and vehicle dynamics also has been done without considering the dynamics of braking. as a result, the controller is unable to perform a fuel cut-off during vehicle deceleration below 80 mph. figure 1. liquid phase injection of lpg fuel systems [21] figure 2. lpg-fueled vehicle propulsion and power train systems [30] m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 52 therefore, this paper presents the afr modeling of lpi engine based on engine, brake, and transmission system using flc to improve fuel efficiency. more specifically, in addition to controlling afr, this study proposes a fuel cut-off method during the vehicle deceleration. by keeping the afr in the stoichiometric range and making the fuel cut-off during deceleration that able to reduce emissions. the vehicle used in this study is toyota 5a-fe which has been modified to lpg fuel systems. ii. modelling in this study, the throttle valve serves as the primary input to control engine speed. subsequently, the engine rotation is distributed to the wheels of the vehicle through the gear box (transmission). the opening of the throttle valve increases engine speed which indicates vehicle acceleration. the vehicle deceleration occurs because of two conditions, braking or throttles valve closure without braking. the brake system not only serves to slow down the vehicle but also to control the fuel. so that the fuel control system has several inputs including vehicle speed, engine speed, throttle valve position and brake systems. meanwhile, gear box provides the transmission ratio to change the vehicle speed. the block diagram of vehicle modeling is presented in figure 3. a. model of engine dynamics based on figure 3, the opening of the throttle valve causes air to enter the intake chamber and then the engine cylinder through the engine valves. in this case, the mass of air entering the intake manifold is affected by pressure and temperature. without involving the egr, formulation for intake pressure, intake temperature, and air mass that goes into the engine is presented in equation (1), (2), (3), and (4), respectively. ṗi = kr vi (−ṁap + ṁatta) (1) ṫi = rti pivi [−ṁap(k − 1)ti + ṁat(kta − ti)] (2) ṁap (u, ṗi) = ṁat1 pa √ta β1(u)β2(pr) + ṁat0 (3) ṁat(u, ṗi) = vd 120rti (ηi. pi)n (4) where �̇�𝑖 is the intake manifold pressure (bar). k is ratio of the specific heats (1.4 for air) and r is the constant of ideal gas (287 x 10-5). 𝑉𝑖 is the intake manifold volume in (m3). �̇�𝑎𝑝 and �̇�𝑎𝑡 are the air mass flow into intake port and air mass flow pass throttle plate (kg/s). 𝑇𝑎 and 𝑇𝑖 are the ambient temperature and intake air temperature (k). 𝛽1(𝑈) is the throttle valve position and 𝛽1(𝑃𝑟 ) is intake manifold pressure ratio [27]. 𝑉𝑑 is engine displacement (m3) and 𝜂𝑖 is volumetric efficiency. finally, n is the engine speed (rpm) and 120 is correction factor for four stroke si engine. the dynamics of the fuel injection also has been observed by hendricks et al. [40] and wang et al. [27]. the formulation of fuel dynamics is presented in equation (5), (6), (7) and (8) as follows. m̈ff = 1 τf (−ṁff + xfṁfi) (5) ṁfv = (1-xf)ṁfi (6) ṁf = ṁfv+ṁff (7) xf(pi, n) = −0.27pi − 0.055n + 0.68 (8) where, �̇�𝑓𝑓 , �̇�𝑓𝑖 , �̇�𝑓𝑣 , and �̇�𝑓 are the fuel film mass flow, injected fuel mass flow, fuel vapor mass flow, and engine port fuel mass flow (g/s), respectively. 𝜏𝑓 is the constant time of fuel evaporation and 𝑋𝑓 is proportion of fuel. meanwhile, 𝜏𝑓 is a function of the engine speed (n) and intake manifold pressure (𝑃𝑖 ) with a formulation as in equation (9). then, afr calculation is obtained from air mass flow into intake port (�̇�𝑎𝑝) compared with the engine port fuel mass flow (�̇�𝑓 ) (equation 10). 𝜏𝑓 (𝑃𝑖 , 𝑛) = 1.35(−0.672𝑛 + 1.68)(𝑃𝑖 − 0.825) 2 + (0.06𝑛 + 0.15) + 0.56 (9) afr = ṁap ṁf (10) the crankshaft speed dynamics(�̇�) is presented in equation (11). intake manifold pressure (𝑃𝑖), pumping power(𝑃𝑝 ) and crankshaft speed have a relation to the friction power (𝑃𝑓 ) and load power (𝑃𝑏 ) . thus, stoichiometric afr (λ = 1) , crankshaft speed (𝑛) , and the intake manifold pressure to be a factor of figure 3. block diagram of vehicle modeling for afr controlling m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 53 indicated efficiency(𝜂𝑖 ). 𝐻𝑢is fuel lower heating value (kj/kg). �̇� = 1 𝑙𝑛 (𝑃𝑓 (𝑃𝑖 , 𝑛) + 𝑃𝑝(𝑃𝑖 , 𝑛) + 𝑃𝑏 (𝑛) + 1 𝑙𝑛 𝐻𝑢 𝜂𝑖(𝑃𝑖 , 𝑛, 𝜆)�̇�𝑓 (𝑡 − ∆𝜏𝑑 ) (11) the delay in the fuel injection system has been observed by manzie et al. [41], which include injection systems, engine cycle, and exhaust valve expulsion. injection delay model is presented in equation (12) as follow. 𝜏𝑑 = 0.045 + 10𝜋 𝑛 (12) where, 𝜏𝑑 time delay of fuel injection system and 0.045 is propagation delay [17]. b. model of drive train dynamics in this study, the drive train is divided into two sub-systems (i.e. clutch and transmission). clutch presented the mechanisms for connecting and disconnecting the engine speed to the transmission. the clutch system is presented in equation (13). k is the capacity factor, 𝑁𝑖𝑛 and 𝑁𝑒 is the input transmission speed and engine speed in rpm, respectively. f2/f3 is transmission ratio (gear). the torque ratio (rtq) is formulated in equation (14). k = f2 nin ne (13) rtq = f3 nin ne (14) transmission ratio (𝑅𝑇𝑅 ) is obtained from the transmission gear ratio. 𝑇𝑖𝑛 and 𝑇𝑜𝑢𝑡 are the input and output torque of transmissin, respectively. 𝑁𝑖𝑛 and 𝑁𝑜𝑢𝑡 as the input and output speed of transmission shaft. 𝑅𝑇𝑅 = 𝑁𝑖𝑛 𝑁𝑜𝑢𝑡 (15) furthermore, the transmission ratio(𝑅𝑇𝑅 )of the vehicle used in this study is presented in table 1 as follows. c. vehicle dynamics the vehicle’s movement is not only influenced by the engine speed but also by the vehicle inertia (𝐼𝑣 ) and vehicle load variations [42]. vehicle inertia is also affected by wheel speed (𝑁𝑤 ) in rpm, final drive ratio (𝑅𝑓𝑑 ) , load torque (𝑇𝑙𝑜𝑎𝑑 ) , and output transmission torque (𝑇𝑜𝑢𝑡 ) as shown in equation (16). 𝐼𝑣 . 𝑁𝑤 = 𝑅𝑓𝑑 . (𝑇𝑜𝑢𝑡 − 𝑇𝑙𝑜𝑎𝑑 ) (16) a form of the vehicle body affects the speed of vehicles because of barriers surrounding air. finally, road conditions also resulted in the brake operation. 𝑇𝑙𝑜𝑎𝑑 = 𝑠𝑔𝑛(𝑚𝑝ℎ)(𝑅𝑙𝑜𝑎𝑑0 + 𝑅𝑙𝑜𝑎𝑑2𝑚𝑝ℎ 2 + 𝑇𝑏𝑟𝑎𝑘𝑒 ) (17) where, 𝑅𝑙𝑜𝑎𝑑0𝑅𝑙𝑜𝑎𝑑2as the friction and coefficient drag, 𝑇𝑏𝑟𝑎𝑘𝑒 is the brake torque, and mph is the linier vehicle velocity. d. membership function fuzzy logic controller (flc) requires the value of membership function (mf) as an input. mf is a curve that shows the points mapping of input data into membership values (degree of membership) which have the interval between 0 and 1. the mf curve is presented in figure 4. then, the fuzzy set decision is presented in table 2 and table 3. fuel controller system approach is pid and fuzzy. compensator formula controlled of pid is 𝑃 + 𝐼 1 2 + 𝐷 𝑁 1+𝑁 1 𝑠 . the value proportional is 0.000003, integral is 0.0027, and derivative is 0.000005. iii. result and discussion a. input condition in this study, driving dynamic as driver behavior is presented in several sections. throttle angle represents the throttle valve position in degree. brake position represents the driver behavior when performing of vehicle deceleration. braking signal generates by the hydraulic pressure sensor between 0 to 5 kg/cm². hydraulic pressure above of 3 kg/cm² is considered as a braking condition to stop the vehicle and hydraulic pressure below of 3 kg/cm² is considered as the deceleration of the vehicle. gear position represents the position of the transmission gear, from 1 to 4. the driving dynamic is divided into two modes. braking mode as the driver presses the brake pedal and unbraking mode as the driver does not press the brake pedal. the relation between the driver behavior, controller, and vehicle dynamic is presented in figure 5. b. deceleration at low speed at the low speed, the engine is simulated for 10 seconds which represents an acceleration and deceleration. referring to figure 3 and figure 5, the main input of the engine is a throttle valve position (0% means fully closed valve and 100% means fully opened valve). the first period (0 seconds), the throttle valve is opened about 22%. the second period (from 0 to 10 second), the throttle valve is linear opened from 22% to 25%. the third period (exactly at 10 seconds), the throttle valve is closed from 25% to 19%. the third period is kept up to 30 seconds. dynamics of throttle valve position and brake signal are presented in figure 6. it is known that when the throttle valve is opened, the air and fuel are sucked into the cylinder, and then combustion pressure will generate an engine speed. table 1. transmission ratio (rtr) gear position transmission ratio (𝑹𝑻𝑹) 1 3.55 2 1.91 3 1.31 4 0.97 5 0.82 m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 54 the throttle valve is opened from 22% to 30% increasing the engine speed from 1000 rpm to 3200 rpm and increasing the vehicle speed from 0 mph to 82 mph. in the time the throttle is closed abruptly (10 seconds), engine speed decreases to 2000 rpm (figure 7a). however, the vehicle still cruised at high speed. the decrease in vehicle speed is not the same as a decrease in engine speed. noting the equation (1) to (12) was processed by flc, the results of engine speed and vehicle speed (with throttle valve position according to figure 6) are presented in figure 7. without afr controller, the fuel flowing into the cylinder is not required. therefore, the effect of the controller to afr is presented in figure 8. in figure 8a, there is an area where afr is not detected. this figure 4. membership function of (a) engine speed; (b) throttle angle; (c) vehicle speed; and (d) brake sensor figure 5. vehicle modeling with transmission dan brake control system m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 55 indicates that no fuel is injected into the engine, where the exhaust gas emissions are only air without combustion products. in figure 8b, there is a fuel saving area, where this area is a fuel cut-off by the controller, i.e. no fuel flows to the engine. c. deceleration at high speed as well as at low speeds, at high speed, the engine is simulated for 10 seconds which represents an acceleration and deceleration. referring to figure 3 and figure 5, the main input of the engine is a throttle valve position. the first period (0 seconds), the throttle valve is opened 22%. table 2. fuzzy set decision based on brake position “none” and "soft no engine speed brake position vehicle speed throttle angle decision 1 low (0 to 1400 rpm) none slow ( 0 to 25 mph) small ( 0 to 25 %) off 2 medium (1200 to 3200 rpm) none slow ( 0 to 25 mph) small ( 0 to 25 %) off 3 high (2800 to 7000 rpm) none slow ( 0 to 25 mph) small ( 0 to 25 %) off 4 low (0 to 1400 rpm) none medium ( 18 to 83 mph) small ( 0 to 25 %) off 5 medium (1200 to 3200 rpm) none medium (18 to 83 mph) small ( 0 to 25 %) off 6 high (2800 to 7000 rpm) none medium ( 18 to 83 mph) small ( 0 to 25 %) off 7 low (0 to 1400 rpm) none fast ( 80 to 120 mph) small ( 0 to 25 %) off 8 medium (1200 to 3200 rpm) none fast ( 80 to 120 mph) small ( 0 to 25 %) on 9 high (2800 to 7000 rpm) none fast ( 80 to 120 mph) small ( 0 to 25 %) on 10 low (0 to 1400 rpm) none slow ( 0 to 25 mph) medium (18 to 55 %) off 11 medium (1200 to 3200 rpm) none slow ( 0 to 25 mph) medium (18 to 55 %) off 12 high (2800 to 7000 rpm) none slow ( 0 to 25 mph) medium (18 to 55 %) off 13 low (0 to 1400 rpm) none medium ( 18 to 83 mph) medium (18 to 55 %) off 14 medium (1200 to 3200 rpm) none medium ( 18 to 83 mph) medium (18 to 55 %) off 15 high (2800 to 7000 rpm) none medium ( 18 to 83 mph) medium (18 to 55 %) off 16 low (0 to 1400 rpm) none fast ( 80 to 120 mph) medium (18 to 55 %) off 17 medium (1200 to 3200 rpm) none fast ( 80 to 120 mph) medium (18 to 55 %) off 18 high (2800 to 7000 rpm) none fast ( 80 to 120 mph) medium (18 to 55 %) off 19 low (0 to 1400 rpm) none slow ( 0 to 25 mph) high (50 to 100 %) off 20 medium (1200 to 3200 rpm) none slow ( 0 to 25 mph) high (50 to 100 %) off 21 high (2800 to 7000 rpm) none slow ( 0 to 25 mph) high (50 to 100 %) off 22 low (0 to 1400 rpm) none medium ( 18 to 83 mph) high (50 to 100 %) off 23 medium (1200 to 3200 rpm) none medium ( 18 to 83 mph) high (50 to 100 %) off 24 high (2800 to 7000 rpm) none medium ( 18 to 83 mph) high (50 to 100 %) off 25 low (0 to 1400 rpm) none fast ( 80 to 120 mph) high (50 to 100 %) off 26 medium (1200 to 3200 rpm) none fast ( 80 to 120 mph) high (50 to 100 %) off 27 high (2800 to 7000 rpm) none fast ( 80 to 120 mph) high (50 to 100 %) off 28 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 29 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 30 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 31 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 32 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 33 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 34 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 35 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) on 36 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) on 37 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 38 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 39 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 40 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 41 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 42 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 43 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 44 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 45 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 46 high (2800 to 7000 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 47 low (0 to 1400 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 48 medium (1200 to 3200 rpm) soft ( 0 to 2 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 56 table 3. fuzzy set decision based on brake position “half” and “hard” no engine speed brake position vehicle speed throttle angle decision 49 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 50 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 51 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 52 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 53 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 54 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 55 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 56 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) on 57 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) on 58 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 59 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 60 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 61 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 62 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 63 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 64 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 65 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 66 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 67 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 68 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 69 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 70 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 71 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 72 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 73 medium (1200 to 3200 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 74 high (2800 to 7000 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 75 low (0 to 1400 rpm) half ( 0.7 to 3 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 76 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 77 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 78 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) high (50 to 100 %) off 79 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 80 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 81 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) high (50 to 100 %) off 82 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 83 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) off 84 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) small ( 0 to 25 %) on 85 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) on 86 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 87 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) small ( 0 to 25 %) off 88 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 89 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 90 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) small ( 0 to 25 %) off 91 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 92 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 93 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) medium (18 to 55 %) off 94 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 95 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 96 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) medium ( 18 to 83 mph) medium (18 to 55 %) off 97 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 98 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 99 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) fast ( 80 to 120 mph) medium (18 to 55 %) off 100 low (0 to 1400 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 101 medium (1200 to 3200 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off 102 high (2800 to 7000 rpm) hard ( 2.3 to 5 kg/cm² ) slow ( 0 to 25 mph) high (50 to 100 %) off m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 57 the second period (from 0 to 10 second), the throttle valve is linear opened from 22% to 38%. the third period (exactly at 10 seconds), the throttle valve is closed from 30% to 19% respectively. the third period is kept up to 30 seconds. dynamics of throttle valve angle is presented in figure 9. when the throttle valve is opened from 22 % to 38 %, the engine capable of operating up to 4200 rpm and vehicle speed reaches 110 mph. at the time of the gas pedal is released suddenly (10 seconds), the engine fell into 2000 rpm. however, this condition is not followed by a decrease in vehicle speed. the dynamics of the engine and vehicle speed are presented in figure 10 and figure 11, respectively. figure 6. simulation of (a) throttle valve position; and (b) brake signal from 0 to 30 seconds figure 7. engine speed (a) and vehicle speed (b) from 0 to 30 seconds based on throttle position and brake signal from figure 5 figure 8. afr (a) and fuel consumption (b) from 0 to 30 seconds based on throttle position and brake signal from figure 6 figure 9. simulation of throttle valve dynamics at high engine speed m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 58 afr dynamics generated during deceleration time is presented in figure 12(a). initially, afr value shows at 15.6. at the time of throttle valve closed, afr is illegible. this means the economizer works and no fuel injected into the engine. as a result, there is a fuel-cutting area for 13 seconds, showed in figure 12(b). this shows significant fuel savings during vehicle deceleration, without interfere the vehicle performance during acceleration and cruising. iv. conclusion a series of simulation results indicates that modeling flc to afr controlling cut-off fuel during deceleration on lpi-lpg fueled engine which is a non-linear condition can be applied at low speed and high speed condition. the throttle valve position, engine speed, transmission system, and brake operation were able to control the afr and fuel flow into the engine in the desired condition. at the time of deceleration, afr is not detected for several times, which means there is no fuel flow from fuel line into the engine. in conclusion, flc is a promising to be applied on lpi-lpg fueled engine for fuel saving. acknowledgement this research is fully supported by automotive laboratory and research division of universitas muhammadiyah magelang. the researchers are grateful to both institutions. references [1] gfei, “improving vehicle fuel economy in the asean region,” london, 2010. [2] s. karagiorgis et al., “control challenges in automotive engine management,” european journal of control, vol. 13, no. 2–3, pp. 92–104, jan. 2007. [3] s. t. anderson et al., “automobile fuel economy standards: impacts, efficiency, and alternatives,” review of environmental economics and policy, vol. 5, no. 1, pp. 89– 108, 2011. [4] k. ravi and e. porpatham, “effect of piston geometry on performance and emission characteristics of an lpg fuelled lean burn si engine at full throttle condition,” applied thermal engineering, vol. 110, pp. 1051–1060, 2017. [5] m. el-faroug et al., “spark ignition engine combustion, performance and emission products from hydrous ethanol and its blends with gasoline,” energies, vol. 9, no. 12, p. 984, 2016. [6] world lpg association, “autogas incentive policies, 2015 update,” neuilly-sur-seine, 2015. [7] m. messagie et al., “environmental and financial evaluation of passenger vehicle technologies in belgium,” sustainability (switzerland), vol. 5, no. 12, pp. 5020–5033, 2013. [8] m. setiyo et al., “techno-economic analysis of liquid petroleum gas fueled vehicles as public transportation in indonesia,” international journal of energy economics and policy, vol. 6, no. 3, pp. 495–500, 2016. [9] iea, “biofuels for transport in 2050,” paris, 2011. [10] f. an et al., “global overview on fuel efficiency and motor vehicle emission standards: policy options and perspectives for international cooperation,” new york, 2011. [11] world lpg association, “autogas incentive policies,” neuilly-sur-seine, 2016. [12] gaikindo, “indonesia automotive industry report on 2013 auto market,” in the 20th apec automotive dialogue, 2014, no. april. figure 12. (a) afr; and (b) fuel consumption from 0 to 30 seconds based at the time of deceleration from high speed figure 10. engine speed based on throttle dynamics from figure 9 figure 11.vehicle speed based on throttle dynamics from figure 8 m. setiyo and s. munahar / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 50–59 59 [13] m. setiyo et al., “characteristics of 1500 cc lpg fueled engine at various of mixer venturi area applied on tesla a-100 lpg vaporizer,” jurnal teknologi, vol. 78, no. 10, pp. 43–49, 2016. [14] f. hofmann, converting vehicles to propane autogas part 4: troubleshooting four current autogas fuel systems. washington, d.c, usa: propane education & research council, 2012. [15] a. kaleli et al., “controlling spark timing for consecutive cycles to reduce the cyclic variations of si engines,” applied thermal engineering, vol. 87, pp. 624–632, 2015. [16] c. park et al., “combustion and emission characteristics according to the fuel injection ratio of an ultra-lean lpg direct injection engine,” energies, vol. 9, no. 11, p. 920, 2016. [17] c. manzie et al., “air fuel ratio control in liquefied petroleum gas injected si engines,” in triennial world congress, 2002. [18] m. masi and p. gobbato, “measure of the volumetric efficiency and evaporator device performance for a liquefied petroleum gas spark ignition engine,” energy conversion and management, vol. 60, pp. 18–27, 2012. [19] j. gallus et al., “impact of driving style and road grade on gaseous exhaust emissions of passenger vehicles measured by a portable emission measurement system (pems),” transportation research part d: transport and environment, vol. 52, no. 2, pp. 215–226, 2017. [20] y. zhang et.al, “evaluation of vehicle acceleration models for emission estimation at an intersection,” transportation research part d: transport and environment, vol. 18, no. 1, pp. 46–50, 2013. [21] gazeo, “autogas system generations,” global lpg & cng portal, 2012. [online]. available: http://gazeo.com/automotive/technology/autogas-systemgenerations,article,6486.html. [accessed: 23-may-2017]. [22] b. a. al-himyari et al., “review of air-fuel ratio prediction and control methods,” asian journal of applied sciences, vol. 2, no. 4, pp. 471–478, 2014. [23] y. shi et al., “air-fuel ratio prediction and nmpc for si engines with modified volterra model and rbf network,” engineering applications of artificial intelligence, vol. 45, pp. 313–324, 2015. [24] y.-j. zhai and d.-l. yu, “neural network model-based automotive engine air/fuel ratio control and robustness evaluation,” engineering applications of artificial intelligence, vol. 22, no. 2, pp. 171–180, 2009. [25] s. wang and d. l. yu, “adaptive rbf network for parameter estimation and stable air–fuel ratio control,” neural networks, vol. 21, no. 1, pp. 102–112, 2008. [26] i. arsie et al., “a procedure to enhance identification of recurrent neural networks for simulating air–fuel ratio dynamics in si engines,” engineering applications of artificial intelligence, vol. 19, no. 1, pp. 65–77, 2006. [27] s. w. wang et al., “adaptive neural network model based predictive control for air-fuel ratio of si engines,” engineering applications of artificial intelligence, vol. 19, no. 2, pp. 189– 200, 2006. [28] t. m. guerra et al., “conditions of output stabilization for nonlinear models in the takagi-sugeno’s form,” fuzzy sets and systems, vol. 157, no. 9, pp. 1248–1259, 2006. [29] m. zhou et al., “a review of vehicle fuel consumption models to evaluate eco-driving and eco-routing,” transportation research part d: transport and environment, vol. 49, pp. 203–218, 2016. [30] c. g. foster et al., “automobile,” encyclopædia britannica. [online]. available: https://www.britannica.com/technology/automobile. [accessed: 11-dec-2016]. [31] mohammad al zubi and ayman m. mansour, “detection of automotive emissions status using fuzzy inference system \n,” iosr journal of mechanical and civil engineering (iosr-jmce), vol. 10, no. 4, pp. 17–23, 2013. [32] a. triwiyatno et al., “engine torque control of spark ignition engine using robust fuzzy logic control,” iacsit international journal of engineering and technology, vol. 3, no. 4, pp. 352–358, 2011. [33] m. j. nekooei and j. koto, “hybrid fuzzy logic controller in matlab / simulink for controlling afr of si engine,” international journal of environmental research & clean energy, vol. 5, no. 1, pp. 11–20, 2017. [34] a. ghaffari et al., “adaptive fuzzy control for air-fuel ratio of automobile spark ignition engine,” engineering and technology, pp. 284–292, 2008. [35] a. triwiyatno et al., “smart controller design of air to fuel ratio (afr) and brake control system on gasoline engine,” in icitacee 2015 2nd international conference on information technology, computer, and electrical engineering, 2016, pp. 233–238. [36] k. zhang et al., “vehicle emissions in congestion: comparison of work zone, rush hour and free-flow conditions,” atmospheric environment, vol. 45, no. 11, pp. 1929–1939, 2011. [37] j. edquist et al., road design factors and their interactions with speed and speed limits report 298. 2009. [38] j. d. clapp et al., “the driving behavior survey: scale construction and validation,” journal of anxiety disorders, vol. 25, no. 1, pp. 96–105, 2011. [39] s. munahar and m. setiyo, “afr modeling of efi engine based on engine dynamics, vehicle dynamics, and transmission system,” jurnal teknik mesin, vol. 7, no. 1, pp. 21–29, 2017. [40] e. hendricks et al., “a generic mean value engine model for spark ignition engines,” in proceedings of the 41st simulation conference sims, 2000. [41] c. manzie et al., “model predictive control of a fuel injection system with a radial basis function network observer,” journal of dynamic systems, measurement and control, transactions of the asme, vol. 124, no. 4, pp. 648–658, 2002. [42] mathworks, “modeling an automatic transmission controller,” mathworks documentation. 2016. j. mechatron. electr. power veh. technol. 06 (2015) 83-88 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2015 rcepm lipi all rights reserved. open access under cc by-nc-sa license. accreditation number: 633/au/p2mi-lipi/03/2015. doi: 10.14203/j.mev.2015.v6.83-88 development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping gesang nugroho a, *, zahari taha b, tedy setya nugraha a, hatyo hadsanggeni a adepartment of mechanical and industrial engineering, faculty of engineering, universitas gadjah mada yogyakarta 55281, indonesia binnovative manufacturing, machatronics and spots lab (imams), universiti malaysia pahang pahang, malaysia received 29 october 2015; received in revised form 03 december 2015; accepted 03 december 2015 published online 30 december 2015 abstract the development of remote sensing technology offers the ability to perform real-time delivery of aerial video and images. a precise disaster map allows a disaster management to be done quickly and accurately. this paper discusses how a fixed wing uav can perform aerial monitoring and mapping of disaster area to produce a disaster map. this research was conducted using a flying wing, autopilot, digital camera, and data processing software. the research starts with determining the airframe and the avionic system then determine waypoints. the uav flies according to the given waypoints while taking video and photo. the video is transmitted to the ground control station (gcs) so that an operator in the ground can monitor the area condition in real time. after obtaining data, then it is processed to obtain a disaster map. the results of this research are: a fixed wing uav that can monitor disaster area and send real-time video and photos, a gcs equipped with image processing software, and a mosaic map. this uav used a flying wing that has 3 kg empty weight, 2.2 m wingspan, and can fly for 12-15 minutes. this uav was also used for a mission at parangtritis coast in the southern part of yogyakarta with flight altitude of 150 m, average speed of 15 m/s, and length of way point of around 5 km in around 6 minutes. a mosaic map with area of around 300 m x 1500 m was also obtained. interpretation of the mosaic led to some conclusions including: lack of evacuation routes, residential area which faces high risk of tsunami, and lack of green zone around the shore line. keywords: uav; remote sensing; disaster monitoring; disaster area mapping; photo mosaic. i. introduction the development of aircraft began when joseph-michel montgolfier and jacques-étienne montgolfier invented montgolfière-style hot balloon air. a few decades later, wright brothers inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight. in this decade, the development of the aircraft not only focused on manned vehicle but also unmanned vehicle. recently, the applications of unmanned aerial vehicles have been more popular in the military field. even so, actually unmanned aerial vehicle can be applied for nonmilitary mission. the most popular application is the use of unmanned aerial vehicles for the surveillance mission. unmanned aerial vehicles (uavs) have several characteristics that make them potentially attractive for cooperative monitoring applications. these characteristics include no danger to human pilots, long endurance, potential for real-time data dissemination, shared control among several parties to an agreement, potential to tailor uavs to a particular mission, and low cost [1]. in fact, there are several applications of unmanned aerial vehicles for surveillance mission, the most popular example is the observation of volcano’s activities. unmanned aerial vehicle for observation volcano has the purpose to get photos and videos of volcanoes from cruising altitude that can be reach by this aircraft. with photos and video that have been obtained and then interpreted by volcanic experts, the status can be determined so that the government may soon be able to perform a * corresponding author.phone: +6281392690990 e-mail: gesangnugroho@ugm.ac.id http://dx.doi.org/10.14203/j.mev.2015.v6.83-88 g. nugroho et al. /j. mechatron. electr. power veh. technol. 06 (2015) 83-88 84 variety of anticipation for the safety of the surrounding community. the uavs some times known as drones, offer aviable alternative to conventional platforms for acquiring highresolution for coastal and environmental remotesensing data at lower cost, increase operational flexibility and greater versatility [2]. rapid growth in the application of uav for generating hight-resolution toporaphic data due to development of low-cost, rapid deployment uav platforms and sfm algorithms. some of the considerations and regulations which must be adhered to when operating uavs in many situations for aerial survey of pro-glacial push moraines in iceland was reported [3]. unmanned aerial vehicles (uavs) equipped with remote sensing instrumentation offer numerous opportunities in disaster related situations. when uavs acquire photogrammetryready data with appropriate imagery metadata, the capabilities of uavs for disaster research and management can be further realized. the other application that as popular as volcanic monitoring is the coastal monitoring using an unmanned aerial vehicle [4]. the uav has managed to monitor an environmental change due to typhoon morakot disaster by using aerial photographs and digital elevation model (dem) [5]. in addition to military of united states also have used uav that was flown from guam to monitor the condition of damage of the fukushima daiichi nuclear power station after the massive earthquake in eastern japan in march 2011 [6]. the unmanned aerial vehicle will fly and monitor the condition along the coast line, also mapping the area for mitigation purpose as needed. a properly equipped uav can cover a very large area with varied types of sensors, and can be deployed to disaster areas quickly, or flown there from a distant location if a satellite equipped. uavs have the advantages that they are more easily re-assigned, reconfigured, and upgraded to take advantage of different payloads or new sensor technology [7]. following the disaster occurrence data acquisition becomes critical inplanning and executing the response action. the main requirements for the data acquisition are real time/rapid processing, multi temporal resolution and high spatial resolution. in addition to the operational requirements, this also necessitates the need for speedy automated processing techniques [8]. however, study on uav for monitoring as well as mapping of disaster areas has never been reported. in this research, a fixed wing uav for both monitoring and mapping of disaster areas was developed. with a map of the disaster areas, information about the condition of the affected areas can be obtained more accurately. the purposes of this research are mapping using unmanned aircraft, doing a live-view monitoring, and develop a disaster mosaic photo maps of monitoring results. which took place on depok beach in yogyakarta province, indonesia. ii. method this study began with determine the mission that will be conducted by the uav, where the mission is monitoring depok beach areas, parangtritis, yogyakarta. then continued with choosing the electronic components of the aircraft that suitable to the mission. the next step is determine the waypoint of the monitoring area. it is estimated that the aircraft has endurance of 12-15 minutes, so that the length of the waypoint adjusted to the ability of the aircraft to fly. the next step is to run the mission to take photographs and video. video can be displayed in a computer screen as live-view while the aircraft on it's flight. meanwhile, the photos from the monitoring's results will be processed into a mosaic map, then the map was analysed for studying potential disaster ought to occur so that the disaster management strategies can be developed based on the observation of the disaster map. figure 1 shows the set up of the research. figure 1. research set-up g. nugroho et al. /j. mechatron. electr. power veh. technol. 06 (2015) 83-88 85 the aircraft is flown by following the waypoint that has been plotted on the disaster region. while on its flight mission, uav recorded the monitoring video and took pictures, then sent those to ground control station (gcs), it means that uav can provide live-view monitoring to the monitor on gcs. the uav's crews and expert team in disaster management could monitor the disaster area directly via the live-view video. when uav has finished its flight mission, the video or photos that have been recorded could be processed to be a disaster map. iii. results and discussion a. developed uav specification the uav that is used during this research (in figure 2) has an avionic system that consists of: autopilot module, gps, servo motor, dc motor, camera, a/v sender 1.2 ghz, a/v receiver 1.2 ghz, telemetry 900 mhz, remote control and remote receiver 2,4 ghz, and software as ground control station. for the airframe, flying wing type was used. specification of the fixed-wing uav is listed in table 1. b. flight data while on its mission, the uav provides flight data such as position tracking, altitude, groundspeed, and airspeed that illustrated uav's maneuver and characteristic. for takeoff and landing, the uav used manual flight mode controlled by a pilot. for cruise flight to conduct the monitoring mission, the uav used automatic mode controlled by an onboard autopilot system. figure 3 shows the data provided by the uav during autonomous or automatic flight test before conducting disaster area monitoring mission. this flight test is conducted with reference speed of 60 km/hour and altitude of 90 meter above sea level. figure 3(a) shows that the uav could be flight on its waypoint. the yellow line indicates the given waypoint that could be followed by table 1. developed fixed-wing uav specification parameter unit empty weight 3 kg payload 1.5 kg wing span 2.2 m power supply 5,000 mah endurance 15 minute figure 2. developed flying wing airframe uav (a) (b) (c) (d) figure 3. flight data; (a) plane tracking; (b) altitude; (c) groundspeed; (d) airspeed g. nugroho et al. /j. mechatron. electr. power veh. technol. 06 (2015) 83-88 86 blue line that indicates the plane's tracking. figure 3(b) shows the altitude graphic from uav while on its flight. the uav could maintain its given altitude on 90 meter above sea level. the uav's groundspeed in figure 3(c), and airspeed in figure 3(d) became very various due to its heading respect to wind's flow direction. from the flight test result, it can be concluded that the developed fixed wing uav able to fly autonomously to follow the given flight path and able to maintain its stability. during flight, the uav will suffer external disturbance from wind gust. robustness against wind effect may be realized by adopting appropriate control schemes for uav such as gain scheduling control [9]. to develop a high performance controller for a fixed wing unmanned aerial vehicle, dynamics model of the aircraft has to be derived. for a fixed wing uav, a dynamical model can be used to formulate appropriate flight control design, which is robust against wind disturbance [10]. c. live view monitoring live-view monitoring takes place when the aircraft was on a mission. video obtained by camera then transmitted to a computer in the ground through av sender/receiver. the print screen of live view monitoring can be seen in figure 4. d. image processing the results of this research are aerial photos and aerial videos. aerial videos, that can be seen from the visualization of ground control station (gcs), are presented in the form of live view and data recorded on the camera's memory card. whereas, aerial photos can be seen from the data stored in the memory card of the digital camera, and it will be used as a mosaic. the aircraft flies autonomously following the preset trajectory at the altitude of 150 m above sea level to obtain high quality of photo. with the focus lens of the camera which is 2.7 mm, it is determined that the scale of the aerial images is 1:55,555. the experiment was conducted with the length of waypoint of 5.0045 km and speed of aircraft is 15 m/s. while the mission took place, the signal of the aircraft is 88-98 %. telemetry system runs well and av-transmitter can send audio-video data that can be seen on the ground control station computer. figure 5 is waypoint used in this experiment. to scan area that will be mapped, the flight path was made sinusoidal. with this flight scenario, will be obtained overlap video or photo so that no black spot on the resulting map. the aircraft could follow waypoints. the waypoints are shown by yellow line and the plane’s tracking is shown by the blue line. from the figure 5, it can be seen that the blue line can follow a yellow line. shape of waypoint made like on the figure 5 so that all areas can be covered. the experiment’s data, which is a video format (mp4), must be converted to image/photo format (jpeg). the conversion from mp4-format to jpeg-format has been done using video to jpeg converter software. the 59 fps video converted using extraction mode of one photo every 10 frames to obtain overlap the photo to eliminate blank areas. the sample results of the extraction can be seen in figure 6. the images that have been extracted are then processed based on the workflow on agisoft photo scan software. the processing steps are align photo, build dense cloud, build mesh, and build texture. 1) align photo at this step, the images that have been extracted will be sorted. the process is based on the overlap (side lap and end lap). the results are figure 4. live view monitoring figure 5. waypoint on the mission figure 6. result of image extraction from video g. nugroho et al. /j. mechatron. electr. power veh. technol. 06 (2015) 83-88 87 images that consist of sparse point cloud and sorted images that forming waypoint. there are 391 photos from the extraction result. the result of align photo can be seen on the figure 7. 2) build dense cloud the next process is to build dense cloud. in this step, the sparse point cloud will be processed to be dense cloud. the results of this process can be seen in figure 8. 3) build mesh from the build dense cloud process, the result is a dense point cloud. the next phase is sealing pixel images and merging point photos through the sub menu build mesh. the result of the build mesh is a still rough textured mesh as shown in figure 9. 4) build texture to be used as a mosaic map, build texture process should be run to obtain a finer texture field. results of the build map mosaic texture used for various purposes. figure 10 is the final result of the process. mosaic photo that is shown in figure 10, formed by several photos, which is aligned based on overlap (end lap and side lap) of each photo. there are three main criteria to evaluate the quality of the aerial map, which are distortion, black spot and the clarity of the map. the distortion caused by the moves of the object and also focus of the camera lens is not appropriate. for eliminate the distortion, adjusting the altitude of the aircraft precisely is needed to obtain an appropriate focus lens. black spot is caused by the absence of an image in the area. this is caused by some cases, for example, the absence of overlap in the photo, it is caused due to an error in determining the trajectory in the scanning area to be mapped. the second cause is the movement of the camera caused by aircraft stability. to overcome these conditions, the aircraft must be designed to have high stability or the camera equipped with a gimbals. the third cause is maneuverability of the aircraft. the aircraft must be designed to have good maneuverability. the clarity of the image is caused by several factors such as the quality of the camera, the aircraft speed and vibration. to obtain a clear map, it should use high resolution camera, and also the aircraft is need to be designed with low stall speed and minimum vibration. quality of the map can also be enhanced in the process of object detection as well as in the process of image processing. object recognition system used computer vision that is implemented on remote controlled weapon station can be considered. this system will make it easier to identify and shoot the targeted objects automatically [11]. e. map interpretation from the map that has been formed, it can be seen that the waves looked calm and still at the shoreline. there is a green area (trees, grasses and shrubs) around the coastline and a runway right on the edge of the shoreline. however, there figure 7. sorted images that forming waypoints and sparse point cloud figure 8. the results of build dense cloud figure 9. meshing result on build mesh process figure 10. final results of the mosaic photo process g. nugroho et al. /j. mechatron. electr. power veh. technol. 06 (2015) 83-88 88 is only one road to access the runway, in the form of a small road. the resident’s house looks close to the shoreline. based on the interpretation and analysis, some information that can be drawn from the mosaic map which is useful for mitigation purposes are: 1. lack of evacuation routes. there is only one evacuation route. it is better to add evacuation route, so that the new route can break crowd. 2. the residential areas too close to the coastline. this is quite dangerous because when there is a high tide or waves of tsunami, residents living near the beach did not have enough time to avoid. 3. lack of vegetation around the shoreline which resulted in abrasion by the waves of the sea. 4. the increasing number of shrimp farms around the coast, resulting in a reduction in the green zone because clearing land in the green zone. iv. conclusion based on the results of this research, it can be concluded that the avionics and airframe systems that have been selected and developed can work and communicate with ground control station (gcs) properly. the uav can conduct monitoring of area with flight altitude of 150 m and average speed of 15 m/s. this developed disaster monitoring system can generate a live video which is sent to the gcs so that the operator can monitor conditions of the area directly. besides that, the result of disaster monitoring system also can generate mosaic photo of disaster which is composed from several aerial photos and provide flight data of its mission. based on the form of output which is a disaster map, it is expected that the disaster management; for example determining evacuation route and damage assessment, can be done faster. furthermore, recovery can be done immediately and accurately in accordance with the developed disaster management strategies based on the observation of the disaster map. references [1] l. c. trost, "unmanned air vehicles (uavs) for cooperative monitoring", sandia national laboratories, california, pp. 3, 2000. [2] v.v. klemes, “coastal and environmental remote sensing from unmanned aerial vehicles: an overview”, journal of coastal research, vol. 3, n0. 5, 2015, pp. 12601267. [3] c. hackney and a.i. clayton, “unmanned aerial vehicles (uavs) and their application in geomorphic mapping", geomorphological techniques, chap. 2, sec. 1.7, 2015. [4] s. m. adams and c. j. friedland, "a survey of unmanned aerial vehicle (uav) usage for imagery collection in disaster research and management", 9th international workshop on remote sensing for disaster response, stanford university, september 14-16, 2011. [5] t-y. chou et al., "disaster monitoring and management by the unmanned aerial vehicle technology", wagner w., székely, b. (eds.): isprs tc vii symposium 100 years isprs, vienna, austria, july 5-7, 2010, iaprs, vol. xxxviii, part 7b, 2010. [6] s. ikenoza et al., "small unmanned aerial vehicle system for advanced informationgathering", hitachi review vol. 62 (2013), no. 3, 2013. [7] a. afzal et al., "uav based monitoring system and object detection technique development for a disaster area", the university of tokyo, institute of industrial science, tokyo, 2008. [8] m. arthur et al., "rapid processing of unmanned aerial vehicles imagery for disaster management", fig working week 2012, rome, italy,6-10 may, 2012. [9] m. q. abdurrohman et al., "a modified gain scheduling controller by considering the sparseness property of uav quadrotors", journal of mechatronics, electrical power, and vehicular technology, vol. 06, no.1, 2015, pp. 9-18. [10] fadjar r. triputra et al., "nonlinear dynamic modeling of a fixed wing unmanned aeral vehicle: a case study of wulung", journal of mechatronics, electrical power, and vehicular technology, vol.06, no.1, 2015, pp. 19-30. [11] m. mirdanies et al., "object recognition system in remote controlled weapon station using sift and surf methods," journal of mechatronics, electrical power,and vehicular technology, vol. 04, no. 2, 2013, pp. 99-108. mev j. mechatron. electr. power veh. technol. 07 (2016) 35-48 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.35-48. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. review on the application of physiological and biomechanical measurement methods in driving fatigue detection kadek heri sanjaya a,*, soomin lee b, tetsuo katsuura c aresearch centre for electrical power and mechatronics, indonesian institute of sciences 2nd floor, 20th building, komplek lipi, jalan cisitu no. 21/154d, bandung, indonesia bcenter for environment, health, and field sciences, chiba university 6-2-1 kashiwa-no-ha, kashiwa, chiba prefecture 277-0882, japan chumanomics laboratory, graduate school of engineering, chiba university 1-33 yayoi-cho, inage-ku, chiba-shi, japan received 23 march 2016; received in revised form 30 may 2016; accepted 30 may 2016 published online 29 july 2016 abstract previous studies have identified driving fatigue as the main cause of road traffic accidents, therefore, the aim of this literature review is to explore the characteristics of driving fatigue both physically and mentally as well as to explore the technology available to measure the process of fatigue physiologically. we performed e-searching in the field of fatigue detection methods through keywords tracking. the instruments studied have their own strength and weakness, and some are intrusive while the others are non-intrusive. the accuracy and stability of measurements are also varied between those instruments. in order to create more reliable fatigue detection methods, it is necessary to involve more instruments with an inter-disciplinary approach. our intention is to make this study as a stepping stone for a more comprehensive in-vehicle real-time man-machine interaction study. such study will not only be useful to prevent traffic accidents but also to bridge man and machine communication in the vehicle control along with developing newer technology in the field of vehicle automation. keywords: driving fatigue; physiology; biomechanics; man-machine interface. i. introduction one characteristic of modern life in humans is the high mobility as our houses are mostly far from our workplaces. the higher income in developed countries came from greater productivity which in turn requires people to move faster and farther. thus, transportation has become an important aspect of human daily life. the present generation has been lucky to inherit a great leap in technology development since james watt’s invention of the steam engine in the 18th century which triggered the industrial revolution [1]. technology allows humans to move more efficiently without relying too much on biological muscles for transportation. a developing country like indonesia has undergone a dramatic change in human mobility. the country’s ambition of progressing from a traditional agricultural society where most people live in the rural area to become an industrialized country has created staggering urbanization problem [2]. unlike in the rural area where agricultural workers have their activity nearby their living place, in the urban area most people live far away from their workplace, therefore, the need for transportation has become very crucial. thus, transportation has been a priority in the development program in indonesia [3]. by taking the long history of human evolution into account, driving a vehicle which is a more advanced development of tool culture is a new thing, therefore, how well the human body adapt to this relatively new activity has been drawing a great amount of research interest. one most important issue of engine-propulsion locomotion such as vehicle transportation is a large number of accidents. who reported that the number of * corresponding author.tel: +62-22-2503055 e-mail: kade001@lipi.go.id http://dx.doi.org/10.14203/j.mev.2016.v7.35-48 k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 36 traffic accident-related death in the world in annually is more than 1 million people with the highest rate occurred in developing countries [45]. road traffic accidents have cost every country the loss of between 1 to 3% of gross domestic product (gdp) [5]. as shown in figure 1, indonesia has higher road traffic-related death rate than its neighbors. a report suggested that traffic accidents are the third cause of fatalities after myocardial infarction and tuberculosis [6]. most of the victims are between 22 to 50 years old which is in productive age, thus, those accidents may also lead to poverty [6]. one of the major cause of road traffic accidents is driving fatigue [7-11]. fatigue has various symptoms and causes. the causes may come from activities before driving such as sleep deprivation [10-14], during driving in longer duration [7,15] and driving at nocturnal time [12], or environmental effects such as vibration [17,18], temperature, humidity and noise [14]. the symptoms of fatigue are both physical and mental. physical fatigue has been heavily linked with muscular fatigue when muscle shows a decrease of capacity to generate maximal force exertion [9,19-21] due to repetitive movements with excessive load [18]. some studies distinguish visual fatigue and mental fatigue, as visual fatigue especially occurs in the eye [15], and old opinion with dualism concept tend to separate physical and mental processes of fatigue [19]. while monism view, which is widely adopted today, presumes that the universe consists of matter and energy, and that mind is an inseparable thing from the body [19]. fatigue is often accompanied by drowsiness [9,13,24-28], thus, drowsiness is often used as a variable in driving fatigue detection. despite great interest from many researchers to study fatigue, there is still no consensus on its definition that is widely accepted [24, 29]. the driving fatigue study has been widely recognized as important with regard to the effort to cut the number of traffic accidents. most of the earlier studies on driving fatigue detection gave little attention to human as an organism as they heavily focused on the engineering point of view. nevertheless, the technology development has allowed us to better understand physiological processes inside a human body based on clinical measurements [30-31]. we consider fatigue as a physiological phenomenon with some biomechanical characteristics which is measurable with techniques now available. the study of human physiology has involved multidisciplinary approach as it discusses the complex system inside a human body [23, 32]. fatigue is also observable through human motion and forces exertion, therefore, a biomechanical approach is also necessary to understand fatigue, as biomechanics is the discipline that concerns about human motion and structure [33-35]. the aim of this literature review is to explore physiological and biomechanical measurement methods available for application in driving fatigue detection studies. we expect that the knowledge attained in this review will be useful as a base for further studies such as to develop instruments and procedure for fatigue detection and intervention and their in-vehicle application. figure 1. the number of road fatalities per 100,000 inhabitants (upper) and total road fatalities in 2012 (lower) [4]. south-east asia has the highest number of road fatalities with indonesia as the country with most road fatalities in asean region k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 37 ii. method in this section, we describe the literature searching methods and the systematic of the discussion section. we explain the process taken from literature searching to article writing. we expect the process to enable this article to find opportunities and challenges in the driving fatigue research more throughly. a. literature searching process we performed literature searching through esearching, which is more helpful than conventional printed book-searching as the latter is more time-consuming and may miss significant information on the references such as citation number [29]. we used a new approach as described in a previous study [30], which is different from the conventional searching, we limited the searching on formal articles, by using certain keywords. the keywords used were driving, fatigue, electromyogram (emg), electroencephalogram (eeg), electrocardiogram (ecg), and eye tracker. we limited the literature searching with two categories: the latest studies, such as in the last two years, and classical studies with a large number of citation. in an effort to describe driving fatigue from an interdisciplinary point of view, it is necessary to include as many approaches as possible, especially based on their methods [31]. therefore, we grouped the collected references based on their measurement methods. we performed reference list checking [29], however, we did not conduct any quantitative assessment on the references. b. writing systematics in principle, we intend to use this literature review to study the state of the art of driving fatigue detection, to gather the knowledge of whatever other researchers have done in the related field, and whatever problem necessary to solve in the future research [31]. with a great understanding of the research gap in existence, we can formulate a good planning for future study. in the discussion part, we start by describing the physiological processes of fatigue. in turn, we will relate these processes to the instruments required to measure those phenomena. basically, the instruments record signals generated by the body during fatigue. these electrical data can give information on the fatigued driver condition both real-time or non-real-time. in a literature review, such as a review of methods like this article, in the last part, it is necessary to summarize and synthesize our analyses [32]. in this part, we summarize the current technology available for driving fatigue detection and the possibility of future development of driving fatigue study. iii. results and discussion the driving tasks are divided into two, namely primary and secondary tasks. the primary task is the driving the vehicle itself [40-41], which includes activities such as holding the steering wheel, pushing the gas pedal, and braking. the secondary tasks are varied, such as looking at indicators, using entertainment facilities such as audio-video, adjusting air-conditioner, etc. some studies suggest that the greater automation in a vehicle will likely lead the driver to get more engagement with the secondary task [40-42]. while the primary task is the main causes of both physical and mental fatigue during driving, the secondary task has been associated with mental fatigue [10, 29]. a. fatigue occurrence in driving a vehicle the easiest way to explain driving fatigue occurs is by exposing the driving activities. upon entering a driving workstation, the driver adjusts the seat place to make sure that all the controllers for the primary task are reachable. a welladjusted seating posture may prevent a driver from fatigue [36]. to judge whether the position is optimum, the most common sensory involved are visual sensory [10, 23, 44] to search the controllers, somatosensory [23, 45] to confirm the controllers are reachable, and to certain degree vestibular sensory [23, 46-47] to judge the good balance of the posture taken. all the information from those sensory receptors is processed at the brain to make the driver aware of his position. when the driver turns the vehicle on, the engine emits sound and vibration. then the sound and vibration are transmitted through the structure of the vehicle and received by auditory sensory and somatosensory [48-49]. by pushing the gas pedal, the driver will have an interaction with the vehicle, and any action taken on the pedal gives feedback which in turn received by sensory receptors, followed by processing the information in the brain. thus, a communication loop exists. the driver performs visual scanning on the surrounding environment before moves the vehicle. once the driver concludes that it is safe, the driver moves the gear stick and pushes the gas pedal, then the vehicle is accelerating. while driving, the driver receives the exact information on the speed from the speedometer, however, the k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 38 visual information of how the vehicle moves about its surrounding augmented by feedback from the sound and vibration also give significant cues for him [43]. it is common that the driver will have his attention mainly in front of the vehicle, however, inattentiveness to the surrounding area other than in front may increase the risk of accident, thus, they need to dedicate some attention to avoid side or rear collision [42]. most fatal accidents occur during speeding. driving a vehicle in a high-speed means the driver has the shorter reaction time to react, thus, higher alertness is important [10, 49-52]. figure 2 shows what may and baldwin (2009) suggested on the classification on driving fatigue based on its causes [22]. they divided fatigue as sleep-related (sr) and task-related (tr) fatigue. sr fatigue includes lack of sleeping before driving [10, 12-14, 53] and driving at the time in circadian rhythm/daily life cycle when people usually sleep, such as midnight [15-16, 53]. the driving task and environmental condition are the causes of tr fatigue. the environmental aspect includes temperature, humidity, noise [14], illumination [22], and vibration [17, 54-55]. a study reported that excessive noise increases fatigue occurrence probability as measured by cardiovascular and hormonal activity analysis [49]. fatigue and sensory alteration are also affected by vibration inside the vehicle [17, 55]. tr active fatigue is the most common fatigue suffered by the drivers. mental and physical overload during driving such as prolonged driving for more than two or three hours [7, 9, 15], driving in traffic jam, multi-tasking driving, driving in poor visibility environment [22], or overload in mental processing task due to excessive information [9, 57] are the causes of tr active fatigue. tr passive fatigue is caused by underload due to vehicle automation, monotony [25, 58], or highly predictable driving task [22]. as shown by the dashed line in figure 2, both tr active and passive fatigue can worsen sr fatigue. fatigue occurrence is either physically or mentally or both in a concurrent way. physical fatigue has been associated with the decreasing capacity to exert maximum force output [9,19,5960], as there is a failure of processes either within the central nervous system (cns), neural transmission from the cns to the muscle, or within individual muscle fibers [55]. physical fatigue is mainly included in tr active fatigue such as prolonged sustained physical activity with force exertion [61-62] or higher frequency of cyclic activity in the longer period [57]. some studies distinguished mental fatigue and visual fatigue [9,64], however, in reality, these two things are inseparable. in this article, we consider visual fatigue as part of mental fatigue as some studies referred mental fatigue as a consequence of visual fatigue [7, 10, 13, 52, 65]. mental fatigue can be inflicted by both mental and physical processes [9, 29], and classified in both tr active and passive fatigue. a fatigued driver shows many different characteristics from a non-fatigued person. some of the visible characteristics are body movement [5,9,12,24,25,51,66], facial expression [5,8,12,26] and sweating [37], whereas the invisible ones related to physiological processes inside the body, such as muscular activity [9,18], heart rate [15,16,44,67] and blood circulation [68-69], brain activity [9,13-14,29], and hormonal changes [20,51] or psychological condition [23]. in many cases, fatigue is accompanied by drowsiness which is commonly characterized by frequent yawning [9,15,24-27]. b. muscular fatigue all the physical working during driving are performed with muscular activation that produces some movements. these movements are varied in requirements of force, speed, and vectorial translation. the movement is initiated in the smallest functional unit of the muscle called as the motor unit [33, 70-71]. when a muscle contracts, the central nervous system (cns) recruits motor units as a voluntary effort [61-62, 70]. increased tension to generate force output is achieved by two strategies: increasing stimulation rate of a single motor unit or recruitment of more motor units [27]. muscle fiber, just like any neuron inside a human body maintains negative potential at about 80 mv from its surrounding by exchanging ions [70]. this potential is called motor unit action potential (muap) and recorded as representative of muscle activation [33, 71-72]. this electrical indication is then measured by figure 2. driving fatigue classification by may and baldwin (2009), based on its causes [28] k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 39 surface electromyogram (semg), as shown in figure 3. two most important features for semg signal detection are excitation of muaps and their firing rate [68]. muscular fatigue, in general, is included in tr active fatigue. based on processed semg signals, there are two ways to analyze muscle fatigue, namely spectral analysis as shown in figure 4, and emg/force relation analysis [33, 70-73]. fatigue muscle is caused by depletion of energy generating substances, accumulation of metabolic waste product, failure in muscular contractile mechanism from cns to the muscle, and disturbances in homeostasis [54] since a contracting muscle restricts blood flow, thus reduces oxygen supply [65]. figure 5 shows that when a person exerts a constant force in a certain period of time, in power-frequency diagram, the frequency decreases since the biochemical process results in the acidic products formation which reduces the conduction velocity of the muaps on the muscle membrane [68]. recruitment of more muaps also means emg activity-force production level correlation line would also shift toward the left side since fatigued muscle has its force output decreasing while emg activity is increasing, as graphically represented in figure 7 [59,70,74]. median frequency (mdf) has been suggested as the most common data used for muscle fatigue index calculation, as illustrated in figure 5 [7071]. other suggested mean power frequency (mpf) as the most useful tool to quantify muscle fatigue, as illustrated in figure 6 [59,74]. the measurement of power-frequency relation usually performed at certain time points in a session, such as the start, middle, and end of the session, in off-line mode. emg-force relation requires the use of force measurement instruments such as load cell or force plate. this method has greater potential than frequency analysis for real-time fatigue detection analysis, as long as there is sufficient information on the normal driver and fatigue driver characteristics, as inter-subject variability is common in emg measurement. based on this type of measurement, muscle fatigue is identified as a two phase-process, the first when emgforce in linear relation and the second when the force decreases faster than the emg signals, as graphically illustrated in figure 7 [53]. moshou et al. (2005) proposed to use of wavelets coefficients analysis to detect dynamic muscle fatigue [73]. wavelets is very common used in analyzing signals that are time varying and non-stationary. they developed selforganizing map (som) to identify and measure driving fatigue. the som works by dynamically visualizing the approximate values of the wavelet coefficients. this method offers advantages in sensitivity to detect fatigue and recovery. however, this method needs further development to be widely accepted. in most studies on driver fatigue detection, emg has rarely been given attention. there are various reasons. emg electrode needs to be attached to the skin, thus, it is naturally intrusive [11] and requires an understanding of which muscles would fatigue in certain movements since fatigue is different in each contracting muscle. the attachment also figure 3. semg ag/agcl bipolar electrode (upper) and semg electrodes attachment onto the skin surface to measure back and abdominal muscles activation (lower) figure 4. spectral analysis of semg data: vertical axis shows magnitude (v2/hz), horizontal axis shows frequency (hz). total power is the area under the power spectrum curve, peak power is the maximum value, mean power frequency (mpf) is the average of power spectrum, and median frequency (mdf) is the line that divides the area into two equal parts [68] k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 40 requires hair removal and skin cleansing [68] and sweating as well as subcutaneous fat will decrease the measurement accuracy [74]. with the knowledge of the current technology, it seems difficult for emg to be used for real-time invehicle fatigue detector. nevertheless, emg is a very powerful and accurate tool to measure fatigue for laboratory experiment, especially to learn about neuromuscular processes in relation with reaction time study. c. fatigue detected from heart rate the most important function of the heart is to pump the blood through the blood vessels in the circulatory system, where the blood supply the body with oxygen and nutrients as well as playing an important role in assisting metabolic waste removal [75]. since the three substances are closely associated with the occurrence of fatigue, the heart is very crucial in fatigue study. heart rate (hr) is defined as the number of beats produced by the heart in one minute, while heart rate variability (hrv) is a terminology to describe the physiological phenomenon where temporal intervals between consecutive heartbeats are not uniform, as illustrated in figure 8 [79, 80]. fatigue has been associated with electrolyte and acid-base disturbances that affect hr which is measured by electrocardiogram (ecg) [17]. while extreme exercise increases hr [78] and excessive fatigue after arousal may result in exhaustion, this case is rarely observed in driving fatigue. therefore, most driving fatigue studies employing ecg are focused on drowsiness as the consequence of fatigue. drowsiness, on the figure 7. fatigue condition is characterized by lower force exertion level at the same muscle activation. here fatigue condition is compared with three types of muscle activation (concentric, static/isometric, and eccentric), as well as with the subjects considered outside normal people, such as trained (athlete) and atrophy (muscularly weak person) [68] figure 6. during a muscle activation trial session, the mpf value was lower in fatigue condition both by comparing dynamic movement and static isometric posture [76] figure 5. as the muscle contracts in longer duration, at the end session of the trial, the mdf value is lower compared to that at the middle and the beginning of the trial [71] k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 41 figure 9. hrv of a driver who falls asleep (upper) and who yawns often (lower). in sleepy subjects, hrv is increasing [82]. further spectral analyses arenecessary to detect drowsiness more accurately contrary, decreases hr [67]. thus, we may conclude that sr fatigue decreases hr whereas tr active fatigue increases hr. figure 9 shows the increasing hrv due to drowsiness [79]. on the other hand, excessive fatigue after arousal decreases hrv [46]. autonomic nervous system (ans) whose role is regulating unconscious control system of the internal organ such as the heart rate, changes during stress, fatigue or drowsiness [16-27]. ans consists of sympathetic and parasympathetic nervous systems. hrv is representative of the balance between the two nervous systems [10]. fatigue or drowsiness have been reported to be characterized by greater parasympathetic nervous activity accompanied by a decrease in sympathetic nervous activity [14, 16, 27]. with regard to hrv, drowsiness is shown by faster hrv rhythm or high-frequency band (hf, 0.15 to 0.4 hz), on the contrary to slower hrv rhythm or low-frequency band (lf, 0.04 to 0.15 hz) which indicates alertness and wakefulness [10]. in general, a decrease in lf and lf/hf value which is associated with sympathetic nervous system activity[80], has been used for indicators of fatigue [14, 27]. ecg measurement has been reported to the most reliable for fatigue detection [5, 67, 86]. however, as it requires electrode attachment to the skin, it is intrusive [5, 67], hence, it is uncomfortable to be used during driving. ecg is also largely affected by environmental variables such as vibration and temperature [14]. to overcome these weaknesses, a non-contact hr and hrv measurement using photoplethysmogram (ppg) has been proposed [18, 69]. ppg is a dedicated light source equipped with light emitting diode (led) and phototransistor (pt). the light from the led to the skin is being reflected back to the pt, and the recorded signal is then analyzed [14]. ppg may be placed on areas such as the finger tip or the forehead. the instrument is able to detect any blood pressure changes in the blood vessels on the face or other parts of the body that is not obstructed. another method proposed is by placing ecg electrodes on the seat and the steering wheel, and then the less accurate data from those electrodes are combined to produce reliable data [64]. d. fatigue detection with eeg fatigue, drowsiness and low vigilance have been reported as the greatest safety hazard in driving [23]. fatigue condition inhibits the nervous system and decreases cognitive abilities [15, 44]. mental fatigue, as one component of fatigue, is a subjective feeling of tiredness which causing the decreasing of motivation to make an effort for certain activity [23, 59], due to sustained mental and/or physical task which requires high alertness [20] or boring task [23], which impairs attention. the occurrence of an error during performing a task also increases the likeliness of mental fatigue as measured by reaction time [44]. the easiest and cheapest way to measure mental task load is a questionnaire, such as nasa task load index (nasa-tlx) [82] or karolinska sleepiness scale (kss) [46], however, it cannot be applied for real-time measurement, and subjects need to be isolated from any psychological noise that may deviate assessment [82]. the subjective scale also needs a larger number of subjects to validate the results. therefore, eeg which measure brainwave is considered as more accurate and objective to measure mental fatigue in real-time [9], as it is sensitive enough to detect any changes with an update in seconds [23]. for fatigue detection, eeg stability measurement was reported to achieve 85% to 87%, greater than eye tracking, figure 8. ecg electrodes placement on the trunk. ecg normal sinus rhythm generates p wave, qrs complex, and t wave [91]. heart rate (hr) is calculated from the number of p or r in one minute. p-p or r-r intervals are representative of heart rate variability (hrv) [76, 92] k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 42 but lower than ecg [5, 53]. during fatigue, eeg power decreases into low-frequency band [9]. eeg is able to measure both sr and tr fatigue. figure 10 shows eeg electrodes placement and the types of brainwaves used in fatigue analysis. the rise of spectral power in frontal theta (theta wave, 4-<8 hz [83]) and parietal alpha (alpha wave, 8-13 hz [11, 87]) have been linked with mental fatigue [23]. other study suggest that decrease of beta wave (13-30 hz [83]) in the prefrontal, inferior frontal, posterior temporal, and occipital lobes accompanied by increase of alpha wave in the frontal, central, posterior temporal, parietal, and occipital lobes area of the brain as indicators of mental fatigue [9]. alpha wave is the most common variable used to detect fatigue as it is considered to be the most reliable [9], furthermore alpha wave measured from the occipital and central areas are indicators of drowsiness [8]. indices used to measure mental fatigue include the comparison between the summation of alpha and theta to beta [15], even-related potential (erp) [82], reaction time [60], and task load index (tli) which is based on the ratio of frontal midline theta to parietal alpha [82]. eeg is an intrusive instrument, and to attach its electrodes on the head, some cleaning-up procedure is necessary, especially to reduce impedance. the risk of signal noise and sensor failure during measurement are high [23]. furthermore, while eeg can detect drowsiness easily, to use eeg for mental fatigue detection in a fully alert driver is still a great challenge as fatigue is a complex and non-linear condition [29,51]. thus, to develop a model that is more representative to mental fatigue by involving eeg combined with other methods is necessary for future study. e. fatigue detection through facial expression non-contact fatigue detection methods include video analysis of facial expression [5, 9, 26, 89], such as head [5], mouth [15, 24, 26], and eye movements [7, 58, 90]. behavioral studies also observe variables like facial activities, postural adjustments from original position, and hand movements relative to the body [45]. since these methods measure attention, fatigue is not separated from drowsiness as both produce hypovigilace. the study on cortisol, which is the stress hormone, found the association of fatigue and drowsiness [13, 25]. in general, facial expressionrelated fatigue detection methods are mostly intended for sr fatigue. the most important feature of head movement in 3d motion tracking is the orientation of the face as it signifies attention [26, 89]. normal driver in full alertness has his face oriented frontally with a good view on important indicators through his peripheral vision. a fatigued driver, on the contrary, will likely to have more head movements either flexionextension or rotation. yawning, which is characterized by a wider mouth opening and deep inhale, has been used as both drowsiness and fatigue indicator in many studies [21]. fatigue detection through lip movement possesses so many challenges, such as to distinguish yawning from normal speaking [21] and to distinguish yawning due to fatigue or drowsiness from contagious yawning which associated with the mirror-neuron system [51]. to overcome these problems, one study suggested the identification based on concurrent stretching or extension of the neck [51], the other study suggested by calculating the time of mouth opening [63]. eye movement is the most common facial expression employed for fatigue detection since it reflects the neurological condition [12, 46].while human vision affects both mental and physical fatigue development, a stress developed in the eyes to some researchers is classified as visual figure 10. the international 10-20 system of eeg electrodes attachment on the scalp (upper)[87]. a= ear lobe, c= central, f= frontal, fp= frontal polar, o= occipital, p= parietal, t= temporal. the three types of brainwaves commonly used for fatigue analysis: transition from beta-wave to alpha-wave shows drowsiness and transition from alpha wave to theta-wave shows microsleeps (lower) [53, 87] k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 43 fatigue [9, 64], despite it refers to the site of fatigue, and not to the process. measured eye movement components are duration and frequency of eye blink/closure [7,11,15,24], and saccadic movements: dynamic, glissadic, and static movements [85]. those components are measured by tracking and detection of pupil [65, 91, 92] or iris [85] movements. other method is intrusive: the use of electrooculogram (eog) with electrodes should be attached to the eyelid skin [81]. fatigue is detected from increasing blink rate and decreasing of saccadic peak velocity/magnitude [7, 90]. a continuous detection of pupil movements allows researchers to measure eyelid closure/opening, gaze, and face orientation [62]. eye closure is measured from pupil size and face orientation is measured by comparisons on the two pupils based on calculation of distance and size ratio [62]. percentage of eye closure over time (perclos) [8, 11, 53] and the average of eye closure speed (aecs) [8, 53] have been suggested as the most representative eye movement parameters in detecting fatigue. eye tracker instrument has advantages in that it is non-intrusive, therefore, more comfortable to the user, and the user can mount it in various areas inside a vehicle for real-time detection. however, compared to ecg or eeg, it is less accurate [46], and less stable, with the rate of just 59% as compared to 85% and 97.5% of eeg and ecg respectively [5]. this device is only able to measure a person with normal or corrected-tonormal vision without any saccadic abnormality. the use of infra-red for illumination of eye tracker device has been suggested as it is able to detect eye movement in a various light background and almost invisible to the driver’s eyes [86]. f. combining the measurements in general, based on their contact with the human body, the instruments can be classified into intrusive and non-intrusive methods [5]. as shown in figure 11, intrusive methods include emg, eeg, and ecg, whereas non-intrusive methods include facial and eye tracking. force measurement instruments can be non-intrusive if placed under the seating cover, or intrusive such as pressure sensors attached to the finger tip. such condition is also applied for ppg, as it is contactless if used for forehead scanning, whereas it is intrusive if placed on the fingertip as in conventional plethysmogram. intrusive methods are generally more accurate, however very susceptible to physiological noise such as sweating, or especially emg the noise usually comes from subcutaneous fat. these methods are very good for a laboratory experiment. to be applied in a field test, a great challenge comes from material and placement design with regard to the human body. ecg application requires fatigue threshold definition since sr and tr fatigues have very contradictory characteristics. non-intrusive methods such as eye and body motion tracker have challenges in accuracy and reduction of environmental noise effects. each method has its own advantages and disadvantages, therefore combining those methods will result in a more reliable measurement [11, 14, 18, 53] as fatigue has nonspecific symptoms. for example eye movement measurement with an eye tracker should be accompanied by emg recording of oculomotor muscles, and either yawning or facial expression tracking should be accompanied by emg recording of facial muscles. in accordance with the technology development, some disadvantages of those instruments may be overcome by newer inventions either in materials or techniques. the different characteristics will also enable designers to create more alternatives for both real-time and non-real-time fatigue detection methods. furthermore, future studies on fatigue detection methods should not be limited only to the abovementioned instruments. the inclusion of instruments such as force plate or pressure sensor [93-94], as fatigue is also associated with vestibular disturbance [39], or actiwatch to measure daily activity levels [90], may be necessary. with monism principle is being taken into account, we can argue that physical fatigue may induce mental fatigue and vice versa. the combination of the physical and mental condition is probably the reason of great inter-subject variability commonly observed in fatigue study. thus, to understand the inter-correlation between various aspects of fatigue is probably the greatest challenge in driving fatigue study. this is figure 11. summary of driving fatigue detection methodsand the type of fatigue detected by the relevant methods k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 44 especially important in combining the measurement methods and data analyses. iv. conclusion in this article, we describe the most common fatigue detection methods using physiological and biomechanical measurement instruments.the combination of various instruments and methods may result in more reliable measurements to uncover many aspects of driving fatigue, as one instrument limitations may be covered by other instruments. on the other hand, such approach requires a better understanding of human body characteristics other than good knowledge of the measurement instruments. thus, a multidisciplinary approach is a must for this kind of research. putting present and future problems of manmachine interaction studies into perspective, the interaction will always generate fatigue, however, the balance between physical and mental fatigue may vary. on the contrary to the traditional assumption of mind and body dualism, which see those two entities as separated each other, both physical and mental fatigue are imposed in one human body and both interact each other. despite some assumption that future transportation will likely be less dependent on the human driver and become more autonomous, the study on driver fatigue will still be crucial in transportation ergonomics either in the future. the first reason is that the transition from humandriver into an autonomous vehicle will take a longer time since the entire supporting system for such vehicle should be provided before its widespread operation. the second reason is that any activity will always produce fatigue, with changing proportion of physical and mental fatigue. the autonomous vehicle is probably physically less fatiguing, however, it will likely to induce greater mental fatigue with the more complex learning process and decision making. the third reason is that the measurement systems that involve digital signal will allow researchers to develop various ways of human interaction with the vehicle with regard to control and feedback, based on the signal processing. hence, this kind of study should be relevant in the foreseeable future along with vehicle technology development. references [1] b. z. khan, “knowledge, human capital, and economic development: evidence from the british industrial revolution, 1750-1930,” 2015. [2] g. w. jones, contemporary demographic transformations in china, india and indonesia. cham: springer international publishing, 2016. [3] “prioritas pembangunan nasional.” [online]. available: http://www.bappenas.go.id/files/8213/502 7/5942/bab-i-prioritas-pembangunannasional.pdf. [accessed: 25-feb-2016]. [4] world health organization, “global status report on road safety,” geneva, 2015. [5] k. t. chui et al., “electrocardiogram based classifier for driver drowsiness detection,” in proceeding 2015 ieee international conference on industrial informatics, indin 2015, 2015, pp. 600– 603. [6] “kecelakaan lalu lintas menjadi pembunuh terbesar ketiga | badan intelijen negara republik indonesia.” [online]. available: http://www.bin.go.id/awas/detil/197/4/21/ 03/2013/kecelakaan-lalu-lintaspembunuh-terbesar-ketiga. [accessed: 25feb-2016]. [7] l. l. di stasi et al., “effects of driving time on microsaccadic dynamics,” exp. brain res., vol. 233, no. 2, pp. 599–605, 2015. [8] m. rost et al., “comparing contribution of algorithm based physiological indicators for characterisation of driver drowsiness,” j. med. bioeng., vol. 4, no. 5, pp. 391–398, 2015. [9] x. fan et al., “electroencephalogram assessment of mental fatigue in visual search,” biomed. mater. eng., vol. 26, no. 37, pp. 1455–1463, 2015. [10] e. michail et al., “eeg and hrv markers of sleepiness and loss of control during car driving,” in engineering in medicine and biology society, 2008. embs 2008. 30th annual international conference of the ieee, 2008, pp. 2566–2569. [11] w. sun et al., “blink number forecasting based on improved bayesian fusion algorithm for fatigue driving detection,” math. probl. eng., pp. 1–13, 2015. [12] j. vicente et al., “drowsiness detection using heart rate variability,” med. biol. eng. comput., 2016. [13] k. lienhard et al., “semg during wholebody vibration contains motion artifacts and reflex activity,” j. sport. sci. med., vol. 14, no. 1, pp. 54–61, 2014. [14] j. h. ju et al., “real-time driver ’ s k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 45 biological signal monitoring system,” sensors mater., vol. 27, no. 1, pp. 51–59, 2015. [15] t. selvan n and r. shanmugalakshmi, “a review on driver fatigue detection system,” int. j. innov. sci. appl. eng. res., vol. 13, no. 4, pp. 29–33, 2015. [16] e. rashedi and m. a. nussbaum, “a review of occupationally-relevant models of localised muscle fatigue,” int. j. hum. factors model. simul., vol. 5, no. 1, pp. 61–80, 2015. [17] c. d. marlin, “the physiology of fatigue in horses during exercise,” time, 2007. [18] d.-h. kang et al., “effects of lowfrequency electrical stimulation on cumulative fatigue and muscle tone of the erector spinae.,” j. phys. ther. sci., vol. 27, no. 1, pp. 105–8, 2015. [19] n. r. carlson, physiology of behavior. new york: allyn&bacon, 2010. [20] s. b. n. thompson, “yawning, fatigue, and cortisol: expanding the thompson cortisol hypothesis,” med. hypotheses, vol. 83, no. 4, pp. 494–496, 2014. [21] p. n. lahange et al., “driver ’ s face monitoring system for det ecting hypovigilance : a review,” int. j. res., vol. 2, no. 4, pp. 553–559, 2015. [22] j. f. may and c. l. baldwin, “driver fatigue: the importance of identifying causal factors of fatigue when considering detection and countermeasure technologies,” transp. res. part f traffic psychol. behav., vol. 12, no. 3, pp. 218– 224, 2009. [23] l. j. trejo et al., “eeg-based estimation and classification of mental fatigue,” psychology, vol. 06, no. 05, pp. 572–589, 2015. [24] m. sato, “the development of conceptual framework in physiological anthropology,” j. physiol. anthropol. appl. human sci., vol. 24, no. 4, pp. 289– 295, 2005. [25] k. iwanaga, “the biological aspects of physiological anthropology with reference to its five keywords.,” j. physiol. anthropol. appl. human sci., vol. 24, pp. 231–235, 2005. [26] a. schmidt, “biosignals in humancomputer interaction,” interactions, vol. 23, no. 1, pp. 76–79, dec. 2015. [27] d. a. winter, biomechanics and motor control of human movement. john wiley & sons, 2009. [28] b. rosenhahn et al., “human motion understanding, modelling, capture, and animation,” image (rochester, n.y.), p. 635, 2008. [29] d. papaioannou et al., “literature searching for social science systematic reviews: consideration of a range of search techniques,” health info. libr. j., vol. 27, no. 2, pp. 114–122, 2010. [30] m. boeker et al., “literature search methodology for systematic reviews: conventional and natural language processing enabled methods are complementary (letter commenting on: j clin epidemiol. 2015;68:191-9),” j. clin. epidemiol., vol. 69, pp. 255–257, 2016. [31] a. skene, “writing a literature review,” toronto, 2012. [32] university of north carolina, “literature reviews.,” chapel hill, 2014. [33] t. a. dingus et al., “driver crash risk factors and prevalence evaluation using naturalistic driving data,” pp. 1–7, 2016. [34] h. j. oh et al., “effects of superimposition of a head-up display on driving performance and glance behavior in the elderly,” int. j. hum. comput. interact., vol. 32, no. 2, pp. 143– 154, oct. 2015. [35] f. naujoks et al., “secondary task engagement and vehicle automation – comparing the effects of different automation levels in an on-road experiment,” transp. res. part f traffic psychol. behav., vol. 38, pp. 67–82, apr. 2016. [36] k. m. gruevski et al., “lumbar postures, seat interface pressures and discomfort responses to a novel thoracic support for police officers during prolonged simulated driving exposures,” appl. ergon., vol. 52, pp. 160–168, 2016. [37] x. wu et al., “pilot’s visual attention allocation modeling under fatigue,” technol. heal. care, vol. 23, no. s2, pp. s373–s381, 2015. [38] a. g. richardson et al., “the effects of acute cortical somatosensory deafferentation on grip force control,” cortex, vol. 74, pp. 1–8, 2016. [39] g. y. menshikova et al., “eye movements as indicators of vestibular dysfunction,” perception, vol. 0, no. 0, pp. 1–7, 2015. [40] c. diels and j. e. bos, “self-driving carsickness,” appl. ergon., vol. 53, pp. 374–382, 2015. [41] c. ho and c. spence, “affective k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 46 multisensory driver interface design,” int. j. veh. noise vib., vol. 9, no. 1–2, pp. 61– 74, 2013. [42] a. lundkvist and a. nykänen, “response times for visual, auditory and vibrotactile directional cues in driver assistance systems,” sae int. j. transp. saf., vol. 4, no. 1, apr. 2016. [43] t. hamaguchi et al., “estimation of driver workload based on the model of accelerator pedal control while controlling vehicle speed,” sae tech. pap., no. 2016–01–1412, apr. 2016. [44] y. xiao et al., “sustained attention is associated with error processing impairment: evidence from mental fatigue study in four-choice reaction time task.,” plos one, vol. 10, no. 3, p. e0117837, 2015. [45] a. vakulin et al., “behavioural observation as a means of assessing sleepiness related driving impairment in obstructive sleep apnoea,” eat, sleep, work, vol. 1, 2015. [46] y. dong et al., “driver inattention monitoring system for intelligent vehicles: a review,” ieee trans. intell. transp. syst., vol. 12, no. 2, pp. 596–614, 2011. [47] k. lienhard and s. s. colson, “relationship between lower limb muscle activity and platform acceleration during whole-body vibration exercise,” no. october, 2015. [48] n. van der stoep et al., “multisensory interactions in the depth plane in front and rear space: a review,” neuropsychologia, vol. 70, no. december, pp. 335–349, 2015. [49] s. lee et al., “effects of active noise control on physiological functions,” j. human-environment syst., vol. 12, no. 2, pp. 49–54, 2009. [50] h. m. abd-elfattah et al., “physical and cognitive consequences of fatigue: a review,” j. adv. res., vol. 6, no. 3, pp. 351–358, 2015. [51] s. b. n. thompson and s. richer, “how yawning and cortisol regulates the attentional network,” j. neurosci. rehabil., vol. 2, no. 1, pp. 1–9, 2015. [52] c. ahlstrom et al., “fit-for-duty test for estimation of drivers’ sleepiness level: eye movements improve the sleep/wake predictor,” transp. res. part c emerg. technol., vol. 26, pp. 20–32, 2013. [53] m. gonzalez-izal et al., “electromyographic models to assess muscle fatigue,” j. electromyogr. kinesiol., vol. 22, no. 4, pp. 501–512, 2012. [54] d. marlin, “the physiology of fatigue in the horse during exercise: what is fatigue? what causes it? how can you recognise and manage fatigue?” [online]. available: http://davidmarlin.co.uk/portfolio/thephysiology-of-fatigue-in-the-horseduring-exercise/. [accessed: 17-mar2016]. [55] j. taylor et al., “neural contributions to muscle fatigue: from the brain to the muscle and back again,” j. med. sci. sport exerc., 2016. [56] c. froyd et al., “the development of peripheral fatigue and short-term recovery during self-paced high-intensity exercise,” j physiol, vol. 591, no. 5, pp. 1339–1346, 2013. [57] d. srinivasan et al., “effects of concurrent physical and cognitive demands on muscle activity and heart rate variability in a repetitive upper-extremity precision task,” eur. j. appl. physiol., vol. 116, no. 1, pp. 227–239, 2016. [58] c. chen et al., “visual fatigue caused by watching 3dtv : an fmri study,” biomed. eng. online, vol. 14, no. suppl 1, p. s12, 2015. [59] j. f. hopstaken et al., “a multifaceted investigation of the link between mental fatigue and task disengagement,” psychophysiology, vol. 52, no. 3, pp. 305– 315, 2015. [60] s. zhao, “study on driver model parameters distribution for fatigue driving levels based on quantum genetic algorithm,” open cybern. syst. j., vol. 9, pp. 1559–1566, 2015. [61] c. solomon and z. wang, “driver attention and behavior detection with kinect,” j. image graph., vol. 3, no. 2, pp. 84–89, 2015. [62] j. paone et al., “baseline face detection, head pose estimation, and coarse direction detection for facial data in the shrp2 naturalistic driving study,” in ieee intelligent vehicles symposium, proceedings, 2015, vol. 2015-augus, pp. 174–179. [63] c. k. zope and y. c. kulkarni, “driver drowsiness detection by driver aided system using smartphone,” int. j. it, eng. appl. sci. res., vol. 4, no. 6, pp. 4–7, 2015. k.h.sanjaya et al. /j. mechatron. electr. power veh. technol. 07 (2016) 35-48 47 [64] a. koenig et al., “statistical sensor fusion of ecg data using automotive-grade sensors,” adv. radio sci., vol. 13, pp. 197–202, 2015. [65] n. munk et al., “noninvasively measuring the hemodynamic effects of massage on skeletal muscle: a novel hybrid nearinfrared diffuse optical instrument,” j. bodyw. mov. ther., vol. 16, no. 1, pp. 22– 28, 2012. [66] h. qi et al., “non-contact driver cardiac physiological monitoring using video data,” in ieee china summit and international conference on nal and information processing, 2015, pp. 418– 422. [67] r. roy and k. venkatasubramanian, “ekg/ecg based driver alert system for long haul drive,” indian j. sci. technol., vol. 8, no. 19, pp. 8–13, 2015. [68] p. konrad, the abc of emg: a practical introduction to kinesiological electromyography, no. 1. scottsdale, az: noraxon, 2005. [69] c. j. de luca, “the use of surface electromyography in biomechanics,” j. appl. biomech., vol. 13, no. 2, pp. 135– 163, 1997. [70] g. e. loeb and c. gans, electromyography for experimentalists. university of chicago press, 1986. [71] l. a. c. kallenberg and h. j. hermens, “behaviour of a surface emg based measure for motor control: motor unit action potential rate in relation to force and muscle fatigue,” j. electromyogr. kinesiol., vol. 18, no. 5, pp. 780–788, 2008. [72] s. thongpanja et al., “mean and median frequency of emg signal to determine muscle force based on timedependent power spectrum,” elektron. ir elektrotechnika, vol. 19, no. 3, pp. 51–56, 2013. [73] d. moshou et al., “dynamic muscle fatigue detection using self-organizing maps,” appl. soft comput., vol. 5, no. 4, pp. 391–398, 2005. [74] a. f. t. ibrahim et al., “analysis of electromyography (emg) signal for human arm muscle: a review,” in advanced computer and communication engineering technology, cham: springer international publishing, 2016, pp. 567– 575. [75] m. chappell and s. payne, physiology for engineers, vol. 13. cham: springer international publishing, 2016. [76] d. a. dimitriev et al., “state anxiety and nonlinear dynamics of heart rate variability in students,” plos one, vol. 11, no. 1, p. e0146131, 2016. [77] a. davies and a. scott, “ecg basics,” in starting to read ecgs: the basics, cambridge, uk: springer international publishing, 2014, pp. 19–33. [78] a. d. elliott and a. la gerche, “the right ventricle following prolonged endurance exercise: are we overlooking the more important side of the heart? a metaanalysis.,” br. j. sports med., no. june 2016, pp. 1–6, 2014. [79] e. rogado et al., “driver fatigue detection system,” 2008 ieee int. conf. robot. biomimetics, robio 2008, no. july 2015, pp. 1105–1110, 2008. [80] f. chouchou et al., “cardiac sympathetic modulation in response to apneas/hypopneas through heart rate variability analysis.,” plos one, vol. 9, no. 1, p. e86434, 2014. [81] l. m. b. h. de rosario, j.s. solaz, n. rodrı́guez, “controlled inducement and measurement of drowsiness in a driving simulator,” in iet intelligent transport system, 2010, pp. 280–288. [82] g. matthews et al., “the psychometrics of mental workload: multiple measures are sensitive but divergent,” hum. factors j. hum. factors ergon. soc., vol. 57, no. 1, pp. 125–143, 2015. [83] donald scott, understanding eeg, first edit. glasgow: duckworth, 1976. [84] a. dasgupta et al., “a vision-based system for monitoring the loss of attention in automotive drivers,” ieee trans. intell. transp. syst., vol. 14, no. 4, pp. 1825– 1838, 2013. [85] a. t. bahill et al., “dynamic overshoot in saccadic eye movements is caused by neurological control signed reversals.,” exp. neurol., vol. 48, no. 1, pp. 107–122, 1975. [86] q. ji et al., “real-time nonintrusive monitoring and prediction of driver fatigue,” ieee trans. veh. technol., vol. 53, no. 4, pp. 1052–1068, 2004. [87] y. lin et al., “eye movement and pupil size constriction under discomfort glare,” invest. ophthalmol. vis. sci., vol. 56, no. 3, pp. 1649–1656, 2015. k.h.sanjaya et al. / j. mechatron. electr. power veh. technol. 07 (2016) 35-48 48 [88] k. sanjaya et al., “the effects of different trunk inclinations on bilateral trunk muscular activities, centre of pressure and force exertions in static pushing postures,” j. hum. ergol. (tokyo)., vol. 43, pp. 9–26, 2014. [89] k. h. sanjaya et al., “the influence of laterality on different patterns of asymmetrical foot,” j. hum. ergol. (tokyo)., vol. 43, pp. 77–92, 2014. [90] j. townhill et al., “using actiwatch to monitor circadian rhythm disturbance in huntington’ disease: a cautionary note,” j. neurosci. methods, pp. 1–6, 2016. [91] “ecg: cardiology | heart sounds | research | biopac.” [online]. available: https://www.biopac.com/application/ecgcardiology/advanced-feature/heartsounds/. [accessed: 24-may-2016]. [92] m. g. khan, “step-by-step method for accurate electrocardiogram interpretation,” in contemporary cardiology: rapid ecg interpretation, 3rd ed., 2008, pp. 25–80. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. accreditation by lipi: acc number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. accreditation by indonesian ministry of rthe: acc number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.php/ mev/login need a username/password? go to registration at: http://mevjournal.com/index.php/ mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nc-licensed work does not necessarily mean you have violated the term. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. indexing & abstracting mev has been covered by these following indexing services: ebscohost, directory of open access journal (doaj), google scholar, crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. at this moment, mev journal is currently under scopus review. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. arjon turnip technical management unit for instrumentation development lipi komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia deputy editors aam muharam, m.t. dept. of applied science for electronics and materials. kyushu university 6-1 kasuga-koen, kasuga-city, fukuoka – japan tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia managing editors, central office ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia mechanical engineering merry i devi, s.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia industrial engineering hendri m saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia robotics and mechatronics managing editor, asia pacific region yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, republic of managing editor, europe region naili huda, m.eng.sc. warwick university coventry cv4 7al, united kingdom editors aditya sukma nugraha, m.t. mechanical engineering agus risdiyanto, m.t. electrical engineering amin, m.t. electrical engineering arief a firdaus, s.i.kom. communication science arini wresta, m.eng. chemical engineering bambang wahono, m.eng. mechanical engineering dian andriani, m.eng. bioenergy engineering dr. edwar yazid dynamics and control system kadek heri sanjaya, ph.d ergonomics, biomechanics, physiology maulana arifin, m.t. mechanical engineering midriem mirdanies, m.t. computer engineering muhammad kasim, m.renen electrical engineering nur rohmah, m.t. chemical engineering rakhmad indra pramana, m.t. mechanical and material engineering rifa rahmayanti, m.sc mechatronics and robotics sapdo utomo, m.t. mechatronics and robotics vita susanti, s.kom computer science yayat ruhiyat, a.md. electrical engineering web admin dadan r saleh, m.t. informatics engineering secretariat andri j purwanto, s.t. mechanical engineering graphic designer yukhi mustaqim kusuma sya bana, s.sn. graphic design journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 © 2016 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (jmev) is an international journal indexed by google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib, cite factor, and others. its digital object identifier (doi) prefix is 10.14203. in this issue, six papers are published with the total number of paper pages of 56 pages. two papers are written by a principal author from japan dan south korea. other authors come from indonesia, egypt, and lybia. one paper is related to mechatronics which describes aiming direction accuracy analysis of geometrical and numerical inverse kinematic approaches for two degrees of freedom robot manipulator. the manipulator degrees of freedom are azimuth and elevation angles. the analysis was carried out based on experiment results using circular error probable (cep) and other statistical parameters. three papers address topics on electrical power. the first paper deals with a problem of designing load frequency control (lfc) in a multi area power system. it proposes a new design method through a selection of optimal lqr parameter values using artificial immune system (ais) algorithm. the second paper describes a method to determine optimum sizing and placement of shunt capacitor in order to reduce line losses. the ieee-14 bus test system is used for the case study. derivative load bus voltage is simulated to determine the most sensitive load bus, while particle swarm optimization (pso) algorithm is carried out to determine the optimum size of shunt capacitor at the most sensitive bus. the third paper presents the design, implementation, and economic evaluation of a hybrid pv-battery/diesel electricity supply in pulau peucang, an isolated small island at the west of java island indonesia. two different battery options were taken into account, lead-acid batteries and lithium-ion batteries. levelized cost of energy (lcoe) of the system is explained. the results may also give a rough orientation for other locations which have similar characteristics. in the scope of vehicular technology, there are two papers presented. the first paper builds a prototype of small-scale electric vehicle simulator (evs) and a simple charging scheme of the supercapacitor. a supercapacitor is one of electrical energy sources that have faster charging-discharging times when compared to other power sources, such as battery and fuel cell. the supercapacitor charging scheme is employed by controlling the relays. this scheme is simple, and it is useful for education purpose. the second paper reports results of performance comparison between diesel engine based range extender and gasoline engine based range extender. fuel consumption and co2 emission are investigated through simulation. single cylinder 499 cc gasoline engine and single cylinder 667 cc diesel engine are chosen. the simulation is performed using japan 08 driving cycle. since the first volume, our journal provides discretion in the financial term by waiving the article processing charge. we are planning to improve the quality by registering the journal to other international academic citation index. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwavering support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers, and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2016 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 ii list of contents derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses mohamed milad baiek, ahmad e. esmaio, muhammad nizam, miftahul anwar, hasan m.s. atia 67-76 simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose adnan rafi al tahtawi, arief syaichu rohman 77-86 fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine bambang wahono, arifin nur, achmad praptijanto, widodo budi santoso, suherman, zong lu 87-92 optimal selection of lqr parameter using ais for lfc in a multi-area power system muhammad abdillah, herlambang setiadi, adelhard beni reihara, karar mahmoud, imam wahyudi farid, adi soeprijanto 93-104 accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator hendri maja saputra, midriem mirdanies, estiko rijanto 105-112 a hybrid pv-battery/diesel electricity supply on peucang island: an economic evaluation matthias günther 113-122 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 07, issue 2, december 2016 abstracts sheet e-issn: 2088-6985 date of issues: 23 december 2016 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. mohamed milad baieka, ahmad e. esmaioa, muhammad nizama, miftahul anwara, hasan m.s. atiab (apostgraduate program, mechanical engineering department, sebelas maret university, jl. ir. sutami no. 36-a surakarta, indonesia; bgeneral electricity company of libya (gecol), gecol building, jamahiriya area 668 tarabulus, tripoli, libya) derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses journal of mechatronics, electrical power, and vehicular technology, december 2016, vol. 7, no. 2, p. 67-76, 11 ill, 7 tab, 13 ref. the purpose of this research is to study optimal size and placement of shunt capacitor in order to minimize line loss. derivative load bus voltage was calculated to determine the sensitive load buses which further being optimum with the placement of shunt capacitor. particle swarm optimization (pso) was demonstrated on the ieee 14 bus power system to find optimum size of shunt capacitor in reducing line loss. the objective function was applied to determine the proper placement of capacitor and get satisfied solutions towards constraints. the simulation was run over matlab under two scenarios namely base case and increasing 100% load. derivative load bus voltage was simulated to determine the most sensitive load bus. pso was carried out to determine the optimum sizing of shunt capacitor at the most sensitive bus. the results have been determined that the most sensitive bus was bus number 14 for the base case and increasing 100% load. the optimum sizing was 8.17 mvar for the base case and 23.98 mvar for increasing load about 100%. line losses were able to reduce approximately 0.98% for the base case and increasing 100% load reduced about 3.16%. the proposed method was also proven as a better result compared with harmony search algorithm (hsa) method. hsa method recorded loss reduction ratio about 0.44% for the base case and 2.67% when the load was increased by 100% while pso calculated loss reduction ratio about 1.12% and 4.02% for the base case and increasing 100% load respectively. the result of this study will support the previous study and it is concluded that pso was successfully able to solve some engineering problems as well as to find a solution in determining shunt capacitor sizing on the power system simply and accurately compared with other evolutionary optimization methods. (author) keywords: particle swarm optimization; shunt capacitor; line losses. adnan rafi al tahtawia, arief syaichu rohmanb (adepartment of computer engineering, politeknik sukabumi, jl. babakan sirna no. 25, sukabumi, indonesia; blaboratory for control and computer systems, institut teknologi bandung, jl. ganesha no. 10, bandung, indonesia) simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose journal of mechatronics, electrical power, and vehicular technology, december 2016, vol.7, no. 2, p. 77-86, 11 ill, 2 tab, 18 ref. supercapacitor is one of electrical energy sources that have faster charging-discharging times when compared to other power sources, such as battery and fuel cell. therefore, it is often used as an additional power source in an electric vehicle. in this paper, a prototype of small-scale electric vehicle simulator (evs) is built and a simple charging scheme of supercapacitor is used for education purpose. evs is an electric vehicle prototype which can show the vehicle’s powertrain on small-scale configuration. main components of this device are two direct current motors (dcms) with a linked axis of rotation. therefore one of them will be able to act as a generator. the supercapacitor charging scheme is employed by controlling the relays. the hardware experimental result shows that the averages of charging current are proportional to the maximum slope angle of the road profiles. this scheme is simple due to the evs utility and it is useful for education purpose. (author) keywords: supercapacitor; charging; electric vehicle simulator (evs); direct current motor (dcm). bambang wahonoa, b *, arifin nurb , achmad praptijantob , widodo budi santosob , suhermanb , zong luc (agraduate school of mechanical engineering, university of ulsan, san 29, mugeo2dong, nam-gu, ulsan 44610, republic of korea; bresearch centre for electrical power and mechatronics, indonesian institute of sciences (lipi), komplek lipi, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia; cbrother industries, ltd. 15-1 naeshirocho, mizuho-ku, nagoya, 467-8561, japan) fuel consumption and co2 emission investigation of range extender with diesel and gasoline engine journal of mechatronics, electrical power, and vehicular technology, december 2016, vol. 7, no. 2, p. 87-92, 7 ill, 5 tab, 17 ref. range extender engine is one of the main components of the rangeextended electric vehicle (reev) and together with a generator to extend the mileage of the electric vehicle. the main component of reev is an electric motor, battery, and generator set that consist of generator and engine. in this study, we compared two models of reev performance with two different types of the engine by simulation. single cylinder 499 cc gasoline engine and single cylinder 667 cc diesel engine are chosen as the object of this journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv research especially relating to the utilization of the fuel consumption and co2 emissions when fitted to an electric vehicle. the simulation was conducted by using avl cruise software and performed by entering the data, both experiment and simulation data, on all the main components of reev. this simulation was performed in japan 08 driving cycle. based on the simulation, fuel consumption is reduced up to 35.59% for reev with single cylinder diesel engine 667 cc compared to reev with single cylinder gasoline engine 499 cc. the reduction of co2 emissions from reev with single cylinder 499 cc gasoline engine compared to reev with single cylinder 667 cc diesel engine up to 30.47%. (author) keywords: range extender engine; performance; diesel; gasoline; avl cruise. muhammad abdillaha, herlambang setiadib, adelhard beni reiharaa,c, karar mahmoudd, imam wahyudi farida, adi soeprijantoe (adepartment of cybernetics, graduate school of engineering, hiroshima university 4-1, kagamiyama 1chome, higashi-hiroshima, 739-8527, japan; bdepartment of electrical engineering, university of bhayangkara, jl. ahmad yani 114, surabaya, jawa timur 60231, indonesia; cdepartment of electrical engineering, university of papua, jln. gunung salju, amban, manokwari, indonesia; dfaculty of engineering, aswan university, sahari city-airport way, aswan, 81528, egypt; edepartment of electrical engineering, institut teknologi sepuluh nopember, building b, c & aj campus its sukolilo surabaya, east java, 60111, indonesia) optimal selection of lqr parameter using ais for lfc in a multiarea power system journal of mechatronics, electrical power, and vehicular technology, december 2016, vol. 7, no. 2, p. 93-104, 12 ill, 7 tab, 17 ref this paper proposes a method to optimize the parameter of the linear quadratic regulator (lqr) using artificial immune system (ais) via clonal selection. the parameters of lqr utilized in this paper are the weighting matrices q and r. the optimal lqr control for load frequency control (lfc) is installed on each area as a decentralized control scheme. the aim of this control design is to improve the dynamic performance of lfc automatically when unexpected load change occurred on power system network. the change of load demands 0.01 p.u used as a disturbance is applied to lfc in area 1. the proposed method guarantees the stability of the overall closed-loop system. the simulation result shows that the proposed method can reduce the overshoot of the system and compress the time response to steady-state which is better compared to trial error method (tem) and without optimal lqr control. (author) keywords: linear quadratic regulator (lqr); artificial immune system; clonal selection; load frequency control (lfc). hendri maja saputra, midriem mirdanies, estiko rijanto (research center for electrical power and mechatronics, indonesian institute of sciences, komplek lipi, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia) accuracy analysis of geometrical and numerical approaches for two degrees of freedom robot manipulator journal of mechatronics, electrical power, and vehicular technology, december 2016, vol. 7, no. 2, p. 105-112, 10 ill, 3 tab, 15 ref. analysis of algorithms to determine the accuracy of aiming direction using two inverse kinematic approaches i.e. geometric and numeric has been done. the best method needs to be specified to precisely and accurately control the aiming direction of a two degrees of freedom (tdof) manipulator. the manipulator degrees of freedom are azimuth (az) and elevation (el) angles. a program has been made using c language to implement the algorithm. analysis of the two algorithms was done using statistical approach and circular error probable (cep). the research proves that accuracy percentage of numerical method is better than geometrical method, those are 98.63% and 98.55%, respectively. based on the experiment results, the numerical approach is the right algorithm to be applied in the tdof robot manipulator. (author) keywords: azimuth; elevation; geometrical; numerical; c language. matthias günther (research center for renewable energy and energy efficiency, swiss german university, edutown, bsd, 15339 tangerang, indonesia) a hybrid pv-battery/diesel electricity supply on peucang island: an economic evaluation journal of mechatronics, electrical power, and vehicular technology, december 2016, vol. 7, no. 2, p. 113-122, 9 ill, 3 tab, 18 ref. renewable energy technologies are currently under a dynamic cost development. this case holds especially for solar technology that has reached price levels that were unimaginable until a short time ago. it also holds for battery technologies the application of which is related to the increasing usage of photovoltaic energy converters and the growing interest in electric vehicles. with the decreasing prices more and more possible application cases of renewable energy technologies become economically viable. a case study was done for a location on a small island located on the west tip of java. the levelized electricity cost of a hybrid electricity supply system composed of a solar generator and battery in combination with the existing diesel generators was compared to the electricity generation cost of the existing system. two different battery options were taken into account, lead-acid batteries and lithium-ion batteries. the results of this study can give a rough orientation also for other locations with similar characteristics. (author) keywords: hybrid electricity supply; photovoltaics; lead-acid battery; lithium-ion battery; peucang island. mev j. mechatron. electr. power veh. technol 07 (2016) 21-26 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.21-26. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. application of empirical mode decomposition method for characterization of random vibration signals setyamartana parman a, edwar yazid b,* amechanical engineering departement, universiti teknologi petronas bandar seri iskandar, 31750 tronoh, perak, malaysia bresearch center for electrical power and mechatronics, indonesian institute of sciences jl. sangkuriang komplek lipi gedung 20, 40135 bandung, indonesia received 13 march 2016; received in revised form 27 april 2016; accepted 28 april 2016 published online 29 july 2016 abstract characterization of finite measured signals is a great of importance in dynamical modeling and system identification. this paper addresses an approach for characterization of measured random vibration signals where the approach rests on a method called empirical mode decomposition (emd). the applicability of proposed approach is tested in one numerical and experimental data from a structural system, namely spar platform. the results are three main signal components, comprising: noise embedded in the measured signal as the first component, first intrinsic mode function (imf) called as the wave frequency response (wfr) as the second component and second imf called as the low frequency response (lfr) as the third component while the residue is the trend. band-pass filter (bpf) method is taken as benchmark for the results obtained from emd method. keywords: emd; bpf; imf; vibration signals. i. introduction modeling and system identification either based on input-output or output-only models require finite measured signals. characterization of signals is a great of importance in selecting identification models. in practice, there are three main components in raw signals; namely noise, dynamical characteristics of the system and trend. noise with certain level of snr distributes in gaussian and non-gaussian functions. if the noise has gaussian function, zero-mean with finite variance and statistically uncorrelated variables, then it is called as gaussian white noise. this type of noise is embedded in mostly random vibration signals in addition to nongaussian and non-white noise. noise with high level of snr has significant effect in time and frequency domains. in time domain, noise tends to lower the modeling accuracy. further, in frequency domain, noise tends to hide the predominant frequency bands. dynamical characteristics of the system cover the linear and non-linear behaviors. the latter appears in signals in terms of sub harmonics, super harmonics and frequency interactions [1-2]. if the behaviors change with respect to time, then the system is linear and non-linear time-varying systems. identification models must accommodate the non-stationary of the system in terms of timevarying model coefficients. recent researches in this area can be found in [3-4]. trend is characterized as a long-term movement in signals. it has an upward or downward tendency and rate of change in a time series. in many cases, this trend leads to a direct component (dc) term in signals. these three main components must be characterized as a preliminary stage for modeling and system identification of system dynamic. the results can be taken as consideration for choosing the suitable model structure and model coefficient estimation method for identification models. this paper proposes the application of empirical mode decomposition (emd) method in de noising, de trending, and decomposing the measured random vibration signals into the three main components. the method is applied in one numerical and experimental data. * corresponding author. tel: +6222-2503055 e-mail: edwar.putra@gmail.com http://dx.doi.org/10.14203/j.mev.2016.v7.21-26 s. parman and e. yazid / j. mechatron. electr. power veh. technol 07 (2016) 21-26 22 ii. empirical mode decomposition the essence of empirical mode decomposition is to decompose signal into its oscillatory mode, called intrinsic mode function (imf). this is achieved by sifting process. the overall emd algorithm has been well documented in reference [5-8]. details are available in those references, but it is revisited in this paper for a more concise notation. a step by step procedure of emd method can be summarized as follows: 1. identify all the local extreme, maxima and minima of, and then connect the local maxima and minima using the cubic spline to obtain the upper and lower envelope, respectively. those envelopes should cover all the data of. their mean is designated as, and the difference between 𝒚(𝒏) and 𝒎𝟏 is defined by: 𝐻1(𝑡) = 𝑦(𝑛) − 𝑚1 (1) ideally, 𝒉𝟏 should be an imf if it satisfies two conditions: i) in all data of 𝒚(𝒏), the number of extrema and zero crossings must be either be equal or differ at most by one; and ii) at any point, the mean value of the envelope defined by the local maxima and minima is zero. 2. if 𝒉𝟏 does not satisfy the conditions, set 𝒉𝟏 as the original data and repeat the process in step 1 until the conditions are fulfilled and the first imf is achieved. 3. residue is then subtracted from step 2, taken as original signal and sifting process is repeated to obtain another imf. the process is repeated until 𝒎 imf is obtained, where relationship between imfs and the original data 𝒚(𝒏) may be expressed as: 𝑦(𝑛) = ∑ 𝐶1 (𝑛) + 𝑟𝑚 (𝑛) 𝑚 𝑖=1 (2) term 𝐶𝑖(𝑛) contains the imfs of the 𝑦(𝑛) , from high to low frequency components. each 𝐶𝑖(𝑛) also contains a different frequency component, while 𝑟𝑚(𝑛) is the residual which is the trend of the data or a constant. for an easy interpretation, all steps are depicted in figure 1. the square dot (…) denotes the upper envelope while the dash line (---) denotes the lower envelope and the mean envelope is denoted with long dash dot line (-.-.). since the residue (lower panel of figure 1) is not a monotonic function, sifting process is then performed following step 1 until step 3. in practice, sifting process produces an imf which contains more than one natural frequency component. this is called as a mode mixing, because of some drawbacks in the emd algorithm. the mode mixing must be avoided for the purpose of this paper. rilling et al. [9] proposed intermittent frequency to avoid the mode mixing. in their work, the intermittency is based on the period length to separate the signals into different modes. the criterion frequency is set as the upper limit of the period that can be included in any given imf component, so that the resulting imf will not contain any natural frequency components smaller than the intermittent frequency. however, the intermittent frequency as an additional criterion might not always guarantee the final expected results, since choosing the intermittent frequency is a subjective task. rato et al. [10] solved this problem by proposing some modifications on the emd algorithm. their finding results show that some issues related to the drawbacks of emd algorithm can be solved, such as mode mixing and tail effect. hence, their emd algorithm is adopted in this paper for decomposing the vibration signals. iii. numerical data to validate the application of emd method in filtering, detrending, and decomposing vibration signals, a deterministic discrete vibration signal is simply selected and described by eq. (3), 𝑦(𝑛) = 𝐴1 sin(2𝜋𝑓1𝑛) + 𝐴2 sin (2𝜋𝑓2𝑛), (3) where 𝐴 and 𝑓 are amplitude and frequency, respectively. the chosen system parameters for eq. (3) are as follows: 𝐴1 = 1, 𝐴2 = 2, 𝑓1 = 8 𝐻𝑧 and 𝑓2 = 4 𝐻𝑧, respectively. the signal is corrupted with a gaussian noise having snr of 40 db and a polynomial trend. the results are depicted in figure 2. it is seen in figure 2(a) that the noise can be accordingly extracted with snr of 41.05 db and has gaussian distribution. sinusoidal signal with respective frequency of 𝑓1 = 8𝐻𝑧 and 𝑓2 = 4𝐻𝑧 figure 1. process of emd method s. parman and e. yazid / j. mechatron. electr. power veh. technol 07 (2016) 21-26 23 can be also extracted with insignificant discrepancy between the actual result and that of emd method (figures 2(b) – 2(c)). similar result also can be observed for extracted polynomial trend as shown by figure 2(d). overall results in figure 2 show that the decomposition process results in signals from high frequency to low frequency. this finding result is also reported in the previous researches [7-8]. iv. experimental data the experimental scheme is shown in figure 3. details of setup have been described in [4] and briefly summarized here. the model test was tested in the wave tank, excited with excitation function (random waves) and measured with wave probes. the motion response in horizontal plane was measured by an optical tracking camera. a. raw data processing raw time series of motion response as a random vibration signal is displayed in figure 4(a). by observing the motion response in figure 4(a), it can be seen that the amplitudes distribution appears to be drifted upward. its probability density is unsymmetrical distributed, suggesting that the motion response is non-linear random waves and non-gaussian-type. this result is validated by using normality test under kolmogorov-smirnov test, lillie test, and jarquebera test. the motion response is also non stationary which is confirmed by kwiatkowskiphillips-schmidt-shin test, phillips-perron test, (a) (b) (c) (d) figure 2. emd results for numerical data (a) noise; (b) 𝑓1 = 8 𝐻𝑧; (c) 𝑓2 = 4 𝐻𝑧; (d) trend figure 3. experimental scheme s. parman and e. yazid / j. mechatron. electr. power veh. technol 07 (2016) 21-26 24 and augmented dickey-fuller test. as additional information, the motion response is non-white noise as validated with ljung-box q-statistic. the signal is then converted into frequency domain with fft length of 1024. it can be observed in figure 4(b) that the motion response has two principal frequency peaks. the first peak (low frequency response, lfr) is hidden around the low frequency. the second peak (wave frequency response, wfr) is clearly around 0.077 hz, corresponds to the frequency of random waves. it is seen that the first peak is hidden and is difficult to be identified although the fft length is higher than 1024 and only produces ripples. these results suggest that the signal of measured motion response is contaminated with noise and it might be due to a polynomial trend as proved by the next section. modeling and system identification using this data will lead to a biased estimation. hence, emd method is applied for characterization purpose so that noise and trend can be accordingly extracted from the signal. b. application of emd method based on result in figure 4(b), emd method is applied to the raw signal of motion response in the figure 4(a). this method simultaneously performs denoising, decomposition, and detrending in time domain. results in time domain are then converted into frequency domain using fft and depicted in figures 5-8. the first, second and third components are successfully decomposed by using fft length of 1024 for all components. as benchmark for the emd method, band-pass filter (bpf) method is chosen. as seen in those figures, decomposition results can be classified into noise, two imfs and a trend. each can be interpreted as follows: i) the first component is identified as measurement noise embedded in the raw signal of motion responses confirmed by fft result. ii) the first component is the first imf, identified as wfr as confirmed by fft result. the frequency is similar with the second peak in the lower panel of figure 4. iii) the second component is the second imf, identified as lfr as confirmed by fft result. the frequency is around 0.005 hz and looks clearer than the first peak in the lower panel of figure 4. iv) the last component is the trend of the motion response, which is found as a polynomial trend. the polynomial trend obtained from (a) (b) figure 4. raw data of motion response (a) time series; (b) spectrum (a) (b) figure 5. decomposition result: noise (a) time series; (b) spectrum s. parman and e. yazid / j. mechatron. electr. power veh. technol 07 (2016) 21-26 25 both methods has similar pattern where both trends increase with respect to time. when bpf method is applied as filter for the measured signal, the noise embedded in the signal is comparable with the first component, followed by the first and second imfs. minor differences are found between those two methods due to different resolution bandwidth. this finding result confirms that the emd method may be used as an alternative filter and decomposition tool for noisy signals besides the conventional bpf method. scale separation of emd method is adjusted to decompose the signal into the wfr and lfr according to the results shown in figure 4(b). with some trials, it is found that the best resolution for the separation scale is found to be around 7 10 db. for bpf method, after several trials, it is found out that the suitable band pass is between 0.04 hz and 0.1 hz for the wfr and between 0.001 hz and 0.03 hz for the lfr. based on results in figures 5-8, statistics of the signal are performed and listed in table 1. overall, it is shown that the mean, variance skewness and kurtosis values decrease after signal are treated with emd method. table 2 shows the properties of signal before and after emd method is applied. it can be seen that properties of signal are still preserved in this (a) (b) figure 6. decomposition result: the lfr (a) time series; (b) spectrum (a) (b) figure 7. decomposition result: the wfr (a) time series; (b) spectrum figure 8. decomposition result: trend table 1. basic statistics of experimental data data mean variance skewness kurtosis motion response *0.054 **0.728 *1.31 **1.33 *0.256 **0.335 *2.89 **3.16 *denoised, decomposed and detrended, **raw table 2. properties of experimental data data property motion response *non gaussian *non-stationary *nonwhite noise **non gaussian **non-stationary **nonwhite noise *denoised, decomposed and detrended, **raw s. parman and e. yazid / j. mechatron. electr. power veh. technol 07 (2016) 21-26 26 case, only its statistics change. it is noted that all the statistical tests are run under matlab statistics toolbox. v. conclusion emd method is able to decompose random vibration signals in terms of noise, imfs, and trend. bpf method as benchmark produces comparable results with minor differences due to different resolution bandwidth. selection of pass band range for decomposition process indicates that the emd method is more flexible than the bpf method. the noise and the trend can be included or excluded according to the purpose of identification process. as such, identification models in terms of model structure and model coefficient estimation method can be accordingly selected. as a recommendation, current work can be extended to the experimental modal analysis by combining the emd method with respective modal analysis method. acknowledgement the authors are thankful to cheng yee ng from universiti teknologi petronas for providing the experimental data. references [1] f. he et al., “spectral analysis for nonstationary and nonlinear systems: a discrete time model based approach,“ biomedical engineering, vol. 60(8), pp. 2233-2241, 2013. [2] e. yazid et al., ”identification of slow drift motions of a truss spar platform using parametric volterra model,“ journal of ocean engineering, vol. 109, pp. 654-668, 2015. [3] e. yazid et al., “improving the modeling capacity of volterra model using evolutionary computing methods based on kalman smoother adaptive filter,” journal of applied soft computing, vol. 35, pp. 695707, 2015. [4] e. yazid et al., “identification of transfer functions from surge motion response of a semisubmersible platform using timevarying narx model,“ journal of applied ocean research, vol. 54, pp. 53-66, 2016. [5] c. guo et al., “application of empirical mode decomposition to a jeffcott rotor with a breathing crack,“ journal of sound and vibration, vol. 332(16), pp. 3881-3892, 2013. [6] s.i. mc. neill, “decomposing a signal into short-time narrow-banded modes,“ journal of sound and vibration, vol. 373, pp. 325339, 2016. [7] l.lu et al., “dominant feature selection for the fault diagnosis of rotary machines using modified genetic algorithm and empirical mode decomposition,“ journal of sound and vibration, vol. 344, pp. 464-483, 2015. [8] f.jiang et al., “fault identification of rotor bearing system based on ensemble empirical mode decomposition and self-zero space projection analysis,“ journal of sound and vibration,vol.333(14), pp. 3321-3331, 2014. [9] g. rilling et al., “on empirical mode decomposition and its algorithms,” in proc. ieee-eurasip workshop on nonlinear signal and image processing, 2003. [10] r.t. rato et al., “on the hht, its problems, and some solutions,” mechanical systems and signal processing, pp. 1374-1394, vol. 22(6), 2008. i. introduction ii. empirical mode decomposition iii. numerical data iv. experimental data raw data processing application of emd method v. conclusion acknowledgement references mev j. mechatron. electr. power veh. technol 07 (2016) 77-86 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.77-86. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose adnan rafi al tahtawi a,*, arief syaichu rohman b a department of computer engineering, politeknik sukabumi jl. babakan sirna no. 25, sukabumi, indonesia b laboratory for control and computer systems, institut teknologi bandung jl. ganesha no. 10, bandung, indonesia received 14 september 2016; received in revised form 20 october 2016; accepted 23 october 2016 published online 23 december 2016 abstract supercapacitor is one of electrical energy sources that have faster charging-discharging times when compared to other power sources, such as battery and fuel cell. therefore, it is often used as an additional power source in an electric vehicle. in this paper, a prototype of small-scale electric vehicle simulator (evs) is built and a simple charging scheme of supercapacitor is used for education purpose. evs is an electric vehicle prototype which can show the vehicle’s powertrain on small-scale configuration. main components of this device are two direct current motors (dcms) with a linked axis of rotation. therefore one of them will be able to act as a generator. the supercapacitor charging scheme is employed by controlling the relays. the hardware experimental result shows that the averages of charging current are proportional to the maximum slope angle of the road profiles. this scheme is simple due to the evs utility and it is useful for education purpose. keywords: supercapacitor; charging; electric vehicle simulator (evs); direct current motor (dcm). i. introduction nowadays, electric vehicle researches are still being conducted. one of the research problems is the use of the battery as an electrical energy source for this vehicle. the limitation of battery lifetime impacts the vehicle’s traveling time. therefore, the specific technique is required to extend its lifetime. one of the solutions to overcome this problem is utilizing the additional power sources. supercapacitor is one of electrical energy sources that have a higher capacity of storing energy compared to a normal capacitor. this component also has faster chargingdischarging times when compared with other power sources. supercapacitor was worked as an electrical source with the highest frequency, while the battery was power source with a frequency between the fuel cell and supercapacitor [1]. it means that the chargingdischarging times of supercapacitor are faster than the others. due to this advantage, supercapacitors are often used as an additional power source in an electric vehicle. on the other hand, the electric motor as the main drive in electric vehicles may be utilized as a source of electrical energy through the regenerative braking. this process is used for electric energy charging. however, the problem is that the charging of the batteries takes a long time while the regenerative braking may take place in a relatively short time. by having a faster charging-discharging time, it is capable of storing electric energy faster, and the received electric energy during regenerative braking can be maximized. therefore, it was needed the specified strategy and technique to overcome this problem. several solutions have been investigated and discussed. a battery-supercapacitor energy management and optimization for electric vehicles have been discussed by choi et al. [2] and s. pay et al. [3]. modeling, evaluation, and simulation of the applications of supercapacitors * corresponding author.tel: +6281809214709 e-mail: adnanrafi@polteksmi.ac.id http://dx.doi.org/10.14203/j.mev.2016.v7.77-86 a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 78 in power electronics have been investigated by zhang et al. [4] and cultura et al. [5]. the charging and discharging methods of this device have also been presented chan et al. [6] and ban et al. [7]. as an addition, the various balancing circuits were used to overcome the imbalance of supercapacitor’s voltage in series, as discussed by diab et al. [8] and qu et al. [9]. in this paper, we will design the supercapacitor charging scheme and implement it on an electric vehicle simulator (evs). a laboratory at university of pennsylvania, mlab, has developed an evs in small scale by using a direct current motor (dcm) as the main component, known as protodrive. protodrive board was modular and rapid prototyping friendly, and the power flow indicator lights make it intuitive to understand how energy was transferred through the system (electric vehicle) [10]. in its demonstration, a velocity profile, altitude data, vehicle parameters and weather data were used as inputs to generate a scaled torque and speed profile which will be run on the protodrive hardware [11]. s. diaz [12], has designed various road profiles to show the voltages required by the dcms on the protodrive. battery-supercapacitor energy management on protodrive has been investigated by w. price [13] with the result was consumption of battery power could be reduced by 23.23%. lastly, the control algorithm has been described to run protodrive by mulay et al. [14]. this paper presents a simple charging scheme of a supercapacitor in an electric vehicle. the simple supercapacitor charging scheme is designed and implemented on an evs which refers to protodrive. the road profiles are designed at three types of road profile scenarios, i.e. one hill, two hills and trapezoidal. in this paper, the simple supercapacitor charging schemes will also be elaborated more detail and comprehensive. ii. electric vehicle simulator the evs is built to simulate the power train in electric vehicles on a small scale configuration. by using this device, electric vehicle’s power train will be more easily observed with obtained various scenarios. the preliminary simulator has been built by mlab university of pennsylvania known as protodrive. in this paper, an evs is built referring to protodrive by using component and configuration which are slightly different, as presented by al tahtawi et al. [15]. the main components of the simulator are two dcms which are directly connected each other by their axis of rotation. the torque generated by dcm1 is assumed as the torque needed by vehicle’s wheels, while the other is assumed as the torques due to forces from surroundings which interacted with the vehicle. the evs configuration consists of five main components, i.e. two units of dcm, battery, supercapacitor module, and microcontroller. current sensors, speed sensor, voltage sensors, dc/dc converters, l298n h-bridge modules, power supply, and spdt relays are also used as supporting components. unlike protodrive, this simulator uses separated dc/dc converters and h-bridge with spdt relays, while protodrive uses dcm controller with regenerative braking compatibility and equipped by dc/dc converter. besides that, microcontroller that used in this evs is atmega 2560 on arduino mega 2560 board (protodrive uses mbed microcontroller board by arm). lastly, this evs using dc power supply for dcm2 (not using the battery as protodrive). block diagram of evs which was modified from protodrive is depicted in figure 1. to simulate an actual electric vehicle, a particular algorithm is needed. in this paper, the designed algorithm is aimed to calculate the voltages needed for the two mechanically connected dcms as presented by a. botelho and w. price [10], s. diaz [12], and w. price [13]. the algorithm for each dcm is called first and second algorithms respectively. where as in research doing by a. mulay et al. [14], the algorithms were aimed at obtaining the voltage of dcm1 and the current of dcm2 for closed loop torque controls. the block diagram of the first algorithm that used in this paper is shown in figure 2. the first algorithm needs two inputs, i.e. speed profile and road profile, and it has output voltages for two dcms. the chosen speed profile is a constant speed of 10 m/s or 36 km/h, while the chosen road profiles consisted of three types, i.e. one hill, two hills, and trapezoidal profiles. the data collected from the aforementioned three road profiles is a slope angle of the road for every pre-determined distance. as a comparison, the second algorithm has two references, which are speed and torque. this algorithm is also using control system, such as pid controller, to reach the given references. thus, the first algorithm used in this study for simplicity due to education purpose. the first step for running this evs is designing the speed and road profiles. designs of both profiles are done by using matlab/m-file. speed profile is designed using the constant function. hills road profiles are designed using sinusoidal functions, while trapezoidal road profile is designed using partial linear equation. slope angle of road profile obtained by utilizing a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 79 the gradient method. road condition is also limited to uphill and downhill with no turn conditions. referring to protodrive, the voltages needed by the two dcms, as mentioned in the first algorithm, may be calculated as the following derivation. 𝐹𝑡 = 𝐹𝑎 + 𝐹𝑔 + 𝐹𝑑 + 𝐹𝑟 (1) where 𝐹𝑡, 𝐹𝑎, 𝐹𝑔, 𝐹𝑑, and 𝐹𝑟 respectively are forces of total traction at the wheels, acceleration, gravity, aerodynamic drag and rolling resistance of the tires. based on ehsani et al. [16], those forces are derived from these following equations: 𝐹𝑎 = 𝑚𝑎 (2) 𝐹𝑔 = 𝑚𝑣𝑔𝑠𝑖𝑛(𝜃) (3) 𝐹𝑑 = 1 2 𝑠𝑖𝑔𝑛(𝑣 + 𝑣𝑤 2)𝜌𝑎𝐴𝑓𝐶𝑑(𝑣 + 𝑣𝑤 2) (4) 𝐹𝑟 = 𝑠𝑖𝑔𝑛(𝑣)𝐶𝑟𝑚𝑣𝑔𝑐𝑜𝑠(𝜃) (5) where 𝑚 and 𝑚𝑣 are total mass acting on the wheels and mass of vehicle, 𝑎 and 𝑔 are acceleration and gravity, θ is road’s slope angle, 𝑣 and 𝑣𝑤 are vehicle and wind velocities, 𝜌𝑎 is air density of dry air at 20ᴼc, 𝐴𝑓 is vehicle’s frontal area, 𝐶𝑑 and 𝐶𝑟 are coefficients of aerodynamic drag and tire rolling resistance. total mass acting on the wheel is obtained from addition between mass of wheels and mass of vehicle. coefficient of rolling resistance is defined as follows [16]: 𝐶𝑟 = 0.01 �1 + 3.6 100 𝑣� (6) the torque acted on the vehicle is then calculated in accordance with this following equation: 𝑇 = 𝐹𝑡𝑟𝑇𝑠𝑐𝑎𝑙𝑙𝑖𝑛𝑔 (7) where t, 𝑇𝑠𝑐𝑎𝑙𝑙𝑖𝑛𝑔, and r are torque, its scale and radius of the wheels. the torque is scaled and then used to calculate the two voltages needed by the two dcms. it must be conducted due to figure 2. first algorithm of evs figure 1. block diagram of evs a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 80 small-scale configuration of the evs. the two voltages are obtained by referring to the dcm electric equation as follows: 𝑉𝑀1 = 𝑅𝑖𝑀1 + 𝐿 𝑑𝑖𝑀1 𝑑𝑡 + 𝑉𝑏𝑒𝑚𝑓 (8) 𝑉𝑀2 = 𝑅𝑖𝑀2 + 𝐿 𝑑𝑖𝑀2 𝑑𝑡 + 𝑉𝑏𝑒𝑚𝑓 (9) where 𝑉𝑀1 and 𝑉𝑀2 are both of dcm voltages, r is resistance, 𝑖𝑀1 and 𝑖𝑀2 are currents of dcms, l is inductance, 𝑉𝑏𝑒𝑚𝑓 is back electromotive force voltage. since the two motors are connected then 𝑉𝑏𝑒𝑚𝑓 produced will be equal and fulfilled: 𝑉𝑏𝑒𝑚𝑓 = 𝑘𝜔 (10) where k and ω are motor’s constant and dcm’s angular velocity. whereas, the rotational motion equation of the two mechanically connected dcms (no friction assumption) is the following: 𝑇𝑀1 + 𝑇𝑀2 = 𝐽𝛼 (11) where 𝑇𝑀1 and 𝑇𝑀2 are both of dcm torques, j is moment of inertia, α is angular acceleration. by using the connection between torque and current: 𝑖 = 𝑇 𝑘 (12) then from equations (8) and (9), under the assumption that the inductance value of each dcm was small, the followings are obtained: 𝑉𝑀1 = 𝑅 𝑇𝑀1 𝑘 + 𝑘𝜔 (13) 𝑉𝑀2 = 𝑅 𝐽𝛼−𝑇𝑀1 𝑘 + 𝑘𝜔 (14) these voltages are calculated in matlab/simulink and then sent to the dcms through microcontroller and h-bridge module in the form of pwm signals. in the same time, the battery-supercapacitor currents, batterysupercapacitors voltages, and dcm’s velocity are monitored through matlab/gui (figure 3). generally, the steps for running this evs are: (1) upload the evs code to the microcontroller; (2) run speed and road profiles codes in matlab/m-file; (3) run calculate voltages code in matlab/simulink; and (4) run matlab/gui code for monitoring. the sampling time for communication between evs and pc is determined by one second. after designing the evs, the next step is hardware implementation. hardware implementation of evs is conducted referring to block diagram in figure 1. the designed evs is shown in figure 4. iii. supercapacitor charging scheme a. supercapacitor module the supercapacitor used in this study is built in a module form. the module consisted of four cells of 100f/2.7v supercapacitor and formed in series, so the module has 25f/10.8v. based on nesscap [17], specifications of the supercapacitor are presented in table 1. to overcome the imbalance of voltage of the supercapacitor in series, the module is also equipped with a balancing circuit. a passive balancing circuit is used due to its simplicity in terms of design and implementation. figure 3. communications between evs and pc table 1. supercapacitor specifications [17] parameters values maximum internal resistance (esr) dc 11 a 13 mω rated current (25ºc) 21.4 a maximum current (25ºc) > 58.7 a maximum leakage current (12 h, 25ºc) 1.7 ma maximum stored energy (at 2.7 v) 364.5 joule (0.1013 wh) specified energy 4.5 wh/kg specified power (at matched load) 6.23 kw/kg volume 17.1 ml weight 22.5 g cycle life (25ºc) 500,000 cycles a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 81 the balancer is formed by installing a parallel resistor in each supercapacitor cell as shown in figure 5. in this way, the current resulted during the imbalance will flow to the resistor. the resistor value is 150 ω that obtained from following equation based on [8]. 𝑅 = 𝑉𝑠𝑐𝑚𝑎𝑘𝑠 10.𝐼𝑙𝑒𝑎𝑘𝑎𝑔𝑒 (15) where r was the resistance of balancing resistor, 𝑉𝑠𝑐𝑚𝑎𝑘𝑠 was maximum supercapacitor cell’s voltage, and 𝐼𝑙𝑒𝑎𝑘𝑎𝑔𝑒 was current leakage for each supercapacitor cell. b. proposed charging schemes the design of supercapacitor charging scheme is conducted by controlling the relays. the relays which used in this study are a single pole double throws (spdt) relays. the input of this component is obtained from microcontroller’s digital signal. when the input signal logic is high, the switch in common (c) pin will move from normally close (nc) pin to normally open (no) pin. the proposed supercapacitor charging scheme is shown in figure 6. the red arrow shows the discharging current, while green arrow shows the charging current. relay1 (r1) controls the switch between battery and supercapacitor, while the other (r2) controls between charging and discharging conditions. specifications of dcms that used are: r1 = 23 ohm; r2 = 21.51 ohm; l1 = l2 = 0.1 h; k1 = k2 = 0.055; b1 = b2 = 0.01 n.m.s; j1 = 0.0143 kg.m2; j2 = 0.0146 kg.m2.r is dcm resistance, l is dcm inductance, k is motor constant, b is friction constant, and j is moment of inertia. 1 and two are mentioned for dcm1 and dcm2. these parameters obtained from identification by direct experiment based on dcm’s parameter measurement rules. to regulate and step up the generator voltage, a dc/dc2 boost converter is placed between the generator and supercapacitor. the dc/dc2 is used to regulate generator’s voltage by 10.8 v during charging condition in accordance with supercapacitor’s maximum voltage, while the other (dc/dc1) is used to regulate battery and supercapacitor voltages by 12v while discharging condition occurs. dc/dc boost converter that used in this scheme has been integrated into lm2577-adj module. this converter works by switching the transistor using pwm signal. the connection between output and input voltages of this converter fulfilled this equation: 𝑉𝑜𝑢𝑡 = 𝑉𝑖𝑛 1−𝑃𝑊𝑀 𝑑𝑢𝑡𝑦 𝑐𝑦𝑐𝑙𝑒(%) (16) as an approach, the charging scheme occurs during the regenerative braking process of the electric vehicle. during the braking, the electric motor in the vehicle will act as a generator. energy produced by this generator will then be used as the electric energy source to charge the supercapacitor. this scheme occurs when the vehicle is at the downhill profile. it is implemented by applying no voltage to dcm1. the dcm1’s voltage which is calculated in matlab/simulink based on speed and road profiles is set to be zero, so the motors will be running by dcm2’s voltage. this strategy is done by detecting both of the motor voltages with this equation: figure 4. hardware implementation of evs figure 5. supercapacitor balancing circuit a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 82 𝑉𝑀1 = � 𝑉𝑀1, 𝑉𝑀1 ≥ 𝑉𝑀2 0, 𝑉𝑀1 < 𝑉𝑀2 � (17) 𝑉𝑀1 is dcm1 (vehicle) voltage and 𝑉𝑀2 is dcm2 (load) voltage. first condition (𝑉𝑀1≥𝑉𝑀2) is assumed when the vehicle at the uphill or flat road profile, while the second condition (𝑉𝑀1<𝑉𝑀2) is assumed when the vehicle at the downhill road profile. this algorithm is used because of the linearity connection between voltage and torque on electric vehicle. the supercapacitor charging occurs when the second condition is fulfilled. thus, the voltage produced by dcm1 (vehicle/generator) due to dcm2’s voltage is used as an electric energy source to charge the supercapacitor. the discharging condition is done when the supercapacitor voltage is defined ready. supercapacitor is defined ready if its voltage is larger than 5 v. this condition is conducted by sensoring the supercapacitor’s voltage. to overcome the relay’s chattering due to inaccuracies of sensor values when the supercapacitor voltage around ±5 v, the hysteresis control is used in the discharging condition. the values of lower and upper limits are 4 v and 6 v. variables which used are supercapacitor voltage ( 𝑉𝑠𝑐) and its change (d𝑉𝑠𝑐/dt). supercapacitor is defined ready if (1) 𝑉𝑠𝑐 >4 and d𝑉𝑠𝑐/dt <0, or (2) 𝑉𝑠𝑐 >6 and d𝑉𝑠𝑐/dt >0. figure 7 shows the flowchart of supercapacitor charging/discharging scheme. this flowchart is part of the overall flowchart of the hardware simulator. figure 6. proposed charging scheme figure 7. supercapacitor charging/discharging flow chart a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 83 iv. experimental result to have an appropriate simulation, the actual parameters of an electric vehicle are determined. this parameter is then used to calculate the voltages applied to dcms. the parameters of the vehicle are listed in table 2. in this simulation, the torque is scaled by 1:105. air density of dry air at 20ºc is determined by 1 kg/m3 and wind velocity is ignored for simplicity. this test is done with vehicle’s speed constant 36 km/h or 10 m/s or 166.7 rad/s with 0.3 m radius of the wheel. the road profile scenarios are one hill, two hills and trapezoidal with maximum slope angle respectively are 8.52º, -16.66º, and -11.3º. designs of road profiles are shown in figure 8 followed by its dcm voltages in figure 9. as shown in figure 9, the dcm1 (vehicle) voltage will be set to zero when dcm1 voltage is smaller than dcm2 voltage as equation (17). this (a) (b) (c) figure 8. road profiles and its slope angles: (a) one hill; (b) two hills; (c) trapezoidal table 2. testing parameters [18] parameters values mass of car 800 kg mass of wheel 5 kg mass of motor drive 5 kg radius of wheel 0.3 m gearbox ratio 1 : 5 frontal area 1.8 m2 coefficient of rolling resistance 0.01+3.6*velocity coefficient of aerodynamic drag 0.55 gravity 9.8 m/s2 (a) (b) (c) figure 9. dcm voltages for each road profile: (a) one hill; (b) two hills; (c) trapezoidal a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 84 condition is used for supercapacitor charging. the discharging condition is conducted when the vehicle is at uphill or flat road profile under condition supercapacitor voltage is defined ready. figure 10 and figure 11 show the supercapacitor charging currents and its voltages. different (a) (b) (c) figure 10. supercapacitor charging currents for three road profile: (a) one hill; (b) two hills; (c) trapezoidal (a) (b) (c) figure 11. supercapacitor voltages for each road profile: (a) one hill; (b) two hills; (c) trapezoidal a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 85 slope angle for each road profile resulted in different charging rate, which is shown by the different of supercapacitor charging current. average values of charging current for three road profiles respectively are -0.19 a, -0.21 a, and -0.20 a. the increases of supercapacitor voltage are also different for each road profile. values of the increase of supercapacitor voltage (during 25 seconds for similarity) respectively are 0.15 v, 0.17 v, and 0.16 v. based on these values above, it showed that the biggest charging current is found in the two hills road profile that has a maximum slope angle -16.66º. on the other hand, the smallest charging current is found on the one hill road profile with a maximum slope angle -8.52º. based on hardware experimental results, the steeper the hill slope, the higher the supercapacitor charging current, which produces a quicker charging rate. this fact is shown by the increase of supercapacitor voltage. as a consideration, current and voltage values obtained are also not much different (around of 0.01 a). it is due to slope angle difference between third road profiles less than 9º. in order to obtain the significant current difference, several ways may be taken, i.e. designing road profiles with higher slope angle or by making a vehicle’s mass become heavier. however, the higher slope angle value or mass of the vehicle, dcm voltages which are obtained will also be higher. v. conclusion a small-scale hardware evs has been built and a simple supercapacitor charging scheme has been designed and successfully implemented in the hardware. hardware experimental result shows that the averages of charging current are different and proportional with the maximum slope angle of the road profiles. it also has the impact on the change of supercapacitor voltage. this scheme is simple due to the evs utility and it is useful for education purpose. acknowledgement the authors would like to thank the laboratory for control and computer systems (lskk) institut teknologi bandung for supporting laboratory facilities in this research. references [1] a. khaligh and z. li, “battery, ultracapacitor, fuel cell, and hybrid energy storage systems for electric, hybrid electric, fuel cell, and plugin hybrid electric vehicles: state of the art,” ieee trans. veh. technol., vol. 59, no. 6, pp. 2806–2814, july 2010. [2] m. choi et al., “energy management optimization in a battery/supercapacitor hybrid energy storage system,” ieee transactions on smart grid, vol. 3, no. 1, pp. 463-472, march 2012. [3] s. pay and y. baghzouz., “effectiveness of battery-super capacitor combination in electric vehicles,” ieee bologna powertech conference, pp. 728-733, june 2003. [4] y. c. zhang et al., “study of supercapacitor in the application of power electronics,” wseas transaction on circuits and systems, vol. 8, issue 6, pp. 508-517, issn: 1109-2734, june 2009. [5] a. b. cultura and z. m. salameh, “modeling, evaluation and simulation of a supercapacitor module for energy storage application,” international conference on computer information systems and industrial applications (cisia), pp. 876-882, 2015. [6] m. s. w. chan et al., “effective charging method for ultracapacitors,” journal of asian electric vehicles, vol. 3 no. 2, pp. 771-776, december 2005. [7] s. ban et al., “charging and discharging electrochemical supercapacitors in the presence of both parallel leakage process and electrochemical decomposition of solvent,” electrochimica acta, vol. 90, pp. 542-549, 2013. [8] y. diab et al., “comparison of the different circuits used for balancing the voltage of supercapacitors: studying performance and lifetime of supercapacitors,” esscap, lausanne, switzerland, nov. 2006. [9] y. qu et al., “overview of supercapacitor cell voltage balancing methods for an electric vehicle,” ecce asia downunder (ecce asia) ieee, 2013. [10] a. botelho and w. price, “protodrive: rapid prototyping and simulation for ev powertrains,” ese 350: embedded systems/microcontroller laboratory, university of pennsylvania, 2012. [11] s. diaz et al., “protodrive: an experimental platform for electric vehicle energy scheduling and control,” dept. electrical and system engineering, university of pennsylvania, 2012. [12] s. diaz, “protodrive: simulation of electric vehicle powertrains,” nsf summer undergraduate fellowship in sensor technologies, binghamton university, 2012. a.r. al tahtawi and a.s. rohman. / j. mechatron. electr. power veh. technol 07 (2016) 77-86 86 [13] w. price, “protodrive,” project technical note, 2012. [14] a. mulay et al., “protodrive: rapid prototyping platform for electric vehicle powertrain,” project technical note, 2013. [15] a. r. al tahtawi and a. s. rohman, “simple supercapacitor charging scheme in electrical car simulator using direct current machines,” proceeding of the 5th ieee international conference on electrical engineering and informatics (iceei) bali, pp. 562-567, 2015. [16] m. ehsani et al., “modern electric, hybrid electric, and fuel cell vehicles fundamentals, theory, and design,” first ed., crc press llc, 2005. [17] nesscap 100f/2.7f ultracapacitor datasheet, nesscap co., ltd. 2003. [18] e. schaltz, “electric vehicle design and modeling,” aalborg university, denmark, intech open acces publisher, 2011. i. introduction ii. electric vehicle simulator iii. supercapacitor charging scheme a. supercapacitor module proposed charging schemes iv. experimental result v. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.33-39 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. increasing efficiency of a 33 mw otec in indonesia using flat-plate solar collector for the seawater heater iwan rohman setiawan a, *, irwan purnama a, abdul halim b a technical implementation unit for instrumentation development, indonesian institute of sciences (lipi) kompleks lipi gd. 30, jl. sangkuriang, bandung, indonesia b department of electrical engineering, faculty of engineering, university of indonesia kampus baru ui depok 16424, indonesia received 19 october 2016; received in revised form 14 june 2017; accepted 21 june 2017 published online 31 july 2017 abstract this paper presents a design concept of ocean thermal energy conversion (otec) plant built in mamuju, west sulawesi, with 33 mwe and 7.1% of the power capacity and efficiency, respectively. the generated electrical power and the efficiency of otec plant are enhanced by a simulation of a number of derived formulas. enhancement of efficiency is performed by increasing the temperature of the warm seawater toward the evaporator from 26˚c up to 33.5˚c using a flat-plate solar collector. the simulation results show that by increasing the seawater temperature up to 33.5˚c, the generated power will increase up to 144.155 mwe with the otec efficiency up to 9.54%, respectively. the required area of flat-plate solar collector to achieve the results is around 6.023 x 106 m2. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: enhanced efficiency; otec plant; flat-plate solar collector; mamuju west sulawesi i. introduction an ocean thermal energy conversion (otec) power generation utilizes the temperature differences between surface layer and deeper layers (800–1000 m) of the sea where the operation temperature difference is generally around 20°c or more. considering the temperature levels at one kilometer depth, the temperature difference will be relatively constant at 4°c so that otec is particularly suitable for mean surface temperatures around 25°c. this small temperature difference is converted into usable electrical power through the heat exchangers and turbines [1, 2]. moreover, otec plant can also produce another output such as fresh water, refrigeration, hot water, and hydrogen [2, 3, 4, 5]. otec plant is principally designed for tropical waters such as in indonesia, which has a high temperature difference between the temperature of the seawater at the surface and at a depth of 1000 meters [1, 2, 6, 7]. figure 1 shows the temperature differences in the tropical ocean ranges from 22⁰c to 24⁰c. potential ocean thermal power plant in indonesia is ranked number three after the united states and australia. indonesia has a coastline length of 95.181 km with approximately 70% of the potential otec. therefore, the otec power generation of 222 gw can be estimated from the coastline length of 66.627 km with the generated capacity of 100 mw. thus, the potential electrical estimation of otec in indonesia is amounted to 15.500 twh [8]. the feasibility of otec power plant was studied for mamuju, west sulawesi. mamuju is located close to the sea that has a depth of 1000 meters. the system design of otec is island based which has some advantages such as the integration of the cooling system, water desalination, aquaculture, and agriculture [9]. figure 2 shows the studied construction site for otec in mamuju and figure 3 presents an otec island based systems. * corresponding author. tel: +62 22 250 3053 e-mail address: iwan_r_setiawan@yahoo.com https://dx.doi.org/10.14203/j.mev.2017.v8.33-39 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.33-39 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.33-39&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 34 the cycle otec in mamuju uses closed-cycle, as shown in figure 4, where the generated electrical power (gross) and carnot efficiency is designed for 33 mw and 7.283%, respectively [3, 7, 9]. carnot efficiency of otec is determined by the temperature difference between the warm seawater and the cold seawater, so that otec has the maximum efficiency ranged from 7.5% to 8% [10]. there is another way to improve the efficiency of otec such as by increasing the surface temperature of the seawater using a solar collector, technique that was introduced by ahmadi et al. [4]. a solar collector on warm seawater pipe that enters the evaporator was added into otec 72.49 kw (net) [4]. aydin added a heat exchanger with the solar collector on warm seawater pipe that enters the evaporator or evaporator exit through the turbine on otec 100 kw [11]. yamada et al. analyzed two configurations of a solar collector installation on an ordinary closed-cycle otec. the solar collector heats the warm seawater entering the evaporator for the first configuration, while for the second configuration, the solar collector heats the working fluid after exiting the evaporator [12]. husada et al. improved the efficiency of otec by the technique of double-stage rankine cycle flow [13]. this paper presents analysis of otec to increase the power capacity of 33 mw which is designed based on the calculation by yeh et al. [7, 14] in this study, a flat-plate solar collector in warm seawater pipe that enters the evaporator without a heat exchanger is added to the otec plant in mamuju, west sulawesi. ii. methodology a. kalina cycle the designed otec that is studied to be implemented in west sulawesi is a type of kalina closed-cycle as shown in figure 4. a closed-cycle otec with a higher temperature of surface water is used to provide heat to a working fluid with a low boiling temperature hence a higher vapor pressure is provided. figure 1. potential otec in the world [6] figure 2. location study of otec plant in mamuju [9] figure 3. illustration of otec island based system at honolulu, hawaii [9] i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 35 ammonia is commonly used as a working fluid. its vapor drives a generator that produces electrical power. after driving a generator, the working fluid vapor is then condensed by the cold water from the deep ocean and pumped back in a closed system. the kalina cycle is a variation of a closed-cycle otec, where by instead of pure ammonia, a mixture of water and ammonia is used as the working fluid. such a mixture lacks of a boiling point but it has a boiling point trajectory [2, 9]. furthermore, matsudah et al. had used an ammonia-water mixture as the working fluid. this working fluid is flow to the evaporator to be partially evaporated through heat transfer process between warm seawater and working fluid. thus, wet vapor is generated. the wet vapor is flowed to the separator to separates liquid from the wet vapor. the liquid is stored in the separator tank, and the rest of vapor (dry vapor) is finally flow to turbine to generate electrical power so that the liquid level in the separator controlled [14]. the equation for otec plant as shown in figure 4 is written as follows [3, 7, 9, 15]: ṁw = ( πd2 4 ) ρv (1) where 𝑚𝑤 is mass flow rate of warm seawater or cold seawater in the pipe (kg/s), ρ is seawater density = 1025 kg/m3, d is pipe diameter (m), and v is the velocity of seawater flowing in the pipe (m/s). based on otec designs for real implementation in mamuju, pipe diameter for warm seawater and for cold water are 8.9 m and 7.9 m, respectively and v is 2.03 m/s. furthermore, the heat transfer rate for the warm seawater in the evaporator can be calculated using the following equation: qe = ṁwwcpw(twwi−twwo ) (2) where qe is heat transfer rate in evaporator (j/s), cpw is specific heat of seawater as much as 4000 j/kg.c, twwi is input temperature of warm seawater (assumed to be constant at 26c), twwo is output temperature of warm seawater approximately of 23.8⁰c, 𝑚𝑤𝑤 is mass flow rate of warm seawater (calculated using equation (1)) as much as 129380.723 kg/s. mass flow rate of working fluid in the evaporator is calculated by the following equation: ṁwf = qe (h1−h4) (3) where ṁwf is mass flow rate of working fluid (ammonia) (kg/s), h1 is output enthalpy of ammonia and h4 is input enthalpy of ammonia. the ammonia exiting the evaporator has a higher temperature, is then used to rotate turbines. the ammonia vapor quality is calculated by the following equation: x = (s2̇−s2_l) (s2_v−s2_l) (4) where x is ammonia vapor quality, s2 is ammonia entropy out of the turbine (j/kg.k), s2_l is the entropy of saturated liquid ammonia at condensation temperature (j/kg.k), and s2_v is the entropy of saturated ammonia vapor at the condensation temperature (j/kg.k). furthermore, the enthalpy of ammonia vapor exiting the turbine, h2, (j/kg), is obtained using the following equation: h2 = (1 − x)h2_l + xh2_v (5) where h2_l is enthalpy saturated liquid ammonia out of the turbine (j/kg), h2_v is enthalpy saturated vapor ammonia exiting the turbine (j/kg). the electrical power is generated by connecting the turbine to an electric generator. the power generated by the turbine, wt (w), is calculated by the following equation: wt = ṁwf(h1 − h2)η (6) where η is a turbine efficiency which is assumed about 0.896 and h2 is enthalpy of ammonia vapor exiting the turbine. ammonia vapor exit the turbine is then cooled by the cold seawater in the condenser to become liquid. the value of the heat transfer rate in condensers, qc (j/s), is obtained from the following equation: qc = ṁwf(h2 − h3) (7) where h3 is the enthalpy of output ammonia liquid from condenser (j/kg). figure 4. otec plant closed-cycle [12] i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 36 equation (7) can also be written as follows: qc = ṁwccpw(tcwo − tcwi) (8) where ṁwc is mass flow rate of input cold seawater into condenser (kg/s), tcwi is input cold seawater temperature into condenser (4.22⁰c) and tcwo is output cold seawater temperature from condenser (6.89c). b. seawater heater using flat-plate solar collector as shown in figure 5, to increase the efficiency of otec, the warm seawater temperature is increased before entering the evaporator using a flat-plate solar collector. the maximum possible useful energy gain (heat transfer) in a solar collector occurs when the whole collectors are at the inlet fluid temperature. therefore, heat losses to the surroundings are then at a minimum. the collector heat removal factor times this maximum possible useful energy gain is equal to the actual useful energy gain, qu [16]. the value of qu (w), is obtained by the following equation: qu = acfr[s − ul(twwi − ta)] (9) where ac is the area of flat-plate solar collector (m 2), s is the solar irradiance (w/m2), and fr is the heat removal factor (dimensionless), obtained by the following equation: fr = ṁwẇ cp acul [1 − exp (− aculf ′ ṁwẇ cp )] (10) where ul is the overall heat loss coefficient for collector which is assumed by 0.8 w/m2c, and f’ is the collector efficiency factor which is assumed by 0.841. the magnitude of the seawater temperature that comes out of the flat-plate solar collector, tso, (°c), is obtained based on the following equation: qu = ṁwẇ cpw(tso − twwi) (11) by modifying equation (11), the following equation is obtained: 𝑇𝑆𝑂 = 𝑇𝑤𝑤𝑖 + qu ṁwẇ cpw (12) the value of otec carnot efficiency is calculated using the following equation: η = twwi−tcwi twwi (13) where η is carnot efficiency, twwi and tcwi are in kelvin. iii. result and discussion simulations are performed by raising the temperature of the warm seawater flowing in the pipe toward the evaporator, started from temperature 26c. the increasing of the warm seawater temperature is caused by the irradiation of sunlight received by the flat-plate solar collector. the maximum temperature of the water is limited to 33.5c, because the higher temperature can result in instability when otec system is connected to a single machine infinite bus [7]. a. determining area of flat-plate solar collector using equation (11), heat transfer rate to raise the temperature of warm seawater from 26c to 33.5c, qu, is calculated as much as 3.881 x 109 j/s. the heat removal factor should be calculated to determine the area of the flat-plate solar collector. by modifying equation (10), the heat removal factor can be calculated as follows: ln fr = ln ṁwẇ cp acul [1 − exp (− aculf ′ ṁwẇ cp )] (14) then, equation (14) can be simplified as follows: ln fr = − aculf ′ ṁwẇ cp (15) and, now fr can be written as follows: fr = exp (− aculf ′ ṁwẇ cp ) (16) by substituting equation (16) to equation (9), the formula of qu is obtained as follow: qu = ac exp (− aculf ′ ṁwẇ cp ) [s − ul(twwi − ta)] (17) figure 5. the temperature of the warm seawater on otec plant raised using a flat-plate solar collector [12] i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 37 by assuming the peak sun irradiation (s) as much as 1000 w/m2 and substituting this value to equation (17), it is obtained the flat-plate solar collector area, ac, as much as 6.023 x 106 m2. b. the increase of warm seawater temperatures the irradiation of sunlight is absorbed by a flatplate solar collector throughout the day to increase warm seawater temperature. by assuming the data of solar irradiation [17] that is collected from mamuju using matlab, the obtained curve s sunlight irradiation in w/m2 versus time for the entire day as shown in figure 6 is substituted into equation (17). the obtained value of ac is then substituted into equation (9) and equation (10). therefore, the increase of seawater temperature from the flat-plate solar collector is obtained by using equation (12), as shown in figure 7. figure 6 shows that the irradiation of sunlight is approximately between 6 a.m. until 6 p.m. and the peak hour is about at 12 p.m. with approximately irradiation of 1000 w/m2 to increase the seawater temperature from 26c to 33.5˚c at the peak hour, as shown in figure 7. c. output power of turbine as a result of changes in warm seawater temperatures, power is generated by the turbine generator, the value of 𝑇𝑠𝑜 is substituted into equation (2) where 𝑇𝑤𝑤𝑖 is equal to 𝑇𝑠𝑜 . by assuming the values of 𝑇𝑤𝑤𝑜 , 𝐻1 , 𝐻2 , and 𝐻4 are constant, and using equation (6), the changes of turbine power generator due to changes in warm seawater temperatures are obtained as shown in figure 8. figure 8 shows that due to the increasing of warm seawater temperatures from 26c up to 33.5c, the output power of turbine is increase from 33 mw up to 144 mw. otec efficiency also increases from 7.1% up to 9.54% as shown in figure 9. the increasing of warm seawater temperatures resulting in an increasing of power output of the turbine, based on equation (3) and equation (6), it requires the increasing of working fluid mass flow rate that is proportional to changes in the seawater temperatures as shown in figure 10. the simulation results are also shown in table 1. the simulation results in figure 10 are obtained by assuming that heat losses from piping and other auxiliary components are negligible, and enthalpy of input ammonia into evaporator, output ammonia from evaporator, and output ammonia from turbine are constant for every change of seawater temperature. 200 400 600 800 1000 s o la r ir ra d ia n c e ( w /m 2 ) 0 5 10 15 20 25 0 time (hour) figure 6. irradiation of sunlight throughout the day [12] time (hour) 0 5 10 15 20 25 24 26 28 30 32 34 s e a w a te r t e m p e ra tu re ( o c ) figure 7. correlation between seawater temperatures and time. i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 38 table 1. simulation results in enhancing otec efficiency parameter unit flat-plate solar collector area, ac 6.023 x 10 6 (m2) warm seawater temperature, tso 26 – 33.5 (⁰c) turbine output power, wt 33 –144.155 (mw) working fluid mass flow rate, ṁwf 883-3885 (kg/s) warm seawater mass flow rate, ṁww 129380.723 (kg/s) output enthalpy of ammonia from evaporator , h1 1462.6 (kj/kg) output enthalpy of ammonia vapor from turbine, h2 1425.5 (kj/kg) input enthalpy of ammonia into evaporator, h4 225.196 (kj/kg) efficiency, η 7. 1 – 9. 54 (%) 100 150 200 seawater temperature ( c ) t u rb in e o u tp u t p o w e r ( m w ) 24 26 28 30 32 34 0 50 o figure 8. correlation between output power of turbine and warm seawater temperatures 298 300 302 304 306 308 0 2 4 6 8 10 seawater temperature (k) e ff ic ie n c y ( % ) figure 9. effect the increasing of seawater temperatures on otec efficiency 1000 2000 3000 4000 24 26 28 30 32 34 0 working fluid mass flow rate (kg/s) turbine output power (mw) w o rk in g f lu id m a s s f lo w r a te a n d tu rb in e o u tp u t p o w e r o seawater temperature ( c) figure 10. the effect of the increasing of warm seawater temperatures on the working fluid mass flow rate and turbine output power i.r. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 33–39 39 iv. conclusion as the effect of the increasing of input temperature of warm seawater into evaporator from 26c to 33.5c using a flat-plate solar collector with an area of 6.023 x 106 m2, the power generated by the turbines increase from 33 mwe to 144.155 mwe and the otec efficiency also increase from 7.1% to 9.54%. the increase and decrease output power of turbine, as well as the efficiency of otec, is a function of the mass flow rate of the working fluid which is proportional to the increase and decrease of seawater temperature that comes out of the flat-plate solar collector. acknowledgement this paper is the continuation of author’s master research in university of indonesia. the authors would like to thank to indonesian institute of sciences (lipi) and ministry of research and technology for author’s master scholarships. references [1] w. h. avery, c. wu, “renewable energy from the ocean: a guide to otec”, oxford university press, new york, 1994. [2] r. kempener, f. neumann, ”ocean thermal energy conversion, technology brief”, irena ocean energy technology brief 1, 2014 [3] a. p. yassen, “rancang bangun pembangkit listrik dengan sistem konversi energi panas laut (otec)” (tugas akhir), institut teknologi sepuluh november surabaya, 2010. [4] p. ahmadi et al., “performance assessment of a novel solar and ocean thermal energy conversion based multigeneration system for coastal areas”, journal of solar energy engineering, asme, vol. 137/011013-1, february 2015. [5] p. ahmadi et al., “multi-objective optimization of an ocean thermal energy conversion system for hydrogen production”, international journal of hydrogen energy. elsivier, volume 40, issue 24, pages 7601–7608, 29 june 2015. [6] energy island avaliable: http://www.solarenergyltd.net/ energy%20island.htm [accessed: 03 may 2016]. [7] r. i. setiawan, “analisa pengaruh kenaikan temperatur permukaan air laut terhadap kestabilan sistem pembangkit listrik tenaga panas laut”, (master tesis), universitas indonesia, 2013. [8] d. achiruddin, “strategy to develop indonesian ocean thermal energy conversion (otec)”. [online]. avaliable: http://www.energy-indonesia.com/03dge/otec%20bali.pdf. [accessed: 03 may 2016]. [9] a.y. rahman, “otec ocean sustainable energy”, (tugas akhir). institut teknologi bandung, 2007. [10] what is otec http://www.otecnews.org [accessed: 04 may 2016]. [11] h. aydin, “performance analysis of a closed-cycle ocean thermal energy conversion system with solar preheating and superheating”, (thesis), university of rhode island, 2013. [12] n. yamada et al., “thermal efficiency enhancement of ocean thermal energy conversion (otec) using solar thermal energy”, 4th international energy conversion engineering conference and exhibit (iecec), american institute of aeronautics and astronautics, san diego, california, 26 29 june 2006. [13] e. kusuda et al., “performance test of double-stage rankine cycle experimental plant for otec”, 6th bsme international conference on thermal engineering, icte 2014, procedia engineering 105, 713 – 718, 2015. [14] y. matsudah et al., “controller design for liquid level control of separator in an otec plant with uehara cycle considering disturbances”, 2015 15th international conference on control, automation and systems (iccas 2015), ieee, 2015. [15] r. h. yeh et al., “maximum output of an otec power plant”, technical notes, ocean engineering , elsevier, 2004. [16] a. j. duffie, a. w. beckman, “solar engineering of thermal processes”, john wiley & sons, inc, 2013. [17] calculation of solar insolation. http://www.pveducation.org/ pvcdrom/properties-of-sunlight/calculation-of-solar-insolation. [accessed: 04 may 2016] mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.81-88 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. implementation of a lifepo4 battery charger for cell balancing application amin*, kristian ismail, abdul hapid research centre for electrical power and mechatronics, indonesian institute of sciences jl. sangkuriang 21, building 20, 2nd floor, bandung, west java 40135, indonesia received 14 may 2018; received in revised form 26 november 2018; accepted 28 november 2018 published online 30 december 2018 abstract cell imbalance always happens in the series-connected battery. series-connected battery needs to be balanced to maintain capacity and maximize the batteries lifespan. cell balancing helps to distribute energy equally among battery cells. for active cell balancing, the use of a dc-dc converter module for cell balancing is quite common to achieve high efficiency, reliability, and high power density converter. this paper describes the implementation of a lifepo4 battery charger based on the dc-dc converter module used for cell balancing application. a constant current-constant voltage (cc-cv) controller for the charger, which is a general charging method applied to the lifepo4 battery, is presented for preventing overcharging when considering the nonlinear property of a lifepo4 battery. the prototype is made up with an input voltage of 43 v to 110 v and the maximum output voltage of 3.75 v, allowing to charge a lifepo4 battery cell and balancing the battery pack with many cells from 15 to 30 cells. the goal is to have a lifepo4 battery charger with an approximate power of 40 w and the maximum output current of 10 a. experimental results on a 160 ah lifepo4 battery for some state of charge (soc) shows that the maximum battery voltage has been limited at 3.77 v, and maximum charging current could reach up to 10.64 a. the results show that the charger can maintain battery voltage at the maximum reference voltage and avoid the lifepo4 battery from overcharging. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: cell balancing; constant current-constant voltage (cc-cv); dc-dc converter module; lifepo4 battery. i. introduction recently, li-ion batteries have been widely used in different applications, such as portable electronic devices and electric vehicles, due to their several advantages of high energy density, low self-discharge, long life cycles, and no memory effect [1][2]. the life cycles of li-ion batteries are affected by undercharging or overcharge condition. it is because overcharge would damage the physical component of the batteries, and undercharge could reduce the energy capacity of the batteries. in electric vehicle application which requires high power and energy, the lifepo4 traction battery needs to be connected in series or series-parallel in order to increase its energy potential. this traction battery is the most critical part of an electric vehicle because it affects the driving range, and also the battery types mainly influence the cost of the vehicle. since the internal impedance of each battery is not identical, a seriesconnected battery needs to be balanced to maintain their capacity. it become more difficult to charge when the batteries are configured in a series. the battery pack tends to imbalance after consecutive charge/discharge process [3]. cell imbalance always occurs in the seriesconnected battery which leads in the degradation of an individual cell. furthermore, the capacity of the battery pack will be reduced quickly and shorten the batteries lifespan. a battery management system (bms) to observe lifepo4 batteries is crucial for safety and operational reasons. it avoids cell breakdowns caused by undercharging or overcharging, keeps the balance of the voltage among battery cells, each cell in safe operating condition, and monitors the battery temperature [4][5]. one of the most crucial features of a bms is cell balancing. cell balancing helps to dispart energy equally among battery cells. * corresponding author. tel: +62 823 1721 1215 e-mail address: amin_hwi@yahoo.co.id; amin@lipi.go.id https://dx.doi.org/10.14203/j.mev.2018.v9.81-88 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.81-88 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.81-88&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 82 passive and active cell balancing are two types of cell balancing method. the major distinction between both methods is that passive cell balancing removing the extra energy of the most charged cell through the passive element (resistor) and the active cell balancing is transferring the energy of the strong cell to the weak cell. active cell balancing methods work to reduce the high energy losses observed in passive cell balancing methods. according to the active element used for storing the energy, active cell balancing has various topologies namely capacitor based, inductive based, and converters based [6]. for converter based active cell balancing, the dc-dc converter module is commonly used to achieve high efficiency, reliability, and high power density converter. this dc-dc converter module is used to charge every lifepo4 battery in the battery pack to balance the battery pack. in other words, the dc-dc converter module acts like a lifepo4 battery charger. in [6], dc-dc converter modules were used for balancing among battery modules through the auxiliary battery with maximum current rating of 6 a. a method using a single equalizer circuit that can be switched to a target cell via a set of sealed relays was proposed in [7] and [8] for balancing battery cells. in this method, a dc-dc converter module was used for cell balancing with a maximum current rating from 4 to 5 a. in [9] and [10], a dc-dc converter module was used for balancing the selected weak cell via a matrix of electronic relays with a balance current close to 6 a. the previous studies explained that the dc-dc converter module could charge or balance the battery with a maximum current rating of 6 a. in this work, the dc-dc converter module was designed to charge or balance lifepo4 battery with maximum current rating of 10 a. this bigger current rating is used to achieve faster balancing time in the electric vehicle battery. this study discusses the implementation of a lifepo4 battery charger for cell balancing application with a maximum current rating of 10 a. to obtain a clear and comprehensive analysis of the effect of 10 a of current rating, the components value of the lifepo4 battery charger circuit was calculated and followed by efficiency calculation. in order to validate the charger circuit, the charger prototype was build and followed by an experimental test. the detailed analysis of the voltage and current characteristics of the lifepo4 battery with the different initial state of charge are discussed as the focus of this study. ii. materials and methods in lifepo4 batteries applications, a battery system contains the battery and battery management system (bms). one important requirement for lifepo4 bms is to observe the voltage across each cell when more than one cell is connected in series to assure charge equalization and voltage balancing of the cells. a protection circuit is usually added to the charger circuit to manage cells voltage. lifepo4 batteries have very crucial charging requirements that must be fulfilled during charging to assure safe operating condition. battery charging plays an important role in the bms, where the charging method has a strong effect on battery performance and life cycles. a charger has three main functions: supplying charge to the battery; optimizing the charge rate; and stopping the charge [1]. the charge can be supplied to the battery through a different charging method, depending on the battery chemistry. for lifepo4 batteries, a constant current-constant voltage (cc-cv) charging method is very popular and commonly used in charging lifepo4 batteries because of implementation easiness and simplicity [1][11][12]. in this paper, a constant current-constant voltage (cc-cv) method was used for preventing overcharging of the lifepo4 battery. this cc-cv method also the most widely adopted charging method to develop a charger for a li-ion battery with some improvement methods. in [2] and [13], li-ion battery internal resistance compensation is used in cc-cv based charger. not only for low power li-ion charger, but the cc-cv method was also used for high power li-ion battery charger [14]. other improvement methods for cc-cv based charger are using on-off duty cycle control zero computational algorithms [15], and inductive power transmission with temperature protection [16]. the cc-cv based charger was also used in different charger topology, they are llc resonant converter [17] and pfc sheppard taylor converter [18]. lifepo4 batteries require a constant current (cc) to charge the battery until the battery voltage achieves a predefined safety limit (maximum charging voltage) at which a constant voltage (cv) begins. then, the charging voltage is kept at a maximum charging voltage, while simultaneously, the charging current is exponentially reduced as shown in figure 1. a constant voltage (cv) charging is used to limit the current and thus prevent the battery from overcharge. the charging process ends when the charging current achieves a small preset current. the charging curve of the cc-cv charging method is shown in figure 1 [11]. a. lifepo4 battery charger circuit the dc-dc converter module is voltage regulating device and makes it feasible to utilize them as efficient high-power current sources because of their wide trim range. current regulation of the dc-dc converter can be performed through a current-sense resistor and the addition of an external control loop. the isolated dcdc converter module circuit that is used as a lifepo4 battery charger is shown in figure 2 [19]. figure 1. charging curve of the cc-cv method amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 83 from figure 2, the output voltage of the dc-dc converter can be adjusted by controlling the sc pin. in order to meet the low-cost requirement, an analog circuit was used to control the dc-dc converter module. figure 3 shows the detail of the lifepo4 battery charger circuit based on an analog circuit [20]. the lifepo4 battery charger was created based on isolated dc-dc converter module with an input voltage of 43 v to 110 v, allowing to charge a lifepo4 battery cell and balancing the battery pack with many cells from 15 to 30 cells. thus, a lifepo4 battery charger with an approximate power of 40 w, and with a maximum output current (imax) of 10 a was obtained. table 1 summarizes the charger specifications. considering a lifepo4 battery with a nominal voltage of 3.2 v, the selected float voltage (vfloat) is 3.75 v. the required maximum output voltage of the dc-dc converter module (vmax) is given as: vvvv ffloat 05.43.075.3max  (1) where vf is a voltage drop on the schottky protection rectifier d2. according to [20], the components value of the lifepo4 battery charger were calculated and summarized in table 2. b. lifepo4 battery charger efficiency based on lifepo4 battery charger circuit as shown in figure 3, the components with significant power dissipation in this charger system are the dc-dc converter module, the shunt resistor (prshunt), and the schottky diode (pd2). in this derivation of an estimate of lifepo4 battery charger efficiency, other sources of power dissipation will be neglected. at the end of the constant current (cc) phase, the output power to the battery (pout) will be: max max 4.05 10 40.5outp v i w     (2) figure 2. dc-dc converter module circuit figure 3. lifepo4 battery charger circuit table 2. components value of the lifepo4 battery charger component value r1 10 kω r2 357 ω r3 47 kω r4 4.7 kω r5 14.7 kω r6 20 kω r7 100 kω r8 20 kω r9 20 kω r10 20 kω r11 22 ω rshunt 12.5 mω c1 470 nf c2 680 nf c3 470 pf d1 bat85 d2 mbr1545 u1 lm10 u2 tl431 table 1. charger specifications parameters values input voltage 43 to 110 v output voltage 4.05 v no. li-ion cells 15-30 cells max output current 10 a max power 40 w amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 84 the power dissipated on the schottky diode d2 (pd2) and the shunt resistor (prshunt) can be calculated using equation (3) and (4). 2 max 0.3 10 3d fp v i w     (3) 2 2 max 10 0.0125 1.25rshunt shuntp i r w     (4) therefore, the output power from the dc-dc converter module (ptot) is: w pppp rshuntdouttot 75.4425.135.40 2   (5) considering a worst-case efficiency of 81.3% for the dc-dc converter module [21], the input power of the dc-dc converter module (pin) will be: w efficiency p p totin 043.55 813.0 75.44  (6) the overall efficiency of the lifepo4 battery charger (efftot) is: %58.737358.0 043.55 5.40  in out tot p p eff (7) iii. results and discussions a. charger prototype according to the lifepo4 battery charger specification described in section ii, the circuit will be implemented using vicor power v72c5e100bl dcdc converter module. a lifepo4 battery charger prototype has been implemented to validate the effectiveness of the charger design. the prototype of the lifepo4 battery charger is shown in figure 4 and experimental test for charge a lifepo4 battery has been carried out as shown in figure 5. from figure 4, the core of the charger circuit is an lm10 (u1) operational amplifier and voltage reference. a shunt regulator (u2) is adjusted to supply a voltage of 2.5 v from the output of the dc-dc converter module to the lm10. the op-amp (u1a) acts as an error amplifier and is designed as an integrator using capacitor c1 and resistor r4. resistor r9 and r10 are used to set the internal reference voltage at the noninverting op-amp input. subsequently, the reference voltage is compared with the current-sense resistor (rshunt) voltage to control the load current. the op-amp (u1a) activates the schottky diode (d1) cathode to adjust the dc-dc converter module output. an initial condition when a voltage is off can be done by fully discharging the voltage across capacitor c1 using resistor r3. the diode d1 with a low forward voltage increased the output voltage of the dc-dc converter module and used to avoid the op-amp (u1a) from overdriving the sc pin. the resistor r1 adjust the float voltage by decreasing the converter maximum output voltage. the battery voltage (b1) rise to a constant float voltage as the increases of battery state of charge. the diode d2 connected series to the positive terminal of the battery to isolate the output of the dc-dc converter module in case of malfunction and avoid the battery activates the circuit when the charger is off. b. experimental test figure 5 shows the experimental apparatus to test the charger prototype. it consists of a power supply unit as an input of the charger. this power supply unit is used to replace the voltage of the battery pack in the battery management system with a number of the cell from 15 to 30 cells. a current sensor based on acs712 was used to measure the current to the 160ah lifepo4 battery. the charge current and voltage of the lifepo4 battery was stored using lgr-5327 datalogger to know the behavior and effectiveness of the charger. c. testing result the lifepo4 battery charger was used to charge a 160ah lifepo4 battery with a different initial voltage that represents a different state of charge (soc) to test the cc-cv charging method and simulate the battery balancing system. figure 6, figure 7, and figure 8 present cell voltage and charging current for some charging process with different initial voltage. experimental results show that at the beginning of the figure 4. lifepo4 battery charger prototype amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 85 charging process, the lifepo4 battery was charged with certain current and decrease slowly. at the end of the charging process (cv stage), the lifepo4 battery voltage was kept at the maximum reference voltage and avoid the battery from overcharging. in figure 6, the initial voltage of the lifepo4 battery was 2.8 v. at the beginning of the charging process, the charge current was 10.64 a. the charge current was decreased slowly, and at the time of 27 hours, the charge current was 0.78 a, and the lifepo4 battery voltage was 3.64 v. at the end of the charging process, the lifepo4 battery voltage was maintained at 3.77 v. in figure 7, the starting voltage of the lifepo4 battery was 3.27 v. in the start of the charging process, the charge current was 7.54 a. the charge current was also decreased slowly, and at the time of 21 hours, the charge current was only 0.42 a and the lifepo4 battery figure 6. charging process with initial voltage of 2.8 v figure 7. charging process with initial voltage of 3.27 v 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 0 2 4 6 8 10 12 0 5 10 15 20 25 30 35 40 45 50 v o lt a g e ( v ) cu rr e n t (a ) time (h) icharge (a) vbat (v) 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 0 1 2 3 4 5 6 7 8 0 5 10 15 20 25 30 35 40 45 50 v o lt a g e ( v ) cu rr e n t (a ) time (h) icharge (a) vbat (v) figure 5. experimental test amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 86 voltage was 3.66 v. at the end of the charging process, the lifepo4 battery voltage was maintained at approximately 3.78 v. in figure 8, the initial voltage of the lifepo4 battery was higher than the previous two experiments, which was 3.36 v. at the beginning of the charging, the charge current was 5.87 a. the charge current was dropped slowly and at the time of 8 hours, the charge current was only 0.6 a and the lifepo4 battery voltage was 3.66 v. at the end of the charging process, the lifepo4 battery voltage was maintained at 3.78 v. figure 9 shows the lifepo4 battery voltage for various charging process with different initial voltage to simulate cell balancing. the experimental result shows that the lifepo4 batteries voltage can be balanced at 3.77 v at the end of the charging process and avoid the lifepo4 batteries from overcharging. in this experimental results, the dc-dc converter module was able to charge the lifepo4 battery with a maximum current rating of 10.64 a. the charge current is bigger than previous papers which only can charge the battery with a maximum current rating of 6 a. this bigger current rating is used to achieve faster balancing time in the electric vehicle battery. d. constraints and future works in this paper, the lifepo4 battery charger was used especially for battery balancing in the battery management system. further works could be focused on verifying the effectiveness of the charger equipment. the charger will need to be tested on the battery management system to balance the battery pack with a larger number of installed cells. the cells could be varied from 15 to 30 cells. iv. conclusion a 40 w lifepo4 battery charger was successfully designed based on dc-dc converter modules. the charger was used to charge lifepo4 battery cell and made up with an input voltage of 43 v to 110 v. experimental results on a 160 ah lifepo4 battery for some state of charge shows that the maximum battery voltage has been limited at 3.77 to 3.78 v, and the maximum charging current could reach up to 10.64 a. this result shows that the maximum battery voltage is well regulated and the lifepo4 battery charger can keep the lifepo4 battery voltage according to the maximum reference voltage. this result shows that the charger can regulate the maximum battery voltage. it can be concluded that the charger can be used to charge a lifepo4 battery cell and balance the battery pack with a number of cells from 15 to 30 cells depending on the input voltage. figure 8. charging process with initial voltage of 3.36 v figure 9. charging process with different initial voltage 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 0 1 2 3 4 5 6 7 0 5 10 15 20 25 30 35 40 45 50 v o lt a g e ( v ) cu rr e n t (a ) time (h) icharge (a) vbat (v) 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 0 5 10 15 20 25 30 35 40 45 50 v o lt a g e ( v ) time (h) vbat1 vbat2 vbat3 amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 87 acknowledgement the authors would like to thank all members of the electric vehicle research group, research centre for electrical power and mechatronics which have already supported the battery management system research and development. references [1] a. al-haj hussein and i. batarseh, “a review of charging algorithms for nickel and lithium battery chargers,” ieee transactions on vehicular technology, vol. 60, no. 3, pp. 830– 838, 2011. [2] l. r. dung, c. e. chen, and h. f. yuan, “a robust, intelligent cc-cv fast charger for aging lithium batteries,” in proceeding of 2016 ieee 25th international symposium on industrial electronics (isie), 2016, pp. 268–273. [3] amin, k. ismail, a. nugroho, and s. kaleg, “passive balancing battery management system using mosfet internal resistance as balancing resistor,” in proceeding of 2017 international conference on sustainable energy engineering and application (icseea), 2017, pp. 151–155. [4] m. brandl, h. gall, m. wenger, v. lorentz, m. giegerich, f. baronti, g. fantechi, l. fanucci, r. roncella, r. saletti, s. saponara, a. thaler, m. cifrain, and w. prochazka, “batteries and battery management systems for electric vehicles,” in proceeding of 2012 design, automation & test in europe conference & exhibition (date), 2012, pp. 971–976.. [5] m. n. ramadan, b. a. pramana, s. a. widayat, l. k. amifia, a. cahyadi, and o. wahyunggoro, “comparative study between internal ohmic resistance and capacity for battery state of health estimation,” journal of mechatronics, electrical power, and vehicular technology, vol. 6, no. 2, p. 113, dec. 2015. [6] m. daowd, m. antoine, n. omar, p. lataire, p. van den bossche, and j. van mierlo, “battery management systembalancing modularization based on a single switched capacitor and bi-directional dc/dc converter with the auxiliary battery,” energies, vol. 7, no. 5, pp. 2897–2937, 2014. [7] t. a. stuart and w. zhu, “fast equalization for large lithium ion batteries,” ieee aerospace and electronic systems magazine, vol. 24, no. 7, pp. 27–31, july 2009. [8] t. a. stuart and w. zhu, “modularized battery management for large lithium ion cells,” journal of power sources, vol. 196, no. 1, pp. 458–464, 2011. [9] j.-c. lin, “development of a two-staged balancing scheme for charging lithium iron cells in series,” iet electr. syst. transp., vol. 6, no. 3, pp. 145–152, 2016. [10] j. c. m. lin, “development of a new battery management system with an independent balance module for electrical motorcycles,” energies, vol. 10, no. 9, 2017. [11] w. shen, t. t. vo, and a. kapoor, “charging algorithms of lithium-ion batteries: an overview,” in proceeding of 2012 7th ieee conference on industrial electronics and applications (iciea), 2012, pp. 1567–1572. [12] b. tar and a. fayed, “an overview of the fundamentals of battery chargers,” in proceeding of 2016 ieee 59th international midwest symposium on circuits and systems (mwscas), october 2017, pp. 16–19. [13] c.-h. lin, c.-l. chen, y.-h. lee, s.-j. wang, c.-y. hsieh, h.w. huang, and k.-h. chen, “fast charging technique for li-ion battery charger,” in proceeding of 2008 15th ieee international conference on electronics, circuits and systems, 2008, pp. 618–621. [14] a. kuperman, u. levy, j. goren, a. zafranski, and a. savernin, “high power li-ion battery charger for electric vehicle,” in proceeding of 2011 7th international conference-workshop compatibility and power electronics (cpe), june 2011, pp. 342–347. [15] s. o. yong and n. a. rahim, “development of on-off duty cycle control with zero computational algorithm for cc-cv li ion battery charger,” in proceeding of 2013 ieee conference on clean energy and technology (ceat), november 2013, pp. 422–426. [16] c.-c. hua, h.-r. chen, and y.-h. fang, “inductive power transmission technology for li-ion battery charger,” in proceeding of 2013 ieee 10th international conference on power electronics and drive systems (peds), 2013, pp. 788– 792. [17] k. park, y. choi, s. choi, and r. kim, “design consideration of cc-cv controller of llc resonant converter for li-ion battery charger,” in proceeding of 2015 ieee 2nd international future energy electronics conference (ifeec), 2015, pp. 1–6. [18] r. kushwaha and b. singh, “an ev battery charger based on pfc sheppard taylor converter,” in proceeding of 2016 national power systems conference (npsc), february 2017, pp. 1–6. [19] vicor corporation, “design guide & applications manual for maxi, mini, micro family dc-dc converter and accessory modules,” 2014. [20] vicor corporation, “constant current control for dc-dc converters,” 2010. [21] vicor corporation, “72v micro family,” 2017. https://doi.org/10.1109/tvt.2011.2106527 https://doi.org/10.1109/tvt.2011.2106527 https://doi.org/10.1109/tvt.2011.2106527 https://doi.org/10.1109/tvt.2011.2106527 https://doi.org/10.1109/isie.2016.7744901 https://doi.org/10.1109/isie.2016.7744901 https://doi.org/10.1109/isie.2016.7744901 https://doi.org/10.1109/isie.2016.7744901 https://doi.org/10.1109/icseea.2017.8267701 https://doi.org/10.1109/icseea.2017.8267701 https://doi.org/10.1109/icseea.2017.8267701 https://doi.org/10.1109/icseea.2017.8267701 https://doi.org/10.1109/icseea.2017.8267701 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.1109/date.2012.6176637 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.14203/j.mev.2015.v6.113-122 https://doi.org/10.3390/en7052897 https://doi.org/10.3390/en7052897 https://doi.org/10.3390/en7052897 https://doi.org/10.3390/en7052897 https://doi.org/10.3390/en7052897 https://doi.org/10.1109/maes.2009.5208557 https://doi.org/10.1109/maes.2009.5208557 https://doi.org/10.1109/maes.2009.5208557 https://doi.org/10.1016/j.jpowsour.2010.04.055 https://doi.org/10.1016/j.jpowsour.2010.04.055 https://doi.org/10.1016/j.jpowsour.2010.04.055 https://doi.org/10.1049/iet-est.2014.0047 https://doi.org/10.1049/iet-est.2014.0047 https://doi.org/10.1049/iet-est.2014.0047 https://doi.org/10.3390/en10091289 https://doi.org/10.3390/en10091289 https://doi.org/10.3390/en10091289 https://doi.org/10.1109/iciea.2012.6360973 https://doi.org/10.1109/iciea.2012.6360973 https://doi.org/10.1109/iciea.2012.6360973 https://doi.org/10.1109/iciea.2012.6360973 https://doi.org/10.1109/mwscas.2016.7870048 https://doi.org/10.1109/mwscas.2016.7870048 https://doi.org/10.1109/mwscas.2016.7870048 https://doi.org/10.1109/mwscas.2016.7870048 https://doi.org/10.1109/icecs.2008.4674929 https://doi.org/10.1109/icecs.2008.4674929 https://doi.org/10.1109/icecs.2008.4674929 https://doi.org/10.1109/icecs.2008.4674929 https://doi.org/10.1109/icecs.2008.4674929 https://doi.org/10.1109/cpe.2011.5942258 https://doi.org/10.1109/cpe.2011.5942258 https://doi.org/10.1109/cpe.2011.5942258 https://doi.org/10.1109/cpe.2011.5942258 https://doi.org/10.1109/cpe.2011.5942258 https://doi.org/10.1109/ceat.2013.6775668 https://doi.org/10.1109/ceat.2013.6775668 https://doi.org/10.1109/ceat.2013.6775668 https://doi.org/10.1109/ceat.2013.6775668 https://doi.org/10.1109/ceat.2013.6775668 https://doi.org/10.1109/peds.2013.6527124 https://doi.org/10.1109/peds.2013.6527124 https://doi.org/10.1109/peds.2013.6527124 https://doi.org/10.1109/peds.2013.6527124 https://doi.org/10.1109/peds.2013.6527124 https://doi.org/10.1109/ifeec.2015.7361597 https://doi.org/10.1109/ifeec.2015.7361597 https://doi.org/10.1109/ifeec.2015.7361597 https://doi.org/10.1109/ifeec.2015.7361597 https://doi.org/10.1109/npsc.2016.7858944 https://doi.org/10.1109/npsc.2016.7858944 https://doi.org/10.1109/npsc.2016.7858944 https://doi.org/10.1109/npsc.2016.7858944 http://www.vicorpower.com/documents/applications_manual/fas_trak_apps_manual.pdf http://www.vicorpower.com/documents/applications_manual/fas_trak_apps_manual.pdf http://www.vicorpower.com/documents/applications_manual/fas_trak_apps_manual.pdf http://www.vicorpower.com/documents/application_notes/an_constantcurrent.pdf http://www.vicorpower.com/documents/application_notes/an_constantcurrent.pdf http://cdn.vicorpower.com/documents/datasheets/ds_72vin-micro-family.pdf amin et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 81–88 88 this page is intentionally left blank microsoft word vol.01_no.2 issn 2087-3379 journal of mechatronics, electrical power and vehicular technology volume 01 nomor 2, 2010 penanggung jawab kepala pusat penelitian tenaga listrik dan mekatronik lipi ketua dewan editor dr.eng. estiko rijanto (mechatronics and control systems) editor pelaksana ghalya pikra, m.t. (mechanical engineering) naili huda, m.eng.sc. (industrial engineering) noviadi arief rachman, m.t. (power engineering) tinton dwi atmaja, m.t. (informatics, electrical engineering) editor ahli dr.eng. budi prawara (material engineering) dr.-ing. moch ichwan (vehicular technology) pudji irasari, m.sc.rer.nat. (electrical power) mitra bestari dr. yuliadi erdani (informatics engineering; politeknik manufaktur) dr. arko djajadi (mechatronics; swiss german university) sekretariat henny sudibyo, m.t. (sekretariat) roni permana saputra, s.t. (sekretariat) benua grahana sontani, a.md. (web admin) desain grafis m. redho kurnia, s.sn. (desain) jurnal ini tebit 2 (dua) kali dalam setahun journal of mechatronics, electrical power and vehicular technology adalah jurnal ilmiah yang diterbitkan oleh pusat penelitian tenaga listrik dan mekatronik lembaga ilmu pengetahuan indonesia (lipi). jurnal ini memuat karya ilmiah yg berupa tulisan hasil penelitian, pengembangan dan penerapan dalam bidang ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya. alamat redaksi sekretariat jurnal pusat penelitian tenaga listrik dan mekatronik lipi komp lipi jl. sangkuriang, gd. 20, lt. 2, ruang 229 bandung, jawa barat, 40135 telp: 022-2503055/2504770 fax: 022-2504773 e-mail: hennysudibyo@yahoo.com website: www.mevjournal.com www.telimek.lipi.go.id issn 2087-3379 i journal of mechatronics, electrical power and vehicular technology volume 01 nomor 2, 2010 kata pengantar dewan editor puji dan syukur kami panjatkan kepada tuhan yang maha esa, atas berkat dan karunia-nya kami dapat mempublikasikan journal of mechatronics, electrical power, and vehicular technology (jmev) volume 1 no 2 tahun 2010 ini. atas nama dewan editor kami mengucapkan terimakasih atas kerjasama dan kontribusi berbagai pihak yang telah membantu terbitnya jurnal ini. berdasarkan survei yang pernah kami lakukan, pada saat ini di indonesia telah banyak jurnal ilmiah dipublikasikan. namun belum ada jurnal yang secara spesifik memuat bidang keilmuan dan teknologi terkait dengan mekatronik, tenaga listrik, dan teknologi kendaraan. oleh karena itu, hadirnya jurnal ini diharapkan dapat menjadi media publikasi bagi para penggiat iptek dan industri terkait dengan mekatronik, tenaga listrik dan teknologi kendaraan. pada jmev edisi vol.1 no.2 tahun 2010 ini dimuat lima makalah yang telah melalui seleksi penilaian berjenjang oleh editor pelaksana, editor ahli dan mitra bestari sesuai dengan prosedur standar operasi yang ada. edisi ini memuat satu makalah tentang sistem kontrol traksi mobil elektrik, satu makalah tentang kebijakan konversi bbm ke bbg untuk kendaraan di jawa barat, satu makalah tentang material untuk catalytic converter, satu makalah tentang aplikasi kendali komputer jarak jauh, dan satu makalah tentang kendali sekuen untuk sambungan jala-jala listrik menggunakan cycloconverter. kami mengucapkan selamat membaca dan semoga publikasi ini turut menjadi sumbangsih bagi kemajuan ilmu pengetahuan dan teknologi pada umumnya, dan kemajuan bangsa pada khususnya. bandung, 21 desember 2010 dewan editor issn 2087-3379 ii journal of mechatronics, electrical power and vehicular technology volume 01 nomor 2, 2010 daftar isi pengembangan sistem kontrol traksi mobil elektrik berbasis rekonstruksi keadaan kecepatan model roda pratikto, yul yunazwin nazaruddin, edi leksono, zainal abidin 35-42 pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat vita susanti, agus hartanto, ridwan a.s., hendri m.s., estiko r., a. hapid 43-52 modification of surface roughness and area of fecral substrate for catalytic converter using ultrasonic treatment y. putrasari, p. untoro, s. hasan, n. huda, d. sebayang 53-60 rancang bangun aplikasi tele-kendali komputer via jaringan pstn dengan modul dtmf dan mikrokontroller attiny2313 yuliadi erdani, hendy rudiansyah 61-68 rancang bangun kendali sekuen untuk sambungan jala-jala listrik menggunakan cycloconverter yuliadi erdani, aris eko setiyawan, maulana aria pratama 69-74 microsoft word vol02_no1_v3 issn 2087-3379 (cetak) issn 2088-6985 (online) journal of mechatronics, electrical power and vehicular technology volume 02, nomor 1, 2011 penanggung jawab kepala pusat penelitian tenaga listrik dan mekatronik lipi ketua dewan editor dr.eng. estiko rijanto (mechatronics and control systems) editor pelaksana ghalya pikra, m.t. (mechanical engineering) naili huda, m.eng.sc. (industrial engineering) noviadi arief rachman, m.t. (power engineering) tinton dwi atmaja, m.t. (informatics, electrical engineering) editor ahli dr.eng. budi prawara (material engineering) dr.-ing. moch ichwan (vehicular technology) pudji irasari, m.sc.rer.nat. (electrical engineering/electric machines) mitra bestari dr. ahmad agus setiawan (renewable energy systems; ugm) ir. arko djajadi, ph.d. (mechatronics; swiss german university) dr. yuliadi erdani (informatics engineering; politeknik manufaktur) sekretariat dadan ridwan saleh, m.t. (web admin) merry indahsari devi, s.t. (sekretariat) vita susanti, s.kom. (sekretariat) desain grafis m. redho kurnia, s.sn. (desain) jurnal ini tebit 2 (dua) kali dalam setahun journal of mechatronics, electrical power and vehicular technology adalah jurnal ilmiah yang diterbitkan oleh pusat penelitian tenaga listrik dan mekatronik lembaga ilmu pengetahuan indonesia (lipi). jurnal ini memuat karya ilmiah yang berupa tulisan hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi, dan aplikasi perekayasaannya. alamat redaksi sekretariat jurnal pusat penelitian tenaga listrik dan mekatronik lipi komp lipi jl. sangkuriang, gedung 20, lantai 2, ruang 209 bandung, jawa barat, 40135 indonesia telp: 022-2503055/2504770 fax: 022-2504773 e-mail: sekretariat@mevjournal.com www.telimek.lipi.go.id/jurnal-jmev.htm www.mevjournal.com issn 2087-3379 (cetak) issn 2087-3379 (online) i journal of mechatronics, electrical power and vehicular technology volume 02, nomor 1, 2011 kata pengantar dewan editor puji dan syukur kami panjatkan kepada tuhan yang maha esa, atas berkat dan karunia-nya kami dapat mempublikasikan journal of mechatronics, electrical power, and vehicular technology (jmev) volume 2 no 1 tahun 2011 ini. atas nama dewan editor kami mengucapkan terimakasih atas kerjasama dan kontribusi berbagai pihak yang telah membantu terbitnya jurnal ini. berdasarkan survei yang pernah kami lakukan, pada saat ini di indonesia telah banyak jurnal ilmiah dipublikasikan. namun belum ada jurnal yang secara spesifik memuat bidang keilmuan dan teknologi terkait dengan mekatronik, tenaga listrik, dan teknologi kendaraan. oleh karena itu, hadirnya jurnal ini diharapkan dapat menjadi media publikasi bagi para penggiat iptek dan industri terkait dengan mekatronik, tenaga listrik dan teknologi kendaraan. pada jmev volume 2 nomor 1 tahun 2011 ini dimuat enam makalah yang telah melalui seleksi penilaian berjenjang oleh editor pelaksana, editor ahli dan mitra bestari sesuai dengan prosedur standar operasi yang ada. edisi ini memuat makalah-makalah tentang: pembangkit listrik tenaga angin, biomasa sawit, visual servo, pengarah panel ke matahari untuk csp (concentrated solar panel), pengendalian cnc router, dan pengujian vibrasi benda putar. kami mengucapkan selamat membaca dan semoga publikasi ini turut menjadi sumbangsih bagi kemajuan ilmu pengetahuan dan teknologi pada khususnya, dan kemajuan bangsa pada umumnya. bandung, 30 juni 2011 dewan editor issn 2087-3379 (cetak) issn 2088-6985 (online) ii journal of mechatronics, electrical power and vehicular technology volume 02, nomor 1, 2011 daftar isi experiment and analysis of car alternator for wind turbine application pudji irasari 1-10 kajian teknis & keekonomian pembangkit listrik tenaga biomasa sawit; kasus: di pabrik kelapa sawit pinang tinggi, sei bahar, jambi irhan febijanto 11-22 penggunaan extended kalman filter sebagai estimator sikap pada sistem kendali servo visual robot noor cholis basjaruddin 23-30 rancang bangun sistem kontrol mekanisme pelacakan matahari beserta fasilitas telekontrol hemat energi midriem mirdanies, rizqi andry a, hendri maja saputra, aditya sukma nugraha, estiko rijanto, adi santoso 31-40 desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine roni permana saputra, anwar muqorrobin, arif santoso, teguh pudji purwanto 41-50 monitoring vibration of a model of rotating machine arko djajadi, arsi azavi, rusman rusyadi, erikson sinaga 51-56 mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 06, 2015 authors index aam muharam, "estimating power needed to fuel electric paratransits in bandung," 06(2): 123-128 abdul hapid, "economic valuation of hypothetical paratransit retrofitting," 06(1): 49-56 adha cahyadi, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 adha cahyadi, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 ahmad ataka, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 ali sadiyoko, "obstacle avoidance method for a group of humanoids inspired by social force model," 06(2): 67-74 ardhimas wimbo, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 ari darmawan pasek, "geometry analysis and effect of turbulence model on the radial rotor turboexpander design for small organic rankine cycle system," 06(1): 39-48 bambang riyanto trilaksono, "nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung," 06(1): 19-30 bambang riyanto trilaksono, "obstacle avoidance method for a group of humanoids inspired by social force model," 06(2): 67-74 bambang wahono, "prediction model of battery state of charge and control parameter optimization for electric vehicle," 06(1): 31-38 bhisma adji pramana, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 edwin romeroso arboleda, "development of a low-cost electronic wheelchair with obstacle avoidance feature," 06(2): 89-96 endra joelianto, "modeling, identification, estimation, and simulation of urban traffic flow in jakarta and bandung," 06(1): 57-66 estiko rijanto, "algorithm of 32-bit data transmission among microcontrollers through an 8-bit port," 06(2): 75-82 estiko rijanto, "design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model," 06(2): 105-112 fadjar rahino triputra, "nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung," 06(1): 19-30 gesang nugroho, "development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping," 06(2): 83-88 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii giovanni alarkon tapang, "development of a microcontroller-based wireless accelerometer for kinematic analysis," 06(1): 1-8 harutoshi ogai, "prediction model of battery state of charge and control parameter optimization for electric vehicle," 06(1): 31-38 hatyo hadsanggeni, "development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping," 06(2): 83-88 hendri maja saputra, " algorithm of 32-bit data transmission among microcontrollers through an 8-bit port," 06(2): 75-82 herman y. sutarto, "modeling, identification, estimation, and simulation of urban traffic flow in jakarta and bandung," 06(1): 57-66 hilman syaeful alam, "study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system," 06(2): 97-104 hilton tnunay, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 imam djunaedi, "study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system," 06(2): 97-104 iswanto, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 jan pierre potato pizarro, "development of a microcontroller-based wireless accelerometer for kinematic analysis," 06(1): 1-8 john sasso, "study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system," 06(2): 97-104 kathleen felix idica, "development of a low-cost electronic wheelchair with obstacle avoidance feature," 06(2): 89-96 kim peter hassall, "economic valuation of hypothetical paratransit retrofitting," 06(1): 49-56 kim peter hassall, "estimating power needed to fuel electric paratransits in bandung," 06(2): 123-128 kristian ismail, "prediction model of battery state of charge and control parameter optimization for electric vehicle," 06(1): 31-38 kristian ismail, "estimating power needed to fuel electric paratransits in bandung," 06(2): 123-128 kusprasapta mutijarsa, "obstacle avoidance method for a group of humanoids inspired by social force model," 06(2): 67-74 lora khaula amifia, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 maria clarissa alvarez carasco, "development of a microcontroller-based wireless accelerometer for kinematic analysis," 06(1): 1-8 mary christine tumambing alegre, "development of a low-cost electronic wheelchair with obstacle avoidance feature," 06(2): 89-96 maulana arifin, "geometry analysis and effect of turbulence model on the radial rotor turboexpander design for small organic rankine cycle system," 06(1): 39-48 midriem mirdanies, " algorithm of 32-bit data transmission among microcontrollers through an 8-bit port," 06(2): 75-82 mohamad dahsyat, "nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung," 06(1): 19-30 m. nisvo ramadan, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix m. qodar abdurrohman, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 naili huda, "economic valuation of hypothetical paratransit retrofitting," 06(1): 49-56 naili huda, "estimating power needed to fuel electric paratransits in bandung," 06(2): 123-128 oyas wahyunggoro, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 rasli bin abd ghani, "design and implementation of controller for boost dc-dc converter using pilpf based on small signal model," 06(2): 105-112 reka inovan, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 rianto adhy sasongko, "nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung," 06(1): 19-30 sigit agung widayat, "comparative study between internal ohmic resistance and capacity for battery state of health estimation," 06(2): 113-122 slamet kasbi, "design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model," 06(2): 105-112 sunarto kaleg, "economic valuation of hypothetical paratransit retrofitting," 06(1): 49-56 tedy setya nugraha, "development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping," 06(2): 83-88 trio adiono, "nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung," 06(1): 19-30 widyawardana adiprawita, "obstacle avoidance method for a group of humanoids inspired by social force model," 06(2): 67-74 yoshio yamamoto, "a modified gain scheduling controller by considering the sparseness property of uav quadrotors," 06(1): 9-18 zahari taha, "development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping," 06(2): 83-88 zaidan eddy, "geometry analysis and effect of turbulence model on the radial rotor turbo-expander design for small organic rankine cycle system," 06(1): 39-48 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x journal of mechatronics, electrical power, and vehicular technology volume 06, 2015 affiliation index agency for the assessment and application of technology (bppt), tangerang, indonesia 19 department of computer and electronics engineering, college of engineering and information technology, cavite state university, philippines 89 department of electrical engineering and information technology, gadjah mada university, yogyakarta, indonesia 9, 113 department of infrastructure engineering, melbourne school of engineering, australia 49,123 department of mechanical and industrial engineering, faculty of engineering, universitas gadjah mada, indonesia 83 department of precision engineering, school of engineering, tokai university, japan 9 faculty of mechanical and aerospace engineering, institut teknologi bandung, indonesia 19 graduate school of information, production and systems, waseda university 2-7 hibikino, wakamatsu-ku, kitakyushu, fukuoka, japan 31 innovative manufacturing, machatronics and spots lab (imams), universiti malaysia pahang, malaysia 83 instrumentation and control research group, institut teknologi bandung, indonesia 57 malaysia-japan international inst. of tech. (mjiit), universiti teknologi malaysia (utm) kuala lumpur, malaysia 105 mechatronics engineering department, universitas katolik parahyangan, indonesia 67 ministry of energy and mineral resources (kesdm), research and development agency (p3tkebtke), indonesia 105 research centre for electrical power and mechatronics,indonesian institute of sciences (lipi), indonesia 31, 39, 49, 75, 105, 123 research center for physics, indonesian institute of sciences, indonesia 97 rrt sigma engineering, one huntington quadrangle 3s-01, melville, new york, usa 97 school of electrical engineering & informatics, institut teknologi bandung, indonesia 19, 67 systems research group, universiteit gent technologie, belgium 57 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi technical implementation unit for instrumentation development, indonesian institute of sciences, indonesia 97 thermodynamics laboratory, faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia 39 versatile instrumentation system for science education and research national institute of physics, university of the philippines diliman, philippines 1 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii journal of mechatronics, electrical power, and vehicular technology international peer reviewers prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu prof. dr. ir. suhono h supangkat, m.eng, cgeit. stei institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suhono@stei.itb.ac.id prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, faculty of engineering,universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia estiko.rijanto@ lipi.go.id prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia za@dynamic.pauir.itb.ac.id prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary patko@uni-obuda.hu prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia, depok, indonesia, dasumarsono@gmail.com dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia, depok, indonesia, pamitran@eng.ui.ac.id george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com ir. arko djajadi, ph.d. swiss german university edutown bsdcity – tangerang 15339, indonesia arko@sgu.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr. ahmad agus setiawan department of engineering physics, faculty of engineering, gadjah mada university, jl.grafika2, yogyakarta 55281, indonesia a.setiawan@ugm.ac.id dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id dr. endra pitowarno electronics engineering polytechnic institute of surabaya (eepis), kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia epit@eepis-its.edu dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung, jl. ganesha no. 10, bandung 40135 indonesia iman@lmbsp.ms.itb.ac.id mailto:patko@uni-obuda.hu javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/748') mailto:a.setiawan@ugm.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi.prawara@lipi.go.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id dr. si steve li electromechanical system development, general electric global research centre, 610 london square drive, clifton park, ny12065, united states si.li@ge.com dr. yuliadi erdani politeknik manufaktur bandung jalan kanayakan no. 21 dago, bandung – 40135, indonesia yul_erdani@polman-bandung.ac.id dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia yahmudiarto@yahoo.com dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia irhan.febijanto@gmail.com dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia rizqon66@gmail.com dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl. jl. jendral gatot subroto kav. 10 jakarta-indonesia trina.fizzanty@lipi.go.id dr. anna maria sri asih mechanical & industrial engineering department, gadjah mada university jl. grafika 2 yogyakarta 55281, indonesia amsriasih@ugm.ac.id dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia anindito@ub.ac.id ir. edi leksono, m.eng, ph.d. engineering physics, institut teknologi bandung jalan ganesha 10 bandung 40132, indonesia edi@tf.itb.ac.id dr. adha cahyadi department of electrical engineering, gadjah mada university, jl.grafika 2, yogyakarta 55281, indonesia masimam@jteti.gadjahmada.edu dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia moch019@lipi.go.id esa prakasa, ph.d research centre for informatics – lipi, komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia esa.prakasa@gmail.com dr. edi kurniawan, s.t., m.eng research centre for informatics – lipi, komp lipi jl sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia ekurniawan@live.com dr. arjon turnip technical management unit for instrumentation development lipi, komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia jujhin@gmail.com dr. wahyudi sutopo industrial engineering, universitas sebelas maret surakarta, jl. ir. sutami 36a, surakarta, 57126, indonesia wahyudisutopo@gmail.com pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jlsangkuriang, blg 20, 2ndfl, bandung 40135, indonesia pudji.irasari@lipi.go.id assoc. prof. john young school of engineering and it, the university of new south wales, australia j.young@adfa.edu.au dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales australia j.guivant@unsw.edu.au prof. josep m. rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain josep.maria.rossell@upc.edu prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, intitut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia, adisup@ee.its.ac.id dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, tdirgantara@ftmd.itb.ac.id mailto:pudji.irasari@lipi.go.id javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') mailto:j.young@adfa.edu.au javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') mailto:j.guivant@unsw.edu.au javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/746') mailto:josep.rubio@upc.edus javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') mailto:adisup@ee.its.ac.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv publication ethics and malpractice statement mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics lipi). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi author guideline writing should be submitted according to these following restrictions: 1. manuscript should be written in english and be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. paper should be in prepared in a4 paper (21cm x 29.7cm) using 2.5 cm for inside margin and 2 cm for top, bottom, and outside margin. 3. title, abstract, and keywords should be written in english a. title should be less than 15 words, title case, small caps, centered, bold, font type times new roman (tnr), font size 16, and single spaced. b. abstract contains neither pictures nor tables, justified, in 11 tnr, single spaced, and should not exceed 250 words. c. keywords contain three to five words/phrases separated with coma and should be justified, 10 tnr and single spaced. 4. manuscript body should be: a. the main text of the writing should be in two columns with 1 cm colom spacing, justified, 11 tnr, first line indent 5 mm, and single spaced. b. consist of: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) e. heading 5 cannot be accepted in the manuscript 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 9 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 8. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 9. detailed referencing manual can be seen in the author guideline that can be downloaded in journal website. the board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first. editorial board http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal providing authoritative source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, tubine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev’s vision is to become international platform with high scientific contribution for global community. mev’s mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi) and managed to be issued twice in every volume. the first issue should be in the mid of the year and the second issue is in the end of the year. issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: www.mevjournal.com mev allows reuse and remixing of its content, in accordance with a cc license of cc by-nc-sa. article management & plagiarism check every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. accepted article to be published in mev journal will be proofed using grammarly® checker software. plagiarism screening will be conducted by mev editorial board using crosscheck™ powered by ithenticate® and grammarly® plagiarism checker. article processing charges every article submitted to mev journal will not have any article processing charges. this includes peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. indexing & abstracting indexed in ebscohost, google scholar, directory of open access journal (doaj), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), mendeley, citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi) by 15 april 2015. accreditation number: 633/au/p2mi-lipi/03/2015 valid thru: 15 april 2020. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia telp : +62-022-2503055 (ext. 215) telp : +62-022-2504770 (ext. 203) fax : +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, 26600 pekan, pahang, malaysia rosli@ump.edu.my prof. tapan kumar saha electrical engineering, the university of queensland, st. lucia, qld-4072, australia tksaha@ieee.org george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states ganwar@integratedmotions.com prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, jl. grafika no. 2, yogyakarta, 55281, indonesia jamasri_tmugm@yahoo.com prof. josep m. rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain josep.maria.rossell@upc.edu assoc. prof. john young school of engineering and it, the university of new south wales, australia j.young@adfa.edu.au prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states taufik@calpoly.edu dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales australia j.guivant@unsw.edu.au prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta, jl. ir. sutami 36 a, surakarta, 57126, indonesia nizam_kh@ieee.org prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan tagawa@cc.tuat.ac.jp prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia briyanto@lskk.ee.itb.ac.id prof. dr. adi soeprijanto department of electrical engineering, intitut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia adisup@ee.its.ac.id riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810indonesia riza.muhida@stkipsurya.ac.id dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, tdirgantara@ftmd.itb.ac.id prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia, depok, indonesia, dasumarsono@gmail.com dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia, depok, indonesia, pamitran@eng.ui.ac.id dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany larissa.lorenz@bauhausluftfahrt.net dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, ndonesia budi.prawara@lipi.go.id advisory editor dr. endra joelianto engineering physics, institutteknologi bandung jl. ganesha no. 10, bandung 40135 indonesia ejoel@tf.itb.ac.id mailto:rosli@ump.edu.my javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/746') mailto:josep.rubio@upc.edus javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') mailto:j.young@adfa.edu.au javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') mailto:j.guivant@unsw.edu.au mailto:briyanto@lskk.ee.itb.ac.id javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') mailto:adisup@ee.its.ac.id javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/748') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 deputy editors aam muharam, m.t. electrical engineering aam.muharam@lipi.go.id tinton d atmaja, m.t. informatic systems and electrical engineering tinton_dwi@yahoo.com managing editors, central office ghalya pikra, m.t. mechanical engineering ghalya30@gmail.com merry i devi, s.t. industrial engineering merry_devi@yahoo.com managing editor, asia pacific region yanuandri putrasari, m.eng. mechanical engineering yanuandri.putrasari@lipi.go.id managing editor, europe region naili huda, m.eng.sc. industrial engineering vedderforeva@yahoo.com editors aditya sukma nugraha, m.t. mechanical engineering aditngrh@gmail.com agus risdiyanto, m.t. electrical engineering riesdian@gmail.com amin, m.t. electrical engineering amin_hwi@yahoo.co.id arief a firdaus, s.i.kom. communication science rif212@yahoo.com arini wresta, m.eng. chemical engineering awresta@gmail.com bambang wahono, m.eng. mechanical engineering bambangwahono80@yahoo.co.id dian andriani, m.eng. bioenergy engineering dea1401@yahoo.com hendri m saputra, m.t. robotics and mechatronics hendri_maja@yahoo.co.id kadek heri sanjaya, ph.d ergonomics, biomechanics, physiology kade001@lipi.go.id maulana arifin, m.t. mechanical engineering maul004@lipi.go.id midriem mirdanies, m.t. computer engineering midr001@lipi.go.id muhammad kasim, m.renen electrical engineering kasime99uh@yahoo.co.id nur rohmah, m.t. chemical engineering rohmah.nur@gmail.com rakhmad indra pramana, m.t. mechanical and material engineering rakhmad.indra@yahoo.com vita susanti, s.kom computer science vitasusanti@gmail.com yayat ruhiyat, a.md. electrical engineering yayatruhi@gmail.com web admin dadan r saleh, m.t. informatics engineering dadan.rs@gmail.com secretariat andri j purwanto, s.t. mechanical engineering ajp_jun@yahoo.com henny sudibyo, m.eng industrial engineering hennysudibyo@yahoo.com graphic designer yukhi mustaqim kusuma sya bana, s.sn. graphic design yuqmail@yahoo.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 © 2015 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by ebscohost, google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib and cite factor. its digital object identifier (doi) prefix is 10.14203. in this issue, eight papers are published with the total number of paper pages of 62 pages. the selected papers have passed high level of reviews and revisions based on the standard operating procedure of the journal. the authors come from indonesia, malaysia, philippines, australia, and usa. four topics of the papers are related to mechatronics which address obstacle avoidance method for a group of humanoids inspired by social force model, algorithm of 32-bit data transmission among microcontrollers through an 8-bit port, development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping, and development of a low-cost electronic wheelchair with obstacle avoidance feature. two topics are related to electrical power concerning study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system, and design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model. in the scope of vehicular technology and related topics there are two papers presented those are comparative study between internal ohmic resistance and capacity for battery state of health estimation, and estimating power needed to fuel electric paratransits in bandung. since the first issue, our journal provides discretion in financial term by waiving the article processing charge. we are planning to improve the quality by registering the journal to other international academic citation index. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2015 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 ii list of contents obstacle avoidance method for a group of humanoids inspired by social force model ali sadiyoko, bambang riyanto trilaksono, kusprasapta mutijarsa, widyawardana adiprawita 67-74 algorithm of 32-bit data transmission among microcontrollers through an 8-bit port midriem mirdanies, hendri maja saputra, estiko rijanto 75-82 development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping gesang nugroho, zahari taha, tedy setya nugraha, hatyo hadsanggeni 83-88 development of a low-cost electronic wheelchair with obstacle avoidance feature edwin romeroso arboleda, mary christine tumambing alegre, kathleen felix idica 89-96 study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system hilman syaeful alam, john sasso, imam djunaedi 97-104 design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model slamet kasbi, estiko rijanto, rasli bin abd ghani 105-112 comparative study between internal ohmic resistance and capacity for battery state of health estimation m. nisvo ramadan, bhisma adji pramana, sigit agung widayat, lora khaula amifia, adha cahyadi, oyas wahyunggoro 113-122 estimating power needed to fuel electric paratransits in bandung naili huda, kim peter hassall, aam muharam, kristian ismail 123-128 further articles can be found at www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 06, issue 2, december 2015 abstracts sheet e-issn: 2088-6985 date of issues: 30 december 2015 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. ali sadiyokoa,b, bambang riyanto trilaksonob, kusprasapta mutijarsab, widyawardana adiprawitab (amechatronics engineering department, universitas katolik parahyangan, bandung, indonesia; bschool of electrical engineering & informatics, institut teknologi bandung, indonesia) obstacle avoidance method for a group of humanoids inspired by social force model journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 67-74, 11 ill, 0 tab, 11 ref. this paper presents a new formulation for obstacle and collision behavior on a group of humanoid robots that adopts walking behavior of pedestrian crowd. a pedestrian receives position information from the other pedestrians, calculate his movement and then continuing his objective. this capability is defined as sociodynamic capability of a pedestrian. pedestrian’s walking behavior in a crowd is an example of a sociodynamics system and known as social force model (sfm). this research is trying to implement the avoidance terms in sfm into robot’s behavior. the aim of the integration of sfm into robot’s behavior is to increase robot’s ability to maintain its safety by avoiding the obstacles and collision with the other robots. the attractive feature of the proposed algorithm is the fact that the behavior of the humanoids will imitate the human’s behavior while avoiding the obstacle. the proposed algorithm combines formation control using consensus algorithm (ca) with collision and obstacle avoidance technique using sfm. simulation and experiment results show the effectiveness of the proposed algorithm. (author) keywords: humanoid robots; formation control; obstacle avoidance; social force model; consensus algorithm. midriem mirdanies, hendri maja saputra, estiko rijanto (research centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia) algorithm of 32-bit data transmission among microcontrollers through an 8-bit port journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 75-82, 19 ill, 4 tab, 13 ref. this paper proposes an algorithm for 32-bit data transmission among microcontrollers through one 8-bit port. this method was motivated by a need to overcome limitations of microcontroller i/o as well as to fulfill the requirement of data transmission which is more than 10 bits. in this paper, the use of an 8-bit port has been optimized for 32-bit data transmission using unsigned long integer, long integer, and float types. thirty-two bit data is extracted into binary number, then sent through a series of 8-bit ports by transmitter microcontroller. at receiver microcontroller, the binary data received through 8-bit port is reconverted into 32 bits with the same data type. the algorithm has been implemented and tested using c language in atmega32a microcontroller. experiments have been done using two microcontrollers as well as four microcontrollers in the parallel, tree, and series connections. based on the experiments, it is known that the data transmitted can be accurately received without data loss. maximum transmission times among two microcontrollers for unsigned long integer, long integer, and float are 630 µs, 1,880 µs, and 7,830 µs, respectively. maximum transmission times using four microcontrollers in parallel connection are the same as those using two microcontrollers, while in series connection are 1,930 µs for unsigned long integer, 5,640 µs for long integer, and 23,540 µs for float. the maximum transmission times of tree connection is close to those of the parallel connection. these results prove that the algorithm works well. (author) keywords: transmission algorithm; 32-bit data; data transmission; 8-bit port; microcontroller; c language. gesang nugrohoa, zahari tahab, tedy setya nugrahaa, hatyo hadsanggenia (adepartment of mechanical and industrial engineering, faculty of engineering, gadjah mada university, yogyakarta, indonesia; binnovative manufacturing, machatronics and spots lab (imams), universiti malaysia pahang, pahang, malaysia) development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 83-88, 10 ill, 1 tab, 11 ref. the development of remote sensing technology offers the ability to perform real-time delivery of aerial video and images. a precise disaster map allows a disaster management to be done quickly and accurately. this paper discusses how a fixed wing uav can perform aerial monitoring and mapping of disaster area to produce a disaster map. this research was conducted using a flying wing, autopilot, digital camera, and data processing software. the research starts with determining the airframe and the avionic system then determine waypoints. the uav flies according to the given waypoints while taking video and photo. the video is transmitted to the ground control station (gcs) so that an operator in the ground can monitor the area condition in real time. after obtaining data, then it is processed to obtain a disaster map. the results of this research are: a fixed wing uav that can monitor disaster area and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv send real-time video and photos, a gcs equipped with image processing software, and a mosaic map. this uav used a flying wing that has 3 kg empty weight, 2.2 m wingspan, and can fly for 12-15 minutes. this uav was also used for a mission at parangtritis coast in the southern part of yogyakarta with flight altitude of 150 m, average speed of 15 m/s, and length of way point of around 5 km in around 6 minutes. a mosaic map with area of around 300 m x 1500 m was also obtained. interpretation of the mosaic led to some conclusions including: lack of evacuation routes, residential area which faces high risk of tsunami, and lack of green zone around the shore line. (author) keywords: uav; remote sensing; disaster monitoring; disaster area mapping; photo mosaic. edwin romeroso arboleda, mary christine tumambing alegre, kathleen felix idica (department of computer and electronics engineering, college of engineering and information technology, cavite state university indang, cavite, philippines) development of a low-cost electronic wheelchair with obstacle avoidance feature journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 89-96, 6 ill, 2 tab, 18 ref. a low-cost electronic wheelchair was designed and developed which can perform the similar functions and features as a commercially available wheelchair. it also provides obstacle avoidance capability as added value. the electronic wheelchair was realized by modification of a lightweight manual wheelchair. it uses two electric motors each of 320 w 24 v dc, 5-24 vdc 6 a hbridge drivers, and a 12 v 17 ah rechargeable lead acid battery. it equipped with switches, joystick, infrared sensors and ultrasonic sensors. a gizduino atmega328 microcontroller is used to read and interpret commands. user’s acceptance evaluation results show that the developed low-cost wheelchair is able to receive and interpret commands provided by the joystick, detect if a person is seated on it, navigate to avoid obstacles as well as to detect edge and stairs. technical evaluation result shows that on a flat surface it could move at the speed of around 39.9 m/min without load and 32 m/min with 80 kg load. at 10 degrees inclined surface, the maximum weight limit is 30 kg with the speed of 12 m/min. at 20 degrees inclined surface, the maximum weight limit is 10 kg with the speed of 3 m/min. regarding cost, it is just a fraction of a cost compared to the commercially available model. therefore, the developed wheelchair offers an option for potential users who cannot afford to buy the commercially available one. (author) keywords: electronic wheelchair; obstacle avoidance; edge detection; gizduino atmega328; microcontroller. hilman syaeful alama, john sassob, imam djunaedic (atechnical implementation unit for instrumentation development, indonesian institute of sciences, bandung, indonesia; brrt sigma engineering, melville, new york, usa; cresearch center for physics, indonesian institute of sciences, bandung, indonesia) study on performance improvement and economical aspect of gas turbine power plant using evaporative cooling system journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 97-104, 10 ill, 6 tab, 11 ref. the study is intended to improve the performance of gas turbine engines in order to meet both electrical power demand and peak load in the power plant. in this paper, evaporative cooling system had been applied to improve the performance of gas turbine in pesanggaran power plant in southern bali island, indonesia. moreover, the economic analysis was conducted to determine the capacity cost, operating cost and payback period due to the investment cost of the system. based on the evaluation results, the power improvement for the three gas turbine units (gt1, gt2 and gt3) are 2.09%, 1.38%, and 1.28%, respectively. these results were not very significant when compared to the previous studies as well as on the aspects of sfc (specific fuel consumption), heat rate and thermal efficiency. based on the evaluation of the economic aspects, the reduction of production costs due to the application of evaporative cooling system was not economical, because it could not compensate the investment cost of the system and it resulted a very long payback period. these unsatisfactory results could be caused by the high relative humidity. therefore, further studies are needed to investigate the other alternative technologies which are more suitable to the climate conditions in indonesia. (author) keywords: performance improvement; economic analysis; evaporative cooling; gas turbine; power plant. slamet kasbia,c, estiko rijantob, rasli bin abd ghania (ªmalaysiajapan international inst. of tech. (mjiit), universiti teknologi malaysia (utm) kuala lumpur, malaysia; bresearch centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia; cministry of energy and mineral resources (kesdm), research and development agency (p3tkebtke), jakarta, indonesia) design and implementation of controller for boost dc-dc converter using pi-lpf based on small signal model journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 105-112, 9 ill, 2 tab, 10 ref. boost dc-dc converters are used in many renewable energy sources including photovoltaic and fuel cell. they are also used in uninterrupted power supply, inverters, electric vehicles and robots. in this paper a boost converter was built and its controller was developed using proportional integral (pi) action for current loop and low pass filter (lpf) for voltage loop. the controller was derived analytically based on small signal model. experiment results show that the boost controller functions well in regulating the output voltage under a variation of load. during the start up without any load it can elevate input voltage from 119.6 v to output voltage of 241.6 v. the developed controller can regulate the output voltage smoothly under load variation from no load to sudden load of 352 w. when a large sudden load change happens from 0 w to 1,042 w the output voltage experiences small drop before it is recovered to 241.6 v. it can be concluded that the developed control system works well satisfying the design specification. (author) keywords: controller; boost dc-dc converter; pi; lpf; small signal. m. nisvo ramadan, bhisma adji pramana, sigit agung widayat, lora khaula amifia, adha cahyadi, oyas wahyunggoro (department of electrical engineering and information technology, gadjah mada university, yogyakarta, indonesia) comparative study between internal ohmic resistance and capacity for battery state of health estimation journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 113-122, 17 ill, 0 tab, 20 ref. in order to avoid battery failure, a battery management system (bms) is necessary. battery state of charge (soc) and state of health (soh) are part of information provided by a bms. this research analyzes methods to estimate soh based lithium polymer battery on change of its internal resistance and its capacity. recursive least square (rls) algorithm was used to estimate internal ohmic resistance while coloumb counting was used to predict the change in the battery capacity. for the estimation algorithm, the battery terminal voltage and current are set as the input variables. some tests including static capacity test, pulse test, pulse variation test and before charge-discharge test have been conducted to obtain the required data. after comparing the two methods, the obtained results show that soh estimation based on coloumb counting provides better accuracy than soh estimation journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v based on internal ohmic resistance. however, the soh estimation based on internal ohmic resistance is faster and more reliable for real application. (author) keywords: battery management system; state of health; lithium polymer; recursive least square; coulomb counting. naili hudaa, kim peter hassallb, aam muharama, kristian ismaila (aresearch centre for electrical power and mechatronics, indonesian institute of sciences, bandung, indonesia; bdepartment of infrastructure engineering, melbourne school of engineering, melbourne, australia) estimating power needed to fuel electric paratransits in bandung journal of mechatronics, electrical power, and vehicular technology, december 2015, vol. 6, no. 2, p. 123-128, 2 ill, 1 tab, 35 ref. this is the preliminary finding of a study elaborating the total energy consumption when paratransits in bandung are altered into electric and the scenario to fulfill it. therefore, there are lots to be done further concerning result of this initial research, of which will be discussed in another publication. in this paper calculation was done to find out the volume of power needed to fuel electric paratransits in bandung. steps carried out include computing total energy consumption for all paratransits, clustering stations from classified routes established by local department of transport, and estimating the electricity demand in every clustered station. data used for this study was acquired from badan pusat statistik kota bandung and pt pln dja apd jawa barat and banten. a total demand of 61.12 mwh per month will surface to charge the total of 5,521 paratransits from 38 available routes in 15 clustered stations under the assumptions that all paratransits only make 6 return travels per day, operate 30 days per month, and use batteries with 50% state of charge. (author) keywords: transportation; electric paratransit; in town; electricity demand; feasibility study. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi this page is left blank microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 13 analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari ghalya pikra, agus salim, tri admono, merry indahsari devi pusat penelitian tenaga listrik dan mekatronik lipi komp lipi bandung , jl. sangkuriang, gd. 20. lt. 2, bandung, jawa barat 40135, indonesia ghalyapikra@yahoo.com; agus.salim35@yahoo.com; januar35@yahoo.com; merry_devi@yahoo.com diterima: 19 agustus 2010; direvisi: 23 september 2010; disetujui: 30 september 2010; terbit online: 10 oktober 2010. abstrak analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari dimaksudkan untuk mengetahui nilai panas yang hilang selama dilakukan penyimpanan. pemilihan bahan isolasi, tebal isolasi, waktu penyimpanan dan fluida penyimpan panas mempengaruhi nilai rugi-rugi panas. penelitian diawali dengan menentukan dimensi dan bahan tangki beserta isolasinya, serta menentukan waktu penyimpanan panas di dalam tangki. fluida dan temperatur operasi ditentukan untuk mendapatkan spesifikasi fluida yang akan digunakan sebagai data analisis. analisis diawali dengan perhitungan kapasitas penyimpanan, dilanjutkan dengan pembuatan jala-jala termal untuk mendapatkan persamaan tahanan termal yang kemudian digunakan untuk menghitung rugi-rugi panas pada tangki. hasil perhitungan menunjukkan bahwa tangki penyimpan panas dengan diameter 0,4 m dan tinggi 0,45 m serta isolasi menggunakan ceramic fiber wool dengan tebal 0,1 m, maka nilai rugirugi panas yang dihasilkan adalah 63,43 w. kata kunci: pembangkit listrik tenaga matahari, tangki penyimpan panas, ceramic, rugi-rugi panas.  abstract analysis of heat loss on heat storage tank in solar power generation system is intended to determine the heat loss value during storage. selection of insulation material, insulation thickness, time of storage and heat storage fluid affects the heat losses. the research was initiated by determining the dimension of the tank and its insulation material, and determining the heat storage time in the tank. fluid and operating temperature is determined to get the fluid specification to be used as data analysis. the analysis begins with the calculation of storage capacities, followed by making of thermal nets to get the thermal resistance equation which is then used to calculate the heat loss in the tank. the result shows that the heat storage tank with 0.4 m diameter and 0.45 m height and uses ceramic fiber wool insulation with 0.1m thickness gives the value of heat loss of 63.43 w. keywords: solar power plants, heat storage tank, ceramic, heat loss. i. pendahuluan energi matahari merupakan sumber energi yang paling banyak di bumi. konversi energi matahari menjadi energi panas yang kemudian menghasilkan listrik adalah aplikasi energi matahari yang paling penting. wu, reddy dan rogers menyatakan bahwa energi yang berasal dari matahari perlu disimpan karena ketersediaan energi matahari tergantung pada waktu, kondisi cuaca, dan garis lintang, dimana permintaan listrik bervariasi tergantung waktu [1]. energi ini dapat disimpan sebagai energi termal atau listrik. penyimpanan energi termal merupakan teknologi yang penting untuk efisiensi energi. oleh karena itu, penyimpanan energi termal dianggap sebagai metode yang ekonomis [2]. tiga komponen utama pemanfaatan sistem energi termal matahari terkonsentrasi adalah collector energi matahari, sistem penyimpanan energi, dan steam generator yang digunakan untuk menggerakkan turbin untuk membangkitkan listrik. solar collector digunakan sebagai pengumpul panas dari matahari yang kemudian digunakan untuk memanaskan fluida didalam receiver atau absorber. sistem penyimpanan energi berfungsi untuk menciptakan efisiensi energi. steam generator disini adalah sebagai penghasil uap untuk menggerakkan turbin. pada sistem pembangkit listrik tenaga matahari terkonsentrasi, panas matahari dikumpulkan dalam pengumpul panas matahari berbentuk parabolic yang disebut parabolic trough solar collector. panas matahari tersebut nantinya diteruskan ke suatu receiver yang didalamnya dialiri oleh suatu fluida (heat transfer fluid/htf) yang kemudian akan meneruskan panas yang diterima oleh receiver analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari (ghalya pikra, agus salim, tri admono, merry indahsari devi) pp. 13-18 14 menuju steam generator sebagai penghasil uap yang digunakan untuk menggerakkan turbin uap untuk menghasilkan energi listrik. sebagian fluida di dalam receiver/absorber kemudian dialirkan ke tangki penyimpanan panas (heat storage) untuk disimpan dan akan digunakan saat malam hari atau ketika tidak ada matahari. sistem pembangkit listrik tenaga matahari terkonsentrasi seperti ditunjukkan pada gambar 1 dibawah ini.  gambar 1. sistem pembangkit listrik tenaga matahari [4]. pembangkit listrik tenaga matahari menggunakan parabolic trough memerlukan sistem penyimpanan panas sensibel dengan temperatur operasi antara 300°c sampai 390°c. thermal oil telah banyak digunakan sebagai fluida perpindahan panas untuk mencapai temperatur tersebut. semakin besar nilai spesifikasi panas yang dimiliki oleh fluida maka nilai kapasitas penyimpanan panasnya akan semakin besar pula, yang artinya fluida tersebut memiliki kemampuan menyimpan panas yang baik. selain fluida penyimpan panas, nilai rugi-rugi panas dipengaruhi juga oleh bahan isolasi, tebal isolasi, serta waktu penyimpanan panas di dalam tangki. bahan isolasi dengan nilai konduktivitas termal rendah memiliki kemampuan untuk mengurangi terjadinya kehilangan panas yang besar. selain itu, semakin tebal isolasi yang digunakan maka semakin rendah nilai rugi-rugi panas yang terjadi, dan semakin lama waktu yang dibutuhkan untuk menyimpan panas, maka akan semakin besar nilai rugi-rugi panas yang terjadi. bahan tangki penyimpan panas terbuat dari pelat stainless steel, kemudian dilapisi oleh pelat besi dan dilapisi lagi oleh ceramic dan alumunium foil. ceramic dipilih sebagai isolasi karena memiliki kestabilan fisik dan termal hingga 1100°c, kekuatan tarik yang tinggi, serta konduktivitas termal rendah. analisis dilakukan dengan cara menghitung kapasitas penyimpanan panas dan rugi-rugi panas pada tangki penyimpan panas. selain itu dilakukan juga perhitungan untuk rugi-rugi panas dengan tebal isolasi yang bervariasi dan dengan waktu penyimpanan yang bervariasi. makalah ini bertujuan untuk menganalisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari untuk mengetahui nilai panas yang hilang selama dilakukan penyimpanan, beserta pembahasan pengaruh besar kecilnya nilai rugi-rugi panas. ii. metode analisis analisis diawali dengan menentukan dimensi dari tangki penyimpan panas untuk mengetahui besarnya kapasitas penyimpanan. tangki penyimpan panas yang didesain untuk menganalisis rugi-rugi panas pada kali ini adalah tangki dengan bentuk silinder dengan diameter tangki dalam sebesar 0,4 m dan tinggi tangki bagian dalam sebesar 0,45 m. bahan tangki terbuat dari pelat stainless steel, yang kemudian dilapisi oleh pelat besi dengan tebal 1 mm yang merupakan pembatas ruang untuk udara dengan tebal 25 mm antara stainless steel dan pelat besi, kemudian dilapisi oleh ceramic dengan tebal 0,1 m dan alumunium foil. tangki dilapisi untuk mengurangi rugi-rugi panas sehingga kemampuan menyimpan panasnya akan baik pula. gambar desain tangki ditunjukkan pada gambar 2. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 15 gambar 2. tangki penyimpan panas. kapasitas penyimpanan tangki dihitung dengan menggunakan persamaan (1) berikut ini. (1) dimana q adalah kalor panas yang disimpan (kj), ρ adalah densitas oil (kg/m3), v adalah volume tangki (m3), cp adalah panas spesifik fluida (kj/kg°c), to adalah temperatur operasi (°c) dan t4 adalah temperatur awal (°c). gambar 3. skematik gambar laju aliran panas. gambar 4. jala-jala termal. perhitungan rugi-rugi panas diawali dengan membuat skematik gambar laju aliran panas yang dilanjutkan dengan membuat jala-jala termal yang ditunjukkan pada gambar 3 dan gambar 4 diatas. tahanan termal dihitung untuk mendapatkan rugi-rugi panas yang terjadi di dalam tangki penyimpan panas. persamaan tahanan termal 1 (r1) sampai dengan persamaan tahanan termal 4 (r4) ditunjukkan pada persamaan (2) sampai dengan persamaan (5) berikut ini. (2) (3) (4) (5) dimana r1 adalah tahanan termal dari fluida ke pelat stainless steel (ºc/w), hhtf adalah koefisien konveksi panas pada fluida (w/m2°c), r1 adalah jari-jari tabung bagian dalam (m), l adalah tinggi tabung (m), r2 adalah tahanan termal antara pelat stainless steel ke pelat besi (ºc/w), r2 adalah jariudara t0 t1 t2 t4 t1 t2 t3 t4 t0 r1 r2 r3 r4 t3 q pelat tipis/ al-foil pelat besi pelat ss oli ceramic udara t0 t4 r1 r2 r3 analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari (ghalya pikra, agus salim, tri admono, merry indahsari devi) pp. 13-18 16 jari pusat ke ceramic bagian dalam (m), kudara adalah konduktivitas termal dari udara (w/mºc), r3 adalah tahanan termal antara pelat besi ke ceramic bagian luar/ alumunium foil (ºc/w), r3 adalah jari-jari dari pusat ke ceramic bagian luar (m), kceramic adalah konduktivitas termal dari ceramic (w/mºc), r4 adalah tahanan termal dari alumunium foil ke udara luar (ºc/w) dan hudara adalah koefisien konveksi panas pada udara luar (w/m2 ºc). persamaan rugi-rugi panas pada tangki penyimpan panas ditunjukkan pada persamaan (6) berikut ini. ∆ ∆ (6) dimana qloss adalah rugi-rugi panas pada tangki penyimpan panas (w). data yang digunakan untuk melakukan analisis rugi-rugi panas pada tangki penyimpan panas ditunjukkan pada tabel 1. tabel 1. data perancangan [4], [5], [6]. data nilai diameter tangki dalam (di) 0,4 m tebal pelat besi + ceramic (x) 0,101 m tinggi tangki bagian dalam (l) 0,45 m konduktivitas termal udara dalam (kud-dlm) 0,0407 w/moc konduktivitas termal ceramic (kcer) 0,07 w/moc waktu penyimpanan (t) 12 jam konduktivitas termal udara luar (kud-luar) 0,0338 w/moc temperatur operasi (t) 250 oc panas spesifik thermal oil (cp) 1,978 kj/kg oc densitas thermal oil (ρ) 927,6 kg/m 3 konduktivitas thermal oil (koli) 0,111 w/moc temperatur operasi dengan nilai 250°c ditentukan berdasarkan hasil pengujian solar collector, dimana temperatur fluida yang terukur di dalam absorber/receiver mencapai 250°c. fluida di dalam tangki penyimpan panas mengalir dari receiver/absorber, sehingga temperatur yang terukur di dalam absorber/receiver dijadikan acuan sebagai temperatur di dalam tangki penyimpan panas untuk menganalisis rugi-rugi panas. iii. pembahasan hasil perhitungan yang dimulai dari perhitungan kapasitas penyimpanan panas hingga rugi-rugi panas di dalam tangki penyimpan panas ditunjukkan pada tabel 2. tabel 2. hasil perancangan termal. hasil nilai jenis fluida thermo oil kalor penyimpanan panas (qinput) 22814,55 kj kapasitas panas (w) 0,53 kw tahanan termal total (rtot) 3,47°c/w rugi-rugi termal (qloss) 63,43 w persentase kehilangan panas 12 % hasil analisis pada tabel 2 menunjukkan bahwa tangki penyimpan panas memiliki nilai kapasitas penyimpanan panas sebesar 2,112 kw. hal ini dipengaruhi oleh nilai panas spesifik fluida yang besar, sehingga menghasilkan kapasitas penyimpanan panas yang baik. rugi-rugi yang dihasilkan sebesar 63,43 w. hal ini dikarenakan bahan isolasi yang digunakan (ceramic) memiliki konduktivitas termal (kceramic) yang rendah, sehingga dapat melindungi panas di dalam tangki dengan baik. oleh karena itu, nilai rugi-rugi panas akan menjadi rendah bila bahan yang digunakan sebagai isolasi memiliki nilai konduktivitas termal yang rendah pula. selain itu, tebal ceramic dan waktu penyimpanan panas juga menentukan nilai rugi-rugi panas. nilai rugi-rugi panas terhadap tebal ceramic dan nilai rugi-rugi panas terhadap waktu penyimpanan panas ditunjukkan pada gambar 5 dan gambar 6 dibawah ini.  journal of vol. 01, n gamb memban rugi-rugi bahwa s panas ya terjadi k berbandi sehingga maka n rendah. gamb perbandi persenta penyimp panas y semakin dilakuka mempen tangki, d seiring d semakin f mechatronics, no. 1, 2010 gambar bar 5 m ndingkan ant i panas. pa semakin teb ang dihasilk karena teba ing terbalik a semakin te nilai rugi-ru bar 6 yang ingan pana ase rugi-rug panan panas yang disimp n kecil seirin an waktu ngaruhi nilai dimana rugi dengan wakt n lama. electrical pow r 6. grafik pan menunjukkan tara tebal k ada grafik t bal ceramic kan semakin al ceramic k dengan r ebal isolasi gi panasnya menunjukk as yang gi panas t dapat diana pan di dala ng dengan s penyimpan i rugi-rugi i-rugi panas tu penyimpa wer, and vehicu gambar 5. nas yang disim grafik keramik terh tersebut, ter maka rugi rendah. ha memiliki fu rugi-rugi p yang digun a akan men kan grafik an disimpan terhadap w alisis bahwa am tangki semakin lam nan. hal panas di d akan memb anan panas ular technology grafik tebal c mpan dan % h yang hadap rlihat i-rugi al ini ungsi anas, nakan njadi ntara serta waktu nilai akan manya ini dalam besar yang i p li 0 m s 3 p a p p k m y te d a y r b y ceramic vs qlo heat loss vs w iv. kesim analisis penyimpan istrik tenaga 0,4 m, tinggi m menghasil sebesar 0,53 3,47°c/w, ru persentase k adalah 12 % penyimpan p panas spesi kapasitas pen menjadi besa yang baik k ermal yang digunakan m akan semaki yang digunak rugi-rugi pan besar. oss. aktu penyimp mpulan rugi-rugi panas dala a matahari d tangki 0,45 lkan kapasit kw, tahan ugi-rugi pana kehilangan p %. thermo anas yang ba fik yang nyimpanan ar. ceramic m karena memi rendah. sem maka rugi-rug in kecil, dan kan untuk m nas yang di is panan panas. panas pa am sistem dengan diam m dan tebal tas penyimp nan termal t as sebesar 63 panas yang oil merup aik karena m tinggi, seh panas di da merupakan b iliki nilai k makin tebal gi panas yan n semakin menyimpan ihasilkan ak ssn 2087-3379 17 ada tangki pembangkit meter tangki ceramic 0,1 anan (daya) total sebesar 3,43 w, dan g dihasilkan pakan fluida memiliki nilai hingga nilai alam tangki bahan isolasi konduktivitas isolasi yang ng dihasilkan lama waktu panas maka kan semakin 9 i t i ) r n n a i i i i s g n u a n analisis rugi-rugi panas pada tangki penyimpan panas dalam sistem pembangkit listrik tenaga matahari (ghalya pikra, agus salim, tri admono, merry indahsari devi) pp. 13-18 18 daftar pustaka [1] wu, b., reddy, r.g., rogers, r.d., (2001, april), “novel ionic liquid thermal storage for solar thermal electric power systems”, proceedings of solar forum 2001, washington d.c. [2] dracker, r., rifflemann, k.j., (2008, july), “integrated thermal storage for concentrating solar power”, integrated energy policy report workshop july 31 2008, solar millennium llc, berkeley, ca. [3] muller, h., steinhagen, (2008), “solar thermal power plants – on the way to commercial market introduction”, institute for technical thermodynamics, german aerospace centre (dlr), stuttgard – cologne – almeria/spain. [4] firepro, (2008, august), “ceramic wool blanket”, firepro centabuild insulation, auckland. [online]. available: http://www.firepro.co.nz. [5] solutia, (2001, july), “therminol66: high performance highly stable heat transfer fluid”, solutia applied chemistry, creative solutions, europe. [online]. available: http//www.solutia.com. [6] incropera, f.p., de witt, d.p., (1990), “fundamentals of heat and mass transfer”, 3rd edition, singapore: john wiley and sons, inc. [7] duffie, j.a., beckman, b.a., (1991), “solar engineering of thermal processes”, 2nd edition, singapore: john wiley and sons, inc,. [8] blake, d.m., moens, l., hale, m.j., price, h., kearney, d., hermann, u., (2002), “new heat transfer and storage fluids for parabolic trough solar thermal electric plants”, proceedings of the 11th solarpaces international symposium on concentrating solar power and chemical energy technologies, zurich, switzerland. [9] tamme, r., laing, d., steinmann, w.d., (2003), “advanced thermal energy storage technology for parabolic trough”, proceedings of isec 2003, 2003 international solar energy conference, hawaii, pp. 1-8. mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2017.v8.85-94 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. experimental review of distance sensors for indoor mapping midriem mirdanies a, *, roni permana saputra a, b a research centre for electrical power and mechatronics, indonesian institute of sciences komp. lipi bandung, jl. sangkuriang, gd. 20, lt. 2, bandung 40135, indonesia b dyson school of design engineering, imperial college london, 10 princes gardens, south kensington, london, united kingdom received 11 september 2017; received in revised form 7 november 2017; accepted 15 november 2017 published online 28 december 2017 abstract one of the most important required ability of a mobile robot is perception. an autonomous mobile robot has to be able to gather information from the environment and use it for supporting the accomplishing task. one kind of sensor that essential for this process is distance sensor. this sensor can be used for obtaining the distance of any objects surrounding the robot and utilize the information for localizing, mapping, avoiding obstacles or collisions and many others. in this paper, some of the distance sensor, including kinect, hokuyo utm-30lx, and rplidar were observed experimentally. strengths and weaknesses of each sensor were reviewed so that it can be used as a reference for selecting a suitable sensor for any particular application. a software application has been developed in c programming language as a platform for gathering information for all tested sensors. according to the experiment results, it showed that hokuyo utm-30lx results in random normally distributed error on measuring distance with average error 21.94 mm and variance 32.11. on the other hand, error measurement resulted by kinect and rplidar strongly depended on measured distance of the object from the sensors, while measurement error resulted by kinect had a negative correlation with the measured distance and the error resulted by rplidar sensor had a positive correlation with the measured distance. the performance of these three sensors for detecting a transparent object shows that the kinect sensors can detect the transparent object on its effective range measurement, hokuyo utm-30lx can detect the transparent object in the distance more than equal to 200 mm, and the rplidar sensor cannot detect the transparent object at all tested distance. lastly, the experiment shows that the hokuyo utm-30lx has the fastest processing time significantly, and the rplidar has the slowest processing time significantly, while the processing time of kinect sensor was in between. these processing times were not significantly affected by various tested distance measurement. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: distance sensors; kinect; hokuyo utm-30lx; rplidar; indoor mapping; autonomous mobile robot; c programming. i. introduction research and development on a mobile robot that has an ability to accomplish the required task without human intervention (i.e., autonomous system) have attracted many researchers in robotics and mechatronics research field in the recent years. to operate it autonomously, it is essential for a mobile robot to have an ability to percept itself and the surrounding environment. one of the important sensors for this operation is distance sensor. on mobile robot application, distance sensor can be used for several functions, including mapping the environment based on information of distance of all object on the workspace, localizing the mobile robot on the global map based on perception of the environment and avoiding collision during the operation by detecting an obstacle or object along the robot way. some popular distance sensors used in mobile robot application are including kinect, hokuyo utm30lx, and rplidar. some research studies and applications have been published related to the implementations of these sensors. the kinect sensor was used by peter et al. for 3d mapping on the indoor application [1]. meanwhile, this sensor was also used by jagdish et al. for hand tracking study and recognizing the center of the hand [2]. moreover, midriem et al. used kinect sensor for detecting and calculating the distance of specific object for weapon * corresponding author. tel: +62 22 250 3055 e-mail address: midr001@lipi.go.id https://dx.doi.org/10.14203/j.mev.2017.v8.85-94 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.85-94 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.85-94&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 86 system application [3]. on the other hand, nicolas et al. have used hokuyo utm-30lx sensor, for detecting an obstacle on electrical wire routes [4], while ji et al. using it for a real-time method for depth enhanced visual odometry [5]. meanwhile, rplidar sensor has been used by marni et al. for scanning and mapping on the indoor environment [6]. similarly, mirna et al. were also used this sensor on the autonomous mobile robot for mapping the environment [7]. in this paper, kinect, hokuyo utm-30lx, and rplidar sensor will be analyzed and discussed to see the actual performance of these three sensors to detect two different types of objects, non-transparent and transparent objects in the various tested distance. a software application created by c programming has been developed to utilize data from each sensor. the experiment results in this paper can be used as references to select the right distance sensor for further applications. ii. research method a. distance sensors kinect, hokuyo utm-30lx, and rplidar sensors discussed in this paper are presented in figure 1, figure 2, and figure 3. the kinect sensor in figure 1 is a sensor used for xbox 360 console. this sensor consists of four main components, rgb camera, 3d depth sensor, microphone array and motorized tilt made by microsoft [8]. the depth sensor component on the kinect can be used to localize objects on threedimensional coordinate frames, i.e., x, y, and z on meter unit. some related specifications of this kinect sensor can be seen in table 1. based on the specification list in table 1, this sensor has effective distance measurement from 0.8 to 4.0 meter. meanwhile, hokuyo utm-30lx is one of light detection and ranging (lidar) technologies that can measure object distance and bearing by emitting laser signal into the measured object. after that, the reflected laser signal will be read for calculating the object distance. the object distance is calculated based on time of flight (tof) of the laser signal. some related specifications of this hokuyo utm30lx sensor are listed in table 2 [9]. according to this list, the effective distance measurement capable by this sensor is between 0.1 and 30 meters, with accuracy about ± 30mm. on the other hand, rplidar sensor was designed as a low-cost two-dimensional laser scanner compare to the existed commercial laser scanner. these sensor measures object distance using triangulation principle such as illustrated in figure 4. generally speaking, rplidar has three main components, signal transmitter system, vision acquisition system, and a motor system that spins these two previous components. the transmitter component emits the modulated laser infrared signal that will hit an object. after that, the vision acquisition system will catch the reflected infrared signal from the object, and the distance will be calculated based on the triangulation principle. the general specification of this rplidar sensor can be seen in table 3 [10]. based on the data, it shows that this sensor has angular span 360 degrees with less than one-degree resolution. the effective measuring distance is about 0.2 to 6 meter. figure 1. kinect figure 2. hokuyo utm-30lx figure 3. rplidar table 1. kinect specification parameter specification effective measurement distance 0.8 4.0 meter measurement range angle 43° on vertical 57° on horizontal accuracy n/a tilt ±27° frame rate 30 frames per second (fps) table 2. hokuyo utm-30lx specification parameter specification effective measurement distance 0.1 – 30 meter accuracy 0.1 – 10m : ± 30mm scan speed 25 msec/scan scan angle 270° angular resolution 0.25° table 3. rplidar specification parameter specification distance range 0.2 6 meter (typically) distance resolution < 0.5 mm or < 1% of the distance angular range 0 360° angular resolution ≤ 1° scan rate min: 1 hz, max: 10 hz m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 87 b. experimental methods and measuring techniques in this study, experimental testing has been conducted on these three different sensors, i.e., kinect, hokuyo utm-30lx, and rplidar. this experiment is performed to review the actual performance of these sensors on measuring object distance. the objects used in this experiment consist of two different types, non-transparent object, and transparent object. a dark green metal plate object with a thickness of 0.8 mm shown in figure 5 is used to represent the nontransparent object. meanwhile, the 5 mm thick glass used to represent the transparent object can be seen in figure 6. the main purpose of the non-transparent object experiment is to observe the performance of these sensors to measure the object distance in the various tested distance on the same object. more specifically, this experiment will observe the measurement variance of each sensor on the same object and same distance, the effect of the measurement distance into measurement error of each sensor and the actual range measurement of each sensor. in this experiment, the same object is measured on the distance 100 to 3000 mm, with every 100 mm iteration. the process layout of this experiment can be illustrated as in figure 7. on the other hand, the transparent object experiment is conducted to observe the sensitivity of each sensor to detect a transparent object. moreover, this experiment is also observing the effect of the transparent object to the distance measurement result of the non-transparent object behind it. in other words, this experiment will observe the refraction effect of the glass to the distance measurement result of each sensor. this experiment is performed by placing the glass in front of the sensors in various distances, 100, 200, 300, 400, and 500 mm and also placing the dark metal plate behind the glass on 2000 mm in front of the sensors. the process layout of this second experiment can be illustrated as in figure 8. figure 4. distance measurement illustration of the rplidar sensor with the triangulation principle figure 5. metal plate object figure 6. transparent glass object figure 7. design plans for the distance sensors to calculate the metal plate object figure 8. design plans for the distance sensors to calculate the transparent glass object m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 88 c. obtaining data from the sensors figure 9 shows the flowchart of the software application for obtaining distance measurement data from the sensors. this application is developed on c programming platform using visual studio ide which can be seen in figure 10. the program records all obtained distance data and processing time of each sensor on the text file for each experiment. all sensors are connected to the pc through usb connection. the data that is accessed by the program on this experiment represents the distance data on of the object in the direction perpendicular to the center of each sensor. the corresponding data for kinect sensors is the data on the pixel 320x240 on the depth image frame. the corresponding data for the hokuyo utm-30lx is the distance data on the 540th step. meanwhile, on the rplidar sensor, the accessed data is the data on the scanning angle zero degrees. iii. result and discussion the results of these experiments were evaluated to determine the actual performance of each sensor based on these actual result. a. experiment result in the non-transparent object the measurement results of these three sensors on the non-transparent object placed on 100 up to 3000 mm on distance can be seen in table 4. according to these results, it can be summarized in table 5, the actual distance measurement range that can be covered by these sensors on the experiment. comparing this result with the specification in table 2, it was shown that in reality the actual measurement of the measuring range of the sensor, particularly the kinect sensor, performed under its manufacturing specifications. it might be affected by various things, including the lighting effects in the room when the testing process performed, the type of the object being detected and also the color of the object being detected. figure 9. flowchart of the software application for obtaining distance measurement from the sensors figure 10. visual studio ide m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 89 the errors of the distance measurements from each sensor on this experiment were presented in figure 11a, figure 11b, and figure 11c. according to the graph on the figure 11b, it was shown that the measurement error of the hokuyo utm-30lx on all tested distance did not indicate any particular significant trend. in contrast, the graphs in figure 11a and 11c showed particular trends of the measurement error of the kinect and rplidar sensors. these graphs indicated negative and positive slope, respectively. the correlation between tested actual distance and measurement error results on each sensor could also be evaluated using the pearson correlation method [11]. the correlation coefficient between the measurement error and the distance of the object from the sensors could be seen in table 6. based on correlation coefficient shown in table 6, it confirmed the rapid conclusion based in figure 11 that the error on hokuyo sensor had no strong correlation with tested distance, while kinect and rplidar sensors had negative and positive correlations, respectively. more specifically, since kinect and rplidar sensors had strong correlations between measurement error and tested distance, these correlations can be modeled using fitted linear regression model. the linear fitted line plot regression of these correlations on the kinect and rplidar sensors could be seen in figure 12, and the model equations for these sensors were listed in table 7. according to figure 12, it was shown that linear regression model on the rplidar sensor could result in a well-fitting model, while on kinect sensors, the linear regression model results in a less-fitting model. the r-squared values also indicated that the estimated model for correlation error on the rplidar sensor was much closer to perfect model with r-squared value 94.1% compared to the model for correlation error on the kinect sensor with r-squared value 64.2%. meanwhile, since there was no significant correlation between tested distance and measurement error resulted by hokuyo sensor, the measurement error can be evaluated and modeled as a normally distributed error model. table 8 showed the statistical summary of the measurement error resulted by hokuyo sensor on this experiment. the normality of the error of this sensor was evaluated based on the residual distribution of this error. figure 13 demonstrated the residual plots of the measurement error on the hokuyo sensor. according to the normal probability plot in the figure, it indicated that the residual error was well-fitted being modeled table 5. the actual distance measurement range that can be covered by the three sensors on the experiment sensor min max kinect > 400 mm < 1900 mm hokuyo 0 ≤ 100 mm ≥ 3000 mm rplidar 0 ≤ 100 mm ≥ 3000 mm table 6. the correlation coefficient between the measurement error and the distance of the object from the sensors sensor correlation coefficient kinect -0.808 hokuyo 0.435 rplidar 0.97 table 7. the model equations for the three sensors to distance measurement linear regression equation model r-sq value e_kinect = 14.78 0.013 tested_distance 64.2 % e_rplidar = 7.89 + 0.093 tested_distance 94.1 % table 8. descriptive statistical summary of measurement error resulted by hokuyo sensor statistical parameter hokuyo observation number (n) 300 mean 21.94 stdev 5.67 variance 32.11 minimum value 4 maximum value 37 range 33 table 4. the measurement results of the three sensors on the nontransparent object actual distance distance measurement average kinect hokuyo rplidar 100 n/a 127.6 131.575 200 n/a 223.2 234.275 300 n/a 321.4 343.025 400 n/a 419.7 443 500 509.8 521.6 543.2 600 606 620.1 647.85 700 706.6 718.3 752.65 800 803.6 815.9 865 900 901 914.9 975.125 1000 1003 1017.1 1079.9 1100 1098.8 1113.5 1183.075 1200 1202 1212.2 1294.8 1300 1294 1312.4 1399.85 1400 1403.5 1422.8 1505.8 1500 1499.7 1524 1606.525 1600 1590.4 1623.5 1730.925 1700 1697.2 1722 1840.275 1800 1786.9 1823.7 1944.275 1900 n/a 1926.5 2055.05 2000 n/a 2020.4 2149.525 2100 n/a 2123.6 2280.2 2200 n/a 2223.2 2380.425 2300 n/a 2323.7 2493.025 2400 n/a 2420.2 2603.325 2500 n/a 2526.5 2726.875 2600 n/a 2627 2810.65 2700 n/a 2728.4 2969.7 2800 n/a 2827.7 3090.9 2900 n/a 2930.6 3188.125 3000 n/a 3025.6 3317.5 m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 90 as a normal distribution model. moreover, versus fits the plot, and versus order plot did not show any particular trend. it indicated that the error was the independent one to the others in any observation. also, the normality of this residual error could be seen visually on the histogram on the figure. thus, based on this observation and evaluations, the measurement error resulted by hokuyo sensor was well-fitted to be modeled as normally distributed error with mean 21.94 and variance 32.11. in this experiment, apart from the evaluation of the error of the distance measurement results, the processing time required by each sensor to process one cycle measurement was also evaluated. on kinect sensor, every one cycle, this sensor measure object distance covering the threedimensional frame with scope 43° in the vertical direction and 57° in the horizontal direction. it was (a) (b) (c) figure 11. the errors of the distance measurements from each sensor on this experiment; (a) kinect; (b) hokuyo; and (c) rplidar m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 91 represented by 320 x 480 pixels of depth image frame. conversely, hokuyo utm-30lx only covers twodimensional plane distance measurement. one cycle on this sensor covers the measurement of the 270 degrees scope. similar to the hokuyo utm-30lx, rplidar was also cover two-dimensional plane distance measurement. this sensor could cover the scope of 270 degree measurement of distance on everyone measurement cycle. figure 14 showed the processing times required by these sensors on measuring object on the various distances on every one cycle measurement. based on figure 14, it could be rapidly seen that no significant trend showed the correlation between processing time and tested distance on each sensor measurement results. more specifically, the correlation between processing time and tested distance on each sensor measurement results could be evaluated using pearson correlation method. the correlation coefficient between the processing time and distance measurements from three tested sensors could be seen in table 9. from the table 9, it could be seen that the correlation coefficient between measurement time and measurement distance was relatively small for each sensor, so generally speaking, the tested distances on the measurement processes had no significant effect on the measurement processing time. the average measurement processing time of one cycle of the three sensors could be seen in table 10. practically, one cycle, rplidar sensor needs significantly much longer processing time than the two other sensors. meanwhile, hokuyo utm-30lx sensor required the fastest processing time compared to the others. (a) (b) figure 12. the linear fitted line plot regression of these correlations on the kinect and rplidar sensors; (a) kinect and (b) rplidar table 10. the average measurement processing time sensor the average measurement processing time (ms) kinect 13.49165 hokuyo 3.843492 rplidar 125.7597 table 9. the correlation coefficient between the processing time and distance measurements sensor correlation coefficient kinect -0.056 hokuyo -0.112 rplidar -0.093 m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 92 b. experiment result on the transparent object table 11 presented the measurement results of the transparent object’s distance using kinect, hokuyo utm-30lx, and rplidar sensors. it could be seen clearly that the kinect sensor can adequately detect the transparent glass at its effective distance (i.e., ≥ 500 mm), as the hokuyo utm-30lx sensor could only detect the transparent glass for measuring the distance of more than equal to 200 mm. by contrast, the rplidar sensor cannot detect the transparent glass at all, for any tested distance. when the transparent glass was not detected, the detected object is the object behind the glass, which was the dark green metal plate. this plate was placed at a distance of 2000 mm from the sensor. table 12 showed the comparison of distance measurement result of the metal plate placed on 2000 mm, with glass existing and without glass existing for hokuyo utm-30lx and rplidar sensors. the comparison of the error of these measurement results could be seen in figure 15a and 15b. based on table 12 and figure 15, it showed that the average error of measurement object by the sensor hokuyo through transparent glass was -54 mm, and without a transparent glass was 20 mm. figure 13. the residual plots of the measurement error on the hokuyo sensor figure 14. the processing times required by these sensors on every one cycle measurement table 11. the measurement results of the transparent object’s distance transparent glass position (mm) metal plate position (mm) the measurement results (mm) kinect hokuyo rplidar 100 2000 n/a 1946.4 2087.075 200 n/a 232.4 2101.05 300 n/a 340.3 2138.05 400 n/a 420.1 2146.125 500 508.5 559.4 2150.25 m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 93 table 12. the comparison of distance measurement result of the metal plate, with and without glass existing metal plate distance (mm) transparent glass distance (mm) the measurement results (mm) with transparent glass intercession without transparent glass intercession hokuyo rplidar hokuyo rplidar 2000 100 1945 2095.25 2021 2151 1947 2094.5 2020 2139.5 1943 2094.5 2019 2150.5 1946 2082 2019 2150.25 1949 2081.75 2021 2150.5 1945 2069.25 2020 2150.5 1945 2082.25 2022 2162.75 1946 2082 2017 2150.75 1952 2094.5 2024 2150.5 1946 2094.75 2021 2139 (a) (b) figure 15. error measurement result of the hokuyo and rplidar sensors with or without glass existing (a). hokuyo; (b). rplidar meanwhile, the average error of measurement object by the sensor rplidar through transparent glass was 88 mm, and without a transparent glass was 149 mm. these results showed roughly that the glass appearance affects the measurement result of these sensors. this effect was as a result of diffraction phenomenon. statistically, this comparison was also can be tested using the 2-sample t-test method. the m. mirdanies and r.p. saputra / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 85–94 94 result of t-test could be seen in table 13. the comparison of the hokuyo sensor results t-value as 74.5, and the rplidar sensor results t-value as -17.81. the comparison results on both two sensors showed the high t-values. it confirmed that even though the glass cannot detect by the sensors, the glass appearance significantly affects the distance measurement result of the hokuyo and rplidar sensors. iv. conclusion an experimental testing on the kinect, hokuyo utm-30lx, and rplidar sensors had been conducted to test the actual performance of these three sensors using two different types of objects, non-transparent object, which was a dark green metal plate, and a transparent object, which was a 5 mm thick transparent glass. the kinect sensor could detect objects with a minimum distance of > 400 mm, while the hokuyo and rplidar sensors already could detect an object in the distance about 100 mm (i.e., the minimum distance tested in this experiment). while the hokuyo utm-30lx and rplidar sensors could detect the object on the distance up to 3000 mm (i.e., the minimum distance tested in this experiment), on this experiment, the kinect sensor could only detect the object on maximum distance 1900 mm. considering the various distance measurement in this experiment, the results showed that the hokuyo utm30lx did not have a strong correlation between the measurement errors and the measurement distance tested. more specifically, the normality indicated that the error resulted by this sensor is well-fitted modeled as a normally distributed error with mean 21.94 mm and variance 32.11. in contrast, the measurement errors resulted by kinect and rplidar sensors had strong correlations with the measurement distance tested the error on the kinect sensor had a strong negative correlation, while the error resulted by rplidar sensor had a strong positive correlation with the tested distance. the performance of these three sensors for detecting a transparent object tested in this experiment (i.e., 5 mm thick transparent glass), showed that the kinect sensor could detect the transparent object on its effective range measurement, and hokuyo utm-30lx could detect the transparent object in the distance more than equal to 200 mm. on the other hand, the rplidar sensor cannot detect the transparent object at all tested distance. while the transparent object was not detected by the sensors, this object still significantly affected the measurement result of the sensor when measuring the distance of the object behind this transparent object. lastly, the performance of these three sensors regarding processing time, it was shown that the hokuyo utm30lx had the fastest processing time significantly, and the rplidar had the slowest processing time significantly, while the processing time of kinect sensor was in between both. these processing times were not significantly affected by various tested distance measurement. acknowledgement authors would like to thank to the research centre for electrical power and mechatronics indonesian institute of sciences (lipi) that has supported this research and all those who have helped in conducting this research. references [1] p. henry et al., “rgb-d mapping: using kinect-style depth cameras for dense 3d modelling of indoor environments,” the international journal of robotics research, vol. 31, no. 5, pp. 647-663, 2012. [2] j. l. raheja et al., “tracking of fingertips and centers of palm using kinect,” in third international conference on computational intelligence, modelling & simulation, langkawi, 2011. [3] m. mirdanies et al., “object recognition system in remote controlled weapon station using sift and surf methods,” journal of mechatronics, electrical power, and vehicular technology, vol. 4, no. 2, pp. 99-108, 2013. [4] n. pouliot et al., “linescout power line robot: characterization of a utm-30lx lidar system for obstacle detection,” in ieee/rsj international conference on intelligent robots and systems, vilamoura, 2012. [5] j. zhang et al., “a real-time method for depth enhanced visual odometry,” auton. robots, vol. 41, no. 1, pp. 31–43, jan. 2017. [6] a. m. markom et al., “indoor scanning and mapping using mobile robot and rp lidar,” int'l journal of advances in mechanical & automobile engg. (ijamae), vol. 3, no. 1, pp. 42-47, 2016. [7] a. m. markom et al., “a mapping mobile robot using rp lidar scanner,” in ieee international symposium on robotics and intelligent sensors (iris), langkawi, 2015. [8] microsoft, “kinect for windows sensor components and specifications,” microsoft, us, 2016. [9] hokuyo, “scanning laser range finder utm-30lx/ln specification,” hokuyo automatic co., ltd, 2012. [10] robopeak team, “rplidar low cost 360 degree 2d laser scanner (lidar) system,” 2014. [11] j. adler dan i. parmryd, “quantifying colocalization by correlation: the pearson correlation coefficient is superior to the mander's overlap coefficient,” cytometry part a, vol. 77a, no. 8, pp. 733-742, 2010. table 13. the comparison of distance measurement result of the metal plate, with and without glass existing sensor condition n error average stdev average different t-value hokuyo with transparent object 10 -53.6 2.5 -74 -74.5 without transparent object 10 20.4 1.9 rplidar with transparent object 10 211.98 4.35 -62.45 -17.81 without transparent object 10 274.43 2.08 https://doi.org/10.1177/0278364911434148 https://doi.org/10.1177/0278364911434148 https://doi.org/10.1177/0278364911434148 https://doi.org/10.1177/0278364911434148 https://doi.org/10.1109/cimsim.2011.51 https://doi.org/10.1109/cimsim.2011.51 https://doi.org/10.1109/cimsim.2011.51 https://doi.org/10.1109/cimsim.2011.51 http://dx.doi.org/10.14203/j.mev.2013.v4.99-108 http://dx.doi.org/10.14203/j.mev.2013.v4.99-108 http://dx.doi.org/10.14203/j.mev.2013.v4.99-108 http://dx.doi.org/10.14203/j.mev.2013.v4.99-108 https://doi.org/10.1109/iros.2012.6385476 https://doi.org/10.1109/iros.2012.6385476 https://doi.org/10.1109/iros.2012.6385476 https://doi.org/10.1109/iros.2012.6385476 https://doi.org/10.1007/s10514-015-9525-1 https://doi.org/10.1007/s10514-015-9525-1 http://dx.doi.org/10.15242/ijamae.er01163003 http://dx.doi.org/10.15242/ijamae.er01163003 http://dx.doi.org/10.15242/ijamae.er01163003 http://dx.doi.org/10.15242/ijamae.er01163003 https://doi.org/10.1109/iris.2015.7451592 https://doi.org/10.1109/iris.2015.7451592 https://doi.org/10.1109/iris.2015.7451592 https://msdn.microsoft.com/en-us/library/jj131033.aspx https://msdn.microsoft.com/en-us/library/jj131033.aspx https://www.hokuyo-aut.jp/search/single.php?serial=169 https://www.hokuyo-aut.jp/search/single.php?serial=169 https://www.robotshop.com/media/files/pdf/user-manual-rplidar.pdf https://www.robotshop.com/media/files/pdf/user-manual-rplidar.pdf https://doi.org/10.1002/cyto.a.20896 https://doi.org/10.1002/cyto.a.20896 https://doi.org/10.1002/cyto.a.20896 https://doi.org/10.1002/cyto.a.20896 kata pengantar journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 95-104, 2011 p-issn 2087-3379 © 2011 rcepm lipi all rights reserved doi: 10.14203/j.mev.2011.v2.95-104 mathematical modeling of a moving planar payload pendulum on flexible portal framework pemodelan matematik dari pendulum payload bidang yang bergerak di atas frame portal fleksibel edwar yazid research centre for electrical power and mechatronics – indonesian institutes of sciences komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, west java 40135, indonesia edwar.putra@gmail.com received: october 17th, 2011; revised: november 1st, 2011; accepted: december 9th, 2011; published online: december 22th, 2011. abstrak pemodelan matematik sebuah pendulum beban bidang yang bergerak di atas frame portal fleksibel ditampilkan dalam tulisan ini. persamaan gerak dari sistem yang demikian diperoleh melalui pemodelan frame portal menggunakan elemen hingga bersamaan dengan metode elemen hingga bergerak dan pendulum beban bidang menggunakan persamaan lagrange. persamaan yang diturunkan menunjukkan adanya kaitan tidak linear antara dinamika portal frame dan pendulum beban. teknik integrasi numerik gabungan langsung, yaitu newmarkdan runge-kutta orde ke-empat selanjutnya digunakan untuk menyelesaikan persamaan gerak yang terkait tersebut. beberapa simulasi numerik dilakukan dan hasilnya diverifikasi dengan beberapa perbandingan. hasilnya menunjukkan bahwa amplitudo dan frekuensi dari sudut ayunan pendulum beban sangat dipengaruhi oleh fleksibilitas struktur dan kabel dalam hal kecepatan pembawa beban. kata kunci: pendulum beban, portal framework, metoda elemen hingga bergerak, persamaan lagrange. abstract mathematical modeling of a moving planar payload pendulum on elastic portal framework is presented in this paper. the equations of motion of such a system are obtained by modeling the portal frame using finite element in conjunction with moving finite element method and moving planar payload pendulum by using lagrange’s equations. the generated equations indicate the presence of nonlinear coupling between dynamics of portal framework and the payload pendulum. the combinational direct numerical integration technique, namely newmark and fourth-order runge-kutta method, is then proposed to solve the coupled equations of motion. several numerical simulations are performed and the results are verified with several benchmarks. the results indicate that the amplitude and frequency of the payload pendulum swing angle are greatly affected by flexibility of structure and the cable in term of carriage speed. keywords: payload pendulum, portal framework, moving finite element method, lagrange’s equations. i. introduction the vibrational motion induced by a suspended load moving on flexible structures is one of important vibration problems in variety of engineering systems, such as civil, aerospace and mechanical engineering. generally, such a system may be found in crane systems which are most widely used in factories, warehouses, shipping yards and nuclear facilities. the constructions of crane’s supporting structure are usually designed to have very strong structures and big dimension in order to lift and transfer suspended heavy loads. however, as the lifting capacities become higher, the size of crane increases significantly. this condition leads to the consequence that the elastic deformability of all elements of the structure cannot be neglected [1]. furthermore, the presence of structural and cable elasticity is known to exhibit an inherent property of vibration when subjected to dynamic loads, leading to crane component or structural damage. if the crane system (trolley, hoist mechanism, rigging and payload) is taken as a moving subsystem, then this moving subsystem will induce the crane framework and conversely. they will create bidirectional dynamic interaction and constitute nonlinear coupling between crane and its framework, affecting the motion of each direction to each other. however, to the best of author’s knowledge, the published papers and conferences relate with http://dx.doi.org/10.14203/j.mev.2011.v2.95-104 mathematical modeling of a moving planar payload pendulum on flexible portal framework (edwar yazid) jmev 02 (2011) 95-104 96 this case are limited. some cited references related to this paper can be referred in [2]-[7]. among those references, paper [6] has studied such a case by introducing the concept of moving finite element method, but the dynamics of payload is not introduced in his work and restricted to rigid cable. he also discussed only dynamic responses of crane framework. this paper is addressed to generate mathematical model of a moving planar payload pendulum by introducing the flexibility of portal framework and cable into the model in an effort to propose a computational technique for dynamic response prediction by which allow us to investigate the bidirectional dynamic interaction between the payload pendulum and portal framework. moreover, the proposed mathematical model can be used for advance dynamic analysis and basis for controller design. ii. mathematical modeling of system a. system description a moving planar payload pendulum on flexible portal framework is manifestation of a planar gantry crane. this crane system can be divided into two subsystems, namely gantry crane and stationary crane framework. gantry crane incorporates interaction among trolley, wire rope as hoist cable and payload which is manipulated by trolley and hoist mechanism. the payload is grabbed using hook system, which is then hoisted from trolley by means of cable. for convenience hereafter, trolley is called as carriage, payload as payload pendulum and crane framework as a portal frame. for simplicity of the characteristics of the physical gantry crane, several assumptions are put forward to the proposed mathematical model. mass of carriage and payload pendulum is modeled as lumped mass which is connected by extensible hoist cable. payload and its cable behave as pendulum model as depicted in fig. 1. because of its natural characteristic, the angle of the payload swing has one angle with respect to the inference frame. θ is denoted as angle between the xt -axis and xtyt plane as defined by fig. 1b. the payload swings either small or large swing angles. friction between carriage and the top beam of portal framework, hoist cable and drum in hoist system and dynamics of carriage and hoist drive mechanism are not considered. the vibration effect of the entire motion portal framework can be negligible because of low and constant speed [8]. this assumption makes its supports can be fixed to the ground. structural members of crane framework have constant cross-sections, materially and geometrically linear so it is only applicable for small deformation. because the portal framework is classified as a planar frame, the used structural element is 2d beam element. b. system modeling the equations of motion of the system can be derived by means of second order of lagrange’s equations, showing in eq (1). ( ) ( ).,,,,,,,, , , δθδθ   tttttt i r xvuqxvuq f q f q l q l dt d == = ∂ ∂ + ∂ ∂ −      ∂ ∂ (1) y x bl fh pc θ tm pm  k xf (a)  θ tm pm tu tv ty tx k xf tx (b) figure 1. overall system, (a) finite element model of system, (b) planar payload pendulum model on flexible portal framework. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 95-104, 2011 p-issn 2087-3379 97 the first two terms of ( )δθ,,, ,ttt xvuq = are defined as the generalized coordinates to describe the elastic deformation of portal framework in the two directions and the rest is payload pendulum motion. general velocity of the system is ( ).,,,, δθ  ttt xvuq = the position vector of carriage vt and payload pendulum rp as shown in fig. 1 can be expressed as ( )( ) ( )( ) jtxvhitxutxr tfttt ,,)( ++⋅+= (2a) ( ) ( )( ) ( ) ( )( ) jtxvh itxutxr ptf pttp θδ θδ cos, sin,)( +−++ +++=   (2b) where i, j, and k are unit vectors along the x-, y-, and z-axis, respectively. for convenience, elastic displacements in eq. (2a)-(2b) can be expressed in terms below. ( ) ( ) .|),(, ,|),(, t t xxtt xxtt txvtxvv txutxuu = = == == (3) the term xt is position of moving carriage along the span of top beam of portal framework lb, which is time-dependent and so are terms ut, vt. it is seen also that the height of portal framework hf is included either in carriage or payload pendulum position with respective to the global coordinate system of portal framework. referring to eq. (2), the flexibility of portal framework ut, vt and hoist cable (δ) is considered in the position vector of carriage and payload pendulum. the flexibility of hoist cable is modeled as one linear spring with stretched length l. this is sufficient approach since the cable is assumed to be in tension during normal crane operation [9]. the linear spring force of hoist cable is as follows. ( ).pk kkf  −== δ (4) it is noted that notation k is cable stiffness, while lp is unstreched hoist cable. generalized force is denoted as fi, namely fx and fy which are applied input force for the x and y motions, respectively. kinetics energy of the system k is the kinetics energy of carriage and payload pendulum kg and portal framework kf, defined as follows, 22 2 1 2 1 ppttptg rmrmkkk  ⋅+⋅=+= (5a) { } [ ]{ }. 2 1 umuk t f = (5b) . 2 1                               = t t r vvuvrv vuuuru rvrurr t t t r v u u mmm mmm mmm v u u ttttt ttttt tt       the total potential energy of the system p is the potential energy of gantry carriage and payload pendulum pg and portal framework pf, expressed as follows, ( ) ( ) ( ) 22 1cos δθδ kgm gvmmghmm pppp pp tptfpt kptg ++− +++= ++=  (6a) { } [ ]{ }                               = = t t r vvuvrv vuuuru rvrurr t t t r t f v u u kkk kkk kkk v u u ukup ttttt ttttt tt 2 1 2 1 (6b) where [m] and [k] are global mass and stiffness matrices of the portal framework, mt and mp are carriage and payload mass, tr and pr are velocity vector carriage and payload pendulum, which can be obtained the time derivative of tr and pr . notation ur and its derivative indicate vectors of displacements and velocities for the rest of the degrees of freedom of the portal framework, while notations ( )tt vu , and its derivative indicate the nodal displacements and velocities with respect to the position vector of carriage and payload pendulum. notation rf in eq. (1) is dissipation function which can be expressed, { } [ ]{ } . v u u ccc ccc ccc v u u 2 1 ucu 2 1 f t t r tvtvtutvrtv tvtututurtu trvtrurr t t t r t r                               = =        (7) in this paper, structural damping matrix [ ]c in eq. (7) is determined by means of rayleigh damping theory. the lagrangian l is defined as l=k–p where k is kinetics energy and p is potential energy of the system and expressed in eq. (8). mathematical modeling of a moving planar payload pendulum on flexible portal framework (edwar yazid) jmev 02 (2011) 95-104 98 ( )( ) ( ) ( ) ( ) ( ) ( ) ( ) 2 222222 222 222 2 1cos 2 1 2 sincossin2 cossincos2 cossincos2 2 2 1 22 1 2 1 , δθδ θδθδδθ θθδδθθθ θθδδθθθ θθδδθθθ kgmgvmmghmm v u u kkk kkk kkk v u u v u x xuxvu m xuxvumm v u u mmm mmm mmm v u u l pkl pptptfpt t t r vvuvrv vuuuru rvrurr t t t r pp tp tp tp ttttt p tttttpt t t r vvuvrv vuuuru rvrurr t t t r ttttt ttttt tt ttttt ttttt tt −+++−+−                               −                   ++++ +−+ +++ +++ +++ + +++++                               = −=              (8) due to the carriage traverses along the top beam of portal framework, and assumed that the moving carriage carrying a planar payload pendulum modeled as moving lumped mass is always in contact with the top beam, the axial ( )tu and vertical ( )tv vibration of the portal framework are based on position tx and time t of carriage. the axial (x) and vertical (y) displacements of portal framework element at position x, can be obtained as below, 441 1 ss dndnu += (9a) 653\2 6532 ssss dndndndnv +++= (9b) where ( )61−== id is are the displacements for the nodes of the portal frame element at which the carriage locates. thus, the eq. (9) can be rewritten as follows. ( ) { } { } usuk k dntxu =, (10a) ( ) { } { }vsvk kdntxv ., = (10b) terms { } 4,1== kun uk and { } 6,5,3,2== kvn vk are shape functions of 2d beam element associated with translation degrees of freedom in three directions axial ( )x and vertical ( )y , and terms { } usk d , { } vsk d are displacements in two directions. derivatives of ( )txu , with respect to time t and position x are in eq. (11a), ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ).t,xuxt,xu xt,xu2xt,xu t t t t,xu t x x t,xu t x t,xu x t t t t,xu x t x x t,xu t t,xu t,xuxt,xu t t t t,xu t x x t,xu t t,xu ' '2'' ' '' 2 2 '      ++ += ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ = ∂ ∂ += ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ = ∂ ∂ (11a) derivatives of ( )txv , with respect to time t and position x are in eq. (11b), ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ).,, ,2, ,, , ,,, ,, ,,, ' '2'' ' '' 2 2 ' txvxtxv xtxvxtxv t t t txv t x x txv t x txv x t t t txv x t x x txv t txv txvxtxv t t t txv t x x txv t txv      ++ += ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ = ∂ ∂ += ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ = ∂ ∂ (11b) due to the carriage moves along a vibrating path, then coriolis acceleration will occur as shown in eq. (11). an example, eq. (11a) is applied to the general element displacement in eq. (10a) yields: journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 95-104, 2011 p-issn 2087-3379 99 ( ) { }{ } ( ) { }{ } ( ) { }{ } ( ) { }{ } ( ) { }{ } vsk vskvsk vskvsk k kk kk dn tx txv dn t txv dn t txv dn x txv dn x txv   ' 2 2 2 '' 2 2 ' , , , , , , , = ∂∂ ∂ = ∂ ∂ = ∂ ∂ = ∂ ∂ = ∂ ∂ (12) this is also applicable for in eq. (11b), where the terms { }'kn and { }''kn indicate the partial derivative of shape functions with respect to x . by substituting eq. (12) into eq. (11), an expression for the acceleration of the carriage, ( ) ( )( )txvtxu ,,,  , can be obtained, ( ) ( ) { } { } ( ){ } { } { } { } { } { }kuskus kus kus nunux nutxx nutxxtxu kk k k    ++ ++ += ' ' ''2 2 , (13b) ( ) ( ) { } { } ( ){ } { } { } { } { } { }. 2 , ' ' ''2 kvskvs kvs kvs nvnvx nvtxx nvtxxtxv kk k k    ++ ++ += (13c) equation (13) represents the acceleration of the portal framework in terms of the shape functions, nodal displacements and the velocity and acceleration. further, by deriving l in eq. (8) with respect to generalized coordinates and substituting into eq. (1) together with eq. (7), it yields equations, which derived and summarized in eq. (14a)-(14d). the system matrices in eq. (14d) are time variant, with the entries being directly dependent upon the position of the point mass along the beam. ( )( ) x ppp p pp ttttttttpt fm xxuxuxuumm =           ++− +− ++++++           θδθθδθθδ θδθθθθθ sincos2sin cossincos 2 2 2 '2''' (14a) ( ) ( ) 0 sinsin2 12 sinsin2 coscoscoscos 2 2 '2''' 2 '2''' 22 =                           +++       +++++       +++++       ++      + ppp p ttttttt pp ttttttt pp t pp gg xvxvxvv xuxuxuu x           θδθθδ θδ θδθ θδθθδθ (14b) ( ) ( ) 0 cos 2cos 2sinsin 2 2'2''' '2''' =                 +−− +−+++− ++++ pppp p ttttttt p ttttttt pp t m kg xvxvxvv xuxuxuux         δθθδ δθθ θθ (14c) the coupling terms in equation (14a), { }{ }{ }ktk nnm , { }{ }{ }'2 ktk nnmv , { }{ }{ }''2 ktk nnmv and { }{ }mgn tk are inertial, coriolis, centrifugal force and gravitational load of moving carriage, respectively, which is time dependent, and move within the structural matrices as the moving lumped mass travels from one element to another. notations [ ] [ ] [ ]ststst kcm ,, are the mass, damping and stiffness matrices of the portal framework, respectively. they are obtained by assembling all its all element mass and stiffness through the direct stiffness method, and imposing the prescribed boundary conditions. again, by assuming it is always in contact with the top beam of portal frame, there will be transmitted forces to the portal framework from the swinging payload pendulum through the hoist cable and contact force at contact point between the carriage and the top beam of portal frame. this is exciting forces for the portal frame in the x and y directions. the component and magnitude of these exciting forces are given by the right side of eq. (14d). under assumption that the crane framework is to be rigid or called rigid model, vibration in the eq. (14) is vanished. mathematical modeling of a moving planar payload pendulum on flexible portal framework (edwar yazid) jmev 02 (2011) 95-104 100 [ ] ( ){ } { } ( ){ } { } [ ] ( )( ){ } { } ( )( ){ } { } [ ] ( ) ( ) { } { } { } { }( ) ( ) ( ) { } { } { } { }( ) { } ( ) { } ( )                                     ++           +−− −−−                     −−+ −+− ++− =          ∆                     +++ ++++ +          ∆                     ++ +++ +          ∆                     + ++ gmmmn mxmmn v u nnxnnxxmm nnxnnxxmmk v u nnxxmm nntxxmmc v u nnmm nnmmm pt ppp p pp t vk ppp p pptpt t uk t t r vk t vktvv t vkttpt uk t uktuu t ukttptst t t r vv t vkttpt uu t ukttptst t t r vk t vkpt uk t ukptst                             θδθθδθθδ θδθθθθθ θδθθδθθδ θδθθθθθ cossin2cos sincossin sincos2sin cossincos 0 00 00 000 200 020 000 00 00 000 2 2 2 2 '''2 '''2 ' ' (14d) equations of motion of the system can be reduced into classical 2d-pendulum system with moving pivot point and the results are the same with newton’s motion law as presented by eq. (15a)-(15b), ( ) ( ) xptpt fmxmm =−++ θθϕθθ sincoscos 2 (15a) .0sincos =++ θθθ     gxt (15b) the damping matrix is assumed proportional to the combination of mass and stiffness matrices. under this assumption, the rayleigh damping theory is therefore used. the damping matrices can be written as, [ ] [ ] [ ]totaltotalst kbmac += (16a) the proportionality factors is calculated by using damping ratio 21 ζζζ == and natural frequency 1ω and 2ω . , 1 2 21 21       + =       ωω ωω ζ b a (16b) c. remarks on the equations of motion equation (14) calls for some remarks: 1. the term, xf is input force or driving force for the carriage motion while ( )pt mm + is mass total from carriage and payload. this term is an equivalent lumped mass which will be moving load in the portal framework. position of the lumped mass is time-variant as reported in [8]. 2. equations (14a) (14d) are equations of motion which represent the coupling between the dynamics of portal framework and payload pendulum. equation (14a) presents dynamics of carriage motion with the driving force, while eqs. (14b) (14c) are dynamics of payload and dynamics of hoist cable, respectively. 3. carriage acceleration ( )tx appears as forcing term to the dynamics of payload pendulum as shown in eqs. (14b) (14c) if the carriage motion is prescribed. 4. there are contributions of axial and vertical acceleration of portal framework on the dynamics of payload pendulum. these contributions provide elastic moving support for the carriage carrying a payload pendulum. 5. there are effects of coriolis and centrifugal forces in eq. (14a) due to ( )pt mm + moves on deformed portal framework. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 95-104, 2011 p-issn 2087-3379 101 6. equations (14a) (14d) have led to a system of equations which dynamics of payload pendulum are dependent on the dynamics of portal framework and conversely. the dependency is a bidirectional coupling, where elastic support of the payload pendulum motion offered by vibration of portal framework. this result is also found by [3] and [5]. iii. numerical approach in the condition where the dynamics of payload pendulum and hoist cable are not introduced, the swing angle θ and hoist cable displacement δ on the right side of equation eqs. (14a)-(14d) will be zero, the case would be moving load in portal framework, which is imposed by ( )pt mm + load. in order to solve those equations, the computational scheme under newmarkβ and fourth-order runge-kutta method is proposed. the portal framework displacements are calculated by newmarkβ method. the two parameters are selected as β =0.25 and γ =0.5, which implies a constant average acceleration with unconditional numerical stability, while swing angle of payload pendulum are calculated by fourth-order rungekutta method. for each integration step, newmarkβ and runge-kutta methods are combined simultaneously to obtain the portal framework and the payload responses. the computational procedures with a time step of t∆ that performs the direct numerical integration can be summarized as follows: 1. set initial condition for velocity and acceleration: { } ( ){ }00 == tqq ,{ } ( ){ }00 == tqq  (17) 2. the initial external force vector { } ( ){ }00 == tff is calculated using right side of eq. (8) by using initial conditions ( θθθ ,, , ϕϕϕ ,, and δδδ ,, ) of payload. 3. the initial acceleration vector is calculated as: { } [ ] { } [ ]{ } [ ]{ }{ }000 1 0 qkqcfmq ststtotal −−= −  (18) 4. evaluation of constants from a0 to a7 .the parameters ai are show in table 1. table 1. newmark’s parameters. 20 1 t a ∆ = β t a ∆ = β γ 1 t a ∆ = β 1 2 1 2 1 3 −= β a 14 −= β γ a        − ∆ = 2 25 β γt a ( )γ−∆= 16 ta ta ∆= γ7 5. the effective stiffness matrix { }k is calculated as follows. { } [ ] [ ] [ ]st1total0st camakk ++= (19) 6. for each time step: equations (6a)-(6c) are solved to obtain θθθ ,, , ϕϕϕ ,, and δδδ ,, using fourth-order runge-kutta and external force vector { } ttf ∆+ is then updated. the force vector { } ttf ∆+ denotes the external loads of the system at time tt ∆+ . equation of motion of the system is represented as below. [ ]{ } { } tttt fqk ∆+∆+ = (20) the effective load vector { }f is below. { } { } [ ] { } { } { }( )ttttotaltttt qaqaqamff  320 +++= ∆+∆+ (21) the displacement, velocity and acceleration responses are computed with satisfying the following relationships. { } [ ] { } tttt fkq ∆+ − ∆+ = 1 (22) { } { } { }( ) { } { }ttttttt qaqaqqaq  320 −−−= ∆+∆+ (23) { } { } { } { } tttttt qaqaqq ∆+∆+ ++=  76 (24) iv. numerical simulations the cross-section of portal framework is uniform, isotropic and homogeneous material properties. the gravitational acceleration is g = 9.81 m/s2 and time interval is δt = 0.005 s. portal mathematical modeling of a moving planar payload pendulum on flexible portal framework (edwar yazid) jmev 02 (2011) 95-104 102 framework is discretized into 20 beam elements: 10 elements for the top beam, the left side-beam have 2 members with 10 identical elements and so does the right-side beam. the issue of total number of elements and nodes will not be treated as a parameter that will be varied in the simulations. a. moving load case in this subsection, as a test for the mathematical model in eq. (14), simulations are performed under moving load with constant velocity by setting up the swing angle and hoist cable displacement θ = δ = 0. it is noted that the simulation is conducted to primarily attempt to verify the developed computer program in tackling moving load case in portal framework. the dimensions for portal are shown in table 2. the portal framework is subjected to a load moving from the left end to the right end of the top beam with constant velocity v= 0.75 m/s, m = 60 kg. dynamic responses in the axial (x) and vertical (y) displacements of central point cp of the top beam induced by moving force, moving mass are shown in fig. 2. agreement in fluctuating features of the associated curve among moving mass, moving table 2. portal framework dimensions. properties values top beam support top beam young’s modulus, e 2.10e11 kg/m2 density, ρ 7860 kg/m3 cross-section area, a 3.45e-2 m2 1.51e-2 m2 span of framework, bl 12 m framework height, fh 10.6 m force obtained from present code under matlab® and ansys® are found. in those figures, it is also seen that besides the vertical responses, moving loads have significant effect in axial response compared to their corresponding static responses. b. test for the mathematical model after verification of the developed computer program, the equations of motion of the system in eq. (14) are tested under some types of driving forces. the parameters of the overall system are still exactly the same as those in the table 2 and table 3. it is noted that that there is no damping either in dynamics of crane framework or payload, unless particularly stated. this is expected to avoid the effect of structural damping in dynamics of payload and make it a direct comparison with the pendulum model. the carriage is moved by bang-bang input force as driving force. the amplitude and time switch of driving force are varied to generate different velocity level of carriage as depicted in fig. 3. it is noted that that other forms of driving table 3. payload pendulum parameters. parameters values carriage mass, tm 50 kg payload mass, pm 120 kg cable length, p 1 m stiffness cable, k 2.5e5 n/ m initial angle, 00 θθθ  ,,o 5°, 0, 0 initial angle, ooo ,, ϕϕϕ  5°, 0, 0 initial cable displacement ooo ,, δδδ  static, 0, 0 (a) (b) figure 2. displacements of the central point cp of the top beam, (a) axial, (b) vertical. 0 2 4 6 8 10 12 -1.5 -1 -0.5 0 0.5 1 1.5 x 10 -5 moving load position (m) a xi al d is pl ac em en t (m ) moving mass (present code) moving force (present code) ansys static 0 2 4 6 8 10 12 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 x 10 -5 moving load position (m) v er tic al d is pl ac em en t (m ) moving mass (present code) moving force (present code) ansys static journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 vol. 02, no 2, pp 95-104, 2011 p-issn 2087-3379 103 figure 3. time histories of carriage driving force and position with (—)1st driving force, (— —) 2nd driving force, (-) 3rd driving force. (a) carriage driving force, (b) carriage position. figure 4. time history of θ with (—) flexible model, (-) rigid model. (a) 1st driving force, (b) 2nd driving force, (c) 3rd driving force. force could have been chosen, but here an arbitrary form is chosen to primarily attempt to model the real driving force situation for the actual crane system. as a benchmark, rigid model of the system is used. rigid model means that the members of portal framework and hoist cable are rigid and equivalent with classical pendulum with moving pivot point. by observing fig. 4, it can be seen that flexible model have longer periods or lower frequencies than the rigid model. the figure depicts that flexibleθ and rigidθ have a phase shift over the entire cycles of prescribed time duration. the phase shift must be caused by the contribution of flexibility of the portal framework and hoist cable by providing acceleration in two directions to the pivot point of payload pendulum as shown in equations (14a) (14d). it also may be observed that magnitude of swing angle of payload pendulum of flexible model is smaller than the rigid one, which is similar with work [1] and [10]. the rigid and flexible model deviation θ∆ is shown in fig. 5, where rigidflexible θθθ −=∆ . the deviation between the rigid assumption and the flexible model results is clearly observed. the faster the carriage moves, the bigger θ∆ is. further, fig. 5 shows a beating phenomenon in the time histories of θ∆ . the beating phenomenon appears in θ∆ plot because of the superimposed plot of the rigid and flexible response. the deviation between rigid and figure 5. time history of θ∆ with (—) flexible model, (-) rigid model. (a) 1st driving force, (b) 2nd driving force, (c) 3rd driving force. flexible model is also pronounced by spectral analysis in table 4 and their statistical properties in table 5. table 4 confirms that swing angles frequency of flexible model is lower than that of the rigid model. this is expected since the rigid model is stiffer than the flexible model. that is why the stiffer model vibrates at a higher frequency. it is noted that the linear natural frequency for swing angles of rigid model are consistent with the frequency obtained from eqs. (15a)-(15b). 0 5 10 15 20 25 -500 0 500 c ar ria ge d riv in g fo rc e (n ) 0 5 10 15 20 25 0 5 10 15 c ar ria ge p os iti on ( m ) time(s) 0 5 10 15 20 25 -20 0 20 time(s) θ (d eg ) 0 5 10 15 20 25 -20 0 20 time(s) θ (d eg ) 0 5 10 15 20 25 -20 0 20 θ (d eg ) time(s) 0 5 10 15 20 25 -50 0 50 time(s) ∆ θ( de g) 0 5 10 15 20 25 -20 0 20 time(s) ∆ θ( de g) 0 5 10 15 20 25 -20 0 20 time(s) ∆ θ( de g) (a) (b) (c) (a) (b) (a) (b) (c) mathematical modeling of a moving planar payload pendulum on flexible portal framework (edwar yazid) jmev 02 (2011) 95-104 104 table 4. spectral analysis. model dominant frequency of θ (hz) 1st driving force 2nd driving force 3rd driving force rigid 5.38 4.7 4.2 flexible 2.92 2.7 2.2 table 5. statistics of θ. statistics 1 st driving force 2nd driving force 3rd driving force mean * –1.1•10-3 * –3.19•10-4 * –4.56•10-4 ¤ –1.3•10-3 ¤ 4.5•10-4 ¤ 6.37•10-4 skewness * 4.4•10-2 * 2.82•10-2 * 1.06•10-1 ¤ 3.66•10-2 ¤ 4.4•10-2 ¤ 6.45•10-2 kurtosis * 1.816 * 1.644 * 1.273 ¤ 1.751 ¤ 1.657 ¤ 1.357 * rigid model, ¤ flexible model. v. conclusion by applying lagrange’s approach in conjunction with finite element method, equations of motion of a moving planar payload pendulum on flexible portal framework have been derived. the equations show that the payload behaves as a pendulum system with moving flexible support which undergoes accelerations in two directions. there is nonlinear coupling between payload pendulum and portal framework. if the flexibility of cable and portal frame are not accounted, then the equations of motion are greatly simplified as classical pendulum with moving pivot point the results are the same with newton’s motion law. the effects of elasticity in hoist cable and portal framework on the dynamics of a moving planar payload pendulum have been investigated. it has been shown that the vibration amplitudes and frequencies are significantly affected. this paper also recommends that flexibility either structural members or hoist cable must be included in the mathematical model for vibration control design. references [1] r. hui-li, et al. “dynamic response analysis of a moored ship-crane with a flexible boom,” journal of zhejiang university science a, volume 9, issue 1, pp. 26-31, 2008. [2] g. sun and j. liu, “dynamic responses of hydraulic crane during luffing motion,” mechanism and machine theory, volume 41, issue 11, pp. 1273-1288, november 2006. [3] d.c.d. oguamanam and j.s. hansen, “dynamics of a three-dimensional overhead crane system,” journal of sound and vibration, volume 242, issue 3, pp. 411-442, may 2001. [4] jerman, b., podrzaj, p., and kramar, j., “an investigation of slewing-crane dynamics during slewing motion-development and verification of a mathematical model,” international journal of mechanical sciences, volume 46, issue 5, pp. 729-750, 2004. [5] w. yang, et al., “modeling of system dynamics of a slewing flexible beam with moving payload pendulum,” mechanics research communications, volume 34, issue 3, pp. 260–266, 2007. [6] j.j. wu, “transverse and longitudinal vibrations of a frame structure due to a moving trolley and the hoisted object using moving finite element,” international journal of mechanical sciences, volume 50, issue 4, pp. 613-625, april 2008. [7] f. ju, y.s. choo, and f.s. cui, “dynamic response of a tower crane induced by the pendulum motion of the payload,” international journal of solids and structures, volume 43, issue 2, pp. 376-389, january 2006. [8] j.j. wu, “dynamic responses of a threedimensional framework due to a moving carriage hoisting a swinging object,” international journal for numerical methods in engineering, volume 59, issue 13, pp. 1679-1702, april 2004. [9] ziyad n. masoud, “effect of hoisting cable elasticity on anti-sway controllers of quayside container cranes,” nonlinear dynamic, volume 58, numbers 1-2, pp. 129-140, 2009. [10] e. yazid, et al. “vibration analysis of flexible gantry crane system subjected swinging motion of payload,” journal of applied sciences, volume 11, issue 10, pp. 1707-1715, 2011. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.php/ mev/login need a username/password? go to registration at: http://mevjournal.com/index.php/ mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nc-licensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 editor-in-chief prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 deputy editors tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia mechanical engineering managing editors, central office kadek heri sanjaya, ph.d research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia industrial engineering dian andriani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia industrial engineering rifa rahmayanti, m.sc research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia robotics and mechatronics managing editor, asia pacific region aam muharam, m.t. asem, interdisciplinary graduate school of engineering kyushu university fukuoka, japan yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, republic of corea managing editor, europe region naili huda, m.eng.sc. warwick university coventry cv4 7al, united kingdom roni permana saputra, m.eng dyson school of design engineering robot intelligence lab imperial college, london, united kingdom editors aditya sukma nugraha, m.t. mechanical engineering agus risdiyanto, m.t. electrical engineering amin, m.t. electrical engineering arief a firdaus, s.i.kom. communication science arini wresta, m.eng. chemical engineering dr. edwar yazid dynamics and control system erie martides, m.t. material engineering hendri maja saputra, m.t. mechatronics and robotics midriem mirdanies, m.t. computer engineering muhammad kasim, m.renen electrical engineering nur rohmah, m.t. chemical engineering qidun maulana binu soesanto, m.t. mechanical engineering rakhmad indra pramana, m.t. mechanical and material engineering sapdo utomo, m.t. mechatronics and robotics vita susanti, s.kom computer science yayat ruhiyat, a.md. electrical engineering web admin dadan r saleh, m.t. informatics engineering secretariat andri j purwanto, s.t. mechanical engineering graphic designer yukhi mustaqim kusuma sya’bana, s.sn. graphic design journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 © 2017 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, five papers are published with the total number of 45 pages. the authors came from indonesia, united kingdom, australia, and south korea. one paper is related to mechatronics which addresses an experimental review of distance sensors for indoor mapping. another paper presents a preliminary study of biomechatronics for vehicular technology development. three papers fall in the electrical power topic. the first paper deals with an optimization of hybrid smes and ces using cuckoo search algorithm for frequency stability improvement in a micro hydro power plant. the second paper investigates the performance of surface barrier discharge in magnetic field using a series resonance converter. the converter is used as a high voltage plasma generator, where the voltage is 5 kv with the frequency of 25 khz. the third paper reports impacts of a biofuel use on a gas turbine operating performance. the experiments were conducted using a gas turbine with the capacity of 18 mw. since the first volume, our journal provides discretion in financial term by waiving the article processing charge. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2017 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 ii list of contents simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study yukhi mustaqim kusuma sya’bana, kadek heri sanjaya, muhammad redho kurnia, james shippen .............................................................................................................................. 70-75 frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm muhammad ruswandi djalal, herlambang setiadi, andi imran .............................................. 76-84 experimental review of distance sensors for indoor mapping midriem mirdanies, roni permana saputra ............................................................................... 85-94 the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter fri murdiya, febrizal, amun amri ........................................................................................... 95-102 the impacts of a biofuel use on the gas turbine operating performance irhan febijanto ......................................................................................................................... 103-114 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 08, issue 2, december 2017 abstracts sheet e-issn: 2088-6985 date of issues: 28 december 2017 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. yukhi mustaqim kusuma sya’banaa,b,*, kadek heri sanjayab, muhammad redho kurniab, james shippenc (aindustrial design, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, south korea; bresearch centre for electrical power and mechatronics, indonesian institute of sciences jl.cisitu/sangkuriang, bandung 40135, indonesia; cdepartment of mechanical and automotive engineering, coventry university coventry cv1 5fb, uk, united kingdom) simulation of lumbar and neck angle flexion while ingress of paratransit (angkot) in indonesia as a preliminary design study journal of mechatronics, electrical power, and vehicular technology, december 2017, vol. 8, no. 2, p. 70-75, 7 ill, 1 tab, 44 ref. this is the preliminary finding of a study to simulate lumbar and neck flexion while ingress to the paratransit. the result of simulation will determine design aspect criteria as a preliminary step before ideation and implementation design steps. biomechanics of bodies (bob) is software that used to represent passenger task during paratransit ingress simulation, with skeleton model that used is height 165 cm and weight 65 kg. environment to represent this simulation is measured suzuki carry ss 2013 as a private car that has been modified into a public transportation in accordance with the indonesian government road-worthy test. due to the low height of the entrance and the high ground clearance, lumbar and neck joint angle was a focus of this ingress simulation. the peak angle at the neck joint is 40° when 2 s skeleton nod in the door limitation ingress and lumbar flexion is 70° when 5 s skeleton is walking while bend over that will increase the load on that area. based on biomechanical simulation approach, we may suggest the dimension of public transportation design framework developments, especially paratransit. (author) keywords: paratransits ingress; angkot; product design process; biomechanical simulation. muhammad ruswandi djalala,*, herlambang setiadib, andi imranc (adepartment of mechanical engineering state polytechnics of ujung pandang jl. perintis kemerdekaan 7 km. 10, makassar, indonesia; bschool of information technology & electrical engineering the university of queensland, level 4/general purpose south building (building 78) st. lucia campus, brisbane, australia; dept. of electrical engineering, sepuluh nopember institut of technology, jl. raya its, surabaya 60117, indonesia) frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm journal of mechatronics, electrical power, and vehicular technology, december 2017, vol. 8, no. 2, p. 76-84, 13 ill, 6 tab, 22 ref. micro hydro has been chosen because it has advantages both economically, technically and as well as in terms of environmental friendliness. micro hydro is suitable to be used in areas that difficult to be reached by the grid. problems that often occur in the micro hydro system are not the constant rotation of the generator that caused by a change in load demand of the consumer. thus causing frequency fluctuations in the system that can lead to damage both in the plant and in terms of consumer electrical appliances. the appropriate control technology should be taken to support the optimum performance of micro hydro. therefore, this study will discuss a strategy of load frequency control by using energy storage. superconducting magnetic energy storage (smes) and capacitor energy storage (ces) are devices that can store energy in the form of a fast magnetic field in the superconducting coil. for the optimum performance, it is necessary to get the optimum tuning of smes and ces parameters. the artificial intelligence methods, cuckoo search algorithm (csa) are used to obtain the optimum parameters in the micro hydro system. the simulation results show that the application of the csa that use to tune the parameters of hybrid smes-ces-pid can reduce overshoot oscillation of frequency response in micro hydro power plant. (author) keywords: micro hydro; superconducting magnetic-capacitive energy storage; cuckoo; overshoot. midriem mirdaniesa,*, roni permana saputraa,b (research centre for electrical power and mechatronics, indonesian institute of sciences komp. lipi bandung, jl. sangkuriang, gd. 20, lt. 2, bandung 40135, indonesia; bdyson school of design engineering, imperial college london, 10 princes gardens, south kensington, london, uk) experimental review of distance sensors for indoor mapping journal of mechatronics, electrical power, and vehicular technology, december 2017, vol. 8, no. 2, p. 85-94, 15 ill, 13 tab, 11 ref. one of the most important required ability of a mobile robot is perception. an autonomous mobile robot has to be able to gather information from the environment and use it for supporting the accomplishing task. one kind of sensor that essential for this process is distance sensor. this sensor can be used for obtaining the distance of any objects surrounding the robot and utilize the information for localizing, mapping, avoiding obstacles or collisions and many others. in this paper, some of the distance sensor, including kinect, hokuyo utm-30lx, and rplidar were observed experimentally. strengths and weaknesses of each sensor were reviewed so that it can be used as a reference for selecting a suitable sensor for any particular application. a software application has been developed in c programming language as a platform for gathering information for all tested sensors. according to the journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv experiment results, it showed that hokuyo utm-30lx results in random normally distributed error on measuring distance with average error 21.94 mm and variance 32.11. on the other hand, error measurement resulted by kinect and rplidar strongly depended on measured distance of the object from the sensors, while measurement error resulted by kinect had a negative correlation with the measured distance and the error resulted by rplidar sensor had a positive correlation with the measured distance. the performance of these three sensors for detecting a transparent object shows that the kinect sensors can detect the transparent object on its effective range measurement, hokuyo utm-30lx can detect the transparent object in the distance more than equal to 200 mm, and the rplidar sensor cannot detect the transparent object at all tested distance. lastly, the experiment shows that the hokuyo utm-30lx has the fastest processing time significantly, and the rplidar has the slowest processing time significantly, while the processing time of kinect sensor was in between. these processing times were not significantly affected by various tested distance measurement. (author) keywords: distance sensors; kinect; hokuyo utm-30lx; rplidar; indoor mapping; autonomous mobile robot; c programming. fri murdiyaa,*, febrizala, amun amrib (adepartment of electrical engineering, faculty of engineering, universitas riau jl. h.r suaranya km. 12,5 kampus binawidya simpang baru panam, pekanbaru, riau, indonesia; bdepartment of chemical engineering, faculty of engineering, universitas riau jl. h.r suaranya km. 12,5 kampus binawidya simpang baru panam, pekanbaru, riau, indonesia) the performance of surface barrier discharge in magnetic field driven by half bridge series resonance converter journal of mechatronics, electrical power, and vehicular technology, december 2017, vol. 8, no. 2, p. 95-102, 11 ill, 1 tab, 19 ref. this paper reports an application of a series resonance converter as a high voltage generator to drive a surface barrier discharge with a magnetic field. the high voltage was about 5 kv with the frequency of 25 khz. it was connected to circular aluminum plates as the anode electrode and a rectangular aluminum plate as the cathode electrode. these electrodes were separated by a glass dielectric as the barrier. the experiment result indicated that the discharge current with magnetic field was lower than without magnetic field. the plasma on the surface barrier with magnetic field was more luminous than without magnetic field. it also indicated that the area of lissajous diagram for the surface barrier discharge with magnetic field was slightly decreased than without magnetic field. it could be concluded that the magnetic field affects the plasma progress on the surface barrier. molecular dynamic (md) could be used in understanding the ionization process of air molecules. the ionization energies for co2, n2, and o2 were 0.0502 kcal/mol, 0.0526 kcal/mol and 0.430 kcal/mol, respectively in 1,000 seconds. the highest ionization energy was o2. (author) keywords: surface barrier discharge; magnetic field; series resonance converter; molecular dynamic; ionization energy. irhan febijanto (centre for technology of energy resources development, deputy for technology of informatic, energy and mineralbppt, cluster 5 of energy building, puspiptek, tangerang selatan 15314) the impacts of a biofuel use on the gas turbine operating performance journal of mechatronics, electrical power, and vehicular technology, december 2017, vol. 8, no. 2, p. 103-114, 16 ill, 13 tab, 20 ref. the use of pure plant oil (ppo) as a fuel blend in a power plant is mandatory as stipulated in the ministerial decree of energy and mineral resource of the republic of indonesia. however, the implementation of ppo used in power generation has many obstacles due to a lack of information concerning the impacts of ppo used in the operating performance of the power generation engine. in this study, the effect of ppo as a blended fuel with highspeed diesel (hsd) was studied by using the gas turbine with a capacity of 18 mw. the ppo was blended based on volume with a ratio of 0%, 5%, 10% and 20%. as the results, it is shown that the use of ppo with a blend ratio of 20% is the maximum fuel blend ratio according to the threshold value of a flue gas temperature and a vibration velocity in the gas turbine. (author) keywords: gas turbine power plant; pure plant oil; high-speed diesel; blended fuel. microsoft word vol02_no2 issn 2087-3379 (cetak) issn 2088-6985 (online) journal of mechatronics, electrical power and vehicular technology volume 02, nomor 2, desember 2011 insured editor kepala pusat penelitian tenaga listrik dan mekatronik lipi editor-in-chief dr.eng. estiko rijanto (mechatronics and control systems) managing editor tinton dwi atmaja, m.t. (informatics and electrical engineering) editors ghalya pikra, mt. (mechanical engineering) noviadi arief rachman, mt. (electrical engineering) aam muharam, mt. (electronics engineering) copy editor naili huda, m.eng.sc. (industrial engineering) advisory editor rachmini saparita, phd. (interdisciplinary engineering) peer reviwer / mitra bestari prof.dr. suhono harso supangkat (electrical engineering; itb) dr.-ing. moch ichwan (vehicular technology; lipi) dr. yuliadi erdani (informatics engineering; politeknik manufaktur) dr.eng. budi prawara (material engineering; lipi) ir. edi leksono, m.eng., phd. (electrical engineering; itb) ir. arko djajadi, ph.d. (mechatronics; swiss german university) riza muhida, ph.d (mechatronics engineering; stkip surya) web admin dadan ridwan saleh, m.t. secretariat merry indahsari devi, s.t. vita susanti, s.kom. graphic designer m. redho kurnia, s.sn. jurnal ini tebit dua kali dalam satu tahun journal of mechatronics, electrical power and vehicular technology adalah jurnal ilmiah yang diterbitkan oleh pusat penelitian tenaga listrik dan mekatronik lembaga ilmu pengetahuan indonesia (lipi). jurnal ini memuat karya ilmiah yang berupa tulisan hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi, dan aplikasi perekayasaannya. alamat redaksi sekretariat jurnal pusat penelitian tenaga listrik dan mekatronik lipi komp lipi jl. sangkuriang, gedung 20, lantai 2, ruang 209 bandung, jawa barat, 40135 indonesia telp: 022-2503055/2504770 fax: 022-2504773 e-mail: sekretariat@mevjournal.com www.telimek.lipi.go.id/jurnal-jmev.htm www.mevjournal.com issn 2087-3379 (cetak) issn 2087-3379 (online) i journal of mechatronics, electrical power and vehicular technology volume 02, nomor 2, desember 2011 kata pengantar dewan editor puji dan syukur kami panjatkan kepada tuhan yang maha esa, atas berkat dan karunia-nya kami dapat mempublikasikan journal of mechatronics, electrical power, and vehicular technology (jmev) volume 2, nomor 2, tahun 2011 ini. atas nama dewan editor kami mengucapkan terimakasih atas kerjasama dan kontribusi berbagai pihak yang telah membantu terbitnya jurnal ini. berdasarkan surve yang pernah kami lakukan, pada saat ini di indonesia telah banyak jurnal ilmiah dipublikasikan. namun banyak masukan menyatakan jumlah jurnal aplikasi teknik sangat kurang, dan belum ada jurnal yang secara spesifik memuat bidang keilmuan dan teknologi terkait dengan mekatronik, tenaga listrik, dan teknologi kendaraan. oleh karena itu, hadirnya jurnal ini diharapkan dapat menjadi media publikasi bagi para penggiat iptek dan industri terkait dengan mekatronik, tenaga listrik dan teknologi kendaraan. keberadaan jmev merupakan buah ketekunan semangat membangun pada level nasional sejak diselenggarakannya seminar nasional mekatronik tahun 2006 oleh lipi karena beberapa mitra bestari jmev juga pernah menjadi reviewer makalah seminar nasional mekatronik tersebut. sejak dirintis jurnal ini pada tahun 2010 sampai akhir tahun 2011 telah diterbitkan jmev empat kali dengan dua kali terbitan per tahun. tahun 2010 dan 2011 merupakan tahap perjuangan pembangunan jmev dengan target menerbitkan makalah-makalah yang representatif dan bermutu pada level nasional. sasaran tahap ini adalah jmev dapat diakreditasi pada awal tahun 2012. dalam empat kali penerbitan selama dua tahun ini telah diterbitkan makalah-makalah dari lipi, bppt, itb, swiss german university, politeknik manufaktur, dan stkip surya serta dari beberapa universitas di malaysia. khususnya pada jmev edisi vol.2 no.2 tahun 2011 ini dimuat 7 makalah yang telah melalui seleksi penilaian berjenjang oleh editor pelaksana, editor ahli dan mitra bestari sesuai dengan prosedur standar operasi yang ada. tiga makalah berbahasa inggris dan empat berbahasa indonesia. topik yang dimuat terkait: mathematical model of pendulum on flexible portal, rapid pcb prototyping, fuzzy intelligent water sprinkle system, perangkat lunak open source pada mesin milling cnc, kendali motor dc brushless untuk platform robot, parabolic trough solar collector, dan pembangkit listrik biogas. kami mengucapkan selamat membaca dan semoga publikasi ini memberikan sumbangsih bagi kemajuan iptek nasional pada khususnya dan kemajuan bangsa pada umumnya.. bandung, 21 desember 2011 dewan editor issn 2087-3379 (cetak) issn 2088-6985 (online) ii journal of mechatronics, electrical power and vehicular technology volume 02, nomor 2, desember 2011 daftar isi uji coba awal parabolic trough solar collector ghalya pikra, agus salim, andri joko purwanto, zaidan eddy 57-64 solar-based fuzzy intelligent water sprinkle system riza muhida, momoh jimoh e. salami, winda astuti, nurul amalina bt ahmad kasim, nani rahayu 65-72 kajian biogas sebagai sumber pembangkit tenaga listrik di pesantren saung balong albarokah, majalengka, jawa barat maulana arifin, aep saepudin, arifin santosa 73-78 machine vision implementation in rapid pcb prototyping yosafat surya murijanto, rusman rusyadi, maralo sinaga 79-84 perancangan dan pengujian awal kendali motor dc brushless untuk independent 4-wheel drive platform robot rev-11 roni permana saputra, rizqi andry ardiansyah, midriem mirdanies, arif santoso, aditya sukma nugraha, anwar muqorobin, hendri maja saputra, vita susanti, estiko rijanto 85-94 mathematical modeling of a moving planar payload pendulum on flexible portal framework edwar yazid 95-104 penggunaan perangkat lunak open source untuk sistem open architecture pada mesin milling cnc dalmasius ganjar subagio, tinton dwi atmaja 105-112 mev j. mechatron. electr. power veh. technol 07 (2016) 57-66 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.57-66. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. optimized object tracking technique using kalman filter liana ellen taylor a,*, midriem mirdanies b, roni permana saputra b aschool of engineering and information technology university of new south wales (unsw) canberra, act 2600, australia bresearch center for electrical power and mechatronics, indonesian institute of sciences (lipi) komplek lipi bandung, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia received 25 february 2016; received in revised form 09 may 2016; accepted 12 may 2016 published online 29 july 2016 abstract this paper focused on the design of an optimized object tracking technique which would minimize the processing time required in the object detection process while maintaining accuracy in detecting the desired moving object in a cluttered scene. a kalman filter based cropped image is used for the image detection process as the processing time is significantly less to detect the object when a search window is used that is smaller than the entire video frame. this technique was tested with various sizes of the window in the cropping process. matlab® was used to design and test the proposed method. this paper found that using a cropped image with 2.16 multiplied by the largest dimension of the object resulted in significantly faster processing time while still providing a high success rate of detection and a detected center of the object that was reasonably close to the actual center. keywords: kalman filter; object tracking; object detection; cropping; color segmentation. i. introduction in the recent decades, the use of computer vision in many applications has been significantly increased from manufacturing application into military applications [1-3]. a major aspect of computer vision applications is vision based object tracking. tracking objects in the real time environment is not a trivial task and has been a popular research topic in the computer vision field. a robust vision tracking system allows for many applications such as traffic monitoring, autonomous system guidance, surveillance systems, human computer interaction, vehicle navigation, and automated weapons systems [2, 4, 5]. various algorithms and methods have been developed for object detection based on the object’s color, feature points or other. methods based on feature point detection have been carried out by bing, using speeded up robust feature (surf) tracker [6] and fazli, using scale invariant transform feature (sift) tracker [7]. in previous research, modification of sift and surf methods has been performed to detect multiple objects at once [2]. these methods are accurate but require higher processing time. methods based on color have been researched by comaniciu using mean-shift [8] and wang using color distribution [9]. these methods require less processing time but the accuracy is limited. for object detection, a fundamental feature is the robustness and resistance to changes in the scene image, such as different lighting conditions and blurriness of the object due to rapid movement [5]. another feature that is crucial to object tracking implementation, especially for real-time applications, is computational time. to be feasibly implemented in a real-time process, such as for robotic sensor application, the object detection process has to be implemented efficiently so that is may run fast. even though the detection process is relatively fast, the system must still maintain its performance in terms of success rate, accuracy, and repeatability of the detection process. in this research, an algorithm of fast and accurate visual object tracking is presented. the algorithm is designed to improve object-tracking * corresponding author. tel: +61-439621755 e-mail: lianat36@gmail.com http://dx.doi.org/10.14203/j.mev.2016.v7.57-66 l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 58 process by minimizing the processing time required while maintaining accuracy in detecting the desired object in a cluttered scene. in this approach, a combination of kalman filter estimation technique and color segmentation based object recognition is used. parameters of the process were varied to determine the relationship between each parameter and the performances of the object tracking process. based on the experimental results, the optimum set of parameters can then be determined to obtain the desired performance of the object tracking process. the research was undertaken at the mechatronics lab. research center for electrical power and mechatronics indonesian institute of sciences (lipi). ii. methodology a. color based object detection from the video the method used for object recognition in this paper was detection of the object based on color segmentation. the advantage of using color segmentation detection was that it could support blurred images of the object. blurred images of the object are common when an object is moving rapidly in a video, which was needed to test the kalman filter. the objects used in this experiment have red as their dominated color. each object was detected from a frame acquired from a video in rgb format. the red layer of the video frame was extracted and a gray scale of the frame was subtracted from the red frame. noise was filtered out by a median filter. a binary image was then formed with a red threshold of 0.25 to obtain a binary image containing ‘binary large objects’ (blob). since the objects detected in this experiment have red dominate color, the largest blob resulting from the described process would be the object. based on this largest detected blob, the bounding box then can be obtained and used to acquire the center location of the object. the step-by-step object detection process in this method can be seen in the figure 1. this method can also be used to detect and track another object with different color by adjusting the threshold on color segmentation process. b. kalman filter based estimation kalman filter is one of the most common approaches for estimating linear state that is assumed to have a gaussian distribution [10]. this technique is published first by r.e. kalman, in 1960 as a recursive solution for linear filtering in discrete data [11]. the kalman filter is an efficient recursive process that provides estimation of the states at the past, present, and future time domain. it also estimates the state while the model and the nature of the system is not known precisely [12]. 1) basic kalman filter operation in general, the operation of discrete time kalman filtering has the form that can be seen in figure 2. there are two main operations, the prediction step and correction step. this operation form is similar to feedback control where at filter estimates the state in the prediction step, and then obtains feedback in the correction step based on the measurement result [12]. the prediction step in this process is responsible for predicting the states to obtain a priori estimation of the next step based on the projection of the current state. meanwhile, the correction step in this process will improve the a priori estimation resulting in the prediction step, based on obtained measurement results and obtains a posteriori estimation. for discrete time systems, these two operations are expressed using the notations as shows in figure 2. (a) (b) (c) (d) figure 1. step-by-step object detection based on color segmentation (a) original rgb image; (b) gray scale of the image subtracted from the red layer; (c) binary image with pixels above the red threshold of 0.25 converted to white; (d) after blob analysis of image, a red box is drawn around the box with the center indicated figure 2. basic operation of the kalman filter l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 59 • x�(k + 1|k)  state estimation at time k+1 predicted based on the parameter at time k • p (k + 1|k) covariance of the estimated state at time k+1. • x�(k|k) state estimation at time k updated based on the observation process or measurement at time k. • p(k|k)covariance of the estimated state at time k. 2) prediction step the mathematical expression for this ‘time update’ step can be seen in the eq. (1) and 2 [13]. in these equations, the future state (x�(k + 1|k)) is predicted based on the process model 𝐅 and the current state (x�(k|k)). the prediction covariance ( p(k + 1|k) ) is also calculated based on the process model f and the uncertainty of the process model (q(k)). x�(k + 1|k) = fx�(k|k) (1) 𝑃(k + 1|k) = fp(k|k)ft + q(k) (2) 3) correction step the next operation in the kalman filter is the correction step, also known as the ‘measurement update’ step. in this step, the predicted state is corrected based on the difference between the real measured result and the expected measurement result (z�k+1) from the measurement model (h). equation 3 shows the mathematical expression of the measurement model [13]. z�k+1 = h x�k+1 (3) once the real measured result is obtained, the difference (𝑣) between the real measurement and the measurement model is calculated in eq. (4). the kalman gain, k, is then calculated to update the estimated state x�k+1|k to become x�k+1|k+1 . the complete calculation of this correction step is expressed in eq. (5) to eq. (7) [13]. vk+1 = zk+1 − z�k+1 (4) kk+1 = pk+1|kht(hpk+1|kht + rk+1|k)−1 (5) x�k+1|k+1 = x�k+1|k + kk+1. vk+1 (6) pk+1|k+1 = (i − kk+1h)pk+1|k − (7) 4) kalman filter for object tracking in object tracking implementation, the kalman filter predicts the object's next position from the previous state information about the object. it then verifies the result of the prediction using the result of the object detection process in the next following step. in this paper, the object was assumed to move with constant velocity. based on this, the motion model for this object tracking can be expressed in eq. (8), while ∆x and ∆y are constant. xk+1 = xk + ∆x yk+1 = yk + ∆y (8) from eq.(8), the motion model can be expressed in the form in eq. (9) from eq. (1). � 𝑥𝑘+1|𝑘 𝑦𝑘+1|𝑘 ∆𝑥𝑘+1 ∆𝑦𝑘+1 � = � 1 0 1 0 0 1 0 1 0 0 0 0 1 0 0 1 �� 𝑥𝑘|𝑘 𝑦𝑘|𝑘 ∆𝑥𝑘 ∆𝑦𝑘 � 𝑭 = � 1 0 1 0 0 1 0 1 0 0 0 0 1 0 0 1 � (9) based on the predicted state, the expected measurement result can be calculated as expressed in eq. (10). z�x(k+1) = xk+1 z�y(k+1) = yk+1 (10) from eq. (10), the measurement model can also be expressed from eq. (3) to become eq. (11). � z�x z�y � = �1 0 0 0 0 1 0 0 �� xk+1|k yk+1|k ∆xk+1 ∆yk+1 � 𝐻 = �1 0 0 0 0 1 0 0 � (11) figure 3 illustrates a summary of the kalman filter process for image tracking implementation. c. proposed object tracking method in this paper, a kalman filter based cropped image method is proposed. figure 4 outlines the process. in this method, object tracking was figure 3. a summary of the kalman filter operation l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 60 implemented such that the object was searched for in a window that was smaller than the entire scene frame. the advantage of this is that it reduces the number of pixels that must be processed and minimizes the likelihood of detecting an object other than the object of interest in a cluttered scene. in addition, this method is also expected to be more robust in scenarios where the object is obstructed from view for several frames. there are four main steps in this method: initialization, kalman filter prediction and image cropping, object detection on the cropped image and kalman filter correction. 1) initialization the object is searched for in the entire image for each frame until it is detected. once the object is detected, the kalman filter is initialized with the object’s detected location. the object’s largest dimension is then used as a reference to determine the search window size for the entire video. the search window is set to be a width and height that is a specified multiple (referred to as the window multiple in this paper) of the object’s largest dimension (i.e. width or height). in this initialization step, some parameters of the kalman filter used in this operation are also configured such as: the motion model of the object, the error model of the prediction and measurement process, and the measurement model and the initial state. 2) kalman filter prediction and image cropping after the initial object location and size are detected and the kalman filter is initialized, then the relative position for the object in the next frame is predicted by the kalman filter. the scene image is then cropped to the search window located at the predicted location obtained as a result of the kalman filter. 3) object detection on the cropped image the object detection process in this method is performed on a smaller cropped image of the whole video frame located at the location obtained from the kalman filter prediction. this approach is used to optimize the computational time of the detecting process while maintaining the accuracy. 4) kalman filter correction if the object is detected, the object’s location is used to correct the state of the kalman filter. this updated location is then used for prediction in the next iteration process. if the object is not detected, previous predicted location will be used for the next predicted location. iii. materials the objects selected for tracking in this experiment consisted of a push button, a cherry ripe bar and a motorbike helmet as shown in figure 5. the objects were of various sizes (listed in table 1) and shapes to determine if the optimal search window size was affected by the object size or shape. a video was shot of each object moving randomly in a scene and was used to provide an analysis of using a cropped image to search for the object in a given frame. the computer used in this experiment is a laptop with figure 4. method for implementing kalman filter based cropped image figure 5. the various objects used for object tracking object 1 object 2 object 3 table 1. object sizes object approximate pixel area (% of frame area) object 1 2.3 object 2 3.8 object 3 0.7 l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 61 the following specifications: intel(r) processor 5y10 cpu @ 1 ghz, 8 gb ram and microsoft windows 1064 bit. the object tracking was coded in matlab 2014b and aimed to compare the accuracy and processing time of object tracking; both with and without image cropping of the scene image based on the object’s previous location. the effect of the size of the cropped image window on accuracy and processing time was also observed. iv. results and discussion various search window sizes were used for testing. when the whole scene frame of the video was used for object detection, the object was detected 100% of the time for all objects. when the object was successfully found in a frame, its detected location was drawn to the video and displayed to the user as shown in (d) of figure 1. each of the objects was successfully detected in all frames once the window multiple was greater than 1 (see figure 6). object 2 approaches a 100% success rate earlier than the other objects as it has a rectangular shape, and the longer width is chosen for the square search window. the processing time of the cropping method was compared to the processing time when searching the whole video frame as shown in table 2. object tracking was repeated 5 times for each window size for each object and the processing time for the 5 trials was averaged. the processing time for object 3 is longer than the other objects due to its smaller pixel area in the frame. figure 7 shows the normalized scale (i.e. scaled from 0 to 1) of processing times of all objects with various search windows sizes. it can be seen that in general, for smaller search windows, the processing time was significantly shortened and it gradually approached the processing time for searching the whole window as the search window size increased. this is expected as the search window size approaches the size of the entire video frame. from figure 7, the normalized scale of average processing time with respect to the different search window sizes can be approximated generally using a polynomial function. in this case, a fifth orders polynomial function is used to relate the search window size ‘ x ’ to average time processing ‘f(x)’and can be expressed in eq. (12). f(x) = a5x5 + a4x4 + a3x3 + a2x2 + a1 + a0 (12) using polynomial curve fitting, “polyfit”, function in matlab 2014b [14], the table 2. average processing times (in seconds) window multiple object 1 object 2 object 3 0.5 56.78 56.68 70.36 1.0 59.63 58.50 68.99 1.5 60.41 60.22 70.70 2.0 61.58 65.55 71.23 2.5 61.72 68.36 73.25 3.0 64.06 67.84 71.99 3.5 65.13 66.92 74.22 4.0 65.53 66.98 75.43 4.5 67.51 68.08 75.64 5.0 69.26 68.80 77.40 5.5 69.31 69.23 78.21 6.0 70.01 68.33 80.87 6.5 70.07 68.76 82.04 7.0 69.87 67.86 82.76 7.5 68.95 68.30 83.75 8.0 69.19 68.81 83.32 8.5 68.20 67.45 81.80 9.0 69.42 67.24 82.67 9.5 68.83 66.84 82.91 full window 69.77 71.70 88.88 figure 6. success rate for tracking objects using various window sizes figure 7. normalized scale of processing time for tracking objects using various window sizes l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 62 approximated coefficients for eq. (12) can be seen in the table 3. when the whole frame was searched, the center of the object was accurately found. when the object was detected in a scene by a smaller search window, the detected location was not always the actual center of the object. this was due to the search window not always encompassing the entire object such as when the search window multiple was less than one or when the object was only partly captured in the search window. figure 8, figure 9, and figure 10 illustrate the tracked object centers for object 1, 2 and 3, respectively, for various search window sizes. it can be seen that the detected location converges to the actual center location of the object as the window multiple increases. the error between the actual object centers and the tracked centers for various search window sizes can be calculated as the euclidean distance ‘ d ’ between two centers ( (x1, y1) and (x2, y2) ). this euclidean distance can be calculated in eq. (13) [15]. d = �(x2 − x1)2 + (y2 − y1)2 (13) the euclidean distance error of the tracking process on all three objects for various search window sizes can be seen in figure 11. as expected, for larger search window sizes the distance error was lower. the average error in each search window size can be seen in table 4. table 3. approximated coefficients for polynomial function in equation 12 coefficient approximated coefficient 𝑎0 -0.2007 𝑎1 0.4672 𝑎2 -0.1370 𝑎3 0.0295 𝑎4 -0.0032 𝑎5 0.0001 table 4. mean distance error (in pixels) window multiple object 1 object 2 object 3 0.5 31.68 68.75 15.31 1.0 15.83 74.11 10.86 1.5 10.71 78.70 9.25 2.0 8.92 69.68 8.56 2.5 7.73 25.58 7.48 3.0 6.45 0.27 7.23 3.5 4.06 0.27 5.10 4.0 3.04 0.27 3.29 4.5 1.48 0.27 2.55 5.0 0.22 0.27 1.81 5.5 0.52 0.27 1.19 6.0 0.52 0.27 0.64 6.5 0.52 0.27 0.18 7.0 0.52 0.27 0 7.5 0.52 0.27 0 8.0 0.52 0.27 0.55 8.5 0.52 0.27 0.55 9.0 0.52 0.27 0.55 9.5 0.52 0.27 0.55 figure 8. difference between the detected and predicted center of object 1 and the actual center for various window sizes l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 63 figure 12 shows the normalized scale of the mean distance error for tracking with various search window sizes. from figure 12, it can be seen that the distance error ‘g(x)’with respect to the search window size ‘x’ can be approximated using an exponential equation as expressed in eq. (14). g(x) = aebx (14) using the exponential curve fitting function on matlab2014b [16], the approximated parameters ‘𝑎’ and ‘𝑏’ for eq. (14) can be seen in table 5. figure 9. difference between the detected and predicted center of object 2 and the actual center for various window sizes figure 10. difference between the detected and predicted center of object 3 and the actual center for various window sizes l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 64 figure 13 illustrates the relationship between the average processing time and mean distance error with respect to various search window sizes based on the approximated general function f(x) and g(x). to optimize the tracking processes, in this case, it can be done by minimizing the processing time while also minimizing the distance error on the process. the mathematical equation of this optimization process can be expressed in eq. (15). argminx∈[0→10]{f(x) + g(x)} (15) the optimum window size for tracking can be found at the intersection point between the distance error curve and the processing time curve. it is when f(x) and g(x) minimal for a certain window size. figure 14 shows that these figure 12. normalized scale of mean distance error of object tracking using various window sizes table 5. approximated parameters for equation 14 coefficient approximated coefficient 𝑎 1.31 𝑏 -0.5457 figure 11. distance error of the tracking process for various search window sizes figure 13. relation between average time processing and mean distance error in different search window sizes figure 14. intersection between distance error curve and time processing curve l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 65 two curves intersect on coordinate (2.16, 0.40). it can be concluded that the optimum window multiple size for this tracking process is 2.16 multiple of the objects largest dimension. v. conclusions using a cropped image at a predicted location for an object in a given frame provided a significant improvement in processing time for object tracking compared to conventional methods, which uses whole image size tobe processed, while still maintaining high accuracy in detecting the object in a scene. the processing time improvement was greater when the window size was smaller. the reduction in processing time was also greater for objects with a smaller pixel area. the window multiple of 1 provided the optimum size as it detected all objects 100% of the time and produced a significant improvement in processing time. certain applications of object tracking may require the center location of the object rather than a location that a part of the object is located in. for these applications, a window multiple larger than 1 for the search window would be required to ensure the search window captured the whole object to determine its center. in this experiment, the process to optimize the search window size choice has been undertaken by minimizing the processing time while also minimizing the distance error. based on the intersection between distance error curve and time processing curve, it has been obtained that the optimum search window size in this case is about 2.16 times of the object length. further research could be undertaken in the future to determine the improvement in accuracy and processing time when using a search window for various other object detection algorithms, such as using surf and shift algorithm. acknowledgement the authors would like to thank australia’s new colombo plan internship program secured by unsw for the opportunity and financial support and all those who have helped in conducting this research. references [1] y. s. murijanto et al., "machine vision implementation in rapid pcb prototyping," journal of mechatronics, electrical power, and vehicular technology, vol. 02, no. 2, pp. 79-84, 2014. [2] m. mirdanies et al., "object recognition system in remote controlled weapon station using sift and surf methods," journal of mechatronics, electrical power, and vehicular technology, pp. 99-108,2013. [3] e. s. ma’arif et al., "a trajectory generation method based on edge detection for auto-sealent cartesian robot," journal of mechatronics, electrical power, and vehicular technology , vol. 05, no. 1, pp. 27-36, 2014. [4] y. hongpeng et al., "a robust object tracking algorithm based on surf and kalman filter," intelligent automation & soft computing, vol. 19, no. 4, pp. 567-579, 2013. [5] m. m. khan et al., "tracking occluded objects using kalman filter and color information," international journal of computer theory and engineering, vol. 6, no. 5, , vol. 6, no. 5, pp. 438-442, 2014. [6] z. bing et al., "research of tracking models based on surf," in pervasive computing signal processing and applications (pcspa), 2010. [7] s. fazli et al., "particle filter based object tracking with sift and color feature," in second international conference on machine vision, 2009. icmv '09. , dubai, 2009. [8] d.a.m. comaniciu, "mean shift: a robust approach toward feature space analysis," in ieee transactions on pattern analysis and machine intelligence, vol. 24, ieee, 2002, pp. 603-619. [9] d. wang et al., "fast and effective colorbased object tracking by boosted color," pattern analysis and applications, vol. 16, no. 4, pp. 647-661, 2013. [10] h. a. patel and d. g. thakore, "moving object tracking using kalman filter," international journal of computer science and mobile computing, vol. 2, no. 4, p. 326 – 332,2013. [11] r. e. kalman, "a new approach to linear filtering and prediction problems," journal of basic engineering, vol. 82, no. 1, p. 35– 45, 1960. [12] g. welch and g. bishop, "an introduction to the kalman filter," 2006. [13] r. p. saputra, "implementation 2d ekf slam for wheeled mobile robot," master thesis, university of new south wales, sydney-australia, 2015. [14] the mathworks, inc., "polyfit," [online]. available: http://au.mathworks.com/help/matlab/ref/po lyfit.html. [accessed 23 02 2016]. l.e. taylor et al. / j. mechatron. electr. power veh. technol 07 (2016) 57-66 66 [15] e. w. weisstein, "distance," [online]. available: http://mathworld.wolfram.com/distance.htm l. [accessed 23 02 2016]. [16] the mathworks, inc., "exponential model," [online]. available: http://au.mathworks.com/help/curvefit/expo nential.html?searchhighlight=exponential% 20model. [accessed 23 02 2016]. i. introduction ii. methodology a. color based object detection from the video since the objects detected in this experiment have red dominate color, the largest blob resulting from the described process would be the object. based on this largest detected blob, the bounding box then can be obtained and used to acquire the center location of the object. the step-by-step object detection process in this method can be seen in the figure 1. this method can also be used to detect and track another object with different color by adjusting the threshold on color segmentation process. b. kalman filter based estimation 1) basic kalman filter operation 2) prediction step 3) correction step 4) kalman filter for object tracking c. proposed object tracking method 1) initialization 2) kalman filter prediction and image cropping 3) object detection on the cropped image 4) kalman filter correction materials iv. results and discussion v. conclusions acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, faculty of engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. dr. estiko rijanto research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135 indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. dr. ir. zainal abidin mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei shi, tokyo, 184 – 8588, japan prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. ir. adi soeprijanto, m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia prof. george anwar, ph.d. university of california, berkeley 101 sproul hall, berkeley, ca 94704, united states prof. dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi prof. dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135 indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan korea, republic of dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr. ir. edi leksono, m.eng. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. endra pitowarno, m.eng. electronics engineering polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies, indonesian institute of sciences widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. agus sunjarianto pamitran, st., m.eng. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. sunit hendrana research center for physics lipi komp lipi jl. sangkuriang, blg 60, 2nd fl, bandung 40135, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia aji prasetya wibawa, ph.d. department of electrical engineering state university of malang jl. semarang no. 5, malang, jawa timur, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electical power and mechatronics-lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering institut teknologi nasional jl. phh. mustafa no. 23, bandung, jawa barat, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. centre for appropriate technology development, indonesian institute of sciences jl. ks. tubun no. 5 subang 41213 indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted.  heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot.  heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot.  heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket  heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket.  heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and postpublication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. lowquality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points:  make sure you use uniform lettering and sizing of your original artwork.  preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier.  number the illustrations according to their sequence in the text.  use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv  eps (or pdf): vector drawings. embed the font or save the text as 'graphics'.  tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi.  tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi.  tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not:  supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low.  supply files that are too low in resolution.  submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]—do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least ten references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows  book: author, title. edition, editor , city, state or country: publisher, year, pages.  part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages.  periodical: author, “title”, journal, volume (issue), pages, month, year.  proceeding: author, “title”, in proceeding, year, pages.  unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year.  paten/standart: author, “title”, patent number, month day, year.  technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows:  book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file.  periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file.  papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file.  reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. mev j. mechatron. electr. power veh. technol 07 (2016) 67-76 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.67-76. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses mohamed milad baiek a, ahmad e. esmaio a, muhammad nizam a,*, miftahul anwar a, hasan m. s. atia b apostgraduate program, mechanical engineering department, sebelas maret university jl. ir. sutami no. 36-a surakarta, indonesia bgeneral electricity company of libya (gecol), gecol building, jamahiriya area 668 tarabulus, tripoli, libya received 01 april 2016; received in revised form 25 april 2016; accepted 03 may 2016 published online 23 december 2016 abstract the purpose of this research is to study optimal size and placement of shunt capacitor in order to minimize line loss. derivative load bus voltage was calculated to determine the sensitive load buses which further being optimum with the placement of shunt capacitor. particle swarm optimization (pso) was demonstrated on the ieee 14 bus power system to find optimum size of shunt capacitor in reducing line loss. the objective function was applied to determine the proper placement of capacitor and get satisfied solutions towards constraints. the simulation was run over matlab under two scenarios namely base case and increasing 100% load. derivative load bus voltage was simulated to determine the most sensitive load bus. pso was carried out to determine the optimum sizing of shunt capacitor at the most sensitive bus. the results have been determined that the most sensitive bus was bus number 14 for the base case and increasing 100% load. the optimum sizing was 8.17 mvar for the base case and 23.98 mvar for increasing load about 100%. line losses were able to reduce approximately 0.98% for the base case and increasing 100% load reduced about 3.16%. the proposed method was also proven as a better result compared with harmony search algorithm (hsa) method. hsa method recorded loss reduction ratio about 0.44% for the base case and 2.67% when the load was increased by 100% while pso calculated loss reduction ratio about 1.12% and 4.02% for the base case and increasing 100% load respectively. the result of this study will support the previous study and it is concluded that pso was successfully able to solve some engineering problems as well as to find a solution in determining shunt capacitor sizing on the power system simply and accurately compared with other evolutionary optimization methods. keywords: particle swarm optimization; shunt capacitor; line losses. i. introduction distribution system planning is an important issue in power engineering. the term distribution system consists of low voltage (lv) and medium voltage (mv) networks. planning of mv network is to identify the location and size of distribution substations and mv feeders. the objective of mv network planning is to minimize the investment cost along with the line loss and reliability indices such as system average interruption duration index (saidi) and system average interruption frequency index (saifi). there are several limitations which should be satisfied during the planning procedure. the bus voltage as a constraint should be maintained within a standard range. the actual feeder current should be less than the rated current of the feeder [1]. the voltage drop along radial distribution systems has been a crucial operating problem. utilities look for solutions for this problem, from both technical and economical standpoints. various devices such as capacitors and voltage regulators (vr’s) can be installed to reduce the voltage drop. * corresponding author.tel: +62 271632163 e-mail: nizam_kh@ieee.org http://dx.doi.org/10.14203/j.mev.2016.v7.67-76 m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 68 several researchers have used soft computing techniques to find an optimal solution for the dc location. a number of these methods used heuristic search methods while some others formulate the problem as a general optimization problem [2–4]. however, the general formulation of this problem is quite complicated necessitating computational demand solutions. an intelligent method based on a hybrid system of pso, honey bees mating optimization (hbmo), and cuckoo search algorithm were proposed to solve the capacitor placement problem [3, 5, 6]. recently, many evolutionary methods such as ga [3, 4], evolutionary programming [7, 8], stochastic [9], pso [6, 7, 10] have been applied to solve the power system economic dispatch problem. generally, evolutionary methods need several trials to achieve optimal or near optimal solution and require special care in the tuning of parameters associated with it. this research will focus on finding optimum placement at the most sensitive bus and proposing optimum sizing using pso to improve the line losses in the ieee 14 bus power system. a mathematical model of derivative function was used to determine the sensitive load buses. further, the range of pso is divided to some localities. the individual minimum and global minimum of the cost function is saved in memory, along with the corresponding particle position (in our case, shunt capacitor position). the particle position is updated in which near the position towards the individual minimum and global minimum, according to pre-specified weights assigned. in this way, the optimum sizing can be achieved. ii. basic theory a. particle swarm optimization particle swarm optimization (pso) is a population-based stochastic optimization technique developed by dr. eberhart and dr. kennedy in 1995, inspired by social behavior of bird flocking or fish schooling. the potential solutions, called particles, fly through the problem space by following the current optimum particles. each particle keeps track of its coordinates in the problem space which is associated with the best solution (fitness) it has achieved so far (the fitness value is also stored). this value is called pbest. another "best" value that is tracked by the particle swarm optimizer is the best value, obtained so far by any particle in the neighbors of the particle. this location is called lbest. when a particle takes all the population as its topological neighbors, the best value is a global best, and this is called gbest. the pso concept consists of, at each time step, changing the velocity (accelerating) of each particle toward its pbest and gbest locations (local version of pso). acceleration is weighted by a random term, with separate random numbers being generated for acceleration toward pbest and lbest locations [6, 7]. the flowchart of the pso algorithm is shown in figure 1. understanding the conceptual basis of the pso, the steps are explained. first, define the solution space to pick the parameters that need to be optimized and give them a reasonable range to search for the optimal solution. this is referred to xminn, and xmaxn respectively, where the range is from 1 to n. second, define a fitness function that provides the link between the optimization algorithm and the physical world. it is critical that a good function is chosen that accurately represents, in a single number, the goodness of the solution. the fitness function and the solution space must be specifically developed for optimization, and implementation is not depending on the physical system being optimized. third, initialize random swarm location and velocities. to begin searching for the optimal position in the solution space, each particle begins at its own random location. since its initial position is the only location encountered by each particle at the starting run, this position becomes each particle’s respective pbest. the first gbest is then selected from among these initial positions. fourth, systematically fly the particles through the figure 1. algorithm of pso m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 69 solution space. each particle must then be moved through the solution space as if it was a bee in a swarm. the algorithm acts on each particle one by one, moving it by a small amount and cycling through the entire swarm. the following steps are enacted on each particle individually. evaluate the particle’s fitness: compare to gbest, pbest. the fitness function, using the coordinates of the particle in solution space, returns a fitness value to be assigned to the current location. if the value is greater than the value at the respective pbest for that particle, or the global gbest, then the appropriate locations are replaced with the current location. update the particle’s velocity: the manipulation of a particle’s velocity is the core element of the entire optimization. the velocity of the particle is changed according to the relative locations of pbest and gbest. it is accelerated in the directions of these locations of greatest fitness according to equation (1): 𝑣𝑛 = 𝑤 ∗ 𝑣𝑛 + 𝑐1 ∗ 𝑟𝑎𝑛𝑑 ∗ �𝑝𝑏𝑒𝑠𝑡,𝑛 − 𝑥𝑛�+ 𝑐2 ∗ 𝑟𝑎𝑛𝑑 ∗ �𝑔𝑏𝑒𝑠𝑡,𝑛 − 𝑥𝑛� (1) where vn is the velocity of the particle in the n th dimension and xn is the particle’s coordinate in the nth dimension, w is inertial weight. move the particle: once the velocity has been determined, it is simple to move the particle to its next location. the velocity is applied for a given time-step, usually chosen to be one and new coordinate is computed for each of the dimensions according to equation (2). the particle is then moved to the location calculated by equation (2). 𝑥𝑛 = 𝑥𝑛 + ∆𝑡 ∗ 𝑣𝑛 (2) the composite nature of this algorithm composed of several independent agents makes it especially conducive to implementation on parallel processors. next, after this process is carried out for each particle in the swarm, the process is repeated starting from the fourth step. repetition of this cycle is continued until the termination criteria are met. the criterion most often used in optimizations with the pso is a maximum iteration number. with this termination condition, the pso ends when the process starting from the fourth step has been repeated a user-defined number of times. b. load flow studies load flow studies [11] performed in major areas of power system development and operation because of some reasons. the first reason is load-flow performed to determine the steady state operation of an electric system. it calculates voltage drop on each feeder, the voltage at each bus, and the power flow in all branch and feeder circuits. the second reason is to determine the system voltage reminds within specified limits under various contingency conditions, and whether pieces of equipment such as transformers and conductors are overloaded. the third reason is that load flows are often used to identify the need for additional generation, capacitive or inductive avr support or placement of capacitors and/or reactors to maintain the system voltages within limits. the fourth reason is that losses in each branch and total system power losses are also able to be calculated. it is necessary to plan, economic scheduling and control and existing system as well as planning its future expansion. it allows identification of real and reactive power flows, voltage profiles, power factor and any overloads in the network. this allows engineer to investigate the performance of network under a variety operating condition. line power flows consider the lines connecting buses i and k. the line and the transformers at each end can be represented by a circuit with series admittance yik and two shunt admittances yik0 and yki0 as shown in figure 2. the current field fed by bus i into the line can be expressed as: 𝐼𝑖𝑘 = 𝐼𝑖𝑘 + 𝐼𝑖𝑘0 (3) where 𝐼𝑖𝑘0 is expressed in equation (4) 𝐼𝑖𝑘0 = (𝑉𝑖 − 𝑉𝑘)𝑦𝑖𝑘 (4) v is the voltage magnitude at bus, y is admittance in the line, 𝐼𝑖𝑘0 = 𝑉𝑖𝑦𝑖𝑘0 (5) equation (3) is rewritten as: 𝐼𝑖𝑘 = (𝑉𝑖 − 𝑉𝑘)𝑦𝑘 + 𝑉𝑖𝑦𝑖𝑘0 (6) the power fed into the line from bus i is: 𝑆𝑖𝑘 = 𝑃𝑖𝑘 + 𝑄𝑖𝑘 (7) where s is power, p is real power and q is reactive power. figure 2. representations of a line and transformers connected between two buses m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 70 and, 𝑆𝑖𝑘 = 𝑉𝑖𝐼𝑖𝑘 ∗ (8) therefore: 𝑆𝑖𝑘 = 𝑉𝑖(𝑉𝑖 ∗ − 𝑉𝑘 ∗)𝑦𝑖𝑘 ∗ + 𝑉𝑖𝑉𝑖 ∗𝑦𝑖𝑘0 ∗ (9) power fed into the line from bus k is: 𝑆𝑘𝑖 = 𝑉𝑘(𝑉𝑘 ∗ − 𝑉𝑖 ∗)𝑦𝑖𝑘 ∗ + 𝑉𝑘𝑉𝑘 ∗𝑦𝑘𝑖0 ∗ (10) the power loss in the (i-k)th line is the sum of power flows determined from equation (7) and (8) as follows: 𝑃𝐿𝑖𝑘 = 𝑆𝑖𝑘 + 𝑆𝑘𝑖 for all i, k (11) the total transmission loss can be computed by summing all the line flows of the power system: 𝑃𝐿𝑜𝑠𝑠 = ∑ 𝑆𝑙 𝑛 𝑙=1 (12) 𝑃𝐿𝑜𝑠𝑠 is total power loss, 𝑆𝑙 is total power fed, where: 𝑆𝑙 = 𝑆𝑖𝑘 + 𝑆𝑘𝑖 (13) real (active) and reactive power can be expressed as follows: 𝑃𝑖 = |𝑉𝑖| ∑ |𝑉𝑘||𝑌𝑖𝑘| cos(𝛿𝑖 − 𝛿𝑘 − 𝜃𝑖𝑘0) 𝑛 𝑘=1 (14) 𝑄𝑖 = |𝑉𝑖| ∑ |𝑉𝑘||𝑌𝑖𝑘| sin(𝛿𝑖 − 𝛿𝑘 − 𝜃𝑖𝑘0) 𝑛 𝑘=1 (15) where δ is phase angle and θ is load angle. iii. methodology this proposed study is to find optimum candidate bus for shunt capacitor placement and determine optimum sizing using pso. shunt capacitor functions as compensation device to improve line losses. total losses of transmission line were calculated using load flow calculation of newton raphson method. shunt capacitor considered to be installed to load buses in order to improve line losses [10]. the ieee 14 bus power system test of this study, as shown in figure 3, has been performed over matlab under two conditions which were the base case and increasing 100% load. further, the voltage of each bus can be figured out under both scenarios and calculation of derivative load bus voltage carried out to identify the most sensitive bus where became optimum candidate bus of shunt capacitor placement. capacitor size was limited beyond the range of 0 to 200 mvar. table 1 and table 2 show the bus position and voltage limit for p-v buses in ieee 14 bus power system, respectively. power flows used in this study is to determine line flows and losses. this method determines if the system voltage remains within specified limits under various contingency table 1. scenario of ieee 14 bus power system bus code function bus position 1 load buses 4, 5,7, 9, 10, 11, 12, 13, 14 2 generator bus [3] 2, 3, 6, 8 3 slake bus 1 table 2. voltage limit for p-v buses (p.u.) through controlling avr no bus vmin vmax 2 0.95 1.05 3 0.95 1.02 6 0.95 1.09 8 0.95 1.09 figure 3. ieee 14 bus power systems m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 71 conditions so that the voltages drop on each feeder can be revealed. load flow calculation was conducted through equation (13) to (15) to determine the steady state operation of an electric system. it calculates voltage drop on each feeder, voltage at each bus, and the power flow in all branch and feeder circuits. the second step was to determine the derivative load bus voltage. derivative load buses voltage calculates the ratio between voltage change at a bus and the change which is caused by increasing load at a bus. the lower value of derivative load bus voltage indicates more sensitive bus. derivative load bus voltage is calculated using equation (16). 𝑑𝑉𝑖 𝑑𝑙𝑓 = lim𝑙𝑓→0 � ∆𝑑𝑉𝑖 ∆𝑑𝑙𝑓 � (16) where 𝑑𝑉𝑖 is the small change of voltage magnitude at bus i and 𝑑𝑙𝑓 is small a change which is caused by load increase. next step is to simulate the pso to determine the shunt capacitor sizing at the most sensitive bus. besides proposing shunt capacitor at the most sensitive bus, this study also proposes shunt capacitor to install at two buses which were at the most sensitive bus and the second sensitive bus. it carried out to afford more loss reduction on the power system. parameters of pso consist of c1 and c2, inertia weight, population size, and iteration. the parameter of c1 and c2 are scaling factors which determine the relative pull of local exploitation (pbest) and global exploration (gbest). each of this value was 2.0 which has been considered as the best choice and this value become standard in the literature [12] the population is total particles in a swarm. this study has chosen the population of 40 to search the best solution. inertia weight identifies the extent of particles remind along its own courses without affection of the pull of pbest and gbest. in other words, it purposes to attempt the balance between local exploitation and global exploration. this study decides inertia weight of 1 with the dumping inertia ratio was 0.99. iteration is the repetition of the particles searching solution space until the certain termination criteria of iteration. the iteration of the present study was 400 iterations. the objective function of the present study was expressed based on the equation (17). 𝑃𝐿𝑜𝑠𝑠 = ∑ ∑ 𝐺𝑖𝑗 2 |𝑉𝑖|2 + |𝑉𝑘|2 − 𝑁 𝑘=1 𝑘≠𝑖 𝑁 𝑖=1 2𝑉𝑖𝑉𝑘cos𝛿𝑖−𝛿𝑘 (17) where 𝑃𝐿𝑜𝑠𝑠 is real power loss, i and k are bus number, v is voltage magnitude, and δ is phase angle. iv. result and discussion this simulation study has been conducted to promote voltage profile and line losses in the power system by proposing optimum placement and its optimum size of shunt capacitor on the ieee 14 bus power system. the optimum placement of capacitor was chosen by determining the sensitive load buses where the voltage drops significantly. further pso was applied to determine the sizing of shunt capacitor. the shunt capacitor considered to be placed on load buses were bus number 4, 5, 7, 9, 10, 11, 12, 13, and 14. the first scenario was the base case (100% loads) and the second scenario was done by increasing the load about 100% (200% load). a. ieee 14 bus power system table 3 shows voltage profile before optimization. voltage profile proposed to be improved by placing shunt capacitor at the most sensitive bus where the high bus voltages drop occurred. pso was applied to determine the optimum size of shunt capacitor. voltage profile under normal load and increasing 100% load has been illustrated clearly in figure 4. it can be seen figure 4. voltage profile of various load 0.9 0.95 1 1.05 1.1 1.15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 v ol ta ge m ag ni tu de ( p. u) bus number base case increasing 100% load table 3. voltage profile at various load bus num. voltage profile (p.u) of base case voltage profile (p.u) of increasing 100% load 1 1.06 1.06 2 1.045 1.045 3 1.01 1.01 4 1.018449329 0.978022172 5 1.020068977 0.981296464 6 1.07 1.07 7 1.060890201 1.015075462 8 1.09 1.09 9 1.054154644 0.981174147 10 1.049511205 0.980939013 11 1.056152878 1.017463192 12 1.055053877 1.034729119 13 1.05011979 1.020164075 14 1.034393263 0.958853595 m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 72 that increasing load will drop voltage profile on the load buses. figure 5 present line losses of ieee 14 bus power system testing for the base case and increasing 100% load. the line losses were taken from transmission line flow distribution. total line losses of base case attained 13.39375 mw and it was 67.64585 mw for increasing 100% load. based on figure 5, total line loss increase along with the increasing of the load. b. optimum placement of shunt capacitor derivative load bus voltage was calculated to determine the optimum candidate bus of shunt capacitor placement. derivative load bus is the ratio of the change of voltage in respect to load factor. this ratio value indicates the sensitivity of load at buses. the low value of derivative load bus voltage identifies the sensitive bus. table 4 shows the results of derivative load bus voltage for the base case and increasing 100% load. the result shows that the lowest value attained at bus no. 14 for both base case and increasing 100% load. it was -0.05583 for the base case and -0.07104 for increasing 100% load. further it followed by bus no. 9, 10, 7, 4, 5, 11, 13, and 12 for the base case. the result of increasing 100% load was followed by bus no 9, 10, 5, 4, 7, 11, 13, and 12. based on these results, the most sensitive bus has been determined at bus number 14 for either base case or increasing 100% load. in this study, bus number 14 has been identified as optimum candidate bus for shunt capacitor placement in order to improve line losses on the ieee 14 bus power system. c. optimum sizing of shunt capacitor pso was proposed to find a solution in finding the optimum size of shunt capacitor to reduce line losses. simulations have been carried out to get the optimum size for both base case and increasing 100% load. the simulations carried out beyond two scenarios. first, the optimum location of shunt capacitor allocated on the most sensitive bus which was at bus number 14. further second scenario simulated with proposing two capacitor placements which were bus number 14 and nine respectively. placing shunt capacitor at two buses was an aim to get more reduction of losses. table 5 describes the results of the first scenario which are the optimum capacitor sizing (qc), power losses, and loss reduction ratio for optimum location at bus number 14. it also can be seen the results of the second scenario for proposing two shunt capacitors at bus number 14 and 9. the first scenario determined the optimum size of shunt capacitor is 8.1730 mvar and the second scenario is determined about 8.3881 mvar. the loss reduction ratio was 0.9801% and 1.1234% for the first and second scenario respectively. figure 6 is the comparison of total line losses before and after shunt capacitor placements. a total line loss without optimization was 13.393 mw, and it decreased up to 13.262 mw by allocating shunt capacitor at the most sensitive bus which was bus number 14. additions of shunt capacitor at bus no 14 and 9 attained total line losses about 13.243 mw. the line loss reduced more by allocating shunt capacitor at two buses, but it was not a significant reduction compare with only one shunt capacitor placement figure 5. total line losses of base case and increasing 100% load 13.393745 5 67.645847 1 0 10 20 30 40 50 60 70 80 base case increasing 100% load t ot al l in e l os se s (m w ) table 5. optimum size of shunt capacitor and power losses for base case optimal location qc (mvar) pl (mw) loss reduction ratio (%) bus 14 8.1730 13.2625 0.9801 buses 14&9 8.3881 13.2433 1.1234 table 4. derivative load bus voltage base case increasing 100% load candidate bus no. derivative load bus voltage (dvi/dlf) candidate bus no. derivative load bus voltage (dvi/dlf) 14 -0.05583 14 -0.07104 9 -0.04528 9 -0.06223 10 -0.04518 10 -0.06017 7 -0.02937 5 -0.04816 4 -0.02891 4 -0.04733 5 -0.0271 7 -0.04336 11 -0.02658 11 -0.03455 13 -0.02494 13 -0.02946 12 -0.01764 12 -0.02017 m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 73 at the most sensitive bus no. 14. further simulation has been conducted to determine the optimum sizing of shunt capacitor for increasing 100% load. the simulations run beyond two scenarios. the first scenario was done by allocating shunt capacitor at the most sensitive bus which was bus no. 14. the second scenario simulated by allocating two capacitors at bus no. 14 and 9. table 6 present the results which are optimum size of the capacitor (qc), power losses and loss reduction ratio. optimum shunt capacitor size is determined 23.982 mvar with allocation shunt capacitor at bus no. 14. power loss reduced to be 65.5019 mw and the loss reduction ratio is approximately 3.1693%. other result shows that optimum shunt capacitor size is determined about 28.53 mvar for the allocation shunt capacitors at bus no. 14 and 9. the power loss is reduced up to 64.9233 mw and the loss reduction ratio about 4.0247%. comparison of power losses before and after allocating shunt capacitors for increasing 100% load is described in figure 7. total line losses before installing shunt capacitor reached up to 67.645 mw. line losses decreased to be 65.501 mw after installing a shunt capacitor at the most sensitive bus no. 14. it decreased up to 4.932 mw by installing shunt capacitor at two buses no 14 and nine which considered the two highest sensitive buses in this study. the results of shunt capacitor installation gave almost same trend for the base case and increasing 100% load. installation of shunt capacitor device as the compensatory device has been proven to improve power losses on the line in the ieee 14 bus power system. there can be figured out that proposing shunt capacitor at the most sensitive bus was able to reduce line losses significantly. d. voltage profile before and after optimization a series of simulation have been conducted to determine optimum candidate bus and optimum sizing to propose shunt capacitor in order to improve line losses. voltage profile is the important parameter to assess the power system performance. figure 8 and figure 9 give detailed information about the voltage profile before and table 6. optimum size of shunt capacitor and power losses for increasing 100% load optimal location qc (mvar) pl (mw) loss reduction ratio (%) bus 14 23.982 65.5019 3.1693 buses 14&9 28.53 64.9233 4.0247 figure 7. power losses of increasing 100% load before and after shunt capacitor placement 63 64 65 66 67 68 without optimization bus14 bus14&9 t ot al li ne lo ss es ( m w ) figure 9. voltage profile comparison before and after optimization for 200% load figure 6. power losses of base case before and after shunt capacitor placement 13.15 13.2 13.25 13.3 13.35 13.4 13.45 without optimization bus14 bus14&9 t ot al li ne lo ss es ( m w ) figure 8. comparison of voltage profile before and after optimization for the base case m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 74 after optimization at each bus. the optimization was done by installing shunt capacitor at the most sensitive bus no. 14. figure 8 shows the voltage profiles before and after optimization for the base case which the loading factor was 100% load. it can be seen that the voltage profile improve almost at all load busses after installing shunt capacitor at the most sensitive bus no. 14. voltage profile seems to be increased significantly at the most sensitive bus no 14. in another result, figure 9 shows the comparison of voltage profile before and after optimization by installing shunt capacitor at bus no. 14 as the most sensitive bus. voltage profile improved significantly at the load bus. it also shows that voltage profile of the most sensitive bus improved well by installing shunt capacitor at this bus. furthermore, it influences voltage profile for other buses by improving the voltage which means giving better performance on the generator itself. pso simulates with population size of 40 along 400 iterations to obtain the best fitness or final solution for base case and increasing 100% load. the performance of the simulations displayed on the figure 10 and figure 11. it shows that the particles iterated to search the best fitness value over the solution space and finally determine the best solution. constant fitness value after initial iterations indicates that the particles start to find the best possible solution up to 400 iterations. e. validation power system efficiency becomes researchers’ concern to minimize losses on distribution network over the system. they proposed some additional devices as compensators to minimize losses. it needs to determine optimum dimensions and placement of compensator devices through various computational optimizations in finding solutions. figure 10. fitness value and iteration of the weakest bus for base case figure 11. fitness value and iteration number of the weakest bus for increasing 100% load m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 75 balachennaiah et al. [13] carried out a simulation study to determine the optimal location of static var compensator (svc) to minimize real power loss and improve voltage stability using harmony search algorithm. their study was also performed on ieee 14 bus power system and conducted under different loading from the normal load (100% loads) up to 200% load. the proposed method has been tested by simulating balachennaiah et al. data on the proposed method to find optimal location of svc in order to minimize real power loss. the comparison results of hsa and proposed method are illustrated in table 7 for normal load and increasing 100% load. table 7 shows that both hsa and proposed method determined the optimal placement was at bus 9 and 14 either for normal load and increasing 100% load. hsa recorded 0.44% reduction for normal load and 2.34% for increasing 100% load. meanwhile proposed method recorded 1.12% reduction ratio and it obtained up to 4.02% for increasing 100% load. proposed method recorded better reduction ratio compared with hsa. v. conclusion simulations have been performed to determine the optimum location and sizing of shunt capacitor in order to minimize line losses on the distribution network of ieee 14 bus power system. pso was proposed to find the best solution for shunt capacitor placement and sizing. the ieee 14 bus power system was carried out under normal load and further increase the load 100% than base case (200%). based on finding and discussion, the conclusion of the present study is that shunt capacitor placement proved to be able to minimize line loss on power system distribution. optimum placement of shunt capacitor under normal load was obtained at the most sensitive bus no. 14 and the optimum size determined about 8.17 mvar. loss reduction ratio was 0.98% for this scenario. the optimum location of shunt capacitor under loading factor of 2 or 200% load was also obtained at the bus no. 14. the optimum size of capacitor determined about 23.98 mvar with loss reduction ratio obtained up to 3.17%. pso was successfully also able to achieve multi-objective in finding the best solutions of capacitor placement and sizing. acknowledgement the author would like to thank ditlitabmas, ministry of ristekdikti, indonesia for providing financial support under pupt research scheme with contract no. 632/un27.21/lt/2016. references [1] i. ziari, “planning of distribution networks for medium voltage and low voltage,” queensland university of technology, 2011. [2] a. swarnkar et al., “optimal placement of fixed and switched shunt capacitors for large-scale distribution systems using genetic algorithms,” in ieee pes innovative smart grid technologies conference europe (isgt europe), 2010, pp. 1–8. [3] a. a. el-fergany and a. y. abdelaziz, “capacitor allocations in radial distribution networks using cuckoo search algorithm,” iet gener. transm. distrib., vol. 8, no. 2, pp. 223–232, feb. 2014. [4] y.-y. hong and b.-y. chen, “locating switched capacitor using wavelet transform and hybrid principal component analysis network,” ieee trans. power deliv., vol. 22, no. 2, pp. 1145–1152, apr. 2007. [5] a. a. abou el-ela et al., “optimal capacitor placement in distribution systems for power loss reduction and voltage profile improvement,” iet gener. transm. distrib., vol. 10, no. 5, pp. 1209–1221, apr. 2016. [6] m. yarmohamadi and m. taghikhani, “capacitor placement optimization in transmission system using hybrid pso and hbmo algorithms,” int. j. energy power, 2012, vol. 01, pp. 26–30. [7] x. su et al., “pso and improved bsfs based sequential comprehensive placement table 7. validation of proposed method method base case increasing 100% load hsa pl before opt. (mw) 13.393 70.859 pl after opt. 13.33 68.96 opt. loc. 9 14 9 14 qc 24.55 6.95 134.4 19.26 loss reduction ratio 0.44% 2.67% pso pl before opt. (mw) 13.393 67.645 pl after opt. 13.24 64.92 opt. loc. 9 14 9 14 qc 8.38 8.38 28.52 28.52 loss reduction ratio 1.12% 4.02% m.m. baiek et al. / j. mechatron. elect. power, and veh. technol. 07 (2016) 67-76 76 and real-time multi-objective control of delta-connected switched capacitors in unbalanced radial mv distribution networks,” ieee trans. power syst., vol. 31, no. 1, pp. 612–622, jan. 2016. [8] s. neelima and p. s. subramanyam, “optimal capacitor placement in distribution networks for loss reduction using differential evolution incorporating dimension reducing load flow for different load levels,” in ieee energytech, 2012, pp. 1–7. [9] s. soto and v. hinojosa, “stochastic optimal allocation of reactive power banks for system loss minimization,” ieee lat. am. trans., vol. 14, no. 4, pp. 1980–1987, apr. 2016. [10] i. hasan et al., “losses reduction and voltage improvement using optimum capacitor allocation by pso in power distribution networks,” iremos, vol. 06, no. 04, pp. 1219–1226, 2013. [11] lingwen gan et al., “optimal power flow in tree networks,” in 52nd ieee conference on decision and control, 2013, pp. 2313–2318. [12] j. robinson and y. rahmat-samii, “particle swarm optimization in electromagnetics,” ieee trans. antennas propag., vol. 52, no. 2, pp. 397-407, feb. 2004. [13] p. balachennaiah et al., “optimal location of svc for real power loss minimization and voltage stability enhancement using harmony search algorithm,” int. j. electr. eng. technol., vol. 5, no. 1, pp. 26–34, 2014. i. introduction ii. basic theory a. particle swarm optimization b. load flow studies iii. methodology iv. result and discussion a. ieee 14 bus power system b. optimum placement of shunt capacitor c. optimum sizing of shunt capacitor d. voltage profile before and after optimization validation v. conclusion acknowledgement references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal providing authoritative source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become international platform with high scientific contribution for global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi) and managed to be issued twice in every volume. the first issue should be in the mid of the year and the second issue is in the end of the year. issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: www.mevjournal.com mev allows reuse and remixing of its content, in accordance with a cc license of cc by-nc-sa. article management & plagiarism check every article submitted to mev journal shall use reference management software e.g. endnote ® or mendeley. accepted article to be published in mev journal will be proofed using grammarly ® checker software. plagiarism screening will be conducted by mev editorial board using crosscheck tm powered by ithenticate ® and grammarly ® plagiarism checker. article processing charges every article submitted to mev journal will not have any article processing charges. this includes peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. indexing & abstracting indexed in ebscohost, google scholar, directory of open access journal (doaj), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), mendeley, citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. accreditation mev has been accredited as an indonesian scientific journal by indonesian institute of sciences (lipi) by 15 april 2015, and by ministry of research, technology and higher education (via arjuna) by 21 september 2015. accreditation number (lipi): 633/au/p2mi-lipi/03/2015 valid thru: 15 april 2020. accreditation number (ministry of rthe): 1/e/kpt/2015 valid thru: 21 september 2019. postal address research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2 nd floor, r209 bandung, west java, 40135 indonesia telp: +62-022-2503055 (ext. 215) telp: +62-022-2504770 (ext. 203) fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com business hour: monday to friday 08:00 to 16:00 gmt+7 http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2 nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc) avda. bases de manresa, 61-73 08242 manresa (barcelona), spain assoc. prof. john young school of engineering and it, the university of new south wales australian defence force academy, po box 7916, canberra bc act 2610, australia george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7summarecon gading serpong, tangerang, banten, 15810, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. arjon turnip technical management unit for instrumentation development lipi komp lipi jl sangkuriang, bld 40, bandung 40135, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2 nd fl, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 deputy editors aam muharam, m.t. electrical engineering tinton d atmaja, m.t. informatic systems and electrical engineering managing editors, central office ghalya pikra, m.t. mechanical engineering merry i devi, s.t. industrial engineering hendri m saputra, m.t. robotics and mechatronics managing editor, asia pacific region yanuandri putrasari, m.eng. mechanical engineering managing editor, europe region naili huda, m.eng.sc. industrial engineering editors aditya sukma nugraha, m.t. mechanical engineering agus risdiyanto, m.t. electrical engineering amin, m.t. electrical engineering arief a firdaus, s.i.kom. communication science arini wresta, m.eng. chemical engineering bambang wahono, m.eng. mechanical engineering dian andriani, m.eng. bioenergy engineering dr. edwar yazid dynamics and control system kadek heri sanjaya, ph.d ergonomics, biomechanics, physiology maulana arifin, m.t. mechanical engineering midriem mirdanies, m.t. computer engineering muhammad kasim, m.renen electrical engineering nur rohmah, m.t. chemical engineering rakhmad indra pramana, m.t. mechanical and material engineering rifa rahmayanti, m.sc mechatronics and robotics sapdo utomo, m.t. mechatronics and robotics vita susanti, s.kom computer science yayat ruhiyat, a.md. electrical engineering web admin dadan r saleh, m.t. informatics engineering secretariat andri j purwanto, s.t. mechanical engineering graphic designer yukhi mustaqim kusuma sya bana, s.sn. graphic design journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 © 2016 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (jmev) is an international journal indexed by google scholar, directory of open access journal (doaj), indonesian scientific journal database (isjd), indonesian publication index (ipi)/portal garuda, crossref, mendeley, citeulike, academic journal database, researchbib, cite factor, and others. its digital object identifier (doi) prefix is 10.14203. in this issue, seven papers are published with the total number of paper pages of 66 pages. the selected papers have passed high level of reviews and revisions based on the standard operating procedure of the journal. the authors come from indonesia, malaysia, vietnam, japan, iraq, australia, and united kingdom. four topics of the papers are related to mechatronics which address empirical mode decomposition (emd) method for characterization of random vibration signals, nonlinear tracking control of a 3-d overhead crane, review on the application of physiological and biomechanical measurement methods in driving fatigue detection, and optimized object tracking technique using kalman filter. one topics are related to electrical power concerning cfd model for analysis of performance, water and thermal distribution, and mechanical related failure in pem fuel cells. in the scope of vehicular technology there are two papers presented those are abs based on fuzzy logic control and cooperative braking in electric and hybrid vehicles. since the first issue, our journal provides discretion in financial term by waiving the article processing charge. we are planning to improve the quality by registering the journal to other international academic citation index. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2016 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 ii list of contents hardware simulation of automatic braking system based on fuzzy logic control noor cholis basjaruddin, kuspriyanto, suhendar, didin saefudin, virna apriani azis 1-6 a cfd model for analysis of performance, water and thermal distribution, and mechanical related failure in pem fuel cells maher a.r. sadiq al-baghdadi 7-20 application of empirical mode decomposition method for characterization of random vibration signals setyamartana parman, edwar yazid 21-26 nonlinear tracking control of a 3-d overhead crane with friction and payload compensations anh-huy vo, quoc-toan truong, ha-quang-thinh ngo, quoc-chi nguyen 27-34 review on the spplication of physiological and biomechanical measurement methods in driving fatigue detection kadek heri sanjaya, soomin lee, tetsuo katsuura 35-48 modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake zaini dalimus, khallid hussain, andrew j. day 49-56 optimized object tracking technique using kalman filter liana ellen taylor, midriem mirdanies, roni permana saputra 57-66 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 07, issue 1, july 2016 abstracts sheet e-issn: 2088-6985 date of issues: 29 july 2016 p-issn: 2087-3379 the descriptions given are free terms. this abstracst sheet may be reproduced without permission or change. noor cholis basjaruddin a , kuspriyanto b , suhendar a , didin saefudin a , virna apriani azis a ( a department of electrical engineering, politeknik negeri bandung, jl. gegerkalong hilir, ds. ciwaruga, bandung, indonesia; b school of electrical engineering and informatics, institut teknologi bandung, jl. ganesha no. 10, bandung, indonesia) hardware simulation of automatic braking system based on fuzzy logic control journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 1-6, 13 ill, 4 tab, 20 ref. in certain situations, a moving or stationary object can be a barrier for a vehicle. people and vehicles crossing could potentially get hit by a vehicle. objects around roads as sidewalks, road separator, power poles, and railroad gates are also a potential source of danger when the driver is inattentive in driving the vehicle. a device that can help the driver to brake automatically is known as automatic braking system (abs). abs is a part of the advanced driver assistance systems (adas), which is a device designed to assist the driver in driving the process. this device was developed to reduce human error that is a major cause of traffic accidents. this paper presents the design of abs based on fuzzy logic which is simulated in hardware by using a remote control car. the inputs of fuzzy logic are the speed and distance of the object in front of the vehicle, while the output of fuzzy logic is the intensity of braking. the test results on the three variations of speed: slow-speed, medium-speed, and high-speed shows that the design of abs can work according to design. (author) keywords: automatic braking system; advanced driver assistance system; fuzzy logic. maher a.r. sadiq al-baghdadi a ( a department of mechanical engineering, faculty of engineering, university of kufa, najaf, kufa, iraq) a cfd model for analysis of performance, water and thermal distribution, and mechanical related failure in pem fuel cells journal of mechatronics, electrical power, and vehicular technology, july 2016, vol.7, no. 1, p. 7-20, 13 ill, 3 tab, 24 ref. this paper presents a comprehensive three-dimensional, multiphase, non-isothermal model of a proton exchange membrane (pem) fuel cell that incorporates significant physical processes and key parameters affecting the fuel cell performance. the model construction involves equations derivation, boundary conditions setting, and solution algorithm flow chart. equations in gas flow channels, gas diffusion layers (gdls), catalyst layers (cls), and membrane as well as equations governing cell potential and hygrothermal stresses are described. the algorithm flow chart starts from input of the desired cell current density, initialization, iteration of the equations solution, and finalizations by calculating the cell potential. in order to analyze performance, water and thermal distribution, and mechanical related failure in the cell, the equations are solved using a computational fluid dynamic (cfd) code. performance analysis includes a performance curve which plots the cell potential (volt) against nominal current density (a/cm 2 ) as well as losses. velocity vectors of gas and liquid water, liquid water saturation, and water content profile are calculated. thermal distribution is then calculated together with hygro-thermal stresses and deformation. the cfd model was executed under boundary conditions of 20°c room temperature, 35% relative humidity, and 1 mpa pressure on the lower surface. parameters values of membrane electrode assembly (mea) and other base conditions are selected. a cell with dimension of 1 mm x 1 mm x 50 mm is used as the object of analysis. the nominal current density of 1.4 a/cm 2 is given as the input of the cfd calculation. the results show that the model represents well the performance curve obtained through experiment. moreover, it can be concluded that the model can help in understanding complex process in the cell which is hard to be studied experimentally, and also provides computer aided tool for design and optimization of pem fuel cells to realize higher power density and lower cost. (author) keywords: cfd; pem; fuel cell; multi-phase; hygro thermal stress. setyamartana parman a , edwar yazid b ( a mechanical engineering departement, universiti teknologi petronas, bandar seri iskandar, 31750 tronoh, perak, malaysia; b research center for electrical power and mechatronics, indonesian institute of sciences, jl. sangkuriang komplek lipi gedung 20, 40135 bandung, indonesia) application of empirical mode decomposition method for characterization of random vibration signals journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 21-26, 8 ill, 2 tab, 10 ref. characterization of finite measured signals is a great of importance in dynamical modeling and system identification. this paper addresses an approach for characterization of measured random vibration signals where the approach rests on a method called empirical mode decomposition (emd). the applicability of proposed approach is tested in one numerical and experimental data from a structural system, namely spar platform. the results are three main signal components, comprising: noise embedded in the measured signal as the first component, first intrinsic mode function (imf) called as the wave frequency response (wfr) as the second component and second imf called as the low frequency response journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv (lfr) as the third component while the residue is the trend. bandpass filter (bpf) method is taken as benchmark for the results obtained from emd method. (author) keywords: emd, bpf, imf, vibration signals. anh-huy vo a , quoc-toan truong a , ha-quang-thinh ngo a,b and quoc-chi nguyen a,b ( a department of mechatronics, ho chi minh city university of technology, 268 ly thuong kiet st., dist. 10, 703500, ho chi minh city, vietnam; b control and automation laboratory, , ho chi minh city university of technology,268 ly thuong kiet st., dist. 10, 703500, ho chi minh city, vietnam) nonlinear tracking control of a 3-d overhead crane with friction and payload compensations journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 27-34, 9 ill, 0 tab, 21 ref in this paper, a nonlinear adaptive control of a 3d overhead crane is investigated. a dynamic model of the overhead crane was developed, where the crane system is assumed as a lumped mass model. under the mutual effects of the sway motions of the payload and the hoisting motion, the nonlinear behavior of the crane system is considered. a nonlinear control model-based scheme was designed to achieve the three objectives: (i) drive the crane system to the desired positions, (ii) suppresses the vibrations of the payload, and (iii) velocity tracking of hoisting motion. the nonlinear control scheme employs adaptation laws that estimate unknown system parameters, friction forces and the mass of the payload. the estimated values were used to compute control forces applied to the trolley of the crane. the asymptotic stability of the crane system is investigated by using the lyapunov method. the effectiveness of the proposed control scheme is verified by numerical simulation results. (author) keywords: 3-d overhead crane; nonlinear adaptive control; lyapunov method; euler-lagrange equation; sway control. kadek heri sanjaya a , soomin lee b , tetsuo katsuura c ( a research centre for electrical power and mechatronics, indonesian institute of sciences, 2nd floor, 20th building, komplek lipi, jalan cisitu no. 21/154d, bandung, indonesia; b center for environment, health, and field sciences, chiba university, 6-2-1 kashiwa-no-ha, kashiwa, chiba prefecture 277-0882, japan; c humanomics laboratory, graduate school of engineering, chiba university, 133 yayoi-cho, inage-ku, chiba-shi, japan) review on the application of physiological and biomechanical measurement methods in driving fatigue detection journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 35-48, 11 ill, 0 tab, 92 ref. previous studies have identified driving fatigue as the main cause of road traffic accidents, therefore, the aim of this literature review is to explore the characteristics of driving fatigue both physically and mentally as well as to explore the technology available to measure the process of fatigue physiologically. we performed e-searching in the field of fatigue detection methods through keywords tracking. the instruments studied have their own strength and weakness, and some are intrusive while the others are non-intrusive. the accuracy and stability of measurements are also varied between those instruments. in order to create more reliable fatigue detection methods, it is necessary to involve more instruments with an interdisciplinary approach. our intention is to make this study as a stepping stone for a more comprehensive in-vehicle real-time manmachine interaction study. such study will not only be useful to prevent traffic accidents but also to bridge man and machine communication in the vehicle control along with developing newer technology in the field of vehicle automation. (author) keywords: driving fatigue; physiology; biomechanics; manmachine interface. zaini dalimus a , khallid hussain b , andrew j. day b ( a electrical engineering department, andalas university, indonesia; b school of engineering, design and technology, university of bradford, u.k) modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 49-56, 16 ill, 2 tab, 15 ref. in mixed-mode braking applications, the electric motor / generator (m/g) and hydraulic pressure valve are controlled to meet the driver’s braking demand. controlling these braking elements is achieved by modulating the current generated by the m/g and adjusting the fluid pressure to the wheel brake cylinders. this paper aims to model and design combined regenerative and hydraulic braking systems which, comprise an induction electric machine, inverter, nimh battery, controller, a pressure source, pressure control unit, and brake calipers. a 15 kw 1500 rpm induction machine equipped with a reduction gear having a gear ratio of 4 is used. a hydraulic brake capable to produce fluid pressure up to 40 bar is used. direct torque control and pressure control are chosen as the control criteria in the m/g and the hydraulic solenoid valve. the braking demands for the system are derived from the federal testing procedure (ftp) drive cycle. two simulation models have been developed in matlab ® /simulink ® to analyze the performance of the control strategy in each braking system. the developed model is validated through experiment. it is concluded that the control system does introduce torque ripple and pressure oscillation in the braking system, but these effects do not affect vehicle braking performance due to the high frequency nature of pressure fluctuation and the damping effect of the vehicle inertia. moreover, experiment results prove the effectiveness of the developed model. (author) keywords: mixed-mode braking, regenerative brake, induction machine, hydraulic brake, direct torque, pulse-wide modulation. liana ellen taylor a , midriem mirdanies b , roni permana saputra b ( a school of engineering and information technology universityof new south wales (unsw), canberra, act 2600, australia; b research center for electrical power and mechatronics, indonesian institute of sciences (lipi), komplek lipi bandung, jl. sangkuriang, gd. 20. lt. 2, bandung 40135, indonesia) optimized object tracking technique using kalman filter journal of mechatronics, electrical power, and vehicular technology, july 2016, vol. 7, no. 1, p. 57-66, 14 ill, 5 tab, 16 ref. this paper focused on the design of an optimized object tracking technique which would minimize the processing time required in the object detection process while maintaining accuracy in detecting the desired moving object in a cluttered scene. a kalman filter based cropped image is used for the image detection process as the processing time is significantly less to detect the object when a search window is used that is smaller than the entire video frame. this technique was tested with various sizes of the window in the cropping process. matlab ® was used to design and test the proposed method. this paper found that using a cropped image with 2.16 multiplied by the largest dimension of the object resulted in significantly faster processing time while still providing a high success rate of detection and a detected center of the object that was reasonably close to the actual center. (author) keywords: kalman filter; object tracking; object detection; cropping; color segmentation. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 http://mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 indonesian institute of sciences (lipi) publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: acc number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: acc number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62 22 2503055 (ext. 215) tel: +62 22 2504770 (ext. 203) fax: +62 22 2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://mevjournal.com/ http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 http://mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.php/ mev/login need a username/password? go to registration at: http://mevjournal.com/index.php/ mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nc-licensed work does not necessarily mean you have violated the term. http://mevjournal.com/ http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 editor-in-chief prof. dr. estiko rijanto indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia estiko.rijanto@lipi.go.id international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea, pe department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 http://mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 deputy editors tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia mechanical engineering managing editors, central office kadek heri sanjaya, ph.d research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia industrial engineering dian andriani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia industrial engineering rifa rahmayanti, m.sc research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia robotics and mechatronics managing editor, asia pacific region aam muharam, m.t. asem, interdisciplinary graduate school of engineering kyushu university fukuoka, japan yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, republic of corea managing editor, europe region naili huda, m.eng.sc. warwick university coventry cv4 7al, united kingdom roni permana saputra, m.eng dyson school of design engineering robot intelligence lab imperial college, london, united kingdom editors aditya sukma nugraha, m.t. mechanical engineering agus risdiyanto, m.t. electrical engineering amin, m.t. electrical engineering arief a firdaus, s.i.kom. communication science arini wresta, m.eng. chemical engineering dr. edwar yazid dynamics and control system erie martides, m.t. material engineering hendri maja saputra, m.t. mechatronics and robotics midriem mirdanies, m.t. computer engineering muhammad kasim, m.renen electrical engineering nur rohmah, m.t. chemical engineering qidun maulana binu soesanto, m.t. mechanical engineering rakhmad indra pramana, m.t. mechanical and material engineering sapdo utomo, m.t. mechatronics and robotics vita susanti, s.kom computer science yayat ruhiyat, a.md. electrical engineering web admin dadan r saleh, m.t. informatics engineering secretariat andri j purwanto, s.t. mechanical engineering graphic designer yukhi mustaqim kusuma sya bana, s.sn. graphic design http://mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 http://mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 © 2017 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. http://mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recoginzed indexers. mev digital object identifier (doi) prefix is 10.14203. in this issue, seven papers are published with the total number of 69 paper pages. the authors come from indonesia, pr china, united kingdom, australia, and malaysia. two papers are related to mechatronics. one paper describes performance comparison for formation control of multiple nonholonomic wheeled mobile robots, and the other presents design and implementation of hardware in the loop simulation for electronic ducted fan rocket control system. three papers address topics on electrical power. the first paper deals with a compact design of multi-feeder data logging system for power quality measurement. the second paper describes a method to increase efficiency of a 33 mw otec in indonesia using flat-plate solar collector. the third paper presents optimization of smes and tcsc using particle swarm optimization for oscilation mitigation in a multi machine power system. in the scope of vehicular technology there are two papers presented. the first paper reports a simulation study to compare rls-ga and rls-pso algorithms for li-ion battery soc and soh estimation. the second paper describes afr and fuel cut-off modeling of lpg fueled engine using fuzzy logic controller. since the first volume, our journal provides convenience for authors to submit the paper by waiving the article processing charge. in order to improve the quality of the journal, we are on process to register the journal to international academic citation index. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their perpetual supports. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors for their great contributions for the advancement of this journal. we sincerely hope this publication would contribute to the enhancement of science and technology. bandung, july 2017 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 http://mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 ii list of contents a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer hendri novia syamsir, dalila mat said, yusmar palapa wijaya 1-10 optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system dwi lastomo, herlambang setiadi, muhammad ruswandi djalal 11-21 performance comparison of consensus protocol and l- approach for formation control of multiple nonholonomic wheeled mobile robots ali alouache, qinghe wu 22-32 increasing efficiency of a 33 mw otec in indonesia using flat-plate solar collector for the seawater heater iwan rohman setiawan, irwan purnama, abdul halim 33-39 comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study latif rozaqi, estiko rijanto, stratis kanarachos 40-49 afr and fuel cut-off modeling of lpg-fueled engine based on engine, transmission, and brake system using fuzzy logic controller (flc) muji setiyo, suroto munahar 50-59 design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware reza aulia yulnandi, carmadi machbub, ary setijadi prihatmanto, egi muhammad idris hidayat 60-69 further articles can be found at http://www.mevjournal.com http://mevjournal.com/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 08, issue 1, july 2017 abstracts sheet e-issn: 2088-6985 date of issues: 31 july 2017 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. hendri novia syamsira,*, dalila mat saidb, yusmar palapa wijayaa (aelectronics engineering, polytechnic caltex riau, jl. umbansari no 1 rumbai, pekanbaru, riau 28265, indonesia; bcentre of electrical energy systems (cees), university technology malaysia (utm), johor bahru 81310, malaysia) a compact design of multi-feeder data logging system for power quality measurement with a multiplexer and a single pq transducer journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 1-10, 13 ill, 7 tab, 15 ref. this paper presents a simple and costs effective equipment design multi-feeder data logger for recording and monitoring power quality. the system design uses remote supervising and multifeeder data logging system (resmos). the data collected through resmos portable unit (rmpu) will automatically be saved with the format as binary and comma separated value (csv). the time setting on the rmpu can be configured with minimum one minute per logging. this data logger uses a single transducer with a multiplexer for recording and monitoring ten channels of power quality at busbar. the system design has been validated with national metrology laboratory scientific and industrial research institute of malaysia (sirim). this tool has the advantage that it can be used to measure harmonic data more than 21st at the same time for ten channels and equipped with software making it easier for analysis data with low operational costs versus another power quality equipment. the experimental results indicate that the proposed technique can accelerate data reading with conversion rate one sample per second for each channel. the device can be used to measure harmonic level and power quality with a confidence level above 95% and percentage error under 2.43% for total harmonics distortion (thd) and 1.72% for voltage harmonics. (author) keywords: harmonic; power quality; measurement; data logging; multi-feeder. dwi lastomoa,*, herlambang setiadib, muhammad ruswandi djalalc (aupmb institut teknologi sepuluh nopember upmb building jl raya its, surabaya 60117, indonesia; bschool of information technology & electrical engineering the university of queensland, level 4/general purpose south building (buliding 78) st. lucia campus, brisbane, australia; cdepartment of mechanical engineering ujung pandang state polytechnics, jl. perintis kemerdekaan 7 km. 10, makassar, indonesia) optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system journal of mechatronics, electrical power, and vehicular technology, july 2017, vol.8, no. 1, p. 11-21, 17 ill, 8 tab, 24 ref. due to the uncertainty of load demand, the stability of power system becomes more insecure. small signal stability or low-frequency oscillation is one of stability issues which correspond to power transmission between interconnected power systems. to enhance the small signal stability, an additional controller such as energy storage and flexible ac transmission system (facts) devices become inevitable. this paper investigates the application of superconducting magnetic energy storage (smes) and thyristor controlled series compensator (tcsc) to mitigate oscillation in a power system. to get the best parameter values of smes and tcsc, particle swarm optimization (pso) is used. the performance of the power system equipped with smes and tcsc was analyzed through time domain simulations. three machines (whose power ratings are 71.641, 163, and 85 mw) nine buses power system was used for simulation. from the simulation results, it is concluded that smes and tcsc can mitigate oscillatory condition on the power system especially in lowering the maximum overshoot up to 0.005 pu in this case. it was also approved that pso can be used to obtain the optimal parameter of smes and tcsc. (author) keywords: power system oscillation; facts; smes; tcsc; pso. ali alouache*, qinghe wu (school of automation, beijing institute of technology, haidian district 100081, beijing, pr china) performance comparison of consensus protocol and l- approach for formation control of multiple nonholonomic wheeled mobile robots journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 22-32, 20 ill, 1 tab, 24 ref. this paper investigates formation control of multiple nonholonomic differential drive wheeled mobile robots (wmrs). assume the communication between the mobile robots is possible where the leader mobile robot can share its state values to the follower mobile robots using the leader-follower notion. two approaches are discussed for controlling a formation of nonholonomic wmrs. the first approach is consensus tracking based on graph theory concept, where the linear and angular velocity input of each follower are formulated using first order consensus protocol, such that the heading angle and velocity of the followers are synchronized to the corresponding values of the leader mobile robot. the second is lapproach (distance angle) that is developed based on lyapunov analysis, where the linear and angular velocity inputs of each follower mobile robot are adjusted such that the followers keep a desired separation distance and deviation angle with respect to the leader robot, and the overall system is asymptotically stable.the aim of this paper is to compare the performances of the presented methods for controlling a formation of wheeled mobile robots with journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv matlab simulations. (author) keywords: nonholonomic wmr; the leader-follower structure; graphtheory; consensus protocol; l- approach. iwan rohman setiawana, irwan purnamaa, abdul halimb (atechnical implementation unit for instrumentation development, indonesian institute of sciences (lipi), kompleks lipi gd. 30, jl. sangkuriang, bandung, indonesia; bdepartment of electrical engineering, faculty of engineering, university of indonesia kampus baru ui depok 16424, indonesia) increasing efficiency of a 33 mw otec in indonesia using flatplate solar collector for the seawater heater journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 33-39, 10 ill, 1 tab, 17 ref. this paper presents a design concept of ocean thermal energy conversion (otec) plant built in mamuju, west sulawesi, with 33 mwe and 7.1% of the power capacity and efficiency, respectively. the generated electrical power and the efficiency of otec plant are enhanced by a simulation of a number of derived formulas. enhancement of efficiency is performed by increasing the temperature of the warm seawater toward the evaporator from 26˚c up to 33.5˚c using a flat-plate solar collector. the simulation results show that by increasing the seawater temperature up to 33.5˚c, the generated power will increase up to 144.155 mwe with the otec efficiency up to 9.54%, respectively. the required area of flat-plate solar collector to achieve the results is around 6.023 x 106 m2. (author) keywords: enhanced efficiency; otec plant; flat-plate solar collector; mamuju west sulawesi. latif rozaqia*, estiko rijantoa, stratis kanarachosb (aresearch center for electrical power and mechatronics, indonesian institute of sciences (lipi), kampus lipi, jalan sangkuriang, gd.20, bandung 40135, indonesia; bcentre for mobility & transport, coventry university, united kingdom) comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 40-49, 9 ill, 3 tab, 24 ref this paper proposes a new method of concurrent soc and soh estimation using a combination of recursive least square (rls) algorithm and particle swarm optimization (pso). the rls algorithm is equipped with multiple fixed forgetting factors (mfff) which are optimized by pso. the performance of the hybrid rlspso is compared with the similar rls which is optimized by single objective genetic algorithms (soga) as well as multi-objectives genetic algorithm (moga). open circuit voltage (ocv) is treated as a parameter to be estimated at the same timewith internal resistance. urban dynamometer driving schedule (udds) is used as the input data. simulation results show that the hybrid rls-pso algorithm provides little better performance than the hybrid rlssoga algorithm in terms of mean square error (mse) and a number of iteration. on the other hand, moga provides pareto front containing optimum solutions where a specific solution can be selected to have ocv mse performance as good as pso. (author) keywords: li-ion; battery; state of charge (soc); state of health (soh); recursive least square (rls); particle swarm optimization (pso); genetic algorithm (ga). muji setiyo*, suroto munahar (department of automotive engineering, universitas muhammadiyah magelang, magelang, indonesia, jl. bambang sugeng km.05 mertoyudan magelang 56172) afr and fuel cut-off modeling of lpg-fueled engine based on engine, transmission, and brake system using fuzzy logic controller (flc) journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 50-59, 12 ill, 3 tab, 42 ref. during deceleration, continuous fuel flows into the engine not only causing over fuel consumption but also increasing exhausts emissions. therefore, this paper presents a simulation of afr and fuel cut-off modeling in the lpg-fueled vehicle using fuzzy logic controller (flc). the third generation of lpg kits (liquid phase injection, lpi) was chosen due to its technological equivalency to efi gasoline engine and promising to be developed. given that the fuel system control is complex and non-linear, flc has been selected because of simple, easy to understand, and tolerant to improper data. simulation results show that the afr and fuel cutoff controller able to maintenance afr at the stoichiometric range during normal operation and able to cut the fuel flow at deceleration time for saving fuel and reducing emissions. (author) keywords: lpg-fueled engine; deceleration; flc; afr; fuel cutoff. reza aulia yulnandi*, carmadi machbub, ary setijadi prihatmanto, egi muhammad idris hidayat (school of electrical engineering and informatics, institut teknologi bandung, jl. ganesha 10, bandung 40132, indonesia) design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware journal of mechatronics, electrical power, and vehicular technology, july 2017, vol. 8, no. 1, p. 60-69, 20 ill, 2 tab, 12 ref. hardware in the loop simulation (hils) is intended to reduce time and development cost of control system design. hils systems are mostly built by integrating both controller hardware and simulator software where the software is not an open source. moreover, implementing hils by using manufactured system is costly. this paper describes the design and implementation of hils for electric ducted fan (edf) rocket by using open-source platform for development with middleware. this middleware system is used to bridge the data flow between controller hardware and simulator software. a low-cost atmega 2560 8-bit microcontroller is used to calculate rocket’s attitude with direction cosine matrix (dcm) algorithm and pid controller is employed to regulate rocket’s dynamics based on desired specifications. x-plane 10 simulator software is used for generating simulated sensory data. the test results validate that hils design meets the defined specifications, i.e. angle difference of 0.3 degrees and rise time of 0.149 seconds on pitch angle. (author) keywords: hils; dcm; open-source platform; x-plane; middleware; edf rocket. mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various loads condition yanuandri putrasari a, b, *, achmad praptijanto a, arifin nur a, widodo budi santoso a, mulia pratama a, ahmad dimyani a, suherman a, bambang wahono a, b, muhammad khristamto aditya wardana a, b, ocktaeck lim c a research centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu no. 154d, bandung 40135, indonesia b graduate school of mechanical engineering university of ulsan mugeo-dong, nam-gu, ulsan 44610, south korea c school of mechanical engineering university of ulsan mugeo-dong, nam-gu, ulsan 44610, south korea received 25 october 2018; received in revised form 10 december 2018; accepted 12 december 2018 published online 30 december 2018 abstract efforts to find alternative fuels and reduce emissions of ci engines have been conducted, one of which is the use of dieselhydrogen dual fuel. one of the goals of using hydrogen in dual-fuel combustion systems is to reduce particulate emissions and increase engine power. this study investigates the thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at the various loads condition. the hydrogen was used as a secondary fuel in a single cylinder 667 cm3 diesel engine. the hydrogen was supplied to intake manifold by fumigation method, and diesel was injected directly into the combustion chamber. the results show that the performance test yielding an increase around 10% for the thermal efficiency value of diesel engines with the addition of hydrogen either at 2000 or 2500 rpm. meanwhile, emission analyses show that the addition of hydrogen at 2000 and 2500 rpm lead to the decrease of nox value up to 43%. furthermore, the smokeless emissions around 0% per kwh were occurred by hydrogen addition at 2000 and 2500 rpm of engine speeds with load operation under 20 nm. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: dual-fuel hydrogen; hydrogen engines; diesel-hydrogen; diesel-hydrogen efficiency; diesel-hydrogen emissions. i. introduction the use of alternative fuels in internal combustion engine [1][2][3] can reduce dependence on petroleumbased fuels, where this is a step forward to maintain the security and availability of energy sources. in this study, hydrogen was used as additional fuel in a conventional diesel engine to replace partially diesel fuel that was burned in the engine. the engine efficiency and exhaust emissions product when hydrogen replaces some amount of diesel fuel is the most exciting topic to be studied. previous studies on diesel-hydrogen show that the addition of hydrogen is a promising method for reducing unwanted exhaust emissions while maintaining the engine performance [4][5]. the engine operated with the addition of hydrogen may reduce nox over 90% [6], and simultaneously decreases soot emission by increasing the hydrogen addition [7][8][9]. however, nox emission increased at higher loads of compression ignition engine with hydrogen [10][11]. furthermore, the engine with 17% hydrogen content, the hydrogen–diesel–air mixture was stoichiometric and provided favorable conditions for generating combustion knock [12]. the other study by calik [13] and syed et al. [14] showed that the addition of hydrogen gas further managed the engine vibration both with a conventional diesel engine and biodiesel blend. the autoignition temperature of hydrogen gas is at 585°c; thus, it requires another autoignition source or trigger to burn it in an internal combustion engine. diesel fuel which has autoignition temperature 280°c, * corresponding author. tel: +62 821 2013 6976; fax: + 62 22 250 4773 e-mail address: yanu001@lipi.go.id; y.putrasari@gmail.com https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.49-56&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 50 much lower than hydrogen, can be used as a trigger for burning hydrogen inside the cylinder of diesel engines [15]. this combustion system is also called the "dieselhydrogen dual fuel." diesel with the addition of hydrogen provides many advantages both concerning performance and emission reduction. this application is possible because some of the diesel fuel is replaced by hydrogen which has a higher combustion efficiency and low hydrocarbon content. many works and studies on diesel-hydrogen have been widely reported. the research and development of hydrogen engines by das concluded that hydrogen could be used on both gasoline and diesel engines without any modification to its systems [16]. in ci engines the hydrogen can be used with diesel-hydrogen dual fuel model. therefore, nox emissions can be significantly reduced by monitoring engine conditions during operation, for example with a lean combustion model or by exhaust gas recirculation (egr) application. adnan et al., have conducted an investigation on a single cylinder 406 cm3 direct injection stationary diesel engine with the hydrogen addition [17]. in their study, the engines were operated at a fixed speed of 1500 rpm, and hydrogen was injected through the intake manifold, while diesel fuel was injected directly into the combustion chamber. the engine testing results showed an increase in performance up to 16%. however, the value of nox and co emissions tends to increase from 48 to 197 ppm, and 423 to 758 ppm respectively. another study on 4-cylinder diesel engines with the addition of hydrogen has been carried out by bari et al. [18]. the engine was operated at a constant speed of 1500 rpm with the addition of hydrogen varying from 1 to 6%. meanwhile, an electric generator was connected to the engine shaft to manage three variations of the load at 19 kw, 22 kw, and 28 kw. the test results showed an increase in brake thermal efficiency up to 36.3%, fuel savings up to 15.16%, and a decrease in hc, co2, and co. however, the value of nox emissions continue to rise. miyamoto et al. conducted a study of hydrogen addition on a single cylinder diesel engine equipped with an egr system [19]. diesel fuel was injected into the combustion chamber with a common rail fuel injection device. the egr ratio was regulated through a valve mechanism, while hydrogen was injected noncontinuously (intermittent) into the inlet air manifold using a gas injector. the machine was operated at a constant speed of 1500 rpm. test results showed that a combination of hydrogen addition with slow diesel fuel injection contributes to low combustion temperature, resulting in a decrease in nox without raising the remaining unburnt fuel. the reduction of smoke due to the addition of hydrogen is more significant than without hydrogen for the high egr ratio and slow diesel fuel injection time. previous references have discussed the application of hydrogen on diesel engine comprehensively. however, the engine efficiency and emissions in ci engine are very dependent on many factors such as energy input, fuel management strategy, combustion mode, initial conditions, and variation of loads. furthermore, the effects of various loads including the high and low load on the thermal efficiency and emissions of ci engine fueled with diesel-hydrogen dual fuel have not been explored and discussed in depth and complete. therefore, this paper aims to discuss the characterization of diesel-hydrogen dual fuel performance and exhaust emissions at 2000 and 2500 rpm against loading variations, as a new solution to overcome the lack information on the effect of various loads on diesel-hydrogen dual fuel. the thermal engine efficiency, nox and smoke emissions are the main topics presented in this paper. the information presented in this paper will be beneficial for researchers, academics and practitioners who will utilize hydrogen for dual-fuel applications on conventional diesel engines with minimum modification. ii. materials and methods a. engine testing preparation the experiment was conducted by using an engine test bed composed of a single cylinder diesel engine coupled with an eddy-current dynamometer, the fuel balance measurement, nox meter, smoke meter, and pressure and temperature sensors. the eddy current dynamometer was used to adjust and measure engine speed and loads. meanwhile, fuel consumption was measured by using the fuel balance measurement system, and the intake air flow was measured with a hotwire anemometer. the combination of a pressure transducer, crank-angle sensor, and a data acquisition system was used to obtain the data inside of engine cylinder during the experiment. the engine specifications are shown in table 1, and the engine testing arrangement can be seen in figure 1. b. testing procedure the engine tests were carried out with two engine speeds, namely 2000 and 2500 rpm fueled with pure diesel and compared with diesel mixed with hydrogen addition. engine loading was varied from 0, 5, 10, 20, and 25 nm. the characteristics of pure diesel and hydrogen refer to bari and mohammad [18] is shown in table 2. hydrogen was inserted into the combustion chamber by the fumigation method using a small tube directly into the inlet manifold with a distance of 50 cm table 1. engine specifications parameters units engine type naturally aspirated, di-ci, 4 stroke, 2 valves number of cylinder / configuration 1 / vertical displacement volume 667 cm3 bore x stroke 100 mm × 85 mm compression ratio 20 : 1 maximum torque 28 nm at 2000 rpm maximum power 11 kw at 3000 rpm y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 51 from the base of the intake manifold. the hydrogen was set at a constant flow around 10 litres/minute with a pressure of 0.5 bar. furthermore, some parameters in each condition including indicated mean effective pressure (imep), fuel consumption, air flow rate, oil temperature, exhaust gas temperature, nox and smoke emission values were measured. iii. results and discussions a. improvement of thermal efficiency thermal efficiency states the ratio between the powers produced to the amount of fuel needed for a certain period of engine operation. it is one of the factors to analyze the performance of the internal combustion engine. although this paper also focuses on the discussion of engine emissions, in this case, it is worth mentioning a brief effect of hydrogen addition to thermal efficiency closely related to fuel consumption. figures 2 and figure 3 show the thermal efficiency (brake thermal efficiency, bte) of the ci engine based on the loads variation at 2000, and 2500 rpm, refer to the diesel consumption only. the occurred thermal efficiency patterns for both 2000 and 2500 rpm shows similarities. at 2000 rpm the addition of hydrogen causes an increase in thermal efficiency at every load variation as well as at 2500 rpm. this condition happens because a portion of diesel fuel is replaced by figure 1. engine testing diagram table 2. characteristics of diesel and hydrogen parameters unit diesel hydrogen density kg/m3 840 0.082 caloric value mj/kg 42.7 119.81 ignition speed m/s 0.3 2.70 autoignition temperature °c 280 585 carbon residue % 0.1 0.00 y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 52 hydrogen which has a high ignition speed (around 3.24 to 4.40 ms-1). thus, the hydrogen causes the combustion process in the engine combustion chamber occurred very rapidly. however, the exact amount of the consumed hydrogen cannot be measured. the amount of consumed hydrogen can be predicted only by the discrepancies of thermal efficiency between engine fueled with pure diesel fuel and hydrogen added diesel. the higher speed of the combustion process will produce greater combustion energy that can improve the performance of the diesel engine. referring to the results of adnan [17], the addition of certain amount of hydrogen, in the form of gas fuel, to a diesel engine mixed with air gives a significant impact on the cylinder load during compression and power during a combustion explosion. b. nox reduction figure 4 and figure 5 show nox emissions against loads variation of the ci engines at 2000 and 2500 rpm. both charts show the same pattern, where at low load, nox values are decreases in diesel with the addition of hydrogen. at 2000 rpm of engine speed, nox values are decreases with the loads variation from 0, 5, 10, 15, and 20 nm by 16%, 33%, 39%, 37%, and 22%, respectively. meanwhile, in the load value around 25 nm, it tends to have no effect of decreasing on nox value of the diesel engine with the addition of hydrogen. at engine speed around 2500 rpm, the nox reduction pattern still occurs at the variation of the load from 0, 5, 10, 15, and 20 nm by 35%, 40%, 44%, 35%, and 27%, respectively. also, for 2500 rpm, at an engine load around 25 nm, the increase in nox value occurs by 7%. this nox reduction pattern is happened because at low loads there is an increase in the hydrogen fuel fraction. therefore, the nox reduce significantly. this condition in line with the results of the research conducted by miyamoto [19]. c. smoke emissions reduction the various values of smoke density for emissions test are shown in figures 6 and figure 7. figure 6 shows smoke history on the loads variation of diesel figure 2. engine thermal efficiency at 2000 rpm figure 3. engine thermal efficiency at 2500 rpm y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 53 and diesel engines with hydrogen at 2000 rpm and figure 7 is at 2500 rpm. by analyzing the two images, it can be observed that diesel-hydrogen dual fuel operation is a very potent strategy to reduce the massive smoke emissions of ci engines. for diesel-hydrogen dual fuel operations with engine speed around 2000 and 2500 rpm, it can be revealed that the smoke emissions are reduced up to 0% and even minus at a low load from 20 nm downwards. in other words, diesel-hydrogen dual fuel operations produce smokeless combustion. meanwhile, at engine load. meanwhile, at engine load around 25 nm, both for engine speed around 2000 and 2500 rpm, smoke emissions began to appear. the decrease in smoke figure 4. nox at 2000 rpm figure 5. nox at 2500 rpm figure 6. smoke at 2000 rpm y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 54 value was happened because of the partial replacement of diesel fuel by hydrogen inside the combustion process. based on table 2, it is known that hydrogen addition in the combustion produces the main combustion residue in the form of water vapor only, and does not form any particulates. this is due to the absence of carbon atoms in hydrogen resulting in a low smoke percentage [15]. iv. conclusion the performance and emissions tests on 667 cm3, single cylinder diesel engines have been carried out without or with the addition of hydrogen. addition of hydrogen is carried out by inserting it through the intake manifold. from the performance test, it is obtained an increase in the value of thermal efficiency by adding hydrogen. meanwhile, from emission tests with the addition of hydrogen at engine speed around 2000 and 2500 rpm, the nox value decreases from 16 to 43% in low load condition. furthermore, the smoke emissions content is very clean or smokeless at 2000 and 2500 rpm with low load condition by a 0% of smoke value. this experimental work and extensive investigation show some valuable insight and new ideas. however, it is necessary to conduct a further study such as the application of various injection timing of diesel fuel to optimize the efficiency and emissions characteristics of the ci engine operated in dual-fueled with diesel-hydrogen. acknowledgment this research was supported by the research centre for electrical power and mechatronicsindonesian institute of sciences (lipi) in collaboration with smart powertrain laboratory-university of ulsan, south korea. yanuandri putrasari acknowledges support from the program for research and innovation in science and technology (riset-pro) ref. no: 61/riset-pro/fgs/iii/2017, indonesian ministry of research, technology and higher education. references [1] m. i. devi, k. ismail, and a. nur, “techno-economic analysis of biogas utilization as an alternative fuel,” journal of mechatronics, electrical power, and vehicular technology, vol. 5, no. 1, p. 51, jul. 2014. [2] y. putrasari, h. abimanyu, a. praptijanto, a. nur, y. irawan, and s. p. simanungkalit, “experimental investigation of 2nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palm on performance and exhaust emission of si engine,” journal of mechatronics, electrical power, and vehicular technology, vol. 5, no. 1, p. 9, jul. 2014. [3] r. fajar and h. setiapraja, “the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation,” journal of mechatronics, electrical power, and vehicular technology, vol. 5, no. 1, p. 59, jul. 2014. [4] t. tsujimura and y. suzuki, “the utilization of hydrogen in hydrogen/diesel dual fuel engine,” international journal of hydrogen energy, vol. 42, no. 19, pp. 14019–14029, may 2017. [5] m. kumar, t. tsujimura, and y. suzuki, “nox model development and validation with diesel and hydrogen/diesel dual-fuel system on diesel engine,” energy, vol. 145, pp. 496– 506, feb. 2018. [6] p. dimitriou, m. kumar, t. tsujimura, and y. suzuki, “combustion and emission characteristics of a hydrogen-diesel dual-fuel engine,” international journal of hydrogen energy, vol. 43, no. 29, pp. 13605–13617, jul. 2018. [7] c. yuan, c. han, y. liu, y. he, y. shao, and x. jian, “effect of hydrogen addition on the combustion and emission of a diesel free-piston engine,” international journal of hydrogen energy, vol. 43, no. 29, pp. 13583–13593, jul. 2018.. [8] p. dimitriou and t. tsujimura, “a review of hydrogen as a compression ignition engine fuel,” international journal of hydrogen energy, vol. 42, no. 38, pp. 24470–24486, september 2017. [9] m. o. hamdan, m. y. e. selim, s.-a. b. al-omari, and e. elnajjar, “hydrogen supplement co-combustion with diesel in compression ignition engine,” renewable energy, vol. 82, pp. 54–60, oct. 2015. [10] p. sharma and a. dhar, “compression ratio influence on combustion and emissions characteristic of hydrogen diesel dual fuel ci engine: numerical study,” fuel, vol. 222, pp. 852– 858, jun. 2018. [11] h. koten, “hydrogen effects on the diesel engine performance and emissions,” international journal of hydrogen energy, vol. 43, no. 22, pp. 10511–10519, may 2018. [12] s. szwaja and k. grab-rogalinski, “hydrogen combustion in a compression ignition diesel engine,” international journal of hydrogen energy, vol. 34, no. 10, pp. 4413–4421, may 2009. [13] a. çalık, “determination of vibration characteristics of a compression ignition engine operated by hydrogen enriched figure 7. smoke at 2500 rpm https://doi.org/10.14203/j.mev.2014.v5.51-58 https://doi.org/10.14203/j.mev.2014.v5.51-58 https://doi.org/10.14203/j.mev.2014.v5.51-58 https://doi.org/10.14203/j.mev.2014.v5.51-58 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.9-16 https://doi.org/10.14203/j.mev.2014.v5.59-66 https://doi.org/10.14203/j.mev.2014.v5.59-66 https://doi.org/10.14203/j.mev.2014.v5.59-66 https://doi.org/10.14203/j.mev.2014.v5.59-66 https://doi.org/10.14203/j.mev.2014.v5.59-66 https://doi.org/10.1016/j.ijhydene.2017.01.152 https://doi.org/10.1016/j.ijhydene.2017.01.152 https://doi.org/10.1016/j.ijhydene.2017.01.152 https://doi.org/10.1016/j.ijhydene.2017.01.152 https://doi.org/10.1016/j.energy.2017.12.148 https://doi.org/10.1016/j.energy.2017.12.148 https://doi.org/10.1016/j.energy.2017.12.148 https://doi.org/10.1016/j.energy.2017.12.148 https://doi.org/10.1016/j.ijhydene.2018.05.062 https://doi.org/10.1016/j.ijhydene.2018.05.062 https://doi.org/10.1016/j.ijhydene.2018.05.062 https://doi.org/10.1016/j.ijhydene.2018.05.062 https://doi.org/10.1016/j.ijhydene.2018.05.038 https://doi.org/10.1016/j.ijhydene.2018.05.038 https://doi.org/10.1016/j.ijhydene.2018.05.038 https://doi.org/10.1016/j.ijhydene.2018.05.038 https://doi.org/10.1016/j.ijhydene.2017.07.232 https://doi.org/10.1016/j.ijhydene.2017.07.232 https://doi.org/10.1016/j.ijhydene.2017.07.232 https://doi.org/10.1016/j.ijhydene.2017.07.232 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.renene.2014.08.019 https://doi.org/10.1016/j.fuel.2018.02.108 https://doi.org/10.1016/j.fuel.2018.02.108 https://doi.org/10.1016/j.fuel.2018.02.108 https://doi.org/10.1016/j.fuel.2018.02.108 https://doi.org/10.1016/j.ijhydene.2018.04.146 https://doi.org/10.1016/j.ijhydene.2018.04.146 https://doi.org/10.1016/j.ijhydene.2018.04.146 https://doi.org/10.1016/j.ijhydene.2009.03.020 https://doi.org/10.1016/j.ijhydene.2009.03.020 https://doi.org/10.1016/j.ijhydene.2009.03.020 https://doi.org/10.1016/j.fuel.2018.05.053 https://doi.org/10.1016/j.fuel.2018.05.053 y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 55 diesel and biodiesel fuels,” fuel, vol. 230, pp. 355–358, oct. 2018. [14] s. javed, r. u. baig, and y. v. v. s. murthy, “study on noise in a hydrogen dual-fuelled zinc-oxide nanoparticle blended biodiesel engine and the development of an artificial neural network model,” energy, vol. 160, pp. 774–782, oct. 2018. [15] n. saravanan, g. nagarajan, g. sanjay, c. dhanasekaran, and k. m. kalaiselvan, “combustion analysis on a di diesel engine with hydrogen in dual fuel mode,” fuel, vol. 87, no. 17–18, pp. 3591–3599, dec. 2008. [16] l. das, “hydrogen engine: research and development (r&d) programmes in indian institute of technology (iit), delhi,” international journal of hydrogen energy, vol. 27, no. 9, pp. 953–965, sep. 2002. [17] r. adnan, h. h. masjuki, and t. m. i. mahlia, “an experimental investigation of unmodified di diesel engine with hydrogen addition,” in proceeding of 2009 3rd international conference on energy and environment (icee), 2009, pp. 45– 49. [18] s. bari and m. mohammad esmaeil, “effect of h2/o2 addition in increasing the thermal efficiency of a diesel engine,” fuel, vol. 89, no. 2, pp. 378–383, feb. 2010. [19] t. miyamoto, h. hasegawa, m. mikami, n. kojima, h. kabashima, and y. urata, “effect of hydrogen addition to intake gas on combustion and exhaust emission characteristics of a diesel engine,” international journal of hydrogen energy, vol. 36, no. 20, pp. 13138–13149, oct. 2011. https://doi.org/10.1016/j.fuel.2018.05.053 https://doi.org/10.1016/j.fuel.2018.05.053 https://doi.org/10.1016/j.energy.2018.07.041 https://doi.org/10.1016/j.energy.2018.07.041 https://doi.org/10.1016/j.energy.2018.07.041 https://doi.org/10.1016/j.energy.2018.07.041 https://doi.org/10.1016/j.energy.2018.07.041 https://doi.org/10.1016/j.fuel.2008.07.011 https://doi.org/10.1016/j.fuel.2008.07.011 https://doi.org/10.1016/j.fuel.2008.07.011 https://doi.org/10.1016/j.fuel.2008.07.011 https://doi.org/10.1016/s0360-3199(01)00178-1 https://doi.org/10.1016/s0360-3199(01)00178-1 https://doi.org/10.1016/s0360-3199(01)00178-1 https://doi.org/10.1016/s0360-3199(01)00178-1 https://doi.org/10.1109/iceenviron.2009.5398672 https://doi.org/10.1109/iceenviron.2009.5398672 https://doi.org/10.1109/iceenviron.2009.5398672 https://doi.org/10.1109/iceenviron.2009.5398672 https://doi.org/10.1109/iceenviron.2009.5398672 https://doi.org/10.1016/j.fuel.2009.08.030 https://doi.org/10.1016/j.fuel.2009.08.030 https://doi.org/10.1016/j.fuel.2009.08.030 https://doi.org/10.1016/j.ijhydene.2011.06.144 https://doi.org/10.1016/j.ijhydene.2011.06.144 https://doi.org/10.1016/j.ijhydene.2011.06.144 https://doi.org/10.1016/j.ijhydene.2011.06.144 https://doi.org/10.1016/j.ijhydene.2011.06.144 y. putrasari et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 49–56 56 this page is intentionally left blank mev journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 1– 6 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 2088-6985 / 2087-3379 ©2019 research centre for electrical power an d mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. sensorless-bldc motor speed control with ensemble kalman filter and neural network muhammad rif’an a, *, feri yusivar b, benyamin kusumoputro b a department of electrical engineering, universitas negeri jakarta rawamangun muka, jakarta, 13220, indonesia b department of electrical engineering, universitas indonesia kampus baru ui, depok, 16424, indonesia received 6 august 2018; accepted 14 march 2019; published online 17 december 2019 abstract the use of sensorless technology at bldc is mainly to improve operational reliability and play a role for wider use of bldc motors in the future. this research aims to predict load changes and to improve the accuracy of estimation results of sensorlessbldc. in this paper, a new filtering algorithm is proposed for sensorless brushless dc motor based on ensemble kalman filter (enkf) and neural network. the proposed enkf algorithm is used to estimate speed and rotor position, while neural network is used to estimate the disturbance by simulation. the proposed algorithm requires only the terminal voltage and the current of three phases for estimated speed and disturbance. a model of non-linear systems is carried out for simulation. variations in disturbances such as external mechanical loads are given for testing the performance of the proposed algorithm. the experimental results show that the proposed algorithm has sufficient control with error speed of 3 % in a disturbance of 50 % of the rated-torque. simulation results show that the speed can be tracked and adjusted accordingly either by disturbances or the presence of disturbances. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: ensemble kalman filter; neural network; sensorless; brushless dc motor. i. introduction brushless dc (bldc) motor is a direct current motor which is electronically controlled because it does not use a brush. currently, bldc motors have been global utilization in many manufacturing because of their superior peculiars, like big starting torque, great efficiency, low noise during function and high ability to withstand wear, pressure, or damage. these advantages have made bldc motor to be widely used in electric vehicles, computers (hard disks, fans) and medical equipment [1][2][3]. the electric commutator on bldc motor uses an inverter and assists the position sensor to catch the position of the rotor as a reference for proper current change. this is done in the line of the commutator function and the use of brushes on dc motors. the bldc rotor rotation is a representation of the rotor position measured by the position sensor (usually using a hall sensor) and generally uses three hall sensors to get a perfect rotation. however, the installation of the hall sensor causes several problems when adding sensors that can reduce the reliability and robustness of the system, difficult installation and maintenance, and increase the physical size and overall costs [4]. to overcome this problem, in recent years, many researchers have focused on sensorless bldc controls. the use of sensorless technology at bldc is mainly to improve operational reliability and play a role for wider use of bldc motors in the future. one method that is widely used in sensorless techniques is backemf. in principle, this method detects back-emf bldcm and is used as a commutation point in accordance with the liaison between back-emf and rotor position. many back-emf methods have been developed such as the third harmonic from back-emf sensing [5][6], back-emf integration [7], line to line voltage sensing [8][9], filtering phase [10][11] and terminal voltage sensing [12][13]. however, all of these methods have problems at low speeds because the back-emf amplitude is too small to be detected. the other sensorless method is flux calculation method [14], but it also has problem of accumulating * correspon ding author. tel: +62 815 8165 545 e-mail: m.rifan@unj.ac.id https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.1-6&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. rif’an et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 1–6 2 integration errors at low speeds, as the previously proposed method. this method also requires considerably computing costs and is susceptible to parameter variations, so this complicated algorithm requires costly floating point processors. another sensorless method developed by researchers is the use of observer functions. meanwhile, a popular type of observer used to approximate the bldc rotor position is the extended kalman filter (ekf) [15]. however, this method has several disadvantages, including complicated calculations from the jacobian matrix, only first order-accuracy, etc. to cover the drawback of the ekf algorithm, especially in the use of jacobian matrix, enkf algorithm has been developed [16]. in predicting rotor position, the enkf algorithm no longer uses jacobian matrix but uses ensemble integration method or better known as the monte carlo algorithm. meanwhile, the prediction of mathematical problem used in the enkf algorithm is fokker-planck mathematical problem. related applications of enkf have been reported in [16] where the use of observers as predictors of the bldc rotor position, a mathematical model from bldc is needed. however, the bldc motor drive has a nonlinear nature so that it is quite difficult to get accurate mathematical models for motors by using conventional techniques. in addition, with increasing usage period and difficulty in calculating non-linear parameters, motor properties are often unknown to the changes in load, disturbance, point of saturation, and bldc parameters. unlike [16] which has not included fluctuation in load on the bldc, this paper uses neural network algorithm to predict load changes based on current changes that occur in the bldc and is used in the enkf algorithm to improve the accuracy of estimation results. the neural network is used because of its ability to model nonlinear systems. the research was conducted by simulation of algorithm calculation using matlab. simulation results show that the speed can be tracked and adjusted accordingly either by disturbances or the presence of disturbances. ii. materials and methods a. mathematical model of the bldc in sensorless mode the bldc motor is modelled by approaching two main numerical conditions. one numerical condition is for electricity and the other one is for mechanical parts. the specifics of numerical conditions are given in [15]. four state variables in these equations are motor shaft speed and motor current, i.e. ia, ib, and ic. the motor's mechanical, electrical, and load equations are combined as a matrix form as follows: 𝑑 𝑑𝑡 [ 𝑖𝑎 𝑖𝑏 𝑖𝑐  ] = [ 𝐴11 0 0 𝐴22 0 𝐴14 0 𝐴24 0 0 𝐴41 𝐴42 𝐴33 𝐴34 𝐴43 𝐴44 ][ 𝑖𝑎 𝑖𝑏 𝑖𝑐  ]+ [ 𝐵11 0 0 𝐵22 0 0 0 0 0 0 0 0 𝐵33 0 0 𝐵44 ][ 𝑣𝑎 𝑣𝑏 𝑣𝑐 𝑇𝑚 ] (1) with 𝐴11 = 𝐴22 = 𝐴33 = −𝑅𝑠 𝐿𝑠 𝐴14 = − 𝜆𝑚 𝐿𝑠 𝐹(𝜃𝑒) 𝐴24 = − 𝜆𝑚 𝐿𝑠 𝐹 (𝜃𝑒 + 4𝜋 3 ) 𝐴34 = − 𝜆𝑚 𝐿𝑠 𝐹 (𝜃𝑒 − 4𝜋 3 ) 𝐴41 = 𝜆𝑚 𝐽 𝐺(𝜃𝑒) 𝐴42 = 𝜆𝑚 𝐽 𝐺 (𝜃𝑒 + 4𝜋 3 ) 𝐴43 = 𝜆𝑚 𝐽 𝐺 (𝜃𝑒 − 4𝜋 3 ) 𝐴44 = − 𝐵 𝐽 𝐵11 = 𝐵22 = 𝐵33 = 1 𝐿𝑠 𝐵44 = 1 𝐽 where v𝑎 is the phase a terminal voltage, the phase resistance, the phase current and the phase inductance are rs, i𝑎, and ls, respectively. in particular, for phase b and c, we have similar voltage equations. j is inertia, b is friction coefficient, tm is load torque, and m is magnet flux linkage of the stator winding. the nonlinear function g(𝜃) can be described as follows: 𝐺(𝜃) = { 6 𝜋 𝜃 0 < 𝜃 ≤ 𝜋 6 1 𝜋 6 < 𝜃 ≤ 5𝜋 6 − 6 𝜋 (𝜃 − 𝜋) 5𝜋 6 < 𝜃 ≤ 7𝜋 6 −1 6 𝜋 (𝜃 − 2𝜋) 7𝜋 6 < 𝜃 ≤ 11𝜋 6 11𝜋 6 < 𝜃 ≤ 2𝜋 (2) the main idea of an estimation system in sensorless mode is to use a mathematical model derived from the bldc to calculate the estimated value of the output parameters from the measured input parameters. figure 1 shows the system operation block diagram of a bldc sensorless speed control motor using estimator. the extended kalman filter (ekf) is one type of common estimator, which is used to estimate the bldc motor's system state variables and stator resistance immediately using the actual voltages and currents derived from the bldc motor's mathematical model. in some cases, there is likewise some constraint in using ekf as an observer, for example, the characteristics of ekf that must be executed as first request accuracy, high multifaceted computing to calculate the jacobian matrix and its covariance matrix. for example in equation (1), mathematic model of the bldc motor need tm as input whereas, in reality, this load (tm) can not be measured directly. meanwhile, in sensorless mode, the algorithm involves only the voltage and current bldc motor terminals and does not involve any tm, thus, if there is any tm, it can cause an error of the estimate because one of the input is ignored. figure 2 shows the estimation error. in two seconds, the load changes from 0 to 2 nm and it can be seen that the estimation experiences an error. therefore, we proposed the m. rif’an et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 1–6 3 enkf and neural network algorithm as part of predicting the amount of tm by changes in voltage and current that occurs in this paper. b. enkf and neural network algorithm figure 3 shows the enkf and neural network block diagram of the framework activity of a speed control sensorless bldc motor. the enkf as an estimator reckons, the rotor speed () and the rotor position (). the rotor speed (), which is in a sensorless system is provided from the estimator and compared with the speed reference (ref) to produce the speed error signal (error). the resulting error is given to the controller. the controller will calculate this speed error signal (e) into a control command (u). then, the voltage and current generated by the inverter is measured and used as input to block the neural network (nn) to estimate the tm. afterwards, the measured voltage and current and the estimated tm resulted from the neural network are used as input to enkf which ultimately results in the prediction of motor position and speed. 1) ensemble kalman filter the enkf estimation system uses ensemble integration methods to solve the fokker-planck equation or also referred to as suboptimal where error statistics are predicted using monte carlo. in updating the filter gain �̂�𝑘, the enkf system does not involve estimating nonlinear functions f(x, u) and h(x). this is what distinguishes the ekf system in general, so that large computation in calculating the jacobians of f(x, u) and h(x) is not used anymore in the enkf system. the beginning stage for the enkf estimation system as particle filters is the selection of a set of sample points, which is an ensemble of state estimations that captures the initial probability distribution of the state. these state estimation points are then engendered through the true nonlinear system, with the goal that the likelihood density function of the actual state can be approximated by the ensemble of the estimation system (enkf). the enkf estimation method consists of three stages. the first step is called the forecast step, where the representation of the system’s error statistics is gained by assuming that an ensemble of q forecast state estimates with random sample errors is available at time k. we denote this ensemble as 𝑋𝑘 𝑓 ∈ 𝑅𝑛𝑥𝑞 where 𝑋𝑘 𝑓 ≜ (𝑥𝑘 𝑓1,𝑥𝑘 𝑓2,⋯,𝑥 𝑘 𝑓𝑞 ) (3) with the subscript fi refers to the i-th forecast ensemble member. then, the ensemble mean �̅�𝑘 𝑓 ∈ 𝑅𝑛 is defined by �̅�𝑘 𝑓 ≜ 1 𝑞 ∑ 𝑥𝑘 𝑓𝑖𝑞 𝑖=1 (4) since the true state xk is unknown, we approximate (4) by using the ensemble members. we define the figure 1. block diagram of sen sorless bldc motor figure 2. performan ce curves of speed and load change before using neural network m. rif’an et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 1–6 4 ensemble error matrix 𝐸𝑘 𝑓 ∈ 𝑅𝑛𝑥𝑞 around the ensemble mean by 𝐸𝑘 𝑓 ≜ [𝑥𝑘 𝑓1 − �̅�𝑘 𝑓 ⋯𝑥 𝑘 𝑓𝑞 − �̅�𝑘 𝑓 ] (5) and the ensemble of the output error eyk a ∈ rpxq by 𝐸𝑦𝑘 𝑎 ≜ [𝑦𝑘 𝑓1 − �̅�𝑘 𝑓 ⋯𝑦 𝑘 𝑓𝑞 − �̅�𝑘 𝑓 ] (6) we approximate the 𝑃𝑘 𝑓 by �̂�𝑘 𝑓 , the 𝑃𝑥𝑦𝑘 𝑓 by �̂�𝑥𝑦𝑘 𝑓 , and the 𝑃𝑦𝑦𝑘 𝑓 by �̂�𝑦𝑦𝑘 𝑓 , respectively, where �̂�𝑘 𝑓 ≜ 1 𝑞−1 𝐸𝑘 𝑓 (𝐸𝑦𝑘 𝑓 ) 𝑇 , �̂�𝑦𝑦𝑘 𝑓 ≜ 1 𝑞−1 𝐸𝑦𝑘 𝑓 (𝐸𝑦𝑘 𝑓 ) 𝑇 (7) therefore, we construe the forecast ensemble as the best forecast estimation of the state, while the distribution of the ensemble members around the average as the fault between the best estimation and the actual state. the second step is the analysis step. the enkf carries out an ensemble of q parallel data assimilation cycles to obtain the state's analysis estimation, where for i = 1, 2, 3, …, q 𝑥𝑘 𝑎𝑖 = 𝑥𝑘 𝑓𝑖 + �̂�𝑘 (𝑦𝑘 𝑖 − ℎ(𝑥𝑘 𝑓𝑖)) (8) the perturbed observations yk i are given b 𝑦𝑘 𝑖 = 𝑦𝑘 + 𝑣𝑘 𝑖 (9) where 𝑣𝑘 𝑖 is a zero-mean disordered variable with a normal distribution and covariance rk. the sample fault of the covariance matrix computed from the 𝑣𝑘 𝑖 converges to rk as q →  . we approximate the analysis of the fault of the covariance matrices 𝑃𝑘 𝑎 by �̂�𝑘 𝑎, where �̂�𝑘 𝑎 ≜ 1 𝑞−1 𝐸𝑘 𝑎𝐸𝑘 𝑎𝑇 (10) and 𝐸𝑘 𝑎 is defined by with 𝑥𝑘 𝑓𝑖 replaced by 𝑥𝑘 𝑎𝑖 and �̅�𝑘 𝑓 replaced by the mean of the analysis estimate ensemble members. we use the classical kalman filter gain expression and the approximations of the error covariances to determine the filter gain by �̂�𝑘 by 𝑥𝑘+1 𝑓𝑖 = 𝑓(𝑥𝑘 𝑎𝑖, 𝑢𝑘)+ 𝑤𝑘 𝑖 (11) the last step is the prediction of error statistics in the forecast step: 𝑥𝑘+1 𝑓𝑖 = 𝑓(𝑥𝑘 𝑎𝑖, 𝑢𝑘)+ 𝑤𝑘 𝑖 (12) where the values are 𝑤𝑘 𝑖 sampled from a normal distribution with average zero and covariance 𝑄𝑘. the sample error covariance matrix computed from the 𝑤𝑘 𝑖 converges to 𝑄𝑘 as 𝑞 → . finally, we summarize the analysis and forecast steps. analysis steps were included equation (13) to equation (15). �̂�𝑘 = �̂�𝑥𝑦𝑘 𝑓 (�̂�𝑦𝑦𝑘 𝑓 ) −1 (13) 𝑥𝑘 𝑎𝑖 = 𝑥𝑘 𝑓𝑖 + �̂�𝑘 (𝑦𝑘 𝑖 − ℎ(𝑥𝑘 𝑓𝑖)) (14) �̅�𝑘 𝑎 = 1 𝑞 ∑ 𝑥𝑘 𝑎𝑖𝑞 𝑖=1 (15) forecast steps were included equation (16) to equation (20). 𝑥𝑘+1 𝑓𝑖 = 𝑓(𝑥𝑘 𝑎𝑖, 𝑢𝑘)+ 𝑤𝑘 𝑖 (16) �̅�𝑘+1 𝑓 = 1 𝑞 ∑ 𝑥𝑘+1 𝑓𝑖𝑞 𝑖=1 (17) 𝐸𝑘+1 𝑓 = [𝑥𝑘+1 𝑓1 − �̅�𝑘+1 𝑓 ⋯𝑥 𝑘+1 𝑓𝑞 − �̅�𝑘+1 𝑓 ] (18) 𝐸𝑦𝑘 𝑎 ≜ [𝑦𝑘 𝑓1 − �̅�𝑘 𝑓 ⋯𝑦 𝑘 𝑓𝑞 − �̅�𝑘 𝑓 ] (19) �̂�𝑥𝑦𝑘 𝑓 = 1 𝑞−1 𝐸𝑘 𝑓 (𝐸𝑦𝑘 𝑓 ) 𝑇 , �̂�𝑦𝑦𝑘 𝑓 = 1 𝑞−1 𝐸𝑦𝑘 𝑓 (𝐸𝑦𝑘 𝑓 ) 𝑇 (20) 2) neural-network algorithm the new modelling tool for a very well-known estimate is artificial neural networks, specifically used for complex and non-linear systems. artificial neural networks do not require knowledge of the internal work processes of the system to be modelled so that they are usually used as black box models. but they only need learning from the input-output vectors produced by the experiment which are commonly called learning sets and represent the system for the model. rumelhart proposed a back propagation learning method for the neural network learning process [17]. in this method, errors from the output of neural networks to learning data are formed into error functions and processed to a minimum. in the process of minimizing the function of this error, network parameters are updated with the principle opposite to the error function gradient. in this paper, we use various load as inputs and current and voltage as outputs for data learning set. figure 4 shows the neural network test result. this figure clearly shows that the estimated value of the neural network is in accordance with the actual value of the mean-sum-error (mse) is 5.7311 × 10-5. figure 3. block diagram of enkfneural network sensorless bldcm m. rif’an et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 1–6 5 iii. results and discussions in this section, we present a sensorless velocity estimation and control system and simulation using matlab. the parameters of the bldc motor are set with the following parameter, i.e. the stator resistance 𝑅s = 79 ω, the inductance of the stator ls =12×10-3 h, each permanent magnet flux maximum phase winding 𝜑𝑚 = 0.0271 wb, the inertia 𝐽 = 0.48 ×10-3 kg.m2, the viscous friction coefficient 𝐵𝑣 is zero, poles of the permanent magnet 𝑝 = 4, rated-torque 0.125 nm, simulation step length 𝑇 = 1 × 10-4 s, 𝑥0 = [0 0 0 0 0]𝑇 and number of ensemble is 10. based on mathematical equation (1) to get the prediction ω, the data needed are ia, ib, ic, ω, va, vb, vc, and tm at the previous time. the prediction process is done by using the enkf algorithm. in this case, ia, ib, ic, va, vb, and vc, are obtained from direct measurements and quickly sampling 10 times to get 10 ensembles, while ω is the initial position and tm is the estimated result of the neural network part. to substantiate the estimated performance of our algorithm, two treatments are performed to verify the performance of the velocity and the modification load. in this example, the reference speed modifies from 1600 𝑟𝑝𝑚 to 2400 𝑟𝑝𝑚 at time 𝑡 = 1 𝑠. then, the load torque tm = 0.07 𝑁𝑚 is added to this motor at figure 4. performan ce of the neural network epoch e rr o r figure 5. performan ce curves of speed and load change after using neural network figure 6. performan ce of rotor position of speed and load chan ge m. rif’an et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 1–6 6 time 𝑡 = 2 𝑠. the experiment results (i.e. the performance curves) are obtained and presented in figure 5 and figure 6. from figure 5, we can see that when the reference speed become different or the load become different, the evaluated and the real speed are nearly the same. the error between the estimated speed and the actual rate is approximately 3 %. the ripple cannot be eliminated due to the interaction of the estimated enkf and neural network but within an acceptable tolerance of 3 %. the designed enkf and neural network algorithm can be concluded that it is very effective when the speed or torque changes suddenly. from figure 6, it can be seen the evaluated and the real rotor position are almost identical. and the error is approximately 2 electrical angle confirming that the motor can operate normally with a small torque ripple. the results of the experiments show the efficacy of our filtering algorithm. conclusion in this paper, to operate a sensorless bldc motor, we developed a new estimation system for rotor speed and rotor position speed using an ensemble kalman filter (enkf) and neural network. it is clear that the precise estimation performance can be obtained from the simulation results and the efficiency of our designed algorithm can be illustrated. with a disturbance of 50 % of the rated-torque, the proposed algorithm is able to maintain motor speed with a speed error of 3 % and error estimated position is approximately 2 electrical angle. additionally, the sensorless bldc motor can also be precisely controlled according to the designed algorithm of enkf and neural network. acknowledgement the authors would like to thank all members of computational intelligence and intelligent system, department of electrical engineering, universitas indonesia, which have already supported the research. the valuable comments from the reviewers are also very much appreciated. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not -for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] a. ulasyar, h. sheh zad and a. zohaib, “intelligent speed controller design for brushless dc motor,” 2018 international conference on frontiers of information technology (fit) , islamabad, pakistan, pp. 19-23, 2018. [2] l. ch u et al., “research on control strategies of an open-end winding permanent magnet synchronous drivin g motor (owpmsm)-equipped dual inverter with a switchable winding mode for electric vehicles,” energies, vol. 10, no. 5, pp. 616, 2017. [3] j. h. r. bo long, shin teak lim, and k. t. chong, “energyregenerative braking control of electric vehicles using threephase brushless direct-current motors,” energies, vol. 7, pp. 99–114, 2014. [4] s. a. kh. mozaffari niapour, m. tabarraie, and m. r. feyzi, “a new robust speed-sen sorless control strategy for highperformance brushless dc motor drives with reduced torque ripple,” control engineering practice, volume 24, pages 42-54, 2014. [5] o. imoru and j. tsado, “modelling of an electronically commutated (brushless dc) motor drives with back-emf sensing,” 2012 16th ieee mediterranean electrotechnical conference, yasmine hammamet, pp. 828-831, 2012. [6] m. mariano, k. scicluna , and j. scerri, "mo delling of a sen sorless rotor flux oriented bldc machine,” 2017 19th international conference on electrical drives and power electronics (edpe), dubrovnik, pp. 194-199, 2017. [7] c. s. joice, s. r. paranjothi and v. j. s. kumar, “digital control strategy for four quadrant operation of three phase bldc motor with load variation s,” in ieee transactions on in dustrial informatics, vol. 9, no. 2, pp. 974-982, 2013. [8] g. liu et al., “sensorless control for high-speed brushless dc motor based on the line-to-line back emf,” in ieee transactions on power electronics, vol. 31, no. 7, pp. 4669-4683, 2016. [9] t. w. ch un et al., “sensorless control of bldc motor drive for an automotive fuel pump using a hysteresis comparator,” ieee trans. power electron., vol. 29, no. 3, pp. 1382–1391, 2014. [10] g. j. su and j. w. mckeever, “low-cost sensorless control of brushless dc motors with improved speed ran ge,” ieee trans. power electron ., vol. 19, no.2, pp. 296–302, 2004. [11] y. y wu et al., “position sensorless control based on coordinate transformation for brushless dc motor drives,” ieee trans. power electron ., vol. 25, no. 9, pp. 2365–2371, 2010.r. m. pindoriya et al., “fpga based digital control technique for bldc motor drive,” 2018 ieee power & energy society general meeting (pesgm), portland, or, pp. 1-5, 2018. [12] r. m. pindoriya, a . k. mishra, b. s. rajpurohit and r. kumar, “fpga based digital control technique for bldc motor drive,” 2018 ieee power & energy society general meeting (pesgm) , portland, or, pp. 1-5, 2018. [13] u. k. soni and r. k. tripathi, “novel back emf zero difference point detection based sensorless technique for bldc motor,” 2017 ieee international conference on in dustrial technology (icit), toronto, on, pp. 330-335, 2017. [14] tae-hyung kim, hyung-woo lee, and m. eh sani, “state of the art and future tren ds in position sen sorless brushless dc motor/generator drives, industrial electronics society,” iecon 2005. 31st annual conference of ieee, pp.8, 6-10 nov., 2005. [15] m. rif’an , f. yusivar, and b. kusumoputro, “design of extended kalman filter speed estimator and single neuron-fuzzy speed controller for sensorless brushless dc motor,” journal of telecommunication , electronic an d computer en gineering (jtec), vol. 10, no. 1-5, 2018. [16] m. rif’an, f. yusivar, and b. kusumoputro. “estimation and control of sensorless brushless dc motor drive usin g ensemble kalman filter.” in proceedin gs of the 8th international conference on computer modeling and simulation (iccms 17) . acm, new york, usa, pp. 192-195, 2017. [17] d. e. rumelhart and j. l. mcclelland, “ex plorations in the microstructure of cognition. parallel distributed processing chap. 8,” mit press cambridge, usa., 1986. https://doi.org/10.1109/fit.2018.00011 https://doi.org/10.1109/fit.2018.00011 https://doi.org/10.1109/fit.2018.00011 https://doi.org/10.1109/fit.2018.00011 https://doi.org/10.3390/en10050616 https://doi.org/10.3390/en10050616 https://doi.org/10.3390/en10050616 https://doi.org/10.3390/en10050616 https://doi.org/10.3390/en10050616 https://doi.org/10.3390/en7010099 https://doi.org/10.3390/en7010099 https://doi.org/10.3390/en7010099 https://doi.org/10.3390/en7010099 http://dx.doi.org/10.1016/j.conengprac.2013.11.014 http://dx.doi.org/10.1016/j.conengprac.2013.11.014 http://dx.doi.org/10.1016/j.conengprac.2013.11.014 http://dx.doi.org/10.1016/j.conengprac.2013.11.014 https://doi.org/10.1109/melcon.2012.6196557 https://doi.org/10.1109/melcon.2012.6196557 https://doi.org/10.1109/melcon.2012.6196557 https://doi.org/10.1109/melcon.2012.6196557 https://doi.org/10.1109/edpe.2017.8123232 https://doi.org/10.1109/edpe.2017.8123232 https://doi.org/10.1109/edpe.2017.8123232 https://doi.org/10.1109/edpe.2017.8123232 https://doi.org/10.1109/tii.2012.2221721 https://doi.org/10.1109/tii.2012.2221721 https://doi.org/10.1109/tii.2012.2221721 https://doi.org/10.1109/tii.2012.2221721 https://doi.org/10.1109/tpel.2014.2328655 https://doi.org/10.1109/tpel.2014.2328655 https://doi.org/10.1109/tpel.2014.2328655 https://doi.org/10.1109/tpel.2014.2328655 https://doi.org/10.1109/tpel.2013.2261554 https://doi.org/10.1109/tpel.2013.2261554 https://doi.org/10.1109/tpel.2013.2261554 https://doi.org/10.1109/tpel.2003.823174 https://doi.org/10.1109/tpel.2003.823174 https://doi.org/10.1109/tpel.2003.823174 https://doi.org/10.1109/tpel.2010.2048126 https://doi.org/10.1109/tpel.2010.2048126 https://doi.org/10.1109/tpel.2010.2048126 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/pesgm.2018.8586472 https://doi.org/10.1109/icit.2017.7913105 https://doi.org/10.1109/icit.2017.7913105 https://doi.org/10.1109/icit.2017.7913105 https://doi.org/10.1109/icit.2017.7913105 https://doi.org/10.1109/iecon.2005.1569164 https://doi.org/10.1109/iecon.2005.1569164 https://doi.org/10.1109/iecon.2005.1569164 https://doi.org/10.1109/iecon.2005.1569164 http://journal.utem.edu.my/index.php/jtec/article/view/3648 http://journal.utem.edu.my/index.php/jtec/article/view/3648 http://journal.utem.edu.my/index.php/jtec/article/view/3648 http://journal.utem.edu.my/index.php/jtec/article/view/3648 http://journal.utem.edu.my/index.php/jtec/article/view/3648 https://doi.org/10.1145/3036331.3036353 https://doi.org/10.1145/3036331.3036353 https://doi.org/10.1145/3036331.3036353 https://doi.org/10.1145/3036331.3036353 https://doi.org/10.1145/3036331.3036353 mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. an energy and exergy analysis of photovoltaic system in bantul regency, indonesia arif rahman hakim *, wahyu tri handoyo, putri wullandari loka riset mekanisasi pengolahan hasil perikanan, badan riset dan sumber daya manusia, kementerian kelautan dan perikanan jl. imogiri barat km 11.5, jetis, bantul, d.i yogyakarta 55781, indonesia received 20 february 2018; received in revised form 24 april 2018; accepted 25 april 2018 published online 31 july 2018 abstract energy and exergy analysis has been conducted on photovoltaic (pv) system in bantul regency, a special region of yogyakarta, indonesia. the pv exergy analysis was used to determine the performance of the pv system by considering environmental factors other than solar irradiance. this research aims to obtain values of exergy and energy efficiencies in the pv system. the experiment results show that the energy efficiency value produced by the pv system was 8.62 to 74.18%, meanwhile its exergy efficiency was 0.29% to 9.40%, respectively. the value of exergy efficiency is lower than the value of energy efficiency. this result confirmed that the environmental factor greatly affects the output of the pv system. it can be concluded that high solar radiation does not always increase the production of exergy, since it is also influenced by the environmental temperature and the pv cells' temperature. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: exergy efficiency; energy; photovoltaic; solar radiation; bantul regency. i. introduction population growth, technology advances and lifestyle increase the community needs, and one of the vital needs is energy demand. currently, the largest source of energy comes from fossil-based (oil, gas, coal etc). however, fossil-based energy is nonrenewable energy so the number will continue to decrease [1][2]. in indonesia, the ministry of energy and mineral resources states that the reduced potential of fossil-based energy, especially for oil and natural gas, prompted the government to make renewable energy sources (res) a top priority for maintaining energy security and sustainability, given the huge potential of res to be a mainstay in the future of national energy supply. the average growth in energy demand during the 2015-2050 period is about 4.9% per year [3]. the research about res continues to develop along with the depletion of fossil-based energy reserves and people's concern for environmental sustainability [4][5][6]. currently, solar energy is one of the most widely developed renewable energy sources. tropical countries have the advantage of obtaining considerable sunshine throughout the year. sunlight that hits the surface of the earth can be converted into electrical energy through two ways: first, it is converted by using solar photovoltaic, and second through heating media using a solar collector that is often called solar thermal. the ability of the photovoltaic system to convert solar radiation into electrical energy is calculated based on its efficiency value (energy efficiency). the energy efficiency of pv is a ratio between the energy generated by the pv system and the total solar radiation that hits the surface of pv. therefore, only the electrical energy generated by pv is reviewed, while other parameters such as ambient temperature, pv cell temperature, wind velocity and heat capacity are not taken into account. this is due to the calculation of energy is based on a calculation of energy based on the law of thermodynamics i, where energy in and out of the system is not influenced by the environment [7]. some researchers have developed an analysis of the accuracy of pv performance values through the concept of exergy. this concept is based on the law of * corresponding author. tel: +62 813 3478 1593 e-mail address: arifrahmanh11@gmail.com https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.1-7&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 2 thermodynamics ii, so it can provide information about the energy lost from the system associated with thermodynamic processes that occur in the system. the exergy efficiency can be used to describe the quality difference between electricity and heat. the exergy of a thermodynamic system is the maximum work that can be done by the system when it undergoes reversible processes that bring the system into complete thermodynamic equilibrium with a defined reference environment [8]. several studies that have been conducted related to pv performance analysis, include sahin et al. (2007) that has investigated the pv performance characteristics based on exergy perspective [7], and sarhaddi et al. (2010) that has conducted electrical performance research, exergy components, and exergy efficiency in solar panels [9]. saidur et al. (2012) has reviewed the literatures on exergy analysis of solar energy applications [10], and pandev et al. (2013) has reviewed exergy analysis and parametric study of multi-crystalline solar photovoltaic systems [2]. therefore, we need to study pv performance that is influenced by the climate of a particular region. this research is aimed to analyze the relation of environmental parameters in bantul regency to energy and exergy in pv system. ii. method/material a. experimental set-up and procedure the solar photovoltaic (spv) system that is used in this research consists of a solar panels 100 wp with polycrystalline type and 2.4 m2 of total area pv; solar charge controller (scc) with mppt (maximum power point tracking) type, and battery 100 ah type gel deep cycle dod (depth of discharge) 30%. figure 1 is shown the experimental view of the spv system. the experiment is conducted during november 2017 and located in bantul region, yogyakarta with coordinates latitude -7.874818 and longitude 110.325537. the observation time starts from 08:00 up to 16:00 (western indonesian time). the observation data is solar radiation, wind velocity, ambient temperature, open-circuit voltage, short circuit current, voltage, and output current. the instrument that is used in this research consists of solar power meters (lutron spm-1116sd) to measure the intensity of solar energy with watt/m² units, anemometer (lutron yk-2005am) that measures wind velocity with m/s units, thermometer (lutron tm-946) to measure ambient temperature, and clamp meter (sanwa dcm2000dr) with max input dc / ac 1000v / 2000 a to measure the current, voltage, and frequency of electricity parameters. b. thermodynamics analysis the obtained data from the experiment mentioned above are then analyzed using an equation which developed by pandev et al. (2013) [2]. data analysed is conducted to find out the efficiency of energy, power conversion energy and exergy. the input energy from solar radiation (qin) is given in equation (1). 𝑄𝑖𝑛 = 𝐼𝑠 𝐴 (1) where is (w/m 2) is the intensity of solar radiation, and a (m2) is an area of spv module. the actual output of the spv module (qo) can be defined using equation (2). 𝑄0 = 𝑉𝑜𝑐 𝐼𝑠𝑐 𝐹𝐹 (2) where voc (v) is an open-circuit voltage, isc (a) is a short circuit current, and ff is a fill factor. the ff of the spv system can be defined as the ratio of the product of maximum power voltage (vm) and the maximum power current (im) to the product of open-circuit voltage and short circuit current, and can be expressed from equation (3). 𝐹𝐹 = 𝑉𝑚 𝐼𝑚 𝑉𝑜𝑐 𝐼𝑠𝑐 (3) figure 1. experimental view a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 3 using the definition from equation (3), equation (2) can also be expressed in equation (4). 𝑄0 = 𝑉𝑚 𝐼𝑚 (4) the input exergy (exin), i.e. exergy of solar radiation (exsolar) is given by equation (5). 𝐸𝑥𝑠𝑜𝑙𝑎𝑟 = 𝐸𝑥𝑖𝑛 = (1 − 𝑇𝑎 𝑇𝑠 )𝐼𝑠 𝐴 (5) where ts is the temperature of the sun which is taken as 5,777 k, and ta is ambient temperature (°c). exergy output pv system (exout) is given by equation (6). 𝐸𝑥𝑜𝑢𝑡 = 𝐸𝑥𝑒𝑙𝑒𝑐 + 𝐸𝑥𝑡ℎ𝑒𝑟𝑚 (6) where exelec is electrical exergy and extherm is thermal exergy. the calculation of electrical exergy of the pv system (𝐸𝑥𝑒𝑙𝑒𝑐 ) has been assumed that exergy content received by the photovoltaic surface is fully utilized to generate maximum electrical exergy (voc isc). 𝐸𝑥𝑒𝑙𝑒𝑐 = 𝐸𝑒𝑙𝑒𝑐 − 𝐼 ′ = 𝑉𝑜𝑐 𝐼𝑠𝑐 − (𝑉𝑜𝑐 𝐼𝑠𝑐 − 𝑉𝑚 𝐼𝑚 ) (7) where voc isc represents the electrical energy and (vocisc vm im) represents the electrical exergy destruction. therefore, equation (7) can define the electrical exergy that is shown in equation (8). 𝐸𝑥𝑒𝑙𝑒𝑐 = 𝑉𝑚 𝐼𝑚 (8) the thermal exergy of the system (𝐸𝑥𝑡ℎ𝑒𝑟𝑚 ) which is defined as the heat loss from the photovoltaic surface to the ambient can be represented by equation (9). 𝐸𝑥𝑡ℎ𝑒𝑟𝑚 = (1 − 𝑇𝑎 𝑇𝑐𝑒𝑙𝑙 ) 𝑄 (9) where 𝑄 = ℎ𝑐𝑎 𝐴 (𝑇𝑐𝑒𝑙𝑙 − 𝑇𝑎 ) and ℎ𝑐𝑎 = 5.7 + 3.8 𝑣; where tcell is cell temperature (°c), ℎ𝑐𝑎 is the heat transfer coefficient (w/m2 °c), and v is the wind velocity (m/s). using those equations, exergy of spv system can be written in equation (10). 𝐸𝑥𝑝𝑣 = 𝑉𝑚 𝐼𝑚 − (1 − 𝑇𝑎 𝑇𝑐𝑒𝑙𝑙 )ℎ𝑐𝑎 𝐴 (𝑇𝑐𝑒𝑙𝑙 − 𝑇𝑎 ) (10) the energy efficiency (η) can be defined by equation (11). 𝜂 = 𝑉𝑜𝑐 𝐼𝑠𝑐 𝐼𝑠 𝐴 (11) however, equation (11) definition is restricted to theoretical cases only. the power conversion efficiency (𝜂𝑝𝑐𝑒 ) of spv can be defined as the ratio of the actual electrical output (vm im) to the input energy (is a) on the spv surface and can be given in equation (12). 𝜂𝑝𝑐𝑒 = 𝑉𝑚 𝐼𝑚 𝐼𝑠 𝐴 (12) the energy efficiency and the power conversion efficiency can be defined using equation (11) and (12) that is shown in equation (13). 𝜂𝑝𝑐𝑒 = 𝜂 𝑉𝑚 𝐼𝑚 𝑉𝑜𝑐 𝐼𝑠𝑐 (13) the power conversion efficiency can also be defined in terms of ff using equation (14). 𝜂𝑝𝑐𝑒 = 𝐹𝐹𝜂 (14) for variations in ambient temperature and irradiance, the cell temperature can be estimated quite accurately with the linear approximation [11] using equation (15). 𝑇𝑐𝑒𝑙𝑙 = 𝑇𝑎 + [ 𝑇𝑁𝑂𝐶𝑇−20 800 𝑊/𝑚2 ] 𝐼𝑠 (15) where nominal operating cell temperature (tnoct) is defined as the cell temperature measured under open circuit when the ambient temperature is 20 °c, irradiance is 800 w/m2, and wind velocity is 1 m/s. its value is usually around 45 °c. in general, the exergy efficiency (𝜓) is defined as the ratio of output exergy to the input exergy and given by equation (16). 𝜓 = 𝑂𝑢𝑡𝑝𝑢𝑡 𝑒𝑥𝑒𝑟𝑔𝑦 𝐼𝑛𝑝𝑢𝑡 𝑒𝑥𝑒𝑟𝑔𝑦 (16) using the equation (16), the exergy efficiency (𝜓 ) can be expressed in equation (17). 𝜓 = 𝑉𝑚 𝐼𝑚−(1− 𝑇𝑎 𝑇𝑐𝑒𝑙𝑙 )ℎ𝑐𝑎 𝐴 (𝑇𝑐𝑒𝑙𝑙−𝑇𝑎) (1− 𝑇𝑎 𝑇𝑠 )𝐼𝑠 𝐴 (17) iii. result and discussion the specification of polycrystalline photovoltaic based on data from manufacture is shown in table 1. these data are taken from standard test condition, i.e. at solar radiation of 1000 w/m2, air mass of 1.5 kg/m3 and ambient temperature of 25 °c. the results of field observation data including the intensity of sunlight, wind velocity, ambient temperature (ta), solar cell temperature (tcell), current (isc) and voltage (voc) of pv, output (p) and energy efficiency (η), power conversion efficiency (ηpce) and exergy efficiency (ψ) are presented in table 2. the average intensity of solar radiation during november 2017 from 08:00 up to 16:00 is 76.47 to 604.43 watt/m2. in the morning, the intensity of solar radiation is low, then it increases during the day and backs down in the afternoon. the intensity of solar radiation in november tends to be low as it is the rainy season. furthermore, the value of wind velocity has the same pattern, nearly equal to the intensity of solar radiation; where the value of wind velocity is low in the morning and in the afternoon but high during the table 1. specification of polycrystalline pv paramaters value output power (pmax) 100 wp max power voltage (vpm) 18.0 volt max power current (ipm) 5.60 ampere open circuit voltage (voc) 22.6 volt short circuit current (isc) 6.02 ampere module efficiency 15% operating module temperature -40 °c to +85 °c maximum system voltage 1000 v dc maximum series fuse rating 20 a power tolerance ± 3% a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 4 day. the value of wind velocity during the day is ranged from 0.01 to 0.51 m/s. the average of environmental temperature reaches the lowest value at 16:00 with the value of 27.93 °c, and reaches the highest value at 11:30 with the value of 33.35 °c. the increasing of solar radiation intensity will cause the environmental temperature to rise. the relation between the intensity of solar radiation with environmental temperature is presented in figure 2. furthermore, an increase in ambient temperature (ta) will trigger an increase in cell temperature (tcell). in addition, cell temperature (tcell) is also affected by the nominal operating temperature (tnoct). if the fill factor (ff) value of a solar cell is higher, the solar cell output (p) and power conversion efficiency (ηpce) will be better. the value of ff depends greatly on the value of multiplication of voc and isc (see equation (3)). however, the price of voc and isc is closely related to table 2. result of field observation and analyze time solar radiation (watt/m2) wind velocity (m/sec) ta (oc) tcell (oc) isc (a) voc (v) vm (v) im (a) ff p (w) η (%) ηpce (%) ψ (%) 08:00 247.08 0.01 30.23 36.41 6.77 19.42 14.50 3.85 0.42 55.83 22.17 9.41 7.02 08:30 373.47 0.09 31.32 40.65 6.78 19.05 16.00 4.58 0.57 73.33 14.42 8.18 4.74 09:00 415.95 0.09 31.92 42.32 6.79 18.85 16.33 4.63 0.59 79.49 12.82 7.58 3.89 09:30 421.07 0.14 32.15 42.68 6.79 18.77 15.83 5.12 0.64 81.01 12.62 8.02 4.20 10:00 434.43 0.26 32.32 43.18 6.80 18.71 16.00 5.07 0.64 81.07 12.20 7.78 3.58 10:30 327.82 0.22 32.53 40.73 6.80 18.64 15.33 4.43 0.54 67.98 16.10 8.64 5.38 11:00 307.10 0.40 31.55 39.23 6.79 18.97 14.83 5.53 0.64 82.08 17.47 11.14 7.65 11:30 604.43 0.35 33.35 48.46 6.81 18.36 16.50 5.07 0.67 83.60 8.62 5.76 0.29 12:00 333.22 0.35 32.23 40.56 6.79 18.74 15.33 4.45 0.54 68.23 15.92 8.53 4.96 12:30 272.55 0.42 30.27 37.08 6.77 19.41 15.83 4.63 0.56 73.36 20.08 11.22 7.91 13:00 241.63 0.49 30.95 36.99 6.78 19.18 16.33 3.92 0.49 63.97 22.41 11.03 7.99 13:30 362.63 0.51 30.90 39.97 6.78 19.19 16.33 3.60 0.45 58.80 14.95 6.76 2.43 14:00 307.47 0.36 30.87 38.55 6.78 19.21 16.33 2.88 0.36 47.09 17.64 6.38 2.87 14:30 178.95 0.14 29.88 34.36 6.76 19.54 15.17 3.15 0.36 47.78 30.77 11.12 9.15 15:00 106.20 0.36 28.78 31.44 6.75 19.91 14.83 1.85 0.20 27.44 52.73 10.77 9.32 15:30 86.28 0.23 28.05 30.21 6.74 20.16 14.17 1.53 0.16 21.72 65.62 10.49 9.36 16:00 76.47 0.26 27.93 29.85 6.74 20.20 14.17 1.35 0.14 19.13 74.18 10.42 9.40 figure 2. the relationship intensity of solar radiation with ambient temperature 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 25.00 26.00 27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 s o la r r a d ia ti o n ( w a tt /m 2 ) t e m p e ra tu re ( o c ) time ambient temp solar radiation a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 5 the material of the semi conductor. the voc and isc value are reversed for a given type of semiconductor material. the semiconductor material that has a large eg (energy gap) will have a large voc value and a small isc value, vice versa. the value of ff in this study is 0.14 to 0.67. the highest ff value is reached at a maximum solar intensity (figure 3). exergy is the maximum amount of net work obtained when the material flow is brought from the initial state to the dead state through a process involving interaction with the environment only. a system is considered to be in a dead state when it is in thermal, mechanical, and chemical equilibrium with the environment. in the analysis, it is important to understand the difference between energy and exergy. it is also important to consider the quality and quantity of energy used to achieve a particular goal and in reality to achieve the efficient and effective use of energy resources. one of the main uses of the exergy concept is the balance of exergy in the thermal systems analysis. exergy balance (exergy analysis) can be viewed as a declaration of energy degradation law. exergy analysis is a method for identification of the type, location and amount of thermal loss. the identification and qualification of these losses allow us to evaluate and improve thermal system design [12]. electrical exergy (exelec) produced by pv in this study is ranged from 19.13 to 83.60 w. the largest electrical exergy (exelec) is at 11:30 and the lowest is at 16:00. electrical exergy (exelec) values have the same pattern of solar radiation (is) received in pv. if the solar radiation (is) received by the pv surface is higher, it will result in greater electrical exergy (exelec). based on equation (8), the high value of solar radiation (is) will produce a large current (im) and voltage (vm). however, when compared to the produced pv exergy (expv), the value of electrical exergy (exelect) does not reflect the same pattern (figure 4). in the highest electrical exergy (exelec) conditions, the value of exergy pv (expv) is precisely the lowest. exergy pv (expv) value is between 4.22 to 56.07 w. the lowest exergy value occurs at 11:30 when the solar radiation (is) obtain the highest value. increasing ambient temperatures (ta) results in increasing thermal exergy (extherm) and decreasing exergy pv (expv) in the system (figure 5). energy efficiency (η) is obtained from voc and isc values as electrical output compared to solar radiation per unit area on the pv surface as the energy input. energy efficiency (η) is only theoretical value since it has not calculated the value of fill factor (ff). the energy efficiency (η) being produced by pv during the experiment is 8.62% to 74.18%. the lowest value at the middle day (11.30) is 8.62%, while the highest value at 16:00 is 74.18% (figure 5). the actual picture of the energy conversion production is obtained from the value of power conversion energy (pce). pce values vary between 5.76% to 11.22% (figure 6), lower than the value of energy efficiency (η). factor that affects the value of energy conversion is fill factor (ff), which is the value of the maximum power output ratio of pv with the theoretical power (isc, voc) pv output. when the value of energy efficiency is high and the ff is small, then the energy conversion value will be small. the maximum output of pv is the result of the current value (im) and voltage (vm) of pv that is influenced by the intensity of solar radiation (watt/m2). exergy efficiency value of pv (equation (17)) can be obtained from electrical exergy output minus thermal exergy then compared with exergy input. figure 3. effect of solar radiation on fill factor 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 f il l f a ct o r s o la r r a d ia ti o n ( w /m 2 ) time solar radiation fill factor a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 6 exergy value is ranged from 0.29% to 0.40%, with the lowest value at 11:30, 603.43 watt/m2 solar radiation intensity, and 33.35 °c environmental temperature. the increasing of environmental temperature also increase the solar cell temperature to become 48.46 °c, while the highest efficiency value is 9.40% at 16:00. during that time, the intensity of solar radiation reaches the lowest value as well as the environmental temperature. iv. conclusion the value of energy efficiency (η) produced by pv is 8.62% to 74.18% while its exergy efficiency (ψ) is 0.29% to 9.40%, respectively. the value of the exergy efficiency (ψ) is much lower than the energy efficiency (η) being produced. environmental factors greatly affect the output of pv. large solar radiation does not directly increase the exergy output. the exergy output is strongly influenced by the figure 4. the relationship between solar radiation, electrical exergy, and exergy photovoltaic figure 5. the relationship between ambient temperature and exergy thermal 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 s o la r r a d ia ti o n ( w /m 2 ) e x e rg y ( w a tt ) time exergy electrical exergy pv solar radiation 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 t e m p e ra tu re ( o c ) e x e rg y ( w a tt ) time exergy thermal exergy pv ambient temp tcell a.r. hakim et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 1–7 7 environmental temperature and temperature of pv cells. the high environmental temperature in bantul regency and low solar intensity at the time of the research have affected the performance of the photovoltaic system. acknowledgement the authors would like to thank the head of loka riset mekanisasi pengolahan hasil perikanan (lrmphp) who has supported and facilitated this research activity, as well as to the research colleagues and technicians who have helped the success of this activity. references [1] i. a. ibrahim, t. khatib, and a. mohamed, “optimal sizing of a standalone photovoltaic system for remote housing electrification using numerical algorithm and improved system models,” energy, vol. 126, pp. 392–403, 2017. [2] a. k. pandey, v. v. tyagi, and s. k. tyagi, “exergetic analysis and parametric study of multi-crystalline solar photovoltaic system at a typical climatic zone,” clean technol. environ. policy, vol. 15, no. 2, pp. 333–343, 2013. [3] outlook energi indonesia 2016. jakarta: sekretariat jenderal dewan energi nasional, 2016. [4] t. kulworawanichpong and j. j. mwambeleko, “design and costing of a stand-alone solar photovoltaic system for a tanzanian rural household,” sustain. energy technol. assessments, vol. 12, pp. 53–59, 2015. [5] m. kumar and a. kumar, “performance assessment and degradation analysis of solar photovoltaic technologies: a review,” renew. sustain. energy rev., vol. 78, no. november 2016, pp. 554–587, 2017. [6] w. x. shen, “optimally sizing of solar array and battery in a standalone photovoltaic system in malaysia,” renew. energy, vol. 34, no. 1, pp. 348–352, 2009. [7] a. duran sahin, i. dincer, and m. a. rosen, “thermodynamic analysis of solar photovoltaic cell systems,” sol. energy mater. sol. cells, vol. 91, no. 2–3, pp. 153–159, 2007. [8] d. hamdani, k. subagiada, and l. subagiyo, “analisis kinerja solar photovoltaic system (sps) berdasarkan tinjauan efisiensi energi dan eksergi,” j. mater. dan energi indones., vol. 1, no. 2, pp. 84–92, 2011. [9] f. sarhaddi, s. farahat, h. ajam, and a. behzadmehr, “exergetic performance evaluation of a solar photovoltaic (pv) array,” aust. j. basic appl. sci., vol. 4, no. 3, pp. 502– 519, 2010. [10] r. saidur, g. boroumandjazi, s. mekhlif, and m. jameel, “exergy analysis of solar energy applications,” renew. sustain. energy rev., vol. 16, no. 1, pp. 350–356, 2012. [11] a. luque and s. hegedus, handbook of photovoltaic science and engineering. chichester: wiley, 2003. [12] d. priambodo, e. dewita, and i. d. irianto, “analisis energi dan eksergi pada sistem htr-10 siklus turbin uap,” j. pengemb. energi nukl., vol. 17, no. 1, pp. 33–43, 2015. figure 6. variation of different efficiencies and solar radiation 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 s o la r r a d ia ti o n ( w a tt /m 2 ) e ff ic ie n ci e s (% ) η ηpce ψ solar radiation http://dx.doi.org/10.1016/j.energy.2017.03.053 http://dx.doi.org/10.1016/j.energy.2017.03.053 http://dx.doi.org/10.1016/j.energy.2017.03.053 http://dx.doi.org/10.1016/j.energy.2017.03.053 http://dx.doi.org/10.1007/s10098-012-0528-8 http://dx.doi.org/10.1007/s10098-012-0528-8 http://dx.doi.org/10.1007/s10098-012-0528-8 http://dx.doi.org/10.1007/s10098-012-0528-8 https://den.go.id/index.php/publikasi/download/49 https://den.go.id/index.php/publikasi/download/49 http://dx.doi.org/10.1016/j.seta.2015.10.001 http://dx.doi.org/10.1016/j.seta.2015.10.001 http://dx.doi.org/10.1016/j.seta.2015.10.001 http://dx.doi.org/10.1016/j.seta.2015.10.001 http://dx.doi.org/10.1016/j.rser.2017.04.083 http://dx.doi.org/10.1016/j.rser.2017.04.083 http://dx.doi.org/10.1016/j.rser.2017.04.083 http://dx.doi.org/10.1016/j.rser.2017.04.083 http://dx.doi.org/10.1016/j.renene.2008.03.015 http://dx.doi.org/10.1016/j.renene.2008.03.015 http://dx.doi.org/10.1016/j.renene.2008.03.015 http://dx.doi.org/10.1016/j.solmat.2006.07.015 http://dx.doi.org/10.1016/j.solmat.2006.07.015 http://dx.doi.org/10.1016/j.solmat.2006.07.015 https://www.academia.edu/3754289/analisis_kinerja_solar_photovoltaic_system_sps_berdasarkananalisis_kinerja_solar_photovoltaic_system https://www.academia.edu/3754289/analisis_kinerja_solar_photovoltaic_system_sps_berdasarkananalisis_kinerja_solar_photovoltaic_system https://www.academia.edu/3754289/analisis_kinerja_solar_photovoltaic_system_sps_berdasarkananalisis_kinerja_solar_photovoltaic_system https://www.academia.edu/3754289/analisis_kinerja_solar_photovoltaic_system_sps_berdasarkananalisis_kinerja_solar_photovoltaic_system https://profdoc.um.ac.ir/paper-abstract-1027007.html https://profdoc.um.ac.ir/paper-abstract-1027007.html https://profdoc.um.ac.ir/paper-abstract-1027007.html https://profdoc.um.ac.ir/paper-abstract-1027007.html http://dx.doi.org/10.1016/j.rser.2011.07.162 http://dx.doi.org/10.1016/j.rser.2011.07.162 http://dx.doi.org/10.1016/j.rser.2011.07.162 https://www.wiley.com/en-id/handbook+of+photovoltaic+science+and+engineering,+2nd+edition-p-9780470721698 https://www.wiley.com/en-id/handbook+of+photovoltaic+science+and+engineering,+2nd+edition-p-9780470721698 http://dx.doi.org/10.17146/jpen.2015.17.1.2561 http://dx.doi.org/10.17146/jpen.2015.17.1.2561 http://dx.doi.org/10.17146/jpen.2015.17.1.2561 mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-22-2503055 (ext. 215) tel: +62-22-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.php/ mev/login need a username/password? go to registration at: http://mevjournal.com/index.php/ mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nc-licensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 editor-in-chief prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa barcelona, spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. bambang riyanto school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia prof. dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia prof. george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of prof. dr. ir. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 associate editors dian andriani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia aam muharam, m.t. asem, interdisciplinary graduate school of engineering kyushu university fukuoka, japan yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, korea, republic of roni permana saputra, m.eng. dyson school of design engineering, robot intelligence laboratory, imperial college, london, united kingdom tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 © 2018 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, five papers are published with the total number of paper pages of 40 pages. the authors come from indonesia, slovakia, bulgaria, and united kingdom. one paper is related to mechatronics which addresses design, manufacture, and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav). one paper presents a preliminary investigation of sleep-related driving fatigue experiment in indonesia. three papers fall in the electrical power topic. the first paper reports energy and exergy analysis of a photovoltaic (pv) system based on experiment results under typical climate in yogyakarta. the result confirmes that temperature greatly affects the output of the pv system, besides the solar irradiance. the second paper proposes a method for condition assessment of power transformers based on moisture level using fuzzy logic. the method was implemented to assess conditions of 65 power transformers which are installed in the transmission system of kosovo. the third paper presents a new principle of inductive vibration power harvester. the harvester is a pendulum that uses energy capacitor which is the mass. the experimental results indicate that the optimal results of the harvester with an accumulator shows especially for resonant zone 3.75 hz, 7 hz, and 10 hz. since the first volume, our journal provides discretion in the financial term by waiving the article processing charge. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2018 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 ii list of contents an energy and exergy analysis of photovoltaic system in bantul regency, indonesia arif rahman hakim, wahyu tri handoyo, putri wullandari ....................................................... 1-7 preliminary investigation of sleep-related driving fatigue experiment in indonesia kadek heri sanjaya, yukhi mustaqim kusuma sya'bana, shaun hutchinson, cyriel diels ..... 8-16 condition assessment of power transformers status based on moisture level using fuzzy logic techniques vezir rexhepi, petar nakov ......................................................................................................... 17-24 pendulum energy harvester with amplifier michal černý, michal dzurilla, miloš musil, marek gašparík .................................................. 25-31 design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav) gesang nugroho, dicky dectaviansyah ...................................................................................... 32-40 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 09, issue 1, july 2018 abstracts sheet e-issn: 2088-6985 date of issues: 31 july 2018 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. arif rahman hakim*, wahyu tri handoyo, putri wullandari (loka riset mekanisasi pengolahan hasil perikanan, badan riset dan sumber daya manusia, kementerian kelautan dan perikanan jl. imogiri barat km 11.5, jetis, bantul, d.i yogyakarta 55781, indonesia) an energy and exergy analysis of photovoltaic system in bantul regency, indonesia journal of mechatronics, electrical power, and vehicular technology, july 2018, vol. 9, no. 1, p. 1-7, 6 ill, 2 tab, 12 ref. energy and exergy analysis has been conducted on photovoltaic (pv) system in bantul regency, a special region of yogyakarta, indonesia. the pv exergy analysis was used to determine the performance of the pv system by considering environmental factors other than solar irradiance. this research aims to obtain values of exergy and energy efficiencies in the pv system. the experiment results show that the energy efficiency value produced by the pv system was 8.62–74.18%, meanwhile its exergy efficiency was 0.29%-9.40%, respectively. the value of exergy efficiency is lower than the value of energy efficiency. this result confirmed that the environmental factor greatly affects the output of the pv system. it can be concluded that high solar radiation does not always increase the production of exergy, since it is also influenced by the environmental temperature and the pv cells' temperature. (author) keywords: exergy efficiency; energy; photovoltaic; solar radiation; bantul regency. kadek heri sanjayaa*, yukhi mustaqim kusuma sya'banaa, shaun hutchinsonb, cyriel dielsb (aresearch centre for electrical power and mechatronics, indonesian institute of sciences jalan cisitu no. 21/154d, bandung, 40135, indonesia; bcentre for mobility and transport, coventry university priory street, coventry, cv15fb, united kingdom) preliminary investigation of sleep-related driving fatigue experiment in indonesia journal of mechatronics, electrical power, and vehicular technology, july 2018, vol. 9, no. 1, p. 8-16, 10 ill, 0 tab, 42 ref. sleep-related driving fatigue has been recognized as one of the main causes of traffic accidents. in indonesia, experiment-based driving fatigue study is still very limited, therefore it is necessary to develop a laboratory-based experimental procedure for sleep-related fatigue study. in this preliminary study, we performed a literature review to find references for the procedure and three pilot experiments to test the instruments and procedure to be used in measuring driving fatigue. three subjects participated, both from experienced and inexperienced drivers. our pilot experiments were performed on a driving simulator using opends software with brake and lane change test reaction time measurement. we measured sleepiness by using karolinska sleepiness scale (kss) questionnaire. the conditions of the experiment were based on illumination intensity as well as preand post-lunch session. we found that lane change reaction time is more potential than brake reaction time to measure driving performance as shown by more fluctuating data. post-lunch seems to induce drowsiness greater than illumination intensity. kss questionnaire seems non-linear with driving performance data. we need to test further these speculations in the future studies involving a sufficient number of subjects. we also need to compare the effect of circadian rhythm and sleep deprivation on driving fatigue. the use of eye closure and physiological measurement in further study will enable us to measure driving fatigue more objectively. considering the limitations, more preliminary experiments are required to be performed before conducting the main experiment of driving fatigue. (author) keywords: driving fatigue; sleepiness; experiment procedure; driving simulation. vezir rexhepi*, petar nakov (technical university of sofia, faculty of electrical engineering, boulevard “sveti kliment ohridski”, 8, 1000, sofia bulgaria) condition assessment of power transformers status based on moisture level using fuzzy logic techniques journal of mechatronics, electrical power, and vehicular technology, july 2018, vol. 9, no. 1, p. 17-24, 8 ill, 4 tab, 25 ref. power transformers are one of the most expensive components; therefore the focus on their status and its continuous operation is the primary task. in the power systems, condition assessment of performance and reliability is based on the state of components, measurements, testing, and maintenance as well as their diagnosis. hence, condition assessment of power transformer parameters is important regarding their status and finding incipient failures. among many factors, the most factors that affect the safe operation and life expectancy of the transformer is the moisture in oil. it is known that the low moisture oil in power transformers causes many problems including electrical breakdown, increase the amount of partial discharge, decreases the dielectric withstand strength and other phenomena. thus, knowledge about the moisture concentration in a power transformer is significantly important for safe operation and lifespan. in this study, moisture level in oil is estimated, and its status classification is proposed by using fuzzy logic techniques for the power transformer monitoring and condition assessment. moreover, the goal of the study is to find methods and techniques for the condition assessment of power transformers status based on the state of moisture in oil using the fuzzy logic technique. these applied techniques increase the power system reliability, help to reduce incipient failures and give the better maintenance plan using an algorithm based on logic rules. also, by using the fuzzy logic techniques, it is easier to prevent journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv failures which may have consequences not only for transformers but also for the power system as a whole. (author) keywords: moisture in oil; power transformers; fuzzy logic techniques; failures; condition assessment; measurements. michal černý*, michal dzurilla, miloš musil, marek gašparík (faculty of mechanical engineering, slovak university of technology námestie slobody 17, 812 31 bratislava, slovakia) pendulum energy harvester with amplifier journal of mechatronics, electrical power, and vehicular technology, july 2018, vol. 9, no. 1, p. 25-31, 9 ill, 2 tab, 13 ref. this paper presents a new principle of inductive vibration power harvester. harvester is a pendulum that uses energy capacitor which is the mass. the mass is connected to the pendulum via a gearbox to achieve greater movement of the pendulum that generates an electromagnetic voltage. the harvester is developed at a very low frequency (1 to 10 hz) which uses the rectified magnetic fluxes. magnets are statically placed in the harvester case, and relative motion is carried out by the coil. magnets are static, and the coil moves due to the weight ratio of magnets which the steel leads of the magnetic flux and the coil itself. this paper is focused on a harvester with a mechanical amplifier with the proposed technique is brings the plow harvester access with an auxiliary force. the experimental results indicate that the optimal results of the harvester with an accumulator for the resonant zone are 3.75 hz, 7 hz, and 10 hz. (author) keywords: pendulum; energy; harvester; amplifier; vibration. gesang nugroho*, dicky dectaviansyah (department of mechanical and industrial engineering, faculty of engineering, universitas gadjah mada yogyakarta 55281, indonesia) design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav) journal of mechatronics, electrical power, and vehicular technology, july 2018, vol. 9, no. 1, p. 32-40, 11 ill, 1 tab, 12 ref. in conducting a disaster monitoring mission, an unmanned aerial vehicle (uav) has to travel a long distance to cover the region that is hited by a disaster. in the monitoring mission, air data and attitude heading reference system (adahrs) data are very important to always be displayed on the ground control station (gcs). unfortunately, the area of monitoring mission is very wide, whereas the usage of an omnidirectional antenna in the disaster monitoring mission is limited to the uav maximum range. therefore, a high gain directional antenna is needed. however, the directional antenna has a disadvantage of always being directed to the target. to solve this problem, antenna tracker is made to track the uav continuously so that the directional antenna can always be directed to the flying uav. an antenna tracker using a 32-bit microcontroller and gps with two degrees-of-freedom was developed. it is able to move 360 degrees on azimuth axis (yaw) and 90 degrees on elevation axis (pitch). meanwhile, the directional antenna is three elements yagi type with a radiation capability of 6 dbi. by using the antenna tracker, larger uav range was obtained and the connection between the uav and the gcs could always be maintained with a minimum fluctuation of rssi signal, compared to those without using antenna tracker. (author) keywords: uav-antenna tracker; disaster monitoring; ground control station; uav. journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2018.v9.32-40 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav) gesang nugroho *, dicky dectaviansyah department of mechanical and industrial engineering, faculty of engineering, universitas gadjah mada jl. grafika no. 2, yogyakarta 55281, indonesia received 4 december 2017; received in revised form 6 july 2018; accepted 10 july 2018 published online 31 july 2018 abstract in conducting a disaster monitoring mission, an unmanned aerial vehicle (uav) has to travel a long distance to cover the region that is hited by a disaster. in the monitoring mission, air data and attitude heading reference system (adahrs) data are very important to always be displayed on the ground control station (gcs). unfortunately, the area of monitoring mission is very wide, whereas the usage of an omnidirectional antenna in the disaster monitoring mission is limited to the uav maximum range. therefore, a high gain directional antenna is needed. however, the directional antenna has a disadvantage of always being directed to the target. to solve this problem, antenna tracker is made to track the uav continuously so that the directional antenna can always be directed to the flying uav. an antenna tracker using a 32-bit microcontroller and gps with two degreesof-freedom was developed. it is able to move 360 degrees on azimuth axis (yaw) and 90 degrees on elevation axis (pitch). meanwhile, the directional antenna is 3 element yagi type with a radiation capability of 6 dbi. by using the antenna tracker, larger uav range was obtained and the connection between the uav and the gcs could always be maintained with a minimum fluctuation of rssi signal, compared to those without using antenna tracker. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: uav-antenna tracker; disaster monitoring; ground control station; uav. i. introduction unmanned aerial system (uas) has several system builders such as an unmanned aerial vehicle (uav) and ground control station (gcs). the gcs plays an important role in a mission that has been done by the uav. air data and attitude heading reference system (adahrs) data should always be displayed on the gcs to monitor autonomously the flying uav. a specified frequency telemetry module is required in order to monitor the uav continuously. the operator is able to determine the navigation mission by making a waypoint and monitor the uav flight data on the gcs during flight. to transmit the signal required by the antenna, two types of antenna are needed, that are omnidirectional and directional antennas which have different characteristic. the most difference of these antennas is a radiation pattern. the omnidirectional antenna has a radiation pattern to all direction, so it has a directivity of 1 db or 0 db [1]. meanwhile directional antenna has a radiation pattern that focuses on a certain degree, so that beamwidth degree of radiation emission would not be emitted to the large area but will be focused on a certain area on a specific angle and has a directivity value higher than 1 db [2]. antenna tracker is used for keeping directing high gain directional antenna to always facing the target, in this case an uav. considering directional antenna has a radiation pattern that is focused on certain angle and area, whereas the antenna that usually used on uav is the omnidirectional type, then to keep uav on the radiation area of the directional antenna, an antenna tracker is needed to track the uav continuously. mechanical design of the antenna tracker has several criteria such as having two degrees of freedom, azimuth angle (yaw) that able to move 360 degrees (continuous rotation) and elevation angle (pitch) that able to move 90 degrees (perpendicular from planar geometry) [3]. servo motor or dc motor is needed to * corresponding author. tel: +62 851 0655 5999 e-mail address: gesangnugroho@ugm.ac.id https://dx.doi.org/10.14203/j.mev.2018.v9.32-40 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.32-40 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.32-40&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 33 move the frame on azimuth and elevation axis. in order to obtain high torque and smooth rotation, suitable gear is used. when a satellite passes over an earth station and point directly at it, the angular velocity of the satellite antenna can increase rapidly due to the gimbal kinematics. angular velocity minimization method for the satellite antenna tracker was reported [4]. a sting nailing algorithm for fast and correct generation of the shortest path was proposed. the number of control system that implements standard algorithms pid, fuzzy, genetic, neural network, and so forth was developed to control an antenna. many researchers have developed manual, differential, monopulse, electronic, auto-tracking, left-right, conical, and stepped tracking methods to track the signal source. the performances of the implemented standard algorithms and tracking methods to track signal source were discussed [5]. an attitude heading and reference system (ahrs) for marine satellite tracking antennas (mstas) to overcome attitude disturbance due to ship vibration and rotation motion was presented [6]. the performance of the designed ahrs for msta is assessed through hardware experiments using a stewart platform and high precision commercial ahrs. a fault tolerant control (ftc) system is proposed for the satellite tracking antenna that directs the onboard antenna toward a chosen satellite while the high sea waves disturb the antenna [7]. the ftc system maintains the tracking functionality by employing proper control strategy. a robust fault diagnosis system is designed to supervise the ftc system. a rooftop dish-antenna tracking system was designed, and appropriate motors and corresponding drives were selected. a mathematical model of such a system was presented. the tracking system to control the antenna was realized practically with commercial plc and display units. a matlab-based trackingsystem simulator was also developed to test the control system performance [8]. an innovative dual polarization antenna working at ku band (14 ÷ 14.5 ghz) based on slotted wave guide array (swga) technology was presented [9]. the method allows to simultaneously generate two orthogonal circular polarizations that are combined to generate two orthogonal linear polarizations with polarizationtracking capabilities and very low cross-polarization level. the antenna is composed of two interleaved slotted ridge waveguide arrays connected to a polarizer, realized with an array of triangular-base ridged cavities. reliability and efficiency of an electromagnetic band gap (ebg) matrix antenna for beam forming and beam steering applications was described and demonstrated through experimental prototype. the proposed antenna is based on the equivalent radiating surface approach and used special ebg antennas called “pixels” to overcome some of the array approach defects. the antenna has demonstrated different electromagnetic behaviors, such as low mutual coupling, high gain preservation for high scanning angles values, etc. [10]. many previous researches discuss about antenna tracker, however research regarding design, manufacturing process and testing, and application to track an unmanned aerial vehicle is rarely found. this paper shares the design, manufacture, and examination of an antenna tracker with two degrees of freedom in order to track uav automatically. this allows the uav to fly and cover wider signal range without losing contact with the gcs. ii. research method research methodology can be shown in figure 1. the first step is creating a 3d model using autodesk inventor software. before the design process, the design requirements must be determined. 3d models are based on design results. the second step is machining the mechanical components using cnc laser cutting machine, lathe machine, and drill machine. the frame material used for antenna tracker is plywood with a thickness of 5 mm. the third step is machining the mechanical components. the gear was made of polyvinyl chloride (pvc) material with a flange made of brass. the shaft that needed to move the elevation angle was also made of brass. the fourth step is designing the control system by using a 32-bit microcontroller and gps module. several kinds of setup were done on the mission planner software, such as firmware downloading and imu sensor, barometer, gps, and electronic compass calibration which exist on 32-bit microcontroller. the next step is assembling the antenna tracker, and merging the mechanical part with the control system followed by functionality test for the actuator or servo motor that able to rotate 360 degrees (continuous rotation) and elevation of 90 degrees. the last step is figure 1. research methodology 3d modelling of antenna tracker antenna tracker manufacturing tracking control system design merging mechanical part with control system tracking performance test tracker shows good performance? start end antenna tracker meets the requirements? yes yes no no g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 34 implementing the antenna tracker to track an uav, by setting the control parameter using mission planner software, such as pid value and adahrs. the result of tracking ability of the antenna tracker was obtained from the sd card black box data logger controller. these data were processed to be a tendency graphic. therefore the performance of the antenna tracker can be seen by observing the result of data processing analysis. besides the tracking performance, the signal connection quality of telemetry modem between uav and antenna tracker when using an omnidirectional antenna, directional antenna with antenna tracker, and directional antenna without antenna tracker were also compared. iii. results and discussion a. control system of antenna tracker the antenna tracker was controlled by using a 32bit microcontroller as shown in figure 2. it has a specification as follows: • microprocessor: 1 chip 32-bit stm32f427 cortex m4, with specification 168 mhz/256 kb ram/2 mb flash, 1 chip 32-bit stm32f103 failsafe co-processor • sensor: st micro l3gd20 3-axis 16bitgyroscope, st micro lsm303 d3-axis 14bitaccelerometer/magnetometer, invensense mpu 6000 3-axis accelerometer/gyrometer • meas ms5611 barometer • voltage input of 3.3 to 10 volt dc. gps module is using ublox product with ublox lea-6h as the chipset that has an accuracy of approximately 3 meters. other than that, ublox lea6h gps already has an electronic compass with the type of hmc5883l. therefore, there are 2 electronic compasses, the first one is on the 32-bit microcontroller and the other one is on the gps module. when the antenna tracker works, the electronic compass that used as the primary compass is the electronic compass that located on the gps module. it is because the electronic compass has a high risk of electromagnetic noise exposure from the cable circuit that located around the 32-bit microcontroller, and there is no electromagnetic noise shielding applied on the microcontroller. gps module is located at a place away from the cable and telemetry module to avoid electromagnetic noise that causes inaccurate effect of the antenna tracker performance. b. antenna tracker actuator servo motor was used as an actuator to move the mechanical part of the antenna tracker that are azimuth axis (yaw) by 360 degrees movement and elevation axis (pitch) by 90 degrees movement along with gear transmission to obtain high torque. the servo motor specification is as follow: angular velocity 62 rpm on 6 vdc; rotation angle 360 degrees (continuous rotation); torque 15 kg.cm @6 vdc; servo dimension 42 × 20.5 × 39.5 mm; and servo motor weight 60 gram. c. mechanical design of antenna tracker mechanical design of the antenna tracker was adapted to the needs of the assignment that was given to the uav. in this case, the uav assignment was to monitor a disaster area which is always identical with the isolated area and difficult to be accessed. therefore, antenna tracker must be designed to have high portability so that it would be easy to be re-assembled and carried. the mechanical system of the antenna tracker was designed using autodesk inventor software as shown in figure 3. on the movement of two degrees of freedom, the azimuth and elevation axis, the antenna tracker was using two pieces of high torque servo motors on each axis. gear transmission was used to obtain the constant and smooth rotation and higher torque on each axis, as shown in figure 4(a) and 4(b). figure 2. 32-bit controller [6] g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 35 from figure 4, it can be seen how each axis of the antenna tracker moved by the servo motor. the movement was smoothened by the gear ratio on every axis and the torque was increased in every axis. to calculate the servo motor torque and rotation on each axis, equations (1) to (3) were used: gear ratio = nin nout (1) angular speed = gear ratio × ωin (2) 𝑇𝑜𝑟𝑞𝑢𝑒 𝑂𝑢𝑡 = 𝜏𝑖𝑛 𝐺𝑒𝑎𝑟 𝑅𝑎𝑡𝑖𝑜 (3) where nin is rotation speed input; nout is rotation speed output; ωin is angular speed input; 𝜏𝑖𝑛 is torque input. the magnitude of rotation and torque on each axis was obtained, as shown in table 1. table 1 was used to select suitable servo motor to rotate the antenna tracker axis. d. telemetry configuration to operate the antenna tracker, radio and telemetry configuration between the gcs, the antenna tracker, and the uav must be set properly as shown in figure 5. telemetry configuration was done in order to avoid telemetry radio signal interference. from figure 5, it was known that radio configuration telemetry was able to use 2 pairs of telemetry radio with different frequencies. the telemetry radio between the gcs and the antenna tracker was using the frequency of 433 mhz, whereas the telemetry radio between the antenna tracker and the uav was using a radio frequency of 915 mhz. figure 4. movement of every axis: (a) elevation axis (pitch); (b) azimuth axis (yaw) figure 3. three-dimensional design of antenna tracker table 1. the magnitude of rotation and torque on every axis axis pinion gear gear ratio rotation speed (rpm) torque out (kg.cm) azimuth (yaw) 30 47 0.6 39.5 47 elevation (pitch) 31 64 0.4 30.0 61.9 g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 36 from figure 5, it can be seen that the 32-bit microprocessor had a function of the antenna tracker controller and adahts uav data router to be displayed at the gcs at once. with such a telemetry configuration, the antenna tracker was able to be operated wireless without interference between the uav and the gcs in the routing of adahrs uav data. e. antenna a directional antenna and an omnidirectional antenna were used in the performance test. the directional antenna used was a 6 dbi 3 element yagi with radiation pattern as shown in figure 6. the omnidirectional antenna gain was 2.1 dbi. both antennas were worked at a frequency of 915 to 928 mhz. f. tracking algorithm the antenna was rotated at that azimuth angle relative to the north pole in order to remain the uav in the radiation pattern of the antenna in the gcs. the azimuth angle was calculated by equations (4)-(7) [11]. ∆φ = φ2 − φ1 (4) y = sin ∆φ ∗ cos ∅2 (5) x = (cos ∅1 ∗ sin ∅2) − (sin ∅1 ∗ cos ∅2 ∗ cos ∆φ) (6) ψ = tan−1 ( y x ) (7) where φ1 is longitude of the gcs, φ2 is longitude of the uav, ∅1 is latitude of the gcs, ∅2 is latitude of the uav. ψ is the azimuth angle that is the position of the uav relative to the north pole. figure 5. telemetry configuration [7] figure 6. radiation pattern 6 dbi 3 element yagi antenna g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 37 the distance between the uav and the gcs was also needed. positions of the uav and the gcs were known, then the latitudinal angle was linear but the longitudinal degree was depended on latitude. distance d between the uav and the gcs can be calculated using the spherical law of cosines equations as follows: ∆φ = φ2 − φ1 (8) ∆∅ = ∅2 − ∅1 (9) d = cos−1(sin∅1 ∗ sin∅2 + cos∅1 ∗ cos ∅2 ∗ cos∆φ) ∗ r (10) where r is average radius of earth (6.371×103 m). by knowing the distance d, altitudes of the uav and the gcs, and vertical angle; the controller can calculate pitch angle by using equations (11) and (12). ∆h = h2 − h1 (11) θ = tan−1 ( ∆h d ) (12) where θ is rotation angle of the antenna tracker to the horizon, h1 is altitude of gcs, h2 is altitude of uav. while the value of d always positive, θ always on the range of −90° to +90° [12]. g. antenna tracker performance when the antenna tracker works, it provided data logs in the memory. the uav provided data logs that can be downloaded via sd card in the 32-bit controller. the antenna tracker performance was tested with a quadcopter-type uav as shown in figure 7. by simulating an area of the disaster monitoring, performance of the antenna tracker was obtained such as tracking accuracy, signal quality (rssi), and the error that occurs on every axis. after the testing was done, the data logs in the sd card of the 32-bit controller were taken and downloaded to a pc for processing. data processing included tracking the accuracy of the antenna tracker by comparing the desired azimuth angle with the actual azimuth angle of the antenna tracker, and the desired elevation angle with the actual antenna tracker elevation angle are shown in figure 8. from figure 8(a) and 8(b), it can be seen that the antenna tracker was able to track the uav accurately. from figure 8(a) and 8(b), the blue line showed the desired azimuth and elevation angle while the red line showed the azimuth and elevation angle that were done by the antenna tracker. with a little error, that was an average of 5.62° on the azimuth axis (yaw) and 1.51° on elevation axis (pitch), respectively. error on each axis can be seen in figure 9. during the test before data recording, uncontrolled movement of the antenna tracker was often occur as shown in figure 10. this uncontrolled motion due to the controller had not worked properly, so the antenna axis motion had not been controlled. this condition was occurred only for a while when the system was started up. from the graph in figure 10, it can be seen that there was a significant error at the beginning of the antenna tracker activation. that was because the gps module had not received the position of at least 6 satellites, so that gps status on gcs was still not fixed. however after 202.091 seconds the antenna tracker had worked normally and accurately. h. signal quality to test signal quality, the received signal strength indicator (rssi) was measured. the rssi comparison was carried out between three measurements: when the antenna tracker was in active condition, without antenna tracker, and with the antenna tracker that use omnidirectional antenna type. the results were plotted in figure 11. figure 11 showed that, when the tracker antenna was activated, the signal quality did not fluctuate significantly. when a high gain directional antenna without tracker is used, the signal quality was fluctuated significantly. in the case that telemetry used only an omnidirectional antenna, the signal quality was fluctuated very significant even the lowest signal quality had occurred when using an omnidirectional antenna. from the above results, it was known that the use of antenna tracker can keep the signal quality constantly without experiencing significant fluctuations. this means that telemetry data can be transmitted securely. figure 7. antenna tracker performance test g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 38 (a) (b) figure 8. antenna tracker performance: (a) azimuth axis (yaw); (b) elevation axis (pitch) figure 9. error on azimuth axis (blue line) and error on elevation axis (red line) g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 39 iv. conclusion from the results of this study it can be concluded that the designed antenna tracker could track the uav accurately with an average error of 5.62° on azimuth axis (yaw) and 1.51° on elevation axis (pitch), respectively. by measuring the received signal strength indicator (rssi) it was known that the signal strength was more constantly maintained when it used a directional high gain antenna with tracker compared with a directional high gain antenna and omnidirectional antenna with no tracker. the use of an antenna tracker was necessary when a directional antenna was used, so that the uav remained in the radiation area of the directional high gain antenna. by doing so, signal quality could be maintained constantly without experiencing any fluctuation. by using this antenna tracker, the data link can be further extended so that an unmanned aircraft will be able to fly further without experiencing signal loss. acknowledgement the authors are grateful for the research funding provided by the ministry of research, technology and higher education of the republic of indonesia through higher education excellent research programme. references [1] p. j. bevelacqua, “antenna arrays: performance limits and geometry optimization,” 2008. [2] “bevelacqua, peter. j., “antenna theory.”, 2009. [online]. available: http://www.antenna-theory.com/. [3] d. f. m. diaz, m. e. r. montilla, and s. suddart, “active tracking position antenna base: a low cost approximation with servo gimbals,” ix lat. am. robot. symp. ieee colomb. conf. autom. control, 2011. [4] m. jeon and d. kwon, “an optimal antenna motion generation using shortest path planning,” adv. sp. res., vol. 59, no. 6, pp. 1435–1449, 2017. [5] a. a. mulla and p. n. vasambekar, “overview on the development and applications of antenna control systems,” annu. rev. control, vol. 41, pp. 47–57, 2016. figure 10. uncontrolled movement (yellow box) figure 11. comparison of signal quality http://www.antenna-theory.com/bevelacqua-dissertation.pdf http://www.antenna-theory.com/bevelacqua-dissertation.pdf http://www.antenna-theory.com/ http://www.antenna-theory.com/ https://doi.org/10.1109/larc.2011.6086855 https://doi.org/10.1109/larc.2011.6086855 https://doi.org/10.1109/larc.2011.6086855 https://doi.org/10.1109/larc.2011.6086855 https://doi.org/10.1016/j.asr.2016.11.018 https://doi.org/10.1016/j.asr.2016.11.018 https://doi.org/10.1016/j.asr.2016.11.018 https://doi.org/10.1016/j.arcontrol.2016.04.012 https://doi.org/10.1016/j.arcontrol.2016.04.012 https://doi.org/10.1016/j.arcontrol.2016.04.012 g. nugroho and d. dectaviansyah / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 32–40 40 [6] y. wang, m. soltani, and d. m. a. hussain, “an attitude heading and reference system for marine satellite tracking antenna,” ieee trans. ind. electron., vol. 64, no. 4, pp. 3095 – 3104, 2017. [7] m. n. soltani, r. i. zamanabadi, and r. wisniewski, “reliable control of ship-mounted satellite tracking antenna,” ieee trans. control syst. technol., vol. 19, no. 1, pp. 221 – 228, 2011. [8] y. yalcin and s. kultulan, “a rooftop antenna tracking system: design, simulation, and implementation,” ieee antennas propag. mag., vol. 51, no. 2, 2009. [9] r. v. gatti and r. rossi, “a dual-polarization slotted waveguide array antenna with polarization-tracking capability and reduced sidelobe level,” publ. ieee trans. antennas propag., vol. 64, no. 4, 2016. [10] h. a. taam et al., “design development and experimental validation of an ebg matrix antenna for tracking application,” int. j. microw. wirel. technol., vol. 9, no. 1, pp. 231–239, 2017. [11] “rfdesign pty ltd,"rfid sports timing mat antenna", 2016. [online]. available: http://rfdesign.com.au/. [12] d. stojcsics and l. somlyai, “improvement methods of short range and low bandwidth communication for small range uavs,” ieee 8th int. symp. intell. syst. informatics, 2010. https://doi.org/10.1109/tie.2016.2633529 https://doi.org/10.1109/tie.2016.2633529 https://doi.org/10.1109/tie.2016.2633529 https://doi.org/10.1109/tie.2016.2633529 https://doi.org/10.1109/tcst.2010.2040281 https://doi.org/10.1109/tcst.2010.2040281 https://doi.org/10.1109/tcst.2010.2040281 https://doi.org/10.1109/tcst.2010.2040281 https://doi.org/10.1109/map.2009.5162072 https://doi.org/10.1109/map.2009.5162072 https://doi.org/10.1109/map.2009.5162072 https://doi.org/10.1109/tap.2016.2526645 https://doi.org/10.1109/tap.2016.2526645 https://doi.org/10.1109/tap.2016.2526645 https://doi.org/10.1109/tap.2016.2526645 https://doi.org/10.1017/s1759078715001245 https://doi.org/10.1017/s1759078715001245 https://doi.org/10.1017/s1759078715001245 http://rfdesign.com.au/ http://rfdesign.com.au/ https://doi.org/10.1109/sisy.2010.5647224 https://doi.org/10.1109/sisy.2010.5647224 https://doi.org/10.1109/sisy.2010.5647224 mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.22-32 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. performance comparison of consensus protocol and l-approach for formation control of multiple nonholonomic wheeled mobile robots ali alouache*, qinghe wu school of automation, beijing institute of technology haidian district 100081, beijing, pr china received 21 january 2017; received in revised form 28 april 2017; accepted 3 may 2017 published online 31 july 2017 abstract this paper investigates formation control of multiple nonholonomic differential drive wheeled mobile robots (wmrs). assume the communication between the mobile robots is possible where the leader mobile robot can share its state values to the follower mobile robots using the leader-follower notion. two approaches are discussed for controlling a formation of nonholonomic wmrs. the first approach is consensus tracking based on graph theory concept, where the linear and angular velocity input of each follower are formulated using first order consensus protocol, such that the heading angle and velocity of the followers are synchronized to the corresponding values of the leader mobile robot. the second is l- approach (distance angle) that is developed based on lyapunov analysis, where the linear and angular velocity inputs of each follower mobile robot are adjusted such that the followers keep a desired separation distance and deviation angle with respect to the leader robot, and the overall system is asymptotically stable.the aim of this paper is to compare the performances of the presented methods for controlling a formation of wheeled mobile robots with matlab simulations. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: nonholonomic wmr; the leader-follower structure; graph theory; consensus protocol; l-approach i. introduction in the recent years there are a lot of interest to the design of mobile robots i.e. wheeled mobile robots (wmrs) [1, 2, 3, 4], due to their use in the societal and industrial applications. unlike the majority of industrial robots that can move only in a specific workspace, mobile robots have the special feature of moving around freely within a predefined workspace to achieve their desired goals. this mobility capability makes mobile robots suitable for a large repertory of applications in structured and unstructured environments [5, 6, 7]. in certain time, the complexity of robot’s tasks may increase, and a single mobile robot may not accomplish several tasks simultaneously or efficiently. to solve this problem, formations of these robots are called to work in parallel. there were many advantages when a team of mobile robots move in formation, such as increasing the efficiency, the accuracy, the robustness of the system to external effect, decreasing the system cost and increasing probability of success. a group of robots can be used for accomplishing many tasks such as moving large awkward objects, terrain model acquisition, planetary exploration, surveillance applications [8, 9, 10, 11]. formation of mobile robots control methods can be partitioned into three class approaches: virtual structure approach [12, 13], behavioral approach [14, 15] and the leaderfollower approach [16, 17, 18]. in the leader-follower approach, one of the vehicles is designated as the leader, with the rest of the vehicles designated as followers. the basic idea is that the followers track the position and orientation of the leader with some prescribed (possibly time-varying) offset. there are numerous variations on the leaderfollower topic including designating multiple leaders, forming a chain (vehicle tracks vehicle), and other tree topologies. there have been a number of works of leader-following mobile robotics. the leader * corresponding author. tel: +86 188 0110 3264 e-mail address: alouache15@yahoo.fr https://dx.doi.org/10.14203/j.mev.2017.v8.22-32 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.22-32 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.22-32&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ tel:+86%20188%200110%203264 d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 23 following technique based on the fuzzy logic approach is proposed for formation of wheeled mobile robots [18, 19]. feedback linearization techniques are used to derive tracking control laws for nonholonomic robots that are used for leader-following. in addition, the authors used potential fields for obstacle avoidance [20]. a combination of a linear model predictive control and input-output feedback linearization is implementedon a team of wmrs in order to accomplish a formation task [21]. controlling a formation that comprises large number robots poses some problems such as high communication load, high energy consumption and lack of robustness. therefore, controlling some formation using graph theory is a solution [22] that increases the reliability of mathematical analysis, the effectiveness of realization, and reducing the power consumption with real robots [22]. this paper discusses two approaches for controlling a formation of multiple nonholonomic differential drive wheeled mobile robot based on the leader-follower structure. the first approach is consensus tracking based on graph theory concept [23]. each wmr has single integrator nonlinear dynamics. the formation is described by a graph; each node of the graph represents a wmr, which is connected to its neighbours through an adjacency matrix. each node also has some effects on its neighbours for sharing communication information hence the leader. wmr can share its state information with the neighbor follower. notice that the wmr receiving information about the input reference commands is named as the leader mobile robot and the other robots are follower robots. the linear and angular velocity inputs of each follower are formulated using first order consensus protocol, as well as the heading angle and velocity of the followers are synchronized to the corresponding values of the leader robot. the wmrs are synchronized to move off in formation with the same speed and directed orientation using consensus protocols. the separation distance and deviation angle between the leader and the follower robot motion are not controlled through the consensus protocol. the second approach is called l-(also called distance angle) which aims to control the desired distance and deviation angle between the leader and the follower robot. this approach is formulated based on lyapunov analysis [24]. the linear and angular velocities of the follower are formulated such that the system is asymptotically stable in the sense of lyapunov. in order to prescribe a formation maneuver, the leader’s velocities commands are needed to be specified from the desired position and angle between the leader and the follower. related to the existing works on formation control of mobile robots based on the leader-follower structure, the main contribution of this paper is comparing the performances and the characteristics of consensus protocol with l-approach for controlling a formation of wheeled mobile robots using matlab simulations. ii. wmr kinematic figure 1 displays a typical nonholonomic differential drive wheeled mobile robot moving on the x-y plane with center of mass c and initial pose parameters. the wmr has two driving wheels mounted on the same axis and a free front wheel. the two driving wheels are derived to achieve both the orientation and translation pose. the derived nonlinear kinematic model which expresses the motion of the wmr is [ �̇�(𝑡) �̇�(𝑡) �̇�(𝑡) ] = [ 𝑐𝑜𝑠𝜃(𝑡) 𝑠𝑖𝑛𝜃(𝑡) 0 0 0 1 ] [ 𝑣(𝑡) 𝑤(𝑡) ] (1) the following (𝑥(𝑡), 𝑦(𝑡), 𝜃(𝑡))𝑇 is defined as the robot pose cartesian coordinates at instant time t, where (x(t),y(t)) represents the position of the mobile robot by the fixed cartesian coordinates, and the angle 𝜃(𝑡), orientation relatively to the x-axis. (𝑥0, 𝑦0, 𝜃0) is the initial pose coordinates of the robot center of mass c. 𝑣(𝑡), 𝑤(𝑡) and 𝜃(𝑡) are respectively the linear velocity, the angular velocity, and the heading angle of the robot. the kinematic model of equation (1) describes the velocities of the vehicle but not the forces or torques that cause the velocity. the mechanical structure of the wmr is nonholonomic, it satisfies the following constraint. ẋ(𝑡)𝑠𝑖𝑛𝜃(𝑡) − ẏ(𝑡)𝑐𝑜𝑠𝜃(𝑡) = 0 (2) this constraint means that the wmr cannot move in the direction of the wheel axis (i.e. y). iii. formation consensus tracking the leader-follower concept can be modelled geometrically as shown in figure 2. the robots are identical and their motion equations are given by equation (1). the formation might have more robots, therefore this is only to define the symbol of the robots. rl and rf denote the leader and the follower robot, respectively. according to the notation defined in equation (2), the states and the inputs of rl and rf are denoted as (xl ,yl ,l), (xf ,yf ,f), (vl ,wl), and (vf ,wf), respectively. figure 1. wheeled mobile robot motion on the x-y plane a. alouache and q. wu. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 24 a. graph theory considering the formation of wmrs that is interconnected and able to share communication among robots, this communication network is modeled as a graph with directed edges corresponding to the allowed flow of information between the systems. the systems are modelled as the nodes in the graph that called agents. a graph is a pair of g=(v, e) with 𝑉 = {𝑣1, 𝑣2, … 𝑣𝑁} is a set of n nodes or vertices and e a set of edges or arcs. elements of e are denoted as (vi, vj) which are termed an edge or arc from vi to vj, and represented as an arrow with tail at vi and head at vj. it is assumed that the graph is simple by considering that (𝑣𝑖, 𝑣𝑖) ∉ 𝐸, ∀𝑖 is no self-loops, and no multiple edges between the same pairs of nodes. edge (vi, vj) is said to be out going to node vi and incoming to vj ; and node vi is known as the major while vj is the minor. the in-degree of vi is the number of edges having vi as a head. the out-degree of a node vi is the number of edges having vi as a tail. the set of (in-) neighbors of a node vi is 𝑁𝑖 = {𝑣𝑗: (𝑣𝑗, 𝑣𝑖) ∈ 𝐸}, i.e., the set of nodes with edges incoming to vi. the number of neighbors |ni| of node vi is equal to its in-degree. in the case that teh in degree equals the out-degree for all nodes vi∈ v, then the graph is said to be balanced. if (𝑣𝑖, 𝑣𝑗) ∈ 𝐸 ⇐ (𝑣𝑗, 𝑣𝑖) ∈ 𝐸, ∀𝑖, 𝑗, then the graph is said to be bidirectional, otherwise it is termed as directed graph or digraph, associate with each edge (𝑣𝑗, 𝑣𝑖)∈ e a weight aij (note the order of the indices in this definition), assume that the non-zero weights are strictly positive. a graph is said to be undirected if 𝑎𝑖𝑗 = 𝑎𝑗𝑖, ∀𝑖, 𝑗 , that is, if it is bidirectional and the weights of edges (vi, vj) and (vj , vi) are the same. a directed path is a sequence of nodes 𝑣0, 𝑣1, … , 𝑣𝑟 , such that the (𝑣𝑖, 𝑣𝑖+1) ∈ 𝐸, 𝑖 ∈ {0,1, … , 𝑟 − 1}. node vi is said to be connected to node vj if there is a directed path from vi to vj. the distance from vi to vj is the length of the shortest path from vi to vj. graph g is said to be strongly connected if vi, vj are connected for all distinct nodes vi, vj∈ v. for bidirectional and undirected graphs, if there is a directed path from vi to vj, then there is a directed path from vj to vi, and the qualifier is ‘strongly’ omitted. a directed tree is a connected digraph where every node except one, called the root, has in-degree equal to other. a spanning tree of a digraph is a directed tree formed by graph edges that connects all the nodes of the graph. a graph is said to have a spanning tree if a subset of the edges forms a directed tree. this is equivalent to say that all nodes in the graph are reachable from a single (root) node by following the edge arrows. a graph may has multiple spanning trees. define the root set or leader set of a graph as the set of nodes that are the roots of all spanning trees. if a graph is strongly connected, it contains at least one spanning tree. in fact, if a graph is strongly connected, then all nodes are root nodes. b. consensus tracking algorithm multi agent systems with the nodes of the graph have a scalar single integrator given by the following equation �̇�𝑖 = 𝑢𝑖 (3) with 𝑥𝑖, 𝑢𝑖 ∈ 𝑅.a as basic control design that play role as multi agent consensus tracking. to implement the role as a multi agent consensus, a distributed control protocol that drives all states to the same values xi = xj, ∀𝑖, 𝑗 has to be fulfilled. this value is known as a consensus value. the local control protocols for each agent i is given as follow 𝑢𝑖 = ∑ 𝑎𝑖𝑗(𝑥𝑗 − 𝑥𝑖)𝑗∈𝑁𝑖 . (4) with aij is the graph edge weights of the adjacency matrix 𝐴𝑛 ∈ 𝑅 𝑛×𝑛 associated with graph g at time t, xi is the information state of the agent i and xj the information of the corresponding neighbor jth agent. this control distributed in that is only depends on the immediate neighbors ni of node i in the graph topology. remark 1: note that if these states are equal (or similar), this leads to zero i.e.�̇�𝑖 = 𝑢𝑖 = 0. remark 2: setting aij=0 denotes the fact that the vehicle i cannot receive information from the vehicle j. the local voting protocol of equation (4) guarantees consensus of the multi agent singleintegrator dynamics of equation (3) if and only if the graph has a spanning tree. if the graph is strongly connected, then it has a spanning tree and consensus is reached. c. formation consensus protocol the leader wmr in figure 2 is moving with linear and angular velocity (vl ,wl). the local voting protocol of equation (4) is employed to derive the consensus protocols for formation consensus. the heading angle of the follower robot is synchronized to the leader by the following consensus protocol �̇�𝑓 = 𝜃𝑙 − 𝜃𝑓 (5) figure 2. multiple wmrs motion on the x-y plane d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 25 therefore, the angular velocity of the follower robot is given as follow 𝑤𝑓 = 𝜃𝑙 − 𝜃𝑓. (6) another consensus algorithm is applied on follower robot to synchronize the follower’s velocity to the leader’s speed �̇�𝑓 = 𝑣𝑙 − 𝑣𝑓 (7) from equation (7), the linear velocity of the follower robot is given as follow 𝑣𝑓 = ∫ (𝑣𝑙 − 𝑣𝑓)𝑑𝑡 (8) figure 3 illustrates the general overview of the leaderfollower control system, developed based on consensus protocol. iv. formation control using l-approach the leader-follower structure for a formation wheeled mobile robots l-approach is displayed in figure 4. the different parameters of the l-approach (distance-angle) are indicated in figure 4. as shown in figure 4, the variable d denotes the relative distance between the leader and the follower robot. the parameter  indicated in figure 4 denotes the bearing angle between the horizontal direction and the line connecting the leader and the follower. is the relative angle between the follower and the leader of mobile robot. the relative distance between the leader and the follower robot d is defined by the following equation 𝐷 = √(𝑥𝑙 − 𝑥𝑓) 2 + (𝑦𝑙 − 𝑦𝑓) 2 (9) the angular position of the follower robot relative to the leader robot is defined by the following equations { 𝛼 = 𝜃𝑓 − 𝜑 𝛽 = 𝜃𝑙 − 𝜑 (10) the tracking errors between the desired values and the actual values of the robots are given this following equation { 𝑒𝐷 = 𝐷𝑑 − 𝐷 𝑒𝛼 = 𝛼𝑑 − 𝛼 (11) to derive the linear and angular velocity inputs of the follower robot, the following steps are carried out. step 1: in this step the leader’s motion is not considered, and the stability of the follower robot is proved. first of all, the time derivatives of the parameters d and 𝛼 are given as follow { �̇� = −𝑣𝑓𝑐𝑜𝑠𝛼 �̇� = − ( 𝑣𝑓 𝐷 ) 𝑠𝑖𝑛𝛼 (12) the lyapunov candidate function is taken as follow { 𝑉1 = 1 2 𝑒𝐷 2 𝑉2 = 1 2 𝑒𝛼 2 𝑉3 = 𝑉1 + 𝑉2 (13) notice that the functions v1 and v2 are considered as the quadratic values of the tracking errors 𝑒𝐷 and 𝑒𝛼 respectively, and the function v3 is the sum of the quadratic tracking errors. the time derivative of the function 𝑉1 is given by the following equation �̇�1 = −𝑒𝐷𝑣𝑓𝑐𝑜𝑠𝛼 (14) in order to comply the lyapunov stability condition and to make �̇�1 non-positive, it is obvious to choose 𝑣 as follows 𝑣𝑓 = 𝐾𝑣𝑒𝐷 cos 𝛼 (15) 𝐾𝑣 is a positive gain. the time derivative of 𝑉2 is given as follows �̇�2 = 𝛼(𝑤𝑓 + 𝑣𝑓 𝐷 𝑠𝑖𝑛𝛼) (16) where wf is chosen such that �̇�2 is non-positive, and it is given as follows 𝑤𝑓 = −𝑘𝑤 𝛼 − 𝑣𝑓 𝐷 𝑠𝑖𝑛𝛼 (17) where 𝑘𝑤 is a positive gain. the functions �̇�1 of equation (14) and �̇�2 of equation (16) are made nonpositive yield that �̇�3 is non-positive too and the system is asymptotically stable. figure 3. an overview of the leader follower motion consensus figure 4. parameter of the leader follower l-approach a. alouache and q. wu. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 26 step 2: the motion of the leader robot is taken into consideration, and the stability of the leader-follower system is analyzed. therefore the time derivatives of the parameters d and 𝛼 become { �̇� = 𝑣𝑙𝑐𝑜𝑠𝛽 − 𝑣𝑓𝑐𝑜𝑠𝛼 �̇� = ( 𝑣𝑙 𝐷 )𝑠𝑖𝑛𝛽 − ( 𝑣𝑓 𝐷 )𝑠𝑖𝑛𝛼 (18) the laypunov function adopted here is the same form as to the lyapunov candidate 𝑉3 of step 1, thus 𝑉3 is the quadratic sum of tracking errors. the time derivative of v3 is carried out as in the same as step 1. to make the function v̇3 non-positive, the control laws are defined as follow { 𝑣𝑓 = 𝑣𝑙 𝑐𝑜𝑠𝛽 𝑐𝑜𝑠𝛼 − 𝐾𝑣𝑒𝐷 cos 𝛼 𝑤𝑓 = −𝑘𝑤 𝛼 − 𝑣 𝐷 𝑠𝑖𝑛𝛼 + 𝑣𝑙 𝐷 𝑠𝑖𝑛𝛽 (19) where 𝐾𝑣 and 𝑘𝑤 are positive gains. it can be easily checked that vf and wf of equation (19) create the non-positive function of �̇�3 non-positive and the whole system is considered asymptotically stable. figure 5 gives a general overview of the control system developed by the leader-follower l-approach. it comprises the leader robot, the follower robot, and the lyapunov based controller. as depicted in figure 5, the inputs of the control system are as follow  leader’s velocities (vl, wl).  desired distance 𝐷𝑑 and desired deviation angle 𝛼𝑑 of the follower with respect to the leader robot. the leader-follower formation achieves the desired values 𝐷𝑑 and 𝛼𝑑 ,when the tracking errors 𝑒𝛼 and 𝑒𝐷 converge to zero. v. simulation results this section provides simulation examples for testing and comparing the performances of the presented approaches i.e. consensus protocol and the lapproach. in the forthcoming, it is considered that all the wmrs of the formation used in the examples are identical, where the motion of each wmr is expressed by the model of equation (1). a. example 1 in this example, the consensus protocol approach are tested for a formation of five wmrs which comprises one leader wmr (l0) and four followers wmrs (f1, f2, f3, f4). at the initial instant t=0, the initial coordinates of the five wmrs poses on the x-y plane are given as follows  the leader l0 (x0(0), y0(0), θ0(0)) = (0,2, π 3 )  the follower f1(x1(0), y1(0), θ1(0)) = (2,2,0)  the follower f2(x2(0), y2(0), θ2(0)) = (0,0, π)  the follower f3(x3(0), y3(0), θ3(0)) = (1,0, −π 2 )  the follower f4(x4(0), y4(0), θ4(0)) = (0, −1, π 2 ) the communication topology of the formation of wmrs is described by the digraph of figure 6 which has a spanning tree. the arrows between each of two wmrs of the formation indicate that the communication information is flowing in the arrow direction between the wmrs. the adjacency matrix which is describing the communication topology among the five wmrs of figure 6 is given by the following matrix 𝐴5×5 = [ 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0] the information about the reference values is available only for the leader wmr l0. the desired values for the reference velocity and the reference heading are taken as follows { 𝑉𝑟𝑒𝑓 = 1𝑚/𝑠 𝜃𝑟𝑒𝑓 = 𝜋 4 𝑟𝑎𝑑 using the reference values (𝑉𝑟𝑒𝑓, 𝜃𝑟𝑒𝑓) , the consensus tracking for the formation is realized as illustrated by the control system of figure 3. figure 7 displays the results of synchronizing the headings of the robots to the reference value. note that all the headings reach the same consensus value 𝜃𝑟𝑒𝑓. figure 5. controller overview of the leader follower l-approach d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 27 figure 8 illustrates the results of synchronizing all the velocities of the wmrs to the velocity reference value vref. figure 9 shows the motion of the wmrs on the (x-y) plane, each wmr starts from its corresponding initial pose, and all the robots converge simultaneously to the same heading value and move off in a formation together with same speed. b. example 2 in this example, the consensus protocol is compared with the l-approach. consider a formation of wheeled mobile robots that comprises one leader and two follower mobile robots. at the initial instant t=0, considerate is considered that the coordinates of the robots as follow figure 6. the tree-shaped graph for a network of four followers with a leader figure 7. the consensus of the headings figure 8. the consensus of the velocities figure 9. motion consensus of the formation of wmrs in the x-y plane a. alouache and q. wu. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 28  the leaderrl (𝑥𝑙(0), 𝑦𝑙(0), 𝜃𝑙(0)) = (0,0,0)  the follower #1rf1(𝑥𝑓1(0), 𝑦𝑓1(0), 𝜃𝑓1(0)) = (0,2,0)  the follower #2rf2(𝑥𝑓2(0), 𝑦𝑓2(0), 𝜃𝑓2(0)) = (0,4,0) by a simple calculation, the initial distance between the robots rl and rf1 is d1=2. the initial distance between the robots rl and rf2 is d2=4. the input velocities of the leader mobile are shown in the figure 10. notice that the input linear and angular velocities are different from the previous example. 1) consensus tracking to realize formation of consensus tracking, the control system shown in figure 3 is employed. the communication topology among the robots is given as indicated in figure 11. the arrows indicate that the information between the mobile robots is flowing in the arrow direction. notice that the communication graph has a spanning tree. the adjacency matrix describing the graph of figure 11 is given as follows 𝐴3×3 = [ 0 1 0 0 0 1 0 0 0 ] figure 12 shows the time histories of the linear velocity for the three mobile robots. figure 13 displays the time histories for the angular velocity for the three mobile robots. figure 14 displays the result of the headings consensus, note that the headings angles of the follower mobile robots are synchronized to the heading of the leader robot. figure 15 shows the trajectories of the leader and the followers mobile robots on the (x-y) plane, where all the mobile robots start from their corresponding initial poses. note that the three robots move off in formation simultaneously with the same heading angle and speed. the relative distances among the three mobile robots remain the same during the whole time of the simulation. 2) the leader-follower l- approach it is desired that the distance and deviation angle between the leader rl and the follower robot #1 rf1, have the following values { 𝐷𝑑1 = 1 𝛼𝑑1 = 0.15 𝑟𝑎𝑑 the desired distance and deviation angle between the leader rl and the robot follower #2 rf2 are given as follow { 𝐷𝑑2 = 1.5 𝛼𝑑2 = 0.15 𝑟𝑎𝑑 figure 16 shows the time evolution of the distance between the robots, notice that both distances converge to the desired distances values 𝐷𝑑1 and 𝐷𝑑2, respectively. the errors of the distances between the robots are depicted in figure 17, where both errors convergeto zero. figure 18 shows the time evolution of the deviation angles between the robots, both converge to the desired angles 𝛼𝑑1 and 𝛼𝑑2 . the angles errors between the mobile robots are depicted in figure 19, where both errors converge to zero. figure 20 displays the trajectories of the three mobile robots on the x-y plane. it is clear that the three mobile robots move forward in a formation and keeping the desired distance and angle with respect to the leader mobile robot. comparing the results in figure 15 and figure 20, it can be concluded that the l- approach is controlling the distance and deviation angle between the robots compared to consensus protocol approach. the followers’ trajectories displayed in figure 15 and figure 20, demonstrated that in case of consensus protocol then the followers repeat simultaneously the same trajectory of the leader mobile robot; on the other hand, by using the l-approach the followers perform tracking of the leader’s trajectory while maintaining the desired distance and deviation angle between the robots. figure 10. the input velocities for the leader mobile robot figure 11. communication topology among the mobile robot d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 29 figure 12. time histories for the robots’ linear velocity figure 13. time histories for the robots’ angular velocity figure 14. headings consensus for the formation of mobile robots figure 15. mobile robots’ trajectories based on consensus protocol approach a. alouache and q. wu. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 30 figure 16. time evolution of the distances between the robots figure 17. distance errors between the mobile robots figure 18. time evolution of the deviation angles between the robots figure 19. errors of the angles between the mobile robot d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 31 from the results of example 1 and example 2, the main characteristics and performances of the consensus and l-approach can be summarized as given in table 1. the comparison given in table 1 is valid for a number of robots. vi. conclusion in this paper we have compared the performances of two different approaches (i.e. consensus protocol and l- approach for formation control of multiple nonholonomic differential drive wheeled mobile robots based on the leader-follower structure. consensus protocol is developed based on graph theory concepts. a graph is used to represent the communication exchange between the robots. each node of the graph represents a single robot, which is connected to its neighbours by an adjacency matrix, where each node has some effects on its neighbours for sharing communication information. the mobile robot that receives reference velocities commands is named the leader and others robots are the followers. the input velocities of each follower robot are formulated using first order consensus protocol. it is shown that the consensus is achieved if the graph has a spanning tree. by using the consensus protocol, the heading angle and velocity of the follower robots are synchronized to the same values with the leader, and we have verified it by a simulation example using a formation of five wmrs. the l-approach is developed based on the lyapunov theory, where the linear and angular velocity of the follower robots are adjusted such that the follower keeps a separation distance and deviation angle with respect to the leader, moreover the whole system is asymptotically stable in the sense of lyapunov. the effectiveness of the two methods are evaluated and compared by simulation examples. the simulation results demonstrated that the follower robots repeat simultaneously the trajectory of the leader when the consensus protocol is adopted. on the other hand, the follower robots perform trajectory tracking of the leader’s trajectory using the l- approach, while maintaining a desired distance and angle between the mobile robots. consensus protocol approach is considered an advantageous because it is faster, and it consumes less power in real time applications. the l- approach is effective for controlling the follower robots to keep the desired separation distance and deviation angle relative to the leader mobile robot. in the future works it is necessary to develop both algorithms with obstacle avoidance. acknowledgement this work was supported by the national natural science foundation of china under grant no. 61321002. figure 20. robots’trajectories on the x-y plane based on l-approach table 1. comparison of consensus and l-approach consensus approach l- approach principle algebraic approach (graph theory) geometrical approach (distance angle) pros reliable mathematical analysis, and fast convergence low power consumption stability of the system, effective convergence to the desired performances cons communication problems in practice which cause the instability of the formation. -lack of robustness for dynamic changing the geometry of the formation. -high power consumption with large number of robots a. alouache and q. wu. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 22–32 32 references [1] y. inoue et al., “design of omnidirectional mobile robots with acrobat wheel mechanisms,” ieee int. conf. intell. robot. syst., pp. 4852–4859, 2013. [2] t. jacobs et al., “design of wheel modules for non-holonomic, omnidirectional mobile robots in context of the emerging control problems,” in robotik 2012; 7th german conference on robotics, 2012. [3] m. lauria et al., “design and control of a four steered wheeled mobile robot,” , iecon 2006-32nd, paris, pp. 4020–4025, 2006. [4] z. zhang et al., “design and implementation of two-wheeled mobile robot by variable structure sliding mode control,” in 2016 35th chinese control conference (ccc), 2016, no. c, pp. 5869–5873. [5] l. pacheco and n. luo, “testing pid and mpc performance for mobile robot local path-following,” int. j. adv. robot. syst., p. 1, 2015. [6] w.-y. lee et al., “mobile robot navigation using wireless sensor networks without localization procedure,” wirel. pers. commun., vol. 62, no. 2, pp. 257–275, 2012. [7] s. hiroi and m. niitsuma, “building a map including moving objects for mobile robot navigattion in living environtment,” ieee, pp. 1–2, 2015. [8] z. yan et al., “a survey and analysis of multi-robot coordination,” int. j. adv. robot. syst., vol. 10, 2013. [9] m. defoort et al., “sliding-mode formation control for cooperative autonomous mobile robots,” ieee trans. ind. electron., vol. 55, no. 11, pp. 3944–3953, 2008. [10] j. r. oliveira et al., “integration of virtual pheromones for mapping / exploration of environments by using multiple robots,” pp. 835–840, 2014. [11] r. mendonc et al., “a cooperative multi-robot team for the surveillance of shipwreck survivors at sea,” pp. 2–7, 2016. [12] h. su et al., “flocking of multi-agents with a virtual leader part ii: with a virtual leader of varying velocity,” proc. ieee conf. decis. control, vol. 54, no. 2, pp. 1429–1434, 2007. [13] j. ghommam et al., “formation path following control of unicycle-type mobile robots,” rob. auton. syst., vol. 58, no. 5, pp. 727–736, 2010. [14] l. ren et al., “dynamic and optimized formation switching for multiple mobile robots in obstacle environments,” robot, vol. 35, no. 5, p. 535, 2013. [15] d. xu et al., “behavior-based formation control of swarm robots,” math. probl. eng., vol. 2014, 2014. [16] k. h. kowdiki et al., “leader-follower formation control using artificial potential functions: a kinematic approach,” adv. eng. sci. manag. (icaesm), 2012 int. conf., pp. 500–505, 2012. [17] j. shao et al., “leader-following formation control of multiple mobile robots,” proc. 2005 ieee int. symp. on, mediterrean conf. control autom. intell. control. 2005., no. id, pp. 808–813, 2005. [18] a. bazoula et al., “formation control of multi-robots via fuzzy logic technique mobile robot modeling modeling of leader-follower formation,” communications, vol. iii, no. may 2008, pp. 179–184, 2008. [19] m. h. amoozgar et al., “a fuzzy logic-based formation controller for wheeled mobile robots,” ind. robot an int. j., vol. 38, pp. 269–281, 2011. [20] j. dong et al., “formation control of multirobot based on i / o feedback linearization and potential function,” vol. 2014, pp. 1–7, 2014. [21] m. a. kamel and y. zhang, “decentralized leader-follower formation control with obstacle avoidance of multiple unicycle mobile robots,” 2015 ieee 28th can. conf. electr. comput. eng., pp. 406–411, 2015. [22] j. c. barca et al., “controlling formations of robots with graph theory,” adv. intell. syst. comput., vol. 194 aisc, no. vol. 2, pp. 563–574, 2013. [23] w. ren and n. sorensen, “distributed coordination architecture for multi-robot formation control,” rob. auton. syst., vol. 56, no. 4, pp. 324–333, 2008. [24] s. a. panimadai ramaswamy and s. n. balakrishnan, “formation control of car-like mobile robots: a lyapunov function based approach,” 2008 am. control conf., pp. 657– 662, 2008. mev j. mechatron. electr. power veh. technol 07 (2016) 7-20 journal of mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 www.mevjournal.com © 2016 rcepm lipi all rights reserved. open access under cc by-nc-sa license. doi: 10.14203/j.mev.2016.v7.7-20. accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ministry of rthe) 1/e/kpt/2015. a cfd model for analysis of performance, water and thermal distribution, and mechanical related failure in pem fuel cells maher a.r. sadiq al-baghdadi* department of mechanical engineering, faculty of engineering, university of kufa, najaf, kufa, iraq received 25 january 2016; received in revised form 03 may 2016; accepted 08 may 2016 published online 29 july 2016 abstract this paper presents a comprehensive three-dimensional, multi-phase, non-isothermal model of a proton exchange membrane (pem) fuel cell that incorporates significant physical processes and key parameters affecting the fuel cell performance. the model construction involves equations derivation, boundary conditions setting, and solution algorithm flow chart. equations in gas flow channels, gas diffusion layers (gdls), catalyst layers (cls), and membrane as well as equations governing cell potential and hygro-thermal stresses are described. the algorithm flow chart starts from input of the desired cell current density, initialization, iteration of the equations solution, and finalizations by calculating the cell potential. in order to analyze performance, water and thermal distribution, and mechanical related failure in the cell, the equations are solved using a computational fluid dynamic (cfd) code. performance analysis includes a performance curve which plots the cell potential (volt) against nominal current density (a/cm2) as well as losses. velocity vectors of gas and liquid water, liquid water saturation, and water content profile are calculated. thermal distribution is then calculated together with hygro-thermal stresses and deformation. the cfd model was executed under boundary conditions of 20°c room temperature, 35% relative humidity, and 1 mpa pressure on the lower surface. parameters values of membrane electrode assembly (mea) and other base conditions are selected. a cell with dimension of 1 mm x 1 mm x 50 mm is used as the object of analysis. the nominal current density of 1.4 a/cm2 is given as the input of the cfd calculation. the results show that the model represents well the performance curve obtained through experiment. moreover, it can be concluded that the model can help in understanding complex process in the cell which is hard to be studied experimentally, and also provides computer aided tool for design and optimization of pem fuel cells to realize higher power density and lower cost. key words: cfd; pem; fuel cell; multi-phase; hygro thermal stress. i. introduction water management is one of the critical operation issues in proton exchange membrane fuel cells (pmfcs). spatially varying concentrations of water in both vapour and liquid form are expected throughout the cell because of varying rates of production and transport. water emanates from two sources i.e. the product water from the oxygen-reduction reaction in the cathode catalyst layer and the humidification water carried by the inlet streams or injected into the fuel cell [1]. one of the main difficulties in managing water in a pemfc is the conflicting requirements of the membrane and the catalyst gas diffusion layer (gdl). on the cathode side, excessive liquid water may block or flood the pores of the catalyst layer, the gdl or even the gas channel, thereby inhibiting or even completely blocking oxygen mass transfer. on the anode side, as water is dragged toward the cathode via electro-osmotic transport, dehumidification of the membrane may occur, resulting in deterioration of protonic conductivity. in the extreme case of complete drying, local burnout of the membrane can result. devising better water management is a key issue. thermal management is also required to remove the heat produced by the electrochemical reaction in order to prevent drying out of the membrane, which in turn can result not only in * corresponding author. tel: +96-47719898955 e-mail: mahirar.albaghdadi@uokufa.edu.iq http://dx.doi.org/10.14203/j.mev.2016.v7.1-6 tel:%2b9647719898955 m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 8 reduced performance but also in eventual rupture of the membrane [2]. thermal management is also essential for controlling the water evaporation or condensation rates. the difficult experimental environment of fuel cell systems has stimulated efforts to develop models that could simulate and predict multi-dimensional coupled transport of reactants, heat, and charged species using cfd methods. a comprehensive model should include equations and numerical relations needed to fully define fuel cell behavior over the range of interest. early multidimensional models described gas transport in the flow channels, gas diffusion layers, and the membrane [3-5]. iranzo et al. [6] developed a multi-phase, two-dimensional model to describe the liquid water saturation and flood effect, and have been studied transport limitations due to water build up in the cathode catalyst region. djilali [7] developed a cfd multiphase model of a pemfc. this model provides information on liquid water saturation and flood under various conditions, however it does not account for water dissolved in the ion-conducting polymer to calculate water content through the membrane. hu et al. [8] and fouquet [9] developed an isothermal, three-dimensional, twophase model for a pemfc. their model describes the transport of liquid water within the porous electrodes and water dissolved in the ionconducting polymer. the model is restricted to constant cell temperature. the need for improving lifetime of pemfcs necessitates that the failure mechanisms be clearly understood, so that new designs can be introduced to improve long-term performance. weber and newman [10] developed onedimensional model to study the stresses development in the fuel cell. bograchev et al. [11] studied the hygro and thermal stresses in the fuel cell caused by step-changes of temperature and relative humidity. however, their model is two-dimensional. in addition, constant temperature was assumed at each surface of the membrane. an operating fuel cell has various local conditions of temperature, humidity, and power generation across the active area of the fuel cell. nevertheless, no models have yet been published to incorporate hygro-thermal stresses in threedimension. therefore, in order to acquire a complete understanding of the damage mechanisms in the membranes, mechanical response under steady-state hygro-thermal stresses should be modelled and studied under real cell operation conditions. ii. model description this paper presents a comprehensive threedimensional, multi-phase, non-isothermal model of a pemfc. it accounts for both gas and liquid phase. it includes the transport of gaseous species, liquid water, protons, energy, and water dissolved in the ion-conducting polymer. the model features an algorithm to improve prediction of the local current density distribution. it takes into account convection and diffusion of different species, heat transfer, and electrochemical reactions. it also incorporates the effect of hygrothermal stresses. more specifically, this paper describes the development of the model, the determination of properties for use in the model, the validation of the model using experimental data, and the application of the model to explain observed experimental phenomena. formulas governing the process inside a pemfc have already been disclosed in the previous papers [20-24]. in order to make it self-content to some extent, some important equations are re-presented. a. computational domain in order to save computing resources and shorten simulation times, computational domain is limited to one straight flow channel. it consists of gas flow channels, and membrane electrode assembly (mea) as shown in figure 1. b. model equations 1) gas flow channels in the fuel cell channels, the gas-flow field is obtained by solving the steady-state navierstokes equations. the continuity equations for the gas phase and the liquid phase inside the channel is given by: figure 1. computational domain m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 9 ( ) 0g g gr ρ∇⋅ =u (1) ( ) 0=⋅∇ lllr uρ (2) the following momentum equations are solved in the channels, and they share the same pressure field. ( ) ( )[ ]tggggg ggggg pr uu uuu ∇⋅∇+      ⋅∇+∇− =∇−⊗⋅∇ µµ µρ 3 2 (3) ( ) ( )[ ]tlllll lllll pr uu uuu ∇⋅∇+      ⋅∇+∇− =∇−⊗⋅∇ µµ µρ 3 2 (4) the mass balance is described by the divergence of the mass flux through diffusion and convection. multiple species are considered in the gas phase only, and the species conservation equation in multi-component, multi-phase flow can be written in the following expression for species i: ( ) 0 1 =             ∇ +⋅ +∑       ∇ −+      ∇ +∇− ⋅∇ = t t dyr p p yx m m yy m m dyr t igigg n j jjjj j ijigg uρ ρ (5) where the subscript i denotes oxygen at the cathode side and hydrogen at the anode side, and j is water vapour in both cases. nitrogen is the third species at the cathode side. the maxwell-stefan diffusion coefficients of any two species are dependent on temperature and pressure. they can be calculated according to the empirical relation based on kinetic gas theory [12]: 21 23131 375.1 1110         +               ∑+      ∑ × = − ji k kj k ki ij mm vvp t d (6) in this equation, pressure is in [atm] and the binary diffusion coefficient is in [cm2/s]. the values for ( )∑ kiv are given by fuller et al. [12]. the temperature field is obtained by solving the convective energy equation: ( )( ) 0=∇−⋅∇ tktcpr ggggg uρ (7) the gas phase and the liquid phase are assumed to be in thermodynamic equilibrium; hence the temperature of the liquid water is the same as the gas phase temperature. 2) gas diffusion layers (gdl) the physics of multiple phases through a porous medium is further complicated here with phase change and the sources and sinks associated with the electrochemical reaction. the equations used to describe transport in the gdl are given below. mass transfer in the form of evaporation ( )0>phasem and condensation ( )0<phasem is assumed, so that the mass balance equations for both phases are: ( )( ) phasegg msat =−⋅∇ uερ1 (8) ( ) phasell msat =⋅∇ uερ. (9) the momentum equation for the gas phase reduces to darcy’s law, which is based on the relative permeability for the gas phase. the relative permeability accounts for the reduction in pore space available for one phase due to the existence of the second phase [7]. the momentum equation for the gas phase inside the gdl becomes: ( ) pkpsat g g ∇−−= µ 1u (10) two liquid water transport mechanisms are considered; shear, which drags the liquid phase along with the gas phase in the direction of the pressure gradient, and capillary forces, which drive liquid water from high to low saturation regions [7]. therefore, the momentum equation for the liquid phase inside the gdl becomes: sat sat pkp p kp c l l l l l ∇∂ ∂ +∇−= µµ u (11) the functional variation of capillary pressure with saturation is prescribed following leverett [7] who has shown that: 𝑃𝑐 = 𝜏 � 𝜀 𝐾𝑃 � 1 2⁄ (1.417(1 − 𝑠𝑎𝑡) − 2.121−𝑠𝑎𝑡2+1.2631−𝑠𝑎𝑡3 (12) the liquid phase consists of pure water, while the gas phase has multi components. the transport of each species in the gas phase is governed by a general convection-diffusion equation in conjunction which the stefanmaxwell equations to account for multi species diffusion: ( ) ( ) ( ) phase t igig n j jjjj j ijig m t t dysat p p yx m m yy m m dysat =             ∇ +⋅− +∑       ∇ −+      ∇ +∇−− ⋅∇ = εερ ερ u1 1 1 (13) in order to account for geometric constraints of the porous media, the diffusivities are corrected using the bruggemann correction formula [3]: m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 10 5.1ε×= ij eff ij dd (14) the heat transfer in the gas diffusion layers is governed by the energy equation as follows: ( )( )( ) ( ) evapphasesolid geffggg hmtt tktcpsat ∆−− =∇−−⋅∇ εεβ εερ ,1 u (15) where the term ( ( )ttsolid −εβ ), on the right hand side, accounts for the heat exchange to and from the solid matrix of the gdl. β is a modified heat transfer coefficient that accounts for the convective heat transfer in [w/m2] and the specific surface area [m2/m3] of the porous medium [3]. hence, the unit of β is [w/m3]. the gas phase and the liquid phase are assumed to be in thermodynamic equilibrium, i.e., the liquid water and the gas phase are at the same temperature. the potential distribution in the gdls is governed by: ( ) 0=∇⋅∇ φλe (16) in order to determine the magnitude of phase change inside the gdl, expressions are required to relate the level of overand undersaturation as well as the amount of liquid water present to the amount of water undergoing phase change. in the present work, the procedure of djilali [7] was used to determine the magnitude of phase change inside the gdl. 3) catalyst layers (cls) the catalyst layer is treated as a thin interface, where sink and source terms for the reactants are implemented. due to the infinitesimal thickness, the source terms are implemented in the last grid cell of the porous medium. the sink terms for oxygen and hydrogen are given by: c o o if m s 4 2 2 −= ; a h h if m s 2 2 2 −= (17) the production of water is modelled as a source terms, and hence can be written as: c oh oh if m s 2 2 2 = (18) the generation of heat in the cell is due to entropy changes as well as irreversibilities due to the activation overpotential [13]: ( ) ccact e i fn st q ,       + ∆− = η (19) the local current density in the cls is modelled by the butler-volmer equation [14, 15];             −+                = cact c cact a ref o oref coc rt f rt f c c ii ,,, expexp 2 2 η α η α (20)             −+                = aact c aact a ref h href aoa rt f rt f c c ii ,, 21 , expexp 2 2 η α η α (21) 4) membrane the balance between the electro-osmotic drag of water from anode to cathode and back diffusion from cathode to anode yields the net water flux through the membrane: ( )wwohdw cdf i mnn ∇⋅∇−= ρ 2 (22) the water diffusivity in the polymer can be calculated as follow [6]:             −×= − t dw 1 303 1 2416exp103.1 10 (23) the variable wc represents the number of water molecules per sulfonic acid group (i.e. mol h2o/equivalent so3 -1). the water content in the electrolyte phase is related to water vapour activity via [8, 9]: ( ) ( ) ( ) ( )3 8.16 31 14.10.14 10 0.3685.3981.17043.0 32 ≥= ≤<−+= ≤<+−+= ac aac aaaac w w w (24) the water vapour activity given by: sat w p px a = (25) for heat transfer purposes, the membrane is considered a conducting solid, which means that the transfer of energy associated with the net water flux through the membrane is neglected. heat transfer in the membrane is determined by: ( ) 0=∇⋅⋅∇ tkmem (26) the potential loss in the membrane is due to resistance to proton transport across membrane, and determined by: ( ) 0=∇⋅∇ φλm (27) 5) cell potential electrical energy is obtained only when a current is drawn, but the actual cell potential (ecell) is decreased from its equilibrium thermodynamic potential (e) because of irreversible losses. the cell potential is obtained by subtracting all over potentials (losses) from m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 11 the equilibrium thermodynamic potential as the following expression [16, 17]: diffmemohmactcell ee ηηηη −−−−= (28) the equilibrium potential is determined using the nernst equation [18]: 𝐸 = 1.229 − 0.83𝑥10−3(𝑇 − 298.15) + 4.3085𝑥10−5𝑇�𝑙𝑛�𝑃𝐻2� + 1 2 𝑙𝑛�𝑃𝑂2�� (29) the anode and cathode activation overpotentials are calculated from butler-volmer equation. the ohmic overpotentials in gdls and protonic overpotential in membrane are calculated from the potential equations, respectively. the anode and cathode diffusion overpotentials are calculated as follows:         −= cl c cdiff i i f rt , , 1ln2 η ;         −= al a adiff i i f rt , , 1ln2 η (30) gdl oo cl cfd i δ 22 2 , = ; gdl hh al cfd i δ 22 2 , = (31) c. hygro-thermal stresses in fuel cell as a result of the changes in temperature and moisture, all the pem, gdl, and bipolar plates will experience expansion and contraction. because of the different thermal expansion and swelling coefficients between these materials, hygro-thermal stresses are expected to be introduced. in addition, the non-uniform current and reactant flow distributions in the cell can result in non-uniform temperature and moisture content of the cell, which could in turn, potentially causing localized increases in the stress magnitudes. using hygrothermo elasticity theory, the effects of temperature and moisture as well as the mechanical forces on the behavior of elastic bodies have been addressed. an uncoupled theory is assumed, for which the additional temperature changes brought by the strain are neglected. the total strain tensor is determined using the following expression [11]: stm ππππ ++= (32) where mπ is the contribution from the mechanical forces and ,t sπ π are the thermal and swelling induced strains, respectively. the thermal strains resulting from a change in temperature of an unconstrained isotropic volume are given by: ( )ft tt re−℘=π (33) the swelling strains caused by moisture change in membrane are given by: ( )fmems reℜ−ℜ= π (34) assuming linear response within the elastic region, the isotropic hooke's law is used to determine the stress tensor: πσ g= (35) where g is the constitutive matrix. the effective stresses according to von mises, 'mises stresses', are given by: ( ) ( ) ( ) 2 2 13 2 32 2 21 σσσσσσσ −+−+− =v (36) where 1σ , 2σ , 3σ are the principal stresses. d. boundary conditions in order to reduce computational cost, the advantage of the geometric periodicity of the cell is taken. hence symmetry is assumed in the ydirection, i.e. all gradients in the y-direction are set to zero at the x-z plane boundaries of the domain. with the exception the channel inlets and outlets, a zero flux condition is applied at all x-boundaries (y-z planes). the inlet values at the anode and cathode are prescribed for the velocity, temperature, and species concentrations (dirichlet boundary conditions). the gas streams entering the cell are fully humidified, but no liquid water is contained in the gas stream. the inlet velocities of air and fuel are calculated based on the desired current density according to: chinc cin ino meaccin ap rt x a f i u 11 4 , , , , 2 ζ= (37) china ain inh meaaain ap rt x a f i u 11 2 , , , , 2 ζ= (38) at the outlets of the gas-flow channels, only the pressure is being prescribed as the desired electrode pressure, for all other variables, the gradient in the flow direction (x) is assumed to be zero (neumann boundary conditions). at the external surfaces in the z-direction, (top and bottom surfaces of the cell), temperature is specified and zero heat flux is applied at the x-y plane of the conducting boundary surfaces. combinations of dirichlet and neumann boundary conditions are used to solve the electronic and protonic potential equations. dirichlet boundary conditions are applied at the m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 12 land area. neumann boundary conditions are applied at the interface between the gas channels and the gdls to give zero potential flux into the gas channels. similarly, the protonic potential field requires a set of potential boundary condition and zero flux boundary condition at the anode cl interface and cathode cl interface respectively. the mechanical boundary conditions are noted in figure 1. the initial conditions corresponding to zero stress-state are defined, all components of the cell stack are set to reference temperature 20°c, and relative humidity 35% [11, 19]. in addition, a constant pressure of 1 mpa is applied on the surface of lower plate, corresponding to a case where the stack is clamped with springs to control the force. iii. solution algorithm the governing equations were discretized using a finite volume method and solved using a general-purpose computational fluid dynamic (cfd) code. stringent numerical tests were performed to ensure that the solutions were independent of the grid size. a computational mesh of 150,000 computational cells was found to provide sufficient spatial resolution. figure 2 shows flow diagram of the solution algorithm used in this study. it begins by specifying a desired current density of the cell for calculating inlet flow rates at the anode and cathode sides. an initial guess of the activation over potential is obtained from the desired current density using the butler-volmer equation, then follows by computing the flow fields for each phase for velocities u, v, w, and pressure p. once the flow field is obtained, the mass fraction equations are solved for oxygen, hydrogen, nitrogen, and water. scalar equations are solved last in the sequence of the transport equations for the temperature field in the cell and potential fields in the gdls and the membrane. hooke's law with total strain tensor is solved to determine the stress tensor. the local current densities are solved based on the butler-volmer equation, then local activation over potentials can be calculated from the butler-volmer equation. they are updated after each global iterative loop. convergence criteria are performed on each variable and the procedure is repeated until convergence. the properties are updated after each global iterative loop based on the new local gas composition and temperature. source terms reflect changes in the overall gas phase mass flow due to consumption or production of gas species via reaction and due to mass transfer between water in the vapor phase and water that is in the liquid phase or dissolved in the polymer. the set of equations was solved iteratively, and the solution was considered to be convergent when the relative error in each field between two consecutive iterations was less than 10-6. the number of iterations required to obtain converged solutions dependent on the nominal current density of the cell, the higher the load the slower the convergence. figure 2. flow diagram of the solution procedure used figure 3. effect of liquid water build up on cell performance m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 13 iv. results and discussion the values of the electrochemical transport parameters for the base case operating conditions are listed in table 1. the geometric and the base case operating conditions are listed in table 2. since this model accounts for all major transport processes and the domain comprises all the elements of a complete cell, no parameters needed to be adjusted. performance curves with and without phase change as well as experimental data are shown in figure 3 for the base case conditions. the experimental data is provided by wang et al. [14]. comparison of the two curves demonstrates that the model represents better cell potential (v) versus current density (a/cm2) curve than single phase model. the effects of liquid water accumulation become apparent even at relatively low values of current density. this result validated the developed model. results with phase change for the cell operates at nominal current density of 1.4 a/cm2 under the base operating conditions are analyzed and table 1. electrode and membrane parameters for base case operating conditions parameter [ref.] symbol value unit electrode porosity [16] ε 0.4 electrode electronic conductivity [5] eλ 100 ms / membrane ionic conductivity (humidified nafion117) [16] mλ 17.1223 ms / transfer coefficient, anode side [17] aα 0.5 transfer coefficient, cathode side [15] cα 1 cathode reference exchange current density [3] refcoi , 1.81e-3 2/ ma anode reference exchange current density [3] refaoi , 2465.6 2/ ma electrode thermal conductivity [4] effk 1.3 kmw ./ membrane thermal conductivity [4] memk 0.455 kmw ./ electrode hydraulic permeability [14] kp 1.76e-11 2m entropy change of cathode side reaction [13] s∆ -326.36 kmolej ./ heat transfer coefficient between solid and gas phase [3] β 4e6 3/ mw protonic diffusion coefficient [16] +hd 4.5e-9 sm /2 fixed-charge concentration [16] fc 1200 3/ mmole fixed-site charge [16] fz -1 electro-osmotic drag coefficient [18] dn 2.5 droplet diameter [7] dropd 1e-8 m condensation constant [7] c 1e-5 scaling parameter for evaporation [7] ϖ 0.01 electrode poisson's ratio gdlℑ 0.25 membrane poisson's ratio [11] memℑ 0.25 electrode thermal expansion [11] gdl℘ -0.8e-6 k1 membrane thermal expansion [19] mem℘ 123e-6 k1 electrode young's modulus [11] gdlψ 1e10 pa membrane young's modulus [19] memψ 249e6 pa electrode density [11] gdlρ 400 3mkg membrane density [19] memρ 2000 3mkg membrane humidity swelling-expansion tensor [11] mem 23e-4 %1 m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 14 discussed in this section. the selection of relatively high current density is due to illustrate the phase change effects, where it becomes apparent between single and multi-phase model in the mass transport limited region. the velocity fields inside the gdls are shown in figures 4 and 5. the liquid water saturation inside the gdl are shown in figure 6, and the profile of water content in the membrane is shown in figure 7. these results are newly disclosed here and they have not been presented in the previous papers [20-24]. from figure 4 and 5 it is clear that the pressure gradient induces bulk gas flow from the channels into the gdl while the capillary pressure gradient drives the liquid water out of the gdl into the flow channels. the velocity of the liquid phase is lower than the gas phase, and the highest liquid water velocity occurs at the corners of the channel/gdl interface. the liquid water oozes out of the gdl, mainly at the corners of the gdl/channel interface. from figure 6 it can be observed that condensation occurs mainly in two areas inside the cathodic gdl i.e. at the catalyst layer the molar water vapour fraction increases due to the oxygen depletion, and at the channel/gdl interface, where the oversaturated bulk flow condenses out. condensation occurs throughout table 2. parameters for base case conditions parameter symbol value unit channel length l 0.05 m channel width w 1e-3 m channel height h 1e-3 m land area width landw 1e-3 m gdl thickness gdlδ 0.26e-3 m membrane thickness (nafion 117) mem δ 0.23e-3 m catalyst thickness clδ 0.028e3 m h2 reference mole fraction ref hx 2 0.84639 o2 reference mole fraction ref ox 2 0.17774 anode pressure ap 3 atm cathode pressure cp 3 atm inlet fuel and air temperature cellt 353.15 k relative humidity of inlet fuel and air ψ 100 % air stoichiometric flow ratio cξ 2 fuel stoichiometric flow ratio aξ 2 (a) (b) figure 4. velocity vectors inside the cathode gdl: (a) gas phase velocity vectors; (b) liquid water velocity vectors (a) (b) figure 5. velocity vectors inside the anode gdl: (a) gas phase velocity vectors; (b) liquid water velocity vectors m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 15 the anodic gdl due to hydrogen depletion. similar to the cathode side, the liquid water can only leave the gdl through the build-up of a capillary pressure gradient to overcome the viscous drag, because at steady state operation, all the condensed water has to leave the cell. the liquid water saturation is distributed through the entire gdl with maximum saturations found under the land areas. the high spatial variation of the saturation demonstrates again the three-dimensional nature of transport processes in pemfc. clearly, liquid water saturation depends strongly on the specified figure 6. liquid water saturation inside the gdls figure 7. water content profile through the mea figure 8. water vapour molar fraction distribution in the cell at a nominal current density of 1.4 a/cm2 m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 16 capillary pressure, and the permeability of the gdl becomes the central parameter. in the membrane, primary transport is through electroosmotic drag associated with the protonic current in the electrolyte, which results in water transport from anode to cathode, and diffusion associated with water-content gradients in the membrane. from figure 7 it can be noticed that the influence of electro-osmotic drag and back diffusion are apparent. water vapour molar fraction distribution is shown in figure 8. it remains almost constant throughout the gdl. in the absence of phase change, this would not be the case, as the nitrogen and water vapour fraction would increase as the oxygen fraction decreases. reactant gas distribution in the cell cannels and the gdls demonstrate similar distribution with those under operation at current density of 0.8 a/cm2 [24]. they are not plotted in this paper. the molar fraction of oxygen is highest under the channel, and exhibits a three-dimensional behavior with a fairly significant drop under the land areas, and a more gradual depletion towards the outlet. the molar hydrogen fraction is almost constant inside the gdl due to the higher diffusivity of the hydrogen. the local current density distribution is shown in figure 9. this result resembles the result reported earlier when the fuel cell was operated at nominal density current of 1.2 a/cm2 under temperature of 60°c and 90°c [20]. the differences exist at its magnitude. the maximum value in this study is 1.5 while that in the previous study was 1.4. the local current densities have been normalized by divided through the nominal current density (i.e. iic ). in the model it has a much higher fraction of the total current, generated under the channel area. this is due to the effects of liquid water inside the gdl which decreases its permeability to reactant gas flow and lead to the onset of pore plugging by liquid water. this can lead to local hot-spots inside the membrane electrode assembly. this leads to a further drying out of the membrane and increasing the electric resistance, figure 9. dimensionless local current density distribution ( iic ) at the cathode side catalyst layer figure 10. temperature distribution inside the fuel cell m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 17 which in turn leads to more heat generation and can lead to a failure of the membrane. it is important to keep the current density relatively even throughout the cell. therefore, the model is capable of identifying important parameters for the wetting behavior of the gdls and can be used to identify conditions that might lead to the onset of pore plugging. the temperature distribution inside the cell has important effects on nearly all transport phenomena, and knowledge of the magnitude of temperature increases might help preventing failure. figure 10 shows temperature distribution throughout the x-axis inside the cell at a nominal current density of 1.4 a/cm2. temperature distribution only on the y-z plane at x=10 mm has been published earlier [23]. from figure 10 it can be observed that the increase in temperature can exceed several degrees kelvin near the inlet area, where the electrochemical activity is highest. the temperature peak appears in the cathode cl. in general, the temperature at the cathode side is higher than at the anode side, this is due to the reversible and irreversible entropy production. figure 11 shows von mises stress distribution inside the membrane during the cell operating at base case conditions and a nominal current density of 1.4 a/cm2. the similar distribution has been published when the cell was operated at nominal density current of 1.2 a/cm2 [21]. compared to the previous results figure 11 shows larger stresses. the maximum stress occurs, where the temperature is highest, which is near the cathode side inlet area. the membrane-electrode-assembly (mea) is the core component of pemfc and consists of membrane with the gdls including the catalyst attached to each side. von misses stress distribution (contours plots) in the cell on the y-z plane at x=10 mm at nominal current density of 1.4 a/cm2 has been published [23]. in this paper the close up of the same distribution is plotted in figure 12 (scale enlarged 300 times). because of the different thermal expansion and swelling coefficients between gdls and membrane materials, hygro-thermal stresses and deformation are introduced. it induces bending stresses which can contribute to delaminating between the membrane and the gdls. the distribution of total displacement and deformed shape for mea at base conditions on the y-z plane at x=10 mm are similar to those at nominal current density of 1.2 a/cm2 [21]. however, the magnitude is different. at nominal current density of 1.4 a/cm2 larger displacement can be seen. it is related to the temperature where the temperature is highest in the centre of the channel and coincide with the highest reactant concentrations. the deformation under the land areas is much smaller than under the channel areas due to the clamping force effect. this result may explain the occurrence of cracks and pin holes in the membrane under steady–state loading during regular cell operation. fuel cell losses originate from sources such as activation overpotential, ohmic overpotential in gdl, membrane overpotential, and diffusion overpotential. when the cell operates at nominal current density of 0.8 a/cm2 all of these losses have been published [24]. here, only activation losses are plotted in figure 13. table 3 shows comparison of the maximum values of these losses (in volt) between the two cases of figure 11. mises stresses distribution inside the membrane table 3. comparison of maximum losses source of losses current density: 0.8 (a/cm2) current density: 1.4 (a/cm2) activation 0.398 (volt) 0.387 (volt) ohmic 0.060 (volt) 0.086 (volt) membrane 0.180 (volt) 0.250 (volt) diffusion 0.065 (volt) 0.040 (volt) m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 18 operating nominal current density. the activation overpotential loss profile at the cathode side cl correlates with the local current density. the current densities are highest in the centre of the channel and coincide with the highest reactant concentrations. it can be seen that the loss is directly related to the nature of the electrochemical reactions. the reaction propagates at the rate demanded by the current. v. conclusion the developed model has been validated by comparing its results to experimental data. it has been proved that the model represents better cell potential (v) versus current density (a/cm2) curve than single phase model. in the cathodic and anodic gdls, the velocity of the liquid phase is lower than the gas phase, and the highest liquid water velocity occur at the corners of the channel/gdl interface. the liquid water saturation is distributed through the entire gdl with maximum saturations found under the land areas. the molar water vapour fraction remains almost constant throughout the gdl. the molar fraction of oxygen is highest under the channel, and exhibits a three-dimensional behavior with a fairly significant drop under the land areas, and a more gradual depletion towards the outlet. the molar hydrogen fraction is almost constant inside the gdl due to the higher diffusivity of the hydrogen. the model has been used to analysis important variables at nominal current density of 1.4 a/cm2. when compared to previous results at nominal current density of 1.2 a/cm2, the results in this paper shows larger local current density, larger von mises stresses, and larger displacement. when compared to previous results at nominal current density of 0.8 a/cm2, the results in this paper show smaller activation losses, larger ohmic losses, larger membrane losses, and smaller diffusion losses. the model is shown to be able to: (1) understand complex phenomena which cannot be studied experimentally, (2) identify limiting steps and components, and (3) provide a computer-aided tool for design and optimization of pemfc with much higher power density and lower cost. references [1] e. e. kahveci and i. taymaz, "experimental investigation on water and heat management in a pem fuel cell using response surface methodolog," figure 12. von misses stress distribution in mea figure 13. activation overpotential loss distribution m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 19 international journal of hydrogen energy, 39(20), pp. 10655-10663, 2014. [2] a. p. sasmito et al., "numerical evaluation of various thermal management strategies for polymer electrolyte fuel cell stacks," international journal of hydrogen energy, 36, pp. 12991-13007, 2011. [3] h. meng, "numerical studies of liquid water behaviors in pem fuel cell cathode considering transport across different porous layer," international journal of hydrogen energy, 35(11), pp. 5569–5579, 2010. [4] n. k. h. dalasm et al., "a parametric study of cathode catalyst layer structural parameters on the performance of a pem fuel cell," international journal of hydrogen energy, 35(6), pp. 2417–2427, 2010. [5] s. w. perng, and h. w. wu, "nonisothermal transport phenomenon and cell performance of a cathodic pem fuel cell with a baffle plate in a tapered channel," applied energy, 88(1), pp. 52–67, 2011. [6] a. iranzo et al., "numerical model for the performance prediction of a pem fuel cell. model results and experimental validation," international journal of hydrogen energy, 35(20), pp. 11533– 11550, 2010. [7] n. djilali, "computational modelling of pem fuel cells: challenges and possibilities," energy, 32(4), pp. 269-280, 2007. [8] m. hu et al., “three dimensional, two phase flow mathematical model for pem fuel cell. part i. model development,” energy conversion manag, 45(11-12): 1861–1882, 2004. [9] c. fink, and n. fouquet, "threedimensional simulation of polymer electrolyte membrane fuel cells with experimental validation," electrochimica acta, 56(28), pp. 10820–10831, 2011. [10] a. webber, and j. newman, “theoretical study of membrane constraint in polymer-electrolyte fuel cell,” aiche j., 50(12), 3215–3226, 2004. [11] d. bograchev et al., "stress and plastic deformation of mea in running fuel cell," international journal of hydrogen energy, 33, pp. 5703–5717, 2008. [12] m. a. r. s. al-baghdadi, "performance comparison between planar and tubularshaped ambient air-breathing pem fuel cells using three-dimensional computational fluid dynamics models," journal of renewable and sustainable energy; 1(2), pp. 023105-1-023105-15, 2009. [13] m. a. r. s. al-baghdadi, "a cfd analysis of transport phenomena and electrochemical reactions in a tubularshaped ambient air-breathing pem micro fuel cell," the hong kong institution of engineers transactions (hkie transactions), 17(2), pp. 1-8, 2010. [14] m. a. r. s. al-baghdadi, “pem fuel cells from single cell to stack,” international energy and environment foundation (ieef), 2015, isbn-13: 9781505885644. [15] m. a. r. s. al-baghdadi. "novel design of a compacted micro-structured airbreathing pem fuel cell as a power source for mobile phones," international journal of energy and environment; 1(4), pp. 555-572, 2010. [16] m. a. r. s. al-baghdadi, "analysis of transport phenomena and electrochemical reactions in a micro pem fuel cell," international journal of energy and environment, 5(1), pp. 1-22, 2014. [17] m. a. r. s. al-baghdadi, "analysis of transport phenomena and electrochemical reactions in a micro pem fuel cell with serpentine gas flow channels," international journal of energy and environment, 5(2), pp. 139-154, 2014. [18] m. a. r. s. al-baghdadi, "analysis of transport phenomena and electrochemical reactions in a micro pem fuel cell with nature inspired flow field design," international journal of energy and environment; 6(1), pp. 1-16, 2015. [19] product information, dupont™ nafion® pfsa membranes n115, n117, n1110 perfluorosulfonic acid polymer. nae101, 2016. [20] m. a. r. s. al-baghdadi, and haroun a.k.s. al-janabi, "parametric and optimization styudy of a pem fuel cell performance using three-dimensional computational fluid dynamics model," renewable energy (2007), pp. 1077-1101, 32. [21] m. a. r. s. al-baghdadi, and haroun a.k.s. al-janabi, "effect of operating parameters on the hydro-thermal stresses in proton exchange membrane of fuel cells," international journal of hydrogen energy, 32, pp. 4510-4522, 2007. m.a.r.s. al-baghdadi / j. mechatron. electr. power veh. technol 07 (2016) 7-20 20 [22] m. a. r. s. al-baghdadi, and h. a. k. s. al-janabi, "modeling optimizes pem fuel cell performance using threedimensional multi-phase computational fluid dynamics model," energy conversion and management, 48, pp. 3102-3119, 2007. [23] m. a. r. s. al-baghdadi, "a cfd study of hygro-thermal stresses distribution in pem fuel cell during regular cell operation," renewable energy, 34, pp. 674-682, 2009. [24] m. a. r. s. al-baghdadi, "performance comparison between air flow-channel and ambient air-breathing pem fuel cells using three-dimensional computation fluid dynamics models," renewable energy, 34, pp. 1812-1824, 2009. nomenclature a water activity meaa geometrical area of mea (m 2) cha cross sectional area of flow channel (m 2) c local concentration (mole/m3) refc reference concentration (mole/m3) cp specific heat capacity (j/kg.k) d diffusion coefficient (m2/s) e equilibrium thermodynamic potential (v) celle cell operation potential (v) f faraday’s constant = 96487 (c/mole) i cell operating current density (a/m2) i local current density (a/m2) ref oi , reference exchange current density effk effective electrode thermal conductivity (w/m.k) memk membrane thermal conductivity (w/m.k) kp hydraulic permeability (m2) phasem mass transfer kg/s) m molecular weight (kg/mole) wn net water flux across the membrane (kg/m 2.s) nd electro-osmotic drag coefficient en number of electrons transfer p pressure (pa) cp capillary pressure (pa) q heat generation (w/m2) r universal gas constant = 8.314 (j/mole.k) s specific entropy (j/mole.k) sat saturation t temperature (k) u velocity vector (m/s) ix mole fraction iy mass fraction aα charge transfer coefficient, anode side cα charge transfer coefficient, cathode side ε porosity η over potential (v) eλ electrode electronic conductivity (s/m) mλ membrane ionic conductivity (s/m) µ viscosity (kg/m.s) ρ density (kg/m3) τ surface tension (n/m) ξ stoichiometric flow ratio σ stress (n/m) π strain ℜ relative humidity (%) i. introduction ii. model description a. computational domain b. model equations 1) gas flow channels 2) gas diffusion layers (gdl) 3) catalyst layers (cls) 4) membrane 5) cell potential c. hygro-thermal stresses in fuel cell d. boundary conditions iii. solution algorithm iv. results and discussion v. conclusion references nomenclature microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 5 survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam ridwan arief subekti pusat penelitian tenaga listrik dan mekatronik lipi komp lipi bandung, jl. sangkuriang, gd. 20. lt. 2, bandung, jawa barat 40135, indonesia ridwanarief_rais@yahoo.com diterima: 25 juni 2010; direvisi: 30 agustus 2010; disetujui: 29 september 2010; terbit online: 10 oktober 2010. abstrak generator set adalah salah satu alat yang dapat menghasilkan listrik. generator set digunakan bila pasokan listrik pln tidak mencukupi atau bahkan tidak ada. hal inilah yang dialami di wilayah kuta malaka kabupaten aceh besar nad yang rencananya akan dikembangkan menjadi objek wisata. karena belum tersedianya pasokan listrik dari pln, maka untuk menunjang kebutuhan listriknya masih menggunakan generator set. rencananya kawasan wisata tersebut akan memanfaatkan pembangkit listrik tenaga air sebagai sumber pasokan energi listrik. dari latar belakang tersebut di atas, maka survey potensi air dilakukan dengan tujuan untuk mendapatkan data dan informasi awal potensi tenaga air sebagai dasar dalam perencanaan dan pembangunan pltmh. survey potensi ini meliputi penentuan lokasi dan pengukuran head menggunakan global positioning system merek garmin tipe gpsmap 76csx. selain menggunakan altimeter, pengukuran beda ketinggian juga dilakukan secara manual menggunakan meteran dengan metode spirit level and string. pengukuran debit air sungai dilakukan dengan mengukur kecepatan arus sungai menggunakan propeller devices atau current meters merek flowatch. dari data survey potensi pltmh di daerah kuta malaka tersebut dapat diketahui bahwa terdapat tiga lokasi yang memiliki potensi untuk dikembangkan sebagai lokasi pltmh dengan head efektif 5 sampai 16 meter dan daya keluaran 3,7 sampai 9,1 kw. kata kunci : energi air, mikro hidro, pembangkit listrik, survey potensi, turbin air. abstract generator set is one of the devices able to produces electrics. generator set used when electrics supply of pln insufficient or even there no. this matter experienced in kuta malaka, aceh besar, nanggroe aceh darussalam there will be developed a tour area. because electrical supply from pln not yet, power electric to support the area used generator set. future, that tour area apply hydro power station for electrical energy requirement. from that background, the purpose of water potential survey was conducted to get beginning data and information of water power potential as reference to develop pltmh. the potential survey cover determination of location and head measurement use global positioning system garmin gpsmap 76csx. the other using altimeter, head also was measure manually used the meter by spirit level and string method. the river rate of flow measurement within measuring to speed of rivers flow use propeller devices or current meters brand flowatch. from data of pltmh potential survey in kuta malaka area known that there are three potential locations able to be developed as pltmh with effective head 5 until 16 meter and output power 3.7 until 9.1 kw. keyword: water energy, micro hydro, power station, potential survey, water turbine. i. pendahuluan a. latar belakang listrik merupakan salah satu kebutuhan yang sangat penting bagi kehidupan manusia. tanpa adanya listrik, akan sulit bagi kita untuk mengembangkan suatu aktivitas. salah satu contohnya terdapat di wilayah kawasan hutan lindung kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam. di areal hutan lindung seluas kurang lebih 2000 hektar ini, rencananya akan dikembangkan menjadi daerah objek wisata alam. saat ini di daerah hutan lindung kuta malaka telah dibangun perkebunan buah naga, stroberi, pisang, pohon jati dan lain-lain. selain itu terdapat pula kolam ikan serta peternakan ayam dan sapi. bangunan kafe dan kantor administrasi juga sedang dilaksanakan pembangunannya. rencana kedepan, di areal kawasan hutan lindung kuta malaka tersebut juga akan dibangun sarana outbound, kolam pemancingan dan sarana-sarana rekreasi lainnya [1]. survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam (ridwan arief subekti) pp. 5-12 6 namun demikian, karena belum tersedianya pasokan listrik dari pln, maka objek wisata alam tersebut mengalami beberapa hambatan dalam pembangunannya. aktivitas perkebunan, peternakan dan objek wisata lainnya akan sulit berkembang tanpa adanya pasokan listrik yang memadai walaupun saat ini seluruh operasional kebutuhan listrik di daerah tersebut masih disuplai oleh generator set. dengan berkembangnya objek wisata tersebut maka kebutuhan akan energi listrik juga akan terus berkembang sehingga pemakaian generator set yang saat ini digunakan untuk mensuplai listrik menjadi tidak efisien dan boros. untuk itu, rencananya kawasan wisata di areal hutan lindung kuta malaka akan memanfaatkan pembangkit listrik ramah lingkungan yaitu pembangkit listrik tenaga mikro hidro (pltmh) sebagai sumber pasokan energi listriknya. selain digunakan untuk beberapa tempat objek wisata, listrik yang dihasilkan oleh pembangkit listrik tenaga mikro hidro ini juga akan digunakan sebagai penerangan jalan menuju lokasi objek wisata tersebut. sumber air untuk pembangkit listrik tenaga mikro hidro akan memanfaatkan aliran sungai yang terdapat di kawasan hutan lindung kuta malaka yang mana menurut penduduk sekitar dan pengelola kawasan tersebut selama ini debit air sungai yang mengalir di kuta malaka relatif stabil sepanjang tahun. dari latar belakang tersebut di atas, diperlukan suatu survey potensi sungai di daerah kawasan hutan lindung kuta malaka sehingga dapat digunakan sebagai sumber energi pada pembangkit listrik tenaga mikro hidro secara optimal. pltmh adalah suatu pembangkit listrik tenaga air dengan kapasitas sistem maksimal 120 kw. hal ini mengadopsi standar kualitas dari india dan nepal serta mempertimbangkan kemampuan produksi di dalam negeri [2]. pembangkit listrik tenaga air adalah suatu bentuk perubahan tenaga dari tenaga air dengan ketinggian dan debit tertentu menjadi tenaga listrik, dengan menggunakan turbin air dan generator [3]. b. tujuan tujuan makalah ini adalah memberikan gambaran dan informasi awal mengenai potensi tenaga air sebagai dasar dalam perencanaan dan pembangunan pembangkit listrik tenaga mikro hidro (pltmh). dalam makalah ini akan dijabarkan mengenai lokasi-lokasi yang potensial untuk dikembangkan sebagai pembangkit listrik tenaga mikro hidro, potensi daya, spesifikasi turbin, generator, sistem kontrol dan beban serta dimensi pipa penstok dan bangunan sipilnya. ii. metode survey survey potensi pembangkit listrik tenaga mikro hidro ini dilaksanakan di daerah pegunungan kuta malaka, kabupaten aceh besar propinsi nanggroe aceh darussalam dengan koordinat 5,2° 5,8° lu dan 9,50° 95,8° bt. lokasi tersebut seperti yang terlihat pada gambar 1 di bawah ini yang berasal dari peta program garmin map source. gambar 1. peta lokasi survey potensi pembangkit listrik tenaga mikro hidro. lokasi survey puncak kuta malaka banda aceh bandara udara journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 7 survey potensi air sebagai dasar dalam perencanaan dan pembangunan pembangkit listrik tenaga mikro hidro (pltmh) ini dilakukan dalam empat tahapan metode seperti dibawah ini: a. penentuan lokasi b. pengukuran tinggi jatuh air c. pengukuran debit air d. perhitungan potensi daya terbangkitkan. selanjutnya metode survey tersebut akan dijabarkan lebih detail seperti yang terdapat di bawah ini. a. penentuan lokasi penentuan lokasi dilakukan dengan menyusuri sungai yang berada di daerah kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam. survey lapangan dilakukan guna mengetahui lokasi-lokasi mana yang berpotensi untuk dilaksanakan pembangunan pembangkit listrik tenaga mikro hidro (pltmh). setelah didapat lokasi yang memiliki potensi, dilakukan penandaan lokasi menggunakan gps seperti gambar 2 di bawah ini. gambar 2. penandaan lokasi menggunakan gps tipe gps yang digunakan adalah gpsmap76csx merek garmin. pada saat pertama kali kita menghidupkan gps, receiver gps secara otomatis akan mengumpulkan data satelit dan arah lokasinya. untuk memastikan pengenalan yang tepat, gpsmap76csx telah dilengkapi dengan mode pencari jejak otomatis. mode tersebut menunjukkan lokasi gps di mana saja di seluruh dunia. untuk menerima sinyal satelit kita harus berada di luar ruangan dan pemandangan langit yang jelas. waypoint (titik tuju) adalah adalah lokasi yang kita rekam dan simpan di dalam gps. untuk merekam jalur saluran pembawa dari bendungan ke bak penampungan dan jalur pipa penstock dari bak penampungan ke rumah turbin, kita dapat memanfaatkan fitur tracks yang terdapat pada gps. fitur tracks menciptakan jejak remah-remah elektronik atau “catatan jejak” pada map page selama bepergian. catatan jejak tersebut berisi informasi tentang poin-poin sepanjang jalurnya, termasuk waktu, lokasi, ketinggian, dan kedalaman. catatan jejak segera mulai merekam semua informasi yang diperlukan sesaat setelah alat ini menentukan posisi lokasi yang dikirimkan oleh minimal dua sinyal satelit [4]. b. pengukuran tinggi jatuh air pengukuran tinggi jatuh air antara sumber air dengan lokasi turbin dilakukan menggunakan altimeter yang terdapat pada gps. prinsip kerja altimeter adalah mengukur tekanan udara. tekanan udara akan berubah 9 mm head air raksa untuk setiap 100 meter perubahan elevasi. altimeter sangat mudah terpengaruh oleh perubahan suhu, tekanan atmosfir dan kelembaban. penggunaan altimeter yang terbaik adalah dengan melakukan pengukuran beda ketinggian dalam jangka waktu yang secepatnya. secara umum pengukuran menggunakan altimeter adalah pengukuran yang paling baik terutama untuk pengukuran kondisi-kondisi tertentu misalnya untuk pengukuran head yang tinggi. altimeter page pada gps menunjukkan peningkatan yang sedang berlaku, rata-rata penurunan/pendakian, profil perubahan peningkatan ketinggian sepanjang jarak dan waktu, atau profil perubahan tekanan sepanjang waktu. gpsmap76csx ini juga bergantung pada tekanan barometric pada saat menentukan ketinggian dan tekanan pada setiap ketinggian dapat berubah-ubah. pengukuran ketinggian juga dilakukan dengan metode pengukuran lainnya sebagai pembanding. untuk itu, selain menggunakan altimeter, pengukuran beda ketinggian juga dilakukan secara manual menggunakan meteran dengan menggunakan metode spirit level and string (papan water pass). metode ini hampir sama dengan pengukuran beda ketinggian menggunakan selang water pass namun perbedaanya adalah pada metode spirit level and string menggunakan batang water pass. metode spirit level and string melakukan pengukuran beda ketinggian antara dua titik dengan menggunakan bantuan tiang, tali, dan batang water pass untuk melihat kelurusannya secara horizontal [5]. pengukuran head secara manual menggunakan meteran ditunjukkan pada gambar 3 berikut ini. survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam (ridwan arief subekti) pp. 5-12 8 gambar 3. pengukuran head menggunakan meteran. c. pengukuran debit air pengukuran debit air sesaat di lokasi memilik tiga tujuan yaitu : a. untuk mengetahui debit air sepanjang musim kemarau dimana studi hidrologi dilakukan guna mengetahui debit air terkecil b. untuk memverifikasi data yang diperoleh dari dokumen pengairan apakah sesuai dengan data yang diperoleh dari pengukuran c. diperlukan dalam aplikasi dari metode korelasi aliran. pengukuran debit air dilakukan menggunakan alat propeller devices atau sering juga disebut current meters seperti yang terlihat pada gambar 4 di bawah ini. gambar 4. pengukuran kecepatan aliran air. propeller devices atau current meters adalah sebuah batang dengan propeller atau balingbaling yang dapat bergerak bebas berputar dan dihubungkan dengan layar monitor menggunakan kabel untuk membaca kecepatan aliran air. biasanya alat ini mengukur kecepatan air mulai dari 0,2 sampai 5 m/s dengan tingkat kepresisian 2 %. setelah kecepatan arus air diketahui selanjutnya dilakukan pengukuran luas penampang melintang sungai. dari dua parameter tersebut, debit air dapat dihitung dengan persamaan berikut. . (1) dimana: q = debit air [m3/s] v = kecepatan air [m/s] a = luas penampang melintang sungai [m2][6] pengukuran kecepatan aliran air yang mengalir di sungai dilakukan menggunakan alat current meters merek flowatch. propeller yang digunakan berdiameter 60 mm yang dapat mengukur kecepatan air dari 0,2 m/s sampai dengan 14 m/s dengan tingkat kepresisian ± 2 % dan off-axis error = ± 20 % sampai ±3 % [7]. d. perhitungan potensi daya terbangkitkan data hasil survey potensi air diolah untuk mengetahui besarnya daya yang dapat dibangkitkan dengan menggunakan persamaan (2) berikut. . . . (2) dimana: p = daya terbangkitkan (watt) ρ = massa jenis air = 1000 kg/m3 g = gravitasi = 9,81 m2/s q = debit (m3/s) heff = tinggi efektif (m) [8] iii. hasil survey pada kegiatan survey potensi air ini, penentuan lokasi dilakukan dengan mempertimbangkan bebarapa hal seperti letak lokasi yang dekat dengan jalan dan jarak antara lokasi dengan beban (konsumen) sehingga tidak dilakukan penyusuran seluruh aliran sungai. selain itu juga didapat masukan dari masyarakat sekitar mengenai adanya potensi tenaga air berupa terjunan pada aliran sungai tersebut. dari hasil survey potensi air dapat diketahui bahwa lokasi yang potensial untuk dibangun pltmh memiliki head efektif 5 dan 16 meter. namun demikian sebenarnya terdapat beberapa lokasi lainnya yang dapat dimanfaatkan untuk membangkitkan listrik yaitu dengan menggunakan turbin head sangat rendah dimana head yang ada sekitar ± 1 meter. pada survey potensi energi air ini dapat ditentukan tiga lokasi yang memiliki potensi untuk dikembangkan sebagai pembangkit listrik tenaga mikro hidro seperti disebut dibawah ini. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 9 a. lokasi kesatu – taeyeun lokasi turbin kesatu terletak didaerah taeyeun dengan ketinggian 112 mdpl. lokasi pertama ini berada pada koordinat 5,40559° lu dan 95,37636° bt. dilokasi taeyeun ini, head effektif yang dapat dimanfaatkan adalah 5 meter dengan debit terukur 0,23 m3/s sehingga potensi daya hidrolis yang dimiliki adalah 9,81 kw. lokasi rumah turbin, bak pemampungan dan bendungan dapat dilihat pada gambar 5. gambar 5. posisi turbin, bak penampungan dan saluran pembawa lokasi kesatu. b. lokasi kedua – kolam pemancingan lokasi turbin kedua yang terletak di dekat kolam pemancingan diantara bangunan kafe dan lokasi turbin kesatu memiliki ketinggian 177 meter diatas permukaan laut. lokasi ini berada pada koordinat 5,39894° lu dan 95,37096° bt. dilokasi kedua atau dekat kolam pemancingan ini, head efektif yang dapat dimanfaatkan sama dengan lokasi kesatu yaitu 5 meter namun lokasi kedua ini memiliki debit terukur yang lebih kecil yaitu 0,144 m3/s sehingga potensi daya hidrolis yang dimiliki juga lebih kecil bila dibandingkan dengan lokasi kesatu. potensi daya hidrolis yang dimiliki oleh lokasi kedua ini adalah 6,38 kw. lokasi turbin kedua dapat dilihat pada gambar 6 di bawah ini. gambar 6. lokasi turbin kedua. rumah turbin 1 bak penampungan bendungan lokasi turbin 1 lokasi turbin 2 bangunan cafe survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam (ridwan arief subekti) pp. 5-12 10 c. lokasi ketiga penyeberangan terakhir lokasi turbin ketiga berada pada koordinat 5,38602° lu dan 95,36496° bt. lokasi ini terletak di dekat penyebrangan terakhir dengan ketinggian 465 meter diatas permukaan laut. dibandingkan dengan dua lokasi sebelumnya, lokasi ketiga ini memiliki head paling tinggi yaitu 16 meter. namun demikian, lokasi ketiga ini memiliki debit air terukur yang paling kecil yaitu 0,11 m3/s. dengan debit terukur sebesar itu, lokasi ini mempunyai potensi daya yang dapat dibangkitkan sebesar 15,7 kw. lokasi turbin ketiga dapat dilihat seperti pada gambar 7 di bawah ini. gambar 7. lokasi air terjun dan rumah turbin ketiga. selanjutnya data survey potensi air dan spesifikasi pembangkit listrik tenaga mikro hidro (pltmh) seperti head, debit, dan besarnya potensi daya yang dapat terbangkitkan untuk setiap lokasi dibuat dalam bentuk tabel seperti pada tabel 1 dan tabel 2 dibawah ini. tabel 1. potensi daya, dimensi penstock dan saluran pada lokasi 1, 2 dan 3. no uraian & simbol keterangan lokasi satuan 1 2 3 1 head efektif (heff) 5,0 5,0 16 meter 2 debit terukur (qm) 0,23 0,144 0,11 m 3/s 3 debit desain (qd) 0,2 0,130 0,10 m 3/s 4 potensi daya hidrolis (ph) . . . /1000 9,81 6,38 15,7 kw 5 estimasi effisiensi turbin (ητ ) 80 80 80 % 6 estimasi effisiensi total (ηtotal) 58 58 58 % 7 estimasi daya listrik di rumah pembangkit (p) . . . . /1000 5,7 3,7 9,1 kw 8 diameter penstock (ø) kecepatan (v) = 1 m/s 0,5 0,4 0,4 m 9 panjang penstock (l) pengukuran 30 30 36 m 10 panjang saluran pembawa l: 0,7 m dan t: 0,75 m 130 10 10 m 11 panjang bendungan pengukuran 10 10 10 m 12 bak penampung p: 9,2 ; l: 3,5 ; t: 3,5 m 1 1 1 ls 13 saluran pelimpah l: 0,7 m dan t: 0,75 m 1 1 1 ls 14 pintu air l: 0,7 m dan t: 0,75 m 3 3 3 pcs air terjun 2 air terjun 1 lintasan sungai lokasi turbin 3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 11 tabel 2. spesifikasi turbin, generator, sistem kontrol dan ballast load lokasi 1, 2 dan 3. lokasi 1 2 3 turbin tipe propeller propeller cross flow diameter runner 125 mm 110 mm 100 mm panjang 991 mm 859 mm 280 mm head 5 m 5 m 16 m debit air optimum 200 liter/detik 130 liter/detik 100 liter/detik daya poros 7,85 kw 5,1 kw 12,56 kw putaran turbin 150 160 rpm 150 160 rpm 1500 rpm efisiensi 80 % 80 % 80 % generator jenis syncronous generator syncronous generator syncronous generator rating power 10 kva 7.5 kva 20 kva frekuensi 50 hz 50 hz 50 hz avr standar standar standar phase/pole 3 3 3 putaran poros 1500 rpm 1500 rpm 1500 rpm tegangan 380/220 volt 380/220 volt 380/220 volt power factor 0.8 0,8 0,8 efisiensi 0,85 0,85 0,85 sistem kontrol tipe elc (electronic load controller) elc (electronic load controller) elc (electronic load controller) rating power 10 kw 10 kw 15 kw tegangan 220/380 v 220/380 v 220/380 v ballast load tipe air heater air heater air heater rating power 12 kw 12 kw 15 kw iv. kesimpulan dan saran a. kesimpulan dari hasil survey awal yang telah dilakukan di daerah pegunungan kuta malaka, kabupaten aceh besar propinsi nanggroe aceh darussalam, dapat diambil beberapa kesimpulan sebagai berikut: 1. aliran sungai di kawasan pengunungan kuta malaka dapat dimanfaatkan sebagai sumber energi untuk pembangunan pembangkit listrik tenaga mikro hidro, baik itu untuk head yang tinggi maupun untuk head yang rendah. 2. dari hasil perhitungan diperoleh besarnya daya yang mampu dibangkitkan oleh masingmasing pembangkit listrik tenaga mikro hidro adalah berbeda disetiap lokasi tergantung head, debit air dan jenis turbin yang digunakan. hasil perhitungan pada setiap lokasi adalah sebagai berikut. a. lokasi 1 : daya terbangkitkan 5,7 kw dengan head 5 m, debit 0,2 m3/s, jenis turbin propeller b. lokasi 2 : daya terbangkitkan 3,7 kw dengan head 5 m, debit 0,13 m3/s, jenis turbin propeller c. lokasi 3 : daya terbangkitkan 9,1 kw dengan head 16 m, debit 0,1 m3/s, jenis turbin cross flow. b. saran 1. potensi mikro hidro masih dapat dieksplorasi lebih banyak lagi melalui survey lanjutan terutama memanfaatkan potensi head rendah. 2. perlunya survey lanjutan sebagai dasar informasi yang lebih akurat guna menyusun studi kelayakan sebelum dilakukannya pembangunan pltmh. survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam (ridwan arief subekti) pp. 5-12 12 ucapan terima kasih terima kasih kami ucapkan kepada bapak anjar susatyo selaku mantan kepala bidang elektronika daya dan mesin listrik, pusat penelitian tenaga listrik dan mekatronik – lembaga ilmu pengetahuan indonesia. terima kasih juga kepada jon kanidi, ibu pudji, dodiek, pak emin selaku rekan survey dan bapak wawan dari pt. buana wahana energi. terima kasih kepada mas priyo dan jainudin atas masukannya. terima kasih juga kami ucapkan kepada warga kuta malaka, aceh besar nanggroe aceh darussalam yang telah membantu dalam peraksanaan survey potensi pembangkit listrik tenaga mikro hidro ini. daftar pustaka [1] ____., “laporan survey potensi energi kawasan pegunungan kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam”, (2009), pt. buana wahana energi, bandung. [2] kusdiana, d., sitompul, a. dkk., “pedoman teknis standardisasi peralatan dan komponen pembangkit listrik tenaga mikro hidro (pltmh) imidap (integrated microhydro development and application program)”, (2008), direktorat jenderal listrik dan pemanfaatan energi departemen energi dan sumber daya mineral, jakarta. [3] arismunandar, a. dan kuwahara, s., “buku pegangan teknik tenaga listrik – jilid i pembangkitan dengan tenaga air”, (1974), pradnya paramita, jakarta. [4] ____., “manual book gpsmap 76csx”, (2006), garmin international ltd, kansas, usa. [5] harvey, adam., “micro hydro design manual – a guide to small scale water power schemes”, (1993), itdg publishing, london,uk. [6] streeter, v. l. dan benyamin, e. wylie., “mekanika fluida”, edisi delapan, jilid 1, (1986), erlangga, jakarta [7] ____., “instruction manual of flowatch”, (2006), jdc electronics sa, switzerland. [8] dietzel, f. dan sriyono, d., “turbin pompa dan kompresor”, (1990), erlangga, jakarta. journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.11-21 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. optimization of smes and tcsc using particle swarm optimization for oscillation mitigation in a multi machines power system dwi lastomo a,*, herlambang setiadi b, muhammad ruswandi djalal c a upmb institut teknologi sepuluh nopember upmb building jl raya its, surabaya 60117, indoneisa b school of information technology & electrical engineering the university of queensland level 4 / general purpose south building (buliding 78) st. lucia campus, brisbane, australia c department of mechanical engineering ujung pandang state polytechnics jl. perintis kemerdekaan 7 km. 10, makassar, indonesia received 28 february 2017; received in revised form 18 may 2017; accepted 22 may 2017 published online 31 july 2017 abstract due to the uncertainty of load demand, the stability of power system becomes more insecure. small signal stability or lowfrequency oscillation is one of stability issues which correspond to power transmission between interconnected power systems. to enhance the small signal stability, an additional controller such as energy storage and flexible ac transmission system (facts) devices become inevitable. this paper investigates the application of superconducting magnetic energy storage (smes) and thyristor controlled series compensator (tcsc) to mitigate oscillation in a power system. to get the best parameter values of smes and tcsc, particle swarm optimization (pso) is used. the performance of the power system equipped with smes and tcsc was analyzed through time domain simulations. three machines (whose power ratings are 71.641, 163, and 85 mw) nine buses power system was used for simulation. from the simulation results, it is concluded that smes and tcsc can mitigate oscillatory condition on the power system especially in lowering the maximum overshoot up to 0.005 pu in this case. it was also approved that pso can be used to obtain the optimal parameter of smes and tcsc. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: power system oscillation; facts; smes; tcsc; pso i. introduction electrical energy is one of the important requirements for modern society. in recent years, demand for electricity has increased significantly. due to increasing of load demand, providers of electricity need to expand their transmission system and increase the generating capacity. moreover, the entire system becomes more complex and larger. stability is one of the common problems in a large system, especially when perturbation occurs. small perturbation such as load fluctuation could contribute to system instability, such as low-frequency oscillation. the low-frequency oscillation has a frequency range of approximately 0.1-2 hz focusing in electromechanical mode either local or global problems [1]. if this oscillation is not well damped, the magnitude of this oscillation may keep growing until the system loses synchronism [2]. this oscillation can be decreased by putting damper windings in the rotor. however, over the times, the performance can be declined significantly. another way is by using flexible ac transmission system (facts) devices. however, due to the uncertainty of the load, facts devices alone cannot address the low-frequency oscillation problems. hence, the deployment of energy storage has become crucial. in this era, there is numerous type of energy storage such as flywheel energy storage [3], battery energy storage [4], redox flow batteries [5], capacitive energy storage [6] and superconducting magnetic energy storage [7]. superconducting magnetic energy storage (smes) is the energy storage that is gaining popularity in recent year because of fast response * corresponding author. tel: +62 856 2981 144 e-mail address: dtomo23@gmail.com https://dx.doi.org/10.14203/j.mev.2017.v8.11-21 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.11-21 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.11-21&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 12 when storing and releasing energy. the most important part of smes is the controller. to obtained the best controller parameter of smes, metaheuristic algorithm approach can be the solution. metaheuristic algorithm is an algorithm inspired by nature behavior. metaheuristic algorithm can be classified into 3 types. namely, social inspired, physical inspired, and biological inspired [2]. particle swarm optimization (pso) is metaheuristic algorithm based on the biologically inspired algorithm. pso is widely used due to simple modeling and fast calculation to solve optimization problems. the application of pso for optimizing facts devices has been proposed by shahgholian et all. [8]. in that research, facts based pso has shown good performance for providing damping to the system when installed in the transmission line. wei et all. made use of the smes to mitigate oscillatory condition of multi-machines power system [9]. it can be seen in the research that smes gives an attractive performance for providing damping by storing and releasing energy from the grid. application of pso for optimization method in power system has also been conducted by kerdphol et all [10]. it can be stated that pso shows marvelous performance to find the optimal capacity of battery energy storage in microgrid system. these researchers showed a good performance of facts devices and smes to enhance small signal stability by mitigating the oscillatory condition of the power system. these researches also showed that pso could provide fast calculation, simple modeling and accurate result for optimization problems. however, very scant attention has been paid for combining and coordinating facts devices and smes to mitigate power system oscillation. thus, this research novelty is combining two different devices which are facts devices (tcsc) and energy storage (smes) for small signal stability enhancement. the tcsc might improve the stability in the transmission line, while the energy storage (smes) could contribute damping by providing active power instantaneously into the grid. furthermore, this research also contributes on how to coordinate between the facts devices (tcsc) and energy storage (smes) using one of the intelligent methods called pso to mitigate oscillatory condition on power system due to load fluctuation. the rest of this paper is organized as follows: section ii briefly explain about power system modeling, smes dynamic model, and tcsc mathematical representation. pso concept including the objective function of proposed method and modeling the entire system are described in section iii. section iv shows the time domain simulation results of the studied case. section v presents the conclusion. ii. fundamental theory a. power system modelling for small signal stability study, power system model can be presented as a set of differential and algebraic equations as in equations (1) and (2) [11]. �̇� = 𝑓(𝑥, 𝑦, 𝑙, 𝑝) (1) 0 = 𝑔(𝑥, 𝑦, 𝑙, 𝑝) (2) where x is a state vector and y is a vector of algebraic variables. dynamic stability studies can be done in two ways depending on the interest [11]. if the interest is to understand dynamic characteristic in the local behavior related to the particular plant, the single machine infinite bus (smib) can be used as study cases. if the interest is capturing both local and global problem, then every machine in the system should be modeled in detail [11]. 1) synchronous generator model assuming that the value of stator resistance is ignored, the condition is considered the balanced system, the core saturation on the generator is ignored, and the system load is considered being static. the well known park’s transformation [12] serves to transform current, voltage, and flux density into variables in three axes, namely direct axis, quadrature axis and stationary axis. clear depiction of the park’s transformation can be seen in figure 1. the synchronous generator comprises of torque equation and field equation. the relationship between rotor angle and rotor speed can be written in a set of a differential equation as in equations (3) and (4). �̇�𝑖 = 𝜔𝑖 − 𝜔𝐵 (3) �̇�𝑖 = 1 𝑀𝑖 [𝑇𝑚𝑖 − 𝑇𝑒𝑖 − 𝐷𝑖 (𝜔𝑖 − 𝜔𝐵 )](4) (4) where 𝑇𝑚𝑖 , 𝑇𝑒𝑖 , 𝐷𝑖 , 𝜔𝐵 , and 𝑀𝑖 are mechanical torque, electric torque, the damping constant, base speed, and machine inertia. equations (5) and (6) can express field equations. �̇�𝑞𝑖 ′ = 1 𝑇𝑑𝑜𝑖 ′ [𝐸𝑓𝑑𝑖 − 𝑇𝑞𝑖 ′ − (𝑥𝑑𝑖 − 𝑥𝑑𝑖 ′ )𝑖𝑑𝑖 ] (5) �̇�𝑑𝑖 ′ = 1 𝑇𝑞𝑜𝑖 ′ [−𝐸𝑓𝑑𝑖 − (𝑥𝑞𝑖 − 𝑥𝑞𝑖 ′ )𝑖𝑑𝑖 ] (6) where 𝑇𝑑𝑜𝑖 ′ , 𝑇𝑞𝑜𝑖 ′ , 𝑥𝑑𝑖 , 𝑥𝑑𝑖 ′ , 𝑥𝑞𝑖 , and 𝑥𝑞𝑖 ′ are the transient time constant in d axis, the transient time constant in q axis, reactance in d axis, transient reactance in d axis, reactance in q axis and transient reactance in q axis respectively. d axis q axis a axis b axis c axis  qi qi di fi di fi bi ci ai sa sc sb fb fc fa 'n 'n 'n figure 1. park’s transformation [12] d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 13 2) excitation system the synchronous generator consists of a stator with windings anchor and rotor with field windings. rotor field windings must be injected with a direct current (dc) to generate a magnetic field. this particular system is called excitation system. fast exciter model is used in this study. fast exciter excitation is the simplest model consisting of one 𝐾𝐴𝑖 gain and 𝑇𝐴𝑖 time constant expressed in equation (7) [13]. 𝐸𝑓𝑑 = 𝐾𝐴(𝑉𝑡−𝑉𝑟𝑒𝑓) 1−𝑇𝐴𝑆 (7) where 𝐾𝐴𝑖 is gain and 𝑇𝐴𝑖 is the time delay of the exciter [13]. figure 2 shows the fast exciter block diagram. 3) governor model a governor is to regulate the magnitude of mechanical torque provided to the generator. variation of mechanical torque in the governor is influenced by speed, load, and speed reference variation. the mathematical representation of governor model is shown in equation (8) [14]. 𝑃𝑚 = − [ 𝐾𝑔 1+𝑇𝑔𝑠 ] 𝜔𝑑 (8) where 𝐾𝑔, 𝑇𝑔, and r are gain constant, the time delay of the governor and droop constant respectively. the gain constant and the droop relationship is inversely proportional. figure 3 depicts the block diagram of the governor. b. superconducting magnetic energy storage smes is a device for storing and releasing the power in large number simultaneously. smes saves energy in a magnetic field created by dc current in superconducting coils, and it is cooled by a cryogenic. smes system has been used for a few years to improve the power quality industry and provide good voltage control when voltage fluctuation arises. smes recharging can be done just a couple minute and can repeat the charge and discharge modes thousands time without reducing the magnet. recharging time can be accelerated to meet specific criteria depending on the capacity of the system [15]. smes was first introduced by ferier in 1969, the man who first proposed the construction of a toroidal coil capable of supplying the daily storage of electrical energy across france [15]. however, the manufacturing cost was too expensive, so the idea was not met. in 1971 researchers at the university of wisconsin the us began to explore the basic relationship between the energy storage unit to the electrical system passing multiphase bridge [15, 16]. smes comprise of a superconducting inductor (smes coil), cryogenic cooling system, and a power conditioning system (pcs) with controller and protection systems [15]. smes in the power system used to effectively control the balance of power on the synchronous generator during periods of dynamic. smes can be installed at a terminal bus of the power system. figure 4 depicts the basic configuration of smes consisting of a transformer, voltage sources converter, dc to dc chopper and superconducting coil. dc-dc converter and chopper are linked by a dc link capacitor [2, 15, 17]. the mathematical representation of smes unit can be expressed using equations (9) and (10). ∆ed = 1 1+stdc [𝑘0∆𝜔1 − 𝑘𝐼𝑑 ∆𝐼𝑑 ] (9) ∆𝐼𝑑 = 1 𝐿𝑠 ∆𝐸𝑑 (10) refv st k a a 1 tv fde maxrv minrv figure 2. fast exciter block diagram 1 1 tgs kg d  gsc m t figure 3. governor block diagram dc link capacitor y/ transformer voltage source converter dc-dc chopper dc current bypass switch smes coils from terminal generator figure 4. schematic diagram of smes [17] d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 14 where 𝑇𝑑𝑐 is the converter time delay, ∆𝐼𝑑 is the current flowing through the inductor, ∆𝐸𝑑 is dc voltage applied to the inductor, 𝑘0 is gain constant, l is the inductance of the coil, 𝑘𝐼𝑑 is the feedback gain, and ∆𝜔1 is rotor speed oscillatory in generator 1 [2, 18]. equation (11) expresses the deviation in the inductor real power of smes [2, 18]. ∆𝑃𝑠𝑚𝑒𝑠 (𝑡) = ∆𝐼𝑑0∆𝐸𝑑 + ∆𝐼𝑑 ∆𝐸𝑑 (11) where ∆𝑃𝑠𝑚𝑒𝑠 is the real power that is released to the grid. figure 5 shows the block diagram of smes. c. thyristor controlled series compensator flexible ac transmission systems (facts) are becoming inevitable devices in transmission lines. facts devices provide parameter compensation in a transmission line to control the power flow. this device can control the magnitude of the voltage, line impedance, phase angle at the end of the channel and increase the security of the system. thyristor controlled series compensator (tcsc) is one of facts devices that has become popular in recent years. tcsc is used for controlling transmission line reactance to provide load compensation [19]. tcsc consists of capacitor parallel connected with inductor and thyristor controlled reactor as depicted in figure 6 [19]. in power flow study, tcsc can modify the transmission line. tcsc value level is a function of the reactance of the transmission line at the tcsc location. moreover, tcsc can also be used as an oscillation damping controller. tcsc can be modeled as a variable reactance for the small signal stability study. the mathematical representation of tcsc can be described as in equation (12). �̇�𝑡𝑐𝑠𝑐 = 1 𝑇𝑡𝑐𝑠𝑐 〈𝐾𝑡𝑐𝑠𝑐 (𝑋𝑡𝑐𝑠𝑐 𝑟𝑒𝑓 + 𝑈𝑡𝑐𝑠𝑐 ) − 𝑋𝑡𝑐𝑠𝑐 〉 (12) iii. design smes and tcsc using particle swarm optimization in this section, a dynamical model of the overall system is derived, and a brief explanation of particle swarm optimization (pso) is described. at the end of this section, the objective function is presented based on the derived overall dynamical model. this objective function will be solved using pso. a. power system model of overall system based on equations (3) to (12), power system model in equations (1) and (2) of the overall system can be expressed in figures 7-9. figure 7 shows the representation of the entire test system with tcsc installed in the transmission line. figure 8 depicts a simulink model of tcsc while figure 9 illustrates a dynamic representation of power plant with exciter and governor. furthermore, figure 10 illustrates a dynamic model of a synchronous generator with smes. all of the systems is expressed in linear model representation. the parameters that will be optimized are gain constant of the smes and parameters of the lead-lag block in the tcsc. b. particle swarm optimization particle swarm optimization (pso) is an evolutionary computation optimization technique developed by kennedy and eberhart [20, 21, 22]. the system initially has a population of random solutions. each potential solution is called a particle. each particle is given a random velocity and is flown through the problem space. the particles have memory, and each particle keeps track of its previous best position (called the pbest) and its corresponding fitness. there exist a number of pbest for the respective particles in the swarm, and the particle with the greatest fitness is called the global best (gbest) of the swarm. the basic concept of the pso technique lies in accelerating each particle towards its pbest and gbest locations, with a random weighted acceleration at each time step. the main steps in the particle swarm optimization and selection process are described as 0 k 1 1 dc st idk     smes p 1 sl d i 0d i 0d d i i  d e d e 1  figure 5. block diagram of smes [2, 18] figure 6. schematic diagram of tcsc [19] d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 15 follows: (a) initialize a population of particles with random positions and velocities in d dimensions of the problem space and fly them; (b) evaluate the fitness of each particle in the swarm; (c) for every iteration, compare each particle’s fitness with its previous best fitness (pbest) obtained. if the current value is better than pbest, then set pbest equal to the current value and the pbest location equal to the current location in the d-dimensional space; (d) compare pbest of particles with each other and update the swarm global best location with the greatest fitness (gbest); (e) change the velocity and position of the particle according to equations (13) and (14) respectively; 𝑉𝑖𝑑 = 𝜔 × 𝑉𝑖𝑑 + 𝐶1 × 𝑟𝑎𝑛𝑑1(𝑃𝑖𝑑 − 𝑋𝑖𝑑 ) + 𝐶2 × 𝑟𝑎𝑛𝑑2 × (𝑃𝑔𝑑 − 𝑋𝑖𝑑 ) (13) 𝑋𝑖𝑑 = 𝑋𝑖𝑑 + 𝑉𝑖𝑑 (14) (14) (f) in this stage, repeat step procedure (a) to (e) until convergence is reached based on some desired single or multiple criteria. c. objective function and optimization method the objective function for pso can be determined using equation (15). 𝐸 = ∑ ∫ 𝑡|∆𝜔(𝑡, 𝑋)|𝑑𝑡 𝑡1 0 (15) where ∆𝜔(𝑡, 𝑋) is the oscillatory condition of generator rotor speed., x is composed by kid of the smes, and parameters t1, t2, t3, t4 of the tcsc, while t1 is the time frame of the simulation. kid in smes represents the feedback gain, while t1-t4 correspond to the lead-lag block of tcsc. in this research, the objective function is to minimize the value of e. moreover the constraints of the problem are the smes and the tcsc optimized parameter. figure 7. simulink model of the test system figure 8. simulink model of tcsc d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 16 figure 9. simulink model of the power plant figure 10. simulink model of synchronous machine and smes d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 17 start evaluating the objective function of individual i updating the pbest and gbest updating the possition of individual i, x k+1 termination criterion satisfied? updating the velocity of individual i, v k+1 end initializing the system parameters initializing the individual position randomly initializing the individual velocity randomly yes no result/output figure 11. flowchart of optimization procedure table 1. power specification of the generators sna loads [23, 24] bus generating (mw) generating (mwar) load (mw) load (mwar) 1 71.641 27.046 0 0 2 163 654 0 0 3 85 -10.860 0 0 4 0 0 0 0 5 0 0 125 50 6 0 0 90 30 7 0 0 0 0 8 0 0 100 35 9 0 0 0 0 table 2. the specification of bus resistance and reactance [23, 24] bus r (pu) x (pu) 1-4 0 0.0576 2-7 0 0.0625 3-9 0 0.0586 4-5 0.01 0.085 4-6 0.017 0.092 5-7 0.032 0.161 6-9 0.039 0.170 7-8 0.0085 0.075 8-9 0.0119 0.1008 table 3. parameter values of the generators [23, 24] plant xd xd’ td0’ xq xq’ tq0’ 1 0.146 0.061 8.96 0.097 0.097 0.31 2 0.896 0.12 6 0.865 0.197 0.535 3 1.313 0.181 5.89 1.2 0.25 0.6 table 4. parameter values of the exciters [2, 24] plant h ka ta 1 23.64 20 0.2 2 6.40 20 0.2 3 3.01 20 0.2 figure 11 shows the flowchart of the optimization algorithm used in this paper. the algorithm starts by initializing the multi-machine systems, smes, tcsc and pso parameters. next, initialize the position and velocity of the particle by making a random matrix with particular constraint. evaluation the objective function is done by finding the minimum error of the objective function. the next step is to update the local and global best of the particle. then updating the velocity and the position of the particle is conducted. if the criterion is satisfied, then the algorithm will be stopped. if not, then the process will go back to initializing velocity of the particle. the iteration will stop depending on how many numbers of iteration is chosen. iv. result and discussion an electrical power system shown in figure 12 is investigated. it consists of 9 bus and 3 machines in which a smes is installed in generator 1 bus and tcscs are installed in lines between bus 5 and bus 7. the case study was simulated under matlab/simulink environment in 50 seconds. in the simulation parameter setting, a continuous state with ode45 dormand-prince solver was set. pso was used to optimize the parameter of smes and tcsc. tables 1 and 2 [23, 24] show the power specification of the generators and loads and the specification of the bus resistance and reactance. tables 3 and 4 list up the parameter values of generators and the exciters, respectively. the tcsc and smes parameters values are listed in table 5. d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 18 table 5. parameter values of the tcsc and smes [2, 24] parameter value parameter value ttcsc 15 xmax 0.7 α 158 xmin 0 xtcsc 0.3591 σ 80 t1 0.4 ido 4.5 t2 0.1 l 2.5 t3 0.3 ko 5 t4 0.1 kid 60 tw 10 tdc 0.05 ktcsc 0.38 table 6. optimum parameters values obtained using pso parameter value t1 0.8296 t2 0.0987 t3 0.3935 t4 0.0999 kid 89.608 table 7. eigenvalue of three different cases (simulations 1, 2, 3) tscs smes tcsc smes tcsc pso -0.0667+0.0000i -0.0667+0.000i -0.0667+0.0000i -10.0000+0.0000i -10.000+0.000i -10.0100+0.0000i -10.0000+0.0000i -10.000+0.000i -10.1317+ 0.0000i -0.1000+0.0000i -0.100+0.0000i -0.1000+0.0000i -9.2770+0.0000i -10.004+7.405i -10.016+10.5567i -5.2446+0.0000i -10.004-7.4053i -10.0155-10.5567i -3.1314+3.6219i -9.275+0.0000i -9.2757+0.0000i -3.1314-3.6219i -5.266+0.0000i -5.2632+0.0000i -2.4967+2.5493i -3.132+3.6222i -3.1316+3.6221i -2.4967-2.5493i -3.133-3.6222i -3.1316-3.6221i -2.5680+2.2782i -2.500+2.5556i -2.5011+2.5551i -2.5680-2.2782i -2.500-2.5556i -2.5011-2.5551i -0.4115+0.5351i -2.569+2.2787i -2.5687+2.2786i -0.4115-0.5351i -2.569-2.2787i -2.5687-2.2786i -0.4680+0.4572i -0.925+0.0000i -0.9493+0.0000i -0.4680-0.4572i -0.457+0.4755i -0.4569+0.4754i -0.0596+0.0000i -0.457-0.4755i -0.4569-0.4754i -0.1440+0.0000i -0.244+0.3941i -0.2439+0.3941i -0.3208+0.0000i -0.244-0.3941i -0.2439-0.3941i -0.2462+0.3966i -0.094+0.1621i -0.0692+0.1398i -0.2462-0.3966i -0.094-0.1621i -0.0692-0.1398i -3.1546+0.0000i -0.163+0.0000i -0.0611+0.0000i -0.061+0.0000i -0.1667+0.0000i -3.155+0.0000i -3.1546+0.0000i figure 13 shows convergence curves of the fitness function during iteration of pso. it is clear that after 10 iterations, the pso found its convergence value. the optimum parameters values obtained through the iteration are listed in table 6. to investigate the effect of the application of pso to the performance of the power system equipped with smes and tcsc, three simulations have been conducted those are a simulation with tcsc (simulation 1), simulation with tcsc and smes (simulation 2), and simulation with tcsc and smes optimized by pso (simulation 3). the operating condition in this case study is the initial condition of the multi-machine using newton-rapson method as power flow calculation. the newton-rapson method used 100 mva and 0,001 as base power and smes system bus 1 bus 4 bus 6bus 5 bus 7 bus 8 bus 9bus 2 bus 3 gen 1 gen 2 gen 3 load 3 load 2 load 1 tcsc figure 12. schematic diagram of the three machines nine buses electrical power system with tcsc and smes [23] d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 19 table 8. overshoot and settling time (generator 1) parameter tcsc tcsc smes tcsc smes pso overshoot (pu) -0.1293 -0.09347 -0.08875 settling time (sec) >100 >100 >100 table 9. overshoot and settling time (generator 2) parameter tcsc tcsc smes tcsc smes pso overshoot (pu) -0.08789 -0.08558 -0.08522 settling time (sec) >100 >100 >100 table 10. overshoot and settling time (generator 3) parameter tcsc tcsc smes tcsc smes pso overshoot (pu) -0.0444 -0.03817 -0.03771 settling time (sec) >100 >100 >100 accuration while 50 and 230 kv were chosen as maximum iteration and base voltage. figure 14 shows eigenvalue trajectories of simulation 1, simulation 2, and simulation 3. it can be seen that smes and tcsc provide better performance in term of larger eigenvalues in the left half plane. table 7 lists up those eigenvalues. time domain simulation was carried out to validate the eigenvalue trajectories. to observe the response, small load perturbation addressed in generator 1 by giving 0.05 step input. the oscillatory condition of rotor speed from generator, 1, 2 and 3 was shown in figures 15-17. it was monitored that by installing smes and tcsc to the system, the dynamic response of the system is enhanced which is indicated by less overshoot during small perturbation. it happened because of smes gives active power, and tcsc gives load compensated to the system, so the stress of the generator was decreased. it was also noticeable that the best response is a system with smes and tcsc optimized by pso. tables 8 shows the overshoot and settling time of generator, 1, 2 and 3. figure 13. convergence curve of pso algorithm figure 14. eigenvalue trajectories (simulation 1, simulation 2, simulation 3) table 8. overshoot and settling time generator parameter tcsc tcsc smes tcsc smes pso generator 1 overshoot (pu) -0.1293 -0.09347 -0.08875 settling time (sec) >100 >100 >100 generator 2 overshoot (pu) -0.08789 -0.08558 -0.08522 settling time (sec) >100 >100 >100 generator 3 overshoot (pu) -0.0444 -0.03817 -0.03771 settling time (sec) >100 >100 >100 d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 20 figure 15. rotor speed oscillatory condition of g1 figure 16. rotor speed oscillatory condition of g2 figure 17. rotor speed oscillatory condition of g3 d. lastomo et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 11–21 21 v. conclusion this paper investigates the impact of utilizing smes and tcsc for mitigating low-frequency oscillation in a multi machines power system of which their parameters values are optimized using pso. from the case studies carried out through computer simulation, it is found that a combination of smes and tcsc whose parameter values are optimized using pso provide better performance in term of smaller overshoot and smaller settling time. acknowledgement the authors are very grateful to the anonymous reviewers for the comment and suggestion to enhance the quality of this research. references [1] a. u. krismanto et al., "microgrid impact on low frequency oscillation and resonance in power system," in 2016 ieee innovative smart grid technologies asia (isgt-asia), 2016, pp. 424-429. [2] h. setiadi and k. o. jones, "power system design using firefly algorithm for dynamic stability enhancement," indonesian journal of electrical engineering and computer science, vol. 1, no. 3, pp. 446-455, 2016. [3] h. h. abdeltawab and y. a.-r. i. mohamed, "robust energy management of a hybrid wind and flywheel energy storage system considering flywheel power losses minimization and grid-code constraints," ieee transactions on industrial electronics, vol. 63, no. 7, pp. 4242-4254, 2016. [4] d. q. hung et al., "integration of pv and bes units in commercial distribution systems considering energy loss and voltage stability," applied energy, vol. 113, pp. 1162-1170, 2014. [5] r. shankar et al., "impact of energy storage system on load frequency control for diverse sources of interconnected power system in deregulated power environment," international journal of electrical power & energy systems, vol. 79, pp. 11-26, 7// 2016. [6] n. v. kumar and m. m. t. ansari, "a new design of dual mode type-ii fuzzy logic load frequency controller for interconnected power systems with parallel ac–dc tie-lines and capacitor energy storage unit," international journal of electrical power & energy systems, vol. 82, pp. 579-598, 2016. [7] m. g. molina and p. e. mercado, "power flow stabilization and control of microgrid with wind generation by superconducting magnetic energy storage," ieee transactions on power electronics, vol. 26, no. 3, pp. 910922, 2011. [8] g. shahgholian and a. movahedi, "power system stabiliser and flexible alternating current transmission systems controller coordinated design using adaptive velocity update relaxation particle swarm optimisation algorithm in multi-machine power system," iet generation, transmission & distribution, vol. 10, no. 8, pp. 1860-1868, 2016. [9] w. yao et al., "adaptive power oscillation damping controller of superconducting magnetic energy storage device for interarea oscillations in power system," international journal of electrical power & energy systems, vol. 78, pp. 555-562, 2016. [10] t. kerdphol et al., "optimization of a battery energy storage system using particle swarm optimization for stand-alone microgrids," international journal of electrical power & energy systems, vol. 81, pp. 32-39, 2016. [11] k. prasertwong et al., "understanding low-frequency oscillation in power systems," international journal of electrical engineering education, vol. 47, no. 3, pp. 248-262, 2010. [12] p. m. anderson and a. a. fouad, power system control and stability. john wiley & sons, 2008. [13] j. machowski et al., power system dynamics: stability and control. john wiley & sons, 2011. [14] m. r. djalal et al., "optimal placement and tuning power system stabilizer using participation factor and imperialist competitive algorithm in 150 kv south of sulawesi system," in 2015 international seminar on intelligent technology and its applications (isitia), 2015, pp. 147-152. [15] h. setiadi et al., "penalaan parameter superconducting magnetic energy storage (smes) menggunakan firefly algorithm (fa) pada sistem tenaga listrik multimesin," jurnal teknik its, vol. 3, no. 1, pp. b12-b17, 2014. [16] k. y. cheung et al., "large-scale energy storage systems," imperial college london, ise2, pp. 2002-2003, 2003. [17] m. h. ali et al., "enhancement of transient stability by fuzzy logic-controlled smes considering communication delay," international journal of electrical power & energy systems, vol. 31, no. 7, pp. 402-408, 2009. [18] m. m. t. ansari and s. velusami, "dual mode linguistic hedge fuzzy logic controller for an isolated wind–diesel hybrid power system with superconducting magnetic energy storage unit," energy conversion and management, vol. 51, no. 1, pp. 169181, 2010. [19] e. ali and s. abd-elazim, "tcsc damping controller design based on bacteria foraging optimization algorithm for a multimachine power system," international journal of electrical power & energy systems, vol. 37, no. 1, pp. 23-30, 2012. [20] j. f. kennedy et al., swarm intelligence. morgan kaufmann, 2001. [21] y. del valle et al., "particle swarm optimization: basic concepts, variants and applications in power systems," ieee transactions on evolutionary computation, vol. 12, no. 2, pp. 171-195, 2008. [22] m. clerc, particle swarm optimization. john wiley & sons, 2010. [23] a. u. krismanto et al., "influence of renewable energy based microgrid on low frequency oscillation of power systems," in 2015 ieee pes asia-pacific power and energy engineering conference (appeec), 2015, pp. 1-5. [24] s. panda, "differential evolutionary algorithm for tcsc-based controller design," simulation modelling practice and theory, vol. 17, no. 10, pp. 1618-1634, 2009. mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com https://dx.doi.org/10.14203/j.mev.2018.v9.8-16 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. preliminary investigation of sleep-related driving fatigue experiment in indonesia kadek heri sanjaya a, *, yukhi mustaqim kusuma sya'bana a, shaun hutchinson b, cyriel diels b a research centre for electrical power and mechatronics, indonesian institute of sciences jalan cisitu no. 21/154d, bandung, 40135, indonesia b centre for mobility and transport, coventry university priory street, coventry, cv15fb, united kingdom received 2 may 2017; received in revised form 23 may 2018; accepted 22 june 2018 published online 31 july 2018 abstract sleep-related driving fatigue has been recognized as one of the main causes of traffic accidents. in indonesia, experimentbased driving fatigue study is still very limited. therefore it is necessary to develop a laboratory-based experimental procedure for sleep-related fatigue study. in this preliminary study, we performed a literature review to find references for the procedure and three pilot experiments to test the instruments and procedure to be used in measuring driving fatigue. three subjects participated, both from experienced and inexperienced drivers. our pilot experiments were performed on a driving simulator using opends software with brake and lane change test reaction time measurement. we measured sleepiness by using karolinska sleepiness scale (kss) questionnaire. the conditions of the experiment were based on illumination intensity as well as preand post-lunch session. we found that lane change reaction time is more potential than brake reaction time to measure driving performance as shown by more fluctuating data. post-lunch seems to induce drowsiness greater than illumination intensity. kss questionnaire seems non-linear with driving performance data. we need to test further these speculations in the future studies involving a sufficient number of subjects. we also need to compare the effect of circadian rhythm and sleep deprivation on driving fatigue. the use of eye closure and physiological measurement in further study will enable us to measure driving fatigue more objectively. considering the limitations, more preliminary experiments are required to be performed before conducting the main experiment of driving fatigue. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: driving fatigue; sleepiness; experimental procedure; driving simulation. i. introduction road traffic accident which costs human life has been recognized as an important issue encountered by many countries [1]. the impacts of the accidents are much greater in developing countries where the accidents often take the life of the only income earner in the family [2]. among the various causes of roadtraffic accidents, driving fatigue has been reported to be one of the most common causes [3]. based on its causes, driving fatigue is classified into sleep-related and task-related fatigue [1][4]. the most common type of driving fatigue is drowsiness, which has been reported to cause accidents in many countries. in the united states, drowsiness was reported to be responsible for around 100,000 crashes annually, which resulted in more than a thousand fatalities, more than seventy thousands people injured and monetary losses of more than usd 10 billion [5]. drowsiness was responsible for more than a quarter of road fatalities in germany [5], and between 15 to 20% of traffic accidents in the uk [6]. in indonesia, around 21% of total traffic accidents recorded by jasa marga, an operator of the toll road in indonesia, were caused by sleepiness [6]. in the longest toll road in indonesia, tol cipali, 140 traffic accidents occurrence were recorded during its inauguration from june 2015 to october 2016 on which drowsiness has been suspected to be the main * corresponding author. tel: +62 22 250 3055, 250 4770 e-mail: kade001@lipi.go.id https://dx.doi.org/10.14203/j.mev.2018.v9.8-16 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.8-16 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.8-16&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 9 cause, as most of the accidents took place between midnight and early morning [7]. most drowsiness during driving is caused by lack of sleep before driving or driving at the time when most people usually sleep [8]. in the driving fatigue classification, sleep-related fatigue is caused by the sleep disorder, restriction, and deprivation as well as sleeping related with biological rhythm [1][4]. as reported that most accidents due to drowsiness occurred during the first 45 minutes of driving [8], which was well below driving fatigue due to a prolonged driving duration of three hours [9][10], it can be assumed that drowsiness during driving is more associated with sleep-related fatigue. research on driving drowsiness that measured indonesian subjects was still very few. our literature review found two studies on driving fatigue. the first study was a field study involved sixteen shuttle service drivers between bandung-jakarta using a digital video recorder (dvr) [6]. only twelve drivers completed the study. the variables measured in the study were eye-blink and microsleep frequency based on video-recorded eye closure and sleepiness incident, pattern and changes based on kss data. in the study, the subjects were recorded during prolonged driving tasks of around seven hours without any information about the time set up for the study. we speculated that the study had neglected the effects of environmental aspects such as temperature, humidity, and illumination as well as the effects of circadian rhythm on fatigue, as controlling those aspects is very challenging in a field study. the second study used an opends-based driving simulator that measured reaction time and kss data from both normal and sleep-deprived condition among twentyfive subjects [11]. the study reported longer reaction time among sleepy drivers. however, the second study did not provide any information about the characteristics of the subjects, the control of the laboratory environment such as temperature, humidity, and illumination, as well as the time set up of the experiment. both studies did not employ any physiological measurements. ii. method/material this article is limited to developing an experimental procedure for sleep-related fatigue study and no other types of inattention. as physiological measurement methods have been published in our previous article [1], in this study, the discussion is limited to driving fatigue experimental procedure, reaction time, and subjective assessment with kss questionnaire. a. literature review on standards and subjective assessment methods in this study, we focused on primary driving tasks and driver condition and behaviour. we regarded two guidelines for driving performance test from international organization for standardization (iso) and national highway traffic safety administration (nhtsa), united states of america, as the most widely referred in driving studies [12][13]. the two guidelines provide a very detail information on the experiment procedure based on an extensive database from previous studies. iso standards provide guidelines for studying lane change test to measure driver inattentiveness [14], which is the most common symptom of driving drowsiness. daimler also issued a lane change test guidelines [15], underlining the importance of this method for various types of driving simulator studies. lane change test is also relatively low-cost and easy to use [13]. the low-cost aspect, is very important in applied engineering research, especially in private companies. the applicability of the employed methods should avoid the so-called the “law of diminishing return” without sacrificing the reliability of the results [13]. a low-cost and easy to use method also means that it will be replicable by many researchers with limited resources, especially in developing countries. the adoption of the lane change test in an open source software like opends [16] will allow us to compare the results of our future study with other worldwide studies. there are various sleepiness scale questionnaires used in sleep-related studies, such as stanford sleepiness scale [17][18][19], pittsburg sleep quality index [18], kwansei gakuin sleepiness scale [20], and karolinska sleepiness scale [6][11][21][22][23]. karolinska sleepiness scale (kss) has been reported to be very sensitive to measure sleepiness level [24], across its different versions [23], applicable for both performance measurement [22] and drivers’ sleepiness level [21]. with regard to driving fatigue studies, kss is the one that has been used extensively in our references. kss has been reported to be as sensitive as objective measurement methods using electroencephalogram (eeg) and electro-oculogram (eog), and its reliability has also been examined in many studies [24]. there are two types of kss in english, the modified version is with label on every scale number from 1 to 9 (1 = extremely alert, 2 = very alert, 3 = alert, 4 = rather alert, 5 = neither alert nor sleepy, 6 = some signs of sleepiness, 7 = sleepy, but no effort to keep awake, 8 = sleepy, some effort to keep awake, 9 = very sleepy, great effort keeping awake, fighting sleep), while the original one is with label only on number 1, 3, 5, 7, 9 [23]. the version in bahasa indonesia refers to the original version [6], and we used this version in our preliminary experiment. b. pilot experiment the pilot experiment was performed in the dark room, graham sutherland building, coventry university. as shown in figure 1, the driving simulator used an opends [16] and lct sim [14][15] software, and modified game controllers logitech gt 5 (logitech international s.a., switzerland) to provide more realistic driving experience for the subjects. iso 26022:2010 suggests the minimum resolution for driving simulator display is 1024 × 768 pixel with a refresh rate of 50 hz [14]. we used 2048 × 1536 pixel for the experiment which is above the minimum standard. k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 10 three participants volunteered for the experiment. two of them were experienced drivers that possess indonesian driving license (sim a). one was an inexperienced driver without a driving license. all subjects were in healthy condition and aged in the early 30s. at the earliest stage, we allow the subjects to familiarise with the driving simulator by performing trials for more than 10 minutes. initially, two driving tasks were performed, namely lane change test using lct sim and reaction test using opends software. lane change test requires the driver to change lane continuously according to the road signs. the reaction test requires the driver to react to two types of road signs appeared on the gantries, namely brake and lane change sign. the driver should keep driving in the middle lane. for brake reaction test, the driver should push the brake pedal when a red cross appeared on the gantries, then release the brake and push the gas pedal when an auditory cue was given. the lowest speed during braking was 20 km/h and the top speed never exceeded 60 km/h. for lane change reaction test, the driver should change the lane from the middle lane to the lane with a green tick and then return to the middle lane when an auditory cue was given. brake reaction time was measured from the time of the sign appeared to the maximum brake push. lane change reaction time was measured from the sign appeared to the time when the vehicle was already in the intended lane. we decided to use the open ds-based reaction time test for the pilot experiment after trying the scenario and considering that lct sim is more appropriate for lane change test measurement related to secondary task effect. we did not measure secondary driving task such as the use of radio and lcd in this experiment. the first pilot experiment was performed from 1:00 p.m. to 5:00 p.m. each subject performed five trials, each trial was in 5 minutes. in this experiment, we tried to induce drowsiness upon the subjects by having them driving on a monotonous straight road continuously. the second pilot experiment was performed between 1:30 p.m. and 4:30 p.m. the subjects performed the driving task in eight sessions consecutively to induce drowsiness. in this session, the experiment was under high-intensity illumination when all the lighting in the room were turned on (figure 2). the third pilot experiment was conducted in the morning, from 10:00 a.m to 12:00 a.m, with the same task procedure of the second pilot experiment, but under low-intensity illumination when all the lighting were turned off (figure 3). right after completing every trial session, subjects answered the kss questionnaire. c. opends and kss data processing the use of opends software allows us to record the reaction time during trials. the data are shown in a bar diagram (figure 4). the red bar represents brake reaction time and the green bar represents lane change reaction time. the reaction time is in the millisecond. in every session, there were ten data for both brake and lane change test reaction time. whenever the reaction time was failed to be recorded, the data were excluded from further analysis. some outliers data in both brake and lane change reaction time test which is more than 10,000 milliseconds were excluded. because statistical power analysis is impossible in this preliminary experiment with a small number of subjects [14][25], we did not perform statistical significance analysis. we can assume that the more drowsy the drivers, the longer reaction time and the higher kss score. all data were input into microsoft excel 2010 to be processed into line charts. figure 1. the used driving simulator hardware for the experiment. it combined a driving wheel with pedals and chairs to simulate a real driving set up/experience figure 2. the second pilot experiment under high intensity illumination, when the lighting in the room was turned on figure 3. the third pilot experiment under low intensity illumination, when the lighting in the room was turned off k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 11 iii. result and discussion as this preliminary study only involved a small number of subjects, we cannot perform any deep analysis. this study only describes the possibility that we may record data using the tested methods. the result and discussion section include the description of the pilot experiment results and the improvements necessary for further experiments. we also discuss some assumption to be examined in the further preliminary experiment before conducting the main experiment. a. pilot experiment i in the four trials performed, all the three subjects participated in the first pilot experiment showed slightly but steady increase in brake reaction time from the first to the last trial (figure 5). as illustrated in figure 5, the inexperienced driver showed a different trend from the experienced driver in lane change reaction time. while experienced drivers showed increasing lane change reaction time, inexperienced driver, on the contrary, showed slightly lower reaction time at the last trial. this probably represents the effect of learning that has been reported in previous studies [26]. visually, the lane change reaction time fluctuates more than brake reaction time. we speculate that level of experience has a greater effect on lane change reaction time than brake reaction time. kss questionnaire data shows increasing sleepiness in the four trials among subjects (figure 6). one subject who had experience in answering kss questionnaire seems to show more steady increase than the other two subjects who responded to the questionnaire for the first time. b. pilot experiment ii in the second pilot experiment, only two subjects participated, an experienced driver and an inexperienced driver. as illustrated in figure 7, the experienced driver showed less fluctuation on brake reaction time than lane change reaction time. unlike the first pilot experiment, lane change reaction time was found to be the longest not at the last trial, but in the middle (trial 5; 4,177.2 ms). the last trial was found to result in the second longest reaction time (3,692.7 ms). the data from inexperienced driver also shows more fluctuation in lane change reaction. similar to the experienced driver, lane change reaction time from the inexperienced driver was also found to be the longest in the middle trial (trial 4; 5,873.5 ms). however, the inexperienced driver did not show an increase in lane change reaction time at the last trial. as illustrated in figure 8, kss questionnaire score shows the increasing level of sleepiness due to the prolonged driving task during the experiment. the pattern of changes in sleepiness level is not the same between both subjects. the steady increase of sleepiness seems non-linear to the reaction time. we suspect the effect of motivation since the subjects well understood the length of the experiment. the effect of motivation to overcome fatigue has been reported in a previous study [27]. boredom seems to reach its peak in the middle of the experiment session, whereas near to the end, the motivation of the subjects increases. therefore, they generate relatively shorter lane change reaction time. figure 4. reaction time data in bar diagram from opends k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 12 c. pilot experiment iii the two subjects from the second pilot experiment participated in the third pilot experiment. experienced driver’s data, as observed in the earlier experiments, showed greater fluctuation in lane change reaction time than brake reaction time (figure 9). similar to the second pilot experiment under a bright condition, the longest lane change reaction time was observed in the middle trial (trial 5; 2,884.5 ms). however, from the earliest to the last trial, lane change reaction time tends to become shorter. as found in other data, as illustrated in figure 9, the inexperienced driver also showed an only slight change in brake reaction time under dark condition. the inexperienced driver showed the longest lane change reaction time at trial 7 (3,981.3 ms). the last trial generated shorter lane change reaction time (2,421.4 ms) than the first trial (3,006.3 ms) and both the 6th (3,013.6 ms) and 7th trials. the fluctuation occurred from the 5th trial to the last trial. kss questionnaire data in figure 10 shows similar tendency with the second pilot experiment, where the level of sleepiness increased after the eight consecutive trials. as found in the earlier pilot experiments, even under the low illumination, the increase of sleepiness level is non-linear to reaction time data. due to the possibility of increasing motivation near the end of the experiment session, it is necessary to consider to eliminate the provision of the information on the length of the experiment to the subject. a monotonous task with uncertain time will induce boredom and mental fatigue, then the goal to make the subjects fall into drowsiness will be more effective. during the third pilot experiment, we also tried the use of an eye tracker instrument (dikablis eye tracker, ergoneers gmbh, germany). the most common application of eye tracker is for detecting the area of interest based on gaze movement [28][29][30][31]. eye movement has been reported to indicate crash risk [28], which is affected by distraction [29], declining visual capacity due to older age [30], and visual field impairment [31]. the eye tracker has two cameras: one records the eye movement (monocular), and the other records the front view of the subject. the eye tracker is able to measure the gaze point which means it may detect the time when the subject take his/her vision away from the road, and the time of eye closure figure 5. brake and lane change reaction time of the three subjects in pilot experiment i. lane change reaction time fluctuates more than brake reaction time figure 6. kss questionnaire score of the three subjects in pilot experiment i k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 13 which is a common method in drowsiness detection [32][33][34]. however, the eye tracker is relatively expensive and requires training for the operator to be able to use it properly. during the experiment, we had to perform calibration several times. we did not take specific quantitative data from eye tracker measurement during our pilot experiment. d. evaluation of pilot experiments considering this study is only a very early preliminary experiment, we cannot withdraw a general conclusion to develop a fundamental understanding of driving fatigue. some assumption needs to be tested in further experiments including the effects of driving experience which is greater on lane change reaction time, the non-linearity of kss score with driving performance measurement, and the effect of postlunch which is greater than illumination. we need to test these small findings with a larger number of subjects. our pilot experiments were performed with a very limited number of subjects. the previous study suggested that five participants may reveal about 80% of usability problems in a simulated task [13]. furthermore, many physiological studies employed only six to eight subjects, especially when the task is so demanding and collecting subjects is difficult. iso standard on lane change test suggests the involvement of at least 16 subjects in finding statistical significance in a within-subject study [14]. some simulator-based studies even employed more than 50 subjects [35]. the iso guidelines emphasize that all subjects should have a driving license and it is preferable that all the subjects have a similar level of driving experience and familiarity with the driving simulation task [14]. the guidelines are in line with our speculation on driving experience based on observation. inexperienced drivers have been reported to be less able in self-measuring their own condition, as such they have become the main target of the road safety campaign [36]. as the kss form used in bahasa indonesia refers to the original version with the label only on number 1, 3, 5, 7, and 9 [6], the inexperienced driver tended to circle those numbers only and pass the numbers without a label. kss score shows that regardless of the illumination, the post-lunch experiment session induces greater sleepiness. the reaction time data support this raw assumption in both the experienced and inexperienced drivers. the effect after having meal on post-lunch towards sleepiness during driving has been reported in previous studies [37][38], as worsen performance has been observed [39][40]. in future experiments, we should also measure sleeprelated fatigue during driving between midnight and early morning, which has also been reported to greatly induce drowsiness [1][41]. figure 7. reaction time data from pilot experiment ii. the experiment was conducted at post lunch figure 8. kss questionnaire score from pilot experiment k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 14 e. procedure for further experiment considering the small number of subjects, there are not many conclusions that can be taken. additionally, with a very limited number of participants which is only one for each group, there is a very high possibility that the results are limited to the exact person only, and cannot be said the same to other people. as such, further preliminary experiments with a gradually larger number of subjects should be performed. for the further preliminary study, we will involve at least five participants from each group to test the procedure. for the main experiment, we can conclude that the number of subjects should be more than sixteen, with all of them should possess a driving license. in a behavioral study with simple data processing methods, a much larger number up to more than 50 would provide greater significance for the experiment. in the use of physiological measurement methods, such as eeg and electrocardiogram (ecg), with very labouring and time-consuming digital signal analysis, a number of subjects of eight to ten people should suffice. compared to the previous study using opends [11], the effects of drowsiness on the longer reaction time is comparable. however, the previous study applied fatigue procedure by depriving subjects of sleeping the night before the experiment. in the future study, we also need to compare the effect of sleep deprivation, lunch, and driving during midnight, to examine which condition produce the worst driving performance. the use of lane change test can be complemented by performing probe reaction task or peripheral detection task (pdt) [14]. the demand for more realistic driving simulation has brought the complexity of real on-the-road driving into the laboratory study. for example, it is difficult to provide a surprise stimulus continuously, as it would be more predictable. thus, pdt will provide basic information on subjects the shortest reaction times in various experimental condition. the combination of pdt and driving simulation task will allow us to understand the condition of whole-body coordination, functional potentiality and environmental adaptability in driving. the good understanding of physiological effects of daily activities will provide enough information to design a future system that sustains our biological welfare [42], not only the short term of safety and comfort. we need to re-evaluate further the effectiveness of kss both the original and modified version. previous studies reported that there was no difference between the two versions [23]. the previous study involving opends and kss reported the non-linearity between figure 9. reaction time data from pilot experiment iii. the experiment was conducted at pre-lunch figure 10. kss questionnaire score from pilot experiment iii k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 15 the two measurements [11]. on the contrary, the field study measured eye closure and kss reported the high correlation between the two variables [6]. we also need to evaluate this contradiction in the future studies. the failure to employ an eye tracker in this pilot study made such analysis at the moment is impossible. with regard to eye movements recording, it is possible to use a video camera as replacement of eye tracker [32]. the video camera is cheap and easy to use. however, we may be required to develop and customize the data analysis method. iv. conclusion this preliminary study shows both the limitation and potential of the tested methods, namely lane change reaction time, brake reaction time, and kss questionnaire. the most significant speculation we formulate based on the experiment is that lunch and circadian rhythm probably has a greater effect on drowsiness than illumination in a simulated driving. we need to test this speculation with a larger number of subjects in the future study. with regard to the previous studies, we need to examine to which extent the effect of circadian rhythm and sleep deprivation in causing drowsiness. the measurement of eye closure apart from kss is also necessary to confirm the reliability of the subjective analysis. to be able to capture even the slightest change in driver condition, the use of physiological measurement instruments will greatly enhance this type of research. there are various necessary aspects to be tested in various pilot experiments. such aspects include instruments choice, the procedure to use the instruments and treatment of subjects, and the time of the experiments to meet the required condition. despite we found that lane change reaction time is probably more representative in fatigue condition than brake reaction time, we still need to develop and try the scenario, as opends allows such thing. to achieve a satisfying experiment procedure that leads to significant results, more pilot experiments need to be performed before the main experiment. acknowledgement this study was supported by rcepm-lipi and cmtr, coventry university. the authors wish to express gratitude to professor andrew parkes, dr. kevin vincent, mrs. barbara howell, mrs. kally gill, ms. lidia bombin martinez, and mr. rehan qureishi for invaluable help during our visit at coventry. this study is partially funded by the non-degree scholarship programme, indonesian ministry for research, technology and higher education. references [1] k. h. sanjaya et al., “review on the application of physiological and biomechanical measurement methods in driving fatigue detection,” j. mechatronics, electr. power, veh. technol., vol. 7, no. 1, p. 35, jul. 2016. [2] “kecelakaan lalu lintas menjadi pembunuh terbesar ketiga | badan intelijen negara republik indonesia.” [online]. available: http://www.bin.go.id/awas/detil/197/4/ 21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga. [accessed: 25-feb-2016]. [3] w. sun et al., “blink number forecasting based on improved bayesian fusion algorithm for fatigue driving detection,” math. probl. eng., pp. 1–13, 2015. [4] j. f. may and c. l. baldwin, “driver fatigue: the importance of identifying causal factors of fatigue when considering detection and countermeasure technologies,” transp. res. part f traffic psychol. behav., vol. 12, no. 3, pp. 218–224, 2009. [5] a. sahayadhas et al., “detecting driver drowsiness based on sensors: a review,” sensors (switzerland), vol. 12, no. 12, pp. 16937–16953, 2012. [6] m. mahachandra et al., “sleepiness pattern of indonesian professional driver based on subjective scale and eye closure activity,” int. j. basic appl. sci., vol. 11, no. 6, pp. 87–96, 2011. [7] o. d. sutrisno, “peristiwa | dalam 16 bulan, 140 kecelakaan terjadi di….” [online]. available: http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16bulan-140-kecelakaan-terjadi-di-tol-cipali. [accessed: 16-jan2017]. [8] m. l. lee et al., “high risk of near-crash driving events following night-shift work.,” proc. natl. acad. sci. u. s. a., vol. 113, no. 1, pp. 176–81, 2016. [9] l. l. di stasi et al., “microsaccade and drift dynamics reflect mental fatigue.,” eur. j. neurosci., vol. 38, no. 3, pp. 2389– 2398, 2013. [10] x. fan et al., “electroencephalogram assessment of mental fatigue in visual search,” biomed. mater. eng., vol. 26, no. 37, pp. 1455–1463, 2015. [11] i. n. isnainiyah et al., “analysis of sleep deprivation effect to driving performance using reactiontest simulation,” in proceedings of 2014 international conference on information, communication technology and system, icts 2014, 2014, vol. 4, pp. 7–12. [12] p. green and h. jeong, “sae and iso standards for warnings and other driver interface elements: a summary,” 2013. [13] s. pournami et al., “comparing the nhtsa and iso occlusion test protocols : how many participants are sufficient ?,” in proceedings of the 7th international conference on automotive user interfaces and interactive vehicular applications, 2015, no. november, pp. 110–116. [14] i. organization for standardization, road vehicles — ergonomic aspects of transport information and control systems — simulated lane change test to assess invehicle secondary task demand. 2010, p. 52. [15] daimlerchrysler ag research and technology, “lane change test 1 . 2 user guide,” test. daimlerchrysler ag research and technology, pp. 1–11, 2005. [16] “opends contre task (opends pro).” [online]. available: https://www.opends.eu/software/driving-tasks/15-controlleddriving-tasks/87-contre-task. [accessed: 05-jan-2017] [17] “stanford sleepiness scale.” [online]. available: https://web.stanford.edu/~dement/sss.html. [accessed: 26-jan2017]. [18] s. j. frenda et al., “sleep deprivation and false memories.,” psychol. sci., p. first online view, 2014. [19] r. atchley et al., “event-related potential correlates of mindfulness meditation competence,” neuroscience, vol. 320, no. november, pp. 83–92, 2016. [20] s. lee et al., “effect of simultaneous exposure to extremely short pulses of blue and green light on human pupillary constriction,” j. physiol. anthropol., vol. 35, no. 1, p. 20, 2016. [21] c. ahlstrom et al., “fit-for-duty test for estimation of drivers’ sleepiness level: eye movements improve the sleep/wake predictor,” transp. res. part c emerg. technol., vol. 26, pp. 20–32, 2013. [22] m. e. howard et al., “specific sleepiness symptoms are indicators of performance impairment during sleep deprivation,” accid. anal. prev., vol. 62, pp. 1–8, 2014. [23] a. å. miley et al., “comparing two versions of the karolinska sleepiness scale (kss),” sleep biol. rhythms, vol. 14, no. 3, pp. 257–260, 2016. [24] t. åkerstedt et al., “subjective sleepiness is a sensitive indicator of insufficient sleep and impaired waking function,” j. sleep res., vol. 23, no. 3, pp. 240–252, 2014. [25] i. organization for standardization, road vehicles — measurement of driver visual behaviour with respect to http://dx.doi.org/10.14203/j.mev.2016.v7.35-48 http://dx.doi.org/10.14203/j.mev.2016.v7.35-48 http://dx.doi.org/10.14203/j.mev.2016.v7.35-48 http://dx.doi.org/10.14203/j.mev.2016.v7.35-48 http://www.bin.go.id/awas/detil/197/4/21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga http://www.bin.go.id/awas/detil/197/4/21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga http://www.bin.go.id/awas/detil/197/4/21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga http://www.bin.go.id/awas/detil/197/4/21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga http://www.bin.go.id/awas/detil/197/4/21/03/2013/kecelakaan-lalu-lintas-pembunuh-terbesar-ketiga http://dx.doi.org/10.1155/2015/832621 http://dx.doi.org/10.1155/2015/832621 http://dx.doi.org/10.1155/2015/832621 https://doi.org/10.1016/j.trf.2008.11.005 https://doi.org/10.1016/j.trf.2008.11.005 https://doi.org/10.1016/j.trf.2008.11.005 https://doi.org/10.1016/j.trf.2008.11.005 https://doi.org/10.3390/s121216937 https://doi.org/10.3390/s121216937 https://doi.org/10.3390/s121216937 http://ijens.org/vol_11_i_06/117006-9393-ijbas-ijens.pdf http://ijens.org/vol_11_i_06/117006-9393-ijbas-ijens.pdf http://ijens.org/vol_11_i_06/117006-9393-ijbas-ijens.pdf http://ijens.org/vol_11_i_06/117006-9393-ijbas-ijens.pdf http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16-bulan-140-kecelakaan-terjadi-di-tol-cipali http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16-bulan-140-kecelakaan-terjadi-di-tol-cipali http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16-bulan-140-kecelakaan-terjadi-di-tol-cipali http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16-bulan-140-kecelakaan-terjadi-di-tol-cipali http://jabar.metrotvnews.com/peristiwa/vnnxbwvk-dalam-16-bulan-140-kecelakaan-terjadi-di-tol-cipali https://doi.org/10.1073/pnas.1510383112 https://doi.org/10.1073/pnas.1510383112 https://doi.org/10.1073/pnas.1510383112 https://doi.org/10.1111/ejn.12248 https://doi.org/10.1111/ejn.12248 https://doi.org/10.1111/ejn.12248 https://doi.org/10.3233/bme-151444 https://doi.org/10.3233/bme-151444 https://doi.org/10.3233/bme-151444 https://doi.org/10.1109/icts.2014.7010469 https://doi.org/10.1109/icts.2014.7010469 https://doi.org/10.1109/icts.2014.7010469 https://doi.org/10.1109/icts.2014.7010469 https://doi.org/10.1109/icts.2014.7010469 https://deepblue.lib.umich.edu/handle/2027.42/134039 https://deepblue.lib.umich.edu/handle/2027.42/134039 http://doi.org/10.1145/2799250.2799255 http://doi.org/10.1145/2799250.2799255 http://doi.org/10.1145/2799250.2799255 http://doi.org/10.1145/2799250.2799255 http://doi.org/10.1145/2799250.2799255 https://www.iso.org/standard/43361.html https://www.iso.org/standard/43361.html https://www.iso.org/standard/43361.html https://www.iso.org/standard/43361.html http://apps.usd.edu/coglab/schieber/pdf/lct-userguide.pdf http://apps.usd.edu/coglab/schieber/pdf/lct-userguide.pdf http://apps.usd.edu/coglab/schieber/pdf/lct-userguide.pdf https://www.opends.eu/software/driving-tasks/15-controlled-driving-tasks/87-contre-task https://www.opends.eu/software/driving-tasks/15-controlled-driving-tasks/87-contre-task https://www.opends.eu/software/driving-tasks/15-controlled-driving-tasks/87-contre-task https://web.stanford.edu/~dement/sss.html https://web.stanford.edu/~dement/sss.html https://web.stanford.edu/~dement/sss.html https://doi.org/10.1177/0956797614534694 https://doi.org/10.1177/0956797614534694 https://doi.org/10.1016/j.neuroscience.2016.01.051 https://doi.org/10.1016/j.neuroscience.2016.01.051 https://doi.org/10.1016/j.neuroscience.2016.01.051 https://doi.org/10.1186/s40101-016-0109-3 https://doi.org/10.1186/s40101-016-0109-3 https://doi.org/10.1186/s40101-016-0109-3 https://doi.org/10.1016/j.trc.2012.07.008 https://doi.org/10.1016/j.trc.2012.07.008 https://doi.org/10.1016/j.trc.2012.07.008 https://doi.org/10.1016/j.trc.2012.07.008 https://doi.org/10.1016/j.aap.2013.09.003 https://doi.org/10.1016/j.aap.2013.09.003 https://doi.org/10.1016/j.aap.2013.09.003 https://doi.org/10.1007/s41105-017-0111-0 https://doi.org/10.1007/s41105-017-0111-0 https://doi.org/10.1007/s41105-017-0111-0 https://doi.org/10.1111/jsr.12158 https://doi.org/10.1111/jsr.12158 https://doi.org/10.1111/jsr.12158 https://www.iso.org/standard/56621.html https://www.iso.org/standard/56621.html k.h. sanjaya et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 8–16 16 transport information and control systems part 1: definitions and parameters, no. june. 2014. [26] n. reed et al., “scotsim : an evaluation of the effectiveness of two truck simulators for professional driver training,” wokingham, 2007. [27] m. m. lorist et al., “the influence of mental fatigue and motivation on neural network dynamics; an eeg coherence study,” brain res., vol. 1270, pp. 95–106, 2009. [28] b. g. simon-morton et al., “keep your eyes on the road: young driver crash risk increases according to duration of distraction,” j. adolesc. health, vol. 54, no. 5, pp. s61–s67, 2014. [29] r. d. foss and a. h. goodwin, “distracted driver behaviors and distracting conditions among adolescent drivers: findings from a naturalistic driving study,” j. adolesc. health, vol. 54, no. 5, pp. s50–s60, 2014. [30] a.k. pradhan et al., “peer passenger influences on male adolescent drivers’ visual scanning behavior during simulated driving,” j. adolesc. health, vol. 54, no. 5, pp. s42–s49, 2014. [31] e. kasneci et al., “driving with binocular visual field loss? a study on a supervised on-road parcours with simultaneous eye and head tracking,” plos one, vol. 9, no. 2, 2014. [32] j. paone et al., “baseline face detection, head pose estimation, and coarse direction detection for facial data in the shrp2 naturalistic driving study,” in ieee intelligent vehicles symposium, proceedings, 2015, vol. 2015–augus, pp. 174– 179. [33] a. dasgupta et al., “a vision-based system for monitoring the loss of attention in automotive drivers,” ieee trans. intell. transp. syst., vol. 14, no. 4, pp. 1825–1838, 2013. [34] x. wu et al., “pilot’s visual attention allocation modeling under fatigue,” technol. heal. care, vol. 23, no. s2, pp. s373– s381, 2015. [35] c. diels et al., “full time through junction running simulation study,” wokingham, 2010. [36] r. o. phillips and f. sagberg, “road accidents caused by sleepy drivers: update of a norwegian survey,” accid. anal. prev., vol. 50, no. may 2014, pp. 138–146, 2013. [37] l. a. reyner et al., “‘post-lunch’ sleepiness during prolonged, monotonous driving — effects of meal size,” physiol. behav., vol. 105, no. 4, pp. 1088–1091, 2012. [38] s. garbarino et al., “sleepiness, safety and transport,” j. ergon., vol. s3, no. 01, pp. 0–6, 2014. [39] t. h. monk, “the post-lunch dip in performance,” clin. sports med., vol. 24, no. 2, pp. 15–23, 2005. [40] v. van der vinne et al., “timing of examinations affects school performance differently in early and late chronotypes,” j. biol. rhythms, vol. 30, no. 1, pp. 53–60, 2015. [41] d. hallvig et al., “real driving at night – predicting lane departures from physiological and subjective sleepiness,” biol. psychol., vol. 101, pp. 18–23, 2014. [42] y. shimomura and t. katsuura, “sustaining biological welfare for our future through consistent science.,” j. physiol. anthropol., vol. 32, no. 1, p. 1, 2013. https://www.iso.org/standard/56621.html https://www.iso.org/standard/56621.html https://trl.co.uk/sites/default/files/ppr214_text%283%29.pdf https://trl.co.uk/sites/default/files/ppr214_text%283%29.pdf https://trl.co.uk/sites/default/files/ppr214_text%283%29.pdf https://doi.org/10.1016/j.brainres.2009.03.015 https://doi.org/10.1016/j.brainres.2009.03.015 https://doi.org/10.1016/j.brainres.2009.03.015 https://doi.org/10.1016/j.jadohealth.2013.11.021 https://doi.org/10.1016/j.jadohealth.2013.11.021 https://doi.org/10.1016/j.jadohealth.2013.11.021 https://doi.org/10.1016/j.jadohealth.2013.11.021 https://doi.org/10.1016/j.jadohealth.2014.01.005 https://doi.org/10.1016/j.jadohealth.2014.01.005 https://doi.org/10.1016/j.jadohealth.2014.01.005 https://doi.org/10.1016/j.jadohealth.2014.01.005 https://doi.org/10.1016/j.jadohealth.2014.01.004 https://doi.org/10.1016/j.jadohealth.2014.01.004 https://doi.org/10.1016/j.jadohealth.2014.01.004 https://doi.org/10.1371/journal.pone.0087470 https://doi.org/10.1371/journal.pone.0087470 https://doi.org/10.1371/journal.pone.0087470 https://doi.org/10.1109/ivs.2015.7225682 https://doi.org/10.1109/ivs.2015.7225682 https://doi.org/10.1109/ivs.2015.7225682 https://doi.org/10.1109/ivs.2015.7225682 https://doi.org/10.1109/ivs.2015.7225682 https://doi.org/10.1109/tits.2013.2271052 https://doi.org/10.1109/tits.2013.2271052 https://doi.org/10.1109/tits.2013.2271052 https://doi.org/10.3233/thc-150974 https://doi.org/10.3233/thc-150974 https://doi.org/10.3233/thc-150974 http://assets.highways.gov.uk/specialist-information/knowledge-compendium/2009-11-knowledgehttp://assets.highways.gov.uk/specialist-information/knowledge-compendium/2009-11-knowledgehttps://doi.org/10.1016/j.aap.2012.04.003 https://doi.org/10.1016/j.aap.2012.04.003 https://doi.org/10.1016/j.aap.2012.04.003 https://doi.org/10.1016/j.physbeh.2011.11.025 https://doi.org/10.1016/j.physbeh.2011.11.025 https://doi.org/10.1016/j.physbeh.2011.11.025 http://dx.doi.org/10.4172/2165-7556.s3-003 http://dx.doi.org/10.4172/2165-7556.s3-003 https://doi.org/10.1016/j.csm.2004.12.002 https://doi.org/10.1016/j.csm.2004.12.002 https://doi.org/10.1177/0748730414564786 https://doi.org/10.1177/0748730414564786 https://doi.org/10.1177/0748730414564786 https://doi.org/10.1177/0748730414564786 https://doi.org/10.1016/j.biopsycho.2014.07.001 https://doi.org/10.1016/j.biopsycho.2014.07.001 https://doi.org/10.1016/j.biopsycho.2014.07.001 https://dx.doi.org/10.1186%2f1880-6805-32-1 https://dx.doi.org/10.1186%2f1880-6805-32-1 https://dx.doi.org/10.1186%2f1880-6805-32-1 mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.php/ mev/login need a username/password? go to registration at: http://mevjournal.com/index.php/ mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nc-licensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 editor-in-chief prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 asscociate editors dian andriani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia aam muharam, m.t. asem, interdisciplinary graduate school of engineering kyushu university fukuoka, japan yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, republic of korea roni permana saputra, m.eng dyson school of design engineering robot intelligence lab imperial college, london, united kingdom tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 © 2018 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, seven papers are published with the total number of paper pages of 60 pages. the authors came from indonesia, south korea, saudi arabia, and viet nam. two papers are related to mechatronics which address design of a lower limb rehabilitation device, and an omnidirectional mobile robot design and its contol. two papers fall in electrical power topic. the first paper reports design of a maximum power point tracking method using fuzzy logic for photovoltaic (pv) panels. the second paper proposes a method for battery-balancing. three papers are classified in to vehicular technology topic. two of them report experiment results regarding fuel mix, engine performance, and emission reduction. the rest paper deals with control method of an electric bus which provides good energy efficiency. since the first volume, our journal provides discretion in financial term by waiving the article processing charge. we wish to offer our thanks to the indonesian institute of sciences (lipi) for their continuing unwaving support. also, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2018 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 ii list of contents combustion duration influence on hydrogen-ethanol dual fueled engine emissions: an experimental analysis syed yousufuddin ........................................................................................................................... 41-48 thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various loads condition yanuandri putrasari, achmad praptijanto, arifin nur, widodo budi santoso, mulia pratama, ahmad dimyani, suherman, bambang wahono, muhammad khristamto aditya wardana, ocktaeck lim .............................................................. 49-56 efficiency improvement of photovoltaic by using maximum power point tracking based on a new fuzzy logic controller machmud effendy, nuralif mardiyah, khusnul hidayat .............................................................. 57-64 study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder dao minh duc, pham dang phuoc, tran xuan tuy, le thi thuy tram ...................................... 65-72 enhancement of motionability based on segregation of states for holonomic soccer robot gunawan dewantoro, anton suprayudi, daniel santoso ............................................................ 73-80 implementation of a lifepo4 battery charger for cell balancing application amin, kristian ismail, abdul hapid .............................................................................................. 81-88 designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency rina ristiana, arief syaichu rohman, estiko rijanto, agus purwadi, egi hidayat, carmadi machbub ...................................................................................................................... 89-100 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 09, issue 2, december 2018 abstracts sheet e-issn: 2088-6985 date of issues: 30 december 2018 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. syed yousufuddin (department of mechanical engineering, jubail university college, saudi arabia) combustion duration influence on hydrogen-ethanol dual fueled engine emissions: an experimental analysis journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 41-48, 10 ill, 2 tab, 15 ref. the research presented in this article expresses experimental results of combustion duration effect on a dual fueled engine. in particular, the research was focused on the emissions occurred specifically from a hydrogen-ethanol dual fueled engine. this study was performed on a compression ignition engine that was converted to run and act as a spark ignition engine. this modified engine was fueled by hydrogen–ethanol with various percentage substitutions of hydrogen. the substitution was altered from 20 to 80% at a constant speed of 1500 rpm. the various engine emission characteristics such as co, hydrocarbon, and nox were experimentally determined. this study resulted that at a compression ratio of 11:1 and combustion duration of 25°ca, the best operating conditions of the engine were shown. moreover, the optimum fuel combination was established at 60 to 80% of hydrogen substitution to ethanol. the experimental results also revealed that at 100% load and at compression ratios 7, 9, and 11; the co and hc emissions have decreased while nox increased and followed with the increase in the percentage of hydrogen addition and combustion duration. it was concluded that the retarding combustion duration was preferred for nox emission control in the engine. (author) keywords: combustion duration; compression ratio; dual fuel engine; alternative fuels; compression ignition; spark timing. yanuandri putrasari a, b, *, achmad praptijanto a, arifin nur a, widodo budi santoso a, mulia pratama a, ahmad dimyani a, suherman a, bambang wahono a, b, muhammad khristamto aditya wardana a, b, ocktaeck lim c (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b graduate school of mechanical engineering university of ulsan mugeo-dong, south korea; c school of mechanical engineering university of ulsan, south korea) thermal efficiency and emission characteristics of a dieselhydrogen dual fuel ci engine at various loads condition journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 49-56, 7 ill, 2 tab, 19 ref. efforts to find alternative fuels and reduce emissions of ci engines have been conducted, one of which is the use of diesel-hydrogen dual fuel. one of the goals of using hydrogen in dual-fuel combustion systems is to reduce particulate emissions and increase engine power. this study investigates the thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various loads condition. the hydrogen was used as a secondary fuel in a single cylinder 667 cm3 diesel engine. the hydrogen was supplied to intake manifold by fumigation method, and diesel was injected directly into the combustion chamber. the results show that the performance test yielding an increase around 10% in the value of thermal efficiency of diesel engines with the addition of hydrogen either at 2000 or 2500 rpm. meanwhile, emission analyses show that the addition of hydrogen at 2000 and 2500 rpm lead to the decrease of nox value up to 43%. furthermore, the smokeless emissions around 0% per kwh were occurred by hydrogen addition at 2000 and 2500 rpm of engine speeds with load operation under 20 nm. (author) keywords: dual-fuel hydrogen; hydrogen engines; diesel-hydrogen; diesel-hydrogen efficiency; diesel-hydrogen emissions. machmud effendy*, nuralif mardiyah, khusnul hidayat (electrical department, university of muhammadiyah malang, indonesia) efficiency improvement of photovoltaic by using maximum power point tracking based on a new fuzzy logic controller journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 57-64, 10 ill, 6 tab, 15 ref. maximum power point tracking (mppt) is a technique to maximize the power output of a photovoltaic (pv). therefore, to achieve higher pv efficiency, the development of mppt control algorithm is necessary. recently, it was revealed that, in certain conditions, fuzzy logic controller (flc) is better than other control algorithms and is possible to be developed. this study fabricated and implemented mppt based on the proposed a new flc. input calculator (ic) via sensors reads current and voltage of pv and generates the comparison of voltage and current of pv, then ic output becomes fuzzy algorithm input. fuzzy algorithm produces duty cycle that drives synchronous buck converter. the result showed that mppt system with the proposed flc method has 99.1% efficiency while mppt system with p&o method has 95.5% efficiency. from the obtained result, it can be concluded that the mppt based on the proposed flc can increase the overall efficiency of the system to 99.3%. (author) keywords: maximum power point tracking; fuzzy logic controller; photovoltaic efficiency; synchronous buck converter. dao minh duc a, *, pham dang phuoc a, tran xuan tuy b, le thi thuy tram c (a faculty of engineering technology, pham van dong university, vietnam; b faculty of mechanical, university of science and technology, vietnam; c department of electrical and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv electronics, technological colleges quang nam, vietnam) study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 65-72, 14 ill, 0 tab, 15 ref. a lower limb rehabilitation device was designed using the compressed air cylinder in order to answer the particular request in vietnam. this paper is presenting the results of a study of the device response. dynamic equation of the actuator and equations of the proportional valve have been established. the relationship between the input signal and the output signal of the actuator was derived. inventor® software was used to design the mechanical structure of the device. matlab® software was used to calculate the parameters values of the pid controller by simulating the response of the actuator. the results show that the response time of both knee drive and hip drive mechanisms are 8 seconds while the overshoot of both knee drive and hip drive mechanisms are 1%. moreover, the starting torque of the knee drive mechanism is 17 nm, and the starting torque of the hip drive mechanism is 35 nm. the simulation results show that the pid controller gives a fast response time and a low overshoot. (author) keywords: lower limb rehabilitation; hip and knee joint; pneumatic cylinder; pid controller. gunawan dewantoro*, anton suprayudi, daniel santoso (faculty of electronics and computer engineering, satya wacana christian university, indonesia) enhancement of motionability based on segregation of states for holonomic soccer robot journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 73-80, 10 ill, 2 tab, 15 ref. one of the critical issues when navigating a wheeled robot is the ability to move effectively. omnidirectional robots might overcome these nonholonomic constraints. however, the motion planning and travel speed of the movement has been in continuous research. this study proposed segregation of states to improve the holonomic motion system with omnidirectional wheels, which is specially designed for soccer robots. the system used five separate defined states in order to move toward all directions by means of speed variations of each wheel, yielding both linear and curved trajectories. the controller received some parameter values from the main controller to generate robot motion according to the game algorithm. the results show that the robot is able to move in an omnidirectional way with the maximum linear speed of 3.2 m/s. the average error of movement direction is 4.3°, and the average error of facing direction is 4.8°. the shortest average time for a robot to make a rotational motion is 2.84 seconds without any displacement from the pivot point. also, the robot can dribble the ball forward and backward successfully. in addition, the robot can change its facing direction while carrying the ball with a ball shift of less than 15 cm for 5 seconds. the results show that state segregations improve the robots capability to conduct many variations of motions, while the ball-handling system is helpful to prevent the ball get disengaged from the robot grip so the robot can dribble accordingly. (author) keywords: holonomic motion; omnidirectional robot; soccer robot; ball-handling. amin*, kristian ismail, abdul hapid (research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia) implementation of a lifepo4 battery charger for cell balancing application journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 81-88, 9 ill, 2 tab, 20 ref. cell imbalance has always happened in the series-connected battery. series-connected battery needs to be balanced to maintain capacity and maximize the batteries lifespan. cell balancing helps to dispart energy equally among battery cells. for active cell balancing, the use of a dc-dc converter module for cell balancing is quite common to achieve high efficiency, reliability, and high power density converter. this paper describes an implementation of a lifepo4 battery charger based on the dc-dc converter module used for cell balancing application. a constant current-constant voltage (cc-cv) controller for the charger, which is a general charging method applied to the lifepo4 battery, is presented for preventing overcharging when considering the nonlinear property of a lifepo4 battery. the prototype is made up with an input voltage of 43 v to 110 v and the maximum output voltage of 3.75 v, allowing to charge a lifepo4 cell battery and balancing the battery pack with many cells from 15 to 30 cells. the goal is to have a lifepo4 battery charger with an approximate power of 40w and the maximum output current of 10 a. experimental results on a 160ah lifepo4 battery for some state of charge (soc) shows that the maximum battery voltage has been limited at 3.77 v, and maximum charging current could reach up to 10.64 a. the results show that the charger can maintain battery voltage at the maximum reference voltage and avoid the lifepo4 battery from overcharging. (author) keywords: cell balancing; constant current-constant voltage (cccv); dc-dc converter module; lifepo4 battery. rina ristiana a, b, *, arief syaichu rohman a, estiko rijanto c, agus purwadi a, egi hidayat a, carmadi machbub a (a school of electrical engineering and informatics, institut teknologi bandung, indonesia; b instrumentation development unit, indonesian institute of sciences, indonesia; c research centre for electrical power and mechatronics, indonesian institute of sciences , indonesia) designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency journal of mechatronics, electrical power, and vehicular technology, december 2018, vol. 9, no. 2, p. 89-100, 7 ill, 2 tab, 15 ref. this paper develops an optimal speed control using a linear quadratic integral (lqi) control standard with/without an observer in the system based on an integrated battery-electric vehicle (ibev) model. the ibev model includes the dynamics of the electric motor, longitudinal vehicle, inverter, and battery. the ibev model has one state variable of indirectly measured and unobservable, but the system is detectable. the objectives of this study were: (a) to create a speed control that gets the exact solution for a system with one indirect measurement and unobservable state variable; and (b) to create a speed control that has the potential to make a more efficient energy system. a full state feedback lqi controller without an observer is used as a benchmark. two output feedback lqi controllers are designed; including one controller uses an order-4 observer and the other uses an order-5 observer. the order-4 observer does not include the battery state of charge as observer state. whereas the order-5 observer is designed by making all the state variable as the observer state and using the battery state of charge as an additional system output. an electric passenger minibus for public transport with 1500 kg weight was used as the vehicle model. simulations were performed when the vehicle moves in a flat surface with the increased speed from stationary to 60 km/h and moves according to standard nedc driving profile. the simulation results showed that both the output feedback lqi controllers provided similar speed performance as compared to the full state feedback lqi controller. however, the output feedback lqi controller with the order-5 observer consumed less energy than that with the order-4 observer about 10% for nedc driving profile and 12% for a flat surface. it is concluded that the lqi controller with order-5 observer gives better energy efficiency than the lqi controller with order-4 observer. (author) keywords: integrated battery-electric vehicle (ibev) model; speed control; electric vehicle; linear quadratic integral; observer system; energy efficient. mev journal of mechatronics, electrical power, and vehicular technology 10 (2019) 61-71 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.61-71 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. [retracted] design and development of the semg-based exoskeleton strength enhancer for the legs mikecon cenit, vaibhav gandhi* department of design engineering and mathematics, middlesex university london the burroughs, hendon, london, nw4 4bt, united kingdom article retraction notification: this article has been retracted. please see mev policy on article withdrawal at: (http://mevjournal.com/index.php/mev/pages/view/article-withdrawal) the authors and the editorial boards agree to retract this article due to technical matter and should not be included in this issue (vol 10, 2019). the publisher hereby confirms that the retraction of this article was in no way due to any flawed data, image manipulation, or misleading information by the authors. the publisher deeply regrets the impact of this action. republish version of this document can be found at http://dx.doi.org/10.14203/j.mev.2020.v11.64-74 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). https://dx.doi.org/10.14203/j.mev.2019.v10.61-71 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.61-71 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.61-71&domain=pdf http://mevjournal.com/index.php/mev/pages/view/article-withdrawal http://dx.doi.org/10.14203/j.mev.2020.v11.64-74 https://creativecommons.org/licenses/by-nc-sa/4.0/ mev journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2017.v8.60-69 2088-6985 / 2087-3379 ©2017 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. design and implementation of hardware in the loop simulation for electric ducted fan rocket control system using 8-bit microcontroller and real-time open source middleware reza aulia yulnandi, carmadi machbub *, ary setijadi prihatmanto, egi muhammad idris hidayat school of electrical engineering and informatics, institut teknologi bandung jl. ganesha 10, bandung 40132, indonesia received 28 april 2017; received in revised form 22 june 2017; accepted 02 july 2017 published online 31 july 2017 abstract hardware in the loop simulation (hils) is intended to reduce time and development cost of control system design. hils systems are mostly built by integrating both controller hardware and simulator software where the software is not an open source. moreover, implementing hils by using manufactured system is costly. this paper describes the design and implementation of hils for electric ducted fan (edf) rocket by using open-source platform for development with middleware. this middleware system is used to bridge the data flow between controller hardware and simulator software. a low-cost atmega 2560 8-bit microcontroller is used to calculate rocket’s attitude with direction cosine matrix (dcm) algorithm and pid controller is employed to regulate rocket’s dynamics based on desired specifications. x-plane 10 simulator software is used for generating simulated sensory data. the test results validate that hils design meets the defined specifications, i.e. angle difference of 0.3 degrees and rise time of 0.149 seconds on pitch angle. ©2017 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: hils; dcm; open-source platform; x-plane; middleware; edf rocket i. introduction electric-ducted fan (edf) rocket is one class of rocket that uses electric thruster as its main actuator [1]. it gains popularity for education and research purposes due its low cost and versatility. one important subsystem of an edf rocket is the autopilot system [2]. testing an autopilot system in a real experiment directly would lead to a high risk of failure due to its low durability and a high cost. computer’s system evolution creates the development of simulation method by using the virtual environment to imitate real situation became more preferable [3]. however, simulation result does not always give the same result as the real implementation process due to the uncertainty in electronic hardwares. therefore, hardware in the loop simulation (hils) approach is used. hils is the simulation system that integrates hardware system to simulation process. hils have been carried out to improve the accuracy of results [4, 5, 6]. most of the development processes use costly controller hardware such as motorola's mpc5554-mcu [7]. this hardware is not suitable for simple autonomous system such as proportional integral derivative (pid) algorithm due to the high cost which is not in accordance with the achieved performance. pid algorithm does not need to have a very highspeed processing unit to produce a control signal. hardware with average speed processing will be sufficient to handle the control process. it also does not need a large memory capacity to store the program code. moreover, most of the hils use integrated hardware and software system which is not an open source, not a re-programmable nor having non-free license [8, 9, 10]. * corresponding author. tel: +62 22 250 0960 e-mail address: carmadi@stei.itb.ac.id https://dx.doi.org/10.14203/j.mev.2017.v8.60-69 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2017.v8.60-69 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.60-69&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 61 in this paper, the design and implementation of hils system is presented, with the main contribution of exposing three main subsystems which are middleware design to ease bridge process, controller hardware, and simulator software. the middleware performance will be validated through comparison between sensor from simulator software and sensor from sensory hardware with attitude control mechanism to imitate simulator software. ii. component of hils the hils system consists of three subsystems, i.e. controller hardware, simulator software, and middleware system.  controller hardware acts as the main control unit in hils. this subsystem also controls sensory data retrieval both from sensory hardware and simulator software.  simulator software generates sensory data as replacement of sensory hardware, establish a virtual environment to test and provide the simulated dynamics of edf rocket.  middleware system bridges the data flow between controller hardware and simulator software. the middleware system is essential since hardware and software have different communication protocols. microcontroller hardware uses universal asynchronous receive transmit (uart) protocol and simulator software uses user datagram protocol (udp). illustration of each subsystem’s tasks is shown in figure 1. iii. design specification the hils system for edf rocket control system uses an 8-bit microcontroller as a main processing unit. the hils system is designed to meet the following specifications:  the minimum sampling rate of attitude data from simulator software to controller hardware with 100 samples/second due to the middleware has to provide data with sampling rate that approach the sampling rate from sensory hardware.  the error of simulated sensor from software simulation to sensory hardware does not exceed 2° in steady-state condition.  the performance difference of rise time in control process with the same parameter of pid between the simulated sensor and sensory hardware from an initial condition to reach the reference point does not exceed 1 second and steady-state error < 2%. iv. implementation a. controller hardware controller hardware is assigned to process the sensory data and generate the control signal. typically, hils is built with 64/32-bit singleboard computer as the main processing-unit. this kind of board costs relatively high and is not preferred for trivial computation. in this work the 8-bit microcontroller of atmega2560 is used to achieve the desired design specifications. this processing unit should be sufficient to meet the specifications based on the following features:  it has 16 mhz clock speed to calculate attitude and control algorithm which takes 100-120μs.  it has uart protocol for data transfer from microcontroller to personal computer through serial port (rs232) with transfer rate up to 250kbps that can achieve minimum sampling rate of 100 samples/second according to design specification.  it has 400 khz inter integrated circuit (i2c) communication protocol to send sensory data from imu to microcontroller in a compact module as shown in figure 2.  it has 256 kb flash memory to store program data and 1kb eeprom should be adequate for calibration data storage.  it has interrupt features for pulse generator to drive motor servo that will be used to change rocket’s control surface position as shown in figure 2. figure 1. functional subsystems of hils figure 2. realization of hils r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 62 the sensory system of our edf rocket consists of few attitude sensors:  mpu6050 as accelerometer and gyroscope with 50 hz data sampling rate and 16-bit word length.  hmc5883 as magnetometer with 10 hz data sampling rate and 12-bit word length.  ms561101ba as barometer with 10 hz data sampling rate and 24-bit word length. gyroscope sensor produces angular velocity to directly calculate the plant’s orientation. however, gyroscope cannot be used for long term measurement because it has drift in sensing process. accelerometer and magnetometer can be used for long-term measurement but they are slower in generating data. therefore, those cannot be used for short term calculation. 1) attitude calculation algorithm and sensor fusion direction cosine matrix method is used to compute the euler angles using information from the gyro, accelerometer, magnetic compass and/or gps [11]. advantages of this algorithm are its implementation simplicity which can be linearly calculated. hence, it requires light and short-duration computation. vectors 𝑖, 𝑗, 𝑘 represent vector body and vectors 𝐼, 𝐽, 𝐾 represent vector global as shown in figure 3. the vector can be described as follow: 𝑖𝐵 = [ 1 0 0 ] , 𝑗𝐵 = [ 0 1 0 ] , 𝑘𝐵 = [ 0 0 1 ] 𝐼𝐺 = [ 1 0 0 ] , 𝐽𝐺 = [ 0 1 0 ] , 𝐾 𝐺 = [ 0 0 1 ] the projection of vector 𝑖 toward the x-axis of global coordinate frame can be described as 𝑖𝑥 𝐺 = |𝑖|𝑐𝑜𝑠(𝑋, 𝑖) = 𝑐𝑜𝑠(𝐼, 𝑖) (1) where |𝑖| is normalization of vector 𝑖 and 𝑐𝑜𝑠(𝐼, 𝑖) is cosine angle that created by vector 𝐼 and vector 𝑖 . when |𝐼| = 1 dan |𝑖| =1, equation (1) can be written as 𝑖𝑥 𝐺 = 𝑐𝑜𝑠(𝐼, 𝑖) = 𝐼.𝑖 |𝐼||𝑖| . since 𝑐𝑜𝑠(𝑎, 𝑏) = 𝑎.𝑏 |𝑎||𝑏| , then 𝑖𝑥 𝐺 = |𝐼||𝑖|𝑐𝑜𝑠(𝐼, 𝑖) = 𝐼. 𝑖 (2) similarly, the projections of vector 𝑖 toward the other axes are given as follow: 𝑖𝑦 𝐺 = |𝐽||𝑖|𝑐𝑜𝑠(𝐽, 𝑖) = 𝐽. 𝑖 (3) 𝑖𝑧 𝐺 = |𝐾||𝑖|𝑐𝑜𝑠(𝐾, 𝑖) = 𝐾. 𝑖 (4) then equations (2), (3) and (4) can be written as 𝑖 𝐺 = [ 𝑖𝑥 𝐺 𝑖𝑦 𝐺 𝑖𝑧 𝐺 ] = [ 𝐼. 𝑖 𝐽. 𝑖 𝐾. 𝑖 ], 𝑗𝐺 = [ 𝑗𝑥 𝐺 𝑗𝑦 𝐺 𝑗𝑧 𝐺 ] = [ 𝐼. 𝑗 𝐽. 𝑗 𝐾. 𝑗 ], 𝑘𝐺 = [ 𝑘𝑥 𝐺 𝑘𝑦 𝐺 𝑘𝑧 𝐺 ] = [ 𝐼. 𝑘 𝐽. 𝑘 𝐾. 𝑘 ] vector 𝑖, 𝑗, 𝑘 in global coordinate can be described as follow: [𝑖 𝐺 𝑗𝐺 𝑘𝐺 ] = [ 𝐼. 𝑖 𝐼. 𝑗 𝐼. 𝑘 𝐽. 𝑖 𝐽. 𝑗 𝐽. 𝑘 𝐾. 𝑖 𝐾. 𝑗 𝐾. 𝑘 ] = [ 𝑐𝑜𝑠(𝐼, 𝑖) 𝑐𝑜𝑠(𝐼, 𝑗) 𝑐𝑜𝑠(𝐼, 𝑘) 𝑐𝑜𝑠(𝐽, 𝑖) 𝑐𝑜𝑠(𝐽, 𝑗) 𝑐𝑜𝑠(𝐽, 𝑘) 𝑐𝑜𝑠(𝐾, 𝑖) 𝑐𝑜𝑠(𝐾. 𝑗) 𝑐𝑜𝑠(𝐾, 𝑘) ] = 𝐷𝐶𝑀𝐺 vector 𝐼, 𝐽, 𝐾 in body coordinate can be described as follow: [ib jb kb] = [ i. i j. i k. i i. j j. j k. j i. k j. j k. k ] = [ cos(i, i) cos(j, i) cos(k, i) cos(i, j) cos(j, j) cos(k, j) cos(i, k) cos(j, k) cos(k, k) ] = dcmb dcm defines the rotation of plant body toward other coordinate. dcm also can be used to determine vector coordinates global of motion in case that the vector coordinates body of motion is known (vice versa). according to figure 4, the basic equation of rotation vector on axis are 𝑟 = 𝑟(𝑡), 𝑟′ = 𝑟(𝑡 + 𝑑𝑡), 𝑑𝑟 = 𝑟′ − 𝑟 where, vector r' is rotation vector with angle vector dθ in interval time dt on axis vector u. then vector u is cross product for r and r' figure 3. vector body (white) and vector global (black) figure 4. rotating vector on axis r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 63 𝑢 = 𝑟×𝑟′ |𝑟×𝑟′| = 𝑟×𝑟′ |𝑟||𝑟′| sin(𝑑𝜃) = 𝑟×𝑟′ |𝑟|2 sin(𝑑𝜃) (5) where, |𝑟| = |𝑟′| since rotation process does not alter length of vector. the linear velocity of vector r can be defined as vector 𝑣 = 𝑑𝑟 𝑑𝑡 = 𝑟′−𝑟 𝑑𝑡 (6) angular rate of displacement vector r can be described as follow: 𝑤 = 𝑑𝜃 𝑑𝑡 𝑢 (7) the equation (8) is obtained by substituting equation (5) to equation (7). 𝑤 = 𝑑𝜃 𝑑𝑡 𝑢 = 𝑑𝜃 𝑑𝑡 𝑟×𝑟′ |𝑟|2 sin(𝑑𝜃) = 𝑟×𝑟′ |𝑟|2𝑑𝑡 (8) hence for small dθ, sin(𝑑𝜃) ≈ 𝑑𝜃, the equation (9) is obtained as follow: 𝑤 = 𝑟×𝑟′ |𝑟|2𝑑𝑡 = 𝑟×(𝑟+𝑑𝑟) |𝑟|2𝑑𝑡 = (𝑟×𝑟)+(𝑟×𝑑𝑟) |𝑟|2𝑑𝑡 𝑤 = 𝑟×𝑑𝑟 |𝑟|2𝑑𝑡 = 𝑟×𝑣 |𝑟|2 (9) vector 𝑣 is described by deriving the equation as follow: 𝑤 × 𝑟 = (𝑟∙𝑟)𝑣+(𝑣∙𝑟)𝑟 |𝑟|2 = |𝑟|2∙𝑣 |𝑟|2 + 0 |𝑟|2 = |𝑟|2∙𝑣 |𝑟|2 = 𝑣 therefore: drx = dt vx = wx × r dt dry = dt vy = wy × r dt drz = dt vz = wz × r dt then 𝑣 = 𝑑𝑟 𝑑𝑡 = (𝑤𝑥 + 𝑤𝑦 + 𝑤𝑧) × 𝑟 dcm equation can be used to define a sensory system to implement sensors fusion for calculating attitude of the plant. as mentioned to previous section, each of sensory hardware’s measurement data can be described as follow: 𝐴 = {𝐴𝑥 , 𝐴𝑦, 𝐴𝑧 } is accelerometer sensor data 𝑀 = {𝑀𝑥 , 𝑀𝑦 , 𝑀𝑧 } is magnetometer sensor data 𝐺 = {𝐺𝑥 , 𝐺𝑦 , 𝐺𝑧 } is gyroscope sensor data the measurement results can be presented into global coordinates as shown in figure 5 with 𝐷𝐶𝑀𝐺 = (𝐷𝐶𝑀𝐵 )𝑇 = [𝐼𝐵 𝐽𝐵 𝐾 𝐵 ]𝑇 . accelerometer can sense earth’s gravity which can become bottom reference. it can be described as follow: 𝐾 𝐵 = −𝐴 (10) magnetometer can sense earth’s magnetic north as reference. it can be described as follow: 𝐼𝐵 = 𝑀 (11) with 𝐾 𝐵 and 𝐼𝐵 are known, 𝐽𝐵 can be calculated by using equation 𝐽𝐵 = 𝐾 𝐵 × 𝐼𝐵 with the rule of right handed coordinate. while 𝑤𝑎 as angular velocity for orientation calculation that affected by accelerometer can be described as 𝑤𝑎 = 𝐾0 𝐵 × 𝑣𝑎 |𝐾0 𝐵| 2 where 𝑣𝑎 = 𝑑𝐾𝐵 𝑑𝑡 = (𝐾𝐴 𝐵−𝐾0 𝐵) 𝑑𝑡 then dθa = wadt = (k0 b × va)dt = (k0 b × (ka b − k0 b) dt⁄ )dt = k0 b × (ka b − k0 b) in order to improve accuracy of attitude calculation, complementary filter can be used. the complementary filter is used to fuse the sensors for getting reliable attitude information. the basic principle of complementary filter is to weight more on the trusted sensor [12]. 𝑑𝜃 = (𝑠𝑎 𝑑𝜃𝑎 + 𝑠𝑔 𝑑𝜃𝑔 ) 𝑠𝑎 + 𝑠𝑔 with 𝑠𝑎 and 𝑠𝑔 are respectively weighted accelerometer and gyroscope sensors. following same logic as accelerometer, we can determine angular rate with magnetometer described as follow 𝑑𝜃𝑚 = 𝑑𝑡 𝑤𝑚 = 𝐼0 𝐵 × (𝐼𝑀 𝐵 − 𝐼0 𝐵 ) to know whether zenith (k) vector using gyroscope in short term condition, it can be described as follow: 𝐾𝐺 𝐵 = 𝐾0 𝐵 + 𝑑𝑡 𝑣 𝐾𝐺 𝐵 = 𝐾0 𝐵 + (𝑑𝜃𝑔 × 𝐾0 𝐵 ) (12) with 𝑑𝜃𝑔 = 𝑤𝑔 𝑑𝑡 and 𝑤𝑔 = 𝐺 because of gyroscope can directly measure angular speed. by using same logic in equation (12), it is known that 𝐼1 𝐵 = 𝐼0 𝐵 + (𝑑𝜃 × 𝐼0 𝐵 ) (13) 𝐽1 𝐵 = 𝐽0 𝐵 + (𝑑𝜃 × 𝐽0 𝐵 ) (14) figure 5. illustration of sensor orientation on global coordinate frame r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 64 2) control algorithm proportional integral derivative (pid) is relatively simple control algorithm that is suitable for controlling simple uav. this control method can be formed by linear calculation which can be handled by 8-bit microcontroller. pid will give feedback control signal from error in order to control the plant in a closedloop system as shown in figure 6. following figure 6, pid consists of three main component calculations of the control signal 𝑢(𝑡) as given in equation (15): 𝑢(𝑡) = 𝐾𝑝𝑒(𝑡) + 𝐾𝑖 ∫ 𝑒(𝑡)𝑑𝑡 + 𝐾𝑑 𝑑𝑒(𝑡) 𝑑𝑡 𝑡 0 (15) where 𝐾𝑝 , 𝐾𝑖 and 𝐾𝑑 describe proportional, integral, derivative gains respectively. each of them has different responses when step input is applied. the response is shown in table 1. ziegler–nichols tuning rule method is used to tune the pid gains. 3) actuator controller servo motors are handling control surface mechanism to generate control motion. servo motor needs a particular signal for generating control motion which is a pulse with 50 hz frequency. most of servo motor is using 1000-2000 microsecond pulse width as depicted in figure 7. therefore, atmega’s interrupt feature is a great help to resolve amount pulse generator problem. b. simulation software simulation software is assigned to generate manipulated virtual environment. this environment can generate a streaming simulated sensory data to controller hardware via middleware. x-plane 10 (x-plane version 10) is used in this work for simulation software. according to figure 8, byte 1 2 3 4 5 6 7 8 9 header type data string 4 byte 4-byte unsigned integer byte 10 11 12 13 14 15 16 17 data 1 data 2 4-byte sign float 4-byte sign float byte ... ... ... ... 38 39 40 41 data ... data 8 4-byte sign float 4-byte sign float figure 9. x-plane 10 udp format data byte 1 2 3 4 5 ... ... ... n+2 n+3 header d a ta – 1 d a ta 2 ... ... ... d a ta n c h e c k su m figure 10. format data protocol uart figure 6. closed-loop pid figure 7. ppm signal table 1. step-input pid control responses increase gain rise time overshoot settling time steady-state error propor-tional decrease increase increase little decrease integral decrease increase increase eliminate derivative alter little decrease decrease alter little figure 8. x-plane 10 unit r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 65 most of unit on x-plane 10 are an imperial unit. therefore, the conversion to metric unit is needed and this is one of tasks assigned to the middleware. xplane 10 uses udp protocol to transfer attitude data. x-plane 10’s format data udp is described in figure 9. x-plane 10’s data transfer rate can be increased up to 100 samples/second. it can be assumed that it can produce simulated sensory data to replace sensory hardware with fastest sampling sensory data which is 50 samples/second from gyroscope and accelerometer. c. middleware system middleware is assigned to provide demands needed by controller hardware which is sensory data and simulator software which is feedback control from generated sensory data. as mentioned in the previous section, the main concern of middleware system is bridging the difference of communication protocols between udp, used in simulation software, and uart, used in controller hardware. the middleware system is designed by using visual studio 2012 express. middleware’s assignment will consists in several parts such as follow:  setting simulator software to send data (in udp) every 10 ms or 100 samples/second to avoid a bottleneck in sensory data.  creating format data with error checking as shown in figure 10, to handle uart inability to detect occurrence of data error. that also prevents glitch data which can obstruct controlling process. header data and checksum will be good solution to prevent data error.  bridging between udp protocol and uart protocol. c# language with framework 4.5 can provide udp and uart communication protocol.  implementing real-time simulation system as well as providing human machine interface (hmi) about condition of controlled plant, as shown in figure 11, which contain: 1. controller mode to set condition of plant such as launch or recovery mode. 2. map and waypoint to show plant position and set waypoint coordinate. 3. pid gain controller to tune pid gain in the real-time experiment. 4. servo monitor to monitor control signal of servo motor. 5. camera controller to show plant’s point of view in launch condition. 6. holder controller for switching to validate mode data sensor in the experiment. 7. sensor monitor for monitoring plant condition in chart form. 8. compass to show rocket’s yaw orientation. 9. artificial horizon to show rocket’s roll and pitch orientation. 10. uart controller for selecting uart port of the microcontroller.  creating sensory data conversion features because some of x-plane 10’s parameters are using imperial unit and sensory hardware are using metric unit, for example: accelerometer: feet second2 to meter second2 to 16 bit digital this is intended to reduce microcontroller’s workload to interpret data from x-plane 10.  creating data buffering for some of parameter simulated sensory data (i.e. angular speed) with time dependence. figure 12 shows how to handle that sensory data. figure 11. designed middleware r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 66 v. experiment the experiment is conducted in few steps to ensure that middleware system can bridge the attitude data from simulator software for control signal computation in controller hardware. each experiment is conducted by 30 times to ensure that each experiment result is consistent. these are experiment steps:  data transfer rate test.  validation simulated attitude data.  comparison of control response. a. data transfer rate test the experiment conducted by transferring data from simulator software to controller hardware via middleware to imitate sampling rate data of sensory hardware. each experiment uses 250 samples data and records time delay between data transmission using controller hardware’s timestamp. every time delay is recorded on controller hardware memory. figure 13 and figure 14 are test sample on gyroscope and accelerometer. accelerometer gives result of 49.94 samples/second average sampling rates with 0.42 samples/second of standard deviation. gyroscope gives result of 49.91 samples/second average sampling rates with 0.46 samples/second of standard deviation. start receive raw sensory data from xplane convert raw sensory data to digital data receive sending signal from scheduler add digital data to temporary variable in buffer no send digital data yes reset temporary variable no end transmission data end yes figure 12. buffering time-dependent data figure 13. accelerometer data transfer rate test figure 14. gyroscope data transfer rate test r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 67 figure 15 and figure 16 are test sample on magnetometer and barometer. magnetometer gives result of 9.97 samples/second average sampling rate with 0.29 samples/second standard deviation. barometer gives result of 9.96 samples/second average sampling rate with 0.27 samples/second standard deviation. b. validation simulated attitude data validation process compares simulated sensor data and real sensory hardware to determine the deviation of sensory system which represents the real experiment in the laboratory. the good system produces responses that have a good fit to the actual system responses on field testing. due to laboratory experiment limitation, plant system is placed on a regulated control system. this is intended to make sensory hardware attitude follows the plant’s attitude on simulator software. following figure 17, the regulated control system will have a role as plant holder to imitate plant’s attitude on simulator software. the regulated control system imitates pitch angle because it is considered has an important role in autonomous take-off, landing and altitude control. the plant holder is depicted in figure 18. figure 15. magnetometer transfer rate test figure 16. barometer data transfer rate test simulated attitude controller processor actuator controller attitude sensory holder plant controller software simulator + reference data figure 17. controller holder plant r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 68 the plant holder uses motorize control mechanism to generate pitching motion on the plant. the pitch motion makes microcontroller recalculate plant’s attitude using sensory hardware. figure 19 shows result sample of this step. on steady-state condition, testing process for pitch angle gives comparison result differs by 0.36 degree average with 0.04 degree standard deviation. c. comparison of control response the comparison of control response is done between a plant with sensory data from simulator software and sensory hardware. rise time and steadystate error become comparison aspect. figure 20 is an example of control response result and performance difference is presented in table 2. according to table 2, average of control responses differs by 0.46s for rise time and 0.53% for steady-state error. figure 18. implemented holder (a) (b) figure 19. sensory data; (a) comparison; (b) deviation r.a. yulnandi et al. / journal of mechatronics, electrical power, and vehicular technology 8 (2017) 60–69 69 vi. conclusions according to the experimental results, it is concluded that the designed hils system satisfies the desired specification and produces responses that have a good fit to the actual system responses. according to desired system specifications, sensory data validation can achieve occurrence error less than 2 and the rise time of control pid between simulated sensory data and sensory hardware has difference less than 1 second and steady-state error of each sensory data less than 2%. the attitude data sampling rate through middleware system suffices the demand of sensory data for controller hardware. acknowledgement this research is funded by ministry of research, technology, and higher education of republic of indonesia via research scholarship of second batch of program menuju doktor sarjana unggul (pmdsu) (328/sp2h/lt/drpm /ix/2016). references [1] h. y. irwanto, “hils of auto take off system: for high speed uav using booster rocket,” in 2016 international seminar on intelligent technology and its applications (isitia), 2016, pp. 373–380. [2] d. joglekar et al., “autopilot design for aerospace vehicle using gui &#x2014; a user friendly approach,” in 2013 annual ieee india conference (indicon), 2013, pp. 1–6. [3] n. p. mahalik and kiseon kim, “a prototype for hardware-inthe-loop simulation of a distributed control architecture,” ieee trans. syst. man, cybern. part c (applications rev., vol. 38, no. 2, pp. 189–200, mar. 2008. [4] h. min et al., “thruster control for micro-satellite attitude and hardware-in-the-loop demonstration,” in 2012 international conference on industrial control and electronics engineering, 2012, pp. 588–591. [5] a. bittar and n. m. f. de oliveira, “hardware-in-the-loop simulation of an attitude control with switching actuators for suav,” in 2013 international conference on unmanned aircraft systems (icuas), 2013, pp. 134–142. [6] a. alsaraj and g. stuffle, “investigation of hardware-in-loop simulation (hils) for guidance system,” in 2015 ieee advanced information technology, electronic and automation control conference (iaeac), 2015, pp. 704–708. [7] j. park et al., “hardware in-the-loop simulation for abs using 32-bit embedded system,” control. autom. syst. (iccas), 2011 11th int. conf., 2011, pp. 575–580. [8] a. nurhafid et al., “modelling and simulation of rkx200 rocket flight dynamics,” in 2013 3rd international conference on instrumentation, communications, information technology and biomedical engineering (icici-bme), 2013, pp. 230–236. [9] in-gyu jang et al., “testing 32-bit embedded system using hardware-in-the-loop-simulation of automatic transmission,” in 2007 international conference on control, automation and systems, 2007, pp. 399–403. [10] y. w. hadi and r. t. bambang, “development of hardwarein-the-loop simultion for rocket guidance system,” in 2015 international conference on electrical engineering and informatics (iceei), 2015, pp. 229–234. [11] b. j. emran et al., “a cascaded approach for quadrotor’s attitude estimation,” procedia technol., vol. 15, pp. 268–277, 2014. [12] m. s. islam et al., “a low cost mems and complementary filter based attitude heading reference system (ahrs) for low speed aircraft,” in 2016 3rd international conference on electrical engineering and information communication technology (iceeict), 2016, pp. 1–5. figure 20. control response comparison table 2. experiment result average standard deviation rise time (s) steady-state error (%) rise time (s) steady-state error (%) simulated sensory 1.89 0.93 0.15 0.11 sensory hardware 1.43 0.4 0.11 0.07 mev journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 2088-6985 / 2087-3379 ©2019 research centre for electrical power an d mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. load characteristic analysis of a double-side internal coreless stator axial flux pmg ketut wirtayasa a, b, *, pudji irasari a, muhammad kasim a, c, puji widiyanto a, muhammad fathul hikmawan a a research centre for electrical power an d mechatronics, in donesian institute of sciences jl. cisitu no. 154d, bandung, 40135, in donesia b department of electrical engineering, national taiwan university of science an d technology, no. 43, section 4, keelun g rd, da’an district, taipei city, 106 , taiwan c school of electrical engineering an d telecommunications, university of new south wales 330 anzac parade, ken sington nsw 2033, australia received 15 march 2019; accepted 29 november; published online 17 december 2019 abstract the main issue of using a permanent magnet in electric machines is the presence of cogging torque. several methods have been introduced to eliminate it, one of which is by employing a coreless stator. in this paper, the load characteristic analysis of the double-side internal coreless stator axial flux permanent magnet generator with the specification of 1 kw, 220 v, 50 hz, 300 rpm and 1 phase is discussed. the purpose is to learn the effect of the load to the generator performance, particularly the output power, efficiency and voltage regulation. the design and analysis are conducted analytically and numerically with two types of simulated loads, pure resistive and resistive-inductive in series. each type of load provides power factor 1 and 0.85 respectively. the simulation results show that when loaded with resistive load, the generator gives a better performance at the output power (1,241 w) and efficiency (91 %), whereas a better voltage regulator (5.86 %) is achieved when it is loaded with impedance. since the difference in the value of each parameter being compared is relatively small, it can be concluded that the generator represents good performance in both loads. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: coreless stator; axial flux permanent magnet generator; load characteristics; resistive load; resistive -inductive in series. i. introduction axial-flux permanent magnet generators (afpmg) offer several benefits, among others, can be made in various alternative topologies [1] and have high power density [2][3]. their application is not only in the electricity generation sector but also in electric vehicles, industrial equipment [4], aircraft, compact engine generator, and battery charging [5]. the stator of afpmg can be built with or without iron core. the latter gives some more advantages since it is lighter than the construction of using core, eliminates cogging torque, easy to manufacture, because it does not need lamination and eliminates magnetic forces to the rotor disc [6] as well as having high efficiency [5][7]. several types of research on the afpm coreless stator have been conducted and most of them are used in wind turbine applications. reference [6] analyzes a double-sided coreless-stator 24 poles and 18 coils afpmg. the best generator performance can be obtained by varying stator thickness and diameter. the highest efficiency is 91.8 % acquired from the combination of the stator thickness and diameter of 8 mm and 150 mm. design and analysis of three rotors and double stators coreless afpmg are observed in [8]. by configuring 12 poles in each rotor and 9 coils in each stator, the generator can produce 1.8 kw and 120 v at 500 rpm. three rotors are used instead of 4 so that reducing the iron loss and the generator weight. a similar pole configuration is found in [9], which is 12 permanent magnet at each of the rotor core (double rotors) and 9 coils in the stator (single stator). the simulation results indicate that the 500 rpm coreless afpmg can generate nearly sinusoidal voltage and * correspon ding author. tel: +62-81223114327 e-mail address: ktwirtayasa@yahoo.co.id https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.17-23&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 18 current waveforms. the amplitude of the waveforms is 100 v and 5 a respectively. in reference [10], design and prototyping of 3 phase, coreless afpmg with two rotors and one stator is investigated. the configuration of 20 poles on the rotors and 18 coils on the stator is employed. the measurement test at 300 rpm yields terminal voltage, output power, and efficiency, respectively are 200 v, 200 w, and 94.2 %. the paper discussed the load characteristics of a 220 v, 1 kw, 50 hz, 300 rpm 1 phase coreless axial flux generator. the simulation is conducted analytically and numerically by employing pure resistive load as well as resistive-inductive loads in series. the aim of this research is studying the effect of the load, mainly on the generator output power, efficiency, and voltage regulation. in addition to the load characteristics, the magnetic flux distribution and air gap flux density simulated using femm 4.2 software will also be presented. ii. materials and methods a. the design feature of the machine the generator topology, dimensions, and main parameters are illustrated in figure 1 and table 1 respectively. the rotor is the rotating part of a generator where the permanent magnets are arranged on the inside (fig. 1a). the stator is the stationary part and the place for the winding (fig. 1b). the stator and rotor are integrated through a shaft to produce electricity. the constructions of the studied double rotor single coreless stator, as well as its dimensions in the axial direction, are shown in fig. 1c and fig. 1d respectively. b. the magnetic field in coreless afpmg the flux paths of the double-sided rotors internal coreless stator afpmg is depicted in fig. 2. the stator is made without core (coreless) and the rotor is made of carbon steel. the flux leave north pole (permanent magnet 1) across stator and air gap to the south pole (permanent magnet 2) and then splits into two equal sections, one of them travels toward south poles of permanent magnet 3, and then passing through the stator as well as air gap to the south pole of permanent magnet 4, as shown by arrow signs. ndfeb has been used as the permanent magnet with br = 1.030 t and the coercive field strength hc = 796 ka/m. moreover, air gap flux density (bmg) and magnetic flux (f) are stated at equation (1) and equation (2) [11][12], table 1. the dimension of the generator parts parameter unit outer rotor disc radius, rro 200 (mm) inner rotor disc radius, rri 115 (mm) winding thickness, tw 4 (mm) rotor yoke thickness, ly 60 (mm) number of turns, n1 340 turn number of poles, 2p 20 poles number of parallel con ductor, aw 2 wire diameter, dw 0.8 (mm) shaft radius, rsh 30 (mm) permanent magnet axial height, hm 40 (mm) inner permanent magnet arc, wpi 28.9 (mm) outer permanent magnet arc, wpo 50.27 (mm) permanent magnet length, lp 85 (mm) air gap length , lg 3 (mm) (a) (b) (c) (d) figure 1. generator dimen sions; (a) rotor; (b) stator and its windin g configuration; (c) three dimen sional coreless afpmg; (d) front view k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 19 𝑩𝐦𝐠 = 𝑩𝐫 𝟏+[ 𝝁𝐫𝐫𝐞𝐜(𝒈+𝟎.𝟓𝒕𝐰) 𝒉𝐦 ]𝒌𝐬𝐚𝐭 (1) 𝜙f = 𝛼i𝐵mg 𝜋 8𝑝 (𝐷ro 2 −𝐷ri 2 ) (2) where br is the remanence flux (t), rrec is the relative permeability of permanent magnet, g is the axial length of the air gap (mm), tw is the winding thickness (mm), hm is the axial height of the permanent magnet (mm), ksat is the saturation factor, αi is the ratio of pole face width to the pole pitch at average radius, dro and dri are the outer and inner diameter of rotor disc (mm), and p is the number of pole pairs. c. single phase equivalent circuit the equation to identify the number of stator turn per phase (n1) and the voltage induced by the rotor when it rotation (ef) is given by [11] 𝑁1 = 𝜀 𝑉1 𝜋√2𝑓𝑘w1𝜙f (3) and 𝐸f = √2𝑓𝑁1 𝑘w1𝜙f (4) where f is the frequency = 50 hz, v1 is the terminal voltage of generator (v),  > 1 for generating mode, kw1 is the winding factor at fundamental harmonic. fig. 3 is the equivalent circuit of afpmg. when the generator runs and connected to a load, the induced current (ia) starts flowing in the stator winding, generates magnetomotive force and interacts with the main field produced by the rotor causing a change in direction and magnitude of the magnetic flux in the air gap. this is usually called an armature reaction. the armature reaction voltage lags the current by 90° and is presented by (-jiadxsd) + (-jiaqxsq). the current iad produces maximum air gap field aligned with the rotor pole (d-axis), and iaq aligned with the q-axis (between poles). the stator coil has resistance r1 and leakage reactance x1. the value of r1 is found with equation (5) 𝑅1 = 𝑁1𝑙1𝑎v 𝑎p 𝑎w𝜎 𝑠a (5) with l1av is the average length of the stator turn (m), ap is the number of the parallel current paths, aw is the number of parallel conductors,  is the electric conductivity of armature conductor (s/m), and sa is the conductor cross section (m2). the sum of the armature or mutual reactance xa and x1 yields synchronous reactance xs, stated with 𝑋sd = 𝑋ad + 𝑋1 (6) 𝑋sq = 𝑋aq + 𝑋1 (7) where d and q represent the dand q-axis respectively. for coreless stator, the leakage reactance is assumed close to 0, so that xsd ≈ xad, and xsq ≈ xaq. furthermore, 𝑋ad = 2𝑚1 𝜇0𝑓( 𝑁1𝑘w1 𝑝 )2 (𝑅ro 2−𝑅ri 2) 𝑔𝑑 ′ 𝑘fd (8) 𝑋aq = 2𝑚1𝜇0 𝑓( 𝑁1𝑘w1 𝑝 )2 (𝑅ro 2−𝑅ri 2) 𝑔𝑞 ′ 𝑘fq (9) where m1 is the phase number, 0 is the permeability of vacuum, g'd and g'q is the dand q-axis equivalent air gap length respectively, kfd and kfq is the form factor in the dand q-axis consecutively, with kfd and kfq equal to 1 for surface configuration of a permanent magnet. the armature current is 𝐼a = 𝐼ad + 𝐼aq (10) if the generator is connected to an electrical load, then figure 2. the geometry and magnetic flux path of double-sided rotors internal coreless stator afpmg figure 3.single phase equivalent circuit of afpmg [11] table 2. the resistive and inductive load cos 𝛟 = 1 cos 𝛟 = 0.85 rl() xl () rl() xl () 400 0 400 247.895 360 0 360 223.105 320 0 320 198.316 280 0 280 173.526 240 0 240 148.737 200 0 200 123.947 160 0 160 99.158 120 0 120 74.368 80 0 80 49.579 40 0 40 24.789 30 18.592 k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 20 𝐼ad = 𝐸f (𝑋sq + 𝑋l ) (𝑋sd + 𝑋l )(𝑋sq+ 𝑋l )+(𝑅1+ 𝑅l ) 2 (11) 𝐼aq = 𝐸f (𝑅1+ 𝑅l ) (𝑋sd + 𝑋l )(𝑋sq + 𝑋l )+(𝑅1+ 𝑅l ) 2 (12) where rl and xl are the load resistance and reactance in  consecutively. d. output power and voltage regulation the terminal voltage (𝑉1) and output power (pout) due to the load impedance (zl) are calculated with 𝑉1 = 𝐼a𝑍l (13) 𝑃out = 𝑚1 𝑉1𝐼a cos 𝜙 (14) 𝜙 = arccos ( 𝐼a𝑅l 𝑉1 ) = arccos ( 𝑅l 𝑍l ) (15) where zl is the load impedance and 𝜙 is the power factor angle. the simulated loads rl and xl that give two different load power factor (pf) 1 and 0.85 are listed in table 2. the percentage change in the output voltage from no-load (vnl) to full-load (vfl) when the generator is loaded by unity, lagging and leading power factor, or also called as voltage regulation vr is obtained using equation (16) [13], 𝑉𝑅 = 𝑉nl− 𝑉fl 𝑉fl 𝑥 100 % (16) generator losses including winding loss p1 (w), eddy current loss pe (w) and rotational loss prot (w) are presented by, ʌ𝑃1 = 𝑚1 𝐼a 2 𝑅1 (17) ʌ𝑃e = 𝜋2 4 𝜎 𝜌 𝑓 2𝑑2𝑚con [ 𝐵mx1 2 + 𝐵mz1 2 ]𝜂d 2 (18) ⧍𝑃rot = ⧍𝑃fr + ⧍𝑃wind (19) where is the specific mass density of the conductor (kg/m3), mcon is mass of the stator conductor without end connection and insulation (kg), d is the diameter of the stator conductor (m), bmx1 and bmz1 are the peak values of tangential and axial components of the magnetic flux density (t) respectively, and ηd is the coefficient of distortion. for the last, the efficiency of the generator is expressed in equation (20) η = pout pout + ∆p = pout pout+ (∆p1+ ∆pe +∆prot) (20) iii. results and discussions a. magnetic field distribution the magnetic field distributions of the generator in no-load and on loaded conditions are shown in fig. 4. for the simulation, the load current correlated with the pf=1 is 5.57 a and for the pf = 0.85 is 6.32 a. at no-load condition (fig. 4a), the magnetic flux is only produced by permanent magnets on the rotor. the maximum value of flux density b (in the box) is the highest (1.049 t) compared to the underloaded condition. when load rl and rl + jxl are applied, the magnetic flux generated by the current flowing in the conductors suppresses the magnetic flux produced by the magnets, which results in a decrease in the maximum b. both simulated loads give the same maximum values of b, which is 1.047 t (fig. 4b & c). in general, all the results in fig. 4 exhibits good magnetic flux distribution on the stator and rotor indicated by the absence of the flux concentration spots. besides, all the maximum flux densities are lower than the saturation point 2.2 t. as previously explained, the armature reaction takes place in the air gap. from figure 5, it can be seen the inverse correlation between the air gap flux density bmg and the load current. the peaks of bmg waves can be observed clearly between the no-load and loaded condition but it appears to coincide between the loaded ones due to a very small difference in value. the peak values of each wave are 0.80896 t, 0.7731 t and 0.76785 t for no-load, pf = 1 and pf = 0.85 consecutively. b. generator performance prediction the calculation results of ia, v1, pout, vr and η, at load rl and rl + jxl are presented in table 3 and table 4. for easy comparison, the parameters in table 3 and table 4 are graphically illustrated as shown in fig. 6 to fig 9. in a synchronous generator using a stator core of any size, the winding resistance is frequently neglected because its value is considered too small compared to the synchronous reactance. however, it is different from a coreless generator. from the calculation, it is obtained xsq = 0.036 and r1 = 2.39 , or in other words, the internal load is more resistive. with two types of the given loads, ia is higher when the load is rl and this causes a higher internal voltage drop, which finally results in lower v1 table 3. calculation results of the electrical parameters at load rl rl () ia (a) v1 (v) pout (w) vr ( %)  (%) 400 < 0° 0.59 236.16 137.78 0.60 74.26 360 < 0° 0.65 234.76 152.88 0.66 76.13 320 < 0° 0.73 234.60 171.71 0.75 78.08 280 < 0° 0.84 234.41 195.82 0.85 80.12 240 < 0° 0.97 234.16 227.82 1.00 82.24 200 < 0° 1.17 233.83 272.31 1.19 84.44 160 < 0° 1.45 233.37 338.39 1.49 86.69 120 < 0° 1.93 232.68 446.79 1.99 88.89 80 < 0° 2.87 231.55 657.29 2.99 90.81 40 < 0° 5.57 229.31 1241.53 5.97 91.11 k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 21 (fig. 6). for having better power factor, the generator with load rl produces better output power (fig. 7) and its efficiency is also slightly higher accordingly (fig. 8), with the best value of 91.11 % at 5.57 a. generator with load zl provides the highest efficiency of 90 % at 4.81 a and then it goes down for saturation. according to eq. (16), vr represents the ratio of voltage drop (from no load to full load) to the no-load voltage. therefore, it should be as low as possible to gain a stable power distribution. it is already mentioned that a higher voltage drop occurs when the load is rl (with referring to fig. 6). consequently, table 4. calculation results of the electrical parameters at load z l zl () ia (a) v1 (v) pout (w) vr ( %)  (%) 400 < 31.79° 0.50 236.16 99.86 0.44 67.76 360 < 31.79° 0.55 235.13 110.85 0.48 69.93 320 < 31.79° 0.62 235.02 124.56 0.55 72.25 280 < 31.79° 0.71 234.88 142.13 0.62 74.70 240 < 31.79° 0.83 234.70 165.48 0.73 77.31 200 < 31.79° 0.99 234.45 198.00 0.87 80.07 160 < 31.79° 1.24 234.12 246.43 1.09 82.96 120 < 31.79° 1.65 233.61 326.22 1.46 85.93 80 < 31.79° 2.46 232.77 482.36 2.19 88.72 40 < 31.79° 4.81 231.11 924.45 4.39 90.05 30 < 31.79° 6.32 226.23 1198.47 5.86 89.38 (a) (b) (c) figure 4. magnetic field distributions under; (a) no-load condition; (b) load r l; (c) load rl + jxl k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 22 the vr is also higher with the maximum value of 5.97 %, and for pf = 0.85 or load zl, vr = 5.86 % (fig. 9). these values meet the requirement, which is below 8 %, according to iec 60364: low voltage electrical installation, part 5-52: selection and erection of electrical equipment wiring systems. figure 5. magnetic flux den sity figure 6. v1 vs ia figure 7. pout vs ia figure 8. η vs ia -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 10 20 30 40 50 60 70 80 90 100 b m g , t tangential length of the air gap, mm no-load pf = 1 pf = 0.85 222 224 226 228 230 232 234 236 238 0 1 2 3 4 5 6 7 v 1 , (v ) ia, (a) pf = 1 pf = 0.85 0 200 400 600 800 1000 1200 1400 0 1 2 3 4 5 6 7 p o u t, ( w ) ia, (a) pf = 1 pf = 0.85 0 10 20 30 40 50 60 70 80 90 100 0 1 2 3 4 5 6 7 η (% ) ia, (a) pf =1 pf = 0.85 k. wirtayasa et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 17–23 23 iv. conclusion load characteristic analysis of the double-side internal coreless stator afpmg has been discussed in this paper. the applied load is resistive and resistiveinductive in series, which gives the power factor of 1 and 0.85 respectively. from the simulation, it is found that when loaded with resistive load, the coreless generator delivers higher armature current but this gives a consequent in higher voltage drop indicated by lower terminal voltage and higher voltage regulation. nevertheless, with a better power factor, the output power and efficiency are higher. it is opposite to the generator that is loaded with impedance. according to the results, it can be concluded that the coreless generator performance is superior in the output power (1,241 w) and efficiency (91 %) with resistive load; on the other hand, the voltage regulation is better (5.86 %) with impedance load. from each parameter being compared, the difference in values is relatively small, so in principle, the generator provides good performance in both loads. acknowledgement the authors would like to thank all the facilities provided by the indonesian institute of sciences (lipi), particularly to the research center for electrical power and mechatronics during the process of making this manuscript. declarations author contribution k. wirtayasa and p. irasari contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] s. s. soe and y. a. oo, “design of the coreless axial-flux doublesided permanent magnet synchronous generator for wind power system,” int. j. sci. eng. technol. res., vol. 3, no. 10, pp. 2047–2051, 2014. [2] s. saint soe and y. a. n. a. oo, “design and implementation of the double-sided axial-flux pmsg with slotted stator by using sizing equation and fea software,” in proceedings of nineteenth theiier international conference, 2015, no. april, pp. 63–69. [3] d. ahmed and a. ahmad, “an optimal design of coreless directdrive axial flux permanent magnet generator for wind turbine,” j. phys. conf. ser., vol. 439, 2013. [4] a. daghigh, h. javadi, and h. torkaman, “improved design of coreless axial flux permanent magnet synchronous generator with low active material cost,” in the 6th international power electronics drive systems an d technologies conference (pedstc2015), 2015, pp. 532–537. [5] s. s. bagesh war, p. v phan d, r. v phan d, p. g. student, an d u. g. student, “design & analysis of axial flux permanent magnet synchronous generator,” int. j. res. tren ds innov., vol. 2, no. 7, pp. 123–129, 2017. [6] m. chirca, s. breban, c. a. oprea, and m. m. radulescu, “analysis of innovative design variations for permanent-magnet generators in micro-wind power applications,” in 2014 international conference on electrical machines (icem), 2014, pp. 385–389. [7] a. o. otuoze, o. o. ogidi, o. o. mohammed, a. a. jimoh, and b. s. olaiya, “sizin g of wind powered axial flux permanent magnet alternator using analytical approach,” niger. j. technol., vol. 35, no. 4, pp. 919–925, 2016. [8] m. r. minaz and m. çelebi, “design and analysis of a new axial flux coreless pmsg with three rotors and double stators,” results ph ys., vol. 7, pp. 183–188, 2017. [9] m. r. minaz and m. çelebi, “analysis and design of an axial-flux coreless permanen t magnet synchronous generator with single stators and double rotors,” int. j. energy appl. technol., vol. 4, no. 1, pp. 7–11, 2017. [10] d. chun g and y. you, “design and performance analysis of coreless axial-flux permanent-magnet generator for small wind turbines,” j. magn., vol. 19, no. 3, pp. 273–281, 2014. [11] j. f. gieras, r. wang, and m. j. kamper, “axial flux permanent magnet brushless machines”, 2nd ed. springer, 2008. [12] s. kim, j. li, d. choi, and y. cho, “design and analysis of axial flux permanent magnet generator for direct-driven wind turbines,” int. j. power syst., vol. 2, pp. 1–6, 2017. [13] t. s. el-hasan, “development of automotive permanent magnet alternator with fully controlled a c / dc converter,” energies, vol. 11, no. 274, pp. 1–28, 2018. figure 9. vr vs ia 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 v r , (% ) ia, (a) pf = 1 pf = 0.85 http://ijsetr.com/uploads/432156ijsetr1290-350.pdf http://ijsetr.com/uploads/432156ijsetr1290-350.pdf http://ijsetr.com/uploads/432156ijsetr1290-350.pdf http://ijsetr.com/uploads/432156ijsetr1290-350.pdf http://www.worldresearchlibrary.org/up_proc/pdf/22-142815096163-69.pdf http://www.worldresearchlibrary.org/up_proc/pdf/22-142815096163-69.pdf http://www.worldresearchlibrary.org/up_proc/pdf/22-142815096163-69.pdf http://www.worldresearchlibrary.org/up_proc/pdf/22-142815096163-69.pdf http://www.worldresearchlibrary.org/up_proc/pdf/22-142815096163-69.pdf https://doi.org/10.1088/1742-6596/439/1/012039 https://doi.org/10.1088/1742-6596/439/1/012039 https://doi.org/10.1088/1742-6596/439/1/012039 https://doi.org/10.1109/pedstc.2015.7093331 https://doi.org/10.1109/pedstc.2015.7093331 https://doi.org/10.1109/pedstc.2015.7093331 https://doi.org/10.1109/pedstc.2015.7093331 https://doi.org/10.1109/pedstc.2015.7093331 https://pdfs.semanticscholar.org/5c83/add99d323b2563e019cbb8e681fd6d1b8673.pdf https://pdfs.semanticscholar.org/5c83/add99d323b2563e019cbb8e681fd6d1b8673.pdf https://pdfs.semanticscholar.org/5c83/add99d323b2563e019cbb8e681fd6d1b8673.pdf https://pdfs.semanticscholar.org/5c83/add99d323b2563e019cbb8e681fd6d1b8673.pdf https://doi.org/10.1109/icelmach.2014.6960209 https://doi.org/10.1109/icelmach.2014.6960209 https://doi.org/10.1109/icelmach.2014.6960209 https://doi.org/10.1109/icelmach.2014.6960209 https://doi.org/10.1109/icelmach.2014.6960209 https://doi.org/10.4314/njt.v35i4.29 https://doi.org/10.4314/njt.v35i4.29 https://doi.org/10.4314/njt.v35i4.29 https://doi.org/10.4314/njt.v35i4.29 https://doi.org/10.1016/j.rinp.2016.10.026 https://doi.org/10.1016/j.rinp.2016.10.026 https://doi.org/10.1016/j.rinp.2016.10.026 https://www.semanticscholar.org/paper/analysis-and-design-of-an-axial-flux-coreless-with-minaz-%c3%87elebi/d59219d7f391c0437220bbad53a78981e703a23c https://www.semanticscholar.org/paper/analysis-and-design-of-an-axial-flux-coreless-with-minaz-%c3%87elebi/d59219d7f391c0437220bbad53a78981e703a23c https://www.semanticscholar.org/paper/analysis-and-design-of-an-axial-flux-coreless-with-minaz-%c3%87elebi/d59219d7f391c0437220bbad53a78981e703a23c https://www.semanticscholar.org/paper/analysis-and-design-of-an-axial-flux-coreless-with-minaz-%c3%87elebi/d59219d7f391c0437220bbad53a78981e703a23c https://doi.org/10.4283/jmag.2014.19.3.273 https://doi.org/10.4283/jmag.2014.19.3.273 https://doi.org/10.4283/jmag.2014.19.3.273 https://link.springer.com/book/10.1007/1-4020-2720-6 https://link.springer.com/book/10.1007/1-4020-2720-6 https://www.iaras.org/iaras/journals/caijps/design-and-analysis-of-axial-flux-permanent-magnet-generator-for-direct-driven-wind-turbines https://www.iaras.org/iaras/journals/caijps/design-and-analysis-of-axial-flux-permanent-magnet-generator-for-direct-driven-wind-turbines https://www.iaras.org/iaras/journals/caijps/design-and-analysis-of-axial-flux-permanent-magnet-generator-for-direct-driven-wind-turbines https://doi.org/10.3390/en11020274 https://doi.org/10.3390/en11020274 https://doi.org/10.3390/en11020274 mev journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.49-59 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015 (sinta 2). the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines: atp-emtp computational approach fri murdiya *, febrizal, cecilia stevany, havel alindo sano, firdaus department of electrical engineering, faculty of engineering, universitas riau jl. h.r subrantas km 12,5 kampus binawidya panam, pekanbaru, 28293, indonesia received 14 january 2019; accepted 15 november 2019 abstract this simulation study presents the effect of lightning strikes on the performance of arresters at 150 kv overhead lines. lightning strikes have several parameters that affect the performance of line arresters (la), namely lightning charge, and impulse energy. the simulation was attempted by the injection of a direct strike to the ground wire with the peak voltage of 10 mv. the peak voltage was varied in terms of wavefront time (tf) and the duration of lightning impulses (tau). in order to calculate current, charge and impulse energy of la from various variations of tf and tau, the trapezoidal numerical integration method is used. the current and impulse energy arising due to direct strikes and various variations of tf and tau will be compared for each phase so that the influence of tf and tau can be obtained from the performance of the la and the current charge and impulse energy values are still within the limits of the ieee c62.11 standard. the installation of la and the position of arresters affected the peak voltage of lightning on the phase line when lightning struck it. the line arresters provide a drop in the peak voltage of lightning in phase lines. by installing line arresters in each tower, it will reduce the peak voltage of lightning on the phase line more significantly than the standalone line arrester. it is shown that the line arresters have to install at least six towers to reduce the peak voltage in the phase lines. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: lightning impulse; line arrester; peak voltage; impulse energy; placement of arrester. i. introduction overhead lines for 70 kv, 150 kv and 275 kv, which stretch along the island of sumatra, are very susceptible to the disruption caused by lightning strike. this is proven by the lightning activity in sumatra island, which includes the high category. this happens because indonesia is located in the humid tropics which results in very high thunderstorm days compared to other regions (100200 days of thunder per year). based on the calculation using ieee flash software as shown in figure 1, the back flashover rate (bfor) and shielding failure flashover rate (sffor) are directly proportional to the ground flash density (gfd) for the 150 kv overhead lines in sumatra. with gfd of 9-13 flash/km2/year, the 150 kv overhead lines in sumatra are often hit by the lightning strikes. the data show that from 2011 to 2014, the phase lines were struck by lightning as many as 305 times as shown in figure 2. the recorded failures of the 150 kv overhead lines in central sumatra from 2011 to 2014 occurred throughout the year. this failure was recorded as a failure due to lightning. these data also show that the central sumatra has a high lightning density which is a threat and disruption to the distribution of electricity. the data in figure 1 and figure 2 indicates that the 150 kv overhead lines in central sumatra need to be protected according to the safety standard. high-voltage transmission poles are tall objects and are subject to lightning strikes. it is not only the shielding failure caused by lightning struck that should be calculated, but the back flashover needs to also be estimated. the efforts that have been attempted by the electric company in sumatra to reduce the outages caused by lightning strikes include checking and resetting the grounding rod at * corresponding author. hp: +62 812 8881 6276 e-mail address: frimurdiya@eng.unri.ac.id https://dx.doi.org/10.14203/j.mev.2019.v10.49-59 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.49-59 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.49-59&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 50 least under 5 ohms, checking and repairing the ground static wire clamps, as well as the installations of transmission lightning arrester (tla), lightning protection termination early streamer emission (ese), and static wire insulated ground (i-gsw) for areas that are often struck by lightning. another effort was also carried out by installing jet stream arcquenching lightning protection gap. external ground wires contribute to reduce flashover rate. those efforts are done by [1][2][3][4][5][6][7][8]. the recommendation for back flashover rate improvement has been proposed by [9] using multi chamber insulator arresters (mcia) to substitute the string insulators. from the improvement efforts carried out by the electric company in sumatra, there are some interesting things to be evaluated further, such as whether, the installed tla is related to the characteristics of the lightning impulses and their effects to decrease the lightning peak voltage hence improving the 150 kv lines performances. in this manuscript, the simulations were carried out by means of atp-emtp software. the impulse generator model uses the heidler model which is an impulse current function model and is widely used as a model of lightning. equation (1) and equation (2) are momentary current equations that calculate lightning currents in this model [10][11][12][13]. this heidler model is given in figure 3. 𝑖(𝑡) = 𝐼0 𝜂 ⋅ [ 𝑡 𝜏1 ] [ 𝑡 𝜏1 ] 𝑛 +1 ⋅ 𝑒 [ −𝑡 𝜏2 ] (1) 𝜂 = 𝑒 [−[ 𝜏1 𝜏2 ][ 𝜂𝜏2 𝜏1 ] 1 𝑛 ] (2) where 𝐼0 is lightning peak current (ka), 𝜏1 is current rising time constant, 𝜏2 is current dropping time constant, and 𝜂 is current crest factor. the tla model of 150 kv overhead lines is shown in figure 4. this model has also been derived from ieee standards [14][15][16]. this model will be used in the simulation with the atp-emtp software. the figure 1. bfor and sffor for 150 kv in sumatra source: electric company in sumatra figure 2. the number of the outage of the 150 kv overhead lines caused by lightning struck 16 16 21 2 23 30 29 8 17 15 6 10 26 21 23 22 0 5 10 15 20 25 30 35 jan-mar apr-jun jul-sep oct-dec 2011 2012 2013 2014 figure 3. lightning current model f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 51 pinceti and giannettoni model is a simplified model of the ieee w.g 3.4.11 standard. this model eliminates the capacitance c because of its negligible effect. the two parallel resistances with inductance are replaced by one r resistance (about 1 mω) between the input terminals. the non-linear resistor characteristics 𝐴𝑜 and 𝐴1 are identical to the ieee w. g 3.4.11 model. the 𝐿𝑜 and 𝐿1 parameters of this simplified surge arrester model are calculated from the following equation (3) and equation (4) [17][18]. 𝐿1 = 1 4 ⋅ 𝑉𝑟1 𝑇2⁄ −𝑉𝑟8 20⁄ 𝑉𝑟8 20⁄ ⋅ 𝑉𝑛 (3) 𝐿0 = 1 12 ⋅ 𝑉𝑟1 𝑇2⁄ −𝑉𝑟8 20⁄ 𝑉𝑟8 20⁄ ⋅ 𝑉𝑛 (4) where 𝑉𝑛 is arrester rated voltage, 𝑉𝑟1 𝑇2⁄ is impulse voltage with a waveform of 1,2/5 µs, 𝑉𝑟8 20⁄ is impulse voltage with waveform 8/20 µs. the values of nonlinear resistance a0 and a1 are taken from the data of zno arrester presented in table 1. by using equation (3) and equation (4), the values of 𝐿1 is 0.002448 mh and 𝐿0 is 0.000816 mh. the values of a0 and a1, vref is twice of residual voltage for the current of 10 ka and waveform of 8/20 μs. the transmission tower is modelled for 150 kv with four parameters illustrated in figure 5. one of the well-known models is the multistory model designed by masaru ishii. the multistory tower model consists of a line of parameters distributed with parallel rl circuits and has been recommended by japanese standards for designing/coordinating insulation against lightning. this model is widely used for lightning wave analysis in japan [13][19][20]. the velocity of propagation is 300 m/s. the recommended surge impedance value from the tower model above can be seen in table 2. the values of r and l every section on the tower are defined as in equation (5) and equation (6) as follows: 𝑅𝑖 = δ𝑅𝑖 𝑥𝑖 (5) 𝐿𝑖 = 2𝜏𝑅𝑖 (6) where i = 1,2,3, and 4 for every section of the tower, tower height h, x1 is the distance of ground wire (gw) to phase line 1, x2 is the distance of phase line 2 to phase line 1, x3 is the distance of phase line 3 to phase line 2, and x4 is the distance of phase line 3 to ground. the formula of δ𝑅𝑖 is determined by equation (4) and table 2. recommended value of lightning parameters system voltage lighting current tower height/ geometry (m) surge imp. (ω ) footing res. (ω ) (kv) (ka) h x1 x2 x3 zt1 zt4 rf 1100 200 107 12.5 18.5 18.5 130 90 10 500 150 79.5 7.5 14.5 14.5 220 150 10 275 100 52.0 9.0 7.6 7.6 220 150 10 154 (110) 60 45.8 6.2 4.3 4.3 220 150 10 77 (66) 30, 40 28.0 3.5 4.0 3.5 220 150 10-20 (a) (b) figure 5. the well-known models: (a) 150 kv tower and (b) multi-storey tower for atp-emtp model rp l0 l1 a0 a1 figure 4. pinceti and giannettoni model table 1. data of arrester mov i (a) u (v) a0 a1 10 271,250 0 100 298,530 238,390 1,000 325,500 263,500 2,000 337,280 277,140 4,000 348,750 286,750 6,000 352,780 290,780 8,000 362,390 296,360 10,000 368,280 300,390 12,000 373,860 302,250 14,000 381,610 306,280 16,000 387,500 308,140 18,000 397,110 310,000 20,000 407,030 311,860 f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 52 equation (5) where zt1 and zt4 are data from table 1 for system voltage of 154 kv/110 kv and time of traveling wave on the tower: 𝜏 = ℎ 𝑐0⁄ , the attenuation constant: and propagation velocity: 𝑐0 = 300 𝑚 𝜇𝑠⁄ . δ𝑅1 = δ𝑅2 = δ𝑅3 = 2𝑍𝑡𝑙 ℎ−𝑥4 𝑙𝑛 ( 1 𝛼1 ) (7) δ𝑅4 = 2𝑍𝑡𝑙 ℎ−𝑥4 𝑙𝑛 ( 1 𝛼1 ) (8) transmission lines in japan use a vertical twincircuit configuration with two ground wires and 6 phase wires. this configuration model is used for the transmission line model on emtp called the frequency-dependent line model of the emtp. however, the influence of distributed-line models with a fixed propagation velocity, more attenuation, and surge impedance is explained in emtp which is often used for transient overvoltage simulations [21]. the frequency-dependent effect of a tower used in the simulation is a combination of the frequencydependent tower impedance with the semlyen or marti line model in emtp [22][23][24][25][26]. the current charge is the area of lightning or integral current with time. this current charge (q) is formulated in equation (9), where i is the lightning current strength in ka and t is a time in seconds. 𝑄 = ∫ 𝑖 𝑑𝑡 (c) (9) integral quadratic current (e) is impulse energy which is a mechanical effect, and lightning heat can be formulated in equation (10), 𝐸 = ∫ 𝑖2𝑡 𝑑𝑡 (j) (10) by following the simulation rules above, the effects of lightning impulse characteristics and transmission lines arrester (tla) on the design of tla laying in 150 kv overhead lines in sumatra were carried out. the number of tla used needs to be proven by simulations to determine the effectiveness of tla installation on 150 kv overhead lines in sumatra. ii. research methodology analysis of lightning strikes on arrester work at 150 kv overhead lines in this study was carried out using the atp (alternative transient program). the simulation process was carried out in several stages, namely: field data collection, transmission line parameter calculation, modelling all channel parameters into atp-emtp, analyzing current charge and impulse energy in arresters in each phase and analyzing the installation of arresters in each transmission tower. the data retrieval was carried out by collecting equipment data, tower data, power transformer data, arrester data used at the substation and lines, and the components needed for the modelling process. the conductor data used in this study are divided into two: shield wires and phase wires. shield wires are made of the galvanized steel wire with a crosssectional area of 55 mm2, and the sag length is 4,576 m. phase conductor is made of zebra acsr with a cross-sectional area of 428 mm2, rmax resistance is 0.0397 ohm/km, xmax reactance is 0.272 ohm/km, lmax inductance is 0.433 mh/km and cmax capacitance is 6.645 nf/km. sag length is 5.4 m. the tower configuration is shown in figure 6. shield wires and phase wires are tabulated in table 3. figure 6. tower configurations table 3. the positions of shield wires and phase wires conductor no. operating phase-phase [kv] phase angle [0] function phase coordinates x [m] y [m] 1 shield -1.5 35.5 2 shield 1.5 35.5 3 150 0 r -2.05 30.73 4 150 240 s -2.125 26.03 5 150 120 t -2.2 21.33 6 150 0 r' 2.05 30.73 7 150 240 s' 2.125 26.03 8 150 120 t' 2.2 21.33 span (average) = 300 m surge impedance = 139 ohm f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 53 by entering tower configuration data into equations (5-8), the parameters for the tower replacement circuit were obtained in the atp-emtp software. lines phases were modelled with lcc and the configuration of the circuit of sixline phases and two ground wires. the power transformer used was 150 kv rms with a frequency of 50 hz. arrester was used by the model in figure 4. the simulation method looked at the effect of lightning wave front (tf) and lightning wave duration (tau) on lightning charge and lightning energy compared to the ieee c62.11 standard. the peak voltage of the impulse generator (heidler model) was 10 mv. after overvoltage on the tower, a simulation was carried out to see the effect of tla installation on the 150 kv transmission line. the back flash over model was also created with an automatical switch in microsecond order, for example, number 6 in figure 7. according to table 2, the tower ground resistance is 10 ohm. the number of tla and tla positions is the objective of this research. the model used in the simulation is given in figure 7. iii. results and discussions the variation of tf of the lightning impulse modelled at atm-emtp is shown in figure 8. the tf value imputed on the hiedler impulse generator model is 1.2, 2.4, 3.6, 4.8 µs. next, the wavefront start value and tau value are set at 0.1 and 50 µs. after the tf and data parameters are set, the impulse current flows through arresters in phase a because the isolator flashover process occurs in phase a. the characteristics of lightning impulse currents through arresters in phase a for variations of tf are given in figure 9. by using the trapezoidal numerical method, the current charge and impulse energy values can be solved by using current impulse data flowing in arrester a with a variation of tf. for the comparison of the current charge, the change in tf is still within the arrester resistance limit, which is in the range of 3.5 c. however, the impulse energy values that occur in arresters on phase a have exceeded the energy resistance limit of the arrester, which is 11 kj. the value of the current charge and impulse energy with variations of tf is given in figure 10 and figure 11. it figure 7. 150 kv overhead lines model: (1) substation; (2) lightning arrester; (3) lcc/lines; (4) multistory tower; (5) power generator; 6. impulse generator; (7) footing resistance (rf); (8) switch for back flashover f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 54 shows that the variation tf of the lightning impulse influences the current charge and impulse energy values. current and impulse energy values are proportional to tf. by keeping the peak voltage of the impulse 10 mv and varying the tf values, the impulse energy received by the arrester is greater than the standard value while the charge values are still below the standard. impulse energy that exceeds this standard could result in a shorter lifetime of the arrester. in order to find out the effect of changes in tau value, this simulation was carried out by varying the tau values of 50, 70, 90, 110 and 130 µs. as for the values of tsta and tf are fixed, which is 0.1 and 1.2 µs. the value of the variation of the lightning impulse is shown in figure 12 and figure 13. by injecting lightning impulses into a 150 kv overhead lines model, this will cause arresters in phase a to work because the arresters are passed by the current after a flashover event of the insulator in phase a. the current charge and impulse energy can be solved using current data flowing in the arrester in phase a. these values are given in figure 14 and figure 15. it is shown that the tau value is proportional to the current charge. if the tau values exceed the 70 µs, the arrester will exceed the limit value (shown in yellow line). however, the value also affects the impulse energy value, which exceeds the standard value of arresters according to ieee c62.11. the values of tau could affect the values of the charge and impulse energy that exceeds the standard. it is shown that tau can influence the arrester performance where the lifetime of arrester will be shorter than the variation of tf. in order to figure out the effect of arrester performance, the installation locations of arresters are varied in this study. figure 16 shows a simulation of a series of a lightning strike that grabs the ground figure 8. lightning impulse with tf variations figure 9. current waves passing through arresters in phase a to variations of tf figure 10. comparison of current charge values to variations of tf figure 11. comparison of impulse energy values with tf variations f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 55 wire and propagates throughout the transmission lines. the carry out model is the insulator on tower number 4 during the flashover event and it causes an increase of voltage on the phase wire. the tf, tsta and tau values in this simulation are 1.2, 3, and 90 ms, respectively. the simulation results that were run on a series of a lightning strike on ground wires without mounting arresters can be seen in figure 16. the values of the peak voltage of phase wire are 6.5078 mv, 7.7113 mv, 8.6198 mv, 10 mv, 8.8588 mv, and 8.3243 mv for tower numbers 1 to 6, respectively. this simulation also examines the effect of arrester performance in various arrester installation locations. figure 17 shows a simulation of a series of the lightning strike with arresters placed on tower 1. the arrester on tower 1 has a voltage drop of 89.05 % with a voltage level of 0.7124 mv. meanwhile, towers 2 to 6 did not experience significant decreases of peak voltage, with the values of 10.99 %, 0.54 %, 0 %, 0.81 %, and 0.8 %, respectively. the peak voltage of phase wires for towers 2 to 6 are 6.9173 mv, 8.5731 mv, 10 mv, 8.7873 mv, and 8.2579 mv, respectively. figure 18 shows the simulation result with the placement of tla on towers 1 and 5. the peak lightning voltage on the phase wires in each tower is different. the highest to figure 14. comparison of current charge values to tau variations figure 15. comparison of impulse energy values to tau variations figure 12. lightning impulse with tau variations figure 13. current waves through arrester in phase a after lightning currents are injected with variations of tau f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 56 the lowest peak voltage is found in towers 4, 3, 2, 6, 5, and 1. the most significant decrease in peak voltage on phase wires is found between towers 1 and 5. the peak voltage drop on phase wires from towers 1 to 6 are 89.67 %, 11 %, 0.52 %, 0 %, 84.61 %, 83.49 %, respectively, while the recorded peak voltage was 0.7113 mv, 6.9167 mv, 8.5746 mv, 10 mv, 1.3636 mv, 1.3746 mv, respectively. moreover, the simulation results for the installation of arresters in towers 1, 2 and 6 can be seen in figure 19. from the graph above, figure 16. simulation result of the output of the lightning strike circuit without arrester figure 17. simulation results show a series of lightning strikes on transmission lines with arresters placed on tower 1 figure 18. simulation result of a lightning strike on transmission lines with arresters placed on towers 1 and 5 f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 57 the data obtained for peak voltage on phase wires in towers 1 to 6 include 0.5153 mv, 0.8021 mv, 7.6114 mv, 10 mv, 7.613 mv, 0.8971 mv, respectively and the percentages of reduction of peak voltage are 92.08 %, 89.68 %, 11.69 %, 0 %, 14.04 %, 89.22 % for towers 1 to 6, respectively. the simulation results for the installation of arresters in towers 1, 3, 4 and 5 can be seen in figure 20. from the graph above, the data are as follows: the peak voltages of lightning on phase wire are 0.5471 mv (decreased 91.59 %), 0.8519 mv (decreased 89.04 %), 1.284 mv (decreased 85.1 %), 10 mv (decreased 0 %), 1.3615 mv (decreased 84.63 %), and 1.3811 mv (decreased 83.41 %) for towers 1 to 6, respectively. figure 21 is a simulation result with the placement of arresters in towers 1, 2, 3, 4, 5, and 6. figure 19. simulation result of a lightning strike on transmission lines with arresters placed on towers 1, 2 and 6 figure 20. simulation result of a lightning strike on transmission lines with arresters placed on towers 1, 3, 4 and 5 figure 21. simulation result of a lightning strike on transmission lines with arresters placed on towers 1, 2, 3, 4, 5 and 6 f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 58 the lightning peak voltages on phase wire are 0.4679 mv, 0.5674 mv, 1.2248 mv, 10 mv, 1,2322 mv, and 0.6219 mv for towers 1 to 6, respectively. the voltage drop values are as follows: 92.81 %, 92.64 %, 85.79 %, 0 %, 86.09 %, and 92.53 % for towers 1 to 6, respectively. in addition, the location of lightning strikes on overhead lines does not have a significant effect on travelling waves with the theory of wave reflection and waves transmitted on the system. however, the location of the lightning strike still influences the overvoltage in the substation by changing the distance of the travelling wave towards the substation [27]. then, the simulation results also show that the installation of arresters for all phases in several towers can reduce the overvoltage in the tower. this is in a good agreement with [28][29]. however, for economic and maintenance reasons, the installation of arresters should be on a tower that often gets lightning strikes. iv. conclusion based on the simulation and data analysis that has been done, some conclusions can be drawn: the variations of the wave front time duration (tf) and strike duration (tau) on lightning impulses affect the current and integral currents that occur in arresters. tsta variations in lightning impulses do not affect the current charge and impulse energy. tf is proportional to current charge and impulse energy. the small tau leads to the current toward zero faster. lightning strikes of 10 mv on the ground wire without mounting arresters resulted in the increases of voltage on the phase wires on tower 1 until 6 were 6.5078 mv, 7.7113 mv, 8.6198 mv, 10 mv (tower had flashover event), 8.8588 mv and 8.3243 mv, respectively. after the installation of arresters in each tower for phase wires, the subsequent decrease of peak voltage on tower 1 until 6 were 0.4679 mv (92.81 %), 0.5674 mv (92.64 %), 1.2248 mv (85.79 %), 10 mv (0 %), 1.2322 mv (86.09 %) and 0.6219 mv (92.53 %), respectively. protection of the transmission line to reduce overvoltage in phase wires by installing arresters in each tower is better than installing the standing alone arrester or without installing any arresters. acknowledgement we thank all those who have supported this research. declarations author contribution f. murdiya contributed as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] a. borghetti et al., “ lightning protection of a multi-circuit hvmv overhead line,” electric power systems research, vol. 180, pages 106-119, available online 3 december 2019. [2] a. rahiminejad and b. vahidi, “lpm-based shielding performance analysis of high-voltage substations against direct lightning strokes,” ieee trans. power deliv., 32, 2218– 2227, 2017. [3] r. zoro, g. k. atmajaya and b. denov, "lightning protection system for high voltage transmission line in indonesia," 2nd international conference on high voltage engineering and power systems (ichveps), denpasar, bali, indonesia, pp. 1-5, 2019. [4] j. wang et al., “research and application of jet stream arcquenching lightning protection gap (jsalpg) for transmission lines,” ieee trans. dielectr. electr. insul., 22, 782–788, 2015. [5] f. m. gatta et al., “tower grounding improvement versus line surge arresters: comparison of remedial measures for highbfor subtransmission lines,” ieee trans. ind. appl., 51, 4952– 4960, 2015. [6] s. mladen and banjanin,”line arresters application in lightning protection of high voltage substations with nonstandard configuration,” electric power components and systems, 45:11, 1173-1181, 2017. [7] mladen s et al., “lightning protection of overhead transmission lines using external ground wires,” electric power systems research, volume 127, pages 206-212, 2015. [8] m. s. savic and a. m. savic, “substation lightning performance estimation due to strikes into connected overhead lines,” ieee trans. power deliv., 30, 1752–1760, 2015. [9] k. t. m. u. hemapala, o. v. g. swathika, and k. p. r. d. s. k. dharmadasa, “techno-economic feasibility of lighting protection of overhead transmission line with multi-chamber insulator arrestors”, development engineering, volume 3, pages 100-116, 2018. [10] a. s. ghoniem, “effective elimination factors to the generated lightning flashover in high voltage transmission network,” international journal on electrical engineering and informatics, volume 9, number 3, september 2017. [11] o. e. gouda, a. z. el dein, and g. m. amer, "parameters affecting the back flashover across the overhead transmission line insulator caused by lightning." proceedings of the 14th international middle east power systems conference (mepcon’10), cairo university, vol. 111, 2010. [12] s. h. taheri, a. gholami, and m. mirzaei, "study on the behavior of polluted insulators under lightning impulse stress." electric power components and systems, 37.12, 1321-1333, 2009. [13] n. zawani et al., “modelling of 132 kv overhead transmission lines by using atp/ emtp for shielding failure pattern recognition,” procedia engineering, vol. 53, 278–287, 2013. [14] m. a. abd-allah, m. n. ali, and a. said, "towards an accurate modeling of frequency-dependent wind farm components under transient conditions,” wseas transactions on power systems, volume 9, art. #40, pp. 395-407, 2014. [15] p. pinceti and m. giannettoni, "a simplified model for zinc oxide surge arresters," in ieee transactions on power delivery, vol. 14, no. 2, pp. 393-398, april 1999. [16] f. fernandes, r. diaz, ”metal-oxide surge arrester model for fast transient simulations,” ipst conference, 2001. [17] d. lovrić, s. vujević, and t. modrić, ‘comparison of different metal oxide surge arrester models’, int. j. emerg. sci, 4 december, pp. 545–554, 2011. https://doi.org/10.1016/j.epsr.2019.106119,(http:/www.sciencedirect.com/science/article/pii/s0378779619304389) https://doi.org/10.1016/j.epsr.2019.106119,(http:/www.sciencedirect.com/science/article/pii/s0378779619304389) https://doi.org/10.1016/j.epsr.2019.106119,(http:/www.sciencedirect.com/science/article/pii/s0378779619304389) https://doi.org/10.1109/tpwrd.2016.2616518 https://doi.org/10.1109/tpwrd.2016.2616518 https://doi.org/10.1109/tpwrd.2016.2616518 https://doi.org/10.1109/tpwrd.2016.2616518 https://doi.org/10.1109/ichveps47643.2019.9011069 https://doi.org/10.1109/ichveps47643.2019.9011069 https://doi.org/10.1109/ichveps47643.2019.9011069 https://doi.org/10.1109/ichveps47643.2019.9011069 https://doi.org/10.1109/ichveps47643.2019.9011069 https://doi.org/10.1109/tdei.2015.7076776 https://doi.org/10.1109/tdei.2015.7076776 https://doi.org/10.1109/tdei.2015.7076776 https://doi.org/10.1109/tia.2015.2448613 https://doi.org/10.1109/tia.2015.2448613 https://doi.org/10.1109/tia.2015.2448613 https://doi.org/10.1109/tia.2015.2448613 https://doi.org/10.1080/15325008.2017.1334101 https://doi.org/10.1080/15325008.2017.1334101 https://doi.org/10.1080/15325008.2017.1334101 https://doi.org/10.1080/15325008.2017.1334101 https://doi.org/10.1016/j.epsr.2015.06.001 https://doi.org/10.1016/j.epsr.2015.06.001 https://doi.org/10.1016/j.epsr.2015.06.001 https://doi.org/10.1109/tpwrd.2015.2404771 https://doi.org/10.1109/tpwrd.2015.2404771 https://doi.org/10.1109/tpwrd.2015.2404771 https://doi.org/10.1016/j.deveng.2018.05.003 https://doi.org/10.1016/j.deveng.2018.05.003 https://doi.org/10.1016/j.deveng.2018.05.003 https://doi.org/10.1016/j.deveng.2018.05.003 https://doi.org/10.1016/j.deveng.2018.05.003 https://doi.org/10.15676/ijeei.2017.9.3.3 https://doi.org/10.15676/ijeei.2017.9.3.3 https://doi.org/10.15676/ijeei.2017.9.3.3 https://doi.org/10.15676/ijeei.2017.9.3.3 https://www.researchgate.net/publication/272479568 https://www.researchgate.net/publication/272479568 https://www.researchgate.net/publication/272479568 https://www.researchgate.net/publication/272479568 https://www.researchgate.net/publication/272479568 https://doi.org/10.1109/ceidp.2008.4772848 https://doi.org/10.1109/ceidp.2008.4772848 https://doi.org/10.1109/ceidp.2008.4772848 https://doi.org/10.1016/j.proeng.2013.02.037 https://doi.org/10.1016/j.proeng.2013.02.037 https://doi.org/10.1016/j.proeng.2013.02.037 http://www.wseas.org/multimedia/journals/power/2014/a085716-250.pdf http://www.wseas.org/multimedia/journals/power/2014/a085716-250.pdf http://www.wseas.org/multimedia/journals/power/2014/a085716-250.pdf http://www.wseas.org/multimedia/journals/power/2014/a085716-250.pdf https://doi.org/10.1109/61.754079 https://doi.org/10.1109/61.754079 https://doi.org/10.1109/61.754079 https://www.ipstconf.org/papers/proc_ipst2001/01ipst056.pdf https://www.ipstconf.org/papers/proc_ipst2001/01ipst056.pdf http://journaldatabase.info/articles/comparison_different_metal_oxide_surge.html http://journaldatabase.info/articles/comparison_different_metal_oxide_surge.html http://journaldatabase.info/articles/comparison_different_metal_oxide_surge.html f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 59 [18] l. shoubin et al., “applicability analysis of simulation model of metal oxide arrester and experimental study,” advances in intelligent systems research (aisr), volume 151, 2018. [19] m. ishii et al., "multistory transmission tower model for lightning surge analysis," in ieee transactions on power delivery, vol. 6, no. 3, pp. 1327-1335, july, 1991. [20] h. w. dommel, emtp theory book: b.p.a., aug. 1986. [21] a. semlyen and a. dabuleanu, "fast and accurate switching transient calculations on transmission lines with ground return using recursive convolutions," in ieee transactions on power apparatus and systems, vol. 94, no. 2, pp. 561-571, march 1975. [22] j. r. marti, “accurate modeling of frequency-dependent transmission lines in electromagnetic transient simulations,” ieee trans. power app. syst., vol. pas-101, no. 1, p. 147, 1982. [23] n. nagaoka, “development of frequency-dependent tower model,” trans. iee japan, vol. 111-b, p. 51, 1991. [24] j. v. g. r. rao, k. s.kalyani, and k. r. charan, ”optimal surge arrester placement for extra high voltage substation”, international journal of engineering and advanced technology (ijeat), volume-8 issue-6, august 2019. [25] n. h. n hassan et al., ”analysis of discharge energy on surge arrester configurations in 132 kv double circuit transmission lines,” measurement, volume 139, pages 103-111, 2019. [26] j. r. martí and a. tavighi, "frequency-dependent multiconductor transmission line model with collocated voltage and current propagation," in ieee transactions on power delivery, vol. 33, no. 1, pp. 71-81, feb., 2018. [27] m. i. jambak et al., “analysis of transmission lightning arrester locations using tflash,” telkomika, volume 14, number 4, 2016. [28] q. xia, “surge arrester placement for long transmission line and substation,” master theses, arizona state university, may 2018. [29] j. he et al., “statistical analysis on lightning performance of transmission lines in several regions of china,” ieee trans. power deliv., 30, 1543–1551, 2015. https://doi.org/10.2991/cmsa-18.2018.14 https://doi.org/10.2991/cmsa-18.2018.14 https://doi.org/10.2991/cmsa-18.2018.14 https://doi.org/10.1109/61.85882 https://doi.org/10.1109/61.85882 https://doi.org/10.1109/61.85882 http://www.dee.ufrj.br/ipst/emtptb.pdf https://doi.org/10.1109/t-pas.1975.31884 https://doi.org/10.1109/t-pas.1975.31884 https://doi.org/10.1109/t-pas.1975.31884 https://doi.org/10.1109/t-pas.1975.31884 https://doi.org/10.1109/mper.1982.5519686 https://doi.org/10.1109/mper.1982.5519686 https://doi.org/10.1109/mper.1982.5519686 https://doi.org/10.1541/ieejpes1990.111.1_51 https://doi.org/10.1541/ieejpes1990.111.1_51 https://doi.org/10.35940/ijeat.f9232.088619 https://doi.org/10.35940/ijeat.f9232.088619 https://doi.org/10.35940/ijeat.f9232.088619 https://doi.org/10.35940/ijeat.f9232.088619 https://doi.org/10.1016/j.measurement.2019.02.088 https://doi.org/10.1016/j.measurement.2019.02.088 https://doi.org/10.1016/j.measurement.2019.02.088 https://doi.org/10.1109/tpwrd.2017.2691343 https://doi.org/10.1109/tpwrd.2017.2691343 https://doi.org/10.1109/tpwrd.2017.2691343 https://doi.org/10.1109/tpwrd.2017.2691343 https://doi.org/10.12928/telkomnika.v14i4.3792 https://doi.org/10.12928/telkomnika.v14i4.3792 https://repository.asu.edu/items/49328 https://repository.asu.edu/items/49328 https://repository.asu.edu/items/49328 https://doi.org/10.1109/tpwrd.2014.2363122 https://doi.org/10.1109/tpwrd.2014.2363122 https://doi.org/10.1109/tpwrd.2014.2363122 f. murdiya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 49-59 60 this page intentionally left blank mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.11-21 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller bayu prasetyo a, *, faiz syaikhoni aziz a, anik nur handayani a, ari priharta a, adi izhar bin che ani b a electrical engineering department, universitas negeri malang jalan semarang no 05, malang, 65145, indonesia b faculty of electrical engineering, universiti teknologi mara (uitm) kolej amira uitm puncak alam road, selangor, 42300, malaysia received 28 november 2019; accepted 30 april 2020; published online 30 july 2020 abstract the increasing need for electrical energy requires suppliers to innovate in developing electric distribution systems that are better in terms of quality and affordability. in its development, it is necessary to have a control that can combine the electricity network from renewable energy and the main network through voltage back-up or synchronization automatically. the purpose of this research is to create an innovative lux and current analysis on a lab-scale smart grid system using a fuzzy logic controller to control the main network, solar panel network and generator network to supply each other with lab-scale electrical energy. in the control, mamdani fuzzy logic controller method is used as the basis for determining the smart grid system control problem solving by adjusting the current conditions on the main network and the light intensity conditions on the ldr sensor. current conditions are classified in three conditions namely safe, warning, and trip. meanwhile, the light intensity conditions are classified into three conditions namely dark, cloudy and bright. from the test results, the utility grid (pln) is at active conditions when the load current is 0.4 a (safe) and light intensity is 1,167 lux (dark). then the pln + pv condition is active when the load current is 1.37 (warning) and the light intensity is 8,680 lux (bright). finally, the generator condition is active when the load current is 1.6 (trip) and the light intensity is 8,680 (bright). based on the test results, it is known that the system can work to determine which source is more efficient based on the parameters obtained. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: fuzzy logic; smart grid; lux and current; lab-scale. i. introduction the increase in electricity used by consumers makes electricity suppliers begin to innovate in managing electricity supply so that it remains distributed to consumers with good quality. at the consumer level, many systems have been developed to save or maintain electric power stability, such as back-up voltage systems, the utilization of kwh exim, smart home, building energy management system (bems), etc. then at the distributor level, they have also begun to develop many systems to maintain the stability and the availability of electric power for consumers, for example installing bank capacitors and smart grid systems. the smart grid system is a modern electricity network infrastructure to increase reliability, security, and efficiency also to integrate with renewable energy sources through automatic control [1][2][3]. it is able to integrate the actions of all users, from power generation to consumers with the aim of being more efficient, sustainable, economical and safer electricity supply [4]. it is also considered as the future of electricity grid that can manage the production, transmission and distribution of electricity with modern technology [5][6][7] to solve many problems of the current electricity grid system. many smart grid designs have been developed to keep the supply quality maintained and some designs have also been designed to be environmentally friendly by scheduling the use of energy supplies from steam power plants and renewable energy sources such as solar panels, water generators, wind generators and so forth. this has begun to be adopted by several countries * corresponding author. tel: +62-838-3393-3230 e-mail address: bayoe.30015@gmail.com https://dx.doi.org/10.14203/j.mev.2020.v11.11-21 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.11-21 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.11-21&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 12 including countries that have large renewable energy potential. in some developing countries, the smart grid system is classified as new technology and is still being developed. the system starts with the idea of an advanced measurement infrastructure to improve demand management and energy efficiency, building reliable network protection, and assuring the network can improve itself in the event of a disruption or natural disaster [2]. in its development, the smart grid system is often integrated with fuzzy logic as a method of decision making. fuzzy logic was introduced as a model for handling inaccurate, inconsistent, and inexact information [8][9]. a fuzzy set is an object class with a continuum of membership values. fuzzy logic uses the rule base to change the value of input crips to the corresponding output crips [10]. by using fuzzy logic controller, we can effectively model complex non-linear systems [10] broadly speaking, there are three steps to model the system using a fuzzy logic controller, namely fuzzification, inference engine, and defuzzification. fuzzification is used to change from crisp input to fuzzy variables so that it can be processed. the next step is the inference engine which is fuzzy input reasoning and giving rules. then, the final step is defuzzification which converts the fuzzy output from the inference engine results to crips value based on membership function [10]. in this study, mamdani fuzzy logic controller [11] is combined in the lab-scale smart grid system with lux and current as input parameters. some studies use mamdani fuzzy as a system method developer, for example, mamdani fuzzy inference approach to assess ecological security [12] and rule-based fuzzy control methods for resetting the static pressure [13], and in this study mamdani fuzzy logic controller is used to control smart grid. previously, several research projects that are related to the smart grid system had been carried out. the project such as smart grid system on a smart home by controlling the load based on the soc battery condition where the battery input was obtained from a hybrid solar panel system with a wind generator [14]. the purpose of this project was to manage the burden so that it can reduce the use of conventional energy that is not needed. the research resulted in battery discharge off and load off when there is no grid energy if soc ≤ 30 %. then the engine load will be off when 30 % < soc < 70 %. finally, all loads will light up if the value of soc ≥ 70 %. in other similar studies, there have been several system design developments by giving some switching to the renewable energy system output so that it can be controlled. the study was conducted by combining distributed power supply, wind generators, and solar panels in an ac bus with the parameters used in the control system is the soc battery [15]. from the research results, it was known that the system besides being able to produce highquality electricity, it could also transfer electrical energy quickly to steady-state with a smooth system flow change mechanism [15]. referring to the researches, it can be concluded that the mechanism of changing energy sources is the key to produce good electricity by utilizing conventional energy and renewable energy. this source change mechanism is adopted in the development of lux and current analysis on a labscale smart grid system using the mamdani fuzzy logic controller. the difference between this research and the previous research is in the control parameters used. previous studies referred to soc batteries, while this research focuses more on environmental and load current conditions. control of energy sources is regulated to maximize the potential for renewable energy and increase the efficiency of using conventional sources. the purpose of this research is to create an intelligent control system that can determine the most efficient energy source to be used based on the parameters of the intensity of light and current at the lab-scale. this system should be able to monitor the value of light intensity in the environment around the system and the current conditions of the utility grid. ii. materials and methods in general, the smart lab-scale smart grid system has a system whose working principle determines the source for the load based on current conditions and the intensity of the light on the prototype. there are three sources with utility grid (pln) or sources from main suppliers as the main sources. then, the second source is a 100 wp solar panel with an ac current limit after the inverter of 2 a and the third source is a genset with a current capacity of 6 a. figure 1 illustrates the lab-scale smart grid system flowchart to get a better understanding of how this system works. the development of a lab-scale smart grid system is divided into two constructions namely hardware construction and fuzzy construction. the hardware construction focuses on the hardware used in the development while the fuzzy construction focuses on the formation of fuzzy rules as a basis for solving control problems based on light and current intensity parameters. a. hardware construction the hardware construction lab-scale smart grid system is the development of magnetic coordination props using contactors. these visual aids are then developed by using a microcontroller and several control components to connect the energy source. in general, hardware construction can be seen in figure 2 then the workmanship system of the lab-scale smart grid system can be seen in figure 3, and the components used in developing the lab-scale smart grid system are available in table 1. the lab grid-scale design of the smart grid system has two main blocks namely the control block and the data computing block. the control block consists of a magnetic control display device in the form of a case that is developed by adding arduino mega and a four channels relay as a conversion from dc control to ac control. then, the data computation block b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 13 consists of computers that have arduino ide and plq-dax installed as a parameter reader. the design of the lab-scale smart grid system and the control block design can be seen in figure 4 and figure 5. b. fuzzy construction this lab-scale smart grid system is controlled by a microcontroller in the form of arduino mega with decision making determined by the mamdani fuzzy logic method. problem-solving with the fuzzy logic controller has three steps namely fuzzification, inference, and defuzzification with the following explanations. 1) fuzzification fuzzification is a process of changing the input from explicit forms into more linguistic forms. in fuzzification, all data is presented in the form of fuzzy sets using the membership function. in the development of the lab-scale smart grid system, there are two input parameters namely current and light intensity. each input data will be grouped or clustered by k-means technique. during the clustering process, turns out that in the light intensity data group, the three conditions have a wide range so system normalization is needed for analysis. the results of light intensity data groups division can be seen in table 2 and the results of the current data groups distribution are in table 3. based on the results of clustering, the membership function is generated. it is used to map input data points into membership values. mapping the lab-scale smart grid system membership table 1. components in the lab-scale smart grid system no. component total specification 1. magnetic contactor 3 pieces 14 pin model: s-n25/coil380 vac 2. 1-phase mcb 1 piece 6 amperes 3. 1-phase mcb 2 pieces 2 amperes 4. arduino mega 1 piece 5. thermal overload relay 3 pieces th-n12kp 6. relay 4 channels 1 piece 7. push button no 4 pieces 8. push button nc 2 pieces 9. indicator lamp 4 pieces 5 w/220 vac 10. emergency button 1 piece 11. ldr sensor 1 piece ldr 12. current sensor 1 piece acs712 13. terminal block 14 pieces tb2503 3 pole 25 a table 2. division of light intensity data groups before and after normalization condition division of data groups (lux) preliminary data data after normalization dark 0 – 107 0 – 3,931 cloudy 10.8 – 5,752 3,543 – 6,997 bright 1,075 – 10,527 6,708 – 10,527 start input parameters: current and lux current parameter: secure current parameter: warning current parameter: trip lux parameter: cloudy lux parameter dark? lux parameter: dark? lux parameter: dark? lux parameter: cloudy lux parameter: cloudy output: pln output: pln output: genset output: pln+pv output: pln+pv output: pln+pv output: pln+pv output: genset output: pln finish y y y nn y nn y y n n figure 1. lab-scale smart grid system flowchart b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 14 function is done by displaying the clustering result using labview software which can be seen in figure 6 and figure 7. after the membership function is known, the next step is to determine the degree of membership or 𝜇[𝑥]. the two inputs use three types of membership functions, namely linear up, trapezoidal and linear down so that in finding the value 𝜇[𝑥] there are three different ways according figure 2. smart grid lab-scale construction figure 3. smart grid lab-scale maintenance b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 15 to the location of the input. the linear up membership function has the characteristics of a straight line starting from the lowest domain value (𝜇[𝑥] = 0) on the left side, then moving right towards the domain with a greater degree of membership value. the membership function used in the next input is the trapezoid. mapping inputs into degrees of membership are represented by an isosceles trapezoidal form which can be interpreted as having several main points of input having a degree of membership equal to one. finally, the membership function used is linear down. the linear descending membership function has the characteristic of a straight line starting from the highest domain value (𝜇[𝑥] = 1) on the left side, then moving right towards the domain with a smaller degree of membership. the form of the three membership functions can be seen in figure 8. in linear rise, determining the value of 𝜇[𝑥] is by using equation (1). in linear down, determining the value of 𝜇[𝑥] is by using equation (2). in membership of the trapezoid function, determining the value of 𝜇[𝑥] is by using equation (3). after the grouping process or clustering is completed, the fuzzification stages or the stage of changing from input data to fuzzy input forms, the next stage is inference. 𝑓(𝑥) = � 0, 𝑥 ≤ 𝑎 (𝑥 − 𝑎) (𝑏 − 𝑎)⁄ , 𝑎 < 𝑥 < 𝑏 1, 𝑥 ≥ 𝑏 (1) 𝑓(𝑥) = � 0, 𝑥 ≥ 𝑏 (𝑏 − 𝑥) (𝑏 − 𝑎)⁄ , 𝑎 < 𝑥 < 𝑏 1, 𝑥 ≤ 𝑎 (2) 𝑓(𝑥) = � 0, 𝑥 ≤ 𝑎 ∥ 𝑥 ≥ 𝑑 (𝑥 − 𝑎) (𝑏 − 𝑎)⁄ , 𝑎 < 𝑥 < 𝑏 (𝑑 − 𝑥) (𝑑 − 𝑐)⁄ , 𝑐 < 𝑥 < 𝑑 1, 𝑏 ≤ 𝑥 ≤ 𝑐 (3) 2) inference engine using mamdani model the inference engine stage is the reasoning stage for the fuzzy input obtained from the fuzzification process and sent into the knowledge base that contains fuzzy rules to produce fuzzy output. the inference engine process is carried out using the mamdani model. the model is often referred to as the min-max model [11]. the mamdani fuzzy rules are stated in the form equation (4), if (x is a) and (y is b) then (z is c) (4) where the values of a, b, and c are fuzzy shapes, while x, y, z are crips values. the application of the functional implication in the mamdani model uses the min function, while the composition between rules uses the max function to produce a new fuzzy set. in this stage, there is a process that must be carried out by beginning to create a knowledge base/truth table containing rules. the knowledge base of smart grid using lac system can be seen in table 4. based on table 4, if-then rules can be determined a number of 9 conditions which can be seen in table 5. seeing that the inference stage is a stage that combines two degrees of membership, it is necessary to have fuzzy set operations that will produce fire strength or α -predicate values in each rule. in the inference process using the mamdani model, the value of the degree of membership in each rule is applied with the minimum implication function (min) of the linguistic value using the conjunction rule (∩). the formula used to determine α -predicates with minimum implied functions can be seen in equation (5). table 3. division of flow data groups tim condition division of data groups (a) 1 secure 0 – 1.3 2 warning 1 – 1.7 3 trip 1.4 – 2 ac control dc control ct power source sensor control block data computing block pln pv genset ldr acs712 load figure 4. design of lab-scale smart grid system table 4. smart grid system knowledge base lux parameter current parameter secure warning trip dark pln genset genset cloudy pln pln + pv genset bright pln pln + pv pln + pv table 5. fuzzy rules for the inference process no. rule 1. if ‘ light intensity’ is ‘ dark’ and ‘ current’ is ‘ secure’ then ‘ contact’ is ‘ pln’ 2. if ‘ light intensity’ is ‘ dark’ and ‘ current’ is ‘ warning’ then ‘ contact’ is ‘ genset’ 3. if ‘ light intensity’ is ‘ dark’ and ‘ current’ is ‘ trip’ then ‘ contact’ is ‘ genset’ 4. if ‘ light intensity’ is ‘ cloudy’ and ‘ current’ is ‘ secure’ then ‘ contact’ is ‘ pln’ 5. if ‘ light intensity’ is ‘ cloudy’ and ‘ current’ is ‘ warning’ then ‘ contact’ is ‘ pln+ panel’ 6. if ‘ light intensity’ is ‘ cloudy’ and ‘ current’ is ‘ trip’ then ‘ contact’ is ‘ genset’ 7. if ‘ light intensity’ is ‘ bright’ and ‘ current’ is ‘ secure’ then ‘ contact’ is ‘ pln’ 8. if ‘ light intensity’ is ‘ bright’ and ‘ current’ is ‘ warning’ then ‘ contact’ is ‘ pln+panel’ 9. if ‘ light intensity’ is ‘ bright’ and ‘ current’ is ‘ trip’ then ‘ contact’ is ‘ pln+panel’ b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 16 𝛼 − 𝑝𝑟𝑒𝑑𝑖𝑐𝑎𝑡𝑒 = 𝜇(𝑥1) ∩ 𝜇(𝑥2) = min{𝜇(𝑥1), 𝜇(𝑥2)} (5) where 𝑥1 is the degree of membership of set 1 and 𝑥2 is the degree of membership of set 2. then after applying the min function, an output linguistic value is obtained which is then composed by the max function with the disjunction (∪) rule. the formula used to determine the new μ value from the rule composition can be seen in equation (6). 𝜇𝑡ℎ𝑒𝑛 = {𝛼 − 𝑝𝑟𝑒𝑑𝑖𝑐𝑎𝑡𝑒 𝜇(𝑥1)} ∪ {𝛼 − 𝑝𝑟𝑒𝑑𝑖𝑐𝑎𝑡𝑒 𝜇(𝑥2)} = max{𝛼 − 𝑝𝑟𝑒𝑑𝑖𝑐𝑎𝑡𝑒 𝜇(𝑥1), 𝛼 − 𝑝𝑟𝑒𝑑𝑖𝑐𝑎𝑡𝑒 𝜇(𝑥2)} (6) where α-predicate 𝜇(𝑥1) is output linguistic value 1 and α-predicate 𝜇(𝑥2) is output linguistic value 2. in the lab-scale smart grid system research, there are several rules that are analysed with the mamdani model inference engine with the results are presented in table 6. after the α-predicate value is known, it will produce a degree of fuzzy output membership. from this degree of fuzzy membership, a single fuzzy set will be produced which will be table 6. fuzzy inference results using the mamdani model rule inference min max output for l1 1252 dan c 0.78 obtained 2 fuzzy input data, g(1), a(1) 1 if li is dark (1) and c is secure (1) then output contact is pln 1 1 pln for l1 1928 dan c 1.11 obtained 3 fuzzy input data, g(1), a(0.633), mt (0.367) 1 if li is dark (1) and c is secure (0,633) then output contact is pln 0.633 0.633 pln 2 if li is dark (1) and c is warning (0,367) then output contact is genset 0.633 0.367 genset 4 if li is cloudy (0,915) and c is secure(0,233) then output contact is pln 0.233 0.085 genset for l1 4049 dan c 1.23 obtained 3 fuzzy input data, g(1), a(0.233), mt (0.767) 4 if li is cloudy (1) and c is secure (0,233) then output contact is pln 0.233 0.233 pln 5 if li is cloudy (1) and c is warning (0,767) then output contact is pln+pv 0.767 0.767 pln+pv for l1 8725 dan c 1.85 obtained 2 fuzzy input data, c (1), t (1) 9 if li is bright(1) and c is trip (1) then output contact is pln+pv 1 1 pln+pv for l1 9476 dan c 0.82 obtained 2 fuzzy input data, c (1), a (1) 7 if li is bright(1) and c is secure (1) then output contact is pln+pv 1 1 pln pc and arduino communication 4 channel relay digital pin to contactor a1 control block arduino digital pin to 4 channel relay in pin ac control dc control figure 5. lab-scale smart grid system full block design figure 6. membership function of lux b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 17 used at the defuzzification stage. the degree of fuzzy output membership in the lab-scale smart grid system can be seen in figure 9. 3) defuzzification in the inference engine stage, the fuzzy output is data with linguistic value types. meanwhile, data is needed in numerical form in the control system, therefore, it is necessary to change the value of the data from fuzzy output to numeric form or called the defuzzification stage. the defuzzification process in the mamdani model uses the formula according to equation (7) as follow. 𝑍∗ = ∑𝑧.𝜇(𝑧) ∑𝜇(𝑧) (7) where 𝑍∗ is defuzzification value, ∑𝑧. 𝜇(𝑧) is moment for all region of the rule composition, and ∑𝜇(𝑧) is membership value. based on min and max values in the inference process using the mamdani model, it can be seen the value of 𝑍∗ with the results shown in table 7. figure 7. membership function of current figure 8. membership function: (a) linear up; (b) linear down; and (c) trapezoid table 7. deffuzification results inference min max defuzzification if li is dark (1) and c is secure (1) then output contact is pln 1 1 0.75 if li is dark (1) and c is secure (0.633) then output contact is pln 0.633 0.633 0.97 if li is dark (1) and c is warning (0.367) then output contact is genset 0.633 0.367 if li is dark (1) and c is secure (0.2) then output contact is pln 0.2 0.2 1.38 if li is dark (1) and c is warning (0.8) then output contact is genset 0.8 0.8 if li is dark (1) and c is secure (0.233) then output contact is pln 0.233 0.233 1.34 if li is dark (1) and c is warning (0.767) then output contact is genset 0.767 0.767 if li is dark (1) and c is secure (0.233) then output contact is pln 0.233 0.233 1.34 if li is dark (1) and c is warning (0.767) then output contact is genset 0.767 0.767 if li is dark (0.085) and c is secure (0.915) then output contact is pln 0.085 0.233 1.12 if li is dark (0.085) and c is warning (0.767) then output contact is genset 0.085 0.767 if li is cloudy (0.915) and c is secure(0.233) then output contact is pln 0.233 0.085 if li is cloudy (0.915) and c is warning (0.767) then output contact is pln+pv 0.767 if li is cloudy (1) and c is secure (0.233) then output contact is pln 0.233 0.233 1.15 if li is cloudy (1) and c is warning (0.767) then output contact is pln+pv 0.7676 0.767 if li is bright(1) and c is trip (1) then output contact is pln+pv 1 1 1.35 if li is bright(1) and c is secure (1) then output contact is pln+pv 1 1 0.75 b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 18 iii. results and discussions the lab-scale smart grid system is particularly a load source control system that will be used based on the lac or lux and current parameters by utilizing the ldr as a light intensity information finder and the acs712 sensor as a current data finder for further processing on arduino nano with the fuzzy logic controller method. in the development process, there are two stages of testing to know the results or performance of the developed system, namely sensor testing and overall system testing. a. sensor test result sensor testing is performed to determine the performance of the sensors used to produce accurate data. this test is carried out to ensure the accuracy of the input data which will later be processed on arduino nano. this test does not use the fuzzy logic method as a controller and only uses ordinary programming to bring up input parameter values. 1) current sensor test the first test is the acs 712 sensor to measure ac current. this test is done by comparing the reading of the acs 712 current sensor with the amperemeter. the results of the reading show the current values that have approached the measurement results of the amperemeter. the results of reading the current sensor and measuring instrument can be seen in figure 10. it can be concluded that the acs712 sensor can be used as a current parameter actuator because the reading value is close to the actual current. based on the measurement, the error value of the current sensor is 3.57 %. 2) light intensity sensor test light intensity was detected by ldr for 4 hours 33 minutes by taking data every 30 seconds using readings with plq-dax software. the experiment started at 10:22 am until 2:55 pm. the ldr trial results can be seen in figure 11. from the test results, it is known that the lux value that is read by the ldr is unstable or too volatile with a relatively short interval of time. then, the repair is done at 12.00 pm. after that, it is retested and the reading of the light intensity improves even though it tends to fall due to cloudy. it can be concluded that the two sensors can be used to obtain data from the parameters of current and light intensity. b. system test in system testing, a program containing lab-scale smart grid system control with the mamdani fuzzy logic controller method is uploaded to the arduino board that has been connected to sensors and figure 10. comparison of acs712 and amperemeter measurements figure 9. membership degree in fuzzy output b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 19 control components. then, the system is tested by changing the values of the current parameters and light intensity. replacement of the current parameter value is done by adding or reducing the load while changing the light intensity parameter by replacing the light source with several other light sources that have different light intensities. the preparation in testing can be seen in figure 12. the test was carried out with three conditions representing the three outputs namely pln (utility grid), pln + pv, and genset. in the experiment, the voltage source is not entered into the system and only the control of the smart grid system is tested with the result presented in figure 13. the first test is to make the control conditions using pln so that the input conditions are low light intensity and low load. then, the system is run and the results of monitoring on the acquisition of microsoft excel with the help of plq-dax. test results with conditions of low light intensity and low load indicate that the red indicator light and contactor 1 are on. this indicates that the source used is pln in accordance with the desired output conditions. then, the second experiment is carried out by changing the parameter values so that the output becomes pln + pv by increasing current and light intensity. the test results note that contactors 1 and 2 are active than red lights and yellow lights are also on. this indicates that the sources used are pln and photovoltaic synchronization. finally, the third test is done by modifying the input thus the output that will appear is the genset by raising the current to near the upper limit and lowering the value of the light intensity. the results of the test turn out to be appropriate, namely contactor 3 is active and the green indicator light is on. the first, second, and third test results can be seen in figure 14. figure 11. ldr test result data figure 12. smart grid system testing using lac b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 20 iv. conclusion lux and current analysis on a lab-scale smart grid system using the mamdani fuzzy logic controller can determine the most efficient energy source by considering the conditions of light and current intensity parameters. this system utilizes renewable energy when the energy source from the sun is detected by an ldr sensor, especially when there is an increase in current demand from the installed load. this working principle increases the potential for utilizing renewable energy sources by prioritizing the supply of electrical energy from re rather than increasing the demand for electrical energy from the utility grid. this smart grid system development can also reduce the use of electrical energy from the utility grid because there is a control system that regulates the power flow scheme when the load on the utility system approaches the highest capacity of the utility grid. lac-based smart grid can be developed by adding several supporting components in accordance with voltage back-up and synchronization rules so synchronization can be better. with a few adjustments, this system can be implemented on a large scale electricity network system. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. figure 13. testing of smart grid system using lac figure 14. first testing (left), second testing (middle), third testing (right) results b. prasetyo et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 11-21 21 references [1] v.c. gungor, b. lu, and g.p. hancke, “opportunities and challenges of wireless sensor networks in smart grid,” ieee trans. ind. electron., 2010. [2] f. rahimi and a. ipakchi, “demand response as a market resource under the smart grid paradigm,” ieee transactions on smart grid., 2010. [3] c. cecati et al., “smart operation of wind turbines and diesel generators according to economic criteria,” ieee trans. ind. electron., 2011. [4] m.l. tuballa and m.l. abundo, “a review of the development of smart grid technologies,” renewable and sustainable energy reviews., 2016. [5] n. anku, j. abayatcye, and s. oguah, “smart grid: an assessment of opportunities and challenges in its deployment in the ghana power system,” in 2013 ieee pes innovative smart grid technologies conference, isgt 2013, 2013. [6] h. hou et al., “a brief analysis on differences of risk assessment between smart grid and traditional power grid,” in proceedings 2011 4th international symposium on knowledge acquisition and modeling, kam 2011, 2011. [7] l. peng and g.s. yan, “clean energy grid-connected technology based on smart grid,” in energy procedia, 2011. [8] l.a. zadeh, “fuzzy logic,” in computational complexity: theory, techniques, and applications, 2013. [9] p.v.s. reddy, “generalized fuzzy logic for incomplete information,” in ieee international conference on fuzzy systems, 2013. [10] l. mahardika et al., “optimization of light tracker movement using fuzzy logic control,” in 2018 international conference on information and communications technology, icoiact 2018, 2018. [11] i. iancu, “a mamdani type fuzzy logic controller,” in fuzzy logic controls, concepts, theories and applications, 2012. [12] j. sun et al., “a mamdani fuzzy inference approach for assessing ecological security in the pearl river delta urban agglomeration, china,” ecol. indic., 2018. [13] x. li et al., “rule-based fuzzy control method for static pressure reset using improved mamdani model in vav systems,” j. build. eng., 2019. [14] a. tascikaraoglu et al., “smart grid-ready concept of a smart home prototype: a demonstration project in ytu,” in international conference on power engineering, energy and electrical drives, 2013. [15] w. liu et al., “smart micro-grid system with wind/pv/battery,” in energy procedia, 2018. https://doi.org/10.1109/tie.2009.2039455 https://doi.org/10.1109/tie.2009.2039455 https://doi.org/10.1109/tie.2009.2039455 https://doi.org/10.1109/tsg.2010.2045906 https://doi.org/10.1109/tsg.2010.2045906 https://doi.org/10.1109/tsg.2010.2045906 https://doi.org/10.1109/tie.2011.2106100 https://doi.org/10.1109/tie.2011.2106100 https://doi.org/10.1109/tie.2011.2106100 https://doi.org/10.1016/j.rser.2016.01.011 https://doi.org/10.1016/j.rser.2016.01.011 https://doi.org/10.1016/j.rser.2016.01.011 https://doi.org/10.1109/isgt.2013.6497800 https://doi.org/10.1109/isgt.2013.6497800 https://doi.org/10.1109/isgt.2013.6497800 https://doi.org/10.1109/isgt.2013.6497800 https://doi.org/10.1109/kam.2011.57 https://doi.org/10.1109/kam.2011.57 https://doi.org/10.1109/kam.2011.57 https://doi.org/10.1109/kam.2011.57 https://doi.org/10.1016/j.egypro.2011.10.030 https://doi.org/10.1016/j.egypro.2011.10.030 http://doi.org/10.1007/978-1-4614-1800-9_73 http://doi.org/10.1007/978-1-4614-1800-9_73 https://doi.org/10.1109/fuzz-ieee.2013.6622305 https://doi.org/10.1109/fuzz-ieee.2013.6622305 https://doi.org/10.1109/fuzz-ieee.2013.6622305 https://doi.org/10.1109/icoiact.2018.8350695 https://doi.org/10.1109/icoiact.2018.8350695 https://doi.org/10.1109/icoiact.2018.8350695 https://doi.org/10.1109/icoiact.2018.8350695 https://doi.org/10.5772/36321 https://doi.org/10.5772/36321 https://doi.org/10.1016/j.ecolind.2018.07.011 https://doi.org/10.1016/j.ecolind.2018.07.011 https://doi.org/10.1016/j.ecolind.2018.07.011 https://doi.org/10.1016/j.jobe.2018.12.005 https://doi.org/10.1016/j.jobe.2018.12.005 https://doi.org/10.1016/j.jobe.2018.12.005 https://doi.org/10.1109/powereng.2013.6635850 https://doi.org/10.1109/powereng.2013.6635850 https://doi.org/10.1109/powereng.2013.6635850 https://doi.org/10.1109/powereng.2013.6635850 https://doi.org/10.1016/j.egypro.2018.09.171 https://doi.org/10.1016/j.egypro.2018.09.171 introduction ii. materials and methods a. hardware construction b. fuzzy construction 1) fuzzification 2) inference engine using mamdani model 3) defuzzification iii. results and discussions a. sensor test result 1) current sensor test 2) light intensity sensor test b. system test iv. conclusion declarations author contribution funding statement conflict of interest additional information references mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.ph p/mev/login need a username/password? go to registration at: http://mevjournal.com/index.ph p/mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 editor-in-chief dr. haznan abimanyu dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia asscociate editor (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 © 2019 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, five papers are published with the authors diversity came from indonesia, australia, and united kingdom. the papers come from multidisciplinary topics including mechatronics, electrical power, and mechanics. they may be classified as follows. three papers fall in electrical power topic. the first paper presents simulation study for the effect of lightning strikes on the performance of arresters at 150 kv overhead lines. the second paper proposes a comprehensive guide and comparison surrounding the technologies supporting smart grid implementation especially on communication application. the third paper has the aim to identify the impact of synthetic textiles on earthing system performance through numerical analysis with the state-of-the-art software package. one paper is related to mechatronics which address the different exoskeleton designs and presents a working prototype of a surface electromyography (emg) controlled exoskeleton to enhance the strength of the lower leg. one paper deals with mechanical topic i.e. three axis deviation analysis of cnc milling machine. since the first volume, our journal provides discretion in financial term by waiving the article processing charge. we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2019 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 ii list of contents the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines: atp-emtp computational approach fri murdiya, febrizal, cecilia stevany, havel alindo sano, firdaus ................................................... 49-59 design and development of the semg-based exoskeleton strength enhancer for the legs mikecon cenit, vaibhav gandhi .................................................................................................................. 61-71 smart grid communication applications: measurement equipment and networks architecture for data and energy flow tinton dwi atmaja, dian andriani, rudi darussalam ........................................................................... 73-84 safety assessment of high voltage substation earthing systems with synthetic geotextile membrane mostafa nazih................................................................................................................................................... 85-91 three axis deviation analysis of cnc milling machine dalmasius ganjar subagio, ridwan arief subekti, hendri maja saputra, ahmad rajani, kadek heri sanjaya ...................................................................................................................................... 93-101 complete articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 10, issue 2, 2019 abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. fri murdiya, febrizal, cecilia stevany, havel alindo sano, firdaus (department of electrical engineering, faculty of engineering, universitas riau, indonesia ) the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines: atp-emtp computational approach journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 2, p. 49-59, 21 ill, 3 tab, 29 ref. this simulation study presents the effect of lightning strikes on the performance of arresters at 150 kv overhead lines. lightning strikes have several parameters that affect the performance of line arresters (la), namely lightning charge, and impulse energy. the simulation was attempted by injection of a direct strike to the ground wire with the peak voltage of 10 mv. the peak voltage was varied in terms of wavefront time (tf) and the duration of lightning impulses (tau). in order to calculate current, charge and impulse energy of la from various variations of tf and tau, the trapezoidal numerical integration method is used. the current and impulse energy arising due to direct strikes and various variations of tf and tau will be compared for each phase so that the influence of tf and tau can be obtained from the performance of the la and the current charge and impulse energy values are still within the limits of the ieee c62.11 standard. the installation of la and the position of arresters affected the peak voltage of lightning on the phase line when lightning struck it. the line arresters provide a drop in the peak voltage of lightning in phase lines. by installing line arresters in each tower, it will reduce the peak voltage of lightning on the phase line more significantly than the standalone line arrester. it is shown that the line arresters have to install at least six towers to reduce the peak voltage in the phase lines. (author) keywords: lightning impulse; line arrester; peak voltage; impulse energy; placement of arrester. mikecon cenit, vaibhav gandhi (department of design engineering and mathematics, middlesex university london, united kingdom) design and development of the semg-based exoskeleton strength enhancer for the legs journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 2, p.61-71, 12 ill, 0 tab, 73 ref. this paper reviews the different exoskeleton designs and presents a working prototype of a surface electromyography (emg) controlled exoskeleton to enhance the strength of the lower leg. the computer aided design (cad) model of the exoskeleton is designed, 3d printed with respect to the golden ratio of human anthropometry, and tested structurally. the exoskeleton control system is designed on the labview national instrument platform and embedded in myrio. surface emg sensors (semg) and flex sensors are used coherently to create different state filters for the emg, human body posture and control for the mechanical exoskeleton actuation. the myrio is used to process semg signals and send control signals to the exoskeleton. thus, the complete exoskeleton system consists of semg as primary sensor and flex sensor as secondary sensor while the whole control system is designed in labview. fea simulation and tests show that the exoskeleton is suitable for an average human weight of 62 kg plus excess force with different reactive spring forces. however, due to the mechanical properties of the exoskeleton actuator, it will require additional lift to provide the rapid reactive impulse force needed to increase biomechanical movement such as squatting up. finally, with the increasing availability of such assistive devices on the market, the important aspect of ethical, social and legal issues have also emerged and discussed in this paper. (author) keywords: leg-exoskeleton; electromyography based exoskeleton; labview myrio; ethical, societal, and legal concerns. tinton dwi atmaja a, dian andriani b, rudi darussalam a (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b research unit for clean technology, indonesian institute of science, indonesia) smart grid communication applications: measurement equipment and networks architecture for data and energy flow journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 2, p. 73-84, 10 ill, 5 tab, 63 ref. smart grid is an advanced two way data and energy flow capable of self-healing, adaptive, resilient, and sustainable journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv with prediction capability of possible fault. this article aimed to disclose smart grid communication in a logical way to facilitate the understanding of each component function. the study was focused on the improvement, advantages, common used design, and possible feature of smart grid communication components. the results of the study divide the smart grid communication application into two main category i.e. measurement equipment and network architecture. measurement equipment consists of advance metering infrastructure, phasor measurement unit, intelligent electronic devices, and wide area measurement system. the network architecture is divided based on three hierarchies; local area network for 1 to 100 m with 100 kbps data rate, neighbour area network for 100 m to 10 km with 100 mbps data rate, and wide area network for up to 100 km with 1 gbps data rate. more information is provided regarding the routing protocol for each network from various available protocols. the final section presents the energy and data flow architecture for smart grid implementation based on the measurement equipment and the network suitability. this article is expected to provide a comprehensive guide and comparison surrounding the technologies supporting smart grid implementation especially on communication applications. (author) keywords: smart grid application; phasor measurement unit; communication network; communication protocol; energy and data flow. mostafa nazih (building, infrastructure and advanced facilities, jacobs, australia) safety assessment of high voltage substation earthing systems with synthetic geotextile membrane journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 2, p. 85-91, 7 ill, 4 tab, 17 ref. high voltage substations built within areas prone to vegetation or with unfavourable subgrade conditions are paved with the addition of punched geotextiles and nonconductive synthetic fabrics underneath switchyard surfacing. the aim of this research is to identify the impact of synthetic textiles on earthing system performance through numerical analysis with the state-of-the-art software package. the new layer interferes with the earthing grids performance with a different behaviour depending on the installation above or underneath the layer with considerable impact taking place when the earthing grid is installed above the geotextile layer. rods penetrating the geotextile can alleviate the potential voltage distribution issues and improve the earthing system performance regardless of the native soil stratification. (author) keywords: substation earthing; synthetic geotextile; tolerable voltages; high voltage. dalmasius ganjar subagio, ridwan arief subekti, hendri maja saputra, ahmad rajani, kadek heri sanjaya (research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia) three axis deviation analysis of cnc milling machine journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 2, p. 93-101, 12 ill, 4 tab, 31 ref. the manufacturing technology has developed rapidly, especially those intended to improve the precision. consequently, increasing precision requires greater technical capabilities in the field of measurement. a prototype of a 3-axis cnc milling machine has been designed and developed in the research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi). the cnc milling machine is driven by a 0.4 kw servo motor with a spindle rotation of 12,000 rpm. this study aims to measure the precision of the cnc milling machine by carrying out the measurement process. it is expected that the cnc milling machine will be able toperform in an optimum precision during the manufacturing process. accuracy level testing is done by measuring the deviations on the three axes namely x-axis, y-axis, and z-axis, as well as the flatness using a dial indicator and parallel plates. the measurement results show the deviation on the x-axis by 0.033 mm, the y-axis by 0.102 mm, the z-axis by 0.063 mm, and the flatness of the table by 0.096 mm, respectively. it is confirmed that the deviation value is within the tolerance standard limits set by iso 2768 standard. however, the calibration is required for this cnc milling machine to achieve more accurate precision. furthermore, the design improvement of cnc milling machine and the application of information technology in accordance with industry 4.0 concept will enhance the precision and realibility. (author) keywords: precision measurement; orthogonal axes; manufacturing machine; automation industry. mev journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.85-91 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015 (sinta 2). safety assessment of high voltage substation earthing systems with synthetic geotextile membrane mostafa nazih * building, infrastructure and advanced facilities, jacobs 452 flinders st., melbourne, vic 3000, australia received 9 december 2019; accepted 21 december 2019 abstract high voltage substations built within areas prone to vegetation or with unfavourable subgrade conditions are paved with the addition of punched geotextiles and non-conductive synthetic fabrics underneath switchyard surfacing. the aim of this research is to identify the impact of synthetic textiles on earthing system performance through numerical analysis with the state-of-the-art software package. the new layer interferes with the earthing grid's performance with different behaviour depending on the installation above or underneath the layer with considerable impact taking place when the earthing grid is installed above the geotextile layer. rods penetrating the geotextile can alleviate the potential voltage distribution issues and improve the earthing system performance regardless of the native soil stratification. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: substation earthing; synthetic geotextile; tolerable voltages; high voltage. i. introduction personal safety is paramount for hv substation earthing systems in addition to system requirements for neutral voltage reference, earth fault detection and electrostatic control [1]. substation safety is assessed by comparing attained surface voltages, expressed as touch and step voltages as well as transferred voltages, to tolerable limits [2][3]. surface voltages depend on soil stratification where fault currents prefer to go through layers of lower resistivities with less voltage gradients while high resistivity layers contribute to greater gradients and thus, touch and step voltages [4]. polyester geotextiles with pores around 100 microns are laid underneath switchyard surface at an average depth of about 900 mm to control vegetation. different types of geotextiles may be used to improve subgrade soil conditions during construction. the insulating nature of the geotextile interferes with the native soil stratification by introducing a very thin layer with very high resistivity. example installation underneath a new switchyard is shown in figure 1. the recent research review on native soil modifications indicates that the relations with high voltage substation earthing and synthetic geotextiles have not been studied [5][6][7][8][9][10][11][12][13]. this paper sheds some light on the subject since the trend to involve geotextiles is on the rise for substations within australia and other parts of the world. the paper investigates the mechanism of action of the included layer as well as two case studies for green and brown field applications. ii. materials and methods a. fault current in soil the introduction of geotextile underneath switchyard surface can be modelled as a thin layer with very high electrical resistivity. the level of earthing grids above or under the geotextile controls the surface voltage distribution and overall resistance to remote earth. for earthing grids above the geotextiles, fault current normally prefers to flow through the surface layer creating gradients proportional to the layer resistivity which can negatively impact the safety assessment. for earthing grids installed under the geotextiles, no significant changes are envisaged to grid resistance. surface voltages will be very similar to the case with no geotextiles. * corresponding author. tel: +61-386683739 e-mail address: mostafa0020@yahoo.com https://dx.doi.org/10.14203/j.mev.2019.v10.85-91 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.85-91 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.201.v10.85-91&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 86 b. geotextile modelling geotextiles are made of polyester, which is a dielectric material with a typical bulk resistivity of about 1011 to 1015 ωm [14]. although the commercially available geotextiles to control vegetation are permeable to water flow with surface flow rates vary between 100 to 200 litre/m2/sec [14], it is considered to have a very high electrical resistivity since the pores are not sufficient to achieve reliable native soil contact through the geotextile in dry conditions. the geotextiles are not normally tested for the electrical resistivity and an estimated value of 10,000 ωm has been considered for the dry material based on corresponding values for a porous insulating material like wood [15]. higher values reaching 50,000 ωm are assumed for dry conditions. various manufacturers have been approached for electrical testing of their material with negative feedback since the electrical testing of geotextile is a non-standard test. due its thin construction and insulating properties, it is not possible to measure or even detect the presence of a geotextile once installed using site based soil resistivity measurements (e.g. schlumberger, wenner methods) [16]. the geotextiles are envisaged to interference with the soil resistivity measurements by blocking the deeper soil layers interaction and a quick results saturation will be reached versus spacing. the geotextiles are modelled in current distribution, electromagnetic interference, grounding and soil (cdegs) structure analysis software embedded soil volume option. since the soil model with geotextiles has a high degree of heterogeneity, memory allocation and processing time is considerably greater than cases with no geotextiles. c. safety criteria tolerable touch and step voltages are traditionally considered to compare versus attainable voltages within and around high voltage installations to assess the personal safety criteria parameters. with the use of high resistivity layer, the tolerable touch and step voltages, if the earthing grid is installed underneath the geotextile, will be impacted as the deeper native soil will be, theoretically, out of action and replaced by the high resistivity layer. equation (1) from ieee 80:2013 simplified formula for surface layer derating factor cs [3] 𝐶𝑠 = 1 − 0.09(1− 𝜌 𝜌𝑠 ) 2ℎ𝑠+0.09 (1) where ρ represents the geotextile resistivity, ρs surface soil resistivity and hs is the depth of the geotextile. with estimated values ranging from 5,000 ωm to 50,000 ωm for geotextile resistivity depending on soil dryness and seasonal variations, the tolerable touch and step voltages will be higher than that with no geotextile, assuming a uniform soil model. the increase in a tolerable touch voltage is inversely proportional to the surface soil resistivity with behaviour shown in figure 2 for 50 kg weight persons. the tolerable touch voltages (vtouch50kg) are calculated for fault duration t of 0.5 seconds based on ieee 80:2013 equation (2) [3] 𝑉𝑡𝑜𝑢𝑐ℎ 50𝑘𝑔 = (1000 + 1.5 × 𝐶𝑠 × 𝜌𝑠 ) 0.116 √𝑡 (2) where native/surface soil resistivity is relatively low (less than 50 ωm), an increase in the tolerable touch voltage of up to 350 % can be obtained in dry conditions where the geotextiles are assumed to have very high resistivity values in the range of 50,000 ωm. in the other hand, where the soil is wet, as the water figure 1. installation of geotextile underneath new switchyard during construction figure 2. touch voltage increase (%) versus surface soil resistivity (0.9 m deep geotextile) 0 50 100 150 200 250 300 350 400 1 0 7 0 1 3 0 1 9 0 2 5 0 3 1 0 3 7 0 4 3 0 4 9 0 5 5 0 6 1 0 6 7 0 7 3 0 7 9 0 8 5 0 9 1 0 9 7 0% i n cr e a se i n t o le ra b le t o u ch vo lt a g e surface resistivity (ω.m) 5k ω.m 10k ω.m 50k ω.m m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 87 flows through the membrane, resistivity is assumed to decline sharply and less effect on tolerable touch voltage is envisaged. the depth of the geotextile layer also affects the tolerable voltages as with shallow installations, the high resistivity layer will be near to the surface and hence, its effect will be greater. variation of touch voltage with geotextile depth is typically depicted in figure 3 with two different surfaces (native) soil resistivities 100 ωm and 1000 ωm. a sharp drop in the tolerable touch voltages is observed for geotextile installations deeper than 0.15 0.2 m from the finished surface. typical geotextile installation depth is about 0.5 1 m. iii. results and discussions a. case study i the first case under study is for a new open terminal substation 500/220 kv with overall dimensions of 144 x 70 m. the native soil measurements at site modelled with cdegs resap [17] with a 3-layer stratification as shown in figure 4. high resistivity layers on a low one are considered in this case where deeper layers permit most of the current to propagate through away from the surface. earth fault current of 10 ka is used to represent the available 500 kv single phase to earth fault with a duration of 100 ms. tolerable touch and step voltages figure 3. touch voltage increase (%) versus surface textile depth 0 500 1000 1500 2000 2500 3000 3500 0 ,0 5 0 ,1 5 0 ,2 5 0 ,3 5 0 ,4 5 0 ,5 5 0 ,6 5 0 ,7 5 0 ,8 5 0 ,9 5 1 ,0 5 1 ,1 5 1 ,2 5 1 ,3 5 1 ,4 5 1 ,5 5 % i n cr e a se i n t o le ra b le t o u ch vo lt a g e geotextile depth (m) 100/10k ω.m 100/50k ω.m 1000/10k ω.m 1000/50k ω.m figure 4. native soil model showing 3-layer soil with high on low resistivity stratification m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 88 have been calculated using ieee 80:2013 formulae [3]. switchyard surfacing with an average resistivity of 150 ωm is added as a top layer along with needle punched polyester geotextile with 100 micron pores to represent the final soil stratification as shown in table 1. tolerable touch and step voltages for the substation are tabulated in table 2. 1) initial grid design with no geotextile unsymmetrically spaced earthing grid with overall dimensions of 124 x 48 m and 10 x 1.5 m rods used for this substation initially without considering additional geotextile as shown in figure 5. substation fence has a separate earthing ring not connected to the main grid. the initial grid design is meeting the tolerable touch and step criteria. cdegs results for the initial grid design with no textiles shows an earthing resistance of 0.122 ω achieving the safety criteria within and around the site with tolerable touch voltages about 1100 v and 816 v, respectively (based on ieee 80:2013 criteria for a 70 kg (inside) and 50 kg (outside) person including a footwear resistance of 2000 ω per foot). 2) modified grid design although the addition of geotextile raises tolerable touch voltage by about 25 %, the overall earthing resistance increases by about 61 % with unsafe touch voltages within the substation. accordingly, the grid design is set for improvement by replacing 1.5 m rods with longer ones (3 m each) and an additional 13 x 3 m rods spread throughout the grid. the improvement is considered to utilize the deeper lower resistivity soil layers. it is evident that the addition of geotextile completely covering the earthing grid increases the overall earthing system impedance to remote earth, which in turn may require additional remedial solutions in case that the associated touch and step voltages exceed the tolerable limits. nevertheless, in this case, the increase in resistance and touch/step voltages with geotextiles is much more than the increase in tolerable voltages and hence, additional remedial solutions are required by installing additional rods. b. case study ii the second case under study is for an existing substation with overall dimensions of about 140 x 110 m and proposed extension of 90 x 70 m as shown in figure 6 where geotextile is used under the earthing grid extension due to soil stability conditions. the existing earthing grid is adequately designed with tolerable touch and step voltages. the native soil measurements at site modelled with cdegs resap [17] show a 2-layer stratification as shown in figure 7 indicating a lower layer with high resistivity. this is a case of interest as the addition of rods is not supposed to significantly affect the earthing grid impedance. the extension does not include additional sources for fault current contributions and hence, the epr is considered virtually constant (it will be practically lower than the existing situation since additional conductors within the extension area reduce the overall earthing system resistance and epr accordingly). table 1. modified soil model soil layer soil resistivity (ω m) layer thickness (m) ρ 1 150.00 0.9 ρ 2 10000.00 0.05 ρ 3 288.61 0.63 ρ 4 12.93 2.63 ρ 5 4.77 infinite figure 5. earthing grid model in cdegs with buried conductors and fenceline table 2. earthing grid performance parameters for case i parameter no fabric fabric % change modified design earthing system impedance (ω) 0.122 0.197 61.5 0.133 fault current (ka) 10 10 0.0 10 earth potential rise (epr) (v) 1225 1977 61.4 1335 max. attainable touch voltage within substation (v) 958 1576 64.5 984 tolerable touch voltage inside substation (v) – 70 kg 1105 1454 31.6 1454 max. attainable touch voltage outside substation (v) 46 59 28.3 51 tolerable touch voltage outside substation (v) – 50 kg 816 816 0.0 816 max. attainable step voltage inside substation (v) 551 718 30.3 452 tolerable step voltage inside substation (v) – 70 kg 2929 4326 47.7 4326 max. attainable step voltage outside substation (v) 7 20 185.7 17 tolerable step voltage outside substation (v) – 50 kg 2164 2164 0.0 2164 m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 89 in the case of faulty equipment within the extension area, earth return fault current will leak from earthing conductors at the existing earthing grid rather than the new extension area as the immediate vicinity of the extension has a high resistivity layer underneath it. nevertheless, a portion of the leakage current will flow upwards within the surface paving layer. the leakage current density confirms the hypothesis due to the higher resistivity layer underneath the grid extension. the lower leakage current density results at higher surface voltages, touch, and step voltages accordingly since the voltage drop over top soil from the grid to surface is smaller with less current leaking into deeper soil. the increase in surface voltage and touch voltage is figure 6. earthing grid cdegs model with existing and extension conductors figure 7. native soil model showing 2-layer soil with low on high resistivity stratification m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 90 accompanied by an increase in tolerable touch voltages as highlighted earlier. the increase in touch voltage is much less than the increase in tolerable limits. comparative results are tabulated in table 3. the fabric has about 0.3 % effect on the overall resistance and epr increase despite of the extension area representing about 29 % of total earthing system. notwithstanding that, the surface voltage distribution and leakage current density are altered with the presence of geotextiles. touch and step voltages appear to increase at both the geotextile covered and uncovered area. this behaviour is ascribed to higher surface voltages. 3 x 3 m rods are added to the corners of the extended grid to check the modified grid parameters. additions of rods +2.2 m in length, although the deeper layer has a higher resistivity, stabilises the voltage and current distribution where provided, alleviating the effect of geotextile on step voltages increase. if the soil model has a lower deeper resistivity layer, rods will be more effective in diverting fault current into deeper layers and hence, less surface voltage gradients. table 4 summarises the findings with additional rods. due to the higher resistivity deeper soil layers, the addition of rods has a negligible effect on resistance and epr. iv. conclusion the introduction of geotextiles changes the earthing system behaviour by interfering into leakage current distribution into the surface and deep soil layers. the location of the earthing grid affects the results with considerable impact taking place when the earthing grid is installed above the geotextile table 3. earthing grid performance parameters for case ii parameter extended grid without fabric extended grid with fabric total existing extension ratio (%) total existing extension ratio (%) earthing system impedance (ω) 2.76 2.77 fault current (ka) 1 1 earth potential rise (epr) (v) 2760 2760 2760 2769 2769 2769 max. attainable touch voltage within substation (v) 117 117 112 -4.27 124 124 119 -4.03 tolerable touch voltage inside substation (v) 675 675 0.00 675 897 32.89 max. attainable touch voltage outside substation (v) 234 234 225 -3.85 247 247 239 -3.24 tolerable touch voltage outside substation (v) barefoot 267 267 0.00 267 267 0.00 max. attainable step voltage inside substation (v) 66 52 66 26.92 77 51 77 50.98 tolerable step voltage inside substation (v) 1758 1758 0.00 1758 2647 50.57 max. attainable step voltage outside substation (v) 86 86 83 -3.49 96 85 96 12.94 tolerable step voltage outside substation (v) 371 371 0.00 371 371 0.00 table 4. earthing grid performance parameters for case ii – with additional 3 x 3 m rods parameter extended grid without fabric extended grid with fabric total existing extension ratio (%) total existing extension ratio (%) earthing system impedance (ω) 2.76 2.77 fault current (ka) 1 1 earth potential rise (epr) (v) 2760 2760 2760 2769 2769 2769 max. attainable touch voltage within substation (v) 117 117 112 -4.27 124 124 119 -4.03 tolerable touch voltage inside substation (v) 675 675 0.00 675 897 32.89 max. attainable touch voltage outside substation (v) 234 234 225 -3.85 247 247 239 -3.24 tolerable touch voltage outside substation (v) barefoot 267 267 0.00 267 267 0.00 max. attainable step voltage inside substation (v) 66 52 66 26.92 78 60 78 30.00 tolerable step voltage inside substation (v) 1758 1758 0.00 1758 2647 50.57 max. attainable step voltage outside substation (v) 86 86 83 -3.49 97 85 97 14.12 tolerable step voltage outside substation (v) 371 371 0.00 371 371 0.00 m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 91 layer. the tolerable touch and step voltages increase proportionally to the ratio between the surface soil and geotextile resistivity where the latter is considered to change with seasonal variations and soil water content. a typical tolerable touch voltage increase of about 60 % is envisaged for native surface soil of 100 ωm. the addition of geotextiles and associated increase in tolerable touch (and step) voltages may alleviate the need for additional high resistivity finish materials. earthing system behaviour in the presence of geotextiles depends on whether the textile covers the grid area completely or partially. the greatest impact on earthing system impedance and surface voltage distribution is expected for new substation installations where geotextile covers the grid completely. with partial coverage such as substation extensions, the impact is negligible on overall earthing system impedance. vertical rods penetrating the geotextile layers when the earthing grid is installed above it are effective to alleviate the increase in surface voltages due to geotextiles even with deeper soil layers having a high resistivity. rods should be spread through the earthing grid and corners to ensure proper current dispersion into deeper soil layers away from the surface as possible. acknowledgement the author would like to express grateful gratitude to jacobs australia pty. for providing engineering software used in this study. declarations author contribution m. nazih as the contributor of this paper. author read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the author declares no conflict of interest. additional information no additional information is available for this paper. references [1] j. he, r. zeng, b. zhang, methodology and technology for power system grounding, john wiley & sons, 2013. [2] iec 60479-1:2018: effects of current on human beings and livestock part 1: general aspects. [3] ieee guide for safety in ac substation grounding, in ieee std 80-2013 (revision of ieee std 80-2000/ incorporates ieee std 80-2013/cor 1-2015), pp. 1-226, 15 may 2015. [4] j. liu, f. p. dawalibi, s. tee, “analysis of current density in soil for resistivity measurements and electrical grounding designs,” journal of electrical and electronic engineering, vol. 5, no. 5, pp. 198-208, 2017. [5] b. alsharari, a. olenko, h. abuel-naga, modeling of electrical resistivity of soil based on geotechnical properties, expert systems with applications, 141, 112966, available online 19 september 2019. [6] r. a. fayed and a. s. ezeldin, simulation and optimization model for electrical substation construction. phd diss., american univeristy in cairo, 2016. [7] a. ackerman, p. k. sen, and c. oertli, designing safe and reliable grounding in ac substations with poor soil resistivity: an interpretation of ieee std. 80, record of conference papers annual petroleum and chemical industry conference, 49 (4), 1883-1889, 2012. [8] r. d. southey, m. siahrang, s. fortin, and f. p. dawalibi, “using fall-of-potential measurements to improve deep soil resistivity estimates,” ieee transactions on industry applications, 51(6), 5023-5029, 2015. [9] s. c. lim, c. gomes, and m. z. a. ab kadir, “electrical earthing in troubled environment,” international journal of electrical power and energy systems, 47(1), 117-128, 2013. [10] j. e. edlebeck and b. beske, “identifying and quantifying material properties that impact aggregate resistivity of electrical substation surface material,” ieee transactions on power delivery, 29(5), 2248-2253, 2014. [11] c. j. f. p. jones, j. lamont-black, and s. glendinning, “electrokinetic geosynthetics in hydraulic applications,” geotextiles and geomembranes, 29(4), 381-390, 2011. [12] a. n. ramani, a. r. ahmad, m. f. sulaima, m. n. m. nasir, and a. ahmad, “analysis the configuration of earthing system based on high-low and low-high soil structure,” aip conference proceedings, 1660, 2015. [13] w. l. lai, w. f. h. wan ahmad, j. jasni, and m. z. a. ab kadir, “a review on the usage of zeolite, perlite and vermiculite as natural enhancement materials for grounding system installations,” ieee student conference on research and development: inspiring technology for humanity, scored 2017 proceedings, 2018-january, 338-343, 2018. [14] global synthetics, geofirma technical datasheet. [15] c. skaar, electrical properties of wood, in: wood-water relations, springer series in wood science, springer, berlin, heidelberg, 1988. [16] “ieee guide for measuring earth resistivity, ground impedance, and earth surface potentials of a grounding system," in ieee std 81-2012 (revision of ieee std 81-1983), pp. 1-86, 28 dec. 2012. [17] cdegs resap soil resistivity analysis module – safe engineering services & technologies ltd., canada. https://doi.org/10.1002/9781118255001.ch6 https://doi.org/10.1002/9781118255001.ch6 https://doi.org/10.3403/30376583 https://doi.org/10.3403/30376583 https://doi.org/10.1109/ieeestd.2015.7109078 https://doi.org/10.1109/ieeestd.2015.7109078 https://doi.org/10.1109/ieeestd.2015.7109078 https://doi.org/10.11648/j.jeee.20170505.17 https://doi.org/10.11648/j.jeee.20170505.17 https://doi.org/10.11648/j.jeee.20170505.17 https://doi.org/10.11648/j.jeee.20170505.17 https://doi.org/10.1016/j.eswa.2019.112966 https://doi.org/10.1016/j.eswa.2019.112966 https://doi.org/10.1016/j.eswa.2019.112966 https://doi.org/10.1016/j.eswa.2019.112966 https://www.itcon.org/paper/2018/11 https://www.itcon.org/paper/2018/11 https://www.itcon.org/paper/2018/11 https://doi.org/10.1109/pcicon.2012.6549644 https://doi.org/10.1109/pcicon.2012.6549644 https://doi.org/10.1109/pcicon.2012.6549644 https://doi.org/10.1109/pcicon.2012.6549644 https://doi.org/10.1109/pcicon.2012.6549644 https://doi.org/10.1109/tia.2015.2428679 https://doi.org/10.1109/tia.2015.2428679 https://doi.org/10.1109/tia.2015.2428679 https://doi.org/10.1109/tia.2015.2428679 https://doi.org/10.1016/j.ijepes.2012.10.058 https://doi.org/10.1016/j.ijepes.2012.10.058 https://doi.org/10.1016/j.ijepes.2012.10.058 https://doi.org/10.1109/tpwrd.2013.2284819 https://doi.org/10.1109/tpwrd.2013.2284819 https://doi.org/10.1109/tpwrd.2013.2284819 https://doi.org/10.1109/tpwrd.2013.2284819 https://doi.org/10.1016/j.geotexmem.2010.11.011 https://doi.org/10.1016/j.geotexmem.2010.11.011 https://doi.org/10.1016/j.geotexmem.2010.11.011 https://doi.org/10.1063/1.4915857 https://doi.org/10.1063/1.4915857 https://doi.org/10.1063/1.4915857 https://doi.org/10.1063/1.4915857 https://doi.org/10.1109/scored.2017.8305368 https://doi.org/10.1109/scored.2017.8305368 https://doi.org/10.1109/scored.2017.8305368 https://doi.org/10.1109/scored.2017.8305368 https://doi.org/10.1109/scored.2017.8305368 https://doi.org/10.1109/scored.2017.8305368 https://globalsynthetics.com.au/wp-content/uploads/2015/12/global-synthetics-geofirma-datasheet.pdf https://doi.org/10.1007/978-3-642-73683-4 https://doi.org/10.1007/978-3-642-73683-4 https://doi.org/10.1007/978-3-642-73683-4 https://doi.org/10.1109/ieeestd.2012.6392181 https://doi.org/10.1109/ieeestd.2012.6392181 https://doi.org/10.1109/ieeestd.2012.6392181 https://doi.org/10.1109/ieeestd.2012.6392181 https://www.sestech.com/en/product/module/resap https://www.sestech.com/en/product/module/resap m. nazih / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 85-91 92 this page intentionally left blank mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.30-37 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance ghalya pikra a,*, nur rohmah b, rakhmad indra pramana a, andri joko purwanto a a research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi bandung, gd 20, lt 2, bandung, west java, 40135 indonesia b research unit for clean technology, indonesian institute of sciences komplek lipi bandung, gedung 50, bandung, west java, 40135, indonesia received 15 may 2020; accepted 10 june 2020; published online 30 july 2020 abstract single-stage regenerative organic rankine cycle (ssrorc) is a system that is used for increasing the simple organic rankine cycle (orc) performance. open feed organic heater (ofoh) addition in the orc system increase power and efficiency of the system. this paper analyzes the ssrorc performance with a variation of p6/p1 ranges from 1.25 to 3.75 with an increment of 0.25, where p6 is the ofoh pressure at the inlet side and p1 is the pressure at the inlet pump 1, respectively. hot water was used as the heat source with 100 °c and 100 l/min of temperature and volume flow rate as the initial data. r227ea, r245fa, and r141b were chosen as working fluids for performance analysis. the analysis was performed by calculating the heat input, heat loss, pump and turbine power, net power, and thermal efficiency through energy balance. exergy input, exergy output, and exergy efficiency were analyzed through exergy balance. the results show that p6/p1 = 2 obtains the highest performance than the other pressure ratios for r227ea, while r245fa and r141b obtain the highest performance at p6/p1 = 2.25. r141b has better performance than the other two fluids with 10.97 % and 11.96 % for thermal and exergy efficiency. the results show that the ratio of ofoh pressure at the inlet side to the pressure at inlet pump 1 (p6/p1) in the middle value obtains the best performance. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: single-stage regenerative organic rankine cycle; open feed organic heater; r227ea; r245fa; r141b. i. introduction electricity needs are increasing in this globalization era. on the other hand, the availability of fossil fuels is running low, so it is necessary to find other alternative sources before fossil fuels could no longer meet the world's electricity demands. renewable energy has begun to be developed in various parts of the world. during this time, the rankine cycle has been known as one of the many power generation systems developed and used to generate electricity. water is commonly used as a working fluid that can only generate electricity at high operating temperatures, whereas existing renewable energy such as geothermal, solar, and waste heat allows it to be used as a heat source to generate electricity at low and medium operating temperatures so that the use of water must be replaced for the renewable energy utilization. therefore, organic fluids which have lower boiling temperatures than water can be used in the system to produce electricity at low and medium operating temperatures. this system is known as the organic rankine cycle (orc) which has the same components as the rankine cycle but can produce electricity at low and moderate operating temperatures by using organic fluid as a working fluid. organic rankine cycle (orc) has been utilized in many heat sources, such as biomass [1], geothermal [2][3][4], solar [5], ocean thermal [6], and waste heat [7][8][9]. this system can also be combined with other cycles so that the use of heat sources can be maximized and the heat loss in the system can be reduced. however, because of the low operating temperature, the orc system has a low performance. modification of the orc configuration is one of many ways that can be used to increase the orc * corresponding author. phone: +6222-2503055 e-mail address: ghalya30@gmail.com; ghal001@lipi.go.id https://dx.doi.org/10.14203/j.mev.2020.v11.30-37 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.30-37 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.30-37&domain=pdf https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.30-37&domain=pdf https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.30-37&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.30-37&domain=pdf mailto:ghalya30@gmail.com https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.30-37&domain=pdf g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 31 system performance. many orc configurations have been studied and experimented by many researchers in order to enhance the system performance. li et al. compared parallel and series of two-stage organic rankine cycle and as a result, the series configuration has a better performance than the parallel [10]. k. braimakis and s. karellas investigated an open and closed preheater that resulting in better performance by using a closed preheater [11]. li et al. optimized the orc using dual-pressure evaporation and analyze nine different working fluids with 100-200 °c of heat source temperature. the optimization showed an increase in net power output between 21.4 – 26.7 % [12]. sciubba et al. compared double stage orcs and a recuperator addition that resulting in an electricity generation increment up to 8.11 % and 2.67 %, respectively [8]. mosaffa et al. studied regenerative and recuperative orcs for geothermal energy that obtain high efficiency [4]. xi et al. optimized the orc using single and double stage regenerative orcs and shows that the double stage has the highest energy and exergy efficiency [13]. zare compared three configurations such as a simple orc, a recuperative orc, and an open-type regenerative preheater orc for binary geothermal power plants. the result shows that simple orc obtains the highest power output and the lowest economic cost, and recuperative orc observed the best energy and exergy efficiency [14]. safarian and aramoun evaluated a simple and regenerative-recuperative orc and examined that the regenerativerecuperative orc has the best thermal efficiency [15]. single-stage regenerative organic rankine cycle (ssrorc) is one of many configurations that can increase the orc system performance. inspired from our previous research [16] about the performance comparison of single ssrorc and double stage of regenerative organic rankine cycle (dsrorc), this paper discusses the pressure analysis of an open feed organic heater (ofoh) in a single-stage regenerative organic rankine cycle (ssrorc), since our previous research assumes that the pressure entering the ofoh is constant. eleven different pressure values are investigated to determine the best performance. those pressures were based on the ratio of pressure at inlet pump 1 and the pressure at inlet ofoh, that is, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75. temperature and volume flow rate of 100 °c and 100 l/min are used as the initial data using water as the heat source. three working fluids such as r227ea, r245fa, and r141b are compared and analyzed to determine the best performance. because the pressure at inlet ofoh must be lower than the inlet turbine pressure, then r227ea can only be used until the maximum pressure ratio of 3.25. ii. materials and methods a simple organic rankine cycle consists of four main components, such as evaporator, turbine, condenser, and pump. a modification of the orc system configuration is necessary to increase its performance. open feed organic heater (ofoh) addition in the orc system is one of many modifications that can enhance the system performance. the addition of ofoh in the system is commonly called as a single-stage regenerative organic rankine cycle (ssrorc). figure 1 shows the scheme of ssrorc. the working principle of ssrorc that is shown in figure 1 is almost the same with the simple orc. the simple orc only uses one pump and do not use an open feed organic heater (ofoh). in the simple orc, the fluid from the condenser (1) is directly pumped to the evaporator (4) to be vaporized and expanded in the turbine (5). all of the expanded fluids are condensed in the condenser (7) to be pumped back to the evaporator (4). the ssrorc has an ofoh (6) and one additional pump (3) so that some of the expanded fluids from the turbine flow directly to the ofoh (6) while some other fluids are condensed in the condenser (7) prior to being pumped back to ofoh and finally be pumped to the evaporator. this configuration has a possibility to decrease the heat loss in the condenser and subsequently increase the system performance. this paper analyzes the ofoh pressure influence on the performance of the ssrorc system. it analyzes eleven states of ofoh pressure from the ratio of pressure at inlet pump 1 (p1) and the ofoh inlet (p6). the p6/p1 values used in this study are 1.25, figure 1. configuration of single-stage regenerative organic rankine cycle (ssrorc) g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 32 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, and 3.75. the t-s diagram from figure 2 shows all states at each component of ssrorc. figure 2 shows that the pressure at the state 1 (p1) is the same as the pressure at 7 (p7), the pressure at 2 (p2) is the same as the pressure at 3 and 6 (p3 and p6), and the pressure at 4 (p4) is the same as the pressure at 5 (p5). the pressure at 6 as shown in figure 2 is made varied for the analysis requirement. the performance analysis was carried out using the first and second laws of thermodynamics through energy and exergy balance from moran et al. [17]. figure 3 shows the flowchart of the analysis. figure 3 shows that the initial temperature and volume flow rate of the heat source (water) for all fluids and all states are assumed to be constant at 100 °c and 100 l/min. the inlet temperature of the turbine (t5) is 90 °c which is at saturated vapor state, and the inlet temperature of the pump 1 (t1) is 40 °c which is at saturated liquid state. both states are assumed constant for various p6. isentropic efficiency of the pump and the turbine are assumed 0.75 and 0.85, while the potential and kinetic energy are negligible. the analysis started with heat input (𝑄𝑖𝑖) and heat loss (𝑄𝑙𝑙𝑙𝑙) calculation from energy balance at the evaporator and condenser. the calculation was continued with pump power (𝑊𝑝) and turbine power (𝑊𝑡) calculation from energy balance at the pump and the turbine to determine the net power output. the thermal efficiency (𝜂𝑡ℎ) obtained from the ratio of net power output and the heat input. the calculation of 𝑄𝑖𝑖, 𝑄𝑙𝑙𝑙𝑙, 𝑊𝑝, 𝑊𝑡, and 𝜂𝑡ℎ is shown in equations (1) to (5) 𝑄𝑖𝑖 = �̇�𝑙𝑓(ℎ5 − ℎ4) = �̇�ℎ𝑤𝐶𝑝ℎ𝑤(𝑇9 − 𝑇8) (1) 𝑄𝑙𝑙𝑙𝑙 = �̇�𝑙𝑓(1 − 𝑦)(ℎ7 − ℎ1) (2) 𝑊𝑝 = �̇�𝑙𝑓[(ℎ4 − ℎ3) + (1 − 𝑦)(ℎ2 − ℎ1)] = �̇�𝑙𝑓 𝜂𝑝⁄ [(ℎ4𝑙 − ℎ3) + (1 − 𝑦)(ℎ2𝑙 − ℎ1)] (3) wt = ṁof[(h5 − h6) + (1 − y)(h6 − h7)] = figure 2. t-s diagram of ssrorc figure 3. flowchart of ssrorc performance analysis g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 33 ṁofηt[(h5 − h6s) + (1 − y)(h6 − h7s)] (4) ηth = wt−wp qin = wnet qin (5) where 𝑄𝑖𝑖 is heat input (kw); �̇�𝑙𝑓 is the organic fluid mass flow rate (kg/s); �̇�ℎ𝑤 is heat source mass flow rate (kg/s); 𝐶𝑝ℎ𝑤 is heat source heat capacity (kj/kg k); 𝑇8 is heat source temperature at inlet evaporator (°c); 𝑇9 is heat source temperature at outlet evaporator (°c); 𝑊𝑖𝑛𝑡 is net output (kw); 𝑄𝑙𝑙𝑙𝑙 is heat loss (kw); 𝑊𝑝 is pump power (kw); 𝑊𝑡 is turbine power (kw); ℎ1 is organic fluid enthalpy at inlet pump 1/outlet condenser (kj/kg); ℎ2 is organic fluid enthalpy at inlet ofoh/outlet pump 1 (kj/kg); ℎ2𝑙 is isentropic organic fluid enthalpy at inlet ofoh/outlet pump 1 (kj/kg); ℎ3 is organic fluid enthalpy at outlet ofoh/inlet pump 2 (kj/kg); ℎ4 is organic fluid enthalpy at outlet pump 2/inlet evaporator (kj/kg); ℎ4𝑙 is isentropic organic fluid enthalpy at outlet pump 2/inlet evaporator (kj/kg); ℎ5 is organic fluid enthalpy at outlet evaporator/inlet turbine (kj/kg); ℎ6 is organic fluid enthalpy at outlet turbine/inlet ofoh (kj/kg); ℎ6𝑙 is isentropic organic fluid enthalpy at outlet turbine/inlet ofoh (kj/kg); ℎ7 is organic fluid enthalpy at outlet turbine/inlet condenser (kj/kg); ℎ7𝑙 is isentropic organic fluid enthalpy at outlet turbine/inlet condenser (kj/kg); 𝜂𝑝 is isentropic efficiency of the pump; 𝜂𝑡 is isentropic efficiency of the turbine; 𝜂𝑡ℎ is thermal efficiency (%); and 𝑦 is the fraction of steam extracted. exergy input (𝐸𝐸𝑖𝑖 ), exergy loss (𝐸𝐸𝑙𝑙𝑙𝑙 ), and exergy efficiency (𝜂𝑛𝑒) are the parameter that would be calculated from the exergy side. the calculation of 𝐸𝐸𝑖𝑖, 𝐸𝐸𝑙𝑙𝑙𝑙, and 𝜂𝑛𝑒 are shown in equations (6) to (8) 𝐸𝐸𝑖𝑖 = �̇�𝑙𝑓[ℎ5 − ℎ4 − 𝑇𝑎𝑚𝑏(𝑠5 − 𝑠4)] (6) 𝐸𝐸𝑙𝑙𝑙𝑙 = �̇�𝑙𝑓(1 − 𝑦)[ℎ7 − ℎ1 − 𝑇𝑎𝑚𝑏(𝑠7 − 𝑠1)] (7) 𝜂𝑛𝑒 = 𝑊𝑡−𝑊𝑝 𝐸𝑒𝑖𝑛 = 𝑊𝑛𝑒𝑡 𝐸𝑒𝑖𝑛 (8) where 𝐸𝐸𝑖𝑖 is exergy input (kw); 𝐸𝐸𝑙𝑙𝑙𝑙 is exergy loss (kw); 𝜂𝑛𝑒 is exergy efficiency (%); 𝑇𝑎𝑚𝑏 is ambient temperature (°c); 𝑠1 is organic fluid entropy at inlet pump 1/outlet condenser (kj/kg k); 𝑠4 is organic fluid entropy at outlet pump 2/inlet evaporator (kj/kg k); 𝑠5 is organic fluid entropy at outlet evaporator/inlet turbine (kj/kgk); and 𝑠7 is organic fluid entropy at outlet turbine/inlet condenser (kj/kg k). r227ea, r245fa, and r141b are chosen as the working fluid for the analysis. they are chosen because they are suitable to be used at a low to medium heat source temperature [18][19]. the properties of the three fluids are shown in table 1 [20][21]. wet fluid type is not used in the analysis because it is more appropriate to be used for high temperature and the superheated condition [22][23]. a dry and isentropic fluid is a fluid type that is suitable to be used for a low and medium grade heat source [21]. iii. results and discussions the performance analysis is divided into 5 sections, that is heat input and heat loss analysis, pump and turbine power analysis, net power output and thermal efficiency analysis, exergy input and exergy output analysis, and lastly, the exergy efficiency analysis. the five sections are depicted as the step of the energy and exergy analysis to obtain the system performance of ssrorc with various ofoh pressure. a. heat input and heat loss analysis the results of heat input (𝑄𝑖𝑖 ) and heat loss (𝑄𝑙𝑙𝑙𝑙 ) calculations for three fluids in all eleven pressure values at the ofoh inlet the ofoh are shown in figure 4. figure 4 shows the same heat input values for all fluids at different p6/p1 because of the constant initial data for all states and all fluids. equation (1) shows that 𝑄𝑖𝑖 is influenced by the mass flow rate (�̇�ℎ𝑤 ), heat capacity (𝐶𝑝ℎ𝑤 ), and temperature differences (𝑇9 − 𝑇8) of the heat source. those three parameters are constant for all fluids and all p6/p1, hence the 𝑄𝑖𝑖becomes constant. figure 4 shows the heat loss (𝑄𝑙𝑙𝑙𝑙) for r227ea obtains the highest value and r141b obtains the lowest 𝑄𝑙𝑙𝑙𝑙 among the three different fluids. this condition is connected to the properties of each fluid that is shown in table 1, where r227ea has the lowest critical pressure and r141b has the highest critical pressure. the result determines that r227ea with the lowest critical pressure obtain a lower pressure at the same p6/p1 than the other fluids, thus made r227ea obtains the highest 𝑄𝑙𝑙𝑙𝑙 than others. r227ea obtains the lowest 𝑄𝑙𝑙𝑙𝑙 at p6/p1= 2, and the highest result is obtained from p6/p1 = 3.25. r245fa and r141b obtain their lowest 𝑄𝑙𝑙𝑙𝑙 at p6/p1 = 2.25, and their highest result is obtained from p6/p1= 3.75. figure 3 shows that the middle value between the ratio of ofoh pressure at the inlet side (p6) and pump 1 (p1) pressure at the inlet side shows the lowest heat loss for all fluids. b. pump power and turbine power analysis figure 5 shows the result of pump power and turbine power calculations for three fluids in eleven states of pressure at inlet the ofoh. figure 5 shows the highest 𝑊𝑝 obtained by r227ea, and the lowest table 1. properties of r227ea, r245fa, and r141b [20][21] properties r227ea r245fa r141b molecular weight (g/mol) 170.03 134.05 116.95 boiling temperature (°c) -16.19 15.29 32.2 critical temperature (°c) 101.9 154.16 204.5 critical pressure (bar) 28.7 36.1 42.1 type dry dry/isentropic isentropic g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 34 figure 4. 𝑄𝑖𝑖 and 𝑄𝑙𝑙𝑙𝑙 for each fluid atdifferent ofoh pressure 𝑊𝑝 obtained by r141b. moreover, r141b obtains the highest wt and r227ea obtains the lowest 𝑊𝑡.𝑊𝑝 for r227ea obtains the lowest and the highest result at p6/p1 = 3.25 and p6/p1 = 2.25, while 𝑊𝑡 obtains its lowest and highest result at p6/p1 = 3.25 and p6/p1 = 2. r245fa and r141b obtain the highest and the lowest 𝑊𝑝 at p6/p1 = 2.5 and p6/p1 = 3.75. furthermore, the 𝑊𝑡value for r245fa and r141b obtain at p6/p1 = 2.25 and p6/p1 = 3.75 for the highest and the lowest 𝑊𝑡.𝑊𝑝 value for each state and each fluid are not significantly different, while for 𝑊𝑡, the middle ratio of p6 and p1 obtain the highest value, and the lowest value obtains from the highest p6/p1, which is close to inlet turbine pressure, thus made it gain the lowest 𝑊𝑡 and 𝑊𝑝. the result of 𝑊𝑝 and 𝑊𝑡 are then used to determine the net power output (𝑊𝑖𝑛𝑡) of the system, thus will obtain the energy performance of the system. c. net power output and thermal efficiency analysis net power output and thermal efficiency calculation are the final energy analysis. the result is shown in figure 6. figure 6 shows that 𝑊𝑖𝑛𝑡 for r227ea obtains the highest result at p6/p1 = 2, r245fa and r141b at p6/p1 = 2.25. on the contrary, r227ea obtains the lowest 𝑊𝑖𝑛𝑡 at p6/p1 = 3.25, and r245fa and r141b at p6/p1 = 3.75 obtain the lowest 𝑊𝑖𝑛𝑡 . 𝑊𝑖𝑛𝑡 value is influenced by the difference between 𝑊𝑝 and 𝑊𝑡, which means that the higher 𝑊𝑡 and the lower 𝑊𝑝 obtain a high 𝑊𝑖𝑛𝑡. figure 5 shows that 𝑊𝑝 for r227ea obtains the lowest result at p6/p1 = 3.25, while 𝑊𝑡 obtains its highest result at p6/p1 = 2. the result shows that 𝑊𝑖𝑛𝑡 value is more influenced by 𝑊𝑡 than 𝑊𝑝 because 𝑊𝑖𝑛𝑡 value results in the highest value at p6/p1= 2, which is the same as 𝑊𝑡. figure 5. 𝑊𝑝and 𝑊𝑡 for each fluid at different ofoh pressure g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 35 furthermore, 𝑊𝑝 value obtains a very low value compared to 𝑊𝑡 , thus made 𝑊𝑖𝑛𝑡 value more influenced by 𝑊𝑡 than 𝑊𝑝 . r245fa and r141b also obtain the highest 𝑊𝑖𝑛𝑡 at p6/p1 = 2.25 because they obtain the highest 𝑊𝑡 at the same p6/p1. however, r141b obtains the highest 𝑊𝑖𝑛𝑡 value than r227ea and r245fa. the lowest 𝑊𝑝 value obtained by r141b than r227ea and r245fa made r141b obtain the highest 𝑊𝑖𝑛𝑡 since 𝑊𝑡 value for each fluid almost obtain the same result in the same condition. thermal efficiency (𝜂𝑡ℎ) value depends on heat input (𝑄𝑖𝑖) and 𝑊𝑖𝑛𝑡 value. since 𝑄𝑖𝑖 is the same for all fluids and all states, then 𝜂𝑡ℎ value depends on 𝑊𝑖𝑛𝑡. equation (5) shows that the higher the 𝑊𝑖𝑛𝑡 obtain a higher 𝜂𝑡ℎ. it is clear that figure 6 shows the highest 𝜂𝑡ℎ value for r227ea obtained from p6/p1 = 2, the lowest 𝜂𝑡ℎ obtained from p6/p1 = 3.25, which is the same states with 𝑊𝑖𝑛𝑡. the result also the same with r245fa and r141b, where 𝜂𝑡ℎ value obtains its highest value at p6/p1= 2.25, and they obtain the lowest 𝜂𝑡ℎ at p6/p1 = 3.75, the same with 𝑊𝑖𝑛𝑡 value. furthermore, r141b obtain the highest 𝜂𝑡ℎ than r245fa and r227ea because r141b gain the highest 𝑊𝑖𝑛𝑡 than other fluids. this result shows that r141b obtains the best energy performance than r227ea and r245fa. d. exergy input and exergy loss analysis exergy input and exergy loss are two main parameters for exergy analysis. the result of both parameters for three fluids in eleven states is shown in figure 7. figure 7 shows that all fluids obtain the highest 𝐸𝐸𝑖𝑖 at the highest p6/p1, which is 3.25 for r227ea, and 3.75 for r245fa and r141b. in addition, the lowest 𝐸𝐸𝑖𝑖 obtained from the lowest p6/p1, figure 6. 𝑊𝑖𝑛𝑡 and 𝜂𝑡ℎ for each fluid at different ofoh pressure figure 7. 𝐸𝐸𝑖𝑖 and 𝐸𝐸𝑙𝑙𝑙𝑙 for each fluid at different ofoh pressure g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 36 which is 1.25. it can be analyzed that the highest pressure difference from p1 and p6 obtain the highest 𝐸𝐸𝑖𝑖. however, 𝐸𝐸𝑖𝑖 value for all fluids at the same states obtain almost the same because of the same 𝑄𝑖𝑖 value for all fluids for all states. figure 7 shows that r227ea obtains its highest and its lowest 𝐸𝐸𝑙𝑙𝑙𝑙 at p6/p1 = 3.25 and at p6/p1= 1.75. similarly, r245fa and r141b obtain their highest and lowest 𝐸𝐸𝑙𝑙𝑙𝑙 at p6/p1 = 3.75 and at p6/p1 = 2.25. 𝐸𝐸𝑙𝑙𝑙𝑙 has a similar curve with the 𝑄𝑙𝑙𝑙𝑙, where it reaches the lowest p6/p1 in the middle and the highest p6/p1 at the highest value. the exergy input is then used to determine the exergy efficiency of the system. e. exergy efficiency analysis exergy efficiency is determined to perform the exergy performance of the system. figure 8 shows the results for the three fluids in eleven states of ofoh in the ssrorc system. figure 8 shows that 𝜂𝑛𝑒 obtains the highest value at p6/p1 = 1.75 for r227ea, nearly the same as at p6/p1 = 2, and at p6/p1 = 2.25 for r245fa and r141b. on the contrary, 𝜂𝑛𝑒 has the lowest value for r227ea at p6/p1 = 3.25, and for r245fa and r141b at p6/p1 = 3.75. the result is the same as 𝜂𝑡ℎ, where they obtain the highest value at the middle p6/p1 and the lowest value at the highest p6/p1. although 𝜂𝑛𝑒 depends on 𝑊𝑖𝑛𝑡 and 𝐸𝐸𝑖𝑖 value, in this analysis the 𝑊𝑖𝑛𝑡 result is more dominant than 𝐸𝐸𝑖𝑖 for 𝜂𝑛𝑒. since 𝐸𝐸𝑖𝑖 value is almost the same for all fluids and all states, the 𝜂𝑛𝑒 value has the same maximum and minimum value as 𝑊𝑖𝑛𝑡 and 𝜂𝑛𝑒. iv. conclusion open feed organic heater (ofoh) pressure analysis using eleven states obtain the best performance for r227ea at p6/p1 = 2 for energy analysis and at p6/p1 = 1.75 for exergy analysis, and at p6/p1 = 2.25 for r245fa and r141b. the lowest performance for r227ea was at p6/p1= 3.25, and at p6/p1 = 3.75 for r245fa and r141b. the analysis concluded that the p6/p1 in the middle value obtain the best performance, and the highest pressure difference from state 1 and state 6 obtain the lowest performance. r141b with the highest critical pressure than r227ea and r141b obtain the highest performance with thermal and exergy efficiency of 10.97 % and 11.96 %, thus made r141b is the most recommended fluid to be used for 100 °c of heat source temperature rather than r227ea and r245fa. since in this paper it is assumed that a constant heat source temperature is used in analyzing the ofoh pressure influence to the ssrorc performance, the variation of the heat source temperature will be done in the future to complete the analysis of ofoh pressure to the performance of ssrorc. acknowledgement the authors would like to thank the research centre for electrical power and mechatronics for supporting the organic rankine cycle research. we also would like to thank our research team in the conversion and conservation energy for helping the research. we also express our high gratitude to the reviewers who have provided input and suggestions so that this paper is qualified for publication. declarations author contribution g. pikra is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or non-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] d. roy, s. samanta, and s. ghosh, “techno-economic and environmental analyses of a biomass based system employing solid oxide fuel cell, externally fired gas turbine and organic rankine cycle,” j. clean. prod., vol. 225, pp. 36–57, 2019. [2] g. manente, a. lazzaretto, and e. bonamico, “design guidelines for the choice between single and dual pressure figure 8. 𝜂𝑛𝑒 for each fluid at different ofoh pressure https://doi.org/10.1016/j.jclepro.2019.03.261 https://doi.org/10.1016/j.jclepro.2019.03.261 https://doi.org/10.1016/j.jclepro.2019.03.261 https://doi.org/10.1016/j.jclepro.2019.03.261 http://dx.doi.org/10.1016/j.energy.2017.01.151 http://dx.doi.org/10.1016/j.energy.2017.01.151 g. pikra et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 30-37 37 layouts in organic rankine cycle (orc) systems,” energy, vol. 123, pp. 413–431, 2017. [3] n. chagnon-lessard and l. gosselin, “geothermal power plants with maximized specific power output : optimal working fluid and operating conditions of subcritical and transcritical organic rankine cycles,” geothermics, vol. 64, pp. 111–124, 2016. [4] a.h. mosaffa, n.h. mokarram, and l.g. farshi, “thermoeconomic analysis of combined different orcs geothermal power plants and lng cold energy,” geothermics, vol. 65, pp. 113–125, 2017. [5] s. quoilin, m. orosz, h. hemond, and v. lemort, “performance and design optimization of a low-cost solar organic rankine cycle for remote power generation,” sol. energy, vol. 85, no. 5, pp. 955–966, 2011. [6] f. sun, y. ikegami, b. jia, and h. arima, “optimization design and exergy analysis of organic rankine cycle in ocean thermal energy conversion,” appl. ocean res., vol. 35, pp. 38–46, 2012. [7] t. chen, w. zhuge, y. zhang, and l. zhang, “a novel cascade organic rankine cycle ( orc ) system for waste heat recovery of truck diesel engines,” energy convers. manag., vol. 138, pp. 210–223, 2017. [8] e. sciubba, l. tocci, and c. toro, “thermodynamic analysis of a rankine dual loop waste thermal energy recovery system,” energy convers. manag., vol. 122, pp. 109–118, 2016. [9] t. eller, f. heberle, and d. brüggemann, “second law analysis of novel working fl uid pairs for waste heat recovery by the kalina cycle,” energy, vol. 119, pp. 188–198, 2017. [10] t. li, z. zhang, j. lu, j. yang, and y. hu, “two-stage evaporation strategy to improve system performance for organic rankine cycle,” appl. energy, vol. 150, pp. 323–334, 2015. [11] k. braimakis and s. karellas, “energetic optimization of regenerative organic rankine cycle (orc) configurations,” energy convers. manag., vol. 159, no. january, pp. 353–370, 2018. [12] j. li, z. ge, y. duan, z. yang, and q. liu, “parametric optimization and thermodynamic performance comparison of single-pressure and dual-pressure evaporation organic rankine cycles,” appl. energy, vol. 217, no. february, pp. 409– 421, 2018. [13] h. xi, m.j. li, c. xu, and y.l. he, “parametric optimization of regenerative organic rankine cycle (orc) for low grade waste heat recovery using genetic algorithm,” energy, vol. 58, pp. 473–482, 2013. [14] v. zare, “a comparative exergoeconomic analysis of different orc configurations for binary geothermal power plants,” energy convers. manag., vol. 105, pp. 127–138, 2015. [15] s. safarian and f. aramoun, “energy and exergy assessments of modified organic rankine cycles (orcs),” energy reports, vol. 1, pp. 1–7, 2015. [16] g. pikra and n. rohmah, “comparison of single and double stage regenerative organic rankine cycle for medium grade heat source through energy and exergy estimation,” int. j. renew. energy dev., vol. 8, no. 2, pp. 141–148, 2019. [17] m. j. moran and h. n. shapiro, “fundamentals of engineering thermodynamics,” 6th ed. united states of america: john wiley & sons, inc., 2008. [18] k. rahbar, s. mahmoud, r.k. al-dadah, n. moazami, and s.a. mirhadizadeh, “review of organic rankine cycle for smallscale applications,” energy convers. manag., vol. 134, pp. 135– 155, 2017. [19] r. long, y.j. bao, x.m. huang, and w. liu, “exergy analysis and working fluid selection of organic rankine cycle for low grade waste heat recovery,” energy, vol. 73, pp. 475–483, 2014. [20] w. xu, s. deng, l. zhao, w. su, y. zhang, s. li, and m. ma, “how to quantitatively describe the role of the pure working fluids in subcritical organic rankine cycle : a limitation on efficiency,” energy convers. manag., vol. 172, no. may, pp. 316–327, 2018. [21] j. bao and l. zhao, “a review of working fluid and expander selections for organic rankine cycle,” renew. sustain. energy rev., vol. 24, pp. 325–342, 2013. [22] b.f. tchanche, g. lambrinos, a. frangoudakis, and g. papadakis, “low-grade heat conversion into power using organic rankine cycles – a review of various applications,” renew. sustain. energy rev., vol. 15, no. 8, pp. 3963–3979, 2011. [23] b. liu, k. chien, and c. wang, “effect of working fluids on organic rankine cycle for waste heat recovery,” energy, vol. 29, pp. 1207–1217, 2004. http://dx.doi.org/10.1016/j.energy.2017.01.151 http://dx.doi.org/10.1016/j.energy.2017.01.151 http://dx.doi.org/10.1016/j.geothermics.2016.04.002 http://dx.doi.org/10.1016/j.geothermics.2016.04.002 http://dx.doi.org/10.1016/j.geothermics.2016.04.002 http://dx.doi.org/10.1016/j.geothermics.2016.04.002 http://dx.doi.org/10.1016/j.geothermics.2016.04.002 http://dx.doi.org/10.1016/j.geothermics.2016.09.004 http://dx.doi.org/10.1016/j.geothermics.2016.09.004 http://dx.doi.org/10.1016/j.geothermics.2016.09.004 http://dx.doi.org/10.1016/j.geothermics.2016.09.004 http://dx.doi.org/10.1016/j.solener.2011.02.010 http://dx.doi.org/10.1016/j.solener.2011.02.010 http://dx.doi.org/10.1016/j.solener.2011.02.010 http://dx.doi.org/10.1016/j.solener.2011.02.010 http://dx.doi.org/10.1016/j.apor.2011.12.006 http://dx.doi.org/10.1016/j.apor.2011.12.006 http://dx.doi.org/10.1016/j.apor.2011.12.006 http://dx.doi.org/10.1016/j.enconman.2017.01.056 http://dx.doi.org/10.1016/j.enconman.2017.01.056 http://dx.doi.org/10.1016/j.enconman.2017.01.056 http://dx.doi.org/10.1016/j.enconman.2017.01.056 http://dx.doi.org/10.1016/j.enconman.2016.05.066 http://dx.doi.org/10.1016/j.enconman.2016.05.066 http://dx.doi.org/10.1016/j.enconman.2016.05.066 http://dx.doi.org/10.1016/j.energy.2016.12.081 http://dx.doi.org/10.1016/j.energy.2016.12.081 http://dx.doi.org/10.1016/j.energy.2016.12.081 http://dx.doi.org/10.1016/j.apenergy.2015.04.016 http://dx.doi.org/10.1016/j.apenergy.2015.04.016 http://dx.doi.org/10.1016/j.apenergy.2015.04.016 https://doi.org/10.1016/j.enconman.2017.12.093 https://doi.org/10.1016/j.enconman.2017.12.093 https://doi.org/10.1016/j.enconman.2017.12.093 https://doi.org/10.1016/j.enconman.2017.12.093 https://doi.org/10.1016/j.apenergy.2018.02.096 https://doi.org/10.1016/j.apenergy.2018.02.096 https://doi.org/10.1016/j.apenergy.2018.02.096 https://doi.org/10.1016/j.apenergy.2018.02.096 https://doi.org/10.1016/j.apenergy.2018.02.096 http://dx.doi.org/10.1016/j.energy.2013.06.039 http://dx.doi.org/10.1016/j.energy.2013.06.039 http://dx.doi.org/10.1016/j.energy.2013.06.039 http://dx.doi.org/10.1016/j.energy.2013.06.039 http://dx.doi.org/10.1016/j.enconman.2015.07.073 http://dx.doi.org/10.1016/j.enconman.2015.07.073 http://dx.doi.org/10.1016/j.enconman.2015.07.073 http://dx.doi.org/10.1016/j.egyr.2014.10.003 http://dx.doi.org/10.1016/j.egyr.2014.10.003 http://dx.doi.org/10.1016/j.egyr.2014.10.003 http://dx.doi.org/10.14710/ijred.8.2.141-148 http://dx.doi.org/10.14710/ijred.8.2.141-148 http://dx.doi.org/10.14710/ijred.8.2.141-148 http://dx.doi.org/10.14710/ijred.8.2.141-148 http://krodriguez.net/libros/moran.pdf http://krodriguez.net/libros/moran.pdf http://krodriguez.net/libros/moran.pdf http://dx.doi.org/10.1016/j.enconman.2016.12.023 http://dx.doi.org/10.1016/j.enconman.2016.12.023 http://dx.doi.org/10.1016/j.enconman.2016.12.023 http://dx.doi.org/10.1016/j.enconman.2016.12.023 http://dx.doi.org/10.1016/j.energy.2014.06.040 http://dx.doi.org/10.1016/j.energy.2014.06.040 http://dx.doi.org/10.1016/j.energy.2014.06.040 http://dx.doi.org/10.1016/j.enconman.2018.07.031 http://dx.doi.org/10.1016/j.enconman.2018.07.031 http://dx.doi.org/10.1016/j.enconman.2018.07.031 http://dx.doi.org/10.1016/j.enconman.2018.07.031 https://doi.org/10.1016/j.rser.2013.03.040 https://doi.org/10.1016/j.rser.2013.03.040 https://doi.org/10.1016/j.rser.2013.03.040 https://doi.org/10.1016/j.rser.2011.07.024 https://doi.org/10.1016/j.rser.2011.07.024 https://doi.org/10.1016/j.rser.2011.07.024 https://doi.org/10.1016/j.rser.2011.07.024 https://doi.org/10.1016/j.energy.2004.01.004 https://doi.org/10.1016/j.energy.2004.01.004 https://doi.org/10.1016/j.energy.2004.01.004 i. introduction ii. materials and methods iii. results and discussions a. heat input and heat loss analysis b. pump power and turbine power analysis c. net power output and thermal efficiency analysis d. exergy input and exergy loss analysis e. exergy efficiency analysis iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.93-101 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015 (sinta 2). three axis deviation analysis of cnc milling machine dalmasius ganjar subagio*, ridwan arief subekti, hendri maja saputra, ahmad rajani, kadek heri sanjaya research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi bandung, gd 20, lt 2, bandung, west java, 40135 indonesia received 24 october 2019; accepted 18 december 2019 abstract the manufacturing technology has developed rapidly, especially those intended to improve the precision. consequently, increasing precision requires greater technical capabilities in the field of measurement. a prototype of a 3-axis cnc milling machine has been designed and developed in the research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi). the cnc milling machine is driven by a 0.4 kw servo motor with a spindle rotation of 12,000 rpm. this study aims to measure the precision of the cnc milling machine by carrying out the measurement process. it is expected that the cnc milling machine will be able to perform in an optimum precision during the manufacturing process. accuracy level testing is done by measuring the deviations on the three axes namely x-axis, y-axis, and z-axis, as well as the flatness using a dial indicator and parallel plates. the measurement results show the deviation on the x-axis by 0.033 mm, the y-axis by 0.102 mm, the z-axis by 0.063 mm, and the flatness of the table by 0.096 mm, respectively. it is confirmed that the deviation value is within the tolerance standard limits set by iso 2768 standard. however, the calibration is required for this cnc milling machine to achieve more accurate precision. furthermore, the design improvement of cnc milling machine and the application of information technology in accordance with industry 4.0 concept will enhance the precision and reliability. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: precision measurement; orthogonal axes; manufacturing machine; automation industry. i. introduction since the beginning of the industrial revolution, there has been a dramatic increase in manufacturing quality and quantity by the application of industrial mechanization, from steam powered machines to modern days automation [1]. today, there is greater demand for higher quality and quantity products and services which consequently requires manufacturing complexity and better quality of machining which makes industrial equipment construction more complicated [2]. in developed countries, the slowing down of population growth and ageing population cause shortage in manpower for the industry. other common problems nowadays are the depleting natural resources and shortening product life cycle [3]. all those problems are tried to be overcome by implementing the state of the art technologies in the form of internet of things (iot) and cyber-physical system (cps) [1][4]. germany is the country which introduced the concept of industry 4.0, a concept as an embodiment of those new technologies [1]. together with japan, germany has been the leading country in developing manufacturing equipment such as computer numerical control (cnc) machine [5]. the concept will make the future industry more agile and flexible to meet a quickly and constantly changing market demands [6]. from the first introduction in 2011, the concept of industry 4.0 has been gradually studied, developed and implemented not only in europe but worldwide. the indonesian ministry of industry introduced a concept of making indonesia 4.0 in 2019 [7]. one emphasize of making indonesia 4.0 is greater automation in manufacturing technology to increase competitiveness. recently, the development and application of manufacturing industry technology in indonesia have been rapidly increasing, as evidenced by the increasingly modern equipment used to work on a product, such as a cnc machine which is a machine that has been equipped with a computer to facilitate the operation of the machine [8][9]. in a few examples, computer technology has been applied to machine * corresponding author. phone: +62-8122439283 e-mail address: dalmasius@yahoo.com https://dx.doi.org/10.14203/j.mev.2019.v10.93-101 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.93-101 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.93-101&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 94 tools including lathes, milling machines, scrap machines, and drilling machines [9][10]. the operation of the cnc machine uses a program that is controlled directly by a computer [10]. hence, the operation of cnc machine tools works by synchronizing the computer and its mechanics [9]. nowadays many industries have begun to abandon conventional machine tools and switch to using cnc machine tools. quality and productivity aspects are the basic reasons computer-based production machines are widely adopted in the manufacturing industry [11]. several attributes expected from modern cnc machine include better product quality produced in higher quantity with high speed and precision [12]. the process of synchronizing movements on the axis of motion requires an interpolator system that specifically divides the movements of each axis based on global movement commands which are manifested in the form of motion command signals to the drive system [13][14]. as technology develops, the cnc milling machine conditions must be measured to have reliable performance [14][15]. afkhamifar et al. conducted research on the analysis of variations for the cnc milling process with results were compared with iso 2768, a guidelines for general geometrical tolerances and technical drawings [16]. the study underlined that the precision of the machine can be improved either by better machine design or software development. the quality of the results of machining processes is quantified by machining performance index which includes milling accuracy and surface quality [12]. the index is affected by the integrated operations of various factors namely cad/cam, cnc controller, servo control, feed drive system, and mechanical bodies [12]. another possible effector which often neglected is probe hysteresis [17] and the subsequent deformation [18]. improving machining precision has been a widely known challenge in industry as the cnc machine is composed of various moving and rotating shafts that makes machining motion complicated [19]. with regard to milling accuracy, the vibration of the mechanical bodies, sliding motion of stick, and axial motion affect precision [12]. to solve the vibration problem, a real-time resonance signal analysis coupled with online surface quality monitoring has been proposed [20]. another study suggested kinematic modelling as a method to improve the precision of a multi axis cnc machine [19]. analyzing the complex cnc machine motion has been one of the most important subjects in industrial machining study [19]. thus, when the researchers at the research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm-lipi) developed a cnc milling machine, it is important to analyze the machine motion to measure its precision. in a previous study, zaynawi and bisono calibrated the x, y, and z-axis of the wood cnc router machine using a dial indicator and block gauge [8]. in another study, wijaya performed calibration of the yaxis to the accuracy of the workpiece on a 3-axis cnc router machine [21]. with regard to the z-axis, nayorama, and sedyono conducted a z-axis analysis on the calibration process and the movement of the cnc router machine [22]. fauzi et al. suggested that it is necessary to carry out measurements and analysis of data in every laboratory activity to make a conclusion [23]. therefore the analysis of measurement uncertainty becomes very important [22][24]. from the above-mentioned previous studies, we found out that the respective researchers calibrated the machine that has been calibrated by the manufacturer, whereas in this study, the measurement was performed on a self-designed cnc milling machine developed at rcepm-lipi. the objective of this study was to investigate the precision of the cnc milling machine developed at rcepm-lipi by measuring how much the deviation of the machine measurement on the x, y, and z-axes. the measurement of machining deviation is important in analyzing machine accuracy [25]. the results of this study will serve as the basis for the next process which is calibration, and it is expected that the cnc machine will be able to operate in optimum precision during the manufacturing process. ii. materials and methods a. straightness checking several predictive methods for cnc milling machine maintenance to improve reliability and prevent faults and unnecessary loss have been introduced [26]. the methods include reliability statistics method, physical model-based method, and data-driven method. reliability statistics method is the simplest method without any mathematical model or detailed information as the method depends on historical deviation data. the physical modelbased method uses a mathematical model to predict the internal working mechanism through degradation prediction. the data-driven method is the most complicated method which can be performed online. the method is very suitable for complex and expensive equipment manufacturing such as in the aircraft industry. the cnc milling machine developed in rcepm-lipi is a simple machine intended for an inexpensive and easy operation in small and medium enterprises. therefore the reliability statistics method was considered the most appropriate to assess its precision. the workpiece surface is said to be flat or straight if the results of the measurement of the plane on the surface are straight lines in three-dimensional space as measured by the tangential contact between the tool and the workpiece surface [27]. this means that there are no deviations both horizontally and vertically on the measurement results for a certain distance. straightness of the component surface is very important in machining such as lathes, scrap machines, milling machines, and grinding machines due to the work system requires a very precise level of straightness [28]. the skills to make the surface of the workpiece completely straight are also necessary, including how to check the straightness itself [24]. in order to measure the straightness/flatness, a straightness check of the x, y, and z-axis, as well as d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 95 levelling checks of the machine table is performed by using a dial indicator, parallel plates, and a flat table [29]. the straightness/flatness check on the machine with a dial indicator was performed to understand the magnitude of the deviation. any changes in the distance experienced by the dial indicator sensor will be designated by the pointer. in order to achieve accurate results, the measurements must be conducted on a flat working table [29]. it is necessary to insert a parallel plate/straight edge between the measuring plane and the dial indicator base to stabilize the dial indicator movement so that a change in the position of the sensor pressure on the measuring plane can be avoided. when placing the sensor on the measuring plane, the pointer should be set to zero. if the measuring plane is relatively long, it should be divided into several sections with the magnitude of the distance of each part being determined in advance. between one part with another is marked by a dot or short line/strip. at each of these points, it can be described the magnitude of the deviation from the alignment of the measuring plane. thus it can be known which parts of the measuring plane are not straight. the examples of straightness checks are shown in figure 1. the direction of the horizontal deviation is shown in figure 1 (a) and the direction of the vertical deviation is shown in figure 1 (b). figure 2 describes the deviation in the orthogonal axes, namely x-axis (x), y-axis (y), and z-axis (z). the deviation is defined as the distance between the nominal point (pn) to the measurement point (pm). measurement results and magnitude of deviations are usually illustrated in graphical form with a sign (+) for positive deviations or (-) for negative deviations. deviations marked positive or negative are based on allowed threshold values. if the inspection result turns out to exceed the allowed threshold values, it can be said that the level of straightness of the measuring object is not good or low, regardless of whether the deviation is positive or (a) (b) figure 1. straightness checking in (a) the horizontal deviation direction and (b) the vertical deviation direction figure 2. cnc milling machine deviation in the three axis (adapted from werner, 2018 [25]) d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 96 negative. an example of the results of the straightness checks in the form of a line graph is illustrated in figure 3. the above method is suitable for examining the relatively narrow side of the measuring plane and its longitudinal direction (the thick side of the measurement object). if the measuring plane is wide enough in the extended direction then the straightness check can be carried out several times in different positions according to more favourable considerations in the measurement process. therefore, the examination is not only on one line but can be more than one line [23]. b. object specifications, instruments, and measurement methods the measurement object is a prototype 3-axis cnc milling machine developed by rcepm-lipi (figure 4). this cnc milling machine has the following specifications:  maximum spindle speed = 12,000 rpm.  stroke of the x-axis = 180 mm, y-axis = 160 mm and z-axis = 200 mm.  servo motor power used for x, y, and z axes = 400 w.  the maximum diameter of the chisel can be used on a spindle = 6 mm.  maximum workpiece material = aluminium. while the equipment used in this measurement process is as follows:  parallel plates or flat part of the machine on the horizontal and vertical sides.  clamping.  dial indicator with a level of accuracy of 0.05 mm. dial indicator or dial gauge is used to measure bending, run out, slackness, end play, backlash, and flatness. inside the dial indicator, there is a mechanism that can magnify the small movements. when the spindle moves along the measured surface, the movement is enlarged by a magnifying mechanism and indicated by the pointer. the procedure for using the dial indicator is as follows:  the spindle dial indicator position must be perpendicular to the measured surface.  the line of imagination from the measuring eye to the pointer must be perpendicular to the dial indicator surface while reading the measurement results.  the dial indicator must be installed carefully mounted on the supporting rod, meaning that the dial indicator must not shake.  turn the outer ring and set it to zero. move the spindle up and down, then check that the pointer always returns to zero after the spindle is released.  observe and record the changes that occur in the indicator dial pointer for each measurement point, which is every 15 mm. figure 3. the results of the surface straightness check of the measurement object using the dial indicator 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 series2 0,35 0,3 0,45 0,5 0 0,1 -0,7 -0,8 -1 0,5 0,45 0,6 -0,5 0,5 0,75 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5 d e v ia ti o n s (m m ) measurement points figure 4. the prototype of 3-axis cnc milling machine developed at rcepm-lipi d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 97 if the measurement has been completed up to 13 times or the last point, then return the dial indicator position to its original position by moving in the direction of the x-axis, y-axis, or z-axis being measured. iii. results and discussions a. x-axis measurements the measurement process on the cnc milling machine designed and developed at rcepm-lipi was carried out on its three axes, namely the x, y, and z axes. the data collection scheme on the x-axis is shown in figure 5. x-axis measurement was carried out 3 times where each process was performed by measuring 12 measurement points. the x-axis measurement results are displayed in tabular and graphical form as shown in table 1 and figure 6. table 1 and figure 6 show that the maximum deviation on the x axis is -0.183 mm at the second test point. the smallest deviation is at the testing points 1 and 9 that are -0,017 mm. the average deviation is -0,033 mm. the minus sign means the measured area is away from the indicator needle while the positive sign means the measured field is close to the indicator needle. compared with previous studies, the results in this study were lower than a study by afkhamifar et al. whose x-axis position error was 0.134 mm at average value [16] and within the range of acceptable deviation which a reference suggested between -0.030 mm to +0.045 mm [25]. however compared to the higher precision of cnc machine with laser measurement system, the average deviation is higher [24]. b. y-axis measurements the process of measuring a cnc milling machine using the indicator dial on the y-axis is illustrated in figure 7. y-axis measurement was carried out 3 times where each measurement was performed on 10 points. y-axis measurement results are shown in table 2 and figure 8. as described in table 2 and figure 8, the maximum deviation on the y axis is 0,300 mm at the fourth test point. the smallest deviation is at the second test point of -0,033 mm. the average deviation is -0,102 mm. the minus sign means the measured area is away from the indicator needle, while the positive sign means the measured field is close to the indicator needle. the deviation in y-axis is greater than the previous studies which reported an average deviation on y-axis is 0.056 mm [16]. figure 6. x-axis deviation graph -0,200 -0,150 -0,100 -0,050 0,000 0,050 0,100 0 1 5 3 0 4 5 6 0 7 5 9 0 1 0 5 1 2 0 1 3 5 1 5 0 1 6 5 1 8 0 d e v ia ti o n s o n t h e x a xi s (m m ) measurement distance (mm) figure 7. the deviation measurement scheme on the y-axis [10] figure 5. the deviation measurement scheme on the x-axis [10] d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 98 c. z-axis measurements the measurement scheme of the cnc milling machine on the z-axis is illustrated in figure 9. the measurements on the z-axis were carried out 3 times wherein each process measurements were made of 10 points. the z-axis measurement results are shown in table 3 and figure 10. table 3 and figure 10 present the measurement results of the deviation on the z-axis. the maximum deviation on the z-axis is -0.233 mm at the sixth point test. the smallest deviation is at the ninth test point which is equal to 0 mm. the average deviation is 0,063 mm. a minus sign means the measured area is away from the indicator needle, while the positive sign means the measured field is close to the indicator needle. the average deviation of the z-axis is larger than the previous study which resulted in a deviation on the z-axis of -0.021 mm [16], and much larger than the previous study using laser measuring system whose largest deviation on the z-axis is only 0.004 mm [24]. d. flatness of the machine base table in addition to measuring the straightness of the three working axes of the cnc milling machine designed at rcepm-lipi, a measurement process was also carried out on the flat table base of the machine. the scheme that shows data collection from the measurement of the flatness of the machine table is depicted in figure 11. the measurement of the machine table flatness was also carried out 3 times with each process measuring 10 points. the cnc milling machine table measurement results are shown in table 4 and figure 12. table 4 and figure 12 show that the maximum deviation on the x axis is -0.217 mm at the eleventh point test of 165 mm measurement distance. the smallest deviation is at the third test point at a measurement distance of 45 mm which is equal to 0.033 mm. the average deviation is -0.096 mm. a minus sign means the measured area is away from the indicator needle, while the positive sign means the measured field is close to the indicator needle. figure 8. y-axis deviation graph -0,350 -0,300 -0,250 -0,200 -0,150 -0,100 -0,050 0,000 0,050 0,100 0 15 30 45 60 75 90 105 120 135 150 d e v ia ti o n s o n t h e y -a xi s (m m ) measurement distance (mm) table 1. x-axis measurements results no measurement distance (mm) deviations (mm) average deviation (mm) 1 2 3 0 0,00 0,00 0,00 0,000 1 15 -0,15 0,20 -0,10 -0,017 2 30 -0,30 -0,15 -0,10 -0,183 3 45 0,25 0,15 -0,20 0,067 4 60 -0,15 0,10 -0,10 -0,050 5 75 -0,10 -0,15 -0,10 -0,117 6 90 -0,15 0,10 0,15 0,033 7 105 0,10 -0,10 -0,10 -0,033 8 120 -0,10 0,15 -0,15 -0,033 9 135 -0,15 0,20 -0,10 -0,017 10 150 -0,20 0,20 -0,10 -0,033 11 165 -0,15 -0,15 0,15 -0,050 12 180 0,10 0,10 -0,10 0,033 average -0,033 table 2. y-axis measurements results no measurement distance (mm) deviations (mm) average deviation (mm) 1 2 3 0 0,00 0,00 0,00 0,000 1 15 -0,20 0,40 -0,30 -0,033 2 30 -0,20 -0,10 -0,25 -0,183 3 45 0,20 0,15 -0,15 0,067 4 60 -0,25 -0,25 -0,40 -0,300 5 75 -0,15 -0,25 -0,25 -0,217 6 90 -0,35 0,25 0,25 0,050 7 105 0,20 -0,25 -0,15 -0,067 8 120 -0,15 0,15 -0,35 -0,117 9 135 -0,35 0,20 -0,25 -0,133 10 150 -0,25 0,20 -0,20 -0,083 average -0,102 d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 99 from the x, y, z, and flatness measurements, it is known that the deviation values: the average x axis deviation is -0.033 mm, y -0.102 mm axis, z -0,063 mm, and -0.096 mm flatness, respectively. the value of the deviation is still within the limits of the tolerance standard set at iso 2768. these results are almost the same compared to previous studies conducted by afkhamifar et al. where in his research it was found that the results of the x, y, and z axis deviations were 0.134 mm, 0.056 mm, and -0.021 mm, respectively [16]. while the results are acceptable based on iso 2768 standard, the deviation at y-axis and z-axis are relatively greater than the comparable previous study which indicates an improvement for the developed cnc milling machine is necessary. there are several possible causes which resulted in inaccuracies in this study as suggested by the previous study [16]. the first possibility comes from the machine table which plays a role as a base. the second possibility comes from the upper body of the machine. the third possibility comes from the head and the last possibility comes from the interaction between the base and the workpiece. these shortcomings require a better machine design as suggested by the previous study [16]. other solutions include a better software implementation [16][29], more complex yet reliable mathematical modelling [30], or more precise sensors such as real-time vibration monitoring [20], transducer in a kinematic probe [17], or laser measurement systems [24]. furthermore, as a technology driven product research, the design and development phase of cnc milling machine often overlook the interdisciplinary approach, especially from industrial and human factors studies [31]. the machine design without consideration of the human factors often leads to human error and operation faults in addition to the limited technical performance of machine technology. figure 10. z-axis deviation graph -0,250 -0,200 -0,150 -0,100 -0,050 0,000 0,050 0,100 0 15 30 45 60 75 90 105 120 135 150 d e v ia ti o n s o n t h e z -a xi s (m m ) measurement distance (mm) figure 11. test scheme on the machine table figure 9. the deviation measurement scheme on the z-axis [10] d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 100 iv. conclusion the measurement results of the cnc milling machine developed at rcepm-lipi in bandung show that the cnc milling machines have deviations on each axis, including the x-axis of 0.033 mm, the yaxis of 0.102 mm, the z-axis of 0.063 mm, and flatness of the table 0.096 mm, respectively. the results are within the acceptable performance limits required by iso 2768. based on these measurements, this cnc milling machine can be used for machining work processes that can move together on 3 axes namely x, y, and z axes where the machine can be used to make components that have tolerances above 0.1 mm. however, future manufacturing needs may require higher precision and the developed cnc milling machine still has quite high inaccuracy compared to some previous studies. the application of industry 4.0 concept as well as more sophisticated sensors, mathematical modelling, data processing, and software are necessary for future study. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] j. qin, y. liu, and r. grosvenor, "a categorical framework of manufacturing for industry 4.0 and beyond," in procedia cirp, vol. 52, pp. 173-178, 2016. [2] z. li, y. wang, and k. s. wang, "intelligent predictive maintenance for fault diagnosis and prognosis in machine figure 12. machine table flatness deviation graph table 3. z-axis measurements results no measurement distance (mm) deviations (mm) average deviation (mm) 1 2 3 0 0,00 0,00 0,00 0,000 1 20 0,15 -0,15 0,10 0,033 2 40 -0,10 -0,10 -0,20 -0,133 3 60 -0,15 -0,15 -0,20 -0,167 4 80 0,25 -0,15 -0,20 -0,033 5 100 -0,15 -0,25 -0,25 -0,217 6 120 -0,20 -0,25 -0,25 -0,233 7 140 -0,15 0,15 0,20 0,067 8 160 0,15 -0,15 0,20 0,067 9 180 0,10 0,15 -0,25 0,000 10 200 -0,15 0,25 -0,15 -0,017 average -0,063 table 4. machine table flatness measurement results no measurement distance (mm) deviations (mm) average deviation (mm) 1 2 3 0 0,00 0,00 0,00 0,000 1 20 0,15 -0,15 0,10 0,033 2 40 -0,10 -0,10 -0,20 -0,133 3 60 -0,15 -0,15 -0,20 -0,167 4 80 0,25 -0,15 -0,20 -0,033 5 100 -0,15 -0,25 -0,25 -0,217 6 120 -0,20 -0,25 -0,25 -0,233 7 140 -0,15 0,15 0,20 0,067 8 160 0,15 -0,15 0,20 0,067 9 180 0,10 0,15 -0,25 0,000 10 200 -0,15 0,25 -0,15 -0,017 average -0,063 -0,250 -0,200 -0,150 -0,100 -0,050 0,000 0,050 0,100 0,150 0,200 0 15 30 45 60 75 90 105 120 135 150 fl a tn e ss o f th e m a ch in e t a b le ( m m ) measurement distance (mm) https://doi.org/10.1016/j.procir.2016.08.005 https://doi.org/10.1016/j.procir.2016.08.005 https://doi.org/10.1016/j.procir.2016.08.005 https://doi.org/10.1007/s40436-017-0203-8 https://doi.org/10.1007/s40436-017-0203-8 d. g. subagio et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 93-101 101 centers: industry 4.0 scenario," adv. manuf., vol. 5, no. 4, pp. 377-387, 2017. [3] l. li, c. li, y. tang, and q. yi, "influence factors and operational strategies for energy efficiency improvement of cnc machining," j. clean. prod., vol. 161, pp. 220-238, 2017. [4] b. bagheri, s. yang, h. a. kao, and j. lee, "cyber-physical systems architecture for self-aware machines in industry 4.0 environment," in ifac-papersonline, 2015, vol. 28, no. 3, pp. 1622-1627. [5] t. k. sung and b. carlsson, "the evolution of a technological system: the case of cnc machine tools in korea," j. evol. econ., vol. 13, no. 4, pp. 435-460, 2003. [6] a. theorin et al., "an event-driven manufacturing information system architecture for industry 4.0," int. j. prod. res., vol. 55, no. 5, pp. 1297-1311, 2017. [7] i. m. of industry, "making indonesia 4.0," 2019. [8] zaynawi, b. wiro. k, and f. bisono, "proses kalibrasi sumbu x, y, dan z pada mesin cnc router kayu 3 axis menggunakan alat bantu dial indicator dan block gauge " in 1st conference on design and manufacture and its aplication, pp. 350-356, 2018. [9] p. saputra, a. muqorobin, a. santoso, and t. p. purwanto, "desain dan implementasi sistem kendali cnc router menggunakan pc untuk flame cutting machine," j. mechatronics, electr. power, veh. technol., vol. 2, no. 1, p. 41, 2012. [10] m. amala and s. a. widyanto,. "pengembangan perangkat lunak sistem operasi mesin milling cnc trainer," j. tek. mesin, vol. 2, no. 3, pp. 204-210, 2014. [11] e. y. elvys and sirama, "peningkatan keakurasian gerakan pada protoype mesin cnc milling 3-axis," proceeding semin. nas. tah. tek. mesin xiv, (snttm xiv), pp. 7-8, 2015. [12] h. w. chiu and c. h. lee, "prediction of machining accuracy and surface quality for cnc machine tools using data driven approach," adv. eng. softw., vol. 114, pp. 246-257, 2017. [13] h. yanuar, a. syarief, and a. kusairi, "pengaruh variasi kecepatan potong dan kedalaman pemakanan terhadap kekasaran permukaan dengan berbagai media pendingin pada proses frais konvensional," tek. mesin unlam, vol. 03, no. 1, pp. 27-33, 2014. [14] syahriza, t. firsa, and m. ibrahim, "rancang bangun mesin cnc 4 axis berbasis pc (personal computer)," j. tek. mesin unsyiah, vol. 3, no. 2, pp. 75-79, 2015. [15] hendra, sutarmadi, a. indriani, and hernadewita, "jenis material pahat potong dan run out terhadap kekasaran permukaan benda kerja silinder pada proses bubut," j. mek., vol. 4, no. 2, pp. 376-385, 2013. [16] a. afkhamifar, d. antonelli, and p. chiabert, "variational analysis for cnc milling process," in procedia cirp, vol. 43, pp. 118-123, 2016. [17] a. wozniak and m. jankowski, “variable speed compensation method of errors of probes for cnc machine tools,” precis. eng., vol. 49, pp. 316–321, 2017. [18] d. wu et al., "machining fixture for adaptive cnc machining process of near-net-shaped jet engine blade," chinese j. aeronaut., 2019. [19] b. yang, g. zhang, y. ran, and h. yu,"kinematic modeling and machining precision analysis of multi-axis cnc machine tools based on screw theory," mech. mach. theory, vol. 140, pp. 538552, 2019. [20] e. garcía plaza, p. j. núñez lópez, and e. m. beamud gonzález, "efficiency of vibration signal feature extraction for surface finish monitoring in cnc machining," j. manuf. process., vol. 44, pp. 145-157, 2019. [21] f. w. putra, "kalibrasi sumbu y terhadap ketelitian benda kerja pada mesin cnc router 3 axis," 2016. [22] f. n. w.k, "naskah publikasi analisa sumbu z pada proses kalibrasi dan pergerakan mesin cnc router," universitas muhammadiyah surakarta (ums), 2016. [23] a. fauzi, e. wiyono, and s. budiawanti, "pengembangan model praktikum fisika berbasis analisis ketidakpastian pengukuran," j. mater. dan pembelajaran fis., vol. 3, no. 2, pp. 27-32, issn: 2089-6158, 2013. [24] s. ekinovic, h. prcanovic, and e. begovic, "calibration of machine tools by means of laser measuring systems,"” asian trans. eng., vol. 02, no. 06, pp. 17-21, 2013. [25] a. werner, "improving the accuracy of free-form surface machining on cnc milling machines," mechanik, vol. 91, no. 12, pp. 1100–1103, 2018. [26] c. ahilan, s. kumanan, n. sivakumaran, and j. edwin raja dhas, “modeling and prediction of machining quality in cnc turning process using intelligent hybrid decision making tools,” appl. soft comput. j., vol. 13, no. 3, pp. 1543–1551, 2013. [27] g. l. samuel and m. s. shunmugam, “evaluation of straightness and flatness error using computational geometric techniques,” comput. des., vol. 31, pp. 829–843, 1999. [28] v. p. astakhov, “machining of hard materials definitions and industrial applications,” in machining of hard materials, london: springer, pp. 1–32, 2011. [29] j.-s. chen, "computer-aided accuracy enhancement," int. j. mach. tools manuf., vol. 35, no. 4, pp. 593-605, 1995. [30] l. mironova and l. kondratenko, "mathematical modeling of the processing of holes on cnc machines," in materials today: proceedings, vol. 19, pp. 2354-2357, 2019. [31] x. yang, x. zhou, and k. cheng, "research on morphology and semantics of industrial design for cnc machine tools," in procedia manufacturing, vol. 17, pp. 379-386, 2018. https://doi.org/10.1007/s40436-017-0203-8 https://doi.org/10.1007/s40436-017-0203-8 https://doi.org/10.1016/j.jclepro.2017.05.084 https://doi.org/10.1016/j.jclepro.2017.05.084 https://doi.org/10.1016/j.jclepro.2017.05.084 https://doi.org/10.1016/j.ifacol.2015.06.318 https://doi.org/10.1016/j.ifacol.2015.06.318 https://doi.org/10.1016/j.ifacol.2015.06.318 https://doi.org/10.1016/j.ifacol.2015.06.318 https://doi.org/10.1007/s00191-003-0160-1 https://doi.org/10.1007/s00191-003-0160-1 https://doi.org/10.1007/s00191-003-0160-1 https://doi.org/10.1080/00207543.2016.1201604 https://doi.org/10.1080/00207543.2016.1201604 https://doi.org/10.1080/00207543.2016.1201604 https://kemenperin.go.id/download/18449 https://journal.ppns.ac.id/index.php/cdma/article/view/341 https://journal.ppns.ac.id/index.php/cdma/article/view/341 https://journal.ppns.ac.id/index.php/cdma/article/view/341 https://journal.ppns.ac.id/index.php/cdma/article/view/341 http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 http://dx.doi.org/10.14203/j.mev.2011.v2.41-50 https://ejournal3.undip.ac.id/index.php/jtm/article/view/9613 https://ejournal3.undip.ac.id/index.php/jtm/article/view/9613 https://ejournal3.undip.ac.id/index.php/jtm/article/view/9613 http://prosiding.bkstm.org/prosiding/2015/man-12.pdf http://prosiding.bkstm.org/prosiding/2015/man-12.pdf http://prosiding.bkstm.org/prosiding/2015/man-12.pdf https://doi.org/10.1016/j.advengsoft.2017.07.008 https://doi.org/10.1016/j.advengsoft.2017.07.008 https://doi.org/10.1016/j.advengsoft.2017.07.008 http://eprints.unlam.ac.id/id/eprint/314 http://eprints.unlam.ac.id/id/eprint/314 http://eprints.unlam.ac.id/id/eprint/314 http://eprints.unlam.ac.id/id/eprint/314 http://eprints.unlam.ac.id/id/eprint/314 http://www.rp2u.unsyiah.ac.id/index.php/welcome/prosesdownload/8689/4 http://www.rp2u.unsyiah.ac.id/index.php/welcome/prosesdownload/8689/4 http://www.rp2u.unsyiah.ac.id/index.php/welcome/prosesdownload/8689/4 http://jurnal.untad.ac.id/jurnal/index.php/mekanikal/article/view/2175 http://jurnal.untad.ac.id/jurnal/index.php/mekanikal/article/view/2175 http://jurnal.untad.ac.id/jurnal/index.php/mekanikal/article/view/2175 http://jurnal.untad.ac.id/jurnal/index.php/mekanikal/article/view/2175 https://doi.org/10.1016/j.procir.2016.02.164 https://doi.org/10.1016/j.procir.2016.02.164 https://doi.org/10.1016/j.procir.2016.02.164 https://doi.org/10.1016/j.measurement.2020.107568 https://doi.org/10.1016/j.measurement.2020.107568 https://doi.org/10.1016/j.measurement.2020.107568 https://doi.org/10.1016/j.cja.2019.06.008 https://doi.org/10.1016/j.cja.2019.06.008 https://doi.org/10.1016/j.cja.2019.06.008 https://doi.org/10.1016/j.mechmachtheory.2019.06.021 https://doi.org/10.1016/j.mechmachtheory.2019.06.021 https://doi.org/10.1016/j.mechmachtheory.2019.06.021 https://doi.org/10.1016/j.mechmachtheory.2019.06.021 https://doi.org/10.1016/j.jmapro.2019.05.046 https://doi.org/10.1016/j.jmapro.2019.05.046 https://doi.org/10.1016/j.jmapro.2019.05.046 https://doi.org/10.1016/j.jmapro.2019.05.046 http://eprints.ums.ac.id/44377/1/naskah%20publikasi.pdf http://eprints.ums.ac.id/44377/1/naskah%20publikasi.pdf http://eprints.ums.ac.id/45997/29/naskah%20publikasi-32.pdf http://eprints.ums.ac.id/45997/29/naskah%20publikasi-32.pdf http://eprints.ums.ac.id/45997/29/naskah%20publikasi-32.pdf http://jurnal.fkip.uns.ac.id/index.php/fisika/article/view/5539 http://jurnal.fkip.uns.ac.id/index.php/fisika/article/view/5539 http://jurnal.fkip.uns.ac.id/index.php/fisika/article/view/5539 http://jurnal.fkip.uns.ac.id/index.php/fisika/article/view/5539 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.682.2731&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.682.2731&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.682.2731&rep=rep1&type=pdf https://doi.org/10.17814/mechanik.2018.12.195 https://doi.org/10.17814/mechanik.2018.12.195 https://doi.org/10.17814/mechanik.2018.12.195 https://doi.org/10.1016/j.rcim.2020.101974 https://doi.org/10.1016/j.rcim.2020.101974 https://doi.org/10.1016/j.rcim.2020.101974 https://doi.org/10.1016/j.rcim.2020.101974 https://doi.org/10.1016/j.precisioneng.2019.11.015 https://doi.org/10.1016/j.precisioneng.2019.11.015 https://doi.org/10.1016/j.precisioneng.2019.11.015 https://doi.org/10.1016/j.measurement.2019.107421 https://doi.org/10.1016/j.measurement.2019.107421 https://doi.org/10.1016/j.measurement.2019.107421 https://doi.org/10.1016/0890-6955(94)p4352-u https://doi.org/10.1016/0890-6955(94)p4352-u https://doi.org/10.1016/j.matpr.2019.07.691 https://doi.org/10.1016/j.matpr.2019.07.691 https://doi.org/10.1016/j.matpr.2019.07.691 https://doi.org/10.1016/j.promfg.2018.10.060 https://doi.org/10.1016/j.promfg.2018.10.060 https://doi.org/10.1016/j.promfg.2018.10.060 mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.ph p/mev/login need a username/password? go to registration at: http://mevjournal.com/index.ph p/mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 editor-in-chief dr. haznan abimanyu dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia asscociate editors (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 © 2020 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, six papers are published with the authors diversity came from indonesia, malaysia, republic of korea, japan, saudi arabia and germany. the papers come from multidisciplinary topics including mechatronics, electrical power, and vehicular technology. they may be classified as follows. four papers fall in electrical power topics. the first paper presents wireless power transfer. the second paper proposes single-stage regenerative organic rankine cycle (orc) performance byopen feed organic heater (ofoh). the third paper has the aim to deliver predictions of rotor tip displacement in the microturbine rotor assembly supported by a journal bearing under non-linear vibrations. the fourth paper describes lux and current analysis on lab-scale smart grid system using fuzzy-logic controller. one paper is related to mechatronics which address the swarm behaviour applied to drive a system consisting of six uav quadrotors as agents for flocking while tracking a swarm trajectory. one paper deals with vehicular technology i.e. a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system. since the first volume, our journal provides discretion in financial term by waiving the article processing charge. we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2020 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 ii list of contents swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm endra joelianto, daniel christian, agus samsi ......................................................................................... 1-10 lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller bayu prasetyo, faiz syaikhoni aziz, anik nur handayani, ari priharta, adi izhar bin che ani ....................................................................................................................................................................... 11-21 preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer aam muharam, tarek mahmoud mostafa, suziana ahmad, mitsuru masuda, daiki obara, reiji hattori, abdul hapid ............................................................................................................................. 22-29 open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance ghalya pikra, nur rohmah, rakhmad indra pramana, andri joko purwanto ................................ 30-37 rotordynamics analysis of solar hybrid microturbine for concentrated solar power maulana arifin ................................................................................................................................................. 38-44 a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system muhammad khristamto aditya wardana, ocktaeck lim .................................................................... 45-54 complete articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 11, issue 1, 2020 abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. endra joelianto a, c, daniel christian b, agus samsi c (a instrumentation and control research group, institut teknologi bandung, indonesia; b externship researcher of engineering physics study program, institut teknologi bandung, indonesia; c engineering physics study program, institut teknologi bandung, indonesia) swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 1-10, 7 ill, 1 tab, 36 ref. unmanned aerial vehicle (uav) quadrotors have developed rapidly and continue to advance together with the development of new supporting technologies. however, the use of one quadrotor has many obstacles and compromises the ability of a uav to complete complex missions that require the cooperation of more than one quadrotor. in nature, one interesting phenomenon is the behavior of several organisms to always move in flocks (swarm), which allows them to find food more quickly and sustain life compared with when they move independently. in this paper, the swarm behavior is applied to drive a system consisting of six uav quadrotors as agents for flocking while tracking a swarm trajectory. the swarm control system is expected to minimize an objective function of the energy used and tracking errors. the considered swarm control system consists of two levels. the first higher level is a proportional – derivative type controller that produces the swarm trajectory to be followed by uav quadrotor agents in swarming. in the second lower level, a linear quadratic regulator (lqr) is used by each uav quadrotor agent to follow a tracking path well with minimal objective function. a genetic algorithm is applied to find the optimal lqr weighting matrices as it is able to solve complex optimization problems. simulation results indicate that the quadrotors' tracking performance improved by 36.00 %, whereas their swarming performance improved by 17.17 %. (author) keywords: unmanned aerial vehicle; quadrotor model; swarm model; proportional – derivative (pd) controller; linear quadratic regulator (lqr); optimization model; genetic algorithm. bayu prasetyo a, faiz syaikhoni aziz a, anik nur handayani a , ari priharta a, adi izhar bin che ani b (a electrical engineering department, universitas negeri malang, indonesia; b faculty of electrical engineering, universiti teknologi mara (uitm), malaysia) lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 11-21, 14 ill, 7 tab, 15 ref. the increasing need for electrical energy requires suppliers to innovate in developing electric distribution systems that are better in terms of quality and affordability. in its development, it is necessary to have a control that can combine the electricity network from renewable energy and the main network by means of voltage back-up or synchronization automatically. the purpose of this research is to create an innovative lux and current analysis on lab-scale smart grid system using fuzzy logic controller to control the main network, solar panel network and generator network to supply each other with lab-scale electrical energy. in the control, mamdani fuzzy logic controller method is used as the basis for determining the smart grid system control problem solving by adjusting the current conditions on the main network and the light intensity conditions on the ldr sensor. current conditions are classified in three conditions namely safe, warning, and trip. meanwhile, the light intensity conditions are classified in three conditions namely dark, cloudy and bright. from the test results, the utility grid (pln) is in active conditions when the load current is 0.4 a (safe) and light intensity is 1,167 lux (dark). then the pln + pv condition is active when the load current is 1.37 (warning) and the light intensity is 8,680 lux (bright). finally, the generator condition is active when the load current is 1.6 (trip) and the light intensity is 8,680 (bright). based on the test results, it is known that the system can work to determine which source is more efficient based on the parameters obtained. (author) keywords: fuzzy logic; smart grid; lux and current; labscale. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv aam muharam a, b, tarek mahmoud mostafa c, suziana ahmad a, d, mitsuru masuda e, daiki obara e, reiji hattori a, abdul hapid b (a applied science for electronics and materials, interdisciplinary graduate school of engineering sciences, kyushu university, japan; b research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; c computer, electrical, mathematical sciences and engineering (cemse), king abdullah university of science and technology, saudi arabia; d faculty of electrical and electronic engineering technology (ftkee), universiti teknikal malaysia melaka, malaysia; e automotive products and electronics laboratories, furukawa electric co., ltd., japan) preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 22-29, 12 ill, 2 tab, 20 ref. a preliminary study of class-e radio frequency power amplifier for wireless capacitive power transfer (cpt) system is presented in this paper. due to a limitation in coupling capacitance value, a high frequency operation of switching power inverter is necessary for the cpt system. a gan mosfet offers reliability and performance in a high frequency operation with an improved efficiency over silicon device. design specification related to the parallel load parameter, lc impedance matching and experimental analysis of the amplifier is explored. an experimental setup for the proposed inverter and its integration with the cpt system is provided, and the power efficiency is investigated. as a result, by utilizing a 6.78 mhz resonant frequency and a 50 ω resistive load, 50 w of power has been transmitted successfully with an end to end system efficiency over 81 %. additionally, above 17 w wireless power transfer was demonstrated successfully in the cpt system under 6 pf coupling with the efficiency over 70 %. (author) keywords: class-e power amplifier; wireless power transfer; capacitive power transfer; high efficiency; high frequency power source. ghalya pikra a, nur rohmah b, rakhmad indra pramana a, andri joko purwanto a (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b research unit for clean technology, indonesian institute of sciences) open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 30-37, 8 ill, 1 tab, 23 ref. single-stage regenerative organic rankine cycle (ssrorc) is a system that is used for increasing the simple organic rankine cycle (orc) performance. open feed organic heater (ofoh) addition in the orc system increase power and efficiency of the system. this paper analyzes the ssrorc performance with a variation of p6/p1 ranges from 1.25 to 3.75 with an increment of 0.25, where p6 is the ofoh pressure at the inlet side and p1 is the pressure at the inlet pump 1, respectively. hot water was used as the heat source with 100 °c and 100 l/min of temperature and volume flow rate as the initial data. r227ea, r245fa, and r141b were chosen as working fluids for performance analysis. the analysis was performed by calculating the heat input, heat loss, pump and turbine power, net power, and thermal efficiency through energy balance. exergy input, exergy output, and exergy efficiency were analyzed through exergy balance. the results show that p6/p1 = 2 obtains the highest performance than the other pressure ratios for r227ea, while r245fa and r141b obtain the highest performance at p6/p1 = 2.25. r141b has better performance than the other two fluids with 10.97 % and 11.96 % of thermal and exergy efficiency. the results show that the ratio of ofoh pressure at the inlet side to the pressure at inlet pump 1 (p6/p1) in the middle value obtains the best performance. (author) keywords: single-stage regenerative organic rankine cycle; open feed organic heater; r227ea; r245fa; r141b. maulana arifin a,b (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b institute of thermal turbomachinery and machinery laboratory, university of stuttgart, germany) rotordynamics analysis of solar hybrid microturbine for concentrated solar power journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 38-44, 6 ill, 1 tab, 15 ref. microturbine based on a parabolic dish solar concentrator runs at high speed and has large amplitudes of subsynchronous turbo-shaft motion due to the direct normal irradiance (dni) fluctuation in daily operation. a detailed rotordynamics model coupled to a full fluid film radial or journal bearing model needs to be addressed for increasing performance and to ensure safe operating conditions. the present paper delivers predictions of rotor tip displacement in the microturbine rotor assembly supported by a journal bearing under non-linear vibrations. the rotor assembly operates at 72 krpm on the design speed and delivers a 40 kw power output with the turbine inlet temperature is about 950 °c. the turbo-shaft oil temperature range is between 50 °c to 90 °c. the vibrations on the tip radial compressor and turbine were presented and evaluated in the commercial software gt-suite environment. the microturbine rotors assembly model shows good results in predicting maximum tip displacement at the rotors with respect to the frequency and time domain. (author) keywords: microturbines rotor tip displacement; parabolic dish solar concentrator; rotordynamics model; journal bearing; non-linear vibration. muhammad khristamto aditya wardana a, b, ocktaeck lim a (a department of mechanical engineering, university of ulsan, republic of korea; b research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia) a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system journal of mechatronics, electrical power, and vehicular technology, july 2020, vol. 11, no. 1, p. 45-54, 9 ill, 3 tab, 17 ref. diesel engines are commonly used for public transportation on-road and off-road applications. growth production of the diesel engine is very significant from year to year. nitride oxide (nox) from diesel engine was the one of the major sources of the air pollution. selective catalytic reduction (scr) has been successfully used to reduce nox from diesel engine with chemical reaction from ammonia (nh3). the mixing reaction between nox and nh3 reaction can produce steam (h2o) and nitrogen (n2). however, ammonia uniformity pattern usualy not homogenization journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v and the ammonia was difficult to mix with nox. the constant air flows incomplete to assist the spray injector to spread nh3 to all corners of scr. the impact study of turbulent phenomena and standard k-epsilon lowreynolds number model to mixing process in scr system using starccm+. the simulation studies are conducted under different pressure (4 to 6 bars), injection rate (0.04 g/s) and temperature (338 k – 553 k) and the high pressure and high velocity magnitude creating turbulent swirl flow. the ammonia decomposition process and mixing process with nox were investigated using box with optical access. the simulation and numerical study results validated using back pressure value and the distribution of nox concentration value from the catalyst outlet. the wall temperature will increase the urea evaporation to generate ammonia and gas pressure will increase the mixing process and chemical process in scr system. these reactions enable to optimize the scr system technology which eventually able to reduce the nox quantity from diesel engine. (author) keywords: diesel engine; wall temperature; wall impingement; urea water solution (uws); urea injection; selective catalytic reduction (scr). foreword from editor-in-chief list of contents mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia aji prasetya wibawa, ph.d. department of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. yusie rizal, phd cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. laksono kurnianggoro laksono kurnianggoro, ph.d department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia suprapto, ph.d departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. phh. mustafa no. 23, bandung, jawa barat, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an art icle in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted.  heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot.  heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot.  heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket  heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket.  heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list her e those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvii instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points:  make sure you use uniform lettering and sizing of your original artwork.  preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier.  number the illustrations according to their sequence in the text.  use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below):  eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xviii  tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi.  tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi.  tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not:  supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low.  supply files that are too low in resolution.  submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure tha t the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows  book: author, title. edition, editor , city, state or country: publisher, year, pages.  part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages.  periodical: author, “title”, journal, volume (issue), pages, month, year.  proceeding: author, “title”, in proceeding, year, pages.  unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year.  paten/standart: author, “title”, patent number, month day, year.  technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows:  book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file.  periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file.  papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file.  reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. mev journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 24–28 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.24-28 2088-6985 / 2087-3379 ©2019 research centre for electrical power an d mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture widiyanti a, *, muhammad alfian mizar a, christian asri wicaksana b, didik nurhadi a, kriya mateeke moses c a department of mechanical engineering, state university of malan g jl. semarang no. 5, malang, 65145, indonesia, b bachelor program, department of mechanical engineering, state university of malang jl. semarang no. 5, malang, 65145, indonesia, c graduate school of technological and vocational education, national yunlin university of science and technology, 123 university road, section 3, douliou, yunlin, 64002, taiwan received 9 december 2018; accepted 15 august 2019; published online 17 december 2019 abstract one of the viable solutions to the fossil fuel energy crisis was to seek alternative sources of environmentally friendly energy with the same or better quality such as bioethanol. it was possible to produce bioethanol from organic waste, e.g., corncob. this research aimed to obtain the lowest exhaust emission levels of co and co2 generated from a gasoline motor that used a mixture of bioethanol containing 96 % corncob and ron 90 fuel. this research was experimental using anova statistical data analysis method. the results showed that the lowest average of co emissions was 0.177 vol% using e100 fuel, and the highest average was 2.649 vol% using 100 % ron 90 fuel, displaying a significant difference. the lowest average of co2 emissions was 6.6 vol% using e100 fuel, and the highest was 7.51 vol% using 100 % ron 90 fuel, which was insignificantly different. the mixture variation with the lowest co and co2 emissions was e100. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: ron 90 fuel; corncob-based bioethanol; gasoline generator; co and co2 exhaust emissions. i. introduction waste is a result of various operations of production and consumption to satisfy human needs. physically, there are three types of waste: gas, solid, and liquid. organic waste is the most produced waste globally, particularly in east asia and the pacific, reaching up to 62 % [1][2]. an example of organic solid waste without optimal handling is corncob. corncob is the core of the female floral organ to which the kernels are attached. corncobs have low utility and economic value because they are most beneficial as animal feed or a substitute for firewood. increasing the utilization of corncob waste and its financial cost can be gained through bioconversion method, a method to turn waste into fuel such as bioethanol [3][4]. during 1969 to 2015, the year 2015 produced the highest maize production in indonesia of 20,667 million tons [5]. bioethanol is a biofuel that is renewable as long as there are sunlight, water, oxygen, and agriculture practices [6][7]. bioethanol is superior to other fuel oils in the market because it has a higher oxygen content to burn perfectly, higher octane number, and is more environmentally friendly because it contains lower co content [8][9]. based on the above data, bioethanol is an alternative energy that becomes the most recommended renewable energy and could solve the existing pollution problems [10]. the most common ingredients in bioethanol are molasses [11] and crude fiber materials that high in carbohydrate, lipid, and nutrient contents [12][13][14]. ethanol can be used in its pure form, mixed with gasoline, or interacted with hydrogen to create fuel cell energy source for internal combustion [15][16]. potential plants for bioethanol production are those with high carbohydrate content, such as sugarcane, sugarcane juice, sugar palm, sorghum, cassava, cashew (cashew waste), arrowroot, banana stem, sweet potato, corn, * correspon ding author. tel: +62-8123118193 e-mail address: widiyanti.ft@um.ac.id https://dx.doi.org/10.14203/j.mev.2019.v10.24-28 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.24-28 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.24-28&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ widiyanti et al. / journal of mechatronics, electrical power, and vehicular technology 10 (201 9) 24–28 25 corncob, straw, and bagasse (sugarcane bagasse) [17]. ethanol is a liquid with a distinct odor [18], flammable, colorless [19], water-soluble [20], and volatile [21]. until 2015, the global primary energy consumption consists of 7 % water power, 4 % nuclear, 33 % oil, 30 % coal and 24 % natural gas [22][23]. the world energy consumption is projected to rise by 47.41 % from 2010 to 2040 [23] with the non-oecd countries, for example, indonesia, dominate the consumption [22]. the newest type of fuel in indonesia is ron 90 or commonly called pertalite with 90 octane number. pertalite is created by adding an additive element in its production in the refinery. pertalite consists of naphtha—a refinery material with a boiling point between gasoline and kerosene and ron of 65 to 70, a high octane mogas component (homc) which has a ron of 92 to 95, and a fuel additive called eco save [24]. the previous research discussed the measurement of co, co2, hc, and n2 exhaust emissions on lightweight transportations [25][26][27][28]. park [29] also examined the premixing effect of hc, co, and nox exhaust emissions from a mixture of bioethanol and gasoline. the emission test and machine performance fueled with a mix of biodiesel and ethanol had an inversely proportionate result between co and co2 [30], meanwhile, adding more than 20 % ethanol in biodiesel did not affect the machine performance [31]. this research aimed to determine the exhaust emission levels of co and co2 generated from a gasoline motor fueled with a mixture of bioethanol containing 96 % corncob and ron 90 fuel and to identify which variation of fuel mixture has the lowest exhaust emission level of co and co2. the update in this study was the optimal composition of the corncob bioethanol fuel and ron 90 mixture with minimal corrosive levels. ii. materials and methods this study used an experimental research method which is aiming to examine the effect of a given treatment under controllable conditions. the analysis in this study used the descriptive statistic and one way anova statistical test [32]. the descriptive analysis was useful to analyze the overall observation of co and co2 exhaust emission level while the one way anova statistical test was used to test the hypothesis. several instruments in this research were helpful to facilitate data collection from sample tests so that the generated data were more accurate, comprehensive, complete, and systematic and established easy-processing research. the tests used a gasoline generator fueled with a mixture of corncob-based bioethanol and ron 90 fuel as the device. the engine performance analyzation aimed to obtain the co and co2 emissions at a constant engine speed of 3000 rpm. this research used a digital mass scale, measuring cups, erlenmeyer flasks, volumetric flasks, volumetric pipettes, stopwatch, ammeter, light bulbs, tachometer, and digital stargas 898 as the measuring instruments. the materials in this research were corncob-based bioethanol with 96 % purity level and ron 90 fuel. this research conducted the tests according to the five fuel mixtures with different concentrations of corncob-based bioethanol and ron 90 fuel in a gasoline generator. the five variations of the fuel mixture were 100 % ron 90, 75 % ron 90 + e25, 50 % ron 90 + e50, 25 % ron 90 + e75, and e100. iii. results and discussions this experimental research answered the question on the best mixture ratio of fuels to create the lowest co and co2 emission. the tests mixed both fuels in five ratio variations to obtain it. the results at table 1 shows that from five mixture variations of ron 90 and corncob-based bioethanol, there were uniformed results; in which more load generated more co and co2 exhaust emissions. the results were different from the experiment of ehsaan [33], that declared that co2 exhaust emission was insignificantly increased, unlike the co exhaust emission. the data shown in figure 1 addresses that the use of fuel mixture containing ron 90 fuel and corncobbased bioethanol produced a lower co exhaust emission compared to the 100 % ron 90 fuel. this result occurred because ethanol has more oxygen content than ron 90 fuel, so the fuel combustion process was more likely to be perfect and generated fewer exhaust emissions [34]. ethanol has an oxygenate compound with one oh in its molecular structure [35]. the presence of inherent oxygen in inert ethanol helps the combustion process [36] in the cylinder because it improved the atomization of air and fuel mixture. the use of 100 % ron 90 fuel produced the highest co emissions of 3.373 vol% under a load of 1200 w and the 25 % ron 90 + e75 fuel generated the lowest co emission level of 0.01 vol% table 1. comparison results of co and co2 exhaust emission from a mixture of ron 90 and bioethanol no. load 100 % ron 90 75 % ron 9 0+e25 50 % ron 9 0+e50 25 % ron 9 0+e75 e100 co (vol%) co2 (vol%) co (vol%) co2 (vol%) co (vol%) co2 (vol%) co (vol%) co2 (vol%) co (vol%) co2 (vol%) 1. 200 w 1.79 6.38 0.94 5.91 0.14 6.53 0.01 5.94 0.13 4.94 2. 400 w 2.37 7.13 1.10 6.14 0.21 6.92 0.10 6.46 0.15 5.79 3. 600 w 2.43 7.60 1.28 7.27 0.25 7.10 0.11 6.75 0.16 6.52 4. 800 w 2.82 7.70 1.58 8.08 0.26 7.25 0.14 7.94 0.18 7.04 5. 1000 w 3.12 7.95 1.67 8.52 0.32 8.15 0.34 8.28 0.21 7.43 6. 1200 w 3.37 8.31 1.85 9.00 0.45 8.34 0.48 8.71 0.23 7.88 widiyanti et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 24–28 26 under a load of 200 w. using the 100 % ron 90 fuel of 2.649 vol% generated the highest average of co emissions and the e100 fuel produced the lowest one of 0.177 vol%. similarly, the co2 emission comparison result shown in figure 2 also showed that the addition of corncob-based bioethanol to ron 90 fuel had produced lower co2 emissions than the use of 100 % ron 90 fuel. overall, the co emission levels were lower than the co2 emissions. the engine with 75 % ron 90 + e25 fuel mixture under a load of 1200 w produced the highest co2 emission level of 9 vol% and the engine using the e100 fuel under a weight of 200 w generated the lowest one of 4.9 vol%. on average, the engine with the 100 % ron 90 fuel made the highest co2 emission of 7.51 vol%, and that fueled with the e100 fuel produced the lowest average of 6.6 vol%. iv. conclusion this research investigated the exhaust emission in gasoline motor fueled with a mixture of ron 90 gasoline fuel and corncob-based bioethanol. the results indicated that the co2 emission level tended to increase as with the increasing loading. overall, co emissions were lower than co2 emissions. the more the ethanol content in the fuel mixture, the lower the co emissions. on the other hand, the co2 exhaust emission had significantly different results. generally, the test results of co2 exhaust emission were similar to the co exhaust emission; in which they increased with the increasing load and decreased along with the additional ethanol content in the mixture. based on those results, the co exhaust emissions were significantly different, while co2 emissions were insignificantly different. the recommended fuel to be figure 1. comparison results of co exhaust emission (in vol%) figure 2. comparison results of co2 exhaust emission (in vol%) 0 0.5 1 1.5 2 2.5 3 3.5 200w 400w 600w 800w 1000w 1200w 100% ron 90 75% ron 90+e25 50% ron 90+e50 25% ron 90+e75 e100 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 200w 400w 600w 800w 1000w 1200w 100% ron 90 75% ron 90+e25 50% ron 90+e50 25% ron 90+e75 e100 widiyanti et al. / journal of mechatronics, electrical power, and vehicular technology 10 (201 9) 24–28 27 used was e100 because it had the lowest co and co2 exhaust emissions compared to other mixtures. however, due to the corrosive properties of ethanol, there needed modification in the fuel tank and its channel. furthermore, it was possible to mix the bioethanol with fuel mixtures from the market to decrease the corrosive that might occur with the recommended combination was 25 % ron 90 + e75. based on the results, the best fuel mixture was 25 % ron 90 + e75. this composition had the lowest co and co2 exhaust emissions and lowest corrosive property compared to the pure e100 composition. declarations author contribution widiyanti and c.a. wicaksana contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] i. v. muralikrishna and v. manickam, “solid waste management,” in environmental management, elsevier, 2017, pp. 431–462. [2] s. kaza, l. yao, p. bhada-tata, and f. van woerden , what a waste 2.0: a global snapshot of solid waste management to 2050. the world bank, 2018. [3] y. putrasari, a . praptijanto, w. b. santoso, an d o. lim, “resources, policy, and research activities of biofuel in indonesia: a review,” energy reports, vol. 2, pp. 237–245, nov. 2016. [4] d. m. rahmah, f. rizal, and a . bun yamin, “model dinamis produksi jagun g di indonesia,” j. teknotan, vol. 11, no. 1, jul. 2017. [5] a. bin arif, w. diyono, m. hayuningtyas, e. syaefullah, a. budiyanto, and n. richana, “penggandaan skala produksi bioetanol dari tongkol jagun g” inform. pertan ., vol. 26, no. 2, p. 57, dec. 2017. [6] h. zabed, j. n. sahu, a . suely, a . n. boyce, an d g. faruq, “bioethanol production from renewable sources: current perspectives and technological progress,” renew. sustain. energy rev., vol. 71, pp. 475–501, may 2017. [7] m. guo, w. song, and j. buhain, “bioenergy an d biofuels: history, status, and perspective,” renew. sustain. energy rev., vol. 42, pp. 712–725, feb. 2015. [8] g. najafi, b. ghobadian, t. tavakoli, d. r. buttsworth, t. f. yusaf, and m. faizollahnejad, “performan ce and exhaust emissions of a gasoline en gine with ethanol-blended gasoline fuels using artificial neural network,” a ppl. energy, vol. 86, no. 5, pp. 630– 639, may 2009. [9] h. kim and b. choi, “the effect of biodiesel an d bioethanol blended diesel fuel on nanoparticles and exhaust emissions from crdi diesel engine,” renew. energy, vol. 35, no. 1, pp. 157–163, jan. 2010. [10] f. wang et al., “an environmentally friendly and productive process for bioethanol production from potato waste,” biotechnol. biofuels, vol. 9, no. 1, p. 50, dec. 2016. [11] l. canilha et al., “bioconversion of sugarcane biomass into ethanol: an overview about composition, pretreatment methods, detoxification of hydrolysates, en zymatic saccharification, and ethanol fermentation,” j. biomed. biotechnol., vol. 2012, pp. 1–15, 2012. [12] j. singh and s. gu, “commercialization potential of microalgae for biofuels production,” renew. sustain . energy rev., vol. 14, no. 9, pp. 2596–2610, dec. 2010. [13] m. k. lam and k. t. lee, “microalgae biofuels: a critical review of issues, problems an d the way forward,” biotechnol. adv., vol. 30, no. 3, pp. 673–690, may 2012. [14] n. brosse, a. dufour, x. meng, q. sun, an d a. ragauskas, “miscanthus : a fast-growing crop for biofuels and chemicals production ,” biofuels, bioprod. biorefining, vol. 6, no. 5, pp. 580–598, sep. 2012. [15] m. z. jacobson, “review of solutions to global warming, air pollution, and energy security,” energy environ. sci., vol. 2, no. 2, pp. 148–173, 2009. [16] h. l. maclean and l. b. lave, “evaluating automobile fuel/propulsion system technologies,” prog. energy combust. sci., vol. 29, no. 1, pp. 1–69, 2003. [17] a. d. kurniawan and s. s. sanuri, “analisa pen ggunaan bahan bakar bioethanol dari batang padi sebagai campuran pada bensin ,” j. tek. its, vol. 1, no. 2014, 3ad. [18] i. t. horváth, h. meh di, v. fábos, l. boda, and l. t. mika, “γvalerolactone—a sustainable liquid for energy and carbon-based chemicals,” green chem., vol. 10, no. 2, pp. 238–242, 2008. [19] h. behniafar and n. sefid-girandehi, “optical and thermal behavior of novel fluorinated polyimides capable of preparing colorless, transparent and flexible films,” j. fluor. chem., vol. 132, no. 11, pp. 878–884, nov. 2011. [20] y. j. chen , x. y. xue, y. g. wang, and t. h. wang, “synthesis and ethanol sensing characteristics of single-crystalline sno2 nanorods,” appl. ph ys. lett., vol. 87, no. 23, p. 233503, dec. 2005. [21] a. mirzaei, s. g. leonardi, and g. neri, “detection of hazardous volatile organic compounds (vocs) by metal oxide nanostructures-based gas sen sors: a review,” ceram. int., vol. 42, no. 14, pp. 15119–15141, nov. 2016. [22] s. bilgen, “structure an d environmental impact of global energy consumption ,” renew. sustain. energy rev., vol. 38, pp. 890– 902, oct. 2014. [23] bp, “bp statistical review of world energy 2019,” 2019. [24] i. w. b. a . i wayan budi ariawan , i gusti bagus wijaya kusuma, “pengaruh penggunaan bahan bakar pertalite terhadap unjuk kerja daya, torsi dan konsumsi bahan bakar pada sepeda motor bertransmisi otomatis,” j. mettek, 2016. [25] m. v. prati, m. a . costagliola, c. tommasino, l. della ragione, and g. meccariello, “road grade influence on the exhaust emissions of a scooter fuelled with bioethanol/gasoline blen ds,” transp. res. procedia, vol. 3, pp. 790–799, 2014. [26] s. a. shahir, h. h. masjuki, m. a. kalam, a. imran, an d a. m. ashraful, “performance and emission assessment of diesel– biodiesel–ethanol/bioethanol blend as a fuel in diesel en gines: a review,” renew. sustain . energy rev., vol. 48, pp. 62–78, aug. 2015. [27] y. h. tan, m. o. abdullah, c. nolasco-hipolito, n. s. a. zauzi, and g. w. abdullah, “engine performance and emissions characteristics of a diesel engine fueled with diesel-biodieselbioethanol emulsions,” energy con vers. manag., vol. 132, pp. 54–64, jan . 2017. [28] a. h. sebayan g et al., “prediction of en gine performan ce and emission s with manihot glaziovii bioethanol − gasoline blended using extreme learning machine,” fuel, vol. 210, pp. 914–921, dec. 2017. [29] s. h. park, s. h. yoon, an d c. s. lee, “bioethanol and gasoline premixing effect on combustion and emission characteristics in biodiesel dual-fuel combustion engine,” a ppl. energy, vol. 135, pp. 286–298, dec. 2014. [30] a. veeresh, k. ganesh, m. vijay, and p. ravi, “investigation on the performance and emission characteristics of biodiesel animal oil ethanol blends in a single cylinder diesel engine,” in international conference on advances in a pplied science and environmental technology aset 2015, 2015, pp. 115–119. [31] s.-y. no, “a review on spray characteristics of bioethanol and its blended fuels in ci engines,” j. ilass-korea, vol. 19, no. 4, pp. 155–166, dec. 2014. [32] s. s. shapiro and m. b. wilk, “an analysis of variance test for normality (complete samples),” biometrika, vol. 52, no. 3/4, p. https://doi.org/10.1016/b978-0-12-811989-1.00016-6 https://doi.org/10.1016/b978-0-12-811989-1.00016-6 https://doi.org/10.1016/b978-0-12-811989-1.00016-6 https://doi.org/10.1596/978-1-4648-1329-0 https://doi.org/10.1596/978-1-4648-1329-0 https://doi.org/10.1596/978-1-4648-1329-0 https://doi.org/10.1016/j.egyr.2016.08.005 https://doi.org/10.1016/j.egyr.2016.08.005 https://doi.org/10.1016/j.egyr.2016.08.005 https://doi.org/10.1016/j.egyr.2016.08.005 https://doi.org/10.24198/jt.vol11n1.4 https://doi.org/10.24198/jt.vol11n1.4 https://doi.org/10.24198/jt.vol11n1.4 https://doi.org/10.21082/ip.v26n2.2017.p57-66 https://doi.org/10.21082/ip.v26n2.2017.p57-66 https://doi.org/10.21082/ip.v26n2.2017.p57-66 https://doi.org/10.21082/ip.v26n2.2017.p57-66 https://doi.org/10.1016/j.rser.2016.12.076 https://doi.org/10.1016/j.rser.2016.12.076 https://doi.org/10.1016/j.rser.2016.12.076 https://doi.org/10.1016/j.rser.2016.12.076 https://doi.org/10.1016/j.rser.2014.10.013 https://doi.org/10.1016/j.rser.2014.10.013 https://doi.org/10.1016/j.rser.2014.10.013 https://doi.org/10.1016/j.apenergy.2008.09.017 https://doi.org/10.1016/j.apenergy.2008.09.017 https://doi.org/10.1016/j.apenergy.2008.09.017 https://doi.org/10.1016/j.apenergy.2008.09.017 https://doi.org/10.1016/j.apenergy.2008.09.017 https://doi.org/10.1016/j.renene.2009.04.008 https://doi.org/10.1016/j.renene.2009.04.008 https://doi.org/10.1016/j.renene.2009.04.008 https://doi.org/10.1016/j.renene.2009.04.008 https://doi.org/10.1186/s13068-016-0464-7 https://doi.org/10.1186/s13068-016-0464-7 https://doi.org/10.1186/s13068-016-0464-7 https://doi.org/10.1155/2012/989572 https://doi.org/10.1155/2012/989572 https://doi.org/10.1155/2012/989572 https://doi.org/10.1155/2012/989572 https://doi.org/10.1155/2012/989572 https://doi.org/10.1016/j.rser.2010.06.014 https://doi.org/10.1016/j.rser.2010.06.014 https://doi.org/10.1016/j.rser.2010.06.014 https://doi.org/10.1016/j.biotechadv.2011.11.008 https://doi.org/10.1016/j.biotechadv.2011.11.008 https://doi.org/10.1016/j.biotechadv.2011.11.008 https://doi.org/10.1002/bbb.1353 https://doi.org/10.1002/bbb.1353 https://doi.org/10.1002/bbb.1353 https://doi.org/10.1002/bbb.1353 https://doi.org/10.1039/b809990c https://doi.org/10.1039/b809990c https://doi.org/10.1039/b809990c https://doi.org/10.1016/s0360-1285(02)00032-1 https://doi.org/10.1016/s0360-1285(02)00032-1 https://doi.org/10.1016/s0360-1285(02)00032-1 http://ejurnal.its.ac.id/index.php/teknik/article/view/5767/1646 http://ejurnal.its.ac.id/index.php/teknik/article/view/5767/1646 http://ejurnal.its.ac.id/index.php/teknik/article/view/5767/1646 https://doi.org/10.1039/b712863k https://doi.org/10.1039/b712863k https://doi.org/10.1039/b712863k https://doi.org/10.1016/j.jfluchem.2011.06.017 https://doi.org/10.1016/j.jfluchem.2011.06.017 https://doi.org/10.1016/j.jfluchem.2011.06.017 https://doi.org/10.1016/j.jfluchem.2011.06.017 https://doi.org/10.1063/1.2140091 https://doi.org/10.1063/1.2140091 https://doi.org/10.1063/1.2140091 https://doi.org/10.1016/j.ceramint.2016.06.145 https://doi.org/10.1016/j.ceramint.2016.06.145 https://doi.org/10.1016/j.ceramint.2016.06.145 https://doi.org/10.1016/j.ceramint.2016.06.145 https://doi.org/10.1016/j.rser.2014.07.004 https://doi.org/10.1016/j.rser.2014.07.004 https://doi.org/10.1016/j.rser.2014.07.004 https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-primary-energy.pdf https://ojs.unud.ac.id/index.php/mettek/article/view/23007/15147 https://ojs.unud.ac.id/index.php/mettek/article/view/23007/15147 https://ojs.unud.ac.id/index.php/mettek/article/view/23007/15147 https://ojs.unud.ac.id/index.php/mettek/article/view/23007/15147 https://doi.org/10.1016/j.trpro.2014.10.059 https://doi.org/10.1016/j.trpro.2014.10.059 https://doi.org/10.1016/j.trpro.2014.10.059 https://doi.org/10.1016/j.trpro.2014.10.059 https://doi.org/10.1016/j.rser.2015.03.049 https://doi.org/10.1016/j.rser.2015.03.049 https://doi.org/10.1016/j.rser.2015.03.049 https://doi.org/10.1016/j.rser.2015.03.049 https://doi.org/10.1016/j.rser.2015.03.049 https://doi.org/10.1016/j.enconman.2016.11.013 https://doi.org/10.1016/j.enconman.2016.11.013 https://doi.org/10.1016/j.enconman.2016.11.013 https://doi.org/10.1016/j.enconman.2016.11.013 https://doi.org/10.1016/j.enconman.2016.11.013 https://doi.org/10.1016/j.fuel.2017.08.102 https://doi.org/10.1016/j.fuel.2017.08.102 https://doi.org/10.1016/j.fuel.2017.08.102 https://doi.org/10.1016/j.fuel.2017.08.102 https://doi.org/10.1016/j.apenergy.2014.08.056 https://doi.org/10.1016/j.apenergy.2014.08.056 https://doi.org/10.1016/j.apenergy.2014.08.056 https://doi.org/10.1016/j.apenergy.2014.08.056 https://doi.org/10.15224/978-1-63248-040-8-94 https://doi.org/10.15224/978-1-63248-040-8-94 https://doi.org/10.15224/978-1-63248-040-8-94 https://doi.org/10.15224/978-1-63248-040-8-94 https://doi.org/10.15224/978-1-63248-040-8-94 https://doi.org/10.15435/jilasskr.2014.19.4.155 https://doi.org/10.15435/jilasskr.2014.19.4.155 https://doi.org/10.15435/jilasskr.2014.19.4.155 https://doi.org/10.2307/2333709 https://doi.org/10.2307/2333709 widiyanti et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 24–28 28 591, dec. 1965. [33] m. ehsan, m. s. a. bhuiyan, and n. naznin, “multi-fuel performance of a petrol en gine for small scale power generation,” 2003. [34] a. n. özsezen, “evaluating environmental effects of bioethanol-gasoline blends in use a si engine,” uluslararası yakıtlar yanma ve yangın derg., no. 4, pp. 36–41, dec. 2016. [35] p. dirrenberger et al., “laminar burning velocity of gasolines with addition of ethanol,” fuel, vol. 115, pp. 162–169, jan . 2014. [36] a. fossdal et al., “study of inexpen sive ox ygen carriers for chemical looping combustion,” int. j. greenh. gas control, vol. 5, no. 3, pp. 483–488, may 2011. https://doi.org/10.2307/2333709 https://doi.org/10.4271/2003-32-0063 https://doi.org/10.4271/2003-32-0063 https://doi.org/10.4271/2003-32-0063 https://dergipark.org.tr/en/download/article-file/303216 https://dergipark.org.tr/en/download/article-file/303216 https://dergipark.org.tr/en/download/article-file/303216 https://doi.org/10.1016/j.fuel.2013.07.015 https://doi.org/10.1016/j.fuel.2013.07.015 https://doi.org/10.1016/j.ijggc.2010.08.001 https://doi.org/10.1016/j.ijggc.2010.08.001 https://doi.org/10.1016/j.ijggc.2010.08.001 mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.86-94 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. pole placement and lqr implementation on longitudinal altitude holding control of wing in surface effect vehicle muhammad nanda setiawan a,*, evan rizky suryana b, leo parytta c, william andaro.c a department of renewable energy engineering, universitas prasetiya mulya bsd city kavling edutown i.1, tangerang, indonesia b department of engineering physics, multimedia nusantara university jl. scientia boulevard gading serpong, tangerang, indonesia c department of physics energy engineering, surya university f8 & f9 grand serpong mall jalan mh. thamrin panunggangan utara, tangerang, indonesia received 3 august 2020; accepted 5 november 2020; published online 22 december 2020 abstract the longitudinal altitude holding control system (lahcs) of wing in surface effect (wise) vehicle has been developed using simulink/matlab. the lahcs is designed to maintain the altitude of the vehicle stands at 1 m above the surface, with a maximum allowable deviation of 0.5 m. the purpose is to gain an additional lift generated by the surface effect to increase the aerodynamic performance. this control system is investigated using two approaches, i.e., the pole placement and the linear quadratic regulator (lqr) methods. originally, the system shows an unstable response on the phugoid mode, indicated by the positive value of its eigen. after the pole placement method is applied, the system is stable and capable of maintaining the reference command altitude. this method produces 0.27 of the maximum altitude deviation when the disturbance, represented by the doublet input elevator ±5° is applied. moreover, the time needed for the system to reach the steady-state response of altitude is around 2.2 seconds. in comparison, the lqr method is also applied to the system with the same scenario. although the settling time response is quite similar to the previous result, its maximum altitude deviation is significantly reduced by around 80 %. in conclusion, both of the methods used to design the lahcs are capable of maintaining the altitude of the wise vehicle always below its maximum deviation tolerance. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: wing in surface effect vehicle; altitude holding control system; pole placement method; linear quadratic regulator (lqr); phugoid mode; doublet input elevator. i. introduction indonesia is an archipelago country, where most of its territory is dominated by the ocean. indonesian fishermen utilize the ocean to make a living. unfortunately, the high amount of illegal fishing carried out by other countries makes local anglers suffer losses. in order to prevent illegal fishing, the indonesian government conducts monitoring activity around the outermost areas. the surveillance is generally carried out by indonesian soldiers using a speedboat. however, due to the high density of water, speedboats suffer from high drag, thus limiting their speed and manoeuvrability. high drag also tends to cause higher fuel consumption, especially against the sea waves. so, it is needed to find alternative vehicles with less fuel consumption to increase the maximum range of the observed area. according to li and chen [1], the surface effect of the wise vehicle could increase the lift to drag ratio by 40 % 70 %. consequently, it does not only reduce the fuel consumption rate significantly but also increases the coverage area. another study by amir et al. [2] concludes that the wise vehicle’s capabilities are superior over marine vessels. the wise vehicle speed is relatively faster and the co2 emission is 20 % lower due to its fuel efficiency. due to its advantages, the wing in surface effect vehicle has a potential to be applied to marine surveillance missions in indonesia. this vehicle utilizes the benefit from the ground effect, which increases the aerodynamic performance (lift to drag ratio). the higher lift to drag ratio represents the higher aerodynamic efficiency, which reduces fuel consumption. in order to gain benefit from the * corresponding author. phone:+6221-30450500. e-mail address: nanda.setiawan@prasetiyamulya.ac.id https://dx.doi.org/10.14203/j.mev.2020.v11.86-94 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.86-94 https://dx.doi.org/10.14203/j.mev.2020.v11.86-94 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.86-94&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:nanda.setiawan@prasetiyamulya.ac.id m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 87 ground effect, the wise vehicle needs to maintain its altitude always near the surface [3]. however, aerodynamic modelling and stability analysis on the wise vehicle is rather more complex than the regular aircraft due to the ground effect. also, the wise vehicles control system plays an important role in flight safety because of the close proximity of the craft to the sea surface. studies on wise vehicle aerodynamic modelling and stability analysis has been done [4][5][6], but studies on the control system are still limited due to its complexity [7][8]. this paper discusses the development of the lahcs of the wise vehicle using pole placement and lqr methods. the control system must be able to maintain the vehicle’s altitude around 1 m above the surface, with a maximum deviation of 0.5 m. this is the main requirement for designing the lahcs. it will guarantee not only the benefits from an additional lift but also to prevent the vehicle from crashing onto the surface. in the previous research, the development of an automatic flight control system of wing in surface effect craft (wise-craft) has been conducted by hari muhammad et al. [9]. the automatic flight control is designed using the gain scheduling method, where the gains are obtained from the root locus diagram. the control system on that research can stabilize the wise vehicle both for phugoid and short period modes. they simulate the control performances with three different operational altitudes, defined as 1 m, 2 m, and 3 m. however, the maximum altitude deviation is still high, standing around 0.72 m. it will have a safety issue for lower operational altitude, i.e., 1 m above the surface. in order to improve the robustness stability of the system, the pole placement and lqr methods are applied to our lahcs design. the gains parameters of the pole placement method are calculated based on the ackermans formula, while the lqr is implemented by setting the weighting matrix q and r based on the parameters that want to improve. the doublet input elevator is used to simulate the robustness of the system in order to deal with a disturbance. it is defined as a double step input with the amplitude ±5° with 4 seconds period. the flight dynamic equation is constructed with a linear approach by using a longitudinal dynamic equation, where the lateral effect is decoupled based on the small disturbance theory [10][11][12]. to deal with complexity, the thrust parameter is neglected from the equation, hence the speed of the aircraft is assumed to be constant and the input parameter is limited only regarding the elevator deflection. besides, the wise aerodynamic coefficients are calculated using datcom+ or xflr5 program by inputting the vehicle’s geometry [13][14]. ii. materials and methods a. aerodynamic coefficient the longitudinal dynamic equation is obtained from the derivation of the wise aerodynamic formula, affected by its geometry design. the first model of wise vehicle is developed at surya university. this vehicle is designed to accommodate up to nine passengers, including the pilot. the expected cruise and top speed of the vehicle are 100 km/h and 150 km/h, respectively. figure 1 describes the 3d model of the wise vehicle. the geometry of the aircraft in figure 1 can be used as an input for the xflr5 program to extract its aerodynamic coefficients. moreover, the flight condition variations, i.e., angle of attack, velocity, and altitude also take into account in order to simulate the real condition figure 1. 3d model of wise vehicle m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 88 of the vehicle while operating. the parameters of the wise vehicle used as the baseline system for xlfr5 input are listed in table 1. the aerodynamic coefficients extracted from the xlfr5 software are listed in table 2, where 𝐶𝑋, 𝐶𝑍, and 𝐶𝑚 stand for the coefficient of axial force, normal force, and pitching moment, respectively. these results are generated based on the data in table 1. it can be seen that the altitude and the angle of attack are varied in order to capture all data possibilities regarding the operational condition of the wise vehicle. the forces coefficients in table 2 are distinguished regarding its derivative, i.e., axial velocity, angle of attack, pitch rate, pitch angle, and control surface deflection. in order to get their dimensionless quantities, the values in table 2 are then submitted to the equations in table 3, where 𝑉0, 𝑚, 𝑆, 𝑐̿, 𝐼𝑦𝑦 stand for operational velocity, mass of the vehicle, span of the wing, mean aerodynamic chord, and polar moment of inertia respectively these equations are used to arrange the longitudinal dynamic equation of the wise vehicle by assuming that there is no coupling from the lateral mode and the thrust parameter is neglected. it means that the vehicle’s speed is maintained to a steady level (constant) and the longitudinal control relies only upon the elevator [15]. these non-dimensional aerodynamic coefficients are then arranged into the state space equation, which later can be used as a basis of systems improvement with the pole placement and lqr methods. by observing the root locus behaviour of the original system, the feedback gains can be examined based on their transient performances, i.e., maximum overshoot, settling time, steady-state error, etc. b. longitudinal dynamic equation as discussed in the previous section, the dimensionless aerodynamic coefficients in table 3 are important in determining the flight behavior of the wise in the longitudinal direction. it describes the axial velocity, pitch rate, pitch angle, altitude, and the elevator deflection angle of the aircraft. it should be noted that these results are calculated based on the geometric input of the aircraft. as such, providing the detail of a 3d model of the wise vehicles is mandatory; otherwise, the parameters cannot be extracted accurately from the xflr5. however, to deal with complexity, the engine geometry is excluded from the calculation. for future improvement, the non-dimensional aerodynamic coefficients derivation from the entire aircraft can be calculated using a better table 1. parameter of the wise vehicle parameter value mass, m 1000 (kg) mean aerodynamic chord, c 3.28 (m) centre of gravity, xcg 28% mac angle of attack, αe -6° to 20° velocity, v0 100 to 150 (km/h) altitude, h 0.5 to 2 (m) wing area, sw 19.77 (m2) horizontal tail area, sh 4.47 (m2) horizontal tail area, sy 4.38 (m2) wing span, bw 7.38 (m) horizontal tail span, bh 4.45 (m) horizontal tail span, by 4.12 (m) vertical tail root chord, cr 2.974 (m) vertical tail tip chord, ct 1.276 (m) horizontal tail arm, lh 3.195 (m) vertical tail arm, lv 2.910 (m) roll moment inertia, ix 1.396 (kgm2) pitch moment inertia, iy 6.763 (kgm2) yaw moment inertia, iz 6.834 (kgm2) coupling inertia x-z, ixz -1.560 (kgm2) overall length 10 (m) overall height 1.78 (m) max. fuselage width 1.6 (m) wing dihedral angle, γw -9.1° wing incidence angle, ηw 7.81° ht incidence angle, ηh 0° vt sweep angle, λv 54.93° wing root airfoil naca 4415 wing tip airfoil naca 4415 ht airfoil naca 4415 vt airfoil naca 0012 table 2. aerodynamic coefficient calculation result coefficient derivative to u α q θ η cx∗ -0.10652 244.17 -0.000214 -8.41e-05 0.00143 cz∗ -0.013155 5.6533 13.162 5.19 -0.0043 cm∗ -0.030233 -2.9563 -36.376 -14.33214 -0.0293685 table 3. dimensionless aerodynamic coefficient calculation coefficient derivative to u α q θ η x∗ cxuρv0s 2m cxαρv0s 2m cxqρv0sc� 4m cxẇρsc� 4m cxδeρv0 2s 2m z∗ czuρv0s 2m czαρv0s 2m czqρv0sc� 4m czẇρsc� 4m czδeρv0 2s 2m m∗ cmuρv0sc� 2iyy cmαρv0sc� 2iyy cmqρv0sc� 2 4iyy cmẇρsc� 2 4iyy cmδeρv0 2sc� 2iyy m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 89 computational fluid dynamic approach. finally, after these parameters have been generated, the longitudinal dynamic equation of the aircraft can be arranged into a matrix, as shown in equation (1). this state matrix is constructed based on a single input of the elevator deflection angle. ⎣ ⎢ ⎢ ⎢ ⎡ u̇ α̇ q̇ θ ḣ ̇ ⎦ ⎥ ⎥ ⎥ ⎤ = ⎣ ⎢ ⎢ ⎢ ⎢ ⎡ xu xα xq xθ 0 zu zα zq zθ 0 mu mα mq mθ 0 0 0 1 0 0 0 -v0 0 v0 0⎦ ⎥ ⎥ ⎥ ⎥ ⎤ ⎣ ⎢ ⎢ ⎡ u α q θ h⎦ ⎥ ⎥ ⎤ + ⎣ ⎢ ⎢ ⎢ ⎢ ⎡ xη zη mη 0 0 ⎦ ⎥ ⎥ ⎥ ⎥ ⎤ η (1) the axial velocity is denoted as u, angle of attack as α, pitch rate as q, pitch angle as 𝜃, altitude as h, and elevator deflection angle as η. the dimensionless aerodynamic coefficient is then substituted for equation (1) to construct the complete wise longitudinal dynamic equation as written in equation (2). this equation is derived based on the assumptions made in the previous section. it dictates the de-coupled longitudinal dynamic equation of the aircraft with a single input from elevator deflection angle and multiple-output (simo) associated with the longitudinal response of the aircraft. this equation is then applied to closed-loop control based on the pole placement and lqr methods to improve system performance. ⎣ ⎢ ⎢ ⎢ ⎡ u̇ α̇ q̇ θ ḣ ̇ ⎦ ⎥ ⎥ ⎥ ⎤ = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ -0.0122149 -0.0106271 0 −9.81 0 -0.00518525 -5.28145 0.6270357 0 0 -4.97107e-12 0 0 0.21405 0 -28 -3.19801 1 0 0 0 0 0 28 0⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ ⎣ ⎢ ⎢ ⎡ u α q θ h⎦ ⎥ ⎥ ⎤ + ⎣ ⎢ ⎢ ⎢ ⎢ ⎡ 2.328277 -3.73085 -55.06689 0 0 ⎦ ⎥ ⎥ ⎥ ⎥ ⎤ η (2) by using equation (2), we can analyze the dynamic stability response of the wise vehicle which consists of two modes, i.e., short period and phugoid mode. the short period mode has a higher damping ratio compared to the phugoid mode. this makes the short period mode have a shorter time to recover against the disturbance. on the other hand, the phugoid mode is used when a smooth variable transition is needed. the stability of an aircraft can be analyzed from the root locus diagram, which dictates the dynamic stability of the mode’s characteristics. the root locus diagram of the original system can be seen in figure 2. based on the root locus diagram, the poles of the original system are located at 0, -5.3442, -3.135, 0.02, and -0.0325. we can conclude that the system has unstable issues where a pair of poles move to the right side of splane as the gain value increases. those poles represent the phugoid mode because of the low damping ratio, as stated before. another instability issue occurs at the pole located at 0.02, which moves further to the right side of the s-plane with the increase of the gain value. this pole needs to relocate in order to eliminate the divergence response. in order to choose a suitable location for the new poles that meet the requirements, it is decided to observe the transient characteristics response of the system produced. this looks inconvenient since there is no exact rule to follow. however, a root locus diagram of the original system can be helpful in order to give insight for determining the location of the new poles. based on this guidance, we can predict the transient behaviour of the system when several values of feedback gain are applied. the poles located on the right side of the s-plane shows an unstable behaviour since the positive eigenvalue will make the output to be divergent based on equation (3). x(t) = eλtx(0) (3) where 𝑥(𝑡) describes the state solution, 𝜆 is the eigenvalue of the system, 𝑡 is time, and 𝑥(0) is the initial condition of the system at 𝑡 = 0. when 𝜆 is positive, the state response will go to infinite as time increases. therefore, the poles on the right side of the s-plane need to be re altered to the left side using the pole placement or lqr methods. as mentioned before, in order to get the suitable gains feedback, it is needed to check the transient performances produced by varying several new poles location, i.e., maximum overshoot, settling time, etc. c. altitude hold control maintaining the altitude of the wise vehicle is important to keep the advantages of the ground effect as it produces a high lift to drag ratio. by adding an altitude holding control, the vehicle is expected capable of maintaining its altitude always around 1 meter above the surface. the altitude holding control is designed using the pole placement method, where the gain constant k is used as the feedback control. the purpose of applying the pole placement method is to accelerate the system performance by forcing the origin pole location of the longitudinal dynamic equation into the desired figure 2. root locus of the original system m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 90 location [16]. the wise longitudinal dynamic in equation (2) can be simplified as ẋ = ax + bu y = cx (4) where a is the longitudinal state matrix of the wise vehicle, b is the input matrix from the elevator, c is the output matrix, x is the state variable column matrix, u is the state variable input matrix, and y is the output column matrix. let us assume that the input signal is u = −kx (5) where 𝐾 is the state feedback gains matrix. using this assumption, we can modify equation (4) to be ẋ = (a − bk)x y = cx (6) the system’s response characteristics are determined by the eigenvalues of a − bk matrix, which indicates the new systems pole locations. the root locus diagram from the initial system is used as a guide to find the pole locations that meet the design criteria. it can be achieved by observing the transient response characteristics produced. in this paper, several variations of poles location are compared, and it is found that the pole locations that meet the design requirements are [-40 -1.9 -45 -40 -0.8]. the values of the gain matrix k are calculated using ackermann’s formula to give the feedback gain values stand at -14600, 27400, -2470, -2500, and -5140, respectively. the dynamic response of the system with new poles location then tested against a step function and doublet input elevator using simulink matlab. the block diagram of the lahcs and the longitudinal response of the system regarding the step input is shown in figure 3 and figure 4. we can see that the gains acquired from ackermann’s formula are implemented as feedback. the step function is implemented in order to extract the transient characteristics of the system, i.e., maximum overshoot, settling time, steady-state error, etc. [17] and [18]. initially, the wise vehicle is assumed to fly on a steady level until a unit step input is implemented. this input will raise the response of the system, called the step response function. equation (7) describes the unit step input figure 3. lahcs block diagram using the pole placement method figure 4. systems response to the unit step input m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 91 applied to the close loop simulation. s(t) = xsrf(t) = 1 k �1 − α β sinθ� (7) where: α = e−ξωnt, β = �1 − ξ2, and θ = ωdt + φ (8) tanφ = �1−ξ 2 ξ (9) where 𝑘 , 𝜉 , 𝜔𝑛 , 𝜔𝑑 , and 𝜑 stand for stiffness constant, damping ratio, natural frequency, damped frequency, and phase angle respectively. d. altitude hold using lqr in order to optimize the performance and the energy source of the system, the lqr method is applied by determining the weighting matrix of q and r. matrix q deals with the performance of the system, while matrix r is related to the cost factor. the q matrix was altered to consider the axial velocity q(1,1) and the altitude q(5,5) of the wise vehicle. these two parameters are adjusted in order to achieve the good performance of the system by observing the response on the simulation results. the purpose of these alterations of the q and r matrix is to minimize the cost function, represented as j = ∫ (xtqx + utru)dt ∞ 0 , which describes the area under the system response [12][19] and [20]. the detail of the q matrix alteration is presented as equation (10): q = ⎣ ⎢ ⎢ ⎢ ⎡ 100 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 5000⎦ ⎥ ⎥ ⎥ ⎤ (10) on the other hand, the r matrix is set at equation (11): r = [0.1] (11) using ricatti’s equation on equation (12), the lqr feedback gains can be determined as shown in equation (13) atp + pa − pbr−1btp + q = 0 (12) klqr = r−1btp (13) where b is the input matrix and p is the transformation matrix determined by solving the ricatti’s equation. calculating using matlab program we get the lqr feedback gains matrix is klqr = [0.31 837.8 −62.1 −1317.9 −223.6] iii. results and discussions a. control system response with pole placement method based on figure 4, it can be seen that the system is dynamically stable with good transient characteristics. the altitude deviation is not exceeding the requirement, standing around 0.03 m, while the time needed for the aircraft to achieve a steady level is around 3.85 seconds. table 4 summarizes the detailed response of the system regarding the unit step input. the system then tested against the doublet input elevator to observe the robustness of the system in order to deal with a disturbance. to create the doublet input elevator profile, the elevator angle is set at 5° for 2 seconds, and then it is changed to -5° for 2 seconds. finally, the elevator angle is set back to 0° and maintain at that level. this scenario represents a severe disturbance and it will be worth it to examine the robustness stability of the system. the responses of the wise vehicle using the pole placement method due to the doublet input elevator are shown in figure 5. figure 5. systems response of doublet input elevator m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 92 the results seem convincing to comply with the requirement. it can be seen that the system’s response due to the doublet input elevator has good transient characteristics, both for settling time and maximum deviation parameters. the angle of attack and pitch angle produced by the system’s responses are not significant enough to cause a high altitude difference. meanwhile, the maximum altitude deviation produced does not exceed 0.5 m, which stands at 0.272 m. it can be inferred that the pole placement method is successful to generate a robust response to maintain the altitude always near the surface level. detailed characteristics value from another response parameter can be seen in table 5. b. control system response with lqr method the comparison results between the pole placement and lqr methods regarding the unit step input and the double input elevator scenarios are shown in figure 6 and figure 7. it can be seen in figure 6. pp vs. lqr response of unit step input figure 7. pp vs. lqr response of doublet input elevator m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 93 figure 6 that the lqr method reduces the altitude deviation of the system significantly, around 80 % in comparison with the response of the pole placement method. however, the settling time is quite similar between both systems. figure 7 informs that the lqr method response is better than the pole placement method for all parameters. however, the lahcs using both pole placement and lqr method still meet the requirements and are capable of maintaining the altitude of the wise vehicle always near the surface. detailed characteristics value from another response parameter can be seen in table 6. iv. conclusion the lahcs designed using the pole placement method can maintain the reference command altitude in which the settling time, maximum deviation, and delay time stand at 6.246 seconds, 0.27 m, and 0.198 seconds respectively. in order to improve the performance of the system, the locations of the new poles are defined at λ1new = −40, λ2new = −1.9, λ3new = −45, λ4new = −40, and λ5new = −0.8 . the feedback gains obtained from ackermann’s formula based on the location of the new poles are k1 = −1.46x104, k2 = 2.74x104, k3 = −0.247x104, k4 = −2.5x104, and k5 = −0.514x104. on the other hand, the lqr method is capable to reduce the maximum altitude deviation by around 80 % on the unit step input response, although the settling time response for both methods is similar. however, for the doublet input elevator response representing a severe disturbance, the lqr method could produce the most robust response for all parameters. to sum up, the lahcs can maintain the altitude of the wise vehicle against the disturbance and hold the altitude always near the surface for both of the methods applied. acknowledgment the authors thank the department of physics energy engineering, surya university, for providing support and facilitation throughout the research. special thanks to mr. andaro, who shared the design of the wise vehicle. declaration author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] r. li and h. chen, “the feasibility of high speed ground effect vehicles,” 17th aiaa aviation technology, integration, and operations conference, 2017. [2] m. a. u. amir and et al., “wing in ground effect craft: a review of the state of current stability knowledge,” international conference on ocean mechanical and aerospace for scientists and engineer, 2016. [3] s. wiriadidjaja, a. zhahir, z. h. mohamad, s. razali, a. a. puaat and m. t. ahmad, “wing-in-ground-effect craft: a case study in aerodynamics,” international journal of engineering & technology, vol. 7(4), pp. 5-9, 2018. [4] h. wang, c. j. teo, b. c. khoo and c. j. goh, “computational aerodynamics and flight stability of wing-in-ground (wig) craft,” procedia engineering, vol. 67, pp. 15-24, 2013. [5] m. m. tofa, a. maimun, y. m. ahmed, s. jamei, a. priyanto and rahimuddin, “experimental investigation of a wing-inground effect craft,” the scientific world journal, vol. 2014, 2014. [6] n. kornev, “on unsteady effects in wig craft aerodynamics,” international journal of aerospace engineering, vol. 2019, 2019. [7] rahimuddin, a. maimun, m. m. tofa, s. jamei and tarmizi, “stability analysis of a wing in ground effect craft,” 14th international ship stability workshop, kuala lumpur, 2014. [8] a. nebylov and v. nebylov, “wing-in-ground effect vehicles flight automatic control systems development problems,” applied mechanics and materials, vol. 629, pp. 370-375, 2014. [9] h. muhammad, sembiring, javensius, jenie and d. said, “development of automatic flight control systems for wing in surface effect craft,” ifac proceedings, 2007. [10] w. yang, z. yang and m. collu, “longitudinal static stability requirements for wing in ground effect vehicle,” international journal of naval architecture and ocean engineering, vol. 7(2), pp. 259-269, 2015. [11] l. parytta and m. n. setiawan, “design of uav longitudinal regulator system stability due to turbulence on cloud seeding operation: a case study of wulung pa-07,” 7th international seminar on aerospace science and technology, jakarta, 2019. [12] e. rizky and m. n. setiawan, “design of uav lateral regulator system stability due to turbulence on cloud seeding operation: a case study of wulung pa-07,” 7th international seminar on aerospace science and technology, jakarta, 2019. table 4. response of system to the step input parameter max. deviation settling time axial velocity 0.0134 (m/s) 2.28 (s) angle of attack 0.022 (°) 0.5 (s) pitch rate 0.2921 (°/s) 0.27 (s) pitch angle 9.24e-6 (°) 0.41 (s) altitude 0.03255 m 3.85 (s) table 5. response of system to the doublet input elevator parameter max. deviation settling time axial velocity 0.1074 (m/s) 3.727 (s) angle of attack 0.2238 (°) 0.277 (s) pitch rate 3.11 (°/s) 0.219 (s) pitch angle 9.413e-1 (°) 0.423 (s) altitude 0.2723 m 2.246 (s) table 6. response of lqr system to the doublet input elevator parameter max. deviation settling time axial velocity 0.0558 (m/s) 0.2 (s) angle of attack 0.1036 (°) 0.05 (s) pitch rate 1.47 (°/s) 0.28 (s) pitch angle 1.95e-2 (°) 0.24 (s) altitude 0.0552 m 0.24 (s) https://doi.org/10.2514/6.2017-3423 https://doi.org/10.2514/6.2017-3423 https://doi.org/10.2514/6.2017-3423 https://www.researchgate.net/publication/311967696_wing_in_ground_effect_craft_a_review_of_the_state_of_current_stability_knowledge https://www.researchgate.net/publication/311967696_wing_in_ground_effect_craft_a_review_of_the_state_of_current_stability_knowledge https://www.researchgate.net/publication/311967696_wing_in_ground_effect_craft_a_review_of_the_state_of_current_stability_knowledge https://www.researchgate.net/publication/311967696_wing_in_ground_effect_craft_a_review_of_the_state_of_current_stability_knowledge https://doi.org/10.14419/ijet.v7i4.13.21319 https://doi.org/10.14419/ijet.v7i4.13.21319 https://doi.org/10.14419/ijet.v7i4.13.21319 https://doi.org/10.14419/ijet.v7i4.13.21319 https://doi.org/10.1016/j.proeng.2013.12.002 https://doi.org/10.1016/j.proeng.2013.12.002 https://doi.org/10.1016/j.proeng.2013.12.002 https://doi.org/10.1155/2014/489308 https://doi.org/10.1155/2014/489308 https://doi.org/10.1155/2014/489308 https://doi.org/10.1155/2014/489308 https://doi.org/10.1155/2019/8351293 https://doi.org/10.1155/2019/8351293 https://doi.org/10.1155/2019/8351293 https://doi.org/10.13140/rg.2.1.1455.8167 https://doi.org/10.13140/rg.2.1.1455.8167 https://doi.org/10.13140/rg.2.1.1455.8167 https://doi.org/10.13140/rg.2.1.1455.8167 https://doi.org/10.4028/www.scientific.net/amm.629.370 https://doi.org/10.4028/www.scientific.net/amm.629.370 https://doi.org/10.4028/www.scientific.net/amm.629.370 https://doi.org/10.3182/20070625-5-fr-2916.00020 https://doi.org/10.3182/20070625-5-fr-2916.00020 https://doi.org/10.3182/20070625-5-fr-2916.00020 https://doi.org/10.1515/ijnaoe-2015-0018 https://doi.org/10.1515/ijnaoe-2015-0018 https://doi.org/10.1515/ijnaoe-2015-0018 https://doi.org/10.1515/ijnaoe-2015-0018 https://doi.org/10.1063/5.0002801 https://doi.org/10.1063/5.0002801 https://doi.org/10.1063/5.0002801 https://doi.org/10.1063/5.0002801 https://doi.org/10.1063/5.0002801 https://doi.org/10.1063/5.0002368 https://doi.org/10.1063/5.0002368 https://doi.org/10.1063/5.0002368 https://doi.org/10.1063/5.0002368 https://doi.org/10.1063/5.0002368 m.n. setiawan et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 86-94 94 [13] r. finck and d. e. hoak, “the usaf stability and control datcom” engineering documents,” 1978. [14] q. qu, z. lu, p. liu and r. k. agarwal, “numerical study of aerodynamicsof a wing-in-ground-effect craft,” journal of aircraft, vol. 51(3), pp. 913-924, 2014. [15] m. v. cook, flight dynamics principles “a linear system approach to aircraft stability and control third edition,” burlington, ma: elsevier, ltd., 2012. [16] k. ogata, “modern control engineering,” new jersey: prentice hall, 2010. [17] j. e. cooper and j. r. wright, “introduction to aircraft aeroelasticity and loads-second edition,” chichester: john wiley and sons, 2015. [18] r. szabolcsi, “pole placement technique applied in unmanned aerial vehicles automatic flight control systems design,” land forces academy review, 23(1), pp. 88-98, 2018. [19] h. purnawan, mardlijah and e. b. purwanto, “design of linear quadratic regulator (lqr) control system for flight stability of lsu-05,” 1st international conference on applied & industrial mathematics and statistics, pahang, 2017. [20] a. jafar and et al, “a robust ∞ h control for unmanned aerial vehicle against atmospheric turbulence,” 2nd international conference on robotics and artificial intelligence, rawalpindi, 2016. https://www.worldcat.org/title/usaf-stability-and-control-datcom/oclc/25313219 https://www.worldcat.org/title/usaf-stability-and-control-datcom/oclc/25313219 https://doi.org/10.2514/1.c032531 https://doi.org/10.2514/1.c032531 https://doi.org/10.2514/1.c032531 https://www.amazon.com/flight-dynamics-principles-stability-engineering/dp/0080982425 https://www.amazon.com/flight-dynamics-principles-stability-engineering/dp/0080982425 https://www.amazon.com/flight-dynamics-principles-stability-engineering/dp/0080982425 https://www.amazon.com/modern-control-engineering-katsuhiko-ogata/dp/0136156738 https://www.amazon.com/modern-control-engineering-katsuhiko-ogata/dp/0136156738 https://www.wiley.com/en-id/introduction+to+aircraft+aeroelasticity+and+loads,+2nd+edition-p-9781118488010 https://www.wiley.com/en-id/introduction+to+aircraft+aeroelasticity+and+loads,+2nd+edition-p-9781118488010 https://www.wiley.com/en-id/introduction+to+aircraft+aeroelasticity+and+loads,+2nd+edition-p-9781118488010 https://doi.org/10.2478/raft-2018-0011 https://doi.org/10.2478/raft-2018-0011 https://doi.org/10.2478/raft-2018-0011 https://doi.org/10.2478/raft-2018-0011 https://doi.org/10.1088/1742-6596/890/1/012056 https://doi.org/10.1088/1742-6596/890/1/012056 https://doi.org/10.1088/1742-6596/890/1/012056 https://doi.org/10.1088/1742-6596/890/1/012056 https://doi.org/10.1109/icrai.2016.7791234 https://doi.org/10.1109/icrai.2016.7791234 https://doi.org/10.1109/icrai.2016.7791234 https://doi.org/10.1109/icrai.2016.7791234 i. introduction ii. materials and methods a. aerodynamic coefficient b. longitudinal dynamic equation c. altitude hold control d. altitude hold using lqr iii. results and discussions a. control system response with pole placement method b. control system response with lqr method iv. conclusion acknowledgment declaration author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.55-63 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback kamil faqih a, sujito b, *, siti sendari a, faiz syaikhoni aziz a a electrical engineering postgraduate, electrical engineering department, universitas negeri malang jl. semarang no. 5 sumbersari, lowokwaru, malang, east java, 65145, indonesia b intelligent power and advance energy system, electrical engineering department, universitas negeri malang jl. semarang no. 5 sumbersari, lowokwaru, malang, east java, 65145, indonesia received 25 july 2020; accepted 12 october 2020; published online 22 december 2020 abstract as a maritime country with a large area, besides the need to defend itself with the military, it also needs to protect itself with aerospace technology that can be controlled automatically. this research aims to develop an air defense system that can control guided missiles automatically with high accuracy. the right method can provide a high level of accuracy in controlling missiles to the targeted object. with the backpropagation neural network method for optimal control output feedback, it can process information data from the radar to control missile’s movement with a high degree of accuracy. the controller uses optimal control output feedback, which is equipped with a lock system and utilizes an accelerometer that can detect the slope of the missile and a gyroscope that can detect the slope between the target direction of the missile to follow the target, control the position, and direction of the missile. the target speed of movement can be easily identified and followed by the missile through the lock system. sampling data comes from signals generated by radars located in defense areas and from missiles. each part’s data processing speed is calculated using a fast algorithm that is reliable and has a level of accuracy and fast processing. data processing impacts on the accuracy of missile movements on any change in the position and motion of targets and target speed. improved maneuvering accuracy in the first training system can detect 1000 files with a load of 273, while in the last training, the system can detect 1000 files without a load period. so the missile can be guided to hit the target without obstacles when maneuvering. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: smart missile; backpropagation; neural network; optimal control; output feedback; lock system. i. introduction air attacks become a severe problem in the military world. air attacks can come in the form of cruise rockets, short-range rockets, warplanes, drones, and others. the observatory results by anthony d'amato in his research entitled retrospective measures of israeli air attack against the osiraq reactor [1] which explains that israeli airstrikes are considered understandable and legitimate defenses. so that in warfare, airstrikes can be categorized as a method of self-defense that can be allowed even if it has an enermous impact and a large number of victims. technological advances in the field of air defense must be developed along with the development of technology in air attack systems. the air defense, which has the most potential in counteracting airstrikes is missiles with a high level of maneuvering accuracy accompanied by an autopilot system that can guide missiles to hit targets in the air. eloy garcia et al. describe the effectiveness of air defense, with the theme of the cooperative missile guide to active defense of air vehicles [2]. about active countermeasures against missile attacks that lead to the aircraft as a target, with the aim of airstrikes can be anticipated to the maximum and can avoid casualties and material damage. one of the most needed air defense systems is a missile that can be launched and controlled automatically. missile targeting system by knowing the target location of the guidance system such as inertial navigation system (ins), and terrain contour matching (tercom) or global positioning system * corresponding author. tel: +62-851-32014085 e-mail address: sujito.ft@um.ac.id https://dx.doi.org/10.14203/j.mev.2020.v11.55-63 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.55-63 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.55-63&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 56 (gps). the use of the ins method mathematically developed by castro toscano m, j, et al., the theme is methodological use of inertial navigation systems for the task of strapdown navigation [3], which presents mathematical descriptions for inertial navigation systems and integration of device implementations. the virtual sensor can detect the weight of changes in the object (target), calculate variables such as speed, position, and attitude on the mobile body of the navigation system. so this system can guide the missile by knowing the missile position and target position, then calculate the distance and position of both. as for the tercom radar (on missile bodies) use a height gauge algorithm. research on the tercom radar was developed by zhang hua and hu xiulin with the theme of a height gauge algorithm applied to the tercom radar altimeter [4] which serves to measure the distance of the object. so that it can provide feedback on missile maneuver performance. one method of locking the missile system in tercom is using infrared. as developed by ab-rahman and mazen r., the locking system using the infrared method utilizes a detector that can detect high temperatures at the target to respond to missile defenses [5]. missile design with an infrared system was used in france during world war i [6]. missile's responsibility for targets has been developed by kerem g et al. with the theme response surface-based performance analysis of an air-defense missile system which aims to reduce the computational burden in each detection process when missiles are maneuvered [7]. the missile test launch system has been developed by baoquan li et al. about the measurement system and automatic testing of several surface-to-air autopilot missiles, which focus on the use of computer control and multimedia technology, to increase the speed and accuracy of measurement and testing to the maximum and reduce the training work time [8]. research that discusses defense missile architecture has been discussed by ender. t et al. with the theme of system-of-systems analysis the effectiveness of ballistic missile defense architecture through substitute modeling and simulation [9], using modeling and simulation that supports architecturelevel analysis on defense missiles including the sensitivity of operational-level metrics to the formation (overview) tracking integration and making the right decisions. the launching path for surface-to-air missiles has been developed by guomin and hui gu on simulating the availability of surface-to-air missile weapons systems that focus on estimating target points [10]. the smart system on missile control provides innovation in determining the direction of missile movement towards a target by utilizing an accelerometer sensor that functions to control the tilt of the rocket and the gyroscope sensor to detect the tilt of the target to the missile. the lock system is obtained from the data sent from ins and tercom. research on missiles utilizing ins radar has been developed by xinqi fu and meirong chen [11] about missile allocation based on sar bistatic-borne missiles, which utilize ins without relying on tercom, so missile maneuvers are less accurate in chasing target because missiles have difficulty detecting targets when missiles and targets are at a certain height. automatic control by utilizing sensors has been developed by faqih. k et al. with the theme of smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control [12], about control systems that utilize sensors for automatic control performance on power sources. significant progress has been achieved in the design of optimal control output feedback using the rl algorithm by modares et al [13]. optimal control is applied to develop the control system. meanwhile, frequency domain analysis in classical control theory is also used to verify system frequency performance, including crossover frequencies, phase margins, and profit margins, bringing restrictions on performance values. the controller obtained is the optimal output feedback controller for a simplified model with certain durability. optimal control theory and frequency domain analysis are combined to get fast tracking performance, small error conditions, and certain durability [14]. optimal control for missile guidance systems has been developed by jingliang sun et al with the theme "robust optimal control for missile-target guidance systems via adaptive dynamic programming", focusing on the effectiveness of a strong optimal control method for intercepting maneuvers with feedback using the adaptive dynamic programming (adp) technique [15]. to reduce the error rate in determining the meeting point between missiles and targets, the smart missile system utilizes the kalman filter in estimating state variables from a linear discrete dynamic system that minimizes the estimated error covariance [16]. another estimate is the extension of the kalman filter called the ensemble kalman filter (enkf). in the enkf method, the algorithm is executed by producing many specific ensembles to calculate the average and error covariance of state variables [17]. in using the enkf method, some schemes can be implemented in the enkf method, which is the square root scheme that can be implemented in enkf. this scheme can affect the estimation results, both in terms of accuracy and computational time [18], so it can be applied to estimate the missile position and simulated with matlab software. the autopilot design on air defense missiles has been developed by delin luo et al. [19]. target identification is carried out to test the performance of the missile autopilot, but it is still unable to detect the direction of the target which changed drastically, so the need for a more accurate maneuvering system on missiles equipped with intelligent algorithms. there is also a missile control study with a bank to turn (btt) system that can detect changes in the target direction, this study is represented by mehta s.s with the theme of adaptive vision-based missile guidance in the presence of avoiding target maneuvers [20]. with a focus on minimizing maneuvering errors with targets whose speed is unknown and can change. the btt system still k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 57 requires operators to control missile direction. so the guiding process is still too manual, so a microcontroller is needed to automatically adjust the missile body to the target. smart missile maneuver system is divided into several types of clusters according to the target direction, research on the missile direction cluster has been developed by jan farlik [21]. the theme is a simulation of surface-to-air missile units. the cluster system implemented by jan farlik is not yet equipped with an intelligent algorithm, so the target accuracy can be less stable in some circumstances. missile maneuver requires prediction of a meeting point between missile and target, research on missile maneuver prediction has been developed by lee s. et al. with the theme of missile guidance based on tracking the predicted target path [22] focusing only on determining missile maneuvers. so there is still no solution available if the missile is interrupted when maneuvering. intelligent algorithms can be a solution to minimize interference on missile maneuvers. backpropagation is an effective method for learning neural networks and has been widely used in various applications. the accuracy of the learning result, despite other facts, is highly affected by the volume of high-quality data used for learning [23]. neural network planting is one of the methods developed for air defense missile technology. as has been developed by deyun. z and feng. z with the theme of data fusion control and surface-to-air missile guidance under complex conditions based on neural-net technology [24] using a group method for data-processing to increase the effectiveness of landto-air missile weapons systems based on filter data tracked with a looping system. the amount of data trained is 500 so that it can be developed by adding the number of iterations at the training stage, as well as a more optimal looping system. research that has been developed by delin and mehta still utilizes btt manual control on missile maneuvers. so it can be more efficient if the missile maneuver control system is equipped with sensors and microcontrollers that are sufficient to guide the missile to the target automatically. while research has been developed by jan farlik and lee. s, the cluster system, and its prediction maneuver are still not equipped with an intelligent algorithm to handle files on missile maneuvers. embedding intelligent algorithms on missiles can be a solution to minimize vibration (fail) when missiles maneuver. this research aims to develop a system for air defense missiles that can maneuver chasing targets automatically with optimal feedback control that utilizes accelerometer sensor readings for automatic control. this system can minimize vibrations by utilizing the backpropagation neural network algorithm on the sensor detector which can control regular missile maneuvers based on the sensor value cluster. so that the missile maneuver can be better without the need for manual control. ii. materials and methods a. missile architecture the missile performance architecture has been prepared about device specifications not damage the missile launcher and body before and during the missile maneuver. the smart missile system has an operating flow as shown in the flowchart of figure 1. the operation flow starts when the radar gets the target info until the missile can reach the targeted object. data maneuvering is processed using matlab software, which is equipped with neural network tools to conduct training from data generated by sensors, with backpropagation neural network training methods. the training results become a reference for automatic control on the nozzle. with the embedded sensor in the automatic control on the smart algorithm for nozzle activation control, the smart missile maneuver process is more organized and accurate in chasing targets. b. backpropagation neural network missile algorithm neural network systems can help accurate maneuverability of automatic control of smart missiles. because the neural network can recognize an object non-linearly. neural network control learning provides feedback with many conditions, start feedback controll manuver initial target condition axis sensor detector train neural network launch missile auto pilot stand by initial missile condition no yes end hit targetmiss target figure 1. smart missile architecture flowchart k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 58 making it easier to map the input to a result, able to adapt to the recognition of an object, has tolerance for an error in the recognition of an object, can be implemented on hardware, and can be implemented in parallel [25]. artificial neural networks are usually composed of elements in layers that are connected and weighted. this network modifies these weights based on a series of inputs given from outside the system, to produce consistent and similar output to the given inputs. usually, each element will process based on mathematical operations that have been given to each element [26]. smart missile systems use the backpropagation neural network method. where backpropagation is a supervised learning algorithm and is usually used by perceptron with many layers to change the weights that are connected with neurons in the hidden layer [26]. the implantation of the backpropagation neural network algorithm in missiles has been developed by da huang et al. regarding activation controls on the missile tail to match the exact spectrum volume with strong resistance [27]. the backpropagation algorithm uses error output to change its value. to get this error, neurons are activated by using an activation function that can be differentiated. as shown in figure 2, smart missile maneuvering is weighted according to the target slope angle and the missile tilt. the weight that can be achieved is recorded at -10 m/s2 to 10 m/s2. the greater the weight of the target slope, the nozzle performance will be maximized with the shortest delay possible. the weight value is obtained from the comparison of the target lock system tilt periodically and the missile tilt periodically. the equation produced in the smart missile represents each neuron as shown in figure 3. each neuron is arranged by grouping several clusters based on the smart missile sensor’s weight to guide the missile to the target. the neuron continues to work until the detected target can be hit by a smart missile. the data axis is grouped into 72 clusters as neurons, so the missile can detect and chase targets coming from any direction. the neurons variables are paraded to focus on the movement of the missile tilt by minimizing the readout of the vibrations so that nozzle activation is more regular. in addition to neurons, control maneuvers as hidden layers are also grouped (cluster) according to target and missile conditions. clusters in hidden layers are arranged in nine clusters to control 24 nozzles as shown in figure 4. nine hidden layers arranged to condition the nozzle activation as follows; • low maneuverability; if one nozzle is activated • medium maneuver; when two (in a group) nozzles are activated • hard maneuvers; when three (in a group) nozzles are activated • low & low maneuverability; when two (in two groups) nozzles are activated • low & medium maneuvers; when three (in two groups) nozzles are activated • low & hard maneuvers; if four (in two groups) nozzles are activated • medium & medium maneuvers; if four (in two groups) nozzles are activated • medium & hard maneuvers; if five (in two groups) nozzles are activated • hard & hard maneuvers; if six (in two groups) nozzles are activated figure 2. smart missile algorithm k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 59 there is an equation for the number of nozzles that are activated, namely medium & medium maneuver and low & hard maneuver, totaling four active nozzles. the difference is, if medium & medium each group activates two nozzles, while for low & hard, the first group activates one nozzle and the second group turns on three nozzles (or vice versa). the hidden layers on the smart missile act as a control nozzle that can change the direction of the missile according to the neurons guidance, to increase the accuracy of the missile during the maneuver. c. missile maneuver guidance system the missile guidance system functions as a determinant of the direction of the missile towards the target by adjusting the slope of the missile to match the target position. the scheme developed figure 3. backpropagation neural network – feedback missile system detector sensor accel (gyro) x axis:..... y axis:..... z axis:..... accel (missile) x axis:..... y axis:..... z axis:..... right or left ax1 – ax2=...... front or back ay1 – ay2=...... oblique axt : ayt=...... ax1 ax2 < 0 ≥ -3 ax1 ax2 < -3 ≥ -6 ax1 ax2 < -6 ax1 – ax2 > 0 ≤ 3 ax1 – ax2 > 3 ≤ 6 ax1 – ax2 > 6 ay1 ay2 < 0 ≥ -3 ay1 ay2 < -3 ≥ -6 ay1 ay2 < -6 ay1 – ay2 > 0 ≤ 3 ay1 – ay2 > 3 ≤ 6 ay1 – ay2 > 6 target ax1 = ax2 & ay1 = ay2 low manuver medium manuver hard manuver low & low manuver low & medium manuver low & hard manuver medium & hard manuver hard & hard manuver feedback total 72 neuron medium & medium manuver y xx x; y x; y x; y x; y 1 2 3 1 2 3 1 2 3123 1 2 3 1 2 3 1 2 3 1 2 3 0 rightleft front back fr fl brbl (example) one group nozzle (example) two group nozzle y figure 4. nozzle position hidden layers k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 60 can control the missile direction against randomly coming targets by utilizing the neural network. the missile uses the degree of freedom (dof) system on the gyroscope by calculating the axis data from the accelerometer. by using dof dynamics as a variable calculation, the technology of the nozzle on the missile body allows the missile to maneuver perfectly towards the locked target and can minimize disturbance from air pressure. there are 24 nozzles attached to the missile body as shown in figure 4. the number of nozzles that are activated depends on the data obtained by the sensor. nozzle technology is very commonly used in missiles, both as the main booster and control attitude body missile. the target direction and missile condition are processed by the autopilot system as shown in figure 5 which is embedded with an intelligent backpropagation neural network algorithm to optimize missile maneuvers’ accuracy. the autopilot system works after the missile leaves the launcher until it reaches the target, so there is no friction between the missile body and the missile launcher. the auto-pilot system continues to work even though the target changes direction (outwit), and the data from the sensor is continuously processed using the intelligent backpropagation neural network algorithm so the maneuverability is much better and the missile's accuracy level is getting higher. iii. results and discussions the weight produced by the x-axis and y-axis of the missile and target accelerometer is calculated by calculating the ratio and difference of each axis. the training data results show the performance, training state, and gradients of the smart missile system. a. training data results the accelerometer data calculation is trained with the backpropagation neural network algorithm. the algorithm is assembled with 72 neurons of equation neurons connected to nine hidden layers, as well as two types of target data axes (x-axis and y-axis). as in figure 6, the network is trained by entering 1000 max files at each stage. the calculation between the dependent variable and the independent variable on a smart missile sensor is the main target of this research. so that the neural network training method using backpropagation gives high accuracy results and minimal vibrations to maneuver smart missiles towards the target. the increase in maneuver accuracy can be proven by looking at the results of the first training until the last training recorded, in the first training the system only took 9 seconds to detect 1000 failures, while in the last training the system took about 1 minute to detect 1000 failures, this indicates that the system is getting worse. often trained, the errors are minimal, so the system is difficult to find 1000 files in the last training. b. neural network performance the neural network performance on a smart missile displays a train, validation, and test graph as shown in figure 7. the neural network performance graph displays several training stages with a different performance at each stage. the validation graph uses the mean square error (mse) method to hold the test graph so that performance is more stable during training. mse is obtained from the lowest point on the validation graph. when minimizing vibration in missiles, it produces a very significant change from the beginning of the training to the end of the training. figure 5. auto-pilot missile scheme tar get dir ect ion (gy ros cop e) target missile direction detector system missile controll movement (accelerometer) dof gyroscope (accelerometer) missile sensor (auto-pilot) (a) (b) figure 6. train progress: (a) first train; (b) end train k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 61 this can be proven at the initial training with a mass load of 273 to 0. in the final training, and the best point of validation performance was 3,715 (around 100.57) in the initial training, to 0.3423 (about 10-0.46) in the final training. besides that, the initial training chart shows fluctuating shapes, while the final training graph shows a constant form. this can indicate that the system can minimize vibration waves on smart missile systems. c. training state neural network the neural network training state on the smart missile displays a gradient graph and a check validation graph as shown in figure 8. the neural network training graph displays several training stages with different statistics at each stage. gradient graphs and fail graphs that experience changes at every stage of the training. the resulting changes indicate that the gradient value of 1000 iterations is getting smaller and fluctuations are getting smaller too. where the initial gradient value of 7.88 becomes 0.00056, and in the end, the fluctuation disappears in the final training. failure graphs in the training state also display changes in shape at each stage, in the initial stages of a discontinuous graph form with a validated period of 727 out of 1000, then at the final stage of the training state, the shape of the failure graph is not interrupted (continued) with a period of validated by 1000 out of 1000. this indicates that the training stage of the smart missile can guide the missile so that it can maneuver with minimal vibration, so that maneuvers (fail) can be minimized or overcome. d. neural network regression neural network regression in the smart missile to the target displays a single line of perception of training line intercept, validation line intercept, test line intercept, and all line intercept. as shown in figure 9, each training stage displays the different conditions of each line intercept. line intercept in neural network regression shows changes in the independent variables that are increasingly close to the dependent variable from the data of the smart missile sensor results. the most significant change at each stage of the training was shown by the line test, with the difference in (a) (b) figure 7. perform neural network: (a) first train; (b) end train (a) (b) figure 8. state neural network training: (a) first train; (b) end train k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 62 variables of 4.2 at the initial stage of the training being 0.32 at the end of the training. this indicates that the difference between the slope of the target as a fixed variable, and the missile as the independent variable, results in a comparison that approaches the similarity of the axes. so the missile can be in the right maneuver to hit the target. iv. conclusion smart guided missile system using the accelerometer and gyroscope, can guide the missile to the target with a highly accurate difference in variables. the slope between the missile maneuver against the target can be reduced by a difference of 0.32 m/s2. backpropagation neural network with optimal feedback control makes this system able to minimize vibration up to 0.34 m/s2, so that missile maneuvers are much better with minimal zigzag movement. fail that can be detected and validated as a whole, namely 1000 files out of 1000 times (epoch) so the autopilot system can be more regular in adjusting the missile body when maneuvering towards the target. acknowledgement thank you to universitas negeri malang for support in the form of directives, facilities, and research facilities in the form of laboratories for the success and smoothness of this research. declarations author contribution the simulation of the research data was developed by k. faqih. sujito founded the idea of the research and supervise the work. improvement of the english language and structure of the paper was supervised by s. sendari. data collection and layout submission by f. s. aziz. k. faqih, sujito, s. sendari, and f. s. aziz contributed equally as the main contributor to this paper. all authors read and approved the final paper. funding statement this research was funded by sujito from a private sector. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] anthony d’amato, “israel’s air strike against the osiraq reactor: a retrospective,” northwest. univ. sch. law sch. commons, vol. 10 temp. int'l & comp. l.j. 259-264, 2010. [2] e. garcia, d. w. casbeer, z. e. fuchs, and m. pachter, “cooperative missile guidance for active defense of air vehicles,” ieee trans. aerosp. electron. syst., vol. 54, no. 2, pp. 706–721, apr. 2018. [3] m. j. castro-toscano et al., “a methodological use of inertial navigation systems for strapdown navigation task,” in 2017 ieee 26th international symposium on industrial electronics (isie), jun. 2017, pp. 1589–1595. [4] zhang hua and hu xiulin, “a height-measuring algorithm applied to tercom radar altimeter,” in 2010 3rd international conference on advanced computer theory and engineering(icacte), aug. 2010, vol. 5, pp. v5-43-v5-46. [5] m. s. ab-rahman and m. r. hassan, “lock-on range of infrared heat seeker missile,” in 2009 international conference on electrical engineering and informatics, aug. 2009, vol. 02, pp. 472–477. [6] i. f. gibbons and j. j. botha, “tactical radar missile challenges,” in 2015 ieee radar conference, oct. 2015, pp. 46–50. [7] k. günaydin, t. çimen, and o. tekinalp, “response surface based performance analysis of an air-defense missile system,” in 2014 ieee aerospace conference, mar. 2014, pp. 1–10. [8] b. li, g. he, and j. wu, “a research of automatic measuring and test system of some surface-to-air missile autopilot,” in 2009 ieee circuits and systems international conference on testing and diagnosis, apr. 2009, pp. 1–3. [9] t. ender et al., “systems-of-systems analysis of ballistic missile defense architecture effectiveness through surrogate (a) (b) figure 9. neural network regression: (a) first train; (b) end train https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1684325 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1684325 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1684325 https://doi.org/10.1109/taes.2017.2764269 https://doi.org/10.1109/taes.2017.2764269 https://doi.org/10.1109/taes.2017.2764269 https://doi.org/10.1109/taes.2017.2764269 https://doi.org/10.1109/isie.2017.8001484 https://doi.org/10.1109/isie.2017.8001484 https://doi.org/10.1109/isie.2017.8001484 https://doi.org/10.1109/isie.2017.8001484 https://doi.org/10.1109/icacte.2010.5579215 https://doi.org/10.1109/icacte.2010.5579215 https://doi.org/10.1109/icacte.2010.5579215 https://doi.org/10.1109/icacte.2010.5579215 https://doi.org/10.1109/iceei.2009.5254691 https://doi.org/10.1109/iceei.2009.5254691 https://doi.org/10.1109/iceei.2009.5254691 https://doi.org/10.1109/iceei.2009.5254691 https://doi.org/10.1109/radarconf.2015.7411852 https://doi.org/10.1109/radarconf.2015.7411852 https://doi.org/10.1109/aero.2014.6836276 https://doi.org/10.1109/aero.2014.6836276 https://doi.org/10.1109/aero.2014.6836276 https://doi.org/10.1109/cas-ictd.2009.4960769 https://doi.org/10.1109/cas-ictd.2009.4960769 https://doi.org/10.1109/cas-ictd.2009.4960769 https://doi.org/10.1109/cas-ictd.2009.4960769 https://doi.org/10.1109/jsyst.2010.2045541 https://doi.org/10.1109/jsyst.2010.2045541 k. faqih et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 55-63 63 modeling and simulation,” ieee syst. j., vol. 4, no. 2, pp. 156– 166, jun. 2010. [10] guo-min zheng and hui gu, “research on availability simulation of surface-to-air missile weapon systems,” in 2010 international conference on computer design and applications, jun. 2010, vol. 5, pp. v5-99-v5-103. [11] x. fu and m. chen, “missile location based on missile-borne bistatic sar,” in 2014 seventh international symposium on computational intelligence and design, dec. 2014, vol. 2, pp. 232–235. [12] k. faqih et al., “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” j. mechatron. electr. power veh. technol., vol. 10, no. 1, art. no. 1, dec. 2019. [13] h. modares, f. l. lewis, and z.-p. jiang, “optimal outputfeedback control of unknown continuous-time linear systems using off-policy reinforcement learning,” ieee trans. cybern., vol. 46, no. 11, pp. 2401–2410, nov. 2016. [14] x. lidan, z. ke’nan, c. wanchun, and y. xingliang, “optimal control and output feedback considerations for missile with blended aero-fin and lateral impulsive thrust,” chin. j. aeronaut., vol. 23, no. 4, pp. 401–408, aug. 2010. [15] j. sun, c. liu, and j. dai, “robust optimal control for missiletarget guidance systems via adaptive dynamic programming,” in 2018 chinese automation congress (cac), nov. 2018, pp. 836–841. [16] f. l. lewis, optimal estimation: with an introduction to stochastic control theory, 1 edition. new york: wileyinterscience, 1986. [17] t. herlambang, e. b. djatmiko, and h. nurhadi, “navigation and guidance control system of auv with trajectory estimation of linear modelling,” in 2015 international conference on advanced mechatronics, intelligent manufacture, and industrial automation (icamimia), oct. 2015, pp. 184–187. [18] t. herlambang, e. b. djatmiko, and h. nurhadi, “ensemble kalman filter with a square root scheme (enkf-sr) for trajectory estimation of auv segorogeni its,” int. rev. mech. eng. ireme, vol. 9, no. 6, pp. 553-560–560, nov. 2015. [19] d. luo, j. zhang, and y. liu, “autopilot design for bank to turn missile,” in 2016 12th ieee international conference on control and automation (icca), jun. 2016, pp. 401–406. [20] s. s. mehta, w. mackunis, and j. w. curtis, “adaptive visionbased missile guidance in the presence of evasive target maneuvers,” ifac proc. vol., vol. 44, no. 1, pp. 5471–5476, jan. 2011. [21] j. farlik, “simulation of surface-to-air missile units: cluster design,” in international conference on military technologies (icmt) 2015, may 2015, pp. 1–6. [22] s. lee, n. cho, and y. kim, “missile guidance based on tracking of predicted target trajectory,” in 2018 26th mediterranean conference on control and automation (med), jun. 2018, pp. 229–234. [23] d. e. rumelhart, “hinton and williams, rj (1986):‘learning internal representations by error propagation,’” parallel distrib. process., vol. 1, 1986. [24] z. deyun and z. feng, “data fusion control and guidance of surface-to-air missile under the complex circumstance based on neural-net technology,” j. syst. eng. electron., vol. 19, no. 5, pp. 996–1002, oct. 2008. [25] y.-j. liu, j. li, s. tong, and c. l. p. chen, “neural network control-based adaptive learning design for nonlinear systems with full-state constraints,” ieee trans. neural netw. learn. syst., vol. 27, no. 7, pp. 1562–1571, jul. 2016. [26] v. amrizal and q. aini, kecerdasan buatan. halaman moeka publishing, 2013. [27] d. huang, s. huang, y. tang, w. zhao, and w. cao, “matching algorithm of missile tail flame based on back-propagation neural network,” in fourth seminar on novel optoelectronic detection technology and application, feb. 2018, vol. 10697, p. 1069702. https://doi.org/10.1109/jsyst.2010.2045541 https://doi.org/10.1109/jsyst.2010.2045541 https://doi.org/10.1109/iccda.2010.5540867 https://doi.org/10.1109/iccda.2010.5540867 https://doi.org/10.1109/iccda.2010.5540867 https://doi.org/10.1109/iccda.2010.5540867 https://doi.org/10.1109/iscid.2014.106 https://doi.org/10.1109/iscid.2014.106 https://doi.org/10.1109/iscid.2014.106 https://doi.org/10.1109/iscid.2014.106 https://doi.org/10.14203/j.mev.2019.v10.36-47 https://doi.org/10.14203/j.mev.2019.v10.36-47 https://doi.org/10.14203/j.mev.2019.v10.36-47 https://doi.org/10.14203/j.mev.2019.v10.36-47 https://doi.org/10.1109/tcyb.2015.2477810 https://doi.org/10.1109/tcyb.2015.2477810 https://doi.org/10.1109/tcyb.2015.2477810 https://doi.org/10.1109/tcyb.2015.2477810 https://doi.org/10.1016/s1000-9361(09)60234-x https://doi.org/10.1016/s1000-9361(09)60234-x https://doi.org/10.1016/s1000-9361(09)60234-x https://doi.org/10.1016/s1000-9361(09)60234-x https://doi.org/10.1109/cac.2018.8623174 https://doi.org/10.1109/cac.2018.8623174 https://doi.org/10.1109/cac.2018.8623174 https://doi.org/10.1109/cac.2018.8623174 http://www.worldcat.org/oclc/989553785 http://www.worldcat.org/oclc/989553785 http://www.worldcat.org/oclc/989553785 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.1109/icamimia.2015.7508028 https://doi.org/10.15866/ireme.v9i6.6341 https://doi.org/10.15866/ireme.v9i6.6341 https://doi.org/10.15866/ireme.v9i6.6341 https://doi.org/10.15866/ireme.v9i6.6341 https://doi.org/10.1109/icca.2016.7505310 https://doi.org/10.1109/icca.2016.7505310 https://doi.org/10.1109/icca.2016.7505310 https://doi.org/10.3182/20110828-6-it-1002.03258 https://doi.org/10.3182/20110828-6-it-1002.03258 https://doi.org/10.3182/20110828-6-it-1002.03258 https://doi.org/10.3182/20110828-6-it-1002.03258 https://doi.org/10.1109/miltechs.2015.7153687 https://doi.org/10.1109/miltechs.2015.7153687 https://doi.org/10.1109/miltechs.2015.7153687 https://doi.org/10.1109/med.2018.8442895 https://doi.org/10.1109/med.2018.8442895 https://doi.org/10.1109/med.2018.8442895 https://doi.org/10.1109/med.2018.8442895 https://dl.acm.org/doi/10.5555/104279.104293 https://dl.acm.org/doi/10.5555/104279.104293 https://dl.acm.org/doi/10.5555/104279.104293 https://doi.org/10.1016/s1004-4132(08)60187-5 https://doi.org/10.1016/s1004-4132(08)60187-5 https://doi.org/10.1016/s1004-4132(08)60187-5 https://doi.org/10.1016/s1004-4132(08)60187-5 https://doi.org/10.1109/tnnls.2015.2508926 https://doi.org/10.1109/tnnls.2015.2508926 https://doi.org/10.1109/tnnls.2015.2508926 https://doi.org/10.1109/tnnls.2015.2508926 http://www.halamanmoeka.net/2013/09/kecerdasan-buatan-q-aini-victor-amrizal.html http://www.halamanmoeka.net/2013/09/kecerdasan-buatan-q-aini-victor-amrizal.html https://doi.org/10.1117/12.2305884 https://doi.org/10.1117/12.2305884 https://doi.org/10.1117/12.2305884 https://doi.org/10.1117/12.2305884 https://doi.org/10.1117/12.2305884 i. introduction ii. materials and methods a. missile architecture b. backpropagation neural network missile algorithm c. missile maneuver guidance system iii. results and discussions a. training data results b. neural network performance c. training state neural network d. neural network regression iv. conclusion acknowledgement declarations author contribution funding statement this research was funded by sujito from a private sector. conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.102-110 2088-6985 / 2087-3379 ©2020 research center for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor estiko rijanto a, *, erik adiwiguna a, aryo putro sadono a, muhammad hafil nugraha a, oka mahendra b, rendra dwi firmansyah b a research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 20, bandung, 40135, indonesia b technical implementation unit for instrumentation development, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 30, bandung, 40135, indonesia received 12 october 2020; accepted 24 november 2020; published online 22 december 2020 abstract in modern sugarcane farms, sugarcane chopper harvesters are becoming widely used. a modern sugarcane chopper harvester is essentially a mechatronic system composed of a tractor and some implements with several electro-hydraulic control systems. those control systems are controlled by electronic controller units (ecus). it may fail during harvesting operation due to lack of maintenance, operator's awareness, skill, and field contour. this paper presents a new design of an embedded monitoring system for maintenance and production performance monitoring of a sugarcane chopper harvester in a real-time manner. a prototype of the embedded monitoring system was developed which partially realized the designed system. the experimental result showed that the main computer could communicate with other ecus using a controller area network (can) bus. the dataset from four channels retrieved from the can bus represents the real values originating from the temperature sensor simulators. apart from being sent to the can bus, the data are also recorded on a secure digital (sd) card and sent to the internet of things (iot) server. in the update time interval testing, the 100 ms interval does not give any error. ©2020 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: embedded system; cane harvester; electro-hydraulic; control system; tractor maintenance; can bus. i. introduction agricultural machinery is transforming from an integrated mechanical system into an integrated mechatronic system where electronics and computers are intensively used. such a mechatronic system enables precision farming where precise sensing and controlling of crucial variables become significantly decisive. robotic technologies are started being used to improve sugarcane production. a computer vision was used for analyzing the quality of sugarcane billets. billet images were captured by ccd and stereovision cameras, and image processing was carried out to classify sugarcane billet damage [1]. a critical review of sugarcane harvester technology was conducted to reduce losses during harvesting process. potentials of improvement in some mechanical elements were identified, including base-cutter and sugarcane feeder mechanism [2]. an extractor platform was fabricated, and the effect of the fan speed, the sugarcane feeding rate, and sugarcane billet length on the impurity rate and sugarcane losses was investigated. the following conclusions were obtained: feeding rate has no significant effect on impurity rate but has a substantial impact on sugarcane losses; fan speed and sugarcane billet length have a considerable influence on impurity rate and cane losses [3]. an electrical and hydraulic control system for a double-row sugarcane chopper harvester was designed using a programmable logic controller (plc) to reduce failure rate and improve harvesting efficiency. several rotational speed sensors were used to monitor the engine, walking speed, cutter motors, etc. a pressure sensor and a dc voltage sensor were used to monitor the pump outlet and power supply. the monitoring system was mainly composed of a plc, i/o modules, a touch screen, and various sensors. data exchange between plc and the touch screen was carried out through a serial * corresponding author. tel: +62-22-2503055; fax: +62-222504773 e-mail address: estiko.rijanto@lipi.go.id https://dx.doi.org/10.14203/j.mev.2020.v11.102-110 https://dx.doi.org/10.14203/j.mev.2020.v11.102-110 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.102-110 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.102-110&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:estiko.rijanto@lipi.go.id e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 103 communication in which the touch screen could display the critical parameters in real-time [4]. a precision agriculture concept was implemented in a sugarcane farm through a yield monitoring system. the monitoring system consists of a mass flow sensor, a global positioning system (gps) receiver, and a data acquisition system. the mass flow sensor was load cells installed at the outlet port of the elevator. field testing results showed that the yield monitoring system is accurate with a mean error of 4.3 % where the maximum error is less than 6.4 % [5]. a control area network (can) bus analyzer (cancase xl log, vector, stuttgart, germany) was utilized to get can message from a tractor diagnostic port. one channel was connected to the tractor bus channel and the other channel to the implement bus channel. the can hardware was connected to a laptop via a usb port, and the data were stored in an ascii file in real-time during field operation. the ascii file record contained both proprietary can bus messages and sae-registered can bus messages. it was filtered to get liquid fuel economy (lfe) messages which had fuel use rate in hexadecimal format. the analysis results revealed the potential to estimate the field efficiency (fe) of the tractor based on tractor fuel consumption [6]. information communication technology (ict) was applied for the traceability of sugarcane harvesting operations in small farms. the cutting head position sensor, odometry sensor, speed sensors, and gps were installed on the sugarcane harvester tractor. various phases of work could be traced, and the machines' operating conditions could be better understood. data were collected every 6 seconds and were stored in a data acquisition system. the data were saved in a memory card, and at the end of the experiment, data were sent every day via gsm to the cooperative [7]. the activity of the harvesting machine was traced each day based on variables which were divided into five categories, i.e., administrative information (seven variables), temporal information (twenty three variables), spatial and production information (ten variables), technical information (six variables), and spatial information (gis) [7]. a sugarcane harvester may fail during harvesting operations due to lack of maintenance, operator's awareness, skill, and field contour. this paper presents a new design of an embedded monitoring system for maintenance and production performance monitoring of a sugarcane chopper harvester in a real-time manner. in the context of maintenance, the embedded system records several vital variables that significantly affect the harvester's health status. on the other hand, a yield monitoring system can monitor production performance that can discriminate products and impurities. the embedded monitoring system is integrated with the other instruments in the harvester through the control area network (can) bus. this paper is organized as follows. section ii describes an overview of the sugarcane chopper harvester. section iii presents the proposed embedded monitoring system. results and discussion are reported in section iv. finally, a conclusion is drawn in section v. ii. materials and methods a. overview of sugarcane harvester elements 1) mechanical systems nowadays, mechanical sugarcane harvesters are used in some modern sugarcane farms due to their advantages. at present, there exist two types of sugarcane harvesters, i.e., whole stalk harvester and chopper harvester. the entire stalk harvester involves cutting sugarcane as the exclusive right to its base, removing the top, and placing the stalk into heap rows. a grabber-arm loads them into a trailer to be delivered to a sugar mill. the chopper harvester performs a different method to the whole stalk harvester in that the entire cane is topped, cut, and deposited into the feeder. the cane is cut into billets measuring around 20 cm in length by a chopper. impurities are removed by a primary extractor, and the billets are traveled up by a conveyor which delivers them into a trailer through a secondary extractor. a typical sugarcane chopper harvester system is shown in figure 1. it is essentially a tractor that is equipped with unique apparatuses. the apparatuses figure 1. a typical chopper harvester system [8] e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 104 may be classified into ten subsystems, i.e. (1) topcutter; (2) knockdown roller; (3) crop divider; (4) finned roller; (5) base-cutter; (6) feeding rollers; (7) primary extractor; (8) chopper; (9) elevator; and (10) secondary extractor [8]. the top-cutter is used to sever cane tops and then spread them onto the ground. the crop divider gathers the topped cane plants and arranges them in a proper orientation. the knockdown roller pushes the cane top forward when the tractor is moving forward. the base-cutter cuts the base of stalks close to the ground. the feeding mechanisms capture the ends of the stalks and convey the entire stalks rearward into the chopper in which the stalks are cut into billets. the primary extractor is used to separate leafy trash materials from the chopped billets. the elevator lifts the billets and sends them into a trailer. once again, trash materials are discarded by the secondary extractor at the top of the elevator. 2) electro-hydraulic control systems several electro-hydraulic control systems are used as actuators to control the movement of the cane harvester apparatuses. figure 2 illustrates a diagram of an electro-hydraulic control system composed of a hydraulic pump, two electronic controlled manifold blocks, a hydraulic motor, a hydraulic cylinder, and a reservoir. the pump sucks in the hydraulic oil and sends it to the control manifold blocks. the control blocks are electronically controlled by the controller to send the oil back to the reservoir or send the oil to the motor and the cylinder. the cylinder piston is moved forward or backward depending on the control signal from the controller. when controlling the hydraulic motor, the corresponding control block may rotate the engine in a clockwise direction or counterclockwise direction. the power may be fixed or managed by the manifold block. a relief valve is equipped to regulate oil pressure while an accumulator is used to damp severe pressure changes. the hydraulic motor can be used to rotate the base-cutter, the chopper, and the other appropriate mechanical subsystems of the cane harvester. a pressure sensor and a rotational speed sensor may be placed to monitor the oil pressure and speed. these sensors' signals can be used by the controller for maintenance purposes. usually, today's modern cane chopper harvesters are equipped with three rotational speed sensors (for the base-cutter, the chopper, and the primary extractor) and two pressure sensors (for the base-cutter and the chopper). the hydraulic cylinder can control the steering mechanism, the base-cutter height, and the other appropriate mechanical sub-systems of the cane harvester. position sensors are usually placed to measure the steering angle, the base-cutter height, and the elevator slewing angle. 3) embedded systems the embedded system in sugarcane harvester, or in general for robotic agriculture applications, acts as the brain of the vehicle or robots. in these systems, specific application programs are embedded for particular purposes, such as harvesting, seeding, plowing, fertilizing, irrigating, etc. many of these embedded systems are based on a microcontroller, raspberry pi, and plc. xu and cai [4] used a siemens s7-300 plc to construct a double-rows sugarcane harvester control system. xu monitors the temperature, pressure, and liquid level data on the harvester vehicle. naik et al. [9] used a microcontroller lpc2148 to make a robot used for seeding and can measure the depth and optimal distances between crops and their rows. srivastava [10] used arduino to build a plowing automation device with line lasers and potentiometers based on angle calculation devices. jadhav and hambarde [11] used raspberry pi to create an android-based automated irrigation system. this tool monitors temperature, soil moisture, plant height, and width. jerosheja and manifold block 1 manifold block 2 reservoir relay pcb cylinder controllerpump motor valve accumulator figure 2. diagram of electro-hydraulic sub-system e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 105 mythili [12] proposed a solar-powered automated multi-tasking agricultural robot that uses an embedded system based on raspberry pi, with sensors and ultrasonic sensors spraying pesticides and weedicides. patel et al. [13] used ultrasonic sensor fusion for developing real-time monitoring and navigation, including detection of the target and canopy mapping. gupta et al. [14] built an iot-based multipurpose agribot to monitor drip irrigation, fertilizing, temperature (for greenhouse farming), and crop growth by a camera. another agribot design, using arduino and soil moisture and temperature sensor, was also proposed by rahul et al. [15]. amandeep et al. [16] built a remotecontrolled vehicle for monitoring temperature, humidity, soil condition, and accordingly, supplies water to the field. kabir et al. [17] proposed an assistant robot and mobile app for managing an indoor farm automatically, including monitoring the concentration of co2 and fertilizing the plant. communication between electronic control units (ecus) and other agriculture machinery instruments usually uses the communication protocol standard iso 11783 [18]. this can improve management activities since it contains the following parts: (1) general standard; (2) physical layer; (3) data link layer; (4) network layer; (5) network management layer; (6) virtual terminal; (7) implement messages layer; (8) drive train; (9) tractor ecu; (10) task controller & management; (11) data dictionary; (12) diagnostic services; (13) file server; and (14) sequence control. figure 3 illustrates an example of hardware-based connectivity between ecus on farm machinery. there is a main bus where all ecus and instruments are connected using hard-wire, including the tractor ecu, implements' ecus, gps, and task controller management computer gateway [19]. nowadays, all producers widely accept can 2.0b to define the physical layer in the isobus protocol. the can logger 5102 gps data logger, with two can interface and a built-in gnss receiver, was directly connected to a farm tractor’s can-bus to log all isobus messages [20]. an example of a can message received from the data logger is shown in figure 4. b. embedded monitoring system design this research aims to design an embedded monitoring system capable of conducting predictive maintenance functionalities and reporting the production performance of a sugarcane chopper harvester. usually, the engine used as the primemover in the cane harvester is equipped with an ecu. the designed embedded system can communicate with the engine ecu and other controllers in the cane harvester through can bus using iso 11783. moreover, the designed embedded system communicates remotely with a farm management information system (fmis) computer through wireless communication networks [21]. 1) monitoring system architecture this paper presents an embedded system shown in figure 5. for maintenance, several sensors are used to measure several variables, i.e., rotational speed, hydraulic pressure, position, fluid level, temperature, distance, voltage, and current. rotational speed sensors are fixed at the base-cutter, the chopper, the primary extractor, and the wheels. pressure sensors are placed at the base-cutter and the chopper. position sensors are used to measure the steering angle and the base-cutter height. level sensors are placed at the cooling water tank and the fuel water filter. temperature sensors are used for temperature monitoring of the hydraulic oil and the cabin. voltage and current sensors are placed at the battery. a set of sensors are fixed for production figure 3. illustration of in-vehicle embedded sub-systems network [18][19] diagnostics to ol interface file server implement ecu hitch transmis sion tractor ecu gps engine sequence controller virtual terminal task control ler mgt. computer gateway tractor / implement b us tractor b us management computer 01.09.2015;11:00:58;236.3;2;3;0cfe45f0;8;00;7f;00;90;65;ff;ff;ff; ti me pgn date ty pemil liseconds can c hannel source address priority data length data b ytes 8-1 figure 4. an example of a can message [20] e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 106 performance measurement; those are load cells and inclination sensors. ultrasound sensors are used to measure the distance between the body of the cane harvester tractor and the ground surface. a global positioning system (gps) receiver is used to measure the position of the cane harvester. a computer vision is designed for two-fold objectives: production monitoring and contour estimation of the field. specifications of the sensors are listed in table 1. all the above sensor signals are read by a data logger connected to a modem that performs telecommunication with other devices remotely. a computer is used to conduct necessary tasks, including retrieving available data from the engine ecu via the can bus, pre-processing data from the sensors before they are sent to the fmis, and processing necessary information from the computer vision. 2) maintenance-oriented monitoring method a maintenance-oriented monitoring method performs predictive maintenance functions to avoid sudden damage when the cane harvester tractor is operated. this function is defined based on the operation and maintenance records of the tractor that has been experienced so far, as well as the life cycle specification provided by the components' manufacturers. since the embedded system is connected with a farm management information system (fmis), the maintenance manager can always monitor the health status of the tractor in a realtime manner. the manager can anticipate spare parts before the harvest season and can predict damage so that preventive handling can be carried out. 3) production performance-oriented monitoring method a new production performance monitoring method is designed to measure yields and impurities. mass flow of the cane is measured using load cells placed at two different places. one signal represents gross mass flow which includes cane and impurities and the other signal represents net mass flow in which the impurities are excluded. load cell signals are compensated against noises due to vibration and inclination of the elevator. billets weights before and after the cleaning processes are instantaneously recorded. the recording data will be used to analyze the effectiveness of the cleaning process and also as a yield monitoring process in a real-time manner. iii. results and discussions a. hardware implementation data-logger hardware that partially realizes the proposed design was developed, as shown in figure 6. the schematic of this data-logger is demonstrated in figure 7. it consists of two esp32 microcontrollers (esp32 devkit module) as the master controller and the slave controller. the master controller handles the functions of reading data from the sensors, can bus communication, recording data to the sd card, and sending it to the internet of things (iot) server. the slave controller was disabled in the present experimental testing, and it will be used as a watchdog to increase system stability. on the datalogger, there is a wemos d1 mini shield functioning as an interface module to the secure digital (s.d.s.d.) card. the data-logger uses the ds3231 rtc module as its real-time clock. the data-logger is connected to the can module which uses sn65hvd230 can bus chip from texas instruments. as a power supply, the data-logger uses two mp1584 step-down power supply modules to produce 5 v and 3.3 v voltages. 5 v voltage is used by esp32 devkit module, while the 3.3 v voltage is used by rtc, sd card, and can bus transceiver module. table 1. sensors specification sensor physical specification electronic signal rot. speed 640 – 1100 rpm 0 – 15000 hz pressure 2500 – 2750 psi 4 – 20 ma proximity 0 – 20 mm 0 – 10 v level 300 – 2000 mm 4 – 20 ma oil temperature 40 – 80°c 9800 – 180 ohm base-cutter height 0 – 1000 mm 0 – 10 v steering cylinder 50 – 2500 mm 0 – 10 v load cell 0 – 100 kg 0 – 5 v distance 30 – 1300 mm 0 – 10 v inclination -60 – 60°c 0.1 – 4.9 v implement ecu 1 engine ecu temperature sensors level sensors position sensors press ure sensors rotational speed s ensors data loggermodem main computer gps computer visioncurrent sensors voltage sensors load cell sensors inclination sensors distance sensors internet cellular can b us iso 11783 protocol implement ecu 2 implement ecu 3 joys tick ecu figure 5. the proposed in-vehicle embedded monitoring system e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 107 b. experimental results the data-logger experimental testing procedure in this research is shown in figure 8. the data-logger simulates the analog sensor rotation speed, pressure, proximity, level, oil temperature, base-cutter height, steering cylinder, load cell, distance, and inclination. since one esp32 consists of six adc channels, two proposed data-loggers are needed for this experiment. the data-logger 1 receives input from the temperature sensors measuring the cabin's temperatures, engine oil, hydraulic oil, and oil cooler system. in contrast, data-logger 2 receives information from other sensors. these two dataloggers are connected to the same can bus, but each message has a unique character as the identifiers for each can controller. if the identifier is correct, the data-logger will send the sensor data values. can message is sent by a computer connected to another esp32 module as a converter rs-232 to the can bus. in addition to sending data on the can bus, the datalogger, namely the master microcontroller, also sends data to the iot dashboard. the iot dashboard displays real-time measurement data and has a data figure 6. the data-logger proposed in this paper: (1) microcontroller esp32; (2) can bus transceiver; (3) power supply 5 v and 3.3 v; (4) s.d.s.d. card; (5) rtc; (6) configuration switches figure 7. data-logger schematic: (1) two microcontrollers esp32; (2) can transceiver sn65hvd230; (3) rtc ds3231; (4) sd card interface; and (5) power supply modules e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 108 exporting feature. the data-logger also records the data to s.d.s.d. card for offline downloading purposes. data that are produced by the data-loggers are incorporated into the can frame. the data are described in figure 9, with an explanation of each piece of the structure is shown in table 2. figure 10 shows a data segment received by the computer through the can bus from the data-logger. the first five rows are can bus header, the first data in the segment is data-logger's data header, and the last eight rows are data packets. the data are represented in ascii decimal. the action of sampling data from the data-logger goes as follows. the first action of send-and-receive orders from the computer is to determine which mode the datalogger is currently in. the second action of sendand-receive is the sampling data. table 3 shows the meaning of the can message in figure 10. eight packets of data were received. since we are simulating only four sensors, the data containing the signal information is present in the first four data packets. the last four data packets are space and can be ignored by the computer. the previous data packet ends with the character c.r.c.r. (ascii = 13) or a carriage return. from the can bus data packets, the computer can read the sensor reading values, as shown in table 4. from table 3 and table 4, we conclude that the data retrieved from the can bus is precisely the same as the data generated by sensor simulators. apart from being sent on the can bus, the data was also sent by the main microcontroller on the data-logger to the iot server. the iot server was built using thingsboard v3.1.1pe with the visualization shown in figure 11 and figure 12. in this dashboard, the real-time data is displayed, and the user can download or export the data to csv (comma separated value) or xls/xlsx (microsoft excel) format. the data were sent to the thingsboard based server with the mqtt protocol. in this testing, thingsboard v3.1.1pe was installed in a private server. as shown in the iot dashboard (figure 11), the sensor's data is read by the analog and digital converter (adc) and sent to the iot server every 5 seconds. if needed, this time interval can be shortened. by default, the server limits a maximum of 300 updates per second and no more than 3000 updates per minute. this limitation is mainly because of database writing time in the server. in the update time interval testing, the 100 ms interval does not give any error. table 3. the meaning of each channel fragmented can message in the experiment channel character 1 43= + 48=0 50=2 54=6 46=. 52=4 48=0 2 43= + 48=0 57=9 54=6 46=. 53=5 48=0 3 43= + 48=0 56=8 54=6 46=. 54=6 48=0 4 43= + 48=0 52=4 52=4 46=. 52=4 48=0 5 – 8 32=(space) 32=(space) 32=(space) 32= (space) 32=(space) 32=(space) 32=(space) 13=end of data table 4. sensor values in the experiment channel sensor variable value (°c) 1 thermocouple type j cabin temperature 26.4 2 engine oil temperature 96.5 3 hydraulic oil temperature 86.6 4 system cooler oil temperature 44.4 data logger 1 data logger 2 computer can bus figure 8. the data retrieval testing using two data-loggers connected to the same can bus stdid extid rtr ide dlc data figure 9. can bus frame message table 2. can bus frame message frame name remarks stdid standard identifier, 1 is used to identify messages from a computer, and 2 for messages from devices extid extended identifier, 1 is used for the first datalogger and 2 for the second data-logger ide identifier type rtr determine whether the message is a standard message or an remote transmission request (rtr) dlc data size, 8 data data data from data-loggers consist of 8 data of byte type figure 10. example of data received from the can bus e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 109 iv. conclusion the designed embedded monitoring system comprises several sensors, a data logger, and the main computer. it is connected to other instruments through a can bus. a prototype of the embedded monitoring system was developed which partially realized the designed system. the experimental result showed that the main computer could communicate with other ecus using the can bus. the dataset from four channels retrieved from the can bus represents the real values originating from the temperature sensor simulators. apart from being sent to the can bus, the data are also recorded on the sd card and sent to the iot server to display real-time data on the dashboard and exported to csv/xls/xlsx for offline data processing purposes. in the update time interval testing, the 100 ms interval does not give any error. acknowledgement the authors would like to thank mr. djohar syamsi from technical implementation unit for instrumentation development, indonesian institute of sciences (lipi) for his valuable suggestions on the instrumentations that have been utilized in the experiment. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research is funded by ministry of research, technology, and higher education under the research contract 61/g2/ppk/e/e4/2019 of ppti program granted to research center for electrical power and mechatronics, indonesian institute of sciences (lipi) in 2019. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. figure 11. iot dashboard for cane harvester monitoring system figure 12. the iot dashboard has the feature to export data into csv, xls, and xlsx formats e. rijanto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 102-110 110 references [1] m. alencastre-miranda, j. r. davidson, r. m. johnson, and h. waguespack, h. i. krebs, “robotics for sugarcane cultivation: analysis of billet quality using computer vision,” ieee robotics and automation letters, vol. 3, no. 4, pp. -, 2018. [2] s. ma, m. karkee, p. a. scharf, and q. zhang, “sugarcane harvester technology: a critical review,” american society of agricultural and biological engineers, vol. 30, no. 5, pp. 727739, 2014. [3] f. wang, g. yang, w. ke, and s. ma, “effect of sugarcane chopper harvester extractor parameters on impurity removal and cane losses,” in ifac-papersonline 51-17 (2018) 292-297, -, 2018. [4] l. xu and l. cai, “design of double-rows sugarcane harvester control system based on plc,” in 7th international conference on education, management, computer and society (emcs 2017), -, 2017. [5] p. s. g. magalhaes and d. g. p. cerri, “yield monitoring of sugar cane,” biosystems engineering, vol. 96, no. 1, pp. 1-6, 2006. [6] s. k. pitla, n. lin, s. a. shearer, and j. d. luck, “use of controller area network (can) data to determine field efficiencies of agricultural machinery,” applied engineering in agriculture, vol. 30, no. 6, pp. 829-839, 2014. [7] d. deurveilher, f. chiroleu, m. chanet, j. p. chanet, and d. boffety, “ict for traceability of sugarcane harvesting operations in small farms,” cigr-ageng. international conference on agricultural engineering, 2012, 6 p. hal00856762. [8] o. yinggang, m. wegener, y. dantong, l. qingting, z. dingke, w. meimei, and l. haochun, “mechanization technology: the key to sugarcane production in china,” int. j. agric&bioleng, vol. 6, no. 1, pp. 1-27, 2013. [9] n. s. naik, v. v. shete, and s. r. danve, “precision agriculture robot for seeding function,” in proc. international conference on inventive computation technologies (icict), 2016. [10] animesh srivastava, aniket srivastava, v. yadav, and r. sood, “a novel approach to low-cost plowing automation device,” in proc. international conference on electrical, electronics and computer engineering (upcon), 2019. [11] s. jadhav and s. hambarde. “android based automated irrigation system using raspberry pi,” international journal of science and research (ijsr), vol. 5, pp. 2345–2351, may 2016. [12] b. r. jerosheja and c. mythili, “solar powered automated multi-tasking agricultural robot,” in proc. international conference on innovative trends in information technology (icitiit), 2020. [13] m. k. patel, h. k. sahoo, c. s. kathuria, m. k. nayak, a. singla, and c. ghanshyam, “navigation control of a mobile robotic system in semi-structured and dynamic environment for controlled dose delivery of pesticides,” in proc. international conference on trends in automation, communications and computing technology (i-tact-15), 2015. [14] s. gupta, r. devsani, s, katkar, r, ingale, p. a. kulkarni, and m. wyawhare, “iot based multipurpose agribot with field monitoring system,” in proc. international conference on industry 4.0 technology (i4tech), 2020. [15] d. s. rahul, s. k. sudarshan, k. meghana, k. n. nandan, r kirthana, and p. sure, “iot based solar powered agribot for irrigation and farm monitoring: agribot for irrigation and farm monitoring,” in proc. international conference on inventive systems and control (icisc), 2018. [16] amandeep, a. bhattacharjee, p. das, d. basu, s. roy, s. ghosh, s. saha, s. pain, s. dey, and t.kt.k. rana, “smart farming using iot,” in proc. ieee annual information technology, electronics and mobile communication conference (iemcon), 2017. [17] a. z. m. t. kabir, a. m. mizan, n. debnath, a. j. ta-sin, n. zinnurayen, and m. t. haider, “iot based low cost smart indoor farming management system using an assistant robot and mobile app,” in proc. electrical power, electronics, communications, controls and informatics seminar (eeccis), 2020. [18] d. s. paraforos, g. m. sharipov, and h. w. griepentrog, “iso 11783-compatible industrial sensor and control systems and related research: a review,” computer and electronics in agriculture, vol. 163, no. -, pp. 1-13, 2019. [19] s. jankovic, m. ivkovic, v. sinik, and d. kleut, “management approach based on iso 11783-10,” journal of engineering management and competitiveness, vol. 2, no. 1, pp. 27-32, 2012. [20] d. kortenbruck, h. w. griepentrog, and d. s. paraforos, “machine operation profiles generated from iso 11783 communication data,” computers and electronics in agriculture, vol. 140, no. -, pp. 227-236, 2017. [21] a. setiawan, wahyuddin, and e. rijanto, “an ict platform design for traceability and big data analytics of sugarcane harvesting operation,” in proc. international conference on computer, control, informatics and its application, 2019. https://doi.org/10.1109/lra.2018.2856999 https://doi.org/10.1109/lra.2018.2856999 https://doi.org/10.1109/lra.2018.2856999 https://doi.org/10.1109/lra.2018.2856999 https://doi.org/10.13031/aea.30.10696 https://doi.org/10.13031/aea.30.10696 https://doi.org/10.13031/aea.30.10696 https://doi.org/10.13031/aea.30.10696 https://doi.org/10.1016/j.ifacol.2018.08.178 https://doi.org/10.1016/j.ifacol.2018.08.178 https://doi.org/10.1016/j.ifacol.2018.08.178 https://doi.org/10.1016/j.ifacol.2018.08.178 https://doi.org/10.2991/emcs-17.2017.232 https://doi.org/10.2991/emcs-17.2017.232 https://doi.org/10.2991/emcs-17.2017.232 https://doi.org/10.2991/emcs-17.2017.232 https://doi.org/10.1016/j.biosystemseng.2006.10.002 https://doi.org/10.1016/j.biosystemseng.2006.10.002 https://doi.org/10.13031/aea.30.10618 https://doi.org/10.13031/aea.30.10618 https://doi.org/10.13031/aea.30.10618 https://doi.org/10.13031/aea.30.10618 https://agritrop.cirad.fr/565832/ https://agritrop.cirad.fr/565832/ https://agritrop.cirad.fr/565832/ https://agritrop.cirad.fr/565832/ https://agritrop.cirad.fr/565832/ https://doi.org/10.3965/j.ijabe.20130601.001 https://doi.org/10.3965/j.ijabe.20130601.001 https://doi.org/10.3965/j.ijabe.20130601.001 https://doi.org/10.3965/j.ijabe.20130601.001 https://doi.org/10.1109/inventive.2016.7824880 https://doi.org/10.1109/inventive.2016.7824880 https://doi.org/10.1109/inventive.2016.7824880 https://doi.org/10.1109/upcon47278.2019.8980184 https://doi.org/10.1109/upcon47278.2019.8980184 https://doi.org/10.1109/upcon47278.2019.8980184 https://doi.org/10.1109/upcon47278.2019.8980184 http://dx.doi.org/10.21275/v5i6.nov164836 http://dx.doi.org/10.21275/v5i6.nov164836 http://dx.doi.org/10.21275/v5i6.nov164836 https://doi.org/10.1109/icitiit49094.2020.9071542 https://doi.org/10.1109/icitiit49094.2020.9071542 https://doi.org/10.1109/icitiit49094.2020.9071542 https://doi.org/10.1109/icitiit49094.2020.9071542 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/itact.2015.7492686 https://doi.org/10.1109/i4tech48345.2020.9102637 https://doi.org/10.1109/i4tech48345.2020.9102637 https://doi.org/10.1109/i4tech48345.2020.9102637 https://doi.org/10.1109/i4tech48345.2020.9102637 https://doi.org/10.1109/icisc.2018.8398915 https://doi.org/10.1109/icisc.2018.8398915 https://doi.org/10.1109/icisc.2018.8398915 https://doi.org/10.1109/icisc.2018.8398915 https://doi.org/10.1109/icisc.2018.8398915 https://doi.org/10.1109/iemcon.2017.8117219 https://doi.org/10.1109/iemcon.2017.8117219 https://doi.org/10.1109/iemcon.2017.8117219 https://doi.org/10.1109/iemcon.2017.8117219 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1109/eeccis49483.2020.9263478 https://doi.org/10.1016/j.compag.2019.104863 https://doi.org/10.1016/j.compag.2019.104863 https://doi.org/10.1016/j.compag.2019.104863 https://doi.org/10.1016/j.compag.2019.104863 https://doi.org/10.5937/jemc1201027j https://doi.org/10.5937/jemc1201027j https://doi.org/10.5937/jemc1201027j https://doi.org/10.5937/jemc1201027j https://doi.org/10.1016/j.compag.2017.05.039 https://doi.org/10.1016/j.compag.2017.05.039 https://doi.org/10.1016/j.compag.2017.05.039 https://doi.org/10.1016/j.compag.2017.05.039 https://doi.org/10.1109/ic3ina48034.2019.8949594 https://doi.org/10.1109/ic3ina48034.2019.8949594 https://doi.org/10.1109/ic3ina48034.2019.8949594 https://doi.org/10.1109/ic3ina48034.2019.8949594 i. introduction ii. materials and methods a. overview of sugarcane harvester elements 1) mechanical systems 2) electro-hydraulic control systems 3) embedded systems b. embedded monitoring system design 1) monitoring system architecture 2) maintenance-oriented monitoring method 3) production performance-oriented monitoring method iii. results and discussions a. hardware implementation b. experimental results iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.88-94 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: zikri et al., “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 88-94, july 2022. study on the production of hydrogen gas from water electrolysis on motorcycle engine zikri a, *, aken derisman a, muslim b, wawan purwanto b, al ichlas imran c, d a program studi mesin otomotif, universitas muhammadiyah riau jl. tuanku tambusai ujung, pekanbaru, 28290, indonesia b jurusan teknik otomotif, universitas negeri padang jl. prof. dr. hamka, padang, 25171, indonesia c mechanical engineering, national central university, no. 300, zhongda rd, taoyuan city, 320317, taiwan d jurusan teknik mesin, universitas halu oleo, kendari anduonohu, kendari, 93232, indonesia received 31 october 2020; 1st revision 8 december 2021; 2nd revision 30 march 2022; 3rd revision 7 april 2022; 4th revision 13 april 2022; accepted 18 april 2022; published online 29 july 2022 abstract the primary emphasis of the research is on how to use hydrogen as an energy source for motorcycle fuel. this is an intriguing hypothesis to explore since, at the moment, fossil energy is used to meet fuel demands, although fossil energy supplies are running limited. as a result, hydrogen energy is an option that may be employed as a fuel substitute utilizing commercial water raw materials and the electrolysis method. the research goal is to demonstrate that electrolysis of water to hydrogen gas may occur while the vehicle is in use, to compute the amount of hydrogen gas generated, and to determine the time the vehicle can be utilized using the gas fuel created. the long-term goal of this study is to create a vehicle powered entirely by hydrogen gas produced by water electrolysis, particularly for motorcycles. the experimental approach was employed in this investigation, with three phases of testing on a carburetor-type motorbike utilizing 1, 2, and 3 liters of pertamax gasoline. the results demonstrated that the process of electrolysis of water into hydrogen gas on motorcycles is possible; however, the amount of gas generated is still quite little. the hydrogen gas generated by this electrolysis method is only 0.06 bar when 1 liter of fuel is used, 0.42 bar when 2 liters of fuel are used, and 0.98 bar when 3 liters of fuel are used. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: alternative fuel; water electrolysis; brown gas. i. introduction motorized vehicles are a major producer of air pollution, especially in big cities. the exhaust gases released by vehicles driven by gasoline and diesel fuel motors contain toxic gases, which can have a very detrimental effect on this environment, containing nitrogen oxides, carbon dioxide, methane, benzene, and also particles. the losses incurred are causing disease in humans, damaging the environment, killing plants and living things, making the earth even hotter, etc. in recent decades, several countries in the world have emphasized the environmental impact of the transportation sector and reduced dependence on petroleum. the depletion of conventional non-renewable fuels is one of the main issues in the modern energy scenario, which makes the state of the energy industry unsustainable, and also causes environmental problems such as the greenhouse effect [1][2]. to reduce toxic gas levels, there have been many developments in motor fuel by producing more complete combustion, one of which is the use of hydrogen derived from water (h2o) [3]. many studies have been developed to evaluate the challenges of transition of using the hydrogen fuel [4]. the steps which involved the implementation of a hydrogen economy have been investigated. the rationale of the hydrogen energy systems and technology has been studied including the present energy systems and their environmental impact [5]. the same thing was also expressed by [6] who stated that hydrogen fuel is known as an alternative * corresponding author. tel: +62-82292769324 e-mail: zikri@umri.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.88-94 https://dx.doi.org/10.14203/j.mev.2022.v13.88-94 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.88-94 https://dx.doi.org/10.14203/j.mev.2022.v13.88-94 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.88-94&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 89 energy source and is an effort to overcome the depletion of fossil fuels along with its higher use. also, fossil fuels hurt the environment because the products of combustion gases in the form of carbon oxides, nitrogen, sulfur, etc. are one of the main causes of global warming. therefore, hydrogen fuel is considered an alternative fuel and energy source and can be produced from environmentally friendly sources. to supply the energy demands of the more rapidly increasing global population, it is essential to upgrade to an alternative, sustainable energy source that does not negatively affect the environment [7][8]. the use of alternative fuels in internal combustion engines [9][10][11] can reduce dependence on petroleum-based fuels, where which is a step forward to maintain the security and availability of energy sources [12]. vehicles fuelled by hydrogen dramatically reduce dependence on fossil fuel resources and significantly mitigate tailpipe emissions [13]. hydrogen fuel produced from renewable energy resources through water electrolysis is one way to separate hydrogen and oxygen atoms from water or the resulting gas from this electrolysis process is better known as hho or brown gas [14]. hydrogen gas can be used as alternative energy, apart from being a fuel, hydrogen does not cause pollution, and is colorless and odorless [15]. hydrogen production from renewables is always environmentally friendly, whereas the hydrogen produced from nonrenewables emits greenhouse gases (ghg) [16][17]. figure 1 shows the water electrolysis circuit. figure 1 is a water electrolysis circuit. the main circuit in the electrolysis of water consists of an anode (positive), a cathode (negative), and an electrolyte. these two poles are included in the electrolyte (water) and the current source according to their respective poles. from this process, brown gas will be formed. hydrogen has greater potential for use as a fuel in the future. it is estimated that, by the year 2030, the cost of fuel cells will be competitive with ices based on the technological improvements being made and the increased availability. until now, many studies have stated that the amount of hydrogen produced from renewable energy sources through water electrolysis is too small and the highest amount is still produced from fossil fuels. because of the advantages and flexibility of hydrogen fuel, in the long run, hydrogen will be an alternative to hydrocarbon fuels. hydrogen fuel is also considered the highest energy-efficient and clean because it only produces water from its combustion. most countries in the world have accepted to use of hydrogen fuel as an independent clean energy source that has a high energy content compared to fossil fuels. even though hydrogen fuel is a clean and sustainable energy source, it has so far only been used in motorized vehicles such as automobiles, buses, and others. the hydrogen gas required as the fuel is produced by huge gas generators and requires the same refilling stations as other fossil fuels. the novel aspect of this research is the use of hydrogen gas fuel in a low-cost vehicle, such as a two-wheeled vehicle. until now, there have not been many studies that try to reveal the amount of hydrogen gas that can be produced through the electrolysis of water in vehicles. if this can be realized, it will create discoveries that can be applied to society. departing from this problem, an effort is needed to create a vehicle that uses hydrogen gas, because hydrogen fuel has become an alternative energy source that can be produced from environmentally friendly sources, and what is no less important is that it will only produce water from its combustion. therefore, this research aims to try to prove that the electrolysis process of water into hydrogen gas can occur when the vehicle is used, determine the amount of hydrogen gas produced when the vehicle uses fossil fuels 1, 2, and 3 liters, and determine how long the vehicle can be turned on and used by using the resulting gas fuel. ii. materials and methods a. materials the material used in this study can be seen in table 1 below. table 1 shows the main materials used. to produce water electrolysis process. the anode and cathode materials in this study used 316 stainless steel plates (the best quality stainless steel), and the reactor tube used acrylic material with thicknesses 5 and 6. to function properly, several supporting components such as pressure gauge, water filter regulator, hoses, cables, and more. figure 1. water electrolysis circuit [18] table 1. materials used no. material amount specification 1. stainless steel plate 316 2x9x7 mm 18 shetts stainless stell 316 2. acrylic box 18x11x10 mm 1 unit thickness 5 3. acrylic tube φ70x250 2 units thickness 6 4. pressure gauge 1 bar 1 unit skon 2,5” 5. air filter regulator 1 unit/set tekiro 0,25” 6. 1.5mm cable 3 meters 7. cable skund 4 pieces 8. 1/4” hose 3 meters 9. 1/4” tap stop 3 units hato ¼” 10 bolt 2 pieces m12x1,5 11. acrylic glue 1 box crystal high 12. brass pipe φ1/4” 1 meter 13. bolt φ5 1 meter 14. nut 50 pieces zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 90 b. methods in this research, the method used is the experimental method. according to sugiyono, experimental research is a research method used to find the effect of certain treatments on others under controlled conditions. meanwhile, [19] stated that experimental research is a research situation in which at least one variable called the experimental variable is manipulated or controlled, or varied by the researcher. from the two definitions above, it can be concluded that experimental research is research that aims to find a causal relationship between the independent variable and the dependent variable, where the independent variable is controlled and controlled to determine the effect on the dependent variable. the stages of the experimental method in this study can be seen from the research flow chart in figure 2. briefly, the diagram of this research begins with the process of cutting and assembling a 316 stainless steel plate into a reactor. after the reactor is complete, the next step is to add fluid in the form of water into the reactor tube as well as flow the electric current from the alternator/ motorcycle prok battery to the reactor anode and cathode. with the flow of electricity from the prok battery to the reactor, the electrolysis process occurs in the reactor tube which can produce hydrogen gas. the resulting gas is then channeled to the cooling tube and storage tube for further use as fuel for motorbikes through the carburetor. to get the research results following the flow above, the researchers conducted initial tests on motorbikes using 1 liter, 2 liters, and 3 liters pertamax fuel. this parameter is used because the average motorcycle fuel tank capacity is only 4-5 liters. the conditions when the fuel tank is full, will very rarely occur in the field. therefore, the researcher took the value of 1 3 liters as the sample of this study. as long as the motorcycle is on, it will automatically produce hydrogen gas through the electrolysis process that occurs in the water in the presence of an electric current generated by the engine through the alternator/ prok battery. the volume and pressure of hydrogen gas produced are calculated according to the amount of fuel used up. then the pertamax supply on the motorbike is turned off so that it is replaced with the hydrogen gas produced earlier. to do this, a reactor is needed. the reactor is a device designed to produce gas, which requires a dc electric current to decompose water into gas. inside the reactor, several stainless plate plates function as decomposing water into gas. the electrolysis reactor will separate the water element into the gas element so that it can be used for the combustion process on a motorcycle. plate plates have many types and shapes, including their quality. the quality of the plates is very influential in the electrolysis process, the better the plates used, the perfect gas will be produced. in this tool, the researchers used a 316 stainless plate (the best quality), and as an insulator, a rubber figure 2. research diagram assemble the stainless plate 3161 into a reactor draws electricity from the alternator there is an electrolysis process in water hydrogen gas is formed measure the pressure of the hydrogen gas produced measure the incoming voltage and current hydrogen gas is channeled into the cooling tube and storage tube hydrogen gas enters the carburetor through the gauge fossil fuel measuring the length of time hydrogen gas can be used result analysis conclusion alternator zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 91 material with a thickness of 5 mm was used. this rubber is resistant to heat generated by the plate plates. the following is a picture of the water electrolysis system used in this study. figure 3 shows a schematic of the electrolysis process that will be used in this study. in the reactor, electrolysis will occur if it is given a dc electric voltage so that gas pressure can occur. the gas produced will be input through a hose to the gas filter which functions as a separator for wet gas and dry gas. next, the dry gas is fed back into the bubbler tube to produce hydrogen and oxygen gas. then the gas is put into the bubbler (cooling) tube, then it is expelled through the valve (gas valve) and immediately flowed to the motorcycle carburetor as a substitute for the fossil fuel. for the first step, an experiment will be carried out on a motorcycle by making a dual fuel system consisting of fossil fuels and hydrogen gas as a result of the water electrolysis process when using these fossil fuels. using this dual-fuel system provides more economic value than the technology used today. in the future, this research is expected to produce 100 % hydrogen gas-fueled vehicles, especially motorbikes. c. tool assembly and installation process in testing the design of a gas-fired motorcycle, a single tube is used which functions as a reactor in the electrolysis process of water to hydrogen gas. the reactor tube is made using acrylic material with a thickness of 5 mm and dimensions of 18x11x10 mm. in this reactor tube, 4 holes are made, of which two 5 mm holes are used as the reactor installation (anode and cathode). one hole measuring 6 mm is used as an outlet for electrolyzed gas, and another hole with a size of m12x1.5 which functions as a channel for the intake of water to be used for the electrolysis process. besides, 2 tubes were also made, each of which functions as a gas cooling tube and a gas storage tube. the cooling tube and gas storage tube are made using acrylic material with dimensions of diameter 70 mm, height 250 mm, and thickness of 6 mm. in the gas cooling tube, 3 holes are made. one hole serves as the gas inlet from the reactor with a diameter of 10 mm. the second hole with a diameter of 6 mm is used for the conduit from the cooling tube to the gas storage tube. the third hole with a size of m12x1,5 is used as the gas cooling water inlet. figure 4 shows a picture of the reactor tube. to produce an electrolysis process in the reactor tube, a series of electrodes is made by combining 9 sheets of stainless steel with a size of 2x9x7 mm which functions as an anode (positive pole), and 9 other sheets of the stainless plate as a cathode (negative pole) in the reactor. to join this stainless plate, m6 bolts and nuts are used, and rubber with a thickness of 5mm is used as an insulator. after the electrode assembly is complete, the next step is to attach the anode and cathode to the reactor tube. the electrodes are paired alternately with each other and locked into the reactor tube. figure 5 is an electrolysis reactor tube that has been assembled and placed in the trunk of a motorbike that is used. the size of the reactor tube is adjusted to the size of the motorcycle trunk. the next process is to install the reactor, cooling tube, and storage tube on the motorcycle. the electrolysis reactor is placed in the trunk of the motorcycle, as figure 3. electrolysis process schematic figure 4. reactor tubes zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 92 well as the cooling tube and storage tube on the left and right of the motorcycle wing. the next process is to install the connecting hose between the reactor tube, cooling tube, and gas storage tube to the carburetor. between the cooling tube and the storage tube, a gas filter is attached so that the water vapor that enters the storage tube can be filtered first. figure 6 is a gas cooling tube and a gas reservoir resulting from electrolysis. each tube is placed on the left and right sides of the motorcycle. the cooling tube serves to cool the electrolyzed gas for further distribution to the storage tube and motorcycle carburetor. the next step is filling the electrolyte solution (water) into the reactor tube and gas cooling tube, as well as installing an electric current source. the current source for the electrolysis process is taken directly from the alternator/motorcycle prok battery. the purpose of taking direct current sources is that the resulting current is higher according to the rpm and speed of the motorbike. here's a picture of the installation series. figure 7 is the arrangement of the electrical current source cable installation used for the electrolysis process. the current source is taken directly from the motorcycle battery output. in addition, there is also a gas hose installation from the gas storage tube to the carburetor through several taps. iii. results and discussions to test the design of a hydrogen-fueled motorcycle, one motorcycle is needed. the motorbike used is the honda blade 110 cc with a voltage specification of 12 volts and a strong current of 5 amps. this motorcycle was chosen because it still uses a carburetor, a large trunk as an electrolysis reactor, and a wide motor wing as a place to place the cooling tube and gas storage tube. a. test result data the first step is testing the results of the electrolysis of water into hydrogen gas by carrying a road motorcycle using pertamax fuel in stages. the results of this test can be seen from the gas pressure resulting from the electrolysis process. in this study, researchers tested three times. the researcher aimed to test three times so that real data was produced so that further conclusions could be obtained. for each test, the researcher uses the same amount of fuel, but the time required to spend the fuel is different according to the road conditions that the author is going through during the road trial. the first test was carried out using one liter of pertamax fuel. the second test uses two liters of pertamax and the third test uses 3 liters of pertamax. each of the above tests was carried out three times. the following is a table of the results of the tests carried out. table 2 illustrates that from the three tests the results of electrolysis still produce relatively small gas and have not been able to start the motorcycle. the increase in the amount of gas produced was relatively stable between each experiment. b. analysis results before the experiment was carried out, a motorcycle exhaust emission test was conducted first. an emission test is conducted to see the difference in exhaust gas emissions between motorbikes using pertamax fuel and motorbikes using hydrogen gas fuel. from the results of figure 6. cooling cylinders and gas reservoirs figure 7. installation series table 2. test result table testing fuel (l) time required (minutes) gas generated (bar) motorcycles can be started (minutes) i 1 58 2 124 3 180 ii 1 54 0.05 2 118 0.40 3 176 0.96 iii 1 56 0.06 2 121 0.42 3 183 0.98 figure 5. installation of the reactor to the motorcycle zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 93 emission testing with the use of pertamax fuel, it is obtained that the emission value is still under the euro 2 standard. after the emission test is carried out, the next step is to test the electrolysis of water into hydrogen gas on a motorcycle. from the test, it was found that the electrolysis of water into hydrogen gas on motorbikes can occur, it's just that the gas produced is still very little. in the first test, it is shown that no gas pressure is generated at all from this electrolysis process. after analyzing and observing it, it was found that there was a leak in the water filter regulator that the researchers used, where the exhaust valve was in an inverted position, causing the hydrogen gas to be produced to be immediately wasted and not enter the gas storage tube at all. after the researcher found and resolved this problem, the researcher continued to retest for the second and third times. based on the second test that has been carried out, the researchers found that the gas pressure value is still relatively small. the hydrogen gas yield from the results of this second test is only 0.05 bar with the use of one liter of fuel. when the volume of fuel used is increased, the hydrogen gas is greater, namely 0.40 bar. the higher yield of hydrogen gas from the electrolysis process is obtained from the use of 3 liters of fuel, which is 0.96 bar. the following is a graph of the results of the tests carried out. furthermore, the researchers conducted testing iii. based on this test, the hydrogen gas pressure was not too different from the previous test, which was only 0.06 bar with the use of one liter of fuel. when the volume of fuel used is increased, the hydrogen gas is greater, namely 0.42 bar. the higher yield of hydrogen gas from the electrolysis process is obtained from the use of 3 liters of fuel, which is 0.98 bar (figure 8). based on the tests that have been carried out, the researcher found that there was only a very slight difference in the value of each test. the main cause of the amount of gas produced in the current generated from the alternator/prok battery of a motorcycle is still very low. the above matter is following the results of the tests carried out, where the gas bubbles produced in this electrolysis process are classified as small and very few. another cause that the researchers found was the inappropriate use of the arrangement, circuit, and the number of reactor cells. this is due to the adjustment of the shape and arrangement of the reactor cell with the luggage compartment on the motorcycle used. it is hoped that further research will use the best reactor cell arrangement and use a motorcycle with a higher current strength specification. iv. conclusion several conclusions may be taken from the tests that have been conducted, namely the process of electrolyzing water into hydrogen gas may take place on motorcycles; however, the amount of gas generated by this electrolysis process is still quite modest. this is owing to the motorbike's extremely low voltage and high current. the hydrogen gas produced by this electrolysis method has a pressure of just 0.06 bar when using one liter of fuel, 0.42 bar when using two liters of fuel, and 0.98 bar when using three liters of fuel. the motorcycle cannot be started in this test since the amount of hydrogen gas generated is still relatively low, at 0.06 bar. so basically, the use of a water fuel cell cannot stand figure 8. water electrolysis result 0.05 0.4 0.96 0.06 0.42 0.98 0 0.2 0.4 0.6 0.8 1 1 liters 2 liters 3 liters h yd ro ge n g as p ro du ce d (b ar ) fuel use water electrolysis result testing ii testing iii zikri et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 88-94 94 alone and must be combined with other energy sources such as fuel on a motorcycle. the water fuel cell can be an alternative to reduce motorcycle fuel usage. further research and development from this research are needed until the hydrogen gas obtained from the electrolysis of water can be maximized and can be used as motorcycle fuel. acknowledgment thank you very much to the beginner lecturer research (pdp), a program of the mendikbud directorate general of higher education declarations author contribution zikri: writing original draft, concept and design, tool assembly, design trial, data retrieval, analysis, and supervision. aken derisman: determination of tool and materials, purchase of tool and materials, design trial, analysis. muslim: analysis, writing review & editing, article revision. wawan purwanto: analysis, writing review & editing, article drafting, article revision. al ichlas imran: analysis, writing review & editing, article translation, article revision. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] m. derbeli, o. barambones, and l. sbita, “a robust maximum power point tracking control method for a pem fuel cell power system,” applied sciences, vol. 8, no. 12, 2018. [2] s. ehsan, m. abdul, and n. aghili, “the scenario of greenhouse gases reduction in malaysia,” renew. sustain. energy rev., vol. 28, no. december 1997, pp. 400–409, 2013. [3] m. s. al amin and n. nurdiana, “pemanfaatan hydrogen dari hho generator sebagai penghemat bahan bakar pada prime mover generator,” pros. semin. nas. ii has. litbangyasa ind., pp. 49–55, 2019. [4] j. andrews and b. shabani, “where does hydrogen fit in a sustainable energy economy ?,” int. energy congress 2012, vol. 49, pp. 15–25, 2012. [5] s. dutta, “a review on production , storage of hydrogen and its utilization as an energy resource,” j. ind. eng. chem., vol 20, no. 4, pp 1148 – 1156, 2014. [6] t. hübert, l. boon-brett, g. black, and u. banach, “hydrogen sensors a review,” sensors actuators, b chem., vol. 157, no. 2, pp. 329–352, 2011. [7] s. ehsan, a. mahmoudzadeh, and m. abdul, “a review on green energy potentials in iran,” renew. sustain. energy rev., vol. 27, pp. 533–545, 2013. [8] y. manoharan et al., “hydrogen fuel cell vehicles; current status and future prospect,” appl. sci., vol. 9, no. 11, 2019. [9] m. i. devi, k. ismail, and a. nur, “techno-economic analysis of biogas utilization as an alternative fuel,” j. mechatronics, electr. power, veh. technol., vol. 5, no. 1, pp. 51–58, 2014. [10] y. putrasari, h. abimanyu, a. praptijanto, a. nur, y. irawan, and s. p. simanungkalit, “experimental investigation of 2nd generation bioethanol derived from empty-fruit-bunch (efb) of oil-palm on performance and exhaust emission of si engine,” j. mechatronics, electr. power, veh. technol., vol. 5, no. 1, pp. 9–16, 2014. [11] r. fajar and h. setiapraja, “the influence of injection timing on performance characteristics of diesel engine using jatropha biodiesel with and without partial hydrogenation,” j. mechatronics, electr. power, veh. technol., vol. 5, no. 1, pp. 59–66, 2014. [12] y. putrasari et al., “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various loads condition,” j. mechatronics, electr. power, veh. technol., vol. 9, no. 2, pp. 49–56, 2018. [13] r. chaubey, s. sahu, o. o. james, and s. maity, “a review on development of industrial processes and emerging techniques for production of hydrogen from renewable and sustainable sources,” renew. sustain. energy rev., vol. 23, pp. 443–462, 2013. [14] r. f. i. muttaqin, abdillah and e. i. w. fathona, “analisys the effect of geometry on electrode plates in hho generators toward hho gases flow rate that be produced,” e-proceeding eng., vol. 5, no. 14, pp. 854–861, 2018. [15] b. v. chauhan, g. p. rathod, and t. m. patel, “an experimental investigation of hho gas and varying compression ratio on performance characteristics of constant speed diesel engine,” iosr j. mech. civ. eng. ver. iii, vol. 13, no. 2, pp. 2320–334, 2016. [16] s. e. hosseini, m. a. wahid, and a. ganjehkaviri, “an overview of renewable hydrogen production from thermochemical process of oil palm solid waste in malaysia,” energy convers. manag., vol. 94, pp. 415–429, 2015. [17] s. e. hosseini, m. a. wahid, m. m. jamil, a. a. m. azli, and m. f. misbah, “a review on biomass-based hydrogen production for renewable energy supply,” international journal of energy research, vol. 39, no. 12, august, pp. 1597–1615, 2015. [18] s. rajendran, r. j. rathish, s. s. prabha, and a. anandan, “green electrochemistry a versatile tool in green synthesis: an overview,” port. electrochim. acta, vol. 34, no. 5, pp. 321– 342, 2016. [19] n. m. ratminingsih, “experimental research in second language instruction,” prasi, vol. 6, no. 11, pp. 31–40, 2010. https://mev.lipi.go.id/ https://dx.doi.org/10.3390/app8122449 https://dx.doi.org/10.3390/app8122449 https://dx.doi.org/10.3390/app8122449 https://dx.doi.org/10.1016/j.rser.2013.08.045 https://dx.doi.org/10.1016/j.rser.2013.08.045 https://dx.doi.org/10.1016/j.rser.2013.08.045 http://litbang.kemenperin.go.id/pmbp/article/view/5691 http://litbang.kemenperin.go.id/pmbp/article/view/5691 http://litbang.kemenperin.go.id/pmbp/article/view/5691 http://litbang.kemenperin.go.id/pmbp/article/view/5691 https://dx.doi.org/10.1016/j.proeng.2012.10.107 https://dx.doi.org/10.1016/j.proeng.2012.10.107 https://dx.doi.org/10.1016/j.proeng.2012.10.107 https://dx.doi.org/10.1016/j.jiec.2013.07.037 https://dx.doi.org/10.1016/j.jiec.2013.07.037 https://dx.doi.org/10.1016/j.jiec.2013.07.037 https://dx.doi.org/10.1016/j.snb.2011.04.070 https://dx.doi.org/10.1016/j.snb.2011.04.070 https://dx.doi.org/10.1016/j.snb.2011.04.070 https://dx.doi.org/10.1016/j.rser.2013.07.015 https://dx.doi.org/10.1016/j.rser.2013.07.015 https://dx.doi.org/10.1016/j.rser.2013.07.015 https://dx.doi.org/10.3390/app9112296 https://dx.doi.org/10.3390/app9112296 https://dx.doi.org/10.14203/j.mev.2014.v5.51-58 https://dx.doi.org/10.14203/j.mev.2014.v5.51-58 https://dx.doi.org/10.14203/j.mev.2014.v5.51-58 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.9-16 https://dx.doi.org/10.14203/j.mev.2014.v5.59-66 https://dx.doi.org/10.14203/j.mev.2014.v5.59-66 https://dx.doi.org/10.14203/j.mev.2014.v5.59-66 https://dx.doi.org/10.14203/j.mev.2014.v5.59-66 https://dx.doi.org/10.14203/j.mev.2014.v5.59-66 https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 https://dx.doi.org/10.14203/j.mev.2018.v9.49-56 https://dx.doi.org/10.1016/j.rser.2013.02.019 https://dx.doi.org/10.1016/j.rser.2013.02.019 https://dx.doi.org/10.1016/j.rser.2013.02.019 https://dx.doi.org/10.1016/j.rser.2013.02.019 https://dx.doi.org/10.1016/j.rser.2013.02.019 https://www.google.com/search?qð=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generators+toward+hho+gases+flow+rate+that+be+pðroduced&rlz=1c1gceo_enid972id972&oq=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generatoðrs+toward+hho+gases+flow+rate+that+be+produced&aqs=chrome..69i57.1016j0j7&sourceid=chrome&ie=utf-8_ https://www.google.com/search?qð=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generators+toward+hho+gases+flow+rate+that+be+pðroduced&rlz=1c1gceo_enid972id972&oq=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generatoðrs+toward+hho+gases+flow+rate+that+be+produced&aqs=chrome..69i57.1016j0j7&sourceid=chrome&ie=utf-8_ https://www.google.com/search?qð=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generators+toward+hho+gases+flow+rate+that+be+pðroduced&rlz=1c1gceo_enid972id972&oq=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generatoðrs+toward+hho+gases+flow+rate+that+be+produced&aqs=chrome..69i57.1016j0j7&sourceid=chrome&ie=utf-8_ https://www.google.com/search?qð=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generators+toward+hho+gases+flow+rate+that+be+pðroduced&rlz=1c1gceo_enid972id972&oq=analisys+the+effect+of+geometry+on+electrode+plates+in+hho+generatoðrs+toward+hho+gases+flow+rate+that+be+produced&aqs=chrome..69i57.1016j0j7&sourceid=chrome&ie=utf-8_ https://www.iosrjournals.org/iosr-jmce/papers/vol13-issue2/version-3/g1302034147.pdf https://www.iosrjournals.org/iosr-jmce/papers/vol13-issue2/version-3/g1302034147.pdf https://www.iosrjournals.org/iosr-jmce/papers/vol13-issue2/version-3/g1302034147.pdf https://www.iosrjournals.org/iosr-jmce/papers/vol13-issue2/version-3/g1302034147.pdf https://www.iosrjournals.org/iosr-jmce/papers/vol13-issue2/version-3/g1302034147.pdf https://dx.doi.org/10.1016/j.enconman.2015.02.012 https://dx.doi.org/10.1016/j.enconman.2015.02.012 https://dx.doi.org/10.1016/j.enconman.2015.02.012 https://dx.doi.org/10.1016/j.enconman.2015.02.012 https://doi.org/10.1002/er.3381 https://doi.org/10.1002/er.3381 https://doi.org/10.1002/er.3381 https://doi.org/10.1002/er.3381 http://dx.doi.org/10.4152/pea.201605321 http://dx.doi.org/10.4152/pea.201605321 http://dx.doi.org/10.4152/pea.201605321 http://dx.doi.org/10.4152/pea.201605321 https://ejournal.undiksha.ac.id/index.php/prasi/article/view/6816 https://ejournal.undiksha.ac.id/index.php/prasi/article/view/6816 introduction ii. materials and methods iii. results and discussions iv. conclusion acknowledgment references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been accredited by national journal accreditation (arjuna) managed by ministry of research and technology, republic indonesia with second grade (peringkat 2, sinta 2). https://sinta.ristekbrin.go.id/jour nals/detail?id=814 postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://sinta.ristekbrin.go.id/journals/detail?id=814 mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.ph p/mev/login need a username/password? go to registration at: http://mevjournal.com/index.ph p/mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 editor-in-chief dr. haznan abimanyu dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia asscociate editor (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi) komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 © 2020 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 foreword from editor-in-chief the mev journal has become an increasingly recognized journal in the past years and is indexed by many internationally recognized indexers greatly due to the dedicated efforts of the outstanding guest editors, the managing editors, and the advisory editors. in this last issue of 2020, seven papers are published come from multidisciplinary topics including mechatronics, electrical power, and vehicular technology. the topics range from smart guided missile to optimization of ozone chamber for fruits/vegetables sterilization. the first paper presents the development an air defence system that can control guided missiles automatically with high accuracy. the second paper reviews the different exoskeleton designs and presents a working prototype of a surface electromyography (emg) controlled exoskeleton to enhance the strength of the lower leg. the third paper analyses the philosophical values of batik to be applied as design in public transportation. the fourth paper describes the purpose to gain an additional lift generated by the surface effect to increase the aerodynamic performance. the fifth paper aims to show a cfd simulation of struts, which affects the aerodynamic of vawt. the sixth paper presents a new design of an embedded monitoring system for maintenance and production performance monitoring of a sugarcane chopper harvester in a real-time manner. the last paper in this issue has the aim to design and optimize the ozone chamber parameter using pulse width modulation (pwm). this journal provides discretion in financial term by waiving the articleprocessing charge, since the first volume. so, we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors for their excellent contributions. bandung, december 2020 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 ii list of contents smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback kamil faqih, sujito, siti sendari, faiz syaikhoni aziz ............................................................................ 55-63 design and development of the semg-based exoskeleton strength enhancer for the legs mikecon cenit, vaibhav gandhi .................................................................................................................. 64-74 a study on the applicability of batik for public transportation design in indonesia yukhi mustaqim kusuma sya’bana, gun bae park ............................................................................... 75-85 pole placement and lqr implementation on longitudinal altitute holding control of wing in surface effect vehicle muhammad nanda setiawan, evan rizky suryana, leo parytta, william andaro ....................... 86-94 numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt) tri admono, yoyon ahmudiarto, amma muliya romadoni, iman abdurahman, agus salim, teguh tri lusijarto, mochammad agoes mulyadi .................................................................. 95-101 a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor estiko rijanto, erik adiwiguna, aryo putro sadono, muhammad hafil nugraha, oka mahendra, rendra dwi firmansyah ..................................................................................................... 102-110 optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables adi waskito, rendra dwi firmansyah, djohar syamsi, catur hilman adritya haryo bhakti baskoro, anisya lisdiana, herkuswyna isnaniyah wahab............................................................................................................... 111-116 complete articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 11, issue 2, 2020 abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. kamil faqih a, sujito b, siti sendari a, faiz syaikhoni aziz a (a electrical engineering postgraduate, electrical engineering department, universitas negeri malang, indonesia; b intelligent power and advance energy system, electrical engineering department, universitas negeri malang, indonesia ) smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 55-63, 9 ill, 0 tab, 27 ref. as a maritime country with a large area, besides the need to defend itself with the military, it also needs to protect itself with aerospace technology that can be controlled automatically. this research aims to develop an air defense system that can control guided missiles automatically with high accuracy. the right method can provide a high level of accuracy in controlling missiles to the targeted object. with the backpropagation neural network method for optimal control output feedback, it can process information data from the radar to control missile’s movement with a high degree of accuracy. the controller uses optimal control output feedback, which is equipped with a lock system and utilizes an accelerometer that can detect the slope of the missile and a gyroscope that can detect the slope between the target direction of the missile to follow the target, control the position, and direction of the missile. the target speed of movement can be easily identified and followed by the missile through the lock system. sampling data comes from signals generated by radars located in defense areas and from missiles. each part’s data processing speed is calculated using a fast algorithm that is reliable and has a level of accuracy and fast processing. data processing impacts on the accuracy of missile movements on any change in the position and motion of targets and target speed. improved maneuvering accuracy in the first training system can detect 1000 files with a load of 273, while in the last training, the system can detect 1000 files without a load period. so the missile can be guided to hit the target without obstacles when maneuvering. (author) keywords: smart missile; backpropagation; neural network; optimal control; output feedback; lock system. mikecon cenit, vaibhav gandhi (department of design engineering and mathematics, middlesex university london, united kingdom) design and development of the semg-based exoskeleton strength enhancer for the legs journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 64-74, 12 ill, 0 tab, 73 ref. this paper reviews the different exoskeleton designs and presents a working prototype of a surface electromyography (emg) controlled exoskeleton to enhance the strength of the lower leg. the computer aided design (cad) model of the exoskeleton is designed, 3d printed with respect to the golden ratio of human anthropometry, and tested structurally. the exoskeleton control system is designed on the labview national instrument platform and embedded in myrio. surface emg sensors (semg) and flex sensors are used coherently to create different state filters for the emg, human body posture and control for the mechanical exoskeleton actuation. the myrio is used to process semg signals and send control signals to the exoskeleton. thus, the complete exoskeleton system consists of semg as primary sensor and flex sensor as a secondary sensor while the whole control system is designed in labview. fea simulation and tests show that the exoskeleton is suitable for an average human weight of 62 kg plus excess force with different reactive spring forces. however, due to the mechanical properties of the exoskeleton actuator, it will require an additional lift to provide the rapid reactive impulse force needed to increase biomechanical movement such as squatting up. finally, with the increasing availability of such assistive devices on the market, the important aspect of ethical, social and legal issues have also emerged and discussed in this paper. (author) keywords: leg-exoskeleton; electromyography based exoskeleton; labview myrio; ethical, societal, and legal concerns. yukhi mustaqim kusuma sya’bana a, gun bae park b (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b industrial design laboratory, art and design faculty, keimyung university, republic of korea) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv a study on the applicability of batik for public transportation design in indonesia journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 75-85, 11 ill, 1 tab, 43 ref. this paper attempts to grant indonesian identity in the development and importing the public transportation equipment from overseas. we reviewed and surveyed the present state issues of indonesian public transportation equipment design development. the study analyzed the philosophical values of batik in a modern way, the possibility of batik application for important regionalism identity, and identity in design development strategy. as a result, we gather and assess the philosophical values of batik motifs that contain geographic origin, the essences, and characteristics to be applied as design element strategies. we found the regional identity of the historical, local wisdom essence, acculturation, various colors, and original shapes of the batik motifs. moreover, indonesian fancy design is also supported by other possibilities indigenous material and technique that usually used, particularly in indonesia. these possibilities were identically indonesian and also applicable as the sustainable public transport equipment design identity issue solution. this effort was conducted as the turning point to solve the issues of public transport equipment design strategies dependency. thus, this research will be helpful for aesthetics research in the modern way of the public transportation equipment design concept. (author) keywords: batik philosophical values; public transportation equipment; national identity; vernacular design. muhammad nanda setiawan a, evan rizky suryana b, leo parytta c, william andaro c (a department of renewable energy engineering, universitas prasetiya mulya, indonesia; b department of engineering physics, multimedia nusantara university, indonesia; c department of physics energy engineering, surya university, indonesia) pole placement and lqr implementation on longitudinal altitute holding control of wing in surface effect vehicle journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 86-94, 7 ill, 6 tab, 20 ref. the longitudinal altitude holding control system (lahcs) of wing in surface effect (wise) vehicle has been developed using simulink/matlab. the lahcs is designed to maintain the altitude of the vehicle stands at 1 m above the surface, with a maximum allowable deviation of 0.5 m. the purpose is to gain an additional lift generated by the surface effect to increase the aerodynamic performance. this control system is investigated using two approaches, i.e., the pole placement and the linear quadratic regulator (lqr) methods. originally, the system shows an unstable response on the phugoid mode, indicated by the positive value of its eigen. after the pole placement method is applied, the system is stable and capable of maintaining the reference command altitude. this method produces 0.27 of the maximum altitude deviation when the disturbance, represented by the doublet input elevator ±5° is applied. moreover, the time needed for the system to reach the steady-state response of altitude is around 2.2 seconds. in comparison, the lqr method is also applied to the system with the same scenario. although the settling time response is quite similar to the previous result, its maximum altitude deviation is significantly reduced by around 80 %. in conclusion, both of the methods used to design the lahcs are capable of maintaining the altitude of the wise vehicle always below its maximum deviation tolerance. (author) keywords: wing in surface effect vehicle; altitude holding control system; pole placement method; linear quadratic regulator (lqr); phugoid mode; doublet input elevator. tri admono a, yoyon ahmudiarto a, amma muliya romadoni a, iman abdurahman a, agus salim a, teguh tri lusijarto a, mochammad agoes mulyadi b (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b department of aeronautics and astronautics, bandung institute of technology, indonesia) numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt) journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 95-101, 10 ill, 3 tab, 15 ref. strut is used in vertical axis wind turbine (vawt) to restraint the framework. in this study, struts are analyzed to show the pressure losses in vawt. ansys computational fluid dynamics (cfd) software is used to investigate triangle strut in vawt. this study aims to show a cfd simulation of struts, which affects the aerodynamic of vawt. in cfd software, the aerodynamic of vawt can be analyzed in terms of pressure losses in the struts. the simulation method starts by making a struts model, then meshing and setting up ansys's boundary conditions. the last iteration runs in ansys until convergence. our results show the percentage of pressure losses with the variation of the angle of wind 0°, 20°, 40°, and 60° are 0.67 %, 0.52 %, 0.48 %, and 0.52 %. the effect of triangle strut in vawt did not affect the wind flow to the vawt blade. the results also indicated that the triangle strut could be applied in the multi-stage of vawt system. (author) keywords: vertical axis wind turbine (vawt); triangle strut; computational fluid dynamics (cfd); pressure losses.. estiko rijanto a, erik adiwiguna a, aryo putro sadono a, muhammad hafil nugraha a, oka mahendra b, rendra dwi firmansyah b (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b technical implementation unit for instrumentation development, indonesian institute of sciences, indonesia) a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 102-110, 12 ill, 4 tab, 21 ref. in modern sugarcane farms, sugarcane chopper harvesters are becoming widely used. a modern sugarcane chopper harvester is essentially a mechatronic system composed of a tractor and some implements with several electrohydraulic control systems. those control systems are controlled by electronic controller units (ecus). it may fail during harvesting operation due to lack of maintenance, operator's awareness, skill, and field contour. this paper presents a new design of an embedded monitoring system for maintenance and production performance monitoring of a sugarcane chopper harvester in a real-time manner. a prototype of the embedded monitoring system was developed which partially realized the designed system. the experimental result showed that the main computer could communicate with other ecus using a controller area network (can) bus. the dataset from four channels retrieved from the can bus represents the real values originating from the temperature sensor simulators. apart journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v from being sent to the can bus, the data are also recorded on a secure digital (sd) card and sent to the internet of things (iot) server. in the update time interval testing, the 100 ms interval does not give any error. (author) keywords: embedded system; cane harvester; electrohydraulic; control system; tractor maintenance; can bus. adi waskito a, rendra dwi firmansyah a, djohar syamsi a, catur hilman adritya haryo bhakti baskoro b, anisya lisdiana c, herkuswyna isnaniyah wahab c (a technical implementation unit for instrumentation development, indonesian institute of sciences, indonesia; b research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; c research centre for geotechnology, indonesian institute of sciences, indonesia) optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables journal of mechatronics, electrical power, and vehicular technology, 2020, vol. 11, no. 2, p. 111-116, 8 ill, 0 tab, 20 ref. ozonizer is a method used for sterilization and food preservation by utilizing ozone produced from plasma discharge. the effective way of obtaining ozone is to use dielectric barrier discharge (dbd) plasma. the manufacture of a controlled ozonizer chamber system is important to result in effective and efficient performance. the aim of this study is to design and optimize the ozone chamber parameter using pulse width modulation (pwm). the system design is added with the arduino mega 2560 microcontroller and the l296n motor driver as an ozone generator radiation controller by changing the pulse width modulation to determine the ozone levels produced. the experimental results show that the ozone concentration increases by 50 % on average with increasing variations of the 10 % duty cycle (pwm) and the ignition time length. the optimum value is achieved on a 70 % duty cycle for 60 300 seconds, where the ozone level of 3 ppm is obtained and sustained for fruits/vegetables sterilization and preservation application. (author) keywords: dielectric barrier discharge; ozone chamber; pulse width modulation; sterilization and preservation. microsoft word vol02_no2_vs journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 2, 2011 issn:2088-6985 (online) iii journal of mechatronics, electrical power and vehicular technology editorial boards editor-in-chief dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com managing editor tinton dwi atmaja, mt. electrical engineering, informatics indonesian institute of sciences tinton_dwi@yahoo.com editors ghalya pikra, mt. mechanical engineering indonesian institute of sciences ghalyapikra@yahoo.com noviadi arief rachman, mt. electrical power engineering indonesian institute of sciences novi001@lipi.go.id aam muharam, mt. electrical engineering indonesian institute of sciences aam.muharam@lipi.go.id copy editor naili huda, m.eng.sc. industrial engineering indonesian institute of sciences naili.huda@lipi.go.id advisory editor dr. ir. rachmini saparita, mt. interdisciplinary engineering indonesian institute of sciences rachmini.saparita@lipi.go.id peer reviewer / mitra bestari prof.dr. jamasri mechanical and industrial engineering gajah mada university jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering bandung institute of technology suhono@stei.itb.ac.id ir. arko djajadi, ph.d. mechatronics engineering swiss german university arko@sgu.ac.id dr. ahmad agus setiawan renewable energy systems gajah mada university a.setiawan@ugm.ac.id dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com ir. edi leksono, m.eng. ph.d. physics engineering bandung institute of technology edi@tf.itb.ac.id dr. endra joelianto engineering physics, instrumentation & control bandung institute of technology ejoel@tf.itb.ac.id dr. ir. iman kartolaksono reksowardojo mechanical engineering bandung institute of technology iman@lmbsp.ms.itb.ac.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id riza muhida, ph.d. mechatronics engineering stkip surya riza.muhida@stkipsurya.ac.id dr. yuliadi erdani information, computer science polteknik manufaktur bandung yul_erdani@polman-bandung.ac.id pudji irasari, m.sc.rer.nat. electrical engineering/electric machines indonesian institute of sciences pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 2, 2011 issn:2088-6985 (online) iv journal of mechatronics, electrical power and vehicular technology volume 2 (2011) author index adi santoso pusat penelitian tenaga listrik dan mekatronik, lipi 31 aditya sukma nugraha pusat penelitian tenaga listrik dan mekatronik, lipi 31, 85 aep saepudin pusat penelitian tenaga listrik dan mekatronik, lipi 73 agus salim pusat penelitian tenaga listrik dan mekatronik, lipi 57 andri joko purwanto pusat penelitian tenaga listrik dan mekatronik, lipi 57 anwar muqorobin pusat penelitian tenaga listrik dan mekatronik, lipi 41, 85 arif santoso pusat penelitian tenaga listrik dan mekatronik, lipi 41, 85 arifin santosa pusat penelitian tenaga listrik dan mekatronik, lipi 73 arko djajadi department of mechatronics, sgu 51 arsi azavi department of mechatronics, sgu 51 dalmasius ganjar subagio pusat penelitian tenaga listrik dan mekatronik, lipi 105 edwar yazid pusat penelitian tenaga listrik dan mekatronik, lipi 95 erikson sinaga department of mechatronics, sgu 51 estiko rijanto pusat penelitian tenaga listrik dan mekatronik, lipi 31, 85 ghalya pikra pusat penelitian tenaga listrik dan mekatronik, lipi 57 hendri maja saputra pusat penelitian tenaga listrik dan mekatronik, lipi 31, 85 irhan febijanto pusat teknologi pengembangan sumberdaya energi, bppt 11 maralo sinaga department of mechatronics, sgu 79 maulana arifin pusat penelitian tenaga listrik dan mekatronik, lipi 73 midriem mirdanies pusat penelitian tenaga listrik dan mekatronik, lipi 31, 85 momoh jimoh e. salami department of mechatronics engineering, iium 65 nani rahayu department of mechatronics engineering, iium 65 noor cholis basjaruddin jurusan teknik elektro, politeknik negeri bandung 23 nurul amalina bt ahmad kasim department of mechatronics engineering, iium 65 pudji irasari pusat penelitian tenaga listrik dan mekatronik, lipi 1 riza muhida stkip surya, surya research and education center 65 rizqi andry ardiansyah pusat penelitian tenaga listrik dan mekatronik, lipi 31, 85 roni permana saputra pusat penelitian tenaga listrik dan mekatronik, lipi 41, 85 rusman rusyadi department of mechatronics, sgu 51, 79 teguh pudji purwanto jurusan teknik mesin dan industri, ugm 41 tinton dwi atmaja pusat penelitian tenaga listrik dan mekatronik, lipi 105 vita susanti pusat penelitian tenaga listrik dan mekatronik, lipi 85 winda astuti department of mechatronics engineering, iium 65 yosafat surya murijanto department of mechatronics, sgu 79 zaidan eddy pusat penelitian tenaga listrik dan mekatronik, lipi 57 journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 2, 2011 issn:2088-6985 (online) v journal of mechatronics, electrical power and vehicular technology volume 2 (2011) affiliation index department of mechatronics engineering, faculty of engineering, international islamic university malaysia (iium) 65 department of mechatronics, faculty of engineering, swiss german university (sgu) 51, 79 jurusan teknik elektro, politeknik negeri bandung 23 jurusan teknik mesin dan industri, universitas gadjah mada (ugm) 41 pusat penelitian tenaga listrik dan mekatronik, lembaga ilmu pengetahuan indonesia (lipi) 1, 31, 41, 57, 75, 73, 85, 95, 105 pusat teknologi pengembangan sumberdaya energi, badan pengkajian dan penerapan teknologi (bppt) 11 stkip surya, surya research and education center 65 journal of mechatronics, electrical power, and vehicular technology issn: 2087-3379 (cetak) vol. 02, no 2, 2011 issn:2088-6985 (online) vi tata cara penulisan redaksi menerima naskah karya tulis ilmiah yang berupa hasil penelitian, pengembangan dan penerapan ilmu pengetahuan dan teknologi pada bidang mekatronik, tenaga listrik, teknologi transportasi and aplikasi perekayasaannya. aturan penulisan naskah adalah sebagai berikut: 1. naskah dikirim melalui e-mail ke sekretariat@mevjournal.com atau dapat melalui pos ke alamat sekretariat dengan menyertakan dua buah hardcopy dan satu buah softcopy. 2. panjang naskah minimal 2.000 kata dan tidak melebihi 10 halaman termasuk gambar dan tabel tanpa lampiran. naskah diketik pada kertas a4 menggunakan word processor baik open office text document (.odt) atau microsoft office word (.doc/.docx). format margin: tepi atas, kanan dan bawah = 2 cm, serta tepi kiri = 2,5 cm. 3. penulisan judul, abstrak dan kata kunci mengikuti aturan berikut: a. judul ditulis dalam bahasa indonesia dan bahasa inggris dengan format; title case, small caps, centered, bold, font type times new roman (tnr), spasi 1. tnr 16 untuk judul indonesia dan tnr 14 untuk judul inggris. b. nama penulis; tanpa gelar, centered, bold, tnr 12, spasi 1. penulis ganda dengan instansi berbeda dibedakan dengan penomoran angka superscript (1) c. alamat instansi dan e-mail; centered, tnr 10, spasi 1. d. judul abstrak ditulis dengan format; justified, bold, tnr 12, spasi 1. isi abstrak ditulis dalam bahasa indonesia tidak melebihi 250 kata dan bahasa inggris tidak melebihi 150 kata tanpa memuat gambar atau tabel. isi abstrak ditulis dengan format; justified, first line indent 5 mm, tnr 10, spasi 1. e. kata kunci (keyword) terdiri dari 3-5 kata dipisahkan koma; justified, tnr 10, spasi 1. 4. penulisan isi naskah mengikuti aturan sebagai berikut. a. isi naskah; ditulis dalam dua kolom, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. b. naskah disusun dalam empat bagian: pendahuluan, isi makalah, hasil dan pembahasan, serta kesimpulan. diikuti ucapan terima kasih (bila diperlukan) dan daftar pustaka. 5. heading dibagi menjadi empat level. heading level 5 tidak dapat diterima. a. heading level 1 ditulis dengan format; title case, small caps, rata kiri, bold, tnr 14, spasi 1, dengan penomoran romawi diikuti titik. (contoh: i. pendahuluan) b. heading level 2 ditulis dengan format; title case, rata kiri, bold, tnr 11, spasi 1, dengan penomoran huruf besar diikuti titik. (contoh: a. pengujian) c. heading level 3 ditulis dengan format; title case, rata kiri, italic, tnr 11, spasi 1, dengan penomoran angka diikuti kurung tutup. (contoh: 1) pengujian lapangan) d. heading level 4 tidak direkomendasikan, namun masih dapat diterima dengan format; sentence case, justified, left indent 5 mm, hanging indent 5 mm, italic, tnr 11, spasi 1, dengan penomoran huruf kecil diikuti kurung tutup. (contoh: a) hasil pengujian lapangan) 6. gambar/tabel harus terbaca dengan jelas, diberi nomor urut dan keterangan ringkas; centered tnr 10, spasi 1. gambar/tabel harus disertai narasi singkat yang mengacu pada nomor gambar/tabel yang bersangkutan. file gambar/tabel disertakan dalam folder terpisah dengan format (.tif/.jpg/.jpeg). 7. persamaan matematik harus ditulis dengan jelas, diberi nomor urut, dan diberi keterangan notasi-notasi. 8. header dan footer termasuk nomor halaman tidak direkomendasikan untuk ditulis. semua hyperlink yang menuju ke suatu url akan dihilangkan. 9. pengutipan dan penulisan daftar pustaka mengikuti gaya penulisan ieee. a. penomoran menggunakan format [1], [2], [3], dst. sesuai urutan kemunculannya dalam naskah b. sumber sejenis wikipedia, blog pribadi atau situs lain yang tidak bersifat ilmiah tidak dapat diterima. c. presentasi sumber acuan primer setidaknya 80% dari paling sedikit sepuluh sumber acuan. d. kemutakhiran pustaka acuan setidaknya lima tahun terakhir. e. contoh penulisan daftar pustaka adalah sebagai berikut: [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ dewan editor berhak menolak suatu naskah yang dianggap tidak memenuhi syarat, setelah mendengar pendapat para ahli. dewan editor berhak mengubah dan menyesuaikan bahasa dan istilah tanpa perubahaan isi, dengan tidak memberitahukan kepada penulis terlebih dahulu. jika perubahaan isi dianggap perlu, maka akan dikonsultasikan dengan penulis. dewan editor mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications pudji irasari a, *, ketut wirtayasa a, b, puji widiyanto a, muhammad fathul hikmawan a, muhammad kasim a, c a research centre for electrical power and mechatronics, indonesian institute of sciences jl. cisitu no. 154d, bandung, 40135, indonesia b department of electrical engineering, national taiwan university of science and technology no. 43, section 4, keelung rd, da’an district, taipei city, 106, taiwan c school of electrical engineering and telecommunications, university of new south wales 330 anzac parade, kensington nsw 2033, australia received 5 january 2021; accepted 2 june 2021; published online 31 july 2021 abstract permanent magnet motors (pmms) are widely used in electric vehicles because of their benefits. based on the permanent magnet topologies on the rotor, pmms are classified into three types: surface mounted pmm, inset pmm, and interior pmm. this paper discusses a comparison of the characteristics of interior and inset types of pmms for electric vehicle applications. the study aims to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. simulations were carried out analytically and numerically using the femm 4.2 software. the simulation results at the base speed show that the interior pmm generates a higher torque but with a lower rotation, namely 56.47 nm and 3162 rpm, respectively, while the inset pmm produces higher rotation 4200 rpm but lower output torque of 46.01 nm. however, with a higher saliency ratio, the interior pmm produces higher maximum torque and speed at both constant torque and field weakening regions than the pmm inset, which is 92.87 nm and 6310 rpm, consecutively. in terms of cogging torque, the interior pmm raises it slightly higher (2.90 nm) than the inset pmm (1.93 nm). the results conclude that, in general, the interior pmm shows better performance in all studied regions and is preferable for electric vehicle applications. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: permanent magnet motor; interior pmm; inset pmm; torque-speed characteristic; cogging torque. i. introduction electric vehicles require traction motors having simple construction that makes them easy to maintenance and manufacture and have high efficiency, reasonable price, and high torque density in a wide speed range [1][2]. however, pmms develop torque ripple stemming from, among others, the cogging torque and the non-sinusoidal electromotive force waveform (emf) in the air gap. this torque ripple causes acoustic noise and vibration, which can reduce the performance of position control and speed control systems, especially at low speeds and high load torque [3][4][5]. studies to eliminate or reducing cogging torque in pmms were discussed by [6][7]. a sinusoidal emf waveform can be obtained by arranging a sinusoidal winding distribution in the stator slots. brushless ac electric motors generate lower electromagnetic torque ripple (about 2 to 8 %) than brushless dc electric motors (about 7 to 30 %) [8]. the improvement of motor performance presented by the torque-speed characteristic is mainly to get an extensive field weakening (fw) range with high torque, as is conducted by [9][10] through controlling the current. however, contradictive problems are usually faced when trying to fix one of the parameters. for example, the fw region can be extended by reducing the flux linkage, but this resulting in lower output torque. also, output torque can be improved by increasing the saliency ratio (lq/ld), but it does not affect the width of the fw region [11]. * corresponding author. tel: +62-22-2503055 e-mail address: pirasari@yahoo.com https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.1-9&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:pirasari@yahoo.com p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 2 there are three possible permanent magnet topologies on the rotor, namely surface mounted, inset, and interior. of the three topologies, the interior type provides easy control of field attenuation, highest mechanical durability, lowest eddy current loss but higher manufacturing costs. in contrast, surface-mounted permanent magnet structures are less expensive but have low mechanical resistance and high eddy current loss. between the two types is the inset permanent magnet rotor with higher mechanical resistance and lower eddy current loss than the surface-mounted type but lower manufacturing costs compared to interior permanent magnet structures [12][13]. the most applied type as a traction motor for electric vehicles is the interior pmm [14]. the many choices of permanent magnet configurations on the rotor make it challenging to study, especially its effect on machine performance. a study conducted by [15] developed an analytical method for the magnetic vector potential applied to mmp 150 w with surface mounted and inset rotor types, respectively, then compared their magnetic characteristics and cogging torques. meanwhile, [16] studied surface-mounted permanent magnet types using an inner and outer rotor, each varied with segment and non-segment magnetic poles. the characteristics observed include the output torque and core loss. this paper will analyze the pmm characteristics using interior and inset rotor structures. the proposed rotor construction of the inset pmm is intended for widening the field weakening zone. the motors are designed with a base speed of 1000 rpm and use defined stator construction. the study aims to learn the effect of the rotor topology on motor performance include magnetic characteristics, torque-speed characteristics, and cogging torque. the simulations will be conducted analytically and numerically by employing femm 4.2 software. ii. materials and methods a. motor construction the interior and inset pmms in figure 1 have identical dimensions and slightly different rotor construction. in the interior pmm, the permanent magnets are thoroughly buried in the rotor body to prevent it from coming off due to centrifugal force when the motor rotates (figure 1a). besides, magnets do not fatigue quickly so that the operating life of the machine can be longer. in the inset pmm, the upper sides of the permanent magnets are exposed to the air gap. it appears that they are inside the rotor slots with their surfaces are held in place by the flanking top teeth to get a better mechanical strength against the centrifugal force (figure 1b). detailed dimensions of the stator and rotor are shown in figure 2 and table 1. the stator and rotor use grade m-19 of silicon steel lamination with a maximum magnetic flux density of 2.3 t. while the permanent magnet is of ndfeb type grade 35h with a remanent flux density br of 1.17 t. aside from using the same material and stator construction, several constraints are set to achieve a fair comparison, namely: − base frequency, base speed, and current density are 50 hz, 1000 rpm, and 3 a/mm2 consecutively, − stator fill factor < 4 (as close as possible), − phase terminal voltage < 144 v (as close as possible). furthermore, the design stages are carried out in the order depicted in figure 3. b. parameter calculations under the no-load condition, magnetic flux per pole generated by the permanent magnet in the rotor φm is [17]: φ𝑀 = 𝐵𝑚𝑚𝐷𝑖𝐿𝑖 𝑝 (wb) (1) where di = 2 × ri = inner stator diameter (m), bmg is maximum air gap flux density (t), p is number of pole pairs = 3 pairs. furthermore, the maximum linkage flux per phase ψm owing to the permanent magnet is expressed by: ψ𝑀 = 𝑘𝑤𝑁𝑝ℎφ𝑀 (wb) (2) where kw is the winding factor, nph is the phase winding numbers. from (2), the induced voltage per phase eph can be written as (a) (b) figure 1. pmm topology with. (a) interior permanent magnet rotor; (b) inset permanent magnet rotor p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 3 𝐸ph = 1 √2 ωψ𝑀 (v) (3) where ω = 2πf, and f is nominal frequency = 50 hz. the phase leakage reactance x1 is obtained from: 𝑋1 = 4𝜋𝜇0 𝑁ph 2 𝐿i 𝑝𝑝 �𝜆1𝑠 + 𝑙1e 𝐿i 𝜆1e + 𝜆1d + 𝜆1t� (ω) (4) where q is the number of slots per pole per phase, µ0 is the magnetic permeability of vacuum = 0.4π × 10-6 h/m, λ1s is the slot leakage permeance, λ1e is the end winding leakage permeance, l1e is the length of end winding, λ1d is the differential leakage permeance, λ1t is the tooth-top leakage permeance. the mutual reactances of the dand q-axis are given by (5) and (6) [18]: 𝑋ad = 4𝑚𝜇0𝑓 �𝑁ph𝑘𝑤� 2 𝜋𝑝 𝜏𝐿i 𝑔′ 𝑘fd (ω) (5) 𝑋aq = 4𝑚𝜇0𝑓 �𝑁ph𝑘𝑤� 2 𝜋𝑝 𝜏𝐿i 𝑔𝑞 ′ 𝑘fq (ω) (6) table 1. pmm dimensions description, notation value (m) description, notation value (m) stator outer radius, ro 0.0830 upper slot width, ws1 0.0091 stator inner radius, ri 0.0480 lower slot width, ws2 0.0142 effective length of stator core, li 0.2500 stator yoke width, ys 0.0150 stator teeth width, wts 0.0080 rotor radius, rr 0.0470 upper top teeth height, hos 0.0015 surface magnet radius, rmo 0.0433 lower top teeth height, hw 0.0020 permanent magnet height, hm 0.0050 stator slot width, wos 0.0030 shaft radius, rsh 0.0210 stator slot depth, hs 0.0166 (a) (b) figure 2. detailed dimension of the (a) stator; (b) rotor represented by the inset pmm figure 3. the design flowchart p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 4 with τ is the pole pitch (m), g’, 𝑔𝑝′ are dand q-axis of the equivalent air gap (m), kfd, kfq are the form factors of the dand q-axis armature reaction. the dand q-axis synchronous reactances are calculated with (7) and (8), respectively: 𝑋sd = 𝑋1 + 𝑋ad (ω) (7) 𝑋sq = 𝑋1 + 𝑋aq (ω) (8) the phase terminal voltage v is 𝑉 = ��𝐸ph + 𝐼a𝑅a� 2 + (𝐼a𝑋sd)2 + �𝐼a𝑋sq� 2 (v) (9) where ia is the phase armature current (a), and ra is the phase armature resistance (ω). c. torque-speed characteristics figure 4 shows a sine wave pmm operation, where from 0 to nb, the motor develops maximum torque with the maximum armature current ia supplied by the converter, oriented along the q-axis. furthermore, from nb to nmax, the armature current partially demagnetizes the permanent magnet, which is called field weakening operation (figure 4a). in this state, the voltage v is kept constant by utilizing the d-axis demagnetization armature reaction in a negative direction (figure 4b), and the torque decreases until it reaches zero [2]. the correlation between the armature current ia with the dand q-axis currents id and iq are expressed by [19]: 𝐼𝑑 = −𝐼𝑎 sin 𝛾 (a) (10) 𝐼𝑝 = 𝐼𝑎 cos 𝛾 (a) (11) the current vector angle γ correlates proportionally to the motor speed. if the current id increases in the negative direction, the current iq decreases. the d-axis flux linkage reaches a minimum value when id equals nominal current, and iq becomes zero. torque and power are zero, and maximum speed results in nmax [20]. the current angle γ is obtained from: 𝛾 = sin−1 � 𝑘𝑥2 𝑒𝑚2 +𝑘𝑥2 �𝐿 𝑒𝑚� � 2 −1 2 𝑘𝑥 2 𝐿 � (12) with 𝑒𝑚 = 𝐸𝑜 𝑉𝑡 (13) 𝑘 = 1 𝑒𝑚�1−𝑒𝑚 2 = 𝑛𝑚𝑚𝑥 𝑛𝑛𝑜𝑚 (14) 𝐿 = 𝑒𝑚�1 − 𝑒𝑚2 (15) where em is a ratio of per-unit open-circuit voltage e0 to maximum r.m.s a.c converter voltage vt as the base voltage (pu), the maximum kx = k and the maximum γ = 90º, nmax is the maximum speed (rpm), and nnom is the nominal speed = 6000 rpm. the output torque is 𝑇 = 3𝑝 𝜔 �𝐸q𝐼q + (𝑋sd − 𝑋sq)𝐼d𝐼q� (nm) (16) where: eq = eph the first term is permanent magnet torque, related to the linkage flux that generates the induced voltage eq, while the second term is the reluctance torque affected by inductance/reactance and currents on the d and q axes [21]. d. cogging torque cogging torque arises due to the interaction between the rotor magnetic flux and the reluctance in the air gap, whose value varies owing to the stator slot geometry. the cogging torque tc is expressed by equation [22]: 𝑇c = − 1 2 ϕ𝑔2 𝑑ℛ 𝑑θ (nm) (17) where φg is magnetic flux (wb), ℛ is air gap reluctance (a.t/wb), and θ is rotor position (mechanical degree). cogging torque occurs at no-load conditions. therefore, the magnetic flux in the air gap is entirely generated by rotor poles. the change of reluctance occurs periodically, so does the cogging torque. the magnetic strength used is proportional to the produced cogging torque. in this study, cogging torque is obtained through numerical simulation. iii. results and discussions the results of calculations and simulations of motor performance comprise magnetic characteristics, torque-speed characteristics, as well as cogging torque, which will be described in detail in the following subsections. a. magnetic characteristics figure 5 show the magnetic distributions of the interior and inset pmms, respectively, where the (a) (b) figure 4. a sine wave pmm operation. (a) torque-speed characteristic; (b) demagnetization phasor diagram d-axis current id p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 5 most magnetic flux crossing the air gap towards the stator teeth comes from the middle part of the permanent magnet surface. the magnetic flux then flows to the stator yoke and divides into two directions, each interacting with the opposing pole next to it by forming a closed loop. on the other hand, it seems that part of the magnetic flux from both sides of the adjoining magnet tends to flow through the rotor body, having higher magnetic permeability (µr = 4000) than air (µr = 1), to interact with the adjacent poles. it causes a flux leakage indicated by the high flux concentration around the magnet edges. in the interior pmm (figure 5a), the density of the leakage flux is higher (2.037 t) than that in the inset pmm (figure 5b), which is 1.931 t. figure 6 show the waveform of air-gap flux density of interior and inset pm motors, respectively. it seems that the interior pmm produces a more distorted sinusoidal waveform due to the high leakage flux (figure 6a). however, the average flux density is higher at 0.471 t, compared to the inset pmm, which is only 0.363 t; due to the high magnetic permeability of the rotor body that makes it can carry more magnetic flux to cross the air gap. the waveform of the air gap magnetic flux density of the inset pmm is smoother approaching the sinusoidal waveform (figure 6b). the waveform distortion is caused by leakage flux that occurs in the parts of the permanent magnet, which are enclosed by the top teeth of the rotor slots. leakage flux increases eddy current, thus decreases machine efficiency [23]. b. torque-speed characteristics the calculation results of the motor parameters on base speed are listed in table 2. the motor characteristics, namely the torque-current phase angle and torque-speed curves, are obtained using (10) (16). the value of vt in (13) is varied by changing the current density. the simulation results are shown in figure 7 for the inset pmm and figure 8 for the interior pmms. torque as a function of current phase angle in the field weakening region shown in figure 7a and figure 8a corresponds with torque-speed curves shown in figure 7b and figure 8b, respectively. the two motors' characteristics are similar in that the smaller the armature current, the smaller the current phase angle that cannot achieve the maximum speed. it is because the flux generated by the armature current is not adequate to weaken all the ones produced by the permanent magnet to increase the speed at a given voltage limit [2]. the curve with a dashed line is obtained using the base parameters in table 2. it demonstrates that the inset pmm with a lower ψm produces a higher rotation, approximately 4200 rpm, whereas the interior pmm produces 3162 rpm. meanwhile, the (a) (b) figure 5. magnetic flux distribution in no-load condition. (a) interior pm motor; (b) inset pm motor p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 6 table 2. motor parameters on base speed parameter interior pm motor inset pm motor unit phase terminal voltage, v 149.93 158.03 v phase induction voltage, eph 133.85 128.86 v phase armature current, ia 14.73 12.46 a magnetic flux, ψm 0.6025 0.5801 wb number of turns per phase nph 96 120 turns armature resistance, ra 0.27 0.4 ω d-axis inductance, ld 0.010 0.014 h q-axis inductance, lq 0.014 0.016 h rotor saliency ratio, lq/ld 1.4 1.15 output torque of the interior pmm, on the other hand, is 56.47 nm greater than that of the inset pmm (46.01 nm). when the current increases beyond its base value, the torque and speed will also increase until they reach their maximum value. maximum torque and speed, however, are not achieved at the same time. when the motor achieves maximum torque, its rotation slows slightly due to voltage saturation [2]. the inset pmm has a maximum rotation of 6259 rpm but drops to 6212 rpm when it reaches a maximum torque of 66.41 nm. meanwhile, the highest speed of the interior pmm is 6310 rpm, down to 6220 rpm when it attains a maximum torque of 92.87 nm. the maximum terminal voltage occurs when the motor reaches the maximum torque. it is 189.27 v for the interior pmm and 182.03 v for the pmm inset, respectively. the interior pmm can produce higher torque and a wider speed range due to the higher saliency ratio [24]. high output torque is needed by the vehicle to start moving from rest and to climbing, while a wide speed range provides comfort when cruising or driving, such as on the highway. c. cogging torque the characteristic of cogging torque of both pmms is exhibited in figure 9. cogging torque is greatly influenced by the magnitude of the magnetic flux in the air gap. therefore, with higher ψm, interior pmm produces higher tc (2.90 nm) than the inset one (1.93 nm). (a) (b) figure 6. air gap magnetic flux density waveform at no-load condition. (a) interior pmm; (b) inset pmm 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 5 10 15 20 25 30 35 bg 0 (t ) tangential length of the air gap (mm) -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0 5 10 15 20 25 30 35 bg 0 (t ) tangential length of the air gap (mm) p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 7 (a) (b) figure 7. inset pmm characteristics. (a) torque current phase angle curve; (b) torque-speed curve (a) (b) figure 8. interior pmm characteristics. (a) torque current phase angle curve; (b) torque-speed curve 0 15 30 45 60 75 90 105 0 10 20 30 40 50 60 70 80 90 t (n m ) current phase angle (deg.) ia = 24.20 a ia = 22.09 a ia = 19.63 a ia = 14.73 a ia = 13.50 a 0 15 30 45 60 75 0 1000 2000 3000 4000 5000 6000 7000 t (n m ) n (rpm) ia = 17.87 a ia = 16.62 a ia = 14.54 a ia = 12.46 a ia = 11.43 a 0 15 30 45 60 75 0 10 20 30 40 50 60 70 80 90 t (n m ) current phase angle (deg.) ia = 17.87 a ia = 16.62 a ia = 14.54 a ia = 12.46 a ia = 11.43 a 0 15 30 45 60 75 90 105 0 1000 2000 3000 4000 5000 6000 7000 t (n m ) n (rpm) ia = 24.20 a ia = 22.09 a ia = 19.63 a ia = 14.73 a ia = 13.50 a p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 8 the cogging torque waveform of the interior pmm is also smoother owing to the uniform air gap radial length. an uneven air gap increases the torque ripple [25], which can reduce bearing life, whereas a higher cogging torque requires a higher starting current to start rotating the motor. cogging torque can be reduced by optimizing parameters, such as the pole arc to pole pitch ratio, stator slot opening width, etc. iv. conclusion this paper has discussed the comparison of interior and inset pmm characteristics for electric vehicle applications. the calculation and simulation results show that at the base speed, the interior pmm is superior in generating output torque (56.47 nm) but with a lower rotation (3162 rpm), while the pmm inset produces lower torque (46.01 nm) but higher rotation (4200 rpm). a higher saliency ratio makes the interior pmm produces higher maximum torque and speed at both constant torque and field weakening regions than the pmm inset, which is 92.87 nm and 6310 rpm, respectively. regarding the cogging torque, the interior pmm generates a little higher (2.90 nm) than the inset pmm (1.93 nm). from these results, it can be concluded that, in general, the interior pmm demonstrates better performance in all studied zones and is preferable for electric vehicle applications. however, design optimization needs to be done, specifically reducing the cogging torque. acknowledgment the authors would like to thank research center for electrical power and mechatronics, indonesian institute of sciences for all the provided facilities. declarations author contribution p. irasari contributed as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] b. qu, q. yang, y. li, m. a. sotelo, s. ma, and z. li, "a novel surface inset permanent magnet synchronous motor for electric vehicles," symmetry, vol. 12, pp. 1-14, 2020. [2] t. a. huynh and m.-f. hsieh, "performance analysis of permanent magnet motors for electric vehicles (ev) traction considering driving cycles " energies, vol. 11, pp. 1-24, 2018. [3] l. petkovska and g. cvetkovski, "assessment of torques for a permanent magnet brushless dc motor using fea," przegląd elektrotechniczny (electrical review), vol. 87, pp. 132-136, 2011. [4] f. erken, e. öksüztepe, and h. kürüm, "online adaptive decision fusion based torque ripple reduction in permanent magnet synchronous motor," iet electric power applications, vol. 10, pp. 189– 196, 2016. [5] z. s. du and t. a. lipo, "reducing torque ripple using axial pole shaping in interior permanent magnet machines," ieee transactions on industry applications, vol. 56, pp. 148-157, 2020. [6] t. f. janecek, j. m. dyer, and k. williams, "cogging torque reduction device for electrical machines," us patent us9006951b2, 2015. [7] g. j. li, b. ren, z. q. zhu, y. x. li, and j. ma, "cogging torque mitigation of modular permanent magnet machines," ieee transaction on magnetics, vol. x, pp. 1-10, 2015. [8] j. r. b. a. monteiro, a. a. o. jr, m. l. aguiar, and e. r. sanagiotti, "electromagnetic torque ripple and copper losses reduction in permanent magnet synchronous machines," european transactions on electrical power, vol. 22, pp. 627-644, 2011. [9] g. g.-lopez, m. perisic, and s. hiti, "gain adjustment to improve torque linearity in a field weakening region," us patent us 8,228,016 b2, 2012. figure 9. cogging torque characteristics -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 0 5 10 15 20 25 30 35 40 45t c (n m ) rotor position (mech. degree) interior pmm inset pmm https://mev.lipi.go.id/ https://www.mdpi.com/2073-8994/12/1/179 https://www.mdpi.com/2073-8994/12/1/179 https://www.mdpi.com/2073-8994/12/1/179 https://www.mdpi.com/2073-8994/12/1/179 https://www.mdpi.com/1996-1073/11/6/1385 https://www.mdpi.com/1996-1073/11/6/1385 https://www.mdpi.com/1996-1073/11/6/1385 https://www.mdpi.com/1996-1073/11/6/1385 http://pe.org.pl/articles/2011/12b/37.pdf http://pe.org.pl/articles/2011/12b/37.pdf http://pe.org.pl/articles/2011/12b/37.pdf http://pe.org.pl/articles/2011/12b/37.pdf https://doi.org/10.1049/iet-epa.2015.0258 https://doi.org/10.1049/iet-epa.2015.0258 https://doi.org/10.1049/iet-epa.2015.0258 https://doi.org/10.1049/iet-epa.2015.0258 https://ieeexplore.ieee.org/document/8862931 https://ieeexplore.ieee.org/document/8862931 https://ieeexplore.ieee.org/document/8862931 https://ieeexplore.ieee.org/document/8862931 https://patents.google.com/patent/us9006951 https://patents.google.com/patent/us9006951 https://patents.google.com/patent/us9006951 https://patents.google.com/patent/us9006951 https://ieeexplore.ieee.org/document/7247735 https://ieeexplore.ieee.org/document/7247735 https://ieeexplore.ieee.org/document/7247735 https://ieeexplore.ieee.org/document/7247735 https://doi.org/10.1002/etep.594 https://doi.org/10.1002/etep.594 https://doi.org/10.1002/etep.594 https://doi.org/10.1002/etep.594 https://pdfpiw.uspto.gov/.piw?pagenum=0&docid=08228016&idkey=&homeurl=%2f https://pdfpiw.uspto.gov/.piw?pagenum=0&docid=08228016&idkey=&homeurl=%2f https://pdfpiw.uspto.gov/.piw?pagenum=0&docid=08228016&idkey=&homeurl=%2f p. irasari et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 1-9 9 [10] m. t. elsayed, o. a. mahgoub, and s. a. zaid, "simulation study of a new approach for field weakening control of pmsm," journal of power electronics, vol. 12, pp. 136-144, 2012. [11] f. ma, h. yin, l. wei, g. tian, and h. gao, "design and optimization of ipm motor considering flux weakening capability and vibration for electric vehicle applications," sustainability, vol. 10, pp. 1-15, 2018. [12] a. rahideh, h. m.-jahromi, m. mardaneh, f. dubas, and t. korakianitis, "analytical calculations of electromagnetic quantities for slotted brushless machines with surface-inset magnets," progress in electromagnetics research b, vol. 72, pp. 49– 65, 2017. [13] w. zhao, t. a. lipo, and b.-i. kwon, "optimal design of a novel asymmetrical rotor structure to obtain torque and efficiency improvement in surface inset pm motors," ieee transactions on magnetics vol. 51, 2015. [14] d. matsuhashi, k. matsuo, t. okitsu, t. ashikaga, and t. mizuno, "comparison study of various motors for evs and the potentiality of a ferrite magnet motor," ieej journal of industry applications, vol. 4, pp. 174-179, 2015. [15] a. jabbari, "2d analytical modeling of magnetic vector potential in surface mounted and surface inset permanent magnet machines," iranian journal of electrical & electronic engineering, vol. 13, pp. 362-373, 2017. [16] m. ali, m. hejra, and t. hafedh, "on the performances investigation of different surface mounted permanent magnet machines," international journal of power electronics and drive system, vol. 6, pp. 509-515, 2015. [17] h. chengyuan, "design of high efficiency brushless permanent magnet machines and driver system," doctoral thesis, electrical and computer engineering, university of central florida, orlando, florida, 2018. [18] k. wirtayasa, p. irasari, m. kasim, p. widiyanto, and m. f. hikmawan, "load characteristic analysis of a double-side internal coreless stator axial flux pmg," journal of mechatronics, electrical power, and vehicular technology, vol. 10, pp. 17– 23, 2019. [19] m. r. khowja, g. vakil, and c. gerada, "analytical tool to generate torque-speed characteristics for surface mounted pm machines in constant torque and field weakening regions," in iecon 2019 45th annual conference of the ieee industrial electronics society, lisbon, portugal, 2019, pp. 922927. 6 [20] b. m. wilamowski and j. d. irwin, power electronics and motor drives, second ed. boca raton, fl: crc press, 2011. [21] x. zhang, j. ji, j. zheng, and x. zhu, "improvement of reluctance torque in fault-tolerant permanent-magnet machines with fractional-slot concentrated-windings," ieee transactions on applied superconductivity, vol. 28, 2018. [22] m. g.-gracia, á. j. romero, j. h. ciudad, and s. m. arroyo, "cogging torque reduction based on a new pre-slot technique for a smallwind generator," energies, vol. 11, pp. 115, 2018. [23] m. satoa, m. nireib, y. yamanakaa, t. suzukia, y. bua, and t. mizunoa, "increasing the efficiency of a drone motor by arranging magnetic sheets to windings," energy reports vol. 6, pp. 439– 446, 2020. [24] z. zhang, c. xia, h. wang, and t. shi, "analytical field calculation and analysis of surface inset permanent magnet machines with high saliency ratio," ieee transactions on magnetics, vol. 52, 2016. [25] j. liang, a. parsapour, z. yang, c. c.-narvaez, m. moallem, and b. fahimi, "optimization of air-gap profile in interior permanent-magnet synchronous motors for torque ripple mitigation," ieee transactions on transportation electrification, vol. 5, pp. 118-125, 2019. http://dx.doi.org/10.6113/jpe.2012.12.1.136 http://dx.doi.org/10.6113/jpe.2012.12.1.136 http://dx.doi.org/10.6113/jpe.2012.12.1.136 http://dx.doi.org/10.6113/jpe.2012.12.1.136 https://doi.org/10.3390/su10051533 https://doi.org/10.3390/su10051533 https://doi.org/10.3390/su10051533 https://doi.org/10.3390/su10051533 http://www.jpier.org/pierb/pier.php?paper=16091502 http://www.jpier.org/pierb/pier.php?paper=16091502 http://www.jpier.org/pierb/pier.php?paper=16091502 http://www.jpier.org/pierb/pier.php?paper=16091502 http://www.jpier.org/pierb/pier.php?paper=16091502 http://www.jpier.org/pierb/pier.php?paper=16091502 https://ieeexplore.ieee.org/document/7093504 https://ieeexplore.ieee.org/document/7093504 https://ieeexplore.ieee.org/document/7093504 https://ieeexplore.ieee.org/document/7093504 https://doi.org/10.1541/ieejjia.4.174 https://doi.org/10.1541/ieejjia.4.174 https://doi.org/10.1541/ieejjia.4.174 https://doi.org/10.1541/ieejjia.4.174 http://journals.medilam.ac.ir/files/site1/rds_journals/446/article-446-502082.pdf http://journals.medilam.ac.ir/files/site1/rds_journals/446/article-446-502082.pdf http://journals.medilam.ac.ir/files/site1/rds_journals/446/article-446-502082.pdf http://journals.medilam.ac.ir/files/site1/rds_journals/446/article-446-502082.pdf http://doi.org/10.11591/ijpeds.v6.i3.pp509-515 http://doi.org/10.11591/ijpeds.v6.i3.pp509-515 http://doi.org/10.11591/ijpeds.v6.i3.pp509-515 http://doi.org/10.11591/ijpeds.v6.i3.pp509-515 https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=7238&context=etd https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=7238&context=etd https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=7238&context=etd https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=7238&context=etd https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://dx.doi.org/10.14203/j.mev.2019.v10.17-23 https://ieeexplore.ieee.org/document/8927436 https://ieeexplore.ieee.org/document/8927436 https://ieeexplore.ieee.org/document/8927436 https://ieeexplore.ieee.org/document/8927436 https://ieeexplore.ieee.org/document/8927436 https://ieeexplore.ieee.org/document/8927436 https://jntukucen.ac.in/ebook_files/7.pdf https://jntukucen.ac.in/ebook_files/7.pdf https://ieeexplore.ieee.org/document/8295229 https://ieeexplore.ieee.org/document/8295229 https://ieeexplore.ieee.org/document/8295229 https://ieeexplore.ieee.org/document/8295229 https://doi.org/10.3390/en11113219 https://doi.org/10.3390/en11113219 https://doi.org/10.3390/en11113219 https://doi.org/10.3390/en11113219 https://doi.org/10.1016/j.egyr.2019.11.100 https://doi.org/10.1016/j.egyr.2019.11.100 https://doi.org/10.1016/j.egyr.2019.11.100 https://doi.org/10.1016/j.egyr.2019.11.100 https://ieeexplore.ieee.org/document/7539636 https://ieeexplore.ieee.org/document/7539636 https://ieeexplore.ieee.org/document/7539636 https://ieeexplore.ieee.org/document/7539636 https://ieeexplore.ieee.org/document/8620373 https://ieeexplore.ieee.org/document/8620373 https://ieeexplore.ieee.org/document/8620373 https://ieeexplore.ieee.org/document/8620373 https://ieeexplore.ieee.org/document/8620373 introduction ii. materials and methods a. motor construction b. parameter calculations c. torque-speed characteristics d. cogging torque iii. results and discussions a. magnetic characteristics b. torque-speed characteristics c. cogging torque iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.18-27 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. local positioning system for autonomous vertical take-off and landing using ultra-wide band measurement ranging system niam tamami *, bambang sumantri, prima kristalina electrical engineering department, politeknik elektronika negeri surabaya jl raya its – kampus pens, surabaya, 60111, indonesia received 27 november 2020; accepted 20 may 2021; published online 31 july 2021 abstract an autonomous vertical take-off and landing (vtol) must be supported with an accurate positioning system, especially for autonomous take-off, landing, and other tasks in small area. this paper presents a novel method of small local outdoor positioning system for localizing the area of dropping and landing of autonomous vtol by utilizing the low-cost precision ultra-wide band (uwb) ranging system. we compared symmetrical single sided-two way ranging (sss-twr), symmetrical double sided-two way ranging (sds-twr), and asymmetrical double sided-two way ranging (ads-twr) methods to get precision ranging measurement on uwb radio module. ads-twr was superior to others by resulting in minimum distance error. the ads-twr average error was 1.38 % (35.88 cm), sds-twr average error was 1.83 % (47.58 cm), and sss-twr average error was 2.73 % (70.98 cm). furthermore, the trilateration method was utilized to obtain the local position of the autonomous vtol. the trilateration method successfully implemented autonomous vtol quadcopter positioning in a small local outdoor area (20 m x 30 m). autonomous vtol has been able to drop seven payloads in seven areas (2 m x 2 m) and landed in the home position (3 m x 3 m) successfully. ©2021 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: autonomous vtol; uwb local positioning system; trilateration. i. introduction the development of autonomous vtol vehicle increases over this decade. this vehicle has many advantages over the other types because it is able to carry a heavy payload, easy to control, more stable, and has vertical take-off and landing ability. therefore, this vehicle is widely used to facilitate human tasks. some examples of using this vehicle are environmental mapping, human surveillance, and packet delivery. positioning ability is one most important capability in an autonomous vtol system. the positioning system must be accurate to support take-off, hover, and landing in a safe area. commonly, autonomous vtol uses global positioning system (gps) as a satellite-based positioning system. usually, a gps chip only has ±3 m maximum accuracy based on the received signal from satellites. autonomous vtol is complicated to take-off, hover or land in a narrower area. therefore, autonomous vtol requires accurate positioning. for example, environmental mapping autonomous vtol requires precise positioning to avoid plotting mistake on the map. another example is packet delivery autonomous vtol. it requires accurate positioning to send the package to a specific home address and to drop it in the right and safe place, not in a random place in a home radius location. there were some researches about uwb range measurement. akahori et al. designed an indoor position estimation system with uwb, inertial measurement unit (imu) and a distance sensor for quadcopter [1]. this system consisted of one tag and three anchor uwb modules. quadcopter coordinates were calculated by the pythagorean and extended kalman filter equations. the maximum error for x, y coordinates were 0.2 m. mai et al. developed an indoor local positioning estimator for unmanned blimp [2]. this system used uwb and gyroscope because gps and magnetometer cannot work for indoor positioning. this system used a kalman filter to estimate the state of the blimp. experimental * corresponding author. tel: +62-812-1796-6299 e-mail address: niam@pens.ac.id https://dx.doi.org/10.14203/j.mev.2021.v12.18-27 https://dx.doi.org/10.14203/j.mev.2021.v12.18-27 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.18-27 https://dx.doi.org/10.14203/j.mev.2021.v12.18-27 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.18-27&domain=pdf n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 19 results showed that the error estimator was less than 1 m and orientation error was less than 11 degrees. ledergerber et al. developed a method for calibrating away inaccuracies in ultra-wideband range measurements using a maximum likelihood approach to minimize data error due to unideal antenna and environmental influence [3]. the research only used two uwb radio and tested in simulation by considering the only parameter of the uwb radio model without including the environmental condition. guosheng et al. used extended kalman filter and unscented kalman filter to improve uwb system accuracy [4]. this system was used for mobile robot positioning. the experiments were carried out under non-line-ofsight (nlos) and line-of-sight (los) conditions. experiment result has shown that unscented kalman filter has a smaller average error than extended kalman filter. feng et al. combined uwb and imu to make an indoor navigation system [5]. they compared extended kalman filter with least square and unscented kalman filter with direct positioning algorithm to get the best-improved accuracy method. experimental results showed that extended kalman filter was better than least square, and unscented kalman filter was better than direct positioning algorithm. ren et al. developed a cow monitoring activity system using uwb and video processing [6]. they used seven uwb anchor and a uwb tag installed on a cow. the cow position was calculated using least square estimation (lse) based uwb ranging data. this system has accuracy with mean error of 0.39 m and standard deviation of 0.62 m. several other kinds of research were bluetooth, xbee, and radio frequency identification (rfid) localization system. however, these researches were only able to be used in areas under 10 m x 10 m. ramadhani et al. developed an indoor localization system utilizing bluetooth low energy (ble) [7]. they compared trilateration, trilateration-geometric dilution of precision (gdop), multilateration, and multilateration-gdop to localize the area. multilateration-gdop was superior to others. giuliano et al. developed bluetooth low energy localization system [8]. feed-forward neural network combined by non-linear least square algorithm was used to calculate position estimation with 1 m accuracy. pusnik et al. developed bluetooth low energy localization system [9]. this system detected the closest transmitter based on the data from previous measurements. cheng et al. developed a book localization system in a bookshelf based rfid rssi [10]. the distance between tag and anchor (antenna) was 38.5 cm. they used the deep learning method to estimate book position, and the average error is 10.02 cm. ainul et al. developed an indoor mobile cooperative tracking system [11]. they used xbee s2 pro module to get received signal strength indication (rssi) data and to calculate the position by trilateration method. they also implemented extended gradient filter, extended kalman filter and modified extended kalman filter to improve localizing accuracy. modified extended kalman filter improved 41.28 % of accuracy. another technology used the wifi localization system. the researches used rssi to estimate distance. however, the rssi data are not linear, depending on environmental conditions. zhang et al. developed a hierarchical classification-based method to estimate position based wifi received signal strength data [12]. this method offers 10 % to 22 % reduced average position error compared to several benchmark methods. ashraf et al. used a deep neural network ensemble classifier method to estimate position using wifi rssi [13]. this method showed mean error of 2.84 m with standard deviation of 2.24 m. monica et al. developed a localization algorithm based on nonlinear programming [14]. this method was compared by particle swarm optimization and two-stage maximum likelihood. this method gave a guaranteed globally optimal solution of position estimation. ssekidde et al. compared convolutional neural network and artificial neural network to identify a room [15]. they used wifi rssi data that were processed by continuous wavelet transforms. the experimental result showed that cnn superiors to ann, with accuracies of 97.3 % and 70.6 % for cnn and ann. li et al. developed smartphone-based indoor localization [16]. they integrated channel state information (csi) and magnetic field strength (mfs) localization methods. the experimental results showed that the mean distance error was less than 0.5 m. koike-akino et al. developed indoor localization using wifi signal to noise ratio [17]. they used deep learning to calculate position. the position root mean square error is 28.7 cm in 250 cm x 350 cm area. peng et al. developed an improved knearest neighbor algorithm for indoor localization [18]. compared with the knn, e-wknn, and pwknn algorithms, the positioning accuracy of this method was improved by 29.4 %, 23.5 %, and 20.7 %, respectively. maghdid et al. developed an indoor localization simulation. they used long shortterm memory recurrent neural network to estimate position based wifi rssi [19]. they improved the performance of long short-term memory recurrent neural network by adding a transfer learning algorithm to wifi rssi data. this simulation result confirmed that this method could obtain 1.5 m to 2 m positioning accuracy. sadowski et al. compared knn and naive bayes to calculate a tag position in a room [20]. the experiment showed that knn is superior to naive bayes. there were other researches about localization. ranade et al. developed quadcopter obstacle avoidance and path planning simulation using the flood fill method [21]. this method was compared with the potential field method to show the fastest execution method. the result has been demonstrated that flood fills faster than the potential field method. honig et al. developed quadcopter swarm trajectory planning for an indoor area using vicon camera positioning [22]. shen et al. developed a cooperative relative navigation method that exploited ranging sensor to assist the global navigation satellite system (gnss) [23]. this method improved navigation accuracy and robustness. gu et al. developed landmark graph-based indoor n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 20 localization [24]. they used multisensory data on a smartphone (accelerometer, gyroscope, magnetometer, barometer, wifi, light sensor) then extracted the feature to make a landmark on a building. this method has 0.8 m mean error. ashraf et al. developed an indoor localization system using a convolutional neural network-based magnetic field pattern [25]. this system offered 1.01 m accuracy. this paper presents a novel method of small local outdoor positioning system for localizing the area for dropping and landing of an autonomous vtol, based on low-cost precision ultra-wide band measurement ranging system. ii. materials and methods we started by designing ranging hardware. a set of uwb radio module was used to make small local positioning area for autonomous vtol dropping or landing area. when autonomous vtol did not detect uwb signal, gps system was used. autonomous vtol went to small local positioning area using gps coordinate and then detected uwb signal. when it was detected, local positioning process was started. autonomous vtol could drop or land in small local positioning area precisely. figure 1 shows a small local outdoor positioning area of autonomous vtol. the area size is 20.00 m x 30.00 m. this system consists of autonomous vtol and uwb tag (moveable position), and uwb anchor (fix position). uwb anchor 1 is located at (11.00, 0.00) m, uwb anchor 2 is located at (0, 15.00) m and uwb anchor 3 is located at (11.00, 30.00) m. autonomous vtol can localize its position in this small local positioning area. home area is 3 m x 3 m to take-off and landing operation, dropping area (yellow square) is 2 m x 2 m to drop user payloads. home location position (red square) is (1.50, 1.50) m, and dropping positions (yellow square) are (8.50, 11.00), (1.00, 15.00), (4.00, 22.5), (1.00, 28.00), (18.50, 26.00), (12.50, 20.00), (17.00, 7.50) m. a. software tag and anchor hardware design this section presents about schematic design of uwb tag and anchor transceiver for ranging sensor. figure 2 shows the schematic of uwb tag and anchor transceiver. we use dwm1000 as uwb ic chip and arduino pro mini as main controller. arduino gets ranging data from dwm1000 using spi communication. spiclk, spimiso, spimosi, spics of uwb is connected respectively on d13, d12, d11, d10 arduino pin. the system needs 3.3v so we add 3.3v voltage regulator ic. we also add led power indicator. figure 3 shows the hardware board for the tag and anchor transceiver from figure 2 schematic. the green board is dwm1000, and the blue board is arduino minimum system. this hardware board was duplicated into four pieces. one-piece as uwb tag, the other as uwb anchor 1, uwb anchor 2, uwb anchor 3. figure 1. a small local outdoor positioning area of autonomous vtol figure 2. uwb tag and anchor schematic n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 21 b. uwb ranging algorithm figure 4 shows the ranging algorithm to measure distance between uwb tag and anchor. measuring cycle is started when uwb tag transmit poll message to idle uwb anchor. uwb anchor checks the message address. if the message address belongs to uwb anchor, uwb anchor transmits range message to uwb tag. uwb tag receives range message and checks the message address. if the message address belongs to uwb tag, uwb tag calculates the range. uwb has several modes of range measurements algorithm. there are symmetrical single sided-two way ranging (sss-twr), symmetrical double sidedtwo way ranging (sds-twr) and asymmetrical double sided-two way ranging (ads-twr). we can choose the best algorithm with minimal error sss − twr 𝑇𝑝𝑝𝑝𝑝 = 𝑇𝑝𝑝𝑇𝑇𝑇−𝑇𝑝𝑇𝑝𝑇𝑇 2 (1) figure 5 shows the sss-twr algorithm. in the sss-twr algorithm, uwb device a transmits a message to uwb device b. then, uwb device b receives the message and transmits the answer to uwb device a. the time between the received message process and the transmitted answer process of uwb device b is treply. the time between the transmitted message process and the received answer process of uwb device a is tround. tprop is propagation ranging time. tprop can be calculated by (1). 𝑆𝑆𝑆 − 𝑇𝑇𝑇 𝑇𝑝𝑝𝑝𝑝 = 𝑇𝑝𝑝𝑇𝑇𝑇1−𝑇𝑝𝑇𝑝𝑇𝑇1+𝑇𝑝𝑝𝑇𝑇𝑇2−𝑇𝑝𝑇𝑝𝑇𝑇2 4 (2) figure 6 shows the illustration of sds-twr algorithm. in the sds-twr algorithm, uwb device a transmits a message to uwb device b. then, uwb device b receives the message and transmits the figure 4. uwb ranging flowchart start transmit (msg=poll) received msg from anchor? is it my address? msg == range? calculate range(m) stop no yes no yes no start idle received msg from tag? is it my address? msg == poll? transmit (msg=range) stop no yes no yes no figure 3. uwb tag and anchor transceiver n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 22 answer to uwb device a. uwb device a receives answer and transmits it back to uwb device b. tround1, tround2, treply1, and treply2 are transmitting and receiving duration of uwb message, respectively. tprop can be calculated by (2). ads-twr illustration is same as sds-twr, but with different equation propagation time. equation (3) shows ads-twr equation. this equation eliminates error when treply1 and treply2 have same value. 𝐴𝑆𝑆 − 𝑇𝑇𝑇 𝑇𝑝𝑝𝑝𝑝 = 𝑇𝑝𝑝𝑇𝑇𝑇1∗𝑇𝑝𝑝𝑇𝑇𝑇2−𝑇𝑝𝑇𝑝𝑇𝑇1∗𝑇𝑝𝑇𝑝𝑇𝑇2 𝑇𝑝𝑝𝑇𝑇𝑇1+𝑇𝑝𝑝𝑇𝑇𝑇2+𝑇𝑝𝑇𝑝𝑇𝑇1+𝑇𝑝𝑇𝑝𝑇𝑇2 (3) the distance between uwb tag and anchor can be calculated by (4) distance (meter) = c ∗ 𝑇𝑝𝑝𝑝𝑝 ∗ t (4) where c is the light velocity (299792458 m/s), tprop is the ranging propagation time of uwb, and t is the uwb resolution timestamp (~15.6 ps). c. autonomous vtol specification this section presents about the autonomous vtol specification. we continuously develop autonomous vtol over three years for research and competition. we choose hexacopter configuration to improve the lift weight ability. figure 7 shows the autonomous vtol. the autonomous vtol used six brushless motors. uwb tag is attached above payload box to receive ranging data from uwb anchor. the payload box can carry seven boxes. each box's maximum dimension and maximum weight are 10 cm x 10 cm x 4 cm and 100 gr—high-level and low-level controller centrally located on the frame. gps is used when autonomous vtol cannot detect uwb signal. figure 8 shows the block diagram of autonomous vtol. the autonomous vtol controller consists of a low-level controller and a high-level controller. the low-level controller uses hex cube pixhawk 2.1 with redundant imu and gps. the main task of a lowlevel controller is flight navigation control system. the high-level controller uses odroid mini pc. the high-level controller main task is additional custom algorithm processing by the user like image and video processing, including local positioning system. 433 radio transmitter is used to communicate with ground control software. autonomous vtol uses a 5000 mah battery to get 10 minutes of flight time. this autonomous vtol has been equipped with uwb tag for local positioning. uwb tag sends ranging data to the high-level controller and calculates autonomous vtol x, y position. the detailed calculation for the x, y position is described in the methodology. d. method this section presents about trilateration method to localize autonomous vtol. this method is used to calculate uwb tag position. figure 9 shows the trilateration model illustration. (x, y) is uwb tag position, and the position is moveable. uwb anchor has fix position. (x1, y1) is uwb anchor 1 position, (x2, y2) is uwb anchor 2 position, and (x3, y3) is uwb figure 5. sss-twr range measurements mode algorithm figure 6. sds-twr range measurements mode algorithm figure 7. the hexacopter autonomous vtol figure 8. autonomous vtol block diagram figure 9. trilateration model n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 23 anchor 3 position. trilateration input is distance data between uwb tag and anchor (r1, r2, r3). a circle with (x,y) coordinate has an equation: x2 + y2 = r2 (5) the trilateration equation for uwb tag at (x, y) and uwb anchor at (x1, y1), (x2, y2), and (x3, y3) are: (x − x1)2 + (y − 𝑦1)2 = r12 (6) (x − x2)2 + (y − y2)2 = r22 (7) (x − x3)2 + (y − y3)2 = r32 (8) x is uwb tag x-axis position, y is uwb tag y-axis position. x1, x2, and x3 are uwb anchor 1, anchor 2, and anchor 3 x-axis fixed position. y1, y2, and y3 are uwb anchor 1, anchor 2, and anchor 3 y-axis fixed position. r1 is distance between uwb tag and anchor 1. r2 is distance between uwb tag and anchor 2. r3 is distance between uwb tag and anchor 3. then, equations (6), (7), and (8) can be further derived to (9), (10), and (11) x2 − 2x1x + x12 + y2 − 2y1y2 + y12 = r12 (9) x2 − 2x2x + x22 + y2 − 2y2y2 + y22 = r22 (10) x2 − 2x3x + x32 + y2 − 2y3y2 + y32 = r32 (11) subtracting (9) by (11): (−2x1 + 2x2)x + (− 2y1 + 2y2)𝑦 = r12 − r32 − x12 + x22 − y12 + y22 (12) then, subtracting (10) by (11): (−2x2 + 2x3)x + (− 2y2 + 2y3)𝑦 = r22 − r32 − x22 + x32 − y22 + y32 (13) lets rewrite (12) using a,b,c values, and (13) using d,e,f values. this would in the following form: ax + by = c (14) dx + ey = f (15) lets rewrite equation (14) and (15) into matrix (16) �𝐴 𝐵 𝑆 𝐸 �� 𝑥 𝑦� = � 𝐶 𝐹 � (16) � 𝑥 𝑦� = � 𝐴 𝐵 𝑆 𝐸 � −1 �𝐶 𝐹 � (17) � 𝑥 𝑦� = 1 𝐴𝐴−𝐵𝐵 � 𝐸 −𝐵 −𝑆 𝐴 ��𝐶 𝐹 � (18) � 𝑥 𝑦� = 1 𝐴𝐴−𝐵𝐵 � 𝐸𝐶 −𝐵𝐹 −𝑆𝐶 𝐴𝐹 � (19) from (19), we can calculate x and y coordinate: 𝑥 = 𝐴𝐸−𝐵𝐵 𝐴𝐴−𝐵𝐵 (20) 𝑦 = 𝐴𝐵−𝐵𝐸 𝐴𝐴−𝐵𝐵 (21) iii. results and discussions in the first experiment, we conducted a distance ranging test for each uwb module. the main objective is to get maximum distance ranging ability and distance error measurement. figure 10 shows the experimental setup of the uwb module. this experiment was conducted to measure the distance between uwb tag and anchor. uwb anchor and computer is located in a fixed position. uwb tag was placed at a specific distance (1 m until 29 m). uwb anchor calculated the distance to uwb tag using sss-twr, sds-twr or ads-twr based radio signal. then the calculated distance was sent to a computer. this experiment compares symmetrical single sided-two way ranging (sss-twr), symmetrical double sided-two way ranging (sds-twr) and asymmetrical double sided-two way ranging (adstwr) to get an accurate ranging measurement. figure 11 shows uwb distance measurement using the sss-twr algorithm. the x-axis is the distance between uwb tag and anchor, and the y-axis is uwb anchor measurement value using the sss-twr algorithm. the result has been demonstrated that the uwb module can measure the maximum distance at 26.83 m. figure 12 shows the error reading. the x-axis is the distance between uwb tag and anchor, and the y-axis is the percent error measurement value. in 1 m measurements, uwb gets 12 % error measurement or equal to 0.12 m. then in 13 m measurement, uwb gets 2.3 % error measurement or equal to 0.299 m, and in 26 m measurement, uwb gets 0.69 % error measurement or equal 0.1794 m. the average error of symmetrical single sided-two way ranging algorithm is 2.73 %, the maximum error is 12.00 %, and the minimum error is 1.58 %. figure 13 shows uwb distance measurement using the sds-twr algorithm. the x-axis is the distance between uwb tag and anchor, and the yaxis is uwb anchor measurement value using the sds-twr algorithm. the result has been demonstrated that the uwb module can measure the maximum distance at 28.99 m. figure 14 shows error reading. the x-axis is the distance between uwb tag and anchor, and the y-axis is the percent error measurement value. in 1 m measurement, uwb gets 7.31 % error measurement or equal to 0.073 m. then in 13 m measurement, uwb gets 1.20 % error measurement or equal to 0.1547 m, and in 26 m measurement, uwb gets 2.0 % error measurement or equal to 0.4732 m. thus, symmetrical double sided-two way ranging (sdstwr) algorithm average error is 1.83 %, the maximum error is 7.31 %, and the minimum error is 0.64 %. figure 15 shows uwb distance measurement using the ads-twr algorithm. the x-axis is the distance between uwb tag and anchor, and the yaxis is uwb anchor measurement value using adstwr algorithm. the result has been demonstrated that the uwb module can measure the maximum figure 10. uwb transceiver distance ranging test set up n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 24 distance at 28.99 m. figure 16 shows the error reading. in 1 m measurement, uwb gets 8.1 % error measurement or equal to 0.081 m. then in 13 m measurement, uwb gets 0.64 % error measurement or equal to 0.0832 m, and in 26 m measurement, uwb gets 0.34 % error measurement or equal 0.084 m. asymmetrical double sided-two way ranging (ads-twr) algorithm average error is figure 11. sss-twr measurement result figure 12. sss-twr distance measurement error figure 13. sds-twr measurement result figure 14. ads-twr distance measurement error 0 5 10 15 20 25 30 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 u w b m ea su re m en t v al ue ( m ) distance (m) 0 2 4 6 8 10 12 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 er ro r ( % ) distance (m) 0 5 10 15 20 25 30 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 u w b m ea su re m en t va lu e (m ) distance (m) 0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 er ro r ( % ) distance (m) n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 25 1.38 %, the maximum error is 7.31 %, and the minimum error is 0.64 %. from the first experiment, ads-twr is superior to others by resulting in minimum distance error. ads-twr can measure longer distance than ssstwr and sds-twr. it also has minimal distance measurement error. ads-twr average error is 1.38 % (0.3588 m), sds-twr average error is 1.83 % (0.4758 m), sss-twr average error is 2.73 % (0.7098 m). the second experiment is uwb local positioning system implementation in autonomous vtol using ads-twr ranging measurement method, and calculate the position of autonomous vtol using trilateration method. figure 17 shows the documentation of the second experiment when using autonomous vtol hover. the orange area is dropping point. uwb tag is installed on autonomous vtol, and uwb anchor is installed on a tripod. figure 17 only shows +3 of 7 dropping points and 2 of 3 uwb anchors because the camera cannot capture all areas. figure 18 shows the autonomous vtol flight path. this experiment was carried out in an outdoor area (20.00 m x 30.00 m). we used autonomous vtol to drop seven payloads in a specific position. home location position (red square, 3 m x 3 m) is (1.50, 1.50), and dropping positions (yellow square, 2 m x 2 m) are (8.50, 11.00), (1.00, 15.00), (4.00, 22.5), (1.00, 28.00), (18.50, 26.00), (12.50, 20.00), (17.00, 7.50). initially, autonomous vtol took-off from home position (red square). autonomous vtol went to dropping point 1 and reached drop 1 position, and then autonomous vtol dropped the first payload successfully. next, autonomous vtol went to dropping point 2 and reached drop 2 position, and then autonomous vtol dropped the second payload successfully. autonomous vtol went to dropping point 3 and reached drop 3 position, and then autonomous vtol dropped the third payload successfully. next, autonomous vtol went to dropping point 4 and reached drop 4 position, and then autonomous vtol dropped the fourth payload successfully. autonomous vtol went to dropping point 5 and reached drop 5 position, and then autonomous vtol dropped the fifth payload successfully. next, autonomous vtol went to dropping point 6 and reached drop 6 position, and then autonomous vtol dropped the sixth payload successfully. autonomous vtol went to dropping point 7 and reached drop 7 position, and then autonomous vtol dropped the seventh payload successfully. next, autonomous vtol went to the home point and successfully reached the home position, then autonomous vtol land. this system can be used to localize the area for the dropping and landing of an autonomous vtol. figure 15. ads-twr measurement result figure 16. ads-twr distance measurement error 0 5 10 15 20 25 30 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 u w b m ea su re m en t v al ue ( m ) distance (m) 0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 er ro r ( % ) distance (m) n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 26 iv. conclusion we have compared sss-twr, sds-twr, and ads-twr uwb ranging measurement modes. adstwr can measure longer distance than sss-twr and sds-twr up to 29 m. ads-twr also has minimal distance measurement error. ads-twr average error is 1.38 % (0.3588 m), sds-twr average error is 1.83 % (0.4758 m), sss-twr average error is 2.73 % (0.7098 m). we also successfully implemented autonomous vtol quadcopter positioning in a small local outdoor area (20 m x 30 m). autonomous vtol has been able to drop seven payloads in seven areas (2 m x 2 m) and landed in the home position (3 m x 3 m) successfully. acknowledgement this research was funded by research unit of politeknik elektronika negeri surabaya (pens) to pens multirotor research team. the authors would like to thank pens and pens multirotor research team for supporting to publish this paper. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] s. akahori, y. higashi, and a. masuda, “position estimation system with uwb, imu and a distance sensor for quad-rotors,” in tencon 2017 2017 ieee region 10 conference, pp. 1992– 1996, 2017. [2] v. mai et al., “local positioning system using uwb range measurements for an unmanned blimp,” ieee robot. autom. lett., vol. 3, no. 4, pp. 2971–2978, 2018. [3] a. ledergerber and r. d’andrea, “calibrating away inaccuracies in ultra wideband range measurements: a maximum likelihood approach,” ieee access, vol. 6, pp. 78719–78730, 2018. [4] w. guosheng, q. shuqi, l. qiang, w. heng, l. huican, and l. bing, “uwb and imu system fusion for indoor navigation,” in 2018 37th chinese control conference (ccc), 2018, pp. 4946– 4950, 2018. [5] d. feng, c. wang, c. he, y. zhuang, and x.-g. xia, “kalmanfilter-based integration of imu and uwb for high-accuracy indoor positioning and navigation,” ieee internet things j., vol. 7, no. 4, pp. 3133–3146, 2020. [6] k. ren, g. bernes, m. hetta, and j. karlsson, “tracking and analysing social interactions in dairy cattle with real-time locating system and machine learning,” j. syst. archit., vol. 116, p. 102139, 2021. [7] a. d. ramadhani, p. kristalina, and a. sudarsono, “performance evaluation of refinement method in indoor localization,” in 2018 international electronics symposium on engineering technology and applications (ies-eta), 2018, pp. 183–188, 2018. [8] r. giuliano et al., “indoor localization system based on bluetooth low energy for museum applications,” electronics, vol. 9, no. 6, 2020. [9] m. pušnik, m. galun, and b. šumak, “improved bluetooth low energy sensor detection for indoor localization services,” sensors, vol. 20, no. 8, 2020. [10] s. cheng, s. wang, w. guan, h. xu, and p. li, “3dlra: an rfid 3d indoor localization method based on deep learning,” sensors, vol. 20, no. 9, 2020. [11] r. d. ainul, p. kristalina, and a. sudarsono, “hybrid filter scheme for optimizing indoor mobile cooperative tracking system,” telkomnika (telecommunication comput. electron. control., vol. 16, no. 6, pp. 2536–2548, 2018. [12] c. zhang, n. qin, y. xue, and l. yang, “received signal strength-based indoor localization using hierarchical classification,” sensors, vol. 20, no. 4, 2020. figure 17. second experiment documentation figure 18. recorded autonomous vtol flight path using uwb system https://mev.lipi.go.id/ https://doi.org/10.1109/tencon.2017.8228187 https://doi.org/10.1109/tencon.2017.8228187 https://doi.org/10.1109/tencon.2017.8228187 https://doi.org/10.1109/tencon.2017.8228187 https://doi.org/10.1109/lra.2018.2849553 https://doi.org/10.1109/lra.2018.2849553 https://doi.org/10.1109/lra.2018.2849553 https://doi.org/10.1109/access.2018.2885195 https://doi.org/10.1109/access.2018.2885195 https://doi.org/10.1109/access.2018.2885195 https://doi.org/10.1109/access.2018.2885195 https://doi.org/10.23919/chicc.2018.8483323 https://doi.org/10.23919/chicc.2018.8483323 https://doi.org/10.23919/chicc.2018.8483323 https://doi.org/10.23919/chicc.2018.8483323 https://doi.org/10.1109/jiot.2020.2965115 https://doi.org/10.1109/jiot.2020.2965115 https://doi.org/10.1109/jiot.2020.2965115 https://doi.org/10.1109/jiot.2020.2965115 https://doi.org/10.1016/j.sysarc.2021.102139 https://doi.org/10.1016/j.sysarc.2021.102139 https://doi.org/10.1016/j.sysarc.2021.102139 https://doi.org/10.1016/j.sysarc.2021.102139 https://doi.org/10.1109/elecsym.2018.8615498 https://doi.org/10.1109/elecsym.2018.8615498 https://doi.org/10.1109/elecsym.2018.8615498 https://doi.org/10.1109/elecsym.2018.8615498 https://doi.org/10.1109/elecsym.2018.8615498 https://doi.org/10.3390/electronics9061055 https://doi.org/10.3390/electronics9061055 https://doi.org/10.3390/electronics9061055 https://doi.org/10.3390/s20082336 https://doi.org/10.3390/s20082336 https://doi.org/10.3390/s20082336 https://doi.org/10.3390/s20092731 https://doi.org/10.3390/s20092731 https://doi.org/10.3390/s20092731 https://doi.org/10.12928/telkomnika.v16i6.10162 https://doi.org/10.12928/telkomnika.v16i6.10162 https://doi.org/10.12928/telkomnika.v16i6.10162 https://doi.org/10.12928/telkomnika.v16i6.10162 https://doi.org/10.3390/s20041067 https://doi.org/10.3390/s20041067 https://doi.org/10.3390/s20041067 n. tamami, b. sumantri, p. kristalina / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 18-27 27 [13] i. ashraf, s. hur, s. park, and y. park, “deeplocate: smartphone based indoor localization with a deep neural network ensemble classifier,” sensors, vol. 20, no. 1, 2020. [14] s. monica and f. bergenti, “an algorithm for accurate and robust indoor localization based on nonlinear programming,” electronics, vol. 9, no. 1, 2020. [15] p. ssekidde, o. steven eyobu, d. s. han, and t. j. oyana, “augmented cwt features for deep learning-based indoor localization using wifi rssi data,” appl. sci., vol. 11, no. 4, 2021. [16] p. li, x. yang, y. yin, s. gao, and q. niu, “smartphone-based indoor localization with integrated fingerprint signal,” ieee access, vol. 8, pp. 33178–33187, 2020. [17] t. koike-akino, p. wang, m. pajovic, h. sun, and p. v orlik, “fingerprinting-based indoor localization with commercial mmwave wifi: a deep learning approach,” ieee access, vol. 8, pp. 84879–84892, 2020. [18] x. peng, r. chen, k. yu, f. ye, and w. xue, “an improved weighted k-nearest neighbor algorithm for indoor localization,” electronics, vol. 9, no. 12, 2020. [19] h. s. maghdid, k. z. ghafoor, a. al-talabani, a. s. sadiq, p. k. singh, and d. b. rawat, “enabling accurate indoor localization for different platforms for smart cities using a transfer learning algorithm,” internet technol. lett., vol. n/a, no. n/a, p. e200. [20] s. sadowski, p. spachos, and k. n. plataniotis, “memoryless techniques and wireless technologies for indoor localization with the internet of things,” ieee internet things j., vol. 7, no. 11, pp. 10996–11005, 2020. [21] s. ranade and p. v manivannan, “quadcopter obstacle avoidance and path planning using flood fill method,” in 2019 2nd international conference on intelligent autonomous systems (icoias), pp. 166–170, 2019. [22] w. hönig, j. a. preiss, t. k. s. kumar, g. s. sukhatme, and n. ayanian, “trajectory planning for quadrotor swarms,” ieee trans. robot., vol. 34, no. 4, pp. 856–869, 2018. [23] j. shen, s. wang, y. zhai, and x. zhan, “cooperative relative navigation for multi-uav systems by exploiting gnss and peer-to-peer ranging measurements,” iet radar, sonar \& navig., vol. 15, no. 1, pp. 21–36, 2021. [24] f. gu, s. valaee, k. khoshelham, j. shang, and r. zhang, “landmark graph-based indoor localization,” ieee internet things j., vol. 7, no. 9, pp. 8343–8355, 2020. [25] i. ashraf, m. kang, s. hur, and y. park, “minloc:magnetic field patterns-based indoor localization using convolutional neural networks,” ieee access, vol. 8, pp. 66213–66227, 2020. https://doi.org/10.3390/s20010133 https://doi.org/10.3390/s20010133 https://doi.org/10.3390/s20010133 https://doi.org/10.3390/electronics9010065 https://doi.org/10.3390/electronics9010065 https://doi.org/10.3390/electronics9010065 https://doi.org/10.3390/app11041806 https://doi.org/10.3390/app11041806 https://doi.org/10.3390/app11041806 https://doi.org/10.3390/app11041806 https://doi.org/10.1109/access.2020.2974038 https://doi.org/10.1109/access.2020.2974038 https://doi.org/10.1109/access.2020.2974038 https://doi.org/10.1109/access.2020.2991129 https://doi.org/10.1109/access.2020.2991129 https://doi.org/10.1109/access.2020.2991129 https://doi.org/10.1109/access.2020.2991129 https://doi.org/10.3390/electronics9122117 https://doi.org/10.3390/electronics9122117 https://doi.org/10.3390/electronics9122117 https://doi.org/10.1002/itl2.200 https://doi.org/10.1002/itl2.200 https://doi.org/10.1002/itl2.200 https://doi.org/10.1002/itl2.200 https://doi.org/10.1002/itl2.200 https://doi.org/10.1109/jiot.2020.2992651 https://doi.org/10.1109/jiot.2020.2992651 https://doi.org/10.1109/jiot.2020.2992651 https://doi.org/10.1109/jiot.2020.2992651 https://doi.org/10.1109/icoias.2019.00036 https://doi.org/10.1109/icoias.2019.00036 https://doi.org/10.1109/icoias.2019.00036 https://doi.org/10.1109/icoias.2019.00036 https://doi.org/10.1109/tro.2018.2853613 https://doi.org/10.1109/tro.2018.2853613 https://doi.org/10.1109/tro.2018.2853613 https://doi.org/10.1049/rsn2.12023 https://doi.org/10.1049/rsn2.12023 https://doi.org/10.1049/rsn2.12023 https://doi.org/10.1049/rsn2.12023 https://doi.org/10.1109/jiot.2020.2989501 https://doi.org/10.1109/jiot.2020.2989501 https://doi.org/10.1109/jiot.2020.2989501 https://doi.org/10.1109/access.2020.2985384 https://doi.org/10.1109/access.2020.2985384 https://doi.org/10.1109/access.2020.2985384 introduction materials and methods a. software tag and anchor hardware design b. uwb ranging algorithm c. autonomous vtol specification d. method iii. results and discussions iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.47-54 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: t. a. tamba et al., “stability analysis of a hybrid dc-dc buck converter model using dissipation inequality and convex optimization,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 47-54, july 2023. stability analysis of a hybrid dc-dc buck converter model using dissipation inequality and convex optimization tua a. tamba a, *, jonathan chandra b, bin hu c a dept. electrical engineering, parahyangan catholic university jalan ciumbuleuit no. 94, bandung, 40141, indonesia b dept. mechanical engineering, university of groningen po box 72, 9700 ab groningen, groningen, 9712 ab, netherlands c dept. computer engineering technology & science, university of houston 4230 martin luther king boulevard, houston, tx 77204-4020, usa received 14 july 2022; 1st revision 19 may 2023; 2nd revision 28 may 2023; 3rd revision 3 june 2023; accepted 6 june 2023; published online 31 july 2023 abstract the stability analysis of a dc-dc buck converter is a challenging problem due to the hybrid systems characteristic of its dynamics. such a challenge arises from the buck converter operation which depends upon the on/off logical transitions of its electronic switch component to correspondingly activate different continuous vector fields of the converter’s temporal dynamics. this paper presents a sum of squares (sos) polynomial optimization approach for stability analysis of a hybrid model of buck converter which explicitly takes into account the converter’s electronic switching behavior. the proposed method first transforms the converter’s hybrid dynamics model into an equivalent polynomial differential algebraic equation (dae) model. an sos programming algorithm is then proposed to computationally prove the stability of the obtained dae model using lyapunov’s stability concept. based on simulation results, it was found that the proposed method requires only 8.5 seconds for proving the stability of a buck converter model. in contrast, exhaustive simulations based on numerical integration scheme require 15.6 seconds to evaluate the stability of the same model. these results thus show the effectiveness of the proposed method as it can prove the converter stability in shorter computational times without requiring exhaustive simulations using numerical integration. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: dc-dc buck converter; switched hybrid systems; lyapunov method; dissipation inequality; sos programming. i. introduction a dc-dc converter is an electronic device which transfers electric power from a dc voltage source to the loads [1]. such a transfer is achieved through the activation/inactivation of an electronic switch which causes the electric power to be transmitted from the source to power storage devices when the switch is activated (on) and then subsequently transferred from the storage device to the load when the switch is inactivated (off). the electronic switch is typically made of transistor and/or diode while the power storage devices usually consist of capacitor and/or inductor. the result of these power transfer processes is the converters output voltage whose value is proportional to the ratio of the durations of the on and off states of the switch [2]. in practice, there are two types of converters that are used in electronic applications, namely the step down (or buck) and step up (boost) converters. for a given source voltage value, the buck converter produces a lower output voltage while the boost converter generates a higher one. in this paper, our focus is to study and analyze the dynamics of a buck converter due to its frequent and widespread uses in household and industrial electronic devices which range from simple motor control [3] to the design of photovoltaic power systems [4] and electric vehicles [5]. * corresponding author. tel: +62-222032655; fax: +62-222032700 e-mail address: ttamba@unpar.ac.id https://dx.doi.org/10.14203/j.mev.2023.v14.47-54 https://dx.doi.org/10.14203/j.mev.2023.v14.47-54 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.47-54 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 48 based on its working principle, the buck converter can be viewed and modeled as switched hybrid systems (shs) whose dynamics may switch/jump from one discrete mode/state of operation into another in accordance to the on/off mode or state of its switch [6][7]. in particular, during the activation of either on or off mode, the converter state variables (e.g. current or voltage) evolve continuously in time according to the vector fields which define these states trajectories. the hybrid characteristics of a buck converter often give rise to nonlinear behaviors that are complex and at times difficult to characterize [8]. as a result, much of prior analysis works on buck converter dynamics were often done using their so-called averaged model for which the switching behaviors can simply be neglected [9]. while the use of this averaged model has so far resulted in various stability analysis and control synthesis methods, the fact that the construction of such a model essentially relies on the linearization/approximation methods limits their applicability to relatively small operational regions [10]. these suggest that more works remain needed to better understand the hybrid dynamics of buck converters [11][12]. this paper proposes the use of a computational method based on sos programming techniques [13] for analyzing the stability of a hybrid buck converter model. in the proposed method, the converter dynamics are first modeled as a two-mode shs in which the activation of each mode is triggered by the on/off state of the switch. the stability of the obtained shs model is analyzed using sufficient stability conditions in the form of a dissipation inequality [14]. an sos program to find a lyapunov function which satisfies the formulated dissipation inequality (thus certifies the shs stability) is then formulated [15]. numerical simulation results which illustrate the effectiveness of the proposed computational method are then presented. ii. materials and methods a. system description and model consider the schematic of a dc-dc buck converter in figure 1 [1]. in this figure, 𝑉𝑔 is the voltage source whose value needs to be decreased to meet the desired output voltage value at the resistor load r. both the inductor l and the capacitor c serve as temporary power storage elements for the input voltage from 𝑉𝑔 before being subsequently transferred to the load r as an output voltage. an additional resistor 𝑟𝐿 as shown in the schematic is added to describe parasitic electrical current/voltage which may occurs in the converter circuitry. the transfer of electrical power from the input 𝑉𝑔 to the output r which occurs in two subsequent modes is controlled by the sequence of activation of the electronic switches 𝑆1 and 𝑆2 as discussed below. in the first mode (denoted as mode 0), switch 𝑆1 is activated (on) while switch 𝑆2 is deactivated (off). in this case, the voltage source (𝑉𝑔 ), the storage elements (l and c) and the load (r) are connected and form two electrical loops. to model the dynamics in this mode, define a vector of state variables 𝑥 = [𝑖𝐿, 𝑣𝐶]𝑇 which consists of the current that passes through the inductor l and the voltage across the capacitor c. using kirchoff's laws, it can be shown that the dynamics of the converters state variables satisfy the following equation (1) [2], �̇�(𝑡) = 𝐴0𝑥(𝑡) + 𝐵0𝑢(𝑡) = � −𝑟𝐿 𝐶⁄ −1/𝐿 1/𝐶 −1/𝑅𝐶�𝑥(𝑡) + � 1/𝐿 0 �𝑢(𝑡) (1) where �̇�(𝑡) = 𝑑𝑑 (𝑡) 𝑑𝑡 denotes the time derivative of the state variables (no unit), 𝐴0 and 𝐵0 are constant state and input matrices (no units), 𝑟𝐿 is the parasitic resistance (ohm) in the circuit, 𝑢(𝑡) = 𝑉𝑔 has been defined as the system’s input. in the second mode (denoted as mode 1), switch 𝑆2 is activated (on) whereas switch 𝑆1 is deactivated (off). in this case, the voltage source (𝑉𝑔) is disconnected from both the power storage components (l and c) and the load (r). this implies that the two loops in mode 0 no longer include 𝑉𝑔 as their elements. as a result, the dynamics of the converter's state variables in mode 1 is simply governed by equation (2), �̇�(𝑡) = 𝐴1𝑥(𝑡) + 𝐵1𝑢(𝑡) = � −𝑟𝐿 𝐶⁄ −1/𝐿 1/𝐶 −1/𝑅𝐶�𝑥(𝑡) (2) where 𝐵1 = [0, 0]𝑇 by the mode definition. based on the above two operational modes, the buck converter dynamics may be modeled as an shs model of the form equation (3) [16], 𝑥(𝑡) = 𝐴𝜎(𝑡)𝑥(𝑡) + 𝐵𝜎(𝑡)𝑢(𝑡) (3) where 𝑥(𝑡) ∈ ℜ2 is the vector of state variables, 𝐴𝜎(𝑡) and 𝐵𝜎(𝑡) are the values of the constant state and figure 1. the schematic of a dc-dc buck converter t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 49 input matrices (no units) of the shs at switching signal value 𝜎(𝑡) , u(t) is the (control) input and 𝜎(𝑡): 𝑡 → {0, 1} is a switching signal which controls the mode that should be activated for a certain duration of time. it is thus clear that the shs in equation (3) consists of two modes with similar state variables such that it reduces to equation (1) if 𝜎(𝑡) = 0 or simplifies to equation (2) when 𝜎(𝑡) = 1. in practice, the value of 𝜎(𝑡) is usually regulated using a controller (e.g. pulse-width modulator) which sets the ratio of the time durations of the on/off states of each switch in term of a duty ratio parameter [17]. the presence of the switching signal 𝜎(𝑡) makes the analysis of the converter dynamics in equation (3) challenging. for instance, it is known that the overall dynamics of equation (3) can be unstable even if its subsystems are all stable. for this reason, considerable research efforts have been given in the last few decades to develop methods for analyzing the stability of shs in equation (3) [18]. currently, there are at least two main methods to do such analysis, i.e. using common lyapunov function (clf) [19] and multiple lyapunov functions (mlf) [20] methods. although theoretical basis for these methods have been established, their tractable computational implementations remain relatively unexplored. as in the case of standard lyapunovbased methods, this lack of computational implementation has mainly been caused by the difficulty in finding the corresponding clf or mlf [21]. this difficulty arises due to the fact that these methods essentially boil down to a problem of finding a nonnegative function that satisfies a set of nonlinear inequalities/equalities [22]. finding such a function is known to be a computationally hard problem because there currently does not exist provable algorithms with polynomial time complexity to solve it [23]. to address the above difficulty, this paper proposes the use of sos optimization techniques for analyzing the stability of the shs in equation (3). the proposed method first transforms the hybrid dynamics of the buck converter into an equivalent polynomial differential algebraic equation (dae) model [24]. using the obtained dae, this paper adopts a method from [14] to derive a dissipation inequality which defines the stability conditions of the resulting dae form. finally, an sos programming approach [25] for computing a lyapunov function which satisfies such an inequality is formulated. b. dae representation of switched hybrid systems we next describe a method to construct an equivalent dae model to represent the shs model in equation (3). let ℜ+ and ℜ𝑛 denote the sets of nonnegative real numbers and n-dimensional euclidean space, respectively. consider a general shs model in equation (4), �̇�(𝑡) = 𝑓𝜎(𝑡)(𝑥(𝑡), 𝑢(𝑡)) (4) where 𝑥(𝑡) ∈ ℜ𝑛 and 𝑢(𝑡) ∈ ℜ𝑚 denote the state and control vectors of the shs, respectively. 𝑓𝜎(𝑡) is a nonlinear function describing the vector fields of the system (no unit) when the switching signal 𝜎(𝑡) occurs. the function 𝜎(𝑡): [0, 𝑡𝑓) → 𝛩 ∈ {0,1, ⋯ , 𝑞} is the switching signal which is a piecewise constant function of time, and 𝑓𝑖(⋅) ∈ ℜ𝑛 × ℜ𝑚 × ℜ+ → ℜ𝑛 denotes a nonlinear function of the system vector fields when mode 𝑖 ∈ 𝛩 is active. to define a dae representation of equation (4), one first constructs a (row) drift vector 𝐹(𝑥, 𝑢) consisting the shs’s vector fields for all modes as in equation (5), 𝐹(𝑥, 𝑢): = [𝑓0(𝑥, 𝑢) 𝑓1(𝑥, 𝑢) ⋯ 𝑓𝑞(𝑥, 𝑢)] (5) next, let 𝛤(𝜎) be the quotient vector of the lagrange polynomial interpolation of 𝐹(𝑥, 𝑢) in equation (5) of the form equation (6), 𝛤(𝜎): = [ℓ0(𝜎) ℓ1(𝜎) ⋯ ℓ𝑞(𝜎)] (6) where ℓ is the quotient lagrange polynomial vector with elements ℓ𝑗 where 𝑗 = 0, … , 𝑞 , in which each element of 𝐿(𝜎) is defined in the switching variable 𝜎 as equation (7), ℓ𝑗(𝜎) = ∏ (𝜎−𝑖) (𝑗−𝑖) 𝑞 𝑖=0 𝑗=0 (7) where ℓ𝑗 for 𝑗 = 0, … , 𝑞 is the element of the quotient lagrange polynomial vector. the switching variable 𝜎 in the quotient vector equation (6) is constrained to take only integer values using polynomial function constraint in equation (8), 𝐷(𝜎): = ∏ (𝜎 − 𝑗)𝑞𝑗=0 = 0 (8) where 𝐷(𝜎) is a polynomial function constraint for the quotient lagrange polynomial of the switching function. in this regard, an equivalent representation of equation (3) in the form of polynomial dae model can be constructed using 𝐹(𝑥, 𝑢), 𝛤(𝜎), and 𝐷(𝜎) in equation (5), equation (6), and equation (8), respectively as equation (9) [13], �̇�(𝑡) = 𝐹(𝑥, 𝑢)𝛤(𝜎) (9) 0 = 𝐷(𝜎) c. sos programming sos programming is a variant of convex relaxation techniques in the context of polynomial optimization methods. the main idea in sos programming methods is the reformulation of equality/inequality constraints in the considered problem as sos polynomial conditions. let 𝛧+ be the set of nonnegative integers and consider a polynomial ring ℜ [𝑥] with unknown variables 𝑥 ∈ ℜ𝑛 and real-valued coefficients [26]. recall that a polynomial function 𝑉(𝑥) ∈ ℜ [𝑥] being an sos polynomial implies that 𝑉(𝑥) is also a positive definite (pd) function (i.e. 𝑉(𝑥) ≥ 0 for all 𝑥 ∈ ℜ𝑛 ). this implication in turn allows one to recast the determination of whether a polynomial function is sos or not as semidefinite programming (sdp) problems. specifically, a polynomial function 𝑉(𝑥) of degree 2d with 𝑑 ∈ 𝛧+ is an sos polynomial if there exist a pd matrix 𝑄𝑠 and a vector of monomials 𝛹(𝑥) of degree ≤ 𝑑 such that 𝑉(𝑥) can be decomposed as in equation (10) [27], 𝑉(𝑥) = 𝛹𝑇(𝑥)𝑄𝑆𝛹(𝑥) (10) t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 50 a key important point in equation (10) is that the construction of such a decomposition may be formulated and solved using sdp methods [28]. specifically, by specifying the vector of finite degree monomials 𝛹(𝑥), the construction of the decomposition in equation (10) boils down to the search for a positive definite matrix 𝑄𝑠 for which the equality in equation (10) holds [29]. this means various computational tools and solvers of semidefinite programming problems can be used to compute such a decomposition. the decomposition in equation (10) forms the basis for the formulation of an sos program. for instance, equation (10) can be used to simultaneously (i) determine if a polynomial 𝑉(𝑥) is pd and (ii) compute a positive lower bound 𝛾 > 0 for 𝑉(𝑥) using the sos program in equation (11), 𝑚𝑖𝑚 𝛾 (11) s.t. 𝑉(𝑥) − 𝛾 is sos note that if the solution 𝛾 in equation (11) is feasible, then the sos property of 𝑉(𝑥) guarantees that 𝑉(𝑥) − 𝛾 ≥ 0 holds, which thus implies 𝑉(𝑥) is a pd function that is lower bounded by the constant 𝛾 > 0. particularly, equation (11) is a convex sdp problem as it searches for a constant 𝛾 > 0 and a pd matrix 𝑄𝑠 such that 𝑉(𝑥) − 𝛾 = 𝛹𝑇(𝑥)𝑄𝑠𝛹(𝑥) holds. as such, various well-established computational tools in sdp methods can used to solve equation (11) [30]. iii. results and discussions a. dae representation of buck converter model for the shs model in equation (2), the polynomial dae representation in equation (9) can be constructed by noting that the system mode has such that. thus, the drift vector in equation (5) for this case is defined as 𝐹(𝑥, 𝑢): = [𝐴0𝑥(𝑡) 𝐴1𝑥(𝑡)]. on the other hand, the elements of the quotient polynomial interpolation are defined as ℓ0(𝜎) = � (𝜎 − 1) (0 − 1) 1 𝑖=1 𝑗=0 = 1 − 𝜎, ℓ1(𝜎) = � (𝜎 − 0) (1 − 0) 1 𝑖=0 𝑗=1 = 𝜎 such that the polynomial function is defined as 𝐷(𝑠): = ∏ (𝜎 − 𝑗)1𝑗=0 = 𝜎(𝜎 − 1). as a result, an equivalent polynomial dae representation of the shs equation (2) is defined as equation (12), �̇�(𝑡) = [𝐴0𝑥(𝑡) + 𝐵0𝑢(𝑡)](1 − 𝜎) + 𝐴1𝑥(𝑡)𝜎 = (𝐴0(1 − 𝜎) + 𝐴1𝜎)𝑥(𝑡) + 𝐵0(1 − 𝜎)𝑢(𝑡) 0 = 𝜎(𝜎 − 1) (12) b. stability analysis of dae system using dissipation inequality this section describes an sos programming formulation of a dissipation inequality which describes the sufficient stability conditions for the dae representation in equation (10) of the shs model in equation (3). in particular, this paper examines the use of lyapunov’s stability analysis method for studying the dynamics and stability of the dae system in equation (10). to begin with, consider a general model of nonlinear systems in equation (13), �̇�(𝑡) = 𝑓(𝑥(𝑡)) + 𝑔(𝑥(𝑡))𝑢(𝑡), 𝑥(0) = 𝑥0 (13) the equilibrium 𝑥∗ ≡ {𝑥|𝑓(𝑥) + 𝑔(𝑥)𝑢 = 0} of equation (5) is said to be lyapunov stable if there exists a function𝑉(𝑥): ℜ𝑛 → ℜ+ which satisfies: (i) 𝑉(𝑥) ≥ 0 and (ii) (𝛻𝑑𝑉)[𝑓(𝑥) + 𝑔(𝑥)𝑢(𝑡)] < 0 for all 𝑥 ∈ ℜ𝑛 in which (𝛻𝑑𝑉) = (𝜕𝑉(𝑥)/𝜕𝑥) [31]. for the dae system of the form equation (10), lyapunov stability analysis method may still be used through its reformulation in the form of a dissipation inequality. in this case, the system equilibrium vector [𝑥∗, 𝜎]𝑇 for a given u is defined as that for which conditions (i) 0 = [𝐴0𝑥∗ + 𝐵0𝑢(𝑇)](1 − 𝜎) + 𝐴1𝑥∗ and (ii) 0 = 𝜎(𝜎 − 1) hold. the following theorem from [14] establishes a sufficient stability condition for system equation (12). theorem 1 [14]: the equilibrium 𝑥∗of the dae in equation (4) is asymptotically stable if there exist a function 𝑉(𝑥): ℜ𝑛 → ℜ+, a scalar-valued function 𝜆(𝑥, 𝜎) > 0 and a function 𝛤(𝜎) = 0 such that the following dissipation inequality holds around 𝑥∗, (𝛻𝑑𝑉)[𝐴0𝑥 + 𝐵0𝑢](1 − 𝜎) + 𝐴1𝑥] < 𝜆(𝑥, 𝜎)𝛤2(𝜎) (14) theorem 1 essentially states that if a set of functions {𝑉(𝑥), 𝜆(𝑥, 𝜎), 𝛤(𝜎)} which satisfy the inequality in equation (14) exist simultaneously, then the equilibrium of dae in equation (12) is guaranteed to be asymptotically stable. unfortunately, such a search is known to be a computationally hard problem. however, if 𝑉(𝑥), 𝜆(𝑥, 𝜎) , and (𝜎) are polynomial functions, a tractable computation method for their search is available using techniques from sos programming. stability of shs in equation (12) can be examined using sos programming that corresponds to the result in theorem 1. c. sos programming algorithm for stability of dae model proposition 1 formulates an sos program based on the result in theorem 1. the main idea in this algorithm formulation is to relax the inequality constraints in equation (14) into sos polynomial constraints. proposition 1: the equilibrium of the shs model in equation (12) is asymptotically stable if there exist a polynomial function 𝑉(𝑥) ∈ ℜ [𝑥] sos, polynomial functions 𝜆(⋅) ∈ ℜ [𝑥, 𝜎] and 𝛤(⋅) ∈ ℜ [𝜎] such that the solution 𝛾 > 0 of the sos program in equation (15) to equation (19) is feasible, min γ s.t. 𝑉(𝑥) − 𝛾 is sos (15) γ2(𝜎)𝜆(𝑥, 𝜎) − (𝛻𝑑𝑉)�̇�(𝑡) is sos (16) 𝜆(𝑥, 𝜎) is sos (17) γ(𝜎) is sos (18) −γ(𝜎) is sos (19) proof: assume the solution of equation (9) is feasible. then there exists a constant 𝛾 > 0 which satisfies equation (15) to equation (19). such a satisfaction t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 51 thus particularly implies the existence of functions 𝜆(𝑥, 𝜎) ≥ 0 and 𝛤(𝜎) = 0. moreover, the satisfaction of equation (15) implies the existence of a pd function 𝑉(𝑥) ≥ 𝛾 > 0 with a lower bound of 𝛾 > 0. finally, the satisfaction of equation (16) implies 𝜆(𝑥, 𝜎)𝛤2(𝜎) − (𝛻𝑑𝑉)[𝐴0𝑥 + 𝐵0𝑢](1 − 𝜎) + 𝐴1𝑥] ≥ 0, which is essentially the condition in equation (14). by theorem 1, we conclude that the equilibrium of the shs equation (12) is asymptotically stable. the proof is thus completed. algorithm 1 details a computational method for the implementation of proposition 1. notice in this algorithm that 𝛤(𝜎) = 𝜎(𝜎 − 1) is explicitly defined even though it may also be defined as an unknown polynomial function in variable 𝜎 that needs to be searched simultaneously with 𝑉(𝑥), 𝛾 and 𝜆(𝑥, 𝜎) during the optimization’s iteration. this simply means that the decision variables of the optimization become larger. the explicit choice of 𝛤(𝜎) = 𝜎(𝜎 − 1) in algorithm 1 may thus be viewed as a way to reduce the computational load which otherwise may increase very fast when 𝛤(𝜎) is left as decision variable. algorithm 1 can be implemented in sos programming tools in conjunction with sdp solvers [32]. section iii.d illustrates an implementation of algorithm 1 for the shs model in equation (4). d. simulation experiments this section reports the simulation results of the implementation of algorithm 1 to analyze the stability of the shs model in equation (4). in the simulation, the model parameters of 𝑉𝑔 = 12 volt, 𝑅 = 50𝑘 𝛺, 𝑟𝐿 = 20.25 ω, 𝐿 = 0.33𝑚η and 𝐶 = 120 𝜇𝐹 were used. the shs model is assumed to operate with a duty cycle of 0.5. algorithm 1 is implemented in matlab [33] programming platform using sostool [27] and mosek [34] software tools under a core-i7, 4.2 ghz pc with 16 gb ram. for the shs model equation (4), algorithm 1 was solved in 8.5 seconds and gives a lyapunov function 𝑉(𝑥) of degree 𝑑𝑉 = 6 and an sos function 𝜆(𝑥, 𝜎) of degree 𝑑𝜆 = 6. the existence of such functions thus certify the asymptotic stability of the shs model in equation (10). for comparison, simulation experiments were also conducted for the dynamics of the shs model in equation (1) and equation (12) using a direct numerical integration method, as well as the buck converter dynamics based on the physical circuit in figure 1. the switching input signal is generated using a pulse width modulator (pwm) generator with a frequency of 𝑓𝑃𝑃𝑃 = 2𝐾𝐾𝐾. the measurable output of the system is assumed to be the output voltage across r. the simulations were conducted using matlab which is already integrated with simulink and simscape. figure 2 shows the block diagram of the three buck converter models that are used in the simulation. for the assumed model parameter values, simulations result of these models were obtained in 15.6 seconds which is longer than that required by the sos programming method. as shown in figure 3, the simulation results indicate similar stable behavior of the output voltages and reflect a resulting output voltage of 6 volts for the 12 volt input with 0.5 duty cycle. this thus verifies the stability property of the considered buck converter system as concluded by the existence of solution to the sos programming method in algorithm 1. the main advantage of using sos programming method is that it essentially mimics the feature of lyapunov’s stability analysis method whereby the stability of a system can be inferred/concluded based on the existence of lyapunov function and without having to rely on exhaustive simulation based on numerical integration methods. algorithm 1. sos program formulation in proposition 1 sos program for stability analysis of shs model in equation (4) input : matrices ,0 1a a and 1b for the shs model in equation (10) output: polynomial functions ( ), ( )v x xλ and a lower bound γ initialization: 1. define the polynomial ( ) (1)σ σ σγ = 2. set u to be a constant duty ratio input for the buck converter model sos program 3. define the vector of augmented decision variables [ , ] t x x σ= 4. construct a polynomial function template ( ) v x c xdv α α α∑= ≤ of degree dv with unknown coefficients cα in which α is a multi-index 5. construct a polynomial function template ( ) x c xd β λ β βλ ∑= ≤ of degree dλ with unknown coefficients cβ in which β is a multi-index 6. define a positive constant γ as the decision variable of the problem in equation (8) 7. declare the sos constraints (9b)–(9f) for the defined ( ), ( )v x xλ and ( )σγ 8. solve the sos program to find ( ), ( )v x xλ and γ t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 52 figure 2. matlab simulink/simscape model used in simulation (a) (b) (c) figure 3. output comparison of the state: (a) space; (b) dae; and (c) physical models t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 53 iv. conclusion this paper has presented a convex optimization approach for the analysis of an equivalent shs representation of dc-dc buck converter model. the proposed method first transforms the hybrid dynamics of the buck converter into an equivalent polynomial differential algebraic equation (dae) model. the method then formulates an sos programming algorithm for searching a lyapunov functions which satisfy a dissipation inequality condition on the obtained dae model that is sufficiently required to guarantee the asymptotic stability of the equilibrium point of the shs model. numerical simulation results show that the proposed method can prove the stability of the system in a relatively shorter computational time without relying on exhaustive simulations of the systems’ dynamics. future works will extend the proposed approach to synthesize stabilizing controller for the shs method. other possible directions include the implementation of other polynomial optimization approaches such as the method of moments for characterizing the stability property of shs models as well as analyzing more complex and nonlinear hybrid model of switched hybrid power converters. acknowledgements this research was supported by the directorate general for higher education, research, and technology of the ministry of education, culture, research, and technology of the republic of indonesia under the regular fundamental research grant year 2023. declarations author contribution t.a. tamba: writing original draft, review & editing, conceptualization, formal analysis, investigation, visualization, supervision. j. chandra: validation, data curation. b. hu: resources, software. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] j. machowski, z. lubosny, j. w. bialek, and j. r. bumby, power system dynamics: stability and control, 3rd ed., vol. 1. new jersey: john wiley & sons, 2020. [2] m. z. hossain, n. a. rahim, and j. selvaraj, “recent progress and development on power dc-dc converter topology, control, design and applications: a review,” renew. sustain. energy rev., vol. 81, no. 1, pp. 205–230, jan. 2018. [3] p. irasari, k. wirtayasa, p. widiyanto, m. f. hikmawan, and m. kasim, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” j. mechatronics, electr. power, veh. technol., vol. 12, no. 1, pp. 1–9, jul. 2021. [4] r. ristiana, a. s. rohman, e. rijanto, a. purwadi, e. hidayat, and c. machbub, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” j. mechatronics, electr. power, veh. technol., vol. 9, no. 2, pp. 89–100, dec. 2018. [5] a. r. hakim, w. t. handoyo, and p. wullandari, “an energy and exergy analysis of photovoltaic system in bantul regency, indonesia,” j. mechatronics, electr. power, veh. technol., vol. 9, no. 1, pp. 1–7, jul. 2018. [6] s. mariethoz et al., “comparison of hybrid control techniques for buck and boost dc-dc converters,” ieee trans. control syst. technol., vol. 18, no. 5, pp. 1126–1145, sep. 2010. [7] m. dhananjaya and s. pattnaik, “review on multi-port dc–dc converters,” iete tech. rev., vol. 39, no. 3, pp. 586–599, 2022. [8] x. lin and r. zamora, “controls of hybrid energy storage systems in microgrids: critical review, case study and future trends,” j. energy storage, vol. 47, no. 1, p. 103884, 2022. [9] m. e. şahin and h. i̇. okumuş, “parallel-connected buck–boost converter with flc for hybrid energy dystem,” electr. power components syst., vol. 48, no. 19–20, pp. 2117–2129, dec. 2020. [10] m. a. r. licea, f. j. p. pinal, a. i. b. gutiérrez, c. a. h. ramírez, and j. c. n. perez, “a reconfigurable buck, boost, and buckboost converter: unified model & robust controller,” math. probl. eng., vol. 2018, no. 6251787, pp. 1–8, 2018. [11] w. hu, r. yang, x. wang, and f. zhang, “stability analysis of voltage controlled buck converter feed from a periodic input,” ieee trans. ind. electron., vol. 68, no. 4, pp. 3079–3089, apr. 2021. [12] m. e. şahin and h. i̇. okumuş, “comparison of different controllers and stability analysis for photovoltaic powered buck-boost dc-dc converter,” electr. power components syst., vol. 46, no. 2, pp. 149–161, jan. 2018. [13] j. d. hauenstein, a. c. liddell, s. mcpherson, and y. zhang, “numerical algebraic geometry and semidefinite programming,” results appl. math., vol. 8, no. 11, p. 100166, aug. 2021. [14] e. mojica-nava, n. quijano, n. rakoto-ravalontsalama, and a. gauthier, “a polynomial approach for stability analysis of switched systems,” syst. control lett., vol. 59, no. 2, pp. 98– 104, feb. 2010. [15] g. fantuzzi, “verification of some functional inequalities via polynomial optimization,” ifac-papersonline, vol. 55, no. 16, pp. 166–171, 2022. [16] x. cheng, j. liu, and z. liu, “accurate small-signal modeling and stability analysis of wide-input buck converter considering modulation waveform ripples,” ieee trans. power electron., vol. 37, no. 6, pp. 6962–6971, jun. 2022. [17] l. xiong, x. liu, y. liu, and f. zhuo, “modeling and stability issues of voltage-source converter dominated power systems: a review,” csee j. power energy syst., vol. 8, no. 6, pp. 1530– 15349, nov. 2020. [18] r. goebel, r. g. sanfelice, and a. r. teel, “hybrid dynamical systems,” ieee control syst., vol. 29, no. 2, pp. 28–93, apr. 2009. [19] s. andersen, p. giesl, and s. hafstein, “common lyapunov functions for switched linear systems: linear programmingbased approach,” ieee control syst. lett., vol. 7, no. 1, pp. 901–906, 2022. [20] y. zhu and w. x. zheng, “multiple lyapunov functions analysis approach for discrete-time-switched piecewiseaffine systems under dwell-time constraints,” ieee trans. automat. contr., vol. 65, no. 5, pp. 2177–2184, may 2020. [21] y. tang and y. li, “common lyapunov function based stability analysis of vsc with limits of phase locked loop,” ieee trans. power syst., vol. 38, no. 2, pp. 1759–1762, 2023. https://mev.lipi.go.id/ https://www.google.co.id/books/edition/power_system_dynamics/qudsdwaaqbaj?hl=en&gbpv=0 https://www.google.co.id/books/edition/power_system_dynamics/qudsdwaaqbaj?hl=en&gbpv=0 https://www.google.co.id/books/edition/power_system_dynamics/qudsdwaaqbaj?hl=en&gbpv=0 https://doi.org/10.1016/j.rser.2017.07.017 https://doi.org/10.1016/j.rser.2017.07.017 https://doi.org/10.1016/j.rser.2017.07.017 https://doi.org/10.1016/j.rser.2017.07.017 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://dx.doi.org/10.14203/j.mev.2021.v12.1-9 https://doi.org/10.14203/j.mev.2018.v9.89-100 https://doi.org/10.14203/j.mev.2018.v9.89-100 https://doi.org/10.14203/j.mev.2018.v9.89-100 https://doi.org/10.14203/j.mev.2018.v9.89-100 https://doi.org/10.14203/j.mev.2018.v9.89-100 https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 https://dx.doi.org/10.14203/j.mev.2018.v9.1-7 https://doi.org/10.1109/tcst.2009.2035306 https://doi.org/10.1109/tcst.2009.2035306 https://doi.org/10.1109/tcst.2009.2035306 https://doi.org/10.1080/02564602.2021.1882343 https://doi.org/10.1080/02564602.2021.1882343 https://doi.org/10.1016/j.est.2021.103884 https://doi.org/10.1016/j.est.2021.103884 https://doi.org/10.1016/j.est.2021.103884 https://doi.org/10.1080/15325008.2021.1913261 https://doi.org/10.1080/15325008.2021.1913261 https://doi.org/10.1080/15325008.2021.1913261 https://doi.org/10.1080/15325008.2021.1913261 https://doi.org/10.1155/2018/6251787 https://doi.org/10.1155/2018/6251787 https://doi.org/10.1155/2018/6251787 https://doi.org/10.1155/2018/6251787 https://doi.org/10.1109/tie.2020.2982116 https://doi.org/10.1109/tie.2020.2982116 https://doi.org/10.1109/tie.2020.2982116 https://doi.org/10.1109/tie.2020.2982116 https://doi.org/10.1080/15325008.2018.1436617 https://doi.org/10.1080/15325008.2018.1436617 https://doi.org/10.1080/15325008.2018.1436617 https://doi.org/10.1080/15325008.2018.1436617 https://doi.org/10.1016/j.rinam.2021.100166 https://doi.org/10.1016/j.rinam.2021.100166 https://doi.org/10.1016/j.rinam.2021.100166 https://doi.org/10.1016/j.rinam.2021.100166 https://doi.org/10.1016/j.sysconle.2009.12.004 https://doi.org/10.1016/j.sysconle.2009.12.004 https://doi.org/10.1016/j.sysconle.2009.12.004 https://doi.org/10.1016/j.sysconle.2009.12.004 https://doi.org/10.1016/j.ifacol.2022.09.018 https://doi.org/10.1016/j.ifacol.2022.09.018 https://doi.org/10.1016/j.ifacol.2022.09.018 https://doi.org/10.1109/tpel.2022.3140851 https://doi.org/10.1109/tpel.2022.3140851 https://doi.org/10.1109/tpel.2022.3140851 https://doi.org/10.1109/tpel.2022.3140851 https://doi.org/10.17775/cseejpes.2020.03590 https://doi.org/10.17775/cseejpes.2020.03590 https://doi.org/10.17775/cseejpes.2020.03590 https://doi.org/10.17775/cseejpes.2020.03590 https://doi.org/10.1109/mcs.2008.931718 https://doi.org/10.1109/mcs.2008.931718 https://doi.org/10.1109/mcs.2008.931718 https://doi.org/10.1109/lcsys.2022.3228857 https://doi.org/10.1109/lcsys.2022.3228857 https://doi.org/10.1109/lcsys.2022.3228857 https://doi.org/10.1109/lcsys.2022.3228857 https://doi.org/10.1109/tac.2019.2938302 https://doi.org/10.1109/tac.2019.2938302 https://doi.org/10.1109/tac.2019.2938302 https://doi.org/10.1109/tac.2019.2938302 https://doi.org/10.1109/tpwrs.2022.3233762 https://doi.org/10.1109/tpwrs.2022.3233762 https://doi.org/10.1109/tpwrs.2022.3233762 t.a. tamba et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 47-54 54 [22] y. zheng, g. fantuzzi, and a. papachristodoulou, “chordal and factor-width decompositions for scalable semidefinite and polynomial optimization,” annu. rev. control, vol. 52, pp. 243–279, dec. 2021. [23] j. h. lee, n. sisarat, and l. jiao, “multi-objective convex polynomial optimization and semidefinite programming relaxations,” j. glob. optim., vol. 80, no. 1, pp. 117–138, 2021. [24] s. yuan, m. lv, s. baldi, and l. zhang, “lyapunov-equationbased stability analysis for switched linear systems and its application to switched adaptive control,” ieee trans. automat. contr., vol. 66, no. 5, pp. 2250–2256, 2020. [25] d. jagt, s. shivakumar, p. seiler, and m. peet, “efficient data structures for representation of polynomial optimization problems: implementation in sostools,” ieee control syst. lett., vol. 6, no. 1, pp. 3493–3498, 2022. [26] c. wang, z. h. yang, and l. zhi, “global optimization of polynomials over real algebraic sets,” j. syst. sci. complex., vol. 32, no. 1, pp. 158–184, 2019. [27] a. papachristodoulou et al., “sostools version 4.00 sum of squares optimization toolbox for matlab,” arxiv 1310.4716, pp. 1–71, 2021. [28] g. averkov, “optimal size of linear matrix inequalities in semidefinite approaches to polynomial optimization,” siam j. appl. algebr. geom., vol. 3, no. 1, pp. 128–151, 2019. [29] s. behrends and a. schöbel, “generating valid linear inequalities for nonlinear programs via sums of squares,” j. optim. theory appl., vol. 186, no. 1, pp. 911–935, 2020. [30] a. yurtsever, j. a. tropp, o. ercoq, m. udell, and v. cevher, “scalable semidefinite programming,” siam j. math. data sci., vol. 3, no. 1, pp. 171–200, 2021. [31] h. k. khalil, nonlinear control. essex: pearson, 2015. [32] a. majumdar, g. hall, and a. a. ahmadi, “recent scalability improvements for semidefinite programming with applications in machine learning, control, and robotics,” annu. rev. control. robot. auton. syst., vol. 3, pp. 331–360, 2020. [33] the mathworks inc., “matlab version: 9.12.0 (r20221).” the mathworks inc., natick, massachusetts, 2022, [online]. available: https://www.mathworks.com. [34] m. aps, “mosek optimization toolbox for matlab 10.0.46,” mosek user’s guide and reference manual, may 23, 2023. https://doi.org/10.1016/j.arcontrol.2021.09.001 https://doi.org/10.1016/j.arcontrol.2021.09.001 https://doi.org/10.1016/j.arcontrol.2021.09.001 https://doi.org/10.1016/j.arcontrol.2021.09.001 https://doi.org/10.1007/s10898-020-00969-x https://doi.org/10.1007/s10898-020-00969-x https://doi.org/10.1007/s10898-020-00969-x https://doi.org/10.1109/tac.2020.3003647 https://doi.org/10.1109/tac.2020.3003647 https://doi.org/10.1109/tac.2020.3003647 https://doi.org/10.1109/tac.2020.3003647 https://doi.org/10.1109/lcsys.2022.3183650 https://doi.org/10.1109/lcsys.2022.3183650 https://doi.org/10.1109/lcsys.2022.3183650 https://doi.org/10.1109/lcsys.2022.3183650 https://doi.org/10.1007/s11424-019-8351-5 https://doi.org/10.1007/s11424-019-8351-5 https://doi.org/10.1007/s11424-019-8351-5 https://doi.org/10.48550/arxiv.1310.4716 https://doi.org/10.48550/arxiv.1310.4716 https://doi.org/10.48550/arxiv.1310.4716 https://doi.org/10.1137/18m1201342 https://doi.org/10.1137/18m1201342 https://doi.org/10.1137/18m1201342 https://doi.org/10.1007/s10957-020-01736-4 https://doi.org/10.1007/s10957-020-01736-4 https://doi.org/10.1007/s10957-020-01736-4 https://doi.org/10.1137/19m1305045 https://doi.org/10.1137/19m1305045 https://doi.org/10.1137/19m1305045 http://www.pearson.com/en-gb/subject-catalog/p/nonlinear-control-global-edition/p200000004622 https://doi.org/10.1146/annurev-control-091819-074326 https://doi.org/10.1146/annurev-control-091819-074326 https://doi.org/10.1146/annurev-control-091819-074326 https://doi.org/10.1146/annurev-control-091819-074326 https://www.mathworks.com/products/optimization.html https://www.mathworks.com/products/optimization.html https://www.mathworks.com/products/optimization.html https://docs.mosek.com/latest/toolbox/index.html https://docs.mosek.com/latest/toolbox/index.html introduction ii. materials and methods a. system description and model b. dae representation of switched hybrid systems c. sos programming iii. results and discussions a. dae representation of buck converter model b. stability analysis of dae system using dissipation inequality c. sos programming algorithm for stability of dae model d. simulation experiments iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.28-37 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia proteus isis simulation for power factor calculation using zero crossing detector jumrianto a, *, royan b a system and information technology department, ivet university jl. pawiyatan luhur, semarang, 50235, indonesia b electromedical engineering department, muhammadiyah university purwokerto, jl. kh. ahmad dahlan purwokerto, banyumas, 53182, indonesia received 21 february 2021; accepted 3 june 2021; published online 31 july 2021 abstract one of the important parameters for electrical systems is the power factor (cos phi), which is the ratio of the real power (watt) to the apparent power (volt ampere). the best cos phi value is between 0.85 to 1. a resistive load causes the voltage and current in equal phase angle, while the inductive load causes the current to lag behind the voltage. on the other hand, the capacitive load causes the current to precede the voltage (leading). a simulation to determine the power factor of an electrical network can be done with proteus isis software by creating a phase detection circuit. automatic control can be done by a microcontroller. this simulation circuit can be used as power factor correction, a trigger angle on scr trigger for dc motor speed control, for rocket launch angle adjuster, to measure the angle of inclination, and other uses relating to angle adjustments. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: power factor; cos phi; zero-crossing. i. introduction power quality determines the reliability of the electrical system. one of the important parameters to be considered for electrical system reliability is a power factor (cos phi). power factor is determined by how far the phase degree difference (cos) between voltage and current. understanding the power factor and how it affects the utility bill can help reduce electricity costs. the effect of load on generator performance, particularly output power, efficiency, and voltage regulation, can be seen by designing two types of simulated loads: pure resistive and series resistive-inductive loads. each type of load provides a power factor of 1 and 0.85, respectively. the simulation results show that the generator gives better performance when loaded with resistive loads [1]. the sepic converter works in intermittent conduction mode and functions as a power factor corrector so that the input current waveform follows the input voltage waveform. the full-bridge dc-dc converter functions as an output voltage regulator and operates in a continuous conduction mode, where the power factor of this converter system can achieve up to 0.96 [2]. if the current and voltage are both sinusoidal in one phase, the power factor is 1.0. if both are sinusoidal but in phase difference, the power factor is the cosine of the phase angle [3]. zero-crossing detector functions as a triggering start for the pwm signal so that the fan speed and light brightness can be adjusted [4]. zero-crossing detectors are used to synchronize switching with the ac wavelength or to extract the timing signal. by using zero-crossing techniques, high inrush currents can be avoided [5]. the zerocrossing detector circuit functions well as a voltage safety net for the indonesian state electricity company [6]. different approaches are used for zerocrossing: hardware or software. the hardware approach is simple, but it has low precision. on the other hand, the software approach has high precision, but it is complicated and expensive [7]. zero-voltage cross detection is commonly used as an accurate method of detecting ac characteristics, such as frequency and phase. the zero-crossing point is ideally suited for measuring ac signals for several reasons. a comparator is similar to an operational amplifier (op-amp). it has two inputs, * corresponding author. phone: +62-813-4592-0696 e-mail address: jumrianto@ivet.ac.id https://dx.doi.org/10.14203/j.mev.2021.v12.28-37 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.28-37 https://dx.doi.org/10.14203/j.mev.2021.v12.28-37 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.28-37&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 29 inverting and non-inverting, and an output, but it is specifically designed to compare the voltages between its two inputs. a suitable zero-crossing circuit is often needed for devices such as lighting controllers, thermostats, motor drives, and similar ac-load controlling or monitoring applications, often needs mains phase and/or frequency information [8]. ii. materials and methods the phase difference is obtained by comparing the phase voltage and phase currents drawn by the load. the voltage and current waves of a sensor are still sine signals where the two phases are different [9]. a comparator is used to distinguish between two different signal levels [10]. comparator is similar to op-amp. a comparator has two inputs (inverting/non-inverting) and output. a comparator is a digital circuit in which all the output values are expressed as "yes = 1" or "no = 0". to facilitate the processing of a sine wave, a comparator is used to convert a sine wave into a square wave. among the ics that can be used is ic lm324, which has a 5 volt dc power supply source. a. comparator the phase difference detector is made using comparator and exclusive-or logic gates. the comparator is used to convert a sine wave into a square wave, while the exclusive-or logic gate is used to pass a square wave (value 1) only when the two inputs are different. if the input waveform is equal, either equals 0 or equals 1, then the output will be 0. the length of time the output is 0 or 1 depends on the magnitude of the phase angle. the cos difference value is obtained by calculating the time interval between the rising voltage and the down voltage at the exclusive-or logic gate output [11]. design of a comparator block using one of the facilities provided by operational amplifier (opamp) type lm-324 [9]. the schematic image of ic lm-324 [12] used as a comparator is shown in figure 1. b. exclusive-or logic gates (ex-or) the exclusive-or logic gate used is ic 74ls86. the term exclusive-or is abbreviated as ex-or. the ic used as a detector of phase difference output is ic 74ls86, as shown in figure 2 [13]. the exclusive-or gate will only open when an odd number unit appears in the input [14]. c. power factor power is measured in watts. watt is the voltage multiplied by the current multiplied by the power factor. watts are just the same as the volts multiplied by amperes when the power factor is 1, but most of the power factor is less than 1 [15]. the power factor value depends on the phase difference between the current and voltage [11]. when electricity is applied to a pure inductor, no real work is done, and no heat or light is produced. the reactive power is measured in kilo-voltampere-reactive (kvar). examples of inductive loads are transformers, motors, and lighting ballast. the current through one of these r, l, and c components will have the same ac frequency as the voltage source that drives the current. in other words, there exists a phase shift between current and voltage. the resistive element is the only component that produces clean energy. the actual power consumed by a circuit is real power in watts, the voltage and current might not be in one phase. figure 3 forms a power triangle where the apparent side is rms volt multiplied by rms ampere. this is called the apparent power (s) and has a unit of volt-amp (va). the real power is expressed by p = vi cos θ, which is the real power in watts. the vertical side of the triangle, q = vi sin θ, is called reactive power and has a volt-amps-reactive var unit. reactive var power is not capable of doing any work [16]. figure 3 shows the power triangle [17]. figure 1. schematic diagram of ic lm-324 figure 2. schematic diagram of ic 74ls86 figure 3. the power triangle displays the apparent power s (voltamp) converted to reactive power (var) and real power p (watts) jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 30 d. zero-rrossing detector in zero cross detection method for the time synchronization purpose is based on phase locked loop. simulation schema is introduced to examine and analyze pll behavior under different grid interferences. two potential issues multiple zerocrossing in the zero cross-area may cause instability of the loop and the presence of harmonics may cause shifts of the zero-cross event [18]. a zero-crossing detector circuit is an important application of an opamp comparator circuit. it can also be referred to as a sine to a square wave converter. all inverting or non-inverting comparators can be used as zerocrossing detectors. the input sine wave is given as vin [19]. comparators are used to distinguish between two different signal levels. for example, a comparator can distinguish between excessive temperature and normal temperature conditions [10]. zero voltage detection is generally used as an accurate method for detecting ac characteristics, such as frequency and phase. the ideal zero-cross point for measuring signal [20]. a zero-crossing detector can have two types of output signals. the zero-crossing should be during the transition between positive and negative input signals [7]. zero-crossing is the point of choice for measuring phase and frequency. references are usually easy to establish and the rate of change in maximum signal amplitude at zero signal [21]. the input and output wave graphs in the zero-crossing circuit of the phase difference detector can be seen in figure 4. from figure 5 it is stated that θ is the phase angle (cos) sought after being converted to an angle in degrees. phi (φ) can be calculated by the following formula: φ = δt / t x 3600 [11] (1) δt t he square w ave i n figure 5 is the cos value in time, since cos is in proportion to cos in degrees and is inversely proportional to the value of cos phi. in figure 5, v(t) and i(t) is a square wave for input and δt is a square wave for output. from figure 5, cos can be calculated by the following formula: φ = δt / 0.5t x 1800 [9] (2) where: φ = phase difference in degrees (°), δt = phase difference in time (ms), t 1/2 t = half time period signal (ms). cosine value of the phase difference in angle is the value of power factor sought. e. isis proteus simulation software isis stands for intelligent schematic input system and is one of the simulation programs that is integrated with proteus and has become its main program. isis was designed as a medium for drawing electronic circuit schematics in accordance with international standards. with pcb layouts now offering component placement automation and routing paths, getting the design into a computer can often be the most time-consuming element of practice. f. simulation set-up the main circuit design of the power factor calculation is shown in figure 6. 1) design a differential phase detector (zerocrossing detector) the phase difference between the voltage and current can be detected by a zero-crossing detector. the zero-crossing detector phase difference circuit is shown in figure 7. voltage and current waves at voltage sensor and the current sensor through the comparator, the output of the lm 324 ic will be fed to an exclusiveor logic gate that can detect the time rising edge and time falling edge at the voltage and current waves. 2) set the input current phase as a simulation of phase change between the input current voltage, cos is done in degrees as the angle varies. figure 4. sinus waves, square wave, and cos in (t) figure 5. regular and cos wave in (t) jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 31 3) running the simulation the voltage and current waves are displayed by starting the simulation and pressing the play button on the left corner of the computer or laptop. 4) displays digital oscilloscope the oscilloscope can be seen by right-clicking on the digital oscilloscope. a square wave of inputs and outputs in the oscilloscope will appear. after the wave appears, point the cursor at the start of the ascending wave and the end of the wave down on the positive side. phi value in time is 9.9 ms 5.9 ms = 4 ms. 5) convert the phi value to cos phi the value of δt is converted to phi by the formula: φ = (δt / 0.5t) x 180 or cos = (δt / t) x 360, then by calculating the value of phi, we get the value of power factor (cos phi). iii. results and discussions the test results show that there is a change in phase angle when the phase of the input current is increased or decreased. the phase angle change value is shown in table 1. the value of cos phi recommended by the indonesian electrical power company is 0.85 to 1, then the analysis of cos phi starts from the value of 31.5° to 0°. from table 1, it can be seen that by changing the phase angle of the input current in degrees, we can calculate the value of cos phi with the following analysis: figure 6. main circuit design connected to a microcontroller figure 7. draw zero-crossing detector circuit jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 32 a. phase current analysis over phase voltage 1) phase current precedes phase voltage at 31.5° the phase current precedes the phase voltage of 31.5°. the current and voltage waves can be seen in figure 8. the incoming and outgoing square wave of ic 74ls74 with a phase angle of 31.5° is shown in figure 9. the output wave ic of ic 74ls86 is an indicator of the enlarged phase difference to find the time duration of the voltage rises until the voltage drops, which is used as a phase or cos phase in time. cos in time is converted to degrees before converted into cos phi to be known. figure 10 shows the phase difference in units of time. when the phase difference is 31.5°, the value of δt can be determined by measuring the output pulse ic 74ls74, when the pulse is up at 8.20 ms. when the pulse drops at 9.90 ms, then δt is δt = 29.9828.23 = 1.75 ms. therefore, the value of phi is φ = (1.75 / 10) x 180; φ = 0.175 x 180; φ = 31.5°; then the value of cos phi is cos phi = cos 31.5° = 0.852. 2) phase current precedes phase voltage at 27° when the phase current precedes the phase voltage of 27°, the current and voltage waves can be seen in figure 11. the incoming and outgoing square wave of ic 74ls74 at 27° phase is shown in figure 12. cos in time is converted to degrees and then converted into cos phi to be known, as shown in figure 13. when the phase difference is 27°, the value of δt can be determined by measuring the table 1. comparison of phase angle (cos) in time, in angle (°) and cos phi no angle (degree) time (millisecond) cos phi 1 0 0 1 2 4.5 0.25 0.997 3 9 0.5 0.987 4 13.5 0.75 0.972 5 18 1 0.951 6 22.5 1.25 0.923 7 27 1.5 0.891 8 31.5 1.75 0.852 figure 8. current phase precedes a voltage of 31.5°: (1 and 3): wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm-324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 11. current phase precedes a voltage of 27°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 9. wave input and output ic 74ls86 with the phase angle 31.5°; (1) current-phase currents; (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 12. wave input and output ic 74ls86 at phase angle 27°. (1) current-phase currents (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 10. square wave as an indicator of phase difference at phase difference 31.5°: (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time figure 13. square wave as an indicator of phase difference at moment 27°. (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 33 output pulse ic 74ls74. when the pulse rises at 8.5 ms and drops at 10 ms, then δt is δt = 10 8.5 = 1.5 ms. therefore, the value of phi is φ = (1.5 / 10) x 180; φ = 0.15 x 180; φ = 27°. then the value of cos phi is cos phi = cos 27° = 0.891. 3) phase current over phase voltage at 22.5° when the phase current precedes the phase voltage of 22.5°, the current and voltage waves can be seen in figure 14. the incoming and outgoing square wave of ic 74ls74 when the phase angle is 22.5° is shown in figure 15. cos in time is converted to degrees before converted to cos phi, which is shown in figure 16. when the phase difference is 22.5°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse rises at 8.75 ms and drops at 10 ms, then δt is δt = 10 8.75 = 1.25 ms. therefore, the value of phi is φ = (1.25 / 10) x 180; φ = 0.125 x 180 ; φ = 22.5°, then the value of cos phi is cos phi = cos 22.5° = 0.923. 4) phase current over phase voltage at 18° when phase current precedes a phase voltage of 18°, the current and voltage waves can be seen in figure 17. a square wave is in and out of ic 74ls74 at the phase angle of 18°, as shown in figure 18. cos in time is converted to degrees and converted into cos phi to be known, as shown in figure 19. when the phase difference is 18°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse is up at 8.9 ms and drops at 9.9 ms, the δt is δt = 9.9 8.9 = 1 ms. therefore, the value of phi is φ = (1/10) x 180; φ = 0.1 x 180; φ = 18°. the value of cos phi is cos phi = cos 18° = 0.951. figure 14. current phase precedes a voltage of 22.5°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm-324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 17. current phase precedes a voltage of 18°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 15. wave input and output ic 74ls86 at phase angle 22.5°. (1) current-phase currents; (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 18. wave input and output ic 74ls86 at phase angle 18°. (1) current-phase currents; (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 16. square wave as an indicator of phase difference at a different phase of 22.5°. (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time figure 19. square wave as an indicator of phase difference at a different phase of 18°. (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 34 5) phase current over phase voltage at 13.5° when the phase current precedes a phase voltage of 13.5°, the current and voltage waves can be seen in figure 20. a square wave is in and out of ic 74ls74 at phase angle 13.5°, as shown in figure 21. cos in time is converted to degrees before converted to cos phi as shown in figure 22. when the phase difference is 13.5°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse rises at 9.25 ms and drops at 10 ms, the δt is δt = 10 – 9.25 = 0.75 ms. therefore, the value of phi is φ = (0.75/10) x 180; φ = 0.075 x 180; φ = 13.5°. the value of cos phi is cos phi = cos 13.5° = 0.972 6) phase current over phase voltage at 9° when the phase current precedes a phase voltage of 9°, the current and voltage waves can be seen in figure 23. square wave is in and out of ic 74ls74 at phase angle 9° as shown in figure 24. cos in time is converted to degrees before converted into cos phi to be known, as shown in figure 25. when the phase difference is 9°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse rises at 9.25 ms drops at 10 ms, the δt is δt = 10 9.5 = 0.5 ms. therefore, the value of phi is φ = (0.5/10) x 180; φ = 0.05 x 180; φ = 9°. the value of cos phi is cos phi = cos 9° = 0.987. 7) phase current over phase voltage at 4.5° when phase current precedes a phase voltage of 4.5°, the current and voltage waves can be seen in figure 26. square wave is in and out of ic 74ls74 at phase angle of 4.5° as shown in figure 27. cos in time is converted to degrees before converted to cos phi, as shown in figure 28. when the phase difference is 4.5°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse is up at 39.75 ms and down figure 20. current phase precedes a voltage of 13.5°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm-324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 23. the phase current precedes a voltage of 9°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm-324; (3 and 4) square wave of lm-324 ic output to ic 74ls86 figure 21. wave input and wave output ic 74ls86 at phase angle 13.5º. (1) current-phase currents; (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 24. wave input and output ic 74ls86 at phase angle 9º. (1) current-phase currents; (2) square wave phase voltage; (3) square wave difference of phase current and voltage figure 22. square wave as an indicator of phase difference at a different phase of 13.5°. (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time figure 25. square wave as an indicator of phase difference at different phase 9°. (1) current phase input waves to ic 74ls86; (2)°wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 35 is at 40 ms, the δt is δt = 40 39.75 = 0.25 ms. therefore, the value of phi is φ = (0.25 / 10) x 180; φ = 0.025 x 180; φ = 4.5°. the value of cos phi is cos phi = cos 4.5° = 0.996. 8) phase current over phase voltage at 0° when phase current precedes a phase voltage of 0°, the current and voltage waves can be seen in figure 29. square wave is in and out of ic 74ls74 at phase angle 0° as shown in figure 30. figure 31 shows a wave input and output ic 74ls86 at phase angle 0°. when the phase difference is 0°, the value of δt can be determined by measuring the output pulse ic 74ls74. when the pulse is up at 9.9 ms and drops at 9.9 ms, then δt is δt = 9.9 – 9.9 = 0 ms. therefore, the value of phi is φ = (0/10) x 180; φ = 0 x 180; φ = 0°. the value of cos phi is cos phi = cos 0° = 1. figure 32 shows the circuit and simulation of cos phi = 1. b. the correlation between phase shift, cos angle, and cos phi the correlation between the cos angle (degree) and cos phi can be seen in figure 33. from figure 33, it is found that the correlation between the phase difference in degrees and cos phi is inversely proportional; the greater the phase difference, the smaller the cos phi. this has a bad effect on the quality of the electrical power obtained by the customer. the correlation between the phase shift (time) and cos phi can be seen in figure 34. from figure 34, it is found that the correlation between the phase difference in time and cos phi is inversely proportional; the greater the phase difference the smaller the cos phi. this means that the greater the difference phase in time, the worse the quality of the electric power produced. figure 26. current phase precedes a voltage of 4.5°. (1 and 3) wave input current from source; (2 and 4): wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm324; (3 and 4) square wave of lm-324 ic output to ic 74ls86 figure 29. current phase precedes a voltage of 0°. (1 and 3) wave input current from source; (2 and 4) wave input voltage from source; (1 and 2) sine wave input current and voltage to ic lm-324; (3 and 4) square wave output of ic lm-324 to ic 74ls86 figure 27. wave input and output ic 74ls86 at phase angle 4.5°. (1)° current-phase currents; (2) square wave phase voltage; (3)°square wave difference of phase current and voltage figure 30. wave input and output ic 74ls86 at phase angle 0°. (1)°current-phase currents; (2) square wave phase voltage; (3)°square wave difference of phase current and voltage figure 28. square wave as an indicator of phase difference at different phase 4.5°. (1) current phase input waves to ic 74ls86; (2) wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time figure 31. square wave as an indicator of phase difference at different phase 0°. (1) current phase input waves to ic 74ls86; (2)°wave input of phase voltage to ic 74ls86; (3) wave output of ic 74ls86 as phase angle in time jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 36 iv. conclusion the amount of power factor or cos phi depends on the difference between the wavelength of the current wave to the voltage wave. the phase difference in time and angle is inversely proportional to cos phi. the longer the lag time between voltage wave and current wave, the smaller the cos phi. this, of course, because phi gets smaller away from 1. if cos phi is smaller than 1, then the power quality on the network is worse. this will certainly increase the costs to be paid on the customer side because it does not match the costs paid to the power used. for electric power providers, this will bring disadvantages, as the efficiency level of the generating power device will decrease. the novelty of this simulation circuit can be used as a trigger angle on scr trigger for dc motor speed control, for rocket launch angle adjuster, to measure the angle of inclination and other uses relating to angle adjustments. by connecting it to a microcontroller, this circuit can be used to perform various control switching, speed control, precision angle control, and others. acknowledgement the researcher would like to thank mr. royan who has collaborated in providing this simulation support software, mr. abdul syakur at the electrical power engineering laboratory, diponegoro university, semarang, indonesia. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could figure 32. circuit and simulation of the value cos phi = 1 figure 33. correlation between the cos angle (º) and cos phi figure 34. correlation between the phase shift (time) and cos phi 0 5 10 15 20 25 30 35 1 2 3 4 5 6 7 8 angle (degree) cos phi 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 1 2 3 4 5 6 7 8 phase shift (time) cos phi jumrianto and royan / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 28-37 37 have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] k. wirtayasa, p. irasari, m. kasim, p. widiyanto, and m. f. hikmawan, "load characteristic analysis of a double-side internal coreless stator axial flux pmg," j. mechatronics, electr. power, veh. technol., vol. 10, no. 1, p. 17, 2019. [2] m. z. efendi, n. a. windarko, and m. f. amir, “"design and implementation of battery charger with power factor correction using sepic converter and full-bridge dc-dc converter," j. mechatronics, electr. power, veh. technol., vol. 4, no. 2, p. 75, 2013. [3] d. d. and s. w. laurent jenck, "power factor correction (pfc) handbook," hbd853/d r. 2011. [4] k. dewi, s. rapi, m. naim, and e. u. sari, "zero crossing implementation in control unit for nuvoton-based illumination measurement of incandescent lamps and fans," in proceedings of the electrical & information engineering seminar,. november, pp. 320–326, 2016. [5] edward ong, "using the performance and reliability advantages of zero crossing," pp. 5–7, 2017. [6] a. g. ekayana and a. a. ratna rakasiwi, "power supply safety design based on zero crossing detector in computer laboratory,"” j. technol. vocat. educ., vol. 15, no. 1, pp. 10–19, 2018. [7] m. vorobyov and k. vitols, "low-cost voltage zero-crossing detector for ac-grid applications,"” electr. control commun. eng., vol. 6, no. 1, pp. 32–37, 2014. [8] christian de godzinsky, "diy isolated high quality mains voltage zero crossing detector," july, pp. 10–12, 2007. [9] r. g. hermawan, "measuring power and power factor," uksw salatiga-final project, 2013. [10] a. kay and t. claycomb, "ti designs – precision : verified design comparator with hysteresis reference design,". texas instruments, may 2013, pp. 1–23, 2014. [11] t. a. yahya chusna, indhana sudiharto, "improvement of power factor for household load automatically," 2011. [12] t. instrument, "data sheet lm124-n / lm224-n / lm324-n / lm2902-n low power quad operational amplifiers," may, 2004. [13] r. e. corporation, "data sheet hd74ls86 quadruple 2-input exclusive-or gates," electronics, pp. 1–7, 2010. [14] a. p. lalit madhab dhal, "study and analysis of different types of comparators," institute of technology, rourkela, 2013. [15] s. peele, "understanding power factor and how it affects your electric bill," presented by progress energy, 2011. [16] g. m. masters, "renewable and efficient electric power systems. handbook," wiley interscience, 2004. [17] o. hydro, "power factor: energy management series," republished by: cos phi inc. 2011. [18] l. stastny, r. mego, l. franek, and z. bradac, "zero cross detection using phase locked loop," ifac-papersonline, vol. 49, no. 25, pp. 294–298, 2016. [19] a. r. anish.k, rakesh bute, "zero crossing detector using 741 ic,"2014.[online].available:http://www.circuitstoday.com/zer o-crossing-detector. [20] a. richardson, "an-1210 zero crossing detector," silego technology, santa clara, california, 2018. [21] r. w. wall, "simple methods for detecting zero crossing," iecon proc. (industrial electron. conf., vol. 3, pp. 2477–2481, 2003. https://mev.lipi.go.id/ https://doi.org/10.14203/j.mev.2019.v10.17-23 https://doi.org/10.14203/j.mev.2019.v10.17-23 https://doi.org/10.14203/j.mev.2019.v10.17-23 https://doi.org/10.14203/j.mev.2019.v10.17-23 https://doi.org/10.14203/j.mev.2013.v4.75-80 https://doi.org/10.14203/j.mev.2013.v4.75-80 https://doi.org/10.14203/j.mev.2013.v4.75-80 https://doi.org/10.14203/j.mev.2013.v4.75-80 https://doi.org/10.14203/j.mev.2013.v4.75-80 https://bit.ly/3wqy8bt https://bit.ly/3wqy8bt https://bit.ly/3ybjjo8 https://bit.ly/3ybjjo8 https://bit.ly/3ybjjo8 https://bit.ly/3ybjjo8 https://bit.ly/3ybjjo8 https://bit.ly/2urdfei https://bit.ly/2urdfei http://dx.doi.org/10.23887/jptk-undiksha.v15i1.12668 http://dx.doi.org/10.23887/jptk-undiksha.v15i1.12668 http://dx.doi.org/10.23887/jptk-undiksha.v15i1.12668 http://dx.doi.org/10.23887/jptk-undiksha.v15i1.12668 http://dx.doi.org/10.2478/ecce-2014-0015 http://dx.doi.org/10.2478/ecce-2014-0015 http://dx.doi.org/10.2478/ecce-2014-0015 https://bit.ly/3dstsgs https://bit.ly/3dstsgs https://bit.ly/2uyq7ek https://bit.ly/2uyq7ek https://bit.ly/3hqwvbp https://bit.ly/3hqwvbp https://bit.ly/3hqwvbp https://bit.ly/2uaegfu https://bit.ly/2uaegfu https://bit.ly/3xps6vj https://bit.ly/3xps6vj https://bit.ly/3xps6vj https://www.renesas.com/sg/en/document/dst/hd74ls86-datasheet?r=527086 https://www.renesas.com/sg/en/document/dst/hd74ls86-datasheet?r=527086 https://bit.ly/3jue8h5 https://bit.ly/3jue8h5 https://bit.ly/3r25a0i https://bit.ly/3r25a0i http://dx.doi.org/10.1002/0471668826 http://dx.doi.org/10.1002/0471668826 http://dx.doi.org/10.1007/springerreference_215457 http://dx.doi.org/10.1007/springerreference_215457 http://dx.doi.org/10.1016/j.ifacol.2016.12.050 http://dx.doi.org/10.1016/j.ifacol.2016.12.050 http://dx.doi.org/10.1016/j.ifacol.2016.12.050 https://bit.ly/3yexg4l https://bit.ly/3yexg4l https://bit.ly/3yexg4l https://bit.ly/3afvnwn https://bit.ly/3afvnwn http://dx.doi.org/10.1109/iecon.2003.1280634 http://dx.doi.org/10.1109/iecon.2003.1280634 http://dx.doi.org/10.1109/iecon.2003.1280634 i. introduction ii. materials and methods a. comparator b. exclusive-or logic gates (ex-or) c. power factor d. zero-rrossing detector e. isis proteus simulation software f. simulation set-up 1) design a differential phase detector (zero-crossing detector) 2) set the input current phase 3) running the simulation 4) displays digital oscilloscope 5) convert the phi value to cos phi iii. results and discussions a. phase current analysis over phase voltage 1) phase current precedes phase voltage at 31.5 2) phase current precedes phase voltage at 27 3) phase current over phase voltage at 22.5 4) phase current over phase voltage at 18 5) phase current over phase voltage at 13.5 6) phase current over phase voltage at 9 7) phase current over phase voltage at 4.5 8) phase current over phase voltage at 0 b. the correlation between phase shift, cos angle, and cos phi iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.10-17 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis ahmad fudholi a, b, *, mariyam fazleena musthafa c, goh li jin a, rudi darussalam b, ahmad rajani b, andri setiawan b, anwar b, mohammad hossein yazdi d, hazim moria e,mohd yusof othman a, mohd hafidz ruslan a, kamaruzzaman sopian a a solar energy research institute, universiti kebangsaan malaysia bangi selangor, 43600, malaysia b research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komp lipi bandung, jl. sangkuriang, west java, 40135, indonesia c department of energy, ministry of environment green building, handhuvaree hingun, maafannu, male', 20392, republic of maldives d dept. of electric power generation stations, network and supply systems, institute of engineering and technology, south ural state university 76, lenin avenue, chelyabinsk, 454080, russian federation e department of mechanical engineering technology, yanbu industrial college yanbu al-sinaiyah city, 41912, kingdom of saudi arabia received 21 february 2021; accepted 09 june 2021; published online 31 july 2021 abstract solar energy is a renewable energy that can produce heat via a thermal system and generate electricity via a photovoltaic (pv) module. a photovoltaic-thermal (pvt) collector is a system that has a pv module combined with a thermal collector system. the pvt collector is a popular technology for harvesting solar energy. a pvt collector can generate both electrical and thermal energies simultaneously. the study aims to validate the pv and outlet temperature for various mass flow rates and solar radiation. to develop a predictive model, a steady-state energy analysis of a pvt air collector was performed. an energy balance equation was solved using the matrix inversion method. the theoretical model was developed and validated against the experimental results, which have a similar trend and are consistent with the experimental results. on the other hand, the validated model was used to study the performances of pvt air collectors using exergy analysis for the mass flow rate ranging from 0.007 kg/s to 0.07 kg/s and solar radiation ranging from 385 w/m2 to 820 w/m2. the result from the mathematical model was found to be consistent with the experimental data with an accuracy of about 95 %. the average pvt exergy efficiency was found to be 12.7 % and 12.0 % for the theoretical and experimental studies, respectively. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: mathematical model; thermal efficiency; electrical efficiency; second law efficiency. i. introduction global crisis on primary energy sources, such as coils and gas, has facilitated the study of renewable energy technologies. studies have focused on solar energy to address the global crisis on oil and gas prices worldwide. sustainable energy sources, such as solar energy, are clean energy that contributes a substantial proportion to fulfilling the energy demand by societies. the yielding of solar energy for photovoltaic (pv) systems in energy technology can be broadly classified into two systems. pv energy system changes solar energy into electrical energy, and thermal energy system converts solar energy into thermal energy. the combination of pv and solar thermal collectors in the system can produce heat and electrical energy from solar energy. the use of a cooling system alongside pv system is validated as pvt system or pv with the cooling system. given the beneficial dual use of pvt compared with a single pv system, efficient use of solar energy may contribute to the demand for heat and electrical energy to be supplied to industries and societies [1][2]. pvt collector systems using air as heat transfer medium are known as pvt air collector systems. the * corresponding author. tel: +62-812-7519-3956 e-mail address: a.fudholi@gmail.com https://dx.doi.org/10.14203/j.mev.2021.v12.10-17 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.10-17 https://dx.doi.org/10.14203/j.mev.2021.v12.10-17 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.10-17&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 11 air circulation in the system is air circulating through the path between the back of the pv module surface with the system or path insulation on both sides of the pv module. air is streamed directly through natural convection or forcefully. the hot air that comes out of this system is useful for drying and heating purposes. this system is widely applied in two designs namely the pv system that is integrated with the solar thermal collector system and pv system that is integrated into the building ventilation system. the energy analysis of the pvt air collector has been carried out by researchers. the efficiency of energy analysis is usually determined regardless of the power loss factor for the system. therefore, over the past few years, most systems are analyzed and designed by taking into consideration the cost, the economy, the environment, and efficiency [3]. pvt collectors can attain net (electrical plus thermal) efficiencies of 70 % or more, depending on the conditions, with electrical efficiencies of 15 – 20 % and thermal efficiencies of more than 50 %. [4]. pvt technologies offer the ability to reduce the number of materials used, the time it takes to install, and the amount of space needed [5]. pvts are useful for household applications since they can generate both electricity and thermal energy at the same time. commercial pvt systems, despite their enormous potential, are still not as popular as stand-alone, individually installed pv and thermal systems [6][7]. exergy analysis is a measure of consistency in determining the value of the economy as mentioned by many researchers. through exergy analysis, the real efficiency value can be determined by determining the value of system power loss. consequently, if the energy efficiency value and the efficiency of the exertion are different, the energy efficiency is higher than the efficiency of the previously mentioned factor. exergy analysis is a very clever step in the design and process of the industry. this is because optimum energy consumption is an important issue. information from exogenous value is also very important in operating costs, energy recovery, diversity of fuels, and pollutants. now, exergy analysis is widely used in solar energy assessment such as solar drying systems, solar collectors, and pvt systems [8]. jadallah et al. [9] designed, fabricate, and modeled for double-pass pvt collectors for drying applications. in the diverse weather conditions, zoukit et al. [10] constructed and forecasted an indirect form of solar dryer that functions in both forced and natural convection modes. tiwari et al. [11] constructed and built a hybrid pvt air collection with a dryer, then assessed the system's thermal model. the dryer chamber performed better for crops in forced convection mode than in natural convection mode [11]. the indirect dryer was shown to be more efficient than an open solar dryer [12]. for drying pear, hajar et al. [13] designed an indirect solar drier method. the higher output temperature reached 57 °c when solar radiation was 900 w/m2, and the drying room's thermal efficiency was 11.11 % [13]. the loss of pv module efficiency is one of the most serious issues with a building-integrated photovoltaic (bipv) system. as the temperature of a pv panel rises by 1 °c from 25 °c, its efficiency drops by roughly 0.4 – 0.5 %. [14]. theoretical study and experimental validation of energetic performances of pvt air collectors were studied by touafek et al. [15]. the simulation results were compared to those obtained through experimentation from outdoor testing. their comparison reveals a high level of agreement. in the case of the intake and output fluid temperatures, this agreement is more pronounced. this study will derive the output temperature and the pv temperature from the mathematical model and validate them against an experiment from indoor testing. the study aims to validate the pv and outlet temperature for a mass flow rate of air ranging between 0.007 kg/s and 0.07 kg/s and solar radiation of 385 w/m2 and 820 w/m2. the validated data would then be used to analyze the exergy of pvt air collector and compare it with the exergy of the pvt used in the experiment. exergy analysis identifies the causes, locations, and magnitude of the inefficiencies of the system and provides an accurate measure of how a system approaches the ideal. ii. materials and methods a. mathematical modeling the cross-sectional view of the pvt air collector is shown in figure 1. various heat transfer coefficients are shown in the figure 1. the energy balance equation for pvt air collectors is based on the following assumptions: all convection heat transfer coefficients in the channels and flowing air are equal and constant; the usable heat gain to by air is uniform along the length of the collector; and the ohmic losses in the solar cell are insignificant [16]. figure 1 shows temperatures such as tp is pv temperature, ti is inlet temperature, tb is bottom temperature, tf is fluid (air) temperature, and to is outlet temperature. ut and ub are top and bottom loss coefficients. s is solar radiation, α, τ coefficients are absorption and transmission coefficient, respectively. heat transfer coefficient of radiation from pv to ambient (hrpa), heat transfer coefficient of radiation from pv to bottom (hrpb), and heat transfer coefficient of convection from pv to fluid (hcpf). the steady-state energy balance equations for pvt air collectors are given as follows: for pv, figure 1. schematic diagram of heat transfer coefficients in a pvt air collector a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 12 𝜏𝜏𝜏 = 𝑈𝑡�𝑇𝑝 − 𝑇𝑎� + ℎ𝑐𝑝𝑐�𝑇𝑝 − 𝑇𝑐� + ℎ𝑟𝑝𝑟�𝑇𝑝 − 𝑇𝑟� + 𝜂𝑃𝑃𝜏 (1) for the airflow channel, ( ) ( ) ( )o i cpf g f cbf b fmc t t h t t h t t− = − + − (2) for the backplate, ( ) ( ) ( )rpb p b cbf b f b b ah t t h t t u t t− = − + − (3) where t b t k u l = (4) 1 1 t w rpa u h h −   =   +  (5) ℎ𝑟𝑝𝑟 = 𝜎�𝑇𝑝+𝑇𝑏��𝑇𝑝2+𝑇𝑏 2� � 1 𝜀𝑝 + 1 𝜀𝑏 −1� (6) ( )( )2 2rpa p p sky p skyh t t t tε s= + − (7) 1.50.0522sky at t= (8) where pε , s , at , skyt , bt and pt are the emissivity of pv, stefan– boltzmann constant, ambient temperature, sky temperature, backplate temperature, and pv temperature, respectively. the convective heat transfer coefficients [16] are given as in equations (9) to (15). h k h nu d = (9) in which 𝐷ℎ = 4𝑊𝑊 2(𝑊+𝑊) (10) where w , d , and hd are the width, depth, and equivalence diameter of the channel, respectively; k is the air thermal conductivity, and; nu is the nusselt number [16]. nusselt numbers are given as follows [16]: for re<2300 (laminar flow region), 𝑁𝑁 = 5.4 + 0.00190�repr� 𝐷ℎ 𝐿 �� 1.71 1+0.00563�repr� 𝐷ℎ 𝐿 �� 1.17 (11) for 2300<re<6000 (transition flow region), ( ) 2 3 2 1 3 3 0.14 0.116 re 125 pr 1 h w d nu l µ µ     = − +         (12) for re>6000 (turbulent flow region), 0.8 0.40.018 re prnu = (13) where re and pr stand for reynolds and prandtl numbers, given as [16] re h ch md a µ = (14) pr c k µ = (15) for a short collector of less than 10 m, the theoretical model assumes that the mean air temperature is equal to the arithmetic mean [16], where ( ) 2 i o f t t t + = (16) the physical properties of air are density, specific heat, thermal conductivity, and viscosity as published. the major design parameters are given as w = 0.53 m, l = 1.2 m, ta = ti = 27 oc, εp = 0.7, τ = 0.92, εb = 0.9, α = 0.9, and v = 1 m/s [16]. for simplicity, equations (1) to (3) can be presented in a 3 × 3 matrix form: [ ][ ] [ ]a t b= (17) 1 2 3 4 5 6 cpf rpb p cpf cbf f rpb cbf b z h h t z h z h t z h h z t z  − −          =                (18) where 1 t cpf rpbz u h h= + + (19) 2 t a pz s u t sat η= + − (20) ( )3 2cpf cbfz h h mc= − + + (21) 4 2 iz mct= − (22) ( )5 cbf rpb bz h h u= − + + (23) 6 b az u t= − . (24) the temperature vector can be calculated using the matrix inversion form, as shown in equation (17) [ ] [ ] [ ]1t a b−= . (25) the first and second laws of thermodynamics are used to conduct exergy analysis, which includes taking into account total exergy intake, exergy outflow, and exergy destructed from the system. the general exergy balance is expressed as [16][17]: if the effects related to kinetic and potential energy changes are ignored: i o dex ex ex− =∑ ∑ ∑ (26) or ( )i th pv dex ex ex ex− + =∑ ∑ ∑ , (27) in which 4 4 1 1 3 3 a a i s s t t ex ans t t       = − +        (28) ( ) 273 1 273 a th o i o t ex mc t t t  + = − −  +  (29) a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 13 pv pex asη= . (30) pvt air collectors' electrical efficiency can be computed as ( )0 1 0.0045 25p ptη η  = − −  (31) the overall performance of the system is evaluated using the total efficiencies, known as overall efficiency or pvt efficiency (ɳpvt) and can be expressed as pvt th pvex ex ex= + (32) where thex is the thermal exergy, pvex is the pv exergy, pvtex is the pvt exergy, oex is the output exergy, iex is the input exergy (radiation exergy), dex is the exergy destroyed, a is the pv area, n is the pv number, s is the solar radiation, st is the solar temperature ( st =5777k), at is the ambient temperature, ,o it t , and pt are the outlet, inlet, and pv temperatures, respectively. the pvt exergy efficiency is expressed as , o ex pvt i ex ex η = (33) b. experimental study this pv has been tested by the manufacturer in the industry under the radiation intensity of 1000 w/m2 and room temperature of 25 °c to achieve a maximum power of 80 w. the pvt air collector was evaluated using a specially constructed solar simulator in the laboratory, as shown in figure 2 and figure 3. the solar simulator was made using 23 halogen bulbs, each rated at 500 w, as seen in figures 2 and 3. the solar simulator's brightness and solar radiation were controlled using regulators. the tests were carried out with five different mass flow rates (0.007 kg/s to 0.07 kg/s) and solar radiations of 385 w/m2 and 820 w/m2. the air velocity reading range was 0.2 to 40 m/s, with an accuracy of 1 % of the reading 1 digit and a precision of 0.01 m/s. it was decided to utilize an eppley pyranometer since it is simple to operate and does not require the usage of a sun tracking equipment. this pyranometer was intended to be able to detect 90 % or more of all solar radiation data on the world. the constants for the eppley pyranometer used in this study were 11.99 × 10-6 v/wm-2. the thermocouples temperature range for j-type is 0 °c – 760 °c which was suitable with the multimeter used. materials used in the experiment were shown in table 1. data were recorded to calculate electrical and thermal efficiencies. iii. results and discussions the efficiencies of pvt air collectors were obtained. the temperature distribution of pvt air figure 2. photograph of pvt air collector under solar simulator figure 3. schematic of pvt air collector under solar simulator table 1. material used in the experiment no. material number function 1 sharp ne-80e2ea polycrystaline 80 w pv panel 1 generate electricity 2 500 w halogen lamp 23 supply of light and thermal radiation 3 350 w (yuhchang) fan 1 cooling the pv 4 air heater (500 w halogen lamp) 2 heating the inlet air 5 2000 va voltage regulator 6 changing power halogen lights 6 2000 va voltage regulator changing wind velocity of the fan 7 500 va voltage regulator 1 changing the heating power of the air 8 insulation prevent air out 9 pyranometer 1 to observe solar radiation 10 j-type thermocouples detect heat to a certain point 11 switches (such as switch fan) connection to 10 thermocouples 12 air duct 1 connect solar collector with fan 13 dta 4000 anemometer detecting the velocity of the wind 14 52 k/j thermometer multimeter 2 pointing temperature readings from thermocouples 15 72-7740 multimeter (connect to the pyranometer) 1 to detect the radiation intensity a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 14 collectors was determined using the mathematical model's. the result shows that by lowering the temperatures tp, tf, and tb simultaneously, the mass flow rate increases, as shown in figure 4 and figure 5. since can be seen in figures 4 and 5, raising the mass flow rate simultaneously decreased the temperatures (tp and to) of the pvt collector for both solar radiations, as more and more air volume is available to remove heat from the channel walls, lowering pv temperature. because the air velocity in the channel is increased, the outlet air temperature decreases as the air flow rate rises [18]. this is because air has less time inside the channel to reach higher outlet temperatures. for the pvt which received solar radiation of 820 w/m2, output air temperature and pv temperature presents higher values (figure 5) than the pvt which received solar radiation of 385 w/m2 (figure 4). the reason for this observation is due to more irradiance intercepted by the pvt collector hence more heat energy is transferred to the pv. this leads the pv to attain a higher temperature and allows more heat energy to be transferred to the airflow in the channel increasing the output temperature [19]. table 2 shows the results of pv and the outlet temperature of the pvt air collector. the average errors in the calculation of the outlet and pv temperature were 6.3 % and 5.1 % for s = 385 w/m2, and 3.8 % and 5.7 % for s = 820 w/m2, respectively. the mathematical model made reasonable forecasts for outlet and pv temperatures, with average errors of 5.0 % and 5.4 %, respectively. the mathematical model's outputs are 95 % and 94.6 % accurate, respectively, when compared to experimental data for outlet and pv temperatures. figure 6 and figure 7 show the exergy analysis of pvt air collectors. pvt exergy efficiency is in a similar trend and rises very slowly for both experimental and theoretical studies, which produced pvt exergy efficiencies of 11.5 % to 12.9 %. for solar radiation of 385 w/m2 in the theoretical study, the pvt air collector produced a pvt exergy of 28.6 w to 29.3 w with electrical exergy of 26.8 w to 28 w and thermal exergy of 1.2 w to 1.9 w. for solar radiation of 385 w/m2 in the experimental study, the pvt air collector produced a pvt exergy of 27.8 w to figure 4. mathematical model and experimental result of pvt air collectors for solar radiation of 385 w/m2 figure 5. mathematical model and experimental result of pvt air collectors for solar radiation of 820 w/m2 25 30 35 40 45 50 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 te m p er at u re ( o c ) mass flow rate (kg/s) theoretical pv temperature experimental pv temperature theoretical outlet temperature experimental outlet temperature theoretical back plate temperature 30 35 40 45 50 55 60 65 70 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 te m p er at u re ( o c ) mass flow rate (kg/s) theoretical pv temperature experimental pv temperature theoretical outlet temperature experimental outlet temperature theoretical back plate temperature table 2. comparison of theoretical and experimental studies for outlet and pv temperatures of pvt air collectors m (kg/s) s (w/m2) outlet temperature (°c) pv temperature (°c) theoretical experimental % error theoretical experimental % error 0.00696 385 35.9 32.2 11.5 45.3 46.5 2.6 820 45.8 41.4 10.6 64.4 66.0 2.5 0.02492 385 31.8 29.9 6.4 40.6 43.5 6.7 820 37.2 35.9 3.6 55.2 58.5 6.0 0.03861 385 30.4 29.4 3.4 39.8 41.4 3.9 820 34.1 33.4 2.2 53.6 56.1 4.7 0.05387 385 29.7 28.4 4.6 38.4 40.6 5.4 820 32.8 32.3 1.5 50.7 54.7 7.9 0.06958 385 29.3 27.8 5.6 37.3 40.1 7.0 820 31.9 31.6 0.9 48.5 52.2 7.6 average 5.0 5.4 a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 15 29.1 w with electrical exergy of 26.6 w to 27.6 w and thermal exergy of 0.3 w to 1.7 w. referring to figure 7, for solar radiation of 820 w/m2, the pvt air collector produced a pvt exergy of 58.7 w to 62.3 w with a thermal exergy of 5.5 – 8.4 w and an electrical exergy of 51 – 56.1 w for the theoretical study, and a pvt exergy of 55.5 – 58.7 w with thermal exergy of 0.9 – 5.9 w and electrical exergy of 50.4 – 53.7 w for the experimental study. table 3 shows the errors for exergy efficiencies of pvt air collectors. the variations of pv exergies with mass flow rate are shown in figure 8 and figure 9. the pv exergy of pvt air collectors increases with increasing air mass flow rate. a comparison of exergy efficiencies of pvt figure 8. electrical exergy versus mass flow rate for 385 w/m2 figure 9. electrical exergy versus mass flow rate for 820 w/m2 26.5 27.0 27.5 28.0 28.5 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 e le ct ri ca l e xe rg y (w ) mass flow rate (kg/s) theoretical experimental 50 51 52 53 54 55 56 57 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 e le ct ri ca l e xe rg y (w ) mass flow rate (kg/s) theoretical experimental figure 6. variations of exergies and exergy efficiency with mass flow rate for 385 w/m2 figure 7. variations of exergies and exergy efficiency with mass flow rate for 820 w/m2 0 5 10 15 20 25 30 35 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 e xe rg y, e ff ic ie n cy ( w , % ) mass flow rate (kg/s) electrical exergy theoretical thermal exergy theoretical pvt exergy theoretical pvt exergy efficiency theoretical 0 10 20 30 40 50 60 70 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 e xe rg y, e ff ic ie n cy ( w , % ) mass flow rate (kg/s) electrical exergy theoretical thermal exergy theoretical pvt exergy theoretical pvt exergy efficiency theoretical pvt exergy efficiency experimental thermal exergy experimental table 3. error for exergy efficiencies of pvt air collectors based on figures 6 and 7 m (kg/s) s (w/m2) pvt exergy efficiency (%) pv exergy efficiency (%) theoretical experimental % error theoretical experimental % error 0.00696 385 12.56 12.18 3.0 10.96 10.88 0.7 820 12.10 11.46 5.2 9.77 9.67 1.0 0.02492 385 12.91 12.33 4.5 11.25 11.07 1.6 820 12.84 12.11 5.7 10.34 10.14 2.0 0.03861 385 12.79 12.76 0.2 11.30 11.20 0.9 820 12.53 11.44 8.7 10.44 10.29 1.5 0.05387 385 12.80 12.53 2.1 11.38 11.25 1.2 820 12.64 11.46 9.3 10.62 10.37 2.3 0.06958 385 12.84 12.26 4.5 11.45 11.28 1.5 820 12.69 11.51 9.3 10.76 10.53 2.1 average 5.3 1.5 a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 16 air collectors is presented in table 4. figures 8 and 9 show the results for electrical exergy or exergy of pv, 𝐸𝑥𝑃𝑃 obtained from the mathematical model (theoretical) and experimental results. figure 8 shows the variation of electrical exergy for pvt air collectors at a solar intensity of 385 w/m2. figure 9 shows the variation of electrical exergy for pvt air collectors at a solar intensity of 820 w/m2. for solar radiation of 385 w/m2, the pvt air collector produced electrical exergy of 26.8 w to 28 w in the theoretical study and 26.6 w to 27.6 w in the experimental study. for the case of solar radiation of 820 w/m2, the pvt air collector produced electrical exergy of 51 w to 56.1 w in the theoretical study and 50.4 w to 53.7 w in the experimental study. from figures 8 and 9, the results indicate that by increasing the mass flow rate there is a clear increase in the electrical exergy (𝐸𝑥𝑃𝑃) of the pvt collector for both the solar radiations. the likely reason for this observation is due to the decline in the pv temperature when mass flow air of the air increased. this decrease in the pv temperature increased the pv efficiency, mainly because a lower cell temperature increases the voltage significantly (even though it decreases current by a very small amount). for this reason, since the pv efficiency increases, the total useful electrical gain also increased. the results also show that the total electrical exergy (𝐸𝑥𝑃𝑃) of the pvt collector for the pvt which received solar radiation of 820 w/m2 presents higher values (figure 9) than the pvt which received solar radiation of 385 w/m2 (figure 8). the greater number of photons associated with higher solar irradiation creates more electron– hole pairs and thus more current in the pv cell, which is the most likely explanation for this result. the pv packing factor, or the percentage of absorber area occupied by pv cells, has a big impact on electrical production. the electrical output per unit collector area increases as the packing factor rises. iv. conclusion exergy analysis was used to analyze the performance of pvt air collectors in both theoretical and experimental study. the mathematical model matches the experimental data with an accuracy of around 95 %. the average pvt exergy efficiency in the theoretical and experimental studies is 12.7 % and 12.0 %, respectively. for the theoretical and experimental study, the average pvt exergy is 45.1 w and 42.3 w, respectively, with pv exergies of 40.9 w and 40.2 w and thermal exergies of 4.2 w and 2.1 w. acknowledgement the authors would like to thank the ministry of higher education malaysia for funding (frgs/1/2014/st02/ukm/03/1), as well as the solar energy research institute (seri), ukm for providing laboratory facilities and technical support. declarations author contribution all authors contributed equally as the main contributor to this study. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] s. abdul-ganiyu, d.a. quansah, e.w. ramde, r. seidu, and m.y. adaramola,, "investigation of solar photovoltaic-thermal (pvt) and solar photovoltaic (pv) performance: a case study in ghana,". energies, vol. 13, pp. 1-17, 2020. [2] n. boulfaf, j. chaoufi, a. ghafiri, and a. elorf, "thermal study of hybrid photovoltaic thermal(pv-t) solar air collector using finite element method," international journal of renewable energy research, vol. 6, no. 1, pp. 171-182, 2016. [3] s.s.s. baljit, h. y. chan, and k. sopian, "review of building integrated applications of photovoltaic and solar thermal systems,". journal cleaner production,. vol. 137, pp. 677–689, 2016. [4] i. guarracino, c.n. markides, a. mellor, and n.j. ekins-daukes, "dynamic coupled thermal and electrical modelling of sheet and tube hybrid photovoltaic/thermal (pvt) collectors,". applied thermal engineering, vol. 101, pp. 778–795, 2016. [5] c. good, "environmental impact assessment of hybrid photovoltaic-thermal (pv/t) systems, a review," renewewable and sustainable energy reviews, vol. 55, pp. 234–239, 2016. [6] m. fuentes, m. vivar, j. de la casa, and j. aguilera," an experimental comparison between commercial hybrid pv-t and simple pv systems intended for bipv," renewewable and sustainable energy reviews, vol. 93, pp. 110–120, 2018. [7] i. guarracino, j. freeman, a. ramos, s.a. kalogirou, n.j. ekinsdaukes, and c.n. markides, "systematic testing of hybrid pvthermal (pvt) solar collectors in steady state and dynamic table 4. comparison of the exergy efficiencies of pvt air collectors results pvt exergy efficiency (%) reference theoretical experimental theo.: ηpv=10 %, ηth=17.2 % 10.75 11.5 [20] theo.: ηpv=14-15 % 12-15 10.6 [21] n.a. 13.5 6.4 [22] theo.: ηpv=9.77-11.45 % exp.: ηpv=9.67-11.28 % 12.10-12.91 11.44-12.84 present study https://mev.lipi.go.id/ https://doi.org/10.3390/en13112701 https://doi.org/10.3390/en13112701 https://doi.org/10.3390/en13112701 https://doi.org/10.3390/en13112701 https://www.ijrer.org/ijrer/index.php/ijrer/article/view/3294/pdf_1 https://www.ijrer.org/ijrer/index.php/ijrer/article/view/3294/pdf_1 https://www.ijrer.org/ijrer/index.php/ijrer/article/view/3294/pdf_1 https://www.ijrer.org/ijrer/index.php/ijrer/article/view/3294/pdf_1 https://doi.org/10.1016/j.jclepro.2016.07.150 https://doi.org/10.1016/j.jclepro.2016.07.150 https://doi.org/10.1016/j.jclepro.2016.07.150 https://doi.org/10.1016/j.jclepro.2016.07.150 https://doi.org/10.1016/j.applthermaleng.2016.02.056 https://doi.org/10.1016/j.applthermaleng.2016.02.056 https://doi.org/10.1016/j.applthermaleng.2016.02.056 https://doi.org/10.1016/j.applthermaleng.2016.02.056 https://doi.org/10.1016/j.rser.2015.10.156 https://doi.org/10.1016/j.rser.2015.10.156 https://doi.org/10.1016/j.rser.2015.10.156 https://doi.org/10.1016/j.rser.2018.05.021 https://doi.org/10.1016/j.rser.2018.05.021 https://doi.org/10.1016/j.rser.2018.05.021 https://doi.org/10.1016/j.rser.2018.05.021 https://doi.org/10.1016/j.apenergy.2018.12.049 https://doi.org/10.1016/j.apenergy.2018.12.049 https://doi.org/10.1016/j.apenergy.2018.12.049 a. fudholi et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 10-17 17 outdoor conditions," applied energy, vol. 240, pp. 1014–1030, 2019. [8] a. fudholi, m. zohri, n.s.b. rukman, n.s. nazri, m. mustapha, c.h. yen, m. mohammad, and k. sopian, "exergy and sustainability index of photovoltaic thermal (pvt) air collector: a theoretical and experimental study," renewable and sustainable energy reviews, vol. 100, pp. 44-51, 2019. [9] a.a. jadallah, m.k. alsaadi, s.a. hussein. the hybrid photovoltaic-thermal double-pass solar system for drying applications. iop conf. series: materials science and engineering vol. 765 no. 012024, 2020. [10] a. zoukit, hicham el ferouali, issam salhi, said doubabi, and naji abdenouri, "takagi sugeno fuzzy modeling applied to an indirect solar dryer operated in both natural and forced convection," renewable energy, vol. 133, pp 849-860, 2019. [11] s. tiwari, sanjay agrawal, and g.n. tiwari, "pvt air collector integrated greenhouse dryers," renewable and sustainable energy reviews, vol. 90, pp. 142–159, 2018. [12] c.k.k. sekyere, f.k. forson, and f.w. adam, "experimental investigation of the drying characteristics of a mixed-mode natural convection solar crop dryer with back up heater," renewable energy, vol. 92, pp. 532-542, 2016. [13] e. hajar, t. rachid, and b.m. najib," conception of a solar air collector for an indirect solar dryer. pear drying test," energy procedia, vol. 141, pp. 29–33, 2017. [14] jin-hee kim, sang-myung kim, and jun-tae kim, "experimental performance of an advanced air-type photovoltaic/thermal (pvt) collector with direct expansion air handling unit (ahu)," sustainability, vol. 13 no. 888, pp. 1-10, 2021. [15] k. touafek, a. khelifa, l. boutina, i. tabel, and s. haddad "theoretical study and experimental validation of energetic performances of photovoltaic/thermal air collector," international journal of photoenergy, pp. 1-10, 2018. [16] a. fudholi, m. zohri, g. l. jin, a. ibrahim, c. h. yen, m. y. othman, m. h. ruslan, and k. sopian, "energy and exergy analyses of photovoltaic thermal collector with ∇-groove," solar energy, vol. 159, pp. 742-750, 2018. [17] a. fudholi, k. sopian, m. h. yazdi, m. h. ruslan, a. ibrahim, and h. a. kazem, "performance analysis of photovoltaic thermal (pvt) water collectors, energy conversion and management, vol. 78, pp. 641–651, 2014. [18] j.k. tonui, and y. tripanagnostopoulos, "air-cooled pv/t solar collectors with low cost performance improvements," solar energy, vol. 81, no. 4, pp. 498–511, 2007. [19] j.k. tonui, and y. tripanagnostopoulos, "performance improvement of pv/t solar collectors with natural air flow operation," solar energy, vol. 82, no. 1, pp. 1–12, 2008. [20] f. sarhaddi, s. farahat, h. ajam, and a. behzadmehr, "exergetic performance assessment of a solar photovoltaic thermal (pv/t) air collector, "energy and buildings, vol. 42, no. 11, pp. 2184– 2199, 2010. [21] a. s. joshi and a. tiwari, "energy and exergy efficiencies of a hybrid photovoltaic-thermal (pv/t) air collector," renewable energy," vol. 32, no. 13pp. 2223–2241, 2007. [22] m. bosanac, b. sørensen, i. katic, h. sørensen, b. nielsen, and j. badran, "photovoltaic/ thermal solar collectors and their potential in denmark", denmark, 2003. https://doi.org/10.1016/j.apenergy.2018.12.049 https://doi.org/10.1016/j.apenergy.2018.12.049 https://doi.org/10.1016/j.rser.2018.10.019 https://doi.org/10.1016/j.rser.2018.10.019 https://doi.org/10.1016/j.rser.2018.10.019 https://doi.org/10.1016/j.rser.2018.10.019 https://doi.org/10.1016/j.rser.2018.10.019 https://doi.org/10.1088/1757-899x/765/1/012024 https://doi.org/10.1088/1757-899x/765/1/012024 https://doi.org/10.1088/1757-899x/765/1/012024 https://doi.org/10.1088/1757-899x/765/1/012024 https://doi.org/10.1016/j.renene.2018.10.082 https://doi.org/10.1016/j.renene.2018.10.082 https://doi.org/10.1016/j.renene.2018.10.082 https://doi.org/10.1016/j.renene.2018.10.082 https://doi.org/10.1016/j.rser.2018.03.043 https://doi.org/10.1016/j.rser.2018.03.043 https://doi.org/10.1016/j.rser.2018.03.043 https://doi.org/10.1016/j.renene.2016.02.020 https://doi.org/10.1016/j.renene.2016.02.020 https://doi.org/10.1016/j.renene.2016.02.020 https://doi.org/10.1016/j.renene.2016.02.020 https://doi.org/10.1016/j.egypro.2017.11.114 https://doi.org/10.1016/j.egypro.2017.11.114 https://doi.org/10.1016/j.egypro.2017.11.114 https://doi.org/10.3390/su13020888 https://doi.org/10.3390/su13020888 https://doi.org/10.3390/su13020888 https://doi.org/10.3390/su13020888 https://doi.org/10.3390/su13020888 https://doi.org/10.1155/2018/2794068 https://doi.org/10.1155/2018/2794068 https://doi.org/10.1155/2018/2794068 https://doi.org/10.1155/2018/2794068 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.solener.2006.08.002 https://doi.org/10.1016/j.solener.2006.08.002 https://doi.org/10.1016/j.solener.2006.08.002 https://doi.org/10.1016/j.solener.2007.06.004 https://doi.org/10.1016/j.solener.2007.06.004 https://doi.org/10.1016/j.solener.2007.06.004 https://doi.org/10.1016/j.enbuild.2010.07.011 https://doi.org/10.1016/j.enbuild.2010.07.011 https://doi.org/10.1016/j.enbuild.2010.07.011 https://doi.org/10.1016/j.enbuild.2010.07.011 https://doi.org/10.1016/j.renene.2006.11.013 https://doi.org/10.1016/j.renene.2006.11.013 https://doi.org/10.1016/j.renene.2006.11.013 https://www.yumpu.com/en/document/read/4467325/photovoltaic-thermal-solar-collectors-and-their-potential-in-denmark https://www.yumpu.com/en/document/read/4467325/photovoltaic-thermal-solar-collectors-and-their-potential-in-denmark https://www.yumpu.com/en/document/read/4467325/photovoltaic-thermal-solar-collectors-and-their-potential-in-denmark introduction ii. materials and methods a. mathematical modeling b. experimental study iii. results and discussions conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.110-116 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis hartono yudo a, *, wilma amiruddin a, ari wibawa budi santosa a, ocid mursid a, tri admono b a department of naval architecture, faculty of engineering, diponegoro university jl. prof. sudarto no.13, semarang, 50275, indonesia b research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi jl. sangkuriang, building 20, 2nd floor, bandung, west java, 40135, indonesia received 5 september 2021; accepted 9 november 2021; published online 31 december 2021 abstract buckling and collapse are important failure modes for laying and operating conditions in a subsea position. the pipe will be subjected to various kinds of loads, i.e., bending moment, external pressure, and tension. nonlinear finite element analysis was used to analyze the buckling strength of the pipe under pure bending and external pressure. the buckling of elastic and elastoplastic materials was also studied in this work. the buckling strength due to external pressure had decreased and become constant on the long pipe when the length-to-diameter ratio (l/d) was increased. the non-dimensional parameter (β), which is proportionate to (d/t) (σy/e), is used to study the yielding influence on the buckling strength of pipe under combined bending and external pressure loading. the interaction curves of the buckling strength of pipe were obtained, with various the diameter-to-thickness ratio (d/t) under combination loads of external pressure and bending moment. for straight pipes l/d = 2.5 to 40, d = 1000 to 4000 mm, and d/t = 50 to 200 were set. the curved pipes d/t = 200, l/d =2.5 to 30 have been investigated by changing the radius of curvature-to-diameter ratio (r/d) from 50 to ∞, for each one. with decreasing r/d, the buckling strength under external pressure decreases slightly. this is in contrast to the bending of a curved pipe. when the value of r/d was decreased, the flexibility of the pipe was increased. however, the buckling strength of the pipe during bending was decreased due to the oval deformation at the cross-section. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: buckling strength; elastic buckling; elasto-plastic buckling; bending moment; external pressure. i. introduction offshore pipelines will be subjected to a variety of loads, including bending moment, tension, internal pressure, and external pressure. the maximum permitted bending moment was calculated using a set of equations that included proposed safety factors for various safety levels [1]. the safety factor technique used ensures that the intended safety values are maintained consistently across all load combinations. a theoretical technique for predicting the moment rotation response of circular hollow steel tubes with various d/t ratios under pure bending has been proposed [2]. in deriving of the deformation energy, extensional deformation and rigid plastic material behavior were considered. previous study [3] shown that for a straight pipe with an l/d ranging from 5 to 20, and a d/t ranging from 50 to 200, the critical bending moment in a linear calculation is described by equation (1): 𝑀𝑐𝑐 = 0,666𝜋𝐸𝐸𝐸2 (1) where e, r, t, and mcr are the young’s modulus (mpa), radius of cylinder (mm), wall thickness (mm), and the critical bending moment (nmm), respectively. buckling is the sudden change in the shape of a structural component under load. it happens when a force presses on a slender structure and makes it collapse. under bending, the buckling strength of straight and curved pipes [4] was examined. equation (2) shows the maximum moment, mmax * corresponding author. tel: +62-896-2352-2161 e-mail address: hartono.yudo@yahoo.com https://dx.doi.org/10.14203/j.mev.2021.v12.110-116 https://dx.doi.org/10.14203/j.mev.2021.v12.110-116 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.110-116 https://dx.doi.org/10.14203/j.mev.2021.v12.110-116 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.110-116&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 111 (nmm), for a long perfect pipe with oval deformation: 𝑀𝑀𝑀𝑀 = 0,52𝑀𝑐𝑐 (2) in deep underwater pipes, the interplay of propagation buckling and lateral buckling has been investigated [5]. propagation buckling is a local mode that can swiftly spread and destroy a lengthy pipeline segment in deep water. in contrast, lateral buckling is a probable global buckling mode in long pipelines. a numerical analysis was carried out to simulate buckling contact in deep undersea pipelines. the buckling of pipes under external and internal pressures, both elastic and non-elastic, has been studied [6]. the buckling pressure of pipes due to external/internal pressures is evaluated using an analytical model. the results show that the initial ovality significantly influences bifurcation pressure. the buckling behavior of steel cylindrical shells (pipes, tubes, and pressure vessels) actuated by combining axial compression and external lateral pressure, which was studied using the generalized beam theory (gbt) [7]. there are comparisons made between experimental and numerical results. the empirical formula for buckling propagation pressure of offshore pipelines with various diameter-tothickness ratios and different strain hardening modulus and yield stress is proposed [8] based on experimental and comprehensive numerical data. finite element analysis (fea ) is used to evaluate the response of a pipe-in-pipe (pip) system to the combined effect of external pressure (on the outer pipe) and bending moment. the fe analysis is carried out on a pip system chosen from various offshore pipeline applications. it is demonstrated that the external pressure-induced reduction in bending moment capacity of pip systems is greater than that of the identical single outer system without an inner pipe [9]. a parametric analysis was done using the verified fe model, and two primary buckling propagation modes were detected a pipe with thin and moderately thin carrier pipes [10]. the nonlinear fe approach investigates the local buckling failure of the damaged subsea pipeline under combined stresses. the simulated results reveal that external pressure and axial force can significantly affect the pipeline's buckling behavior and bending capacity [11]. the case of pure bending moment is investigated, and it is discovered that increasing the initial denting displacement and the diameter-to-thickness ratio reduces the critical moment. the external pressure is then applied, and it is determined that when the pre-applied external pressure and the initial denting displacement grow, the nondimensionalized critical bending moment decreases. the collapse pressure would be reduced to some extent if the bending moment was supplied to the dented pipe before the external pressure [12]. the problem of pipeline collapse under point load, longitudinal bending, and external pressure was explored [13] using the rational model methodology and comparing anticipated results to previously published full-scale experimental data on the subject. the rational model methodology is recommended for design codes because of its rational derivation and high prediction capabilities. the phenomena identified in the literature and industry standards as a determinant in the evaluation of flexible pipes collapsing under combined bending and external pressure were investigated [14]. the final collapse pressure is calculated by combining dimensions fluctuations and ovalization due to bending. the results of the comparison of numerical and analytical predictions suggest that analytical methodologies can be used to predict the curve collapse of flexible pipes. the buckling behavior of long cylindrical steel shells under simultaneous bending and uniform peripheral pressure was examined in an experimental investigation [15]. in terms of bucking load and modes of deformation, the theoretical consequences predicted by nonlinear fea accord reasonably well with the experimental data. this paper studied nonlinear fe software used to calculate the buckling and collapse strength of straight and curved pipes under bending and external pressure, taking into account the effect of a cross-sectional oval deformation. ii. materials and methods a. calculation parameters for straight pipe, the length-to-diameter ratio (l/d) and the diameter-to-thickness ratio (d/t) are employed as calculating factors. the diameter changes from 1000 to 4000 mm, while the l/d ranges from 2.5 to 40. d/t might range from 50 to 200. where d is the pipe diameter in millimeters, t is the wall thickness in millimeters, and l is the pipe length in millimeters (mm). the pipe diameter is initially set to 4000 mm, and the thickness is set to 20 mm in the computation of a curved pipe. by varying the pipe length, l/d can range from 2.5 to 30. (r/d) fluctuates between 50 and 200. in a curved pipe, r is the radius of curvature (mm). b. model for computation and program for calculation in fea, full-length models of straight and curved pipes are used. calculations of nonlinear buckling of pipe under bending and external pressure are carried out. msc marc was utilized to do a nonlinear buckling study that included the cross-sectional oval deformation before to buckling. the element with four nodes in a quadrilateral (no. 75) is used. in a circumferential direction, the calculation region is divided into 36 components. in the case of a long cylinder, the element count is essentially 120, and more elements are used to keep the calculation accurate. c. boundary condition and loading condition as shown in figure 1, the (x, y, z) coordinates were used to connect the center of a circle and the points on a circle, and rigid body elements (rbe) are put at both ends of the section. the bending moment is loaded at the circle's center at both ends. the rigid h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 112 body elements (rbe) retain the section in-plane during rotational deformation caused by the bending moment and prevent oval deformation of both ends. tying or rbe can be used to create a rigid link in msc marc for little or significant deformations. as shown in figure 2, the external pressures are loaded uniformly at the surface of the pipe. iii. results and discussions a. the numerical results on nonlinear buckling strength of straight pipe under bending and external pressure when the pipe acts elastically, figure 3 depicts the correlations between non-dimensional pressure and pipe length. the non-dimensional pressure (p/pcr) is shown on the vertical axis, with the critical pressure stated in equation (3). the horizontal axis is length of pipe. 𝑃𝑐𝑐 = 𝐸′ 4 �𝑡 𝑐 � 3 (3) 𝐸′ = 𝐸 (1−ѵ2) where 𝐸′, v, and pcr are the young’s modulus (mpa), poisson ratio, and the critical external pressure (mpa), respectively. similarly, the buckling strength of a shorter pipe under external pressure is greater than that of a long pipe. the effect of limitation at both ends of a short pipe is greater than that of long pipes. with rising l/d, the buckling strength of straight pipe subjected to external pressure decreases until it reaches a constant value at the long pipe. when d/t lowers, the critical pressure rises. figure 1. mid span section & rbe at both end section figure 2. the external pressure is loaded uniformly at the surface of the pipe figure 3. relationship between non-dimensional pressure and l/d for straight pipe (d/t=50~200) by elastic analysis. h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 113 in elastic analysis, the moments pressure interaction stability for straight pipe is shown in figure 4. the non-dimensional pressure (p/pcr) is shown on the vertical axis, while the nondimensional moment (m/mcr1) is shown on the horizontal axis. as indicated in equation (1), mcr1 is the critical bending moment of a cylinder under axial compression. for every value of d/t, the interaction curve's tendency on buckling strength under combined bending and external pressure loading was the same. when the yield strength of the material is 621 mpa, the moments pressure interaction stability for straight pipe in elasto-plastic analysis is presented in figure 5. the numerical results on buckling strength of straight pipe under external pressure in elasto-plastic analysis occurred in the elastic zone. pipe with a big d/t value is more elastic than pipe with a small d/t value under combined bending and external pressure loading. the non-dimensional parameter (β) as stated in equation (4) is used to examine the yielding influence on the buckling strength of pipe under pure bending and external pressure. 𝛽 = (𝐷 𝑡 )(𝜎𝜎 𝐸 ) (4) where β and σy are non-dimensional parameter, and the yield stress (mpa), respectively. this parameter is determined by the linear buckling moment to initial yielding moment ratio. changes in yield stress and diameter are used to test the elasto-plastic buckling strength. in an elasto-plastic analysis, the momentspressure interaction stability for straight pipe is illustrated in figure 6. the lines with the hollow diamond, hollow circle, and hollow triangle markers represent the numerical results of d/t = 200, 100, 50, and y = 621, where β equals 0.6, 0.3, and 0.15 respectively. moreover, the solid diamond marker are the numerical results by d/t = 100 and σy = 1260, β equals 0.6. and then, for the solid circle and solid triangle maker are the numerical results by d/t = 200 and σy = 315 mpa and 157.5 mpa, where β equals 0.3 figure 4. moment-pressure interaction stability for straight pipe (l/d = 30) by elastic analysis figure 5. moment pressure interaction stability for straight pipe in elasto-plastic analysis h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 114 and 0.15. the pipe buckles elastically when the value of is large, and the pipe buckles elasto-plastically when the value of is small. b. the numerical studies on the nonlinear buckling strength of curved pipe under bending and external pressure according to elastic analysis, the relationship between non-dimensional pressure and l/d for curved pipe (d/t = 200) and r/d fluctuates between 50 and 200, as illustrated in figure 7. similarly, as the l/d increases, the buckling strength of a curved pipe decreases until it reaches a constant value on the long pipe. on a short pipe, the effects of limitation at both ends are considerable for a curved pipe under external pressure. however, for a curved pipe with the same d/t and a different r/d, the buckling strength values were nearly identical for each same l/d value, or the differences were not significant. this is in contrast to the bending of a curved pipe. when the value of r/d decreases, the flexibility of the pipe increases, but the buckling strength of the pipe during bending decreases due to the oval deformation at the cross-section. in elastic analysis, the moments pressure interaction stability for curved pipe is shown in figure 8. the nondimensional pressure (p/pcr) is shown on the vertical axis, while the non-dimensional moment (m/mcr1) is shown on the horizontal axis. with a lower r/d number, the buckling strength decreases. when the yield strength of the material is 621 mpa, as represented in figure 9, moments pressure interaction stability for curved pipe in elasto-plastic analysis. the pipe with a large r/d value is more elastic than the pipe with a small r/d value. when the value of r/d is large for curved pipe under combined loading of bending and external pressure, the pipe is undoubtedly more elastically than when the value of r/d is small. under external pressure, the buckling strength of a straight pipe is about the same for each d/t. the buckling strength under external pressure is slightly reduced with lowering r/d for a curved pipe, as shown in figure 7, with the same value of d/t and difference r/d. however, the disparity isn't significant. this is in contrast to the bending of a curved pipe. when the value of r/d decreases, flexibility increases, oval deformation at mid-span increases, and buckling strength decreases. figure 6. moment-pressure interaction stability for straight pipe in elasto-plastic analysis figure 7. relationship between non-dimensional pressure and l/d for curved pipe (d/t=200) by elastic analysis. h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 115 iv. conclusion the study of nonlinear fe software is used to calculate the buckling and collapse strength of straight and curved pipes under combined loads, such as bending and external pressure. the numerical computation clarifies the following. in elastic analysis, when l/d increases, the buckling strength decreases owing to external pressure and becomes constant on the long pipe. in the shorter pipe, the effect of limitation at both ends is greater than in the longer pipe. for straight pipe under external pressure, the buckling strength occurs on the elastic region. a pipe with a high d/t value is more elastic than a small d/t value under combined bending and external pressure loading. for every value of d/t, the tendency of the interaction curve on buckling strength for straight pipe under combined bending and external pressure was the same in elastic analysis. the non-dimensional parameter (β) is used to examine the yielding influence on pipe buckling strength. when a curved pipe has the same d/t value but a different r/d (where r/d ranges from 50 to ∞), the buckling strength under external pressure decreases slightly as r/d decreases. however, the disparity isn't significant. this is in contrast to the bending of a curved pipe. when the value of r/d decreases, the flexibility of the pipe increases, but the buckling strength of the pipe during bending decreases due to the oval deformation at the cross-section. figure 8. moment-pressure interaction stability for curved pipe in elastic analysis figure 9. moment-pressure interaction stability for curved pipe in elasto-plastic analysis h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 110-116 116 acknowledgment this research is supported by drpm kemenristek/brin indonesia. we are also immensely grateful to all researcher who is joined in this research. declarations author contribution hartono yudo and tri admono contributed as the main contributors of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] s. kyriakides and j. g.t., “bifurcation and localization instabilities in cylindrical shells under bending—i. experiments,” int. j. solids struct., vol. 29, no. 9, pp. 1117–1142, jan. 1992. [2] m. elchalakani, x. l. zhao, and r. h. grzebieta, “plastic mechanism analysis of circular tubes under pure bending,” int. j. mech. sci., vol. 44, no. 6, pp. 1117–1143, jun. 2002. [3] h. yudo and t. yoshikawa, “mechanical behaviour of pipe under pure bending load,” in proceedings of the 26th asian technical exchange and advisory meeting on marine structures, 2012, pp. 359–364. [4] h. yudo and t. yoshikawa, “buckling phenomenon for straight and curved pipe under pure bending,” j. mar. sci. technol., vol. 20, no. 1, pp. 94–103, 2015. [5] h. karampour, f. albermani, and m. veidt, “buckle interaction in deep subsea pipelines,” thin-walled struct., vol. 72, pp. 113–120, nov. 2013. [6] z. li, c. an, and m. duan, “an analytical approach for elastic and non-elastic buckling of pipes under external/internal pressures,” ocean eng., vol. 187, p. 106160, sep. 2019. [7] c. basaglia, d. camotim, and n. silvestre, “gbt-based buckling analysis of steel cylindrical shells under combinations of compression and external pressure,” thin-walled struct., vol. 144, p. 106274, nov. 2019. [8] s. gong, b. sun, s. bao, and y. bai, “buckle propagation of offshore pipelines under external pressure,” mar. struct., vol. 29, no. 1, pp. 115–130, dec. 2012. [9] a. binazir, h. karampour, b. p. gilbert, and h. guan, “bending capacity of pipe-in-pipe systems subjected to external pressure,” in acmsm25, springer, pp. 657–666, 2020. [10] m. alrsai, h. karampour, and f. albermani, “numerical study and parametric analysis of the propagation buckling behaviour of subsea pipe-in-pipe systems,” thin-walled struct., vol. 125, pp. 119–128, apr. 2018. [11] y. chen et al., “local buckling of dented subsea pipelines under the combined loadings,” asme 2020 39th international conference on ocean, offshore and arctic engineering. aug. 03, 2020. [12] s. yan, x. shen, h. ye, z. chen, x. he, and z. jin, “on the collapse failure of dented pipes under bending moment and external pressure,” in oceans 2016 mts/ieee monterey, pp. 1–5, 2016. [13] a.c. nogueira, “rationally modeling collapse due to bending and external pressure in pipelines,” earthquakes and structures, 3(3_4), pp. 473-494, 2012. [14] jr, w. c. loureiro and i.p. pasqualino, “numerical-analytical prediction of the collapse of flexible pipes under bending and external pressure,” international conference on offshore mechanics and arctic engineering, vol. 44908, pp. 353-359. american society of mechanical engineers, july 2012. [15] t. g. ghazijahani, and h. showkati, “experiments on cylindrical shells under pure bending and external pressure,” journal of constructional steel research, 88, pp. 109-122, 2013. https://mev.lipi.go.id/ https://doi.org/10.1016/0020-7683(92)90139-k https://doi.org/10.1016/0020-7683(92)90139-k https://doi.org/10.1016/0020-7683(92)90139-k https://doi.org/10.1016/s0020-7403(02)00017-6 https://doi.org/10.1016/s0020-7403(02)00017-6 https://doi.org/10.1016/s0020-7403(02)00017-6 https://www.researchgate.net/publication/357173491_mechanical_behaviour_of_pipe_under_pure_bending_load https://www.researchgate.net/publication/357173491_mechanical_behaviour_of_pipe_under_pure_bending_load https://www.researchgate.net/publication/357173491_mechanical_behaviour_of_pipe_under_pure_bending_load https://www.researchgate.net/publication/357173491_mechanical_behaviour_of_pipe_under_pure_bending_load https://doi.org/10.1007/s00773-014-0254-5 https://doi.org/10.1007/s00773-014-0254-5 https://doi.org/10.1007/s00773-014-0254-5 https://doi.org/10.1016/j.tws.2013.07.003 https://doi.org/10.1016/j.tws.2013.07.003 https://doi.org/10.1016/j.tws.2013.07.003 https://doi.org/10.1016/j.oceaneng.2019.106160 https://doi.org/10.1016/j.oceaneng.2019.106160 https://doi.org/10.1016/j.oceaneng.2019.106160 https://doi.org/10.1016/j.tws.2019.106274 https://doi.org/10.1016/j.tws.2019.106274 https://doi.org/10.1016/j.tws.2019.106274 https://doi.org/10.1016/j.tws.2019.106274 https://doi.org/10.1016/j.marstruc.2012.10.006 https://doi.org/10.1016/j.marstruc.2012.10.006 https://doi.org/10.1016/j.marstruc.2012.10.006 http://dx.doi.org/10.1007/978-981-13-7603-0_64 http://dx.doi.org/10.1007/978-981-13-7603-0_64 http://dx.doi.org/10.1007/978-981-13-7603-0_64 http://dx.doi.org/10.1016/j.tws.2018.01.019 http://dx.doi.org/10.1016/j.tws.2018.01.019 http://dx.doi.org/10.1016/j.tws.2018.01.019 http://dx.doi.org/10.1016/j.tws.2018.01.019 http://dx.doi.org/10.1115/omae2020-18737 http://dx.doi.org/10.1115/omae2020-18737 http://dx.doi.org/10.1115/omae2020-18737 http://dx.doi.org/10.1115/omae2020-18737 http://dx.doi.org/10.1109/oceans.2016.7761482 http://dx.doi.org/10.1109/oceans.2016.7761482 http://dx.doi.org/10.1109/oceans.2016.7761482 http://dx.doi.org/10.1109/oceans.2016.7761482 https://doi.org/10.12989/eas.2012.3.3_4.473 https://doi.org/10.12989/eas.2012.3.3_4.473 https://doi.org/10.12989/eas.2012.3.3_4.473 http://dx.doi.org/10.1115/omae2012-83476 http://dx.doi.org/10.1115/omae2012-83476 http://dx.doi.org/10.1115/omae2012-83476 http://dx.doi.org/10.1115/omae2012-83476 http://dx.doi.org/10.1115/omae2012-83476 https://doi.org/10.1016/j.jcsr.2013.04.009 https://doi.org/10.1016/j.jcsr.2013.04.009 https://doi.org/10.1016/j.jcsr.2013.04.009 i. introduction ii. materials and methods a. calculation parameters b. model for computation and program for calculation c. boundary condition and loading condition iii. results and discussions a. the numerical results on nonlinear buckling strength of straight pipe under bending and external pressure b. the numerical studies on the nonlinear buckling strength of curved pipe under bending and external pressure iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references microsoft word vol03_no1 mechatronics, electrical power, and vehicular technology 03 (2012) 31-38 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved design and implementation of anti-windup pi control on dc-dc bidirectional converter for hybrid vehicle applications perancangan dan implementasi kendali pi anti-windup pada konverter dc-dc dua arah untuk aplikasi kendaraan hibrid muh. zakiyullah romdlony a, amin a,b,* a sekolah teknik elektro dan informatika, institut teknologi bandung jl. ganesha 10, bandung, jawa barat 40132, indonesia b pusat penelitian tenaga listrik dan mekatronik – lipi komp. lipi bandung, jl. sangkuriang, gd. 10, lt. dasar, bandung, jawa barat 40135, indonesia received 10 may 2012; received in revised form 11 july 2012; accepted 12 july 2012 published online 31 july 2012 abstract well-regulated dc bus voltage is the important point to guarantee power demand fulfillment in hybrid vehicle applications. voltage regulation can be achieved with control method that determines switching signal on dc-dc converter. this paper describes the design and small scale experiment results of bus voltage regulation control for dc-dc bidirectional converter with battery and supercapacitor as energy sources. the control system consisted of two control loops. the outer loop got dc bus voltage feedback using anti-windup pi back calculation control method. this outer loop would generate a reference current for the inner loop that implemented hysteresis control. the inner control loop compared that reference curent with the source current obtained from the current sensor. simulation and experiment results showed that bus voltage was well-regulated under the load changes of 1% ripple voltage. key words: anti-windup pi, hysteresis, dc-dc bidirectional converter abstrak tegangan dc bus yang teregulasi dengan baik merupakan hal yang sangat penting pada aplikasi kendaraan hibrid, karena menjamin terpenuhi permintaan daya beban. regulasi tegangan dapat dicapai dengan menerapkan metode kendali tertentu yang akan menentukan sinyal penyaklaran pada konverter dc-dc. paper ini menjelaskan perancangan dan hasil eksperimen kendali regulasi tegangan bus pada konverter dc-dc dua arah (bidirectional converter) untuk skala kecil, dengan sumber berupa baterai dan superkapasitor. sistem kendali terdiri dari dua buah loop kendali. loop kendali luar mendapatkan umpan balik dari tegangan bus menerapkan metoda anti-windup pi back calculation. pengendali ini akan menghasilkan arus referensi untuk loop kendali dalam yang menerapkan kendali histeresis. loop kendali dalam membandingkan arus referensi tersebut dengan arus sumber yang diperoleh dari bacaan sensor arus. hasil simulasi dan eksperimen menunjukkan bahwa tegangan bus teregulasi dengan baik ketika terjadi perubahan beban dengan riak tegangan sekitar 1%. kata kunci: anti-windup pi, histeresis, konverter dc-dc dua arah. i. pendahuluan kebutuhan akan energi terus meningkat seiring berjalannya waktu. bahan bakar minyak masih menjadi pilihan utama bagi kebanyakan orang. pertumbuhan jumlah kendaraan yang sangat pesat tidak sebanding dengan jumlah bahan bakar minyak yang tersedia. jumlah kendaraan di dunia yang mencapai ratusan juta unit merupakan konsumen bahan bakar minyak terbesar yang membakar ratusan milyar galon bahan bakar tiap tahunnya. selain faktor ketersediaan bahan bakar minyak yang terbatas, faktor lingkungan juga menjadi isu yang sangat krusial. penggunaan bahan bakar minyak dapat menimbulkan polusi berupa gas buang co2 dan gas co yang berbahaya bagi manusia, dan juga dapat merusak lapisan ozon. * corresponding author. tel: +62-22-2503055 e-mail: amin_hwi@yahoo.co.id m.z. romdlony et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 31-38 32 penelitian dalam bidang energi hibrid untuk aplikasi kendaraan telah banyak dilakukan [1-6]. beberapa penelitian menggunakan baterai sebagai sumber energi utama dan dilakukan hibridisasi dengan penyimpan energi berupa superkapasitor [2], sedangkan lainnya menggunakan sel bahan bakar (fuel cell) sebagai sumber energi utama dan melakukan hibridisasi dengan baterai atau superkapasitor, atau keduanya [1,6]. pada prakteknya, nilai nominal tegangan dc dari sumber atau penyimpan energi tidak selalu sesuai dengan tegangan bus untuk aplikasi kendaraan hibrid yang secara umum memiliki standar 42 v [1,2,3]. oleh karena itu perlu penambahan rangkaian elektronika daya berupa konverter dc-dc untuk menyesuaikannya. tipe konverter dc-dc yang cocok digunakan adalah konverter dc-dc dua arah (bidirectional converter) atau sering dikenal dengan buck-boost converter. hal ini terjadi karena pada konverter tipe tersebut, arus dapat mengalir dua arah, dari arah sumber menuju beban, dan dari arah beban menuju sumber, sehingga ada mode discharging ketika daya mengalir dari sumber atau penyimpan energi ke beban, dan mode charging ketika daya mengalir dari beban ke penyimpan energi untuk mendapatkan energi regeneratif pada saat kendaraan hibrid melakukan pengereman atau perlambatan. selain itu, untuk menjamin permintaan daya beban terpenuhi, tegangan dc keluaran konverter dc-dc tersebut harus teregulasi dengan baik jika ada perubahan beban yang mendadak. regulasi tegangan dapat dilakukan dengan menerapkan metode kendali tertentu yang akan menghasilkan sinyal penyaklaran. pada makalah ini, kami menerapkan rancangan dua metode kendali yaitu pi antiwindup pada loop kendali luar, dan histeresis pada loop kendali dalam. perancangan kendali disimulasikan dengan matlab dan divalidasi dengan eksperimen skala kecil, dengan tegangan dc bus ditentukan sebesar 12 v. sumber energi yang digunakan berupa baterai 6 v dan superkapasitor dengan tegangan nominal 7,5 v. ii. kendali dc-dc bidirectional converter penggunaan konverter dc-dc diharapkan dapat menghasilkan tegangan keluaran yang tetap (sebagai regulator tegangan) sekalipun terdapat perubahan pada beban maupun pada sumber. ketika tegangan turun akibat beban berlebih, maka kendali pada konverter akan memberikan perintah pada sistem kendalinya untuk segera menaikkan tegangan keluarannya. begitu pula sebaliknya ketika terjadi beban nol dan tegangan menjadi terlalu besar, maka kendali pada konverter akan dengan segera menurunkan tegangan. oleh karena itu jarang digunakan suatu kendali terbuka dimana tidak ada umpan balik dari konverter [7]. salah satu teknik kendali yang telah umum adalah dengan teknik kendali faktor kerja secara langsung (direct duty cycle) seperti terlihat pada gambar 1. tegangan keluaran diumpanbalikkan dan dibandingkan dengan tegangan acuan setiap saatnya untuk dihasilkan galat (error) tegangan. sinyal galat ini kemudian diolah oleh pengendali sehingga dihasilkan sinyal pwm yang sesuai. metode kendali ini rentan terhadap gangguan karena respon lambat terhadap gangguan akibat perubahan input. selain itu, pengendali ini tidak mampu membatasi arus berlebih yang dapat terjadi [7]. metode kendali yang umum digunakan adalah penggunaan sebuah pengendali tegangan untuk menghasilkan arus referensi dan kemudian sebuah pengendali arus untuk menghasilkan sinyal penyaklaran (gambar 2). dengan skema seperti ini arus referensi yang dihasilkan oleh pengendali tegangan dapat dibatasi dan juga berarti membatasi arus pada konverter. oleh karena itu, dengan pengendalian ini maka tegangan keluaran konverter dapat dikendalikan tanpa mengalami kelebihan arus. a. kendali pi anti-windup pengendali tegangan yang umum digunakan adalah pengendali pi (proportional integral). pengendali ini berfungsi untuk mempercepat respon transien dan juga untuk memperbaiki galat keadaan tunak (steady state error). ∑ ∑ gambar 2. kendali konverter dengan penggunaan pengendali arus histeresis. gambar 1. kendali konverter dengan direct duty cycle. ∑ m.z. romdlony et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 31-38 33 secara umum komponen proporsional akan membuat respon sistem memiliki transien yang lebih cepat tetapi dapat menyebabkan sistem memasuki daerah osilasi bahkan daerah tidak stabil. nilai k dipilih dalam batas kestabilan sistem dan juga dalam pertimbangan implementasi pengendali. komponen integral memegang peranan dalam memperbaiki respon galat keadaan tunak. penambahan komponen integral yang terlalu besar akan mengakibatkan sistem cenderung mengalami osilasi. komponen integral akan menambah kutub pada sistem yaitu pada titik pusat. komponen integral ditunjukkan dengan konstanta waktu integrasi yaitu ti. semakin kecil nilai ti maka akan semakin cepat proses integral dilaksanakan. diagram blok pengendali pi ditunjukkan pada gambar 3 [8]. dalam penggunaan pengendali pi akan ditemukan hasil sinyal kendali u yang terlalu besar. hal ini biasanya terjadi ketika nilai dari ti terlalu kecil dan sinyal kendali menjadi membesar secara drastis. sistem yang dikendalikan akan memiliki aktuator tertentu. aktuator ini sendiri memiliki model dan batasan tersendiri dalam menerima sinyal kendali. sinyal kendali yang terlalu besar akan mengakibatkan kerusakan aktuator, sehingga untuk menghindari hal tersebut maka digunakan suatu penambahan komponen pada komponen integral yang dikenal dengan nama anti-windup [8]. anti-windup adalah algoritma penggunaan pengendali pi yang memperhitungkan batasan saturasi dan model dari aktuator. secara umum metode ini memiliki diagram blok seperti pada gambar 4. metode ini menggunakan sebuah aktuator model yang memiliki karakteristik linear maupun nonlinear dengan batasan umin dan umax. hal ini akan memberikan umpan balik pada pengendali integral sehingga pengendali integral akan mengurangi besarnya sinyal hasil integrasi. pengurangan besar galat yang diintegrasikan ini merupakan besaran selisih antara sinyal kendali hasil pi dan sinyal keluaran saturasi. jika sinyal keluaran pi melebihi saturasi maka sinyal ini akan dikalikan dengan suatu konstanta waktu tt yang akan memberikan umpan balik ke pengendali integral. penentuan nilai tt ini dipengaruhi oleh besarnya sinyal hasil keluaran pi yang diturunkan per satuan waktunya. dengan mendefinisikan: ; dan ; (1) penentuan nilai tt ini dapat diturunkan dari persamaan berikut dengan mengasumsikan x adalah nilai keluaran integrator [9]: . . – (2) . (3) . . 1 – . . . . (4) solusi persamaan (4) yang merupakan persamaan differensial pada nilai galat konstan adalah seperti persamaan (5) sampai (7): . . . . . (5) . . . . (6) (7) nilai x0  adalah nilai kondisi awal x, umax adalah nilai maksimum sinyal kendali yang boleh diberikan. jika dilihat dari persamaan diatas maka nilai u akan menuju nilai keadaan tunak. jika nilai kt semakin besar maka nilai tunak dari sinyal kendali akan semakin cepat dicapai. b. kendali histeresis untuk pengendali arus digunakan kendali histeresis karena kesederhanaan dan kemampuan pengendali ini. kendali arus dengan menggunakan histeresis ini memanfaatkan lebar sebuah pita histeresis dimana lebar pita ini merupakan batas atas dan bawah dari besarnya galat yang diperbolehkan. jika arus induktor naik dari batas bawah pita histeresis hingga batas atas maka saklar akan dimatikan dan jika arus ini turun dari batas atas menuju batas bawah maka saklar akan dinyalakan. hal ini berlaku untuk arus induktor yang positif sedangkan jika negatif hal berkebalikannya yang berlaku. gambar 4. pengendali pi dengan anti-windup. gambar 3. diagram blok pengendali pi. 34 gamba cara ker dilihat pada induktor, ya adalah leba referensi ya windup. pad diperoleh d (ripple) aru berikut ini a nilai lebar dengan bes oleh karen histeresis p induktor ya pita histere diturunkan penyalaan s . dengan il0 keadaan mu dengan ton pada sa induktornya . dengan tof dari dua pe dan (11), da ts sebesar   m.z. rom ar 5. kendali ar rja pengenda a gambar 5 ang tidak la ar pita hister ang dihasilka da aplikasi h dari persama s induktor de adalah persa setengah p sarnya seten na itu dalam perlu ditentu ang diizinkan esis dan frek dari hubung saklar seperti 0 merupaka ula. saat sakl . n adalah lama aat kondisi a memenuhi ff adalah lam ersamaan di apat memper mdlony et al. / me rus dengan pita ali arus hister 5. dengan il ain adalah ar resis, dan ir an oleh penge histeresis ini, aan hubunga engan lebar p amaan yang b pita histere ngah riak a m menentuk ukan besarn n. hubungan kuensi peny gan arus ind i persamaan an arus in lar s1 menya ; 0 a waktu sakla saklar s1 persamaan ; ma waktu s atas yaitu pe roleh periode echatronics, elect histeresis resis ini dap l adalah aru rus sumber, ref adalah aru endali pi ant arus indukto an antara ria pita histeresi berlaku. (8 sis ini sam arus indukto an lebar pit nya riak aru n antara leba aklaran dap duktor denga (9). (9 nduktor pad ala, berlaku (10 ar menyala. padam, aru (11 saklar padam ersamaan (10 e penyaklara trical power, and at us δ us tior ak is. 8) ma or. ta us ar at an 9) da 0) us 1) m. 0) an pers freku men oleh histe indu digu sem n pera konv besa resp resp hasi iii. a. r dipe dctrans konv atau laku mo kece s siny kend mo ajuk kend yang bus. refer dala terse baca men kend d vehicular techn samaan di uensi penya nggunakan k h besarnya eresis yang uktor dan se unakan, mak akin kecil. nilai frekue anan penting verter. nila arnya rugi-r pon pengend pon pengend l pengendali . desain bidirec desain kon rangkaian erlihatkan pa -dc dua a sistor daya y verter. sakla u igbt. d ukan, saklar sfet denga epatan penya saklar mosf yal penyakla dali yang dit sfet drive kan, terdiri d dali luar men g mendapatk pengendal rensi untuk l am akan m ebut dengan aan sensor a njadi sinyal p dali histeresi gambar 6. ran nology 03 (2012) atas mem aklaran fs pa kendali arus nilai induk digunakan. emakin lebar ka frekuens nsi penyakl g pada riak ai ini juga rugi saklar dali arus ini h dali tegangan yang tepat. n dan simu ctional c nverter dc-d konverter ada gambar arah terdapa yang akan m ar tersebut da dalam eksp r yang dig an pertimban aklaran (switc fet tersebu ran yang be terapkan me er. sistem dari dua bua nerapkan me kan umpan li ini akan loop kendali membanding arus sumber arus. galat a penyaklaran s sesuai deng ngkaian konver 31-38 mperlihatkan ada konverte histeresis d ktor dan le semakin be r pita histere si penyaklar laran ini m k arus dan a berpengaru akibat pen harus lebih c n untuk mem ulasi dc convert dc dua ara dc-dc du r 6. pada k at kompone mengubah mo apat berupa m perimen yan unakan ada ngan rating ching). ut akan di-dr erasal dari a lalui suatu r kendali yan ah loop kend etoda pi ant balik dari menghasilk dalam. loop gkan arus r yang diper arus ini aka dengan me gan gambar rter dc-dc dua (12) n bahwa r dengan itentukan ebar pita esar nilai esis yang ran akan memegang tegangan uh pada yaklaran. cepat dari mperoleh c-dc ter ah ua arah konverter en saklar ode kerja mosfet ng kami alah tipe daya dan drive oleh algoritma rangkaian ng kami dali, loop ti-windup tegangan kan arus p kendali referensi roleh dari an diubah nerapkan 2. a arah. persa averagen nilai par dc-dc b. sim sebel dilakuka nilai par dari has didapatk sebesar konstan selain diterapka dengan dengan dibatasi loop dala batas pi dengan adalah untuk ko 7 dipe digunaka diperliha pada bahwa t baik di referensi dari 11 o tabel 1 parameter paramete riak arus riak tegan vref l c fs vsumb i+ isumb m.z. amaan stat nya adalah se 0 rameter yang dua arah dip mulasi konv lum dilaku an terlebih ameter kend sil simulasi d kan nilai kp 90 agar did meskipun te n itu, m an adalah penguatan batas atas masing-mas am menerapk ita histeresis 0,1 a. kel berupa sin onverter dc erlihatkan r an untuk s atkan pada g hasil simul tegangan bu sekitar 12 inya meskip ohm menjad r konverter dcer ngan ber pengendali hy er gate vin+ dc-dc bidir conve gamba romdlony et al. / te space ebagai beriku g digunakan perlihatkan pa erter dc-dc ukan eksper dahulu untu dali (kp dan k dan tuning pa p sebesar 2 dapatkan teg rjadi perubah metode ant metode b kb ditentu dan bawah sing 4 a da kan kendali s adalah da luaran kenda yal penyak -dc dua ara rangkaian simulasi dan gambar 8. lasi pada ga us cukup te v sesuai d pun terjadi p di 6,3 ohm p -dc dua arah. nilai 5% 1% 12 v 400 μh 2000 μf 25 khz ysterisis pengendali pi metode ba vo+ vinvorectional erter beb (a) ar 7. rangkaian / mechatronics, e untuk m ut [5,10] 0 n pada konv ada tabel 1. c dua arah rimen, sim uk mendapa ki) yang opt arameter ken 25 dan nila gangan bus han beban. ti-windup back calcula ukan sebesa h sinyal ken an 0 a. ken histeresis de ri -0,1a sa ali histeresi klaran mos ah. pada gam simulink n hasil sim ambar 8, ter eregulasi de dengan tega perubahan b ada saat deti f v+vbu pi(s) anti windup dengan ack calculation ban n simulasi konve electrical power, model (13) verter h mulasi atkan imal. ndali, ai ki yang yang ation ar 2, ndali ndali engan mpai s ini sfet mbar yang mulasi rlihat engan angan beban ik ke 0 d n a p s d s i a d m d d m u d m c ta a c g te 12 vref v s 1 vref -v erter dc-dc du and vehicular t 0,5 kemudian detik ke 1. nilai arus yan a. sementar pada saat aru sekitar 1,25% dinaikkan, ri sekitar 0,7%. iv. desa a. desain e pengendal diimplementa merupakan in dengan pera dspace con motherboard untuk menge dsp yang memiliki pr clock 250 m ambahan b adalah spes controller bo • processo mhz dan • global m • flash m • 20 bit di slave ds • 4 adc 1 • 8 dac 1 gambar 8. ha egangan bus (at kp gain proporsional,k ki gain integral,kivbus ua arah (a), pen technology 03 (20 n kembali m perubahan b ng diminta b ra itu, untuk us beban 1 a %, sedangk iak tegangan ain dan h eksperimen li pi anti-w asikan pada ntegrasi anta angkat luna ntroller board d pc dan me endalikan ko digunakan rosesor bert mhz serta m ertipe tms sifikasi da ard : or tipe mpc n slave dsp memory 32 m memory 8 mb igital i/o dan sp 16 bit dan 4 a 16 bit asil simulasi k tas, hijau), arus (b 1 s integ kp gain back ca ngendali pi anti 012) 31-38 menjadi 11 oh beban ini m eban menjad k analisis ria a diperoleh ri kan ketika nnya berkura hasil eks windup yang platform ds ara perangka ak matla d ini diintegr enjadi penge onverter dcadalah ds tipe mpc82 memiliki pr s320f240. ari dspace c8240 denga tipe tms32 mb b n 14 bit digi adc 12 bit. konverter dc-d s beban (bawah, b). 1 s grator kb alcul ation,kb i-windup (b). 35 hm lagi pada menyebabkan di sekitar 1,9 ak tegangan, iak tegangan arus beban ang menjadi perimen g diusulkan space yang at keras dsp ab/simulink. rasikan pada endali utama -dc. modul s1104 yang 240 dengan rosesor dsp berikut ini e ds1104 an clock 250 20f240 ital i/o pada dc dua arah, , biru). 1 arus refer iref output li miter a n 9 , n n i n g p . a a l g n p i 4 0 a , rns m.z. romdlony et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 31-38 36 sistem perangkat lunak dspace ini memberikan kemudahan implementasi sistem kendali karena hanya menggunakan bantuan matlab/simulink tanpa harus melakukan proses pengkodean program secara manual (misalnya bahasa c) seperti layaknya modul dsp biasa. parameter-parameter dari sistem seperti tegangan/arus akan dibaca oleh konverter analog ke digital (adc) pada ds1104 controller board melalui rangkaian pengkondisi sinyal (signal conditioning). fungsi dari rangkaian pengkondisi sinyal ini adalah mengubah level tegangan/arus dari sistem agar sesuai dengan range input yang diijinkan oleh ds1104 controller board. proses perhitungan dari algoritma kendali akan dilakukan oleh ds1104 controller board dan akan menghasilkan sinyal penyaklaran. sinyal penyaklaran yang dihasilkan akan mengatur konverter dc-dc dua arah melalui pengkondisi sinyal dan driver mosfet. secara lengkap diagram blok implementasi sistem diperlihatkan pada gambar 9. algoritma kendali yang telah dirancang diuji dengan eksperimen. parameter kendali pi yang digunakan dalam eksperimen sama dengan parameter yang digunakan dalam simulasi. parameter ini dapat di-tuning secara online gambar 10. diagram simulink untuk implementasi pi antiwindup pada dspace real time controller. dengan mengaturnya pada gui realtime yang telah dibuat. akan tetapi untuk alasan keamanan, tuning parameter tidak dilakukan secara online. gambar 10 adalah diagram simulink yang diimplementasikan pada dspace controller board. seluruh proses perhitungan dan pengendalian sistem dilakukan secara real-time dan ditampilkan dalam antarmuka pada controldesk-dspace (gambar 11). controldesk-dspace dapat digunakan untuk mengamati semua parameter-parameter dari sistem seperti tegangan dan arus baterai/ superkapasitor, arus beban serta tegangan bus secara real-time melalui layar monitor komputer (gambar 12). b. hasil eksperimen sumber energi yang digunakan dalam eksperimen adalah baterai dan superkapasitor, sesuai dengan sumber energi yang biasa digunakan dalam aplikasi kendaraan hibrid. pengujian dilakukan dua kali, pertama pengujian konverter dc-dc dua arah dengan sumber berupa baterai. pengujian selanjutnya dilakukan dengan sumber berupa superkapasitor. spesifikasi sumber energi yang digunakan untuk eksperimen diperlihatkan pada tabel 2. tabel 2 spesifikasi sumber energi. sumber energi spesifikasi jumlah dan konfigurasi baterai (lead acid) 6v, 4.5 ah 1 buah superkapasitor 7.5v, 120 f 9 buah superkapasitor 2.5 v, 120 f (konfigurasi seri dan paralel) gambar 12. test bench eksperimen. sinyal_switching 10 scaling_dspace3 10 scaling_dspace2 10 scaling_dspace1 10 scaling_dspace 12 vref t egangan output (v) t egangan baterai (v) rt i data pi(s) pi anti windup back calculation 37.87 offset sensor arus1 37.87 offset sensor arus kendali hysterisis iref 2 gain sensor tegangan 15.15 gain sensor arus1 15.15 gain sensor arus 2 gain sensor tegangan dac ds1104dac_c2 adc ds1104adc_c8 adc ds1104adc_c7 adc ds1104adc_c6 adc ds1104adc_c5 arus beban (a) arus baterai (a) gambar 11. gui implementasi pi anti-windup. gambar 9. diagram blok implementasi sistem. gambar 1 dengan sum tegan eksperim yang di dengan p teganga masing m dan diak kemudia perangka pada gambar berupa sedangka sebesar terjadi p cara me menjadi sedangk superkap detik ke berda tersebut perubaha baik sesu dengan sumber e baterai superkapasi gambar konverter m.z. 3. hasil ekspe mber baterai. ngan bus ref men adalah terapkan pa parameter pe an bus dan melalui sens kuisisi oleh an di log, at lunak con hasil eksp 14) terlihat baterai terj an untuk sup 38%. perub pada detik ke engubah res 6,2 ohm, ke kan pada kon pasitor, peru 4 dan detik k asarkan ga dapat d an beban, teg uai dengan te riak tegang energi batera psc pbat tor b bidir 15. diagram dc-dc. romdlony et al. / erimen konvert ferensi yang 12 v. param ada tahap e engendali pad arus beban sor tegangan h adc dsp dan diplot ntroldesk. perimen (g bahwa untu jadi oversh perkapasitor bahan beban e 12 dan det istansi beba mudian men nverter denga ubahan beb ke 12. mbar 13 d disimpulkan gangan bus t egangan refe gan sekitar ai maupun su d boost converter rectional converter blok penguji / mechatronics, e ter dc-dc dua g diterapkan meter pengen eksperimen s da tahap sim dibaca ma n dan sensor pace. hasi dengan ban gambar 13 uk sumber en oot sekitar terjadi overs n pada konv tik ke 35 de an dari 11 njadi 11 ohm an sumber be ban terjadi dan gambar bahwa u teregulasi de erensi yaitu 1 1% baik u uperkapasitor dc bus beb ian bidireksion electrical power, a arah pada ndali sama mulasi. singarus l ini ntuan dan nergi 9% shoot verter engan ohm lagi. erupa pada r 14 untuk engan 12 v, untuk r. ban nalitas g d c d m g m b o s p d b s p m m b 0 g d and vehicular t gambar 14. ha dengan sumber c. pengujia pengujian dan discha memparalelk gambar 15. memberikan baterai dan d ohm menjadi superkapasito pengujian b diperlihatkan pada gam beban 11 ohm superkapasito pada saat beb maka superk menjaga tega dari hasil bus teregulas 0,7 % dan ov gambar 16. has dc. technology 03 (20 asil eksperimen superkapasitor. an bidireksio n konverter s arge) dila kan dua sum pengujian arus refere dilakukan pe i 4,3 ohm seh or (charging bidireksionali n pada gamb mbar 16 ter m maka bater or (superka ban menjadi kapasitor men angan bus tet eksperimen si dengan ba vershoot sebe sil pengujian bi 012) 31-38 n konverter dc . onalitas secara dua a kukan den mber energi dilakukan d ensi yang ko erubahan be hingga terlih atau dischar itas konver ar 16. rlihat bahwa rai menyupla apasitor cha i 4,3 ohm (d njadi discha tap pada refe n terlihat bahw aik dengan esar 24,87%. idireksionalitas 37 c-dc dua arah arah (charge ngan cara seperti pada dengan cara onstan pada eban dari 11 hat arah arus rging). hasil rter dc-dc a pada saat ai beban dan arging) dan detik ke 21) arging untuk erensinya. wa tegangan riak sebesar konverter dc h e a a a a s l c t n n ) k n r m.z. romdlony et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 31-38 38 v. kesimpulan hasil simulasi dan eksperimen menunjukkan bahwa dengan menggunakan metode kendali pi anti-windup, tegangan bus teregulasi dengan baik dengan riak tegangan sekitar 1% meskipun terjadi perubahan beban maupun perubahan tegangan sumber. hal ini berarti permintaan daya beban dapat terpenuhi dengan baik. untuk aplikasi daya besar seperti pada kendaraan hibrid, metode kendali ini dapat diaplikasikan dengan melakukan penyesuaian terutama pada spesifikasi hardware (dc-dc converter) yang digunakan. ucapan terima kasih penulis ingin mengucapkan terimakasih kepada tim hybrid fuel cell sekolah teknik elektro dan informatika itb dan juga kementerian riset dan teknologi atas pembiayaan yang diberikan untuk riset ini. referensi [1] thounthong, p., sethakul, p., raël, s., and davat, b., “control of fuel cell/battery/supercapacitor hybrid source for vehicle applications”, proceedings of the 2009 ieee international conference on industrial technology, 2009, pp.1-6. [2] thounthoung, p., chunkag, v., sethakul, p., davat, b., “comparative study of fuel cell vehicle hybridization with battery or supercapacitor storage device”, ieee transactions on vehicular technology, 58, pp. 3892-3904, 2009. [3] o. tremblay, “a generic battery model for the dynamic simulation of hybrid electric vehicle”, ieee vehicle power and propulsion conference, vppc 2007, pp. 284-289, 2007. [4] bizon n.,”some aspects on control of fuel cell hybrid source at the fuel cell maximum power point under dynamic load”, ijtpe journal, 2, pp. 63-68, 2010. [5] hajizadeh, a., aliakbar golkar m., “intelligent power management strategy of hybrid distributed generation system”, international journal of electrical power & energy system, 29, pp. 783–795, 2007. [6] souleman n.m., “a generic fuel cell model and experimental validation”, master thesis, ecole de technologie superieure universite du quebec, 2008. [7] sasongko, firman, “teknik kendali konverter dc-dc topologi baru mode boost”, laporan tugas akhir institut teknologi bandung, 2008. [8] astrom, karl johan, “control sistem design”, department of automatic control, lund institute of technology, sweden, 2002. [9] john, anirban ghoshal, and vinod, “antiwindup schemes for proportional integral and proportional resonant controller”, national power electronic conference, 2010, pp. 1-6. [10] hajizadeh a, aliakbar golkar m., “fuzzy control of fuel cell distributed generation systems”, iranian journal of electrical & electronic engineering, 13, pp. 31-41, 2007. microsoft word vol03_no1 mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved magnetic simulation and analysis of radial flux permanent magnet generator using finite element method simulasi dan analisis magnetik generator magnet permanen fluks radial menggunakan metoda elemen hingga pudji irasari a, hilman syaeful alam b, muhammad kasim a,* a pusat penelitian tenaga listrik dan mekatronik lipi kompleks lipi jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia b upt balai pengembangan instrumentasi lipi kompleks lipi jl sangkuriang, gd 30, bandung, jawa barat 40135, indonesia received 10 may 2012; received in revised form 14 june 2012; accepted 15 june 2012 published online 31 july 2012 abstract this paper discusses magnetic simulation and analysis of radial flux permanent magnet generator (pmg) using finite element method (fem) by utilizing open source software femm 4.2. the specification of generator is 25 v, 28 a, 3 phase, 300 rpm. the analyzed magnetic flux was in the air gap, stator teeth and slots to find out the distribusian pattern and its fluctuation. the simulations were conducted in no-load and nominal load (28 a) conditions. furthermore, the maximum flux density of simulation (bg(sim)) was used to calculate phase voltage eph to find out the magnitude of generated electromotive force (emf). the calculation results were presented as voltage vs. rotation graph in no-load condition and voltage vs. current graph in nominal load condition. both graphs were validated using eph from experiment result (eph(exp)) and eph whose bg value was obtained from analytical calculation (eph(calc)). the final results showed that in no-load condition, eph graph with bg(sim) (eph(sim)) was close to eph(exp) and eph(calc). the error rate with respect to the experiment was 6,9%. in nominal load condition, eph(sim) graph almost coincided with eph(calc.) graph, with the voltage drop of both was 0.441 v. both graphs however were far different from eph(exp) graph, which had 9 v of voltage drop. the overall results demonstrated that magnetic distribution pattern presented by fem was very helpful to avoid magnetic flux accumulation in a particular segment. besides, bg(sim) made the process to predict the value of eph become easier. key words: simulation, magnetic flux, generator, permanent magnet, finite element . abstrak dalam makalah ini dibahas simulasi dan analisis magnetik generator magnet permanen (gmp) fluks radial menggunakan metoda elemen hingga (meh) dengan perangkat lunak terbuka femm 4.2. generator memiliki spesifikasi 25 v, 28 a, 3 fasa, 333 rpm. fluks magnet yang dianalisis adalah pada celah udara, gigi dan alur stator untuk mengetahui pola distribusi dan fluktuasinya. simulasi dilakukan dalam keadaan tanpa beban dan dengan beban nominal (28 a). selanjutnya kerapatan fluks celah udara maksimum hasil simulasi (bg(sim)) digunakan untuk menghitung tegangan fasa eph guna mengetahui besarnya electromotive force (emf) yang dibangkitkan. hasil perhitungan ditampilkan berupa grafik tegangan vs. putaran untuk kondisi tanpa beban dan grafik tegangan vs. arus untuk kondisi beban nominal. kedua grafik tersebut divalidasi dengan eph hasil eksperimen (eph(exp)) dan eph yang nilai bg nya diperoleh dari perhitungan analisis (eph(calc)). hasil akhir menunjukkan bahwa dalam kondisi tanpa beban grafik eph dengan bg(sim) (eph(sim)) mendekati eph(exp) maupun eph(calc). tingkat kesalahan terhadap eksperimen sebesar 6,9%. untuk kondisi beban nominal, grafik eph(sim) hampir berimpit dengan eph(calc.), dengan tegangan jatuh keduanya sebesar 0,441 v. namun kedua grafik tersebut berbeda cukup jauh dengan grafik eph(exp) yang tegangan jatuhnya 9 v. dari keseluruhan hasil yang diperoleh menunjukkan bahwa pola distribusi magnet yang disajikan oleh meh sangat membantu untuk menghindari penumpukan fluks magnet pada segmen tertentu. selain itu bg(sim) sangat memudahkan dalam memprediksi besarnya eph. kata kunci: simulasi, fluks magnet, generator, magnet permanen, elemen hingga. * corresponding author. tel: +62-22-2503055 e-mail: kasime99uh@yahoo.co.id 24 i. penda analisis listrik dapa numerik. m dalam dua setiap titik dahulu se rangkaian kedua rangk yang sama metoda ana design tool sedangkan komponen elemen-elem medan ma elemen ters metoda num lebih akura dibuat sek memerlukan analisis mencegah dalam lami munculnya yang dilak diaplikasika dimensi m merupakan memperoleh dimensi sta menentukan magnet perm parameter-p back electro dengan e parameter h akurat (sam dalam m akan dilaku software f dianalisis ad yang merup konsentrasi fluks magn terhadap p (emf) baik dengan beb ii. met analisis menggunak metodologi pada gamb merupakan putus-putus hasil simul p. iras ahuluan medan ma at dilakukan metoda anal tahap, yang dalam me ehingga da magnetik. kaian terseb a seperti an alisis diangg untuk memp dalam meto mesin yang men kecil agnet dapat sebut. diban merik dapat at apabila p kecil mung n waktu yang medan mag terjadinya inasi inti ya konsentrasi kukan oleh an untuk o magnet da variabel h fluks magn atornya kon n parameter manen 500 w parameter ter omotive forc eksperimen hasil simulas ma dengan ha makalah ini ukan secara femm 4.2. dalah pada g pakan tempa fluks, pola net dalam g pembangkita k dalam kon an nominal. todolog medan kan open sou i penelitian bar 1. kotak proses se s adalah ha lasi pertama sari et al. / mecha n agnet dalam n secara ana lisis biasany g pertama ar sin diasums apat dipero selanjutnya but dianalisis nalisis rang ap lebih flek prediksi unju oda numerik dianalisis d (diskrit) d diketahui ndingkan me t memberika pembagian e kin tetapi g lebih lama gnet perlu dil saturasi me ang dapat m panas [3]. p ghita et.a optimasi geo an bukaan yang di net maksimu nstan. guo, kunci gene watt menggu rsebut adalah e dan indukt menunjuk si memberik sil eksperime i analisis m a numerik m kerapatan gigi stator da at-tempat kri a distribusi gmp serta an electrom ndisi tanpa b gi magnet urce software ini seperti dengan gari edangkan y asil simulas a berupa dist atronics, electric suatu mesi alisis ataupu ya dilakuka rah medan d sikan terlebi oleh sebua pada taha s dengan car gkaian listrik ksibel sebag uk kerja mesi k atau meh ibagi menjad dan besarny pada setia etoda analisi an hasil yan elemen dap metoda in [1, 2]. lakukan untu edan magn mengakibatka ada penelitia al [4] meh ometri gmp alur roto iolah untu um sementar y. et.al [5 erator sinkro unakan meh h fluks lilitan tansi. valida kkan bahw kan nilai yan en). medan magn menggunaka n fluks yan an celah udar itis terjadiny dan fluktua pengaruhny motive forc beban maupu dilakuka e femm 4.2 diperlihatka is tanpa putu yang bergar i/perhitungan tribusi meda al power, and ve in un an di ih ah ap ra k. ai in h, di ya ap is, ng at ni uk et an an h p. or uk ra 5] on h. n, asi wa ng et an ng ra ya asi ya ce un an 2. an us ris n. an gamb magn mag meli kedu pada adal udar tanp d udar disu fasa kelu nom diva eksp a. m soft kara gaya diha meli inti bany adal orie men men kan 0,5% dala deng mag gam dijag 2 t) mag sinu ehicular technolo bar 1. blok di net menggunaka gnet yang intang gener ua adalah g a gigi dan lah grafik fl ra. semua si pa beban dan dari grafik ra) diambil ubstitusikan untuk men uaran dalam minal. kedu alidasi deng perimen. material la material lam magnet ka akteristik ma a magnet m asilkan oleh m intasi kumpa tersebut [6] yak digunak lah silicon ste nted. keber ningkatkan nurunkan aru ndungan silik % – 3,25% [7 am prototip gan tebal 5 m gnetik dari l mbar 2 dim ga agar tidak ). apabila ni gnetisasi ak usoida dan m ogy 03 (2012) 23 iagram langkah an femm 4.2. ditampilkan rator. sedan grafik fluktu alur dan h uktuasi kera imulasi dilak beban nomi ketiga (ke nilai maks ke dalam ndapatkan g kondisi tan ua grafik t gan perhitu aminasi inti minasi inti b arena materi agnetnya ha misalnya m magnet perm aran yang m ]. material l kan dalam eel (baja sili radaan siliko volume us eddy dan m kon dalam b 7]. laminasi gmp adala mm, tipe 50 laminasi int ana fluks y k mencapai ti ilai tersebut d kan menyim engandung h -30 h-langkah anal n pada pe ngkan hasil uasi kerapat hasil simulas apatan fluks kukan dalam inal. erapatan fluk simumnya k persamaan grafik tegan npa beban da tersebut se ungan anali i biasa disebut ial ini menu anya apabila medan magn manen atau a mengelilingi laminasi yan mesin listr kon) jenis gr on dalam ba resistivitiy mengurangi baja silikon i inti yang d ah dari nipp h1300. kar ti diperlihatk yang menga itik saturasi ( dilampaui, m mpang dari harmonik [9] lisis medan nampang simulasi tan fluks si ketiga di celah m kondisi ks celah kemudian tegangan gan fasa an beban lanjutnya isis dan t dengan unjukkan a dikenai net yang arus yang laminasi ng paling rik putar rain-nonaja dapat untuk histerisis. kira-kira digunakan pon steel akteristik kan pada alir harus (kira-kira maka arus bentuk ]. p. irasari et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 25 gambar 2. kurva magnetik laminasi inti yang digunakan dalam gmp (50h1300) [8]. b. magnet permanen magnet permanen yang digunakan adalah ndfeb tipe n35 dengan karakteristik teknis dari pabrikan diperlihatkan pada tabel 1. karakteristik magnet yang diberikan oleh pabrikan (tabel 1) merupakan parameter masukan simulasi distribusi medan magnet. di antara dua parameter hc hanya salah satu yang akan dipilih. untuk menentukan yang mana parameter tersebut, digunakan bantuan kurva bh yang memperlihatkan kurva demagnetisasi magnet permanen (gambar 3). pada umumnya titik operasi magnet dapat bergerak naik turun sepanjang garis lurus yang disebut dengan demagnetizing characteristic dan kemiringannya adalah recoil permeability. tanpa adanya arus fasa yang mengalir dalam lilitan, titik operasi magnet berada pada open-circuit operating point. garis dari titik pusat menuju open-circuit operating point disebut load line. apabila ada arus yang mengalir dalam lilitan stator, medan magnet yang dibangkitkan oleh lilitan akan mendorong titik operasi menuruni lintasan karakteristik demagnetization, menekan kerapatan fluks celah udara sehingga besarnya kerapatan fluks celah udara turun di bawah opencircuit operating point atau nilai tanpa beban. apabila arus dihilangkan, titik operasi akan kembali menuju ke open circuit point. garis lurus yang menjadi lintasan operasi magnet disebut recoil line. perpotongan antara recoil line dengan sumbu h negatif diberi label hca, yaitu apparent coercivity, yang digunakan untuk perhitungan tabel 1 karakteristik magnet n35 [10]. parameter, simbol besaran satuan • kerapatan fluks remanensi, br 1220 mt • coercive force, hc o hcb 868 ka/m o hcj 955 ka/m • produk bh(maks.) 36 mgoe gambar 3. diagram skematik karakteristik b–h material magnet permanen [11]. rangkaian magnetik. sedangkan hc adalah actual coercivity [11]. untuk simulasi distribusi medan magnet dalam penelitian ini, nilai hc yang diambil adalah hcb (tabel 1) yang dalam gambar 2 identik dengan hca. sedangkan fluks remanensi br adalah kerapatan fluks maksimum yang dapat disimpan oleh magnet setelah menjalani proses magnetisasi hingga mencapai saturasi [12]. dimensi magnet adalah panjang × lebar × tebal (50,8 × 16 × 12) dalam satuan mm. 1) perhitungan medan magnet dengan metoda elemen hingga dalam kasus mesin-mesin listrik yang menggunakan laminasi inti dan memiliki frekuensi operasi yang relatif rendah maka arus eddy dalam laminasi inti dan perubahan kerapatan arusnya dapat diabaikan sehingga persamaan medan magnetostatiknya dapat diturunkan [13]. menurut hukum ampere dan persamaan maxwell, besarnya medan magnet dihitung menggunakan kerapatan arus sebagai masukan adalah [2]: ×h = j   (1) ·b = 0 (2) dimana h(x,y,z) = medan magnet dalam amper per meter, b(x,y,z) = kerapatan fluks magnet dalam tesla dan j(x,y,z) = kerapatan arus dalam amper per meter. hubungan antara kerapatan fluks magnet dan medan magnet dinyatakan dengan persamaan: b = μoμrh = × a (3) dimana μr (x,y,z) = permeabilitas relatif dan μo = permeabilitas udara = 4π10-7. untuk kasus dua dimensi (bidang datar): 0 0 , (4) 0 0 , (5) p. irasari et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 26 0 (6) 2) kerapatan fluks celah udara perhitungan kerapatan fluks celah udara digunakan sebagai validasi metoda elemen hingga untuk mendapatkan tegangan fasa baik dalam kondisi berbeban maupun tanpa beban. kerapatan fluks celah udara sangat dipengaruhi oleh dimensi stator dan magnet permanen. dalam rancangan ini stator diadopsi dari salah satu stator motor induksi standar yang ada di pasaran. besarnya kerapatan fluks celah udara bg(calc.) dihitung dengan persamaan (7-13) [2] [14]: . (7) carter coefficient kc, 1 1 (8) (9) leakage coefficient kml, 1 1 (10) permeance coefficient pc, · (11) flux concentration factor cφ, (12) α (13) parameter untuk menghitung kerapatan fluks celah udara ditampilkan pada tabel 2. 3) electromotive force (emf) besarnya kerapatan fluks magnet celah udara bg berpengaruh langsung pada besarnya emf yang dibangkitkan, sebagaimana dinyatakan dalam persamaan (14-16): tabel 2 parameter menghitung bg. parameter, simbol besaran satuan kerapatan fluks remanensi, br 1,2 t permeabilitas relatif magnet, µr 1,1 lebar alur stator, wss 0,00534 m kisar alur stator, τs 0,00859 m panjang radial celah udara, lg 0,001 m panjang radial magnet lm 0,012 m kisar kutub stator, τp 0.02576 m busur magnet,τm 0.01603 m 4,44 (14) fluks magnet (15) frekuensi · (16) dimana eph = tegangan fasa (volt), kw = faktor lilit = 1 (lilitan kisar penuh), ks = faktor kemiringan = 0,984, am = luas permukaan magnet = 1,62⋅10-3 m2, p = jumlah kutub = 18, n = putaran (rpm), nph = jumlah lilitan fasa = 90. nilai bg yang akan digunakan untuk menghitung persamaan (15) adalah bg(calc) dan bg hasil simulasi atau bg(sim). untuk kondisi berbeban, besarnya tegangan fasa keluaran dihitung pada kondisi nominal menggunakan persamaan [15]: ω ϕ ϕ (17) dengan l = 4,19 mh dan r = rg + rl = 0,1 + 0,029 = 0,129 ω, masing-masing adalah resistansi lilitan dan resistansi beban. c. tahapan simulasi distribusi fluks magnet dalam penelitian ini disimulasikan menggunakan software femm 4.2 dimana basis perhitungannya menggunakan persamaan maxwell. langkah-langkah umum simulasi diperlihatkan pada gambar 4. setiap langkah yang ditampilkan dalam gambar 4 (langkah 1 s.d 4) merupakan parameter masukan yang harus dipenuhi sebelum eksekusi simulasi dilakukan. karakteristik material yang diperlukan ditampilkan dalam tabel 3. pada tahap meshing, obyek yang diamati dibagi menjadi elemenelemen kecil berbentuk segitiga. kecepatan eksekusi simulasi sangat dipengaruhi oleh spesifikasi komputer yang digunakan. dalam penelitian ini waktu simulasi tergolong cepat karena objek yang diamati hanya dalam bentuk dua dimensi. tabel 3 parameter masukan simulasi magnetik menggunakan femm 4.2. komponen keterangan laminasi inti • kurva bh magnetik dipetakan dari gambar 1 • permeabilitas relatif, µr 4000 [2] magnet permanen • permeabilitas relatif, µr 1,1 [11] • gaya koersif, hc 868 ka/m [10] lilitan • jumlah lilitan fasa, nph 90 lilit • kerapatan arus, j 5 a/mm2 p. irasari et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 27 gambar 4. langkah-langkah utama simulasi distribusi medan magnet menggunakan femm 4.2. iii. hasil dan pembahasan pendefinisian jenis material gmp, arah magnetisasi dan hasil meshing diperlihatkan pada gambar 5. kutub magnet utara-selatan digambarkan dengan anak panah arah radial ke sisi luar dan sisi dalam. tiga buah lingkaran kecil di bagian tengah adalah lubang udara yang sekaligus berfungsi sebagai cooling system. jumlah konduktor per alur adalah 10 dengan diameter 1,0 mm. meshing dengan elemen terkecil 1 mm menghasilkan 43.424 nodes dan 86.517 elements. total waktu eksekusi simulasi yang diperlukan kira-kira 33 detik. hasil simulasi distribusi medan magnet tanpa beban dan dengan beban nominal 28 amper diperlihatkan pada gambar 6. besarnya kerapatan fluks maksimum tanpa beban yang tertulis dalam kotak data adalah 2,172 tesla. nilai tersebut turun menjadi 2,161 tesla pada kondisi beban nominal karena adanya fluks magnet lawan yang dibangkitkan oleh lilitan. pola distribusi menunjukkan bahwa rapat fluks yang tinggi terdapat pada gigi stator dan area tepat di bawah magnet permanen. namun demikian masih sulit untuk memastikan besarnya kerapatan fluks pada titik atau posisi tersebut. keterangan: 1. alur (terisi lilitan) 4. lubang udara rotor 2. stator 5. magnet permanen 3. poros 6. celah udara gambar 5. pendefinisian material dan meshing struktur gmp. informasi utama dari gambar 6 adalah bahwa pola distribusi tidak menunjukkan adanya penumpukan fluks magnet pada area tertentu yang dapat menimbulkan konsentrasi panas. untuk mendapatkan nilai rapat fluks pada alur dan gigi stator yang lebih terukur maka ditentukan boundary condition (kondisi batas) sebagaimana diperlihatkan pada gambar 7. kondisi batas dibuat agak panjang hingga mencakup beberapa alur dan gigi. hal ini dimaksudkan untuk mengetahui fluktuasi rapat fluks pada kedua area tersebut dan hasil simulasinya diperlihatkan pada gambar 8. gambar 8(a) menunjukkan bahwa rapat fluks tertinggi tanpa beban kira-kira 1,65 t terjadi pada gigi stator kemudian turun hingga hampir nol di dalam alur dan naik lagi kira-kira 0,6 t pada dua gigi stator berikutnya. pola tersebut dapat dibandingkan dengan gambar 6. rapat fluks (a) (b) gambar 6. distribusi medan magnet; (a) tanpa beban; (b) beban nominal. tentukan karakteristik material tentukan kondisi batas meshing (diskritisasi) hasil gambar geometri obyek p. irasari et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 28 gambar 7. kondisi batas pada celah udara dan gigi stator. maksimum terjadi saat gigi tepat menghadap bagian tengah kutub magnet. saat diberi beban nominal, rapat fluks maksimum turun menjadi kira-kira 1,25 t. meskipun material inti mampu dialiri fluks magnet dengan kerapatan hingga 2 t (gambar 2) namun dalam perancangan, nilainya dibatasi hingga 1,7 t (pada gigi stator) untuk menekan besarnya rugi inti [3]. pola rapat fluks celah udara diambil dengan menentukan kondisi batas sepanjang kira-kira 50 mm (gambar 7). hasil simulasi fluktuasi rapat fluks celah udara diperlihatkan pada gambar 9. fluks celah udara merupakan mutual fluks yang dibangkitkan oleh magnet permanen dan lilitan dalam alur. rapat fluks maksimum hasil simulasi (bg(sim)) tanpa beban besarnya kira-kira 0,94 t, terjadi ketika posisi magnet tepat di tengah gigi stator. adanya dua puncak lain dalam satu gelombang (di sisi kiri dan kanan puncak maksimum) sebagai akibat dari efek slotting [16]. fluks minimum terjadi tepat di tengah bukaan alur stator karena permeabilitas udara (4π10-7) lebih kecil dibanding permeabilitas laminasi inti (4000) (persamaan 3). bg(sim) selanjutnya disubstitusikan dalam persamaan (15) untuk mendapatkan tegangan fasa tanpa beban pada berbagai putaran atau frekuensi. untuk bg(calc) tanpa beban perhitungan analisis nilainya mengacu pada [11] yaitu sebesar 0,7-0,95 br. dengan mempertimbangkan adanya fluks bocor maka yang diambil adalah bg pada batas terkecil, yaitu 0,7br atau bg(calc) = 0,84 t. nilai tersebut selanjutnya disubstitusikan dalam persamaan (15). perbandingan tegangan fasa tanpa beban hasil perhitungan, simulasi dan eksperimen diperlihatkan pada gambar 10 dimana dapat dilihat bahwa grafik tegangan fasa tanpa beban yang paling mendekati hasil eksperimen adalah hasil perhitungan dengan bg(calc) = 0,7br. besarnya kesalahan (error) ratarata untuk masing-masing tegangan fasa adalah: eph(sim) 6,9% dan eph(calc) 4,47%. tegangan fasa berbeban dihitung pada kondisi nominal yaitu pada frekuensi 50 hz. besarnya bg(calc) dihitung menggunakan persamaan (7) diperoleh 0,84 t sedangkan bg(sim) diambil dari gambar 9(b) adalah 0,83 t. substitusi masing-masing nilai bg tersebut ke dalam persamaan (17) kemudian dibandingkan dengan hasil eksperimen diperlihatkan pada gambar 11. (a) (b) gambar 8. fluktuasi rapat fluks pada alur dan gigi stator; (a) tanpa beban; (b) beban nominal. (a) (b) gambar 9. hasil simulasi fluktuasi rapat fluks celah udara; (a) tanpa beban; (b) beban nominal. gambar 1 simulasi f deng sama ma grafik te berimpit cukup be apabila teganga v seda teganga kemungk yang s merupak kondisi dibandin baru dar dari permuka warnany masih b magnet mengelu gaya me magnet s gesekan rotor dil dua hal t dilakuka berkontr gaya m assembli gambar 1 kondisi n eksperime p. 0. perbandinga femm, perhitun gan nilai bg( aka dapat dil egangan yang t. terjadi per esar antara h dibandingk an jatuh eph(c angkan eks an jatuh eks kinan diseba sudah men kan kelema magnet ngkan dengan i pabrikan di gambar aan magnet ya tidak men baru. lapisa dari karat upas. hal ters ekanis yang d saat pemasan magnet den lepas untuk tersebut, gay an saat asse ribusi terhada mekanis tak ing rotor de 11. perbanding ominal hasil s en. irasari et al. / m an tegangan fas ngan dan ekspe (calc) dan bg(s lihat pada g g dihasilkan k rbedaan tega hasil perhitun kan denga calc) dan eph(sim sperimen m sperimen ya abkan oleh nurun, hal ahan dari permanen n kondisi ma iperlihatkan 12 dapat yang terpa gkilat sepert an nikelin y t hampir s sebut dapat t dikenakan la ngan ke dala ngan permuk kebutuhan p ya mekanis ta embling (g ap turunnya k langsung engan casing gan tegangan simulasi femm mechatronics, elec sa tanpa beban rimen. sim) yang ha gambar 11 ba keduanya ha angan jatuh ngan dan sim an eksperi m) kira-kira 0 mencapai 9 ang cukup b kualitas ma ini seka penelitian pada agnet yang m pada gamba dilihat ba asang pada ti saat kondis yang melind seluruhnya erjadi karena angsung terh am alur rotor kaan bidang penelitian. s ak langsung ambar 13) kualitas ma dilakukan g. gaya mek fasa berbeban m, perhitungan ctrical power, an n hasil ampir ahwa ampir yang mulasi men. 0,441 v. besar agnet aligus ini. rotor masih ar 12. ahwa rotor sinya dungi telah a: (1) hadap r, (2) saat elain yang juga agnet. saat kanis pada n dan g (b s s m d d k m k b ti [ i m te d n p e te y d 4 m s p k m g p nd vehicular tech (a) kete gambar 12. ko b) terpasang pa secara langs sering dilak menyebabkan dalamnya [1 dapat menyeb kondisi dim melintasi cel konversi ener baik memper idak terlalu c 5] [20] [21]. iv. kesim hasil sim magnet terdi erjadi konse dapat menim nominal (33 perbedaan n eph(exp) masin pada put egangan jatu yang relatif t demagnetisas 4.2 memudah magnet pada serta gigi dan paling bere konsentrasi f masih memi gambar 13. g permanen saat a hnology 03 (2012 erangan: a = m b = a ondisi magnet; ada rotor. sung maupu kukan terh n retak pad 17] [18]. k babkan terja mana fluks lah udara d rgi [19]. kon rlihatkan pe curam sebag mpulan mulasi memp istribusi sec entrasi fluks mbulkan ho 3 rpm) dan nilai eph(calc) ng-masing seb taran dan b uh eph(exp) m tajam kemun si. simulasi hkan dalam tiap segmen n alur stator y esiko terjad fluks. namun iliki kelema gaya mekanis assembling . a b 2) 23-30 magnet permane alur rotor (a) masih baru un tak lang hadap mag da bagian lu kerusakan fi adinya fluks magnet t dan berkontr ndisi magnet enurunan teg gaimana dala perlihatkan b cara merata pada area te ot spot. pa n kondisi ta ) dan eph(s besar 4,47% beban nom menunjukkan ngkinan dise menggunak analisis fluk n, terutama yang merupa di penump n demikian, ahan karena tak langsung 29 (b) en u dari pabrikan; gsung yang gnet dapat uar maupun sik tersebut bocor, yaitu tidak dapat ribusi dalam t yang masih gangan yang m penelitian bahwa fluks atau tidak ertentu yang ada putaran anpa beban, im) terhadap dan 6,9%. minal, grafik n kecuraman babkan oleh kan femm ktuasi medan celah udara, akan segmen pukan atau femm 4.2 a data jenis pada magnet ; g t n t u t m h g n s k g n , p k n h m n , n u 2 s t p. irasari et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 23-30 30 material silicon steel sheet tidak tersedia lengkap dalam software tersebut sehingga hasil simulasinya masih perlu dibandingkan dengan perhitungan. penentuan kondisi batas mutlak diperlukan untuk mendapatkan nilai b yang lebih terukur. dalam penelitian ini segmen yang b-nya berpengaruh langsung terhadap pembangkitan emf adalah celah udara (bg). referensi [1] d. žarko, t.a. lipo, d. ban, "analytical calculation of magnetic field distribution in the slotted air gap of a surface pm motor using complex relative air gap permeance," ieee transaction on magnetics, vol. 42, no. 7, pp. 1828-1837, juli 2006. [2] g. mahalingam, a. keyhani, "design of 42v/3000w permanent magnet synchronous generator," electrical engineering department, ohio state university, columbus ohio, technical report 2000. [3] e.s. hamdi,, design of small electrical machine, d.v. morgan, ed. england: john wiley & sons, 1994. [4] c. ghita, a.l. chirila, i.d. deaconu, d.i. ilina, "wind turbine permanent magnet synchronous generator magnetic field study," in icrepq, santender, 2008. [5] y. guo, y. dou, j. zhu, y. zhan, j. jin, "parameter determination and performance analysis of a pm synchronous generator by magnetic field finite element analysis," in power eng. conf., aupec australasian universities , perth, wa , 2007, pp. 1-4. [6] a. parviainen, "design of axial-flux permanent-magnet low-speed machines and performance comparison between radial-flux and axial-flux machines," lappeenranta university of technology, finland, phd thesis isbn 952-214-030-9 (pdf), 2005. [7] r.h. staunton, et al, "pm motor parametric design analyses for a hybrid electric traction drive application," oak ridge national laboratory, department of energy, tennessee, laporan penelitian 2004. [8] k. fujisaki, r. hirayama, y. nemoto, "electromagnetic steel solution in electromagnetic field," environment & process technology center, technical development bureau, nippon steel corporation, electrical steel sheet, technical report 2004. [9] p. irasari, fitriana, "pengaruh harmonik terhadap tegangan keluaran prototip generator magnet permanen kecepatan rendah," teknologi indonesia, vol. 32(1), pp. 1-6, 2009. [10] anonim, "dimension inspection report," ningbo east magnet co.ltd, ningbo, inspection report 2008. [11] m.s. widyan, "design, optimization, construction and test of rare-earth permanent-magnet electrical machines with new topology for wind energy applications," fakultät iv – elektrotechnik und informatik, germany: technischen universität, berlin, ph.d thesis 2006. [12] t.j.e. miller, permanent – magnet and reluctance motor drives , t.j.e. miller, s. yamamura hammon p, ed. new york, usa: oxford university press inc., 1993. [13] d. meeker, finite element methode magnetics version., 2008. [14] m. comanescu, a. keyhani, m. dai, "design and analysis of 42-v permanent-magnet generator for automotive applications," ieee trans. on energy conversion, vol. 18, no. 1, pp. 107-112, march 2003. [15] w. wu, v.s. ramsden, t. crawford, g. hill, "a low-speed, high-torque, direct-drive permanent magnet generator for wind turbines," in industry applications conference ieee, 2000, pp. 147-154. [16] f. libert, j. soulard, "design study of different direct-driven permanent-magnet motors for a low speed application," in norpie, trondheim, norwegia, juni 2004, pp. 1-6. [online]. available: www.elkraft.ntnu.no/norpie/10956873/final %20papers/061%20-%20norpie_061.pdf [17] y. zhang, k. sekine, s. watanabe, "magnetic leakage field due to sub-surface defects in ferromagnetic specimens," in ndt & e international, 1995, pp. 67-71. [18] j. philip, c.b. rao, t. jayakumar, b. raj, "a new optical technique for detection of defects in ferromagnetic materials and components," in ndt&e international, 2000, pp. 289-295. [19] c. c hwang, y. h. cho, "effects of leakage flux on magnetic fields of interior permanent magnet synchronous motors," ieee transactions on magnetics, vol. 37, no. 4, pp. 3021-3024, juli 2001. [20] l. cano, l. arribas, i. cruz, "1.5 kw permanent magnets synchronous generator experimental bench test," in ewec, london, 2004, pp. 1-9. [21] p. irasari, fitriana, "perancangan dan analisa prototip generator magnet permanen radial fluks kecepatan rendah," teknologi indonesia, vol. 31, no. 2, pp. 75-82, 2008 mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.95-103 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. effect of different core materials in very low voltage induction motors for electric vehicle fransisco danang wijaya a, *, iftitah imawati b, muhammad yasirroni a, adha imam cahyadi a a department of electrical engineering and information technology, universitas gadjah mada jl. grafika 2, yogyakarta, 55283, indonesia b department of electrical engineering, universitas islam indonesia jl. kaliurang km 11, yogyakarta, 55281, indonesia received 5 september 2021; accepted 16 november 2021; published online 31 december 2021 abstract the use of squirrel cage induction motor for electric vehicle (ev) has been increasingly popular than permanent magnet and brushless motors due to their independence on rare materials. however, its performance is significantly affected by the core materials. in this research, induction motors performance with various core materials (m19_24g, arnon7, and nickel steel carpenter) are studied in very low voltage. three phases, 50 hz, 5 hp, 48 v induction motor were used as the propulsion force testbed applied for a golf cart ev. the aims are to identify loss distribution according to core materials and compare power density and cost. the design process firstly determines the motor specifications, then calculates the dimensions, windings, stator, and rotor slots using matlab. the parameters obtained are used as inputs to ansys maxwell to calculate induction motor performance. finally, the design simulations are carried out on rmxprt and 2d transient software to determine the loss characteristics of core materials. it is found that the stator winding dominates the loss distribution. winding losses have accounted for 52-55 % of the total loss, followed by rotor winding losses around 25-27 % and losses in the core around 1-7 %. based on the three materials tested, nickel steel carpenter and m19_24g attain the highest efficiency with 83.27 % and 83.10 %, respectively, while m19_24g and arnon7 possess the highest power density with 0.37 kw/kg and 0.38 kw/kg whereas, in term of production cost, the arnon7 is the lowest. ©2021 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: squirrel cage induction motor; power losses; power density; power efficiency; loss distribution. i. introduction recently, efforts to reduce gas emissions to make global improvements have been made in many sectors, for example, by switching to electric vehicles transportation. it is shown that the electric vehicles can significantly reduce dependence on fossil fuels. one of the main components of electric vehicles is its electric motors [1][2]. in general, electric motors use permanent magnets such as the permanent magnet synchronous motor (pmsm) and brushless dc motor (bldc). however, the increasing use of permanent magnets as electric vehicle becomes more problematic as it uses an extremely rare material. in order to reduce the dependency on permanent magnet material, the utilization of induction motors can play a key role [3][4][5]. squirrel cage induction motor (scim) is one type of motor that can be used in electric vehicles [6]. this scim has been used in various applications such as in golf cart electric vehicles which has been intensively used in resorts, hotels and retirement villages, airports, shopping malls, hospital, university campus, and others. as an induction motor is always supplied by an ac voltage, hence it must be equipped with an inverter to change the dc voltage from the battery to ac voltage. in addition, the ac voltage needs to be controlled to regulate the speed of the induction motor. extra or very low voltage system of induction motor for evs has been discussed in [7][8][9] to avoid the high voltage human risks, expensive and complex insulation of high voltage system, and reduce dv/dt (the instantaneous rate of voltage changes with respect to time) which may affect the system reliability and * corresponding author. tel: +62-74-552330 e-mail address: danangwijaya@ugm.ac.id https://dx.doi.org/10.14203/j.mev.2021.v12.95-103 https://dx.doi.org/10.14203/j.mev.2021.v12.95-103 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.95-103 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.95-103&domain=pdf f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 96 motor life-time. therefore, very low voltage as defined in iec 61140:2016 is selected to suplly induction motor as ev drivers in this research. although an scim has simple construction, it has advantages of strong, fast, high-speed areas with inverters, low ripple, and minimum maintenance. unfortunately, this motor also has a low efficiency [10]. to improve the efficiency, it can be done by reducing the components that contribute to power losses. there are five components of induction motor loss, namely stator loss, rotor loss, core loss, stray loss and mechanical loss. design and calculation on scim for mini electric vehicle has been done in [11] with 43 v, 50 hz, 4 kw using cast aluminium and copper for rotor core material. in this research, an scim design method with a low power rating of 5 hp and a very low voltage of 48 v using three materials namely m19_24g, arnon7, and nickel steel carpenter is developed to identify loss distribution in those loss components. it can be carried out by varying the core material of the stator and rotor. the magnetic materials are the paramount aspect in the design of induction machines especially for those which use only soft magnetic materials (no permanent magnet machines) such as induction motors [12]. in regards to above mentioned problems, this paper investigates the effects of core materials on the performance and losses distribution of induction motors and then compares the power density and cost of each material. ii. materials the design model is proposed based on the specification rating of scim which is identified from standards and material datasheets. based on this data, a numerical calculation process using matlab simulation was done. the result of the calculation will be passed to ansys software to get the detail characteristic operation performances [12]. to drive an electric golf cart with rated speed 30 km/h, scim design must have fulfilled the technical requirement such as torque to speed characteristics. in the previous research [8][13], nema class c motor design was used, whereas this study used a motorcycle design choice that followed nema of class a. a. scim design specifications in general, motors used in the industry are usually not operated in extreme work cycles. on the other hand, motors for electric vehicle applications must be able to adapt to a driving pattern that can accommodate difference in speed and torque characteristics [14][15]. for example, the constant torque operating area is still needed when the vehicle starts and climbs uphill while the constant power operation area is still needed when the vehicle is traveling at high speed. in constant power region, if the motor is fed by constant voltage, the pull-out torque of the motor decreases proportionally to the squared speed. the typical mechanical characteristic of the induction motor can be seen in figure 1. in general, induction motor for electric vehicles is required to control its speed over a wide range in a fixed power operating area. it can be obtained by increasing the breakdown torque value at base speed. as a result, this is one of the considerations in the induction motor design process used for electric vehicles [16]. other factors that can be considered for electric vehicles are efficiency, power factor and power density (kw/kg). the design process is initiated by identifying the type or characteristic of the load that will be driven by the motor. the desired specifications are stated in table 1 and will be used in the calculation. b. material specifications various studies have been conducted in the selection of stator and rotor core material for induction motors [17][18][19]. in this study, we focused only on three most common materials used as scim cores for fair investigation. the three materials of m19_24g, arnon7, and nickel steel carpenter were chosen among the materials that are often used in the scim design process. the magnetic properties of each material are represented by the b-h curve as shown in figure 2. these three materials also have a constant figure 1. the typical mechanical characteristic of the induction motor for ev table 1. desired specification of scim symbol quantity value unit pn output power 5 hp 𝑉1𝑝ℎ the rated line to the line rms voltage 48 v − connection type wye 𝑓1 rated frequency 50 hz 2𝑝1 number of poles 4 𝑚 phase number 3 𝜔𝑏 base speed 1500 rpm 𝜔𝑚 maximum speed 4500 rpm 𝑇𝑛 rated torque 24 nm 𝜂 efficiency at rated 0.82 𝑐𝑐𝑐 𝜃 pf at rated 0.83 𝑆𝑛𝑛 rated slip ≤ 5% 𝑇𝑏𝑏 breakdown torque 1.75-3 a p.u 𝑇𝐿𝐿 locked rotor torque 0.72.75a p.u 𝐼𝐿𝐿 locked rotor current 6-8 p.u 𝑇 operating temperature 80 oc ahigher value are for motors with lower horsepower ratings f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 97 value to calculate the value of the core losses. the calculation of the software is carried out using the bertotti expression [18]. according to the loss-separation principle by bertotti [18], the conventional three-terms iron loss model can be expressed as follows: 𝑃𝑐𝑐𝑐𝑐 = 𝑃ℎ𝑦𝑦𝑦 + 𝑃𝑐𝑒𝑒𝑦 + 𝑃𝑐𝑒𝑐𝑐𝑦𝑦 (1) where, 𝑃ℎ𝑦𝑦𝑦 = 𝐾ℎ𝐵2𝑓 (2) 𝑃𝑐𝑒𝑒𝑦 = 𝐾𝑐𝐵2𝑓2 (3) 𝑃𝑐𝑒𝑐𝑐𝑦𝑦 = 𝐾𝑐(𝐵𝑓) 3 2 (4) the first term represents the loss of hysteresis (physt), the second term is the loss of the classic eddy current (peddy), and the latter denotes the loss of excess (pexcess). the constant values of kh (hysteresis constant), kc (eddy current constant) and ke (excess constant) for each material can be seen in table 2. value b is the flux density of the core material at a certain frequency (f). iii. methods there are five kinds of loss present in an induction motor which are stator losses, rotor losses, core losses, stray losses and mechanical losses. initial stray losses and mechanical losses must be calculated and will be used as inputs for ansys maxwell. a. losses 1) stray losses despite the fact that stray loss exists, it is normally very difficult to be determined. based on [17] the stray losses are similar to the assigned values of iec 60034-2-1. the value depends on the power rating (pn) for 1 kw< pn <10 mw. stray losses (ps) can be expressed in equation (5). where p1 is input power and p2 is output power. 𝑃𝑦 = �0.025 − 0.005 𝑙𝑐𝑙10 � 𝑃2 1𝑏𝑘 ��𝑃1 (5) 2) mechanical losses mechanical losses are related to complex aerodynamic and friction phenomena, and experimental testing is important. the total mechanical loss (pm) depends on engine size and pole number. average mechanical loss of 4 pole motors are around 1.5 % of output power for under 2.2 kw rating and 1 % above 3.7 kw rating. the value suggested by [18] is expressed as follows 𝑃𝑚 = 0.01𝑃𝑛 𝑓𝑐𝑓 𝑃𝑛 ≥ 3.7𝑘𝑘 (6) 3) stator and rotor winding losses these losses occur when current flows in the stator and rotor. when there is a change in the load current flowing in the stator and rotor, they will also change accordingly [19]. the value of stator winding losses (pco) and rotor winding losses (pal) does not only depend on the stator rated current (i1n), but also on the value of the stator and rotor winding resistances (rs and rr), both losses are expressed as 𝑃𝐶𝐶 = 3𝑅𝑦𝐼1𝑛2 (7) 𝑃𝐴𝑛 = 3𝑅𝑐𝐼1𝑛2 (8) b. main dimension calculation of main dimensions starts by determining the transfer power through the air gap (sgap) expressed as follows 𝑆𝑔𝑔𝑝 = 𝐾𝐸 𝑃𝑛 𝜂 𝑐𝑐𝑦𝑐 (9) after that, (sgap) is used to calculate the inside diameter of the stator by choosing a ratio of stator inner diameter and length (λ) equals 1.8. as the rule of thumb, greater the ratio, smaller the diameter of the stator [17]. esson's constant (c0) is calculated with linear regression approach and can be found by 𝐶0 = 4.165 𝑆𝑔𝑔𝑝 + 119.872 (10) figure 2. b-h curve of three materials 0.000 0.200 0.400 0.600 0.800 1.000 1.200 1.400 1.600 0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 b (t ) h (a/m) nikel steel car penter aron7 m19_24 gnickel steel arnon7 m19_24g table 2. specification of materials parameter m19_24g arnon7 nickel sc kh 164.20 201.60 9.44 kc 1.3 0.116 0.239 ke 1.72 3.308 1.144 density 7650 kg/m3 7870 kg/m3 8900 kg/m3 price 4 $/kg 0.9 $/kg 23.17 $/kg f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 98 stator inner diameter (𝐷𝑖𝑦) can be found by 𝐷𝑖𝑦 = � 2𝑝1 𝜋𝜋 𝑝1 𝑓1 𝑆𝑔𝑔𝑔 𝐶𝑜 3 (11) based on the standard, the ratio of the selected inside and outside diameters of the stator (λ) is 0.62. the length of the stator can be computed as 𝐿 = 𝜋 𝜋𝐷𝑖𝑖 2𝑝1 (12) with assumption 2p1=4, the length of the air gap (g) can be obtained as 𝑙 = �0.1 + 0.012. �𝑃𝑛 3 �. 10−3m (13) the rotor outer diameter value is obtained from the difference between the stator inner diameter and the length of the air gap, while the value of the inner diameter rotor depends on the depth of the rotor slot. based on these calculations, the difference in materials will not affect the main design of the motor. the design of the main dimensions can be seen in figure 3 and table 3 for the same flux density of b. c. stator stator design consists of two parts, namely winding and slot designs. regulating the stator winding can be carried out by calculating the conductor per slot, the number of strands and wire diameter to be used. the first thing to do when calculating the number of conductors per slot (ns) is calculating the number of turns per phase (w1) first with the following formula 𝑘1 = 𝐾𝐸𝑉1𝑔ℎ 4𝐾𝑓𝐾𝑊1𝑓ф (14) 𝑛𝑦 = 𝑎1 𝑘1 𝑝1 (15) where kf is teeth saturation coefficient, ke is emf coefficient, kw1 is stator winding factor; is pole flux, a1 is number of current paths in parallel, q is number of slots per pole per phase the number of the slots (ns) and area geometry of the slots (as) to be used in the design of the stator can be expressed by 𝑁𝑦 = 2𝑝1𝑞𝑚 (16) 𝐴𝑦 = 𝜋𝑒𝐶𝑜𝑔𝑔𝑛𝑖 4𝐾𝐹𝑖𝐹𝐹 (17) where dco is diameter of the wire, ap is number of conductors in parallel, kfill is fill factor. in this paper, the number of stator slots is 36 slots with each slot containing five conductors with a diameter of 3.081 mm. the stator slot geometry consists of the depth (hs0+hs1+hs2+rs) and width of the slot (bs2). the selected slot for this motor design is the tapered type. the shape of the slot will influence the reactance of the stator. based on as calculation, stator slot design that used for this study shown in figure 4 and table 4. due to the difference in magnetic field strength (h) for the same b magnitude based on the characteristic b-h curve, the bs1 and hs2 value for each design in three materials is different. however this discrepancy is neglected, it is insignificant. d. rotor based on the recommendation given in [19][20], the number rotor slot (nr) combination corresponding to the number of stator slots used is 30 slots. for the three materials used here, the same design factor does not greatly affect the size of the rotor slots so the geometry design tends to be the same. rotor slot design used for this study is shown in figure 5 and table 5. the geometry height (hs0, hs1, hs2), back core height (hcr) and width (bs0, bs1, bs2) components of the rotor slot will affect the diameter of the shaft (dshaft) and the length of end ring (b) used in the design is calculated as follows �𝐷𝑐ℎ𝑎𝑓𝑡�𝑚𝑎𝑥 ≤ 𝐷𝑖𝑐 − 2𝑙 − 2 �ℎ𝑦1 + ℎ𝑦2 + (𝑏𝑖1+𝑏𝑖2) 2 + ℎ𝑐𝑐� (18) 𝑏 = (1.1) �ℎ𝑦0 + ℎ𝑦1 + 𝑏𝑦0 + 𝑏𝑦1 + (𝑏𝑖1+𝑏𝑖2) 2 � (19) the rotor bar current (ib) and end rings current (ier) can be calculated using the following calculation. where ki is rotor and stator mmf ratio, nr is number of rotor slots. 𝐼𝑏 = 𝐾𝐼 2𝑚𝑘𝟏𝐾𝑤1 𝑁𝑟 𝐼1𝑛 (20) 𝐼𝑐𝑐 = 𝐼𝑏 2𝑦𝑖𝑛𝜋𝑔1 𝑁𝑟 (21) the area of rotor bar (aer) can be calculated using equation (21), the current density (jer) for the selected end ring is 6 a/mm2 [16]. 𝐴𝑐𝑐 = 𝐼𝑒𝑟 𝐽𝑒𝑟 (22) the value of the end ring width (a) is equal to 𝑎 = 𝐴𝑒𝑟 𝑏 (23) figure 3. scim geometry table 3. calculated main dimension symbol quantity value (mm) 𝐷𝑐𝑦 stator outer diameter 185.7 𝐷𝑖𝑦 stator inner diameter 117 𝐿 length 110 𝐷𝑐𝑐 rotor outer diameter 116.7 𝐷𝑖𝑐 rotor inner diameter 52 𝑙 air gap 0.3 dir stator core dor dos f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 99 the calculation result from matlab for the motor geometry will be used as input into the rmxprt ansys maxwell software. iv. results and discussions a. performance based on rmxprt simulation results, the performance of the motor design under different core materials has no significant differences. the three designs have power factor, rated torque and slip of about 0.93, 24.5 nm and 4-5 %. the efficiencies for m19_24g, arnon7 and nickel steel carpenter core are 83.10 %, 82.18 % and 83.25 %, respectively. the prominent difference was located on the contribution of losses in each motor design. the characteristic of the motors is defined by torque-speed curves as shown in figure 6. from these curves, locked rotor torque information and breakdown torque data can be found. furthermore, it is shown that all three materials have different locked rotor torque but when approaching the rating speed, the torque of all three materials has the same magnitude (rated torques of all three designs are the same). the locked rotor torque and the breakdown torque of each design has different values. at low speed, m19_24g material has the greatest value compared to others. characteristics of current-speed of the two designs are shown figure 7. the curve shows the material with the core m19_24g has the highest initial current or locked rotor current value, followed by arnon7 and nickel steel carpenter, whose values are 283.297a, 273.951a, and 270.395a. the efficiency-speed curve in figure 8 shows that the three materials are having similar characteristics. the efficiency at the rated of the design with the nickel steel carpenter material has the highest efficiency, which is 83.24 %, followed by arnon7 and m19_24g with 82.18 % and 82.16 %. figure 9 shows the efficiency-torque of scim. at low load torque and high-speed region, the highest efficiency occurs. figure 6. torque-speed curve of three materials figure 4. detailed stator slot [8] table 4. stator geometry parameter value ns 36 slots hs0_stator 1 mm hs01_stator 4 mm hs2_stator 15 mm bs0_stator 3 mm bs1_stator 6.5 mm bs2_stator 3 mm figure 5. detailed rotor slot table 5. rotor geometry parameter value nr 30 slots hs0_rotor 0.5 mm hs01_rotor 0.2 mm hs2_rotor 10 mm bs0_rotor 4 mm bs1_rotor 6.3 mm bs2_rotor 4 mm f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 100 moreover, since the torque increases with speed reduction, there is no significant difference in efficiency between three materials at high speed. after creating the basic structure of the im, the geometry and the materials can be converted to the maxwell magnetic analysis software. the software is configured by 2d and 3d transient solver options. the program has solutions for 2d and 3d transient solvers. for this part of the study, we used 2d to analyze the design. the result of the 2d transient is shown in figure 10 and figure 11 shows the starting torque and the current for the time response. it is also seen how the specified torque-speed values are precisely met. the results of the analytical design and the 2d transient finite element analysis (fea) are confirmed by the constant current, speed, torque and power factor. b. losses distribution based on the results of the simulation of rmxprt using these three different materials, it found that the distribution of losses in the induction motor is dominated by losses in the winding stator as shown in figure 12. winding stator losses have accounted for around 52-55 % of the total loss, followed by losses on the winding rotor around 25-27 % and figure 7. current-speed curve of three materials figure 8. efficiency-speed curve of three materials figure 9. efficiency-torque curve of three materials f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 101 losses caused by the core around 1-7 %. in the calculation, the value of stray losses and mechanical losses are determined, each of which is 5 % and 11 % of total loss. the total loss of scim with materials; m19_24g, arnon7 and nickel steel carpenter were 779.936 w, 777.489 w and 715.765 w. comparing the result of total loss of scim with reference [11] for 34 v, frequency 50 hz, rated power 4 kw, stator 30 slots, rotor 26 slots, the total loss was 896 watt using cast aluminium core material and 746.2 watt with copper core material. meanwhile, the scim efficiencies were 81.7 % using cast aluminium core material and 86.3 % with copper core material. from the data, it is shown that losses in the core of nickel steel carpenter material have the smallest losses than the other materials. nickel steel carpenter has the highest efficiency with the smallest core losses. from rmxprt simulation, we also saw the material consumption needed for the motor core and total net weight in each design, it is shown in table 6. so we can calculate the cost materials needed for each motor production and the power density for each motor. depending on the power density of each design, scim with m19_24g core has the best power density, however nickel steel carpenter core motor has the worst power density. moreover, nickel material is rarely used because the price is very expensive compared to the two other materials. compared to the rotor design in figure 10. starting torque as a function of time figure 11. stator current as a function of time table 6. material consumption and power density materials net weight (kg) core consumption power density (kw/kg) cost core production ($) stator (kg) rotor (kg) m19_24g 9.719 15.101 12.057 0.380 108.632 arnon7 9.987 15.500 12.404 0.370 25.144 nickel_sc 20.795 17.576 14.072 0.180 733.284 f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 102 references [8] and [13], the resulting rotor design is easier to fabricate because it only apply single slot rotor. v. conclusion the losses distribution of induction motor for very low voltage system applied to golf cart with different core materials (m19_24g, arnon7, and nickel steel carpenter) had been analyzed. it is seen that the stator winding losses have an approximate of 52-55 % from the total loss, followed by losses on the rotor winding that is around 25-27 % and the losses caused by the core is around 1-7 % from the total loss. because of these facts, we conduct further study to minimize the winding of the stator. this can further be used as a reference to enhance scim efficiency. based on the findings in this paper, nickel steel carpenter and m19_24g have the highest efficiency at 83.27 % and 83.10 %, respectively. further, m19_24g and arnon7 have the highest power density at 0.37 kw/kg and 0.38 kw/kg, respectively. from the discussions we conclude that the cheapest core production is arnon7 materials. acknowledgment the authors would like to thank laboratorium teknik tenaga listrik, department of electrical and information technology faculty of engineering universitas gadjah mada for all the provided facilities. declarations author contribution fransisco danang wijaya is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] k. t. kim, hye eun song and gwan soo park, "a study on the design of induction motor in low speed urban electric vehicle," ieee transportation electrification conference and expo, asiapacific (itec asia-pacific), pp. 866-869, 2016. [2] m. t. güneşer, a. dalcalı, t. özturk and c. ocak, "influence of rotor slot structure at starting torque and efficiency on urban use ev motor," international conference on power generation systems and renewable energy technologies (pgsret), pp. 14, 2019. [3] a. marfoli, m. d. nardo, m. degano, c. gerada and w. jara, "squirrel cage induction motor: a design-based comparison between aluminium and copper cages," in ieee open journal of industry applications, vol. 2, pp. 110-120, 2021. [4] m. j. akhtar and r. k. behera, "an analytical design of an induction motor for electric vehicle application," ieee 12th international conference on compatibility, power electronics and power engineering, pp. 1-6, 2018. [5] y. l. karnavas, "influence of soft magnetic materials application to squirrel cage induction motor design and performance," engineering journals, vol. 21, pp. 193-206, 2017. [6] l. aarniovuori, m. niemelä, j. pyrhönen, w. cao and e. b. agamloh, "loss components and performance of modern induction motors," international conference on electrical machines (icem) xiii, pp. 1253-1259, 2018. [7] t. s. aglan and h. a. ashour, “reduced voltage combined ac motor and drive system for safe electric vehicle,” first international conference on renewable energies and vehicular technology, march, pp. 199–205, 2012. [8] i. imawati, f. d. wijaya and b. sugiyantoro, "design and simulation of three phase squirrel cage induction motor in low voltage system 48v 50hz 3hp for electric golf cart," 11th international conference on information technology and electrical engineering (icitee), pp. 1-6, 2019. [9] p. mishra and s saha, "design modeling and simulation of low voltage squirrel cage induction motor for medium weight electric vehicle", international conference on advances in computing, august, pp. 1697-1704, 2013. [10] d. zhang, j. shi, h. zhao and t. wu, "loss characteristic analysis of small and medium-sized induction motors fed by pwm inverter based on the experiment measurements," iecon 2017 43rd annual conference of the ieee industrial electronics society, pp. 2053-2058, 2017. [11] cheng shukang, li cuiping, chai feng, gong hailong, “research on induction motor for mini electric vehicles,” international conference on future electrical power and energy systems, pp. 249-257, 2012. figure 12. losses distribution of scim https://mev.lipi.go.id/ https://doi.org/10.1109/itec-ap.2016.7513071 https://doi.org/10.1109/itec-ap.2016.7513071 https://doi.org/10.1109/itec-ap.2016.7513071 https://doi.org/10.1109/itec-ap.2016.7513071 https://doi.org/10.1109/pgsret.2019.8882707 https://doi.org/10.1109/pgsret.2019.8882707 https://doi.org/10.1109/pgsret.2019.8882707 https://doi.org/10.1109/pgsret.2019.8882707 https://doi.org/10.1109/pgsret.2019.8882707 https://doi.org/10.1109/ojia.2021.3073820 https://doi.org/10.1109/ojia.2021.3073820 https://doi.org/10.1109/ojia.2021.3073820 https://doi.org/10.1109/ojia.2021.3073820 https://doi.org/10.1109/cpe.2018.8372529 https://doi.org/10.1109/cpe.2018.8372529 https://doi.org/10.1109/cpe.2018.8372529 https://doi.org/10.1109/cpe.2018.8372529 https://doi.org/10.4186/ej.2017.21.1.193 https://doi.org/10.4186/ej.2017.21.1.193 https://doi.org/10.4186/ej.2017.21.1.193 https://doi.org/10.1109/icelmach.2018.8507189 https://doi.org/10.1109/icelmach.2018.8507189 https://doi.org/10.1109/icelmach.2018.8507189 https://doi.org/10.1109/icelmach.2018.8507189 https://doi.org/10.1109/revet.2012.6195271 https://doi.org/10.1109/revet.2012.6195271 https://doi.org/10.1109/revet.2012.6195271 https://doi.org/10.1109/revet.2012.6195271 https://doi.org/10.1109/iciteed.2019.8929987 https://doi.org/10.1109/iciteed.2019.8929987 https://doi.org/10.1109/iciteed.2019.8929987 https://doi.org/10.1109/iciteed.2019.8929987 https://doi.org/10.1109/iciteed.2019.8929987 https://doi.org/10.1109/icacci.2013.6637437 https://doi.org/10.1109/icacci.2013.6637437 https://doi.org/10.1109/icacci.2013.6637437 https://doi.org/10.1109/icacci.2013.6637437 https://doi.org/10.1109/iecon.2017.8216345 https://doi.org/10.1109/iecon.2017.8216345 https://doi.org/10.1109/iecon.2017.8216345 https://doi.org/10.1109/iecon.2017.8216345 https://doi.org/10.1109/iecon.2017.8216345 https://doi.org/10.1016/j.egypro.2012.02.091 https://doi.org/10.1016/j.egypro.2012.02.091 https://doi.org/10.1016/j.egypro.2012.02.091 https://doi.org/10.1016/j.egypro.2012.02.091 f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 95-103 103 [12] z. ferkova, "comparison of two-phase induction motor modeling in ansys maxwell 2d and 3d program," elektro, rajecke teplice, pp. 279-284, 2014. [13] i. imawati, f.d. wijaya, “desain dan simulasi motor induksi sangkar tupai tiga fase dengan sistem tegangan rendah 48 v 50 hz 3 hp sebagai penggerak kendaraan listrik golf cart,” skripsi, 2019. [14] h. toda, k. senda, s. morimoto and t. hiratani, "influence of various non-oriented electrical steels on motor efficiency and iron loss in switched reluctance motor," ieee transactions on magnetics, vol. 49, no. 7, pp. 3850-3853, 2013. [15] e. b. agamloh, a. boglietti, and a. cavagnino, “the incremental design efficiency improvement of commercially manufactured induction motors,” ieee transactions on industry applications, vol. 49, no. 6, pp. 2496–2504, nov. 2013. [16] yiming shen, changqing zhu, xiuhe wang, “slot optimization design of induction motor for electric vehicle,” the 5th annual international conference on material science and environmental engineering (msee2017), pp 1-7, december 2017. [17] rotating electrical machines – part 2-1: standard methods for determining losses and efficiency from tests (excluding machines for traction vehicles). ed. 2, iec 60034-2-1, june 2014. [18] feng yanlia, zhang chengning, “analytical calculation for predicting the core loss of surface-mounted permanent magnet machine,” the 8th international conference on applied energy, pp 2119–2124, 2016. [19] kim d.j, chun y.d, han pil-wan, “the study of the stray load loss and mechanical loss of three phase induction motor considering experimental results,” journal of electrical engineering and technology, vol. 9 issue 1, pp. 121-126, 2014. [20] boldea ion and nasar, the induction machines design handbook. 2nd edition, crc, 2002. https://doi.org/10.1109/elektro.2014.6848902 https://doi.org/10.1109/elektro.2014.6848902 https://doi.org/10.1109/elektro.2014.6848902 http://etd.repository.ugm.ac.id/penelitian/detail/171601 http://etd.repository.ugm.ac.id/penelitian/detail/171601 http://etd.repository.ugm.ac.id/penelitian/detail/171601 http://etd.repository.ugm.ac.id/penelitian/detail/171601 https://doi.org/10.1109/tmag.2013.2242195 https://doi.org/10.1109/tmag.2013.2242195 https://doi.org/10.1109/tmag.2013.2242195 https://doi.org/10.1109/tmag.2013.2242195 https://doi.org/10.1109/tia.2013.2263212 https://doi.org/10.1109/tia.2013.2263212 https://doi.org/10.1109/tia.2013.2263212 https://doi.org/10.1109/tia.2013.2263212 https://doi.org/10.1088/1757-899x/301/1/012081 https://doi.org/10.1088/1757-899x/301/1/012081 https://doi.org/10.1088/1757-899x/301/1/012081 https://doi.org/10.1088/1757-899x/301/1/012081 https://doi.org/10.1088/1757-899x/301/1/012081 https://webstore.iec.ch/publication/121 https://webstore.iec.ch/publication/121 https://webstore.iec.ch/publication/121 https://webstore.iec.ch/publication/121 https://doi.org/10.1016/j.egypro.2017.03.595 https://doi.org/10.1016/j.egypro.2017.03.595 https://doi.org/10.1016/j.egypro.2017.03.595 https://doi.org/10.1016/j.egypro.2017.03.595 https://doi.org/10.5370/jeet.2014.9.1.121 https://doi.org/10.5370/jeet.2014.9.1.121 https://doi.org/10.5370/jeet.2014.9.1.121 https://doi.org/10.5370/jeet.2014.9.1.121 https://doi.org/10.1201/9781315222592 https://doi.org/10.1201/9781315222592 introduction ii. materials a. scim design specifications b. material specifications iii. methods a. losses 1) stray losses 2) mechanical losses 3) stator and rotor winding losses b. main dimension c. stator d. rotor iv. results and discussions a. performance b. losses distribution v. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.72-78 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: charlotha et al., “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 72-78, july 2022. fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology charlotha a, *, roberth viktoria manurung b, aminuddin debataraja c, indra dwisaputra a, subkhan d, iqbal syamsu b, e a electrical and informatics department, politeknik manufaktur negeri bangka belitung kawasan industri airkantung, sungailiat, 33211, kepulauan bangka belitung, indonesia b research center for telecommunication, national research and innovation agency (brin) jl. sangkuriang-komplek lipi gedung 20, bandung 40135, indonesia c electro engineering, politeknik negeri jakarta jalan prof. dr. g.a. siwabessy, depok, 16425, jawa barat, indonesia d mechanical engineering department, politeknik manufaktur negeri bangka belitung kawasan industri airkantung, sungailiat, 33211, kepulauan bangka belitung, indonesia e institute of semiconductor technology (iht), laboratory for emerging nanometrology (lena) technische universität braunschweig, langer kamp 6, 38106 braunschweig, germany received 10 august 2021; 1st revision 26 december 2021; 2nd revision 27 april 2022; 3rd revision 17 may 2022; 4th revision 19 may 2022; accepted 23 may 2022; published online 29 july 2022 abstract nitrate is one of the nutrients that can give an effect on the environment if it is applied in excess. it is also easily soluble in water and it has the potential to be a pollutant in groundwater by the over-process of fertilizer. therefore, it needs a detected component to give the right measure for nitrate in the soil, called a nitrate ion sensor. it consists of three electrodes configuration, namely, working, counter, and reference electrodes with conductive polyaniline doped with nitrate (no₃‾) which is fabricated by thick film technology. in previous research, acidic media was used as a solvent for polyaniline, while this research used water (h2o) solvent. the result of characterization showed that particles were distributed evenly on the sample with the form of particles being small balls with a dimension of 0.18 µm and the percentage of atomic elements being: 91.96 % carbon, 3.14 % nitrogen, and 4.9 % oxygen. the performance of sensors was investigated using potentiostat with four concentrations of nitrate standard solution. the result showed good response with a voltage range in each concentration of nitrate standard solution being 0.5002 volt (10 mg/l), 1.3552 volt (20 mg/l), 1.1208 volt (50 mg/l), and 0.8963 volt (100 mg/l). it was found that nitrate sensors with nitrate-doped conductive polymer, polyaniline, as the sensitive membrane responded well to detecting nitrate elements in precision farming and the sensitivity showed that for every 1 mg/l concentration in nitrate standard solution, the voltage increases by 0.0007. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: electropolymerization process; performance of nitrate sensor; the polyaniline; thick-film technology. i. introduction this indonesia as an agrarian country has quite extensive agricultural land and most of its people work in this sector. based on statistics indonesia (bps), non-ministerial government, which contains the indonesian labor situation as of february 2018, it is stated that the percentage of indonesian workers working in agriculture is 30.46 % [1]. one of the factors supporting the production of the agricultural sector is the fulfillment of macronutrients consisting of nitrogen (n), phosphor (p), and kalium (k). nitrogen is an element that is needed in large quantities and is often found in soil in the chemical bonds of nitrates (no₃‾) or ammonium (nh₄⁺). nitrate is one of the macronutrients which is easily evaporated and easily absorbed by water so that the availability of nitrate in the soil can be limited and it takes the addition of nitrate by nitrogen, phosphorus, and potassium (npk) fertilizer. however, fertilizer application must also follow the rules and must know the condition of the land to be used and this is * corresponding author. tel: +62-71793586; fax: +62-71793585 e-mail: charlothaark@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.72-78 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.72-78 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.72-78&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 73 rarely applied so that if there is an excess of nitrate due to excess fertilizer then this can cause water pollution to the soil [2][3][4]. the list of chemical parameters for environmental health purposes, which are contained in table 3 chapter ii in the republic of indonesia minister of health regulation number 32 of 2017 concerning environmental health quality standards and water health requirements for sanitary hygiene, swimming pools, solus per aqua (spa), and public baths, explained that nitrates are included in the mandatory chemical parameters among the ten other mandatory chemical parameters (including: ph, iron, fluoride, manganese, cyanide) and the level of nitrate as n that is allowed in soil and water land is 10 mg/l [5]. research related to the detection of nitrate levels in soil has been carried out. one of them uses conventional technology, namely, the process of detection by taking soil samples to the laboratory for research (sampling process), but this process takes a long time and costs a lot. this led to the emergence of other methods, namely: a fertilizer detection sensor based on the infrared ray that has been combined into a data acquisition system that can detect levels of npk fertilization [6][7][8]. the development of fertilizer sensors is also carried out using an optical transducer, leds, and photodiodes that can detect npk fertilizer levels by displaying fertilizer levels, namely low voltage, medium voltage, and high voltage [9][10][11]. other research that has also been widely developed is detecting of nitrate levels using nitratedoped conductive polymer of polypyrrole as the sensitive membrane to coat electrodes that have been fabricated using thick-film technology. the results of the study show that these electrodes have good performance and can be used to detect nitrate levels in the soil [12][13][14]. based on previous research about polyaniline, among the conducting polymers, polyaniline has received much attention and intensive research work has been performed with the polymer in its native state or functionalized form. this is mainly because polyaniline and its derivatives or composites or co-polymers with other materials are easy to synthesize chemically or electrochemically by oxidative polymerization [15]. in this study, the fabrication was carried out using conductive polymer polyaniline (pani) sensitive membrane with water (h2o) solvent as a substitute for polypyrrole that will be doped with nitrate in the same fabrication method, namely, thick film technology [16][17][18]. in some research, the sensor was fabricated using polyaniline and polypyrrole thin film immobilized glass surfaces. polyaniline sensor gives a good response at low humidity conditions and saturates at high humidity conditions. the sensitivity of the polypyrrole sensor is higher at high humidity levels. polypyrrole sensor showed quick response and recovery times compared to polyaniline sensor [19][20][21]. when it is compared with the previous method used in previous research, water (h2o) solvent is a good solvent for polypyrrole (monomer and polypyrrole) because polypyrrole, which will be the doping material, is easily soluble in water compared with other solvents, and it is easily electro synthesized in aqueous solution [22][23]. ii. materials and methods a. equipments and materials manuscript the were some equipments that were used in this research: beaker, which is used as a container to react materials, a container to contain chemicals in the form of solutions, solids, pastes or flour, a place to dissolve materials and a place to heat materials; digital scale, a measuring device used to measure the weight or mass of an object or substance; potentiostat, an electronic device used to measure the concentration of a substance resulting from a reduction-oxidation reaction; digital multimeter, which is an electronic device that is used to measure electric current, which has two kinds of currents that are direct current (dc) and alternating current (ac); nitrogen gas cylinders, which are used to transfer the pressure, at the beginning of the electropolymerization process; power supply, which is used to increase or decrease the voltage, in every process of electrical circuit; computer, which is used to processing data and; to give an output result; screen maker model 3000tt, which is used to screen print the sensor design that has been made with smoother and better results; furnace infrared/infrared heater (radiant technology), which is to produce heat energy and burn the sensor that has been printed with a screen maker, with the appropriate temperature measurement to produce a good sensor. some materials that were used were: alumina, which was the material that was used as a substrate; platinized carbon paste (ferro), and ag|agcl (ferro) which were used for making an electrode design (working electrode, counter electrode, and reference electrode); conductive polymer polyaniline (pani/c6h7n) (sigma-aldrich) and nitrate/no₃‾ (from sodium nitrate/nano3) (sigma-aldrich) that were used as a dopant for sensitive membrane; al2o3 (merck) that was used for the purification process of pani; nitrate standard solution in 1.000 mg/l no₃‾ (merck) that was used for sensor performance testing. b. design of nitrate sensors in this research, the design of working electrodes, reference electrodes, and counter/auxiliary electrodes were made with corel draw software to determine the design and layout of the three electrodes. the design and layout of the electrodes were chosen based on several things, including the area and the connectivity of each electrode. in addition, several experiments have been done regarding the design and layout of the electrodes. the electrode design is shown in figure 1. c. sensitive membrane the first process to produce a sensitive membrane is the purification process of polyaniline charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 74 using al2o3 for the preparation of a sensitive membrane doped with nitrate (no₃‾). the second process is the dissolution of liquid polyaniline (c6h7n) with water (h2o) as a solvent, while previous studies used acid media as a solvent [15]. the last process is the dissolution of solid/crystal (granular) sodium nitrate (nano3) with water (h2o) as a solvent in a correct measurement to get a nitrate concentration and to get sensitive membrane consisting of polyaniline (pani) 1 m and nitrate (no₃‾) 0.1 m. d. the fabrication process with thick film technology thick film technology is a ‘printing’ and ‘firing’ technology that uses conductive, capacitive, and insulation paste which is depositioned on a pattern with screen printing method and then processed at the temperature that is according to a substrate and pastes to be used [24][25][26]. the electrode fabrication started with the printing, drying, firing, and packaging process (figure 2a). the working electrode (we) and counter/auxiliary electrodes (ce) are worked on simultaneously because both of them use platinized carbon paste and will be heated at a temperature 120 °c for 15 minutes. the reference electrode (re) and pad use silver|silver chloride (ag|agcl) and are heated in a firing machine (furnace infrared/infrared heater) at a temperature of 800 °c for 30 minutes. the fabricated electrode is shown in figure 2b. e. the electro polymerization/electroplating process the electro polymerization/electroplating process is a process of deposition/coating of sensitive membrane on the working electrode by using a potentiostatic method (measurement with fixed potential) (figure 3). the process is as follows, a solution of 0,1 m nitrate (no₃‾) is mixed with a solution of 1 m polyaniline (c6h7n) in a beaker glass with the same ratio (50:50). the electro polymerization process lasts 30 minutes with a potentiostatic method (fixed potential value) of 1v. during the electro polymerization process, nitrate and polyaniline solution are de-oxygenated through the purging process with nitrogen gas, and the positive voltage source (+) is connected to the working electrode and the negative voltage source (-) is connected to platinum (pt). in 30 minutes of the electro polymerization process, an electron transfer reaction will occur and the resulting current will be recorded and observed. f. electrode examination (nitrate sensor) sensor testing will be done in three steps. the first step was scanning electron microscopy (sem)energy dispersive x-ray spectroscopy (eds), which is a characterization test of the electrodes to get the figure 3. the electro polymerization process uses a potentiostatic method, using nitrogen gas that induces deoxygenated in a beaker which contains electrode and platinum that are connected to a digital multimeter figure 1. the electrode design (a) (b) figure 2. (a) the process of thick film technology; (b) the fabricated electrode, which contains: working electrode (we), counter electrode (ce), reference electrode (re), and pad charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 75 information about the morphology of the sample surface and to analyze quantitatively the percentage of each element. the characterization testing used the instrument with type su3500 10 kv with a magnification 20k secondary electron (se). after that reference voltage testing and characterizing process, which means the examination process that has done by comparing the reference voltage of the electrode that has been made, with the factory reference electrode/commercial ag|agcl reference electrode obtained from acumet in 3 m kcl electrolyte solution (figure 4). the characterization graph will show the comparison of the two and the deviations that occurred will be observable. g. the testing and characterizing of nitrate sensor performance performance testing of nitrate ion sensors used a potentiostat and nitrate standards solution with four concentrations, which were: 10 mg/l, 20 mg/l, 50 mg/l, 100 mg/l (figure 5). the result showed the generated current. iii. results and discussions a. the result of scanning electron microscopy (sem)energy dispersive x-ray spectoroscopy (eds) in sem-eds characterized testing, polyaniline (c6h7n) and nitrate (no₃‾) as a sensitive membrane will be tested to get the morphology and percentage of each atomic element. the first testing showed the morphology of sample elements before electro polymerization (figure 6(a)), while the second testing showed a sample with a particle size that is evenly distributed on the surface of the sample after the electro polymerization process and obtained a shape obtained that formed small balls with the size ranging from 0.18 µm (figure 6(b)). the differences in the percentage of sample elements before and after the electro polymerization process are shown in the tables below (tabel 1). before the electro polymerization process the percentage of atomic elements: 92.38 % carbon and 7.62 % oxygen, while after the electro polymerization process showed the percentage of atomic elements from each element obtained: 91.96 % carbon, 3.14 % nitrogen, and 4.9 % oxygen. it also showed that the carbon element contained in the working electrode material and one of the polyaniline elements (c6h7n) had a large percentage value, which represents that polyaniline evenly coated the sample. on the other hand, nitrogen and oxygen elements have a better percentage value, which indicates that nitrate (no₃‾) has been doped properly. figure 4. the reference voltage examination figure 5. sensor performance testing tabel 1. percentage of sample elements before and after the electro polymerization process element weight % atomic % error % k ratio z a f before after before after before after before after before after before after before after c k 90.09 90.03 92.38 91.96 2.7 2.5 0.8013 0.8184 1.0048 1.004 0.8851 0.9053 1 1 n k 0 3.59 0 3.14 0 40.72 0 0.0027 0 0.977 0 0.0762 0 1 o k 9.91 6.38 7.62 4.9 14.82 19.27 0.0111 0.0066 0.9545 0.9537 0.1176 0.1078 1 1 charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 76 b. the electro polymerization process examinations the graph of the electro polymerization process indicates the appearance of electron transfer reactions with a peak current value of 0.223 ma in the first process, which, however, declines and tends to be stable in the current of 0.01 ma for the last 30 minutes. the current resulted from the electro polymerization process that is shown in figure 7. c. the result of reference voltage testing results the obtained reference voltage was measured by potentiometric process between platinized carbon paste that has been coated with sensitive membrane polyaniline (pani) which is doped nitrate (no₃‾) with the commercial ag|agcl reference electrode from acumet to a kcl electrolyte solution with a concentration of 3 m. this testing has an important role which aims in monitoring the stability of the voltage produced by the electrode and determining whether the electrode can be used in the process of detecting nitrate ions. the graph in figure 8 shows the reference voltage that resulted from this testing. the graph shows that the peak voltage occurs in the first process with a voltage value of 6.58 mv, and is stable at a voltage of about 5 mv, but tends to decrease to 4.41 mv in 30 minutes. it shows that it can be used in the detection process. d. the result of sensor performance testing the performance sensor was tested using potentiostat (resistance of 10 kω) and nitrate standard solutions with 4c and for each concentration, 5 tests were carried out. the voltage result showed good response with voltage output in each concentration being 0.5002 volt (10 mg/l), 1.3552 volt (20 mg/l), 1.1208 volt (50 mg/l), and 0.8963 volt (100 mg/l) (figure 9). the graph shows two output responses that occur at four concentrations of nitrate standard nitrate. the first output voltage response occurred at a concentration of 10 mg/l – 20 mg/l, which displays a voltage that tends to rise linearly proportional to the concentration of the standard nitrate solution, with a voltage of 1.3552 volt. the output voltage response that occurs afterward tends to decrease, which is at a concentration of 20 mg/l – 100 mg/l with a (a) (b) figure 6. (a) sample of morphology before the electro polymerization process; (b) sample of morphology after the electro polymerization process figure 7. current result from the electro polymerization process charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 77 decreasing trend that was linear too with a voltage of 0.8963 volt. in figure 9, the sensitivity shows that for every 1 mg/l concentration in standard nitrate solution, then the voltage increases by 0.0007 iv. conclusion this research proposes several conclusions. sem-eds testing showed the particles of sensitive membrane morphology that were evenly distributed on the surface of the sample and formed small balls with a size ranging from 0.18 µm and eds results indicate atomic element percentage: 91.96 % carbon, 3.14 % nitrogen, and 4.9 % oxygen. in the electro polymerization process, the output currents indicate the electron transfer reaction, with a positive current value indicating that the sensitive membrane coating process on the electrode is successful. the reference voltage testing has an essential role in the testing process which shows that the electrode can be used in the detection process of nitrate ions, with output voltage being around 4.41 mv 6.58 mv. the first output voltage response linearly increased (10 mg/l – 20 mg/l), but then it decreased when the concentration of nitrate standard solution was increased to 50 mg/l – 100 mg/l. it can be concluded that nitrate sensors with 1 m polyaniline and 0.1 m no₃‾ have good performance, especially at a concentration of 20 mg/l. ion sensors with polyaniline sensitive membranes doped with nitrate (no) that have been designed and made can detect nitrate ions with a sensitivity of 0.0007. acknowledgement we are thankful to the indonesian institute of sciences (lipi) for the helpful acknowledgment of the nitrate sensor that was already inspected at lipi figure 8. the reference voltage result figure 9. the voltage result from sensor performance testing charlotha et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 72-78 78 and for the cooperative agreement in funding and equipping the laboratory with tools and materials for the research. we would also like to thank two colleges (politeknik manufaktur negeri bangka belitung and politeknik negeri jakarta) for supporting the program, helpful discussion, and previous studies related to the topic. declarations author contribution charlotha: writing original draft, writing review & editing, conceptualization, formal analysis, investigation, visualization, supervision. robert viktoria manurung: writing original draft, writing review & editing, conceptualization, investigation, validation, data curation. aminuddin debataraja: writing original draft, writing review & editing, conceptualization, investigation, validation, data curation. indra dwisaputra: formal analysis, resources, software, visualization, funding acquisition. subkhan: formal analysis, resources, software, visualization, funding acquisition. iqbal syamsu: formal analysis, resources, software, visualization, funding acquisition. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] n. midayanti, “keadaan ketenagakerjaan indonesia februari 2018,” badan pusat statistik, no. 42, pp. 1–16, mei, 2018. [2] a. debataraja and benny, “implementasi intelligent sensor untuk monitoring kualitas air berbasis komunikasi teknologi jaringan nirkabel zigbee,” prosiding conference on smartgreen technology in electrical and information systems, pp. 115-120, november, 2013. [3] a. fahmi, syamsudin, s. n. h. utami, and b. radjagukguk, “pengaruh interaksi hara nitrogen dan fosfor terhadap pertumbuhan tanaman jagung (zea mays l) [the effect of interaction of nitrogen and phosphorus nutrients on maize (zea mays l.) grown in regosol and latosol soils],” j. biol., vol. 10, no. 3, pp. 297–304, desember 2010. [4] m. thamrin, s. susanto, a. susila, and s. a, “hubungan konsentrasi hara nitrogen, fosfor, dan kalium daun dengan produksi buah sebelumnya pada tanaman jeruk pamelo (correlation between nitrogen, phosphorus, and potassium pummelo citrus) (citrus maxima),” j. hort, vol. 23, no. 3, pp. 225–234, 2013. [5] kementerian kesehatan republik indonesia, “peraturan menteri kesehatan republik indonesia nomor 32 tahun 2017 tentang standar baku mutu kesehatan lingkungan dan persyaratan kesehatan air untuk keperluan higiene sanitasi, kolam renang, solus per aqua, dan pemandian umum,” peraturan menteri kesehatan republik indonesia, pp. 10–15, 2017. [6] d. samira, a. gani, and m. mcleod, “effect of npk fertilizer and biochar residue on paddy growth and yield of second planting,” the proceedings of the 2nd annual international conference syiah kuala univ. 2012 & the 8th imt-gt uninet biosciences conf., november, vol. 2, no. 1, pp. 157–161, 2012. [7] r. rapialdi, j. munir, and m. ernita, “the addition of trichoderma sp. in various types of organic liquid fertilizer to increase npk nutrient uptake and soybean production in ultisol,” journal agro sci., vol. 10, no. 1, pp. 27–33, 2022. [8] t. paper, “pengembangan sistem aquisisi data kadar nitrogen tanah berbasis sensor infra merah sebagai pedoman penentuan dosis pemupukan,” jurnal keteknikan pertanian, vol. 25, no. 2, pp. 147–155, october, 2011. [9] m. yamin et al., “development and calibration of orp sensor for the estimation of macronutrients in the soil of oil palm plantation,” pakistan j. agric. sci., vol. 57, no. 5, pp. 1363– 1369, 2020. [10] s. anand et al., “monitoring of soil nutrients using iot for optimizing the use of fertilizers,” int. journal of science, engineering. and technology research, vol. 8, no. 4, pp. 105– 107, april, 2019. [11] m. masrie, m. s. a. rosman, r. sam, z. janin, “detection of nitrogen, phosphorus, and potassium (npk) nutrients of soil using optical transducer,” 2017 ieee 4th international conference on smart instrumentation, measurement and application, pp. 28–30, march, 2018. [12] a. debataraja, r. v. m. hiskia, “fabrikasi biotranduser dengan metode amperometrik studi awal sensor unsur hara tanah,” prosiding conference on smart-green technology in electrical and information systems, pp. 121–124, november, 2013. [13] b. britz et al., “smart nitrate-selective electrochemical sensors with electrospun nanofibers modified microelectrode,” 2014 ieee international conference on systems, man and cybernetics, pp. 3419-3422, october, 2014. [14] m. anceu, buchari, s. gandasasmita, and z. nurachman, “synthesis and characterization of polypyrole on steel gauze electrode by voltammetry cyclic method,” indonesian journal of materials sci., vol. 13, no. 3, pp. 210–215, june, 2012. [15] k. m. molapo et al., “electronics of conjugated polymers (i): polyaniline,” int. j. electrochem. sci., vol. 7, no. 12, pp. 11859– 11875, 2012. [16] h. karami, m. g. asadi, and m. mansoori, “pulse electropolymerization and the characterization of polyaniline nanofibers,” electrochimica acta, vol. 61, pp. 154–164, feb., 2012. [17] r. ansari and m. b. keivani, “polyaniline conducting electroactive polymers thermal and environmental stability studies,” e-journal of chemistry, vol. 3, no. 4, pp. 202–217, october, 2006. [18] y. mohd, r. ibrahim, and m. f. zainal, “electrodeposition and characterization of polyaniline films,” 2012 ieee symposium on humanities, science and engineering research, pp. 1301– 1306, august, 2012. [19] j. a. irvin, “electrically conducting polymers,” journal of polymer science & applications, vol. 4, issue 2, 2017. [20] c. p. e. kankanamge, h. m. p. c. k. herath, , h. perera, h. r., li chaoyang, d. dissanayake, “comparison of polyaniline and polypyrrole based humidity sensors,” 4th int. symp. of frontier technology, pp. 1–4, july, 2013. [21] m. ait haki et al., “comparative adsorption of nitrate ions on the polypyrrole and polyaniline from aqueous solution,” journal of dispersion science and technology, vol. 38, no. 4, pp. 598–603, may, 2016. [22] s. proses, e. pirol, v. siklis, i. noviandri, and s. gandasasmita, “study of electropolimerization processes of pyrrole by cyclic voltammetric technique,” indonesian journal of chemistry, vol. 4, no. 2, pp. 117–124, 2004. [23] k. ngibad, a. mulyasuryani, and d. mardiana, “modification of screen-printed carbon electrodeby polypyrrole for determination of hydroquinone,” alchemy jurnal penelitian kimia, vol. 12, no. 1, pp. 36-49, 2016. [24] r. v manurung, e. d. kurniawan, j. hidayat, c. risdian, “desain dan fabrikasi elektroda biosensor: metode teknologi film tebal,” jurnal ilmiah elite elektro, vol. 3, no. 1, pp. 65–70, maret, 2012. [25] l. manjakkal, a. vilouras, and r. dahiya, “screen printed thick film reference electrodes for electrochemical sensing,” ieee sensors journal, vol. 18, no. 19, pp. 7779–7785, oct., 2018. [26] r. tomar and c. r sharma, “fabrication and characterization of conducting polymer composite,” int. journal on organic electronics, vol. 2, no. 3/4, pp. 1–8, oct, 2013. https://mev.lipi.go.id/ https://www.turc.or.id/wp-content/uploads/2018/06/bps_berita-resmi-statsitik_keadaan-ketenagakerjaan-indonesia-februari-2018.pdf https://www.turc.or.id/wp-content/uploads/2018/06/bps_berita-resmi-statsitik_keadaan-ketenagakerjaan-indonesia-februari-2018.pdf https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7234/5484 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7234/5484 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7234/5484 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7234/5484 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7234/5484 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://e-journal.biologi.lipi.go.id/index.php/berita_biologi/article/viewfile/744/516 https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://media.neliti.com/media/publications/85044-none-7144ea50.pdf https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://peraturan.bpk.go.id/home/details/112092/permenkes-no-32-tahun-2017 https://media.neliti.com/media/publications/173399-en-effect-of-npk-fertilizer-and-biochar-res.pdf https://media.neliti.com/media/publications/173399-en-effect-of-npk-fertilizer-and-biochar-res.pdf https://media.neliti.com/media/publications/173399-en-effect-of-npk-fertilizer-and-biochar-res.pdf https://media.neliti.com/media/publications/173399-en-effect-of-npk-fertilizer-and-biochar-res.pdf https://media.neliti.com/media/publications/173399-en-effect-of-npk-fertilizer-and-biochar-res.pdf https://doi.org/10.18196/pt.v10i1.9814 https://doi.org/10.18196/pt.v10i1.9814 https://doi.org/10.18196/pt.v10i1.9814 https://doi.org/10.18196/pt.v10i1.9814 https://journal.ipb.ac.id/index.php/jtep/article/view/7405/5756 https://journal.ipb.ac.id/index.php/jtep/article/view/7405/5756 https://journal.ipb.ac.id/index.php/jtep/article/view/7405/5756 https://journal.ipb.ac.id/index.php/jtep/article/view/7405/5756 https://dx.doi.org/10.21162/pakjas/20.9946 https://dx.doi.org/10.21162/pakjas/20.9946 https://dx.doi.org/10.21162/pakjas/20.9946 https://dx.doi.org/10.21162/pakjas/20.9946 https://www.academia.edu/42910480/monitoring_of_soil_nutrients_using_iot_for_optimizing_the_use_of_fertilizers_final_year_ug_student_loyola_institute_of_technology https://www.academia.edu/42910480/monitoring_of_soil_nutrients_using_iot_for_optimizing_the_use_of_fertilizers_final_year_ug_student_loyola_institute_of_technology https://www.academia.edu/42910480/monitoring_of_soil_nutrients_using_iot_for_optimizing_the_use_of_fertilizers_final_year_ug_student_loyola_institute_of_technology https://www.academia.edu/42910480/monitoring_of_soil_nutrients_using_iot_for_optimizing_the_use_of_fertilizers_final_year_ug_student_loyola_institute_of_technology https://dx.doi.org/10.1109/icsima.2017.8312001 https://dx.doi.org/10.1109/icsima.2017.8312001 https://dx.doi.org/10.1109/icsima.2017.8312001 https://dx.doi.org/10.1109/icsima.2017.8312001 https://dx.doi.org/10.1109/icsima.2017.8312001 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7216/5466 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7216/5466 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7216/5466 https://ojs.unud.ac.id/index.php/prosidingcsgteis2013/article/view/7216/5466 https://dx.doi.org/10.1109/smc.2014.6974457 https://dx.doi.org/10.1109/smc.2014.6974457 https://dx.doi.org/10.1109/smc.2014.6974457 https://dx.doi.org/10.1109/smc.2014.6974457 https://dx.doi.org/10.13140/rg.2.1.5126.2966 https://dx.doi.org/10.13140/rg.2.1.5126.2966 https://dx.doi.org/10.13140/rg.2.1.5126.2966 https://dx.doi.org/10.13140/rg.2.1.5126.2966 https://dx.doi.org/%2010.1016/j.solidstatesciences.2013.01.005 https://dx.doi.org/%2010.1016/j.solidstatesciences.2013.01.005 https://dx.doi.org/%2010.1016/j.solidstatesciences.2013.01.005 https://doi.org/10.1016/j.electacta.2011.11.097 https://doi.org/10.1016/j.electacta.2011.11.097 https://doi.org/10.1016/j.electacta.2011.11.097 https://doi.org/10.1016/j.electacta.2011.11.097 https://dx.doi.org/10.1155/2006/395391 https://dx.doi.org/10.1155/2006/395391 https://dx.doi.org/10.1155/2006/395391 https://dx.doi.org/10.1155/2006/395391 https://dx.doi.org/%2010.1109/shuser.2012.6268811 https://dx.doi.org/%2010.1109/shuser.2012.6268811 https://dx.doi.org/%2010.1109/shuser.2012.6268811 https://dx.doi.org/%2010.1109/shuser.2012.6268811 https://www.scitechnol.com/peer-review/electrically-conducting-polymers-6j7y.php?article_id=5814 https://www.scitechnol.com/peer-review/electrically-conducting-polymers-6j7y.php?article_id=5814 https://www.researchgate.net/publication/255960728_comparison_of_polyaniline_and_polypyrrole_based_humidity_sensors https://www.researchgate.net/publication/255960728_comparison_of_polyaniline_and_polypyrrole_based_humidity_sensors https://www.researchgate.net/publication/255960728_comparison_of_polyaniline_and_polypyrrole_based_humidity_sensors https://www.researchgate.net/publication/255960728_comparison_of_polyaniline_and_polypyrrole_based_humidity_sensors https://doi.org/10.1080/01932691.2016.1184096 https://doi.org/10.1080/01932691.2016.1184096 https://doi.org/10.1080/01932691.2016.1184096 https://doi.org/10.1080/01932691.2016.1184096 https://jurnal.ugm.ac.id/ijc/article/view/21864/14569 https://jurnal.ugm.ac.id/ijc/article/view/21864/14569 https://jurnal.ugm.ac.id/ijc/article/view/21864/14569 https://jurnal.ugm.ac.id/ijc/article/view/21864/14569 https://doi.org/10.20961/alchemy.12.1.938.36-49 https://doi.org/10.20961/alchemy.12.1.938.36-49 https://doi.org/10.20961/alchemy.12.1.938.36-49 https://doi.org/10.20961/alchemy.12.1.938.36-49 http://lipi.go.id/publikasi/desain-dan-fabrikasi-elektroda-biosensor-metode-teknologi-film-tebal/21191 http://lipi.go.id/publikasi/desain-dan-fabrikasi-elektroda-biosensor-metode-teknologi-film-tebal/21191 http://lipi.go.id/publikasi/desain-dan-fabrikasi-elektroda-biosensor-metode-teknologi-film-tebal/21191 https://dx.doi.org/10.1109/jsen.2018.2840349 https://dx.doi.org/10.1109/jsen.2018.2840349 https://dx.doi.org/10.1109/jsen.2018.2840349 https://dx.doi.org/10.5121/ijoe.2013.2401 https://dx.doi.org/10.5121/ijoe.2013.2401 https://dx.doi.org/10.5121/ijoe.2013.2401 introduction ii. materials and methods a. equipments and materials b. design of nitrate sensors c. sensitive membrane the fabrication process with thick film technology e. the electro polymerization/electroplating process f. electrode examination (nitrate sensor) the testing and characterizing of nitrate sensor performance iii. results and discussions a. the result of scanning electron microscopy (sem)energy dispersive x-ray spectoroscopy (eds) b. the electro polymerization process examinations c. the result of reference voltage testing the result of sensor performance testing iv. conclusion acknowledgement declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.73-84 2088-6985 / 2087-3379 ©2019 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015 (sinta 2). smart grid communication applications: measurement equipment and networks architecture for data and energy flow tinton dwi atmaja a, *, dian andriani b, rudi darussalam a a research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi bandung, gd 20, lt 2, bandung, west java, 40135 indonesia b research unit for clean technology, indonesian institute of sciences komp lipi bandung, gd 50, bandung, west java, 40135 indonesia received 13 september 2019; accepted 25 november 2019 abstract smart grid is an advanced two way data and energy flow capable of self-healing, adaptive, resilient, and sustainable with prediction capability of possible fault. this article aimed to disclose smart grid communication in a logical way to facilitate the understanding of each component function. the study was focused on the improvement, advantages, common used design, and possible feature of smart grid communication components. the results of the study divide the smart grid communication application into two main category i.e. measurement equipment and network architecture. measurement equipment consists of advance metering infrastructure, phasor measurement unit, intelligent electronic devices, and wide area measurement system. the network architecture is divided based on three hierarchies; local area network for 1 to 100 m with 100 kbps data rate, neighbour area network for 100 m to 10 km with 100 mbps data rate, and wide area network for up to 100 km with 1 gbps data rate. more information is provided regarding the routing protocol for each network from various available protocols. the final section presents the energy and data flow architecture for smart grid implementation based on the measurement equipment and the network suitability. this article is expected to provide a comprehensive guide and comparison surrounding the technologies supporting smart grid implementation especially on communication applications. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: smart grid application; phasor measurement unit; communication network; communication protocol; energy and data flow. i. introduction recent researches on smart grid have been focused on addressing readability, adaptability, and fault prediction issues [1]. further challenges on smart grid research should include demand handling, service quality, grid flexibility, power sustainability, end to end full control, market enabling, cost reduction, performance optimization, self-healing, and grid restoration [2]. the increase of distributed generation (dg) penetration brings an increased number of parameters including networks constrain, thermal overload, voltage limits, and hardwire connection complexities. communication application is the key component to provide reliable smart grid operation by facilitating a real-time connection for measuring, monitoring, and controlling the grid assets [3][4][5]. two way communications with high speed data rate in smart grid communication will give a dynamic infrastructure for power exchange [6][7][8]. developing a smart communication system and subsystem requires monitoring and metering capability which covers the entire domain from the generation up to distribution [9]. advanced metering infrastructure (ami) can be assumed as the upgraded version of the conventional automated meter reading and automated meter management. ami involves smart meter, communication network, and data management system [10]. phasor measurement unit (pmu) can also be considered as the upgrade of the conventional system. supervisory control and data acquisition (scada) played a significant role in the power system until the communication technology has evolved and the grid is demanding a fast unlimited data access at so many network node [11]. pmu deployment will lead to the * corresponding author. tel: +62-22-2503055 e-mail address: tinton_dwi@yahoo.com https://dx.doi.org/10.14203/j.mev.2019.v10.73-84 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.73-84 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.73-84&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 74 implementation of some technologies which cannot be handled properly by the conventional power delivery system, such as high-voltage direct currents (hvdcs) and intelligent electronic devices (ieds) [11]. pmu is also able to estimate the synchrophasor, frequency, and the rate of change of frequency (rocof or d f/dt) of the acquired voltage and/or current waveforms [12]. the common standards used by synchrophasor technology were ieee 1344, irig-b, ieee c37.118, and iec61850 [13][14]. pmu has been dedicated as the most effective measurement device for monitoring, control, and protection of the evolved power system in correspondence to its capability on addressing technological update and covering the geographical extension of the modern power system [15]. communication network should be the next focus after the measurement system. smart grid network should be classified in the typical payload, data sampling, latency, and reliability [16]. this study has divided the communication network basically by its data rate and coverage area [3][17]. routing development of each network classification had been explained to describe the interaction of each component in a proper way with respect to the various smart grid applications. the connection protocols have been categorized on the existing approach for local area network, neighbor area network, and wide area network. furthermore, open architecture with plug and play features should provide a better environment for smart sensor and control devices. this article aimed to disclose smart grid communication components to facilitate the understanding of the further function of each component. the result of the study provides a detail explanation of the technologies’ features, advantages, connectivity, and primary role in supporting smart grid implementation, especially on smart grid communication. ii. materials and methods the article focused on the smart grid communication components by presenting their improvement, advantages, commonly used design, and possible feature. the smart grid communication application is divided into its measurement equipment and network architecture. the measurement equipment consists of advance metering infrastructure, phasor measurement unit, and intelligent electronic devices. meanwhile, the network architecture is divided based on their hierarchy; namely local area network, neighbor area network, and wide area network. further information was provided regarding the routing protocol for each network. the final section was presenting the energy and data flow of smart grid implementation based on the communication application. iii. smart grid communication equipment a. advanced metering infrastructure the advanced metering infrastructure consists of several components which provide two way intelligent links from the consumers to the system management [18][19][20]. the infrastructures commonly consist of three segments; namely the consumer data collection devices, the system management, and a communication network as the connector. figure 1 shows the schematic representation of ami [2][21]. the implementation of ami is the first step to upgrade the conventional grid into the modern smart grid. it requires telecommunication system, wiring component, various standard, and numerous best practices. all the digitalized asset on the consumers will provide information for the system management to make an intelligent decision on the grid real-time condition. digitalize asset all over the grid will enhance the service that lead to significant benefit for the customer and the management. various supporting technology such as smart metering, han, utility application, etc. will enhance the two-way interactions among utilities, consumer, and the network. basically, ami acts as the main backbone for the information flow between the consumer and the utility grid. the infrastructure will monitor and control the power generation system, the storage data collection and analysis ami host management system end user data collection communication network data management electric meter gas meter water meter data transmisison network data storage wan nan/fan han/ban/ian figure 1. ami implementation schematic t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 75 units, data reception equipment, and perform a possible big data analysis. at the end user, smart metering devices can be combined with the power quality monitoring system to fasten the smart demand response for any power quality troubleshoots. within the correct range, remote connection and disconnection is considered as a possible implementation to minimize on-field personnel and reduce the operational cost. this infrastructure was also implemented not only for data storage but also as a back up strategy for possible attack or anomaly. it can be equipped with forecasting neural network to detect possible failure followed with self-healing capability performed from data management center. ami collected data provides granularity and timeliness information to improve asset management and operations. figure 2 shows ami feature presented on each side of the domain [21]. 1) ami subsystem ami assist the consumer portal layer to connect entirely with metering layer and also with the communication layer. all smart metering devices in the han and lan will be connected and controlled in a very intelligent step toward modern power grid. ami technology and interference is shown in figure 3 [21]. the infrastructure covers the communication network, smart metering devices, han-lan, gateways, local data concentrators, data center, and meter data management system. the final function of ami is to add the collected data into big data platforms. 2) ami communication technologies several communication technologies is available in the today’s market such as long term evolution (lte), lte-advanced, power line carrier (plc), general packet radio service (gprs), 802.22 wireless networking protocol, and zigbee. table 1 shows a comparison of some available communication technologies in correspondence with ami requirement [2]. although the comparison shows many advantages of lte application, the utility companies still consider the cost and the spectrum as the main reason of not using the lte. more modifications are encouraged to be implemented in the communication technology such as open standard on utility communication which can be lead to a better connection between communication systems. b. phasor measurement units pmu is employing a general time source to measure the electrical wave on the utility grid [22][23][24]. pmu basic component consists of the figure 2. ami features in each smart grid communication domain consumer side •consumption data collection •power loss •time-based pricing •net metering •power restoration •power quality monitoring •remote turn on/off operations •prepaid eletrification •energy tamper detection •load limitation •communications with other intelligent devices •goal: intelligent energy consumption decisions utility side •ami data collection •ami data analyzing •optimizing economics •operations and consumer service •instant feedback •notifying consumer outages •address utility grid deficiencies •utility grid automation •planning of asset maintenance •assest addition or replacement •goal: reliable and efficient utility grid operation communication network •facilitating various equipment: •power line carrier •copper •optical fiber •internet, or •wireless point •continuous interaction between the consumer and the utility •ranged data collection and communication •act as local concentrators for data gathering •goal: optimum data transmission from user to central server figure 3. ami subsystem technology and interferences consumer portal layer metering layer communication layer home area network der smart meter local area network smart meter der local control device local control device dms dms gateway communication ami board end mdms dms gateway consumer service t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 76 current phasor, bus voltage phasor, location information, converter, and phasor microprocessor as shown in figure 4 [11][21]. the current and the voltage signal are converted into digitalized ac waveforms. in the other segment, gps receiver sends the coordinate to the phasor locked oscillator and create a high-speed synchronized sampling with 1 ms precision. the current-voltage and the phasor locked the oscillator output to combine with the 16-bits a/d converter. pmu is able to quantify 50 hz ac waveforms (currents and voltages) at a common rate of 48 samples per cycle [25]. time synchronization permits synchronized immediate measurements over many types of remote measurement points scattered within the grid. the result of the measurement is known as synchrophasor. with synchrophasor as the metered value, pmus plays one of the most important role on measuring energy and data for the future power delivery systems. the most advantageous aspect of the pmu is the gps reference inclusion inside the unit. the time source is calibrated and synchronized into resultant time-stamped phasor that can be transmitted from various important cross points through the entire utility grid. with up to 120 samples per second, the user can visualize the whole grid in the precise angular among various locations. pmu mostly used to monitor and control the voltage around the wide area grid. pmu also prevent any possible blackout, mitigate potential congestion problem, and provide dynamic visibility into the source-consumer power system. with the increase of dg integration, pmu installation provides a real-time measurement system that covers the whole delivery system including generation, transmission, and distribution. additional utility monitoring systems consist of dynamic line rating technology, electronic instrument transformers, batteries, temperature sensors, conductor sensors, insulation contamination leakage, backscatter radios technology, and monitoring system for cb and current frequency. c. intelligent electronic devices monitoring process on the power system line basically performed by scada system based on collected data from substations. as the grid evolved, the scada system limitation to support ami and pmu has been covered by the inclusion of ied. ied is a microprocessor with the ability to exchange data and process a control signal between devices in the grid. it is considered as the prime supporter of any remote power management, including pmu unit, on how they provide continuous real time synchronization [26][27][28]. ied configuration shown in figure 5 was aimed to improve monitoring, controlling, data acquisition, and data recording [21][29][30]. ied is mostly connected with global positioning system (gps) as further support to the pmu. ieds measures control signal, phase current/voltage, internal relay, and oscilloscopic data with three common different types: circuit breaker monitor (cbm), digital fault recorder (dfr) and digital protective relay (dpr). cbm is responsible for the monitoring of the circuit condition and acts as a determinant for opening and closing process. dfr is the device to capture and store a short duration events such as power spike, harmonic disorder, frequency anomaly, rms, and power factor disturbance. dpr was specifically designed for transmission line monitoring on possible fault or trip. dpr will respond to the surge on current, voltage, impedance, or frequency and inform it away to the substation. table 2 shows the available synchrophasor ied to support pmu on smart grid communication system [11]. d. wide area measurement systems wide area measurement systems (wams) is the final component to integrate ami and pmu [31][32][33]. most likely in similar concept with the present scada system, measurements of the grid table 1. comparison of the available communication technologies for ami parameter lte-a 3g (hspa+) plc 802.22 latency (ms) <5 <50 <10 <20 date rate (mbps) download/upload 1000/500 28/11 3/3 18/18 range (km) 100 10 5 100 main disadvantage limited number of supported connection alternate technology (bypass) needed at transformer no qos due to faulty spectrum sensing figure 4. basic components of a phasor measurement unit gps receiver phasor locked oscillator 16 bit ad conveter phasor microprocessor modem antialliasing filter synchrophasor output voltage phasor input (v) current phasor input (i) time and geo synchronization remote communication substation server protection monitoring metering control hmi office / home intelligent electronic device satellite time synchronisation figure 5. functional architecture of ied t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 77 system are conceded at a higher rate (up to 5-60 samples per second). therefore, the system requires a wide area measurement which can perform continuous and simultaneous real-time information rendering [34][35]. more or less, wams was aiming to improve the grid performance by stability assessment, fault detection, remedial control actions and supporting more accurate state estimation [36][37]. figure 6 shows the common wams architecture which deploys pmus, pdcs, super pdcs (regional pdcs), and communication protocol [11]. pmu send table 2. commercial syncrophasor-based ieds company ied application abb pvi-pmu (power management unit) photovoltaic system monitoring, active and reactive power control res670 2.0 (relion 670 & 650 series) power system protection and control psguard scada/ems integration and communication, power system monitoring general electric, grid solutions micom p40 agile feeder management eaton geargard conditional remote monitoring and early failure warning solutions real-time monitoring, statistical analysis, and condition-based maintenance decisions mehta tec data fault recorder (dfr)/disturbance monitoring equipment (dme)/pmu online disturbance monitoring and data archiving macrodyne 1690 phasor measurement systems for real-time data acquisition and control 1692 integrated recording units for transient fault and long-term disturbance events 1698, 1698e satellite timing units for absolute time tagging and synchronous data sampling schweitzer engineering laboratories (sel) sel-2411 programmable automation controller sel-t400l line protection with simple configuration, accurate fault locating, and highresolution oscillography sel-411l line current di erential, distance, and directional overcurrent protection, comprehensive monitoring, advanced automation and communication, highaccuracy fault locating s&c electric company 6800 series control and manage distribution switches automatically power standards lab (psl) pqube (pmu) cyber-attacks detection, power consumption analysis, remotely understand commercial ac power grids, provide input for solar pv and storage control system development, simulation and data integration for solar planning tools, and short-term planning and operations siemens siguard pdp (phasor data processor) complete portfolio for network monitoring, power quality recording, fault recording, phasor measurement, and system software applications figure 6. wams architecture scada/ems super pdc pdc 1 pdc 2 ied ied pmu 1 pmu k pmu 1 pmu m pdc p ied pmu 1 pmu n sensor architecture sensor architecture sensor architecture on-line monitoring on-line monitoring on-line monitoring ied sensor architecture ie c 6 0 8 7 0 -5 -1 0 1 ieee c37-118 ie c 6 0 8 7 0 -5 -1 0 4 iee e c 37 -1 18 ieee c37-118 ie ee c 37 -1 18 ieee c37-118 ie ee c 37 -1 18 ieee c37-118 ie ee c 37 -1 18 ieee c37-118 on-line monitoring t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 78 voltage and current in phasor form to the local phase data concentrators (pdc) using ieee c37.118.2 or iec 61850-90-5 standards. pdc normally located in the primary substation where the collected data was analyzed [38]. pdcs are required to make a decision with a very low latency of 10– 100 ms. ied has shown to take an important part in this wams by integrating devices such as reclosers, switches, and capacitor banks so that pdcs or super pdcs will be able to protect and control the grid at the distribution or transmission level immediately [39]. future concept can use iec61850-90-5 to replace ieee c37.118.2 protocol [40]. iv. smart grid communication networks the designated communication network in smart grid concept is classified based on the coverage area and the rate speed (figure 7) [17]. there are three common classes; namely local network, neighbour network, and wide network. the local network can be found in the form of home area network (han), building area network (ban), or industrial area network (ian). these networks usually cover single customer with several local applications, such as home automation and building automation, to perform electrical data collection and measurement within the small radius area between 1 to 100 m. this application can be implemented without high frequency transmission system, performed at low cost and low power consumption, and also can be used conveniently. data rate requirement in this area was up to 100 kbps which sufficiently supported by wifi, zwave, zigbee, plc, bluetooth, or ethernet [41]. neighbour network is usually called neighbour area network (nan) or field area network (fan). at this scale, the applications have a more complex requirement such as smart metering, demand response, and distribution automation. data transmissions are required to cover a larger number of the customer which led to the deployment of data concentrator and small substation. the coverage of this network can be up to 10 km with a higher data rate between 100 kbps to 10 mbps. nan/fan applications can be implemented over zigbee mesh networks, wifi mesh networks, plc, as well as long distance wired and wireless technologies, such as wimax, cellular, digital subscriber line (dsl) and coaxial cable [42]. wide network commonly called wide area network (wan) which apply the wide-area controlling, monitoring and protection. wan requires a large number of higher frequency data points to allow stability control of a power system which can cover up to 100 km. required data rate should be 10 mbps to 1 gbps which needs a utility control center due to its high capacity and low latency. cellular, wimax, and satellite communication were highly recommended to provide redundant communications at critical transmission/distribution substation sites especially when the coverage of the network is a wide remote area. a comparison of various communication technologies that can support smart grid applications in terms of data rate and coverage distance is presented in table 3 [17]. a. local area network local area network usually limited to an individual or single user called home area network (han), building area network (ban), or industrial area network (ian) [43]. there always permission is given for the system to remotely control the digitalized appliance within the house or building. it also facilitates the communication between assets such as mobile phone, desktop computer, hvac, electric vehicle, etc. via wireless or by wire connection [44]. han/ban/ian is the front line communication system that collects real-time data continuously and the primary media to facilitate the remote control provided by the data management system. it detects the peak time of the load demand, connect one smart appliance to another smart metering. this network also manages to conduct continuous monitoring system that enables to do early detection of possible failure or blackout. it also controls the automation of high consuming energy system so that the user could conduct self-energy usage optimization which leads to reduce electricity cost. this network also includes web-based monitoring system, ami, and pmu. b. neighbour area network neighbour network commonly found in the form of neighbour area network (nan) or field area network (fan). nan/fan is a wireless or wired network consist of groups of individuals, system devices, buildings, or open area with digitalized assets; which cover a larger area than han/nan/ian [45]. most of the architecture usually focused on optimization of interoperability and integration between different domains within the smart grid. nan/fan is able to find power generation domain within its coverage, it is commonly equipped with market service and plant control center with potential transmission-distribution line domain. figure 7. smart grid communication hierarchy with data rate and coverage range requirement wan nan/fan han/ ban/ ian 1 -100 kbps 100 kbps -10 mbps 10 mbps – 1 gbps 1 – 100 m 100 m – 10 km 10 – 100 km han/ ban/ ian han/ ban/ ian nan/fan han/ ban/ ian han/ ban/ ian han/ ban/ ian t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 79 nan/fan is also considered as a substation connecting the local network with the wide network. it means that this network has quite large data storage to facilitate a large data collection system form the han/ban/ian. the neighbour network will connect many energy management systems, digitalized appliances, metering devices, more electric storages, and even consumer phevs. the connection to the consumer will primarily through the internet with the possible use of the large intranet. depend on the area coverage, this network can be subdivided into transmission-distribution system using iso/rto technology. therefore, this network is able to handle the utility of third party including billing system and larger early warning system. c. wide area networks (wan) wan is the largest geographical coverage network compared to local or neighbour network, it usually interconnects multiple ban/han/ian or nan/fan [46]. wan is commonly in the shape of point-to-point technology (pp), circuit-switched technology (cs), or packet-switched technology (ps). pp is a costly technology and usually in the form of the leased or dedicated line which is attached to the utility backbone and provided a secure line between the local domain. it usually on the state of normallyon to ensure continuous line between network nodes on specified distance. cs technology needs a callsetup to make an action on the grid. once the call has made, the data transfer will trigger the session and followed by engaging or disengaging a single or multiple domains. on-demand switched is usually a low speed response compared with the other technologies. the last technology is packet-switched which is the cheapest of all technologies due to it share a common infrastructure. despite having the best performance in communication quality, however, it will cause inconsistent bandwidth. v. smart grid communication routing protocol the goal of routing protocol is the reliability, security and qos of the network performance [3][47][48]. the protocol has been classified into three classes i.e. routing for local network (han/ban/ian), routing for neighbour network (nan/fan), and routing for wide network (wan). the breakdown of the routing protocol for each class can be found in figure 8 [3]. a. routing protocols for local network summary of routing protocols for the local network (han/ban/ian) can be found in table 4 based on the adaptation layer and network layer [3]. the use of a specific protocol will affect the operational cost, performance of the network and the local network architecture. b. routing protocols for neighbour network smart grid communications consist of several nan/fan with mostly hundreds of ami. nan routing protocol will ensure the collected data from the table 3. comparison of communication technologies for the smart grid technologies standard/ protocol theoretical data rate coverage range network han/ban/ian nan/fan wan wired communication technologies coaxial cable docsis 172 mbps up to 28 km ethernet 802.3x 10 mbps 10 gbps up to 100 m x x plc homeplug 14–200 mbps up to 200 m x narrowband 10–500 kbps up to 3 km x dsl adsl 1–8 mbps up to 5 km hdsl 2 mbps up to 3.6 km x vdsl 15–100 mbps up to 1.5 km fiber optic pon 155 mbps–2.5 gbps up to 60 km x wdm 40 gbps up to 100 km sonet/sdh 10 gbps up to 100 km x wireless communication technologies z-wave z-wave 40 kbps up to 30 m x bluetooth 802.15.1 721 kbps up to 100 m x zigbee zigbee 250 kbps up to 100 m x x zigbee pro 250 kbps up to 1600 m wifi 802.11x 2–600 mbps up to 100 m wimax 802.16 75 mbps up to 50 km wireless mesh various (e.g., rf mesh, 802.11, 802.15, 802.16) depending on selected protocols depending on deployment x x cellular 2g 14.4 kbps up to 50 km x x 2.5g 144 kbps 3g 2 mbps 3.5g 14 mbps 4g 100 mbps satellite satellite internet 1 mbps 100 6000 km x t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 80 access point tier can report safely to the backhaul distribution tier. routing challenge will vary based on the underlying communication. therefore, there are three common protocols: reliable routing [49][50], secure routing [51][52][53], and qos routing protocols [54]. the comparison of each routing protocols can be seen in table 5 [3]. c. routing protocols for wide network wide network is different from local and neighbour network since it most likely consists of a core network or a backhaul network. generally, wan routing protocol is handled by the public network such as the internet and private lines. fiber optic is the best offer to the required data rate and should be figure 8. routing protocol classification for smart grid communications table 4. summary of routing protocols for local network routing protocol adaptation layer data link network layer zigbee n/a csma/ca tree routing, on-demand mesh routing, source routing mesh under layer 2 mesh routing csma/ca n/a route over n/a csma/ca rpl routing wireless-hart n/a tdma graph and source routing isa100.11a n/a tdma, csma/ca, graph routing and source routing backbone routing z-wave n/a csma/ca source routing insteon n/a tdma simulcast table 5. routing protocol classification for nans routing protocol pointto point routing one-to many routing manyto one routing multipath scalable load balancing application dadr √ √ √ √ √ wireless ami hydro √ √ √ √ √ √ wireless ami timer based multipath diversity routing √ √ √ wireless ami, status management and monitoring pmr √ √ ami-plc routing for sg routing for hans routing for nans routing for wireless hans routing for plc hans routing for hybrid hans reliable routing for wireless nans reliable routing for plc nans secure routing for wireless hans qos routing for wireless nans zigbee routing ipv6 routing 6lowpan wirelesshart roting elhfr z wave routing isa100.11a routing dmpr adaptive channel state routing insteon plc-zigbee routing ipv6 rf-plc routing dadr hydro rpl ieee 802.11a routing timer based mutipatch delivery li et al bartoli et al routing adapted from wireless network routing specially designed from plc ipodv blr + gpsr igf + gprs bbr + gprs pmr li et al routing for wan reliable routing for wan ip/mpls internet / private line wi-max 4g gprs reliable routing nans t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 81 followed by ip/multi-protocol label switching (mpls) and metro ethernet. another option is to apply wimac, 4g, or gprs even though they depend on the quality of the physical layer, channels, radio, handoff, etc. the newest study showed that the deployment of multi-hop wireless wan can be a proprietary network within a single instalment which have a complete substation, gateway, and data metering devices. vi. smart grid data and energy flow architecture the energy flow has been completely covered by the conventional utility grid. nevertheless, the challenge on the smart grid implementation is covering the data flow within the entire grid. the first challenge is the digitalization of all the grid asset in order to be able to reach out the communication protocols. combination of energy flow and data flow will then increase the controllability, flexibility, and more adaptive response. the data and energy flow should be covering all the domain including power generation, transmission-distribution, and customers’ peripheral. figure 9 shows the architecture of data and energy flow in smart grid with a wide multi-port system network node [21][55]. the architecture presented in figure 9 covers the measurement equipment ami and pmu, and consisting of three layers communication network. local network mostly exists in the customer side which facilitates the control and monitoring of all digitalized appliances. local network also connects the ami to the energy management system (ems), energy storage system (ess), and possible use of plugin hybrid electric vehicle (phev). the connection with phev would introduce the concept of vehicle to grid (v2g) where the charge and discharge action will depend completely on the time and location. neighbour network would be consisting of at least two local networks, therefore, consisting of several ami and possible local dg. amis in the customer side had connected to the substation’s pmu in the distribution line, while each substation’s pmu will connect each other in the transmission line. moreover, the transmission line is the backbone network which unites the power generation side to the customer side. power generation could be a large scale power plant in a remote location or could be small size dg within local neigbourhood. each power plant would have its own substation, or multiple power plants covered by one substation. substations’ pmu at the power generation side will be connected to the backbone and coordinate with the pmus at the consumer side. these measurement devices and multi layers network contains different component with various characteristics and action. for example, dgs and load can connect or disconnect at any time without proper pattern. therefore smart grid data management center must play the role of multi-agent to ensure that every node can be controlled in a specific manner. every information provided by the amis and pmus will be processed at the center and provide a control output to each of grid’s digitalize asset. farsighted the large number of amis and pmus, it is figure 9. data and energy flow architecture in smart grid power generationtransmission and distributioncustomer n a n /f a n h a n /b a n /ia n w a n ess ami pmu phev ems energy flow data flow ess ami pmu phev ems substation substation pmu pmu substation pmu pmu pmu pmu substation data management center t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 82 recommended to adapt the cloud computing architecture to cover all the big data at the grid. cloud computing has served as an excellent method to handle a large volume of data in the coverage of all ami and pmu [56][57]. cloud computing can provide flexibility and scalable characteristic to cope with the data storage and vast transferable real-time data [58][59][60]. with the expanding area of the smart grid, cloud computing can easily adapt to present remote data storage, automatic updates, less utility cost, energy saving, and reduce human labor demand [61][62][63]. cloud computing architecture for smart grid designed by dileep g. [21] can be found in figure 10. this architecture can be adapted to create a cloud database which stores public and private information. each information class can be managed as three basic cloud services i.e. data as a service (daas), software as a service (saas), and infrastructure as a service (iaas). the analytic can perform energy analysis within the grid, reporting and monitoring the grid’s asset, and the most important is the visualization of the grid. vii. conclusion this article presents an overview of the one key component of smart grid, the communication application including the related technologies. the study was done by conducting a review of its components, technologies, features, challenge, and advantages. it is known that efficiency, reliability, and security of interconnected devices are critical to enabling smart grid global implementation. the study explained various smart grid measurement technologies such as ami, pmu, ied, and wams followed by the description of smart grid network classification divided in three classes i.e. han/ban/ian, nan/fan, and wan. the ami and pmu were covering the measurement system and data collection while the ied and wams was covering the secure and reliable data transfer from the consumer to the data management center. han/ban/ian is a local network which facilitates smart grid from the end user platform at low 100 kbps data rate for the least 1 to 100 m, while nan/fan is doing the similar task at the larger coverage area which is up to 10 km for 10 mbps data rate. for the last, wan is the one covering the whole local and neighbour network by approximately 100 km at 1 gbps data rate. related technologies are including routing protocol for each network that considers the underlying communications medium, reliability, security, and qos. the primary function is to facilitate the measurement and monitoring process and then collect the data for the grid analysis at the data management center. this communication network will increase the flexibility to the attachment of dgs which will increase the usage of renewable energy. smart grid can be considered as a future technology to help environmental conservation and energy sustainability. it is expected that this article can offer a further understanding of communication network requirements for a complete smart grid implementation. acknowledgement the author would like to thank all researchers at research centre for electrical power and mechatronics and research unit for clean technology, indonesian institute of science for the completion of this study. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. figure 10. smart grid cloud architecture web portal access analytics energy analysis reporting/analytics visualization daas data management/ aggregation data optimization saas geospatial wheather prediction iaas storage web hosting network performance monitoring dr/backup high performance computing authentication and accreditation services data utilities energy production energy management asset management metering information remote power quality monitoring consumers bi-directional energy flow sensing and measuring private cloud public cloud firewall t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 83 conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] j. a. momoh, “smart grid design for efficient and flexible power networks operation and control,” in 2009 ieee/pes power systems conference and exposition, 2009, pp. 1–8. [2] r. rashed mohassel, a. fung, f. mohammadi, and k. raahemifar, “a survey on advanced metering infrastructure,” int. j. electr. power energy syst., vol. 63, pp. 473–484, dec. 2014. [3] n. saputro, k. akkaya, and s. uludag, “a survey of routing protocols for smart grid communications,” comput. networks, vol. 56, no. 11, pp. 2742–2771, jul. 2012. [4] m. erol-kantarci and h. t. mouftah, “energy-efficient information and communication infrastructures in the smart grid: a survey on interactions and open issues,” ieee commun. surv. tutorials, vol. 17, no. 1, pp. 179–197, 2015. [5] e. ancillotti, r. bruno, and m. conti, “the role of communication systems in smart grids: architectures, technical solutions and research challenges,” comput. commun., vol. 36, no. 17–18, pp. 1665–1697, nov. 2013. [6] j. naus, g. spaargaren, b. j. m. van vliet, and h. m. van der horst, “smart grids, information flows and emerging domestic energy practices,” energy policy, vol. 68, pp. 436–446, may 2014. [7] j. gao, y. xiao, j. liu, w. liang, and c. l. p. chen, “a survey of communication/networking in smart grids,” futur. gener. comput. syst., vol. 28, no. 2, pp. 391–404, feb. 2012. [8] n. kilic and v. c. gungor, “analysis of low power wireless links in smart grid environments,” comput. networks, vol. 57, no. 5, pp. 1192–1203, apr. 2013. [9] s. bruno, s. lamonaca, m. la scala, g. rotondo, and u. stecchi, “improving energy efficiency in a power park by the integration of a hydrogen steam reformer,” in 2009 asia-pacific power and energy engineering conference, 2009, pp. 1–8. [10] s. paul, m. s. rabbani, r. k. kundu, and s. m. r. zaman, “a review of smart technology (smart grid) and its features,” in 2014 1st international conference on non conventional energy (iconce 2014), 2014, pp. 200–203. [11] m. hojabri, u. dersch, a. papaemmanouil, and p. bosshart, “a comprehensive survey on phasor measurement unit applications in distribution systems,” energies, vol. 12, no. 23, p. 4552, nov. 2019. [12] i. power and e. society, c37.118.1-2011 ieee standard for synchrophasor measurements for power systems, vol. 2011, no. december. 2011. [13] k. e. martin et al., “exploring the ieee standard c37.118-2005 synchrophasors for power systems,” ieee trans. power deliv., 2008. [14] v. vyatkin, g. zhabelova, n. higgins, k. schwarz, and n.-k. c. nair, “towards intelligent smart grid devices with iec 61850 interoperability and iec 61499 open control architecture,” in ieee pes t&d 2010, 2010, pp. 1–8. [15] d. k. mohanta, c. murthy, and d. sinha roy, “a brief review of phasor measurement units as sensors for smart grid,” electr. power components syst., vol. 44, no. 4, pp. 411–425, feb. 2016. [16] m. jarrah, m. jaradat, y. jararweh, m. al-ayyoub, and a. bousselham, “a hierarchical optimization model for energy data flow in smart grid power systems,” inf. syst., vol. 53, pp. 190–200, oct. 2015. [17] m. kuzlu, m. pipattanasomporn, and s. rahman, “communication network requirements for major smart grid applications in han, nan and wan,” comput. networks, vol. 67, pp. 74–88, jul. 2014. [18] i.-k. yang, n.-j. jung, and y.-i. kim, “status of advanced metering infrastructure development in korea,” in 2009 transmission & distribution conference & exposition: asia and pacific, 2009, pp. 1–3. [19] g. lópez, j. i. moreno, h. amarís, and f. salazar, “paving the road toward smart grids through large-scale advanced metering infrastructures,” electr. power syst. res., vol. 120, pp. 194–205, mar. 2015. [20] d. wang, z. tao, j. zhang, and a. a. abouzeid, “rpl based routing for advanced metering infrastructure in smart grid,” in 2010 ieee international conference on communications workshops, 2010, pp. 1–6. [21] g. dileep, “a survey on smart grid technologies and applications,” renew. energy, vol. 146, pp. 2589–2625, available online 23 august 2010. [22] a. ahmadi, y. alinejad-beromi, and m. moradi, “optimal pmu placement for power system observability using binary particle swarm optimization and considering measurement redundancy,” expert syst. appl., vol. 38, no. 6, pp. 7263–7269, jun. 2011. [23] f. aminifar, a. khodaei, m. fotuhi-firuzabad, and m. shahidehpour, “contingency-constrained pmu placement in power networks,” ieee trans. power syst., vol. 25, no. 1, pp. 516–523, feb. 2010. [24] d. j. brueni and l. s. heath, “the pmu placement problem,” siam j. discret. math., vol. 19, no. 3, pp. 744–761, jan. 2005. [25] s. das, d. ghosh, t. ghose, and d. k. mohanta, “simulation of wide area measurement system with optimal phasor measurement unit location,” in 2014 international conference on signal processing and integrated networks (spin), 2014, pp. 226–230. [26] i.-h. lim and t. s. sidhu, “design of a backup ied for iec 61850based substation,” ieee trans. power deliv., vol. 28, no. 4, pp. 2048–2055, oct. 2013. [27] l. zhu, d. shi, and x. duan, “standard function blocks for flexible ied in iec 61850-based substation automation,” ieee trans. power deliv., vol. 26, no. 2, pp. 1101–1110, apr. 2011. [28] u. c. netto, d. de castro grillo, i. d. lonel, e. l. pellini, and d. v. coury, “an ann based forecast for ied network management using the iec61850 standard,” electr. power syst. res., vol. 130, pp. 148–155, jan. 2016. [29] i.-h. lim and t. s. sidhu, “a new local backup scheme considering simultaneous faults of protection ieds in an iec 61850-based substation,” int. j. electr. power energy syst., vol. 77, pp. 151–157, may 2016. [30] t.-h. yeh, s.-c. hsu, c.-k. chung, and m.-s. lin, “conformance test for ieds based on iec 61850 communication protocol,” j. power energy eng., vol. 03, no. 04, pp. 289–296, 2015. [31] d. bhor, k. angappan, and k. m. sivalingam, “network and power-grid co-simulation framework for smart grid wide-area monitoring networks,” j. netw. comput. appl., vol. 59, pp. 274– 284, jan. 2016. [32] t. zseby and j. fabini, “security challenges for wide area monitoring in smart grids,” e i elektrotechnik und informationstechnik, vol. 131, no. 3, pp. 105–111, may 2014. [33] i. albizu, e. fernandez, p. eguia, e. torres, and a. j. mazon, “tension and ampacity monitoring system for overhead lines,” ieee trans. power deliv., vol. 28, no. 1, pp. 3–10, jan. 2013. [34] p. hering, p. janecek, and e. janecek, “on-line ampacity monitoring from phasor measurements,” ifac proc. vol., vol. 47, no. 3, pp. 3164–3169, 2014. [35] r. g. olsen and k. s. edwards, “closure on ‘a new method for real-time monitoring of high voltage transmission line conductor sag,’” ieee trans. power deliv., vol. 18, no. 4, pp. 1598–1599, oct. 2003. [36] a. ashok, a. hahn, and m. govindarasu, “cyber-physical security of wide-area monitoring, protection and control in a smart grid environment,” j. adv. res., vol. 5, no. 4, pp. 481–489, jul. 2014. [37] y. mitani, t. kudo, a. satake, and k. h. basri, “monitoring the wide area power system dynamics by phasor measurement units based on campus wams strategy,” ifac proc. vol., vol. 47, no. 3, pp. 2273–2278, 2014. [38] c. efthymiou and g. kalogridis, “smart grid privacy via anonymization of smart metering data,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 238–243. [39] a. g. phadke and b. kasztenny, “synchronized phasor and frequency measurement under transient conditions,” ieee trans. power deliv., vol. 24, no. 1, pp. 89–95, jan. 2009. [40] r. i. müller and m. j. booysen, “a water flow meter for smart metering applications,” in the 9th south african conference on computational and applied mechanics, sacam2014, 2014. [41] w. wang, y. xu, and m. khanna, “a survey on the communication architectures in smart grid,” comput. networks, vol. 55, no. 15, pp. 3604–3629, oct. 2011. [42] a. aggarwal, s. kunta, and p. k. verma, “a proposed communications infrastructure for the smart grid,” in 2010 innovative smart grid technologies (isgt), 2010, pp. 1–5. [43] v. c. gungor et al., “smart grid technologies: communication technologies and standards,” ieee trans. ind. informatics, vol. 7, no. 4, pp. 529–539, nov. 2011. [44] delphine, b. w. jang, y. s. shin, s. t. kang, and j. s. choi, “design https://doi.org/10.1109/psce.2009.4840074 https://doi.org/10.1109/psce.2009.4840074 https://doi.org/10.1109/psce.2009.4840074 https://doi.org/10.1016/j.ijepes.2014.06.025 https://doi.org/10.1016/j.ijepes.2014.06.025 https://doi.org/10.1016/j.ijepes.2014.06.025 https://doi.org/10.1016/j.comnet.2012.03.027 https://doi.org/10.1016/j.comnet.2012.03.027 https://doi.org/10.1016/j.comnet.2012.03.027 https://doi.org/10.1109/comst.2014.2341600 https://doi.org/10.1109/comst.2014.2341600 https://doi.org/10.1109/comst.2014.2341600 https://doi.org/10.1109/comst.2014.2341600 https://doi.org/10.1016/j.comcom.2013.09.004 https://doi.org/10.1016/j.comcom.2013.09.004 https://doi.org/10.1016/j.comcom.2013.09.004 https://doi.org/10.1016/j.comcom.2013.09.004 https://doi.org/10.1016/j.enpol.2014.01.038 https://doi.org/10.1016/j.enpol.2014.01.038 https://doi.org/10.1016/j.enpol.2014.01.038 https://doi.org/10.1016/j.future.2011.04.014 https://doi.org/10.1016/j.future.2011.04.014 https://doi.org/10.1016/j.future.2011.04.014 https://doi.org/10.1016/j.comnet.2012.12.009 https://doi.org/10.1016/j.comnet.2012.12.009 https://doi.org/10.1016/j.comnet.2012.12.009 https://doi.org/10.1109/appeec.2009.4918425 https://doi.org/10.1109/appeec.2009.4918425 https://doi.org/10.1109/appeec.2009.4918425 https://doi.org/10.1109/appeec.2009.4918425 https://doi.org/10.1109/iconce.2014.6808719 https://doi.org/10.1109/iconce.2014.6808719 https://doi.org/10.1109/iconce.2014.6808719 https://doi.org/10.1109/iconce.2014.6808719 https://doi.org/10.3390/en12234552 https://doi.org/10.3390/en12234552 https://doi.org/10.3390/en12234552 https://doi.org/10.3390/en12234552 https://doi.org/10.1109/ieeestd.2011.6111219 https://doi.org/10.1109/ieeestd.2011.6111219 https://doi.org/10.1109/ieeestd.2011.6111219 https://doi.org/10.1109/tpwrd.2007.916092 https://doi.org/10.1109/tpwrd.2007.916092 https://doi.org/10.1109/tpwrd.2007.916092 https://doi.org/10.1109/tdc.2010.5484272 https://doi.org/10.1109/tdc.2010.5484272 https://doi.org/10.1109/tdc.2010.5484272 https://doi.org/10.1109/tdc.2010.5484272 https://doi.org/10.1080/15325008.2015.1117538 https://doi.org/10.1080/15325008.2015.1117538 https://doi.org/10.1080/15325008.2015.1117538 https://doi.org/10.1016/j.is.2014.12.003 https://doi.org/10.1016/j.is.2014.12.003 https://doi.org/10.1016/j.is.2014.12.003 https://doi.org/10.1016/j.is.2014.12.003 https://doi.org/10.1016/j.comnet.2014.03.029 https://doi.org/10.1016/j.comnet.2014.03.029 https://doi.org/10.1016/j.comnet.2014.03.029 https://doi.org/10.1016/j.comnet.2014.03.029 https://doi.org/10.1109/td-asia.2009.5356847 https://doi.org/10.1109/td-asia.2009.5356847 https://doi.org/10.1109/td-asia.2009.5356847 https://doi.org/10.1109/td-asia.2009.5356847 https://doi.org/10.1016/j.epsr.2014.05.006 https://doi.org/10.1016/j.epsr.2014.05.006 https://doi.org/10.1016/j.epsr.2014.05.006 https://doi.org/10.1016/j.epsr.2014.05.006 https://doi.org/10.1109/iccw.2010.5503924 https://doi.org/10.1109/iccw.2010.5503924 https://doi.org/10.1109/iccw.2010.5503924 https://doi.org/10.1109/iccw.2010.5503924 https://doi.org/10.1016/j.renene.2019.08.092 https://doi.org/10.1016/j.renene.2019.08.092 https://doi.org/10.1016/j.renene.2019.08.092 https://doi.org/10.1016/j.eswa.2010.12.025 https://doi.org/10.1016/j.eswa.2010.12.025 https://doi.org/10.1016/j.eswa.2010.12.025 https://doi.org/10.1016/j.eswa.2010.12.025 https://doi.org/10.1016/j.eswa.2010.12.025 https://doi.org/10.1109/tpwrs.2009.2036470 https://doi.org/10.1109/tpwrs.2009.2036470 https://doi.org/10.1109/tpwrs.2009.2036470 https://doi.org/10.1109/tpwrs.2009.2036470 https://doi.org/10.1137/s0895480103432556 https://doi.org/10.1137/s0895480103432556 https://doi.org/10.1109/spin.2014.6776952 https://doi.org/10.1109/spin.2014.6776952 https://doi.org/10.1109/spin.2014.6776952 https://doi.org/10.1109/spin.2014.6776952 https://doi.org/10.1109/spin.2014.6776952 https://doi.org/10.1109/tpwrd.2013.2258686 https://doi.org/10.1109/tpwrd.2013.2258686 https://doi.org/10.1109/tpwrd.2013.2258686 https://doi.org/10.1109/tpwrd.2010.2091154 https://doi.org/10.1109/tpwrd.2010.2091154 https://doi.org/10.1109/tpwrd.2010.2091154 https://doi.org/10.1016/j.epsr.2015.08.026 https://doi.org/10.1016/j.epsr.2015.08.026 https://doi.org/10.1016/j.epsr.2015.08.026 https://doi.org/10.1016/j.epsr.2015.08.026 https://doi.org/10.1016/j.ijepes.2015.11.024 https://doi.org/10.1016/j.ijepes.2015.11.024 https://doi.org/10.1016/j.ijepes.2015.11.024 https://doi.org/10.1016/j.ijepes.2015.11.024 https://doi.org/10.4236/jpee.2015.34039 https://doi.org/10.4236/jpee.2015.34039 https://doi.org/10.4236/jpee.2015.34039 https://doi.org/10.1016/j.jnca.2015.06.016 https://doi.org/10.1016/j.jnca.2015.06.016 https://doi.org/10.1016/j.jnca.2015.06.016 https://doi.org/10.1016/j.jnca.2015.06.016 https://doi.org/10.1007/s00502-014-0203-3 https://doi.org/10.1007/s00502-014-0203-3 https://doi.org/10.1007/s00502-014-0203-3 https://doi.org/10.1109/tpwrd.2012.2213308 https://doi.org/10.1109/tpwrd.2012.2213308 https://doi.org/10.1109/tpwrd.2012.2213308 https://doi.org/10.3182/20140824-6-za-1003.02592 https://doi.org/10.3182/20140824-6-za-1003.02592 https://doi.org/10.3182/20140824-6-za-1003.02592 https://doi.org/10.1109/tpwrd.2003.817762 https://doi.org/10.1109/tpwrd.2003.817762 https://doi.org/10.1109/tpwrd.2003.817762 https://doi.org/10.1109/tpwrd.2003.817762 https://doi.org/10.1016/j.jare.2013.12.005 https://doi.org/10.1016/j.jare.2013.12.005 https://doi.org/10.1016/j.jare.2013.12.005 https://doi.org/10.1016/j.jare.2013.12.005 https://doi.org/10.3182/20140824-6-za-1003.00771 https://doi.org/10.3182/20140824-6-za-1003.00771 https://doi.org/10.3182/20140824-6-za-1003.00771 https://doi.org/10.3182/20140824-6-za-1003.00771 https://doi.org/10.1109/smartgrid.2010.5622050 https://doi.org/10.1109/smartgrid.2010.5622050 https://doi.org/10.1109/smartgrid.2010.5622050 https://doi.org/10.1109/smartgrid.2010.5622050 https://doi.org/10.1109/tpwrd.2008.2002665 https://doi.org/10.1109/tpwrd.2008.2002665 https://doi.org/10.1109/tpwrd.2008.2002665 https://scholar.sun.ac.za/handle/10019.1/85908 https://scholar.sun.ac.za/handle/10019.1/85908 https://scholar.sun.ac.za/handle/10019.1/85908 https://doi.org/10.1016/j.comnet.2011.07.010 https://doi.org/10.1016/j.comnet.2011.07.010 https://doi.org/10.1016/j.comnet.2011.07.010 https://doi.org/10.1109/isgt.2010.5434764 https://doi.org/10.1109/isgt.2010.5434764 https://doi.org/10.1109/isgt.2010.5434764 https://doi.org/10.1109/tii.2011.2166794 https://doi.org/10.1109/tii.2011.2166794 https://doi.org/10.1109/tii.2011.2166794 https://doi.org/10.1109/icact.2014.6778950 t. d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 73-84 84 and implementation of building energy management system with quality of experience power scheduling model to prevent the blackout in smart grid network,” in 16th international conference on advanced communication technology, 2014, pp. 208–211. [45] m. n. o. sadiku and m. ilyas, “local area networks,” in simulation of local area networks, crc press, 2018, pp. 1–16. [46] s. bera, s. misra, and j. j. p. c. rodrigues, “cloud computing applications for smart grid: a survey,” ieee trans. parallel distrib. syst., vol. 26, no. 5, pp. 1477–1494, may 2015. [47] t. iwao et al., “dynamic data forwarding in wireless mesh networks,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 385–390. [48] j.-s. jung, k.-w. lim, j.-b. kim, y.-b. ko, y. kim, and s.-y. lee, “improving ieee 802.11s wireless mesh networks for reliable routing in the smart grid infrastructure,” in 2011 ieee international conference on communications workshops (icc), 2011, pp. 1–5. [49] s. dawson-haggerty, a. tavakoli, and d. culler, “hydro: a hybrid routing protocol for low-power and lossy networks,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 268–273. [50] h. gharavi and b. hu, “multigate communication network for smart grid,” proc. ieee, vol. 99, no. 6, pp. 1028–1045, jun. 2011. [51] f. li, b. luo, and p. liu, “secure information aggregation for smart grids using homomorphic encryption,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 327–332. [52] a. bartoli, j. hernandez-serrano, m. soriano, m. dohler, a. kountouris, and d. barthel, “secure lossless aggregation for smart grid m2m networks,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 333–338. [53] t. gamer, l. völker, and m. zitterbart, “differentiated security in wireless mesh networks,” secur. commun. networks, vol. 4, no. 3, pp. 257–266, mar. 2011. [54] h. li and w. zhang, “qos routing in smart grid,” in 2010 ieee global telecommunications conference globecom 2010, 2010, pp. 1–6. [55] y. kabalci, “a survey on smart metering and smart grid communication,” renew. sustain. energy rev., vol. 57, pp. 302– 318, may 2016. [56] s. rusitschka, k. eger, and c. gerdes, “smart grid data cloud: a model for utilizing cloud computing in the smart grid domain,” in 2010 first ieee international conference on smart grid communications, 2010, pp. 483–488. [57] m. yigit, v. c. gungor, and s. baktir, “cloud computing for smart grid applications,” comput. networks, vol. 70, pp. 312–329, sep. 2014. [58] i. mezgár and u. rauschecker, “the challenge of networked enterprises for cloud computing interoperability,” comput. ind., vol. 65, no. 4, pp. 657–674, may 2014. [59] q. hu, f. li, and c. chen, “a smart home test bed for undergraduate education to bridge the curriculum gap from traditional power systems to modernized smart grids,” ieee trans. educ., vol. 58, no. 1, pp. 32–38, feb. 2015. [60] d. li and s. k. jayaweera, “distributed smart-home decisionmaking in a hierarchical interactive smart grid architecture,” ieee trans. parallel distrib. syst., vol. 26, no. 1, pp. 75–84, jan. 2015. [61] m. mital, a. k. pani, s. damodaran, and r. ramesh, “cloud based management and control system for smart communities: a practical case study,” comput. ind., vol. 74, pp. 162–172, dec. 2015. [62] a. anwar and a. mahmood, “cyber security of smart grid infrastructure,” in the state of the art in intrusion prevention and detection, auerbach publications, 2014, pp. 139–154. [63] v. ananda kumar, k. k. pandey, and d. k. punia, “cyber security threats in the power sector: need for a domain specific regulatory framework in india,” energy policy, vol. 65, pp. 126– 133, feb. 2014. https://doi.org/10.1109/icact.2014.6778950 https://doi.org/10.1109/icact.2014.6778950 https://doi.org/10.1109/icact.2014.6778950 https://doi.org/10.1109/icact.2014.6778950 https://doi.org/10.1109/icact.2014.6778950 https://doi.org/10.1201/9781351076630-1 https://doi.org/10.1201/9781351076630-1 https://doi.org/10.1109/tpds.2014.2321378 https://doi.org/10.1109/tpds.2014.2321378 https://doi.org/10.1109/tpds.2014.2321378 https://doi.org/10.1109/smartgrid.2010.5622074 https://doi.org/10.1109/smartgrid.2010.5622074 https://doi.org/10.1109/smartgrid.2010.5622074 https://doi.org/10.1109/iccw.2011.5963578 https://doi.org/10.1109/iccw.2011.5963578 https://doi.org/10.1109/iccw.2011.5963578 https://doi.org/10.1109/iccw.2011.5963578 https://doi.org/10.1109/iccw.2011.5963578 https://doi.org/10.1109/smartgrid.2010.5622053 https://doi.org/10.1109/smartgrid.2010.5622053 https://doi.org/10.1109/smartgrid.2010.5622053 https://doi.org/10.1109/smartgrid.2010.5622053 https://doi.org/10.1109/jproc.2011.2123851 https://doi.org/10.1109/jproc.2011.2123851 https://doi.org/10.1109/smartgrid.2010.5622064 https://doi.org/10.1109/smartgrid.2010.5622064 https://doi.org/10.1109/smartgrid.2010.5622064 https://doi.org/10.1109/smartgrid.2010.5622064 https://doi.org/10.1109/smartgrid.2010.5622063 https://doi.org/10.1109/smartgrid.2010.5622063 https://doi.org/10.1109/smartgrid.2010.5622063 https://doi.org/10.1109/smartgrid.2010.5622063 https://doi.org/10.1002/sec.163 https://doi.org/10.1002/sec.163 https://doi.org/10.1002/sec.163 https://doi.org/10.1109/glocom.2010.5683884 https://doi.org/10.1109/glocom.2010.5683884 https://doi.org/10.1109/glocom.2010.5683884 https://doi.org/10.1016/j.rser.2015.12.114 https://doi.org/10.1016/j.rser.2015.12.114 https://doi.org/10.1016/j.rser.2015.12.114 https://doi.org/10.1109/smartgrid.2010.5622089 https://doi.org/10.1109/smartgrid.2010.5622089 https://doi.org/10.1109/smartgrid.2010.5622089 https://doi.org/10.1109/smartgrid.2010.5622089 https://doi.org/10.1016/j.comnet.2014.06.007 https://doi.org/10.1016/j.comnet.2014.06.007 https://doi.org/10.1016/j.comnet.2014.06.007 https://doi.org/10.1016/j.compind.2014.01.017 https://doi.org/10.1016/j.compind.2014.01.017 https://doi.org/10.1016/j.compind.2014.01.017 https://doi.org/10.1109/te.2014.2321529 https://doi.org/10.1109/te.2014.2321529 https://doi.org/10.1109/te.2014.2321529 https://doi.org/10.1109/te.2014.2321529 https://doi.org/10.1109/tpds.2014.2308204 https://doi.org/10.1109/tpds.2014.2308204 https://doi.org/10.1109/tpds.2014.2308204 https://doi.org/10.1109/tpds.2014.2308204 https://doi.org/10.1016/j.compind.2015.06.009 https://doi.org/10.1016/j.compind.2015.06.009 https://doi.org/10.1016/j.compind.2015.06.009 https://doi.org/10.1016/j.compind.2015.06.009 https://doi.org/10.1201/b16390-9 https://doi.org/10.1201/b16390-9 https://doi.org/10.1201/b16390-9 https://doi.org/10.1016/j.enpol.2013.10.025 https://doi.org/10.1016/j.enpol.2013.10.025 https://doi.org/10.1016/j.enpol.2013.10.025 https://doi.org/10.1016/j.enpol.2013.10.025 mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.117-125 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications leonard rusli *, brilly nurhalim, rusman rusyadi mechatronics department, swiss german university the prominence tower alam sutera, tangerang, 15143, indonesia received 22 october 2021; accepted 8 december 2021; published online 31 december 2021 abstract the vision-based approach to mobile robot navigation is considered superior due to its affordability. this paper aims to design and construct an autonomous mobile robot with a vision-based system for outdoor navigation. this robot receives inputs from camera and ultrasonic sensor. the camera is used to detect vanishing points and obstacles from the road. the vanishing point is used to detect the heading of the road. lines are extracted from the environment using a canny edge detector and houghline transforms from opencv to navigate the system. then, removed lines are processed to locate the vanishing point and the road angle. a low pass filter is then applied to detect a vanishing point better. the robot is tested to run in several outdoor conditions such as asphalt roads and pedestrian roads to follow the detected vanishing point. by implementing a simple blob detector from opencv and ultrasonic sensor module, the obstacle's position in front of the robot is detected. the test results show that the robot can avoid obstacles while following the heading of the road in outdoor environments. vision-based vanishing point detection is successfully applied for outdoor applications of autonomous mobile robot navigation. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: houghline transform (houghlinep); road lines detection; simple blob detector; vanishing point determination. i. introduction the development of robotics has brought many advantages to human life, such as replacing humans to do complex tasks, dealing with dangerous materials, and even exploring places beyond human capability. a mobile robot is one of the most common examples of this usage of robotics. the navigation of a mobile robot is an essential part of an autonomous system. there has been tremendous progress in autonomous navigation for indoor environments in the past decades. many types of sensors are used in the indoor autonomous navigation system, such as ultrasonic sensors and a laser range finder (lidar) such as ones made by velodyne. the difficulty with velodyne systems is their high price due to the lack of volume production. a vision-based approach will be a more economical alternative. one way to find a robot's heading is to use a memorized route that is learned during the teachmode phase of robot preparation [1]. this method requires a robust recognition of the vision features used, which becomes a significant challenge in a dynamic environment with moving obstacles such as pedestrian roads. road signs can be recognized with digital image processing easier than road appearances [2]. road appearances can be recognized using color histograms and simplifying the road shape like a triangle. however, the triangle assumption is often no longer valid when road shapes are mixed with road signs and pedestrians. one way to do road recognition is by color-based contrast and segmentation between the road and the boundary landscape. however, vanishing point detection and voting often delay and lag processing time. as long as the processing time is faster than the camera frame rate (30 hz), real-time processing is achieved. one way to perform real-time processing is by using regional division and angle limitation [3]. another effort to speed this up using a contourlet texture detector (ctd) has been attempted to speed up pixel detection and given a voting weight for processing efficiency [4]. * corresponding author. tel: +628111041614; fax: +62-2129779598 e-mail address: leonard.rusli@sgu.ac.id https://dx.doi.org/10.14203/j.mev.2021.v12.117-125 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.117-125 https://dx.doi.org/10.14203/j.mev.2021.v12.117-125 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.117-125&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:leonard.rusli@sgu.ac.id l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 118 vanishing point detection in the unstructured road that lacks road markings is more challenging and requires more complex background suppression and an effective voting strategy [5]. some previous work tries to circumvent the need for a geometric feature-based detection method by doing motionbased methods of vanishing point detection. motion is detected by observing optical flows of image points that converge on the focus of expansion [6][7] or alternatively a texture-based method can also be used [8]. this method can be superior for unstructured roads as well. road segmentation methods using dark channel-based image segmentation also tend to be fast. the accuracy is further improved by combining this with vanishing point voting strategies [9]. a neural network-based vanishing point recognition method has also been done that significantly boosts the point proposals with iterative optimization [10]. convolutional neural network (cnn) classification problem approach to detect vanishing point is attempted using google street-view image dataset as the training set. the results show that superior accuracy is achieved compared to algorithmic vanishing point detector [11]. the detection of the vanishing point in the image as used by several authors [12][13]. these authors used converging edges and textures to decide the most possible vanishing point. another author attempted to improve the vanishing point detection using an algorithm that uses long and robust contour segments. the road is modeled using a group of lines instead of rigid triangular lines [14][15]. straight segments in the edge map are recognized using hough transform available in opencv [16]. this results in a more robust algorithm. this approach is the chosen path to develop in this paper. to navigate the robot in an outdoor environment, a different method is needed because the outdoor environment has far fewer surrounding walls, reducing the effectiveness of the sensors. one way is to manually steer the robot through predefined waypoints, and the robot will follow the predefined waypoints while avoiding obstacles. the other way is by detecting the road using a vision system. this method does not require manual driving and is not limited to a predefined path. some methods in detecting the road are called color histogram and vanishing point detection. this paper focuses on vanishing point detection to navigate the robot in outdoor environments. the overall system is described in figure 1. the autonomous mobile robot with a visionbased system for navigation in an outdoor environment receives inputs from camera and ultrasonic sensor. the camera is used to detect vanishing points and obstacles from the road. the vanishing point is used to detect the heading of the road. the detected position of the obstacle is used to steer the robot to the vanishing point without collision. the ultrasonic sensor gives information about the actual distance from the robot to the obstacle by emitting an ultrasonic wave and measuring the time elapsed from the time of sending the signal until the time when receiving it. information of distance from the ultrasonic sensor is sent to the microcontroller. next, the data is processed in the mini-pc. the output data from the mini-pc which contains the movement information (forward, backward, turn left, or turn right) for the robot is sent to the microcontroller. the output of the microcontroller is pulse-width modulation (pwm) which is used to drive the motor via hbridge or motor driver. the mini-pc is monitored using a wireless module via a remote desktop connection. ii. materials and methods as seen in figure 2 the mechanical hardware is designed for navigation in an outdoor environment. the design comes up with 6 off-road wheels which make the robot able to go through any rough terrains and steep inclines. the design also comes up with a twist suspension to keep every wheel in contact with the ground for maximum traction. figure 1. system overview l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 119 to mount all the electrical components on the robot, the robot is also mounted with additional parts such as a camera bracket, components box, and ping sensor bracket which can be seen in figure 3. all the additional parts are made of acrylic. the reason why acrylic is chosen is that acrylic has less weight compared to steel. the cutting tool used to cut the acrylic is a laser cutting tool which also makes many shapes are easier to cut and also with much lower price. figure 4 describes the overview of how the algorithm of the program works. after initialization, first, the road is detected to find the road lines. the detected road lines are used to estimate the vanishing point. the vanishing point is converted to road angle. next, the obstacle in front of the robot is detected by using a simple blob detector. the distance to the obstacle is detected by using an ultrasonic sensor. the combination of road detection and obstacle detection makes a command to drive the motors. the connection between software at mini-pc to the microcontroller is done through firmata protocol communication. the vision system first takes the input image from the camera and performs edge detection through the input image. the output of edge detection is a binary image that contains edges. after the edges are detected on the image, the system performs line detection to estimate the possibility of lines created on the image. the line is detected by using probabilistic houghline transform (houghlinep). the output of houghlinep points belongs to one line. the illustration can be seen in figure 5. out of the detected lines, lateral lines are filtered out, meaning only lines that are in the longitudinal view will be taken into the next stage of processing. using the virtual horizon in the image, the lines that intersect with the virtual horizon become the candidate vanishing points. the edges of the road play the most dominant role. road lanes are not necessary, but they will certainly improve the detection accuracy. next, gradient filtering is applied to the detected lines. only lines that represent the road lines are kept. other lines such as lines from trees and walls are thrown away. the gradient filtering is illustrated in figure 6. by calculating the d variable, each of the two lines can be detected whether they are going to intersect each other at some point or not. if d is equal to zero, the lines are parallel and will not intersect each other. on the other hand, if d is not equal to zero, it means that the lines are going to intersect each other at some point. the distance d is calculated from the coordinates 𝑥1, 𝑦1 thru 𝑥4, 𝑦4 figure 2. fully constructed autonomous mobile robot for outdoor navigation figure 3. (a) component box; (b) camera bracket; and (c) ping sensor bracket figure 4. software design overview figure 6. gradient filtering figure 5. points of the detected line by using houghlinep l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 120 which the coordinates of the end points of the lines using equation (1) and illustrated in figure 7. 𝑑 = (𝑦2 − 𝑦1). (𝑥4 − 𝑥3) − (𝑦4 − 𝑦3). (𝑥2 − 𝑥1) (1) when d is not equal to zero, the system calculates the intersecting point (𝑥0, 𝑦0) of two lines by using equation (2). the intersection point represents the vanishing point of the road lines. knowing where the vanishing point is, the system can estimate the road angle to navigate the robot next. the detected road angle can be seen in figure 8. the obstacle in front of the robot is detected by using a simple blob detector and ultrasonic sensor. the input image is converted into grayscale. next, the input image is thresholded with parameters of minthreshold and maxthreshold from a simple blob detector. the output of the thresholding is a binary image. the white pixels in the binary image are grouped and called binary blobs. the center of each binary blob is calculated and blobs located closer than mindistbetweenblobs are merged. the center and radius of newly merged blobs are calculated again and returned as key points. every time there is a blob or obstacle, the simple blob detector calculates the position of the obstacle (𝑥, 𝑦), and combined with an ultrasonic sensor, the distance to the obstacle is known. the algorithm is illustrated in figure 9. as seen in figure 9, (𝑥, 𝑦) is the position of the obstacle that is detected by the simple blob detector. leftpillar and rightpillar are the boundaries that indicate the detectable area of the obstacle. obstacles outside the leftpillar and rightpillar are not detected as an obstacle. leftlength is calculated by (x-leftpillar) and rightlength is calculated by (xrightpillar). next, the distance to the obstacle is detected by using an ultrasonic sensor. the detectable area from the ultrasonic sensor is from 10 cm to 400 cm. in this paper, the detectable area for the robot to make a turn is limited from 130 cm to 200 cm. if leftlength is bigger than rightlength and the distance is between 130 cm to 200 cm, it indicates that the obstacle is located on the left area. therefore, the robot has to go right. vice versa, if leftlength is smaller than rightlength and the distance is between 130 cm to 200 cm, it indicates that the obstacle is located in the right area. therefore, the robot has to go left. to control the motors, the value of pwm depends on the value of the road angle. the bigger the road angle, the bigger the pwm value. therefore, the figure 7. parallel lines (𝑑 = 0) and intersecting lines (𝑑 ≠ 0) figure 9. obstacle detection algorithm ⎩ ⎪ ⎨ ⎪ ⎧𝑥0 = [(𝑥2 − 𝑥1) ∗ (𝑥4 − 𝑥3) ∗ (𝑦3 − 𝑦1) + (𝑦2 − 𝑦1) ∗ (𝑥4 − 𝑥3) ∗ 𝑥1 − (𝑦4 − 𝑦3) ∗ (𝑥2 − 𝑥1) ∗ 𝑥3] 𝑑� 𝑦0 = [(𝑦2 − 𝑦1) ∗ (𝑦4 − 𝑦3) ∗ (𝑥3 − 𝑥1) + (𝑥2 − 𝑥1) ∗ (𝑦4 − 𝑦3) ∗ 𝑦1 − (𝑥4 − 𝑥3) ∗ (𝑦2 − 𝑦1) ∗ 𝑦3] (−𝑑)� (2) figure 8. the vanishing point (𝑥, 𝑦) is converted to road angle referred to the center of the image l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 121 robot will turn left or turn right depending on the heading of the road. the sign from the road angle (minus or plus) indicates which direction the robot has to go. if the road angle has minus value (from 0 to -90 degrees), it means the road is now heading to the left and the robot has to go to the left. vice versa, if the road angle has positive value (from 0 to 90 degrees), it means the road is now heading to the right and the robot has to go to the right. the obstacle detection has the highest priority to command the motors. if there is an obstacle detected in the left region, the robot will turn right at high speed. vice versa, if there is an obstacle detected in the right region, the robot will turn left at high speed. for high-speed turning (left or right), the pwm value is already set manually. after the obstacle is avoided, the robot will go back following the heading of the road. iii. results and discussion figure 10 describes the roads that are used to test the robot. the road beside soccer field at sgu campus has similar characteristics to the road in frederick d. fagg park [15]. they have red boundaries on the left and right sides of the road. the difference is the road beside soccer field at sgu campus has road marking in the middle of the road. these red boundaries and road marking will be detected as road lines by the camera. the road in front of ice has similar characteristics to the hellman why road. they are a little bit curved and have boundaries on the left and right sides of the road. on the hellman why road, the boundaries are colored red. on the other hand, the boundaries are formed from the road marking and colored white on the road in front of ice. the pedestrian road in front of glacido cluster has similar characteristics to the road in front of leavey library. they do not have any explicit lines. in the pedestrian road in front of glacido cluster, the road lines are formed from different contrast between the color of the grass (green) and the color of the pedestrian (gray). the vision system will try to detect the road lines that are formed from this different contrast. a. driving the robot in the selected environments without obstacle after the selected roads are tested to detect lines. the lines are used to detect the vanishing point. the detected vanishing points are converted to road angle to estimate the heading of the road. when the road angle changes, it means that the heading of the robot has to change also because the robot has to follow the heading of the road. as seen in figure 11, the lines detected on this road are formed from red boundaries on the left and the right sides of the road, from road markings located on the right side of the road. the road beside (a) (b) (c) figure 10. roads that are chosen to run the robot; (a) the road beside soccer field at sgu campus; (b) the road in front of ice; and (c) the pedestrian road in front of glacido cluster figure 11. detected vanishing point on environment 1 l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 122 soccer field at sgu campus side a is straight, therefore the road angle detected has to be around zero. when the robot starts to move, the detected road angles are plotted. the graph in figure 12 shows the detected road angle while the robot runs. the result comes up with a detected road angle from 0 to 10 degrees. the standard deviation of the detected road angle is 3.48 degrees. as seen in figure 13, the lines detected on the road in front of ice are formed from road markings on the left and right sides of the road. on the other hand, the lines detected on the pedestrian road in front of glacido cluster are formed from the difference of color, between the color of the grass and the color of the pedestrian road. the robot runs in environments 2 and 3 can be seen in figure 14. figure 13. detected vanishing point on environment 2 (top) and 3 (bottom) figure 14. the robot runs in environment 2 (top) and environment 3 (bottom) figure 12. graph of detected road angles in environment 1, the road beside soccer field at sgu campus l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 123 the detected road angles in the road in front of ice as shown in figure 15 have values from 0 to 5 degrees. the standard deviation of the detected road angle is 2.73 degrees the road is heading to the left therefore the robot is going to the left following the heading of the road. on the other hand, the detected road angles in the pedestrian road in front of glacido cluster as shown in figure 16 have values from 0 to more than 40 degrees. the standard deviation of the detected road angle is 53.1 degrees. the road is straight, therefore a value of 53.1 degrees does not represent the actual heading of the road. this is caused by the high texture of the grass which causes disturbance to the line detection. the output of edge detection which indicates the high texture of the grass is shown in figure 17. the inaccurate detection of road angle causes the robot to follow the wrong direction. therefore, during three testing times, the robot never reaches the end of the road and falls off from the road as shown in figure 18. figure 15. graph of detected road angles in environment 2 figure 16. graph of detected road angles in environment 3 figure 17. output of canny edge detection in environment 3 l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 124 b. obstacle detection and avoidance when the robot is following the heading of the road, the robot also avoids obstacle that was detected by the camera. the result of the obstacle detection using a simple blob detector and ultrasonic sensor can be seen in figure 19. as seen in figure 19, the obstacle will only be detected if the obstacle is located inside the detectable area (green box). if the obstacle is located in the left region, then the robot will turn right. and if the obstacle is located in the right region, then the robot will turn left. the vision system will only detect the position of the obstacle (𝑥, 𝑦) if it is located from distance between 130 cm to 200 cm from the robot. next, after the position of the obstacle is known. the robot calculates the distance to the obstacle by using the ultrasonic sensor. the information about the position and distance to the obstacle can be seen in figure 20. after the obstacle is avoided, next the robot will follow the vanishing point again to go back to the road. as seen in figure 21, the robot detects the obstacle in front of it by using a simple blob detector and measures the distance using an ultrasonic sensor. figure 18. the robot falls from the road because of an inaccurate road angle figure 19. the robot avoids obtacle while following the heading of the road figure 20. screenshot of a program when detecting the position and distance to the obstacle figure 21. the robot detects an obstacle and avoids it l. rusli et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 117-125 125 iv. conclusion the road detection algorithm has made a good output of vanishing points. the vanishing point detected represents the heading of the road referred to the center of the image. from testing in 3 different roads (road beside soccer field at sgu campus, road in front of ice, and pedestrian road in front of glacido cluster), the heading of the road is detected by the vision system with plus-minus of 0 to 10 degrees and standard deviation of fewer than 5 degrees. except for the road angles in the pedestrian road in front of glacido cluster which is inaccurate because of noises on detecting the road lines. the noises are caused by the high texture of the grass. for further recommendations, the implementation of imu can be used to estimate the horizon line. the horizon line is used for vanishing point voting which results in better vanishing point filtering. the implementation of the encoder can be used to estimate the absolute heading of the robot and a color detection algorithm can be applied to navigate the robot in an environment where the road lines are hard to be detected. acknowledgement the authors would like to thank swiss german university for supporting the project with internal research funds. declarations author contribution l. rusli is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] a. cherubini, f. spindler, and f. chaumette, “a new tentaclesbased technique for avoiding obstacles during visual navigation,” in proc. ieee international conference on robotics and automation (icra), 2012. [2] r. a. dasari, automatic driving system by recognizing road signs using digital image processing. proquest dissertations publishing, 10196473, pp. 1-28, 2016. [3] y. kondo, m. numada, h. koshimizu, and i. yoshida, “a study on fast and robust vanishing point detection system using fast m-estimation method and regional division for in-vehicle camera,” j. of electrical engineering, 6, 2018. [4] g. yang, y. wang, j. yang, and z. lu, "fast and robust vanishing point detection using contourlet texture detector for unstructured road," ieee access, vol. 7, pp. 139358-139367, 2019. [5] j. han, z. yang, g. hu, t. zhang, and j. song, “accurate and robust vanishing point detection method in unstructured road scenes,” j intell robot syst, 94, 143–158, 2019. [6] c. n. khac, y. choi, j. h. park, and h. jung, “a robust road vanishing point detection adapted to the real-world driving scenes,” sensors, 21, 2133, 2021. [7] z. yu and l. zhu, “roust vanishing point detection based on the combination of edge and optical flow,” in proc. of the 4th asia-pacific conference on intelligent robot systems (acirs), japan, pp. 184–188, 2019. [8] w. yang, b. fang, and y. y. tang, “fast and accurate vanishing point detection and its application in inverse perspective mapping of structured road,” ieee trans. syst. man cybern. syst., 48, 755–766, 2018. [9] y. li, w. ding, x. zhang, and z. ju, “road detection algorithm for autonomous navigation systems based on dark channel prior and vanishing point in complex road scenes,” robotics and autonomous systems, 85, 2016. [10] s. liu, y. zhou, and y. zhao, “vapid: a rapid vanishing point detector via learned optimizers,” in proc. of the ieee/cvf international conference on computer vision (iccv), pp. 12859-12868, 2021. [11] c. chang, j. zhao, and l. itti, "deepvp: deep learning for vanishing point detection on 1 million street view images," in proc. international conference on robotics and automation (icra), pp. 4496-4503, 2018. [12] h. kong, j. audibert, and j. ponce, “general road detection from a single image,” ieee transactions on image processing, vol. 19, no. 8, pp. 2211–2220. [13] o. miksik, “rapid vanishing point estimation for general road detection,” in proc. ieee international conference on robotics and automation (icra), 2012. [14] c. siagian, c. chang, r. voorhies, and l. itti, “beobot 2.0: cluster architecture for mobile robotics,” journal of field robotics, vol. 28, no. 2, pp. 278–302, march/april 2011. [15] c. siagian, c. chang, and l. itti, “mobile robot navigation system in outdoor pedestrian environment using vision-based road recognition,” in proc. international conference on robotics and automation, 564-571, 2013. [16] n. tokuda, t. funahashi, m. numada, and h. koshimizu, “the line detection by hough transform for vanishing point detection,” presented at view2012, is1-c6, dec. 2012. https://mev.lipi.go.id/ https://dx.doi.org/10.1109/icra.2012.6224584 https://dx.doi.org/10.1109/icra.2012.6224584 https://dx.doi.org/10.1109/icra.2012.6224584 https://dx.doi.org/10.1109/icra.2012.6224584 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.17265/2328-2223/2018.02.007 https://dx.doi.org/10.1109/access.2019.2944244 https://dx.doi.org/10.1109/access.2019.2944244 https://dx.doi.org/10.1109/access.2019.2944244 https://dx.doi.org/10.1109/access.2019.2944244 https://doi.org/10.1007/s10846-018-0814-8 https://doi.org/10.1007/s10846-018-0814-8 https://doi.org/10.1007/s10846-018-0814-8 https://doi.org/10.3390/s21062133 https://doi.org/10.3390/s21062133 https://doi.org/10.3390/s21062133 https://doi.org/10.1109/acirs.2019.8936016 https://doi.org/10.1109/acirs.2019.8936016 https://doi.org/10.1109/acirs.2019.8936016 https://doi.org/10.1109/acirs.2019.8936016 https://doi.org/10.1109/tsmc.2016.2616490 https://doi.org/10.1109/tsmc.2016.2616490 https://doi.org/10.1109/tsmc.2016.2616490 https://doi.org/10.1109/tsmc.2016.2616490 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://openaccess.thecvf.com/content/iccv2021/papers/liu_vapid_a_rapid_vanishing_point_detector_via_learned_optimizers_iccv_2021_paper.pdf https://openaccess.thecvf.com/content/iccv2021/papers/liu_vapid_a_rapid_vanishing_point_detector_via_learned_optimizers_iccv_2021_paper.pdf https://openaccess.thecvf.com/content/iccv2021/papers/liu_vapid_a_rapid_vanishing_point_detector_via_learned_optimizers_iccv_2021_paper.pdf https://openaccess.thecvf.com/content/iccv2021/papers/liu_vapid_a_rapid_vanishing_point_detector_via_learned_optimizers_iccv_2021_paper.pdf https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1016/j.robot.2016.08.003 https://doi.org/10.1109/tip.2010.2045715 https://doi.org/10.1109/tip.2010.2045715 https://doi.org/10.1109/tip.2010.2045715 https://doi.org/10.1109/icra.2012.6225206 https://doi.org/10.1109/icra.2012.6225206 https://doi.org/10.1109/icra.2012.6225206 https://doi.org/10.1002/rob.20379 https://doi.org/10.1002/rob.20379 https://doi.org/10.1002/rob.20379 https://doi.org/10.1109/icra.2013.6630630 https://doi.org/10.1109/icra.2013.6630630 https://doi.org/10.1109/icra.2013.6630630 https://doi.org/10.1109/icra.2013.6630630 https://doi.org/10.17265/2328-2223/2018.02.007 https://doi.org/10.17265/2328-2223/2018.02.007 https://doi.org/10.17265/2328-2223/2018.02.007 introduction ii. materials and methods iii. results and discussion a. driving the robot in the selected environments without obstacle b. obstacle detection and avoidance iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2018.v9.89-100 2088-6985 / 2087-3379 ©2018 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency rina ristiana a, b, *, arief syaichu rohman a, estiko rijanto c, agus purwadi a, egi hidayat a, carmadi machbub a a school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung, west java, indonesia b instrumentation development unit, indonesian institute of sciences komplek lipi jl. sangkuriang, bandung, west java, indonesia c research centre for electrical power and mechatronics, indonesian institute of sciences komplek lipi jl. sangkuriang, bandung, west java, indonesia received 23 october 2018; received in revised form 19 december 2018; accepted 20 december 2018 published online 30 december 2018 abstract this paper develops an optimal speed control using a linear quadratic integral (lqi) control standard with/without an observer in the system based on an integrated battery-electric vehicle (ibev) model. the ibev model includes the dynamics of the electric motor, longitudinal vehicle, inverter, and battery. the ibev model has one state variable of indirectly measured and unobservable, but the system is detectable. the objectives of this study were: (a) to create a speed control that gets the exact solution for a system with one indirect measurement and unobservable state variable; and (b) to create a speed control that has the potential to make a more efficient energy system. a full state feedback lqi controller without an observer is used as a benchmark. two output feedback lqi controllers are designed; including one controller uses an order-4 observer and the other uses an order-5 observer. the order-4 observer does not include the battery state of charge as an observer state whereas the order-5 observer is designed by making all the state variable as the observer state and using the battery state of charge as an additional system output. an electric passenger minibus for public transport with 1500 kg weight was used as the vehicle model. simulations were performed when the vehicle moves in a flat surface with the increased speed from stationary to 60 km/h and moves according to standard nedc driving profile. the simulation results showed that both the output feedback lqi controllers provided similar speed performance as compared to the full state feedback lqi controller. however, the output feedback lqi controller with the order-5 observer consumed less energy than with the order-4 observer, which is about 10% for nedc driving profile and 12% for a flat surface. it can be concluded that the lqi controller with order-5 observer gives better energy efficiency than the lqi controller with order-4 observer. ©2018 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: integrated battery-electric vehicle (ibev) model; speed control; electric vehicle; linear quadratic integral; observer system; energy efficient. i. introduction in the future, electric vehicles will be more widely used for mass transportation, implemented in special lines empowered by automatic systems such as driverless systems, assisted drive systems, self-driving systems and so on. this prospect has opened up new research areas for innovation in technology based on automation of specifically controlled systems. one of the limitations of electric vehicles is the limited amount of energy they can carry, which is mainly stored in its battery [1]. assuming that this limited capacity is because of existing battery technology, the problem should be solved using an energy-efficient strategy [2]. energy-efficient strategies for electric vehicles are one of several types of strategies that involve control design of the vehicle. the control design of an electric vehicle is implemented with vehicle/motor speed control [3] and torque control [4][5]. * corresponding author. tel: +62 813 7991 7553 e-mail address: rina005@lipi.go.id https://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2018.v9.89-100 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2018.v9.89-100&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 90 an important factor in designing such a control system is the electric vehicle model. in [3] and [4] an electric vehicle model with battery dynamics integrated into the system was presented. the use of an integrated model in electric vehicle control design (speed or torque) has been shown to have potential in achieving a more energy-efficient system. although the integrated model has one unobservable state variable, the system is still detectable. ideally, all state variables should be available for feedback in the system, but not all state variables are available for feedback. therefore, it needs to estimate unavailable state variables. estimation of unavailable state variables is called state observer. a state observer estimates the state variables based on the measurements of the output and control variables. the observers consist of: a full-order observer that is used to estimate all the state variables of the system that are considered available for direct measurement [6]. this paper describes how to design an optimal speed control using the lqi control standard with/without an observer in the system. the goals of this research were to create a control design: (a) that gets the exact solution for one state variable in the system which is unobservable and can only be measured indirectly, and (b) has the potential to be more energy efficient. the lqi control systems have been built in three cases, i.e. lqi control without observer (assumption that all variables are available for feedback), lqi control with an order-4 observer (ignoring one state variable of the system during designing the observer), and lqi control with an order5 observer (adding one state variable in the output of the system), which were compared to find the best response characteristics and to increase energy efficiency. ii. materials and methods a. integrated battery-electric vehicle (ibev) model the battery-electric vehicle (bev) model was built as an integrated model. this means that it is a model with battery dynamics involved in the system (figure 1). it includes an electric motor [7], an inverter [8], a longitudinal vehicle [9], and battery dynamics [10][11]. the integrated model is a linearized model derived from a nonlinear model. it is assumed that only the battery supplies the electric motor of the vehicle, hence the current of the battery are the same as the motor current. the gear trains have no backlash; they are rigid bodies. the shaft stiffness and each gear ratio are proportional to the radius of the gear [9]. the longitudinal dynamic equations were influenced by traction, acceleration, and total resistance forces as load (see figure 1). the total resistance forces included drag force, gradient force, rolling resistance force, and curvature resistance force [12]. according to [4], differential equations of the motor speed (1), the motor current (2), the first (3) and the second (4) capacitor voltage of the battery, and the charge extracted from the battery (5) respectively can be written as: 𝑑𝜔𝑚(𝑡) 𝑑𝑡 = − 𝑏𝑚 𝑛𝐽𝑡𝑜𝑡 𝜔𝑚(𝑡) + 𝑘𝑡 𝑛𝐽𝑡𝑜𝑡 𝑖𝑚(𝑡) − 𝑛2𝐾𝑑𝑟𝑤 3 2𝐽𝑡𝑜𝑡 𝜔𝑚 2(𝑡) + 𝑚𝑣𝑟𝑤𝑔 𝐽𝑡𝑜𝑡 (sin 𝜃 + 𝐶𝑅𝑥 cos 𝜃 + 𝑘𝑡𝑘 𝑅 ) (1) 𝑑𝑖𝑚(𝑡) 𝑑𝑡 = − 𝑘𝑒 𝐿𝑚 𝜔𝑚(𝑡) − 𝑅𝑚 𝐿𝑚 𝑖𝑚(𝑡) + 𝐾𝑐 𝐿𝑚 (−𝑅𝑑𝑖𝑚(𝑡) − 𝑉𝑐1(𝑡) − 𝑉𝑐2(𝑡) + 2𝑎1𝑆𝑂𝐶𝑛(𝑡) + 2𝑎1 + 2𝑎0)𝑢𝑐(𝑡) (2) 𝑑𝑉𝑐1(𝑡) 𝑑𝑡 = − 1 𝑅𝑡1𝐶𝑡1 𝑉𝑐1(𝑡) + 1 𝐶𝑡1 𝑖𝑏(𝑡) (3) 𝑑𝑉𝑐2(𝑡) 𝑑𝑡 = − 1 𝑅𝑡2𝐶𝑡2 𝑉𝑐2(𝑡) + 1 𝑖𝑏(𝑡) 𝐶𝑡2⁄ 𝑖𝑏(𝑡) (4) 𝑑𝑆𝑂𝐶𝑛(𝑡) 𝑑𝑡 = − 1 𝑄𝑛 𝑖𝑏(𝑡) (5) the battery voltage can be represented as: 𝑉𝑏(𝑡) = 𝑉𝑂𝐶(𝑡) − 𝑅𝑑𝑖𝑏(𝑡) − 𝑉𝑐1(𝑡) − 𝑉𝑐2(𝑡) (6) the open-circuit voltage (two batteries) is 𝑉𝑂𝐶(𝑡) = 2𝑎1𝑆𝑂𝐶(𝑡) + 2𝑎0 and the state of charge is 𝑆𝑂𝐶(𝑡) = (𝑆𝑂𝐶0(𝑡) + 𝑆𝑂𝐶𝑛(𝑡)) with𝑆𝑂𝐶0(𝑡) = 𝑄0 𝑄𝑛⁄ = 1, where 𝑅𝑑 , 𝑖𝑏 , 𝑅𝑡1 , 𝐶𝑡1 , 𝑅𝑡2 , 𝐶𝑡2 , 𝑎1 , 𝑎0 , 𝑄0 and 𝑄𝑛 are suitable constants [4][11]. the state variables are defined as 𝑥1(𝑡) = 𝜔𝑚(𝑡), 𝑥2(𝑡) = 𝑖𝑚(𝑡) , 𝑥3(𝑡) = 𝑉𝑐1(𝑡) , 𝑥4(𝑡) = 𝑉𝑐2(𝑡) and 𝑥5(𝑡) = 𝑆𝑂𝐶𝑛(𝑡) and the output variable as 𝑦(𝑡) = 𝜔𝑚(𝑡) = 𝑥1(𝑡). from equation (1) to (5), the state equation may be described as: �̇�𝑣(𝑡) = 𝑓(𝑥𝑣(𝑡)) + 𝑔(𝑥𝑣(𝑡))𝑢𝑐(𝑡) + 𝐻𝑑𝐿 𝑦𝑣(𝑡) = 𝐶𝑣𝑥𝑣(𝑡) (7) its matrices are given by: figure 1. integrated battery-electric vehicle (ibev) model [4] r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 91 𝑓(𝑥𝑣(𝑡)) = [ 𝑎11 + 𝑎𝑁𝐿 𝑎12 0 0 0 𝑎21 𝑎22 0 0 0 0 𝑎32 𝑎33 0 0 0 𝑎42 0 𝑎44 0 0 𝑎52 0 0 0] , 𝑔(𝑥𝑣(𝑡)) = [0 𝑔2 0 0 0] 𝑇, 𝐻 = [1 0 0 0 0]𝑇, 𝐶𝑣 = [1 0 0 0 0], where: 𝑎11 = − 𝑏𝑚 𝑛𝐽𝑡𝑜𝑡⁄ , 𝑎𝑁𝐿 = 𝑛 2𝐾𝑑𝑟𝑤 3𝑥1 2(𝑡) 2⁄ , 𝑎12 = 𝑘𝑡 𝑛𝐽𝑡𝑜𝑡⁄ , 𝑎21 = − 𝑘𝑒 𝐿𝑚⁄ , 𝑎22 = − 𝑅𝑚 𝐿𝑚⁄ , 𝑎32 = 1 𝐶𝑡1⁄ , 𝑎33 = 1 𝑅𝑡1𝐶𝑡1⁄ , 𝑎42 = 1 𝐶𝑡2⁄ , 𝑎44 = 1 𝑅𝑡2𝐶𝑡2⁄ , 𝑎52 = 1 𝑄𝑛⁄ , 𝐽𝑡𝑜𝑡 = (𝑚𝑣𝑟𝑤𝑛 + 𝐽𝑒𝑞)𝑟𝑤, 𝐽𝑒𝑞 = 𝐽𝑚 + (𝐽𝑡 𝑛𝑔 2⁄ ) + (𝐽𝑤 𝑛𝑔 2𝑛𝑡 2⁄ ), and 𝑔2 = −(𝑅𝑑𝑥2(𝑡) + 𝑥3(𝑡) + 𝑥4(t) − 2𝑎1𝑥5(𝑡) − 2(𝑎0 + 𝑎1))𝐾𝑐/𝐿𝑚. with 𝐾𝑑 = 𝜌𝐶𝑑𝐴𝑓 ; 𝑚𝑣 , 𝑟𝑤 , 𝜌, 𝐶𝑑 , 𝐴𝑓 , 𝐶𝑅𝑥 , 𝑔 , 𝜃 , 𝑘𝑡𝑘 , 𝑅, 𝑅𝑑 , 𝑖𝑏 , 𝑅𝑡1 , 𝐶𝑡1, 𝑅𝑡2 , 𝐶𝑡2, 𝑎1 , 𝑎0 , 𝑄0 , 𝑄𝑛 , 𝐿𝑚 , 𝑅𝑚, ke, , n=1/nggntt; g and t are suitable constants [4]. b. control system design the speed control system was designed using the linear control integral (lqi) method. the lqi computes an optimal state feedback control law for the tracking loop with the assumption that all state variables are available for feedback in the system. in this paper, three lqi controllers are designed, i.e. a state feedback lqi controller and two output feedback lqi controllers with observer systems such as order-4 observer and order-5 observer. the state feedback lqi controller is used as a benchmark for comparison study. luenberger observer is used in each output feedback lqi controller [13]. the first purpose of the lqi controller design is that the control design can answer in a proper way if there is a state variable in a system that is indirectly measurable and unobservable. the second purpose is to get one control design that has the potential to be more energy efficient. 1) lqi control the lqi control used is as shown in figure 2. based on (7), by ignoring 𝑑𝐿, a linearized plant can be derived as follows: �̇�𝑣(𝑡) = 𝐴𝑣𝑥𝑣(𝑡) + 𝐵𝑣𝑢𝑐(𝑡) 𝑦𝑣(𝑡) = 𝐶𝑣𝑥𝑣(𝑡) (8) the set point tracking is given by: �̇�𝑖(𝑡) = 𝑟(𝑡) − 𝐶𝑣𝑥𝑣(𝑡) (9) the full state feedback control is: 𝑢𝑐(𝑡) = −𝑘𝑣𝑥𝑣(𝑡) − 𝑘𝑖𝑥𝑖(𝑡) = −𝐾𝑧𝑥𝑧(𝑡) (10) the augmented state equation is obtained from [13] is: �̇�𝑧(𝑡) = 𝐴𝑧𝑥𝑧(𝑡) + 𝐵𝑧𝑢𝑐(𝑡) + 𝐺𝑧𝑟(𝑡) (11) where 𝐴𝑧 = [ 𝐴𝑣 0 −𝐶𝑣 0 ], 𝐵𝑧 = [ 𝐵𝑣 0 ], 𝐺𝑧 = [ 0 1 ], and 𝑥𝑧(𝑡) = [𝑥𝑣(𝑡) 𝑥𝑖(𝑡)] 𝑇. to stabilize the system of (11), a state feedback controller can be designed using 𝐾𝑧 = −𝑅 −1𝐵𝑧 𝑇𝑃, by assuming r > 0 and q ≥ 0, p is the solution of the following algebraic ricatti equation: 𝑄 + 𝐴𝑧 𝑇𝑃 + 𝑃𝐴𝑧 − 𝑃𝐵𝑧𝑅 −1𝐵𝑧 𝑇𝑃 = 0 (12) such a feedback controller minimizes the following performance index: 𝐽 = ∫ (𝑥𝑧(𝑡) 𝑇𝑄𝑥𝑧(𝑡) + 𝑢𝑐(𝑡) 𝑇𝑅𝑢𝑐(𝑡)) ∞ 0 𝑑𝑡 (13) the closed-loop system using lqi control with reference input is described by the augmented state equation that is obtained from: [ �̇�𝑣 �̇�𝑖 ] = [ 𝐴𝑣 − 𝐵𝑣𝐾𝑧 0 −𝐶𝑣 0 ] [ 𝑥𝑣 𝑥𝑖 ] (14) 2) lqi control with order-4 observer the lqi control with an order-4 observer is designed with the assumption that it has one state variable which can be directly measured (𝑥1(𝑡)) and three state variables, (𝑥2(𝑡), 𝑥3(𝑡) and 𝑥4(𝑡)), are not figure 2. the lqi control design [13] r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 92 directly measurable. figure 3 shows the lqi control system with an order-4 observer. in (7) the state variable 𝑥5(𝑡) is dependent on the state variable 𝑥2(𝑡). therefore, the state variable 𝑥5(𝑡) is ignored during observer design. equation (7) can be expressed as follows. �̇�𝑎(𝑡) = 𝐴𝑎𝑥𝑎(𝑡) + 𝐹𝑎𝑥5(𝑡) + 𝐵𝑎𝑢𝑐(𝑡) 𝑦𝑎(𝑡) = 𝐶𝑎𝑥𝑎(𝑡) (15) where 𝑥𝑎(𝑡) = [𝑥1(𝑡) 𝑥2(𝑡) 𝑥3(𝑡) 𝑥4(𝑡)] 𝑇, 𝐴𝑎 = [ 𝑎11 𝑎12 0 0 𝑎21 𝑎22 𝑎23 𝑎24 0 𝑎32 𝑎33 0 0 𝑎42 0 𝑎44 ] , 𝐹𝑎 = [ 0 𝑎25 0 0 ] , 𝐵𝑎 = [0 𝑏2 0 0] 𝑇, and 𝐶𝑎 = [𝑐1 0 0 0]. the state space equation for state variable 𝑥5(𝑡) is given by (16). �̇�5(𝑡) = 𝐴5𝑎𝑥𝑎(𝑡) + 𝐴5𝑏𝑥5(𝑡) + 𝑏5𝑢𝑐(𝑡) (16) where: 𝐴5𝑎 = [0 𝑎52 0 0], 𝐴5𝑏 = [0], and 𝑏5 = 0. state space equation of the order-4 observer is given by (17). �̇̃�𝑎(𝑡) = (𝐴𝑎 − 𝐿𝑎𝐶𝑎)�̃�𝑎(𝑡) + 𝐹𝑎𝑥5(𝑡) + 𝐵𝑎𝑢𝑐(𝑡) + 𝐿𝑎𝑦𝑎(𝑡) (17) state estimation error is given by (18). 𝑒𝑎(𝑡) = 𝑥𝑎(𝑡) − �̂�𝑎(𝑡) (18) therefore, the following equation holds. �̇�𝑎(𝑡) = �̇�𝑎(𝑡) − �̇̂�𝑎(𝑡) (19) by substituting (16) and (17) into (19), the following equation is obtained. �̇�𝑎(𝑡) = (𝐴𝑎 − 𝐿𝑎𝐶𝑎)𝑒𝑎(𝑡) (20) the state feedback control based on the observed state �̂�𝑎(𝑡) is: 𝑢𝑐(𝑡) = −𝑘𝑎�̂�𝑎(𝑡) − 𝑘𝑏𝑥5 − 𝑘𝑖𝑥𝑖(𝑡) (21) by substituting (20) into (16), the following equation is obtained. �̇�𝑎 = (𝐴𝑎 − 𝐵𝑎𝑘𝑎)𝑥𝑎 + (𝐹𝑎 − 𝐵𝑎𝑘𝑏)𝑥5 + 𝐵𝑎𝑘𝑎𝑒𝑎(𝑡) − 𝐵𝑎𝑘𝑖𝑥𝑖(𝑡) (22) from (9), (20), and (22), the system using the lqi control with the order-4 observer and using the assumption that the system has a reference input, can be described by the following augmented state equation. [ �̇�𝑎 �̇�𝑎 �̇�𝑖 ] = [ 𝐴𝑎 − 𝐵𝑎𝑘𝑎 𝐵𝑎𝑘𝑎 𝐵𝑎𝑘𝑖 0 𝐴𝑎 − 𝐿𝑎𝐶𝑎 0 −𝐶𝑎 0 0 ] [ 𝑥𝑎 𝑒𝑎 𝑥𝑖 ] + [ 𝐹𝑎 − 𝐵𝑎𝑘𝑏 0 0 ] 𝑥5 (23) where �̂�𝑎(𝑡) is the observer state variable, 𝐶1�̂�𝑎(𝑡) is estimated output, 𝑦𝑎(𝑡) is the system output, 𝑢𝑐(𝑡) is control variable, and 𝐿𝑎 is the luenberger observer gain matrix. figure 3. lqi control with order-4 observer r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 93 3) lqi control with order-5 observer the lqi control with an order-5 observer is designed with the assumption that it has one state variable which can be directly measured (𝑥1(𝑡)), three state variables, ( 𝑥2(𝑡) , 𝑥3(𝑡) and 𝑥4(𝑡) ), are not directly measurable, and one state variable 𝑥5(𝑡) is unobservable. figure 4 shows the lqi control system with an order-5 observer. in (7) the state variable 𝑥5(𝑡) is an integral of state variable 𝑥2(𝑡). therefore, in order to make the system be observable, 𝑥5(𝑡)is used as an additional output. equation (7) can be expressed as follows. �̇�𝑣(𝑡) = 𝐴𝑣𝑥𝑣(𝑡) + 𝐵𝑣𝑢𝑐(𝑡) 𝑦𝑏(𝑡) = 𝐶𝑏𝑥𝑣(𝑡) (24) where: 𝑥𝑣(𝑡) = [𝑥1 𝑥2 𝑥3 𝑥4 𝑥5] 𝑇, 𝑦𝑏(𝑡) = [𝑦𝑣 𝑦𝑤] 𝑇, 𝑥𝑏(𝑡) = [𝑥𝑣 𝑥5] 𝑇, 𝐴𝑣 = [ 𝑎11 𝑎12 0 0 0 𝑎21 𝑎22 𝑎23 𝑎24 𝑎25 0 𝑎32 𝑎33 0 0 0 𝑎42 0 𝑎44 0 0 𝑎52 0 0 0 ] , 𝐵𝑣 = [ 0 𝑏2 0 0 0 ] , 𝐶𝑏 = [𝐶𝑣 𝐶𝑤] 𝑇, 𝐶𝑣 = [𝑐1 0 0 0 0], and 𝐶𝑤 = [0 0 0 0 1]. state space equation of the order-5 observer is given by: �̇̃�𝑣(𝑡) = (𝐴𝑣 − 𝐿𝑣(𝐶𝑣 + 𝐶𝑤))�̃�𝑣(𝑡) + 𝐵𝑣𝑢𝑐(𝑡) + 𝐿𝑣(𝑦𝑣(𝑡) + 𝑦𝑤(𝑡)) (25) state estimation error is given by (26). 𝑒𝑣(𝑡) = 𝑥𝑣(𝑡) − �̂�𝑣(𝑡) (26) thus, the following equation holds. �̇�𝑣(𝑡) = �̇�𝑣(𝑡) − �̇̂�𝑣(𝑡) (27) by substituting (24) and (25) into (27), the following equation is obtained. �̇�𝑣(𝑡) = (𝐴𝑣 − 𝐿𝑣(𝐶𝑣 + 𝐶𝑤))𝑒𝑣(𝑡) (28) the state feedback control based on the observed state �̃�𝑣(𝑡) is: 𝑢𝑐(𝑡) = −𝑘𝑤�̃�𝑣(𝑡) − 𝑘𝑖𝑥𝑖(𝑡) (29) by substituting (29) into (24), the following equation is obtained. �̇�𝑣(𝑡) = (𝐴𝑣 − 𝐵𝑣𝑘𝑤)𝑥𝑣(𝑡) − 𝐵𝑣𝑘𝑤𝑒𝑣(𝑡) − 𝐵𝑣𝑘𝑖𝑥𝑖(𝑡) (30) from (9), (28), and (30), the system using the lqi control with the order-5 observer, and using the assumption that the system has a reference input, can be described by the following augmented state equation. [ �̇�𝑣 �̇�𝑣 �̇�𝑖 ] = [ 𝐴𝑣 − 𝐵𝑣𝑘𝑤 𝐵𝑣𝑘𝑤 𝐵𝑣𝑘𝑖 0 𝐴𝑣 − 𝐿𝑣(𝐶𝑣 + 𝐶𝑤) 0 −(𝐶𝑣 + 𝐶𝑤) 0 0 ] [ 𝑥𝑣 𝑒𝑣 𝑥𝑖 ] (31) where �̂�𝑣(𝑡) is the observer state variable, 𝐶𝑏�̂�𝑣(𝑡) is estimated output, 𝑦𝑏(𝑡) is the system output, 𝑢𝑐(𝑡) is control variable, and 𝐿𝑣 is the luenberger observer gain matrix. figure 4. lqi control with order-5 observer r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 94 iii. results and discussions a. model parameter molina the model parameters were taken from an experimental electric vehicle called molina itb type3 where the specifications can be seen in table 1. this vehicle was designed as a passenger minibus for public transport with 1500 kg weight and a wheel diameter of 58 cm. the used electric motor is a brushless dc (bldc) electric motor with an input voltage of 48 v, 10 kw of power, 3500 rpm of motor speed rate, and 120 a of motor current. meanwhile, the used power supply consisted of two 24 v lithium-ion batteries installed in series. each battery had a normal capacity of 100 ah. b. linearized integrated model for 24 v input voltage, a linearized integrated model was obtained at operating point xt = [m im vc1 vc2 socn] t = [1721 147.4 0.15 0.15 99.96]t. by ignoring 𝑑𝐿 in (7), the linearized integrated model (8) is in the following form: 𝐴 = [ −0.402 1603.77 0 0 0 −0.019 −3.941 −0.003 −0.003 −0.0002 0 294.118 −0.291 0 0 0 294.118 0 −0.291 0 0 294.118 0 0 0 ] , 𝐵 = [0 0.9871 0 0 0]𝑇, 𝐶 = [1.5305 0 0 0 0], and 𝐷 = [0]. from these matrices, the poles of the open-loop system are given by -2.1710+5.3327i, -2.1710-5.3327i, -0.0001, -0.2912, -0.2907. the poles of the open-loop system can be placed at any desired location, which means that the system of the plant is stable. the system of the open-loop system is fully controllable (av, bv ) but it is not fully observable (av, cv ), where the system has an observability rank of four. it means that the system has one state variable that is not observable, i.e. socn, but the system is detectable. c. cases of control design the various cases of the lqi control design were as follows: 1) case 1: lqi control the lqi control system is based on (9), the augmented state equation is given by (11), the performance index is using (13), the gain full state feedback is given by kv = [0.0234 5.6992 0.0008 0.0008 0.0015], and the gain integral is expressed in ki = [-0.0316]. the weighting matrices of the lqi are chosen based on trial and error approach. in order to obtain the optimum state feedback control gains, the weighting matrices were selected as follows: q = diag[0.1], and r = 100. a gain of state feedback that is defined by the eigenvalues of the system is necessarily needed to solve the problem. the eigenvalues of the closed-loop system in (14) are given as −4.884 + 7.007𝑖 , −4.884 − 7.007𝑖 , 0.224 + 0.104𝑖 , −0.224 − 0.104𝑖 , −0.044, and 0.291. table 1. parameter of molina itb type-3 specifications symbol value units motor bldc resistance rm 12.4 m inductance lm 34 uh torque constant kt 0.1082 nm/a inertia jm 48×10-6 kgm2 stiffness bm 79×10-4 nms/rad bmf constant ke 0.0128 vs/rad lithium-ion battery inner resistance 2 m terminal resistance, rt 1.72 m terminal capacitance, ct 2000 f n-capacity, qn 100 ah vehicle mass, mv 1500 kg wheel radius, rw 0.29 m wheel inertia, jw 12×10-6 kgm2 transmission inertia, jt 53×10-6 kgm2 air density,  1.25 kg/m 3 drag coefficient, cd 0.417 ns2/kgm frontal area, af 1.581 m2 rolling coefficient, crx 0.015 gravity coefficient, g 9.8 m/s2 r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 95 2) case 2: lqi control with order-4 observer to provide a solution for case 2, the partition state variables can be obtained using (15). the matrices are given as: 𝐴𝑎 = [ −0.402 1603.77 0 0 −0.019 −3.941 −0.003 −0.003 0 294.118 −0.291 0 0 294.118 0 −0.291 ], 𝐹𝑎 = [ 0 −0.0002 0 0 ] , 𝐵𝑎 = [ 0 0.987 0 0 ], 𝐶𝑎 = [1.531 0 0 0] 𝑇, 𝑘𝑎 = [0.023 5.699 0.0008 0.0008] , 𝑘5 = [−0.0316], 𝑘𝑖 = [−0.0316], and 𝐿𝑎 = [−0.4180 −0.0126 −0.330 −0.330] 𝑇. based on (23), the eigenvalues of the closed-loop system are given as -1.804+9.754i, -1.804-9.754i, -0.782, -0.289, -0.291, -2.168+5.391, -2.168-5.391, -0.297, and -0.291. 3) case 3: lqi control with order-5 observer to provide a solution for case 3, the partition state variables can be obtained using (24). the matrices are given by as: 𝐴𝑣 = [ −0.402 1603.77 0 0 0 −0.019 −3.941 −0.003 −0.003 −0.002 0 294.118 −0.291 0 0 0 294.118 0 −0.291 0 0 294.118 0 0 0 ] , 𝐵𝑣 = [0 0.9871 0 0 0] 𝑇, 𝐶𝑣 = [1.5305 0 0 0 0], 𝐶𝑤 = [0 0 0 0 1], 𝐾𝑤 = [0.0234 5.699 0.0008 0.0008 0.0015], 𝐾𝑖 = [−0.0423], and 𝐿𝑤 = [−0.008 −0.003 −0.007 −0.007 −0.003] 𝑇. based on (36), the poles or eigenvalues of the closed-loop system are given as -4.944+6.941i, -4.9446.941i, -0.0393+0.042i, -0.0.393-0.042i, -0.292, -2.164+5.265i, -2.164-5.265i, -0.002, -0.292, -0.291 and -0.291. all the eigenvalues of the closed-loop system and the observers must be negative. theoretically, these eigenvalues can be arbitrarily moved to minus infinity to achieve extremely fast convergence. the problem of selecting good eigenvalues is not easily solved. however, the observer may be slightly faster than the rest of the closed-loop system. generally, the formula is defined with 2 to 6 times larger poles for the observer than for the closed-loop systems’ poles. this can increase the noise on the observer side. in this case, the poles were set 5 times larger for the observer than for the closed-loop system. this means that the observer may be slightly faster than the closed-loop system and the observation error decays shortly to zero. initial condition values influence the state variables values forward through time. in other words, the state variables are a function of time and the initial condition values. the initial state variables values were selected as x(0) = [1 0 0 0 0]t. based on figure 5, in which the response to state variables versus time is shown, all state variables were defined. the state variables were: 𝑥1 = 𝜔𝑚, 𝑥2 = 𝑖𝑚, 𝑥3 = 𝑉𝑐1, 𝑥4 = 𝑉𝑐2, 𝑥5 = 𝑆𝑂𝐶𝑛 , and 𝑥𝑖 is the integral state. for all cases of the control design, it can be seen that the motor speed response (𝑥1) and the motor current response (𝑥2) were the same, whereas 𝑥3, 𝑥4, 𝑥5 and 𝑥𝑖 had a different response. it can be seen that 𝑥3 and 𝑥4 had the same response in case 1 (red line) and case 3 (black line), and reached steady state after 3 seconds, so that case 2 (green line) reached steady state after 4 seconds. also, 𝑥𝑖 was the same in case 1 and case 2, and reached steady state after 6 seconds. this was also the case in case 3, reaching a steady state after 1 seconds, which means faster than case 1 and case 2 by around 5 seconds. however, for 𝑥5 , case 2 had undershoot, while it reached steady state in the same time as case 2, i.e., after 6 seconds. case 3 had the best response, reaching a steady state after 2.6 seconds. this means that case 3 had unexploited battery energy. to obtain the response of the observer error vector to the following initial observer error e(0) = [1 0 0 0]t. the response to state estimate versus time with the initial observer error is shown in figure 6. the error was happened just for case 2 and case 3, while there is no error for case 1 because case 1 is designed without any observer. the state estimate in case 2 (red line) was 𝑒1 = �̃�𝑚, 𝑒2 = 𝑖̃𝑚, 𝑒3 = �̃�𝑐1, and 𝑒4 = �̃�𝑐2. in case 3 (blue line) it was 𝑒1 = �̃�𝑚 , 𝑒2 = 𝑖̃𝑚 , 𝑒3 = �̃�𝑐1 , and 𝑒4 = �̃�𝑐2 and 𝑒5 = 𝑆𝑂�̃�𝑛 . the response of case 3 is the fastest, which means that the observer has the same structure as the system, with a feedback driving term where the observation error decays shortly to zero. this means that case 3 had the best observer error response. d. energy consumption the purpose of this simulation was to see how the use of a bev model combined with the observer in the speed control design influences the energy consumption of the electric vehicle. an electric vehicle was simulated using a small-scale simulator, and the energy usage for a certain driving profile was presented in [14]. in this part of work, the energy consumption can be observed in two ways. first, the vehicle moves on a flat surface with a constant vehicle speed of 60 km/h in the r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 96 simulation, and second, a simulation was performed according to the standard nedc (a new european driving cycle) driving profile. the nedc is a test procedure as long as the vehicle moves at a speed profile. the speed profile has a major impact on the resulting energy consumption [15]. the formulation of the various performance index to observe the energy consumption was based on the following characteristics: • control energy 𝐸1 = ∫ 𝑉𝑚(𝑡) 2∞ 0 𝑑𝑡 or 𝐽1 = ∫ 𝑢𝑐 2∞ 0 𝑑𝑡 • mechanical energy 𝐸2 = ∫ 𝑇𝑚(𝑡)𝜔𝑚(𝑡) ∞ 0 𝑑𝑡 or 𝐽2 = ∫ 𝑥2𝑥1 ∞ 0 𝑑𝑡 • motor energy input 𝐸3 = ∫ 𝑉𝑚(𝑡)𝐼𝑚(𝑡) ∞ 0 𝑑𝑡 or 𝐽3 = ∫ 𝑢𝑐𝑥2 ∞ 0 𝑑𝑡 figure 5. initial condition response (state variable versus time) r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 97 1) constant vehicle speed in this simulation, the vehicle was moving on a flat surface with a constant speed at 60 km/h for 15 seconds duration. in figure 7, it was shown that the motor speed reached 3000 rpm, and control signal about 41 v with the same response for all cases. however, it was also shown that all three cases had different time settling. in case 1, it was a faster settling time, while in case 2, it was a slower settling time. the response of the motor current showed the same transient response. this means that if the motor current has different values for reaching 3000 rpm or 60 km/h, it has an effect on energy consumption. the energy consumption was presented by j1, j2, and j3. figure 6. the error of observer response (state observer versus time) table 2. energy consumption state feedback energy consumption (watt-hour) j1 j2 j3 constant vehicle speed at 60 km/h (during 15 seconds) case 1 0.798×103 2.205×10 3 2.796×103 case 2 0.701×103 1.944×103 2.465×103 case 3 0.626×103 1.732×103 2.196×103 nedc profile (during 1200 seconds) case 1 1.223×103 5.025×10 3 6.369×103 case 2 1.061×103 4.396×10 3 5.528×103 case 3 0.964×103 3.964×10 3 5.020×103 r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 98 in table 2, it was shown that the energy consumption in case 3 was 27.45% (j1), 27.27% (j2), and 27.34% (j3) better than in case 2. the energy consumption in case 3 also showed 12.04%, 12.21% and 12.24%, for j1, j2, and j3 respectively, which were better than in case 1. this result means that the energy consumption in case 3 was the most efficient out of these three cases. 2) nedc driving profile a simulation was performed on the moving vehicle according to the nedc driving profile for 1200 seconds. the simulation result can be seen in table 2 where the energy consumption for the vehicle using nedc profile in case 3 was 21.17% (j1), 21.12% (j2) and 21.18% (j3) better than in case 2. the energy consumption in case 3 also showed 10.04%, 10.09% (a) (b) (c) figure 7. response system when the vehicle moved; (a) motor speed response; (b) control signal response; (c) current response r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 99 and 10.12% better than in case 1 for j1, j2, and j3 respectively. this result means that the energy consumption in case 3 is the most efficient out of these three cases. iv. conclusion optimal speed control with observer applied to an integrated battery-electric vehicle (ibev) model was presented. an lqi control design was used for the feedback control design, and a luenberger observer was used to design the observer. in the design of the observer, it was assumed that there was one indirectly measurable and unobservable state variable in the system that was used to build the lqi control with order-5 observer. for comparison, an lqi control only and an lqi control with order-4 observer were also designed. all control design cases simulated a vehicle moving on a flat surface and moving according to the nedc driving profile. the lqi control with order-5 observer (case 3) provided the highest energy efficiency. moreover, the transient response in case 3 was slightly faster than in case 2. an optimal speed control design with observer was shown to have the potential to provide higher energy efficiency for integrated battery-electric vehicles. its application is currently under further research. acknowledgement the authors would like to acknowledge the support of lpnk scholarship given to the first author by the indonesian ministry of research, technology, and higher education. the valuable comments from the reviewers and also from the scholars of the school of electrical engineering and informatics, institut teknologi bandung, indonesia are also very much appreciated. references [1] a. g. boulanger, a. c. chu, s. maxx, and d. l. waltz, “vehicle electrification: status and issues,” proceeding of the ieee, vol. 99, no. 6, pp. 1116–1138, jun. 2011. [2] q. wang and m. deluchi, “impacts of electric vehicles on primary energy consumption and petroleum displacement,” energy, vol. 17, no. 4, pp. 351–366, apr. 1992. [3] r. ristiana, a. s. rohman, a. purwadi, and c. machbub, “energy efficient torque control using integrated batteryelectric vehicle model,” in proceeding of 2017 7th ieee international conference on system engineering and technology (icset), 2017, pp. 223–228. [4] r. ristiana, a. s. rohman, a. purwadi, and c. machbub, “integrated battery-electric vehicle model and its optimal speed control application,” in proceeding of 2017 3rd international conference on control, automation and robotics (iccar), 2017, pp. 588–592. [5] r. ristiana, h. hindersah, a. s. rohman, c. machbub, a. purwadi, and e. rijanto, “torque control using integrated battery-electric vehicle model with flexible shaft,” in proceeding of 2017 4th international conference on electric vehicular technology (icevt), 2017, pp. 24–29. [6] j. o'reilly, observers of linear system, london: academic press, 1983. [7] r. w. erickson and d. maksimović, fundamentals of power electronics. boston, ma: springer us, 2001. [8] c.-l. xia, permanent magnet brushless dc motor drives and controls. singapore: john wiley & sons singapore pte. ltd., 2012. [9] t. d. gillespie, fundamentals of vehicle dynamics. warrendale, pa: sae international, 1992. [10] g. l. plett, "modelling, simulation and identification of battery dynamics," wiley, 2014. [11] m. oswal, j. paul, and r. zhao, “a comparative study of lithium ion batteries,” university of southern california, 2010. [12] r. d. martino, “modelling and simulation of the dynamic behavior of the automobile,” thesis of degree, faculty of engineering, universita degli studi at salerno, 2005. [13] u. kiencke and l. nielsen, automotive control systems. berlin, heidelberg: springer berlin heidelberg, 2005. [14] a. r. al tahtawi and a. s. rohman, “simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose,” journal of mechatronics, electrical power, and vehicular technology, vol. 7, no. 2, p. 77, dec. 2016. [15] e. c. j. r. centre, regulated emissions of a euro 5 passenger car measured over different driving cycles, institute for environment and sustainability, 2010. https://doi.org/10.1109/jproc.2011.2112750 https://doi.org/10.1109/jproc.2011.2112750 https://doi.org/10.1109/jproc.2011.2112750 https://doi.org/10.1016/0360-5442(92)90110-l https://doi.org/10.1016/0360-5442(92)90110-l https://doi.org/10.1016/0360-5442(92)90110-l https://doi.org/10.1109/icsengt.2017.8123450 https://doi.org/10.1109/icsengt.2017.8123450 https://doi.org/10.1109/icsengt.2017.8123450 https://doi.org/10.1109/icsengt.2017.8123450 https://doi.org/10.1109/icsengt.2017.8123450 https://doi.org/10.1109/iccar.2017.7942765 https://doi.org/10.1109/iccar.2017.7942765 https://doi.org/10.1109/iccar.2017.7942765 https://doi.org/10.1109/iccar.2017.7942765 https://doi.org/10.1109/iccar.2017.7942765 https://doi.org/10.1109/icevt.2017.8323528 https://doi.org/10.1109/icevt.2017.8323528 https://doi.org/10.1109/icevt.2017.8323528 https://doi.org/10.1109/icevt.2017.8323528 https://doi.org/10.1109/icevt.2017.8323528 https://www.elsevier.com/books/observers-for-linear-systems/oreilly/978-0-12-527780-8 https://www.elsevier.com/books/observers-for-linear-systems/oreilly/978-0-12-527780-8 https://doi.org/10.1007/b100747 https://doi.org/10.1007/b100747 https://doi.org/10.1002/9781118188347 https://doi.org/10.1002/9781118188347 https://doi.org/10.1002/9781118188347 https://doi.org/10.4271/r-114 https://doi.org/10.4271/r-114 http://mocha-java.uccs.edu/bms1/ http://mocha-java.uccs.edu/bms1/ http://www.ehcar.net/library/rapport/rapport204.pdf http://www.ehcar.net/library/rapport/rapport204.pdf http://www.ehcar.net/library/rapport/rapport204.pdf https://tel.archives-ouvertes.fr/tel-00736040/document https://tel.archives-ouvertes.fr/tel-00736040/document https://tel.archives-ouvertes.fr/tel-00736040/document https://doi.org/10.1007/b137654 https://doi.org/10.1007/b137654 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 http://www.unece.org/fileadmin/dam/trans/doc/2010/wp29grpe/wltp-dhc-04-03e.pdf http://www.unece.org/fileadmin/dam/trans/doc/2010/wp29grpe/wltp-dhc-04-03e.pdf http://www.unece.org/fileadmin/dam/trans/doc/2010/wp29grpe/wltp-dhc-04-03e.pdf r. ristiana et al. / journal of mechatronics, electrical power, and vehicular technology 9 (2018) 89–100 100 this page is intentionally left blank mev journal of mechatronics, electrical power, an d vehicular technology 9 (2018) 29-35 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.29-35 2088-6985 / 2087-3379 ©2019 research centre for electrical power an d mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. quasi-flat linear pm generator optimization using simulated annealing algorithm for wec in indonesia budi azhari a, *, francisco danang wijaya b a research centre for electrical power an d mechatronics, in donesian institute of sciences jl. cisitu no. 154d, bandung, 40135, in donesia b department of electrical engineering and information technology, engineering faculty, universitas gadjah mada jl. grafika 2, sleman, di yogyakarta, 55281 in donesia received 29 a ugust 2019; accepted 5 december 2019; published online 17 december 2019 abstract linear permanent magnet generator (lpmg) is an essential component in recent wave energy converter (wec) which exploits wave’s heave motion. it could be classified into tubular-type, flat-tricore type, and quasi-flat type. in previous researches, these three models have been studied and designed for pico-scale wec. design optimization has further been conducted for flat-tricore lpmg, by using simulated annealing (sa) algorithm. it modified some parameters to minimize the resulted copper loss. this paper aims to optimize a quasi-flat lpmg design by applying sa algorithm. the algorithm would readjust the initial lpmg parts dimension. then, the output of the optimized design would be analyzed and compared. the results showed that the optimization could reduce the copper loss by up to 73.64 % and increase the efficiency from 83.2 % to 95.57 %. for various load resistances, the optimized design also produces larger efficiency. however, the optimized design has a larger size and produces larger cogging force than the initial design. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: design optimization; copper loss; simulated annealing; quasi-flat lpmg. i. introduction as the ocean wave provides relatively huge energy, several energy conversion methods have been developed. considering the technique, one quite popular approach is by exploiting the heave motion of the ocean wave. several models are utilizing this way, including archimedes wave swing (aws), seabeavl wave energy converter (wec) and aqua buoy[1][2]. in recent wec methods, the use of linear permanent magnet generators (lpmg) as mechanical to electrical converter is the key factor, hence it's design should be made as reliable and optimum as possible. basically, the lpmg could be classified based on its stator core shape. the first one, tubular-type has tubular shape, higher maximum flux density, and is able to produce low detent force [3][4]. the second model, flat-type lpmg, forms prism shape. it could be further formed into different cross-section shape: quasi-flat with rectangular prism and flat-tricore with triangular prism. compared to the first type of tubular lpmg, the flat-type lpmg could generate slightly higher output voltage and specific power for equal loads [5]. furthermore, the previous investigation has found that the quasi-flat type produces slightly higher flux density as well as induced voltage than the flat-tricore lpmg [6]. the configurations of these types are shown in figure 1 and figure 2. according to the placement site, there are three options: offshore, shoreline, and nearshore. the offshore location provides the highest input power, thus the generated electrical energy of this placement model is also the highest. however, it is also exposed to greater risk from environment conditions, such as weather, water salinity, and possible natural disaster. these factors give challenges to its building and maintenance. the shoreline and nearshore wecs, on the other hand, experience different conditions. they might produce less output power, but cheaper and easier in maintenance [7]. * correspon ding author. tel: +62-85729408875 e-mail address: budi.azhari19@gmail.com, budi030@lipi.go.id https://dx.doi.org/10.14203/j.mev.2019.v10.29-35 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.29-35 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.29-35&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 30 as one of the countries with promising wave energy resources, indonesia could benefit from this source for electrical power generation. previous researches have designed tubular and flat lpmgs for wec in indonesia [8][9]. the designs were built based on the offshore condition in south java ocean, indonesia. further research was also conducted to optimize the design of flat-tricore lpmg. the optimization was aimed to minimize resulted copper losses, by modifying the dimension of the generator parts. for this purpose, simulated annealing (sa) algorithm had been used [10]. the results showed that the utilization of the algorithm could reduce the copper loss and increase the electrical efficiency of the lpmg [10]. in this paper, the copper loss optimization by using the simulated annealing algorithm would be applied to a quasi-flat lpmg. this lpmg would also be used as a component of a pico-scale wec in south java ocean. prior to the optimization, an initial unoptimized 1 kw quasi-flat lpmg design would be provided. after the optimization process, the output parameters of the optimized design would be analyzed and compared to the initial one. ii. materials and methods a. proposed quasi-flat lpmg for comparison purposes, an initial unoptimized design would be presented first. in this case, a quasiflat lpmg had been designed before, considering wave characteristics in south java ocean during certain periods [9]. the design has rectangular prismshaped surface, as shown in figure 3. the process and technique of designing this generator were based on [11]. the generator would be used for wec with a floating buoy, where the scheme is shown in figure 4. the quasi-flat lpmg was composed of two main parts: translator and stator. the stator core was made of us steel type 2 core. to reduce power loss from eddy current, the stator was composed of stacks of lamination, with each lamination width of about 0.6 mm. moreover, electrical output could be extracted from stator winding terminal, which used awg 11 wire. in translator, permanent magnets were placed in radial array. the magnets used ndfeb 35/n35, with residual flux density of 1.17 t and coercivity of 868,000 a/m. meanwhile, the translator core was made of ferromagnetic carpenter silicon iron 1066 c. the use of ferromagnetic material in the translator core was meant to maximize the magnetic flux flowing to the stator. the path of the flowing magnetic flux in the radial array is shown in figure 5. the dimension of the generator parts were being calculated considering the expected output and wave characteristics in its location. the wave characteristics were previously analyzed based on the monthly average wave height data on that location from 2000 to 2010. however, only the wave height in july and august which were considered because the wave height in these periods was maximum. according to the data, the average wave height used as the reference was 0.845 m, with wave period figure 1. flat-tricore type (left) and quasi-flat type (right) of lpmg figure 2. tubular type lpmg figure 3. upper view of proposed quasi-flat lpmg figure 4. placement scheme of lpmg in wave energy power plant: (a) floating buoy, (b) connector, (c) tran slator, (d) stator, (e) supporting part [10] b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 31 was 5.61 s. the potential power which could be provided was then about 34.57 kw/mcl. given these conditions, the size of the quasi-flat lpmg parts was then specified. the length of the stator (ls, in meter) could be calculated using the equation below, 𝐿𝑠 = p√2 msbmjwsv . (1) parameter p is expected output power (w), ms is number of armature, bm is air-gap flux density under magnets (t), j is current density (a/m), ws is stator width (m), and v is rated translation speed (m/s). the ls then determines the dimension of pole pitch (τp, in meter) and tooth pitch (τt, in meter). however, they are also determined by number of slot (s), pole (p), and phase (m). 𝜏𝑝 = ls p , (2) 𝜏𝑡 = τp mq . (3) q is slot/pole/phase. the size of the tooth pitch (τt) is then partitioned for slot width (bs) and tooth width (bt) –both are in meter by a certain proportion, 𝜏𝑡 = bt + bs. (4) meanwhile, the length of the permanent magnet (τm, in meter) is affected by magnetic flux comparison of cm, 𝜏𝑚 = cmτp, (5) 𝐶𝑚 = bg bm . (6) bg is average flux density in air gap (t). the pole pitch (p, in meter) then determines the thickness of stator yoke (ys) and translator yoke (yr) –both in meter, as follow, 𝑌𝑠 = τpbg 2bys , (7) 𝑌𝑟 = τpbg 2byr . (8) bys and byr are the permissible flux density in stator core and rotor core (t) respectively. the equivalent air gap width (geq, in meter) is based on initial air gap (g, in meter). it could be calculated by using the equation below, 𝑔𝑒𝑞 = τt(5g+bs) τt(5g+bs)−bs 2 g. (9) the value geq and br (pm remanence, in tesla) then determine the thickness of the permanent magnet (hm, in meter), ℎ𝑚 = geq(brbg) μ0|hc|(br−bg) . (10) finally, the number of stator coil turn is decided based on the expected induced voltage (eph, in volt), 𝐸𝑝ℎ = msnphbmwsv √2 , (11) 𝑁𝑐 = nph pq . (12) nc and nph are winding turn/slot and winding turn/phase successively. for rw is typical wire resistance (ω/m) and lc is coil length (m), the phase resistance is, 𝑅𝑝ℎ = rwlcnph. (13) the output real power of the generator (pout, in watt) could be calculated based on the load resistance, 𝑃𝑜𝑢𝑡 = iph 2rl. (14) meanwhile, the copper power loss of the generator (ploss, in watt) is, 𝑃𝑙𝑜𝑠𝑠 = iph 2rph. (15) iph is phase current (a), rl and rph are the load winding resistance (ω) and phase winding resistance (ω) successively. the complete design and its parameters’ symbol is shown in figure 6. b. simulated annealing (sa) algorithm in an optimization process, there are basically several ways to solve a problem. one of them is by using stochastic approach. in this way, optimal solution is searched by trials and error in several iterations. furthermore, this approach could be divided into heuristic and metaheuristic. the latter approach includes tradeoff and randomization during trial and error process. the randomization is useful so that the search is for global optimal rather than local optimal, thus the result would be more accurate. many nature events inspire the building of metaheuristic optimization algorithms. among them, there is simulated annealing (sa), composed by kickpatrick et al. in 1983. this method uses a single agent or solution which goes along a search space in a piecewise style [12][13]. the algorithm has a similar concept with annealing process of solid material. it is a physical process where a solid material is heated up to its melting state. after that, the material would be chilled down slowly until reaching a certain low temperature, with sometimes crystallization occurs to the material. in optimization problem, probable solution is represented by the solid material’s state. meanwhile, the values of the objective function are represented by the energy of states. in this case, the optimal solution corresponds to the lowest energy state. figure 5. the flow of magnetic flux in radial permanent magnets array (red arrows show pms’ orientation) b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 32 in finding the optimum solution, the sa algorithm exploits iterations. in each iteration, current solution is randomly updated to a new solution. the algorithm would compare the updated solution in each iteration to the previous one. if a new solution is better according to the objective, it would replace the old one and would become the new solution for the next iterations. nevertheless, the probability of random uniform number that is generated from the iteration process might be smaller than predetermined function value. in this case, the new solutions would be treated as a better solution to replace the prior solution. this repeated process would run until the last iteration. this algorithm has had wide applications in power system. it helps to solve economic load dispatch problems in power generation by minimizing generation cost function, even penalty terms are included [14]. it could also guide to optimum distribution network reconfiguration with power loss considerations. the mechanism of this algorithm could avoid the search process being fell into local optimal, and thus the solution of this method is most likely the global optimal. on the other hand, this algorithm requires quite longer computation time than some other metaheuristic algorithms. in this research, the sa algorithm would be used to find the optimum dimension of the quasi-flat lpmg design which produce minimum copper loss, as stressed in the objective function below, 𝐹𝑜𝑏𝑗𝑒𝑐𝑡𝑖𝑣𝑒 = min⁡(𝑃𝑙𝑜𝑠𝑠) (16) to achieve this objective, the dimension of stator width (ws), slot height (hs), and slot width (bs) were modified. however, the dimension of the remaining lpmg parts would be affected and would be readjusted later based on those three. among the three variables, the first is affecting the induced voltage. meanwhile, the other two affect the coil length, which corresponds to its resistance. combination of these components would determine the resulted copper loss, and the algorithm is expected to adjust these variables in order to minimize the copper loss. after setting those variables, the resulted copper loss would be calculated. at the end of this process, the minimum copper loss would be obtained, and other parts’ dimensions were re-calculated based on the optimized parameters. finally, the output values of the resulted generator would be presented and compared. the optimization flowchart is presented in figure 7, while the optimization settings are shown in table 1. (a) (b) figure 6. design of the lpmg; (a) 3-dimen sion, (b) front view start i = 0 determine initial ws, bs, bh calc ulate initial p loss i ++ ploss(i)>ploss(i-1)? use ws(i), bs(i), bh(i) use ws(i-1), bs(i-1), bh(i-1) i = m ax _iter? calc ulate other lpmg parameters end yes yes no no figure 7. flow chart of the optimization using sa algorithm table 1. lpmg optimization setting using sa algorithm parameters symbol value initial temperature t0 324 (oc) reduction rate alpha 0.99 maximum iteration i 100 number of sub-iteration 20 variables stator width (m) ws 30<ws<100 (mm) slot width (m) bs 3<bs<20 (mm) slot height (m) hs 30<h s<300 (mm) constraint electromotive force (v) eph ≤ 150 (v) b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 33 iii. results and discussions a. resulted design of quasi-flat lpmg the resulted initial and optimized dimensions of the quasi-flat lpmg design are shown in table 2. it could be seen that, except the slot height and the air gap width, most of the optimized lpmg parts have larger dimension than the corresponding initial design parts. among the three independent variables, the dimension of the slot height in the optimized design is the only part that decreases. however, due to its huge reduction, the space volume which the stator coils could fill also reduces significantly. as shown in table 2, the number of turn then decreases by half. this condition at first leads to decrease of the induced voltage. to maintain the output after this winding turn reduction, the magnetic flux flowing to the winding was adjusted. in this case, the size of the permanent magnet should normally be increased. from the table, it could be seen that the length of the optimized permanent magnets increases, while the thickness is constant. it then results in an increase of the magnet's mass and volume. b. electrical and mechanical properties the output parameters of both designs are shown in table 3. from the table, it could be seen that the induced voltage is constant during the optimization. the reduction of the turn number is compensated by increase of the pm dimensions. on the other hand, the decrease in turn number also reduces the coil length, which directly proportional to the coil resistance. by reducing it, the coil resistance drops so does the copper loss. it is shown that the optimization could reduce up to 73.64 % of the copper loss. this decrease is caused by shortening of the stator coil length, which then reduces its resistance value. consequently, the electrical efficiency increases from 83.2 % to 95.6 %, considering equal input power. meanwhile, other parameters including the induced voltage and the line current are relatively constant. on the other hand, the optimization also increases the overall mass and volume of the lpmg, as shown in figure 8. according to the previous table 2, the weight of the generator increases after the optimization process. besides, the optimization also increases the resulted cogging force of the lpmg, due to stronger interaction between the larger permanent magnets and the ferromagnetic yoke. (a) e figure 8. detailed design of (a) initial design, and (b) optimized design of lpmg (all dimen sions are stated in cm) b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 34 this emerged effect could produce vibration, disturb the motion of the translator, and then resulted in some noises [15]. the comparison of the cogging force from both designs over a translation period is shown in figure 9. nevertheless, as opposed to a better electrical output, the optimized design suffers more mechanical loss compared to the initial one. the output characteristics of both designs in loaded condition were also analyzed. the efficiency of both designs for various load resistances is shown in figure 10. it could be seen that the optimized design produces larger efficiency for various load compared to the initial design. moreover, the efficiency has been increased as the resistance increased up to a certain values. at the certain load resistance value, the efficiency is getting stable even if the resistance increases. if those optimization results are compared with those from the flat-tricore type lpmg [10], the quasiflat type produces larger output power as well as efficiency for equal input power. however, the flatquasi type has larger size and weight. in fact, it is understandable that with fewer side number, the flattricore design is relatively slimmer and thinner, thus becomes lighter. in the next research, the electrical and mechanical properties of the generator are better be considered altogether during the optimization process. the weight and material cost of the generator should also be optimized or at least the possible increase should be considerably limited. (a) (b) figure 9. coggin g force of (a) initial design, (b) optimized design figure 10. output electrical efficiency of both initial and optimized design table 2. detailed dimen sions and parameters of initial and optimized design of the lpmg variab les and symb ols initial optimized stator width, ws 50 (mm) 100 (mm) stator surface, as 13,500 (mm2) 44,900 (mm2) stator length , ls 270 (mm) 450 (mm) pole-pitch,τ p 45 (mm) 75 (mm) tooth-pitch, τ t 15 (mm) 25 (mm) slot width, bs 12 (mm) 20 (mm) tooth width, bt 3 (mm) 5 (mm) carter coefficient, kc 3.36 4.98 equivalent air gap, geq 16.8 (mm) 14.9 (mm) pm thickness, hm 13 (mm) 13 (mm) pm length, τ m 40 (mm) 67.5 (mm) stator yoke thickness, ys 6 (mm) 10.5 (mm) translator yoke thickness, yr 9 (mm) 15.6 (mm) number of turns/slot, nc 276 turns 138 turns number of turn/phase, nph 1,656 turn s 828 turns space between pm, spm 5 (mm) 7.5 (mm) slot height, hs 160 (mm) 60.6 (mm) average coil length, lc 890 (mm) 590 (mm) pm mass, mpm 4.617 (kg) 15.570 (kg) translator mass, mtran s 1.878 (kg) 5.144 (kg) moving part mass, mmov 6.495 (kg) 20.714 (kg) stator mass, mstat 50.534 (kg) 74.169 (kg) total mass, mtot 57.029 (kg) 94.883 (kg) b. a zhari and f.d. wijaya et al. / journal of mechatronics, electrical power, and vehicular technology 10 (2019) 29–35 35 iv. conclusion design optimization of the quasi-flat lpmg has been conducted by using simulated annealing (sa) algorithm. the optimization was applied in previously designed lpmg, which was proposed for wave energy converter (wec) in south java ocean, indonesia. it was aimed to minimize the copper loss in stator winding by modifying stator width, slot width, and slot height. the results showed that the optimized design could reduce 73.64 % of power loss and increase electrical efficiency from 83.2 % to 95.6 %. the efficiency of the optimized design was also larger than the initial design for various load resistances. however, design optimization has increased the size of the generator, as well as the weight of the overall wec. acknowledgement authors gratefully acknowledge and appreciate to department of electrical engineering and information technology, universitas gadjah mada for their helpful support. some facilities for finishing the research as well as literatures were also provided by them. declarations author contribution b. azhari is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] s. k. kottayil, r. krishna, m. leijon, m. rahm, r. waters, and o. svensson, “analysis of linear wave power generator model with real sea experimental results,” iet renew. power gener., vol. 7, no. 5, pp. 574–581, sep. 2013. [2] m. i. marei, m. mokhtar, and a. a . el-sattar, “mppt strategy based on speed control for aws-based wave energy conversion system,” renew. energy, vol. 83, pp. 305–317, nov. 2015. [3] c. a . oprea, c. s. martis, f. n. jurca, d. fodorean, l. szabo, an d l. szabó, “permanent magnet linear generator for renewable energy application s: tubular vs. four-sided structures,” in 2011 international conference on clean electrical power (iccep), 2011, pp. 588–592. [4] l. huang, h. yu, m. hu, c. liu, and b. yuan, “research on a tubular primary permanent-magnet linear generator for wave energy con version s,” ieee tran s. magn ., vol. 49, no. 5, pp. 1917–1920, may 2013. [5] q. li, j. xiao, and z. huang, “flat-type permanent magnet linear alternator: a suitable device for a free piston linear alternator,” j. zhejiang univ. a, vol. 10, no. 3, pp. 345–352, mar. 2009. [6] aamir hussain memon , t. bin ibrahim, an d n. perumal, “portable and pico-scale linear generator for wave energy conversion,” in 2014 5th international conference on intelligent and advanced systems (icias), 2014, pp. 1–4. [7] n. delmonte, d. barater, f. giuliani, p. cova, and g. buticchi, “review of oscillating water column converters,” ieee trans. ind. appl., pp. 1–1, 2015. [8] b. a zhari, f. danang wijaya, w. prawinnetou, an d h. dewangga adhyaksa, “analytical design of sea wave energy power plant usin g tubular linear pm generator in southern coast of yogyakarta, indonesia,” in 2016 3rd international conference on information technology, computer, an d electrical engineering (icitacee), 2016, pp. 1–6. [9] b. azhari, w. prawinnetou, an d d. a. hutama, “design of a quasi-flat linear permanent magnet generator for pico-scale wave energy converter in south coast of yogyakarta, indonesia,” aip conference proceedings 1826(1): 2017, p. 20024. [10] f. d. wijaya, sarjiya, r. p. . muhammad, and d. p. kukuh, “design optimization of tri core pm linear generator using sa and fpa for wave energy conversion system in south coast of java island,” in 2016 2nd international conference on science and technology-computer (icst), 2016, pp. 118–123. [11] r. parthasarathy, “linear pm generator for wave energy conversion”, etd-041820. baton rouge: louisiana state university, 2012. [12] x.-s. yang, “nature-inspired metaheuristic algorithm,” second edi. frome-uk: luniver press, 2010. [13] k. s. rama rao and a. h. bin othman, “design optimization of a bldc motor by genetic algorithm and simulated annealing,” in 2007 international conferen ce on intelligent and advanced systems, 2007, pp. 854–858. [14] h. hardian syah , j. junaidi, an d y. ms, “an efficient simulated annealing algorithm for economic load dispatch problems,” telkomnika (telecommunication, comput. electron. control., vol. 11, no. 1, mar. 2013. [15] h. fang an d h. chen, “analysis and reduction of the cogging torque of flux-modulated generator for wave energy conversion,” energy procedia, vol. 158, pp. 327–332, feb. 2019 table 3. output parameters of initial and optimized design of lpmg electrical p arameters and symb ols initial design optimized design coil resistance, rph 6.1 (ω ) 1.6 (ω ) coil inductance, lph 2.40 (mh) 1.5 (mh) emf (rms), eph 110 (v) 110 (v) line current, iph 3.03 (a) 3.033 (a) electrical frequency, f 9.37 (hz) 5.64 (hz) output power, w 832 (w) 955.8 (w) copper power loss, ploss 168 (w) 44.2 (w) efficiency, η g 83.2 (%) 95.6 (%) https://doi.org/10.1049/iet-rpg.2012.0117 https://doi.org/10.1049/iet-rpg.2012.0117 https://doi.org/10.1049/iet-rpg.2012.0117 https://doi.org/10.1049/iet-rpg.2012.0117 https://doi.org/10.1016/j.renene.2015.04.039 https://doi.org/10.1016/j.renene.2015.04.039 https://doi.org/10.1016/j.renene.2015.04.039 https://doi.org/10.1109/iccep.2011.6036316 https://doi.org/10.1109/iccep.2011.6036316 https://doi.org/10.1109/iccep.2011.6036316 https://doi.org/10.1109/iccep.2011.6036316 https://doi.org/10.1109/iccep.2011.6036316 https://doi.org/10.1109/tmag.2013.2239981 https://doi.org/10.1109/tmag.2013.2239981 https://doi.org/10.1109/tmag.2013.2239981 https://doi.org/10.1109/tmag.2013.2239981 https://doi.org/10.1631/jzus.a0820224 https://doi.org/10.1631/jzus.a0820224 https://doi.org/10.1631/jzus.a0820224 https://doi.org/10.1109/icias.2014.6869479 https://doi.org/10.1109/icias.2014.6869479 https://doi.org/10.1109/icias.2014.6869479 https://doi.org/10.1109/icias.2014.6869479 https://doi.org/10.1109/tia.2015.2490629 https://doi.org/10.1109/tia.2015.2490629 https://doi.org/10.1109/tia.2015.2490629 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1109/icitacee.2016.7892433 https://doi.org/10.1063/1.4979240 https://doi.org/10.1063/1.4979240 https://doi.org/10.1063/1.4979240 https://doi.org/10.1063/1.4979240 https://doi.org/10.1109/icstc.2016.7877359 https://doi.org/10.1109/icstc.2016.7877359 https://doi.org/10.1109/icstc.2016.7877359 https://doi.org/10.1109/icstc.2016.7877359 https://doi.org/10.1109/icstc.2016.7877359 https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?article=2277&context=gradschool_theses https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?article=2277&context=gradschool_theses https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?article=2277&context=gradschool_theses https://dl.acm.org/citation.cfm?id=1628847 https://dl.acm.org/citation.cfm?id=1628847 https://doi.org/10.1109/icias.2007.4658508 https://doi.org/10.1109/icias.2007.4658508 https://doi.org/10.1109/icias.2007.4658508 https://doi.org/10.1109/icias.2007.4658508 https://doi.org/10.12928/telkomnika.v11i1.620 https://doi.org/10.12928/telkomnika.v11i1.620 https://doi.org/10.12928/telkomnika.v11i1.620 https://doi.org/10.12928/telkomnika.v11i1.620 https://doi.org/10.1016/j.egypro.2019.01.097 https://doi.org/10.1016/j.egypro.2019.01.097 https://doi.org/10.1016/j.egypro.2019.01.097 mev journal of mechatronics, electrical power, an d vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: http://www.mevjournal.com all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year and the second issue is at the end of the year. peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev has been certificated as an indonesian scientific journal by indonesian institute of sciences (lipi). mev has also been certificated by ministry of research, technology and higher education (rthe) as an online scientific journal. lipi accreditation: accreditation number: 633/au/p2mi-lipi/03/2015 acc date: 15 april 2015 valid thru: 15 april 2020. ristekdikti accreditation: accreditation number: 1/e/kpt/2015 acc date: 15 september 2015 valid thru: 21 september 2020. postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: sekretariat@mevjournal.com http://www.mevjournal.com/ mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, an d vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: http://mevjournal.com/index.ph p/mev/login need a username/password? go to registration at: http://mevjournal.com/index.ph p/mev/user/register registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at http://www.mevjournal.com. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/login http://mevjournal.com/index.php/mev/user/register http://mevjournal.com/index.php/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://www.mevjournal.com/ journal of mechatronics, electrical power, an d vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 editor-in-chief prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang 26600 pekan, pahang, malaysia prof. tapan kumar saha electrical engineering, the university of queensland st. lucia, qld-4072, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta jl. ir. sutami 36 a, surakarta, 57126, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), avda. bases de manresa, 61-73 08242 manresa (barcelona), spain prof. taufik director of electric power institute, california polytechnique san luis obispo, ca 93407, united states prof. dr. tagawa yasutaka tokyo university of agriculture and technology naka-machi 2 24 – 16, koganei – shi, tokyo, 184 – 8588, japan prof. dr. bambang riyanto school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia prof. dr. adi soeprijanto department of electrical engineering, faculty of industrial technology, institut teknologi sepuluh nopember (its) campus its keputih, surabaya 60111, indonesia dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales ainsworth building (j17) level 3, room 311b, kensington campus, australia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, po box 7916, canberra bc act 2610, australia prof. keum shik hong department of mechanical engineering, pusan national university, korea, republic of george anwar, ph.d. university of california, 101 sproul hall, berkeley, ca 94704, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, jl. ganesha no. 10, bandung 40135, indonesia riza muhida, ph.d. stkip surya jl. scientia boulevard blok u/7 summarecon gading serpong, tangerang, banten, 15810, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia advisory editor dr. endra joelianto engineering physics, bandung institute of technology jl. ganesha no. 10, bandung 40135, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') journal of mechatronics, electrical power, an d vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 associate editors (main handling editor) yanuandri putrasari, m.eng. ulsan university 93 daehak-ro, mugeo-dong, nam-gu, ulsan, south korea, republic of korea dian andriani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia tinton d atmaja, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia roni permana saputra, m.eng dyson school of design engineering robot intelligence lab imperial college, london, united kingdom aam muharam, m.t. asem, interdisciplinary graduate school of engineering kyushu university fukuoka, japan ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi bandung, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, an d vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 © 2019 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms:  authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.  authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.  authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, july 2019 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) is an international journal indexed by many internationally recognized indexers. its digital object identifier (doi) prefix is 10.14203. in this issue, six papers are published with the authors diversity came from indonesia, taiwan, japan, australia, and italia. the papers come from multidisciplinary topics including mechatronics, electrical power, and vehicular technology. they may be classified as follows. two papers are related to mechatronics which address speed control of a sensorless bldc motor and computer vision-based distance estimation for vanet application. three papers fall in electrical power topic. the first paper presents load characteristic analysis of a double-side internal coreless stator axial flux pmg. the second paper proposes a method for optimization of quasi-flat linear pm generator using simulated annealing algorithm for wec in indonesia. the third paper describes a smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control. one paper deals with vehicular technology topic i.e. exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture. since the first volume, our journal provides discretion in financial term by waiving the article processing charge.we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, december 2019 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 list of contents sensorless-bldc motor speed control with ensemble kalman filter and neural network muhammad rif’an, feri yusivar, benyamin kusumoputro ................................................................. 1-6 vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3 mulia pratama, giambattista gruosso, widodo budi santoso, achmad praptijanto .................... 7-16 load characteristic analysis of a double-side internal coreless stator axial flux pmg ketut wirtayasa, pudji irasari, muhammad kasim, puji widiyanto, muhammad fathul hikmawan .................................................................................................................................................. 17-23 exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture widiyanti, muhammad alfian mizar, christian asri wicaksana, didik nurhadi, kriya mateeke moses ......................................................................................................................................... 24-28 quasi-flat linear pm generator optimization using simulated annealing algorithm for wec in indonesia budi azhari, francisco danang wijaya ................................................................................................. 29-35 smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control kamil faqih, wahyu primadi, anik nur handayani, ari priharta, kohei arai ............................... 36-47 further articles can be found at http://www.mevjournal.com http://www.mevjournal.com/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 10, issue 1, 2019 abstracts sheet e-issn: 2088-6985 date of issues: 17 december 2019 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. muhammad rif’an a, *, feri yusivar b, benyamin kusumoputro b (a department of electrical engineering, universitas negeri jakarta, indonesia; b department of electrical engineering, universitas indonesia, indonesia ) sensorless-bldc motor speed control with ensemble kalman filter and neural network journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 1-6, 6 ill, 0 tab, 17 ref. the use of sensorless technology at bldc is mainly to improve operational reliability and play a role for wider use of bldc motors in the future. this research aims to predict load changes an d to improve the accuracy of estimation results of sensorless-bldc. in this paper, a new filtering algorithm is proposed for sen sorless brushless dc motor based on ensemble kalman filter (enkf) and neural network. the proposed enkf algorithm is used to estimate speed and rotor position, while neural network is used to estimate the disturbance by simulation. the proposed algorithm requires only the terminal voltage and the current of three phases for estimated speed an d disturbance. a model of non-linear systems is carried out for simulation. variations in disturbances such as external mechanical loads are given for testing the performance of the proposed algorithm. the experimental results show that the proposed algorithm has sufficient control with error speed of 3 % in a disturban ce of 50 % of the rated-torque. simulation results show that the speed can be tracked and adjusted accordingly either by disturbances or the presence of disturbances. (author) keywords: en semble kalman filter; neural network; sensorless; brushless dc motor . mulia pratama a, *, giambattista gruosso b, widodo budi santoso a, achmad praptijanto a (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b department of electronics, informatics and bioengineering, politecnico di milano, italy) vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3 journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 7-16, 12 ill, 4 tab, 19 ref. this research was implementing vehicle networking using wifi connection and computer vision to measure the distance of vehicles in front of a driver. in particular, this works aimed to improve a safe driving environment th us supportin g the current technology concept being developed for inter-vehicular networking, vanet, especially in its safety application such as overtaking assistance system. moreover, it can wirelessly share useful visual information such as hazard area of a road accident. in accordance with vehicleto-vehicle (v2v) concept, a vehicle required to be able to conduct networking via a wireless connection. useful data and video were the objects to be sent over the network established. the distance of a vehicle to other vehicles towards it is measured an d sent via wifi together with a video stream of the scenery experienced by the front vehicle. haar cascade classifier is chosen to perform the detection. for distan ce estimation, at least three methods have been compared in this research and foun d eviden ce that, for measuring 5 meters, the iterative methods shows 5.80. this method performs well up to 15 meters. for measuring 20 meters, p3p method shows a better result with only 0.71 meters to the ground truth . to provide a physical implementation for both the detection and distance estimation mechanism, those methods were applied in a compact small-sized vehicle-frien dly computer device the raspberry pi. the performance of th e built system then analyzed in terms of streaming latency and accuracy of distance estimation and shows a good result in measuring distance up to 20 meters. (author) keywords: computer vision; haar cascade classifier; distance estimation . ketut wirtayasa a, b, *, pudji irasari a, muhammad kasim a, c, puji widiyanto a, muhammad fathul hikmawan a (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b department of electrical engineering, national taiwan university of science an d technology, taiwan; c school of electrical engineering and telecommunications, university of new south wales, australia ) load characteristic analysis of a double-side internal coreless stator axial flux pmg journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 17-23, 9 ill, 4 tab, 13 ref. the main issue of using a permanent magnet in electric machines is the presence of cogging torque. several methods have been introduced to eliminate it, one of which is by employing a coreless stator. in this paper, the load characteristic analysis of the doubleside internal coreless stator axial flux permanent magnet generator with the specification of 1 kw, 220 v, 50 hz, 300 rpm an d 1 phase is discussed. the purpose is to learn the effect of the load to the generator performance, particularly the output power, efficien cy and voltage regulation . the design an d analysis are conducted analytically and numerically with two types of simulated loads, pure resistive and resistive-in ductive in series. each type of load provides power factor 1 and 0.85 respectively. the simulation results show that when loaded with resistive load, the generator gives a better performance at the output power (1,241 w) and efficiency (91 %), whereas a better voltage regulator (5.86 %) is achieved when it is loaded with impedance. since the difference in the value of each parameter being compared is relatively small, it can be concluded that the generator represents good performance in both loads. (author) keywords: coreless stator; axial flux permanent magnet generator; load characteristics; resistive load; resistive-inductive in series. widiyanti a, *, muhammad alfian mizar a, christian asri wicaksana b, didik nurhadi a, kriya mateeke moses c (a department of mechanical journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii engineering, state university of malang, indonesia; b bachelor program, department of mechanical engineering, state university of malang, in donesia; c graduate school of technological and vocational education, national yunlin university of science and technology, taiwan) exhaust emission s analysis of gasoline motor fueled with corncobbased bioethanol and ron 90 fuel mixture journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 24-28, 2 ill, 1 tab, 36 ref. one of the viable solutions to the fossil fuel energy crisis was to seek alternative sources of environmentally friendly energy with the same or better quality such as bioethanol. it was possible to produce bioethanol from organic waste, e.g., corncob. this research aimed to obtain the lowest exhaust emission levels of co and co 2 generated from a gasoline motor that used a mixture of bioethanol containing 96 % corncob and ron 90 fuel. this research was experimental using anova statistical data analysis method. the results showed that the lowest average of co emission s was 0.177 vol% using e100 fuel, and the highest average was 2.649 vol% using 100 % ron 90 fuel, displayin g a significant difference. the lowest average of co2 emission s was 6.6 vol% usin g e100 fuel, and the highest was 7.51 vol% using 100 % ron 90 fuel, which was insignificantly different. the mixture variation with the lowest co and co2 emission s was e100. (author) keywords: ron 90 fuel; corncob-based bioethanol; gasoline generator; co an d co2 exhaust emissions. budi azhari a, *, francisco danang wijaya b (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b department of electrical engineering and information technology, engineering faculty, universitas gadjah mada, indonesia ) quasi-flat linear pm generator optimization using simulated annealing algorithm for wec in indonesia journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 29-35, 10 ill, 3 tab, 15 ref. linear permanen t magnet generator (lpmg) is an essential component in recent wave energy converter (wec) which ex ploits wave’s heave motion. it could be classified into tubular-type, flattricore type, and quasi-flat type. in previous researches, these three models have been studied an d designed for pico-scale wec. design optimization has further been conducted for flat-tricore lpmg, by usin g simulated annealing (sa) algorithm. it modified some parameters to minimize the resulted copper loss. this paper aims to optimize a quasi-flat lpmg design by applying sa algorithm. the algorithm would readjust the initial lpmg parts dimen sion. then, the output of the optimized design would be analyzed and compared. the results showed that the optimization could reduce the copper loss by up to 73.64 % and increase the efficiency from 83.2 % to 95.57 %. for various load resistances, the optimized design also produces larger efficiency. however, the optimized design has a larger size and produces larger cogging force than the initial design. (author) keywords: design optimization; copper loss; simulated annealing; quasi-flat lpmg. kamil faqih a, *, wahyu primadi a, anik nur handayani a, ari priharta a, kohei arai b (a electrical engineering postgraduate, electrical engineering department, universitas negeri malang, indonesia; b department of information science, saga university, japan) smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control journal of mechatronics, electrical power, and vehicular technology, 2019, vol. 10, no. 1, p. 36-47, 20 ill, 2 tab, 16 ref. the utilization of renewable energy such as a photovoltaic system is the foremost alternative in transfers generated by conventional power plants, but the lack of photovoltaics is support for light intensity. the purpose of this research is to develop a pilot-scale smart grid photovoltaic system that can regulate the supply of electrical energy from either the battery or the power supply. the control system in this study uses the mamdani fuzzy logic method in determining automatic system performance. this system monitors the intensity of light an d battery which are then used as automatic safety parameters on the power supply, battery, and photovoltaic. the results of this study display the indicator results from the microcontroller in supplying electrical energy for the use of electrical loads, power supply has been served the load when the battery is in a low state which have a voltage <11 volts, the battery has been served the load when the condition of the battery is in a medium an d high condition which has a voltage of 11.5 <; ....; <13 volts. pv has been served batteries or loads when the light intensity is cloudy an d bright which have a light intensity of 3585 <; ...; <10752 lux. this system can reduce dependence on conventional energy without reducing the quality of the energy supply at load and photovoltaic system dependence on light intensity does not affect the supply of energy consumption to electrical loads . (author) keywords: renewable energy; photovoltaic systems; fuzzy logic . mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.68-80 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design muhammad fathul hikmawan a, b, agung wibowo b, *, muhammad kasim a, c a research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi jl. sangkuriang, building 20, 2nd floor, bandung, west java, 40135, indonesia b faculty of mechanical and aerospace engineering, bandung institute of technology jl. ganesa no.10, lb. siliwangi, bandung, 40132, indonesia c school of electrical engineering and telecommunications, university of new south wales 330 anzac parade, kensington nsw 2033, australia received 21 june 2021; accepted 9 september 2021; published online 31 december 2021 abstract mechanical tolerance is something that should be carefully taken into consideration and cannot be avoided in a product for manufacturing and assembly needs, especially in the design stage, to avoid excessive dimensional and geometric deviations of the components made. this paper discusses how to determine and allocate dimensional and geometric tolerances in the design of a 10 kw, 500 rpm radial flux permanent magnet generator prototype components. the electrical and mechanical design results in the form of the detailed nominal dimensions of the generator components, and the allowable air gap range are used as input parameters for tolerance analysis. the values of tolerance allocation and re-allocation process are carried out by considering the capability of the production machine and the ease level of the manufacturing process. the tolerance stack-up analysis method based on the worst case (wc) scenario is used to determine the cumulative effect on the air gap distance due to the allocated tolerance and to ensure that the cumulative effect is acceptable so as to guarantee the generator's functionality. the calculations and simulations results show that with an air gap of 1 ± 0.2 mm, the maximum air gap value obtained is 1.1785 mm, and the minimum is 0.8 mm. the smallest tolerance value allocation is 1 µm on the shaft precisely on the fsbs/srbs feature and the rotor on the rpms feature. in addition, the manufacturing process required to achieve the smallest tolerance allocation value is grinding, lapping, and polishing processes. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: permanent magnet generator; mechanical design; tolerance analysis. i. introduction the world has switched to using renewable energy in the face of the energy crisis and global warming. a permanent magnet generator (pmg) is a device that converts mechanical energy into electrical energy. the advantages of pmg are high efficiency, can be designed for low rotation, compact construction, and easy maintenance. it cannot be denied that pmg is suitable to be applied as a renewable energy power plant [1][2] as well as to be applied to electric and hybrid vehicles [3]. research and development about this generator are still being carried out now, such as research on design optimization conducted by [4] and on a wind power generation system with a magnetic generator. reference [5] seeks to optimize the power generation system of small-scale wind turbines. this system also uses a permanent magnet synchronous generator, which is connected directly to the turbine. the optimization of pmg with an interior type rotor or often called an interior permanent magnet synchronous generator (ipmsg) for applications in electric vehicles has been carried out by [6]. several studies on the design of radial type permanent magnets for renewable energy generation applications have been carried out by [7][8][9]. the result of the design is in the form of detailed dimensions of the stator and rotor. considerations regarding the tolerance of generator components in the design have not been much done, although this tolerance is very important to be taken into account at the design stage. the manufacturing process is one of the stages to realize the product design. in most cases of * corresponding author. tel: +62 812-2030-007 e-mail address: a_wibowo_m@yahoo.com https://dx.doi.org/10.14203/j.mev.2021.v12.68-80 https://dx.doi.org/10.14203/j.mev.2021.v12.68-80 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.68-80 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.68-80&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 69 generator manufacturing, mechanical tolerances inevitably occur because of the need for manufacturing and assembly processes. the tolerance influences the performance of the permanent magnet generator. the production process of permanent magnet generators and the effect on their general characteristics have been described by [10]. many studies have been carried out to investigate the impact of mechanical tolerance on electrical parameters. reference [11] has conducted a sensitivity analysis to determine its impact on the electrical parameters of pmg using the finite element method (fem) by changing the design variable in the range of tolerance values. research to investigate the effect of tolerances and manufacturing limits on permanent magnet generators with large dimensions has also been carried out by [12]. the analysis was carried out using a method that combines the fe method with direct superposition. reference [13] investigated the impact of this mechanical tolerance by measuring the magnetic flux density and the length of the air gap, as well as the magnetization and the permanent magnet size. meanwhile, reference [14] conducted research on cogging torque caused by manufacturing tolerances using analytical methods, finite element analysis (fea), and experimental methods. among the results, it is known that the tolerance of the stator inner diameter has the greatest influence on the cogging torque in the stator. while in the rotor, permanent magnet remanence is the main contributor, followed by the thickness of the magnet and the tolerance of the outer radius of the rotor. from these studies, it can be concluded that the most basic parameters of a permanent magnet electric machine are closely related to the mechanical tolerance of the air gap. tolerance stack-up analysis is a method used to determine the cumulative effect of tolerances allocated to the features of a component and to ensure that the cumulative effect is acceptable to ensure product functionality after an assembly process [15]. the tolerance stack-up analysis method is generally divided into two basic methods, namely the worst-case (wc)-based and statistical-based analysis or also known as the root sum of the square (rss). the combination method between wc and rss gave birth to the modified root sum of the square (mrss) method. the comparison of the three methods is seen from the aspect of the risk of production defects; the wc method is the lowest, followed by mrss and rss is the highest. however, if viewed from the cost side, it is the opposite, where the wc method is the highest and rss is the lowest. other basic statistical methods that have been developed are the six sigma method, genetic algorithm (ga), and monte carlo simulation. six sigma method was first introduced by the motorola company [16]. ga is an adaptive experience search algorithm based on the evolutionary ideas of natural selection. the steps of using this ga method have been described by [17]. meanwhile, the monte carlo simulation method is based on randomness. this method is used to generate random variables for analysis in various fields for nonlinear engineering models. ga and monte carlo simulation are quite powerful methods for optimization. the main drawback of both methods is that they require a lot of computation to get acceptable accuracy from statistically significant results. at the same time, the advantage is that the results obtained are more optimal than other statistical methods. several ways to overcome the weaknesses of these methods, as well as the weaknesses of the worst-case and statistical-based tolerance analysis methods, have been proposed, one of which is the analytical method introduced by [18]. another method of dimensional and geometrical tolerance analysis was introduced by [19]. the uncertainty of the dimensions and geometry of a component feature is packaged in a mathematical form with fuzzy modeling and the kinematic effect of tolerance in a product assembly is expressed by a concept called the small degrees of freedom (sdof) concept. the method commonly used for tolerance analysis is the monte carlo simulation [20]. however, a lot of software has been developed based on this method. research conducted by [21] in their paper describes the use of knowledge based engineering (kbe) to adjust tolerances based on the functional requirements of a product. the calculation and analysis of tolerances in the design of marine engine transmissions are carried out using software, that is, integrated computer aided design (cad) and computer aided tolerancing (cat) based on the monte carlo method. the results of the study indicate that kbe can be useful for driving tolerance changes towards values that ensure optimal functionality of the assembly. research on tolerance stack analysis on a francis turbine design by [22] using the worst case (wc) method with consideration of the number of products produced and the need to ensure 100 % correctness on each dimension of its components. this paper discusses how to determine and allocate tolerances in the prototype components design of a 10 kw, 500 rpm permanent magnet generator with radial flux type. the distribution flow of the relationship between the component features that play a role in compiling the key characteristics (kc) of the permanent magnet generator will be identified and mapped as an effort to control tolerances from the design stage, the production process, to the component inspection stage after production. consideration of the ability of production machines in the tolerance allocation process can provide an overview of the sequence of component manufacturing processes in real terms. tolerance stack-up analysis to determine the cumulative effect on the air gap distance due to the allocated tolerance uses manual analytical simulation based on the worst case (wc) method, where dimensional tolerances and geometry are taken into account simultaneously. this method is chosen because it is suitable for product design in the prototype stage, that is, the number of products to be made is small and the risk of manufacturing defects is the smallest. another advantage of using this method is that the analysis can be carried out easily and with simple equipment. m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 70 ii. materials and methods the results of the electrical and mechanical design in the form of details of the component's nominal dimensions, as well as the allowable range of air gaps used as input parameters for tolerance analysis, are shown in table 1. this tolerance analysis process is carried out at the final stage of mechanical design before entering the generator prototype manufacturing/production process. tolerance analysis of the 10 kw, 500 rpm permanent magnet generator prototype design was carried out in two stages, namely the identification stage and the analysis and calculation stages. the identification stage is carried out to find out the features of the components that contribute to compiling kc. the analysis and calculation stages are carried out to ensure the cumulative effect of each tolerance allocated to the component features that contribute to the kc is following the allowable requirements. a. tolerance chain the air gap is a key characteristic (kc), which is structurally located on the radial axis outside the shaft rotation. analysis of tolerance propagation that affects the value of kc can be observed from the relationship between the features of its constituent components. the structure of the generator arrangement drawing shown in figure 1 shows the identifying the features process of the components that contributes to compiling kc and the relationship between the features of these components. the red line in the figure is the relationship between the corresponding component features. the first adjustment is between the stator outer surface (sos) feature and the stator surface frame (ssf). the second adjustment is between the front surface frame (fsf) and the rear surface frame (rsf) with the frame surface end-shield (fse). the third adjustment is between the bearing surface end-shield (bse) and the outer bearing surface (obs). table 1. tolerance analysis input parameter component component's feature value (mm) stator diameter of stator outer surface (s0s) 337 diameter of stator inner surface (sis) 400 stator effective length (li) 85 rotor diameter of rotor permanent magnet surface (rpms) 323 shaft diameter of front/rearsurface bearing shaft (f/r-sbs) 75 magnet magnet height (hm) 6 magnet width (lm) 63,5 radius of magnet outer surface (mos) 167,5 radius of magnet bottom surface (mbs) 161,5 air gap air gap (g) 1 allowable deviation of air gap (δg) ± 0,2 bearing diameter of inner bearing surface (ibs) 75 diameter of outer bearing surface (obs) 130 frame diameter of stator surface frame (ssf) 400 diameter of front/rearsurface frame (f/r-sf) 412 end-shield diameter of bearing surface end-shield (bse) 130 diameter of frame surface end-shield (fse) 412 figure 1. component features identification m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 71 the fourth adjustment is between the front shaft bearing surface (fsbs) and the shaft rear bearing surface (srbs) with the inner bearing surface (ibs). the fifth adjustment is between the rotor permanent magnet surface (rpms) and the magnet bottom surface (mbs). the features of these intersecting components must be controlled by allocating dimensional tolerances and specifying precise geometric tolerances. the identification results of the component features that contribute to compiling this kc will be obtaining a schematic relationship between components to create a loop diagram. figure 2 shows a loop diagram which is a closed graphical representation of the tolerance propagation chain of each contributor/variable kc, which is useful for analysing the calculation of tolerance accumulation in the air gap. from the figure, it can be seen that there are seven variables a to g, which will affect the accumulated tolerance value in the air gap. the actual value of each of these variables will be influenced by the dimensions and geometry tolerances allocated to each contributor component feature. b. tolerance allocation the tolerance allocation process is the process of distributing the allowable requirements to kc, which in this case is the air gap to each contributor component feature. the allocated tolerances consist of dimensional tolerances and geometric tolerances. from table 1, it is known that the allowable deviation of the air gap (δg) is ± 0.2 mm. this value is obtained from the optimization results in the final stage of electrical design using the finite element analysis (fea) method. it has been confirmed that with a deviation of ± 0.2 mm in the air gap, it has been ensured that the magnetic flux distribution and cogging torque values are still within the expected design performance. if the value of the allowable air gap requirement is 1±0.2 mm, then the total accumulated dimension and geometric tolerances allocated to each contributor component feature are a maximum of 1.2 mm or a minimum of 0.8 mm. the first step of tolerance allocation is to consider the ability of the production machine, in particular, the ability of the machine to achieve the allocated tolerance value. figure 3 shows a graph of figure 2. loop diagram analysis of air gap variation figure 3. tolerance chart in manufacturing process selection [23] m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 72 the tolerance values that can be achieved using some commonly used manufacturing process/machine methods. the process of making magnets is carried out by a powder metallurgy process followed by a surface finishing process by a grinding process. the minimum tolerance value allocation is 0.02 mm. this magnetic tolerance value is assumed to be a fixed value due to the consideration that the manufacturing process is relatively difficult and expensive. the process of making the stator is in electro machining process with wire cutting. in the process of making the stator, what must be considered is to maintain the insulating layer on the surface of each laminate layer so that it is not damaged. therefore, additional finishing processes obtaining tight tolerance values are not recommended. for this reason, the stator tolerance value is also assumed to be a fixed value, with the minimum allocation value being 0.02 mm, according to the maximum capacity of the wire cut machine. the manufacturing process for other components such as the rotor-shaft, generator body/frame, and end-shield cover is carried out by conventional machining processes. to achieve the tolerance value, it can be done with a finishing process using grinding, lapping, or polishing so that the tolerance allocation process for these components will be more flexible. the second step of the tolerance allocation process is to determine the type of fits between the contributing component’s features in terms of function. each type of fits between the contributing component’s features is shown in table 2. after knowing each type of adjustment, the dimensional tolerance value of the corresponding features can be determined using the principle of the base hole system. table 3 shows a base hole-based dimensional tolerance value selection system according to the iso 286-1.2010 standard. in table 2, in the 5th fits between the rpms and mbs features there is no fits type because it is not included in the fits type based on the base hole or base shaft fits. so, the determination of the tolerance value that is allocated is only based on the ability of the production machine. the third step is to allocate geometric tolerances to each component feature that contributes to the accumulation of kc tolerances. in determining the type of geometric tolerance, two things must be considered, namely the air gap requirements and the assembly requirements between components in terms of geometry. judging from the air gap requirements, the position of the rotating axis of the rotor with the stator must be one axis / coaxial. these conditions must be able to be maintained by the bearing, body cover, and generator body together so that the air gap distance will always be the same along the surface between the rotor and the stator. meanwhile, if viewed from the aspect of assembly between components, it must be considered is the tolerance of the shape, position, or location of the component features that will match each other. for example, the geometric tolerance between the hole and the axis, then at least the spherical or cylindrical tolerance between the two must be taken into account. c. component feature deviation analysis the deviation analysis process is carried out by simulating the deviation of the contributor component features after the dimensions and geometry tolerances have been allocated. the simulation will be useful to make it easier to formulate calculations in finding variable values. the simulation process can be done using any cad software, but in this study, the software used is solidwork. figure 4 shows the allocation of geometric tolerances on the stator for sos and sis features. table 2. fits types between component features no fits function feature type 1 sos-ssf transition fit the stator must be firmly attached to the frame, but can still be removed for maintenance purposes 2 fsf-fse/rsf-rse transition fit the end shield must be firmly attached to the body, but can still be removed for maintenance purposes 3 bse-obs clearance fit bearing load is balanced with inner ring/rotating shaft section and static outer ring 4 fsbs/srbs-ibs interference fit bearing load is balanced with inner ring/rotating shaft section and static outer ring ring 5 rpms-mbs no fixed permanently table 3. base hole fit selection system basic hole tolerance classes for shafts clearance fits transition fits interference fits h6 g5 h5 js5 k5 m5 n5 p5 h7 f6 g6 h6 js6 k6 m6 n6 p6 r6 s6 t6 u6 x6 h8 e7 f7 h7 js7 k7 m7 s7 u7 d8 e8 f8 h8 h9 d8 e8 f8 h8 h10 b9 c9 d9 e9 f9 h9 h11 b11 c11 d11 h10 m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 73 a proper understanding of the allocated geometry tolerance is crucial in the process of simulating the feature deviation. from figure 4, the sos feature axis was chosen as the primary datum because the surface of this feature will later sit on the frame. this feature surface is allocated a cylindrical tolerance, which means that every point on the feature surface must be in a space bounded by two coaxial imaginary cylindrical casings spaced as the value of the tolerance (cyl). in the sis feature, the coaxiality geometry tolerances for datum a and cylindricity tolerance are allocated. the meaning of coaxiality tolerant is that each point of observation of the centre circle diameter/axis of the sis features must be within the tolerance area in the form of a cylinder with a diameter value of the tolerance (coax), which is made based on the centre axis of the diameter of the sos feature/datum a. then, a simulation drawing of the deviation of each feature is made based on understanding the meaning of its geometric tolerance zone. the deviation simulation can be seen in figure 5. the maximum deviation condition for the sis feature occurs when the centre point of the feature experiences a maximum shift from its coaxial tolerance value (coax) and every point on the feature surface is at the upper limit of its cylindrical tolerance value (cyl). the minimum deviation of the sis features occurs when the axis/centre point of the feature circle is in accordance with datum a/coaxiality tolerance is 0 mm (coax = 0) and every point on the inner diameter surface is at the lower limit of its cylindrical tolerance value (cyl). for the sos feature, the maximum deviation occurs when every point on the outer diameter surface is at the upper limit of the cylindrical tolerance value, while the minimum deviation occurs when every point on the surface of the outer diameter is at the lower limit of the cylindrical tolerance value (cyl). the next geometric tolerance allocation is also allocated to other components. figure 6 is an allocation of geometric tolerances in the frame for fsf/rsf and ssf features. the fsf and rsf feature axes are used together as the primary h-i datum. the three features are equally allocated coaxiality and cylindrical tolerances. aberration simulations are depicted in figure 7 for deviations in fsf/rsf features. the minimum and maximum deviation conditions that occur in the fsf/rsf feature are similar to the sis feature on the stator component. likewise, the deviation conditions that occur in ssf features as shown in figure 8. figure 4. allocation of stator geometry tolerances on sos and sis features figure 5. stator features deviation simulation figure 6. allocation of geometry tolerances on the frame m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 74 in the body cover/end-shield component, the allocation of geometric tolerances can be seen in figure 9. the bse feature axis is selected as the primary datum with the symbol g. this feature is allocated a cylindrical tolerance. for the fse feature, the coaxiality tolerance for datum g and cylindricity is allocated. the minimum and maximum deviation conditions that occur in the bse feature are similar to the condition of the sos feature on the stator component. meanwhile, the deviation condition of the fse feature has similarities with the sis stator and fsf/rsf frame features. figure 10 shows a simulation of the deviation of the bse and fse features. for the tolerance value, the dimensions and geometry of the standard bearing components are selected based on the bearing specifications used. in this generator design, the bearing used is a deep groove ball bearing type 6215, with nominal dimensions of 75 mm inner diameter, 130 mm outer diameter and 25 mm thickness. the tolerance value can be selected according to the bearing class. table 4 shows the tolerance specifications for ball bearings according to the bearing class. the maximum and minimum deviations of the obs and ibs bearing features can be seen in figure 11. the deviation conditions of these features are similar to the sos features on the stator, where the maximum deviation occurs when every point on the outer diameter surface is at the upper limit of its geometric tolerance value. and vice versa for the minimum conditions. from the simulation of the maximum and minimum deviation conditions, an equation can be formulated to calculate the deviation value of these features. to distinguish figure 7. fsf/rsf feature deviation simulation figure 8. ssf feature deviation simulation figure 9. allocation of geometry tolerances on bse dan fse end-shield features m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 75 feature deviations from components that have two features under review, the smaller diameter features is given the symbol "ftr" and the larger diameter features are given the symbol "ftr". then the equations for the minimum and maximum deviation of features are as follows: 𝐹𝐹𝐹𝑚𝑚𝑚 = 𝑓𝐹𝐹𝑚𝑚𝑚 = (𝐷𝑛𝑛𝑛+𝑡′−𝑐𝑐𝑐) 2 (1) 𝐹𝐹𝐹𝑚𝑚𝑚 = 𝑓𝐹𝐹𝑚𝑚𝑚 = (𝐷𝑛𝑛𝑛+𝑡+𝑐𝑐𝑚𝑚+𝑐𝑐𝑐) 2 (2) where 𝐹𝐹𝐹𝑚𝑚𝑚 is minimum deviation of larger diameter features, 𝐹𝐹𝐹𝑚𝑚𝑚 is maximum deviation of larger diameter features, 𝑓𝐹𝐹𝑚𝑚𝑚 is minimum deviation of smaller diameter features, 𝑓𝐹𝐹𝑚𝑚𝑚 is maximum deviation of smaller diameter features, dnom is nominal value of feature diameter, t is dimensional tolerance of the upper limit of the feature, and t' is the lower limit, cyl is cylindrical tolerance, coax is coaxiality tolerance. furthermore, to find the nominal value of the variables a, b, c, and d, the maximum condition of the variable material (v2mmc) and the minimum condition of the stator material (v2lmc) are calculated first. because the variable distance a to d figure 10. bse dan fse feature deviation simulation figure 11. obs dan ibs feature deviation simulation table 4. bearing tolerance specifications [24] tolerance features class 0 class 6 class 5 class 4 class 2 (+) (-) (+) (-) (+) (-) (+) (-) (+) (-) (μm) dimension inner ring 0 -15 0 -12 0 -9 0 -7 0 -4 outer ring 0 -18 0 -15 0 -11 0 -9 0 -5 width 0 -120 0 -120 0 -120 0 -120 0 -120 geometry inner ring 15 10 5 4 2,5 outer ring 25 13 8 5 4 side inner no no 8 4 2,5 side outer no no 10 5 4 m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 76 is the distance between the two component features, the v2mmc and v2lmc can be calculated respectively by the equations: 𝑉2𝑀𝑀𝑀 = (𝐹𝑡𝐹𝑛𝑎𝑎−𝑓𝑡𝐹𝑛𝑚𝑛) 2 (3) 𝑉2𝐿𝑀𝑀 = (𝐹𝑡𝐹𝑛𝑚𝑛−𝑓𝑡𝐹𝑛𝑎𝑎) 2 (4) furthermore, the nominal value of the variables a, b, c and d (va-d) as well as the bilateral equal tolerance value (ta-d) can be obtained by the following equations: 𝑉𝐴−𝐷 = (𝑉2𝑀𝑀𝑀+𝑉2𝐿𝑀𝑀) 2 (5) 𝑇𝐴−𝐷±= (𝑉2𝑀𝑀𝑀−𝑉2𝐿𝑀𝑀) 2 (6) each of the shaft and rotor components has only one feature to be reviewed because the other features are the axes of the feature. for the allocation of geometry tolerances for the shaft fsbs/srbs feature and the rotor rpms feature, see figure 12. the shaft fsbs/srbs feature axes are together used as primary datums a-b. each axis feature is allocated a coaxiality geometry tolerance to the a-b datum and the cylindrical. furthermore, a simulation of the deviation of these features is carried out. figure 13 shows a simulation of the deviation of the features of the shaft and rotor components. the maximum and minimum deviation conditions that occur also have similarities with the features of the sis stator. so to calculate the maximum deviation (ftrmax) and minimum (ftrmin) of the shaft fsbs/srbs feature and the rotor rpms feature, one can use equations (1) and 2. meanwhile, the nominal value of the variables e and f (ve-f) and the bilateral equal tolerance value (te-f) can be directly calculated by the following equations: 𝑉𝐸−𝐹 = ((𝐹𝑡𝐹𝑛𝑎𝑎+𝐹𝑡𝐹𝑛𝑚𝑛) 2 (7) 𝑇𝐴−𝐷±= ((𝐹𝑡𝐹𝑛𝑎𝑎−𝐹𝑡𝐹𝑛𝑚𝑛) 2 (8) for permanent magnet components, the allocation of geometric tolerances can be seen in figure 14, while the deviation simulation of the outer surface (mos) and bottom surface (mbs) magnets can be seen in figure 15. from the deviation simulation, if the geometry tolerance allocated to the surface of the two features is the surface accuracy (surf), the maximum (rosmax) and minimum (rosmin) deviations of the mos and mbs features can be calculated by the following equations: 𝑅𝑅𝑅𝑚𝑚𝑚 = 𝐷𝑚𝑐𝑚 + 𝐹′ + ( 1 2 𝑅𝑠𝐹𝑓) (9) 𝑅𝑅𝑅𝑚𝑚𝑚 = 𝐷𝑚𝑐𝑚 − 𝐹 − ( 1 2 𝑅𝑠𝐹𝑓) (10) figure 12. allocation of geometry tolerances fsbs/srbs shaft feature and rpms rotor features figure 13. fsbs/srbs shaft features and rpms rotor features deviation simulation m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 77 the value of the loop variable g and its tolerance is calculated by first calculating the maximum material condition (gmmc) and the minimum material condition (glmc) magnet, with the equations: 𝐺𝑀𝑀𝑀 = (𝑅𝑐𝑅𝑛𝑎𝑎+𝑅𝑚𝑅𝑛𝑚𝑛) 2 (11) 𝐺𝐿𝑀𝑀 = (𝑅𝑐𝑅𝑛𝑚𝑛−𝑅𝑚𝑅𝑛𝑎𝑎) 2 (12) so, that the nominal value of the variable (vg) and its tolerance (tg) can be obtained by the following equations: 𝑉𝐺 = (𝐺𝑀𝑀𝑀+𝐺𝐿𝑀𝑀) 2 (13) 𝑇𝐺±= (𝐺𝑀𝑀𝑀−𝐺𝐿𝑀𝑀) 2 (14) d. calculation of accumulated tolerance the accumulated tolerance/total tolerance (tt) on the air gap is calculated using the worst-case method, with the following equation: 𝑇𝐹 = 𝑇𝑅𝑇1 + 𝑇𝑅𝑇2 + ⋯ + 𝑇𝑅𝑇𝑚 = ∑ 𝑇𝑅𝑇𝑚 𝑚 𝑚=1 (15) where ±t𝑅𝑇𝑖 is the tolerance value of the ith dimension in equal-bilateral format. according to the loop diagram in figure 2, the direction of tolerance propagation for variables with a downward vector direction (vy), namely a, b, f and g is given a negative sign (-), because if the distance value of each variable is increased, it will cause a reduction in the air gap distance. on the other hand, the variables with upward vector directions (vx), namely c, d and e, are given a positive sign (+) because if the distance of each variable increases, it will cause an increase in the distance of the air gap. thus, the variation of the air gap distance can be calculated by the equations: 𝑔𝑚𝑚𝑚 = �∑𝑉𝑚 − ∑𝑉𝑐� + 𝑇𝐹 (16) 𝑔𝑚𝑚𝑚 = �∑𝑉𝑚 − ∑𝑉𝑐� − 𝑇𝐹 (17) where gmax is the maximum air gap distance and gmin is the minimum air gap distance. e. tolerance resizing/value re-allocation process this tolerance accumulation analysis process is repetitive. the process of re-allocating/resizing the tolerance value of each component feature will continue to be carried out until the tolerance accumulation value in the air gap that meets the allowable requirements is obtained. the resizing method is carried out in order of priority in accordance with the consideration of the level of ease of the manufacturing process. the priority of resizing the tolerance value is carried out on the component features sequentially in table 5. iii. results and discussions based on the fits type between the features of the components and the type of geometry tolerance allocated to the component features as well as considering the capabilities of the production machine, the dimensional tolerance values and the initial geometry of the features are allocated, which are shown in table 6. from the initial tolerance allocation value, the calculation process for each variable value and tolerance as well as the accumulated tolerance value for the air gap is carried out. the calculation results from the initial allocation can be seen in table 7. the minimum air gap distance value is 0.612 mm and the maximum is 1.335 mm, where this value does not meet the allowable air gap distance requirements. figure 14. allocation of magnetic geometry tolerance figure 15. magnet features deviation simulation table 5. resizing priority order priority component features 1 rotor rpms 2 shaft fsbs-rsbs 3 end-shield fse 4 frame fsf-rsf 5 end-shield ssf 6 bearing ─ m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 78 the re-allocation/resizing process of tolerance values is carried out in order of priority in accordance with the consideration of the level of ease of the manufacturing process in table 5. figure 16 shows a graph of the resizing process of component feature tolerance allocation values. the first iteration shows the initial allocation value and in the last iteration, the final allocation value is obtained, where the accumulated air gap distance is obtained in accordance with the permit requirements. figure 17 shows the process of changing the value of the maximum and minimum air gap variations in accordance with the resizing process/changes in the allocated tolerance value. the final tolerance value allocated to each contributor component feature can be seen in table 8, while the results of the calculation of the final tolerance allocation can be seen in table 9. the value of the variation of the air gap distance has met the requirements, namely 1.1785 mm for the maximum value and 0.8 mm for the minimum value. the evaluation of the final result of the tolerance value allocation is that the smallest tolerance value allocated is 1μm for the shaft fsbs/srbs feature and table 6. initial allocation value of tolerance component features nominal dimension (mm) dimension tolerance (mm) geometry tolerance (mm) (t) coaxciality cylindricity profile runout total runout (t) (t') (coax) (cyl) (surf) (ro) (tro) stator sos ø400 0 -0,02 ─ 0,02 ─ ─ ─ sis ø337 0,05 -0,05 0,03 0,02 ─ ─ ─ shaft fsbs-srbs ø75 0,015 0,002 0,01 0,02 ─ ─ ─ rotor rpms ø323 0,05 -0,05 0,01 ─ ─ ─ 0,02 magnet mos r167,5 0,025 0,025 ─ ─ 0,02 mbs r161,5 0,025 0,025 ─ ─ 0,02 bearing obs ø130 0 -0,018 ─ ─ ─ 0,025 ─ ibs ø75 0 -0,015 ─ ─ ─ 0,015 ─ frame fsf ø412 0,013 0,07 0,03 0,02 ─ ─ ─ ssf ø400 0,06 0 0,03 0,02 ─ ─ ─ end-shield fse ø412 0 -0,06 0,03 0,02 ─ ─ ─ bse ø130 0,04 0 0 0,01 ─ ─ ─ table 7. calculation of the initial tolerance allocation variable down vector (-) (mm) up vector (+) (mm) equal bilateral tolerance (mm) component a 31,4875 0,0575 stator b 5,99825 0,05625 frame c 140,9825 0,0475 end-shield d 27,49925 0,02825 bearing e 37,50675 0,01575 shaft f 161,5025 0,0625 rotor g 6 0,07 magnet total 204,98825 205,9885 0,33775 maximum air gap (mm) 1,338 minimum air gap (mm) 0,6625 figure 16. tolerance value resizing process m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 79 the rotor rpms feature. with this tolerance value, the required manufacturing process is the finishing process from grinding to polishing. the results obtained from this method, when compared with the known wc method, are still the same. however, when compared to the ease of determining which geometric tolerances influence/contribute to kc, this method is easier to determine, that is by simulating the component feature deviation due to the allocated geometry tolerance. in addition, with this method, the required manufacturing process can be known earlier during the tolerance value allocation process by considering the machine's capabilities. meanwhile, compared to statistical-based methods, the results of calculations using this method have a greater total accumulated value. however, as it is known that the weakness of the statistical method to calculate the total tolerance value, namely the possibility of defective products, will be greater than using the wc-based method. iv. conclusion this paper has presented a method used to determine and allocate tolerances in designing a prototype component of a radial flux type permanent magnet generator. the calculations and simulations results show that with an air gap of 1 ± figure 17. the process of calculating the value of the accumulated air-gap tolerance variation table 8. final tolerance allocation value component features nominal dimension (mm) dimension tolerance (mm) geometry tolerance (mm) (t) coaxciality cylindricity profile runout total runout (t) (t') (coax) (cyl) (surf) (ro) (tro) stator sos ø400 0 -0,02 ─ 0,02 ─ ─ ─ sis ø337 0,02 -0,02 0,02 0,02 ─ ─ ─ shaft fsbs-srbs ø75 0,02 0,01 0,001 0,001 ─ ─ ─ rotor rpms ø323 0,02 0,02 0,001 ─ ─ ─ 0,001 magnet mos r167,5 0,02 0,02 ─ ─ 0,02 mbs r161,5 0,02 0,02 ─ ─ 0,02 bearing obs ø130 0 -0,018 ─ ─ ─ 0,025 ─ ibs ø75 0 -0,015 ─ ─ ─ 0,015 ─ frame fsf ø412 -0,014 0 0,004 0,004 ─ ─ ─ ssf ø400 0,06 -0,039 0,004 0,004 ─ ─ ─ end-shield fse ø412 0 -0,02 0,003 0,003 ─ ─ ─ bse ø130 0,02 -0,02 0 0,005 ─ ─ ─ table 9. calculation of the final tolerance allocation variable down vector (-) (mm) up vector (+) (mm) equal bilateral tolerance (mm) component a 31,49 0,04 stator b 6,02075 0,01975 frame c 140,99325 0,01725 end-shield d 27,49925 0,02825 bearing e 37,50775 0,00325 shaft f 161,50025 0,02075 rotor g 6 0,06 magnet total 205,011 206,00025 0,18925 maximum air gap (mm) 1,1785 minimum air gap (mm) 0,8 m.f. hikmawan et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 68-80 80 0.2 mm, the maximum air gap value obtained is 1.1785 mm and the minimum is 0.8 mm. the smallest tolerance value allocation is 1 µm on the shaft precisely on the fsbs/srbs feature and the rotor on the rpms feature. the manufacturing finishing process needed to achieve the smallest tolerance value on the component features is grinding, lapping, and polishing processes. acknowledgment our gratitude goes to mrs. pudji irasari, m.sc.rer.nat for the permission given to use the electrical design of the generator as the material for this research and to publish this paper. we would also like to thank those who have helped and supported in the process of preparing this manuscript. declarations author contribution muhammad fathul hikmawan contributed as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] n. harkati, l. moreau, m. zaim, and j. f. charpentier, "low speed doubly salient permanent magnet generator with passive rotor for a tidal current turbine," in 2013 international conference on renewable energy research and applications (icrera), 2013, pp. 528-533. [2] l. wei, t. nakamura, and k. imai, "development and optimization of low-speed and high-efficiency permanent magnet generator for micro hydro-electrical generation system," renewable energy, vol. 147, pp. 1653-1662, 2020. [3] a. al-adsani and n. schofield, "hybrid permanent magnet generators for electric vehicle applications," in 2009 ieee international electric machines and drives conference, 2009, pp. 1754-1761. [4] t. d. p. m. bazzo, j. f. kölzer, r. carlson, f. wurtz, and l. gerbaud, "multiphysics design optimization of a permanent magnet synchronous generator," ieee transactions on industrial electronics, vol. 64, pp. 9815-9823, 2017. [5] h. z. agrebi, n. benhadj, m. chaieb, f. sher, r. amami, r. neji, et al., "integrated optimal design of permanent magnet synchronous generator for smart wind turbine using genetic algorithm," energies, vol. 14, p. 4642, 2021. [6] d.-k. lim, s.-y. jung, k.-p. yi, and h.-k. jung, "a novel sequential-stage optimization strategy for an interior permanent magnet synchronous generator design," ieee transactions on industrial electronics, vol. 65, pp. 1781-1790, 2017. [7] p. irasari, h. s. alam, and m. kasim, "analytical design method of 3 kw, 200 rpm permanent magnet generator for renewable energy power plant applications," ketenagalistrikan dan energi terbarukan, vol. 12, pp. 55-66, 2013. [8] a. abdoos, m. moazzen, and s. hosseini, "optimal design of an exterior-rotor permanent magnet generator for wind power applications ," journal of operation and automation in power engineering, 2020. [9] r. iracheta-cortez, w. durante-gomez, and j. dorrego-portela, "designing a radial-type multi-pole permanent magnet synchronous generator (pmsg) for horizontal axis wind turbines," in 2017 ieee 37th central america and panama convention (concapan xxxvii), 2017, pp. 1-9. [10] g. ombach and j. junak, "design of pm brushless motor taking into account tolerances of mass production-six sigma design method," in 2007 ieee industry applications annual meeting, 2007, pp. 2139-2146. [11] h. khreis, a. deflorio, k. voelz, and b. schmuelling, "sensitivity analysis on electrical parameters for permanent magnet synchronous machine manufacturing tolerances in ev and hev," in 2016 ieee transportation electrification conference and expo (itec), 2016, pp. 1-5. [12] d. palani, z. azar, a. thomas, z. zhu, and d. gladwin, "modeling technique for large permanent magnet generators accounting for manufacturing tolerances and limitations," in 2016 xxii international conference on electrical machines (icem), 2016, pp. 452-458. [13] p. eklund and s. eriksson, "air gap magnetic flux density variations due to manufacturing tolerances in a permanent magnet synchronous generator," in 2016 xxii international conference on electrical machines (icem), 2016, pp. 93-99. [14] j. ou, y. liu, r. qu, and m. doppelbauer, "experimental and theoretical research on cogging torque of pm synchronous motors considering manufacturing tolerances," ieee transactions on industrial electronics, vol. 65, pp. 3772-3783, 2017. [15] w. p. syam, "toleransi dimensi dan geometri-analisis rantai variasi dalam proses perakitan produk," ina-rxiv, july 2, 2019. [16] t. pyzdek, the six sigma project planner a step-by-step guide to leading a six sigma project through dmaic, mcgraw-hilll education, 1st edition, april 22, 2003. [17] a. f. shukur, n. s. chin, s. norhayati, and b. n. taib, "design and optimization of valveless micropumps by using genetic algorithms approach," journal of engineering science and technology, vol. 10, pp. 1293-1309, 2015. [18] g. chongying, l. jianhua, and j. ke, "efficient statistical analysis of geometric tolerances using unified error distribution and an analytical variation model," the international journal of advanced manufacturing technology, vol. 84, pp. 347-360, 2016. [19] s. khodaygan and m. movahhedy, "a comprehensive fuzzy feature-based method for worst case and statistical tolerance analysis," international journal of computer integrated manufacturing, vol. 29, pp. 42-63, 2016. [20] y.-k. kim, j.-p. hong, and j. hur, "torque characteristic analysis considering the manufacturing tolerance for electric machine by stochastic response surface method," ieee transactions on industry applications, vol. 39, pp. 713-719, 2003. [21] c. renzi, a. ceruti, and f. leali, "integrated geometrical and dimensional tolerances stack-up analysis for the design of mechanical assemblies: an application on marine engineering," computer-aided design and applications, vol. 15, pp. 631-642, 2018. [22] i. djodikusumo, k. suherman, and p. b. a. oken, "tolerance stack analysis in francis turbine design," journal of engineering and technological sciences, vol. 42, pp. 73-90, 2010. [23] m. ashby, "processes and process selection, materials selection in mechanical design," ed: elsevier ltd, amsterdam, 2011. [24] n. catalogue, “ball and roller bearings,” ntn corporation, 2001. https://mev.lipi.go.id/ https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1109/icrera.2013.6749811 https://doi.org/10.1016/j.renene.2019.09.049 https://doi.org/10.1016/j.renene.2019.09.049 https://doi.org/10.1016/j.renene.2019.09.049 https://doi.org/10.1016/j.renene.2019.09.049 https://doi.org/10.1109/iemdc.2009.5075440 https://doi.org/10.1109/iemdc.2009.5075440 https://doi.org/10.1109/iemdc.2009.5075440 https://doi.org/10.1109/iemdc.2009.5075440 https://doi.org/10.1109/tie.2017.2726983 https://doi.org/10.1109/tie.2017.2726983 https://doi.org/10.1109/tie.2017.2726983 https://doi.org/10.1109/tie.2017.2726983 https://doi.org/10.3390/en14154642 https://doi.org/10.3390/en14154642 https://doi.org/10.3390/en14154642 https://doi.org/10.3390/en14154642 https://doi.org/10.1109/tie.2017.2739685 https://doi.org/10.1109/tie.2017.2739685 https://doi.org/10.1109/tie.2017.2739685 https://doi.org/10.1109/tie.2017.2739685 https://doi.org/10.1109/tie.2017.2739685 http://203.189.89.76/index.php/ket/article/view/91 http://203.189.89.76/index.php/ket/article/view/91 http://203.189.89.76/index.php/ket/article/view/91 http://203.189.89.76/index.php/ket/article/view/91 https://dx.doi.org/10.22098/joape.2021.7337.1532 https://dx.doi.org/10.22098/joape.2021.7337.1532 https://dx.doi.org/10.22098/joape.2021.7337.1532 https://dx.doi.org/10.22098/joape.2021.7337.1532 https://doi.org/10.1109/concapan.2017.8278479 https://doi.org/10.1109/concapan.2017.8278479 https://doi.org/10.1109/concapan.2017.8278479 https://doi.org/10.1109/concapan.2017.8278479 https://doi.org/10.1109/concapan.2017.8278479 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/07ias.2007.324 https://doi.org/10.1109/icelmach.2016.7732565 https://doi.org/10.1109/icelmach.2016.7732565 https://doi.org/10.1109/icelmach.2016.7732565 https://doi.org/10.1109/icelmach.2016.7732565 https://doi.org/10.1109/icelmach.2016.7732565 https://doi.org/10.1109/icelmach.2016.7732511 https://doi.org/10.1109/icelmach.2016.7732511 https://doi.org/10.1109/icelmach.2016.7732511 https://doi.org/10.1109/icelmach.2016.7732511 https://doi.org/10.1109/tie.2017.2758760 https://doi.org/10.1109/tie.2017.2758760 https://doi.org/10.1109/tie.2017.2758760 https://doi.org/10.1109/tie.2017.2758760 https://doi.org/10.1109/tie.2017.2758760 https://doi.org/10.31227/osf.io/r9h8y https://doi.org/10.31227/osf.io/r9h8y http://196.223.158.148/bitstream/handle/123456789/2153/131.pdf?sequence=1&isallowed=y http://196.223.158.148/bitstream/handle/123456789/2153/131.pdf?sequence=1&isallowed=y http://196.223.158.148/bitstream/handle/123456789/2153/131.pdf?sequence=1&isallowed=y https://jestec.taylors.edu.my/vol%2010%20issue%2010%20october%202015/volume%20(10)%20issue%20(10)%201293-1309.pdf https://jestec.taylors.edu.my/vol%2010%20issue%2010%20october%202015/volume%20(10)%20issue%20(10)%201293-1309.pdf https://jestec.taylors.edu.my/vol%2010%20issue%2010%20october%202015/volume%20(10)%20issue%20(10)%201293-1309.pdf https://jestec.taylors.edu.my/vol%2010%20issue%2010%20october%202015/volume%20(10)%20issue%20(10)%201293-1309.pdf https://doi.org/10.1007/s00170-015-7577-1 https://doi.org/10.1007/s00170-015-7577-1 https://doi.org/10.1007/s00170-015-7577-1 https://doi.org/10.1007/s00170-015-7577-1 https://doi.org/10.1007/s00170-015-7577-1 https://doi.org/10.1080/0951192x.2014.1002808 https://doi.org/10.1080/0951192x.2014.1002808 https://doi.org/10.1080/0951192x.2014.1002808 https://doi.org/10.1080/0951192x.2014.1002808 https://doi.org/10.1109/tia.2003.811777 https://doi.org/10.1109/tia.2003.811777 https://doi.org/10.1109/tia.2003.811777 https://doi.org/10.1109/tia.2003.811777 https://doi.org/10.1080/16864360.2018.1441229 https://doi.org/10.1080/16864360.2018.1441229 https://doi.org/10.1080/16864360.2018.1441229 https://doi.org/10.1080/16864360.2018.1441229 https://doi.org/10.1080/16864360.2018.1441229 https://core.ac.uk/download/pdf/291478536.pdf https://core.ac.uk/download/pdf/291478536.pdf https://core.ac.uk/download/pdf/291478536.pdf https://core.ac.uk/download/pdf/291478536.pdf https://scholar.google.com/scholar?hl=id&as_sdt=0%2c5&q=%5b23%5d%09m.+ashby%2c+%22processes+and+process+selection%2c+materials+selection+in+mechanical+design%2c%22+ed%3a+elsevier+ltd%2c+amsterdam%2c+2011&btng= https://scholar.google.com/scholar?hl=id&as_sdt=0%2c5&q=%5b23%5d%09m.+ashby%2c+%22processes+and+process+selection%2c+materials+selection+in+mechanical+design%2c%22+ed%3a+elsevier+ltd%2c+amsterdam%2c+2011&btng= https://scholar.google.com/scholar?hl=id&as_sdt=0%2c5&q=n.+catalogue%2c+%22ball+and+roller+bearings%2c%22+ntn+corporation%2c+2001+&btng= https://scholar.google.com/scholar?hl=id&as_sdt=0%2c5&q=n.+catalogue%2c+%22ball+and+roller+bearings%2c%22+ntn+corporation%2c+2001+&btng= i. introduction ii. materials and methods a. tolerance chain b. tolerance allocation c. component feature deviation analysis d. calculation of accumulated tolerance e. tolerance resizing/value re-allocation process iii. results and discussions iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. yusie rizal, phd cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia suprapto, ph.d departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 viii kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia alexander christantho budiman ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. ph.h. mustafa no. 23, bandung, jawa barat, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. rina ristiana technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. andry masri, m.sn department of product design, faculty of art and design, institut teknologi nasional jl. ph.h. mustofa no.23, bandung, jawa barat, indonesia dr. eng., aam muharam research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. anto tri sugiarto, m.eng technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. deni shidqi khaerudini, s.si.,m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 ix kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia aditya nugraha, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani,m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. natalita maulani nursam research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi azhari, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. anwar muqorobin, m.t research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sudirja, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia veny luvita, m.t technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia irwan purnama m.sc.eng technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 x publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xi 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiv presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xv instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvi • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor , city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software mev journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2019.v10.7-16 2088-6985 / 2087-3379 ©2019 research centre for electrical power an d mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (lipi) 633/au/p2mi-lipi/03/2015 and (ristekdikti) 1/e/kpt/2015. vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3 mulia pratama a, *, giambattista gruosso b, widodo budi santoso a, achmad praptijanto a a research centre for electrical power an d mechatronic s, in donesian institute of sciences jl. cisitu no. 154d, bandung, 40135, in donesia b department of electronics, informatics and bioengineerin g, politecnico di milano via ponzio 34/5, 20133, milano, italia received 1 march 2019; accepted 2 december 2019; published online 17 december 2019 abstract this research was implementing vehicle networking using wifi connection and computer vision to measure the distance of vehicles in front of a driver. in particular, this works aimed to improve a safe driving environment thus supporting the current technology concept being developed for inter-vehicular networking, vanet, especially in its safety application such as overtaking assistance system. moreover, it can wirelessly share useful visual information such as hazard area of a road accident. in accordance with vehicle-to-vehicle (v2v) concept, a vehicle required to be able to conduct networking via a wireless connection. useful data and video were the objects to be sent over the network established. the distance of a vehicle to other vehicles towards it is measured and sent via wifi together with a video stream of the scenery experienced by the front vehicle. haar cascade classifier is chosen to perform the detection. for distance estimation, at least three methods have been compared in this research and found evidence that, for measuring 5 meters, the iterative methods shows 5.80. this method performs well up to 15 meters. for measuring 20 meters, p3p method shows a better result with only 0.71 meters to the ground truth. to provide a physical implementation for both the detection and distance estimation mechanism, those methods were applied in a compact small-sized vehicle-friendly computer device the raspberry pi. the performance of the built system then analyzed in terms of streaming latency and accuracy of distance estimation and shows a good result in measuring distance up to 20 meters. ©2019 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: computer vision; haar cascade classifier; distance estimation. i. introduction video streaming over the inter-vehicular network promises an improvement in road safety and driverenvironment safety driving [1]. a vehicle with an intelligent transportation system and a camera adopted able to records surrounding geographic scenes of a highway and events during driving session and stream the video and data to other smart vehicles nearby through the advantage of an inter-vehicular network named vanet [2] for example. in vanet video and data streamed include the information of the road scenery and vehicle motion such as vehicle position, distance, and speed. retrieving the relative position i.e. the longitudinal distance of a vehicle in front of the driver by the camera would be the main objective of this work. with this technology enabled in a vehicle, it encourages the decision making by drivers to for example overtaking a road lead [3] thus aiming to support the service of the basic safety application built based on sae j2735 bsm via wifi or dsrc/wave message protocol [4] in v2v and v2i communication [5][6] concept such as overtaking assistance system [3], forward collision warning and emergency electronic brake light (eebl). similar works to this research were the research conducted by [7][8], employing the same vehicle detection methods, however, different methods to estimate the distance between vehicle and camera were proposed in this research. the works are done by [8] estimated distance by means of using geometric relation yielded a quite good result of the accuracy of 90.29 % with claimed error average 9.71 %. the research done by [9] utilized a homography matrix and rodrigues identity to compute the * correspon ding author. tel: +62-81394486064 e-mail address: mulia.pratama@lipi.go.id https://dx.doi.org/10.14203/j.mev.2019.v10.7-16 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2019.v10.7-16 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2019.v10.7-16&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 8 rotation matrix, the distance between vehicle calculated from this rotation matrix, however, it used a different method to detect the vehicles with the one proposed in this research. this research mainly conducted on a card-sized computational resource namely raspberry pi 3 with a camera as image input; all vehicle detection, image processing and the computing of linear algebra done using the computer. haar cascade classifier used for vehicle detection as this method comparably the fastest to date. if a detection occurred, the algorithm sends the vehicle position and width annotated by the detection mechanism to the distance measurement algorithm which consists of several methods which will be compared for the performance namely the triangle similarity, solvepnp-iterative, and solvepnp-p3p with and without kalman filter. the useful data of longitudinal distance calculated, and visual images then are being sent via wifi to other vehicles or road-side unit. considering the adas roadmap and its development and v2x which include vanet, this research would contribute to improving people and road safety. the outcome of this research could increase driver awareness of the surrounding for example by adding alarm if cars or objects are within the proximity of a vehicle, also hopefully contribute to autonomous vehicle development. ii. materials and methods this section describes in detail of methods used in this research. mainly this section study about vehicle detection utilizing haar classifier and distance measurement methods. the workflow of the system under discussion described in the following figure 1. the camera captured an image frame to be analyzed for vehicular features indicating the frame consist of a vehicle image. if a vehicle confirmed then a bounding rectangle which approximates the width of the vehicle image is applied. either the width or the coordinates of the rectangle drawn would then be used to estimate the distance between vehicle and camera. distance information then sent via a wireless network to the other vehicles. the system developed was implemented in a raspberry pi 3 platform including the usage of its 8 mp raspberry pi camera. data and video were streamed via raspberry pi 3 embedded wifi trough named pipe fifo and netcat as a networking tool. the on-board wifi chip is the advantage of raspberry pi 3 compared previous raspberry pi releases that require extra usb wifi dongle, however, this research avoids the use of external usb wifi dongle since there are many wifi dongle manufacturers with their own characteristic in the market also some of them have an issue working with raspberry pi. moreover, they might need more power than a raspberry pi port can support. a. haar-cascade classifier there exist a fast and trainable method for object recognition, the haar cascade classifier [10] this method also used by [11] with the detector trained by bit-dataset and conclude that haar cascade classifier is a good candidate for object detector. research by [12] combines the haar detector with the k-nearest neighbour technique to identify the license plate of vehicles that claimed to offer great efficiency for practical use. according to [13], the classifier superior performance over image-intensity based algorithm encourages the use of haar cascade in this work. haar cascade adopted by [10] was a machine learning mechanism. the classifier evaluates the simple feature of an incoming image rather than processing the image by pixel. as can be seen in figure 2, image feature extraction involves haar features, a geometrical shape of a rectangle consisting figure 1. system flowchart m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 9 of a pair region of white and black. value of each image feature determined by the sum of the pixel under the white haar region deducted from the sum of the pixel under the black one. thus, the white rectangle weight 1 (one) and black region weight -1 (minus one). two-rectangle feature (a) [10] used to extract edge feature on image and three-rectangle feature (b) used to extract line feature on image. for example, figure 3 shows an applying haar basic feature shapes over an image of a vehicle. the pixels sum of the black and white are summed up (by subtraction) and the difference is the value of the image feature underlying the mask haar feature. to immediately evaluate the features and the author of [10] presented auxiliary integral image. any large number of features extracted, their values can be quickly calculated with only four points of reference. b. triangle similarity a simple spatial measurement based on geometrical properties of two similar triangles applied in this research referred to [14][15] and then be compared to other methods described later. fed by a known distance of a camera to a vehicle and a known width of the vehicle, one can obtain a focal length of the camera. as can be seen in figure 4, if df is the real width of the vehicle and ed is the real distance between camera to vehicle then one can find bd’ as the focal length of camera in pixel, provide that information of ac is available. information of ac length provided by the detection and tracking mechanism discussed previously and referred to as vehicle width in a pixel can be expressed using equation (1) 𝐷𝐹 (𝑚𝑒𝑡𝑒𝑟𝑠) 𝐸𝑑(𝑚𝑒𝑡𝑒𝑟𝑠) = 𝐴𝐶 (𝑝𝑖𝑥𝑒𝑙𝑠) 𝐵𝑑 ′ (𝑝𝑖𝑥𝑒𝑙𝑠) (1) by reversing (1), provided the focal length, real vehicle width in meters and perceived vehicle width in pixels, one can estimate the distance from the camera to the vehicle e-d. however, this is true if the vehicle positioned assumed exactly on the camera centerline. there are cases when vehicle position deviates from camera centerline a few meters and as result for this to happen is that the focal length bd’ of the camera needs to be reinitialized since the distance of the vehicle to the camera now is different for that particular position. research by [14] did not examine this problem as a contrast to [15] that decide not to recommend using triangle similarity if such a case happened. the reinitialize of focal length can be done by a camera calibration process either automatically or manually which is impossible to be carried out while vehicle running on the road. to maintain the parameter the same for the analysis, this method tested with the assumption above retained. c. iterative using levenberg-marquardt optimization the triangle similarity method previously described then will be compared with a perspective projection-based method. figure 5 describes a pinhole camera mechanism to better gain insight to understand the perspective-n-point (pnp). one can infer from figure 5, a model of a 3d box in universe reference characterized by its points q0 to qi is projected to a 2d image plane using perspective figure 2. haar feature shapes used to evaluate image features figure 3. haar feature used to detect rear windshield and rear tires of a vehicle that are distincive feature of a vehicle figure 4. two similar triangles m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 10 transformation. the model reconstructed in the image plane through a series of matrix operation involving rotation matrix refer to each axis and a translation matrix. rotation matrixes can be simplified into a single 3x3 matrix r 𝑅 = [ 𝑟11 𝑟21 𝑟31 𝑟12 𝑟22 𝑟32 𝑟13 𝑟23 𝑟33 ] (2) the vector of translation matrix t 𝑇 = [ 𝑡1 𝑡2 𝑡3 ] (3) also, consider a camera matrix one interested to obtain 𝑐𝑎𝑚𝑒𝑟𝑎 𝑚𝑎𝑡𝑟𝑖𝑥 = [ 𝑓𝑥 0 0 0 𝑓𝑦 0 𝑐𝑥 𝑐𝑦 1 ] (4) 𝑠 [ 𝑢 𝑣 1 ] = [ 𝑓𝑥 0 0 0 𝑓𝑦 0 𝑐𝑥 𝑐𝑦 1 ] [ 𝑟11 𝑟21 𝑟31 𝑟12 𝑟22 𝑟32 𝑟13 𝑡1 𝑟23 𝑡2 𝑟33 𝑡3 ] [ 𝑋 𝑌 𝑍 1 ] (5) a point of the model reconstructed in the image plane (u, v) by (2), (3) and (4) according to (5) that is the pinhole camera equation where: x, y, and z is the real coordinate of a point on a cube for example point qi. in universe of observer’s reference system. u and v is the coordinate of point qi in the observer’s image plane reference system. hence, qi is the perspective projection of point qi of the model. cx and cy are principal points usually at the image center. 𝑓𝑥 and 𝑓𝑦 is the focal length of the camera used. s is scaling factor. the aim here is to find the translation matrix t and retrieve its value as the distance between a vehicle and camera one interested. this research used the opencv library as computer vision tool to accomplish the computation. using opencv solvepnp with an iterative method it follows that the computer vision using levenbergmarquardt optimization to minimize the reprojection error that was the sum of the squared deviation between a point and its projection. d. the p3p problem opencv provides a way to solve the p3p problem according to [16]. in opencv, the function solvepnp can be used to estimate the pose of an object model that is to obtain the rotation matrix r and translation matrix t. flag solvepnp-p3p uses 3 object points for calculating the pose plus one additional point to provide the best result. the works by [16] present the complete solution classification for the perspective-three-points (p3p) that shown p3p has multiple solutions from an algebraic perspective under certain real conditions. to understand the problem in research [16], figure 6 provides a solution perspective where p, a, b, c are not-coplanar and p the center of perspective. moreover, 𝑎′ , 𝑏′ , and 𝑐 ′ are |cb|, |ac|, and |ab| respectively and α = ∠bpc, β = ∠apc, γ = ∠apb, p = 2 cos α, q = 2 cos β, r = 2 cos γ. it also notified that x, y, z are representing the distance from point p to the corresponding point. from triangle pac, pab and pbc, p3p equation can be written as (6) { 𝑌2 + 𝑍2 − 𝑌𝑍𝑝 − 𝑎′ 2 = 0 𝑍2 + 𝑋 2 − 𝑍𝑋𝑞 − 𝑏′ 2 = 0 𝑍2 + 𝑌2 − 𝑋𝑌𝑟 − 𝑐 ′ 2 = 0 (6) according to [16] a set of solutions exist for x, y, z that are the space from the camera to the object, if comply with some condition specified on their paper. figure 5. pinhole camera illustration m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 11 substituting 𝑋 = 𝑥𝑍, 𝑌 = 𝑦𝑍, 𝑐 ′ = √𝑣𝑍, 𝑎′ = √𝑎𝑣𝑍, 𝑏′ = √𝑏𝑣𝑍 to (6), divided by 𝑍 it become { 𝑦2 + 1 − 𝑦𝑝 − 𝑎𝑣 = 0 𝑥 2 + 1 − 𝑥𝑞 − 𝑏𝑣 = 0 𝑥 2 + 𝑦2 − 𝑥𝑦𝑟 − 𝑣 = 0 (7) thus 𝑣 = 𝑥 2 + 𝑦2 − 𝑥𝑦𝑟 > 2, 𝑍 can be obtained by 𝑍 = 𝑐 ′/√𝑣, this value was the first order approximation of vehicle distance one interested. moreover, one may find that by removing 𝑣 from (7) one my turn to a quadratic equation which yield a finite number of solutions if not at least four. e. kalman filter to smoothen thus hopefully improve the distance accuracy, kalman filter used with the help of noise characterizing to attain optimum kalman filter. the filter works based on a loop of measuring, predict and update. in order for the filter to work, a certain matrix should be provided: transition matrix f, measurement matrix h, q process noise matrix, r the measurement noise that is the noise characteristic that will be discussed in the next part of the paper. each measurement 𝑧 as a result of the detection process will be passed as matrix h. the filter then predict the next state of the system by �̅� = 𝐹𝑥 (8) 𝑃 = 𝐹𝑃𝐹𝑇 + 𝑄 (9) with �̅� is the next state of the system predicted; 𝑥 is the current (posteriori) state; 𝑃 predicted the state of covariance or error; and 𝑃 is the current state of covariance. then the filter updates the state of the system modified with the predicted state by the following equation 𝑥 = �̅� + 𝐾𝑦 (10) 𝑃 = (𝐼 − 𝐾𝐻)𝑃 (11) with 𝑧 is the measurement and 𝑦 is the residual defined as 𝑦 = 𝑧 − 𝐻�̅� (12) and 𝐾 as kalman gain 𝐾 = 𝑃𝐻𝑇(𝐻𝑃𝐻𝑇 + 𝑅)−1 (13) hereafter, the current state of the system 𝑥 is updated and the value can be used for the distance measurement algorithm. iii. results and discussions a. streaming latency the system was investigated for its performance in terms of latency, noise, and distance estimation accuracy. end-to-end latency mainly consists of 680x480 pixels video streaming latency and image processing which included the haar cascaded detection mechanism and distance estimation computation plus other additional negligible latency. the latency measurement for video streaming done on-line through with the help of an auxiliary camera and a digital stopwatch to count the whole measurement of the elapsed time. auxiliary camera used taken from front laptop camera, the setup is illustrated in figure 7. with this setup, both video previews from both cameras must be displayed adjacent to each other on the same display in a way so that when a print-screen button hit detected by the laptop, its screen displaying both measurements is saved to be analyzed. the real setup for measuring video-only stream can be seen in figure 8, it shows the area of the laptop monitor screen. figure 8 is displayed as it is captured from the laptop screen. both windows are inverted because each of these figure 6. illustration of p3p problem origin figure 7. latency measurement set up m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 12 windows shows two cameras reading of the same stopwatch displayed back on the laptop screen. the foremost display showed captured stopwatch image from local laptop camera and provided real measurement time counts about 21,780 milliseconds from start and served as offset basis to calculate endto-end latency, while the image behind it was the streamed stopwatch images from raspberry pi which provided the streaming delayed behind by 297 counts at 21,483 milliseconds, real-time counts assumed ideal with no delay; note that milliseconds counting marked by the oval making. it was obvious that the time counted for real-time showed larger counts than the streaming, indicating that the stopwatch image frame from raspberry pi was experienced 297 milliseconds delay during travel to the laptop display. table 1 reports the result of video streaming latency measurement included the delays for detection mechanism and distance measurement computation. the rightmost column was the end-toend latency calculated by (14) 𝐸𝑛𝑑 − 𝑡𝑜 − 𝐸𝑛𝑑 = 𝑟𝑒𝑎𝑙𝑡𝑖𝑚𝑒 𝑒𝑙𝑎𝑝𝑠𝑒𝑑 𝑡𝑖𝑚𝑒 − 𝑠𝑡𝑟𝑒𝑎𝑚𝑖𝑛𝑔 𝑒𝑙𝑎𝑝𝑠𝑒𝑑 𝑡𝑖𝑚𝑒 (14) the total end-to-end latency measured 1,490 milliseconds for using the triangle similarity method and 1,436 milliseconds for iterative levenbergmarquardt while p3p showed no improvement, the delay was very huge. the allowed latency for the inter-vehicular network should be less than 200 milliseconds referred to [3] and [17]. even for the aforementioned video-only streaming measured 297 milliseconds were out of the limit. an investigation for the source of such massive delay had been done by means of employing the time stamp function inserted in the program script. the time stamp was started to count just after the image captured and ended just after the distance computation finished and the image frame ready to be sent to the stream. table 2 showed the time consumed. from the table above can be seen that even the time needed to do the computing was about one-fourth of total end-to-end latency. from this experiment, it can be assumed that the source of the long delay was not the detection and computing process. the most logical suspect which caused the delay was the transmission path or the client unit that receive the video and data stream. for future research, the latency needs to be investigated whether it is device specific by means of comparing it to a more reliable computational resource such as pc equipped with good graphics processing unit. the usage of external usb wifi dongle also needs to be considered for future research if not using the dsrc/wave standards for v2x. b. noise characteristic noise performance is critical for both visual and accuracy since the addition of noise worsens the visualization of the vehicle being monitored as the rectangle marking spread randomly around the vehicle image thus alters the result of distance figure 8. real-time vs streamed latency measurement table 1. end-to-end latency measurement time e lapsed (in milliseconds) methods realtime streaming delta iterative levmarq 49:653 48:348 1,305 p3p 50:863 49:363 1,500 triangle similarity 55:524 54:034 1,490 video only 21:780 21:483 297 table 2. detection and distance computation latency in millisecon ds methods start end latency p3p 40:850 41:269 419 iterative levmarq 35:849 36:285 436 triangle similarity 22:379 22:797 418 m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 13 measurement as an error. figure 9 showed the fluctuation in vehicle identification, indicated by the dispersion of the bounding box around the vehicle image. the detection comes from the cascaded classifier was fluctuating in terms of vehicle position on the image at each measurement frame every half second. since the nature of the cascade classifier applied extensive numbers of haar feature by sizes and shapes [10] in sliding window, the results produced resembles a random process which generates a stationary white noise added to the measurement, this part intended to investigate the characteristic of the noise whether it is white or not and to see if optimum kalman filter can be exploited. white noise defined as a series of uncorrelated random variables following a continues distribution with zero mean and unity variance also a process is a white noise if its close-spaced time series sample is uncorrelated [18], moreover, if those samples were independent, it follows gaussian distribution hence guaranteed for randomness. the following figure 10 shows the fluctuation of 1000 measurement of for example 15 meters distance using the p3p method. one may effectively eliminate the noise online by employing optimal kalman filter. to this aim, one had to verify that the noise was white for the filter can be optimally utilized. as the figure below is shown, the zero mean and standard deviation of 0.904 are verified by the data. autocorrelation must be checked since it guarantees the randomness of the consecutive data generation. figure 11 was the autocorrelation under confidence level of 95 %. the figure showed that the data was uncorrelated since most of the lag autocorrelations fell between the limit of the shaded area. disregards lag 0, only one out of every 20 lags lie outside this limit, it was normal since it has a 95 % confidence level. the figure also showed that there were no patterned lags, for example a repeating lag position. another method to verify the noise is by mean of the anderson-darling distribution test [19], the data were tested against the normal distribution. the anderson-darling test return test statistic a2 to be compared to a critical value of 0.576, 0.656, 0.787, 0.918 and 1.092 for significant level 10 %, 5 %, 2.5 %, 1 % and 0.5 % respectively. if the test returns a2 value greater than the value mentioned above it then the test sample not likely produced from a normal distribution. fed the measurement data to the test procedure, it returns a2 value of 0.574, 0.653, 0.784, 0.914, and 1.088 respecting the same significant level indicating that the measurement data have normal (gaussian) distribution. by those facts, it is concluded that the fluctuation generates a white gaussian noise. with the noise characterized, the kalman filter can be optimally employed to the measurement with the assumption that the simulated process noise was also white and uncorrelated to the noise being figure 10. noise from measuremet of 15 meters using p3p method with mean value subtracted -3 -2 -1 0 1 2 3 4 5 -100 100 300 500 700 900 1100 m e te rs frames figure 9. noisy vehicle markings m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 14 discussed. with the unfiltered average signal of 15.48 meters and the noise rms of 0.900 meters, one may find the signal to noise ratio (snr) is 54.40 db respect to the following formula (15) 𝑆𝑁𝑅 = 20 × 𝐿𝑜𝑔 ( 𝑆𝑖𝑔𝑛𝑎𝑙 √𝑁𝑜𝑖𝑠𝑒 2̅̅ ̅̅ ̅̅ ̅̅ ̅̅ √𝑁) (15) hopefully, kalman filter reduces the noise up to an order of magnitude. the result of filtering shows the noise reduction, figure 12 showed the fluctuation after filtering. the noise rms improves to 0.34 meters but the signal average increase 15.51 meters thus improves snr to 62.87 db less than the expected, however, this adds offset error to the true 15 meters up to 0.51 meters from 0.48 meters unfiltered originally. kalman filtering improves the visualization but worsens the accuracy to 3 cm for measurement of 15 meters distance. however, this assumption will be verified by investigating the observed behavior in other methods. c. performance of distance estimation the system was tested in 5 to 20 meters involving three methods for distance estimation. these methods are discussed in this part were the triangle similarity, iterative with lavenberg-marquardt optimization and p3p, last two adopted from camera imaging and homography technique. the experiment applied on one type of vehicle to maintain the uniformity of parameters so it was easier to be analyzed for example the camera matrix that contains focal length calibrated using the most common city car width about 1.64 meters. moreover, measuring with various kinds of vehicles avoided because it will guide to the further comparative analysis of the performance of the haar cascade classifier such as true positive rate (tpr) which is not the scope of this paper. the dataset for training the classifier used here is not standard datasets such as bit-dataset, kitty or epfl. all methods will be compared for its performance in terms of accuracy for a filtered and figure 11. autocorrelation from measurement data for 15 meters using p3p method figure 12. noise from measurement of 15 meters using p3p method after filtering -1 -1 0 1 1 2 -100 100 300 500 700 900 1100 m e te rs frames m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 15 unfiltered result for about 1000 samples averaged. the setup was a parking area with markings every two meters. a car was set in a position while raspberry pi and the camera placed in a distance of 5, 10, 15, and 20 meters from the rear end of the car. light intensity not recorded thus to maintain the same ambient and environment condition the camera also records a video while measuring, the video will be used to test the other methods. table 3 present the averaged result for unfiltered 5 and 10 meters; the table also provides the standard deviation from the measurement placed inside the parentheses next to the averaged values. from the table, we can infer that the smallest offset error to 5 and 10 meters attained by the iterative levenbergmarquardt method with an error less than 1 meter to the true value while p3p contributes to the biggest offset, 1.78 meters and 2.63 meters for 5 and 10 m respectively. the performance gets more complicated when referring to table 3 for 15 and 20 meters since the smallest offset error achieved by triangle similarity and p3p methods, they are 0.39 meters and 0.71 meters respectively retain the offset down below 1 meter respecting the ground truth value. the largest offset error now held by iterative with levenbergmarquardt iteration yields 1.72 meters and 3.16 meters respectively for 15 and 20 meters. as for the standard deviation, they will be compared with the filtered measurement and be examined for any improvements. passing the measurements to a kalman filter, table 4 resumes the observation. comparing to the previous table, the difference between unfiltered and filtered result is not significant, the biggest come from 5 meters of p3p, and it differs up to 30 centimeters. from this experiment employing iterative with lavenberg-marquardt and kalman filtering was the best practice with accuracy 84.2 %, the error rate was 15.8 % for 5 meters distance and for 10 meters the accuracy was 91.2 %. meanwhile, for 15 and 20 meters, the p3p method was reliable enough with accuracy 96.9 % and an error rate of 3.1 % at best. respectively compared to the unfiltered measurement, for 5 and 10 meters the maximum accuracy was 92.3 % produce error rate 7.7 % while for 15and 20-meters maximum accuracy was 96.8 % with error rate 3.2 %. the filtering effect also can be seen especially for measuring 15 and 20 meters; the standard deviation reduced to about 40 % to 60 % of the initial unfiltered measurement. iv. conclusion to embody the research to a working experiment, a system was built incorporated raspberry pi 3 as its main computational platform. using the system, there are two main mechanisms discussed in this paper: video streaming latency and distance estimation accuracy. video streaming was able to be executed by the system but the latency was very huge up to 1500 milliseconds in which more than onefourth of it was the process latency but vanet required less than 200 milliseconds for vehicular video streaming thus in term of latency the system built was not satisfied, the biggest delay was caused by the transmission or the client for the first approximation, required further research on this field. suggestion for future research is to use wifi dongle with external power supply or with more advanced topics, the adoption of dsrc/wave chip v2x standard instead of ordinary wifi. distance estimation highly dependent on the result of the vehicle detection mechanism mainly its fluctuation, to address that matter kalman filter employed to filter the noise; unfortunately, it added offset error to the real measurement up to 30 centimeters at 5 meters. moreover, in terms of accuracy the system built has good accuracy rated at 96.9 % for measuring 20 meters incorporating solve pnp-p3p method. acknowledgment the authors would like to express the deepest appreciation to all those who provided a suggestion, comment, advice, and assistance on the completion of this research. special gratitude would be given to mr. ahmad dimyani, who’s contributed to substantial suggestions and also coordinate the completion of the project. furthermore, the authors would also like to acknowledge the role of the staff of telimek ice laboratory, who assists in the use of all required table 3. measurement results without filtering grou nd truth itera tive levmarq (std. dev) p3p (std.dev) triang le similarity (std. dev) 5 5.80 (0.17) 6.78 (0.55) 6.24 (0.18) 10 10.77 (0.50) 12.63 (0.53) 11.80 (0.54) 15 13.28 (0.89) 15.48 (0.81) 14.61 (0.94) 20 16.84 (1.03) 19.29 (1.07) 18.55 (1.11) table 4. measurement results filtered grou nd truth itera tive levmarq (std. dev) p3p (std. dev) triang le similarity (std. dev) 5 5.79 (0.13) 7.14 (0.14) 6.23 (0.14) 10 10.88 (0.32) 12.70 (0.39) 11.79 (0.39) 15 13.31 (0.37) 15.51 (0.35) 14.53 (0.36) 20 16.92 (0.61) 19.38 (0.63) 18.48 (0.64) m. pratama et al. / journal of mechatronics, electrical power, an d vehicular technology 10 (2019) 7–16 16 equipment, the provision on the necessary materials, and also on the complete sampling images collection. special gratitude was presented to mr. amin and mr. kristian ismail, who helped the authors on assembling the whole prototype and apprehending the task of filtering measurement. declarations author contribution m. pratama and w.b. santoso contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not -for-profit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] m. mittal, “a study of live video streamin g over highway vehicular ad hoc networks,” int. j. comput. appl., vol. 1, no. 21, pp. 86–90, feb. 2010. [2] c. iza-paredes, a . m. mezher, an d m. a guilar igartua, “adaptive video-streaming dissemination in realistic highway vehicular ad-hoc networks,” in proceedings of the 13th acm symposium on performance evaluation of wireless ad hoc, sensor, & ubiquitous networks pe-wasun ’16, 2016, pp. 1–10. [3] a. vinel, e. belyaev, k. egiazarian , and y. koucheryavy, “an overtaking assistance system based on joint beaconing and real-time video transmission,” ieee trans. veh. technol., vol. 61, no. 5, pp. 2319–2329, 2012. [4] b. cronin, “vehicle based data and availability,” u.s. department of transportation, 2016. [5] u. d. gan dhi, a. singh, a. mukherjee, and a. chan dak, “smart vehicle connectivity for safety application s,” in 2014 international conference on reliability optimization and information technology (icroit), 2014, pp. 262–266. [6] c. b. math , h. li, and s. heemstra de groot, “risk assessment for traffic safety applications with v2v communications,” in 2016 ieee 84th vehicular technology conference (vtc-fall), 2016, pp. 1–6. [7] n. f. mustamin, “relative distance measurement between moving vehicles for manless driving,” in 2017 international seminar on application for technology of in formation and communication (isemantic) , 2017, pp. 1–4. [8] a. a. ali and h. a. hussein, “distance estimation and vehicle position detection based on monocular camera,” in 2016 alsadeq international conference on multidisciplinary in it and communication science and a pplications (aic-mitcsa), 2016, pp. 1–4. [9] h.-k. cheung, w.-c. siu, s. lee, l. poon, and chiu-shing ng, “accurate distance estimation using camera orientation compen sation technique for vehicle driver assistance system,” in 2012 ieee international conference on consumer electronics (icce), 2012, pp. 227–228. [10] s. jabri, m. saidallah, a. el belrhiti el alaoui, and a. el fergougui, “movin g vehicle detection using haar-like, lbp and a machine learning adaboost algorithm,” in 2018 ieee international conference on image processin g, a pplication s and systems (ipas), 2018, pp. 121–124. [11] e. baser and y. altun, “detection and classification of vehicles in traffic by using haar cascade classifier,” proc. 58th iserd int. conf. sci. innov. eng., no. december, pp. 19–22, 2016. [12] m. rokonuzzaman , m. a. al amin, m. h. k. m. u. ahmed, an d m. t. rahman, “automatic vehicle identification system using machine learning and robot operating system (ros),” in 2017 4th international conference on advances in electrical engineering (icaee), 2017, pp. 253–258. [13] y. hasan, m. u. arif, a . asif, an d r. h. raza, “comparative analysis of vehicle detection in urban traffic environment using haar cascaded classifiers and blob statistics,” in 2016 future technologies conference (ftc) , 2016, pp. 547–552. [14] g. kim and j.-s. cho, “vision-based vehicle detection and intervehicle distance estimation for driver alarm system,” opt. rev., vol. 19, no. 6, pp. 388–393, nov. 2012. [15] r. k. megalingam, v. shriram, b. likhith, g. rajesh , and s. ghanta, “monocular distance estimation usin g pinhole camera approximation to avoid vehicle crash and back-over accidents,” in 2016 10th international conference on intelligent systems and control (isco), 2016, pp. 1–5. [16] x. ying, g. wang, x. mei, s. yang, an d h. zha, “the perspective3-point problem when using a planar mirror,” proc. int. conf. pattern recognit., pp. 4033–4037, 2014. [17] b. bellalta, e. belyaev, m. jon sson , and a. vinel, “performance evaluation of ieee 802.11p-enabled vehicular video surveillance system,” ieee commun . lett., vol. 18, no. 4, pp. 708–711, apr. 2014. [18] r. m. howard, “white noise: a time domain basis,” 2015 int. conf. noise fluctuation s, icnf 2015, pp. 1–4, 2015. [19] p. closas, j. arribas, and c. fern, “testing for normality of uwbbased distance measurements by the anderson-darling statistic,” futur. netw. mob. summit 2010 conf. proc., pp. 1–8, 2010. https://doi.org/10.5120/46-643 https://doi.org/10.5120/46-643 https://doi.org/10.5120/46-643 https://doi.org/10.1145/2989293.2989301 https://doi.org/10.1145/2989293.2989301 https://doi.org/10.1145/2989293.2989301 https://doi.org/10.1145/2989293.2989301 https://doi.org/10.1145/2989293.2989301 https://doi.org/10.1109/tvt.2012.2192301 https://doi.org/10.1109/tvt.2012.2192301 https://doi.org/10.1109/tvt.2012.2192301 https://doi.org/10.1109/tvt.2012.2192301 https://www.its.dot.gov/itspac/october2012/pdf/data_availability.pdf https://www.its.dot.gov/itspac/october2012/pdf/data_availability.pdf https://doi.org/10.1109/icroit.2014.6798327 https://doi.org/10.1109/icroit.2014.6798327 https://doi.org/10.1109/icroit.2014.6798327 https://doi.org/10.1109/icroit.2014.6798327 https://doi.org/10.1109/vtcfall.2016.7881202 https://doi.org/10.1109/vtcfall.2016.7881202 https://doi.org/10.1109/vtcfall.2016.7881202 https://doi.org/10.1109/vtcfall.2016.7881202 https://doi.org/10.1109/isemantic.2017.8251840 https://doi.org/10.1109/isemantic.2017.8251840 https://doi.org/10.1109/isemantic.2017.8251840 https://doi.org/10.1109/isemantic.2017.8251840 https://doi.org/10.1109/aic-mitcsa.2016.7759904 https://doi.org/10.1109/aic-mitcsa.2016.7759904 https://doi.org/10.1109/aic-mitcsa.2016.7759904 https://doi.org/10.1109/aic-mitcsa.2016.7759904 https://doi.org/10.1109/aic-mitcsa.2016.7759904 https://doi.org/10.1109/icce.2012.6161840 https://doi.org/10.1109/icce.2012.6161840 https://doi.org/10.1109/icce.2012.6161840 https://doi.org/10.1109/icce.2012.6161840 https://doi.org/10.1109/icce.2012.6161840 https://doi.org/10.1109/ipas.2018.8708898 https://doi.org/10.1109/ipas.2018.8708898 https://doi.org/10.1109/ipas.2018.8708898 https://doi.org/10.1109/ipas.2018.8708898 https://doi.org/10.1109/ipas.2018.8708898 http://www.worldresearchlibrary.org/up_proc/pdf/578-148663411819-22.pdf http://www.worldresearchlibrary.org/up_proc/pdf/578-148663411819-22.pdf http://www.worldresearchlibrary.org/up_proc/pdf/578-148663411819-22.pdf https://doi.org/10.1109/icaee.2017.8255362 https://doi.org/10.1109/icaee.2017.8255362 https://doi.org/10.1109/icaee.2017.8255362 https://doi.org/10.1109/icaee.2017.8255362 https://doi.org/10.1109/icaee.2017.8255362 https://doi.org/10.1109/ftc.2016.7821660 https://doi.org/10.1109/ftc.2016.7821660 https://doi.org/10.1109/ftc.2016.7821660 https://doi.org/10.1109/ftc.2016.7821660 https://doi.org/10.1007/s10043-012-0063-1 https://doi.org/10.1007/s10043-012-0063-1 https://doi.org/10.1007/s10043-012-0063-1 https://doi.org/10.1109/isco.2016.7727017 https://doi.org/10.1109/isco.2016.7727017 https://doi.org/10.1109/isco.2016.7727017 https://doi.org/10.1109/isco.2016.7727017 https://doi.org/10.1109/isco.2016.7727017 https://doi.org/10.1109/icpr.2014.691 https://doi.org/10.1109/icpr.2014.691 https://doi.org/10.1109/icpr.2014.691 https://doi.org/10.1109/lcomm.2014.022514.140206 https://doi.org/10.1109/lcomm.2014.022514.140206 https://doi.org/10.1109/lcomm.2014.022514.140206 https://doi.org/10.1109/lcomm.2014.022514.140206 https://doi.org/10.1109/icnf.2015.7288581 https://doi.org/10.1109/icnf.2015.7288581 https://ieeexplore.ieee.org/document/5722412 https://ieeexplore.ieee.org/document/5722412 https://ieeexplore.ieee.org/document/5722412 https://ieeexplore.ieee.org/document/5722412 mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.57-67 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia control of mobile robot formations using a-star algorithm and artificial potential fields nelson luis manuel *, nihat i̇nanç, mustafa yasin erten department of electrical & electronics engineering, kırıkkale university kırıkkale city, 71450, turkey received 22 november 2021; accepted 16 december 2021; published online 31 december 2021 abstract formations or groups of robots become essential in cases where a single robot is insufficient to satisfy a given task. with an increasingly automated world, studies on various topics related to robotics have been carried out in both the industrial and academic arenas. in this paper, the control of the formation of differential mobile robots based on the leader-follower approach is presented. the leader's movement is based on the least cost path obtained by the a-star algorithm, thus ensuring a safe and shortest possible route for the leader. follower robots track the leader's position in real time. based on this information and the desired distance and angle values, the leader robot is followed. to ensure that the followers do not collide with each other and with the obstacles in the environment, a controller based on artificial potential fields is designed. stability analysis using lyapunov theory is performed on the linearized model of the system. to verify the implemented technique, a simulator was designed using the matlab programming language. seven experiments are conducted under different conditions to show the performance of the approach. the distance and orientation errors are less than 0.1 meters and 0.1 radians, respectively. overall, mobile robots are able to reach the goal position and maintaining the desired formation in finite time. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: nonholonomic wmr; leader-follower approach; formation control; a-star algorithm; artificial potential fields. i. introduction the formation of robots is an imitation of a group of behaviors observed in various creatures in the biological world that tend to work cooperatively in order to achieve a common goal [1]. while most industrial robots can only perform specific movements in the workspace, mobile robots can move freely within the predefined workspace [2]. this feature (mobility) expands the possibilities for the application of mobile robots in different environments [3][4][5]. there are certain circumstances in which, due to the complexity of the task, a single robot may not be able to satisfy several tasks simultaneously and/or efficiently. to overcome this, the formation of these robots can be considered [2]. several advantages are pointed out with the implementation of robotic formations, such as better precision, increased efficiency and robustness against external agents [2]. the methods of controlling the formation of mobile robots can be divided into three classes: behavioral approach, virtual structure approach, and leader-follower approach [6][7]. in the leader-follower approach, one of the robots plays the role of leader and the rest are followers. the idea behind this approach is that the followers adjust their states according to the position of the leader robot. there are different leader-follower topologies, for example, approaches that consider multi-leaders, forming a chain (vehicle tracks vehicle), among others [2]. it is possible to find different control techniques for leader-follower robotic formations in the literature. fuzzy logic controller is presented for the formation of wheeled mobile robots (wmrs) [8]. input-output (i/o) feedback linearization along with potential fields is used to control the formation of robots in the leader-follower approach [9]. linear model predictive control (mpc) along with feedback linearization is applied to achieve the task of a formation of wmrs [10]. a non-linear mpc based on neurodynamic-optimization is presented to control the formation of wmrs in a leader-follower architecture [11][12]. a control strategy based on lyapunov theory and sliding mode is applied to * corresponding author. tel: +90-552-5824071 e-mail address: nelsonluismanuel@gmail.com https://dx.doi.org/10.14203/j.mev.2021.v12.57-67 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.57-67 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.57-67&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 58 multiple wmrs in a leader-follower structure [13]. the leader-follower approach has advantages such as simplicity, no need for global knowledge, and consequently, reduced computerization cost [13]. in this paper, a technique for controlling differential mobile robot formations based on the astar and artificial potential fields algorithms is presented. the approach used is leader-follower, where the leader receives information about the safest and lowest cost route in an environment with the presence of obstacles from the a-star algorithm. the leader's position and orientation are constantly monitored by the followers. using a controller based on artificial potential fields, the leader's trajectory is followed, maintaining the desired separation and orientation while avoiding collisions with each other and the obstacles present in the environment. ii. materials and methods a. kinematic model of differential mobile robot with the exception of a few, most control techniques depend on the mathematical model of the system to be controlled. therefore, the first step before deducing the control laws is to define the mathematical model of the differential mobile robot. from figure 1, applying some trigonometry concepts, the system of equations (1) can be determined. cos( ) 0 sin( ) 0 0 1 i x v y θ θ ω θ         =                 (1) here 𝑣 is the linear velocity, 𝜔 is the angular velocity, �̇� is the velocity with respect to the x-axis, �̇� is the velocity with respect to the y-axis, and �̇� is the bearing angle. a differential drive wheeled mobile robot is usually composed of two independently controlled wheels and an additional wheel (or caster) for balance purposes. the direction of movement, speed, and orientation of the robot is defined by the speed ratios between its wheels [14]. figure 1 is a schematic of a differential drive wheeled mobile robot in an inertial frame, where 𝑋𝐼 and 𝑌𝐼 represent the inertial (or global) frame axes and 𝑋𝑅 and 𝑌𝑅 represent the robot frame (or local frame) axes. the robot's linear velocity 𝑣(𝑡) is always parallel to the 𝑋𝑅 axis of the robot frame due to the nonholonomic constraint. the robot's orientation is measured between the 𝑋𝐼 and 𝑋𝑅 axes. the change in orientation 𝜃(𝑡) of the robot represents the angular speed 𝜔(𝑡). the robot's equivalent position on the inertial frame is shown by the point p. system (1) represents the mathematical model of the differential mobile robot shown in figure 1. in general terms, it can be said that to design a controller for this mobile robot system, it is necessary to find the law that provides the relationship between the output vector (the robot position) and the input vector of the system (linear and angular velocities). such a relationship can be considered as a transformation matrix. the purpose of the controller layout is to find, if it exists, a 2×3 control matrix 𝐾, as shown in equation (2) [15]. 11 12 12 21 22 23 , ( , )ij k k k k k k t e k k k   = =    (2) because of the non-linearity of the robot model, the elements (𝑘𝑖𝑖) of the control matrix (𝐾) are timevarying and error dependent, as expressed in equation (2). the matrix 𝐾 has to be able to generate control signals 𝑣(𝑡) and 𝜔(𝑡) in such a fashion that the error 𝑒(𝑡) tends to zero as time 𝑡 tends to infinity, i.e., equation (3) has to be satisfied. ( ) . , lim ( ) 0 ( ) r t x v t k e k y e t tω θ →∞      = = =         (3) finding the matrix 𝐾 in (2) is not that simple as it depends on the current value of the error and its elements can change over time. to overcome this, the approach used in [15] will be considered. a schematic of a robot and a desired position (or goal) is illustrated in figure 2. the frame of the desired position (𝑋𝐺, 𝑌𝐺) is set to match the inertial frame (𝑋𝐼, 𝑌𝐼) . the euclian distance between the robot and the desired position is symbolized by 𝜌; ∆𝑥 and ∆𝑦 are the differences between the 𝑥 and 𝑦 coordinates of the robot's position and the desired position, respectively. the bearing angle which orients the robot towards the goal position is 𝑿𝑰 𝒀𝑰 𝜔(𝑡) 𝑣(𝑡) 𝜃 castor wheel 𝒀𝑹 𝑿𝑹 p figure 1. differential drive mobile robot in an inertial frame 𝜔 𝑣 𝜃𝑅 𝛼 𝜌 δ𝑥 δ𝑦 yr y𝐺 = 𝑌𝐼 x𝐺 = 𝑋𝐼 xr 𝛽 𝜃𝐺 𝛾 goal robot figure 2. kinematics of differential mobile robot n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 59 indicated by the angle 𝛼. the difference between the desired orientation (𝜃𝐺) and the robot orientation (𝜃𝑅), when 𝛼 = 0 is represented by the angle 𝛽. from figure 2, the following closed-loop parameters can be determined: 2 2 r g x yρ α θ γ β θ γ = ∆ + ∆ = − + = − (4) where 𝛾 = 𝑎𝑡𝑎𝑎2(δ𝑦, δ𝑥), as can be clearly concluded from figure 2. unlike the arctangent (atan) function, arctangent2 (atan2) function operates in all four quadrants [16]. since the robot has orientations in all quadrants, the atan2 function is preferred over atan, which only returns results in two quadrants. to analyze the behavior of the parameters (𝜌, 𝛼, 𝛽) presented in equation (4) as time passes, their time derivatives are computed. since these parameters are not directly expressed as functions of time, their derivatives are obtained through the chain rule. therefore, the dynamics of the euclidean distance ( 𝜌 ), applying the chain rule, can be expressed as in equation (5). r r r r r r dx dy dd d d d dt dx dt dy dt d dt θρ ρ ρ ρ ρ θ = = + + (5) the �̇� on the left side of equation (5) represents the time derivative of the euclidean distance (𝜌), and the addends on the right side are the partial derivatives of 𝜌 with respect to 𝑥 , 𝑦 , and 𝜃 , respectively. in equations (6), (7), and (8), the derivatives of the addends present on the right side of equation (5) are demonstrated. ( ) ( )2 2 ;g r r g r g r r r x xd x dx x x y y dx x dt ρ ρ − ∆ = − = − − + − =  (6) ( ) ( )2 2 ;g r r g r g r r r y yd y dy x x y y dy y dt ρ ρ − ∆ = − = − − + − =  (7) 0 ; dd r rd dtr θρ θ θ = =  (8) where 𝑥𝑅 , 𝑦𝑅 represent the robot position coordinates on the 𝑋𝐼 and 𝑌𝐼 axes and 𝑥𝐺, 𝑦𝐺 are the goal position coordinates on the 𝑋𝐼 and 𝑌𝐼 axes of the inertial frame. substituting the results obtained in equations (6), (7), and (8) in equation (5), the equation (9) is derived. . .r rx x y yρ ρ ∆ + ∆ = −    (9) furthermore, replacing 𝛥𝑥 by 𝜌cos (𝛾) , δy by 𝜌sin (𝛾) , 𝑥�̇� by 𝑣cos (𝜃) , 𝑦�̇� by 𝑣sin (𝜃) , and then applying the trigonometric identity cos(𝑎 − 𝑏) = cos(𝑎) . cos(𝑏) + sin(𝑎) . sin(𝑏), equation (9) becomes equation (10), which represents the rate of change of the euclidean distance (𝜌) with respect to time. cos( )vρ α= − (10) applying the same idea used to obtain the equation (10) to the other two parameters presented in equation (4), the system (11) can be derived. cos( ) 0 sin( ) 1 sin( ) 0 v α ρ α α ωρ β α ρ    −        = −            −       (11) b. stability analysis using lyapunov the feedback system given in (11), presents a discontinuity at 𝜌 = 0. to solve this, the inputs (𝑣 and 𝜔) are selected as shown in the system (12). cos( ) ( ) sin( ) sin( ) k v x k k k k ρ ρ α β ρ ρ ρ α α α α β β α  −    = = − −      −        (12) where 𝑉(𝑥) is the lyapunov function applied to the differential mobile robot model, 𝑘𝜌 is the linear velocity adjustment gain, 𝑘𝛼 and 𝑘𝛽 are the robot orientation adjustment gains. the system (12) is now continuous at the point [𝜌, 𝛼, 𝛽] = [0, 0, 0], which is the point of interest (the goal). however, as this system is not linear, the stability analysis becomes complex. to facilitate this, the analysis is carried out at the equilibrium point of interest. local stability analysis allows the approximation of the behavior of a non-linear system to an equivalent linear system at the point of interest. applying jacobian to the system (12) in the goal position ( [𝜌, 𝛼, 𝛽] = [0, 0, 0]) , system (13) is derived. the matrix a of the system (13) is linear and time-invariant, therefore, the stability analysis becomes simplified. a 0 0 0 ( ) 0 0 k k k k k ρ α ρ β ρ ρ ρ α α β β  −        = − − −         −        (((((((( (13) the system is locally exponentially stable, if all eigenvalues of the matrix a presented in (13) have a negative real part. from the matrix a the characteristic polynomial presented in equation (14) is obtained. ( ) 2 ( )k k k k kρ α ρ ρ βλ λ λ + + − −  (14) the 𝜆 in equation (14) represents the eigenvalues of matrix a. therefore, in order for the system to be stable after reaching the destination, the conditions presented in (15) must be met. 0; 0;k k k kρ β α ρ> < > (15) n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 60 c. a-star algorithm a-star, is one of the widely applied computer science algorithms, which takes some inputs (the starting sector and the destination sector), calculates the costs of different possible routes and returns the path with the lowest cost between the starting sector and the destination sector [17]. a-star is based on equation (16): ( ) ( ) ( )f x g x h x= + (16) where 𝑥 is a sector on the map, 𝑔(𝑥) is the total distance from the starting sector to the current sector 𝑥 , ℎ(𝑥) is the heuristic function used to calculate the distance from the current position to the desired position, and 𝐹(𝑥) is the cost function. figure 3 is a flowchart that gives a brief explanation of how the applied a-star algorithm works. d. artificial potential fields in artificial potential fields (apf), objects in the workspace are modeled as potential fields that generate forces of attraction and repulsion [18]. target points are modeled to generate attraction forces, while obstacles are modeled as points that generate repulsion forces to the robot [19]. in this manner, the robot tends to move towards the target while avoiding obstacles present in the environment. the function of the attractive potential field can be expressed by equation (17). ( )21(x ) 2att r att r d u k x x= − (17) where 𝑈𝑎𝑎𝑎(𝑋𝑅) represents the attractive potential field function, 𝐾𝑎𝑎𝑎 is a positive constant (defines the influence of the attractive field), 𝑋𝑅 is the vector of the robot's position and 𝑋𝐷 is the vector of the desired (or goal) position. the negative gradient of the attractive potential field function results in the corresponding attractive force, as shown in equation (18). ( ) ( )att att att d r d r att d r f u k x x x x k y y = −∇ = − −  =  −  (18) where 𝑥𝐷 and 𝑦𝐷 are the desired position ( 𝑋𝐷) components and 𝑥𝑅 and 𝑦𝑅 are the robot position (𝑋𝑅) components. similarly, the repulsive potential field function is defined according to equation (19). 2 1 1 1 , ( ) 2 0 , rep o rep r o o k u x e e e e e e     − ≤ =     > (19) where 𝑈𝑟𝑟𝑟(𝑋𝑅) is the repulsive potential field start specify starting, ending and obstacles positions compute cost function (using e q. 16). is open list null? select the node (x) with the lowest f(x) as start node. save its index and place it in the closed list no feasible path not found yes end is (x) the goal point? yes a no a expand the current node (x) and create a new node (x) which is not on the closed list is the new node already in the open list? compare the new g(x) and the old g(x) of the new node (x) and update g(x) to the smaller one yes place the new node (x) into the open list no b b use saved index pointers to get the shortest path. send this path to the leader robot create an open list and a closed list; place the start node and its adjacents in the open list; put obstacles in the closed list figure 3. flowchart of a-star algorithm n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 61 function, 𝐾𝑟𝑟𝑟 is a positive parameter which defines the impact of the repulsive potential, 𝜀 is the distance between the robot and the obstacle and 𝜀0 represents the threshold distance of the repulsive potencial field influence. the repulsive force ( 𝐹𝑟𝑟𝑟 ) is determined by computing the negative gradient of the repulsive field, as shown in equation (20). ( ) 3 1 1 , 0 , rep rep rep o r o o ro o f u k x x y y e e e ee e e = −∇  −   − ≤   −=      > (20) where 𝑥𝑜 and 𝑦𝑜 are the components of the obstacle vector. therefore, the resulting total force (𝐹𝑎𝑜𝑎) that moves the robot towards the desired position will have the influences of both attractive and repulsive forces as expressed in equation (21). figure 4 is a simplified representation of the resulting force on the follower robot in the presence of the attractive field (which pulls the robot towards the leader) and the repulsive field (which arises due to the presence of obstacles). ( ) ( ) (x )tot r att r rep rf x f x f= + (21) in algorithm 1, the pseudocode of the controller applied in this paper based on artificial potential fields is presented. algorithm 1: pseudocode of the apf input: leader’s position, followers’ positions, desired position(s), stopping criterion (𝛿), max. linear and angular speeds (𝑣𝑚𝑎𝑥 and 𝜔𝑚𝑎𝑥 ). output: linear and angular speeds (𝑣 and 𝜔). 1: while (𝜌 > 𝛿) do 2: 𝑥𝑅, 𝑦𝑅, 𝜃𝑅 ←sense the robot position; 3: 𝐹𝑎𝑡𝑡 = 𝐾𝑎𝑡𝑡 � 𝑥𝐷 − 𝑥𝑅 𝑦𝐷 − 𝑦𝑅 �; 4: 𝐹𝑟𝑒𝑟 = � 0 0 �; 5: 𝑁𝑜 ← sense the obstacle(s); 6: if 𝑁𝑜 > 0 then 7: 𝐹𝑟𝑒𝑟 = 𝐾𝑟𝑒𝑟 ∑ 1 𝜖𝑖 3 � 1 𝜖0 − 1 𝜖𝑖 �� 𝑥𝑜𝑖 − 𝑥𝑅 𝑦𝑜𝑖 − 𝑦𝑅 �𝑁0𝑖=1 ; 8: end 9: 𝐹𝑡𝑜𝑡 = 𝐹𝑎𝑡𝑡 + 𝐹𝑟𝑒𝑟 ; 10: 𝑣 ← 𝑚𝑖𝑎(‖𝐹𝑡𝑜𝑡‖2 , 𝑣𝑚𝑎𝑥 ); 11: 𝜔 ← �𝑎𝑡𝑎𝑎2�𝐹𝑡𝑜𝑡 {𝑦}, 𝐹𝑡𝑜𝑡 {𝑥}� − 𝜃𝑅�; 12: 𝜔 ← 𝑠𝑖𝑔𝑎(𝜔)𝑚𝑖𝑎(|𝜔|, 𝜔𝑚𝑎𝑥 ); 13: 𝜌 ← �(𝑥𝐷 − 𝑥𝑅)2 + (𝑦𝐷 − 𝑦𝑅)2 ; 14: return 𝑣 and 𝜔; 15: end iii. results and discussions to demonstrate that the designed controllers work properly, a simulator was designed using the matlab programming language. the simulations were carried out using matlab r2019a software, installed in a personal computer equipped with an intel® core™ i3 2.20 ghz processor and 4.00 gb of ram. the a-star algorithm is used to obtain the least cost path. this path is sent to the leader. the leader's position is communicated to the followers. based on this information and according to the values of the desired distances and angles, the followers track the leader robot. followers are controlled based on the artificial potential fields algorithm, thus avoiding obstacles in real time. as shown in the next subsections, seven experiments were conducted under different conditions. in all experiments, the leader is colored red, and the followers are colored yellow. the robots' positions are represented by a 1×3 vector, that is, [𝑥 (𝑚), 𝑦 (𝑚), 𝜃(𝑟𝑎𝑟)], while the obstacles are represented by a 1× 2 vector, i.e., [𝑥 (𝑚), 𝑦 (𝑚)]. a. first experiment one follower and one leader are used for this experiment. a vertical obstacle is placed in the environment. the leader robot is asked to follow the safe route obtained by a-star. the follower robot is asked to keep an angle of 0 radians and a distance of 1 meter from the leader. the starting positions of leader and follower are [2.50, 6.50, -0.524], and [2.00, 8.50, 0.175], respectively. the goal position is [10.5, 6.5, 0.873], while the positions of the obstacles are [6.5, 5.5], [6.5, 6.5], and [6.5, 7.5]. the leader’s final position is [10.44, 6.43, 0.877] and the follower’s final position is [9.73, 5.60, 0.858]. the trajectories of this experiment, which lasted 122.623 seconds to complete, are illustrated in figure 5. b. second experiment in this experiment, one leader and one follower are taken again. but this time, a horizontal obstacle was placed in the environment. under these conditions, the leader is asked to reach the target point by following the path obtained by a-star. the follower robot is requested to follow the leader by maintaining a distance of 1.5 meters and an angle of -0.5236 radians relative to the leader. the starting positions of leader and follower are [1.50, 6.50, 0.524], and [1.00, 8.50, 0.175], respectively. the goal position is [10.5, 6.5, -0.767], while the position of the obstacle is [5.5, 6.5]. the leader’s final position is [10.43, 6.56, -0.763] and the follower’s final position is [8.95, 6.78, -0.753]. figure 6 shows this experiment, which lasted 156.099 seconds. leader follower 𝐹𝑎𝑡𝑡 𝐹𝑡𝑜𝑡 𝐹𝑟𝑒𝑟 obstacle figure 4. interaction of forces in the apf n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 62 c. third experiment two followers were used in this experiment. a vertical obstacle is included in the environment. both follower robots are required to be 1 meter away from the leader. at the same time, one of the follower robots is asked to keep -0.5236 radians away from the leader. the other one is asked to keep it at 0.5236 radians. the leader’s starting position is [1.50, 5.50, 0.000] and the followers’ starting positions are [1.00, 7.50, 0.087], and [1.00, 2.50, 0.175]. the goal position is [10.5, 6.5, 0.775], while the positions of the obstacles are [5.5, 5.5], and [5.5, 6.5]. the leader’s final position is [10.43, 6.44, 0.778] and the followers’ final positions are [10.19, 5.39, 0.782], and [9.45, 6.28, 0.759]. the trajectories of this experiment, which lasted 124.426 seconds to complete, are illustrated in figure 7. d. fourth experiment two followers and a horizontal obstacle were used in this experiment. the two followers must maintain 0 radian in relation to the leader. to prevent followers from colliding with each other, followers are commanded to have different separation distances from the leader. thus, the first figure 5. result of the first experiment obtained using the simulator made in matlab figure 6. result of the second experiment obtained using the simulator made in matlab figure 7. result of the third experiment obtained using the simulator made in matlab n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 63 follower is commanded to keep 1 meter away from the leader and the other one is asked to keep 2 meters away from the leader. the leader’s starting position is [1.50, 6.50, 0.000] and the followers’ starting positions are [1.00, 8.50, 0.000] and [1.00, 3.50, 0.000]. the goal position is [10.5, 6.5, -0.768], while the position of the obstacle is [5.5, 6.5]. the leader’s final position is [10.43, 6.56, -0.765] and the followers’ final positions are [9.71, 7.26, -0.771] and [8.99, 7.95, -0.755]. the trajectories of this experiment, which lasted 245.220 seconds to complete, are illustrated in figure 8. e. fifth experiment in this experiment, 3 followers and a vertical obstacle were considered. the 3 followers are requested to hold 0.3491, 0, and -0.3491 radians from the leader robot, respectively. follower 1 should be 2.5 meters away from the leader. follower 2 should be 1 meter away from the leader. follower 3 should be 2.5 meters away from the leader. the leader’s starting position is [1.50, 6.50, 0.000] and the followers’ starting positions are [-0.50, 8.50, 0.00], [0.50, 6.00, 0.000], and [-0.50, 4.50, 0.000]. the goal position is [10.5, 6.5, -0.785] and the obstacles’ positions are [5.5, 5.5], [5.5, 6.5], and [5.5, 7.5]. the leader’s final position is [10.44, 6.57, -0.803] and the followers’ final positions are [9.47, 8.88, -0.894], [9.74, 7.29, -0.802], and [8.16, 7.61, -0.804]. figure 9 shows this experiment, which lasted 262.800 seconds. f. sixth experiment in this experiment, 4 followers and a horizontal obstacle were selected. the vector [0.6981, 0, 0, -0.6981] was used to define the desired angles of the four followers. the vector [2.5, 1, 2, 2.5] was used to define the desired distances of the four followers relative to the leader. the leader’s starting position is [1.50, 6.50, 0.000] and the followers’ starting positions are [-3.50, 8.50, 0.000], [-1.50, 6.00, 0.000], [0.50, 3.50, 0.000], and [-2.50, 4.50, 0.000]. the goal position is [10.5, 6.5, -0.766] and the obstacle’s position is [5.5, 6.5]. the leader’s final position is [10.43, 6.56, -0.765] and the followers’ final positions are [10.91, 9.02, -0.981], [9.71, 7.26, -0.859], [8.99, 7.95, -0.773], and [7.998, 5.99, -0.601]. the trajectories of this experiment, which lasted 277.587 seconds to complete, are illustrated in figure 10. g. seventh experiment four follower robots and vertical obstacles were used to simulate this experiment. the vector [0.5236, 0, 0, -0.5236] is used to define the desired angles of the follower robots and the vector [2.5, 1, 2, 2.5] is used to define the distance of the follower robots relative to the leader robot. the leader’s starting position is [1.50, 5.50, 0.000] and the followers’ figure 8. result of the fourth experiment obtained using the simulator made in matlab figure 9. result of the fifth experiment obtained using the simulator made in matlab n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 64 starting positions are [-3.50, 7.50, 0.000], [-1.50, 5.00, 0.000], [0.50, 2.50, 0.000], and [-2.50, 3.50, 0.000]. the goal position is [10.5, 6.5, 0.767] and the obstacles’ positions are [5.5, 5.5], and [5.5, 6.5]. the leader’s final position is [10.43, 6.44, 0.768] and the followers’ final positions are [7.96, 6.05, 0.778], [9.71, 5.74, 0.743], [8.99, 5.05, 0.735], and [9.96, 3.98, 0.761]. figure 11 shows this experiment, which lasted 185.760 seconds. h. comparison of distance and orientation errors in this subsection, the distance and orientation errors measured in each experiment are presented. the errors of the leaders were measured in relation to the goal position, while the errors of the followers were measured using as reference the desired values of angle and distance in relation to the leaders. figure 12 to figure 18 depict the distance and orientation errors for each experiment. the leaders’ distance errors remained practically constant in all experiments. the leader’s orientation errors are smaller than those of followers in all experiments, except in experiments four and five. with the exception of experiment 1, the followers’ distance errors are relatively smaller than the leaders’ ones in all experiments. overall, it can be noticed that the values of both distance and orientation errors do not exceed 0.1 m and 0.1 rad, respectively. figure 10. result of the sixth experiment obtained using the simulator made in matlab figure 11. result of the seventh experiment obtained using the simulator made in matlab figure 12. distance and orientation errors corresponding to the first experiment n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 65 figure 13. distance and orientation errors corresponding to the second experiment figure 14. distance and orientation errors corresponding to the third experiment figure 15. distance and orientation errors corresponding to the fourth experiment figure 16. distance and orientation errors corresponding to the fifth experiment n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 66 iv. conclusion in this paper, the formation control of differential mobile robots using the leader-follower approach was presented. as seen in the simulations, the a-star algorithm was used to obtain the safe path, then this path was sent to the leader. follower robots receive information about the leader's position and maintain the desired distance and angles in relation to the leader robot. a controller that allows real-time obstacle avoidance (artificial potential fields) is used to allow followers to travel on safe paths. it is also important to emphasize that the conclusions made here are based on simulations and theoretical knowledge. although the results obtained are successful in the virtual environment, it should be noted that, in the real world, some parameters of the applied controllers may need to be modified to achieve the same performance as in the virtual environment. this is because in the real world, there are many uncertainties that may not have been considered during the simulations. declarations author contribution all authors contributed equally as the main contributor to this study. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] k. h. kowdiki, r. k. barai, and s. bhattacharya, “leaderfollower formation control using artificial potential functions: a kinematic approach,” ieee-international conf. adv. eng. sci. manag. icaesm-2012, pp. 500–505, 2012. [2] a. alouache and q. wu, “performance comparison of consensus protocol and l-phi approach for formation control of multiple nonholonomic wheeled mobile robots,” j. mechatronics, electr. power, veh. technol., vol. 8, no. 1, pp. 22–32, jul. 2017. figure 17. distance and orientation errors corresponding to the sixth experiment figure 18. distance and orientation errors corresponding to the seventh experiment https://mev.lipi.go.id/ https://ieeexplore.ieee.org/document/6216054 https://ieeexplore.ieee.org/document/6216054 https://ieeexplore.ieee.org/document/6216054 https://ieeexplore.ieee.org/document/6216054 https://www.ijrer.org/10.14203/j.mev.2017.v8.22-32 https://www.ijrer.org/10.14203/j.mev.2017.v8.22-32 https://www.ijrer.org/10.14203/j.mev.2017.v8.22-32 https://www.ijrer.org/10.14203/j.mev.2017.v8.22-32 https://www.ijrer.org/10.14203/j.mev.2017.v8.22-32 n.l. manuel et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 57-67 67 [3] l. pacheco and n. luo, “testing pid and mpc performance for mobile robot local path-following,” int. j. adv. robot. syst., vol. 12, no. 11, p. 155, nov. 2015. [4] s. hiroi and m. niitsuma, “building a map including moving objects for mobile robot navigation in living environments,” in 2012 ninth international conference on networked sensing (inss), jun. 2012, pp. 1–2. [5] w.-y. lee, k. hur, k. hwang, d.-s. eom, and j.-o. kim, “mobile robot navigation using wireless sensor networks without localization procedure,” wirel. pers. commun., vol. 62, no. 2, pp. 257–275, jan. 2012. [6] s.-l. dai, s. he, x. chen, and x. jin, “adaptive leader–follower formation control of nonholonomic mobile robots with prescribed transient and steady-state performance,” ieee trans. ind. informatics, vol. 16, no. 6, pp. 3662–3671, jun. 2020. [7] j. hirata-acosta, j. pliego-jiménez, c. cruz-hernádez, and r. martínez-clark, “leader-follower formation control of wheeled mobile robots without attitude measurements,” appl. sci., vol. 11, no. 12, p. 5639, jun. 2021. [8] t. dewi, c. sitompul, p. risma, y. oktarina, r. jelista, and m. mulyati, “simulation analysis of formation control design of leader-follower robot using fuzzy logic controller,” in 2019 international conference on electrical engineering and computer science (icecos), oct. 2019, pp. 68–73. [9] j. dong, s. liu, and k. peng, “formation control of multirobot based on i/o feedback linearization and potential function,” math. probl. eng., vol. 2014, pp. 1–6, 2014. [10] m. a. kamel and y. zhang, “decentralized leader-follower formation control with obstacle avoidance of multiple unicycle mobile robots,” in 2015 ieee 28th canadian conference on electrical and computer engineering (ccece), may 2015, pp. 406–411. [11] h. xiao and c. l. p. chen, “leader-follower consensus multirobot formation control using neurodynamic-optimizationbased nonlinear model predictive control,” ieee access, vol. 7, no. 9, pp. 43581–43590, 2019. [12] h. xiao, z. li, and c. l. philip chen, “formation control of leader–follower mobile robots’ systems using model predictive control based on neural-dynamic optimization,” ieee trans. ind. electron., vol. 63, no. 9, pp. 5752–5762, sep. 2016. [13] y. zhao, y. zhang, and j. lee, “lyapunov and sliding mode based leader-follower formation control for multiple mobile robots with an augmented distance-angle strategy,” int. j. control. autom. syst., vol. 17, pp. 1314–1321, 2019. [14] j. heikkinen, t. minav, and a. d. stotckaia, “self-tuning parameter fuzzy pid controller for autonomous differential drive mobile robot,” proc. 2017 20th ieee int. conf. soft comput. meas. scm 2017, pp. 382–385, 2017. [15] r. siegwart, i. r. nourbakhsh, and d. scaramuzza, introduction to autonomous mobile robots, 2nd ed. cambridge, ma: mit press, 2011. [16] t. zhang, p. w. stackhouse, b. macpherson, and j. c. mikovitz, “a solar azimuth formula that renders circumstantial treatment unnecessary without compromising mathematical rigor: mathematical setup, application and extension of a formula based on the subsolar point and atan2 function,” renew. energy, vol. 172, pp. 1333–1340, 2021. [17] i. m. zidane and k. ibrahim, “wavefront and a-star algorithms for mobile robot path planning,” adv. intell. syst. comput., vol. 639, pp. 69–80, 2018. [18] r. l. galvez et al., “obstacle avoidance algorithm for swarm of quadrotor unmanned aerial vehicle using artificial potential fields,” in tencon 2017 2017 ieee region 10 conference, nov. 2017, pp. 2307–2312. [19] a. azzabi and k. nouri, “path planning for autonomous mobile robot using the potential field method,” in 2017 international conference on advanced systems and electric technologies (ic_aset), jan. 2017, pp. 389–394. https://doi.org/10.5772/61312 https://doi.org/10.5772/61312 https://doi.org/10.5772/61312 https://doi.org/10.1109/inss.2012.6240564 https://doi.org/10.1109/inss.2012.6240564 https://doi.org/10.1109/inss.2012.6240564 https://doi.org/10.1109/inss.2012.6240564 https://doi.org/10.1007/s11277-010-0052-2 https://doi.org/10.1007/s11277-010-0052-2 https://doi.org/10.1007/s11277-010-0052-2 https://doi.org/10.1007/s11277-010-0052-2 https://doi.org/10.1109/tii.2019.2939263 https://doi.org/10.1109/tii.2019.2939263 https://doi.org/10.1109/tii.2019.2939263 https://doi.org/10.1109/tii.2019.2939263 https://doi.org/10.3390/app11125639 https://doi.org/10.3390/app11125639 https://doi.org/10.3390/app11125639 https://doi.org/10.3390/app11125639 https://doi.org/10.1109/icecos47637.2019.8984433 https://doi.org/10.1109/icecos47637.2019.8984433 https://doi.org/10.1109/icecos47637.2019.8984433 https://doi.org/10.1109/icecos47637.2019.8984433 https://doi.org/10.1109/icecos47637.2019.8984433 https://doi.org/10.1155/2014/874543 https://doi.org/10.1155/2014/874543 https://doi.org/10.1155/2014/874543 https://doi.org/10.1109/ccece.2015.7129312 https://doi.org/10.1109/ccece.2015.7129312 https://doi.org/10.1109/ccece.2015.7129312 https://doi.org/10.1109/ccece.2015.7129312 https://doi.org/10.1109/ccece.2015.7129312 https://doi.org/10.1109/access.2019.2907960 https://doi.org/10.1109/access.2019.2907960 https://doi.org/10.1109/access.2019.2907960 https://doi.org/10.1109/access.2019.2907960 https://doi.org/10.1109/tie.2016.2542788 https://doi.org/10.1109/tie.2016.2542788 https://doi.org/10.1109/tie.2016.2542788 https://doi.org/10.1109/tie.2016.2542788 https://doi.org/10.1109/tie.2016.2542788 https://doi.org/10.1007/s12555-018-0194-7 https://doi.org/10.1007/s12555-018-0194-7 https://doi.org/10.1007/s12555-018-0194-7 https://doi.org/10.1007/s12555-018-0194-7 https://doi.org/10.1109/scm.2017.7970592 https://doi.org/10.1109/scm.2017.7970592 https://doi.org/10.1109/scm.2017.7970592 https://doi.org/10.1109/scm.2017.7970592 https://dl.acm.org/doi/10.5555/1971970 https://dl.acm.org/doi/10.5555/1971970 https://dl.acm.org/doi/10.5555/1971970 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1016/j.renene.2021.03.047 https://doi.org/10.1007/978-3-319-64861-3_7 https://doi.org/10.1007/978-3-319-64861-3_7 https://doi.org/10.1007/978-3-319-64861-3_7 https://doi.org/10.1109/tencon.2017.8228246 https://doi.org/10.1109/tencon.2017.8228246 https://doi.org/10.1109/tencon.2017.8228246 https://doi.org/10.1109/tencon.2017.8228246 https://doi.org/10.1109/aset.2017.7983725 https://doi.org/10.1109/aset.2017.7983725 https://doi.org/10.1109/aset.2017.7983725 https://doi.org/10.1109/aset.2017.7983725 introduction ii. materials and methods a. kinematic model of differential mobile robot b. stability analysis using lyapunov a-star algorithm d. artificial potential fields iii. results and discussions a. first experiment b. second experiment third experiment d. fourth experiment e. fifth experiment f. sixth experiment g. seventh experiment comparison of distance and orientation errors iv. conclusion declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology volume 09, 2018 authors index the articles in this volume were authored/co-authored by 45 authors from bulgaria, indonesia, saudi arabia, slovakia, south korea, united kingdom, and viet nam. abdul hapid, “implementation of a lifepo4 battery charger for cell balancing application,” 09(2): 81-88 achmad praptijanto, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 agus purwadi, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 amin, “implementation of a lifepo4 battery charger for cell balancing application,” 09(2): 81-88 ahmad dimyani, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 anton suprayudi, “enhancement of motionability based on segregation of states for holonomic soccer robot,” 09(2): 73-80 arief syaichu rohman, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 arifin nur, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 arif rahman hakim, “an energy and exergy analysis of photovoltaic system in bantul regency, indonesia,” 09(1): 1-7 bambang wahono, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 carmadi machbub, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 cyriel diels, “preliminary investigation of sleep-related driving fatigue experiment in indonesia,” 09(1): 8-16 daniel santoso, “enhancement of motionability based on segregation of states for holonomic soccer robot,” 09(2): 73-80 dao minh duc, “study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder, ” 09(2): 65-72 dicky dectaviansyah, “design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav),” 09(1): 32-40 egi hidayat, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 estiko rijanto, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.81-88 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.81-88 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.1-7 http://dx.doi.org/10.14203/j.mev.2018.v9.1-7 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.8-16 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.32-40 http://dx.doi.org/10.14203/j.mev.2018.v9.32-40 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi gesang nugroho, “design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav),” 09(1): 32-40 gunawan dewantoro, “enhancement of motionability based on segregation of states for holonomic soccer robot,” 09(2): 73-80 kadek heri sanjaya, “preliminary investigation of sleep-related driving fatigue experiment in indonesia,” 09(1): 8-16 khusnul hidayat, “efficiency improvement of photovoltaic by using maximum power point tracking based on a new fuzzy logic controller,” 09(2): 57-64 kristian ismail, “implementation of a lifepo4 battery charger for cell balancing application,” 09(2): 8188 le thi thuy tram, “study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder, ” 09(2): 65-72 machmud effendy, “efficiency improvement of photovoltaic by using maximum power point tracking based on a new fuzzy logic controller,” 09(2): 57-64 marek gašparík, “pendulum energy harvester with amplifier, ” 09(1): 25-31 michal černý, “pendulum energy harvester with amplifier, ” 09(1): 25-31 michal dzurilla, “pendulum energy harvester with amplifier, ” 09(1): 25-31 miloš musil, “pendulum energy harvester with amplifier, ” 09(1): 25-31 muhammad khristamto aditya wardana, “thermal efficiency and emission characteristics of a dieselhydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 mulia pratama, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 nuralif mardiyah, “efficiency improvement of photovoltaic by using maximum power point tracking based on a new fuzzy logic controller,” 09(2): 57-64 ocktaeck lim, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 petar nakov, “condition assessment of power transformers status based on moisture level using fuzzy logic techniques,” 09(1): 17-24 pham dang phuoc, “study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder, ” 09(2): 65-72 putri wullandari, “an energy and exergy analysis of photovoltaic system in bantul regency, indonesia,” 09(1): 1-7 rina ristiana, “designing optimal speed control with observer using integrated battery-electric vehicle (ibev) model for energy efficiency,” 09(2): 89-100 shaun hutchinson, “preliminary investigation of sleep-related driving fatigue experiment in indonesia,” 09(1): 8-16 suherman, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 syed yousufuddin, “combustion duration influence on hydrogen-ethanol dual fueled engine emissions: an experimental analysis,” 09(2): 41-48 tran xuan tuy, “study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder, ” 09(2): 65-72 vezir rexhepi, “condition assessment of power transformers status based on moisture level using fuzzy logic techniques,” 09(1): 17-24 wahyu tri handoyo, “an energy and exergy analysis of photovoltaic system in bantul regency, indonesia,” 09(1): 1-7 http://dx.doi.org/10.14203/j.mev.2018.v9.32-40 http://dx.doi.org/10.14203/j.mev.2018.v9.32-40 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.73-80 http://dx.doi.org/10.14203/j.mev.2018.v9.8-16 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.81-88 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.25-31 http://dx.doi.org/10.14203/j.mev.2018.v9.25-31 http://dx.doi.org/10.14203/j.mev.2018.v9.25-31 http://dx.doi.org/10.14203/j.mev.2018.v9.25-31 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.57-64 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.17-24 http://dx.doi.org/10.14203/j.mev.2018.v9.17-24 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.1-7 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.89-100 http://dx.doi.org/10.14203/j.mev.2018.v9.8-16 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.41-48 http://dx.doi.org/10.14203/j.mev.2018.v9.41-48 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.65-72 http://dx.doi.org/10.14203/j.mev.2018.v9.17-24 http://dx.doi.org/10.14203/j.mev.2018.v9.17-24 http://dx.doi.org/10.14203/j.mev.2018.v9.1-7 http://dx.doi.org/10.14203/j.mev.2018.v9.1-7 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii widodo budi santoso, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 yanuandri putrasari, “thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel ci engine at various load conditions,” 09(2): 49-56 yukhi mustaqim kusuma sya'bana, “preliminary investigation of sleep-related driving fatigue experiment in indonesia,” 09(1): 8-16 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.49-56 http://dx.doi.org/10.14203/j.mev.2018.v9.8-16 http://dx.doi.org/10.14203/j.mev.2018.v9.8-16 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii journal of mechatronics, electrical power, and vehicular technology volume 09, 2018 affiliation index centre for mobility and transport, coventry university, coventry, united kingdom 8 department of electrical and electronics, technological colleges quang nam, quang nam, city, viet nam 65 department of mechanical and industrial engineering, faculty of engineering, universitas gadjah mada, yogyakarta, indonesia 32 department of mechanical engineering, jubail university college, jubail, saudi arabia 41 electrical department, university of muhammadiyah malang, malang, indonesia 57 faculty of electronics and computer engineering, satya wacana christian university, salatiga, indonesia 73 faculty of engineering technology, pham van dong university, quang ngai city, viet nam 65 faculty of mechanical engineering, slovak university of technology, bratislava, slovakia 25 graduate school of mechanical engineering university of ulsan, ulsan, south korea 49 faculty of mechanical, university of science and technology, da nang city, viet nam 65 instrumentation development unit, indonesian institute of sciences (lipi), bandung, indonesia 89 loka riset mekanisasi pengolahan hasil perikanan, badan riset dan sumber daya manusia, kementerian kelautan dan perikanan, bantul, indonesia 1 research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), bandung, indonesia 8, 49, 81, 89 school of electrical engineering and informatics, institut teknologi bandung, bandung, indonesia 89 school of mechanical engineering university of ulsan, ulsan, south korea 49 technical university of sofia, faculty of electrical engineering, sofia, bulgaria 17 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gdg. 230 kawasan puspiptek serpong tangerang selatan, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia aji prasetya wibawa, ph.d. department of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. phh. mustafa no. 23, bandung, jawa barat, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed timeframe, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusio n in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted.  heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot.  heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot.  heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket  heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket.  heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and postpublication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvii instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. lowquality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points:  make sure you use uniform lettering and sizing of your original artwork.  preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier.  number the illustrations according to their sequence in the text.  use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below):  eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xviii  tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi.  tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi.  tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not:  supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low.  supply files that are too low in resolution.  submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]—do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows  book: author, title. edition, editor , city, state or country: publisher, year, pages.  part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages.  periodical: author, “title”, journal, volume (issue), pages, month, year.  proceeding: author, “title”, in proceeding, year, pages.  unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year.  paten/standart: author, “title”, patent number, month day, year.  technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows:  book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file.  periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file.  papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file.  reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.95-101 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt) tri admono a, *, yoyon ahmudiarto a, amma muliya romadoni a, iman abdurahman a, agus salim a, teguh tri lusijarto a, mochammad agoes mulyadi b a research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 20, bandung 40135, indonesia b department of aeronautics and astronautics, bandung institute of technology jl. ganesa no.10, lb. siliwangi, bandung, west java, 40132, indonesia received 23 september 2020; accepted 11 november 2020; published online 22 december 2020 abstract strut is used in vertical axis wind turbine (vawt) to restraint the framework. in this study, struts are analyzed to show the pressure losses in vawt. ansys computational fluid dynamics (cfd) software is used to investigate triangle strut in vawt. this study aims to show a cfd simulation of struts, which affects the aerodynamic of vawt. in cfd software, the aerodynamic of vawt can be analyzed in terms of pressure losses in the struts. the simulation method starts by making a struts model, then meshing and setting up ansys's boundary conditions. the last iteration runs in ansys until convergence. our results show the percentage of pressure losses with the variation of the angle of wind 0°, 20°, 40°, and 60° are 0.67 %, 0.52 %, 0.48 %, and 0.52 %. the effect of triangle strut in vawt did not affect the wind flow to the vawt blade. the results also indicated that the triangle strut could be applied in the multi-stage of vawt system. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: vertical axis wind turbine (vawt); triangle strut; computational fluid dynamics (cfd); pressure losses. i. introduction nowadays, people are interested in using renewable energy because of its zero emissions and also reduce the dependence on fossil fuels [1]. with the growth of the demand for application in renewable energy, the wind turbine is implemented in the urban environment. however, the design of the wind turbine must be considered, especially the design of the strut [2]. vertical axis wind turbine (vawt) different from the horizontal axis wind turbine (hawt) in rotor kinematics, rotor aerodynamics, and wake structure [3]. in the wake structure, a strut keeps the wind turbine stable in the framework. the strut of vawt is a crucial component. as such, an engineer must consider the strut to have a good performance for vawt. in the vertical axis turbine, commonly there are two configurations of the turbine, namely openended and squirrel-wheel design, as shown in figure 1 [4]. in the open-ended type usually used in the wind turbine, the blade is connected to the turbine axis using struts. the number of struts to support the blades varies, depending on the geometry of the turbine, length, radius, solidity, and blade size. on the other hand, squirrel-wheel type, or closed-type with the circle in shape usually used in marine turbines. in any case, both open-ended and squirrelwheel can be applied in the wind or marine turbine. investigating vawt strut is substantial because it is related to the aerodynamics of wind turbines. any interference can affect the pressure losses of vawt, (a) (b) figure 1. (a) open-ended type; (b) squirrel-wheel type * corresponding author. tel: +62-813-2059-4714 e-mail address: tri.admono@yahoo.com https://dx.doi.org/10.14203/j.mev.2020.v11.95-101 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.95-101 https://dx.doi.org/10.14203/j.mev.2020.v11.95-101 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.95-101&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ t. admono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 96 which is a crucial factor in the performance of vawt. when the wind flows to the vawt blade, the velocity and pressure change due to the strut surrounding the blade. therefore, the aerodynamic effect of the strut needs to be investigated when analyzing and designing struts [5][6][7]. computational fluid dynamics (cfd) is a numerical tool used to solve aerodynamic phenomena. cfd can accurately predict the phenomenon between the strut and its surrounding. many studies have been applied to evaluate the aerodynamic models for vawt that can predict aerodynamic performance [8][9][10]. in this study, the ansys fluent cfd software is used to analyze triangle strut in vawt utilizing the pressure losses caused by a strut. a triangle strut on the top and bottom side was chosen because it can be applied by a multi-stage vawt system. we assumed that cfd simulation can be executed in a short period using physical experiments and tests to get the data, such as pressure loss, velocity, etc. this research was conducted between the research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), and the department of aeronautics and astronautics, bandung institute of technology (itb). results of the cfd simulation will be applied to the design of vawt, located in sumedang. ii. materials and methods this research focused on analyzing the effect of triangle strut in vawt pressure losses. ansys computational fluid dynamics (cfd) method applied in this case. generally, cfd consist of several governing equations, such as continuity equations, navier-stokes equations, and energy equations [11]. the simulation is performed in 2d and 3d. furthermore, the object is considered by steadystate, incompressible, isothermal, and viscous flow. the domain was stationary and turbulent model kepsilon applied in simulation. the continuity equation is the fundamental law of the mass conservation equation. the law of mass conservation is defined as a change in mass in the volume control (cv) equal to the net rate of mass entering cv [12]. the conservation equation for mass in integrals is as follows: 𝜕 𝜕𝜕 ∫ 𝜌. 𝑑𝑑𝐶𝐶 +∫ 𝜌u𝐶𝐶 .𝑛�⃑ .da = 0, ∀v∈r (1) equation (1) can be converted to the differential using gauss divergence theorem: �̇�+∇ (𝜌u) = 0 (2) where 𝜌 is density (kg/m3), u is flow velocity (m/s), and ∇ is density divergence term (differential operator) ∇ = 𝜕 𝜕𝜕 + 𝜕 𝜕𝜕 + 𝜕 𝜕𝜕 (3) the equation in incompressible viscous flow described in the navier-stokes equation: 𝜕𝑢�𝑖 𝜕𝜕 + 𝑢�𝑗 𝜕𝑢�𝑖 𝜕𝜕𝑗 = − 𝜕�̅� 𝜕𝜕𝑖 + 𝑣 𝜕²𝑢 �𝑖 𝜕𝜕𝑗𝜕𝜕𝑗 − 𝜕𝜏𝑖𝑗 𝜕𝜕𝑗 (4) the tensor of the velocity vector is 𝜏𝑖𝑗 𝜏𝑖𝑗 = �́�𝚤�́�𝚥����� (5) the velocity of the fluid must be equal to zero because no-slip condition for a viscous fluid. 𝜕𝑢�𝑖 𝜕𝜕𝑖 = 0 (6) where 𝑢𝑖 is fluid velocity (m/s), p is pressure (pa), and v is kinematic viscosity (m2/s). in this study, vawt type with darrieus blade installed with triangle struts. generally, in the darrieus model, the radial arms connect the shaft at one end and the inner side of the turbine blade at another one [13]. so, the velocity inlet can affect the aerodynamic of the vawt from the radial arm and the shaft. figure 2 shows the darrieus blade with the flow of inlet velocity. figure 3 shows the pressure distribution of the cylinder shape. in the cylinder shape from the area of shaft or strut, there is a pressure loss affected by inlet pressure [14]. the percentage of pressure losses can be calculated from data between inlet and reference pressure: 𝑃𝑖𝑛𝑖𝑖𝑖−𝑃𝑟𝑖𝑟𝑖𝑟𝑖𝑛𝑟𝑖 𝑃𝑟𝑖𝑟𝑖𝑟𝑖𝑛𝑟𝑖 × 100% = percentage of pressure losses(7) there are a few steps required before the cfd calculation. in the beginning, the model is developed before the mesh is carefully generated to ensure the quality of the simulation. the next step is to set the boundary conditions and conditions for the iterations. lastly, the computation is started through iterations until the solution is found when it reaches the pre-defined convergence criteria [15]. figure 4 shows the step of the simulation. figure 2. inlet velocity to the vawt darrieus blade figure 3. pressure distribution around the cylinder shape figure 4. simulation steps t. atmono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 97 a. geometry the triangle strut is made for a multi-stage vertical axis wind turbine (vawt) which can be installed portable in the urban or rural area. therefore, a special design is needed, different from the general strut. in this research, the design of the strut on the top and bottom is a triangle shape. so, the stand frame follows to support the struts. figure 5 shows the design of the triangle strut with the blade. figure 6 shows the dimension of the strut. the diameter of the strut support is 90 mm. each blade stage has a space of 3000 mm. in the middle, there are 500 mm of space for the multi-stage vawt generator. in this study, simulation progress only in a single stage without the blade, to focus on triangle strut. b. meshing & processing meshing is a fundamental process in cfd simulation to define finite volume in the object. figure 7 shows the 2d mesh structure in object simulation. boundary condition set up at inlet, outlet, and wall. to make sure the quality of the mesh, figure 8 shows graphic distribution from 0.2 to 1. the quality mesh is excellent because it is evenly distributed and using triangular/tetrahedral. the total of number elements is 11300. in this research, cfd simulation used ansys fluent package. the object is simulated under the steady-state condition and the turbulent model used is k epsilon. the turbulent flow regime is subsonic. the reference pressure is 1 atm and the wind velocity is 6 m/s. the flow regime is subsonic. the angle of wind direction varies from 0, 20, 40, and 60 degrees. firstly, the simulation process is carried out in a 2d object, before for comparison purposes, the simulation is run with the 3d object. iii. results and discussions a. results of the 2d strut figure 9 shows the contour of the velocity vector and total pressure in a 2d object. from figure 9a, the contour of the velocity vector at 0 degrees of wind direction did not distract the aerodynamic of the system. maximum velocity of 12.55 m/s distracts the little area in the circle point of the strut. the triangle strut does not produce a big distraction to the (a) (b) figure 5. (a) initial triangle strut design; (b) triangle strut design with blade turbine (a) (b) figure 6. multi-stage triangle strut: (a) isometry view; (b) top view t. admono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 98 system aerodynamic. furthermore, figure 9b shows a small effect of the pressure. the inlet pressure is 29.3858 pa and the total pressure is 29.2293 pa. from the data, the percentage of pressure loss is 0.53 %. table 1 presents the variation of pressure losses from different angles of wind. small difference data between the inlet and total pressure in 2d simulation indicate that are good in the results. figure 7. mesh 2d structure of vawt figure 8. quality of the mesh table 1. pressure losses at variations of degree in 2d no angle of wind direction (degree) inlet total pressure (pa) total pressure 𝑨𝒓𝒓𝒓 (pa) percentage of losses (%) 1. 0 29.3858 29.2293 0.53 2. 20 29.4473 29.3472 0.34 3. 40 29.4216 29.2833 0.47 4. 60 29.0955 28.9528 0.49 t. atmono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 99 b. results of 3d strut figure 10 shows the velocity vector and total pressure in a 3d object. figure 10a shows the contour of the velocity vector at 0 degrees of wind direction with the maximum velocity at 12.87 m/s. the triangle strut does not produce a big distraction of aerodynamic to the system, except in the little area of the strut. furthermore, figure 10b shows the small effect of the pressure, that is the inlet pressure of 29.83 pa and the total pressure of 29.63 pa. from the data, the percentage of pressure loss is 0.67 %. table 2 presents the variation of data of pressure losses from a different angle of wind direction. small difference data between the inlet and total pressure in 3d simulation indicate that this is a good sign in the results. (a) (b) figure 9. the contour of: (a) velocity vector; and (b) pressure in 2d object table 2. pressure losses at variations of degree in 3d no angle of wind direction (degree) inlet total pressure (pa) total pressure 𝑹𝒓𝒓 (pa) percentage of losses (%) 1. 0 29.83 29.63 0.67 2. 20 29.96 29.81 0.52 3. 40 29.76 29.62 0.48 4. 60 29.45 28.29 0.52 t. admono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 100 table 3 shows data of pressure losses comparison between 2d and 3d of triangle strut. in the angle of wind direction, 0 degrees has a difference of 0.14 %, which shows that the data are close. therefore, the data are correct in 2d or 3d simulation. when the angle is 20 degrees, it has a difference of 0.18 %, which shows that the data are also close. in the angle of wind direction, 40 degrees has a difference of 0.01 %, this shows the data are almost similar. in the angle of wind directions, 60 degrees has a difference of 0.03 %, this shows the data are almost similar too. all of the comparison data have little difference and indicate triangle strut did not distract the aerodynamic of the vawt system. (a) (b) figure 10. the contour of: (a) velocity vector; (b) pressure in 3d object table 3. comparison of pressure losses 2d and 3d no angle of wind direction (degree) percentage of losses 2d (%) percentage of losses 3d (%) difference (%) 1. 0 0.53 0.67 0.14 2. 20 0.34 0.52 0.18 3. 40 0.47 0.48 0.01 4. 60 0.49 0.52 0.03 t. atmono et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 95-101 101 iv. conclusion in this research, a triangle strut design for multistage vawt is investigated using computational fluid dynamics (cfd) software. the main goal is to analyze the effect of triangle strut design on the aerodynamic vawt system. from cfd simulation software, little distractions are surrounding the strut and did not affect the wind flow to the vawt blade. at the angle of wind direction 0, 20, 40, and 60 degrees, percentage of pressure losses are 0.67 %, 0.52 %, 0.48 %, and 0.5 2 %. therefore, triangle strut is suitable to be applied in multi-stage vertical axis wind turbine (vawt). acknowledgement this research is supported by the research centre for electrical and mechatronics, indonesia institute of science (lipi) bandung, indonesia. we are also immensely grateful to all lecturers of the department of aeronautics and astronautics, bandung institute of technology, indonesia, who is joined in this research. declarations author contribution t. admono, y. ahmudiarto, a.m. romadoni, and m.a. mulyadi contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] s. siddiqui, n. durrani, and i. akhtar, “ numerical study to quantify the effects of struts & central hub on the performance of a three-dimensional vertical axis wind turbine using sliding mesh,” in proceedings of the asme 2013 power conference, 2013, pp. 1– 11. [2] y. bazilevs, a. korobenko, x. deng, j. yan, m. kinzel, and j. o. dabiri, “ fluid – structure interaction modeling of verticalaxis wind turbines,” j. appl. mech., vol. 81, no. august, pp. 1– 8, 2014. [3] t. c. hohman, l. martinelli, and a. j. smits, “ the effects of inflow conditions on vertical axis wind turbine wake structure and performance,” j. wind eng. ind. aerodyn., vol. 183, no. october, pp. 1– 18, 2018. [4] a. goude, s. lundin, and m. leijon, “ a parameter study of the influence of struts on the performance of a vertical-axis marine current turbine,” in proceedings of the 8th european wave and tidal energy conference, 2009, pp. 477– 483. [5] p. bachant and m. wosnik, “ performance and near-wake measurements for a vertical axis turbine at moderate reynolds number,” in proceedings of the asme 2013 fluids engineering division summer meeting, 2013, pp. 1– 9. [6] a. r. davari, “ wake structure and similar behavior of wake profiles downstream of a plunging airfoil,” chinese j. aeronaut., no. june, pp. 1– 13, 2017. [7] s. hanchi, t. benkherouf, m. mekadem, and h. oualli, “ wake structure and aerodynamic characteristics of an autopropelled pitching airfoil,” j. fluids struct., vol. 39, pp. 275– 291, 2013. [8] h. lee and d. lee, “ numerical investigation of the aerodynamics and wake structures of horizontal axis wind turbines by using nonlinear vortex lattice method,” renew. energy, 2018. [9] a. posa, c. m. parker, m. c. leftwich, and e. balaras, “ wake structure of a single vertical axis wind turbine,” int. j. heat fluid flow, vol. 0, pp. 1– 10, 2016. [10] y. ahmudiarto, a. m. romadoni, t. b. karyanto, t. admono, b. nugroho, r. c. chin, and a. budiyono, “ performance analysis of novel blade design of vertical axis wind turbine,” in 2019 international conference on sustainable energy engineering and application (icseea), 2019, pp. 175– 181. [11] t. wah-yen, y. asako, n. azwadi, c. sidik, and g. rui-zher, “ governing equations in computational fluid dynamics: derivations and a recent review,” prog. energy environ., no. june, pp. 1– 19, 2017. [12] y. wei, “ the development and application of cfd technology in mechanical engineering the development and application of cfd technology in mechanical engineering,” in iop conf. series: materials science and engineering, 2017, pp. 1– 9. [13] w. liu and q. xiao, “ investigation on darrieus type straight blade vertical axis wind turbine with flexible blade,” ocean eng., vol. 110, pp. 339– 356, 2015. [14] s. ogawa and y. kimura, “ performance improvement by control of wingtip vortices for vertical axis type wind turbine,” open j. fluid dyn., vol. 8, pp. 331– 342, 2018. [15] a. rezaeiha, h. montazeri, and b. blocken, “ towards accurate cfd simulations of vertical axis wind turbines at di fferent tip speed ratios and solidities: guidelines for azimuthal increment, domain size and convergence,” energy convers. manag., vol. 156, no. october 2017, pp. 301– 316, 2018. https://doi.org/10.1115/power2013-98300 https://doi.org/10.1115/power2013-98300 https://doi.org/10.1115/power2013-98300 https://doi.org/10.1115/power2013-98300 https://doi.org/10.1115/power2013-98300 https://doi.org/10.1115/1.4027466 https://doi.org/10.1115/1.4027466 https://doi.org/10.1115/1.4027466 https://doi.org/10.1115/1.4027466 https://doi.org/10.1016/j.jweia.2018.10.002 https://doi.org/10.1016/j.jweia.2018.10.002 https://doi.org/10.1016/j.jweia.2018.10.002 https://doi.org/10.1016/j.jweia.2018.10.002 http://www.homepages.ed.ac.uk/shs/wave%20energy/ewtec%202009/ewtec%202009%20(d)/papers/252.pdf http://www.homepages.ed.ac.uk/shs/wave%20energy/ewtec%202009/ewtec%202009%20(d)/papers/252.pdf http://www.homepages.ed.ac.uk/shs/wave%20energy/ewtec%202009/ewtec%202009%20(d)/papers/252.pdf http://www.homepages.ed.ac.uk/shs/wave%20energy/ewtec%202009/ewtec%202009%20(d)/papers/252.pdf https://doi.org/10.1115/fedsm2013-16575 https://doi.org/10.1115/fedsm2013-16575 https://doi.org/10.1115/fedsm2013-16575 https://doi.org/10.1115/fedsm2013-16575 https://doi.org/10.1016/j.cja.2017.05.007 https://doi.org/10.1016/j.cja.2017.05.007 https://doi.org/10.1016/j.cja.2017.05.007 https://doi.org/10.1016/j.jfluidstructs.2013.02.019 https://doi.org/10.1016/j.jfluidstructs.2013.02.019 https://doi.org/10.1016/j.jfluidstructs.2013.02.019 https://doi.org/10.1016/j.jfluidstructs.2013.02.019 https://doi.org/10.1016/j.renene.2018.08.087 https://doi.org/10.1016/j.renene.2018.08.087 https://doi.org/10.1016/j.renene.2018.08.087 https://doi.org/10.1016/j.renene.2018.08.087 https://doi.org/10.1016/j.ijheatfluidflow.2016.02.002 https://doi.org/10.1016/j.ijheatfluidflow.2016.02.002 https://doi.org/10.1016/j.ijheatfluidflow.2016.02.002 https://doi.org/10.1109/icseea47812.2019.8938639 https://doi.org/10.1109/icseea47812.2019.8938639 https://doi.org/10.1109/icseea47812.2019.8938639 https://doi.org/10.1109/icseea47812.2019.8938639 https://doi.org/10.1109/icseea47812.2019.8938639 https://www.academia.edu/35496249/governing_equations_in_computational_fluid_dynamics_derivations_and_a_recent_review https://www.academia.edu/35496249/governing_equations_in_computational_fluid_dynamics_derivations_and_a_recent_review https://www.academia.edu/35496249/governing_equations_in_computational_fluid_dynamics_derivations_and_a_recent_review https://www.academia.edu/35496249/governing_equations_in_computational_fluid_dynamics_derivations_and_a_recent_review https://doi.org/10.1088/1757-899x/274/1/012012 https://doi.org/10.1088/1757-899x/274/1/012012 https://doi.org/10.1088/1757-899x/274/1/012012 https://doi.org/10.1088/1757-899x/274/1/012012 https://doi.org/10.1016/j.oceaneng.2015.10.027 https://doi.org/10.1016/j.oceaneng.2015.10.027 https://doi.org/10.1016/j.oceaneng.2015.10.027 https://doi.org/10.4236/ojfd.2018.83021 https://doi.org/10.4236/ojfd.2018.83021 https://doi.org/10.4236/ojfd.2018.83021 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 i. introduction ii. materials and methods a. geometry b. meshing & processing iii. results and discussions a. results of the 2d strut b. results of 3d strut iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.22-29 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer aam muharam a, b, *, tarek mahmoud mostafa c, suziana ahmad a, d, mitsuru masuda e, daiki obara e, reiji hattori a, abdul hapid b a applied science for electronics and materials, interdisciplinary graduate school of engineering sciences, kyushu university 6 chome-1 kasugakoen, kasuga, fukuoka 816-8580, japan b research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komp lipi bandung, jl. sangkuriang, west java, 40135, indonesia c computer, electrical, mathematical sciences and engineering (cemse), king abdullah university of science and technology thuwal 23955, saudi arabia d faculty of electrical and electronic engineering technology (ftkee), universiti teknikal malaysia melaka hang tuah jaya 76100, durian tunggal, melaka, malaysia e automotive products and electronics laboratories, furukawa electric co., ltd. 5 chome-1-9 higashiyawata, hiratsuka, kanagawa 254-0016, japan received 03 june 2020; accepted 08 july 2020; published online 30 july 2020 abstract a preliminary study of class-e radio frequency power amplifier for wireless capacitive power transfer (cpt) system is presented in this paper. due to a limitation in coupling capacitance value, a high frequency operation of switching power inverter is necessary for the cpt system. a gan mosfet offers reliability and performance in a high frequency operation with an improved efficiency over a silicon device. design specification related to the parallel load parameter, lc impedance matching and experimental analysis of the amplifier is explored. an experimental setup for the proposed inverter and its integration with the cpt system is provided, and the power efficiency is investigated. as a result, by utilizing a 6.78 mhz resonant frequency and a 50 ω resistive load, 50 w of power has been transmitted successfully with an end to end system efficiency over 81 %. additionally, above 17 w wireless power transfer was demonstrated successfully in the cpt system under 6 pf coupling with the efficiency over 70 %. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: class-e power amplifier; wireless power transfer; capacitive power transfer; high efficiency; high frequency power source. i. introduction in radio frequency (rf), a switching mode power supply (smps) plays an important rule since it is related to the system efficiency. maximum power transfer efficiency can be obtained by minimizing dissipation of power which is mostly happening in power transistor. class-d power amplifiers are usually chosen to convey the transmitter, but it requires at least two transistors to acquire zero voltage switching (zvs), which increases product and process costs. a class-e power amplifier is known as a great efficient power amplifier in rf. it uses a single-ended switching device that works with a resonant network between the switch and the load. the device is activated as an on/off switch and the parallel load network forms the voltage and current waveforms to avoid concurrent high voltage and high current in the transistor during the switching transitions. the conditions of zero current switching (zcs) or zero voltage switching (zvs) can be achieved easily. an invention of class-e power amplifier was conveyed by nathan o. sokal and alan d. sokal in 1972. while the details of publication were announced in 1975 [1] with a complete and comprehensive design also introduced [2]. advance research and technology implemented the class-e amplifier for wireless power transfer (wpt) application, from a low frequency [3] to a high * corresponding author. tel: +81-92-5837887 e-mail address: aam.muharam.101@s.kyushu-u.ac.jp https://dx.doi.org/10.14203/j.mev.2020.v11.22-29 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.22-29 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.22-29&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 23 frequency field [4] includes a charging applications [5][6]. furthermore, research studies related to adaptive and controllable power combiner were also offered [7][8]. it is difficult to change the regeneration frequency due to the limitation of the ism band for mhz wpt. typically, a fixed frequency such as 6.78 mh which is the lowest frequency in the globally accepted ism (industrial, scientific and medical) band is preferred. the itu-r (international telecommunication union radio communications sector) currently recommends this single frequency for wireless energy transmission from consumer devices, as it would have little or no negative impact on other licensed bands. a higher operating frequency in ism band, such as 13.56 mhz or 27.12 mhz, can have further improved local freedom. however, it increases switching loss, driving loss and circuit design challenges (e.g. circuit board configuration and component selection) [9]. the most interesting method in wpt is using capacitance coupling interface or known as capacitive power transfer (cpt). figure 1 shows the cpt basic diagram that consists of dc power supply and high frequency dc to ac power converter in the primary side (transmitter) of the cpt. a rectifier is needed to deliver the dc voltage and current to the load in the secondary side (receiver). cpt operates by using electric fields resonant in order to transfer the power wirelessly. two couples of metal plate work as a capacitive interface between the primary and the secondary side. several researches related to an implementation of the cpt have been conducted, such as biomedical sensor and implantable devices to a living object [10][11], drone application [12][13], and electric vehicle charging system [14][15]. research and development of amplifier for wpt have been conducted by engineers. for inductive power transfer (ipt), as the famous method of wpt, an 80 % efficiency was obtained by implementing class-e which has an operating frequency of 6.78 mhz and 20 w of power to 90 ω load [16]. on the other hand, a wpt for battery charging application was carried out by using cpt [17]. it uses a class-d topology of the inverter with frequency switches at 6.78 mhz, providing 4 of delivered power with efficiency over 76 %. research by [18] studies the class-e implemented to the cpt system by generating 9 w power through 1.51 mhz switching amplifier. the efficiency of their inverter was 90.3 % with 2 mm gap and 8.3 loads. its efficiency was higher than the class-e on ipt system, but less power delivered to the load. moreover, its frequency was lower than the allowed level by the ism band regulation. ipt system having an ability to transfer at a longer distance was achieved by [19] and [6] using 6.78 mhz class-e power amplifier, with delivered power over 10 w and 16.3 w, respectively, providing an efficiency over 70 % and 74.2 %, accordingly. these selected researches in power amplifier for wpt applications can be seen in table 1. in this paper, a 50 w high frequency power amplifier is proposed by using the topology of class e with an operating resonant frequency of 6.78 mhz. preliminary design and experiment include an implementation of wireless power transfer by using a capacitive coupling interface are pronounced. the structure of this paper will be divided as follows: section ii describes the proposed class-e power amplifier related to the design specification of parallel load components, impedance circuit and power efficiency identification. the fabrication, the characteristics analysis, and the measured results of the amplifier are discussed in section iii. finally, the conclusions are presented in section iv. ii. materials and methods a. proposed class-e rf power amplifier circuit diagram of a class-e rf power amplifier with impedance matching network to 50 ω load is figure 1. basic diagram of a capacitive wireless power transfer [9] table 1. selected researches in power amplifier for wpt applications ref year topology frequency (mhz) power out (w) gap (mm) load (ω) wpt method efficiency (%) [16] 2015 class-e 6.78 20 n.a. 90 ipt 80 [17] 2015 class-d 6.78 4 0.04 battery cpt 76 [18] 2016 class-e 1.51 9 2 8.3 cpt 90.3 [19] 2019 class-e 6.78 10 22 10 ipt 70 [6] 2020 class-e 6.78 16.3 40 20 ipt 74.2 dc power supply high freq power converter (dc/ac) rectifier (ac/dc) load primary side transmitter secondary side receiver coupling interface a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 24 presented in figure 2. a gan based mosfet is used as the switching transistor since it can operate with low on-resistance at high frequency. the parallel load network consists of a dc choke inductor, lchoke, a parallel shunt capacitor, cp1, a series connected resonant inductor, ls1 and capacitor, cs1. the impedance matching circuit contains a series inductor, ls2, and a parallel capacitor, cp2, and a (commonly 50 ω or 75 ω) load. b. parallel load network specification in order to attain a working properly of switching transistor operation, an optimal parameters of the parallel load network have to be calculated well as described by [2]. with the condition of 50 % duty cycle, the output impedance of the inverter, r, can be assimilated using equation (1) by [20]. ( )20.577 dd outr v p= × (1) where vdd is the voltage biased at drain mosfet and pout is the output power of the designed inverter. a perfect switching transition is rolled by the value of shunt capacitor, cp1, which is obtained by using equation (2): ( )1 0.685pc rω= × , (2) and, the value of dc choke inductor, lchoke can be calculated by using equation (3): 0.732chokel r ω= × . (3) the series resonant inductor ls1 and capacitor cs1, can be acquired by using equations (4) and (5): 1sl q r ω= × . (4) ( )1 1sc q r ω= × × . (5) where ω =2 π f, is the angular frequency of the designed amplifier. r and q mention the output impedance of the inverter and the load quality factor, respectively. its chosen value is a trade-off concerning [2]: • the operational bandwidth, which is wider with lower q value, • the harmonic content of the output power, that will be lower with a higher q, and • the power loss of the parasitic resistances in series resonant, which is lower while lower q. c. impedance matching since most power supply and measurement tools are designed to match to common 50 ω or 75 ω, then the impedance matching component which is capacitor cp2 and inductor lp2 can be expected approximately by using equations (6) and (7): 2 1 1loadp load r c r rω = − × (6) 2 2s p loadl c r r= × × (7) d. power and efficiency the output power is reflected from the acquired load voltage vload over the resistive load rload. while the generated input power is obtained from the dc power source by multiplication of the input dc voltage vdd and current io. from this condition, the power efficiency is then can be calculated by using equation (8): 2 2(w) (v ) ( ) (%) (w) (v) (a) out load load in dd o p v r eff p v i ω = = × (8) the accepted voltage vdd in order to determine the power capability of class-e rf amplifier can be calculated by using equations (9) and (10): 3.65bv ddv v≥ × , (9) max 2.86ds oi i= × . (10) where vbv and idsmax are the breakdown voltage and current flow to the fet, respectively. however, because of the load and coupling variations, the peak voltage across the device can be as high as 7 times the supply voltage [20]. iii. results and discussions this section will give detail results and discussion related to the hardware experiment of the proposed class-e amplifier in delivering the power to the cpt system. the proposed and fabrication of multi-resonant frequency class-e rf power amplifier are shown in figure 3 and figure 4, respectively. the inverter system consists of: an external voltage terminal (a) that is connected to a switching mode power supply (smps) (b) which works rectifying 110 vac to 24 vdc. the output dc figure 2. circuit of class-e power amplifier with impedance matching network a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 25 voltage can be used as internal drain supply voltage when only 24 v needed by the system. moreover, the voltage is supplied to the isolated dc-dc converter that produces a 12 v (c) for gate driver supply voltage and 5 v (d) for the oscillator supply voltage. a multi-resonant oscillator (e) is used to provide a variable operating frequency depending on the system needed. a single gate driver (f) with a heat sink attached is then connected to the switching gan mosfet (g) where its body coupled to the large heat sink. a dc link inductor can be seen in (h) part, while the rf output of the inverter is joined to the lc impedance matching network through a bayonet neill-concelman (bnc) connector. by following the design specification in section ii, a detail list of design index and parameter of the proposed class-e rf power amplifier is presented in table 2. the experiment is carried out by investigating the effect of drain bias voltage changes to the efficiency of the inverter. the testing setup is divided into two schemes, that only class-e rf power amplifier t (device under test, dut) connected directly to the 50 ω resistive load, as the first shown in figure 5. an external dc power source is used and connected to the amplifier external source terminal. the rf output terminal dut uses a bnc connector, is coupled to the matching network circuit. in the end, the 50 ω resistive load is attached to the output terminal of the network. the gate driver, the drain output and the load voltage signals are connected to the tektronix mixed signal oscilloscope mso 4034 by utilizing the voltage probe cable. the second scheme is integrating the inverter to the cpt system in order to transfer the power wirelessly. further explanation will be provided in section d related to the power transfer efficiency. a. gate driver’s signal oscillation characteristics figure 6 illustrates the output signal from the oscillator ic ltc 1799. it can be observed that a clear square wave signal is produced by the ic. even though there are some noises appeared, this signal still succeeds to trigger the gate of switching mosfet. a pure sinusoidal waveform is measured at the load resistance 50 ω with 80 v and 20 v of the peak to peak load voltage and drain voltage operation, respectively. b. drain voltage characteristics the characteristics of the output signal produced from the mosfet drain pin vdrain, load voltage vload and current iload are drawn in figure 7. the peak to peak drain-source voltage vdrain is measured at 182 v. the wide-ranging load voltage and current amplitudes of the amplifier are exposed with almost pure sinusoidal waveform at 132 v and 2.8 a peak to peak, correspondingly. this condition is satisfied when the dc source power 55 w and the ideal resistive load 50 ω. figure 3. proposed multi-resonant frequency class-e rf power amplifier figure 4. fabrication of 6.78 mhz class-e rf power amplifier: (a) external vdd; (b) ac/dc power rectifier; (c) 24 v to 12 v dc-dc converter; (d) 12 v to 5 v dc-dc converter; (e) multi resonant frequency oscillator; (f) gate driver; (g) gan mosfet; (h) choke inductor; and (i) rf output filter and matching circuit a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 26 table 2. design index and parameter list of the 6.78 mhz class-e rf power amplifier parameter (figure 4) components/value/type external vdd (a) external supply voltage ac to dc power rectifier (b) ac/dc 110 vac to 24 vdc smps dc to dc converter (c) ccg152412s tdk-lambda, isolated 15.6w, 9-36 vin 12 vout 1.3 a dc to dc converter (d) traco tme 1205s isolated single output oscillator (e) ltc1799, 1 mhz – 30 mhz gate driver (f) el7104 single channel mosfet (g) tph3212ps 650v gan fet output power, pout 60 w resonant frequency, f 6.78 mhz dc link voltage, vdd 30 v dc link (choke) inductor (h), lchoke 3.35 µh series inductor, ls1 + ls2 1.32 µh series capacitor, cs1 1040 pf matching capacitor, cp2 690 pf figure 5. experimental setup of class-e rf power amplifier amplifier figure 6. gate driver signal oscillation of 6.78 mhz class-e rf power amplifier c. load voltage characteristics the load voltage characteristic with different input voltage to the drain of the mosfet is evaluated. figure 8 illustrates the load voltage signal obtained by generating a changed voltage to the vdd terminal. it can be seen that with the increasing of vdd value will result in a higher amplitude of load voltage. the maximum value of vdd is limited by the switch device breakdown voltage vbv value that defined by the equation (9). d. power and efficiency characteristics class-e amplifier works in the specific resonant frequency determined by its components. the response frequency for power characteristic of the amplifier is shown in figure 9 where, from 4 to 6 mhz of frequency, the delivered power slightly increases from the level of 28 w to 55 w. the inverter delivers power over 56 w when the frequency is in resonant of 6.78 mhz. moreover, the power is decreased linearly for the frequency operation above 7 mhz. a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 27 figure 10 illustrates the power and efficiency of the proposed class-e rf power amplifier with the change of vdd value from 10 v until 36 v in the incremental order of 2 v. while the voltage starts increasing from 10 v to 20 v, the efficiency is improved slightly from the level 61 % up to 78 %. on this condition, the output power is distributed successfully from 5 w to 25 w. moreover, when the output power from 30 w up to 60 w is delivered, the inverter can maintain the efficiency to the level over 80 % with the value of vdd is settled from 22 v to 32 v. in the case of vdd over 32 v, the efficiency of inverter is reduced dramatically to the level of 72 % with the conveyed power touch to 75 w. since the vdd increased, the current flowing to the choke inductor and switch is proportionally increases. from figure 10, it can be seen that the input power is increased gradually compared to linearly for the output power. a higher current flows to the magnetic core inductor produces eddy current loss, furthermore, heat occurs to the core. figure 7. drain voltage characteristic of 6.78 mhz class-e rf power amplifier figure 8. load voltage characteristic with different drain voltage conditions figure 9. frequency response of class-e rf amplifier a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 28 figure 11 describes the experimental setup of class-e rf power amplifier integrated with the capacitive wireless power transfer. the setup consists of an external power supply that connected to the external source terminal of the dut. a matching circuit is linked to the rf output terminal of the inverter, then connected to the step-up transformer in order to increase the rf amplitude. at this point, the output of the transformer attaches to the coupling plate interface of cpt as a transmitter side. the receiver side consists of a commercial dc load having 50 ω contains of led, is connected to the step-down transformer and full bridge rectifier diode that converts the ac sinewave into dc voltage. the efficiency of the class-e rf power amplifier that is integrated into the cpt system is shown in figure 12. it can be viewed that the efficiency is having a reduction from the highest level 81 % to 70 % of the capacitive wireless power transfer in comparison with 6.78 mhz class-e rf power amplifier. the load in cpt system is powered wirelessly through a 6 pf coupling interface with the measured value 16.8 w and 24 w of the output power and the input power, correspondingly. meanwhile, the class-e itself can have an efficiency value of 81 % with the measured power 60 w and over 50 w of the input power and the output power, respectively. figure 12. power and efficiency of 6.78 mhz class-e rf with cpt system figure 10. power and efficiency characteristics of 6.78 mhz class-e rf amplifier amplifier figure 11. experimental setup of capacitive wireless power transfer a. muharam et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 22-29 29 the power loss of the class-e amplifier can be referred to the inductors and capacitors parasitic resistance, as an equivalent series resistance (esr). the other cause is due to manual fabrication of the inductors in which affect to the unmatched impedance network. iv. conclusion this paper has presented a preliminary design and experimental analysis of the class-e rf power amplifier for cpt system. a 50 w power inverter was proposed for 6.78 mhz capacitive wireless power transfer system. by implementing multi-resonant oscillator, gan mosfet and impedance matching to the load, the efficiency of the inverter was observed. the experimental results have revealed that 50 w of power has been transmitted to an end to end system with efficiency over 81 % for the proposed class-e rf power amplifier. furthermore, a wireless power transfer was demonstrated successfully in the cpt system with the efficiency over 70 % for transferring power over 17 w. improvement study of the inverter will need to be considered, especially for precision selection and fabrication of the passive components. acknowledgement the authors would like to thank mr. hiroyuki yamazaki and mr. yusuke nishisako from automotive system and device laboratories, furukawa electric co., ltd. through their technical support and help in preparing experiment and measurement. this research is conducted by the riset-pro scholarship support from the ministry of research technology and higher education (kemenristek-dikti), republic of indonesia (world bank loan no. 8245-id). declarations author contribution conceptualization, a. muharam, d. obara, and m. masuda; methodology, a. muharam and r. hattori; validation, a. muharam and s. ahmad; visualization, a. muharam; writing—original draft preparation, a. muharam; writing—review and editing, s. ahmad, t.m. mostafa, and r. hattori; supervision, m. masuda, a. hapid., and r. hattori. a. muharam, s. ahmad, m. masuda and r. hattori has been contributed equally as the main contributor. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] n.o. sokal and a.d. sokal, “class e-a new class of highefficiency tuned single-ended switching power amplifiers,” ieee j. solid-state circuits, vol. 10, no. 3, pp. 168–176, jun. 1975. [2] n.o. sokal, “class-e rf power amplifiers,” qex american radio relay league, vol. 204, no. 204, pp. 9–20, 2001. [3] d.c. yates, s. aldhaher, and p.d. mitcheson, “a 100-w 94% efficient 6-mhz sic class e inverter with a sub 2-w gan resonant gate drive for ipt,” in 2016 ieee wireless power transfer conference (wptc), 2016, vol. 2, no. 3, pp. 1–3. [4] w. chen, r.a. chinga, s. yoshida, j. lin, c. chen, and w. lo, “a 25.6 w 13.56 mhz wireless power transfer system with a 94% efficiency gan class-e power amplifier,” ieee mtt-s int. microw. symp. dig., pp. 25–27, 2012. [5] b.h. choi, d.t. nguyen, s.j. yoo, j.h. kim, and c.t. rim, “a novel source-side monitored capacitive power transfer system for contactless mobile charger using class-e converter,” in 2014 ieee 79th vehicular technology conference (vtc spring), 2014, no. january, pp. 1–5. [6] h. oh et al., “6.78 mhz wireless power transmitter based on a reconfigurable class-e power amplifier for multiple device charging,” ieee trans. power electron., vol. 35, no. 6, pp. 5907–5917, 2020. [7] u.g. choi and j.r. yang, “a 120 w class-e power module with an adaptive power combiner for a 6.78 mhz wireless power transfer system,” energies, vol. 11, no. 8, p. 2083, aug. 2018. [8] d. rattanarungngam, k. phaebua, and t. lertwiriyaprapa, “power control unit for e-class power oscillator of 6.78 mhz wireless power transfer,” in 2017 international symposium on antennas and propagation (isap), 2017, no. 1, pp. 1–2. [9] a. muharam, t. m. mostafa, and r. hattori, “design of power receiving side in wireless charging system for uav application,” in 2017 international conference on sustainable energy engineering and application (icseea), 2017, pp. 133–139. [10] k. agarwal, r. jegadeesan, y. x. guo, and n. v. thakor, “wireless power transfer strategies for implantable bioelectronics,” ieee reviews in biomedical engineering. 2017. [11] r. narayanamoorthi, a. vimala juliet, c. bharatiraja, s. padmanaban, and z.m. leonowicz, “class e power amplifier design and optimization for the capacitive coupled wireless power transfer system in biomedical implants,” energies, vol. 10, no. 9, 2017. [12] t.m. mostafa, a. muharam, and r. hattori, “wireless battery charging system for drones via capacitive power transfer,” in 2017 ieee pels workshop on emerging technologies: wireless power transfer (wow), 2017, vol. 3, no. 1, pp. 1–6. [13] c. park, j. park, y. shin, s. huh, j. kim, and s. ahn, “separated circular capacitive couplers for rotational misalignment of drones,” in 2019 ieee wireless power transfer conference (wptc), 2019, pp. 635–638. [14] a. muharam, t.m. mostafa, a. nugroho, a. hapid, and r. hattori, “a single-wire method of coupling interface in capacitive power transfer for electric vehicle wireless charging system,” in 2018 international conference on sustainable energy engineering and application (icseea), 2018, pp. 39–43. [15] v.b. vu et al., “a multi-output capacitive charger for electric vehicles,” in 2017 ieee 26th international symposium on industrial electronics (isie), 2017, pp. 565–569. [16] shuangke liu, ming liu, m. fu, c. ma, and x. zhu, “a highefficiency class-e power amplifier with wide-range load in wpt systems,” in 2015 ieee wireless power transfer conference (wptc), 2015, vol. 1, no. 3, pp. 1–3. [17] k.h. yi, “6.78 mhz capacitive coupling wireless power transfer system,” j. power electron., vol. 15, no. 4, pp. 987– 993, 2015. [18] y. yusop et al., “a study of capacitive power transfer using class-e resonant inverter,” asian j. sci. res., vol. 9, no. 5, pp. 258–265, 2016. [19] j. song, m. liu, and c. ma, “analysis and design of a highefficiency 6.78-mhz wireless power transfer system with scalable number of receivers,” ieee trans. ind. electron., vol. 0046, no. c, pp. 1–1, 2019. [20] m.a. de rooij, wireless power handbook; a supplement to gan transistors for efficient power conversion, second edi. power conversion publications, 2015. https://doi.org/10.1109/jssc.1975.1050582 https://doi.org/10.1109/jssc.1975.1050582 https://doi.org/10.1109/jssc.1975.1050582 https://doi.org/10.1109/jssc.1975.1050582 http://people.physics.anu.edu.au/~dxt103/160m/class_e_amplifier_design.pdf http://people.physics.anu.edu.au/~dxt103/160m/class_e_amplifier_design.pdf https://doi.org/10.1109/wpt.2016.7498801 https://doi.org/10.1109/wpt.2016.7498801 https://doi.org/10.1109/wpt.2016.7498801 https://doi.org/10.1109/wpt.2016.7498801 https://doi.org/10.1109/mwsym.2012.6258349 https://doi.org/10.1109/mwsym.2012.6258349 https://doi.org/10.1109/mwsym.2012.6258349 https://doi.org/10.1109/mwsym.2012.6258349 https://doi.org/10.1109/vtcspring.2014.7023151 https://doi.org/10.1109/vtcspring.2014.7023151 https://doi.org/10.1109/vtcspring.2014.7023151 https://doi.org/10.1109/vtcspring.2014.7023151 https://doi.org/10.1109/vtcspring.2014.7023151 https://doi.org/10.1109/tpel.2019.2953719 https://doi.org/10.1109/tpel.2019.2953719 https://doi.org/10.1109/tpel.2019.2953719 https://doi.org/10.1109/tpel.2019.2953719 https://doi.org/10.3390/en11082083 https://doi.org/10.3390/en11082083 https://doi.org/10.3390/en11082083 https://doi.org/10.1109/isanp.2017.8228830 https://doi.org/10.1109/isanp.2017.8228830 https://doi.org/10.1109/isanp.2017.8228830 https://doi.org/10.1109/isanp.2017.8228830 https://doi.org/10.1109/icseea.2017.8267698 https://doi.org/10.1109/icseea.2017.8267698 https://doi.org/10.1109/icseea.2017.8267698 https://doi.org/10.1109/icseea.2017.8267698 https://doi.org/10.1109/rbme.2017.2683520 https://doi.org/10.1109/rbme.2017.2683520 https://doi.org/10.1109/rbme.2017.2683520 https://doi.org/10.3390/en10091409 https://doi.org/10.3390/en10091409 https://doi.org/10.3390/en10091409 https://doi.org/10.3390/en10091409 https://doi.org/10.3390/en10091409 https://doi.org/10.1109/wow.2017.7959357 https://doi.org/10.1109/wow.2017.7959357 https://doi.org/10.1109/wow.2017.7959357 https://doi.org/10.1109/wow.2017.7959357 https://doi.org/10.1109/wptc45513.2019.9055550 https://doi.org/10.1109/wptc45513.2019.9055550 https://doi.org/10.1109/wptc45513.2019.9055550 https://doi.org/10.1109/wptc45513.2019.9055550 https://doi.org/10.1109/icseea.2018.8627079 https://doi.org/10.1109/icseea.2018.8627079 https://doi.org/10.1109/icseea.2018.8627079 https://doi.org/10.1109/icseea.2018.8627079 https://doi.org/10.1109/icseea.2018.8627079 https://doi.org/10.1109/isie.2017.8001308 https://doi.org/10.1109/isie.2017.8001308 https://doi.org/10.1109/isie.2017.8001308 https://doi.org/10.1109/wpt.2015.7140140 https://doi.org/10.1109/wpt.2015.7140140 https://doi.org/10.1109/wpt.2015.7140140 https://doi.org/10.1109/wpt.2015.7140140 https://doi.org/10.6113/jpe.2015.15.4.987 https://doi.org/10.6113/jpe.2015.15.4.987 https://doi.org/10.6113/jpe.2015.15.4.987 https://doi.org/10.6113/jpe.2016.16.5.1678 https://doi.org/10.6113/jpe.2016.16.5.1678 https://doi.org/10.6113/jpe.2016.16.5.1678 https://doi.org/10.1109/tie.2019.2950850 https://doi.org/10.1109/tie.2019.2950850 https://doi.org/10.1109/tie.2019.2950850 https://doi.org/10.1109/tie.2019.2950850 https://epc-co.com/epc/products/publications/wirelesspowerhandbook.aspx https://epc-co.com/epc/products/publications/wirelesspowerhandbook.aspx https://epc-co.com/epc/products/publications/wirelesspowerhandbook.aspx introduction ii. materials and methods a. proposed class-e rf power amplifier b. parallel load network specification c. impedance matching d. power and efficiency iii. results and discussions a. gate driver’s signal oscillation characteristics b. drain voltage characteristics load voltage characteristics d. power and efficiency characteristics iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.111-116 2088-6985 / 2087-3379 ©2020 research center for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables adi waskito a, *, rendra dwi firmansyah a, djohar syamsi a, catur hilman adritya haryo bhakti baskoro b, anisya lisdiana c, herkuswyna isnaniyah wahab c a technical implementation unit for instrumentation development, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 30, bandung 40135, indonesia b research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 20, bandung 40135, indonesia c research centre for geotechnology, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 70, bandung 40135, indonesia received 3 november 2020; accepted 17 november 2020; published online 22 december 2020 abstract ozonizer is a method used for sterilization and food preservation by utilizing ozone produced from plasma discharge. the effective way of obtaining ozone is to use dielectric barrier discharge (dbd) plasma. the manufacture of a controlled ozonizer chamber system is important to result in effective and efficient performance. the aim of this study is to design and optimize the ozone chamber parameter using pulse width modulation (pwm). the system design is added with the arduino mega 2560 microcontroller and the l296n motor driver as an ozone generator radiation controller by changing the pulse width modulation to determine the ozone levels produced. the experimental results show that the ozone concentration increases by 50 % on average with increasing variations of the 10 % duty cycle (pwm) and the ignition time length. the optimum value is achieved on a 70 % duty cycle for 60 300 seconds, where the ozone level of 3 ppm is obtained and sustained for fruits/vegetables sterilization and preservation application. ©2020 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: dielectric barrier discharge; ozone chamber; pulse width modulation; sterilization and preservation. i. introduction ozone gas (o3) is a strong oxidizing agent used in many sector applications such as medical and pharmaceutical, agriculture, food industry, water purification, waste treatment, and other industrialenvironmental management. the common method used for ozone generation in industrial area uses the dielectric barrier discharge (dbd), consisting of two parallel electrodes connected to an ac power supply separated by layers of dielectric material. the method principle is a voltage applied between the two electrodes to ionize the oxygen-containing gas to form ozone. the generating ozone is based on spreading oxygen molecules with control of suitable voltage and frequency [1][2][3]. the dbd chamber is subjected to a voltage across the electrodes. the energy is supplied for the micro discharges, where oxygen molecules break into a single atom and combine with other oxygen molecules to form ozone. the advantage of using a lower applied voltage is the opportunity to have ozone generators using nonconventional dielectric materials that have much lower dielectric breakdown voltage, such as mica, alumina ceramic, thin enamel, and polymer layers materials [4]. ozone production using dbd is affected by several factors such as voltage, electrical characteristics, flow rate, power supply and consumption, power modulation, and pulse polarity. the discharge conditions, such as gap-width, electrode material and surface, and applied voltage waveform, affect the system efficiency. the employment of pulse waveform as the applied voltage is expected to emphasize the highly * corresponding author. tel: +62-22-2503053 e-mail address: adiw002@lipi.go.id; otiksawida@gmail.com https://dx.doi.org/10.14203/j.mev.2020.v11.111-116 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.111-116 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.111-116&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ a. waskito et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 112 distorted high electric field and reduce the loss in the dielectric barrier [5][6]. the ozone production by pulsed electric fields is preferred due to shorter processing times that lead to considerable saving cost, leaves no hazardous residues, and less thermal side effects. no heat requires and hence saves energy. high voltage pulse generation can increase efficiency on the ozone generator. the switch in the pulse generator circuits only turned on typically in less than 10 % of a period, which is called the duty cycle. it can be off for the rest of the time, reducing energy consumption and limiting the electrode system’s heating [7]. the duty cycle variation is a simple tool to develop a practical ozone generator with widely adjustable ozone concentration and simultaneously constant ozone yield [8][9]. the food processing industry continuously improves food quality and safety, mainly related to microbial food safety concerns. hence, various food sterilization and preservation methods to prevent microbial contamination and maintain food product quality have been evaluated. ozone is a suitable choice for food sterilization and preservation because it has strong oxidative characteristics that make it an effective anti-microbial agent [10][11][12]. it destroys different types of microorganisms at relatively low concentrations. ozone can rapidly be decomposed and can oxidize organic substances into safer elements, leaving no hazardous compounds in the food products. the use of ozone is an energy-saving model as the energy input required for ozone treatment is lower than other treatments, such as thermal, radiation, and microwave. ozone could be generated on-site using ozone generators with oxygen as the gas source. therefore it meets the global demand for sustainability. some combination application of ozonation with other methods, i.e., pasteurization, freezing, high-pressure processing, uv, or membrane technology can be very effective in microbial inhibition and shelf life extension of food products [13][14][15]. combination treatments of ozone, chlorine dioxide, and ultrasound could be used for strawberry preservation to prolong the shelf life. it was found more beneficial for quality factors, such as ph, total soluble solids, texture, sugar content, and water content [16]. ozone and uv c disinfection methods for tomatoes, carrots, and lettuces were evaluated and found effective for the inactivation of e. coli. the effectiveness of such methods was influenced by the dose of the agent, the exposure time, and the surface of the food product tested. a smooth surface allows an easier sanitization process, while it shows lower inactivation on the more porous and rough surface of the fruits/vegetables products. color changes can be controlled by optimizing the exposure time and disinfection agent concentration [17]. in this paper, ozone is generated using dbd with a plate-type reactor, with a variation of the duty cycle of pulse width modulation and reactor time duration. the generated ozone is then collected in the box equipped with an ozone meter sensor to determine its concentration. the optimization was performed to obtain the targeted ozone level. for further study, the ozone generation system’s optimum condition will be used for fruits/vegetables sterilization and preservation applications, i.e., pears, apples, berries, lettuces, and onions. ii. materials and methods the ozone room system in the experiment was carried out in a closed box measuring 60 cm x 40 cm x 40 cm to produce optimal work without any external disturbance factors such as wind and ambient temperature (figure 1). the first experiment measured the maximum ozone level produced by a commercial ozone generator with the rate of change levels and the ozone’s residence time in the chamber. the second experiment measures the amount of ozone produced over time changes determined using the pulse width modulation method (pwm). finally, the third experiment figure 1. design of the sterilization and preservation chamber a. waskito et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 113 measures the length of time required for the amount of ozone determined changes in pulse width modulation. a. sterilization and preservation chamber there are several methods of sterilization and preservation of foodstuffs. one of those is called an ozonation. ozone can be formed through the collision process produced by the dielectric barrier discharge (dbd) plasma reactor, as shown in figure 2. oxygen molecules undergo ionization, which is the process of releasing an atom or molecules from their bonds to oxygen ions, called the plasma condition. the ozone molecule is formed by the ionization process of oxygen gas [18]. oxygen is oxidized by colliding with an electron (e-). furthermore, oxygen reacts with atoms o and m in the particulate form where m is any non reactive species that can take up the energy release in reaction to stabilize o3. m is either o2 or n2 which are the major components in the atmosphere. o2 + e o+ o2 (1) o+o2  o3 + e (2) o2 +o+ m  o3 + m (3) figure 3 shows the block diagram of the ozonizer system which is equipped with a speed converter and time controller. it is designed using an arduino mega 2560 microcontroller to get the desired ozone concentration. the ozone generator consists of an ozone reactor, a high voltage generator (hv), a fan to suck air from outside into the chamber, and a cooling medium for the ozone reactor. sterilization and preservation system equipment is divided into three parts, namely the ozone generator to produce ozone gas, the pwm controller to control the pulse width of the ozone generator, and the chamber as the object container. the commercial ozone generator is a portable ceramic powered by 12 v dc input voltage that produces 2.5 kv ac output voltage, 450 ma working current, 6 w power, and 200 mg/h ozone output. the l296n motor driver module controls the ozone generator converter, boost converter (0 32 v) to change the output voltage by 14 v required by the motor driver module, gas ozone sensor, and a 12 v 5 a switching. b. ozone gas sensor in this experiment, a semiconductor gas sensor (mq-131) that can read the range of 10-1000 ppm is used to measure the ozone gas concentration. this sensor work system requires an input voltage of 5v dc and a heating time of 48 hours before use to get the sensitivity of the response to the correct reading and is calibrated with an ozone meter (bh-90a) to ensure that the reading is accurate along with any changes in the levels of ozone gas produced. c. pulse width modulation (pwm) the modulation technique is applied by changing the pulse width (duty cycle) with a fixed amplitude and frequency. this experiment uses arduino mega 2560 as an l296n motor driver of a pulse width control module to control the ozone generator radiation to determine the amount of ozone concentration produced. this study used a randomized block design in taking the sample data to characterize the chamber design; each treatment combination was repeated three times. the treatment control consists of adjusting the pulse width of 10 % – 100 % with the duration of the ozone generator is varied from 60 to 300 seconds. the time rate results are obtained with the variation of the ozone concentration is set at 1 3 ppm. iii. results and discussions the experiment was done to determine the maximum working capacity of the ozone generator for 30 minutes. figure 4 shows that within 20 minutes of observation, the optimal value is obtained after 9 minutes. there is no change in the ozone level produced in the remaining observation time. initially, the ozone produced reaches the figure 2. dielectric barrier discharge plasma actuator figure 3. block diagram of the ozonizer system a. waskito et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 114 optimal value of 4.4 ppm for a short moment, then decreases and increases back into the optimal value as shown in the figure. the results obtained in the first minute are related to the characteristics of the ozone generator used. these results show that the ozone generator used is sufficient for sterilization and food preservation. figure 5 shows the rate of reduction in ozone gas levels and the residence time in the chamber when the engine is turned off, starting from 3 ppm as the maximum safe limit for food preservation. industrial-scale use of ozone at 3 ppm concentration in the storage of onions, potatoes, and sugar beets remarkably inhibited bacterial and mold count without compromising the biochemical composition and sensory quality [13]. ozone (3 ppm) treatment demonstrates effective inactivation of e. coli and l. monocytogenes on apples, lettuce, strawberries, and cantaloupe. both pathogens were remaining undetectable during 9 days of storage at 4°c [19]. the water bubbled with ozone at 3 ppm was found as the efficient treatment for removing fungicides residue and improving the storage quality of tomato [20]. the duration from the ozone stayed until lost in the chamber for 3 ppm concentration is 62 minutes 28 seconds. meanwhile, the time to maintain a 3 ppm level is only 2 minutes 4 seconds after the concentration rate decreases until it disappears. the amount of ozone concentration was controlled using pulse width modulation (pwm). figure 6 shows a graph of the pwm duty cycle of 10 %, 50 %, 80 %, with the motor driver voltage of 14 volts, where the voltage per division is 5 volts. the results obtained from the oscilloscope observation show that the pwm signal control is appropriate based on the voltage graph according to the amount of the duty cycle used. the pwm control with a change in the duty cycle of 10 % 100 % for 60 to 300 seconds was shown in figure 7. it can be seen from the graph that the higher the percentage of the duty cycle used, the ozone levels and the efficiency value of the pwm percent control increase. the optimum of the duty figure 4. plot of the ozone generator performance figure 5. plot of ozone residence time and decline rate in the chamber figure 6. pwm signal graph a. waskito et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 115 cycle was found at 70 %, where the ozone level of 3 ppm is obtained and sustained. in observations during the experiment on the length of the ignition time with a duty cycle of 10 % 80 %, the ozone level experienced an increased rate when showing the ignition time of 60 120 seconds, while when entering the ignition time of 130 300 seconds, the ozone level obtained was constant. however, when the duty cycle treatment is 90 % 100 %, the ozone levels fluctuate, wherein the initial 60 seconds the rate increases, then at 100 300 seconds, the rate decreases until it becomes constant. it is most likely influenced by the characteristics of the ozone generator used. the duration to reach a predetermined ozone level was measured with ozone level variation 1 3 ppm. figure 8 shows that the greater the percentage of duty cycle used, the faster the time required to reach the predetermined ozone level. it was also revealed that when the ozone generator’s set-point was set to 1 ppm, the 10 % duty cycle was unable to reach the set-point value even with infinite ignition figure 7. graph of ozone production based on duty cycle and time figure 8. graph of the ozone time requirements a. waskito et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 111-116 116 time. furthermore, when the set-point is increased by 2 ppm, the duty cycle of 10 % 30 % is unable to achieve it. then, when it is increased by 3 ppm, the duty cycle of 10 % 50 % could not achieve it. it can be concluded that the greater the specified ozone level, the smaller range of the duty cycle allowed. iv. conclusion the ozonizer chamber is designed based on pulse width modulation using a high voltage dc ozone generator. optimization of the ozone chamber system was performed to obtain an effective and efficient performance. the experimental results show that increasing 10 % duty cycle variation affects the generated ozone concentration by 50 % on average. the optimum value was achieved on a 70 % duty cycle for 60 300 seconds, where 3 ppm ozone level is obtained and sustained for fruits/vegetables sterilization and preservation applications. acknowledgement this work was supported by the national priority program, deputy of scientific services, indonesian institute of sciences. declarations author contribution all authors contributed correspondingly as the main contributor to this paper. all authors read and endorsed the final paper. funding statement this research did not receive any particular grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] y. chen and z. wang, “soft-switched technology for ozone generator based on capacitive phase shift control,” proc. 2019 ieee 3rd adv. inf. manag. commun. electron. autom. control conf. imcec 2019, pp. 219–222, 2019. [2] s. ketkaew, “development of corona ozonizer using high voltage controlling of produce ozone gas for cleaning in cage,” mod. environ. sci. eng., vol. 3, no. 7, pp. 505–509, 2017. [3] m. ponce-silva, j. a. aqui, v. h. olivares-peregrino, and m. a. oliver-salazar, “assessment of the current-source, full-bridge inverter as power supply for ozone generators with high power factor in a single stage,” ieee trans. power electron., vol. 31, no. 12, pp. 8195–8204, 2016. [4] m. facta, hermawan, karnoto, z. salam, and z. buntat, “double dielectric barrier discharge chamber for ozone generation,” 2014 1st int. conf. inf. technol. comput. electr. eng. green technol. its appl. a better futur. icitacee 2014 proc., vol. i, pp. 409–412, 2015. [5] t. miura, t. sato, k. arima, s. mukaigawa, k. takaki, and t. fujiwara, “duty factor effect on ozone production using dielectric barrier discharge reactor driven by igbt pulse modulator,” j. adv. oxid. technol., vol. 10, no. 2, pp. 311–315, 2007. [6] e. yulianto et al., “effect of duty cycle on ozone production using dbdp cylindrical reactor,” j. phys. conf. ser., vol. 1217, no. 1, 2019. [7] p. p. abkenar, h. iman-eini, m. h. samimi, and m. emaneini, “design and implementation of ozone production power supply for the application of microbial purification of water,” ieee trans. power electron., vol. 35, no. 8, pp. 8215–8223, 2020. [8] r. barni, i. biganzoli, e. c. dell’orto, and c. riccardi, “effect of duty-cycles on the air plasma gas-phase of dielectric barrier discharges,” j. appl. phys., vol. 118, no. 14, p. 143301, 2015. [9] y. f. zhang, l. s. wei, x. liang, h. z. deng, and m. šimek, “characteristics of the discharge and ozone generation in oxygen-fed coaxial dbd using an amplitude-modulated ac power supply,” plasma chem. plasma process., vol. 38, no. 6, pp. 1199–1208, 2018. [10] t. bhilwadikar, s. pounraj, s. manivannan, n. k. rastogi, and p. s. negi, “decontamination of microorganisms and pesticides from fresh fruits and vegetables: a comprehensive review from common household processes to modern techniques,” compr. rev. food sci. food saf., vol. 18, pp. 1003–1038, 2019. [11] m. glowacz and d. rees, “the practicality of using ozone with fruit and vegetables,” j. sci. food agric., vol. 96, no. 14, pp. 4637–4643, 2016. [12] m. aziz and s. karboune, “natural antimicrobial/antioxidant agents in meat and poultry products as well as fruits and vegetables: a review,” crit. rev. food sci. nutr., vol. 58, no. 3, pp. 486–511, 2018. [13] r. pandiselvam, s. subhashini, e. p. banuu priya, a. kothakota, s. v. ramesh, and s. shahir, “ozone based food preservation: a promising green technology for enhanced food safety,” ozone sci. eng., vol. 41, no. 1, pp. 17–34, 2019. [14] h. nakamura, m. oya, t. hanamoto, and d. nagashio, “reviewing the 20 years of operation of ozonation facilities in hanshin water supply authority with respect to water quality improvements,” ozone sci. eng., vol. 39, no. 6, pp. 397–406, 2017. [15] m. a. khadre, a. e. yousef, and j. g. kim, “microbiological aspects of ozone applications in food: a review,” j. food sci., vol. 66, no. 9, pp. 1242–1252, 2001. [16] m. s. aday and c. caner, individual and combined effects of ultrasound, ozone and chlorine dioxide on strawberry storage life, vol. 57, no. 1. elsevier ltd, 2014. [17] d. bermúdez-aguirre and g. v. barbosa-cánovas, “disinfection of selected vegetables under nonthermal treatments: chlorine, acid citric, ultraviolet light and ozone,” food control, vol. 29, no. 1, pp. 82–90, 2013. [18] d. n. meivita, m. rivai, and a. n. irfansyah, “development of an electrostatic air filtration system using fuzzy logic control,” int. j. adv. sci. eng. inf. technol., vol. 8, no. 4, pp. 1284–1289, 2018. [19] s. l. rodgers, j. n. cash, m. siddiq, and e. t. ryser, “a comparison of different chemical sanitizers for inactivating escherichia coli o157:h7 and listeria monocytogenes in solution and on apples, lettuce, strawberries, and cantaloupe,” j. food prot., vol. 67, no. 4, pp. 721–731, 2004. [20] a. a. z. rodrigues et al., “use of ozone and detergent for removal of pesticides and improving storage quality of tomato,” food res. int., vol. 125, p. 108626, 2019. https://doi.org/10.1109/imcec46724.2019.8983853 https://doi.org/10.1109/imcec46724.2019.8983853 https://doi.org/10.1109/imcec46724.2019.8983853 https://doi.org/10.1109/imcec46724.2019.8983853 https://doi.org/10.15341/mese(2333-2581)/07.03.2017/011 https://doi.org/10.15341/mese(2333-2581)/07.03.2017/011 https://doi.org/10.15341/mese(2333-2581)/07.03.2017/011 https://doi.org/10.1109/tpel.2016.2520925 https://doi.org/10.1109/tpel.2016.2520925 https://doi.org/10.1109/tpel.2016.2520925 https://doi.org/10.1109/tpel.2016.2520925 https://doi.org/10.1109/tpel.2016.2520925 https://doi.org/10.1109/icitacee.2014.7065781 https://doi.org/10.1109/icitacee.2014.7065781 https://doi.org/10.1109/icitacee.2014.7065781 https://doi.org/10.1109/icitacee.2014.7065781 https://doi.org/10.1109/icitacee.2014.7065781 https://doi.org/10.1515/jaots-2007-0213 https://doi.org/10.1515/jaots-2007-0213 https://doi.org/10.1515/jaots-2007-0213 https://doi.org/10.1515/jaots-2007-0213 https://doi.org/10.1515/jaots-2007-0213 https://doi.org/10.1088/1742-6596/1217/1/012011 https://doi.org/10.1088/1742-6596/1217/1/012011 https://doi.org/10.1088/1742-6596/1217/1/012011 https://doi.org/10.1109/tpel.2019.2962972 https://doi.org/10.1109/tpel.2019.2962972 https://doi.org/10.1109/tpel.2019.2962972 https://doi.org/10.1109/tpel.2019.2962972 https://doi.org/10.1109/tpel.2019.2962972 https://doi.org/10.1063/1.4933047 https://doi.org/10.1063/1.4933047 https://doi.org/10.1063/1.4933047 https://doi.org/10.1007/s11090-018-9922-2 https://doi.org/10.1007/s11090-018-9922-2 https://doi.org/10.1007/s11090-018-9922-2 https://doi.org/10.1007/s11090-018-9922-2 https://doi.org/10.1007/s11090-018-9922-2 https://doi.org/10.1111/1541-4337.12453 https://doi.org/10.1111/1541-4337.12453 https://doi.org/10.1111/1541-4337.12453 https://doi.org/10.1111/1541-4337.12453 https://doi.org/10.1111/1541-4337.12453 https://doi.org/10.1002/jsfa.7763 https://doi.org/10.1002/jsfa.7763 https://doi.org/10.1002/jsfa.7763 https://doi.org/10.1080/10408398.2016.1194256 https://doi.org/10.1080/10408398.2016.1194256 https://doi.org/10.1080/10408398.2016.1194256 https://doi.org/10.1080/10408398.2016.1194256 https://doi.org/10.1080/01919512.2018.1490636 https://doi.org/10.1080/01919512.2018.1490636 https://doi.org/10.1080/01919512.2018.1490636 https://doi.org/10.1080/01919512.2018.1490636 https://doi.org/10.1080/01919512.2017.1352413 https://doi.org/10.1080/01919512.2017.1352413 https://doi.org/10.1080/01919512.2017.1352413 https://doi.org/10.1080/01919512.2017.1352413 https://doi.org/10.1080/01919512.2017.1352413 https://doi.org/10.1111/j.1365-2621.2001.tb15196.x https://doi.org/10.1111/j.1365-2621.2001.tb15196.x https://doi.org/10.1111/j.1365-2621.2001.tb15196.x https://doi.org/10.1016/j.lwt.2014.01.006 https://doi.org/10.1016/j.lwt.2014.01.006 https://doi.org/10.1016/j.lwt.2014.01.006 https://doi.org/10.1016/j.foodcont.2012.05.073 https://doi.org/10.1016/j.foodcont.2012.05.073 https://doi.org/10.1016/j.foodcont.2012.05.073 https://doi.org/10.1016/j.foodcont.2012.05.073 http://dx.doi.org/10.18517/ijaseit.8.4.6512 http://dx.doi.org/10.18517/ijaseit.8.4.6512 http://dx.doi.org/10.18517/ijaseit.8.4.6512 http://dx.doi.org/10.18517/ijaseit.8.4.6512 https://doi.org/10.4315/0362-028x-67.4.721 https://doi.org/10.4315/0362-028x-67.4.721 https://doi.org/10.4315/0362-028x-67.4.721 https://doi.org/10.4315/0362-028x-67.4.721 https://doi.org/10.4315/0362-028x-67.4.721 https://doi.org/10.1016/j.foodres.2019.108626 https://doi.org/10.1016/j.foodres.2019.108626 https://doi.org/10.1016/j.foodres.2019.108626 i. introduction ii. materials and methods a. sterilization and preservation chamber b. ozone gas sensor c. pulse width modulation (pwm) iii. results and discussions iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references microsoft word vol03_no1_vcetak mechatronics, electrical power, and vehicular technology 03 (2012) 17-22 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved development of discrete power supply with charge pump method for high powered sonar system rancang bangun catu daya diskrit dengan metode charge pump untuk sistem sonar berdaya tinggi kristian ismail a,*, syamsu ismail b a pusat penelitian tenaga listrik dan mekatronik lipi kompleks lipi jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia b pusat penelitian elektronika dan telekomunikasi lipi kompleks lipi jl sangkuriang, gd 20, lt 4, bandung, jawa barat 40135, indonesia received 30 april 2012; received in revised form 6 july 2012; accepted 9 july 2012 published online 31 july 2012 abstract power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. there are several types of power supplies that can be applied depend on the requirement and functions. one example is the use of power supply for sonar systems. sonar system is a device which can be used to detect a target under water. the sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on) and the specific lag time (when off). this paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. charge pump was used to get the appropriate output voltage from lower input voltage. charge pump utilized a combination of series and parallel connections of capacitors. the working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series. key words: power supply, charge pump, discrete method. abstrak catu daya adalah salah satu perangkat elektronika yang dapat menyediakan energi listrik untuk sistem elektronika atau sistem lainnya. terdapat beberapa jenis catu daya yang dapat diaplikasikan sesuai dengan kebutuhan dan fungsinya, salah satu contohnya adalah penggunaan catu daya untuk sistem sonar. sistem sonar adalah alat pendeteksi keberadaan target di bawah air, sistem tersebut berupa rangkaian elektronika yang memerlukan catu daya dengan karakteristik yang spesifik. catu daya dibutuhkan pada saat sonar sebagai pemancar dan sebagai penerima dalam rentang waktu (saat on) dan jeda waktu (saat off) yang spesifik. untuk memenuhi karakteristik dan spesifikasi tersebut, maka digunakan catu daya diskrit yang menggunakan metode charge pump untuk mengumpulkan energi listriknya. dalam tulisan ini dibahas tentang rancang bangun catu daya yang digunakan untuk menyediakan energi listrik bagi sistem sonar berdaya tinggi dengan metoda diskrit yaitu pengaktifan catu daya tinggi tidak kontinyu melainkan hanya pada saat gelombang akustik diradiasikan di bawah air. metoda pengumpulan energi ke komponen pengubah tegangan menggunakan charge pump. charge pump pada catu daya yang dikembangkan ini memanfaatkan kombinasi hubungan seri dan paralel kapasitor. cara kerja catu daya ini menggunakan jeda waktu sebagai perhitungan waktu untuk pengisisan kapasitor charge pump secara paralel sedangkan rentang waktu digunakan untuk perhitungan pengosongan kapasitor charge pump secara seri. kata kunci: catu daya, charge pump, metode diskrit. i. pendahuluan negara kesatuan republik indonesia terdiri dari sekitar 17 ribu pulau dengan dua per tiga luas wilayahnya berupa lautan. sistem komunikasi saat ini umumnya menggunakan media fisik seperti kabel tembaga, serat optik, dan gelombang radio. populasi pengguna gelombang radio sudah demikian padat sehingga pemanfaatan medium lain seperti air akan mengurangi kepadatan pengguna frekuensi radio. oleh karena itu, teknologi elektronika bawah air * corresponding author. tel: +62-22-2503055 e-mail: ksansan@yahoo.com k. ismail et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 17-22 18 untuk beberapa kepentingan seperti sistem komunikasi, sistem sonar, sistem pengamanan, eksplorasi kekayaan bawah air, dan kepentingan lainnya merupakan suatu kebutuhan yang tidak dapat diabaikan [1]. sonar adalah sebuah piranti untuk mengamati (mendeteksi dan menyidik) keberadaan dan lokasi benda di bawah permukaan air dengan menggunakan gelombang suara yang dikirim dari peranti dan dipantulkan kembali oleh benda (objek) yang diamati [4]. sinyal akustik untuk sistem sonar berpropagasi di dalam suatu medium (air) dengan cara menekan dan menarik partikel air [2]. sumber energi listrik untuk sonar tersebut berasal dari sebuah catu daya. catu daya sonar pada saat ini menggunakan catu daya kontinyu [3], artinya ketika catu daya tidak melayani beban, tegangan tetap tersedia walaupun arus tidak mengalir. kondisi tersebut tidak menambah akumulasi daya keluaran tetapi menambah berat dan fisik catu daya. ketika sistem sonar diperlukan untuk kebutuhan militer, sistem catu daya sonar kontinyu sulit untuk diterapkan karena sistem tersebut tidak menyediakan sistem yang kompak dan mudah dibawa. perancangan catu daya diskrit menjadi lebih ringan karena menggunakan kapasitor sebagai pengonversi tegangan (pada catu daya kontinyu menggunakan trafo). namun pada perancangan catu daya diskrit terdapat kerumitan dalam menentukan waktu (timing) kapan melayani beban dan berapa lama waktu untuk pengisian ulang. tujuan dari tulisan ini adalah membuat catu daya untuk sistem sonar yang bekerja secara diskrit (dalam interval waktu tertentu) dimana akan dilakukan proses perhitungan daya untuk waktu pengosongan dan waktu pengisian pada catu daya sesuai dengan spesifikasi yang dibutuhkan. ii. catu daya untuk sonar catu daya adalah salah satu perangkat elektronika yang dapat menyediakan energi listrik untuk sistem elektronika atau sistem gambar 1. catu daya sonar. lainnya. gambar 1 merupakan contoh dari catu daya sonar. catu daya jenis diskrit ditandai dengan penggunaan piranti semikonduktor yang berfungsi sebakai saklar. catu daya sonar membutuhkan daya yang besar untuk mengirimkan gelombang suara di bawah air [3]. dalam perancangan catu daya diskrit beberapa hal perlu diperhatikan yaitu besar beban daya yang dilayani, frekuensi kerja dan rentang tegangan yang dibutuhkan. untuk daya dan tegangan catu daya sonar dapat dilihat pada spesifikasi transducer sedangkan untuk frekuensi kerja catu daya didapat dari waktu on dan waktu off sistem sonar. iii. metodologi pada perencanaan ini, metodologi dibagi menjadi beberapa tahap yaitu; pertama adalah identifikasi permintaan sistem, dimana pada tahap ini diidentifikasi karakteristik beban, media komunikasi, dan jarak komunikasi. selanjutnya adalah tahap perhitungan sumber daya dimana pada tahap ini dilakukan perhitungan sumber daya asal dan sumber daya yang akan diinputkan ke sistem. setelah itu dilanjutkan dengan tahap perhitungan kapasitor, dimana dilakukan perhitungan pengisian kapasitor yang dihubung secara parallel dan perhitungan pengosongan kapasitor yang dihubung secara seri. tahap yang paling akhir adalah perencanaan charge pump, pada tahap ini penentuan hubungan dan jumlah kapasitor untuk charge pump. perencanaan rangkaian pembangkit pulsa, pada tahap ini dilakukan perencanaan untuk mendapatkan pulsa sebagai penyulut hubungan kapasitor. pulsa yang dihasilkan akan dijadikan sebagai timing untuk hubungan seri dan parallel pada kapasitor charge pump. a. permintaan sistem pada catu daya untuk sistem sonar perlu diperhatikan kebutuhan sistem seperti karakteristik pembebanan atau media dan jarak komunikasi. transducer sebagai komponen gambar 2. konstruksi sebuah transduser [6]. k. ismail et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 17-22 19 gambar 3. grafik kecepatan transmisi pada air laut. pemancar (gambar 2) mempunyai karakteristik pembebanan sebagai berikut: • resistansi tranduser 100 ohm • tegangan kerja transducer tersebut berkisar antara 1.000 v sampai dengan 1.500 v • pembebanan transducer terhadap catu daya sebesar 10 kw selama 10 ms. catu daya yang direncanakan adalah untuk sistem sonar dengan kedalaman antara 100 meter sampai dengan 500 meter, kadar garam 10 %, dan jarak komunikasi pada perencanaan catu daya adalah 10 km. dari beberapa permintaan sistem di atas dapat dirancang waktu pengisian dan pengosongan kapasitor charge pump pada catu daya. dimana waktu minimal pengosongan kapasitor adalah 10 milidetik, didapat dari waktu pembebanan transducer. sedangkan waktu pengisian kapasitor didapat dengan melihat grafik kecepatan transmisi pada air laut di kedalaman 100 m sampai dengan 500 m (gambar 3). dari grafik didapat bahwa kecepatan transmisi adalah 1500 meter/detik [5]. waktu pengisian kapasitor dapat dihitung dengan persamaan berikut ini ton  = 10 km / 1.500 m = 6,7 detik  dimana ton adalah waktu pengisian, 10 km merupakan jarak komunikasi, dan 1500 m adalah kecepatan transmisi perdetik. b. blok diagram sistem gambar 4 menunjukan blok diagram dari sistem yang dirancang. pada blok diagram tersebut terlihat sumber daya utama adalah dari jala-jala listrik pln. sumber utama tersebut disearahkan dengan menggunakan penyearah satu fasa gelombang penuh. setelah didapat tegangan dc maka tegangan tersebut akan diregulasi oleh kapasitor charge pump. kapasitor tersebut dikontrol untuk menentukan kapan kapasitor diisi dan kapan kapasitor tersebut melayani beban. c. perhitungan sumber daya pada prinsipnya, sumber daya utama untuk alat yang direncanakan berasal dari jala-jala gambar 4 blok diagram sistem. listrik pln yang disearahkan. penyearahan dilakukan menggunakan dioda jembatan gelombang penuh. tegangan keluaran rata-rata adalah tegangan rata-rata yang keluar dari penyearah yang besarnya sama dengan dua kali tegangan maksimum dibagi dengan π seperti pada persamaan (1) [7]: vrms   = vm/√2 (1) vm   = √2 vrms   dari gambar 5 dan persamaan (1) didapat bahwa tegangan sumber yang diterima oleh catu daya adalah = √2 x 220 = 311,12 volt dc. tegangan sumber akan dikalikan empat menjadi 1.244,48 volt dc sesuai dengan spesifikasi tegangan beban yaitu 1.000 v sampai dengan 1.500 v. untuk mengalikan tegangan sumber menjadi empat maka dibutuhkan empat buah kapasitor. d. kapasitor charge pump kapasitor dapat dirangkai dengan beberapa kombinasi hubungan diantaranya hubungan seri, hubungan parallel, dan seri parallel. setiap kombinasi akan mendapatkan perbedaan nilai kapasitansinya [8]. untuk menghitung kapasitansi yang digunakan perlu dihitung terlebih dahulu energi yang diperlukan dalam pembebanan. energi didapat dari hasil perkalian daya beban dan waktu pembebanan. energi  = w x t (2) dengan w adalah daya beban dan t adalah waktu pembebanan, dapat disimpulkan bahwa energi yang diperlukan untuk mensuplai transducer selama transmisi 10 ms adalah = 10.000 x 10-2 = 100 watt det. harga kapasitansi minimum didapat dengan persamaan (3) dan (4): e=½ qv (3) q = c v (4) dimana e adalah energi, q adalah muatan, c adalah kapasitansi pengosongan, dan v adalah tegangan kerja minimum. ketika persamaan (3) dan persamaan (4) digabungkan maka harga beban ∞ sumber pln penyearah kapasitor charge pump kontrol pembangkit lebar pulsa k. ismail et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 17-22 20 gambar 5. rangkaian penyearah. kapasitansi minimum untuk catu daya komunikasi bawah air adalah: cp =   f cp   =   f = 0,0002 f = 200 µf  pada tulisan ini direncanakan menggunakan empat kapasitor dikarenakan teganan sumber dari pln akan dinaikkan empat kali lipat, namun pada saat proses pengosongan kapasitor harus tetap berkapasitansi 200 µf (kapasitor dihubung seri). kapasitor dihubung seri pada saat pengosongan/pembebanan sehingga kapasitansi setiap kapasitor dapat dihitung dengan persamaan (5) dan (6) [9]. (5) c1 = c2 = c3 = c3 = c4 = c (6) ketika persamaan (5) dan persamaan (6) digabungkan maka: 1 1 1 1 1 1 1 1 1 1 1 4 c = 4cp  sehingga: c = 4 x 200 µf = 800 µf dimana cp adalah kapasitor total pengosongan, dan c = c1 =  c2  =  c3  =  c4 adalah kapasitor charge pump. ilustrasi pengosongan kapasitor dapat dilihat pada gambar 6 dimana terlihat bahwa pada saat pembebanan, kapasitor charge pump hanya terhubung ke beban sedangkan catu daya utama dilepaskan dari kapasitor charge pump. pada saat pengisian, kapasitor dihubungkan parallel sehingga perhitungan kapasitansi total pada saat pengisian didapat dilakukan dengan persamaan (7) dan (6) : cs = c1 +c2+c3+c4 (7) gambar 6. pengosongan kapasitor pada saat pembebanan. ketika persamaan (7) dan persamaan (6) digabungkan, dimana cs adalah kapasitor total pengisian, maka cs = 4c = 4 x 800 µf = 3.200µf. ilustrasi pengisian kapasitor diperlihatkan pada gambar 7. pada gambar tersebut terlihat dimana pada saat pengisian kapasitor hanya terhubung ke catu daya utama, sedangkan ke bebannya diputus. dengan nilai kapasitansi 800 μf, maka ketika dihubung parallel, akan memiliki nilai kapasitansi sebesar 3.200 μf. sedangkan ketika dihubung seri akan memiliki nilai kapasitansi 200 μf. terlihat bahwa nilai kapasitansi ketika dihubung parallel berkisar enam belas kali lipat dibanding dengan nilai kapasitansi ketika kapasitor dihubung seri. namun ketika dihubung seri tegangan kerja dari kapasitor akan lebih tinggi empat kali lipat dibanding dengan tegangan kerja kapasitor ketika dihubung parallel. e. perhitungan kapasitor setelah diperoleh harga kapasitansi pada saat dihubung paralel dan pada saat dihubung seri, maka selanjutnya perlu dihitung tegangan akhir pada proses pengosongan dan tegangan akhir pada proses pengisian di waktu jeda. persamaan (8) menunjukkan konstanta waktu rc sedangkan persamaan (9) menunjukkan pengosongan kapasitor untuk perhitungan tegangan akhir pada proses pembebanan. τ = r ×c (8) vcab = voc (  /  ) (9) dimana : vcab = nilai akhir setelah pembebanan voc = nilai awal tegangan pada kapasitor e = nilai euler (2,7182818) t = waktu dalam satuan detik τ  = konstanta waktu persamaan (11) merupakan persamaan pengisian kapasitor untuk perhitugan tegangan akhir selama proses delay. vcap = vos ( 1 ­  /  ) (10) dimana vcap adalah nilai akhir setelah pengisian dan vos adalah nilai awal tegangan dari sumber. k. ismail et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 17-22 21 gambar 7. pengisian kapasitor charge pump. dari persamaan (9), pada saat pengosongan kapasitor terjadi penurunan tegangan secara eksponensial. penurunan tegangan selama pembebanan tidak boleh kurang dari spesifikasi beban. dari persamaan (8) dengan c = 200 µf dan resistansi tranduser r = 100 ohm, didapat τ = 0,0199. penurunan tegangan selama 10 ms pembebanan dapat dihitung dengan persamaan (9). dari hasil perhitungan menggunakan persamaan (9), di atas dimana ketika catu daya mengirimkan tegangan sebesar 1.244,48 v (311.12 v x 4) sesuai dengan permintaan beban selama 10 ms, akan terjadi penurunan tegangan menjadi = 1.244,48 , / , = 1.184.05 v, namun penurunan ini masih di dalam area tegangan kerja tranduser. dari persamaan (10) pada saat pengisian kapasitor terjadi penaikan tegangan secara eksponensial. penaikan tersebut harus diperhitungkan lama waktunya sehingga tegangan kapasitor tidak boleh kurang dari tegangan sumber. dari persamaan (8) dengan c = 3.200 µf dan resistansi tranduser r = 100 ohm, didapat τ = 0,32. penaikan tegangan selama 6,7 detik pengisian dapat dihitung menggunakan persamaan (10) vcap = 311,12 ( 1 , / , )= 311,12 (0,999)= 311,1199 v. dari hasil perhitungan di atas dapat disimpulkan bahwa tegangan pengisian mendekati tegangan sumber, dengan demikian pengisian kapasitor selama 6,7 detik cukup untuk mengisi kapasitor secara penuh. f. rangkaian kontrol pembangkit lebar pulsa rangkaian pembangkit pulsa untuk charge pump menggunakan rangkaian analog maupun gambar 8. rangkaian pembangkit pulsa. gambar 9. diagram blok mikrokontroler. digital (mikrokontroler). rangkaian pembangkit pulsa analog dapat menggunakan ic pwm sg3524. keluaran gelombang tegangan pwm sg3524 memiliki kemampuan untuk mengatur lebar pulsa serta mengatur frekuensi keluaran. lebar pulsa diatur melalui tegangan masukan kaki terminal in+, indan comp (gambar 8), tegangan masukan ini dapat diatur secara manual dengan variable resistor melalui terminal comp. frekuensi keluaran dapat diatur melalui rt  dan ct. dari datasheet, diperoleh persamaan (11) untuk menentukan frekuensi yaitu [10] :  f = 1.3/(rt∙ct) (11) dimana f adalah frekuensi kerja, rt adalah tahanan osilasi, dan ct adalah kapasitor osilasi selain menggunakan ic sg3524, pembangkitan pulsa juga dapat menggunakan rangkaian mikrokontroler. mikrokontroler dilengkapi dengan arithmetic and logic unit (alu) sehingga dapat digunakan untuk menangani perhitungan osilasi. oleh karena itu, pada rangkaian mikrokontroler tidak lagi perlu membuat rangkaian osilasi dikarenakan osilasi dapat dibangun secara perangkat lunak. seperti pada gambar 9, pembangkitan pulsa dapat dikeluarkan melalui port 0 sampai dengan port 3. sedangkan perhitungan waktu pada mikrokontroler dapat dibantu oleh register timer. gambar 10. rangkaian rancangan. 22 gam iv. has rangkai dilihat pada komponen paralel dan sakelar sing sakelar pa kapasitor ad posisi ‘baw paralel. ga keluaran p trigger untu timing ters gambar 12 kontrol catu pump untuk kapasitor 80 saat kapasit pengisian, k kapasitor d pembebanan melebihi da v. kesim dari beb beberapa ke ‐ catu d daya dis ‐ penaika kombin ke seri. ‐ kecepa rendah penerim dan kua ‐ dengan daya se dengan ucapan terima atas kese penelitian i sampaikan memberikan 1 k. ism mbar 11. bentuk sil dan pe an lengkap d a gambar 1 untuk meng seri direpre gle pole do ada posisi dalah seri, k wah’ maka hu ambar 11 m pada rangka uk kapasitor ebut sesuai d 2 merupaka u daya diskr k sistem sona 00 µf (hasil tor dihubung kapasitor dap dihubung ser n, tidak terj ari spesifikas mpulan berapa pema esimpulan: aya sonar d skrit dengan an tegangan nasi hubunga atan rambat mengakiba ma ditentuka at sinyal. n sistem yang esuai dengan dimensi dan terima k kasih kami empatan m ini. ucapan pada re n bantuan da mail et al. / mecha k gelombang ke embahas dari perancan 10. pada gam gubah hubun sentasikan d oble trow. k ‘atas’ mak ketika kontak ubungan kap menunjukkan aian penyul hubungan se dengan kebu an foto da rit dengan m ar berdaya ti l perhitungan g paralel den pat terisi pen ri dengan 1 jadi drop te i beban. aparan diatas dapat mengg charge pump dapat dilak an kapasitor gelombang atkan kualit an juga oleh g direncanak n kebutuhan n berat yang m kasih sampaikan p mempublika yang sama kan-rekan alam penelitia 1 atronics, electrica eluaran. an ngan ini dap mbar tersebu ngan kapasito dengan konta ketika konta ka hubunga k sakelar pad pasitor adala n gelomban lutan sebag eri dan paral utuhan sistem ari rangkaia metode charg inggi. denga n), maka pad ngan 6,7 deti nuh. pada sa 10 mili deti egangan yan s dapat ditari gunakan cat mp kukan denga r dari parall akustik yan tas informa waktu tund kan, diperole sistem namu minimum. pada penerb asikan has a ingin kam yang tela an ini. 6 al power, and ve at ut or ak ak an da ah ng ai el. m. an ge an da ik at ik ng ik tu an el ng asi da eh un bit sil mi ah ref [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] 1 ehicular technolo gam ferensi ismail sy komunikas akustik, l bandung : 2 urick j. ro sound, 3d company, n __________ systems an http://www upply.htm, b. sicilian springer ha 3-540-2395 fischer, f. acoustics, i york, lond ismail sya elemen t sistem ko elektronika 2, juli 2007 kasap, s.o material an company, t c-c. wan improvemen ieee journ no. 6 , pp.85 yuda, meng [online]. http://www tung-dan-m diakses tan _________, pulse width dallas, 201 ogy 03 (2012) 17mbar 12. foto r yamsu, pen si strategis m laporan pe 2008. obert, princi d edition new york : __,professio nd product .dflsystems.c diakses tang o, o. kha andbook of 57-4, 2008 . a, funda interscience don : 1955. amsu, deni ransduser p omunikasi b a dan teleko 7. o., “princip nd devices,” toronto: 200 ng and j-c nt in char nal of solid s 52-860 june ghitung dan .linksukses.c mengukur-kap nggal 5 juni 2 ,sg2524 sg h modulator 1 -22 rangkaian. ngembangan menggunaka enelitian pp iples of und mcgraw-hi 1983. onal e [online]. a co.uk/sonar_ ggal 4 juni 20 atib, sonar robotics. is amental of publisher, i i p., “kara piezoelektrik bawah air,” munikasi, v ples of el mcgraw-h 02. c. wu, “e rge pump state circuits 1997 mengukur k a com/2011/06 pasitor.html, 2012 g 3524 r rs, texas ins sistem an sinyal pet-lipi der water ill book electronic available: _power_s 012 sensing, sbn 978electroinc, new akterisasi k untuk ” jurnal vol. 7 no. lectronics hill book efficiency circuits,” s, vol. 32, kapasitor, available: 6/menghi 2011. egulating strument, mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.45-54 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system muhammad khristamto aditya wardana a, b, *, ocktaeck lim a a department of mechanical engineering, university of ulsan ulsan, 680-749, republic of korea b research centre for electrical power and mechatronics, indonesian institute of sciences komp. lipi bandung, gd 20, lt 2, bandung, west java, 40135 indonesia received 10 may 2020; accepted 16 may 2020; published online 30 july 2020 abstract diesel engines are commonly used for public transportation on-road and off-road applications. growth production of the diesel engine is very significant from year to year. nitride oxide (nox) from diesel engine was one of the major sources of air pollution. selective catalytic reduction (scr) has been successfully used to reduce nox from a diesel engine with a chemical reaction from ammonia (nh3). the mixing reaction between nox and nh3 reaction can produce steam (h2o) and nitrogen (n2). however, ammonia uniformity pattern usually not homogenization and the ammonia was difficult to mix with nox. the constant air flows incomplete to assist the spray injector to spread nh3 to all corners of scr. the impact study of turbulent phenomena and standard k-epsilon low-reynolds number model to the mixing process in the scr system using starccm+. the simulation studies are conducted under different pressure (4 to 6 bars), the injection rate (0.04 g/s) and temperature (338 k – 553 k) and the high pressure and high velocity magnitude creating turbulent swirl flow. the ammonia decomposition process and mixing process with nox were investigated using a box with optical access. the simulation and numerical study results validated using back pressure value and the distribution of nox concentration value from the catalyst outlet. the wall temperature will increase the urea evaporation to generate ammonia and gas pressure will increase the mixing process and chemical process in the scr system. these reactions enable to optimize the scr system technology which eventually able to reduce the nox quantity from a diesel engine. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: diesel engine; wall temperature; wall impingement; urea water solution (uws); urea injection; selective catalytic reduction (scr). i. introduction diesel engines are commonly used for public transportation on-road and off-road applications. growth production of the diesel engine is very significant year to year [1]. the diesel engine is used for commercial and passenger vehicle [2][3][4]. some of the major advantages of diesel engine over another fuel engine are the higher durability and increased fuel efficiency. on the other hand, the main disadvantage is related to exhaust emissions from the diesel combustion process. the emission of the diesel engine is one of the major sources of air pollution which need to be controlled by the aftertreatment system. government has released a regulation for automotive industry related to the exhaust gas emission to further reducing the nitrogen oxide emissions. the emission rules have reached the pollution limit of the euro vi and the us tier 2 regulation [1][5][6]. the ammonia in the selective catalytic reduction (scr) as the main solution to control specific emissions from the engine. the technology of scr used the injection of a urea liquid into the exhaust system. the hot temperature from exhaust makes a urea-water solution (uws) evaporates and decomposes to be ammonia. ammonia concentrate used as reducing nitrogen oxides (nox) in the scr system. many researchers study around the injector for spraying urea (nh3), gas temperature, and catalyst * corresponding author. tel: +82-01074637823 e-mail address: m.k.aditya.w@gmail.com https://dx.doi.org/10.14203/j.mev.2020.v11.45-54 https://dx.doi.org/10.14203/j.mev.2020.v11.45-54 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.45-54 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.45-54&domain=pdf https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.45-54&domain=pdf https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.45-54&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.45-54&domain=pdf https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.45-54&domain=pdf m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 46 substrate in the scr system, but the ammonia still difficult to mix with nox. based on our previous study [7], it has been mentioned that the urea is difficult to evaporate and easily attached to the wall and making the solid deposit in the system. it is consistent with the study carried out by hasan [8] which found the solid deposited effect to the mixing process at the scr system. the most important concept for the mixing process is the turbulent airflow from the exhaust gas in the scr system. exhaust airflow was assisting the spray injector to spread nh3 to all corners in the scr system. to solve that situation, this study presents a simulation and experimental study of the turbulent phenomena impact and the standard k-epsilon lowreynolds number model to mixing process in the scr system using starccm+. to create turbulent in the scr system, this study uses pressure from the exhaust gas and wall temperature from the scr system. the simulations study based on the exhaust gas system with a high pressure to create turbulent swirl flow. the ammonia decomposition process and mixing process with nox were investigated using a box with optical access. the data obtained from the optical box can assist the identification of the actual condition in the scr system. the effects of wall impingement on deposit formation in diesel scr system has been investigated the wall temperature (338 k) and (573 k). in the previous research carried out by auvray [9], it was shown the temperature (473 k) and (598 k) can be used to analyze kinetic modelling on nh3 in the scr system. furthermore, our previous study [4] also used a high temperature of 536 k to study the ammonia uniformity in scr system technology. a similar study from smith [2], it has used a low temperature of 473 k and a high temperature of 608 k for analyzing the deposit formation reaction. based on those investigations, the temperatures used in this system are 338 k for low wall temperature and 553 k for high wall temperature. the simulation and numerical study results validated using back pressure value and the distribution of nox concentration at the scr system. ii. materials and methods a. mathematical model the numerical study with 3d simulation for understanding the mixing process in the scr system was shown with starccm+ software version 11.04. in another paper from fischer et al. [10], compare the reynolds-averaged k-epsilon-models and reynolds-stress-model (rsm) to accounting the anisotropic character of turbulence in the swirl flow. fischer et al used pipe with oval/flat crosses section for assist mixing process in the scr system. the rsm describe the anisotropic turbulence between the primary swirl core and the outer secondary. this method is useful for understanding the tke values in the pipe cross section and dissipation value in the swirl core. however, the rsm difficult to predict the highly turbulent reaction at the inner and outer swirl core. yi [11] has analyzed the ammonia homogenization from two different mixers with renormalizing of navier-stokes equations (rng) and the k-epsilon model for turbulence study. the computational fluid dynamic (cfd) model of their research simple scr system installation. the straight pipe with urea injector and leading into the catalyst. the urea injector is located at the wall with a 90° angle relative to the main flow. without a mixer system, the low quality of ammonia uniformity has resulted. integrating a helix swirl mixer in the system leads the ammonia to raise the good quality of uniformity. this study was applying straight pipe and optical box with fully scr system. the urea injector is located at top of the optical box. that urea can release the uws spray was from top to bottom. this observed is focus on the distribution of exhaust gas with pressure to get the turbulence quality without the mixer. the eddy viscosity from the k-epsilon equation, determined from a single turbulence length. the calculation of turbulent diffusion can achieve by the specified scale. although in the real system, all motion scales will contribute to the turbulent diffusion. the numerical computation with a realizable kepsilon model for resolved the viscous layers and viscous sublayer in the scr system. these equation functions of wall treatment can be extended and solving the multiphase flow phenomena and motion of gasses from nox and ammonia wherein the gasses is characterized by properties that are aggregated over a large number of individual molecules [12][13]. each particle in the system has associated with a physical equation, such as density, velocity, vorticity and temperature. the vector quantity in the numerical properties assumed to be observable and hence there are ‘streamlines’ at the local velocity vector. streamlines can never cross except at point sources or sinks of fluid. the transport equations for the low-reynolds number with k-epsilon model equation can solve the computational domain: 𝑑 𝑑𝑡 ∫ 𝜌𝜀 𝑑𝑉𝐴 + ∫ 𝜌𝜀�𝑣 − 𝑣𝑔�. 𝑑𝑎𝐴 = ∫ �𝜇 + 𝜇𝑡 𝜎𝜀 �∇𝜀. 𝑑𝑎 𝐴 + ∫ 1 𝑇 �𝐶𝜀𝑙(𝐺𝑘 + 𝐺𝑛𝑙 + 𝐶𝜀3𝐺𝑏) − 𝐶𝜀2𝜌(𝜀 − 𝜀0) + 𝜌𝛾𝑦 + 𝑆𝜀�𝑑𝑉𝑉 (1) where 𝑆𝑘 and 𝑆𝜀 are specified source properties, 𝜀0 is the ambient turbulence value for turbulence decay counteracting, 𝜌 is the source density, and 𝐺′ is the additional product from source term that is given by: 𝐺′ = 𝐷𝑓2 �𝐺𝑘 + 2𝜇 𝑘 𝑑2 � exp�−𝐸𝑅𝑒𝑑 2� (2) where 𝐷 is the distance to the nearest wall of the source terms, 𝑑 is the distance to the wall, 𝑘 is turbulent kinetic energy, 𝜇 is dynamic viscosity, and 𝑓2 is a damping function that is defined as: 𝑓2 = 1 − 𝐶 exp(−𝑅𝑒𝑡2) (3) where 𝑅𝑒𝑑 = √𝑘𝑑 𝑣 (4) and m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 47 𝑅𝑒𝑡 = 𝑘2 𝜀𝑣 (5) the coefficients 𝐶 and 𝐸 are using the default values of 0.3 and 0.00375. and the value for coefficient 𝐷 in the system is in equation (6): 𝐷 = 𝐶𝜀2 𝐶𝜀𝑙 ≈ 1.3 (6) however, direct numerical simulation (dns) of lowreynolds number channel flow suggests that better results are obtained with 𝐷 = 1, which is the default value that is used in starccm+. dns was the presence of free stream turbulence, inaccuracy computing method the 𝐷 = 1 was used for minimizing the error result from turbulence equation. the momentum coupling model for flow sections used the vertices scale, the turbulent viscosity 𝜇𝑡 has a relation on getting the turbulent kinetic energy 𝑘 and dissipation 𝜀, in equation (7): 𝜇𝑡~ 𝑘2 𝜀 (7) with regards to the scalar transport model equation, a direct proportionality of turbulent diffusive momentum and scalar transfer is assumed. this method can explain the turbulent scalar diffusion is directly linked to the turbulence models viscosity prediction in equation (8): 𝜌𝜇𝐽𝛾 = − 𝜇𝑡 𝑆𝑐𝑡 𝜕𝑦 𝜕𝑥𝐽 (8) the constant equation to get the proportionality value is used the turbulent schmidt number 𝑆𝑐𝑡. an underestimated turbulent viscosity value in the equation model can be stable by reducing the schmidt number value (0.7 – 0.9). throughout the following investigations by wardana [7], the turbulent schmidt number for standard k-epsilon low-reynolds number model used the default value of 1.0 for described in this literature review. 1) thermolysis and evaporation of uws droplets despite numerous experimental studies have been conducted [4][14][15], theoretical understanding for the decomposition and evaporation of uws and adblue droplets are still not fully investigated. a theoretical study [9][12] was implemented using starccm+ for simulation which then compared by experimental works to get the best accuracy. this method assumes two processes of the uws evaporation until the uws droplet is only composed of urea. it uses a spherical method for the evaporation and decomposition processes without using urea crystallization in the process. rapid mixing model is used to evaluate the dissolved urea on the evaporation process of urea water solution. because this model can identify the high transport coefficients from the liquid phase. the result can explain the homogenous distribution temperature in the system, concentration particle value and fluid properties in the uws droplet [9]. the variation model in uws concentration droplet's can be evaluated by equation (9): 𝑑𝑌𝑢 𝑑𝑡 = − 𝑚𝑣𝑎𝑝 𝑚𝑑 𝑌𝑢 (9) where 𝑚𝑑 is the mass of droplet particle, 𝑑𝑌𝑢 is urea concentration value and 𝑚𝑣𝑎𝑝 is a vapour value of mass flow in the system. the evaporation rates in this equation are calculated by the abramzonsirignano model [12]. that model useful for low computational to observe the uws droplet particle and suitable predict the spray modelling [12]. the urea particle will easily melt at 400 k [12] and the arrhenius model can describe that chemical kinetics reaction by equation (10): 𝑑𝑌𝑢 𝑑𝑡 = −𝐴𝑓𝑆 exp �− 𝐸𝑎 𝑅𝑇𝑑 � (10) where 𝑆 is droplet surface area in the system, 𝐴𝑓 is the frequency factor [kg/(sm2)], 𝑅 is the universal value, 𝑇𝑑 is the droplet temperature for gas constant and 𝐸𝑎 is the activation of energy in the system. 2) urea water solution injection urea-water solution is the most commonly used for ammonia precursor in the scr system because this material was safe for the environment. the commercial name for uws was adblue, this aqueous was a combination from 67.5 to 70 % deionized water and 30 to 32.5 % urea [12]. gas emission from diesel engine usually produces more than 90 % of nox and 5 to 10 % of no2. that quantity depending on the diesel engine type. no2 from diesel engine emission is useful for fast scr reaction process. that chemical is produced from engine-emitted no when oxidation reaction in the catalyst. in order to describe the uws injection phenomena in the scr systems, this study used a mathematical description to explain all processes [3][9][12]: • interaction momentum between exhaust gas and uws droplets • thermolysis and evaporation of uws droplets • heat transfer from exhaust temperature to the wall and droplets. this section presents the mathematical basics model to implement the cfd modelling conduct the numerical simulations of the scr system by straccm+ software. the flowchart model for this simulation is shown in figure 1. figure 1. the flowchart of simulation process m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 48 b. experimental setup the experiment condition used a single cylinder with 498 cm3 of displacement, naturally aspirated engine with 4-cycle, and sohc 4 valves system to get the precision of the engine test. the engine specification is shown in table 1. the pressure at the exhaust was 4 to 6 bar [5][6][16] and leading into the optical box with straight pipe. a schematic diagram for the optical box test is shown in figure 2. the pressure from uws injector was ranging from 4 to 6 bar, the ammonia injection rate (0.04 g/s) and exhaust temperature constant in 338 k – 553 k [5][6][16]. the injection specification is presented in table 2. the optical box for measuring position and dimension was realized with silica glass. the positions and dimension were chosen to minimize the effect of the gas flow in the system. the optical box gas flow distribution is shown in figure 3. the mixing process between nox and ammonia is observed in the optical box. the horiba mexa7100degr is used to identify the emissions value from the system (hydrocarbon and nox). c. validation of simulation to verify the standard k-epsilon low-reynolds number model simulation results from starccm+, the observation from ammonia uniformity at the scr system have been carried out on the experiment test [5][17]. the exhaust line directly connects with the scr system. the horiba mexa-7100degr can determine the gas distribution and the hydrocarbon value from the catalyst outlet. the standard k-epsilon low-reynolds number equation model is suitable for computing the convection flows. the situations to have a lowreynolds number version of the standard k-epsilon model, and non-linear constitutive model as shown in table 3. the setups have two-equation models for the simulation of the measured ammonia uniformity. the error value for the velocity magnitude model is a good agreement to observe the validated literature cases for the k-epsilon model in the scr system simulation [2][11]. by considering the complete process from uws spray to the ammonia distribution in the optical box. table 1. engine specification engine parameter value displacement 498 cm 3 bore 83 mm stroke 92 mm compression ratio 19.5 con. rod length 145.8 mm crank radius 43.74 mm valve system sohc 4 valve fuel system electronic common rail table 2. ammonia and exhaust injection parameter value exhaust inlet 10, 15, 20 m/s injector inlet 10, 15 m/s injection rate 0.04 g/s temperature 338 k – 553 k pressure 4, 5, 6 bar figure 2. schematic diagram of test engine and measurement setup table 3. analyzed turbulence models and boundary conditions setup turbulance model boundary condition a 1 standard low reynold number k-epsilon pi vo av = velocity; p = pressure; i = inlet; o = outlet m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 49 iii. results and discussions a. exhaust simulation gas simulated distribution of the exhaust pressure streamlines in an optical box system, as it has been predicted by starccm+. this simulation using the standard k-epsilon low-reynolds number model with the prediction on the effect of exhaust gas for ammonia decomposition phenomena can be calculated with the schmidt number value. this energy value used to determine the turbulent viscosity and diffusion constant in the equation model. besides that, this simulation model is implying the reduction of the anisotropic information for turbulent energy quantity at least for the scalar transport value. figure 4 shows the difference turbulence streamline and scalar distribution in the optical box. gas flow in the optical box is the most important indicator to mix ammonia and nox. this flow strongly influences the homogenization of ammonia vapour, even without a sufficient temperature from figure 4. the difference turbulence streamline and scalar distribution in the optical box: (a) exhaust turbulent phenomena and (b) exhaust scalar phenomena figure 3. the measurement position of exhaust flow and ammonia injector spraying to the optical box: (a) urea injection spray pattern; (b) exhaust gas pattern; (c) combination pattern from urea and exhaust gas m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 50 the ammonia injection. the amount of pressure for mixing process of nox and ammonia is shown in figure 4(a). this picture described a pressure ratio between the lowest (4 bar) and the highest (6 bar). the colour line explains the velocity value in the simulation. however, the quality of the mixing process from figure 4 was explained by the quantity of gas distribution in the simulation. it affects the different movement of air in the optical box. when the higher pressure was used, this condition makes the more diffuse flow of air generated and it was a good result for mixing ammonia and nox. but instead, when the smallest pressure is used, ammonia and nox mixing is difficult to be created as airflow having difficulties to spread close to the wall and makes ammonia on the wall could not be parsed by airflow. the airflow and pressure quantity also increasing the wall temperature value in the optical box. figure 4(b) explains the temperature distribution in the simulation. heating wall temperature propagates by flowing heat of exhaust gas from inlet to the outlet, more high gas flows from the exhausts more heat of the wall temperature, and its effects on the reduction ammonia droplet in the wall. this statement also has been explained in our previous study [7] which is observed the wall temperature value for predict the urea injection process in the scr system. figure 5 shows the velocity magnitude quality. as can be seen from the figure, the constant exhaust flow mass value achieve at 0.045 kg/s, the maximal flow mass value achieve at 3.15 kg/s and minimal flow mass at -3.5 kg/s in the optical box. the free gas at the optical box makes flow mass in an optical box unstable in the first time. flow mass is difficult to spared before free gas come out from the optical box. that case also happens in constant velocity magnitude. maximal velocity occurred due to the empty condition when the exhaust gas inside the optical box. figure 6 shows the pressure and force value. as can be seen from figure 6, constant pressure occurred in 20 s after the exhaust come from the inlet. an empty condition in the optical box makes pressure decrease significantly to -102.15 bar. exhaust gas occupies empty space in the optical box to encourage the free gas came out from outlet to generate exhaust force gas and make pressure increase constantly after declining. maximal pressure happens in 13.2 bar and decrease after 12 s exhaust came from the inlet. that was contradicted with exhaust gas force value when the exhaust gas pressure value decreases in an optical box, exhaust gas forces increase until 19.78 kn and the force value decrease on -2.63 kn. massive pressure was counted by volume of the optical box, the extent of affecting the increase and decrease of the exhaust gas pressure against time. with a dimension of 90 x 30 x 30 cm3 of the optical box, the exhaust pressure needs 20 s for stabilizing into 1 bar. if using the small volume that can easily stable lowest than this simulation. b. injector effect on exhaust simulation gas the distribution of the exhaust pressure can predict the streamline reaction in the optical box. at figure 5. velocity and flow mass effect at the optical box m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 51 the first step of the exhaust inside the optical box, the pressure of exhaust was dropped to -102.15 bar, that condition also happen in the real scr in public vehicles. the amount of the pressure drop was depending on the size of the exhaust muffler (pipe and scr system). when the scr system has a pressure drop, the exhaust flow is difficult to spear the adblue from urea injector. the urea from adblue attached in the wall will settle and harden because the wall will heat up due to the creeping temperature of the engine heat. that reaction has an effect after long period application of scr system in the diesel engine. the timing for spraying adblue in commercial diesel engine has been analyzed in exhaust simulation gas. for injector condition, the constant pressure and velocity value can set the turbulent flow in the system. the distribution of gas and liquid were accounted, but it does not give an insignificant impact from the spray characteristic in the flow field. that reaction occurring because the injector has low pressure and momentum for spraying the uws. nonetheless, the flow field during the transient condition keeps valid. figure 7 shows the difference turbulence streamline from uws injector and exhaust gas in the optical box. this simulation shows that the nox and ammonia mixing can be observed and analyzed in the optical box. nonetheless, interdependencies from the liquid and gas phase with swirl fan mixing are avoided in this study. the ammonia vapour concentrations got the averaged value by each computational cell when one-time injection duration. the resulting quasi-steady spatial for ammonia distributions value is observed on the cross sections as long as in the steady flow quantities. the simulation was plausible with visualizing and evaluates the ammonia homogenization process in the optical box. the turbulent kinetic energy (tke) is the main parameter to determine turbulent viscosity and turbulent diffusion in this simulation [5]. figure 8 shows the tke value on the optical box. this tke result got the maximum curves when the exhaust gas comes to the inlet (2.5 s). the gas flow distribution creating the steep velocity gradients by the source of turbulence. the kinetic energy structure divided into smallscale structures turbulence energy and transferred into dissipates rate of energy. the turbulent dissipation value in the system is shown in figure 7. though just using the k-epsilon model, the turbulent scheme showed very clearly. beside that for detail result, it still needs more deeply parameter using deference mathematic model. c. k-epsilon model validation the ammonia uniformity in this study resulted that without a mixer system, the low quality of ammonia uniformity has resulted. integrating a helix swirl mixer in the system leads the ammonia to raise the good quality of uniformity. that result is explained on this validation purposes [10]. 2 results from this study will be compared to find the best values by the standard k-epsilon low-reynolds number model [10]. figure 9 shows the back pressure value between simulation and experiment in the optical box. this result explains the mass flow quantity from exhaust temperature and the amount of gas distribution. the standard k-epsilon low-reynolds number model has been calculated by heat temperature from exhaust inlet with the increasing wall temperature parameter. in that case, the temperature was the figure 6. pressure and force effect at the optical box m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 52 most decisive to mix ammonia and nox, besides the turbulence in the optical box. the back pressures value occurring at low volume condition can determine the magnitude of measurement precision. this parameter condition useful for computation in the validation discussion. the particular range in this simulation has offset value of approximately 1.0 bar and that value better 0.2 bar from rsm simulation condition. the measuring value for back pressure at high volume flow occurs when the measurement has precise and reliable data [10]. that parameter can predict simulation by comparing the figure 7. exhaust and injector turbulent phenomena of (a) with low exhaust pressure and (b) with high exhaust pressure figure 8. turbulent kinetic energy (tke) and turbulent dissipation rate (tds) effect in optical box m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 53 different turbulent model, which is expected to get similarities and accuracy data measurement and simulation. iv. conclusion simulated distribution of the exhaust pressure streamlines in the optical box system, as it has been predicted by starccm+. gas flow in the optical box is the most important indicator to mix ammonia and nox. this flow strongly influences the homogenization of ammonia vapour, even without using a sufficient temperature from ammonia injection. heating wall temperature propagates by flowing heat of exhaust gas from inlet to the outlet, more high gas flow from exhausts more heat the wall temperature, and the effect on the reduction ammonia droplet in the wall. the free gas at the optical box makes a mass flow in the optical box unstable in the first time. with a dimension of 90 x 30 x 30 cm3 of the optical box, the exhaust pressure needs 20 s for stabilizing into 1 bar. if using the small volume that can easily stable lowest than this simulation. an empty condition in the optical box makes the pressure decrease so deeply until -102.15 bar when exhaust came from the inlet. massive pressure was counted by volume of the optical box used, the extent of affecting the increase and decrease of the exhaust gas pressure against time. for injector condition, the constant pressure and velocity value can set the turbulent flow in the system. the distribution of gas and liquid were accounted, but it does not give an insignificant impact from the spray characteristic in the flow field. that reaction occurring because the injector has low pressure and momentum for spraying the uws. nonetheless, the flow field during the transient condition keeps valid. the turbulent kinetic energy (tke) is the main parameter to determine turbulent viscosity and turbulent diffusion in this simulation. in comparison tke curves and tds curve, the result has a different path to describe the turbulent energy based on the region section. the high momentum in this result can validate the strong energy from the exhaust to increase the distribution of ammonia in the system. although this study has different parameter and cfd models with others study, this result can be good knowledge for the researcher to understand the mixing process of ammonia and nox in scr system technology. acknowledgement this work was supported by a research program supported by the department of mechanical engineering (generation fuel and smart power train laboratory), university of ulsan, republic of korea. nomenclature cfd : computational fluid dynamic mars : monotone advection and reconstruction scheme nox : nitrogen oxide k : kelvin temperature scale scr : selective catalyst reduction tke : turbulent kinetic energy tds : turbulent dissipation rate uws : urea water solution rsm : reynolds stress model declarations author contribution m.k.a. wardana as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] r. conway, s. chatterjee, m. naseri, and c. aydin, “demonstration of scr on a diesel particulate filter system on a heavy duty application,” sae int., 2015. [2] h. smith, t. lauer, v. schimik, and k. gabel, “evaluation and prediction of deposit severity in scr systems,” sae int. j. engines, vol. 9, no. 3, pp. 2016-01–0970, 2016. [3] j. baleta, h. mikulčić, m. vujanović, z. petranović, and n. duić, “numerical simulation of urea based selective non-catalytic reduction denox process for industrial applications,” energy convers. manag., 2016. [4] m.k.a. wardana, g.m.h. shahariar, k. oh, and o. lim, “ammonia uniformity to predict nox reduction efficiency in an scr system,” int. j. automot. technol., vol. 20, no. 2, pp. 313– 325, 2019. [5] h. smith, m. zöchbauer, and t. lauer, “advanced spray impingement modelling for an improved prediction accuracy of the ammonia homogenisation in scr systems,” sae tech. pap., 2015. [6] p. gaynor, b. reid, g. hargrave, t. lockyer, and j. wilson, “an experimental investigation into def dosing strategies for heavy duty vehicle applications,” sae int. j. engines, vol. 8, no. 3, pp. 1196–1206, 2015. [7] m.k.a. wardana, k. oh, y. j. lee, y. m. woo, and o. lim, “effects of urea injection timing on predicting nox conversion in scr systems,” int. j. automot. technol., vol. 21, no. 1, pp. 137–145, 2020. [8] g.m.h. shahariar, m.k.a. wardana, and o. t. lim, “investigation of urea-water solution spray impingement on the hot surface of automotive scr system,” j. mech. sci. technol., vol. 32, no. 6, pp. 2935–2946, 2018. figure 9. comparison pressure loss at mixing device https://doi.org/10.4271/2015-01-1033 https://doi.org/10.4271/2015-01-1033 https://doi.org/10.4271/2015-01-1033 https://doi.org/10.4271/2016-01-0970 https://doi.org/10.4271/2016-01-0970 https://doi.org/10.4271/2016-01-0970 https://doi.org/10.1016/j.enconman.2016.01.062 https://doi.org/10.1016/j.enconman.2016.01.062 https://doi.org/10.1016/j.enconman.2016.01.062 https://doi.org/10.1016/j.enconman.2016.01.062 https://doi.org/10.1007/s12239-019-0031-x https://doi.org/10.1007/s12239-019-0031-x https://doi.org/10.1007/s12239-019-0031-x https://doi.org/10.1007/s12239-019-0031-x https://doi.org/10.4271/2015-01-1054 https://doi.org/10.4271/2015-01-1054 https://doi.org/10.4271/2015-01-1054 https://doi.org/10.4271/2015-01-1054 https://doi.org/10.4271/2015-01-1028 https://doi.org/10.4271/2015-01-1028 https://doi.org/10.4271/2015-01-1028 https://doi.org/10.4271/2015-01-1028 https://doi.org/10.1007/s12239-020-0014-y https://doi.org/10.1007/s12239-020-0014-y https://doi.org/10.1007/s12239-020-0014-y https://doi.org/10.1007/s12239-020-0014-y https://doi.org/10.1007/s12206-018-0550-9 https://doi.org/10.1007/s12206-018-0550-9 https://doi.org/10.1007/s12206-018-0550-9 https://doi.org/10.1007/s12206-018-0550-9 m.k.a. wardana and o. lim / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 45-54 54 [9] x. auvray et al., “kinetic modeling of nh3-scr over a supported cu zeolite catalyst using axial species distribution measurements,” appl. catal. b environ., vol. 163, no. 2, pp. 393–403, 2015. [10] s. fischer, r. bitto, t. lauer, c. krenn, j. tauer, and g. pessl, “impact of the turbulence model and numerical approach on the prediction of the ammonia homogenization in an automotive scr system,” sae int. j. engines, vol. 5, no. 3, pp. 1443–1458, 2012. [11] y. yi, “development of a 3d numerical model for predicting spray, urea decomposition and mixing in scr systems,” sae int., no. 724, 2007. [12] j. baleta, m. vujanović, k. pachler, and n. duić, “numerical modeling of urea water based selective catalytic reduction for mitigation of nox from transport sector,” j. clean. prod., vol. 88, pp. 280–288, 2015. [13] m. colombo, i. nova, e. tronconi, v. schmeiβer, and m. weibel, “mathematical modelling of cold start effects over zeolite scr catalysts for exhaust gas aftertreatment,” catalysis today, vol. 231. pp. 99–104, 2014. [14] b. opitz et al., “simulation study of scr catalysts with individually adjusted ammonia dosing strategies,” chemical engineering journal, vol. 264. pp. 936–944, 2015. [15] h. nishiyama, y. tanaka, and t. adachi, “a study on the improvement of nox reduction efficiency for a urea scr system,” sae tech. pap., vol. 46, no. 3, pp. 589–595, 2015. [16] t. lockyer, b. reid, g. hargrave, p. gaynor, and j. wilson, “optical investigation on the ability of a cordierite substrate mixing device to combat deposits in scr dosing systems,” sae tech. pap., vol. 2015-april, no. april, 2015. [17] m. zöchbauer, h. smith, and t. lauer, “advanced scr flow modeling with a validated large eddy simulation,” sae int., vol. 1046, no. 3, p. 14, 2015. https://doi.org/10.1016/j.apcatb.2014.08.003 https://doi.org/10.1016/j.apcatb.2014.08.003 https://doi.org/10.1016/j.apcatb.2014.08.003 https://doi.org/10.1016/j.apcatb.2014.08.003 https://doi.org/10.4271/2012-01-1291 https://doi.org/10.4271/2012-01-1291 https://doi.org/10.4271/2012-01-1291 https://doi.org/10.4271/2012-01-1291 https://doi.org/10.4271/2012-01-1291 https://doi.org/10.4271/2007-01-3985 https://doi.org/10.4271/2007-01-3985 https://doi.org/10.4271/2007-01-3985 https://doi.org/10.1016/j.jclepro.2014.06.042 https://doi.org/10.1016/j.jclepro.2014.06.042 https://doi.org/10.1016/j.jclepro.2014.06.042 https://doi.org/10.1016/j.jclepro.2014.06.042 https://doi.org/10.1016/j.cattod.2014.01.044 https://doi.org/10.1016/j.cattod.2014.01.044 https://doi.org/10.1016/j.cattod.2014.01.044 https://doi.org/10.1016/j.cattod.2014.01.044 https://doi.org/10.1016/j.cej.2014.11.114 https://doi.org/10.1016/j.cej.2014.11.114 https://doi.org/10.1016/j.cej.2014.11.114 https://doi.org/10.4271/2015-01-2014 https://doi.org/10.4271/2015-01-2014 https://doi.org/10.4271/2015-01-2014 https://doi.org/10.4271/2015-01-1039 https://doi.org/10.4271/2015-01-1039 https://doi.org/10.4271/2015-01-1039 https://doi.org/10.4271/2015-01-1039 https://doi.org/10.4271/2015-01-1046 https://doi.org/10.4271/2015-01-1046 https://doi.org/10.4271/2015-01-1046 introduction ii. materials and methods a. mathematical model 1) thermolysis and evaporation of uws droplets 2) urea water solution injection b. experimental setup c. validation of simulation iii. results and discussions a. exhaust simulation gas b. injector effect on exhaust simulation gas c. k-epsilon model validation iv. conclusion acknowledgement nomenclature declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.51-56 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel nurul shahirah rukman a, ahmad fudholi a, b, *, putri adia utari c, cheku nurul aisyah a, andri joko purwanto b, rakhmad indra pramana b, erie martides b, ant. ardath kristi b, nilofar asim a, mohammad hossein yazdi d, hazim moria e, husam abdulrasool hasan f, zeki ahmed darwish g a solar energy research institute, universiti kebangsaan malaysia bangi selangor, 43600, malaysia b research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komp lipi bandung, jl. sangkuriang, west java, 40135, indonesia c centre for deep sea research, indonesian institute of sciences (lipi) jl. syaranamual, guru-guru, poka, ambon, 97233, indonesia d dept. of electric power generation stations, network and supply systems, institute of engineering and technology, south ural state university 76, lenin avenue, chelyabinsk, 454080, russian federation e department of mechanical engineering technology, yanbu industrial college yanbu al-sinaiyah city, 41912, kingdom of saudi arabia f department of air conditioning and refrigeration engineering, al esra'a university college baghdad, iraq g ministry of education, united arab emirates, dubai po. box 3962, dubai received 21 february 2021; accepted 24 june 2021; published online 31 july 2021 abstract a photovoltaic (pv) system integrated with a bi-fluid cooling mechanism, which is known as photovoltaic thermal (pvt) system, was investigated. the electrical characteristics of flexible solar panel were evaluated for pv and pv with bi-fluid (air and water) cooling system. the integration of monocrystalline flexible solar panel into both systems was tested under a fixed solar radiation of 800 w/m2. a total of 0.04 – 0.10 kg/s of air flow was utilized in pv with cooling system with a fixed water mass flow rate of 0.025 kg/s. the efficiencies of flexible panel for pv and pv with cooling system were explored. for pv with bifluid flow, the highest obtained efficiency of module was 15.95 % when 0.08 kg/s of air and 0.025 kg/s of water were allowed to flow through the cooling system. compared with pv without cooling mechanism, the highest efficiency of module was 13.35 % under same solar radiation. current– voltage and power graphs were also plotted to present the electrical characteristics (current, voltage, and power) generated by both systems. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: pv efficiency; pv current; pv voltage; pv power; i–v–p curves. i. introduction solar energy is a renewable energy that can produce heat via a thermal system and generate electricity via photovoltaic (pv) module. a photovoltaic-thermal (pvt) collector is a system which has a pv module combined with a thermal collector system. the system is able to produce electrical energy directly from sunlight by using photoelectric effect. meanwhile, it also extracts heat from the pv and warms the fluid inside the collector. when a pvt collector is irradiated with solar energy, the cell temperature increases prominently. the greater the temperature difference between ambient temperature and temperature of the cell is the less efficient the electrical efficiency and electrical output of the pv module becomes. in order to enhance the electrical efficiency, this excess heat is extracted by passing a heat extracting fluid (water or air) under the module. this integrated method, where thermal and electrical energy are generated * corresponding author. phone:+62-812-7519-3956 e-mail address: a.fudholi@gmail.com https://dx.doi.org/10.14203/j.mev.2021.v12.51-56 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.51-56 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.51-56&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ n.s. rukman et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 52 simultaneously, is the basis of pvt collectors [1][2][3][4]. due to the dual functions of a pvt collector, this type of collector maximizes the use of solar energy resulting in a higher overall solar conversion rate than that of solely pv or solar collector. the pv cells composed of semiconductor material convert highenergy photons of incident solar radiation into electricity. the lower energy photons are absorbed by the pv panel and generate heat within the cells [5]. the generation of heat within the cell reduces the efficiency of the cells. the photovoltaic thermal (pvt) technology extracts a great percent of this heat and utilizes it for practical applications [6]. the removal of heat from the cell and transferring it to the working fluid increases the electrical efficiency of the pv module while simultaneously producing hot fluid which can be used for thermal applications. since pvt offers an improved method of utilizing solar energy, the overall efficiency of the system is higher [7][8][9]. there are several advantages of pvt collectors over individual pv or thermal collectors discussed in various literatures. one way to enhance the efficiency of the pvt system is by using heat transfer area through the absorber with finned absorber, corrugated surfaces and porous media. the pvt system can be classified into four types based on heat transfer medium, namely the air-based pvt system, water-based pvt system, the combination of water/air-based pvt system and nanofluid-based pvt system [10][11][12][13]. the concept of combining two fluids to cool a pvt collector was firstly introduced in 2007. however, the fluids are applied individually in each time [14]. a design that focuses on the water and air heating component has been proposed to improve bi-fluid pvt system. the results for independent mode operation are concluded as satisfactory. higher efficiencies on thermal, electrical and overall systems are attained for simultaneous system operation [15]. recently, a new concept of hybrid pvt was introduced by othman et al. [16], and this system includes pvt combination with water and air heating. at the chosen optimum mass flow rate throughout the experiment, the total thermal equivalent efficiency is as high as 76 % when the fluids are operated simultaneously. integration of two working fluids in a single pvt system has shown various results in improving the efficiency of pvt or pv with cooling system. the current study aims to investigate the effects of bifluid utilisation on the pv module efficiencies and the electrical characteristics generated by pv and pv with cooling systems. in the end of the study, the use of flexible pv as module for indoor test of pv and pv without cooling system is validated. ii. materials and methods the pv with cooling system was integrated with glazing, which complemented the duct of air flow in the cooling system, as shown in figure 1. the setup of pv with cooling system consisted of pv and cooling system in one integrated arrangement and is also known as pvt system. the utilisation of two types of fluids (water and air) for the cooling system required piping arrangement for the water flow and air duct for the air flow to complete the system. as can be seen in figure 1, it shows the thermocouples which were used to configure the temperature of each designated part of the system. they were pasted by using aluminium tape which in return affected the exposure area of the panel surface to the solar radiation. a study proved that the shaded area of the panel must be less than 50 % from the total area in order to ensure that the power output is increasing more than 5 % [17]. figure 2 shows the setup of the system, which was positioned under a solar simulator that acted as the source of solar radiation. the solar simulator acted as the source of the solar energy that radiated upon the system. the simulator consisted of 40 halogen lamps, amongst which nine were arranged in a row. the generated solar radiation was regulated by 9 voltage regulators, amongst which 1 regulated a row of solar simulator. in the setup, two paths of coolant flow were considered for water and air. tanks a and b stored the water flow. tank a was the reservoir tank of water outlet flowing from the water channel. in the meantime, tank b functioned as the cooling tank where the outlet water from tank a was pumped into for cooling. normal pipe water was loaded, and spiral copper tube was soaked into it to act as the (a) (b) figure 1. (a) flexible photovoltaic panel (table 1); (b) integrated with spiral absorber (the water flow channel) table 1. specification of flexible pv panel model symbol values maximum power pmax 100 w voltage at pmax vmp 17.6 v current at pmax imp 5.68 a open-circuit voltage voc 21.2 w short-circuit current isc 6.25 a irradiance i 1000 w m2⁄ temperature t 25 °c n.s. rukman et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 53 channel for cooling down the water outlet before being re-used as an inlet and regulated at preferred mass flow. the air channel was a single path flow of air in which the air input was from the fan installed at the end of collector. the air channel was in between the glass and pv panel and was used to contribute and regulate an evenly distributed heat absorbed by the panel. the speed of the fan was regulated using a dimmer and was then measured by an anemometer. anemometer readings were used to calculate the mass flow rate of air. figure 3 shows other equipment components, namely water tanks, spiral absorber, flowmeter and water pump, were used. the spiral absorber used was made of stainless steel because steel is a good heat conductor. the amount of water allowed to flow was regulated using the flowmeter (1 – 4 g/m) mounted at the inlet of spiral absorber. the water flow absorbed the heat conducted between the pv panel and spiral absorber to maintain optimum temperature for the pv during operation. an 80 w of water pump was applied to tank a to aid the flow process for providing pressure for the water to flow from the outlet tank (tank a) to the cooling tank (tank b) as shown in figure 2. copper coil acted as the medium of water cooling as it flowed through. the water outlet was cooled before the fluid entered the inlet system, during which the flow was controlled by the flowmeter as shown in figure 3. previous studies conducted on pvt have integrated different kinds of absorber designs in using fluid as coolant. the performance of waterbased pvt with various pattern configurations was compared [18][19]. the outcome with the best performance is achieved using spiral absorber because of the closed-gap between the tubes and large number of areas covered by the pv panel with the absorber attached to it. in the present research, the data collected were analysed to determine the electrical characteristics of flexible pv panel for pv and pv with cooling system. the data recorded were listed as follows: • the data from the logger comprised the readings of each thermocouple pasted on systems, including the temperatures of glass, air inlet and outlet, pv panel, water inlet and outlet and absorber and the ambient temperature of the room. • the data from the electronic load included those of current and voltage generated by the flexible pv during the experiment. the data on the temperature of pv panel were mainly discussed due to the concerns of this study. this temperature influenced the electrical energy generated by the pv. the experiment compared the differences when coolants were used or ignored. the temperature difference of coolants (water and air) was briefly explained to justify the effect of coolant use. furthermore, the performance of pvt bi-fluid system was compared with that of pv system. the electricity generated was dependent on the temperature of the solar panel throughout the experimental session and the temperature change of the coolants (water and air) in the bi-fluid system. thermocouple type k was pasted at certain designated parts of the system to detect temperature readings whilst the end of the thermocouples was connected to the ports of data logger. the logger was used to record the data measured by the thermocouple, and the temperature was recorded at each minute for 30 min. the experiment began with the radiation from solar simulator, which was regulated by the voltage regulator. pyranometer epley with a solar constant of 9.13×10–6 was used to measure the radiation radiated for matching the radiation that had been supplied to the system to the desired radiation (800 w/m2). then, the flow of coolants was started, and the readings were logged onto the logger. as the data from the temperature readings were automatically recorded, an electronic load was figure 2. schematic of experimental setup for pv with cooling system figure 3. the overview of the system set up before it had been placed under the solar simulator n.s. rukman et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 54 connected to the pv panel to obtain its generated electrical energy. the readings were manually measured 15 min before the experiment ended. the obtained data were used to plot the i– v curve graph for determining the maximum power produced by the pv panel. the data for current and voltage obtained were plotted on the i– v curve graph. then, equation 1 was used to find the maximum power output. in this equation, 𝑃𝑚 is the maximum power output and 𝐼𝑚 and 𝑉𝑚 are the maximum generated current and voltage, respectively. pm = im × vm (1) the features of a pv solar panel can be removed from the pv solar panel output, which can be explained by the resulting i– v curve nature. the fill factor (ff) of a pv panel was measured from the real i– v characteristic curve. ff is defined as the maximum power produced by the cell against the open circuit voltage (𝑉𝑂𝑂 ) and the closed-circuit current (𝐼𝑆𝑂). ff can be written as [20] ff = pm voc×isc (2) the equation provided was used to calculate the electrical efficiency that was generated by the pv for comparing the effects of cooling fluids to the flexible pv panel for its efficiency. in this equation, 𝜂𝑒𝑒 is the efficiency of the panel and 𝜂𝑟𝑒𝑟 is the efficiency of pv by the manufacturer. other terms β, 𝑇𝑃𝑃, and 𝑇𝑟𝑒𝑟 are the thermal coefficient (0.0045 °c–1), mean temperature of pv surface during the operation (°c) and mean reference temperature (25 °c). the third equation was used to attain the electrical efficiencies of both systems and was used to analyse temperature dependence [17][18][19]. ηpv = ηref[1 − β(tpv − tref)] (3) iii. results and discussions a. control system response with pole placement method the reference efficiency of pv was 17.8 %, and the actual efficiencies of pv were obtained using equation (3). the first to the third repeated experiments for pv system recorded 13.63 %, 12.98 % and 13.45 % of efficiencies, as shown in table 2. for pv with bi-fluid cooling system, the experimental investigation was performed using water with a mass flow rate of 0.025 kg/s at four different air mass flow rates (0.04, 0.06, 0.08 and 0.1 kg/s). in this experiment, a fixed solar radiation of 800 w/m2 was radiated upon flexible solar panel, which was integrated at the top of the system. for each varied parameter of air mass flow rate with constant water mass flow, the experiment was repeated three times. moreover, the maximum power generated was calculated using equation (2). the electrical efficiencies of pv with bi-fluid cooling system were compared to find the optimum bi-fluid parameter that generated maximum electrical energy. table 3 shows that the average efficiencies of pv for pv with bi-fluid cooling system were 15.94 %, 15.95 %, 15.89 %, and 15.78 %. the lowest efficiency of 13.95 % was recorded by pv without cooling system. therefore, the temperature of the panel influences the efficiencies of the pv module. specifically, as the temperature of the pv surface increased, the efficiencies of pv decreased. figures 4 show the i– v– p curve that was graphed for 800 w/m2 radiated upon bi-fluid pvt with varied mass flow of air (0.04, 0.06, 0.08, and 0.1 kg/s) at a fixed water mass flow rate of 0.025 kg/s. the graphs represent the best result amongst the three repeated experiments for each parameter of varied air mass flow rate. the pv with bi-fluid cooling system should be more efficient in generating energy than standalone pv system. in this research, the prediction was proven, and the conclusions were explained. the experiment with the flow of bi-fluid was repeated three times for each parameter of mass flow rate. the best result amongst the three repeated operations was chosen, as shown in figure 4 (a) to (d). table 4 lists the data that had been graphed. as table 2. electrical characteristics of flexible pv panel without bi-fluid cooling system under fixed solar radiation solar radiation, s (w/m2) pmax (w) isc (a) voc (v) fill factor eletrical efficiency of pv, 𝛈𝐞𝐞 (%) 18.17 1.726 16.28 0.647 13.63 800 17.34 1.711 16.17 0.627 12.98 17.17 1.711 16.09 0.643 13.45 table 4. maximum power attained by pvt system at constant water mass flow rate with varied air mass flow rate mass flow rate (kg/s) voltage (v) current (a) maximum power (w) water air 0.025 0.04 11 0.55 5.995 0.025 0.06 12 0.59 7.081 0.025 0.08 13 0.57 7.384 0.025 0.1 12 0.55 6.588 table 3. efficiencies of pv panel in terms of the temperature of the panel type of system mass flow rate of fluid (kg/s) temperature of flexible pv panel (°c) efficiencies of pv panel (%) water air pv with bi-fluid cooling system 0.025 0.1 47.90 15.97 47.12 16.03 49.53 15.84 0.08 48.92 15.88 47.21 16.02 48.31 15.93 0.06 46.71 16.06 49.06 15.87 50.73 15.74 0.04 48.93 15.88 50.34 15.77 51.51 15.68 pv without cooling system not available not available 77.09 13.63 85.18 12.98 79.31 13.45 n.s. rukman et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 55 observed, the results insignificantly differed from each other under constant solar radiation and mass flow rate of water with varied air flow rate. the results of maximum power generated showed that it increased from 5.995 w to 7.384 w firstly and then dropped to 6.588 w. the reason was that the module did not withstand the converged radiation from the solar simulator and it can be seen due to a sudden decrease in maximum power produced as has been tabulated in table 4. one of the reasons that led to this result is due to the high pv cell temperature due to increase in solar radiation which affected the performance of the solar panel [21]. iv. conclusion the following conclusions were obtained from the experimental results. the electrical characteristics of bi-fluid pvt system using flexible solar panel were discussed. for pv with bi-fluid flow, the highest efficiency of module obtained was 15.95 % when 0.08 kg/s of air and 0.025 kg/s of water were allowed to flow through the cooling system. compared with the pv without cooling mechanism, the highest efficiency of module was 13.35 % under same solar radiation. the indoor experiment using flexible design of pv showed that it should be integrated to an outdoor system of pvt. this incapability affected its performance in energy generation. acknowledgment the authors would like to thank the ukm for funding geran galakan penyelidik muda (ggpm2014-029), as well as the solar energy research institute (seri) for providing laboratory facilities and technical support. declaration author contribution all authors contributed equally as the main contributor of this study. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of (a) (b) (c) (d) figure 4. i– v– p curve for the average test conducted at: (a) 0.04 kg/s of air mass flow rate with fixed rate of water mass flow; (b) 0.06 kg/s of air mass flow rate with fixed rate of water mass flow; (c) at 0.08 kg/s of air mass flow rate with fixed rate of water mass flow; (d) at 0.1 kg/s of air mass flow rate with fixed rate of water mass flow 0 0.2 0.4 0.6 0.8 0 1 2 3 4 5 6 7 0 5 10 15 20 p o w er ( w ) c u rr en t (a ) voltage (v) power current 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 1 2 3 4 5 6 7 8 0 5 10 15 20 p o w er ( w ) c u rr en t (a ) voltage (v) power current 0 0.2 0.4 0.6 0.8 0 2 4 6 8 0 5 10 15 20 p o w er ( w ) c u rr en t (a ) voltage (v) power current 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 1 2 3 4 5 6 7 0 5 10 15 20 p o w er ( w ) c u rr en t (a ) voltage (v) power current https://mev.lipi.go.id/ n.s. rukman et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 51-56 56 sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] n. s. rukman, a. fudholi, ivan taslim, merita ayu indrianti, intan noviantari manyoe, "overview on recent photovoltaic module cooling methods: advances pvt systems." indonesian journal of electrical engineering and computer science (ijece), 10 (1), 15-21, 2020. [2] n. s. rukman, a. fudholi, s.h. zaidi, k. sopian, "overview of bifluid-based photovoltaic thermal (pvt) systems," international journal of power electronics and drive systems (ijpeds), 9 (4), 1912-1917, 2018. [3] m. y. othman, s. a. hamid, m. a. s. tabook, k. sopian, m. h. roslan, and z. ibarahim, "performance analysis of pv/t combi with water and air heating system: an experimental study," renewable energy 86, 716–722, 2016. [4] r. kumar and m. a. rosen, "a critical review of photovoltaicthermal solar collectors for air heating," applied energy, 88 (11), 3603–3614, 2011. [5] p. ooshaksaraei, k. sopian, s. h. zaidi, and r. zulkifli, "performance of four air-based photovoltaic thermal collectors configurations with bifacial solar cells," renewable energy, 102, 279–293, 2016. [6] j. cremers, i. mitina, n. palla, f. klotz, x. jobard, and u. eicker, "experimental analyses of different pvt collector designs for heating and cooling applications in buildings." energy procedia, 78, 1889–1894, 2015. [7] a. kumar, p. baredar, and u. qureshi, "historical and recent development of photovoltaic thermal (pvt) technologies,", renewable and sustainable energy review, 42, 1428–1436, 2015. [8] n.s. nazri, a. fudholi, b. bakhtyar, c.h. yen, a. ibrahim, m.h. ruslan, s. mat, k. sopian, "energy economic analysis of photovoltaic–thermal-thermoelectric (pvt-te) air collectors," renewable and sustainable energy review, 92, 187-97, 2018. [9] n.s. nazri, a. fudholi, c.h. yen, m. mohammad, m.h. ruslan, k. sopian," exergy and improvement potential of hybrid photovoltaic thermal/thermoelectric (pvt/te) air collector," renewable and sustainable energy review, 111, 132-144, 2019. [10] h.a. hasan, k. sopian, a. fudholi, "photovoltaic thermal solar water collector designed with a jet collision system," energy, 161, 412-424, 2018. [11] s.s.s. baljit, h.-y. chan, v.a. audwinto, s.a. hamid, a. fudholi, s.h. zaidi, m.y. othman, k. sopian, "mathematical modelling of a dual-fluid concentrating photovoltaic-thermal (pv-t) solar collector," renewable energy, 114, 1258–1271, 2017. [12] a. fudholi, m. zohri, g.l jin, a. ibrahim, c.h. yen, m.y. othman, m.h. ruslan, k. sopian, "energy and exergy analyses of photovoltaic thermal collector with ∇-groove," solar energy, 159, 742-750, 2018. [13] a. fudholi, n.f.m. razali, m.h. yazdi, a. ibrahim, m.h. ruslan, m.y. othman, k. sopian, "tio2/water-based photovoltaic thermal (pvt) collector: novel theoretical approach," energy," 183, 305-314, 2019. [14] y. tripanagnostopoulos, "aspects and improvements of hybrid photovoltaic/thermal solar energy systems," solar energy, 81, 1117–1131, 2007. [15] m.n. abu bakar, m. othman, m. hj din, n.a. manaf, h. jarimi, "design concept and mathematical model of a bi-fluid photovoltaic/thermal (pv/t) solar collector," renewable energy, 67, 153–164, 2014. [16] m.y. othman, s.a. hamid, m.a.s. tabook, k. sopian, m.h. roslan, z. ibarahim, "performance analysis of pv/t combi with water and air heating system: an experimental study," renewable energy, 86, 716–722, 2016. [17] c. tubniyom, w. jaideaw, r. chatthaworn, a. suksri, t. wongwuttanasatian, "effect of partial shading patterns and degrees of shading on total cross-tied (tct) photovoltaic array configuration," energy procedia, 153, 35-41, 2018. [18] a. ibrahim, a. fudholi, k. sopian, m.y. othman, m.h. ruslan. "efficiencies and improvement potential of building integrated photovoltaic thermal (bipvt) system," energy conversion and management, 77, 527-534, 2014. [19] c.n. aisyah, a. fudholi, m.y. othman, a. ibrahim, m.h. ruslan, k. sopian, "efficiency of pv/t collector using spiral thermal absorber design (kecekapan pengumpul pv/t menggunakan pengumpul terma reka bentuk pilin)," sains malaysiana, 47 (4), 853-859, 2018. [20] a. fudholi, k. sopian, m.h. yazdi, m.h. ruslan. a. ibrahim, h.a. kazem, "performance analysis of photovoltaic thermal (pvt) water collectors," energy conversion and management, 78, 641-651, 2014. [21] n.f.m. razali, a. fudholi, m. hafidz ruslan, k. sopian, "electrical characteristic of photovoltaic thermal collector with water-multiwalled carbon nanotube nanofluid flow", indonesian journal of electrical engineering and computer science, 13 (1), 324-330, 2019. http://doi.org/10.11591/ijece.v10i1.pp15-21 http://doi.org/10.11591/ijece.v10i1.pp15-21 http://doi.org/10.11591/ijece.v10i1.pp15-21 http://doi.org/10.11591/ijece.v10i1.pp15-21 http://doi.org/10.11591/ijece.v10i1.pp15-21 http://doi.org/10.11591/ijpeds.v9.i4.pp1912-1917 http://doi.org/10.11591/ijpeds.v9.i4.pp1912-1917 http://doi.org/10.11591/ijpeds.v9.i4.pp1912-1917 http://doi.org/10.11591/ijpeds.v9.i4.pp1912-1917 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.apenergy.2011.04.044 https://doi.org/10.1016/j.apenergy.2011.04.044 https://doi.org/10.1016/j.apenergy.2011.04.044 https://doi.org/10.1016/j.renene.2016.10.043 https://doi.org/10.1016/j.renene.2016.10.043 https://doi.org/10.1016/j.renene.2016.10.043 https://doi.org/10.1016/j.renene.2016.10.043 https://doi.org/10.1016/j.egypro.2015.11.356 https://doi.org/10.1016/j.egypro.2015.11.356 https://doi.org/10.1016/j.egypro.2015.11.356 https://doi.org/10.1016/j.egypro.2015.11.356 https://doi.org/10.1016/j.rser.2014.11.044 https://doi.org/10.1016/j.rser.2014.11.044 https://doi.org/10.1016/j.rser.2014.11.044 https://doi.org/10.1016/j.rser.2014.11.044 https://doi.org/10.1016/j.rser.2018.04.061 https://doi.org/10.1016/j.rser.2018.04.061 https://doi.org/10.1016/j.rser.2018.04.061 https://doi.org/10.1016/j.rser.2018.04.061 https://doi.org/10.1016/j.rser.2018.04.061 https://doi.org/10.1016/j.rser.2019.03.024 https://doi.org/10.1016/j.rser.2019.03.024 https://doi.org/10.1016/j.rser.2019.03.024 https://doi.org/10.1016/j.rser.2019.03.024 https://doi.org/10.1016/j.rser.2019.03.024 https://doi.org/10.1016/j.energy.2018.07.141 https://doi.org/10.1016/j.energy.2018.07.141 https://doi.org/10.1016/j.energy.2018.07.141 https://doi.org/10.1016/j.renene.2017.08.001 https://doi.org/10.1016/j.renene.2017.08.001 https://doi.org/10.1016/j.renene.2017.08.001 https://doi.org/10.1016/j.renene.2017.08.001 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.solener.2017.11.056 https://doi.org/10.1016/j.energy.2019.06.143 https://doi.org/10.1016/j.energy.2019.06.143 https://doi.org/10.1016/j.energy.2019.06.143 https://doi.org/10.1016/j.energy.2019.06.143 https://doi.org/10.1016/j.solener.2007.04.002 https://doi.org/10.1016/j.solener.2007.04.002 https://doi.org/10.1016/j.solener.2007.04.002 https://doi.org/10.1016/j.renene.2013.11.052 https://doi.org/10.1016/j.renene.2013.11.052 https://doi.org/10.1016/j.renene.2013.11.052 https://doi.org/10.1016/j.renene.2013.11.052 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.renene.2015.08.061 https://doi.org/10.1016/j.egypro.2018.10.028 https://doi.org/10.1016/j.egypro.2018.10.028 https://doi.org/10.1016/j.egypro.2018.10.028 https://doi.org/10.1016/j.egypro.2018.10.028 https://doi.org/10.1016/j.enconman.2013.10.033 https://doi.org/10.1016/j.enconman.2013.10.033 https://doi.org/10.1016/j.enconman.2013.10.033 https://doi.org/10.1016/j.enconman.2013.10.033 http://dx.doi.org/10.17576/jsm-2018-4704-25 http://dx.doi.org/10.17576/jsm-2018-4704-25 http://dx.doi.org/10.17576/jsm-2018-4704-25 http://dx.doi.org/10.17576/jsm-2018-4704-25 http://dx.doi.org/10.17576/jsm-2018-4704-25 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.1016/j.enconman.2013.11.017 https://doi.org/10.11591/ijeecs.v13.i1.pp324-330 https://doi.org/10.11591/ijeecs.v13.i1.pp324-330 https://doi.org/10.11591/ijeecs.v13.i1.pp324-330 https://doi.org/10.11591/ijeecs.v13.i1.pp324-330 https://doi.org/10.11591/ijeecs.v13.i1.pp324-330 i. introduction ii. materials and methods iii. results and discussions a. control system response with pole placement method iv. conclusion acknowledgment declaration author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.137-146 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: s. hartanto and desmayadi, “plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 137-146, dec. 2022. plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a sri hartanto a, *, desmayadi b a teknik elektro, universitas krisnadwipayana jalan kampus unkris no.1, jatiwaringin, jakarta, 13077, indonesia b nissinbou industries, inc 3-10, nihonbashi yokoyama-cho chuoku, tokyo, japan received 27 november 2021; revised 21 december 2021; accepted 20 january 2022; published online 29 december 2022 abstract there is a chance of leakage in the plumbing caused by water pressure in the pipes, improper installation of pipe connections, or external influences, such as earthquakes. plumbing leakage that is detected too late can cause damage to other systems. it is necessary to have a plumbing leakage detection system to detect a leak in the plumbing. therefore, in this research, a plumbing leakage detection system is designed with a water level detector (wld) controlled by a programmable logic controller (plc) type omron cpm2a. the method used in this research is designing the optimal model form of the system, which is distinguished by designing hardware and software, testing the devices, such as power supply, wld, and channel relay module (crm), and making conclusions. from the results of this research, it was found that the system works well in detecting leakage of plumbing, as indicated by all transistors' ability to work well where the electrodes (e1 and e2) are connected by water. the transistor in the wld module will work as a switch or transistor in the saturation position. in this research, it can be seen that even though there is a leakage from the relay contacts of 1.8 vdc, it is still considered in a safe condition because to provide a trigger to the 3b3d module, a minimum of 12 vdc is required. in addition, when the relay is not working or off, the measurement at the normally closed (nc) terminal is 12 vdc. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: channel relay module (crm); leakage detection; programmable logic controller (plc); water level detector (wld). i. introduction plumbing leakage is a problem because whenever there is a leakage somewhere, it cannot be found at an early stage and can become a big problem, leading to water wastage [1]. the basic principle of leakage detection is the loss of pressure on one of the sensors at a fast rate. the use of the pressure transmitter sensor changes it from a sensor to a signal that can be decoded by the controller [2]. the liquid level (as in, e.g., water level) is the height associated with the liquid-free surface, especially when it is the topmost surface. it may be measured with a level sensor [3]. the water level control is a tool that can make it easier to identify the water level in the water reservoir [4]. the automatic water level controller minimizes the need for manual switching and human interference. the machine helps to detect the level of water or any liquid [5]. water flow sensors detect a different value during water leakage occurred [6]. the sensor module collects the relevant data to decide whether the applications to be monitored are working effectively under certain threshold values [7]. the water leakage detection system can be deployed in the already existing plumbing with flow rate sensors attached to the path of the water flow [8]. constant leakages through pipes in walls lead to water seepage, which may damage the structural components of the building [9]. the control of all equipment has been performed through the use of computers. most equipment uses * corresponding author. tel: +62-218462230; fax: +62-218462231 e-mail address: srihartanto@unkris.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.137-146 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.137-146 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.137-146&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:srihartanto@unkris.ac.id s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 138 programmable logic controller (plc) to connect with computers to monitor each load and electricityconsuming devices [10]. the plc constitutes one of the main architectures of manufacturing system control and is programmed with standardized languages [11]. by integrating motion control into the plc, the control system was greatly simplified because simple motion control can be realized by the plc without a special motion controller [12]. plc is time-driven with time stamps defined by the input/output (i/o) scanning and does not receive/emit events but logic variables. hence, the input and output events must be defined from combinations of variables [13]. plc plays a significant role in automatic control systems. a ladder diagram is the most widely used programming language for plc, which is transparent and intuitive since the variables are represented as graphical symbols and each instruction is graphical [14]. plc projects commonly use five programming languages including two textual languages, i.e., structured text (st) and instruction list (il), and three graphical languages, i.e., function block diagram (fbd), ladder diagram (ld), and sequential function chart (sfc) [15]. plc application program development is becoming crucial due to the growing complexity of control problems associated with the demand for high-quality solutions [16]. the sensor and actuator signal data are collected from the plc memory through a single communication channel (as collecting data from the actual sensors and actuators is extremely costly); and only a fraction of those signals can be accessed at a given time [17]. the essential role of plc is to interact with sensors and actuators [18]. plcs are providing the bridge between the cyber and physical worlds by controlling devices such as valves, pumps, and motors in response to operator input or their preprogrammed control logic [19]. input-output specification of the plc-based function block for considered control law has to be compatible with the specification of the presented "identification block" [20]. the goal of plc data collection is to record both the input and output values whenever there is a change in any of the i/o values [21]. the ladder logic programming language requires the programmer to create diagrams of input and output relays to depict the order and circumstances in which connected devices are toggled and act [22]. ladder logic is one of the most used programming languages to feed instructions into the plc [23]. the plc control logic process deals with the input signals before producing output to regulate the connection and disconnection of the liner circuit [24]. therefore, in this research, a plumbing leakage detection system controlled by the plc type omron cpm2a was designed. in order to determine the location of leakage more precisely, it inserts the detector on the building's water line shaft or at a probable leak. this research is focused on measuring and analyzing the stability of the power supply and measuring the performance of the water level detector (wld) in the plumbing leakage detection system controlled by the plc type omron cpm2a. ii. materials and methods the flowchart of this research methodology that describes the steps carried out in this research is shown in figure 1. the steps carried out in this research are • design; distinguished by designing hardware, which includes making the design of the device to be made, determining the components and dimensions of the device to be made, and designing software, which includes making ladder diagrams on the cx programmer which the plc is then programmed with. • testing; measures the hardware and software that has been made. • analysis; analysing the tests carried out on the system with measurements of the power supply output, electronic circuits on the wld, and the channel relay module (crm). • conclusion; making a distinguish conclusion from research data that has been previously analysed. a. designing the overall model system a control unit usually consists of three steps: input, computing, and output, and each task is executed cyclically. in the input step, the control unit reads the values of the sensors. in the computing step, the control unit performs some computations such as numerical calculations and conditional judgment, etc. in the output steps, the control unit modifies the values of the variables that are mapped to some output points or control actuators to conduct certain mechanical actions by providing output signals to driver devices [25]. figure 1. research methodology flowchart s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 139 controllers are generated for random systems with different values of the prediction horizon, the system delay, and the dimensions of the state, control input, and system output. the controller is programmed on the plc [26]. the design of the plumbing leakage detection system controlled by the plc type omron cpm2a can be seen in figure 2. in figure 2, the designed system is divided into six parts, namely the input process using a wld as a water level detector, which then activates the crm as a direct bit information provider to the plc type omron cpm2a to be processed. the results of data processing are displayed by the omron nb7-tw00b humanmachine interface (hmi). in addition, the power supply serves to supply power to the system via the plc type omron cpm2a. b. designing the water level detector the wld as shown in figure 3 is made with electronic components including a single pole solid relay 12 vdc as a relay that will activate dry contact normally open (no)/normally closed (nc), diode 1n4001/4002 as polarity reverse current protection in the relay coil, transistor bd441/d400 npn as a function switching, resistors, and capacitors. the wld will work when there is induction in positive and negative polarities. the voltage source used is 12 vdc. two copper rods will act as electrodes when immersed in water. the existence of a resistance value of the two copper rods causes the transistor to work to open the channel from the collector to the emitter and activate the 12 vdc relay coil. the dry contact of the relay is used to provide logic 1 as a trigger for the 3b3d module. the wld as shown in figure 4 requires a standby voltage of 12 vdc which is connected to the (+) and (-) terminals, the voltage polarity must match. at terminals e1 and e2, a cable connection is installed to the electrode stick/copper rod as a water level detector. at the no terminal when the system is working or the wld detects water, the terminal will issue 12 vdc which will be used as a trigger, and during normal standby, the no standby terminal is at 0 vdc. in this research, 10 wlds are placed on each floor, and the distance between each wld is 2.5 meters. all wlds on each floor work to detect water pipe leakage by detecting waterlogging on each floor. c. designing the channel relay module the circuit of crm can be seen in figure 5. in the crm, there is a 3b3d module as a digital timer that can be set from 0–999 minutes and there are 4 timer options, namely delay off, delay on, delay on and off, and consistent delays on and off. in designing the plumbing leakage detection system, the 3b3d module is used to adjust the pulse signal. the com terminal is the trigger input to activate this module, which is controlled by wld as shown in table 1. d. designing plc type omron cpm2a as controller plc used in this system is plc type omron cpm2a which has the specifications shown in table 2. the plc requires a voltage source of 220 vac, for the com terminal and input it uses 24 vdc which comes from the plc's internal voltage source. the software used to create the ladder diagram is cx programmer version 9.5 and the type of plc selected when programming the cx programmer is plc type omron cpm2a. in the ladder diagram of the input detector section as shown in figure 6 and 3 figure 3. electronic circuit of wld figure 2. block diagram of system design s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 140 figure 7, the bit information that enters both logics 0 and 1 at addresses 0.00 to 0.07 is a binary value that will be converted to hexadecimal with the bcd (24) instruction on data memory 0 (dm0). then the incoming bits for addresses 0.00 to 0.07 can be ascertained apart from binary with a value of 0, a value above 1 then logic 1 will activate lr9.04 which is used as a relay bit to activate the t0003 timer, where this timer functions as a time lag whether the wld is in the area is a true alarm. the ladder diagram was created as initials of data representing decimal constant values into initials in the data memory (dm), the instructions used is the mov instruction (21), the value used is #1 to #255 then initialized to dm1 to dm255 which also represents detector 1 to detector 255. the p_on instruction is used because the command instructions in this initial data section must always be active or always on the flag as shown in figure 8 and figure 9. to activate the alarm there is only one option, namely when the lr9.04 alarm occurs. on the bell lr9.04 when a logic 1 will activate the 10.00 output, which is the bell output, lr9.02 is used to activate lr.9.03 which will activate t0001, i.e., the timer to pause the alarm time, thereby causing the alarm to figure 4. water level detector figure 5. channel relay module com no nc no com com + _ po w er s u pp ly 12 v d c + _ e1 e2 nc el ek tr od a d et ec to r avr 24 to 5 vdc +_ s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 141 be deactivated. if t0001 is reactivated then the 10.00 outputs will be active again or the bell will ring. when the alarm is in progress and the bell is deactivated, if a new alarm is entered, the bell can be reactivated because lr9.04 is the main input. for strobe lr9.04 will activate output 10.01 which is the strobe output address on the plc, output 10.01 will be off if input 1.01 is a logic reset address 1. during the alarm, the strobe will remain active can be seen in figure 10. iii. results and discussions testing the device is carried out to determine the performance of each component used. this test is expected to get good results where all components of the plumbing leakage detection system work. when the start button (channel 1.00) is pressed on the main menu on the hmi screen, the system is completely disabled in monitoring status. while a waterlogging on one floor has crossed the water level limit of 30 mm, the detection rod connected to the water causes a resistance value in the wld circuit which then puts the transistor in the table 1. crm addressing no. crm address relay logic 1. relay 1 1 0.00 0 2. relay 2 1 0.01 0 3. relay 3 1 0.02 0 4 relay 4 1 0.03 0 5 relay 5 1 0.04 0 6 relay 6 1 0.05 0 7 relay 7 1 0.06 0 8 relay 8 1 0.07 0 table 2. specification of plc type omron cpm2a specification number i/o 40 input 24 dc output 16 relays power 100-240 vac figure 6. ladder diagram 1 of detector input s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 142 saturation position. this causes the current from the collector of the transistor to flow to the emitter so that the relay coil gets a voltage of 12 vdc and the relay works. furthermore, the no terminal on the wld gives an output of +12 vdc so that it triggers the crm. the design of this plumbing leakage detection system uses 10 wlds with addresses 1 to 10. active relays on the crm will send bits to the plc input group, namely addresses 0.00 to 0.07 (8 bits). the 8-bit signal from the sensor circuit to the plc is initialized with dm0 and will be compared with dm1 to dm255 which is the initial decimal address 1 to 255. if dm0 is the same as data memory 1 to 255 then the alarm will be active on the screen monitoring status of the wld with the output address used for alarm status is ir20.00 to ir35.14. the new alarm will still be displayed on the hmi screen, even though the alarm on the other wld is still in alarm status. while the alarm is active, the plc activates the bell output (10.00) and strobe (10.01). figure 7. ladder diagram 2 of detector input figure 8. ladder diagram 1 of initial data s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 143 a. power supply measurement when a 220 vac power supply which is the main power source is supplied to the system by activating a single-phase miniature circuit breaker (mcb) which supplies a 220 vac voltage source to the power supply, the system works normally. by measuring three types of power supplies that have three types of power supplies, 12 vdc, 24 vdc, and 5 vdc which makes the plc on and connected to the crm. figure 9. ladder diagram 2 of initial data figure 10. ladder diagram of alarm s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 144 in the initial observations, all components after the 220 vac power supply provided could work well or normally. measurement of the voltage issued by the power supply is carried out when the system is working (on) and not working (off). from the results of the power supply measurements in table 3, it can be analyzed that the output voltage when there is a load (the system is working) decreases by 0.15 to 0.2 vdc when compared to the output voltage when there is no load (the system is not working). this decrease is still within the safe tolerance value of the supply voltage of the components. all power supplies work well because the measurement results in no-load values of 24.2 vdc, 12.1 vdc, and 5 vdc which indicate the output voltage according to the specifications of the power supply. b. water level detector measurement from table 4, the results of the transistor work measurements can be analyzed. when the electrodes (e1 and e2) are connected by water, the transistor in the wld module will work as a switch or transistor in saturation position. at saturation, the average collector current (𝐼𝑐) is 1.73 ma and the base current (𝐼𝑏) is 117.8 ma while the 𝑉𝑐𝑐 voltage is 205 mv. in this position, the relay on the wld will work because the relay coil gets a voltage of 12 vdc. when e1 and e2 is disconnected or not connected, the transistor will be cutoff, i.e., the transistor acts as a switch in the open position. in the cutoff position, it can be seen that 𝑉𝑐𝑐 has a value of 12 vdc, 𝐼𝑐 has a value of 0 ma and 𝐼𝑏 has a value of 0 ma. in this position, the relay in the wld will be off because the relay coil does not get a voltage or 0 vdc. all transistors can work well because from the measurement results obtained values when saturation 𝑉𝑐𝑐 has a value of 0.203 to 0.207 vdc, ic has a value of 116 to 118 ma, and 𝐼𝑏 has a value of 1.73 ma and when cut off 𝑉𝑐𝑐 has a value of 12 vdc, 𝐼𝑐 has a value of 0 ma, and 𝐼𝑏 has a value of 0 ma which shows the transistor is working properly. from the measurement results of the crm in table 5, it can be analyzed that the relay coil measures 11.8 to 12 vdc. when the relay does not work, the measurement of the relay coil results in 0 vdc, and the breakdown voltage at the no terminal which should be in the open position is 1.8 vdc. even though there is a leakage from the relay contacts of 1.8 vdc, it is still considered in a safe condition because to provide a trigger to the 3b3d module with a minimum of 12 vdc. when the relay is not working or off, the measurement at the nc terminal is 12 vdc. all relays on the crm are functioning well because from the measurement results, the coil input value is 11.8 to 12 vdc and when the coil does not get a voltage input, the relay will turn off which indicates it is in accordance with the relay specifications. table 3. measurement results of power supply voltage performance measurement 𝑽𝒊𝒊𝒊𝒊𝒊 (v) 𝑽𝒐𝒊𝒊𝒊𝒊𝒊 (v) function no-load (off) under load (on) melan well lrs-75-24 220 24.2 24 hmi, avr yamasaki 220 12.1 11.8 wld eta-sei svm05sc24 24 5.2 5 crm table 4. measurement results of transistor performance in wld circuit wld condition of e1 and e2 tr 𝑽𝒄𝒄 (v) 𝑰𝒄 (ma) 𝑰𝒃 (ma) 1 connected q1 0.205 117.5 1.73 disconnected 12 0 0 2 connected q2 0.204 116.8 1.73 disconnected 12 0 0 3 connected q3 0.206 117.8 1.73 disconnected 12 0 0 4 connected q4 0.205 117.8 1.73 disconnected 12 0 0 5 connected q5 0.203 116.8 1.73 disconnected 12 0 0 6 connected q6 0.205 117.6 1.73 disconnected 12 0 0 7 connected q7 0.206 117.8 1.73 disconnected 12 0 0 8 connected q8 0.205 117.8 1.73 disconnected 12 0 0 9 connected q9 0.203 117.8 1.73 disconnected 12 0 0 10 connected q10 0.206 118.8 1.73 disconnected 12 0 0 s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 145 iv. conclusion this research resulted in the conclusion that all power supplies work well because the measurement results in no-load values of 24.2 vdc, 12.1 vdc, and 5 vdc which indicate the output voltage according to the specifications of the power supply; all transistors can work well because from the measurement results obtained values when saturation 𝑉𝑐𝑐 has a value of 0.203 to 0.207 vdc, 𝐼𝑐 has a value of 116 to 118 ma, and 𝐼𝑏 has a value of 1.73 ma and when cut off 𝑉𝑐𝑐 has a value of 12 vdc, 𝐼𝑐 has a value of 0 ma, and 𝐼𝑏 has a value of 0 ma which shows the transistor is working properly, and all relays on the crm are functioning well because from the measurement results, the coil input value is 11.8 to 12 vdc and when the coil does not get a voltage input, the relay will turn off which indicates it is in accordance with the relay specifications. in this research, it can be seen that even though there is a leakage from the relay contacts of 1.8 vdc, it is still considered in a safe condition because to provide a trigger to the 3b3d module, a minimum of 12 vdc is required. in addition, when the relay is not working or off, the measurement at the nc terminal is 12 vdc. declarations author contribution sri hartanto is the main contributor to this paper, whose role is in designing hardware and software, writing, conceptualization, formal analysis, while desmayadi helps in designing hardware and software as well as investigations and data validation. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] r. dixit, h. chaudhari, s. jadhav, and k. jagtap, “water level and leakage detection system with its quality analysis based on sensor for home application,” international journal of innovative research in science, engineering and technology (ijirset), vol. 7(5), pp. 5534-5542, 2018. [2] b. perangin-angin and a. a. b. sitepu, “water pipe leakage detector using a pressure transmitter sensor with a remote distance smartphone display,” journal of technomaterial physics, vol. 3(1), pp. 15-20, 2021. [3] md. s. a. momin, p. roy, mr. md. g. kader, md. s. hasan, and s. islam, “construction of digital water level indicator and automatic pump controlling system,” international journal of research, vol. 3(12), pp. 1-5, 2016. [4] r. wahyuni, j. t. sentana, muhardi, and y. irawan, “water level control monitoring based on arduino uno r3 atmega 238p using lm0161 lcd at stmik hang tuah pekanbaru,” journal of robotics and control (jrc), vol. 2(4), pp. 265-269, 2021. [5] a. pandey, g. andhale, a. sonawane, a. amrutkar, and t. andhare, “automatic water level indicator and controller,” international journal for research in applied science & table 5. measurement results of crm wld relay (crm) coil voltage (v) contact output (v) no nc 1 on 11.8 12 1.8 off 0 1.8 12 2 on 11.8 12 1.8 off 0 1.8 12 3 on 11.8 12 1.8 off 0 1.8 12 4 on 11.8 12 1.8 off 0 1.8 12 5 on 11.8 12 1.8 off 0 1.8 12 6 on 11.8 12 1.8 off 0 1.8 12 7 on 11.8 12 1.8 off 0 1.8 12 8 on 11.8 12 1.8 off 0 1.8 12 9 on 11.8 12 1.8 off 0 1.8 12 10 on 11.8 12 1.8 off 0 1.8 12 https://mev.lipi.go.id/ https://doi.org/10.15680/ijirset.2018.0705145 https://doi.org/10.15680/ijirset.2018.0705145 https://doi.org/10.15680/ijirset.2018.0705145 https://doi.org/10.15680/ijirset.2018.0705145 https://doi.org/10.15680/ijirset.2018.0705145 https://doi.org/10.32734/jotp.v3i1.5546 https://doi.org/10.32734/jotp.v3i1.5546 https://doi.org/10.32734/jotp.v3i1.5546 https://doi.org/10.32734/jotp.v3i1.5546 https://journals.pen2print.org/index.php/ijr/article/view/5359/5161 https://journals.pen2print.org/index.php/ijr/article/view/5359/5161 https://journals.pen2print.org/index.php/ijr/article/view/5359/5161 https://journals.pen2print.org/index.php/ijr/article/view/5359/5161 https://doi.org/10.18196/jrc.2489 https://doi.org/10.18196/jrc.2489 https://doi.org/10.18196/jrc.2489 https://doi.org/10.18196/jrc.2489 https://doi.org/10.18196/jrc.2489 https://doi.org/10.22214/ijraset.2022.40435 https://doi.org/10.22214/ijraset.2022.40435 https://doi.org/10.22214/ijraset.2022.40435 s. hartanto and desmayadi / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 137-146 146 engineering technology (ijraset), vol. 10(11), pp. 1043-1047, 2022. [6] p. d. widayaka and l. jauhari, “prototype of water pipe leakage detector using flowmeter sensor based on arduino uno,” journal of applied electrical & science technology, vol. 2(1), pp. 34-38, 2020. [7] a. singh, a. a. kirubaraj, s. senith, and s. r. j. ramson, “industrial parameters monitoring system on temperature and speed for pneumatic cylinder,” international journal of innovative technology and exploring engineering (ijitee), vol. 8(6), pp. 776-780, 2019. [8] s. g. kamble and m. b. kumthekar, “problem associated with plumbing and its maintenance,” international journal of engineering research & technology (ijert), vol. 4(4), pp. 324329, 2015. [9] p. gopalakrishnan, s. abhishek, r. ranjith, r. venkatesh, and v. j. suriya, “smart pipeline water leakage detection system,” international journal of applied engineering research (ijaer), vol. 12(16), pp. 5559-5564, 2017. [10] y. birbir and h. s. nogay, “design and implementation of plcbased monitoring control system for three-phase induction motors fed by pwm inverter,” international journal of systems applications, engineering & development, vol. 2(3), pp. 128-135, 2008. [11] r. pichard, a. philippot, r. saddem, and b. riera, “safety of manufacturing systems controllers by logical constraints with safety filter,” ieee trans. on control systems technology, vol. 27(4), pp. 1659-1667, 2019. [12] h. wu, y. yan, d. sun, and r. simon, “a customized real-time compilation for motion control in embedded plc,” ieee trans. on industrial informatics, vol. 15(2), pp. 812-821, 2019. [13] a. guignard, j. faure, and g. faraut, “model-based testing of plc programs with appropriate conformance relations,” ieee trans. on industrial informatics, vol. 14(1), pp. 350-359, 2018. [14] j. luo, q. zhang, x. chen, and m. zhou, “modeling and race detection of ladder diagrams via ordinary petri nets,” ieee trans. on systems, man, and cybernetics: systems, vol. 48(7), pp. 1166-1176, 2018. [15] y. an, f. qin, b. chen, r. simon, and h. wu, “ontoplc: semantic model of plc programs for code exchange and software reuse,” ieee trans. on industrial informatics, vol. 17(3), pp. 1702-1711, 2021. [16] a. d. vieira, e. a. p. santos, m. h. de queiroz, a. b. leal, a. d. de paula neto, and j. e. r. cury, “a method for plc implementation of supervisory control of discrete event systems,” ieee trans. on control systems technology, vol. 25(1), pp. 175-191, 2017. [17] a. ghosh, s. qin, j. lee, and g. wang, “fbmtp: an automated fault and behavioral anomaly detection and isolation tool for plc-controlled manufacturing systems,” ieee trans. on systems, man, and cybernetics: systems, vol. 47(12), pp. 33973417, 2017. [18] m. a. sehr, m. lohstroh, m. weber, i. ugalde, m. witte, j. neidig, s. hoeme, m. niknami, and e. a. lee, “programmable logic controllers in the context of industry 4.0,” ieee trans. on industrial informatics, vol. 17(5), pp. 3523-3533, 2021. [19] d. formby and r. beyah, “temporal execution behavior for host anomaly detection in programmable logic controllers,” ieee trans. on information forensics and security, vol. 15, pp. 1455-1469, 2019. [20] p. grelewicz, p. nowak, j. czeczot, and j. musial, “increment count method and its plc based implementation for autotuning of reduced order adrc with smith predictor,” ieee trans. on industrial electronics, vol. 68(12), pp. 1255412564, 2021. [21] d. chivilikhin, s. patil, k. chukharev, a. cordonnier, and v. vyatkin, “automatic state machine reconstruction from legacy plc using data collection and sat solver,” ieee trans. on industrial informatics, vol. 16(12), pp. 7821-7831, 2020. [22] n. p. deguglielmo, s. m. s. basnet, and d. e. dow, “introduce ladder logic and programmable logic controller (plc),” presented at the annual conf. northeast section (asee-ne), bridgeport, united states, 2020. [23] i. a. michael, “design of lift group control systems based on plc,” journal of engineering research and reports, vol. 22(3), pp. 31-44, 2022. [24] l. luo and b. liu, “research on plc-based control system for mixing,” presented at the int. conf. on e-product e-service and e-entertainment, henan, china, 2010. [25] j. xiong, j. li, j. shi, and y. huang, “a decomposition-based development method for industrial control systems,” ieee access, vol. 7, pp. 93161-93174, 2019. [26] p. krupa, d. limon, and t. alamo, “implementation of model predictive control in programmable logic controllers,” ieee trans. on control systems technology, vol. 29(3), pp. 11171130, 2021. https://doi.org/10.22214/ijraset.2022.40435 https://doi.org/10.22214/ijraset.2022.40435 https://doi.org/10.36456/best.vol2.no1.2585 https://doi.org/10.36456/best.vol2.no1.2585 https://doi.org/10.36456/best.vol2.no1.2585 https://doi.org/10.36456/best.vol2.no1.2585 https://www.ijitee.org/wp-content/uploads/papers/v8i6/f3675048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i6/f3675048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i6/f3675048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i6/f3675048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i6/f3675048619.pdf https://www.ijert.org/research/problems-associated-with-plumbing-and-its-maintenance-ijertv4is040484.pdf https://www.ijert.org/research/problems-associated-with-plumbing-and-its-maintenance-ijertv4is040484.pdf https://www.ijert.org/research/problems-associated-with-plumbing-and-its-maintenance-ijertv4is040484.pdf https://www.ijert.org/research/problems-associated-with-plumbing-and-its-maintenance-ijertv4is040484.pdf https://www.ripublication.com/ijaer17/ijaerv12n16_19.pdf https://www.ripublication.com/ijaer17/ijaerv12n16_19.pdf https://www.ripublication.com/ijaer17/ijaerv12n16_19.pdf https://www.ripublication.com/ijaer17/ijaerv12n16_19.pdf https://www.naun.org/main/upress/saed/saed-40.pdf https://www.naun.org/main/upress/saed/saed-40.pdf https://www.naun.org/main/upress/saed/saed-40.pdf https://www.naun.org/main/upress/saed/saed-40.pdf https://www.naun.org/main/upress/saed/saed-40.pdf https://doi.org/10.1109/tcst.2018.2827329 https://doi.org/10.1109/tcst.2018.2827329 https://doi.org/10.1109/tcst.2018.2827329 https://doi.org/10.1109/tcst.2018.2827329 https://doi.org/10.1109/tii.2018.2826140 https://doi.org/10.1109/tii.2018.2826140 https://doi.org/10.1109/tii.2018.2826140 https://doi.org/10.1109/tii.2017.2695370 https://doi.org/10.1109/tii.2017.2695370 https://doi.org/10.1109/tii.2017.2695370 https://doi.org/10.1109/tsmc.2016.2647219 https://doi.org/10.1109/tsmc.2016.2647219 https://doi.org/10.1109/tsmc.2016.2647219 https://doi.org/10.1109/tsmc.2016.2647219 https://doi.org/10.1109/tii.2020.2997360 https://doi.org/10.1109/tii.2020.2997360 https://doi.org/10.1109/tii.2020.2997360 https://doi.org/10.1109/tii.2020.2997360 https://doi.org/10.1109/tcst.2016.2544702 https://doi.org/10.1109/tcst.2016.2544702 https://doi.org/10.1109/tcst.2016.2544702 https://doi.org/10.1109/tcst.2016.2544702 https://doi.org/10.1109/tcst.2016.2544702 https://doi.org/10.1109/tsmc.2016.2633392 https://doi.org/10.1109/tsmc.2016.2633392 https://doi.org/10.1109/tsmc.2016.2633392 https://doi.org/10.1109/tsmc.2016.2633392 https://doi.org/10.1109/tsmc.2016.2633392 https://doi.org/10.1109/tii.2020.3007764 https://doi.org/10.1109/tii.2020.3007764 https://doi.org/10.1109/tii.2020.3007764 https://doi.org/10.1109/tii.2020.3007764 https://doi.org/10.1109/tifs.2019.2940890 https://doi.org/10.1109/tifs.2019.2940890 https://doi.org/10.1109/tifs.2019.2940890 https://doi.org/10.1109/tifs.2019.2940890 https://doi.org/10.1109/tie.2020.3045696 https://doi.org/10.1109/tie.2020.3045696 https://doi.org/10.1109/tie.2020.3045696 https://doi.org/10.1109/tie.2020.3045696 https://doi.org/10.1109/tie.2020.3045696 https://doi.org/10.1109/tii.2020.2992235 https://doi.org/10.1109/tii.2020.2992235 https://doi.org/10.1109/tii.2020.2992235 https://doi.org/10.1109/tii.2020.2992235 https://doi.org/10.1109/aseene51624.2020.9292646 https://doi.org/10.1109/aseene51624.2020.9292646 https://doi.org/10.1109/aseene51624.2020.9292646 https://doi.org/10.1109/aseene51624.2020.9292646 https://doi.org/10.9734/jerr/2022/v22i317528 https://doi.org/10.9734/jerr/2022/v22i317528 https://doi.org/10.9734/jerr/2022/v22i317528 https://doi.org/10.1109/iceee.2010.5661377 https://doi.org/10.1109/iceee.2010.5661377 https://doi.org/10.1109/iceee.2010.5661377 https://doi.org/10.1109/access.2019.2927263 https://doi.org/10.1109/access.2019.2927263 https://doi.org/10.1109/access.2019.2927263 https://doi.org/10.1109/tcst.2020.2992959 https://doi.org/10.1109/tcst.2020.2992959 https://doi.org/10.1109/tcst.2020.2992959 https://doi.org/10.1109/tcst.2020.2992959 introduction ii. materials and methods a. designing the overall model system b. designing the water level detector c. designing the channel relay module d. designing plc type omron cpm2a as controller iii. results and discussions a. power supply measurement b. water level detector measurement iv. conclusion declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 v journal of mechatronics, electrical power, and vehicular technology volume 10, 2019 authors index the articles in this volume were authored/co-authored by 40 authors from australia, indonesia, taiwan, italy, japan, and united kingdom. achmad praptijanto, “vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3,” 10(1):7-16 ahmad rajani, “three axis deviation analysis of cnc milling machine,” 10(2):93-101 anik nur handayani, “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” 10(1):36-47 ari priharta, “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” 10(1):36-47 benyamin kusumoputro, “sensorless-bldc motor speed control with ensemble kalman filter and neural network,” 10(1):1-6 budi azhari, “quasi-flat linear pm generator optimization using simulated annealing algorithm for wec in indonesia,” 10(1):29-35 cecilia stevany, “the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines:atp-emtp computational approach,” 10(2):4959 christian asri wicaksana, “exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture,” 10(1):24-28 dalmasius ganjar subagio, “three axis deviation analysis of cnc milling machine,” 10(2):93-101 dian andriani, “smart grid communication applications: measurement equipment and networks architecture for data and energy flow,” 10(2):73-84 didik nurhadi, “exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture,” 10(1):24-28 febrizal, “the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines:atp-emtp computational approach,” 10(2):49-59 feri yusivar, “sensorless-bldc motor speed control with ensemble kalman filter and neural network,” 10(1):1-6 firdaus, “the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines:atp-emtp computational approach,” 10(2):49-59 francisco danang wijaya, “quasi-flat linear pm generator optimization using simulated annealing algorithm for wec in indonesia,” 10(1):29-35 fri murdiya, “the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines:atp-emtp computational approach,” 10(2):4959 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi giambattista gruosso, “vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3,” 10(1):7-16 havel alindo sano, “the effect of lightning impulse characteristics and line arrester to the lightning protection performance on 150 kv overhead lines:atp-emtp computational approach,” 10(2):4959 hendri maja saputra, “three axis deviation analysis of cnc milling machine,” 10(2):93-101 kadek heri sanjaya, “three axis deviation analysis of cnc milling machine,” 10(2):93-101 kamil faqih, “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” 10(1):36-47 ketut wirtayasa, “load characteristic analysis of a double-side internal coreless stator axial flux pmg,” 10(1):17-23 kohei arai, “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” 10(1):36-47 kriya mateeke moses, “exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture,” 10(1):24-28 mikecon cenit, “design and development of the semg-based exoskeleton strength enhancer for the legs,” 10(2):61-71 mostafa nazih, “safety assessment of high voltage substation earthing systems with synthetic geotextile membrane,” 10(2):85-91 muhammad alfian mizar, “exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture,” 10(1):24-28 muhammad fathul hikmawan, “load characteristic analysis of a double-side internal coreless stator axial flux pmg,” 10(1):17-23 muhammad kasim, “load characteristic analysis of a double-side internal coreless stator axial flux pmg,” 10(1):17-23 muhammad rif’an, “sensorless-bldc motor speed control with ensemble kalman filter and neural network,” 10(1):1-6 mulia pratama, “vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3,” 10(1):7-16 pudji irasari, “load characteristic analysis of a double-side internal coreless stator axial flux pmg,” 10(1):17-23 puji widiyanto, “load characteristic analysis of a double-side internal coreless stator axial flux pmg,” 10(1):17-23 ridwan arief subekti, “three axis deviation analysis of cnc milling machine,” 10(2):93-101 rudi darussalam, “smart grid communication applications: measurement equipment and networks architecture for data and energy flow,” 10(2):73-84 tinton dwi atmaja, “smart grid communication applications: measurement equipment and networks architecture for data and energy flow,” 10(2):73-84 vaibhav gandhi, “design and development of the semg-based exoskeleton strength enhancer for the legs,” 10(2):61-71 wahyu primadi, “smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (soc) battery based on mamdani fuzzy logic control,” 10(1):36-47 widiyanti, “exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and ron 90 fuel mixture,” 10(1):24-28 widodo budi santoso, “vehicular networking and computer vision-based distance estimation for vanet application using raspberry pi 3,” 10(1):7-16 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii journal of mechatronics, electrical power, and vehicular technology volume 10, 2019 affiliation index bachelor program, department of mechanical engineering, state university of malang, malang, indonesia 24 building, infrastructure and advanced facilities, jacobs, melbourne, australia 85 department of design engineering and mathematics, middlesex university london, london, united kingdom 61 department of electrical engineering and information technology, engineering faculty, universitas gadjah mada, d.i. yogyakarta, indonesia 29 department of electrical engineering, faculty of engineering, universitas riau, pekanbaru, indonesia 49 department of electrical engineering, national taiwan university of science and technology, taipei, taiwan 17 department of electrical engineering, universitas indonesia, depok, indonesia 1 department of electrical engineering, universitas negeri jakarta, jakarta, indonesia 1 department of electronics, informatics and bioengineering, politecnico di milano, milano, italy 7 department of information science, saga university, saga, japan 36 department of mechanical engineering, state university of malang, malang, indonesia 24 electrical engineering postgraduate, electrical engineering department, universitas negeri malang, malang, indonesia 36 graduate school of technological and vocational education, national yunlin university of science and technology, yunlin, taiwan 24 research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), bandung, indonesia 7, 17, 29, 73, 93 research unit for clean technology, indonesian institute of science (lipi), bandung, indonesia 73 school of electrical engineering and telecommunications, university of new south wales, new south wales, australia 17 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. yusie rizal, phd cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. laksono kurnianggoro department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia suprapto, ph.d departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia alexander christantho budiman ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. phh. mustafa no. 23, bandung, jawa barat, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani,m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted.  heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot.  heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot.  heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket  heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket.  heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points:  make sure you use uniform lettering and sizing of your original artwork.  preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier.  number the illustrations according to their sequence in the text.  use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvii  eps (or pdf): vector drawings. embed the font or save the text as 'graphics'.  tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi.  tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi.  tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not:  supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low.  supply files that are too low in resolution.  submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows  book: author, title. edition, editor , city, state or country: publisher, year, pages.  part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages.  periodical: author, “title”, journal, volume (issue), pages, month, year.  proceeding: author, “title”, in proceeding, year, pages.  unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year.  paten/standart: author, “title”, patent number, month day, year.  technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows:  book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file.  periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file.  papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file.  reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.38-44 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. rotordynamics analysis of solar hybrid microturbine for concentrated solar power maulana arifin a, b, * a research centre for electrical power and mechatronics, indonesian institute of sciences komp lipi bandung, gd 20, lt 2, bandung, west java, 40135 indonesia b institute of thermal turbomachinery and machinery laboratory, university of stuttgart pfaffenwaldring 6, 70569 stuttgart, germany received 15 may 2020; accepted 18 june 2020; published online 30 july 2020 abstract microturbine based on a parabolic dish solar concentrator runs at high speed and has large amplitudes of subsynchronous turbo-shaft motion due to the direct normal irradiance (dni) fluctuation in daily operation. a detailed rotordynamics model coupled to a full fluid film radial or journal bearing model needs to be addressed for increasing performance and to ensure safe operating conditions. the present paper delivers predictions of rotor tip displacement in the microturbine rotor assembly supported by a journal bearing under non-linear vibrations. the rotor assembly operates at 72 krpm on the design speed and delivers a 40 kw power output with the turbine inlet temperature is about 950 °c. the turbo-shaft oil temperature range is between 50 °c to 90 °c. the vibrations on the tip radial compressor and turbine were presented and evaluated in the commercial software gt-suite environment. the microturbine rotors assembly model shows good results in predicting maximum tip displacement at the rotors with respect to the frequency and time domain. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: microturbines rotor tip displacement; parabolic dish solar concentrator; rotordynamics model; journal bearing; non-linear vibration. i. introduction concentrating solar power (csp) is presently primary technology for generating power electricity from solar energy after photovoltaics (pv). commercial csp technology can be commonly divided into the following four main types, that is, linear fresnel reflector, parabolic trough collector, central receiver, and parabolic dish [1]. csp utilizes mirrors set to focus the direct sunlight onto a solar receiver to increase the working fluid temperature. the working fluid then converts its energy to mechanical energy in the thermal engine to produce electrical power. in many studies, it is recognized that parabolic troughs employ reflective surface or mirror with a parabolic-shaped cross-section, which delivers a linear concentration on the receiver tube where a heat transfer fluid temperature can be increased up to 390 °c. the parabolic troughs concentration ratio is typically below 80 [2]. comparable to parabolic troughs, linear fresnel reflector (lfr) systems can heat the working fluid to 450 °c and are generally used in power plants of a few megawatts. meanwhile, central solar towers and parabolic dish solar concentrators have a higher concentration ratio than a parabolic trough (typically more than 1000). both of them have the potential to raise the working fluid to 800 °c, which is necessary for certain types of thermal engines such as gas turbines. however, the solar towers are not applicable for small scale power generation applications (< 50 kw). therefore, a parabolic dish solar concentrator becomes the most suitable for such applications [3]. in the parabolic dish solar concentrator system, microturbine is a crucial component to increase its power and performance. the microturbine consists of turbomachinery components such as radial compressors and turbines [4]. due to the light and small rotor dimensions, microturbine runs at high rotor speeds in various operating conditions. typical rotor speed is around 50,000 to 150,000 rpm, which delivers mechanical or structural stability issues. poor design of the microturbine components can * corresponding author. tel: +49-711-685-63516 e-mail address: maulana.arifin@lipi.go.id https://dx.doi.org/10.14203/j.mev.2020.v11.38-44 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.38-44 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.38-44&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 39 cause low performance and even failure in the assembly system. to overcome these critical issues, a rotordynamic analysis in compressors and turbines can be very beneficial for ensuring safety and increasing the system performance [5]. the nonlinear vibration on the journal or thrust bearing and turboshaft of turbocharger compressor and turbine have been extensively studied in the open literature [6][7]. researchers attempted to evaluate the impact of mode shape degeneration in linear rotordynamics and the effect of thrust bearing for turbocharger components [8][9]. however, rotordynamics analysis on the microturbine based on csp application did not obtain much attention in the open literature and nearly a few works have been presented [5]. the present study highlights a non-linear rotordynamics analysis at design and off-design on the rotor speed of microturbine for csp applications. this could be useful for readers in determining a suitable rotor design, especially for high-speed microturbine applications. this paper also aims to gain more insights into the effect of journal bearing clearance at the turbo-shaft of microturbine. ii. materials and methods in the present study, the turbomachinery components are using cast aluminium material for the radial compressor and inconel-718 for the radial turbine. table 1 shows performance data for both the radial compressor and the turbine components. the power output of the system is about 40 kw at the design point with the turbine inlet temperature (tit) of 950 °c. the weights of the rotors are 100 and 150 grams. for the mechanical supports, the turbo-shaft uses a journal bearing with inner and outer bushing. the primary function of a journal bearing is to maintain the wheels or rotors balance (rotordynamics stability) at all operating conditions of microturbine. due to an interaction between joints and force elements, the rotor assembly modelling is based on the multibody dynamics structure [10]. the turbo-shaft rotor is defined as an assembly of rigid and flexible bodies. therefore, the existing hydrodynamic bearings restrict the global motion in an axial and radial direction (see figure 1). a sleeve bearing is fit into radial compressor journal bearing end and seal installation from the lubricant oil 5w30-62. the oil temperature at the operating condition is between 50 °c to 90 °c. the reynolds lubrication equation is utilized to calculate the flow dynamics and bearing forces in the oil film journal bearing [11]. the numbers for oil film at journal bearing are typically laminar between 100 and 200. the reynolds lubrication equation can be written as: 𝜕 𝜕𝑥 �ℎ3 𝜕𝑝 𝜕𝑥 � + 𝜕 𝜕𝑧 �ℎ3 𝜕𝑝 𝜕𝑧 � = 6𝜂 ��𝑈𝑗 + 𝑈𝑏� 𝜕ℎ 𝜕𝑥 + 2 𝜕ℎ 𝜕𝑡 � (1) where uj is the journal velocity; ub is the bearing ring velocity; h is the oil film thickness; x is the circumferential direction (x = r ); z is the axial direction. based on nguyen-schäfer [11], the nonlinear bearing force is defined as: 𝐹1 = +𝐹𝑟 sin 𝛾 + 𝐹𝑡 cos 𝛾 ≡ 𝑓1(𝜀, 𝜀,̇ 𝛾, �̇�, ω) (2) 𝐹2 = −𝐹𝑟 cos 𝛾 + 𝐹𝑡 sin 𝛾 ≡ 𝑓2(𝜀, 𝜀,̇ 𝛾, �̇�, ω) (3) where f1 and f2 are pressure force components at inertial coordinates; fr and ft are the bearing forces in the rotating coordinate system (r, t); ω is the table 1. table caption data specification of the radial compressor and radial turbine at the design point parameter unit compressor turbine mass flow rate (ṁ) [kg/s] 0.34 0.34 rotor speed (ω) [rpm] 72,373 72,373 power (p) [kw] 40 80 efficiency (ηts) [-] 0.78 0.84 pressure ratio (pr) [-] 2.8 2.6 turbine inlet temperature [k] 1,173 number of blade rotor (zr) [-] 8/8 16 number of blade vane (zv) [-] 17 diameter rotor [mm] 105 128 axial length [mm] 41 42 high of rotor outlet (b2) [mm] 6.8 25 beta angle (beta2b) [°] -40 figure 1. radial compressor and turbine assembly modeling with turbo-shaft and bearing [10] m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 40 angular rotor velocity or rotor speed; 𝜀 and 𝜀̇ are the journal bearing relative eccentricity and the time change rate of the journal relative eccentricity; 𝛾 is the whirl velocity of the journal bearing. the equation above is utilized to calculate the transient non-linear bearing forces at every iteration time step. the solutions are from the damping coefficients, bearing stiffness, and other parameters [11]. the bearing stiffness coefficients kik on equation (4) and the bearing damping coefficients dik on equation (5) are defined from the static load (f0), radial bearing clearance (c), journal bearing dimensionless damping coefficients (𝛽𝑖𝑘), and the rotor speed: 𝑘𝑖𝑘 ≡ − 𝜕𝑓𝑖 𝜕𝑥𝑘 = 𝜅𝑖𝑘 𝐹0 𝑐 ; i; k = 1, 2 (4) 𝑑𝑖𝑘 ≡ − 𝜕𝑓𝑖 𝜕�̇�𝑘 = 𝛽𝑖𝑘 𝐹0 𝑐ω ; i; k = 1, 2 (5) in the present study, the rotordynamics in microturbine as mentioned above were developed and solved in the commercial tool gt-suite environment [12]. in gt-suite, the characteristics of turbo-shaft and rotor vibrations are defined in the frequency and time domain. in the frequency domain, the harmonic vibration has the same frequency of the rotor frequency ω. the frequency order is called 1x which is 𝜔 = ω [11][13]. meanwhile, in the time domain, the harmonic vibration has a time function of sine or cosine or 𝑥(𝑡) = 𝐴 sin(ω𝑡 + 𝜑) , where x(t) is the time amplitude of the vibration and 𝜑 is the phase in radian. figure 2 shows the microturbine rotor assembly model implemented in gt-suite environment to compute the rotordynamics phenomena and the effect of the journal bearing clearance. iii. results and discussions a. rotordynamics of rotor assembly on the design and off-design speed in this section, the rotordynamics simulations on the microturbine turbo-shaft with journal bearing and inner-outer bushing support are presented. the turbo-shaft runs at design speed 72 krpm and compared to the off-design speed operating conditions. figure 3 shows the dependency of the results upon the fast fourier transform (fft) on the input signal concerning the time domain for both compressor and turbine. the input signal fft represents superimposed vibration in the ydirection and the vibration response to the rotors [11]. it can be seen that in the turbine, the vibration is higher than in the compressor wheel. figure 2. radial compressor and turbine assembly modeling with turbo-shaft and bearing figure 3. the fast fourier transform (fft) on the input signal vs. time domain for compressor and turbine m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 41 figure 4 presents the influence of rotor speed on the tip displacements at the compressor and turbine concerning the time domain. the tip deflection or displacements on the rotor is in the y-direction with the transient response. five different speeds are considered, i.e. 52 krpm, 57 krpm, 65 krpm, 72 krpm (design speed), and 79 krpm. these represent 0.7 to 1.1 of the design speed. for the rotor speed of 52 krpm and 57 krpm (figures 4a and 4b), the tip deflection characteristics are similar. it can be seen that the rotor tip deflection or displacement is unstable at the beginning. the vibration starts at the initial position and growths exponentially with time, hence the vibration becomes unstable. the behaviour of vibration becomes stable after several times due to the decrease in the amplitude of the vibration in a short time (see figure 5). for instance, the maximum tip displacement at the stable region for both compressor and turbine are below 0.02 mm. figures 4b, 4c, and 4d reveal that there has been a gradual increase in the maximum tip displacement for compressor and turbine. the vibration characteristics of the rotors are similar from rotor speed 65 krpm to 79 krpm (figures 4c and 4d). the maximum tip displacement is between 0.05 mm to 0.07 mm, which is still at the safe operating conditions [14]. figure 4. prediction of the maximum tip displacement for compressor and turbine wheel at various turbo speed: (a) 52 krpm; (b) 57 krpm; (c) 65 krpm; (d) 72 krpm; (e) 79 krpm m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 42 figure 5 depicts a waterfall diagram of predicted non-linear turbo-shaft response at compressor and turbine. the waterfall diagram in figures 5a and 5b also expose the rotor mode shapes at a turbo-shaft from 52 krpm to 79 krpm. in most cases, the journal bearing system critical speeds are recognized on the crossing of the synchronous line 1x (𝜔 = ω) with each of the natural frequencies. for safety reasons, the design of journal bearing should avoid crossing the natural frequencies line. figures 5a and 5b show that the unbalance amplitude at synchronous line 1x is relatively small, which means that the journal bearing or turbo-shaft of the compressor and turbine wheel are running safely. meanwhile, the frequency of the journal bearing is much higher than the quasiresonance amplitude of the compressor and turbine wheel. the maximum amplitude is about 0.030 and 1300 hz for the maximum frequency. the characteristic resonance of linear vibration does not present in non-linear rotordynamics simulation [14]. therefore, only the maximum cycle of the compressor and turbine wheel response is developed at each turbo speed. b. effect of the journal bearing clearance the influence of the oil journal bearing clearance is discussed in this section. the turbo-shaft operates at the design speed of 72 krpm. five difference clearances are considered, that is 0.015 mm, 0.020 mm, 0.025 mm, 0.030 mm, and 0.035 mm. figure 6 displays the comparison of maximum tip displacement for both compressor and turbine wheel. similar to the previous section, the tip displacement of the rotor response is obtained through superimposing the harmonic unbalance vibration on the subsynchronous frequency components of the inner and outer oil journal bearing at the rotor. for the oil journal bearing figure 5. the non-linear rotordynamics prediction of the maximum amplitude for (a) compressor and (b) turbine wheel at various turbo speed in the frequency domain m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 43 clearance of 0.015 mm, the tip displacement increases and becomes unbalanced at the beginning time step simulation. the maximum displacement is about 0.04 mm (see figure 6a). furthermore, figure 6b shows that the vibration of the rotor response has sidebands displacement at the initial time step. in the end, the vibration response is diminished with the minimum displacement. however, the tip displacement trend is increased at the more significant journal bearing clearance, as shown in figure 6. comparison of maximum tip displacement at different journal bearing clearance for compressor and turbine wheel: (a) 0.015; (b) 0.020; (c) 0.025; (d) 0.030; (e) 0.035 m. arifin / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 38-44 44 figures 6c, 6d, and 6e. at the 0.035 mm clearance, the maximum displacement is about 0.09 mm. from figure 6 it is known that the ideal clearances for turbo-shaft microturbine are between 0.015 mm and 0.020 mm at the design point operation. to conclude, the turbomachinery components for csp system require a wider range of rotational speed and loading than conventional micro gas-turbine to maintain high efficiency due to fluctuation in dni daily operation [15]. iv. conclusion the rotordynamics characteristics of turbo-shaft microturbine based on parabolic dish solar concentrator were investigated under non-linear vibrations in the time and frequency domains. the model can predict a maximum tip displacement for compressor and turbine wheel at various speed. five different turbo speed values and journal bearing oil clearance were considered in the evaluations. this study used a fast fourier transform (fft) to represent the vibrations response to the rotor or wheel. this study shows that the maximum tip displacement occurs at higher turbo speed and larger bearing oil clearance. the results show that in the design turbo speed (72 krpm), the maximum tip displacement is still in reasonable conditions. acknowledgement the authors would like to acknowledge the ministry of finance republic of indonesia for the financial support through indonesia endowment fund for education (lpdp), insentif riset sistem inovasi nasional (insinas) kemenristek, and the institute of thermal turbomachinery and machinery laboratory (itsm) at the university of stuttgart for providing the computational support. declarations author contribution m. arifin as the contributor of this paper. author read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] m.d.j.m. guerrero-lemus r., “concentrated solar power,” in: renewable energies and co2, vol. 3. london: springer-verlag, 2013. [2] w.s.k. lovegrove, concentrating solar power technology, principles, developments and applications, woodhead publishing, 2012. [3] m. arifin, a. rajani, kusnadi, and t. d. atmaja, “modeling and performance analysis of a parallel solar hybrid micro gas turbine,” proceeding 2019 int. conf. sustain. energy eng. appl. innov. technol. towar. energy resilience, icseea 2019, pp. 62–68, 2019. [4] m. arifin, k. kusnadi, and r. i. pramana, “prediction performance map of radial compressor for system simulation,” proc. 6th int. conf. sustain. energy eng. appl. icseea 2018, pp. 51–56, 2019. [5] a.i.s.a. arroyo, m. mclorn, m. fabian, m. white, “rotordynamics of different shaft configurations for a 6 kw micro gas turbine for concentrated solar power,” asme turbo expo 2016 turbomach. tech. conf. expo., pp. 1–10, 2016. [6] i. chatzisavvas, “efficient thermohydrodynamic radial and thrust bearing modeling for transient rotor simulations,” phd thesis, darmstadt, tech. univ., 2018. [7] m.i. friswell, dynamics of rotating machines. cambridge university press, 2015. [8] p. koutsovasilis, “mode shape degeneration in linear rotor dynamics for turbocharger systems,” arch. appl. mech., vol. 87, no. 3, pp. 575–592, 2017. [9] i. chatzisavvas, “efficient thrust bearing model for highspeed rotordynamic applications,” in proceedings of the 9th iftomm international conference on rotor dynamics, 2015. [10] p. koutsovasilis, “automotive turbocharger rotordynamics: interaction of thrust and radial bearings in shaft motion simulation,” j. sound vib., vol. 455, pp. 413–429, 2019. [11] h. nguyen-schäfer, rotordynamics of automotive turbochargers, vol. 2. stuttgart: springer international publishing ag switzerland, 2015. [12] gamma technologies, “gt-suite, flow and mechanical theory manual,” 2019. [13] c.u. waldherr and d.m. vogt, “an extension of the classical subset of nominal modes method for the model order reduction of gyroscopic systems,” j. eng. gas turbines power, vol. 141, no. 5, pp. 1–8, 2019. [14] w.j. chen, “rotordynamics and bearing design of turbochargers,” mech. syst. signal process., vol. 29, pp. 77–89, 2012. [15] d. iaria, j. alzaili, a.i. sayma, “solar dish micro gas turbine technology for distributed power generation,” in sustainable energy technology and policies. green energy and technology, springer, singapore, 2018. https://doi.org/10.1007/978-1-4471-4385-7_7 https://doi.org/10.1007/978-1-4471-4385-7_7 https://doi.org/10.1007/978-1-4471-4385-7_7 https://doi.org/10.1533/9780857096173 https://doi.org/10.1533/9780857096173 https://doi.org/10.1533/9780857096173 https://doi.org/10.1109/icseea47812.2019.8938652 https://doi.org/10.1109/icseea47812.2019.8938652 https://doi.org/10.1109/icseea47812.2019.8938652 https://doi.org/10.1109/icseea47812.2019.8938652 https://doi.org/10.1109/icseea47812.2019.8938652 https://doi.org/10.1109/icseea.2018.8627087 https://doi.org/10.1109/icseea.2018.8627087 https://doi.org/10.1109/icseea.2018.8627087 https://doi.org/10.1109/icseea.2018.8627087 https://doi.org/10.1115/gt2016-56479 https://doi.org/10.1115/gt2016-56479 https://doi.org/10.1115/gt2016-56479 https://doi.org/10.1115/gt2016-56479 https://tuprints.ulb.tu-darmstadt.de/id/eprint/7780 https://tuprints.ulb.tu-darmstadt.de/id/eprint/7780 https://tuprints.ulb.tu-darmstadt.de/id/eprint/7780 https://doi.org/10.1017/cbo9780511780509 https://doi.org/10.1017/cbo9780511780509 https://doi.org/10.1007/s00419-016-1210-0 https://doi.org/10.1007/s00419-016-1210-0 https://doi.org/10.1007/s00419-016-1210-0 https://doi.org/10.1007/978-3-319-06590-8_79 https://doi.org/10.1007/978-3-319-06590-8_79 https://doi.org/10.1007/978-3-319-06590-8_79 https://doi.org/10.1016/j.jsv.2019.05.016 https://doi.org/10.1016/j.jsv.2019.05.016 https://doi.org/10.1016/j.jsv.2019.05.016 https://doi.org/10.1007/978-3-642-27518-0 https://doi.org/10.1007/978-3-642-27518-0 https://doi.org/10.1007/978-3-642-27518-0 https://www.gtisoft.com/ https://www.gtisoft.com/ https://doi.org/10.1115/1.4041117 https://doi.org/10.1115/1.4041117 https://doi.org/10.1115/1.4041117 https://doi.org/10.1115/1.4041117 https://doi.org/10.1016/j.ymssp.2011.07.025 https://doi.org/10.1016/j.ymssp.2011.07.025 https://doi.org/10.1016/j.ymssp.2011.07.025 https://doi.org/10.1007/978-981-10-7188-1_5 https://doi.org/10.1007/978-981-10-7188-1_5 https://doi.org/10.1007/978-981-10-7188-1_5 https://doi.org/10.1007/978-981-10-7188-1_5 introduction ii. materials and methods iii. results and discussions a. rotordynamics of rotor assembly on the design and off-design speed b. effect of the journal bearing clearance iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.45-50 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology nofriyani a, *, robeth viktoria manurung b, aminuddin debataraja c, indra dwisaputra a a electrical engineering department, politeknik manufaktur negeri bangka belitung kawasan industri air katung sungailiat bangka, bangka-belitung, 33211 indonesia b research center for electronics and telecommunications, indonesian institute of sciences jl. cisitu, sangkuriang, bandung, west java, 40135 indonesia c electrical engineering department, politeknik negeri jakarta jl. prof. dr. g.a. siwabessy, kukusan, beji, depok, west java, 16424 indonesia received 15 april 2021; accepted 26 june 2021; published online 31 july 2021 abstract this study describes the development of chemical sensors to detect polypyrrole (ppy) based phosphate sensors in doped di-ammonium hydrogen phosphate (dap) with thick film technology (tft). manufacturing screen-printed carbon electrode (spce) with thick film uses alumina substrate provided a more portable, miniature, inexpensive, and reduced use of samples and reagents. polymer polypyrrole and di-ammonium hydrogen phosphate as sensitive membranes are electrodeposition on carbon electrodes. characterization has been conducted to see the electrode morphology in scanning electron microscopy (sem) test, which showed that sensitive material particles were distributed evenly on the surface of the sample and spherical. the energy dispersive spectroscopy (eds) experiment results showed the atomic composition respectively carbon 86.95 %, nitrogen 6.94 %, oxygen 5.9 %, and phosphate 0.21 %, which were exposed to the electrode. the performance test of electrodes with a phosphate standard solution has proceeded at a concentration between 5 to 100 mg/l, which is measured using the galvanostatic method. the voltage range was from 0.252 to 0.957 v with r2 at approximately 90.265 %. the results of sensor performance were concluded that the electrode was able to detect phosphate ions. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: carbon electrode; electropolimerization; phosphate; polymer polypyrrole; thick film. i. introduction excessive use of fertilizers on agricultural land causes the risk of environmental pollution, degradation of soil structure, and decreased groundwater levels. monitoring and analysis of precision farming soil are needed to monitor the main nutrient contents such as nitrogen (n), phosphate (p), or potassium (k) on agricultural land before farming activities are carried out [1]. therefore, instrumentation devices are needed to detect nutrient content on agricultural soil. in previous studies, sensor design and fabrication studies for precision farming. sensor terminology is strongly influenced by the substrate, the conductivity of the electrode, and the sensitive material [2]. microelectromechanical system (mems) technology is carried out to miniaturize the sensor, portable size, and reduce the consumption of the sample and reagent integrated into one piece of substrate. the substrate used for the phosphate sensor is a polyester film, polyvinyl chloride (pvc), filter paper, and carbon fiber [3][4][5]. the materials used for electrodes are gold paste, silver, cobalt, black carbon nanoparticles, graphite, and lead [6][7][8]. sensitive polymer polypyrrole (ppy) membrane has been used for biosensors, electrochemical sensors, protein sensors, glucose biosensors, clofibric acid sensors, non-enzyme sensors, and nitrate selectivity sensors [9][10][11]. * corresponding author. tel: +62-823-3729-1941 e-mail address: nofriyani03@gmail.com https://dx.doi.org/10.14203/j.mev.2021.v12.45-50 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.45-50 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.45-50&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ nofriyani et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 46 according to the previous literature, this study will be carried out on the development of phosphate ion sensor fabrication of thick film technology. sensitive membrane sensors based on polymer polypyrrole (ppy) film layer are doped with a solution of di-ammonium hydrogen phosphate (dap) on a carbon electrode screened-printing onto the aluminum substrate. the study was conducted to improve the performance of electrodes to detect phosphate ions in precision farming. this research focuses on the sensitive membrane used. it is printed on carbon electrodes using an alumina substrate with ppy membrane and dap using thick-film technology. the phosphate ion sensor consists of three electrodes, the working electrode, the counter electrode, and the reference electrode. this study focuses on fabricating precision farming sensors that are specifically aimed to detect ion phosphate nutrients. the morphological characteristics testing and composition of electrode material were conducted using sem and eds [12]. the electrode performance testing is implemented to obtain a good sensor performance (sensitivity, limit detection, response time, and linearity). ii. materials and methods a. equipment and reagent supporting equipment are used in this study are screen printing, screen maker machine, printing machine, firing machine, oven, stative, beaker glass, micropipette, magnetic stirrer, nitrogen tube, power supply, accumet solid-state half cell ise (fisherbrand), multimeters (sanwa pc-550), computers, sem and eds (su3500). materials used in this study are alumina substrate (al2o3), silver | silver chloride (ag | agcl) conductor paste (ferro), platinized carbon paste (c2000511d1), protective film, ulana 133, ulano film, deionized water with 17 mω resi st i vi ties, 98 % grade pyrrole reagent (aldrich), ammonium hydrogen phosphate (merck), aluminum oxide (merck), phosphate standard solution (merck), and potassium chloride (kcl). b. fabrication of electrode the electrode design is needed to determine the pattern, dimensions, and electrode layout that use thick film technology with a screen-printing technique that aims to determine the effect of the path width on the sensor sensitivity. the electrode design is made by using corel draw software. the thick film technology process consists of screen making, electrode printing, drying, firing, pin installation, and packaging. as the first stages, the reference electrode and conjunction pad are printed on the alumina substrate using paste (ag | agcl). then it was dried in an oven to minimize the liquid that is bound to the electrode. the process is continued by gradually firing with a temperature of 0 to 800 °c for 30 minutes in a furnace firing sinters machine. the next stage is printing the working electrodes and counter electrodes using platinized carbon paste, then dried material with a temperature of 0 to 120 °c for 15 minutes to bind the exposed carbon to the alumina substrate. then the packaging is carried out, so the electrodes are ready to use. the configuration of electrodes fabrication stages is shown in figure 1. c. electrodeposition of polypyrrole doped dap electrodeposition of pyrrole doped with dap onto carbon was performed by an electrochemical process. in the first step, polypyrrole must be purified with powdered alumina oxide in a dark room to remove the substances that were oxidized with the air. amperometric used as a constant voltage source for electrodeposition. the initial polymerization solution consisted of ppy (c4h4nh) [1m] doped with a solution of dap ((nh4)2hpo4) [0.1m] dissolved with deionized water. the electrodeposition with the amperometric method is implemented by adjusting the constant voltage source of 1 v connected to the carbon electrode and the platinum plate anode so that an oxidation reaction occurs to the sensitive membrane solution by flowing purging with nitrogen gas experiment. the deposition of the carbon electrode is executed for 30 minutes by measuring the changes in current during the electropolymerization process. freshly prepare electrodeposition sample, the electrode then must be immersed in a solution ((nh4)2hpo4) [0.01m] for 24 hours in a dark room. d. testing performance sensor sensor performance testing was conducted using a potentiostat to control the electrodes and measure the experiment electroanalytical (figure 2). the previous research on measurement electrodes used the amperometric method [4]. the galvanostatic was used as a constant current source set at 0.7 v, with a resistance of 10 kω as input to get the response output voltage. the electrodes are connected to the conditioning signal circuit, and then it is dipped into a phosphate standard solution (po4 3-) with a concentration of 5 mg/l, 25 mg/l, 50 mg/l, and 100 mg/l. the multimeter is connected to the sensor output to measure the output voltage, while the acquisition data is transferred to the computer. the testing is repeated five times in 10 minutes for each of test sample. figure 1. screen printing electrode nofriyani et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 47 iii. results and discussions a. electrodes of sensor the phosphate sensor consists of three electrodes, the working electrode, the reference electrode, and the counter electrode. on 50 × 50 mm substrate alumina, the reference electrode was printed with a size of 21.21 × 3.5 mm and the conjunction pad sized on 3.95 × 1.5 mm. the carbon electrodes in a comb shape were sized on 21.31 × 2.28 mm. the electrode prototype to detect the phosphate fabricated ion by using thick-film technology is shown in figure 3. b. the morphological and composition material testing the morphological characteristics testing was implemented by the scanning electron microscope (sem) method. the 'before and after' of carbon electrode morphology is being coated with a polymer-sensitive polypyrrole membrane which is doped with ((nh4)2 hpo4) solution is shown in figure 4. the differences of topographic surface in the before and after electrodes electropolymerization can be seen according to the morphological testing using sem. the analyzed surface polypyrrole has using sem to observe the morphology of ionsensitive membrane [13]. the coated surface of the sensitive membrane is more evenly distributed than before. the particles have significantly shown dissimilar. the polymerized electrodes were seen at a magnification of 20,000 secondary electrons with 10 kv. the morphology sample with a size of 2 µm showed that spherical particles were distributed evenly on the electrode surface. after that, energy dispersive spectroscopy (eds) was tested (shown in table 1) to determine the atom composition at the electropolymerized electrodes. the eds results showed the composition of atoms, namely carbon at 86.95 %, nitrogen at 6.94 %, oxygen at 5.9 %, and phosphate at 0.21 %. based on the percentage, the phosphate atomic elements are greatly small because they are comparable with the concentration of the used solution ((nh4)2hpo4) of 0.1 mol/l. c. electrodeposition testing measurement of current response by amperometric method on electrodeposition shows the occurrence of ppy and dap as sensitive membrane coating on carbon electrodes. the electrode electrodeposition experiment is shown in figure 5. the current measurement results for 30 minutes showed the output current response in the range of 0.03 to 0.2 ma with the presence of a stable current change during electropolymerization. in addition, there was an accretion of sensitive membranes on carbon electrodes. figure 2. testing performance sensor reference electrode working electrode cou nter electrode alu mina subs trate pad figure 3. prototype electrode (a) (b) figure 4. sem photograph. (a) electrode carbon before electropolimerization; (b) electrode carbon and ppy after electropolimerization nofriyani et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 48 d. electrode stability the reference electrode of the ag | agcl testing was implemented to see the stability of the electrode performance. as a result, the electrode has been the stability of the reference electrode [13]. the testing is executed by comparing the reference electrodes with commercial, which is tested in a kcl [3m] solution. the average voltage of the reference electrode test obtained the output at 6.8 to 7.4 mv. the reference electrode experiment is shown in figure 6. the test is executed for 30 minutes. the experiment shows that the reference electrode voltage is relatively stable. e. sensor performance testing the output response of performance ion sensor using phosphate solution concentration is 0.252 v to 0.957 v, which indicates that the higher the phosphate concentration is detected, the output voltage is increased. the peak intensity was increased with the increasing phosphate concentration shows the sensor's better response with different concentrations of phosphate [6]. the discussed research has been shown the limit of detection ion phosphate based on different conductive electrodes [6][7][14]. this study's limit of detection ion phosphate is 5 mg/l with a linear range of 5 to 100 mg/l phosphate solution. the result of the output voltage chart to the solution concentration obtained a sensitivity of 0.008 v for every addition concentration and regression value (r2 = 90.265 %) which shows a linear response. furthermore, measurement performance at the phosphate sensor resulted has shown that response linear [13][15]. therefore, the output voltage at the electrode test can be used as a sensor to detect phosphate ions. the output response sensor performance of the average voltage from the electrode is shown in figure 7. improvement is achieved result compared to previous research, the analytic parameter sensor phosphate detection is shown table 2. table 1. result of eds electrodes experiment element element composition weight percent (wt. %) atomic percent (at. %) data error (%)* net interpret element the pure element standard (k-ratio) atomic number corection (z) atomic number corection (a) secondary fluorescence correctiion (f) c k 84.10 86.9 3.5 24.95 0.680 1.01 0.80 1 n k 7.82 6.9 25.1 28.40 0.005 0.98 0.06 1 o k 7.59 5.9 17.8 68.90 0.007 0.96 0.09 1 p k 0.53 0.2 4.2 56.80 0.004 0.82 0.98 1 *data error is comparison both ezaf (standardlessbased correction factor nation) and p/b (peak to background ratio element) method figure 5. output response of electrodeposition electrodes 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20 0.21 00 :0 0. 0 00 :4 5. 5 01 :3 1. 0 02 :1 6. 5 03 :0 2. 0 03 :4 7. 5 04 :3 3. 0 05 :1 8. 5 06 :0 4. 0 06 :4 9. 5 07 :3 5. 0 08 :2 0. 5 09 :0 6. 0 09 :5 1. 5 10 :3 7. 0 11 :2 2. 5 12 :0 8. 0 12 :5 3. 5 13 :3 9. 0 14 :2 4. 5 15 :1 0. 0 15 :5 5. 5 16 :4 1. 0 17 :2 6. 5 18 :1 2. 0 18 :5 7. 5 19 :4 3. 0 20 :2 8. 5 21 :1 4. 0 21 :5 9. 5 22 :4 5. 0 23 :3 0. 5 24 :1 6. 0 25 :0 1. 5 25 :4 7. 0 26 :3 2. 5 27 :1 8. 0 28 :0 3. 5 28 :4 9. 0 29 :3 4. 5 cu rr en t ( i) m a time (minutes) figure 6. output response stability reference electrode 6.8 6.9 7 7.1 7.2 7.3 7.4 7.5 0 5 10 15 20 25 30 vo lta ge (m v) time (minutes) nofriyani et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 49 iv. conclusion sensitive membrane coating that uses polymer polypyrrole doped with di-ammonium phosphate was successfully implemented using the electropolymerization method. the occurrence of electropolymerization is shown by the output current flowing in the electrode ranging from 0.2 to 0.03 ma. the sensitive membrane layer in the sem test shows that it is evenly distributed on the surface of the electrode and spherical. according to the eds test, it showed the percentage of each atom those are carbon (c) 86.95 %, nitrogen (n) 6.94 %, oxygen (o) 5.9 %, and phosphate (p) 0.21 %. the stability test of reference versus commercial electrodes shows a stable voltage output in the range of 6.8 to 7.4 mv. the performance testing at a concentration of 5 to 100 mg/l phosphate standard solution shows the output voltage ranges from 0.252 v to 0.957 v, with a sensitivity of 0.008 v for every addition concentration and linear regression performance of sensor ion phosphate (r2 = 90.267 %). according to the testing, as the results, the electrode is capable of detecting the phosphate ion. acknowledgment the author would like to say thank you very much to the researcher at the research center for electronics and telecommunication, indonesian institute of sciences (lipi), bandung for supporting all of these study activities. declarations author contribution norfriyani contributed as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] v. i. adamchuk, j. w. hummel, m. t. morgan, and s. k. upadhyaya, “on-the-go soil sensors for precision agriculture,” comput. electron. agric., vol. 44, no. 1, pp. 71–91, jul. 2004. [2] l. tymecki, s. glab, and r. koncki, “miniaturized, planar ionselective electrodes fabricated by means of thick-film technology,” sensors, vol. 6, no. 4, pp. 390–396, apr. 2006. [3] d. pathania, m. thakur, g. sharma, and a. k. mishra, “tin (iv) phosphate/poly(gelatin-cl-alginate) nanocomposite: photocatalysis and fabrication of potentiometric sensor forpb (ii),” figure 7. output response performance sensorparticles table 2. comparison of analytic parameter phosphate detection with a different electrochemical sensor no electrodes composition method linear range limit of detection ref 1 cbnps phosphate and molybdate amperometric 6 to 20 µm 6 µm [4] 2 cbnps-spes molyb date phosphate cyclic voltametry 0.5 to 100 µm 0.1 µm [6] 3 paper cb-spe molyb date, h2so4, and kcl cyclic voltametry 1 to 300 µm 4 µm [5] 4 spce amt/agnws cyclic voltametry 5 µm to 1mm 3 µm [14] 5 spce ppy, dap and water de-ionized galvanostatic 5 to 100 mg/l 5 mg/l this work 0.252 0.274 0.372 0.957 y = 0.008x + 0.1168 r² = 0.9027 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 0 10 20 30 40 50 60 70 80 90 100 vo lta ge (v ol t) phosphate solution (mg/l) voltage linear (voltage) https://mev.lipi.go.id/ https://doi.org/10.1016/j.compag.2004.03.002 https://doi.org/10.1016/j.compag.2004.03.002 https://doi.org/10.1016/j.compag.2004.03.002 https://doi.org/10.3390/s6040390 https://doi.org/10.3390/s6040390 https://doi.org/10.3390/s6040390 https://doi.org/10.1016/j.mtcomm.2018.01.005 https://doi.org/10.1016/j.mtcomm.2018.01.005 https://doi.org/10.1016/j.mtcomm.2018.01.005 nofriyani et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 45-50 50 mater. today commun., vol. 14, no. november 2017, pp. 282– 293, mar. 2018. [4] d. talarico, s. cinti, f. arduini, a. amine, d. moscone, and g. palleschi, “phosphate detection through a cost-effective carbon black nanoparticle-modified screen-printed electrode embedded in a continuous flow system,” environ. sci. technol., vol. 49, no. 13, pp. 7934–7939, jul. 2015. [5] s. cinti, d. talarico, g. palleschi, d. moscone, and f. arduini, “analytica chimica acta novel reagentless paper-based screen-printed electrochemical sensor to detect phosphate,” anal. chim. acta, vol. 919, pp. 78–84, 2016. [6] d. talarico, f. arduini, a. amine, d. moscone, and g. palleschi, “screen-printed electrode modified with carbon black nanoparticles for phosphate detection by measuring the electroactive phosphomolybdate complex,” talanta, vol. 141, pp. 267–272, aug. 2015. [7] s. shahrokhian and e. asadian, “electrochemical determination of l-dopa in the presence of ascorbic acid on the surface of the glassy carbon electrode modified by a bilayer of multi-walled carbon nanotube and poly-pyrrole doped with tiron,” j. electroanal. chem., vol. 636, no. 1–2, pp. 40–46, nov. 2009. [8] k. xu, y. kitazumi, k. kano, and o. shirai, “phosphate ion sensor using a cobalt phosphate coated cobalt electrode,” electrochim. acta, vol. 282, pp. 242–246, aug. 2018. [9] m. boota, b. anasori, c. voigt, m. zhao, m. w. barsoum, and y. gogotsi, “pseudocapacitive electrodes produced by oxidantfree polymerization of pyrrole between the layers of 2d titanium carbide (mxene),” adv. mater., vol. 28, no. 7, pp. 1517–1522, feb. 2016. [10] u. baig, r. a. k. rao, a. a. khan, m. m. sanagi, and m. a. gondal, “removal of carcinogenic hexavalent chromium from aqueous solutions using newly synthesized and characterized polypyrrole–titanium(iv)phosphate nanocomposite,” chem. eng. j., vol. 280, no. iv, pp. 494–504, nov. 2015. [11] xiaochen wang, j. church, woo hyoung lee, and h. j. cho, “phosphate sensors based on co-cu electrodes fabricated with a sacrificial glass fiber paper template,” in 2015 ieee sensors, nov. 2015, pp. 1–4. [12] w. zhou, r. apkarian, z. l. wang, and d. joy, “fundamentals of scanning electron microscopy (sem),” in scanning microscopy for nanotechnology, new york, ny: springer new york, 2006, pp. 1–40. [13] r. v. manurung, t. m. s. soegandhi, and hiskia, “electropolymerization of pyrrole in aqueous solution on carbon electrodes for ion sensor,” in proc. of international conference on materials engineering (icme), 2010, no. november 2010, pp. 0–3. [14] m. f. kabir, m. t. rahman, a. gurung, and q. qiao, “electrochemical phosphate sensors using silver nanowires treated screen printed electrodes,” ieee sens. j., vol. 18, no. 9, pp. 3480–3485, may 2018. [15] s. berchmans, r. karthikeyan, s. gupta, g. e. j. poinern, t. b. issa, and p. singh, “glassy carbon electrode modified with hybrid films containing inorganic molybdate anions trapped in organic matrices of chitosan and ionic liquid for the amperometric sensing of phosphate at neutral ph,” sensors actuators b chem., vol. 160, no. 1, pp. 1224–1231, dec. 2011. https://doi.org/10.1016/j.mtcomm.2018.01.005 https://doi.org/10.1016/j.mtcomm.2018.01.005 https://doi.org/10.1021/acs.est.5b00218 https://doi.org/10.1021/acs.est.5b00218 https://doi.org/10.1021/acs.est.5b00218 https://doi.org/10.1021/acs.est.5b00218 https://doi.org/10.1021/acs.est.5b00218 https://doi.org/10.1016/j.aca.2016.03.011 https://doi.org/10.1016/j.aca.2016.03.011 https://doi.org/10.1016/j.aca.2016.03.011 https://doi.org/10.1016/j.aca.2016.03.011 https://doi.org/10.1016/j.talanta.2015.04.006 https://doi.org/10.1016/j.talanta.2015.04.006 https://doi.org/10.1016/j.talanta.2015.04.006 https://doi.org/10.1016/j.talanta.2015.04.006 https://doi.org/10.1016/j.talanta.2015.04.006 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.jelechem.2009.09.010 https://doi.org/10.1016/j.electacta.2018.06.021 https://doi.org/10.1016/j.electacta.2018.06.021 https://doi.org/10.1016/j.electacta.2018.06.021 https://doi.org/10.1002/adma.201504705 https://doi.org/10.1002/adma.201504705 https://doi.org/10.1002/adma.201504705 https://doi.org/10.1002/adma.201504705 https://doi.org/10.1002/adma.201504705 https://doi.org/10.1016/j.cej.2015.06.031 https://doi.org/10.1016/j.cej.2015.06.031 https://doi.org/10.1016/j.cej.2015.06.031 https://doi.org/10.1016/j.cej.2015.06.031 https://doi.org/10.1016/j.cej.2015.06.031 https://doi.org/10.1109/icsens.2015.7370475 https://doi.org/10.1109/icsens.2015.7370475 https://doi.org/10.1109/icsens.2015.7370475 https://doi.org/10.1109/icsens.2015.7370475 https://doi.org/10.1007/978-0-387-39620-0_1 https://doi.org/10.1007/978-0-387-39620-0_1 https://doi.org/10.1007/978-0-387-39620-0_1 https://doi.org/10.1007/978-0-387-39620-0_1 https://www.researchgate.net/publication/236361860_electropolymerization_of_pyrrole_in_aqueous_solution_on_carbon_electrodes_for_ion_sensor https://www.researchgate.net/publication/236361860_electropolymerization_of_pyrrole_in_aqueous_solution_on_carbon_electrodes_for_ion_sensor https://www.researchgate.net/publication/236361860_electropolymerization_of_pyrrole_in_aqueous_solution_on_carbon_electrodes_for_ion_sensor https://www.researchgate.net/publication/236361860_electropolymerization_of_pyrrole_in_aqueous_solution_on_carbon_electrodes_for_ion_sensor https://www.researchgate.net/publication/236361860_electropolymerization_of_pyrrole_in_aqueous_solution_on_carbon_electrodes_for_ion_sensor https://doi.org/10.1109/jsen.2018.2808163 https://doi.org/10.1109/jsen.2018.2808163 https://doi.org/10.1109/jsen.2018.2808163 https://doi.org/10.1109/jsen.2018.2808163 https://doi.org/10.1016/j.snb.2011.09.052 https://doi.org/10.1016/j.snb.2011.09.052 https://doi.org/10.1016/j.snb.2011.09.052 https://doi.org/10.1016/j.snb.2011.09.052 https://doi.org/10.1016/j.snb.2011.09.052 https://doi.org/10.1016/j.snb.2011.09.052 introduction ii. materials and methods a. equipment and reagent b. fabrication of electrode c. electrodeposition of polypyrrole doped dap d. testing performance sensor iii. results and discussions a. electrodes of sensor b. the morphological and composition material testing c. electrodeposition testing d. electrode stability e. sensor performance testing iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.15-23 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: m.z. romdlony et al., “design and application of models reference adaptive control (mrac) on ball and beam,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 15-23, july 2022. design and application of models reference adaptive control (mrac) on ball and beam muhammad zakiyullah romdlony a, muhammad ridho rosa a, *, edwin muhammad puji syamsudin a, bambang riyanto trilaksono b, agung surya wibowo a, c a school of electrical engineering, telkom university jl. telekomunikasi terusan buah batu, bandung, 40257, indonesia b school of electrical engineering and informatics, bandung institute of technology jl. ganesha, bandung, 40132, indonesia c department of electronics engineering, nscl laboratory, jeonbuk national university 567 baekje-daero, deokjin-gu, jeonju-si, jeollabuk-do, south korea received 29 september 2021; revised 29 november 2021; accepted 8 december 2021; published online 29 july 2022 abstract this paper presents the implementation of an adaptive control approach to the ball and beam system (bbs). the dynamics of a bbs are non-linear, and in the implementation, the uncertainty of the system's parameters may occur. in this research, the linear state-feedback model reference adaptive control (mrac) is used to synchronize the states of the bbs with the states of the given reference model. this research investigates the performance of the mrac method for a linear system that is applied to a non-linear system or bbs. in order to get a faster states convergence response, we define the initial condition of the feedback gains. in addition, the feedback gains are limited to get less oscillation response. the results show the error convergence is improved for the different sets of the sinusoidal reference signal for the mrac with modified feedback gains. the ball position convergence improvement of mrac with modified feedback gains for sinusoidal reference with an amplitude of 0.25, 0.5, and 0.75 are 35.1 %, 36 %, and 52.4 %, respectively. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: model reference adaptive control; modified feedback gains; ball and beam system. i. introduction in designing the control of a system, one can use the simulation and experiment to see the effectiveness of the proposed method. however, this approach may cost a lot due to the miscalculation in the control system design. hardware in-the-loop (hil) is a simulation technique performed by combining hardware and software in the process [1]. implementing hil will facilitate the testing process and reduce the level of errors or failures that occur as well as the costs required in the design of the control system [2]. in this research, we use a real plant bbs and the controller in matlab, which is the opposite of the hil scheme. using this approach, one can directly implement the proposed control method that is designed in matlab to a real plant. adaptive control is an advanced control method with parameter adjustments that can regulate the states or output of the uncertain system to track a certain value [3]. in adaptive control, the unknown system is expected to converge its states or output to reference model states or output. the model reference adaptive control (mrac) makes the unknown system dynamics similar to the reference model dynamics [4][5]. the mrac can be categorized into two types based on how its estimates the unknown parameters, indirect and direct mrac [6][7]. the author uses the statefeedback direct mrac control method with modified feedback gains to get fast adaptation. recent research on fast adaptation in adaptive control can be found in [8]. the bbs is one of the most widely used examples of control systems application in control engineering. the primary purpose of bbs is to track the ball to the commanded position by designing a particular * corresponding author. phone: +62-81802228261 e-mail address: mridhorosa@telkomuniversity.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.15-23 https://dx.doi.org/10.14203/j.mev.2022.v13.15-23 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2022.v13.15-23 https://dx.doi.org/10.14203/j.mev.2022.v13.15-23 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.15-23&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 16 control system [9]. this research uses the direct method mrac for a linear system that is implemented to bbs, a non-linear system. in other studies, various adaptive methods for bbs systems have been carried out. the control for the ball and beam system that combines the conventional dynamic surface control and the adaptive fuzzy scheme is proposed for the equilibrium balance of the ball [10]. there are also designing a model reference adaptive control system using the mit rule to control a ball and beam system so the plant could track the reference model [11]. the comparison between the integer and the fractional controller for bbs has been discussed and tested in [12]. it is known that a mechatronic system has limited control input due to actuator limitations. the parameter projection algorithm is used to solve the control saturation that may lead to undesirable results in adaptive controllers [13]. compared with most adaptive control of bbs literature, this work shows the effectiveness of direct state-feedback mrac both in simulation and in an experiment as a real-time controller of the bbs. in addition, we proposed predefined feedback gains to have a faster convergence rate and feedback gains saturation to get a less oscillated response shown by a small state error value. ii. materials and methods a. ball and beam system the bbs objective is to keep the ball's position in the desired location by connecting the beam to a servo motor. the ball's position is determined from the edge of the beam. the bbs configuration can be seen in figure 1. the motion of the ball can be found by using newton’s law that satisfies the following equation (1) 𝑚𝑚 sin 𝛼 − 𝐹𝑓 = 𝑚�̈� (1) where 𝐹𝑓 = 𝑗𝑏 𝑅2 �̈� is the frictional force, 𝑗𝑏 is the moment of inertia of the ball, and 𝛼 is the deflection of the beam. here we are assuming that 𝛼 is very small. thus we have linearized bbs motion in equation (2) 𝑚𝑚 𝛼 − 𝑗𝑏 𝑅2 �̈� = 𝑚�̈� (2) it is known that 𝛼 = 𝑑 𝐿 𝜃 , so that we have the following bbs dynamics equation (3) �𝑗𝑏 𝑅2 + 𝑚��̈� = 𝑚𝑚 𝑑 𝐿 θ (3) using the differential equation in equation (3), the dynamics of the second-order bbs modeling system in the state-space form can be defined as equation (4) ��̇� �̈� � = �0 1 0 0 �� 𝑟 �̇�� + � 0 𝑚𝑚𝑑 𝐿� 𝐽 𝑅2 +𝑚� �𝜃 (4) where �̇� is velocity of the ball and �̈� is acceleration of the ball. b. model reference adaptive control (mrac) the model reference adaptive control (mrac) is one of the adaptive control methods which aims to solve control problems with limited parameters to compensate for unknown system parameters by adapting the characteristics of the stable reference model. thus the system has the same characteristics similar to the reference model. in this study, direct mrac was used [14]. figure 2 shows the structure of the direct mrac. in direct state-feedback mrac, the following equations are used: figure 1. ball and beam dynamics, where m is ball mass, 𝑀 is rod mass, 𝑑 is offset arm length, 𝑚 is gravitational acceleration, 𝑅 is ball radius, 𝑟 is ball position, 𝜃 is angle of servo, and l is length beam figure 2. direct state-feedback mrac m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 17 unknown system using equation (5) �̇� = 𝐴𝑥 + 𝐵𝐵 (5) reference model using equation (6) �̇�𝑚 = 𝐴𝑚𝑥𝑚 + 𝐵𝑚𝑟 (6) lyapunov equation using equation (7) 𝐴𝑚′ 𝑃 + 𝑃𝐴𝑚 = −𝑄, 𝑄 > 0 (7) adaptive laws using equation (8) and (9) 𝑘�̇ = 𝛾1𝐵′𝑚𝑃𝑃(𝑥 − 𝑥𝑚)𝑥′sgn(𝑙∗) (8) 𝑙̇ = −𝛾2𝐵′𝑚𝑃𝑃(𝑥 − 𝑥𝑚)𝑟 sgn(𝑙∗) (9) control law using equation (10) 𝐵 = −𝑘𝑥 + 𝑙𝑟 (10) where 𝐴 is state matrix of unknown system, 𝐴𝑚 is state matrix of model reference, 𝐵 is input matrix of unknown system, 𝐵𝑚 is input matrix of model reference, r is input reference, u is control law, x is system’s states, 𝑥𝑚 is reference model’s states, 𝑄 & 𝑃 is matrix positive definite, 𝑃 is error in state feedback, 𝛾1 & 𝛾2 is adaptive gains, and 𝑘 & 𝑙 is feedback gains. c. system setup unlike the standard hardware in-the-loop (hil) scheme that uses a real controller to control the virtual system, we proposed the opposite of the hil scheme. in this research, the controller is matlab, and the system/bbs is a real plant. figure 3 shows the detailed system block diagram proposed in this research. the following is an explanation of the block diagram in figure 3: • the initial condition is given by the user as an initial state of the bbs in simulink matlab. • the initial information is processed in simulink matlab, in which mrac control is designed. • the resulting control signal is sent to the ball and beam system via arduino mega. then the servo motor will move the beam according to the control signal command. • the states response from the bbs is measured using an infrared sensor and sent back to matlab via arduino uno. the results are the states of the bbs, the position and the speed of the ball. • the ball moves on the beam according to the given control and adapts the reference model that was designed previously. • this process will continue until the simulink running time finish. d. system flowchart the system starts by initializing its parameters and adjusting the beam's position in its equilibrium state. after the setup has been set, we run the program that triggers the infrared sensor to detect the ball's position. the measured states are used as the inputs for the mrac besides the reference signal. the adaptive laws (8) and (9) will adaptively calculate the feedback gain. the output of the mrac or the control law will be sent to the servo motor. figure 4 shows the diagram of the entire bbs system. e. state feedback direct mrac setup the bbs parameters are defined in matlab to facilitate the simulation of the bbs. the state-space modeling of bbs is designed in simulink, where the bbs parameters are defined as follows: • m = 0.148 kg • g = 9.8 m/s2 • l = 0.35 m then the state-space form of the bbs system in equation (4) can be rewritten in equation (11) ��̇� �̈� � = �0 1 0 0 �� 𝑟 �̇�� + � 0 0.75 �𝜃 (11) and the stable model reference dynamics in the state-space form is defined as equation (12) �̇�𝑚 = � 0 1 −0.1 −0.2 �� 𝑥1𝑚 𝑥2𝑚 � + �0 1 �𝑟 (12) equation (12) is the reference model dynamics where the poles are on the left half plane and located near the origin. we used the adaptive law in equations (8) and (9), where𝛾1 = � 0.00025 0.0025 � , 𝛾2 = [−0.0025], and q = �1 0 0 1 �. figure 3. block diagram system m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 18 iii. results and discussions a. state feedback direct mrac on ball and beam system experiment first, we define the initial ball position at 17.5 cm from the edge of the beam, the sinusoidal frequency is 0.005 rad/sec, the sinusoidal bias is 1.75, and the simulink run time is 10,000 seconds. the responses based on the simulation and experiment of the proposed mrac design for bbs can be seen in figure 5. in the experiment (blue line), the state error between simulation and experiment is 7.65 % for an amplitude of 0.25, 13.41 % for an amplitude of 0.5, and 15.14 % for an amplitude of 0.75. it can be seen in figure 6 that the states of the bbs can converge to the states of the model reference with small errors at different timescales marked by dotted lines. therefore, we can take the values the feedback gains, 𝑘 and 𝑙, at that time range as the initial and saturation values. b. the influence of the initial definition and saturation value on the bbs system from the previous results, we get the information to define the initial value and the saturation value of the feedback gains 𝑘 and 𝑙. for sinusoidal reference signal with an amplitude of 0.25, we have 𝑘1 ∈ [5,10] , 𝑘2 ∈ [50,100], and 𝑙 ∈ [40,80]. for sinusoidal reference signal with an amplitude of 0.5, we have 𝑘1 ∈ [8,10], 𝑘2 ∈ [35,98], and 𝑙 ∈ [40,80]. for sinusoidal reference signal with an amplitude of 0.75, we have 𝑘1 ∈ [5,12], 𝑘2 ∈ [40,140], and 𝑙 ∈ [40,100]. the responses, simulation and experiment, of the proposed mrac with modified feedback gains 𝑘 and 𝑙 can be seen in figure 6. the yellow signal color indicates the reference signal, the blue color indicates the bbs experimental signal, and the red dotted line indicates the simulation signal. in the experiment (blue line), the states error between simulation and experiment is 4.97 % for an amplitude of 0.25, 8.57 % for an amplitude of 0.5, and 7.21 % for an amplitude of 0.75. table 1 shows the state error (error position of the ball) value before and after we define the initial and the saturation values of the feedback gains 𝑘 and 𝑙. it can be concluded that the modified feedback gains 𝑘 and 𝑙 decreased the error value by 2.68 % in the case of sinusoidal with an amplitude of 0.25, 4.84 % in the case of sinusoidal with an amplitude of 0.5, and 7.93 % in the case of sinusoidal with an amplitude of 0.75. figure 7 shows the comparison of the ball position when using the mrac with modified feedback gains and standard mrac. table 2 shows the performance improvement in terms of ball position error after the modification of the initial and the saturation values of feedback gains 𝑘 and 𝑙. it can be concluded that the modified feedback gains 𝑘 and 𝑙 gives the biggest improvement in terms of ball position error when the sinusoidal amplitude is 0.75. the smaller amplitude gives a lower performance improvement. figure 4. bbs flowchart table 1. comparison of the difference of ball position error in the experiment amplitude 𝒌 and 𝒍 (% error) modified 𝒌 and 𝒍 (% error) the difference (% error) 0.25 7.65 % 4.97 % 2.68 % 0.5 13.41 % 8.57 % 4.84 % 0.75 15.14 % 7.21 % 7.93 % table 2. performance improvement mrac with modified feedback gains 𝒌 and 𝒍 in the experiment amplitude performance improvement with modified 𝒌 and 𝒍 (in percentage) 0.25 35.1 % 0.5 36 % 0.75 52.4 % m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 19 figures 5 and 6 show the simulation responses are better than the experimental responses. this happens because the bbs model in simulation is defined as a linear system and is unaffected by any disturbances. in the experiment, the non-linear dynamics cannot be neglected, but it can be seen that the mrac with modified feedback gains gives a better response or synchronization. figure 5. comparison of simulations and experiments of bbs without initial definition and saturation values at the amplitude of (a) 0.25; (b) 0.5; and (c) 0.75 m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 20 table 3 shows the ball position error both in simulation and experiment. it is shown that the designed mrac with modified feedback gain gives a different response error between the simulation and experiment of less than 10 %. we have different responses error between the simulation and figure 6. comparison of simulations and experiments of bbs with initial definition and saturation values at the amplitude of (a) 0.25; (b) 0.5; and (c) 0.75 m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 21 experiment in the case of sinusoidal with an amplitude of 0.25, 0.5, and 0.75 equal to 4.37 %, 6.37 %, and 6.56 %, respectively. future work may include implementing adaptive control that takes into account the input saturation [15], where we know that the bbs system has limited servo actuation. figure 7. comparison of the ball position when using the mrac with modified feedback gains and standard mrac in the experiment at the amplitude of (a) 0.25; (b) 0.5; and (c) 0.75 m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 22 iv. conclusion in this research, we have shown that the modified feedback gains are able to make the system performance better, which is shown by a smaller error value. this work shows the experiment result of the mrac and we proposed the modified feedback gains 𝑘 and 𝑙 . the state-feedback mrac with modified feedback gains 𝑘 and 𝑙 experiment resulted in a smaller ball position error with lower error percentage value of 2.68 % for the sinusoidal amplitude of 0.25, 4.84 % for the sinusoidal amplitude of 0.5, and 7.93 % for the sinusoidal amplitude of 0.75. the performance improvement with modified 𝑘 and 𝑙 (in percentage) is 35.1 % for the sinusoidal amplitude of 0.25, 36 % for the sinusoidal amplitude of 0.5, and 52.4 % for the sinusoidal amplitude of 0.75. comparison of the simulation ball position errors is better in the simulation. this happens due to the simplified bbs model and the absence of any disturbances. the modification of the feedback gains gives better ball position convergence to the reference model, but a testing case is required to get the information on the initial values and saturation values of the feedback gains. acknowledgment the authors express their gratitude to the ministry of research and technology of the republic of indonesia (ristekdikti) for providing the post doctoral research at bandung institute of technology (itb). declaration author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] p. kotsampopoulos et al., "a benchmark system for hardwarein-the-loop testing of distributed energy resources," ieee power and energy technology systems journal, vol. 5, no. 3, pp. 94-103, sept. 2018. [2] k. s. amitkumar, r. s. kaarthik, and p. pillay, "a versatile power-hardware-in-the-loop-based emulator for rapid testing of transportation electric drives," ieee transactions on transportation electrification, vol. 4, no. 4, pp. 901-911, dec. 2018. [3] j. e. gaudio, a. m. annaswamy, e. lavretsky, and m. bolender, "parameter estimation in adaptive control of time-varying systems under a range of excitation conditions," ieee transactions on automatic control, 2021. [4] g. lymperopoulos and p. ioannou, "model reference adaptive control for networked distributed systems with strong interconnections and communication delays," j syst sci complex 31, pp. 38–68, 2018. [5] t. yucelen and w. m. haddad, "low-frequency learning and fast adaptation in model reference adaptive control," ieee transactions on automatic control, vol. 58, no. 4, pp. 10801085, april 2013. [6] c. yuquan, w. yiheng, l. shu, w. yong, "indirect model reference adaptive control for a class of fractional order systems," communications in nonlinear science and numerical simulation, volume 39, pp. 458-471, 2016, issn 1007-5704. [7] i. barkana, "simple adaptive control–a stable direct model reference adaptive control methodology–brief survey", international journal of adaptive control and signal processing, volume 28, issue 7-8, 2014, pp. 567-604. [8] joseph e. gaudio, anuradha m. annaswamy, eugene lavretsky and michael a. bolender. "fast parameter convergence in adaptive flight control," aiaa 2020-0594. aiaa scitech 2020 forum. january 2020. [9] m.f. rahmat, h. wahid, and n.a. wahab, "application of intelligent controller in a ball and beam control system," international journal on smart sensing and intelligent systems, 3(1), pp. 45-60, 2017. [10] y. h. chang, w. s. chan, and c. w. chang, “t-s fuzzy modelbased adaptive dynamic surface control for ball and beam system,” ieee trans. ind. electron., vol. 60, no. 6, pp. 2251– 2263, 2013. [11] p. jain and m. j. nigam, “real time control of ball and beam system with model reference adaptive control strategy using mit rule,” 2013 ieee int. conf. comput. intell. comput. res. (ieee iccic 2013), no. 4, pp. 4–7, 2013. [12] i. m. mehedi, u. m. al-saggaf, r. mansouri, and m. bettayeb, "two degrees of freedom fractional controller design: application to the ball and beam system," measurement, volume 135, pp. 13-22, 2019, issn 0263-2241. [13] s. s. tohidi, y. yildiz, and i. kolmanovsky, "adaptive control allocation for constrained systems," automatica, volume 121, 109161, 2020, issn 0005-1098. [14] p. ioannou and b. fidan, "adaptive control tutorial," advance in design and control, 2006. table 3. comparison of the ball position error values in simulations and experiments bbs amplitude simulation (% error) experiment (% error) difference between simulation and experiment (% error) 0.25 0.004 % 7.65 % 7.646 % 0.25-modified 𝒌 and 𝒍 0.6 % 4.97 % 4.37 % 0.5 0.0036 % 13.41 % 13.4064 % 0.5-modified 𝒌 and 𝒍 2.2 % 8.57 % 6.37 % 0.75 0.004 % 15.14 % 15.136 % 0.75-modified 𝒌 and 𝒍 0.65 % 7.21 % 6.56 % https://mev.lipi.go.id/ https://doi.org/10.1109/jpets.2018.2861559 https://doi.org/10.1109/jpets.2018.2861559 https://doi.org/10.1109/jpets.2018.2861559 https://doi.org/10.1109/jpets.2018.2861559 https://doi.org/10.1109/tte.2018.2857216 https://doi.org/10.1109/tte.2018.2857216 https://doi.org/10.1109/tte.2018.2857216 https://doi.org/10.1109/tte.2018.2857216 https://doi.org/10.1109/tte.2018.2857216 https://doi.org/10.1109/tac.2021.3126243 https://doi.org/10.1109/tac.2021.3126243 https://doi.org/10.1109/tac.2021.3126243 https://doi.org/10.1109/tac.2021.3126243 https://doi.org/10.1007/s11424-018-7172-2 https://doi.org/10.1007/s11424-018-7172-2 https://doi.org/10.1007/s11424-018-7172-2 https://doi.org/10.1007/s11424-018-7172-2 https://doi.org/10.1109/tac.2012.2218667 https://doi.org/10.1109/tac.2012.2218667 https://doi.org/10.1109/tac.2012.2218667 https://doi.org/10.1109/tac.2012.2218667 https://doi.org/10.1016/j.cnsns.2016.03.016 https://doi.org/10.1016/j.cnsns.2016.03.016 https://doi.org/10.1016/j.cnsns.2016.03.016 https://doi.org/10.1016/j.cnsns.2016.03.016 https://doi.org/10.1016/j.cnsns.2016.03.016 https://doi.org/10.1002/acs.2411 https://doi.org/10.1002/acs.2411 https://doi.org/10.1002/acs.2411 https://doi.org/10.1002/acs.2411 https://doi.org/10.2514/6.2020-0594 https://doi.org/10.2514/6.2020-0594 https://doi.org/10.2514/6.2020-0594 https://doi.org/10.2514/6.2020-0594 https://doi.org/10.21307/ijssis-2017-378 https://doi.org/10.21307/ijssis-2017-378 https://doi.org/10.21307/ijssis-2017-378 https://doi.org/10.21307/ijssis-2017-378 https://doi.org/10.1109/tie.2012.2192891 https://doi.org/10.1109/tie.2012.2192891 https://doi.org/10.1109/tie.2012.2192891 https://doi.org/10.1109/tie.2012.2192891 https://doi.org/10.1109/iccic.2013.6724180 https://doi.org/10.1109/iccic.2013.6724180 https://doi.org/10.1109/iccic.2013.6724180 https://doi.org/10.1109/iccic.2013.6724180 https://doi.org/10.1016/j.measurement.2018.11.021 https://doi.org/10.1016/j.measurement.2018.11.021 https://doi.org/10.1016/j.measurement.2018.11.021 https://doi.org/10.1016/j.measurement.2018.11.021 https://doi.org/10.1016/j.automatica.2020.109161 https://doi.org/10.1016/j.automatica.2020.109161 https://doi.org/10.1016/j.automatica.2020.109161 https://doi.org/10.1137/1.9780898718652 https://doi.org/10.1137/1.9780898718652 m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 15-23 23 [15] m. r. rosa, “leader-follower synchronization of uncertain euler-lagrange dynamics with input constraints,” aerospace, vol. 7, no. 9, 2020. https://doi.org/10.3390/aerospace7090127 https://doi.org/10.3390/aerospace7090127 https://doi.org/10.3390/aerospace7090127 i. introduction ii. materials and methods a. ball and beam system b. model reference adaptive control (mrac) c. system setup d. system flowchart e. state feedback direct mrac setup iii. results and discussions a. state feedback direct mrac on ball and beam system experiment b. the influence of the initial definition and saturation value on the bbs system iv. conclusion acknowledgment declaration author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia aji prasetya wibawa, ph.d. department of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. yusie rizal, phd cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. laksono kurnianggoro department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia suprapto, ph.d departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia alexander christantho budiman ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. phh. mustafa no. 23, bandung, jawa barat, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia aditya nugraha, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani,m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix budi azhari, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor , city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.1-10 2088-6985 / 2087-3379 ©2020 research center for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). accreditation number: (ristekdikti) 1/e/kpt/2015. swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm endra joelianto a, c, *, daniel christian b, agus samsi c a instrumentation and control research group institut teknologi bandung jl. ganesha no. 10, bandung, 40132, indonesia b externship researcher of engineering physics study program institut teknologi bandung jl. ganesha no. 10, bandung, 40132, indonesia c engineering physics study program institut teknologi bandung jl. ganesha no. 10, bandung, 40132, indonesia received 30 april 2020; accepted 21 june 2020; published online 30 july 2020 abstract unmanned aerial vehicle (uav) quadrotors have developed rapidly and continue to advance together with the development of new supporting technologies. however, the use of one quadrotor has many obstacles and compromises the ability of a uav to complete complex missions that require the cooperation of more than one quadrotor. in nature, one interesting phenomenon is the behaviour of several organisms to always move in flocks (swarm), which allows them to find food more quickly and sustain life compared with when they move independently. in this paper, the swarm behaviour is applied to drive a system consisting of six uav quadrotors as agents for flocking while tracking a swarm trajectory. the swarm control system is expected to minimize the objective function of the energy used and tracking errors. the considered swarm control system consists of two levels. the first higher level is a proportional – derivative type controller that produces the swarm trajectory to be followed by uav quadrotor agents in swarming. in the second lower level, a linear quadratic regulator (lqr) is used by each uav quadrotor agent to follow a tracking path well with the minimal objective function. a genetic algorithm is applied to find the optimal lqr weighting matrices as it is able to solve complex optimization problems. simulation results indicate that the quadrotors' tracking performance improved by 36.00 %, whereas their swarming performance improved by 17.17 %. ©2020 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: unmanned aerial vehicle (uav); quadrotor model; swarm model; proportional – derivative (pd) controller; linear quadratic regulator (lqr); optimization problems; genetic algorithm. i. introduction unmanned aerial vehicles (uavs) are a type of aircraft that continues to develop because of its ability to fly without a human pilot. with the development of technology, especially for unmanned aircraft driven by propellers, the interest of researchers to acquire air vehicles with four rotors (quadrotor) is increasing [1][2][3]. the potential use of uav quadrotors is progressing rapidly and extensively, ranging from simple flying to performing difficult tasks such as carrying equipment to places that are not easily accessible or are dangerous. for example, a quadrotor can be used to bring first-aid equipment to victims who are in locations that are difficult to reach, to find and notify about the location of earthquake victims in a building, and to take aerial photographs of areas that are difficult to visit. a uav quadrotor has several advantages over conventional propeller planes, which are only driven by one or two rotors. the propeller on the opposite side of a quadrotor rotates in the opposite direction so that the gyroscopic effect, torque, and moment on the axis of the plane tend to be more balanced [1]. as a result, quadrotor aircraft can maneuver better and can approach obstacles without having to fear to crash [2]. moreover, the quadrotor's ability to fly vertically and float makes this type of aircraft very suitable for flying in areas that have many obstacles. research on quadrotors and how to fly them has received considerable attention in many years. bresciani [3] in his thesis has modelled a quadrotor * corresponding author. tel: +62-22-2504424; fax: +62-22 2506281 e-mail address: ejoel@tf.itb.ac.id https://dx.doi.org/10.14203/j.mev.2020.v11.1-10 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.1-10 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 2 by explaining the influence of aerodynamic forces acting on it and modelling its components. sudiyanto et al. [1] have developed quadrotor modelling by using the first-principle approach. one of the problems in uav quadrotors is the limited payload available, as this depends on lift force of the rotors. in many practical applications, the payload problem can be solved by using many quadrotors [4]. advances in uav technologies and improvement of sensor capabilities have led to group operation of quadrotors, which is important for applications that require large coverage areas such as search and rescue missions, inspection and detection, and surveillance reconnaissance [5]. swarming is a group behaviour that is found in nature. this group behaviour can be found in organisms that live in groups such as bacteria, birds, fish, and ants. swarm behaviour can arise through various mechanisms that are usually out of the instinct of the organism [6]. several studies on models and controls for moving together have also been carried out, on mobile robots [7][8][9], autonomous helicopter [10][11], and quadrotor [12][13][14]. in [15], a modelled multi-agent swarm movement of a system to be able to follow the desired path has been investigated. coordination of movements between two or more quadrotors is needed to optimize the work to be performed by the quadrotors. therefore, the swarm coordination of quadrotors is a very interesting topic to study. research on quadrotor swarm has been carried out in previous studies [16][17][18]. in [17], quadrotor swarming is considered using the leader–follower formation approach. in [18], the particle optimization approach is used to make the optimal formation control for a group of quadrotors. some studies did not consider linear quadratic regulator (lqr) controllers, although they are well-known controllers that have been used in various applications, such as in controller systems, up until now [19][20][21]. the use of an lqr controller on a quadrotor is only for maneuver control, not yet for swarm motion [22][23]. the selection of lqr weighting matrices in the cost function is a major obstacle that makes it difficult to obtain the minimum cost function performance or desired control response. in the diagonal weighting matrix, the number of selected weight values is proportional to the order of the system plus the number of system control signals. weight selection is often done by trial and error or using the desired response based on the analysis method [24][25]. recently, many studies have proposed using the genetic algorithm (ga) method to obtain the lqr weighting matrices, which results in desired control performances more quickly and easily [26][27][28]. this paper considers a swarm control system of many quadrotors with two levels of the control loop and also defines simulation showing the coordination of six uav quadrotor models to move and to form flocks. the design of the swarm control system is used in three-dimensional space simulations. given the length limit of the article, the swarm center reference model is assumed to have been optimally provided by the higher-level control. this paper then focuses on designing the tracking control of the optimal swarm center reference model with lqr to minimize tracking errors. the problem of selecting the optimal weighting matrices of lqr is difficult to handle, but in this paper, the problem is solved by implementing a ga in order to produce the optimal performance of the uav quadrotor swarm control system, which minimizes swarm tracking control errors in terms of the root-mean-square error (rmse). ii. materials and methods a. quadrotor mathematical model the working principle of a quadrotor is the balance of lift and torque produced by the rotation of four rotors. the lifting force is obtained from the acceleration of air around the blades that occurs because of the rotation of the rotors. accelerated air displacement produces forces in the opposite direction from the air displacement. if the force exceeds the weight of the quadrotor, then the quadrotor can move vertically. the forward and reverse movements, as well as the left and right movements, can be obtained with the combination of the four propellers. for example, the forward movement results from the rotation of the two front propellers, which is faster than that of the propellers on the backside. this combination produces the resultant force and torque that make the quadrotor move forward. figure 1 shows the main components of a uav quadrotor and the lifting force generated by the rotors. in addition to lifting, a quadrotor also works by balancing the torque produced by the four propellers. setting the rotation speed of the rotating blades opposite can adjust the quadrotor rotation. in general, maneuvers that can be carried out by a quadrotor are shown in [29]. the lift force and torque of the blades are greatly influenced by the type of blades used. calculation of lift and torque can be explained through the momentum theory and propeller element theory. the momentum theory can be used to determine the relationship between lift, speed, and power in the propeller [1]. the principle of energy conservation is used to formulate the lift force in a floating state by including the efficiency of the rotor. based on newton's second law for translational motion with the fixed vehicle mass, the transformation matrix of the earth axis, the body axis, and angular movements, the equilibrium moment equations are obtained. using the translational motion with fixed vehicle mass in the form of cartesian coordinates and kinematic triad relations, the following nonlinear model of a quadrotor is obtained using equations (1) to (9): �̇�𝐵 = 1 𝑚 ∙ ∑𝐹𝑥𝐵 − 𝑔 ∙ sin 𝜃 + 𝑟 ∙ 𝑣𝐵 − 𝑞 ∙ 𝑤𝐵 (1) �̇�𝐵 = 1 𝑚 ∙ ∑𝐹𝑦𝐵 + 𝑔 ∙ sin 𝜙 ∙ cos 𝜃 − 𝑟 ∙ 𝑢𝐵 + 𝑝 ∙ 𝑤𝐵 (2) �̇�𝐵 = 1 𝑚 ∙ ∑𝐹𝑧𝐵 + 𝑔 ∙ cos 𝜙 ∙ cos 𝜃 + 𝑞 ∙ 𝑢𝐵 + 𝑝 ∙ 𝑣𝐵 (3) e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 3 �̇� = 1 𝐽𝑥𝑥 ∙ ∑𝑀𝑥 − (𝐽𝑧𝑧−𝐽𝑦𝑦) 𝐽𝑥𝑥 ∙ 𝑞 ∙ 𝑟 (4) �̇� = 1 𝐽𝑥𝑥 ∙ ∑𝑀𝑥 − (𝐽𝑧𝑧−𝐽𝑦𝑦) 𝐽𝑥𝑥 ∙ 𝑞 ∙ 𝑟 (5) �̇� = 1 𝐽𝑥𝑥 ∙ ∑𝑀𝑥 − (𝐽𝑧𝑧−𝐽𝑦𝑦) 𝐽𝑥𝑥 ∙ 𝑞 ∙ 𝑟 (6) �̇� = 1 𝐽𝑥𝑥 ∙ ∑𝑀𝑥 − (𝐽𝑧𝑧−𝐽𝑦𝑦) 𝐽𝑥𝑥 ∙ 𝑞 ∙ 𝑟 (7) �̇� = 1 𝐽𝑥𝑥 ∙ ∑𝑀𝑥 − (𝐽𝑧𝑧−𝐽𝑦𝑦) 𝐽𝑥𝑥 ∙ 𝑞 ∙ 𝑟 (8) �̇� = (𝑞 ∙ sin 𝜙 + 𝑟 ∙ cos 𝜙) ∙ sec 𝜃 (9) equations (1) to (9) show the quadrotor motion state variables consisting of three body velocity variables ( 𝑢𝐵 , 𝑣𝐵 , 𝑤𝐵 ), three angular velocity variables (p, q, r), and three angular variables ( 𝜙, 𝜃, 𝜓) . the detail derivation and the notation description can be found in [1]. the quadrotor mathematical model can then be written in the linear time-invariant state space equation after being linearized in the specified flying conditions as equations (10) and (11): �̇�(𝑡) = 𝐴𝑥(𝑡) + 𝐵𝑢(𝑡); 𝑥(𝑡0) = 𝑥0 (10) 𝑦(𝑡) = 𝐶𝑥(𝑡) + 𝐷𝑢(𝑡) (11) where 𝑥 ≜ {𝑑𝑢 𝑑𝑣 𝑑𝑤 𝑑𝑝 𝑑𝑞 𝑑𝑟 𝑑𝜙 𝑑𝜃 𝑑𝜓} , 𝑥 ∈ 𝑅𝑛 , denote state space variables, and 𝑢 ≜ {𝑑ω𝑅1 𝑑ω𝑅2 𝑑ω𝑅3 𝑑ω𝑅4 } , 𝑢 ∈ 𝑅𝑚 , describe input variables; 𝑦 denotes the output, 𝑦 ∈ 𝑅𝑙 ; and the matrices are 𝐴 ∈ 𝑅𝑛𝑥𝑛 , 𝐵 ∈ 𝑅𝑛𝑥𝑚 , 𝐶 ∈ 𝑅𝑛𝑥𝑙 , and 𝐷 ∈ 𝑅𝑙𝑥𝑙. the initial state condition at the time 𝑡0 is denoted by 𝑥0 . the components of the matrix {𝐴,𝐵,𝐶 ,𝐷} of the linear time-invariant quadrotor model in equations (10) and (11) used in this paper are obtained when flying it at a speed of 5 m/s as follows [1]. b. swarm model each swarm agent, in this case, a quadrotor, is assumed to move simultaneously and know the relative position of its members. the equation of motion of individual 𝑖 by following [30] is given by the following equation (13): �̇�𝑖 = −∇𝑥𝑖𝜌(𝑥𝑖) + ∑ 𝑓(𝑥𝑖 − 𝑥𝑗 𝑁 𝑗=1,𝑗≠𝑖 ), 𝑖 = 1, ⋯ , 𝑁 (13) where 𝑥𝑖𝜖 𝑅 𝑛 denotes the position of individual 𝑖 , 𝜌(·): 𝑅 → 𝑅 is an odd function, and 𝑁 denotes the number of individual swarm members. in the second term, 𝑓(∙) is a function that describes the mutual attraction and repulsion that occur between agents as the following equation (14) [31][32]: 𝑓(𝑦) = −𝑦�𝑎 − 𝑏 exp(− ||𝑦||2 𝑐 )� (14) where 𝑎 , 𝑏 , and 𝑐 are positive constants and ||𝑦|| represents the distance between agents. equation (14) shows that attraction dominates on long distances, whereas repulsion dominates on close distances. the function determines the direction and movement of each agent and prevents collisions between agents. in practice, the value 𝜌(·) represents the attractant, repellent, or neutral profile that determines where the swarm agents will move together, for example, if there are hot spots in an area or the source of leakage of toxic chemicals [30]. the negative 𝜌(·) value represents the attractant profile where the swarm agents will gather, whereas the positive 𝜌(·) value indicates the repellent profile where the swarm agents will move away. the neutral condition is denoted by 𝜌(·) = 0. distance is 𝐴 = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 −0.1008 −0.1285 −9.8034 0 0 0 0 0 0 0 0 0 0 −1.9314 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 −0.1285 9.8034 0 −4.9983 0 0 0 0 0 0 0 0 −1.9314 0 0 0.0867 0 0 0 0 −0.0531 4.9983 0.2520 0 0 0 −1.1869 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ 𝐵 = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 −0.0017 0.0022 0 0 0 0 0 0 0 0 0 0 −0.0004 0.0008 −0.0014 0.0030 0 0 0 0 0.0086 0.0111 −0.0111 −0.0111 −0.0013 −0.0014 −0.0014 −0.0014 0 0 0 0 ⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ 𝐶 = � 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 � 𝐷 = 0 (12) e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 4 affected by repulsion, and its magnitude is affected by parameters 𝑎, 𝑏, and 𝑐. there is a position where the magnitudes of attraction and repulsion are balanced. the magnitude of the dominant attractant for ||𝑦|| > 𝛿, and that for the dominant repellent for ||𝑦|| < 𝛿. from (14), it can be seen that a sign change occurred at that time using equation (15): 𝑦 = 𝛿 = � 𝑦 = 0 ‖𝑦‖ = �𝑐 ln 𝑏 𝑎 (15) it should also be noted that the change in sign will only occur if the value of 𝑏 > 𝑎 ; thus, the condition will be obtained when the attraction function changes to the repulsion function. if this condition is not met, then there will be no change in the value of the function, resulting in a collision between swarm agents. by using the attraction/repulsion model as in equation (14), for 𝑡 → ∞, the swarm model will stop moving [30]. this shows that at time instant 𝑡,̅ the agents in the swarm will be in a position where the attraction and repulsion functions will be balanced. the cohesiveness of swarm agents can be influenced by the selected model. movement between agents can be done by referring these agents to the swarm center as it will always be in the same position [31]. another alternative is to refer to the position of an agent to other agents. moreover, based on the model used, swarm cohesiveness can also be influenced by the nature of the attraction and repulsion functions. attractions and repulsions in the swarm model can be local, when they occur only because they reached a certain threshold, or global when they are felt by the agent in whatever position the agent is located. based on the theorem developed by gazy and passino [31], it can be said that if a swarm system has only an attraction function, then the swarm agents will converge to a point that is the center of the swarm. by contrast, if the system has only a repulsion function, the swarm agents will move away from the central point to an infinite position. on this basis, it can be concluded that the best model that can be used is one that has the attraction function dominating at large distances to prevent swarm agents from dispersing and the repulsion function dominating at close distances to prevent these agents from colliding with each other [30]. c. quadrotor tracking quadrotor tracking is expected to produce very small quadrotor position errors against the desired target. the technique commonly used is to add an integrator to an error or to use a derivative of an error [25]. error state variables are described as equation (16): 𝑒(𝑡) ≜ 𝑥𝑟𝑒𝑓(𝑡) − 𝑥(𝑡) (16) if derived from time, then the following equation (17) is obtained: �̇�(𝑡) = �̇�𝑟𝑒𝑓(𝑡) − �̇�(𝑡) (17) if the reference does not change (tracking target at a fixed point), then the derivative of 𝑥𝑟𝑒𝑓 is 0, so �̇�(𝑡) = −�̇�(𝑡). from (17), the path tracking equation can use the following general equation (18): �̇�(𝑡) = −𝜂�̇�(𝑡) (18) where 𝜂 represents a constant that determines the weight of the tracking in the cost function. in the form of a matrix, the above equation can be written as equation (19): �̇�(𝑡) = � �̇�𝑥(𝑡) �̇�𝑦(𝑡) �̇�𝑧(𝑡) � = � −𝜂�̇�𝑥(𝑡) −𝜂�̇�𝑦(𝑡) −𝜂�̇�𝑧(𝑡) � (19) substituting �̇�𝑥 = 𝑢 , �̇�𝑦 = 𝑣 , and �̇�𝑧 = 𝑤 yields equation (20): �̇�(𝑡) = � �̇�𝑥(𝑡) �̇�𝑦(𝑡) �̇�𝑧(𝑡) � = � −𝜂𝑢(𝑡) −𝜂𝑣(𝑡) −𝜂𝑤(𝑡) � (20) based on the theorem developed [30], for an ideal system, the swarm center point will not move when the agents are flocking. therefore, when given a target, the movement of the swarm center should be a straight line from the initial swarm center position toward the target [31]. d. a two-level swarm control system the swarm control system consists of two levels. the lower-level controller uses a discrete lqr to control the movement of an individual quadrotor so that it can follow the desired tracking path. on the other hand, the higher-level controller is a proportional – derivative (pd) type controller that controls the movement between swarm members by producing paths that must be followed by each quadrotor. the swarm control system block diagram followed [11] is shown in figure 2. 1) lower-level control the lower-level controller uses a discrete lqr. this controller is used to control the movement of each quadrotor against the trajectory produced by the high-level controller. a full state feedback gain 𝐾𝐿𝑄𝑅 of the lqr is obtained by varying the weighting matrices 𝑄 = 𝑄𝑇 ≥ 0 and 𝑅 = 𝑅𝑇 > 0 on a cost function defined as equation (21): 𝐽∞ = ∑ [𝑥𝑇(𝑘)∞𝑘=1 𝑄𝑥(𝑘) + 𝑢𝑇(𝑘)𝑅𝑢(𝑘)] (21) with discretized dynamic equations of each quadrotor (10) given by equation (22): 𝑥(𝑘 + 1) = 𝐴𝑥(𝑘) + 𝐵𝑢(𝑘) (22) optimal quadratic control signal 𝑢(𝑘), by using the tracking definition and discretized error (16) above, is defined as equation (23): 𝑢(𝑘) = −𝐾𝐿𝑄𝑅𝑒(𝑘) (23) with a full state feedback gain matrix 𝐾𝐿𝑄𝑅 that fulfils the equation (24): 𝐾𝐿𝑄𝑅 = (𝑅 + 𝐵𝑇𝑆𝐵)−1𝐵𝑇𝑆𝐴 (24) e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 5 the 𝑆 matrix is the steady-state solution of the algebraic riccati equation in equation (25): 𝑆 = 𝑄 + 𝐴𝑇𝑆𝐴 − 𝐴𝑇𝑆𝐵(𝑅 + 𝐵𝑇𝑆𝐵)−1𝐵𝑇𝑆𝐴 (25) the riccati equation is solvable if the pair {𝐴, 𝐵} is stabilizable and there is no unobservable mode on the unit circle of the pair {𝑄, 𝐴}. two adjustable variables are sought to optimize the cost function (21) of the lower-level controller, namely, the 𝑄 and 𝑅 matrices. the 𝑄 matrix has row and column sizes of a number of state variables in the system, whereas the matrix r has a number of rows of input variables. the movement of a controlled quadrotor agent will be determined based on a closed-loop system in the state space function in equation (26): 𝑥(𝑘 + 1) = �𝐴 − 𝐵𝐾𝐿𝑄𝑅�𝑥(𝑘) + 𝐾𝐿𝑄𝑅𝑥𝑟𝑒𝑓(𝑘) 𝑦(𝑘) = 𝐶𝑥(𝑘) (26) the closed-loop system (26) is asymptotically stable utilizing the solvability of the riccati equation (25) [25]. 2) higher-level control the higher-level controller in the swarm model used in this paper implements a pd controller. the attraction and repulsion functions used follow equation (14). in addition to the above functions, the swarm agent movement is also influenced by a repulsion function that occurs if the agent is too close. this function is represented in equation (27): 𝑢′ = 𝑘𝑟 exp � −1 2 �𝑥𝑖−𝑥𝑗� 2 𝑟𝑠 2 � (27) where 𝑘𝑟 > 0 is the magnitude of the repulsion and 𝑟𝑠 > 0 is the size of the area around the agent. the difference between agents is too far; that is, when �𝑥𝑖 − 𝑥𝑗� is very large relative to 𝑟𝑠 , then the function will be zero. let us respectively define the swarm center and the average velocity, which are generally time-varying [33], as equation (28): �̅� = 1 𝑁 ∑ 𝑥𝑖𝑁𝑖−1 and �̅� = 1 𝑁 ∑ 𝑣𝑖𝑁𝑖−1 (28) the dynamics of the error system for position and velocity of each agent 𝑖 are defined as equation (29): 𝑒𝑖,𝑝 = 𝑥𝑖 − �̅� and 𝑒𝑖,𝑣 = 𝑣𝑖 − �̅� (29) in the end, the movement of the agent in the swarm model used in this paper is determined by the equation (30) in [33]. 𝑢𝑖 = −𝑀𝑖𝑘𝑎𝑒𝑖,𝑝 − 𝑀𝑖𝑘𝑏𝑒𝑖,𝑣 − 𝑀𝑖𝑘𝑣𝑣𝑖 +𝑀𝑖𝑘𝑟 ∑ exp � 1 2 �𝑒𝑖,𝑝−𝑒𝑗.𝑝� 𝑟𝑠 2 ��𝑒𝑖,𝑝 − 𝑒𝑗,𝑝� − 𝑀𝑖𝑘𝑓�∇𝐽𝑝(𝑥𝑖) − 𝑑𝑓 𝑖� (30) here, it is assumed that each agent has mass 𝑀𝑖 and velocity 𝑣𝑖 with a bounded sensing noise signal 𝑑𝑓 𝑖 . the scalar value 𝑘𝑎 > 0 denotes a reinforcement of attraction indicating how aggressive the agent is to aggregate. the scalar value 𝑘𝑟 > 0 is a reinforcement of repulsion that indicates how much agent 𝑖 will move away from agent 𝑗. in this paper, the developed swarm model has the characteristic of having no leader among swarm members. swarm member dynamic equations are modelled as in equation (14). the state of agent 𝑖 was defined with 𝑥𝑖 (𝑖 = 1, … , 𝑁), and it is assumed that the agent moves in the 𝑛 -dimension in euclidean space, with the equation of motion of each agent determined by the combination of the following equations: �̇�𝑖 = 𝑣𝑖 𝑚�̇�𝑖 = 𝑢𝑖 ; 𝑥𝑖, 𝑣𝑖, 𝑢𝑖 ∈ 𝑅𝑛, 𝑖 = 1, … , 𝑁 (31) where, respectively, 𝑥𝑖, 𝑣𝑖, 𝑢𝑖, and 𝑚𝑖 are the position, speed, control input, and mass of the agent. the main goal of the swarm model control design is to control the dynamic movement of all swarm members to the desired position. the dynamic movement of the agent is influenced by the following: (i) the distance and velocity between the agents, and (ii) the attraction and repulsion on the designed profile. in this paper, the control protocol is a modification from [33] for the agent modelled as equation (32): 𝑢𝑖 = −𝑀𝑖𝑘𝑎𝑒𝑖,𝑝 − 𝑀𝑖𝑘𝑏𝑒𝑖,𝑣 − 𝑀𝑖𝑘𝑣𝑣𝑖 +𝑀𝑖 ∑ (𝑎 − 𝑏)exp � ||𝑒𝑖,𝑝−𝑒𝑗,𝑝|| 𝑐 �𝑁𝑖=1.𝑖≠𝑗 �𝑒𝑖,𝑝 − 𝑒𝑖,𝑝� − 𝑀𝑖𝑘𝑓 �∇𝐽𝑝(𝑥𝑖)� (32) it is assumed that the agent is equipped with sensors and programs having the mass of 𝑀𝑖 and the speed of 𝑣𝑖 . the proportional gain 𝑘𝑎 > 0 is a reinforcement that affects the aggressiveness of the agent to aggregate. the gain 𝑘𝑟 > 0 functions as a parameter that affects the repulsion that occurs between agents. both 𝑘𝑎 and 𝑘𝑏 are proportional gains, whereas 𝑘𝑣 and 𝑘𝑓 are attenuation of speed and derivative strengthening to follow the desired agent movement profile. the model in (32) is modified from (30), by adding the attraction force between the agent and the value 𝑀𝑖 = 1 (to simplify the control system). the swarm control system diagram block is designed as in figure 2. iii. results and discussions a. determination of trial and error parameters the mathematical equation model implemented in the simulation uses the parameters of reference [1] discretized with 0.01 s sampling time. searching for the optimal values of 𝑄 and 𝑅 using the trial and error method, the initial parameters are simulated using predetermined 𝑄 and 𝑅 matrices as equations (33) and (34): iq iq iq iq ×= ×= ×= ×= 10000 1000 100 10 4 3 2 1 (33) e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 6 ir ir ir ir ×= ×= ×= ×= 0001.0 001.0 01.0 1.0 4 3 2 1 (34) where i denote the identity matrix with an appropriate size of 𝑄 and 𝑅. the combination of the parameters 𝑄 and 𝑅 from equation (33) and (34) is then simulated for tracking a quadrotor on the trajectory function defined by 𝑙(𝑡) using equation (35): 𝑙𝑥(𝑡) = ⎩ ⎪ ⎨ ⎪ ⎧ 𝑥0 + 𝑡 20 , for 0 < 𝑡 ≤ 1000 𝑥0 + 50, for 1000 < 𝑡 ≤ 2000 𝑥0 + �50 − 𝑡 − 2000 20 � , for 2000 < 𝑡 ≤ 3000 𝑥0, 𝑓𝑜𝑟 3000 < 𝑡 ≤ 3999 𝑙𝑦(𝑡) = ⎩ ⎪ ⎨ ⎪ ⎧ 𝑦0, for 0 < 𝑡 ≤ 1000 𝑦0 + 𝑡 − 1000 20 , for 1000 < 𝑡 ≤ 2000 𝑦0 + 50, for 2000 < 𝑡 ≤ 3000 𝑦0 + �50 − 𝑡 − 3000 20 � , for 3000 < 𝑡 ≤ 3999 𝑙𝑧(𝑡) = ⎩ ⎪ ⎨ ⎪ ⎧ 𝑧0 + 𝑡 20 , for 0 < 𝑡 ≤ 1000 𝑧0 + 50, for 1000 < 𝑡 ≤ 2000 𝑧0 + (50 − 𝑡−2000 20 ), for 2000 < 𝑡 ≤ 3000 𝑦0, for 3000 < 𝑡 ≤ 3999 (35) the performance of the tracking error is measured using the rmse method. the best weight matrix results are obtained for 𝑄 = 1000𝐼 and 𝑅 = 0.001𝐼, which have an rmse value of 7.122 m. simulation results are shown in figure 3. b. parameter optimization using genetic algorithm ga is one area of research that has received considerable attention until now [34][35][36]. gas can help produce a solution of complex functions on the basis of the selection process that occurs in nature. they work on the basis of the initial population that can be linked to certain variables. in general, this initial population contains randomly constructed binary combinations 1 and 0. this binary combination corresponds to the value of the variable to be found. in this paper, by following the ga, the mating probability of each chromosome is determined using the following equation (36): 𝑝𝑟𝑜𝑏𝑎𝑏𝑖𝑙𝑖𝑡𝑦 = 𝑓𝑖𝑡𝑛𝑒𝑠𝑠 𝑡𝑜𝑡𝑎𝑙 𝑓𝑖𝑡𝑛𝑒𝑠𝑠 × 100% (36) the parameters used in the ga are as follows: the number of chromosomes, which is 20; the number of genes per chromosome, 1,000; and the number of generations produced, 30. the chromosomes containing binary numbers are encoded into realvalued individuals in the specified interval of [100; 1,000]. the process of reproduction of selected chromosomes has a crossover probability of 0.6. chromosomes in a population have a mutation probability of 0.5 %. next, the ga is applied to find the 𝑄1 to 𝑄12 parameters in the matrix 𝑄 defined as equation (37): 𝑄 = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ 𝑄1 0 0 0 0 0 0 0 0 0 0 0 0 𝑄2 0 0 0 0 0 0 0 0 0 0 0 0 𝑄3 0 0 0 0 0 0 0 0 0 0 0 0 𝑄4 0 0 0 0 0 0 0 0 0 0 0 0 𝑄5 0 0 0 0 0 0 0 0 0 0 0 0 𝑄6 0 0 0 0 0 0 0 0 0 0 0 0 𝑄7 0 0 0 0 0 0 0 0 0 0 0 0 𝑄8 0 0 0 0 0 0 0 0 0 0 0 0 𝑄9 0 0 0 0 0 0 0 0 0 0 0 0 𝑄10 0 0 0 0 0 0 0 0 0 0 0 0 𝑄11 0 0 0 0 0 0 0 0 0 0 0 0 𝑄12⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ (37) and the value of 𝑅𝑣 on the matrix 𝑅 defined as equation (38): 𝑅 = 𝑅𝑣 × 𝐼4×4 (38) the fitness function of the ga uses the quadrotor motion rmse of the trajectory tracking according to the trajectory described in equation (35). the accomplishment of the ga results in the minimum rmse of the tracking error with the parameters 𝑄 and 𝑅 as mentioned in equation (39): the control parameters obtained from the ga are then simulated in tracking. the results of the simulation can be seen in figure 4. simulation results show an rmse value of 4.5429 m. it can be concluded that the ga improves quadrotor tracking performance by 2.5791, or by 36 %. it can be seen in the simulation results of trajectory tracking using the best trial and error parameters (figure 3a) that the movement of quadrotor has a considerable difference to the path (rmse 7.122 m). in addition, there is a slight delay so that when the path turns the quadrotor does not immediately follow. after optimization using ga (figure 4a), it can be seen that 𝑄 = ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ 1.21𝑒 + 7 0 0 0 0 0 0 0 0 0 0 0 0 11.75𝑒 + 5 0 0 0 0 0 0 0 0 0 0 0 0 2.67𝑒 + 04 0 0 0 0 0 0 0 0 0 0 0 0 30.24 0 0 0 0 0 0 0 0 0 0 0 0 51.00 0 0 0 0 0 0 0 0 0 0 0 0 46.84 0 0 0 0 0 0 0 0 0 0 0 0 9.64 0 0 0 0 0 0 0 0 0 0 0 0 38.85 0 0 0 0 0 0 0 0 0 0 0 0 98.49 0 0 0 0 0 0 0 0 0 0 0 0 68.99 0 0 0 0 0 0 0 0 0 0 0 0 2.05 0 0 0 0 0 0 0 0 0 0 0 0 1.58𝑒 + 02⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤ 𝑅𝑣 = 8.14 × 10 −5 (39) e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 7 the quadrotor movement is closer to the tracking path. c. swarm simulation the higher-level controller has seven parameters that must be chosen properly to produce swarming with fast aggregation. the selection of these parameters requires a separate discussion. in this paper, it is assumed that these parameters have been obtained properly using ga. the optimal higherlevel control parameters for swarm models and flocking simulations are specified as 𝑎 = 1, 𝑏 = 10, 𝑐 = 3 , 𝑘𝑎 = 0.7779, 𝑘𝑏 = 4.3194, 𝑘𝑣 = 2.4428 , and 𝑘𝑓 = 1.4214 . the trajectory of the swarm center using the above parameters is shown in figure 5. flocking simulation results using these parameters are shown in figure 6. the movement of uav quadrotor agents in a swarm is shown by colors: red, (a) (b) figure 1. (a) quadrotor at the artificial intelligence, control and automation laboratory-itb; (b) the dynamics of a quadrotor figure 2. higher-level and lower-level controllers in a swarm control system (a) (b) figure 3. (a) path tracking using lqr parameters based on the trial and error method; (b) pitch angle, roll, and yaw tracking simulation with lqr parameters based on the trial and error method e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 8 yellow, blue, green, light blue, and purple. in addition, the center of the swarm is represented by a black “×” sign, and a steady-state line is represented by a black line. rmse is calculated by looking at the difference between the distance of the swarm center movement and the line equation when the swarm system has reached a steady-state. the simulation application of lqr parameters for swarm system simulation uses the best trial and error results, namely, 𝑄 = 1000 × 𝐼12×12 and 𝑅 = 0.001 × 𝐼4×4 shown in figure 6. the lqr using the trial and error method produces an rmse of the swarm model of 0.2365 m. after that, a swarm model simulation is performed using the lqr (a) (b) figure 4. (a) path tracking using lqr parameters based on the genetic algorithm; (b) pitch angle, roll, and yaw tracking simulation with lqr parameters based on the genetic algorithm figure 5. swarm center movement using optimal parameters by the genetic algorithm (a) (b) figure 6. (a) swarm agent movement using lqr parameters from the trial and error method; (b) swarm agent movements and tracking trajectories using lqr parameters from the trial and error method e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 9 parameters obtained from gas. the simulation results can be seen in figure 7, this parameter produces a system rmse of 0.1959. the swarm model performance improvement was 0.0406, or 17.17 %. in figure 7a, it can be seen that agent aggregation using lqr parameters is faster than the aggregation of agents before optimization (figure 6a). aggregation of agents in the simulation before optimization occurs around a height of 40 m, whereas agent aggregation in the simulation after optimization occurs around a height of 45 m. this faster aggregation is caused by the quadrotor’s quick response to the tracking of the path produced by the swarm model. it can also be seen in figure 7b that the movement of each quadrotor agent follows the tracking path provided by the swarm model better after the lqr is optimized with the ga, although this can have a large enough effect if the swarm target moves to produce a more complicated trajectory. the summary of the improved performance is given in table 1. iv. conclusion tuning the weighting matrices of lqr is difficult by using the trial and error method because the nature of the system is random and complicated. hence, it is difficult to find the best parameters as the amount of value sought is in a large range. this paper considered the tracking control optimization of the lqr weighting matrices in the swarm control system to produce quadrotor unmanned flocking vehicles with ga optimization. the weighting matrix optimization using the ga improved the performance of the swarm control system: in tracking performance, 4.5429 m (rmse) improved by 2.5791 m (36.00 %); flocking aggregation 0.1959 m (rmse) improved by 0.0406 m (17.17 %), and flocking speed at height 45 m means 5 m (12.50 %) faster. acknowledgement this work was partially supported by itb research program, institut teknologi bandung. the authors would like to thank institut teknologi bandung for providing research facilities to complete the research. declarations author contribution all authors contributed correspondingly as the main contributor to this paper. all authors read and endorsed the final paper. funding statement this research did not receive any particular grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] t. sudiyanto, m. muljowidodo, and a. budiyono, “first principle approach to modeling of primitive quad rotor,” international journal of aeronautical and space sciences, vol. 10(2), pp.148-160, 2009. [2] p. pounds, r. mahony, j. gresham, p. corke, and j.m. roberts, “towards dynamically-favourable quad-rotor aerial robots,” in proceedings of the 2004 australasian conference on robotics & automation. australian robotics & automation association, 2004. (a) (b) figure 7. (a) swarm agent movement using lqr parameters generated by the genetic algorithm. (b) agent swarm movements and tracking trajectories using lqr parameters generated by the genetic algorithm table 1. simulation results and performance description lqr tracking (rmse in m) flocking aggregation (rmse in m) flocking speed at height (m) trial error 7.1220 0.2365 40 genetic algorithm 4.5429 0.1959 45 improvement 2.5791 (36.00 %) 0.0406 (17.17 %) 5 (12.50 %) http://dx.doi.org/10.5139/ijass.2009.10.2.148 http://dx.doi.org/10.5139/ijass.2009.10.2.148 http://dx.doi.org/10.5139/ijass.2009.10.2.148 http://dx.doi.org/10.5139/ijass.2009.10.2.148 http://www.araa.asn.au/acra/acra2004/papers/pounds.pdf http://www.araa.asn.au/acra/acra2004/papers/pounds.pdf http://www.araa.asn.au/acra/acra2004/papers/pounds.pdf http://www.araa.asn.au/acra/acra2004/papers/pounds.pdf http://www.araa.asn.au/acra/acra2004/papers/pounds.pdf e. joelianto et al. / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 1-10 10 [3] t. bresciani, “modelling, identification and control of a quadrotor helicopter,” msc theses, lund university, 2008. [4] a. kushleyev, d. mellinger, c. powers, and v. kumar, “towards a swarm of agile micro quadrotors,” autonomous robots, vol. 35(4), pp. 287-300, 2013. [5] j. leonard, al savvaris, and a. tsourdos, “towards a fully autonomous swarm of unmanned aerial vehicles,” in proceedings of 2012 ukacc international conference on control, pp. 286-291. ieee, 2012. [6] c.w. reynolds, “flocks, herds and schools: a distributed behavioral model,” in proceedings of the 14th annual conference on computer graphics and interactive techniques, pp. 25-34, august 1987. [7] a.e. turgut, h. çelikkanat, f. gökçe, and e. şahin, “selforganized flocking in mobile robot swarms,” swarm intelligence, vol. 2(2-4), pp. 97-120, 2008. [8] e. ferrante, a.e. turgut, c. huepe, a. pinciroli, and m. dorigo, “self-organized flocking with a mobile robot swarm: a novel motion control method,” adaptive behavior, vol. 20(6), pp. 460-477, 2012. [9] s. ramroop, f. arvin, s. watson, j. carrasco-gomez, and b. lennox, “a bio-inspired aggregation with robot swarm using real and simulated mobile robots,” in annual conference towards autonomous robotic systems 2018, springer, cham., pp. 317-329, 2018. [10] e. joelianto, a. qurthobi, “optimal control design for a formation tracking with leader-follower concept of multiagent autonomous helicopter model,” proceedings of international conference on intelligent unmanned systems, vol. 7, 2011. [11] e. joelianto, and a. sagala, “swarm tracking control for flocking of a multi-agent system,” ieee conference on control, systems & industrial informatics, pp. 75-80, september 2012. [12] e. de vries, and k. subbarao, “cooperative control of swarms of unmanned aerial vehicles,” 49th aiaa aerospace sciences meeting including the new horizons forum and aerospace exposition, pp. 78, january 2011. [13] z. hou, w. wang, g. zhang, and c. han, “a survey on the formation control of multiple quadrotors,” in 2017 14th international conference on ubiquitous robots and ambient intelligence (urai), pp. 219-225. ieee, 2017. [14] hönig, j.a. preiss, t.s. kumar, g.s. sukhatme, and n. ayanian, “trajectory planning for quadrotor swarms,” ieee transactions on robotics, vol. 34(4), pp. 856-869, 2018. [15] miswanto, h. pranoto, and d.m. muhammad, “the collective behavior of multi-agents system for tracking a desired path,” international journal of basic & applied sciences ijbas-ijens, vol. 11, pp. 81-86, 2011. [16] a. trizuljak, f. duchoň, j. rodina, a. babinec, m. dekan, and r. mykhailyshyn, “control of a small quadrotor for swarm operation,” journal of electrical engineering, vol. 70(1), pp. 315, 2019. [17] k. choutri, m. lagha, l. dala, and m. lipatov, “quadrotors uavs swarming control under leader-followers formation,” in 2018 22nd international conference on system theory, control and computing (icstcc), pp. 794-799. ieee, 2018. [18] i. m. lazim, a.r. husain, n.a.m. subha, z. mohamed, and m.a. m. basri, “optimal formation control of multiple quadrotors based on particle swarm optimization,” in asian simulation conference, pp. 121-135. springer, singapore, 2017. [19] d. das, g. gurrala, and u.j. shenoy, “linear quadratic regulator-based bumpless transfer in microgrids,” ieee transactions on smart grid, vol. 9(1), pp. 416-425, 2016. [20] z. ge, y. wang, and m. lv, “three-dimensional trajectory tracking guidance law based on linear quadratic regulator,” journal of physics: conference series, vol. 1039(1), p. 012042. iop publishing, 2018. [21] l. cao, s. tang, and d. zhang, “flight control for air-breathing hypersonic vehicles using linear quadratic regulator design based on stochastic robustness analysis,” frontiers of information technology & electronic engineering, vol. 18(7), pp. 882-897, 2017. [22] m. i̇çen, a. ateş, and c. yeroğlu, “optimization of lqr weight matrix to control three degree of freedom quadcopter,” in 2017 international artificial intelligence and data processing symposium (idap), pp. 1-6. ieee, 2017. [23] e. okyere, a. bousbaine, g.t. poyi, a.k. joseph, and j.m. andrade, “lqr controller design for quad-rotor helicopters,” the journal of engineering, no. 17, pp. 4003-4007, 2019. [24] b.d. anderson. and j.b. moore, “optimal control: linear quadratic methods,” dover publications, inc., new york, 2007. [25] e. joelianto, “linear quadratic control: a state space approach,” itb press, 2017. [26] j.m. ahmed, “optimal tuning linear quadratic regulator for gas turbine by genetic algorithm using integral time absolute error,” international journal of electrical & computer engineering, vol. 10(2), pp. 1367-1375, 2020. [27] m. ali, s.t. zahra, k. jalal, a. saddiqa, and m.f. hayat, “design of optimal linear quadratic gaussian (lqg) controller for load frequency control (lfc) using genetic algorithm (ga) in power system,” international journal of engineering works, vol. 5(3), pp. 40-49, 2018. [28] h. asadi, s. mohamed, c.p. lim, and s. nahavandi, “robust optimal motion cueing algorithm based on the linear quadratic regulator method and a genetic algorithm,” ieee transactions on systems, man, and cybernetics: systems, vol. 47(2), pp. 238-254, 2016. [29] g.b. raharja, g.b. kim, and k.j. yoon, “design of an autonomous hover control system for a small quadrotor,” international journal of aeronautical and space sciences, vol. 11(4), pp. 338-344, 2010. [30] v. gazi, and k.m. passino, “stability analysis of social foraging swarms,” ieee transactions on systems, man, and cybernetics—part b: cybernetics, vol. 34(1), pp. 539-557, 2004. [31] v. gazi, and k.m. passino, “a class of attractions/repulsion functions for stable swarm aggregations,” international journal of control, vol. 77(18), pp. 1567-1579, 2004. [32] v. gazi, and k.m. passino, “stability analysis of swarms,” ieee transactions on automatic control, vol. 48(4), pp. 692-697, 2003. [33] k.m. passino, “biomimicry for optimization, control, and automation,” springer science and business media, 2005. [34] g. lindfield, and j. penny, “numerical methods: using matlab,” 4th ed., academic press, 2018. [35] r.c. chakraborty, “fundamentals of genetic algorithms,” reproduction, 22, p. 35, 2010. [36] s. mirjalili, “genetic algorithm. in evolutionary algorithms and neural networks,” springer, pp. 43-55, 2019. http://lup.lub.lu.se/luur/download?func=downloadfile&recordoid=8847641&fileoid=8859343 http://lup.lub.lu.se/luur/download?func=downloadfile&recordoid=8847641&fileoid=8859343 https://doi.org/10.1007/s10514-013-9349-9 https://doi.org/10.1007/s10514-013-9349-9 https://doi.org/10.1007/s10514-013-9349-9 https://doi.org/10.1109/control.2012.6334644 https://doi.org/10.1109/control.2012.6334644 https://doi.org/10.1109/control.2012.6334644 https://doi.org/10.1109/control.2012.6334644 https://doi.org/10.1145/37402.37406 https://doi.org/10.1145/37402.37406 https://doi.org/10.1145/37402.37406 https://doi.org/10.1145/37402.37406 https://doi.org/10.1007/s11721-008-0016-2 https://doi.org/10.1007/s11721-008-0016-2 https://doi.org/10.1007/s11721-008-0016-2 https://doi.org/10.1177/1059712312462248 https://doi.org/10.1177/1059712312462248 https://doi.org/10.1177/1059712312462248 https://doi.org/10.1177/1059712312462248 https://doi.org/10.1007/978-3-319-96728-8_27 https://doi.org/10.1007/978-3-319-96728-8_27 https://doi.org/10.1007/978-3-319-96728-8_27 https://doi.org/10.1007/978-3-319-96728-8_27 https://doi.org/10.1007/978-3-319-96728-8_27 http://ojs.unsysdigital.com/index.php/icius/article/view/364 http://ojs.unsysdigital.com/index.php/icius/article/view/364 http://ojs.unsysdigital.com/index.php/icius/article/view/364 http://ojs.unsysdigital.com/index.php/icius/article/view/364 http://ojs.unsysdigital.com/index.php/icius/article/view/364 https://doi.org/10.1109/ccsii.2012.6470477 https://doi.org/10.1109/ccsii.2012.6470477 https://doi.org/10.1109/ccsii.2012.6470477 https://doi.org/10.2514/6.2011-78 https://doi.org/10.2514/6.2011-78 https://doi.org/10.2514/6.2011-78 https://doi.org/10.2514/6.2011-78 https://doi.org/10.1109/urai.2017.7992717 https://doi.org/10.1109/urai.2017.7992717 https://doi.org/10.1109/urai.2017.7992717 https://doi.org/10.1109/urai.2017.7992717 https://doi.org/10.1109/tro.2018.2853613 https://doi.org/10.1109/tro.2018.2853613 https://doi.org/10.1109/tro.2018.2853613 http://ijens.org/vol%2011%20i%2001/116701-3838%20ijbas-ijens.pdf http://ijens.org/vol%2011%20i%2001/116701-3838%20ijbas-ijens.pdf http://ijens.org/vol%2011%20i%2001/116701-3838%20ijbas-ijens.pdf http://ijens.org/vol%2011%20i%2001/116701-3838%20ijbas-ijens.pdf https://doi.org/10.2478/jee-2019-0001 https://doi.org/10.2478/jee-2019-0001 https://doi.org/10.2478/jee-2019-0001 https://doi.org/10.2478/jee-2019-0001 https://doi.org/10.1109/icstcc.2018.8540747 https://doi.org/10.1109/icstcc.2018.8540747 https://doi.org/10.1109/icstcc.2018.8540747 https://doi.org/10.1109/icstcc.2018.8540747 https://doi.org/10.1007/978-981-10-6463-0_11 https://doi.org/10.1007/978-981-10-6463-0_11 https://doi.org/10.1007/978-981-10-6463-0_11 https://doi.org/10.1007/978-981-10-6463-0_11 https://doi.org/10.1109/tsg.2016.2580159 https://doi.org/10.1109/tsg.2016.2580159 https://doi.org/10.1109/tsg.2016.2580159 https://doi.org/10.1088/1742-6596/1039/1/012042 https://doi.org/10.1088/1742-6596/1039/1/012042 https://doi.org/10.1088/1742-6596/1039/1/012042 https://doi.org/10.1088/1742-6596/1039/1/012042 https://doi.org/10.1631/fitee.1601363 https://doi.org/10.1631/fitee.1601363 https://doi.org/10.1631/fitee.1601363 https://doi.org/10.1631/fitee.1601363 https://doi.org/10.1631/fitee.1601363 https://doi.org/10.1109/idap.2017.8090164 https://doi.org/10.1109/idap.2017.8090164 https://doi.org/10.1109/idap.2017.8090164 https://doi.org/10.1109/idap.2017.8090164 https://ieeexplore.ieee.org/document/8737094 https://ieeexplore.ieee.org/document/8737094 https://ieeexplore.ieee.org/document/8737094 https://books.google.co.id/books/about/optimal_control.html?id=fw6tawaaqbaj&source=kp_book_description&redir_esc=y https://books.google.co.id/books/about/optimal_control.html?id=fw6tawaaqbaj&source=kp_book_description&redir_esc=y http://sinta.ristekbrin.go.id/affiliations/detail?page=20&view=books&id=379 http://sinta.ristekbrin.go.id/affiliations/detail?page=20&view=books&id=379 http://doi.org/10.11591/ijece.v10i2.pp1367-1375 http://doi.org/10.11591/ijece.v10i2.pp1367-1375 http://doi.org/10.11591/ijece.v10i2.pp1367-1375 http://doi.org/10.11591/ijece.v10i2.pp1367-1375 http://doi.org/10.5281/zenodo.1193795 http://doi.org/10.5281/zenodo.1193795 http://doi.org/10.5281/zenodo.1193795 http://doi.org/10.5281/zenodo.1193795 http://doi.org/10.5281/zenodo.1193795 https://doi.org/10.1109/tsmc.2016.2523906 https://doi.org/10.1109/tsmc.2016.2523906 https://doi.org/10.1109/tsmc.2016.2523906 https://doi.org/10.1109/tsmc.2016.2523906 https://doi.org/10.1109/tsmc.2016.2523906 https://doi.org/10.5139/ijass.2010.11.4.338 https://doi.org/10.5139/ijass.2010.11.4.338 https://doi.org/10.5139/ijass.2010.11.4.338 https://doi.org/10.5139/ijass.2010.11.4.338 https://doi.org/10.1109/tsmcb.2003.817077 https://doi.org/10.1109/tsmcb.2003.817077 https://doi.org/10.1109/tsmcb.2003.817077 https://doi.org/10.1080/00207170412331330021 https://doi.org/10.1080/00207170412331330021 https://doi.org/10.1080/00207170412331330021 https://doi.org/10.1109/tac.2003.809765 https://doi.org/10.1109/tac.2003.809765 https://doi.org/10.1109/tac.2003.809765 https://doi.org/10.1007/b138169 https://doi.org/10.1007/b138169 http://dl.booktolearn.com/ebooks2/science/mathematics/9780128122563_numerical_methods_5964.pdf http://dl.booktolearn.com/ebooks2/science/mathematics/9780128122563_numerical_methods_5964.pdf https://www.myreaders.info/09_genetic_algorithms.pdf https://www.myreaders.info/09_genetic_algorithms.pdf https://doi.org/10.1007/978-3-319-93025-1_4 https://doi.org/10.1007/978-3-319-93025-1_4 introduction ii. materials and methods a. quadrotor mathematical model b. swarm model c. quadrotor tracking d. a two-level swarm control system 1) lower-level control 2) higher-level control iii. results and discussions a. determination of trial and error parameters b. parameter optimization using genetic algorithm swarm simulation iv. conclusion acknowledgement declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.147-156 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: e.r. arboleda, “design, construction, and evaluation of transformer-based orbital shaker for coffee micropropagation,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 147-156, dec. 2022. design, construction, and evaluation of transformer-based orbital shaker for coffee micropropagation edwin romeroso arboleda department of computer and electronics engineering, cavite state university indang, cavite, philippines received 21 february 2021; 1st revision 20 july 2022; 2nd revision 17 september 2022; 3rd revision 6 october 2022; accepted 10 october 2022; published online 29 december 2022 abstract this study offers a novel solution to deal with the complicated electronic circuitry for speed controller and too complex mechanical design of rotating mechanism of an orbital shaker. the developed prototype used a transformer that varies the supply voltage to control the speed of rotation of the orbital shaker. the prototype has five speed levels which depend on the input voltage. these speeds are 180 rpm at 12 v, 258 rpm at 15 v, 360 rpm at 18 v, 427 rpm at 21 v, and 470 rpm at 24 v. the prototype was tested to run continuously for 48 hours for each speed level, with speed being measured every hour using a tachometer. statistical computation shows that the speed remains constant for the entire 48 hour period. evaluation of results shows that the speed controller and the novel mechanical design for the orbital shaking motion achieved their functions. for this reason, it can be concluded that the prototype is durable and safe for use in orbital shaking applications. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: dc motor; orbital shaker; rotating mechanism; speed controller; step-down transformer. i. introduction in many scientific applications, the job of stirring or mixing containers such as beakers and flasks containing various liquids is performed by the orbital shaker [1]. one specific application of the orbital shaker is to stir cultures growing in beakers in constant orbital motion which will provide for the controlled growth of the cultures in the interior environment of the beakers [2]. the gentle, circular, uniform agitation in a controlled velocity is important to maintain a similar growth rate among batches of culture in different containers [3] [4]. orbital shakers have been used in different areas where agitation is necessary, ranging from medicines to agriculture [5]. shaking bioreactors have been used to cultivate microorganisms since the turn of the century. different types of reactor systems are classified as shakers with orbital motion or linear reciprocal movement. linear reciprocal shaking motion was employed often in the past, but has waned in the last decade [6]. the mechanism of orbital shakers consists of a motor coupled to a platform. the orbit is attached to the motor and as the motor rotates in a circular motion, the orbit shakes the contents of the vessel. an orbital shaker's whole platform travels in a circular orbit. a number of orbital shaker designs that use the orbit-coupled-to-motor principle are available in open-source repositories such as the nih 3d print exchange [6], thingiverse [7], and prusa printers [8]. the commercially available orbital shakers [9] also use the orbit-coupled-tomotor principle. the orbital shaker can be considered as the most important electronic equipment in tissue culture and the costliest. in coffee tissue culture, the orbital shaker is used to separate shoots from the mother callus by shaking for 24-48 hours. browsing the product catalogs of suppliers of orbital shakers on the internet shows that its prices (for 48 flasks capacity) range from hundreds of thousands of pesos, not to mention that all these suppliers are outside the philippines. with the advent of social media and online training courses, many people are venturing into * corresponding author. tel: +63-9171246950 e-mail address: edwin.r.arboleda@cvsu.edu.ph https://dx.doi.org/10.14203/j.mev.2022.v13.147-156 https://dx.doi.org/10.14203/j.mev.2022.v13.147-156 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.147-156 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.147-156&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:edwin.r.arboleda@cvsu.edu.ph e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 148 home tissue culture. gone are the days when people thought that tissue culture was exclusively done in clean, sophisticated dust-free laboratories. there were many social media groups whose members reportedly were successful in-home tissue cultures. one example is the tissue culture of philodendron species [10] [11] [12]. this plant species is one of the most expensive plants in the exotic plant hobby but is now being propagated using tissue culture resulting in a major reduction in its price. coffee is a major agricultural product and second in ranking as the most important export next to crude oil in the world market. many farmers all over the world depend on coffee farming as their main source of livelihood. coffee is a food product that is most commercialized and vastly consumed in the whole world [13] [14]. cavite province is one of the top producers of coffee in the philippines, that is the reason why the national coffee research and extension center (ncrdec) is located in the cavite state university. ncrdec is one the pioneers in coffee tissue culture in the philippines. ncrdec has been successful in tissue culture of coffee and sharing this knowledge with coffee farmers is one of the objectives of the center. tissue culture is the process of growing tissues or cells apart from the parent organism. another name for this method is micropropagation. a liquid, semi-solid, or solid growth medium, such as broth or agar, is generally used [15]. plant tissue culture is the process of cultivating plant seeds, organs, explants, tissues, cells, or protoplasts on a synthetic nutritional medium with chemically specified nutrients under sterile and regulated lighting, temperature, and humidity conditions [16] [17]. the researcher envisioned through this study and with the cooperation of ncrdec to design a low-cost orbital shaker and freely share this design with cooperatives and, most importantly, small-time coffee farmers who want to venture into the coffee micropropagation or tissue culture. the researcher made the design as simple as possible, both in its mechanical and electronic aspects, so that it can be a “build-it-yourself study” for those interested in developing their own. ii. materials and methods the conceptual model shown in figure 1 served as the guide of the researcher in the conduct of the study. the input serves as the basis for how the whole system was laid out. the process part of the conceptual model deals with how the ideas and concepts in the input were transformed into actual functioning parts of the system. after combining all the processes, a functioning model of the device was created. to determine the device’s accuracy, practicality, and acceptability, it was subjected to a series of evaluations. the system block is shown in figure 2. it is composed of power supply, motor controller, input selector, motor and orbital shaker platform. knowl edge requirements: • rpm range of orbital shaker use for coffee ti ssue culture • mechanical design of the orbital shaker • motor and variable speed controller ty pes: specif ication and capabiliti es a. • proper choice of motor and variable speed controller • design • breadboard lay out • pcb layout • testing b. • mechanical design of the platform and shaking mechanis m for the shak er • can vassing and purchase of the materials • fabrication orbi tal s haker f or coffee micropropagation s tudy • pilot testing • cost co mputati on input process output evaluation figure 1. conceptual model power supply variable speed motor controller motor orbi tal s haker rotating mechanis m and platform displ ay input selector figure 2. block diagram e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 149 a. design of the platform the orbital shaker’s platform was patterned on the orbital shaker currently being used at ncrdec located in cavite state university, indang, cavite, philippines. the dimension of the platform is 85.09 cm x 65.41 cm, as shown in figure 3. it was folded 2.54 cm on every side. the gap between the folds in every corner was welded. five holes with a 2 cm diameter were drilled on the platform. the placement of the holes is shown in figure 4. one hole is located in the middle of the platform, in which the hole’s center was placed 32.7 cm and 42.55 cm from the upper left corner of the platform, as shown in figure 4. four holes were drilled equidistantly from the four corners at 10.67 cm and 10.92 cm, as shown in figure 4. figure 5 is the pictorial diagram of figure 4, in which one screw was drilled in the center of the platform and four screws were drilled at the same distance from the four corners. the hole in the center holds the screw that connects the top platform to the rotating orbital shaking mechanism at the bottom. the four holes are for screws that stabilize the platform on a flat level while it rotates in an orbital shaking motion. the five screws used in the platform were sourced from a screw hardware store. it is a specialized screw commonly used for securing a clear glass tabletop to a table frame. the screw has two parts, the top part that contains the head and the bottom part. the two parts are detachable from one another. it was designed so that a glass of different thicknesses could be placed in the middle of the two parts. the screw also has a hole in the bottom part, which is very important because it is where the rotating orbital mechanism was to be inserted. as shown in figure 6, the screw has a 2 cm diameter and an overall length of 4.54 cm. the top part has a length of 1 cm, and the bottom part has a 2.54 cm length. this means that variable thicknesses of material can be placed between them. attached to the four screws are a stainless circular disc and a plastic spacer with a 2 cm diameter and 1 cm length. the circular disk is 8 cm in diameter. figure 6 shows the head of the screw, the space in which the platform will be placed, the plastic spacer, the circular disc, and the bottom part of the screw. figure 7 shows the actual pictorial diagram of the screws. it can be seen in figure 7 that the platform was placed between the head of the screw on the top and the blue plastic spacer, then followed by the circular disc and the bottom part of the screw securing them together. as shown in figure 8, the screws are for fitting inside the spring. the purpose of the circular discs is to prevent the underside of the platform from touching the springs and to provide the space to keep the platform in a level position. the springs serve several purposes; aside from keeping the four corners of the platform level, the springs also prevent the screws from overshooting. four screws figure 3. dimensions of the platform figure 4. top view of the platform figure 6. the screw figure 7. pictorial diagram of the screws figure 5. bottom view of the platform e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 150 and four springs were placed, as shown in figure 9. the springs have a diameter of 4 cm and their center were placed at 10.67 cm and 10.92 cm from every corner, as shown in figure 9. figure 10 is the pictorial diagram showing the actual placement of the springs. the four springs were welded in a metal bar with the same distance from every corner. the spring has a 5 cm height, as shown in figure 11. the 5 cm height is just enough to maintain the height of the platform when it is fully loaded with samples. as shown in figure 12, the screws are to be inserted into the spring. the diameter of the spring is dependent on the diameter of the screw and the size of the orbit of the rotating mechanism. b. design of the frame the frame dimensions are shown in figure 13. it has an 85.09 cm length, 59.69 cm width, and 59.69 cm height. it was made from a 2.54 cm metallic figure 10. pictorial diagram of placement figure 11. spring height figure 12. the platform on the top of the frame figure 13. dimensions of the frame figure 8. the screws are to be inserted at the spring figure 9. placement of the springs e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 151 angle bar and welded together. the front view and side view of the frame is shown in figure 14 and figure 15, respectively. it can be seen in figure 14 and figure 15 that high-grade stainless steel was used as the material for the prototype. this is not only for aesthetic purposes but also for easy cleaning. the stainless-steel plates were screwed to the metallic frame. c. design of the rotating mechanism the rotating mechanism is shown in figure 16. it is composed primarily of a bull bar fabricated at the machine shop for it to fit at the holes of the pulley and the two bearings. on the topmost part of the rotating mechanism, a nail was welded 0.45 cm from the center. the nail ensures that the rotating mechanism is securely fastened to the top platform by inserting it at the bottom hole of the middle screw. the actual rotating mechanism is shown in figure 17. the rotating mechanism is composed of the dc motor with a pulley, a tubular bar inserted into a pulley, a bearing on the lower end of the tubular bar, and a belt. when the dc motor rotates, the pulley attached to it pulls the belt attached to the tubular bar. the tubular bar is tightly secured by the bearing on the lower end, which also rotates as the pulley rotates. on top of the tubular bar is a 2 cm long nail welded 0.3 cm from the center. there are two pulleys used in the orbital shaker, as shown in figure 18. the drive pulley (right) was fastened to the dc motor and the driven pulley was fastened to the rotating mechanism. the actual picture of the rotating mechanism is shown in figure 19. the drive and driven pulley arrangement allow for regulated speed control as compared to connecting the orbit composed of the nail directly on top of the dc motor. also, this arrangement was designed for a small orbit like the 0.3 cm diameter orbit used in this prototype. d. design of the holder the holder secures the erlenmeyer flask to the platform. it is made from 2.54 cm wide and 22 cm long stainless-steel sheet cut and folded, as shown in figure 20. the holder is composed of 2 stainless steel sheets placed on top of one another and secured by a screw in the platform. the orbital shaker is composed of 48 pairs-ofholder. the pictorial diagram of the holder is shown in figure 21. the holder tightly secures the erlenmeyer flasks in an upright position as the platform rotates in orbital motion. the orbital movement of the platform makes the liquid inside the erlenmeyer flasks stirred in a constant speed circular movement. figure 14. side view of the shaker figure 15. front view of the shaker figure 16. rotating mechanism e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 152 e. design of the speed control figure 22 shows the schematic diagram of a speed controller for the orbital shaker. a customized 3 a variable transformer was used with secondary windings 24 v, 21 v, 18 v, 15 v, and 12 v. the transformer was connected to four diodes (1n5400) that formed the bridge and the ripple was filtered by two 4700 µf capacitors and a 1 kω resistor. the capacitor passes ac and rejects dc, thus filtering dc voltage. the use of a resistor is for to stabilize the time constant of the circuit and reduce the charging and discharging time of the circuit output. it was connected to the dc motor and varying voltage is as easy as turning a knob. this speed control design is simple, and voltage setting adjustment is instant with just a turn of the knob. there are no problems encountered from high to low voltage adjustments and vice versa. f. dc motor this orbital shaker used a dc motor. dc motors are more costly than ac motors, but their speed drives are cheaper and use simpler figure 21. pictorial diagram of the holder figure 17. pictorial diagram of the rotating mechanism figure 18. the drive and driven pulley arrangement figure 19. pictorial diagram of the pulley arrangement figure 20. dimensions of the holder e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 153 circuits [18] [19] [20]. the speed of a dc motor is easier to control with simpler electronic circuits [21] [22] [23] as compared to ac motors that have complicated speed controllers [24] [25]. based on the data gathered, the speed 350 to 400 rpm can be achieved using the matsushita 24 volts, 3 amperes dc motor. iii. results and discussions table 1 shows the measured speed level in rpm when the platform is not attached to the rotating mechanism. because the rotating platform speed required for coffee tissue culture is within the range of 300 to 400 rpm, the developed prototype satisfied the speed requirement of the orbital shaker suitable for coffee micropropagation. a. cost computation the direct costs amounted to 10,110.15 pesos. the total cost of the study is the sum of the direct and indirect costs of the study, which is equal to 25,110 pesos. the cost of ncrdec shaker is 86,000 pesos. there is a 60,890 pesos difference between ncrdec shaker and the low-cost orbital shaker developed by the proponent. b. evaluation of the orbital shaker the evaluation has three phases: the pilot test, the performance test, and the final test. the pilot test involves the presentation of the device to the tissue culturists and the director of ncrdec. during this test, the researcher explained the design of the device and demonstrated the functions of the control. the orbital shaker was loaded with erlenmeyer flasks containing coffee tissue culture and the different speed levels were tested to see if the shaking of the media inside the flasks was orbital. since the coffee micropropagation process involves shaking the culture media for a maximum of 48 hours, the orbital shaker was operated for 48 hours continuously at its maximum speed level. after the 48-hour test period, the device was presented again to ncrdec tissue culturists and they were all convinced of the durability of the shaker. seeing that the device is durable, as confirmed by the pilot test, ncrdec adviser suggested that the device’s reliability needs to be tested as well. the performance test is designed to determine the relationship between shaft speed in relation to the 48 hours operation time. the performance test involves operating the orbital shaker for 48 hours and measuring the speed every hour for speed levels 1 to 5. the final test involves loading the low-cost orbital shaker with 48 pieces of erlenmeyer flasks containing coffee tissue culture media. using speed level 3 (the equivalent speed used by ncrdec shaker), the device was operated for 48 hours. after the final test and being convinced of the reliability and durability of the low-cost orbital shaker, a certificate of user acceptance was signed by the director and all the tissue culturists of the center. the low-cost orbital shaker was endorsed by the director of ncrdec to be used in its coffee micropropagation study. c. performance of speed level 1 to 5 in order to determine if the orbital shaking mechanism of the prototype maintains a constant speed, it was operated for 48 hours for every speed level. the 48 hour is the time used in coffee micropropagation to separate the new coffee plants from the mother callous. the speed level 1 to 5 of the developed prototype was evaluated by measuring and recording the shaft speed per hour using a digital tachometer. with the top platform removed, the author placed the digital tachometer on the surface of the driven pulley to record its rotations per minute speed. the speed was measured per hour for 48 hours for speed levels 1 to 5. figure 23 shows the shaft speed of the orbital shaker for 48 hours for the five speed levels. for speed level 1, the range of shaft speed is 177 to 182 rpm. for speed level 2, the range of shaft speed is 254 to 261 rpm. for speed level 3, the range of shaft speed is 358 to 362 rpm. for speed level 4, the range of shaft speed is 425 to 430 rpm. for speed level 5, the range of shaft speed is 467 to 472 rpm. the regression lines for levels 1, 2, 3, and 5 slightly lean upward, while for speed level 2, the regression lines lean slightly downward. figure 22. schematic diagram of speed controller e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 154 (a) (b) (c) (d) (e) figure 23. scatter diagram with regression lines for speed: (a) level 1; (b) level 2; (c) level 3; (d) level 4; (e) level 5 e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 155 the data gathered were statistically analyzed using analysis of variance, as shown in table 2. for all speed levels, the computed 𝑓 is less than the pvalue at 𝑓 < 𝑓𝛼 ( 1, 𝑛 − 2 ), where 𝛼 = 0.05 the null hypothesis that there is no significant change in the shaft speed of the orbital shaker in relation to the 48 hours of operation of the shaker is accepted. this means that at speed levels 1 to 5, the orbital shaker maintained a constant speed for the whole 48-hour period. d. overall performance of the orbital shaker it can be noted that the test for all speed levels yields the same results. the statistical tests showed that for all speed levels, the orbital shaker maintained constant speed at a 95 % level of accuracy. iv. conclusion the prototype orbital shaker was designed and developed for the coffee micropropagation study of ncrdec, bancod, indang, cavite. the study has the objective of sharing the developed technology of a low-cost orbital shaker with farmers and cooperatives who want to venture into the tissue culture production of coffee seedlings. after the evaluation, the low-cost orbital shaker was found to be satisfactory, applicable, and recommended for use in the coffee micropropagation study. ncrdec’s previous experience led them to believe that orbital shakers are naturally expensive. however, through this study, it was proven that the sophisticated orbital shaking motion could be provided and controlled with an inexpensive dc motor. the researcher found out that the speed of orbital shaking motion was not solely dependent on the capability of the motor. there is a relationship that exists between the size of the orbit and the speed of the orbital shaking motion. with the same motor speed, a little increase in the orbit causes an increase in speed in the orbital shaking motion. the researcher recommends that further study should be done to determine that relation in the future. acknowledgements the author would like to thank cavite state university and the national coffee research center for supporting this research endeavour. declarations author contribution e.r. arboleda contributed as the main contributor of this paper. the author read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. table 1. speed range of the orbital shaker speed level input voltage to the dc motor (v) speed (rpm) 1 12 180 2 15 258 3 18 360 4 21 427 5 24 470 table 2. analysis of variance for speed levels 1 to 5 speed level sources of variation sum of squares degrees of freedom mean square computed 𝒇 p-value 1 regression 0.148610508 1 0.148610508 0.085610074 0.2131 error 79.85138949 46 1.7358997772 total 80 47 2 regression 0.28234911 1 0.28234911 0.126137277 0.2131 error 102.9676509 46 2.238427193 total 103.25 47 3 regression 0.104320452 1 0.104320452 0.106294574 0.2131 error 45.14567955 46 0.981427816 total 45.25 47 4 regression 0.169371472 1 0.169371472 0.084401527 0.2131 error 92.30979519 46 2.006734678 total 92.47916667 47 5 regression 0.169371472 1 0.169371472 0.101433518 0.2131 error 76.80979519 46 1.669778156 total 76.97916667 47 https://mev.lipi.go.id/ e.r. arboleda / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 147-156 156 publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] a. mohini, “microcontroller based orbital motion shaker,” in iciibms 2015, track 2: artificial intelligence, robotics and human-computer interaction, okinawa, japan microcontroller, pp. 115–120, 2015. [2] c. m. warboys, m. ghim, and p. d. weinberg, “understanding mechanobiology in cultured endothelium: a review of the orbital shaker method,” atherosclerosis, vol. 285, no. march, pp. 170–177, 2019. [3] j. nedbal, l. gao, and k. suhling, “bottom-illuminated orbital shaker for microalgae cultivation,” hardwarex, vol. 8, p. e00143, 2020. [4] p. alpresa et al., “orbitally shaken shallow fluid layers. ii. an improved wall shear stress model stress model,” phys. fluids, vol. 032108, 2018. [5] n. muller, p. girard, d. l. hacker, m. jordan, and f. m. wurm, “orbital shaker technology for the cultivation of mammalian cells in suspension,” biotechnol. bioeng., no. february, 2005. [6] w. klöckner and j. büchs, “advances in shaking technologies,” trends biotechnol., vol. 30, no. 6, pp. 307–314, 2012. [7] diybio orbital shaker v 1.0. available: https://www.thingiverse.com/thing:2633507. accessed may 11, 2022. [8] customized shaker platforms for diybio orbital shaker license. available: https://www.printables.com/model/33650customized-shaker-platforms-for-diybio-orbital-sha. accessed may 11, 2022. [9] orbital shaker literature review. available: https://www.appropedia.org/orbital_shaker_literature_review. accessed may 11, 2022. [10] a. a. alawaadh, y. h. dewir, m. s. alwihibi, a. a. aldubai, s. elhendawy, and y. naidoo, “micropropagation of lacy tree philodendron (philodendron bipinnatifidum schott ex endl.),” hortscience, vol. 55, no. 3, pp. 294–299, 2020. [11] m. lara-ascencio, m. andrade-rodríguez, d. guillén-sánchez, h. sotelo-nava, and o. g. villegas-torres, “establishment of in vitro aseptic culture of philodendron xanadu croat,” rev. cienc. agron., vol. 52, no. 2, pp. 1–9, 2021. [12] m. k. seliem, m. e. el-mahrouk, a. n. el-banna, y. m. hafez, and y. h. dewir, “micropropagation of philodendron selloum: influence of copper sulfate on endophytic bacterial contamination, antioxidant enzyme activity, electrolyte leakage, and plant survival,” south african j. bot., vol. 139, pp. 230–240, 2021. [13] e. r. arboleda, a. c. fajardo, and r. p. medina, “green coffee beans feature extractor using image processing,” telkomnika (telecommunication comput. electron. control.), vol. 18, no. 4, p. 2027, 2020. [14] e. r. arboleda, a. c. fajardo, and r. p. medina, “classification of coffee bean species using image processing, artificial neural network and k nearest neighbors,” 2018 ieee international conference on innovative research and development (icird), 2018. [15] c. l. encina and j. regalado, “aspects of in vitro plant tissue culture and breeding of asparagus: a review,” horticulturae, 8(5), 439, pp. 1–15, 2022. [16] h. chandran, m. meena, t. barupal, and k. sharma, “plant tissue culture as a perpetual source for production of industrially important bioactive compounds,” biotechnol. reports, vol. 26, p. e00450, 2020. [17] s. c. chun, j. gopal, s. iyyakannu, and m. muthu, “an analytical retrospection of mass spectrometric tools established for plant tissue culture: current endeavours and future perspectives,” trac trends anal. chem., vol. 126, p. 115843, 2020. [18] y. v. p. paulite, n. j. c. carandang, and e. r. arboleda, “smart wheelchair with dual control using touchpad and android mobile device,” indones. j. electr. eng. informatics, vol. 6, no. 1, pp. 86–96, 2018. [19] e. r. arboleda, m. c. t. alegre, and k. f. idica, “development of a low-cost electronic wheelchair with obstacle avoidance feature,” j. mechatronics, electr. power, veh. technol., vol. 6, no. 2, p. 89, 2015. [20] m. g. dizon, c. t. sevillano, and m. a. t. cabaluna, “design and development of rc railed robot for coffee nursery logistics,” j. mechatronics, electr. power, veh. technol., vol. 5, no. 2, pp. 107–114, 2014. [21] m. z. romdlony and f. irsyadi, “hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing,” j. mechatronics, electr. power, veh. technol., vol. 12, no. 2, pp. 81–86, 2021. [22] m. rif’an, f. yusivar, and b. kusumoputro, “sensorless-bldc motor speed control with ensemble kalman filter and neural network,” j. mechatronics, electr. power, veh. technol., vol. 10, no. 1, pp. 1–6, 2019. [23] c. r. lee, s. k. kim, and c. k. ahn, “auto-tuning proportionaltype synchronization algorithm for dc motor speed control applications,” ieee trans. circuits syst. ii express briefs, vol. 67, no. 3, pp. 521–525, 2020. [24] s. m. ali, v. v. k. reddy, and m. s. kalavathi, “analysis of coupled and decoupled pwm techniques for induction motor drive,” indones. j. electr. eng. informatics, vol. 7, no. 1, pp. 94– 103, 2019. [25] n. farah et al., “analysis and investigation of different advanced control strategies for high-performance induction motor drives,” telkomnika (telecommunication comput. electron. control.), vol. 18, no. 6, pp. 3303–3314, 2020. https://doi.org/10.1016/j.protcy.2016.05.079 https://doi.org/10.1016/j.protcy.2016.05.079 https://doi.org/10.1016/j.protcy.2016.05.079 https://doi.org/10.1016/j.protcy.2016.05.079 https://doi.org/10.1016/j.atherosclerosis.2019.04.210 https://doi.org/10.1016/j.atherosclerosis.2019.04.210 https://doi.org/10.1016/j.atherosclerosis.2019.04.210 https://doi.org/10.1016/j.atherosclerosis.2019.04.210 https://doi.org/10.1016/j.ohx.2020.e00143 https://doi.org/10.1016/j.ohx.2020.e00143 https://doi.org/10.1016/j.ohx.2020.e00143 https://doi.org/10.1063/1.5016343 https://doi.org/10.1063/1.5016343 https://doi.org/10.1063/1.5016343 https://doi.org/10.1002/bit.20358 https://doi.org/10.1002/bit.20358 https://doi.org/10.1002/bit.20358 https://doi.org/10.1016/j.tibtech.2012.03.001 https://doi.org/10.1016/j.tibtech.2012.03.001 https://www.thingiverse.com/thing:2633507 https://www.thingiverse.com/thing:2633507 https://www.thingiverse.com/thing:2633507 https://www.printables.com/model/33650-customized-shaker-platforms-for-diybio-orbital-sha https://www.printables.com/model/33650-customized-shaker-platforms-for-diybio-orbital-sha https://www.printables.com/model/33650-customized-shaker-platforms-for-diybio-orbital-sha https://www.printables.com/model/33650-customized-shaker-platforms-for-diybio-orbital-sha https://www.appropedia.org/orbital_shaker_literature_review https://www.appropedia.org/orbital_shaker_literature_review https://www.appropedia.org/orbital_shaker_literature_review https://doi.org/10.21273/hortsci14612-19 https://doi.org/10.21273/hortsci14612-19 https://doi.org/10.21273/hortsci14612-19 https://doi.org/10.21273/hortsci14612-19 https://doi.org/10.5935/1806-6690.20210024 https://doi.org/10.5935/1806-6690.20210024 https://doi.org/10.5935/1806-6690.20210024 https://doi.org/10.5935/1806-6690.20210024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.1016/j.sajb.2021.01.024 https://doi.org/10.12928/telkomnika.v18i4.13968 https://doi.org/10.12928/telkomnika.v18i4.13968 https://doi.org/10.12928/telkomnika.v18i4.13968 https://doi.org/10.12928/telkomnika.v18i4.13968 https://doi.org/10.1109/icird.2018.8376326 https://doi.org/10.1109/icird.2018.8376326 https://doi.org/10.1109/icird.2018.8376326 https://doi.org/10.1109/icird.2018.8376326 https://doi.org/10.1109/icird.2018.8376326 https://doi.org/10.3390/horticulturae8050439 https://doi.org/10.3390/horticulturae8050439 https://doi.org/10.3390/horticulturae8050439 https://doi.org/10.1016/j.btre.2020.e00450 https://doi.org/10.1016/j.btre.2020.e00450 https://doi.org/10.1016/j.btre.2020.e00450 https://doi.org/10.1016/j.btre.2020.e00450 https://doi.org/10.1016/j.trac.2020.115843 https://doi.org/10.1016/j.trac.2020.115843 https://doi.org/10.1016/j.trac.2020.115843 https://doi.org/10.1016/j.trac.2020.115843 https://doi.org/10.11591/ijeei.v6i1.342 https://doi.org/10.11591/ijeei.v6i1.342 https://doi.org/10.11591/ijeei.v6i1.342 https://doi.org/10.11591/ijeei.v6i1.342 https://dx.doi.org/10.14203/j.mev.2015.v6.89-96 https://dx.doi.org/10.14203/j.mev.2015.v6.89-96 https://dx.doi.org/10.14203/j.mev.2015.v6.89-96 https://dx.doi.org/10.14203/j.mev.2015.v6.89-96 https://dx.doi.org/10.14203/j.mev.2014.v5.107-114 https://dx.doi.org/10.14203/j.mev.2014.v5.107-114 https://dx.doi.org/10.14203/j.mev.2014.v5.107-114 https://dx.doi.org/10.14203/j.mev.2014.v5.107-114 https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 https://dx.doi.org/10.14203/j.mev.2019.v10.1-6 https://doi.org/10.1109/tcsii.2019.2915384 https://doi.org/10.1109/tcsii.2019.2915384 https://doi.org/10.1109/tcsii.2019.2915384 https://doi.org/10.1109/tcsii.2019.2915384 https://doi.org/10.11591/ijeei.v7i1.529 https://doi.org/10.11591/ijeei.v7i1.529 https://doi.org/10.11591/ijeei.v7i1.529 https://doi.org/10.11591/ijeei.v7i1.529 https://doi.org/10.12928/telkomnika.v18i6.15342 https://doi.org/10.12928/telkomnika.v18i6.15342 https://doi.org/10.12928/telkomnika.v18i6.15342 https://doi.org/10.12928/telkomnika.v18i6.15342 introduction ii. materials and methods a. design of the platform b. design of the frame c. design of the rotating mechanism d. design of the holder design of the speed control f. dc motor iii. results and discussions a. cost computation evaluation of the orbital shaker c. performance of speed level 1 to 5 d. overall performance of the orbital shaker conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: https://mev.lipi.go.id all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev is sinta 1 accredited by by ministry of research and technology, republic indonesia via national journal accreditation (arjuna) accreditation platform. https://sinta.ristekbrin.go.id/jo urnals/detail?id=814 postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: mev@mail.lipi.go.id https://mev.lipi.go.id/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://sinta.ristekbrin.go.id/journals/detail?id=814 mailto:mev@mail.lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: https://mev.lipi.go.id/mev/login need a username/password? go to registration at: https://mev.lipi.go.id/mev/user/r egister registration and login are required to submit items online and to check the status of current submissions. copy editing and pr oofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at https://mev.lipi.go.id. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. https://mev.lipi.go.id/mev/login https://mev.lipi.go.id/mev/user/register https://mev.lipi.go.id/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 editor-in-chief dr. haznan abimanyu dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences bandung 40135, indonesia asscociate editor (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi bandung, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia prof. tapan kumar saha electrical engineering, the university of queensland, australia prof. muhammad nizam, s.t, m.t, ph.d. department of mechanical engineering, universitas sebelas maret surakarta, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology, japan prof. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, indonesia prof. dr. bambang riyanto trilaksono school of electrical engineering and informatics, bandung institute of technology, indonesia prof. keum shik hong dept. of mechanical engineering, pusan national university, korea, republic of prof. taufik director of electric power institute, california polytechnique, united states prof. dr. adi soeprijanto dept. of electrical engineering, institut teknologi sepuluh nopember (its), indonesia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology, indonesia assoc. prof. hazim moria department of mechanical engineering, yanbu industrial college, saudi arabia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, australia assoc. prof. roonak daghigh university of kurdistandisabled, sanandaj, iran, islamic republic of asst. prof. mohammad h. yazdi mechanical eng. dept., islamic azad university, iran, islamic republic of dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales, australia dr. ahmad fudholi solar energy research institute, universiti kebangsaan malaysia, malaysia dr. ali h.a. al-waeli solar energy research institute, universiti kebangsaan malaysia, malaysia george anwar, ph.d. university of california, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia, indonesia riza muhida, ph.d. stkip surya, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia advisory editor prof. ocktaeck lim school of mechanical engineering, university of ulsan, korea, republic of prof. dr. endra joelianto engineering physics, bandung institute of technology, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 © 2021 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 foreword from editor-in-chief journal of mechatronics, electrical power, and vehicular technology (mev) has become an increasingly recognized journal in the past years and is an international journal indexed by many internationally recognized indexers greatly due to the dedicated efforts of the outstanding guest editors, the managing editors, and the advisory editors. in this issue, seven papers are published with the authors diversity came from indonesia, malaysia, russian federation, republic of maldives, saudi arabia, iraq, united arab emirates, taiwan, and australia. the papers come from multidisciplinary topics including mechatronics, electrical power, and vehicular technology. they may be classified as follows. one paper discusses a comparison of the characteristics of interior and inset types of pmms for electric vehicle applications to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. two papers talk about photovoltaic, one aims to validate the pv and outlet temperature for various mass flow rates and solar radiation by development a predictive model to perform a steady-state energy analysis of a pvt air collector, while the other evaluates the electrical characteristics of flexible solar panel for pv and pv with bifluid (air and water) cooling system by testing the integration of monocrystalline flexible solar panel into both systems under a fixed solar radiation. one paper presents a novel method of small local outdoor positioning system for localizing the area of dropping and landing of an autonomous vtol by utilizing the low-cost precision ultra-wide band (uwb) ranging system. the next paper discusses a simulation to determine the power factor of an electrical network can be done with proteus isis software by creating a phase detection circuit. the other two papers talk about microchannels and sensor fabrication. one of them aims to make a comprehensive study of fluid flow characteristics through a microchannel with several possible bends. while the other one describes the development of chemical sensors to detect polypyrrole (ppy) based phosphate sensors in doped di-ammonium hydrogen phosphate (dap) with thick film technology (tft). since the first volume, our journal provides discretion in financial term by waiving the article processing charge. we would like to acknowledge our immense gratitude to our international editorial board members, reviewers and authors. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2021 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 ii list of contents characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications pudji irasari, ketut wirtayasa, puji widiyanto, muhammad fathul hikmawan, muhammad kasim .............................................................................................................................................. 1-9 experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis ahmad fudholi, mariyam fazleena musthafa, goh li jin, rudi darussalam, ahmad rajani, andri setiawan, anwar, mohammad hossein yazdi, hazim moria, mohd yusof othman, mohd hafidz ruslan, kamaruzzaman sopian ......................................................................................... 10-17 local positioning system for autonomous vertical take-off and landing using ultrawide band measurement ranging system niam tamami, bambang sumantri, prima kristalina............................................................................ 18-27 proteus isis simulation for power factor calculation using zero crossing detector jumrianto, royan ............................................................................................................................................. 28-37 a review of single-phase pressure drop characteristics microchannels with bends endro junianto, jooned hendrarsakti ........................................................................................................ 38-44 phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology nofriyani, robeth viktoria manurung, aminuddin debataraja, indra dwisaputra ...................... 45-50 bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel nurul shahirah rukman, ahmad fudholi, putri adia utari, cheku nurul aisyah, andri joko purwanto, rakhmad indra pramana, erie martides, ant. ardath kristi, nilofar asim, mohammad hossein yazdi, hazim moria, husam abdulrasool hasan, zeki ahmed darwish ...................................................................................................................................... 51-56 complete articles can be found at https://mev.lipi.go.id https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 12, issue 1, 2021 abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. pudji irasari a, ketut wirtayasa a, b, puji widiyanto a, muhammad fathul hikmawan a, muhammad kasim a, c (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b department of electrical engineering, national taiwan university of science and technology, taiwan; c school of electrical engineering and telecommunications, university of new south wales, australia) characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 1-9, 9 ill, 2 tab, 25 ref. permanent magnet motors (pmms) are widely used in electric vehicles because of their benefits. based on the permanent magnet topologies on the rotor, pmms are classified into three types: surface mounted pmm, inset pmm, and interior pmm. this paper discusses a comparison of the characteristics of interior and inset types of pmms for electric vehicle applications. the study aims to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. simulations were carried out analytically and numerically using the femm 4.2 software. the simulation results at the base speed show that the interior pmm generates a higher torque but with a lower rotation, namely 56.47 nm and 3162 rpm, respectively, while the inset pmm produces higher rotation 4200 rpm but lower output torque of 46.01 nm. however, with a higher saliency ratio, the interior pmm produces higher maximum torque and speed at both constant torque and field weakening regions than the pmm inset, which is 92.87 nm and 6310 rpm, consecutively. in terms of cogging torque, the interior pmm raises it slightly higher (2.90 nm) than the inset pmm (1.93 nm). the results conclude that, in general, the interior pmm shows better performance in all studied regions and is preferable for electric vehicle applications. (author) keywords: permanent magnet motor; interior pmm; inset pmm; torque-speed characteristic; cogging torque. ahmad fudholi a, b, mariyam fazleena musthafa c, goh li jin a, rudi darussalam b, ahmad rajani b, andri setiawan b, anwar b, mohammad hossein yazdi d, hazim moria e, mohd yusof othman a, mohd hafidz ruslan a, kamaruzzaman sopian a (a solar energy research institute, universiti kebangsaan malaysia, malaysia; b research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), indonesia; c department of energy, ministry of environment, republic of maldives; d dept. of electric power generation stations, network and supply systems, institute of engineering and technology, south ural state university, russian federation; e department of mechanical engineering technology, yanbu industrial college, kingdom of saudi arabia) experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 10-17, 9 ill, 4 tab, 22 ref. solar energy is a renewable energy that can produce heat via a thermal system and generate electricity via a photovoltaic (pv) module. a photovoltaic-thermal (pvt) collector is a system that has a pv module combined with a thermal collector system. the pvt collector is a popular technology for harvesting solar energy. a pvt collector can generate both electrical and thermal energies simultaneously. the study aims to validate the pv and outlet temperature for various mass flow rates and solar radiation. to develop a predictive model, a steady-state energy analysis of a pvt air collector was performed. an energy balance equation was solved using the matrix inversion method. the theoretical model was developed and validated against the experimental results, which have a similar trend and are consistent with the experimental results. on the other hand, the validated model was used to study the performances of pvt air collectors using exergy analysis for the mass flow rate ranging from 0.007 kg/s to 0.07 kg/s and solar radiation ranging from 385 w/m2 to 820 w/m2. the result from the mathematical model was found to be consistent with the experimental data with an accuracy of about 95 %. the average pvt exergy efficiency was found to be 12.7 % and 12.0 % for the theoretical and experimental studies, respectively. (author) keywords: mathematical model; thermal efficiency; electrical efficiency; second law efficiency. niam tamami, bambang sumantri, prima kristalina (electrical engineering department, politeknik elektronika negeri surabaya, indonesia) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv local positioning system for autonomous vertical take-off and landing using ultra-wide band measurement ranging system journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no.1, p. 18-27, 18 ill, 0 tab, 25 ref. an autonomous vertical take-off and landing (vtol) must be supported with an accurate positioning system, especially for autonomous take-off, landing, and other tasks in small area. this paper presents a novel method of small local outdoor positioning system for localizing the area of dropping and landing of autonomous vtol by utilizing the low-cost precision ultra-wide band (uwb) ranging system. we compared symmetrical single sided-two way ranging (sss-twr), symmetrical double sided-two way ranging (sds-twr), and asymmetrical double sided-two way ranging (ads-twr) methods to get precision ranging measurement on uwb radio module. ads-twr was superior to others by resulting in minimum distance error. the ads-twr average error was 1.38 % (35.88 cm), sdstwr average error was 1.83 % (47.58 cm), and sss-twr average error was 2.73 % (70.98 cm). furthermore, the trilateration method was utilized to obtain the local position of the autonomous vtol. the trilateration method successfully implemented autonomous vtol quadcopter positioning in a small local outdoor area (20 m x 30 m). autonomous vtol has been able to drop seven payloads in seven areas (2 m x 2 m) and landed in the home position (3 m x 3 m) successfully. (author) keywords: autonomous vtol; uwb local positioning system; trilateration. jumrianto a, royan b (a system and information technology department, ivet university, indonesia; b electromedical engineering department, muhammadiyah university purwokerto, indonesia) proteus isis simulation for power factor calculation using zero crossing detector journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 28-37, 34 ill, 1 tab, 21 ref. one of the important parameters for electrical systems is the power factor (cos phi), which is the ratio of the real power (watt) to the apparent power (volt ampere). the best cos phi value is between 0.85 to 1. a resistive load causes the voltage and current in equal phase angle, while the inductive load causes the current to lag behind the voltage. on the other hand, the capacitive load causes the current to precede the voltage (leading). a simulation to determine the power factor of an electrical network can be done with proteus isis software by creating a phase detection circuit. automatic control can be done by a microcontroller. this simulation circuit can be used as power factor correction, a trigger angle on scr trigger for dc motor speed control, for rocket launch angle adjuster, to measure the angle of inclination, and other uses relating to angle adjustments. (author) keywords: power factor; cos phi; zero-crossing. endro junianto, jooned hendrarsakti (a research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia; b faculty of mechanical and aerospace engineering, institut teknologi bandung, indonesia) a review of single-phase pressure drop characteristics microchannels with bends journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 38-44, 1 ill, 1 tab, 62 ref. microfluidic use in various innovative research, many fields aimed at developing an application device related to handling fluid flows in miniature scale systems. on the other hand, on the use of micro-devices for fluid flow the existence of bends cannot be avoided. this research aims to make a comprehensive study of fluid flow characteristics through a microchannel with several possible bends. this study was conducted by comparing reynolds number versus pressure drop in a serpentine microchannel to gain bends loss coefficient. the result showed that the fluid flow with re < 100 did not affect the pressure drop, but on the reynolds number above that, the pressure drop was increased along with the appears of vortices in the outer and inner walls around the channel bends which causes an increase in an additional pressure drop. the other finding shows that the reduction in diameter bend tube can increase the pressure drop. (author) keywords: pressure drop; bend loss coefficient; singlephase; microchannel bends. nofriyani a, robeth viktoria manurung b, aminuddin debataraja c, indra dwisaputra a (a electrical engineering department, politeknik manufaktur negeri bangka belitung, indonesia; b research center for electronics and telecommunications, indonesian institute of sciences, indonesia; c electrical engineering department, politeknik negeri jakarta, indonesia) phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 45-50, 7 ill, 2 tab, 15 ref. this study describes the development of chemical sensors to detect polypyrrole (ppy) based phosphate sensors in doped di-ammonium hydrogen phosphate (dap) with thick film technology (tft). manufacturing screen-printed carbon electrode (spce) with thick film uses alumina substrate provided a more portable, miniature, inexpensive, and reduced use of samples and reagents. polymer polypyrrole and di-ammonium hydrogen phosphate as sensitive membranes are electrodeposition on carbon electrodes. characterization has been conducted to see the electrode morphology in scanning electron microscopy (sem) test, which showed that sensitive material particles were distributed evenly on the surface of the sample and spherical. the energy dispersive spectroscopy (eds) experiment results showed the atomic composition respectively carbon 86.95 %, nitrogen 6.94 %, oxygen 5.9 %, and phosphate 0.21 %, which were exposed to the electrode. the performance test of electrodes with a phosphate standard solution has proceeded at a concentration between 5 to 100 mg/l, which is measured using the galvanostatic method. the voltage range was from 0.252 to 0.957 v with r2 at approximately 90.265 %. the results of sensor performance were concluded that the electrode was able to detect phosphate ions. (author) keywords: carbon electrode; electropolimerization; phosphate; polymer polypyrrole; thick film. nurul shahirah rukman a, ahmad fudholi a, b, putri adia utari c, cheku nurul aisyah a, andri joko purwanto b, rakhmad indra pramana b, erie martides b, ant. ardath kristi b, nilofar asim a, m. h. yazdi d, hazim moria e, husam abdulrasool hasan f, zeki ahmed darwish g (a solar energy research institute, universiti kebangsaan malaysia, malaysia; b research centre for electrical power and journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 v mechatronics, indonesian institute of sciences (lipi), indonesia; c centre for deep sea research, indonesian institute of sciences (lipi), indonesia; d department of electric power generation stations, network and supply systems, institute of engineering and technology, south ural state university, russian federation; e department of mechanical engineering technology, yanbu industrial college, kingdom of saudi arabia; f department of air conditioning and refrigeration engineering, al esra'a university college, iraq; g ministry of education, united arab emirates) bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 1, p. 51-56, 4 ill, 4 tab, 21 ref. a photovoltaic (pv) system integrated with a bi-fluid cooling mechanism, which is known as photovoltaic thermal (pvt) system, was investigated. the electrical characteristics of flexible solar panel were evaluated for pv and pv with bi-fluid (air and water) cooling system. the integration of monocrystalline flexible solar panel into both systems was tested under a fixed solar radiation of 800 w/m2. a total of 0.04–0.10 kg/s of air flow was utilized in pv with cooling system with a fixed water mass flow rate of 0.025 kg/s. the efficiencies of flexible panel for pv and pv with cooling system were explored. for pv with bi-fluid flow, the highest obtained efficiency of module was 15.95 % when 0.08 kg/s of air and 0.025 kg/s of water were allowed to flow through the cooling system. compared with pv without cooling mechanism, the highest efficiency of module was 13.35 % under same solar radiation. current– voltage and power graphs were also plotted to present the electrical characteristics (current, voltage, and power) generated by both systems. (author) keywords: pv efficiency; pv current; pv voltage; pv power; i–v–p curves. foreword from editor-in-chief list of contents mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.104-109 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia an alternative design and implementation of a solid state on-load tap changer benjamin kommey a, *, elvis tamakloe b, gideon adom-bamfi b, daniel opoku b a kwame nkrumah university of science and technology pmb knustcoe, kumasi, ghana b kwame nkrumah university of science and technology pmb knustee, kumasi, ghana received 5 september 2021; accepted 19 november 2021; published online 31 december 2021 abstract power quality and reliability are of great importance in the modern world, whether it be the power generated by the power utilities or the power consumed by the customer respectively. they need these supplies to be at its optimum value so that the cost is effective, and the safety of devices assured otherwise problems such as overvoltage, under-voltage, and voltage sags caused by disturbances in the power supply could be disastrous. on-load tap changers (oltc) have therefore been used since the inception of electrical engineering. the main function of the oltc is to change the turns of the transformer winding so that the voltage variations are limited without interrupting the secondary current. the major idea is that the electronic switches and other smart systems provide more controllability during the tap changing process, unlike mechanical switches. this paper presents an alternative design and implementation of a low-cost solid-state oltc and employs a control strategy that is microcontroller-based, ensuring the desired flexibility and controllability required in programming the control algorithms. it eliminates the limitations of both mechanical and hybrid oltcs (arcing, slow response time, losses) and is userfriendly (provides an effective communication medium). voltage regulation is achieved by varying the turns of the transformer winding whiles it is energized, supplying load current and with the tap selection carried out on the primary side. therefore, this approach provides a less expensive system but ensures the efficiency and reliability of voltage regulation. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: on-load tap changer; solid-state switch; potential transformer winding; voltage regulation. i. introduction the role of the power utility is not just limited to providing power supply to the customer but also to ensuring good quality and reliability with minimum disruptions in terms of overvoltage, under-voltage, imbalance, noise, and harmonics [1]. these disturbances are undesirable to most industrial and commercial end-users since they have dire economic implications. voltage regulators, capacitors, and dc stored energy systems amongst others have been employed to rectify these problems. the most popular agent for controlling voltage levels at the distribution and transmission systems is the on-load tap changer transformer. the oltc has therefore been widely used since the introduction of electrical energy [2]. tap changers are generally divided into three categories depending on their method of operation; off circuit tap changer, offload tap changer and on-load tap changer [3]. the latter is preferable as there is no disconnection of the transformer when changing the tap setting, thus the operation of supplying the load demand remains uninterrupted. several on-load tap changing systems exist. among these are mechanical, electronically assisted (hybrid), and fully electronic (solid-state) types. the mechanical and electronically assisted types have considerable drawbacks such as arcing, high maintenance, service cost, and slow response time [4]. hence, system reliability is reduced. however, to eliminate these shortcomings, alternative configurations have been introduced which improve the reliability of the system. to date, the proposed constructions have been able to eliminate arc formation using a tap changer where quick operation is desirable. in such a case, the fully electronic (solid-state) tap changer provides the flexibility, controllability, and reliability desired. * corresponding author. tel: +233-5077-03286 e-mail address: bkommey.coe@knust.edu.gh https://dx.doi.org/10.14203/j.mev.2021.v12.104-109 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.104-109 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.104-109&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ b. kommey et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 105 on-load tap changing involves techniques to sense voltage variations and relay this information to an appropriate device for decisions to be taken. the essential nature of the information obtained from this activity has prompted a few studies aimed at developing systems for solid-state on-load tap changing with a handful of prototypes developed. some of these solid states on-load tap changing systems have been developed for use in medium voltage (mv) systems, [5][6]. similarly, in [7][8], solid state oltcs are used to mitigate mv system losses. in [9][10], also employ solid state devices in low voltage (lv) distribution systems for on-load tap changing. in [11][12], a microcontroller is utilized for control operations. oltcs lessen voltage sags in lv systems with power semiconductor devices [13][14]. a. k. gamit showcases a design that maintains the desired load voltage irrespective of input voltage variations [15]. this system has thyristor switched taps on the high voltage (hv) side of the transformer and the load on the low voltage (lv) side. load voltage variations are sensed by the microcontroller and the value compared with a reference. this gives the command to trigger the appropriate antiparallel thyristor for the needed tap selection. rao et al. and thakare et al. present a system that regulates voltage using static oltc with sequential controllers [16][17]. this model has gto switched taps on the primary side and a load connected to the secondary side of a transformer. the load voltage was measured, compared with the pre-set value and an error value obtained. error values found outside the dead band gave a lower or higher correction after a pre-determined delay else no operative action was taken. this process continued until the load voltage was within the inner dead band. the delay in tap selection as a result of this process makes it less reliable. a work conducted by [18] employed the use of thyristors for tap changing. the thyristors tap changer system used two antiparallel thyristors for each tap in a single phase operation. voltage selection was achieved when one group of antiparallel thyristors were turned on and the others off. transitioning from one tap to the other downwards was problematic as a short circuit could occur and damage the system in case of a wrong switching sequence which renders the system inefficient. additionally, the thyristor/gto model which resolved the switching problem needed extra circuitry which resulted in high costs. kavad et al. and pota et al. model offer a system that has a microcontroller that controls the tap selection on the secondary side of the transformer based on the transformer output voltage [19][20]. the tap changing on the secondary side of the transformer leaves the system vulnerable to arcing since tap selection at the secondary side produces high current resulting in sparks which slightly increases cost [21][22]. ii. materials and methods a. proposed system design and architecture the presented solid state on-load tap changer consists of three primary and two secondary units as represented in figure 1. these are the transformer unit (tu), switching unit (su), the microcontroller system communication unit (mscu), the display unit (du) and the signal sensing, conversion and rectification unit (sscru). the su which employs solid state static switches were connected to the control unit of the microcontroller and to the taps on the primary side of the transformer as illustrated. potential figure 1. block diagram of proposed system architecture b. kommey et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 106 transformers and rectifiers were used as sensors to step down voltages from the input and output of the main transformer which were fed to the adc of the microcontroller simultaneously. the microcontroller is responsible for converting the analog signals into digital values for processing. the du which was interfaced with the microcontroller projected numerically the input and load voltages as well as the voltage drops. the su, adc, lcd and the microcontroller were powered by an independent or auxiliary power supply. 1) the transformer unit (tu) the transformer operates on the law of electromagnetic induction (emi). the emi is defined as the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field. the conductors used in transformer cores are wound several times. several connections brought outside from any points between the terminals of the transformer winding with appropriate distancing were transformer tapings. these taps are principally used for voltage control mechanisms and were located on either side of the transformer. based on the transformer emf equation given by. 2 2 1 1 e n k e n = = (1) where e2 and e1 are the secondary and primary voltages, n2 and n1 the secondary and primary turns respectively and k the turns ratio. from equation (1), it is observed that varying the number of turns affects the desired voltage. therefore, to maintain a constant secondary voltage irrespective of the primary voltage, the primary turns were varied to change the turns ratio. this was the tap-changing concept. the knust laboratory’s single-phase transformer with five taps was used as the tu. 2) the switching unit (su) the su uses static solid-state power switches. the choice of switch, working principles, and position on the transformer were factors considered in the design process to achieve efficiency at a minimal cost. there are several static switches employed in ac switching. however, the choice of switch used in the implementation of this project was a triac with a zero-crossing optically isolator or triac driver. the factors that accounted for the choice were the cost, response time, forward voltage drop, losses, the durability of the switch, and the operation voltage of the transformer. the triacs were attached to heat sinks or dissipating brackets to ensure safety when driving the load. the triac driver or optoisolator employed in this system adds a desirable feature of isolation and protection. it interfaces between the microcontroller and triacs to control resistive and inductive loads in ac operation. the pictorial and circuit view of the triac driver or coupler is shown in figure 2. as depicted in figure 2, the triac driver houses an led, optically triggered triac, zero-crossing detector, and a snubber capacitor. a high signal received at a pin glows the led which then triggers the internal triac. the internal triac subsequently receives a gate pulse and connects it to the 240 v end. the zerocrossing provided was primarily to drive resistive loads to ensure minimal switching losses and interferences injected into the supply. the snubber circuit having the resistor (rs) and capacitor (cs) was attached to suppress reverse voltage and control the rate of rising at the turn-off to prevent 𝑑𝑑/𝑑𝑑 retriggering when operating inductive loads. the additional benefit was to reduce radiated noise. current flows through the snubber circuit in the event of a sudden voltage spike 𝑑𝑑/𝑑𝑑. the snubber capacitor cs suppresses 𝑑𝑑/𝑑𝑑 while rs prevents device failure due to discharge current from cs when the triac switches on. a 40 ω maximum resistance and 0.01μf cs were generally considered for 100 v ac power. the charging time (t) of the snubber capacitor is given by the expression [23]: ( )s l st c r r= ´ + (2) where rl is the load resistance. 3) microcontroller system communication unit (mscu) the mscu uses a microcontroller interfaced with an lcd to ensure quality and effective communication. the microcontroller was used as the logical central process control unit to process the input signals and produce a suitable output signal according to the program loaded onto it. it has adc’s which are used for converting rectified analog input and output voltages. these voltages are received as high signals by the microcontroller through its adc pins where they are converted to digital values. based on the program loaded on the microcontroller, decisions are made as to which tap must be selected on the transformer to ensure constant load voltage supply. since the su was directly connected to the high voltage side of the transformer [24], we can protect the microcontroller from exposure to high voltages with triac drivers or opto-isolator [25]. the lcd which is essentially the output device was used to showcase the decisions made by the microcontroller in text and numerical format. it shows the input and output voltages recorded, the tap selected, and the system’s voltage drops. this was needed to provide easy data collection. accurate data transmission to the display is ensured due to the wired connection employed in the system communicating with the microcontroller. figure 2. pictorial and circuit view of the triac driver or optoisolator [23] b. kommey et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 107 b. circuit illustration and flow chart the presented solid-state on-load tap changer components in figure 1 were illustrated in circuit form using proteus professional design and simulation tool. represented in the circuit in figure 3 are the transformer unit (tu), control unit (cu), switching unit (su), display unit (du) and the auxiliary power supply. the transformer unit (tr1) that was used for the simulation had only two taps whose terminals were connected to the triacs. this subsequently reveals the number of triacs (u3, u4) and triac drivers or opto-isolators (u1, u2) that were employed in the switching process. the transformers (tr2, tr3) were involved to step down the input and output alternating current (ac) voltages for the microcontroller action. bridge rectifiers (br1, br2) and capacitors (c1, c2) were used to convert ac to dc and to smoothen the dc respectively. the auxiliary power supply source (b1) provides the dc needed to power the microcontroller and display. the microcontroller (sim1) receives the analog input and load voltages through the analog pins, convert the values into digital forms using the adc and produces a suitable output signal based on the loaded program. a pulse is then authorized to the selected triac through the triac drivers for appropriate tap selection. in figure 4 is a view of the flow chart showing the schemes of operation of the solid-state on-load tap changer. it begins with the initialization of the program as well as the display. any voltage sampled between 15-20 v results in the selection of tap 1 to ensure a constant output voltage else the microcontroller continues to sample voltages between 21-39 v, 40-57 v, and 58-65 v where other corresponding tap may be selected. this cycle continues until an appropriate tap is selected. sampled voltages above 65 v result in a break to this program cycle. iii. results and discussions a prototype of the single-phase solid state onload tap changer comprising of the transformer, switching, microcontroller, and display unit was set up in the knust laboratory. the prototype was subjected to testing in a laboratory environment to achieve precise simulation of the real-life setting. figure 5 shows the prototype test setup. the primary of the transformer was connected to a 240 v rms input voltage and with the aid of a variac, various voltage variations were achieved. the triacs connected to the corresponding taps were triggered by a high signal from the microcontroller to select a particular tap based on the program or algorithm loaded under different voltage situations. figure 3. circuit diagram with all components b. kommey et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 108 the circuit was tested with a 2 kva power transformer having four taps; taps 1, 2, 3, and 4. four tests were run on the circuit to determine proof of concept and performance. in these tests, the input and output voltages of the power transformer were manually measured with a voltmeter and compared with the displayed voltages from the microcontroller. a nominal voltage of 5 v with a tolerance of ±1.5 v was expected to drive the motor load connected across the secondary side of the transformer. at this condition tap 1 was active or on. the results of the tests are summarized in table 1. the prototype was tested for reliability by measuring the output or load voltage of the transformer when the input voltage was increased steadily. from the table, as the input voltage increased above the nominal, the microcontroller generated a pulse which increased the tap setting by one (changing from tap 1 to tap 2) to maintain the load voltage at nominal value. the microcontroller continued to monitor the input voltage and once it fell within the desired range, the appropriate tap was selected, and the cycle continued to loop. the microcontroller managed to maintain the load at its nominal voltage within its specified value of 5±1.5 v and it was shown to be reliable. figure 6 and figure 7 show pictures of the oltc prototype setup. figure 5. test setup of prototype figure 6. a view of the setup showing tap 1 selected on lcd display with an led glow indicator figure 7. another view of the setup indicating tap 2 selected with a corresponding led glow figure 4. interaction of forces in the apf table 1. input voltages with corresponding selected taps and nominal load voltage values condition input voltage output voltage tap number nominal 15 v – 20 v 5 v tap 1 21 v – 39 v 5 v tap 2 40 v – 57 v 5 v tap 3 58 v – 65 v 5 v tap 4 b. kommey et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 104-109 109 an additional system test was conducted which involved higher voltage ranges above 100 v. after the test, two triacs which controlled taps 3 and 4 were damaged. this was attributed to protection related issues. iv. conclusion in this paper, we have proposed and tested a system for on-load tap changing on single phase power transformers. based on theoretical and empirical results, the system maintained a nominal load voltage despite input voltage variations. this proves that the solid-state on-load tap changer differentiates between transformer taps. therefore, this system is a viable option for on-load tap changing. compared to other on-load tap changing systems, it is more effective, accurate, and costeffective. the control and switching system employed in this system eliminates arcing, contact wear since there are no movable parts, reduces maintenance cost, improves switching time, system safety, and stability. the designed system was highly practical and adaptable for lv installations. it can be used to maintain voltage levels in an electrical system given the needed system protection. acknowledgment we thank the faculty of electrical and computer engineering, college of engineering, knust for allowing us to use their laboratories for the experiments. declarations author contribution all authors contributed equally as the main contributor to this study. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no known conflict of financial interest or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] s. m. bashi, “microcontroller-based fast on-load semiconductor tap changer for small power transformer,” journal of applied sciences. 5(6): pp. 999-1003, 2005. [2] p. okanik, b. kurth and j. h. harlow, "an update on the paralleling of oltc power transformers," ieee transmission and distribution conference, vol. 2, pp. 871-875. 1999. [3] c.r. bayliss, transmission and distribution: electrical engineering, 2nd ed. newnes, 1999. [4] r. shuttleworth, a. j. power, x. tian, h. jiang and b. a. t. al zahaei, "a novel thyristor-assisted tap changer scheme," 14th international conference and exhibition on electricity distribution. part 1. contributions (iee conf. publ. no. 438), pp. 28/1-28/5 vol.1, 1997. [5] hao jiang, r. shuttleworth, b. a. t. al zahawi, x. tian and a. power," fast response gto assisted novel tap changer," ieee transactions on power delivery, vol. 16, no. 1, pp. 111-115, jan. 2001. [6] g. h. cooke and k. t. williams, “new thyristor assisted diverter switch for on-load transformer tap changers.” iee proceedings-b, 139: 507-511, 1992. [7] r. fourie and h. du t. mouton, “development of a mv igbt based solid-state tap changer.” ieee, africon, 2009. [8] r. sangeerthana and s. priyadharsini, “controlling of power transformer tap positions using facts devices.” perspective in communication,” embedded-systems and signal processing international journal, vol. 4, issue 7, 2020. [9] d. nadeem, haroon-ur-rashid and m. saeed, "fully electronic tap changer control," 2013 ieee conference on clean energy and technology (ceat), 2013, pp. 114-117. [10] t. yuvaraja and s. vigneshwaran, “voltage regulation by solid state tap change mechanism for distributing transformer,” international journal of engineering research and technology, vol.4, issue 02, 2015. [11] v. s. kale, h. k. chaure, and p. j. pawar, “on load tap changer of transformer using microcontroller.” international journal for scientific research and development, vol.6, issue 01, 2018. [12] h. r. sawake, b. v. sande, v. a. ekkaldevi, s. r. argade, and n. p. zinjad, “power electronic based on-load tap changer,” international journal of research in engineering, science and management, vol.1. issue 12, 2018. [13] a. ahmed, n. ullah, and m. idrees, “design and simulation of imporved on load tap changer to mitigate voltage sag/swell,” international journal of power systems, vol. 5, 2020. [14] p. p. adasur and d. g. chougule, “a review of power transformer tap switching using semiconductor devices,” international journal of research publications in engineering and technology, vol. 2, issue7, 2016. [15] a. k. gamit. “design of solid-state on-load tap changer for transformer using microcontroller,” international journal of science and research, vol.7, issue 11, 2018. [16] rao, s. v. m. bhuvanaika, b. subramanyeswar, "fine voltage control using oltc by static tap change mechanism," international journal of advanced computer research; bhopal vol. 2, iss. 4, (dec 2012): 328-333. [17] p. b. thakare, and m. a. mechkul, “electronics solid state voltage regulating relay for on load tap changer distribution transformer for automatic voltage regulation,” international journal of modern trends in engineering and research, vol.4, issue 06, 2017. [18] m. h. taha, “on load single-phase solid-state tap changer,” international journal of engineering technologies, vol.2, no.2, 2016. [19] a. b. kavad, s. n. khandhar, b. a. sodha, and y.d. tita, “solid state tap changer for utility transformer,” international journal for scientific research and development, vol.5, issue 02, 2017. [20] i. k. pota, s. bhatti, i. rathod, p. sudiya, and s. rohit, “microcontroller based tap changer for power transformer,” journal of emerging technologies and innovative research, vol.5, issue 04, 2018. [21] m. a. sanjay, t. s. raosaheb, n. s. ravindra, v. r. kirandas, “solid state on load tap changer for transformer,” resincap journal of science and engineering, vol.5, issue 04, 2021. [22] n. nagalakshmi and t. thivagar, “automatic tap-changer with triac switch for constant voltage and current measurements,” international journal of recent technology and engineering, vol. 9, issue 2, 2020. [23] “triac couplers basic properties and application design,” toshiba electronic devices and storage corporation, rev.1.0 , 2018. [24] v. t. chacko, m. p. noufal, n. p. mohan, s. b. vinod and k. a. eldhose, "solid state on load tap changer for transformer using arduino," international research journal of engineering and technology, vol. 4, no. 4, p. 4, 2017. [25] v. s. bugade, e. mishra, m. h. jayebhaye, h. joshi, a. patil, and b. kale, “automatic voltage control of load using on load tap changer,” international journal for research in applied science and engineering technology, vol. 6, issue 03, 2018. https://mev.lipi.go.id/ https://dx.doi.org/10.3923/jas.2005.999.1003 https://dx.doi.org/10.3923/jas.2005.999.1003 https://dx.doi.org/10.3923/jas.2005.999.1003 https://dx.doi.org/10.1109/tdc.1999.756164 https://dx.doi.org/10.1109/tdc.1999.756164 https://dx.doi.org/10.1109/tdc.1999.756164 https://www.elsevier.com/books/transmission-and-distribution-electrical-engineering/bayliss/978-0-7506-4059-6 https://www.elsevier.com/books/transmission-and-distribution-electrical-engineering/bayliss/978-0-7506-4059-6 https://doi.org/10.1049/cp:19970467 https://doi.org/10.1049/cp:19970467 https://doi.org/10.1049/cp:19970467 https://doi.org/10.1049/cp:19970467 https://doi.org/10.1049/cp:19970467 https://doi.org/10.1109/61.905608 https://doi.org/10.1109/61.905608 https://doi.org/10.1109/61.905608 https://doi.org/10.1109/61.905608 https://doi.org/10.1049/ip-b.1992.0062 https://doi.org/10.1049/ip-b.1992.0062 https://doi.org/10.1049/ip-b.1992.0062 https://doi.org/10.1109/afrcon.2009.5308128 https://doi.org/10.1109/afrcon.2009.5308128 https://doi.org/10.5281/zenodo.4249184 https://doi.org/10.5281/zenodo.4249184 https://doi.org/10.5281/zenodo.4249184 https://doi.org/10.5281/zenodo.4249184 https://doi.org/10.1109/ceat.2013.6775610 https://doi.org/10.1109/ceat.2013.6775610 https://doi.org/10.1109/ceat.2013.6775610 https://www.semanticscholar.org/paper/voltage-regulation-by-solid-state-tap-change-for-yuvaraja-vigneshwaran/72b73147d98d8c75746dc6093a75d4321b9c406c https://www.semanticscholar.org/paper/voltage-regulation-by-solid-state-tap-change-for-yuvaraja-vigneshwaran/72b73147d98d8c75746dc6093a75d4321b9c406c https://www.semanticscholar.org/paper/voltage-regulation-by-solid-state-tap-change-for-yuvaraja-vigneshwaran/72b73147d98d8c75746dc6093a75d4321b9c406c https://www.semanticscholar.org/paper/voltage-regulation-by-solid-state-tap-change-for-yuvaraja-vigneshwaran/72b73147d98d8c75746dc6093a75d4321b9c406c http://www.ijsrd.com/articles/ijsrdv6i10650.pdf http://www.ijsrd.com/articles/ijsrdv6i10650.pdf http://www.ijsrd.com/articles/ijsrdv6i10650.pdf https://www.ijresm.com/vol_1_2018/vol1_iss12_december18/ijresm_v1_i12_96.pdf https://www.ijresm.com/vol_1_2018/vol1_iss12_december18/ijresm_v1_i12_96.pdf https://www.ijresm.com/vol_1_2018/vol1_iss12_december18/ijresm_v1_i12_96.pdf https://www.ijresm.com/vol_1_2018/vol1_iss12_december18/ijresm_v1_i12_96.pdf https://www.iaras.org/iaras/filedownloads/ijps/2020/010-0011(2020).pdf https://www.iaras.org/iaras/filedownloads/ijps/2020/010-0011(2020).pdf https://www.iaras.org/iaras/filedownloads/ijps/2020/010-0011(2020).pdf https://repo.journalnx.com/index.php/nx/article/view/1025 https://repo.journalnx.com/index.php/nx/article/view/1025 https://repo.journalnx.com/index.php/nx/article/view/1025 https://repo.journalnx.com/index.php/nx/article/view/1025 https://www.ijsr.net/get_abstract.php?paper_id=art20192853 https://www.ijsr.net/get_abstract.php?paper_id=art20192853 https://www.ijsr.net/get_abstract.php?paper_id=art20192853 https://www.proquest.com/docview/1288633473 https://www.proquest.com/docview/1288633473 https://www.proquest.com/docview/1288633473 https://www.proquest.com/docview/1288633473 https://doi.org/10.21884/ijmter.2017.4187.c3jjw https://doi.org/10.21884/ijmter.2017.4187.c3jjw https://doi.org/10.21884/ijmter.2017.4187.c3jjw https://doi.org/10.21884/ijmter.2017.4187.c3jjw https://doi.org/10.21884/ijmter.2017.4187.c3jjw https://doi.org/10.19072/ijet.36819 https://doi.org/10.19072/ijet.36819 https://doi.org/10.19072/ijet.36819 http://www.ijsrd.com/articles/ijsrdv5i20419.pdf http://www.ijsrd.com/articles/ijsrdv5i20419.pdf http://www.ijsrd.com/articles/ijsrdv5i20419.pdf https://www.jetir.org/papers/jetir1804143.pdf https://www.jetir.org/papers/jetir1804143.pdf https://www.jetir.org/papers/jetir1804143.pdf https://www.jetir.org/papers/jetir1804143.pdf https://www.rijse.com/wp-content/uploads/2021/06/solid-state-on-load-tap-changer-for-transformer.pdf https://www.rijse.com/wp-content/uploads/2021/06/solid-state-on-load-tap-changer-for-transformer.pdf https://www.rijse.com/wp-content/uploads/2021/06/solid-state-on-load-tap-changer-for-transformer.pdf https://doi.org/10.35940/ijrte.b3276.079220 https://doi.org/10.35940/ijrte.b3276.079220 https://doi.org/10.35940/ijrte.b3276.079220 https://doi.org/10.35940/ijrte.b3276.079220 https://toshiba.semicon-storage.com/info/docget.jsp?did=63136 https://toshiba.semicon-storage.com/info/docget.jsp?did=63136 https://toshiba.semicon-storage.com/info/docget.jsp?did=63136 https://www.irjet.net/archives/v4/i4/irjet-v4i4307.pdf https://www.irjet.net/archives/v4/i4/irjet-v4i4307.pdf https://www.irjet.net/archives/v4/i4/irjet-v4i4307.pdf https://www.irjet.net/archives/v4/i4/irjet-v4i4307.pdf http://dx.doi.org/10.22214/ijraset.2018.3681 http://dx.doi.org/10.22214/ijraset.2018.3681 http://dx.doi.org/10.22214/ijraset.2018.3681 http://dx.doi.org/10.22214/ijraset.2018.3681 introduction ii. materials and methods a. proposed system design and architecture b. circuit illustration and flow chart iii. results and discussions iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.79-87 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: r.v. febriyana et al., “two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 79-87, july 2022. two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises royke vincentius febriyana a, *, ramadhan s. pernyata a, dita andansari b a product design department, samarinda state polytechnic (politeknik negeri samarinda) jalan dr. ciptomangunkusumo, kampus gn. lipan, samarinda seberang, samarinda, 75131, indonesia b industrial design, razak faculty of technology and informatics, universiti teknologi malaysia level 8, menara razak, jalan sultan yahya petra, kuala lumpur, 54100, malaysia received 5 april 2021; revised 13 december 2021; accepted 15 march 2022; published online 29 july 2022 abstract small and medium-sized enterprises (smes) have a big role in indonesian economic development. the government has set four strategies in an effort to boost indonesian economic development. one of the four strategies mentions the smes, and the other mentions the use of 4.0 technology. working capital has been the main issue need to be considered in the smes. thus, the affordability must be considered in the use of 4.0 technology in smes. one of the 4.0 technologies that are possible to be used in the smes is a three-axis milling machine. one of the limitations of the machine is that it cannot do the back-side machining process. the paper examines the possibility of manual back-side machining on the three-axis milling machine without adding a rotary axis. four methods were conducted by adding two-point markings on the x-axis, two-point markings on the y-axis, four-point markings on the xand y-axis, and four-point markings on the xand y-axis plus a series of offsetting processes. after conducting several qualitative observations and measurements on the mismatched position of the front and the back machining, and also analyzing the problems that emerged during the processes of the four different methods, it is concluded that adding four points markings on the xand y-axis plus doing a series of offsetting processes is the best method to have two-sided manual machining with three-axis computer numerical control (cnc) milling machine. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: computer numerical control (cnc); small and medium-sized enterprises (smes); three-axis; two-sided machining. i. introduction the indonesian government establishes four strategies to boost economic development. two of the four strategies mention small and medium-sized enterprises (smes) and the use of 4.0 technology. the main problem that emerged in smes is working capital. it must be admitted that the smes still have to deal with technical skills and capital resources, but they recognize the benefit of 4.0 technology for their production line [1]. in terms of adopting 4.0 technology, research suggests that smes are concerned about how the investment should be compared with the benefit [2]. one of the 4.0 technology that is possible to be used in smes is a three-axis milling machine [3]. three-axis milling machine is considered to be a 4.0 technology for its advantage in terms of automation, which enables users to have the machine make a prototype based on a digital design created by the user. the advantages provide possibilities to do repeated production in a controlled standard [4]. there is research on building affordable three-axis milling machine that emphasizes the production cost [5][6], easy assembly method [7][8], low-cost computer numerical control (cnc) with specific function [9][10], portability [11], and size [12]. there is also some research about the use of three-axis milling machines for smes [13][14][15]. one of the limitations of the machine is that it cannot do a back-side machining process. the purpose can usually be done with the four-axis milling machine. previous researches try to modify the three-axis milling machine into four-axis [16] and five-axis by adding another axis [17]. adding a rotary axis to a three-axis milling machine has been proven to * corresponding author. tel: +62-817300646 e-mail address: rvincentius@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.79-87 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.79-87 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.79-87&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 80 produce complex products such as gears [16]. a rotary axis needs to be added in the effort, meaning the need for a bigger working table and more investment is required, while the miniaturization of the machine emerged in recent years aims to reduce investment in machines and production costs [18]. a smaller four-axis cnc machine that is able to perform back-side machining is already developed by e. e. wai and s. s. aung [19], but still, the design needs to add a rotary axis. this paper examines the possibility of doing back-side machining on the three-axis milling machine instead of adding a rotary axis and modifying it into a four-axis milling machine. ii. materials and methods the basic principle for doing the two-sided machining process in a four-axis milling machine is to keep the x-, y-, and z-axis on the back-side process at the same position as it is on the front side. the paper will only focus on keeping the xand yaxis in the proper place. the z-axis setting will be performed using the common method used in a three-axis milling machine that does not use a sensor to determine the (0,0,0) point position of the x-, y-, z-axis. this paper offers four methods for the purpose. the experiment is done with the china cnc zone three-axis milling machine. the software used for the research is mach 3 ver. 2.0 and artcam jewelsmith ver 8.1. a piece of 3 mm plywood is then set as a working platform on the working table (figure 1) to allow the process to make marks on the platform. the material used for the experiments is 15 mm pine wood (softwood), measured 90 mm wide with the length varies from 100 to 170 mm. the material was then fastened on the working platform (figure 2). there are two basic machining stages prepared for the experiment: roughing (raster in closed vector) and offset along the curve. the tool used is hard endmill, 3.175 in diameter, 2 flutes, and 20 mm flute length. the tool federate is 3 mm/s, with 40% step over, and 1 mm step down. the 𝑧 = 0 is set on top of the material. each process can be done multiple times for different purposes and other settings will be added for certain specific purposes that need to be done to make each of the four methods give the best results. the four manual two-sided machining methods examined are: • method 1: two-point markings on x-axis • method 2: two-point markings on y-axis • method 3: four-point markings on x-axis plus two-point markings on y-axis • method 4: four-point markings x-axis and yaxis with offset checking a. method 1: two-point markings on x-axis two-point marking is made on a working platform set on top of the working table. the marking is made on each tip of the material side on the x-axis (with y-axis = 0) (figure 3) and the machine path on making marking is shown in figure 4. the markings will keep the x-axis in the same position on the front-side as on back-side machining, and the imaginary lines created by the two marking points will also act as the feature that can keep the y-axis in place. the processes made on each side are described as follows: figure 1. working platform setting figure 2. material setting figure 3. two markings on x-axis r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 81 1) method 1 front side the roughing process is applied to slowly carve the material block into the rough desired shapes. the offset 1 process is applied in order to reach the precise outline of the desired shapes. the offset 2 process is applied to ensure that the shape remains exactly as desired. the x-axis marking process is applied to make two markings on each side of the material and the working platform as references when flipping the material to do the back-side machining (figure 5). 𝑎′ = −𝑎 𝑎 = ± 1 2 material width (1) where 𝑡 is tool diameter, 𝑐 is center zero ((𝑥, 𝑦, 𝑧) = (0,0,0)), 𝑎 is distance from center zero to marking point 1 (on the x-axis), and 𝑎′ is distance from center zero to marking point 2 (on the x-axis). the tool depth in making the markings is approximately the measurement of the material thickness plus 1 mm (figure 6). 𝑇𝑇 = 𝑀𝑇 + 1 mm (2) where 𝑇𝑇 is tool depth/tool final pass and 𝑀𝑇 is material thickness. 2) method 1 back side the material flipped with the y-axis is considered to be the rotary axis (shown in figure 7). the roughing process is applied to slowly carve the material block into the rough desired shapes. the offset 1 process is applied in order to reach the precise outline of the desired shapes. the result will be compared to the same process done on the front side. the offset 2 process is applied to remove the holder of the main shape. b. method 2: two-point markings on y-axis in this method, two-point marking is made on a working platform, on each tip of the material side on the y-axis (with x-axis = 0) (figure 8), by moving the spindle along the y-axis (figure 9). the distance between the 𝑦 = 0 points to the marking point at the top and bottom of the material does not have to be the same since the material is going to be rotated on the y-axis. the imaginary lines created by the two marking points will also act as the feature that can keep the x-axis in place. the processes made on each side are almost the same as the processes on the first method (two-point markings on the x-axis), except for the markings step: figure 5. guidance on making the two markings on x-axis figure 6. tool depth in making the markings front side back side figure 7. flipping material to do back-side machining figure 4. machine path on making markings r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 82 1) method 2 front side roughing, offset 1, offset 2, and the y-axis marking process will be performed on the front side. the y-axis marking is applied to make two markings on each top and bottom side of the material and the working platform (on the y-axis/𝑦 = 0) (figure 10) as the references when flipping the material to do the back-side machining process. the distance of “a” or “a’” in figure 5 is not necessarily the same as the distance of “b” or “b’” in figure 10, as it depends on the size of the products and the materials provided. in method 1, the distance of “a” must be the same as the distance of “a’”, since the two markings are not positioned on the flipping axis (figure 5). the distance of “b” does not have to be the same as “b’” since the flipping axis and the two markings are on the same axis (yaxis) (figure 10). 𝑏′ ≠ 𝑏 (3) where 𝑡 is tool diameter, 𝑐 is center zero ((𝑥, 𝑦, 𝑧) = (0,0,0)), 𝑏 is distance from center zero to marking point 1 (on y-axis), and 𝑏′ is distance from center zero to marking point 2 (on y-axis). 2) method 2 back side the procedures conducted in the back side of method 2 is similar as the procedure conducted in method 1. c. method 3: four-point markings on x-axis plus two-point markings on y-axis in this method, four-point marking is made on a working platform set on top of the working table. the two markings are made on each tip of the material side on the x-axis (with y-axis = 0), and the other two markings are made on each tip of the material side on the y-axis (with x-axis = 0) (figure 11). the distance between the 𝑥 = 0 point and the marking point at the right and left sides of the material is the same, while the distance between the 𝑦 = 0 point and the marking point at the top and the bottom of the material does not have to be the same. the two points on the x-axis and the other two on the y-axis will compensate for each other and keep the xand y-axis at the same place, both on the front and the back side of the material machining processes. the processes on each side are almost the same as the processes on the method 1 (two-point markings on x-axis), except for the markings step. the method combines the markings on the x-axis and y-axis: figure 10. guidance on making the two markings on y-axis figure 8. two markings on y-axis figure 9. machine path on making markings figure 11. four markings on x-axis and y-axis r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 83 1) method 3 front side the procedures conducted in the front side of method 3 is similar as the procedure conducted in method 1 and method 2, except for adding both x and y-axis marking. 2) method 3 back side the procedures conducted in the back side of method 3 is similar as the procedure conducted in method 1 and method 2. d. method 4: four-point markings x-axis and y-axis with offset checking many factors can affect the accuracy of the machining process. the hardness of the material, the tool strength [20], the tool design, and any other potential cutting parameters [21] can affect the accuracy of the machining results. there is a possibility that the tool might bend during the marking-point making or be deformed because of the heat generated when the tool penetrates through some hard materials like hardwoods, acrylic, resin, or steel [22]. tool deflection has become one of the major causes of volumetric errors of produced parts [23]. thus, the marking point position at the first contact between the tool and the material might not be the same as at the bottom of the material. this will generate difficulties in adjusting the marking position on the back-side machining processes. another series of offsetting processes were added to the previous method to ensure the precision of the back-side machining process. two rectangular shapes were added at the top and bottom sides of the main product (figure 12). the rectangular shapes have then been offset at both the front and back sides machining processes (figure 13). if, after the back-side offset process, it is found that there is a gap as a result of the mismatched xand y-axis position, manual adjustment can be made to match the xand y-axis position. 1) method 4 front side roughing is done from the top to the bottom of the material. the top and bottom rectangular shape roughing process is performed to make a hole on the top and bottom of the main object’s rastered area. it is made to ensure that the top and bottom holes are created in specific measurements. the main object offset is applied in order to reach the precise outline of the desired shapes. the xand y-axis marking processes are applied to make two marking points on each side of the material, the working platform (x-axis markings), each outer side of the rectangular holes, and the working platform (y-axis markings), similar to method 3. 2) method 4 back side the first consideration in doing back-side machining is that the xand y-axis have to be already at the same position as it is in the front-side machining. a series of offset checking is performed as additions after setting the marking on the material in its proper place (at the reference/marking points made on the working platform). the back-side machining started with an offset process along the top and bottom rectangular shape. if the offset markings seem mismatched, the zero position ( (𝑥, 𝑦) = (0,0) ) can be adjusted by manually moving the position to the xor y-axis in the machining software (mach 3 ver 2.0) to the position considered to be the correct new zero xor y-axis position. after the position seems correct, the offset process for the main object can be done. if the offset process leaves a mark on the main object indicating a mismatching position, the zero position ((𝑥, 𝑦) = (0,0)) can be readjusted. the process can be done until the offset no longer leaves a mismatched mark on the main object. the roughing process follows the process above. the offset process can be done to see if the position of the main object of the back-side machining is already matched the front. then the object holder can be offset. figure 13. offset checking procedure figure 12. method 4 settings r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 84 iii. results and discussions each methods was performed three times. the results shown by the three runs for each method were then compared by visual traits, measurements, and the significance of the mismatched mark to the finished end products, and problems that emerged along with the processes. the results for method 1 is shown in figure 14a in which the mismatched marks can clearly be seen. the results of method 2 (figure 14b) were similar with method 1. furthermore, the mismatched marks still appear in the experiment made with method 3 (figure 14c). experiments conducted with method 4 shows the best results where the mismatched marks are no longer visible (figure 14d). (a) (b) (c) (d) figure 14. results of each three runs for each method: (a) method 1; (b) method 2; (c) method 3; and (d) method 4 r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 85 the comparative results are tabulated in table 1, table 2, and table 3. the first parameter in measuring if the method gives the best result is by qualitatively observing and comparing the mismatched marks between the front and the backside machining processes results (table 1). all threerun results done with method 1 show that mismatched marks can be clearly seen. the same traits are also shown in all three runs of each method 2 and method 3. in method 4, the mismatched marks are relatively less visible compared to the results of the other three methods. the second parameter to determine if the methods give the best results is by measuring the distance of the mismatched position of the front and back machining processes. the narrower the mismatched position, the better the result is. the results of the measurements are tabulated in tabek 2. in method 1, the average distance of a mismatched position on the x-axis is 0.48 mm, while the y-axis is 0.41 mm. in method 2, the average distance of a mismatched position on the x-axis is 0.42 mm, while the y-axis is 0.45 mm. in method 3, the average distance of a mismatched position on the x-axis is 0.41 mm, while the y-axis is 0.43 mm. in method 4, the average distance of a mismatched position on the x-axis is 0.1 mm, while the y-axis is 0.22 mm. the distance between a mismatched position of the front-side machining processes and the backside machining gives a direct result in the quality of the finished end products. the wider the mismatched distance will result in greater efforts to remove the mark by sanding the product’s side surface. the more the side is sanded, the more the actual size of the product is reduced; thus, the end size will not be relatively similar to the design. this would be a great problem, especially if the design includes wall features along the outer side of the products. the sanding processes could result in a different thickness of the wall. the significance of the effects of the mismatched marks on the finished end products is tabulated in table 3. even though the mismatched marks in all of the results given by all the four methods are removable by the sanding process; since the mismatched marks in methods 1, 2, and 3 are relatively wider compared to method 4, it can be resulted in a width differences if the product design includes wall features along the outer side. it also needs to be considered if the methods have emerging problems along the process. the problems that emerged along the processes can be seen in table 4. method 1 is considered to have fewer problems since the features included in the process are not many. the more features included in the methods, the more problem emerged in the process. method 4 provides more difficulties during the process, but the problems can be overcome by the last process of the method (by manually adjusting (𝑥, 𝑦) = (0,0) and offset checking). but it is worth it since the final results have given the best results, as shown in table 1, table 2, and table 3. table 1. visual traits comparison method 1st run 2nd run 3rd run 1 clearly visible clearly visible clearly visible 2 clearly visible clearly visible clearly visible 3 clearly visible clearly visible clearly visible 4 almost invisible almost invisible slightly visible table 2. measurements comparison on mismatched position method mismatched distance (mm) 1st run 2nd run 3rd run x-axis y-axis x-axis y-axis x-axis y-axis 1 0.46 0.30 0.41 0.39 0.58 0.54 2 0.38 0.37 0.38 0.43 0.49 0.56 3 0.20 0.27 0.57 0.66 0.45 0.35 4 0.07 0.15 0.13 0.21 0.11 0.31 table 3. significance of the mismatched mark to the finished end products method significance of the mismatched mark to the finished end products 1st run 2nd run 3rd run 1 insignificant, removeable with sanding paper, leaving visible thickness differences after sanded insignificant, removeable with sanding paper, leaving visible thickness differences after sanded insignificant, removeable with sanding paper, leaving visible thickness differences after sanded 2 insignificant, removeable with sanding paper insignificant, removeable with sanding paper, leaving visible thickness differences after sanded insignificant, removeable with sanding paper, leaving visible thickness differences after sanded 3 insignificant, removeable with sanding paper insignificant, removeable with sanding paper, leaving visible thickness differences after sanded insignificant, removeable with sanding paper, leaving visible thickness differences after sanded 4 insignificant, almost no further action needed insignificant, almost no further action needed insignificant, removeable with sanding paper r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 86 iv. conclusion all four methods examined are possible to be used for the back-side machining. but method 4, which includes the two-point markings on each xaxis and y-axis with the offset checking method, has given the best results. the method gives the opportunity to check the position of the xand yaxis, whether they are already in the precisely desired positions, which cannot be done with the other three methods. the comparison of the results shown by the four methods reveals that in method 4, the mismatched marks are relatively almost invisible compared to the results of the other three methods. in method 4, the average distance of a mismatched position on the x-axis is 0.1 mm, and on the y-axis is 0.22 mm. the distance is narrower compared to the other three methods. even though the mismatched marks in all of the results given by all the four methods are removable with the sanding process; but since the mismatched marks in method 1, method 2, and method 3 are relatively wider compared to method 4, it can result in width differences if the product design includes wall features along the outer side. method 4 is emerging more difficulties during the process, but it is worth to be done since the final results have given the best results compared to the other three methods. the method can be used for smes with limited capital capabilities since the method can be done manually with the three-axis milling machine and does not require an additional fourth axis. acknowledgment the authors would like to express our deep appreciation to politeknik negeri samarinda for funding, supporting, and assisting the research. declarations author contribution r.v. febriyana: writing original draft, writing review & editing, conceptualization, experimentation, formal analysis, investigation, visualization, supervision. r.s. pernyata: writing original draft, writing review & editing, conceptualization, investigation, validation, photography. d. andansari: data curation, formal analysis, resources, software, visualization. funding statement this research has received funding from politeknik negeri samarinda through the research and development scheme, under decision letter no. 938/pl7/lt/2020 and work order no. 1746/pl7/lt/2020. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] d. ryfors, m. wallin, and t. truve, “swedish manufacturing smes readiness for industry 4.0,” bachelor thesis, sweden: jönköping university, 2019. [2] m. eriksson and o. ekebring, “managing a transformation towards industry 4.0: a study within the bus manufacturing industry,” industrial management degree project, sweden: karlstads universitet, 2020. [3] d. awari, m. bhamare, a. ghanwat, k. jadhav, and j. chahande, “methodology for selecting components for fabricating cnc milling machine for small scale industry,” international journal for scientific research and development (ijsrd), vol. 4(11), pp. 168-171, 2017. [4] s. vaidya, p. ambad, and s. bhosle, “industri 4.0 – a glimpse,”. procedia manufacturing, vol. 20, pp. 233-238, 2018. [5] b. jayachandraiah, o. v. krishna, p. a. khan, and r. a. reddy, “fabrication of low cost 3-axis cnc router,” international journal of engineering science invention (ijesi), vol. 3(6), pp. 1-10, jun. 2014. [6] w. qin, “design and analysis of a small-scale cost-effective cnc milling machine,” thesis, illinois: university of illinois urbana-champaign, 2013. [7] n. sathyakumar, k. p. balaji, r. ganapathi, and s. r. pandian, “a build-your-own three axis cnc pcb milling machine,” in proc. iconamma, 2018, pp. 24404–24413. [8] p. bhasin, p. singh, and s. singh, “design and fabrication of low-cost wood working mini cnc milling machine for students skill development,” international journal of advance research and innovation (ijari), vol. 8(1), pp. 30-33, mar. 2020. [9] p. girhe, s. yenkar, and a. chirde, “arduino based cost effective cnc plotter machine,” international journal of emerging technologies in engineering research (ijeter), vol. 6(2), pp. 6-9, feb. 2018. [10] s. patil and s. s. anasane, “development of 3-axis micro-step resolution desktop cnc stage for machining of mesoand microscale-features,” in advances in simulation, product design and development (aimtdr), springer, 2018, pp. 637652. [11] ernest, h. sutanto, and d. setyanto, “cnc milling portable pm 1035,” international journal of applied engineering research (ijaer), vol. 13(12), pp. 10358-10364, 2018. [12] s. m. ali and h. mohsin, “design and fabrication of 3-axes mini cnc milling machine,” presented at the 1st international conference on sustainable engineering and technology (intcset), baghdad, iraq. 2020. [13] r. ginting, s. hadiyoso, and s. aulia, “implementation 3-axis cnc router for small scale industry,” international journal of applied engineering research (ijaer), vol. 12(17), pp. 65536558, 2017. table 4. problems emerged along the processes method visual traits 1 no significant problem 2 setting the material at the correct markings was found to be a little difficult (in y(+)), for the view is blocked by the spindle 3 setting the material at the correct four markings was found to be more difficult than at two markings. it tends to miss one marking (top y (y(+)) markings) 4 setting the material at the correct four markings was found to be more difficult than at two markings. it tends to miss one marking (top y (y(+)) markings) https://mev.lipi.go.id/ https://www.diva-portal.org/smash/get/diva2:1321698/fulltext01.pdf https://www.diva-portal.org/smash/get/diva2:1321698/fulltext01.pdf https://www.diva-portal.org/smash/get/diva2:1321698/fulltext01.pdf https://www.diva-portal.org/smash/record.jsf?pid=diva2%3a1448492&dswid=-7016 https://www.diva-portal.org/smash/record.jsf?pid=diva2%3a1448492&dswid=-7016 https://www.diva-portal.org/smash/record.jsf?pid=diva2%3a1448492&dswid=-7016 https://www.diva-portal.org/smash/record.jsf?pid=diva2%3a1448492&dswid=-7016 http://www.ijsrd.com/articles/ijsrdv4i110098.pdf http://www.ijsrd.com/articles/ijsrdv4i110098.pdf http://www.ijsrd.com/articles/ijsrdv4i110098.pdf http://www.ijsrd.com/articles/ijsrdv4i110098.pdf http://www.ijsrd.com/articles/ijsrdv4i110098.pdf https://doi.org/10.1016/j.promfg.2018.02.034 https://doi.org/10.1016/j.promfg.2018.02.034 https://www.ijesi.org/papers/vol(3)6/version-1/a036101010.pdf https://www.ijesi.org/papers/vol(3)6/version-1/a036101010.pdf https://www.ijesi.org/papers/vol(3)6/version-1/a036101010.pdf https://www.ijesi.org/papers/vol(3)6/version-1/a036101010.pdf http://hdl.handle.net/2142/44140 http://hdl.handle.net/2142/44140 http://hdl.handle.net/2142/44140 https://doi.org/10.1016/j.matpr.2018.10.236 https://doi.org/10.1016/j.matpr.2018.10.236 https://doi.org/10.1016/j.matpr.2018.10.236 https://ijari.org/assets/papers/8/1/ijari-me-20-03-101.pdf https://ijari.org/assets/papers/8/1/ijari-me-20-03-101.pdf https://ijari.org/assets/papers/8/1/ijari-me-20-03-101.pdf https://ijari.org/assets/papers/8/1/ijari-me-20-03-101.pdf https://www.ijeter.everscience.org/manuscripts/volume-6/issue-2/vol-6-issue-2-m-02.pdf https://www.ijeter.everscience.org/manuscripts/volume-6/issue-2/vol-6-issue-2-m-02.pdf https://www.ijeter.everscience.org/manuscripts/volume-6/issue-2/vol-6-issue-2-m-02.pdf https://www.ijeter.everscience.org/manuscripts/volume-6/issue-2/vol-6-issue-2-m-02.pdf https://doi.org/10.1007/978-981-32-9487-5_52 https://doi.org/10.1007/978-981-32-9487-5_52 https://doi.org/10.1007/978-981-32-9487-5_52 https://doi.org/10.1007/978-981-32-9487-5_52 https://doi.org/10.1007/978-981-32-9487-5_52 https://www.ripublication.com/ijaer18/ijaerv13n12_34.pdf https://www.ripublication.com/ijaer18/ijaerv13n12_34.pdf https://www.ripublication.com/ijaer18/ijaerv13n12_34.pdf https://iopscience.iop.org/article/10.1088/1757-899x/1094/1/012005/pdf https://iopscience.iop.org/article/10.1088/1757-899x/1094/1/012005/pdf https://iopscience.iop.org/article/10.1088/1757-899x/1094/1/012005/pdf https://iopscience.iop.org/article/10.1088/1757-899x/1094/1/012005/pdf https://www.ripublication.com/ijaer17/ijaerv12n17_34.pdf https://www.ripublication.com/ijaer17/ijaerv12n17_34.pdf https://www.ripublication.com/ijaer17/ijaerv12n17_34.pdf https://www.ripublication.com/ijaer17/ijaerv12n17_34.pdf r.v. febriyana et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 79-87 87 [14] a. estiyono, a. kurniawan, and a. d. krisbianto, “prototipe mesin cnc 3 axis sederhana untuk ikm mainan edukasi berbahan kayu,” jurnal desain idea, vol. 17(2), pp. 17-20, oct. 2018. [15] k. bangse, a. wibolo, and i. k. e. h. wiryanta, “design and fabrication of a cnc router machine for wood engraving,” presented at the international conference on applied science and technology on engineering science (icast-es), bali, indonesia, 2019. [16] s. h. suh, w. s. jih, h. d. hong, and d. h. chung, “sculptured surface machining of spiral bevel gears with cnc milling,” international journal of machine tools and manufacture, vol. 41(6), pp. 833-850, may 2001. [17] s. suh and j. lee, "five-axis part machining with three-axis cnc machine and indexing table," asme journal of manufacturing science and engineering, vol. 120(1), pp. 120– 128, feb. 1998. [18] d. a. axinte, s. a. shukor, and a. t. bozdana, “an analysis of the functional capability of an in-house developed miniature 4-axis machine tool,” international journal of machine tools & manufacture, vol. 50(2), pp. 191-203, feb. 2010. [19] e. e. wai and s. s. aung, “design and implementation of 4-axis cnc machine,” international journal of recent innovations in academic research, vol. 3(8), pp. 60-71, aug. 2019. [20] l. n. l. de lacalle, a. lamikiz, j. a. sánchez, and m. a. salgado, “effects of tool deflection in the high-speed milling of inclined surfaces,” international journal of advanced manufacturing technology, vol. 24, pp. 621-631, nov. 2004. [21] s. n. phokobye, i. a. daniyan, i. tlhabadira, l. masu, and l. r. vanstaden, “model design and optimization of carbide milling cutter for milling operation of m200 tool steel,” procedia cirp, vol. 84, pp. 954-959, 2019. [22] s. hu, m. zhang, y. cui, r. xue, and z. yang, “accuracy enhancement with processing error prediction and compensation of a cnc flame cutting machine used in spatial surface operating conditions,” journal of engineering and technological sciences, vol. 49(1), pp. 75-94, apr. 2017. [23] m. soori, b. arezoo, and m. habibi, “accuracy analysis of tool deflection error modelling in prediction of milled surfaces by a virtual machining system,” international journal of computer applications in technology, vol. 55(4), pp. 308-321, aug. 2017. https://iptek.its.ac.id/index.php/idea/article/view/4686/3357 https://iptek.its.ac.id/index.php/idea/article/view/4686/3357 https://iptek.its.ac.id/index.php/idea/article/view/4686/3357 https://iptek.its.ac.id/index.php/idea/article/view/4686/3357 https://iopscience.iop.org/article/10.1088/1742-6596/1450/1/012094/pdf https://iopscience.iop.org/article/10.1088/1742-6596/1450/1/012094/pdf https://iopscience.iop.org/article/10.1088/1742-6596/1450/1/012094/pdf https://iopscience.iop.org/article/10.1088/1742-6596/1450/1/012094/pdf https://iopscience.iop.org/article/10.1088/1742-6596/1450/1/012094/pdf https://doi.org/10.1016/s0890-6955(00)00104-8 https://doi.org/10.1016/s0890-6955(00)00104-8 https://doi.org/10.1016/s0890-6955(00)00104-8 https://doi.org/10.1016/s0890-6955(00)00104-8 https://doi.org/10.1115/1.2830087 https://doi.org/10.1115/1.2830087 https://doi.org/10.1115/1.2830087 https://doi.org/10.1115/1.2830087 https://doi.org/10.1016/j.ijmachtools.2009.10.005 https://doi.org/10.1016/j.ijmachtools.2009.10.005 https://doi.org/10.1016/j.ijmachtools.2009.10.005 https://doi.org/10.1016/j.ijmachtools.2009.10.005 https://www.ijriar.com/index.php/ijriar/article/view/359/343 https://www.ijriar.com/index.php/ijriar/article/view/359/343 https://www.ijriar.com/index.php/ijriar/article/view/359/343 https://doi.org/10.1007/s00170-003-1723-x https://doi.org/10.1007/s00170-003-1723-x https://doi.org/10.1007/s00170-003-1723-x https://doi.org/10.1007/s00170-003-1723-x https://doi.org/10.1016/j.procir.2019.04.300 https://doi.org/10.1016/j.procir.2019.04.300 https://doi.org/10.1016/j.procir.2019.04.300 https://doi.org/10.1016/j.procir.2019.04.300 https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.5 https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.5 https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.5 https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.5 https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.5 https://doi.org/10.1504/ijcat.2017.086015 https://doi.org/10.1504/ijcat.2017.086015 https://doi.org/10.1504/ijcat.2017.086015 https://doi.org/10.1504/ijcat.2017.086015 introduction ii. materials and methods a. method 1: two-point markings on x-axis 1) method 1 front side 2) method 1 back side b. method 2: two-point markings on y-axis 1) method 2 front side 2) method 2 back side c. method 3: four-point markings on x-axis plus two-point markings on y-axis 1) method 3 front side 2) method 3 back side d. method 4: four-point markings x-axis andy-axis with offset checking 1) method 4 front side 2) method 4 back side iii. results and discussions iv. conclusion acknowledgment declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.75-85 2088-6985 / 2087-3379 ©2020 research center for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. a study on the applicability of batik for public transportation design in indonesia yukhi mustaqim kusuma sya’bana a, *, gun bae park b a research centre for electrical power and mechatronics, indonesian institute of sciences (lipi) komplek lipi jl. sangkuriang, building 20, bandung 40135, indonesia b industrial design laboratory, art and design faculty, keimyung university 104 myeongdeok-ro, daemyeong 3(sam)-dong, nam-gu, daegu, 42403, republic of korea received 25 july 2020; accepted 3 november 2020; published online 22 december 2020 abstract this paper attempts to grant indonesian identity in the development and importing the public transportation equipment from overseas. we reviewed and surveyed the present state issues of indonesian public transportation equipment design development. the study analyzed the philosophical values of batik in a modern way, the possibility of batik application for important regionalism identity, and identity in design development strategy. as a result, we gather and assess the philosophical values of batik motifs that contain geographic origin, the essences, and characteristics to be applied as design element strategies. we found the regional identity of the historical, local wisdom essence, acculturation, various colors, and original shapes of the batik motifs. moreover, indonesian fancy design is also supported by other possibilities indigenous material and technique that usually used, particularly in indonesia. these possibilities were identically indonesian and also applicable as the sustainable public transport equipment design identity issue solution. this effort was conducted as the turning point to solve the issues of public transport equipment design strategies dependency. thus, this research will be helpful for aesthetics research in the modern way of the public transportation equipment design concept. ©2020 research center for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: batik philosophical values; public transportation equipment; national identity; vernacular design. i. introduction the transportation growth index was followed by congestion issues in indonesia. this situation was strongly related to the number of private vehicle usage, public transport equipment services satisfaction [1], road development growth, population, and urbanization. after postponed more than 20 years regarding the economic crisis issues, the mega project mass rapid transit (mrt) and bus rapid transit (brt) finally started in 2013. policies and road arrangement strategy also conducted to reduce congestion in indonesia, particularly jakarta as the indonesia capital city [2]. three pillars of transport solution concepts are developing public transportation systems, developing land transportation infrastructures, and managing traffic and transportation demands [3]. thus the high demand for using private vehicles will reduce people’s interest in using public transport in indonesia. these conditions assumed will affect the economic, social, and environmental aspects of the city. indonesia is the second biggest automotive manufacturing industry, following thailand in asean. this country has an important role in many automotive brands’ investment, especially in manufacturing hubs, to produce vehicles for export in asia and beyond. in the recent situation, indonesia has a large population and also rapid growth of the middle class. it also generates domestic market size for car sales above one million cars a year in 2016 [4]. local private industries or state-owned legal entities in indonesia were capable of producing public transport and equipment, e.g. ship, railway coach, aircraft, bus, light rail transit (lrt), metro capsule, and monorail. these abilities are mostly made domestically; the scope consists of covering components, support services, fabrication services, * corresponding author. tel: +62-222503055; fax: +62-222504773 e-mail address: yukh001@lipi.go.id https://dx.doi.org/10.14203/j.mev.2020.v11.75-85 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.75-85 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.75-85&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 76 installation services, engineering services, design, and maintenance with a limited scale. public transportation equipment development purposed to fulfill daily mobility commuter, leisure, and tourism public transport provision. attractive public transportation equipment demand plays an important role in design decisions to support new experiences of commuting, satisfaction, and quality. recently, primary transport development still depends on the overseas manufacturer brands due to their competencies, as seen in figure 1. providing local identity to become a national identity in public transport equipment is considered important to solve the design development issue. identity has a different level from national identity, regional identity, urban identity, and local identity [5]. while local identity should provide distinctive physical, social, historical, and aesthetic. at this time, was a lack of local design requirements role in the procurement of transportation facilities. a distinctive of local user behavior, identity, dimension, features, design sense, cultural promotion, these should be well designed by a local designer. considering the representation of local identity gives an innovative exploration spirit of the design era. it is intended to represent the character of the indonesian nation that distinguishes from other countries and raises the dignity aspect. moreover, dignity is a sense of pride in oneself, the state or quality of being worthy of honor or self-respect. a study stated the dignity of identity allows feelings of self-respect and pride and then became a critical component of workers' experience, especially in tourism [6]. the movement of local design identity applicability could be a trigger for another product, user experience, and designers in order to supports governments and local industries. it should start soon to get independent industrialization that will generate social, environmental, and economic welfare growth in the country. today, a creative economy involving a local identity is incision from sustainability, innovation, cultural diversity, and social inclusion [7][8]. for instance, the tourism industry in indonesia will relate with design as an innovation aspect, job opportunities as social inclusion aspect, preservation as cultural diversity aspect, and sustainability aspect. the recent situation has an issue to design indigenous culture strategy with wisely application, thus this paper attempts to confer indonesian national identity on public transport equipment development to be expensive, elegant, and fancy design. cultural preservation and create a niche market in transportation design is an opportunity to compete with foreign producers. this main study objective is to contribute relevant possibilities of reinterpretation vernacular indonesian batik concept onto the public transport design as seen in figure 2. mind mapping was conducted on the recent status of road public transportation development in indonesia. we highlighted the crucial keywords to be discussed in this paper, including national identity, local design strategy, culture, preservation, social innovation, applicability, and vernacular design. the one of vernacular design that was designed based on indigenous was called batik. the applicability, application possibility, or usefulness can be achieved by observing the design trends and the history of batik. this indonesian culture motif assumed has a lot of values that reflected the characteristics, identity, intrinsic philosophical meaning, and communication media in each of the regional motifs. the implied means of the local wisdom motifs, colors, and patterns were affected by the beginning of the acculturation religion era, ancient kingdom, trade activities, agricultural, colonialism, and local region cultures in the past [9]. in 2009, the united nations educational, scientific, and cultural organization (unesco) had accepted, and the indonesian government has officially declared batik as the national heritage of indigenous indonesian culture. the indonesian government had defined for celebrating batik national day every 2nd of october to celebrate when unesco recognized batik in 2009. the student and workers appealed to use batik every friday and, followed by civil servant minister of home affairs, established the rules in 2015. these current situations assumed batik take an important role as the national cultural identity of indonesian heritage. indonesia has over 13.000 islands with more than 720 languages, and 640 were recorded by unesco as well as there were 5.300 indigenous foods, and it was recorded motifs of batik unless a total of 5.489 and recently still counting [10]. pride in using batik as national identity impacted these motifs as embracing heterogeneous multiculturalism in indonesia. batik has amazed the world not as a souvenir and fabrics yet as artwork and elegant design from indonesia due to the values and life philosophy. handcrafting batik is unique and has a distinctive wax-resist dyeing process and coloring method. the waxing process of resisting the colors use a special tool called canting followed by coloring with dyeing technique, removing the wax with boil water, and repeating waxing intended for multiplying colors. however, the implementation of batik mainly applied to fashion and fabric media. batik motifs and processes were preserved and adaptable in each era. it was hereditary and depending on the demands and needs of the particular social community at the time. the contemporary sustainable batik has a wise value with using natural dye colors from eco-friendly plants and fruits; recycling used wax, natural drying rely upon the weather, electric smokeless wax figure 1. the interior design of jakarta mass rapid transit (mrt) is designed and produced by sumitomo corporation japan y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 77 heating stove, etc. contemporary motif and support of appropriate technology generate batik to become affordable items to all circles. hereditary factors (e.g., material, production method, technology, climate, region, and socialculture) were causing batik as the vernacular design of indonesia [11][12]. however, we assume it needs to improve the design methods and other applicability to be accepted, as seen in figure 3. mind mapping was conducted to extract and pursing the recent status of batik as vernacular design in indonesia. we highlighted the main study by applicability/feasibility, values/essence, and the art and design approach. in this paper, we shall argue the relationship and possibilities between vernaculars batik with the public transportation equipment design principles method approach. ii. materials and methods the attempt applicability of national identity to a fancy design strategy public transportation can be achieved in various ways. "three-levels of the emotional design" and culture level was applied to reinforce acceptance of the human-centered design [13]. the outer level is visceral design or tangible level related to appearance, form, color, line, texture, detail, physical, and material. secondly, mid-level or behavioral design related to function, usability, operation, safety, and user pleasure. lastly, the inner level or a reflective design related to self-image, affection, and cultural features. we selected art and design approach methods to cover the cultural level/emotional of batik, including kitsch, metaphor, affordance design, sustainable design, eco-design, appropriate technology design, and recycle. figure 2. mind mapping status and direction of road public transportation equipment in indonesia y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 78 a. design principles of vernacular batik and sustainable public transportation equipment vernacular is a term that is often used for linguistic and architectural, refers to indigenous or related to local distinctive and contextual philosophy, whether explicit or implicit in the population region. the vernacular model is divided into traditional and modern/contemporary vernacular [14][15], developed along with hereditary factors (i.e., material, production method, technology, climate, region, and social-culture). indigenous reinterpretation characterized by styles, morphological elements, and development techniques, in order achieved through a system of shared rules in their inhabitants. moreover, distinctive regional conservation took an important role in the local distinctiveness [16][17]. as such, regionalism with distinctive geography emphasizes optimizing the environment-behavior interaction as a consideration of sustainable vernacular design. as time goes by, a distinctive pattern changed, and man's development and achievements are affected by resources and technology in the past, present, and future. figure 3. mind mapping sustainable batik as indonesian vernacular design y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 79 b. kitsch the word 'kitsch' comes from germany and was used in 1925 for images of 'cheap'. by imitating noble behaviors and habits into daily, an imitation or aesthetic pantomime that is usually associated with an attempt to show the people's social status [18][19]. this industrial culture phenomenon generates art positioned as a creation that is controlled by market needs [20][21]. thus, the vernacular art handmade reinterpretation will become kitsch with contemporary material and mass production techniques as today's daily application. in history, batik was and sacred clothing; no one wears them except the palace family [22][23]. indeed, at that time, batik not merely as a decoration or royal ornaments itself yet became an appliance to held ritual of the kingdom. batik was turned out to be the trigger of the social gap between the nobles with the indigenous people. the art of batik was dominance by the nobility and later, batik almost became a media of breaking the tough conflicts. however, as time goes by, this gap disappears, and almost everybody uses it. generated by developments of the production technique, the special craftsmen technique of waxing with special tools called canting was replaced with modern coloring, printing, drawing, stamping, etc. the process of manual waxing batik with natural colors also takes a long time regarding the coloring processes are repeatedly. as a result, traditional batik prices are sold more expensive per sheet compared with the modern production method. c. sustainable design sustainable batik development is how to improve the environment by compromising economic and social factors. the three main pillars (economic, social, and environmental) are interdependent and reinforcing [24]. sustainable development is linked to economic growth and how to find ways to advance the economy over the long term, without depleting natural capital. resources on the earth are limited; thus this effort was to fulfill today’ s needs without sacrificing future generations. cultural diversity, in this case batik is important for sustainable development policy as well as the importance of biodiversity to intellectual, emotional, moral, and spiritual. d. eco design eco-design, design for sustainability, or green design is a product designing approach with considering environmental effects. it involves optimizing the entire life-cycle of each product from the design phase to production, consumption, and disposal. vernacular using local raw materials are more economical, reduces the costs of shipping, fuel consumption, and co2 emissions produced from transportation and mobility. household and industrial deliver large contribution of river waste that exacerbates pollution generate environmental damage in general. clean production and utilize appropriate technology concepts need to initiate to produce sustainable batik. chemical-based coloring agent manufacturing will generate waste and pollution. in contrast, some examples of natural colors that eco batik used were brown color from coconut fiber or tea leaves, yellowish red color from cinnamon, yellow color from turmeric, blue color from indigo leaves, and reddish-brown from mango peels. batik natural dyes coloring material is using parts of plants, such as leaves, skin, stems, seeds, fruits, and flowers [25][26]. this includes safe waste management, in which all batik production waste would be first processed and wasteless for the rivers. among the initiatives proposed in this stage includes the acceleration of the reforestation movement by cultivating forests of natural dye-producing plants. besides, using environmentally friendly technologies such as the batik process is using natural dyes generates a soft color than chemical dyes. e. recycle several raw materials used for products are recyclable to be another valuable new object that requires energy to process [27][28]. at the end of the life-cycle, waste should be reduced or reused intact items as a diminishing impact on the environment [29][30]. consideration of recycling in the designing process involving manufacture, assembly, and material processing [31][32][33]. waste of wax also can be reused and recycle to emphasize the production costs as applied in some small industries of batik. moreover, using natural dyes without damaging the growing plants are possible to conduct. recycle natural waste from household and furniture industries such as plants, fruits skin, wood skin, wood waste, etc. as an example, the city that produced batik, such as cirebon, has many furniture industries and produces waste of wood shavings. in pekalongan city, many supermarkets are throwing rotten fruit that the potential to conduct recycling. patchwork scraps of batik also applicable to be a recycled aesthetics element of artworks or mix media of contemporary paintings and generate new values either economics or aesthetics. f. appropriate technology design commonly known as choice of technology within the application were decentralized characteristic, labor-intensive, small-scale, low energy used, and related to the local condition. generally, appropriate technology adapted to the environmental, ethnic, cultural, social, political, and economic aspects of the community concerned. appropriate technology is usually applied to describe simple technologies that are emphasized to the user that suitable for developing countries or else underdeveloped rural areas in industrialized countries [34][35]. batik is made from natural dyes parts of plants, such as leaves, skin, stems, seeds, fruits, and flowers to make the production methods environmentally friendly and add more quality values. it possible to adapting intermediate technology in the community; however only those technologies have found acceptance in those mentioned aspects y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 80 conditions prevailing in the developing country [36]. the vernacular concept needs appropriate technology design that will accept regionalism and improve the quality of life. starting from coloring to drying, the production of batik uses a material provided by nature. various advantages are ranging from resistance to acid (sweat), resistance to fade, and heat. in addition, the brilliance of the resulting colors is also more durable and stable. appropriate technology in batik production, for example with an electric stove, will have significant savings compared to oil base and gas stove. the absence of firewood burning in the eco batik method also does not produce smoke and no burning charcoal for perfect combustion as environmentally friendly. it also uses a blower to dissolve the remainder of the candle more efficiently, usually ineffective with a fuel base burning method. the room lighting also applied solar plastic bottle lamps that use only bottles of soft drink filled with chlorine and given water. the bottle is placed on the roof and instantly produces a glow of light equivalent to 55 watts that generate energy efficiency and cost. the last stage is the drying process, which is depending on the wind and the weather. usually, it would take a long time depends on nature. lastly, the oven/heating process obviously will make the candle/wax melting. g. affordance design quality of an object that allows an individual to perform an action, in short, the physical properties of an object should suggest how it should be used. interaction between humans and products involving visual (how it should be used), perceived (how it might be used), perceptual (five senses), and functional (design quality, effectiveness, usefulness) [37][38]. the tangibility of the meaning in the vernacular concept assumed determines an affordance quality on the application [39][40]. the special tools for making batik called "canting", the term was from the javanese language. the tool used to move or take the hot wax liquid and write into the fabrics to generate batik. traditional canting for batik is a small tool made of copper and bamboo as a handle. it contains gagang, nyamplung, and cucuk. as the intuitive behavior like a pen to writing in the media, gagang or canting handle generally made of bamboo or wood. another part called nyamplung that is a container for taking hot wax fluids in the iron skillet above the stove and it’ s made of copper. lastly, cucuk that is connected with nyamplung that shaped like a curve pipe has a function to drain the wax from nyamplung to scratch into the fabric, as shown in figure 4. h. metaphor design etymologically it was defined as the use of words rather than the real meaning, for rhetorical effect and comparison. the metaphor method used to identify, frame, and to solve design problems aims to enhance product meaningfulness and appeal. the metaphors underlie how people think, reason, and imagine in everyday life in case tangible, intangible, or combined. the metaphor technique and simplification method resulted in superior memory and identification of an interaction between human and design interaction [41]. the feasibility of metaphor design as an affordance design in the vernacular aspect should be investigated to a better quality of usability design [42][43]. the wide diversity of batik patterns reflects a variety of metaphor influences, ranging from arabic calligraphy, european bouquets, and chinese phoenixes to japanese cherry blossoms and indian or persian peacocks. iii. results and discussions a. design value and applicability of batik batik is mostly recognized as a unique process in making fabrics with distinctive motives and fashion applications. batik variances and applications are dynamic and adaptable in the past, present, and future for all ages. recently batik also used in various media as an aesthetic element of decorating, household accessories, and fashion development. a glance at recent indonesian public transportation development feasibility, will reflect decent circumstances, national characteristics, and identify the cultural diversity of particular social groups in indonesia. batik’ s applicability to public transport necessary for design identity strategy, considering that every motif of batik has different symbolic meaning values as independent local design movement. recently the waning of authentic batik is gripping; furthermore, necessary to figure out the essence of motifs to apply for various media in public transportation equipment. batik as strategy and suggestion in design briefed narrowed by several keywords. we highlighted mind mapping, including vernacular design, design concept, applicability, identity, pattern, essence to be applied in public transportation equipment design, as seen in figure 5. generally, batik that was established from javanese culture was divided into inland and coastal type. inland (keraton) batik has earthy colors, geometric shapes, elements, and is made from natural coloring textile dyes. on the contrary, coastal (pesisir) batik has vibrant colors, non-geometric (organics) shape, natural motifs, and influenced by wide acculturation of maritime and trading culture. overall, the patterns are influenced by the acculturation of india, european, japanese, persian, figure 4. affordance design of canting or the batik coloring pen y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 81 and religions of islam, hindu, and buddha. the motifs are mainly classified with geometrical shape, flora, fauna, and nature objects (e.g. rocks, sky, clouds, etc.). through this study, batik motifs were compared by its influences, founded, characteristics, meanings (values), and pattern images as shown in table 1 and figure 6. b. applicability value to the public transportation equipment design batik motifs feasibility as the design concept of public transportation equipment is necessary. it is considering that the development still depends on imports from overseas and the various positive implicit meanings from thousands of batik motifs. the applicability of batik needs to emphasize the suitable requirement, wise application, and consider the essence meanings for developing the public transportation equipment issue. application batik to public transportation equipment needs particular consideration in order that the motifs have a positive image and nationality reflection, high values, taste, historical track record, and artistic initiative. in the past, some batik needs to conduct a particular ritual like soaking the fabrics for 40 days and nights intended or appealing the aura. another special ritual was founded with fasting, ascetic, and many more. the suitable motif selection and color application adapt to the public transport and the equipment concept in order each pattern, lines, and dots of batik motif implicit social hierarchy, hope and pray. indonesia, which in developing public transportation equipment, needs to consider the concept of batik motifs of rising, resurrection, nationalism, independent, distinctive area, rapid and hoping to the better future of sustainable transportation. c. integrating batik application possibilities to sustainable transportation product design synthetically applies science and technology to design and objects. to create products that will enjoy by most people, both functionality and modern aesthetics necessary to be considered by designers. moreover uses their scientific techniques or personal artistic talents, but also combine them together and to be a fun design product that can be used. modern product design intended to acquire the concept of traditional culture, social ideals, and laws of nature. besides integrating with inward forms and functions, human coordinating system, engine, and environment. indonesia, as a developing country in south east asia, has several public transportation system futures. usually, the concept adopts rapid transportation technologies from abroad. the procedures are through government procurement of goods and services from abroad with the state budget. product design offers an option to combine sciences, technology, function, innovate product form, structure, enhance cultural significance, and consuming taste to the new concept of contemporary design. in order, it’s emphasized for most people with particular markets. modern influence styles of other variances fabrics from abroad are one of a factor that leads to decreased interest in using batik. integrating batik as the national identity culture onto those developments concept is a feasible challenge, in view of the transportation function to daily mobility. batik privileges have a lot of patterns, motifs, and different philosophical and historical values in almost every region, the distinctive blend of colors and how to create them make more value which other countries do not have. batik is commonly used as a fashion application either traditional or modern contemporary yet rarely applications to another form such as public transport either vehicle or infrastructure. among urban transportation and mobility applications, batik has wide motifs and meanings. the fields of social design place it as an alternative replacement for automotive fabrics and formalistic in aesthetics. it is an advantage to position the reinterpretation in regard to the effort to raise up interest and recognition of cultural identity factors. inheriting batik elements ideals are with applying batik visual elements form in colors and graphs (imitating, decomposition, and reconstruction also figure 5. mind map sustainable batik as indonesian vernacular design y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 82 digging principle) and lastly applying the structures. the meaning and theory of vernacular batik as traditional elements will helpful for aesthetics research in modern product design. d. inheriting of batik motifs, comprehension, and decomposing one of batik’s producers in west java was in cirebon city, as the origin of coastal batik, the pattern was influenced by the location and as a harbor from the past. this city was merrier visited by trading activities from either local or international. the activities also generate new ideologies from multicultural effects; this city also one of the islamic spreading centers in west java. the characteristics are that using a bright color, asymmetrical, and drawn on plain media. the objects that simplified metaphor from the kingdom circumstances were plants, mythology animals, wings form, jewelry, and cloudy cloud. in every form were also implied particular meanings. table 1. the distribution mapping of batik based on regional characteristics and substances description pattern image pattern name kawung figure 6(a) influence native indonesia founded inland mid java characteristics • earthy colours i.e. black, indigo, brown, and sogan (brown-yellow colour) generated from eco-friendly natural colouring techniques. • metaphor from arenga pinnata fruit that has an oval shape with opaque white colour and others believe from the shape of kwangwung (oryctes rhinoceros). meanings clean heart, useful for people, national unity and the symbol of wise, wisdom, and self-control. pattern name parang figure 6(b) influence native indonesia founded inland mid java , mataram kartasura (solo city) characteristics • identical with a group of slash motifs that are arranged with parallel lines of an oblique angle. • the sustain arrangement like "s" letters taken from the metaphor of ocean waves. meanings • a spirit that never extinct, efforts to improve and stand up for welfare and kinship. • the straight diagonal line represents respect, ambition, and loyalty to the true value. • the dynamics in this parang pattern are also called agility, alertness, and continuity between workers. pattern name paksi naga liman figure 6(c) influence acculturation indonesian with persian, india and china with spreading religion of islam, hindu and budha. founded coastal of west javanese region (cirebon city) characteristics this motif represents a sacred cart with three legendary hieratic animals, which are paksi (garuda bird), naga (dragon), liman (elephant). meanings whole glory sovereignty, bird as guardians of sovereignty in the air (jaya dirgantara), dragon as guardian of sea sovereignty (jaya bahari) and elephant as a guardian of sovereignty on land (jayabhumi) pattern name hokokai figure 6(d) influence acculturation indonesian and japanese founded coastal of mid javanese region (pekalongan city) characteristics a vibrant colour like other coastal motifs made as an offering to the new ruler of that era by aligning the motifs and ornaments made with japanese taste. meanings discipline or perfection in self-control. remembering the grapple of pekalongan batik craftsmen indonesia was independent from japan colonialism. (a) (b) (c) (d) figure 6. batik pattern image; (a) kawung; (b) parang; (c) paksi naga liman; and (d) hokokai y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 83 the motifs and color decomposition and reconstruction were a connector method to integrate forming that is usually used in modern designing. it was evolved the elements of a new form that generate from basic comprehension of original motifs. colors decomposition as for the redesigning of traditional colors in public transportation equipment, the designer needs to analyze the characteristics, function, principal, and role of the colors, composition, and forms of vernacular batik. "mega mendung" or cloudy cloud with darken sky become raining is the motif with clouds pattern has a meaning and deep philosophy. the message contains a desire for patient attitude and cooling down circumstances with seven gradations from dark into light blue. wide cloud and overcast are elements also mean to illustrate the cirebon palace shade or protecting their people. as stated before that this motif was affected by multicultural activities in the past; the differences with chinese cloud patterns are more sharp lines and presenting gradation colors, as shown in figure 7. e. reinterpretation to contemporary public transportation equipment design concepts the product design process is generating ideas and developing into a final product to be consumed. the approach adopted in this complex problem is based on the design for affordability. designers should consider systems, services, and products in relation to what they should do, how they should behave, what they look like, and whether they will be understood by the users in the manner intended. the starting point for solving a problem springs from an idea developed in mind. a detailed exploration of the idea is vital to take it from the intangible to the tangible, along with the ability to articulate the idea to others. a carriage for the queen palace called jempana, or in term of local language jemjeming prana which means loyalty or jemjeming pengagem manahayang which means the persistence of heart. at the top of the throne is a kind of metal umbrella decorated with mega mendung motifs, element sizing the human soul that can protect individuals, families, relatives, and society. this batik motif has been applied to the transportation system in the year 1428, as shown in figure 8. an integrating as contemporary design today will have a different appearance and feels, in other words the design will ever-changing due to the past, today, and future developments such as technology, material, etc. it is always evolving and easily adapt the other styles and values like batik vernacular elements concept. the concept of autonomous electric vehicles by honda was called neuv. it is equipped with artificial intelligence, a full-touch panel interface, and two seats capacity. the headlight concept wants to present an organic line, something floating like the tail of clouds. it is also proof that reinterpretation of a metaphor concept like batik mega mendung and possible to conduct even to other parts of vehicles either interior or exterior, whether explicit or implicit as shown in figure 9. f. the applicability of vernacular indonesian technique and material every country has various distinctive production techniques to supports the products. the characteristic of vernacular design shows the dependency of skill, experience, and talent obtained by hereditary. many peoples use an indigenous technique with natural materials while the others adopt modern with non-natural materials or combined of both. usually, the technical process could be applied to materials of stones, natural or artificial fibers, leather, rattan, bamboo, wood, metals (gold, silver, copper, bronze, and iron), wood, glass, porcelain, fabric, marble, and clay. batik, as an indigenous motif represents indonesian culture, necessarily to discover the applicability of the motifs in vernacular material and production. firstly, the possible material to be applied in public transport is leather that is produced with various scales from handicraft to heavy industry. leather has a durable and flexible characteristic created with tanning animal rawhides. mainly this material used as clothing, shoes, coat, and fashion accessories nevertheless as well as applied for musical instruments supports. the leather carving method founded in indonesia was applied as a shadow puppet material called wayang kulit that mainly founded in central java and east figure 8. batik application in the past was applied to kereta jempana traditional four wheels carrier figure 7. mega mendung or cloudy cloud is the brilliant colours of coastal batik vibrant colours, non-geometric (organics) shape, natural motifs and influenced from wide acculturation of maritime and trading culture mostly from chinese figure 9. headlight concept of honda neuv y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 84 java. this puppet played at night with narration and traditional music with screen and lighting, allowing the audiences to watch only the shadow or from the puppeteer side. wayang kulit was also approved by unesco in 2003 as (masterpiece of oral and intangible heritage of humanity) usually used as a tool for spreading thought, education, science, and information. made from cattle, cow, buffalo, or ox leather with a particular preparation before it is carved. in contrast, this preparation makes the leather rigidly, translucent, easy to carving, transparent also long-lasting material as shown in figure 10. moreover, this shadow puppet believes are brought to indonesia from the trading activity of india spreading the hindustan religion. showed the similarities of the shadow puppet show, founded in andra pradesh india called tholu bommalata with typical leather differences of animals skin material, story show content, puppet character, musical instrument, and motifs. some puppets are made from more than one type of skin instead of a cow considering religion issues in india; these are antelope, spotted deer, and goat. this shadow puppet also founded in some countries like cambodia, thailand, malaysia, chinese, taiwan, italy, and australia, with each typical characteristic. one of the indonesian woodcraft is an engraved handheld folding fan made from cendana tree/sandalwood that was founded in nusa tenggara, indonesia. recently, it is often used as a dance performance equipment and souvenir from indonesia. cendana derived from a sanskrit term in latin is called santalum album l. include to santalaceae family. instead of furniture function, sandalwood is often used as carving material, keris (ceremonial knife) and generates oil for herbal medicine, aromatherapy, antiseptic, antimicrobial, cosmetics and gives a luxury impression. while others believe as an alternative medicine to bring people closer to god. the base oil of sandalwood, which is very expensive in its pure form, is used primarily for healing the ayurveda way and to relieve anxiety. moreover, folded handheld fans are popular in europe during the eighteen century. various material combinations are applied such as gold, tortoiseshell, ivory, mother-of-pearl, horn, or wood. other countries also have this type of handheld fan, which is chinese and japan as shown in figure 11. the acculturation in the past, especially overseas trading activity in indonesia generates a particular culture and craftsmanship. as time goes by, modern cultures assumed affecting the interest of local culture. at the time, millennials should develop the preservation of cultural heritage along with modern life. in order, the workmanship difficulties and knowledge transfer as the factor this issue and the culture become faded even extinct. applicability of the traditional material into the indigenous pattern such as batik will generate the identity mark of indonesia luxurious. the results hopefully, will encourage sustainable culture and preservation. iv. conclusion a study has been conducted to solve the identity design problem in public transportation equipment development in indonesia. the values of batik were gathered, assessed, and proved that contains geographic of origin, the essences, and characteristics to be applied as design element strategies. we found the regional identity of the historical, local wisdom essence, acculturation, various colors, and original shapes of the batik motifs. moreover, indonesian fancy design is also supported by other possibilities indigenous material and technique that usually used, particularly in indonesia. these possibilities were identically indonesian and also applicable as the sustainable public transport equipment design identity issue solution. advanced technology should evolve not to resist along with the indigenous lifestyle to conserve it. public transportation equipment development concept for daily mobility activities and tourism played a role as feasible media to apply the vernacular batik concept to expose the national cultural identity. this design approach can bring significant values of cultural values, market values, and social values. at the same time, as the universal culture elements, the product can transmit traditionally and advanced culture and create a fashionable new culture, and bring the cultural values to people. culture always spreads with the product and then can be understood and accepted. thus, the product can show commonalty consuming concepts, people’s values expecting about future lifestyle and up-to-date ideology. by applying the vernacular element in modern product design, it is useful to define product functions, innovative product form, and structure and to enhance the cultural significance and consuming taste, carve out a new market. the application of traditional cultural symbols in modern product design helps to explore new methods and enrich up-to-date design culture. declarations author contribution y.m.k sya’bana and g.b park contributed equally as the main contributor of this paper. all authors read and approved the final paper. figure 10. the process of pre-colouring wayang kulit leather. (a) (b) figure 11. handheld fan: (a) chinese hand fan; (b) indonesian cendana hand fan. y.m.k. sya’bana and g.b. park / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 75-85 85 funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] s. sutia, s. adha, and m. fahlevi, “why do customers intend to repurchase transportation online in indonesia?,” e3s web conf., vol. 125, no. 201 9, pp. 9–13, 2019. [2] badan pusat statistik, “stastika transportasi dki jakarta,” 2015. [3] s. soehodho, “public transportation development and traffic accident prevention in indonesia,” iatss res., vol. 40, no. 2, pp. 76–80, 2017. [4] indonesia-investments, “automotive manufacturing industry indonesia,” 2017. [5] y. shao, e. lange, k. thwaites, and l. binyi, “defining local identity,” landsc. archit. front., vol. 5, no. 51678417, pp. 24– 41, 2017. [6] a. winchenbach, p. hanna, and g. miller, “rethinking decent work: the value of dignity in tourism employment,” j. sustain. tour., vol. 27, no. 7, pp. 1026–1043, 2019. [7] r. p. canaan, “creative economy and cultural heritage: a proposal to tourism development and appreciation of local identity,” strateg. des. res. j., vol. 12, no. 2, pp. 276–288, 2019. [8] s. z. abidin, a. othman, z. shamsuddin, z. samsudin, h. hassan, and w. a. w. mohamed, “malaysian product design identity: issues, transformation, and challenges,” in proceedings of the 2nd international colloquium of art and design education research (i-cader 2015), singapore: springer singapore, 2016, pp. 305–318. [9] a. rahma, j. jaenudin, and a. marifatullah, “living a multicultural lifestyle with batik: identity, representation, significance,” in international conference on culture and language in southeast asia (icclas 2017), 2018, vol. 154, no. icclas 2017, pp. 203–205. [10] beritagar.id, “indonesia punya 5.849 motif batik,” 2015. [11] n. tresnawati, i. saleh, sudarmin, and s. wardani, “scientific reconstruction of local plants as the basic materials of batik natural dyes,” j. phys. conf. ser., vol. 1511, no. 1, 2020. [12] m. t. nawawi and r. rodhiah, “swot analysis on the smes of batik products in jambi city,” 8th int. conf. entrep. bus. manag. untar (icebm 2019), vol. 145, no. icebm 2019, pp. 356–360, 2020. [13] j. mao et al., “application of emotional design to the form redesign of a midwifery training aid,” kne eng., vol. 2, no. 2, p. 44, 2017. [14] e. shrestha, “vernacular architecture in contemporary context in the outskirts of kathmandu valley,” b.s. thesis, sch. of education., kathmandu university, pp. 1–18, 2019, [online]. available. [15] j. al-qawasmi, “vernacular as a renewable resource: toward region-specific architecture in saudi arabia, a case from kfupm,” archit. eng. des. manag., vol. 12, no. 2, pp. 81–96, 2016. [16] s. t. f. poon, “contribution of ecological design to critical regionalism: analysing sustainability effectiveness in vernacular urban building,” isprs ann. photogramm. remote sens. spat. inf. sci., vol. 4, no. 4/w9, pp. 103–109, 2019. [17] t. chotpradit et al., “terminologies of ‘modern’ and ‘contemporary’ ‘art’ in southeast asia’s vernacular languages: indonesian, javanese, khmer, lao, malay, myanmar/burmese, tagalog/filipino, thai and vietnamese,” southeast now dir. contemp. mod. art asia, vol. 2, no. 2, pp. 65–95, 2018. [18] c. c. c. stefan a. ortlieb, “kitsch and perception: towards a new ‘aesthetic from below,’” art percept., vol. 7, no. 1, pp. 1– 26, 2019. [19] g. tedman, “origins of kitsch,” rethink. marx., vol. 22, no. 1, pp. 56–67, 2010. [20] m. kjellman-chapin, “the politics of kitsch,” rethink. marx., vol. 22, no. 1, pp. 27–41, 2010. [21] c. greenberg, “avant-garde and kitsch,” a hist. west. art mark., pp. 24–27, 2020. [22] i. ratnawati, triyanto, and syakir, “meanings possessed by gajah oling batik in seblang rituals performed by osing tribe in banyuwangi,” int. j. recent technol. eng., vol. 8, no. 2 special issue 9, pp. 183–186, 2019. [23] p. nimas ayu, n. a. pramesti, h. pamadhi, and a. garbo, “local wisdom values in kawung batik and its relevance to moral education,” in proceedings of the international conference on art and arts education (icaae 2018), 2019, vol. 327, no. icaae 2018, pp. 178–182. [24] y. mustaqim and k. sya, “the applicability of sustainable design values on electric bike sharing concept in indonesia,” 2019 int. conf. sustain. energy eng. appl., pp. 125–130, 2019. [25] d. widiawati, “the utilization of batik pattern and natural dyes as valuation of the local value fan batik society,” sosioteknologi (sostek), pp. 5–7, 2018. [26] a. alamsyah, s. maziyah, and a. supriyono, “natural coloring as a coloring material for batik craft in jepara,” in proceedings of the 4th international conference on indonesian social and political enquiries, icispe 2019, 2020, pp. 1–8. [27] l. magnier, r. mugge, and j. schoormans, “turning ocean garbage into products – consumers’ evaluations of products made of recycled ocean plastic,” j. clean. prod., vol. 215, pp. 84–98, 2019. [28] j. shi, q. li, h. li, s. li, j. zhang, and y. shi, “eco-design for recycled products: rejuvenating mullite from coal fly ash,” resour. conserv. recycl., vol. 124, no. december 2016, pp. 67– 73, 2017. [29] s. k. venkatachary, r. samikannu, s. murugesan, n. r. dasari, and r. u. subramaniyam, “economics and impact of recycling solar waste materials on the environment and health care,” environ. technol. innov., vol. 20, p. 101130, 2020. [30] l. w. zhang, a. o. sojobi, v. k. r. kodur, and k. m. liew, “effective utilization and recycling of mixed recycled aggregates for a greener environment,” j. clean. prod., vol. 236, p. 117600, 2019. [31] h. li and k. englund, “recycling of carbon fiber-reinforced thermoplastic composite wastes from the aerospace industry,” j. compos. mater., vol. 51, no. 9, pp. 1265–1273, 2017. [32] a. mayyas, d. steward, and m. mann, “the case for recycling: overview and challenges in the material supply chain for automotive li-ion batteries,” sustain. mater. technol., vol. 19, p. e00087, 2019. [33] g. harper et al., “recycling lithium-ion batteries from electric vehicles,” nature, vol. 575, no. 7781, pp. 75–86, 2019. [34] h. shin, j. hwang, and h. kim, “appropriate technology for grassroots innovation in developing countries for sustainable development: the case of laos,” j. clean. prod., vol. 232, pp. 1167–1175, 2019. [35] d. okoye, “appropriate technology and income differences,” int. econ. rev. (philadelphia)., vol. 57, no. 3, pp. 955–996, 2016. [36] d. musunuri, “appropriate technology and economic development of emerging economies a myth or a reality,” j. technol. manag. grow. econ., vol. 5, no. 1, pp. 51–62, 2014. [37] s. moussawi, “user experiences with personal intelligent agents,” in proceedings of the 2018 acm sigmis conference on computers and people research, pp. 86–92, 2018. [38] j. haase, k. p. wiedmann, and j. bettels, “sensory imagery in advertising: how the senses affect perceived product design and consumer attitude,” j. mark. commun., vol. 26, no. 5, pp. 475–487, 2020. [39] h. jung, h. wiltse, m. wiberg, and e. stolterman, “metaphors, materialities, and affordances: hybrid morphologies in the design of interactive artifacts,” des. stud., vol. 53, pp. 24–46, 2017. [40] l. h. chen and y. c. liu, “affordance and intuitive interface design for elder users with dementia,” procedia cirp, vol. 60, pp. 470–475, 2017. [41] c. y. tsai, “effect of graphic simplification and graphic metaphor on the memory and identification of travel map signs running head,” int. j. ind. ergon., vol. 61, pp. 29–36, 2017. [42] m. k. rasmussen, g. m. troiano, m. g. petersen, j. g. simonsen, and k. hornbæk, “the new thinking in emotional user experience: from visual metaphor to interactive affordance,” conf. hum. factors comput. syst. proc., pp. 490–497, 2016. [43] s. y. kim and e. mcfadden, “using established ux design techniques and visual enhancements to redesign an enterprise mobile app and improve employee productivity and engagement,” in advances in intelligent systems and computing, vol. 972, pp. 169-176, 2020. https://doi.org/10.1051/e3sconf/201912523010 https://doi.org/10.1051/e3sconf/201912523010 https://doi.org/10.1051/e3sconf/201912523010 http://jakarta.bps.go.id/backend/pdf_publikasi/statistik-transportasi-dki-jakarta-2015.pdf https://doi.org/10.1016/j.iatssr.2016.05.001 https://doi.org/10.1016/j.iatssr.2016.05.001 https://doi.org/10.1016/j.iatssr.2016.05.001 https://www.indonesia-investments.com/business/industries-sectors/automotive-industry/item6047 https://www.indonesia-investments.com/business/industries-sectors/automotive-industry/item6047 http://journal.hep.com.cn/laf/en/10.15302/j-laf-20170203 http://journal.hep.com.cn/laf/en/10.15302/j-laf-20170203 http://journal.hep.com.cn/laf/en/10.15302/j-laf-20170203 https://doi.org/10.1080/09669582.2019.1566346 https://doi.org/10.1080/09669582.2019.1566346 https://doi.org/10.1080/09669582.2019.1566346 https://doi.org/10.4013/sdrj.2019.122.12 https://doi.org/10.4013/sdrj.2019.122.12 https://doi.org/10.4013/sdrj.2019.122.12 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.1007/978-981-10-0237-3_31 https://doi.org/10.2991/icclas-17.2018.50 https://doi.org/10.2991/icclas-17.2018.50 https://doi.org/10.2991/icclas-17.2018.50 https://doi.org/10.2991/icclas-17.2018.50 https://doi.org/10.2991/icclas-17.2018.50 https://beritagar.id/artikel/gaya-hidup/indonesia-punya-5849-motif-batik https://doi.org/10.1088/1742-6596/1511/1/012062 https://doi.org/10.1088/1742-6596/1511/1/012062 https://doi.org/10.1088/1742-6596/1511/1/012062 https://doi.org/10.2991/aebmr.k.200626.061 https://doi.org/10.2991/aebmr.k.200626.061 https://doi.org/10.2991/aebmr.k.200626.061 https://doi.org/10.2991/aebmr.k.200626.061 https://doi.org/10.18502/keg.v2i2.594 https://doi.org/10.18502/keg.v2i2.594 https://doi.org/10.18502/keg.v2i2.594 https://www.academia.edu/38247325/vernacular_architecture_in_contemporary_context_in_the_outskirts_of_kathmandu_pdf https://www.academia.edu/38247325/vernacular_architecture_in_contemporary_context_in_the_outskirts_of_kathmandu_pdf https://www.academia.edu/38247325/vernacular_architecture_in_contemporary_context_in_the_outskirts_of_kathmandu_pdf https://www.academia.edu/38247325/vernacular_architecture_in_contemporary_context_in_the_outskirts_of_kathmandu_pdf https://doi.org/10.1080/17452007.2015.1109497 https://doi.org/10.1080/17452007.2015.1109497 https://doi.org/10.1080/17452007.2015.1109497 https://doi.org/10.1080/17452007.2015.1109497 https://doi.org/10.5194/isprs-annals-iv-4-w9-103-2019 https://doi.org/10.5194/isprs-annals-iv-4-w9-103-2019 https://doi.org/10.5194/isprs-annals-iv-4-w9-103-2019 https://doi.org/10.5194/isprs-annals-iv-4-w9-103-2019 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1353/sen.2018.0015 https://doi.org/10.1163/22134913-00001091 https://doi.org/10.1163/22134913-00001091 https://doi.org/10.1163/22134913-00001091 https://doi.org/10.1080/08935690903411644 https://doi.org/10.1080/08935690903411644 https://doi.org/10.1080/08935690903411578 https://doi.org/10.1080/08935690903411578 https://doi.org/10.1525/9780520340770-005 https://doi.org/10.1525/9780520340770-005 https://doi.org/10.35940/ijrte.b1040.0982s919 https://doi.org/10.35940/ijrte.b1040.0982s919 https://doi.org/10.35940/ijrte.b1040.0982s919 https://doi.org/10.35940/ijrte.b1040.0982s919 https://doi.org/10.2991/icaae-18.2019.34 https://doi.org/10.2991/icaae-18.2019.34 https://doi.org/10.2991/icaae-18.2019.34 https://doi.org/10.2991/icaae-18.2019.34 https://doi.org/10.2991/icaae-18.2019.34 https://doi.org/10.1109/icseea47812.2019.8938654 https://doi.org/10.1109/icseea47812.2019.8938654 https://doi.org/10.1109/icseea47812.2019.8938654 https://doi.org/10.5614%2fsostek.itbj.2018.17.2.3 https://doi.org/10.5614%2fsostek.itbj.2018.17.2.3 https://doi.org/10.5614%2fsostek.itbj.2018.17.2.3 https://doi.org/10.4108/eai.21-10-2019.2294350 https://doi.org/10.4108/eai.21-10-2019.2294350 https://doi.org/10.4108/eai.21-10-2019.2294350 https://doi.org/10.4108/eai.21-10-2019.2294350 https://doi.org/10.1016/j.jclepro.2018.12.246 https://doi.org/10.1016/j.jclepro.2018.12.246 https://doi.org/10.1016/j.jclepro.2018.12.246 https://doi.org/10.1016/j.jclepro.2018.12.246 https://doi.org/10.1016/j.resconrec.2017.04.005 https://doi.org/10.1016/j.resconrec.2017.04.005 https://doi.org/10.1016/j.resconrec.2017.04.005 https://doi.org/10.1016/j.resconrec.2017.04.005 https://doi.org/10.1016/j.eti.2020.101130 https://doi.org/10.1016/j.eti.2020.101130 https://doi.org/10.1016/j.eti.2020.101130 https://doi.org/10.1016/j.eti.2020.101130 https://doi.org/10.1016/j.jclepro.2019.07.075 https://doi.org/10.1016/j.jclepro.2019.07.075 https://doi.org/10.1016/j.jclepro.2019.07.075 https://doi.org/10.1016/j.jclepro.2019.07.075 https://doi.org/10.1177/0021998316671796 https://doi.org/10.1177/0021998316671796 https://doi.org/10.1177/0021998316671796 https://doi.org/10.1016/j.susmat.2018.e00087 https://doi.org/10.1016/j.susmat.2018.e00087 https://doi.org/10.1016/j.susmat.2018.e00087 https://doi.org/10.1016/j.susmat.2018.e00087 https://doi.org/10.1038/s41586-019-1682-5 https://doi.org/10.1038/s41586-019-1682-5 https://doi.org/10.1016/j.jclepro.2019.05.336 https://doi.org/10.1016/j.jclepro.2019.05.336 https://doi.org/10.1016/j.jclepro.2019.05.336 https://doi.org/10.1016/j.jclepro.2019.05.336 https://doi.org/10.1111/iere.12182 https://doi.org/10.1111/iere.12182 https://doi.org/10.15415/jtmge.2014.51003 https://doi.org/10.15415/jtmge.2014.51003 https://doi.org/10.15415/jtmge.2014.51003 https://doi.org/10.1145/3209626.3209709 https://doi.org/10.1145/3209626.3209709 https://doi.org/10.1145/3209626.3209709 https://doi.org/10.1080/13527266.2018.1518257 https://doi.org/10.1080/13527266.2018.1518257 https://doi.org/10.1080/13527266.2018.1518257 https://doi.org/10.1080/13527266.2018.1518257 https://doi.org/10.1016/j.destud.2017.06.004 https://doi.org/10.1016/j.destud.2017.06.004 https://doi.org/10.1016/j.destud.2017.06.004 https://doi.org/10.1016/j.destud.2017.06.004 https://doi.org/10.1016/j.procir.2017.02.015 https://doi.org/10.1016/j.procir.2017.02.015 https://doi.org/10.1016/j.procir.2017.02.015 https://doi.org/10.1016/j.ergon.2017.05.016 https://doi.org/10.1016/j.ergon.2017.05.016 https://doi.org/10.1016/j.ergon.2017.05.016 https://doi.org/10.1007/978-3-030-19135-1_47 https://doi.org/10.1007/978-3-030-19135-1_47 https://doi.org/10.1007/978-3-030-19135-1_47 https://doi.org/10.1007/978-3-030-19135-1_47 https://doi.org/10.1007/978-3-030-19135-1_17 https://doi.org/10.1007/978-3-030-19135-1_17 https://doi.org/10.1007/978-3-030-19135-1_17 https://doi.org/10.1007/978-3-030-19135-1_17 https://doi.org/10.1007/978-3-030-19135-1_17 i. introduction ii. materials and methods a. design principles of vernacular batik and sustainable public transportation equipment b. kitsch c. sustainable design d. eco design e. recycle f. appropriate technology design g. affordance design h. metaphor design iii. results and discussions a. design value and applicability of batik b. applicability value to the public transportation equipment design c. integrating batik application possibilities to sustainable transportation d. inheriting of batik motifs, comprehension, and decomposing e. reinterpretation to contemporary public transportation equipment design concepts f. the applicability of vernacular indonesian technique and material iv. conclusion declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing muhammad zakiyullah romdlony a, fakih irsyadi b, * a school of electrical engineering, telkom university jalan telekomunikasi no. 1, bandung, 40257, indonesia b department of electrical engineering and informatics, vocational college, universitas gadjah mada jalan yacaranda, sekip unit iii, yogyakarta, 55281, indonesia received 1 july 2021; accepted 14 september 2021; published online 31 december 2021 abstract instructional media in control systems typically requires a real plant as an element to be controlled. however, this real plant, which is costly to be implemented, can be replaced by a virtual plant implemented in a computer and modelled in such a way that it resembles the behavior of a real plant. this kind of set-up is widely termed as hardware-in-the-loop (hil) simulation. hil simulation is an alternative way to reduce the development cost. a virtual plant is easy to adjust to represent various plants or processes that are widely used in industry. this paper proposes a simple hil simulation set-up designed as instructional media for design and testing a simple control system. the experimental result on dc motor control shows that hil simulation dynamical response is similar to the real hardware response with a small average error on measured transient response, represented in 0.5 seconds difference in settling time and 7.43 % difference in overshoot. this result shows the efficacy of our hil simulation set-up. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: control systems; hardware-in-the-loop (hil); instructional media. i. introduction the industrial revolution gives big challenges for engineering education institutions. the institutions have to provide students not only basic knowledge but also competency that is matched with the industrial needs. that approach is motivated by acknowledging the career readiness of students as an important learning outcome. the institutions have to provide various tools and facilities that are currently used in the industry. it can give a great experience for the student to learn in the same fashion as they will face when they work in the real workplace. however, it is not easy for most institutions to set up that ideal environment even if they have the budget for expensive equipment. they must provide enough space to place the equipment and cost for maintenance of the equipment. for some kinds of hardware, it might not be feasible to give access to students due to the risk of damaging expensive equipment. also, in special circumstances such as covid-19 pandemic, most education institutions restrict access to the laboratory due to health and safety regulations [1], thus students have lack of hands-on experience, even though the hardware is available. hardware-in-the-loop (hil) simulation can be used to be an alternative solution for these problems as it proposes the “lab-at-home” paradigm [2]. hil simulation uses virtual plants or processes that can be used to test the performance of developed control algorithms and also animated work principles of real machines or processes. the virtual plant/process is adjustable. it can be used to represent various plants or processes that are rapidly evolving. it can reduce time and cost for infrastructural development. it also makes the development process more realistic and safer. hil simulation in education is very common. there are several papers that propose the example of hil simulation application in some fields of education, such as in energy [3], automation, and robotics [4][5]. hil is also implemented in automotive control [6][7][8] and agricultural tractor [9]. there are various combination devices that are * corresponding author. tel: +62-274-6491302 e-mail address: fakih.irsyadi@ugm.ac.id https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.81-86 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.81-86&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m.z. romdlony and f. irsyadi / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 82 used in the hil simulation set up. some hil simulations use advanced and sophisticated devices to simulate complex systems. for less complex systems, a low-cost hardware combination can be opted. some set-ups use a low-cost, portable and popular microcontroller arduino as a controller [10][11][12] and a single-board computer such as raspberry pi [13]. most of that set-up uses a data communication channel to integrate the controller hardware into the simulation device. this scenario implies that the code of the controller cannot be directly used to control the real system. it needs some adjustment, especially in the input-output part. this paper proposes an alternative design of a simple and low-cost hil simulation set-up based on arduino. the hil simulation set-up consists of a computer as a simulation device, an arduino as the main controller, national instrumentation data acquisition systems (daq), and a simple resistorcapacitor (rc) circuit as signal conditioning for system integration. this set-up can be used as instructional media in engineering education or training institutions. in this paper, we present the application of such an hil simulation set-up for dc motor control. experiments are conducted to measure the performance of the hil simulation setup and to test a simple proportional integrator (pi) control on rotational speed control of a dc motor. ii. materials and methods this section discusses real-time simulation, the topology of hil simulation and details steps for the proposed hil simulation implementation. a. real-time simulation real-time simulation refers to a simulation that can execute the computation at the same rate as the actual physical system. based on the form of the components of real-time simulation, there are three types of real-time simulation, as shown in table 1. the first scheme consists of simulated control theory (software-based) and real plant/process. it is commonly called prototyping. the advantage of this scheme is that the engineer can directly implement continuous-time domain control theory without digitizing any process; most control theory is developed in a continuous-time domain. this scheme is also commonly used in online tuning because it uses real plants/processes to provide feedback signals for control algorithms. the second scheme is software-in-the-loop (sil) simulation. in this scheme, both components (controller and plant/process) are simulated on the simulation software. one of the most challenging phases to set up this scheme is modelling the plant/process. in several cases, it is not easy to get a mathematical model that represents the dynamical system, especially for the complex plant/process. this scheme is commonly used for education purposes, such as in control engineering courses. it also can be used to develop advanced control that is developed based on a model of plant/process. the last scheme is hil simulation. in this scheme, a real electronic control unit (ecu) is used to control a simulated plant/process modelled on the simulation software. one of the advantages of this scheme is that control development can be directly implemented on the real system with just small modifications. b. hardware-in-the-loop simulation hil simulation is one kind of real-time simulation. it was used more than 15 years ago. it was commonly used for complex systems in the industry. several works implementing hil can be found in [15][16][17]. two main reasons hil is suitable for various industries, are that it can decrease “time to market” and reduce the complexity of the real-time simulation. the purpose of the hil simulation is to develop and test the control algorithm implemented in real ecu to the simulated plant. some advantages of using hil simulation are as follows: • it can reduce development costs and time to market because it is not necessary to build a real plant or process. • some of complex systems need to do the development and testing of plants/processes in separate areas. the usage of hil simulation is very suitable because it is easy to modify or adapt the plant/process. • when the plant model is valid and accurate, the tuning of control variables can be done on simulation and the result can be implemented to the real plant with just a small modification. • the use of hil simulation can reduce the risk of damage to the overall system and environment during the development and testing process. • hil simulation can be used as instructional media to explain the working principles of a plant/process. the control structure of the hil simulation is presented in figure 1. the simulation consists of a controller implemented in the real hardware and plant/process simulated in simulation software. c. implementation process 1) plant modeling the first step for hil simulation realization is plant modelling. the aim of this step is to find mathematical equations that can represent the dynamic behavior of a real plant/process. those result equations would be implemented on simulation software to be a virtual plant on hil simulation. there are two methods that can be used to do plant/process modelling. in case of a lack of information of plant parameters or specifications, one typically uses a system identification method. this method uses a pair of data input and output to produce the model or mathematical equations of a table 1. various real-time simulation scheme [14] scheme set-up controller plants/processes 1 prototyping real real 2 sil simulated simulated 3 hil real simulated m.z. romdlony and f. irsyadi / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 83 real plant/process. in this paper, we demonstrate a simple experiment to derive a dc motor model from experimental data. the modelling process consists of several steps as follows. a) sensor calibration in this step, the measured data of the sensor is compared with the measured data of standard measurement instruments to validate the sensor. an optical encoder is used to measure the rotational speed of a dc motor and validated with an optical tachometer. table 2 shows the comparison between those two measurements for each given input voltage. the average error is 4.625 rpm which is relatively small. b) data gathering the system identification methods need a pair of input-output data to provide the modelling equations. in this case, the input signal is the input voltage of the dc motor and the output signal is the rotational speed of the dc motor. c) algorithm execution the recorded input and output data are submitted to the system identification software in order to get the model [18]. matlab system identification toolbox is used to find the transfer function, the correlation between the input voltage and rotary speed of the dc motor. based on the derivation of the modelling dc motor using system identification as reported in [16], the relation between rotational speed 𝜔(𝑡) and input voltage 𝑣(𝑡) of the dc motor, with assumes that the value of armature inductance is small compared to the armature resistance and it can be neglected, is approached into a first order system without zero. in our case, the resulting transfer function is 𝐺(𝑠) = ω (𝑠) 𝑉(𝑠) = 117.3 𝑠+1.14 (1) d) model validation after the mathematical model of a real plant is found, the next step is validating the model. in this step, both the real plant and the model are injected with the same input signal value. in this case, the input value is the input voltage of the dc motor in the range of 2 v until 11 v, which is in the linear operation range of the dc motor. figure 2 shows the result of a model validation experiment. the graph shows that the dynamic response of the model is close to the dynamic response of a real plant. the accuracy of the model is 87,95 % compared with real plant output for the same combination of input. this result implies that the mathematical modelling of a real plant is valid and it would be implemented as a virtual plant/process in the hil set-up. figure 2 shows that the highest error of the model is on the lower input voltage area. the reason is that the model generated by the system identification algorithm is a linear model that cannot capture the nonlinearity characteristic, i.e., a dead zone of the dc motor. 2) hardware-in-the-loop setup a) hardware design in this section, the proposed hil simulation set-up is discussed. the interconnection of each component in the set-up is shown in figure 3. the ecu of this system is an arduino microcontroller. this component is used for reading reference signal (that can be adjusted externally by a potentiometer) through table 2. optical encoder calibration voltage (volt) rotational speed – tachometer (rpm) rotational speed – optical encoder (rpm) error (rpm) 4 355 346 9 6 549 550 1 8 752 754 2 10 960 958 2 12 1182 1183 1 14 1460 1466 5 16 1662 1672 10 18 1849 1856 7 average error (rpm) 4.625 figure 2. graph of error modeling figure 1. structure of hardware-in-the-loop simulation m.z. romdlony and f. irsyadi / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 84 analog-to-digital converter (adc) pin, read the feedback from the simulated plant, execute the control algorithm, and provide the control signal to the simulated plant trough digital-to-analog converter (dac) and daq components. dac, in this set-up, is a simple rc circuit used to convert the control signal in the form of pulse-width modulation (pwm) to an analog value. in this set-up, daq is used to convert the analog signal from dac to data (serial communication protocol) to communicate with the simulated plant/process in simulation software. this component also converts the signal from the simulated plant/process to an analog signal as a feedback control signal. b) system realization this subsection discusses the implementation of hardware and software systems that are used in the experiment. the overall specifications of the system are as follows (table 3). the system realization is shown in figure 4 and figure 5. figure 4 shows the realization board of controller and signal processing discussed in figure 3. the interconnection of each component is wired by banana connectors. the hardware realization includes a power button, potentiometers for setting up the reference value and tuning up the control parameters, and a liquid-crystal display (lcd) as a simple display. the dc motor, as a real plant, is also mounted on the board. figure 5 shows the graphical user interface (gui) for interactively changing the parameters and displaying the time plot of the output signal. iii. results and discussions this section discusses the result of hil implementation for controlling a dc motor. an experiment is conducted to compare the performance of hil simulation and hardware implementation (prototyping, scheme 1 as in table 1). in this experiment, a simple pi control was implemented on the system to control the rotational speed of the dc motor. the pi control parameter was tuned on simulation software to provide various performances of the system. the experiment results are shown in table 4. the trend of dynamic response in hil simulation is similar to real hardware simulation. the average difference of the transient response between hil simulation and prototyping is around 0.5 seconds. the average difference of maximum overshoot between hil simulation and real hardware simulation is around 7.43 %. table 3. specification of the system hardware software personal computer arduino ide 1.8.8 arduino board uno r3 (atmega328p) ni labview 2017 64bit student version ni usb-6008 (daq), 8 inputs, 12 bit, 10k/s multifunction i/o matlab student version for system identification dc motor 24 v optical encoder (24 holes) figure 3. the proposed hardware-in-the-loop simulation interconnection figure 4. the proposed hardware-in-the-loop simulation set-up m.z. romdlony and f. irsyadi / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 85 iv. conclusion in this paper, a simple hil simulation set-up is successfully designed. it can be used to implement closed-loop control algorithms for development, testing, and educational purposes. experiment results show that the trend of dynamic response in hil simulation is similar to the one in real hardware implementation, with an average error of 0,5 seconds in measured transient response and 7.43 % in maximum overshoot. these findings show that the hil simulation set-up is able to represent the dynamic response of a real plant or process. in order to enhance the accessibility of the proposed hil simulation set-up for future development, we suggest the use of open-source simulation software, for example, sci-lab, for simulating the plant/process in the hil setup. acknowledgment this research was supported by the directorate of research and community service (ppm) of telkom university. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] k. gamage et.al., “online delivery of teaching and laboratory practices: continuity of university programmes during covid19 pandemic,” education science, 2020. table 4. performance comparison control parameters settling time (second) maximum overshoot (% rpm) proportional gain (𝑲𝒑) integral gain (𝑲𝒊) hil prototyping hil prototyping 0.0519089126 0.5326817035 2.3 2.8 24.70 30.50 0.0399423885 0.3308636903 2.6 3.8 24.20 31.80 0.0276177501 0.1744241952 4.4 4.2 21.60 30.50 average 3.1 3.6 23.50 30.93 difference between hil and prototyping 0.5 7.43 figure 5. graphical user interface developed in labview https://mev.lipi.go.id/ https://doi.org/10.3390/educsci10100291 https://doi.org/10.3390/educsci10100291 https://doi.org/10.3390/educsci10100291 m.z. romdlony and f. irsyadi / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 81-86 86 [2] s. usenmez et.al., “a new hardware-in-the-loop simulator for control engineering education,” in ieee global engineering education conference (educon), 2014. [3] a. gambier, “real-time control and hardware-in-the-loop simulation for educational purposes of wind energy systems,” sciencedirect, vol. 53, issue 2, pp. 17344–17349, 2020. [4] m. goubej and m. langmajer, “experience with use of hil simulators in control engineering course,” ifac-papersonline, vol. 53, no. 2, pp. 17308–17313, 2020. [5] o. l. osen, “on the use of hardware-in-the-loop for teaching automation engineering,” in ieee glob. eng. educ. conf. educon, vol. april-2019, pp. 1308–1315, 2019. [6] a. soltani et.al., “a hardware-in-the-loop facility for integrated vehicle dynamics control system design and validation,” 7th ifac symposium on mechatronic systems mechatronics, leicestershire, uk, 2016. [7] a. taksale et.al, “low cost hardware-in-loop for automotive application,” in international conference on industrial instrumentation and control (icic), india, 2015. [8] l. heidrich et.al., “hardware-in-the-loop test rig for integrated vehicle control systems,” 7th ifac symposium on advances in automotive control, tokyo, japan, 2013. [9] s. raikwar et.al., “hardware-in-the-loop test automation of embedded systems for agricultural tractors,” measurement, 133, pp. 271–280, 2019. [10] g. gambino et al., “a low-cost hil platform for testing professional refrigerators controllers,” ifac, vol. 19, no. 3. 2014. [11] i. tejado, j. serrano, e. pérez, d. torres, and b. m. vinagre, “low-cost hardware-in-the-loop testbed of a mobile robot to support learning in automatic control and robotics,” ifacpapers online, vol. 49, no. 6, pp. 242–247, 2016. [12] s. biswas, “real-time arduino based simulator enabled hardware-in-the-loop electric dc machine drive system,” in ieee region 10 humanitarian technology conference, dhaka, bangladesh, 2017. [13] j. sobota, “raspberry pi-based hil simulators for control education,” ifac papers online, pp.52-9 68–73, 2019. [14] r. isermann, j. schaffnit, and s. sinsel, “hardware-in-the-loop simulation for the design and testing of engine-control systems,” in ifac proc., vol. 31, no. 4, pp. 1–10, 1998. [15] x. wang, yin t, chen j, et al., “rapid design of motor dc speed control system based on matlab,” applied mechanics & materials, 743:168-171, 2015. [16] tang, wei-jie, zhen-tao liu, and qian wang. "dc motor speed control based on system identification and pid auto tuning," in chinese control conference (ccc), 36th chinese. ieee, 2017. [17] ismeal, godem a., karol kyslan, and viliam fedák. "dc motor identification based on recurrent neural networks," in mechatronics-mechatronika (me), 2014 16th international conference on. ieee, 2014. [18] l. ljung, “prediction error estimation methods,” circ. syst. signal process, 21, 11–21, 2002. https://doi.org/10.1109/educon.2014.6826058 https://doi.org/10.1109/educon.2014.6826058 https://doi.org/10.1109/educon.2014.6826058 https://doi.org/10.1016/j.ifacol.2020.12.2084 https://doi.org/10.1016/j.ifacol.2020.12.2084 https://doi.org/10.1016/j.ifacol.2020.12.2084 https://doi.org/10.1016/j.ifacol.2020.12.1814 https://doi.org/10.1016/j.ifacol.2020.12.1814 https://doi.org/10.1016/j.ifacol.2020.12.1814 https://doi.org/10.1109/educon.2019.8725050 https://doi.org/10.1109/educon.2019.8725050 https://doi.org/10.1109/educon.2019.8725050 https://doi.org/10.1016/j.ifacol.2016.10.507 https://doi.org/10.1016/j.ifacol.2016.10.507 https://doi.org/10.1016/j.ifacol.2016.10.507 https://doi.org/10.1016/j.ifacol.2016.10.507 https://doi.org/10.1109/iic.2015.7150913 https://doi.org/10.1109/iic.2015.7150913 https://doi.org/10.1109/iic.2015.7150913 https://doi.org/10.3182/20130904-4-jp-2042.00027 https://doi.org/10.3182/20130904-4-jp-2042.00027 https://doi.org/10.3182/20130904-4-jp-2042.00027 https://doi.org/10.1016/j.measurement.2018.10.014 https://doi.org/10.1016/j.measurement.2018.10.014 https://doi.org/10.1016/j.measurement.2018.10.014 https://doi.org/10.3182/20140824-6-za-1003.02414 https://doi.org/10.3182/20140824-6-za-1003.02414 https://doi.org/10.3182/20140824-6-za-1003.02414 https://doi.org/10.1016/j.ifacol.2016.07.184 https://doi.org/10.1016/j.ifacol.2016.07.184 https://doi.org/10.1016/j.ifacol.2016.07.184 https://doi.org/10.1016/j.ifacol.2016.07.184 https://doi.org/10.1109/r10-htc.2017.8289082 https://doi.org/10.1109/r10-htc.2017.8289082 https://doi.org/10.1109/r10-htc.2017.8289082 https://doi.org/10.1109/r10-htc.2017.8289082 https://doi.org/10.1016/j.ifacol.2019.08.126 https://doi.org/10.1016/j.ifacol.2019.08.126 https://doi.org/10.1016/s0967-0661(98)00205-6 https://doi.org/10.1016/s0967-0661(98)00205-6 https://doi.org/10.1016/s0967-0661(98)00205-6 https://doi.org/10.4028/www.scientific.net/amm.743.168 https://doi.org/10.4028/www.scientific.net/amm.743.168 https://doi.org/10.4028/www.scientific.net/amm.743.168 https://doi.org/10.23919/chicc.2017.8028376 https://doi.org/10.23919/chicc.2017.8028376 https://doi.org/10.23919/chicc.2017.8028376 https://doi.org/10.1109/mechatronika.2014.7018347 https://doi.org/10.1109/mechatronika.2014.7018347 https://doi.org/10.1109/mechatronika.2014.7018347 https://doi.org/10.1109/mechatronika.2014.7018347 https://doi.org/10.1007/bf01211648 https://doi.org/10.1007/bf01211648 introduction ii. materials and methods a. real-time simulation b. hardware-in-the-loop simulation c. implementation process 1) plant modeling sensor calibration b) data gathering c) algorithm execution d) model validation 2) hardware-in-the-loop setup a) hardware design system realization iii. results and discussions iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2021.v12.87-94 2088-6985 / 2087-3379 ©2021 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 1 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. domestic component level analysis for multipurpose autonomous robot vita susanti a, *, henny sudibyo a, ridwan arief subekti a, ghalya pikra a, rakhmad indra pramana a, andri joko purwanto a, merry indahsari devi a, agus fanar syukri b, roni permana saputra a, c a research centre for electrical power and mechatronics – indonesian institute of sciences komp lipi jl. sangkuriang, building 20, 2nd floor, bandung, west java, 40135, indonesia b research center for policy and management of science, technology, and innovation– indonesian institute of sciences jl. jend gatot subroto no. 10, south jakarta, 12710 indonesia c robot intelligence laboratory, dyson school of design engineering, imperial college london south kensington campus, london sw7 2az, united kingdom received 27 august 2021; accepted 22 october 2021; published online 31 december 2021 abstract multipurpose autonomous robot technology has been developed to assist transportation sectors or the current emergency as the covid-19 pandemic. a practical issue in the robotic industry concerns the domestic content in commodities, services, and a combination of goods and services commonly determined as domestic component level (dcl). to be considered a standardized national product, a product's dcl must surpass a certain level of local content composition. this research aims to investigate the dcl of a developed multipurpose autonomous robot in indonesia called rom20. the research was initiated by interviewing specialists in dcl calculation and robotics research to perform dcl analysis on rom20. the next step was breaking down the rom20 components into a second layer component, in which the amount of domestic component and overseas components can be derived. finally, the rom20 dcl value was calculated by dividing the cost of domestic components by the total cost of domestic and overseas components. as a digital product, the rom20 dcl calculation result showed that the manufacturing aspect is 70 %, and the development aspect is 30 %. the overall rom20 dcl value has been calculated as 52.23 %, which surpasses the national standard threshold at 40 % dcl value. therefore, rom20 can be considered a high-value standardized national product, impacting the competitiveness of local products and the fast-growing medical device industry in indonesia. ©2021 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: domestic component level; modular system; multipurpose autonomous robot; rom20. i. introduction indonesian government is determined to encourage optimization on the domestic component level (dcl) to increase the productivity and competitiveness of the national industry during world trade conditions that tend to be closed. dcl is the amount of content originating from within the country, particularly indonesia, in goods, services, and combinations of both. the benefits of implementing dcl are creating new employment opportunities, adding income tax for products made in indonesia, creating a supply chain with a good ecosystem, and creating equality between local and international brand players. each country will protect the results of its technological products from increasing the value of profits as a source of state income. on the other hand, the number of imported products will undoubtedly increase the dependence on other countries. thus, protecting domestic products is such a nationalist act in asia and africa [1][2]. moreover, nearly 90 % of countries with abundant natural resources have local content policies and requirements [3][4][5]. therefore, local content policies in various countries will increase employment growth, incubation, upstream industry development, and sustainable economic growth towards higher levels of welfare [6][7][8]. in * corresponding author. tel: +6281952942794; fax: +62-222503055 e-mail address: vitasusanti@gmail.com https://dx.doi.org/10.14203/j.mev.2021.v12.87-94 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2021.v12.87-94 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.87-94&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 88 addition, the local content policy will also increase the superior human resources in the said country [9][10]. indonesian domestic products continue to be developed to reduce the value of imported components. domestic components used raw materials, design, and engineering that contain manufacturing, fabrication, assembly, and completion of work originating from and implementing in the country. the domestic component of services is using services up to the end of the workforce by utilizing manpower including experts, work tools including software, and supporting facilities originating from and implementing in the country. determination of domestic components based on the following criteria 1) direct materials were based on their country of origin, 2) work tools/work facilities were based on their ownership and country of origin, and 3) workers were based on their nationality. several studies have been made on the calculation of dcl for indonesian domestic products, as stated by febijanto et al. [11], assessed the dcl of the salt industry. increasing nacl content was analyzed on a cost basis, while it is evaluated on a process basis for salt production. the analysis was carried out at the indonesian salt center in two stages: pilot project and implementation. other studies on domestic product dcl are also carried out on the planning and development of geothermal power plants/pltp [12], biogas power plants/pltbg [13], and the national shipping industry [14]. robotic technology is not only in the industrial sector but also in daily life. robotic technology has evolved so that robots can now have cognitive, manipulation, and interaction abilities. electric vehicles or autonomous vehicles are an example of the development of robotic technology and autonomous systems. indonesia is still lagging behind other countries in robotic technology or autonomous vehicles. however, to support technological developments and take sides with domestic products, the government issued a policy that has been regulated in presidential regulation no. 55 of 2019 concerning the acceleration of the battery electric vehicle program for road transportation [15]. the government hopes that the transportation in the new capital will use autonomous vehicles. rom20 is one of the products that implement robotic technology and can also be called an unmanned vehicle because it can move independently. autonomous technology based on sae international has six levels of self-mobility [16]. in figure 1 [17], levels 0 and 1 do not have autonomous technology, where driver assistance has a significant role. while level 2 autonomous technology can move on its own, although partially, meaning that the car can run on its own while the driver still has to be ready if the vehicle faces certain road conditions. level 3 autonomous technology described where the driver can let the car run alone and does not need to pay attention to road conditions. level 4 autonomous technology, the driver, is much freer to let the car run independently. the last is level 5 autonomous technology, and the driver has the same ability at level 4. the difference is that there are no specific location restrictions and no intervention from the driver. in december 2019, there was a coronavirus disease 19 (covid-19) outbreak in wuhan, china. and who declared it a global pandemic on march 11, 2020. the virus that causes covid-19 is severe acute respiratory syndrome 2 (sars-cov-2) [18]. coronavirus is a single-stranded rna (ribonucleic acid) virus protected by a nucleocapsid protein [19]. the structure of the coronavirus is composed of spike proteins and is surrounded by a membrane and glycoproteins. this spike protein is one of the main antigens and plays a role in attaching and entering viruses into the host (interaction of spike proteins with host cell receptors). thus, this virus attacks the respiratory system. for mild cases, the symptoms are just like the flu. but there are some more severe cases such as pneumonia, middle-east respiratory syndrome (mers), severe acute respiratory syndrome (sars), and even death. the spread of covid-19 through droplets coughing or figure 1. level of autonomous driving [17] v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 89 sneezing with covid-19 sufferers then spreads into the air and lands on surrounding objects. if a healthy person inhales air or touches an object affected by the droplet, then his hand accidentally touches his nose or mouth, the healthy person will be infected with covid-19. due to its massive spread, many covid-19 patients with moderate and severe symptoms need to be hospitalized. therefore, robots that can operate autonomously are required to assist and protect health workers from being infected with covid-19 [20]. several developed assisting robots such are disinfection robots using uvc, robots that spray disinfection liquids, and robots that deliver and warm food for covid-19 patients. uvc light with a 200 to 280 nm wavelength can inactivate various pathogens, including the sarscov virus. based on the research results basin et al., uvc with a wavelength of 254 nm can efficiently inactivate sars-cov-2 at a dose of 3.7 mj/cm2 without any signs of viral replication [21]. in addition to the uvc wavelength as given by david welch et al. [22], the use of far-uvc with a wavelength of 207 to 222 nm can inactivate pathogens (h1n1 influenza virus) > 95 % present in aerosols at a very low dose of 2 mj/m2. this far-uvc wavelength is also safer because it is not carcinogenic. furthermore, this light cannot penetrate the skin of mammals but can penetrate pathogens whose dimensions are microscopic and inactivate them [23]. therefore, far-uvc 222 nm is a safe alternative to replace conventional uvc with a wavelength of 254 nm. during the current pandemic, cleaning and disinfection steps are critical to reducing the spread of pathogens. these pathogens often stick in hidden places and are touched by many people, such as doorknobs, elevator buttons, electric buttons, etc. [24]. based on several research results, disinfection of object surfaces with disinfectant spray using hydrochloride and hydrogen peroxide vapor has a significant impact on controlling the spread of pathogens [25][26]. another research on sprayer robots by george adamides et al. [27] discusses spraying robots controlled remotely through a reality-based interaction interface. another thing that needs to be considered during a pandemic is to reduce physical human interaction so that robots can assist in delivering goods and food. calderon et al. [28] have researched health services by increasing the productivity of logistics activities in hospitals using a mobile robot platform. putri et al. [29] have conducted research using a dht22 temperature sensor and fuzzy logic algorithm to control food's warmth automatically to keep the food warm. lucas grasse et al. [30] have researched food delivery robots using voice recognition, mapping and navigation methods, and a depth camera to move according to predetermined coordinate points. rom20 is a multipurpose autonomous robot produced by the indonesian institute of science (lipi), as a researcher's contribution in dealing with the covid-19 outbreak. this paper discusses the dcl calculation of rom20 and briefly describes rom20 technology, rom20 components, and dcl calculation. in addition, several related regulations regarding dcl analysis are also discussed in this paper. ii. methods the method used in this study is as shown in figure 2, where the data used is secondary data. the data were obtained from government regulations, journals, and proceedings concerning dcl, autonomous robot development, and medical robots. in addition to the literature review, the data were also combined with the interviews with specialists in management and calculation, notable consultants from surveyor indonesia and researchers from the research centre for electrical power and mechatronics, who built a prototype of the multipurpose autonomous robot (rom20). in this study, the dcl of the multipurpose autonomous robot (rom20) has been calculated so that the component data obtained from the researchers are then derived and analyzed. equation (1) [11] were used to perform the dcl calculation. % 𝐷𝐷𝐷 = 𝐷𝐷 𝑐𝑐𝑐𝑐 𝐷𝐷 𝑐𝑐𝑐𝑐 + 𝑂𝐷 𝑐𝑐𝑐𝑐 𝑥 100 % (1) domestic components (dc) are goods/services produced domestically, and overseas components (oc) are goods/services manufactured abroad. therefore, using equation (1), the percentage of dcl rom20 can be determined. the process to calculate dcl is shown in figure 3. the first thing that needs to be done is breaking down all components for each subsystem and then figure 2. research methodology flowchart v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 90 set a price for each component. if rom20 is the first layer, its components are the second layer. the next step is to determine the percentage for each component's second dcl layer (dcl 2) that make up rom20. each component in dcl 2 must be verified by referring to the domestic goods and services inventory book issued by the indonesian ministry of industry. for example, one of the mechanical components on the platform is a metal produced by krakatau steel, an indonesian steel factory. it means that this product is domestically produced to determine the dcl 2 weight of 60 %. at the same time, the determination for components made abroad has a dcl 2 weight of 0 %. after determining the percentage of dcl 2 for each component, the cost of the domestic and foreign components can be calculated. henceforth, the calculation of dcl for rom20 refers to equation (1). the fundamental difference between this paper and the previous one is that this one will break down all of the rom20 second layer. furthermore, because the rom20 is a digital product, the dcl calculation is split into 70 % manufacturing and 30 % development. iii. results and discussions multipurpose autonomous robot (rom20) consists of three modular subsystems that can be removed as needed, where this modular subsystem is placed on a mobile robot platform. figure 4 shows the modular concept of the mobile robot platform (a), if the platform is combined with a uvc lamp modular (b), it will become a uv robot subsystem (ruv). furthermore, if combined with a disinfectant spraying modular (c), it will become a disinfectant spraying robot subsystem (rpc). finally, when combined with a food warmer modular (d), it will become a food warmer robot (rpm) [31]. the mobile robot platform consists of a frame, motor, wheels connected to the driver, and the driver is connected to the control panel. the platform frame is closed with the body and chassis, and clamps are attached to the body to figure 3. dcl calculation flowchart figure 4. modular concept of rom20 [31] v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 91 correctly/precisely attach the modular subsystem. this robot is equipped with multi-directional wheels that can move freely, namely back and forth, or even move sideways. in addition, ultrasonic/infrared sensors are installed on this robot to detect existing obstacles to anticipate movements when working in autonomous mode when performing tasks indoors. figure 5 shows the rom20 prototype where each subsystem is installed on the mobile platform [32]. rom20 moves automatically but can be controlled using a gadget with the line follower route stored in the system and can also facilitate communication using bluetooth and wifi with a maximum distance of 20 meters. a. uvc subsystem in the uvc subsystem, a uv lamp with a wavelength between 200 to 280 nm is installed, functioning as inactivation of pathogens. four pieces of uvc lamps are installed in a circle with a 360degree range that can illuminate the entire room to the maximum. each lamp can be turned on or off separately through the application on the gadget, and the lights will automatically turn off if there is a movement of living things in the room detected. b. disinfectant spray subsystem the disinfectant spray subsystem is equipped with a tube to store the disinfectant liquid, a mist maker that creates mist from the disinfectant liquid, a blower to push the mist, and six nozzles to spray mist. these nozzles can rotate continuously so that the disinfectant liquid spreads evenly throughout the entire room. in addition, there is an indicator of the height of the disinfectant. so that the volume of disinfectant in the tube will always be monitored, the indicator will activate an alarm when the disinfectant level has reached the minimum level. c. food warmer subsystem in the food warmer subsystem, a compartment is equipped with a heating panel and a temperature sensor to regulate the temperature and humidity. the maximum temperature that can be set through the application on the gadget is 60 °c. d. dcl calculation for rom20 according to figure 3, various procedures are required to calculate rom20 dcl, including breaking down all component subsystems as given in table 1. (a) (b) (c) figure 5. rom20 prototype [32]: (a) uvc robot; (b) disinfectant spray robot; and (c) food warmer robot table 1. rom20 components items items items items platform ads1115 lamp socket terminal food warmer subsystem mechanic stepdown 24 vdc to 5 vdc uv socket microcontroller mecanum wheel stepdown 48 vdc to 24 vdc disinfectant spray subsystem stepdown 24 vdc to 5 vdc motor holder fuse blade microcontroller inverter 24 vdc to 220 vac stepper driver fuse blade 5 a & 20 a relay 5 vdc 1 channel relay module 30 a battery emergency stop stepdown 24 vdc to 5 vdc fuse blade holder body heat shrink tube stepup 24 vdc to 36 vdc fuse blade microcontroller key switch relay module 30 a showcase food warmer mosfet irf520 accessories mist maker 6 holes 7 segment led tube display ir sensor uvc subsystem cooling fan 12 cm heating element 24 vdc current & voltage sensor microcontroller cooling fan 8 cm temperature & humidity sensor ultrasonic sensor relay 8 channel solid state power socket indicator lamp 24 vdc esp32-cam stepdown 24 to 5 vdc mist socket bluetooth hc-05 inverter 24 to 220 vac pot lcd usart 5 inch uv sterilizer lamp v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 92 furthermore, tables 2 to 5 determine the second layer on the components of the subsystem and the magnitude of the weight of domestic and overseas components. therefore, the amount of dcl will be completely determined after this phase. equation (1) was used as a guide to emphasize dcl calculations, which is more focused on manufacturing, the country of origin of the components used, and the workers' origins. furthermore, because rom20 is a digital product, the dcl calculation is split into two halves, with the manufacturing aspect weight being 70 % and the development aspect being 30 %. table 2 shows the weight of the dc and oc for each component in the platform section. the inventory book of goods and services of domestic production issued by the indonesian ministry of industry can be referred to determine the weights of dc and oc. the mechanical component consists of several components, one of which is metal. this metal raw material is produced by krakatau steel, a state-owned company that is domestically produced. because metal is one of the components that make up the mechanic component, the weight for dc is 60 %, and the weight for oc is 40 %. resin is one of the body-forming materials for body components. again, this material is produced domestically, so the body components are given a dc weight of 60 % and 40 % oc. for components manufactured abroad, the weight for dc is 0 %, and oc is 100 %. table 3 shows the weight of dc and oc for the components of the uvc subsystem. the weight for dc is shown 0 %, and oc is 100 % because all components in the subsystem were foreign production. in addition to table 4, most of the components that make up the disinfectant spray subsystem are foreign products, so the dc weight is 0 %, and the oc is 100 %. on the other hand, domestic production is only on pot components, so that the weight of dc is 60 % and oc is 40 %. table 5 shows all components of the food warmer subsystem which use the foreign product so that the dc weight is 0 % and the oc is 100 %. table 6 shows the result of the dcl calculation for each subsystem, where the cost of the domestic component is divided by the total cost of the domestic and overseas components. the dcl value for these subsystems is 0 % because all uvc and food warmer subsystems components are imported from abroad. however, even though the dcl is 0 %, to calculate the total dcl value, there is still the overseas component (y2 and y4) cost from the uvc and food warmer subsystems as the divisor value. therefore, the total dcl is increasing. overall, the dcl value of rom20 is 31.76 %. table 2. dcl 2 weight of rom20 platform items domestic component overseas component mechanic 60 % 40 % mecanum wheel 0 % 100 % motor 0 % 100 % stepper driver 0 % 100 % battery 0 % 100 % body 60 % 40 % microcontroller 0 % 100 % mosfet irf520 0 % 100 % ir sensor 0 % 100 % current & voltage sensor 0 % 100 % ultrasonic sensor 0 % 100 % esp32-cam 0 % 100 % bluetooth hc-05 0 % 100 % lcd usart 5 inch 0 % 100 % ads1115 0 % 100 % stepdown 24 v to 5 v 0 % 100 % stepdown 48 v to 24 v 0 % 100 % holder fuse blade 0 % 100 % fuse blade 5 a & 20 a 0 % 100 % emergency stop 0 % 100 % heat shrink tube 0 % 100 % key switch 0 % 100 % accessories 70 % 30% table 3. dcl 2 weight of uvc subsystem items domestic component overseas component microcontroller 0 % 100 % relay 8 channel solid state 0 % 100 % stepdown 24 to 5 v 0 % 100 % inverter 24 to 220 vac 0 % 100 % uv sterilizer lamp 0 % 100 % lamp socket terminal 0 % 100 % uv socket 0 % 100 % table 4. dcl 2 weight of disinfectant spray subsystem items domestic component overseas component microcontroller 0 % 100 % relay 5 v 1 channel 0 % 100 % stepdown 24 v to 5 v 0 % 100 % stepup 24 v to 36 v 0 % 100 % relay module 30 a 0 % 100 % mist maker 6 holes 0 % 100 % cooling fan 12 cm 0 % 100 % cooling fan 8 cm 0 % 100 % power socket 0 % 100 % mist socket 0 % 100 % pot 60 % 40 % table 5. dcl 2 weight of food warmer subsystem items domestic component overseas component microcontroller 0 % 100 % stepdown 24 v to 5 v 0 % 100 % inverter 24 vdc to 220 vac 0 % 100 % relay module 30 a 0 % 100 % fuse blade holder 0 % 100 % fuse blade 0 % 100 % showcase food warmer 0 % 100 % 7 segment led tube display 0 % 100 % heating element 24 v 0 % 100 % temperature & humidity sensor 0 % 100 % indicator lamp 24 v 0 % 100 % v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 93 based on regulation of industrial ministry no. 22, 2020 [33], rom20 is categorized as a digital product because its primary function is to process binary numbers. the product's characteristics have new technology and a microcontroller to process input. this digital product's manufacturing aspect is 70 % and 30 % for the development aspect. the manufacturing dcl of rom20 is found to be 31.76 % based on the calculation using equation (1). because rom20 is included in the digital product category, the dcl weight for the manufacturing aspect is 70 %, so the rom20 dcl for the manufacturing aspect is 22.23 %. on the other hand, the dcl weight for the development aspect is 30 %, so the total rom20 dcl is 52.23 %. more details of the calculation result can be seen in table 7. the dcl with a development aspect of 30 % requires research and development documents in bahasa. this documents aims to make the workforce in the research and development division able to create or to make a modification based on the research and development documents that have been made. the research documents include research blueprints, sops/activity manuals, designs (products, mechanics, mock-ups), user interface development, source code and compilers, and patents. a product can become a national product, and the condition is that the dcl is at least 40 %. based on the strategic plan of the ministry of industry for 2020 2024, to improve the ability of domestic industries with performance indicators, the target of dcl in 2020 should be 49 % and will continue to increase until 2024 by 53 % [34]. therefore, rom20 qualifies as a national product because its dcl exceeds the minimum required limit of 40 %. the analysis of rom20 dcl shows that the costbased analysis was very dependent on the origin of the equipment components. it follows what was stated by febijanto et al. [11]. in comparison, process-based analysis depends on the origin of the workforce, work tools, and material owners. for example, suppose the dcl value of an industry is to be high. the raw materials must be produced domestically as much as possible with the labor and work equipment belonging to the domestic industry. increasing the dcl value of rom20 is very important because it will affect the costs associated with the production and competitiveness of the rom20 product. based on the results of previous studies, it is known that there is a relationship between the value of dcl with a reduction in overhead costs, investment, and operational costs [12][13]. furthermore, increasing the value of dcl in the national industry will increase competitiveness against production from abroad [14]. efforts to increase this value also help influence the domestic multipurpose autonomous robot industry and grow new businesses to reduce component costs and overhead. iv. conclusion rom20 is a researcher's contribution to combating the covid-19 epidemic with three functions: uv robot, disinfectant spraying robot, and food warming robot. all of the components in rom20 were derived to determine their percentage weight on the second layer, allowing the dcl value to be calculated from the breakdown results. therefore, rom20 is included in the digital product category. dcl calculation for a digital product consists of two aspects: the manufacturing aspect with a weight of 70 % and the development aspect with a weight of 30 %. based on the calculation results, the total rom20 dcl is 52.23 %. therefore, rom20 can be considered a national product because its dcl value surpasses the minimum dcl value at 40 %. consequently, it impacts the competitiveness against overseas products and induces the expansion of the national medical device sector. acknowledgment the authors would like to thank mr. hendri maja saputra, mr. catur hilman adritya h. b. baskoro, and mr. midriem mirdanies for providing rom20 data. in addition, the authors would also like to gratitude mr. table 6. domestic component level for each section section domestic component cost overseas component cost domestic component level (dcl) (1) (2) (3) (4) = (2)/((2)+(3)) platform x1 y1 34.26 % uvc subsystem 0 y2 0 % disinfectant spray subsystem x3 y3 1.50 % food warmer subsystem 0 y4 0 % total x1+x3 y1+y2+y3+y4 31.76 % table 7. dcl calculation refers to digital product aspect rom20 dcl digital product determination value domestic component level (dcl) (1) (2) (3) (4)= (2)x(3) manufacturing 31.76 % 70% 22.23% development 100% 30% 30.00% total rom20 dcl 52.23% v. susanti et al. / journal of mechatronics, electrical power, and vehicular technology 12 (2021) 87-94 94 sarjuni at surveyor indonesia for the consult and supervision on calculating rom20 dcl. declarations author contribution v. susanti is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. conflict of interest the authors declare no conflict of interest. additional information reprints and permission information is available at https://mev.lipi.go.id/. publisher’s note: research centre for electrical power and mechatronics indonesian institute of sciences remains neutral with regard to jurisdictional claims and institutional affiliations. references [1] s. andreasson, “varieties of resource nationalism in subsaharan africa’s energy and minerals markets,” extr. ind. soc., vol. 2, no. 1, pp. 310–319, 2015. [2] j. d. wilson, “understanding resource nationalism : economic dynamics and political institutions political institutions,” contemp. polit., vol. 21, no. 4, pp. 399–416, 2015. [3] i. ramdoo, “unpacking local content requirements in the extractive sector: what implications for the global trade and investment frameworks?,” geneva, 2015. [4] r. dobbs, j. oppenheim, a. kendall, f. thompson, m. bratt, and f. van der marel, “reverse the curse : maximizing the potential of resource-driven economies,” 2013. [5] j. s. ovadia, “local content policies and petro-development in sub-saharan africa : a comparative analysis,” resour. policy, vol. 49, pp. 20–30, 2016. [6] c. kwon and b. g. chun, “local content requirement under vertical,” rev. dev. econ., vol. 13, no. 1, pp. 111–124, 2009. [7] f. m. veloso, “understanding local content decisions : economic analysis and an application to the automotive industry,” j. reg. sci., vol. 46, no. 4, pp. 747–772, 2006. [8] a. niran and a. abd, “the role of local content policy in local value creation in nigeria’s oil industry : a structural equation modeling ( sem ) approach,” resour. policy, vol. 49, pp. 61–73, 2016. [9] j. u. monday, “local content policy , human capital development and sustainable business performance in the nigerian oil and gas industry,” j. manag. sustain., vol. 5, no. 1, pp. 75–83, 2015. [10] s. lange and a. kinyondo, “resource nationalism and local content in tanzania : experiences from mining and consequences for the petroleum sector,” extr. ind. soc., vol. 3, no. 4, pp. 1095–1104, 2016. [11] i. febijanto et al., “domestic component level assessment for a salt factory and a salt production,” maj. ilm. pengkaj. ind., vol. 15, no. 1, pp. 50–58, 2021. [12] a. windaru and a. h. budiman, “cost generation analysis of small scale geothermal power plant,” j. energi dan lingkung., vol. 13, no. 1, pp. 47–52, 2017. [13] b. sucahyo, d. l. h, r. ridlo, t. p. r, and e. r. s, “kajian teknologi pemanfaatan biogas pome (palm oil mill effluent) ke boiler,” maj. ilm. pengkaj. ind., vol. 13, no. 1, pp. 43–54, 2019. [14] t. hidayat and b. ma’ruf, “improvement analysis of component local content on domestic new building,” wave j. ilm. teknol. marit., vol. 10, no. 2, pp. 61–66, 2016. [15] ministry of state secretariat, presidential regulation no. 55 of 2019 concerning the acceleration of the battery electric vehicle program for road transportation. indonesia, 2019. [16] s. asadi, b. madjid, m. asadi, and t. oliver, “autonomous vehicles : challenges, opportunities, and future implications for transportation policies,” j. mod. transp., vol. 24, no. 4, pp. 284–303, 2016. [17] m. hirz and b. walzel, “sensor and object recognition technologies for self-driving cars,” comput. des. appl., vol. 15, no. 4, pp. 501–508, 2018. [18] j. h. j. a. yoganandhan, g. rajesh kanna, s. d. subhash, “retrospective and prospective application of robots and artificial intelligence in global pandemic and epidemic diseases,” vacunas, vol. 22, no. 2, pp. 98–105, 2021. [19] s. boopathi, a. b. poma, and p. kolandaivel, “novel 2019 coronavirus structure , mechanism of action, antiviral drug promises and rule out against its treatment,” j. biomol. struct. dyn., vol. 39, no. 9, pp. 3409–3418, 2021. [20] y. shen et al., “robots under covid-19 pandemic : a comprehensive survey,” ieee access, vol. 9, pp. 1590–1615, 2021. [21] m. biasin et al., “uv-c irradiation is highly effective in inactivating sars-cov-2 replication,” sci. rep., vol. 11, no. 1, p. 6260, 2021. [22] d. welch et al., “far-uvc light : a new tool to control the spread of airborne-mediated microbial diseases,” sci. rep., vol. 8, no. 1, p. 2752, 2018. [23] m. buonanno, d. welch, i. sh, and d. j. brenner, “far-uvc light (222 nm) efficiently and safely inactivates airborne human coronaviruses,” sci. rep., vol. 10, no. 1, p. 10285, 2020. [24] b. ramalingam et al., “a human support robot for the cleaning and maintenance of door handles using a deep-learning,” sensors, vol. 20, no. 12: 3543, 2020. [25] c. j. donskey, “does improving surface cleaning and disinfection reduce health care-associated infections?,” am. j. infect. control, vol. 41, no. 5, pp. s12–s19, 2013. [26] c. l. passaretti et al., “an evaluation of environmental decontamination with hydrogen peroxide vapor for reducing the risk of patient acquisition of multidrug-resistant organisms,” clin. infect. dis., vol. 56, no. 1, pp. 27–35, 2013. [27] g. adamides, c. katsanos, g. christou, m. xenos, g. papadavid, and t. hadzilacos, “user interface considerations for telerobotics : the case of an agricultural robot sprayer,” second int. conf. remote sens. geoinf. environ., vol. 9229, 2014. [28] c. a. a. calderon, e. r. mohan, and b. s. ng, “development of a hospital mobile platform for logistics tasks,” digit. commun. networks, vol. 1, no. 2, pp. 102–111, 2015. [29] a. r. putri and p. n. rahayu, “food warmer system based on dht-22,” j. adv. res. electr. eng., vol. 4, no. 1, pp. 56–63, 2020. [30] l. grasse, s. j. boutros, and m. s. tata, “speech interaction to control a hands-free delivery robot for high-risk health care scenarios,” front. robot. ai, vol. 8, p. 40, 2021. [31] h. m. saputra et al., “robot otonom multiguna,” p00202006900, 2020. [32] c. h. a. h. b. baskoro, h. m. saputra, m. mirdanies, v. susanti, m. f. radzi, and r. i. a. aziz, “an autonomous mobile robot platform for medical purpose,” in 2020 international conference on sustainable energy engineering and application (icseea), 2020, pp. 41–44. [33] ministry of industry indonesia, regulation of the minister of industry of the republic of indonesia number 22 of 2020 concerning provisions and procedures for calculation of the value of domestic component levels for electronic and telematics products. indonesia, 2020. [34] ministry of industry indonesia, “strategic plan for 2020 to 2024 ministry of industry,” jakarta, 2020. https://mev.lipi.go.id/ http://dx.doi.org/10.1016/j.exis.2015.01.004 http://dx.doi.org/10.1016/j.exis.2015.01.004 http://dx.doi.org/10.1016/j.exis.2015.01.004 https://doi.org/10.1080/13569775.2015.1013293 https://doi.org/10.1080/13569775.2015.1013293 https://doi.org/10.1080/13569775.2015.1013293 http://dx.doi.org/10.13140/rg.2.1.4943.5129 http://dx.doi.org/10.13140/rg.2.1.4943.5129 http://dx.doi.org/10.13140/rg.2.1.4943.5129 https://www.mckinsey.com/industries/metals-and-mining/our-insights/reverse-the-curse-maximizing-the-potential-of-resource-driven-economies https://www.mckinsey.com/industries/metals-and-mining/our-insights/reverse-the-curse-maximizing-the-potential-of-resource-driven-economies https://www.mckinsey.com/industries/metals-and-mining/our-insights/reverse-the-curse-maximizing-the-potential-of-resource-driven-economies http://dx.doi.org/10.1016/j.resourpol.2016.04.003 http://dx.doi.org/10.1016/j.resourpol.2016.04.003 http://dx.doi.org/10.1016/j.resourpol.2016.04.003 https://dx.doi.org/10.1111/j.1467-9361.2008.00462.x https://dx.doi.org/10.1111/j.1467-9361.2008.00462.x https://dx.doi.org/10.1111/j.1467-9787.2006.00476.x https://dx.doi.org/10.1111/j.1467-9787.2006.00476.x https://dx.doi.org/10.1111/j.1467-9787.2006.00476.x https://doi.org/10.1016/j.resourpol.2016.04.006 https://doi.org/10.1016/j.resourpol.2016.04.006 https://doi.org/10.1016/j.resourpol.2016.04.006 https://doi.org/10.1016/j.resourpol.2016.04.006 https://doi.org/10.5539/jms.v5n1p75 https://doi.org/10.5539/jms.v5n1p75 https://doi.org/10.5539/jms.v5n1p75 https://doi.org/10.5539/jms.v5n1p75 http://dx.doi.org/10.1016/j.exis.2016.09.006 http://dx.doi.org/10.1016/j.exis.2016.09.006 http://dx.doi.org/10.1016/j.exis.2016.09.006 http://dx.doi.org/10.1016/j.exis.2016.09.006 https://doi.org/10.29122/mipi.v15i1.4746 https://doi.org/10.29122/mipi.v15i1.4746 https://doi.org/10.29122/mipi.v15i1.4746 https://doi.org/10.29122/elk.v13i1.4259 https://doi.org/10.29122/elk.v13i1.4259 https://doi.org/10.29122/elk.v13i1.4259 https://doi.org/10.29122/mipi.v13i1.3219 https://doi.org/10.29122/mipi.v13i1.3219 https://doi.org/10.29122/mipi.v13i1.3219 https://doi.org/10.29122/jurnalwave.v10i2.2641 https://doi.org/10.29122/jurnalwave.v10i2.2641 https://doi.org/10.29122/jurnalwave.v10i2.2641 https://jdih.bumn.go.id/lihat/perpres%20nomor%2055%20tahun%202019 https://jdih.bumn.go.id/lihat/perpres%20nomor%2055%20tahun%202019 https://jdih.bumn.go.id/lihat/perpres%20nomor%2055%20tahun%202019 http://dx.doi.org/10.1007/s40534-016-0117-3 http://dx.doi.org/10.1007/s40534-016-0117-3 http://dx.doi.org/10.1007/s40534-016-0117-3 http://dx.doi.org/10.1007/s40534-016-0117-3 https://doi.org/10.1080/16864360.2017.1419638 https://doi.org/10.1080/16864360.2017.1419638 https://doi.org/10.1080/16864360.2017.1419638 https://doi.org/10.1016/j.vacun.2020.12.004 https://doi.org/10.1016/j.vacun.2020.12.004 https://doi.org/10.1016/j.vacun.2020.12.004 https://doi.org/10.1016/j.vacun.2020.12.004 https://doi.org/10.1080/07391102.2020.1758788 https://doi.org/10.1080/07391102.2020.1758788 https://doi.org/10.1080/07391102.2020.1758788 https://doi.org/10.1080/07391102.2020.1758788 https://doi.org/10.1109/access.2020.3045792 https://doi.org/10.1109/access.2020.3045792 https://doi.org/10.1109/access.2020.3045792 https://doi.org/10.1038/s41598-021-85425-w https://doi.org/10.1038/s41598-021-85425-w https://doi.org/10.1038/s41598-021-85425-w http://dx.doi.org/10.1038/s41598-018-21058-w http://dx.doi.org/10.1038/s41598-018-21058-w http://dx.doi.org/10.1038/s41598-018-21058-w https://doi.org/10.1038/s41598-020-67211-2 https://doi.org/10.1038/s41598-020-67211-2 https://doi.org/10.1038/s41598-020-67211-2 https://doi.org/10.3390/s20123543 https://doi.org/10.3390/s20123543 https://doi.org/10.3390/s20123543 http://dx.doi.org/10.1016/j.ajic.2012.12.010 http://dx.doi.org/10.1016/j.ajic.2012.12.010 http://dx.doi.org/10.1016/j.ajic.2012.12.010 https://doi.org/10.1093/cid/cis839 https://doi.org/10.1093/cid/cis839 https://doi.org/10.1093/cid/cis839 https://doi.org/10.1093/cid/cis839 https://doi.org/10.1117/12.2068318 https://doi.org/10.1117/12.2068318 https://doi.org/10.1117/12.2068318 https://doi.org/10.1117/12.2068318 https://doi.org/10.1016/j.dcan.2015.03.001 https://doi.org/10.1016/j.dcan.2015.03.001 https://doi.org/10.1016/j.dcan.2015.03.001 https://doi.org/10.12962/j25796216.v4.i1.118 https://doi.org/10.12962/j25796216.v4.i1.118 https://doi.org/10.3389/frobt.2021.612750 https://doi.org/10.3389/frobt.2021.612750 https://doi.org/10.3389/frobt.2021.612750 https://intipdaqu.inovasi.lipi.go.id/paten/detailpatent?id=p00202006900 https://intipdaqu.inovasi.lipi.go.id/paten/detailpatent?id=p00202006900 https://doi.org/10.1109/icseea50711.2020.9306161 https://doi.org/10.1109/icseea50711.2020.9306161 https://doi.org/10.1109/icseea50711.2020.9306161 https://doi.org/10.1109/icseea50711.2020.9306161 https://doi.org/10.1109/icseea50711.2020.9306161 http://jdih.kemenperin.go.id/site/template3/2669 http://jdih.kemenperin.go.id/site/template3/2669 http://jdih.kemenperin.go.id/site/template3/2669 http://jdih.kemenperin.go.id/site/template3/2669 http://jdih.kemenperin.go.id/site/template3/2669 https://peraturan.bpk.go.id/home/details/166976/permenperin-no-15-tahun-2020 https://peraturan.bpk.go.id/home/details/166976/permenperin-no-15-tahun-2020 introduction ii. methods iii. results and discussions a. uvc subsystem b. disinfectant spray subsystem c. food warmer subsystem d. dcl calculation for rom20 iv. conclusion acknowledgment declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.214-221 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: sujito et al., “long-term forecasting for growth of electricity load based on customer sectors,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 214-221, dec. 2022. long-term forecasting for growth of electricity load based on customer sectors sujito a, *, ridho riski hadi b, langlang gumilar a, abdullah iskandar syah b, moh. zainul falah b, tran huy duy c a intelligent power and advance energy system, jurusan teknik elektro, universitas negeri malang jl. semarang no. 5 sumbersari, lowokwaru, malang, east java, 65145, indonesia b electrical engineering, electrical engineering department, universitas negeri malang jl. semarang no. 5 sumbersari, lowokwaru, malang, east java, 65145, indonesia c electrical engineering department, dalat university, vietnam 1 đường phù đổng thiên vương, phường 8, thành phố đà lạt, lâm đồng, vietnam received 25 may 2022; 1st revision 18 october 2022; 2nd revision 2 november 2022; 3rd revision 24 november 2022; 4th revision 14 december 2022; accepted 16 december 2022; published online 29 december 2022 abstract the availability of electrical energy is an important issue. along with the growth of the human population, electrical energy also increases. this study addresses problems in the operation of the electric power system. one of the problems that occur is the power imbalance due to scale growth between demand and generation. alternative countermeasures that can be done are to prepare for the possibility that will occur in the future or what we are familiar with forecasting. forecasting using the multiple linear regression method with this research variable assumes the household sector, business, industry, and public sectors, and is considered by the influence of population, gross regional domestic product, and district minimum wage. in forecasting, it is necessary to evaluate the accuracy using mean absolute percentage error (mape). mape evaluation results show a value of 0.142 % in the household sector, 0.085 % in the business sector, 1.983 % in the industrial sector, and 0.131 % in the total customer sector. ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: district minimum wage; gross regional domestic product; long-term forecasting; mean absolute percentage error; multiple linear regression; i. introduction electricity is one of many energies that are needed by society to support daily activities [1][2]. along with the increase in the total electrical loads, the electrical energy required was increased [3][4][5]. generally, an electric power system is divided into several customer sectors, including a housing sector, a commercial sector, an industrial sector, and a public or general sector [6][7]. one problem in the operation of the electric power system is a power imbalance between the power required and the power generated. the imbalance results in disruption of frequency stability and voltage drop in the system [8]. according to [9], which was explained in the electricity supply business plan, it was said that the one target of the state electricity company or perusahaan listrik negara (“pln”) is to be able to provide power capacity and electrical energy every year. to keep an electricity demand fulfilled, it is necessary to connect a supply of electrical energy according to demand and load forecasting that will take place in the future [1][10]. forecasting is a process of predicting a possible structured way that can take place in the future based on data from the past and the current periods to minimize errors [11][12]. the main factors that influence the forecasting of electricity load growth are macroeconomic problems such as economic growth, population, gross regional domestic product (grdp), etc. [13][14]. according to [15][16], predicting expenses in the future is usually done by analyzing a graph of expenses in the past to future * corresponding author. tel: +62-851-32014085 e-mail address: sujito.ft@um.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.214-221 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.214-221 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.214-221&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 215 periods, including short-term, medium-term, or long-term. short-term, mid-term, and long-term models are important to account for the complexity of load data and produce reliable forecasts [15]. forecasting methods are divided into three types, namely, monitoring, causal, and time series methods [17]. the three types are described in the form of table 1. based on table 1, this study uses a causal method with two techniques in determining forecasting results [18], namely simple regression and multiple regression, where both are required in forecasting for each explanatory variable (population, grdp, and district minimum wage). this research activity was done at west kotawaringin regency because west kotawaringin regency is the shaded area of pt pln (persero) ulp pangkalan bun. according to [19], in 2020, west kotawaringin regency was the district with the 4th largest population of 14 regencies or cities in central kalimantan province, with an average population growth rate in the last three years of 2.71 % annually. in addition, according to historical data from pt pln (persero) ulp pangkalan bun 2021, the growth rate in the number of customers has increased by 0.52 % every month starting from january 2018 to december 2020. therefore, the availability of electrical energy must be continuously monitored and maintained. therefore, pt pln (persero) ulp pangkalan bun needs to maintain a continuity of distribution of electrical energy. one of them by forecasting the growth of the electrical energy load in the future. in this research, long-term forecasting was done in each sector, such as the industrial, household, business, and general sectors. this is to support the maintenance of the availability of electrical energy and planning for the addition of electrical energy in the future by pt pln [20]. in addition, the data used is a type of linear interpolation because the data always increases and is stable every year, so this research can only be done at the end of each year. the factors that influence a forecasting growth of an electrical load used are the total population, grdp, and the minimum wage in the west kotawaringin area. this research uses a linear regression forecasting method. simple linear regression was used to predict the total population, grdp, and minimum wage in the west kotawaringin regency area. forecasting results from these variables with multiple linear regression were used to predict an amount of electricity load growth in industrial, household, business, and general sectors. calculation of the magnitude of the impact of each independent variable on the dependent variable was done using pearson's product moment analysis (r) and coefficient of determination (r2). then, the accuracy of measured forecasting is determined by mean absolute percent error (mape). ii. materials and methods a. correlation theory correlation is one of the existing methods in statistical analysis as a search for continuity between two variables with quantitative properties, i.e., to see the size of the impact given by an independent variable (independent) to a dependent variable (dependent). two variables are said to be correlated if a change in one variable will be accompanied by a change in another variable in an organized manner in one direction (positive correlation) or contradictory (negative correlation) [21][22][23]. this research was done using a pearson productmoment correlation technique and coefficient of determination. 1) pearson product-moment according to [24][25], in principle, pearson product-moment correlation is used to determine a correlation between two variables (bivariate model) which has an interval or ratio scale. pearson product-moment correlation can be interpreted to find whether there is a relationship between the x variable and the y variable. it is useful as an explanation of how much one variable contributes to another variable. the positive (+) and negative (-) signs represent a type of relationship between variables, and the value ranges from -1.0 to 1.0 as a strengthening statement of the relationship. mathematically, the pearson product-moment is described in equation (1): 𝑟 = 𝑛 ∑𝑋𝑋 − ∑𝑋 ∑𝑋 �{𝑛∑𝑋2 − (∑𝑋)2} {𝑛∑𝑋2 − (∑𝑋)2} (1) where r is the pearson product-moment, n is the customers point (x, y), x is the independent variable, and y is the dependent variable. the results of correlation calculation using a pearson product-moment method can represent how strong the relationship between variables was given. table 2 describes a representation strength of continuity between variables calculated using a pearson product-moment method [26]. the correlation rate is used as a result of decisions from variables that influence each other. table 1. types of forecasting forecasting methods description monitoring tracking signals causal linear regression, multiple regression, arima time series simple time series, advanced time series table 2. correlation representation using pearson product moment method value of r correlation rate 0.00 – 0.199 very low 0.20 – 0.399 low 0.40 – 0.599 medium 0.60 – 0.799 strong 0.80 – 1.000 very strong sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 216 2) coefficient of determination the coefficient of determination (equation (2)) is symbolized by r2 and is usually represented using a percentage (%). the coefficient of determination is a value used to measure the contribution of the independent variable (x) to the variation (increase/decrease) of the dependent variable (y). another explanation is that variable y can be described by variable x with a magnitude of r2 then the rest was described by other variables. another variation of y (the rest) was caused by many different factors that influence y as well and has been included in disturbance error [27][28]. the range coefficient of determination is 0 to 1, with 0 representing no continuity between the independent variables to the dependent variable and 1 representing a perfect relationship between these variables [28][29]. 𝑟2 = ((𝑛)( ∑𝑋𝑋)−(∑𝑋)(∑𝑋))2 ((𝑛(∑𝑋2)−(∑𝑋)2)(𝑛(∑𝑋2)−(∑𝑋)2)) (2) where r2 is the coefficient of determination. b. linear regression regression is one of many statistical methods that serve to see the pattern of the relationship between the response variable and predictor variable [30]. 1) simple linear regression according to [31][32], a simple linear regression is a linear regression that only considers one independent variable (x) and one dependent variable (y). in linear regression, the variable (y) can be expressed as a response variable, or in other terms, an output variable and not independent. while the variable (x) can be said to be a predictor variable (used to estimate y value), it can be expressed as an explanatory variable, input regressor, and independent. the simple linear regression equation model can be explained through equation (3) y = 𝑎 + bx (3) where a is the constant and b is the coefficient. the value of 𝑎 and b needs to be calculated using equation (4) and equation (5): 𝑎 = (∑𝑋)(∑𝑋2)−(∑𝑋)(∑𝑋𝑋) (𝑛)(∑𝑋2)−(∑𝑋)2 (4) 𝑏 = 𝑛 ∑𝑋𝑋−(∑𝑋)(∑𝑋) 𝑛(∑𝑋2)−(∑𝑋)2 (5) 2) multiple linear regression according to [33][34], multiple linear regression is a continuation of simple linear regression analysis. multiple linear regression uses one dependent variable (y) as the predicted target and several independent variables (x) as the variable used to predict a target. the coefficient on linear regression is an estimated value of the parameter in the regression model for the real condition (true condition). the coefficient for the linear regression model is an average value that has a chance of appearing on the y variable if a value of x1, x2, and xn was given. mathematically, multiple linear regression analysis is explained in equation (6). y = a + b1x1 + b2x2 + ... ... ... bkxk (6) where bk is the coefficient xk, x 1 is the 1 st independent variable, b1 is the coefficient x1, x 2 is the 2nd independent variable, b2 is the coefficient x2, and x 3 is the 3 rd independent variable. 3) forecasting accuracy forecasting accuracy is a measure of forecast error based on the magnitude of the difference between forecast results and actual demand. the measurement of forecasting accuracy aims to determine the performance or accuracy of forecasting results that have been done using certain methods and techniques. in this research, the mean absolute percentage error (mape) method was used to assess forecasting accuracy. according to [35][36], mape can be calculated by the following mathematical equation (7) 𝑀𝑀𝑀𝑀 = ∑ |𝐴𝐴−𝐹𝐴|𝑛𝐴=1 𝐴𝐴 𝑛 × 100 (7) where t is the period on data, ft is the forecasting data in period t, at is the actual data in period t, and n is the total forecasting data. mape results can be grouped based on the level of forecasting accuracy [37] as shown in table 3. parameter results are evaluated using mape and compared with the range value from mape to determine whether the accuracy level is high or low. 4) systematic research figure 1 shows the flow of research from table 3. mape parameters in forecasting value of mape prediction accuracy mape ≤ 10% high 10% < mape ≤ 20% good 20% < mape ≤ 50% reasonable mape > 50% low figure 1. research completion flow sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 217 beginning to end. it shows research data that has been collected and analyzed with two different output lines. in the first analysis, an output produced was to identify the correlation between independent variables and the dependent variable using a pearson product-moment method and coefficient of determination. while the other analysis, a results output, is the forecasting of electrical energy needs and continued by measuring the accuracy of the forecast. iii. results and discussions a. effect of correlation of forecasting variables in this study, the data used consisted of two types of variables, namely the independent variable and the dependent variable. independent variables are macroeconomic factors that can affect the dependent variable, such as population, grdp, and city minimum wage. the dependent variable is a variable that was influenced by macroeconomic factors; here is electricity data which is divided into four sectors, namely the household, business, industrial, and public sectors. based on the calculations performed using equation (1) and equation (2), the results of the correlation between the independent and the dependent variables are obtained. the correlation results are shown by the value of the pearson product moment (r) and the coefficient of determination (r2) listed in table 4. thus, we can see how much influence the independent variable has on the dependent variable based on the r and r2 values obtained. the results of the correlation calculation obtained for each independent variable and the dependent variable were corrected with the r value in table 2. these results indicate that the correlation value obtained is very strong and positive. this signifies that there is a very close relationship between the independent variable and the dependent variable. this means that if there is a change in the independent variable, there will also be a significant change in the dependent variable. b. forecasting based on variables that affect load demand based on calculations made using equations (3) to (6), the forecasting results for the growth of electricity loads for each sector are obtained. these sectors are the household, business, industrial, and public sectors. the calculation takes into account macro factors that can affect the growth of electricity expenses, such as population, grdp, and city minimum wage. the forecasting results are shown in table 5. thus, we can estimate the electricity load growth for each sector based on influencing macro factors. in general, each year, the energy growth in each sector has increased (see figure 2). this is because every year, it is influenced by population growth, as table 4. correlation between independent variable and dependent variable variable pearson product moment (r) coefficient of determination (r2) x1 to y1 0.998 0.995 x2 to y1 0.984 0.969 x3 to y1 0.996 0.991 x1, x2, x3 to y1 0.993 0.999 x1 to y2 0.978 0.957 x2 to y2 0.972 0.944 x3 to y2 0.975 0.950 x1, x2, x3 to y2 0.975 0.994 x1 to y3 0.976 0.953 x2 to y3 0.928 0.861 x3 to y3 0.978 0.957 x1, x2, x3 to y3 0.960 0.961 x1 to y4 0.999 0.997 x2 to y4 0.974 0.948 x3 to y4 0.998 0.996 x1, x2, x3 to y4 0.990 0.997 x1 to ytot 0.998 0.996 x2 to ytot 0.984 0.968 x3 to ytot 0.996 0.992 x1, x2, x3 to ytot 0.992 0.999 figure 2. load demand growth 0 20000 40000 60000 80000 100000 120000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 lo ad time for three years (month) y1 household y2 business y3 indusrty y4 general ytot customers sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 218 it is known through table 4 that the correlation between the two factors is strong. based on table 5, it can be seen that the number of electricity customers in each sector has always increased from january 2021 to december 2023. this increase is due to population growth and other sectors which have a high correlation. to measure the accuracy of forecasting the growth of this electrical load, equation (7), which is called the mean absolute percentage error (mape), can be used. the results of the calculation of forecasting accuracy according to this method can be seen in table 6. from these results, it can be seen that forecasting the growth of electricity loads in each sector has fairly high accuracy. in this case, the results of calculating the accuracy of the load forecasting using the linear regression method show that the mean absolute percentage error (mape) is quite small. this shows that load forecasting using the linear regression method is quite accurate in contrast to the results of the previous study [14], which showed that the linear regression method for forecasting urban demand loads has a larger mape value compared to the k-nearest neighbour (knn) method they use, which in their research method knn is more appropriate to the cases they use compared to the linear regression method. in the same case study, the auto-regressive (ar) method was applied to the same dataset to forecast each sector in january and december to ensure the training results. the results of the auto-regressive (ar) test are listed in table 7. in table 6, the mape value for forecasting the independent variables is 0.005 % for the population and 0.764 % for grdp. meanwhile, the mape value for forecasting the dependent variable is shown in table 6, which is 0.142 % for household sector electricity costs, 0.085 % for the business sector, 1.983 % for the industrial sector, and 0.131 % for table 5. the result of forecasting the growth of electricity load for each sector year month customer y1 y2 y3 y4 ytot household business industry general total customers 2021 january 75377 7770 32 2926 86104 february 75755 7780 32 2943 86510 march 76134 7790 32 2960 86916 april 76513 7800 32 2977 87322 may 76892 7810 33 2993 87729 june 77271 7820 33 3010 88135 july 77650 7830 33 3027 88541 august 78029 7840 34 3044 88947 september 78408 7850 34 3061 89353 october 78787 7861 34 3077 89759 november 79166 7871 34 3094 90165 december 79545 7881 35 3111 90571 2022 january 79924 7891 35 3128 90978 february 80303 7901 35 3145 91384 march 80682 7911 36 3162 91790 april 81061 7921 36 3178 92196 may 81440 7931 36 3195 92602 june 81818 7941 36 3212 93008 july 82197 7951 37 3229 93414 august 82576 7961 37 3246 93820 september 82955 7972 37 3262 94227 october 83334 7982 38 3279 94633 november 83713 7992 38 3296 95039 december 84092 8002 38 3313 95445 2023 january 84471 8012 38 3330 95851 february 84850 8022 39 3347 96257 march 85229 8032 39 3363 96663 april 85608 8042 39 3380 97069 may 85987 8052 40 3397 97476 june 86366 8062 40 3414 97882 july 86745 8072 40 3431 98288 august 87124 8083 40 3447 98694 september 87503 8093 41 3464 99100 october 87881 8103 41 3481 99506 november 88260 8113 41 3498 99912 december 88639 8123 42 3515 100318 sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 219 customers as a whole. in addition, in other tests using different methods, as forecasting comparisons are shown in table 7, the forecasting results prove the same as the calculation of equations (3) to (6). this proves that the cases used are in accordance with the linear regression method, where the data used is time series. based on these results, forecasting the growth of electricity loads in all sectors can be used with a high accuracy value because the mape value is below 10 %, according to table 3. with the results of forecasting in 2023, it can be used as a comparison in increasing power capacity that is able to support the energy demand needs of consumers from various sectors. iv. conclusion the population, grdp, and minimum wage have a very strong (positive) influence on the growth of the electricity load in each customer sector. the results of forecasting the growth of the electrical load showed a steady increase. the results of the measurement of the accuracy of the electricity load table 6. forecasting accuracy results with mape year month error (%) y1 y2 y3 y4 ytot household business industry general total customers 2021 january 0.169 0.084 3.884 0.549 0.171 february 0.134 0.051 4.970 0.118 0.123 march 0.411 0.005 3.166 0.198 0.347 april 0.234 0.013 2.175 0.271 0.209 may 0.045 0.006 1.184 0.357 0.051 june 0.187 0.052 0.192 0.358 0.145 july 0.268 0.085 3.401 0.276 0.216 august 0.326 0.050 2.451 0.030 0.278 september 0.013 0.096 1.501 0.115 0.024 october 0.343 0.088 0.550 0.118 0.310 november 0.381 0.134 4.765 0.081 0.343 december 0.169 0.008 2.704 0.316 0.134 2022 january 0.019 0.170 1.647 0.367 0.021 february 0.195 0.120 0.590 0.379 0.171 march 0.277 0.102 0.466 0.195 0.257 april 0.202 0.269 1.523 0.091 0.204 may 0.285 0.317 2.580 0.335 0.288 june 0.037 0.102 3.637 0.151 0.029 july 0.030 0.150 0.667 0.482 0.028 august 0.224 0.120 1.684 0.848 0.212 september 0.138 0.037 2.700 0.676 0.140 october 0.037 0.007 3.716 0.206 0.039 november 0.117 0.063 2.749 0.229 0.114 december 0.076 0.080 1.805 0.228 0.065 2023 january 0.050 0.069 0.490 0.153 0.045 february 0.115 0.072 0.826 0.478 0.109 march 0.126 0.049 1.381 0.618 0.127 april 0.104 0.039 0.110 0.436 0.102 may 0.003 0.081 2.212 0.219 0.003 june 0.040 0.058 0.985 0.040 0.032 july 0.076 0.074 2.990 0.138 0.056 august 0.014 0.077 1.802 0.031 0.019 september 0.103 0.066 0.614 0.313 0.106 october 0.103 0.034 0.574 0.487 0.104 november 0.027 0.096 1.762 0.002 0.015 december 0.053 0.132 2.951 0.242 0.065 mape 0.142 0.085 1.983 0.281 0.131 table 7. forecasting with auto-regressive (ar) method month (2023) customer per sector total customer house business industry general january 84470896 8012142 38183383 3329843 95851117 december 8863886 8123124 41202297 3514834 100318076 sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 220 growth forecast conducted by mape in the household sector are 0.142 %, business is 0.085 %, the industry is 1.983 %, and the number of customers is 0.131 %. mape value < 10 %, so the accuracy of forecasting the growth of electricity load in all sectors is high. in further research, the use of other training methods can be used as a comparison for the results of forecasting the electrical loads in kalimantan. acknowledgments thanks are conveyed to the institute for research and community service (lp2m) state university of malang for funding this research activity through basic research grants – thesis research in 2022. declarations author contribution sujito: formal analysis, validation, data curation. r.r. hadi, l. gumilar, t.h. duy: conceptualization, formal analysis, resources. a.i. syah, m.z. falah: writing, formal analysis, software operations, visualization, funding acquisition. funding statement thanks are conveyed to the institute for research and community service (lp2m) state university of malang for funding this research activity through basic research grants – thesis research in 2022 no. 19.5.1259/un32.20.1/lt/2022. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] m. subekti, i. a. rahardjo, and d. rosyanti, “forecasting electrical energy demand of pt. pln (persero) up3 sukabumi using analytical, econometrics, and trends methods,” iop conference series: materials science and engineering, vol. 1098, no. 4, p. 042032, 2021. [2] k. b. lindberg, p. seljom, h. madsen, d. fischer, and m. korpås, “long-term electricity load forecasting: current and future trends,” utilities policy, vol. 58, pp. 102–119, 2019. [3] a. setiawan, “losses sharing regulation as a solution for spike losses at pln’s distribution system caused by energy over production from independent power producers,” in 2020 international conference on technology and policy in energy and electric power (ict-pep), bandung, indonesia, sep., pp. 219–224, 2020. [4] g. zhang and j. guo, “a novel method for hourly electricity demand forecasting,” ieee transactions on power systems, vol. 35, no. 2, pp. 1351–1363, 2019. [5] s. aslam, h. herodotou, s. m. mohsin, n. javaid, n. ashraf, and s. aslam, “a survey on deep learning methods for power load and renewable energy forecasting in smart microgrids,” renewable and sustainable energy reviews, vol. 144, p. 110992, 2021. [6] z. a. khan et al., “efficient short-term electricity load forecasting for effective energy management,” sustainable energy technologies and assessments, vol. 53, p. 102337,, 2022. [7] l. peng, l. wang, d. xia, and q. gao, “effective energy consumption forecasting using empirical wavelet transform and long short-term memory,” energy, vol. 238, p. 121756,, 2022. [8] h. zhou, y. zhang, l. yang, q. liu, k. yan, and y. du, “shortterm photovoltaic power forecasting based on long short term memory neural network and attention mechanism,” ieee access, vol. 7, pp. 78063–78074, 2019. [9] j. fahmi, j. windarta, and a. y. wardaya, “studi awal penerapan distributed generation untuk optimalisasi plts atap on grid pada pelanggan pln sistem jawa bali untuk memenuhi target ebt nasional,” jurnal energi baru dan terbarukan, vol. 2, no. 1, pp. 1–13, 2021. [10] l. wen, k. zhou, and s. yang, “load demand forecasting of residential buildings using a deep learning model,” electric power systems research, vol. 179, p. 106073, 2020. [11] y. yu, j. cao, and j. zhu, “an lstm short-term solar irradiance forecasting under complicated weather conditions,” ieee access, vol. 7, pp. 145651–145666, 2019. [12] m. pavlicko, m. vojteková, and o. blažeková, “forecasting of electrical energy consumption in slovakia,” mathematics, vol. 10, no. 4, p. 577, 2022. [13] b. nepal, m. yamaha, a. yokoe, and t. yamaji, “electricity load forecasting using clustering and arima model for energy management in buildings,” japan architectural review, vol. 3, no. 1, pp. 62–76, 2020. [14] n. j. johannesen, m. kolhe, and m. goodwin, “relative evaluation of regression tools for urban area electrical energy demand forecasting,” journal of cleaner production, vol. 218, pp. 555–564, 2019. [15] h. riahi-madvar, m. dehghani, r. memarzadeh, and b. gharabaghi, “short to long-term forecasting of river flows by heuristic optimization algorithms hybridized with anfis,” water resources management, vol. 35, no. 4, pp. 1149–1166, 2021. [16] a. sherstinsky, “fundamentals of recurrent neural network (rnn) and long short-term memory (lstm) network,” physica d: nonlinear phenomena, vol. 404, p. 132306, 2020. [17] p. malhan and m. mittal, “a novel ensemble model for longterm forecasting of wind and hydro power generation,” energy conversion and management, vol. 251, p. 114983, 2022. [18] n. talkhi, n. a. fatemi, z. ataei, and m. j. nooghabi, “modeling and forecasting number of confirmed and death caused covid-19 in iran: a comparison of time series forecasting methods,” biomedical signal processing and control, vol. 66, p. 102494, 2021. [19] r. sihite, “analisis pengaruh pendapatan perkapita, jumlah konsumsi dan pertumbuhan ekonomi di kabupaten/kota provinsi kalimantan tengah,” jepp: jurnal ekonomi pembangunan dan pariwisata, vol. 2, no. 1, pp. 46–57, 2022 [20] p. mangera, “perkiraan kebutuhan energi listrik jangka panjang pada pt. pln (persero) wilayah papua dan papua barat area merauke dengan menggunakan metode regresi linier,” mustek anim ha, vol. 7, no. 3, 2018. [21] j. deng, y. deng, and k. h. cheong, “combining conflicting evidence based on pearson correlation coefficient and weighted graph,” international journal of intelligent systems, vol. 36, no. 12, pp. 7443–7460, 2021. [22] h. zhu, x. you, and s. liu, “multiple ant colony optimization based on pearson correlation coefficient,” ieee access, vol. 7, pp. 61628–61638, 2019. [23] p. schober, c. boer, and l. a. schwarte, “correlation coefficients: appropriate use and interpretation,” anesthesia & analgesia, vol. 126, no. 5, pp. 1763–1768, 2018. [24] f. zinzendoff okwonu, b. laro asaju, and f. irimisose arunaye, “breakdown analysis of pearson correlation coefficient and robust correlation methods,” iop conference series: materials science and engineering, vol. 917, no. 1, 2020. [25] a. ali et al., “a k-nearest neighbours based ensemble via optimal model selection for regression,” ieee access, vol. 8, pp. 132095–132105, 2020. [26] m. ausloos, a. eskandary, p. kaur, and g. dhesi, “evidence for gross domestic product growth time delay dependence over foreign direct investment. a time-lag dependent correlation study,” physica a: statistical mechanics and its applications, vol. 527, p. 121181, 2019. https://mev.lipi.go.id/ https://doi.org/10.1088/1757-899x/1098/4/042032 https://doi.org/10.1088/1757-899x/1098/4/042032 https://doi.org/10.1088/1757-899x/1098/4/042032 https://doi.org/10.1088/1757-899x/1098/4/042032 https://doi.org/10.1088/1757-899x/1098/4/042032 https://doi.org/10.1016/j.jup.2019.04.001 https://doi.org/10.1016/j.jup.2019.04.001 https://doi.org/10.1016/j.jup.2019.04.001 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/ict-pep50916.2020.9249826 https://doi.org/10.1109/tpwrs.2019.2941277 https://doi.org/10.1109/tpwrs.2019.2941277 https://doi.org/10.1109/tpwrs.2019.2941277 https://doi.org/10.1016/j.rser.2021.110992 https://doi.org/10.1016/j.rser.2021.110992 https://doi.org/10.1016/j.rser.2021.110992 https://doi.org/10.1016/j.rser.2021.110992 https://doi.org/10.1016/j.rser.2021.110992 https://doi.org/10.1016/j.seta.2022.102337 https://doi.org/10.1016/j.seta.2022.102337 https://doi.org/10.1016/j.seta.2022.102337 https://doi.org/10.1016/j.seta.2022.102337 https://doi.org/10.1016/j.energy.2021.121756 https://doi.org/10.1016/j.energy.2021.121756 https://doi.org/10.1016/j.energy.2021.121756 https://doi.org/10.1016/j.energy.2021.121756 https://doi.org/10.1109/access.2019.2923006 https://doi.org/10.1109/access.2019.2923006 https://doi.org/10.1109/access.2019.2923006 https://doi.org/10.1109/access.2019.2923006 https://doi.org/10.14710/jebt.2021.10038 https://doi.org/10.14710/jebt.2021.10038 https://doi.org/10.14710/jebt.2021.10038 https://doi.org/10.14710/jebt.2021.10038 https://doi.org/10.14710/jebt.2021.10038 https://doi.org/10.1016/j.epsr.2019.106073 https://doi.org/10.1016/j.epsr.2019.106073 https://doi.org/10.1016/j.epsr.2019.106073 https://doi.org/10.1109/access.2019.2946057 https://doi.org/10.1109/access.2019.2946057 https://doi.org/10.1109/access.2019.2946057 https://doi.org/10.3390/math10040577 https://doi.org/10.3390/math10040577 https://doi.org/10.3390/math10040577 https://doi.org/10.1002/2475-8876.12135 https://doi.org/10.1002/2475-8876.12135 https://doi.org/10.1002/2475-8876.12135 https://doi.org/10.1002/2475-8876.12135 https://doi.org/10.1016/j.jclepro.2019.01.108 https://doi.org/10.1016/j.jclepro.2019.01.108 https://doi.org/10.1016/j.jclepro.2019.01.108 https://doi.org/10.1016/j.jclepro.2019.01.108 https://doi.org/10.1007/s11269-020-02756-5 https://doi.org/10.1007/s11269-020-02756-5 https://doi.org/10.1007/s11269-020-02756-5 https://doi.org/10.1007/s11269-020-02756-5 https://doi.org/10.1007/s11269-020-02756-5 https://doi.org/10.1016/j.physd.2019.132306 https://doi.org/10.1016/j.physd.2019.132306 https://doi.org/10.1016/j.physd.2019.132306 https://doi.org/10.1016/j.enconman.2021.114983 https://doi.org/10.1016/j.enconman.2021.114983 https://doi.org/10.1016/j.enconman.2021.114983 https://doi.org/10.1016/j.enconman.2021.114983 https://doi.org/10.1016/j.bspc.2021.102494 https://doi.org/10.1016/j.bspc.2021.102494 https://doi.org/10.1016/j.bspc.2021.102494 https://doi.org/10.1016/j.bspc.2021.102494 https://doi.org/10.1016/j.bspc.2021.102494 https://doi.org/10.52300/jepp.v2i1.4433 https://doi.org/10.52300/jepp.v2i1.4433 https://doi.org/10.52300/jepp.v2i1.4433 https://doi.org/10.52300/jepp.v2i1.4433 https://doi.org/10.35724/mustek.v7i3.1736 https://doi.org/10.35724/mustek.v7i3.1736 https://doi.org/10.35724/mustek.v7i3.1736 https://doi.org/10.35724/mustek.v7i3.1736 https://doi.org/10.1002/int.22593 https://doi.org/10.1002/int.22593 https://doi.org/10.1002/int.22593 https://doi.org/10.1002/int.22593 https://doi.org/10.1109/access.2019.2915673 https://doi.org/10.1109/access.2019.2915673 https://doi.org/10.1109/access.2019.2915673 https://doi.org/10.1213/ane.0000000000002864 https://doi.org/10.1213/ane.0000000000002864 https://doi.org/10.1213/ane.0000000000002864 https://doi.org/10.1088/1757-899x/917/1/012065 https://doi.org/10.1088/1757-899x/917/1/012065 https://doi.org/10.1088/1757-899x/917/1/012065 https://doi.org/10.1088/1757-899x/917/1/012065 https://doi.org/10.1109/access.2020.3010099 https://doi.org/10.1109/access.2020.3010099 https://doi.org/10.1109/access.2020.3010099 https://doi.org/10.1016/j.physa.2019.121181 https://doi.org/10.1016/j.physa.2019.121181 https://doi.org/10.1016/j.physa.2019.121181 https://doi.org/10.1016/j.physa.2019.121181 https://doi.org/10.1016/j.physa.2019.121181 sujito et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 214-221 221 [27] d. chicco, m. j. warrens, and g. jurman, “the coefficient of determination r-squared is more informative than smape, mae, mape, mse and rmse in regression analysis evaluation,” peerj computer science, vol. 7, pp. 1–24, 2021. [28] s. nakagawa, p. c. d. johnson, and h. schielzeth, “the coefficient of determination r2 and intra-class correlation coefficient from generalized linear mixed-effects models revisited and expanded,” journal of the royal society interface, vol. 14, no. 134, 2017. [29] a. m. da silva filho, g. f. zebende, a. p. n. de castro, and e. f. guedes, “statistical test for multiple detrended crosscorrelation coefficient,” physica a: statistical mechanics and its applications, vol. 562, p. 125285, 2021. [30] t. m. hope, “linear regression,” in machine learning, elsevier, pp. 67–81, 2020. [31] m. sharifzadeh, a. sikinioti-lock, and n. shah, “machinelearning methods for integrated renewable power generation: a comparative study of artificial neural networks, support vector regression, and gaussian process regression,” renewable and sustainable energy reviews, vol. 108, pp. 513– 538, 2019. [32] h.-y. kim, “statistical notes for clinical researchers: simple linear regression 3 – residual analysis,” restorative dentistry & endodontics, vol. 44, no. 1, pp. 1–8, 2019. [33] t. a. trunfio, a. scala, a. d. vecchia, a. marra, and a. borrelli, “multiple regression model to predict length of hospital stay for patients undergoing femur fracture surgery at ‘san giovanni di dio e ruggi d’aragona’ university hospital,” in european medical and biological engineering conference, pp. 840–847, 2020. [34] m. korkmaz, “a study over the general formula of regression sum of squares in multiple linear regression,” numerical methods for partial differential equations, vol. 37, no. 1, pp. 406–421, 2021. [35] n. kusuma, m. roestam, and l. pasca, “the analysis of forecasting demand method of linear exponential smoothing,” international journal of educational administration, management, and leadership, pp. 7–18, 2020. [36] s. prayudani, a. hizriadi, y. y. lase, and y. fatmi, “analysis accuracy of forecasting measurement technique on random knearest neighbor (rknn) using mape and mse,” in journal of physics: conference series, vol. 1361, no. 1, p. 012089, 2019. [37] e. vivas, h. allende-cid, and r. salas, “a systematic review of statistical and machine learning methods for electrical power forecasting with reported mape score,” entropy, vol. 22, no. 12, p. 1412, 2020. https://doi.org/10.7717/peerj-cs.623 https://doi.org/10.7717/peerj-cs.623 https://doi.org/10.7717/peerj-cs.623 https://doi.org/10.7717/peerj-cs.623 https://doi.org/10.1098/rsif.2017.0213 https://doi.org/10.1098/rsif.2017.0213 https://doi.org/10.1098/rsif.2017.0213 https://doi.org/10.1098/rsif.2017.0213 https://doi.org/10.1098/rsif.2017.0213 https://doi.org/10.1016/j.physa.2020.125285 https://doi.org/10.1016/j.physa.2020.125285 https://doi.org/10.1016/j.physa.2020.125285 https://doi.org/10.1016/j.physa.2020.125285 https://doi.org/10.1016/b978-0-12-815739-8.00004-3 https://doi.org/10.1016/b978-0-12-815739-8.00004-3 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.1016/j.rser.2019.03.040 https://doi.org/10.5395/rde.2019.44.e11 https://doi.org/10.5395/rde.2019.44.e11 https://doi.org/10.5395/rde.2019.44.e11 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1007/978-3-030-64610-3_94 https://doi.org/10.1002/num.22533 https://doi.org/10.1002/num.22533 https://doi.org/10.1002/num.22533 https://doi.org/10.1002/num.22533 https://doi.org/10.51629/ijeamal.v1i1.3 https://doi.org/10.51629/ijeamal.v1i1.3 https://doi.org/10.51629/ijeamal.v1i1.3 https://doi.org/10.51629/ijeamal.v1i1.3 https://doi.org/10.1088/1742-6596/1361/1/012089 https://doi.org/10.1088/1742-6596/1361/1/012089 https://doi.org/10.1088/1742-6596/1361/1/012089 https://doi.org/10.1088/1742-6596/1361/1/012089 https://doi.org/10.3390/e22121412 https://doi.org/10.3390/e22121412 https://doi.org/10.3390/e22121412 https://doi.org/10.3390/e22121412 introduction ii. materials and methods a. correlation theory 1) pearson product-moment 2) coefficient of determination b. linear regression 1) simple linear regression 2) multiple linear regression 3) forecasting accuracy 4) systematic research iii. results and discussions a. effect of correlation of forecasting variables b. forecasting based on variables that affect load demand iv. conclusion acknowledgments declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.101-112 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: j. a. prakosa et al., “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 101-112, dec. 2022. experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs) jalu ahmad prakosa a, *, hai wang b, edi kurniawan a, swivano agmal c, muhammad jauhar kholili c a research center for photonics, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia b discipline of engineering and energy, murdoch university 90 south street, murdoch, western australia, 6150, australia c research center for quantum physics, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia received 27 march 2022; 1st revision 22 may 2022; 2nd revision 29 may 2022; accepted 30 may 2022; published online 29 december 2022 abstract controller design for airplane flight control is challenged to achieve an optimum result, particularly for safety purposes. the experiment evaluated the linear quadratic regulator (lqr) method to research the optimal gain of proportional-integralderivative (pid) to hover accurately the bicopter model by minimizing error. the 3 degree of freedom (dof) helicopter facility is a suitable bicopter experimental simulator to test its complex multiple input multiple output (mimo) flight control model to respond to the challenge of multipurpose drone control strategies. the art of lqr setting is how to search for appropriate cost matrices scaling to optimize results. this study aims to accurately optimize take-off position control of the bicopter model by investigating lqr cost matrices variation in actual experiments. from the experimental results of weighted matrix variation on the bicopter simulator, the proposed lqr method has been successfully applied to achieve asymptotic stability of roll angle, although it yielded a significant overshoot. moreover, the overshoot errors had good linearity to weighting variation. despite that, the implementation of cost matrices is limited in the real bicopter experiment, and there are appropriate values for achieving an optimal accuracy. moreover, the unstable step response of the controlled angle occurred because of excessive weighting. ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: experimental evaluation; cost matrices; lqr; bicopter; mimo flight control. i. introduction research aircraft flight control [1] is complicated due to its dynamic behavior and uncertainties. the nonlinear behavior of plants also must be taken to account. not only rotors [2], [3] characteristics but also aerodynamic behaviors of aircraft cause its uncertainty and dynamic. besides, it must control an airplane's rotation angles in three dimensions: pitch, roll, and yaw. interaxis coupling between angles adds a more complex task [4]. because of these reasons, flight control is an exciting research topic. flight control has a vital role in running unmanned aerial vehicles (uavs) [5], [6] well, becoming famous today. the application of uavs in remote sensing, surveillance, and disaster mitigation has gained more attention because of their relatively low cost, more accurate, and higher maneuvers possibility than on-board pilots [1]. the excellent development of uavs flight control can ensure its application successfully, although the major use of dc motors provides challenges. the helicopter is a uav type with excellent maneuverability and versatility for flight control studies. moreover, this type has more advantages than fixed wings uavs in smaller landing areas [7]. bicopter is a helicopter-type with two rotors on both * corresponding author. tel: +62-8888311358 e-mail address: jalu.ahmad.prakosa@brin.go.id https://dx.doi.org/10.14203/j.mev.2022.v13.101-112 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.101-112 https://dx.doi.org/10.14203/j.mev.2022.v13.101-112 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.101-112&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 102 arms for its maneuver, which is famously implemented by the chinook helicopter [8]. the plant of 3 dof helicopters for the laboratory, which quanser consulting inc. develops, is a useful experimental tool to test the flight control method strategies for the bicopter model [9]. two propellers to generate thrust for lifting the helicopter are driven by both dc motors. the aircraft has free movement to pitch from its center on one side of the arm. moreover, the arm allows the helicopter body to move in the elevation and yaw directions. here is figure 1, which describes the bicopter simulator. figure 1 shows that a counterweight is used as a balancing from the propellers. encoder sensors install some joints; therefore, the helicopter's angular rotation, namely pitch, roll, and yaw, can be measured accurately as feedback elements. the data acquisition is connected between the personal computer (pc) and motor through a driver and amplifier. the pitch, roll, and yaw measurement is delivered via its data acquisition to pc. the application software of matlab simulink can be used to design the flight control technique due to its accessibility to the plant. hence, the 3 dof helicopter is a suitable experimental platform to test and validate new flight control strategies to deal with dynamic behavior, nonlinearities, and the helicopter's uncertainties as a uav plant. besides implementing adaptive control with lqr [10] to deal with dynamic behavior, nonlinearities, and uncertainties, the method of optimal control can also be used. optimal control is a method to achieve the desired dynamic and deal with researching a control law system over a while to optimize an objective function. some researchers applied many optimal control theories to the helicopter as an object. the application of the h-infinity optimal control [3] approach was analyzed to solve highorder unmodeled dynamics on a helicopter. sliding mode control [11] was simulated and studied for a laboratory helicopter of 3 dof [12]. robust lqr attitude control [13], [14] was built for aggressive maneuvers on 3 dof helicopters, both theory and experiment [15]. lqr theory minimizes the cost function to solve dynamic system operation, commonly implemented in flight control [16]. the research of cost matrices variation of lqr algorithm for flight control [17] is not only exciting but also challenging to be conducted. the weighting of cost matrices [18] supplied by an engineer may have different behavior on another plant. the platform of 3 dof helicopters should be used to study experimentally optimal flight control strategies for uav type of bicopter [19]. this research aims to investigate the cost matrices variation of lqr theory to evaluate the most accurate flight control experimentally for the bicopter plant as an optimization strategy. the efficient weighting on cost matrices should be analyzed to achieve optimal flight control strategies [20]. the optimal desire can be obtained by minimizing its error or cost function in the lqr term. therefore, the accurate position of the helicopter must be achieved to ensure its safety. in addition, it would succeed the application of uav. besides, the following points provide a summary of our contributions: • demonstrate mimo control system of the bicopter model through pid controller signal. • test the strategies of optimal control theory on experimental tools of 3 dof helicopters as the bicopter simulator. • investigate cost matrices weighting variation of lqr optimization calculation. • assess the accuracy of flight position on the lqr method through each error. • develop cost matrices of lqr calculation to get minimal errors of angle control from bicopter experimental results. this activity is conducted as the following: section ii indicates the modeling of the bicopter system. cost matrices variation of lqr calculation is investigated and discussed in section iii as experimental evaluation. finally, section iv presents the conclusion of this work. ii. materials and methods a. design and method the angles of rotation of 3-dof helicopter is analogous with chinook bicopter description; therefore, the pitch, roll, and yaw can be seen in figure 2 as general aircraft flight control below: the set of the angle's rotation for flight control of chinook's bicopter in figure 2 is implemented to the 3 dof helicopter facilities. its free body diagram is illustrated in figure 3. figure 1. the experimental platform of 3 dof helicopter as bicopter simulator j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 103 the angles of rotation and the force illustration are described in figure 3. the signs of each axis for angles of rotation are determined below: a) the roll angle lies in the direction of the x-axis rotation. the horizontal position of a helicopter if r(t)=0, then roll angle becomes positive, r(t)>0, a helicopter flies higher than counterweight. b) the yaw angle is in the direction of the z-axis rotation. the yaw angle is positive, ɣ(t)>0, if it rotates counterclockwise (ccw) direction. c) the pitch angle is situated in the direction of the y-axis rotation. the pitch angle increases positively, p(t)>0, when the front motor is higher than the back motor. the newton’s law i works when the helicopter hovers stationary or moves at a steady speed. because of that reason, the whole force sum on the free body diagram of the helicopter is zero when it hovers. those circumstances are illustrated in equations (1), (2), (3), and (4). 0=−=∆ w f t ff (1) the total torque is also zero. 0wt =τ−τ=τ∆ (2) gbmalfmalwmwlfkalov )(2 −−= (3) fkal gbmalfmalwmwl ov 2 )( −− = (4) the equation (4) shows the voltage (vo) produced by the amplifier to drive the dc motor. the mathematical model of control systems design for analysis usually uses a state-space model that applies state variables to describe a system by a set of first-order differential or difference equations in equation (5) and figure 4. ducxy;buaxx +=+= • (5) where: x = state vector; y = output vector; u = input vector; a = state matrix; b = input matrix; c = output matrix; d = feedforward matrix. the state vector is defined as equation (6):     γγ= ••• prprx t (6) on the other hand, the output vector can be written as (7): [ ]γ= pry t (7) figure 2. angles rotation of bicopter figure 3. free body diagram of 3 dof helicopter figure 4. state-space model j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 104 furthermore, the other state-space matrices are set in equation (8), (9), (10), and (11):                     ++ −− = 0000 2 al.fm.2 2 hl.fm.2 2 wl.wm g).bm.alfm.alwm.wl(0 000000 000000 100000 010000 001000 a (8)                         − ++ = 00 2 hl.fm.2 fk 2 hl.fm.2 fk 2 al.fm.2 2 wl.wm fk.al 2 al.fm.2 2 wl.wm fk.al 00 00 00 b (9)         = 000100 000010 000001 c (10)         = 00 00 00 d (11) b. proposed cost matrices variation of lqr algorithm the lqr theory applied a mathematical algorithm that minimizes a cost function by weighting factors supplied by an engineer. the sum of the deviations of critical measurements, such as pitch, roll, and yaw on flight control, is often called the cost function. these settings are usually implemented on machines or processes, particularly on airplanes. further, the lqr algorithm is an automated method of finding an optimal statefeedback controller of close loop systems [21] as shown in figure 5. from the state-feedback law in figure 5, the input vector is indicated in equation (12): kxu −= (12) state-feedback gains k becomes the optimal gain matrix to minimize the quadratic cost function. input, u, provides the optimal control signal when the performance index function j is minimized on equation (13). selecting appropriate weighting matrices q and r that indicates an important relationship between the state error and control signal in the performance index function aims for the optimal controller design. dt 0 )nutx2rutuqxtx()u(j ∫ ∞ ++= (13) generally, for simple, n is set to 0 (n=0) and becomes equation (14). dt 0 )rutuqxtx()u(j ∫ ∞ += (14) principally, the optimal gain of lqr can be determined by solving an algebraic riccati equation. however, it is not efficient in computation time. therefore, the calculation is held by the application program of matlab simulink. the integrals of the roll and yaw states are included in equation (15) as augmented state vectors from equation (6).     ∫∫ • γ •• γ= prprprtx (15) because the updated state vector in equation (15) has eight columns, the cost matrix q also has an 8x8 matrix size in equation (16).                           ∫ ∫ • γ • • γ p0000000 0r000000 0000000 000p0000 0000r000 0000000 000000p0 0000000r (16) then the weighting matrix, r, is written in equation (17).       = c0 0c r (17) the constant values, c, are chosen 0.01<c<1, for example c=0.05. state-feedback gains k are calculated by lqr calculation on equation (14) and state-space model of equation (5) to generate pid coefficient gains of motor voltage in equation (18).         = 8,2 k 7,2 k 6,2 k 5,2 k 4,2 k 3,2 k 2,2 k 1,2 k 8,1 k 7,1 k 6,1 k 5,1 k 4,1 k 3,1 k 2,1 k 1,1 k k (18) figure 5. lqr close-loop diagram j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 105 the k matrix on 2x8 indicates the number of rows as output for two motor voltages, namely front motor voltage vf and back motor voltage vb. further, the number of columns shows the pid gains, which are the third of the first columns for proportional coefficient kp, the following two columns for derivative coefficient kd, and the last two columns for integral coefficient ki. therefore, equation (18) is developed from (15). this mimo controller [22] of 3 dof helicopter can be generally illustrated in figure 6. the mimo [23] diagram (figure 6) explains clearly why the state-feedback gains k have two rows and eight columns as k2x8. the final outputs are voltages to drive both front and back motor from pid gains of k on equation (18) and motor voltage of vo on equation (4) as following equation (19):       +=      o o 8,2 b f v v k v v (19) investigation of cost matrices variation on lqr algorithm is proposed to research roll (r) weighting adjustment of q matrix in the real experiment on bicopter simulator facilities because this angle is directly related to take-off position. the stochastic fractal search (sfs) has been applied to optimize lqr through q and r weighting matrices in quadcopter simulation [24]. on the other hand, this research wants to investigate weighting matrices variation in an actual experiment of bicopter to optimize its accuracy. iii. results and discussions the variation of cost matrix q on equation (16) was implemented by weighting adjustment to r angle due to the importance of helicopter take-off circumstances. the factory initially set the roll and yaw by 100 and 10, respectively. further, the pitch was set to 1 then the other values of derivative and integral followed it. attentively, the priority of a controlling factor had the heavier weight component due to lqr optimization theory. hence, r: p: ɣ= 100: 1:10 meant that the r angle control was more crucial 100 times than p angle control. it also implied that the r angle control was more priority ten times than ɣ angle control. we only select yaw as the representative angle because of interaxis coupling between pitch and yaw angles. the prime concern of angle rotation is related to the take-off position of bicopter. the default of matrix q from equation (16) was filled to equation (20):                       = 1.00000000 010000000 00200000 00000000 00000000 000001000 00000010 0000000100 q (20) because of that reason, the variation of r weighting is selected from 25 to 1000 scale. there were three measuring points of r angles at -10°, 0°, and 10°. these angles (figure 7) were implemented as the take-off position of the helicopter. time measurement was collected for 20 seconds. the comparison on more than one angle measuring point must be conducted to ensure the lqr optimal control algorithm's effectiveness on the angle control method. due to the focus on r angle as the helicopter's take-off position, the other angles, namely p and ɣ, were set to 0°. firstly, the experimental results by setting an angle of roll and yaw at -10° are shown in figure 8 and figure 9, respectively. the proposed lqr methods in equations (14), (16), (18), and figure 6 have successfully controlled both roll and yaw angle at -10° measuring point. the variation of weighting on the q cost matrix affected the stability of steps response of r angle at -10° setting point. the stability of angle control could be calculated by error, e, which was the difference between a measured angle and a set angle. besides, figure 6. the overall mimo control diagram of bicopter figure 7. three measuring points of r angle j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 106 the error could be analogous to the cost function, which should be minimized for control optimization in the lqr term. the performance index of the quadratic cost function, j, as in equation (14), was minimized as the error in this research to equation (21). dt 0 )rutuqxtx()t(e ∫ ∞ += (21) all symbols are explained in table 1. the illustration of cost matrices scaling of lqr theory [18] is described in figure 10, which aims to minimize error as a equation (21). in other words, the larger weight of cost matrices [25] was to achieve an optimal accuracy position of angle control. how to find appropriate cost matrices weighting to optimize desired was an art of lqr setting. figure 8 showed that the proposed lqr method has successfully minimized errors to zero, which achieved asymptotic stability since errors closed to be zero as time ran in unlimited time ( 0lim = ∞→ e t ). moreover, the excessive loading by 1000 produced a huge overshoot helicopter position. it indicated that weighting on cost matrices was only effective for certain values in the real experiment, and if it is exaggerated on weighting, it would decrease the accuracy. figure 8. steps response of roll angle at -10° point figure 9. steps response of yaw angle at -10° point j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 107 fascinating graphs occurred in figure 9 which the r weighting variation evidently took effect to ɣ angle. the peaks of step response on ɣ angle before 5 s followed the amount of r weighting, which suited the lqr objective. the smaller error at 20 s, e(t), tended to be caused by the larger proportion of r angle variation, except for the 1000 weight condition. next, the larger control r angle at 0° and 10° has already given the data in figure 11, figure 12, figure 13, and figure 14. although the vast weighting of lqr calculation by 1000 has successfully gotten asymptotic stable at -10°, which errors tend to zero in the time domain, it was not stable for higher angle position by 0° and 10°, respectively. the results characteristic at 10° was not different from the behaviour at 0°. moreover, the overloading by 1000 scale conducted the unstable bicopter position on both angle points. this case indicated that the weighting factor in the lqr algorithm had limited effectiveness in the actual experiment. for instance, when roll angle was treated by significant cost matrices factor (10) and weighting variation, it should not produce a larger overshoot by heavier weight as the lqr algorithm [26]. the not optimal result would be achieved, but the worst outcome would be treated by excessive weighting. the control inputs in equation (12), for example in 0° point, should be observed further to analyze the cause of overshoot and unstable plant. condition of control inputs from amplifier voltage could explain how the overshoots occurred in the bicopter plant in figure 15. moreover, an unstable plant might happen because of the saturated signal by 1000 scale. here is table 2, which resumed error for only yaw angle because whole roll position points, except in 1000 weight, have achieved zero errors in asymptotic stability for 20 s. the overshoot values and their errors should be investigated not only on cost weighting variation of lqr calculation but also by variation of measured control angle position, as tabulated in table 3 and table 4. table 1. symbols description parameter symbol value (unit) roll angle r(t) ° (degree) pitch angle p(t) ° yaw angle ɣ(t) ° initial error ei(t) ° final error ef(t) ° error e(t) ° gravitation acceleration g 9.81 m/s2 thrust force ft n thrust torque τw n.m weight w n torque because of gravitation τt n.m counterweight mass mw 1.87 kg front motor mass mf 0.575 kg back motor mass mb 0.575 kg distance between yaw axis and helicopter body lw 0.4699 m distance between yaw axis and counterweight la 0.6604 m distance between pitch axis and each motor lh 0.1778 m motor force-thrust constant kf 0.1188 n/volt gain constant in two rows and eight columns k2x8 volt quiescent voltage for motor vo volt state vector x state matrix a input matrix b output matrix c feedforward matrix d time t second (s) state-feedback gain k performance index function j cost matrix q weighting matrix r weighting matrix n constant in n matrix c front motor voltage vf volt back motor voltage vb volt proportional gain coefficient kp integral gain coefficient ki derivative gain coefficient kd figure 10. lqr optimization calculation of cost matrices weighting to minimize error or maximize accuracy table 2. errors analysis of cost matrices variation on lqr algorithm weighting variation yaw control angle -10° 0° 10° 25 4.92° 2.46° 1.27° 50 4.17° 3.08° 1.76° 75 4.17° 1.93° 3.08° 100 4.61° 1.89° 2.15° 200 4.44° 2.81° 1.63° table 3. overshoot evaluation of cost matrices variation on lqr algorithm weighting variation overshoot at measured control angle position r ɣ -10° 0° 10° -10° 0° 10° 25 -2.01° 9.59° 21.98° 5.32° 9.59° 21.98° 50 -2.01° 10.12° 22.69° 5.54° 10.12° 22.69° 75 -1.66° 10.64° 23.13° 5.76° 10.64° 23.13° 100 -1.84° 11.00° 23.56° 5.27° 11.00° 23.56° 200 -0.69° 12.49° 24.88° 4.97° 12.49° 24.88° 1000 2.21° 17.15° 27.06° 9.93° 17.15° 27.06° j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 108 overshoot errors mean that difference between overshoot point and the set angle. mean square error (mse) is the one of performances index to assess the accuracy of experimental results [27]. the purpose of lqr theory is to minimize the cost function, namely error in this case, which can be easier to be investigated by mse equation (22). table 4. overshoot errors investigation weighting variation overshoot errors r ɣ -10° 0° 10° -10° 0° 10° 25 7.99° 9.59° 11.98° 15.32° 9.59° 11.98 50 7.99° 10.12° 12.69° 15.54° 10.12° 12.69 75 8.34° 10.64° 13.13° 15.76° 10.64° 13.13 100 8.16° 11.00° 13.56° 15.27° 11.00° 13.56 200 9.31° 12.49° 14.88° 14.97° 12.49° 14.88 1000 12.21° 17.15° 17.06° 19.93° 17.15° 17.06 figure 11. steps response of roll angle at 0° point figure 12. steps response of yaw angle at 0° point j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 109 2))t( n 1i e( n 1 mse ∑ = = (22) in this case, the minimum cost function, which was errors, was required to achieve optimal accuracy because the measurement accuracy [21] was essential to assure flight safety. interestingly, errors in yaw angle measurement in table 2 indicated that the lower angle position got the higher errors. on the other hand, overshoot errors were larger in a higher angle position in table 3, which is described for roll and yaw angles in figure 16 and figure 17, respectively. furthermore, the mse calculations have different results for various measuring points in table 5. nevertheless, the higher weighting tends to yield larger mse values. a fascinating event occurred between overshoot errors and weighting, which had excellent linearity by r2 over 0.9. additionally, the measuring point of 0° achieved the best linearity because it got r2=0.9922 both in roll and yaw angles. the good linearity of both relations might link to the “linear” term of lqr knowledge, particularly in equation (13). these findings can develop an accurate take-off position of bicopter uavs according to their needs for future research. the possibility problem was in this case, which achieved the majority of asymptotic figure 13. steps response of roll angle at 10° point figure 14. steps response of yaw angle at 10° point j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 110 stability because roll angle control position directly corresponded to the primary disturbance of gravitation acceleration, g, as equation (4) (see figure 3 and figure 7). nevertheless, yaw angle errors had an indirect connection to gravitation disturbance so that it produced different results, which took various errors. these observations could inspire building modification method on the lqr technique for accurately hovering bicopter. figure 15. control inputs figure 16. overshoot errors of roll angle relation to weighting variation in different angle position figure 17. overshoot errors of yaw angle relation to weighting variation in different angle position j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 111 table 5. mean square error analysis weighting variation mean square error r ɣ -10° 0° 10° -10° 0° 10° 25 12.79° 31.98° 62.01° 24.70° 28.55° 23.04° 50 12.76° 31.86° 64.29° 24.45° 30.27° 32.56° 75 12.56° 32.55° 63.89° 24.20° 34.06° 30.33° 100 12.64° 31.93° 63.42° 23.42° 26.52° 26.63° 200 12.97° 33.85° 64.78° 21.30° 28.26° 28.48° 1000 16.52° 131.08° 155.96° 35.89° 1688.3° 1105° iv. conclusion experimental data from the bicopter simulator described that the proposed lqr algorithm has successfully controlled angle rotation through pid gains since the heavier weighting factor yielded a more accurate yaw angle. moreover, the roll control angle achieved asymptotic stability, although it produced large overshoots. overshoot errors tend to have a linear relation with the weighting variation of lqr cost matrices, particularly for higher angle positions. despite that, the excessive weighting on controlling roll angle rotation even gave unexpected results, which the larger weight provided the less accurate plant. in addition, the higher weighting tends to produce the larger mse values. the direct interference from gravitation may cause the difference in the lqr algorithm on flight control optimization between yaw and roll rotation angle. the modified control design and lqr algorithm challenge future research to optimize this uav position control, especially accuracy optimization. acknowledgements the authors are grateful to the management of the national research and innovation agency of republic indonesia and murdoch university for supporting this research. declarations author contribution j.a. prakosa: writing original draft, writing review & editing, conceptualization. h. wang: conceptualization, review & editing. e. kurniawan: formal analysis, conceptualization, investigation s. agmal: visualization, validation, data curation. m.j. kholili: resources, validation. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] g. nugroho, z. taha, t. s. nugraha, and h. hadsanggeni, “development of a fixed wing unmanned aerial vehicle (uav) for disaster area monitoring and mapping, ” j. mechatronics, electr. power, veh. technol., vol. 6, no. 2, pp. 83–88, 2015. [2] j. a. prakosa, d. v. samokhvalov, g. r. v. ponce, and f. s. almahturi, “speed control of brushless dc motor for quad copter drone ground test,” 2019 ieee conference of russian young researchers in electrical and electronic engineering (eiconrus), 2019. [3] j. a. prakosa, a. gusrialdi, e. kurniawan, a. d. stotckaia, h. adinanta, and others, “ experimentally robustness improvement of dc motor speed control optimization by hinfinity of mixed-sensitivity synthesis,” int. j. dyn. control, pp. 1–13, 2022. [4] i. k. mohammed and a. i. abdulla, “elevation, pitch and travel axis stabilization of 3dof helicopter with hybrid control system by ga-lqr based pid controller, ” int. j. electr. comput. eng., vol. 10, no. 2, p. 1868, 2020. [5] g. nugroho and d. dectaviansyah, “design, manufacture and performance analysis of an automatic antenna tracker for an unmanned aerial vehicle (uav), ” j. mechatronics, electr. power, veh. technol., vol. 9, no. 1, pp. 32–40, 2018. [6] f. r. triputra, b. r. trilaksono, t. adiono, r. a. sasongko, and m. dahsyat, “ nonlinear dynamic modeling of a fixed-wing unmanned aerial vehicle: a case study of wulung, ” j. mechatronics, electr. power, veh. technol., vol. 6, no. 1, pp. 19–30, 2015. [7] j. hu and h. gu, “survey on flight control technology for large-scale helicopter,” int. j. aerosp. eng., 2017. [8] j. a. prakosa, e. kurniawan, h. adinanta, s. suryadi, and m. i. afandi, “ kajian eksperimen teknik kontrol penerbangan posisi tinggal landas drone bikopter dengan metode pid,” j. otomasi kontrol dan instrumentasi, vol. 12, no. 2, pp. 1–8, 2020. [9] j. apkarian, m. lévis, and c. fulford, “laboratory guide: 3 dof helicopter experiment for labview users, ” markham: quanser, 2012. [10] o. saleem, “an enhanced adaptive-lqr procedure for underactuated systems using relative-rate feedback to dynamically reconfigure the state-weighting-factors,” j. vib. control, p. 10775463221078654, 2022. [11] u. m. guzey, e. h. copur, s. ozcan, a. c. arican, b. m. kocagil, and m. u. salamci, “experiment of sliding mode control with nonlinear sliding surface design for a 3-dof helicopter model,” in 2019 xxvii international conference on information, communication and automation technologies (icat), pp. 1–6, 2019. [12] e. kurniawan, h. wang, b. h. sirenden, j. a. prakosa, h. adinanta, and s. suryadi, “discrete-time modified repetitive sliding mode control for uncertain linear systems,” int. j. adapt. control signal process., vol. 35, no. 11, pp. 2245–2258, 2021. https://mev.lipi.go.id/ https://doi.org/10.14203/j.mev.2015.v6.83-88 https://doi.org/10.14203/j.mev.2015.v6.83-88 https://doi.org/10.14203/j.mev.2015.v6.83-88 https://doi.org/10.14203/j.mev.2015.v6.83-88 https://doi.org/10.14203/j.mev.2015.v6.83-88 https://doi.org/10.1109/eiconrus.2019.8656647 https://doi.org/10.1109/eiconrus.2019.8656647 https://doi.org/10.1109/eiconrus.2019.8656647 https://doi.org/10.1109/eiconrus.2019.8656647 https://doi.org/10.1109/eiconrus.2019.8656647 https://doi.org/10.1007/s40435-022-00956-y https://doi.org/10.1007/s40435-022-00956-y https://doi.org/10.1007/s40435-022-00956-y https://doi.org/10.1007/s40435-022-00956-y https://doi.org/10.1007/s40435-022-00956-y http://doi.org/10.11591/ijece.v10i2.pp1868-1884 http://doi.org/10.11591/ijece.v10i2.pp1868-1884 http://doi.org/10.11591/ijece.v10i2.pp1868-1884 http://doi.org/10.11591/ijece.v10i2.pp1868-1884 https://doi.org/10.14203/j.mev.2018.v9.32-40 https://doi.org/10.14203/j.mev.2018.v9.32-40 https://doi.org/10.14203/j.mev.2018.v9.32-40 https://doi.org/10.14203/j.mev.2018.v9.32-40 https://doi.org/10.14203/j.mev.2015.v6.19-30 https://doi.org/10.14203/j.mev.2015.v6.19-30 https://doi.org/10.14203/j.mev.2015.v6.19-30 https://doi.org/10.14203/j.mev.2015.v6.19-30 https://doi.org/10.14203/j.mev.2015.v6.19-30 https://doi.org/10.1155/2017/5309403 https://doi.org/10.1155/2017/5309403 https://doi.org/10.5614/joki.2020.12.2.1 https://doi.org/10.5614/joki.2020.12.2.1 https://doi.org/10.5614/joki.2020.12.2.1 https://doi.org/10.5614/joki.2020.12.2.1 https://doi.org/10.5614/joki.2020.12.2.1 https://www.made-for-science.com/de/quanser/?df=made-for-science-quanser-3-dof-helicopter-coursewarestud-labview.pdf https://www.made-for-science.com/de/quanser/?df=made-for-science-quanser-3-dof-helicopter-coursewarestud-labview.pdf https://www.made-for-science.com/de/quanser/?df=made-for-science-quanser-3-dof-helicopter-coursewarestud-labview.pdf https://doi.org/10.1177%2f10775463221078654 https://doi.org/10.1177%2f10775463221078654 https://doi.org/10.1177%2f10775463221078654 https://doi.org/10.1177%2f10775463221078654 https://doi.org/10.1109/icat47117.2019.8938941 https://doi.org/10.1109/icat47117.2019.8938941 https://doi.org/10.1109/icat47117.2019.8938941 https://doi.org/10.1109/icat47117.2019.8938941 https://doi.org/10.1109/icat47117.2019.8938941 https://doi.org/10.1002/acs.3316 https://doi.org/10.1002/acs.3316 https://doi.org/10.1002/acs.3316 https://doi.org/10.1002/acs.3316 https://doi.org/10.1002/acs.3316 j.a. prakosa et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 101-112 112 [13] w. xu, h. peng, l. yang, and x. zhu, “robust attitude control of a 3-dof helicopter prototype subject to wind disturbance and communication delay,” trans. inst. meas. control, vol. 43, no. 13, pp. 3071–3081, 2021. [14] t. dezhi and t. xiaojun, “design of uav attitude controller based on improved robust lqr control,” in 2017 32nd youth academic annual conference of chinese association of automation (yac), pp. 1004–1009, 2017. [15] x. yang and x. zheng, “adaptive nn backstepping control design for a 3-dof helicopter: theory and experiments,” ieee trans. ind. electron., vol. 67, no. 5, pp. 3967–3979, 2019. [16] x. zhu and d. li, “ robust attitude control of a 3-dof helicopter considering actuator saturation, ” mech. syst. signal process., vol. 149, p. 107209, 2021. [17] m. n. setiawan, e. r. suryana, l. parytta, and w. andaro, “pole placement and lqr implementation on longitudinal altitute holding control of wing in surface effect vehicle, ” j. mechatronics, electr. power, veh. technol., vol. 11, no. 2, pp. 86–94, 2020. [18] e. joelianto, d. christian, and a. samsi, “swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm,” j. mechatronics, electr. power, veh. technol., vol. 11, no. 1, pp. 1–10, 2020. [19] s. bai and p. chirarattananon, “splitflyer air: a modular quadcopter that disassembles into two bicopters mid-air,” ieee/asme trans. mechatronics, 2022. [20] n. l. manuel, n. inanç, and m. y. erten, “control of mobile robot formations using a-star algorithm and artificial potential fields,” j. mechatronics, electr. power, veh. technol., vol. 12, no. 2, pp. 57–67, 2021. [21] j. a. prakosa, a. v. putov, and a. d. stotckaia, “measurement uncertainty of closed loop control system for water flow rate,” 2019 xxii international conference on soft computing and measurements (scm), 2019. [22] p. das, r. k. mehta, and o. p. roy, “optimized methods for the pre-eminent performance of lqr control applied in a mimo system,” int. j. dyn. control, vol. 7, no. 4, pp. 1501–1520, 2019. [23] n. van chi, “adaptive feedback linearization control for twin rotor multiple-input multiple-output system,” int. j. control. autom. syst., vol. 15, no. 3, pp. 1267–1274, 2017. [24] y. y. nazaruddin, i. g. n. a. i. mandala, and others, “ optimisasi pengontrol lqr menggunakan algoritma stochastic fractal search,” in seminar nasional instrumentasi, kontrol dan otomasi, pp. 235–240, 2018. [25] a. iannelli and r. s. smith, “a multiobjective lqr synthesis approach to dual control for uncertain plants,” ieee control syst. lett., vol. 4, no. 4, pp. 952–957, 2020. [26] m. farjadnasab and m. babazadeh, “model-free lqr design by q-function learning,” automatica, vol. 137, p. 110060, 2022. [27] l. li, y. liu, z. yang, x. yang, and k. li, “mean-square error constrained approach to robust stochastic iterative learning control,” iet control theory & appl., vol. 12, no. 1, pp. 38–44, 2018. https://doi.org/10.1177%2f01423312211021294 https://doi.org/10.1177%2f01423312211021294 https://doi.org/10.1177%2f01423312211021294 https://doi.org/10.1177%2f01423312211021294 https://doi.org/10.1109/yac.2017.7967557 https://doi.org/10.1109/yac.2017.7967557 https://doi.org/10.1109/yac.2017.7967557 https://doi.org/10.1109/yac.2017.7967557 https://doi.org/10.1109/tie.2019.2921296 https://doi.org/10.1109/tie.2019.2921296 https://doi.org/10.1109/tie.2019.2921296 https://doi.org/10.1016/j.ymssp.2020.107209 https://doi.org/10.1016/j.ymssp.2020.107209 https://doi.org/10.1016/j.ymssp.2020.107209 https://doi.org/10.14203/j.mev.2020.v11.86-94 https://doi.org/10.14203/j.mev.2020.v11.86-94 https://doi.org/10.14203/j.mev.2020.v11.86-94 https://doi.org/10.14203/j.mev.2020.v11.86-94 https://doi.org/10.14203/j.mev.2020.v11.86-94 https://doi.org/10.14203/j.mev.2020.v11.1-10 https://doi.org/10.14203/j.mev.2020.v11.1-10 https://doi.org/10.14203/j.mev.2020.v11.1-10 https://doi.org/10.14203/j.mev.2020.v11.1-10 https://doi.org/10.1109/tmech.2022.3164886 https://doi.org/10.1109/tmech.2022.3164886 https://doi.org/10.1109/tmech.2022.3164886 https://doi.org/10.14203/j.mev.2021.v12.57-67 https://doi.org/10.14203/j.mev.2021.v12.57-67 https://doi.org/10.14203/j.mev.2021.v12.57-67 https://doi.org/10.14203/j.mev.2021.v12.57-67 https://doi.org/10.1109/scm.2019.8903681 https://doi.org/10.1109/scm.2019.8903681 https://doi.org/10.1109/scm.2019.8903681 https://doi.org/10.1109/scm.2019.8903681 https://doi.org/10.1007/s40435-019-00587-w https://doi.org/10.1007/s40435-019-00587-w https://doi.org/10.1007/s40435-019-00587-w https://doi.org/10.1007/s40435-019-00587-w https://doi.org/10.1007/s12555-015-0245-2 https://doi.org/10.1007/s12555-015-0245-2 https://doi.org/10.1007/s12555-015-0245-2 https://instrument.itb.ac.id/wp-content/uploads/sites/335/2019/02/32-optimisasi-pengontrol-lqr-menggunakan-algoritma-stochastic-fractal-search.pdf https://instrument.itb.ac.id/wp-content/uploads/sites/335/2019/02/32-optimisasi-pengontrol-lqr-menggunakan-algoritma-stochastic-fractal-search.pdf https://instrument.itb.ac.id/wp-content/uploads/sites/335/2019/02/32-optimisasi-pengontrol-lqr-menggunakan-algoritma-stochastic-fractal-search.pdf https://instrument.itb.ac.id/wp-content/uploads/sites/335/2019/02/32-optimisasi-pengontrol-lqr-menggunakan-algoritma-stochastic-fractal-search.pdf https://doi.org/10.1109/lcsys.2020.2997085 https://doi.org/10.1109/lcsys.2020.2997085 https://doi.org/10.1109/lcsys.2020.2997085 https://doi.org/10.1016/j.automatica.2021.110060 https://doi.org/10.1016/j.automatica.2021.110060 https://doi.org/10.1016/j.automatica.2021.110060 https://doi.org/10.1049/iet-cta.2017.0546 https://doi.org/10.1049/iet-cta.2017.0546 https://doi.org/10.1049/iet-cta.2017.0546 https://doi.org/10.1049/iet-cta.2017.0546 introduction ii. materials and methods a. design and method b. proposed cost matrices variation of lqr algorithm iii. results and discussions iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.95-100 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: z. saputra et al., “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 95-100, july 2022. carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite zanu saputra a, *, robeth viktoria manurung b, aminuddin debataraja c, muhammad iqbal nugraha a, tien-fu lu d a electrical engineering and informatics department, politeknik manufaktur negeri bangka belitung kawasan industri air kantung sungailiat, bangka, 33211, indonesia b research center for telecommunication, national research and innovation agency (brin) jl. sangkuriang-komplek lipi gedung 20, bandung 40135, indonesia c electrical engineering, state polytechnic of jakarta jl. prof. dr. g. a. siwabessy, kampus universitas indonesia, depok, 16425, indonesia d mechanical engineering, the university of adelaide adelaide, south australia, 5005, australia received 6 august 2021; 1st revision 30 may 2022; 2nd revision 1 june 2022; 3rd revision 13 june 2022; accepted 15 june 2022; published online 29 july 2022 abstract this paper concerns enhancing a lead detection sensor using a combination of polypyrrole (ppy), nafion (n), and ionic liquid (il) with thick-film or screen-printing technology on sensitive material-based carbon electrodes. electrode characterization using a scanning electron microscope (sem) was conducted to see the morphology of sensitive materials, showing that the spherical particles were distributed evenly on the electrode surface. analysis using energy dispersive spectroscopy (eds) shows that the element's atomic composition is 84.92 %, 8.81 %, 6.26 %, and 0.01 % for carbon, nitrogen, oxygen, and bismuth, respectively. potentiostat measurement with the ambient temperature of 25 °c on a standard lead solution with concentration ranging from 0.05 to 0.5 mg/l yields an average output voltage ranging from 2.16 to 2.27 v. it can be concluded that the sensor is able to detect lead with a sensitivity of 0.21 v in each addition of solution concentration (mg/l) and give an 84 % concentration contribution to the voltage. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: lead detection; thick film; polypyrrole; nafion; ionic liquid. i. introduction lead substances can be found in many places, including food and agricultural products such as fruits and vegetables. the lead substance in the body could inhibit the photosynthesis rate, change the shape of cells, reduce the size of cells, hinder the growth rate of children, cause muscle pain, damage the nerves of the brain, weaken liver function, and damage the kidneys until death [1][2][3]. therefore, it is critical and a source of worry for researchers to identify lead content in environmental, dietary, and bioassays. lead content assays, such as atomic absorption spectrophotometry [4][5][6], differential pulse anodic stripping voltammetry (dpasv) [7][8][9], and square wave anodic stripping voltammetry [10][11][12], continue to be effectively developed. due to their affordability, ease of use, great stability, high sensitivity, and low detection limits, electrochemical techniques, particularly electropolymerization, have gained widespread acceptance as electrode coatings for heavy metal detection sensors [13][14][15]. the advantages of mercury film-based electrodes (mfe) [16][17], such as their surface cleanliness, repeatability, high sensitivity, and high hydrogen potential, have led to their application in electrode coating processes [18][19]. the issue is that mercury is a harmful substance. the use of bismuth films (bif), a different technique established in this field, has electrode coating properties that are nearly identical to those * corresponding author. +62-81959750225 e-mail address: zanu@polman-babel.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.95-100 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.95-100 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.95-100&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ z. saputra et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 96 of mercury electrode coating. electro polymerization was used to create bif at electrodes such as glass carbon electrode (gce) [20][21][22], carbon paste electrode (cpe) [23][24][25], boron-doped diamond electrode (bdde) [26][27][28], and carbon electrodes with screen printing [29][30]. in this study, the thick film-based spce method for producing electrodes was selected after taking process time and production costs into account. polypyrrole (ppy) is a conductive polymer with electrical properties that are widely used as sensor materials. ppy can be synthesized to have electrical conductivity up to 1000 s/cm, which is close to metal conductivity [31][32][33]. in addition, ppy can be deposited on a carbon electrode by an electro polymerization method so that the pyrrole precipitates form a sensitive membrane of the sensor. an electrochemical solution and electrode modifier with a high ionic conductivity, ionic liquid (il) is frequently employed in the production of sensors [34][35][36]. to increase the sensitivity of heavy metal detection, nafion (n), a material with great anti-pollution capacity, chemical inertia, and high permeability to pertinent cations [37][38], is used. this study used an electro polymerization approach to modify the spce electrode by covering it with ppy on a working electrode. synergistic effects can be produced in electrochemical applications by combining il and n composites. a further benefit of adding bif to the working electrode is that it becomes stronger and more effective in detecting heavy metals. lastly, utilizing a scanning electron microscope for morphological inspection and potentiostat analysis, this straightforward, inexpensive, and sensitive sensor is used to estimate the pb (ii) level scanning electron microscope (sem). ii. materials and methods a. tools and materials the accu-coat 3230 screen printer uses the carbon (c) paste and silver chloride electrode (ag|agcl) printing technique. following printing, the materials are dried in an oven for 10 minutes at 150 °c before continuing with the sintering procedure on a conveyor furnace machine radiant technology corp (rtc) tf 315 for 30 minutes at 800 °c. using a potentiostat of the soliton em 10/20appa 505 type and a digital multimeter linked to a computer via usb cable for the purpose of presenting the measurement's results, the sensor response to pb (ii) concentration is measured. as the working electrode (positive electrode) and reference electrode (negative electrode), respectively, materials were ag|agcl material of the dupont 5874 type and carbon paste of the dupont bq242 type. aldrich 109-97-7 materials that had been refined with aluminum oxide were employed in conductive ppy. ammonium hydrogen phosphate serves as an anion in this process. 3dimethylimidazolium tetrafluoroborate, nafion d521, and n-dimethylformamide were combined to create 1-butyl-2, which was employed by ionic liquid (il) (dmf). in the liquid tester, pb (ii) standard solution in a 1000 mg/l concentration is used. b. fabrication of electrodes electrodes for lead detection sensor are produced using thick film technology based on the screenprinting technique. this method was applied to create a microelectronics circuit with the benefit of rescaling the sensor's size using tiny conductor lines. in this study, a layer thickness of 100 micrometers is used. while ag|agcl paste is used to create working electrodes and counters, printing carbon paste is utilized to create reference electrodes. the production of screen films, printing of paste ingredients, drying, combustion, assembly, and packing are the steps of the electrode fabrication process used in this study. the process flow for fabricating electrodes is shown in figure 1. c. electro polymerization of pyrrole the amount of 1 m pyrrole (c4h5n) was purified using aluminum oxide powder and a 0.1 m concentration of (nh4)2hpo4 was prepared. all these substances were dissolved into 17 ω distilled water and supplied with nitrogen, blown through a tube, for 5 minutes. the electrochemical process was carried out for the polymerization process on carbon electrodes using ammonium hydrogen phosphate. the electropolymerization process was conducted for 10 minutes, powered by a voltage of 1 volt and at a constant current of 450 650 µa. nitrogen was also simultaneously supplied, which is blown through a tube during the electro polymerization process. d. nafion and ionic liquid coating after electro polymerization, the working electrode was coated with a solution consisting of 0.1 % nafion and 0.5 % ionic liquid dissolved in 1 ml of dmf. afterwards, the electrode was dried naturally at room temperature. a reference voltage measurement was performed with the electrode submerged in a 3 m solution of potassium chloride (kcl) to check the electrode's voltage stability. e. bismuth film electro polymerization electro polymerization is used to create the bismuth film coating on the working electrode. a 0.1 m acetate buffer solution with a ph of 4.5 and 200 × 10-9 g m bi (iii) make up the electro polymerization solution. this solution is combined, agitated, and exposed to a -1.4 v voltage for 2 minutes. the sensor electrode is subjected to an screen film making printing of paste material drying firing assembling packaging figure 1. electrode fabrication process z. saputra et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 97 amperometry measurement in order to assess and characterize the sensor in accordance with several pb standard solutions. figure 2 depicts the sensitive membrane doping procedure. with a 20 k secondary electron enlargement and a 10 kv scan electron microscope (sem su3500), morphological properties were examined. prior to and following the application of the conductive material coating, spce was subjected to tests. a potentiostat was used to regulate the electrodes and electroanalytically measure the experiment while testing the sensor electrode's performance. a 700 mv source voltage and a 1 kω resistance were employed. iii. results and discussions a. sem-based electrode characterization prior to being coated with conductive material, the morphological properties of spce are shown in figure 3(a), with the carbon layer predominating the spce's surface. in figure 3(b), after electrodeposition, the morphology indicates that the particles are dispersed evenly throughout all of the working electrode's surfaces. in addition, the testing aims to see the electrode layer's composition includes bismuth, nitrogen, carbon, and oxygen. after testing was carried out using energy dispersive spectroscopy (eds) to give the model and make of the spectroscopy, it was discovered that c, nitrogen, oxygen, and bismuth, respectively, have atomic compositions of 84.92 %, 8.81 %, 6.26 %, and 0.01 %. further information regarding the composition of each element after eds testing can be seen in table 1, which shows that carbon elements are more dominant than other elements. this composition gives a good relationship to the specifications of the electrode. b. electrochemical characterization of electrodes 1) stability of reference electrodes to maintain the voltage stability created by working electrodes and counter electrodes, reference electrode ag|agcl is utilized. figure 4 displays the results of the reference voltage test. a 3 m concentration of kcl electrolyte solution is used for testing. the dispersion of the kcl solution, which is not equally distributed on the electrode surface, causes a drop in voltage in quadrant i. in contrast, the output responses are more consistent in quadrant ii. this result demonstrates that the electrode's output voltage has good stability, ranging from 2.02 to 2.5 mv, demonstrating that the electrode is capable of detecting pb (ii) material. 2) observation of bismuth electro polymerization currents figure 2. the process of sensitive membranes doping (a) (b) figure 3. sem micrograph of electrode carbon: (a) before electrodeposition; (b) after electrodeposition and added with ppy we re ce spce we re ce electrodeposition pyrrole we re ce n / il composite solution ce we re electrodeposition bismuth-film i z. saputra et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 98 the bismuth films are deposited by electrodeposition, which is used to boost the sensor electrode's conductivity. the voltage used in the electrodeposition process is -1.4 v so that bismuth precipitation occurs on the surface of the working electrode. figure 5 shows the electrodeposition current of the working electrode coated with bismuth film at 0.08 to 0.064 ma during the 2minute process. the graph shows that the passing current gradually decreased over the period, meaning that the electrical resistance of the electrolyte kept increasing during the period. the results of the redox reaction in the electrodeposition process work well as the electrode surface can be coated with bismuth film. the amount of bismuth film deposits is directly proportional to the electric current flowing in the electrolyte. 3) lead electrochemical detection the pb substance test output voltage using a typical pb solution is shown in figure 6. the 0.05, 0.1, 0.25, and 0.5 mg/l variations made up the produced test concentration. each sample test solution's average output voltages are 2.16, 2.21, 2.23, and table 1. result of energy dispersive spectroscopy (eds) testing element weight (%) atomic (%) error (%) net int. k ratio z a f carbon 81.90 84.92 3.09 2685.16 0.6988 1.0071 0.8473 1 nitrogen 9.91 8.81 21.95 38.76 0.0062 0.98 0.0643 1 oxygen 8.05 6.26 17.31 76.07 0.0070 0.9567 0.0912 1 bismuth 0.14 0.01 27.17 6.47 0.0014 0.5299 1.8243 0.9969 figure 4. output response of ag|agcl electrode 2.00 2.05 2.10 2.15 2.20 2.25 2.30 2.35 2.40 2.45 2.50 2.55 2.60 v o lt ag e (v ) time electro disposition (s) figure 5. bismuth electrodeposition time y = -0.0006x + 0.0775 r² = 0.9682 0.0600 0.0620 0.0640 0.0660 0.0680 0.0700 0.0720 0.0740 0.0760 0.0780 0.0800 c u rr en t (m a ) time (s) z. saputra et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 99 2.27 v for 0.05, 0.1, 0.25, and 0.5 mg/l, respectively. the highest voltage difference occurs between 0.05 mg/l test solution and 0.1 mg/l test solution with a difference of 0.06 v. the linearity of these output voltages is 84.1 %, demonstrating that the sensor is able to accurately detect pb (ii) concentration. iv. conclusion according to this research, bismuth films were used to successfully deposit polypyrrole on carbon electrodes and dope it with ionic liquid and nafion. the morphology of the working electrode's surface as revealed by sem demonstrates that the particles are dispersed uniformly on all surfaces, indicating that the contributions of carbon and other composite materials have improved the conductivity of ppy, n, il, bi, and spce. with a voltage range of 2.02 to 2.5 mv, the reference electrode's voltage stability has produced positive results. after the bismuth film was deposited using electrodeposition for 2 minutes, the sensor electrode's sensitivity was increased. the electrode was subjected to galvanostatic potential, and the results of the measurements revealed that the electrode had an 84.1 % linear response. averaging between 2.16 and 2.27 v, the measured detection limits range from 0.05 to 0.5 mg/l concentrations. based on performance, it is apparent that the sensor can effectively detect pb (ii) compounds and that it may be employed as a working electrode for pb (ii) substance sensors. acknowledgments the authors would like to thank the research center for electronics and telecommunication, indonesian institute of sciences (lipi), bandung, and other parties that cannot be mentioned one by one who has shared their expertise and insights regarding details of the research materials, as well as for many helpful discussions. declarations author contribution z. saputra is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] y. tu, s. ju, and p. wang, “flame atomic absorption spectrometric determination of copper, lead, and cadmium in gastrodiae rhizoma samples after preconcentration using magnetic solid-phase extraction,” spectrosc. lett., vol. 49, no. 4, 2016. [2] s. hamida, l. ouabdesslam, a. f. ladjel, m. escudero, and j. anzano, “determination of cadmium, copper, lead, and zinc in pilchard sardines from the bay of boumerdés by atomic absorption spectrometry,” anal. lett., vol. 51, no. 16, 2018. [3] b. debnath, w. singh, and k. manna, “sources and toxicological effects of lead on human health,” indian j. med. spec., vol. 10, no. 2, 2019. [4] é. m. m. flores et al., “determination of cd and pb in medicinal plants using solid sampling flame atomic absorption spectrometry,” int. j. environ. anal. chem., vol. 89, no. 2, 2009. [5] e. l. silva and p. dos s. roldan, “simultaneous flow injection preconcentration of lead and cadmium using cloud point extraction and determination by atomic absorption spectrometry,” j. hazard. mater., vol. 161, no. 1, 2009. [6] b. sisay, e. debebe, a. meresa, and t. abera, “analysis of cadmium and lead using atomic absorption spectrophotometer in roadside soils of jimma town,” j. anal. pharm. res., vol. 8, no. 4, 2019. [7] z. su et al., “thiol-ene chemistry guided preparation of thiolated polymeric nanocomposite for anodic stripping voltammetric analysis of cd2+ and pb 2+,” analyst, vol. 138, no. 4, 2013. [8] m. ghanei-motlagh and m. baghayeri, “determination of trace tl(i) by differential pulse anodic stripping voltammetry using a novel modified carbon paste electrode,” j. electrochem. soc., vol. 167, no. 6, 2020. [9] y. zhang, c. li, y. su, w. mu, and x. han, “simultaneous detection of trace cd(ii) and pb(ii) by differential pulse anodic stripping voltammetry using a bismuth oxycarbide/nafion electrode,” inorg. chem. commun., vol. 111, 2020. figure 6. the responses of pb sensor y = 0.2133x + 2.1691 r² = 0.8414 2.14 2.16 2.18 2.20 2.22 2.24 2.26 2.28 2.30 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 linearity = 84.1% pb consentration (mg/l) o u tp u t vo ta ge ( v ) https://mev.lipi.go.id/ https://doi.org/10.1080/00387010.2015.1134578 https://doi.org/10.1080/00387010.2015.1134578 https://doi.org/10.1080/00387010.2015.1134578 https://doi.org/10.1080/00387010.2015.1134578 https://doi.org/10.1080/00387010.2015.1134578 https://doi.org/10.1080/00032719.2018.1434537 https://doi.org/10.1080/00032719.2018.1434537 https://doi.org/10.1080/00032719.2018.1434537 https://doi.org/10.1080/00032719.2018.1434537 https://doi.org/10.4103/injms.injms_30_18 https://doi.org/10.4103/injms.injms_30_18 https://doi.org/10.4103/injms.injms_30_18 https://doi.org/10.1080/03067310802578945 https://doi.org/10.1080/03067310802578945 https://doi.org/10.1080/03067310802578945 https://doi.org/10.1016/j.jhazmat.2008.03.100 https://doi.org/10.1016/j.jhazmat.2008.03.100 https://doi.org/10.1016/j.jhazmat.2008.03.100 https://doi.org/10.1016/j.jhazmat.2008.03.100 https://doi.org/10.15406/japlr.2019.08.00329 https://doi.org/10.15406/japlr.2019.08.00329 https://doi.org/10.15406/japlr.2019.08.00329 https://doi.org/10.15406/japlr.2019.08.00329 https://doi.org/10.1039/c2an36114k https://doi.org/10.1039/c2an36114k https://doi.org/10.1039/c2an36114k https://doi.org/10.1039/c2an36114k https://doi.org/10.1149/1945-7111/ab823c https://doi.org/10.1149/1945-7111/ab823c https://doi.org/10.1149/1945-7111/ab823c https://doi.org/10.1149/1945-7111/ab823c https://doi.org/10.1016/j.inoche.2019.107672 https://doi.org/10.1016/j.inoche.2019.107672 https://doi.org/10.1016/j.inoche.2019.107672 https://doi.org/10.1016/j.inoche.2019.107672 z. saputra et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 95-100 100 [10] z. d. anastasiadou, i. sipaki, p. d. jannakoudakis, and s. t. girousi, “square-wave anodic stripping voltammetry (swasv) for the determination of ecotoxic metals, using a bismuth-film electrode,” analytical letters, vol. 44, no. 5. 2011. [11] s. k. pandey, s. sachan, and s. k. singh, “ultra-trace sensing of cadmium and lead by square wave anodic stripping voltammetry using ionic liquid modified graphene oxide,” mater. sci. energy technol., vol. 2, no. 3, 2019. [12] s. e. d. bahinting et al., “bismuth film-coated gold ultramicroelectrode array for simultaneous quantification of pb(ii) and cd(ii) by square wave anodic stripping voltammetry,” sensors, vol. 21, no. 5, 2021. [13] e. nagles, v. arancibia, c. rojas, and r. segura, “nafionmercury coated film electrode for the adsorptive stripping voltammetric determination of lead and cadmium in the presence of pyrogallol red,” talanta, vol. 99, 2012. [14] x. liu, k. venkatraman, and r. akolkar, “communication— electrochemical sensor concept for the detection of lead contamination in water utilizing lead underpotential deposition,” j. electrochem. soc., vol. 165, no. 2, 2018. [15] y. dai and c. c. liu, “a simple, cost-effective sensor for detecting lead ions inwater using under-potential deposited bismuth sub-layer with differential pulse voltammetry (dpv),” sensors (switzerland), vol. 17, no. 5, 2017. [16] j. lara, j. f. torres, o. g. beltrán, e. nagles, and j. hurtado, “simultaneous determination of lead and cadmium by stripping voltammetry using in-situ mercury film glassy carbon electrode coated with nafion-macrocyclic ester,” int. j. electrochem. sci., vol. 12, no. 8, 2017. [17] i. albalawi, a. hogan, h. alatawi, and e. moore, “a sensitive electrochemical analysis for cadmium and lead based on nafion-bismuth film in a water sample,” sens. bio-sensing res., vol. 34, 2021. [18] b. fotovvati, n. namdari, and a. dehghanghadikolaei, “on coating techniques for surface protection: a review,” journal of manufacturing and materials processing, vol. 3, no. 1. 2019. [19] r. i. m. asri, w. s. w. harun, m. a. hassan, s. a. c. ghani, and z. buyong, “a review of hydroxyapatite-based coating techniques: sol-gel and electrochemical depositions on biocompatible metals,” journal of the mechanical behavior of biomedical materials, vol. 57. 2016. [20] a. m. ashrafi and k. vytřas, “codeposited antimony-bismuth film carbon paste electrodes for electrochemical stripping determination of trace heavy metals,” int. j. electrochem. sci., vol. 8, no. 2, 2013. [21] y. dong, y. ding, y. zhou, j. chen, and c. wang, “differential pulse anodic stripping voltammetric determination of pb ion at a montmorillonites/polyaniline nanocomposite modified glassy carbon electrode,” j. electroanal. chem., vol. 717–718, 2014. [22] w. gao, w. w. tjiu, j. wei, and t. liu, “highly sensitive nonenzymatic glucose and h2o2 sensor based on ni(oh)2/electroreduced graphene oxide-multiwalled carbon nanotube film modified glass carbon electrode,” talanta, vol. 120, 2014. [23] o. schlesinger and l. alfonta, “encapsulation of microorganisms, enzymes, and redox mediators in graphene oxide and reduced graphene oxide,” methods in enzymology, vol. 609, 2018. [24] k. e. toghill, g. g. wildgoose, a. moshar, c. mulcahy, and r. g. compton, “fabrication and characterization of a bismuth nanoparticle modified boron doped diamond electrode and its application to the simultaneous determination of cadmium(ii)and lead(ii),” electroanalysis, vol. 20, no. 16, 2008. [25] o. vajdle et al., “use of carbon paste electrode and modified by gold nanoparticles for selected macrolide antibiotics determination as standard and in pharmaceutical preparations,” j. electroanal. chem., vol. 873, 2020. [26] s. chaiyo, e. mehmeti, k. žagar, w. siangproh, o. chailapakul, and k. kalcher, “electrochemical sensors for the simultaneous determination of zinc, cadmium and lead using a nafion/ionic liquid/graphene composite modified screen-printed carbon electrode,” anal. chim. acta, vol. 918, 2016. [27] b. c. lourencao, r. f. brocenschi, r. a. medeiros, o. fatibellofilho, and r. c. rocha-filho, “analytical applications of electrochemically pretreated boron-doped diamond electrodes,” chemelectrochem, vol. 7, no. 6. 2020. [28] m. kowalcze and m. jakubowska, “voltammetric determination of nicotine in electronic cigarette liquids using a boron-doped diamond electrode (bdde),” diam. relat. mater., vol. 103, 2020. [29] a. paukpol and j. jakmunee, “bismuth coated screen-printed electrode platform for greener anodic stripping voltammetric determination of cadmium and lead,” chiang mai univ. j. nat. sci., vol. 15, no. 1, 2016. [30] z. lu, j. zhang, w. dai, x. lin, j. ye, and j. ye, “a screen-printed carbon electrode modified with a bismuth film and gold nanoparticles for simultaneous stripping voltammetric determination of zn(ii), pb(ii) and cu(ii),” microchim. acta, vol. 184, no. 12, 2017. [31] s.-j. lee, n. muthuchamy, a.-i. gopalan, and k.-p. lee, “new nafion/conducting polymer composite for membrane application,” proceedings of the 2016 international conference on advanced materials science and environmental engineering, 2016. [32] t. h. le, y. kim, and h. yoon, “electrical and electrochemical properties of conducting polymers,” polymers, vol. 9, no. 4. 2017. [33] g. g. gagliardi, a. ibrahim, d. borello, and a. el-kharouf, “composite polymers development and application for polymer electrolyte membrane technologies-a review,” molecules, vol. 25, no. 7. 2020. [34] s. c. hamm et al., “ionic conductivity enhancement of sputtered gold nanoparticle-in-ionic liquid electrolytes,” j. mater. chem. a, vol. 2, no. 3, 2014. [35] t. zheng et al., “synthesis and ionic conductivity of a novel ionic liquid polymer electrolyte,” j. polym. res., vol. 21, no. 2, 2014. [36] r. a. segura, j. a. pizarro, m. p. oyarzun, a. d. castillo, k. j. díaz, and a. b. placencio, “determination of lead and cadmium in water samples by adsorptive stripping voltammetry using a bismuth film/1-nitroso-2-napthol/nafion modified glassy carbon electrode,” int. j. electrochem. sci., vol. 11, no. 2, 2016. [37] m. schalenbach, t. hoefner, p. paciok, m. carmo, w. lueke, and d. stolten, “gas permeation through nafion. part 1: measurements,” j. phys. chem. c, vol. 119, no. 45, 2015. [38] l. xiao et al., “simultaneous detection of cd(ii) and pb(ii) by differential pulse anodic stripping voltammetry at a nitrogendoped microporous carbon/nafion/bismuth-film electrode,” electrochim. acta, vol. 143, 2014. https://doi.org/10.1080/00032711003790023 https://doi.org/10.1080/00032711003790023 https://doi.org/10.1080/00032711003790023 https://doi.org/10.1080/00032711003790023 https://doi.org/10.1016/j.mset.2019.09.004 https://doi.org/10.1016/j.mset.2019.09.004 https://doi.org/10.1016/j.mset.2019.09.004 https://doi.org/10.1016/j.mset.2019.09.004 https://doi.org/10.3390/s21051811 https://doi.org/10.3390/s21051811 https://doi.org/10.3390/s21051811 https://doi.org/10.3390/s21051811 https://doi.org/10.1016/j.talanta.2012.05.028 https://doi.org/10.1016/j.talanta.2012.05.028 https://doi.org/10.1016/j.talanta.2012.05.028 https://doi.org/10.1016/j.talanta.2012.05.028 https://doi.org/10.1149/2.0801802jes https://doi.org/10.1149/2.0801802jes https://doi.org/10.1149/2.0801802jes https://doi.org/10.1149/2.0801802jes https://doi.org/10.3390/s17050950 https://doi.org/10.3390/s17050950 https://doi.org/10.3390/s17050950 https://doi.org/10.3390/s17050950 https://doi.org/10.20964/2017.08.65 https://doi.org/10.20964/2017.08.65 https://doi.org/10.20964/2017.08.65 https://doi.org/10.20964/2017.08.65 https://doi.org/10.20964/2017.08.65 https://doi.org/10.1016/j.sbsr.2021.100454 https://doi.org/10.1016/j.sbsr.2021.100454 https://doi.org/10.1016/j.sbsr.2021.100454 https://doi.org/10.1016/j.sbsr.2021.100454 https://doi.org/10.3390/jmmp3010028 https://doi.org/10.3390/jmmp3010028 https://doi.org/10.3390/jmmp3010028 https://doi.org/10.1016/j.jmbbm.2015.11.031 https://doi.org/10.1016/j.jmbbm.2015.11.031 https://doi.org/10.1016/j.jmbbm.2015.11.031 https://doi.org/10.1016/j.jmbbm.2015.11.031 https://doi.org/10.1016/j.jmbbm.2015.11.031 http://www.electrochemsci.org/papers/vol8/80202095.pdf http://www.electrochemsci.org/papers/vol8/80202095.pdf http://www.electrochemsci.org/papers/vol8/80202095.pdf http://www.electrochemsci.org/papers/vol8/80202095.pdf https://doi.org/10.1016/j.jelechem.2014.01.014 https://doi.org/10.1016/j.jelechem.2014.01.014 https://doi.org/10.1016/j.jelechem.2014.01.014 https://doi.org/10.1016/j.jelechem.2014.01.014 https://doi.org/10.1016/j.jelechem.2014.01.014 https://doi.org/10.1016/j.talanta.2013.12.012 https://doi.org/10.1016/j.talanta.2013.12.012 https://doi.org/10.1016/j.talanta.2013.12.012 https://doi.org/10.1016/j.talanta.2013.12.012 https://doi.org/10.1016/j.talanta.2013.12.012 https://doi.org/10.1016/bs.mie.2018.05.008 https://doi.org/10.1016/bs.mie.2018.05.008 https://doi.org/10.1016/bs.mie.2018.05.008 https://doi.org/10.1016/bs.mie.2018.05.008 https://doi.org/10.1002/elan.200804277 https://doi.org/10.1002/elan.200804277 https://doi.org/10.1002/elan.200804277 https://doi.org/10.1002/elan.200804277 https://doi.org/10.1002/elan.200804277 https://doi.org/10.1016/j.jelechem.2020.114324 https://doi.org/10.1016/j.jelechem.2020.114324 https://doi.org/10.1016/j.jelechem.2020.114324 https://doi.org/10.1016/j.jelechem.2020.114324 https://doi.org/10.1016/j.aca.2016.03.026 https://doi.org/10.1016/j.aca.2016.03.026 https://doi.org/10.1016/j.aca.2016.03.026 https://doi.org/10.1016/j.aca.2016.03.026 https://doi.org/10.1016/j.aca.2016.03.026 https://doi.org/10.1002/celc.202000050 https://doi.org/10.1002/celc.202000050 https://doi.org/10.1002/celc.202000050 https://doi.org/10.1002/celc.202000050 https://doi.org/10.1016/j.diamond.2020.107710 https://doi.org/10.1016/j.diamond.2020.107710 https://doi.org/10.1016/j.diamond.2020.107710 https://doi.org/10.1016/j.diamond.2020.107710 https://cmuj.cmu.ac.th/cmu_journal/journal_de.php?id=162 https://cmuj.cmu.ac.th/cmu_journal/journal_de.php?id=162 https://cmuj.cmu.ac.th/cmu_journal/journal_de.php?id=162 https://cmuj.cmu.ac.th/cmu_journal/journal_de.php?id=162 https://doi.org/10.1007/s00604-017-2521-8 https://doi.org/10.1007/s00604-017-2521-8 https://doi.org/10.1007/s00604-017-2521-8 https://doi.org/10.1007/s00604-017-2521-8 https://doi.org/10.1007/s00604-017-2521-8 https://doi.org/10.2991/amsee-16.2016.3 https://doi.org/10.2991/amsee-16.2016.3 https://doi.org/10.2991/amsee-16.2016.3 https://doi.org/10.2991/amsee-16.2016.3 https://doi.org/10.2991/amsee-16.2016.3 https://doi.org/10.3390/polym9040150 https://doi.org/10.3390/polym9040150 https://doi.org/10.3390/polym9040150 https://doi.org/10.3390/molecules25071712 https://doi.org/10.3390/molecules25071712 https://doi.org/10.3390/molecules25071712 https://doi.org/10.3390/molecules25071712 https://doi.org/10.1039/c3ta13431h https://doi.org/10.1039/c3ta13431h https://doi.org/10.1039/c3ta13431h https://doi.org/10.1007/s10965-014-0361-3 https://doi.org/10.1007/s10965-014-0361-3 https://doi.org/10.1007/s10965-014-0361-3 http://www.electrochemsci.org/papers/vol11/110201707.pdf http://www.electrochemsci.org/papers/vol11/110201707.pdf http://www.electrochemsci.org/papers/vol11/110201707.pdf http://www.electrochemsci.org/papers/vol11/110201707.pdf http://www.electrochemsci.org/papers/vol11/110201707.pdf https://doi.org/10.1021/acs.jpcc.5b04155 https://doi.org/10.1021/acs.jpcc.5b04155 https://doi.org/10.1021/acs.jpcc.5b04155 https://doi.org/10.1016/j.electacta.2014.08.021 https://doi.org/10.1016/j.electacta.2014.08.021 https://doi.org/10.1016/j.electacta.2014.08.021 https://doi.org/10.1016/j.electacta.2014.08.021 introduction ii. materials and methods a. tools and materials b. fabrication of electrodes c. electro polymerization of pyrrole d. nafion and ionic liquid coating e. bismuth film electro polymerization iii. results and discussions a. sem-based electrode characterization b. electrochemical characterization of electrodes 1) stability of reference electrodes observation of bismuth electro polymerization currents 3) lead electrochemical detection iv. conclusion acknowledgments declarations author contribution funding statement competing interest additional information references microsoft word vol03_no1 mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved the effect of ethanol-diesel blends on the performance of a direct injection diesel engine pengaruh penambahan etanol pada solar terhadap motor diesel injeksi langsung arifin nur a,*, yanuandri putrasari a, iman kartolaksono reksowardojo b a bidang sarana peralatan transportasi, pusat penelitian tenaga listrik dan mekatronik-lipi kompleks lipi jl sangkuriang, gd 10, bandung, jawa barat 40135, indonesia b laboratorium motor bakar dan sistem propulsi, institut teknologi bandung jl. ganesa 10, bandung, jawa barat 40132, indonesia received 29 may 2012; received in revised form 12 july 2012; accepted 13 july 2012 published online 31 july 2012 abstract the experiment was conducted on a conventional direct injection diesel engine. performance test was carried out to evaluate the performance and emission characteristics of a conventional diesel engine that operates on ethanol-diesel blends. the test procedure was performed by coupling the diesel engine on the eddy current dynamometer. fuel consumption was measured using the avl fuel balance, and a hotwire anemometer was used to measure the air consumption. some of the emission test devices were mounted on the exhaust pipe. the test of fuel variations started from 100% diesel fuel (d100) to 2.5% (de2.5), 5% (de5), 7.5% (de7.5), and 10% (de10) ethanol additions. performance test was conducted at 1500 rpm with load variations from 0 to 60 nm by increasing the load on each level by 10 nm. the addition of 5% ethanol to diesel (de5) increased the average pressure of combustion chamber indication to 48% as well as reduced the specific fuel consumption to 9.5%. there were better exhaust emission characteristics at this mixture ratio than diesel engine which used pure diesel fuel (d100), the reduction of co to 37%, hc to 44% and opacity to 15.9%. key words: performance test, fuel supplement, bioethanol, emission, diesel engine. abstrak eksperimen dilakukan pada motor diesel dengan sistem injeksi langsung (direct injection). uji prestasi ini dilakukan guna melihat karakteristik prestasi dan emisi motor diesel konvensional terhadap penambahan etanol sebagai bahan bakar suplemen pada solar. uji prestasi dilakukan dengan menempatkan motor uji pada perangkat eddy current dynamometer. konsumsi bahan bakar diukur dengan menggunakan perangkat avl fuel balance sementara untuk pengukuran konsumsi udara digunakan hotwire anemometer. beberapa perangkat uji emisi dipasangkan pada saluran gas buang motor diesel untuk mengukur emisi. beberapa variasi campuran solar dengan etanol diujikan pada penelitian ini. campuran bahan bakar yang diujikan mulai dari solar 100% (d100), penambahan etanol 2,5% (de2,5), 5% (de5), 7,5% (de7,5), dan pada campuran 10% etanol (de10). uji prestasi dilakukan pada 1500 rpm dengan variasi pembebanan mulai dari 0 nm (no load) sampai 60 nm (full load) dengan penambahan beban setiap 10 nm. penambahan 5% etanol dalam solar dapat meningkatkan tekanan rata-rata indikasi ruang bakar sebesar 48% disertai penurunan konsumsi bahan bakar spesifik mencapai 9,5%. pada rasio campuran ini terjadi perbaikan karakteristik emisi gas buang di mana emisi karbon monoksida (co) tereduksi hingga 37 %, emisi hidrokarbon (hc) tereduksi hingga 44%, dan kadar kepekatan emisi gas buang tereduksi hingga 15,9% jika dibandingkan dengan motor diesel yang menggunakan bahan bakar solar murni (d100). kata kunci: uji prestasi, pencampur solar, etanol, emisi, motor diesel. i. pendahuluan kebutuhan energi dunia dari tahun ke tahun kian meningkat, khususnya bahan bakar berbasis minyak bumi. tingkat ketergantungan yang tinggi akan sumber energi berbasis minyak bumi telah membuat harga pasarannya semakin mahal, semakin fluktuatif, dan sangat dipengaruhi oleh pasar serta suhu perpolitikan dunia [1]. di sisi lain, kurang terkontrolnya konsumsi bahan bakar * corresponding author. tel: +62-22-2503055 e-mail: arifin.nur@lipi.go.id a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 50 minyak berbasis minyak bumi juga telah meningkatkan suhu permukaan bumi (global warming) dan mengakibatkan perubahan iklim global. meningkatnya suhu permukaan bumi terjadi akibat gas co2 yang terlepas ke udara akibat aktifitas manusia dan proses pembakaran bahan bakar fosil. salah satu cara untuk menekan atau memperlambat efek pemanasan global adalah dengan menggunakan bahan bakar ramah lingkungan dan penggunaan teknologi hemat energi. perubahan iklim, sumber cadangan, dan karakteristik bahan bakar menjadi bahan pertimbangan dalam pemilihan sumber energi alternatif untuk motor diesel. pentingnya kesesuaian karakteristik bahan bakar alternatif sebagai suplemen pada solar dikarenakan pada akhirnya proses pembakaranlah yang akan memegang peranan terhadap unjuk kerja maupun pembentukan emisi pada motor diesel. proses pembakaran pada motor diesel merupakan sebuah proses yang kompleks, dimulai sejak bahan bakar itu diinjeksikan ke dalam ruang bakar sampai pada proses pembuangan gas buang sisa pembakaran [2]. parameter yang sangat mempengaruhi proses pembakaran pada motor diesel di antaranya adalah kehomogenan campuran bahan bakar dengan udara, waktu injeksi bahan bakar, dan karakteristik bahan bakar seperti volalitas, bilangan setana, auto ignition temperature, flash point, tingkat penguapan dan lain sebagainya [3-5]. bioetanol fuel grade memiliki sejumlah keunggulan dibanding bahan bakar alternatif lain di antaranya adalah: 1. dapat langsung dicampur dengan solar dalam tangki bahan bakar untuk kemudian diinjeksikan ke ruang bakar [6], 2. bahan baku pembuatan bioetanol berasal dari sumber daya terbarukan berupa tanaman atau biomassa yang mengandung gula, pati atau selulosa [6], 3. dapat menurunkan kadar kepekatan emisi gas buang motor diesel (particulate matter) [7-18] dan menekan emisi gas rumah kaca (co2) [6], 4. memperkuat ekonomi pertanian dan menciptakan lapangan kerja baru [13,14]. 5. secara umum dapat mengurangi tingkat ketergantungan terhadap bahan bakar fosil dengan pendekatan energy balance [16] dan melestarikan sumber energi komersial utama [13]. etanol termasuk dalam oxygenate fuel dengan kandungan oksigen mencapai 35%. kandungan oksigen yang tinggi pada bahan bakar akan memperbaiki proses pembakaran sehingga emisi gas buang yang dihasilkan akan lebih rendah jika dibandingkan dengan penggunaan solar sebagai bahan bakar [13-18]. selain banyaknya keunggulan bioetanol sebagai bahan bakar pengganti maupun pencampur pada solar, campuran solar-etanol juga memiliki kekurangan dibandingkan solar murni sebagai bahan bakar motor diesel. kekurangannya adalah: 1. diperlukannya aditif untuk memastikan tercampurnya kedua bahan bakar secara homogen [6,14,19,20], 2. campuran tersebut memiliki kemampuan pelumasan yang rendah sehingga meningkatkan resiko keausan pada komponen pompa bahan bakar dan umumnya akan menurunkan nilai setana solar [14,17,18]. meskipun telah banyak literatur maupun penelitian mengenai pemanfaatan etanol yang dicampur dengan solar pada motor diesel, namun kelengkapan informasi mengenai pencampurannya serta variasi persentasenya mendorong untuk dilakukan penelitian lebih lanjut. kajian ini bertujuan memaparkan hasil uji prestasi motor diesel terhadap penambahan etanol dalam solar pada rasio campuran 0%, 2,5%, 5%, 7,5% dan 10%. motor diesel yang digunakan adalah motor diesel jenis injeksi tidak langsung yang kemudian dimodifikasi sehingga dapat beroperasi secara injeksi langsung. di samping prestasi, pengaruh emisi yang dihasilkan dari motor diesel juga dibahas untuk kelengkapan informasi bagi peneliti maupun akademisi yang tertarik mendalami penelitian motor diesel solar-etanol. ii. metodologi penelitian pengujian dilakukan pada motor diesel 2 (dua) silinder 1630 cm3, sistem pengisian alamiah dan berpendingin air, dengan spesifikasi seperti pada tabel 1. motor diesel konvensional jenis injeksi tidak langsung telah dimodifikasi sehingga dapat beroperasi sebagai motor diesel injeksi langsung. piston telah diganti dengan jenis bowl, sedangkan cylinder head telah dimodifikasi sehingga tidak memiliki kamar pusar (swirl chamber). gambar hasil modifikasi diperlihatkan seperti pada gambar 1. sebuah sensor tekanan ruang bakar buatan kistler 6061b jenis pendingin air ditempatkan pada ruang bakar silinder pertama (gambar 2). sensor tekanan udara masuk dan tekanan gas buang ditempatkan pada saluran masuk dan keluar silinder pertama. motor uji kemudian dipasangkan pada eddy current dynamometer untuk dilakukan uji unjuk kerja. sebuah hotwire anemometer buatan tgs digunakan untuk penguku konsums balance gas bua saluran g dan smo buatan motor di dasar pe instalasi uji u dengan p nm (tan dengan buah da peningka tekanan digunaka sebesar sebagai grade 99,87%. (span meningk solar den g g uran konsum si bahan b buatan av ang dilakuka gas buang d oke meter. s com dipas iesel sebagai erhitungan te pengujian d unjuk kerja pembebanan npa beban) sa peningkatan ata tekanan atan pembeb untuk mot an adalah 48,6, sedang suplemen p dengan tin pada peneli 80) digunak katkan kesta ngan etanol. gambar 2. insta gambar 1. has a. nur et msi udara m bakar diuku vl. untuk p an dengan dengan probe sebuah sens sangkan pad i acuan posi ekanan ruan diperlihatkan dilakukan n yang bervar ampai 60 nm n beban seti ruang baka banan yang tor 4 langk solar deng gkan etanol pada solar ad gkat kemu itian ini sorb kan sebagai abilan ikata alasi pressure t il modifikasi ru t al. / mechatroni masuk, sedan ur dengan engukuran e menghubun e 4 gas ana sor sudut en da poros en isi piston seb ng bakar. sk pada gamba pada 1500 riasi mulai d m (beban pe iap 10 nm. ar diambil s berisi 720 kah. solar gan nilai se yang digun dalah etanol urnian menc bitan metil e surfaktan u an kimia an tranduscer. uang bakar. ics, electrical pow ngkan fuel emisi ngkan alyzer ngkol ngkol bagai kema ar 3 rpm dari 0 enuh) 100 setiap data yang etana nakan l fuel capai ester untuk ntara i a te r m d d 1 t m r g b m d e e c tu b d p b 7 m k wer, and vehicul iii. hasi a. perband effective p indicated ekanan efek rata-rata yan motor pemba dalam eksp disajikan me 100 siklus tekanan ini mesin secara rugi-rugi dari grafik perban breake mean motor diese dibandingkan etanol pada etanol 7,5% d nilai im campuran te urun kembal berbahan ba didapatkan p persentase et bahan bakar 7,5 % (de7, memiliki kec keterangan: 1 2 motor die dynamom 3 com enc 4 radiator 5 hot wire anemom 6 plenum u 7 pengukur bahan bak 8 pengkond transduce gam lar technology 03 l dan pem dingan im pressure) mean eff ktif rata-rata ng terukur p akaran dalam perimen ini rupakan rata pembakaran i dapat m ideal tanpa i faktor lain. ndingan nila n effective p el berbahan n dengan b persentase e dan etanol 10 ep cenderu ertentu (etan li mendekati akar solar. pada campur tanol 5% (d r dengan ca ,5), sedangka enderungan esel meter coder meter udara masuk r konsumsi kar disi sensor er mbar 3. skema i 3 (2012) 49-56 mbahasa mep (indica ffective pre indikasi ada pada piston m untuk setia tekanan i a-rata pengu n pada mo menggambark terpengaruh gambar 4 m ai imep ter pressure (bm n bakar bahan bakar etanol 2,5%, 0%. ung naik sa nol 5%) dan nilai imep nilai ime ran bahan ba de5) kemu ampuran eta an ketiga gr nilai yang sa 9 com sig condition 10 kontrol p 11 data aku 12 fuel bala 13 emission analyzer 14 pressure sensor 15 sensor e buang instalasi penguj 51 an ated mean essure atau alah tekanan dari sebuah ap siklusnya. imep yang ukuran untuk otor diesel. kan prestasi oleh adanya menunjukkan rhadap nilai mep) antara solar yang r campuran , etanol 5%, ampai batas n kemudian motor diesel ep tertinggi akar dengan udian diikuti anol sebesar rafik lainnya ama. gnal ning pembebanan uisisi ance n gas e transducer emisi gas ian. n u n h . g k . i a n i a g n , s n l i n i r a a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 52 berdasarkan penelitian sebelumnya yang dilakukan oleh reksowardojo dkk [20], di mana persentase campuran yang sama juga telah diujikan pada motor diesel jenis injeksi tidak langsung menunjukkan bahwa pada campuran etanol 5% didapatkan kestabilan tekanan ruang bakar yang baik jika dibandingkan dengan rasio campuran lainnya. hal ini mengindikasikan bahwa pada campuran ini pembakaran yang terjadi di dalam ruang bakar cenderung lebih sempurna dan pada waktu yang relatif tepat. penambahan etanol pada solar akan memperlambat waktu penyalaan namun juga akan memperpendek durasi pembakaran. b. perbandingan konsumsi bahan bakar – brake specific fuel consumption (bsfc) brake specific fuel consumption atau konsumsi bahan bakar spesifik merupakan salah satu indikator untuk mengetahui prestasi motor bakar. bsfc adalah laju pemakaian bahan bakar dibagi daya setiap jamnya atau jumlah bahan bakar yang diperlukan untuk menghasilkan satu satuan daya dalam setiap satu-satuan waktu. perbandingan bsfc hasil uji terhadap unjuk kerja motor diesel berbahan bakar diesel murni, campuran etanol de2,5, de5, de7,5 dan de10 ditampilkan dengan grafik pada gambar 5. hasil pengujian menunjukkan bahwa bsfc tertinggi didapatkan pada motor diesel berbahan bakar solar murni dan bsfc terendah didapatkan dari motor diesel berbahan bakar campuran solar dengan etanol pada rasio perbandingan etanol 5% (de5) dan etanol 7,5% (de7,5). pada persentase campuran etanol yang lebih tinggi (de10) konsumsi bahan bakar persatuan waktu akan meningkat kembali. hal ini menunjukkan bahwa campuran optimal berada pada kisaran 5% etanol sampai etanol 7,5%. rendahnya konsumsi bahan bakar spesifik pada campuran etanol 5% dan 7,5% disebabkan oleh beberapa hal di antaranya adalah: 1. tingginya nilai panas spesifik etanol, dibandingkan dengan solar [21], 2. etanol pada perbandingan tertentu dapat memperpendek durasi pembakaran yang secara signifikan akan meningkatkan tekanan dalam ruang bakar, 3. waktu penyalaan yang tepat, sehingga pada fase pembakaran difusi (diffusion burning period) hampir semua campuran bahan bakar terbakar dengan sempurna dan sebagai akibatnya pada fase akhir pembakaran (after burning period) hanya tersisa sedikit sekali bahan bakar yang tidak terbakar [22]. c. perbandingan nilai lambda (λ) pada eksperimen ini, penambahan rasio persentase etanol dalam solar akan meningkatkan tabel 2 spesifikasi bahan bakar. karakteristik solar hsd etanol formula kimia [24] c3 c25 c2h5oh berat molekul [24] ≈200 46,7 komposisi [24] karbon (c) 84-87 52,5 hidrogen (h) 16-33 13,1 oksigen (o2) 0 34,7 nilai setana 45 [25] 0-9 [8,11] nilai oktana n/a [24] 100 [24] lower heating value [mj/kg] 42,5 [19] 28,4 [19] densitas [kg/m3] @ 20 oc 815 [25] 786 [19] viskositas [mm2/sec] @40oc 2,0 [25] 1,412 [26] titik nyala [oc] 60 [25] 12,778 [27] afr [24] 14,7 9 gambar 5. karakteristik bsfc terhadap bmep. 300 400 500 600 700 800 900 1000 0 1 2 3 4 5 6 7 8 9 10 b sf c  [ gr /k w .h ] bmep [bar] di d 100 di de 2,5 di de 5  di de 7,5  di de 10 gambar 4. karakteristik imep terhadap bmep. 0,0 1,0 2,0 3,0 4,0 5,0 6,0 0 1 2 3 4 5 6 7 8 9 10 im ep  [ b ar ] bmep [bar] di d 100 di de 2,5 di de 5  di de 7,5  di de 10 a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 53 nilai lambda sampai batas rasio tertentu sehingga campuran menjadi semakin miskin. peningkatan nilai lambda rata-rata terhadap tiap tingkat pembebanan pada rasio campuran etanol 2,5% (de2,5), 5% (de5), 7,5% (de7,5) dan 10% (de10) berturut-turut mencapai 0,40%, 15,34%, 19,72%, dan 5,44% jika dibandingkan dengan nilai lambda yang dihasilkan dari pembakaran solar murni. peningkatan maksimum nilai lambda rata-rata terjadi pada nilai bmep 4,625 yaitu sebesar 17,5% untuk semua rasio campuran dibandingkan dengan solar murni (d100). pada rasio campuran etanol 2,5% (de2,5) nilai lambda berkisar antara 1,108 sampai 4,064. pada rasio campuran etanol 5% (de5) nilai lambda berkisar antara 0,844 sampai 4,254, de7,5 berkisar antara 1,166 sampai 4,527, dan pada rasio campuran etanol 10% (de10) berkisar antara 0,886 sampai 4,414. meningkatnya nilai lambda menunjukkan bahwa campuran bahan bakar-udara menjadi semakin miskin. analisis nilai lambda dengan nilai imep menunjukkan bahwa rasio campuran etanol 5% merupakan titik optimal di mana nilai imep dan nilai lambda mencapai titik maksimum. proses pembakaran sempurna ditandai dengan tingginya nilai imep, sedangkan nilai optimal penggunaan bahan bakar ditandai dengan nilai lambda yang tinggi, sehingga untuk menghasilkan satu satuan daya tertentu dibutuhkan jumlah bahan bakar yang sedikit yang artinya konversi energi menjadi kerja maksimum. meningkatnya kesempurnaan proses pemcampuran bahan bakar-udara dan proses pembakaran akan meningkatkan unjuk kerja motor uji. kecenderungan meningkatnya nilai lambda yang dihasilkan oleh motor diesel direct injection menunjukkan bahwa proses pembakaran akan mencapai titik optimal pada rasio campuran etanol 7,5% (de7,5). d. perbandingan emisi karbon monoksida (co) gambar 7 menunjukkan perbandingan grafik emisi co terhadap beban antara motor diesel berbahan bakar solar murni (d100), rasio campuran de2,5, de5, de7,5, dan de10. semakin besar persentase emisi co yang dihasilkan menunjukkan bahwa pembakaran yang terjadi tidak sempurna sehingga bahan bakar yang tidak terbakar akan membentuk emisi co. meskipun motor diesel beroperasi dengan sistem tanpa pencekikan (throttleless), dan diyakini jumlah udara yang masuk ke dalam ruang bakar tercukupi, namun ketidaksempurnaan pembakaran ini dapat terjadi karena pencampuran bahan bakar dengan udara dilakukan pada waktu yang sangat singkat, sehingga menyebabkan sebagian dari bahan bakar tidak dapat berikatan dengan udara secara sempurna untuk kemudian terbakar di dalam ruang bakar. pada bahan bakar jenis oxygenated fuel di mana tiap ikatan kimianya telah mengandung oksigen seperti biodiesel ataupun etanol, proses pencampuran antara bahan bakar dengan udara cenderung lebih mudah. sifat inilah yang menjadi salah satu keuntungan pemanfaatan bahan bakar nabati pada motor bakar. pada penelitian ini emisi karbon monoksida terendah didapatkan pada campuran de5 dan de7,5. sementara pada campuran yang lebih tinggi (de10), meskipun secara logika dapat dipastikan bahwa bahan bakar akan dapat berikatan secara sempurna dengan udara, namun karena penambahan bahan bakar jenis oxygenated fuel dengan nilai setana rendah secara gambar 6. karakteristik lambda [λ] terhadap bmep. 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 10 la m b d a  [λ ] bmep [bar] di d 100 di de 2,5 di de 5 di de 7,5  di de 10 gambar 7. karakteristik emisi karbon monoksida (co) terhadap bmep. 0 0,2 0,4 0,6 0,8 1 1,2 0 1 2 3 4 5 6 7 8 9 10 k ar b o n  m o n o ks id a  [% ] bmep [bar] di d 100 di de 2,5 di de 5 di de 7,5  di de 10 a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 54 signifikan akan memperlambat waktu penyalaan, maka sebagian besar campuran bahan bakar dengan udara baru terbakar pada fase akhir pembakaran (after burning period) di mana piston sudah melakukan langkah ekspansi. terbakarnya campuran bahan bakar pada fase akhir pembakaran akan membuat pembakaran yang terjadi menjadi tidak sempurna. e. perbandingan emisi hydro carbon (hc) perbandingan jumlah hc antara mesin diesel berbahan bakar solar (d100), rasio campuran solar-etanol de2,5, de5, de7,5 dan de10 ditampilkan pada gambar 8. grafik menunjukkan kecenderungan yang sama di mana nilai kandungan emisi hc pada campuran solar-etanol dengan persentase 5% (de5) dan 7,5% (de7,5) cenderung lebih rendah jika dibandingkan dengan rasio campuran lainnya. besarnya emisi hc disebabkan oleh proses pencampuran antara bahan bakar dengan udara yang tidak sempurna sehingga menyebabkan campuran bahan bakar dengan udara tersratafikasi mulai dari campuran yang miskin sampai campuran kaya dengan butiran-butiran (droplet) bahan bakar yang besar. umumnya emisi hc terbentuk pada wilayah campuran sempurna dan wilayah campuran yang terbentuk sebelum penyalaan sehingga ada sedikit campuran bahan bakar dengan udara yang keluar dari ruang bakar atau pada saat di mana bahan bakar diinjeksikan dengan kecepatan yang rendah dan proses pencampuran terjadi pada saat mendekati akhir pembakaran. pada kasus ini, penambahan etanol pada solar dapat memperbaiki proses pencampuran antara bahan bakar dengan udara. emisi hc yang dihasilkan dari campuran solar-etanol cenderung sama atau lebih rendah dari motor diesel yang menggunakan solar murni. meningkatnya emisi hc pada campuran solar-etanol dengan persentase 10% (de10) disebabkan campuran bahan bakar dengan udara di dalam ruang bakar menjadi semakin miskin dibandingkan dengan persentase campuran lain. f. perbandingan kepekatan emisi gas buang (smoke) perbandingan tingkat kepekatan emisi gas buang (smoke) antara motor diesel berbahan bakar solar murni, campuran solar-etanol de2,5, de5, de7,5, dan de10 ditampilkan pada gambar 9. nilai persentase smoke tertinggi dihasilkan oleh motor diesel berbahan bakar solar murni dan persentase smoke terendah didapatkan dari motor diesel dengan bahan bakar campuran solar-etanol dengan persentase 10% (de10). besarnya penurunan tingkat kepekatan gas buang (smoke) mencapai 22% jika dibandingkan dengan smoke yang dihasilkan motor diesel berbahan bakar solar. rendahnya nilai smoke pada motor diesel yang beroperasi dengan campuran solar-etanol disebabkan karena etanol merupakan bahan bakar dengan ikatan karbon pendek sehingga lebih mudah terurai dan berikatan dengan udara di dalam ruang bakar. selain itu kandungan oksigen pada etanol yang mencapai 35% sangat membantu dalam pembentukan campuran bahan bakar-udara menjadi lebih homogen. iv. penutup a. kesimpulan unjuk kerja motor diesel terbaik ditunjukkan pada penggunaan campuran solar dengan etanol 5%. campuran solar dengan etanol 5% (de5) gambar 8. karakteristik emisi hc terhadap beban (bmep). 0 50 100 150 200 250 0 1 2 3 4 5 6 7 8 9 10 h yd ro  c ar b o n  [ p p m ]  bmep [bar] di d 100 di de 2,5 di de 5 di de 7,5  di de 10 gambar 9. karakteristik tingkat kepekatan emisi gas buang terhadap beban (bmep). 0 10 20 30 40 50 60 70 80 90 100 0 1 2 3 4 5 6 7 8 9 10 sm o ke  [ %  in d ex  b o sc h ] bmep [bar] di d 100 di de 2,5 di de 5 di de 7,5  di de 10 a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 55 akan meningkatkan unjuk kerja motor diesel yang diukur dari peningkatan nilai imep mencapai 48% mereduksi tingkat kebutuhan bahan bakar rata-rata (bsfc) mencapai 9,5%. dari sisi emisi gas buang, penggunaan etanol sebagai bahan bakar suplemen pada motor diesel konvensional secara signifikan akan menurunkan emisi co rata-rata mencapai 37%, menurunkan emisi hc rata rata mencapai 44%, dan menurunkan tingkat kepekatan gas buang (smoke) rata rata mencapai 15,9%. b. saran berikut beberapa saran yang perlu diperhatikan dalam pemanfaatan etanol sebagai bahan bakar alternatif. 1. etanol merupakan salah satu bahan bakar alternatif yang potensial untuk dikembangkan sebagai bahan bakar tambahan (suplemen) pada motor diesel injeksi langsung. 2. perlu dilakukan penelitian komprehensif pemanfaatan etanol sebagai bahan bakar penambah pada solar karena meskipun etanol sudah memiliki spesifikasi fuel grade namun karena sifat etanol yang cenderung mengikat air pada udara maka akan mempengaruhi kualitas bahan bakar. 3. perlu dilakukan uji ketahanan (durability) untuk melihat pengaruh penggunaan campuran solar-etanol pada motor diesel dalam jangka panjang karena sifat pelumasan (lubrication) etanol yang rendah. ucapan terima kasih ucapan terima kasih dan penghargaan yang setinggi-tingginya kami sampaikan kepada pusat penelitian tenaga listrik dan mekatronik-lipi atas pembiayaan penelitian ini melalui proyek kompetitif lipi tahun anggaran 2011-2012, kepada bapak ahmad dimyani dan saudara mulia pratama yang telah mendukung terlaksananya penelitian ini. referensi [1] i.k. reksowardojo, t.h. soerawidjaja, “key energy technologies for a sustainable future,” the 1st international workshop on renewable and energy conservation (reec 2009), ho chi minh city, vietnam, 2009. [2] hsu. b.d, “practical diesel-engine combustion analysis,” society of automotive engineers, inc, isbn: 0-76800914-6., 2002, pp. 1 10. [3] y. icingur, d. altiparmak, “experimental analysis of the effect of fuel injection pressure and cetane number on direct injection diesel engine emissions,” turkish j. eng. env. sci 27, ©tubitak, 2001, pp. 291 – 297. [4] safgönül. b, “reciprocating enginesvolume 1,” itü makine fakültesi, istanbul, 1989. [5] borat. o, balci. m, sürmen. a, “internal combustion engines,” g.ü. teknik eğitim fakültesi matbaasi, cilt 1, ankara, 1994. [6] lei, j. shen, l. bi, y. chen, h., “a novel emulsifier for ethanol–diesel blends and its effect on performance and emissions of diesel engine,” fuel, 93, 305-311, 2012. [7] song. c, et al. “carbonyl compound emissions from a heavy-duty diesel engine fueled with diesel fuel and ethanol–diesel blend,” chemosphere 79: 1033-1039, 2010. [8] z. guo, tianrui li, j. dong, r. chen, peijun xue, x. wei, "combustion and emission characteristics of blends of diesel fuels and methanol-to-diesel," fuel, 90, 13051308, 2011. [9] j. huang, y. wang, li. s, a.p. roskilly, yu. h, li. h, "experiment investigation on the performance and emission of a diesel engine fuelled with ethanol-diesel blends," applied thermal engineering, 29, 2484-2490, 2009. [10] kass. m.d, thomas. j.f, storey. j.m, domingo. n, wade. j, kenreck. g, “emission from a 5.9 liter diesel engine fueled with ethanol diesel blends,” sae technical paper 2001-01-2018 (sp-1632), 2001. [11] park s.h, yun i.m, lee c.s, "influence of ethanol blends on the combustion performance and exhaust emission characteristic of a four-cylinder diesel engine at various engine loads and injection timings," fuel, 90, 748-755, 2011. [12] shen. l.z, yan.w.s, bi. y.h, lei. j.l, "performance comparison of ethanol/diesel blends mixed in different methods of diesel engine," j combust sci technol, 13: 389-392, 2007. [13] e.a. ajav, bachchan sigh, t.k. bhattacharya, "experimental study of some performance parameter of a constant speed stationary diesel engine using ethanoldiesel blends as fuel," biomass & bioenergy, 14, 353-365, 1999. [14] d.c. rakopoulos, c.d. rakopoulos, r.g. papagiannakis, d.c. kyritsis, "combustion heat release analysis of ethanol or nbutanol diesel fuel blends in heavy duty a. nur et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 49-56 56 di diesel engine,” fuel, 90, 1855-1867, 2011. [15] lapuerta m, armas. o, herreros josě m, “emission from a diesel-bio-ethanol blend in a automotive diesel engine,” fuel 1, 2531, 2008. [16] ubner. m, muller-langer. f, “biofuels today and tomorrow: effects of fuel composition on exhaust gas emissions,” accreditation and quality assurance 14, 685-691, 2009. [17] ahmed. i, “oxygenated diesel: emission and performance characteristic of ethanol diesel blends in ci engines,” sae tec paper ser. no. 2001-01-2475, 2001. [18] zhu l, cheung c.s, zhang w.g, huang z, “combustion, performance and emission characteristics of a di diesel engine fueled with ethanol-biodiesel blends,” fuel 90, 1743-1750., elsevier, 2011. [19] lapuerta. m, armas. o, r.g. contreras, "stability of diesel-ethanol blends for use in diesel engines," fuel, 86, 1351-1357, 2007. [20] i.k. reksowardojo, arifin nur, w.b. santoso, y. putrasari, “statistical analysis to determine the effect of diesel-ethanol blending on stationary idi diesel engine performance,” the 4th aun/seed-net rc meae 2012, proceeding isbn 978-604-730701-2, 2012. [21] rakopoulos. d.c, rakopoulos. c.d, karakas. e.c, giokoumis. e.g, “effects of ethanol–diesel fuel blends on the performance and exhaust emissions of heavy duty di diesel engine,” energy conversion and management 49, 3155-3162, 2008. [22] challen, b.baranescu , r. “diesel engine reference book,” 2nd edition, butterworthheinemann., isbn: 0 7506 2176 1, 1999, pp. 1 – 89. [23] american petroleum institute (api), “alcohol and ethers,” publication no.4261, 2nd edition, july 1988 [24] http://www.pertamina.com/index.php/ detail/read/minyak-solar, diakses 12 juli 2012. [25] “laporan hasil analisis,” no. ref.0077f/uljak/v/2011, pusat penelitian kimialipi, 2011. [26] “5. alcohol and cotton oil as alternative fuels for internal combustion engines,” www.fao.org/docrep/t4470e, diakses 04 mei 2011. microsoft word vol03_no1 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 03, issue 1, july 2012 insured editor head of research centre for electrical power and mechatronics editor-in-chief dr.eng. estiko rijanto (control system and mechatronics engineering) managing editor tinton d atmaja, m.t. (information system and electrical engineering) peer reviwers dr.-ing. moch ichwan (vehicular technology; lipi) ir. edi leksono, m.eng., phd. (electrical engineering; itb) dr.eng. estiko rijanto (mechatronics and control systems; lipi) ir. arko djajadi, ph.d. (mechatronics; swiss german university) dr. ahmad agus setiawan (renewable energy systems; ugm) dr. irhan febijanto (renewable energy development and cdm project; bppt) dr. yuliadi erdani (informatics engineering; politeknik manufaktur) riza muhida, ph.d. (mechatronics engineering; stkip surya) dr.ir. rizqon fajar, m.sc. (fuels and lubricant; bppt) advisory editor rachmini saparita, phd. (interdisciplinary engineering) copy editors naili huda, m.eng.sc (industrial engineering) achmad praptijanto, m.eng. (mechanical engineering) nur rohmah, m.t. (chemical engineering) proofreader ghalya pikra, m.t. (energy conversion) subscription manager noviadi a rachman, m.t. (electrical engineering) secretariat andri j purwanto, s.t. (mechanical engineering) section editors merry i devi, s.t. (industrial engineering) vita susanti, s.kom. (computer science) layout editors aam muharam, m.t. (electrical engineering) arief a firdaus, s.i.kom. (communication science) web admin dadan r saleh, m.t. (informatics engineering) graphic designer m. redho kurnia, s.sn. (graphic design) mechatronics, electrical power, and vehicular technology (mev) is a journal aims to be a leading peerreviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics. mev is published and imprinted by research center for electrical power and mechatronics indonesian institute of sciences and managed to be issued twice in every volume. for every edition, the online edition is published earlier than the print edition. journal address secretariat research centre for electrical power and mechatronics – indonesian institute of sciences komp lipi jl. sangkuriang, building 20, 2nd floor, r 209, bandung, west java, 40135 indonesia telp: +62-022-2503055/2504770 fax: +62-22-2504773 e-mail: sekretariat@mevjournal.com homepage: www.mevjournal.com; www.telimek.lipi.go.id/mev.htm journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 03, issue 1, july 2012 foreword from editor-in-chief this issue of journal of mechatronics, electrical power, and vehicular technology (mev) is the first issue after the journal has been acreditated by the indonesian institute of sciences (lipi) in april 2012. it is also the first time for the journal that all the processes are carried out through open journal system (ojs). the ojs implementation gave challenge to the most of the authors, members of the editorial board, and the peer reviewers by transforming the business process to electronics journal (e-journal) method. driven by strong integrity and commitment, finally the on-line edition of this issue could be released in july 2012. seven papers have been selected to be published in this issue after having passed some levels of reviews and revisions based on the standard operating procedure of the journal. two topics are related to mechatronics, two topics to electrical power, and three topics are concerned with vehicular technology including both technology aspect and research policy aspect. the total number of paper pages is 56 pages, just the same as that of the previous issue. the policy up to the current issue is that authors are not charged at all. on the other hand, the editorial board is planning to lift the quality up by promoting papers written in english to reach international readers as well as registering the journal to the international academic citation index. moreover, the editorial board is also considering to gradually encrease the number of journal’s pages. all of this plan will give consequence on financial burden. therefore, in the future issues, financial policy will change based on that condition. we wish to offer our thanks to all editorial board members and administration division of the research center for electrical power and mechatronics for their continuing unwavering support. also, we would like to acknowledge our gratitude to this issue’s peer reviewers: ir. arko djajadi, ph.d., dr. yuliadi erdani, dr.-ing. moch ichwan, dr. ahmad agus setiawan, ir. edi leksono, m.eng., phd., riza muhida, ph.d., dr.ir. rizqon fajar, m.sc., and dr. irhan febijanto. we hope this publication would contribute to the enhancement of science and technology. bandung, july 2012 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 ii journal of mechatronics, electrical power, and vehicular technology volume 03, issue 1, july 2012 list of contents direction and policies needed to support hybrid electric car research ridwan arief subekti, agus hartanto, vita susanti 1-8 analysis of inverse angle method for controlling two degree of freedom manipulator hendri maja saputra, zainal abidin, estiko rijanto 9-16 development of discrete power supply with charge pump method for high powered sonar system kristian ismail, syamsu ismail 17-22 magnetic simulation and analysis of radial flux permanent magnet generator using finite element method pudji irasari, hilman syaeful alam, muhammad kasim 23-30 design and implementation of anti-windup pi control on dc-dc bidirectional converter for hybrid vehicle applications muh. zakiyullah romdlony, amin 31-38 modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system edi leksono, justin pradipta, tua agustinus tamba 39-48 the effect of ethanol-diesel blends on the performance of a direct injection diesel engine arifin nur, yanuandri putrasari, iman kartolaksono reksowardojo 49-56 microsoft word vol03_no1_v3 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology peer reviewers prof.dr. jamasri mechanical and industrial engineering gajah mada university jamasri_tmugm@yahoo.com prof.dr. suhono harso supangkat electrical engineering institut teknologi bandung suhono@stei.itb.ac.id george anwar, ph.d. mechanical engineering, dynamics and controls university of california, berkeley ganwar@integratedmotions.com dr.eng. estiko rijanto mechatronics and control systems indonesian institute of sciences estiko@hotmail.com ir. arko djajadi, ph.d. mechatronics engineering swiss german university arko@sgu.ac.id dr. ahmad agus setiawan renewable energy systems gajah mada university a.setiawan@ugm.ac.id dr.eng. budi prawara material engineering indonesian institute of sciences budi.prawara@lipi.go.id ir. edi leksono, m.eng. ph.d. physics engineering institut teknologi bandung edi@tf.itb.ac.id dr. irhan febijanto renewable energy development and cdm project the agency for the assesment and application of technology irhan.febijanto@gmail.com dr. endra joelianto engineering physics, instrumentation & control institut teknologi bandung ejoel@tf.itb.ac.id dr. ir. iman kartolaksono reksowardojo mechanical engineering institut teknologi bandung iman@lmbsp.ms.itb.ac.id riza muhida, ph.d. mechatronics engineering stkip surya riza.muhida@stkipsurya.ac.id dr. yuliadi erdani information, computer science polteknik manufaktur bandung yul_erdani@polman-bandung.ac.id dr.-ing. moch ichwan vehicular technology indonesian institute of sciences moch019@lipi.go.id dr. ir. rizqon fajar, m.sc. fuels and lubricant the agency for the assesment and application of technology rizqon66@gmail.com pudji irasari, m.sc.rer.nat. electrical engineering/electric machines indonesian institute of sciences pudji.irasari@lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 p-issn 2087-3379 iv author information writing should be submitted according to these following restrictions: 1. manuscript should be submitted online via journal website. author must login in order to make submission. online registration will be charged at no cost. 2. manuscript should be contains at least 2.000 words and should not exceed 10 pages a4 including figures and tables, contain no appendix, written using open office text document (.odt) or microsoft word (.doc/.docx) with margin for top, right and bottom is 2cm and 2.5cm for left. 3. title, abstract, and keywords should be written in english and indonesian a. title should be less than 15 words : title case, small caps, centered, bold, font type times new roman (tnr) and single spaced. font size 16 for indonesian title and 14 for english title. b. abstract contains neither pictures nor tables, justified, in 10 tnr and single spaced. the titles are ‘abstract’ (in english) and ‘abstrak’ (in indonesian): justified, bold, in 12 tnr and single spaced. indonesian abstract should not exceed 250 words and english abstract should not exceed 150 words. c. keywords contain three to five words separated with coma, justified, in 10 tnr and single spaced. d. the body of the writing should be in 1 cm spaced two columns, justified, in 11 tnr, and single spaced. 4. manuscript body should be: a. written in two columns, justified, tnr 11, spasi 1, first line indent 5 mm, colom spacing 1 cm. b. consist of four main sections: introduction, main content (method/material/etc), result and discussion, and conclusion; followed by acknowledgment (if any) and references. 5. heading should be made in four levels. level five cannot be accepted. a. heading 1: title case, small caps, left aligned, bold, 14 tnr, single spaced, roman numbered followed by dot (e.g. i. introduction) b. heading 2: title case, left aligned, bold, 11 tnr, single spaced, capital numbered followed by dot (e.g. a. experiment) c. heading 3: title case, left aligned, italic, 11 tnr, single spaced, numbered by number followed by closed bracket (e.g. 1) field experiment) d. heading 4 is not recommended, however, it could still be accepted with the format of: sentence case, left indent 5 mm, hanging indent 5 mm, italic, 11 tnr, single spaced, numbered by small cap followed by closed bracket (e.g. a) field experiment result) 6. figure and table should be in black and white, and if it made in color, it should be readable when it later printed in black and white. figure and table should be clearly readable and in a proportional measure to the overall page. caption should be numbered, in 10 tnr and single spaced. for layouting purpose, please provide the respective captioned figure/table in with extension .tif/.jpg/.jpeg within a particular folder apart from the manuscript. 7. mathematical equation should be clearly written, numbered orderly, and accompanied with any information needed. 8. header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. 9. citation and reference are written according to ieee style a. citations numbering should be numbered in [1], [2], [3], ... format, according to appearance order. b. wikipedia, personal blog, or non scientific website is not allowed to be taken into account. c. primary references should be at least 80% from at least ten references. d. references shoul be taken from the late five years. e. references writing style should be as follows. [1] w.-k. chen, linear networks and systems. 2nd ed., r. m. osgood, jr., ed. belmont, ca: wadsworth, 1993, pp. 23–35. [2] g. o. young, “synthetic structure,”in plastics, 2nd ed., vol. 3, j. peters, ed. new york: mcgraw-hill, 1964, pp. 15–64. [3] j. u. duncombe, “infrared navigation-part i: an assessment,” ieee trans. electron devices, vol. ed-11, pp. 34-39, jan. 1959. [4] e. p. wigner, “theory of optical laser,” phys. rev., vol. 134, pp. a635–a646, dec. 1965. [5] e. h. miller, “a note on reflector arrays,” ieee trans antennas propagat., to be published. [6] d. b. payne and j. r. stern, “wavelength-switched passively,” in proc. iooc-ecoc, 1985, pp. 585–590. [7] d. ebehard and e. voges, “digital single sideband,” presented at the 2nd int. conf. fiber sensors, stuttgart, germany, 1984. [8] g. brandli and m. dick, “alternating current fed power supply,” u.s. patent 4 084 217, nov. 4, 1978. [9] e. e. reber and c. j. carter, “oxygen absorption,” aerospace corp., los angeles, ca, tech. rep. tr-020 (4230-46)-3, nov. 1968 [10] j. jones. (1991, may 10). networks architechture. (2nd ed.) [online]. available: http://www.atm.com/ [11] r. j. vidmar. (1992, aug.). the use of plasm. ieee trans plasma sci. [online]. 21(3), pp. 87–88. available: http://halcyon.com/pub/ [12] process corp., ma. intranets: internet deployed. presented at ine annu. meeting. [online]. available: http://process.com/wp2.htp [13] s. l. talleen. (1996, apr.). the intranet architecture. amdahl corp., ca. [online]. available: http://www.amdahl.com/infra/ 10. detailed writing guidance can be seen in the ‘writing layout manual’ that can be downloaded in journal website. the editorial board is authorized to reject a manuscript based on peer reviewer advice and make a necessary changes or adjustment related with language properties without altering the substance. substance editing would be consulted with the author first editorial board mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology volume 11, 2020 authors index the articles in this volume were authored/co-authored by 51 authors from japan, saudi arabia, indonesia, united kingdom, republic of korea, malaysia, and germany. aam muharam, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 abdul hapid, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 adi izhar bin che ani, “lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller,” 11(1):11-21 adi waskito, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 agus salim, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 agus samsi, “swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm,” 11(1):1-10 amma muliya romadoni, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 andri joko purwanto, “open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance,” 11(1):30-37 anik nur handayani, “lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller,” 11(1):11-21 anisya lisdiana, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 ari priharta, “lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller,” 11(1):11-21 aryo putro sadono, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 bayu prasetyo, “lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller,” 11(1):11-21 catur hilman adritya haryo bhakti baskoro, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 daiki obara, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 daniel christian, “swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm,” 11(1):1-10 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vii djohar syamsi, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 endra joelianto, “swarm control of an unmanned quadrotor model with lqr weighting matrix optimization using genetic algorithm,” 11(1):1-10 erik adiwiguna, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 estiko rijanto, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 evan rizky suryana, “pole placement and lqr implementation on longitudinal altitude holding control of wing in surface effect vehicle,” 11(2):86-94 faiz syaikhoni aziz, “lux and current analysis on lab-scale smart grid system using mamdani fuzzy logic controller,” 11(1):11-21 faiz syaikhoni aziz, “smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback,” 11(2):55-63 ghalya pikra, “open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance,” 11(1):30-37 gun bae park, “a study on the applicability of batik for public transportation design in indonesia,” 11(2):75-85 herkuswyna isnaniyah wahab, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 iman abdurahman, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 kamil faqih, “smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback,” 11(2):55-63 leo parytta, “pole placement and lqr implementation on longitudinal altitude holding control of wing in surface effect vehicle,” 11(2):86-94 maulana arifin, “rotordynamics analysis of solar hybrid microturbine for concentrated solar power,” 11(1):38-44 mikecon cenit, “design and development of the semg-based exoskeleton strength enhancer for the legs,” 11(2):64-74 mitsuru masuda, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 mochammad agoes mulyadi, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 muhammad hafil nugraha, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 muhammad khristamto aditya wardana, “a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system,” 11(1):45-54 muhammad nanda setiawan, “pole placement and lqr implementation on longitudinal altitude holding control of wing in surface effect vehicle,” 11(2):86-94 nur rohmah, “open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance,” 11(1):30-37 ocktaeck lim, “a study effects of injection pressure and wall temperature on the mixing process of nox and nh3 in selective catalytic reduction system,” 11(1):45-54 oka mahendra, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 viii rakhmad indra pramana, “open feed organic heater pressure analysis on single-stage regenerative organic rankine cycle performance,” 11(1):30-37 reiji hattori, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 rendra dwi firmansyah, “a new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” 11(2):102-110 rendra dwi firmansyah, “optimization of ozone chamber using pulse width modulation for sterilization and preservation on fruits and vegetables,” 11(2):111-116 siti sendari, “smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback,” 11(2):55-63 sujito, “smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback,” 11(2):55-63 suziana ahmad, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 tarek mahmoud mostafa, “preliminary study of 50 w class-e gan fet amplifier for 6.78 mhz capacitive wireless power transfer,” 11(1):22-29 teguh tri lusijarto, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 tri admono, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 vaibhav gandhi, “design and development of the semg-based exoskeleton strength enhancer for the legs,” 11(2):64-74 william andaro, “pole placement and lqr implementation on longitudinal altitude holding control of wing in surface effect vehicle,” 11(2):86-94 yoyon ahmudiarto, “numerical investigation of the effect of triangle strut in vertical axis wind turbine (vawt),” 11(2):95-101 yukhi mustaqim kusuma sya’bana, “a study on the applicability of batik for public transportation design in indonesia,” 11(2):75-85 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 ix journal of mechatronics, electrical power, and vehicular technology volume 11, 2020 affiliation index applied science for electronics and materials, interdisciplinary graduate school of engineering sciences, kyushu university, fukuoka, japan 22 automotive products and electronics laboratories, furukawa electric co., ltd., kanagawa, japan 22 computer, electrical, mathematical sciences and engineering (cemse), king abdullah university of science and technology, thuwal, saudi arabia 22 department of aeronautics and astronautics, bandung institute of technology, bandung, indonesia 95 department of design engineering and mathematics, middlesex university london, london, united kingdom 64 department of engineering physics, multimedia nusantara university, tangerang, indonesia 86 department of mechanical engineering, university of ulsan, ulsan, republic of korea 45 department of physics energy engineering, surya university, tangerang, indonesia 86 department of renewable energy engineering, universitas prasetiya mulya, tangerang, indonesia 86 electrical engineering department, universitas negeri malang, malang, indonesia 11 electrical engineering postgraduate, electrical engineering department, universitas negeri malang, malang, indonesia 55 engineering physics study program institut teknologi bandung, bandung, indonesia 1 externship researcher of engineering physics study program institut teknologi bandung, bandung, indonesia 1 faculty of electrical and electronic engineering technology (ftkee), universiti teknikal malaysia melaka, melaka, malaysia 22 faculty of electrical engineering, universiti teknologi mara (uitm), selangor, malaysia 11 industrial design laboratory, art and design faculty, keimyung university, daegu, republic of korea 75 institute of thermal turbomachinery and machinery laboratory, university of stuttgart, stuttgart, germany 38 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 x instrumentation and control research group institut teknologi bandung, bandung, indonesia 1 intelligent power and advance energy system, electrical engineering department, universitas negeri malang, malang, indonesia 55 research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), bandung, indonesia 22, 30, 38, 45, 75, 95, 102, 111 research centre for geotechnology, indonesian institute of sciences (lipi), bandung, indonesia 111 research unit for clean technology, indonesian institute of science (lipi), bandung, indonesia 30 technical implementation unit for instrumentation development, indonesian institute of sciences (lipi), bandung, indonesia 102, 111 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xi journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kirikkale universitesi kırıkkale üniversitesi, ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xii dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, st., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. yusie rizal, phd cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh.tembalang, semarang 50275, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia suprapto, ph.d departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiii kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia alexander christantho budiman ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. ph.h. mustafa no. 23, bandung, jawa barat, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. rina ristiana technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. andry masri, m.sn department of product design, faculty of art and design, institut teknologi nasional jl. ph.h. mustofa no.23, bandung, jawa barat, indonesia dr. eng., aam muharam research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. anto tri sugiarto, m.eng technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. deni shidqi khaerudini, s.si.,m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xiv kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia aditya nugraha, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani,m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi azhari, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia veny luvita, m.t technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia irwan purnama m.sc.eng technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xv publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvi 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xvii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including:  honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty)  research misconduct (data fabrication)  duplicate or overlapping publication  fraudulent use of data  clear plagiarism  unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xviii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted.  heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot.  heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot.  heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket  heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket.  heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mevjournal.com/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xix presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xx instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points:  make sure you use uniform lettering and sizing of your original artwork.  preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier.  number the illustrations according to their sequence in the text.  use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 xxi  eps (or pdf): vector drawings. embed the font or save the text as 'graphics'.  tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi.  tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi.  tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not:  supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low.  supply files that are too low in resolution.  submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows  book: author, title. edition, editor , city, state or country: publisher, year, pages.  part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages.  periodical: author, “title”, journal, volume (issue), pages, month, year.  proceeding: author, “title”, in proceeding, year, pages.  unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year.  paten/standart: author, “title”, patent number, month day, year.  technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows:  book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file.  periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file.  papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file.  reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.48-59 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: b.m. arthaya et al., “design and kinematic analysis of a two-dof moving platform as a base for a car simulator,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 48-59, july 2022. design and kinematic analysis of a two-dof moving platform as a base for a car simulator bagus made arthaya a, *, raymond christian b, tua agustinus tamba a, dilek bilgin tükel c a mechatronics engineering department, faculty of industrial technology, parahyangan catholic university jalan ciumbuleuit 94, bandung, 40141, indonesia b faculty of mechanical and aerospace engineering, bandung institute of technology jalan ganesha 10, bandung, 40132, indonesia c software engineering department, dogus university dudullu osb mah. nato yolu cad. 265, 1 umraniye, istanbul, 34775, turkey received 5 march 2022; 1st revision 19 april 2022; 2nd revision 6 june 2022; accepted 24 june 2022; published online 29 july 2022 abstract the study starts by modeling a simple 2-dof (degrees of freedom) moving platform that employs two actuators to provide two kinds of rotational motion on the moving platform and each motion is driven by an electrical motor. a preliminary study to better understand motion generation is conducted by deriving a mathematical model of the platform. based on this model, the relationship between the rotations of the two driving motors and the pitch and roll movements of the platform is determined. the range of movements must be limited both in the pitch and roll planes to a certain maximum and minimum values of tilting angles. this preliminary design of the platform is introduced to demonstrate motions that might be experienced by the user in roll and pitch directions. the motion generated has fulfilled the constraint with respect to the vestibular system. results of experimental works show that the first motor angle between -26° and 27° is suitable for the roll plane; meanwhile, the angles range of -52° and 54° for the second motor is suitable for the pitch plane. furthermore, some simple experiments were conducted to examine the correctness of the model through the comparison between testing results obtained from simulation and experimental work. in the reported results, the moving platform was set to some initial poses and was driven to the home position and the recording showed acceptable results. this moving platform can later be used for more comprehensive experiments, i.e., vehicle dynamic testing, driving training purposes, and human factor analyses. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: human vestibular system; kinematic model; moving platform; pitch and roll planes; rotating encoder. i. introduction in recent years, advanced simulators are already well known in the field of computer science and engineering, as they are supported mainly by advanced computer technology development and thus are now significantly becoming indispensable in most engineering areas. the design and the use of simulation applications offer some benefits which can be obtained for obvious reasons, such as from flexibility, safety, and cost reduction points of view. in a simulation environment, the actors can try many aspects of the activity that must be researched or evaluated safely without worrying about dangerous things, as if these activities were performed directly in the real situation. along with the development of technology, a technology called mobile platforms or motion platforms for driving simulators emerged. a mobile platform is a tool that has a mechanism to simulate the translational and rotational movements of the user. this mobile platform structure can be used to simulate the vehicle motion and the dynamics such as shocks or vibrations and maneuvers in-car simulation. it has several different purposes, such as driver training, simulation of mitigation activities, research on driver behavior, car safety evaluation and emergency system, and even for some entertainment facilities. furthermore, this driving simulator must be equipped with several important * corresponding author. tel: +62-8112266092; fax: +62222032700 e-mail address: bagusart@unpar.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.48-59 https://dx.doi.org/10.14203/j.mev.2022.v13.48-59 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.48-59 https://dx.doi.org/10.14203/j.mev.2022.v13.48-59 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.48-59&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 49 information/signals so that the driver does not lose his sense of reality when controlling a car as in real driving situations. in addition to simulating vehicle movements, this motion platform can be used to complement racing games with hardware that provides a real driving experience. the simulator can further be used to simulate driver/pilot training purposes and experiences done by brookhuis in [1], for human factor analysis by kuiper et al. in [2], for evacuation simulations in the case of a tsunami by maruyama and sakaki in [3] as well as for evaluating the visual interface experiments of in-vehicle information system for elderly by gomez et al. [4]. simulators have been accepted widely by many researchers because they have made research activities easier. they can keep users away from the possibility of accidents or unwanted events. meanwhile, maruyama and sakaki [3] proposed a driving simulator for evacuation experiments in the case of a tsunami. this study developed a system equipped with 3d computer graphics installed in the driving simulator. the system consists of three lcds, a steering wheel, a brake, and acceleration pedals. an experiment was conducted with ten participants. the visual information about tsunami was close to reality and gave a better insight of the disaster without having to be physically in an unwanted situation. through this simulator platform development, gomez et al. [4] allowed the users to modify the configuration openly and flexibly, reconfigure and evaluate prototypes of safety and emergency systems, apply a variety of driving scenarios, and so on. users may also have the possibility to adapt with user-dedicated facilities, i.e., hardware and/or software when developing or evaluating new systems. two examples of the application of the driving simulator platform are presented, which may contribute to improve road safety. based on research by berthoz et al. [5], car simulators equipped with motion cues could provide a more realistic driving experience for users. in the experiment research, users with a car simulator that has a movement output can complete a slalom test simulation better than a simulator that does not have a movement output. the movement specifications of the moving platform should also be adapted to the human sense of balance. the human sense of balance is the vestibular system (vestibular nerve), and this system is located in the human inner ear. the vestibular system can detect the orientation of the head and the direction of the earth's gravity concerning the body [6]. both of this information is needed by the brain to maintain balance and body orientation while moving. meanwhile, hansson et al. [7] mentioned that tilting the cabin of a simulator platform gives rise to a perceived linear acceleration, which would not happen in reality. the practice called tilt coordination (tc) in combination with visual cues may be perceived as continuous linear acceleration. this must be considered in platform operations to avoid presenting false cues, motion sickness, and other negative effects. according to bringoux et al. [8], the limit of the vestibular system for sensing tilt (roll and pitch) is 6°. this figure determines the maximum allowable range of rotational motion of the moving platform. moreover, according to stratulat et al. [9], the limit of the vestibular system for sensing radial velocity is 3.7 deg/s. however, based on research by groen and bles [10], the movement of the car simulator will be more realistic when the entire car simulator platform is tilted with a radial speed that does not exceed 3 deg/s. most articles cited above did not explore the mechanical structure in detail and what other factors were concerned when developing the corresponding moving platform. mostly manufactured motion-simulator platforms are actuated using more than 3 actuators, such as in [11][12], and in some cases by using 6 actuators, such as the stewart platform [13]. some designs allowed translation effects that were introduced by arioui et al. [14] and even used a complicated cabling system to reach a very easy moving platform [15]. this makes the designs not simple to implement and manufacture. the only motion structure that is quite similar to this design is the one shown by alsina et al. in [16], where their mechanical platform is used as a motion generator that emulates pitch and roll movements typically measured along the catalan coast, but no mathematical formulations were derived. some other structures present the same (similar) ideas to produce a 2° motion using two actuators are shown by ahmad et al. in [17] and by bin mohd. nadiman in [18]. they all use a single supporting point almost in the lower-middle part of the platform as the pivot point. the existence of this pivot provides easy rotation around the x-axis (rolling) and y-axis (pitching), but this prevents the structure from having translational motion in any direction. as a consequence, these designs will not match if the future development is going to allow translational motions. as a mechatronic engineering school, we believe that the project of making a fully computerized controllable car simulator is a very suitable topic to show how mechatronics is involved in this kind of activity, starting from determining the user specifications and constraints, mechanical structure and mechanism, electronic and power, dynamics, and control, and finally evaluating the overall performance. mechatronics students or researchers with diverse backgrounds in the field of mechatronics can contribute, collaborate, and synergize themselves to find the most suitable solution. in general, the research question to be analyzed is what kind of platform is appropriate as a base for car simulation that can properly respond to any command to the actuators and can show the behavior of the moving-simulator platform. then the aim/objective is to make a platform capable of rotating in both roll and pitch planes and complying with the constraint of the vestibular boundary mechanism. in this study, a concept in which a car simulator platform, such as those used in a racing game simulation, is developed. its basic features are b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 50 evaluated, i.e., the range of rotation, the limit of rotation, motor speed, etc. ii. materials and methods the existing simulators mostly are fully controllable for performing the 6-dof (degrees of freedom) motion; therefore, the structures are most complicated. to begin with, a 2-dof moving platform is introduced. the model is discussed only from a kinematic point of view. the stages in developing this moving platform are shown in figure 1. firstly, the kinematic model of the platform and testing is developed. second, the dynamic mathematical model is derived and verified by numerical analysis. third, the control strategy to execute the motion commands is built. fourth, motion signals from a car racing game are extracted to be converted into motion commands. finally, the whole performance of this moving platform as a complete car simulator is tested from different points of view, even the evaluation of the vestibular boundary criteria. in the early stage of development reported in this study, the kinematic model of the moving platform is constructed, the mathematical model that relates the platform orientation (tilting angle) and actuating angle is calculated, and then some simple motion tests were conducted to verify the correctness of the model. a simple electronic circuit operates to measure the platform orientation and executes the desired actuator rotation angles. a. kinematic model development of the platform the moving platform, designed as a car simulator, has 2-dof, namely motions in roll and pitch directions. firstly, the model was designed on solidworks software, where the platform is supported in the center and two actuators are positioned underneath to perform actuation. the support is one pivot joint in the lower middle of the platform base. two dc motors are employed at two certain distances perpendicular to each other from the pivot to actuate the platform in two planes, each responsible for actuating 1-dof motion. two sets of serial links perform a slider-crank-like mechanism (connecting rod and crank in the form of a circular plate) to move the platform up and down. the 3d model of the proposed platform and its real structure, which is manufactured from a hollow steel bar, is shown in figure 2. to anticipate the free (3d) movement of the connecting rod between the motor disk and actuating point at the platform, a universal joint is introduced. the mechanism is arranged perpendicular to each other. this design aims to figure 1. five research stages in developing the complete moving platform figure 2. a 3d model of the moving platform and the manufacturing testbed b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 51 make the structure as simple as possible using only two actuators but is capable of showing the motions of a car simulator. furthermore, this design makes manufacturing easy and simplifies system analysis. the platform dimension has a length of 1500 mm and a width of 1200 mm; meanwhile, the free space between the platform and base is 400 mm. since the moving platform is analyzed as a two planes case, then the two planes are defined as follows: • the pitch plane is the x-z plane used to analyze the movement of the platform when tilting forward and backward (pitch rotation) • the roll plane is the y-z plane used to analyze the movement of the platform when tilting to the left and the right (roll rotation) platform motion in both planes will be defined completely in the same mathematical formulation, but the difference is only in the physical dimensions (values) of all corresponding variables. this makes the reader easier to understand the working of the mechanism. as mentioned earlier, there are two designs very similar to the one proposed in this article, i.e., the one by tiana-alsina et al. [16] and the other by nadiman [18]. the 3d model comparison of those three designs is depicted in figure 3. it is shown that the pivoted support in the lower middle of the platform prevents the translational motion in all directions from being happened. among them, the way to actuate the platform of nadiman [18] is the most complicated one, in which a combination of the motion of the two actuators will perform the roll and pitch motions. the position where the user/car driver sits when operating the platform is determined by calculating the center of gravity (cog) of the user’s side view. the location of the center will influence the reaction of the motor to perform the motion. the coordinates of the user's cog can be determined using the area approximation of the blue and red areas, as shown in figure 4. because the used area is in a digital image, the unit used in calculating this cog is the pixel. the origin point located at the bottom left of the cog obtained from this approach is (861,845) pixels. while capturing the picture, the user holds a scalable ruler. the maximum length will later be associated with the number of pixels measured for the ruler. from the picture examination, it is seen that 300 mm corresponds to 533 pixels. because the coordinates of the obtained cog are still in pixels, these coordinates need to be converted into millimeters. these coordinates are converted using a multiplying factor 𝑘𝑧, as defined in (1). the 𝑘𝑧 factor is obtained as follows: 𝑘𝑧 = 300 533 mm/p (1) figure 3. three similar designs to produce rolling and pitching rotation: (a) by tiana-alsina [16]; (b) proposed in this research; (c) by bin mohd. nadiman [18] figure 4. simplified body form of the user for calculating cog: (a) total area; (b) body area only b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 52 the calculated cog of the user on the x-z plane is (484,476) mm and is measured from the origin point. this figure will be mainly used in the dynamic analysis of the system (which will be examined in the next stage of the research, as mentioned earlier). the cog of the user in y-z is in the center plane. b. mathematical model of the motion platform the relationship between moving platform orientation and the rotation angle of the dc motor is the main concern in the mathematical formulation. in figure 5, all variables related to the physical dimension of the platform are defined. the radius (cd) of crank (wheel) is defined as r and the length of connecting rod (bc) is defined as l. meanwhile, a more specific relationship between them is defined, especially in relating the motor (𝛼) and the platform tilting (𝜃) angles in figure 6. the equation of the relationship between the motor rotation and the platform orientation is first derived based on kinematic relation. it is later used to simulate the movement of the moving platform. to define this relationship, the platform kinematic structure in figure 2 is simplified into simpler variable relations, as shown in figure 6. the red triangle (bcd) in figure 6 is analyzed to get the relationship between the platform and the motor angle (𝜃 and 𝛼). the height of the triangle is defined as 𝑚𝑣, the length of the base is defined as 𝑚ℎ, and the length of the hypotenuse is defined as 𝑚. their definition is a function of angle 𝜃 are shown in (2), (3), and (4): 𝑚ℎ(𝜃) = 𝑝𝑎 cos 𝜃 − 𝑝𝑏 + (ℎ𝑎 − 𝑡𝑎) sin 𝜃 (2) 𝑚𝑣(𝜃) = 𝑝𝑎 sin 𝜃 + 𝑡𝑏 − ℎ𝑏 + (𝑡𝑎 − ℎ𝑎) cos 𝜃 (3) 𝑚(𝜃) = �𝑚𝑣2(𝜃) + 𝑚ℎ 2(𝜃) (4) using the cosine rule, the angle 𝜃 is calculated in (5) or (6) as follows: cos[𝛼(𝜃) + 𝛽(𝜃)] = 𝑚ℎ 2(𝜃)+𝑚2(𝜃)−𝑚𝑣2(𝜃) 2𝑚ℎ(𝜃)𝑚(𝜃) (5) 𝛼(𝜃) = cos−1 �𝑚ℎ 2(𝜃)+𝑚2(𝜃)−𝑚𝑣2(𝜃) 2𝑚ℎ(𝜃)𝑚(𝜃) � − 𝛽(𝜃) (6) the measurement of the angle 𝛽 is calculated using the following cosine rule: cos 𝛽(𝜃) = 𝑟 2+𝑚2(𝜃)−𝑙2 2𝑟𝑚(𝜃) (7) 𝛽(𝜃) = cos−1 �𝑟 2+𝑚2(𝜃)−𝑙2 2𝑟𝑚(𝜃) � (8) the relationship between the motor angle and the platform angle 𝜃 is obtained by substituting (8) into (6). figure 5. side view of the platform figure 6. relation of dimension variable b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 53 𝛼(𝜃) = cos−1 �𝑚ℎ 2(𝜃)+𝑚2(𝜃)−𝑚𝑣2(𝜃) 2𝑚ℎ(𝜃)𝑚(𝜃) � − cos−1 �𝑟 2+𝑚2(𝜃)−𝑙2 2𝑟𝑚(𝜃) �(9) eventually, (9) can be used to analyze moving platform motion in roll and pitch plane by using inputs in the form of incremental values of the corresponding variables. c. simulation of the motion platform as mentioned earlier, (9) is used to simulate the motion of the platform using matlab software. the variable magnitudes used in this equation are 𝑙 = 320 mm , 𝑟 = 75 mm , ℎ𝑎 = 30 mm , ℎ𝑏 = 50 mm , 𝑡𝑎 = 50 mm, and 𝑡𝑏 = 350 mm. when analyzing the pitch plane, the variable values are 𝑝𝑎 = 575 mm and 𝑝𝑏 = 500 mm. in the roll plane, the variable values are 𝑝𝑎 = 325 mm and 𝑝𝑏 = 250 mm. 𝑝𝑎 and 𝑝𝑏 values were obtained from the best value of an iteration process, which gives a tilting angle on roll and pitch planes between -6° to 6°. this search was done by trial and error. the simulation was carried out by correlating tilting angle 𝜃 with actuating angle (𝛼) ranging from -100° to 80° for both roll and pitch planes. an increment of 0.1° for angle (𝜃) is fed to (9) and the corresponding angle (𝛼) is recorded. after running the simulation, the relation between tilting angle (𝜃) and actuating angle (𝛼) can be obtained. d. platform testing methods the process of testing the platform is done by actuating the dc motor within the angle range provided by the simulation. in this stage, the platform tilting angle is measured using the mpu6050 module mounted on the platform, which is capable of measuring velocity, orientation, acceleration, displacement, and other motion-like features. the mpu6050 sensor is used to detect the platform tilting angle directly. meanwhile, saputra et al. [19] introduced a comprehensive explanation of using inertial measurement unit (imu) to calculate absolute and relative attitudes for controlling joint angles of a pan-tilt mechanism. rafiq et al. [20] used the same mpu6050 module to detect the tilting angles in the development of the smartphone gimbal. zhang et al. [21] showed the implementation of imu for outdoor applications where estimation of absolute attitude is compared with a kinematic model of motion, while albaghdadi and ali [22] introduced detailed methods to overcome measurement error caused by vibration when using the mpu6050 module. jefiza et al. [23] and al-dahan et al. [24] used the mpu6050 module to detect the fall of the elderly when walking, while rifajar and fadlil [25] used it to detect the fall of a dancing robot by monitoring the acceleration of rotational motion. the approach to measuring joint angles in this research is different, where the measured orientation is used to calculate joint angles of the dc actuators based on (9). the tcrt5000 sensor (rotating encoder) is placed in front of the segmented grid of the circular plate (motor disk), as shown in figure 7. the encoder (tcrt 5000 sensor) is used to detect the motor angle by counting the number of black-white grids that pass in front of the optocoupler. for one complete rotation of the rotating disk, 65 black grids correspond to 5.54° reading accuracy. this is a good example of the implementation of a low-cost selfmade rotating drum encoder for mechatronics or other engineering students. iii. results and discussions a. kinematic model of the platform from figure 2, one can see clearly a very rigid structure of the moving platform and the dimension is big enough for a person who will drive the platform. it is easy to model the platform in solidworks by utilizing the 3d solid model to make the platform. having done the 3d model, dimensions and all connections between frames are used as a reference to manufacturing the platform. the material used is a hollow steel bar and the connection between frames is done by welding. figure 7. rotating encoder and its mounting b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 54 the slider-crank-like mechanism converts the motor rotation into a vertical translation motion at the connecting pin at the platform. two vertical thick plastic disks acting as the crank arms are mounted between dc motor axes and the connecting rod. in the end, this motion generates the rolling and the pitching motion in their respective planes. this mechanism is the realization of a fourlinkage mechanism, where the rotation of the first link is directly followed and converted by the third link. because of the physical dimensions, the magnitude of the tilting angle on each plane (roll and pitch) differs, directly determining the working range of each driving motor. as the platform is actuated by two actuators 90° from each other, this mechanism works not always in a fixed plane but always in a free-oriented plane. to deal with this condition, a universal joint has to be implemented to accommodate the connection of a rigid bar between the free-oriented plane and a fixed-oriented plane. this is a common mechanical engineering practice. b. mathematical model of the motion platform a mathematical model is essential to find the exact correlation between the input signal (actuator motion) and output (platform tilting angles). for this motion platform, actuating angle as input corresponds directly to the platform tilting angles with respect to all physical parameters of the platform. equation (9) has determined the relation between the tilting angle and the motor angle. the magnitude of these tilting angles depends directly on the base distance of the actuator (𝑝𝑏), the linear distance of the pivot ( 𝑝𝑎 ), and the length of connecting rod (𝑙). because the tilting angle of the platform must be limited due to the vestibular boundary conditions, the actuating angle (𝛼) is restricted as well. the range of actuating angles for generating roll motion is -26° to 27°, and for generating roll motion is -52° to 54° (figure 8). this angle will determine the length of a moment arm, which later directly defines the magnitude of the motor torque required. one can understand the smaller the angle range, the smaller the torque required. the angle ranges in this design are good as the longest moment arm exists when the motor angle is 90°. it can be clearly understood based on statics analysis in engineering mechanics. c. motion command system of the platform the platform motion is controlled by an arduino uno microcontroller and the dc motors are driven by a 12 v power supply. to control the motor speed and directions, monster moto shield vnh2sp30 driver is employed. the driver is controlling the voltage polarity and magnitude to be sent to both motors based on the signal information from the arduino. the circuitry for controlling the motors is depicted in figure 8. motor speed is set to 20 % of maximum magnitude (in the range of integer numbers: 0 to 255) and there are some default commands to move cw, ccw, and brake. a simple program coding is prepared to let a motor move in a certain direction at a certain speed. an example of the coding is as follows: motorgo(motor_1,ccw,55); where motor_1 means motor 1 is active, ccw means motor rotation (counterclockwise), and 55 means motor speed (speed range of 0 to 255). a simple if-then rule is used to command the motor moves to a certain position, such as: if (in position within tolerance) motor stops else if (position > target) run motor cw else if (position < target) run motor ccw all these codes are enough to command the motors to move in any position within the angle range values based on the simulation. d. experimental results: accuracy and sensitivity of the platform the process of testing the platform is firstly done by performing simulation separately between roll and pitch planes, wherein incremental angle input (𝜃) is fed to (9). the range of angle input (𝜃) is figure 8. electronic circuit for controlling the dc motor b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 55 between -15° to 12.5° for the roll plane and -8.5° to 6.9° for the pitch plane. the function of angle (𝜃) in respect to angle (𝛼) is plotted as depicted in figure 9. the first simulation shows that the minimum tilting angle of -6° was realized by -26° and the maximum tilting angle of 6° was realized by 27° in the roll plane. the second shows that the minimum tilting angle of -6° was realized by -52° and the maximum angle tilting of 6° was realized by 54° in the pitch plane. those numbers of actuating angles are now obtained and can be used as preliminary reference points. the platform motion was examined for three cycles of execution, and both angles (𝜃 and 𝛼) were measured simultaneously. after then, the best result between -100° to 80° rotation of actuating motor is displayed in figure 10. the sensor reading (𝛼) lies very close to the simulation result of the tilting angle (𝜃), then it proves that the mathematical model of the platform is correct or closely related to the measurement. from figure 10, this range is delivered by two different motor rotations as the physical structure (𝑝𝑎, 𝑝𝑏, and 𝑙) of each mechanism differs. this output range will become the maximum allowable output produced by both dc motors. the first experiment in figure 10(a) shows that the minimum tilting angle of -6° was realized by 30° of actuation and the maximum tilting angle of 6° was realized by 32° of actuation in the roll plane. the second shows that the minimum tilting angle of -6° was realized by -60° of actuation and the maximum angle tilting of 6° of actuation was realized by 61° in the pitch plane. figure 10 also shows that the range resulting from simulation can be considered a safe magnitude of actuator angles. another aspect used to show the discrepancy between the simulation and experimental result (figure 10) is the comparison of areas under the span that corresponds to the platform angle range from -6° to 6°. from the pitch plane, the area calculated from the simulation is 344.14 units and from the experiment is 331.32 units. so, we can roughly say that the error (𝑒𝑝) is: 𝑒𝑝 = 344.14−331.32 344.14 = 0.0373 = 3.73 % (10) from the roll plane, the area calculated from the simulation is 164.16 units and from the experiment is 172.78 units. so, we can roughly say that the error (𝑒𝑟) is: 𝑒𝑟 = 172.78−164.16 172.78 = 0.0499 = 4.99 % (11) the previously two error values suggested that the mathematical model of the platform conforms to the real physical structure. an error of less than 5 % is acceptable in the engineering field, and it can be minimized if not eliminated by the control algorithm designed for this purpose in future work. regarding the platform motion in the roll plane in figure 10(a), the two graphics are in line very closely, while in the pitch plane in figure 10(b), they lay apart from each other. it is logically understood as the sensitivity of motion in the roll plane is higher due to the base and supporting distances. there are still some discrepancies between the motor angle readings and angles recorded in the simulation when performing two directions of tilting. this is mainly figure 9. simulation result of moving platform: (a) in roll-plane; (b) in pitch-plane figure 10. comparison between platform tilting angle and motor engle in roll (left) and pitch (right) planes: (a) in roll-plane; (b) in pitch-plane b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 56 caused by the inaccuracy of the rotating encoder used to measure the motor angle. we point out that a homemade encoder often shows inaccuracy in many cases. furthermore, some related experiments were also conducted, to show how the mechanism will bring the platform from one arbitrary pose to zero position. the results of these experiments are depicted in figure 11. there are four initial positions of the platform as detailed below: • roll plane at 11.46° and pitch plane at -4.81° • roll plane at -10.25° and pitch plane at 6.61° • roll plane at 10.21° and pitch plane at -6.58° • roll plane at 11.49° and pitch plane at 5.96° in the beginning, the zero position of the platform (upward orientation) is determined using spirit level both in the roll as well as in pitch planes. the output reading of the mpu6050 fluctuated between -0.67° to 0.68° in the rolling plane and between -0.56° to 0.56° in the pitch plane caused by the noise in the sensor electronics, which proves the existence of the sensing characteristic, that is, the floating phenomenon. starting from four different poses, the motors gradually move to their home positions, respectively. the platform movement was established and completed at once, both in roll and pitch planes. the completion time of four executions was recorded as for 1) 3.4 s; 2) 3.8 s; 3) 3.6 s; and 4) 3.4 s, respectively. the maximum rotational speed of the platform achieved from all these experimental motions is 8.86 deg/s. other experiments were carried out to examine the motion of the platform moving to a certain desired orientation. the top two graphics in figure 12 show the course of tilting angle from the home position to -10° and then to 8° orientation in the roll planes. the bottom two graphic shows the course of tilting angle from the home position to 6° and then to -5° in the pitch plane. the time-traveling shows a clear consistency that a bigger tilting angle requires a longer execution time. the maximum speed of the platform rotation achieved in all these tests is 20 deg/s. the objective to make a platform having roll and pitch rotations has been achieved and at once complying with the constraint related to the mechanism of vestibular boundary criteria. comparing to other studies shown in [11][12][13], this study has much less capability and flexibility. those cited works can change orientation in space while translating in any direction, but the models are much more complicated to analyze and implement. the objective of the design in this study is only to provide 2-dof motion, i.e., roll and pitch rotations. the main advantage is a simpler design and mathematical analysis, cheaper alternatives, and easier use and maintenance. each platform direction may have a different speed due to its physical construction, meaning that each direction will have a different rotational speed. more attention must be paid as it is related to the boundary conditions of the vestibular system. for the same tilting angle (figure 13), the rotational effect of the pitch will be much more significant, as the offset of cog position is small (figure 13(a)) in the pitch plane compared to the rotational effect of roll (figure 13(b)). this fact makes the pitching effect should be more pronounced for the user than the figure 11. four different starting poses to run to the home position: (1) from 11.46° and -4.81°; (2) from -10.25° and 6.61°; (3) from 10.21° and 5.58°; (4) from 11.49° and 5.96° b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 57 rolling effect. the illustration of those two cases is depicted in figure 13. the future work of this research is to develop the dynamic model of the moving platform. this model is important as the moving mass has a very big impact on the motion of the structure. knowing the dynamic model, the motor torque required to move the platform can be determined more precisely and accurately. this point is the consequence of the cog position concerning the pivot point that alters corresponding to the tilting angle. this phenomenon must be taken care of in developing the motor controller. iv. conclusion in this study, the preliminary design of a 2-dof moving platform has been introduced to demonstrate motions that might be experienced by the user (car driver) in roll and pitch directions. the figure 12. two running tests from zero to two desired positions: (a) to -10° and 8° (1st run); (b) to -10° and 8° (2nd run); (c) to 6° and -5° (1st run); (d) to 6° and -5° (2nd run) figure 13. position of cog which will influence the dynamic effect: (a) in pitch-plane; (b) in roll-plane b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 58 limited range of motion is determined to fulfill the rules of the vestibular system, where humans can only sense the tilting angle of 6°. to obey this rule, the first motor angle between -26° and 27° is suitable for the roll plane, while the angles range of 52° and 54° is suitable for the pitch plane. a kinematic model of the platform is developed, and the resulting mathematical expression generates the relation between the driving motor angle and the tilting angle of the platform. simulation and experimental results show a good fit between them. this demonstrates that the model is acceptable based on the orientation error on both planes being less than 5 %. four different experiments were carried out to show the ability of this design to move from any pose in the roll and pitch plane to the home position. depending on the magnitude of the offset, the traveling time still needs to be justified to ensure that it will give the appropriate radial velocity. but from some experiments conducted above, the maximum rotational speed of the platform is 20 deg/s. as mentioned earlier, the acceptable radial velocity of the human vestibular system should not be higher than 3.7 deg/s, as suggested by previous work. it concludes that the speed in those experiments is not suitable for human application, but the objective of this work is not the speed criteria but the degree of orientation. this issue will be dealt with in future work. acknowledgement the authors gratefully acknowledge the faculty of industrial technology of parahyangan catholic university for providing research facilities to support this research. declarations author contribution b. m. arthaya: writing original draft, writing review & editing, conceptualization, formal analysis, investigation, visualization, supervision. r. christian: writing review & editing, model creation, simulation, formal analysis, investigation, validation, data curation, visualization. t. a. tamba: writing review & editing, formal analysis, investigation, investigation, funding acquisition. d. b. tükel: writing review & editing, resources, software. funding statement this research is supported by kementerian pendidikan, kebudayaan, riset, dan teknologi of the republic of indonesia under the pdupt research grant scheme #iii/lppm/2022-06/112-pe and by the lppm of parahyangan catholic university under internal research grant schem #iii/lppm/2022-02/81-p. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] k. a. brookhuis, “driving simulator,” in international encyclopedia of transportation, elsevier, amsterdam, the netherlands, pp. 14-19, 2021. [2] o. x. kuiper, j. e. bos, c. diels, and k. cammaerts, “moving base driving simulators’ potential for carsickness research,” applied ergonomics, 81, 102889, pp. 1-5, 2019. [3] y. maruyama and s. sakaki, “development of driving simulator for the experiment of tsunami evacuation using automobile,” in proc. of the 7th international conference on asian and pacific coasts (apac), pp. 454-459, 2013. [4] a. e. gomez, t. c. dos santos, c. m. massera; a. m. neto, and d. f. wolf, “driving simulator platform for development and evaluation of safety and emergency systems,” computer science: computers and society, cornell university, 2018. [5] a. berthoz, w. bles, h. bülthoff, b. c. grácio, p. feenstra, n. filliard, r. huhne, a. kemeny, m. mayrhofer, m. mulder, h. nusseck, p. pretto, g. reymond, r. schlusselberger, j. schwandtner, h. teufel, b. vailleau, m. m. van paassen, m. vidal, and m. wentink, “motion scaling for high-performance driving simulators,” in ieee transactions on human-machine systems, 43 (3), pp. 265–276, 2013. [6] s. khan and r. chang, “anatomy of the vestibular system: a review,” in neuro rehabilitation, vol. 05, no. 32, pp. 437–443, 2013. [7] p. hansson, a. stenbeck, a. kusachov, f. bruzelius, and b. augusto, “prepositioning of driving simulator motion systems,” int. j. vehicle systems modelling and testing, vol. 10, no. 3, pp. 288–304, 2015. [8] l. v. bringoux, l. marin, p. a. barraud, and c. raphel, “contribution of somesthetic information to the perception of body orientation in the pitch dimension,” in the quarterly journal of experimental psychology section a, vol. 56, no. 5, pp. 909–923, 2003. [9] a. stratulat, v. roussarie, j. l. vercher, and c. bourdin, “improving the realism in motion-based driving simulators by adapting tilt-translation technique to human perception,” in ieee virtual reality, pp. 47-50, 2011. [10] e. groen and w. bles, “how to use body tilt for the simulation of linear self-motion,” journal of vestibular research, vol. 14, no. 5, pp. 375–385, 2004. [11] n. c. ruiz-hidalgo, a. blanco-ortega, a. abúndez-pliego, j. colín-ocampo, and m. arias-montiel, “design and control of a novel 3-dof parallel robot,” in proc. international conference on mechatronics, electronics and automotive engineering, pp. 66-71, 2016. [12] x. hu, f. li, and g. tang, “kinematics analysis of 3upu_up coupling parallel platform in the marine environment,” ieee access, vol. 8, pp. 158142-158151, 2020. [13] a. adel, m. mahmoud, n. sayed, o. hisham, o. ossama, p. adel, y. ayman, m. i. awad, shady a. maged, s. m. umer, h. iqbal, and h. f. maqbool, “design of a 6-dof hydraulic vehicle driving simulator,” in proc. int. conf. on innovative trends in communication and computer engineering, egypt, pp. 170175, 2020. [14] h. arioui, s. hima, l. nehaoua, r. j. v. bertin, and s. espié, “from design to experiments of a 2-dof vehicle driving simulator,” ieee transactions on vehicular technology, 60 (2, pp. 357-368), 2011. [15] m. v. k. reddy, “orientability of the moving platform in planar cable robots,” master thesis, mechanical engineering, indian institute of science, bengaluru – 560012, india, 2019. [16] j. tiana-alsina, m. a. gutierrez, i. wurth, j. puigdefabregas, and f. rocadenbosch, “motion compensation study for a floating doppler wind lidar,” in proc. ieee international geoscience and remote sensing symposium (igarss), pp. 5370-5382, 2015. [17] n. ahmad, m. k. a. kholdun, h. zulkefle, m. f. abdullah, d. kamaruzzaman, and n. e. abdullah, “2 degree of freedom (dof) motor control for motion simulation,” in proc. ieee 12th control and system graduate research colloquium (icsgrc 2021), pp. 259-264, 2021. [18] m. n. a. bin mohd nadiman, “design and development of 2dof motion simulator for paramotor trike,” master thesis, faculty of engineering, university of malaya, 2020. https://mev.lipi.go.id/ https://doi.org/10.1016/b978-0-08-102671-7.10650-5 https://doi.org/10.1016/b978-0-08-102671-7.10650-5 https://doi.org/10.1016/b978-0-08-102671-7.10650-5 https://doi.org/10.1016/j.apergo.2019.102889 https://doi.org/10.1016/j.apergo.2019.102889 https://doi.org/10.1016/j.apergo.2019.102889 https://core.ac.uk/download/pdf/25492921.pdf https://core.ac.uk/download/pdf/25492921.pdf https://core.ac.uk/download/pdf/25492921.pdf https://core.ac.uk/download/pdf/25492921.pdf https://doi.org/10.48550/arxiv.1802.04104 https://doi.org/10.48550/arxiv.1802.04104 https://doi.org/10.48550/arxiv.1802.04104 https://doi.org/10.48550/arxiv.1802.04104 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.1109/tsmc.2013.2242885 https://doi.org/10.3233/nre-130866 https://doi.org/10.3233/nre-130866 https://doi.org/10.3233/nre-130866 https://doi.org/10.1504/ijvsmt.2015.070165 https://doi.org/10.1504/ijvsmt.2015.070165 https://doi.org/10.1504/ijvsmt.2015.070165 https://doi.org/10.1504/ijvsmt.2015.070165 https://doi.org/10.1080/02724980245000016 https://doi.org/10.1080/02724980245000016 https://doi.org/10.1080/02724980245000016 https://doi.org/10.1080/02724980245000016 https://doi.org/10.1080/02724980245000016 https://doi.org/10.1109/vr.2011.5759435 https://doi.org/10.1109/vr.2011.5759435 https://doi.org/10.1109/vr.2011.5759435 https://doi.org/10.1109/vr.2011.5759435 https://doi.org/10.3233/ves-2004-14503 https://doi.org/10.3233/ves-2004-14503 https://doi.org/10.3233/ves-2004-14503 https://doi.org/10.1109/icmeae.2016.021 https://doi.org/10.1109/icmeae.2016.021 https://doi.org/10.1109/icmeae.2016.021 https://doi.org/10.1109/icmeae.2016.021 https://doi.org/10.1109/icmeae.2016.021 https://doi.org/10.1109/access.2020.3020095 https://doi.org/10.1109/access.2020.3020095 https://doi.org/10.1109/access.2020.3020095 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/itce48509.2020.9047787 https://doi.org/10.1109/tvt.2010.2090675 https://doi.org/10.1109/tvt.2010.2090675 https://doi.org/10.1109/tvt.2010.2090675 https://doi.org/10.1109/tvt.2010.2090675 https://mecheng.iisc.ac.in/cnuiisc/studentstheses/mtech(res)/gka/2019_mvikranthkumarreddy.pdf https://mecheng.iisc.ac.in/cnuiisc/studentstheses/mtech(res)/gka/2019_mvikranthkumarreddy.pdf https://mecheng.iisc.ac.in/cnuiisc/studentstheses/mtech(res)/gka/2019_mvikranthkumarreddy.pdf https://doi.org/10.1109/igarss.2015.7327051 https://doi.org/10.1109/igarss.2015.7327051 https://doi.org/10.1109/igarss.2015.7327051 https://doi.org/10.1109/igarss.2015.7327051 https://doi.org/10.1109/igarss.2015.7327051 https://doi.org/10.1109/icsgrc53186.2021.9515297 https://doi.org/10.1109/icsgrc53186.2021.9515297 https://doi.org/10.1109/icsgrc53186.2021.9515297 https://doi.org/10.1109/icsgrc53186.2021.9515297 https://doi.org/10.1109/icsgrc53186.2021.9515297 https://scholar.google.com/scholar?hl=en&as_sdt=0%2c5&q=design+and+%20development+of+2-dof+motion+simulator+for+paramotor+trike&btng=%5d https://scholar.google.com/scholar?hl=en&as_sdt=0%2c5&q=design+and+%20development+of+2-dof+motion+simulator+for+paramotor+trike&btng=%5d https://scholar.google.com/scholar?hl=en&as_sdt=0%2c5&q=design+and+%20development+of+2-dof+motion+simulator+for+paramotor+trike&btng=%5d b.m. arthaya et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 48-59 59 [19] h. m. saputra, z. abidin, and e. rijanto, “imu application in measurement of vehicle position and orientation for controlling a pan-tilt mechanism,” journal of mechatronics, electrical power, and vehicular technology (mev), 04, (1), pp. 41-50, 2013. [20] a. a. rafiq, w. n. rohman, and s. d. riyanto, “development of a simple and low-cost smartphone gimbal with mpu-6050 sensor,” journal of robotics and control (jrc), 1(4), pp. 136140, 2020. [21] y. zhang, k. song, j. yi, p. huang, z. duan, and q. zhao, “absolute attitude estimation of rigid body on moving platform using only two gyroscopes and relative measurements,” ieee/asme transactions on mechatronics, 23, (3), pp. 1350–1361, 2018. [22] a. f. albaghdadi and a. a. ali, “an optimized complementary filter for an inertial measurement unit contain mpu6050 sensor,” iraqi journal for electrical and electronic engineering, 15, (2), pp. 71-77, 2019. [23] a. jefiza, e. pramunanto, h. boedinoegroho, and m. h. purnomo, “fall detection based on accelerometer and gyroscope using back propagation,” in proc. eecsi 2017, pp. 19-21. [24] z. t. al-dahan, n. k. bachache, and l. n. bachache, “design and implementation of fall detection system using mpu6050 arduino,” springer international publishing switzerland, pp. 180–187, 2016. [25] i. rifajar and a. fadlil, “the path direction control system for lanange jagad dance robot using the mpu6050 gyroscope sensor,” international journal of robotics and control, pp. 2740, 2021. https://doi.org/10.14203/j.mev.2013.v4.41-50 https://doi.org/10.14203/j.mev.2013.v4.41-50 https://doi.org/10.14203/j.mev.2013.v4.41-50 https://doi.org/10.14203/j.mev.2013.v4.41-50 https://doi.org/10.14203/j.mev.2013.v4.41-50 https://doi.org/10.18196/jrc.1428 https://doi.org/10.18196/jrc.1428 https://doi.org/10.18196/jrc.1428 https://doi.org/10.18196/jrc.1428 https://doi.org/10.1109/tmech.2018.2811730 https://doi.org/10.1109/tmech.2018.2811730 https://doi.org/10.1109/tmech.2018.2811730 https://doi.org/10.1109/tmech.2018.2811730 https://doi.org/10.1109/tmech.2018.2811730 https://doi.org/10.37917/ijeee.15.2.8 https://doi.org/10.37917/ijeee.15.2.8 https://doi.org/10.37917/ijeee.15.2.8 https://doi.org/10.37917/ijeee.15.2.8 https://doi.org/10.1109/eecsi.2017.8239149 https://doi.org/10.1109/eecsi.2017.8239149 https://doi.org/10.1109/eecsi.2017.8239149 https://doi.org/10.1007/978-3-319-39601-9_16 https://doi.org/10.1007/978-3-319-39601-9_16 https://doi.org/10.1007/978-3-319-39601-9_16 https://doi.org/10.1007/978-3-319-39601-9_16 https://doi.org/10.31763/ijrcs.v1i1.225 https://doi.org/10.31763/ijrcs.v1i1.225 https://doi.org/10.31763/ijrcs.v1i1.225 https://doi.org/10.31763/ijrcs.v1i1.225 introduction ii. materials and methods a. kinematic model development of the platform b. mathematical model of the motion platform c. simulation of the motion platform d. platform testing methods iii. results and discussions a. kinematic model of the platform b. mathematical model of the motion platform c. motion command system of the platform d. experimental results: accuracy and sensitivity of the platform iv. conclusion acknowledgement declarations author contribution funding statement competing interest additional information references mev mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.57-64 development of swept-sine excitation control method to minimize the frf measurement error pengembangan metode pengontrolan eksitasi swept-sine untuk meminimalisasi kesalahan pengukuran frf asmara yanto a, *, zainal abidin b a teknik mesin, fakultas teknologi industri itp jl gajah mada kandis nanggalo, padang, indonesia b teknik mesin, fakultas teknik mesin dan dirgantara – itb jl ganesha 10, bandung 40132, indonesia received 31 may 2012; received in revised form 29 august 2012; accepted 31 august 2012 published online 18 december 2012 abstract shaker excitation in frf (frequency response function) measurement of a testing system can be controlled by using sweptsine signal source in a signal generator and it is called with swept-sine excitation. frf’s magnitude error of the system which is obtained from the frf measurement using swept-sine excitation depends on swept function of swept-sine signal. in this paper, swept-sinesignals using linear and s535 swept functions have been simulated to controlling swept-sine excitation in the frf measurement of sdof (single degree of freedom) system. linear swept is swept function of swept-sine signal which is often used in the frf measurement and s535swept is a swept function has been developed in this paper. based on simulation results, the frf’s magnitude error at system’s resonant frequency which was obtained from the frf measurement using linear sweptsine excitation can be minimized by redoing the frf measurement using s535 swept-sine excitation. key words: frf, swept-sine, linear swept, s535 swept, magnitude. abstrak eksitasi shaker pada pengukuran frf (fungsi respon frekuensi) dari suatu sistem uji dapat dikontrol dengan sinyal sweptsine yang bersumber dari sebuah generator sinyal dan disebut dengan eksitasi swept-sine. kesalahan magnitudo frf sistem yang diperoleh dari pengukuran frf dengan eksitasi swept-sine bergantung kepada fungsi swept dari sinyal swept-sine. pada makalah ini, sinyal swept-sine dengan fungsi linear swept dan s535 swept telah disimulasikan untuk mengontrol eksitasi sweptsine pada pengukuran frf sistem 1-dk (satu derajat kebebasan). linear swept adalah fungsi swept dari sinyal swept-sine yang sering digunakan pada pengukuran frf dan s535 swept adalah sebuah fungsi swept yang dikembangkan pada makalah ini. berdasarkan hasil simulasi, kesalahan magnitudo frf pada frekuensi resonansi sistem yang diperoleh dari pengukuran frf dengan eksitasi linear swept-sine dapat diminimalisasi dengan mengulang kembali pengukuran frf dengan eksitasi s535 swept-sine. kata kunci: frf, swept-sine,linear swept, s535 swept, magnitudo. i. pendahuluan pengukuran frf (fungsi respon frekuensi) dengan eksitasi shaker membutuhkan perangkat pengeksitasi yang terdiri atas generator sinyal, penguat daya, shaker, dan alat penghubung shaker ke sistem uji (stinger) [1-4]. gaya eksitasi yang dihasilkan oleh shaker bersumber dari sinyal pengontrol eksitasi yang terdapat pada generator sinyal. salah satu dari beberapa sinyal pengontrol eksitasi yang sering digunakan pada pengukuran frf adalah sinyal swept-sine. sinyal swept-sine adalah sinyal sinusoidal dengan amplitudo tertentu dan memiliki kandungan frekuensi yang berubah terhadap waktu [4-6]. fungsi yang mengekspresikan hubungan frekuensi sinyal swept-sine terhadap waktu disebut dengan fungsi swept dan parameter yang menyatakan laju perubahan frekuensi sinyal swept-sine disebut dengan swept rate. harga swept rate bergantung * corresponding author. tel: +62-751-443317 e-mail: asmarayanto@yahoo.com http://dx.doi.org/10.14203/j.mev.2012.v3.57-64 a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 58 kepada span frekuensi dan waktu swept pada fungsi swept. gaya eksitasi yang dihasilkan oleh shaker dengan cara mengontrolnya dengan menggunakan sinyal swept-sine disebut dengan eksitasi swept-sine. magnitudo frf sistem uji yang diperoleh dari pengukuran frf dengan eksitasi swept-sine disebut dengan magnitudo frf swept-sine. beberapa metode eksitasi swept-sine pada pengukuran frf secara mimo (multiple input multiple output) dapat dilihat pada referensi [713]. berdasarkan referensi ini, eksitasi swept-sine diterapkan kepada sistem uji dengan menggunakan beberapa shaker. setiap shaker menghasilkan eksitasi swept-sine dengan swept rate yang berbeda satu sama lain. untuk memperoleh magnitudo frf yang teliti pada frekuensi resonansi sistem yang terendah, sekurang-kurangnya satu dari beberapa eksitasi swept-sine yang diterapkan tersebut harus mengandung swept rate yang lambat. pembahasan mengenai pengaruh harga swept rate pada pengukuran frf dengan eksitasi swept-sine secara siso (single input single output) dapat dilihat pada referensi [14-15]. berdasarkan referensi ini, eksitasi swept sine pada pengukuran frf sistem uji akan menghasilkan magnitudo frf yang teliti pada frekuensi resonansi sistem apabila memiliki swept rate yang lambat. tetapi, cara ini membutuhkan waktu swept yang panjang dan menghasilkan jumlah data yang banyak. berdasarkan referensi [7-15], pengukuran frf dengan eksitasi swept-sine yang memiliki swept rate yang semakin cepat menghasilkan magnitudo frf pada frekuensi resonansi sistem dengan kesalahan yang semakin besar. oleh karena itu, pada makalah ini dikembangkan suatu metode untuk meminimalisasi kesalahan magnitudo frf yang diperoleh dari pengukuran frf dengan eksitasi swept-sine yang memiliki swept rate yang cepat. eksitasi swept-sine untuk span frekuensi dan waktu swept tertentu yang semula dikontrol dengan sinyal linear swept-sine, dikontrol kembali dengan sinyal s535 swept-sine. span frekuensi dan waktu swept pada eksitasi s535 swept-sine dipertahankan sama dengan span frekuensi dan waktu swept pada eksitasi linear swept-sine. sinyal s535 swept-sine terdiri atas tiga fungsi swept yang saling menyambung untuk memenuhi span frekuensi eksitasi. fungsi swept pertama adalah swept polinomial orde-5 untuk frekuensi eksitasi di bawah daerah frekuensi resonansi sistem, fungsi swept kedua adalah swept polinomial orde-3 untuk frekuensi eksitasi disekitar frekuensi resonansi sistem, dan fungsi swept ketiga adalah swept polinomial orde-5 untuk frekuensi eksitasi di atas daerah frekuensi resonansi sistem. eksitasi swept-sine yang dikontrol dengan sinyal linear swept-sine dan s535 swept-sine disimulasikan secara numeric pada pengukuran frf sistem 1-dk (satu derajat kebebasan). ketelitian magnitudo frf sistem yang dihasilkan berdasarkan harga kesalahan magnitudo frf swept-sine terhadap magnitudo frf teoritik di frekuensi resonansi sistem. ii. metodologi skema pengukuran frf dengan eksitasi swept-sine ditunjukkan oleh gambar 1. sedangkan model simulasi pengukuran frf dengan eksitasi swept-sine ditunjukkan oleh gambar 2. simulasi pengontrolan eksitasi sweptsine pada pengukuran frf diawali dengan proses penentuan magnitudo frf teoritik sistem 1-dk gambar 1. skema pengukuran frf dengan eksitasi swept-sine. a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 59 dengan parameter masukan sistem berupa massa, ms (kg), peredam, c (ns/m), dan kekakuan, ks (n/m). pada proses ini, harga frekuensi pribadi, fn(hz), dan rasio redaman, 𝜁𝜁 , dihitung terlebih dahulu masing-masing dengan: 𝑓𝑓𝑛𝑛 = 1 2𝜋𝜋 � 𝑘𝑘𝑠𝑠 𝑚𝑚𝑠𝑠 (1) 𝜁𝜁 = 𝑐𝑐 4𝜋𝜋𝑚𝑚𝑠𝑠𝑓𝑓𝑛𝑛 (2) magnitudo frf teoritik sistem 1-dk, |hteo(f)| (m/n), diperoleh dengan |𝐻𝐻𝑡𝑡𝑡𝑡𝑡𝑡 (𝑓𝑓)| = 1 𝑘𝑘 1 ��1−� 𝑓𝑓 𝑓𝑓𝑛𝑛 � 2 � 2 +�2𝜁𝜁 𝑓𝑓 𝑓𝑓𝑛𝑛 � 2 (3) frekuensi resonansi, fr(hz), diperoleh dari kurva |hteo(f)| di mana fr adalah frekuensi pada harga maksimum dari |hteo(f)|. proses selanjutnya adalah analisis kesalahan magnitudo frf swept-sine. perbedaan magnitudo frf teoritik pada fr, |hteo(fr)|, dengan magnitudo frf swept-sine pada fr, |hss(fr)|, yang merupakan keluaran dari komparator dan kesalahan magnitudo referensi, 𝜀𝜀0 (%), merupakan masukan pada proses ini. persentase kesalahan |hss(fr)| yang dinotasikan dengan 𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 ) diekpresikan dengan: 𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 ) = |𝐻𝐻𝑡𝑡𝑡𝑡𝑡𝑡 (𝑓𝑓𝑟𝑟 )|−|𝐻𝐻𝑆𝑆𝑆𝑆 (𝑓𝑓𝑟𝑟)| |𝐻𝐻𝑡𝑡𝑡𝑡𝑡𝑡 (𝑓𝑓𝑟𝑟)| 100% (4) pada inisiasi simulasi, |hss(fr)| = 0 sehingga harga 𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 ) = 100%. harga ( 𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 )/𝜀𝜀0 )>1 merupakan indikator untuk proses simulasi pengontrolan eksitasi swept-sine pada pengukuran frf secara iteratif. a. fungsi swept pengontrolan eksitasi swept-sine berawal dari proses di generator swept. pada proses ini, parameter masukan adalah parameter swept berupa frekuensi awal, f0 (hz), frekuensi akhir, fe (hz), dan lama eksitasi atau waktu swept, tr (s). generator swept menghasilkan keluaran berupa fungsi swept, f(tk ). fungsi swept merupakan fungsi pengontrol frekuensi sinyal swept-sine. fungsi swept pada iterasi yang pertama adalah fungsi linear swept seperti pada gambar 3. fungsi ini dinotasikan dengan flin (tk ) (hz). fungsi flin (tk ) memiliki dua buah kondisi batas, yaitu: flin (0) = f0 dan flin (tr ) = fe . fungsi swept dengan flin (tk ) diekspresikan dengan: 𝑓𝑓(𝑡𝑡𝑘𝑘 ) = 𝑓𝑓𝑙𝑙𝑙𝑙𝑛𝑛 (𝑡𝑡𝑘𝑘 ) = (𝑓𝑓𝑡𝑡 − 𝑓𝑓0 ) � 𝑡𝑡𝑘𝑘 𝑇𝑇𝑟𝑟 � + 𝑓𝑓0 ; 0 ≤ 𝑡𝑡𝑘𝑘 ≤ 𝑇𝑇𝑟𝑟 (5) fungsi swept pada iterasi ke-2 dan berikutnya hingga diperoleh harga (𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 )/𝜀𝜀0 ) ≤ 1 adalah fungsi s535 swept yang dinotasikan dengan f535 (tk )(hz). fungsi ini disusun oleh tiga buah gambar 2. model simulasi pengukuran frf dengan eksitasi swept sine secara iteratif. gambar 3. fungsi flin (tk )dengan dua buah kondisi batas. a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 60 fungsi swept seperti yang ditunjukkan oleh gambar 4 dan diekspresikan dengan: 𝑓𝑓(𝑡𝑡𝑘𝑘 ) = 𝑓𝑓535 (𝑡𝑡𝑘𝑘 ) = � 𝑓𝑓𝑝𝑝𝑝𝑝 (𝑡𝑡𝑘𝑘 ); 0 ≤ 𝑡𝑡𝑘𝑘 < 𝑇𝑇𝑝𝑝 𝑓𝑓𝑐𝑐𝑐𝑐 (𝑡𝑡𝑘𝑘 ); 𝑇𝑇𝑝𝑝 ≤ 𝑡𝑡𝑘𝑘 < (𝑇𝑇𝑝𝑝 +𝑇𝑇𝑐𝑐 ) 𝑓𝑓𝑝𝑝𝑐𝑐 (𝑡𝑡𝑘𝑘 ); (𝑇𝑇𝑝𝑝 +𝑇𝑇𝑐𝑐) ≤ 𝑡𝑡𝑘𝑘 ≤ 𝑇𝑇𝑟𝑟 � (6) fungsi-fungsi swept yang menyusun f535 (tk ) adalah sebagai berikut: 1. fungsi fpa (tk )(hz) dengan enam buah kondisi batas, yaitu: 𝑓𝑓𝑝𝑝𝑝𝑝 (0) = 𝑓𝑓0 �̇�𝑓𝑝𝑝𝑝𝑝 (0) = 0 𝑓𝑓𝑝𝑝𝑝𝑝 � 𝑇𝑇𝑝𝑝 2 � = 𝑓𝑓1 = 𝑓𝑓0 + (𝑓𝑓𝑝𝑝 − 𝑓𝑓0 ) 4 �̇�𝑓𝑝𝑝𝑝𝑝 � 𝑇𝑇𝑝𝑝 2 � = (𝑓𝑓𝑝𝑝 − 𝑓𝑓0 ) 𝑇𝑇𝑝𝑝 𝑓𝑓𝑝𝑝𝑝𝑝 (𝑇𝑇𝑝𝑝 ) = 𝑓𝑓𝑝𝑝 �̇�𝑓𝑝𝑝𝑝𝑝 (𝑇𝑇𝑝𝑝 ) = 2 (𝑓𝑓𝑐𝑐 − 𝑓𝑓𝑝𝑝 ) 𝑇𝑇𝑐𝑐 fungsi fpa (tk ) adalah fungsi swept untuk frekuensi eksitasi swept-sine di bawah daerah frekuensi resonansi sistem. 𝑓𝑓𝑝𝑝𝑝𝑝 (𝑡𝑡𝑘𝑘 ) = ��𝑓𝑓𝑝𝑝 − 𝑓𝑓0��−8 � 𝑡𝑡𝑘𝑘 𝑇𝑇𝑝𝑝 � 3 + 16𝑡𝑡𝑘𝑘𝑇𝑇𝑝𝑝2−10𝑡𝑡𝑘𝑘𝑇𝑇𝑝𝑝+3+2𝑓𝑓𝑐𝑐−𝑓𝑓𝑝𝑝𝑇𝑇𝑝𝑝𝑇𝑇𝑐𝑐4𝑡𝑡𝑘𝑘 𝑇𝑇𝑝𝑝3−8𝑡𝑡𝑘𝑘𝑇𝑇𝑝𝑝2+5𝑡𝑡𝑘𝑘𝑇𝑇𝑝𝑝−1𝑡𝑡𝑘𝑘𝑇𝑇𝑝𝑝2+𝑓𝑓0 (7) 2. fungsi fcb (tk ) (hz) dengan empat kondisi batas, yaitu: 𝑓𝑓𝑐𝑐𝑐𝑐 (𝑇𝑇𝑝𝑝 ) = 𝑓𝑓𝑝𝑝 �̇�𝑓𝑐𝑐𝑐𝑐 (𝑇𝑇𝑝𝑝 ) = 2 (𝑓𝑓𝑐𝑐 − 𝑓𝑓𝑝𝑝 ) 𝑇𝑇𝑐𝑐 𝑓𝑓𝑐𝑐𝑐𝑐 (𝑇𝑇𝑝𝑝+𝑐𝑐 ) = 𝑓𝑓𝑐𝑐 ; 𝑇𝑇𝑝𝑝+𝑐𝑐 = 𝑇𝑇𝑝𝑝 + 𝑇𝑇𝑐𝑐 �̇�𝑓𝑐𝑐𝑐𝑐 (𝑇𝑇𝑝𝑝 + 𝑇𝑇𝑐𝑐 ) = 2 (𝑓𝑓𝑐𝑐 − 𝑓𝑓𝑝𝑝 ) 𝑇𝑇𝑐𝑐 fungsi fcb (tk ) adalah fungsi swept untuk frekuensi eksitasi swept-sine di sekitar frekuensi resonansi sistem. 𝑓𝑓𝑐𝑐𝑐𝑐 (𝑡𝑡𝑘𝑘 ) = �𝑓𝑓𝑐𝑐 − 𝑓𝑓𝑝𝑝��2 � 𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝 𝑇𝑇𝑐𝑐 � 2 − 3𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝𝑇𝑇𝑐𝑐+2𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝𝑇𝑇𝑐𝑐+𝑓𝑓𝑝𝑝 (8) 3. fungsi fpc (tk )(hz) dengan enam buah kondisi batas, yaitu: 𝑓𝑓𝑝𝑝𝑐𝑐 (𝑇𝑇𝑝𝑝+𝑐𝑐 ) = 𝑓𝑓𝑐𝑐 �̇�𝑓𝑝𝑝𝑐𝑐 (𝑇𝑇𝑝𝑝+𝑐𝑐 ) = 2 (𝑓𝑓𝑐𝑐 − 𝑓𝑓𝑝𝑝 ) 𝑇𝑇𝑐𝑐 𝑓𝑓𝑝𝑝𝑐𝑐 �𝑇𝑇𝑡𝑡 − 𝑇𝑇𝑐𝑐 2 � = 𝑓𝑓2 = 𝑓𝑓𝑡𝑡 − (𝑓𝑓𝑡𝑡 − 𝑓𝑓𝑐𝑐 ) 4 �̇�𝑓𝑝𝑝𝑐𝑐 �𝑇𝑇𝑡𝑡 − 𝑇𝑇𝑐𝑐 2 � = (𝑓𝑓𝑡𝑡 − 𝑓𝑓𝑐𝑐 ) 𝑇𝑇𝑐𝑐 𝑓𝑓𝑝𝑝𝑐𝑐 (𝑇𝑇𝑡𝑡 ) = 𝑓𝑓𝑡𝑡 �̇�𝑓𝑝𝑝𝑐𝑐 (𝑇𝑇𝑡𝑡 ) = 0. fungsi fpd (tk ) adalah fungsi swept untuk frekuensi eksitasi swept-sine di atas daerah frekuensi resonansi sistem. 𝑓𝑓𝑝𝑝𝑐𝑐 (𝑡𝑡𝑘𝑘 ) = ��𝑓𝑓𝑡𝑡 − 𝑓𝑓𝑐𝑐��−8 � 𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐 𝑇𝑇𝑐𝑐 � 4 + 24𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐3−26𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐2+11𝑡𝑡𝑘𝑘 −𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐+2𝑓𝑓𝑐𝑐−𝑓𝑓𝑝𝑝𝑇𝑇𝑐𝑐𝑇𝑇𝑐𝑐4𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐4− 12𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐3+13𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐2−6𝑡𝑡𝑘𝑘− 𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐+1𝑡𝑡𝑘𝑘−𝑇𝑇𝑝𝑝+𝑐𝑐𝑇𝑇𝑐𝑐+𝑓𝑓𝑐𝑐 (9) swept rate rata-rata dari fungsi f(tk ) yang dinotasikan dengan r̅f (hz/s) adalah �̅�𝑟𝑓𝑓 = 𝑓𝑓𝑡𝑡−𝑓𝑓0 𝑇𝑇𝑟𝑟 (10) dan interval waktu, ∆t(s), antara dua buah data f(tk ) bergantung kepada laju pencuplikan data, sr(sample/s), pada perangkat pengakuisisi data (daq device). ∆𝑡𝑡 = 1 𝑆𝑆𝑟𝑟 (11) gambar 4. fungsi f535 (tk ) dengan tiga fungsi swept penyusunnya. a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 61 b. eksitasi swept-sine fungs if(tk ) diproses oleh generator angular sehingga diperoleh angular, φ(tk ) (rad). fungsi φ(tk ) di ekspresikan dengan 𝜑𝜑(𝑡𝑡𝑘𝑘 ) = 2𝜋𝜋 ∫ [𝑓𝑓(𝑡𝑡)]𝑑𝑑𝑡𝑡 𝑡𝑡𝑘𝑘 0 ; 0 ≤ 𝑡𝑡𝑘𝑘 ≤ 𝑇𝑇𝑟𝑟 (12) selanjutnya eksitasi swept-sine dihasilkan oleh generator sinyal swept-sine dengan φ(tk ) dan amplitudo referensi, u0 (n), sebagai masukan. fungsi eksitasi swept-sine, u(tk ) (n), diekspresikan dengan 𝑢𝑢(𝑡𝑡𝑘𝑘 ) = 𝑈𝑈0 𝑠𝑠𝑙𝑙𝑛𝑛[𝜑𝜑(𝑡𝑡𝑘𝑘 )] ; 0 ≤ 𝑡𝑡𝑘𝑘 ≤ 𝑇𝑇𝑟𝑟 (13) c. respon sistem model hubungan u(tk ) dengan respon sistem, y (tk ) m, ditunjukkan oleh diagram blok pada gambar 5. pada gambar 5, fungsi yang menghubungkan u(t) dengan y(t) yang dinotasikan dengan h(t) merupakan fri (fungsi respon impuls) dari sistem 1-dk. diagram blok dari fri ini dapat dilihat pada gambar 6 [16]. keadaan dan persamaan keluaran sistem pada gambar 6 dengan metode ruang-keadaan (statespace) masing-masing diekspresikan dengan persamaan (14) dan (15) [17]. � �̇�𝑥1 �̇�𝑥2 � = � 0 1 − 𝑘𝑘𝑠𝑠 𝑚𝑚𝑠𝑠 − 𝑐𝑐 𝑚𝑚𝑠𝑠 �� 𝑥𝑥1 𝑥𝑥2 � + � 0 1 𝑚𝑚𝑠𝑠 �𝑢𝑢 {�̇�𝑥} = [𝐴𝐴]{𝑥𝑥} + {𝐵𝐵}𝑢𝑢 (14) 𝑦𝑦 = [1 0] � 𝑥𝑥1 𝑥𝑥2 � 𝑦𝑦 = [𝐶𝐶]{𝑥𝑥} (15) dimana {x} , y , u , [a] , {b} , dan [c] secara berturut-turut adalah vektor keadaan, vektor keluaran, vektor masukan, matriks keadaan, matriks masukan, dan matriks keluaran. diskritisasi persamaan (14) dan (15) meyajikan keadaan dan persamaan keluaran sistem dalam waktu diskrit secara berturut-turut dengan persamaan (16) dan (17) [16]. � 𝑥𝑥1�(𝑘𝑘 + 1)∆𝑡𝑡� 𝑥𝑥2�(𝑘𝑘 + 1)∆𝑡𝑡� � = [𝐺𝐺] � 𝑥𝑥1 (𝑘𝑘∆𝑡𝑡) 𝑥𝑥2 (𝑘𝑘∆𝑡𝑡) � + {𝐻𝐻}𝑢𝑢(𝑘𝑘∆𝑡𝑡) (16) 𝑦𝑦(𝑘𝑘∆𝑡𝑡) = [𝐶𝐶] � 𝑥𝑥1 (𝑘𝑘∆𝑡𝑡) 𝑥𝑥2 (𝑘𝑘∆𝑡𝑡) � (17) dimana, k = 0, 1, 2, … 𝐺𝐺 = 𝐿𝐿−1 ���𝑠𝑠 0 0 𝑠𝑠 � − [𝐴𝐴]� −1 � 𝐻𝐻 = �� 𝑡𝑡[𝐴𝐴]𝑡𝑡𝑑𝑑𝑡𝑡 ∆𝑡𝑡 0 � {𝐵𝐵} dengan s adalah variabel kompleks. matriks [g] dan {h} pada persamaan (16) adalah adalah matriks keadaan dan matriks masukan waktu diskrit yang secara berturut-turut dinyatakan dengan persamaan (18) dan (19). 𝐺𝐺 = 𝑡𝑡 −𝑝𝑝∆𝑡𝑡−𝑡𝑡−𝑐𝑐∆𝑡𝑡 𝑐𝑐−𝑝𝑝 � 2𝜁𝜁𝜔𝜔𝑛𝑛 − 𝐸𝐸 1 −𝜔𝜔𝑛𝑛2 −𝐸𝐸 � (18) 𝐻𝐻 = 1 𝑚𝑚𝑠𝑠(𝑐𝑐−𝑝𝑝) � − 1 𝑝𝑝 (𝑡𝑡−𝑝𝑝𝑎𝑎𝑡𝑡 − 1) + 1 𝑐𝑐 (𝑡𝑡−𝑐𝑐𝑎𝑎𝑡𝑡 − 1) 𝑡𝑡−𝑝𝑝𝑎𝑎𝑡𝑡 − 𝑡𝑡−𝑐𝑐𝑎𝑎𝑡𝑡 � (19) dimana, 𝐸𝐸 = 𝑝𝑝𝑡𝑡−𝑝𝑝𝑎𝑎𝑡𝑡 − 𝑐𝑐𝑡𝑡−𝑐𝑐𝑎𝑎𝑡𝑡 𝑡𝑡−𝑝𝑝𝑎𝑎𝑡𝑡 − 𝑡𝑡−𝑐𝑐𝑎𝑎𝑡𝑡 𝑝𝑝 = 𝜁𝜁𝜔𝜔𝑛𝑛 + 𝑙𝑙𝜔𝜔𝑛𝑛�1 − 𝜁𝜁2 𝑐𝑐 = 𝜁𝜁𝜔𝜔𝑛𝑛 − 𝑙𝑙𝜔𝜔𝑛𝑛�1 − 𝜁𝜁2 𝜔𝜔𝑛𝑛 = 2𝜋𝜋𝑓𝑓𝑛𝑛 dengan {x} pada kondisi awal adalah � 𝑥𝑥1 (0) 𝑥𝑥2 (0) � = �0 0 � dan c = [1 0], keadaan {x(tk )} dan persamaan keluaran y(tk ) diperoleh dengan � 𝑥𝑥1 (𝑡𝑡𝑘𝑘+1 ) 𝑥𝑥2 (𝑡𝑡𝑘𝑘+1 ) � = [𝐺𝐺] � 𝑥𝑥1 (𝑡𝑡𝑘𝑘 ) 𝑥𝑥2 (𝑡𝑡𝑘𝑘 ) � + {𝐻𝐻}𝑢𝑢(𝑡𝑡𝑘𝑘 ) (20) 𝑦𝑦(𝑡𝑡𝑘𝑘 ) = 𝑥𝑥1 (𝑡𝑡𝑘𝑘 ) ; 0 ≤ 𝑡𝑡𝑘𝑘 ≤ 𝑇𝑇𝑟𝑟 (21) d. frf sistem data pengukuran terhadap u(tk ) dan y(tk ) merupakan data-data diskrit dalam domain waktu. dengan mentransformasinya ke dalam domain frekuensi, kandungan frekuensi dari u(tk ) dan gambar 5. model hubungan antara u(tk ) dengan y(tk ). gambar 6. diagram blok fri (fungsi respon impuls) sistem-1dk. a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 62 y(tk ) dapat diketahui. transformasi data-data diskrit dalam domain waktu menjadi domain frekuensi dilakukan dengan menggunakan transformasi fourier diskrit (discrete fourier transform atau dft) [18]. dft terhadap u(tk ) dan y(tk ) menghasilkan koefisien dum dan dym secara berturut-turut pada persamaan (22) dan (23). 𝐷𝐷𝑢𝑢𝑚𝑚 = 1 𝑁𝑁 ∑ 𝑥𝑥(𝑡𝑡𝑘𝑘 )𝑡𝑡 −𝑙𝑙2𝜋𝜋 𝑚𝑚𝑠𝑠𝑘𝑘𝑠𝑠 𝑁𝑁𝑁𝑁−1𝑘𝑘=0 (22) 𝐷𝐷𝑦𝑦𝑚𝑚 = 1 𝑁𝑁 ∑ 𝑦𝑦(𝑡𝑡𝑘𝑘 )𝑡𝑡 −𝑙𝑙2𝜋𝜋 𝑚𝑚𝑠𝑠𝑘𝑘𝑠𝑠 𝑁𝑁𝑁𝑁−1𝑘𝑘=0 (23) dimana m= 0, 1, 2, … , n-1 dan n adalah jumlah d atau (tk ) atau y(tk ). koefisien dum dan dym berada pada domain frekuensi fm yang diperoleh dengan 𝑓𝑓𝑚𝑚 = 𝑚𝑚 𝑇𝑇𝑟𝑟 ; m = 0, 1, 2, ..., n-1 (24) spektrum frekuensi dari u(tk ) yang dinotasikan dengan u(fm ) dan spektrum frekuensi dari y(tk ) yang dinotasikan dengan y(fm ) diekspresikan dengan 𝑈𝑈(𝑓𝑓𝑚𝑚 ) = 𝐷𝐷𝑢𝑢𝑚𝑚 (25) 𝑌𝑌(𝑓𝑓𝑚𝑚 ) = 𝐷𝐷𝑦𝑦𝑚𝑚 (26) frf sistem dengan eksitasi swept-sine adalah rasio y(fm ) terhadap u(fm ). frf yang diperoleh pada pengukuran frf dengan eksitasi swept-sine disebut dengan frf swept-sine, hss (fm ), yang diekspresikan dengan 𝐻𝐻𝑆𝑆𝑆𝑆 (𝑓𝑓𝑚𝑚 ) = 𝑌𝑌(𝑓𝑓𝑚𝑚 ) 𝑈𝑈(𝑓𝑓𝑚𝑚 ) (27) magnitudo frf swept-sine, |hss( fm )| (m/n), diperoleh dengan |𝐻𝐻𝑆𝑆𝑆𝑆(𝑓𝑓𝑚𝑚 )| = �{𝑅𝑅𝑡𝑡[𝐻𝐻𝑆𝑆𝑆𝑆 (𝑓𝑓𝑚𝑚 )]}2 + {𝐼𝐼𝑚𝑚[𝐻𝐻𝑆𝑆𝑆𝑆(𝑓𝑓𝑚𝑚 )]}2 (28) dimana re[hss( fm )] dan im[hss( fm )] masingmasing adalah bagian real dan imaginer dari hss(fm ). e. data-data simulasi simulasi pengontrolan eksitasi swept sine terhadap sistem 1-dk dilakukan secara numerik dengan data-data masukan simulasi pada tabel 1. penentuan posisi dua titik pertemuan antara dua fungsi swept yaitu titik p(ta, fa) dan titik q(ta+tb, fb) pada fungsi f535 (tk ) ditentukan secara iteratif. harga ta divariasikan dari 0,05tr hingga 0,20tr dengan kenaikan 0,05tr, harga tb divariasikan dari 0,60tr sampai 0,95tr-ta dengan kenaikan 0,05tr, harga fa divariasikan dari 0,80fr hingga 0,95fr dengan kenaikan 0,05fr, dan harga fb divariasikan dari 1,05fr hingga 1,20fr dengan kenaikan 0,05fr. iii. hasil dan pembahasan kurva |hteo(f)| yang diperoleh dari simulasi ditunjukkan oleh gambar 7. dari kurva |hteo(f)| diperoleh frekuensi resonansi teoritik, fr = 24 hz, dengan harga |hteo(fr)| = 3,664x10-3 m/n. linear swept dan s535 swept yang diperoleh melalui simulasi secara iteratif ditunjukkan pada gambar 8. swept rate dari linear swept adalah 10 hz/s. harga swept rate ini digunakan kembali oleh s535 swept menjadi swept rate rata-rata. parameter s535 swept selain f0, fe, dan tr yang diperoleh secara iteratif untuk menghasilkan |hss(fr)| dengan (𝜀𝜀𝛼𝛼 (𝑓𝑓𝑟𝑟 )/𝜀𝜀0) ≤ 1 dapat dilihat pada tabel 2. gambar 7. kurva |hteo(f)| yang diperoleh dari simulasi. gambar 8. fungsi linear swept dan s535 swept yang diperoleh melalui simulasi secara iteratif. tabel 1 data-data masukan simulasi. parameter harga (satuan) massa, ms 1 (kg) peredam, c 1,81(ns/m) kekakuan, ks 22.739,57(n/m) kesalahan magnitudo referensi, ε0 5 (%) frekuensi awal, f0 0 (hz) frekuensi akhir, fe 40 (hz) lama eksitasi, tr 4 (s) amplitudo referensi, u0 1 (n) laju pencuplikan, sr 1600 (sample/s) a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 63 perbandingan eksitasi linear swept-sine,ulin(t), dengan eksitasi s535 swept-sine, u535(t), ditunjukkan oleh gambar 9(a). kandungan frekuensi eksitasi s535 swept-sine di sekitar frekuensi resonansi sistem memiliki alokasi waktu yang lebih lama jika dibandingkan dengan eksitasi linear swept-sine sebagaimana yang ditunjukkan oleh gambar 8. eksitasi s535 sweptsinedi sekitar frekuensi resonansi memiliki swept rate yang lambat atau berlangsung lebih lama sehingga menghasilkan respon sistem maksimum dengan amplitudo 14,670x10-4 m. sedangkan respon sistem maksimum terhadap eksitasi linear swept-sine mempunyai amplitudo sebesar 9,997x10-4 m sebagaimana yang ditunjukkan gambar 9(b). selain itu, dengan eksitasi s535 swept-sine, pengaruh respon transient di sekitar frekuensi resonansi hanya sedikit dan didominasi oleh respon steady-state. respon steady-state ini sangat mempengaruhi frf sistem karena frf merupakan fungsi perbesaran respon steady-state pada setiap frekuensi eksitasi [19]. kurva |hlin(f)| dan|h535(f)| yang masingmasing dihasilkan pada simulasi pengukuran frf sistem 1-dk dengan ekitasi linear swept-sine dan s535 swept-sine memperlihatkan frekuensi resonansi sistem yang tetap sama dengan harga teoritiknya yaitu fr = 24 hz. harga |hlin(f)| dan |h535(f)|di fr menunjukkan perbedaan yang signifikan dimana harga kesalahan |hlin(fr)| terhadap |hteo(fr)| lebih besar jika dibandingkan dengan harga kesalahan |h535(fr)| terhadap |hteo(fr)|. harga kesalahan |hlin(fr)| dan |h535(fr)| terhadap |hteo(fr)| dapat dilihat pada tabel 3. dengan demikian, pengontrolan kembali eksitasi swept-sine dengan sinyal s535 swept-sine mampu meminimalisasi kesalahan magnitudo frf yang diperoleh dari pengontrolan eksitasi swept-sine yang sebelumnya dengan sinyal linear swept-sine. selain itu, batas kesalahan magnitudo referensi sebesar 5% yang diinginkan dapat terpenuhi dengan pengontrolan eksitasi sweptsine dengan sinyal s535 swept-sine. gambar 9. gaya eksitasi swept-sine dan respon sistem; (a) perbandingan gaya eksitasi ulin(t) dengan u535(t); (b) perbandingan respon ylin(t) dengan y535(t). tabel 2 parameter s535 swept selain f0, fe, dan tr yang diperoleh secara iteratif. parameter harga (satuan) frekuensi di bawah fr, fa 22,8 (hz) frekuensi di atas fr, fb 28,8 (hz) waktu saat f = fa, ta 0,4 (s) waktu saat f = fb, tb 2,4 (s) tabel 3 perbedaan harga |hlin(f)| dan|h535(f)| terhadap |hteo(f)| di fr. |h(f)| |h(fr)|(m/n) εα(fr) (%) |hteo(f)| 3,664x10 -3 |hlin(f)| 2,900x10 -3 20,86 |h535(f)| 3,546x10 -3 3,22 gambar 10. perbandingan hlin(f)| dan|h535(f)| terhadap |hteo(f)|. a. yanto and z. abidin / mechatronics, electrical power, and vehicular technology 03 (2012) 57-64 64 iv. kesimpulan pengukuran frf sistem 1-dk dengan ms=1 kg, c = 1,81 ns/m, dan ks = 22.739,57 n/m secara simulasi dengan mengontrol eksitasi swept-sine yang diterapkan ke sistem dengan sinyal linear swept-sine menghasilkan kesalahan magnitude frf di fr sebesar 20,86 % untuk span frekuensi dari f0 = 0 hz sampai fe = 40 hz dan waktu swept tr = 4 s. kesalahan ini dapat diminimalisasi sehingga menjadi 3,22% dengan mengontrol kembali eksitasi swept-sine dengan menggunakan sinyal s535 swept-sine meskipun dengan span frekuensi dan waktu swept yang sama pada sinyal linear swept-sine. berdasarkan hasil simulasi pengontrolan eksitasi swept-sine pada makalah ini, sinyal s535 swept-sine dapat diusulkan sebagai sinyal untuk mengontrol eksitasi swept-sine pada pengukuran frf sistem nyata secara eksperimental. referensi [1] m. a. peres, et al., "practical aspects of shaker measurements for modal testing," in proc. of isma 2010, 2010, pp. 2539-2551. [2] d. cloutier, et al., "shaker/stringer effect on measured frequency response functions," presented at the 27th international modal analysis conference, orlando, florida, 2009. [3] u. füllekrug, et al., "measurement of frfs and modal identification in case of correlated multi-point excitation," shock and vibration, vol. 15, pp. 435-445, 2008. [4] k. g. mcconnell, vibration testing: theory and practice. new york: john wiley & sons inc., 1995. [5] n. haritos, "swept sine wave testing of compliant bottom-pivoted cylinders," in proceedings of the first (1991) international offshore and polar engineering conference edinburgh, united kingdom, 1991. [6] j. zhuge, advanced dynamic signal analysis. santa clara: crystal instruments corporation, 2009. [7] p. giclais, et al., "new excitation signals for aircraft ground vibration testing," presented at the international forum on aeroelasticity and structural dynamics 2011, munich, 2011. [8] k. napolitano and d. linehan, "multiple sine sweep excitation for ground test," presented at the 27th international modal analysis conference, orlando, florida, 2009. [9] b. peeters, et al., "modern solutions for ground vibration testing of large aircraft," presented at the 26th international modal analysis conference, orlando, florida, 2008. [10] s. orlando, et al., "improved frf estimators for mimo sine sweep data," in proceedings of the isma 2008 international conference on noise and vibration engineering, katholieke universiteit, leuven, 2008, pp. 229-241. [11] h. climent, "aeroelastic and structural dynamics tests at eads casa," in proc. of the 18th annual symposium of the society of flight test engineers sfte, madrid, 2007. [12] d. göge, et al., "ground vibration testing of large aircraft – state-of-the-art and future perspectives," presented at the 25th international modal analysis conference, orlando, florida, 2007. [13] s. pauwels, et al., "a new mimo sine testing technique for accelerated, high quality frf measurements," presented at the 24th international modal analysis conference, st. louis, mo, 2006. [14] g. gloth and m. sinapsis, "analysis of swept-sine runs during modal identification," mechanical systems and signal processing, vol. 18, pp. 1421–1441, 2004. [15] m. sinapius and g. gloth, "influence and characterisation of weak non-linearities in swept-sine modal testing," aerospace science and technology, vol. 8, pp. 111-120, 2004. [16] k. ogata, discrete-time control systems. new jersey: prentice-hall inc., 1995. [17] k. ogata, modern control engineering. new jersey: prentice-hall inc., 2002. [18] e. kreyszig, advanced engineering mathematics 9th edition, 9 ed. new york: john wiley & sons inc., 2006. [19] r. k. mobley, vibration fundamentals (plant engineering maintenance (hardback). boston: butterworth– heinemann, 1999. mev journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 www.mevjournal.com doi: https://dx.doi.org/10.14203/j.mev.2020.v11.64-74 2088-6985 / 2087-3379 ©2020 research centre for electrical power and mechatronics indonesian institute of sciences (rcepm lipi). this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is sinta 2 journal (https://sinta.ristekbrin.go.id/journals/detail?id=814) accredited by ministry of research & technology, republic indonesia. design and development of the semg-based exoskeleton strength enhancer for the legs mikecon cenit, vaibhav gandhi * department of design engineering and mathematics, middlesex university london the burroughs, hendon, london, nw4 4bt, united kingdom received 30 july 2019; accepted 11 may 2020; published online 22 december 2020 abstract this paper reviews the different exoskeleton designs and presents a working prototype of a surface electromyography (emg) controlled exoskeleton to enhance the strength of the lower leg. the computer aided design (cad) model of the exoskeleton is designed, 3d printed with respect to the golden ratio of human anthropometry, and tested structurally. the exoskeleton control system is designed on the labview national instrument platform and embedded in myrio. surface emg sensors (semg) and flex sensors are used coherently to create different state filters for the emg, human body posture and control for the mechanical exoskeleton actuation. the myrio is used to process semg signals and send control signals to the exoskeleton. thus, the complete exoskeleton system consists of semg as primary sensor and flex sensor as a secondary sensor while the whole control system is designed in labview. fea simulation and tests show that the exoskeleton is suitable for an average human weight of 62 kg plus excess force with different reactive spring forces. however, due to the mechanical properties of the exoskeleton actuator, it will require an additional lift to provide the rapid reactive impulse force needed to increase biomechanical movement such as squatting up. finally, with the increasing availability of such assistive devices on the market, the important aspect of ethical, social and legal issues have also emerged and discussed in this paper. ©2020 research centre for electrical power and mechatronics indonesian institute of sciences. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: leg-exoskeleton; electromyography based exoskeleton; labview myrio; ethical, societal, and legal concerns. i. introduction assisted exoskeleton technology seems to be still in the development stage, and needs to be improved to meet the individual needs [1]. some examples of this exoskeleton are berkeley lower extremity exoskeleton [2], raytheon xos2 [3], exosuit [4][5], darpa soft exosuit [6], ekso bionics [7] and many more [8]. these full body exoskeletons all have some limitation with their design, such as the lack of appropriate power supply suitable to their target specifications. specialised exoskeleton suits come in many varieties which are used as an aid for medical rehabilitation [9][10], industrial [11], military [12] and commercial [13]. these specialised exoskeletons allow individuals with any lower limb weakness including those who are paralyzed below to move and mimic the biomechanical movement of walking. any technology that can reduce casualties or enhance one’s survival in a harsh environment and open new strategical advantages will always find itself in military use. the concept of specialised exoskeletons is specific to one job but limits the energy consumption to a great extent. on the other hand, the whole body’s exoskeletons require a far greater power supply as the exoskeleton is needed to carry the weight of other parts of the suit that might not be used [14]. such technology may not be popular compared to a humanoid robot in the future, as it is specifically designed for medical and military use and is also expensive and far from generalizing for the general public. it is also impractical for daily life use as it is designed for a harsher environment than the civilian population or is made to help and strengthen one’s need for biomechanical movement. military concept exoskeleton is generally more developed according to the harsher environments [15]. potential commercial uses are also considered in this review for completeness [16]. a good example of exoskeleton suit that is used medically is the lifesuit prototype. a man called monty k. reed, broke his back due to a parachute accident, created a lifesuit i prototype in 1986 [17]. * corresponding author. tel: +44-2084115511 e-mail address: v.gandhi@mdx.ac.uk https://dx.doi.org/10.14203/j.mev.2020.v11.64-74 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 http://mevjournal.com/index.php/mev/index https://dx.doi.org/10.14203/j.mev.2020.v11.64-74 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2020.v11.64-74&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 65 his idea of a powered exoskeleton emerged when he was reading robert heinlein’s spaceship during his time in the hospital while recovering from his injuries. reed then demonstrated his findings at the university of washington engineering day event and had set a world record for the 8-inches high jump and a land-speed distance record for walking 5 km in powered exoskeletons in 90 minutes at saint patrick’s day dash 2005 [17]. the ls12 lifesuit prototype used to manage the record also caused some disadvatages to the pilot user. over time the material used to make the lifesuit had worn out and became loose, causing minor injuries to the pilot’s left outer thigh. the previous prototype also caused some minor injuries when the pilot conducted the experiments. however, the potential risk had been removed and improved with successors [18]. finding initial risks early within the project can be beneficial as the design can be improved. the lifesuit prototype exoskeleton framework became more ergonomic and more user-friendly as sophisticated systems are improved and added, for example, using the pneumatic power supply, pneumatic actuator and handheld controllers [18]. the handheld controller concept has pro and cons as the user’s hand is being mastered but this gives the pilot some manual control over the pneumatic actuators. mechanical robotic rehabilitation suits can be divided into the upper limb and lower limb usage [19]. exoskeletons for upper limb have a shared structure that mimics the human upper limb (figure 1 and figure 3). since the exoskeleton is attached to several upper limb locations difference in a human size, it makes it difficult for the robot to adapt [20]. the upper limb exoskeleton can also be arranged to help certain muscles during rehabilitation by regulating and algorithmic combination that adapts to the forces applied by the exoskeleton to the end user’s arm. most of the exoskeletons work around the biomechanical mechanism of the human flexion elbow movement and shoulder spherical movement [21]. on the other hand, some research on exoskeletons has also included the wrist movement and hand grasping movement [22][23]. some examples of the upper exoskeletons are armin 3 and intelliarm [24]. these exoskeletons have an integrated design 3-dof to help shoulder depression and elevation movements. the medarm’s exoskeleton has included depression, elevation, retraction and protraction actuator system, while other designs have utilized passive dof to support the ankle. passive dof helps the ankle to move and allows greater freedom of movement, and this minimizes the generated actuation force that is given at the joint [25][26][27]. lower limb exoskeletons (figure 2 and figure 4) focuses more on the ankle rehabilitation. the most common problems addressed in ankle rehabilitation studies is the gait pattern of the patient as the exoskeleton systems manipulate the applied force to improve the gait pattern of the end user [28]. the generalised design of robotic devices provides the actuated motion that affects the foot plantar flexion and figure 1. 9-dof of the human upper limb [72] figure 2. robotic gait trainer [73] m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 66 dorsiflexion. on the other hand, some devices include passive and/or controlled inversion and eversion movements. stiffness control of an actuator is commonly used rather than actuators that provide a massive amount of assistive force, but this is mainly due to the biomechanical movement of the ankle joint [29]. military categorised exoskeletons are more generalised to the entire human body (for example, raytheon xos clothing), unlike the medically categorised exoskeletons that are specific to certain key elements of the human body that focuses on say for example only the ankle and not the whole of the human body [30]. the raytheon sarcos’s xos2 robotic suit is roughly 50 % more energy efficient than the xos1 and weighs around 95 kg. the structure is built with high strength aluminium and steel alloy and utilizes actuators, controllers and sensors to perform the required task [31]. the exoskeleton can take a heavy object with a ratio of 17:1, and this is due to the high-pressure hydraulics used, but this again increases the overall weight of the exoskeleton itself. the system analyses the user’s limb movements and range awareness so it does not cause damage to itself. this prevents damage from unwanted movements such as sneezing and coughing. the motors have multiple speeds to overcome and produce the appropriate speed and power. although, xos2 is more energy efficient than its predecessor but it still has the limitation of the power source. the only power source provided to the system is through a wire tether that connect to the outside power supply. supplying it with an expensive on-board battery can be violated on the battlefield and can cause friendly casualty [32]. this paper proposes a low-cost and reasonably simple exoskeleton design with a focus on only assisting the user’s lower body. the paper is organized into six sections. section i introduces the exoskeleton designs in general. section ii provides a brief description of exoskeleton aspects, and especially surface emg (semg) control, which is used as a primary sensor in the proposed design. section iii details the proposed lower body one leg semg-controlled exoskeleton. section iv discusses the evaluation/testing of the proposed system. section v discusses the significant aspects of ethical, social and legal facets in new robotic technologies. section vi concludes the paper with a brief summary. ii. emg-based exoskeleton control there are several methods for moving and exoskeletons manoeuvring, however, the most sought-after concept is the use of electromyography (emg) [33][34][35]. emg signals can be classified into two types: intramuscular emg signals, detected from inside of the muscles; and surface emg signals (semgs), detected from the skin surface [36]. emgbased exoskeletons are usually designed with muscles that are easily accessible from the skin surface. for this reason, semg electrode circuit is used in this work. the semg-based system works by recording and processing the myoelectric signals from the user so that they can communicate and control the actuators. semg signals of flexor digitorum superficialis from the finger flexure and pollicis longus from the tumb flexure are commonly used as control (actuation) signals. among the muscles that are part of the upper/lower body limb exoskeleton [37][38], the muscle signals mentioned above are commonly used to create and control an exoskeleton or assistance robotic device that involves hand movements. this is due to the grasping movement, lower noise and the potential ergonomic value, as electrodes can be mounted on the forearm [39]. a better understanding of human anatomy, electrode placements, and the basic principles of muscle contraction can be found in peter konrad et al. research [40]. placement of the electrodes from the main voluntary muscles enables control to the specialized exoskeleton. usually using voluntary emg muscle signals that are partners with the right part of an exoskeleton creates far more natural movement with respect to the biomechanical movement of the human body. exoskeleton or auxiliary robots can also work without the correct paired muscle such as the case with amputated personnel [35]. different muscle types can be trained and used to mimic the emg signal required for natural movements. for example, a person without fingers can make a robot to capture an object by using the emg from different muscle group that does not interfere with other signals [39][41][42]. zaheer et al. [43] discuss the sensor site for ideal electrodes placement based on the results of the normalised motor unit and skin thickness. these concepts of the ideal electrode placement sites are located between the centre mass and the muscle figure 3. two rotation conventions for the glenohumeral joint model: (a) flexion–abduction–rotation and (b) azimuth– elevation–roll [29] figure 4. anklebot [28] m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 67 tendency area (figure 5 for a mapped area). the signal to noise ratio of the detected semg signal correlates with the motor unit yield. the signal to noise ratio is inversely related to the muscle fibres and thickness of the subdermal cell tissue between the sensor and muscles [43]. however, the concept of ideal electrode placement varies in different muscle groups [44] as well as from one subject to the other. inter-subject and intra-session variation is common knowledge in emg study [36][45]. subcutaneous fat has also been understood to inhibit semg signals [46][47], resulting in a lack of semg compared to the invasive emg needle method [48]. however, the location of this ideal sensor sites by f. zaheer et al. [43] is slightly different from the preferred sensor site of the kinesiology emg studies [49][50]. the general kinesiology emg studies are performed using stem electrodes with the intention of acquiring global muscle activities [50]. this study also confirms that reasonable motor unit results can be obtained from almost anywhere in the central mass of the selected muscle group. on the other hand, the results that muscles have localised regions that provide greater motor unit yields are likely related to variations in the emg signal resulting from the subdermal tissue throughout the muscle surface, and the quality of electrode contact of the sensor and the skin. this also shows evidence that correlates the direct relationship between the motor unit results and the signal to noise ratio of the emg signal. the poor sources of the semg signal are likely due to increasing distance between the electrode sensors and the muscle due to the subdermal tissue, which reduces the semg signal amplitude. however, based on some of the ideal electrode placement site results, the relationships of decreasing signal to noise ratio and increasing subdermal network seems inconsistent. therefore, some other factors may influence the motor unit results such as the muscle innervation zone. studies also show that the semg signal read in the skin area near the innervation zones produces signals with lower amplitude, resulting in a lower signal to noise ratio due to the cancellation of the action potentials moving in the opposite directions [42]. in summary, the semg signal near the muscle innervation seems to have higher frequencies and lower amplitudes. every area of the human body provides either adequate or poor emg signals that can vary from person to person. however, certain biomechanical movements of the muscles have preferred sites that provide richer motor unit results. they are generally located between the centre of the figure 5. electrode placement locations from the seven tested muscles topographically mapped by the normalized mu yield per sensor site with increasing circle sizes reflecting greater yields. average skinfold thickness is indicated by the hue of the color. the values for each muscle are as follows: (a) vastus lateralis: the normalized mu yield ranges from 0.3 0.9 and the skinfold ranges from 4 to 12.6 mm; (b) rectus femoris: the normalized mu yield ranges from 0.3 0.8 and the skinfold ranges from 5.9 to 12.4 mm; (c) tibialis anterior: the normalized mu yield ranges from 0.4 1 and the skinfold ranges from 3.3 to 6.7 mm; (d) hamstrings medial: the normalized mu yield ranges from 0.4 0.9 and the skinfold ranges from 7.8 11.5 mm; hamstrings lateral: the normalized mu yield ranges from 0.5 0.9 and the skinfold ranges from 6.4 to 12.5 mm; (e) gastrocnemius medial: the normalized mu yield ranges from 0.3 0.9 and the skinfold ranges from 6 to 12.6 mm, gastrocnemius lateral: the normalized mu yield ranges from 0.3 1 and the skinfold ranges from 6 to 12 mm; (f) soleus: the normalized mu yield ranges from 0.2 0.9 and the skinfold ranges from 5.4 – 9 mm; (g) biceps brachii medial: the normalized mu yield ranges from 0.7 1 and the skinfold ranges from 3.1 to 6.7 mm, biceps brachii lateral: the normalized mu yield ranges [43] m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 68 muscle mass when contracted and the tendinous area. another ideal electrode placement is in the area of the skin with the thinnest subdermal tissues. therefore, the electrodes placement will be located in the area as shown in figure 5 of vastus lateralis and rectus femoris. iii. proposed semg based exoskeleton a. overall design and software the development of exoskeleton size depends on anthropometry [51] i.e., the physical measure of human size. for the proposed design, the leg to body height ratio of 49 % with respect to the average male size of 175 cm is considered. the research also includes ±1, 2 or 3 mean value bases of the 49 % comparison to different racial origins. thus, the most appropriate exoskeleton size is based on the average human height. smaller exoskeletons can be made to adapt to the average size of the female. therefore, the size of the exoskeleton is made on the basis of 85.75 cm due to the 49 % of the male average of 175 cm. the proposed exoskeleton (figure 6 to figure 9) consists of flex sensors and actuators that are controlled by using the ni myrio (labview) [52] based control system (figure 10). the start-up sensors used is from the bitalino hardware and software tools kit [53]. bitalino hardware and software are specifically designed to read body signals such as electrocardiography (ecg), semg and many more; and has a configurable sampling rate of 1, 10, 100, and 1000 hz [54]. flex sensors are used in the development of the exoskeleton as a secondary controller while maintaining the bitalino semg sensor [55] as the primary sensor. the semg sensor cannot be removed and provides bipolar differential measurement. the raw semg signals should be filtered using appropriate techniques such as savitzsky-golay (sg) [56], or advanced techniques as recurrent quantum neural network [57][58] and many others [59][60][61]. in the current work, raw semg signals from the bitalino are sampled at 100 hz, filtered and refined using the sg convolution filter concept. flex sensors are installed at the top of the knee joint to read the user’s posture, create a condition for the control system software, and appear to provide information with a good level of precision, reliability and repeatability [62]. the default analogue value that is read then sent to a state condition that provides boolean control for the system. the state condition is calibrated to fit the user’s sensitivity preference over the exoskeleton, and provides the user’s posture state. depending on the posture, different numeric polynomial sequences and side points are provided for the sg filter labview program. memory shape materials can be used as actuators for exoskeleton systems because it does not require external or onboard functioning energy, thereby increasing energy efficiency [63][64]. there are numerous forms of memory materials that can be used, but for the proposed exoskeleton, a tension spring is used as it mimics kinetic movement properties of the pneumatic air muscle when contracting to support the user when squatting and storing the energy. the stored energy is subsequently used to support the user to squat up. a mechanical ratchet and pawl (designed in-house) (figure 6, figure 7) is used to hold down the extension of the tension spring from releasing the stored potential energy. figure 6. ratchet and pawl figure 7. fea simulation of ratchet gear m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 69 the cad design (figure 8) incorporates the rapid prototyping of a grey 3d printer. the ratchet turns as the user squats down and is held by the mechanical pawl. the design concept is to control the reactive force of a spring. the pawl is controlled using a servo motor. the position of the servo motor changes according to the user proclaimed by the system after user calibration. the exoskeleton structural framework is made using aluminium metal to stop potential electrical problems. the good advantage of using aluminium for developing the exoskeleton is due to the machinery available to be used and also the anti-rusting nature. the metals is cut using a water jet cutter that immerses the material in an aqueous environment. carbon fibre is planned as the final material to be used for commercial development of the exoskeleton. the red spring is installed in-between the aluminium frames to concentrate the spring strength and share the load between the frames (figure 8). the complex 3d parts that are manufactured using the 3d printer had weak tensile strength, therefore a material change is needed. improving the previous prototype design, the revised design incorporates layered sheet build due to the water jet cutting machine is only able to cut flat aluminium material. the 1060-h14 grade aluminium alloy is used as the main body material in the production of the exoskeleton as it is widely recognized for its excellent corrosion resistance, high durability and highly reflective blue/silver appearance (figure 9). the strap has been added to attach to the exoskeleton, and is locked and joined using velcro to allow different leg sizes. the yellow soft foam padding is added in a place where the exoskeleton will make surface contact with the user. this creates a soft feeling for the user instead of cold metal and also improve the ergonomic design. when the parameters set for the semg signal are triggered, a boolean output is given. the condition parameters are set to check the value provided by the flex sensor. the result is two boolean outputs telling the control system that the user’s posture must stand or sit on the base of the angle range of the knee. the boolean output results are sent to the state condition to control the servo position (figure 10). figure 8. cad prototype of the exoskeleton figure 9. physical prototype of the exoskeleton figure 10. ni labview control system model m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 70 iv. testing and evaluation a. structural test ratchet is the only mechanical part that holds the reactive force of the spring potential energy. the 1060-h14 aluminium alloy has a shear modulus of 2.63+010 n/m2. the force applied on finite element analysis (fea) simulation of the ratchet gear is set on 607.6 n. the average human weight is 62 kg = 607.6 n. to ensure the system can handle enough spring force to carry the weight of the average human body plus the excess force of overweight users. the fea simulation shows the highest 8.850e+007 von mises of the ratchet gear is way below the shear modulus of the 1060-h14 aluminium alloy (figure 7). b. semg signal based on different spring reactive force ‘no-load signal’ is the exoskeleton fitted on the user while adjusting the reaction force of the spring to eliminate the weight of the exoskeleton. this establishes the initial basis to show that the exoskeleton can compensate for its own weight without providing support value. both ’10 kg signal load’ and ’20 kg signal load’ are defined as additional reactive force with the additional negative reactive force required to nullify the weight of the exoskeleton (figure 11). to create a simple average of quadricep semg activity while squatting requires some categorization. 10 samples close to the specification and classification are used to create this average value of the semg signal shown in figure 12. the classification of data works by collecting the array of amplitude values from the start of the squat to the end of the squat in a certain amount of time and between breaks. the rest time between each repetition of squat is 4 seconds which is double the time of the 2 second full squat. once the classification of the data is done, each data set is layered on top of one another to find the most suitable one. based on the semg signal graph of ‘no-load signal’ shown on figure 12(a), it shows; four amplitude spikes: the first and second amplitude spike is located at 0 to 90 y-axes when the user is squatting down, as expected due to the quadriceps and hamstring muscle support the body to descend. once the user reached the target, squat down the legs muscle pass most of the load to the gluteus maximus as shown on the semg amplitude which drops at 90 to 105 y-axes. on the other hand, the third semg amplitude spike up is located at 105 to 132 y-axes, this is due to the user squatting up. the body requires a massive workload impact force to move the body weight against gravity. the muscle relaxes as it reaches its baseline point/standing, as shown at 140 to 200 y-axes. once the user stands up, the weight load is transferred parallel from the leg muscle on the bones to the foot. the comparison of the average semg signal with different reactive spring force shown in figure 12 shows; exoskeleton supports the user well as the strength of body weight pushes the legs down due to squatting. there is an overall lower average semg amplitude as the reactive force provided by the spring actuator increases. as the reactive force of the spring increases, the time needed for the user to squat down also increase as the downward force is damped by the spring. on the other hand, the squat up process time is reduced as the stored potential energy inside the spring helps the user to stand up. therefore, as the spring reactive force increases, the working time of a full squat increase in the process. the actuator memory form material has a good property of absorbing the body weight strength. in the first half of the semg signal, where the user squats down, the semg signal indicates a lower semg amplitude value as the spring reactive force increases. due to its mechanical properties, the memory shape actuator fails to provide a quick impulse reactive force required to increase the squatting biomechanical movement. an additional actuator is required to compensate for the additional reactive force to increase the squatting biomechanical movement. adding more shape memory foam to the system can provide a bigger reactive force impulse. however, the process flow chart would change to accommodate the biomechanical time and movement that needed to convert more kinetic force from squatting down to potential energy stored in the spring shape of the memory. figure 11. squat semg signal of the quadricep with different spring load x-axis [100 = 1 second] y-axis [100mv] m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 71 (a) (b) (c) figure 12. semg signal with varying load reactive forces (a) no load reactive force; (b) 10 kg reactive force; (c) 20 kg reactive force. x-axis [100 = 1 second], y-axis [100mv] m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 72 v. ethical, societal, and legal (els) aspects in wearable robotics according to salvini [65], in the coming years, the western societies will have population aged of 60 more than younger people and, to make things even worse, the family caregivers are no longer willing to look after their older relatives, thus obliging them to use wearable robots. this is where assistive devices such as the one discussed here can play an important role. however, with the increasing availability of such assistive devices, an important aspect of ethical, social, legal and standardization aspects have emerged [66][67][68][69]. a comprehensive and a very recent work on els issues in wearable robotics, identifying relevant values and ethical, philosophical, legal and social concerns related to the design, dissemination and practical use of wearable robots can be found in felzmann et al. work [69]. there are several other works in this field such as that by greenbaum et al. [70], which talks about the specifics related mainly to exoskeleton designs. greenbaum et al. also raises an important open question as a way of dealing with the high costs of exoskeletons in relation to social justice of access/affordability for all who need it (especially with the increasing ageing population), as well as the dependence on expensive technologies that eventually occurs. it seems that for the wider society, exoskeletons and other technological enhancement raise much longer and complex questions that will force human to redefine how human themselves are being perceived [70]. calo in [71] examines very well and probably for the first time what is the meaning of the introduction of equally transformative new technologies for cyberlaw and policies regarding integrating robotics and such new technologies. vi. conclusion the semg-based exoskeleton concept of using a spring as a mechanical actuator works well but it is limited to the energy a spring can store. the memory shape material actuator has a good property of absorbing the body weight force while supporting the user to squat down. on the other hand, the time a person takes to squat down increases as the downwards force is dampened by the spring, slowing down the full squatting action. the amplitude value of semg control signal does not have a repetitive arrangement value over time as the muscle contraction varies with minute changes across the environment and the user. in addition, the semg electrode placement varies from subject to subject. the entire area of the leg muscle provides semg signals that can be decomposed to produce the firing instances and shapes of several motor unit. however, muscles have preferred a place that provides richer motor unit yields. they are generally located between the centre of the abdominal muscle and the muscle tendon area. these sites are associated with regions where the easily measured skinfolds have the least thickness. therefore, the required amplitude control is set to a lower range to trigger the system to change the servo position. the squat down process shows the greatest change with the different semg signal and increased spring reactive force. however, minute changes occur with semg signal of squat up. on the other hand, the implantable surgical subdermal electrode implant may provide reliable data as it will no longer be interfered by the skin and the outer layer fat. there is room for further improvement in using the tension spring as a mechanical actuator such as, optimizing the ideal reactive force of the spring and increase the amount of either the tension spring or longer extension range of a spiral spring. the spring(s) can be charged up to the maximum after two or more squat down then releases the stored potential energy in one squat up. another improvement is to use various types of advanced actuators to create hybrid exoskeleton consisting of mechanical and pneumatic components. nevertheless, the proposed semg driven mechanical exoskeleton is proven to help users with squatting biomechanical movement, however, it will require further improvement. declarations author contribution m. cenit conceived the original idea. v. gandhi supervised and revised the work critically. both authors read and approved the final paper. funding statement this research was internally funded by the faculty of science and technology, middlesex university london, uk. conflict of interest the authors declare no conflict of interest. additional information no additional information is available for this paper. references [1] h. s. lo and s. q. xie, "exoskeleton robots for upper-limb rehabilitation: state of the art and future prospects," med. eng. phys., vol. 34, (3), pp. 261-268, 2012. [2] a. b. zoss, h. kazerooni and a. chu, "biomechanical design of the berkeley lower extremity exoskeleton (bleex)," ieee/asme transactions on mechatronics, vol. 11, (2), pp. 128138, 2006. [3] m. hanlon, "raytheon xos 2: second-generation exoskeleton. robotics suit, united states of america," gizmag: website: www.gizmag.com/raytheon-significantly-progressesexoskeletondesign/16479, 2015 [4] k. tsuneyasu, a. ohno, y. fukuda, k. ogawa, t. tsuji and y. kurita, "a soft exoskeleton suit to reduce muscle fatigue with pneumatic artificial muscles," in proceedings of the 9th augmented human international conference, 2018. [5] a. t. asbeck, r. j. dyer, a. f. larusson and c. j. walsh, "biologically-inspired soft exosuit," in 2013 ieee 13th international conference on rehabilitation robotics (icorr), 2013. [6] c. walsh, a. t. asbeck, i. g. bujanda, y. ding, r. j. dyer, a. f. larusson, b. t. quinlivan, k. schmidt, d. wagner and m. wehner, "soft exosuit for assistance with human motion," 2016. [7] l. brenner, "exploring the psychosocial impact of ekso bionics technology," arch. phys. med. rehabil., vol. 97, (10), pp. e113, 2016. [8] c. m. wilkins, "an experimental study of the human interface with one atmosphere diving suit by appendages," 2016. https://doi.org/10.1016/j.medengphy.2011.10.004 https://doi.org/10.1016/j.medengphy.2011.10.004 https://doi.org/10.1016/j.medengphy.2011.10.004 https://doi.org/10.1109/tmech.2006.871087 https://doi.org/10.1109/tmech.2006.871087 https://doi.org/10.1109/tmech.2006.871087 https://doi.org/10.1109/tmech.2006.871087 https://newatlas.com/raytheon-significantly-progresses-exoskeleton-design/16479/ https://newatlas.com/raytheon-significantly-progresses-exoskeleton-design/16479/ https://newatlas.com/raytheon-significantly-progresses-exoskeleton-design/16479/ https://newatlas.com/raytheon-significantly-progresses-exoskeleton-design/16479/ https://doi.org/10.1145/3174910.3174933 https://doi.org/10.1145/3174910.3174933 https://doi.org/10.1145/3174910.3174933 https://doi.org/10.1145/3174910.3174933 https://doi.org/10.1109/icorr.2013.6650455 https://doi.org/10.1109/icorr.2013.6650455 https://doi.org/10.1109/icorr.2013.6650455 https://doi.org/10.1109/icorr.2013.6650455 https://patents.google.com/patent/us9351900b2/en https://patents.google.com/patent/us9351900b2/en https://patents.google.com/patent/us9351900b2/en https://patents.google.com/patent/us9351900b2/en https://doi.org/10.1016/j.apmr.2016.08.353 https://doi.org/10.1016/j.apmr.2016.08.353 https://doi.org/10.1016/j.apmr.2016.08.353 https://dspace.mit.edu/handle/1721.1/104298 https://dspace.mit.edu/handle/1721.1/104298 m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 73 [9] a. s. gorgey, "robotic exoskeletons: the current pros and cons," world journal of orthopedics, vol. 9, (9), pp. 112, 2018. [10] m. mekki, a. d. delgado, a. fry, d. putrino and v. huang, "robotic rehabilitation and spinal cord injury: a narrative review," neurotherapeutics, vol. 15, (3), pp. 604-617, 2018. [11] m. fontana, r. vertechy, s. marcheschi, f. salsedo and m. bergamasco, "the body extender: a full-body exoskeleton for the transport and handling of heavy loads," ieee robotics & automation magazine, vol. 21, (4), pp. 34-44, 2014. [12] w. van diik, t. van de wijdeven, m. m. holscher, r. barents, r. könemann, f. krause and c. l. koerhuis, "exobuddy-a nonanthropomorphic quasi-passive exoskeleton for load carrying assistance," in 2018 7th ieee international conference on biomedical robotics and biomechatronics (biorob), 2018. [13] f. lunardini, c. casellato, a. d'avella, t. d. sanger and a. pedrocchi, "robustness and reliability of synergy-based myocontrol of a multiple degree of freedom robotic arm," ieee transactions on neural systems and rehabilitation engineering, vol. 24, (9), pp. 940-950, 2015. [14] r. bogue, "exoskeletons and robotic prosthetics: a review of recent developments," industrial robot: an international journal, 2009. [15] n. fotion and g. elfstrom, "military ethics: guidelines for peace and war," 1986. [16] m. vukobratovic et al, biped locomotion: dynamics, stability, control and application. springer science & business media, vol. 7, 2012. [17] m. k. reed, "lifesuit exoskeleton gives the gift of walking so they shall walk," in ieee global humanitarian technology conference (ghtc 2014), 2014. [18] c. kopp, "exoskeletons for warriors of the future," defence today, vol. 9, (2), pp. 38-40, 2011. [19] s. hesse, h. schmidt, c. werner and a. bardeleben, "upper and lower extremity robotic devices for rehabilitation and for studying motor control," curr. opin. neurol., vol. 16, (6), pp. 705-710, 2003. [20] k. bharadwaj, t. g. sugar, j. b. koeneman and e. j. koeneman, "design of a robotic gait trainer using spring over muscle actuators for ankle stroke rehabilitation," 2005. [21] c. t. freeman, e. rogers, a. hughes, j. h. burridge and k. l. meadmore, "iterative learning control in health care: electrical stimulation and robotic-assisted upper-limb stroke rehabilitation," ieee control syst. mag., vol. 32, (1), pp. 18-43, 2012. [22] l. lucas, m. dicicco and y. matsuoka, "an emg-controlled hand exoskeleton for natural pinching," journal of robotics and mechatronics, vol. 16, pp. 482-488, 2004. [23] m. krawczyk, z. yang, v. gandhi, m. karamanoglu, f. m. franca, l. priscila, w. xiaochen and t. geng, "wrist movement detector for ros based control of the robotic hand," advances in robotics and automation, vol. 7, (1), 2018. [24] t. nef, m. guidali and r. riener, "armin iii–arm therapy exoskeleton with an ergonomic shoulder actuation," applied bionics and biomechanics, vol. 6, (2), pp. 127-142, 2009. [25] a. h. stienen, e. e. hekman, van der helm, frans ct and h. van der kooij, "self-aligning exoskeleton axes through decoupling of joint rotations and translations," ieee transactions on robotics, vol. 25, (3), pp. 628-633, 2009. [26] y. ren, h. park and l. zhang, "developing a whole-arm exoskeleton robot with hand opening and closing mechanism for upper limb stroke rehabilitation," in 2009 ieee international conference on rehabilitation robotics, 2009. [27] c. carignan, j. tang and s. roderick, "development of an exoskeleton haptic interface for virtual task training," in 2009 ieee/rsj international conference on intelligent robots and systems, 2009. [28] a. roy, h. i. krebs, s. l. patterson, t. n. judkins, i. khanna, l. w. forrester, r. m. macko and n. hogan, "measurement of human ankle stiffness using the anklebot," in 2007 ieee 10th international conference on rehabilitation robotics, 2007. [29] j. lu, k. haninger, w. chen, s. gowda, m. tomizuka and j. m. carmena, "design of a passive upper limb exoskeleton for macaque monkeys," journal of dynamic systems, measurement, and control, vol. 138, (11), 2016. [30] s. oh, e. baek, s. song, s. mohammed, d. jeon and k. kong, "a generalized control framework of assistive controllers and its application to lower limb exoskeletons," robotics and autonomous systems, vol. 73, pp. 68-77, 2015. [31] j. zhu and h. zhou, "realization of key technology for intelligent exoskeleton load system," in advances in information technology and industry applications, 2012. [32] d. m. dao, p. d. pham, t. x. tran and t. t. t. le, "study on the transient response of lower limb rehabilitation actuator using the pneumatic cylinder," journal of mechatronics, electrical power, and vehicular technology, vol. 9, (2), pp. 65-72, 2018. [33] v. krasin, v. gandhi and z. yang, "emg based elbow joint powered exoskeleton for biceps brachii strength augmentation," in july 12-17, 2015. [34] r. m. singh, s. chatterji and a. kumar, "trends and challenges in emg based control scheme of exoskeleton robots-a review," int j sci eng res, vol. 3, (9), pp. 933-940, 2012. [35] l. j. myers, m. lowery, m. o'malley, c. l. vaughan, c. heneghan, a. s. c. gibson, y. harley and r. sreenivasan, "rectification and non-linear pre-processing of emg signals for cortico-muscular analysis," j. neurosci. methods, vol. 124, (2), pp. 157-165, 2003. [36] d. copaci, d. serrano, l. moreno and d. blanco, "a high-level control algorithm based on semg signalling for an elbow joint sma exoskeleton," sensors, vol. 18, (8), pp. 2522, 2018. [37] g. weddell, b. feinstein and r. e. pattle, "the electrical activity of voluntary muscle in man under normal and pathological conditions." brain: a journal of neurology, 1944. [38] d. denny-brown and j. b. pennybacker, "fibrillation and fasciculation in voluntary muscle," brain, vol. 61, (3), pp. 311312, 1938. [39] o. fukuda, t. tsuji, m. kaneko and a. otsuka, "a humanassisting manipulator teleoperated by emg signals and arm motions," ieee trans. rob. autom., vol. 19, (2), pp. 210-222, 2003. [40] p. konrad, "a practical introduction to kinesiological electromyography," the abc of emg, vol. 1, 2005. [41] c. j. de luca, a. adam, r. wotiz, l. d. gilmore and s. h. nawab, "decomposition of surface emg signals," j. neurophysiol., vol. 96, (3), pp. 1646-1657, 2006. [42] c. j. de luca, s. chang, s. h. roy, j. c. kline and s. h. nawab, "decomposition of surface emg signals from cyclic dynamic contractions," j. neurophysiol., vol. 113, (6), pp. 1941-1951, 2015. [43] f. zaheer, s. h. roy and c. j. de luca, "preferred sensor sites for surface emg signal decomposition," physiol. meas., vol. 33, (2), pp. 195, 2012. [44] n. u. ahamed, k. sundaraj, r. b. ahmad, m. rahman and m. a. islam, "analysis of right arm biceps brachii muscle activity with varying the electrode placement on three male age groups during isometric contractions using a wireless emg sensor," procedia engineering, vol. 41, pp. 61-67, 2012. [45] c. amma, t. krings, j. böer and t. schultz, "advancing musclecomputer interfaces with high-density electromyography," in proceedings of the 33rd annual acm conference on human factors in computing systems, 2015. [46] r. h. chowdhury, m. b. reaz, ali, mohd alauddin bin mohd, a. a. bakar, k. chellappan and t. g. chang, "surface electromyography signal processing and classification techniques," sensors, vol. 13, (9), pp. 12431-12466, 2013. [47] m. a. hemingway, h. biedermann and j. inglis, "electromyographic recordings of paraspinal muscles: variations related to subcutaneous tissue thickness," biofeedback self., vol. 20, (1), pp. 39-49, 1995. [48] m. r. al-mulla, f. sepulveda and m. colley, "a review of noninvasive techniques to detect and predict localised muscle fatigue," sensors, vol. 11, (4), pp. 3545-3594, 2011. [49] k. woÿniak, d. piątkowska, m. lipski and k. mehr, "surface electromyography in orthodontics–a literature review," medical science monitor: international medical journal of experimental and clinical research, vol. 19, pp. 416, 2013. [50] i. campanini, a. merlo, p. degola, r. merletti, g. vezzosi and d. farina, "effect of electrode location on emg signal envelope in leg muscles during gait," journal of electromyography and kinesiology, vol. 17, (4), pp. 515-526, 2007. [51] c. hansen, f. gosselin, k. b. mansour, p. devos and f. marin, "design-validation of a hand exoskeleton using musculoskeletal modeling," appl. ergon., vol. 68, pp. 283-288, 2018. [52] hardware integration with ni labview. available online 5th march 2019. [53] j. guerreiro, r. martins, h. silva, a. lourenço and a. l. fred, "bitalino-a multimodal platform for physiological computing," in icinco (1), 2013. [54] h. p. da silva, j. guerreiro, a. lourenço, a. l. fred and r. martins, "bitalino: a novel hardware framework for physiological computing." in phycs, 2014. [55] electromyography (emg) sensor data sheet. 2016. [56] a. savitzky and m. j. e. golay, "smoothing and differentiation of data by simplified least squares procedures," anal. chem., vol. 36, (8), pp. 1627-1639, 1964. [57] v. gandhi and t. m. mcginnity, "quantum neural network based surface emg signal filtering for control of robotic hand," https://doi.org/10.5312/wjo.v9.i9.112 https://doi.org/10.5312/wjo.v9.i9.112 https://doi.org/10.1007/s13311-018-0642-3 https://doi.org/10.1007/s13311-018-0642-3 https://doi.org/10.1007/s13311-018-0642-3 https://doi.org/10.1109/mra.2014.2360287 https://doi.org/10.1109/mra.2014.2360287 https://doi.org/10.1109/mra.2014.2360287 https://doi.org/10.1109/mra.2014.2360287 https://doi.org/10.1109/biorob.2018.8487794 https://doi.org/10.1109/biorob.2018.8487794 https://doi.org/10.1109/biorob.2018.8487794 https://doi.org/10.1109/biorob.2018.8487794 https://doi.org/10.1109/biorob.2018.8487794 https://doi.org/10.1109/tnsre.2015.2483375 https://doi.org/10.1109/tnsre.2015.2483375 https://doi.org/10.1109/tnsre.2015.2483375 https://doi.org/10.1109/tnsre.2015.2483375 https://doi.org/10.1109/tnsre.2015.2483375 https://doi.org/10.1108/01439910910980141 https://doi.org/10.1108/01439910910980141 https://doi.org/10.1108/01439910910980141 https://doi.org/10.1086/292991 https://doi.org/10.1086/292991 https://doi.org/10.1007/978-3-642-83006-8 https://doi.org/10.1007/978-3-642-83006-8 https://doi.org/10.1007/978-3-642-83006-8 https://doi.org/10.1109/ghtc.2014.6970309 https://doi.org/10.1109/ghtc.2014.6970309 https://doi.org/10.1109/ghtc.2014.6970309 http://www.ausairpower.net/pdf-a/dt-exoskeletons-sep-2011.pdf http://www.ausairpower.net/pdf-a/dt-exoskeletons-sep-2011.pdf https://doi.org/10.1097/00019052-200312000-00010 https://doi.org/10.1097/00019052-200312000-00010 https://doi.org/10.1097/00019052-200312000-00010 https://doi.org/10.1097/00019052-200312000-00010 https://doi.org/10.1115/1.2049333 https://doi.org/10.1115/1.2049333 https://doi.org/10.1115/1.2049333 https://doi.org/10.1109/mcs.2011.2173261 https://doi.org/10.1109/mcs.2011.2173261 https://doi.org/10.1109/mcs.2011.2173261 https://doi.org/10.1109/mcs.2011.2173261 https://doi.org/10.1109/mcs.2011.2173261 https://doi.org/10.20965/jrm.2004.p0482 https://doi.org/10.20965/jrm.2004.p0482 https://doi.org/10.20965/jrm.2004.p0482 https://doi.org/10.4172/2168-9695.1000182 https://doi.org/10.4172/2168-9695.1000182 https://doi.org/10.4172/2168-9695.1000182 https://doi.org/10.4172/2168-9695.1000182 https://doi.org/10.1080/11762320902840179 https://doi.org/10.1080/11762320902840179 https://doi.org/10.1080/11762320902840179 https://doi.org/10.1109/tro.2009.2019147 https://doi.org/10.1109/tro.2009.2019147 https://doi.org/10.1109/tro.2009.2019147 https://doi.org/10.1109/tro.2009.2019147 https://doi.org/10.1109/icorr.2009.5209482 https://doi.org/10.1109/icorr.2009.5209482 https://doi.org/10.1109/icorr.2009.5209482 https://doi.org/10.1109/icorr.2009.5209482 https://doi.org/10.1109/iros.2009.5354834 https://doi.org/10.1109/iros.2009.5354834 https://doi.org/10.1109/iros.2009.5354834 https://doi.org/10.1109/iros.2009.5354834 https://doi.org/10.1109/icorr.2007.4428450 https://doi.org/10.1109/icorr.2007.4428450 https://doi.org/10.1109/icorr.2007.4428450 https://doi.org/10.1109/icorr.2007.4428450 https://doi.org/10.1109/icra.2014.6907051 https://doi.org/10.1109/icra.2014.6907051 https://doi.org/10.1109/icra.2014.6907051 https://doi.org/10.1109/icra.2014.6907051 https://doi.org/10.1007/978-3-642-26001-8_11 https://doi.org/10.1007/978-3-642-26001-8_11 https://doi.org/10.1007/978-3-642-26001-8_11 https://doi.org/10.14203/j.mev.2018.v9.65-72 https://doi.org/10.14203/j.mev.2018.v9.65-72 https://doi.org/10.14203/j.mev.2018.v9.65-72 https://doi.org/10.14203/j.mev.2018.v9.65-72 https://doi.org/10.1109/ijcnn.2015.7280643 https://doi.org/10.1109/ijcnn.2015.7280643 https://doi.org/10.1109/ijcnn.2015.7280643 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.464.1735&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.464.1735&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.464.1735&rep=rep1&type=pdf https://doi.org/10.1016/s0165-0270(03)00004-9 https://doi.org/10.1016/s0165-0270(03)00004-9 https://doi.org/10.1016/s0165-0270(03)00004-9 https://doi.org/10.1016/s0165-0270(03)00004-9 https://doi.org/10.3390/s18082522 https://doi.org/10.3390/s18082522 https://doi.org/10.3390/s18082522 https://doi.org/10.1093/brain/67.3.178 https://doi.org/10.1093/brain/67.3.178 https://doi.org/10.1093/brain/67.3.178 https://doi.org/10.1093/brain/61.3.311 https://doi.org/10.1093/brain/61.3.311 https://doi.org/10.1093/brain/61.3.311 https://doi.org/10.1109/tra.2003.808873 https://doi.org/10.1109/tra.2003.808873 https://doi.org/10.1109/tra.2003.808873 https://doi.org/10.1109/tra.2003.808873 https://hermanwallace.com/download/the_abc_of_emg_by_peter_konrad.pdf https://hermanwallace.com/download/the_abc_of_emg_by_peter_konrad.pdf https://doi.org/10.1152/jn.00009.2006 https://doi.org/10.1152/jn.00009.2006 https://doi.org/10.1152/jn.00009.2006 https://doi.org/10.1152/jn.00555.2014 https://doi.org/10.1152/jn.00555.2014 https://doi.org/10.1152/jn.00555.2014 https://doi.org/10.1152/jn.00555.2014 https://doi.org/10.1088/0967-3334/33/2/195 https://doi.org/10.1088/0967-3334/33/2/195 https://doi.org/10.1088/0967-3334/33/2/195 https://doi.org/10.1016/j.proeng.2012.07.143 https://doi.org/10.1016/j.proeng.2012.07.143 https://doi.org/10.1016/j.proeng.2012.07.143 https://doi.org/10.1016/j.proeng.2012.07.143 https://doi.org/10.1016/j.proeng.2012.07.143 https://doi.org/10.1145/2702123.2702501 https://doi.org/10.1145/2702123.2702501 https://doi.org/10.1145/2702123.2702501 https://doi.org/10.1145/2702123.2702501 https://doi.org/10.3390/s130912431 https://doi.org/10.3390/s130912431 https://doi.org/10.3390/s130912431 https://doi.org/10.3390/s130912431 https://doi.org/10.1007/bf01712765 https://doi.org/10.1007/bf01712765 https://doi.org/10.1007/bf01712765 https://doi.org/10.1007/bf01712765 https://doi.org/10.3390/s110403545 https://doi.org/10.3390/s110403545 https://doi.org/10.3390/s110403545 https://doi.org/10.12659/msm.883927 https://doi.org/10.12659/msm.883927 https://doi.org/10.12659/msm.883927 https://doi.org/10.12659/msm.883927 https://doi.org/10.1016/j.jelekin.2006.06.001 https://doi.org/10.1016/j.jelekin.2006.06.001 https://doi.org/10.1016/j.jelekin.2006.06.001 https://doi.org/10.1016/j.jelekin.2006.06.001 https://doi.org/10.1016/j.apergo.2017.11.015 https://doi.org/10.1016/j.apergo.2017.11.015 https://doi.org/10.1016/j.apergo.2017.11.015 https://doi.org/10.1016/j.apergo.2017.11.015 https://www.ni.com/en-gb/innovations/white-papers/13/hardware-integration-with-ni-labview.html https://www.ni.com/en-gb/innovations/white-papers/13/hardware-integration-with-ni-labview.html https://doi.org/10.5220/0004594105000506 https://doi.org/10.5220/0004594105000506 https://doi.org/10.5220/0004594105000506 https://doi.org/10.5220/0004727802460253 https://doi.org/10.5220/0004727802460253 https://doi.org/10.5220/0004727802460253 https://bitalino.com/datasheets/revolution_emg_sensor_datasheet.pdf https://doi.org/10.1021/ac60214a047 https://doi.org/10.1021/ac60214a047 https://doi.org/10.1021/ac60214a047 https://doi.org/10.1109/ijcnn.2013.6706781 https://doi.org/10.1109/ijcnn.2013.6706781 m. cenit and v. gandhi / journal of mechatronics, electrical power, and vehicular technology 11 (2020) 64-74 74 in ieee international joint conference on neural networks, 2013. [58] w. lu, c. huang, k. hou, l. shi, h. zhao, z. li and j. qiu, "recurrent neural network approach to quantum signal: coherent state restoration for continuous-variable quantum key distribution," quantum information processing, vol. 17, (5), pp. 109, 2018. [59] n. miljković, n. popović, o. djordjević, l. konstantinović and t. b. šekara," ecg artifact cancellation in surface emg signals by fractional order calculus application," comput. methods programs biomed., vol. 140, pp. 259-264, 2017. [60] a. phinyomark, e. campbell and e. scheme, "surface electromyography (emg) signal processing, classification, and practical considerations," in biomedical signal processing, available online 13 november 2019. [61] c. gilliam, a. bingham, t. blu and b. jelfs, "time-varying delay estimation using common local all-pass filters with application to surface electromyography," in 2018 ieee international conference on acoustics, speech and signal processing (icassp), 2018. [62] a. syed, z. t. h. agasbal, t. melligeri and b. gudur, "flex sensor based robotic arm controller using micro controller," 2012. [63] d. copaci, e. cano, l. moreno and d. blanco, "new design of a soft robotics wearable elbow exoskeleton based on shape memory alloy wire actuators," applied bionics and biomechanics, vol. 2017, 2017. [64] d. copaci, d. blanco, a. martin-clemente and l. moreno, "flexible shape memory alloy actuators for soft robotics: modelling and control," international journal of advanced robotic systems, vol. 17, (1), pp. 1729881419886747, in press: september 28, 2019. [65] p. salvini, "on ethical, legal and social issues of care robots," in intelligent assistive robots, 2015. [66] z. dolic, r. castro and a. moarcas, "robots in healthcare: a solution or a problem?," policy department for economic, scientific and quality of life policies, directorate general for internal policies, european parliament, 2019. [67] p. maurice, l. allienne, a. malaisé and s. ivaldi, "ethical and social considerations for the introduction of human-centered technologies at work," in 2018 ieee workshop on advanced robotics and its social impacts (arso), 2018. [68] e. fosch-villaronga, c. lutz and a. tamò-larrieux, "gathering expert opinions for social robots’ ethical, legal, and societal concerns: findings from four international workshops," international journal of social robotics, pp. 1-18, 2019. [69] h. felzmann, a. kapeller, a. hughes and e. fosch-villaronga, "ethical, legal and social issues in wearable robotics: perspectives from the work of the cost action on wearable robots," in international conference on inclusive robotics for a better society, 2018. [70] d. greenbaum, "ethical, legal and social concerns relating to exoskeletons," acm sigcas computers and society, vol. 45, (3), pp. 234-239, 2016. [71] r. calo, "robotics and the lessons of cyberlaw," calif. law rev., pp. 513-563, 2015. [72] j. yang, k. abdel-malek and k. nebel, "the reach envelope of a 9 degree-of-freedom model of the upper extremity," international journal of robotics and automation, vol. 20, pp. 240–259, 2005. [73] k. bharadwaj and t. g. sugar, "kinematics of a robotic gait trainer for stroke rehabilitation," in proceedings 2006 ieee international conference on robotics and automation (icra 2006), 2006. https://doi.org/10.1109/ijcnn.2013.6706781 https://doi.org/10.1109/ijcnn.2013.6706781 https://doi.org/10.1007/s11128-018-1877-y https://doi.org/10.1007/s11128-018-1877-y https://doi.org/10.1007/s11128-018-1877-y https://doi.org/10.1007/s11128-018-1877-y https://doi.org/10.1007/s11128-018-1877-y https://doi.org/10.1016/j.cmpb.2016.12.017 https://doi.org/10.1016/j.cmpb.2016.12.017 https://doi.org/10.1016/j.cmpb.2016.12.017 https://doi.org/10.1016/j.cmpb.2016.12.017 https://doi.org/10.1007/978-981-13-9097-5_1 https://doi.org/10.1007/978-981-13-9097-5_1 https://doi.org/10.1007/978-981-13-9097-5_1 https://doi.org/10.1007/978-981-13-9097-5_1 https://doi.org/10.1109/icassp.2018.8461390 https://doi.org/10.1109/icassp.2018.8461390 https://doi.org/10.1109/icassp.2018.8461390 https://doi.org/10.1109/icassp.2018.8461390 https://doi.org/10.1109/icassp.2018.8461390 https://doi.org/10.4236/jsea.2012.55042 https://doi.org/10.4236/jsea.2012.55042 https://doi.org/10.1155/2017/1605101 https://doi.org/10.1155/2017/1605101 https://doi.org/10.1155/2017/1605101 https://doi.org/10.1155/2017/1605101 https://doi.org/10.1177/1729881419886747 https://doi.org/10.1177/1729881419886747 https://doi.org/10.1177/1729881419886747 https://doi.org/10.1177/1729881419886747 https://doi.org/10.1177/1729881419886747 https://doi.org/10.1007/978-3-319-12922-8_17 https://doi.org/10.1007/978-3-319-12922-8_17 https://www.europarl.europa.eu/regdata/etudes/idan/2019/638391/ipol_ida(2019)638391_en.pdf https://www.europarl.europa.eu/regdata/etudes/idan/2019/638391/ipol_ida(2019)638391_en.pdf https://www.europarl.europa.eu/regdata/etudes/idan/2019/638391/ipol_ida(2019)638391_en.pdf https://www.europarl.europa.eu/regdata/etudes/idan/2019/638391/ipol_ida(2019)638391_en.pdf https://doi.org/10.1109/arso.2018.8625830 https://doi.org/10.1109/arso.2018.8625830 https://doi.org/10.1109/arso.2018.8625830 https://doi.org/10.1109/arso.2018.8625830 https://doi.org/10.1007/s12369-019-00605-z https://doi.org/10.1007/s12369-019-00605-z https://doi.org/10.1007/s12369-019-00605-z https://doi.org/10.1007/s12369-019-00605-z https://doi.org/10.1007/978-3-030-24074-5_17 https://doi.org/10.1007/978-3-030-24074-5_17 https://doi.org/10.1007/978-3-030-24074-5_17 https://doi.org/10.1007/978-3-030-24074-5_17 https://doi.org/10.1007/978-3-030-24074-5_17 https://doi.org/10.1145/2874239.2874272 https://doi.org/10.1145/2874239.2874272 https://doi.org/10.1145/2874239.2874272 https://doi.org/10.2139/ssrn.2402972 https://doi.org/10.2139/ssrn.2402972 https://doi.org/10.2316/journal.206.2005.4.206-2738 https://doi.org/10.2316/journal.206.2005.4.206-2738 https://doi.org/10.2316/journal.206.2005.4.206-2738 https://doi.org/10.2316/journal.206.2005.4.206-2738 https://doi.org/10.1109/robot.2006.1642235 https://doi.org/10.1109/robot.2006.1642235 https://doi.org/10.1109/robot.2006.1642235 https://doi.org/10.1109/robot.2006.1642235 i. introduction ii. emg-based exoskeleton control iii. proposed semg based exoskeleton a. overall design and software iv. testing and evaluation a. structural test b. semg signal based on different spring reactive force v. ethical, societal, and legal (els) aspects in wearable robotics vi. conclusion declarations author contribution funding statement conflict of interest additional information references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology volume 12, 2021 authors index the articles in this volume were authored/co-authored by 67 authors from iraq, indonesia, taiwan, russian federation, republic of maldives, kingdom of saudi arabia, ghana, united arab emirates, australia, malaysia, turkey, and united kingdom. adha imam cahyadi, “effect of different core materials in very low voltage induction motors for electric vehicle,” 12(2):95-103 agung wibowo, “geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design,” 12(2):68-80 agus fanar syukri, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 ahmad fudholi, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 ahmad fudholi, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 ahmad rajani, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 aminuddin debataraja, “phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology,” 12(1):45-50 andri setiawan, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 andri joko purwanto, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 andri joko purwanto, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 ant. ardath kristi, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 anwar, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 ari wibawa budisantosa, “study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis,” 12(2):110-116 bambang sumantri, “local positioning system for autonomous vertical take-off and landing using ultra-wide band measurement ranging system,” 12(1):18-27 benjamin kommey, “an alternative design and implementation of a solid state on-load tap changer,” 12(2):104-109 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii brilly nurhalim, “vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications,” 12(2):117-125 cheku nurul aisyah, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 daniel opoku, “an alternative design and implementation of a solid state on-load tap changer,” 12(2):104-109 elvis tamakloe, “an alternative design and implementation of a solid state on-load tap changer,” 12(2):104-109 endro junianto, “a review of single-phase pressure drop characteristics microchannels with bends,” 12(1):38-44 erie martides, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 fakih irsyadi, “hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing,” 12(2):81-86 fransisco danang wijaya, “effect of different core materials in very low voltage induction motors for electric vehicle,” 12(2):95-103 ghalya pikra, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 gideon adom-bamfi, “an alternative design and implementation of a solid state on-load tap changer,” 12(2):104-109 goh li jin, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 hartono yudo, “study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis,” 12(2):110-116 hazim moria, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 henny sudibyo, “domestic component level analysis for multipurpose autonomous robot,” 12(2):8794 husam abdulrasool hasan, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 iftitah imawati, “effect of different core materials in very low voltage induction motors for electric vehicle,” 12(2):95-103 indra dwisaputra, “phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology,” 12(1):45-50 jooned hendrarsakti, “a review of single-phase pressure drop characteristics microchannels with bends,” 12(1):38-44 jumrianto, “proteus isis simulation for power factor calculation using zero crossing detector,” 12(1):28-37 kamaruzzaman sopian, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 ketut wirtayasa, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” 12(1):1-9 leonard rusli, “vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications,” 12(2):117-125 mariyam fazleena musthafa, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 viii merry indahsari devi, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 mohammad hossein yazdi, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 mohammad hossein yazdi, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 mohd hafidz ruslan, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 mohd yusof othman, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 muhammad fathul hikmawan, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” 12(1):1-9 muhammad fathul hikmawan, “geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design,” 12(2):68-80 muhammad kasim, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” 12(1):1-9 muhammad kasim, “geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design,” 12(2):68-80 muhammad yasirroni, “effect of different core materials in very low voltage induction motors for electric vehicle,” 12(2):95-103 muhammad zakiyullah romdlony, “hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing,” 12(2):81-86 mustafa yasin erten, “control of mobile robot formations using a-star algorithm and artificial potential fields,” 12(2):57-67 nelson luis manuel, “control of mobile robot formations using a-star algorithm and artificial potential fields,” 12(2):57-67 niam tamami, “local positioning system for autonomous vertical take-off and landing using ultrawide band measurement ranging system,” 12(1):18-27 nihat i̇nanç, “control of mobile robot formations using a-star algorithm and artificial potential fields,” 12(2):57-67 nilofar asim, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 nofriyani, “phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology,” 12(1):45-50 nurul shahirah rukman, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 ocid mursid, “study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis,” 12(2):110-116 prima kristalina, “local positioning system for autonomous vertical take-off and landing using ultrawide band measurement ranging system,” 12(1):18-27 pudji irasari, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” 12(1):1-9 puji widiyanto, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” 12(1):1-9 putri adia utari, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 ix rakhmad indra pramana, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 rakhmad indra pramana, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 ridwan arief subekti, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 robeth viktoria manurung, “phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology,” 12(1):45-50 royan, “proteus isis simulation for power factor calculation using zero crossing detector,” 12(1):2837 roni permana saputra, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 rudi darussalam, “experimental and model validation of photovoltaic-thermal (pvt) air collector: exergy analysis,” 12(1):10-17 rusman rusyadi, “vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications,” 12(2):117-125 tri admono, “study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis,” 12(2):110-116 vita susanti, “domestic component level analysis for multipurpose autonomous robot,” 12(2):87-94 wilma amiruddin, “study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis,” 12(2):110-116 zeki ahmed darwish, “bi-fluid cooling effect on electrical characteristics of flexible photovoltaic panel,” 12(1):51-56 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 x mechatronics, electrical power, and vehicular technology volume 12, 2021 affiliation index centre for deep sea research, indonesian institute of sciences (lipi), indonesia 51 department of air conditioning and refrigeration engineering, al esra'a university college, iraq 51 department of electrical & electronics engineering, kırıkkale university, turkey 57 department of electrical engineering and informatics, vocational college, universitas gadjah mada, indonesia 81 department of electrical engineering and information technology, universitas gadjah mada, indonesia 95 department of electrical engineering, national taiwan university of science and technology, taiwan 1 department of electrical engineering, universitas islam indonesia, indonesia 95 dept. of electric power generation stations, network and supply systems, institute of engineering and technology, south ural state university, russian federation 10, 51 department of energy, ministry of environment, republic of maldives 10 department of mechanical engineering technology, yanbu industrial college, kingdom of saudi arabia 10, 51 department of naval architecture, faculty of engineering, diponegoro university, indonesia 110 electrical engineering department, politeknik elektronika negeri surabaya, indonesia 18 electrical engineering department, politeknik manufaktur negeri bangka belitung, indonesia 45 electrical engineering department, politeknik negeri jakarta, indonesia 45 faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia 38, 68 kwame nkrumah university of science and technology, pmb knustcoe, ghana 104 kwame nkrumah university of science and technology, pmb knustee, ghana 104 mechatronics department, swiss german university, indonesia 117 ministry of education, united arab emirates 51 research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), indonesia 1, 10, 38, 51, 68, 87, 110 research centre for electronics and telecommunications, indonesian institute of sciences, indonesia 45 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xi research center for policy and management of science, technology, and innovation, indonesian institute of sciences, indonesia 87 robot intelligence laboratory, dyson school of design engineering, imperial college london, united kingdom 87 school of electrical engineering and telecommunications, university of new south wales, australia 1, 68 school of electrical engineering, telkom university, indonesia 81 solar energy research institute, universiti kebangsaan malaysia, malaysia 10, 51 system and information technology department, ivet university, indonesia 28 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 xii journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kırıkkale universitesi ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiii dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, s.t., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea yusie rizal, ph.d. cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh., tembalang, semarang 50275, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiv suprapto, ph.d. departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. ph.h. mustafa no. 23, bandung, jawa barat, indonesia alexander christantho budiman, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. rina ristiana technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. anto tri sugiarto, m.eng. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. eng. aam muharam, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.eng. edy riyanto, s.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. anwar muqorobin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia bambang wahono, m.eng., ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. natalita maulani nursam research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia dr. joko hariyono, s.t., m.eng. government of yogyakarta special region komplek kepatihan, danurejan yogyakarta, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. deni shidqi khaerudini, s.si., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. irwan purnama, m.sc.eng. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xv sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia aditya nugraha, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi azhari, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andry masri, m.sn. department of product design, faculty of art and design, institut teknologi nasional jl. ph.h. mustofa no.23, bandung, jawa barat, indonesia roni permana saputra, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sudirja, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia veny luvita, m.t. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia mulia pratama, s.t., m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia asep nugroho, s.si, m.eng, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvi publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (research centre for electrical power and mechatronics – indonesian institute of sciences). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvii 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident, they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xviii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xix preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xx presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xxi instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xxii • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor, city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software microsoft word vol03_no1 mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved analysis of inverse angle method for controlling two degree of freedom manipulator analisis metode sudut balik untuk pengendalian mekanisme penggerak dua derajat kebebasan hendri maja saputra a,*, zainal abidin b, estiko rijanto a a pusat penelitian tenaga listrik dan mekatronik lipi kompleks lipi jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia b teknik mesin, fakultas teknik mesin dan dirgantara itb jl. ganesha 10, bandung 40132, indonesia received 23 may 2012; received in revised form 7 june 2012; accepted 7 june 2012 published online 31 july 2012 abstract driver mechanism with two degree of freedom (mp 2-dk) is a robotic device that can be used for various applications such as turret drive system, gutling gun, launcher, radar antennas, and communications satellite antennas. the precision and the speed of a mp 2-dk are determined by its control system. the calculation inverse angle due to interference in six degree of freedom is necessary to control a mp 2 dk. this paper analyses three calculation methods of inverse angle which are iteration method using jacobian matrix, reduction of matrix equations using positioning geometry, and an analytical derivation using a rotation matrix. the simulation results of the three methods showed that the first and the third methods could visually demonstrate three rotational disturbances, whereas the second method could only demonstrate the pitch and yaw (py) disturbances. the third method required less processing time than the first and the second methods. the best method based on this research was the method of rotation matrix. key words: driver mechanism, control, inverse angle, jacobian, geometry abstrak mekanisme penggerak dua derajat kebebasan (mp 2-dk) merupakan peralatan robotik yang dapat digunakan untuk berbagai aplikasi seperti sistem penggerak turret, peluncur roket/rudal, antena radar, dan antena komunikasi satelit. tingkat presisi dan kecepatan gerak mp 2-dk sangat ditentukan oleh sistem kendalinya. untuk pengendalian mp 2-dk perlu dihitung sudut balik akibat gangguan enam derajat kebebasan (rotasi: roll, pitch, yaw, translasi:bx, by, bz). makalah ini membahas hasil analisis 3 metode perhitungan sudut balik, antara lain metode iterasi menggunakan matriks jacobian, penurunan persamaan geometri menggunakan matriks posisi, dan penurunan secara analitis menggunakan matriks rotasi. hasil simulasi dari ketiga metode membuktikan bahwa metode pertama dan ketiga secara visual dapat mempresentasikan ketiga gangguan rotasi yang terjadi, sedangkan metode kedua hanya mempresentasikan gangguan pitch dan yaw (py) saja. metode ketiga memerlukan waktu proses lebih cepat daripada metode pertama dan metode kedua. metode yang terbaik berdasarkan penelitian ini adalah metode ketiga (metode matriks rotasi). kata kunci: mekanisme penggerak, pengendalian, sudut balik, jacobian, geometri. i. pendahuluan kepresisian merupakan hal penting yang ingin dicapai dalam bidang robot dan mekatronik. kepresisian dalam bidang mekatronik sangat tergantung pada masalah kinematika, dinamika dan teknik kontrol. mekanisme penggerak dua derajat kebebasan (mp 2-dk) adalah sebuah contoh peralatan mekatronik yang dapat digunakan untuk berbagai aplikasi seperti sistem penggerak turret, peluncur roket/rudal, antena radar, dan antena komunikasi satelit. penelitian terkait kinematika, dinamika, dan sistem kontrol terus-menerus dilakukan untuk memperoleh mp 2-dk yang mampu mempertahankan arah sasaran akibat gangguan rotasi (roll, pitch, yaw/rpy) dan translasi (bx, by, bz). rotasi koordinat lokal terhadap koordinat * corresponding author. tel: +62-22-2503055 e-mail: hendri_maja@yahoo.co.id h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 10 global dapat diturunkan melalui interprestasi sudut tetap xyz (fixed xyz), sudut euler zyx, dan sudut euler zyz [1]. metode kinematika balik berguna untuk menentukan sudut manipulator lengan robot untuk mencapai posisi tertentu sebagaimana telah dijelaskan di beberapa referensi [1, 2]. penelitian mengenai kinematika balik dengan metode geometri dan jacobian untuk kepala robot rochester dapat dilihat pada [3]. kinematika balik melalui proses komputasi dengan algoritma jacobian pseudoinverse dapat dilihat pada [4, 5]. algoritma kinematika balik jacobian untuk manipulator statis dan robot mobil dapat dilihat pada [6]. pada [7] dibahas algoritma numerik untuk menyelesaikan permasalahan kinematika balik dengan pendekatan teknik extended jacobian yang dibandingkan dengan metode inverse jacobian. kinematika balik manipulator secara umum dapat diselesaikan dengan cara yang sederhana ataupun dengan metode lain yang lebih canggih seperti neural network [8-10], dengan perangkat lunak anfis [11-13], pendekatan generikneuron [14], neuro fuzzy [15], dan algoritma genetik [16]. istilah kinematika balik biasa digunakan untuk penentuan sudut agar mencapai posisi cartesian tertentu. penelitian ini difokuskan pada penentuan sudut (θ1 dan θ2) yang harus dibentuk akibat rotasi sudut rpy (γ,  β,  α), sehingga di sini digunakan istilah ‘sudut balik’ yang dapat dilihat pada gambar 1 dan 2. tujuan makalah ini adalah merekomendasikan metode yang optimal untuk digunakan sebagai kompensasi gangguan rotasi akibat pergerakan platform dengan asumsi kendaraan berada pada posisi tertentu (tidak ada pergerakan translasi). metode yang dibandingkan adalah iterasi menggunakan matriks jacobian, penurunan persamaan geometri menggunakan matriks posisi, dan penurunan secara analisis menggunakan matriks rotasi. penelitian lain yang membandingkan/membuktikan hasil dari ketiga metode ini belum pernah dilakukan, baik simulasi maupun eksperimen. gambar 1. ilustrasi gangguan rotasi roll  γ , pitch β , dan yaw  α dan translasi (bx, by, bz) [4]. gambar 2. perbedaan kinematika balik dengan sudut balik. ii. pemodelan kinematika pemodelan kinematika mekanisme penggerak dua derajat kebebasan (mp 2-dk) dibagi menjadi dua bagian. bagian yang pertama adalah model gangguan platform enam derajat kebebasan yaitu rotasi (roll, pitch, yaw) dan translasi (bx, by, bz), sedangkan bagian kedua adalah model kinematika mekanisme mp 2-dk. gambar 3 menunjukkan komunikasi satelit sebagai objek penelitian mp 2-dk. a. model gangguan platform platform kendaraan darat, laut, dan udara dengan mekanisme mp 2-dk yang mengalami gangguan rotasi dan translasi yang dimodelkan dengan menggunakan sudut euler zyx dijelaskan dengan persamaan (1) berikut: rotasi, , ,         , , (1) dimana sα = sin(α), cα = cos(α), sβ = sin(β), cβ  = cos(β), sγ = sin(γ), dan cγ = cos(γ), sedangkan gangguan translasinya mengikuti persamaan (2): ,     (2) gambar 3. mp 2-dk komunikasi satelit. h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 11 kedua jenis gangguan (rotasi dan translasi) ini dapat disatukan ke dalam matriks transformasi homogen gangguan platform (4x4) seperti persamaan (3). , , 0 1 (3) b. model kinematika mekanisme model kinematika diturunkan dengan notasi denavit-hartenberg (notasi d-h) yang biasa digunakan dalam bidang robotika. koordinat yang menunjukkan simbol berbagai parameter dari mekanisme dua derajat kebebasan yang hampir serupa dapat dilihat pada [4]. untuk mekanisme mp 2-dk, matriks transformasi homogennya adalah seperti persamaan (4a). 0 0 0 0 1 (4a) dimana:       notasi l  merupakan panjang total lengan 2 (l2) ditambah dengan jarak ujung lengan 2 ke objek yang menjadi target (lx) atau secara matematis ditulis . matriks jacobian yang telah diturunkan dari matriks di atas adalah 0 0 0 0 0 0 ; (4b) dimana:     0  c. transformasi homogen total diagram blok penurunan persamaan transformasi homogen total untuk mp 2-dk dapat dilihat pada gambar 4. matriks transformasi homogen total diperoleh dengan mengalikan matriks homogen gangguan platform dengan matriks homogen mekanisme ke target, sehingga persamaannya berbentuk seperti persamaan (5): 0 0 0 1 (5) dimana n , n , n , s , s , s ,a , a , a ,p , p , p didefinisikan pada persamaan (6 s/d 9) dan persamaan (18 s/d 27). iii. metoda sudut balik penentuan sudut balik dapat diturunkan melalui tiga metode, yaitu: iterasi menggunakan matriks jacobian, penurunan secara geometri dari matriks translasi, dan analisis dari matriks rotasi. pada penelitian ini, setiap selesai uraian dari masing-masing metode, akan dibuat simulasi menggunakan perangkat lunak matlab yang dilakukan dengan dua tahap. pada tahap pertama, gangguan rotasi yang diberikan hanya berupa pitch dan yaw saja (py, dengan gangguan roll = 0). tahap kedua yakni dengan memberikan gangguan berupa roll, pitch, dan yaw (rpy). parameter yang digunakan untuk simulasi dapat dilihat pada tabel 1. gangguan rpy dimasukkan pada simulasi menggunakan interprestasi sudut euler zyx dengan waktu cuplik 56 milidetik. gambar 4.transformasi homogen total untuk sudut balik. h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 12 galat dari hasil simulasi untuk tahap pertama dihitung berdasarkan selisih antara hasil metode matriks jacobian, metode matriks posisi, dan metode matriks rotasi terhadap masukan gangguan yang diberikan (py), sedangkan galat tahap kedua dihitung berdasarkan selisih antara metode kedua atau metode ketiga terhadap metode pertama. simulasi untuk ketiga metode dibuat dalam satu program, dimana ketiga metode memperoleh masukan (gangguan) yang sama, lalu dari nilai masukan tersebut dilakukan perhitungan sudut balik untuk metode matriks jacobian, metode matriks posisi, dan metode matriks rotasi. persamaan untuk memperoleh nilai sudut balik yang digunakan berbeda. persamaan untuk metode matriks jacobian yakni menggunakan algoritma sebagaimana yang ditunjukkan oleh tabel 2, yang kemudian dilakukan proses iterasi. persamaan yang digunakan dalam pemrograman untuk melakukan perhitungan metode matriks posisi adalah persamaan (12) sampai dengan persamaan (17) yang diperoleh melalui perhitungan secara langsung berdasarkan geometri, sedangkan untuk metode matriks rotasi menggunakan persamaan (28) dan persamaan (29) yang diperoleh melalui analisis. uraian secara lengkap dari ketiga metode yang telah dijelaskan adalah sebagai berikut. tabel 1 parameter simulasi. parameter nilai (satuan) gangguan translasi platform kendaraan, [bx by bz] [0 0 0] (m) jarak ujung lengan 2 ke target, lx  1.000 (m) frekuensi gangguan, [fr fp fy] [1,25 0,75 0,22] (hz) amplitudo gangguan, [mr mp my] [pi/4 pi/3 pi/2] (rad) offset gangguan, [or op oy] [0 2 4] (rad) panjang lengan mp 2-dk, [l1 l2] [0,57 1,13] (m) a. metode matriks jacobian pada metode ini dilakukan iterasi dengan menggunakan pseudoinverse dari matriks jacobian mp 2-dk. algoritma yang digunakan dapat dilihat pada tabel 2. sudut balik yang dihasilkan oleh metode ini terhadap gangguan pitch dan yaw (py) dapat dilihat pada gambar 5a, sedangkan galat sudut balik terhadap gangguan sudut ditunjukkan pada gambar 5b. pada gambar 5 tampak bahwa galat maksimum dari sudut balik elevasi maupun sudut balik azimut yang dihasilkan memiliki nilai yang sangat kecil. gambar 6 menunjukkan sudut balik yang dihasilkan oleh metode matriks jacobian terhadap gangguan rpy. pada gambar tersebut dapat dilihat bahwa sudut azimut dan elevasi mengalami interfensi dari gangguan roll. khusus untuk simulasi tahap kedua, metode ini (gambar 6) akan dijadikan sebagai pembanding bagi metode lainnya. tabel 2 algoritma kinematik balik metode jacobian. no proses 1 hitung matriks jacobian menggunakan persamaan (5) 2 hitung pseudoinverse dari matriks jacobian 3 hitung perubahan sudut sendi ∆ ∆ dimana ∆ diperoleh dari nilai pada persamaan (6) yang dimasukkan ke dalam persamaan ∆ 0,5 0,5 0,5 4 implementasikan perubahan sudut ∆ 5 normalisasi perubahan sudut ∆ 6 nilai θ yang sesuai ditemukan, apabila nθ lebih kecil dari nilai toleransi yang diinginkan. (a) (b) gambar 5.(a) sudut balik metode matriks jacobian terhadap gangguan py; (b) galat sudut. 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -100 -80 -60 -40 -20 0 20 40 60 80 100 sudut balik (θ) dengan metode 1 waktu [detik] s u d u t [d e ra ja t] γroll βpitch αyaw θazimut θelevasi 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -5 0 5 10 15 20 x 10 -6 galat sudut balik (θ) metode 1 terhadap pitch & yaw waktu [detik] g a la t s u d u t [d e ra ja t] azimut elevasi x 6 h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 13 gambar 6. sudut balik metode matriks jacobian terhadap gangguan rpy. b. metode matriks posisi metode ini merupakan penurunan sudut balik menggunakan persamaan geometri dari mp 2-dk dengan memanfaatkan matriks posisi dari transformasi homogen total, dimana:   (6)    (7)    (8)  gambar 7 menunjukkan model kinematika mekanisme mp 2-dk untuk penurunan sudut balik dengan metode geometri. untuk penyelesaian persamaan diatas, diperlukan nilai z dan r, dimana nilai tersebut dapat dihitung dari persamaan (10) dan (11)     (9) (10) gambar 7. model kinematika mekanisme mp 2-dk. terdapat tiga persamaan yang dapat dibentuk untuk menentukan sudut θ dan tiga persamaan untuk menentukan sudut θ , yaitu: • sudut azimut     (11)   (12)   (13) • sudut elevasi (14) (15)  (16) sudut balik yang dihasilkan oleh metode ini terhadap gangguan pitch dan yaw (py) dapat dilihat pada gambar 8a, sedangkan galat sudut balik terhadap gangguan sudut ditunjukkan pada gambar 8b. pada gambar 8 dapat dilihat bahwa galat sudut balik yang dihasilkan berupa sudut elevasi yang memiliki nilai yang jauh lebih besar jika dibandingkan dengan galat sudut azimut. sudut balik yang dihasilkan oleh metode ini terhadap (a) (b) gambar 8. (a) sudut balik metode matriks posisi terhadap gangguan py; (b) galat sudut. 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -150 -100 -50 0 50 100 sudut balik (θ) dengan metode 1 waktu [detik] s u d u t [d e ra ja t] γroll βpitch αyaw θazimut θelevasi 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -100 -80 -60 -40 -20 0 20 40 60 80 100 sudut balik (θ) dengan metode 2 waktu [detik] s u d u t [d e ra ja t] γroll βpitch αyaw θazimut~sin θelevasi~sin θazimut~cos θelevasi~cos θazimut~stan θelevasi~tan 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 0.03 0.04 galat sudut balik (θ) metode 2 terhadap pitch & yaw waktu [detik] g a la t s u d u t [d e ra ja t] azimut~sin elevasi~sin azimut~cos elevasi~cos azimut~tan elevasi~tan contoh interfensi gangguan roll h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 14 (a) (b) gambar 9. (a) sudut balik metode matriks posisi terhadap gangguan rpy; (b) galat sudut. gangguan rpy dapat dilihat pada gambar 9a, sedangkan galat sudut balik terhadap gangguan sudut ditunjukkan pada gambar 9b. pada gambar 9, galat yang dihasilkan sangat besar, dimana galat sudut azimut maksimum adalah 40,79 derajat dan galat sudut elevasi maksimum adalah 9,79 derajat. berdasarkan hasil ini, maka dapat disimpulkan bahwa penggunaan metode ini untuk mendapatkan sudut balik dapat menyebabkan ketidakakuratan sudut mp 2-dk. c. metode matriks rotasi metode ini dilaksanakan dengan menurunkan secara analisis matriks rotasi dari matriks homogen total, r yaitu: (17) dimana:   18     19     20     21     22     23     24     25     26   setiap baris atau kolom dari matriks rotasi, r dapat dinormalisasi (penjumlahan dari setiap komponen yang dikuadratkan merupakan vektor unit atau sama dengan satu). dengan menurunkan secara analisis kolom ketiga untuk mencari dan baris ketiga untuk mencari , maka dapat diperoleh   (27) (28) sudut balik yang dihasilkan oleh metode ini terhadap gangguan pitch dan yaw (py) dapat dilihat pada gambar 10a, sedangkan galat sudut balik terhadap gangguan sudut ditunjukkan pada gambar 10b. pada gambar 10 dapat dilihat bahwa galat maksimum sudut balik yang dihasilkan sangat kecil yaitu 7,11 x 10-15 derajat. (a) (b) gambar 10. (a) sudut balik metode matriks rotasi terhadap gangguan py; (b) galat sudut. 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -150 -100 -50 0 50 100 sudut balik (θ) dengan metode 2 waktu [detik] s u d u t [d e ra ja t] θazimut~metoda1 θelevasi~metoda1 θazimut~sin θelevasi~sin θazimut~cos θelevasi~cos θazimut~tan θelevasi~tan 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -40 -30 -20 -10 0 10 20 30 40 50 galat sudut balik (θ) metode 2 terhadap metode 1 waktu [detik] g a la t s u d u t [d e ra ja t] azimut~sin elevasi~sin azimut~cos elevasi~cos azimut~tan elevasi~tan 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -100 -80 -60 -40 -20 0 20 40 60 80 100 sudut balik (θ) dengan metode 3 waktu [detik] s u d u t [d e ra ja t] γroll βpitch αyaw θazimut θelevasi 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -8 -6 -4 -2 0 2 4 6 8 x 10 -15 galat sudut balik (θ) metode 3 terhadap pitch & yaw waktu [detik] g a la t s u d u t [d e ra ja t] azimut elevasi contoh perbedaan metoda 2 dengan metoda 1 x 15 sudu terhadap gambar terhadap gambar sudut ba sudut ba galat sud iv. p perbandi metode y 3 dan t ketiga m juga me dalam p tabel 3 galat mak metode matriks ja matriks posisi matriks rotasi gambar 12 gangguan h.m gamb ut balik yang p gangguan 11a, seda p gangguan 11b. pada alik yang dih alik metode dut yang terja embahas ingan galat yang diguna abel 4. wak metode dalam erupakan ha penelitian. w ksimum terhada acobian sin cos tan analisis 2. perbandingan py. 0 0.5 -150 -100 -50 0 50 100 s u d u t [d e ra ja t] m. saputra et al. / (a) bar 11. (a) sudu g dihasilkan rpy dap angkan gal n sudut di gambar 11a hasilkan ham matriks jaco adi juga relat san t maksimu akan dapat d ktu proses pe m menghasi al yang pe waktu prose ap gangguan py sudut balik ( azimut 1,42x10-14 1,59x10-11 3,35x10-13 1,42x10-14 7,11x10-15 n waktu proses 5 1 1.5 2 2. sudut balik (θ) de waktu / mechatronics, e ) ut balik metode oleh metod pat dilihat lat sudut b itunjukkan a tampak ba mpir sama de obian, sedan tif kecil. um dari k ilihat pada t erhitungan u lkan sudut b erlu diperhat es yang dire y. (derajat) elevasi 1,84x10-5 0,03 0,03 0,02 7,11x10-1 ketiga metode 5 3 3.5 4 4 engan metode 3 [detik] θazimut~me θelevasi~me θazimut~me θelevasi~me conto perbedaan me 3 dengan met electrical power, matriks rotasi t de ini pada balik pada ahwa engan ngkan ketiga tabel untuk balik tikan ekam 5 s p g g m c te k m m d s m r p g k p t g m m p m ro untuk g g 4.5 5 etoda1 etoda1 etoda3 etoda3 oh etoda toda 1 and vehicular t terhadap gangg secara realti perhitungan d gangguan py gambar 12 m matriks posi cepat (tangen etapi terjad kosinus dan memiliki wak matriks posi dibandingkan secara visu menunjukkan realtime p perhitungan d gangguan r karakter yang pada gambar tabel 4 galat maksimum metode matriks posisi si co ta matriks otasi an gambar 13. perb gangguan rpy. 0 0.5 1 -0.03 -0.02 -0.01 0 0.01 0.02 0.03 galat s g a la t s u d u t [d e ra ja t] technology 03 (20 (b) guan rpy; (b) g ime pada sa dengan ketig y dapat dil memberikan i isi memilik n, sinus, ko di ‘loncatan n tangen. m ktu proses le isi, tetapi ja n metode ual lebih n waktu pros ada saat dengan ketig rpy. gam g hampir ser r ini tampak m terhadap gang gal azi in 40,7 os 40,7 an 40,7 nalisis 0,03 bandingan wak 1.5 2 2.5 3 udut balik (θ) metode 3 terhad waktu [detik] 012) 9-16 galat sudut. aat prosesor ga metode ak lihat pada g informasi ba i waktu pr sinus secara n’ untuk metode ma ebih lambat auh lebih ce matriks jac stabil. g ses yang dir prosesor ga metode ak mbar 13 m rupa dengan k bahwa met gguan rpy. lat maksimum mut e 79 9 79 9 79 9 3 0 ktu proses ketiga 3.5 4 4.5 5 dap metode 1 azimut elevasi 15 r melakukan kibat adanya gambar 12. ahwa metode roses paling a berurutan), penggunaan atriks rotasi dari metode epat apabila cobian dan gambar 13 ekam secara melakukan kibat adanya menunjukkan gambar 12. tode matriks (derajat) elevasi 9,75 9,79 9,77 0,02 a metode untuk n a . e g , n i e a n 3 a n a n . s k h.m. saputra et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 9-16 16 posisi memiliki waktu proses paling cepat (tangen, sinus, dan kosinus secara berurutan), tetapi terjadi ‘loncatan’ untuk penggunaan kosinus. metode matriks rotasi memiliki waktu proses lebih lambat dari metode matriks posisi, tetapi jauh lebih cepat apabila dibandingkan metode matriks jacobian dan secara visual lebih stabil. v. kesimpulan metode matriks jacobian dan metode matriks rotasi secara visual dapat menggambarkan interfensi gangguan rpy dengan jelas, sedangkan pada metode matriks posisi hanya menggambarkan interfensi gangguan pitch dan yaw saja. dari simulasi tahap kedua, galat maksimum metode matriks posisi terhadap metode matriks jacobian adalah 40,79 derajat (azimut) dan 9,79 derajat (elevasi), sedangkan galat maksimum metode matriks rotasi terhadap metode matriks jacobian adalah 0,03 derajat (azimut) dan 0,02 derajat (elevasi). metode yang paling optimal untuk memperoleh sudut balik mp 2-dk berdasarkan hasil simulasi di atas adalah dengan menggunakan metode matriks rotasi, karena dapat menginterprestasikan gangguan rpy dengan waktu proses yang jauh lebih cepat dibandingkan metode matriks jacobian dan lebih stabil jika dibandingkan metode matriks posisi. prosedur penelitian ini diawali dengan melakukan simulasi, sehingga kesimpulan yang diperoleh pada pembahasan ini baru analisa dari hasil simulasi. ekperimen untuk memperkuat hipotesis atau kesimpulan akan dilakukan pada tahapan selanjutnya. referensi [1] j.j. craig, introduction to robotics: mechanics and control, 3rd ed. canada, usa: pearson prentice hall, 2005. [2] f.l. lewis, d.m. dawson, and c.t. abdallah, robot manipulator control theory and practice, 2nd ed. new york, usa: marcel dekker, inc., 2004. [3] j. soong and c. brown, "inverse kinematics and gaze stabilization for the rochester robot head," computer science department, the univ. of rochester, ny 14627, technical report 394 agustus 1991. [4] h.m. saputra, e. rijanto, "analisis kinematik dan dinamik mekanisme penggerak 2-dof untuk antena bergerak pada komunikasi satelit," teknologi indonesia, vol. 32, no.1, pp. 21-29, 2009. [5] a. aristidou, j. lasenby, "inverse kinematics: a review of existing techniques and introduction of a new fast iterative solver," university of cambridge, technical report cued/f-infeng/tr-632, 2009. [6] k. tchon, j. karpinska, and m. janiak, "approximation of jacobian inverse kinematics algorithms," int. j. appl. math. comput. sci., vol. 19, pp. 519–531, 2009. [7] m. šoch and r. lórencz, "solving inverse kinematics – a new approach to the extended jacobian technique," acta polytechnica, vol. 45, no. 2, pp. 21-26, 2005. [8] y. feng, w. yao-nan, and y. yi-min, "inverse kinematics solution for robot manipulator based on neural network under joint subspace," international journal of cmputers and communications, vol. 7, no.3, pp. 459-472, september 2012. [9] a. olaru, s. olaru, d. paune , "assisted research and optimization of the proper neural network solving the inverse kinematics problem," in proc. of 2011 int. con. on optimization of the robots and manipulators, romania, 26-28 mei 2011. [10] z. bingul, h.m. ertunc, and c. oysu, "comparison of inverse kinematics solutions using neural network for 6r robot manipulator with offset," in computational intelligence methods and applications ieee, istanbul, 2005. [11] l. das, "prediction of inverse kinematics solution of a redundant manipulator using anfis," national institute of technology, rourkela, master thesis 2012. [12] e. yazid, e. rijanto, "invers kinematic mapping of 6 dof articulator using anfis (adaptive neuro-fuzzy inference system)," in seminar nasional teknologi simulasi 2007, yogyakarta, 2007, pp. f31-f38. [13] s. alavandar and m.j. nigam, "inverse kinematics solution of 3dof planar robot using anfis," int. j. of computers, communications & control, vol. iii, pp. 150-155, 2008. [14] r. koker, "a neuro-genetic approach to the inverse kinematics solution of robotic manipulators," scientific research and essays, vol. 6, pp. 2784-2794, juli 2011. [15] s. alavandar, m. j. nigam, "neuro-fuzzy based approach for inverse kinematics solution of industrial robot manipulators," int. j. of computers, communications & control, vol. iii, no. 3, pp. 224-234, 2008. [16] j. ramírez a., and a. rubiano f., "optimization of inverse kinematics of a 3r robotic manipulator using genetic algorithms," in world academy of science, engineering and technology 59, 2011, pp. 1425-1430. mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by national research and innovation agency (brin) formerly indonesian institutes of sciences (lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: https://mev.lipi.go.id all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev is sinta 1 accredited by kementerian pendidikan, kebudayaan, riset, dan teknologi republik indonesia via national journal accreditation (arjuna) accreditation platform. https://sinta.kemdikbud.go.id/j ournals/profile/814 postal address mev journal secretariat: research center for smart mechatronics, brin komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: mev@mail.lipi.go.id https://mev.lipi.go.id/ https://sinta.kemdikbud.go.id/journals/profile/814 https://sinta.kemdikbud.go.id/journals/profile/814 mailto:mev@mail.lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: https://mev.lipi.go.id/mev/login need a username/password? go to registration at: https://mev.lipi.go.id/mev/user/r egister registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate®. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. currently, mev has been completed csab review and accepted for scopus inclusion cc license mev journal by national research and innovation agency (brin) allows reuse and remixing of its content under a cc by-ncsa creative commons attribution-noncommercialsharealike 4.0 international license. permissions beyond the scope of this license may be available at https://mev.lipi.go.id. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nclicensed work does not necessarily mean you have violated the term. https://mev.lipi.go.id/mev/login https://mev.lipi.go.id/mev/user/register https://mev.lipi.go.id/mev/user/register http://www.brin.go.id/ http://www.brin.go.id/ http://www.brin.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 editor-in-chief dr. haznan abimanyu, dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences bandung 40135, indonesia associate editor (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi bandung, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia prof. tapan kumar saha electrical engineering, the university of queensland, australia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, universitas sebelas maret surakarta, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology, japan prof. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, indonesia prof. dr. bambang riyanto trilaksono school of electrical engineering and informatics, bandung institute of technology, indonesia prof. keum shik hong dept. of mechanical engineering, pusan national university, korea, republic of prof. taufik director of electric power institute, california polytechnique, united states prof. dr. adi soeprijanto dept. of electrical engineering, institut teknologi sepuluh nopember (its), indonesia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology, indonesia assoc. prof. hazim moria department of mechanical engineering, yanbu industrial college, saudi arabia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, australia assoc. prof. roonak daghigh university of kurdistandisabled, sanandaj, iran, islamic republic of asst. prof. mohammad h. yazdi mechanical eng. dept., islamic azad university, iran, islamic republic of dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales, australia dr. ahmad fudholi solar energy research institute, universiti kebangsaan malaysia, malaysia dr. ali h.a. al-waeli solar energy research institute, universiti kebangsaan malaysia, malaysia george anwar, ph.d. university of california, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia, indonesia riza muhida, ph.d. stkip surya, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia advisory editor prof. ocktaeck lim school of mechanical engineering, university of ulsan, korea, republic of prof. dr. endra joelianto engineering physics, bandung institute of technology, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 © 2022 national research and innovation agency. some rights reserved. this journal and the individual contributions contained in it are protected under copyright by national research and innovation agency. and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 foreword from editor-in-chief it is my pleasure to welcome you to the 1st issue of volume 13 in the year 2022 of the journal of mechatronics, electrical power, and vehicular technology (mev), a peer-reviewed and broadscope international journal. this journal aims to bridge the gap in mechatronics, electrical power, and vehicular technology and is designed to advance scientific knowledge and foster innovative engineering solutions. it addresses both academics and practicing professionals, which has become an increasingly recognized international journal in the past years and indexed by many internationally recognized indexers. this issue consists of ten papers written by authors from different countries, such as taiwan, malaysia, germany, turkey, australia, united kingdom, south korea, vietnam, japan, thailand, and indonesia. the articles span a wide range of topics, from control system of robotic area to the study of carbon electrode sensitivity enhancement. therefore, they may be classified as follows. the first paper investigates pattern recognition based movement control and gripping forces control system on arm robot model using labview. the second paper identifies design and application of models reference adaptive control (mrac) on ball and beam. the third paper presents the load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok. the fourth paper discuss the improvement of power grid stability and load distribution using diesel excitation controller. the fifth paper in this issue aims to design and kinematic analysis of a two-dof moving platform as a base for a car simulator. the sixth paper investigates the state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system. the seventh paper explains the fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology. the eighth paper studies the two-sided manual machining method for three-axis cnc milling machine for small and mediumsized enterprises. the ninth paper investigates the production of hydrogen gas from water electrolysis on motorcycle engine. last paper is about carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite. since the first volume, our journal provides discretion in financial terms by waiving the article processing charge. finally, as the editor-in-chief of this promising journal, i would like to acknowledge our immense gratitude to our international editorial board members, reviewers, and authors for their excellent works and remarkable contributions. each issue of this journal offers valuable reports and articles to the practitioners and research experts. we encourage academic and research professionals to submit manuscripts on practical and scientific key issues in mechatronics, electrical power, and vehicular technology of all disciplines. we are looking forward to receiving extraordinary manuscripts and promoting cutting-edge technology development. we hope this publication will contribute to the enhancement of science and technology. bandung, july 2022 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 ii list of contents pattern recognition based movement control and gripping forces control system on arm robot model using labview nur jamiludin ramadhan, noval lilansa, afaf fadhil rifa'i , hoe dinh nguyen ..................... 1-14 design and application of models reference adaptive control (mrac) on ball and beam muhammad zakiyullah romdlony, muhammad ridho rosa, edwin muhammad puji syamsudin, bambang riyanto trilaksono, agung surya wibowo............................................ 15-23 load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu louise indah utami, ika yuliyani, yanti suprianti, purwinda iriani ......................................... 24-35 improvement of power grid stability and load distribution using diesel excitation controller ehsan ganji, mehdi mahdavian .......................................................................................................... 36-47 design and kinematic analysis of a two-dof moving platform as a base for a car simulator bagus made arthaya, raymond christian, tua agustinus tamba, dilek bilgin tükel ............................................................................................................................................................... 48-59 state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system rizal nurdiansyah, novie ayub windarko, renny rakhmawati, muhammad abdul haq ............................................................................................................................................................... 60-71 fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology charlotha, roberth viktoria manurung , aminuddin debataraja, indra dwisaputra, subkhan, iqbal syamsu ......................................................................................................................... 72-78 two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises royke vincentius febriyana, ramadhan s. pernyata, dita andansari ..................................... 79-87 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 iii study on the production of hydrogen gas from water electrolysis on motorcycle engine zikri , aken derisman, muslim, wawan purwanto, al ichlas imran ........................................ 88-94 carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite zanu saputra, robeth viktoria manurung, aminuddin debataraja, muhammad iqbal nugraha, tien-fu lu ........................................................................................................................... 95-100 complete articles can be found at https://mev.lipi.go.id https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 1, 2022 iv abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. nur jamiludin ramadhan a, noval lilansa a, afaf fadhil rifa'i a, hoe dinh nguyen b (a department of manufacturing automation and mechatronics engineering bandung polytechnic for manufacturing, indonesia; b faculty of vehicle and energy engineering, phenikaa university, vietnam) pattern recognition based movement control and gripping forces control system on arm robot model using labview journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 1-14, 21 ill, 2 tab, 18 ref. most arm robot has an inefficient operating time because it requires operator to input destination coordinates. besides, main problem of arm robot is object’s vulnerability when it is manipulated by the robot. this research goals is to develop an arm robot control system which has ability to automatically detect object using image processing in order to reduce operating time. it is also able to control gripping force for eliminating damage to objects caused by robot gripper. this research is implemented in labview 2011 software to control arm robot model which can represent industrial scale robot. the software is designed with informative visualization to help user learn and understand robotic control concept deeply. the system can automatically detect object position based on pattern recognition method which has four steps: pre-processing process to initialize picture taken by camera, segmentation process for separating object from the background, classification process to determine characteristics of object, and position estimation process to estimate object position in the picture. the object’s position data are then calculated by using kinematic equation to control the robot’s motion. the results show that the system is able to detect object and move the robot automatically with accuracy rate in xaxis is 95.578 % and in y-axis is 92.878 %. the system also implements modified pi control method with fsr as input to control gripping force with maximum overshoot value <10 %. arm robot model control system developed is successfully meet the expectation. the system control can be implemented to industrial scale arm robot with several modification because of kinematic similarity between model and industrial scale robot. (author) keywords: arm robot model; labview based software; pattern recognition for position estimation; fsr based gripping force control. muhammad zakiyullah romdlony a, muhammad ridho rosa a, edwin muhammad puji syamsudin a, bambang riyanto trilaksono b, agung surya wibowo a, c (a school of electrical engineering, telkom university, indonesia; b school of electrical engineering and informatics, bandung institute of technology, indonesia; c department of electronics engineering, nscl laboratory, jeonbuk national university, south korea) design and application of models reference adaptive control (mrac) on ball and beam journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 15-23, 7 ill, 3 tab, 15 ref. this paper presents the implementation of an adaptive control approach to the ball and beam system (bbs). the dynamics of a bbs are non-linear, and in the implementation, the uncertainty of the system's parameters may occur. in this research, the linear statefeedback model reference adaptive control (mrac) is used to synchronize the states of the bbs with the states of the given reference model. this research investigates the performance of the mrac method for a linear system that is applied to a non-linear system or bbs. in order to get a faster states convergence response, we define the initial condition of the feedback gains. in addition, the feedback gains are limited to get less oscillation response. the results show the error convergence is improved for the different sets of the sinusoidal reference signal for the mrac with modified feedback gains. the ball position convergence improvement of mrac with modified feedback gains for sinusoidal reference with an amplitude of 0.25, 0.5, and 0.75 are 35.1 %, 36 %, and 52.4 %, respectively. (author) keywords: model reference adaptive control; modified feedback gains; ball and beam system. louise indah utami a, ika yuliyani a, yanti suprianti a, purwinda iriani a, b (a energy conversion engineering department, bandung state polytechnic, indonesia; b chemistry department, university of warwick, united journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 v kingdom) load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 24-35, 19 ill, 7 tab, 15 ref. combined cycle power plant (ccpp) is a closed-cycle power plant, where the heat from the gas turbine’s (gt) exhaust gas will be streamed to the heat recovery steam generator (hrsg) to be utilized by steam turbine (st). ccpp block 4 (jawa-2) pt indonesia power priok pomu has an installed capacity of 880 mw, consists of 2 gt units (301.5 mw each) and 1 st unit (307.5 mw). the performance of a power plant depends on its load, as the efficiency of the turbine generator is low when operated at low loads. the data as of july 2019 showed that 2.2.1 (2 gt, 2 hrsg, 1 st) configuration has been used in three conditions where the cc net load was around 30 – 45 %, which in fact could be compensated by the 1.1.1 (1 gt, 1 hrsg, 1 st) configuration. this resulted in a decrease of the cc net efficiency up to 21.34 %. the optimization that can be done is to change the load configuration from 2.2.1 to 1.1.1 at 0 – 50 % of cc net load through simulations, by including the influence of the gt and hrsg start-up processes. the result of this optimization is that the ccpp performance increases due to higher performance of each turbine generator. thus, the optimization results during july 2019 provided energy saving of 1,146.09 mmbtu or equivalent to cost saving of idr 152,249,551.76. (author) keywords: combined cycle; gas turbine; steam turbine; load optimization; power plant performance. ehsan ganji, mehdi mahdavian (department of computer engineering, king mongkut's university of technology thonburi, thailand) improvement of power grid stability and load distribution using diesel excitation controller journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 36-47, 18 ill, 4 tab, 21 ref. one of the requirements for controlling hybrid power systems is designing an appropriate excitation system, flexibility, protection, and coordination of all components to improve system stability. in this paper, various types of equipment simulated in the linear form and non-linear models are connected to the power supply. in the same direction, while presenting a new controller for the diesel generator excitation system and a filter used to purify and attenuate current harmonics is reported on the stability of a grid-independent system. finally, the variation of the mode for the voltage and power of the system has been confirmed at the time of error and complete system stability. also, the important indicators in the analysis are obtained in the lowest values, which can be seen from the controlled harmonics of the system of this data. in addition, the variation of the mode for the voltage and power of the system has been confirmed and the important indicators in the analysis are obtained in the lowest values. (author) keywords: hybrid power systems; improve system stability; non-linear control models; excitation system; load distribution. bagus made arthaya a, raymond christian b, tua agustinus tamba a, dilek bilgin tükel c (a mechatronics engineering department, faculty of industrial technology, parahyangan catholic university, indonesia; b faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia; c software engineering department, dogus university, turkey) design and kinematic analysis of a two-dof moving platform as a base for a car simulator journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 48-59, 13 ill, 0 tab, 25 ref. the study starts by modeling a simple 2-dof (degrees of freedom) moving platform that employs two actuators to provide two kinds of rotational motion on the moving platform and each motion is driven by an electrical motor. a preliminary study to better understand motion generation is conducted by deriving a mathematical model of the platform. based on this model, the relationship between the rotations of the two driving motors and the pitch and roll movements of the platform is determined. the range of movements must be limited both in the pitch and roll planes to a certain maximum and minimum values of tilting angles. this preliminary design of the platform is introduced to demonstrate motions that might be experienced by the user in roll and pitch directions. the motion generated has fulfilled the constraint with respect to the vestibular system. results of experimental works show that the first motor angle between -26° and 27° is suitable for the roll plane; meanwhile, the angles range of 52° and 54° for the second motor is suitable for the pitch plane. furthermore, some simple experiments were conducted to examine the correctness of the model through the comparison between testing results obtained from simulation and experimental work. in the reported results, the moving platform was set to some initial poses and was driven to the home position and the recording showed acceptable results. this moving platform can later be used for more comprehensive experiments, i.e., vehicle dynamic testing, driving training purposes, and human factor analyses. (author) keywords: human vestibular system; kinematic model; moving platform; pitch and roll planes; rotating encoder. rizal nurdiansyah a, novie ayub windarko a, renny rakhmawati a, muhammad abdul haq b (a electrical engineering department, politeknik elektronika negeri surabaya, indonesia; b department of electrical engineering and computer science, tokyo metropolitan university, japan) state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 60-71, 12 ill, 5 tab, 33 ref. ultracapacitors have been attracting interest to apply as energy storage devices with advantages of fast charging capability, high power density, and long lifecycle. as a storage device, accurate monitoring is required to ensure and operate safely during the charge/discharge process. therefore, high accuracy estimation of the state of charge (soc) is needed to keep the ultracapacitor working properly. this paper proposed soc estimation using the adaptive neuro-fuzzy inference system (anfis). the anfis is tested by comparing it to true soc based on an equivalent circuit model. to find the best method, the anfis is modified and tested with various membership functions of triangular, trapezoidal, and gaussian. the results show that triangular membership is the best journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi method due to its high accuracy. an experimental test is also conducted to verify simulation results. as an overall result, the triangular membership shows the best estimation. simulation results show soc estimation mean absolute percentage error (mape) is 0.70 % for charging and 0.83 % for discharging. furthermore, experimental results show that mape of soc estimation is 0.76 % for random current. the results of simulations and experimental tests show that anfis with a triangular membership function has the most reliable ability with a minimum error value in estimating the state of charge on the ultracapacitor even under conditions of indeterminate random current. (author) keywords: ultracapacitors; state of charge; adaptive neuro-fuzzy inference system; energy storage devices; equivalent circuit model. charlotha a, roberth viktoria manurung b, aminuddin debataraja c, indra dwisaputra a, subkhan d, iqbal syamsu b, e (a electrical and informatics department, politeknik manufaktur negeri bangka belitung, indonesia; b research center for telecommunication, national research and innovation agency (brin), indonesia; c electro engineering, politeknik negeri jakarta, indonesia; d mechanical engineering department, politeknik manufaktur negeri bangka belitung, indonesia; e institute of semiconductor technology (iht), laboratory for emerging nanometrology (lena), germany) fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 72-78, 9 ill, 1 tab, 26 ref. nitrate is one of the nutrients that can give an effect on the environment if it is applied in excess. it is also easily soluble in water and it has the potential to be a pollutant in groundwater by the over-process of fertilizer. therefore, it needs a detected component to give the right measure for nitrate in the soil, called a nitrate ion sensor. it consists of three electrodes configuration, namely, working, counter, and reference electrodes with conductive polyaniline doped with nitrate (no₃‾) which is fabricated by thick film technology. in previous research, acidic media was used as a solvent for polyaniline, while this research used water (h2o) solvent. the result of characterization showed that particles were distributed evenly on the sample with the form of particles being small balls with a dimension of 0.18 µm and the percentage of atomic elements being: 91.96 % carbon, 3.14 % nitrogen, and 4.9 % oxygen. the performance of sensors was investigated using potentiostat with four concentrations of nitrate standard solution. the result showed good response with a voltage range in each concentration of nitrate standard solution being 0.5002 volt (10 mg/l), 1.3552 volt (20 mg/l), 1.1208 volt (50 mg/l), and 0.8963 volt (100 mg/l). it was found that nitrate sensors with nitrate-doped conductive polymer, polyaniline, as the sensitive membrane responded well to detecting nitrate elements in precision farming and the sensitivity showed that for every 1 mg/l concentration in nitrate standard solution, the voltage increases by 0.0007. (author) keywords: electropolymerization process; performance of nitrate sensor; the polyaniline; thick-film technology. royke vincentius febriyana a, ramadhan s. pernyata a, dita andansari b (a product design department, samarinda state polytechnic (politeknik negeri samarinda), indonesia; b industrial design, razak faculty of technology and informatics, universiti teknologi malaysia, malaysia) two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 79-87, 14 ill, 4 tab, 23 ref. small and medium-sized enterprises (smes) have a big role in indonesian economic development. the government has set four strategies in an effort to boost indonesian economic development. one of the four strategies mentions the smes, and the other mentions the use of 4.0 technology. working capital has been the main issue need to be considered in the smes. thus, the affordability must be considered in the use of 4.0 technology in smes. one of the 4.0 technologies that are possible to be used in the smes is a three-axis milling machine. one of the limitations of the machine is that it cannot do the back-side machining process. the paper examines the possibility of manual back-side machining on the three-axis milling machine without adding a rotary axis. four methods were conducted by adding two-point markings on the x-axis, two-point markings on the y-axis, four-point markings on the xand y-axis, and four-point markings on the xand yaxis plus a series of offsetting processes. after conducting several qualitative observations and measurements on the mismatched position of the front and the back machining, and also analyzing the problems that emerged during the processes of the four different methods, it is concluded that adding four points markings on the xand y-axis plus doing a series of offsetting processes is the best method to have two-sided manual machining with three-axis computer numerical control (cnc) milling machine. (author) keywords: computer numerical control (cnc); small and medium-sized enterprises (smes); three-axis; two-sided machining. zikri a, aken derisman a, muslim b, wawan purwanto b, al ichlas imran c, d (a program studi mesin otomotif, universitas muhammadiyah riau, indonesia; b jurusan teknik otomotif, universitas negeri padang, indonesia; c mechanical engineering, national central university, taiwan; d jurusan teknik mesin, universitas halu oleo, indonesia) study on the production of hydrogen gas from water electrolysis on motorcycle engine journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 88-94, 8 ill, 2 tab, 19 ref. the primary emphasis of the research is on how to use hydrogen as an energy source for motorcycle fuel. this is an intriguing hypothesis to explore since, at the moment, fossil energy is used to meet fuel demands, although fossil energy supplies are running limited. as a result, hydrogen energy is an option that may be employed as a fuel substitute utilizing commercial water raw materials and the electrolysis method. the research goal is to demonstrate that electrolysis of water to hydrogen gas may occur while the vehicle is in use, to compute the amount of hydrogen gas generated, and to determine the time the vehicle can be utilized using the gas fuel created. the longterm goal of this study is to create a vehicle powered entirely by hydrogen gas produced by water electrolysis, particularly for motorcycles. the experimental approach was employed in this investigation, with three phases of testing on a carburetor-type motorbike utilizing 1, 2, and 3 liters of pertamax gasoline. the results demonstrated that the process of electrolysis of water into hydrogen gas on motorcycles is possible; however, the amount of gas journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii generated is still quite little. the hydrogen gas generated by this electrolysis method is only 0.06 bar when 1 liter of fuel is used, 0.42 bar when 2 liters of fuel are used, and 0.98 bar when 3 liters of fuel are used. (author) keywords: alternative fuel; water electrolysis; brown gas. zanu saputra a, robeth viktoria manurung b, aminuddin debataraja c, muhammad iqbal nugraha a, tien-fu lu d (a electrical engineering and informatics department, politeknik manufaktur negeri bangka belitung, indonesia; b research center for telecommunication, national research and innovation agency (brin), indonesia; c electrical engineering, state polytechnic of jakarta, indonesia; d mechanical engineering, the university of adelaide, australia) carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 1, p. 95-100, 6 ill, 1 tab, 38 ref. this paper concerns enhancing a lead detection sensor using a combination of polypyrrole (ppy), nafion (n), and ionic liquid (il) with thick-film or screen-printing technology on sensitive material-based carbon electrodes. electrode characterization using a scanning electron microscope (sem) was conducted to see the morphology of sensitive materials, showing that the spherical particles were distributed evenly on the electrode surface. analysis using energy dispersive spectroscopy (eds) shows that the element's atomic composition is 84.92 %, 8.81 %, 6.26 %, and 0.01 % for carbon, nitrogen, oxygen, and bismuth, respectively. potentiostat measurement with the ambient temperature of 25 °c on a standard lead solution with concentration ranging from 0.05 to 0.5 mg/l yields an average output voltage ranging from 2.16 to 2.27 v. it can be concluded that the sensor is able to detect lead with a sensitivity of 0.21 v in each addition of solution concentration (mg/l) and give an 84 % concentration contribution to the voltage. (author) keywords: lead detection; thick film; polypyrrole; nafion; ionic liquid. foreword from editor-in-chief list of contents mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.1-10 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: n. j. ramadhan et al., “five-axis parallel mechanism system (pms) cnc partial link control system based on modified inverse kinematic of 6-dof ups parallel manipulator,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 1-10, july 2023. five-axis parallel mechanism system (pms) cnc partial link control system based on modified inverse kinematic of 6-dof ups parallel manipulator nur jamiludin ramadhan a, *, indrawanto b, hoe dinh nguyen c a department of manufacturing automation and mechatronics engineering, bandung polytechnic for manufacturing kanayakan st. no. 21, dago, coblong, bandung, 40135, indonesia b faculty of mechanical and aerospace engineering, bandung institute of technology jalan ganesha 10, bandung 40132, indonesia c faculty of vehicle and energy engineering, phenikaa university p. nguyễn trác, yên nghĩa, hà đông, hà nội, vietnam received 10 march 2023; revised 4 april 2023; accepted 2 may 2023; published online 31 july 2023 abstract this paper presents a control system algorithm for a five-axis parallel mechanism system (pms) cnc milling machine based on a 6-dof stewart platform parallel manipulator with a universal-prismatic-spherical (ups) configuration. the control system reads the g-code commands as standard cnc machine language, then extract data points and interpolates them to generate the robot trajectory patterns as motion references. then, the control system uses the modified inverse kinematic equation to determine the length of each link to move the end effector to track the trajectory patterns from the previous gcode extraction process. the inverse kinematic equation is modified especially for the five-axis pms cnc milling machine by including machine-offset and tools-offset parameters so it will be easier for the control system to implement the kinematic equation. as expected, the system simulation results successfully followed the g-code program moving commands. the average error of the length control system is 0,1 mm, while the average error of the length change rate control system is 1,8 mm/s. the maximum error is 26.9 mm was caused by the system's inability to follow the motion profile in transient. it can be concluded that 6-dof stewart platform parallel structures, which provide better performance than serial structures, can be implemented as a new concept for the motion mechanism of five-axis cnc milling machines. the five-axis pms cnc milling machine also promises better performance than conventional five-axis gantry structures cnc. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: stewart platform; parallel manipulator; parallel mechanism structure; machine tools; cnc control system. i. introduction a robot with a parallel structure has a kinematic configuration with a closed chain type, meanings that each link is connected to the origin [1][2]. this configuration will give a better performance in the value of accuracy, acceleration at high speeds, and high stiffness [3] compared to the serial structure [4][5]. the advantages of the parallel robot make it possible to be implemented as a new concept for the five-axis cnc machine mechanism [6][7]. cnc machines generally use cantilever or gantry structures with some limitations due to their mechanical design [8]. in gantry structures each axis of a cnc machine is driven by one actuator, this structure requires a large power drive system, a highly precise control system, and a sturdy and large mechanical structure. cnc machine with a parallel robot motion mechanism (called parallel mechanism system cnc / pms cnc in this paper) could minimize some of these losses, this structure could minimize the movement of heavy structures [9][10][11]. fiveaxis pms cnc milling machine only moves motor spindle, in contrast the work pieces and machine table are static. whereas conventional five-axis gantry structures cnc has to move not only the motor spindle but also the machine table and the * corresponding author. tel: +62-812-2048-3148 e-mail address: nj_ramadhan@polman-bandung.ac.id https://dx.doi.org/10.14203/j.mev.2023.v14.1-10 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.1-10 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 2 work pieces. this will make five-axis pms cnc milling machine achieved higher speed and acceleration. it will also have higher accuracy, because the relative error of the actuator is distributed [12][13] and requires fewer static and dynamic components [14][15]. machine operating costs also become smaller due to lower energy consumption and higher feed speeds compared to conventional structure cnc machines [16]. a limitation to pms cnc machines is that they are less able to achieve the higher machining tolerances of conventional machine tools due to relative differences in structural rigidity and tool deflection and challenges associated with control algorithms [17][18][19], component miss-alignments and sensor capability [20][21][22]. a widely researched aspect of pms machine tools is in kinematic and dynamic modeling [23] also in improvements of pms implementation as machine tools for industrial applications. in the work of minh-nha pham et al. results show that the parameterized finite element model precisely predicts mode shapes and natural frequencies for several poses of the mobile platform. the accurate simulation model will be essential for optimizing the performance of the hexapod for machining tasks [24]. alesandro stabile et al. proposes boundary conditions on the isolation properties of parallel manipulators. it was shown that high-frequency performance cannot be achieved by the state-of-theart all-rotational joint systems and is achiveable by parallel mechanism systems [25]. the study done by barnfather, j. d et al. investigate how the widely researched robotic machining challenges to achievable tolerance ranges in real-world production and highlights achievable tolerances in low-cost robotic machining and opportunities for improvement, also providing a practical benchmark useful for process selection [26]. previous research shows that pms cnc is capable of handling previous machining tasks and is suitable to be implemented as a milling machine in the manufacturing process. however, no research and study implement this machine configuration in real cnc milling machining applications. the work reported in this paper is significantly focused on the development of a control system simulation of a five-axis pms cnc milling machine based on a 6-dof (degree of freedom) stewart platform parallel robot [27] which can read g-code command file as a standard cnc machine program. the control system reads the gcode commands then extract data points and interpolates them to generate the robot trajectory patterns as motion references. the control system then uses the modified inverse kinematic equation to determine the length of each link to move the end effector to track the trajectory patterns. system control response is analyzed from the simulation of linear motor actuator model with known parameter values from the previous research [27]. ii. materials and methods the five-axis pms cnc milling machine consists of a mechanical system and a motion control system specially engineered for controlling special parallel robot mechanism. the main component of the mechanical system is the stewart platform 6 ups parallel robot and the machine frames. robot motion is simulated in a 3d cartesian space coordinate system to show the ability of the robot to move as the cnc milling machine mechanism. general cnc machines motion control system cannot be used to control five-axis pms cnc milling machine because of the different mechanism. a special motion control system is engineered to be able to control parallel robot motion and also suitable for use as a cnc machine operation control. the control system reads the g-code data point and interpolates it to generate robot trajectory as references for robot motion patterns. then the control system uses an inverse kinematic equation to determine the length and calculate the difference of ink length for each interpolated point derived by time to determine the length change rate of each link. the cascade pi control method is implemented to control robot link length and link length change rate to move the end effector to track the trajectory. pi control was chosen because of the system’s need to speed up the settling and integral control to reduce the error rise time and the steady-state errors of the system. derivative components from the controller can create heavy instability and oscillation, so it is set to be very small close to zero or negligible because the milling machine's main control purpose is to reduce the steady-state errors of the system without causing risk of oscillation to ensure the processed work pieces are formed according to the g-code commands and does not have a wavy texture. a. parallel robot design stewart platform manipulator used in this study consists of a movable platform that is connected to a base through 6 feet. these legs have kinematics that is identical to the universal-prismatic-spherical (ups) configuration. the length of the prismatic manipulator will be controlled to perform platform movements. the stewart platform robot used in this research is previously developed at the bandung institute of technology at mechanical engineering laboratory [27]. the parallel robot is attached upside down on top of the cnc machine frame. figure 1 shows the 6 dof stewart platform robots used in this study. figure 1. design of 6-dof stewart platform (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 3 table 1 shows the kinematic specification of the parallel robot and it is illustrated in figure 2. the kinematic specification is a set of paramater of the parallel robots which specifically distinguish it from the others parallel robot. θp is the angle difference in joint position at parallel robot’s platform, while θb is the angle difference in joint position at the base. platform is term used to denote a moving part of parallel robot, while base is term used to denote a fixed static part. the parallel robot used in this study has 30° joint position at the platform and 20° joint positions at the base. to determine the position of joints, the angle variables is not enough, radius of joint position is also needed. rp is the radius of joint position at platform and rb is the radius of joint position at the base has to be determined. real robot actuator is limited in stroke length. there is robot movements limitations according to link’s possible length which is noted by li notation. b. inverse kinematics equation calcutating platform displacement as a function of changes in actuator length is illustrated clearly in figure 3. the origin coordinate system bxyz is attached to the center of the base and the origin coordinates txyz are located at the center of the moving platform. points bi represents the joint position at the base while ti represents the joint position at the moving platforms. these joints are placed on the base and the moving platform with an angle of separation between the points (t2 and t3, t4 and t5, t1 and t6) denoted by θp as shown in figure 3(b). in the same way, the angle of separation between points (b1 and b2, b3 and b4, b5 and b6) is table 1. kinematic specification parameter unit θp 30° θb 20° rp 170 mm rb 350 mm li 490 – 740 mm (a) (b) figure 2. kinematic specification illustration of (a) base; (b) platform (source: personal collection) figure 3. stewart platform kinematics diagram: (a) full system; (b) platform only (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 4 denoted by θb. from figure 3(b), the location of the joints marked with a point ti on the moving platform can be found in the equation (1). rp is the radius of joint position at the moving platform while rb is the radius of joint position at base platforms. using the same approach, the location of the point marked with the point (bi) on the base platform can be obtained from the equation (2). the general equation of each joint platform follow this equations. 𝑇𝑖 = � 𝑇𝑥𝑖 𝑇𝑦𝑖 𝑇𝑧𝑖 � = � 𝑟𝑝 cos(𝜆𝑖) 𝑟𝑝 sin(𝜆𝑖) 0 �� 𝜆𝑖 = 𝑖 𝜋 3 + 𝜃𝑝 2 ; 𝑖 = 1,3,5 𝜆𝑖 = 𝜆𝑖−1 + 𝜃𝑝 ; 𝑖 = 2,4,6 (1) 𝐵𝑖 = � 𝐵𝑥𝑖 𝐵𝑦𝑖 𝐵𝑧𝑖 � = � 𝑟𝑝 cos(λ𝑖) 𝑟𝑝 sin(λ𝑖) 0 �� λ𝑖 = 𝑖 𝜋 3 + 𝜃𝑏 2 ; 𝑖 = 1,3,5 λ𝑖 = 𝜆𝑖−1 + 𝜃𝑏 ; 𝑖 = 2,4,6 (2) the position of the end-effector can be represented by the position vector, p equation (3) while the orientation is represented by the rotation matrix rbt equation (4). the rotation matrix is determined by the roll, pitch, and yaw angles, namely rotation on the x-axis, noted by rx(α), followed by rotation on the y-axis, ry(β), and rotation, namely rotation on the z-axis, rz(γ). in this way, the rotation matrix of the moving platform corresponding to the base platform coordinate system is obtained. the position vector p represents the displacement vector from the moving platform to the base. so, the rotation matrix and the position vector are described in equation (3) to equation (13), 𝑃 = � 𝑃𝑥 𝑃𝑦 𝑃𝑧 � (3) 𝑅𝑇𝐵 = 𝑅𝑍(𝛾). 𝑅𝑌(𝛽). 𝑅𝑋(𝛼) = � 𝑟11 𝑟12 𝑟13 𝑟21 𝑟22 𝑟23 𝑟31 𝑟32 𝑟33 � (4) 𝑟11 = cos(𝛽) . cos(𝛾) (5) 𝑟12 = sin(𝛼) . cos(𝛽) . cos(𝛾) − cos(𝛼) . sin(𝛾) (6) 𝑟13 = sin(𝛼) . sin(𝛾) + cos(𝛼) . sin(𝛽) . cos(𝛾) (7) 𝑟21 = cos(𝛽) . sin(𝛾) (8) 𝑟22 = cos(𝛼) . cos(𝛽) + sin(𝛼) . sin(𝛽) . sin(𝛾) (9) 𝑟23 = cos(𝛼) . sin(𝛽) . sin(𝛾) − sin(𝛼) . cos(𝛾) (10) 𝑟31 = − sin(𝛽) (11) 𝑟32 = sin(𝛼) . cos(𝛽) (12) 𝑟33 = cos(𝛼) . sin(𝛽) (13) the length of each link matrix noted by notation li can be determined by equation (14), 𝐿𝑖 = 𝑅𝑋𝑌𝑍. 𝑇𝑖 + 𝑃 − 𝐵𝑖 (14) because the robot base is attached to the top of the machine frame, it is simpler to define the machine offset parameter equal to the distance of the machine origin position to the robot base (noted by notation m). then, because of the spindle and cutting tool attached to the platform, the endeffector position and orientation will be moved to the end point of the cutting tool. the equation is then modified by adding the cutting tool offset (noted by notation c) parameter to the previous equation. the equation to determine the matrix of link’s length li is modified as shown in equation (15). remember that li is vector in the cartexian space and cannot be used for actuator control system set point. it is needed to determine the magnitude length of each link by simply calculate each link using equation (16), 𝐿𝑖 = 𝑅𝑋𝑌𝑍. 𝑇𝑖 + 𝑃 + 𝑅𝑋𝑌𝑍. 𝐶 − 𝐵𝑖 − 𝑀 (15) 𝑙𝑖 = ‖𝐿𝑖‖ (16) c. partial link control method by considering the characteristics of the component used in the control system, it can be seen that both the linear potentiometer sensor component and the linear actuator component have linear characteristics. the application of conventional control algorithms is very suitable to be applied to systems with linear characteristics, considering the ease of application. the control system design is depicted in the main control system block diagram shown in figure 4. the block diagram of the control system applies to controlling the movement of each linear actuator simultaneously. each actuator is controlled by the same control algorithm but gets a different input motion profile depending on the position set-point and speed set-point that must be achieved. figure 5 shows the control system block diagram for each figure 4. main control system block diagram (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 5 actuator. dc motor mathematical model can be written with equation (17), �̇� 𝑉 = 𝐾𝑡 (𝐽𝑚.𝐿𝑎)𝑠2+(𝐿𝑎.𝐵𝑚+𝑅𝑎.𝐽𝑚)𝑠+(𝐾𝑡.𝐾𝑣+𝐵𝑚.𝑅𝑎) . 𝑟𝑏𝑠 (17) system identification is carried out on the system output by performing inverse laplace calculations on the system's mathematical model so that the parameter values are obtained [27]. dc motor armature resistivity is noted by ra is equal to 2.78 ω, it’s inductance is noted by la is equal to 7.48 mh. dc motor mechanical properties such as friction, inertia and ball-screw radius are respectively noted as bm, , jm and rbs, are equal to 24.8 x 10 -3 , 1.067 x 10-3 kg.m2, and 1.18 x 10-3 m. motor torque constant and motor velocity constant are respectively noted as kt and kv both are equals to 0.896. d. machine control application the machine control application algorithm is divided into the g-code point interpolation algorithm and the control system algorithm. in general, the algorithm can be depicted in the flow chart in figure 6. the machine control application program starts by reading g-code file which is standard file for cnc command. g-code is the most widely used computer numerical control (cnc) programming language. it is used mainly in computer-aided manufacturing to control automated machine tools, as well as from a 3dprinting slicer app. g-code instructions are provided to a machine controller (industrial computer) that tells the motors where to move, how fast to move, and what path to follow. data from g-code file will be parsed and extracted as set-point coordinate and machine control variables that will be evaluated to determine interpolation algorithm type used for calculating and generating interpolated points refer to set-point coordinate. g-code reader application program is operated from user interface by the operator. any interpolated point will be displayed in a user-friendly 3d graph to show the machine motion simulation. the g-code reader application user interface algorithm is shown in figure 7. the g-code interpolation program will extract data from the g-code command and evaluate the validity before execution. this process is done in an execution loop function in the application software while user interface function is opened and machine run condition is executed by the operator from the application software interface. the g-code extraction loop algorithm is shown in figure 8. the g-code interpolation program can be run on any computer to validate the g-code program and interpolate to machine movements. regarding the process of g-code validation, there are several algorithms including the calculation of modified inverse kinematic and actuator limiter algorithms for avoiding each actuator that exceeds the maximum length and maximum speed limit capability. the validity evaluation algorithm is shown in figure 9. after the inverse kinematic formula is modified with the addition of machine offset and tool offset parameters according to machine conditions, then figure 5. partial link control system block diagram (source: personal collection) figure 6. pms cnc control system algorithm (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 6 the area that can be reached by the pms cnc machine can be determined and called workspace area. in this research, the workspace area is not defined by the forward kinematic calculations, and forward kinematics will be done in further research. the workspace area on this pms cnc machine is determined by iterating the inverse kinematic calculation with the position input value constantly changing from the minimum value to the maximum value on each axis of motion. the input point that produces the length value of each actuator that is within the range of the actuator's capability, which is between 490 mm to 740 mm will be included in the workspace area data set. workspace area data set is a two dimension array representing all reachable points in the x, y, and z-axis. to produce the desired robot movement, the six linear actuators must move simultaneously with different length change rate set-points until the length set-point of each actuator is reached according to the kinematics calculation results in the same period. to avoid the movement chaos caused by the actuator limitation, a set-point limit for the allowable length change rate is made. if the result of translating g-code calculation and inverse kinematics produces one or more set-point that exceeds the limit of the actuator's capability, then the g-code will not be validated. iii. results and discussions in this chapter, we discuss the result of the fiveaxis pms cnc control system simulation to follow a simple g-code containing linear movements which follow straight line trajectories and corner movements, both generate a 150 mm square-shaped trajectory. based on the g-code program used for testing (illustration shown in figure 10), the machine will move rapidly from the origin position (0, 0, 500) to point (0, 0, 200), then the machine will move rapidly from point (0, 0, 200) to point (-75, -75, 200), then the linear interpolation movement to the point (-75, 75, 200), then linear interpolation movement to the point (75, 75, 200), then to the point (75, -75, 200), then to the point (-75, -75, 200), figure 7. g-code reader user interface algorithm (source: personal collection) figure 8. g-code extraction loop algorithm (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 7 after that it moves rapidly to the point (0, 0, 200), the last move back to the initial point (0, 0, 500). for each step, there will be a start position and finish position which is acquired from g-code data extraction, trajectory line from the start position to the finish position is linear pah but will become a non-linear set-point motion at the actuator. to minimize the complexity of non-linear control system calculation, while still ensuring the motion follow the trajectory linear path, the system will interpolate the linear trajectory linear path to generate points that become new starting and finish points with higher resolution. figure 11 shows the system response and error of the control system for linear actuator 1. figure 11(a) show that to follow the desired simple square trajectory, the linear actuator 1 has to lengthen from it’s initial length 500 mm become 560 mm gradually. after that it will lengthen again to reach 590 mm length, 605 mm and so on. it will follow some certain length in motion profile which is generated by interpolation and inverse kinematic algorithm. figure 11(b) shows the control error value calculated from the difference between desired length with actual length read from the sensor. the error is relatively large because of the actuator 1 inability to move faster to follows the motion profile set-point. it's length change rate is slow compared to the length set-point change rate in the desired motion profile. the average of the actuator 1 length error is 0.8 mm. figure 12 shows the system response and the error of the control system for linear actuator 2. figure 12(a) shows similar graph with figure 11(a). it shows linear actuator 2 lengthens from it’s initial length 500 mm to become 560 mm gradually. after that it will shorten to reach 525 mm length, and then lengthen again to reach 570 mm and so on. similar with previous actuator, it also follow certain length set-point in motion profile specified for linear actuator 2 which is generated by interpolation and inverse kinematic algorithm. figure 12(b) shows the control error value calculated from the difference between desired length with actual length read from the sensor of linear actuator 2. it is similar to actuator 1 that the error is relatively large because of the actuator 2 inability to move faster to follow the desired length change rate. the average of the actuator 2 length error is -0.7 mm. figure 9. g-code extraction and validation algorithm (source: personal collection) figure 10. testing step illustration (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 8 figure 11. actuator 1: (a) control response of linear; (b) control error (source: personal collection) figure 12. actuator 2: (a) control response; (b) control error (source: personal collection) n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 9 it is similar to the previous actuator, error is relatively large for actuator 3, actuator 4, actuator 5, and actuator 6 because of the actuators inability to move faster to follow the desired length change rate. the average of the actuator 3, actuator 4, actuator 5, and actuator 6 length error respectively is -0.7 mm, 0.9 mm, 0.7 mm, and -0.3 mm. all the actuator responses shows the same phenomenon, all linear actuator successfully follow the desired length in steady-state condition at the end, but the system response at transient condition is poor. this is happens because the desired length change rate for all actuators is relatively the same while the actuator specification for all actuators especially the length change rate is limited and could not follow the length change rate in desired motion profile. iv. conclusion th is study successfully implements a simulation of five-axis pms cnc milling machine configuration in real cnc milling machining applications by reading and extracting g-code command as machine motion control set-point. the average actuator length error for linear actuator 1, linear actuator 2, linear actuator 3, linear actuator 4, linear actuator 5, and linear actuator 6 in a row is 0.8 mm, -0.7 mm, -0.7 mm, 0.9 mm, 0.7 mm, -0.3 mm. the average length control system error = 0,1 mm, while the average length change rate control system = 1,8 mm/s. the result is quite good but still can cause large errors in real-world coordinates. the smallest error is obtained when the system is in a steadystate. however, in transient state the largest error reaches 26.9 mm. the root cause of the error is the system's inability to follow the motion profile. the length change rate response of all actuator is slow compared to the length set-point change rate in desired motion profile. it can be concludes that 6dof stewart platform parallel robot structures which provide better performance than serial robot structures can be implemented as a new concept for the motion mechanism of five-axis cnc milling machines which is commonly used only for pick and place applications. the five-axis pms cnc milling machine also promises better performance than conventional five-axis gantry structures cnc. a lot of work is needed to improve machine performance. begin with the mechanical aspect by ensuring machine components are installed properly to minimize backlash, as well as the robot structure, is measured with high accuracy so that the accuracy of kinematic calculations increases. other aspects are improvements and development of linear and circular interpolation algorithms, research and exploration of a method to produce an optimal motion profile that is suitable for the system and actuator specification is also needed, there is also a need for research of the control algorithms that is not limited to conventional control but also explorable for non-linear control system based on the dynamics of the robot. system testing also needs to be carried out in 3d coordinate space with a more complicated g-code program that can represent the movement of the five-axis cnc machine. acknowledgements this research was done in the manufacturing laboratory, department of mechanical and aerospace engineering, bandung institute of technology. this research was supported by the department of manufacturing automation and mechatronics engineering, bandung polytechnic for manufacturing. this paper would not have been possible without the exceptional support of my wife muntaha habibatu rahma and my colleagues at bandung institute of technology, ahshonat khoirunnisa, reka ardhi prayoga, and indra agung, also support from mr. ahmad iskandar and mr. hafidz. declarations author contribution n.j. ramadhan: writing -original draft, writing review & editing, conceptualization, formal analysis, investigation, resources, visualization. indrawanto: conceptualization, formal analysis, investigation, supervision. h.d. nguyen: writing -review & editing, resources, visualization, supervision. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] ratiu, m. & anton, d. m., “a brief overview of parallel robots and parallel kinematic machines,” materials science and engineering. 898. 012007, 2020. [2] yi, j., qingqing, h., zhaoen, d. et al., “structural design and kinematic analysis of a welding robot for liquefied natural gas membrane tank automatic welding,” int j adv manuf technol, 122, 461–474, 2022. [3] nzue, r., brethé, j., et al. comparison of serial and parallel robot repeatability based on different performance criteria,” mechanism and machine theory, 61, 136-155, 2013. [4] nguyen vu, l., & kuo, c., “an analytical stiffness method for spring-articulated planar serial or quasi-serial manipulators under gravity and an arbitrary load,” mechanism and machine theory, 137, 108-126, 2019. [5] ramadhan, n. j., lilansa, n., rifa'i, a., & nguyen dinh, h., “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” journal of mechatronics, electrical power, and vehicular technology, 13(1), 1-14, 2022. [6] darvekar, s., koteswara rao, a., & shankar ganesh, s., “machining capability of a 2-d of parallel kinematic machine tool and conventional cnc milling machine,” materials today: proceedings, 45, 3213-3218, 2021. [7] stepanenko, o., bonev ilian, a., & zlatanov, d., “a new 4-dof fully parallel robot with decoupled rotation for five-axis https://mev.lipi.go.id/ https://doi.org/10.1088/1757-899x/898/1/012007 https://doi.org/10.1088/1757-899x/898/1/012007 https://doi.org/10.1088/1757-899x/898/1/012007 https://doi.org/10.1007/s00170-022-09861-2 https://doi.org/10.1007/s00170-022-09861-2 https://doi.org/10.1007/s00170-022-09861-2 https://doi.org/10.1007/s00170-022-09861-2 https://doi.org/10.1016/j.mechmachtheory.2012.10.004 https://doi.org/10.1016/j.mechmachtheory.2012.10.004 https://doi.org/10.1016/j.mechmachtheory.2012.10.004 https://doi.org/10.1016/j.mechmachtheory.2019.03.015 https://doi.org/10.1016/j.mechmachtheory.2019.03.015 https://doi.org/10.1016/j.mechmachtheory.2019.03.015 https://doi.org/10.1016/j.mechmachtheory.2019.03.015 https://doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.1016/j.matpr.2020.12.376 https://doi.org/10.1016/j.matpr.2020.12.376 https://doi.org/10.1016/j.matpr.2020.12.376 https://doi.org/10.1016/j.matpr.2020.12.376 https://doi.org/10.1115/1.4042849 https://doi.org/10.1115/1.4042849 n.j. ramadhan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 1-10 10 micromachining applications,” asme. j. mechanisms robotics, june 2019; 11(3): 031010, 2019. [8] fu, r., jin, y., et al., “review on structure-based errors of parallel kinematic machines in comparison with traditional nc machines,” springer comm comp inf sci, 923, 2018. [9] verl, a., valente, a., melkote, s., brecher, c., ozturk, e., & tunc, l. t.,” robots in machining. cirp annals, 68(2), 799-822, 2019. [10] wang, w., wang, n., & wu, x., “kinematics and dynamics analysis of a six-degree of freedom parallel manipulator,” international journal of advanced robotic systems, 2022. [11] zhao, y., & gao, f., “ inverse dynamics of the 6-dof out-parallel manipulator by means of the principle of virtual work”, robotica, 27(2), 259-268, 2009. [12] cao, w., ding, h., & zhu, w., “stiffness modeling of overconstrained parallel mechanisms under considering gravity and external payloads,” mechanism and machine theory, 135, 1-16, 2019. [13] yang, d., xie, f. & liu, x., “velocity constraints based approach for online trajectory planning of high-speed parallel robots,” chin. j. mech. eng., 35, 127, 2022. [14] lin, j., qi, c., gao, f., yue, y., hu, y., & wei, b., “modeling and verification for a 3-dof flexure-based planar parallel micromanipulator,” asme. j. mechanisms robotics, 2022. [15] chen, g., rui, x., abbas, l. k., wang, g., yang, f., & zhu, w., “a novel method for the dynamic modeling of stewart parallel mechanism,” mechanism and machine theory, 126, 397-412, 2018. [16] brinker, j., corves, b., & takeda, y., “kinematic performance evaluation of high-speed delta parallel robots based on motion/force transmission indices,” mechanism and machine theory, 125, 111-125, 2018. [17] velasco, j., barambones, ó., calvo, i., venegas, p., & napole, c. m., “validation of a stewart platform inspection system with an artificial neural network controller,” precision engineering, 74, 369-381, 2022. [18] xi, f., moosavian, a., et al., “analysis and control of an actuation-redundant parallel mechanism requiring synchronization,” asme. j. mech. rob., 12(4), 044501, 2020. [19] xu, l., chai, x., et al., “design and experimental investigation of a new 2r1t overconstrained parallel kinematic machine with actuation redundancy,” asme j. mech. rob., 11(3), 031016, 2019. [20] silva, d., garrido, j., & riveiro, e., “stewart platform motion control automation with industrial resources to perform cycloidal and oceanic wave trajectories. machines,” 10(8), 711, 2022. [21] jin, x., jung, j., ko, s., choi, e., park, j.-o., & kim, c.-s., “geometric parameter calibration for a cable-driven parallel robot based on a single one-dimensional laser distance sensor measurement and experimental modeling, sensors, 18(7), 2392, 2018. [22] bilal, d. k., unel, m., tunc, l. t., & gonul, b., “development of a vision based pose estimation system for robotic machining and improving its accuracy using lstm neural networks and sparse regression,” robotics and computer-integrated manufacturing, 74, 102262, 2022. [23] danaei, b., arian, a., masouleh, m.t., kalhor, a., “kinematic and dynamic modeling and base inertial parameters determination of the quadrupteron parallel manipulator,” computational kinematics, mechanisms and machine science, vol 50. springer, cham, 2018. [24] pham, m., champliaud, h., liu, z., & bonev, i. a., “parameterized finite element modeling and experimental modal testing for vibration analysis of an industrial hexapod for machining,” mechanism and machine theory, 167, 104502, 2022. [25] stabile, a., yotov, v. v., aglietti, g. s., de francesco, p., & richardson, g., “effect of boundary conditions on a highperformance isolation hexapod platform,” mechanism and machine theory, 177, 105020, 2022. [26] barnfather, j.d., goodfellow, m.j. & abram, t., “achievable tolerances in robotic feature machining operations using a low-cost hexapod,” int j adv manuf technol, 95, 1421–1436, 2018. [27] indrawanto & anindito, s., “design and control of the stewart platform robot,” third asia international conference on modelling & simulation, 475-480, 2009. https://doi.org/10.1115/1.4042849 https://doi.org/10.1115/1.4042849 https://doi.org/10.1007/978-981-13-2396-6_23 https://doi.org/10.1007/978-981-13-2396-6_23 https://doi.org/10.1007/978-981-13-2396-6_23 https://doi.org/10.1016/j.cirp.2019.05.009 https://doi.org/10.1016/j.cirp.2019.05.009 https://doi.org/10.1177/17298806221132077 https://doi.org/10.1177/17298806221132077 https://doi.org/10.1177/17298806221132077 https://doi.org/10.1017/s0263574708004657 https://doi.org/10.1017/s0263574708004657 https://doi.org/10.1017/s0263574708004657 https://doi.org/10.1016/j.mechmachtheory.2018.12.031 https://doi.org/10.1016/j.mechmachtheory.2018.12.031 https://doi.org/10.1016/j.mechmachtheory.2018.12.031 https://doi.org/10.1016/j.mechmachtheory.2018.12.031 https://doi.org/10.1186/s10033-022-00800-6 https://doi.org/10.1186/s10033-022-00800-6 https://doi.org/10.1186/s10033-022-00800-6 https://doi.org/10.1115/1.4055165 https://doi.org/10.1115/1.4055165 https://doi.org/10.1115/1.4055165 https://doi.org/10.1016/j.mechmachtheory.2018.04.024 https://doi.org/10.1016/j.mechmachtheory.2018.04.024 https://doi.org/10.1016/j.mechmachtheory.2018.04.024 https://doi.org/10.1016/j.mechmachtheory.2018.04.024 https://doi.org/10.1016/j.mechmachtheory.2017.11.029 https://doi.org/10.1016/j.mechmachtheory.2017.11.029 https://doi.org/10.1016/j.mechmachtheory.2017.11.029 https://doi.org/10.1016/j.mechmachtheory.2017.11.029 https://doi.org/10.1016/j.precisioneng.2022.01.002 https://doi.org/10.1016/j.precisioneng.2022.01.002 https://doi.org/10.1016/j.precisioneng.2022.01.002 https://doi.org/10.1016/j.precisioneng.2022.01.002 https://doi.org/10.1115/1.4045653 https://doi.org/10.1115/1.4045653 https://doi.org/10.1115/1.4045653 https://dx.doi.org/10.1115/1.4042628 https://dx.doi.org/10.1115/1.4042628 https://dx.doi.org/10.1115/1.4042628 https://dx.doi.org/10.1115/1.4042628 https://doi.org/10.3390/machines10080711 https://doi.org/10.3390/machines10080711 https://doi.org/10.3390/machines10080711 https://doi.org/10.3390/machines10080711 https://doi.org/10.3390%2fs18072392 https://doi.org/10.3390%2fs18072392 https://doi.org/10.3390%2fs18072392 https://doi.org/10.3390%2fs18072392 https://doi.org/10.3390%2fs18072392 https://doi.org/10.1016/j.rcim.2021.102262 https://doi.org/10.1016/j.rcim.2021.102262 https://doi.org/10.1016/j.rcim.2021.102262 https://doi.org/10.1016/j.rcim.2021.102262 https://doi.org/10.1016/j.rcim.2021.102262 https://doi.org/10.1007/978-3-319-60867-9_28 https://doi.org/10.1007/978-3-319-60867-9_28 https://doi.org/10.1007/978-3-319-60867-9_28 https://doi.org/10.1007/978-3-319-60867-9_28 https://doi.org/10.1007/978-3-319-60867-9_28 https://doi.org/10.1016/j.mechmachtheory.2021.104502 https://doi.org/10.1016/j.mechmachtheory.2021.104502 https://doi.org/10.1016/j.mechmachtheory.2021.104502 https://doi.org/10.1016/j.mechmachtheory.2021.104502 https://doi.org/10.1016/j.mechmachtheory.2021.104502 https://doi.org/10.1016/j.mechmachtheory.2022.105020 https://doi.org/10.1016/j.mechmachtheory.2022.105020 https://doi.org/10.1016/j.mechmachtheory.2022.105020 https://doi.org/10.1016/j.mechmachtheory.2022.105020 https://doi.org/10.1007/s00170-017-1266-1 https://doi.org/10.1007/s00170-017-1266-1 https://doi.org/10.1007/s00170-017-1266-1 https://doi.org/10.1007/s00170-017-1266-1 https://doi.org/10.1109/ams.2009.53 https://doi.org/10.1109/ams.2009.53 https://doi.org/10.1109/ams.2009.53 introduction ii. materials and methods a. parallel robot design b. inverse kinematics equation c. partial link control method d. machine control application iii. results and discussions iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.103-110 analysis and development of walking algorithm kinematic model for 5-degree of freedom bipedal robot analisis dan pengembangan model kinematik algoritma berjalan untuk 5-derajat kebebasan bipedal robot gerald wahyudi setiono a, prianggada indra tanaya b, *, henricus riyanto hendradji a a department of mechatronics engineering, swiss german university edutown bsdcity, tangerang, indonesia b department of industrial engineering, swiss german university edutown bsdcity, tangerang, indonesia received 12 july 2012; received in revised form 7 november 2012; accepted 12 november 2012 published online 18 december 2012 abstract a design of walking diagram and the calculation of a bipedal robot have been developed. the bipedal robot was designed and constructed with several kinds of servo bracket for the legs, two feet and a hip. each of the bipedal robot leg was 5-degrees of freedom, three pitches (hip joint, knee joint and ankle joint) and two rolls (hip joint and ankle joint). the walking algorithm of this bipedal robot was based on the triangle formulation of cosine law to get the angle value at each joint. the hip height, height of the swinging leg and the step distance are derived based on linear equation. this paper discussed the kinematic model analysis and the development of the walking diagram of the bipedal robot. kinematics equations were derived, the joint angles were simulated and coded into arduino board to be executed to the robot. key words: bipedal robot, kinematics model, kinematics analysis, 5-degree of freedom, walking algorithm. abstrak makalah ini merupakan pengembangan desain untuk algoritma berjalan dan kalkulasi bipedal robot. dalam hal ini, bipedal robot didesain dan dikonstruksi dengan bagian pinggul, telapak kaki dan beberapa jenis dudukan servo untuk kakinya. setiap kaki terdiri dari 5-derajat kebebasan, 3 pitch (engsel pinggul, lutut dan engkel) dan dua roll (sendi pinggul dan engkel). algoritma berjalan untuk nilai sudut tiap engsel dari bipedal robot ini berdasarkan formula cosinus dan sinus dari segitiga. tinggi hip, tinggi kaki yang diayun dan jarak tempuh melangkah diturunkan berdasarkan persamaan linear. makalah ini akan mendiskusikan analisis model kinematik dan pengembangan diagram berjalan dari bipedal robot. persamaan kinematika diturunkan, sudut-sudut joint disimulasikan dan diubah kedalam kode program untuk dieksekusikan pada robot, menggunakan arduino board. kata kunci: bipedal robot, model kinematik, analisis kinematik, 5-derajat kebebasan, algoritma berjalan. i. introduction bipedal robot has been developed since many years because of the unique algorithm of humanmimicking walking motion. the development of the bipedal robot has the purpose of approaching the most similar walking algorithm as a human being. the walking algorithm of a human is not limited to one type of walking algorithm but it is vary. “bipedalism is a manner of moving on land, where the organism progresses using only its two rear limbs, or legs” [2]. bipedal robot means a robot that consists of two feet and since it only has two feet, it is able to move almost freely just like a human being by walking, running or hopping. bipedal robot has a very complex mathematical calculation in order to find the perfect formula to make the bipedal robot stand still. “dany walker” [3] is another example of a bipedal robot model where each leg has three joints and five degrees of freedom. each degree of freedom consists of a motor as its actuator, which is servo motor. the material used for the * corresponding author. tel: +62-21-30450045 e-mail: prianggada.itanaya@sgu.ac.id http://dx.doi.org/10.14203/j.mev.2012.v3.103-110 g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 104 bipedal robot is normally aluminum since it is light and strong. bipedal robot “archer 32” [4] uses aluminum for the legs, feet and the hip to avoid the heavy weight because bipedal robot only consists of two legs and it is required to have a high mobility. this bipedal robot has a balancer on its hip part and it helps to maintain the balance of the bipedal robot. the movement of the balancer is only in one axis, left or right, and is moved by a servo motor. trajectory planning in bipedal robot [5, 6] is normally consists of starting stride, full stride and ending stride. in order to make the bipedal robot walks, full stride is repeated more than once. in walking motion, either starting, full or ending stride, the bipedal robot always lifts one of its leg before swings it forward, not drag it in order to approach the way of human walks. trajectory planning of a bipedal robot also consists of two phase, single phase where one leg supports the whole weight of the bipedal robot, and double phase where two legs support the whole weight of the bipedal robot. other bipedal robot use zero moment point regulation for the walking control [7-9] and inverted pendulum system for the stabilization of walking [10, 11]. there are also the analysis of both zero moment point gait and limit-cycle walking gait for bipedal robot [12], mechanical energy balance [13] and human’s gait pattern analysis [14]. in this paper, the desired walking algorithm of the bipedal robot will be based on the kinematic model. the process of the walking will not form a straight line but a triangle instead. figure 1 shows the bipedal robot developed at our institution [1]. the equations to obtain the variable values are derived based on the connection of each variable by using a linear equation and the triangle formulation. this paper analyze the movement of the bipedal robot based on derived kinematics equation from 2 dimensional point of view. the result of kinematics analysis then is used as parameter within a program to be executed using arduino board [1, 15]. during the analysis, the roll movement is assumed to be static. the program execution on arduino board is beyond the discussion of this paper. ii. bipedal robot walking diagram at our institution, a bipedal robot has been constructed and developed. the bipedal robot height while the leg on a straight condition is 380mm. the bipedal robot torso’s width is 160mm. the minimum bipedal robot height on squat condition is 220mm. the graph and the formula discussed in this article are based on our result [1]. there will be three types of motion for the walking diagram of the bipedal robot, starting motion, full motion and ending motion. starting motion is the beginning of the walking motion of the bipedal robot by lifting one of the leg forward until it touches the ground, then followed by the other leg, which is lagged behind, swings forward until the position of the reference lines are on the same vertical line position. full motion is the continuation of the walking algorithm for the bipedal robot, where this motion can be repeated as many as required. the sequence will always be the same, by changing the leg that swings forward and lifted at the end of the full motion. the last is ending motion, which to end the motion of the bipedal robot by letting both of the legs stand on the ground where the reference lines are on the same vertical line position at the end of the motion. a. starting motion figure 2 is the starting motion diagram, which is also the initial movement of the bipedal robot to take its first step. the bipedal robot will lift the foot and not drag the foot forward in order to approach the human nature in walking. it lifts the foot with a certain height and swings it forward until a certain distance forward achieved then the foot comes back down and touches the ground. from figure 2, after the red leg reaches a certain distance forward and the foot touches the ground, then the bipedal robot lifts the other leg,which is the black leg with a certain height then it swings the foot forward until the reference line of the black leg reaches the position of the reference line of the red leg. at the end of the starting motion, both of the reference lines will be on the same vertical line position but the black leg’s foot is lifted as high as a requested height of swinging leg h. figure 1. bipedal robot [1]: cad model and the constructed system. g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 105 as the red leg position leads the black leg and the foot of the red leg touches the ground, there are degree formed between the reference line of the red leg and the black leg because of the difference in position between hh1 and hh2. b. full motion figure 3 is the full motion diagram for the bipedal robot, which is the next motion after the starting motion. in the starting motion, the leg that is lifted at the end of the motion is the black leg. in the beginning of the full motion (based on the diagram) black leg is lifted (which is from the previous motion) as high as the requested height of swinging leg then it continues to swing forward until requested step distance reached and the foot touches the ground and the angle value between the reference lines reaches maximum value. then the red leg will swing forward until both of the reference lines are on the same vertical line position with the red leg lifted as high as the requested height. this full motion can be repeated as many as requested and the sequence will always be the same but with different leg lifted at the beginning of the motion. after the requested full motion fulfilled, the motion continues to the ending motion. c. ending motion figure 4 is the ending motion diagram of the bipedal robot, begins (based on the ending motion diagram) with the red leg lifted as high as the requested height then swings forward until requested step distance, foot touches the ground and the angle value between reference line reaches maximum value. then the black leg swings forward until it reaches as high as half of the requested height then goes back down. in the end of the ending motion, both of the leg will be in the same position and both legs stand on the ground. iii. equations the main formula use for the bipedal robot is based on the triangle formulation (figure 5), and described in equation (1) to (4). 𝐻𝐻ℎ2 = 𝑙𝑙1 2 + 𝑙𝑙2 2 − 2𝑙𝑙1𝑙𝑙2 cos 𝛽𝛽 (1) 𝑙𝑙1 2 = 𝐻𝐻ℎ2 + 𝑙𝑙2 2 − 2𝑙𝑙1𝑙𝑙2 cos 𝑠𝑠2 (2) 𝑙𝑙2 2 = 𝐻𝐻ℎ2 + 𝑙𝑙1 2 − 2𝑙𝑙1𝑙𝑙2 cos 𝑠𝑠1 (3) 𝑙𝑙1 sin 𝑠𝑠2 = 𝑙𝑙2 sin 𝑠𝑠1 = 𝐻𝐻ℎ sin 𝛽𝛽 (4) figure 2. starting motion diagram [1]. figure 4. ending motion diagram [1]. figure 3. full motion diagram [1]. g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 106 a. angle value between reference lines the equation to find the angle value between reference lines is: 𝑠𝑠𝑇𝑇 = tan−1 � 𝑆𝑆(𝑡𝑡) 𝐻𝐻ℎ(𝑡𝑡) � (5) where θt is the angle value between reference lines. b. reference line value the equation to calculate the value of the reference line of black leg and red leg are: 𝐻𝐻ℎ1 = 𝐻𝐻ℎ(𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) (6) 𝐻𝐻ℎ1 = 𝐻𝐻ℎ(𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) − ℎ (𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) (7) 𝐻𝐻ℎ1 = (𝐻𝐻ℎ2 )(cos(𝑠𝑠𝑇𝑇)) − ℎ(𝑡𝑡) (8) 𝐻𝐻ℎ1 = 𝐻𝐻ℎ(𝑡𝑡) (9) 𝐻𝐻ℎ2 = (𝐻𝐻ℎ1 )(cos(𝑠𝑠𝑇𝑇)) − ℎ(𝑡𝑡) 2 (10) 𝐻𝐻ℎ2 = 𝐻𝐻ℎ(𝑡𝑡) (11) 𝐻𝐻ℎ2 = 𝐻𝐻ℎ(𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) (12) 𝐻𝐻ℎ2 = 𝐻𝐻ℎ(𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) − ℎ (𝑡𝑡) cos (𝑠𝑠𝑇𝑇 ) (13) 𝐻𝐻ℎ2 = (𝐻𝐻ℎ1 )(cos(𝑠𝑠𝑇𝑇)) − ℎ(𝑡𝑡) (14) 𝐻𝐻ℎ2 = 𝐻𝐻ℎ(𝑡𝑡) (15) where: 𝐻𝐻ℎ1 : reference line of the black leg 𝐻𝐻ℎ2 : reference line of the red leg 𝐻𝐻ℎ(𝑡𝑡) : reference line value with respect to time. eq. 6 is to find the reference line value of the black leg in figure 2 and 4 at time t = 0 until time t = tf/2 (number 1 until number 3). eq. 7 is to find the reference line value of the black leg at the reference line value of the black leg at time t = tf /2 until time t = tf (number 3 until number 5). for figure 4, eq. 8 is used to find the reference line value of the black leg at time t = 0 until time t = tf /2 (number 1 until number 3). eq. 9 is to find the reference line value of the black leg at t = tf /2 until time t = tf (number 3 until number 5). eq. 10 is to find the reference line value of the red leg in figure 2 at time t = 0 until time t = tf /2 (number 1 until number 3), and eq. 11 is to find the reference line value of the red leg at time t = tf /2 until time t = tf (number 3 until number 5). for figure 3, eq. 12 is to find the reference line value of the red leg in figure 4 at time t = 0 until time t = tf /2 (number 1 until number 3), and eq. 13 is to find the reference line value of the red leg at time t = tf /2 until time t = tf (number 3 until number 5). for figure 4, eq. 14 is to find the reference line value of the red leg at time t = 0 until time t = tf /2 (number 1 until number 3), and eq. 15 is to find the reference line value of the red leg at time t = tf /2 until time t = tf (number 3 until number 5). c. angle value at hip joint, knee joint and ankle joint the equations for angle value at hip joint for all motions (figure 2, figure 3 and figure 4) are: 𝑠𝑠2,1 = − cos−1 � 𝑙𝑙12 +𝐻𝐻ℎ22 +𝑙𝑙22 2𝑙𝑙1𝐻𝐻ℎ2 � (16) 𝑠𝑠1,1 = cos−1 � 𝑙𝑙12 +𝐻𝐻ℎ12 +𝑙𝑙22 2𝑙𝑙1𝐻𝐻ℎ1 � (17) the equation for angle value at ankle joints are: 𝑠𝑠1,3 = −�𝑠𝑠1,2 − 𝑠𝑠1,1� − 𝑠𝑠𝑇𝑇 (18) 𝑠𝑠2,3 = �𝑠𝑠2,2� + 𝑠𝑠2,1 + 𝑠𝑠𝑇𝑇 (19) 𝑠𝑠1,3 = −�𝑠𝑠1,2 − 𝑠𝑠1,1� (20) 𝑠𝑠2,3 = �𝑠𝑠2,2� + 𝑠𝑠2,1 (21) where: 𝑠𝑠1,1 : angle value at black leg hip joint 𝑠𝑠1,2 : angle value at black leg knee joint 𝑠𝑠1,3 : angle value at black leg ankle joint 𝑠𝑠2,1 : angle value at black leg hip joint 𝑠𝑠2,2 : angle value at black leg knee joint 𝑠𝑠2,3 : angle value at black leg ankle joint eq. 18 is used in starting motion and ending motion, with the assumption that the leg that swings first is according to the figures 2 and 4. eq. 19 is used in full motion for the red leg in figure 3. eq. 20 is used for the black leg for full motion in figure 3. eq. 21 is used for the red leg in starting motion and ending motion in figures 3 and 4. these equations can be switched (between the equations that contain the 𝑠𝑠𝑇𝑇 1 and the equations that do not contain the 𝑠𝑠𝑇𝑇, i.e. between equations 18 and 20 or equations 19 and 21) depend on the position of the red leg and the figure 5. triangle diagram [1]. g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 107 black leg in the motions. the equations for angle value at knee joints are: 𝑠𝑠1,2 = cos−1 � 𝑙𝑙22 +𝐻𝐻ℎ12 +𝑙𝑙12 2𝑙𝑙2𝐻𝐻ℎ1 � + 𝑠𝑠1,1 (22) 𝑠𝑠2,2 = −�cos−1 � 𝑙𝑙22 +𝐻𝐻ℎ22 +𝑙𝑙12 2𝑙𝑙2𝐻𝐻ℎ2 �� + 𝑠𝑠2,1 (23) the theta and reference line results of the starting motion, full motion and the ending motion are shown at table 1, table 2, and table 3. d. hip height equations figure 6 is the requested linear graph example of hip height, where the initial time is t = 0 and the time final is tf = 4. basic equation for the linear equation is: 𝑦𝑦−𝑦𝑦1 𝑦𝑦2−𝑦𝑦1 = 𝑥𝑥−𝑥𝑥1 𝑥𝑥2−𝑥𝑥1 (24) from figure 6, y equal to hh and x equal to t. the equation 24 then become: 𝐻𝐻ℎ−𝐻𝐻ℎ1 𝐻𝐻ℎ2−𝐻𝐻ℎ1 = 𝑡𝑡−𝑡𝑡1 𝑡𝑡2−𝑡𝑡1 (25) the equation for time t = 0 until time t = tf/2 for hip height is: 𝐻𝐻ℎ(𝑡𝑡) = �2𝑡𝑡 𝑡𝑡𝑓𝑓 (−ℎ)� + 𝐻𝐻ℎ (26) the equation for time t = tf /2 until time t = tf for hip height is: 𝐻𝐻ℎ(𝑡𝑡) = � 2𝑡𝑡−𝑡𝑡𝑓𝑓 𝑡𝑡𝑓𝑓 (ℎ)� + (𝐻𝐻ℎ − ℎ) (27) table 1. theta value and reference line result for starting motion. θt/deg hh1/mm θ1,1/deg θ1,2/deg hh2/mm θ2,1/deg θ2,2/deg θ1,3/deg θ2,3/deg 0.0 230.0 41.3 71.9 230.0 -41.3 -71.9 -30.6 30.6 2.6 217.7 48.5 85.5 205.0 -60.6 -102.9 -37.0 42.3 5.6 206.0 54.3 96.2 180.0 -79.1 -128.5 -41.9 49.3 8.9 194.8 59.1 104.8 180.0 -79.1 -128.5 -45.7 49.3 12.5 184.4 63.1 111.6 180.0 -79.1 -128.5 -48.4 49.3 8.9 182.2 68.6 117.5 192.5 -69.7 -116.0 -48.9 46.4 5.6 180.9 72.9 122.0 205.0 -60.6 -102.9 -49.2 42.3 2.6 180.2 76.3 125.6 127.5 -51.3 -88.4 -49.3 37.1 0.0 180.0 79.1 128.5 230.0 -41.3 -71.9 -49.3 30.6 table 2. theta value and reference line result for full motion. θt/deg hh1/mm θ1,1/deg θ1,2/deg hh2/mm θ2,1/deg θ2,2/deg θ1,3/deg θ2,3/deg 0.0 180.0 79.1 128.5 230.0 -41.3 -71.9 -49.3 30.6 2.6 180.0 79.1 128.5 217.7 -48.5 -85.5 -49.3 37.0 5.6 180.0 79.1 128.5 206.0 -54.3 -96.2 -49.3 41.9 8.9 180.0 79.1 128.5 194.8 -59.1 -104.8 -49.3 45.7 12.5 180.0 79.1 128.5 184.4 -63.2 -111.6 -49.3 48.4 8.9 192.5 69.7 116.0 182.2 -68.6 -117.5 -46.4 48.9 5.6 205.0 60.6 102.9 180.9 -72.9 -122.0 -42.3 49.2 2.6 217.5 51.3 88.4 180.2 -76.3 -125.6 -37.1 49.3 0.0 230.0 41.3 71.9 180.0 -79.1 -128.5 -30.6 49.3 table 3. theta value and reference line result for ending motion. θt/deg hh1/mm θ1,1/deg θ1,2/deg hh2/mm θ2,1/deg θ2,2/deg θ1,3/deg θ2,3/deg 0.0 230.0 41.3 71.9 180.0 -79.1 -128.5 -30.6 49.3 2.6 217.7 48.5 85.5 180.0 -79.1 -128.5 -37.0 49.3 5.6 206.0 54.3 96.2 180.0 -79.1 -128.5 -41.9 49.3 8.9 194.8 59.1 104.8 180.0 -79.1 -128.5 -45.7 49.3 12.5 184.4 63.2 111.6 180.0 -79.1 -128.5 -48.4 49.3 8.9 194.8 59.1 104.8 192.5 -69.7 -116.0 -45.7 46.4 5.6 206.0 54.3 96.2 205.0 -60.6 -102.9 -41.9 42.3 2.6 217.7 48.5 85.5 217.5 -51.3 -88.4 -37.0 37.1 0.0 230.0 41.3 71.9 230.0 -41.3 -71.9 -30.6 30.6 g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 108 where hh : requested value of hip height t : time of the motion tf : time final value h : requested height of the swinging leg value e. step distance equation figure 7 is the linear graph example of step distance where the initial time is t = 0 and the time final is tf = 4. the equation for time t = 0 until t = tf /2 is: 𝑆𝑆(𝑡𝑡) = 2𝑆𝑆𝑡𝑡 𝑡𝑡𝑓𝑓 (28) the equation for time t = tf /2 until time t = tf is : 𝑆𝑆(𝑡𝑡) = � �2𝑡𝑡−𝑡𝑡𝑓𝑓�(−𝑆𝑆) 𝑡𝑡𝑓𝑓 � + 𝑆𝑆 (29) where s(t) : step distance value with respect to time s : requested step distance value f. height of swinging leg equations figure 8 is the linear graph example of height of the swinging leg in starting motion. the equation for time t = 0 until time t = tf /4 is: ℎ(𝑡𝑡) = 4ℎ𝑡𝑡 𝑡𝑡𝑓𝑓 (30) the equation for time t = tf /4 until time t = tf/2 is: ℎ(𝑡𝑡) = �� 4𝑡𝑡−2𝑡𝑡𝑓𝑓 𝑡𝑡𝑓𝑓 � (−ℎ)� + ℎ (31) where h(t) is height of the swinging leg value with respect to time. the equation for time t = tf /2 until time t = tf is: ℎ(𝑡𝑡) = � 2𝑡𝑡−𝑡𝑡𝑓𝑓 𝑡𝑡𝑓𝑓 � (ℎ) (32) figure 9 is the linear graph example of height of the swinging leg in full motion. the equation for time t = 0 until time t = tf /2 is: ℎ(𝑡𝑡) = ��2𝑡𝑡 𝑡𝑡𝑓𝑓 � (−ℎ)� + ℎ (33) the equation for time t = tf /2 until time t = tf in full motion is the same with equation 32, which is also used for time t = tf /2 until time t = tf in starting motion. figure 10 is the linear graph example of height of the swinging leg in ending motion. the equation for time t = 0 until time t = tf /2 is the same with equation 33, which is also used for time time t = 0 until time t = tf /2 in full motion. the equation for t = tf /2 until time t = 3tf /4 is: ℎ(𝑡𝑡) = �� 4𝑡𝑡−3𝑡𝑡𝑓𝑓 𝑡𝑡𝑓𝑓 ��−ℎ 2 �� + ℎ 2 (35) figure 6. linear graph for hh (hip height) [1]. figure 7. linear graph for s (step distance) [1]. figure 9. linear graph 2 for height of the swinging leg [1]. figure 8. linear graph for height of the swinging leg [1]. g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 109 iv. result and discussion figure 11 is the actual result by using the results of the equations above as the input value for the program in the microcontroller [15]. the bipedal robot is able to move forward, which can be seen that the reference line (red line) forming an angle value with the vertical line (perpendicular to the ground, which is the yellow line). the motion that is repeated more than once is only the full motion, which resulting the non stop walking motion of the bipedal robot. take note that the bipedal robot in figure 11 is supported with cable, which tied on the hip part. v. concluding remarks from the graphical result of the angle value and the change of hip height, height of the swinging leg and step distance value, it is shown that in the beginning of the starting motion and in the end of the starting motion bipedal robot will achieve one step forward. it is also shown in the full motion and the ending motion where from the graphical result, the bipedal robot is able to take steps forward. the main contribution of this work is the introduction of 𝑠𝑠𝑇𝑇 where this angle synchronize the left and right leg. the observation of this gait movement is done qualitatively. the ergonomic of leg design need to be further considered. since during the qualitative observation, some condition of gait movement need to be further explored. references [1] gerald wahyudi setiono, "kinematic model analysis and development of walking algorithm for 5 degree of freedom bipedal robot," swiss german university, bsdcity, tangerang, bachelor thesis 2012. [2] priya johnson. (2012, june). biology terms glossary of biology terms and definitions. [online]. available: http://www.buzzle.com/articles/biologyterms-glossary-of-biology-terms-anddefinitions.html [3] e. cuevas, d. zaldivar, e. tapia, and r. rojas, "an incremental fuzzy algorithm for the balance of humanoid robots," 2007. [4] kåre (a.k.a zenta) halvorsen, "zenta, archer, an ik controlled biped," sept 2011. [5] siswoyo jo h., mir-nasiri n., and jayamani e., "design and trajectory planning of bipedal walking robot with minimum sufficient actuation system," 2009. [6] farsam farzadpour and mohammad danesh, "ga based trajectory generation for a 7dof biped robot by considering feet rotation during double support phase," 2011. [7] kemalettin erbatur and okan kurt, "natural zmp trajectories for biped robot reference generation," ieee transactions on industrial electronics, vol. 56, march 2009. [8] c. chevallereau, d. djoudi, and j. w. grizzle, "stable bipedal walking with foot rotation through direct regulation of the zero moment point," ieee transactions on robotics, pp. 390 401, april 2008. [9] stefan czarnetzki, soeren kerner, and oliver urbann, "applying dynamic walking figure 10. linear graph 3 for height of the swinging leg [1]. figure 11. qualitative gait result [1]. g.w. setiono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 103-110 110 control for biped robots," robocup 2009 : robot soccer world cup xiii, lecture notes in computer science, vol. 5949, pp. 69 80, 2010. [10] kajita et. al. , "biped walking stabilization based on linear inverted pendulum tracking," the 2010 ieee/rsj international conference on intelligent robots and systems, october 2010. [11] taesin ha and chong-ho choi, "an effective trajectory generation method for bipedal walking," robotics and autonomous systems 55, pp. 795 810, 2007. [12] pieter van zutven, dragan kostic, and henk nijmeijer, "on the stability of bipedal walking," simulation, modelling, programming for autonomous robots, lecture notes in computer science, vol. 6472, pp. 521 532, 2010. [13] fumihiko asano and zhi-wei luo, "asymptotically stable gait generation for biped robot based on mechanical energy balance," proceedings of the 2007 ieee/rsj international conference on intelligent robots and systems, november 2007. [14] seungsuk ha, youngjoon han, and hernsoo hahn, "adaptive gait pattern generation of biped robot based on human’s gait pattern analysis," international journal of aerospace and mechanical engineering 1:2, 2007. [15] adrian felix sutanto, "design and implementation of fuzzy auto-balance control for bipedal robot," swiss german university, bsd city, tangerang, bachelor thesis 2012. microsoft word vol03_no1_vcetak mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012   www.mevjournal.com © 2012 rcepm lipi all rights reserved modelling and identification of oxygen excess ratio of self-humidified pem fuel cell system pemodelan dan identifikasi rasio kelebihan oksigen pada sistem self-humidified pem fuel cell edi leksono a,*, justin pradipta a, tua agustinus tamba b a laboratorium manajemen energi, teknik fisika – institut teknologi bandung gedung tp rahmat lt.3, jl. ganesha no. 10 bandung, jawa barat 40132, indonesia b department of electrical engineering – university of notre dame 275 fitzpatrick hall of engineering, notre dame, in 46556, usa received 6 june 2012; received in revised form 9 july 2012; accepted 9 july 2012 published online 31 july 2012 abstract one essential parameter in fuel cell operation is oxygen excess ratio which describes comparison between reacted and supplied oxygen number in cathode. oxygen excess ratio relates to fuel cell safety and lifetime. this paper explains development of air feed model and oxygen excess ratio calculation in commercial self-humidified pem fuel cell system with 1 kw output power. this modelling was developed from measured data which was limited in open loop system. it was carried out to get relationship between oxygen excess ratio with stack output current and fan motor voltage. it generated fourth-order 56.26% best fit arx linear polynomial model estimation (loss function = 0.0159, fpe = 0.0159) and second-order arx nonlinear model estimation with 75 units of wavenet estimator with 84.95% best fit (loss function = 0.0139). the second-order arx model linearization yielded 78.18% best fit (loss function = 0.0009, fpe = 0.0009). key words: pem fuel cell, self-humidified, oxygen excess ratio, system identification, polynomial model. abstrak salah satu parameter pengoperasian fuel cell adalah rasio kelebihan oksigen yang menggambarkan perbandingan antara jumlah oksigen yang bereaksi dengan jumlah oksigen yang dipasok pada katode fuel cell. rasio kelebihan oksigen penting untuk diperhatikan karena berkaitan dengan keselamatan operasi dan usia penggunaan fuel cell. makalah ini memaparkan teknik penentuan model masukan udara dan perhitungan rasio kelebihan oksigen pada self-humidified pem fuel cell komersial dengan daya keluaran 1 kw. pemodelan dilakukan berdasarkan data hasil pengukuran yang relatif terbatas pada sistem loop terbuka. persamaan rasio kelebihan oksigen kemudian ditentukan dengan menggunakan model pasokan udara. identifikasi loop terbuka dengan model arx dilakukan untuk memperoleh hubungan antara rasio kelebihan oksigen terhadap nilai arus stack dan tegangan motor fan. berdasarkan hasil identifikasi sistem diperoleh bahwa estimasi polinomial linier arx orde 4 menghasilkan tingkat kecocokan 56,26% (loss function = 0,0159; final prediction error (fpe) = 0,0159) dan estimasi model non linier arx orde 2 dengan estimator wavenet 75 unit menghasilkan tingkat kecocokan 84,95% (loss function = 0,0139). untuk kemudahan perancangan sistem kontrol, linearisasi dilakukan pada model non linier arx dan menghasilkan model arx orde 2 dengan tingkat kecocokan 78,18% (loss function 0,0009; fpe 0,0009). kata kunci: pem fuel cell, self-humidified, rasio kelebihan oksigen, identifikasi sistem, model polinomial. i. pendahuluan seiring dengan perkembangan dan kemajuan teknologi, kebutuhan akan ketersediaan energi dan perangkat konversi energi juga semakin meningkat. hal ini mendorong berbagai upaya penelitian dan pengembangan dalam perangkat baru konversi energi. salah satu alternatifnya adalah fuel cell yang dianggap memiliki prospek yang baik sebagai solusi perangkat dan sistem konversi energi. fuel cell merupakan suatu perangkat yang membangkitkan energi listrik berdasarkan reaksi elektrokimia bahan bakarnya. fuel cell tidak menghasilkan gas emisi seperti yang sering ditemukan pada proses pembakaran dan hanya menghasilkan air serta energi panas * corresponding author. tel: +62-22-2509161 e-mail: edi@tf.itb.ac.id e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 40 sebagai hasil sampingan. fuel cell dapat diklasifikasikan berdasarkan bahan elektrolitnya, yaitu: alkaline fuel cell (afc), phosphoric acid fuel cell (pafc), molten carbonate fuel cell (mcfc), solid oxide fuel cell (sofc), proton exchange membrane fuel cell (pemfc), direct methanol fuel cell (dmfc), regenerative fuel cell (rfc), dan zinc-air fuel cell (zafc). di antara berbagai macam fuel cell tersebut, yang dipilih menjadi objek kajian dalam makalah ini adalah proton exchange membrane (pem) fuel cell, yang telah banyak digunakan dalam berbagai aplikasi. hingga saat ini terdapat beberapa penelitian yang dihasilkan tentang pembuatan model dan sistem kontrol untuk sistem fuel cell, di antaranya [1-15]. penurunan model analitis secara ekstensif yang mencakup dinamika seluruh perangkat pendukung sistem fuel cell telah diteliti pada [1]. walaupun karakteristik operasi fuel cell-nya lengkap, model tersebut tidak cocok digunakan untuk aplikasi praktis karena banyaknya jumlah parameter operasi yang dapat mengakibatkan proses analisis menjadi rumit serta komputasi menjadi sangat kompleks. penelitian pada makalah [3] mengusulkan model fuel cell yang lebih praktis dengan menggabungkan penurunan model analitis dan verifikasi secara eksperimen. model pem fuel cell berorientasi kontrol yang menjelaskan fenomena kelaparan hidrogen atau oksigen (oxygen/hydrogen starvation) pada stack dipaparkan pada [2] dan [4]. teknik identifikasi sistem dipaparkan di [5] untuk menurunkan hubungan linier input-output pada sistem fuel cell pada beberapa titik operasi. model yang diperoleh kemudian digunakan untuk simulasi perancangan kontrol adaptif pada fuel cell. kontrol umpan balik dan model predictive control yang mengatur kecepatan suplai oksigen dari kompresor untuk menjaga rasio kelebihan oksigen (perbandingan antara oksigen yang bereaksi dan oksigen yang dipasok ke katode) pada nilai yang diinginkan dijelaskan pada [2] dan [6]. pada penelitian [7] dijelaskan pentingnya memberikan masukan oksigen yang mencukupi pada fuel cell jenis open cathode untuk menjaga performa fuel cell, dan penelitian pada [8] dinyatakan bahwa tekanan parsial oksigen pada katode mempengaruhi usia pakai membran fuel cell. meskipun telah banyak kemajuan yang dihasilkan sejauh ini, beberapa masalah pada perancangan kontrol fuel cell masih belum terpecahkan, salah satunya adalah pemilihan pasangan variabel proses/kontrol dan pemilihan algoritma kontrol. makalah ini memaparkan penentuan model dinamik suatu sistem pem fuel cell komersial. sistem fuel cell yang ditinjau merupakan jenis self-humidified dan open cathode, dimana empat fan yang disusun secara paralel berperan sebagai pemasok oksigen (suplai reaktan) dan udara pendingin (sistem pendingin). rancangan open cathode membedakan sistem yang ditinjau dari jenis sistem fuel cell umumnya dimana suplai oksigen kebanyakan dialirkan secara khusus dari tabung oksigen. meskipun menghasilkan sistem yang lebih modular dan ekonomis, rancangan open cathode juga mengakibatkan analisis menjadi lebih kompleks karena jumlah variabel yang dapat diukur dan digunakan untuk pemodelan dan pengontrolan menjadi terbatas. kontribusi dari makalah ini adalah pengembangan prosedur sistematis untuk pemodelan sistem fuel cell jenis open cathode berdasarkan jumlah variabel pengukuran yang terbatas. model yang diajukan diperoleh dengan menggabungkan metode analitis (berdasarkan reaksi elektrokimia dan dinamika fuel cell) dan metode identifikasi sistem black box. model ini selanjutnya dapat digunakan untuk pengembangan sistem fuel cell lebih lanjut (perancangan sistem kontrol, optimasi, dll). ii. deskripsi sistem a. pem fuel cell suatu perangkat fuel cell umumnya terdiri dari anode dan katode yang dipisahkan oleh elektrolit. dalam pem fuel cell, membran polimer berfasa padat digunakan sebagai elektrolit. keunggulan pem fuel cell dibandingkan fuel cell jenis lainnya antara lain mampu beroperasi pada temperatur yang relatif lebih rendah dengan respon start-up yang cepat, mudah dimanufaktur dan tidak mudah terkorosi. gambar 1 menunjukkan operasi perangkat pem fuel cell. bahan bakar hidrogen yang diumpankan pada sisi anode dan gas oksigen (atau udara yang mengandung oksigen) yang diumpankan pada sisi katode akan bereaksi secara elektrokimia di dalam sel dengan bantuan katalis. reaksi elektrokimia dasar yang berlangsung secara simultan pada kedua sisi membran dapat dinyatakan sebagai berikut. anoda gdl gdl katoda membran 2h 2h 2h 2o oh 2 2o 2h −e2 k atalis k at al is +h2 −e2 oh 2 22 1 o beban −e2 gambar 1. skema operasi fuel cell. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 41 anode  : 2 2 katode  : 2 2 total  : . (1) selama reaksi berlangsung, membran elektrolit berperan sebagai jalur konduktif yang melewatkan ion h+ dari anode untuk bergabung dengan ion odi katode dan membentuk molekul air (h2o). akibat sifat alami dari membran yang tidak melewatkan elektron untuk melintas, maka elektron akan melintas melalui sirkuit elektrik eksternal yang kemudian dapat digunakan untuk menghasilkan arus listrik. fuel cell akan menghasilkan arus listrik secara kontinyu selama pasokan hidrogen dan oksigen tersedia. hasil sampingan dari reaksi di dalam sel adalah panas dan air. b. pem fuel cell horizon h-1000 sistem yang didiskusikan dalam makalah ini adalah fuel cell komersial model h-1000 buatan horizon fuel cell technologies. fuel cell ini merupakan tipe self-humidified dan open cathode, menggunakan hidrogen sebagai bahan bakar dan udara sebagai sumber oksidan. hidrogen dipasok dari tangki penyimpanan eksternal, sedangkan oksigen diperoleh dari udara bebas dengan bantuan putaran fan. susunan fuel cell terdiri dari 72 sel yang dapat menghasilkan daya keluaran hingga 1 kw dengan tegangan nominal antara 3969 volt. gambar 2 menunjukkan sistem fuel cell terdiri dari modul susunan fuel cell dan modul pengontrol yang terhubung dengan konektor 8 kabel. modul pengontrol berfungsi sebagai pengatur laju putaran fan (berdasarkan umpan balik pengukuran temperatur stack dan daya keluaran fuel cell) dan bukaan periodik purging valve dan valve pasokan hidrogen. pengontrol juga dirancang untuk melakukan shut-down jika daya yang digunakan oleh beban melebihi daya keluaran maksimum fuel cell [19]. proses pengukuran dan akuisisi data pada sistem pem fc h-1000 dilakukan dengan menggunakan modul akusisi data ni daq usb 6008 serta aplikasi program labview seperti ditunjukkan pada gambar 3. pengukuran dan akuisisi data dilakukan pada dua kondisi operasi pem fc h-1000. kondisi pertama adalah pengoperasian pada loop tertutup dimana pem fc h-1000 dijalankan secara normal dengan menggunakan modul pengontrol asli buatan pabrik (gambar 3(a)). kondisi kedua adalah pengoperasian pada loop terbuka dimana modul pengontrol asli pem fc h-1000 tidak digunakan dan sistem dijalankan secara manual dengan perintah langsung dari komputer (gambar 3(b)). operasi pada loop terbuka bertujuan untuk menganalisis respon sistem terhadap perubahan input agar sistem dapat dimodelkan. variabel proses yang diukur meliputi tegangan pada valve suplai hidrogen , , tegangan pada purging valve hidrogen , , tegangan suplai pada motor fan , tegangan keluaran stack , dan arus stack . iii. pemodelan dan identifikasi beberapa objek dan fokus pemodelan dan pengontrolan sistem fuel cell telah dilaporkan pada berbagai literatur yang antara lain mencakup pemodelan dan pengontrolan jumlah pasokan bahan bakar dan oksidan yang tepat ke dalam stack, temperatur stack optimal, atau tekanan operasi stack optimal. secara khusus, pemodelan dan pengaturan jumlah reaktan yang disuplai dan bereaksi pada stack merupakan faktor penting karena berhubungan dengan efisiensi kerja dan keselamatan operasi fuel cell. selain itu, kesalahan dalam pengaturan jumlah pasokan reaktan fuel cell dalam jangka panjang dapat mengakibatkan terjadinya fenomena membrane starvation (kelaparan membran) yang pada akhirnya akan merusak membran fuel cell [2,3,4]. termotivasi oleh kondisi tersebut, maka teknik pemodelan yang diajukan pada makalah ini difokuskan pada model pasokan jumlah reaktan yang tepat pada fuel cell demi menjamin gambar 2. sistem fuel cell horizon h-1000. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 42 efisiensi dan keselamatan operasi fuel cell. akibat suplai hidrogen pada sistem yang ditinjau beroperasi dengan mode dead-end, maka pemodelan difokuskan pada sistem pasokan oksigen, yang disesuaikan dengan daya keluaran fuel cell. a. rasio kelebihan oksigen rasio kelebihan oksigen merupakan perbandingan antara jumlah oksigen yang dipasok ke katode dengan jumlah oksigen yang diperlukan pada reaksi di dalam pemfc untuk membangkitkan energi listrik. rasio kelebihan oksigen merupakan variabel terkumpul yang tidak dapat diukur langsung dan harus diestimasi melalui pengukuran lainnya. estimasi dapat dilakukan berdasarkan data pengukuran laju aliran udara masuk katode, arus stack, tekanan masuk katode, kelembaban relatif udara masuk, dan temperatur masukan katode. rasio kelebihan oksigen merupakan salah satu variabel unjuk kerja yang penting pada fuel cell karena berhubungan dengan keselamatan membran pada fuel cell. nilai rasio kelebihan oksigen yang terlalu rendah dapat memicu terjadinya fenomena kelaparan oksigen pada membran. berdasarkan [6], nilai rasio kelebihan oksigen yang aman adalah 4 . rasio kelebihan oksigen didefinisikan pada [1] sebagai persamaan (2): , , , (2) dengan laju aliran massa oksigen , , merupakan fungsi dari laju aliran massa udara kering , , menuju katode dan fraksi massa oksigen , , sebagai persamaan (3). sedangkan fraksi massa oksigen , , dinyatakan oleh persamaan (4) (a) (b) gambar 3. pengaturan pengukuran; (a) pengaturan pengukuran loop tertutup; (b) pengaturan pengukuran loop terbuka. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 43 , , , , , , (3) , , , , , , , , (4) dengan dan menyatakan massa molar dari oksigen dan nitrogen. oksigen diasumsikan mempunyai fraksi mol , , 0,21 . laju aliran massa udara kering pada masukan katode didefinisikan sebagai persamaan (5). dengan rasio kelembaban , dinyatakan oleh persamaan (6) , , , , , (5) , , , , , , , (6) dengan adalah massa molar uap air. massa molar dari udara pada masukan katode ditentukan dengan persamaan (7): , , , , 1 , , (7) tekanan uap air , , dan tekanan udara kering , , yang digunakan pada perhitungan rasio kelembaban , dinyatakan sebagai berikut: , , , , (8) , , , , , (9) dengan , menyatakan kelembaban relatif pada masukan katode dan , menyatakan tekanan saturasi uap air pada temperatur dan tekanan tertentu. laju konsumsi oksigen proporsional dengan arus yang dibangkitkan, , , (10) dengan n = 72 menyatakan jumlah sel pada stack dan f = 96485 adalah konstanta faraday. akibat bentuk susunan fuel cell yang digunakan tidak memungkinkan dilakukannya pengukuran tekanan masukan katode , secara langsung, maka , ditentukan dengan model matematis [3]. tekanan masukan katode terdiri atas beberapa persamaan diferensial yang membutuhkan komputasi kompleks. untuk memperoleh model yang lebih sederhana, maka model , pada [3] digunakan pada penelitian ini. model tersebut secara eksplisit menyatakan bahwa tekanan udara masukan pada katode berhubungan langsung dengan laju aliran udara , pada masukan katode dan reaksi di dalam susunan fuel cell. dengan demikian hubungan antara tekanan udara masukan katode , dan arus stack dapat dinyatakan sebagai berikut: , 1,0033 2,1 10 , 475,7 10 (11) b. pemetaan fungsi fan laju aliran udara , pada masukan katode dapat ditentukan berdasarkan suplai udara kering dari fan. akibat data pengukuran tegangan fan tidak dapat langsung digunakan pada perhitungan rasio kelebihan oksigen, maka hubungan antara tegangan fan dengan laju aliran masa udara , dilakukan dengan pemetaan. fan yang terpasang pada sistem fuel cell horizon h-1000 berfungsi sebagai pendingin dan sekaligus sebagai pemasok oksigen untuk kebutuhan reaksi fuel cell. untuk memetakan fungsi tegangan masukan fan terhadap laju aliran massa udara, maka dilakukan variasi tegangan masukan pada fan (0-12 v). pada setiap kenaikan tegangan masukan fan, kecepatan udara yang melewati fan diukur dengan menggunakan anemometer. hasil pengukuran ditampilkan pada tabel 1. luas penampang total fan ditentukan berdasarkan data pengukuran diameter nominal pada masing-masing fan (gambar 4) sebagai berikut: /2 (12) tegangan masukan (v) kecepatan udara (m/s) 0 0 1 0 2 0 3 0,6 4 1 5 1,4 6 1,9 7 2,3 8 2,8 9 3,2 10 3,7 11 4,1 tabel 1 tegangan input dan kecepatan udara fan. gambar 4. fan untuk pendinginan sekaligus pasokan oksigen. 9 4 e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 44 (13) berdasarkan nilai luas penampang total pada fan serta kecepatan udara yang melewati penampang tersebut, laju volumetrik dari udara pada fan dapat ditentukan seperti persamaan (14): (14) dengan menggunakan asumsi nilai massa jenis udara = 1,19 gram/liter pada temperatur 25°c dan tekanan 1 atm, maka laju aliran massa udara yang dipergunakan untuk perhitungan rasio kelebihan oksigen adalah , , (15) berdasarkan data hasil pengukuran dan perhitungan, hubungan antara tegangan masukan motor fan terhadap kecepatan aliran massa udara (gram/detik) yang melalui fan diperoleh sebagai fungsi polinomial orde 3 sebagai berikut. , 0,0966 1,965 0,77 2,21 (16) c.  operasi kontrol dari horizon unit kontrol horizon digunakan untuk memberikan gambaran kerja normal fuel cell. pada awal sebelum beroperasi, tekanan hidrogen harus dibuat diantara 7-9 psi untuk menjamin ketersediaan hidrogen dalam stack. jika hidrogen tidak mencukupi untuk menghasilkan daya yang dibutuhkan, maka pengontrol secara otomatis melakukan shut-down pada sistem fuel cell. modul pengontrol juga memungkinkan dilakukannya arus singkat pada stack sesaat untuk mengembalikan performa fuel cell ketika (a) (b) (c) (d) (e) (f) (g) gambar 5. grafik kerja fuel cell; (a) tegangan listrik pada supply valve; (b) tegangan listrik pada purging valve; (c) tegangan listrik pada stack; (d) arus listrik pada stack; (e) tegangan listrik pada kipas; (f) temperatur stack; (g) rasio kelebihan oksigen. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 45 terjadi drop tegangan (hingga nol) pada stack atau apabila terjadi kejenuhan di dalam stack. gambar 5(a)–(g) menampilkan grafik kerja fuel cell dalam kondisi normal menggunakan modul pengontrol dari horizon. d. identifikasi sistem data untuk proses identifikasi dikumpulkan berdasarkan skema operasi loop terbuka. ada tiga variabel proses utama yang digunakan pada proses identifikasi yaitu tegangan masukan pada fan , arus stack , dan rasio kelebihan oksigen . proses identifikasi dilakukan dengan menganggap sistem pem fc h-1000 sebagai black box dengan dua masukan ( dan ) dan satu keluaran ( ), seperti ditunjukkan pada gambar 6 [3,7]. sinyal hasil pengukuran kemudian dibagi menjadi dua, masing-masing untuk proses estimasi dan validasi. data untuk estimasi ditampilkan pada gambar 7 dan untuk validasi pada gambar 8. proses identifikasi kemudian dilakukan dengan menggunakan system identification toolbox di matlab [16]. oleh karenanya, identifikasi model parametrik dengan estimator non linier diharapkan mampu memberikan hasil yang lebih baik. estimator non linier yang digunakan pada penelitian ini adalah estimator non linier wavenet 75 unit, dan model yang diperoleh adalah model parametrik arx non linier orde 2 dengan regressor standar [y1(t1); y(t-2); u1(t-1); u1(t-2); u2(t-1); u2(t-2)]. hasil simulasi identifikasi dengan model non linier pada gambar 9 (b) menunjukkan bahwa model nonlinier yang diperoleh dapat mewakili karakteristik sistem, tetapi membutuhkan komputasi yang rumit dan kurang efisien ketika digunakan pada aplikasi praktis. untuk mendapatkan model yang dapat digunakan untuk aplikasi praktis, maka dilakukan linierisasi pada model non linier yang diperoleh. linierisasi model hasil identifikasi dapat dilakukan dengan menggunakan fungsi linierisasi linapp pada system identificatiaon toolbox matlab. fungsi linapp pada dasarnya meminimalkan mean square error pada batasan data tertentu. dengan menggunakan data validasi sebagai batasan, proses linierisasi menghasilkan horizon pem fc h-1000 sti fmv 2o λ gambar 6. diagram blok identifikasi sistem pem fc h-1000. gambar 8. data untuk validasi hasil estimasi model. gambar 7. data untuk estimasi model, output: y1=rasio kelebihan oksigen, input : u1=arus stack, u2=tegangan fan. tabel 2 validasi model dengan beberapa criteria. model kriteria best fit loss function fpe arx orde 4 56,26 % 0,0159 0,0159 arx non linier orde 2 84, 95 % 0,0139 linierisasi arx non linier orde 2 78, 18% 0,0009 0,0159 e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 46 model arx linier orde dua pada (18). perbandingan hasil pengukuran dan simulasi model ditampilkan pada gambar 9 (c). estimator non linier yang digunakan pada penelitian ini adalah estimator non linier wavenet 75 unit, dan model yang diperoleh adalah model parametrik arx non linier orde 2 dengan regressor standar [y1(t-1); y(t-2); u1(t-1); u1(t2); u2(t-1); u2(t-2)]. hasil simulasi identifikasi dengan model non linier pada gambar 9 (b) menunjukkan bahwa model nonlinier yang diperoleh dapat mewakili karakteristik sistem. akan tetapi, model non linier membutuhkan komputasi yang rumit dan kurang efisien ketika digunakan pada aplikasi praktis. untuk mendapatkan model yang dapat digunakan untuk aplikasi praktis, maka dilakukan linierisasi pada model non linier yang diperoleh. linierisasi model hasil identifikasi dapat dilakukan dengan menggunakan fungsi linierisasi linapp pada system identificatiaon toolbox matlab. fungsi linapp pada dasarnya meminimalkan mean square error pada batasan data tertentu. dengan menggunakan data validasi sebagai batasan, proses linierisasi menghasilkan model arx linier orde dua pada (18). perbandingan hasil pengukuran dan simulasi model ditampilkan pada gambar 9. 0,9981 1 0,003888 4 2,405 1,531 1 0,7859 2 0,0809 3 (17) 1,337 1 0,399 2 1,123 1 1,118 2 4,127 1 4,134 2 (18) iv. hasil dan pembahasan a. validasi model dengan kriteria model yang didapat dari operasi loop terbuka divalidasi dengan menggunakan kriteria best fit, loss function, dan fpe. % best fit menunjukkan derajat kesesuaian antara respon model dengan keluaran terukur. loss function memberikan nilai determinan dari matriks covariance kesalahan. semakin kecil loss function berarti model yang diperoleh semakin baik. fpe merupakan indikator identifikasi sistem yang dihitung dari loss function, banyak parameter dan banyak data yang digunakan. berdasarkan hasil validasi model yang doperoleh, dapat diamati bahwa model arx non linier menghasilkan nilai best fit yang paling baik, namun untuk tujuan kontrol, model hasil linierisasi dengan nilai best fit 78,18% sudah cukup baik untuk digunakan dengan catatan kisaran kerja kontrol berada di sekitar data validasi yaitu nilai rasio kelebihan oksigen 15 30. b. rasio kelebihan oksigen perhitungan nilai rasio kelebihan oksigen pada kondisi operasi normal menggunakan pengontrol standar ditunjukkan pada gambar 10. dapat diamati pada gambar tersebut bahwa terdapat rentang waktu dimana nilai rasio kelebihan oksigen 4 yang merupakan nilai kritis. hal ini dapat mengakibatkan fenomena kelaparan oksigen yang akan berdampak pada kerusakan permanen membran fuel cell, dan mengurangi umur pakai fuel cell. berdasarkan gambar 5(e)-(g) dapat diamati bahwa pengontrol standar hanya bekerja berdasarkan temperatur (a) (b) (c) gambar 9. hasil pengukuran dan simulasi; (a) model arx; (b) model arx non linier; (c) model arx linier hasil linierisasi. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 47 stack dan tidak memperhitungkan rasio kelebihan oksigen dalam operasinya. fan hanya akan bekerja apabila temperatur meningkat. dengan demikian, perancangan pengontrol yang baru pada sistem fuel cell dapat dilakukan untuk mengatur rasio kelebihan oksigen demi mencegah kerusakan membran stack dan memperpanjang umur pakai stack. v. penutup a. kesimpulan pada makalah ini telah disampaikan metode sistematis perancangan platform loop terbuka sistem pem fuel cell horizon h-1000 yang dapat dikembangkan untuk penelitian selanjutnya. hasil percobaan dan analisis menunjukkan bahwa nilai rasio kelebihan oksigen sangat dipengaruhi oleh tekanan parsial oksigen pada katode. berdasarkan beberapa percobaan identifikasi, didapatkan beberapa model-model polinomial. • model arx linier orde 4 dengan nilai best fit 56,26% (loss function = 0,0159, fpe = 0,0159), • model arx non linier orde 2 dengan estimator wavenet 75 unit dengan nilai best fit 84,95% (loss function = 0,0139). • model hasil linierisasi arx non linier orde 2 dengan nilai best fit = 78,18% (loss function = 0,0009, fpe = 0,0009). b. penelitian selanjutnya penelitian selanjutnya dapat dilakukan dengan penambahan instrumen pengukuran (misalnya hydrogen mass flow meter) agar model yang diperoleh lebih akurat. di samping itu, penelitian dapat dilanjutkan untuk merancang sistem kontrol rasio kelebihan oksigen berdasarkan model yang diperoleh. referensi [1] j. t. pukrushpan, modeling and control of fuel cell systems and fuel processors, ph. d. thesis, the university of michigan, ann arbor, michigan, 2003. [2] j. pukrushpan, a. g. stefanopoulou, and h. peng, “control of fuel cell breathing,” ieee contr. syst. mag., vol. 24, no. 2, pp. 30-46, 2004. [3] j. del real, a. arce, and c. bordons, “development and experimental validation of a pem fuel cell dynamic model,” j. power sources, vol. 173, no. 1, pp. 310-324, 2007. [4] j. pukrushpan, a. g. stefanopoulou, s. varigonda, j. eborn, and c. haugstetter, “control-oriented model of fuel processor for hydrogen generation,” control eng. pract., vol. 14, no. 3, 2006, pp. 277-293. [5] y.-p. yang, f.-c. wang, h.-p. chang, y.-w. ma, and b.-j. weng, “low power proton exchange membrane fuel cell system identification and adaptive control,” j. power sources, vol. 164, no. 2, pp. 761-771, 2007. [6] j. k. gruber, m. doll, and c. bordons, “design and experimental validation of a constrained mpc for the air feed of a fuel cell,” control eng. pract., vol. 17. no. 8, 2009, pp. 874-885. [7] d.t. santa rosa, d.g. pinto, v.s. silva, r.a silva, and c.m. rangel, “high performance pemfc stack with opencathode at ambient pressure and temperature conditions,” int. j. hydrogen energ., vol. 32, pp. 4350-4357, 2007. [8] h. liu, f. d. coms, j. zhang, h. a. gasteiger, and a. b. laconti, “chemical degradation: correlation between electrolyzer and fuel cell findings;” polymer electrolyte fuel cell durability, springer science, 2009. [9] f. gasser, an analytical, control-oriented state space model for a pem fuel cell (a) (b (c) gambar 10. rasio kelebihan oksigen pada operasi normal dengan pengontrol standar; (a) tegangan kipas; (b) arus stack; (c) rasio kelebihan oksigen. e. leksono et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 39-48 48 system, master thesis, école polytech nique fédérale de lausanne, 2006. [10] f. barbir, pem fuel cells theory and practice, elsevier academic press, 2005. [11] r. o’hayre, s. w. cha, w. colella, and f. b. prinz, fuel cell fundamental, wiley, 2009. [12] l. ljung, system identification toolbox user‘s guide, mathworks, 2010. [13] a. su, “experimental investigation of the performance of a single proton exchange membrane fuel cell using dry fuel,”exp. heat transfer, vol. 16, 2003, pp.97-109. [14] j. m. hoy, convection-type pem fuel cell control system performance testing and modeling, master thesis, west virginia university, west virginia, 2008. [15] y. tang, w. yuan, m. pan, j. li, g. chen, and y. li, “experimental investigation of dynamic performance and transient responses of a kw-class pem fuel cell stack under various load changes,” appl. energ.,vol. 87, pp. 1410-1417, 2010. [16] l. ljung, system identification: theory for the user, prentice hall, new jersey, 1999. [17] r. johansson, system modeling and identification, prentice hall international ed., new jersey, 1993. [18] j. larminie and a. dicks, fuel cell system explained: second ed., j. wiley & sons, west sussex, uk, 2003. [19] horizon fuel cell technologies, h-1000 fuel cell stack: user manual v. 1.3, 2009 microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 19 analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik pudji irasari, aditya sukma nugraha, muhamad kasim puslit tenaga listrik dan mekatronik lipi komplek lipi, jl.cisitu no.21/154d bandung 40135 tel: 022-250-3055; fax: 022-250-4773 pudj002@lipi.go.id; adit003@lipi.go.id; kasime99uh@yahoo.co.id diterima: 18 agustus 2010; direvisi: 23 agustus 2010; disetujui: 30 september 2010; terbit online: 10 oktober 2010. abstrak getaran pada generator merupakan faktor yang penting dalam pembuatan detail desain. untuk mengetahui perilaku getaran yang terjadi, pengetesan dilakukan dengan vibratiometer. tujuan penulisan makalah ini adalah untuk memperoleh acuan klasifikasi getaran yang sesuai dengan standar iec 34-14 dan din en 60034-14. dalam tulisan ini respon hasil pengujian yaitu kecepatan dan percepatan akan diukur secara analitik sehingga mampu memunculkan nilai yang bisa dipakai untuk membandingkan antara nilai hasil pengujian dengan nilai pada standar iec 34-14 dan din en 60034-14. kata kunci : generator, getaran, kecepatan, percepatan. abstract vibration in a generator is an important factor in detail of design. to know the behavior of the vibration, a test is performed using vibratiometer. the aim in writing this paper is to obtain reference classification of vibration that can be viewed on a standard iec 34-14 and din en 60034-14. in this paper the results of testing, the value of velocity and acceleration, will be measured analytically so as to create value that can be used to compare the value of the test results with the value from 34-14 iec and din en 60034-14 standards. keywords: generator, vibration, kecepatan, percepatan. i. pendahuluan suatu benda yang diam apabila dibebani oleh suatu gaya akan menimbulkan gerakan sekitar titik setimbang. getaran akibat beban dinamis yang diterima oleh mesin apabila dilakukan dengan rutin dan dengan periode yang lama akan menimbulkan getaran siklis yang dapat menyebabkan kelelahan pada material [1]. getaran dalam gerakan melingkar yang terjadi pada mesin putar memang tidak bisa dihindari, tetapi dengan pengujian besar getaran yang terjadi, akan dapat diketahui getaran tersebut menyebabkan kerusakan atau tidak. a. latar belakang masalah penyebab umum getaran pada mesin putar adalah pembebanan dinamis dan kelonggaran. pembebanan dinamis terjadi apabila mesin putar dipakai dalam waktu yang relatif lama. hal ini akan mempengaruhi struktur komponen yang lain misalnya, fondasi mesin, karena tata letak geometris dari fondasi akan ikut menentukan besaran getaran yang akan diterima oleh mesin tersebut. disamping itu apabila dilakukan pembebanan yang rutin maka bentuk serta ikatan fondasi dengan tanah akan menentukan besar getaran yang akan diterima oleh mesin [1]. tingkat toleransi kelonggaran pada mesin juga memegang peranan yang penting dalam desain suatu alat. menurut studi yang dilakukan, bahwa cacat dan kelonggaran bantalan merupakan penyebab tersering kerusakan pada motor induksi [2]. disamping itu kelonggaran bantalan juga dapat disebabkan oleh kelelahan siklis dari komponen tersebut, yaitu kelelahan material akibat tegangan geser yang bekerja secara siklis [3]. selain kesalahan mekanis pada generator terdapat beberapa kasus yang bisa menyebabkan gerakan putar pada generator menjadi tidak seimbang dan kacau. penyebabnya antara lain adalah tingginya arus yang mengalir maupun gangguan elektrik lainnya, yang bisa menyebabkan kekacauan pada sistem. apabila kesalahan ini dibiarkan dalam jangka waktu yang lama, akan menyebabkan hilang daya, bergesernya orbit putar sehingga menyebabkan putaran mesin lebih berat [4]. secara awam getaran bisa dilihat dan dirasakan, akan tetapi analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik (pudji irasari, aditya sukma nugraha, muhamad kasim) pp. 19-26 20 untuk mendeteksi besaran getaran yang terjadi, diperlukan analisis numerik dari beberapa parameter yang diambil. b. latar belakang iptek hasil pada pengujian akan dibandingkan dengan standar yang ada yaitu pada standar iec 34-14 dan din en 60034-14. standar ini dipakai karena merupakan acuan internasional batas nilai getaran pada mesin putar elektrik. pada standar iec 34-14 dijelaskan tentang besaran nilai getaran yang diijinkan untuk pengujian mesin tanpa suspensi, pegas maupun tanpa landasan yang bersifat elastis [5]. pada standar ini maksimum ketinggian poros mesin putar yang akan diukur adalah 630 mm, sedangkan pada generator adalah 151 mm, sehingga generator yang diuji termasuk dalam kriteria tabel 1 dibawah ini. pada iec 34-14 ada tiga level pengujian, yaitu: normal (n) untuk mesin putar secara umum, reduced (r) untuk mesin putar yang perlu ketelitian seperti mesin bor maupun mesin milling dan yang terakhir special (s) untuk mesin putar yang memerlukan ketelitian yang tinggi, misalnya mesin gerinda dan mesin balance. dalam hal ini generator yang diuji masuk ke dalam level normal [4]. tabel 1. maksimum kecepatan getaran yang diijinkan berdasar standar iec 34-14. grade rated speed (rpm) maximum r.m.s values of vibration velocity (mm/s) machine measure in a state of free suspension 56≤h<132 132≤h<225 225≤h<400 400≤h<630 n 600≤n≤1800 1800<n≤3600 1.8 1.8 1.8 2.8 2.8 4.5 2.8 4.5 r 600≤n≤1800 1800<n≤3600 0.71 1.12 1.12 1.8 1.8 2.8 s 600≤n≤1800 1800<n≤3600 0.48 0.71 0.71 1.12 1.12 1.8 disamping tabel iec 34-14 diatas, tulisan ini juga membandingkan antara hasil percobaan pengambilan data getaran generator dengan standar din en 60034-14, seperti yang terlihat pada tabel 2 dibawah ini. pada standar ini pembacaannya mirip dengan standar iec 34-14, hanya untuk spesifikasi frekuensi getaran antara 10 – 1000 hz [6]. tabel 2. batas maksimum kecepatan getaran yang diijinkan berdasar standar din en 60034-14. grade rated speed (rpm) limits of vibration velocity (mm/s) in frequency range 10 up to 1000 hz sizes 80-112 132-200 225-400 n 600-3600 1.8 2.8 3.5 r 600-1800 1800-3600 0.71 1.12 1.12 1.8 1.8 2.8 s 600-1800 1800-3600 0.45 0.71 0.71 1.12 1.12 1.8 c. tujuan penelitian tujuan dalam penulisan makalah ini adalah untuk memperoleh acuan klasifikasi getaran yang sesuai dengan standar iec 34-14 yang ada pada tabel 1 [5] dan din en 60034-14 [6] yang ada pada tabel 2. ii. metodologi penelitian a. objek penelitian generator yang akan diuji adalah generator magnet permanen. generator ini banyak dipilih oleh pengguna, karena memiliki beberapa kelebihan, antara lain adalah biaya produksinya murah, magnet dapat dibuat sesuai dengan cetakan yang dinginkan, memiliki sifat magnet yang seragam, dan kerugian arus edy yang kecil [7]. secara garis besar, generator memiliki 2 komponen utama, yaitu stator dan rotor. stator yang dibuat terdiri dari beberapa coil atau kumparan dari kawat tembaga yang dilapisi oleh bahan isolator, sedangkan rotor terdiri dari poros pemutar. dimensi dan parameter utama yang digunakan pada generator disajikan dalam tabel 3 di bawah ini. tabel 3. parameter pada generator. parameter nilai tegangan fasa nominal 169,7 volt frekuensi nominal 50 hz putaran nominal 333 rpm jumlah fasa 3 fasa kisar lilitan penuh 1 kerapatan arus 5 a/mm2 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 21 parameter nilai kerapatan fluks 1 tesla permeabilitas relatif magnet 1,1 jumlah koil /kutub f asa 1 lebar celah udara 1 mm jumlah alur stator 54 alur radius dalam stator 0,0738 m radius luar stator 0,17 m diameter luar stator 0,340 m panjang efektif stator 0,103 m lebar yoke stator 0,0412 m lebar bukaan alur stator 0,00288 m lebar gigi atas stator 0,00571 m lebar gigi stator 0,0045 m lebar alur stator 0,0112 m kedalaman alur stator 0,0226 m luas alur stator 111,93 m b. pengumpulan data berikut ini adalah urutan dalam pengumpulan data 1) persiapan alat pada proses pengumpulan data, ada beberapa alat yang perlu disiapkan, antara lain adalah fluke, stroboskop, dan juga vibratiometer. terlebih dahulu sebelum dilakukan pengambilan data, semua komponen dirakit dengan baik, seperti misalnya pemasangan pulley pada motor penggerak diatur kelurusan dan kekencangannya sehingga tidak terjadi kerugian yang tidak perlu. selanjutnya semua benda uji dan alat uji akan tersusun seperti yang terlihat pada gambar 1 dibawah ini. gambar 1. metode pengukuran respon getaran. 2) pengukuran variasi kecepatan pertama, motor penggerak diatur kecepatan putarnya sedemikian rupa sehingga putaran yang dihasilkan oleh generator sesuai dengan kecepatan putar yang diinginkan, yaitu kelipatan 100 rpm sampai dengan 600 rpm. 3) pengukuran respon getaran dalam hal ini respon getaran akan diukur dengan vibratiometer pada tiga titik sumbu pada permukaan luar generator, seperti yang terlihat pada gambar 2. titik yang diambil data adalah arah horizontal, vertikal, dan axial. pengumpulan data getaran berisikan variasi arah pengukuran pada saat tanpa beban maupun dengan pembebanan. dimana data keluaran yang akan dicatat adalah kecepatan dan percepatan, data yang diambil adalah rata-rata nilai dari beberapa kali percobaan.   vibration  meter data hasil  pengukurann    gambar 2. diagram pengambilan data. iii. hasil pengujian struktur geometri komponen yang ada pada generator akan sangat mempengaruhi bentuk gelombang dan amplitudo. desain generator yang diuji terdiri dari komponen utama yaitu poros pemutar dan rotor seperti ditunjukkan pada gambar 3 dibawah ini.   θ&&j θ&&jkt gambar 3. skema susunan pada generator pada gerak harmonik persamaannya yang standar adalah sebagai berikut : analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik (pudji irasari, aditya sukma nugraha, muhamad kasim) pp. 19-26 22 θ = a sin ωt (1) θ& = a cos ωt (2) θ&& = -ω2 a sin ωt (3) dimana θ adalah jarak getaran, θ& adalah kecepatan getaran, θ&& adalah percepatan getaran, dan a adalah amplitudo getaran. skema pada gambar 3 menunjukkan bahwa komponen putar yang bekerja adalah poros dan rotor. dimana kekakuan pada poros (nm/rad) adalah kt = ip l g (4) momen inersia polar penampang pada poros adalah ip = l gd 32 4π (5) adapun d adalah diameter poros, g adalah modulus elastis geser pada poros, dan l adalah panjang poros uji. dari persamaan (4) dan (5) didapat persamaan kt = l gd 32 4π (6) frekuensi pribadi yang terjadi didalam sistem adalah ωn= )( 21 jj kt + (7) adapun j1 = j2 yaitu inersia rotor 1 dan 2. dikarenakan dalam sistem terdapat medan magnet yang cukup besar, maka terdapat redaman getaran yang terjadi. akibat terjadi redaman, pengurangan algoritma (δ ) akibat beda amplitudo yang terjadi saat kecepatan generator 600 rpm adalah 2 1ln y y =δ (8) dimana y1 adalah puncak amplitudo 1 dan y2 adalah puncak amplitudo 2. setelah itu akan didapat nilai rasio redaman (ξ ) yang terjadi sebesar π δ ξ 2 = (9) sehingga dari persamaan diatas didapat nilai frekuensi teredam sebesar ξωω −= 1nd (10) sehingga apabila dikonversi dalam bentuk hertz akan didapat π ω 2 df = (11) sehingga tabel hasil perhitungan dari persamaan diatas adalah sebagai berikut. tabel 4. hasil perhitungan keterangan nilai kekakuan poros (kt) 196782,84 (nm/rad) frekuensi pribadi (ωn) 4679,49 (rad/det) pengurangan algoritma akibat redaman (δ) 0,46 rasio redaman (ξ) 0,74 frekuensi teredam (ωd) 4503,18 (rad/det) frekuensi teredam (f ) 717,067 (hz) nilai frekuensi getaran pada sistem adalah 717,067 hz, sehingga hal ini menunjukkan standar din en 60034-14, dapat dipakai dalam sistem ini. a. pengujian tanpa beban pengukuran pertama dilakukan kondisi generator tanpa dibebani. hasil pengukuran getaran pada generator saat tanpa beban dapat dilihat pada tabel 5 dibawah ini. tabel 5. hasil pengukuran respon getaran tanpa beban ω (rpm) kecepatan (mm/s) percepatan (mm/s2) x y z x y z 100 0,6 0,5 0,5 0,5 0,5 0,5 200 0,3 0,2 0,5 0,2 0,5 0,3 300 0,3 0,2 0,2 0,5 0,4 0,2 400 0,7 0,7 0,6 1,2 1,1 1,6 500 2 1,2 2,5 1,1 0,9 1,6 600 2,9 2,2 3,5 0,5 0,4 0,7 harga respon pada tabel 5 diatas merupakan hasil yang didapat dari pengukuran secara langsung. kecepatan akan terlihat dengan karakteristik kurva sebagai berikut. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 23 gambar 4 kurva rpm vs kecepatan seperti yang terlihat pada gambar 4, pada pengamatan respon getaran untuk pengukuran kecepatan diketahui bahwa titik tertinggi terdapat pada pengukuran arah sumbu z, dengan kecepatan putar 600 rpm (axial), yaitu sebesar 3,5 mm/s. sedangkan titik paling rendah terdapat pada sumbu y dan sumbu z yaitu sebesar 0,2 mm/s. harga respon pada tabel 5 untuk pengukuran percepatan (mm/s2), memiliki karakteristik seperti ditunjukkan oleh kurva pada gambar 5 dibawah ini. gambar 5. rpm vs percepatan seperti yang terlihat pada gambar 5, pada pengamatan respon getaran untuk pengukuran percepatan diketahui titik tertinggi terjadi pada sumbu z pada kecepatan 400 rpm dan 500 rpm yaitu sebesar 1,6 mm/s2. sedangkan titik paling rendah sebesar 0,2 mm/s2. dengan melihat bahwa besar amplitudo adalah a = tsinω θ (12) maka untuk arah axial, vertikal, maupun horizontal didapat nilai amplitudo torsional dan jarak seperti ditunjukkan pada tabel 6. tabel 6. hasil pengukuran jarak respon getaran tanpa beban ω (rpm) amplitudo torsional (mm) jarak (mm) ax ay az θx θy θz 100 0,6 0,5 0,5 4,7 x 10-2 4,8 x 10-2 4,7 x 10-2 200 0,3 0,2 0,5 9,5 x 10-3 2,4 x 10-2 1,4 x 10-2 300 0,3 0,2 0,2 1,5 x 10-2 1,3 x 10-2 6,3 x 10-3 400 0,7 0,7 0,6 2,8 x 10-2 2,6 x 10-2 3,8 x 10-2 500 2 1,2 2,5 2,1 x 10-2 1,7 x 10-2 3,0 x 10-2 600 2,9 2,2 3,5 7,9 x 10-3 6,3 x 10-3 1,1 x 10-3 dari hasil pengukuran di dapat nilai tertinggi jarak respon getaran tanpa beban sebesar 4,8 x 10-2 mm yaitu pada arah sumbu y. gambar 6 dibawah ini adalah karakteristik kurva hasil pengukuran jarak respon getaran tanpa beban. gambar 6. rpm vs jarak seperti yang terlihat pada gambar 6, pada pengamatan respon jarak getaran nilai yang diperoleh bervariasi, hanya saja setelah melewati kecepatan 400 rpm terdapat kecenderungan bahwa nilai jarak getaran (mm) menurun. b. pengujian dengan beban 300 w pengukuran kedua dilakukan pada kondisi dimana generator diberi beban sebesar 300 w. pembebanan dilakukan berdasarkan kapasitas maksimum pembebanan yang mampu dilakukan di laboratorium elektronika daya pusat penelitian tenaga listrik dan mekatronik lipi yaitu 300 w. hasil pengukuran getaran pada generator saat diberi beban sebesar 300 w dapat dilihat pada tabel 7 dibawah ini. 0 0,5 1 1,5 2 2,5 3 3,5 4 0 100 200 300 400 500 600 kurva rpm vs kecepatan sumbu x  sumbu y sumbu z 0 0,5 1 1,5 2 0 100 200 300 400 500 600 rpm vs percepatan sumbu x sumbu y sumbu z 0 0,01 0,02 0,03 0,04 0,05 0 100 200 300 400 500 600 rpm vs jarak sumbu x sumbu y sumbu z analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik (pudji irasari, aditya sukma nugraha, muhamad kasim) pp. 19-26 24 tabel 7. hasil pengukuran respon getaran dengan beban 300 w. ω (rpm) kecepatan (mm/s) percepatan (mm/s2) x y z x y z 100 0,4 0,4 0,6 0,6 0,6 0,7 200 0,3 0,8 0,4 1,4 1,3 1,1 300 0,8 0,5 0,6 0,1 0,3 0,4 400 0,9 0,9 0,4 2,8 2,1 1,3 500 0,8 0,3 0,5 1,1 0,9 0,4 600 0,9 0,4 0,5 1,3 0,9 0,4 harga respon pada tabel 7 diatas merupakan hasil yang didapat dari pengukuran secara langsung kecepatan, dengan karakteristik sebagai berikut. gambar 7. rpm vs kecepatan pada pengamatan pada gambar 7 ukuran kecepatan akan diketahui titik paling tinggi terdapat pada pengukuran arah sumbu x pada putaran 400 rpm dan 600 rpm yaitu sebesar 0,9 mm/s. sedangkan titik paling rendah terjadi pada sumbu x pada kecepatan putar 200 rpm yaitu sebesar 0,3 mm/s. sedangkan harga respon pada tabel 7 untuk pengukuran percepatan, mempunyai karakteristik seperti ditunjukkan pada kurva pada gambar 8 dibawah ini. gambar 8. rpm vs percepatan seperti yang terlihat pada gambar 8, pada pengamatan respon getaran untuk pengukuran percepatan diketahui mempunyai titik paling tinggi terjadi pada sumbu x pada putaran 400 rpm yaitu sebesar 2,8 mm/s2. sedangkan titik paling rendah terjadi pada sumbu x pada kecepatan putar 300 rpm yaitu sebesar 0,1 mm/s2. bila amplitudo untuk jarak, kecepatan dan percepatan dianggap sama, maka tsintcostsin ωω θ ωω θ ω θ 2 &&& == (13) sehingga tcos tsin ω ωω θ θ = & && (14) maka untuk arah axial, vertikal, maupun horizontal didapat nilai amplitudo torsional dan jarak seperti tabel 8 dibawah ini. tabel 8. hasil perhitungan jarak respon getaran dengan beban 300 w ω (rpm) amplitudo torsional (mm) jarak (mm) ax ay az θx θy θz 100 0,4 0,4 0,6 5,7 x 10-2 5,8 x 10-2 6,69 x 10-2 200 0,3 0,8 0,4 6,66 x 10-2 6,2 x 10-2 5,2 x 10-2 300 0,8 0,5 0,6 3,2 x 10-3 9,5 x 10-3 1,3 x 10-2 400 0,9 0,9 0,4 6,66 x 10-2 5 x 10-2 3,1 x 10-2 500 0,8 0,3 0,5 2,1 x 10-2 1,7 x 10-2 3,8 x 10-3 600 0,9 0,4 0,4 2,1 x 10-2 1,4 x 10-2 3,2 x 10-3 seperti yang ditunjukkan pada tabel 8, hasil pengukuran menunjukkan bahwa nilai tertinggi dan nilai terendah jarak respon getaran dengan beban 300 w terdapat pada sumbu z. nilai tertinggi sebesar 6,69 x 10-2 mm yang terletak pada arah sumbu z, dengan kecepatan putar 100 rpm. sedangkan titik paling rendah juga terdapat pada sumbu z pada kecepatan 600 rpm yaitu sebesar 3,2 x 10-3 mm. 0 0,2 0,4 0,6 0,8 1 0 100 200 300 400 500 600 rpm vs kecepatan sumbu x sumbu y sumbu z 0 0,5 1 1,5 2 2,5 3 0 100 200 300 400 500 600 rpm vs percepatan sumbu x sumbu y sumbu z journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 25 harga respon getaran dengan beban 300 w yang ditunjukkan pada tabel 8 memiliki karakteristik seperti ditunjukkan oleh kurva pada gambar 9 dibawah ini. gambar 9. rpm vs jarak seperti yang terlihat pada gambar 9, hasil pengamatan menunjukkan bahwa jarak respon getaran mempunyai nilai yang bervariasi. hanya saja setelah kecepatan putar generator mencapai 400 rpm terjadi kecenderungan nilai jarak respon getaran menurun. iv. kesimpulan a. kesimpulan adapun kesimpulan dari hasil pengamatan dan perhitungan pada penelitian ini ditunjukkan pada poin-poin berikut : 1. hasil pengukuran respon kecepatan getaran secara langsung untuk generator tanpa beban nilai tertinggi pada arah sumbu z yaitu sebesar 3,5 mm/s, sedangkan untuk pengukuran percepatan tertinggi pada arah sumbu z yaitu sebesar 1,6 mm/s2. 2. hasil pengukuran kecepatan respon getaran secara langsung untuk generator dengan beban 300 w, nilai tertinggi pada arah sumbu x yaitu sebesar 0,9 mm/s, sedangkan untuk pengukuran percepatan tertinggi pada arah sumbu x yaitu sebesar 2,8 mm/s2. 3. hasil perhitungan jarak untuk generator tanpa beban nilai tertinggi dengan nilai 4,8 x 10-2 mm pada arah sumbu y , sedangkan pengukuran untuk generator dengan pembebanan 300 w adalah dengan nilai 6,69 x 10-2 mm pada arah sumbu z. 4. berdasarkan tabel iec 34-14 dan din en 60034-14 pada putaran 600 rpm, kecepatan getaran yang diijinkan adalah 1,8 mm/s, sehingga hasil pengujian getaran pada generator tanpa beban, nilai kecepatan paling besar adalah 3,5 mm/s, menunjukkan bahwa dalam kondisi tanpa pembebanan generator tersebut belum memenuhi kualifikasi yang tertera pada standar iec 34-14. 5. pada hasil pengujian respon kecepatan getaran pada generator dengan pembebanan 300 w, hasilnya relatif lebih kecil dan stabil dari pengujian generator tanpa pembebanan yaitu 0,9 mm/s. b. saran penulis menyarankan untuk melakukan riset lanjutan yang lebih terfokus untuk meneliti tentang variabel yang menyebabkan besarnya nilai kecepatan getaran pada generator tanpa pembebanan melebihi standart yang ditentukan, misalnya kelonggaran komponen ataupun keausan komponen generator. daftar pustaka [1] prakash, s., puri, v, 2006, “foundation for vibrating machines”, the journal of structural engineering, serc, madras, india april-may. [2] smeisme, a., saklawi, r., and yassine, w., 2008, “a predictive maintenance tool: vibration analysis to determine the condition of electric machines”, ariser vol. 4 no. 3 (2008) 103-117, electrical and computer department, american university of beirut, lebanon, 23 june 2008. [3] jayaswal, p, wadhwani, a., and. mulchandani, b., 2008, “machine fault signature analysis”, hindawi publishing corporation international journal of rotating machinery volume 2008, 21 january. [4] oliquino, r., islam, s., and eren, h., 2002, “effects of types of faults on generator vibration signatures”, school of electrical and computer engineering curtin university of technology, western australia. [online]. available: www.itee.uq.edu.au/~aupec/aupec03/.../00 8%20oliquino%20paper.pdf. [5] setimi, a., 2010, “ electric motor vibration”, australia. [online]. available: http://www.weg.com.br. [6] energy-efficient motors according to iec/din high efficiency motors according to epact. for low voltage with squirrelcage rotor, 1999, [online]. available: www.mahykhoory.com/pdf/w21r_e.pdf. [7] irasari, pudji dan hidayati, d, nurafni, , 2006, “analisis prototipe generator kecepatan rendah untuk pembangkit listrik skala kecil”, majalah teknologi indonesia volume 29, nomor 1 2006: pp 47-51. 0 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0 100 200 300 400 500 600 rpm vs jarak sumbu x sumbu y sumbu z analisis getaran pada generator magnet permanen 1 kw hasil rancang bangun pusat penelitian tenaga listrik dan mekatronik (pudji irasari, aditya sukma nugraha, muhamad kasim) pp. 19-26 26 [8] c.b. williams, a. pavic, r.s. crouch, r.c. woods. “feasibility study of vibration-electric generator for bridge vibration sensors”, imac-xvi proceedings, sheffield, united kingdom, 1997. [9] hariyotejo, p., helian, j., pramono, g., ridwan, a., 2008, “pengembangan generator mini dengan menggunakan magnet permanen”, departemen teknik mesin, program pasca sarjana, fakultas teknik universitas indonesia, jakarta, indonesia. [online]. available: images.sudarjanto.multiply.com /.../pengembangan-generator-mini-denganmenggunakan-magnet-permane1.pdf. mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.189-200 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: m. nazih, “effect of lightning mast placement on underground power cable jacket stress within high voltage substations,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 189-200, dec. 2022. effect of lightning mast placement on underground power cable jacket stress within high voltage substations mostafa nazih * future energy, ghd pty ltd 999 hay st., perth, wa 6000, australia received 13 july 2022; 1st revision 23 september 2022; 2nd revision 24 october 2022; 3rd revision 27 october 2022; accepted 31 october 2022; published online 29 december 2022 abstract this study aims to investigate the impact of lightning masts placement on underground cables within high voltage substations. while the subject of lightning discharges near to underground cables has been covered with open cable runs and wind farms in many papers, this study focuses on lightning events within high voltage substations considering the associated effective zones, which were not covered in the available literature. substations built within areas prone to high lightning activity experience frequent discharges that cause the potential rise of the earthing system into hundreds of kilovolts. the potentials propagating within the soil and the earthing grid affect underground cables jackets terminated within the substation. the numerical analysis of the problem is carried out using current distribution, electromagnetic fields, grounding and soil structure analysis (cdegs) software engine for different configurations of lightning mast placements with varied separation, electrode placement and length, soil resistivity, and lightning current. study findings indicate that provision of lightning masts/down conductors as far as possible or at least twice the effective zone radius from cable termination/route electrodes ensures relatively lower stress voltages. electrodes with effective zone radius length placed as close as possible to lightning masts further reduce the attainable jacket stress voltages. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: substation earthing; lightning mast placement; high voltage; underground cable; effective zone radius. i. introduction lightning protection air terminations represent a vital part of high voltage substation switchyards [1]. many models are available to design the lightning protection systems based on various formulae for lightning stroke current and associated rolling sphere radius [2]. during a lightning stroke discharged into the substation earthing system, the soil will have a transient potential gradient within the substation and nearby [1]. the gradient causes underground cable jacket stress that can exceed its insulation strength and cause a breakdown of the jacket compromising its integrity and the cable lifetime [1]. the lightning protection systems intercepting lightning strokes exceeding the design current help rationalising the surge arrestors selection by diverting stroke currents to the substation earthing system. a traditional sphere radius of 24 m is used, which corresponds to a stroke design current of about 4.2 ka based on the electrogeometric method (egm) [2]. some other utilities suggest a sphere radius of 43 m corresponding to 10 ka striking current, which is in line with the rated discharge current of most station type surge arrestors. the rationale behind that is to allow surges less than 10 ka to penetrate the shielding system, given these surges will be neutralised by surge arrestors typically installed near to important equipment within the substation. surges higher than 10 ka will be intercepted by the lightning protection system and diverted to earth. typical locations for surge arrestors within high voltage switchyards are line entries, power transformers, and cable sealing ends. the impact of lightning discharges on underground cables has been studied extensively with respect to testing, open runs, and wind farms. gomes et al. [3] have used atp modelling to study the lightning discharge impact on cable sections terminated to towers near substations with special * corresponding author. tel: +61-490181939 e-mail address: mostafa0020@yahoo.com https://dx.doi.org/10.14203/j.mev.2022.v13.189-200 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.189-200 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.189-200&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 190 focus on the frequency dependency of soil and towers earthing systems. it has used a lumped impedance representing the earthing grid instead of detailed modelling for the grid. narajo-villamil et al. [4] studied lightning induced surges in underground cables with focus on building reinforcements and internal earthing. arshad et al. [5] listed a study on lightning effects on 132 kv underground cables using atp but without considering substation earthing systems. cao et al. [6] studied the effect of lightning strikes on sheath voltage limiters in open run applications. tanaka et al. [7] document a detailed study on the use of buried shield wires to improve the open run underground cable lightning performance considering the diversion of surges from the cable. kangro et al. [8] detailed different modelling approaches on cable sheath representation and the effect of lightning high frequency components on results. wu et al. [9] presented a typical study on open run underground cable metallic sheath induced voltages due to lightning discharges with focus on soil stratification effects. aniserowicz et al. [10] documented a comparative study between cdegs modelling and semi-analytical approaches regarding lightning voltage and current distributions within an underground cable system. chen et al. [11] demonstrated site measurements of transferred surges through soil with rocket-triggered lightning strikes and associated response of surge arrestors. jiao et al. [12] listed experimental results for coaxial cables lightning response and associated coupling using an impulsive generator setup. güneri and alboyaci [13] analysed the accuracy and validity of different modelling techniques for high frequency lightning response with underground cables return impedance. shehab et al. [14] carried out a detailed lightning transient study of power transformers within a thermal power plant where the effects of lightning surges can be detrimental to equipment operation and cause excessive blackouts. liu et al. [15] proposed a new method to estimate the lightning induced voltages on overhead lines and single core underground cables open runs. sekioka [16] studied wind farm connected substation lightning overvoltage due to underground collector cable sheath propagation of surges impending at wind turbines. taha et al. [17] discussed the performance of a lightning protection system for a 110 kv substation within an urban area using cdegs software to estimate the touch and step voltages associated with lightning discharges into the substation earthing grid. sabiha et al. [18] studied the overvoltages and supply continuity associated with backflow lightning surges propagating through lightning protection air terminations of photovoltaic installations. aref and anaraki [19] studied the propagation of lightning surges through a transition between underground and overhead connections within sub-transmission substations. alipio et al. [20] studied the lightning surge propagation in mixed overhead-cable lines taking soil frequency dependency into consideration. q. liu et al. [21] investigated the lightning performance of weather stations and its effects on sheathed cables with requirements on separate lightning electrodes. goertz et al. [22] analysed the hvdc cables response to lightning strokes and stress variation along cable length and the impact on insulation coordination with different station earthing resistances. lennerhag et al. [23] developed a statistical method for estimating lightning overvoltages in hvdc cables and lines, considering shielding failure and backflashover scenarios. eriksson [24] researched the impact of lightning masts placement on low voltage cable insulation within substations without considering the jacket breakdown or the effective zone concept and the effect of other design parameters on attainable stresses. this paper studies cable jacket insulation impacted by discharges affecting high voltage substation earthing systems, with a focus on lightning mast location and earthing system modifications that were not covered in the available literature. the paper investigates the impact of the placement of lightning masts and down conductors within a substation on terminated underground cable jacket stress, taking into consideration the effect of varied separation, electrode placement and length, soil resistivity, and lightning current. ii. materials and methods a. lightning discharge and modelling lightning stokes show a probabilistic nature with current ranges from a few hundred amperes to about 200 ka [2]. several probability density functions had been developed to match field measurements from various countries and territories with variable median and exponent values [1][2]. the general form of the density function is given by equation (1): 𝐏(𝐈𝐩) = 𝟏 𝟏+� 𝐈𝐩 𝐈𝟓𝟓 � 𝐱 (1) where, p(lp) is probability that any peak returnstroke in any given flash will exceed ip (ka), i50 is 50 % probability peak current, x is exponent, i is lightning peak current (ka). for this study, i50 is 24 ka and x is 2.6 are selected. hence, a typical stroke in any lightning flash is expected to follow the pattern in figure 1. the median indicates that 50 % of strokes crest current will exceed this value at any time. the typical probability distribution shows that high stroke currents are less probable but not impossible. the probabilistic nature of the lightning phenomenon is captured in this distribution, where strokes can vary along a very wide range of currents at the same location. around any calculation period, typically a few years, half of the strokes at a certain area will exceed the median value where the other half will be equal to or less than the median value. standard 1.2/50 μs current impulse is used to perform the studies. b. high voltage substation lightning protection switchyards are typically protected against lightning discharges by air terminations. this can be in the form of shield wires and/or, preferably, m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 191 lightning masts (lm), due to the risk associated with shield wires failure onto switchyard live conductors, as reported in [25]. the electrogeometric method (egm) [2] utilises a rolling sphere with a striking distance as its radius, depending on the striking current. the sphere indicates the areas that a stroke is probable to hit and air terminations are provided to intercept the strokes away from the protected equipment and conductors, as illustrated in figure 2 [26]. c. cable jacket insulation underground high and medium voltage cables are usually provided with a protective insulating jacket to block moisture and protect the cable from external damage. the jackets made of pvc or hd/ld pe are common. jackets are not designed to withstand high voltage stresses since the cable metallic sheaths are designed to have a limited potential with respect to soil outside cables [27]. accordingly, the breakdown of the jacket can cause a puncture pinhole, moisture migration and damage. lightning damage to cables has been reported in [28]. typical lightning impulse withstand voltages (bil) are provided in table 2 of [27]. given the cable jacket insulation is non-self-restoring, peak recorded values of non-standard waveforms obtained at the cable jacket shall be compared to jacket bil [29]. 60 kv is a typical value to consider for jacket withstand voltage for hv cables. although this value is indicative, higher values may be verified through testing. the jacket bil is an important factor to avoid breakdown and subsequent moisture damage. since most hv underground cables are laid directly in the ground due to cost and ampacity requirements, jacket thickness is not perfectly uniform along the cable due to possible abrasion during and after installation. the compromised jacket thickness will result in a lower bil due to a higher electric field within the jacket. another detrimental factor that affects the underground cable jacket is the presence of corrosive chemicals in the soil, which must be verified during the installation planning/design stage through soil chemical analysis. the latter is especially true for installations within industrial areas with contaminated soils. d. earthning grid performance with lightning discharge the impact of lightning discharges on substation earthing grids has been studied with several parameters (grid dimensions, conductor spacing, impulse feed point location, soil resistivity and ionization, wave front time and current amplitude) [1]. the critical or effective length concept is introduced to identify the phenomenon of limited lightning impulse propagation due to the dominant inductive effect at very high frequencies associated with lightning discharges. the critical length concept is extended into an effective zone with a radius re in metres given by equation (2) [1] for the centre feed point/lightning mast: 𝑟𝑒 = 0.34𝜌0.42𝑇0.32 (2) where ρ is soil resistivity in ω.m and t is the front time in μs. the effective zone radius indicates the zone of conductors contributing to lightning discharge dissipation. in other words, connected grid figure 1. probability of stroke current exceeding abscissa, 24 ka median value with 50 % exceedance probability is shown figure 2. lightning masts around hv switchyard and rolling sphere concept [26] m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 192 conductors and rods beyond this zone have insignificant effect on grid lightning response, contrary to the power frequency behaviour where additional conductors are typically contributing to reduce the grid resistance and attainable touch, step and transferred voltages. e. methodology the study uses state-of-the-art current distribution, electromagnetic interference, grounding and soil structure analysis (cdegs) software engine. the process is summarised by the flowchart in figure 3. the process starts with the initial modelling of the earthing grid and cable using cdegs high frequency analysis module (hifreq) software, as shown in figure 4. the software engine is based on the field theory method and uses the method of moments (mom) to solve maxwell’s equations in three dimensions. the software does not consider soil ionization [30], a phenomenon encountered with lightning discharges exceeding 100 ka resulting in increases conductive area around affected conductors, especially with concentrated designs. cdegs fast fourier transform module (fftses) is then used to perform the forward transform of the standard lightning impulse into periodic components with different frequencies, where the software calculates each frequency parameter separately. inverse fourier transform is used to recompile the frequency-domain results into time-domain results for attainable jacket stress variation with time. the process is repeated with the varied parameter as indicated in table 1 for each case and the maximum jacket stress results (magnitude and location along cable) are obtained through the fftses and plotted against the variable parameter. three main cases are studied in this paper, with parameters tabulated in table 1. details of each case are provided below. 1) case–i.1 the first case under study is for a typical hv substation earthing grid with overall dimensions of 100 x 100 m and 10 m uniform spacing, as shown in figure 4. the native soil resistivity is 100 ω.m. one 15 m lightning mast of typical steel construction and a 1.5 m spike above it is considered for impulse feed. figure 3. modelling flowchart m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 193 an underground cable terminated at the substation earthing grid and ran outside the substation grid for 1 km. cable sheath is bonded to the substation earthing grid at the termination point (cable sealing end). lightning current is set at the median value of 24 ka. the mast location is moved away from the cable/sheath termination point at the earthing grid and maximum jacket stress voltage is obtained accordingly. the earthing grid power frequency resistance is calculated as 0.46 ω. 2) case–i.2 the base design is modified with the addition of a vertical rod next to lm. the power frequency earthing resistance is not affected by the addition of a 2.5 m electrode at the lightning mast due to the extended grid area and uniform soil resistivity. 3) case–i.3 the base design is modified considering a practical spacing in outdoor high voltage substations for the lm and cable sealing end (cse) ≥ 4 m. the electrode depth is varied to identify the impact on attainable jacket stress. the power frequency earthing resistance is not affected by the increased electrode depth given the extended grid area. 4) case–i.4 the base design is modified considering a typical 2.5 m deep electrode used to check the effect of moving the electrode away from the lm. the power frequency earthing resistance is not affected by the increased electrode depth given the extended grid area. table 1. case study parameters case lightning current (ka) soil resistivity (ω.m) mast separation (m) electrode depth (m) electrode separation (m) effective zone radius (m) i.1 24 100 1:78 0 0 2.5 i.2 24 100 1:78 2.5 0 2.5 i.3 24 100 4 0:30 0 2.5 i.4 24 100 4 2.5 0:15 2.5 ii.1 24 500 1:78 0 0 4.9 ii.2 24 500 1:78 2.5 0 4.9 iii.1 120 100 1:78 0 0 2.5 iii.2 120 100 1:78 2.5 0 2.5 a) b) figure 4. 100 x 100 m, 10 m uniform spacing earthing grid, underground cable, and lightning mast cdegs hifreq model: (a) 3d view; (b) plan view with lm possible locations shown in blue dots and separation distances in metres as marked. cable chainage direction shown away from grid m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 194 5) case–ii.1 the soil resistivity is considered for this case as 500 ω.m with a similar setup as case – i. the earthing grid power frequency resistance is calculated as 2.31 ω. lightning current is set at the median value of 24 ka. 6) case–ii.2 the design is modified with the addition of a vertical rod next to lm. the power frequency earthing resistance is not affected by the addition of a 2.5 m electrode at the lightning mast due to the extended grid area and uniform soil resistivity 7) case–iii.1 the soil resistivity is considered for this case as 100 ω.m with similar setup as case – i but with the injection lightning current of 120 ka peak (5 x 24 ka) representing a value of stroke current with only 1.5 % exceedance probability (i.e., more than 98.5 % of lightning strokes will be less than 120 ka). the earthing grid power frequency resistance remains as 0.46 ω calculated in case-i. 8) case–iii.2 the design is modified with the addition of a vertical rod next to lm. the power frequency earthing resistance is not affected by the addition of a 2.5 m electrode at the lightning mast due to the extended grid area and uniform soil resistivity. iii. results and discussions a. results 1) case– i.1 results the attainable jacket stress voltage versus variable separation distance from the lightning mast is shown in figure 5. the attainable stress voltage typically decreases with distance away from the lm with little or no dependency on placement direction. the location of the maximum stress varies with mast separation and shows a tendency to move outside the substation grid with greater mast separation to the cable termination point. the cable stress voltage suffers a sharp decline beyond 5 m (i.e., twice the calculated effective zone radius). the behaviour follows the concept of effective length that beyond a certain distance along earthing conductor, the potential variation (and hence, resistance) is insignificant regardless of the additional connected conductors. 2) case– i.2 (modified design – addition of vertical rod next to lm) results the attainable maximum stress voltage and location is shown in figure 6. the attainable stress voltage typically decreases with distance away from the lm with little or no dependency on placement direction, similar to figure 5. electrode works to dissipate the lightning current at the lm more effectively away from the rest of the earthing grid. figure 5. peak jacket stress voltage and location variation vs. lm separation 0 10 20 30 40 50 60 70 80 0 20 40 60 80 100 120 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) figure 6. peak jacket stress voltage and location variation vs. lm separation 0 10 20 30 40 50 60 70 80 0 20 40 60 80 100 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 195 the effect is paramount with a separation distance of less than 5 m (twice the calculated effective zone radius) with a recorded maximum stress reduction of about 20 % compared to the case with no electrode. spacings greater than 5 m showed slightly higher stress voltages compared with the no electrode configuration (~2 %) then falls away (>15 m) to about 6 % average reduction. figure 7 depicts the calculated reduction versus the mast separation. 3) case– i.3 (modified design – variable electrode depth) results the results are graphed in figure 8. the jacket stress increases with electrode depth counterintuitively with more than 20 % rise obtained at increased depth compared with an electrode at a depth equal to the critical length. the behaviour is reversed after reaching a maximum value. no change to the locations of recorded maximum stress is observed. the graph indicates that a shorter electrode is more effective than a deeper one for the same lm separation. while deeper electrodes are more useful in power frequency earthing design, it adds more inductance to the high frequency circuit impeding the lightning discharge. 4) case– i.4 (modified design – variable electrode location) results the results are shown in figure 9. the electrode separation from lm is critical with a sharp increase figure 9. peak jacket stress voltage and location variation with electrode depth 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 48 50 52 54 56 58 60 0 5 10 15 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) electrode spacing from lm (m) peak jacket stress (kv) max. stress chainage (m) figure 7. peak jacket stress voltage reduction with/without electrode vs. lm separation (negative reduction % indicates stress increment with electrode) figure 8. peak jacket stress voltage and location variation with electrode depth -5 0 5 10 15 20 25 0 10 20 30 40 50 60 70 80 ja ck et s tr es s vo lta ge re du ct io n (% ) mast separation (m) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 10 20 30 40 50 60 70 0 5 10 15 20 25 30 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) electrode depth (m) peak jacket stree (kv) max. stress chainage (m) m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 196 in jacket stress voltages (18 %) with ~1 m separation. the jacket stress is almost constant for any electrode separation of more than 1 m. no change to the locations of recorded maximum stress is observed. these results emphasize the importance of a close placement of electrode and lm for mitigating underground jacket stress voltages. 5) case– ii.1 results the attainable peak jacket stress voltage with variable separation distance from the lightning mast is shown in figure 10. like case – i.1, the location of the maximum stress varies with mast separation and shows a tendency to move outside the substation grid with greater mast separation to the cable termination point. the cable stress voltage suffers a sharp decline beyond 10 m (i.e., twice the calculated effective distance). this indicates that soil resistivity affects the effective distance with a similar pattern compared to the base case. smoother maximum stress voltage chainage variation is noticed. while the maximum cable stress shows an inverse pattern with the mast separation distance, the chainage of the maximum stress is much affected by the mast location rather than the separation. 6) case– ii.2 (modified design – addition of vertical rod next to lm) results it is evident that the addition of an electrode reduces the attainable cable jacket stresses, as shown in figure 11 with a pattern similar to case-i.2. smoother maximum stress voltage chainage variation is noticed compared with the 100 ω.m case. reduction of the attainable stress voltages nears 25 % at lm separations about the effective zone radius as shown in figure 12. with the non-linear pattern, the reduction is negligible at about 50 m (~10 times the effective zone radius) with masts far away from the cable sheath earthing point. the reduction again appears with a single peak value approaching 19 % with the mast at the corner location. while most of the hazardous underground cable jacket stresses occur with short mast separations (< twice the effective zone radius), the use of electrodes at lightning masts results in higher reduction at these separations and is effective to control the attainable stresses. notwithstanding that the soil resistivity is five times that used in case-i.1 and i.2 (100 ω.m) and hence the power frequency resistance, the attainable stress voltages are not elevated by the same ratio, as shown in figure 13. the voltage rise is less than 500 % and peaks at a separation slightly greater than the effective zone radius. this indicates the nonlinear lightning response behaviour of the earthing grid due to the pronounced induction effects of the high frequency component limiting the attainable voltages/stress. the maximum stress is about 82 % of the algebraic proportion, or in other words, a minimum of about 18 % reduction is obtained with figure 10. peak jacket stress voltage and location variation vs. lm separation 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 350 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) figure 11. peak jacket stress voltage and location variation vs. lm separation 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 350 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 197 normalised 500 ω.m soil. at greater spacings, the reduction is about half of the estimated algebraic proportion value based on normalised soil resistivity. this pattern is also in line with the self-limiting characteristics of lightning surge propagation within earthing grids and the associated reduction in underground cable jacket stress. 7) case– iii.1 results the attainable jacket stress voltage with variable separation distance from the lightning mast is shown in figure 14. the majority of steep gradient appears near the lm (~effective zone radius) and the rest of the separations return a very similar value to the 24 ka injection case. the jacket stress “saturates” a few metres away from the injection point regardless of the high stroke current conforming to the effective zone concept due to the dominant inductive component with the high frequency lightning discharge. similar to case-i and case-ii, the location of maximum stress varies with mast separation, with a tendency to move outside the substation the greater the mast separation to the cable termination point. the chainage of the maximum stress is much affected by mast location rather than its separation. the self-limiting behaviour is very useful in estimating the cable stress voltage with increased stroke currents where the criticality of mast placement is not affected by the high stroke current compared to separation. figure 12. peak jacket stress voltage reduction with/without electrode vs. lm separation -5 0 5 10 15 20 25 30 0 10 20 30 40 50 60 70 80 ja ck et s tr es s vo lta ge re du ct io n (% ) mast separation (m) figure 13. peak jacket stress voltage increment with 500 ω.m soil vs. lm separat ion figure 14. peak jacket stress voltage and location variation vs. lm separation 0 50 100 150 200 250 300 350 400 450 0 10 20 30 40 50 60 70 80 ja ck et s tr es s vo lta ge in cr em en t (% ) mast separation (m) 0 10 20 30 40 50 60 70 80 0 100 200 300 400 500 600 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 198 8) case–iii.2 (modified design – addition of vertical rod next to lm) results the addition of a vertical electrode improves the attainable jacket stress pattern similar to the one observed in previous cases, as graphed in figure 15 and figure 16. as with other corresponding cases, with most of the hazardous jacket stresses taking place with short mast separations, the use of an electrode at lightning masts is effective in mitigating underground cable jacket stresses at these separations. a steep gradient of jacket stress voltage with mast separation is observed with the selflimiting behaviour contributing to the improved attainable voltages at an underground cable jacket with electrodes installed at lm. no change to the locations of recorded maximum stress is observed with the electrode compared to the case without the electrode in figure 14. reduction of the attainable stress voltages near 19 % at lm separations about the effective zone radius, as shown in figure 16. with the non-linear pattern, the reduction declines sharply at about twice the effective zone radius before dipping briefly and then sustaining a quasisteady pattern with masts far away from the cable sheath earthing point. although the injection is five times the median current (24 ka), the attainable stress voltages are almost identical to case-i, excluding the placement of lm near the cable termination point (~effective zone radius), as shown in figure 17. some locations (20 ~ 60 m separation) provide a reduction of the attainable stress compared with the 24 ka injections. this pattern demonstrates another non-linear earthing grid lightning response behaviour limiting the attainable underground cable jacket voltages/stress. the maximum stress is about 62 % of the algebraic proportion, or in other words, a minimum of about 38 % reduction is obtained with a normalised 120 ka stroke. a 20 % less obtainable jacket stress compared to the 24 ka case is encountered around 1 x effective zone radius before settling at a fractional increase (~10 % and less) at longer spacings. b. significant impact of lm separation the lightning response of earthing grids is a complex phenomenon with soil and conductors’ interactions [1]. the placement of lightning masts within the substation affects the resultant voltage stresses that appear on underground cables leaving the substation. the provision of electrodes as close as possible to the lm helps reduce the attainable voltage at the cable jacket. the non-linear behaviour of potential distributions with lightning discharge current is evident with reduced jacket stress despite higher injection currents. this is ascribed to the significant inductive effect with high frequency components of lightning discharge and the associated effective length phenomenon. figure 15. peak jacket stress voltage and location variation vs. lm separation 0 10 20 30 40 50 60 70 80 0 100 200 300 400 500 0 20 40 60 80 d is ta nc e a lo ng c ab le ( m ) ja ck et s tr es s vo lta ge (k v) mast separation (m) peak jacket stress (kv) max. stress chainage (m) figure 16. peak jacket stress voltage reduction with/without electrode vs. lm separation -5 0 5 10 15 20 25 0 10 20 30 40 50 60 70 80 ja ck et s tr es s vo lta ge re du ct io n (% ) mast separation (m) m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 199 since the effective length is much shorter than the installed earthing grid, soil resistivity is the single most important parameter in determining the lightning response of earthing grid. along with separation distance, the severity of the jacket stress on underground cables terminated at the grid can be estimated. cable jacket stresses exceeding the respective bil are likely to take place with almost 50 % of strokes intercepted by lms exceeding the median lightning current distribution. the most critical zone is the cable termination near the sealing end, where a lightning mast placement is discouraged near a cable termination. the study finding suggests twice the effective zone radius as a buffer separation. the provision of non-metallic ducts/conduits made of pvc/hdpe strengthens the jacket insulation. for underground power cable routing within substations, especially in the vicinity of lms, it should be considered as a good design practice by typically adding about 60 kv or more to jacket dielectric strength depending on conduit construction and wall thickness. the study did not consider soil ionization; however, it is not expected to largely impact the results as the conductor diameter has a minimal effect on potential distributions. iv. conclusion the introduction of lightning masts/air terminations within substation earthing grids works as a current injection point. the location of the masts affects the resultant underground cable jacket stress voltages with considerable impact taking place when the cable sheath (or route) is terminated near the lightning mast. the jacket stress is affected by soil resistivity and mast separation. the greater the separation of the lightning masts to the cable termination point or cable route, the lower the jacket stress voltages. where this is unfeasible, the study finding suggests twice the effective zone radius should be used as a buffer separation between the lm and cable (route/termination). the provision of relatively short (~effective zone radius) electrodes as close as possible to the lm effectively helps reduce the attainable stress voltages. non-metallic ducts/conduits strengthen the jacket insulation (typically adding 60 kv or more to jacket dielectric strength) and should be considered as a good practice for underground cables within substations, especially in the vicinity of lms. acknowledgements the author would like to express grateful gratitude to ghd pty. ltd for providing engineering software used in this study. declarations author contribution m. nazih is the main contributor of this paper. author read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] j. he, r. zeng, b. zhang, methodology and technology for power system grounding. john wiley & sons, 2013. [2] ieee guide for direct lightning stroke shielding of substations sponsored by the substations committee ieee power and energy society, in ieee std 998-2012 (revision of ieee std 9981996). [3] t. v. gomes, m. a. o. schroeder, r. alipio, a. c. s. de lima, & a. piantini, “investigation of overvoltages in hv underground sections caused by direct strokes considering the frequencydependent characteristics of grounding,” ieee transactions on electromagnetic compatibility, 60(6), 2002–2010, 2018. [4] s. naranjo-villamil, c. guiffaut, j. gazave, & a. reineix, “on the calculation of electrical surges in underground cables due to a direct lightning strike,” joint ieee international symposium on electromagnetic compatibility signal and power integrity, and emc europe, emc/si/pi/emc europe 2021, 682–687, 2021. figure 17. peak jacket stress voltage increment with 120/24 ka vs. lm separation (negative increment % indicates stress reduction with 120 ka lightning) -100 0 100 200 300 400 0 10 20 30 40 50 60 70 80j ac ke t st re ss v ol ta ge in cr em en t (% ) mast separation (m) https://mev.lipi.go.id/ https://doi.org/10.1002/9781118255001 https://doi.org/10.1002/9781118255001 https://doi.org/10.1109/ieeestd.2013.6514042 https://doi.org/10.1109/ieeestd.2013.6514042 https://doi.org/10.1109/ieeestd.2013.6514042 https://doi.org/10.1109/ieeestd.2013.6514042 https://doi.org/10.1109/temc.2018.2798291 https://doi.org/10.1109/temc.2018.2798291 https://doi.org/10.1109/temc.2018.2798291 https://doi.org/10.1109/temc.2018.2798291 https://doi.org/10.1109/temc.2018.2798291 https://doi.org/10.1109/emc/si/pi/emceurope52599.2021.9559365 https://doi.org/10.1109/emc/si/pi/emceurope52599.2021.9559365 https://doi.org/10.1109/emc/si/pi/emceurope52599.2021.9559365 https://doi.org/10.1109/emc/si/pi/emceurope52599.2021.9559365 https://doi.org/10.1109/emc/si/pi/emceurope52599.2021.9559365 m. nazih / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 189-200 200 [5] s. n. m. arshad, a. z. abdullah, n. s. tajudin, c. l wooi, n. h. halim, & n. hussin, “simulation on lightning effects to 132 kv underground cable by using alternative transients program / electromagnetic transients program (atp/emtp),” 2018 ieee 7th international conference on power and energy (pecon), pp. 209-214, 2018. [6] d. cao, x. liu, and x. deng, “the suitability analyses of sheath voltage limiters for hv power cable transmission lines,” 2019 2nd international conference on electrical materials and power equipment (icempe), pp. 404-408, 2019. [7] h. tanaka, y. baba, c. f. barbosa, t. tsuboi, & s. okabe, “protective effect of shield wires against direct lightning flashes to buried cables,” ieee transactions on power delivery, 33(4), 1628–1635, 2018. [8] t. kangro, j. kilter, & j. de silva, “comparative analysis of hvac cable metallic sheath modelling approaches for network studies,” proceedings of international conference on harmonics and quality of power, ichqp, 2018-may, 1-6, 2018. [9] wu, y., liu, q., yang, j. y., & liu, x, “calculation of lightning induced voltage of buried cable metal sheath,” 13th international symposium on antennas, propagation and em theory, isape 2021 – proceedings, 2021. [10] k. aniserowicz, & r. markowska, “analytical and numerical calculations of overvoltages in underground cable of intrusion detection system directly hit by lightning,” 34th international conference on lightning protection, iclp 2018, 2018. [11] chen, s., zhang, y., zhou, m., yan, x., lyu, w., & zheng, d, “transient response of surge protective devices during the potentials transferred between independent grounding grids,” ieee transactions on power delivery, 35(2), 630-638, 2020. [12] jiao, x., zhang, q., xing, h., & zhou, j., “coupling characteristics of lightning impulsive current on the underground coaxial cables,” iop conference series: earth and environmental science, 440(3), 2020. [13] m. güneri, & b. alboyaci, “analysis of ground return impedance calculation methods for modeling of underground cables for lightning studies,” turkish journal of electrical engineering and computer sciences, 26(1), 530–541, 2018. [14] w. f. a. shehab, s. a. ali, & m. i. alsharari, “lightning protection for power transformers of aqaba thermal power station,” archives of electrical engineering, 69(3), 645–660, 2020. [15] liu, x., zhang, m., wang, t., & ge, y., “fast evaluation of lightning-induced voltages of overhead line and buried cable considering the lossy ground,” iet science, measurement and technology, 13(1), 67–73, 2019. [16] s. sekioka, “simulation of lightning overvoltages in substation for lightning strike to wind turbine,” 2021 35th international conference on lightning protection, iclp 2021 and 16th international symposium on lightning protection, sipda 2021, 2021. [17] m. a. taha, li, l., & wang, p., “estimation performance of the lightning protection system in an urban 110 kv grounding grid substation,” results in engineering, 6, 2020. [18] n. a. sabiha, m. alsharef, m. k. metwaly, e. e. elattar, i. b. m. taha, & a. m. abd-elhady, ”sustaining electrification service from photovoltaic power plants during backflow lightning overvoltages,” electric power systems research, 186, 2020. [19] s. aref, & a. s. anaraki, “an investigation of the factors affecting the transition of lightning surges through underground cables and sub-transmission substations: a case study,” arxiv: physics and society, 2019. [20] r. alipio, xue, h., & a. ametani, “an accurate analysis of lightning overvoltages in mixed overhead-cable lines,” electric power systems research, 194, 2021. [21] liu, q., chang, m., & wang, l., “study on protection measures of lightning electromagnetic pulse in automatic weather station,” journal of physics: conference series, 2254(1), 2022. [22] m. goertz, s. wenig, c. hirsching, m. kahl, m. suriyah, & t. leibfried, “analysis of extruded hvdc cable systems exposed to lightning strokes,” ieee transactions on power delivery, 33(6), 3009–3018, 2018. [23] o. lennerhag, j. lundquist, c. engelbrecht, t. karmokar, & m. h. j. bollen, “an improved statistical method for calculating lightning overvoltages in hvdc overhead line/cable systems,” energies, 12(16), 2019. [24] a. eriksson, “induced effects on cables laid in the vicinity of substation lightning masts,” master thesis, department of electrical engineering, chalmers university of technology, gothenburg, 2020. [online]. [25] inclair knight merz, “incident review – otahuhu substation loss of supply 12th june 2006”, 23 june 2006. [26] primtech 3d, “lightning protection calculation,” [online] [accessed: 18-april-2022]. [27] ieee guide for bonding shields and sheaths of single-conductor power cables rated 5 kv through 500 kv sponsored by the insulated conductors committee ieee power and energy society, in ieee std 575-2014 (revision of ieee std 575-1988), 2014. [28] s. sekioka, h. otoguro, & t. funabashi, “a study on overvoltages in windfarm caused by direct lightning stroke,” ieee transactions on power delivery, 34(2), 671–679, 2019. [29] a. r. hileman, insulation coordination for power systems. 1st ed., crc press, 1999. [30] cdegs knowledge base faq 329, “effects of soil ionization,” 2004. [online] [accessed: 20-april-2022]. https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/pecon.2018.8684133 https://doi.org/10.1109/icempe.2019.8727314 https://doi.org/10.1109/icempe.2019.8727314 https://doi.org/10.1109/icempe.2019.8727314 https://doi.org/10.1109/icempe.2019.8727314 https://doi.org/10.1109/tpwrd.2017.2746100 https://doi.org/10.1109/tpwrd.2017.2746100 https://doi.org/10.1109/tpwrd.2017.2746100 https://doi.org/10.1109/tpwrd.2017.2746100 https://doi.org/10.1109/ichqp.2018.8378924 https://doi.org/10.1109/ichqp.2018.8378924 https://doi.org/10.1109/ichqp.2018.8378924 https://doi.org/10.1109/ichqp.2018.8378924 https://doi.org/10.1109/isape54070.2021.9753008 https://doi.org/10.1109/isape54070.2021.9753008 https://doi.org/10.1109/isape54070.2021.9753008 https://doi.org/10.1109/isape54070.2021.9753008 https://doi.org/10.1109/iclp.2018.8503285 https://doi.org/10.1109/iclp.2018.8503285 https://doi.org/10.1109/iclp.2018.8503285 https://doi.org/10.1109/iclp.2018.8503285 https://doi.org/10.1109/tpwrd.2019.2918713 https://doi.org/10.1109/tpwrd.2019.2918713 https://doi.org/10.1109/tpwrd.2019.2918713 https://doi.org/10.1109/tpwrd.2019.2918713 https://doi.org/10.1088/1755-1315/440/3/032024 https://doi.org/10.1088/1755-1315/440/3/032024 https://doi.org/10.1088/1755-1315/440/3/032024 https://doi.org/10.1088/1755-1315/440/3/032024 https://doi.org/10.3906/elk-1706-32 https://doi.org/10.3906/elk-1706-32 https://doi.org/10.3906/elk-1706-32 https://doi.org/10.3906/elk-1706-32 https://doi.org/10.24425/aee.2020.133923 https://doi.org/10.24425/aee.2020.133923 https://doi.org/10.24425/aee.2020.133923 https://doi.org/10.24425/aee.2020.133923 https://doi.org/10.1049/iet-smt.2018.5078 https://doi.org/10.1049/iet-smt.2018.5078 https://doi.org/10.1049/iet-smt.2018.5078 https://doi.org/10.1049/iet-smt.2018.5078 https://doi.org/10.1109/iclpandsipda54065.2021.9627343 https://doi.org/10.1109/iclpandsipda54065.2021.9627343 https://doi.org/10.1109/iclpandsipda54065.2021.9627343 https://doi.org/10.1109/iclpandsipda54065.2021.9627343 https://doi.org/10.1109/iclpandsipda54065.2021.9627343 https://doi.org/10.1016/j.rineng.2020.100140 https://doi.org/10.1016/j.rineng.2020.100140 https://doi.org/10.1016/j.rineng.2020.100140 https://doi.org/10.1016/j.epsr.2020.106386 https://doi.org/10.1016/j.epsr.2020.106386 https://doi.org/10.1016/j.epsr.2020.106386 https://doi.org/10.1016/j.epsr.2020.106386 https://doi.org/10.48550/arxiv.2001.10099 https://doi.org/10.48550/arxiv.2001.10099 https://doi.org/10.48550/arxiv.2001.10099 https://doi.org/10.48550/arxiv.2001.10099 https://doi.org/10.1016/j.epsr.2021.107052 https://doi.org/10.1016/j.epsr.2021.107052 https://doi.org/10.1016/j.epsr.2021.107052 https://doi.org/10.1088/1742-6596/2254/1/012033 https://doi.org/10.1088/1742-6596/2254/1/012033 https://doi.org/10.1088/1742-6596/2254/1/012033 https://doi.org/10.1109/tpwrd.2018.2858569 https://doi.org/10.1109/tpwrd.2018.2858569 https://doi.org/10.1109/tpwrd.2018.2858569 https://doi.org/10.1109/tpwrd.2018.2858569 https://doi.org/10.3390/en12163121 https://doi.org/10.3390/en12163121 https://doi.org/10.3390/en12163121 https://doi.org/10.3390/en12163121 https://odr.chalmers.se/bitstream/20.500.12380/300790/1/masters_thesis_antoneriksson.pdf https://odr.chalmers.se/bitstream/20.500.12380/300790/1/masters_thesis_antoneriksson.pdf https://odr.chalmers.se/bitstream/20.500.12380/300790/1/masters_thesis_antoneriksson.pdf https://odr.chalmers.se/bitstream/20.500.12380/300790/1/masters_thesis_antoneriksson.pdf http://img.scoop.co.nz/media/pdfs/0606/skmreport.pdf http://img.scoop.co.nz/media/pdfs/0606/skmreport.pdf https://www.primtech.com/en/product/lightning-protection https://www.primtech.com/en/product/lightning-protection https://doi.org/10.1109/ieeestd.2014.6905681 https://doi.org/10.1109/ieeestd.2014.6905681 https://doi.org/10.1109/ieeestd.2014.6905681 https://doi.org/10.1109/ieeestd.2014.6905681 https://doi.org/10.1109/ieeestd.2014.6905681 https://doi.org/10.1109/tpwrd.2018.2883910 https://doi.org/10.1109/tpwrd.2018.2883910 https://doi.org/10.1109/tpwrd.2018.2883910 https://doi.org/10.1201/9781420052015 https://doi.org/10.1201/9781420052015 https://www.sestech.com/en/support/faqarticle/329 https://www.sestech.com/en/support/faqarticle/329 introduction ii. materials and methods a. lightning discharge and modelling b. high voltage substation lightning protection cable jacket insulation d. earthning grid performance with lightning discharge e. methodology 1) case–i.1 2) case–i.2 3) case–i.3 4) case–i.4 5) case–ii.1 6) case–ii.2 7) case–iii.1 8) case–iii.2 iii. results and discussions a. results 1) case–i.1 results 2) case–i.2 (modified design – addition of vertical rod next to lm) results case–i.3 (modified design – variable electrode depth) results 4) case–i.4 (modified design – variable electrode location) results 5) case–ii.1 results 6) case–ii.2 (modified design – addition of vertical rod next to lm) results case–iii.1 results 8) case–iii.2 (modified design – addition of vertical rod next to lm) results b. significant impact of lm separation iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. selected applications: including all implementations or implications related to mechatronics, electrical power, or vehicular technology. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by research centre for electrical power and mechatronics indonesian institute of sciences (rcepm-lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: https://mev.lipi.go.id all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev is sinta 1 accredited by by ministry of research and technology, republic indonesia via national journal accreditation (arjuna) accreditation platform. https://sinta.ristekbrin.go.id/jo urnals/detail?id=814 postal address mev journal secretariat: research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi) komp lipi jl. sangkuriang, building 20, 2nd floor, r209 bandung, west java, 40135 indonesia tel: +62-022-2503055 (ext. 215) tel: +62-022-2504770 (ext. 203) fax: +62-22-2504773 business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: mev@mail.lipi.go.id https://mev.lipi.go.id/ https://sinta.ristekbrin.go.id/journals/detail?id=814 https://sinta.ristekbrin.go.id/journals/detail?id=814 mailto:mev@mail.lipi.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: https://mev.lipi.go.id/mev/login need a username/password? go to registration at: https://mev.lipi.go.id/mev/user/r egister registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate® and also using grammarly® plagiarism checker. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), microsoft academic search, science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. cc license mev journal by rcepm-lipi allows reuse and remixing of its content under a cc by-nc-sa creative commons attributionnoncommercial-sharealike 4.0 international license. permissions beyond the scope of this license may be available at https://mev.lipi.go.id. if you are a nonprofit or charitable organization, your use of an nc-licensed work could still run afoul of the nc restriction, and if you are a forprofit entity, your use of an nclicensed work does not necessarily mean you have violated the term. https://mev.lipi.go.id/mev/login https://mev.lipi.go.id/mev/user/register https://mev.lipi.go.id/mev/user/register http://www.telimek.lipi.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 editor-in-chief dr. haznan abimanyu, dip.ing. research centre for electrical power and mechatronics indonesian institute of sciences bandung 40135, indonesia associate editor (main handling editor) yanuandri putrasari, ph.d. research centre for electrical power and mechatronics – lipi bandung, indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, malaysia prof. dr. estiko rijanto research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia prof. tapan kumar saha electrical engineering, the university of queensland, australia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, universitas sebelas maret surakarta, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology, japan prof. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, indonesia prof. dr. bambang riyanto trilaksono school of electrical engineering and informatics, bandung institute of technology, indonesia prof. keum shik hong dept. of mechanical engineering, pusan national university, korea, republic of prof. taufik director of electric power institute, california polytechnique, united states prof. dr. adi soeprijanto dept. of electrical engineering, institut teknologi sepuluh nopember (its), indonesia prof. pekik argo dahono school of electrical engineering and informatics, bandung institute of technology, indonesia assoc. prof. hazim moria department of mechanical engineering, yanbu industrial college, saudi arabia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, australia assoc. prof. roonak daghigh university of kurdistandisabled, sanandaj, iran, islamic republic of asst. prof. mohammad h. yazdi mechanical eng. dept., islamic azad university, iran, islamic republic of dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales, australia dr. ahmad fudholi solar energy research institute, universiti kebangsaan malaysia, malaysia dr. ali h.a. al-waeli solar energy research institute, universiti kebangsaan malaysia, malaysia george anwar, ph.d. university of california, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia, indonesia riza muhida, ph.d. stkip surya, indonesia dr.eng. budi prawara research centre for electrical power and mechatronics indonesian institute of sciences (lipi), indonesia advisory editor prof. ocktaeck lim school of mechanical engineering, university of ulsan, korea, republic of prof. dr. endra joelianto engineering physics, bandung institute of technology, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 © 2021 rcepm-lipi. all rights reserved. this journal and the individual contributions contained in it are protected under copyright by research centre for electrical power and mechatronics, indonesian institute of sciences (rcepm lipi). and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 foreword from editor-in-chief it is my pleasure to welcome you to the 2nd issue of volume 12 in the year 2021 of the journal of mechatronics, electrical power, and vehicular technology (mev), a peer-reviewed and broad-scope international journal. this journal aims to bridge the gap in mechatronics, electrical power, and vehicular technology and is designed to advance scientific knowledge and foster innovative engineering solutions. it addresses both academics and practicing professionals, which has become an increasingly recognized international journal in the past years and indexed by many internationally recognized indexers. this issue consists of eight papers written by authors from different countries, such as turkey, australia, ghana, united kingdom, and indonesia. the articles span a wide range of topics, from artificial intelligence to the analysis of the domestic component level. therefore, they may be classified as follows. the first paper presents the control of the formation of differential mobile robots based on the leader-follower approach. the second paper discusses how to determine and allocate dimensional and geometric tolerances to design a 10 kw, 500 rpm radial flux permanent magnet generator prototype components. the third paper proposes a simple hardware-in-the-loop (hil) simulation setup designed as instructional media for design and testing a simple control system. the fourth paper investigates the dcl of a developed multipurpose autonomous robot in indonesia called rom20. the fifth paper identifies loss distribution according to core materials and compares them in power density and cost. the sixth paper presents an alternative design and implementation of a low-cost solid-state oltc. it employs a microcontroller-based control strategy, ensuring the flexibility and controllability required in programming the control algorithms. the seventh paper investigates pipe buckling strength under pure bending and external pressure by nonlinear finite element analysis. the last paper in this issue aims to design and construct an autonomous mobile robot with a vision-based system for outdoor navigation. since the first volume, our journal provides discretion in financial terms by waiving the article processing charge. finally, as the editor-in-chief of this promising journal, i would like to acknowledge our immense gratitude to our international editorial board members, reviewers, and authors for their excellent works and remarkable contributions. each issue of this journal offers valuable reports and articles to the practitioners and research experts. we encourage academic and research professionals to submit manuscripts on practical and scientific key issues in mechatronics, electrical power, and vehicular technology of all disciplines. we are looking forward to receiving extraordinary manuscripts and promoting cutting-edge technology development. we hope this publication will contribute to the enhancement of science and technology. bandung, december 2021 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 ii list of contents control of mobile robot formations using a-star algorithm and artificial potential fields nelson luis manuel, nihat i̇nanç, mustafa yasin erten ....................................................................... 57-67 geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design muhammad fathul hikmawan, agung wibowo, muhammad kasim ............................................. 68-80 hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing muhammad zakiyullah romdlony, fakih irsyadi .................................................................................. 81-86 domestic component level analysis for multipurpose autonomous robot vita susanti, henny sudibyo, ridwan arief subekti, ghalya pikra, rakhmad indra pramana, andri joko purwanto, merry indahsari devi, agus fanar syukri, roni permana saputra ............................................................................................................................................................... 87-94 effect of different core materials in very low voltage induction motors for electric vehicle fransisco danang wijaya, iftitah imawati, muhammad yasirroni, adha imam cahyadi ........ 95-103 an alternative design and implementation of a solid state on-load tap changer benjamin kommey, elvis tamakloe, gideon adom-bamfi, daniel opoku................................. 104-109 study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis hartono yudo, wilma amiruddin, ari wibawa budi santosa, ocid mursid, tri admono ..... 110-116 vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications leonard rusli, brilly nurhalim, rusman rusyadi .............................................................................. 117-125 complete articles can be found at https://mev.lipi.go.id https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 iii journal of mechatronics, electrical power, and vehicular technology volume 12, issue 2, 2021 abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. nelson luis manuel, nihat i̇nanç, mustafa yasin erten (department of electrical & electronics engineering, kırıkkale university, turkey) control of mobile robot formations using a-star algorithm and artificial potential fields journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 57-67, 18 ill, 0 tab, 19 ref. formations or groups of robots become essential in cases where a single robot is insufficient to satisfy a given task. with an increasingly automated world, studies on various topics related to robotics have been carried out in both the industrial and academic arenas. in this paper, the control of the formation of differential mobile robots based on the leader-follower approach is presented. the leader's movement is based on the least cost path obtained by the a-star algorithm, thus ensuring a safe and shortest possible route for the leader. follower robots track the leader's position in real time. based on this information and the desired distance and angle values, the leader robot is followed. to ensure that the followers do not collide with each other and with the obstacles in the environment, a controller based on artificial potential fields is designed. stability analysis using lyapunov theory is performed on the linearized model of the system. to verify the implemented technique, a simulator was designed using the matlab programming language. seven experiments are conducted under different conditions to show the performance of the approach. the distance and orientation errors are less than 0.1 meters and 0.1 radians, respectively. overall, mobile robots are able to reach the goal position and maintaining the desired formation in finite time. (author) keywords: nonholonomic wmr; leader-follower approach; formation control; a-star algorithm; artificial potential fields. muhammad fathul hikmawan a, b, agung wibowo b, muhammad kasim a, c (a research centre for electrical power and mechatronics, indonesian institute of sciences (lipi), indonesia; b faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia; c school of electrical engineering and telecommunications, university of new south wales, australia) geometrical and dimensional tolerance analysis for the radial flux type of permanent magnet generator design journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 68-80, 17 ill, 9 tab, 24 ref. mechanical tolerance is something that should be carefully taken into consideration and cannot be avoided in a product for manufacturing and assembly needs, especially in the design stage, to avoid excessive dimensional and geometric deviations of the components made. this paper discusses how to determine and allocate dimensional and geometric tolerances in the design of a 10 kw, 500 rpm radial flux permanent magnet generator prototype components. the electrical and mechanical design results in the form of the detailed nominal dimensions of the generator components, and the allowable air gap range are used as input parameters for tolerance analysis. the values of tolerance allocation and re-allocation process are carried out by considering the capability of the production machine and the ease level of the manufacturing process. the tolerance stack-up analysis method based on the worst case (wc) scenario is used to determine the cumulative effect on the air gap distance due to the allocated tolerance and to ensure that the cumulative effect is acceptable so as to guarantee the generator's functionality. the calculations and simulations results show that with an air gap of 1 ± 0.2 mm, the maximum air gap value obtained is 1.1785 mm, and the minimum is 0.8 mm. the smallest tolerance value allocation is 1 µm on the shaft precisely on the fsbs/srbs feature and the rotor on the rpms feature. in addition, the manufacturing process required to achieve the smallest tolerance allocation value is grinding, lapping, and polishing processes. (author) keywords: permanent magnet generator; mechanical design; tolerance analysis. muhammad zakiyullah romdlony a, fakih irsyadi b (a school of electrical engineering, telkom university, indonesia; b department of electrical engineering and informatics, vocational college, universitas gadjah mada, indonesia) hardware-in-the-loop simulation of dc motor as an instructional media for control system design and testing journal of mechatronics, electrical power, and vehicular journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 iv technology, 2021, vol. 12, no. 2, p. 81-86, 5 ill, 4 tab, 18 ref. instructional media in control systems typically requires a real plant as an element to be controlled. however, this real plant, which is costly to be implemented, can be replaced by a virtual plant implemented in a computer and modelled in such a way that it resembles the behavior of a real plant. this kind of set-up is widely termed as hardware-in-the-loop (hil) simulation. hil simulation is an alternative way to reduce the development cost. a virtual plant is easy to adjust to represent various plants or processes that are widely used in industry. this paper proposes a simple hil simulation set-up designed as instructional media for design and testing a simple control system. the experimental result on dc motor control shows that hil simulation dynamical response is similar to the real hardware response with a small average error on measured transient response, represented in 0.5 seconds difference in settling time and 7.43 % difference in overshoot. this result shows the efficacy of our hil simulation set-up. (author) keywords: control systems; hardware-in-the-loop (hil); instructional media. vita susanti a, henny sudibyo a, ridwan arief subekti a, ghalya pikra a, rakhmad indra pramana a, andri joko purwanto a, merry indahsari devi a, agus fanar syukri b, roni permana saputra a, c (a research centre for electrical power and mechatronics – indonesian institute of sciences, indonesia; b research center for policy and management of science, technology, and innovation– indonesian institute of sciences, indonesia; robot intelligence laboratory, dyson school of design engineering, imperial college london, united kingdom) domestic component level analysis for multipurpose autonomous robot journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 87-94, 5 ill, 7 tab, 34 ref. multipurpose autonomous robot technology has been developed to assist transportation sectors or the current emergency as the covid-19 pandemic. a practical issue in the robotic industry concerns the domestic content in commodities, services, and a combination of goods and services commonly determined as domestic component level (dcl). to be considered a standardized national product, a product's dcl must surpass a certain level of local content composition. this research aims to investigate the dcl of a developed multipurpose autonomous robot in indonesia called rom20. the research was initiated by interviewing specialists in dcl calculation and robotics research to perform dcl analysis on rom20. the next step was breaking down the rom20 components into a second layer component, in which the amount of domestic component and overseas components can be derived. finally, the rom20 dcl value was calculated by dividing the cost of domestic components by the total cost of domestic and overseas components. as a digital product, the rom20 dcl calculation result showed that the manufacturing aspect is 70 %, and the development aspect is 30 %. the overall rom20 dcl value has been calculated as 52.23 %, which surpasses the national standard threshold at 40 % dcl value. therefore, rom20 can be considered a high-value standardized national product, impacting the competitiveness of local products and the fast-growing medical device industry in indonesia. (author) keywords: domestic component level; modular system; multipurpose autonomous robot; rom20. fransisco danang wijaya a, iftitah imawati b, muhammad yasirroni a, adha imam cahyadi a (a department of electrical engineering and information technology, universitas gadjah mada, indonesia; b department of electrical engineering, universitas islam indonesia, indonesia) effect of different core materials in very low voltage induction motors for electric vehicle journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 95-103, 12 ill, 6 tab, 20 ref. the use of squirrel cage induction motor for electric vehicle (ev) has been increasingly popular than permanent magnet and brushless motors due to their independence on rare materials. however, its performance is significantly affected by the core materials. in this research, induction motors performance with various core materials (m19_24g, arnon7, and nickel steel carpenter) are studied in very low voltage. three phases, 50 hz, 5 hp, 48 v induction motor were used as the propulsion force testbed applied for a golf cart ev. the aims are to identify loss distribution according to core materials and compare power density and cost. the design process firstly determines the motor specifications, then calculates the dimensions, windings, stator, and rotor slots using matlab. the parameters obtained are used as inputs to ansys maxwell to calculate induction motor performance. finally, the design simulations are carried out on rmxprt and 2d transient software to determine the loss characteristics of core materials. it is found that the stator winding dominates the loss distribution. winding losses have accounted for 52-55 % of the total loss, followed by rotor winding losses around 25-27 % and losses in the core around 1-7 %. based on the three materials tested, nickel steel carpenter and m19_24g attain the highest efficiency with 83.27 % and 83.10 %, respectively, while m19_24g and arnon7 possess the highest power density with 0.37 kw/kg and 0.38 kw/kg whereas, in term of production cost, the arnon7 is the lowest. (author) keywords: squirrel cage induction motor; power losses; power density; power efficiency; loss distribution. benjamin kommey a, elvis tamakloe b, gideon adom-bamfi b, daniel opoku b (a kwame nkrumah university of science and technology, pmb knustcoe, ghana; b kwame nkrumah university of science and technology, pmb knustee, ghana) an alternative design and implementation of a solid state on-load tap changer journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 104-109, 7 ill, 1 tab, 25 ref. power quality and reliability are of great importance in the modern world, whether it be the power generated by the power utilities or the power consumed by the customer respectively. they need these supplies to be at its optimum value so that the cost is effective, and the safety of devices assured otherwise problems such as overvoltage, undervoltage, and voltage sags caused by disturbances in the power supply could be disastrous. on-load tap changers (oltc) have therefore been used since the inception of electrical engineering. the main function of the oltc is to change the turns of the transformer winding so that the voltage variations are limited without interrupting the secondary current. the major idea is that the electronic switches and other smart systems provide more controllability during the tap changing process, unlike mechanical switches. this paper presents an alternative journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 v design and implementation of a low-cost solid-state oltc and employs a control strategy that is microcontrollerbased, ensuring the desired flexibility and controllability required in programming the control algorithms. it eliminates the limitations of both mechanical and hybrid oltcs (arcing, slow response time, losses) and is userfriendly (provides an effective communication medium). voltage regulation is achieved by varying the turns of the transformer winding whiles it is energized, supplying load current and with the tap selection carried out on the primary side. therefore, this approach provides a less expensive system but ensures the efficiency and reliability of voltage regulation. (author) keywords: on-load tap changer; solid-state switch; potential transformer winding; voltage regulation. hartono yudo a, wilma amiruddin a, ari wibawa budi santosa a, ocid mursid a, tri admono b (a department of naval architecture, faculty of engineering, diponegoro university, indonesia; b research centre for electrical power and mechatronics, indonesian institute of sciences, indonesia) study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 110-116, 9 ill, 0 tab, 15 ref. buckling and collapse are important failure modes for laying and operating conditions in a subsea position. the pipe will be subjected to various kinds of loads, i.e., bending moment, external pressure, and tension. nonlinear finite element analysis was used to analyze the buckling strength of the pipe under pure bending and external pressure. the buckling of elastic and elasto-plastic materials was also studied in this work. the buckling strength due to external pressure had decreased and become constant on the long pipe when the length-todiameter ratio (l/d) was increased. the non-dimensional parameter (β), which is proportionate to (d/t) (σy/e), is used to study the yielding influence on the buckling strength of pipe under combined bending and external pressure loading. the interaction curves of the buckling strength of pipe were obtained, with various the diameterto-thickness ratio (d/t) under combination loads of external pressure and bending moment. for straight pipes l/d = 2.5 to 40, d = 1000 to 4000 mm, and d/t = 50 to 200 were set. the curved pipes d/t = 200, l/d =2.5 to 30 have been investigated by changing the radius of curvature-todiameter ratio (r/d) from 50 to ∞, for each one. with decreasing r/d, the buckling strength under external pressure decreases slightly. this is in contrast to the bending of a curved pipe. when the value of r/d was decreased, the flexibility of the pipe was increased. however, the buckling strength of the pipe during bending was decreased due to the oval deformation at the crosssection. (author) keywords: buckling strength; elastic buckling; elastoplastic buckling; bending moment; external pressure. leonard rusli, brilly nurhalim, rusman rusyadi (mechatronics department, swiss german university, indonesia) vision-based vanishing point detection of autonomous navigation of mobile robot for outdoor applications journal of mechatronics, electrical power, and vehicular technology, 2021, vol. 12, no. 2, p. 117-125, 21 ill, 0 tab, 16 ref. the vision-based approach to mobile robot navigation is considered superior due to its affordability. this paper aims to design and construct an autonomous mobile robot with a vision-based system for outdoor navigation. this robot receives inputs from camera and ultrasonic sensor. the camera is used to detect vanishing points and obstacles from the road. the vanishing point is used to detect the heading of the road. lines are extracted from the environment using a canny edge detector and houghline transforms from opencv to navigate the system. then, removed lines are processed to locate the vanishing point and the road angle. a low pass filter is then applied to detect a vanishing point better. the robot is tested to run in several outdoor conditions such as asphalt roads and pedestrian roads to follow the detected vanishing point. by implementing a simple blob detector from opencv and ultrasonic sensor module, the obstacle's position in front of the robot is detected. the test results show that the robot can avoid obstacles while following the heading of the road in outdoor environments. vision-based vanishing point detection is successfully applied for outdoor applications of autonomous mobile robot navigation. (author) keywords: houghline transform (houghlinep); road lines detection; simple blob detector; vanishing point determination. foreword from editor-in-chief list of contents mev mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.73-80 effect of contact pressure on the resistance contact value and temperature changes in copper busbar connection pengaruh tekanan kontak terhadap nilai tahanan kontak dan perubahan temperatur pada sambungan busbar tembaga agus risdiyanto a, b, noviadi arief rachman b, *, maulana arifin b a sekolah teknik elektro dan informatika, institut teknologi bandung jl. ganesha 10, bandung, jawa barat 40132, indonesia b pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl. sangkuriang no.21/154d, bandung 40135, indonesia received 11 oct 2012; received in revised form 19 november 2012; accepted 19 november 2012 published online 18 december 2012 abstract this paper discussed the influence of tightness or contacts pressure on copper busbar joints to determine changes in the value of the initial contact resistance and the maximum temperature at the joint due to high current load. the test sample was copper busbar 3 x 30 mm with configuration of bolted overlapping joint. increasing contact pressure at the joint was measured to find out its effect on the value of contact resistance. the applied pressure was 6 to 36 mpa. procedure of contact resistance measurement refer to the astm b539 standard using four-wire method. the sample subsequently loaded with the current of 350 a for 60 minutes and the maximum temperature at the joint was measured. the result showed that increasing contact pressure at the busbar joint will reduce the contact resistance and maximum temperature. the increase of contact pressure from 6 to 30 mpa causes decreasing contact resistance from 16 µω to 11 µω. further increasing of contact pressure more than 30 mpa did not affect the contact resistance significantly. the lowest temperatur of busbar joint of 54°c was reached at a contact pressure of 36 mpa. key words: contact pressure, contact resistance, maximum temperature, copper busbar joint. abstrak paper ini membahas pengaruh kekencangan atau tekanan kontak pada sambungan busbar tembaga untuk mengetahui perubahan nilai tahanan kontak awal dan temperatur maksimum pada sambungan akibat pembebanan arus yang tinggi. sampel uji menggunakan busbar tembaga ukuran 3 x 30 mm untuk konfigurasi sambungan tumpang tindih dengan baut tunggal. peningkatan tekanan kontak pada sambungan diukur untuk mengetahui pengaruhnya terhadap nilai tahanan kontak. besarnya tekanan kontak yang diterapkan adalah 6 sampai 36 mpa. prosedur pengukuran tahanan kontak mengacu pada standar astm b539 menggunakan metode empat kawat. selanjutnya sampel dibebani dengan arus 350 a selama 60 menit kemudian diukur temperatur maksimum pada masing-masing tekanan kontak. hasil pengujian menunjukkan bahwa nilai tahanan kontak pada sambungan busbar akan semakin kecil dengan meningkatnya tekanan kontak.. peningkatan tekanan kontak dari 6 sampai 30 mpa menurunkan nilai tekanan kontak dari 16 micro ohm sampai 11 micro ohm. peningkatan tekanan kontak pada tekanan lebih dari 30 mpa tidak menyebabkan kenaikan tahanan kontak secara signifikan. temperatur terendah sambungan busbar adalah 54°c dan dicapai pada tekanan kontak 36 mpa. kata kunci: tekanan kontak, tahanan kontak, temperatur maksimum, sambungan busbar tembaga. i. pendahuluan sistem pembangkit tenaga listrik memerlukan optimasi dalam penyaluran energi listrik mulai dari pembangkitan, transmisi, distribusi sampai ke peralatan listrik konsumen. semua peralatan yang didesain tidak hanya mampu memenuhi fungsinya, namun harus memiliki ketahanan terhadap berbagai kondisi operasi diluar normal baik dari segi kelistrikan, mekanik, faktor lingkungan, serta pertimbangan ekonomis [1]. salah satunya adalah sistem sambungan * corresponding author. tel: +62-22-2503055 e-mail: opay_23@yahoo.com http://dx.doi.org/10.14203/j.mev.2012.v3.73-80 a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 74 penghantar yang menjadi komponen paling penting peranannya dalam efisiensi penyaluran energi listrik. sambungan yang stabil dan memiliki tahanan kontak yang kecil akan mengurangi biaya pemeliharaan serta mengurangi down time keseluruhan peralatan sehingga resiko kegagalan dapat ditekan [2]. semakin besar tahanan kontak pada sambungan dan jika dialiri arus yang cukup besar, maka semakin besar pula jatuh tegangan (vd) dan rugi-rugi daya (i2r) yang terjadi. nilai rugi-rugi daya yang terjadi pada setiap sambungan ini jika dijumlahkan bisa sangat signifikan besarnya mengingat dalam suatu sistem tenaga listrik terdapat ratusan hingga ribuan sambungan. jadi dalam suatu saluran yang mengalirkan arus listrik, rugi-rugi daya saluran tidak hanya ditentukan oleh tahanan saluran saja, namun ditentukan juga oleh besarnya tahanan kontak pada setiap sambungan dan besarnya arus yang mengalir pada saluran tersebut [3]. kegagalan kontak listrik pada sambungan biasanya terjadi karena instalasi awal yang tidak baik, atau karena terjadi pengendoran pada kontak selama waktu operasi serta pengaruh kondisi lingkungan yang tidak sesuai. hal ini dapat mengakibatkan temperatur pada sambungan semakin meningkat dan kondisi ini dapat merusak peralatan lain disekitarnya bahkan dapat menimbulkan kebakaran. gambar 1 menunjukkan salah satu contoh bentuk pemanasan yang berlebih pada sambungan busbar salah satu phasa dengan circuit breaker akibat dari kinerja kontak yang buruk. selanjutnya paper ini membahas pengaruh besarnya kekencangan atau tekanan kontak pada sambungan busbar tembaga terhadap perubahan nilai tahanan kontaknya yang juga berdampak pada perubahan temperatur pada sambungan. ii. dasar teori sambungan penghantar busbar (busbar joint) merupakan pertemuan antara penghantar yang bertegangan dengan penghantar tidak bertegangan dengan maksud untuk menyalurkan arus atau energi listrik dari sumber ke peralatan listrik lainnya. adanya sambungan disebabkan karena keterbatasan panjang penghantar yang ada tidak memenuhi jarak antara sumber listrik ke beban. selain itu, sistem sambungan diperlukan karena adanya sumber yang melayani beberapa beban secara paralel. dalam pemasangannya, sambungan busbar dengan baut secara mekanik memiliki tekanan yang kuat, stabil, tahan getaran karena akan mempengaruhi nilai tahanan kontak sambungan. contoh jenis sambungan busbar tembaga dengan baut dapat ditunjukan seperti pada gambar 2, dimana cu: tembaga, b: tebal tembaga, h: lebar tembaga, dan lc: daerah pertemuan kontak. gambar 3 menunjukkan daerah pertemuan kontak antar sambungan busbar yang memiliki distribusi kerapatan arus yang tidak seragam. distribusi arus yang tidak seragam ini dapat menyebabkan daerah sambungan memiliki temperatur yang lebih tinggi dibandingkan temperatur diluar sambungan [4]. (a) (b) gambar 1. pemanasan sambungan busbar dengan circuit breaker akibat kontak yang buruk, (a) foto visual, (b) foto infra merah. gambar 2. sistem sambungan busbar dengan baut tunggal (bolted busbar joint). gambar 3. distribusi kerapatan arus pada sambungan busbar. a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 75 a. kekuatan mekanik sambungan suatu kontak listrik yang dirancang dengan baik harus memiliki kekuatan mekanik yang cukup untuk menjaga integritas mekanik dalam kondisi beban normal maupun beban lebih. kontak harus memiliki tekanan yang cukup untuk mempertahankan bidang kontak, sehingga memungkinkan bagian yang tidak terputus saat dilewati arus. semakin besar gaya tekan kontak maka tahanan kontaknya akan semakin kecil. namun tekanan ini tidak boleh melebihi batas elastis dari material lapisan kontak karena deformasi plastis dapat meningkatkan tekanan relaksasi yang akan menyebar ke seluruh bagian kontak dan dapat menyebabkan hilangnya kontak. hubungan antara nilai tahanan kontak (rc) dengan gaya tekan kontak dapat ditunjukan dengan persamaan (1) [1]: 𝑅𝑅𝑐𝑐 = 𝐶𝐶 𝐹𝐹𝑛𝑛 (1) dimana, rc : tahanan kontak (ω) c : konstanta f : gaya tekan (newton) n : eksponen nilai c dan n ditentukan berdasarkan konfigurasi jenis sambungan, tipe lubrikasi sambungan dan material pelapis sambungan. semakin besar gaya tekan kontak maka tahanan kontaknya akan semakin kecil. namun tekanan ini tidak boleh melebihi batas elastis dari material lapisan kontak karena deformasi plastis dapat meningkatkan tekanan relaksasi yang akan menyebar ke seluruh bagian kontak. jika batas elastis busbar terlampaui maka tekanan kontak pada sambungan akan menurun dan tahanan kontaknya dapat meningkat kembali. hal ini disebabkan karena perbedaan koefisien ekspansi antara busbar tembaga dengan baut stainles steel [5]. sambungan busbar dengan baut memiliki beberapa konfigurasi ukuran busbar dan jumlah baut. jumlah dan ukuran baut biasanya bervariasi dari m6 sampai m20 sesuai dengan area sambungan. torsi yang dipilih untuk masingmasing ukuran baut tergantung pada material baut dan suhu operasi maksimum yang diijinkan. tabel 1 dan tabel 2 masing-masing menunjukan ukuran dan jumlah baut yang digunakan pada beberapa jenis konfigurasi sambungan busbar dan besarnya torsi yang diijinkan berdasarkan ukuran baut sambungan menurut standar din 43673. tahanan kontak tahanan kontak (contact resistance) merupakan kriteria utama yang menentukan kehandalan kontak listrik suatu sambungan [6]. nilai tahanan kontak suatu sambungan harus sekecil mungkin karena berhubungan dengan rugi-rugi daya dan peningkatan temperatur. biasanya tahanan kontak suatu sambungan atau konektor yang mengalirkan arus listrik diukur dalam orde mikro ohm (µω). tabel 1. ukuran dan jumlah baut yang digunakan pada beberapa tipe sambungan busbar. bar width (mm) shape 1 shape 2 & 2a shape 3 bolt size hole diameter l a l a b c l a b c 12 12 6 m5 5,5 15 15 7,5 m6 6,5 20 20 10 m8 9 25 25 12,5 55 12,5 30 m10 11 30 30 15 60 15 30 m10 11 40 40 20 80 20 40 m12 13,5 50 50 25 80 20 40 m12 13,5 60 80 20 40 m12 13,5 60 60 17 26 26 m12 13,5 80 80 20 40 40 m12 13,5 100 80 20 40 50 m12 13,5 120 80 20 40 60 m12 13,5 a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 76 nilai tahanan kontak dapat meningkat terhadap fungsi waktu tergantung pada area kontak, permukaan, material, tekanan kontak serta kondisi lingkungan seperti kelembaban, kontaminan dan lain-lain. kontak listrik yang buruk terjadi jika hanya sebagian dari seluruh permukaan kontak saling bertemu, dengan kata lain permukaan lapisan kontak tidak rata karena mengalami penyempitan. dengan adanya penyempitan permukaan kontak ini maka distribusi kerapatan arus menjadi semakin besar dan daerah inilah yang menjadi sumber panas dari suatu sambungan (hot spot). penyempitan permukaan kontak tersebut dapat diilustrasikan seperti gambar 4. tahanan yang timbul di daerah penyempitan permukaan kontak sambungan disebut juga tahanan penyempitan (constriction resistance) yang nilainya tergantung pada karakteristik material permukaan seperti tingkat kekerasan (hardness) dan resistivitasnya. selanjutnya tahanan penyempitan kontak (spot) antara dua material penghantar yang sama dapat dituliskan dengan persamaan (2) [7]: 𝑅𝑅𝑐𝑐 = 𝜌𝜌 2𝑝𝑝 (2) dimana: rc : tahanan kontak (ω) ρ : resistivitas dua penghantar yang saling kontak (ωm) a : luas area kontak (m2) masalah utama dalam penggunaan kontak sambungan paduan tembaga adalah mudah bereaksi pada lingkungan atmosfer. lapisan oksida ini terbentuk karena terjadinya reaksi kimia antara unsur kimia logam dengan oksigen. lapisan oksida (oxide film) atau kontaminasi pada permukaan kontak akan meningkatkan tahanan listrik yang dapat menyebabkan kegagalan dalam aplikasi kontak [8]. lapisan oksida maupun lapisan material konduktif yang ada pada permukaan kontak sambungan tersebut selanjutnya dikenal dengan istilah thin film. sehingga tahanan total dari suatu sambungan merupakan penjumlahan dari tahanan penyempitan dan tahanan thin film, dan dapat dituliskan dengan persamaan (3) dan (4) [7]: 𝑅𝑅𝑗𝑗 = 𝑅𝑅𝑐𝑐 + 𝑅𝑅𝑓𝑓 (3) dan 𝑅𝑅𝑐𝑐 = 𝜌𝜌 2𝑝𝑝 𝑅𝑅𝑓𝑓 = 𝜎𝜎 𝜋𝜋𝑝𝑝 2 (4) dimana, rj : tahanan total sambungan (joint resistance) (ω) rc : tahanan kontak (ω) rf : tahanan lapisan film (ω) σ : tahanan per area luas lapisan film (ω/m2) b. efek pemanasan pada sambungan koefisien temperatur (α) dari suatu bahan menunjukan perubahan tahanan untuk tahanan sebesar 1 ω pada pemanasan 1 k. tahanan pada beberapa bahan penghantar (terutama pada bahan logam murni) akan bertambah dengan kenaikan temperatur sesuai dengan persamaan (5) [3]: 𝑅𝑅𝑡𝑡 = 𝑅𝑅0 [1 + 𝛼𝛼0 (𝑡𝑡 − 𝑡𝑡0 )] (5) dimana: rt : tahanan penghantar temperatur t (ω) r0 : tahanan penghantar pada temperatur awal/ambien (ω) α0 : koefisien temperatur awal (k-1) t : temperatur akhir (°c) t0 : temperatur awal/ambien (°c) tabel 2. kekuatan torsi yang diijinkan berdasarkan ukuran baut yang digunakan pada tipe sambungan. bolt size hole diameter torque (nm) indoor outdoor m5 5,5 2,5 3 m6 6,5 4,5 5,5 m8 9 10 15 m10 11 20 30 m12 13,5 40 60 (a) (b) gambar 4. (a) gambar permukaan kontak yang mengalami penyempitan (hot spot); (b) gambar penyempitan kontak. a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 77 kontak listrik yang dilewati arus yang tinggi dapat menimbulkan disipasi daya di sepanjang bagian kontak dengan penghantar. disipasi daya tergantung pada rugi-rugi daya i2r di bagian pertemuan kontak dan di sepanjang penghantar. arus yang tinggi juga dapat menyebabkan tegangan jatuh (voltage drop) pada bagian sambungan karena tahanan kontak yang besar. akibatnya akan terjadi peningkatan temperatur. temperatur maksimum yang diijinkan untuk penghantar rel busbar tembaga adalah 65°c [9]. hubungan tegangan jatuh pada sambungan dengan temperatur yang terjadi dapat dituliskan dengan persamaan (6) [7]: 𝑇𝑇𝑐𝑐 2 − 𝑇𝑇0 2 = 𝑉𝑉𝑑𝑑 2 4𝐿𝐿 (6) dimana: tc : temperatur akhir kontak sambungan (°c) t0 : temperatur awal/ambient (°c) vd : tegangan jatuh sambungan (volt) l : konstanta wiedemann-franz lorenz (2,45x10-8, v2/k2) temperatur kontak yang tinggi dapat berdampak pada proses degradasi sambungan listrik. dengan demikian, kenaikan temperatur dalam kontak listrik untuk sistem tegangan tinggi menjadi salah satu parameter utama yang dipertimbangkan penggunaannya dalam aplikasi tertentu [10]. iii. pengujian dan eksperimen pengujian dilakukan menggunakan busbar tembaga (copper busbar) dengan kapasitas arus nominalnya adalah 350 a, sehingga ukuran busbar menurut standar sni 04-0225-2000 (persyaratan umum instalasi listrik) memiliki luas penampang, tebal x lebar = 3 x 30 mm = 90 mm2, dengan luas area kontaknya adalah 30 x 30 mm. baut yang digunakan untuk mengencangkan sambungan adalah baut stainless steel dengan ukuran m10. gambar 5 menunjukkan langkahlangkah dalam pengujian tahanan kontak dan temperatur sambungan busbar. dimensi dan tipe sambungan busbar mengacu pada tabel 1 dengan menggunakan shape 1 seperti pada gambar 6. pengujian dilakukan dengan dua tahap. tahap pertama dilakukan pengujian untuk mengetahui pengaruh penambahan tekanan kontak terhadap nilai tahanan kontak. penambahan tekanan kontak dilakukan dengan menambah kekencangan baut kontak. alat yang digunakan adalah torsi meter mekanik dengan tekanan antara 6 sampai dengan 36 mpa, seperti mulai penyiapan sampel pengukuran tahanan kontak pengujian arus tinggi pengukuran tekanan kontak data pengukuran temperatur analisis selesai komparasi studi literatur gambar 5. langkah-langkah dalam pengujian tahanan kontak dan temperatur sambungan busbar. 30 11 (m10) 40 17 (m16) 300 4030 10 (a) (b) gambar 6. dimensi dan konfigurasi sampel sambungan busbar sesuai shape 1 (tabel 1). (a) tampak atas; (b) tampak samping. a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 78 ditunjukkan pada gambar 7(a). pengukuran tahanan kontak sambungan busbar dilakukan dengan metode 4 kawat seperti ditunjukkan pada gambar 7(b) diatas. arus akan mengalir ke sambungan busbar dengan menggunakan sumber arus dc (i), melalui 2 kawat penghantar yang terhubung ke ujung sambungan. besarnya arus yang dialirkan ke sambungan bervariasi antara 2 a, 4 a, dan 6 a. kemudian pada titik yang sama digunakan 2 kawat lagi yang terhubung ke voltmeter untuk mengukur besarnya tegangan jatuh (∆vd) pada masing-masing arus yang terjadi di sambungan dan biasanya dalam orde mili volt. selanjutnya untuk menentukan tahanan kontak (rc) dilakukan dengan menggunakan persamaan (7) [11]. 𝑅𝑅𝑐𝑐 = ∆𝑉𝑉𝑑𝑑 𝐼𝐼 (7) dimana: rc : tahanan kontak (ω) vd : tegangan jatuh (volt) i : arus (a) permasalahan yang timbul dalam pengukuran tahanan kontak antara dua logam adalah adanya efek termal emf atau termoelektrik. adanya termoelektrik ini dapat mempengaruhi tingkat akurasi pengukuran tahanan kontak. besarnya termoelektrik tergantung pada besarnya arus pengujian dan lamanya pembebanan arus. jadi dalam hal ini pengukuran tahanan kontak dengan menggunakan persamaan (7) merupakan pengukuran tahanan kontak yang masih ada pengaruh termoelektrik. oleh karena itu untuk menghilangkan efek termoelektrik ini maka dilakukan pengukuran dengan membalikan polaritas arus pengujian. pengukuran dilakukan dengan cara memberikan arus dc (if) ke sambungan busbar melalui 2 kawat ke ujung titik sambungan, dan ukur tegangan jatuh di titik tersebut dengan voltmeter (∆vf) yang terhubung dengan 2 kawat. kemudian sample dialirkan arus dc (ir) kembali namun polaritasnya diubah dan ukur kembali tegangan jatuh di titik tersebut dengan voltmeter (vr). dan untuk menentukan tahanan kontak (rc) dilakukan dengan menggunakan persamaan (8) [12]. 𝑅𝑅𝑐𝑐 = �𝑉𝑉𝑓𝑓�+|𝑉𝑉𝑟𝑟 | �𝐼𝐼𝑓𝑓�+|𝐼𝐼𝑟𝑟 | (8) dimana: rc : tahanan kontak (ω) vf : tegangan forward (volt) vr : tegangan reverse (volt) if : arus forward (a) ir : arus reverse (a) pengukuran dengan metode ini akan mendapatkan hasil yang lebih akurat karena dapat meminimalisir pengaruh termoelektrik atau emf. beberapa standar internasional juga merekomendasikan metode ini seperti astm dan eia. hasil pengukuran tahanan kontak dengan menggunakan persamaan (7) dan persamaan (8) kemudian dibandingkan untuk mengetahui tingkat akurasi dari pengukuran. tahap kedua dilakukan pengujian sambungan busbar dengan pembebanan arus tinggi yaitu 350 a. pengujian ini dilakukan untuk mengukur temperatur maksimum sambungan busbar pada tekanan kontak 12, 24, dan 36 mpa. gambar 8 merupakan rangkaian pengujian arus untuk mengetahui kenaikan temperatur sambungan busbar; (1) power supply, (2) potensiometer, (3) amperemeter, (4) trafo arus, (5) tang ampere, (6) sampel, (7) termometer. mula-mula sumber arus ac dialirkan melalui power supply, agar beban arus ac yang dibutuhkan sesuai pengujian yaitu 350 a, maka arus diperbesar dengan trafo arus. besarnya arus pengujian yang dialirkan pada sampel harus diatur dan dijaga konstan sebesar 350 a selama waktu pengujian yaitu sekitar 60 menit, dimana kenaikan temperatur dipantau dan dicatat pada setiap interval 5 menit sekali sampai mencapai steady state. (a) (b) gambar 7. (a) penambahan tekanan kontak; (b) pengujian tahanan kontak dengan metode 4 kawat. a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 79 iv. hasil dan pembahasan a. hasil pengukuran tahanan kontak sambungan busbar tembaga pengukuran tahanan kontak sambungan busbar tembaga merupakan tahap pertama yang dilakukan dalam pengujian ini. hal ini dilakukan untuk mengetahui seberapa besar pengaruh tekanan terhadap tahanan apabila dilalui arusarus yang relatif kecil. dari grafik pada gambar 9 dan 10 dapat diperhatikan bahwa peningkatan tekanan kontak dari 6 – 30 mpa dapat menyebabkan nilai tahanan kontak berkurang dari 16 – 11 µω dengan penurunan rata-rata 0,2 µω/mpa. peningkatan tekanan kontak dari 30 mpa ke atas, nilai tahanan kontaknya relatif tidak berubah yaitu dikisaran 11 µω yang merupakan tahanan maksimal terkecil yang dapat diusahakan. gambar 9 merupakan hasil pengukuran tanpa menghilangkan efek termoelektrik yaitu dengan menggunakan persamaan (7). hasil pengukuran tahanan kontaknya untuk rating arus yang berbeda tidak sama. hal ini juga bisa dilihat dari bentuk kurva yang memiliki simpangan yang besar pada pengujian rating arus yang berbeda. sedangkan gambar 10 merupakan hasil pengukuran dengan menghilangkan efek termoelektrik menggunakan persamaan (8). hasil pengukuran tahanan kontaknya untuk rating arus yang berbeda tidak menunjukkan adanya simpangan yang lebih besar. dengan demikian metode pengukuran ini lebih menghasilkan hasil pengukuran yang lebih akurat. b. hasil pengukuran temperatur kontak hasil pengukuran temperatur kontak dari ketiga jenis sampel dengan variasi tekanan kontak 12, 24, dan 36 mpa. besarnya pembebanan arus bolak-balik 350 a, dengan waktu pembebanan selama 60 menit. hasil pengukurannya ditunjukkan pada gambar 11. pada gambar 11 dapat diperhatikan bahwa pada tekanan kontak 12, 24, dan 36 mpa temperatur maksimum masing-masing adalah 58°c, 55°c, dan 54°c. waktu yang diperlukan untuk mencapai kondisi temperatur steady ratarata yaitu di kisaran 40-50 menit. selisih temperatur maksimum terkecil dari sambungan busbar terhadap temperatur referensi (busbar tanpa sambungan) adalah 5°c. maka dengan bertambahnya tekanan kontak pada sambungan sampai tingkat tertentu dapat menurunkan temperatur maksimum sambungan. (a) (b) gambar 8. pengujian temperatur busbar (a) rangkaian; (b) foto. gambar 9. grafik karakteristik tahanan kontak tanpa memperhatikan efek termoelektrik. gambar 10. grafik karakteristik tahanan kontak dengan memperhatikan efek termoelektrik. a. risdiyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 73-80 80 v. kesimpulan dengan meningkatnya tekanan kontak pada sambungan busbar maka nilai tahanan kontaknya akan semakin kecil dan temperatur maksimum sambungannya akan menurun pula. peningkatan tekanan kontak dari 6 sampai 30 mpa menurunkan nilai tekanan kontak dari 16µω sampai 11µω. peningkatan tekanan kontak pada tekanan lebih dari 30 mpa tidak menyebabkan kenaikan tahanan kontak secara signifikan. temperatur terendah sambungan busbar adalah 54°c dan dicapai pada tekanan kontak 36 mpa. untuk mengukur atau menghitung tahanan kontak sambungan, pemberian arus kecil hendaknya dilakukan dengan menyertakan polaritas yang berbeda. dalam hal ini efek termoelektrik yang dihasilkan dari arus forward if akan dinetralisir oleh arus reverse ir. dengan menghilangkan efek termoelektrik pengukuran tahanan kontak akan menghasilkan nilai yang relatif sama meskipun dengan pemberian arus yang berbeda-beda, sehingga hasil pengukuran akan lebih akurat. referensi [1] braunovic, m., konchits, v.v., myshkin, n.k., “electrical contacts fundamentals, applications and technology,” crc press, taylor and francis group, isbn: 1-57444727-0, 2006. [2] bhattacharyya, s., choudhury, a., jariwala, h.r., shetty, m.s., rajulkumar, ”maintaining low resistance in conductive joints,” international journal of computer and electrical engineering, vol. 3, no. 6, december 2011. [3] suwarno, ”material elektroteknik,” institut teknologi bandung, megatama, isbn: 97999701-1-3, 2006. [4] popa, i., cautil, i., floricau, d., ocoleanu, f., ”modelling and optimization of high currents dismountable contacts,” international conference on electromechanical and power systems, chisinau, rep. moldova, 2007. [5] bhattacharyya, s., choudhury, a., jariwala, h.r., shetty, m.s., rajulkumar, ”electrical performance of conductive bolted joints of copper and aluminum busbars,” int j engg techsci, vol. 2(4), 2011. [6] farahat, m.a.,”factors affecting the life time of the electric joints,” proceedings of the 14th international middle east power systems conference (mepcon’10), cairo university, egypt, december 19-21, 2010. [7] braunovic, m., ”reliability of power connections,” journal of zhejiang university science a, issn 1009-3095, pp. 343-356, 2007. [8] chen, h.l., tseng, k.c., yang, y.s., ”effect of the oxide film formed on the electrical properties of cu-zn alloy electric contact material,” the 4th international conference on technological advances of thin film and surface coatings, 2008. [9] standar nasional indonesia, persyaratan umum instalasi listrik, sni 04-0225-2000, badan standarisasi nasional (bsn), jakarta, 2002. [10] medora, n.k., connection technology, chapter 17, electronic failure analysis handbook, mcgraw-hill, 2004. [11] ansi, test method for dc contact esistance, drop cable to f-connectors and f81 barrels, ansi/scte 103 2004, american national standard, 2004. [12] astm, standard test methods for measuring resistance of electrical connections (static contacts), astm b53902, west conshohocken, pa, 19428-2959 usa, 2008. gambar 11. grafik karakteristik temperatur sambungan busbar tembaga pada tekanan kontak 12, 24, 36 mpa dan busbar tanpa sambungan beban arus 350 a selama 60 menit. mev mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.81-86 the effect of the addition of active digester effluent for start-up accelerator in anaerobic digestion of soybean curd industry waste water (basic research for biogas power generation) pengaruh penambahan effluent digester aktif untuk mempercepat start-up peruraian anaerobik air limbah industri tahu (riset dasar pembangkit listrik tenaga biogas) arini wresta a, b, *, wiratni budhijanto a a laboratory of food and bioprocess engineering, chemical engineering department faculty of engineering, gadjah mada university, jl. grafika 2, yogyakarta 55281 indonesia b research centre for electrical power and mechatronics-indonesian institute of sciences, jl. cisitu no. 21/154 d, bandung 40135 indonesia received 05 october 2012; received in revised form 23 october 2012; accepted 12 november 2012 published online 18 december 2012 abstract biogas production from soybean curd industry waste water was studied in laboratory scale to improve the application of anaerobic digestion process. the problem with the soybean curd waste water was the fact that it does not sufficiently contain anaerobic microorganisms required in biogas production. therefore, it is necessary to add a well-developed population of anaerobic microorganisms to accelerate the start-up of the anerobic digestion. this research was aimed to verify the influence of the addition of active digester effluent into the soybean curd waste water batches in an anaerobic digestion process. batch experiments were done in two digesters. the first digester was only fed with soybean curd waste water while the second digester was fed with soybean curd waste water and active digester effluent from a digester processing cow manure which was very rich in anaerobic microorganism consortium. the results indicated that soybean curd industry waste water did not contain methanogenic bacteria but there existed some acidogenic bacteria. the addition of active digester effluent accelerated the anaerobic digestion start-up and directed the process pathway towards methanogenic process so that more methane was obtained. the high methane content obtained (more than 64% volume) was very potential for power generation. the capacity of soybean curd industry must be as high as 697.13 kg soybean per day to generate the electric energy of 8.4 kwh. key words: active digester effluent, start-up, anaerobic digestion, soybean curd waste water, anaerobic bacteria, methanogenic process, electric energy. abstrak untuk memperluas aplikasi proses peruraian anaerobik, telah dilakukan proses pembuatan biogas skala laboratorium dengan substrat air limbah industri tahu. masalah yang dihadapi adalah sedikitnya bakteri-bakteri anaerobik di dalam air limbah tersebut. oleh karena itu, untuk mempercepat start-up pembuatan biogas diperlukan starter yang banyak mengandung bakteri-bakteri anaerobik. penelitian ini bertujuan untuk menguji pengaruh penambahan effluent digester aktif sebagai starter pada peruraian anaerobik air limbah tahu. penelitian dilakukan dalam dua buah digester batch berisi 600 gram bahan baku, dimana digester pertama berisi air limbah tahu saja dan digester ke-2 berisi air limbah tahu dan starter effluent digester kotoran sapi aktif yang sangat kaya akan konsorsium bakteri-bakteri anaerobik. hasil percobaan menunjukkan bahwa air limbah tahu mengandung bakteri asidogen tetapi tidak mengandung bakteri metanogen. penambahan effluent digester aktif sebagai starter mempercepat star-up peruraian anaerobik dan mengarahkan jalannya proses ke metanogenesis sehingga diperoleh produk akhir berupa metana. kadar metana yang dihasilkan mencapai di atas 64% sehingga sangat potensial untuk pembangkit listrik. energi listrik sebesar 8,4 kwh dapat dibangkitkan dari industri tahu dengan kapasitas 697,13 kg kedelai per hari. kata kunci: effluent digester aktif, start-up, peruraian anaerobik, air limbah tahu, bakteri anaerobik, metanogenesis, energi listrik. * corresponding author. tel: +62-22-2503055 e-mail: awresta@gmail.com http://dx.doi.org/10.14203/j.mev.2012.v3.81-86 a. wresta and w. budhijanto / mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 82 i. introduction as a country that rich of organic resources also known as biomass, indonesia has started to encourage biogas technology as an alternative renewable energy. the simple process, environmently friendly maintenance, and low cost investment are the strength of this bio fuel. in the long run, when the fossil fuel crude oil and natural gas is not available anymore, biogas will be one of the crucial energy source in the world. puslit telimek lipi has applied cow manure biogas production for electricity since 2008 until now by iptekda program (2008, 2010, 2011), pkpp dikti program (2009), ristek speklok program (2011), and pkpp ristek program (2012). the advantage of cow manure as the anaerobic digestion feed is its content of anaerobic bacteria that will trigger the process to run well without the addition of any starters. however, the data taken from biogas digester installation in pesantren saung balong al barokah majalengka indicated that the anaerobic digestion process of the cow manure was not satisfying because just little power can be generated caused by the little gas produced from the digester [1]. this field finding implied that even for cow manure, additional starter might be necessary to quickly recover the digester from the problem. the laboratory research of biogas formation from the waste water of soybean curd industry was done in laboratory of food and bioprocess engineering, chemical engineering, gadjah mada university, as the first author’s thesis. the final goal of this research was to develop the expand of biogas production application possibility for electricity in puslit telimek lipi with anothers sources of substrate. this paper specifically reports the effect of active digester effluent as a starter in soybean curd waste water for biogas production. this research will also estimate the amount of soybean curd industry waste water needed to generate a certain amount of electric power. the other parameters that affect the utilization of soybean curd waste water as anaerobic digestion substrate will be discussed in another publication. ii. fundamental a. biogas formation and the bacteria involved biogas formation is a microbiology process that involves a consortium of anaerobic bacteria. this process utilizes anaerobic bacteria metabolism activity to get the energy needed for their live. for this need, the bacteria degrade organic compounds and take the energy released from the process. the side products are simple compounds and biogas, mainly contain of ch4 and co2. the methane content in the biogas can achieve 70% volume of all gas produced [2]. this gas exhibits high energy value and can be used as fuel. biogas production process has been used since long time ago to get the alternative energy that can substitute crude oil and natural gas. biogas production process consist of hydrolysis, acidogenic, and methanogenic steps [3]. hydrolysis is the degradation of unsoluble complex organic compounds by anaerobic and facultatively anaerobic bacteria. the products of this step are soluble simple organic compounds. the simple organic compounds then be utilized by acidogenic bacteria to produce short-chain fatty acids. methanogenic bacteria then use this acids as substrate and convert them into ch4 and co2. the bacteria involved in hydrolysis and acidogenic steps are obligatorily and facultatively anaerobic bacteria, but the majority are facultative [4]. facultative anaerobes are active in the presence or absence of free molecular oxygen [5]. the optimal ph and temperature for acidogenic bacteria are t = 35°c and ph = 4-6 [3]. methanogenic bacteria are strict anaerobes, that will die in the presence of free molecular oxygen [5]. the optimal ph and temperature of methanogenic bacteria are t = 35 to 40°c and ph = 7 to 8 [3]. the methanogenic bacteria is very sensitive with environmental condition change. in order to get the desired product (ch4), all of the syntropic bacteria have to be exist in the biogas system. the absence of one group of bacteria involved in one step will cause the process uncomplete and the desired product is not formed. b. anaerobic digestion of soybean curd waste water and active digester effluent as a starter many researches have been done to utilize industrial waste water containing organic compound as source of substrate for biogas formation. some of them are kavacik and topaloglu (2010) research in co-digestion of cheese whey and dairy manure [6], ward (2010) research in co-digestion of cow manure and stearin [7], and damayanti (2010) research in codigestion of stillage and cow manure [8]. these researches studied co-digestion process in which the waste water was mixed with manure, so that there are anaerobic bacteria involved in biogas formation existed. however, not all industries locations are closed to the animal farms, and for a. wresta and w. budhijanto / mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 83 this industries it is needed a method to make the methane formation from the waste run well without the continuous addition of the manure. one of industrial waste water that is potential to be used as anaerobic digestion substrate is the waste water from soybean curd industry. this waste water is a scrap waste water from protein coagulation in soymilk [9]. the protein and lipid content up to 70% of all organic compound in this waste water [10], so that according to buswell equation [11], this waste water potentially produce great number of gas with high methane content. there are five steps in soybean curd formation process, i.e. washing, grinding, cooking, filtration, and coagulation [9]. soybean curd is obtained after the protein coagulation with the addition of acid, so that the waste water produced have low ph value approximately of 4-5 [12]. the opened soybean curd formation process and the low ph value of the waste water cause the methanogenic bacteria did not grow in this waste. however, the acidogenic bacteria can potentially grow in this waste water because the bacteria are facultatively anaerobic and like to grow in the medium having low ph value. due to the low existence of the methanogenic bacteria in the soybean curd waste water, the methanogenic process will not immediately happen in anaerobic digestion of this waste water without the addition of starter containing many methanogenic bacteria. for this purpose, active digester effluent may be used as a starter. there are acidogenic and methanogenic bacteria in this effluent. sufficiently high amount methanogenic bacteria may exist in this effluent, because this starter is produced from anaerobic digestion process that has successfully produce methane. c. the calculation of the potentiality for power generation biogas electric power is generated by utilize the energy released from the combustion of methane in the biogas. this energy than be converted to electricity using a device named as gen-set. the energy that can be generated is calculated by: 𝐸𝐸 = 𝜂𝜂. 𝑛𝑛. ∆𝐻𝐻𝑐𝑐 (1) where e is the energy potentially generated from biogas gen-set (joule), n is the amount of methane obtained from the biogas digester fed with m kg of substrate (mole), and ∆𝐻𝐻𝑐𝑐 is the heat of combustion of methane (802,620 joule/mole [13]). the methane obtained from the biogas digester is calculated by ideal gas law: 𝑛𝑛 = 𝑃𝑃′.𝑉𝑉 𝑅𝑅𝑇𝑇 (2) where p’ is pressure (atm), v is methane volume obtained, r is ideal gas constant (0.082 lt.atm/mole.k), and t is temperature (k). if the power to be generated is p (watt) and the generating time is t (seconds), the energy that must be provided to generate the power (ed, joule) is: 𝐸𝐸𝑑𝑑 = 𝑃𝑃 × 𝑡𝑡 (3) the amount of substrate which must be fed in to the digester to generate the power (m, kg) is: 𝑀𝑀 = �𝐸𝐸𝑑𝑑 𝐸𝐸 � × 𝑚𝑚 (4) iii. experimental soybean curd waste water used in this research was the soybean curd whey from homescale soybean curd industry in village of jetis, tirtomartani, kalasan, sleman, indonesia. analysis results showed the total anaerobic bacteria concentration of 4 x 106 cells/ml, ph value of 4, volatile solid (vs) concentration of 5.8382 g/l, and volatile fatty acids (vfa) concentration of 509.4897 mg/l as acetic acid. active digester effluent used in this research is got from cow manure biogas installation in kebun pendidikan, penelitian, dan pengembangan pertanian universitas gadjah mada (kp4 ugm), in berbah, sleman, yogyakarta, indonesia. analysis results showed the anaerobic bacteria concentration of 27 x 108 cells/ml, ph value of 7, vs concentration of 17.3160 g/l, and vfa concentration of 332.2962 mg/l as acetic acid. biogas digester was 1,000 ml erlenmeyer flask, connected with gas bubbler to detect the gas formed from the digester. gas bubbler was connected with water manometer to measure the volume of gas formed. the experimental set up is represented in figure 1. batch experiment was conducted in room temperature (ranged between 29-30°c during the experiments). two digesters were fed with 600 gram raw material. the first digester only contained soybean curd waste water while the second digester contained 400 gram soybean curd waste water and 200 gram cow manure active digester effluent. after all of the material were fed into the digester, nitrogen gas was flushed to remove the air in the digester gas space. sludge and gas sample was taken weekly for vs and vfa analysis according to standard method [14] and ch4 analysis using gc (shimadzu gc 14b, japan, with fid detector, sus packed column a. wresta and w. budhijanto / mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 84 porapak q, 5m x 3mm i.d., 50°c column oven temperature, and 170 kpa inlet pressure). the volume of gas formed was measured every day by recording the water level difference at the manometer legs. iv. results and discussions a. the effect of the addition of active digester effluent the experimental results are presented in figure 2. figure 2a shows the correlation between vs concentration and time. the vs concentration in the digester with the addition of active digester effluent as a starter decreased earlier than in the digester without starter addition indicating the earlier organic compounds degradation and vfa formation by acidogenic bacteria. vfa concentration in the digester with starter addition increased quickly since the initial process (figure 2b). this phenomena indicated the earlier organic degradation start-up that may happen because the acidogenic bacteria are also existing in the active digester effluent. the acidogenic bacteria in the starter are more welldeveloped than those in the soybean curd waste water so that the addition of this starter caused a significant effect in the organic compounds degradation rate. the fast organic compounds degradation in the digester with starter addition implied in the high production of vfa. vfa concentration reached more than 1,500 mg acetic acid/l at day 6. in agreement with karakhasev, et al. (2005) statement that the dominant bacteria in the sludge digester are methanosaetaceae [15], the high vfa concentration in this digester provides enough substrate for methanosaetaceae methanogenic bacteria so that the methane cumulative volume produced is high (figure 2c), as high as more than 450 ml in day 18. the additional methanogenic bacteria from the active digester effluent caused the fast methane formation, but the low soybean curd waste water ph value caused methanogenic bacteria need long time to adaptate. methane formation start-up began in day 5, which was much faster to be compared with the digester without starter addition that took 20 days for the methanogenic bacteria to kick-off. the methane content in the biogas was sufficiently high, i.e. reached more than 64% volume in day 18 (figure 2d). the residual protein and lipid in the soybean curd waste water caused the high methane content in the gas produced. this value was higher than if cow manure used as source of substrate as high as 53.0003% [8], so that this biogas has high energy value and very potential for power generation. the high methane content will impact in gen-set efficiency especially in voltage value [16]. the organic compounds degradation in the digester without starter addition is later, caused by the few acidogenic bacteria in the soybean curd waste water (figure 2a). anaerobic bacteria concentration in this waste water was 4x106 cells/ml, much lower than the anaerobic bacteria in the active digester effluent about 27x108 cells/ml. however, the differences of organic compounds degradation in the digester with starter addition and in the digester without starter addition can not be seen clearly in figure 2a caused by the difficulty to analyze the vs concentration accurately, especially in the low concentration. this degradation can be seen more clearly in the trend of vfa concentration. the later organic compound degradation would imply in the later vfa formation. figure 2b show that the vfa formation in the digester without starter addition did not happen in some initial days, and the vfa concentration start increased quickly in day 12 process. in this start-up time (day 12) the acidogenic bacteria amount may have been high enough as the result from the growth in the time before. the highest vfa concentration was reached in day 28 about 1,391.37 mg acetic acid/l. the vfa concentration in the digester without starter was not significant different with the vfa concentration in the digester with starter (figure 2b), but the methane formation didn’t happen in this digester until day 33 process (figure 2c and 2d). the methane content and cumulative volume were still 0 until the end process. this phenomena acknowledge the figure 1. experimental set up. a. wresta and w. budhijanto / mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 85 hypothesis that there was no methanogenic bacteria in the soybean curd waste water caused by the low ph value and the opened soybean curd formation process. b. the potentiality for power generation this section will study the power potentially can be generated from the biogas and estimate the soybean curd waste water that must be provided as anaerobic digestion substrate to generate a certain amount of power. the calculations are done using equation (1), (2), (3), and (4). experiment result showed that approximately of 467.065 ml methane was produced from biogas digester fed with 400 gram soybean curd waste water. with the assumption that the genset efficiency is 50%, the energy that can be generated from the biogas will be 7,543.985 joule. to generate power as high as 0.7 kw and as long as 12 hours (8.4 kwh) per day, the energy that must be generated is 30,240,000 joule or it is needed approximately of 1,603.39658 liters soybean curd waste water per day to be fed in to the biogas digester. due to the amount of waste water produced from this industry (soybean curd industry with capacity of 100 kg soybean per day will produce waste water approximately of 170290 liters [17]), the capacity of the soybean curd industry must be as high as 697.13 kg soybean per day to generate the power. this calculation result show that the soybean curd waste water biogas electric power can be generated from the large scale soybean curd industry. v. conclusions analysis result show that acidogenic and methanogenic bacteria were existed in the active digester effluent and no methanogenic bacteria existed in the soybean curd waste water. the addition of active digester effluent will accelerated the degradation start-up time and direct the process to methane formation so that the final product obtained will be methane. the high methane content obtained (more than 64%) is much higher than if cow manure used as source of substrate as high as 53.0003%, so that this biogas very potential for power generation. the capacity of soybean curd industry must be as high as 697.13 kg soybean per day to generate the soybean curd waste water biogas electric energy of 8.4 kwh. (a) (b) (c) (d) figure 2. the correlation of process parameters and time. 0 2 4 6 8 10 12 0 10 20 30 40 [v s] , g /l time, day with starter without starter 0 200 400 600 800 1000 1200 1400 1600 1800 2000 0 10 20 30 40 [v fa ], m g as et ic a ci d/ l time, day without starter with starter 0 100 200 300 400 500 600 0 10 20 30 40 m et ha ne c um ul at iv e, m l time, day without starter with starter 0 10 20 30 40 50 60 70 0 10 20 30 40 m et ha ne c on te nt ,% time, day with starter without starter a. wresta and w. budhijanto / mechatronics, electrical power, and vehicular technology 03 (2012) 81-86 86 further suggestion, the research to study the anaerobic co-digestion process of the waste water and the solid waste produced from soybean curd industry is needed to increase the yield of biogas and estimate the potentiality for biogas power generation in home and mid-scale soybean curd industry. acknowledgement the authors would like to thank to the ministry of research and technology, indonesia for the funding support by postgraduate scholarship program 2009-2011. this research is also funded by the national research excellence fund (rusnas) 2010 from the directorate of higher education, the ministry of national education, indonesia for dr. wiratni budhijanto as the principal researcher. the authors also like to thank to head of research centre for electrical power and mechatronics, also to aep saepudin, m.t. references [1] arifin, m., saepudin, a., santosa, a., “study of biogas for power generation at pesantren saung balong al-barokah, majalengka, west java”, journal of mechatronics, electrical power, and vehicular technology, vol. 02, no. 2, pp. 73-78, 2011. [2] tortora, g. j., funke, b. r., case, c. l., microbiology, an introduction. 10th ed., united state: pearson benjamin cummings, pearson education inc. 2010. [3] shuler, m. l.,kargi, f., bioprocess engineering basic concepts. 2nd ed., new jersey: prentice hall ptr, prentice-hall, inc., 2002, pp. 499-500. [4] deublin, d., steinhauser, a., biogas from waste and renewable resources, weinheim: wiley-vch verlag gmbh and co. kgaa, 2008. [5] gerardi, m. h., the microbiology of anaerobic digesters. 1st ed., new jersey: john wiley and sons, inc., 2003, pp. 89. [6] kavacik, b., topaloglu, b., “biogas production from co-digestion of a mixture of cheese whey and dairy manure”, biomass and bioenergy, volume 34, pp.1321-1329, september, 2010. [7] ward, a. j., ”biogas potential of fish wax with cattle manure”, department of biosystems engineering, faculty of agricultural sciences, university of aarhus, internal report-animal science, 2010. [8] damayanti, s. i., ”pemanfaatan stillage menjadi biogas melalui proses codigestion stillage dan kotoran sapi”, program studi teknik kimia, kelompok bidang ilmu-ilmu teknik, program pascasarjana universitas gadjah mada, yogyakarta, tesis, 2010. [9] kaswinarni,f., ”kajian teknis pengolahan limbah padat dan cair industri tahu”, program studi magister ilmu lingkungan, program pascasarjana universitas diponegoro, semarang, tesis, 2007. [10] nurhasan dan pramudyanto, pengolahan air buangan industri tahu, semarang: yayasan bina lestari dan walhi, 1987, hal. 37. [11] jordening, h. d., winter, j., environmental biotechnology, weinheim, germany: wileyvch verlag gmbh & co. kgaa, 2005. [12] said, n. i., wahjono, h. d., ”teknologi pengolahan air limbah tahu-tempe dengan proses biofilter anaerob dan aerob”, kelompok teknologi pengelolaan air bersih dan limbah cair, direktorat teknologi lingkungan, badan pengkajian dan penerapan teknologi, jakarta, 1999. [13] green, d. w., perry, r. h., perry’s chemical engineers’ hand book. 8th ed., new york: mcgraw-hill companies inc., 2008. [14] eaton, a.d., clesceri, l.s., rice, e.w., and greenberg, a.e., standard methods for the examination of water and wastewater. 21st ed.,washington dc: apha, awwa, and wef, 2005. [15] karakashev, d., ”effect of environmental condition on methanogenic composition”, appl. environ. microbiol, 17, pp. 331-338, 2005. [16] wahono, s. k., maryana, r., kismurtono, m., “biogas purification process to increase –gen-set efficiency”, international workshop on advanced material for new and renewable energy, american institute of physics, 2009. [17] romli, m., suprihatin, “beban pencemaran limbah cair industri tahu dan analisis alternatif strategi pengelolaannya”, jurnal purifikasi, vol. 10, no. 2, pp. 141-154, 2009. mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by national research and innovation agency (brin) formerly indonesian institutes of sciences (lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: https://mev.lipi.go.id all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev is sinta 1 accredited by kementerian pendidikan, kebudayaan, riset, dan teknologi republik indonesia via national journal accreditation (arjuna) accreditation platform. https://sinta.kemdikbud.go.id/j ournals/profile/814 postal address mev journal secretariat: research center for smart mechatronics, national research and innovation agency (brin) kst samaun samadikun brin jl. sangkuriang, dago, kec. coblong, bandung, west java, 40135 indonesia business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: jmev@brin.go.id https://mev.lipi.go.id/ https://sinta.kemdikbud.go.id/journals/profile/814 https://sinta.kemdikbud.go.id/journals/profile/814 mailto:jmev@brin.go.id journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: https://mev.lipi.go.id/mev/login need a username/password? go to registration at: https://mev.lipi.go.id/mev/user/r egister registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate®. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. mev has been indexed in scopus and the profile page can be visited at https://www.scopus.com/sourcei d/21101101245 cc license mev journal by national research and innovation agency (brin) allows reuse and remixing of its content under a cc by-ncsa creative commons attribution-noncommercialsharealike 4.0 international license. permissions beyond the scope of this license may be available at https://mev.lipi.go.id. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nclicensed work does not necessarily mean you have violated the term. https://mev.lipi.go.id/mev/login https://mev.lipi.go.id/mev/user/register https://mev.lipi.go.id/mev/user/register https://www.scopus.com/sourceid/21101101245 https://www.scopus.com/sourceid/21101101245 http://www.brin.go.id/ http://www.brin.go.id/ http://www.brin.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 editor-in-chief dr. haznan abimanyu, dip.ing. research organization for energy and manufacture brin indonesia associate editor (main handling editor) yanuandri putrasari, ph.d. research center for smart mechatronics – brin indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, malaysia prof. dr. estiko rijanto research center for smart mechatronics – brin, indonesia prof. tapan kumar saha electrical engineering, the university of queensland, australia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, universitas sebelas maret surakarta, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology, japan prof. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, indonesia prof. dr. bambang riyanto trilaksono school of electrical engineering and informatics, bandung institute of technology, indonesia prof. keum shik hong dept. of mechanical engineering, pusan national university, korea, republic of prof. taufik director of electric power institute, california polytechnique, united states prof. dr. adi soeprijanto dept. of electrical engineering, institut teknologi sepuluh nopember (its), indonesia assoc. prof. hazim moria department of mechanical engineering, yanbu industrial college, saudi arabia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, australia assoc. prof. roonak daghigh university of kurdistandisabled, sanandaj, iran, islamic republic of asst. prof. mohammad h. yazdi mechanical eng. dept., islamic azad university, iran, islamic republic of dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales, australia dr. ahmad fudholi solar energy research institute, universiti kebangsaan malaysia, malaysia dr. ali h.a. al-waeli solar energy research institute, universiti kebangsaan malaysia, malaysia george anwar, ph.d. university of california, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia, indonesia riza muhida, ph.d. information system, bandar lampung university, indonesia dr.eng. budi prawara research organization for electronics and informatics – brin, indonesia advisory editor prof. ocktaeck lim school of mechanical engineering, university of ulsan, korea, republic of prof. dr. endra joelianto engineering physics, bandung institute of technology, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 © 2023 national research and innovation agency. some rights reserved. this journal and the individual contributions contained in it are protected under copyright by national research and innovation agency. and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 foreword from editor-in-chief most valued readers, welcome to the 1st issue of volume 14 in the year 2023 of the journal of mechatronics, electrical power, and vehicular technology (mev), a peer-reviewed and broad-scope international journal. this journal aims to bridge the gap in mechatronics, electrical power, and vehicular technology and is designed to advance scientific knowledge and foster innovative engineering solutions. it addresses both academics and practicing professionals, which has become an increasingly recognized international journal in the past years. this issue consists of ten papers written by authors from different countries, such as greece, indonesia, united kingdom, japan, netherland, usa, hungary, and vietnam. we are pleased in this issue to present a diverse range of articles and papers that cover a wide range of topics within the field of mechatronics, electrical power, and vehicular technology. the first paper a control system algorithm for a five-axis pms cnc milling machine based on a 6-dof stewart platform parallel manipulator with a universal-prismatic-spherical (ups) configuration. lampropoulos, the author of second paper analysis includes 1,926 articles that were identified and retrieved from scopus and web of science (wos) over the period 2005 to 2022 with the aims to explore the use of artificial intelligence in smart grids and how the topic has evolved over the years. the third paper calculate the 480-kw squirrel cage induction motor (scim) design for the electric multiple unit (emu) train. while, tamba, et al. presents in their work a sum of squares (sos) polynomial optimization approach for stability analysis of a hybrid model of buck converter which explicitly takes into account the converter’s electronic switching behavior. similar to second paper, irawan, et al. used bibliometric analysis to determine the growth of vertical axis wind turbine (vawt) research, the number of vawt studies in various countries and the most influential authors to find opportunities for research collaboration, and the challenges of future vawt research. research data was taken from scopus in 1801 articles from 1970-2021. the next article has one of the objectives to see the maximum impact of installing a photovoltaic rooftop at 1 point of customer and spread capacity for each customer. a model for forecasting the number of vehicles arriving at the battery swap station was designed by the authors of the seventh paper. the next paper is also talking about design and implementation of capacitor array as dc converters for electrical lighting in limited area. sukra, et al. studied about impact of road load parameters on vehicle co2 emissions and fuel economy: a case study in indonesia. the last paper shows analysis of lithium-ion battery packs failures in electric vehicles based on fmea. each issue of this journal offers valuable reports and articles to the practitioners and research experts. we encourage academic and research professionals to submit manuscripts on practical and scientific key issues in mechatronics, electrical power, and vehicular technology of all disciplines. we are looking forward to receiving extraordinary manuscripts and promoting cutting-edge technology development. bandung, july 2023 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 ii list of contents five-axis parallel mechanism system (pms) cnc partial link control system based on modified inverse kinematic of 6-dof ups parallel manipulator nur jamiludin ramadhan, indrawanto, hoe dinh nguyen .......................................................... 1-10 artificial intelligence in smart grids: a bibliometric analysis and scientific mapping study georgios lampropoulos ........................................................................................................................ 11-34 an optimized stator and rotor design of squirrel cage induction motor for emu train hilda luthfiyah, okghi adam qowiy, arga iman malakani, dwi handoko arthanto, fauzi dwi setiawan, teddy anugrah ramanel, gilang mantara putra, syamsul kamar, asep andi suryandi .......................................................................................................................................... 35-46 stability analysis of a hybrid dc-dc buck converter model using dissipation inequality and convex optimization tua a. tamba, jonathan chandra, bin hu ........................................................................................ 47-54 analyzing the growth and trends of vertical axis wind turbine research: insight from a bibliometric study elysa nensy irawan, nuur wachid abdul majid, liptia venica, fahrur aslami, goro fujita ................................................................................................................................................ 55-61 quasi-dynamic hosting capacity in radial distribution feeder riki khomarudin, kevin marojahan banjar-nahor, nanang hariyanto .................................. 62-71 lstm-based forecasting on electric vehicles battery swapping demand: addressing infrastructure challenge in indonesia muhammad zakiyullah romdlony, rashad abul khayr, aam muharam, eka rakhman priandana, sudarmono sasmono, muhammad ridho rosa, irwan purnama, amin, ridlho khoirul fachri ................................................................................ 72-79 design and implementation of capacitor array as dc converters for electrical lighting in limited area arman jaya, irianto, afif aulia rahman, kyungmin sung ........................................................... 80-86 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 iii impact of road load parameters on vehicle co2 emissions and fuel economy: a case study in indonesia kurnia fajar adhi sukra, heru priyanto, dedy indriatmono, muhamad agus wijayanto, irfan yahya ikhsanudin, yoga akbar ermansyah........................................................................... 87-93 failure assessment in lithium-ion battery packs in electric vehicles using the failure modes and effects analysis (fmea) approach rizky cahya kirana, nicco avinta purwanto, nadana ayzah azis, endra joelianto, sigit puji santosa, bentang arief budiman, le hoa nguyen, arjon turnip ................................... 94-104 complete articles can be found at https://mev.lipi.go.id https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 14, issue 1, 2023 iv abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. nur jamiludin ramadhan a, indrawanto b, hoe dinh nguyen c (a department of manufacturing automation and mechatronics engineering, bandung polytechnic for manufacturing, indonesia; b faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia; c faculty of vehicle and energy engineering, phenikaa university, vietnam) five-axis parallel mechanism system (pms) cnc partial link control system based on modified inverse kinematic of 6dof ups parallel manipulator journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 1-10, 12 ill, 0 tab, 27 ref. this paper presents a control system algorithm for a fiveaxis parallel mechanism system (pms) cnc milling machine based on a 6-dof stewart platform parallel manipulator with a universal-prismatic-spherical (ups) configuration. the control system reads the g-code commands as standard cnc machine language, then extract data points and interpolates them to generate the robot trajectory patterns as motion references. then, the control system uses the modified inverse kinematic equation to determine the length of each link to move the end effector to track the trajectory patterns from the previous g-code extraction process. the inverse kinematic equation is modified especially for the five-axis pms cnc milling machine by including machine-offset and toolsoffset parameters so it will be easier for the control system to implement the kinematic equation. as expected, the system simulation results successfully followed the g-code program moving commands. the average error of the length control system is 0,1 mm, while the average error of the length change rate control system is 1,8 mm/s. the maximum error is 26.9 mm was caused by the system's inability to follow the motion profile in transient. it can be concluded that 6-dof stewart platform parallel structures, which provide better performance than serial structures, can be implemented as a new concept for the motion mechanism of five-axis cnc milling machines. the five-axis pms cnc milling machine also promises better performance than conventional five-axis gantry structures cnc. (author) keywords: stewart platform; parallel manipulator; parallel mechanism structure; machine tools; cnc control system. georgios lampropoulos a, b (a department of information and electronic engineering, international hellenic university, greece; b school of humanities, hellenic open university, greece) artificial intelligence in smart grids: a bibliometric analysis and scientific mapping study journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 11-34, 35 ill, 9 tab, 49 ref. the realization of sustainable development and sustainable development goals achievement are essential. hence, the power sector digitalization is imminent. this bibliometric and mapping study aims to explore the use of artificial intelligence in smart grids and how the topic has evolved over the years. in total, ten research questions are set to be explored. the analysis includes 1,926 articles that were identified and retrieved from scopus and web of science (wos) over the period 2005 to 2022. the analysis includes the descriptive statistics of the related studies and the annual scientific production, the identification of the most relevant and impactful authors, articles, outlets, affiliations, and countries, and the examination of the most commonly used keywords. the most popular topics and the advancement of the research focus are also explored. the study examines the results, discusses the main findings, presents open issues, and suggests new research directions. the significant role of artificial intelligence in the realization of smart grids and the digitalization of the power sector to enable sustainable development and the achievement of sustainable development goals was evident. (author) keywords: artificial intelligence; smart grid; power sector; renewable energy resources; sustainable development. hilda luthfiyah a, okghi adam qowiy a, arga iman malakani b, dwi handoko arthanto c, fauzi dwi setiawan a, teddy anugrah ramanel d, gilang mantara putra e, syamsul kamar a, asep andi suryandi f, g (a research center for transpostation technology, national research and innovation agency (brin), indonesia; b research center for journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 v hydronamics technology, national research and innovation agency (brin), indonesia; c research center for accelarator technology, national research and innovation agency (brin), indonesia; d research center for energy conversion and conservation, national research and innovation agency (brin), indonesia; e research center for artificial intelligence and cyber security, national research and innovation agency (brin), indonesia; f electrical and electronic engineering, the university of manchester, united kingdom; g research center for process and manufacturing industry technology, national research and innovation agency (brin), indonesia) an optimized stator and rotor design of squirrel cage induction motor for emu train journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 35-46, 17 ill, 7 tab, 27 ref. this paper aims to objectively calculate the 480-kw squirrel cage induction motor (scim) design for the electric multiple unit (emu) trains. this is done by optimizing the stator slot and rotor slot design to get efficiency and power factor targets. the stator slot design is achieved by limiting the width and height of the stator slot pitch according to the specified range. a depth-to-width ratio is used according to the range to optimize the design of the rotor bar slot. the design process of the induction motor consists of three steps: it determines the specification design target, calculates the specified parameters of the induction motor, and simulates the design to obtain the most optimal motor design using ansys maxwell. the simulation performance values obtained an efficiency of 92.547 % and a power factor of 0.915. this value is obtained from the optimization of the rotor slot and has met the minimum requirements of efficiency and power factor in designing a scim. the design proposed in this paper can be developed and applied in the indonesian domestic railway manufacturing industry. (author) keywords: squirrel cage induction motor; stator slot; rotor slot; motor efficiency; motor power factor. tua a. tamba a, jonathan chandra b, bin hu c (a dept. electrical engineering, parahyangan catholic university, indonesia; b dept. mechanical engineering, university of groningen, netherlands; c dept. computer engineering technology & science, university of houston, united states) stability analysis of a hybrid dc-dc buck converter model using dissipation inequality and convex optimization journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 47-54, 3 ill, 0 tab, 34 ref. the stability analysis of a dc-dc buck converter is a challenging problem due to the hybrid systems characteristic of its dynamics. such a challenge arises from the buck converter operation which depends upon the on/off logical transitions of its electronic switch component to correspondingly activate different continuous vector fields of the converter’s temporal dynamics. this paper presents a sum of squares (sos) polynomial optimization approach for stability analysis of a hybrid model of buck converter which explicitly takes into account the converter’s electronic switching behavior. the proposed method first transforms the converter’s hybrid dynamics model into an equivalent polynomial differential algebraic equation (dae) model. an sos programming algorithm is then proposed to computationally prove the stability of the obtained dae model using lyapunov’s stability concept. based on simulation results, it was found that the proposed method requires only 8.5 seconds for proving the stability of a buck converter model. in contrast, exhaustive simulations based on numerical integration scheme require 15.6 seconds to evaluate the stability of the same model. these results thus show the effectiveness of the proposed method as it can prove the converter stability in shorter computational times without requiring exhaustive simulations using numerical integration. (author) keywords: dc-dc buck converter; switched hybrid systems; lyapunov method; dissipation inequality; sos programming. elysa nensy irawan a, b, nuur wachid abdul majid c, liptia venica a, fahrur aslami d, goro fujita e (a department of mechatronics and artificial intelligence, universitas pendidikan indonesia, indonesia; b functional control system, shibaura institute of technology, japan; c department of system and information technology education, universitas pendidikan indonesia, indonesia; d department of computer engineering, universitas wiralodra, indonesia; e department of electrical engineering, shibaura institute of technology, japan) analyzing the growth and trends of vertical axis wind turbine research: insight from a bibliometric study journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 55-61, 4 ill, 1 tab, 39 ref. bibliometric analysis research has been done for vertical axis wind turbine (vawt). this study aims to determine the growth of vawt research, the number of vawt studies in various countries and the most influential authors to find opportunities for research collaboration, and the challenges of future vawt research. research data was taken from scopus in 1801 articles from 1970-2021. the software used for data interpretation was vosviewer 1.6.19 and tableau public 2022.2. based on the analysis, vawt research has tended to increase from 1970-2021, although there was a decrease from 1987-2006. the country that has conducted the most vawt research is china, while the author with the highest number of citations is from italy. the most dominant research topic related to vawt research is computational fluid dynamics (cfd), which is 50.14 % of the total. a future challenge related to vawt research is finding a suitable turbulence model for each type of vawt or finding an airfoil optimization method so that a model with better performance is obtained. opportunities for research collaboration can be carried out with china or an author with the highest number of citations who has expertise in the field of cfd. (author) keywords: bibliometric analysis; tableau public 2022.2 software; vertical axis wind turbine (vawt); vosviewer 1.6.19 software. riki khomarudin, kevin marojahan banjar-nahor, nanang hariyanto (school of electrical engineering & informatics, bandung institute of technology, indonesia) quasi-dynamic hosting capacity in radial distribution feeder journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 62-71, 16 ill, 4 tab, 21 ref. the target of massive installation of renewable energy is the focus of this research. several industrial sectors continue to install photovoltaic rooftop to support green energy. one of the main objectives of this research is to see the maximum impact of installing a photovoltaic rooftop at journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi 1 point of customer and spread capacity for each customer. this research uses a radial distribution network system that closely resembles the distribution network in indonesia, where the load profile considers the load characteristics of industrial, commercial, and residential loads. this study uses the line equation theorem method to calculate the voltage rises by considering two current measurement points: the current at the end and the current at the base. the obtained voltage rise is then accumulated to be summed up with the customer afterward. the results are obtained by considering three scenarios: 1) voltage limits, 2) voltage limits and line loading, and 3) voltage limits, thermal, and harmonics in accordance with regulations. the obtained results are closely aligned with the simulations performed on the hosting capacity software such as digsilent. (author) keywords: photovoltaic rooftop; line equation theorem; hosting capacity. muhammad zakiyullah romdlony a, rashad abul khayr a, aam muharam b, eka rakhman priandana c, sudarmono sasmono a, muhammad ridho rosa a, e, irwan purnama a, d, amin b, ridlho khoirul fachri a (a school of electrical engineering, telkom university, indonesia; b research center for transportation technology, national research and innovation agency (brin), indonesia; c research center for energy conversion and conservation, national research and innovation agency (brin), indonesia; d research center for smart mechatronics, national research and innovation agency (brin), indonesia; e faculty of science and engineering, university of groningen, netherlands) lstm-based forecasting on electric vehicles battery swapping demand: addressing infrastructure challenge in indonesia journal of mechatronics, electrical power, and vehicular technology, 20223, vol. 14, no. 1, p. 72-79, 8 ill, 1 tab, 22 ref. this article aims to design a model for forecasting the number of vehicles arriving at the battery swap station (bss). in our case, we study the relevance of the proposed approach given the rapid increase in electric vehicle users in indonesia. due to the vehicle electrification program from the government of indonesia and the lack of supporting infrastructure, forecasting battery swap demands is very important for charging schedules. forecasting the number of vehicles is done using machine learning with the long short-term memory (lstm) method. the method is used to predict sequential data because of its ability to review previous data in addition to the current input. the result of the forecasting using the lstm method yields a prediction score using the root-mean-square error (rmse) of 2.3079 × 10−6. the forecasted data can be combined with the battery charging model to acquire predicted hourly battery availability that can be processed further for optimization and scheduling. (author) keywords: battery swap station (bss); demand forecasting; long short-term memory (lstm). arman jaya a, irianto a, afif aulia rahman a, kyungmin sung b (a departement of electrical engineering, electronic engineering polytechnic institute of surabaya, indonesia; b national institute of technology, ibaraki college, japan) design and implementation of capacitor array as dc converters for electrical lighting in limited area journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 80-86, 7 ill, 2 tab, 20 ref. the widely used dc-dc converters are inductor-based dcdc converters and inductors along with combustion. the use of inductors can lead to large power losses, as well as heavy components in real terms. the proposed converter warning array aims to increase the voltage with a large increase ratio through a switching configuration process. this switching method is very simple and uses two pulses that are opposite each other so that the array converter can work optimally, whose function is to adjust the arrangement in a parallel arrangement to a series arrangement. the advantage of using a device is that it makes dc-based dc conversion lightweight and easy to implement. tests have been carried out on 5 hanger arrays with a power of 80 w and 65 w, and the data from the test results show that the voltage increase ratio reaches 81.5 % or 4.08 times the input voltage, which indicates that the array converter warning is able to increase the input voltage according to the number of the arrays. (author) keywords: inductor-based converter; inductor and capacitor-based converter; capacitor array. kurnia fajar adhi sukra a, heru priyanto a, dedy indriatmono b, muhamad agus wijayanto c, irfan yahya ikhsanudin c, yoga akbar ermansyah d (a research center for transportation technology, national research and innovation agency (brin), indonesia; b research center for energy conversion and conservation, national research and innovation agency (brin), indonesia; c directorate of laboratory management, national research and innovation agency (brin), indonesia; d faculty of transportation engineering and vehicle engineering, budapest university of technology and economics, hungary) impact of road load parameters on vehicle co2 emissions and fuel economy: a case study in indonesia journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 87-93, 5 ill, 1 tab, 21 ref. carbon dioxide (co2) contributes to the greenhouse effect and global warming. the indonesian government has introduced a reduction in vehicle taxes based on the number of co2 emissions, meaning that lower co2 emissions result in lower tax rates. to measure the co2 emissions, vehicle testing can be conducted on a chassis dynamometer using road load (r/l) parameters to assess the vehicle's loading during the test. the united nations economic commission for europe (un ece) regulation no. 101 (r101) provides predefined table values for testing, but vehicle manufacturers can also provide their own r/l values, known as actual r/l. in this study, the vehicle underwent two tests: one using the r/l values from the standard table r101 and another using the actual r/l values provided by the manufacturer through coast-down results. by employing the actual r/l values, co2 emissions can be reduced by up to 7.3 %. this reduction is achieved by lowering the vehicle's load by up to 17 % to enable optimal vehicle performance. additionally, there is a potential improvement in fuel economy of up to 7.9 % for vehicles. these findings can serve as a reference for establishing future standard testing procedures. (author) keywords: road load (r/l); un ece r101; carbon dioxide emission; fuel economy. rizky cahya kirana a, nicco avinta purwanto b, nadana ayzah azis b, endra joelianto c, e, sigit puji santosa d, e, bentang arief budiman, d, e, le hoa nguyen f, arjon turnip g (a instrumentation and control graduate program, institut journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii teknologi bandung, indonesia; b faculty of industrial technology, institut teknologi bandung, indonesia; c instrumentation and control research group, institut teknologi bandung, indonesia; d faculty of mechanical and aerospace engineering, institut teknologi bandung, indonesia; e national center for sustainable transportation technology, institut teknologi bandung, indonesia; f faculty of advanced science and technology, university of science and technology, the university of danang, vietnam; g electrical engineering study program, universitas padjajaran, indonesia) failure assessment in lithium-ion battery packs in electric vehicles using the failure modes and effects analysis (fmea) approach journal of mechatronics, electrical power, and vehicular technology, 2023, vol. 14, no. 1, p. 94-104, 5 ill, 6 tab, 60 ref. the use of batteries in electric cars comes with inherent risks. as the crucial component of these vehicles, batteries must possess a highly dependable safety system to ensure the safety of users. to establish such a reliable safety system, a comprehensive analysis of potential battery failures is carried out. this research examines various failure modes and their effects, investigates the causes behind them, and quantifies the associated risks. the failure modes and effect analysis (fmea) method is employed to classify these failures based on priority numbers. by studying 28 accident reports involving electric vehicles, data is collected to identify potential failure modes and evaluate their risks. the results obtained from the fmea assessment are used to propose safety measures, considering the importance of the potential failure modes as indicated by their risk priority number (rpn). the design incorporates safeguards against mechanical stress, external short circuits, and thermal runaway incidents. the findings of this study enhance our understanding of electric vehicle (ev) battery safety and offer valuable insights to ev manufacturers, regulators, and policymakers, aiding them in the development of safer and more reliable electric vehicles. (author) keywords: failures; safety assessment; failure mode and effect analysis; lithium-ion battery; safety system. foreword from editor-in-chief list of contents autoregressive integrated adaptive neural networks classifier for eeg-p300 signal classification mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 mechatronics, electrical power, and vehicular technology e-issn:2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.1-8 autoregressive integrated adaptive neural networks classifier for eeg-p300 signal classification demi soetraprawata*, arjon turnip technical implementation unit for instrumentation development division – lipi kompleks lipi gd. 30, jalan sangkuriang bandung, 40135, indonesia received 09 october 2012; received in revised form 22 february 2013; accepted 27 february 2013 published online 30 july 2013 abstract brain computer interface has a potency to be applied in mechatronics apparatus and vehicles in the future. compared to the other techniques, eeg is the most preferred for bci designs. in this paper, a new adaptive neural network classifier of different mental activities from eeg-based p300 signals is proposed. to overcome the over-training that is caused by noisy and nonstationary data, the eeg signals are filtered and extracted using autoregressive models before passed to the adaptive neural networks classifier. to test the improvement in the eeg classification performance with the proposed method, comparative experiments were conducted using bayesian linear discriminant analysis. the experiment results show that the all subjects achieve a classification accuracy of 100%. keywords: brain computer interface, feature extraction, classification accuracy, autoregressive, adaptive neural networks, eegbased p300, transfer rate. i. introduction a brain computer interface (bci) is a device that allows users to communicate with the world without utilizing voluntary muscle activity. bci systems utilize what is known about brain signals to detect the message that a user chose to communicate. these systems rely on the finding that the brain reacts differently to different stimuli, based on the level of attention that is given to the stimulus and the specific processing that is triggered by the stimulus. therefore brain activity must be monitored with various techniques. among these techniques, eeg is the most preferred for bci designs, because of its non-invasive, cost effectiveness, easy implementation, and best temporal resolution [1, 2]. eegs are usually analyzed in two ways: (i) as free running eeg; (ii) as events related potentials (erps) (i.e., p300, slow cortical potentials (scps), readiness potentials (rps), and steady state visual evoked potentials (ssveps)) [3]. around 1964, chapman and bragdon as well as sutton et al., are independently discovered a wave peaking at approximately 300 ms after taskrelevant stimuli [4]. this component is known as the p300. while the p300 is evoked by many types of paradigms, the most common factors that influence it are stimulus frequency and task relevance [5]. the presence, magnitude, topography and time of the response signalsare often used as metrics of cognitive function in decision making processes. the p300 has been shown to be fairly stable in locked-in patients, reappearing even after severe brain’s stem injuries. farwell and donchin (1988) first showed that this signal may be successfully used in a bci [6]. using a broad cognitive signal like the p300 has the benefit of enabling control through a variety of modalities, as the p300 enables discrete control in response to both auditory and visual stimuli. as it is a cognitive component, the p300 has been known to change in response to subject’s fatigue [5]. one of the most important task in designing a bci is in extracting relevant features from the eeg signals, which is naturally noisy and stochastic. in order to avoid the averaging processes and to remove the artifacts, which are computational complexity, poor generalization, and needs a large number of trainings to achieve a desired accuracy and a communication rate, * corresponding author. tel: +62-22-2503053 e-mail: {demi001, arjo001}@ lipi.go.id http://dx.doi.org/10.14203/j.mev.2013.v4.1-8 d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 2 therefore a new adaptive neural network classifier (annc) of different mental activities are proposed. to overcome the over-training caused by noisy and non-stationary data, the features of the eeg-based p300 signals are extracted using autoregressive (ar) method before passed to the proposed classifier algorithm. in order to examine the performance improvements of the proposed classification method, comparative experiments were conducted using bayesian linear discriminant analysis (blda). the contributions of this paper are as follow: a. enhancements and strengthens the eeg signal according to the small amplitude of the eegbased p300 which is naturally noisy and stochastic. b. driving the tracking error converges to a small value around zero while the closed-loop stability is guaranteed. c. the introduction of the ar method and the application of the proposed classifier improve the classification accuracy and the transfer rate of a bci even when the subjects are in a fatigue condition. the structure of the paper is as follows. in section 2, the eeg data set and pre-processing are described. feature extraction and classification using ar method and adaptive neural networks, respectively, are explained in section 3. results and discussions are presented in section 4. conclusions are drawn in section 5. ii. data set and eeg preprocessing in order to examine the performance improvement of the proposed eeg classification method, the eeg based p300 data used in this paper was obtained previously by hoffmann et al. (2008) who used the following procedure [5]. the data have been recorded according to the 1020 standards from the 32 electrode configurations. in this study, however, only the signals from the eight electrodes configuration were used. each recorded signal has a length of 820 samples with a sampling rate of 2,048 hz. a six-choice signal paradigm was tested using a population of five disable and four able bodied subjects. the subjects were asked to count silently the number of times a prescribed image flashed on a screen. four seconds after a warning tone, six different images (a television, a telephone, a lamp, a door, a window, and a radio) were flashed in a random order. each flash of an image lasted for 100 ms, and for the following 300 ms no image was flashed (i.e., the inter-stimulus interval was 400 ms). each subject completed four recording sessions. each of the sessions consisted of six runs with one run for each of the six images. the duration of one run was approximately one minute and the duration of one session, including setup of electrodes and short breaks between runs, was approximately 30 minutes. one session comprised on average 810 trials, and the entire data for one subject was taken from an average of 3,240 trials. our goal is to discriminate all possible combinations of the pairs of mental activities from each other using the corresponding eeg signals. the eeg signals are processed in segments (eeg-trials) in which the bci attempts to recognize the mental activities. before the classification and validation are performed, several pre-processing operations including filtering, and down sampling were applied to the data. a 6th order forwardbackward butterworth band pass filter with cut off frequencies of one hz and 12 hz was used to filter the data. the eeg was down sampled from 2,048 hz to 32 hz by selecting each 64th sample from the band pass-filtered data. iii. feature extraction and classification a. feature extraction in this section, the feature extraction which is focused on the estimation of statistical measurements from the perturbation free eegtrials delivered by the pre-processing module, is explored. the features computed on a given eeg-trial are grouped into a vector called feature vector that is sent to the pattern recognition module which evaluates the likelihoods that the eeg-trial was produced during the execution of the mental activities. the autoregressive (ar) method is built on the hypotheses of stationarity, ergodicity, absence of coupling between the univariate components, and existence of a linear prediction model [7]. let 𝒀𝒀 be an 𝑁𝑁𝑒𝑒 dimensional multivariable stochastic eeg signal of length sn , composed of randomvectors: { 𝒀𝒀(𝑘𝑘) = (𝑦𝑦1 (𝑘𝑘) … 𝑦𝑦𝑁𝑁𝑒𝑒 (𝑘𝑘)) 𝑇𝑇| �𝑘𝑘 = 0, … , 𝑁𝑁𝑠𝑠 − 1 } �where 𝑦𝑦1 , … , 𝑦𝑦𝑁𝑁𝑒𝑒 are the univariate components of 𝒀𝒀 . the ar model can be generated by a linear prediction model of the form [7]: 𝒀𝒀(𝑘𝑘) = −∑ 𝑨𝑨(𝑘𝑘, 𝑖𝑖)𝒀𝒀(𝑘𝑘 − 𝑖𝑖) + 𝑒𝑒1 (𝑘𝑘) 𝑄𝑄 𝑖𝑖=1 , (1) where 𝑄𝑄 is the model order, the 𝑨𝑨(𝑘𝑘, 𝑖𝑖) are 𝑁𝑁𝑒𝑒𝑥𝑥𝑁𝑁𝑠𝑠 matrices (𝑁𝑁𝑒𝑒 ne denoting the number of electrodes and ns denotes the number of temporal samples per eeg channel), and 𝑒𝑒1 (𝑘𝑘) is d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 3 the prediction error with a zero mean random vector. since the coupling between the channels is ignored, equation (1) can be split into linear prediction models corresponding to each univariate component. thus, the n-th univariate component of 𝒀𝒀can be written in the form: 𝑦𝑦𝑛𝑛 (𝑘𝑘) = −∑ 𝑎𝑎𝑛𝑛 (𝑘𝑘, 𝑖𝑖)𝑦𝑦𝑛𝑛 (𝑘𝑘 − 𝑖𝑖) + 𝑒𝑒n (𝑘𝑘) 𝑄𝑄𝑛𝑛 𝑖𝑖=1 , (2) where the 𝑎𝑎𝑛𝑛 (𝑘𝑘, 𝑖𝑖) are the ar coefficients and 𝑄𝑄𝑛𝑛 is the ar order corresponding to 𝑦𝑦𝑛𝑛 , and 𝑒𝑒n is the n-th prediction error process. the indexes n and k are used to reference the electrode and time index, respectively. furthermore, as stationarity and ergodicity are assumed, then the ar model for the n-th channel becomes: 𝑦𝑦𝑛𝑛 (𝑘𝑘) = −∑ 𝑎𝑎𝑛𝑛 (𝑖𝑖)𝑦𝑦𝑛𝑛 (𝑘𝑘 − 𝑖𝑖) + 𝑒𝑒n (𝑘𝑘) 𝑄𝑄𝑛𝑛 𝑖𝑖=1 . (3) the coefficients 𝑎𝑎𝑛𝑛 (1), … , 𝑎𝑎𝑛𝑛 (𝑄𝑄𝑛𝑛 ) can be determined by minimizing the averaged squared prediction error: 𝜀𝜀(𝑄𝑄𝑛𝑛 ) = 1 𝑁𝑁𝑠𝑠 ∑ 𝑒𝑒𝑛𝑛2 (𝑘𝑘) 𝑁𝑁𝑠𝑠−1 𝑘𝑘=0 = 1 𝑁𝑁𝑠𝑠 ∑ �𝑦𝑦𝑛𝑛 (𝑘𝑘) + ∑ 𝑎𝑎𝑛𝑛 (𝑖𝑖)𝑦𝑦(𝑘𝑘 − 𝑖𝑖) 𝑄𝑄𝑛𝑛 𝑖𝑖=1 � 𝟐𝟐𝑁𝑁𝑠𝑠−1 𝑘𝑘=0 (4) in this relation, the samples prior to 𝑦𝑦𝑛𝑛 (0) are assumed to be zero. b. adaptive neural networks classifier artificial neural networks have been proposed in the fields of information and neural sciences following research into the mechanisms and structures of the brain. this has led to the development of new computational models for solving complex problems such as pattern recognition, rapid information processing, learning and adaptation, classification, identification and modelling, speech, vision and control systems [8-14]. in this paper, we are only concerned with the adaptive classifier problem of eeg-based p300 represented by nonlinear discrete-time systems which can be transformed in state space description [15] as follow: 𝑥𝑥1 (𝑘𝑘 + 1) = 𝑥𝑥2 (𝑘𝑘), 𝑥𝑥2 (𝑘𝑘 + 1) = 𝑥𝑥3 (𝑘𝑘), ⋮ 𝑥𝑥𝑛𝑛 (𝑘𝑘 + 1) = 𝑓𝑓(𝑥𝑥(𝑘𝑘)) + 𝑔𝑔�𝑥𝑥(𝑘𝑘)�𝑢𝑢(𝑘𝑘), 𝑦𝑦𝑘𝑘 = 𝑥𝑥1 (𝑘𝑘), (5) where 𝑥𝑥(𝑘𝑘) = [𝑥𝑥1 (𝑘𝑘), 𝑥𝑥2 (𝑘𝑘), … , 𝑥𝑥𝑛𝑛 (𝑘𝑘)]𝑇𝑇 ∈ 𝑅𝑅𝑛𝑛 , 𝑢𝑢(𝑘𝑘) ∈ 𝑅𝑅 , 𝑦𝑦(𝑘𝑘) ∈ 𝑅𝑅 are the state variables, system input and output, respectively; 𝑓𝑓(𝑥𝑥(𝑘𝑘)) and 𝑔𝑔�𝑥𝑥(𝑘𝑘)� are unknown which may not be linearly parameterized. the classifier system attempts to make the plant output 𝑦𝑦𝑑𝑑 (𝑘𝑘)match the target output asymptotically, so that lim𝑡𝑡→∞‖𝑦𝑦𝑑𝑑 (𝑘𝑘) − 𝑦𝑦𝑘𝑘‖ ≤ 𝜀𝜀 for some specified constant 𝜀𝜀 ≥ 0 . if 𝑓𝑓(𝑥𝑥(𝑘𝑘)) and 𝑔𝑔�𝑥𝑥(𝑘𝑘)� are known, the following classifier can be used, and the system would exactly track the target output 𝑦𝑦𝑑𝑑 (𝑘𝑘). 𝑢𝑢(𝑘𝑘) = 𝑔𝑔−1�𝑥𝑥(𝑘𝑘)��𝑦𝑦𝑑𝑑 (𝑘𝑘) − 𝑓𝑓(𝑥𝑥(𝑘𝑘))� (6) since 𝑓𝑓(𝑥𝑥(𝑘𝑘)) and 𝑔𝑔�𝑥𝑥(𝑘𝑘)� are unknown, neural networks can be used to learn to approximate these functions and generate suitable classifiers. although the function 𝑔𝑔�𝑥𝑥(𝑘𝑘)� is not known, it can be assumed that its sign is known along system trajectories and that there exist two constants 𝑔𝑔0 , 𝑔𝑔1 > 0 such that 𝑔𝑔0 ≤ �𝑔𝑔�𝑥𝑥(𝑘𝑘)�� ≤ 𝑔𝑔1 , ∀𝑥𝑥 ∈ ω ∈ 𝑅𝑅𝑛𝑛 with compact subset ω containing the origin. this assumption implies that the function 𝑔𝑔�𝑥𝑥(𝑘𝑘)� is strictly either positive or negative. from this point forward therefore, without losing generality, we shall assume 𝑔𝑔�𝑥𝑥(𝑘𝑘)� > 0. neural networks are general modelling tools that can approximate any continuous or discrete nonlinear function to any desired accuracy over a compact set [9-11, 16, 17]. in this work, a new adaptive neural network classifier is developed for nonlinear system (5) using high order neural networks. therefore the mental activities according to the given stimuli could be extracted and classified with high accuracy. it should be noted that although the new states 𝑥𝑥2 , 𝑥𝑥3 , . . . , 𝑥𝑥𝑛𝑛 are not available in practice, we can predict them as will be detailed in the following discussion. let 𝑥𝑥𝑑𝑑 = [𝑦𝑦𝑑𝑑 (𝑘𝑘), 𝑦𝑦𝑑𝑑 (𝑘𝑘 + 1), … , 𝑦𝑦𝑑𝑑 (𝑘𝑘 + 𝑛𝑛 − 1)]𝑇𝑇 the target system states. define error 𝑒𝑒(𝑘𝑘) = 𝑥𝑥(𝑘𝑘) − 𝑥𝑥𝑑𝑑 (𝑘𝑘). the equation of 𝑒𝑒(𝑘𝑘) can be written as: 𝑒𝑒1 (𝑘𝑘 + 1) = 𝑒𝑒2 (𝑘𝑘), 𝑒𝑒2 (𝑘𝑘 + 1) = 𝑒𝑒3 (𝑘𝑘), ⋮ 𝑒𝑒𝑛𝑛 (𝑘𝑘 + 1) = 𝑓𝑓�𝑥𝑥(𝑘𝑘)� + 𝑔𝑔�𝑥𝑥(𝑘𝑘)�𝑢𝑢(𝑘𝑘) −𝑦𝑦𝑑𝑑 (𝑘𝑘 + 𝑛𝑛). (7) in order to develop the output feedback classifier clearly, define the following new variables 𝑦𝑦�(𝑘𝑘) = [𝑦𝑦𝑘𝑘−𝑛𝑛+1 , … , 𝑦𝑦𝑘𝑘−1 , 𝑦𝑦𝑘𝑘 ]𝑇𝑇, 𝑢𝑢�𝑘𝑘−1 (𝑘𝑘) = [𝑢𝑢𝑘𝑘−1 , … , 𝑢𝑢𝑘𝑘−𝑛𝑛+1 ]𝑇𝑇 , and 𝑧𝑧̅(𝑘𝑘) = �𝑦𝑦�𝑇𝑇(𝑘𝑘), 𝑢𝑢�𝑘𝑘−1 𝑇𝑇 (𝑘𝑘) � 𝑇𝑇 ∈ ω𝑧𝑧̅ ⊂𝑅𝑅2𝑛𝑛−1 . according to the definition of the new states, 𝑦𝑦�(𝑘𝑘) = d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 4 [𝑥𝑥1 (𝑘𝑘 − 𝑛𝑛 + 1), … , 𝑥𝑥1 (𝑘𝑘 − 1), 𝑥𝑥1 (𝑘𝑘)]𝑇𝑇 and from eq. (5), the following equation is obtained. 𝑦𝑦𝑘𝑘+1 = 𝑥𝑥2 (𝑘𝑘) = 𝑥𝑥3 (𝑘𝑘 − 1) = ⋯ = 𝑥𝑥𝑛𝑛 (𝑘𝑘 − 𝑛𝑛 + 2) = 𝑓𝑓�𝑦𝑦�(𝑘𝑘)� + 𝑔𝑔�𝑦𝑦�(𝑘𝑘)�𝑢𝑢𝑘𝑘−𝑛𝑛+1 = 𝜙𝜙2�𝑧𝑧̅(𝑘𝑘)�, (8) which𝑥𝑥2 (𝑘𝑘) is a function of 𝑦𝑦(𝑘𝑘) and 𝑢𝑢𝑘𝑘−𝑛𝑛+1 . from (5), similarly the following equation is obtained. 𝑦𝑦𝑘𝑘+2 = 𝑓𝑓�𝑦𝑦�(𝑘𝑘 + 1)� + 𝑔𝑔�𝑦𝑦�(𝑘𝑘 + 1)�𝑢𝑢𝑘𝑘−𝑛𝑛+2 = 𝜙𝜙3��̅�𝑧(𝑘𝑘)�, ⋮ 𝑦𝑦𝑘𝑘+𝑛𝑛−1 = 𝑓𝑓�𝑦𝑦�(𝑘𝑘 + 𝑛𝑛 − 2)� + 𝑔𝑔�𝑦𝑦�(𝑘𝑘 + 𝑛𝑛 − 2)�𝑢𝑢𝑘𝑘−1 = 𝜙𝜙𝑛𝑛�𝑧𝑧̅(𝑘𝑘)� (9) it proves that 𝑥𝑥𝑛𝑛 (𝑘𝑘) is a function of 𝑧𝑧̅(𝑘𝑘) . substituting the predicted states into the last equation in (5), we obtain: 𝑦𝑦𝑘𝑘+𝑛𝑛 = 𝑥𝑥𝑛𝑛 (𝑘𝑘 + 1) = 𝑓𝑓�𝑧𝑧̅(𝑘𝑘)� + 𝑔𝑔�𝑧𝑧̅(𝑘𝑘)�𝑢𝑢(𝑘𝑘) (10) where 𝑓𝑓�𝑧𝑧�(𝑘𝑘)� = 𝑓𝑓��𝑥𝑥1(𝑘𝑘),𝜙𝜙2�𝑧𝑧�(𝑘𝑘)�, … , 𝜙𝜙𝑛𝑛�𝑧𝑧�(𝑘𝑘)�� 𝑇𝑇 �, (11) 𝑔𝑔�𝑧𝑧�(𝑘𝑘)� = 𝑔𝑔��𝑥𝑥1(𝑘𝑘), 𝜙𝜙2�𝑧𝑧�(𝑘𝑘)�, … , 𝜙𝜙𝑛𝑛�𝑧𝑧�(𝑘𝑘)�� 𝑇𝑇 �. (12) define a tracking error as 𝑒𝑒𝑦𝑦 (𝑘𝑘) = 𝑦𝑦𝑘𝑘 − 𝑦𝑦𝑑𝑑 (𝑘𝑘). the tracking error dynamics are given by: 𝑒𝑒𝑘𝑘 (k + n) = −𝑦𝑦𝑑𝑑 (𝑘𝑘 + 𝑛𝑛) + 𝑓𝑓�𝑧𝑧̅(𝑘𝑘)� +𝑔𝑔�𝑧𝑧̅(𝑘𝑘)�𝑢𝑢(𝑘𝑘). (13) supposing that the nonlinear functions 𝑓𝑓�𝑧𝑧̅(𝑘𝑘)� and 𝑔𝑔�𝑧𝑧̅(𝑘𝑘)�are known exactly, then a desired classifier, such that the output 𝑦𝑦𝑘𝑘 follows the target trajectory 𝑦𝑦𝑑𝑑 (𝑘𝑘), is written as follow: 𝑢𝑢∗(𝑘𝑘) = − 1 𝑔𝑔�𝑧𝑧̅(𝑘𝑘)� �𝑓𝑓��̅�𝑧(𝑘𝑘)�� − 𝑦𝑦𝑑𝑑 (𝑘𝑘 + 𝑛𝑛). (14) substituting the desired classifier equation (14) into error dynamics equation (13), i.e., 𝑢𝑢(𝑘𝑘) = 𝑢𝑢∗(𝑘𝑘), then the error dynamics goes to zero is obtained. this means that after n steps, we have 𝑒𝑒𝑦𝑦 (𝑘𝑘) = 0 . therefore, 𝑢𝑢∗(𝑘𝑘) is a n-step dead-beat classifier. moreover, the desired classifier 𝑢𝑢∗(𝑘𝑘) can be expressed as: 𝑢𝑢∗(𝑘𝑘) = 𝑢𝑢�∗�𝑧𝑧̅(𝑘𝑘)�, (15) where 𝑧𝑧̅(𝑘𝑘) = [𝑧𝑧̅𝑇𝑇(𝑘𝑘), 𝑦𝑦𝑑𝑑 (𝑘𝑘 + 𝑛𝑛)]𝑇𝑇 ∈ ω𝑧𝑧̅ ⊂ 𝑅𝑅2𝑛𝑛 with component set zω is defined as ω𝑧𝑧̅ = ��(𝑦𝑦�(𝑘𝑘), 𝑢𝑢𝑘𝑘−1 (𝑘𝑘), 𝑦𝑦𝑑𝑑 )|𝑢𝑢�𝑘𝑘−1 (𝑘𝑘) ∈ ω𝑢𝑢,𝑦𝑦𝑘𝑘,𝑦𝑦𝑑𝑑∈ω𝑦𝑦. (16) when the nonlinear functions 𝑓𝑓�𝑧𝑧̅(𝑘𝑘)� and 𝑔𝑔�𝑧𝑧̅(𝑘𝑘)� are unknown, the nonlinearity 𝑢𝑢∗(𝑘𝑘) is not available. in the following, high order neural networks (honns) is introduced to construct the unknown nonlinear functions 𝑓𝑓�𝑧𝑧̅(𝑘𝑘)� and 𝑔𝑔�𝑧𝑧̅(𝑘𝑘)� for approximating the desired feedback signal 𝑢𝑢∗(𝑘𝑘) . under certain conditions, it has been proven that neural networks has function approximation abilities and has been frequently used as function approximators, which include linearly and nonlinearly parameterized networks. consider the following honns [16, 18]: 𝜑𝜑(𝑊𝑊, 𝑧𝑧) = 𝑊𝑊𝑇𝑇𝑆𝑆(𝑧𝑧), 𝑊𝑊and 𝑆𝑆(𝑧𝑧) ∈ 𝑅𝑅𝑙𝑙 , (17) 𝑆𝑆(𝑧𝑧) = [𝑠𝑠1 (𝑧𝑧), 𝑠𝑠2 (𝑧𝑧), … , 𝑠𝑠𝑙𝑙(𝑧𝑧)]𝑇𝑇, (18) 𝑠𝑠𝑖𝑖(𝑧𝑧) = ∏ �𝑠𝑠(𝑧𝑧𝑗𝑗 )� 𝑑𝑑𝑗𝑗 (𝑖𝑖) 𝑗𝑗∈𝑙𝑙𝑖𝑖 , 𝑖𝑖 = 1,2, … , 𝑙𝑙 , (19) where 𝑧𝑧 = [𝑧𝑧1 , 𝑧𝑧2 , … , 𝑧𝑧𝑚𝑚 ]𝑇𝑇 ∈ ω𝑧𝑧 ⊂ 𝑅𝑅𝑚𝑚 ; the positive integer 𝑙𝑙 indicates the node number of neural network; 𝑑𝑑𝑗𝑗 (𝑖𝑖) indicates the non-negative integers; 𝑊𝑊 is an adjustable synoptic weight vectors; and 𝑠𝑠(𝑧𝑧𝑗𝑗 ) is chosen as a hyperbolic tangent function. 𝑠𝑠(𝑧𝑧𝑗𝑗 ) = 𝑒𝑒𝑧𝑧𝑗𝑗 − 𝑒𝑒−𝑧𝑧𝑗𝑗 𝑒𝑒𝑧𝑧𝑗𝑗 + 𝑒𝑒−𝑧𝑧𝑗𝑗 (20) according to girosi and poggio (1989) [19], there exist ideal weight 𝑊𝑊∗such that the function 𝜑𝜑(𝑧𝑧) can be approximated by an ideal neural network on a compact set ω𝑧𝑧 ⊂ 𝑅𝑅𝑚𝑚 : 𝜑𝜑(𝑧𝑧) = 𝑊𝑊∗𝑇𝑇𝑆𝑆(𝑧𝑧) + 𝜀𝜀𝑧𝑧, (21) where 𝜀𝜀𝑧𝑧 is called the neural network approximation error. it is representing the minimum possible deviation of the ideal approximator 𝑊𝑊∗𝑇𝑇𝑆𝑆(𝑧𝑧) from the unknown function 𝜑𝜑(𝑧𝑧). in general, the ideal neural network weight 𝑊𝑊∗ is not known and needs to be estimated. in this paper, there exist an integer 𝑙𝑙∗ and an ideal constant weight vector 𝑊𝑊∗, such that for all 𝑙𝑙 ≥ 𝑙𝑙∗, 𝑢𝑢�∗(𝑧𝑧̅(𝑘𝑘)) = 𝑊𝑊∗𝑇𝑇𝑆𝑆(𝑧𝑧̅(𝑘𝑘)) + 𝜀𝜀𝑧𝑧̅, ∀𝑧𝑧̅ ∈ ω𝑧𝑧̅, (22) where 𝜀𝜀𝑧𝑧̅ is the neural network estimation error satisfying |𝜀𝜀𝑧𝑧̅| < 𝜀𝜀0 . based on lyapunov technique, it has been proven in ge et al., 2003 [17] that the adaptive classifier law and the updating law can be chosen as: d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 5 𝑢𝑢(𝑘𝑘) = 𝑊𝑊� 𝑇𝑇𝑆𝑆(𝑧𝑧̅(𝑘𝑘)), (23) 𝑊𝑊� (𝑘𝑘 + 1) = 𝑊𝑊� (𝑘𝑘1 ) + γ[𝑆𝑆�𝑧𝑧̅(𝑘𝑘1 )�(𝑦𝑦𝑘𝑘+1 −𝑦𝑦𝑑𝑑 (𝑘𝑘 + 1)) + 𝜌𝜌𝑊𝑊� (𝑘𝑘)], (24) where 𝑘𝑘1 = 𝑘𝑘 − 𝑛𝑛 + 1 , diagonal gain matrix γ > 0, and 𝜌𝜌 > 0. therefore, the tracking error converges to a small neighborhood of zero by increasing the approximation accuracy of the neural networks and the closed-loop stability is guaranteed. figure 1 shows the structure of the preprocessing, feature extraction, and the annc algorithm. in figure 1, )(tx indicates a non-pre processed (raw) eeg signal; )(kx indicates a filtered signal; )(ky indicates an extracted signals in which the artifact was removed; )(kyd and ky indicate a target and classified signal, respectively. iv. result and discussion in this study, a new method using adaptive neural networks for the classification of the eegbased p300 signals is proposed. this method is supported by the ar model to extract the features and reduce the artifact that is contained within the eeg signals. the methods mentioned above were applied to the training of eight subjects who participated in four training sessions with six runs for each session. figure 2 and 3 are the preprocessed eeg-based p300 signals using butterworth band pass filter and after applying the ar method as feature extractor and artifacts remover, respectively. although we can notice some improvement, at figure 3, it is still difficult to classify the signals with respect to the p300 component. thus, a new adaptive neural networks classifier is proposed. the tracking error graph with and without applying the ar model approach is shown in figure 4. the curves show that a level of accuracy is attained after about 250 iterations by applying the ar model approach. on the other hand, the same level of accuracy is attained after 1,800 iterations if the proposed feature extraction method is not applied. it means the introduction of the ar method is relevant to accelerate the training processes. the tracking error converges to a small value around zero while the closed-loop stability is guaranteed. furthermore, the tracking error with the ar model was converging in faster. according to [17], the data set for subject five were not included in the simulation since the subject misunderstood the instructions given before the experiment. comparative plots of the figure 1. structure of feature extraction and classification algorithms figure 2. pre-processed eeg signals using the butterworth band pass filter figure 3. extracted eeg signals using the ar model figure 4. network’s performance according tomean squares errors d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 6 classification accuracies and transfer rates (obtained with blda, annc, and the combination of the ar model and annc methods and averaged over four sessions) for the disable-bodied subjects (subjects 1 – 4) and ablebodied subjects (subjects 6 – 9) are shown in figure 5 and 6, respectively. all of the subjects (with the combination of the ar model and annc methods), except for subjects 6 and 9, achieved an average classification accuracy of 100% after five blocks of stimulus presentations were averaged (i.e., 14 second). however, subjects 6 and 9, compared with blda, still achieved an average classification accuracy of 100% after nine and ten figure 5. comparison of classification accuracy and transfer rate plots obtained with blda, annc, and the combination of the ar model and annc for disable-bodied subjects figure 6. comparison of classification accuracy and transfer rate plots obtained with blda, annc, and the combination of the ar model and annc for able-bodied subjects 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) 0 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 50 subject 1 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 2 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) blda annc ar+annc subject 4 accuracy transfer rate 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) time (s) 0 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 50 subject 3 time [s] time [s] a cc ur ac y (% ) time [s] subject 3 subject 4 time [s] transfer rate accuracy subject 1 subject 2 ac cu ra cy (% ) tr a n s f er r a t e (b it s / m in ) tr a n sf er r at e (b its /m in ) 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) 0 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 50 subject 6 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 7 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) time (s) 0 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 500 5 10 15 20 25 30 35 40 45 50 subject 8 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) blda annc ar+annc subject 9 accuracy transfer rateac cu ra cy (% ) time [s] time [s] subject 6 a cc ur ac y (% ) tr an sf er r at e (b its /m in ) subject 9 transfer rate accuracy subject 7 tr an sf er r at e (b its /m in ) subject 8 d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 7 blocks of stimulus presentations were averaged, respectively. this results give a significant improvement compared with the results presented in [17] in which subject 6 and subject 9 were not achieved an average classification accuracy of 100%. it means the introduction of the ar method and the application of the proposed classifier enables the bci to extract and classify the information in terms of the classification accuracy from a fatigue subject. thus, fatigue as one of the reasons for the poorer performance of subject 9, as mentioned in hoffmann et al. [5], can be solved using the proposed method. v. conclusions the results presented in this study show that corresponding to the classification accuracy, the data indicates that a p300-based bci system can communicates at the rate of 31.2 bits/min and 36.7 bits/min for the disable-bodied and ablebodied subjects, respectively. the classification and transfer rate accuracies obtained based annc with the ar models approach are found to be far superior in comparison with the blda approach and therefore better suited for bci applications. acknowledgement this work is a part of thematics project research funded by upt bpi lipi (dipa no. 3425.01.011) budgetting year of 2012. the authors would like to thank the deputy chairmant for scientific services dr. fatimah zulfah s. padmadinata for supporting to publish this paper. reference [1] b. e. hillner, et al., "impact of positron emission tomography/computed tomography and positron emission tomography (pet) alone on expected management of patients with cancer: initial results from the national oncologic pet registry," j clin oncol, vol. 26, pp. 2155-61, may 1 2008. [2] f. jouret, et al., "single photon emissioncomputed tomography (spect) for functional investigation of the proximal tubule in conscious mice," am j physiol renal physiol, vol. 298, pp. f454-60, feb 2010. [3] e. niedermeyer and f. l. d. silva, electroencephalography, 4th ed. baltimore: lippincott, williams & wilkins, 1999. [4] r. m. chapman and h. r. bragdon, "evoked responses to numerical and non-numerical visual stimuli while problem solving," nature, vol. 203, pp. 1155-1157, 1964. [5] u. hoffmann, et al., "an efficient p300based brain–computer interface for disabled subjects," journal of neuroscience methods, vol. 167, pp. 115-125, 2008. [6] l. a. farwell and e. donchin, "talking off the top of your head: toward a mental prosthesis utilizing event-related brain potentials," electroencephalogr clin neurophysiol, vol. 70, pp. 510-23, dec 1988. [7] w. d. penny, et al., "eeg-based communication: a pattern recognition approach," ieee trans rehabil eng, vol. 8, pp. 214-5, jun 2000. [8] h. chen and l. li, "semisupervised multicategory classification with imperfect model," ieee trans neural netw, vol. 20, pp. 1594-603, oct 2009. [9] s. s. ge, et al., "nonlinear adaptive control using neural networks and its application to cstr systems," journal of process control, vol. 9, pp. 313-323, 1999. [10] s. s. ge, et al., "adaptive mnn control for a class of non-affine narmax systems with disturbances," systems & control letters, vol. 53, pp. 1-12, 2004. [11] s.-j. liu, et al., "adaptive outputfeedback control for a class of uncertain stochastic non-linear systems with time delays," international journal of control, vol. 81, pp. 1210-1220, august 1 2008. [12] s. jaiyen, et al., "a very fast neural learning for classification using only new incoming datum," ieee trans neural netw, vol. 21, pp. 381-92, mar 2010. [13] s. ozawa, et al., "a multitask learning model for online pattern recognition," ieee trans neural netw, vol. 20, pp. 430-45, mar 2009. [14] y. washizawa, "feature extraction using constrained approximation and suppression," ieee trans neural netw, vol. 21, pp. 201-10, feb 2010. [15] a. isidori, nonlinear control systems, 2nd ed. berlin: springer-verlag, 1989. [16] s. s. ge, et al., stable adaptive neural network control, 1st ed. norwell: kluwer academic, 2001. [17] s. s. ge, et al., "adaptive nn control for a class of strict-feedback discrete-time d. soetraprawata and a. turnip / mechatronics, electrical power, and vehicular technology 04 (2013) 1-8 8 nonlinear systems," automatica, vol. 39, pp. 807-819, 2003. [18] e. b. kosmatopoulos, et al., "high-order neural network structures for identification of dynamical systems," ieee trans neural netw, vol. 6, pp. 42231, march 1995. [19] f. girosi and t. poggio, "networks and the best approximation property," biological cybernetics, vol. 63, pp. 169176, july 1 1990. feature extraction adaptive neural networks classifier mev mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.111-116 vibration disturbance damping system design to protect payload of the rocket perancangan sistem peredam gangguan getaran untuk melindungi beban-guna roket sutisno a, *, andreas prasetya adi a a bidang kendali dan telemetri, pusat teknologi roket, lapan jl. mekarsari 2, rumpin, bogor 16350 received 30 sept 2012; received in revised form 1 december 2012; accepted 04 december 2012 published online 18 december 2012 abstract rocket motor generates vibrations acting on whole rocket body including its contents. part of the body which is sensitive to disturbance is the rocket payload. the payload consists of various electronic instruments including: transmitter, various sensors, accelerometer, gyro, the embedded controller system, and others. this paper presents research on rocket vibration influence to the payload and the method to avoid disturbance. avoiding influence of vibration disturbance can be done using silicone gel material whose typical damping factors are relatively high. the rocket vibration was simulated using electromagnetic motor, and the vibrations were measured using an accelerometer sensor. the measurement results were displayed in the form of curve, indicating the vibration level on some parts of the tested material. some measurement results can be applied to determine the good material to attenuate vibration disturbance on the instruments of the payload. key words: motor, rocket, vibration, payload, silicone. abstrak motor roket dapat menimbulkan getaran yang menggetarkan roket beserta isinya. bagian yang rentan mengalami gangguan adalah beban-guna roket. beban-guna ini terdiri dari berbagai peralatan elektronik seperti: transmitter, macam-macam sensor, akselerometer, gyro, embedded controller system, dan lain sebagainya. pada makalah ini disajikan penelitian pengaruh getaran motor roket terhadap beban-guna dan cara mengatasi gangguan tersebut. untuk mengatasi pengaruh gangguan getaran dapat dilakukan dengan menggunakan bahan silicone gel. silicone gel dipilih sebagai bahan isolator karena memiliki faktor redaman spesifik yang relatif tinggi dibandingkan dengan beberapa bahan lain. getaran motor roket disimulasikan menggunakan motor listrik dan diukur menggunakan sensor akselerometer. hasil pengukuran ditampilkan dalam bentuk kurva, yang menunjukkan level getaran pada beberapa bagian benda uji. hasil dari beberapa percobaan dapat digunakan untuk menentukan bahan peredam yang baik untuk mengurangi getaran yang mengganggu instrumen pada beban-guna. kata kunci: motor, roket, getaran, beban-guna, silicone gel. i. introduction an important part in rocket is the electronic payload named embedded control system which consists of microprocessor, sensors, analog and digital circuits, transceiver radio, circuit wiring and power supply. the entire parts of the payload must be protected from disturbances occurring mainly at the time of launching. the most influencing disturbances are held along propellant burning time, as shown in figure 1. most of the time, very significant shocks and vibrations occurred due to the rocket motor firing. frequently, problem occurs at the launching, causing the electronic parts of the payload not to function suddenly while the motor is still firing. these problems happen frequently in launching of a big type rocket such as rx-250, rx-320 and rx420 [11]. to resolve the problem it is necessary to have an absorption system to reduce vibration and shock disturbances. the absorption system can be used to protect the embedded system from various shocks, vibrations and acceleration forces, not only during burning time but also along the * corresponding author. tel: +62-21-49006215; +62-81389829416 e-mail: rusa9@yahoo.com http://dx.doi.org/10.14203/j.mev.2012.v3.111-116 sutisno and a.p. adi / mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 112 whole rocket trajectory. the objective of this studi is to design vibration disturbance system to protect payload of the rocket. by this design, it is expected that the payload will properly work along whole trajectory, at least during burning time. ii. discussion and theory in rocket launching, disturbances are capable to damage the embedded control system. these disturbances consist of two components i.e. acceleration of vibration and linear acceleration generated in motor thrust. in several lapan (indonesian national institute of aeronautics and space) rockets, linear acceleration achieved is up to 20 g [11]. in line with the fact that the dominant disturbance constitutes vibration the research presented in the paper is mainly focused on the disturbance caused by vibration. a. vibration vibration, which is back and forth moving in a certain time interval, is related to the oscillating move of a body and forces relating to the movement. a body hanged on a spring can be used to generate a vibration. all bodies owning mass and elasticity are capable to vibrate. hence, almost all engineering machines structures experience vibration. vibration is classified into two classes, free vibration and forced vibration. 1) free vibration free vibration occurs if a system is oscillating due to its internal forces. a system which is free vibrating will oscillate in one or several of its natural frequencies. all systems owning mass and elasticity can freely vibrate without external forces. 2) force vibration force vibration is vibration caused by external stimulating force. if the force is oscillating then the system is forced to vibrate on the stimulating frequency. if the stimulating frequency is the same as one of the system natural frequencies, then a resonance will occur. this resonance can be great and dangerous. it can damage to a big structure like aircraft wing, bridge, or building. in force vibration, oscillation can be regular or irregular repeat. if the move is repeated in the same duration then the move is called periodical vibration and the repeating time is called period of the oscillation. in periodical vibration, position as function of time can be expressed as x(t) = x(t+t) where t is period of the oscillation. physical model of the oscillation system is shown in figure 2. mathematical model can be expressed using equation of vertical force balance: 𝑚𝑚𝑝𝑝(𝑡𝑡) + 𝑘𝑘𝑥𝑥(𝑡𝑡) (1) supposing position as function of time is: 𝑥𝑥(𝑡𝑡) = 𝐴𝐴 sin(𝜔𝜔𝑡𝑡) + 𝐵𝐵 cos(𝜔𝜔𝑡𝑡) velocity of the move: 𝑣𝑣(𝑡𝑡) = 𝑑𝑑𝑥𝑥 𝑑𝑑𝑡𝑡 = 𝜔𝜔𝐴𝐴 cos(𝜔𝜔𝑡𝑡) − 𝜔𝜔𝐵𝐵 sin(𝜔𝜔𝑡𝑡) acceleration of the move: 𝑝𝑝(𝑡𝑡) = 𝑑𝑑𝑣𝑣 𝑑𝑑𝑡𝑡 = −𝜔𝜔2𝐴𝐴 sin(𝜔𝜔𝑡𝑡) − 𝜔𝜔2𝐵𝐵 cos(𝜔𝜔𝑡𝑡) 𝑝𝑝(𝑡𝑡) = −𝜔𝜔2𝑥𝑥(𝑡𝑡) (2) then from equation (1) and (2) we obtain: 𝑚𝑚�−𝜔𝜔2𝑥𝑥(𝑡𝑡)� + 𝑘𝑘𝑥𝑥(𝑡𝑡) = 0 (3) (𝑘𝑘 − 𝑚𝑚𝜔𝜔2 )𝑥𝑥(𝑡𝑡) = 0 (4) vibration occurs if 𝑥𝑥(𝑡𝑡) ≠, then (𝑘𝑘 − 𝑚𝑚𝜔𝜔2 ) = 0 and natural frequency can be expressed as: 𝜔𝜔𝑛𝑛 = � 𝑘𝑘 𝑚𝑚 (5) figure 1. rocket launching in burning time. figure 2. physical model of the oscillation system [1]. sutisno and a.p. adi / mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 113 or: 𝑓𝑓𝑛𝑛 = 1 2𝜋𝜋 �𝑘𝑘 𝑚𝑚 (6) where ωn : natural frequency (radian per second) fn : natural frequency (hertz) k : stiffness (newton per meter) m : mass of load (kilogram) the value of natural frequency is important in damping system design [5]. from the fact that resonance between disturbance signal and damping system can be very dangerous, then the natural frequency of the damping system must be lower than force frequency of the disturbance signal. and further, lowering the natural frequency of the damping system can assure the damping condition i.e. the displacement of the damping vibration will be less than the displacement of the disturbance. transmissibility, which is defined as ratio of the displacement of the damping vibration to the displacement of the disturbance vibration, is typically depicted for various damping conditions in figure 3. it is seen from figure 3 that if transmissibility is less than one then the curves will be included in the region of isolation and if the transmissibility is greater than one then the curves will be included in the region of amplification. it can also be seen that if frequency ratio is greater than √2 then the curves will be included in the region of isolation and if the transmissibility is less than √2 then the curves will be included in the region of amplification. the point which is commonly called the resonant point occurs if frequency ratio is one, where the transmissibility will be at its maximum value. internal mechanical energy which constitutes potential energy and kinetic energy of the spring in the damping condition is decreasing. it means that a part of the mechanical energy is converted to heat. further, the damping (d) is defined as the dissipation of energy by conversion to heat. the typical transmissibility curves for various damping conditions are shown in figure 3, and figure 4 presents damping factors for some typical materials. b. shock a rocket machine generates a thrust force. shape of the thrust is normally a pulse forming a square wave form. duration of the pulse which is called burning time for several lapan rockets were environ ten seconds. note that for ten seconds of burning time, the total duration of whole trajectory can achieve up to two hundred seconds. shock occurs at the beginning and the end of the pulse. at the beginning, the shock constitutes transient between zero thrust and nominal thrust, and at the last of the pulse, the shock constitutes transient between nominal thrust and zero thrust. in the research presented in this paper, to solve the shock problems spring and mass system were used. the important step in designing a spring and mass damping system is the step to select natural frequency of the damping system. equation 7 can be applied to design damping system especially in determining the natural frequency: 𝐺𝐺𝑡𝑡 = 𝑉𝑉(𝑓𝑓𝑛𝑛 ) 𝑔𝑔 (7) where gt : transmitted shock (unity) v : velocity (meter per second) fn : natural frequency (hertz) g : acceleration due to gravity (9.81m/sec2) figure 3. typical transmissibility curves [12]. figure 4. typical damping factors [12]. sutisno and a.p. adi / mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 114 the associated dynamic deflection (∆𝑑𝑑) can be determined by: ∆𝑑𝑑 = 𝑉𝑉 2𝜋𝜋𝑓𝑓𝑛𝑛 (8) where ∆𝑑𝑑 : associated dynamic deflection (meter) v : velocity (meter per second) fn : natural frequency (hertz) it is not very different between protecting the equipment in rocketing and in free-fall drop from a certain height. so far we have found that to protect the equipment in free-fall drop we need to calculate: • a system’s natural frequency, • a dynamic deflection, • a stiffness of dynamic system. all of these three conditions must be met to assure that no more than the acceleration value limit is transmitted to the equipment. note that the dynamic stiffness (k) found is the system stiffness. it must be divided by the number of mounts to determine the stiffness required per mount. if both vibration and shock are present, both must be considered. quite often the final solution is a compromise. c. vibration and shock problem in rocket in space technology rocket is classified as a vehicle. in contrast to the aircraft vehicle that its critical moment is when landing, critical moment of the rocket is when launching. problems appearing in a rocket launching, mainly for the large diameter rocket having complex payload, is vibration and shock acting on whole rocket body. this uncontrolled force disturbance working at the embedded control system can cause deflection to the mission during the launching. in rx-320 rocket launching in 2009, the launching mission deflection still existed [11]. the payload functioned just for several seconds, while motor was still firing, then it was suddenly not working properly. this problem does not occur only to lapan’s rocket, but also to rockets belong to several foreign institutes of aeronautics, even nasa’s [2, 3, 4]. the shock and vibration were seriously disturbing nasa’s rockets. rocket vibration oscillates in the range from zero to 2000 hz of frequency, and shock action begins while motor starting until separation time. at separation time the acceleration valued environ 20 g [6, 7]. d. vibration and shock absorption absorption of vibration and shock can be established by applying silicone gel material, as shown in figure 5. the material was selected in line with the fact that silicone material has high typical damping factors more than one of several other materials as tabled in figure 4. the same method and material were also utilized in vibration and shock absorption in the laptop to protect the hard disk from vibration and shock during usage and from accidental fall as shown in figure 5 [8, 10]. absorption method established in rockets usually applied is by using metal spring combined with silicone gel [8, 9]. the spring was not made in spiral form to avoid unbalance while being loaded, as shown detail in figure 6 [8, 13]. instead, the form was omega. iii. test and observation a. vibration test testing installation is shown in figure 7. the tests were done at bppt (puspiptek) laboratory at serpong. compartment standard model of rx200 rocket payload of 4.5 kg of mass was damped using 8 cr2-200 types of enidine damping, and the pcb was covered in several materials of silicone. resulting curves are shown in figure 8. the acceleration was set to be 1 g and the signal disturbance was scanned in 5 hz 2000 hz of frequency figure 5. silicone gel damping application [10]. figure 6. spring damping application. sutisno and a.p. adi / mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 115 b. observation among several curves in figure 8, just two curves representing signals measured. curve (1) showed vibration on the outer pcb box while curve (2) showed vibration on the surface of pcb covered by damping material. the other curves were not installed to the sensors. it was seen that curve (1) and curve (2) had almost the same amplitude at low frequency (80 hz). at medium frequency (80 hz 330 hz), damped vibration amplitude was greater than one outer side (un-damped). this phenomenon indicated appearing resonance between disturbance signals and damping system having medium natural frequency. on the other hand, at high frequency (330 hz to 2000 hz), damped vibration amplitude was falling down under 0.1 g, smaller than signal disturbance amplitude. it meant that the dumping system was relatively good enough and able to reduce 0.9 g of acceleration magnitude. iv. conclusion according to the results of discussion, testing, and observation, it can be concluded that the damping system designed was able to reduce the amplitude significantly. from equation (4), the transmissibility t would be 0.1 at 550 hertz of force frequency. natural frequency of the damping system could be obtained from equation (7): 𝑓𝑓𝑛𝑛 = 550 � 1 0.1 +1 = 166𝐻𝐻𝑧𝑧 in fact, the disturbance frequency measured was 1000 hertz. this value of frequency was relatively high enough comparing to the natural frequency, and it was assuring not to interfere to the natural frequency of the damping system. references [1] ade agung harnawan. (2012, november 28). pegas massa linier. [online]. available: http://adefisika.wordpress.com/2011/05/08/p egas-massa-linier/ [2] r. caimi et.al. rocket launchinduced vibration. nasa report. [3] the associated press. (2008, january 20). new rocket has problem with vibration. [online]. the new york times published. available: http://spectrum.ieee.org. [4] _____________. (2009, september 16). nasa identifies fix for ares 1 vibration. [online]. available: www.spacenews.com/civil/fix-for-aresvibration-issue.html [5] mechanical brothers. (2012, november 28). frekuensi pribadi (natural frequency) dan putaran kritis (critical speed). [online]. available: http://mechanicalbrothers.wordpress.com/20 11/01/08/frekuensi-pribadi-natural figure 8. amplitude vs. frequency curves for some testing points. figure 7. vibration testing. http://adefisika.wordpress.com/2011/05/08/pegas-massa-linier/ http://adefisika.wordpress.com/2011/05/08/pegas-massa-linier/ http://mechanicalbrothers.wordpress.com/2011/01/08/frekuensi-pribadi-natural-frequency-dan-putaran-kritis-critical-speed/ http://mechanicalbrothers.wordpress.com/2011/01/08/frekuensi-pribadi-natural-frequency-dan-putaran-kritis-critical-speed/ sutisno and a.p. adi / mechatronics, electrical power, and vehicular technology 03 (2012) 111-116 116 frequency-dan-putaran-kritis-critical-speed/ [6] agus harno et.al, “on-board fundamental frequency estimation of rocket flight experiments using dsp microcontroller and accelerometer,” jurnal nasional dirgantara, 2009. [7] t. srinivas reddy et.al, “design and analysis of vibration test bed fixtures for space launch vehicles,” indian journal of science and technology, vol. 3 no. 5, may 2010. [8] donghyun hwang et.al, “vibration reduction module with flexure springs for personal tools,” world academy of science, engineering and technology 56, 2009. [9] holter warren g, “vibration reduction for electric motors,” us patent 07/985,097, 1997. [10] shin, sang-chul, “hard disk drive comprising flexible printed circuit with damping material," us patent 10/288507, 2002. [11] lapan, laporan tahunan bidang kendali 2009. [12] advanced vibration components. (2012, november 14). technical section: vibration and shock isolation. [online]. available: www.vibrationmounts.com [13] enidine. (2012, november 14). wire rope isolator catalog. [online]. available: www.enidine.com http://www.vibrationmounts.com/ http://www.enidine.com/ foreword from editor-in-chief list of contents fungsi swept eksitasi swept-sine respon sistem frf sistem data-data simulasi the schematic of ald system reaction mechanism mems devices dynamic random access memory (dram) kekuatan mekanik sambungan efek pemanasan pada sambungan hasil pengukuran tahanan kontak sambungan busbar tembaga hasil pengukuran temperatur kontak biogas formation and the bacteria involved anaerobic digestion of soybean curd waste water and active digester effluent as a starter the calculation of the potentiality for power generation the effect of the addition of active digester effluent the potentiality for power generation the existence of forces on pmg thermal expansion designing rim shaft design finite element method rim deflection shaft deflection deflection due to thermal expansion of the material total deflection on the structure of pmg control circuit control algorithm design of wind generator simulator rig filtering of output voltage results of wind generator simulator rig simulation results of inverter experiment results of inverter starting motion full motion ending motion angle value between reference lines reference line value angle value at hip joint, knee joint and ankle joint hip height equations step distance equation height of swinging leg equations mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.113-124 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: m. l. ramadiansyah et al., “numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted twodof manipulator system,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 113-124, dec. 2022. numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system mohamad luthfi ramadiansyah a, *, edwar yazid a, cheng yee ng b a research center for smart mechatronics, national research and innovation agency (brin) kawasan bandung cisitu, jl. sangkuriang, dago, coblong, bandung, 40135, indonesia b department of civil and environmental engineering, universiti teknologi petronas 32610 seri iskandar, perak, malaysia received 17 october 2022; revised 16 november 2022; accepted 17 november 2022; published online 29 december 2022 abstract the dynamics of a ship need to be considered in the development of a manipulator system that will be applied to the ocean-based operation. this paper aims to investigate the effect of ocean depth variations on the ship motion as disturbances to a ship-mounted two-dof (degrees of freedom) manipulator joint torque using an inverse dynamics model. realization is conducted by deriving the mathematical model of a two-dof manipulator system subject to six-dof ship motion, which is derived by using lagrange-euler method. it is then combined with numerical hydrodynamic simulation to obtain the ship motions under ocean depth variations, such as shallow (50 m), intermediate (750 m), and deep (3,000 m) waters. finding results show that randomness of the ship motions appears on the manipulator joint torque. in the azimuth link, maximum joint torque is found in shallow water depth with an increment of 8.271 n.m (285.69 %) from the undisturbed manipulator. meanwhile, the maximum joint torque of the elevation link is found in intermediate water depth with an increment of 53.321 n.m (6.63 %). however, the difference between depth variations is relatively small. this result can be used as a baseline for sizing the electrical motor and developing the robust control system for the manipulator that is mounted on the ship by considering all ocean depth conditions. ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: two-dof manipulator; inverse dynamics; ship motion; ocean depth; hydrodynamic response. i. introduction it is widely known that robotic systems may be easily found in many engineering applications. design and analysis of such a system has been carried out in some areas, such as industrial application [1][2], underwater [3], vehicle [4], satellite antenna [5], and humanoid robot [6][7] with their specified objectives. the essential task in developing a robotic system is kinematics and dynamics modeling. kinematics modeling is commonly carried out to determine the position and orientation of manipulator links. tavassolian et al. [8] had employed the forward kinematics model of a parallel robot using a combined method based on the neural network. dewandhana et al. [9] had similar work but with a different application, i.e., a full-arm robot. inverse kinematics had been performed by kusmenko and schmidt [10] for developing a 5-dof (degrees of freedom) robot arm and by chen et al. [11] for an underwater propeller cleaning application. amundsen et al. [12] had performed inverse kinematics for manipulator control that was implemented on a non-fixed based. inverse dynamics model is commonly used to obtain the dynamic characteristics of a manipulator system. it was implemented by polydoros et al. [13] for torque control manipulator, awatef and mouna [14] for motion control of the unicycle mobile robot, and crenna and rossi [15] for measurement of internal torques in the articulations of the human body during a gesture. the calculation of inverse dynamics using computational methods is currently well-known for its efficient purpose. farah and shaogang [16] had introduced an efficient approach * corresponding author. tel: +62-878-2460-7227 e-mail address: moha057@brin.go.id https://dx.doi.org/10.14203/j.mev.2022.v13.113-124 https://dx.doi.org/10.14203/j.mev.2022.v13.113-124 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.113-124 https://dx.doi.org/10.14203/j.mev.2022.v13.113-124 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.113-124&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 114 for modeling robot dynamics. they used matlab and simmechanics instead of an analytical approach, but the study was limited to ground-based applications. meanwhile, müller [17] had compared classical and computational methods. besides to fulfill its function, the development of a robotic system must consider the behavior of its base, in which the system will be operated. dynamics of the non-inertial base certainly affect the positioning of manipulator arms which is the main task of a robotic system. wei et al. [18] had performed a dynamic analysis of a mobile manipulator that operated on the 3-dof floating base. similar work of non-inertial base manipulator had been done by [19], which introduced the modeling and control of a soft robotic arm on the aerial vehicle. to the best of the author’s knowledge, dynamic analysis of a manipulator excited by ship motions is relatively rare. some literature that relates to this topic may be found in [20][21][22], although they mainly focused on the control system development. research by qian and fang in [23] is regarded as the closest work where they had analyzed the regular ocean waves effect to the dynamic analysis of a shipmounted crane system. further, dynamics of manipulator systems subject to irregular ocean waves induced ship motions had been performed by [24] under variations of sea states. important finding results show that the maximum joint torque of a manipulator is proportional to the increment of significant wave height and greatly affected by the direction of ocean wave propagation. to date, there has not yet been research working on the effect of ocean depths on manipulator dynamics. ahmed et al. [25] presented that the water particle force on the oceanic structure depends on the ocean depth. hence, this paper investigates the effect of ocean depth variations on the manipulator joint torque with contributions as follows: • to develop a mathematical model of a shipmounted two-dof manipulator considering the ship dynamics. • to characterize the ship motions as excitations to the base of a manipulator system subject to random ocean waves under variations of ocean depth using numerical hydrodynamic simulation and propose its methodology. • to perform a parametric study in terms of variations of ocean depth to the manipulator dynamics. this paper is organized as follows: system description and the underlying method, as well as the governing equations, are described in section ii. results and discussions of derived governing equations, numerical simulations, and manipulator dynamic characteristics are presented in section iii. conclusion and recommendations are put in section iv. ii. materials and methods the underlying manipulator construction is illustrated in figure 1, where it has two degrees of freedom, namely azimuth and elevation links. the former is designed to be able to fully rotate in the horizontal plane with a maximum angle of 360° c(c)w, while the elevation angle can rotate in the vertical plane with a range angle at -20° ~ 60° c(c)w. the end-effector is designed to aim and lock on the target on the ocean water surface. a control system must be applied to move the arms at certain angles precisely when the base of the manipulator is excited by random ocean waves induced ship motions. this is in order to enable the end-effector to stick to the target. moreover, ship motions are treated as a six-dof rigid body, as visualized in figure 2 under non-propelled conditions. respectively in the x, y, and z axis, translational motions are called surge, sway, and heave, and rotational motions are roll, pitch, and yaw. to calculate manipulator joint torque, the inverse dynamics model is applied, and the process flow is shown in figure 3. the ship motions can be measured with a motion sensor unit, which has three accelerometers for detecting surge, sway, and heave and three rotation rate sensors for measuring roll, pitch, and yaw [26]. in this paper, a combination figure 1. schematic of a manipulator system m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 115 of analytical and numerical methods is proposed to simulate ship motions and manipulator joint trajectory from the sensor system. the former is analytical simulations of joint trajectory and manipulator dynamics, and the latter is a numerical simulation of the ship motions using ansys aqwa in the variations of ocean depth. here, equations of motion of a ship-mounted manipulator system are derived by using lagrange-euler method. thus, discussion with regard to control system design and analysis, including sensor system, is out of this paper’s range. to begin with, the main parameters of the manipulator system and ship geometry are given with certain conditions applied. a. forward kinematics kinematics of a ship-mounted manipulator system as an early step in the dynamic analysis is realized in the form of forward and inverse kinematics. the former is defined from the base to the end-effector using manipulator joint parameters and coordinates, as noted in figure 1. a homogeneous transformation matrix of the system is then built based on the widely adopted denavithartenberg (dh) method [27] by multiplying each homogeneous transformation matrix of the joint from the base into the end-effector. homogeneous transformation matrix (𝑇) consists of a rotational matrix (𝑅) and position matrix (𝑃), which is defined as equation (1), 𝑇 = �𝑅𝑛,𝑠,𝑎 𝑃𝑋,𝑌,𝑍 0 1 � = � 𝑛𝑋 𝑠𝑋 𝑎𝑋 𝑃𝑋 𝑛𝑌 𝑠𝑌 𝑎𝑌 𝑃𝑌 𝑛𝑍 𝑠𝑍 𝑎𝑍 𝑃𝑍 0 0 0 1 � (1) the terms, 𝑠 and 𝑎 denote normal, shear, and approach vectors in the xyz-axes. using manipulator frame coordinates in figure 1, the total homogeneous transformation matrix can be written as equation (2), 𝐻 = 𝑇𝑆. 𝑇𝑀. (2) the term 𝐻 is the total, 𝑇𝑆 is the ship, and 𝑇𝑀 is the manipulator homogeneous transformation matrices, respectively. the homogeneous transformation matrix of a ship can be expressed as equation (3), 𝑇𝑠 = � 𝑐𝑐𝑐𝑐 𝑠𝑐𝑐𝑐 𝑐𝑐𝑠𝑐𝑠𝑐 − 𝑠𝑐𝑐𝑐 𝑠𝑐𝑠𝑐𝑠𝑐 + 𝑐𝑐𝑐𝑐 𝑐𝑐𝑐𝑐𝑠𝑐 + 𝑠𝑐𝑠𝑐 𝑋𝑠 𝑠𝑐𝑠𝑐𝑐𝑐 − 𝑐𝑐𝑠𝑐 𝑌𝑠 −𝑠𝑐 𝑐𝑐𝑠𝑐 𝑐𝑐𝑐𝑐 𝑍𝑠 0 0 0 1 � (3) the term 𝑐 and 𝑠 represent cos and sin; 𝑋𝑠, 𝑌𝑠, and 𝑍𝑠 are the translational ship motions, such as surge, figure 2. visualization of ship motions figure 3. steps for simulating the inverse dynamics of a manipulator system m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 116 sway, and heave, respectively; and 𝑐, 𝑐, and 𝑐 are the rotational ship motions, namely roll, pitch, and yaw, respectively. the homogeneous transformation matrix of manipulator system can be written as equation (4) and equation (5), 𝑇𝑀 = 𝑇𝑀1 0 . 𝑇𝑀 212 0 (4) 𝑇𝑖 𝑖−1 𝑀 = ⎣ ⎢ ⎢ ⎡ 𝑐𝜃𝑙𝑖 𝑐𝛼𝑖−1𝑠𝜃𝑙𝑖 −𝑠𝜃𝑙𝑖 𝑐𝛼𝑖−1𝑐𝜃𝑙𝑖 0 𝑎𝑖−1 −𝑠𝛼𝑖−1 −𝑠𝛼𝑖−1𝑑𝑖 𝑠𝛼𝑖−1𝑠𝜃𝑙𝑖 𝑐𝜃𝑙𝑖𝑠𝛼𝑖−1 𝑐𝛼𝑖−1 −𝑐𝛼𝑖−1𝑑𝑖 0 0 0 1 ⎦ ⎥ ⎥ ⎤ (5) the term 𝑇𝑖 𝑖−1 𝑀 is the transformation matrix from the 𝑖 − 1 frame to 𝑖 frame, 𝜃𝑙 is joint angle, 𝛼𝑖−1 is the rotational link angles in x-axis, 𝑎 and 𝑑 are respective link distances in the xand z-axes. using manipulator kinematic parameters of the link in table 1, equation (5) can be rewritten for each joint as equation (6) and equation (7), 𝑇𝑀 = � 𝑐𝜃𝑙𝑖 −𝑠𝜃𝑙𝑖 0 0 𝑠𝜃𝑙𝑖 𝑐𝜃𝑙𝑖 0 0 0 0 0 0 1 0 0 1 �1 0 (6) 𝑇𝑀 = � 𝑐𝜃𝑙2 −𝑠𝜃𝑙2 0 0 0 0 −1 0 𝑠𝜃𝑙2 0 𝑐𝜃𝑙2 0 0 0 0 1 �21 (7) b. inverse dynamics an inverse dynamics model is used to define the manipulator joint torque with predefined joint trajectories. the torque can be expressed in several terms, such as inertia, centrifugal, coriolis, and gravity as equation (8), 𝜏 = 𝑀(𝛩)�̈� + 𝑉�𝛩, �̇�� + 𝐺(𝛩) (8) the term 𝜏 is manipulator joint torque, 𝑀 is the mass matrix that contributes to the torque due to inertia, 𝑉 is the matrix of centrifugal and coriolis terms, and 𝐺 is the matrix of gravity term [28]. recall the euler’s equation, the torque value is defined as equation (9), 𝑑 𝑑𝑑 𝜕𝜕 𝜕�̇� − 𝜕𝜕 𝜕𝛩 = 𝜏 (9) 𝐿�𝛩, �̇�� = 𝐾�𝛩, �̇�� − 𝑃(𝛩) (10) the term 𝐿 is the lagrange operator, 𝛩 is position, �̇� is velocity, and �̈� is acceleration of the joint. lagrange formulation is defined as the difference between kinetic energy (𝐾) and potential energy (𝑃) following equation (10). substituting equation (10) into equation (9), it can be written as equation (11), 𝜏𝑖 = 𝑑 𝑑𝑑 𝜕𝐾𝑖 𝜕�̇� − 𝜕𝐾𝑖 𝜕𝛩 + 𝜕𝑃𝑖 𝜕𝛩 (11) kinetic energy is obtained from translational and rotational motions, while potential energy is due to gravity effect as equation (12) and equation (13), 1 1 2 2 i i i ct i t i i i c c i i ik m v v iω ω= + (12) 0 i t i i cp m g p= (13) the term 𝑚𝑖 is mass, 𝑣𝑐 is linear velocity at the centre of gravity, 𝜔 is angular velocity, 𝐼 is the moment of inertia of the link, 𝑔 is gravity, and 𝑃𝑐 is position matrix from the homogeneous transformation matrix. all variables in equations (12)(13) are transformed into matrix form where the mass and moment of inertia of each link follow the manipulator design parameters. linear and angular velocities can be obtained from velocity propagation as equation (14) and equation (15), ( )1 1 11 1 1 1ˆi i i i i ii i i i i i iv r v p d zω+ + ++ + + += + × +  (14) 1 1 1 1 1 1 ˆi i i i i i i i ir zω ω θ + + + + + += +  (15) the term 𝑅 is rotational matrix from homogeneous transformation matrix, �̇� is linear velocity, �̇� is angular velocity, and �̂� is direction vector of the joint. it should be noted that the manipulator joint motion is predefined using a 5thorder spline function. c. ship motions ship motions are carried out by numerical simulation using commercial software. in this paper, ansys aqwa is employed to simplify the process from the ship modelling until the ship motions analysis. this type of software provides a toolset for investigating the effects of environmental loads on floating and fixed offshore as well as marine structures. this software can also be used to analyze the hydrodynamic diffraction and responses of a body subject to ocean waves. overall, hull modelling, meshing process, and ocean waves generation subject to the ocean depth are evaluated by ansys aqwa. 1) ship hull modelling in practice, a ship model can be simplified into a hull model, which can be seen in figure 4. the hull interacts with ocean waves so that it becomes the main geometry that must be modeled properly. in aqwa, modelling is based on surface geometry that may be designed from a geometry editor in ansys or other modelling softwares in the form of *.stp or *.igs files. in this paper, solidworks in *.stp format is used and then imported into a geometry editor in aqwa. 2) meshing process the meshing process is performed in aqwa. boundary conditions and parameters of the ship are tabulated in table 2. however, the current meshing process is different from the common cfd mesh, where the working fluid is set as the object. here, the ship hull is the mesh object, as seen in figure 5. it shows the surface mesh of the ship hull and the table 1. manipulator kinematic parameters i θl α a d 1 𝜃𝑙1 0 0 0 2 𝜃𝑙2 90 o 0 0 3 0 0 0 r m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 117 grid independence test result that corresponds to the hydrostatic heave as the parameter for determining the effective total elements. at the 22,210 elements, the hydrostatic value has approached the correct value and it becomes the meshing parameter hereafter. using the higher elements can result in long-time iteration in the simulation process. 3) ship and ocean random waves interaction modelling random ocean waves are applied rather than regular ocean waves since they represent the actual ocean waves. adopted from linear airy wave theory [29], random ocean wave height is a summation of regular waves with different frequencies. jonswap type spectrum is used, which is the standard ocean wave model and more versatile than other spectrums. its spectral ordinate at a frequency (𝜔) is expressed as equation (16), 𝑆(𝜔) = 𝛼𝐻𝑠2 � 𝜔𝑝4 𝜔5 � exp �−5 4 � 𝜔𝑝 𝜔 � 4 �𝛾 exp�− �𝜔−𝜔𝑝� 2 2𝜎2𝜔𝑝 2 � (16) the term 𝛼 is a phillip’s constant, 𝐻𝑠 is significant wave height, 𝜔𝑝 is peak frequency, 𝛾 is peakedness parameter, 𝜎 is shape parameter [24]. by taking the values of spectral ordinate ( )ωs , the amplitude of the i-th ocean wave component can be calculated by using equation (17), 𝑎𝑖 = �2𝑆(𝜔𝑖)𝛥𝜔 (17) from equation (17) and the values of 𝑎𝑖, the time series of wave height can be generated as equation (18), 𝜉(𝑥, 𝑦, 𝑡) = ∑  𝑎𝑖 𝑠𝑖𝑛(𝜔𝑖𝑡 + 𝜃𝑖 − 𝑘𝑖𝑥𝑐𝑐𝑠𝜒 − 𝑘𝑖𝑦𝑠𝑖𝑛𝜒)𝑁𝑖=0 (18) the term 𝜉 is wave elevation, 𝑁 is number of wave component, 𝑘 is wave number, and 𝜒 is wave propagating direction. from linear wave theory, wave particle kinematics can be expressed as equations (19)–(23), 𝑣𝑥 = 𝜔𝜁𝑎 𝑐𝑐𝑠ℎ[𝑘(𝑧+ℎ)] 𝑠𝑖𝑛ℎ(𝑘ℎ) 𝑐𝑐𝑠(𝑘𝑥 − 𝜔𝑡) (19) 𝑣𝑧 = 𝜔𝜁𝑎 𝑠𝑖𝑛ℎ[𝑘(𝑧+ℎ)] 𝑠𝑖𝑛ℎ(𝑘ℎ) 𝑠𝑖𝑛(𝑘𝑥 − 𝜔𝑡) (20) 𝑎𝑥 = 𝜔2𝜁𝑎 𝑐𝑐𝑠ℎ[𝑘(𝑧+ℎ)] 𝑠𝑖𝑛ℎ(𝑘ℎ) 𝑠𝑖𝑛(𝑘𝑥 − 𝜔𝑡) (21) 𝑎𝑧 = 𝜔2𝜁𝑎 𝑠𝑖𝑛ℎ[𝑘(𝑧+ℎ)] 𝑠𝑖𝑛ℎ(𝑘ℎ) 𝑐𝑐𝑠(𝑘𝑥 − 𝜔𝑡) (22) 𝑝𝐷 = 𝜌𝑔𝜁𝑎 𝑐𝑐𝑠ℎ[𝑘(𝑧+ℎ)] 𝑐𝑐𝑠ℎ(𝑘ℎ) 𝑐𝑐𝑠(𝑘𝑥 − 𝜔𝑡) (23) the term 𝑣𝑥 and 𝑣𝑧 are horizontal and vertical water particle velocity, 𝑎𝑥 and 𝑎𝑧 are horizontal and figure 4. geometry of ship hull surface table 2. ship parameters in meshing process parameter value defeaturing tolerance (m) 0.15 maximum element size (m) 0.35 total nodes 22,484 total elements 22,210 density of water (kg/m3) 1025 water length and width (m) [300; 200] gravitational acceleration (m/s2) 9.81 draught (m) 3.13 breadth (m) 9.5 length between perpendiculars (m) 53.25 mass (kg) 600858 radius of gyration (m) [3.179; 13.313; 13.845] center of gravity (m) [0; 0; 0] center of buoyancy (m) [0; 0; 0.83] m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 118 vertical water particle acceleration, 𝑝𝐷 is dynamic pressure, 𝜌 is water density, 𝜁𝑎 is wave height, 𝑡 is time, and ℎ is water depth. impulse of the wave particles will cause motion of the ship hull. the equation of motion is expressed in a convolution integral form as equation (24), (m + a∞)x ¨(𝑡) + c x ˙(𝑡) + kx(𝑡) + ∫ r(𝑡 − 𝑑 0 𝜏)x ˙(𝜏)𝑑𝜏 = f(𝑡) (24) the term 𝑚 is structural mass matrix, 𝐴∞ is fluid added mass matrix at infinite frequency, 𝑐 is damping matrix including the linear radiation damping effects, 𝐾 is total stiffness matrix, 𝑅 is velocity impulse function matrix, and 𝑋, �̇�, and �̈� are respectively matrices of position, velocity, and acceleration of the ship. an integration of equation (24) is held numerically by aqwa using parameters in table 2. ship motion analysis is carried out in three classifications of ocean depth, such as shallow, intermediate, and deep waters, as shown in table 3, which have an effect on the speed of ocean waves table 3. random ocean waves parameters ocean classification depth (m) significant wave height (m) wave frequency (hz) sea state shallow 50 2 0.50 moderate intermediate 750 0.48 deep 3000 0.46 (a) (b) figure 5. result of meshing process, (a) hull surface mesh; (b) grid independence test m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 119 [30]. equations (19)-(23) fortify that the kinematics of the wave particle is the function of ocean depth. once the simulation is completed, six-dof ship motion can be obtained and applied to the calculation in equation (11). iii. results and discussions the results of the analytical derivation of manipulator joint torque using the lagrange-euler method are tabulated in table 4 for the azimuth angle and table 5 for the elevation angle. the equations are classified into dynamic terms for clarity. they have been validated by excluding the terms of ship motions, and the results are similar to those without ship motions. those terms are then utilized by substituting manipulator parameters in table 6 and joint trajectories in figure 6, which consist of both azimuth and elevation joints position, velocity, and acceleration over 30 s. the joint angles are obtained from the inverse kinematics process [31] and their trajectories are generated using the 5th-order spline function. as can be seen, smoothness of joint position, velocity, and acceleration can be obtained. as mentioned in the previous section, ship motions are obtained using numerical simulation through hydrodynamic time response analysis in table 4. dynamic terms for azimuth angle term torque inertia �𝐼𝑧𝑧1 + 𝐼𝑥𝑥2 𝑠𝑖𝑛 2 𝜃𝑙2 + �𝐼𝑦𝑦2 + 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠2 𝜃𝑙2��̈�𝑙1 +�−𝑚2𝑟𝑥2 𝑠𝑖𝑛𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̈�𝑆 +�𝑚2𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̈�𝑆 + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̈� + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̈� +�𝐼𝑧𝑧1 + 𝐼𝑥𝑥2 𝑠𝑖𝑛 2 𝜃𝑙2 + �𝐼𝑦𝑦2 + 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠2 𝜃𝑙2��̈� coriolis ��𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙2��̇�𝑙1�̇�𝑙2 +���𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 2 𝜃𝑙2 − 𝐼𝑧𝑧2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 𝜃𝑙1��̇�𝑙2�̇� +���𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 2 𝜃𝑙2 − 𝐼𝑧𝑧2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 𝜃𝑙1��̇�𝑙2�̇� +��𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙2��̇�𝑙2�̇� +�𝑚2𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̇�𝑆�̇� +�𝑚2𝑟𝑥2 𝑠𝑖𝑛 𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̇�𝑆�̇� +�−𝑚2𝑟𝑥2 𝑐𝑐𝑠𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̇�𝑆�̇� +�−𝑚2𝑟𝑥2 𝑠𝑖𝑛𝜃𝑙1 𝑐𝑐𝑠 𝜃𝑙2��̇�𝑆�̇� +�−�𝐼𝑥𝑥1 − 𝐼𝑦𝑦1 − 𝐼𝑧𝑧2 − 𝑚2𝑟𝑥2 2 + �𝐼𝑦𝑦2 + 𝑚2𝑟 2�𝑠𝑖𝑛2 𝜃𝑙2 + 𝐼𝑥𝑥2 𝑐𝑐𝑠 2 𝜃𝑙2�𝑐𝑐𝑠 2 𝜃𝑙1��̇��̇� + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̇��̇� + �− 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̇��̇� centripetal � 1 2 �𝐼𝑥𝑥1 − 𝐼𝑦𝑦1 − 𝐼𝑧𝑧2 − 𝑚2𝑟𝑥2 2 + �𝐼𝑦𝑦2 + 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛2 𝜃𝑙2 + 𝐼𝑥𝑥2 𝑐𝑐𝑠 2 𝜃𝑙2�𝑠𝑖𝑛 2 𝜃𝑙1��̇� 2 + �− 1 2 �𝐼𝑥𝑥1 − 𝐼𝑦𝑦1 − 𝐼𝑧𝑧2 − 𝑚2𝑟𝑥2 2 + �𝐼𝑦𝑦2 + 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛2 𝜃𝑙2 + 𝐼𝑥𝑥2 𝑐𝑐𝑠 2 𝜃𝑙2�𝑠𝑖𝑛 2 𝜃𝑙1��̇� 2 gravity 𝑚2𝑔𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙2 �𝑠𝑖𝑛𝜃𝑙1 𝑠𝑖𝑛 𝑐 + 𝑐𝑐𝑠 𝜃𝑙1 𝑠𝑖𝑛 𝑐 𝑐𝑐𝑠𝑐� figure 6. manipulator joint trajectories 0 10 20 30 -100 0 100 200 300 400 l ( o ) azimuth elevation 0 10 20 30 -10 0 10 20 30 l( o /s ) 0 10 20 30 time (s) -3 -1.5 0 1.5 3 l ( o /s 2 ) m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 120 ansys aqwa subject to the three ocean depths. as part of the hydrodynamic response study, an exhaustive time domain response analysis examines the various effects of irregular wave loads on the dynamic responses of the ship [32]. figure 7 shows three time series of ocean wave height and its corresponding six-dof ship motion. it is clearly seen that the wave height is inversely proportional to the ocean depth following equation (20) and equation (22). shallow water produces higher ocean wave height so that the amplitudes of the surge, sway, and yaw motions become higher than the other motions. on the contrary, the dynamic pressure of the ocean wave is directly proportional to the ocean depth following equation (23), implying that lifting motions such as heave, roll, and pitch have higher amplitudes in deep water. those results are then fed into dynamic terms in table 4 and table 5, along with predefined joint trajectories. torque comparisons between an undisturbed manipulator (without ship motions) and a disturbed manipulator (with ship motions) in shallow water are then investigated and displayed in figure 8 and figure 9, respectively. those figures present the distributions of joint torque for each dynamic term of azimuth and elevation links. as can be observed, the inertia term is the most dominant torque to the manipulator for the azimuth link, while the gravity term is found to be dominant in the elevation link. this is to be expected since gravity works on the axis of rotation of the elevation link. further, a comparison between undisturbed and disturbed manipulators under variations of ocean depth is revealed in figure 10. it is apparent that the ship motions greatly affect the values of manipulator joint torque. the values fluctuate around the value of the undisturbed manipulator for all ocean depths, become unstable and increase to certain maximum values in order to maintain the position of the endeffector. it is found that shallow water produces the highest torque value in azimuth angle, where the increment is around 8.271 n.m or 285.69 % from the undisturbed manipulator. intermediate water produces the highest torque in elevation angle, where the increment is around 53.321 n.m or 6.63 %. the performance of manipulator joints in terms of angular speed and torque is then compiled in table 7 to support the results in figure 10. table 5. dynamic terms for elevation angle term torque inertia �𝐼𝑧𝑧2 + 𝑚2𝑟𝑥2 2��̈�𝑙2 +�−𝑚2𝑟𝑥2 𝑐𝑐𝑠𝜃𝑙1 𝑠𝑖𝑛 𝜃𝑙2��̈�𝑆 +�−𝑚2𝑟𝑥2 𝑠𝑖𝑛𝜃𝑙1 𝑠𝑖𝑛 𝜃𝑙2��̈�𝑆 +�𝑚2𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙2��̈�𝑆 +��𝐼𝑧𝑧2 + 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 𝜃𝑙1��̈� +�−�𝐼𝑧𝑧2 + 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠𝜃𝑙1��̈� coriolis ��−�𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 2 𝜃𝑙2 + 𝐼𝑧𝑧2 + 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 𝜃𝑙1��̇�𝑙1�̇� +��−�𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 2 𝜃𝑙2 + 𝐼𝑧𝑧2 + 𝑚2𝑟 2�𝑠𝑖𝑛𝜃𝑙1��̇�𝑙1�̇� +�−�𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙2��̇�𝑙1�̇� +�−𝑚2𝑟𝑥2 𝑐𝑐𝑠𝜃𝑙2��̇�𝑆�̇� +�−𝑚2𝑟𝑥2 𝑠𝑖𝑛𝜃𝑙1 𝑠𝑖𝑛 𝜃𝑙2��̇�𝑆�̇� +�𝑚2𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙2��̇�𝑆�̇� +�𝑚2𝑟𝑥2 𝑐𝑐𝑠 𝜃𝑙1 𝑠𝑖𝑛 𝜃𝑙2��̇�𝑆�̇� +�𝑚2𝑟𝑥2 𝑠𝑖𝑛 𝜃𝑙1 𝑠𝑖𝑛𝜃𝑙2��̇�𝑆�̇� +�−𝑚2𝑟𝑥2 𝑐𝑐𝑠𝜃𝑙1 𝑠𝑖𝑛 𝜃𝑙2��̇�𝑆�̇� + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̇��̇� +�−�𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠 𝜃𝑙1 𝑐𝑐𝑠 2 𝜃𝑙2��̇��̇� +�−�𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 𝜃𝑙1 𝑐𝑐𝑠 2 𝜃𝑙2��̇��̇� centripetal �− 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙2��̇�𝑙1 2 + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑐𝑐𝑠2 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̇� 2 + � 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛2 𝜃𝑙1 𝑠𝑖𝑛 2 𝜃𝑙2��̇� 2 + �− 1 2 �𝐼𝑥𝑥2 − 𝐼𝑦𝑦2 − 𝑚2𝑟𝑥2 2�𝑠𝑖𝑛 2 𝜃𝑙2��̇� 2 gravity 𝑚2𝑔𝑟𝑥2�𝑠𝑖𝑛𝜃𝑙2 �𝑐𝑐𝑠𝜃𝑙1 𝑠𝑖𝑛 𝑐 − 𝑠𝑖𝑛 𝜃𝑙1 𝑠𝑖𝑛 𝑐 𝑐𝑐𝑠𝑐� + 𝑐𝑐𝑠 𝜃𝑙2 𝑐𝑐𝑠𝑐 𝑐𝑐𝑠 𝑐� table 6. parameters of manipulator parameter value mass (kg) m1 = 150; m2 = 128 coordinates of cog (m) rx1 = 0.00; ry1 = 0.19; rz1 = 0.00; rx2 = 0.64; ry2 = 0.45 rz2 = 0.40 inertia moment at cog (kg.m2) ixx1 = 4.25; iyy1 = 5.45; izz1 = 5.98; ixy1 = 0.043; iyz1 = 0.553; ixz1 = 0.012; ixx2 = 0.108; iyy2 = 14.745; izz2 = 14.74; ixy2 = 0.083; iyz2 = 0.002; ixz2 = 0.019 gravity (m/s2) gx = 0; gy = 0; gz = 9.81 m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 121 this is to be expected since shallow water produces the highest amplitude in yaw motion, which is the variable of the inertia term in azimuth angle. the maximum torque of elevation angle is produced in intermediate water depth because the highest amplitude in roll motion is achieved in figure 7. ship motions subject to ocean depth variation (a) (b) figure 8. azimuth torque distribution: (a) undisturbed; (b) in shallow water 0 10 20 30 time (s) -3 -2 -1 0 1 2 3 4 l 1 ( n .m ) inertia coriolis centripetal gravity total 0 10 20 30 time (s) -15 -10 -5 0 5 10 l 1 ( n .m ) m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 122 intermediate water depth in the first 7 s of response since gravity term, as the main contributor of the elevation angle, contains roll motion. the results show that maximum torque between applied ocean depth variations has small differences. (a) (b) figure 9. elevation torque distribution: (a) undisturbed; (b) in shallow water (a) (b) figure 10. dynamic joint torques: (a) azimuth; (b) elevation 0 10 20 30 time (s) -200 0 200 400 600 800 1000 l2 ( n .m ) inertia coriolis centripetal gravity total 0 10 20 30 time (s) -200 0 200 400 600 800 1000 l2 ( n .m ) 0 5 10 15 20 25 30 time (s) -15 -10 -5 0 5 10 l1 ( n .m ) shallow middle deep undisturbed 0 5 10 15 20 25 30 time (s) 300 400 500 600 700 800 900 l2 ( n .m ) m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 123 iv. conclusion a ship-mounted two-dof manipulator dynamics under the variations of ocean depth have been investigated in this paper. the results are obtained by combining the mathematical model of the manipulator system with the numerical simulation of ship motions. finding results show that randomness of ship motions appears in joint torque in terms of oscillations, resulting in higher maximum torque values than the manipulator without ship motions. shallow water produces maximum joint torque to the azimuth angle with an increment of 8.271 n.m (285.69 %) from the undisturbed manipulator. meanwhile, intermediate water produces a maximum joint torque value to the elevation angle with an increment of 53.321 n.m (6.63 %). however, the difference between water depth variations is relatively small. current results can be taken as a baseline for sizing the electrical motor of the manipulator system and the development of a robust control system. experimental work is recommended as future work to validate simulation results. acknowledgements the authors are grateful to the national research and innovation agency (brin), especially research center for smart mechatronics for providing the research facility and also to the ministry of finance of the republic of indonesia for financial support through the lpdp scheme with the project no. prj92/lpdp/2020. declarations author contribution m.l. ramadiansyah: writing original draft, writing review & editing, conceptualization, investigation, visualization, data curation. e. yazid: writing review & editing, conceptualization, supervision, validation, funding acquisition. c.y. ng: formal analysis, resources, software, validation, visualization. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] t. lauß, s. oberpeilsteiner, k. sherif, and w. steiner, “inverse dynamics of an industrial robot using motion constraints,” in 2019 20th international conference on research and education in mechatronics (rem), pp. 1-7, 2019. [2] n. ramadhan, n. lilansa, a. rifa’i, and h. nguyen, “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 1–14, 2022. [3] s. k. deb, j. h. rokky, t. c. mallick, and j. shetara, “design and construction of an underwater robot,” in 2017 4th international conference on advances in electrical engineering (icaee), pp. 281–284, 2017. [4] y. zhao et al., “a vehicle handling inverse dynamics method for emergency avoidance path tracking based on adaptive inverse control,” ieee trans veh technol, vol. 70, no. 6, pp. 5470–5482, 2021. [5] m. reza chalak qazani, h. asadi, s. mohamed, s. nahavandi, j. winter, and k. rosario, “a real-time motion control tracking mechanism for satellite tracking antenna using serial robot,” in 2021 ieee international conference on systems, man, and cybernetics (smc), pp. 1049–1055, 2021. [6] k. kaneko et al., “humanoid robot hrp-5p: an electrically actuated humanoid robot with high-power and wide-range joints,” ieee robot autom lett, vol. 4, no. 2, pp. 1431–1438, 2019. [7] z. huang, x. jiang, h. liu, x. chen, t. fukuda, and q. huang, “design of crawling motion for a biped walking humanoid with 3-dof rigid-flexible waist,” in 2018 ieee-ras 18th international conference on humanoid robots (humanoids), pp. 974–979, 2018. [8] f. tavassolian, h. khotanlou, and p. varshovi-jaghargh, “forward kinematics analysis of a 3-prr planer parallel robot using a combined method based on the neural network,” in 2018 8th international conference on computer and knowledge engineering (iccke), pp. 320–325, 2018. [9] w. dewandhana, k. i. apriandy, b. s. b. dewantara, and d. pramadihanto, “forward kinematics with full-arm analysis on ‘t-flow’ 3.0 humanoid robot,” in 2021 international electronics symposium (ies), pp. 356–361, 2021. [10] d. kusmenko and k. schmidt, “development of an analytical inverse kinematics for a 5 dof manipulator,” in 2020 21st international conference on research and education in mechatronics (rem), pp. 1–5, 2020. table 7. manipulator torque performance manipulator joint performance undisturbed ocean depth shallow intermediate deep azimuth 1l ω = 22.492 o/s 1l τ = 2.895 n.m 1l ω = 22.492 o/s 1l τ = 11.166 n.m 1l ω = 22.492 o/s 1l τ = 7.468 n.m 1l ω = 22.492 o/s 1l τ = 7.147 n.m elevation 2l ω = 3.749 o/s 2l τ = 803.943 n.m 2l ω = 3.749 o/s 2l τ = 854.261 n.m 2l ω = 3.749 o/s 2l τ = 857.264 n.m 2l ω = 3.749 o/s 2l τ = 856.325 n.m https://mev.lipi.go.id/ https://doi.org/10.1109/rem.2019.8744124 https://doi.org/10.1109/rem.2019.8744124 https://doi.org/10.1109/rem.2019.8744124 https://doi.org/10.1109/rem.2019.8744124 https://dx.doi.org/10.14203/j.mev.2022.v13.1-14 https://dx.doi.org/10.14203/j.mev.2022.v13.1-14 https://dx.doi.org/10.14203/j.mev.2022.v13.1-14 https://dx.doi.org/10.14203/j.mev.2022.v13.1-14 https://dx.doi.org/10.14203/j.mev.2022.v13.1-14 https://doi.org/10.1109/icaee.2017.8255367 https://doi.org/10.1109/icaee.2017.8255367 https://doi.org/10.1109/icaee.2017.8255367 https://doi.org/10.1109/icaee.2017.8255367 https://doi.org/10.1109/tvt.2021.3076870 https://doi.org/10.1109/tvt.2021.3076870 https://doi.org/10.1109/tvt.2021.3076870 https://doi.org/10.1109/tvt.2021.3076870 https://doi.org/10.1109/smc52423.2021.9658909 https://doi.org/10.1109/smc52423.2021.9658909 https://doi.org/10.1109/smc52423.2021.9658909 https://doi.org/10.1109/smc52423.2021.9658909 https://doi.org/10.1109/smc52423.2021.9658909 https://doi.org/10.1109/lra.2019.2896465 https://doi.org/10.1109/lra.2019.2896465 https://doi.org/10.1109/lra.2019.2896465 https://doi.org/10.1109/lra.2019.2896465 https://doi.org/10.1109/humanoids.2018.8624931 https://doi.org/10.1109/humanoids.2018.8624931 https://doi.org/10.1109/humanoids.2018.8624931 https://doi.org/10.1109/humanoids.2018.8624931 https://doi.org/10.1109/humanoids.2018.8624931 https://doi.org/10.1109/iccke.2018.8566243 https://doi.org/10.1109/iccke.2018.8566243 https://doi.org/10.1109/iccke.2018.8566243 https://doi.org/10.1109/iccke.2018.8566243 https://doi.org/10.1109/iccke.2018.8566243 https://doi.org/10.1109/ies53407.2021.9594017 https://doi.org/10.1109/ies53407.2021.9594017 https://doi.org/10.1109/ies53407.2021.9594017 https://doi.org/10.1109/ies53407.2021.9594017 https://doi.org/10.1109/rem49740.2020.9313880 https://doi.org/10.1109/rem49740.2020.9313880 https://doi.org/10.1109/rem49740.2020.9313880 https://doi.org/10.1109/rem49740.2020.9313880 m.l. ramadiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 113-124 124 [11] p. chen, j. long, w. yang, and j. leng, “inverse kinematics solution of underwater manipulator based on jacobi matrix,” in oceans 2021: san diego – porto, pp. 1–4, 2021. [12] m. f. amundsen, j. sverdrup-thygeson, e. kelasidi, and k. y. pettersen, “inverse kinematic control of a free-floating underwater manipulator using the generalized jacobian matrix,” in 2018 european control conference (ecc), pp. 276– 281, 2018. [13] a. s. polydoros, e. boukas, and l. nalpantidis, “online multitarget learning of inverse dynamics models for computedtorque control of compliant manipulators,” in 2017 ieee/rsj international conference on intelligent robots and systems (iros), pp. 4716–4722, 2017. [14] a. awatef and b. h. mouna, “dynamic modeling and inverse dynamic control of mobile robot,” in 2017 international conference on green energy conversion systems (gecs), pp. 1–5, 2017. [15] f. crenna and g. b. rossi, “measurement uncertainty evaluation in biomechanical inverse dynamics analysis,” in 2020 ieee international instrumentation and measurement technology conference (i2mtc), pp. 1–5, 2020. [16] e. farah and l. shaogang, “an efficient approach for manipulator robot dynamics modeling,” in 2018 international conference on computer, control, electrical, and electronics engineering (iccceee), pp. 1–5, 2018. [17] a. müller, “recursive second-order inverse dynamics for serial manipulators,” in 2017 ieee international conference on robotics and automation (icra), pp. 2483–2489, 2017. [18] b. wei, y. li, y. zhang, y. li, and s. shu, “dynamic modeling of mobile manipulator based on floating-like base,” in 2022 ieee 6th information technology and mechatronics engineering conference (itoec), vol. 6, pp. 993–998, 2022. [19] r. szász, m. allenspach, m. han, m. tognon, and r. k. katzschmann, “modeling and control of an omnidirectional micro aerial vehicle equipped with a soft robotic arm,” in 2022 ieee 5th international conference on soft robotics (robosoft), pp. 1–8, 2022. [20] y. cai, s. zheng, w. liu, z. qu, and j. han, “model analysis and modified control method of ship-mounted stewart platforms for wave compensation,” ieee access, vol. 9, pp. 4505–4517, 2021. [21] w. lv, l. tao, and z. ji, “design and control of cable-drive parallel robot with 6-dof active wave compensation,” in 2017 3rd international conference on control, automation and robotics (iccar), pp. 129–133, 2017. [22] x. huang, j. wang, y. xu, y. zhu, t. tang, and f. xu, “dynamic modeling and analysis of wave compensation system based on floating crane in smart port,” in 2018 international symposium in sensing and instrumentation in iot era (issi), pp. 1–5, 2018. [23] y. qian and y. fang, “dynamics analysis of an offshore shipmounted crane subject to sea wave disturbances,” in 2016 12th world congress on intelligent control and automation (wcica), pp. 1251–1256, 2016. [24] e. yazid, a. s. nugraha, h. m. saputra, and rahmat, “dynamics of a ship-mounted two-dof manipulator case: effect of sea state to the manipulator joint torque,” in 2019 ieee international conference on industry 4.0, artificial intelligence, and communications technology (iaict), pp. 1–6, 2019. [25] m. o. ahmed, a. yenduri, and v. j. kurian, “evaluation of the dynamic responses of truss spar platforms for various mooring configurations with damaged lines,” ocean engineering, vol. 123, pp. 411–421, 2016. [26] y. cai, s. zheng, w. liu, z. qu, and j. han, “model analysis and modified control method of ship-mounted stewart platforms for wave compensation,” ieee access, vol. 9, pp. 4505–4517, 2021. [27] j. yue, “kinematic modelling and simulation of learm robot,” in 2022 6th international conference on robotics, control and automation (icrca), pp. 1–6, 2022. [28] e. yazid, r. ristiana, m. mirdanies, r. a. ardiansyah, r. rahmat, and y. sulaeman, “sizing the mechanical and electrical performances of a two-dof manipulator design taking into account pmsm type three-phase ac servo motor,” in 2021 international conference on computer science and engineering (ic2se), vol. 1, pp. 1–9, 2021. [29] s. son, “design of ocean platforms against ringing response,” master of science thesis in mechanical engineering, texas tech university, 2006. [30] p. webb, “introduction to oceanography,” roger williams university, aug. 2021. [accessed: aug. 20, 2022]. [31] e. yazid, m. mirdanie, r. a. ardiansyah, rahmat, r. ristiana, and y. sulaeman, “inverse kinematics model for a ship mounted two-dof manipulator system,” in 2021 ieee ocean engineering technology and innovation conference: ocean observation, technology and innovation in support of ocean decade of science (oetic), pp. 50–56, 2021. [32] r. d. fernandes and r. sundaravadivelu, “hydrodynamic response of floating pontoon for seaplane operation,” in oceans 2022 chennai, pp. 1–10, 2022. https://doi.org/10.23919/oceans44145.2021.9705690 https://doi.org/10.23919/oceans44145.2021.9705690 https://doi.org/10.23919/oceans44145.2021.9705690 https://doi.org/10.23919/ecc.2018.8550525 https://doi.org/10.23919/ecc.2018.8550525 https://doi.org/10.23919/ecc.2018.8550525 https://doi.org/10.23919/ecc.2018.8550525 https://doi.org/10.23919/ecc.2018.8550525 https://doi.org/10.1109/iros.2017.8206344 https://doi.org/10.1109/iros.2017.8206344 https://doi.org/10.1109/iros.2017.8206344 https://doi.org/10.1109/iros.2017.8206344 https://doi.org/10.1109/iros.2017.8206344 https://doi.org/10.1109/gecs.2017.8066236 https://doi.org/10.1109/gecs.2017.8066236 https://doi.org/10.1109/gecs.2017.8066236 https://doi.org/10.1109/gecs.2017.8066236 https://doi.org/10.1109/i2mtc43012.2020.9128954 https://doi.org/10.1109/i2mtc43012.2020.9128954 https://doi.org/10.1109/i2mtc43012.2020.9128954 https://doi.org/10.1109/i2mtc43012.2020.9128954 https://doi.org/10.1109/iccceee.2018.8515879 https://doi.org/10.1109/iccceee.2018.8515879 https://doi.org/10.1109/iccceee.2018.8515879 https://doi.org/10.1109/iccceee.2018.8515879 https://doi.org/10.1109/icra.2017.7989289 https://doi.org/10.1109/icra.2017.7989289 https://doi.org/10.1109/icra.2017.7989289 https://doi.org/10.1109/itoec53115.2022.9734599 https://doi.org/10.1109/itoec53115.2022.9734599 https://doi.org/10.1109/itoec53115.2022.9734599 https://doi.org/10.1109/itoec53115.2022.9734599 https://doi.org/10.1109/robosoft54090.2022.9762161 https://doi.org/10.1109/robosoft54090.2022.9762161 https://doi.org/10.1109/robosoft54090.2022.9762161 https://doi.org/10.1109/robosoft54090.2022.9762161 https://doi.org/10.1109/robosoft54090.2022.9762161 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/iccar.2017.7942673 https://doi.org/10.1109/iccar.2017.7942673 https://doi.org/10.1109/iccar.2017.7942673 https://doi.org/10.1109/iccar.2017.7942673 https://doi.org/10.1109/issi.2018.8538059 https://doi.org/10.1109/issi.2018.8538059 https://doi.org/10.1109/issi.2018.8538059 https://doi.org/10.1109/issi.2018.8538059 https://doi.org/10.1109/issi.2018.8538059 https://doi.org/10.1109/wcica.2016.7578629 https://doi.org/10.1109/wcica.2016.7578629 https://doi.org/10.1109/wcica.2016.7578629 https://doi.org/10.1109/wcica.2016.7578629 https://doi.org/10.1109/iciaict.2019.8784860 https://doi.org/10.1109/iciaict.2019.8784860 https://doi.org/10.1109/iciaict.2019.8784860 https://doi.org/10.1109/iciaict.2019.8784860 https://doi.org/10.1109/iciaict.2019.8784860 https://doi.org/10.1016/j.oceaneng.2016.07.004 https://doi.org/10.1016/j.oceaneng.2016.07.004 https://doi.org/10.1016/j.oceaneng.2016.07.004 https://doi.org/10.1016/j.oceaneng.2016.07.004 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/access.2020.3047063 https://doi.org/10.1109/icrca55033.2022.9828958 https://doi.org/10.1109/icrca55033.2022.9828958 https://doi.org/10.1109/icrca55033.2022.9828958 https://doi.org/10.1109/ic2se52832.2021.9792074 https://doi.org/10.1109/ic2se52832.2021.9792074 https://doi.org/10.1109/ic2se52832.2021.9792074 https://doi.org/10.1109/ic2se52832.2021.9792074 https://doi.org/10.1109/ic2se52832.2021.9792074 https://doi.org/10.1109/ic2se52832.2021.9792074 http://hdl.handle.net/2346/998 http://hdl.handle.net/2346/998 http://hdl.handle.net/2346/998 https://rwu.pressbooks.pub/webboceanography/chapter/10-1-wave-basics/ https://rwu.pressbooks.pub/webboceanography/chapter/10-1-wave-basics/ https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oetic53770.2021.9733723 https://doi.org/10.1109/oceanschennai45887.2022.9775307 https://doi.org/10.1109/oceanschennai45887.2022.9775307 https://doi.org/10.1109/oceanschennai45887.2022.9775307 introduction ii. materials and methods forward kinematics b. inverse dynamics c. ship motions iii. results and discussions conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.94-104 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: r. c. kirana et al., “failure assessment in lithium-ion battery packs in electric vehicles using the failure modes and effects analysis (fmea) approach,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 94-104, july 2023. failure assessment in lithium-ion battery packs in electric vehicles using the failure modes and effects analysis (fmea) approach rizky cahya kirana a, *, nicco avinta purwanto b, nadana ayzah azis b, endra joelianto c, e, sigit puji santosa d, e, bentang arief budiman d, e, le hoa nguyen f, arjon turnip g a instrumentation and control graduate program, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia b faculty of industrial technology, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia c instrumentation and control research group, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia d faculty of mechanical and aerospace engineering, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia e national center for sustainable transportation technology, institut teknologi bandung jalan ganesha 10, bandung 40132, indonesia f faculty of advanced science and technology, university of science and technology, the university of danang 54 nguyen luong bang str., danang city, vietnam g electrical engineering study program, universitas padjajaran jalan raya bandung sumedang km 21 jatinangor, kab. sumedang 45363, indonesia received 21 march 2023; revised 7 july 2023; accepted 9 july 2023; published online 31 july 2023 abstract the use of batteries in electric cars comes with inherent risks. as the crucial component of these vehicles, batteries must possess a highly dependable safety system to ensure the safety of users. to establish such a reliable safety system, a comprehensive analysis of potential battery failures is carried out. this research examines various failure modes and their effects, investigates the causes behind them, and quantifies the associated risks. the failure modes and effect analysis (fmea) method is employed to classify these failures based on priority numbers. by studying 28 accident reports involving electric vehicles, data is collected to identify potential failure modes and evaluate their risks. the results obtained from the fmea assessment are used to propose safety measures, considering the importance of the potential failure modes as indicated by their risk priority number (rpn). the design incorporates safeguards against mechanical stress, external short circuits, and thermal runaway incidents. the findings of this study enhance our understanding of electric vehicle (ev) battery safety and offer valuable insights to ev manufacturers, regulators, and policymakers, aiding them in the development of safer and more reliable electric vehicles. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: failures; safety assessment; failure mode and effect analysis; lithium-ion battery; safety system. i. introduction in recent years, there has been a growing focus on environmental awareness and the decline of fossil fuels. to tackle this problem, one solution that has gained significant attention is the adoption of electric vehicles, which utilize an eco-friendly energy storage system. batteries have emerged as a promising energy source for electric vehicles, with lithium-ion batteries being the preferred option. this choice is attributed to their advantageous features, including lightweight design, compact size, ability to * corresponding author. tel: +62-812-93498517 e-mail address: rizkycahyakirana@gmail.com https://dx.doi.org/10.14203/j.mev.2023.v14.94-104 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.94-104 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2021.v12.22-29&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 95 function across a wide range of temperatures, rapid charging capability, long lifespan, minimal selfdischarge, and absence of hydrogen gas emissions [1]. moreover, the foremost priority in electric vehicles lies in their safety systems. the use of batteries in such vehicles inherently carries certain risks. given that batteries are a crucial element in electric vehicles, it is imperative for them to possess a safety system of utmost dependability to safeguard the users. it is worth noting that while lithium-ion batteries have a slower ignition time compared to fossil fuels, a failure within a battery cell can still generate internal heat, potentially leading to the combustion of the entire battery pack. over the last few years, multiple accidents have resulted from battery malfunctions. a prominent example took place in 2013, involving a tesla model s vehicle in washington dc, usa, which ignited following a collision with metal debris [2]. furthermore, in august 2016, there was another occurrence where a tesla model s vehicle experienced an unexpected fire while undergoing a road test in biarritz, france. this incident unfolded after the car exhibited signs of problems during the charging procedure [3]. given these accidents, there is an urgent need for a thorough examination of potential battery failures in electric vehicles to improve their safety measures. the referenced study [4] provides a comprehensive overview of different types of electric vehicle (ev) drivetrains, discussing their architecture and examining the pros and cons of each variant. however, it does not delve into the safety system of ev batteries. the main objective is to present the latest advancements in ev technology, which are continually evolving. furthermore, the study conducts a comparison of batteries as the primary energy storage solution, considering factors such as energy density, efficiency, specific energy and power, cost, and applicability. the focus of this discussion specifically revolves around the current state of battery technology used in electric vehicles. additionally, it evaluates the efficiency, power density, fault tolerance, dependability, and cost of electric motors, aiming to identify the most suitable motor type for evs. the research also thoroughly examines the future challenges and opportunities associated with the widespread adoption of evs. while government regulations pertaining to evs remain a significant non-technical obstacle, technical challenges include charging time and battery performance. a previous study has already conducted an examination of potential failures in electric vehicles. in 2013, ruddle et al. [5] performed an initial analysis of hazards using fault tree analysis (fta) and failure modes and effects analysis (fmea) specifically on the electric powertrain of fully electric vehicles. their objective was to develop a prognostic health monitoring system. similarly, in 2014, schlasza et al. [6] conducted a review of aging mechanisms in lithium-ion batteries for electric vehicles using fmea methods. in a separate study, hendricks et al. [7] carried out an fmea analysis on battery failures, emphasizing how this process facilitates the implementation of enhanced control strategies for mitigating battery failures. additionally, in 2016, shoults [8] conducted a comprehensive research study as part of their thesis, focusing on design failure modes and effects analysis in the motor system of electric vehicles. this research resulted in a reduction in risk associated with the motor system by implementing recommended measures to address primary risks in future motor system designs and implementations [8]. pahuja and singh [9] utilized fmea to assess the risk priority number (rpn) of electric vehicle inverters and put forth protective measures. similarly, prasad conducted a qualitative risk analysis of failure modes across cell, module, and battery pack levels using fmea. within their study, prasad identified failure modes with high risks, conducted numerical modeling for one of them, and established design guidelines by constructing a failure envelope at the cell and module levels. this envelope aided in determining the level of localized deformation that a given battery can withstand before initiating internal damage, which could potentially result in a short circuit [10]. the main focus of iso 26262:2018 is to address the potential risks associated with the malfunctioning behavior of e/e safety-related systems and their interactions. however, it does not specifically encompass hazards related to electric shock, fire, smoke, heat, radiation, toxicity, flammability, reactivity, corrosion, energy release, and similar hazards, unless these hazards are directly caused by the malfunctioning behavior of e/e safety-related systems [11]. wang et al. [12] present a comprehensive examination of the thermal runaway phenomenon and the associated fire dynamics in single lithiumion battery cells and multi-cell battery packs. they discuss relevant aspects of this phenomenon. similarly, another study [13] focuses on advancements in lithium-ion battery chemistries, different failure modes, methods, and mechanisms, while recommending strategies to mitigate these failures. in 2018, bubbico et al. [14] conducted an extensive analysis of hazardous scenarios for lithium-ion secondary batteries using fmea. additionally, borujerd et al. performed a fuzzyfmea analysis on an immersion-cooled battery pack (icbp) in an electric vehicle [15]. the primary contribution of this paper is to highlight the risks associated with electric vehicle battery systems during vehicle operation based on historical data. the research begins by collecting data on electric vehicle accidents and analyzing their causes and effects on the battery. potential failure modes are identified and an fmea analysis is conducted using the accident data. the paper also addresses the risks of fire and smoke in relation to the battery. a comprehensive analysis of potential battery failures is carried out to establish a highly reliable safety system in electric vehicles. the paper explores various potential failure modes and their effects, examines the causes, and calculates the associated r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 96 risks, prioritizing the failures using the fmea method. the potential failures are analyzed by considering battery usage, the control system, and the sudden braking of electric vehicles. moreover, safety action recommendations based on the fmea analysis are provided. however, it is important to note that this paper's scope is limited to analyzing the operation of the electric vehicle's battery and does not delve into the chemical processes, reactions, or mechanical structure of the battery. the paper can be summarized in the following manner: in section 1, an overview of previous research on electric vehicle battery safety analysis is provided. section 2 explains the methodology utilized in this study. the fmea results and recommendations are presented in section 3. lastly, section 4 provides a summary of the conclusion. ii. materials and methods batteries undergo redox electrochemical reactions to convert the chemical energy stored within their materials into electricity [16][17][18]. in the case of rechargeable batteries, this chemical reaction allows for the process of transforming electrical energy back into chemical energy. lithium, being a reactive material, can give rise to a phenomenon called lithium plating, which poses a significant risk in the form of internal short circuits [19][20][21]. if one battery cell sustains damage, it can generate heat and potentially lead to thermal leakage in the surrounding cells, resulting in damage to the entire battery pack [9]. for electric vehicles, lithium-based batteries are widely utilized, including li-ion, litio, licoo, li-mno2, limn2o4, lifepo4, liso2, li-socl2, and lto. the key components of an electric vehicle include the battery pack, controller, inverter, motor, and switch [4][22][23]. this paper focuses on observing the safety system, which is separate from the primary driver and main controller. figure 1 illustrates the safety system block, which receives inputs from the controllers and the energy management system. the controller and energy management system, in turn, receive inputs from the real-time condition of the battery, converter, inverter, and motor. within the safety system, situation assessment and decision-making processes are conducted. the decisions made involve determining the necessary actions to be taken if an error occurs, posing a threat to the safety of both the system and the users. fmea is a method that serves the following purposes [24]: • detect potential failure modes, their underlying causes, and the resulting impacts on a particular product or procedure. • evaluate the risk associated with the identified failure modes, impacts, and causes, and prioritize concerns to guide corrective actions. • determine and implement corrective measures to address the most critical issues. rpn is a dimensionless metric of a risk attributed to a process or a component. rpn is calculated using three parameters: 1. the severity of failure (sev), 2. the frequency of failure occurrence (occ), and 3. the detection of failure (det). each factor is assessed on a scale of 1-10, allowing for quantitative or qualitative descriptions [5]. the rpn calculation is as equation (1), 𝑅𝑅𝑅 = 𝑆𝑆𝑆 ∗ 𝑂𝑂𝑂 ∗ 𝐷𝑆𝐷 (1) sev criteria, as defined by sae j1739 [25], are provided in table 1. the likelihood of failure figure 1. electric vehicle configuration table 1. severity of effect criteria [25] effect criteria rank hazardous without warning the failure mode compromises safe operation without providing any prior indication. 10 hazardous with warning the failure mode compromises safe operation with prior indication. 9 very high total loss of the main function. 8 high degradation of the main function. 7 moderate loss of secondary function. 6 low loss of secondary function with degradation of comfort. 5 very low the disturbance is seen or heard, with more than 75 % of users aware of the flaw. 4 minor the disturbance is seen or heard, with 50 % of users aware of the flaw. 3 very minor the disturbance is seen or heard, with less than 25 % of users aware of the flaw. 2 none no effect. 1 r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 97 occurrence (occ), according to sae j1739 [25], is presented in table 2. the capability of the existing design to identify the cause of failure (det), sourced from sae j1739 [25], can be found in table 3. the process of conducting the fmea assessment in this paper is illustrated in figure 2. one crucial step in this process is the collection and analysis of historical data on electric vehicle accidents. this study gathered 28 accident reports from various news sources, which are summarized in table 4. the collected data is instrumental in determining the rpn score. due to limited historical data on electric vehicle accidents, the scoring process will be qualitative, based on the perspective of the experts and referencing sae j1739 guidelines. for a failure mode to be included in the shutdown logic, it must have an rpn score equal to or greater than 20 and a severity score equal to or greater than 7. the cutoff value for the rpn score is set at 20 due to the low occurrence score resulting from incomplete historical data. the cutoff value for the severity score is set at 7 based on sae j1739, which considers a severity score of 7 to indicate high damage and main function degradation in the system. table 2. possible failure rates [25] effect criteria rank very high: failure is almost inevitable ≥1 in 2 10 1 in 3 9 high: repeated failures 1 in 8 8 1 in 20 7 moderate: occasional failures 1 in 80 6 1 in 4 x 102 5 1 in 2 x 103 4 low: relatively few failures 1 in 1,5 x 104 3 1 in 1,5 x 105 2 remote: failure is unlikely ≤1 in 1,5 x 106 1 table 3. detection of effect criteria [25] effect criteria rank absolute uncertainty the existing design control lacks the ability to identify a potential cause or mechanism and the resulting failure mode. 10 very remote the current design control has an extremely low probability of detecting a potential cause or mechanism and the resulting failure mode. 9 remote the likelihood of the current design control detecting a potential cause or mechanism and the resulting failure mode is highly unlikely. 8 very low the chances of the current design control detecting a potential cause or mechanism and the resulting failure mode are extremely minimal. 7 low the likelihood of the current design control identifying a potential cause or mechanism and the subsequent failure mode is relatively low. 6 moderate the current design control has a moderate chance of identifying a potential cause or mechanism and the resulting failure mode. 5 moderately high there is a moderately high probability that the current design control will identify a potential cause or mechanism and the resulting failure mode. 4 high there is a high probability that the current design control will identify a potential cause or mechanism and the resulting failure mode. 3 very high there is a highly favorable probability that the current design control will identify a potential cause or mechanism and the resulting failure mode. 2 almost certain it is almost certain that the current design control can identify a potential cause or mechanism and the resulting failure mode. 1 figure 2. ev assessment using fmea flowchart r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 98 iii. results and discussions the performance of a li-ion battery can be affected by various factors, with temperature and working voltage being the two primary parameters that exert the most significant influence among these variables. the battery has a specified operating range for temperature and voltage based on its electrochemical materials. operating the battery outside of this range can lead to reactions such as internal heating (self-heating) and internal short circuits. when a cell experiences internal heating, it can cause a temperature and pressure increase within the battery, which can trigger thermal runaway in other battery cells. this phenomenon has the potential to result in the destruction of all cells. the accidents related to battery incidents are summarized in table 4. a. internal short circuit a battery cell possesses three key characteristics: working voltage, working current, and capacity. the charge and discharge process in li-ion batteries involves an electrochemical conversion of chemicals to electricity and vice versa. it is important to avoid overcharging a battery cell. when overcharging occurs, lithium ions from the cathode continually migrate to the anode, leading to chemical instability. additionally, there is an increase in material resistance at the cathode, causing the incoming energy to be converted into heat, which results in internal heating [26]. during an overcharge of the anode, the copper material undergoes oxidation and dissolves into the electrolyte solution. as the charging process continues, the copper material will redeposit onto the anode. repeated over-discharge can lead to the growth of metal dendrites inside the battery. these dendrites have the ability to penetrate the separator, potentially causing an internal short circuit [20]. excessive electron flow within the cell can result in internal short circuits. these internal short circuits, in turn, cause the battery to heat up internally, potentially leading to thermal runaway. the presence of metal particles within the cell can cause damage, including the formation of metal dendrites due to excessive chemical reactions [27]. b. battery storage and operation at high temperature damage to the battery can occur in the sei layer and/or through electrolyte evaporation at high temperatures. when the sei layer is damaged, typically at temperatures around 120 °c, the anode table 4. electric vehicle accident case data example date location type cause damage source fire or smoke mechanical stress short circuit over heat 17/11/10 oslocopenhagen a future ev operating 1 0 1 0 [29] 01/06/11 chevrolet volt crash testing 1 0 0 0 [30] 01/12/11 us fisker karma component defect 1 1 1 0 [31] 01/05/12 texas fisker karma 1 0 0 0 [32] 01/05/12 byd e6 collision 1 0 1 0 [33] 01/08/12 california fisker karma 1 0 0 1 [34] 01/09/12 dodge ram 1500 plug-in hybrid operating 0 0 0 1 [35] 29/10/12 toyota prius phev flood, submerged in water 1 0 1 0 [36] 01/03/13 mitsubishi i-miev charge-discharge test 1 0 0 0 [37] 01/03/13 outlander p-hev 0 0 0 1 [38] 01/10/13 washington tesla s collision 1 1 0 0 [39] 18/10/13 mexico tesla s collision 1 0 0 0 [40] 06/11/13 tennessee tesla s collision 1 0 0 0 [41] 15/11/13 california tesla s charging 1 0 0 0 [42] 01/09/15 texas nissan leaf 1 0 0 0 [43] 01/01/16 norway tesla s charging 1 0 1 0 [44] 15/08/16 france tesla s 90d test-drive 1 1 0 0 [45] 03/11/16 indianapolis tesla model s collision 1 1 0 0 [46] 25/08/17 california tesla x collision 1 0 0 0 [47] 07/12/17 germany vw e-golf 1 0 0 0 [48] 16/03/18 thailand porsche panamera ehybrid charging 1 0 0 0 [49] 10/05/18 florida tesla model s collision 1 1 0 0 [50] 16/06/18 los angles tesla s operating 1 0 0 0 [51] 22/08/18 new jersey tesla model s collision 1 1 0 0 [52] 10/09/18 poland tesla model s battery overheat 1 1 0 1 [53] 18/12/18 california tesla model s battery overheat 1 0 0 1 [54] 18/02/19 california tesla model x collision 1 1 0 0 [55] 24/02/19 vermont tesla model x collision 1 1 0 0 [56] r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 99 material can function as an electrolyte, leading to the production of explosive compounds. additionally, electrolyte evaporation can cause an increase in pressure within the cell, surpassing the limit of the cell envelope [26]. c. external mechanical disturbance external mechanical interference manifests as external pressure and mechanical stress on the battery cell. instances such as dropping the battery, colliding with other objects, or creating a hole in the casing can trigger chemical reactions within the cell, leading to internal heating. moreover, when lithium ions react with ambient air, an exothermic reaction occurs, releasing heat energy [26]. the regular operation of electric vehicles, including driving on uneven road surfaces, subjects the lithium-ion batteries to external mechanical loads. over time, these loads can lead to mechanical failure in the batteries due to heightened stress and deformation in the electrode materials. as a result, the electrode active materials may lose their ability to store lithium ions, leading to potential short circuits [28]. d. external short circuit during an external short circuit, the two terminals of the battery are connected to a conductor with a resistance of less than 50 mω. in a battery pack consisting of numerous fully charged cells, a short circuit can lead to the flow of high currents. the occurrence of a rapid chemical reaction causes a rise in temperature and pressure within the cell, which can ultimately lead to a cell explosion [26]. figure 3 explains common damages in electric vehicles based on table 4. according to the diagram, fire and smoke damage are related to mechanical stress and short circuits. this aligns with the explanation in [26][28], which states that external mechanical stress can cause the battery to experience an internal short circuit, resulting in internal heating of the battery, as explained in [26]. the data also supports the explanation in [26], which describes the mechanism of battery explosions due to external short circuits. this paper focuses on the effects of electric vehicle operation on the battery, recognizing the importance of batteries during electric vehicle operation. six potential failure modes are identified in this study: 1) mechanical stress on the battery; 2) external short circuit; 3) overcurrent; 4) fire event; 5) thermal event; 6) overdischarge. mechanical stress on the battery, external short circuit, thermal event, and fire event are identified because these failure modes occur in electric vehicle accidents, as indicated in table 4. overcurrent is identified because we are dealing with an electrical system, while overvoltage is not considered since this paper solely focuses on electric vehicle operation and not the charging condition. overdischarge is considered because the battery state of charge (soc) decreases during operation, and the risk of overdischarge is likely. the fmea assessment is provided in table 5. figure 3. electric vehicle damages according to table 4 table 5. fmea assessment potential failure mode potential failure effects sev potential causes occ current process controls det rpn mechanical stress possibly contributing to thermal runaway 10 collision, battery is compressed, punctured, or crushed 2 collison detection, battery pack casing 7 140 fire event fire, toxic gases 10 battery overheating, overpressure 1 temperature sensor 3 30 external short circuit overtemperature or overpressure, cells ruptured 9 grounding failure, motor underload 1 load sensor in motor, underload protection in motor 3 27 overcurrent overtemperature 7 cell under-voltage, external short circuit 1 current monitoring, temperature sensor 3 21 overheat battery aging 7 ev operation, environmental exposure 1 cooling system 2 14 over-discharge cell under-voltage 2 ev operation, poor battery health 1 soc prediction, regenerative braking 2 4 r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 100 according to the explanation in [26][28], mechanical stress can lead to an internal short circuit, which results in excessive electron flow within the cell. this excessive flow generates joule heating and increases the temperature, potentially leading to thermal runaway [26][27]. such an event poses a sudden danger to both the vehicle and its occupants. mechanical stress can occur when the cell is compressed, punctured, or crushed, which is likely to happen in the event of a vehicle collision. based on electric vehicle accident reports published from 2011 to 2019, as described in table 4, collisions are the most common cause of electric vehicle accidents. a significant number of these accidents were attributed to failures in autonomous systems within the vehicle. the accident records indicate that the causes of these failures are still uncertain, and the current process control measures are flawed. if a fully charged multi-cell battery experiences an external short circuit, it can lead to the generation of significant peak currents within individual cells. this, in turn, can result in overheating, overpressure, and the potential release of hazardous fumes or cell rupture [26]. while this failure can compromise the safe operation of the battery, passengers may be alerted to the presence of toxic gas due to its distinct odor. a standard test protocol for simulating an external short circuit involves connecting the terminal of a cell to a conductor with a resistance of less than 50 mω. in an electric vehicle context, an external short circuit can occur when the battery pack is connected to the motor underload. to mitigate the risk of such occurrences, it is advisable to incorporate underload protection in the motor and employ a load sensor to monitor the load and ensure safe operation. as mentioned in [26], an external short circuit can result in overcurrent and overheating in the circuit. however, it is important to note that overcurrent can also be caused by the battery cell being undervolted. when the battery voltage is lower than the normal range, the motor requires a higher current to operate, which can lead to overcurrent. to monitor the vehicle's state and detect such failures, electric vehicles are equipped with current and temperature sensors. these sensors play a crucial role in identifying abnormal conditions. based on the electric car accident reports published from 2011 to 2019, as presented in table 4, fire incidents are the most common type of damage that occurs in electric vehicle accidents. this failure typically arises when the control system fails to prevent it or when the battery cells experience extreme conditions such as over-temperature (above 100 °c) or overpressure. the severity of this failure is heightened by the fact that the passengers are not alerted to the potential danger. during a fire incident, the battery cells can generate gases as a result of electrochemical processes, leading to the build-up of excessive heat and pressure within the cells. to mitigate this risk, it is crucial for the vehicle to be equipped with sensors capable of detecting and monitoring the accumulation of excess heat and pressure within the battery pack. these sensors play a vital role in ensuring the early detection of potentially hazardous conditions and enabling appropriate preventive measures to be taken. batteries have been reported to experience solid electrolyte interphase (sei) layer decomposition in li-ion cells with a positive electrode made of lithiated cobalt oxide, which typically starts at 60 °c [57] and continues up to approximately 120 °c [58]. the extent of this failure depends on the temperature and duration of exposure to such conditions. as a result of this failure, there can be a reduction in battery capacity [26]. to address heat-related concerns, electric vehicles are equipped with cooling systems that regulate the temperature of the battery. these cooling systems play a crucial role in maintaining the optimal operating temperature range of the battery, mitigating the risk of thermal damage, and ensuring the overall performance and longevity of the battery. research in [15] focused on conducting an fmea assessment for the installation and management of problematic parts in an immersioncooled battery pack (icbp). if the battery is completely discharged, there is a possibility of an internal short circuit occurring [59]. during deep discharge, the copper material in the anode may oxidize and eventually dissolve into the electrolyte solution [26]. when the battery is depleted, the voltage level drops and the cell may experience under-voltage. in an electric vehicle, the motor's power is determined by the voltage and current. if the battery voltage is low, the motor will require a higher current to generate power. this can lead to an external short circuit within the system and potentially cause overheating in the battery or motor [26]. to manage the battery's performance, an electric vehicle is equipped with a battery management system (bms). the bms monitors the vehicle condition, provides diagnostics, data collection, and manages communication [15]. in this paper, the safety system is separated from bms, as illustrated in figure 1, following the isa standard of functional safety [59]. some electric vehicles also feature a range extender and regenerative braking, which can provide additional charge to the battery during operation. according to [60], a serial regenerative braking method offers the best opportunity to reduce total energy consumption by up to 15 %. the fault tree analysis is presented in figure 2. based on the diagram, there are five primary events that can lead to the shutdown of an electric vehicle: compressed cell, motor underload, environmental exposure, low state of charge (soc), and grounding failure. when the battery cell undergoes compression, puncture, or crushing, it experiences mechanical stress. an external short circuit occurs when the motor is under load. environmental exposure also contributes to thermal runaway. additionally, a battery with a low soc can cause the cell to be under-voltage, leading to a shutdown. following the information provided in table 6, the top four identified probable failure scenarios would trigger a safety shutdown as the required r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 101 action due to their high severity. additionally, the installation of fuses is recommended for external short circuits and overcurrent situations. according to [14][27], electric vehicle battery systems should be equipped with at least one safety feature, including a fuse. additionally, the national highway traffic safety administration (nhtsa) emphasizes the importance of installing fuses for overcurrent protection. fuses serve as a safeguard against excessive current flow and help prevent damage to the circuitry. it is recommended to have appropriate fuse installations in electric vehicles to ensure the safety and protection of the electrical system [26]. to ensure passenger awareness and safety, a visual warning system on the dashboard and an audible warning will be implemented. the warnings will be prioritized based on the event, with mechanical stress being the highest priority, followed by fire event, external short circuit, overcurrent, overheat, and finally, over-discharge. by providing a warning, the failure mode can have a lower severity score according to sae j1739 guidelines provided in table 1 [25]. in the case of a fire event, the smoke sensor will activate to alert passengers of a potential fire in the battery system. overheat failure will activate the cooling fan to assist the cooling system in managing temperature, and over-discharge failure will be prevented through the implementation of a regenerative braking mechanism that provides extra charge to the battery. this paper utilizes six sensors as input for the shutdown logic, as illustrated in figure 4. the selection of these sensors is based on the basic events identified in the fault tree analysis in figure 5. the pressure sensor and smoke sensor are employed to detect mechanical stress in the battery. pressure detection is a risk reduction measure to prevent a catastrophic failure due to build-up pressure in the battery [14]. the addition of a smoke sensor in this paper is to detect when the battery begins to emit gases as a result of build-up pressure. the load sensor is used to detect motor underload, soc monitoring is implemented to identify a low soc condition, current monitoring is employed to detect current surges resulting from grounding failure, and the temperature sensor is utilized to detect increases in battery temperature due to operation or environmental exposure. the logic of the shutdown system employs and gates to ensure that events are not triggered by false alarms and the shutdown procedure is only activated during real emergencies. for example, during normal operation, the battery may experience mechanical stress, such as vibrations or pressure increases. however, as long as this mechanical stress does not lead to the emission of dangerous smoke from the battery, a shutdown procedure is not necessary, and the existing battery protection control is deemed sufficient. table 6. recommended actions potential failure actions recommended mechanical stress warning, safety shutdown fire event warning, smoke sensor, safety shutdown external short circuit warning, fuse installation, safety shutdown overcurrent warning, fuse installation, safety shutdown overheat warning, turn on the cooling system over-discharge warning, regenerative braking figure 4. shut down logic r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 102 iv. conclusion this paper aimed to investigate the probable failure scenarios in lithium-ion battery packs utilized in electric vehicles. the study explored the potential failure impacts, causes, and current process controls associated with the six identified failure modes. to prioritize these failure modes, the risk priority number (rpn) was calculated for each potential failure mode. based on the fmea analysis, the top four failure modes were addressed through the implementation of a shutdown system, complemented by the installation of fuses. the remaining two failure modes were addressed through a safety alert system and appropriate safety actions. acknowledgements this research was supported in part by the ministry of research, technology and higher education of the republic of indonesia under the postgraduate research scheme, institut teknologi bandung, bandung, indonesia 2019. declarations author contribution r.c. kirana, n.a. purwanto, n.a. azis, e. joelianto, s.p. santosa, b.a. budiman, l.h. nguyen, a. turnip contributed equally as the main contributor to this paper. all authors read and approved the final paper. funding statement this research was partially funded by the indonesian ministry of research, technology, and higher education under wcu program managed by institut teknologi bandung. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] a. h. ranjbar, a. banaei, a. khoobroo, and b. fahimi, “online estimation of state of charge in li-ion batteries using impulse response concept,” ieee trans smart grid, vol. 3, no. 1, pp. 360–367, mar. 2012. [2] j. voelcker, “first tesla model s fire caused by collision with road debris,” green car reports, 2013. (accessed nov. 07, 2022). [3] f. lambert, “tesla says model s fire in france was due to ‘electrical connection improperly tightened’ by a human instead of robots,” electrek, 2016. (accessed nov. 09, 2022). [4] m. r. wahid, b. a. budiman, e. joelianto, and m. aziz, “a review on drive train technologies for passenger electric vehicles,” energies (basel), vol. 14, no. 20, p. 6742, oct. 2021. [5] a. r. ruddle, a. galarza, b. sedano, i. unanue, i. ibarra, and l. low, “safety and failure analysis of electrical powertrain for fully electric vehicles and the development of a prognostic health monitoring system,” in hybrid and electric vehicles conference 2013 (hevc 2013), institution of engineering and technology, 2013, pp. 9.4-9.4. [6] c. schlasza, p. ostertag, d. chrenko, r. kriesten, and d. bouquain, “review on the aging mechanisms in li-ion batteries for electric vehicles based on the fmea method,” in figure 5. fault tree analysis https://doi.org/10.1109/tsg.2011.2169818 https://doi.org/10.1109/tsg.2011.2169818 https://doi.org/10.1109/tsg.2011.2169818 https://doi.org/10.1109/tsg.2011.2169818 https://www.greencarreports.com/news/1087393_first-tesla-model-s-fire-caused-by-collision-with-road-debris https://www.greencarreports.com/news/1087393_first-tesla-model-s-fire-caused-by-collision-with-road-debris https://www.greencarreports.com/news/1087393_first-tesla-model-s-fire-caused-by-collision-with-road-debris https://electrek.co/2016/09/09/tesla-fire-france-electrical-connection-improperly-tightened-human-robot/ https://electrek.co/2016/09/09/tesla-fire-france-electrical-connection-improperly-tightened-human-robot/ https://electrek.co/2016/09/09/tesla-fire-france-electrical-connection-improperly-tightened-human-robot/ https://doi.org/10.3390/en14206742 https://doi.org/10.3390/en14206742 https://doi.org/10.3390/en14206742 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1049/cp.2013.1911 https://doi.org/10.1109/itec.2014.6861811 https://doi.org/10.1109/itec.2014.6861811 https://doi.org/10.1109/itec.2014.6861811 r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 103 2014 ieee transportation electrification conference and expo (itec), ieee, jun. 2014, pp. 1–6. [7] c. hendricks, n. williard, s. mathew, and m. pecht, “a failure modes, mechanisms, and effects analysis (fmmea) of lithiumion batteries,” j power sources, vol. 297, pp. 113–120, nov. 2015. [8] l. w. shoults, “implementation of design failure modes and effects analysis for hybrid vehicle systems,” virginia polytechnic institute and state university, blacksburg, 2016. (accessed nov. 07, 2022). [9] v. singh and g. l. pahuja, “failure modes and effects analysis using fuzzy logic for electric vehicle inverter,” in 2018 3rd ieee international conference on recent trends in electronics, information & communication technology (rteict), ieee, may 2018, pp. 2518–2524. [10] a. n. prasad, “engineering safety analysis of ev li-ion batteries for mini zing auto insurance losses,” massachusetts institute of technology, 2018. (accessed nov. 07, 2022). [11] rohm co and ltd, “iso 26262: functional safety standard for modern road vehicles,” iso 26262 automotive functional safety standard white paper. [12] q. wang, b. mao, s. i. stoliarov, and j. sun, “a review of lithium ion battery failure mechanisms and fire prevention strategies,” prog energy combust sci, vol. 73, pp. 95–131, jul. 2019. [13] m. kaliaperumal et al., “cause and mitigation of lithium-ion battery failure—a review,” materials, vol. 14, no. 19, p. 5676, sep. 2021. [14] r. bubbico, v. greco, and c. menale, “hazardous scenarios identification for li-ion secondary batteries,” saf sci, vol. 108, pp. 72–88, oct. 2018. [15] s. v. n. borujerd et al., “fuzzy logic approach for failure analysis of li-ion battery pack in electric vehicles,” eng fail anal, vol. 149, p. 107233, jul. 2023. [16] m. m. petrov et al., “redox flow batteries: role in modern electric power industry and comparative characteristics of the main types,” russian chemical reviews, vol. 90, no. 6, pp. 677–702, jun. 2021. [17] j. wang, x. he, e. paillard, n. laszczynski, j. li, and s. passerini, “lithiumand manganese-rich oxide cathode materials for high-energy lithium ion batteries,” adv energy mater, vol. 6, no. 21, p. 1600906, nov. 2016. [18] h. yuan, h.-j. peng, j.-q. huang, and q. zhang, “sulfur redox reactions at working interfaces in lithium-sulfur batteries: a perspective,” adv mater interfaces, vol. 6, no. 4, p. 1802046, feb. 2019. [19] x. lin, k. khosravinia, x. hu, j. li, and w. lu, “lithium plating mechanism, detection, and mitigation in lithium-ion batteries,” prog energy combust sci, vol. 87, p. 100953, nov. 2021. [20] g. zhang, x. wei, x. tang, j. zhu, s. chen, and h. dai, “internal short circuit mechanisms, experimental approaches and detection methods of lithium-ion batteries for electric vehicles: a review,” renewable and sustainable energy reviews, vol. 141, p. 110790, may 2021. [21] l. huang et al., “a review of the internal short circuit mechanism in lithium‐ion batteries: inducement, detection and prevention,” int j energy res, vol. 45, no. 11, pp. 15797– 15831, sep. 2021. [22] k. v. singh, h. o. bansal, and d. singh, “a comprehensive review on hybrid electric vehicles: architectures and components,” journal of modern transportation, vol. 27, no. 2, pp. 77–107, jun. 2019. [23] a. stippich, “key components of modular propulsion systems for next generation electric vehicles,” cpss transactions on power electronics and applications, vol. 2, no. 4, pp. 249–258, dec. 2017. [24] c. s. carlson, “understanding and applying the fundamentals of fmea,” 2015 annual reliability and maintainability symposium, 2015. [25] sae, “j1739_202101: potential failure mode and effects analysis (fmea) including design fmea, supplemental fmeamsr, and process fmea,”sae international, 2021. (accessed nov. 07, 2022). [26] d. stephens et al., “lithium-ion battery safety issues for electric and plug-in hybrid vehicles (report no. dot hs 812 418),” washington, dc: national highway traffic safety administration, 2017. [27] j. deng, c. bae, a. denlinger, and t. miller, “electric vehicles batteries: requirements and challenges,” joule, vol. 4, no. 3, pp. 511–515, mar. 2020. [28] w. zhou, “effects of external mechanical loading on stress generation during lithiation in li-ion battery electrodes,” electrochim acta, vol. 185, pp. 28–33, dec. 2015. [29] ritzau, “ferry on the water again in six days at the earliest,” fyens, 2010. (accessed nov. 09, 2022). [30] c. jensen, “chevy volt fire prompts federal investigation into lithium-ion batteries," the new york times, 2011. (accessed nov. 09, 2022). [31] c. jensen, “fisker recalling 239 karma plug-in hybrids for fire hazard." the new york times, 2011. (accessed nov. 09, 2022). [32] a.g. keane, “fisker karma fire in texas garage being probed by nhtsa,” bloomberg, 2018. (accessed nov. 09, 2022). [33] m. milikin, “investigation concludes fire in byd e6 collision caused by electric arcs from short circuit igniting interior materials and part of power battery,”green car congress, 2012. (accessed nov. 09, 2022). [34] d. lavrinc, “another fisker karma goes up in flames,” wired, 2012. (accessed nov. 09, 2022). [35] j. voelcker, “chrysler yanks plug-in hybrid test fleet off roads, will replace batteries,” green car reports, 2012. (accessed nov. 09, 2022). [36] j. garthwaite, “mystery at port newark: why did 17 plug-in cars burn?” the new york times, 2012. (accessed nov. 09, 2022). [37] m. milikin, “mitsubishi reports fire in i-miev battery pack, melting in outlander phev pack,” green car congress, 2018. (accessed nov. 09, 2022). [38] j. jiang, “caught on camera: hybrid electric suv plunges into water at port moody boat launch,” ctv news, 2019. (accessed nov. 09, 2022). [39] c. jensen, “tesla says car fire started in battery,” the new york times, 2013. (accessed nov. 09, 2022). [40] p. george, “another tesla model s caught fire after a crash in mexico,” jalopnik, 2013. (accessed nov. 09, 2022). [41] a. ohnsman and a.g. keane, “tesla’s third model s fire brings call for u.s. inquiry,” bloomberg, 2013. (accessed nov. 09, 2022). [42] e. loveday, “update: tesla spokesperson: model s ‘absolutely was not’ the cause of a garage fire in california,” insideevs, 2013. (accessed nov. 09, 2022). [43] f. lambert, “a nissan leaf caught fire in north texas cause currently unknown,” electrek, 2013. (accessed nov. 09, 2022). [44] k. nygaard, “tesla tok fyr og brant helt ut.” fvn, 2016. (accessed nov. 09, 2022). [45] f. lambert, “rare tesla model s fire following fatal crash in speeding accident.” electrek, 2016. (accessed nov. 09, 2022). [46] a. mendoza, “tesla slams into lake forest garage, severely damaging it and sparking a fire,” orange county register, 2017. (accessed nov. 09, 2022). [47] waz, “feuerwehr löscht brennenden e-golf,” waz online, 2017. (accessed nov. 09, 2022). [48] bangkok post, “porsche catches fire while charging,” bangkok post, 2018. (accessed nov. 09, 2022). [49] f. lambert, “tragic fatal crash in tesla model s goes national because – tesla,” electrek, 2018. (accessed nov. 09, 2022). [50] f. lambert, “tesla model s battery caught on fire ‘without accident’, says owner tesla is investigating,” electrek, 2018. (accessed nov. 09, 2022). [51] f. lambert, “a tesla model s caught on fire on the highway after ‘hitting a component’ that fell off a truck,” electrek, 2018. (accessed nov. 09, 2022). [52] alphastreet, “tesla model s engulfed in fire in poland,” aplhastreet, 2018. (accessed nov. 09, 2022). [53] nbc, “tesla model s catches fire in los gatos, reignites hours later at tow yard,” nbc bay area, 2018. (accessed nov. 09, 2022). [54] d. louie, “fiery tesla model x crash in fremont leaves driver injured,” abc7 san francisco, 2019. (accessed nov. 09, 2022). [55] f. lambert, “tesla model x mysteriously found burning on a frozen lake,” electrek, 2019. (accessed nov. 09, 2022). [56] a. arora, n. k. medora, t. livernois, and j. swart, “safety of lithium-ion batteries for hybrid electric vehicles,” electric and hybrid vehicles: power sources, models, sustainability, infrastructure and the market, pp. 463–491, sep. 2010. [57] t. m. bandhauer, s. garimella, and t. f. fuller, “a critical review of thermal issues in lithium-ion batteries,” j electrochem soc, vol. 158, no. 3, p. r1, jan. 2011. [58] a. sivert et al., “pedagogical study of electric go-karts: technological choices, instrumentations, characteristics, challenge,” wseas transactions on advances in engineering education, vol. 12, pp. 95–104, 2012. (accessed nov. 09, 2022). https://doi.org/10.1109/itec.2014.6861811 https://doi.org/10.1109/itec.2014.6861811 https://doi.org/10.1016/j.jpowsour.2015.07.100 https://doi.org/10.1016/j.jpowsour.2015.07.100 https://doi.org/10.1016/j.jpowsour.2015.07.100 https://doi.org/10.1016/j.jpowsour.2015.07.100 http://hdl.handle.net/10919/71754 http://hdl.handle.net/10919/71754 http://hdl.handle.net/10919/71754 http://hdl.handle.net/10919/71754 https://doi.org/10.1109/rteict42901.2018.9012282 https://doi.org/10.1109/rteict42901.2018.9012282 https://doi.org/10.1109/rteict42901.2018.9012282 https://doi.org/10.1109/rteict42901.2018.9012282 https://doi.org/10.1109/rteict42901.2018.9012282 https://dspace.mit.edu/handle/1721.1/118534 https://dspace.mit.edu/handle/1721.1/118534 https://dspace.mit.edu/handle/1721.1/118534 https://fscdn.rohm.com/en/products/databook/white_paper/iso26262_wp-e.pdf https://fscdn.rohm.com/en/products/databook/white_paper/iso26262_wp-e.pdf https://fscdn.rohm.com/en/products/databook/white_paper/iso26262_wp-e.pdf https://doi.org/10.1016/j.pecs.2019.03.002 https://doi.org/10.1016/j.pecs.2019.03.002 https://doi.org/10.1016/j.pecs.2019.03.002 https://doi.org/10.3390/ma14195676 https://doi.org/10.3390/ma14195676 https://doi.org/10.3390/ma14195676 https://doi.org/10.1016/j.ssci.2018.04.024 https://doi.org/10.1016/j.ssci.2018.04.024 https://doi.org/10.1016/j.ssci.2018.04.024 https://doi.org/10.1016/j.engfailanal.2023.107233 https://doi.org/10.1016/j.engfailanal.2023.107233 https://doi.org/10.1016/j.engfailanal.2023.107233 https://doi.org/10.1070/rcr4987 https://doi.org/10.1070/rcr4987 https://doi.org/10.1070/rcr4987 https://doi.org/10.1070/rcr4987 https://doi.org/10.1002/aenm.201600906 https://doi.org/10.1002/aenm.201600906 https://doi.org/10.1002/aenm.201600906 https://doi.org/10.1002/aenm.201600906 https://doi.org/10.1002/admi.201802046 https://doi.org/10.1002/admi.201802046 https://doi.org/10.1002/admi.201802046 https://doi.org/10.1002/admi.201802046 https://doi.org/10.1016/j.pecs.2021.100953 https://doi.org/10.1016/j.pecs.2021.100953 https://doi.org/10.1016/j.pecs.2021.100953 https://doi.org/10.1016/j.rser.2021.110790 https://doi.org/10.1016/j.rser.2021.110790 https://doi.org/10.1016/j.rser.2021.110790 https://doi.org/10.1016/j.rser.2021.110790 https://doi.org/10.1016/j.rser.2021.110790 https://doi.org/10.1002/er.6920 https://doi.org/10.1002/er.6920 https://doi.org/10.1002/er.6920 https://doi.org/10.1002/er.6920 https://doi.org/10.1007/s40534-019-0184-3 https://doi.org/10.1007/s40534-019-0184-3 https://doi.org/10.1007/s40534-019-0184-3 https://doi.org/10.1007/s40534-019-0184-3 https://doi.org/10.24295/cpsstpea.2017.00023 https://doi.org/10.24295/cpsstpea.2017.00023 https://doi.org/10.24295/cpsstpea.2017.00023 https://doi.org/10.24295/cpsstpea.2017.00023 https://www.studocu.com/it/document/universita-di-bologna/ingegneria-elettronica/2015-rams-fundamentals-of-fmeas/35393797 https://www.studocu.com/it/document/universita-di-bologna/ingegneria-elettronica/2015-rams-fundamentals-of-fmeas/35393797 https://www.studocu.com/it/document/universita-di-bologna/ingegneria-elettronica/2015-rams-fundamentals-of-fmeas/35393797 https://www.sae.org/standards/content/j1739_202101/ https://www.sae.org/standards/content/j1739_202101/ https://www.sae.org/standards/content/j1739_202101/ https://www.sae.org/standards/content/j1739_202101/ https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12848-lithiumionsafetyhybrids_101217-v3-tag.pdf https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12848-lithiumionsafetyhybrids_101217-v3-tag.pdf https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12848-lithiumionsafetyhybrids_101217-v3-tag.pdf https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12848-lithiumionsafetyhybrids_101217-v3-tag.pdf https://doi.org/10.1016/j.joule.2020.01.013 https://doi.org/10.1016/j.joule.2020.01.013 https://doi.org/10.1016/j.joule.2020.01.013 https://doi.org/10.1016/j.electacta.2015.10.097 https://doi.org/10.1016/j.electacta.2015.10.097 https://doi.org/10.1016/j.electacta.2015.10.097 https://fyens.dk/indland/faerge-tidligst-paa-vandet-igen-om-seks-dage https://fyens.dk/indland/faerge-tidligst-paa-vandet-igen-om-seks-dage https://archive.nytimes.com/wheels.blogs.nytimes.com/2011/11/11/chevy-volt-fire-prompts-federal-investigation-into-lithium-ion-batteries/?ref=automobiles https://archive.nytimes.com/wheels.blogs.nytimes.com/2011/11/11/chevy-volt-fire-prompts-federal-investigation-into-lithium-ion-batteries/?ref=automobiles https://archive.nytimes.com/wheels.blogs.nytimes.com/2011/11/11/chevy-volt-fire-prompts-federal-investigation-into-lithium-ion-batteries/?ref=automobiles https://archive.nytimes.com/wheels.blogs.nytimes.com/2011/12/30/fisker-recalling-239-karma-electric-cars-for-fire-hazard/?ref=automobiles https://archive.nytimes.com/wheels.blogs.nytimes.com/2011/12/30/fisker-recalling-239-karma-electric-cars-for-fire-hazard/?ref=automobiles https://www.bloomberg.com/news/articles/2012-05-18/fisker-karma-fire-in-texas-garage-being-probed-by-nhtsa https://www.bloomberg.com/news/articles/2012-05-18/fisker-karma-fire-in-texas-garage-being-probed-by-nhtsa https://www.greencarcongress.com/2012/08/byde6-20120810.html https://www.greencarcongress.com/2012/08/byde6-20120810.html https://www.greencarcongress.com/2012/08/byde6-20120810.html https://www.greencarcongress.com/2012/08/byde6-20120810.html https://www.wired.com/2012/08/fisker-karma-fire-part-deux/ https://www.wired.com/2012/08/fisker-karma-fire-part-deux/ https://www.greencarreports.com/news/1079368_chrysler-yanks-plug-in-hybrid-test-fleet-off-roads-will-replace-batteries https://www.greencarreports.com/news/1079368_chrysler-yanks-plug-in-hybrid-test-fleet-off-roads-will-replace-batteries https://www.greencarreports.com/news/1079368_chrysler-yanks-plug-in-hybrid-test-fleet-off-roads-will-replace-batteries https://archive.nytimes.com/wheels.blogs.nytimes.com/2012/11/02/mystery-at-port-newark-why-did-17-plug-in-cars-burn/?mtrref=en.wikipedia.org&assettype=regiwall https://archive.nytimes.com/wheels.blogs.nytimes.com/2012/11/02/mystery-at-port-newark-why-did-17-plug-in-cars-burn/?mtrref=en.wikipedia.org&assettype=regiwall https://archive.nytimes.com/wheels.blogs.nytimes.com/2012/11/02/mystery-at-port-newark-why-did-17-plug-in-cars-burn/?mtrref=en.wikipedia.org&assettype=regiwall https://www.greencarcongress.com/2013/03/mmc-20130327.html https://www.greencarcongress.com/2013/03/mmc-20130327.html https://www.greencarcongress.com/2013/03/mmc-20130327.html https://bc.ctvnews.ca/caught-on-camera-hybrid-electric-suv-plunges-into-water-at-port-moody-boat-launch-1.4425001 https://bc.ctvnews.ca/caught-on-camera-hybrid-electric-suv-plunges-into-water-at-port-moody-boat-launch-1.4425001 https://bc.ctvnews.ca/caught-on-camera-hybrid-electric-suv-plunges-into-water-at-port-moody-boat-launch-1.4425001 https://archive.nytimes.com/wheels.blogs.nytimes.com/2013/10/02/highway-fire-of-tesla-model-s-included-its-lithium-battery/ https://archive.nytimes.com/wheels.blogs.nytimes.com/2013/10/02/highway-fire-of-tesla-model-s-included-its-lithium-battery/ https://jalopnik.com/another-tesla-model-s-caught-fire-after-a-crash-in-mexi-1453376349 https://jalopnik.com/another-tesla-model-s-caught-fire-after-a-crash-in-mexi-1453376349 https://www.bloomberg.com/news/articles/2013-11-07/tesla-s-third-model-s-fire-brings-call-for-u-s-inquiry?utm_source=website&utm_medium=share&utm_campaign=copy https://www.bloomberg.com/news/articles/2013-11-07/tesla-s-third-model-s-fire-brings-call-for-u-s-inquiry?utm_source=website&utm_medium=share&utm_campaign=copy https://www.bloomberg.com/news/articles/2013-11-07/tesla-s-third-model-s-fire-brings-call-for-u-s-inquiry?utm_source=website&utm_medium=share&utm_campaign=copy https://insideevs.com/news/320286/update-tesla-spokesperson-model-s-absolutely-was-not-the-cause-of-a-garage-fire-in-california/ https://insideevs.com/news/320286/update-tesla-spokesperson-model-s-absolutely-was-not-the-cause-of-a-garage-fire-in-california/ https://insideevs.com/news/320286/update-tesla-spokesperson-model-s-absolutely-was-not-the-cause-of-a-garage-fire-in-california/ https://electrek.co/2015/09/04/a-nissan-leaf-caught-fire-in-north-texas-cause-currently-unknown/ https://electrek.co/2015/09/04/a-nissan-leaf-caught-fire-in-north-texas-cause-currently-unknown/ https://www.fvn.no/nyheter/lokalt/i/4qbeq/tesla-tok-fyr-og-brant-helt-ut https://www.fvn.no/nyheter/lokalt/i/4qbeq/tesla-tok-fyr-og-brant-helt-ut https://electrek.co/2016/11/03/tesla-model-s-fire-following-fatal-crash-speeding-accident-indianapolis/ https://electrek.co/2016/11/03/tesla-model-s-fire-following-fatal-crash-speeding-accident-indianapolis/ https://www.ocregister.com/2017/08/25/tesla-slams-into-lake-forest-garage-severely-damaging-it-and-sparking-a-fire/ https://www.ocregister.com/2017/08/25/tesla-slams-into-lake-forest-garage-severely-damaging-it-and-sparking-a-fire/ https://www.ocregister.com/2017/08/25/tesla-slams-into-lake-forest-garage-severely-damaging-it-and-sparking-a-fire/ https://www.waz-online.de/lokales/gifhorn-lk/sassenburg/feuerwehr-loescht-brennenden-e-golf-emcnqi7xhfw5qkhxoapylw7kmy.html https://www.waz-online.de/lokales/gifhorn-lk/sassenburg/feuerwehr-loescht-brennenden-e-golf-emcnqi7xhfw5qkhxoapylw7kmy.html https://www.bangkokpost.com/thailand/general/1429518/porsche-catches-fire-while-charging https://www.bangkokpost.com/thailand/general/1429518/porsche-catches-fire-while-charging https://electrek.co/2018/05/09/tesla-model-s-fatal-crash-fire-national https://electrek.co/2018/05/09/tesla-model-s-fatal-crash-fire-national https://electrek.co/2018/06/16/tesla-model-s-battery-fire-investigating https://electrek.co/2018/06/16/tesla-model-s-battery-fire-investigating https://electrek.co/2018/06/16/tesla-model-s-battery-fire-investigating https://electrek.co/2018/08/22/tesla-model-s-caught-fire-driving-highway https://electrek.co/2018/08/22/tesla-model-s-caught-fire-driving-highway https://electrek.co/2018/08/22/tesla-model-s-caught-fire-driving-highway https://news.alphastreet.com/tesla-model-s-engulfed-in-fire-in-poland-elon-musk/ https://news.alphastreet.com/tesla-model-s-engulfed-in-fire-in-poland-elon-musk/ https://www.nbcbayarea.com/news/local/tesla-vehicle-catches-fire-in-los-gatos/200148/ https://www.nbcbayarea.com/news/local/tesla-vehicle-catches-fire-in-los-gatos/200148/ https://www.nbcbayarea.com/news/local/tesla-vehicle-catches-fire-in-los-gatos/200148/ https://abc7news.com/paseo-padre-parkway-fremont-tesla-crash-on-car-fire/5143718/ https://abc7news.com/paseo-padre-parkway-fremont-tesla-crash-on-car-fire/5143718/ https://electrek.co/2019/02/26/tesla-model-x-mysterious-burning-fire-frozen-lake/ https://electrek.co/2019/02/26/tesla-model-x-mysterious-burning-fire-frozen-lake/ https://doi.org/10.1016/b978-0-444-53565-8.00018-x https://doi.org/10.1016/b978-0-444-53565-8.00018-x https://doi.org/10.1016/b978-0-444-53565-8.00018-x https://doi.org/10.1016/b978-0-444-53565-8.00018-x https://iopscience.iop.org/article/10.1149/1.3515880 https://iopscience.iop.org/article/10.1149/1.3515880 https://iopscience.iop.org/article/10.1149/1.3515880 https://www.wseas.com/journals/articles.php?id=4347 https://www.wseas.com/journals/articles.php?id=4347 https://www.wseas.com/journals/articles.php?id=4347 https://www.wseas.com/journals/articles.php?id=4347 r.c. kirana et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 94-104 104 [59] international standard of automation, “example implementation of ansi/isa-84.00.01-2004 (iec 61511 mod),” north carolina, dec. 2005. [60] c. f. kusuma et al., “energy management system of electric bus equipped with regenerative braking and range extender,” international journal of automotive technology 2021, vol. 22, no. 6, pp. 1651–1664, nov. 2021. https://webstore.ansi.org/preview-pages/isa/preview_isa+tr84.00.04-2005+part+2.pdf https://webstore.ansi.org/preview-pages/isa/preview_isa+tr84.00.04-2005+part+2.pdf https://webstore.ansi.org/preview-pages/isa/preview_isa+tr84.00.04-2005+part+2.pdf https://doi.org/10.1007/s12239-021-0142-z https://doi.org/10.1007/s12239-021-0142-z https://doi.org/10.1007/s12239-021-0142-z https://doi.org/10.1007/s12239-021-0142-z introduction ii. materials and methods iii. results and discussions internal short circuit b. battery storage and operation at high temperature external mechanical disturbance d. external short circuit iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 35 pe�gemba�ga� sistem ko�trol traksi mobil elektrik berbasis reko�struksi keadaa� kecepata� model roda pratikto 1 , yul yunazwin �azaruddin 1 , edi leksono 1 , zainal abidin 2 1 teknik fisika, fakultas teknologi industri 2 teknik mesin, fakultas teknik mesin dan dirgantara institut teknologi bandung, jl ghanesa 10 bandung 40132, indonesia pratikto@hotmail.co.jp diterima: 1 november 2010; direvisi: 4 november 2010; disetujui: 18 november 2010; terbit online: 24 desember 2010. abstrak pada makalah ini dibahas pengembangan kontrol traksi untuk sebuah mobil elektrik dengan metoda yang dikembangkan berdasarkan rekonstruksi keadaan kecepatan sebuah model kendaraan yang mempunyai kesamaan antara percepatan roda dan badan kendaraannya. pada prinsipnya sebuah kendaraan dapat bergerak maju dengan adanya gaya traksi yang disebabkan adanya gaya gesekan antara roda dan jalan. gaya traksi tersebut akan mengecil bahkan dapat menuju nol ketika jalan licin dan torsi masukan dapat mengakibatkan slip yang besar. sementara slip dapat dikurangi dengan cara mengurangi torsi roda. prinsip dasar yang dikembangkan adalah membandingkan kondisi nyata kendaraan dan model untuk memperoleh nilai torsi yang dapat mengurangi terjadinya slip. pengontrolan dilakukan pada kecepatan roda agar mengikuti nilai referensi yang dihasilkan oleh model kendaraan yang digunakan. nilai torsi masukan pada roda dapat dikontrol dengan menggunakan umpan balik yang diperoleh dari perbedaan kecepatan roda yang dikontrol dan yang dihitung dari model. hasil pengujian menunjukkan bahwa dalam proses pengurangan slip, sinyal respons mempunyai overshoot maksimum 9,8%, rise time 3,1 detik, dan settling time 8 detik. kata kunci: rekonstruksi keadaan kecepatan, kontrol traksi, slip roda, kendaraan referensi. abstract in this paper the development of electric vehicle traction control based on state of speed reconstruction of vehicle model that has the same acceleration condition between tire and chassis is studied. vehicle is accelerated if the friction force takes place between tire and road. however, the traction force decreases even tends to zero on slippery road and torque input produces a large slip. evidently, tire slip can be reduced by decreasing the applied torque to the tire. so the basic principle of the proposed method here compares the real vehicle tire speed condition with the model to determine the torque in order to reduce the slip. tire speed is controlled in order to follow the reference value that is calculated from the model. tire torque input then can be controlled by applying the feedback that is obtained from the difference value of speed between model and real tire. implementation of this method on a real vehicle shows that the control method effectively controls the tire speed of vehicle to follow the reference and reducing the slip. from the experiment the control system performance in reducing slip has the result of 9.8% for maximum overshoot, 3.1 second for rise time, and 8 second for settling time. key words : state of speed reconstruction, traction control, tire slip, reference vehicle. i. pe�dahulua� kendaraan atau mobil merupakan kebutuhan masyarakat modern, dan keamanan dalam berkendaraan adalah konsekuensi yang sangat penting dalam kehidupan. dalam beberapa dekade yang lampau sistem kontrol dinamika kendaraan telah dikembangkan untuk meningkatkan kemudahan dan keamanan dalam berkendaraan. pengontrolan dinamika kendaraan ditujukan untuk menghindarkan perilaku kendaraan yang tak diinginkan dengan cara menerapkan kontrol aktif dan membantu pengendara dalam menjalankan kendaraan. di antaranya adalah antilock breaking systems (abs) yang diterapkan untuk menghindari terjadinya roda terkunci akibat pengereman. ini telah menjadi peralatan yang biasa dalam produksi kendaraan. kontrol traksi juga menjadi populer untuk menghindari penggerak roda mengalami kehilangan cengkraman ketika dalam kondisi percepatan. bertambahnya jumlah mobil mengakibatkan meningkatnya polusi udara terutama di kota kota besar. hal ini disebabkan mobil yang ada hampir semua menggunakan bahan bakar fosil yang diubah menjadi tenaga mekanik dengan cara proses pembakaran. pengembangan sistem kontrol traksi mobil elektrik berbasis rekonstruksi keadaan kecepatan model roda (pratikto, yul yunazwin �azaruddin, edi leksono, zainal abidin) pp.35-42 36 pesatnya jumlah kendaraan menunjukkan tingkat kebutuhan akan kendaraan tersebut tidak dapat dibendung. sementara di pihak lain kebutuhan untuk memelihara lingkungan hidup tidak pula dapat ditunda lagi. sementara itu persediaan sumber energi yang diperoleh dari bahan bakar fosil semakin lama jumlahnya semakin menyusut [1], sehingga diperlukan sumber energi pengganti dalam mendukung transportasi. sisi lain dalam permasalahan transportasi adalah kebutuhan peningkatan kenyamanan, jaminan keselamatan, dan ketertiban, dimana hal ini menjadi penting dan harus segera dicapai pada kondisi arus mobilitas yang sangat tinggi seperti sekarang ini. sehubungan dengan faktor keselamatan ini sebuah sistem abs dapat dimanfaatkan agar kendaraan dapat secepat mungkin berhenti dengan aman[2]. sebuah sistem kendaraan yang dikenal dengan sebutan mobil elektrik dapat menjadi alternatif yang cocok untuk dipilih. hal ini tidak lain karena mobil elektrik memenuhi kriteria sebagai alat transportasi masa depan yang ramah lingkungan, efisien, tenang (kebisingan rendah), nyaman, terpercaya dari segi keselamatan penumpang dalam mobil maupun dalam mobil lain yang bersama sama dalam satu komunitas kendaraan. sekarang ini mobil elektrik dengan fuel cell, dan kendaraan hibrida telah berkembang sangat cepat sebagai solusi terhadap permasalahan energi dan lingkungan. sebuah mobil elektrik bergerak dengan memanfaatkan pola kerja motor elektrik yang mempunyai karakteristik merespon dengan cepat melebihi kendaraan bermesin bakar internal (internal combustion engine) [3]. sehingga kecepatan sebuah mobil elektrik sangat responsif terhadap pijakan gas yang secara elektrik mengatur arus atau tegangan yang menentukan kecepatan motor roda mobil elektrik tersebut. pada kondisi jalan yang licin, gerak kecepatan putar roda tidak dapat diikuti oleh kecepatan gerak mobil secara keseluruhan. akibatnya terjadi slip atau perbedaan kecepatan roda dan kendaraan yang makin membesar bila torsi yang diberikan terus bertambah. hal ini akan menyebabkan kendaraan tersebut tidak terkendali dengan baik sehingga jaminan keselamatan penumpang bisa terancam. selain itu, bila slip yang tak terkendali terjadi, pemakaian energi untuk menghasilkan gerak tidak seluruhnya dapat dimanfaatkan secara baik sehingga menimbulkan pemborosan. terkait dengan respon yang cepat tersebut, mobil elektrik juga mempunyai potensi yang menarik dari sudut pandang teknik kontrol. ini berarti bahwa penerapan motor elektrik sebagai penggerak pada mobil juga memberi peluang suatu penerapan sistem kontrol yang canggih, terkait dengan gerak roda, sehingga dapat dengan cepat dan responsif menanggulangi adanya gangguan gerak roda. sistem kontrol yang canggih dapat diciptakan baik secara menyeluruh ataupun secara individual pada setiap rodanya. gerak mobil secara menyeluruh merupakan permasalahan yang kompleks. sebagai fundasi gerak, dinamika pada arah longitudinal sangat penting untuk dikaji. sehubungan dengan hal tersebut, kontrol gerak longitudinal terus menerus dikembangkan. kontrol traksi secara mendasar dikaitkan dengan gerak kendaraan pada arah longitudinal dengan variabel yang dikontrol adalah kecepatan, baik dalam arti kecepatan roda atau kecepatan kendaraan. salah satu permasalahan yang sering dikaji pada pengontrolan kecepatan sebuah kendaraan dalam arah longitudinal adalah justru menentukan nilai kecepatan arah longitudinal itu sendiri, maka beberapa metode dikembangkan untuk ini seperti yang dilakukan oleh allotta dkk. [4], alvarez dkk. [5], dan tanelli dkk. [6]. akan tetapi pengontrolan gerak kendaraan berbasis kecepatan tidak selalu membutuhkan nilai besaran kecepatan kendaraan sebenarnya, melainkan nilai kecepatan roda atau nilai kecepatan kendaraan yang diestimasi berdasarkan nilai kecepatan roda [4]. kontrol traksi kendaraan dapat juga dilakukan berbasis pada besaran rasio slip roda. pengontrolan rasio slip merupakan sebuah problema mendasar dari kontrol traksi [7]. sistem kontrol anti slip penting untuk diterapkan demi mempertahankan efektifitas gerak roda, kestabilan gerak kendaraan dan penghematan energi yang digunakan pada mobil elektrik. pemakaian energi yang tersimpan pada batere merupakan hal yang harus mendapatkan perhatian khusus mengingat waktu pengisian batere belum dapat dilakukan dalam waktu yang singkat. dejun yin [8] melakukan penelitian untuk mendapatkan suatu metode pengontrolan yang didasarkan pada torsi maksimum yang diizinkan agar slip dapat dibatasi. torsi maksimum ditentukan dengan mengabaikan adanya beberapa resistansi gerak, antara lain resistansi gerak roda dan hembusan udara yang dialami kendaraan. pada makalah ini pokok masalah yang akan dipecahkan adalah membangun kontrol traksi yang sekaligus dapat mengurangi slip yang mungkin terjadi pada sebuah roda. metode yang diungkapkan ditujukan untuk memperoleh torsi maksimum dengan cara membandingkannya journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 37 dengan model kendaraan yang mempunyai kesamaan antara kondisi percepatan roda dan badan kendaraan. metode yang diusulkan ini dikembangkan dengan mendefinisikan keadaan rekonstruksi kecepatan roda kendaraan model untuk membangun sistem kontrol sehingga dinamika mobil dikontrol dengan mengamati perbedaan gerak roda antara mobil sebenarnya dan mobil model. ii. metodologi pe�elitia� penelitian dilakukan dengan melakukan kajian teoritis mengenai pengembangan metode kontrol yang digunakan. hasil kajian ini akan diverifikasi melalui eksperimen. metode yang dikembangkan merupakan kontrol traksi berbasis rekonstruksi kecepatan model kendaraan tanpa slip untuk sebuah mobil elektrik. sistem kontrol yang diperoleh diharapkan mempunyai kemampuan untuk mengurangi slip yang terjadi pada roda. dalam pengembangan, sebuah asas yang dikenal dengan prinsip state feedback diterapkan pada kesalahan penjejakan keadaan kecepatan. a. model kendaraan dan dinamika roda persamaan gerak kendaraan roda empat dapat diturunkan dari hukum newton. gambar 1 menunjukkan besaran-besaran yang terlibat pada gerak kendaraan dalam arah longitudinal. kesetimbangan gaya sepanjang sumbu longitudinal � kendaraan dinyatakan dengan persamaan [9]. ��� = ��� + �� − ��� − ��� − �� − � � ��� � (1) dengan ��� , �� , ��� , ��� , �� , �, � dan � masing masing adalah gaya longitudinal roda depan, gaya longitudinal roda belakang, gaya gesek longitudinal ekivalen udara, gaya resistansi akibat putaran roda depan, gaya resistansi akibat putaran roda belakang, massa kendaraan, percepatan gravitasi, dan sudut kemiringan jalan. gambar 1. arah gerak longitudinal [9]. persamaan di atas dapat disederhanakan penulisannya menjadi persamaan berikut. ��� = � − � (2) dengan � = ��� + �� (3) dan � = ��� + ��� + �� + � � ��� � (4) sementara itu gerak putar sebuah roda dinyatakan dengan persamaan berikut: ��� = � − �� (5) dengan �, � , � , � , dan � masing masing adalah momen inersia roda, kecepatan sudut roda, torsi pemutar roda, jari jari efektif roda dan gaya yang bekerja pada roda. besarnya gaya yang terjadi pada roda dapat dihitung berdasarkan magic formula pacejka atau dengan model dugoff [9]. besar gaya � bergantung pada nilai koefisien gesekan antara roda dan jalan � . koefisien ini sangat menentukan terjadinya slip pada roda [3]. b. pengembangan metode kontrol dalam sub bab ini akan dibahas pengembangan metode kontrol traksi berbasis rekonstruksi kecepatan model kendaraan tanpa slip. pengembangan sistem kontrol didasarkan pada sebuah prinsip yang dapat dijelaskan sebagai berikut. sebuah roda kendaraan nyata bila dibandingkan dengan modelnya secara diagram blok dapat digambarkan seperti yang diperlihatkan pada gambar 2. gambar 2. sistem roda dan referensi model. pada kondisi tanpa slip nilai � = �� , � = 0, dan � = �� dengan �� adalah torsi maksimum ketika tidak terjadi slip. dengan kata lain bila � > �� ataupun � < �� , maka sebuah pengontrol harus dipasang agar torsi input pada roda kembali pada kondisi maksimum sehingga slip tidak terjadi. plant (roda) model (referensi) � _ �� � � �� ��� + + + pengembangan sistem kontrol traksi mobil elektrik berbasis rekonstruksi keadaan kecepatan model roda (pratikto, yul yunazwin �azaruddin, edi leksono, zainal abidin) pp.35-42 38 bila ω, j, dan r masing masing adalah kecepatan sudut, momen inersia dan jari-jari roda, keadaan roda sistem kendaraan referensi dapat ditulis dengan persamaan �� � = "#$ %# & (6) ��� = '�� = %# � (7) dengan '� adalah kecepatan kendaraan referensi. sebuah keadaan (� dapat didefinisikan sebagai (�� = �� � − )�# (8) sehingga (�� = "# & − ��� ( + & + + � ,) (9) dan �� � = + &. �� + � , &. (�� (10) rekonstruksi dari �� didefinisikan sebagai �/� , dengan pernyataan bahwa �/� � = + &. �� + � , &. (�� + 0�(�� − �/� ) (11) dan keadaan roda sistem dapat ditulis dengan persamaan �� = "$ %& (12) jika dengan sistem kontrolan yang dapat merekonstruksi keadaan kecepatan model, yakni �� = �/� � (13) maka � = &&. �� + &� , &. (�� + 0� � (14) dengan � = �� − � (15) dan �1 = � + ��2 (16) suatu strategi kontrol dapat dikembangkan dengan menentukan persyaratan pada model, yakni dengan (�� = 0 (17) maka � = &&. �� + �0� � (18) �� = "#&. + $ % & + �0� � (19) sehingga �� = −�0� � + % & (20) bila �� konvergen ke �� � = "# &. (21) diperoleh hubungan % & = �0� � (22) sistem kontrol yang diperoleh diperlihatkan pada gambar 3. untuk suatu kondisi jalan dengan gaya gesekan yang dialami oleh mobil elektrik yang dikontrol sebesar f, dapat diperoleh kesalahan keadaan sebesar �(3) pada �� = 0, gambar 3. struktur sistem dengan umpan balik kesalahan. dengan hanya memperhatikan variabel keadaan kecepatan sudut roda � sistem kontrol kendaraan diperlihatkan oleh diagram blok pada gambar 4. nilai torsi maksimum yang dapat diberikan pada roda agar tidak terjadi slip dapat diperoleh dengan cara sebagai berikut. roda model roda (referensi) � _ �� � �� �� ��� �0� + + + journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 39 gambar 4. struktur sistem kontrol traksi berbasis model kendaraan tanpa slip. substitusi persamaan (2) ke (5) yang memberikan (� = "& − �(� − �)( + & + + � ,) (23) untuk (� = 0, � = �� ���� = 4 & � , + 16 �(� − �) (24) torsi maksimum tanpa slip ���� dengan mengabaikan adanya resistansi roda dan hembusan angin adalah ���� = ( & � , + 1)�� (25) yin dan hori [8] mendefinisikan ���� dengan ���� = ( & 7� , + 1)�� (26) α adalah faktor relaksasi yang merupakan parameter desain pengontrol yang diperkenalkan. secara umum kontrol traksi dapat dirumuskan berdasarkan skema kontrol kecepatan. bila setidaknya terdapat sebuah pengontrol proporsional dengan gain 08 telah ada pada suatu kendaraan maka struktur sistem kendaraan menjadi berbentuk seperti yang diperlihatkan pada gambar 5. gambar 5. struktur sistem kendaraan berpengontrol proporsional. dengan struktur tersebut model mobil referensi dan mobil yang dikontrol dapat dinyatakan dengan persamaan (27) dan persamaan (28). �� � = 9� ��(3) + :� �; (3) (27) �� = 9�(3) + :<(3) + =(3) (28) dengan parameter 9 = −08 + & (29) : = 08 + & (30) dan = = − +& �� (31) kendaraan atau mobil referensi didefinisikan mempunyai struktur seperti diperlihatkan pada gambar 6. gambar 6. struktur sistem kendaraan referensi. >; (�) dan >� (�) masing-masing adalah transformasi laplace dari �; (3) dan �� (3) . dengan demikian diperoleh 9� = − ? (� ,@&) (32) :� = [b@?)c] (� ,@&) (33) dalam persamaan di atas 0 , e , dan '; adalah parameter perancangan pengontrol. struktur kontrol didasarkan pada perolehan kesalahan penjejakan memenuhi persamaan (34) sebagai perluasan dari persamaan (20). �� = (9 − �0� )�(3) − =(�, 3) (34) dengan ini diperoleh bahwa <(3) = 0 �; (3) + 0� ��(3) + 0� [�� (3) − �(3)] (35) 0 = &[b@?)c] bf(� ,@&) (36) 0� = (− &? bg (� ,@&) + 1) (37) 1 �(��2 + �) � >� (�) e '; >; (�) >;) (�) − + + + 0 9 < � 1 � : + + + = �� kendaraan nyata �0� model kendaraan tanpa slip � + �� + + pengembangan sistem kontrol traksi mobil elektrik berbasis rekonstruksi keadaan kecepatan model roda (pratikto, yul yunazwin �azaruddin, edi leksono, zainal abidin) pp.35-42 40 dan 0� ditentukan berdasarkan tingkat kesalahan penjejakan yang diinginkan. secara diagram struktur kontrol yang dihasilkan diperlihatkan pada gambar 7. gambar 7. struktur kontrol traksi berbasis rekonstruksi keadaan kecepatan. bentuk persamaan (27) dan persamaan (28) dapat diterapkan pada kasus diskrit, dengan diskritisasi dapat diperoleh bentuk berikut. �� � (h + 1) = 9� �� (h) + :� �; (h) (38) �� (h + 1) = 9�(h) + :<(h) + =(h) (39) iii. hasil da� diskusi metode kontrol yang diusulkan diterapkan pada eksperimen untuk mengontrol roda penggerak kiri dan kanan mobil elektrik mini sebagaimana diperlihatkan pada gambar 8 dengan momen inersia roda penggerak 0.37 kgm 2 dan massa total 200 kg. gambar 8. mobil elektrik mini. sistem kontrol diuji dalam beberapa kondisi. pertama untuk mengontrol kecepatan roda saja (roda dijalankan bebas tanpa menyentuh jalan) dengan hasil yang diperlihatkan pada gambar 9 dan gambar 10. gambar 9. respons kecepatan roda tanpa pengontrol. gambar 10. respons kecepatan roda dengan pengontrol. kedua, sistem kontrol diterapkan pada kendaraan dalam kondisi berjalan. gambar 11 memperlihatkan respon kecepatan roda tanpa pengontrol dibandingkan dengan kecepatan roda referensi. gambar 12 memperlihatkan respon kecepatan roda setelah pengontrol dijalankan. gambar 11. respon kecepatan roda ketika mobil berjalan tanpa pengontrol. gambar 9 sampai degan gambar 12 tersebut memperlihatkan bahwa sistem kontrol dapat bekerja secara efektif untuk mengatur kecepatan roda agar mengikuti nilai kecepatan referensi. mobil elektrik 0� � �; + + + referensi model (referensi) ��,'� 0� � �/,'p �� + 0 − < journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 41 gambar 12. respon kecepatan roda ketika mobil berjalan dengan pengontrol. ketiga, eksperimen dilakukan dengan melewatkan satu roda penggerak pada lintasan yang di buat lebih licin. lintasan licin ini dibangun dengan memberikan sabun pada permukaan kertas yang halus. gambar 13 berikut menunjukkan lintasan licin yang di gunakan untuk menguji performansi strategi kontrol. gambar 13. lintasan licin. gambar 14. roda tanpa pengontrol mengalami slip. grafik pada gambar 14 dan gambar 15 menunjukkan hasil yang diperoleh dari data kondisi kecepatan roda belakang sebelah kiri ketika slip terjadi pada lintasan licin yang telah dibuat. gambar 15. pengontrol dapat mengurangi terjadinya slip roda. hasil eksperimen di atas menunjukkan bahwa implementasi pengontrolan traksi berbasis keadaan kecepatan model roda dapat mengurangi terjadinya slip secara efektif. dari gambar 15 diketahui bahwa performa pengontrolan dalam mengurangi slip menunjukkan nilai overshoot maksimum diperoleh 9,8%, rise time 3,1 detik, settling time 8 detik dan nilai kesalahan keadaan rata rata 7%. iv. kesimpula� kesimpulan yang dapat diperoleh dari pembahasan dan kegiatan eksperimen adalah: • slip yang terjadi pada kendaraan dapat di kurangi dengan mengurangi torsi masukan pada roda. • agar slip yang terjadi minimum maka torsi masukan pada roda tidak lebih dari besarnya nilai torsi maksimum tertentu. • hasil pengujian menunjukkan bahwa dalam proses pengurangan slip, sinyal respon mempunyai overshoot maksimum 9,8%, rise time 3,1 detik, dan settling time 8 detik. daftar pustaka [1] jonasson k., “control of hybrid electric vehicles with diesel engines,” media-tryck, lund university, 2005, isbn 91-8893438-1. [2] lennon, william k. and kevin m., passino, “intelligent control for brake systems”, ieee transactions on control systems technology, vol. 7, no. 2, march 1999 [3] fujimoto, h., saito t. and noguchi t., “motion stabilization control of electric vehicle under snowy conditions based on yaw-moment observer”, ieee international workshop on advanced motion control (amc2004), pp. 35-40, 2004. pengembangan sistem kontrol traksi mobil elektrik berbasis rekonstruksi keadaan kecepatan model roda (pratikto, yul yunazwin �azaruddin, edi leksono, zainal abidin) pp.35-42 42 [4] allotta, b., colla, v. and malvezzi, m., “train position and speed estimation using wheel velocity measurements”, proceedings of the institution of mechanical engineers, part f: journal of rail and rapid transit publisher professional engineering publishing, 207, 2002. [5] alvarez, l., et al., “dynamic friction model-based tire-road friction estimation and emergency braking control”, journal of dynamic systems, measurement, and control, volume 127, pp. 22, 2005. [6] tanelli, m., savaresi, s.m. and cantoni, c., “longitudinal vehicle speed estimation for traction and braking control systems, computer aided control system design”, 2006 ieee international conference on control applications, 2006 ieee international symposium on intelligent control, 2006. [7] zheng, k., et al., “a design approach for observer-based robust traction control with pmsm”, sice-icase international joint conferenc, 2006. [8] yin, d. and hori, y., “a novel traction control without chassis velocity for electric vehicles”, evs24 stavanger, norway, may 13-16, 2009. [9] rajamani, r., “vehicle dynamics and control”, springer, 2006. microsoft word vol.01_no.1_v3 journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 27 ocean current energy conversion system in wallacea region using variable speed control approach aditya sukma nugraha, estiko rijanto research center for electrical power and mechatronics, indonesian institute of sciences komplek lipi, jl. cisitu no.21/154d, bandung 40135, indonesia adit003@lipi.go.id; estiko.rijanto@lipi.go.id diterima: 31 mei 2010; direvisi: 26 agustus 2010; disetujui: 30 september 2010; terbit online: 10 oktober 2010. abstrak ocean current energy conversion system (ocecs) merupakan salah satu sumber energi ramah lingkungan yang menjanjikan di bumi ini. data sirkulasi thermohaline menunjukkan indikasi bahwa kawasan wallacea memiliki potensi sumber energi arus laut. tujuan makalah ini adalah untuk mengusulkan penelitian dan pengembangan ocecs yang akan dipasang di kawasan wallacea. pertama, pada makalah ini diulas empat macam sistem konversi energi dari lautan. keunggulan dan kekurangan masing-masing sistem konversi dibandingkan. kedua, diuraikan potensi ocecs di kawasan wallacea. ketiga, beberapa tipe turbin yang dapat digunakan untuk ocecs diulas dan kemudian dipilih tipe turbin yang cocok diaplikasikan di kawasan wallacea. keempat, diusulkan strategi pengendalian yang digunakan pada ocecs tersebut. dari hasil kerja yang dilaporkan pada makalah ini dapat diambil kesimpulan bahwa adalah tepat memilih tipe turbin axial flow untuk ocecs yang akan dipasang di kawasan wallacea, dan bahwa untuk memaksimalkan konversi energi tersebut maka dipilih pendekatan kendali kecepatan bervariasi bersama-sama dengan kendali mekanisme untuk menggerakkan turbin pada arah vertikal dan menggerakkan turbin pada arah yaw. kata kunci: arus laut, konversi energi, daerah wallacea, kendali kecepatan bervariasi, sirkulasi thermohaline. abstract ocean current energy conversion system (ocecs) is a promising green energy resource in this globe. the thermohaline circulation data indicates that the wallacea region has the potential of ocean current energy resources. this paper is aimed to propose research and development of ocecss to be implemented in the wallacea region. firstly, four types of green energy conversion systems extracted from ocean are reviewed. their advantages and disadvantages are discussed. secondly, the potential of ocecs in the wallacea region is described. third, many types of turbines used for ocecs are reviewed and the turbine type for ocecs is selected to be implemented in the wallacea region. fourth, control strategy is proposed. from the work reported in this paper it is concluded that it is appropriate to implement ocecss using axial flow water turbines in the wallacea region, and that to maximize energy conversion variable speed control approach is selected together with control of mechanism to move the turbine vertically as well as to rotate the turbine in yaw direction. keywords: ocean current, energy conversion, wallacea region, variable speed control, thermohaline circulation. i. introduction wallacea region is important because of at least three reasons: (1) it is historically recognized named after the publication of wallace’s paper in london, july 1st, 1858 entitled “on the tendency of varieties to depart indefinitely from the original type” [1]; (2) it is a unique region with its unique biodiversity and unique geographical characteristics [2]; (3) it is now categorized as being under developed eastern indonesia from the point of view of national development. at at the closing ceremony of the visit from prof. dr. bruce alberts, the u.s. special envoy for science and technology to indonesia, the wallacea young scientists forum was declared in ternate on may 15th, 2010. prior to this declaration, three commissions had been established in this forum. those are: (1) life quality and food, (2) bio diversity, and (3) green energy and environment [3]. in the commission of green energy and environment some matters concerning green energy resources and environment protection were discussed. this paper is written as a follow up of the discussion in the commission of green energy and environment. although there are many green energy potentials at the wallacea region, this paper focus on energy resources from ocean. ocean current energy conversion system in wallacea region using variable speed control approach (aditya sukma nugraha, estiko rijanto) pp. 27-34 28 presently, there are four types of green energy based on renewable ocean’s energy that are becoming promising for future use those are: tidal energy, wave energy, ocean thermal energy, and ocean current energy [4]. tidal energy is intermittent source of energy because only provides power when the tide is actually moving in or out, yet it is totally predictable and produces electricity reliably. offshore turbines and vertical-axis turbine are not too expensive to build and neither to maintain. furthermore, their installations do not give large environmental impact. tidal turbines provide a larger average power than either wind or wave devices for a given maximum capacity, and they also have higher duty cycle (50 %) than wave turbines (25 %). however, damming estuaries are very expensive to build, and change the environment so they produce negative impact on estuarine ecosystems. for this reason, it is difficult to find suitable sites for tidal barrages. wave energy depends on the waves to produce power, so it needs to be extracted in a suitable site where waves are consistently can produce a great deal of energy. shore based wave turbines requires massive concrete constructions on coastlines which may destroy visual landscape. meanwhile, offshore wind and wave power farms are unpredictable and unreliable energy sources that are subject to extreme weather conditions. ocean thermal energy conversion (otec) has many different applications such as water desalination, and it is able to produce both heat and electricity. it has low thermal efficiency because the temperature difference is small (10 to 25°c), so that energy extraction is difficult and expensive. it requires extremely high initial investment and huge civil construction. ocean current energy is particularly promising as it is available on frequent, regular, predictable schedule. there is little danger to marine life due to the slow rotation speed. the objective of this paper is to report preliminary results and to propose research and development of ocecs (ocean current energy conversion system) to be implemented in the wallacea region. ii. methodology in order to achieve the above objective, in this paper the following procedure has been carried out: a. literature survey concerning ocean current potential in wallacea region. b. literature survey concerning ocean current energy conversion system. a. potential in wallacea region wallacea is a biogeographical designation for a group of indonesian islands separated by deep water straits from the asian and australian continental shelves. wallacea is islands within red area shown in figure 1. the islands of wallacea lie between sundaland (the malay peninsula, sumatra, borneo, java, and bali) to the west, and near oceania including australia and new guinea to the south and east. provinces and major islands in wallacea are: sulawesi (6 provinces), north maluku (including halmahera), maluku (excluding aru islands), west nusa tenggara (lombok, sumbawa), east nusa tenggara (including komodo, flores, sumba, west timor), and east timor (independent) [5]. figure 1. wallacea region wallacea region is a significant location for doing research on biodiversity and geology. biodiversity conservation in this region becomes an important issue [2]. however, many places in the wallacea region still have problems of energy (electricity) availability. for example, the electricity utility company which is responsible for the provinces of maluku and north maluku covers area of 85728 km2 with the area of terrestrial is only 8.573 km2 or 10%. diesel electrical power plants have been the only sources of electricity [6]. in the ambon electric utility system there exist diesel electrical power plants with the installed capacity of 55072 kw, but they can only produce electricity of 17900 kw resulting in electricity deficit of 17100 kw at night and 9100 kw in the day. most of these diesel electrical power plants are in not good condition [7]. at the seram island 19 villages have not been receiving electricity in the day for 3 years, electricity is only available at night [8]. the balance between development activities to achieve mdg (milenium development goal) and the natural resources conservation becomes challenging. in this context, providing electricity based on green renewable energy is welcomed. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 29 figure 2 shows global ocean current called thermohaline circulation [9], [10]. the ocean current phenomenon is due to radiation of the sun, coriolis effect because of the rotation of the planet, and density gradient of the sea water. the radiation of the sun and the coriolis effect yields wind current which moves the surface water of the seas (it is the water between 0 and 400 m of depth) causing ocean surface current denoted by red line. on the other hand, the cold water from the poles tends to go deeply (the water of the depth more than 400 m) to the equator while the warm water from the equator tends to go to the poles by the surface. figure 2. thermohaline circulation [9], [10]. from the thermohaline circulation shown in figure 2, it is clear that the wallacea region is passed by the ocean surface current which is denoted by red line. the ocean surface current flows from the pacific ocean into the hindia ocean crossing the wallacea region. this becomes a preliminary indication of the potential for building electrical power plants based on ocean current. research on measurement of ocean current in the wallacea region is necessary to be conducted in order to obtain detail ocean current energy potential mapping. with the above thermohaline circulation as the first basis, research on design of electrical power plants using ocean current energy in the wallacea region is valuable. in the context of national capacity building, it is preferable to conduct research and development of such power plants using as much as national capabilities in cooperation with scientists and engineers from advanced countries. b. ocean current energy conversion an ocean current electrical power plant is to convert the kinetic energy of the ocean currents to electricity. the amount of the ocean water moves the rotor, and in turn it rotates a generator to produce the electricity. the principle of the ocean current energy conversion system (ocecs) is the same as the wind energy conversion system (wecs). the betz principle can be used to derive the power extracted by the turbine as follows [11]. ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ = 3 2 1 avcp p ρ (1) the value of power coefficient pc depends on turbine blade construction, its aerodynamics parameter and ocean water current speed and direction. an ocecs should be designed in order to fulfill the following objectives: maximizing efficiency, being well fixed to the seabed, easy maintenance and operation, environmentally benign, and minimizing costs. many researchers, engineers, and companies have been conducting research and development of many types of prototypes to fulfill the above objectives. in this paper they are classified into 3 classes as follows: (1) axial flow water turbine (afwt), (2) cross flow water turbine (cfwt), and (3) reciprocating wing turbine (rwt). ocean current turbines (mtc) ltd based in uk, with financial support from the dti (department of trade and industry) united kingdom, the german government, the europian community and other partners, has successfully developed a axial flow water turbine (afwt) prototype having 2 blades named seaflow shown in figure 3. it has maximum power capacity of 300 kw, and has been successfully implemented in 2003 in lynmouth, uk. further development is undertaken to enlarge its power capacity [12]. figure 3. seaflow prototype of mtc [12]. hammerfest strom, a subsidiary of the norwegian oil and gas company statoil hydro, has developed an axial flow water turbine (afwt) with 3 blades which can produce maximum power of 300 kw shown in figure 4. this prototype has been installed in the north of norway, near kvalsund [4], [13]. ocean current energy conversion system in wallacea region using variable speed control approach (aditya sukma nugraha, estiko rijanto) pp. 27-34 30 prototype 2003 hs1000tm figure 4. hammerfest strom prototypes [4]. initiated in 2002, verdant power’s roosevelt island tidal energy (rite) project is being operated in new york city’s east river. in three phases, the rite project conducted testing, demonstrating and delivering commercial electricity from verdant power’s free flow kinetic hydropower system (tidal). phase 1 (2002 – 2006): prototype testing, phase 2 (2006 – 2008): demonstration, phase 3 (2009 – 2012): mw-scale build-out [14]. verdant power would build out the rite project in the east channel of the east river to a 1 mw, 30-turbines (gen5), and commercially deliver the energy generated by the field to local customers. figures 5 and 6 show verdant power turbines. figure 5. the turbines are transported to the rite project site (sep.2008) [14]. figure 6. the turbine is being installed in east river (sep.2008) [14]. many other researchers have been doing research and development concerning afwts [15], [16], [17]. some types of cfwt have been researched and developed. some researchers have conducted research on optimization of cross flow turbines and comparison between different types of cross flow turbines [18], [19], [20]. jeronimo zanette et.al. have proposed a new cfwt named harvest 2007 and proved that it has better performance than darriesu 1925, gorlov 1997, and harvest 2004. figure 7 shows turbine types of darrieus (a), gorlov (b), and harvest 2004 (c), and figure 8 shows turbine type of harvest 2007. brian kirke and leo lazauskas proved that variable pitch darrieus water turbines have some advantages compared to fixed pitch darrieus turbines and helical blades. figure 7. turbine types of (a) darrieus, (b) gorlov, and (c) harvest 2004 [18]. figure 8. harvest 2007 turbine geometry [18]. other types of horizontal axis cfwt have also been researched and developed as shown in figure 9 [21], [22]. these types of cfwts are smaller and allow chaining multiple rotors together. a reciprocating wing turbine has been developed by engineering business ltd, united kingdom as shown in figure 10. this prototype was dimensioned to produce a net power of 150 kw and has been implemented in 2002 in yell sound, at the large of shetland island [23]. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 31 (a). solon by atlantis resources corporation. (b). ocgen by ocean renewable power company. figure 9. horizontal axis cfwct [21]. figure 10. reciprocating wing turbine prototype [23]. under the context of green energy resource which should be environmentally friendly, all the design objectives of being well fixed to the seabed, maximizing efficiency, and easiness of maintenance and operation can be wrapped up in a single objective that is minimizing electricity unit cost (electricity selling price) rp/kwh. to estimate electricity selling price, the following price model which is based on conventional engineering economics can be adopted [24]. _ 8760 (2) the electricity selling price ′ in rp/kwh is based on the power purchase agreement (ppa). the levelized factor depends on macro economics indicators and is assumed to be uncontrollable, the levelized maintenance and operation cost ( , ) is assumed to be constant. the maximum (nominal) power capacity , capacity factor , and investment cost per kw maximum capacity depends on the optimization design. power plant operator profit including profit tax can be controlled. the fixed cost ratio is composed by fixed cost components including interest rate, depreciation, income tax, property tax, and insurance. from the above electricity selling price model, it is obvious that scientists and engineers are responsible to optimize the design which minimizes investment cost while satisfying the given technical specifications. to cope with this problem the selection of the best site in the wallacea region is crucial as well as the optimization of the design of the ocecs. such a task needs inter discipline approach including oceanography, mechanical engineering, electrical engineering, electronics engineering, material engineering, civil engineering, and other related fields. iii. result and analysis considering the track record of research and development activities related to wind electrical power plants at the research center for electrical power and mechatronics, indonesian institute of sciences (lipi), as the first step this paper proposes research and development of 3 blade afwt to be implemented in the wallacea region. such afwts have similar power characteristics as wecs whose efficiency curves are shown in figure 11 [25]. figure 11. efficiency vs tsr [25]. from figure 11 it can be noted that there exists maximum efficiency for any water current velocity at certain tip speed ratio (tsr). figure 12 shows effect of yaw angle on the power coefficient in axial flow ocean current turbine having 3 blades [26]. when yaw angle is controlled to be larger the power coefficient becomes smaller for a given tsr. ocean current energy conversion system in wallacea region using variable speed control approach (aditya sukma nugraha, estiko rijanto) pp. 27-34 32 figure 12. effect of yaw to power coefficient [26]. figure 13. ocean current speed at florida, usa [17]. figure 13 shows ocean current speed measured offshore ft. lauderdale florida over a period of nearly 2 years. velocity measurements were made at 15 minute intervals. it shows that the mean current speed near the surface is nearly 1.7 m/s, and can exceed 1 m/s even at the depth of up to 150 m. on average, the florida current decreases monotonically with depth to a weak 0.19 m/s near the ocean bottom at 320 m, in the outer edge of the miami terrace. the current speed ranges between 1 and 2 m/s 85 % of the time, in the top 100 meters. at 50 and 100 m depth, the flow exceeded 2 m/s only 3.3 and 0.06 % of the time, respectively. the predominate direction of the florida current offshore ft. lauderdale ranges between 15° and 16.5°. directional consistency is dependent on velocity, and in the absence of velocity, or during periods of low velocity, the flow direction becomes confused [17]. based on the above preliminary information, the axial flow water turbines having 3 blades which are proposed to be installed at wallacea region will be controlled according to the following control strategy: (1) to maximize energy conversion this paper proposes the use of variable speed control approach. in such approach the turbine rotation speed is controlled so that tsr gives its maximum power coefficient. the turbine rotation speed is controlled by manipulating electrical torque in the generator, (2) no pitch controlled is necessary, (3) the vertical position of the turbine is controlled for 2 purposes: adjusting the maximum power which can be extracted by the turbine, and maintenance, (4) yaw controlled is provided to optimize the operation of the turbine figure 14. the proposed control system for ocecs in the wallacea region. journal of mechatronics, electrical power, and vehicular technology vol. 01, no. 1, 2010 issn 2087-3379 33 the variable speed control approach described by estiko rijanto et. all. which is devoted for wind energy conversion systems can be adopted for this purpose [27], [28]. further elaborations must be carried out to design an optimum mechanism for controlling vertical position and yaw angle. figure 14 illustrates the control system proposed in this paper. basically the control system is composed of two parts coupled by a dc link capacitor. the lower part denotes the controller for generator side while the upper part denotes the controller for grid connection. iv. conclusion the following conclusion can be obtained: (1) ocecs (ocean current energy conversion system) has promising future as green energy resources, (2) the wallacea region possesses ocean current energy potential according to the thermohaline circulation, (3) many types of ocean current turbines can be classified into 3 classes those are: (a) axial flow water turbine (afwt), (b) cross flow water turbine (cfwt), and (c) reciprocating wing turbine (rwt). as the first step, this paper proposes the use of afwt having 3 blades to be implemented in the wallacea region, (4) the afwt will be controlled using variable speed control approach together with vertical position control as well as yaw angle control. as the follow up of the work reported in this paper, an inter discipline r&d team will be established consisting researchers and engineers from disciplines of oceanography, mechanical engineering, electrical electronic engineering, control system, civil engineering, and other related fields to discuss and formulae an action plan including: ocean current potential mapping in the wallacea region, design of an optimum ocecs dedicated for the region, building the ocecs, implementation the ocecs, and monitoring as well as evaluation. financial support is inevitable to make this plan go to reality. in order to accelerate the plan, international cooperation is welcomed. acknowledgment the authors would like to convey their gratitude to dr. alan frendy koropitan, a member of the wallacea young scientists forum from the department of ocean science and technology bogor institute of agriculture (ipb), for providing information concerning oceanography data related to wallacea region. special gratitude is also for prof. dr. umar anggara jenie and prof. dr. sangkot marzuki for the opportunity given to the author to join with the wallacea young scientists conference held in ternate may 13 15, 2010. reference [1] paul spencer sochaczewski, 2008, “survival of the fittest”, international herald tribune, june 21-22. [2] biodiversity hotspots, “wallacea”. accessed on may 30th 2010 from http://www.biodiversityhotspots.org/xp/hot spots/wallacea/pages/default.aspx. [3] ternate visit documentation, “deklarasi ternate ii”, (2010), wallacea young scientists conference, ternate, may 1315. [4] natalia moreno et. al., “ocean current’s energy: how to produce electrical energy thanks to the marine currents?”, report of renewable energy project 2008, hogskolan i gavle. accessed on may 30th 2010 from: http://www.exergy.se/goran/hig/re/08/ocea n.pdf. [5] new, t., r., 2002, “neuroptera of wallacea: a transitional fauna between major geographical regions” from : acta zoologica academiae scientiarum hungaricae 48 (suppl. 2), department of zoology, la trobe university, victoria 3086, australia, pp. 217–227. [6] pt.pln wilayah maluku & maluku utara. accessed on may 30th 2010 from: http://www.plnmmu.co.id/static.php?c=sek ilas. [7] “dprd maluku segera temui dirut pln”, (2010), january 28th. accessed on may 30th 2010 from: http://www.balagu.com. [8] headline news / nusantara / senin, “mahasiswa bentrok di kantor pln maluku”, (2010), april 26th. accessed on may 30th 2010 from: http://www.metrotvnews.com. [9] postdam institute for climate impact research, “the thermohaline ocean circulation: a brief fact sheet by stefan rahmstorf”. accessed on may 30th 2010 from:http://www.pikpotsdam.de/stefan/thc_fact_sheet.html. [10] rahmstorf, s., 2006, “thermohaline ocean circulation”, encyclopedia of quaternary sciences, edited by s.a.elias. elsevier, amsterdam. ocean current energy conversion system in wallacea region using variable speed control approach (aditya sukma nugraha, estiko rijanto) pp. 27-34 34 [11] theory of wind machines, betz equation. accessed on may 30th 2010 from: https://netfiles.uiuc.edu/mragheb/www/np re%20498wp%20wind%20power%20s ystems/theory%20of%20wind%20machi nes%20betzequation..pdf. [12] fraenkel, peter., 2007, “marince current turbines: an update”, all energy ’07, aberdeen, 23 may. [13] strom, hammerfest. “hs1000tm”, accessed on may 30th 2010 from: http://www.hammerfeststrom.com/content/ view/67/102/lang,en/. [14] verdant power, “the rite project: east river – new york”, accessed on may 30th 2010 from: http://verdantpower.com/whatinitiative/. [15] coiro, d.p., maisto, u. scherillo, f., melone, s., & grasso, f., 2006, “horizontal axis tidal current turbine: numerical and experimental investigations”, owemes, 20-22 april, civitavecchia, italy. [16] rachel,f., nicholls-lee, turnock, s.r., & boyd. s.w., 2008, “simulation based optimisation of marine current turbine blades”. university of southampton, southampton. [17] driscoll, f.r., alsenas, g.m., beaujean, p.p., ravena,shirley, raveling,jason, busold, erick, and slezycki, caitlin., 2009, “a 20 kw open ocean current test turbine”. [18] zanette,jeronimo, imbault, didier, & tourabi, ali., 2007, ”fluid-structure interaction and design of water current turbines”, the 2nd iahr international meeting of the workgroup on cavitation and dynamic problems in hydraulc machinery and systems, timisoara, romania, october 24-26. [19] kirke,brian and lazauskas, leo., 2008, ”variable pitch darrieus water turbines”, journal of fluid science and technology, vol.3, no.3. [20] j.d.winchester and s.d.quayle, 2009, ”torque ripple and variable blade force: a comparison of darrieus and gorlov-types turbines for tidal stream energy conversion”, proceeding of the 8th european wave and tidal energy conference, uppsala, sweden. [21] next generation underwater turbines. accessed on may 30th 2010 from: http://peakenergy.blogspot.com/2008/09/n ext-generation-underwater-turbines.html. [22] monty worthington, “ocean renewable power company technology overview”, 2010, aea hydrokinetic technical conference, april 12. accessed on may 30th 2010 from: http://www.tos.org/oceanography/issues/is sue_archive/issue.../23-2_bedard.pdf. [23] anonym, 2007, “status and research and development priorities/2003, wave and marine current energy”, dti report number fes-r-132, aeat report number aeat/env/1054. [24] rijanto, estiko and indahsari devi, merry., 2010, “concept of controlling costs for engineering economics analysis in development of wind electrical power plants in indonesia”, (in indonesian), submitted to majalah teknologi indonesia, bandung, april. [25] d.p.coiro, u.maistro, f.scherillo, s.melone, and f.grasso, 2006, “horizontal axis tidal current turbine: numerical and experimental investigations”, civitavecchia, italy, 20-22 april. [26] von backstrom, theo., 2009, “axial flow turbines for ocean current and wave power systems”, department of mechanical and mechatronics engineering, university of stellenbosch. [27] rijanto, estiko and santoso, adi., 2010, “design of mechanical electrical control system for 100 kw wind energy electrical power plant using 3-phase squirrel cage induction generator”, jurnal instrumentasi, vol.34, no.1, january. [28] rijanto, estiko., 2010, “start up control using dc power supply for isolated mode operation of 100 kw wind power plant”, jurnal ketenagalistrikan dan energi terbarukan, vol.9, no.1, juni. mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology volume 13, 2022 authors index the articles in this volume were authored/co-authored by 76 authors from indonesia, taiwan, malaysia, australia, germany, south korea, united kingdom, vietnam, turkey, thailand, japan, philippines, india, and china. abdullah iskandar syah, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214-221 aditya sukma nugraha, “numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application,” 13(2):125-136 afaf fadhil rifa'i, “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” 13(1):1-14 agung surya wibowo, “design and application of models reference adaptive control (mrac) on ball and beam,” 13(1):15-23 ahmad fudholi, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 ahmad rajani, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 aken derisman, “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” 13(1):88-94 al ichlas imran, “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” 13(1):88-94 aminuddin debataraja, “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” 13(1):95-100 aminuddin debataraja, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 andi setiawan, “torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials,” 13(2):179-188 bagus made arthaya, “design and kinematic analysis of a two-dof moving platform as a base for a car simulator,” 13(1):48-59 bambang riyanto trilaksono, “design and application of models reference adaptive control (mrac) on ball and beam,” 13(1):15-23 charlotha, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 cheng yee ng, “numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system,” 13(2):113-124 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii dalila mat said, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 desmayadi, “plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a,” 13(2):137-146 dian andriani, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 dilek bilgin tükel, “design and kinematic analysis of a two-dof moving platform as a base for a car simulator,” 13(1):48-59 dita andansari, “two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises,” 13(1):79-87 edi kurniawan, “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” 13(2):101112 edwar yazid, “numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system,” 13(2):113-124 edwin muhamma5d puji syamsudin, “design and application of models reference adaptive control (mrac) on ball and beam,” 13(1):15-23 edwin romeroso arboleda, “design, construction, and evaluation of transformer-based orbital shaker for coffee micropropagation,” 13(2):147-156 ehsan ganji, “improvement of power grid stability and load distribution using diesel excitation controller,” 13(1):36-47 hai wang, “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” 13(2):101112 hartono yudo, “torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials,” 13(2):179-188 haznan abimanyu, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 hoe dinh nguyen, “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” 13(1):1-14 ika yuliyani, “load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu,” 13(1):24-35 indra dwisaputra, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 iqbal syamsu, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 jalu ahmad prakosa, “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” 13(2):101-112 langlang gumilar, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214-221 louise indah utami, “load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu,” 13(1):24-35 mailugundla rupesh, “cascade feedforward neural network and deep neural network controller on photovoltaic system with cascaded multilevel inverters: comparison on standalone and grid integrated system,” 13(2):157-178 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 viii mehdi mahdavian, “improvement of power grid stability and load distribution using diesel excitation controller,” 13(1):36-47 mohamad luthfi ramadiansyah, “numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system,” 13(2):113-124 moh. zainul falah, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214-221 mostafa nazih, “effect of lightning mast placement on underground power cable jacket stress within high voltage substations,” 13(2):189-200 muhammad abdul haq, “state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system,” 13(1):60-71 muhammad fathul hikmawan, “numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application,” 13(2):125-136 muhammad iqbal, “torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials,” 13(2):179-188 muhammad iqbal nugraha, “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” 13(1):95-100 muhammad jauhar kholili, “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” 13(2):101-112 muhammad ridho rosa, “design and application of models reference adaptive control (mrac) on ball and beam,” 13(1):15-23 muhammad zakiyullah romdlony, “design and application of models reference adaptive control (mrac) on ball and beam,” 13(1):15-23 muslim, “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” 13(1):88-94 nasarudin ahmad, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 noval lilansa, “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” 13(1):1-14 novie ayub windarko, “state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system,” 13(1):60-71 nur jamiludin ramadhan, “pattern recognition based movement control and gripping forces control system on arm robot model using labview,” 13(1):1-14 ocid mursid, “torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials,” 13(2):179-188 purwinda iriani, “load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu,” 13(1):24-35 ramadhan s. pernyata, “two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises,” 13(1):79-87 raymond christian, “design and kinematic analysis of a two-dof moving platform as a base for a car simulator,” 13(1):48-59 renny rakhmawati, “state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system,” 13(1):60-71 ridho riski hadi, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214-221 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 ix rizal nurdiansyah, “state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system,” 13(1):60-71 robeth viktoria manurung, “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” 13(1):95-100 robeth viktoria manurung, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 royke vincentius febriyana, “two-sided manual machining method for three-axis cnc milling machine for small and medium-sized enterprises,” 13(1):79-87 sarid mejiartono, “numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application,” 13(2):125-136 sevia mahdaliza idrus, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 sohrab mirsaeidi, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 sri hartanto, “plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a,” 13(2):137-146 subkhan, “fabrication of nitrate ion sensor based on conductive polyaniline doped with nitrate using thick film technology,” 13(1):72-78 sujito, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214221 swivano agmal, “experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs),” 13(2):101112 tien-fu lu, “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” 13(1):95-100 tinton dwi atmaja, “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” 13(2):201-213 tran huy duy, “long-term forecasting for growth of electricity load based on customer sectors,” 13(2):214-221 tua agustinus tamba, “design and kinematic analysis of a two-dof moving platform as a base for a car simulator,” 13(1):48-59 vishwanath shivalingappa tegampure, “cascade feedforward neural network and deep neural network controller on photovoltaic system with cascaded multilevel inverters: comparison on standalone and grid integrated system,” 13(2):157-178 wawan purwanto, “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” 13(1):88-94 yanti suprianti, “load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu,” 13(1):24-35 zanu saputra, “carbon electrode sensitivity enhancement for lead detection using polypyrrole, ionic liquid, and nafion composite,” 13(1):95-100 zikri, “study on the production of hydrogen gas from water electrolysis on motorcycle engine,” 13(1):88-94 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 x mechatronics, electrical power, and vehicular technology volume 13, 2022 affiliation index centre of electrical energy system, institute of future energy, utm, malaysia 201 chemistry department, university of warwick, united kingdom 24 department of civil and environmental engineering, universiti teknologi petronas, malaysia 113 department of computer and electronics engineering, cavite state university, philippines 147 department of computer engineering, king mongkut's university of technology thonburi, thailand 36 department of electrical & electronics engineering, bvrit hyderabad college of engineering for women, india 157 department of electrical engineering and computer science, tokyo metropolitan university, japan 60 department of electronics & communication engineering, bheemanna khandre institute of technology, india 157 department of electronics engineering, nscl laboratory, jeonbuk national university, south korea 15 department of manufacturing automation and mechatronics engineering, bandung polytechnic for manufacturing, indonesia 1 department of mechanical engineering, national taiwan university of science and technology, taiwan 125 department of naval architecture, faculty of engineering, diponegoro university, indonesia 179 department of naval architecture, ocean, and marine engineering, university of strathclyde, united kingdom 179 discipline of engineering and energy, murdoch university, australia 101 electrical engineering department, dalat university, vietnam 214 electrical engineering, electrical engineering department, universitas negeri malang, indonesia 214 electrical engineering, state polytechnic of jakarta, indonesia 72, 95 electrical engineering and informatics department, politeknik manufaktur negeri bangka belitung, indonesia 72, 95 electrical engineering department, politeknik elektronika negeri surabaya, indonesia 60 energy conversion engineering department, bandung state polytechnic, indonesia 24 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xi faculty of civil engineering, universiti teknologi malaysia, malaysia 201 faculty of electrical engineering, universiti teknologi malaysia, malaysia 201 faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia 48, 125 faculty of vehicle and energy engineering, phenikaa university, vietnam 1 future energy, ghd pty ltd, australia 189 industrial design, razak faculty of technology and informatics, universiti teknologi malaysia, malaysia 79 institute of semiconductor technology (iht), laboratory for emerging nanometrology (lena), germany 72 intelligent power and advance energy system, jurusan teknik elektro, universitas negeri malang, indonesia 214 jurusan teknik mesin, universitas halu oleo, indonesia 88 jurusan teknik otomotif, universitas negeri padang, indonesia 88 mechanical engineering department, politeknik manufaktur negeri bangka belitung, indonesia 72 mechatronics engineering department, faculty of industrial technology, parahyangan catholic university, indonesia 48 mechanical engineering, national central university, taiwan 88 mechanical engineering, the university of adelaide, australia 95 nissinbou industries, inc, japan 137 product design department, samarinda state polytechnic (politeknik negeri samarinda), indonesia 79 program studi mesin otomotif, universitas muhammadiyah riau, indonesia 88 research center for photonics, national research and innovation agency (brin), indonesia 101 research center for quantum physics, national research and innovation agency (brin), indonesia 101 research center for smart mechatronics, national research and innovation agency (brin), indonesia 113, 125 research center for telecommunication, national research and innovation agency (brin), indonesia 72, 95 research centre for energy conversion and conservation, national research and innovation agency (brin), indonesia 201 research organization for energy and manufacture, national research and innovation agency (brin), indonesia 201 research organization for life sciences & environment, national research and innovation agency (brin), indonesia 201 school of electrical engineering, beijing jiaotong university, china 201 school of electrical engineering and informatics, bandung institute of technology, indonesia 15 school of electrical engineering, telkom university, indonesia 15 software engineering department, dogus university, turkey 48 solar energy research institute, universiti kebangsaan malaysia, malaysia 201 teknik elektro, universitas krisnadwipayana, indonesia 137 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 xii journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university, indonesia prof. juan carlos alvarez dept. electrical engineering, university of oviedo, spain prof. dr. murat lüy department of electrical and electronic engineering, kırıkkale universitesi, turkey prof. istván patkó óbuda university, budapest, hungary dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung, indonesia dr. irhan febijanto, m.eng research center for sustainable production system and life cycle assessment brin, indonesia dr. narankhuu jamsran thomas air llc, mongolia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung, indonesia ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, germany dr. si steve li electromechanical system development, general electric global research centre, united states anusua ghosh school of electrical and information engineering, university of south australia, australia ir. arko djajadi, ph.d. swiss german university, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung, indonesia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang, indonesia dr. ir. rizqon fajar, m.sc. research center for transportation technology brin, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) , indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember, indonesia dr. trina fizzanty research center for education brin, indonesia anna maria sri asih, s.t., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiii dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university , indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales, australia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember, indonesia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau, indonesia pudji irasari, m.sc.rer.nat. research center for energy conversion and conservation brin, indonesia dr. sunit hendrana research center for physics lipi, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan, south korea yusie rizal, ph.d. cand. dept. engineering science, national cheng kung university, taiwan dr. yuliadi erdani politeknik manufaktur bandung, indonesia dr. joga dharma setiawan faculty of engineering, diponegoro university, indonesia dr. esa prakasa, m.t. research center for data and information sciences brin, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung, indonesia dr. widodo budi santoso research center for smart mechatronics brin, indonesia kadek heri sanjaya, ph.d. research center for smart mechatronics brin, indonesia suprapto, ph.d. departement of electronics engineering, yogyakarta state university, indonesia dr. ir. yoyon ahmudiarto, m.sc. research center for energy conversion and conservation brin, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi, indonesia dr. edwar yazid research center for smart mechatronics brin, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university, korea, republic of dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional, indonesia alexander christantho budiman, ph.d. research center for transportation technology brin, indonesia dr. rina ristiana research center for transportation technology brin, indonesia dr. anto tri sugiarto, m.eng. research center for smart mechatronics brin, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia dr. eng. aam muharam, m.t. research center for transportation technology brin, indonesia dr.eng. edy riyanto, s.t. research center for advanced material brin, indonesia dr. anwar muqorobin, m.t. research center for energy conversion and conservation brin, indonesia bambang wahono, m.eng., ph.d. research center for smart mechatronics brin, indonesia ghalya pikra, m.t. research center for smart mechatronics brin, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiv rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi, indonesia vita susanti, s.kom. research center for smart mechatronics brin, indonesia hendri maja saputra, m.t. research center for smart mechatronics brin, indonesia dr. natalita maulani nursam research center for electronics – brin, indonesia dr. joko hariyono, s.t., m.eng. government of yogyakarta special region, indonesia yusuf nur wijayanto, ph.d. research center for electronics – brin, indonesia dr. edi kurniawan, s.t., m.eng. research center for photonics brin, indonesia dr. deni shidqi khaerudini, s.si., m.eng. research center for advanced material brin, indonesia dr. irwan purnama, m.sc.eng. research center for smart mechatronics brin, indonesia achmad praptijanto, s.t., m.d.m research center for smart mechatronics brin, indonesia sunarto kaleg, m.t. research center for transportation technology brin, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi, indonesia midriem mirdanies, m.t. research center for smart mechatronics brin, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi, indonesia erie martides, m.t. research center for advanced material brin, indonesia agus risdiyanto, m.t. research center for energy conversion and conservation brin, indonesia rudi darussalam, m.eng. research center for energy conversion and conservation brin, indonesia dr. hanif fakhrurroja, s.si., m.t. research center for smart mechatronics brin, indonesia aditya sukma nugraha, m.t. research centre for electrical power and mechatronics – lipi, indonesia ahmad rajani, m.eng. research center for energy conversion and conservation brin, indonesia amin, m.t. research center for transportation technology brin, indonesia maulana arifin, m.t. research center for energy conversion and conservation brin, indonesia budi azhari, m.eng. research center for smart mechatronics brin, indonesia henny sudibyo, m.eng. research center for energy conversion and conservation brin, indonesia andri joko purwanto, m.t. research center for smart mechatronics brin, indonesia andry masri, m.sn. department of product design, faculty of art and design, institut teknologi nasional, indonesia roni permana saputra, m.eng. research center for smart mechatronics brin, indonesia sudirja, m.t. research center for transportation technology brin, indonesia dr. eng. eka rakhman priandana, s.t., m.t. research center for energy conversion and conservation brin, indonesia dr. suyoto, m.t. research center for telecommunication – brin, indonesia oka mahendra, m.t research center for smart mechatronics brin, indonesia veny luvita, m.t. research center for environmental and clean technology brin, indonesia mulia pratama, s.t., m.eng. research center for smart mechatronics brin, indonesia asep nugroho, s.si, m.eng, m.sc. research center for smart mechatronics brin, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xv publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (national research and innovation agency). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvi 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident, they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xviii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xix presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xx instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xxi • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor, city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software mev mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.95-102 design of a dc-ac link converter for 500w residential wind generator perancangan konverter dc-ac untuk generator tenaga angin bagi penggunaan perumahan jenis 500w riza muhida a, b, *, ahmad firdaus a. zaidi c, afzeri tamsir a, b, rudi irawan b, d a department of informatics and computer, surya college of education (stkip surya) sure center, jl. scientia boulevard, blok u/7, summarecon gading serpong, tangerang, indonesia b international institute for clean energy and climate change (iicecc) sure center, jl. scientia boulevard, blok u/7, summarecon gading serpong, tangerang, indonesia c school of mechatronics engineering, university malaysia perlis kampus pauh putra, 02600 pauh, perlis, malaysia d department of physics, surya college of education (stkip surya) sure center, jl. scientia boulevard, blok u/7, summarecon gading serpong, tangerang, indonesia received 29 may 2012; received in revised form 25 november 2012; accepted 26 november 2012 published online 18 december 2012 abstract as one of alternative sources of renewable energy, wind energy has an excellence prospect in indonesia, particularly in coastal and hilly areas which have potential wind to generate electricity for residential uses. there is urgent need to locally develop low cost inverter of wind generator system for residential use. recent developments in power electronic converters and embedded computing allow improvement of power electronic converter devices that enable integration of microcontrollers in its design. in this project, an inverter circuit with suitable control scheme design was developed. the circuit was to be used with a selected topology of wind energy conversion system (wecs) to convert electricity generated by a 500w direct-drive permanent magnet type wind generator which is typical for residential use. from single phase ac output of the generator, a rectifier circuit is designed to convert ac to dc voltage. then a dc-dc boost converter is used to step up the voltage to a nominal dc voltage suitable for domestic use. the proposed inverter then will convert the dc voltage to sinusoidal ac. the duty cycle of sinusoidal pulse-width modulated (spwm) signal controlling switches in the inverter was generated by a microcontroller. the lab-scale experimental rig involves simulation of wind generator by running a geared dc motor coupled with 500w wind generator where the prototype circuit was connected at the generator output. the experimental circuit produced single phase 240v sinusoidal ac voltage with frequency of 50hz. measured total harmonics distortion (thd) of the voltage across load was 4.0% which is within the limit of 5% as recommended by ieee standard 519-1992. key words: wind energy, inverter, converter, microcontroller, generator, residential electricity. abstrak salah satu sumber energi terbarukan, yaitu tenaga angin memiliki prospek yang bagus di indonesia khususnya di pinggiran pantai dan di pegunungan, dimana energi angin ini memiliki potensi untuk menyediakan listrik di perumahan. agar pengembangan pembangkit listrik tenaga angin ini dapat berkelanjutan, maka penting untuk memproduksi inverter secara lokal. perkembangan teknologi saat ini di bidang konversi elektronika daya dan teknologi tertanam memungkinkan untuk mengintegrasikan antara mikrokontroller dan converter daya. dalam penelitian ini, rangkaian inverter dengan skema kontrol yang sesuai telah dikembangkan. rangkaian yang digunakan telah dipilih untuk pembangkin listrik tenaga angin bagi perumahan dengan besar konversi 500w. dari keluaran generator berupa tegangan ac kemudian diubah ke dc, lalu digunakan konverter dc ke dc untuk meningkatkan tegangan ke nilai nominal tegangan dc yang sesuai untuk penggunaan domestik. konverter dc-ac yang didesain akan mengubah tegangan dc menjadi ac. sinyal siklus yang dibangkitkan oleh mikrokontroller berupa sinusida modulasi lebar pulsa akan mengontrol switch di dalam rangkaian inverter, sinyal siklus ini akan dijadikan referensi oleh inverter untuk menghasilkan bentuk tegangan sinusida sebagai tegangan keluaran dari inverter yang akan digunakan sebagai sumber listrik di perumahan. mengingat kecepatan angin di indonesia selalu berubah maka dikembangkan suatu alat pengetesan dalam skala laboratorium, yaitu suatu rig simulator, kecepatan rig simulator ini dapat dikontrol untuk menghasilkan kecepatan yang berbeda, rig simulator terdiri dari suatu dc motor yang dihubungkan ke poros generator untuk memutar 500w generator angin, tegangan yang dihasilkan * corresponding author. tel: +62-21-70200270 e-mail: muhida@gmail.com http://dx.doi.org/10.14203/j.mev.2012.v3.95-102 r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 96 oleh generator ini dihubungkan dengan rangkaian konverter dc-ac yang telah dirancang. hasil percobaan menunjukkan bahwa rangkaian konverter ini mampu menghasilkan tegangan keluaran ac sebesar 240v, dan frekuensi 50hz. hasil pengukuran distorsi harmonik keseluruhan sebesar 4% dari tegangan yang dihasilkan ke beban, nilai ini masih memenuhi rekomendasi standard 519-1992 dari ieee. kata kunci: energi angin, inverter, konverter, mikrokontroler, generator, perumahan. i. introduction wind energy is the world's fastest growing renewable energy source. the average annual growth rate of wind turbine installation is around 30% during last 10 years [16, 17, 22, 24]. it is clear that the global market for the electrical power produced by wind turbine generators has been increasing steadily, which directly pushes the wind technology into a more competitive area. wind turbine is the device that converts wind energy into electricity [2-3]. the system is also generally known as wind energy conversion system (wecs). generally there are two types of wind turbine: horizontal-axis wind turbine (hawt) and vertical-axis wind turbine (vawt). the design of horizontal-axis wind turbine (hawt) as shown in fig. 1, consisted of three components namely: 1) rotor component including blades for converting directional wind speed to rotational speed which constitutes 20% of cost, 2) generator component which is approximately 34% of cost, including electrical generator, gearbox (some design uses direct drive), and the control electronics, and finally 3) structural support component which is approximately 15% of the cost including the tower and rotor yaw mechanism [22]. several types of generator were used in wind turbine particularly the hawt types and the common ones were permanent magnet synchronous generator (pmsg), doubly fed induction generator (dfig), induction generator (ig) and synchronous generator (sg) [2, 8]. small wind turbines of generally less than 3kw are suitable to be residential type. small types normally were installed at house lawn area such as the one shown in fig. 1 and some were even small enough to be mounted on the rooftops. the type of generator favoured for this segment was permanent magnet synchronous generator over other types since most urban areas in indonesia have wind supply of less than 5m/s. within these speeds, voltage generated at a particular 500w wind generator permanent magnet type is around 18v to 22v (fabricated by anhui hummer in 2007). a power converter system will then convert the generated electricity to the standard level for user consumption. if a small wind energy system of 500w can operate for 8 hours minimum, the particular household can save about 40% from the usual electricity bills. lately, there is an increasing trend to enable the wecs to supply excess generated energy back to the electricity grid. the public demand for this capability is high on residential type market segment particularly after introduction of net-metering policy in some countries like united states and canada, where consumers were allowed to sell back to the utility companies to offset their consumption [3]. inverter is actually another type of smps (switched-mode power supply) device that transforms voltage from direct current (dc) to alternating current (ac) using switch topology. as shown in fig. 2, it is used together with a boost dc-dc converter and a rectifier circuit in power converter topology to increase the low ac voltage generated at wind generator terminal to nominal ac load and grid voltage. for a typical full bridge, single phase, voltage source inverter (vsi), the circuit consists of h-bridge circuit containing power switches and inverter control circuit that generates triggering signal to switch the power switches in the h-bridge circuit [23]. the objective of this research is to develop and implement inverter control circuit for residential type wind generator with the capacity of 500w. fig 1. installation diagram for hawt [5]. fig.2 wind energy conversion system (wecs) with diode rectifier converter options [9]. r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 97 ii. inverter system a. control circuit the project was expected to turn output voltage generated by a residential wind generator at 18v to 22v to household and consequently being grid compatible of single phase sinusoidal ac voltage of 240v ±5% with frequency of 50hz. the total harmonics distortion (thd) of final output voltage must not exceed 5% as stated in the requirement. the proposed design should be able to meet the above requirements with much lesser components and lower cost. this research was based on experimental approach. from the past research, selected relevant topology and basic circuit, the control algorithm was designed and model simulated under software matlab simulink. as the simulation results confirm with the theoretical model, the values of circuit component were selected and the programming was verified. then, the circuit was built on the prototype board. the circuit was designed under eagle software and built on prototype printed circuit board (pcb). experimental data and result were collected from selected test points on the prototype board using oscilloscopes. the wind generator operation was simulated through a design rig. in the rig, the wind generator was rotated by a dc motor at various speeds from 118 rpm to 400 rpm to simulate its respond to different wind speed. microcontroller used in the system, particularly in the trigger circuit for inverter control is of model pic16f877a. it is a 40-pin enhanced flash-type microcontroller produced by microchip. this microcontroller was used to generate reference sine wave, carrier sawtooth wave, and also the two pulse control signals which were out of phase from each other. some of the key features of the microcontroller which were useful for the project, among others: 2 internal comparators, 5 input/output ports, 8 channel 10-bit analog to digital converter [21]. inverter circuit main job function is to invert the stepped up voltage of 240v from dc to ac. the output voltage must be ideal sine wave with frequency at 50hz and low total harmonic distortion. the circuit consists of h-bridge circuit and control trigger circuit. fig. 3 shows the hbridge prototype circuit schematic diagram. the h-bridge circuit consists of four mosfet transistors q2, q3, q4 and q5 arranged in hbridge formation. the input to the h-bridge circuit is the stepped-up dc voltage while the bridge output of the circuit is taken across points between source of q2 and drain of q4 and between source of q3 and drain of q5. table 1 shows components list that were used in the hbridge inverter circuit. b. control algorithm the input dc voltage will be fed through hbridge circuit where the switches will be n-type mosfet transistors irfp460n. the switching of the mosfet transistors must be out of phase for each diagonal pairs in order to generate square-wave like signal output. also, the switching signal at the transistor gate must be high frequency chopped sinusoidal modulated pulse. to do that trigger signal must be supplied to the h-bridge circuit gates in two channels. channel 1 of the trigger signal will trigger mosfet transistors q3 and q4 while channel 2 of the trigger signal will trigger mosfet transistors q2 and q5. fig. 4 shows the block diagram for inverter trigger control design. the sine wave that is internally generated by the microcontroller is split to two channels. the sine wave must be non-biased. a variable dc signal is also split to two channels where one channel is negative biased of the other with similar amplitude. in comparator 1, the sine wave is compared with the positive dc input to generate trigger control channel 1. in comparator 2 the sine wave is compared with the negative biased dc input to generate trigger control channel 2. amplitude of the dc input signal will determine width of the generated trigger control pulse. smaller fig 3. schematic diagram of h-bridge inverter circuit (shown without lc-filter components and load). table 1. component list for h-bridge inverter circuit. no components specifications quantity 1 mosfet q2, q3, q4, q5 irfp460/ 500v/20a 4 2 inductor 18mh/ 3a 1 3 capacitor 330uf/ 500v 1 4 resistive load 480ω/ 600w 1 r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 98 amplitude will increase the trigger control pulse width while bigger amplitude will decrease the trigger control pulse width. after successful simulation of the control algorithm using matlab simulink, hardware version of trigger control circuit is built and the algorithm was translated into c program that will be used by microcontroller. the trigger circuit mainly consisted of microcontroller pic16f877a, comparator ic lm324, ic 74244. the microcontroller generates reference sine wave, carrier sawtooth wave, and also the two pulse control signals which were out of phase from each other. through firmware, the reference sine wave signal was generated at port b with frequency of 50hz. sawtooth carrier signal was generated at frequency 2 khz through initialization of pwm module at pin ccp1 where the pulse signal was later modified to be sawtooth by filtering. internal comparator modules c1 and c2 were activated through microcontroller firmware. fig. 5 shows the block diagram of the flow of the experiment according to the selected topology. to simulate the problem statement, residential type wind turbine was to be used with condition of low wind power, with wind speed around 3m/s to 5m/s. based on topology selected, the residential wind generator to be used is permanent magnet synchronous generator (pmsg), direct drive type (which does not utilize gear transmission to increase the turbine rotational speed). for this purpose, a 500w wind turbine system was purchased. voltage generated at the generator terminal is single phase ac type and very low amplitude. the output voltage is then connected to rectifier circuit to transform the voltage to dc type. next, boost converter was used to step up the voltage to nominal grid voltage of around 240v. after that, inverter circuit was used to invert the dc voltage to ac voltage. necessary performance parameters of the output voltage such as amplitude, frequency and total harmonics distortion (thd) were measured and analysed to ensure the generated output being compatible to be supplied to the grid. voltage data from wind generator performance datasheet was used as basis during simulation stage where circuit at each stage was designed and simulated for output. c. design of wind generator simulator rig wind generator simulator rig was developed to test the performance of the power converter in case the wind speed of the identified sites did not reach the minimum steady speed of 3m/s since that was the startup speed of the wind generator [3]. in the rig design, the concept of wind generator simulation was to simulate the different wind speed by rotating the wind generator at different rotational speed. the relationship of wind speed and generator rotational speed for a specific wind turbine will be shown. the purpose was to observe generated power and response of power converter with respect to different wind speed. in the simulation other factors such as effect of wind turbine blade and air density were neglected. aerodynamic power, pt (w) captured by wind generator is dependent on the wind speed where the formula is given by: 𝑃𝑃𝑡𝑡 = 1 2 𝐶𝐶𝑝𝑝 (𝜆𝜆)𝜌𝜌𝜋𝜋𝑅𝑅2𝑣𝑣𝑊𝑊 3 (1) where 𝜌𝜌 is air density (kg.m-3), 𝑣𝑣𝑊𝑊 is wind speed (m/s), cpis coefficient of performance, and r is turbine blade radius (m). tip speed ratio, λ of a wind generator is ratio between the blade tip speed (m/s) to the wind speed (m/s). λ = blade tip speed (m/s)/wind speed (m/s) (2) blade tip speed can be calculated using the formula: blade tip speed = generator shaft rotational speed (rpm) x π x 2r (m) /60 (s) (3) from the formula (2) and (3), relationship between the wind speed (m/s) and generator fig. 4. block diagram for inverter trigger control. fig. 5. block diagram of the experimental flow. r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 99 rotational speed (rpm) for a specific wind turbine could be derived as follows: 𝑣𝑣𝐺𝐺 = 30𝜆𝜆𝑣𝑣𝑊𝑊 𝜋𝜋𝑅𝑅 (4) where 𝑣𝑣𝐺𝐺 is generator shaft rotational speed (rpm), 𝑣𝑣𝑊𝑊 is wind speed (m/s), λ is tip speed ratio, and r is turbine blade radius (m). from manufacturer performance data of wind generator, radius of the turbine blade was 1.35m, rated shaft rotational speed was 600rpm at rated wind speed of 7m/s [3]. tip speed ratio of this turbine was calculated using formula (2) and (3) where the value was 12.11. hence, for this particular wind generator, formula of (4) can be further reduced: 𝑣𝑣𝐺𝐺 = 85.65𝑣𝑣𝑊𝑊 (5) to simulate wind speed to 5m/s, based from formula (5), shaft of wind generator needs to be rotated at 428 rpm at least. torque of an electric motor can dc motor was selected as prime mover to rotate the wind generator. this was due to ability to change the rotation speed of motor shaft by varying the dc supply voltage to the motor. the rotating generator part without the wind blade was taken from the wind generator set assembly. connection of the dc motor to the wind generator was through a direct coupling. hence motor with adequate torque power was needed to rotate the wind generator at desired speed. below is the calculation of minimum torque needed to rotate wind generator: weight of wind generator, m1 = 6.5kg, weight of transmission element, m2 = 0.5kg, total mass weight, m = m1+m2 = 7.0kg, perpendicular radius of transmission element, r = 0.11m. torque = perpendicular radius, r x m.g (6) so the torque is = (0.11m) x (7.0kg) (9.81m/s2) = 7.55 n.m = 1069.17 oz-in. required power for dc motor can be calculated through the formula below: power = required rotational speed (rpm) x required torque (oz-in) /1350 (7) so the power is = 428 x 1069.17/1350 = 339w. but dc motor with rating more than 300w was very difficult to find in local market and also is very costly. hence dc motor with rating 300w was used with slightly compromising maximum wind speed it can emulate. from (7), motor with 300w can rotate wind generator rig at 10% less than intentional speed. fig. 6 shows the experimental rig for the wind generator simulator. in this rig, wind generator was connected to a geared dc motor through a flexible coupling. the output of the rig was connected to a resistive load. it has been indicated by vendor of this 500w wind turbine that rated wind generator output for this model is 500w at wind speed of 7m/s where the rotational speed was at 600 rpm while the start-up speed for the wind generator to operate was at wind speed of 3m/s. variable output power supply was used to generate various input supply voltage to dc motor which, in turn rotated wind generator at different speed between 118 rpm to 400 rpm. inverter circuit main job function is to invert the stepped up voltage of 240v from dc to ac. the output voltage must be ideal sine wave with frequency at 50hz and low total harmonic distortion. the circuit consists of h-bridge circuit and control trigger circuit. d. filtering of output voltage for an ac output voltage with low distortion, and the output frequency is constant, l-c lowpass filter circuit is used to decrease distortion. the voltage on the output of the filter will closely resemble the shape and frequency of the modulation signal. this means that the frequency, wave-shape, and amplitude of the inverter output voltage can all be controlled as long as the switching frequency is at least 25 to 100 times higher than the fundamental output frequency of the inverter. the basic principle is simple. the filter circuit is a frequency-dependent voltage divider. under ideal conditions, the transfer ratio (vout/vin) for the fundamental is equal to one, and for the other harmonics it is equal to zero. in the basic version of the filter circuit as in fig. 7, the ideal behavior fig. 6 (a) experimental rig for wind generator simulator; (b) turbine rotational speed and generator terminal output measurement. fig. 7. lc filtering at output [15]. r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 100 is approximated using a series resonant circuit in the input of the filter, and a parallel resonant circuit in the output. the circuit is tuned to the fundamental frequency. therefore, the transfer ratio for the fundamental is equal to one, and the inverter is not loaded with the reactive power of the parallel output capacitance. for the harmonics, the series impedance increases with frequency, and the parallel impedance decreases. this effect ensures a certain reduction in the harmonic voltages. if this reduction is not adequate, series resonant circuits, which are tuned to various harmonic frequencies, will be connected in parallel with the output. the resulting output will be short-circuited at the chosen frequencies. the dynamic behavior of this filter circuit is not good at load jumps because of the large number of energy-storage elements. since modern converter circuits are used with a high internal frequency (e.g., 20 khz at pwm), the necessary filter circuit is simpler. if an output transformer is also used, the transformer values are calculated such that the series inductance of the filter circuit is given by the transformer's leakage inductance and the parallel inductance is equal to the transformer's magnetizing inductance. to ensure the required magnetizing inductance, the application of an air gap in the iron core is necessary. using modern converter techniques, low distortion levels (a few percent) and very good dynamic behavior (5 to 10% overshoot at load jumps) can be achieved [15]. iii. results and analysis a. results of wind generator simulator rig test run results of the wind generator simulator rig based on design that has been described in ii. c shown in fig. 8, wind generator was rotated by dc motor at various speed as the output was connected to a resistive load. the data for simulator rig starts at lower speed due to constraints of dc motor as prime mover to the rig. the result from the graph agrees with the manufacturer performance datasheet where as the rotational speed increase due to increasing wind speed, the voltage output increase. from the graph, the generated voltage at wind speed ranging from 3 to 5 m/s was around 13 to 20 v. the generated voltage at the terminal was single phase ac type with a variable frequency that also increases as the speed increase. from the simulation rig, power generated across the load was slightly above 40w. hence rating for components at rectifier circuit was selected to be within 50v for voltage and 50w for power. b. simulation results of inverter a simulation results of the inverter system shown in fig. 9. the control algorithm for the generation of trigger control signal method using unipolar switching spwm has been explained in ii. b. amplitude modulation ratio, was selected to be at 0.8 because ratio of less than 1 has linear effect on amplitude of fundamental frequency component while ratio exceeding 1 will have noticeable increase in output distortion. frequency modulation ratio, was selected to be at 40 to be sufficiently high to enable better control of amplitude, wave shape and frequency of the inverter output. reference sinusoidal frequency was selected at 50hz while carrier sawtooth frequency was selected at 2khz. these parameters were also comparable with works by [6], that selected and values to be 0.8 and 150 respectively. fig. 9(a). shows output voltage after the mosfet h-bridge circuit. the input to the hbridge circuit was 240v dc voltage. the output was deployed as pwm pulses with amplitude 240v along the positive and negative sides. the output obtained is not sinusoidal because the lc filter was not included in the design. figure 9(b). shows the output voltage after implementing the lc filtering components in the circuit. from the graph the output voltage has sinusoidal shape with amplitude 240v and frequency 50hz which has met criteria set by objective. thd measurement of the output voltage after lc filtering was 2.3% as shown in fig. 9(c). c. experiment results of inverter this section includes final experimental results obtained after running the wind simulator rig with inverter system connected as per selected topology in fig. 6. the rig was run at 300 rpm (which is equivalent to wind speed of 3.5m/s) to generate around 20v of energy at terminal. a resistive load with resistance 480ohm and power rating 120w was connected to inverter output. fig. 8 wind generator simulator rig output at different generator rotational speed. r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 101 figure 10(a). shows the output of the voltage after the mosfet h-bridge circuit before lc filter. the output was deployed as pwm pulses with amplitude 240v along the positive and negative sides. figure 10(b) shows the output voltage after implementing the lc filtering components in the circuit. from the graph the output voltage has sinusoidal shape with amplitude 240v and frequency 50hz which has met criteria set by objective. the sinusoidal output voltage signal was then sampled as data where the fourier transform was calculated for each sample points. then the thd was calculated using formula from ref [23]. table 2 shows summary of results for simulation and experimental. in the simulation, output voltage of inverter design using unipolar switching spwm achieved all requirements set by the objectives. experimental results of inverter output voltage where the inverter system is connected to the wind generator simulator rig rotated at 300rpm. both simulation and experimental results showed that research design objectives have been achieved. by comparison with past works by aphiratsakun [6], in the simulation, both output voltage shown in figure 9.a. matched the simulation result while in the experiment, only output voltage before filtering in figure 10.a matched the experimental result. however, filtered output in figure 10(b) has basic resemblance with experimental result. (a) (b) (c) fig. 9. (a) output voltage after the h-bridge circuit before lc filtering; (b) output voltage after lc filtering; (c) thd measurement of simulated output voltage after lc filtering. 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 -250 -200 -150 -100 -50 0 50 100 150 200 250 time (sec) v ol ta ge ( v ) output voltage after h-bridge 0.2 0.21 0.22 0.23 0.24 0.25 0.26 -250 -200 -150 -100 -50 0 50 100 150 200 250 time (sec) v ol ta ge ( v ) inverter output voltage after lc filtering 0 0.05 0.1 0.15 0.2 0.25 0.3 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 x: 0.15 y: 0.02289 time (sec) r at io thd measurement for simulated inverter voltage output (a) (b) fig. 10. (a) output voltage after h-bridge circuit on prototype board; (b) inverter output voltage after lc filtering on prototype board. table 2 summary of results for inverter circuit output. parameters simulated unipolar spwm experiment unipolar spwm objective peak amplitude 240v 240v 216v – 252v frequency 50hz 50hz 50hz thd 2.3% 4.0% less than 5% r. muhida et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 95-102 102 iv. conclusions in this paper simulation and experimental results were included together with explanation and analysis. final simulation result complied with the project objective that the output of inverter voltage should be sinusoidal with peak voltage 240v, frequency 50hz and thd below 5%. finally when the rig was run with all hardware connected according to topology, the measured output voltage complies with the project objective which voltage should be sinusoidal ac with peak voltage 240v, frequency 50hz and thd below 5%. references [1] agrawal, j. p. "power electronic systems: theory and design". prentice hall, 2001 [2] ahmed m. tahir., riza muhida., & a.z. ahmad firdaus, "fuzzy-tuned pid control inverter for single phase ac induction motor". proceeding of the 2nd international conference on engineering and ict, pp. 199-203, malacca, malaysia, feb 2010. [3] ahshan, r. "control system for small induction generator based wind turbines." unpublished master thesis, memorial university of foundland, canada, 2007. [4] akhter, r., & hoque, a. "analysis of a pwm boost inverter for solar home application". proceedings of world academy of science, engineering and technology, 17, issn 1307-6884. dec 2006. [5] anhui hummer dynamo co. ltd. "hummer 500w wind turbine operation manual," 2007. [6] aphiratsakun, n., bhaganagarapu, s. r., & techakittiroj, k. "implementation of single phase unipolar inverter using dsp tms320f241. au journal, 8(4), pp. 191195. , april 2005. [7] arifujjaman, md., iqbal, m. t., quaicoe, j. e. "maximum power extraction from a small wind turbine emulator using a dc dc converter controlled by a microcontroller," electrical and computer engineering int. con., 213-216. dec. 2006. [8] a.z. ahmad firdaus., riza muhida., a. z. ahmad mujahid., s. yaacob., & nur hidayah ahmad zaidi, "development of dc-ac link converter for wind generator." in proc. of the int. con. on electrical energy and industrial electronic systems, penang, malaysia. dec. 2009. [9] baroudi, j. a., dinavahi, v., & knight, a. m. "a review of power converter topologies for wind generators". renewable energy, 32 (14), pp. 2369-2385. 2007. [10] beck, y., bishara, b., & medini, d. "connecting an alternative energy source to the power grid by a dsp controlled dc/ac inverter.", power engineering society inaugural conference and exposition in africa (ieee '05), 120-124. jul. 2005. [11] begley, sharon. (2010, january 28). in defense of ethanol: lab notes archives 12 may 2008. [online]. available: http://blog.newsweek.com/blogs/labnotes/ar chive/2008/5/12.aspx [12] calwell, c., & reeder, t. "power supplies: a hidden opportunity for energy savings." nrdc report: 22nd may, 2002. [13] chen, z., & blaabjerg, f. "wind energythe world's fastest growing energy source" ieee power electronic society newsletter, 18 (3), 15-19. 2006. [14] erlich, i., wintern, w., & dittrich, a. "advanced grid requirements for the integration of wind turbines into the german transmission system," ieee power engineering society general meeting: 18th22nd june, 2006. [15] giesselmann, m., & karpati, a. "the power electronics handbook. " crc press. 2002 [16] .____ (2010, feb 12). "global wind energy council's report." [online]. available: http://www.gwec.net/uploads/media/ gwec2006_final.pdf. 2006 [17] hansen, a. d., & hansen, l. h. "wind turbine concept market penetration over 10 years (19952004)". wind energy, 10 (1), 81-97. 2007. [18] harrison, r., hau, e., & snel, h. "large wind turbines design and economics," john wiley & sons. 2000. [19] li, h., & chen, z. "overview of different wind generator systems and their comparisons. iet renewable power generation", doi: 10.1049/iet-rpg:20070044. 2008. [20] (2010, jan). "malaysia energy database and information system." [online]. available: http://medis.ptm.org.my/highlights..html [21] microchip. "pic16f87xa datasheet 40 pin enhanced flash microcontroller.", 2003. [22] national renewable energy laboratory. (2010, january 28). [online]. available: http://www.nrel.gov/learning/re_basics.html. [23] rashid, muhammad h. "power electronics: circuits, devices, and applications," (3rd ed.,). pearson/prentice hall. 2004. [24] us department of energy. (2010, january 28). [online]. available: http://www1.eere.energy.gov/windandhydro/ hydro_plant_type.html mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.36-47 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: e. ganji and m. mahdavian, “improvement of power grid stability and load distribution using diesel excitation controller,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 36-47, july 2022. improvement of power grid stability and load distribution using diesel excitation controller ehsan ganji a, *, mehdi mahdavian a a department of computer engineering, king mongkut's university of technology thonburi 126 pracha uthit rd, bang mot, thung khru, bangkok 10140, thailand received 14 march 2022; 1st revision 30 april 2022; 2nd revision 12 may 2022; accepted 20 may 2022; published online 29 july 2022 abstract one of the requirements for controlling hybrid power systems is designing an appropriate excitation system, flexibility, protection, and coordination of all components to improve system stability. in this paper, various types of equipment simulated in the linear form and non-linear models are connected to the power supply. in the same direction, while presenting a new controller for the diesel generator excitation system and a filter used to purify and attenuate current harmonics is reported on the stability of a grid-independent system. finally, the variation of the mode for the voltage and power of the system has been confirmed at the time of error and complete system stability. also, the important indicators in the analysis are obtained in the lowest values, which can be seen from the controlled harmonics of the system of this data. in addition, the variation of the mode for the voltage and power of the system has been confirmed and the important indicators in the analysis are obtained in the lowest values. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: hybrid power systems; improve system stability; non-linear control models; excitation system; load distribution. i. introduction electricity consumption has increased dramatically over the past few decades. one way to provide this energy is to increase the use of small independent grids that can be powered by renewable energy. basically, in independent systems, there are many problems in the field of stability of the power generation system in the event of imbalances and the effects of transmission lines, and several studies have been conducted to stabilize the output voltage. in [1], to solve the synchronous machine fluctuations in different operating conditions, three methods of an automatic voltage regulator, automatic voltage regulator with power system stabilization, and active disturbance rejection control (adrc) methods have been used for the parallel excitation system of two generators. in [2], diesel technologies have been investigated as an accurate solution for renewable energy penetration focusing on engine time delay and generator inertia constant which is considered in the design of an isolated hybrid power system. in [3], an mg system is modeled to analyze interactions in which a gridfed voltage converter and a grid-forming system are investigated in their constituent structure. the major purpose of [4] is to present the status of variable speed diesel generators (vsdg) technologies and evaluate their performance in fuel, increase engine performance and reduce greenhouse gas (ghg) emissions based on performance evaluation and degree of innovation. in [5], information and stabilization of microgrid stability are presented and investigated by considering the characteristics related to small networks along with voltage dependence on frequency, perturbation, and low inertia. in [6], the effectiveness of the genetic algorithm (ga) algorithm in an independent system is presented and validated for comparison with proportional integral derivative (pid) control in the excitation control of a diesel generator used on the coast. in [7], the presentation of the pid controller is shown for two modes of constant excitation value and feedback loop value and selected as an efficient and convenient method along with an alf and vegard's risc (avr) processor system for the excitation controller system of an asynchronous machine. the authors in [8] have modeled a hybrid power system the size of an electronic assembly in * corresponding author. tel: +98-918-5549181 e-mail address: mr.ehsanganji@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.36-47 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.36-47 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.36-47&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 37 which a logical and digital excitation controller is used as the output regulator of a diesel generator. also, reliability is considered for advanced performance practices in dealing with island conditions. in [9], a synchronous diesel machine system using a power supply equipped with system voltage control (svc) with a fuzzy controller is proposed to regulate the reactive power of the injection. the authors also used capacitive banks to set up and stabilize the generator in the shortest possible start-up time. in [10], a reason for using independent scalable and reproducible grids has mentioned intelligence and intricate analysis. they also outline methods for increasing and grid small replicating. in [11], series switches have been used to reduce the interrupt frequency in small and independent grids. reliability is also included for fast performance in the face of island mode. in [12], stabilization systems and flexible power devices for transient stabilization mode have also received special attention. in [13], the excitation system model has considered evaluating the stability of the system. the use of fuzzy methods and ant colony optimization to reduce losses, improve voltage, and increase the load balance of feeders in the reference [14] has suggested that this algorithm is more accurate than other optimization methods such as genetics and particle swarming. in [15], a detailed model has been presented for power source dynamics and load for frequency effects. to prevent voltage and frequency deviations in a power system, inverter dynamic control strategies have been proposed in the event of an error and the presence of inductive motor loads [16][17]. in [18], a comparison of microgrid systems has confirmed which energy management strategies have been considered for feasibility and control. in [19], an inverter-based distributed controller and mechanical loads were investigated in interrupt conditions, which indicates that this system may lose its stable performance in different loads presence, but the use of reverse strategy improves the situation. in [20], a metaheuristic control scheme is developed to reduce lowfrequency fluctuations and voltage disturbances of a multi-machine system in coordination with an optimized static synchronous compensator. in [21], a control strategy using virtual synchronous generators is used to synchronize output voltages without feedback. designing and synchronizing an advanced frequency response system using a virtual technique can have significant results in tracking the point force of a permanent magnet generator to store active power. in diesel-wind hybrid systems, the desired system does not remain stable without a storage system with a diesel generators (dg) and clutch. in this paper, the design of a new controller has been suggested for the excitation system of an emergency diesel generator in a small independent grid. here, the use of nonlinear systems and feedback control for system controllers in a small autonomous network is an innovation in this paper. to confirm the performance of this system and its use in power grids, two modes of non-oscillation and oscillation of power machines has proposed with the occurrence of transmission line error. ii. materials and methods in figure 1, the system under study is presented. the study platform is an independent system that is initially ideal for use in a small network, then the information and data are expanded and completed in the form of an analytical project. this system independently consists of two basses, in bus 1 of 25 kv network with equivalent resistance-selfie, and a load with a power of 5 mw. taking into account the error, the short circuit level 1000 mwa is modeled for quality factor x/r = 10. bus 2 is powered by a resistive load and an asynchronous machine. this is done with the help of a 25 kv distribution line and a 6 mw transformer. in case of necessity, a synchronous machine is used as the capacitor bank of 500 kvar to correct the power factor in bus 2. the 25 kv grid is modeled with a resistive-inductive equivalent source and a load with a power output of figure 1. diagram of the studied system e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 38 5 mw. also, an asynchronous machine with a power of 2250 hp is considered, 2.4 kv, and an asynchronous machine with a power of 3.125 mva. initially, the motor generates a mechanical power of 2000 hp and the diesel generator generates 500 kw of active power. the synchronous machine controls the voltage of 2400 volts of bus 2 equals to 1 pu and provides the active power of 500 kw in the hands of the consumer [12]. a. synchronous machine block the outputs of the voltage and speed of the synchronous machine are used as input feedback in a control system that includes the engine, diesel, steering blocks, and the excitation block. the components of the synchronous machine are shown in figure 2. in this block diagram, the design and control are done for the machine completely. first, the values of rotor speed and angle are entered into the reference conversion block from the left, and then the obtained information enters the synchronous model block. at its output, we have the torque and other parameters, and in the last block to the right of the measurement block, we have the necessary parameters. the modeling of this diagram is done in the reference frame of (1) and (2). 𝑉 = [𝑅] + 𝑑𝑑ℎ𝑖 𝑑𝑑 + [𝜔] × 𝑝ℎ𝑖 (1) 𝑝ℎ𝑖 = [𝐿] × 𝐼 (2) where [r] is the machine resistance matrix in the dq axis, [l] is the machine inductance matrix in the dq axis, [𝜔] is the speed matrix of the rotor, v is voltage measured from output feedback, 𝑑𝑝ℎ𝑖 is flux derivative obtained from matrix reactance and i is inside the machine model block. certain data and parameters must be modeled for function and design in harmony with other dynamic parts of the system. linear and nonlinear relationships are the most important parametric changes in the machine model. in the following, the dynamic models for synchronous machine modeling are designed as follows: �̇� = 𝑤 − 𝑤𝑟𝑟𝑟, �̇� = − 𝐷 2𝐻 (𝑤 − 𝑤𝑟𝑟𝑟) + 𝑤𝑟𝑟𝑟 2𝐻 (𝑃𝑚 − 𝑃𝑟) (3) 𝐸 = ′̇𝑞 1 𝑇𝑑𝑞 ′(𝑥𝑑−𝑥𝑑 ′) 𝑇𝑑 𝑑 1 𝑇𝑑𝑟 (4) �̇�𝑑 ′ = 1 𝑇𝑞 𝐸𝑑 ′ + (𝑥𝑞−𝑥𝑞′) 𝑇𝑞 𝐼𝑞 (5) 𝐼𝑞 = 1 𝑃1 2+𝑃2𝑃3 �𝑃1(𝐸𝑞′ − 𝑉𝑉) + 𝑃3(𝐸𝑑 ′ + 𝑉𝑦)� (6) 𝐼𝑑 = 1 𝑃1 2+𝑃2𝑃3 �−𝑃2(𝐸𝑞′ − 𝑉𝑉) + 𝑃1(𝐸𝑑 ′ + 𝑉𝑦)� (7) 𝑉𝑑 = 𝐸𝑑 ′ − 𝑅𝑎𝐼𝑑 − 𝑉𝑞′𝐼𝑞, 𝑉𝑞 = 𝐸𝑞′ − 𝑅𝑎𝐼𝑞 − 𝑉𝑑 ′𝐼𝑑 (8) 𝑉𝑑 = �𝑉𝑑 2 − 𝑉𝑞2, 𝑃𝑟 = 𝐸𝑞′𝐼𝑞 + 𝐸𝑑 ′𝐼𝑑, 𝑄𝑟 = 𝐸𝑞′𝐼𝑑 + 𝐸𝑞′𝐼𝑑 (9) where 𝛿 is derivative of machine speed difference, 𝑤 is machine speed, 𝑤𝑟𝑟𝑟is machine reference speed,�̇� is derivative of the main speed of the machine, 𝐷is damping coefficient, 𝐻 is inertia constant, 𝑃𝑚 is mechanical power, 𝑃𝑟, 𝑄𝑟are electrical and reactive electrical power, p1,p2,p3 are power values in ephemeral states,𝐸𝑞′ ,e𝑑 ′ are internal dq-axis stator voltages , 𝑉𝑑, 𝑉𝑞 are dq-axis reactance, 𝑇𝑑, 𝑇𝑞 are dqaxis torque, 𝐼𝑑, 𝐼𝑞 are dq-axis current, 𝑉𝑑, 𝑉𝑞 are dqaxis voltage, and 𝑉𝑥, 𝑉𝑦 are xy-axis voltage. b. 7bdiesel block and its controller in figure 3, the diesel model diagram is designed with the system under study. here, the system is designed to create the necessary mechanical power for the synchronous machine to rotate in a nonlinear manner. the feedback speed enters the nonlinear controller section in line with the reference speed, then is applied to the motor section. the mechanical power output appears in a controlled manner in the synchronous machine. 𝐶𝐶 = 0.2𝑠+1 0.0002𝑠2+0.01𝑠+1 (10) 𝑇𝑇1 = 0.25𝑠+1 0.009𝑠+1 (11) figure 2. block diagram of the designed synchronous machine e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 39 𝑇𝑇2 = 1 0.384𝑠+1 (12) in the design of the controller of this system, non-linear relations have been used for the flexibility of the system by considering the natural modes for the diesel generator at different times. in fig. 3, cs is the system controller, whose function is as a regulator, and tf1, tf2 are related to the diesel actuator for non-linear control. the excitation controller diagram is designed as follows and the required data are given in table 1. mode variables for diesel excitation will follow the following designed process and in the following equations, x (1, 2, 3, 4, 5) and a (0, 1, 2, 3, 4, 5, 6, 7) are variable coefficients to obtain non-linear relationships in control feedbacks. �̇�1 = 𝑉1 �̇�2 = -a0𝑉2 + a1𝑃meca1𝐼𝑞𝑉3 a1𝐼𝑑𝑉4 �̇�3 = -a2𝑉3 a3𝐼𝑑 a2𝑉5 �̇�4 = -a4𝑉4 + a5𝐼𝑞 �̇�5 = -a6𝑉5 + a1(𝑊𝑟𝑟𝑟 + 𝑈 − 𝑊𝑑) (13) figure 4 shows a nonlinear section for the diesel controller, where wt is unit speed in time, where 𝑉1 ,𝑉2 = (𝜔 − 𝜔𝑟) , 𝑉3 = 𝐸𝑞′ ,𝑉4 = 𝐸𝑑 ′ ,𝑉5 = 𝐸𝑟 ,𝑈 = 𝑇. 𝐴𝑖,𝐴𝑖=0,1,...,7 which are given by 𝐴0 = 𝐷 2h , 𝐴1 = 𝜔𝑟 2𝐻 , 𝐴2 = 1𝑇𝑑, 𝐴3 = 𝐿𝑑-l𝑑 ′ 𝑇𝑑 (14) 𝐴4 = 1 𝑇do ″ , 𝐴5 = 𝜙d-𝜙𝑞 𝑇𝑑 , 𝐴6 = 1 td′ , a7= 1 td′′ (15) for the overall stability of the excitation system, also a filtered reversing controller is designed with a gradual strategy and feedback for the diesel controller. the diagram and operation process of which is shown in figure 5. figure 4. presentation of diesel controller design figure 3. diesel block diagram table 1. diesel control parameters inductancees (pu) machine constant (sec) saturation data ld=1.56; lq=1.06 tdo' = 3.7 s(1,0)=0.1724 ld'=0.296; lq"=0.177 tdo'' = 0.05 s(1,2)=0.6034 ld"=0.177 tdo' = 0.05 l1=0.088 h=1.0716 e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 40             ++      = = )( 2 s21 2 s -2 nr n rn2 21 xrsppp pp mζ ω ζ ω ζω  (16)       ≤→− 〈→ ≥→ = mxm mxx mxm xs rif rifr rif r m )( (17) where ζ is damping coefficient, nω is synchronous speed, rs is saturation data, and ms is saturation mutual data. in this proposed system, voltage harmonics are created by current harmonics. voltage harmonic is created by the uneven voltage generated by the harmonic effect of the current with the source impedance. current and voltage harmonics are directly proportional to the transmission of noise (energy interference) to the load, so the filter in figure 5 is used to purify and attenuate current harmonics. c. diesel engine model the diesel engine model is shown in figure 6, which includes the governor, actuator and engine delay. the dynamic modeling relationships are also presented. in figure 6, the mechanical power is generated in the engine system and is controlled by a diesel injection sensor. the elements in the figure, such as governor function hg, actuator function ha, and t (1, 2,…, 6) different values of torque in feedback, are expressed as [9]: )1(1 )1( 2 211 3 sttst stk h g +++ + = , )1()1( )1( 65 4 ststs st h a +++ + = (18) d. asynchronous machine parameters the asynchronous machine parameters are based on the si system. the rotor reference frame and other parameters considered are tabulated in table 2. iii. results and discussions typically, the initial conditions of the synchronous and asynchronous machines in a steady state are not clear; these conditions are: • in synchronous machine block: the initial value of speed deviation, the rotor angle, the phase and amplitude of the current in the stator windings, and the initial field voltage required to reach the desired output voltage under specified load distribution. • in asynchronous machine block: the initial amount of slip, phase, and amplitude of the motor windings current in figure 7, at the beginning of simulation in the asynchronous machine, the stator current values start at zero and the initial dc values gradually disappear. in figure 8, the machine speed due to unbalanced conditions and variable load to achieve a steady-state takes time. we review here the two systems of non-oscillating and oscillating systems for checking the load distribution of the machines. figure 5. reverse backup filter model figure 6. schematic of a diesel engine table 2. asynchronous machine parameters parameters values nominal power, voltage(line to line), frequency [1678500 va, 2400 vrms, 60 hz] stator resistance and inductance [0.029 ohm, 0.0226/377 h] rotor resistance and inductance [0.022 ohm, 0.0226/377 h] mutual inductance lm 13.04/377 h inertia, friction factor, pole pairs [63.87 j, 0 f, 2 p] e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 41 a. load distribution in non-oscillating machine mode figure 9, figure 10, figure 11, and figure 12 show the mechanical reaction, speed, and output voltage of the synchronous machine and the control signal for the diesel and generator system. voltages and currents parameters of non-linear blocks are provided in table 3. figure 7. stator currents asynchronous machine figure 8. asynchronous machine speed figure 9. mechanical power of synchronous machine e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 42 in addition, it can be seen that at the time of the error, the output voltage dropped to about 0.2 pu and the excitation voltage was limited to 6 pu. after eliminating the error, the mechanical power is figure 10. synchronous machine speed figure 11. synchronous machine output voltage figure 12. synchronous and diesel machine control signal e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 43 rapidly increases to 1 pu and stays stable at 0.8. after 3 seconds, the terminal voltage becomes stable close to the reference voltage. b. load distribution in oscillating machine mode in this section, the load distribution has been done with two machines that use the asynchronous machine as a reference instead of the induction source that leads to the required absorbed power or leads to generate to estimate the active generated power by other components and the power consumed. in this case, but without the proposed controller, load distribution is not done in a sustainable state. so system outputs lose their lasting status and load distribution appears at the low-quality output. in this case, the output of the system is shown in figure 13. after entering the diesel controller, the voltage terminal is set to 24985 volts, which is the amount of earlier load distribution of the bus 1. after modeling the new mode, the machines parameters obtained are tabulated in table 4. as expected, in figure 14, the results are similar to the previous state and the active power delivered by the oscillating bus is 7.04 mw. the difference of 0.03 mw is equivalent to transformer losses. figure 15 and figure 16 demonstrate the control signal of the proposed controller and the output voltage of the system. the same is true for the frequency output in figure 17, and it can be seen that the frequency does not cause severe system malfunction at the time of the error and continues steadily up to the 60 hz frequency range. in figure 18, according to the ieee standard, the harmonic percentage value for our desired output is tolerable up to 5 %. table 3. voltages and currents parameters of non-linear blocks nonlinear elements system outputs system inputs 'u_circuit breaker/breaker a ' = 0.67 v 3.20° 'i_circuit breaker/breaker a ' = 67.02 a 3.20° 'u_circuit breaker/breaker b ' = 0.67 v -116.80° 'i_circuit breaker/breaker b ' = 67.02 a -116.80° 'u_circuit breaker/breaker c ' = 0.67 v 123.20° 'i_circuit breaker/breaker c ' = 67.02 a 123.20° 'u_three-phase to ground fault/fault a' = 20400.16 v -0.40° 'i_three-phase to ground fault/fault a ' = 0.00 a 0.00° 'u_three-phase to ground fault/fault b' = 20400.16 v -120.40° 'i_three-phase to ground fault/fault b ' = 0.00 a 0.00° 'u_three-phase to ground fault/fault c' = 20400.16 v 119.60° 'i_three-phase to ground fault/fault c ' = 0.00 a 0.00° 'u_ab: synchronous machine 3.125 mva ' = 3394.11 v -1.57° 'i_a: synchronous machine 3.125 mva ' = 325.34 a -90.05° 'u_bc: synchronous machine 3.125 mva ' = 3394.11v-121.57° 'i_b: synchronous machine 3.125 mva ' = 325.34 a 149.95° 'u_ab: asynchronous machine 2250 hp ' = 3394.11v-1.57° 'i_a_stator: asynchronous machine 2250 hp' = 556.11 a -53.66° 'u_bc: asynchronous machine 2250 hp ' = 3394.11v -121.57° 'i_b_stator: asynchronous machine 2250 hp' = 556.11 a -173.66° figure 13. synchronous and diesel machine control signal (oscillation mode in the absence of the proposed controller for diesel) e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 44 figure 14. shapes of mechanical power, controller output signal, output voltage and synchronization machine speed (oscillation mode with the proposed controller for diesel) figure 15. control signal of the proposed controller figure 16. output voltage of system e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 45 figure 17. output frequent (a) (b) figure 18. the harmonic diagram: (a) the harmonic diagram of the system currents; (b) the harmonic diagram of the active, reactive, and mechanical power e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 46 iv. conclusion in independent systems, load distribution is generally one of the most important things that must do seriously. in this small independent system, electric machines and other elements which have been mentioned in the earlier sections, transient time error, engine and generator isolation, synchronous machine drive system and the speed controller for keeping voltage and speed at a certain amount, synchronous machine controllers and emergency diesel controllers and simulation results verify the stability of the independent system. at the time of system error, unbalanced in different parts appeared in charts, but with the arrival of the proposed controller, load distribution was done very accurately. also, we saw that the diesel had timely compensated for the deficiencies and that stability and output setting was done accurately by the proposed controller. the harmonic values are hardly possible to reach the lowest values that we were able to obtain these amounts to less than acceptable amount. this system is intended as an independent system and can be applied in practice to the industry. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] wang, rongjie, xiangyu liu, and yuyuan huang. "synchronous generator excitation system for a ship based on active disturbance rejection control," mathematical problems in engineering, 2021. [2] semshchikov, e., hamilton, j., wu, l., negnevitsky, m., wang, x., & lyden, “s. frequency control within high renewable penetration hybrid systems adopting low load diesel methodologies,” energy procedia, 160, 483-490, 2019. [3] moran-rio, diana patricia, et al, "influence of the phase-locked loop on the design of microgrids formed by diesel generators and grid-forming converters," ieee transactions on power electronics, 2021. [4] m. mobarra, m. rezkallah, & a. ilinca, “variable speed diesel generators: performance and characteristic comparison,” energies, 15(2), 592, 2022. [5] m. farrokhabadi, c. a. cañizares, j. w. simpson-porco, e. nasr, l. fan, p. a. mendoza-araya, ... & j. reilly, “microgrid stability definitions, analysis, and examples,” ieee transactions on power systems, 35(1), 13-29, 2019. [6] rodriqeze-calvo, andrea, et al., “evaluating the determinants of the scalability and reliability of islanded operation in medium voltage networks with cogeneration,” in 2015 international symposium on smart electric distribution systems and technologies (edst), pp. 80-87, sept. 2015. [7] k. may, et al., “improving scalability and replicability of smart grid projects,” 23rd international conference on electricity distribution, june, 2015. [8] conti s, rizzo sa, el-saadany ef, essam m, atwa ym, “reliability assessment of distribution systems considering telecontrolled switches and micro-grids,” ieee transactions on power systems. mar, 29 (2), 598-607, 2014. [9] shahgholian g, mahdavian m, ganji e, eshaghpour i, matouri m, janghorbani m, “transient stability enhancement of a twomachine power system using svc and pss: a comparative study,” 2017 14th international conference on electrical engineering/electronics, computer, telecommunications and information technology (ecti-con), nov, pp. 103-106, 2017. [10] report, excitation system models for power system stability studies. ieee transactions on power apparatus and systems. feb (2):494-509, 1981. [11] h. b. tolabi, m. h. ali, m. rizwan, “simultaneous reconfiguration, optimal placement of dstatcom, and photovoltaic array in a distribution system based on fuzzyaco approach,” ieee transactions on sustainable energy, jan, 6(1):210-218, 2015. [12] ji. jadric, d. borojevic, m. jadric, “modeling and control of a synchronous generator with an active dc load,” ieee transactions on power electronics, mar, 15(2), 303-11, 2000. table 4. machines parameters synchronous machine asynchronous machine power: 3.125 mva power: 2250 hp nominal: 3.125 mva 2400 v rms nominal: 1.6785 mva 2400 v rms bus type: p & v generator bus type: asynchronous machine uan phase: -31.57° uan phase: -31.57° uab: 2400 vrms [1 pu] -1.57° uab: 2400 vrms [1 pu] -1.57° ubc: 2400 vrms [1 pu] -121.57° ubc: 2400 vrms [1 pu] -121.57° uca: 2400 vrms [1 pu] 118.43° uca: 2400 vrms [1 pu] 118.43° ia: 230.05 arms [0.306 pu] -90.05° ia: 393.23 arms [0.9739 pu] -53.66° ib: 230.05 arms [0.306 pu] 149.95° ib: 393.23 arms [0.9739 pu] -173.66° ic: 230.05 arms [0.306 pu] 29.95° ic: 393.23 arms [0.9739 pu] 66.34° p: 5e+05 w [0.16 pu] p: 1.5146e+06 w [0.9024 pu] q: 8.1518e+05 vars [0.2609 pu] q: 6.1473e+05 vars [0.3662 pu] pmec: 5.0105e+05 w [0.1603 pu] pmec: 1.492e+06 w [0.8889 pu] torque: 2658.2 n.m [0.1603 pu] torque: 7964 n.m [0.8944 pu] vf: 1.428 pu slip: 0.006119 https://mev.lipi.go.id/ https://doi.org/10.1155/2021/6638370 https://doi.org/10.1155/2021/6638370 https://doi.org/10.1155/2021/6638370 https://doi.org/10.1155/2021/6638370 https://doi.org/10.1016/j.egypro.2019.02.196 https://doi.org/10.1016/j.egypro.2019.02.196 https://doi.org/10.1016/j.egypro.2019.02.196 https://doi.org/10.1016/j.egypro.2019.02.196 https://doi.org/10.1109/tpel.2021.3127310 https://doi.org/10.1109/tpel.2021.3127310 https://doi.org/10.1109/tpel.2021.3127310 https://doi.org/10.1109/tpel.2021.3127310 https://doi.org/10.3390/en15020592 https://doi.org/10.3390/en15020592 https://doi.org/10.3390/en15020592 https://doi.org/10.1109/tpwrs.2019.2925703 https://doi.org/10.1109/tpwrs.2019.2925703 https://doi.org/10.1109/tpwrs.2019.2925703 https://doi.org/10.1109/tpwrs.2019.2925703 https://doi.org/10.1109/sedst.2015.7315187 https://doi.org/10.1109/sedst.2015.7315187 https://doi.org/10.1109/sedst.2015.7315187 https://doi.org/10.1109/sedst.2015.7315187 https://doi.org/10.1109/sedst.2015.7315187 https://ieeexplore.ieee.org/xpl/conhome/7303873/proceeding http://cired.net/publications/cired2015/papers/cired2015_0390_final.pdf http://cired.net/publications/cired2015/papers/cired2015_0390_final.pdf http://cired.net/publications/cired2015/papers/cired2015_0390_final.pdf https://doi.org/10.1109/tpwrs.2013.2287301 https://doi.org/10.1109/tpwrs.2013.2287301 https://doi.org/10.1109/tpwrs.2013.2287301 https://doi.org/10.1109/tpwrs.2013.2287301 https://doi.org/10.1109/ecticon.2017.8096183 https://doi.org/10.1109/ecticon.2017.8096183 https://doi.org/10.1109/ecticon.2017.8096183 https://doi.org/10.1109/ecticon.2017.8096183 https://ieeexplore.ieee.org/xpl/conhome/8085057/proceeding https://ieeexplore.ieee.org/xpl/conhome/8085057/proceeding https://ieeexplore.ieee.org/xpl/conhome/8085057/proceeding https://doi.org/10.1109/tpas.1981.316906 https://doi.org/10.1109/tpas.1981.316906 https://doi.org/10.1109/tpas.1981.316906 https://doi.org/10.1109/tste.2014.2364230 https://doi.org/10.1109/tste.2014.2364230 https://doi.org/10.1109/tste.2014.2364230 https://doi.org/10.1109/tste.2014.2364230 https://doi.org/10.1109/tste.2014.2364230 https://doi.org/10.1109/63.838103 https://doi.org/10.1109/63.838103 https://doi.org/10.1109/63.838103 e. ganji and m. mahdavian / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 36-47 47 [13] h. chen, z. lu, j. ye, s. zhou, “a real shipboard power system and its computer simulation,” in power systems conference and exposition, mar, 15 (pp. 1-7). 2009. [14] k. e. yeager, j. r. willis, “modeling of emergency diesel generators in an 800 megawatt nuclear power plant,” ieee transactions on energy conversion, vol 8, no 3, september, 1994. [15] j. j. justo, f. mwasilu, j. lee, j. w. jung, “ac-microgrids versus dc-microgrids with distributed energy resources: a review,”. renewable and sustainable energy reviews, aug 1, 24, 387405, 2013. [16] a. k. alaboudy, h. h. zeineldin, j. kirtley, “microgrid stability characterization subsequent to fault-triggered islanding incidents,” ieee transactions on power delivery, apr, 27(2), 658-69, 2012. [17] a. h. alaboudy, h. h. zeineldin, j. kirtley, “simple control strategy for inverter-based distributed generator to enhance microgrid stability in the presence of induction motor loads,” iet generation, transmission & distribution, oct, 7(10), 115562, 2013. [18] y. tan, k. m. muttaqi, p. ciufo, l. meegahapola, “enhanced frequency response strategy for a pmsg-based wind energy conversion system using ultracapacitor in remote area power supply systems,” ieee transactions on industry applications, jan, 53(1), 549-58, 2017. [19] r. s. fernandez, “simulation of the transition from wind only mode to wind diesel mode in a no-storage wind diesel system,” ieee latin america transactions, sep, 7(5), 2009. [20] r. kumar, r. singh, and h. ashfaq, “stability enhancement of multi-machine power systems using ant colony optimizationbased static synchronous compensator,” computers & electrical engineering, vol. 83, p. 106589, may, 2020. [21] a. belila, y. amirat, m. benbouzid, e. m. berkouk, and g. yao, “virtual synchronous generators for voltage synchronization of a hybrid pv-diesel power system,” international journal of electrical power & energy systems, vol. 117, p. 105677, may, 2020. https://doi.org/10.1109/psce.2009.4840011 https://doi.org/10.1109/psce.2009.4840011 https://doi.org/10.1109/psce.2009.4840011 https://doi.org/10.1109/60.257056 https://doi.org/10.1109/60.257056 https://doi.org/10.1109/60.257056 https://doi.org/10.1109/60.257056 https://doi.org/10.1016/j.rser.2013.03.067 https://doi.org/10.1016/j.rser.2013.03.067 https://doi.org/10.1016/j.rser.2013.03.067 https://doi.org/10.1016/j.rser.2013.03.067 https://doi.org/10.1109/tpwrd.2012.2183150 https://doi.org/10.1109/tpwrd.2012.2183150 https://doi.org/10.1109/tpwrd.2012.2183150 https://doi.org/10.1109/tpwrd.2012.2183150 https://doi.org/10.1049/iet-gtd.2013.0024 https://doi.org/10.1049/iet-gtd.2013.0024 https://doi.org/10.1049/iet-gtd.2013.0024 https://doi.org/10.1049/iet-gtd.2013.0024 https://doi.org/10.1049/iet-gtd.2013.0024 https://doi.org/10.1109/tia.2016.2613074 https://doi.org/10.1109/tia.2016.2613074 https://doi.org/10.1109/tia.2016.2613074 https://doi.org/10.1109/tia.2016.2613074 https://doi.org/10.1109/tia.2016.2613074 https://doi.org/10.1109/tla.2009.5361191 https://doi.org/10.1109/tla.2009.5361191 https://doi.org/10.1109/tla.2009.5361191 https://doi.org/10.1016/j.compeleceng.2020.106589 https://doi.org/10.1016/j.compeleceng.2020.106589 https://doi.org/10.1016/j.compeleceng.2020.106589 https://doi.org/10.1016/j.compeleceng.2020.106589 https://doi.org/10.1016/j.ijepes.2019.105677 https://doi.org/10.1016/j.ijepes.2019.105677 https://doi.org/10.1016/j.ijepes.2019.105677 https://doi.org/10.1016/j.ijepes.2019.105677 https://doi.org/10.1016/j.ijepes.2019.105677 introduction ii. materials and methods a. synchronous machine block b. diesel block and its controller c. diesel engine model d. asynchronous machine parameters iii. results and discussions load distribution in non-oscillating machine mode b. load distribution in oscillating machine mode iv. conclusion declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.201-213 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: t.d atmaja et al., “component degradation and system deterioration: an overview of early termination of pv-dg microgrid system,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 201-213, dec. 2022. component degradation and system deterioration: an overview of early termination of pv-dg microgrid system tinton dwi atmaja a, b, c, dalila mat said a, c, *, sevia mahdaliza idrus a, c, ahmad fudholi b, d, nasarudin ahmad a, dian andriani e, f, ahmad rajani a, b, c, sohrab mirsaeidi g, haznan abimanyu h a faculty of electrical engineering, universiti teknologi malaysia block p19a, utm johor campus, johor bahru, 81310 johor, malaysia b research centre for energy conversion and conservation, national research and innovation agency kawasan bandung cisitu, jl. sangkuriang, dago, coblong, bandung, 40135, indonesia c centre of electrical energy system, institute of future energy, utm block p19a, level 1, utm johor campus, johor bahru, 81310 johor, malaysia d solar energy research institute, universiti kebangsaan malaysia level g research complex, universiti kebangsaan malaysia, 43600 bangi, selangor, malaysia e faculty of civil engineering, universiti teknologi malaysia block m46, utm johor campus, johor bahru, 81310 johor, malaysia f research organization for life sciences & environment, national research and innovation agency cibinong science center, jl. raya jakarta-bogor, cibinong, bogor, jawa barat 16915, indonesia gschool of electrical engineering, beijing jiaotong university x82w+h2f, jiaoda e rd, beixiaguan subdistrict, haidian district, beijing100082, china h research organization for energy and manufacture, national research and innovation agency gedung manajemen puspiptek, gedung 720, jl. puspitek, tangerang selatan, banten 15314, indonesia received 17 november 2022; revised 14 december 2022; accepted 15 december 2022; published online 29 december 2022 abstract degradation of components and system failure within the microgrid system is deteriorating the performance of electrification. the aim of this study is to discuss the relationship and connections between issues resulting from degradation and deterioration in the microgrid system, in addition to introducing the prominent impacts which may eventually lead to the premature termination of the microgrid system. this study explored the microgrid degradation and deterioration issues within four microgrid sections: generation section, storage section, transmission section, and distribution section. subsequently, this study analyzes, derives, and classifies all emerging issues into four types of prominent impacts. the degradation and deterioration invoked many component performance issues into four main damaging outcomes, namely (i) deteriorated transmission line yielded issues regarding expected energy not achieved; (ii) energy deficit and unpredicted blackout come after the depth of discharge (dod) reduction and invoke a loss of power supply; (iii) a shorter battery life cycle, shorter transformer lifespan, and decreased dg lifetime concluded as a shorter microgrid life expectancy; and (iv) rapid microgrid broke down and the crash of the key component inadvertently fastened the time to failure and gave rise to the early failure of a microgrid system. it is envisaged that the discussion in this study can provide useful mapped information for the researcher, stakeholder, operator, and other parties for thoroughly addressing various degradation and deterioration issues and anticipating the early termination of the microgrid system. ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: early failure; expected energy not achieved; loss of power supply; microgrid termination; shorter lifespan. i. introduction renewable electrification is one of the trending research projects to provide affordable, reliable, sustainable, and modern energy for all communities [1], as many countries are moving toward the * corresponding author. tel: +60 19 427 8761 e-mail address: dalila@utm.my https://dx.doi.org/10.14203/j.mev.2022.v13.201-213 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.201-213 https://dx.doi.org/10.14203/j.mev.2022.v13.201-213 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.201-213&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 202 highest possible electrification ratio using renewable sources [2]. it is highly inevitable that the higher the electrification, the more poverty can be reduced, especially in developing countries [3]. electrification projects are not only conducted in urban areas aiming for higher energy efficiency [4][5] but also applied in rural areas [6][7]. thereof, a lot of microgrid projects have been initiated and conducted in both rural and urban areas [8]. there are usually four sections in a microgrid: generation, storage, transmission, and distribution. a number of previous studies discussed how each section could be improved. for example, increasing the power production [9][10], intensifying storage unit [11][12][13], optimizing transmission line [14][15][16], and improving distribution network [17][18][19]. it is commonly known that microgrid reliability is a trend in the publication, which is focused on enhancing the microgrid performance [20][21] or optimizing the configuration [22][23][24] and technological choice [25][26]. research [3] tried to enhance the stability of the generation section performance using proper design and planning, while research [20] tried to enhance the performance at the energy source section using scheduling and upgrading. study [22] optimized configuration and sizing, while [23][24][27] see the optimization of redesigning techno-economic aspects. the approach in [25] focused on technological choice, while [26] focused on topological configuration. however, microgrid installations are occasionally followed by unique challenges both in the technical and social aspects [28]. for example, lower energy production than the expected level [29][30], expected energy not achieved [31][32], loss of power [33][34], etc. it is expected that technical issues were inaudibly disrupting the microgrid, which led to the deterioration of the microgrid and finalized with failure of the microgrid [35][36]. microgrid failure has been studied previously by many institutions around the globe. aside from system failure because of force majeure [37][38][39], microgrid failure usually starts at the operational condition level (such as unbalanced voltage [40][41]), followed by loss of power or thermal increase in the system [42], and finalized by component reliability decreased performance [43]. if the reliability reductions are not recovered, the microgrid system will completely fail, and termination is unavoidable. the basics of microgrid failure were studied based on two main grounds, i.e., component degradation and system deterioration. the component degradation model has been long developed to predict the component time to failure based on critical environmental conditions [44][45]. some studies are also concerned about component degradation which was based on the component’s active disconnection among improper topology, which triggers a multi-state flow failure [46]. in a power plant with a rotating component, such as a wind farm, a worn-out component is a common cause of failure [47][48]; for example, the turbine gearbox. deteriorated sections were commonly channeled in the storage section and transmission section. the network joint and grid connection has become the continuous attention of the researcher [49][50] they were vulnerable to deterioration and followed by reduced transmitted energy in the transmission line. as mentioned, microgrid termination is a possible event targeting underperformed microgrids which are predicted to have more disadvantages than practical benefits. microgrid termination is also one of the schemes for smart grid implementation [51]. still and all, an underperforming microgrid was never designed in the first place but came in midoperation because of the occurrence of component degradation and system deterioration. when the key component of the microgrid has deteriorated, it will be easily concluded that the microgrid shall face its early termination. previous research [52][53] developed an early warning system to anticipate early microgrid failure. nevertheless, it will be beneficial to learn how the failure is triggered and anticipate them long before the component degradation and deterioration occur. furthermore, both the researcher and the operator tend to occasionally neglect the potential degradation and deterioration aspect of the microgrid sections themselves, whereas the impact of their negligence would be an early termination of the microgrid system. if there is any paper with a discussion on microgrid-degradation topic [54][55][56], they are focused on one section of the microgrid, which omits the connection between entire microgrid sections. this study should combine the degradation from all sections into one framework scenario. based on the aforementioned issue, this paper aims to highlight the emerging issues related to degradation and deterioration in the whole microgrid sections, classify the degraded and deteriorated parameters, and correlate the parameters to one another. this paper shall provide a broad concept of microgrid degradation and deterioration based on the critical impact of each emerging issue. the information gathered in this work hopefully will contribute as: 1. valuable information for researchers, practitioners, designers, decision-makers, and stakeholders to be aware of the degradation and deterioration in sections of the power system. 2. a convenience assistant for microgrid operators/management to update their knowledge that collaborated degradation issues have a significant impact on the reduction of microgrid performance. 3. a thorough guideline on identifying and addressing the degradation deterioration issue and hopefully prevent the early termination of the microgrid system. in order to address those termination challenges, section 2 defines the methodology used in this study, section 3 provides a thorough systematic exploration of component degradation and system deterioration, and finally, section 4 discusses critical t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 203 impacts derived from degradation and deterioration issues, as well as explain the collaborative scheme between issue’s domains. ii. methodology this study conducts a thorough exploration of the electrification system, which is more presented in a microgrid system. the observation was made through literature studies across every aspect with potential degradation and deterioration inside the microgrid system. a. exploratory on microgrid system the exploration of the electrification system is expressed in an overview shown in figure 1. the electrification was established in a microgrid system which contained the generation section, storage section, transmission section, and ended up in a distribution system. the deterioration happened in every section of the microgrid and potentially affected one section to another. this study collaborates the potential impact between sections where the final consequence should be a termination of the whole microgrid system. b. analysis of potential impact of component degradation & performance deterioration the analysis of the potential impact has been done based on two main roots; component degradation and system deterioration. these predicaments drive a lot of notable issues within the microgrid; for example, the occurrence of rising temperature, increased voltage, reduction of dod, and so on. degradation and deterioration problems brough out particular emerging issues at the component level (figure 2). the complex emerging issues decreased the microgrid component’s performance and then brought forth the prominent impacts. there are four notable impacts in this study. • expected energy not achieved (eena); the degradation and deterioration not only reduce the generation section but also alter the transmission line. this issue resulted in lower transmitted energy than expected. • loss of power supply probability (lpsp) is a significant parameter to evaluate the reliability of the microgrid. the smaller the lpsp, the higher the reliability. the degraded storage unit electrification system transmis sion section generation section storage section distributrion section figure 1. general overview of the electrification system component degradation system deterioration decreased component performances early microgrid failure expected energy not achieved loss of power supply shorter life expectancy established problems emerging issues potential impact early termination of microgrid project outcome figure 2. potential impact scenario from the degradation and deterioration within the microgrid system t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 204 is the most impacted unit, which led to the loss of power supply. • shorter life expectancy: each component has been restricted to a certain manner, which concurs with the deterioration of its life expectancy. not only in the generation section, but the storage section is also quite a sensitive section with a lot of potential reduction in lifespan. • early microgrid failure; each issue eventually led to an early component failure and then followed by a system breakdown. these component issues impacted on an earlier microgrid failure than a normal prediction. thereof, the initial prediction is no longer reliable. this study discussed the degradation and deterioration as the main reason for the reduction of microgrid lifespan. however, the termination of the microgrid system is evidently stimulated by many issues. therefore, this study added several significant issues aside from those four, which are believed to unavoidably lead the microgrid into an early termination. c. constraints and limitations the single-generation mode using pv is the favorite microgrid setup in urban areas; however, when it comes to rural areas, pv-dg is the most considered microgrid setup [22][57]. therefore, this study focuses on pv-dg setup, which can represent both urban and rural areas. it is also because data on pv readiness to comply with dg are more wellfounded [58][59]. even though the pv-dg microgrid has been used in previous research [60][61][62], the previous more focused on component optimization but did not thoroughly analyze the deterioration factor. it has been recently underlined that microgrid management is not only about the technical issue but also considering non-technical matters such as social (e.g., community involvement or stakeholder issues), economics (e.g., levelized cost of electricity or funding issues), local policy (e.g., incentives or investment policies issues), etc. [28][63]. however, this work only focused on the technical-related issue of correspondence to the degradation of the component and deterioration of the system within the power system area. since the issues regarding microgrid deterioration have emerged in the last decade, this work is mainly considering ten years of literature sources with several minor additions to the 20-year literature for specific matter discussion. hence, it is expected that the topic discussed in this work is upto-date enough with the current condition of the electrification system. since this study is overviewing the cause and framing the termination of the microgrid system, this study is not discussing any issue related to the microgrid optimization process. instead, this study provided thorough qualitative information about the impact of component deterioration on microgrid performance. iii. component degradation and system deterioration microgrid components usually come with a specific datasheet containing their operating condition in correspondence with the operating cycle. default handling was provided with the manufacturer’s experimental curve that expresses the nominal loss of performance on a certain operating cycle. for example, on the battery’s product handling, it usually is provided with the dod curve related to the operating cycle. this curve was created under a controlled environment and was supposed to be anticipated for the approximation of real environment value difference. the value difference comes due to the real operation, such as charging or discharging on the battery or displacement damage by the surrounding shell on the photovoltaic module. the real environment value may differ from the test value. this varying value could be related to the weather condition, impact on the grid structure, robust control, or strange load behavior [64]. nevertheless, it is unavoidable to have component degradation as well as system deterioration. system performance deterioration is usually led by component degradation [65]. however, system deterioration may be invoked by other factors, such as human error or amiss maintenance. this section explores component degradation and system deterioration based on the recent decade of literature and research. a. component degradation each component ordinarily reduced its performance and affected the expected quality of the microgrid. for example, figure 3 shows how photovoltaic cells were degraded along the operational process [66]. each product has its own curve based on its materials and the system configuration. table 1 contains the literature survey on previous research related to the degradation of the microgrid component. it can be analyzed that the performance of the microgrid component is not merely based on the default datasheet. the uncontrolled environment value affected the initially predicted performance reduction and degraded faster. table 1 shows the most visible degradation in the generation and storage sections. improper design and installation of a pv module were followed by unexpected degradation and led to lower energy generation [67][68]. in the dg domain, unmanaged working time was found to be alarmed by the life cycle reduction and deficiency of energy supply [69][70]. otherwise, the degradation comes from the amiss configuration of the dg itself, especially the cnc configuration [71]. battery coupling with the grid was detected as one of many reasons for the occurrence of voltage spikes and temperature rise [72][73]. it also led to discharge activity anomaly, which degraded the dod even faster. without proper connection, the load requests a supply of energy with an unstable pattern, which invokes the improper charge and discharge t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 205 sequence, even more, triggers an impulsive selfdischarge [74][75]. these events triggered dod reduction [76]. once the reduction of batteries and the photovoltaic module has occurred, the other microgrid component will start failing. microgrid management should directly address any key component malfunction to make sure that early microgrid failure is not happening. b. system deterioration each component has not only degraded but also deteriorated because of the operational process in its continuous cycle. for example, figure 4 shows how two battery modules deteriorated during the operational cycle [80]. each system has a particular component with distinct characteristics. those two battery modules were supposed to be having a clean degradation curve, but instead, they have a fluctuated deteriorated curve which perpetually decreases more than the predicted value. moreover, table 2 contains the literature survey on previous research related to system deterioration. distinctively operate than component degradation, table 2 shows that system deteriorations happened more at transmission line and distribution network. the deteriorations were similarly begun at the design and installation stage, where the network topology and grid architecture slightly affect the transmitted energy. it is found that several transmission disturbances were triggered by improper design of topology and architecture [81][82]. figure 3. example of degradation curves on various pv cells (modified from ref. [66]) table 1. degradation summary to introduce the decreased microgrid performance ref degradation scheme degradation issues classification [67] pv module degradation leads to lower energy generation degradation in the photovoltaic expected energy not achieved [68] pv-battery improper design degradation on generation section expected energy not achieved [69] a high amount of working time with a low energy supply shorter battery life cycle shorter unit lifespan [70] long period operational on dg section energy production deterioration expected energy not achieved [71] amiss configuration on the dg section led to deteriorated dg energy production below expectation expected energy not achieved [72] the occurrence of high voltage led to dod degradation energy deficit is detected loss of power supply [73] high temperature and high voltage lead to unit damage early unit replacement affects the economic consideration shorter unit lifespan [74] unexpected self-discharge in the storage section deficiency of energy supply loss of power supply [75] improper charge-discharge sequence reduction of dod loss of power supply [76] battery capacity reduction reduction of dod loss of power supply [77] degradation of the key component, such as the battery or inverter early failure of the key component early microgrid failure [78] cycle reduction on the storage section degradation of the storage section loss of power supply [79] electrochemomechanical degradation reduced performance on dg section expected energy not achieved t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 206 a transmission line design without considering the surrounding environment was found with an unexpected nuisance, e.g., component corrosion [83], overloading load [83], out of range working frequency [84], or underrated coupling between grid networks [85]. most of these disturbances were led to expected energy not achieved and loss of power supply. a shorter lifespan potentially happens to sensitive components such as sensors along the transmission line. unmanaged activities will lead to an accumulated loss of power and result in an unpredicted blackout. without proper maintenance, the line and the network shall fail and require an unnecessary re-design [86][87]. c. other performance reduction factor it is agreeable that the failure of the microgrid system is not only because of degradation and deterioration. table 3 shows other potential factors that trigger performance reduction and lead to the early failure of the microgrid system. most of this subsection discusses the interference which comes from outside the microgrid domain. for instance, a microgrid connection with the main utility grid demands a proper fault connection because both the main grid and microgrid compensate each other with distinct characteristics. once the compensation process is not properly conducted, the loss of power supply is conducted and followed with expected energy not transmitted [90][91]. other unpredicted disturbances come from the human aspect. within the microgrid area, human errors usually emerge without warning but have a tremendous impact. whether it is an instant impact, such as the immediate failure of the equipment or is long deteriorated system, such as mishandling the worn-out component [92]. from outside the microgrid, the long-distance operator sometimes causes a ruckus in the cyber setting of the microgrid and disturbs the transmission line or distribution network [93][94]. figure 4. example of capacity deterioration curves on two battery modules during. (modified from ref. [80]) table 2. system deterioration survey to emerge the reduction of system performance ref deterioration scheme deterioration issues classification [81] transmission network architecture improperly developed the network has deteriorated, and the transmission is disturbed expected energy not achieved [82] network topology set forth a degenerated transmission line the network has deteriorated, and the transmission is disturbed expected energy not achieved [83] unavoidable corrosion on microgrid component deterioration in the generation section and transmission line loss of power supply [83] overloading at the transformer unit deterioration of transformer lifespan shorter unit lifespan [84] improper working frequency reduced dg lifespan shorter unit lifespan [85] the transmission line setting cannot hold the voltage sensor threshold a deteriorated sensor in the transmission line expected energy not achieved [86] loop frequency led to dg failure energy production is disturbed expected energy not achieved [87] unmanaged loss of power or blackout accumulated blackout deteriorated the component loss of power supply [88] inapt cnc configuration within transmission and distribution line the energy transmission has deteriorated expected energy not achieved [89] insufficient maintenance schedule deteriorated component early microgrid failure t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 207 the last significant impact comes from the policy sector, whether it is concerning the policy at the beginning of the microgrid project or the ongoing policy for the continuous operation of the microgrid [95][96][97]. the policy maker could be the stakeholder, the donors, or probably the local governing body. those policies will determine how much a proper design and installation can be done. they also determine how long the continuity of microgrid operation can be held. if the policies no longer support it, the microgrid will eventually terminate [98][99]. iv. the impact on performance reduction of the microgrid system each component of a microgrid system has a distinctive performance characteristic. they also have a certain factor that gives uncertain stresses over time. these stresses can be in any form, such as high temperature, improper joint, high usage rate, improper discharge, etc. beyond datasheet coverage, the stress has increased the degradation value of the component and decreased the component performance as well. figure 5 shows how the increased degradation brought down the performance value of the microgrid component [65]. at some point, after continuous deterioration and degradation, the component performance will fall beyond the tolerable performance threshold. once the component performance is beyond the performance threshold, potential issues such as expected energy not achieved, loss of power supply, shorter life expectancy, and early microgrid failure will emerge. each issue impacted the microgrid system, as discussed in the following sub-section. a. expected energy not achieved the expected energy is given as an index to measure the minimum amount of required energy produced by the generation section. however, a lot of issues come up in the transmission section, which reduces the transmitted energy. in the generation section, pv production is not achieved mostly because of device degradation [67] which raises the index of expected energy not generated (eeng). aside from the pv, the diesel generator was also acknowledged to have eeng [71] because of the degradation caused by amiss dg element configuration. the expected energy is not achieved only because of the generation section but potentially also because of the delivery section. expected energy not produced (eenp) mostly happened in the transmission line and, in most cases, was derived from the eenp case. research by [71] contains one discussion about the failure to achieve the expected energy because of the performance deterioration of the transmission line. transmission line setting constraints such as thermal limit or voltage threshold detection was also the potential trigger for an eenp [85]. research by [91] showed that an improper design of the transmission network invokes the potential table 3. other factors thazt lead to the failure of the microgrid system ref reduction scheme reduction issues classification [90] grid connection cannot compensate for the microgrid fault the microgrid lost the power support loss of power supply [91] the transmission line setting is not properly conducted energy supply disturbance expected energy not achieved [92] human error in dg operation led to dg failure energy production is disturbed expected energy not achieved [93] the cyber failure led to a fault in the transmission line disturbance on the transmission network expected energy not achieved [98] unsupportive policy on item procurement acquiring a low-quality item early microgrid failure performance threshold component performance d eg ra da tio n va lu e pe rf or m an ce va lu e figure 5. the impact of increased degradation value on the decreased performance value of the microgrid system (modified from ref. [65]) t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 208 expected energy not supplied (eens). an architecture of a transmission line could deliver the generated energy but face a loss of power along the transmission line, and the delivered energy is slightly below the expected threshold. in other research by [81][82], topology degeneration also induced expected energy not transmitted (eent). research by [93] confirmed that cyber failures and information transmission faults lead to an occurrence of 5.7 % expected energy not supplied (eens) error. moreover, inapt cnc configuration generated up to 70 mw eens per year [88]. figure 6 mapped the connection between each issue with the potential expected energy disturbance. all the eeng, eenp, eent, and eens will come to eena with uncertain time exposure. the unattended eena later be followed by possible early failure of the microgrid. b. loss of power supply high voltage was turned up as one of the roots of power loss. whether it directly invokes energy deficit in the transmission line or the distribution network, high voltage surely could also induce a 25 % battery dod degradation [72]. battery deterioration itself can directly cause a loss of power, influence an energy deficit, and subsequently trigger a loss of power. another account that generates an energy deficit is self-discharge [74]. self-discharge was an unpredicted event that happened in an unpredicted time that caused a continuous deficit of the power supply until it went beyond the minimum tolerable threshold [100]. another study also found that the reduction of dod was triggered by the increase in the use of battery units, the unpreserved rising temperature, and an improper charge-discharge sequence. those issues shall later introduce the loss of power on the distribution level [75]. moreover, corrosion was also listed as the cause of the battery deterioration, which surely reduced the supply of power to the transmission line [83]. figure 7 resumes the loss of power supply which comes from the failure of the transmission line and the significant reduction of the storage unit. under a high ratio loss of power, the microgrid could fail before time and the supplied energy to the user will be instantly stopped. for the on-grid microgrid system, the grid connection fault is the primary reason for the loss of inapt cnc configuration setup information transmission faults expected energy not achieved cyber failure eens improper transmission network eent eenp pv module degradation undersized meshed connection eeng dg element configuration transmission line degradation transmission constrain setting figure 6. the schematic overview on the emerging issue of expected energy not achieved loss of power unpredicted blackout unshaved peak load demand energy deficit increase of use reduced supply of power deteriorated pv module rising temperature self discharge failed connection with the main utility grid failing support system corrosion high voltage improper charge discharge controller reduction of dod figure 7. the schematic overview of the emerging issue of power loss t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 209 power [90]. the on-grid microgrid usually depends on the utility grid to cover the energy deficit. however, when a significant fault disturbance happened, the connection was supposed to supply proper energy to the microgrid. however, when the ride-through instrument fails to connect, the microgrid shall lose its power. lastly, peak load shaving is giving a significant effect on preventing blackouts. without proper peak shaving management, an unpredicted high peak load can trigger an unpredicted blackout and lead to a total loss of power [87]. c. shorter life expectancy it’s about the depreciation of energy storage, power generation, and transmission components. the whole microgrid system depends on the surrounding parameter. some areas in which the microgrid was installed could have a lack of energy sources. consequently, some components such as energy storage or gird sensor face a high amount of working time and unexpectedly run out of energy. this scenario led to a shorter life cycle of the component [69]. in other cases, storage units face a continuously rising temperature [73]. high temperatures trigger a component to overheat, followed by a significant performance reduction. moreover, an early unit replacement can be further related to economic losses. it is also known that the reduced battery lifespan was correlated with capacity reduction. as the battery capacity is reduced, the battery lifespan decreases [76]. following that event, the number of dg startups increased in correspondence with the dod of the battery. afterward, the dg lifetime will decrease, and the microgrid lifespan will also be shortened. the working frequency was also one of the grounds which triggered a lot of dynamic stress over the component [84]. each component usually came with a proper range of working frequency. special interference can raise the working frequency over the upper threshold and bring about stress on the component. continuous dynamic stress means that the lifespan of the component would be reduced. overloading and corrosion were found in previous research [83][87], which led to a deteriorated transformer. this condition shall later reduce the transformer lifespan and affect the other section of the microgrid system. a shorter life expectancy of the microgrid component is mapped in figure 8. it is mostly dominated by the wrongdoing at the storage unit, but also because of the reduction at the generation unit. a shorter component lifespan will result in an early failure of the microgrid. d. early microgrid failure the degradation of the key component is always the main reason for early microgrid failure. a degraded key component, such as a deteriorated battery or broken inverter, brings deals to the whole system on the microgrid site [77]. another event that stirred the early microgrid failure was the rapid system breakdown. it is mostly because the component is aging or worn out. previous studies mentioned that insufficient maintenance mostly leads to worn-out and aging components [89][98]. local policies could also come as a challenge. for example, forced policy to apply the local content can coerce the under-standard local component or poorquality nearby component. both types of components will trigger the rapid system breakdown and failure of the key component [94]. figure 9 concludes the early failure of the microgrid system. the previous disturbance comes as a broken, aging, or worn-out component. those will lead to the system breaking down and then the microgrid shall be out of function. early termination will be an immediate consideration. shorter microgrid’s life expectancy unexpectedly run out of energy missed maintenance schedule too high working frequency high dynamic stress on the component limited supply of power corrosion decreased dg lifetime shorter battery life cycle increased dg startup high amount of working time rising temperature overloading shorter transformer life span figure 8. the schematic overview of the emerging issue of shorter life expectancy t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 210 e. open issues on early termination of microgrid system it is agreeable that all four microgrid issues directed the reasoning for the termination of the said microgrid. when the expected energy on the transmission line is not achieved, the primary objective of the microgrid will be in question, and the distribution network will soon decide to consider other electrification systems. when a loss of power continuously happens, the record of unmet load will be accumulated. significant accumulation will be considered as a potential material for an early microgrid termination. after a shorter life expectancy on the microgrid component is predicted, the economic calculation will weigh the cheaper alternative. an expensive microgrid operation will call out an early project termination. and finally, if an early failure is convincingly forecasted, the community and the stakeholder should consider early action of no longer continuing the microgrid project and focus on the potential alternative electrification system. it has become notable that the discussed issues, which are capable of introducing degradation and deterioration, should be addressed immediately. future work should be initiated to anticipate those four domains. however, besides those four domains, there are more factors to study. some factors also include economic analysis, cultural discussion, donor availability, social engagement, community involvement, proper management framework, policy agreement, incentive scheme, continuous funding, and other non-technical domains. v. conclusion component degradation and deterioration within the electrification system pose a threat to the microgrid's performance. furthermore, it can lead to the early termination of the said microgrid. this study addresses the further issues derived from the degradation and deterioration of the electrification system. the degradation and deterioration invoked many component performance issues, which led to four main damaging impacts on the microgrid system. the transmission line was found degradation and deterioration bringing up several issues in the form of eens, eent, eeng, and eenp, which finalized as expected energy not achieved. the energy storage section also addresses the degradation and deterioration with the occurrence of dod reduction issues where energy deficit and unpredicted blackout invoke a prominent loss of power supply. degradation and deterioration additionally come up with shorter lifespan issues which have a lot of attention because its shorter battery life cycle, shorter transformer lifespan, and decreased dg lifetime have resulted in shorter microgrid life expectancy. the last impact is the early failure of the microgrid system. rapid broke down, and the crash of key components inadvertently fastened the time to failure. it is envisaged that the discussion in this study can provide a piece of useful information for the researcher, stakeholder, operator, and others to thoroughly consider the emerging issues of degradation and deterioration to prevent the early termination of the microgrid system. there are still a lot of unexplored emerging issues because of the deterioration and degradation of the microgrid component. it is expected that further study should be conducted to cover more non-technical issues. acknowledgments the authors would like to thank badan riset dan inovasi nasional and universiti teknologi malaysia for facilitating all the data collection and providing sophisticated literature on the completion of this work. the author would also like to thank all the utm lecturers, brin researchers, staff, and students who helped in the accomplishment of this study. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this work was conducted as a part of universiti teknologi malaysia (utm) and badan riset inovasi nasional, early microgrid failure deteriorated battery broken inverter early failure of key components rapid system brokedown aging components under standard component poor quality component wore out components insufficient maintenance unclear operational prochedure figure 9. the schematic overview of the emerging issue of early microgrid failure t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 211 indonesia (brin) collaborative research grant vot r.j130000.7351.4b734. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] united nation, “ensure access to affordable, reliable, sustainable and modern energy,” united nations sustainable development goals, 2015. (accessed aug. 20, 2022). [2] the world bank, “report: universal access to sustainable energy will remain elusive without addressing inequalities,” world bank press release, 2021. (accessed aug. 20, 2022). [3] m. sandelic, s. peyghami, a. sangwongwanich, and f. blaabjerg, “reliability aspects in microgrid design and planning: status and power electronics-induced challenges,” renew. sustain. energy rev., vol. 159, p. 112127, may 2022. [4] t. d. atmaja, r. darussalam, and d. andriani, “vertical facade pv installation to optimize microgrid system on high rise ev parking lot with ac and dc charging station,” in 2017 international conference on sustainable energy engineering and application (icseea), pp. 164–171, oct. 2017. [5] l. martirano, s. fornari, a. di giorgio, and f. liberati, “a case study of a commercial/residential microgrid integrating cogeneration and electrical local users,” in 2013 12th international conference on environment and electrical engineering, pp. 363–368, may 2013. [6] o. babayomi, t. shomefun, and z. zhang, “energy efficiency of sustainable renewable microgrids for off-grid electrification,” in 2020 ieee pes/ias powerafrica, pp. 1–5, aug. 2020. [7] a. ghasemi-marzbali, r. ahmadiahangar, s. g. orimi, m. shafiei, t. haring, and a. rosin, “energy management of an isolated microgrid: a practical case,” in iecon 2021 – 47th annual conference of the ieee industrial electronics society, pp. 1–6, oct. 2021. [8] y.-o. udoakah, e. mudaheranwa, and l. cipcigan, “dynamic modeling of energy consumption pattern of a typical nigerian average urban and rural household for microgrid pv design,” in 2019 ieee pes innovative smart grid technologies europe (isgt-europe), pp. 1–5, sep. 2019. [9] m. effendy, n. mardiyah, and k. hidayat, “efficiency improvement of photovolatic by using maximum power point tracking based on a new fuzzy logic controller,” j. mechatronics, electr. power, veh. technol., vol. 9, no. 2, pp. 57–64, dec. 2018. [10] s. s. reddy and c. yammani, “odd-even-prime pattern for pv array to increase power output under partial shading conditions,” energy, vol. 213, p. 118780, dec. 2020. [11] a. iranmanesh, “intensifying the melting process of a tripletube latent heat energy storage unit via inserting a middle plate into the phase change material container,” j. energy storage, vol. 56, p. 105982, dec. 2022. [12] t. d. atmaja and g. pikra, “absorber layer addition and thermal storage media comparison for concentrated solar power plant optimization,” energy procedia, vol. 32, pp. 74– 83, 2013. [13] e. riyanto et al., “a review of atomic layer deposition for high lithium-ion battery performance,” j. mater. res. technol., vol. 15, pp. 5466–5481, nov. 2021. [14] v. m. gonçalves, e. m. baptista bolonhez, g. e. mendes campos, and l. h. sathler, “transmission line routing optimization using rapid random trees,” electr. power syst. res., vol. 194, p. 107096, may 2021. [15] v. rexhepi and p. nakov, “condition assessment of power transformers status based on moisture level using fuzzy logic techniques,” j. mechatronics, electr. power, veh. technol., vol. 9, no. 1, pp. 17–24, jul. 2018. [16] m. abasi, a. rohani, f. hatami, m. joorabian, and g. b. gharehpetian, “fault location determination in threeterminal transmission lines connected to industrial microgrids without requiring fault classification data and independent of line parameters,” int. j. electr. power energy syst., vol. 131, p. 107044, oct. 2021. [17] z. li, h. wang, q. ai, and y. zhang, “interactive optimization between active distribution network with multi-microgrids based on distributed algorithm,” energy reports, vol. 6, pp. 385–391, dec. 2020. [18] j. gao, j.-j. chen, y. cai, s.-q. zeng, and k. peng, “a two-stage microgrid cost optimization considering distribution network loss and voltage deviation,” energy reports, vol. 6, pp. 263– 267, feb. 2020. [19] e. ganji and m. mahdavian, “improvement of power grid stability and load distribution using diesel excitation controller,” j. mechatronics, electr. power, veh. technol., vol. 13, no. 1, pp. 36–47, jul. 2022. [20] a. younesi, h. shayeghi, z. wang, p. siano, a. mehrizi-sani, and a. safari, “trends in modern power systems resilience: state-of-the-art review,” renew. sustain. energy rev., vol. 162, p. 112397, jul. 2022. [21] a. o. yakub, n. n. same, a. b. owolabi, b. e. k. nsafon, d. suh, and j.-s. huh, “optimizing the performance of hybrid renewable energy systems to accelerate a sustainable energy transition in nigeria: a case study of a rural healthcare centre in kano,” energy strateg. rev., vol. 43, p. 100906, sep. 2022. [22] b. akbas, a. s. kocaman, d. nock, and p. a. trotter, “rural electrification: an overview of optimization methods,” renew. sustain. energy rev., vol. 156, p. 111935, mar. 2022. [23] g. veilleux et al., “techno-economic analysis of microgrid projects for rural electrification: a systematic approach to the redesign of koh jik off-grid case study,” energy sustain. dev., vol. 54, pp. 1–13, feb. 2020. [24] a. haghighat mamaghani, s. a. avella escandon, b. najafi, a. shirazi, and f. rinaldi, “techno-economic feasibility of photovoltaic, wind, diesel and hybrid electrification systems for off-grid rural electrification in colombia,” renew. energy, vol. 97, pp. 293–305, nov. 2016. [25] t. d. atmaja, d. andriani, and r. darussalam, “smart grid communication applications: measurement equipment and networks architecture for data and energy flow,” j. mechatronics, electr. power, veh. technol., vol. 10, no. 2, p. 73, nov. 2019. [26] k. cabana-jiménez, j. e. candelo-becerra, and v. sousa santos, “comprehensive analysis of microgrids configurations and topologies,” sustainability, vol. 14, no. 3, p. 1056, jan. 2022. [27] m. günther, “a hybrid pv-battery/diesel electricity supply on peucang island: an economic evaluation,” j. mechatronics, electr. power, veh. technol., vol. 7, no. 2, pp. 113–122, dec. 2016. [28] international energy agency (iea), “world energy outlook 2021,” 2022. [29] g. xavier de andrade pinto, l. p.costa, h. f. naspolini, and r. rüther, “evaluation of technical feasibility and financial attractiveness of a 1mwp solar photovoltaic generator on ground and building rooftops at the federal university of santa catarina brazil,” in proceedings of the ises solar world congress 2021, pp. 1–12, 2021. [30] s. tabish and i. ashraf, “simulation of partial shading on solar photovoltaic modules with experimental verification,” int. j. ambient energy, vol. 38, no. 2, pp. 161–170, feb. 2017. [31] g. celli, e. ghiani, g. g. soma, and f. pilo, “pseudo sequential monte carlo to plan the integration of res in active distribution networks,” 2011. [32] m. tamoor, m. abu bakar tahir, m. a. zaka, and e. iqtidar, “photovoltaic distributed generation integrated electrical distribution system for development of sustainable energy using reliability assessment indices and levelized cost of electricity,” environ. prog. sustain. energy, vol. 41, no. 4, jul. 2022. [33] m. m. baiek, a. e. esmaio, m. nizam, m. anwar, and h. m. s. atia, “derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses,” j. mechatronics, electr. power, veh. technol., vol. 7, no. 2, pp. 67–76, dec. 2016. [34] r. hou, a. maleki, and p. li, “design optimization and optimal power management of standalone solar-hydrogen system using a new metaheuristic algorithm,” j. energy storage, vol. 55, p. 105521, nov. 2022. [35] s. peyghami, f. blaabjerg, and p. palensky, “incorporating power electronic converters reliability into modern power https://mev.lipi.go.id/ https://www.un.org/sustainabledevelopment/energy/ https://www.un.org/sustainabledevelopment/energy/ https://www.un.org/sustainabledevelopment/energy/ https://www.worldbank.org/en/news/press-release/2021/06/07/report-universal-access-to-sustainable-energy-will-remain-elusive-without-addressing-inequalities https://www.worldbank.org/en/news/press-release/2021/06/07/report-universal-access-to-sustainable-energy-will-remain-elusive-without-addressing-inequalities https://www.worldbank.org/en/news/press-release/2021/06/07/report-universal-access-to-sustainable-energy-will-remain-elusive-without-addressing-inequalities https://doi.org/10.1016/j.rser.2022.112127 https://doi.org/10.1016/j.rser.2022.112127 https://doi.org/10.1016/j.rser.2022.112127 https://doi.org/10.1016/j.rser.2022.112127 https://doi.org/10.1109/icseea.2017.8267703 https://doi.org/10.1109/icseea.2017.8267703 https://doi.org/10.1109/icseea.2017.8267703 https://doi.org/10.1109/icseea.2017.8267703 https://doi.org/10.1109/icseea.2017.8267703 https://doi.org/10.1109/eeeic.2013.6549543 https://doi.org/10.1109/eeeic.2013.6549543 https://doi.org/10.1109/eeeic.2013.6549543 https://doi.org/10.1109/eeeic.2013.6549543 https://doi.org/10.1109/eeeic.2013.6549543 https://doi.org/10.1109/powerafrica49420.2020.9219958 https://doi.org/10.1109/powerafrica49420.2020.9219958 https://doi.org/10.1109/powerafrica49420.2020.9219958 https://doi.org/10.1109/iecon48115.2021.9589801 https://doi.org/10.1109/iecon48115.2021.9589801 https://doi.org/10.1109/iecon48115.2021.9589801 https://doi.org/10.1109/iecon48115.2021.9589801 https://doi.org/10.1109/iecon48115.2021.9589801 https://doi.org/10.1109/isgteurope.2019.8905464 https://doi.org/10.1109/isgteurope.2019.8905464 https://doi.org/10.1109/isgteurope.2019.8905464 https://doi.org/10.1109/isgteurope.2019.8905464 https://doi.org/10.1109/isgteurope.2019.8905464 https://doi.org/10.14203/j.mev.2018.v9.57-64 https://doi.org/10.14203/j.mev.2018.v9.57-64 https://doi.org/10.14203/j.mev.2018.v9.57-64 https://doi.org/10.14203/j.mev.2018.v9.57-64 https://doi.org/10.14203/j.mev.2018.v9.57-64 https://doi.org/10.1016/j.energy.2020.118780 https://doi.org/10.1016/j.energy.2020.118780 https://doi.org/10.1016/j.energy.2020.118780 https://doi.org/10.1016/j.est.2022.105982 https://doi.org/10.1016/j.est.2022.105982 https://doi.org/10.1016/j.est.2022.105982 https://doi.org/10.1016/j.est.2022.105982 https://doi.org/10.1016/j.egypro.2013.05.010 https://doi.org/10.1016/j.egypro.2013.05.010 https://doi.org/10.1016/j.egypro.2013.05.010 https://doi.org/10.1016/j.egypro.2013.05.010 https://doi.org/10.1016/j.jmrt.2021.10.138 https://doi.org/10.1016/j.jmrt.2021.10.138 https://doi.org/10.1016/j.jmrt.2021.10.138 https://doi.org/10.1016/j.epsr.2021.107096 https://doi.org/10.1016/j.epsr.2021.107096 https://doi.org/10.1016/j.epsr.2021.107096 https://doi.org/10.1016/j.epsr.2021.107096 https://doi.org/10.14203/j.mev.2018.v9.17-24 https://doi.org/10.14203/j.mev.2018.v9.17-24 https://doi.org/10.14203/j.mev.2018.v9.17-24 https://doi.org/10.14203/j.mev.2018.v9.17-24 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.ijepes.2021.107044 https://doi.org/10.1016/j.egyr.2020.11.226 https://doi.org/10.1016/j.egyr.2020.11.226 https://doi.org/10.1016/j.egyr.2020.11.226 https://doi.org/10.1016/j.egyr.2020.11.226 https://doi.org/10.1016/j.egyr.2019.11.072 https://doi.org/10.1016/j.egyr.2019.11.072 https://doi.org/10.1016/j.egyr.2019.11.072 https://doi.org/10.1016/j.egyr.2019.11.072 https://doi.org/10.14203/j.mev.2022.v13.36-47 https://doi.org/10.14203/j.mev.2022.v13.36-47 https://doi.org/10.14203/j.mev.2022.v13.36-47 https://doi.org/10.14203/j.mev.2022.v13.36-47 https://doi.org/10.1016/j.rser.2022.112397 https://doi.org/10.1016/j.rser.2022.112397 https://doi.org/10.1016/j.rser.2022.112397 https://doi.org/10.1016/j.rser.2022.112397 https://doi.org/10.1016/j.esr.2022.100906 https://doi.org/10.1016/j.esr.2022.100906 https://doi.org/10.1016/j.esr.2022.100906 https://doi.org/10.1016/j.esr.2022.100906 https://doi.org/10.1016/j.esr.2022.100906 https://doi.org/10.1016/j.rser.2021.111935 https://doi.org/10.1016/j.rser.2021.111935 https://doi.org/10.1016/j.rser.2021.111935 https://doi.org/10.1016/j.esd.2019.09.007 https://doi.org/10.1016/j.esd.2019.09.007 https://doi.org/10.1016/j.esd.2019.09.007 https://doi.org/10.1016/j.esd.2019.09.007 https://doi.org/10.1016/j.renene.2016.05.086 https://doi.org/10.1016/j.renene.2016.05.086 https://doi.org/10.1016/j.renene.2016.05.086 https://doi.org/10.1016/j.renene.2016.05.086 https://doi.org/10.1016/j.renene.2016.05.086 https://doi.org/10.14203/j.mev.2019.v10.73-84 https://doi.org/10.14203/j.mev.2019.v10.73-84 https://doi.org/10.14203/j.mev.2019.v10.73-84 https://doi.org/10.14203/j.mev.2019.v10.73-84 https://doi.org/10.14203/j.mev.2019.v10.73-84 https://doi.org/10.3390/su14031056 https://doi.org/10.3390/su14031056 https://doi.org/10.3390/su14031056 https://doi.org/10.14203/j.mev.2016.v7.113-122 https://doi.org/10.14203/j.mev.2016.v7.113-122 https://doi.org/10.14203/j.mev.2016.v7.113-122 https://doi.org/10.14203/j.mev.2016.v7.113-122 https://www.iea.org/reports/world-energy-outlook-2021 https://www.iea.org/reports/world-energy-outlook-2021 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.18086/swc.2021.17.03 https://doi.org/10.1080/01430750.2015.1074614 https://doi.org/10.1080/01430750.2015.1074614 https://doi.org/10.1080/01430750.2015.1074614 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877263410&partnerid=40&md5=4885a54f2e46c35a386167ddb97981af https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877263410&partnerid=40&md5=4885a54f2e46c35a386167ddb97981af https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877263410&partnerid=40&md5=4885a54f2e46c35a386167ddb97981af https://doi.org/10.1002/ep.13815 https://doi.org/10.1002/ep.13815 https://doi.org/10.1002/ep.13815 https://doi.org/10.1002/ep.13815 https://doi.org/10.1002/ep.13815 https://doi.org/10.1002/ep.13815 https://doi.org/10.14203/j.mev.2016.v7.67-76 https://doi.org/10.14203/j.mev.2016.v7.67-76 https://doi.org/10.14203/j.mev.2016.v7.67-76 https://doi.org/10.14203/j.mev.2016.v7.67-76 https://doi.org/10.14203/j.mev.2016.v7.67-76 https://doi.org/10.1016/j.est.2022.105521 https://doi.org/10.1016/j.est.2022.105521 https://doi.org/10.1016/j.est.2022.105521 https://doi.org/10.1016/j.est.2022.105521 https://doi.org/10.1109/jestpe.2020.2967216 https://doi.org/10.1109/jestpe.2020.2967216 t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 212 system reliability analysis,” ieee j. emerg. sel. top. power electron., vol. 9, no. 2, pp. 1668–1681, apr. 2021. [36] j. peters, m. sievert, and m. a. toman, “rural electrification through mini-grids: challenges ahead,” energy policy, vol. 132, pp. 27–31, sep. 2019. [37] r. k. asyuri and e. a. setiawan, “optimization and integration of renewable energy sources with regional tourism potentials to improve the welfare of local communities,” iop conf. ser. earth environ. sci., vol. 1050, no. 1, p. 012007, jul. 2022. [38] g. dimov, s. tzvetkova, a. petleshkov, and y. lozanov, “change of power supply continuity indices due to force majeure circumstances,” in 2020 12th electrical engineering faculty conference (bulef), pp. 1–5, sep. 2020. [39] q. li, l. wang, and s. hou, “microgrid reliability evaluation based on condition-dependent failure models of power electronic devices,” in 2018 2nd ieee conf. on energy internet and energy system integration (ei2), pp. 1–6, oct. 2018. [40] a. ostrowska et al., “power quality assessment in a real microgrid-statistical assessment of different long-term working conditions,” energies, vol. 15, no. 21, p. 8089, oct. 2022. [41] q. xiao et al., “an improved power regulation method for a three-terminal hybrid ac/dc microgrid during module failure,” int. j. electr. power energy syst., vol. 123, p. 106330, dec. 2020. [42] a. m. nakhaee, s. a. hosseini, s. h. h. sadeghi, and a. nasiri, “a framework for assessing the impact of operational uncertainties on the reliability of adaptive microgrid protection schemes,” arab. j. sci. eng., oct. 2022. [43] w. zhong, l. wang, z. liu, and s. hou, “reliability evaluation and improvement of islanded microgrid considering operation failures of power electronic equipment,” j. mod. power syst. clean energy, vol. 8, no. 1, pp. 111–123, 2020. [44] a. turnbull, j. carroll, and a. mcdonald, “combining scada and vibration data into a single anomaly detection model to predict wind turbine component failure,” wind energy, vol. 24, no. 3, pp. 197–211, mar. 2021. [45] y. h. yang, y. l. xin, j. j. zhou, w. h. tang, and b. li, “failure probability estimation of transmission lines during typhoon based on tropical cyclone wind model and component vulnerability model,” in 2017 ieee pes asia-pacific power and energy engineering conference (appeec), pp. 1–6, nov. 2017. [46] g. wu and z. li, “a cascading failure model of power systems considering components’ multi-state failures,” in 2019 prognostics and system health management conference (phm-qingdao), pp. 1–6, oct. 2019. [47] l. gigoni, a. betti, m. tucci, and e. crisostomi, “a scalable predictive maintenance model for detecting wind turbine component failures based on scada data,” in 2019 ieee power & energy society general meeting (pesgm), pp. 1–5, aug. 2019. [48] m. fischer, s. tenbohlen, m. schafer, and r. haug, “determining power transformers’ sequence of maintenance and repair in power grids,” in 2010 ieee international symposium on electrical insulation, jun., pp. 1–6, 2010. [49] v.-h. bui, a. hussain, and h.-m. kim, “a strategy for optimal operation of hybrid ac/dc microgrid under different connection failure scenarios,” int. j. smart home, vol. 10, no. 12, pp. 231–244, dec. 2016. [50] m. pompili, l. calcara, and s. sangiovanni, “mv underground power cable joints premature failures,” in 2020 aeit international annual conference (aeit), sep. pp. 1–4, 2020. [51] j. weichold, r. calone, i. gentilini, g. bolcato, f. giammanco, and m. stalder, “the smart termination: an innovative component to enable smart grids development,” in 22nd international conference and exhibition on electricity distribution (cired 2013), pp. 0598–0598, 2013. [52] r. zhao, j. chen, z. hou, b. li, m. lin, and m. duan, “a security early warning method of power grid based on failure risk assessment,” in 2021 ieee sustainable power and energy conference (ispec), dec., pp. 1627–1633, 2021. [53] q. yu, z. jiang, y. liu, g. long, m. guo, and d. yang, “research of early warning of failure with load tendency based on nonintrusive load monitoring in microgrid,” in 2020 ieee 6th international conference on control science and systems engineering (iccsse), jul., pp. 232–236, 2020. [54] j. han, l. zhang, and y. li, “hotspots, flaws and deficiencies of research on rural energy upgrading: a review,” energy strateg. rev., vol. 38, p. 100766, nov. 2021. [55] f. gonzalez-longatt, c. adiyabazar, and e. v. martinez, “setting and testing of the out-of-step protection at mongolian transmission system,” energies, vol. 14, no. 23, p. 8170, dec. 2021. [56] p. aaslid, m. korpås, m. m. belsnes, and o. b. fosso, “stochastic operation of energy constrained microgrids considering battery degradation,” electr. power syst. res., vol. 212, p. 108462, nov. 2022. [57] a. yahiaoui, k. benmansour, and m. tadjine, “control, analysis and optimization of hybrid pv-diesel-battery systems for isolated rural city in algeria,” sol. energy, vol. 137, pp. 1–10, nov. 2016. [58] f. fodhil, a. hamidat, and o. nadjemi, “potential, optimization and sensitivity analysis of photovoltaic-dieselbattery hybrid energy system for rural electrification in algeria,” energy, vol. 169, pp. 613–624, feb. 2019. [59] s. m. shaahid and i. el-amin, “techno-economic evaluation of off-grid hybrid photovoltaic–diesel–battery power systems for rural electrification in saudi arabia—a way forward for sustainable development,” renew. sustain. energy rev., vol. 13, no. 3, pp. 625–633, apr. 2009. [60] s. yilmaz and f. dincer, “optimal design of hybrid pv-dieselbattery systems for isolated lands: a case study for kilis, turkey,” renew. sustain. energy rev., vol. 77, pp. 344–352, sep. 2017. [61] h. rezzouk and a. mellit, “feasibility study and sensitivity analysis of a stand-alone photovoltaic–diesel–battery hybrid energy system in the north of algeria,” renew. sustain. energy rev., vol. 43, pp. 1134–1150, mar. 2015. [62] t. d. atmaja et al., “fuel saving on diesel genset using pv/battery spike cutting in remote area microgrid,” matec web conf., vol. 164, p. 01045, apr. 2018. [63] f. almeshqab and t. s. ustun, “lessons learned from rural electrification initiatives in developing countries: insights for technical, social, financial and public policy aspects,” renew. sustain. energy rev., vol. 102, pp. 35–53, mar. 2019. [64] a. qashou, s. yousef, and e. sanchez-velazquez, “mining sensor data in a smart environment: a study of control algorithms and microgrid testbed for temporal forecasting and patterns of failure,” int. j. syst. assur. eng. manag., vol. 13, no. 5, pp. 2371–2390, oct. 2022. [65] y. zhang, j. liu, b. song, and t. yu, “reliability modeling for dependent competing failure processes between component degradation and system performance deterioration,” in safety and reliability – safe societies in a changing world, london: crc press, pp. 2475–2482, 2018. [66] d. l. bätzner, a. romeo, m. terheggen, m. döbeli, h. zogg, and a. n. tiwari, “stability aspects in cdte/cds solar cells,” thin solid films, vol. 451–452, pp. 536–543, mar. 2004. [67] s. g. kumar and k. s. r. k. rao, “physics and chemistry of cdte/cds thin film heterojunction photovoltaic devices: fundamental and critical aspects,” energy environ. sci., vol. 7, no. 1, pp. 45–102, 2014. [68] d. azuatalam, k. paridari, y. ma, m. förstl, a. c. chapman, and g. verbič, “energy management of small-scale pv-battery systems: a systematic review considering practical implementation, computational requirements, quality of input data and battery degradation,” renew. sustain. energy rev., vol. 112, pp. 555–570, sep. 2019. [69] g. liu, y. zhang, f. luo, and j. yuan, “design of wireless sensor network routing for renewable energy microgrid,” iop conf. ser. mater. sci. eng., vol. 366, p. 012022, jun. 2018. [70] y. liu, h. shi, l. guo, t. xu, b. zhao, and c. wang, “towards long-period operational reliability of independent microgrid: a risk-aware energy scheduling and stochastic optimization method,” energy, vol. 254, p. 124291, sep. 2022. [71] y. v. makarov, “probabilistic assessment of the energy not produced due to transmission constraints,” in 2003 ieee bologna power tech conference proceedings, vol. 4, pp. 435– 437, 2003. [72] f. j. v. fernández, f. segura manzano, j. m. andújar márquez, and a. j. calderón godoy, “extended model predictive controller to develop energy management systems in renewable source-based smart microgrids with hydrogen as backup. theoretical foundation and case study,” sustainability, vol. 12, no. 21, p. 8969, oct. 2020. [73] y. garcía-vera, r. dufo-lópez, and j. bernal-agustín, “optimization of isolated hybrid microgrids with renewable energy based on different battery models and technologies,” energies, vol. 13, no. 3, p. 581, jan. 2020. [74] s. kharel and b. shabani, “hydrogen as a long-term largescale energy storage solution to support renewables,” energies, vol. 11, no. 10, p. 2825, oct. 2018. https://doi.org/10.1109/jestpe.2020.2967216 https://doi.org/10.1109/jestpe.2020.2967216 https://doi.org/10.1016/j.enpol.2019.05.016 https://doi.org/10.1016/j.enpol.2019.05.016 https://doi.org/10.1016/j.enpol.2019.05.016 https://doi.org/10.1088/1755-1315/1050/1/012007 https://doi.org/10.1088/1755-1315/1050/1/012007 https://doi.org/10.1088/1755-1315/1050/1/012007 https://doi.org/10.1088/1755-1315/1050/1/012007 https://doi.org/10.1109/bulef51036.2020.9326031 https://doi.org/10.1109/bulef51036.2020.9326031 https://doi.org/10.1109/bulef51036.2020.9326031 https://doi.org/10.1109/bulef51036.2020.9326031 https://doi.org/10.1109/ei2.2018.8582498 https://doi.org/10.1109/ei2.2018.8582498 https://doi.org/10.1109/ei2.2018.8582498 https://doi.org/10.1109/ei2.2018.8582498 https://doi.org/10.3390/en15218089 https://doi.org/10.3390/en15218089 https://doi.org/10.3390/en15218089 https://doi.org/10.3390/en15218089 https://doi.org/10.1016/j.ijepes.2020.106330 https://doi.org/10.1016/j.ijepes.2020.106330 https://doi.org/10.1016/j.ijepes.2020.106330 https://doi.org/10.1016/j.ijepes.2020.106330 https://doi.org/10.1007/s13369-022-07347-7 https://doi.org/10.1007/s13369-022-07347-7 https://doi.org/10.1007/s13369-022-07347-7 https://doi.org/10.1007/s13369-022-07347-7 https://doi.org/10.35833/mpce.2018.000666 https://doi.org/10.35833/mpce.2018.000666 https://doi.org/10.35833/mpce.2018.000666 https://doi.org/10.35833/mpce.2018.000666 https://doi.org/10.1002/we.2567 https://doi.org/10.1002/we.2567 https://doi.org/10.1002/we.2567 https://doi.org/10.1002/we.2567 https://doi.org/10.1109/appeec.2017.8308936 https://doi.org/10.1109/appeec.2017.8308936 https://doi.org/10.1109/appeec.2017.8308936 https://doi.org/10.1109/appeec.2017.8308936 https://doi.org/10.1109/appeec.2017.8308936 https://doi.org/10.1109/phm-qingdao46334.2019.8942818 https://doi.org/10.1109/phm-qingdao46334.2019.8942818 https://doi.org/10.1109/phm-qingdao46334.2019.8942818 https://doi.org/10.1109/phm-qingdao46334.2019.8942818 https://doi.org/10.1109/pesgm40551.2019.8973898 https://doi.org/10.1109/pesgm40551.2019.8973898 https://doi.org/10.1109/pesgm40551.2019.8973898 https://doi.org/10.1109/pesgm40551.2019.8973898 https://doi.org/10.1109/pesgm40551.2019.8973898 https://doi.org/10.1109/elinsl.2010.5549785 https://doi.org/10.1109/elinsl.2010.5549785 https://doi.org/10.1109/elinsl.2010.5549785 https://doi.org/10.1109/elinsl.2010.5549785 https://doi.org/10.14257/ijsh.2016.10.12.22 https://doi.org/10.14257/ijsh.2016.10.12.22 https://doi.org/10.14257/ijsh.2016.10.12.22 https://doi.org/10.14257/ijsh.2016.10.12.22 https://doi.org/10.23919/aeit50178.2020.9241185 https://doi.org/10.23919/aeit50178.2020.9241185 https://doi.org/10.23919/aeit50178.2020.9241185 https://doi.org/10.1049/cp.2013.0826 https://doi.org/10.1049/cp.2013.0826 https://doi.org/10.1049/cp.2013.0826 https://doi.org/10.1049/cp.2013.0826 https://doi.org/10.1049/cp.2013.0826 https://doi.org/10.1109/ispec53008.2021.9735584 https://doi.org/10.1109/ispec53008.2021.9735584 https://doi.org/10.1109/ispec53008.2021.9735584 https://doi.org/10.1109/ispec53008.2021.9735584 https://doi.org/10.1109/iccsse50399.2020.9171952 https://doi.org/10.1109/iccsse50399.2020.9171952 https://doi.org/10.1109/iccsse50399.2020.9171952 https://doi.org/10.1109/iccsse50399.2020.9171952 https://doi.org/10.1109/iccsse50399.2020.9171952 https://doi.org/10.1016/j.esr.2021.100766 https://doi.org/10.1016/j.esr.2021.100766 https://doi.org/10.1016/j.esr.2021.100766 https://doi.org/10.3390/en14238170 https://doi.org/10.3390/en14238170 https://doi.org/10.3390/en14238170 https://doi.org/10.3390/en14238170 https://doi.org/10.1016/j.epsr.2022.108462 https://doi.org/10.1016/j.epsr.2022.108462 https://doi.org/10.1016/j.epsr.2022.108462 https://doi.org/10.1016/j.epsr.2022.108462 https://doi.org/10.1016/j.solener.2016.07.050 https://doi.org/10.1016/j.solener.2016.07.050 https://doi.org/10.1016/j.solener.2016.07.050 https://doi.org/10.1016/j.solener.2016.07.050 https://doi.org/10.1016/j.energy.2018.12.049 https://doi.org/10.1016/j.energy.2018.12.049 https://doi.org/10.1016/j.energy.2018.12.049 https://doi.org/10.1016/j.energy.2018.12.049 https://doi.org/10.1016/j.rser.2007.11.017 https://doi.org/10.1016/j.rser.2007.11.017 https://doi.org/10.1016/j.rser.2007.11.017 https://doi.org/10.1016/j.rser.2007.11.017 https://doi.org/10.1016/j.rser.2007.11.017 https://doi.org/10.1016/j.rser.2017.04.037 https://doi.org/10.1016/j.rser.2017.04.037 https://doi.org/10.1016/j.rser.2017.04.037 https://doi.org/10.1016/j.rser.2017.04.037 https://doi.org/10.1016/j.rser.2014.11.103 https://doi.org/10.1016/j.rser.2014.11.103 https://doi.org/10.1016/j.rser.2014.11.103 https://doi.org/10.1016/j.rser.2014.11.103 https://doi.org/10.1051/matecconf/201816401045 https://doi.org/10.1051/matecconf/201816401045 https://doi.org/10.1051/matecconf/201816401045 https://doi.org/10.1016/j.rser.2018.11.035 https://doi.org/10.1016/j.rser.2018.11.035 https://doi.org/10.1016/j.rser.2018.11.035 https://doi.org/10.1016/j.rser.2018.11.035 https://doi.org/10.1007/s13198-022-01649-7 https://doi.org/10.1007/s13198-022-01649-7 https://doi.org/10.1007/s13198-022-01649-7 https://doi.org/10.1007/s13198-022-01649-7 https://doi.org/10.1007/s13198-022-01649-7 https://doi.org/10.1201/9781351174664-311 https://doi.org/10.1201/9781351174664-311 https://doi.org/10.1201/9781351174664-311 https://doi.org/10.1201/9781351174664-311 https://doi.org/10.1201/9781351174664-311 https://doi.org/10.1016/j.tsf.2003.10.141 https://doi.org/10.1016/j.tsf.2003.10.141 https://doi.org/10.1016/j.tsf.2003.10.141 https://doi.org/10.1039/c3ee41981a https://doi.org/10.1039/c3ee41981a https://doi.org/10.1039/c3ee41981a https://doi.org/10.1039/c3ee41981a https://doi.org/10.1088/1757-899x/366/1/012022 https://doi.org/10.1088/1757-899x/366/1/012022 https://doi.org/10.1088/1757-899x/366/1/012022 https://doi.org/10.1016/j.energy.2022.124291 https://doi.org/10.1016/j.energy.2022.124291 https://doi.org/10.1016/j.energy.2022.124291 https://doi.org/10.1016/j.energy.2022.124291 https://doi.org/10.1109/ptc.2003.1304762 https://doi.org/10.1109/ptc.2003.1304762 https://doi.org/10.1109/ptc.2003.1304762 https://doi.org/10.1109/ptc.2003.1304762 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/su12218969 https://doi.org/10.3390/en13030581 https://doi.org/10.3390/en13030581 https://doi.org/10.3390/en13030581 https://doi.org/10.3390/en13030581 https://doi.org/10.3390/en11102825 https://doi.org/10.3390/en11102825 https://doi.org/10.3390/en11102825 t.d. atmaja et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 201-213 213 [75] n. shirzadi, h. rasoulian, f. nasiri, and u. eicker, “resilience enhancement of an urban microgrid during off-grid mode operation using critical load indicators,” energies, vol. 15, no. 20, p. 7669, oct. 2022. [76] t. m. layadi, g. champenois, m. mostefai, and d. abbes, “lifetime estimation tool of lead–acid batteries for hybrid power sources design,” simul. model. pract. theory, vol. 54, pp. 36–48, may 2015. [77] m. derks and h. romijn, “sustainable performance challenges of rural microgrids: analysis of incentives and policy framework in indonesia,” energy sustain. dev., vol. 53, pp. 57–70, dec. 2019. [78] k. takeno, m. ichimura, k. takano, and j. yamaki, “influence of cycle capacity deterioration and storage capacity deterioration on li-ion batteries used in mobile phones,” j. power sources, vol. 142, no. 1–2, pp. 298–305, mar. 2005. [79] s. zhang, k. zhao, t. zhu, and j. li, “electrochemomechanical degradation of high-capacity battery electrode materials,” prog. mater. sci., vol. 89, pp. 479–521, aug. 2017. [80] y. lv, x. yang, and g. zhang, “durability of phase-changematerial module and its relieving effect on battery deterioration during long-term cycles,” appl. therm. eng., vol. 179, p. 115747, oct. 2020. [81] s. hardy, d. van hertem, and h. ergun, “a techno-economic analysis of meshed topologies of offshore wind hvac transmission,” in 2021 ieee madrid powertech, jun., pp. 1–6, 2021. [82] s. hardy, h. ergun, and d. van hertem, “a greedy algorithm for optimizing offshore wind transmission topologies,” ieee trans. power syst., vol. 37, no. 3, pp. 2113–2121, may 2022. [83] j. m. lujano-rojas, r. dufo-lópez, and j. l. bernal-agustín, “technical and economic effects of charge controller operation and coulombic efficiency on stand-alone hybrid power systems,” energy convers. manag., vol. 86, pp. 709– 716, oct. 2014. [84] p. singh and j. s. lather, “accurate power-sharing, voltage regulation, and soc regulation for lvdc microgrid with hybrid energy storage system using artificial neural network,” int. j. green energy, vol. 17, no. 12, pp. 756–769, sep. 2020. [85] y. v. makarov, r. c. hardiman, and d. l. hawkins, “risk, reliability, cascading, and restructuring,” in ieee power engineering society general meeting, 2004., vol. 2, pp. 383– 395, 2004. [86] a. volkanovski, a. ballesteros avila, and m. peinador veira, “trend analysis of loss of offsite power events,” jun. 2016. [87] d. f. lizondo, v. a. jimenez, p. b. araujo, and a. will, “conceptual microgrid management framework based on adaptive and autonomous multi-agent systems,” j. comput. sci. technol., vol. 22, no. 1, p. e01, apr. 2022. [88] m. hamzeh and b. vahidi, “the impact of cyber network configuration on the dynamic-thermal failure of transformers considering distributed generator controller,” int. j. electr. power energy syst., vol. 137, p. 107786, may 2022. [89] e. c. x. ikejemba, p. b. mpuan, p. c. schuur, and j. van hillegersberg, “the empirical reality &amp; sustainable management failures of renewable energy projects in subsaharan africa (part 1 of 2),” renew. energy, vol. 102, pp. 234–240, mar. 2017. [90] a. m. moheb, e. a. el-hay, and a. a. el-fergany, “comprehensive review on fault ride-through requirements of renewable hybrid microgrids,” energies, vol. 15, no. 18, p. 6785, sep. 2022. [91] s. paul and z. h. rather, “a novel approach for optimal cabling and determination of suitable topology of mtdc connected offshore wind farm cluster,” electr. power syst. res., vol. 208, p. 107877, jul. 2022. [92] d. kančev, a. duchac, b. zerger, m. maqua, and d. wattrelos, “statistical analysis of events related to emergency diesel generators failures in the nuclear industry,” nucl. eng. des., vol. 273, pp. 321–331, jul. 2014. [93] m. aslani, h. hashemi‐dezaki, and a. ketabi, “analytical reliability evaluation method of smart micro‐grids considering the cyber failures and information transmission system faults,” iet renew. power gener., jul. 2022. [94] s. k. akula and h. salehfar, “risk-based classical failure mode and effect analysis (fmea) of microgrid cyber-physical energy systems,” in 2021 north american power symposium (naps), nov., pp. 1–6, 2021. [95] d. akinyele, j. belikov, and y. levron, “challenges of microgrids in remote communities: a steep model application,” energies, vol. 11, no. 2, p. 432, feb. 2018. [96] o. babayomi and t. okharedia, “challenges to sub-saharan africa’s renewable microgrid expansion a cetep solution model,” in 2019 ieee pes/ias powerafrica, aug., pp. 617–621, 2019. [97] d. xu and y. long, “the impact of government subsidy on renewable microgrid investment considering double externalities,” sustainability, vol. 11, no. 11, p. 3168, jun. 2019. [98] s. d. negara, “the impact of local content requirements on the indonesian manufacturing industry,” 2016. [99] d. e. ighravwe and d. mashao, “development of a technoeconomic framework for renewable energy project financing,” in 2019 ieee 2nd international conference on renewable energy and power engineering (repe), nov., pp. 120–124, 2019. [100] y. pu et al., “optimal sizing for an integrated energy system considering degradation and seasonal hydrogen storage,” appl. energy, vol. 302, p. 117542, nov. 2021. https://doi.org/10.3390/en15207669 https://doi.org/10.3390/en15207669 https://doi.org/10.3390/en15207669 https://doi.org/10.3390/en15207669 https://doi.org/10.1016/j.simpat.2015.03.001 https://doi.org/10.1016/j.simpat.2015.03.001 https://doi.org/10.1016/j.simpat.2015.03.001 https://doi.org/10.1016/j.simpat.2015.03.001 https://doi.org/10.1016/j.esd.2019.08.003 https://doi.org/10.1016/j.esd.2019.08.003 https://doi.org/10.1016/j.esd.2019.08.003 https://doi.org/10.1016/j.esd.2019.08.003 https://doi.org/10.1016/j.jpowsour.2004.10.007 https://doi.org/10.1016/j.jpowsour.2004.10.007 https://doi.org/10.1016/j.jpowsour.2004.10.007 https://doi.org/10.1016/j.jpowsour.2004.10.007 https://doi.org/10.1016/j.pmatsci.2017.04.014 https://doi.org/10.1016/j.pmatsci.2017.04.014 https://doi.org/10.1016/j.pmatsci.2017.04.014 https://doi.org/10.1016/j.applthermaleng.2020.115747 https://doi.org/10.1016/j.applthermaleng.2020.115747 https://doi.org/10.1016/j.applthermaleng.2020.115747 https://doi.org/10.1016/j.applthermaleng.2020.115747 https://doi.org/10.1109/powertech46648.2021.9494784 https://doi.org/10.1109/powertech46648.2021.9494784 https://doi.org/10.1109/powertech46648.2021.9494784 https://doi.org/10.1109/powertech46648.2021.9494784 https://doi.org/10.1109/tpwrs.2021.3121017 https://doi.org/10.1109/tpwrs.2021.3121017 https://doi.org/10.1109/tpwrs.2021.3121017 https://doi.org/10.1016/j.enconman.2014.06.053 https://doi.org/10.1016/j.enconman.2014.06.053 https://doi.org/10.1016/j.enconman.2014.06.053 https://doi.org/10.1016/j.enconman.2014.06.053 https://doi.org/10.1016/j.enconman.2014.06.053 https://doi.org/10.1080/15435075.2020.1798767 https://doi.org/10.1080/15435075.2020.1798767 https://doi.org/10.1080/15435075.2020.1798767 https://doi.org/10.1080/15435075.2020.1798767 https://doi.org/10.1109/pes.2004.1372816 https://doi.org/10.1109/pes.2004.1372816 https://doi.org/10.1109/pes.2004.1372816 https://doi.org/10.1109/pes.2004.1372816 https://doi.org/10.1115/icone24-60154 https://doi.org/10.1115/icone24-60154 https://doi.org/10.24215/16666038.22.e01 https://doi.org/10.24215/16666038.22.e01 https://doi.org/10.24215/16666038.22.e01 https://doi.org/10.24215/16666038.22.e01 https://doi.org/10.1016/j.ijepes.2021.107786 https://doi.org/10.1016/j.ijepes.2021.107786 https://doi.org/10.1016/j.ijepes.2021.107786 https://doi.org/10.1016/j.ijepes.2021.107786 https://doi.org/10.1016/j.renene.2016.10.037 https://doi.org/10.1016/j.renene.2016.10.037 https://doi.org/10.1016/j.renene.2016.10.037 https://doi.org/10.1016/j.renene.2016.10.037 https://doi.org/10.1016/j.renene.2016.10.037 https://doi.org/10.3390/en15186785 https://doi.org/10.3390/en15186785 https://doi.org/10.3390/en15186785 https://doi.org/10.3390/en15186785 https://doi.org/10.1016/j.epsr.2022.107877 https://doi.org/10.1016/j.epsr.2022.107877 https://doi.org/10.1016/j.epsr.2022.107877 https://doi.org/10.1016/j.epsr.2022.107877 https://doi.org/10.1016/j.nucengdes.2014.03.050 https://doi.org/10.1016/j.nucengdes.2014.03.050 https://doi.org/10.1016/j.nucengdes.2014.03.050 https://doi.org/10.1016/j.nucengdes.2014.03.050 https://doi.org/10.1049/rpg2.12541 https://doi.org/10.1049/rpg2.12541 https://doi.org/10.1049/rpg2.12541 https://doi.org/10.1049/rpg2.12541 https://doi.org/10.1109/naps52732.2021.9654717 https://doi.org/10.1109/naps52732.2021.9654717 https://doi.org/10.1109/naps52732.2021.9654717 https://doi.org/10.1109/naps52732.2021.9654717 https://doi.org/10.3390/en11020432 https://doi.org/10.3390/en11020432 https://doi.org/10.3390/en11020432 https://doi.org/10.1109/powerafrica.2019.8928865 https://doi.org/10.1109/powerafrica.2019.8928865 https://doi.org/10.1109/powerafrica.2019.8928865 https://doi.org/10.1109/powerafrica.2019.8928865 https://doi.org/10.3390/su11113168 https://doi.org/10.3390/su11113168 https://doi.org/10.3390/su11113168 https://doi.org/10.3390/su11113168 http://hdl.handle.net/11540/6716 http://hdl.handle.net/11540/6716 https://doi.org/10.1109/repe48501.2019.9025162 https://doi.org/10.1109/repe48501.2019.9025162 https://doi.org/10.1109/repe48501.2019.9025162 https://doi.org/10.1109/repe48501.2019.9025162 https://doi.org/10.1109/repe48501.2019.9025162 https://doi.org/10.1016/j.apenergy.2021.117542 https://doi.org/10.1016/j.apenergy.2021.117542 https://doi.org/10.1016/j.apenergy.2021.117542 introduction ii. methodology a. exploratory on microgrid system b. analysis of potential impact of component degradation & performance deterioration c. constraints and limitations iii. component degradation and system deterioration a. component degradation b. system deterioration c. other performance reduction factor iv. the impact on performance reduction of the microgrid system a. expected energy not achieved b. loss of power supply c. shorter life expectancy d. early microgrid failure e. open issues on early termination of microgrid system v. conclusion acknowledgments declarations author contribution funding statement competing interest additional information references effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.25-32 effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia ghalya pikra *, andri joko purwanto, adi santoso research centre for electrical power & mechatronics, indonesian institute of sciences kampus lipi, jln. sangkuriang, gd. 20, bandung, 40135 received 24 may 2012; received in revised form 04 june 2013; accepted 06 june 2013 published online 30 july 2013 abstract this paper presents effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power in yogyakarta, indonesia. solar thermal power is a plant that uses solar energy as heat source. indonesia has high humidity level, so that parabolic trough is the most suitable type of solar thermal power technology to be developed, where the design is made with small focal distance. organic rankine cycle (orc) is a rankine cycle that use organic fluid as working fluid to utilize low temperature heat sources. rorc is used to increase orc performance. the analysis was done by comparing orc system with and without regenerator addition. refrigerant that be used in the analysis is r123. preliminary data was taken from the solar collector system that has been installed in yogyakarta. the analysis shows that with 36 m total parabolic length, the resulting solar collector capacity is 63 kw, heat input/evaporator capacity is determined 26.78 kw and turbine power is 3.11 kw for orc, and 3.38 kw for rorc. orc thermal efficiency is 11.28% and rorc is 12.26%. overall electricity efficiency is 4.93% for orc, and 5.36% for rorc. with 40°c condensing temperature and evaporation at 10 bar saturated condition, efficiency of rorc is higher than orc. greater evaporation temperature at the same pressure (10 bar) provide greater turbine power and efficiency. keywords: solar thermal power, parabolic trough, regenerative organic rankine cycle, regenerator, r123. i. introduction nowadays renewable energy development is very important to overcome energy problem in the world. solar energy is a potential renewable energy source for solving energy problems. indonesia is a tropical country which has good solar radiation (4.8 kwh/m2/day) [1], so it is good for developing solar energy. concentrating solar energy is a very promising technology among solar energy conversion systems, and parabolic troughs are the most mature application solar thermal technologies in the market [2]. parabolic trough technology was chosen to be developed by lipi, because indonesia has high humidity, so it was designed with small focal distance [3, 4]. lipi is developing parabolic trough by using organic rankine cycle (orc) for electricity generation system, because it has low temperature heat sources. orc is a rankine cycle that use organic fluid as working fluid to utilize low temperature heat sources. orc is one of the best used and promising ways in low heat source applications than many well-proven technologies [5]. orc system ensures high efficiencies for small-scale applications and/or low temperature heat sources, compared with other alternative technologies [610]. furthermore, orc shows high flexibility, safety and low costs and maintenance requirements [11-14]. quoilin et al. presented the design of a solar organic rankine cycle installed in lesotho, where the system consisted of parabolic trough collectors, a thermal storage tank, and a small-scale orc system using scroll expanders. the results show that the overall electricity efficiency of the system could reach 7% and 8% [15]. the selection of the working fluid in the orc system is very important to produce optimal performance. dry and isentropic fluids are the most preferred working fluid for the orc [16]. the research in this paper is using r123 as organic fluid. r123 was able to improve the orc performance significantly for low grade heat * corresponding author. tel: +62-8782-1141-108 e-mail: ghalya30@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.25-32 g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 26 source application [17]. overall efficiency for orc cycle using r123 as working fluid and coupled to cpc collectors was about 7.9% for a solar intensity of 800 w/m2 and an evaporating temperature of 147°c [5]. r123 was a better working fluid than r12 and r134a for a waste heat recovery on the work output and efficiency of thermodynamic first law and second law system [18, 19]. performance of orc can be improved by regenerative organic rankine cycle (rorc). regenerator is used as an addition component for rorc. regenerator addition can improve system efficiency [20, 21]. regenerator is also used when the fluid is still strongly overheated after the expansion in the turbine. regenerator is located at the exhaust of turbine on the low pressure side, and between the pump and evaporator on the high pressure side. this reduces the heat duty of the condenser and at the same time raises the enthalpy of the working fluid leaving the pump. this condition can improve thermodynamic efficiency [22]. compared with orc, rorc with a lower irreversibility produces higher efficiency while also reducing the amount of waste heat required to produce the same power [23]. xu rong ji et al. [24] proposed rorc that used a vapor injector as regenerator, where the results showed that there existed the inlet vapor pressure regions for the injector that allowed the new cycle performed better than the basic orc. pei gang et al. [25] analyze that the system electricity efficiency with rorc for irradiance 750 w/m2 is about 8.6% and is relatively higher than orc by 4.9%. this paper presents effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power by using r123 as organic fluid. analysis was done by using data from solar collector that has been built in yogyakarta by varying evaporating temperature. ii. system description and working principle solar collector unit in the form of parabolic trough serves to capture solar heat energy. the heat is stored in thermal storage tank. through heat transfer fluid circulation with 200°c maximum temperature, the heat energy is used to vaporize organic fluid in the evaporator at orc system as organic turbine driver. rotary of turbine shaft is then connected to generator to produce electricity. this system can be operated in hybrid with other heat sources such as biomass. in this research, the heat transfer fluid is palm oil and organic fluid is r123. basic orc consists of evaporator, turbine, condenser and feeder pump. evaporator is a component for heating working fluid from liquid to vapor to be expanded in turbine. turbine is a component for expanding vapor to produce electricity by generator. condenser is a component for condensing vapor from the turbine, and feeder pump is a component for pumping fluid from low pressure to high pressure. regenerative organic rankine cycle (rorc) is made to utilize the heat of the working fluid at the superheated condition after undergoing expansion in the turbine. regenerator is added to make use of a working fluid that is in the form of vapor from turbines, so the heat can be used to increase working fluid enthalpy leaving the pump. the addition of regenerator would increase the efficiency of the system as waste heat in the regenerator after expanded utilized to heat the fluid when it will go into the evaporator, so that the waste heat will be reduced. schematic of rorc is showed in figure 1. parabolic trough has been built in upt bpptk yogyakarta. the design was made with 6 modules where specification of each module is 3.5 m of aperture width and 6 m of parabolic length. this means for 6 modules, total parabolic g so la r c ol le ct or so la r c ol le ct or storage tank evaporator turbine generatorhybrid with biomass oil pump oil pump feeder pump c on de ns er solar field storage system electricity generation system cooling tower water pump regenerator 1 2 3 4 5 6 7 8 9 10 11 12 figure 1. schematic of regenerative organic rankine cycle (rorc) g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 27 length is 36 m. ptsc design was made as preliminary data for determining orc and rorc as electricity generation system. figure 2 shows parabolic trough solar collector that has been built in upt bpptk yogyakarta. working fluid which is used in the system is r123. r123 is a low pressure refrigerant, so it is good for low working pressure system. table 1 [26] shows physical and thermodynamic properties of r123. iii. basic calculation calculation of solar thermal power using the rorc is divided into two parts. first part is in solar field and storage system area, and the second is at electricity generation system (rorc). flow diagram for determining performance of the solar thermal power optimization using rorc is showed in figure 3. preliminary data of solar collector that has been built in yogyakarta is used for determining performance of solar collector using rorc. aperture width and parabolic length as basic data are used to calculate aperture area using equation figure 2. parabolic trough solar collector (ptsc) table 1. physical and thermodynamic properties of r123 characteristics properties chemical name 2,2-dichloro-1,1,1trifluoroethane chemical formula chcl2cf3 slope of saturation vapor line isentropic molecular weight 152.9 g/mol boiling temperature 27.8°c critical temperature and pressure 183.7°c, 36.68 bar odpa 0.02 gwpb 77 hazard ratingc: health flammability reactivity 2 1 0 a relative to r11; b relative to co2 (100 y time horizon); c hazard rating: 0 = no hazard, 1 = slightly hazardous, 2 = moderately hazardous, 3 = severely hazardous, 4 = extremely hazardous start aperture width (la): 3.5 m parabolic length (p): 36 m assumption: solar intensity average (i): 500 w/m2 aperture area (a) solar collector capacity (qsc) solar collector efficiency (ηsc): 50% thermal storage efficiency (ηsc): 85% thermal storage capacity (qts) evaporator capacity (qin) t11: 200°c t12: 190°c return oil pump (rop): mass flow rate (mrop) volumetric flow rate (qrop) finish t9: 150°c t10: 125°c hot oil pump (hop): mass flow rate (mhop) volumetric flow rate (qhop) finish state condition: condensing temperature (t3): 40°c evaporating temperature (t1): 111.2°c refrigerant mass flow rate (mref) regenerator capacity (qreg) condenser capacity (qout) pump power (wp) turbine power (wt) thermal efficiency (ηth) electricity efficiency (ηel) finish figure 3. flow diagram design optimization of solar thermal power using rorc g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 28 (1). by an assumption average solar intensity, solar collector capacity is determined by equation (2). 𝐴𝐴 = 𝑝𝑝 × 𝑙𝑙𝑎𝑎 (1) 𝑄𝑄𝑆𝑆𝑆𝑆 = 𝐼𝐼 × 𝐴𝐴 (2) where a : aperture area (m2) p : parabolic length (m) la : aperture width (m) qsc : solar collector capacity (kw) i : solar intensity (w/m2) by solar collector efficiency of 50% [27], thermal storage capacity is determined by equation (3). heat input/evaporator capacity is determined to be preliminary data for rorc calculation. with an assumption of 85% thermal storage capacity, heat input/evaporator capacity is showed by equation (4). 𝑄𝑄𝑇𝑇𝑆𝑆 = 𝑄𝑄𝑆𝑆𝑆𝑆 × 𝜂𝜂𝑆𝑆𝑆𝑆 (3) 𝑄𝑄𝑖𝑖𝑖𝑖 = 𝑄𝑄𝑇𝑇𝑆𝑆 × 𝜂𝜂𝑇𝑇𝑆𝑆 (4) where qts : thermal storage capacity (kw) ηsc : solar collector efficiency qin : heat input/evaporator capacity (kw) ηts : thermal storage efficiency mass flow rate of return oil pump and hot oil pump are determined to calculate volumetric flow rate. it is used to select pump to be used for the system. mass flow rate and volumetric flow rate calculation are showed by equation (5) and (6) [28]. �̇�𝑚𝑂𝑂𝑂𝑂 = 𝑄𝑄𝑇𝑇𝑆𝑆 𝑆𝑆𝑝𝑝𝑂𝑂𝑂𝑂 ×(𝑇𝑇𝑖𝑖𝑖𝑖 −𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 ) (5) 𝑞𝑞𝑂𝑂𝑂𝑂 = �̇�𝑚𝑂𝑂𝑂𝑂 𝜌𝜌𝑂𝑂𝑂𝑂 (6) where �̇�𝑚𝑂𝑂𝑂𝑂 : mass flow rate of return/hot oil pump (kg/s) cpop : specific heat fluid at average temperature (kj/kg °c) tin : inlet temperature (°c) tout : outlet temperature (°c) qop : volumetric flow rate of return/hot oil pump (m3/s) 𝜌𝜌𝑂𝑂𝑂𝑂 : density of palm oil at average temperature (kg/m3) iv. thermodynamic analysis regenerative organic rankine cycle (rorc) is analyzed to increase solar thermal power performance that has been built in yogyakarta. heat input/evaporator capacity is a preliminary data to determine the performance. with regenerator addition, rorc is showed by figure 4. each of rorc components can be determined. red lines show high pressure and blue lines show low pressure. thermodynamic analysis is used as standard calculation to determine performance of rorc. t-s diagram is made to simplify the calculation. t-s diagram of r123 is showed in figure 5. ideal (reversible) cycle at figure 5 is showed in green colors, real (irreversible) cycle is showed in red colors, and regenerator addition at the cycle is showed in the other color with varying evaporation temperatures. the assumptions for analyzing rorc are steady state condition, working pressure through condenser and evaporator are constant, inlet pump fluid is saturated liquid, inlet condenser fluid is saturated vapor, turbine and pump work adiabatically, and kinetic and potential energy are negligible. thermodynamic analysis is started from feeder pump and turbine efficiency. equation (7) and (8) are used to determine enthalpy at outlet turbine regenerator condenser feeder pump evaporator oil in oil out cooling water in cooling water out g wt qoutwp qin qreg 1 2 3 4 5 6 figure 4. regenerative organic rankine cycle (rorc) figure 5. t-s diagram of r123 0 50 100 150 200 1 1.5 2 t em pe ra tu re (c ) entropy (kj/kg c) ideal real reg110 reg120 reg130 reg140 g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 29 pump/inlet regenerator (h2) and enthalpy at outlet turbine/inlet regenerator (h5). 𝜂𝜂𝑝𝑝 = ℎ2𝑠𝑠−ℎ1 ℎ2−ℎ1 (7) 𝜂𝜂𝑇𝑇 = ℎ4−ℎ5 ℎ4−ℎ5𝑠𝑠 (8) where ηp : pump isentropic efficiency ηt : turbine isentropic efficiency h1 : enthalpy at inlet pump/outlet condenser (kj/kg) h2 : enthalpy at outlet pump/inlet regenerator (kj/kg) h2s : enthalpy isentropic at outlet pump/inlet regenerator (kj/kg) h4 : enthalpy at inlet turbine/outlet evaporator (kj/kg) h5 : enthalpy at outlet turbine/inlet regenerator (kj/kg) h5s : enthalpy isentropic at outlet turbine/inlet regenerator (kj/kg). next step is calculating enthalpy at output regenerator/input evaporator (h3) and refrigerant mass flow rate (�̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ). balance energy in regenerator at equation (10) is used to calculate h3, and balance energy in evaporator at equation (11) is used to calculate �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 . after calculating h3 and �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 , then regenerator capacity (qreg) at equation (9) can be determined. 𝑄𝑄𝑟𝑟𝑟𝑟𝑟𝑟 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ5 − �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ6 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ3 − �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ2 (9) ℎ3 = ℎ5 + ℎ2 − ℎ6 (10) �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ3 + 𝑄𝑄𝑖𝑖𝑖𝑖 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ4 (11) where qreg : regenerator capacity (kw) h3 : enthalpy at output regenerator/input evaporator (kj/kg) h6 : enthalpy at outlet regenerator/inlet condenser (kj/kg) �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 : mass flow rate of refrigerant (kg/s) qin : heat input/evaporator capacity (kw). balance energy of condenser, feeder pump and turbine are showed by equation (12), (13) and (14). �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ6 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ1 + 𝑄𝑄𝑜𝑜𝑜𝑜𝑜𝑜 (12) �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ1 + 𝑊𝑊𝑂𝑂 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ2 (13) �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ4 = �̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ℎ5 + 𝑊𝑊𝑇𝑇 (14) where qout : heat output/condenser capacity (kw) wp : pump power (kw) wt : turbine power (kw) after calculating capacity and power of each component, thermal efficiency of rorc and electricity efficiency can be determined. thermal efficiency and electricity efficiency are showed by equation (15) and (16). 𝜂𝜂𝑜𝑜ℎ = 𝑊𝑊𝑇𝑇−𝑊𝑊𝑝𝑝 𝑄𝑄𝑖𝑖𝑖𝑖 (15) 𝜂𝜂𝑟𝑟𝑙𝑙 = 𝑊𝑊𝑇𝑇 𝑄𝑄𝑆𝑆𝑆𝑆 (16) where 𝜂𝜂𝑜𝑜ℎ : thermal efficiency of rorc 𝜂𝜂𝑟𝑟𝑙𝑙 : electricity efficiency of rorc v. results and discussion rorc is analyzed to determine its effect to solar thermal power that has been built in yogyakarta. result of rorc for basic calculation is showed by table 2. result for basic calculation shows that for 36 m parabolic length and average solar intensity 500 w/m2, solar collector capacity is 63 kw and the heat input (evaporator capacity) is 26.78 kw. the heat input is then used as a data to determine performance of rorc as electricity generation system. another data for rorc to determine properties of each point are low pressures at 1.545 bar (40°c) and high pressures at 10 bar (111.2°c). result for rorc is showed by table 3. the result shows that turbine power increase from 3.11 kw to 3.38 kw by using rorc. thermal efficiency of the system also increases from 11.28% to 12.26%, and the overall electricity efficiency of the system increases from 4.93% to 5.36%. this means that regenerator addition can improve solar thermal power performance. if the experiments are arranged to higher evaporating temperature (until 140oc), then result of the design with the same high pressure are showed in figure 6 to figure 12. figure 6 shows that regenerator capacity rises at the increasing evaporating temperature. this occurs because the superheat conditions cause more waste heat in the condenser, that waste heat is utilized in the regenerator to heat the working table 2. design result for basic calculation design result value aperture area (a) 126 m2 solar collector capacity (qsc) 63 kw thermal storage capacity (qts) 31.5 kw evaporator capacity/heat input (qin) 26.78 kw return oil pump mass flowrate (�̇�𝑚𝑅𝑅𝑂𝑂𝑂𝑂) 1.304 kg/s return oil pump volumetric flowrate (qrop) 0.002 m 3/s hot oil pump mass flowrate (�̇�𝑚𝐻𝐻𝑂𝑂𝑂𝑂) 1.412 kg/s hot oil pump volumetric flowrate (qhop) 0.002 m 3/s g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 30 fluid, so it can improve thermal efficiency of the system. figure 7 shows the rising of enthalpy entering evaporator at the increasing evaporating temperature in the rorc system. this occurs because at the higher evaporating temperature, there is more waste heat that can be used, thereby it can increase the enthalpy entering evaporator. on the other side, the enthalpy value of ideal and real orc condition are both lower than the rorc system, because under these conditions there are no regenerator, so there are no heat to be utilized. figure 8 shows that the refrigerant mass flow rate in the rorc larger than the ideal and real orc conditions. this is due to the increase in enthalpy entering evaporator, so that the difference in enthalpy at the evaporator inlet and outlet is smaller and cause the value of refrigerant mass flow rate increases. the refrigerant mass flow rate of ideal and real orc condition are smaller than the rorc system, because there is no waste heat utilization in the system. heat output at rorc has a lower value with the increase of evaporation temperature (figure 9). this occurs because the heat rejection in the condenser is utilized in the regenerator to support the increasing of enthalpy (figure 7) when the working fluid is pumped to the evaporator. therefore, the waste heat/heat rejection (which is cooled in the condenser) become smaller due to the heat recovery by the regenerator when vapor exit the turbine. heat output at ideal orc conditions is the smallest but its value is tend to increase, because greater evaporation temperature result greater waste heat. however, because the system is conditioned ideal orc, the generated waste heat is smaller than real orc condition. in real orc condition, the value of heat output is the highest because the system is conditioned on the real orc condition which there is no waste heat utilization (without regenerators). figure 10 shows that the turbine power on rorc system is rising in the greater evaporation temperature. this occurs due to the regenerator addition increases refrigerant mass flow rate (figure 8), thus it increases the turbine power. table 3. design result for electricity generation system design result ideal orc real orc rorc refrigerant mass flowrate (�̇�𝑚𝑟𝑟𝑟𝑟𝑟𝑟 ) 0.1310 kg/s 0.1312 kg/s 0.1425 kg/s refrigerant volumetric flowrate (qref) 331.092 lph 331.362 lph 359.926 lph turbine power (wt) 4.14 kw 3.11 kw 3.38 kw condenser capacity/heat output (qout) 22.69 kw 23.75 kw 23.49 kw regenerator capacity (qreg) 2.31 kw thermal efficiency (ηth) 15.22% 11.28% 12.26% overall electricity efficiency of the system (ηel) 6.57% 4.93% 5.36% figure 8. refrigerant mass flowrate at varying evaporating temperature figure 9. heat output at varying evaporating temperature 0.10 0.12 0.14 0.16 110 120 130 140 m _r ef ( kg /s ) tevap (oc) ideal orc real orc rorc 22.5 23.0 23.5 24.0 110 120 130 140 q ou t (k w ) tevap (oc) ideal orc real orc rorc figure 6. regenerator capacity at varying evaporating temperature figure 7. enthalpy entering evaporator at varying evaporating temperature 0 2 4 6 110 120 130 140 q re g (k w ) tevap (oc) 240 260 280 300 110 120 130 140 e nt ha lp y (k j/ kg ) tevap (°c) ideal orc real orc rorc g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 31 turbine powers in the ideal and real orc condition tend to be smaller with the increasing of evaporation temperature. this happens because the superheat condition causes smaller turbine power and there is no waste heat recovery at the system. figure 11 shows that the rorc increases thermal efficiency by increasing evaporation temperature. this occurs due to the regenerator addition improves thermal efficiency of the system. greater waste heat that can be used result greater thermal efficiency. therefore, figure 11 shows that greater evaporation temperature (superheated conditions) will increase thermal efficiency. thermal efficiency of ideal and real orc system are smaller by increasing evaporation temperature. this occurs because the superheated conditions will reduce performance of the system. figure 12 shows the electricity efficiency of solar thermal power using rorc increases with the increasing of evaporation temperature. this occurs because the turbine power is increased, so that the generated electricity is greater. conversely, ideal and real orc generate smaller electricity with the increasing of evaporation temperature. this happens because smaller turbine power causes smaller electricity generation. vi. conclusion effect of regenerative organic rankine cycle (rorc) on the performance of solar thermal power lead to the conclusion that with 63 kw solar collector capacities, the turbine power that be generated at the ideal orc system is 4.14 kw, 3.11 kw for real orc and 3.38 kw with the addition of regenerator (rorc). thermal efficiency of the ideal orc is 15.22%, 11.28% for real orc and 12.26% for rorc. the results show that the rorc improve and enhance the performance of the system compare to the real orc. the addition of regenerator is used to utilize waste heat from the turbine to the condenser, so the heat output is reduced/smaller and enthalpy entering evaporator become higher. these conditions will increase the turbine power, thermal and electricity efficiency of the system. references [1] a. susandi, "indonesia's geothermal: development and cdm potential," in international geosciences conference and exhibition, jakarta, indonesia, 2006. [2] a. giostri, et al., "comparison of different solar plants based on parabolic trough technology," solar energy, vol. 86, pp. 1208-1221, 2012. [3] g. pikra, et al., "parabolic trough solar collector initial trials," journal of mechatronics, electrical power, and vehicular technology, vol. 02, pp. 5764, 2011. [4] g. pikra, et al., "development of small scale concentrated solar power plant using organic rankine cycle for isolated region in indonesia," energy procedia, vol. 32, pp. 122-128, 2013. [5] l. jing, et al., "optimization of low temperature solar thermal electric generation with organic rankine cycle in different areas," applied energy, vol. 87, pp. 3355-3365, 2010. [6] s. quoilin, et al., "experimental study and modeling of an organic rankine cycle using scroll expander," applied energy, vol. 87, pp. 1260-1268, 2010. [7] w. li, et al., "effects of evaporating temperature and internal heat exchanger figure 10. turbine power at varying evaporating temperature figure 11. thermal efficiency at varying evaporating temperature figure 12. electricity efficiency at varying evaporating temperature 3.0 3.5 4.0 4.5 110 120 130 140 w t (k w ) tevap (oc) ideal orc real orc rorc 10 12 14 16 110 120 130 140 ηt h (% ) tevap (oc) ideal orc real orc rorc 4 5 6 7 110 120 130 140 ηe l ( % ) tevap (oc) ideal orc real orc rorc g. pikra, et al. / mechatronics, electrical power, and vehicular technology 04 (2013) 25-32 32 on organic rankine cycle," applied thermal engineering, vol. 31, pp. 40144023, 2011. [8] y. dai, et al., "parametric optimization and comparative study of organic rankine cycle (orc) for low grade waste heat recovery," energy conversion and management, vol. 50, pp. 576-582, 2009. [9] b. saleh, et al., "working fluids for lowtemperature organic rankine cycles," energy, vol. 32, pp. 1210-1221, 2007. [10] m. bianchi and a. de pascale, "bottoming cycles for electric energy generation: parametric investigation of available and innovative solutions for the exploitation of low and medium temperature heat sources," applied energy, vol. 88, pp. 1500-1509, 2011. [11] j. p. roy, et al., "performance analysis of an organic rankine cycle with superheating under different heat source temperature conditions," applied energy, vol. 88, pp. 2995-3004, 2011. [12] a. i. papadopoulos, et al., "on the systematic design and selection of optimal working fluids for organic rankine cycles," applied thermal engineering, vol. 30, pp. 760-769, 2010. [13] d. wei, et al., "performance analysis and optimization of organic rankine cycle (orc) for waste heat recovery," energy conversion and management, vol. 48, pp. 1113-1119, 2007. [14] s. quoilin and v. lemort, "technological and economical survey of organic rankine cycle systems," in 5th european conference economics and management of energy in industry, algarve, portugal, 2009, pp. 14-17. [15] s. quoilin, et al., "performance and design optimization of a low-cost solar organic rankine cycle for remote power generation," solar energy, vol. 85, pp. 955-966, 2011. [16] n. b. desai and s. bandyopadhyay, "process integration of organic rankine cycle," energy, vol. 34, pp. 1674-1686, 2009. [17] t. yamamoto, et al., "design and testing of the organic rankine cycle," energy, vol. 26, pp. 239-251, 2001. [18] j. p. roy, et al., "parametric optimization and performance analysis of a waste heat recovery system using organic rankine cycle," energy, vol. 35, pp. 5049-5062, 2010. [19] j. p. roy and a. misra, "parametric optimization and performance analysis of a regenerative organic rankine cycle using r-123 for waste heat recovery," energy, vol. 39, pp. 227-235, 2012. [20] s. quoilin, "experimental study and modeling of a low temperature rankine cycle for small scale cogeneration," electro mechanical engineer (energetic engineering) partial fulfillment, faculty of applied sciences aerospace and mechanical engineering department thermodynamics laboratory, university of liege, 2007. [21] b. liu, et al., "investigation of a two stage rankine cycle for electric power plants," applied energy, vol. 100, pp. 285-294, 2012. [22] a. s. panesar, "a study of organic rankine cycle systems with the expansion process performed by twin screw machines," master of philosophy doctoral, school of engineering and mathematical sciences, city university london, london, 2012. [23] p. j. mago, et al., "an examination of regenerative organic rankine cycles using dry fluids," applied thermal engineering, vol. 28, pp. 998-1007, 2008. [24] r.-j. xu and y.-l. he, "a vapor injectorbased novel regenerative organic rankine cycle," applied thermal engineering, vol. 31, pp. 1238-1243, 2011. [25] g. pei, et al., "analysis of low temperature solar thermal electric generation using regenerative organic rankine cycle," applied thermal engineering, vol. 30, pp. 998-1004, 2010. [26] b. f. tchanche, et al., "fluid selection for a low-temperature solar organic rankine cycle," applied thermal engineering, vol. 29, pp. 2468-2476, 2009. [27] a. maccari, "innovative heat transfer concepts in concentrating solar fields," enea solar thermodynamic energy, brussels, june 27 2006. [28] m. j. moran and h. n. shapiro, fundamentals of engineering thermodynamics, 6th ed. usa: john wiley & sons, inc, 2008. mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.24-35 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: l.i. utami et al., “load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 24-35, july 2022. load optimization on the performance of combined cycle power plant block 4 pt indonesia power priok pomu louise indah utami a, *, ika yuliyani a, yanti suprianti a, purwinda iriani a, b a energy conversion engineering department, bandung state polytechnic gegerkalong hilir road, west bandung, 40559, indonesia b chemistry department, university of warwick coventry cv4 7al, united kingdom received 12 november 2021; revised 29 november 2021; accepted 8 december 2021; published online 29 july 2022 abstract combined cycle power plant (ccpp) is a closed-cycle power plant, where the heat from the gas turbine’s (gt) exhaust gas will be streamed to the heat recovery steam generator (hrsg) to be utilized by steam turbine (st). ccpp block 4 (jawa-2) pt indonesia power priok pomu has an installed capacity of 880 mw, consists of 2 gt units (301.5 mw each) and 1 st unit (307.5 mw). the performance of a power plant depends on its load, as the efficiency of the turbine generator is low when operated at low loads. the data as of july 2019 showed that 2.2.1 (2 gt, 2 hrsg, 1 st) configuration has been used in three conditions where the cc net load was around 30 45 %, which in fact could be compensated by the 1.1.1 (1 gt, 1 hrsg, 1 st) configuration. this resulted in a decrease of the cc net efficiency up to 21.34 %. the optimization that can be done is to change the load configuration from 2.2.1 to 1.1.1 at 0 50 % of cc net load through simulations, by including the influence of the gt and hrsg start-up processes. the result of this optimization is that the ccpp performance increases due to higher performance of each turbine generator. thus, the optimization results during july 2019 provided energy saving of 1,146.09 mmbtu or equivalent to cost saving of idr 152,249,551.76. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: combined cycle; gas turbine; steam turbine; load optimization; power plant performance. i. introduction pt indonesia power priok power generation and o&m unit (pomu) manages four ccpp blocks with a total installed capacity of 2,800 mw. the ccpp block 4 (jawa-2) is the newest generating unit in the priok pomu, which has been operating (open cycle) since june 2018 and completed the integration with its st unit (combined cycle) in may 2019. ccpp block 4 is connected to the jawa-bali power system, with an installed capacity of 880 mw and consists of 2 gt units and 1 st unit. the power plant performance parameters include efficiency and heat rate, which are closely related to its load [1][2][3]. when the turbine generator load is well below its design capacity, its efficiency will also drop significantly. therefore, it is important to keep the turbine generator loaded according to its capacity; especially at low generation loads. in the manual book, the 2.2.1 configuration is used when the cc net load is more than 45 %. meanwhile, several conditions at the site (july 2019) showed that the 2.2.1 (2 gt, 2 hrsg, 1 st) configuration has been used in the cc net load of around 30 45 %, resulted up to 21.34 % reduction in the efficiency of the generating unit. the lower efficiency is certainly detrimental because more fuel is needed for the same generated power [4][5]. because the cc load varies over time, the effort that can be made is to set each turbine generator load to remain high [6][7][8]. the setting is done by distributing the turbine generator load at the right part load [9][10], so that the cc performance remains high wherever the load is. this journal will discuss optimization in the form of changing the loading configuration from 2.2.1 (2 on 1) to 1.1.1 (1 on 1) at 0 50 % of cc net load by including the influence of the gt and hrsg start-up processes, and show the actual part load efficiency which actually occurs in real conditions. * corresponding author. phone: +62-222011095 e-mail address: louiseindahutami@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.24-35 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.24-35 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.24-35&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 25 ii. materials and methods a. combined cycle power plant (ccpp) simple cycle gas turbine and combined cycle gas turbine power plants have traditionally served as peaking units because they can be started within minutes and ramped up and down quickly to meet spikes in demand or sudden changes in electric system loads. combined cycle power plants can respond to load changes faster than conventional steam power plants [11]. the term of combined cycle (cc) refers to the combining of multiple thermodynamic cycles to generate power [11], as shown in figure 1. the first cycle is the brayton cycle which consists of a compressor, combustion chamber, and the gas turbine (gt) itself. the second cycle is the rankine cycle which consists of pumps, heat recovery steam generator (hrsg), the steam turbine (st), and a condenser. brayton cycle occurs at high temperature and the rankine cycle occurs with lower temperature. while conventional thermal plants discard waste gases to the environment at high temperature, combined cycle plants take advantage of these gases at high temperatures. the exhaust heat from the gas turbine cycle is used to generate steam at high pressure and high temperature that will be expanded in a steam turbine to generate additional power [13]. in this cycle, energy is recovered from the exhaust gases by transferring it to the steam in a heat exchanger that serves as the boiler. in general, more than one gas turbine is needed to supply sufficient heat to the steam. also, the steam cycle may involve regeneration as well as reheating. energy for the reheating process can be supplied by burning some additional fuel in the oxygen-rich exhaust gases [12]. in comparison with steam power plants which offer a thermal efficiency of about 40 %, combined cycle power plants deliver a thermal efficiency of about 60 % (based on lower heating values) [14]. b. ccpp working principle the ccpp layout is shown in figure 2. the gas turbine of ccpp is maneuverable and can change output power faster than steam turbine. steam turbine in ccpp operates under variable pressure. so, steam turbine power varies with long response time depending on gas turbine power [15]. after passing the compressor, air is mixed with fuel in combustion chamber. the mixture burns and hot gases are expanded in gas turbine then rotate it. after the gas turbine, hot gas goes to hrsg, where it heats water. water becomes a steam which rotates the steam turbine [15]. c. ccpp performance 1) gas turbine (gt) heat rate and efficiency 𝐺𝐺𝐺𝐺𝐺 = 𝐹𝑓𝑓𝑓𝑓 𝑥 𝐿𝐿𝐿𝑓𝑓𝑓𝑓 𝑃𝐺𝐺𝐺𝐺 𝑥 1000 𝑥 4.184 (1) figure 1. flow diagram and t-s diagram of ccpp [12] figure 2. ccpp layout [15] l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 26 𝜂𝐺𝐺𝐺 = 860 𝐺𝐺𝐺𝐿𝐺 𝑥 100% (2) 𝐺 = 1~2, 𝐺 = 1 → 𝐺𝐺1, 𝐺 = 2 → 𝐺𝐺2 (3) where 𝐺𝐺𝐺𝐺𝐺 is gt heat rate, 𝐹𝑓𝑓𝑓𝑓 is fuel flowrate, 𝐿𝐺𝐿𝑓𝑓𝑓𝑓 is fuel lhv, 𝑃𝐺𝐺𝐺𝐺 is active power gtg, and 𝜂𝐺𝐺𝐺 is gt efficiency. 2) steam turbine (st) heat rate and efficiency 𝐺𝐿𝐿𝐿𝐿 = 1,4797𝑥10−8 𝐺𝐿𝑃 2 + 1,0555𝑥10−2 𝐺𝐿𝑃 + 8,1584𝑥103 (4) 𝐺𝐶𝐺𝐿 = 𝐺𝐿𝑃 − 𝐺𝐿𝐿𝐿𝐿 (5) 𝐺𝐿𝐺𝐿 = 𝐺𝐶𝐺𝐿 + 𝐺𝐼𝑃 (6) 𝐺𝑆𝐺 = (𝐺𝐿𝑃 𝑥 𝐺𝐿𝑃) + (𝐺𝐿𝐺𝐿 𝑥 𝐺𝐿𝐺𝐿) + (𝐺𝐿𝑃 𝑥 𝐺𝐿𝑃) − (𝐺𝐶𝐺𝐿 𝑥 𝐺𝐶𝐺𝐿) − (𝐺𝐶𝐶 𝑥 𝐺𝐺𝐶) (7) 𝑆𝐺𝐺𝐺 = 𝐿𝑆𝐺 𝑃𝑆𝐺𝐺 𝑥 4.184 (8) 𝜂𝑆𝐺 = 860 𝑆𝐺𝐿𝐺 𝑥 100% (9) where 𝐺𝐿𝐿𝐿𝐿 is turbine leakage flow, 𝐺𝐿𝑃 is hp main steam flow, 𝐺𝐶𝐺𝐿 is cold reheat steam flow, 𝐺𝐿𝐺𝐿 is hot reheat steam flow, 𝐺𝐼𝑃 is ip steam flow, 𝐺𝐿𝑃 is lp steam flow, 𝐺𝐺𝐶 is condenser condensate flow, 𝐺𝐿𝑃 is hp steam enthalpy, 𝐺𝐶𝐺𝐿 is hot reheat steam enthalpy, 𝐺𝐿𝐺𝐿 is hot reheat steam flow, 𝐺𝐿𝑃 is lp steam flow, 𝐺𝐶𝐶 is condensate enthalpy, 𝐺𝑆𝐺 is st heat input, 𝑆𝐺𝐺𝐺 is st heat rate, and 𝜂𝑆𝐺 is st efficiency. 3) net plant heat rate and net efficiency 𝑁𝑃𝐺𝐺 = 𝐹𝑓𝑓𝑓𝑓 𝑥 𝐿𝐿𝐿𝑓𝑓𝑓𝑓 𝑃𝑛𝑓𝑛 𝑥 1000 𝑥 4.184 (10) 𝑃𝑛𝑓𝑛 = 𝑃𝑛𝑓𝑛 𝐺𝐺1 + 𝑃𝑛𝑓𝑛 𝐺𝐺2 + 𝑃𝑛𝑓𝑛 𝑆𝐺 (11) 𝜂𝑁𝐿𝐺 = 860 𝑁𝑃𝐿𝐺 𝑥 100% (12) where 𝑁𝑃𝐺𝐺 is net plant heat rate, 𝐹𝑓𝑓𝑓𝑓 is fuel flowrate, 𝐿𝐺𝐿𝑓𝑓𝑓𝑓 is fuel lhv, 𝑃𝑛𝑓𝑛 is block net active power, and 𝜂𝑁𝐿𝐺 is net plant efficiency. d. ccpp block 4 priok pomu ccpp block 4 (jawa-2) priok pomu is located in north jakarta, with the power plant’s overview shown in figure 3. ccpp block 4 is an asset owned by pt perusahaan listrik negara and operated by pt indonesia power. ccpp block 4 is the newest generating unit in priok pomu, manufactured by mitsubishi hitachi power systems (mhps). this generating unit has an installed capacity of 880 mw and has been operating since may 2019. the ccpp block 4 consists of two gas turbines (gt), two heat recovery steam generators (hrsg), one steam turbine (st), and one condenser as shown in figure 4. table 1 shows the performance of ccpp block 4 according to the manufacturer’s design, with variations in the loading configuration of 1.1.1 (1 gt, figure 3. ccpp block 4 priok pomu figure 4. ccpp block 4 priok pomu scheme l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 27 1 hrsg, 1 st) and 2.2.1 (2 gt, 2 hrsg, 1 st). figure 5 shows the limits for the use of 1.1.1 and 2.2.1 configurations, as well as the maximum limits for ramp-up or ramp-down rates. it is written that the 2.2.1 configuration is used when the generating load is from 410 mw to 880 mw (47 100 %). if the 2.2.1 configuration is used at lower loads, then the performance will be lower as well. 1) gt m701f4 (mhps takasago) 2 x 301.5 mw there are two gts (gt1 and gt2) with an installed capacity of 301.5 mw each. in figure 6, the right side is the air compressor rotor and the left side is the turbine rotor itself. the compressor impeller and turbine blades are in the form of airfoils and are made in stages so that the work generated from the combustion process by the combustor will be maximized. table 2 shows the gas turbine (gt) specifications according to manufacturer’s design; including efficiency and heat rate when the gt is fully loaded (100 %), as well as the allowed ramp rate limit. 2) hrsg (mhps kure) there are 2 hrsg units, namely hrsg1 and hrsg2. figure 7 shows heat recovery steam generator (hrsg) 3d design. it can be seen that the figure 5. loading configuration based on design figure 6. gt m701f4 rotor table 1. ccpp block 4 priok pomu performance based on design load configuration parameter unit 1 on 1 plant output 566 mw plant efficiency 62.0 % lhv 2 on 1 plant output 1,135 mw plant efficiency 62.2 % lhv starting time 45 minutes table 2. gt m701f4 specifications parameter unit frequency 50 hz iso base rating 385 mw efficiency 41.9 % lhv lhv heat rate 8,592 kj/kwh 8,144 btu/kwh exhaust flow 748 kg/s 1,650 lb/s exhaust temperature 630 °c 1,167 °f exhaust emission nox 25 ppm @15 % o2 co 10 ppm @15 % o2 turn down load 45 % ramp rate 38 mw/min starting time 30 minutes figure 7. hrsg structure l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 28 hp tubes are in the front side, the ip tubes are in the middle side, and the lp tubes are at the rear side of the hrsg. this causes the steam temperature at hp tubes to be the highest, while in the lp tubes is the lowest; because the heat energy from the gt exhaust gas has been absorbed by the hp and ip tubes first. figure 8 shows the hrsg heat balance according to manufacturer’s design; containing technical specifications of exhaust gas from gt, feedwater, and steam in hp, ip, crh, hrh, and lp drums. 3) st tc2f-40.5” (mhps nagasaki) 1 x 307.5 mw there is one st with an installed capacity of 307.5 mw. st will reach its full load if both gt1 and gt2 are also operated at full load (2 x 301.5 mw), because the heat utilization that can be generated by st only reaches about 50 % of the heat in the gt exhaust gas. st gets its steam supply from the combination of the hrsg1 and hrsg2. as shown in figure 9, there are three types of blades on the st rotor, each of which operates at different pressures. the hp turbine is on the right side, followed by the ip turbine in the middle side, and the lp turbine is on the left side of the st. meanwhile the generator rotor is installed on the left end, with the shaft coupled with the three turbine rotors so that they all have one shaft. there are also several specifications including steam pressure and temperature in hp, ip, and lp turbines. (a) (b) figure 8. hrsg heat balance design: (a) section 1; (b) section 2 figure 9. st tc2f-40.5” technical specifications l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 29 iii. results and discussions observations were made during july 2019, with data collected by measuring instruments in one minute intervals. a. gt analysis figure 10 and figure 11 shows the relationship between gt efficiency and the gt load itself. it is seen that the efficiency is high at full load, and low when the load is also low. this happens because the fuel required to maintain the turbine’s torque remains the same when the load (electrical power) of the generator is set high or low. therefore, the gt load must be ensured to be high in order to maintain its high performance. b. cc analysis figure 12 contains two variables, namely the ratio of gt load and st load which is a function of cc net load. the sum of the ratios of gt load to st load will be equal to 1. for example, at 30 % of cc net load (264 mw) the ratio of gt load is 0.63 and st (a) (b) figure 10. fuel flowrate vs gt load: (a) 0 40 %; (b) 40.01 100 % figure 11. gt efficiency vs gt load y = 427.37x + 19428 r² = 0.9855 20000.00 22000.00 24000.00 26000.00 28000.00 30000.00 32000.00 34000.00 36000.00 38000.00 40000.00 0.00 10.00 20.00 30.00 40.00 50.00 fu el f lo w ra te (n m 3/ h ) gt load (%) fuel flowrate (0-40%) y = 562.27x + 15145 r² = 0.9965 30000.00 35000.00 40000.00 45000.00 50000.00 55000.00 60000.00 65000.00 70000.00 75000.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 110.00 fu el f lo w ra te (n m 3/ h ) gt load (%) fuel flowrate (40.01-100%) 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 10 20 30 40 50 60 70 80 90 100 g t ef f (% ) gt load (%) gt eff gt eff baseline l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 30 load is 0.37; this means that gt supplies 0.63 x 264 mw and st supplies 0.37 x 264 mw. the first graph is taken at 1.1.1 configuration, while the second graph is taken at 2.2.1 configuration (includes gt and hrsg start-up processes). these equations will be used for load optimization of 1.1.1 and 2.2.1. in figure 13, there is a condition where the cc efficiency decreases drastically at the same load. this condition occurs when one of the gt starts up, which takes about 25 minutes. this means that during this period there is fuel consumption but the gt has not been able to produce electric power. in addition, another consideration is the impact of gt start-up in the load of 2.2.1 on hrsg start-up processes which will be explained in the next paragraph. as shown in figure 14, the load configuration is 1.1.1 (gt2 on, gt1 off). when the load configuration is changed to 2.2.1 (gt1 is turned on, marked by the area in the box), it can be seen that the st load does not increase immediately (there is a time difference of about 45 minutes since gt1 was on, or 70 minutes since gt1 started up). this is the impact of the hrsg1 start-up process, where the 45 minutes (a) (b) figure 12. gt load and st load ratio vs cc net load: (a)1.1.1 configuration; (b) 2.2.1 configuration figure 13. cc efficiency at sample existing condition y = 0.0026x + 0.5478 r² = 0.8885 y = -0.0026x + 0.4522 r² = 0.8885 0.20 0.30 0.40 0.50 0.60 0.70 0.80 25.00 30.00 35.00 40.00 45.00 50.00 55.00g t lo a d t o c c n et l o a d r a ti o a n d s t lo a d t o c c n et l o a d r a ti o cc net load (%) 1.1.1 gt st linear (gt) linear (st) y = 0.0016x + 0.5024 r² = 0.954 y = -0.0016x + 0.4976 r² = 0.954 0.30 0.40 0.50 0.60 0.70 50.00 60.00 70.00 80.00 90.00 100.00 110.00 g t to ta l lo a d t o c c n et l o a d ra ti o a n d s t lo a d t o c c n et l o a d r a ti o cc net load (%) 2.2.1 gt total st linear (gt total) linear (st) 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 ef f (% ) cc net load (%) optimization plan 15 jul existing baseline linear (baseline) l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 31 difference represents the time needed for hrsg1 to produce steam before flowing it to the st. after this time difference, hrsg1 will be able to immediately respond if there is a change in load on gt1. c. load monitoring during the observations in july 2019, there were three conditions that could be optimized as shown in figure 15. in these three conditions, the 2.2.1 figure 14. st response to hrsg start up (a) (b) (c) figure 15. optimization data targets: (a) 15 july; (b) 22 july; (c) 30 july 0.00 20.00 40.00 60.00 80.00 100.00 1 55 10 9 16 3 21 7 27 1 32 5 37 9 43 3 48 7 54 1 59 5 64 9 70 3 75 7 81 1 86 5 91 9 97 3 10 27 10 81 11 35 11 89 12 43 12 97 13 51 14 05 lo a d (% ) time (00:00-23:59) 15 jul 19 gt1 gt2 st cc 0.00 20.00 40.00 60.00 80.00 100.00 1 41 81 12 1 16 1 20 1 24 1 28 1 32 1 36 1 40 1 44 1 48 1 52 1 56 1 60 1 64 1 68 1 72 1 76 1 80 1 84 1 88 1 92 1 96 1 10 01 10 41 10 81 11 21 11 61 12 01 12 41 12 81 13 21 13 61 14 01 lo a d (% ) time (00:00-23:59) 15 jul 19 gt1 gt2 st cc 0.00 20.00 40.00 60.00 80.00 100.00 1 41 81 12 1 16 1 20 1 24 1 28 1 32 1 36 1 40 1 44 1 48 1 52 1 56 1 60 1 64 1 68 1 72 1 76 1 80 1 84 1 88 1 92 1 96 1 10 01 10 41 10 81 11 21 11 61 12 01 12 41 12 81 13 21 13 61 14 01 lo a d (% ) time (00:00-23:59) 22 jul 19 gt1 gt2 st cc 0.00 20.00 40.00 60.00 80.00 100.00 1 40 79 11 8 15 7 19 6 23 5 27 4 31 3 35 2 39 1 43 0 46 9 50 8 54 7 58 6 62 5 66 4 70 3 74 2 78 1 82 0 85 9 89 8 93 7 97 6 10 15 10 54 10 93 11 32 11 71 12 10 12 49 12 88 13 27 13 66 14 05 lo a d (% ) time (00:00-23:59) 30 jul 19 gt1 gt2 st cc l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 32 configuration was used around 30 45 % of cc net load which should be compensated by the 1.1.1 configuration. optimization will be carried out on the three data, starting from gt start-up process and ending when the cc net load starts to decrease. the time span of the load optimization plan for the three data targets is shown in the table 3. d. determination of load configuration from the three load optimization targets, a data sample was taken; namely july 15, at 04:27 – 11:34 for optimization simulation. in the sample data, three analysis were carried out with the variables listed in the table 4. figure 16 shows that the highest efficiency is achieved with option number 2, which is using the 2.2.1 configuration when the gt load has reached 100 %. option number 2 results in better performance compared to option number 3 (according to the manual book). the baseline itself is the design efficiency according to table 1. the load optimization will be carried out when the configuration moves from 1.1.1 to 2.2.1, with the following conditions. 1. there is one gt which will later be referred to as the main gt, and one other gt which will later be referred to as the follower gt. the main gt is a gt which is already on at low load and will become a fully charged gt (100 %). meanwhile, the follower gt is a gt that will be operated only when the main gt has reached full load and a higher cc net load is desired. this means when load settings occur, tuning will only be carried out on the follower gt, while the main gt will remain at full load. meanwhile, the hrsg that is installed on the main gt will be referred to as the main hrsg and the hrsg that is installed on the follower gt will be referred to as the follower hrsg. the main gt and the follower gt can be gt1 and gt2, or vice versa namely gt2 and gt1. also for the main hrsg and the follower hrsg can be hrsg1 and hrsg2, or vice versa namely hrsg2 and hrsg1. 2. in ramp-up conditions, the gt load can only be increased. likewise in ramp-down conditions, the gt load can only be lowered. the ramp rate follows the procedure in the manual book in figure 5, which is a maximum of 44 mw/minute. 3. in low load conditions (0 – 50 % of cc net load), the load configuration used is 1.1.1 until the main gt is fully charged (100 %). 4. in high load conditions (50 – 100% of cc net load), the load configuration used is 2.2.1 by starting up the follower gt. it takes about 25 minutes of the start-up of follower gt, and about 45 minutes (or 70 minutes from the start-up of follower gt) of the follower hrsg start-up process so that the st load can respond to changes in the follower gt load. 5. the ramp-up process when the load configuration shifts from 1.1.1 to 2.2.1 is done by operating the main gt at full load, then proceed with tuning; namely increasing the follower gt load slowly until the desired load is reached. meanwhile, the ramp-down shifting from 2.2.1 to 1.1.1 configuration is carried out while still operating the main gt at full load, then tuning is done by slowly lowering the follower gt load until the desired load is reached. in these two conditions (ramp-up and ramp-down), the main gt is prioritized to operate at full load. e. load optimization as shown in figure 17, the net efficiency of the cc increases after optimization, because the main gt table 3. load optimization plan cc net load when starting 2.2.1 (%) hrsg start-up (mins) optimization start time end time 29.43 42 15/07/2019 04:27:00 15/07/2019 11:34:00 30.57 42 22/07/2019 02:58:00 22/07/2019 11:31:00 45.13 45 30/07/2019 09:53:00 30/07/2019 11:52:00 table 4. optimization plan options no name description 1 existing 2.2.1 configuration when cc net load reaches 29,58 % and above 2 optimization plan 2.2.1 configuration gt load reaches 100% (or about 50 % cc net load) 3 manual book 2.2.1 configuration when cc net load reaches 45 % and above figure 16. optimization plan options 30.00 40.00 50.00 60.00 70.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 ef f (% ) cc net load (%) optimization plan 15 jul existing optimisation manual book baseline linear (baseline) l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 33 is operated at full load. however, the cc net efficiency will decrease when the cc net load reaches about 45 % due to the follower gt start-up process (about 25 minutes). during an interval of 45 minutes after the follower gt is already on (or 70 minutes since the start-up of the follower gt), the st load has not been able to respond to changes in the load on the follower gt because the follower hrsg is still in the start-up process. after the start-up processes of both follower gt and follower hrsg are completed in 71 minutes (calculated from the start-up of follower gt), the load changes on both gt can be immediately responded by st. figure 18 shows the actual part-load efficiency of the ccpp with the lowest and highest load ranges (based on data collected as of july 2019) after the optimization. the graph shows the highest performance that the ccpp can achieve, wherever the load is. a higher cc net efficiency means the power plant consumes less fuel to generate the same power. the decrease in fuel consumption after the optimization can be seen in figure 19. f. energy and cost saving of load optimization table 5 shows the total energy saving obtained from the three optimization time ranges according to the simulation results. this energy saving has mmbtu unit, with a total of 1,146.09 mmbtu during july 2019. table 6 shows the total cost saving obtained by multiplying the energy saving (in mmbtu) by the price of the fuel (in $/mmbtu). this natural gas fuel is supplied by three vendors with different usage ratios and prices. therefore, cost saving will be calculated based on these parameters. table 7 shows the total cost savings of fuel consumption from this load optimization, which is idr 152,249,551.76, or 5.24 % of the cost during the observation data (july 2019). it should be noted that any loading error in a large capacity power plant will result in greater losses when compared to a smaller capacity power plant. (a) (b) (c) figure 17. cc net efficiency after optimization: (a) 15 july; (b) 22 july; (c) 30 july 30.00 40.00 50.00 60.00 70.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 ef f (% ) cc net load (%) cc net eff 15 jul existing optimization baseline linear (baseline) 30.00 40.00 50.00 60.00 70.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 ef f (% ) cc net load (%) cc net eff 22 jul existing optimization baseline linear (baseline) 40.00 45.00 50.00 55.00 60.00 65.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 ef f (% ) cc net load (%) cc net eff 30 jul existing optimization baseline linear (baseline) l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 34 g. load optimization feasibility analysis from a technical point of view namely equipment safety, there are no constraints because all equipments are operated in the design operation range (0 100 %) so there are no overloads and losses outside of the routine o&m can be avoided. in addition, observations of gt start-up and shutdown in july 2019 were well monitored. start-up and shutdown of gt1 and gt2 were done alternately, thus minimizing damage to one gt because it was operated continuously as the main gt. from an economic point of view, there are no constraints because this optimization does not require investment. this happens because the optimization carried out is in the form of a more optimal operation management. all equipment performances are also still high considering its very new age. figure 18. actual cc net efficiency after optimization (a) (b) (c) figure 19. fuel flowrate after optimization: (a) 15 july; (b) 22 july; (c) 30 july 30.00 40.00 50.00 60.00 70.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 cc e ff (% ) cc net load (%) part load vs cc eff 1.1.1 2.2.1 40000.00 60000.00 80000.00 100000.00 120000.00 140000.00 160000.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 fu el f lo w ra te t o ta l (n m 3/ h ) cc net load (%) fuel flowrate total 15 jul existing optimization 40000.00 60000.00 80000.00 100000.00 120000.00 140000.00 160000.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 fu el f lo w ra te t o ta l (n m 3/ h ) cc net load (%) fuel flowrate total 22 jul existing optimization 40000.00 60000.00 80000.00 100000.00 120000.00 140000.00 160000.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 105.00 fu el f lo w ra te t o ta l (n m 3/ h ) cc net load (%) fuel flowrate total 30 jul existing optimization l.i. utami et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 24-35 35 iv. conclusion this journal has discussed the loading of ccpp block 4 (jawa-2) at pt indonesia power priok pomu during july 2019; with the discovery of three conditions with the use of 2.2.1 (2 gt, 2 hrsg, 1 st) configuration in cc net load of about 30 45 %, which in fact could be compensated by 1.1.1 (1 gt, 1 hrsg, 1 st) configuration. these conditions resulted in the cc net load performance was being lower than its baseline. then the loading configuration was optimized, by changing the configuration from 2.2. 1 to 1.1.1 (or by activating only one gt) for the 0 50 % of cc net load through simulations. the result was that the cc net load performance after the optimization increased, with energy saving of 1,146.09 mmbtu or equivalent to cost saving of idr 152,249,551.76. acknowledgment the authors would like to thank pt indonesia power priok pomu, especially our gratitude to mr. suparlan, mr. rahmat santoso, and mr. alief rakhman mukhtar for the internship opportunity at the company and providing all the operational data. declaration author contribution louise indah utami is the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] g. khankari and s. karmakar, “4-e analysis of a kalina cycle system 11 integrated 500mwe combined thermal power plant, "tencon 2017 2017 ieee region 10 conference, pp. 93-98, 2017. [2] mohammad ali motamed and lars o. nord, “assessment of organic rankine cycle part-load performance as gas turbine bottoming cycle with variable area nozzle turbine technology,” mdpi energies journal, vol. 14, 2021. [3] v. s. kuz'michev, a. y. tkachenko, y. a. ostapyuk, i. n. krupenich and e. p. filinov, "features of computer modeling of the working process of small-scale gas turbine engines," 2017 international conference on mechanical, system and control engineering (icmsc), pp. 136-140, 2017. [4] dan-teodor balanescu and vlad-mario homutescu, “performance analysis of a gas turbine combined cycle power plant with waste heat recovery in organic rankine cycle,” procedia manufacturing (the 12th international conference interdiciplinarity in engineering), vol. 32, pp. 520-528, 2019. [5] m. j. b. kabeyi and o. a. olanrewaju, “performance analysis of an open cycle gas turbine power plant in grid electricity generation,” 2020 ieee international conference on industrial engineering and engineering management (ieem), pp. 524529, 2020. [6] yongyi li, guoqiang zhang, ligang wang, and yongping yang, “part-load performance analysis of a combined cycle with intermediate recuperated gas turbine,” energy conversion and management, vol. 205, 2020. [7] dede mavendra, “kalkulasi efisiensi daya mesin pltgu dengan pola operasi 2-2-1 dan 3-3-1 pt indonesia power unit pembangkitan semarang,” usd repository, 2016. [8] xiang wan, niansu hu, pengfei han, shiqi li, “performance monitoring of the gas-steam combined cycle unit in multienergy power grid,” proceedings of the 2015 international conference on sustainable energy and environmental engineering, oct. 2015. [9] michael welch, “improving the flexibility and efficiency of gas turbine-based distributed power plant,” 8th international gas turbine conference, etn global, 2016. [10] vicky, wegie ruslan, and anthony riman, “optimization of combined-cycle power plant operating pattern,” rip international journal of applied engineering research, vol. 12, no. 21, pp. 11576-11582, 2017. [11] wartsila, combustion engine vs gas turbine: part load efficiency and flexibility. wartsila, 2022. [12] yunus a. cengel and michael a. boles, thermodynamics: an engineering approach. us: mcgraw hill, 5th ed, p. 584, 2004. [13] v. camacho and r. chaer, “hourly model of a combined cycle power plant for simsee,” 2020 ieee pes transmission & distribution conference and exhibition latin america (t&d la), pp. 1-5, 2020. [14] mitsubishi power, gtcc gas turbine combined cycle power plants. mitsubishi power, 2021. [15] m. olga, c. pavel and p. andrey, "combined cycle power plant control during frequency excursions," 2017 9th international conference on information technology and electrical engineering (icitee), 2017, pp. 1-5, 2017. table 5. energy saving after load optimization optimization range energy saving (mmbtu) 15/07/2019 04:27:00 to 11:34:00 450.06 22/07/2019 02:58:00 to 11:31:00 510.92 30/07/2019 09:53:00 to 11:52:00 185.11 total 1,146.09 table 6. natural gas use and price july 2019 fuel vendor ratio price ($/mmbtu) $ exchange rate (idr) pt pgn tbk 15.83 7.97 13,956.00 pt nusantara regas 22.49 10.62 bp berau ltd. 1 9.35 table 7. cost saving after load optimization description unit value fuel saving mmbtu 1,146.09 pt pgn tbk $ 3,677.46 pt nusantara regas $ 6,959.34 bp berau ltd. $ 272.46 total $ 10,909.25 idr 152,249,551.76 % cost 5.24 https://mev.lipi.go.id/ https://doi.org/10.1109/tencon.2017.8227843 https://doi.org/10.1109/tencon.2017.8227843 https://doi.org/10.1109/tencon.2017.8227843 https://doi.org/10.1109/tencon.2017.8227843 https://doi.org/10.3390/en14237916 https://doi.org/10.3390/en14237916 https://doi.org/10.3390/en14237916 https://doi.org/10.3390/en14237916 https://doi.org/10.1109/icmsc.2017.7959458 https://doi.org/10.1109/icmsc.2017.7959458 https://doi.org/10.1109/icmsc.2017.7959458 https://doi.org/10.1109/icmsc.2017.7959458 https://doi.org/10.1109/icmsc.2017.7959458 https://doi.org/10.1016/j.promfg.2019.02.248 https://doi.org/10.1016/j.promfg.2019.02.248 https://doi.org/10.1016/j.promfg.2019.02.248 https://doi.org/10.1016/j.promfg.2019.02.248 https://doi.org/10.1016/j.promfg.2019.02.248 https://doi.org/10.1109/ieem45057.2020.9309840 https://doi.org/10.1109/ieem45057.2020.9309840 https://doi.org/10.1109/ieem45057.2020.9309840 https://doi.org/10.1109/ieem45057.2020.9309840 https://doi.org/10.1109/ieem45057.2020.9309840 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.1016/j.enconman.2019.112346 https://doi.org/10.2991/seee-15.2015.19 https://doi.org/10.2991/seee-15.2015.19 https://doi.org/10.2991/seee-15.2015.19 https://doi.org/10.2991/seee-15.2015.19 https://doi.org/10.2991/seee-15.2015.19 https://www.researchgate.net/publication/286268430_improving_the_flexibility_and_efficiency_of_gas_turbine-based_distributed_power_plants https://www.researchgate.net/publication/286268430_improving_the_flexibility_and_efficiency_of_gas_turbine-based_distributed_power_plants https://www.researchgate.net/publication/286268430_improving_the_flexibility_and_efficiency_of_gas_turbine-based_distributed_power_plants http://www.ripublication.com/ijaer17/ijaerv12n21_147.pdf http://www.ripublication.com/ijaer17/ijaerv12n21_147.pdf http://www.ripublication.com/ijaer17/ijaerv12n21_147.pdf http://www.ripublication.com/ijaer17/ijaerv12n21_147.pdf https://www.wartsila.com/energy/learn-more/technical-comparisons/combustion-engine-vs-gas-turbine-part-load-efficiency-and-flexibility https://www.wartsila.com/energy/learn-more/technical-comparisons/combustion-engine-vs-gas-turbine-part-load-efficiency-and-flexibility https://books.google.co.id/books/about/thermodynamics.html?id=bkiscaaacaaj&redir_esc=y https://books.google.co.id/books/about/thermodynamics.html?id=bkiscaaacaaj&redir_esc=y https://doi.org/10.1109/tdla47668.2020.9326149 https://doi.org/10.1109/tdla47668.2020.9326149 https://doi.org/10.1109/tdla47668.2020.9326149 https://doi.org/10.1109/tdla47668.2020.9326149 https://power.mhi.com/catalogue/pdf/gtcc.pdf https://power.mhi.com/catalogue/pdf/gtcc.pdf https://doi.org/10.1109/iciteed.2017.8250445 https://doi.org/10.1109/iciteed.2017.8250445 https://doi.org/10.1109/iciteed.2017.8250445 https://doi.org/10.1109/iciteed.2017.8250445 i. introduction ii. materials and methods a. combined cycle power plant (ccpp) b. ccpp working principle c. ccpp performance 1) gas turbine (gt) heat rate and efficiency 2) steam turbine (st) heat rate and efficiency 3) net plant heat rate and net efficiency d. ccpp block 4 priok pomu 1) gt m701f4 (mhps takasago) 2 x 301.5 mw 2) hrsg (mhps kure) 3) st tc2f-40.5” (mhps nagasaki) 1 x 307.5 mw iii. results and discussions a. gt analysis b. cc analysis c. load monitoring d. determination of load configuration e. load optimization f. energy and cost saving of load optimization g. load optimization feasibility analysis iv. conclusion acknowledgment declaration author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.179-188 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: h. yudo et al., “torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 179-188, dec. 2022. torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials hartono yudo a, andi setiawan a, *, ocid mursid a, muhammad iqbal b a department of naval architecture, faculty of engineering, diponegoro university jl. prof. sudarto no.13, semarang, 50275, indonesia b department of naval architecture, ocean, and marine engineering, university of strathclyde 100 montrose street, glasgow g4 0lz, united kingdom received 7 july 2022; 1st revision 5 october 2022; 2nd revision 8 october 2022; 3rd revision 10 october 2022; 4th revision 14 october 2022; accepted 17 october 2022; published online 29 december 2022 abstract the study examined the strength of the universal joint after it was loaded with torsion. it used different materials that can withstand tensile stress in accordance with accepted principles and made modifications to the yoke as a result of the topology optimization process. the topology optimization determined that the yoke's part needed to withstand load without changing its dimensions and minimize stress distribution. according to the results, the maximum shear stress on the spider of the original universal joint model made of jis-sf590a steel was 84.57 mpa, the shear stress on the yoke component was 30.84 mpa, and the maximum von mises was 341.1 mpa. as a result of using jis-sf590a steel, yoke modification 3 has produced a reduction in shear stress of 12.97 % and a reduction in von mises stress of 35.33 % from the original yoke. this is the most efficient design of yoke and also this modified yoke form provides a wider elevation angle and is easier to manufacture. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: shear stress; topology optimization; universal joint; von mises. i. introduction the azimuth thruster system, commonly known as the z-peller, is a propulsion system that is mounted vertically and has a 3600 degrees rotation. their nozzle concentrates the water flowing around the blades. j. c. kim et al. [1] looked into the maneuverability of the azimuth thruster system on the research vessel. because of its capacity to rotate 3600, the z-peller system has remarkably high maneuverability and efficiency. some studies were carried out to study the material optimization of the steering yoke. the original universal joint and the modified universal joint with topology optimization were compared and evaluated in a. koparde et al. [2] studied with the help of finite element software. the results showed that the modified yoke provided a uniform distribution across the entire structure. this resulted in a reduction of the maximum stress by 22.9 % and a mass reduction of the yoke by 22.4 % when compared to the original yoke. the failure might be brought on by unfavorable factors, including the environment, bad planning, or unstable torque loading. according to the study by ns giridhar et al. [3], strong materials were selected and component dimensions were changed to reduce component stress and weight. the mechanism has the advantage of becoming simple to manufacture because it is constructed from two distinct sheet metals. numerous mechanisms with various dimensions are created. strong evidence suggests that the steel variant. the intricate driving motion transmission consists of a long shaft with cardan joints with variable geometry mounted on each end. the study by chaban et al. provides a system of ordinary differential equations with a combined issue of dirichlet first-type and poincaré third-type boundary conditions is utilized to represent nonlinear electromechanical differential equations [4]. the stress concentration can be reduced by fillet, but the amount of fillet provided should be optimum. pastukhov et al. [5] using the winshaft module in apm winmachine, shaft design justification, and test computations are executed based on cae tools. to * corresponding author. phone: +62-85156236032 e-mail address: andisetiawaan213@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.179-188 https://dx.doi.org/10.14203/j.mev.2022.v13.179-188 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.179-188 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.179-188&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 180 decrease speed variations between the input and output shafts, the u-joints are arranged in a zconfiguration. the study by bharti et al. is established that the sommerfeld phenomenon, which is defined by resonance capture and escape by resonance, exists for significant parallel offsets between the input and output shafts. the escape by resonance is followed by a rapid increase in speed and a decrease in the amplitude of the torsional vibration. in reality, these jump phenomena happen at two separate speed ranges, one close to the inherent frequency of the u-joints' straight-line arrangement and the other at half of it. the rate at which the input shaft torque or power is changed has an impact on the dynamic response's nature [6]. the universal joint components as shown in figure 1. zbigniew et al. [7] discovered that the elastic moment model might replicate true transient processes in the joint coordinates of the system by employing the fractional derivative integrator. furthermore, it provides accuracy on par with the model with dispersed parameters. a modified hamilton-ostrogradski concept is implemented to create shaft equations, which are then utilized to analyze both the fully coupled system and the distributed parameter system. it is utilized to calculate rotational angles of shaft elements and essential analytical mechanics functions of the velocity continuum. popenda et al. [8] investigated how the transmission shaft interacts between the working mechanism and the driving motor. the study by ekemb et al. approachs relies on analogies among mechanical and electrical systems. for the aforementioned transmission shaft, the equivalent circuits that are customary in electrical systems are defined. long and flexible shafts, which are a regular feature of synchronous motors used in lci technology, are extremely vulnerable to torsional vibration excite when their resonant frequency combine with any external load exerted on the shaft. international standards require a torsional analysis to assess the shaft's durability across the motor's entire speed range. therefore, for such an evaluation, the motor air gap torque's frequency and magnitude are necessary [9]. the dynamic characteristics of a viscous-spring damper utilized to regulate the torsional vibration of the engine's shaft system, as well as the vibration characteristics of an ultra-long-stroke engine using de-rating technology, are reviewed in this study. jaehoon et al. [10] recommended that the assigned probabilities for attempting to control torsional vibration in the propulsion shafting system would have to include adapting the design parameters of its dampening effect instead of using the optimum damper designed from concept to prevent fatigue fracture of shafts, in scenarios where ships have recently witnessed an engine acceleration issue in the critical zone. the stribeck friction curve is applied to estimate the friction force between the shaft and the water-lubricated rubber bearing. then, by using the modal synthesis method of substructures, the modal shapes of the shaft and the hull are integrated through the friction force to establish the nonlinear differential system of equations of the shaft-hull coupled system. after that, the self-excited vibration responses carried on by friction can be computed using the runge-kutta method to solve the nonlinear differential governing equations. on this base, the study by wu et al. are held regarding how the friction coefficient, damping ratio, rotation speed, and support stiffness affect the shaft-hull coupled system's self-excited vibration. the results demonstrated that the difficulty of the shaft-hull coupled system's self-excited vibration would increase as damping, shaft speed of rotation, or supporting stiffness [11]. the poles encounter both shear and torsional force as a result of the forces that are applied to them. vehicles' motion transmission mechanisms are made up of a few sections, some of which occasionally encounter severe disappointments. a rotating part is generated when forces combine, and this section is vulnerable to fragility because of fluctuating torque. the two most important components of a car are the steering mechanism and the steering column. it is a critical element for achieving the vehicle's security and steady development. it has poles that have been shaped into a cross in the center of the roadway and had loads on each of its poles that were attached in the same manner as a cross joints. it experiences torsion force in adding to shear force as a result of forces placed on the cross-joint poles. vehicles' movement transmission systems are formed of a few parts, some of which can suffer severe disappointments [12]. according to the study of cardoso et al. [13], the manufacturing process and material design, specifically the amount, location, and roughness of mechanical stakes and forks, as well as the content of microstructure inclusions, are variables that could affect fatigue life in this automobile component. a computer-aided multibody modeling approach for the simulation of a cardan joint with manufacturing errors was studied by cirelli et al. [14]. during the modeling phase, the elasticity of flexible bodies is lumped and the joint compliance is taken into account using concentrated non-linear spring elements. the torsional fluctuations in the flexible coupling dramatically increased and then abruptly ceased. the coupling connected to the intermediate shaft did not have sufficient radial flexibility to dampen these vibrations. the study of song et al. [15] concluded that to avoid the effects of the self-excited torsional vibration, it is recommended that this coupling is figure 1. universal joint components h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 181 replaced with one that is capable of absorbing the radial shaft displacement. investigation of a parallel manipulator with cardan and prismatic joints was studied by pugi et al. [16]. it is recommended that the layout involves a relatively stiff and robust structure. the manipulator is supposed to be moved by direct-drive linear actuators. this choice is justified by the possibility of accurate control of heavy insertion losses. this is done by simplifying or removing a large part of the additional actuation and sensing systems that are normally installed on conventional machines. according to the residual threshold of the associated linear systems, both reduced-order bases are enriched, and the grid resolution is adaptively determined based on the relative inaccuracy in approximating the objective function and constraint values throughout the iteration. with acceptable goal and constraint violation errors, the tests on benchmark 2d and 3d show increased performance. the impact of important stress constraint factors, thus the allowable stress value, stress penalty factor, and pnorm factor, is carefully examined by xiao et al. [17]. the gradients necessary to carry out the optimization could be computed relatively fast using the adjoint approach. gregor et al. [18] have successfully derived the gradients using a "first optimize then discretize" scheme. by enhancing the topology both of hard and soft magnetic thin film structures, the method's capabilities are proven, and the outcomes are confirmed by comparison with an analytical solution. references from previous studies and cases of mechanical failures involving universal joints are provided. using ship shaft data, one may perform a static analysis of a universal joint to calculate the shear stress, von mises, and safety factor. the yoke should be optimized by static simulations with a variety of materials that fulfill the tensile strength requirement rule. due to modifications in the form of the yoke and the material used to construct it, we will analyze the torsion strength of the universal joint. ii. materials and methods a. data to examine this study, the universal joint assembly model should be created. before doing an analysis, the dimensions of the universal joint components should be determined. the dimensions of the universal joint assembly used in this study are shown in table 1. b. material variations jis-sf590a was chosen as a material for the original yoke. based on the bki rule, we will use other materials for variation of materials in this study, where materials for shafting components must have a tensile strength of 400-800 mpa, as shown in table 2. c. yoke variations the yoke component makes an elevation angle at installation possibly. the modification of the yoke shape is considered to result in a reduced yoke mass, make manufacturing easier, and increase the elevation angle of installation. the yoke variations that will be applied involve modifying the original ship yoke shape. this will involve several modified yoke forms based on the topology optimization results and another yoke form from the previous study. the yoke variations are shown in figure 2. (a) (b) (c) (d) (e) figure 2. the yoke variations: (a) original yoke; (b) yoke modification 1; (c) yoke modification 2; (d) yoke modification 3; (e) yoke modification 4 table 1. dimension of universal joint assembly part dimension shaft diameter 130 mm universal joint length 1100 mm universal joint diameter 260 mm elevation angle 5.73° bolt type m20 x 2.5 x 80 flange length 381.5 mm flange outside diameter 350 mm h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 182 the design of figure 2(a) shows the default yoke installed on the tug boat, for the shape of the yoke in design modification 3 in figure 2(c) looks at the results of the topology study that has been done. the modified model 4 in figure 2(e) is based on the yoke shape in the research conducted by y. richard et al. [5]. meanwhile, the cutting of the middle crosssection of the yoke with dimensions of 80 mm x 10 mm in figure 2(b) and figure 2(d) sees the distribution of low stress from the simulation results. d. boundary condition and loading condition using solidworks 2020, 3d finite element model was generated. the shape of the solid meshed with tetrahedral cell technology. tetrahedral cells are very effective for solid structures because they are flexible and adapt to irregular or curved shapes. the application will support multi-core surface and volume meshing using curvature base mesh. it is excellent for meshing complex structures. figure 3 shows the mesh on the model. the torque of the main engine is calculated by dividing the power and rpm of the main engine [19] at the flange connected to the main engine, the torque of 15,174.96 nm was given at the flange connected to the main engine as shown in figure 4. in addition, boundary conditions were applied at the flange connected to the intermediate shaft, as shown in figure 5. at the flange attached to the intermediate shaft, all motions were fixed. static structural analysis was carried out using solidworks 2020 solver. e. mesh convergence mesh convergence is a method for comparing the most stable results for each element size from several stress analysis results with various element sizes. the convergence is carried out to evaluate the figure 3. meshing of model figure 4. apply moment torque location table 2. material’s mechanical properties mechanical properties astm a36 jis-sf590a aisi stainless steel 316l ss41 (bolt-nut) tensile strength 400 mpa 590 mpa 485 mpa 475 mpa yield strength 250 mpa 295 mpa 170 mpa 225 mpa density 7,850 kg.m-3 7,800 kg.m-3 8,000 kg.m-3 7,800 kg.m-3 poisson ratio 0.26 0.29 0.3 0.3 elastic modulus 200 gpa 200 gpa 173 gpa 210 gpa h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 183 software's precision. figure 6 shows the convergence of the mesh elements. at meshing diameters between 10 mm and 9 mm, mesh convergence is obtained. a meshing size of 10 m is determined with a stress value of 84.55 mpa based on the convergence results. iii. results and discussions a. topology optimization of the original yoke the optimization of the yoke is discovered using the topology optimization method. this method offers the most efficient material layout for design and loading. the solidworks 2020 topology optimization study was used to observe the element density distribution for the original yoke and identify the low-stress regions shown in figure 7. the low-stress areas that can be eliminated by paying attention to manufacturing lines, as well as certain functional constraints are shown in figure 7. the dead zone, as seen in the blue area, is where components from that region do not contribute to the workload and, therefore, can be eliminated. it must remain in the yellow area because it is required to withstand the workload placed on the models. b. simulation result on the original yoke of universal joint the torque of the main engine is calculated by dividing the power and rpm of the main engine [19]. at the flange connected to the main engine, the torque of 15,174.96 nm was given and the component was analyzed for the strength of the models. from the simulation results using the software, the largest values of shear stress and von mises stress are obtained. in the ship's universal joint assembly model using jis-sf590a material, the maximum shear stress is 84.57 mpa, located on the spider shown in figure 8. the shear stress on the yoke is 30.84 mpa and the maximum von mises stress is 341.1 mpa located on the yoke, as shown in figure 9. c. simulation result on the yoke modifications 1) comparison of shear stress result the modified yoke was analyzed for the same boundary conditions, and shear stress and von mises stress results were observed. the shear stress and von mises distribution of the modified yoke are shown in figure 10 and figure 11, respectively. figure 6. graph of mesh convergence figure 7. yoke topology study figure 5. boundary condition and moment location h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 184 the critical point in each model variation lies in the spider component. the shear stress results from static simulation for each model variation are presented in table 3, table 4 and table 5. the figure 8. the simulation analysis results oof shear stress on the original universal joint figure 9. the simulation analysis results of von mises on the original universal joint table 3. comparison of shear stress of each model with astm a36 steel model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 29.1 85.64 42.42 20.17 yoke modification 1 28.44 84.96 86.75 20.28 yoke modification 2 27.32 84.84 41.69 20.15 yoke modification 3 27.13 84.89 38.54 20.28 yoke modification 4 27.92 84.79 85.35 20.15 table 4. comparison of shear stress of each model with jis-sf590a steel model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 30.84 84.57 43.33 21.05 yoke modification 1 28.08 84.63 85.85 21.3 yoke modification 2 27.03 84.52 41.36 21.04 yoke modification 3 26.84 84.56 38.45 21.29 yoke modification 4 27.63 84.47 84.54 21.04 table 5. comparison of shear stress of each model with aisi stainless steel 316l model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 29.37 84.84 42.41 20.31 yoke modification 1 28.38 84.91 86.6 20.45 yoke modification 2 27.27 84.79 41.68 20.3 yoke modification 3 27.01 84.84 38.53 20.3 yoke modification 4 27.87 84.74 85.22 20.3 h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 185 maximum shear stress obtained using the model's variation is significantly below the astm a36 material's yield strength 250 mpa. the reduction of shear stress on the yoke is 6.77 % compared with the original yoke, as shown in the modified model of yoke 3. the maximum stress obtained in the model variation is significantly lower than the 295 mpa yield strength of the jis-sf590a material. the shear stress on the yoke of the modified model 3 has been reduced by 12.97 %. the maximum stress obtained in the model variation is significantly lower than 170 mpa yield strength for aisi stainless steel 316l material. the shear stress reduction on the yoke is 8.035 %, which can be seen in the modified model of yoke 3. the results obtained by numerical analysis of the stress distribution at the input yoke of the universal joint showed that even small variations in shape could cause significant variations in the stress distribution. therefore, topology optimization is carried out to obtain the efficiency of stress distribution on the yoke. the case with the lowest voltage level is identified and selected as the most profitable design solution. based on the shear stress analysis results from all the variations presented, the yoke modification 3 with jis-sf590a steel has the greatest stress reduction compared to other variations, amounting to 12.97 %. 2) comparison of von mises result the critical point of von mises stress in each variation model lies in the eye pad of the yoke component. the results of von mises stress simulation results for each model variation are presented in table 6, table 7, and table 8. the von mises stress has been reduced by 34.81 % using the modified model of yoke 3 compared to the ship's original yoke. it can be seen that when compared to the ship's original yoke, the modified yoke 3 model has 35.33 % von mises stress reduction. compared to the ship's original yoke, the redesigned model of yoke 3 has a 34.20 % lower von mises stress. the results of the numerical analysis of the stress distribution at the universal joint's input yoke revealed that even minor shape changes may result in significant modifications in the stress distribution. the yoke modification 3 with jissf590a steel has the greatest stress reduction compared to other variations, equal to 35.33 %, based on the von mises stress analysis results from all the variants shown. 3) comparison of safety factors the safety factor criteria for universal joint components based on the bki rule that applies to main shafting components is 1 [20]. the safety factor figure 10. the simulation analysis results of shear stress on the modified yoke figure 11. the simulation analysis results of von mises on the modifies yoke h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 186 calculation can be obtained compared to the yield strength of the material with the results of von mises stress must be higher than 1 [19]. components like the yoke, spider, and driveshaft of universal joints must comply with that safety factor criteria. figure 12 shows the yoke safety factor data for each model. it is known that only modifications 1, 3, and 4, manufactured with jis-sf590a material, as well as modifications model 3 manufactured of astm a36, are yoke components that fulfill the safety factor criteria. figure 13 shows the spider safety factor. only the original yoke model and the variations of table 6. comparison of von mises stress of each model with astm a36 steel model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 348.8 184.8 173.1 53.81 yoke modification 1 229.3 184.9 157.3 53.9 yoke modification 2 351.1 184.7 150.3 54.8 yoke modification 3 227.4 184.7 155.9 53.89 yoke modification 4 277.1 184.2 149.8 53.81 table 7. comparison of von mises stress of each model with jis-sf590a steel model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 341.1 181.9 172.1 53.5 yoke modification 1 222.9 182 156.2 53.57 yoke modification 2 338.5 181.8 150 53.49 yoke modification 3 220.6 181.8 155.5 53.56 yoke modification 4 270.5 181.8 149.9 53.5 table 8. comparison of von mises stress of each model with aisi stainless steel 316l model yoke (mpa) spider (mpa) driveshaft (mpa) flange (mpa) original yoke model 344.2 184.3 172.9 53.76 yoke modification 1 228.3 184.4 157.3 53.85 yoke modification 2 249.2 184.2 150.2 53.75 yoke modification 3 226.5 184.2 124.5 53.83 yoke modification 4 276.2 184.2 149.9 53.75 figure 12. graph of yoke component safety factor with several materials figure 13. graph of spider component safety factor with several materials h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 187 yoke modification with aisi stainless steel 316l are the spider components that do not fulfill the safety factor criteria. figure 14 shows the driveshaft safety factor. according to the bki rule, which applies to main shafting components, the safety factor requirement for universal joint components is 5 [20]. it can be seen that the flange components comply with the safety factor criteria for all models. figure 15 shows the results of the safety factor of the flange for each model. iv. conclusion based on the analysis results, it can be concluded that the jis-sf590a material used in the ship's universal joint model has maximum shear stress of 30.84 mpa and a von mises stress of 341.1 mpa, which is found on the eye yoke pad. the original yoke will obtain the element density of stress distribution by topology optimization. in the modified yoke 3 models, there is a reduction of 35.33 % in von mises and 12.97 % in the shear stress of the yoke component, respectively. each universal joint component made of astm a36 and jis-sf590a materials has fulfilled the safety factor criteria. the modified yoke 3 has a very good shape in terms of strength because it has minimal stress. its design also provides a greater elevation angle than the original ship yoke model, making it easier to manufacture and install. acknowledgments this research is supported by department of naval architecture, faculty of engineering, diponegoro university, semarang, indonesia. we are also immensely grateful to all researcher who is joined in this research. declaration author contribution andi setiawan: writing & editing, conceptualization, formal analysis, investigation, resources, visualization. hartono yudo, ocid mursid, and muhammad iqbal: review & editing, supervision funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. figure 14. graph of driveshaft component safety factor with several materials figure 15. graph of flange component safety factor with several materials https://mev.lipi.go.id/ h. yudo et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 179-188 188 references [1] j.c. kim, i.k. kang, j.h. lee, s.j. ham, c.w. park, and s.h. kim, ”the maneuvering characteristics of the research vessel nara equipped with the azimuth thruster system,” j. korean soc. fish. technol., vol. 53, no. 3, pp. 276–285, 2017. [2] a. koparde, n. mithra, and s. ahankari, “numerical and experimental analysis of torsional stress of traditional and modified steering yoke,”” mater. today proc., vol. 46, pp. 7099–7104, 2021. [3] n. s. giridhar, s. hetawal, and p. baskar, “finite element analysis of universal joint and propeller shaft assembly,” vol. 5, no. 5, pp. 226–229, 2013. [4] a. chaban, z. łukasik, a. popenda, and a. szafraniec, “mathematical modelling of transient processes in an asynchronous drive with a long shaft including cardan joints,” energies, vol. 14, no. 18, 2021. [5] a. lozynskyy, a. chaban, t. perzyński, a. szafraniec, and l. kasha, “application of fractional-order calculus to improve the mathematical model of a two-mass system with a long shaft,” energies, vol. 14, no. 7, 2021. [6] s. k. bharti and a. k. samantaray, “resonant capture and sommerfeld effect due to torsional vibrations in a double cardan joint driveline,” commun. nonlinear sci. numer. simul., vol. 97, p. 105728, 2021. [7] ł. zbigniew, c. andriy, s. andrzej, and ż. vołodymyr,” model matematyczny układu napędowego z silnikiem asynchronicznym i pompą pionową,” prz. elektrotechniczny, vol. 94, no. 1, pp. 133–138, 2018. [8] a. popenda, m. lis, m. nowak, and k. blecharz, “mathematical modelling of drive system with an elastic coupling based on formal analogy between the transmission shaft and the electric transmission line,” energies, vol. 13, no. 5, 2020. [9] g. ekemb, f. slaoui‐hasnaoui, j. song‐manguelle, p. m. lingom, and i. fofana,” instantaneous electromagnetic torque components in synchronous motors fed by load‐commutated inverters,” energies, vol. 14, no. 11, 2021. [10] j. jee, c. kim, and y. kim, “design improvement of a viscousspring damper for controlling torsional vibration in a propulsion shafting system with an engine acceleration problem,” j. mar. sci. eng., vol. 8, no. 6, 2020. [11] c. wu, f. chen, and x. long, “the self-excited vibration induced by friction of the shaft-hull coupled system with the water-lubricated rubber bearing and its stick-slip phenomenon,” ocean eng., vol. 198, p. 107002, 2020. [12] a. kohli, m. hombalmath, a. y. patil, and p. c. aruna kumara, “analysis of universal joint using virtual simulation method,” mater. today proc., vol. 59, pp. 858–866, 2022. [13] a. s. m. cardoso et al., “fatigue resistance performance of universal cardan joint for automotive application,” eng. fail. anal., vol. 135, no. february, p. 106128, 2022. [14] m. cirelli, v. rossi, p. p. valentini, and e. pennestrì, “a dynamic model of a cardan joint to evaluate the effect of elasticity and manufacturing errors,” int. j. veh. perform., vol. 7, no. 1–2, pp. 136–155, 2021. [15] m. song, t. nam, and j. lee, “self-excited torsional vibration in the flexible coupling of a marine propulsion shafting system employing cardan shafts,” pp. 1–13, 2020. [16] l. pugi, l. fiorineschi, and f. rotini, “preliminary design investigation of a rrprr parallel manipulator with cardan joint and direct drive actuation,” ieee/asme int. conf. adv. intell. mechatronics, aim, vol. 2021-july, pp. 1207–1212, 2021. [17] m. xiao, j. ma, d. lu, b. raghavan, and w. zhang, “stressconstrained topology optimization using approximate reanalysis with on-the-fly reduced order modeling,” adv. model. simul. eng. sci., vol. 9, no. 1, 2022. [18] g. wautischer, c. abert, f. bruckner, f. slanovc, and d. suess, “a topology optimization algorithm for magnetic structures based on a hybrid fem–bem method utilizing the adjoint approach,” sci. rep., vol. 12, no. 1, pp. 1–11, 2022. [19] e. p. popov, mechanics of solids. p. 106, prentice hall inc., 2nd edition, 1976. [20] bki, rules for machinery installations edition 2021. vol. vi, 2021. https://doi.org/10.3796/ksft.2017.53.3.276 https://doi.org/10.3796/ksft.2017.53.3.276 https://doi.org/10.3796/ksft.2017.53.3.276 https://doi.org/10.3796/ksft.2017.53.3.276 https://doi.org/10.1016/j.matpr.2020.10.167 https://doi.org/10.1016/j.matpr.2020.10.167 https://doi.org/10.1016/j.matpr.2020.10.167 https://doi.org/10.1016/j.matpr.2020.10.167 https://ijettjournal.org/archive/ijett-v5n5p142 https://ijettjournal.org/archive/ijett-v5n5p142 https://ijettjournal.org/archive/ijett-v5n5p142 https://doi.org/10.3390/en14185692 https://doi.org/10.3390/en14185692 https://doi.org/10.3390/en14185692 https://doi.org/10.3390/en14185692 https://doi.org/10.3390/en14071854 https://doi.org/10.3390/en14071854 https://doi.org/10.3390/en14071854 https://doi.org/10.3390/en14071854 https://doi.org/10.1016/j.cnsns.2021.105728 https://doi.org/10.1016/j.cnsns.2021.105728 https://doi.org/10.1016/j.cnsns.2021.105728 https://doi.org/10.1016/j.cnsns.2021.105728 https://doi.org/10.15199/48.2018.01.34 https://doi.org/10.15199/48.2018.01.34 https://doi.org/10.15199/48.2018.01.34 https://doi.org/10.15199/48.2018.01.34 https://doi.org/10.3390/en13051181 https://doi.org/10.3390/en13051181 https://doi.org/10.3390/en13051181 https://doi.org/10.3390/en13051181 https://doi.org/10.3390/en14113223 https://doi.org/10.3390/en14113223 https://doi.org/10.3390/en14113223 https://doi.org/10.3390/en14113223 https://doi.org/10.3390/jmse8060428 https://doi.org/10.3390/jmse8060428 https://doi.org/10.3390/jmse8060428 https://doi.org/10.3390/jmse8060428 https://doi.org/10.1016/j.oceaneng.2020.107002 https://doi.org/10.1016/j.oceaneng.2020.107002 https://doi.org/10.1016/j.oceaneng.2020.107002 https://doi.org/10.1016/j.oceaneng.2020.107002 https://doi.org/10.1016/j.matpr.2022.01.213 https://doi.org/10.1016/j.matpr.2022.01.213 https://doi.org/10.1016/j.matpr.2022.01.213 https://doi.org/10.1016/j.engfailanal.2022.106128 https://doi.org/10.1016/j.engfailanal.2022.106128 https://doi.org/10.1016/j.engfailanal.2022.106128 https://doi.org/10.1504/ijvp.2021.113423 https://doi.org/10.1504/ijvp.2021.113423 https://doi.org/10.1504/ijvp.2021.113423 https://doi.org/10.1504/ijvp.2021.113423 https://doi.org/10.3390/jmse8050348 https://doi.org/10.3390/jmse8050348 https://doi.org/10.3390/jmse8050348 https://doi.org/10.1109/aim46487.2021.9517628 https://doi.org/10.1109/aim46487.2021.9517628 https://doi.org/10.1109/aim46487.2021.9517628 https://doi.org/10.1109/aim46487.2021.9517628 https://doi.org/10.1186/s40323-022-00231-x https://doi.org/10.1186/s40323-022-00231-x https://doi.org/10.1186/s40323-022-00231-x https://doi.org/10.1186/s40323-022-00231-x https://doi.org/10.1038/s41598-021-04246-z https://doi.org/10.1038/s41598-021-04246-z https://doi.org/10.1038/s41598-021-04246-z https://doi.org/10.1038/s41598-021-04246-z http://www.vssut.ac.in/lecture_notes/lecture1423904647.pdf http://www.vssut.ac.in/lecture_notes/lecture1423904647.pdf https://servrules.bki.co.id:81/data/(%20vol%20iii%20),2022%20rules%20for%20machinery%20installations%20(en),2022.pdf https://servrules.bki.co.id:81/data/(%20vol%20iii%20),2022%20rules%20for%20machinery%20installations%20(en),2022.pdf introduction ii. materials and methods a. data b. material variations c. yoke variations d. boundary condition and loading condition e. mesh convergence results and discussions a. topology optimization of the original yoke b. simulation result on the original yoke of universal joint c. simulation result on the yoke modifications 1) comparison of shear stress result 2) comparison of von mises result 3) comparison of safety factors conclusion acknowledgments declaration references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.80-86 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: a. jaya et al., “design and implementation of capacitor array as dc converters for electrical lighting in limited area,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 80-86, july 2023. design and implementation of capacitor array as dc converters for electrical lighting in limited area arman jaya a, *, irianto a, afif aulia rahman a, kyungmin sung b a departement of electrical engineering, electronic engineering polytechnic institute of surabaya keputih sukolilo, surabaya, indonesia b national institute of technology, ibaraki college 866 nakane, hitachinaka-shi, ibaraki-ken 312-8508, japan received 20 march 2023; 1st revision 10 july 2023; 2nd revision 12 july 2023; accepted 13 july 2023; published online 31 july 2023 abstract the widely used dc-dc converters are inductor-based dc-dc converters and inductors along with combustion. the use of inductors can lead to large power losses, as well as heavy components in real terms. the proposed converter warning array aims to increase the voltage with a large increase ratio through a switching configuration process. this switching method is very simple and uses two pulses that are opposite each other so that the array converter can work optimally, whose function is to adjust the arrangement in a parallel arrangement to a series arrangement. the advantage of using a device is that it makes dc-based dc conversion lightweight and easy to implement. tests have been carried out on 5 hanger arrays with a power of 80 w and 65 w, and the data from the test results show that the voltage increase ratio reaches 81.5 % or 4.08 times the input voltage, which indicates that the array converter warning is able to increase the input voltage according to the number of the arrays. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: inductor-based converter; inductor and capacitor-based converter; capacitor array. i. introduction at this time, the use of dc converters to increase and or decrease the input voltage is widely used in several applications such as dc houses, battery charging, and so on. dc converters that have been widely implemented are dc converters that use inductors [1][2]. this type of converter can increase and decrease the input voltage by using a variable duty cycle ratio [3] as well as using the transformer winding ratio for a significant increase in voltage levels. in addition, during switching transitions, it can cause transformer leakage at high frequencies [4][5], as well as requiring an air gap to prevent core saturation due to high dc currents [6][7]. to raise the ratio level to a high level also developed a converter that combines the functions of the inductor and capacitor [8][9], as also represented by [10][11] the structure uses two inductors assisted by a transformer ratio for the input voltage step of 45 v to 450 v output from the capacitor. in [12][13] it was also introduced the use of 2 inductors and a pump capacitor at the input to store and distribute energy to the load. however, in addition to this complicated converter and the presence of power losses due to switching, it can reduce the performance of this converter [14]. a switching capacitor converter has been introduced in [15], which focuses on the characteristics of the switching process. in [16][17] a switching capacitor converter that analyzes the power loss during the switching transition is also introduced. the switching capacitor converter that was introduced before has not analyzed the increase in the resulting input voltage over a larger range, some at zero voltage switching [18]. the topology introduced focuses on analyzing the increase in input voltage based on the arrangement of capacitors using the capacitor switching method. in addition to the components used is quite simple, using only mosfets and capacitors, systems that are lightweight and also have high efficiency, as well as smaller switching losses [19][20], the topology * corresponding author. tel: +62-811-309-592 e-mail address: arman@pens.ac.id https://dx.doi.org/10.14203/j.mev.2023.v14.80-86 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.80-86 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 81 introduced also has a different structure, where the capacitor is charged in a parallel configuration, and discharged in a series configuration, to generate an output voltage equal to the input voltage multiplied by the number of capacitor arrangements. ii. materials and methods the input voltage level is increased by a capacitor array using two switching configurations that function to change the arrangement of the capacitor. capacitor charging is regulated through a number of switches for parallel configuration, while the increase in voltage level occurs when the capacitor is in series. figure 1 shows the use of microcontrollers. in this system, namely to generate pwm opposite each other visited on mosfet drivers with specifications that are able to accept switching with high frequencies, so that the switching configuration on the capacitor converter array can work optimally. the proposed capacitor array, as shown in figure 2, has 5 total capacitor arrangements with 1 buffer capacitor. the capacitor array charges when switches q1, q3, q5, q7, q9 is on and switches q2, q4, q6, q8 is off. d1, d2, d3, and d4 are forward biased, so that the capacitor in parallel arrangement with the amount of charging voltage can be calculated by the equation (1) and equation (2), 𝑉𝐶(𝑡) = 𝑉𝑠(𝑡)(1 − 𝑒 −𝑡 𝑅𝑅) (1) where 𝑉𝐶(𝑡) is charging voltage across the capacitor (v), 𝑉𝑠(𝑡) is input voltage (v), rc is time constant (s), t is charging time in capacitor (s), 𝑒 is euler’s number is 2.7182. 𝑉𝐶1 = 𝑉𝐶2 = 𝑉𝐶3 = 𝑉𝐶4 = 𝑉𝐶5 = 0.99𝑉𝑖𝑖 (2) where 𝑉𝐶1 = 𝑉𝐶2 = 𝑉𝐶3 = 𝑉𝐶4 = 𝑉𝐶5 is voltage across capacitors 1 to 5 (v). to raise the input voltage level, the capacitor releases its charge to the load when the switches q2, q4, q6, and q8 are on and switches q1, q3, q5, q7, and q9 are off. d1, d2, d3, and d4 reverse biased, so that the capacitors are in series. the amount of voltage received by the buffer capacitor is the sum of the discharge voltages on each capacitor, calculated by the equation (3), 𝑉𝑜(𝑡) = 𝑉𝐶(𝑡) × 𝑒 −𝑡 𝑅𝑅 (3) where 𝑉𝑜(𝑡) is output voltage capacitor (v), 𝑉𝐶(𝑡) is the voltage is stored in the capacitor (v), rc is time constant (s), t is charging time in capacitor (s), 𝑒 is euler’s number 2.7182. figure 3(a) and figure 3(b) show the operating principle of the capacitor array. the capacitor array has 5 total capacitors with two circuit configurations as shown in figure 3. in charging mode, the capacitors are in a parallel configuration, and the voltage across capacitor 1 is equal to capacitors 2 to 5. in ideal conditions, the charging voltage across the capacitor is equal to the input voltage, which is 24 vdc. this is in accordance with the nature of the capacitor, which is that it can store voltage according to the input given. in discharging mode, the capacitors are in a series configuration. the voltage stored on each capacitor accumulates and the output voltage is 5 times the input voltage, according to the series configuration in figure 3. figure 1. block diagram of the capacitor array system figure 2. array capacitor topology a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 82 the buffer capacitor value of the capacitor array must be able to accommodate the total voltage resulting from the sum of the voltage multiplier capacitors, so as to design the buffer capacitor value using the highest power of the load to be used. the amount of the buffer capacitor can be calculated by equation (4), 𝐶𝑏𝑏𝑏𝑏 ≫ 𝑃𝑜 1 2𝑉𝑜 2 (4) where 𝐶𝑏𝑏𝑏𝑏 is buffer capacitor (µf), 𝑃𝑜 is capacitor output power (w), 𝑉𝑜(𝑡) is capacitor output voltage (v) iii. results and discussions the proposed system is built using component specifications as shown in table 1. figure 4 is a summary of the work system of the capacitor array, which has 5 process stages. from this process, the importance of the mosfet driver so that the capacitor array can optimally work in parallel and series configurations. the parameters above are the parameters used in the converter capacitor array system with the component specifications that have been taken into account. the most important part of this system is maximizing the performance of the switching generated by the microcontroller via the mosfet driver. the use of irfp460 mosfet type is able to handle high switching frequencies up to 1 mhz, so it is safe during prototype testing. (a) (b) figure 3. (a) array capacitor charging; (b) array capacitor discharging table 1. array capacitor parameters parameter unit dc input voltage 24 v dc ouput voltage 110 v switching frekuensi minimum 5 khz capacitor 22 µf capacitor buffer 10 kµf diode mur1560 (fast recovery) switch q mosfet irf460 figure 4. flowchart experiment array capacitor a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 83 the testing process uses a power supply as the input voltage and a load of 3 lamps arranged in parallel, which are turned on alternately to regulate the amount of load power that must be supplied by the capacitor array. the experiment uses 2 voltmeters installed at the input and output of the capacitor array to determine the actual increase in the input voltage ratio. the magnitude of the switching frequency is controlled using a microcontroller, according to table 2. figure 5 represents the hardware designed to the specifications in table 1, with a minimum planned switching frequency of 5 khz, which is passed on to the mosfet driver. the mur 1560 fast recovery diode functions as a controlless switch when the capacitor is in a parallel configuration. the capacitor used is 22 μf with a voltage capacity of 400 v, in order to be able to receive input voltage when the charging process is in a high frequency of 20 khz. table 2 shows the data from the test results of the array capacitor at a load of 80 w and 65 w. input voltage is increased in 2 volt steps from 8v to 24v at each switching frequency of 5 khz to 20 khz. for a power of 80 w at a nominal input voltage of 24 v, the resulting output voltage reaches 3.8 times the input voltage. there is a difference in the power of 65 w at a nominal input voltage of 24 v, reaching multiples of 4.07 times. the switching frequency affects the amount of charging current in the capacitor when the parallel configuration is configured. the magnitude of the switching frequency is proportional to the magnitude of the charging current in the capacitor because the capacitor is forced to charge in a faster time which causes heat in the capacitor. this can be seen at a power of 80 w. a switching frequency of 20 khz reduces the ratio of the increase in input voltage, due to the inability of the capacitor to receive a charging current that is too large. figure 6 is an image of the testing process of the capacitor array at figure 5. array capacitor prototype table 2. data from testing the capacitor array for 80 w and 65 w power f (khz) 𝑽𝒊𝒊 (v) 𝑰𝒊𝒊 (a) 𝑽𝒐𝒐𝒐 (v) 𝑰𝒐𝒐𝒐 (a) 𝑽𝒐 𝑽𝒊𝒊 𝑷𝒐𝒐𝒐 (w) load 5 8 2.51 21.4 0.43 2.6 9.21 80 w 12 3.28 38.6 0.54 3.2 20.8 16 3.4 56.6 0.64 3.5 36.2 20 4.5 74.7 0.74 3.7 55.3 24 5.17 96 0.84 3.9 79.9 10 8 2.82 21.9 0.43 2.7 9.43 12 3.71 39 0.54 3.24 21.0 16 4.5 57 0.65 3.55 37.1 20 5.16 75.4 0.74 3.75 55.7 24 5.78 97 0.83 3.91 80.8 20 8 7.39 20.4 0.37 2.52 8.58 12 11 36.7 0.47 3.05 19.4 16 14.87 54.5 0.58 3.4 34.3 20 18.72 72.7 0.68 3.62 53.0 24 23.08 93.5 0.77 3.8 77.6 5 8 1.87 24.1 0.309 2.97 7.45 65 w 12 2.55 41.5 0.40 3.45 16.8 16 3.15 59.3 0.496 3.69 29.4 20 3.64 78.2 0.57 3.89 44.6 24 4.15 99.8 0.65 4.05 64.7 10 8 2.28 24.3 0.31 2.99 7.48 12 3.12 41.9 0.41 3.47 16.7 16 3.86 59.8 0.49 3.71 29.3 20 4.44 78.6 0.57 3.89 44.6 24 4.97 100 0.65 4.07 65.2 20 8 3.2 22.3 0.29 2.75 6.43 12 4.56 38.5 0.39 3.2 15 16 5.63 56.4 0.43 3.51 27.0 20 6.45 74.2 0.56 3.69 41.5 24 7.12 96 0.64 3.91 61.8 a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 84 a switching frequency of 20 khz and a load of 80 w. this test uses a power supply with a capacity of 450 w with input voltage steps, as shown in table 2. in addition, the capacitor array has also been simulated using psim software to compare the simulation results with direct hardware testing with the same capacity and specifications. the following is a comparison of the simulation results. figure 7 shows the experimental results at a maximum power of 100 w. minimum switching frequency given is 5 khz and varied up to 20 khz can be seen in the simulation comparison results. at minimum frequency, the simulation voltage ratio reaches 81.58 %, while the hardware test results reach 80 %. the maximum increase level achieved on hardware is 10 khz with an increased ratio of 81.05 %, while the simulation is higher, namely 86.3 %. there is a saturation of the capacitor at a frequency of 15 khz, which causes a decrease in the increase in the voltage ratio of 79.1 %. this is due to the inability of the capacitor to accept large charging currents at a frequency of 15 khz. so that when the frequency is increased to 20 khz, the reduction ratio is even greater, reaching 77 %. the effect of an extensive charging current can increase the temperature of the capacitor if, for a long time, it can reduce the resistance of the capacitor. in the test conditions above, the maximum frequency that the capacitor can receive to work optimally is 15 khz. this means that to increase the input voltage from the power supply, the optimal frequency must be given 15 khz. the comparative results of hardware testing and simulation have shown that the converter capacitor figure 6. array capacitor test (a) (b) figure 7. (a) comparison of simulation and hardware on changes in switching frequency; (b) comparison of the ratio of the simulated output voltage level andthe hardware at a change in input voltage f 10 khz 97.9 103.6 108 112 96 98 95 94 92 94 96 98 100 102 104 106 108 110 112 114 0 5 10 15 20 25 o u tp u t v o lt ag e (v ) switching frequency (khz) simulation hardware 39.5 51.2 68.7 84.6 103.8 21.4 38.6 56.6 74.7 96 0 20 40 60 80 100 120 0 5 10 15 20 25 30 o u tp u t v o lt ag e (v ) input voltage (v) simulation hardware a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 85 array has succeeded in increasing the input voltage up to 4 times by using the switching method. it can be seen that the comparison of the percentage increase between the simulation and the hardware is quite small at each switching frequency. at a frequency of 10 khz, as shown in table 2, it is known that the capacitor array is capable of supplying power according to the design, namely a maximum of 80 w, with a generated power of 80.8 w. generated by the capacitor array of 65.2 w. while the comparison of the results of the ratio of the increase in the output voltage of the simulation and hardware as shown in figure 7, that the simulation has a greater increase ratio of 5 % compared to the hardware test results because the components used in the simulation are in ideal conditions so that there is no diode voltage drop even in the switching process, whereas, at the knee voltage hardware on the diode, the presence of a large switching frequency becomes a factor in reducing the increase in output voltage ratio. iv. conclusion the results of the capacitor array have been discussed in section 3, which shows that the capacitor array is able to increase the voltage up to 4 times the input voltage of 24 vdc, with a percentage of 81.05 % in hardware and 86.3 % in the simulation, which shows that the switching capacitor method successfully configures the array of the capacitor to increase the voltage. in addition, the capacitor array is capable of supplying 80 w of power with an output voltage of 98 vdc with an increase in voltage level ratio of 3.9 times the input voltage. at 65 w, the output voltage of the capacitor array reaches 100 vdc and the gain ratio is 4 times that of the input voltage. acknowledgements this research is for the final project of the industrial electrical engineering study program at surabaya state electronics polytechnic with the hope that it can be implemented in areas with limited electricity. the author would like to thank the supervisors who have guided and provided input and participated in supporting the realization of this tool. declarations author contribution a. jaya: conceptualization, formal-analysis, writingconcept, review & advisor, validation. a.a. rahman: writing, define-parameter-componen, original-draft, editing, data-simulation. irianto and k. sung: finishing, conceptualization, advisor, validation. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] m. r. banaei and h. a. f. bonab, “a high efficiency nonisolated buck-boost converter based on zeta converter,” ieee trans. ind. electron., vol. 67, no. 3, pp. 1991–1998, 2020. [2] a. alzahrani, m. ferdowsi, and p. shamsi, “a family of scalable non-isolated interleaved dc-dc boost converters with voltage multiplier cells,” ieee access, vol. 7, pp. 11707–11721, 2019. [3] x. weng et al., “comprehensive comparison and analysis of non‐inverting buck boost and conventional buck boost converters,” j. eng., vol. 2019, no. 16, pp. 3030–3034, 2019. [4] k. nathan, s. ghosh, y. siwakoti, and t. long, “a new dc-dc converter for photovoltaic systems: coupled-inductors combined cuk-sepic converter,” ieee trans. energy convers., vol. 34, no. 1, pp. 191–201, 2019. [5] p. alavi, p. mohseni, e. babaei, and v. marzang, “an ultra-high step-up dc-dc converter with extendable voltage gain and soft-switching capability,” ieee trans. ind. electron., vol. 67, no. 11, pp. 9238–9250, 2020. [6] s. chen et al., “research on topology of the high step-up boost converter with coupled inductor,” ieee trans. power electron., vol. 34, no. 11, pp. 10733–10745, 2019. [7] s. pourjafar, f. sedaghati, h. shayeghi, and m. maalandish, “high step-up dc-dc converter with coupled inductor suitable for renewable applications,” iet power electron., vol. 12, no. 1, pp. 92–101, 2019. [8] a. jaya, f. d. murdianto, e. purwanto, and a. rachmatdianto, “ultra step up converter using fuzzy sugeno on hvdc application,” proc. icaiti 2019 2nd int. conf. appl. inf. technol. innov. explor. futur. technol. appl. inf. technol. innov., pp. 82–87, 2019. [9] ghabeli sani, s. et al., “design and implementation of a new high step ‐ up dc ‐ dc converter for renewable applications,” int. j. circ. theor. appl., no. 47, pp. 464-482, 2019. [10] p. mohseni, s. h. hosseini, m. maalandish, and m. sabahi, “ultra-high step-up two-input dc-dc converter with lower switching losses,” iet power electron., vol. 12, no. 9, pp. 2201– 2213, 2019. [11] t. jalilzadeh, n. rostami, e. babaei, and m. maalandish, “ultrastep-up dc-dc converter with lowvoltage stress on devices,” iet power electron., vol. 12, no. 3, pp. 345–357, 2019. [12] v. marzang, s. h. hosseini, n. rostami, p. alavi, p. mohseni, and s. m. hashemzadeh, “a high step-up nonisolated dc-dc converter with flexible voltage gain,” ieee trans. power electron., vol. 35, no. 10, pp. 10489–10500, 2020. [13] b. faridpak, m. bayat, m. nasiri, r. samanbakhsh, and m. farrokhifar, “improved hybrid switched inductor/switched capacitor dc-dc converters,” ieee trans. power electron., vol. 36, no. 3, pp. 3053–3062, 2021. [14] m. meraj, m. s. bhaskar, a. iqbal, n. al-emadi, and s. rahman, “interleaved multilevel boost converter with minimal voltage multiplier components for high-voltage step-up applications,” ieee trans. power electron., vol. 35, no. 12, pp. 12816–12833, 2020. [15] de souza af et al. “switched capacitor dc-dc converters : a survey on the main topologies, design characteristic, and applications,” energies, 14(8), 2231, 2021. [16] n. v. kurdkandi et al., “design and analysis of a switchedcapacitor dc-dc converter with variable conversion ratio,” int. j. circ. theor. appl., 48, 1638-1657, 2020. [17] y. sato, m. uno, and h. nagata, “nonisolated multiport converters based on integration of pwm converter and phaseshift switched capacitor converter,” in ieee transactions on power electronics, vol. 35, no. 1, pp. 455-470, jan, 2020. https://mev.lipi.go.id/ https://doi.org/10.1109/tie.2019.2902785 https://doi.org/10.1109/tie.2019.2902785 https://doi.org/10.1109/tie.2019.2902785 https://doi.org/10.1109/access.2019.2891625 https://doi.org/10.1109/access.2019.2891625 https://doi.org/10.1109/access.2019.2891625 https://doi.org/10.1049/joe.2018.8373 https://doi.org/10.1049/joe.2018.8373 https://doi.org/10.1049/joe.2018.8373 https://doi.org/10.1109/tec.2018.2876454 https://doi.org/10.1109/tec.2018.2876454 https://doi.org/10.1109/tec.2018.2876454 https://doi.org/10.1109/tec.2018.2876454 https://doi.org/10.1109/tie.2019.2952821 https://doi.org/10.1109/tie.2019.2952821 https://doi.org/10.1109/tie.2019.2952821 https://doi.org/10.1109/tie.2019.2952821 https://doi.org/10.1109/tpel.2019.2897871 https://doi.org/10.1109/tpel.2019.2897871 https://doi.org/10.1109/tpel.2019.2897871 https://doi.org/10.1049/iet-pel.2018.5414 https://doi.org/10.1049/iet-pel.2018.5414 https://doi.org/10.1049/iet-pel.2018.5414 https://doi.org/10.1049/iet-pel.2018.5414 https://doi.org/10.1109/icaiti48442.2019.8982157 https://doi.org/10.1109/icaiti48442.2019.8982157 https://doi.org/10.1109/icaiti48442.2019.8982157 https://doi.org/10.1109/icaiti48442.2019.8982157 https://doi.org/10.1109/icaiti48442.2019.8982157 https://doi.org/10.1002/cta.2593 https://doi.org/10.1002/cta.2593 https://doi.org/10.1002/cta.2593 https://doi.org/10.1049/iet-pel.2018.5924 https://doi.org/10.1049/iet-pel.2018.5924 https://doi.org/10.1049/iet-pel.2018.5924 https://doi.org/10.1049/iet-pel.2018.5924 https://doi.org/10.1049/iet-pel.2018.5356 https://doi.org/10.1049/iet-pel.2018.5356 https://doi.org/10.1049/iet-pel.2018.5356 https://doi.org/10.1109/tpel.2020.2976829 https://doi.org/10.1109/tpel.2020.2976829 https://doi.org/10.1109/tpel.2020.2976829 https://doi.org/10.1109/tpel.2020.2976829 https://doi.org/10.1109/tpel.2020.3014278 https://doi.org/10.1109/tpel.2020.3014278 https://doi.org/10.1109/tpel.2020.3014278 https://doi.org/10.1109/tpel.2020.3014278 https://doi.org/10.1109/tpel.2020.2992602 https://doi.org/10.1109/tpel.2020.2992602 https://doi.org/10.1109/tpel.2020.2992602 https://doi.org/10.1109/tpel.2020.2992602 https://doi.org/10.1109/tpel.2020.2992602 https://doi.org/10.3390/en14082231 https://doi.org/10.3390/en14082231 https://doi.org/10.3390/en14082231 https://doi.org/10.1002/cta.2849 https://doi.org/10.1002/cta.2849 https://doi.org/10.1002/cta.2849 https://doi.org/10.1109/tpel.2019.2912550 https://doi.org/10.1109/tpel.2019.2912550 https://doi.org/10.1109/tpel.2019.2912550 https://doi.org/10.1109/tpel.2019.2912550 a. jaya et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 80-86 86 [18] s. folmer and r. stala, “dc-dc high voltage gain switched capacitor converter with multilevel output voltage and zerovoltage switching,” in ieee access, vol. 9, pp. 129692-129705 2021. [19] a. janabi and b. wang, “switched-capacitor voltage boost converter for electric and hybrid electric vehicle drives,” ieee trans. on power electron., vol. 35, no. 6, pp. 5615-5624, june, 2020. [20] m. maalandish, s. h. hosseini, and t. jalilzadeh, “high step-up dc / dc converter using switchcapacitor techniques and lower losses for renewable energy applications,” iet power electronics, 11, pp. 1718–1729, 2018. https://doi.org/10.1109/access.2021.3111546 https://doi.org/10.1109/access.2021.3111546 https://doi.org/10.1109/access.2021.3111546 https://doi.org/10.1109/access.2021.3111546 https://doi.org/10.1109/tpel.2019.2949574 https://doi.org/10.1109/tpel.2019.2949574 https://doi.org/10.1109/tpel.2019.2949574 https://doi.org/10.1109/tpel.2019.2949574 https://doi.org/10.1049/iet-pel.2017.0752 https://doi.org/10.1049/iet-pel.2017.0752 https://doi.org/10.1049/iet-pel.2017.0752 https://doi.org/10.1049/iet-pel.2017.0752 introduction ii. materials and methods iii. results and discussions iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.60-71 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: r. nurdiansyah et al., “state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 1, pp. 60-71, july 2022. state of charge estimation of ultracapacitor based on equivalent circuit model using adaptive neuro-fuzzy inference system rizal nurdiansyah a, *, novie ayub windarko a, renny rakhmawati a, muhammad abdul haq b a electrical engineering department, politeknik elektronika negeri surabaya jl. raya its, surabaya, 60111, indonesia b department of electrical engineering and computer science, tokyo metropolitan university 1-1 minami-osawa, hachioji-shi, tokyo, 192-0397, japan received 31 may 2022; 1st revision 23 june 2022; 2nd revision 28 june 2022; accepted 29 june 2022; published online 29 july 2022 abstract ultracapacitors have been attracting interest to apply as energy storage devices with advantages of fast charging capability, high power density, and long lifecycle. as a storage device, accurate monitoring is required to ensure and operate safely during the charge/discharge process. therefore, high accuracy estimation of the state of charge (soc) is needed to keep the ultracapacitor working properly. this paper proposed soc estimation using the adaptive neuro-fuzzy inference system (anfis). the anfis is tested by comparing it to true soc based on an equivalent circuit model. to find the best method, the anfis is modified and tested with various membership functions of triangular, trapezoidal, and gaussian. the results show that triangular membership is the best method due to its high accuracy. an experimental test is also conducted to verify simulation results. as an overall result, the triangular membership shows the best estimation. simulation results show soc estimation mean absolute percentage error (mape) is 0.70 % for charging and 0.83 % for discharging. furthermore, experimental results show that mape of soc estimation is 0.76 % for random current. the results of simulations and experimental tests show that anfis with a triangular membership function has the most reliable ability with a minimum error value in estimating the state of charge on the ultracapacitor even under conditions of indeterminate random current. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: ultracapacitors; state of charge; adaptive neuro-fuzzy inference system; energy storage devices; equivalent circuit model. i. introduction ultracapacitors (ucs), also known as supercapacitors (scs) or electric double-layer capacitors (edlc), are now increasingly being used in electrical applications as energy storage devices. an ultracapacitor is a type of electric double-layer capacitor with a broad operating temperature range, low internal resistance, excellent durability, high power density, and high discharge capability to supply peak power requirements [1][2]. the use of ultracapacitors as energy storage devices is currently being increasingly used in electrical applications such as hybrid energy storage systems (hess), electric vehicles (evs), powertrains, and several other electrical applications [3][4][5]. the limitations of batteries in electric vehicles are their limited life cycle, low discharge rates, and special techniques needed to extend their life [6][7]. the latest solution to overcome this problem is to use an ultracapacitor as an additional power source for the main propulsion of electric vehicles and as a source of electrical energy in regenerative braking, which requires a short time [8]. ultracapacitor has fast charging capability with a charging current of up to tens of amperes and high discharge capability with a maximum discharge current of up to hundreds of amperes in one cycle [9]. fast charging capability is supported by the discovery of new materials with nanostructures, making the ultracapacitor has a larger capacitance even though its energy density is * corresponding author. tel: +62 858 5150 3369 e-mail address: nurdiansyahrizal@pe.student.pens.ac.id https://dx.doi.org/10.14203/j.mev.2022.v13.60-71 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.60-71 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.60-71&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:nurdiansyahrizal@pe.student.pens.ac.id r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 61 not greater than that of a lithium-ion battery [10]. ultracapacitors can be used in extreme temperatures because they have a wide operating temperature range and are supported by long cycle life, giving them an advantage over other energy storage devices [11]. technological developments increasingly encourage ultracapacitor, which has many advantages as an energy storage device to replace batteries [12]. in their implementation, some utilize ultracapacitor-battery hybrids to get optimal performance from both energy storage devices [13]. it is also possible to use an ultracapacitor as the primary energy storage device in electric vehicles, for example, electric scooters and buses [14]. fast charging capabilities make ultracapacitor a breakthrough in battery replacement technology [15]. the power supply for driving electric vehicles with high traction encourages using ultracapacitors with the advantages of high-power density and super-fast charging [16]. the high efficiency of the ultracapacitor is due to the low resistance of the constituent material supported by a high-power density, which makes it capable of high current discharge and low power dissipation [17]. the ultracapacitor's life cycle is much longer than other energy storage devices. the level of security using ultracapacitor needs to be considered with soc monitoring [18]. the conventional method for determining the state of charge is the open-circuit voltage (ocv) method which requires a rest period to determine the original voltage on the ultracapacitor, so it is not possible to use it in practical applications. the weakness of the ocv method cannot be measured in an operating state because an effective measurement when the condition is the voltage at the terminals does not represent the open-circuit voltage in the energy storage [19]. the use of coulomb counting only uses current operating parameters without regard to the internal conditions of the ultracapacitor and requires measuring instruments with high accuracy to avoid periodic errors. the unscented kalman filter (ukf) application for soc estimation still requires ocvsoc mapping to obtain accurate information about soc, and complex modeling makes parameter identification more difficult [20]. the difference between ultracapacitors and other energy storage devices is the ability to have a deeper discharge depth to be used optimally [21]. accurate state of charge (soc) monitoring is one of the factors in maintaining the safety of ultracapacitor performance to avoid overcharge or over-discharge conditions that cause dangerous conditions when used. ultracapacitor modeling is needed to determine its characteristics and electrical behavior so that it has high accuracy in determining the state of charge. the kalman filter method uses a more complex equation to get the state of charge value. based on experiments, estimates with the kalman filter have an error reading of about 5 % [22]. several models analyze the original characteristics of ultracapacitors, including classical equivalent circuit models, dynamic models, and transmission models [23][24]. the modeling that represents the characteristics of the ultracapacitor is a combination of series resistors and capacitors with the addition of parallel resistors as self-discharge modeling [25][26]. this paper proposes modeling with a combination of resistor and capacitor components as the relevant model and is referred to as the equivalent circuit model (ecm). the proper modeling will get the process of monitoring the state of charge (soc) on the ultracapacitor. by modeling the equivalent circuit models, which are simple and relevant, they are chosen because they can model the characteristics of the ultracapacitor with high accuracy [27]. this paper proposes a soc estimation method using the adaptive neuro-fuzzy inference system (anfis) algorithm from various models with their respective levels of complexity. artificial neural networks can form models in patterns such as neural networks obtained through learning experimental data to form a learning set as a system representation with a minimal error value by calculating the mean square error [28]. the learning stage of the artificial neural network is proven to have high accuracy and is relevant to be applied in various advanced research in the presence of appropriate data for the actual condition of the system [29]. the soc estimation method, which is performed by predicting the neural network algorithm and in collaboration with the reasoning owned by the fuzzy inference system, has a high level of accuracy [30][31]. the learning and training processes make anfis one of the best methods for estimating the soc ultracapacitor, which has dynamic behavior [32]. the experiment in this paper uses the equivalent circuit model (ecm) as the ultracapacitor characteristic modeling, while the anfis method is used as the soc estimation method. in addition, direct testing will be carried out on the hardware with constant current charging and discharging with a load in the form of a dc electronic load to obtain validation of the actual condition of the ultracapacitor. the results obtained will be compared between theoretical calculations with an equivalent circuit model, soc estimation using the anfis, and experimental data conducted in the laboratory. ii. materials and methods a. ultracapacitor modeling a series resistor and capasitor (rc) circuit is the simplest form of modeling the equivalent circuit model applied to an ultracapacitor. this model consists of a resistor representing the internal resistance and a capacitor indicating the charge capacity during charging and discharging of the ultracapacitor. figure 1 shows the simple modeling of an ultracapacitor with an equivalent circuit model. based on the ultracapacitor equivalent circuit's modeling, the following equations (1) and (2) are obtained based on kirchhoff's voltage law. 𝑉𝑡 is the terminal voltage obtained by measuring the voltage, 𝑣𝑐 is the authentic voltage of the ultracapacitor, 𝑖 is r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 62 the current in charge and discharge conditions, and 𝑅𝑠 is the equivalent series resistance of the ultracapacitor. 𝑉𝑡 = 𝑣𝑐 + 𝑖 ∙ 𝑅𝑠 (1) 𝑣𝑐 = 𝑉𝑡 − 𝑖 ∙ 𝑅𝑠 (2) ultracapacitor modeling primarily aims to simulate the characteristics under charge and discharge conditions. the change in terminal voltage during the ultracapacitor's service life indicates the charging and discharging process. the advantages of using ultracapacitors as energy storage devices are their ability to store energy long-term and high output power. in addition to the ultracapacitor operating conditions, the terminal voltage can slowly decrease due to self-discharge. self-discharge is caused by two conditions: ion diffusion and leakage current. this paper uses five ultracapacitor units in series for a higher nominal voltage with a lower capacitance. table 1 shows the data of the ultracapacitors used in this research. table 1 mentions the datasheet as an initial reference for the internal parameters of the ultracapacitor in the soc estimation on the simulink. in the advanced stage, this data will be validated through testing by researchers to determine the actual value of the internal parameters so that the soc estimate follows the actual conditions to be applied to simulink and the designed ultracapacitor hardware. the parameter values of the ultracapacitor components used in this paper are based on the samwha ultracapacitor datasheet. the following equation can validate parameter values based on the tests performed. the following equation can be used to determine the equivalent parallel resistance (𝑅𝑝) value. 𝐶 is the capacitance of ultracapacitors, 𝑉1 is the initial voltage, and 𝑉2 is the final voltage after charging. 𝑅𝑝 = −10800 𝑙𝑙 (𝑉2/𝑉1) 𝐶 (3) in this model, the aim is to find out the value of the ultracapacitor parameters that are not listed in the datasheet in this paper, namely the equivalent parallel resistance, which has been described in equation (3), and to validate the actual value of equivalent series resistance and capacitance. to determine the value of equivalent series resistance, equation (4) can be used, where ∆𝑉 is the change in voltage from the charging state to the open-circuit voltage and ∆𝐼 is the current value used in the testing process. 𝑅𝑠 = ∆𝑉 ∆𝐼 (4) then, the stored charge approximation method determines the capacitance ( 𝐶 ), as shown in equation (5). the ∆𝑉 value is the subtraction between 𝑉1 and 𝑉2 . 𝑉1 is a voltage of 0.8 of the nominal voltage of the ultracapacitor. meanwhile, 𝑉2 is a voltage of 0.4 of the nominal voltage of the ultracapacitor. the value of ∆𝑄 calculates the current integral during the testing process, where 𝑡1 is the discharge time to reach 𝑉1 and 𝑡2 is the discharge time to reach 𝑉2. 𝐶 = ∆𝑄 ∆𝑉 = ∫ 𝐼(𝑡)𝑑𝑡 𝑡2 𝑡1 (𝑉1−𝑉2) (5) b. state of charge estimation the state of charge is the ratio between an energy storage device's total usable energy capacity. this research is the ratio of the available energy capacity to the total charge in the ultracapacitor. state of charge represents the available energy and is generally expressed as a percentage in 0 to 1 or 0 to 100 %, with 100 % indicating the ultracapacitor is complete and 0 % is empty. the soc is an important parameter that must be known in using energy storage in addition to the voltage, current, capacity, and energy value. state of charge monitoring is necessary to maintain the ultracapacitor's lifetime by avoiding the risk of overcharging and overdischarging, which can affect the structural components of the ultracapacitor. at a more advanced stage, the determination of the soc can be used to control energy use. the accuracy level of soc estimation on the level of measurement accuracy and the suitability of the modeling to get an estimate that follows the actual conditions of the ultracapacitor. based on the equivalent circuit model table 1. ultracapacitor datasheet parameter value unit rated voltage 2.7 volt capacitance 500 farad cycle life 500000 cycle lifetime 10 year esr 3.1 mω maximum continuous current 25 ampere maximum peak current 264.7 ampere specific energy 5.59 wh/kg mass 89 grams operating temperature -40° to 65° celcius (a) (b) figure 1. (a) ultracapacitor library in matlab; (b) proposed ultracapacitor modeling r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 63 modeling, the formula to determine the soc on the ultracapacitor can be used with the following formula. 𝑆𝑆𝐶 % = � 𝑣𝑐 𝑣𝑐 𝑚𝑚𝑚 � × 100 (6) in equation (6), the value of 𝑣𝑐 is the ultracapacitor voltage obtained from the modeling results using an equivalent circuit model. for 𝑣𝑐 𝑚𝑚𝑚 is the value of 𝑣𝑐 at the maximum point in the charging process. the following summary in table 2 compares the methods used to estimate soc on ultracapacitors, along with their advantages and disadvantages. the table describes each method used for estimating the soc ultracapacitor and its ability to get estimation results that follow actual conditions, which are described as advantages and an explanation of the disadvantages of the methods used in the paper in actual application. c. adaptive neuro-fuzzy inference system (anfis) the research presented in this paper used the anfis to estimate the soc of ultracapacitor. the advantages possessed by artificial neural networks and fuzzy inference systems are collaborating to form anfis. with the ability to learn through data learning and fuzzy inference system reasoning, anfis is considered to work optimally to estimate the soc on the ultracapacitor. the anfis architecture has five layers with different special functions to form a pattern based on the training results. figure 2 shows that each layer has its function, which will be estimated using the anfis algorithm through detailed calculations to get a pattern that fits the model [33]. anfis is an advanced application of a fuzzy inference system with neural network architecture using takagisugeno as a learning process and determining the desired form of membership function. the anfis architecture consists of five layers with different special functions in each layer, making anfis performance with more complex and detailed processing. there are two rules for processing anfis with if-then rules as in equations (7) and (8). rule 1: if 𝑥 is 𝐴1 and 𝑦 is 𝐵1 then 𝑓1 = 𝑝1𝑥 + 𝑞1𝑦 + 𝑟1 (7) rule 2: if 𝑥 is 𝐴2 and 𝑦 is 𝐵2 then 𝑓2 = 𝑝2𝑥 + 𝑞2𝑦 + 𝑟2 (8) 𝐴1, 𝐴2, 𝐵1, and 𝐵2 are the premise parameters of the input membership functions 𝑥 and 𝑦, while 𝑝1, 𝑞1, 𝑟1, 𝑝2, 𝑞2, and 𝑟2 are linear consequent parameters of the takagi-sugeno fuzzy inference system. in designing anfis, it is necessary to pay attention to two rules in equations (7) and (8), clustering rules for data learning so that data processing at each layer follows the training data formed. in addition, it is necessary to pay attention to several important aspects, namely the type of membership function, the number of membership functions, error tolerance, and the number of epochs in the training process. the following is the workflow of the five layers in anfis. 1) layer 1 the fuzzification layer at node 𝑖 for 𝜇𝐴 and 𝜇𝐵 is shown in equations (9) and (10). each neuron is adaptive to the parameters to generate a membership function. at input, 𝑥 will form 𝜇𝐴𝑖, and input 𝑦 will form 𝜇𝐵𝑖 with 𝑖 =1,2 where 1 and 2 are two conditions resulting from clustering figure 2. anfis architecture [33] table 2. advantages and disadvantages of soc methods methods advantage disadvantage open-circuit voltage [1] simple and easy ultracapacitors need long times of rest to achieve voltage stability, causing difficulties in measurements. coulomb counting [1] simple and easy inaccurate current measurement will cause soc estimation error, and the error will increase with long-term accumulation. extended kalman filter [2] high accuracy despite external interference this method cannot be applied directly to estimate the states of a nonlinear system. open-circuit voltage – ukf [20] high accuracy requires ultracapacitor modeling, ocv, and ukf equations to get accurate results. kalman filter [22] high accuracy estimation errors must be recalculated to get convergent results. r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 64 membership function fuzzy logic reasoning to determine membership function. 𝑆𝑖 1 = 𝜇𝐴𝑖(𝑥) , 𝑖 = 1,2 (9) 𝑆𝑖 1 = 𝜇𝐵𝑖(𝑦) , 𝑖 = 1,2 (10) 2) layer 2 the fixed node layer 𝑤𝑖 produces output in the form of multiplication of all incoming signals by the node, representing the activation of the fuzzy rule. equation (11) shows the multiplication of 𝑤𝑖 using 𝜇𝐴𝑖 and 𝜇𝐵𝑖 with 𝑖 for conditions 1 and 2, which have been formed in the previous layer. 𝑆𝑖 2 = 𝑤𝑖 = 𝜇𝐴𝑖(𝑥) ∙ 𝜇𝐵𝑖(𝑦), 𝑖 = 1,2 (11) 3) layer 3 the nonadaptive normalization layer performs an activation function. 𝑤𝚤��� is a normalization of the fuzzy rule activation form with the value of 𝑤𝑖 divided by the total values of 𝑤1 and 𝑤2. determination of the value at layer 3 is shown in equation (12). 𝑆𝑖 3 = 𝑤𝚤��� = 𝑤𝑖 𝑤1+𝑤2 , 𝑖 = 1,2 (12) 4) layer 4 the adaptive defuzzification layer for 𝑤𝚤��� is multiplied by 𝑝𝑖 , 𝑞𝑖 , and 𝑟𝑖 . 𝑤𝚤���𝑓𝑖 is useful for denormalizing the values obtained at layer 3. to get the parameter values for the coefficients of 𝑝𝑖, 𝑞𝑖, and 𝑟𝑖 with 𝑖 for 1 and 2, using the recursive least square estimator (rlse) calculation. the following equation (13) is used to get the value on layer 4. 𝑆𝑖 4 = 𝑤𝚤���𝑓𝑖 = 𝑤𝚤��� ∙ [(𝑝𝑖 ∙ 𝑥) + (𝑞𝑖 ∙ 𝑦) + 𝑟𝑖)], 𝑖 = 1,2 (13) 5) layer 5 the single fuzzy node output layer is fixed to return all outputs by adding up all the inputs obtained from the fourth layer to determine the output layer using the function in equation (14). in the final calculation, layer 5 is obtained from the output layer 4 from the results of 𝑤𝚤���𝑓𝑖. the output from layer 5 is the estimated value of the ultracapacitor's authentic voltage, which will be used as the main parameter for soc estimation using the anfis algorithm. 𝑆𝑖 5 = ∑𝑤𝚤���𝑓𝑖 = ∑𝑤𝑖∙𝑓𝑖 ∑𝑓𝑖 , 𝑖 = 1,2 (14) iii. results and discussions in this experiment, the ultracapacitor energy storage system will be tested for charging using a dc power supply and discharging using a dc electronic load with a variable current to model the actual conditions in a non-linear load. figure 3 shows a research diagram for estimating soc. the equivalent circuit model in figure 1 and equation (6) in this system is used as true soc because it is an application of estimation with modeling to determine open-circuit voltage, which is commonly used for soc estimation in addition to coulomb counting. while the system is running, the measured voltage is the charging voltage. estimating the authentic voltage on the ultracapacitor obtained through modeling for estimation using the opencircuit voltage method is necessary. the authentic voltage on the ultracapacitor is the essential parameter to determine the state of charge. in simple terms, it is the authentic voltage of the ultracapacitor without the influence of equivalent series resistance. in this paper, five ultracapacitor units are used in series with the simulation on simulink matlab and hardware testing of measuring terminal voltage and current under charge and discharge conditions. the data required is the measurement of current and voltage at the terminal of the ultracapacitor energy storage system. the ultracapacitor is mathematically analyzed to adjust the electrical behavior and estimate the soc with a modeling system based on the equivalent circuit model. rc circuit in series with a parallel resistor as a selfdischarge model, as shown in figure 1. the anfis built will be used as an estimator to determine the soc value from the results of the supervised learning. the data obtained from the logging results will be processed simultaneously through modeling and the anfis estimator. performance testing will be performed using the root mean square error (rmse), mean square error (mse), mean absolute error figure 3. block diagram of the comparative analysis estimations soc r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 65 (mae), and mean absolute percentage error (mape) methods. from the results of characteristic testing with varying current patterns on charging and discharging conditions that have been carried out on ultracapacitor energy storage, training will be carried out on the anfis toolbox to build a fuzzy inference system. the required training data are voltage and current on charging and discharging conditions, with the target data being the authentic voltage on the ultracapacitor. the training process from the data obtained from testing the ultracapacitor characteristics is carried out on the matlab toolbox. figure 4 shows the training results using a hybrid method to get an algorithm following the original system. anfis training is used to form a fuzzy inference system pattern in the estimation process through the learning process. a hybrid method of artificial neural networks is used to form a network pattern that is appropriate and adaptive to system performance that varies with charging and discharging conditions. the flowchart of the anfis architecture is shown in figure 5. there are a series of processes, so the mechanism can work optimally according to the expected target. in the early stages, there is data sharing for training and testing, for training data using data from test results with the patterned current. in comparison, testing data using data from tests with random currents. based on the results of the anfis development, the average testing error of 6.9917e-9 indicates optimal learning outcomes and is following the desired target. a. simulation results from the training and data testing results to building anfis, performance testing is carried out on charging and discharging conditions in the simulation. current sources are randomly assigned to check the capability of the anfis as an estimator. (a) (b) figure 4. (a) training error with 100 epochs; (b) training data with authentic ultracapacitor voltage as target figure 5. flowchart of anfis architecture r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 66 in this simulation, the capacitance value of 100 farads and the equivalent series resistance of five ultracapacitor units of 15.5 mω is determined based on the reference obtained from the datasheet. figure 6 shows the charging and discharging process plot results in matlab. in the results, the variation of the membership function is conducted to determine the most optimal anfis performance for soc estimation (figure 7). the charging and discharging currents are made similar to the actual conditions in using non-linear loads to test the estimator's performance under conditions with drastic changes. over time, the soc will increase when charging and decrease when discharging. an ultracapacitor can handle this condition because it has a high discharge rate, a wide operating temperature, and a long lifecycle, making it safe to use in extreme conditions. table 3 shows the calculation of anfis performance testing using the rmse, mse, mae, and mape methods and the results of three different membership functions to determine the best model for the anfis estimator. based on the test, anfis has a high accuracy performance with mape calculation error values of 0.70 % in charging conditions and 0.83 % in discharging conditions for actual data compared to the estimated equivalent circuit modeling. the accuracy level is excellent if the prediction data is close to the actual data. the blue graph shows the true soc obtained using equation (6) from the estimation results. the true soc will compare the anfis estimator shown in the red graph for the triangular membership function, the yellow graph for the trapezoidal membership function, and the green graph is the gaussian membership function. table 4 shows the results of (a) (b) figure 6. (a) charging current and voltage; (b) discharging current and voltage r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 67 calculating the average error value in the soc estimation with previous research using the equivalent circuit model. the soc estimation research using anfis showed better results than the extended kalman filter method. b. experimental results this research uses a hardware design, as shown in figure 8, with the results presented using matlab to determine the performance of anfis for estimating the state of charge. observation of voltage and current on charging and discharging conditions using the yokogawa dl-3031 oscilloscope with programmable dc power supply, which functions as a charger, and dc electronic load as a load that works to represent use as energy storage in electric vehicles and other electrical applications. the charging uses constant current from programmable dc power supply mode by testing various current values to obtain varying charging conditions. ultracapacitor charging on real hardware was taken using a yokogawa dl-3031 oscilloscope with an increase in terminal voltage from the initial condition to full 13.5 volts and a variable constant current. from the characteristic test carried out with the results in figure 9, a calculation analysis can be carried out to determine the internal parameters of the ultracapacitor with equation (3) to determine the value of equivalent parallel resistance, equation (4) to determine the value of equivalent series (a) (b) figure 7. (a) estimations soc anfis with various mf on charging; (b) estimations soc anfis with various mf on discharge table 3. comparison estimation soc with various membership functions anfis membership function rmse mse mae mape charge discharge charge discharge charge discharge charge discharge triangular 0.0201377 0.0198281 0.0004055 0.0003932 0.0004027 0.0003965 0.7085133 0.8398471 trapezoidal 0.0201625 0.0197755 0.0004065 0.0003911 0.0004032 0.0003954 0.8328958 1.1025848 gaussian 0.0201474 0.0197879 0.0004059 0.0003916 0.0004029 0.0003957 0.7569106 1.0405872 table 4. comparison with previous research methods average error charge discharge ecm-ekf [2][22] <5.00 % <5.00 % ecm-anfis 0.99 % 0.92 % r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 68 resistance, and equation (5) to determine the value of capacitance. based on the characteristic test data shown in table 5 with the variation of the current source, it is known that the average value of equivalent series resistance (𝑅𝑠) is 0.10828 ω, equivalent parallel resistance (𝑅𝑝) 26.006 ω, and capacitance (𝐶) 80.748 farads. changes in the capacitance value from its (a) (b) figure 8. (a) experimental setup; (b) ultracapacitor energy storage system (a) (b) figure 9. ultracapacitor characteristic testing (a) 5a, 10 a, and 15 a testing; (b) 15 a, 20 a, and 25 a testing r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 69 original condition can be caused by being degraded due to use. meanwhile, the value of 𝑅𝑠 can is caused by the connecting conductor on each ultracapacitor. after testing the characteristics and getting actual parameters on the hardware, testing is carried out to determine the success of the estimation process. current sources with varying random values are used for the charging process to determine the anfis capability built to accurately estimate the soc value. figure 10 is a charging process with a random current, making the voltage increase in the ultracapacitor non-linear. therefore, anfis can be relied on to handle these conditions. figure 11 shows that the estimation graph using anfis with three different membership functions has results that coincide with true soc conditions. however, out of the three anfis membership functions used, the triangular membership function has the most superior performance, with the lowest mape at 0.76 %. in figure 12, the following data is presented for the calculation of rmse, mse, mae, and mape from the comparison between the true soc value and the estimated soc using various anfis membership functions. based on hardware experiments, the results of the error calculation using the rmse, mse, mae, and mape methods are shown to determine the performance of anfis in estimating the state of table 5. ultracapacitor parameter value from characteristic test results charging current 𝑹𝒔 𝑹𝒑 𝑪 5 a 0.1266 30.04 80.91 10 a 0.1147 25.11 81.35 15 a 0.1066 24.15 80.19 20 a 0.0970 25.15 81.29 25 a 0.0965 25.58 80 figure 10. charging current (top) and voltage (bottom) figure 11. estimations of soc anfis with various mf r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 70 charge on the ultracapacitor. the chart above is the result of a comparison of the estimation results by anfis with three different memberships, namely triangular, trapezoidal, and gaussian, to determine the most efficient form of membership function in the estimation process. the blue chart represents the performance of the triangular membership function, the orange chart represents the performance of the trapezoidal membership function, and the gray chart represents the performance of the gaussian membership function from the error calculation results using the four relevant methods used as a reference to determine learning performance. iv. conclusion based on the research results to estimate soc, the equivalent circuit model is a relevant circuit for ultracapacitor modeling because it has a simple and accurate model. it is also supported by anfis intelligence as an estimator capable of estimating the soc value with high accuracy. anfis with triangular membership function as a method for predicting soc estimation on ultracapacitors works optimally and has high accuracy with mape calculation of 0.70 % for charging while 0.83 % for discharging compared to true soc. while in the hardware experiment, the results of the soc estimation with the triangular membership function are small at 0.76 %. it is hoped that soc research can develop with simplification and better performance in the future. ultracapacitors as energy storage devices, both hybrid and primary, can be developed and applied to electric vehicles and other electronic applications because of their excellent performance. acknowledgment the authors are grateful to politeknik elektronika negeri surabaya and renewable energy laboratory for the permission to use the ultracapacitor for this research and to publish this paper. we would also like to thank those who have helped and supported us in preparing this manuscript. declarations author contribution rizal nurdiansyah: writing original draft, writing review & editing, conceptualization, software, hardware, formal analysis, investigation, visualization, validation. novie ayub windarko: writing original draft, formal analysis, conceptualization, investigation, visualization, validation, data curation, resources, supervision. renny rakhmawati: formal analysis, conceptualization, investigation, supervision. muhammad abdul haq: formal analysis, supervision. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] c. liu, q. li, and k. wang, “state-of-charge estimation and remaining useful life prediction of supercapacitors,” renew. sustain. energy rev., vol. 150, p. 111408, oct. 2021. [2] a. afandi, b. sumantri, and n. a. windarko, “estimation state of charge (soc) of ultracapacitor based on classical equivalent circuit using extended kalman filter,” in 2020 international electronics symposium (ies), surabaya, indonesia, sep. 2020, pp. 31–36. [3] p. fornaro, p. puleston, and p. battaiotto, “on-line parameter estimation of a lithium-ion battery/supercapacitor storage system using filtering sliding mode differentiators,” j. energy storage, vol. 32, p. 101889, dec. 2020. [4] k. alobeidli and v. khadkikar, “a new ultracapacitor state of charge control concept to enhance battery lifespan of dual storage electric vehicles,” ieee trans. veh. technol., vol. 67, no. 11, pp. 10470–10481, nov. 2018. [5] t. rout, a. chowdhury, m. k. maharana, and s. samal, “analysis of energy management system for photovoltaic figure 12. soc estimation error values with method calculations: rmse, mse, mae, and mape https://mev.lipi.go.id/ https://doi.org/10.1016/j.rser.2021.111408 https://doi.org/10.1016/j.rser.2021.111408 https://doi.org/10.1016/j.rser.2021.111408 https://doi.org/10.1109/ies50839.2020.9231736 https://doi.org/10.1109/ies50839.2020.9231736 https://doi.org/10.1109/ies50839.2020.9231736 https://doi.org/10.1109/ies50839.2020.9231736 https://doi.org/10.1109/ies50839.2020.9231736 https://doi.org/10.1016/j.est.2020.101889 https://doi.org/10.1016/j.est.2020.101889 https://doi.org/10.1016/j.est.2020.101889 https://doi.org/10.1016/j.est.2020.101889 https://doi.org/10.1109/tvt.2018.2871038 https://doi.org/10.1109/tvt.2018.2871038 https://doi.org/10.1109/tvt.2018.2871038 https://doi.org/10.1109/tvt.2018.2871038 https://doi.org/10.1109/icsesp.2018.8376737 https://doi.org/10.1109/icsesp.2018.8376737 r. nurdiansyah et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 60-71 71 system with battery and supercapacitor using fuzzy logic controller,” in 2018 technologies for smart-city energy security and power (icsesp), bhubaneswar, mar. 2018, pp. 1– 4. [6] a. amin, k. ismail, and a. hapid, “implementation of a lifepo4 battery charger for cell balancing application,” j. mechatron. electr. power veh. technol., vol. 9, no. 2, p. 81, dec. 2018. [7] b. traore, m. doumiati, c. morel, j.-c. olivier, and o. soumaoro, “energy management strategy based on a new adaptive filtering algorithm for battery-ultracapacitor electric vehicles,” in 2020 15th ieee conference on industrial electronics and applications (iciea), kristiansand, norway, nov. 2020, pp. 392–396. [8] a. r. al tahtawi and a. s. rohman, “simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose,” j. mechatron. electr. power veh. technol., vol. 7, no. 2, pp. 77–86, dec. 2016. [9] h. yang, “estimation of supercapacitor charge capacity bounds considering charge redistribution,” ieee trans. power electron., vol. 33, no. 8, pp. 6980–6993, aug. 2018. [10] q. zhu et al., “a new view of supercapacitors: integrated supercapacitors,” adv. energy mater., vol. 9, no. 36, p. 1901081, sep. 2019. [11] h. jiang, l. xu, j. li, z. hu, and m. ouyang, “energy management and component sizing for a fuel cell/battery/supercapacitor hybrid powertrain based on twodimensional optimization algorithms,” energy, vol. 177, pp. 386–396, jun. 2019. [12] i. jarraya, f. masmoudi, m. h. chabchoub, and h. trabelsi, “an online state of charge estimation for lithium-ion and supercapacitor in hybrid electric drive vehicle,” j. energy storage, vol. 26, p. 100946, dec. 2019. [13] s. hussain, m. u. ali, g.-s. park, s. h. nengroo, m. a. khan, and h.-j. kim, “a real-time bi-adaptive controller-based energy management system for battery–supercapacitor hybrid electric vehicles,” energies, vol. 12, no. 24, p. 4662, dec. 2019. [14] c-t. ma, “design and implementation of a hybrid real-time state of charge estimation scheme for battery energy storage systems,” processes, vol. 8, no. 1, p. 2, dec. 2019. [15] h. yang, “application of peukert’s law in supercapacitor discharge time prediction,” j. energy storage, vol. 22, pp. 98– 105, apr. 2019. [16] p. venugopal, “state-of-charge estimation methods for li-ion batteries in electric vehicles,” international journal of innovative technology and exploring engineering (ijitee), vol. 8, no. 7, p. 11, 2019. [17] poonam, k. sharma, a. arora, and s. k. tripathi, “review of supercapacitors: materials and devices,” j. energy storage, vol. 21, pp. 801–825, feb. 2019. [18] h. chaoui and h. gualous, “online lifetime estimation of supercapacitors,” ieee trans. power electron., vol. 32, no. 9, pp. 7199–7206, sep. 2017. [19] l. rozaqi, e. rijanto, and s. kanarachos, “comparison between rls-ga and rls-pso for li-ion battery soc and soh estimation: a simulation study,” j. mechatron. electr. power veh. technol., vol. 8, no. 1, pp. 40–49, jul. 2017. [20] p. saha, s. dey, and m. khanra, “accurate estimation of stateof-charge of supercapacitor under uncertain leakage and open circuit voltage map,” j. power sources, vol. 434, p. 226696, sep. 2019. [21] m. a. awadallah and b. venkatesh, “accuracy improvement of soc estimation in lithium-ion batteries,” j. energy storage, vol. 6, pp. 95–104, may 2016. [22] z. tao, g. shaoting, l. xin, and j. jing, “soc estimation scheme of super capacitor based on calman filter,” in 2016 ieee 11th conference on industrial electronics and applications (iciea), hefei, china, jun. 2016, pp. 918–921. [23] j. wang, l. zhang, j. mao, j. zhou, and d. xu, “fractional order equivalent circuit model and soc estimation of supercapacitors for use in hess,” ieee access, vol. 7, pp. 52565–52572, 2019. [24] j. i. hidalgo-reyes, j. f. gómez-aguilar, r. f. escobar-jiménez, v. m. alvarado-martínez, and m. g. lópez-lópez, “classical and fractional-order modeling of equivalent electrical circuits for supercapacitors and batteries, energy management strategies for hybrid systems and methods for the state of charge estimation: a state of the art review,” microelectron. j., vol. 85, pp. 109–128, mar. 2019. [25] l. zhang, x. hu, z. wang, f. sun, and d. g. dorrell, “a review of supercapacitor modeling, estimation, and applications: a control/management perspective,” renew. sustain. energy rev., vol. 81, pp. 1868–1878, jan. 2018. [26] m. r. djalal, h. setiadi, and a. imran, “frequency stability improvement of micro hydro power system using hybrid smes and ces based on cuckoo search algorithm,” j. mechatron. electr. power veh. technol., vol. 8, no. 2, pp. 76–84, dec. 2017. [27] m. e. şahin, f. blaabjerg, and a. sangwongwanich, “modelling of supercapacitors based on simplified equivalent circuit,” cpss trans. power electron. appl., vol. 6, no. 1, pp. 31–39, mar. 2021. [28] m. rif’an, f. yusivar, and b. kusumoputro, “sensorless-bldc motor speed control with ensemble kalman filter and neural network,” j. mechatron. electr. power veh. technol., vol. 10, no. 1, pp. 1–6, dec. 2019. [29] k. faqih, s. sujito, s. sendari, and f. s. aziz, “smart guided missile using accelerometer and gyroscope based on backpropagation neural network method for optimal control output feedback,” j. mechatron. electr. power veh. technol., vol. 11, no. 2, pp. 55–63, dec. 2020. [30] a. soualhi et al., “heath monitoring of capacitors and supercapacitors using the neo-fuzzy neural approach,” ieee trans. ind. inform., vol. 14, no. 1, pp. 24–34, jan. 2018. [31] a. fotouhi, d. j. auger, k. propp, and s. longo, “lithium–sulfur battery state-of-charge observability analysis and estimation,” ieee trans. power electron., vol. 33, no. 7, pp. 5847–5859, jul. 2018. [32] k. v. singh, h. o. bansal, and d. singh, “hardware-in-the-loop implementation of anfis based adaptive soc estimation of lithium-ion battery for hybrid vehicle applications,” j. energy storage, vol. 27, p. 101124, feb. 2020. [33] h. suryoatmojo, m. ridwan, d. c. riawan, e. setijadi, and r. mardiyanto, “hybrid particle swarm optimization and recursive least square estimation based anfis multioutput for bldc motor speed controller,” international journal of innovative computing, information and control (icic), vol. 15, no. 3, june 2019. https://doi.org/10.1109/icsesp.2018.8376737 https://doi.org/10.1109/icsesp.2018.8376737 https://doi.org/10.1109/icsesp.2018.8376737 https://doi.org/10.1109/icsesp.2018.8376737 https://doi.org/10.14203/j.mev.2018.v9.81-88 https://doi.org/10.14203/j.mev.2018.v9.81-88 https://doi.org/10.14203/j.mev.2018.v9.81-88 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.1109/iciea48937.2020.9248112 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.14203/j.mev.2016.v7.77-86 https://doi.org/10.1109/tpel.2017.2764423 https://doi.org/10.1109/tpel.2017.2764423 https://doi.org/10.1109/tpel.2017.2764423 https://doi.org/10.1002/aenm.201901081 https://doi.org/10.1002/aenm.201901081 https://doi.org/10.1002/aenm.201901081 https://doi.org/10.1016/j.energy.2019.04.110 https://doi.org/10.1016/j.energy.2019.04.110 https://doi.org/10.1016/j.energy.2019.04.110 https://doi.org/10.1016/j.energy.2019.04.110 https://doi.org/10.1016/j.energy.2019.04.110 https://doi.org/10.1016/j.est.2019.100946 https://doi.org/10.1016/j.est.2019.100946 https://doi.org/10.1016/j.est.2019.100946 https://doi.org/10.1016/j.est.2019.100946 https://doi.org/10.3390/en12244662 https://doi.org/10.3390/en12244662 https://doi.org/10.3390/en12244662 https://doi.org/10.3390/en12244662 https://doi.org/10.3390/pr8010002 https://doi.org/10.3390/pr8010002 https://doi.org/10.3390/pr8010002 https://doi.org/10.1016/j.est.2019.01.022 https://doi.org/10.1016/j.est.2019.01.022 https://doi.org/10.1016/j.est.2019.01.022 https://www.ijitee.org/wp-content/uploads/papers/v8i7/f3430048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i7/f3430048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i7/f3430048619.pdf https://www.ijitee.org/wp-content/uploads/papers/v8i7/f3430048619.pdf https://doi.org/10.1016/j.est.2019.01.010 https://doi.org/10.1016/j.est.2019.01.010 https://doi.org/10.1016/j.est.2019.01.010 https://doi.org/10.1109/tpel.2016.2629440 https://doi.org/10.1109/tpel.2016.2629440 https://doi.org/10.1109/tpel.2016.2629440 https://doi.org/10.14203/j.mev.2017.v8.40-49 https://doi.org/10.14203/j.mev.2017.v8.40-49 https://doi.org/10.14203/j.mev.2017.v8.40-49 https://doi.org/10.14203/j.mev.2017.v8.40-49 https://doi.org/10.1016/j.jpowsour.2019.226696 https://doi.org/10.1016/j.jpowsour.2019.226696 https://doi.org/10.1016/j.jpowsour.2019.226696 https://doi.org/10.1016/j.jpowsour.2019.226696 https://doi.org/10.1016/j.est.2016.03.003 https://doi.org/10.1016/j.est.2016.03.003 https://doi.org/10.1016/j.est.2016.03.003 https://doi.org/10.1109/iciea.2016.7603713 https://doi.org/10.1109/iciea.2016.7603713 https://doi.org/10.1109/iciea.2016.7603713 https://doi.org/10.1109/iciea.2016.7603713 https://doi.org/10.1109/access.2019.2912221 https://doi.org/10.1109/access.2019.2912221 https://doi.org/10.1109/access.2019.2912221 https://doi.org/10.1109/access.2019.2912221 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.mejo.2019.02.006 https://doi.org/10.1016/j.rser.2017.05.283 https://doi.org/10.1016/j.rser.2017.05.283 https://doi.org/10.1016/j.rser.2017.05.283 https://doi.org/10.1016/j.rser.2017.05.283 https://doi.org/10.14203/j.mev.2017.v8.76-84 https://doi.org/10.14203/j.mev.2017.v8.76-84 https://doi.org/10.14203/j.mev.2017.v8.76-84 https://doi.org/10.14203/j.mev.2017.v8.76-84 https://doi.org/10.24295/cpsstpea.2021.00003 https://doi.org/10.24295/cpsstpea.2021.00003 https://doi.org/10.24295/cpsstpea.2021.00003 https://doi.org/10.24295/cpsstpea.2021.00003 https://doi.org/10.14203/j.mev.2019.v10.1-6 https://doi.org/10.14203/j.mev.2019.v10.1-6 https://doi.org/10.14203/j.mev.2019.v10.1-6 https://doi.org/10.14203/j.mev.2019.v10.1-6 https://doi.org/10.14203/j.mev.2020.v11.55-63 https://doi.org/10.14203/j.mev.2020.v11.55-63 https://doi.org/10.14203/j.mev.2020.v11.55-63 https://doi.org/10.14203/j.mev.2020.v11.55-63 https://doi.org/10.14203/j.mev.2020.v11.55-63 https://doi.org/10.1109/tii.2017.2701823 https://doi.org/10.1109/tii.2017.2701823 https://doi.org/10.1109/tii.2017.2701823 https://doi.org/10.1109/tpel.2017.2740223 https://doi.org/10.1109/tpel.2017.2740223 https://doi.org/10.1109/tpel.2017.2740223 https://doi.org/10.1109/tpel.2017.2740223 https://doi.org/10.1016/j.est.2019.101124 https://doi.org/10.1016/j.est.2019.101124 https://doi.org/10.1016/j.est.2019.101124 https://doi.org/10.1016/j.est.2019.101124 https://doi.org/10.24507/ijicic.15.03.939 https://doi.org/10.24507/ijicic.15.03.939 https://doi.org/10.24507/ijicic.15.03.939 https://doi.org/10.24507/ijicic.15.03.939 https://doi.org/10.24507/ijicic.15.03.939 https://doi.org/10.24507/ijicic.15.03.939 introduction ii. materials and methods a. ultracapacitor modeling b. state of charge estimation c. adaptive neuro-fuzzy inference system (anfis) 1) layer 1 2) layer 2 3) layer 3 4) layer 4 5) layer 5 iii. results and discussions a. simulation results experimental results iv. conclusion acknowledgment declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.87-93 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: k. f. a. sukra et al., “impact of road load parameters on vehicle co2 emissions and fuel economy: a case study in indonesia,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 87-93, july. 2023. impact of road load parameters on vehicle co2 emissions and fuel economy: a case study in indonesia kurnia fajar adhi sukra a, *, heru priyanto a, dedy indriatmono b, muhamad agus wijayanto c, irfan yahya ikhsanudin c, yoga akbar ermansyah d a research center for transportation technology, national research and innovation agency, south tangerang, 15310, indonesia b research center for energy conversion and conservation, national research and innovation agency, south tangerang, 15310, indonesia. c directorate of laboratory management, national research and innovation agency, south tangerang, 15310, indonesia d faculty of transportation engineering and vehicle engineering, budapest university of technology and economics, budapest, 1111, hungary received 4 april 2023; 1st revision 5 june 2023; 2nd revision 14 june 2023; accepted 19 june 2023; published online 31 july 2023 abstract carbon dioxide (co2) contributes to the greenhouse effect and global warming. the indonesian government has introduced a reduction in vehicle taxes based on the number of co2 emissions, meaning that lower co2 emissions result in lower tax rates. to measure the co2 emissions, vehicle testing can be conducted on a chassis dynamometer using road load (r/l) parameters to assess the vehicle's loading during the test. the united nations economic commission for europe (un ece) regulation no. 101 (r101) provides predefined table values for testing, but vehicle manufacturers can also provide their own r/l values, known as actual r/l. in this study, the vehicle underwent two tests: one using the r/l values from the standard table r101 and another using the actual r/l values provided by the manufacturer through coast-down results. by employing the actual r/l values, co2 emissions can be reduced by up to 7.3 %. this reduction is achieved by lowering the vehicle's load by up to 17 % to enable optimal vehicle performance. additionally, there is a potential improvement in fuel economy of up to 7.9 % for vehicles. these findings can serve as a reference for establishing future standard testing procedures. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: road load (r/l); un ece r101; carbon dioxide emission; fuel economy. i. introduction global warming is a problem experienced by the whole world [1]. experts suggest that carbon dioxide (co2) is the leading cause of the recent occurrence of global warming [2][3]. as much as 25 % of the world's co2 emissions are generated from the transportation sector, resulting from the combustion of exhaust gases [3][4][5]. urban transport produces high co2 emissions in urban areas [6]. to overcome this condition, the indonesian government has enacted pp 73 of 2019, which is revised with pp 74 of 2021 concerning changes to government regulation number 73 of 2019 concerning taxable goods that are classified as a luxury in the form of motor vehicles that are subject to sales tax on luxury goods where the amount of tax for new vehicles is determined based on the co2 emissions produced [7][8]. with the enactment of this regulation, it is hoped that vehicle manufacturers, especially in indonesia, will compete to develop more environmentally friendly technology by reducing co2 emissions in vehicle exhaust gases. various studies have been carried out to be able to reduce co2 emissions from motor vehicles. modification of the exhaust line can be an option to lower these emissions. mishra et al. explained that using a chamber-shaped exhaust without holes can reduce co2 emissions by up to 50 % compared to using chamber types with holes or turbo types, * corresponding author. tel: +62-857-2409-9065 e-mail address: kurnia.fajar.adhi.sukra@brin.go.id https://dx.doi.org/10.14203/j.mev.2023.v14.87-93 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.87-93 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 88 either with holes or without holes [9]. zhang et al. also explained that the strategy to reduce co2 emissions could be done by converting the co2 into methanol using a thermal catalytic with an hydrogen (h2) obtained from the renewable energy process is a promising step in the future [10]. meanwhile, we can also apply hybrid technology vehicles to reduce co2 emissions on the engine side. by using this hybrid technology, the vehicle will operate more efficiently, reducing co2 emissions [11]. for vehicle development in indonesia, the laboratory for thermodynamics motor and propulsion technology under national research and innovation agency in indonesia is one of the government agencies mandated to conduct motor vehicle emission tests. since 2005 this lab has been testing motor vehicle emissions that will be traded in indonesia nationally. the vehicle was tested using a test cycle and run-on chassis dynamometer. this dynamometer simulated the vehicle's condition as if it were running on the road. the vehicle's loading adjusted to the vehicle or used the table predetermined by the euro standard in the united nations economic commission for europe (un ece) regulation no. 101 (r101). the loading parameter of this vehicle is called road load (r/l). r/l is a vehicle speed loading that accommodates the effects of rolling resistance, aerodynamic resistance, acceleration, and road slope level [12]. for test conditions, the slope level of the road can be assumed to be flat or 0. meanwhile, the other three parameters will affect the load of the driving resistance. kuhlwein [13] reported that there was a difference in the value of co2 emissions when using different r/l values. there was an increase in co2 emissions when using the actual r/l compared to the r/l data used for the approval type test. on average, there was an increase in co2 emissions of up to 7.2 % for type tests in europe and 1.8 % for type tests in the u.s. jaworski [14] reported that an increase in the energy consumption of the vehicle will increase the co2 emission and lower the fuel economy. there was an increase of 35 % in co2 emissions with an increase of 32 % in energy consumption. the purpose of this research is to compare the co2 emissions and fuel economy of vehicles in indonesia using the r/l data provided by vehicle manufacturers and the un ece r101 standard. the study aims to determine the impact of vehicle r/l on chassis dynamometer tests. these results can be used as a reference to determine the standard testing procedures that will be applied in the future. ii. materials and methods this study tested the co2 emissions of passenger vehicles below 3.5 tons. this test was carried out following the un ece r101 test method, in which the vehicle was tested on a chassis dynamometer and driven to follow the new european driving cycle (nedc) test cycle [15][16]. figure 1 is an nedc cycle that depicts the vehicle running in the actual condition of the vehicle while driving. the nedc cycle has two main parts: part i urban driving cycle (udc), or the driving cycle in the city, and part ii extra urban driving cycle (eud), or the driving cycle between cities. part i in nedc simulates a car driven in urban locations such as cities. part i consist of four times udc. there were three steps of car velocity: low, medium, and high. the maximum velocity of each section was 15 km/h, 30 km/h, and 50 km/h for low, medium, and high, respectively. part ii simulates a car driven at a higher velocity, such as a toll road or intercity highway, with a maximum velocity of 120 km/h. during the test, the chassis dynamometer will be responsible for loading according to the car's condition while on the road. this loading is a trait possessed for each vehicle and will differ in each car. even in similar models, it will be a difference, even though it is not too much. this loading value is based on the r/l formulation. figure 1. new european driving cycle (nedc) k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 89 there are two types of chassis dynamometers that can be used for testing: roller and hub type. the main difference between each type is the location of the motor for the dynamometer. the hub type is where the wheel directly connects to the motor without the tires. the roller type uses the tire of the vehicle and the motor connected with the drum roller. the hub type is not included in the current vehicle regulation [17]. by using the chassis dynamometer, we could measure the emission and work generated by the vehicle with an uncertainty factor. russo et al. specified two sources of uncertainty: vehicle experimental setup and experimental equipment. the vehicle experimental setup uncertainties are such as the driver and environmental conditions, and the initial condition of the vehicle. the experimental equipment examples are carry-over conditions, accuracy, and precision of the equipment [18]. lourenço et al. specified that rolling resistance was the most influential factor for fuel consumption measurement [19]. the r/l is the load the vehicle receives when drove on the road [20]. this parameter is formulated in equation (1). 𝐹𝑡𝑡𝑡𝑡𝑡 = 𝐹𝑟𝑟 + 𝐹𝑡𝑎𝑟𝑡 + 𝐹𝑡𝑎𝑎 + 𝐹𝑔𝑟𝑡𝑔 (1) where, 𝐹𝑡𝑡𝑡𝑡𝑡 is the total force as resistance in vehicles in n that consist of 4 components; 𝐹𝑟𝑟 is the resistance of rolling force; 𝐹𝑡𝑎𝑟𝑡 is aerodynamic force resistance; 𝐹𝑡𝑎𝑎 is the resistance of acceleration; and 𝐹𝑔𝑟𝑡𝑔 is the force from the slope of the road [12]. however, for testing on the chassis dynamometer, the road slope factor can be ignored, so using equation (2) 𝐹𝑡𝑟𝑡𝑎𝑡𝑡𝑡𝑎 = 𝐹0 + 𝐹1 × 𝑉 + 𝐹2 × 𝑉2 (2) the r/ls use three main parameters in the speed function: f0, f1, and f2. f0 is a coefficient parameter for a wheel rolling resistance, test lines, and drag of braking and bearings in n. f1 is a coefficient parameter for rolling resistance and pump losses in n/(km/h). f2 is a coefficient related to the aerodynamic force of the vehicle in n/(km/h)2. the summation of all component form a tractive force as resistance for the vehicle in n as 𝐹𝑡𝑟𝑡𝑎𝑡𝑡𝑡𝑎. v is vehicle speed in (km/h). the r/l for each vehicle was obtained by conducting a coast-down test. this test was carried out by driving the vehicle to maximum speed, and then the vehicle slides into the neutral transmission gear position so that gradually the vehicle slows down to a certain speed and then calculates the time needed from high speed to low speed. the test could be performed on tracks, roller chassis, and dynamometers. the speed and time of vehicles were recorded, and the time distance between the speeds was calculated to obtain the coast-down parameter. in addition, the weight of the test vehicle was used for the results of this test [13]. table 1 shows an example of the r/l chassis dynamometer setting for a car in each inertia. a car was tested twice using different r/ls, standard table and actual r/l, using r101 to get the emission and fuel economy. all cars were tested in chassis dynamometer at the laboratory of thermodynamics, engine, and propulsion in serpong, south tangerang. the chassis dynamometer provided by avl can withstand 4x4 or 4x2 cars below 3500 kg. it uses ama i60 for the gas analyzer and cvs for sampling the exhaust gas. there were 21 sample cars consisting of eight cars belonging to 910 kg inertia, four cars belonging to 1020 kg inertia, one car belonging to 1250 kg inertia, four cars belonging to 1360 kg inertia, two cars belonging to 1470 kg inertia, one car belonging to 1590 kg inertia, and one car belonging to 1700 kg inertia. the coefficient of r/l will be obtained from the coast-down test. r/l is the vehicle's deceleration force during the coast-down test. r/l is a combination of rolling resistance and aerodynamic force and is calculated at several speeds from the travel time and weight of the vehicle, including rotational inertia sourced from the wheels. this r/l value, when plotted on the graph between time and the traction force, will form a quadratic equation [13]. in addition to conducting a coast-down test, the r/l value can be used from the table provided in the un ece r101 standard. for each inertial vehicle, there is a coefficient r/l value, which is used as a reference on the dynamometer chassis. this value can be used when there is no data on the coastdown test results. the values in this table do not describe the actual condition of the vehicle when it is driven but can be used as a reference for official testing. from this r101 test, co2 emissions will be obtained produced by vehicles. the amount of co2 emissions is used for calculating vehicle fuel table 1. r/l reference value based on un ece r101 [21] car weight [kg] inertia [kg] standard table actual r/l example f0[n] f2 [n/(km/h)2] f0 [n] f1 [n/(km/h)] f2 [n/(km/h)2] 850 – 965 910 5.7 0.0385 96.12 0 0.0400 965 – 1080 1020 6.1 0.0412 156.59 -0.4819 0.0388 1190 – 1305 1250 6.8 0.0460 104.23 0 0.0334 1305 – 1420 1360 7.1 0.0481 145.00 0 0.0470 1420 – 1530 1470 7.4 0.0502 115.10 0.3436 0.0386 1530 – 1640 1590 7.6 0.0515 194.63 -1.0771 0.0485 1640 – 1760 1700 7.9 0.0536 207.56 -1.1337 0.0488 k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 90 economy during testing by the carbon balance method described in equation (3), 𝐹𝐹 = 100 � 0.1154 𝐷 �∙[(0.866∙𝐻𝐻)+(0.429∙𝐻𝐶)+(0.273∙𝐻𝐶2)] (3) where, fe for fuel economy in km/l; d for density of fuel at 15 °c in kg/m3; hc for the measured emission of hydrocarbon in g/km; co for the measured emission of carbon monoxide in g/km; co2 for measured emission of carbon dioxide in g/km [21]. this study conducted a comparative analysis of the carbon dioxide (co2) emissions and fuel efficiency of vehicles. to achieve this objective, r/l data obtained from test results were compared with r/l data in the un ece r101 standard table. the study identified notable variations in the test results that could be attributed to differences in the loading conditions experienced by the vehicles iii. results and discussions figure 2 shows the effect of using r/l using the actual to the standard table on co2 and fuel economy. using the actual r/l for each car lowers co2 emissions by 5 – 9 % and increases fuel economy between 5 – 11 % for various vehicles. on average from all vehicles, there is a decrease in co2 emissions and fuel economy by 7 %, as shown in figure 2. the highest decrease occurred in cars with inertial 1360 and the lowest decrease occurred in inertial 1470. this emission value is the total emission in the test cycle consisting of 2 parts. figure 2 also shows the trend of increasing the difference in co2 and fuel economy up to car inertia of 1360. the difference decreases in the inertia of 1470 kg, and then the difference increases again at 1700 kg with a slightly smaller difference at 1020 kg. this condition shows that the difference in r/l for large inertia for vehicles in indonesia has a smaller effect than inertial vehicles of 910 1360 kg. figure 3 shows the difference in vehicle co2 emissions in parts i and ii of the nedc test. in general, the biggest decrease occurred in part ii, the extra urban driving cycle, up to 17 %. while in the part i cycle or udc, there was the highest decrease up to 10 %. this is due to the difference in the value of the r/l, which is a function of the speed, where in part ii, the vehicle velocity is up to 120 km/h with an average speed of around 60 km/h. in part i, the vehicle only travels at a speed of 50 km/h, and the average speed of this cycle is 20 km/h. figure 3 also shows that urban cycles with low speeds and many accelerations result in a small r/l difference for inertia, especially above 1360 kg. therefore, the r/l factor for urban conditions can be considered small for inertia above 1360 kg because the cycle is mostly influenced by the kinetic and dynamic friction of the vehicle. this decrease in co2 emissions in vehicles is inseparable from the reduction in energy produced (a) (b) figure 2. differences between the actual to the r/l table in emissions: (a) and fuel economy; (b) for each vehicle (a) (b) figure 3. differences between the actual to the r/l table in co2 emissions: (a) and vehicle fuel economy; (b) in parts i and ii k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 91 during testing. the energy calculation uses equation (4), 𝑃 = 𝐹 ∙ 𝑉 (4) where, p is the power generated by the vehicle in w, f is the traction force of the r/l in n, and v is vehicle speed in m/s. f is the result of calculating the r/l for each vehicle, either using values from the table or the actual data of the vehicle. the result of this power calculation is made in a graph between power and time that shows the power that must be generated by the vehicle during the test at a certain speed, as shown in figure 4. in figure 4, the area under the power curve over time represents the amount of work generated by the vehicle during the test. the r/l data listed on the test standard is the worst possible condition for a vehicle for each inertia. so, the value of the r/l does not represent the vehicle's actual condition. for this reason, each manufacturer conducts coast-down testing in advance so that the vehicle can operate on a dynamometer chassis. figure 5 shows the difference in energy generated by the vehicle during the test. in general, there is a decrease in the power generated by the vehicle during continuous testing. on average, there is a decrease in the power of up to 17 %, leading to a reduction in co2 emissions from these vehicles. in some vehicles using actual coast-down data, it increases the power generated by the vehicle, especially in part i in the nedc testing stage, while in phase ii, most of the power decreased by the vehicle. compared to the power generated by the vehicle, it will be more in part ii. this causes part ii to have more influence on the emissions of the test results so that if there is a decrease in emissions in part ii, it will reduce emissions in total. the amount of energy produced by the vehicle will have a direct impact on the fuel economy of the vehicle. using the actual r/l, the power generated by the vehicle is not as large as when using the r/l from the standard table. the real condition of this vehicle will be able to be used by the actual data because it is a condition where the vehicle typically operates on the road. there was an increase in energy delivered from cars when using actual r/l than the official one. the energy increased by 15 % and 4.2 % in europe and the u.s., respectively. due to the increase in energy delivered from the engine, there was an increase in figure 4. work generated by the vehicle using r/l calculations figure 5. work differences between the actual to the r/l table k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 92 co2 emission of about 7 % and 1.8 % for europe and the u.s., respectively [13]. in indonesia, there was a decrease in energy produced by vehicles and co2 emissions of about 17 % and 7.3 %, respectively. the differences in these results are due to the differences in r/l. kuhlwein [13] used official r/l provided by the manufacturer for emission testing and realistic r/l. however, this study used actual r/l from the manufacturer and a standard table from un ece r101. jaworski et al. [14] experimented emission test using r101 with three different r/l, nedc table, resistance calculation, and worldwide harmonized light vehicle test procedure (wltp) alternative. there was an increase in co2 emission and energy generated by the vehicle using the nedc table and wltp alternative. there was a 35 % co2 emission increase from a 31 % increase in energy consumption. this condition is in line with our study that the higher energy generated by the vehicle will increase the emission of co2. iv. conclusion based on this study, it was found that the use of different r/l resulted in a different co2 emission under the r101 method. r/l represents the vehicle's condition when driven on the road, simulated by a dynamometer chassis system. the closer to the real conditions, the more vehicle will operate in actual condition. from the difference in the use of r/l, it was found that using actual r/l for r101 testing would reduce co2 emissions by an average of 7.3 %. in line with co2 emissions, fuel use will be more efficient, with an average of 7.9 %. the decrease in emissions may be due to a reduction in the energy produced by the vehicle when using actual r/l compared to using r/l from the table. the average energy decrease during the test was around 17 %, with the highest energy decrease in vehicles with an inertia of 1700 kg, which decreased to 27 %. the highest reduction in co2 emissions occurred in vehicles with an inertia of 1360 kg. based on this study, it is recommended to utilize the parameters specified in the euro standard r/l table for conducting the testing. this suggestion is grounded on the fact that employing these standard parameters represents the most unfavorable conditions that a vehicle may experience while being driven on the road. acknowledgements i wish to thank the laboratory for thermodynamics engine and propulsion technology team for their help in conducting tests and collecting all test data. declarations author contribution kfas is a main contributor who submits ideas, writes, and performs data analysis. hp checked the final review and supervised the experiment. yae review final article. di, maw, and iyi contribute to carrying out tests and processing test data. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] a. rehman, h. ma, m. ahmad, m. irfan, o. traore, and a. a. chandio, “towards environmental sustainability: devolving the influence of carbon dioxide emission to population growth, climate change, forestry, livestock and crops production in pakistan,” ecol. indic., vol. 125, p. 107460, 2021. [2] k. sohag, r. a. begum, s. m. syed abdullah, and m. jaafar, “dynamics of energy use, technological innovation, economic growth and trade openness in malaysia,” energy, vol. 90, pp. 1497–1507, 2015. [3] e. g. sari and m. sofwan, “carbon dioxide (co2) emissions due to motor vehicle movements in pekanbaru city, indonesia,” j. geosci. eng. environ. technol., vol. 6, no. 4, pp. 234–242, dec. 2021. [4] p. siskos and y. moysoglou, “assessing the impacts of setting co2 emission targets on truck manufacturers: a model implementation and application for the eu,” transp. res. part a policy pract., vol. 125, no. february 2019, pp. 123–138, 2019. [5] l. yang, y. wang, s. han, and y. liu, “urban transport carbon dioxide (co2) emissions by commuters in rapidly developing cities: the comparative study of beijing and xi’an in china,” transp. res. part d transp. environ., vol. 68, pp. 65–83, 2019, [6] s. m. labib, m. n. neema, z. rahaman, s. h. patwary, and s. h. shakil, “carbon dioxide emission and bio-capacity indexing for transportation activities: a methodological development in determining the sustainability of vehicular transportation systems,” j. environ. manage., vol. 223, no. may, pp. 57–73, 2018, [7] presiden republik indonesia, peraturan pemerintah republik indonesia nomor 73 tahun 2019 tentang barang kena pajak yang tergolong mewah berupa kendaraan bermotor yang dikenai pajak penjualan atas barang mewah, no. kementrian sekretariat negara republik indonesia. indonesia, 2019, pp. 135. [8] presiden republik indonesia, peraturan pemerintah republik indonesia nomor 74 tahun 2021 tentang perubahan atas peraturan pemerintah nomor 73 tahun 2019 tentang barang kena pajak yang tergolong mewah berupa kendaraan bermotor yang dikenai pajak penjualan atas barang mewah, no. kementrian sekretariat negara republik indonesia. indonesia, 2021, p. 12. [9] p. c. mishra, r. b. ishaq, and f. khoshnaw, “mitigation strategy of carbon dioxide emissions through multiple muffler design exchange and gasoline-methanol blend replacement,” j. clean. prod., vol. 286, p. 125460, 2021, [10] x. zhang, g. zhang, c. song, and x. guo, “catalytic conversion of carbon dioxide to methanol: current status and future perspective,” front. energy res., vol. 8, no. february, pp. 1–16, feb. 2021. [11] j. zheng, x. sun, l. jia, and y. zhou, “electric passenger vehicles sales and carbon dioxide emission reduction potential in china’s leading markets,” j. clean. prod., vol. 243, p. 118607, 2020. [12] j. son, j. ko, k. kim, c.-l. l. myung, s. park, and c. kim, “correlation analysis of road load fuel economy variations by energy difference for gasoline direct injection and dieselhttps://mev.lipi.go.id/ https://doi.org/10.1016/j.ecolind.2021.107460 https://doi.org/10.1016/j.ecolind.2021.107460 https://doi.org/10.1016/j.ecolind.2021.107460 https://doi.org/10.1016/j.ecolind.2021.107460 https://doi.org/10.1016/j.ecolind.2021.107460 https://doi.org/10.1016/j.energy.2015.06.101 https://doi.org/10.1016/j.energy.2015.06.101 https://doi.org/10.1016/j.energy.2015.06.101 https://doi.org/10.1016/j.energy.2015.06.101 https://doi.org/10.25299/jgeet.2021.6.4.7692 https://doi.org/10.25299/jgeet.2021.6.4.7692 https://doi.org/10.25299/jgeet.2021.6.4.7692 https://doi.org/10.25299/jgeet.2021.6.4.7692 https://doi.org/10.1016/j.tra.2019.05.010 https://doi.org/10.1016/j.tra.2019.05.010 https://doi.org/10.1016/j.tra.2019.05.010 https://doi.org/10.1016/j.tra.2019.05.010 https://doi.org/10.1016/j.trd.2017.04.026 https://doi.org/10.1016/j.trd.2017.04.026 https://doi.org/10.1016/j.trd.2017.04.026 https://doi.org/10.1016/j.trd.2017.04.026 https://doi.org/10.1016/j.jenvman.2018.06.010 https://doi.org/10.1016/j.jenvman.2018.06.010 https://doi.org/10.1016/j.jenvman.2018.06.010 https://doi.org/10.1016/j.jenvman.2018.06.010 https://doi.org/10.1016/j.jenvman.2018.06.010 https://doi.org/10.1016/j.jenvman.2018.06.010 https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://jdih.kemenkeu.go.id/fulltext/2019/73tahun2019pp.pdf https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://peraturan.bpk.go.id/home/details/171112/pp-no-74-tahun-2021 https://doi.org/10.1016/j.jclepro.2020.125460 https://doi.org/10.1016/j.jclepro.2020.125460 https://doi.org/10.1016/j.jclepro.2020.125460 https://doi.org/10.1016/j.jclepro.2020.125460 https://doi.org/10.3389/fenrg.2020.621119 https://doi.org/10.3389/fenrg.2020.621119 https://doi.org/10.3389/fenrg.2020.621119 https://doi.org/10.3389/fenrg.2020.621119 https://doi.org/10.1016/j.jclepro.2019.118607 https://doi.org/10.1016/j.jclepro.2019.118607 https://doi.org/10.1016/j.jclepro.2019.118607 https://doi.org/10.1016/j.jclepro.2019.118607 https://doi.org/10.1177/0954407019899516 https://doi.org/10.1177/0954407019899516 https://doi.org/10.1177/0954407019899516 k.f.a. sukra et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 87-93 93 powered vehicles,” proc. inst. mech. eng. part d j. automob. eng., vol. 234, no. 2–3, pp. 897–911, feb. 2020. [13] j. kühlwein, “the impact of official versus real-world road load on co2 emissions and fuel consumption of european passenger cars,” berlin, 2016. [online]. [14] a. jaworski et al., “evaluation of the effect of chassis dynamometer load setting on co2 emissions and energy demand of a full hybrid vehicle,” energies, vol. 15, no. 1, 2022, [15] “regulation no. 83 of the economic commission for europe of the united nations (un/ece) – uniform provisions concerning the approval of vehicles with regard to the emission of pollutants according to engine fuel requirements.” pp. 223– 495, 2006. [online]. [16] z. yang, b. deng, m. deng, and s. huang, “an overview of chassis dynamometer in the testing of vehicle emission,” matec web conf., vol. 175, pp. 2–5, 2018. [17] b. giechaskiel, f. forloni, m. otura, c. engström, and p. öberg, “experimental comparison of hub and roller‐type chassis dynamometers for vehicle exhaust emissions,” energies, vol. 15, no. 7, pp. 1–15, 2022. [18] m. di russo, k. stutenberg, and c. m. hall, “analysis of uncertainty impacts on emissions and fuel economy evaluation for chassis dynamometer testing,” ieee trans. veh. technol., vol. 72, no. 4, pp. 4236–4251, 2022. [19] m. a. de m. lourenço, j. j. eckert, f. l. silva, m. h. r. miranda, and l. c. de a. e. silva, “uncertainty analysis of vehicle fuel consumption in twin-roller chassis dynamometer experiments and simulation models,” mech. mach. theory, vol. 180, no. june 2022, p. 105126, 2023. [20] g. kadijk and n. ligterink, “road load determination of passenger cars,” 2012. [online]. [21] “regulation no 101 of the economic commission for europe of the united nations (un/ece) — uniform provisions concerning the approval of passenger cars equipped with an internal combustion engine with regard to the measurement of the emission of carbon diox.” pp. 89–139, 2004. [online]. https://doi.org/10.1177/0954407019899516 https://doi.org/10.1177/0954407019899516 http://www.theicct.org/ http://www.theicct.org/ http://www.theicct.org/ https://doi.org/10.3390/en15010122 https://doi.org/10.3390/en15010122 https://doi.org/10.3390/en15010122 http://data.europa.eu/eli/reg/2006/83(2)/oj http://data.europa.eu/eli/reg/2006/83(2)/oj http://data.europa.eu/eli/reg/2006/83(2)/oj http://data.europa.eu/eli/reg/2006/83(2)/oj http://data.europa.eu/eli/reg/2006/83(2)/oj https://doi.org/10.1051/matecconf/201817502015 https://doi.org/10.1051/matecconf/201817502015 https://doi.org/10.1051/matecconf/201817502015 https://doi.org/10.3390/en15072402 https://doi.org/10.3390/en15072402 https://doi.org/10.3390/en15072402 https://doi.org/10.3390/en15072402 https://doi.org/10.1109/tvt.2022.3222650 https://doi.org/10.1109/tvt.2022.3222650 https://doi.org/10.1109/tvt.2022.3222650 https://doi.org/10.1109/tvt.2022.3222650 https://doi.org/10.1016/j.mechmachtheory.2022.105126 https://doi.org/10.1016/j.mechmachtheory.2022.105126 https://doi.org/10.1016/j.mechmachtheory.2022.105126 https://doi.org/10.1016/j.mechmachtheory.2022.105126 https://doi.org/10.1016/j.mechmachtheory.2022.105126 http://www.tno.nl/ http://www.tno.nl/ http://data.europa.eu/eli/reg/2004/101(2)/oj http://data.europa.eu/eli/reg/2004/101(2)/oj http://data.europa.eu/eli/reg/2004/101(2)/oj http://data.europa.eu/eli/reg/2004/101(2)/oj http://data.europa.eu/eli/reg/2004/101(2)/oj introduction ii. materials and methods iii. results and discussions iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.62-71 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: r. khomarudin et al., “quasi-dynamic hosting capacity in radial distribution feeder,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 62-71, july 2023. quasi-dynamic hosting capacity in radial distribution feeder riki khomarudin *, kevin marojahan banjar-nahor, nanang hariyanto school of electrical engineering & informatics, bandung institute of technology jalan ganesha 10, bandung, 40132, indonesia received 14 march 2023; revised 14 june 2023; accepted 3 july 2023; published online 31 july 2023 abstract the target of massive installation of renewable energy is the focus of this research. several industrial sectors continue to install photovoltaic rooftop to support green energy. one of the main objectives of this research is to see the maximum impact of installing a photovoltaic rooftop at 1 point of customer and spread capacity for each customer. this research uses a radial distribution network system that closely resembles the distribution network in indonesia, where the load profile considers the load characteristics of industrial, commercial, and residential loads. this study uses the line equation theorem method to calculate the voltage rises by considering two current measurement points: the current at the end and the current at the base. the obtained voltage rise is then accumulated to be summed up with the customer afterward. the results are obtained by considering three scenarios: 1) voltage limits, 2) voltage limits and line loading, and 3) voltage limits, thermal, and harmonics in accordance with regulations. the obtained results are closely aligned with the simulations performed on the hosting capacity software such as digsilent. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: photovoltaic rooftop; line equation theorem; hosting capacity. i. introduction the installation of renewable energy distributed generators continues to increase until 2025 by 23 % based on the 2023-2030 national electricity supply business plan (ruptl) [1]. this is to reduce the existence of a carbon tax of idr 30 per kilogram [2]. based on indonesian ministry of energy and mineral resources (esdm) regulation [3], kwh exports have been expanded from the previous limit at 65 % to 100 % of the power capacity that can be generated per customer. the increase in the allowed installation capacity of photovoltaic is an appreciation of the growing for users of clean industrial services with green energy. to find out the maximum limit capacity of customer installation without causing a violation, the hosting capacity approach theorem is used for this research. according to research [4][5], hosting capacity is a high penetration limit regarding new renewable energy (ebt) without causing a violation. some problems and limitations in the customer's operations include voltage below the limit, network losses, overload on transformers and feeders, protection failures, and harmonics exceeding grid code standard limits [6][7]. the update in this research is to calculate the hosting capacity at the limits of each customer. this method considers the measurement of the load current at the end customer and the load current at the first customer by the line equation theorem method [8]. furthermore, for the system to be implemented close to the real system, the results of each customer's hosting capacity are calculated and validated within 24 hours [9][10][11]. ii. materials and methods hosting capacity is a limiting curve for installing dg capacity that can still be accepted based on performance indication criteria on the system [12][13]. the concept and idea of contributing to this research are shown in figure 1, which explains the concept of dynamic hosting capacity by calculating the amount of capacity per 24 hours for each customer. in the spread of the capacity, both in a * corresponding author. tel: +62 857 5580 1852 e-mail address: riki.khomarudin@mail.ugm.ac.id https://dx.doi.org/10.14203/j.mev.2023.v14.62-71 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.62-71 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 63 maximum at one customer point and each customer as a maximum simultaneous capacity. the radial distribution system modeling closely represents the real network system, as shown in figure 2, which consists of five customers, with each customer having a different distance. this model also has different customer capacities. this model is used as a model close to the real distribution system in indonesia based on the type and capacity of customers. the network voltage system used in the simulation is 20 kv, following the standard medium voltage distribution network [14]. a. voltage increase calculation in the hosting capacity equation, equation (1) is used to calculate the amount of distributed generation (dg) capacity for each customer based on the voltage increase (∆v) with the line equation theorem approach. this voltage increase calculation considers the two measurement points, namely at the beginning current and at the end current of the customer's load [15]. equation (2) was used to calculate each node where the tangent line meets. equation (2) is calculated using the theorem of the derivative function, which then obtains equation (3) as the final derivative function. in equation (3), the value of the increase in the voltage difference due to pv injection on the customer bus is obtained. 𝑦1 − 𝑦2 = 𝑚(𝑥2 − 𝑥1) (1) 𝑑𝑦 = 𝐼𝑝 + 𝐼𝑢−𝐼𝑝 𝑑 𝑑 𝑑𝑥 (2) ∆𝑉 = 𝑍 𝑑 2 �𝐼𝑝 + 𝐼𝑢� (3) where y1, y2, x1, x2 are points between parts that adopt from the line equation theorem. y1, and y2 represent points on the vertical axis y, and x1, x2 represents points on the horizontal axis x. while m represents the gradient. dy is the derivative of equation (1) with to dx function. figure 3 is a sample from two customer measurement points. the modeling of several customers is shown in figure 4. the equation formula was given for the value of the total voltage increase based on equation (4), which is used based on the total number of subscribers to the voltage increase of each installed pv. ∆𝑉𝑡𝑡𝑡 = 𝑍1 ∫𝑦1 + 𝑍2 ∫𝑦2 + 𝑍3 ∫𝑦3 + 𝑍4 ∫𝑦4 + 𝑍5 ∫𝑦5 (4) where ∆𝑉 is the increase in voltage due to injection of the spread generator (volt), z is the network impedance value (ω), d is the total distance of the end customer to the substation (km), 𝐼𝑝 is base current (a), and 𝐼𝑢 is the end current (a). b. calculation of dynamic hosting capacity according to papers [11][16][17], using hosting capacity calculations based on kirchhoff voltage law (kvl) calculations can be applied to find voltage solutions on the point of common coupling (pcc). pcc is a connected point due to the installation of photovoltaic. by representing resistance and figure 1. dynamic hosting capacity concept figure 2. radial distribution system 20 kv figure 3. pv injected into the bus r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 64 reactance in terms of 𝑅𝑒𝑒 and 𝑋𝑒𝑒 , considering 𝑈𝑔𝑔𝑔𝑑∠00 or as a slack bus. it can be written in equation (5), 𝑃𝑔 𝑚𝑚𝑚,1 = ∑ 𝑉𝑛 𝑚𝑚𝑚,1(𝑉𝑛 𝑚𝑚𝑚,1−𝑉𝑔1) 𝑅𝑒𝑒+𝑋𝑒𝑒 tan (𝜑) ℎ=24 ℎ=1 (5) where 𝑃𝑔 𝑚𝑚𝑚,1 is the maximum capacity of the injected hosting capacity (kwp), 𝑉𝑛 𝑚𝑚𝑚,1 is the voltage on the slack bus from the grid (kv), 𝑉𝑔1 is the voltage rise due to dg injection (kv), 𝑅𝑓 is the conductor resistance/km (ohm), 𝑋𝑓 is the conductor reactance/km (ohm), and tan (𝜑) is the power factor value at pcc. c. short circuit contribution current calculation of short circuit current considers based on calculations in the digsilent software. this short circuit current is calculated based on the iec 61909 standard in 2021. research [18], the calculation of the short circuit contribution current is calculated based on equation (6), 1 − � 𝐼𝑝 𝐸𝑠 � ∗ 𝑍𝑍 (6) where, 𝐼𝑝 is the pickup relay current, 𝐸𝑠 is the value of the phase–neutral voltage from the source, and zb is the value of the branch impedance. d. harmonic contribution harmonics is one of the constraints in this research. this constraint is used to maintain maximum capacity limits that are still safe and reliable when customers install their respective rooftop solar capacity. moreover, the existence of harmonics, besides distorting the voltage and current waves, will cause heat to occur in equipment components such as transformers. the calculation of the harmonic limit of the total distortion demand is as in equation (7) [19][20], 𝑇𝑇𝑇𝑔 = �∑ 𝐼𝑛 2∞ 𝑛=2 𝐼𝐿 (7) 𝑇𝑇𝑇𝑔 𝑥 𝑖1 = 𝑇𝑇𝑇𝑔 𝑥 𝐼𝐿 (8) where 𝑇𝑇𝑇𝑔 is total demand distortion, 𝐼𝑛2 is nominal current (a), 𝐼𝐿 is current in each of the customers (a). to calculate the amounts of harmonics from the total harmonic distortion (thd), it is formulated in equation (8). e. flowchart of this research the research flowchart in figure 5 is a simulation of workflow steps to calculate the amount of voltage increase due to distributed generation (dg) injection. the capacity of each customer is calculated based on the voltage increase on the pcc bus. the maximum allowable voltage increase is the reference for the purpose of hosting capacity. the data used to calculate this voltage increase is based on the current on the customer's end and the current on the customer's base. f. profile characteristic the type of profile curve is presented in figure 6, which contains three types of loads. the data is taken with the average data for one year. the data presented is the average peak load time. the value presented is the expense on weekdays, namely on mondays. the load profile characteristic is displayed in figure 6. the data was obtained from the typical data of each customer load. the data was inputted into the load profile in software simulation. the characteristics of the photovoltaic rooftop profile used in this study are based on the measurement points on the indonesian solar map, which are presented in figure 7. at the point of measurement results, an approach is used to be input as a parameter for the characteristics of solar panels based on the load profile category, namely residential, industrial, and commercial. the data was taken on march 22, 2022. g. constraint 1) voltage the distribution voltage constraint in the standard distribution system is set based on the voltage level. in a distribution system with a voltage of 20 kv, the system voltage is maintained based on the grid code or network interconnection rules: 0.9 𝑜𝑜 18 𝑘𝑉 ≤ 𝑉𝑔𝑔𝑔𝑑 ≤ 1.05 𝑜𝑜 21 𝑘𝑉 [3]. figure 4. pv injected in each of the customers r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 65 figure 5. flowchart of the research figure 6. load profile characteristic figure 7. photovoltaic profile characteristic 0 0.5 1 1.5 2 2.5 3 ca pa ci ty ( pu ) time 24 hours residential industrial commercial 0 0.2 0.4 0.6 0.8 1 1.2 pr od uc tio n (p u) time 24 hours residential industrial commercial r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 66 2) thermal loading the thermal loading limit is based on the maximum integration standard of renewable energy, set to maintain line loading, and the temperature in the distribution feeder is maintained. it is necessary to limit the influence of the installation capacity that enters and is connected to the distribution network. based on the grid code [3], the value of the thermal loading limit 𝐿𝑖𝐿𝐿_𝐿𝑡𝑚𝑑𝑔𝑛𝑔 ≤ 40 % 3) harmonic harmonics is one aspect of electric power quality in distribution feeders. harmonics arise from nonlinear loads or power electronic components connected to the network. in this research, the harmonics aspect is limited due to the installation of photovoltaic capacity in the distribution system. based on network rules (grid code), total harmonic distortion (thd) ≤ 5 % [3]. 4) harmonic data simulation in modeling harmonics caused by solar photovoltaic injection, the pulse-6 harmonic model is used in this paper [21]. the harmonic frequency values are presented in table 1, which is the dummy data used in the injection of harmonics in the generator is the fundamental current harmonics for balanced and unbalanced. the 2-pulse bridge data is used because this type of harmonics for solar photovoltaic has a sequential order of harmonics starting from the 3rd order. the 2-pulse bride order used, as shown in table 2, has a maximum order of harmonics up to the 50th order. this research uses these data as content data for generator harmonic distortion. iii. results and discussions the time used in this calculation is 14.00, during peak load times of the day. because when the calculation is done, namely estimating the current on the end side customer and the current on the base side customer. the data used for calculations are based on the peak load current during overload conditions. a. scenario 1: voltage constraint the hosting capacity calculation in this scenario is determined by the voltage limit standard. this scenario uses grid code rules with a minimum voltage of 0.9 p.u. and a maximum voltage of 1.05 p.u., it is important to note that the case study used a distribution system close to the real system on a 20 kv distribution network in indonesia. 1) quasi-dynamic simulation in customer 1 the installed capacity of the first customer is 328.26 mwp. the quasi-dynamic simulation results, shown in figure 8, indicate that the highest voltage recorded is 1.05 p.u. at 14:15. furthermore, the peak voltage value observed on customer 1 at 14:00 is determined by the characteristic curve in photovoltaic 1. 2) quasi-dynamic simulation in customer 2 the maximum capacity for customer 2 is 118.38 mwp. the highest voltage value at the maximum point on the 2nd customer is 1.05 p.u at 10:00. installation of photovoltaic rooftop capacity for the 2nd customer is shown in figure 9, when the highest voltage profile curve on the 2nd customer where the pv was installed. 3) quasi-dynamic simulation in customer 3 the maximum installation capacity of photovoltaic rooftop for customers is calculated to obtain a maximum capacity of 75.038 mwp. at the voltage limit, the peak voltage value is still in the maximum range of 1.05 p.u at system voltage, as shown in figure 10. 4) quasi-dynamic simulation in customer 4 calculation of the capacity of the 4th customer taking into account the voltage limit; the result is 62.285 mwp. these results are simulated for 24 hours. the highest voltage results are shown in figure 11, which shows a maximum voltage of 1.049 p.u. table 1. load harmonic data harmonics order ia_h (%) ib_h (%) ic_h (%) 1 100 100 100 2 20 20 20 3 10 10 10 5 80 80 80 7 60 60 60 9 30 30 30 table 2. photovoltaic harmonic data harmonics order ia_h (%) ib_h (%) ic_h (%) 3 33.333 33.333 33.333 5 20.000 20.000 20.000 7 14.286 14.286 14.286 9 11.111 11.111 11.111 11 9.091 9.091 9.091 13 7.692 7.692 7.692 15 6.667 6.667 6.667 17 5.882 5.882 5.882 19 5.263 5.263 5.263 21 4.762 4.762 4.762 23 4.348 4.348 4.348 25 4.000 4.000 4.000 27 3.704 3.704 3.704 29 3.448 3.448 3.448 31 3.226 3.226 3.226 33 3.030 3.030 3.030 35 2.857 2.857 2.857 37 2.703 2.703 2.703 39 2.564 2.564 2.564 41 2.439 2.439 2.439 43 2.326 2.326 2.326 45 2.222 2.222 2.222 47 2.128 2.128 2.128 49 2.041 2.041 2.041 r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 67 figure 8. voltage profile in customer 1 figure 9. voltage profile in customer 2 figure 10. voltage profile in customer 3 r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 68 5) quasi-dynamic simulation in customer 5 calculations performed on the 5th customer obtained a maximum capacity of 38.535 mwp. in figure 12, the highest voltage value is 1.034 p.u. it is to be noted that the last customer does not experience any additional voltage increase (∆v) from other customers. as a result, the voltage value for the last customer has a different value from the results obtained from the simulation. 6) spread capacity in each customer the distribution of capacity in each customer is determined based on voltage considerations. equation (9) outlines the distribution calculation, where the spread of capacity is divided from each maximum point in each customer to the total photovoltaic capacity. 𝑃𝑉 𝑐𝑐𝑐𝑐𝑐𝑖𝑐𝑦 = 𝑀𝑚𝑚𝑔𝑚𝑢𝑚 1 𝑝𝑡𝑔𝑛𝑡 𝑡𝑡𝑡𝑚𝑡 𝑃𝑉 𝑐𝑚𝑝𝑚𝑐𝑔𝑡𝑐 𝑥 𝑚𝑐𝑥𝑖𝑚𝑚𝑚 𝑐𝑝 𝑐𝑐𝑐𝑐𝑐𝑖𝑐𝑦(9) the capacity of each customer is simultaneously simulated over a 24-hour period, as illustrated in figure 13. the spread of capacity in each node can be seen in table 3. the objective is to evenly allocate the total capacity among the customers. the capacity for each customer is calculated, and a single diagram modeling approach is employed to simulate the results. based on the calculated capacities, the assumed distribution is implemented, and the results are run in the software. table 3. spread photovoltaic capacity in each customer customer at node hc (mwp) digsilent hc (mwp) mathematics spread (mwp) 1 327.00 328.260 169.00 2 120.00 118.380 22.70 3 75.86 75.038 9.13 4 64.18 62.285 6.29 5 55.38 38.535 2.41 *hc = hosting capacity figure 11. voltage profile in customer 4 figure 12. voltage profile in customer 5 r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 69 b. scenario 2: voltage, thermal loading, harmonic, and protection this scenario considers the existence of renewable energy interconnection to the system based on regulations (grid code). the constraints determined are voltage, thermal loading, and harmonics. the calculation analysis takes into account the simulation results performed on the digsilent software. 1) the difference between calculation and simulation results the results obtained from calculations and comparisons in the software are presented in table 4. in the calculations using equation (9), the results are not close or have many differences to the end customer. it is because the end customer does not have added value (∆𝑉). the spread capacity of each customer, multiplication of the maximum number of 1 point of photovoltaic rooftop capacity divided by the total photovoltaic rooftop multiplied by the highest maximum capacity. table 4 also shows the spread of the capacity in each customer. 2) quasi-dynamic results for scenario 2 the results of the simulation are shown in figure 14. it can be seen for the highest voltage at industrial loads with a value of 1,003 p.u. meanwhile, at the lowest voltage, the industrial load is also with a voltage value of 0.994 p.u. this highest rise is based figure 13. quasi-dynamic in photovoltaic spread of customer figure 14. voltage profile in 24 hours table 4. spread photovoltaic capacity for each customer bus hc (mwp) digsilent hc (mwp) mathematics spread (mwp) 1 23.96 23.5010 9.5500 2 13.28 13.2780 5.3961 3 8.36 8.3678 3.4005 4 7.07 7.1793 2.9174 5 6.11 5.5049 2.2370 *hc = hosting capacity r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 70 on the highest load profile when the load characteristics are applied. the voltage values obtained are still in the range of standard pln (spln), where the range of tolerance of the voltage with a minimum drop of 10 % and a maximum increasing 5 % from the basic nominal voltage value. the results of the line loading values are shown in figure 15, indicating that the highest loading values occur on cable 1 at 39.556 %. on the other hand, the value for the lowest thermal loading can be found on cable 5, which a value of 1.369 %. this discrepancy can be attributed to the fact that customer-1 has the largest generation capacity, resulting in a large channel load. the obtained results were compared to the standard grid code, and it was determined that the values are still in the range of safe operation. therefore, it is suggested that the calculated capacity can be implemented in real cases. according to the interconnection rules for renewable energy generators (grid code) [3], the allowable tolerance limit for harmonics when the voltage at the connection point ≤ 66 kv is 5 %. figure 16 shows that the highest voltage distortion occurs at 0.04 s of 36,329 kv. in this case, the virtual voltage measurement point is installed on the bus for each customer. based on the obtained results, it is evident that the voltage is still within the safe range of harmonics. this is because the harmonics contained due to the injection of photovoltaics are still within the safe limits. furthermore, figure 16 also indicates the presence of a very few harmonic frequencies in 1 wavelength. figure 15. thermal line loading figure 16. voltage harmonic distortion r. khomarudin et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 62-71 71 iv. conclusion in the simulation, the results for voltage limits were obtained. it was found that the photovoltaic capacity with voltage limit, with quasi-dynamic simulation for each customer, still met the +5 % and -10 % standards. the highest voltage value in scenario 1 is 1.05 p.u. at customer 1, customer 2, and customer 3. in scenario 2, the highest voltage result is 1.003 p.u. and the lowest is 0.994 p.u. the highest network load results were 39.558 %, and the lowest was 1.369 %, while the harmonics level with a lineto-line voltage of 36.329 kv. both of these scenarios are still within the limits of network standards. declarations author contribution r. khomarudin, k.m. banjar-nahor, and n. hariyanto contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] pt. perusahaan listrik negara, “rencana usaha penyediaan tenaga listrik (ruptl) pt pln (persero) 2021-2030.,” pt perusahaan listrik negara, 2021. [2] president of republic of indonesia, undang-undang nomor 7 tahun 2021 tentang harmonisasi peraturan perpajakan, no. pemerintah pusat. jdih bpk ri, 2021, pp. 1–6. [3] kementrian energi dan sumber daya mineral, peraturan menteri eenergi dan sumber daya mineral republik indonesia nomor 20 tahun 2020 tentang aturan jaringan sistem tenaga listrik (grid code). kementerian energi dan sumber daya mineral, 2020, p. 1019. [4] s. m. ismael, s. h. e. abdel aleem, a. y. abdelaziz, and a. f. zobaa, “state-of-the-art of hosting capacity in modern power systems with distributed generation,” renew. energy, vol. 130, pp. 1002–1020, jan. 2019. [5] m. zain ul abideen, o. ellabban, and l. al-fagih, “a review of the tools and methods for distribution networks’ hosting capacity calculation,” energies, vol. 13, no. 11, p. 2758, jun. 2020. [6] k. d. shinde and p. b. mane, “investigation of effects of solar photovoltaic penetration in an ieee 13-bus radial low-voltage distribution feeder system,” in 2022 19th international conference on electrical engineering/electronics, computer, telecommunications and information technology (ecti-con), may 2022, pp. 1–5. [7] m. u. qureshi, a. kumar, s. grijalva, j. deboever, j. peppanen, and m. rylander, “fast hosting capacity analysis for thermal loading constraint using sensitivity-based decomposition method,” in 2020 52nd north american power symposium (naps), apr. 2021, pp. 1–5. [8] t. gonen, electric power distribution engineering. power and energy: crc press, 2015. [9] j. yuan, y. weng, and c.-w. tan, “determining maximum hosting capacity for pv systems in distribution grids,” int. j. electr. power energy syst., vol. 135, no. january 2021, p. 107342, feb. 2022. [10] m. u. qureshi, s. grijalva, and m. j. reno, “a rapid quasi-static time series method for evaluating current-related distributed pv impacts including feeder loading and line losses,” in 2019 ieee power & energy society general meeting (pesgm), aug. 2019, vol. 2019-augus, pp. 1–5. [11] t. e. castelo de oliveira, m. bollen, p. f. ribeiro, p. m. s. de carvalho, a. c. zambroni, and b. d. bonatto, “the concept of dynamic hosting capacity for distributed energy resources: analytics and practical considerations,” energies, vol. 12, no. 13, p. 2576, jul. 2019. [12] m. d. braga, s. d. machado, i. c. oliveira, t. e. c. de oliveira, p. f. ribeiro, and b. i. l. lopes, “harmonic hosting capacity approach in a radial distribution system due to pv integration using open dss,” in 2018 13th ieee international conference on industry applications (induscon), nov. 2018, pp. 222–228. [13] m. al-saffar, s. zhang, a. nassif, and p. musilek, “assessment of photovoltaic hosting capacity of existing distribution circuits,” in 2019 ieee canadian conference of electrical and computer engineering (ccece), may 2019, pp. 1–4. [14] d. syafrianto, k. marojahan banjar-nahor, and n. hariyanto, “optimized allocation of solar pv in batam-bintan power system 2021-2025,” in 2021 3rd international conference on high voltage engineering and power systems (ichveps), oct. 2021, pp. 149–154. [15] s. k. sahu and d. ghosh, “photovoltaic hosting capacity increment in an unbalanced active distribution network,” in 2021 1st international conference on power electronics and energy (icpee), jan. 2021, pp. 1–5. [16] e. kazemi-robati, h. hafezi, r. faranda, m. s. sepasian, and p. sodini, “hosting capacity enhancement and voltage profile improvement using series power electronic compensator in lv distribution networks,” in 2021 international conference on smart energy systems and technologies (sest), sep. 2021, pp. 1–5. [17] n. soukaina, i. moufid, a. boharb, h. e. l. moussaoui, t. lamhamdi, and h. el markhi, “analysis and comparison of pv hosting capacity mathematical models: a case study of a moroccan distribution grid,” in 2022 2nd international conference on innovative research in applied science, engineering and technology (iraset), mar. 2022, pp. 1–5. [18] d. s. nair and r. t, “investigation on impact of solar pv penetration on the operation of protective relays in a distribution system using python,” in 2021 ieee conference on technologies for sustainability (sustech), apr. 2021, pp. 1–8. [19] s. ismael, s. abdel aleem, a. abdelaziz, and a. zobaa, “probabilistic hosting capacity enhancement in non-sinusoidal power distribution systems using a hybrid psogsa optimization algorithm,” energies, vol. 12, no. 6, p. 1018, mar. 2019. [20] b. a. thango, u. b. akuru, j. a. jordaan, l. s. sikhosana, and a. f. nnnachi, “evaluating the harmonic effects on the thermal performance of distributed photovoltaic power generation systems,” in 2021 ieee pes/ias powerafrica, aug. 2021, pp. 1– 5. [21] digsilent powerfactory, “user manual digsilent power factory version 15,” digsilent gmbh, heinrich-hertz-straße 9, 2014. https://mev.lipi.go.id/ https://web.pln.co.id/stakeholder/ruptl https://web.pln.co.id/stakeholder/ruptl https://web.pln.co.id/stakeholder/ruptl https://peraturan.bpk.go.id/home/details/185162/uu-no-7-tahun-2021 https://peraturan.bpk.go.id/home/details/185162/uu-no-7-tahun-2021 https://peraturan.bpk.go.id/home/details/185162/uu-no-7-tahun-2021 https://jdih.esdm.go.id/index.php/web/result/2120/detail https://jdih.esdm.go.id/index.php/web/result/2120/detail https://jdih.esdm.go.id/index.php/web/result/2120/detail https://jdih.esdm.go.id/index.php/web/result/2120/detail https://jdih.esdm.go.id/index.php/web/result/2120/detail https://doi.org/10.1016/j.renene.2018.07.008 https://doi.org/10.1016/j.renene.2018.07.008 https://doi.org/10.1016/j.renene.2018.07.008 https://doi.org/10.1016/j.renene.2018.07.008 https://doi.org/10.3390/en13112758 https://doi.org/10.3390/en13112758 https://doi.org/10.3390/en13112758 https://doi.org/10.3390/en13112758 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/ecti-con54298.2022.9795436 https://doi.org/10.1109/naps50074.2021.9449771 https://doi.org/10.1109/naps50074.2021.9449771 https://doi.org/10.1109/naps50074.2021.9449771 https://doi.org/10.1109/naps50074.2021.9449771 https://doi.org/10.1109/naps50074.2021.9449771 https://doi.org/10.1201/b16455 https://doi.org/10.1201/b16455 https://doi.org/10.1016/j.ijepes.2021.107342 https://doi.org/10.1016/j.ijepes.2021.107342 https://doi.org/10.1016/j.ijepes.2021.107342 https://doi.org/10.1016/j.ijepes.2021.107342 https://doi.org/10.1109/pesgm40551.2019.8973900 https://doi.org/10.1109/pesgm40551.2019.8973900 https://doi.org/10.1109/pesgm40551.2019.8973900 https://doi.org/10.1109/pesgm40551.2019.8973900 https://doi.org/10.1109/pesgm40551.2019.8973900 https://doi.org/10.3390/en12132576 https://doi.org/10.3390/en12132576 https://doi.org/10.3390/en12132576 https://doi.org/10.3390/en12132576 https://doi.org/10.3390/en12132576 https://doi.org/10.1109/induscon.2018.8627342 https://doi.org/10.1109/induscon.2018.8627342 https://doi.org/10.1109/induscon.2018.8627342 https://doi.org/10.1109/induscon.2018.8627342 https://doi.org/10.1109/induscon.2018.8627342 https://doi.org/10.1109/ccece.2019.8861957 https://doi.org/10.1109/ccece.2019.8861957 https://doi.org/10.1109/ccece.2019.8861957 https://doi.org/10.1109/ccece.2019.8861957 https://doi.org/10.1109/ichveps53178.2021.9601028 https://doi.org/10.1109/ichveps53178.2021.9601028 https://doi.org/10.1109/ichveps53178.2021.9601028 https://doi.org/10.1109/ichveps53178.2021.9601028 https://doi.org/10.1109/ichveps53178.2021.9601028 https://doi.org/10.1109/icpee50452.2021.9358688 https://doi.org/10.1109/icpee50452.2021.9358688 https://doi.org/10.1109/icpee50452.2021.9358688 https://doi.org/10.1109/icpee50452.2021.9358688 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/sest50973.2021.9543246 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/iraset52964.2022.9737893 https://doi.org/10.1109/sustech51236.2021.9467474 https://doi.org/10.1109/sustech51236.2021.9467474 https://doi.org/10.1109/sustech51236.2021.9467474 https://doi.org/10.1109/sustech51236.2021.9467474 https://doi.org/10.3390/en12061018 https://doi.org/10.3390/en12061018 https://doi.org/10.3390/en12061018 https://doi.org/10.3390/en12061018 https://doi.org/10.3390/en12061018 https://doi.org/10.1109/powerafrica52236.2021.9543144 https://doi.org/10.1109/powerafrica52236.2021.9543144 https://doi.org/10.1109/powerafrica52236.2021.9543144 https://doi.org/10.1109/powerafrica52236.2021.9543144 https://doi.org/10.1109/powerafrica52236.2021.9543144 https://www.academia.edu/40677599/powerfactory_15_user_manual_dig_silent_powerfactory https://www.academia.edu/40677599/powerfactory_15_user_manual_dig_silent_powerfactory https://www.academia.edu/40677599/powerfactory_15_user_manual_dig_silent_powerfactory introduction ii. materials and methods voltage increase calculation b. calculation of dynamic hosting capacity short circuit contribution current d. harmonic contribution e. flowchart of this research f. profile characteristic g. constraint 1) voltage 2) thermal loading 3) harmonic 4) harmonic data simulation iii. results and discussions a. scenario 1: voltage constraint 1) quasi-dynamic simulation in customer 1 2) quasi-dynamic simulation in customer 2 3) quasi-dynamic simulation in customer 3 4) quasi-dynamic simulation in customer 4 5) quasi-dynamic simulation in customer 5 spread capacity in each customer scenario 2: voltage, thermal loading, harmonic, and protection 1) the difference between calculation and simulation results 2) quasi-dynamic results for scenario 2 iv. conclusion declarations author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.72-79 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: m. z. romdlony et al., “lstm-based forecasting on electric vehicles battery swapping demand: addressing infrastructure challenge in indonesia,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 72-79, july 2023. lstm-based forecasting on electric vehicles battery swapping demand: addressing infrastructure challenge in indonesia muhammad zakiyullah romdlony a, rashad abul khayr a, *, aam muharam b, eka rakhman priandana c, sudarmono sasmono a, muhammad ridho rosa a, e, irwan purnama a, d, amin b, ridlho khoirul fachri a a school of electrical engineering, telkom university jalan telekomunikasi terusan buah batu, bandung, 40257, indonesia b research center for transportation technology, national research and innovation agency (brin) kawasan sains dan teknologi (kst) habibie, jalan raya puspiptek – serpong, tangerang selatan, 15310, indonesia c research center for energy conversion and conservation, national research and innovation agency (brin) kawasan sains dan teknologi (kst) habibie, jalan raya puspiptek – serpong, tangerang selatan, 15310, indonesia d research center for smart mechatronics, national research and innovation agency (brin) kawasan sains dan teknologi (kst) samadikun, jalan cisitu – sangkuriang, bandung, 40135, indonesia e faculty of science and engineering, university of groningen nijenborgh 4, groningen, 9747 ag, the netherlands received 11 june 2023; revised 27 june 2023; accepted 3 july 2023; published online 31 july 2023 abstract this article aims to design a model for forecasting the number of vehicles arriving at the battery swap station (bss). in our case, we study the relevance of the proposed approach given the rapid increase in electric vehicle users in indonesia. due to the vehicle electrification program from the government of indonesia and the lack of supporting infrastructure, forecasting battery swap demands is very important for charging schedules. forecasting the number of vehicles is done using machine learning with the long short-term memory (lstm) method. the method is used to predict sequential data because of its ability to review previous data in addition to the current input. the result of the forecasting using the lstm method yields a prediction score using the root-mean-square error (rmse) of 2.3079 × 10−6. the forecasted data can be combined with the battery charging model to acquire predicted hourly battery availability that can be processed further for optimization and scheduling. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: battery swap station (bss); demand forecasting; long short-term memory (lstm). i. introduction machines that require combustion as the primary energy generator, such as those in factories and motor vehicles, produce hazardous gases. these gases play an active role in the increase in earth's temperature. this increase in temperature is caused by the effect of gases that can reflect the sun’s heat that is supposed to come out of the earth’s atmosphere back to the earth’s surface. rising global temperatures can lead to natural disasters. therefore, the united nations (un) signed the agreement to reduce these hazardous gas emissions called the paris agreement on 12 december 2015 [1]. this agreement aims to address climate change by reducing greenhouse gas emissions that can reflect solar heat. to support this cooperation, greenhouse gas sources such as motor vehicles must be reduced. however, motor vehicles are widely used in everyday life and are difficult to reduce. therefore, it is necessary to replace motor vehicles that have lower or no emissions. indonesia has implemented regulations to reduce emissions from motor vehicles by instituting co2 reduction in the transportation sector, i.e., the use of electric vehicles. with the release of presidential regulation 55/2019 on battery-powered electric * corresponding author. tel: +62-81322797175 e-mail address: rashadaka@student.telkomuniversity.ac.id https://dx.doi.org/10.14203/j.mev.2023.v14.72-79 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.72-79 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:rashadaka@student.telkomuniversity.ac.id m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 73 vehicles, the popularity of electric vehicles began to increase once more. in addition, the local government has enacted a number of subsidiary policies to expedite the creation of electric vehicles. as a consequence of this regulation, there is a surge in the number of electric vehicles, particularly electric motorcycles. some motorcycles brands have been manufactured in the country, resulting in a rapid increase in the number of electric vehicles by 2020 [2]. these electric vehicles require an energy source, but their small shape makes electric vehicles only use batteries as their energy source. the use of this battery will cause problems with charging the battery itself. the battery requires high power. this will increase considering the increasing consumption of electric vehicles. this power use should be scheduled so that the user does not wait long and there is no surge in power use. scheduling from battery charging can be charging at a time that not many users use [3] [4] [5], combined with renewable energy [6] [7] [8], or trying to increase profits [9] [10]. the scheduling method mentioned above requires an accurate prediction of battery availability to be implemented correctly. to achieve acceptable accuracy, battery availability can be predicted using battery demand and battery charging methods. this study aims to develop an accurate prediction of battery availability by using forecasted battery demand and battery charge time using commonly used charging methods. ii. materials and methods battery availability for a battery swap station (bss), as mentioned in the introduction, can be predicted using vehicle arrivals and battery charging times. battery charging can be achieved by using the appropriate battery charging model. there are many charging models that can be used by electric vehicle batteries. but as mentioned later, only one model is commonly used by electric vehicle batteries due to ease of implementation. battery demand data for battery availability can be acquired by using forecasting. data from the past can be processed using a neural network (nn), and the number of vehicles that use the bss for a given time frame can be acquired. data acquired from a nn can be used to represent battery demands, assuming that one vehicle only swaps for a single battery. in the following subsections, we will elaborate more about the battery charging model, forecasting model, and parameter used for simulation. a. battery charging model lithium batteries are widely used for electric vehicles due to their high energy density and opencircuit voltage. because of its high energy density, this type of battery is prone to exploding at high temperatures. to anticipate such incidents, especially when charging, lithium batteries require a specialized charging method. there are many charging methods that can be used to charge lithium batteries, with varying efficiency and complexity. the charging method constant current (cc), constant voltage (cv), and constant power (cp) are the least complex charging methods but also the least efficient, with the highest possibility of damaging the battery during charging [11]. another method is electrochemical model-based charging, which produces the highest efficiency but also has a high complexity, making implementation of this method difficult [12]. the last method to consider is constant current-constant voltage (cccv), which has average efficiency and average complexity compared to other charging methods. but with its low complexity, the cccv method has become the most commonly used due to its ease of implementation while still maintaining an acceptable level of efficiency. the cccv method begins with a cc until a predetermined voltage is reached. once the voltage reaches this threshold, the charging voltage becomes constant while the charging current decreases exponentially [9] [13]. increased internal resistance causes a decrease in current during cv operation. this resistance will increase as the battery's temperature and state of charge (soc) increase during charging [14]. when charging in the cc stage, only the charging voltage is affected by the battery's internal resistance. after the charging change stage, the current will decrease exponentially as the internal resistance increases. the charging current for cc-cv methods for both stages is depicted in figure 1. this battery charging method will be required in the formation of the schedule for the battery swap station (bss). with the correct charging model, the scheduling of the bss will be more efficient. it also requires calculating the soc of the battery shown in equation (1). 𝐾 = 𝐾0 + ∫ 𝐼𝑏 𝐶𝑏 𝑑𝑑 (1) the soc of the battery (𝐾) will depend on the soc before charging (𝐾0 ), charging current (𝐼𝑏 ), and battery capacity that can be used. (𝐶𝑏). it can be seen from the equation that the soc of a battery will depend on the health of the battery itself. in addition, the charging current will determine sooner or later when the battery is charged [15]. b. forecasting model sequential data can be predicted using artificial intelligence. this intelligence can be created with various machine learning methods, such as artificial neural networks (anns). ann is a machine learning method inspired by early models of sensory processing in the brain. this can be simulated using a network of neuron models on a computer. the network can break a feature from the input so that the computer can identify the input from the feature it has learned. because this machine can learn, ann is widely used in classification problems [16]. these anns will develop into recurrent neural networks (rnns) to process sequential data. m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 74 rnns have an architecture where there is a layer (hidden layer or output layer) that becomes the input of the input layer. the architecture allows this method to detect relationships sequentially. this method developed rapidly with the emergence of long short-term memory (lstm) and gated recurrent unit (gru), which made it possible to remember distant past circumstances [17]. the ability to make predictions with past data makes scheduling methods like the day-ahead method possible [6]. gru is a type of rnn that aims to resolve problems in the long term by using reset and update gates. both gates are used to measure the correlation between the previous state and the next forecasting step. gru can be trained using a smaller dataset than lstm. by using a smaller dataset, gru can be trained faster due to the two gates of gru [18] [19]. lstm is a development of rnn that can remember information for a longer period of time than rnn. this is due to the addition of memory blocks to an rnn cell, where rnn cells themselves are a group of rnn networks. this additional memory block makes lstm more accurate than gru with a larger dataset and a longer training time. as accuracy is valued more than time, forecasting using lstm was considered the main model for this article. the additional memory blocks are arranged in threegates: input gate (𝑖(𝑡)), output gate (𝑜(𝑡)), and forget gate (𝑓(𝑡) ) [20] [21] [22]. this arrangement for the lstm cell can be seen in figure 2. based on figure 2, lstm cells can be represented in mathematical equations as equation (2) to equation (7). 𝑓(𝑡) = 𝜎�𝑊𝑓𝑓𝑥(𝑡) + 𝑊𝑓ℎℎ(𝑡−1) + 𝑏𝑓� (2) 𝑖(𝑡) = 𝜎�𝑊𝑖𝑓𝑥(𝑡) + 𝑊𝑖ℎℎ(𝑡−1) + 𝑏𝑖� (3) 𝑜(𝑡) = 𝜎�𝑊𝑜𝑓𝑥(𝑡) + 𝑊𝑜ℎℎ(𝑡−1) + 𝑏𝑜� (4) 𝑝�(𝑡) = tanh�𝑊𝑝𝑓𝑥(𝑡) + 𝑊𝑝ℎℎ(𝑡−1) + 𝑏𝑝� (5) 𝑝(𝑡) = 𝑓(𝑡) ∙ 𝑝(𝑡−1) + 𝑖(𝑡) ∙ 𝑝�(𝑡) (6) ℎ(𝑡) = 𝑜(𝑡) ∙ tanh�𝑝(𝑡)� (7) where 𝑝(𝑡) shows the previous cell memory and ℎ(𝑡) figure 2. lstm cell structure figure 1. battery charging current with cc-cv charging method 0 20 40 60 80 100 soc (%) -0.05 0 0.05 0.1 0.15 0.2 0.25 c ur re nt (a ) m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 75 is the output of the cell. 𝑏𝑓, 𝑏𝑖, 𝑏𝑜, and 𝑏𝑝 are bias of each gate and predicted memory. 𝑊𝑓𝑓, 𝑊𝑖𝑓, 𝑊𝑜𝑓, and 𝑊𝑝𝑓 are the weights for input, while 𝑊𝑓ℎ, 𝑊𝑖ℎ, 𝑊𝑜ℎ, and 𝑊𝑝ℎ themselves are those for cell output that all have their own values depending on the gate and predicted memory. the values of the weight and bias will be replaced by the machine so that the predictive value is close to the training data value. sigmoid (𝜎 ) and hyperbolic (tanh) functions are defined as equation (8) and equation (9). 𝜎(𝑥) = 1 1+𝑒−𝑥 (8) tanh(𝑥) = 𝑒 𝑥−𝑒−𝑥 𝑒𝑥+𝑒−𝑥 (9) c. simulation parameter both models required a predefined parameter to achieve an accurate prediction of battery availability. for prediction simulation, battery heterogeneity was not considered, as bss for this simulation can only serve one type of battery. a battery that is commonly used for two-wheel electric vehicles in indonesia was considered for this simulation. for lithium-ion (li-ion) batteries, the battery parameter is shown in table 1 alongside the bss parameter and the available commercial charger for charge current. the battery specified in table 1 during extensive use can be used for around two hours. considering extensive use and bss peak hours, a dataset was generated with tendencies for single days, as shown in figure 3. peak hour was considered to happen between 15 o’clock and 19 o’clock, when students and workers were going home. other possible peaks, like before leaving home and around lunch, were also considered for the dataset. the dataset used for this simulation is randomly generated. both models required a predefined parameter to achieve an accurate prediction of battery availability. for prediction simulation, battery heterogeneity was not considered, as bss for this simulation can only serve one type of battery. a battery that is commonly used for two-wheel electric vehicles in indonesia was considered for this simulation. for li-ion batteries, the battery parameter is shown in table 1 alongside the bss parameter. iii. results and discussions the battery charging model and the forecasting model described earlier were tested using the parameters mentioned above. the battery charging model was tested using the parameters shown in table 1. the effects of charge current and soc threshold were also tested to find their connection to battery charging time. the forecasting model was trained using the generated dataset mentioned above and scored using the root-mean-square error (rmse) to quantify forecasting model quality. after testing, these two models were combined to create a prediction for battery availability. a. battery charging the effect of the current on battery charging can be tested with equation (1). with the same initial health and soc, battery charging with a current of 0.25 c and 0.1 c was tested, with c being the table 1. simulation parameter parameter value battery voltage 75 v charge current 5 a and 2 a battery capacity 20 ah battery charging slot 12 maximum available battery 9 figure 3. hourly vehicle amounts for one day 0 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ve hi cl e a m ou nt time (hour) m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 76 battery's maximum capacity. the results of this test are shown in figure 4. the charging results show the effect of current on battery charging time. it appears that charging using 0.25 c reaches 80 % soc in three hours, while charging with 0.1 c achieves the same in seven hours. this shows the advantages of high-current charging, but high-current charging will cause heat and reduce the health of the battery. the test uses a battery charger with the same cccv voltage limit. because the voltage limit is a constant that has been set on the previous battery charger, these numbers can be modified and tested for their effects. for this test, the limits of 80 %, 70 %, and 60 % soc were tested with a charging current of 0.1 c. the result of this test is shown in figure 5. figure 5 shows charging differences with previously specified voltage limits, indicating changes in battery charging time. the difference between 80 % and 70 % shows that it takes 6 minutes to reach the 80 % soc. the difference between the limit of 70 % and 60 % indicates one hour to reach an 80 % soc. these tests showed that increased voltage limits would result in the battery reaching a soc of 80 % faster without considering battery health. b. vehicle forecasting lstm has the ability to predict sequential data from previous time series. in this paper, we use randomly generated historical data on vehicle arrivals at bsss. in addition to its architecture that takes input from other layers, lstm is a predictive method that is suitable for predicting the number of vehicles coming every hour. it is known that the vehicle is coming, so that the battery replacement station can prepare the batteries to be removed. figure 6 shows the prediction results of vehicle amounts using lstm for ten days or 240 hours to show the effect of previous days. figure 4. comparison of different charge current effects for battery soc with the cccv charging method figure 5. comparison of different voltage cutoff effects for battery soc with the cccv charging method 0 5 10 15 20 time (hour) 0 0.2 0.4 0.6 0.8 1 s oc 0.1c 0.25c 0 5 10 15 20 time (hour) 0 0.2 0.4 0.6 0.8 1 s oc 80% 70% 60% m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 77 the result of the prediction using lstm results in a rmse score of 2.3079 x 10-6. the score is small enough for rmse to be used for scheduling battery replacement stations. c. battery availability battery charging models and vehicle forecasting were combined to predict hourly battery availability. the prediction was made using hourly vehicle amounts, as shown in figure 3, and parameters, as shown in table 1, with the soc threshold at 80 %. for this simulation, the battery is considered swappable when the soc reaches 80 % with a uniform depth of discharge (dod) of 100 % for every battery swap. the result of battery availability prediction is shown in figure 7. charge currents during cc are 2 a and 5 a. bss was having difficulty meeting battery swap demand at peak hours. battery availability was a constant zero from hours 15 to 20 for 5 a charging current and from hours 14 to 21 for 2 a. the unmet battery swap demand during zero battery availability for 5 a and 2 a charging currents is shown in figure 8. figure 8 shows bss's difficulty meeting battery demand during peak hours. this unmet demand comes from high demand that can be seen in hours 16 to 17, where demand reaches nine batteries, or equal to the maximum battery available. another factor is the slow charge time that can be seen in bss with a 2 a charge current, which is unable to restore its battery availability to the maximum at the end of the day. figure 6. comparison of real and predicted hourly vehicle amounts figure 7. comparison of bss battery availability for charge current 5 a and 2 a 0 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ba tt er y a va ila bi lit y time (hour) 5a 2a m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 78 iv. conclusion this study aims to develop an accurate prediction of battery availability by using forecasted battery demand and battery charge time using commonly used charging methods. simulation shows that the combination of battery charging methods using cccv and forecasting using the lstm model can be used to predict battery availability. the simulation also shows bss’s difficulty meeting battery demand during peak hours. that is because battery swap demands are equal to or greater than the maximum battery availability. another reason is that it takes three hours to seven hours for the battery to charge to soc 80%, depending on the charge current. future research efforts will focus on optimizing adaptive charging, which can change its charging current to either meet battery demand or conserve battery health. acknowledgements this research was supported by the indonesia endowment funds for education (lpdp) in collaboration with the national research and innovation agency (brin) under the research and innovation for advanced indonesia (riim) research scheme with contract number: 50/iv/ks/06/2022 and 202/sam4/ppm/2022. declarations author contribution m.z. romdlony, r.a. khayr, a. muharam, e.r. priandana, s. sasmono, m.r. rosa, i. purnama, amin, r.k. fachri contributed equally as the main contributor to this paper. all authors read and approved the final paper. funding statement this research was funded by indonesia endowment funds for education (lpdp), ministry of finance of republic indonesia. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] united nations climate change. the paris agreement. [accessed: 8-june-2023]. [2] the central government. presidential regulations on accelerating the battery-based electric vehicle program for road transport. [accessed: 7-june-2023]. [3] y. li et al., “optimal scheduling of isolated microgrid with an electric vehicle battery swapping station in multi-stakeholder scenarios: a bi-level programming approach via real-time pricing,” appl. energy, vol. 232, pp. 54–68, dec., 2018. [4] m. sufyan, n. a. rahim, m. a. muhammad, c. k. tan, s. r. s. raihan, and a. h. a. bakar, “charge coordination and battery lifecycle analysis of electric vehicles with v2g implementation,” electric power systems research, vol. 184, p. 106307, jul., 2020. [5] j. g. -guarin, w. infante, j. ma, d. alvarez, and s. rivera, “optimal scheduling of smart microgrids considering electric vehicle battery swapping stations,” international journal of electrical and computer engineering (ijece), vol. 10, no. 5, p. 5093, oct., 2020. [6] m. s. islam, n. mithulananthan, and d. q. hung, “a day-ahead forecasting model for probabilistic ev charging loads at business premises,” ieee trans sustain. energy, vol. 9, no. 2, pp. 741–753, apr., 2018. [7] r. ghotge, y. snow, s. farahani, z. lukszo, and a. van wijk, “optimized scheduling of ev charging in solar parking lots for local peak reduction under ev demand uncertainty,” energies (basel), vol. 13, no. 5, p. 1275, mar., 2020. [8] n. kaewdornhan, c. srithapon, r. liemthong, and r. chatthaworn, “real-time multi-home energy management with ev charging scheduling using multi-agent deep reinforcement learning optimization,” energies (basel), vol. 16, no. 5, p. 2357, mar., 2023. [9] h. wu, g. k. h. pang, k. l. choy, and h. y. lam, “an optimization model for electric vehicle battery charging at a figure 8. comparison of bss unmet demands for charge current 5 a and 2 a 0 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 u nm et d em an d time (hour) 5a 2a https://mev.lipi.go.id/ https://unfccc.int/process-and-meetings/the-paris-agreement https://unfccc.int/process-and-meetings/the-paris-agreement https://peraturan.bpk.go.id/home/details/116973/perpres-no-55-tahun-2019 https://peraturan.bpk.go.id/home/details/116973/perpres-no-55-tahun-2019 https://peraturan.bpk.go.id/home/details/116973/perpres-no-55-tahun-2019 https://doi.org/10.1016/j.apenergy.2018.09.211 https://doi.org/10.1016/j.apenergy.2018.09.211 https://doi.org/10.1016/j.apenergy.2018.09.211 https://doi.org/10.1016/j.apenergy.2018.09.211 https://doi.org/10.1016/j.epsr.2020.106307 https://doi.org/10.1016/j.epsr.2020.106307 https://doi.org/10.1016/j.epsr.2020.106307 https://doi.org/10.1016/j.epsr.2020.106307 https://doi.org/10.1016/j.epsr.2020.106307 https://doi.org/10.11591/ijece.v10i5.pp5093-5107 https://doi.org/10.11591/ijece.v10i5.pp5093-5107 https://doi.org/10.11591/ijece.v10i5.pp5093-5107 https://doi.org/10.11591/ijece.v10i5.pp5093-5107 https://doi.org/10.11591/ijece.v10i5.pp5093-5107 https://doi.org/10.1109/tste.2017.2759781 https://doi.org/10.1109/tste.2017.2759781 https://doi.org/10.1109/tste.2017.2759781 https://doi.org/10.1109/tste.2017.2759781 https://doi.org/10.3390/en13051275 https://doi.org/10.3390/en13051275 https://doi.org/10.3390/en13051275 https://doi.org/10.3390/en13051275 https://doi.org/10.3390/en16052357 https://doi.org/10.3390/en16052357 https://doi.org/10.3390/en16052357 https://doi.org/10.3390/en16052357 https://doi.org/10.3390/en16052357 https://doi.org/10.1109/tvt.2017.2758404 https://doi.org/10.1109/tvt.2017.2758404 m.z. romdlony et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 72-79 79 battery swapping station,” ieee trans. veh. technol., vol. 67, no. 2, pp. 881–895, feb., 2018. [10] x. zhang, y. cao, l. peng, n. ahmad, and l. xu, “towards efficient battery swapping service operation under battery heterogeneity,” ieee trans. veh. technol., vol. 69, no. 6, pp. 6107–6118, jun., 2020. [11] q. lin, j. wang, r. xiong, w. shen, and h. he, “towards a smarter battery management system: a critical review on optimal charging methods of lithium ion batteries,” energy, vol. 183, pp. 220–234, sep., 2019. [12] m. xu, r. wang, p. zhao, and x. wang, “fast charging optimization for lithium-ion batteries based on dynamic programming algorithm and electrochemical-thermalcapacity fade coupled model,” j. power sources, vol. 438, p. 227015, oct., 2019. [13] y. li, k. li, y. xie, j. liu, c. fu, and b. liu, “optimized charging of lithium-ion battery for electric vehicles: adaptive multistage constant current–constant voltage charging strategy,” renew. energy, vol. 146, pp. 2688–2699, feb., 2020. [14] y.-h. chiang, w.-y. sean, and j.-c. ke, “online estimation of internal resistance and open-circuit voltage of lithium-ion batteries in electric vehicles,” j. power sources, vol. 196, no. 8, pp. 3921–3932, apr., 2011. [15] m. c. argyrou, p. christodoulides, c. c. marouchos, and s. a. kalogirou, “hybrid battery-supercapacitor mathematical modeling for pv application using matlab/simulink,” in 2018 53rd international universities power engineering conference (upec), ieee, sep., 2018. [16] b. yegnanarayana, artificial neural networks. delhi: phi learning pvt. ltd., 2009. [17] j. l. smith, “advances in neural networks and potential for their application to steel metallurgy,” materials science and technology, vol. 36, no. 17, pp. 1805–1819, nov., 2020. [18] z. niu, z. yu, w. tang, q. wu, and m. reformat, “wind power forecasting using attention-based gated recurrent unit network,” energy, vol. 196, p. 117081, apr., 2020. [19] y. zhang, j. tang, z. he, j. tan, and c. li, “a novel displacement prediction method using gated recurrent unit model with time series analysis in the erdaohe landslide,” natural hazards, vol. 105, no. 1, pp. 783–813, jan., 2021. [20] y. yu, x. si, c. hu, and j. zhang, “a review of recurrent neural networks: lstm cells and network architectures,” neural comput., vol. 31, no. 7, pp. 1235–1270, jul., 2019. [21] k. smagulova and a. p. james, “a survey on lstm memristive neural network architectures and applications,” eur. phys. j. spec. top., vol. 228, no. 10, pp. 2313–2324, oct., 2019. [22] a. a. shalaby, m. f. shaaban, m. mokhtar, h. h. zeineldin, and e. f. el-saadany, “a dynamic optimal battery swapping mechanism for electric vehicles using an lstm-based rolling horizon approach,” ieee transactions on intelligent transportation systems, vol. 23, no. 9, pp. 15218–15232, sep., 2022. https://doi.org/10.1109/tvt.2017.2758404 https://doi.org/10.1109/tvt.2017.2758404 https://doi.org/10.1109/tvt.2020.2989195 https://doi.org/10.1109/tvt.2020.2989195 https://doi.org/10.1109/tvt.2020.2989195 https://doi.org/10.1109/tvt.2020.2989195 https://doi.org/10.1016/j.energy.2019.06.128 https://doi.org/10.1016/j.energy.2019.06.128 https://doi.org/10.1016/j.energy.2019.06.128 https://doi.org/10.1016/j.energy.2019.06.128 https://doi.org/10.1016/j.jpowsour.2019.227015 https://doi.org/10.1016/j.jpowsour.2019.227015 https://doi.org/10.1016/j.jpowsour.2019.227015 https://doi.org/10.1016/j.jpowsour.2019.227015 https://doi.org/10.1016/j.jpowsour.2019.227015 https://doi.org/10.1016/j.renene.2019.08.077 https://doi.org/10.1016/j.renene.2019.08.077 https://doi.org/10.1016/j.renene.2019.08.077 https://doi.org/10.1016/j.renene.2019.08.077 https://doi.org/10.1016/j.jpowsour.2011.01.005 https://doi.org/10.1016/j.jpowsour.2011.01.005 https://doi.org/10.1016/j.jpowsour.2011.01.005 https://doi.org/10.1016/j.jpowsour.2011.01.005 https://doi.org/10.1109/upec.2018.8541933 https://doi.org/10.1109/upec.2018.8541933 https://doi.org/10.1109/upec.2018.8541933 https://doi.org/10.1109/upec.2018.8541933 https://doi.org/10.1109/upec.2018.8541933 https://books.google.co.id/books?id=rttvuvu_xl4c&lpg=pp1&pg=pp1#v=onepage&q&f=false https://books.google.co.id/books?id=rttvuvu_xl4c&lpg=pp1&pg=pp1#v=onepage&q&f=false https://doi.org/10.1080/02670836.2020.1839206 https://doi.org/10.1080/02670836.2020.1839206 https://doi.org/10.1080/02670836.2020.1839206 https://doi.org/10.1016/j.energy.2020.117081 https://doi.org/10.1016/j.energy.2020.117081 https://doi.org/10.1016/j.energy.2020.117081 https://doi.org/10.1007/s11069-020-04337-6 https://doi.org/10.1007/s11069-020-04337-6 https://doi.org/10.1007/s11069-020-04337-6 https://doi.org/10.1007/s11069-020-04337-6 https://doi.org/10.1162/neco_a_01199 https://doi.org/10.1162/neco_a_01199 https://doi.org/10.1162/neco_a_01199 https://doi.org/10.1140/epjst/e2019-900046-x https://doi.org/10.1140/epjst/e2019-900046-x https://doi.org/10.1140/epjst/e2019-900046-x https://doi.org/10.1109/tits.2021.3138892 https://doi.org/10.1109/tits.2021.3138892 https://doi.org/10.1109/tits.2021.3138892 https://doi.org/10.1109/tits.2021.3138892 https://doi.org/10.1109/tits.2021.3138892 https://doi.org/10.1109/tits.2021.3138892 introduction ii. materials and methods a. battery charging model b. forecasting model c. simulation parameter iii. results and discussions a. battery charging b. vehicle forecasting c. battery availability iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references microsoft word vol.01_no.2 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 43 pe�gura�ga� subsidi bbm da� polusi udara melalui kebijaka� program ko�versi dari bbm ke bbg u�tuk ke�daraa� di propi�si jawa barat vita susanti, agus hartanto, ridwan a.s., hendri m.s., estiko r., a. hapid pusat penelitian tenaga listrik dan mekatronik lipi komp. lipi bandung, jl sangkuriang, gd 20, lt 2, bandung, jawa barat 40135, indonesia vitasusanti@gmail.com, ahartantots@yahoo.com, ridwanarief_rais@yahoo.com, hendri_maja@yahoo.co.id, estiko@hotmail.com, abdul.hapid@lipi.go.id diterima: 26 oktober 2010; direvisi: 29 november 2010; disetujui: 10 desember 2010; terbit online: 24 desember 2010. abstrak populasi kendaraan di indonesia yang berbahan bakar minyak (bbm) setiap tahunnya semakin meningkat sedangkan cadangan minyak sendiri semakin menipis dan harus impor. hal ini menyebabkan subsidi bbm dan polusi udara juga akan meningkat. untuk mengatasi hal tersebut diperlukan bahan bakar alternatif yang ramah lingkungan sebagai pengganti bbm untuk kendaraan. salah satu bahan bakar alternatif tersebut adalah bahan bakar gas (bbg). dilihat dari jumlah kendaraan dan infrastruktur jaringan pipa gas, daerah jawa barat bagian utara sangat berpotensi untuk dijadikan tempat dilaksanakannya program konversi bbm ke bbg pada kendaraan. populasi kendaraan di wilayah tersebut meliputi depok, cibinong, bogor, bekasi, cikarang, karawang, purwakarta, cirebon, dan bandung yang berjumlah 878.505 unit. dari data tersebut dapat disimulasikan seberapa besar potensi keuntungan yang akan didapat dengan mengkonversi 10% dari jumlah kendaraan pada tahun pertama dan kenaikan pertahunnya sebesar 5%. dengan dana investasi sebesar 3,16 triliyun rupiah maka akan didapat keuntungan sebesar 14,9 triliun rupiah berupa penghematan subsidi dan penghematan bahan bakar. selain itu, pengurangan emisi yang dikonversi ke cdm (clean development mechanism) dapat menjadi pendapatan daerah dengan total cdm yang dihasilkan selama 5 tahun sebesar us$ 772.385. dari hasil kajian ini dapat disimpulkan bahwa manfaat konversi bbm ke bbg pada kendaraan sangatlah besar. kata kunci : bahan bakar gas, kebijakan, konversi, polusi udara, subsidi. abstract the number of vehicle that use oil (bbm) is increasing every year in indonesia while national oil reserve become smaller, so that the oil should be imported. the impact of using oil are increasing subsidy and air pollution. thus, it is now becoming important to replace oil with another enviromentally friendly energy, one of them is gas (bbg). based on the number of vehicle and infrastructure in gas pipeline, part of northern west java potentially can be chosen for the implementation of conversion program to gas (bbg). the number of vehicle in potential regions such as depok, cibinong, bogor, bekasi, cikarang, karawang, purwakarta, cirebon, and bandung are around 875,505 units. from these data, we simulated the potential profit to be gained each year by converting 10% for the first year and increasing it to 5% for every year. by investing 3.16 trillion for conversion, 14.9 trillion can be achieved in the form of fuel subsidy savings. in addition, emission reduction converted to a cdm (clean development mechanism) can become local revenues. total cdm generated during 5 years predicted is of u.s $ 772,385. from this study, it can be concluded that converting oil (bbm) to gas (bbg) is highly beneficial. keyword: natural gas, policy, conversion, air pollution, subsidy. i. pe�dahulua� a. latar belakang jumlah kendaraan di indonesia dari tahun ke tahun makin meningkat. untuk propinsi jawa barat saja jumlah kendaraan per 30 juni 2010 sebanyak 8,9 juta (kendaraan roda 2 dan roda 4) dan tentu saja emisi yang dihasilkan dari asap kendaraan bermotor tersebut sangatlah besar. di sisi lain, indonesia saat ini bukan lagi negara eksportir minyak. indonesia sejak tahun 2005 mulai mengimpor minyak untuk memenuhi kebutuhan minyak di dalam negeri sehingga pemerintah harus mengeluarkan dana untuk mensubsidi bbm tersebut. pada tahun 2010 ini pemerintah harus mengalokasikan dana untuk subsidi bahan bakar minyak (bbm) sebesar rp 57,4 triliyun, sehingga semakin banyak populasi kendaraan di indonesia maka semakin besar juga subsidi yang harus dialokasikan oleh pemerintah. pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat (vita s, agus h, ridwan as, hendri ms, estiko r, a hapid) pp. 43-52 44 selain masalah sumber energi dan subsidi, muncul juga permasalahan pencemaran lingkungan dari hasil pembakaran bbm pada kendaraan, seperti gas co2 (carbon dioksida), pm10 (particulate matter ≤ 10 µ), pb (timbal), dan lain-lain. presiden republik indonesia, bapak susilo bambang yudhoyono pada pertemuan negara-negara berkembang (group of 77) berjanji akan mengurangi emisi sebesar 26% pada tahun 2020. langkah yang diambil oleh kementrian lingkungan hidup dan jajarannya untuk mengurangi emisi tersebut adalah dengan penanaman pohon, pengujian emisi kendaraan bermotor dan pengolahan sampah. namun demikian sebenarnya sumber emisi terbesar berasal dari asap kendaraan bermotor. data dari departemen perhubungan menunjukkan bahwa polusi co2 yang dihasilkan pada tahun 2003 dari sistem transportasi adalah sebesar 168 juta ton. sejalan dengan bertambahnya kendaraan, maka pada tahun 2007 pencemaran co2 juga bertambah menjadi sekitar 324 juta ton [1]. perkembangan pencemaran lingkungan tersebut memberikan dampak yang tidak baik bagi kesehatan penduduk. contohnya seperti yang terdapat di kota batam dimana dampak kesehatan yang ditimbulkan oleh pencemaran polutan pm10 dan pb adalah berupa kasus penderita mortalitas prematur, penyakit saluran pernafasan dengan rawat inap, kasus gawat darurat, terhambatnya hari aktivitas, bronkhitis pada anak-anak, kasus baru asma kronis, serangan asma, berkurangnya hari aktivitas karena gejala penyakit, kasus kardiovaskular, kehilangan iq per anak, hipertensi, serangan jantung tidak fatal, dan mortalitas. biaya kesehatan total yang meliputi ongkos pengobatan yang harus dikeluarkan akibat polutan pm10 dan pb serta production loss yang ditimbulkan untuk seluruh kota batam mencapai nilai rp 630,733 milyar (8% dari pdrb kota batam) [1]. data lainya yaitu dari hasil penelitian institut teknologi bandung yang dilakukan pada tahun 2005 bahwa 66% anak sekolah yang sekolahnya berada di pusat kota bandung, darahnya mengandung polutan yang melebihi ambang batas [2]. pembahasan tentang dampak dari polusi kendaraan bermotor tidak lepas dari populasi kendaraan bermotor tersebut yang terus meningkat dari tahun ke tahun. berdasarkan data dari dinas pendapatan daerah propinsi jawa barat, jumlah kendaraan roda 4 (kendaraan umum, bukan umum dan dinas) di kabupaten/kota yang potensinya besar seperti depok, cibinong, bogor, bekasi, cikarang, karawang, purwakarta, cirebon dan bandung adalah sebanyak 878.505 unit kendaraan. dari populasi tersebut dapat dihitung emisi co2 yang dihasilkan dengan asumsi jarak tempuh setiap kendaraan adalah 100 km/hari, jumlah hari dalam 1 tahun adalah 350 hari, dengan emisi co2 sebesar 0,1667 kg/km [3], maka besarnya emisi co2 yang dihasilkan selama 1 tahun adalah 5,16 juta ton. dari latar belakang tersebut di atas kiranya dibutuhkan bahan bakar yang ramah lingkungan sebagai pengganti bahan bakar minyak pada kendaraan. salah satu bahan bakar yang ramah lingkungan tersebut adalah bahan bakar gas (bbg). b. tujuan makalah ini bertujuan untuk memberikan gambaran dan informasi mengenai keuntungan yang akan diperoleh bila dilakukan program konversi bbm ke bbg pada kendaraan di propinsi jawa barat. ii. metodologi metodologi yang digunakan pada makalah ini adalah: 1. survey data sekunder dari internet. data-data yang didapat dari internet berupa standar-standar kits konverter yang sudah ada, teknologi kit konverter, perkembangan �atural gas vehicle (ngv) di luar negeri, dan peraturanperaturan yang mendukung konversi dari bbm ke bbg untuk kendaraan. 2. beraudiensi dengan instansi terkait. melakukan audiensi dengan dinas perhubungan di jawa barat, badan pengelolaan lingkungan hidup daerah (bplhd) jawa barat, dinas perindustrian dan energi dki jakarta, perusahaan gas negara (pgn), dan lain lain. tujuan dari audiensi ini adalah untuk mengetahui sudah sejauh mana pelaksanaan konversi dari bbm ke bbg untuk transportasi, kendala-kendala yang dihadapi, kebijakan dan peraturan apasaja yang dikeluarkan oleh instansi tersebut. 3. analisis data. menganalisis data-data tentang kebijakan yang sudah ada di instansi terkait tersebut dan merumuskan kebijakan sementara. dari analisis data tersebut kemudian dihitung mengenai lokasi-lokasi di wilayah jawa barat yang potensial untuk dilaksanakannya program konversi dari bbm ke bbg. lokasi yang dipilih adalah adalah bagian utara jawa barat karena, secara geografis, wilayah tersebut merupakan journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 45 pendukung ibu kota negara dan telah memiliki jaringan pipa gas serta populasi kendaraannya yang tinggi. iii. kebijaka� ko�versi dari bbm ke bbg pembuatan kebijakan konversi dilihat dari perkembangan yang telah terjadi dan manfaat yang akan diperoleh dengan program konversi ini. a. perkembangan konversi dari bbm ke bbg dari data yang didapat, departemen perhubungan sudah mengkaji mengenai konversi dari bbm ke bbg pada kendaraan sejak tahun 1980 dan pada tahun 1988 di jakarta sudah mulai dilakukan program percontohan untuk taksi “blue bird” dengan mengkonversi 500 unit armadanya menggunakan bbg sebagai pengganti bbm. selain taksi “blue bird”, pada tahun 1990 ppd (perusahaan pengangkutan djakarta) juga memiliki 40 unit armada bus menggunakan bbg tipe full dedicated dan 50 unit dengan sistem bifuel. selanjutnya pada tahun 1997 pemerintah meluncurkan program “langit biru” untuk mendongkrak jumlah kendaraan yang menggunakan bahan bakar gas. konversi dari bbm ke bbg tidak hanya dilaksanakan di jakarta saja, tetapi juga di kota lainnya. pada tahun 1997-1998, di kota bandung juga pernah dilaksanakan uji coba konversi bbm ke bbg untuk transportasi. pada saat itu uji coba bbg diterapkan pada angkutan kota rute “margahayu-ledeng” sebanyak 35 unit. kit konverter yang digunakan berasal dari bantuan australia. selain mendapat bantuan dari australia, dana apbd (anggaran pendapatan dan belanja daerah) juga digunakan untuk pengadaan kit konverter yang dipasang pada kendaraan dinas pemerintah. total kendaraan angkutan kota dan mobil dinas yang menggunakan bbg sebanyak 80 unit. pada saat itu stasiun pengisian bahan bakar gas (spbg) berada di jalan katamso. karena di bandung tidak terdapat jaringan pipa gas maka untuk sistem supply gasnya menggunakan sistem container tank. dalam kurun waktu dari tahun 1988-2000 populasi kendaraan berbahan bakar gas terus meningkat, tetapi sejak tahun 2001 jumlahnya mulai menurun dan pada tahun 2004 diperkirakan hanya ada 500 unit kendaraan yang menggunakan bbg. untuk itu sejak tahun 2007, pemerintah mulai menggalakan lagi konversi bbm ke bbg pada kendaraan dengan memberikan bantuan kit konverter untuk taksi, angkutan kota dan bajaj di jakarta. di surabaya juga mulai dikembangkan konversi bbm ke bbg untuk kendaraan, tetapi berbeda dengan kota-kota lainnya di surabaya kit konverter yang digunakan bukan berasal dari bantuan pemerintah melainkan pihak swasta yang memberikan bantuan kredit kepada supir taksi. hal ini dapat berjalan karena masyarakat di sana sudah mengerti manfaat yang akan didapat dengan mengkonversi kendaraannya. sejak tahun 2007, pemerintah setiap tahun memberikan bantuan kit konverter untuk daerah-daerah yang sudah siap untuk melaksanakan program konversi bbm ke bbg pada kendaraan. perkembangan jumlah peralatan konversi bahan bakar gas dari tahun ke tahun dapat dilihat pada tabel 1 berikut ini. tabel 1. jumlah peralatan konversi di indonesia. �o. tahun kota jumlah konverter kits 1. 1988 jakarta 500 2. 1990 jakarta 90 3. 1997 bandung 80 4. 2007 jakarta 1.755 5. 2007 surabaya 500 6. 2008 jakarta 840 7. 2009 bogor 1.001 8. 2009 palembang 666 9. 2010 surabaya 500 b. dampak konversi dari bbm ke bbg pemakaian bahan bakar gas pada kendaraan akan berdampak positif. beberapa dampak tersebut dijelaskan seperti berikut. 1) mengurangi pemakaian bbm hal ini berarti mengurangi subsidi dan mengurangi impor minyak. hal tersebut dapat dihitung dan diformulasikan seperti di bawah ini. �� = � ��� � ∗ �� ∗ � (1) � = � ��� � ∗ � ∗ � (2) �� = �� ∗ �� (3) � = � ∗ � (4) �� = �� ∗ �� (5) �� = �� − � (6) � = �� − � (7) pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat (vita s, agus h, ridwan as, hendri ms, estiko r, a hapid) pp. 43-52 46 � = ��� − ����� ∗ �� (8) � = ��� + � � − � (9) keterangan: b = keuntungan g1 = penggunaan bbm pertahun g2 = penggunaan bbg pertahun h1 = harga bbm h2 = harga bbg h3 = harga bbm non subsidi h4 = harga kit konverter i = investasi jn = jumlah kendaraan roda 4 pada tahun ke-n j2 = jumlah hari dalam 1 tahun k1 = konsumsi bbm per hari k2 = konsumsi bbg per hari n = 1, …., 5 p1 = pengeluaran bbm p2 = pengeluaran bbg p3 = pengeluaran bbm non subsidi s1 = penghematan bahan bakar s2 = penghematan subsidi 2) mengurangi pencemaran lingkungan dengan menggunakan bbg maka emisi gas buang yang dihasilkan sangat kecil. apabila semua kendaraan yang menggunakan bbm di daerah berpotensi di jawa barat tersebut menghasilkan emisi 5,16 juta ton co2, maka emisi co2 akan berkurang sebesar 1,8 juta ton bila semua kendaraan tersebut dikonversi ke bbg. nilai emisi co2 di atas, dapat dihitung dan diformulasikan sebagai berikut : �� = ��� ∗ � ��� � ∗ �� ∗ � (10) keterangan : em = emisi j3 = jarak tempuh perhari vem = variabel emisi co2, co, nox, hc, dan partikel yang digunakan sebagai variabel pengurang emisi. dari perhitungan emisi bisa dikonversi ke cdm yang diformulasikan sebagai berikut: � ! = " ���###$ ∗ $ 10 (11) 3) menambah peluang usaha keberhasilan program ini berpotensi untuk meningkatkan peluang usaha dari industri hilir sampai ke industri hulu serta industri kit konverter itu sendiri, sehingga dapat meningkatkan lapangan kerja di berbagai sektor. 4) bagi pengguna �gv (�atural gas vehicle) dengan menggunakan bbg maka pengguna �gv dapat menghemat biaya operasional dan biaya perawatan karena harga bbg yang lebih murah dibandingkan dengan bbm. iv. hasil da� pembahasa� pembahasan makalah ini meliputi kendala yang dihadapi selama ini, daerah-daerah di jawa barat yang berpotensi dan keuntungan yang akan diperoleh. a. kendala program konversi hingga saat ini, pelaksanaan program konversi bbm ke bbg untuk kendaraan kurang berhasil dilihat dari jumlahnya yang kurang dari 5000 unit kendaraan berbahan bakar gas atau �gv. hal ini disebabkan beberapa kendala seperti berikut. 1) pasokan gas meskipun sumber gas di indonesia masih sangat banyak, namun pada kenyataannya quota gas untuk transportasi tidak ada. dari data yang ada, gas yang dialokasikan untuk dalam negeri telah habis digunakan oleh industri dan pembangkit listrik. pembangkit listrikpun masih kekurangan pasokan gas. apalagi gas untuk transportasi yang nota bene nilai kontraknya tidak menentu. untuk itulah diperlukan adanya jaminan quota gas untuk transportasi oleh pemerintah. 2) harga gas di jakarta terdapat dua jenis harga gas untuk kendaraan dalam hal ini c�g (compressed �atural gas). harga gas pertamina rp. 2.562/lsp atau liter setara premium sedangkan harga gas pgn (perusahaan gas negara) adalah rp. 3.600/lsp. karena perbedaan harga ini, maka spbg yang menjual gas lebih mahal kekurangan konsumen yang diakibatkan konsumennya beralih ke spbg yang menjual gas lebih murah. hal ini berakibat buruk karena terjadi antrian panjang dan spbg harus beroperasi terus menerus, sehingga perawatannya terabaikan. 3) spbg spbg yang ada selama ini sangat sedikit, dimana jakarta memiliki jumlah kendaraan berbahan bakar gas yang tidak sebanding dengan pertumbuhan pembangunan spbg, sehingga terjadi antrian yang cukup panjang pada saat pengisian bbg. hal ini mengakibatkan banyak kendaraan yang tadinya menggunakan bbg jadi beralih kembali menggunakan bbm karena enggan mengantri. journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 47 4) kit konverter kit konverter yang digunakan di indonesia saat ini berasal dari berbagai negara, seperti argentina, cina dan india. spare part atau suku cadang untuk peralatan konversi tersebut tidak tersedia di indonesia. jika ingin membelinya harus dalam jumlah besar dan waktu yang diperlukan untuk pengiriman juga lama. akibatnya kendaraan yang mengalami kerusakan sangat sulit diperbaiki karena sulitnya pengadaan spare part dan pada akhirnya kendaraan tersebut kembali lagi menggunakan bbm. 5) standar di indonesia standar yang digunakan untuk peralatan konversi bahan bakar gas (c�g) pada kendaraan adalah sni 7407 : 2009 [4]. standar ini mengacu pada beberapa standar dari luar negeri seperti as/nz 2739 : 2009 [5], iso 15500 : 2001 [6], dan sebagainya. namun butirbutir yang diacu pada sni tidak selengkap yang ada pada standar-standar tersebut, sehingga sni masih belum dapat dijadikan sebagai patokan. contohnya adalah pada sni ada bagian yang membahas mengenai instalasi, tetapi pada kenyataannya di lapangan para installer merakit peralatan konversi tersebut mengikuti panduan dari vendornya masing-masing tergantung merek peralatan konversinya. sehingga tata letak peralatan konversi pada kendaraan satu dengan yang lainnya berbeda-beda tergantung dari vendor dan luasnya ruang yang ada pada kendaraan. 6) pengujian selama ini di indonesia tidak ada suatu lembaga atau badan yang menguji peralatan konversi, yang ada hanya pengujian pada tabung yang dilakukan oleh departemen tenaga kerja. sebelum digunakan pada kendaraan, peralatan konversi yang diimpor harus diuji terlebih dahulu. sehingga dapat diketahui kelayakan penggunaan peralatan tersebut. 7) monitoring evaluasi sejak dicetuskannya program konversi bbm ke bbg pada kendaraan pada tahun 1988 hingga saat ini belum dilakukan monitoring dan evaluasi pada kendaraan yang menggunakan bbg, sehingga mengalami kesulitan untuk mendapatkan data populasi kendaraan. 8) cdm salah satu manfaat dari konversi bbm ke bbg pada kendaraan adalah pengurangan emisi. pengurangan emisi yang diperoleh dapat di konversi ke cdm (clean development mechanism), sehingga 1 ton co2 yang dikurangi dapat menghasilkan $10. pengurangan emisi co2 ini dijual dalam bentuk certified emission reduction (cer) ke negara-negara maju yang paling banyak menghasilkan emisi co2. b. daerah potensial program konversi pulau jawa bagian utara dari cilegon sampai surabaya sudah memiliki jaringan pipa gas yang saling terhubung. jaringan pipa gas tersebut dapat dilihat seperti pada gambar 1 di bawah ini. gambar 1. jaringan pipa gas di jawa barat [7]. pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat (vita s, agus h, ridwan as, hendri ms, estiko r, a hapid) pp. 43-52 48 jawa barat telah memiliki jaringan pipa gas dari bekasi sampai cirebon, sehingga untuk wilayah tersebut sangat berpotensi untuk dilaksanakannya program konversi bbm ke bbg ini. tabel 2 menunjukkan jumlah kendaraan di kabupaten/kota di jawa barat yang paling berpotensi untuk dilaksanakannya program ini. tabel 2. jumlah kendaraan. kabupaten dan kota roda 4 umum bukan umum dinas depok 15.594 55.056 835 cibinong 12.120 56.510 1.028 bogor 6.038 51.623 736 bekasi 16.973 155.637 1.253 cikarang 7.107 73.082 656 karawang 4.354 26.102 776 purwakarta 2.312 8.869 365 cirebon 5.144 27.701 445 bandung 12.577 332.196 3.417 total 82.219 786.776 9.511 tabel 2 adalah data kendaraan bermotor roda 4 per 30 juni 2010 dari dinas pendapatan daerah jawa barat di beberapa kabupaten/kota di propinsi jawa barat. tabel tersebut menunjukkan total kendaraan roda 4 yang mencakup kendaraan umum, kendaraan bukan umum, dan kendaraan dinas mencapai angka sebesar 878.505 unit kendaraan. dari tabel 2 juga dapat dilihat bahwa dari segi jumlah kendaraan roda 4, kabupaten/kota bandung, bekasi, depok dan cibinong sangat berpotensi untuk melaksanakan konversi bbm ke bbg. selain itu di kabupaten/kota tersebut juga sudah mempunyai jaringan pipa gas, kecuali bandung. dari data pada tabel 2, dapat disimulasikan perhitungan potensi untuk daerah-daerah tersebut. dengan asumsi pada tahun pertama sebesar 10% dari jumlah kendaraan yang dikonversi dan kemudian kenaikan konversi pertahunnya sebesar 5%, sehingga pada tahun 2015 kendaraan berbahan bakar gas atau �atural gas vehicle (�gv) akan mencapai 263.554 seperti yang terdapat pada tabel 3 berikut ini. tabel 3. kenaikan konversi per tahun. kabupaten dan kota 2011 2012 2013 2014 2015 depok 7.149 10.722 14.297 17.872 21.446 cibinong 6.966 10.449 13.932 17.415 20.897 bogor 5.840 8.759 11.680 14.600 17.519 bekasi 17.386 26.080 34.772 43.465 52.159 cikarang 8.085 12.126 16.168 20.212 24.254 karawang 3.123 4.684 6.246 7.809 9.370 purwakarta 1.155 1.732 2.309 2.886 3.465 cirebon 3.329 4.994 6.658 8.322 9.987 bandung 34.820 52.229 69.637 87.047 104.457 total 87.853 131.775 175.699 219.628 263.554 dari tabel 3 di atas, dapat dilihat bahwa total kenaikan �atural gas vehicle selama lima tahun sebesar 30% dari total jumlah kendaraan roda 4 pada tahun 2010. selanjutnya dari tabel 3 dapat disimulasikan banyaknya stasiun pengisian bahan bakar gas yang diperlukan di setiap kabupaten/kota. jumlah tersebut adalah jumlah minimum yang diharapakan dapat melayani semua �gv yang ada di sana. dengan asumsi satu stasiun pengisian bahan bakar gas dapat melayani 750 ngv, maka jumlah pembangunan stasiun pengisian bahan bakar gas di tiap kabupaten dan kota dari tahun 2011 sampai tahun 2015 dapat dilihat pada tabel 4 berikut ini. tabel 4. jumlah spbg. kabupaten dan kota 2011 2012 2013 2014 2015 depok 10 14 19 24 29 cibinong 9 14 19 23 28 bogor 8 12 16 19 23 bekasi 23 35 46 58 70 cikarang 11 15 22 27 32 karawang 4 6 8 10 12 purwakarta 2 2 3 4 5 cirebon 4 7 9 11 13 bandung 46 70 93 116 139 total 117 175 235 292 351 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 49 tabel 4 menunjukkan bahwa daerah bandung memerlukan 46 spbg pada tahun pertama, dan pada tahun ke-2 diperlukan 70 spbg. tiap tahun kebutuhan spbg makin meningkat sampai pada tahun ke-5 diperlukan 139 spbg. secara keseluruhan minimal diperlukan 351 spbg di jawa barat untuk memenuhi kebutuhan suplai gas bagi �atural gas vehicle. hal ini terjadi apabila konversi setiap tahunnya berjalan dengan lancar. kebutuhan gas selama 5 tahun di kabupaten/kota tersebut dapat disimulasikan dengan menggunakan asumsi bahwa penggunaan gas adalah 10 lsp (liter setara premium) per hari, maka besarnya kebutuhan gas di tiap kabupaten/kota dapat dilihat pada tabel 5 di bawah ini. tabel 5. kebutuhan gas. kabupaten dan kota volume gas (lsp) depok 250.201.000 cibinong 243.806.500 bogor 204.393.000 bekasi 608.517.000 cikarang 282.957.500 karawang 109.312.000 purwakarta 40.414.500 cirebon 116.515.000 bandung 1.218.665.000 total selama 5 tahun 3.074.781.500 berdasarkan tabel 5, pemerintah harus memenuhi kebutuhan minimal gas selama 5 tahun sebesar 3,1 milyar lsp. perhitungan ini dengan asumsi minimal penggunaan gas tiap kendaraan per harinya adalah 10 lsp. c. proyeksi keuntungan program konversi berdasarkan jumlah kendaraan berbahan bakar gas seperti yang terdapat pada tabel 3, dapat disimulasikan nilai potensi keuntungan yang akan didapat dengan asumsi harga bbg rp. 2.562 dan harga bbm bersubsidi rp. 4.500 sedangkan harga bbm non subsidi rp. 6.500 serta harga kit konverter rp. 12.000.000,per set. sebagai contoh kabupaten/kota yang sangat berpotensi salah satunya adalah bandung. untuk menghitung pengeluaran bbm, bbg, dan sebagainya terlebih dahulu dilakukan perhitungan penggunaan bbm dan bbg per tahun dengan menggunakan persamaan (1) pada tahun pertama (2011) yaitu dengan persamaan �� = � ��� � ∗ �� ∗ � maka didapat penggunaan bbm sebesar 121.870.000 liter, dan dengan menggunakan persamaan (2) � = � ��� � ∗ � ∗ � maka didapat besarnya penggunaan bbg sebesar 121.870.000 liter. dengan menggunakan persamaan yang sama dapat dihitung penggunaan bbm dan bbg pada tahun ke-2 sampai ke-5. total penggunaan bbm dan bbg selama 4 tahun sebesar 1.096.795.000 liter. untuk menghitung pengeluaran bbm, bbg, bbm non subsidi dan sebagainya dengan menggunakan persamaan (3) sampai (9) di atas maka pada tahun pertama (2011) untuk menghitung pengeluaran bbm yaitu dengan persamaan �� = �� ∗ �� maka hasil yang di dapat untuk pengeluaran bbm adalah rp. 548.415.000.000. untuk menghitung pengeluaran bbg yaitu dengan persamaan p2 = g2 * h2 maka hasilnya sebesar rp. 312.230.940.000. dengan menggunakan persamaan (5) yaitu p3 = g1 * h3 maka hasil yang didapat untuk pengeluaran bbm non subsidi sebesar rp. 792.155.000.000. dihitung penghematan bahan bakar dengan menggunakan persamaan (6) yaitu s1 = p1 – p2 maka hasil sebesar rp. 236.184.060.000. dengan menggunakan persamaan (7) yaitu s2 = p3 – p2 maka hasil yang didapat untuk penghematan subsidi sebesar rp. 479.924.060.000. investasi yang dikeluarkan pada tahun pertama dapat dihitung dengan menggunakan persamaan (8) yaitu �= ��� − ����� ∗ �� maka besarnya investasi adalah rp. 417.840.000.000. nilai keuntungan yang di dapat menggunakan persamaan (9) yaitu b = (s1+s2) – i maka besarnya keuntungan adalah rp. 298.268.120.000. untuk tahun ke-2 sampai ke-5 dapat dihitung dengan menggunakan persamaan yang sama, sehingga total selama 4 tahun untuk pengeluaran bbm sebesar rp. 935.577.500.000, pengeluaran bbg sebesar rp. 2.809.988.790.000, pengeluaran bbm non subsidi sebesar rp. 7.129.167.500.000, penghematan biaya bahan bakar sebesar rp. 2.125.588.710.000, penghematan subsidi sebesar rp. 4.319.178.710.000, investasi sebesar rp. 835.644.000.000, dan keuntungan yang didapat sebesar rp. 5.609.123.420.000. jadi selama 5 tahun dengan investasi sebesar 1,2 triliyun rupiah akan mendapatkan keuntungan sebesar 5.9 triliyun rupiah. keuntungan yang didapat berupa penghematan subsidi dan penghematan bahan bakar. untuk kabupaten/kota yang lainnya perhitungannya sama seperti bandung dan selama 5 tahun mendapatkan keuntungan seperti yang tertera pada tabel 6 di bawah ini. pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat (vita s, agus h, ridwan as, hendri ms, estiko r, a hapid) pp. 43-52 50 tabel 6. perhitungan keuntungan yang diperoleh. kabupaten dan kota total investasi (rp) total penghematan bahan bakar (rp) total penghematan subsidi (rp) total keuntungan (rp) depok 257.35.000.000 484.889.538.000 985.291.538.000 1.212.829.076.000 cibinong 250.764.000.000 472.496.997.000 960.109.997.000 1.181.842.994.000 bogor 210.228.000.000 396.113.634.000 804.899.634.000 990.785.268.000 bekasi 625.908.000.000 1.179.305.946.000 2.396.339.946.000 2.949.737.892.000 cikarang 291.048.000.000 548.371.635.000 1.114.286.635.000 1.371.610.270.000 karawang 112.440.000.000 211.846.656.000 430.470.656.000 529.877.312.000 purwakarta 41.580.000.000 78.323.301.000 159.152.301.000 195.895.602.000 cirebon 119.844.000.000 225.806.070.000 458.836.070.000 564.798.140.000 bandung 1.253.484.000.000 2.361.772.770.000 4.799.102.770.000 5.907.391.540.000 selain keuntungan dari segi penghematan subsidi, penghematan bahan bakar dan penghematan biaya operasional, manfaat lain dari konversi dari bbm ke bbg adalah pengurangan emisi. dari data pada tabel 3 dapat disimulasikan besarnya pengurangan emisi gas buang kendaraan selama 5 tahun dengan asumsi pengurangan emisi berdasarkan data success story dari pakistan yaitu pengurangan emisi co2 = 0,0001 kg/km, co = 0,00216 kg/km, nox = 0,00171 kg/km, hc = 0,000252 kg/km, dan partikel = 0,002142 kg/km. serta asumsi jarak tempuh 100 km/hari dan jumlah hari dalam 1 tahun adalah 350 hari. sebagai contoh, perhitungan emisi pada kabupaten/kota bandung, dengan menggunakan persamaan (10) dapat dihitung emisi pada tahun pertama (2011) untuk emisi co2 yaitu dengan persamaan ����( � = ����)*+� ∗ � �� � � ∗ �� ∗ � maka pengurangan co2 sebesar 121.870 kg. sementara untuk emisi co yaitu dengan persamaan ����(� = ����)*� ∗ � ��� � ∗ �� ∗ � maka diperoleh nilai pengurangan emisi co sebesar 2.632.392 kg. untuk emisi nox menggunakan persamaan ���,(-� = ����.*/� ∗ � ��� � ∗ �� ∗ � maka pengurangan emisi nox sebesar 2.083.977 kg. perhitungan emisi hc menggunakan persamaan ������ = ����0)� ∗ � ��� � ∗ �� ∗ � maka besarnya pengurangan emisi hc adalah 307.112 kg. dan untuk emisi partikel dengan persamaan ���12345678� = ����9:;< =>?� ∗ � ��� � ∗ �� ∗ � maka besarnya pengurangan emisi partikel adalah 2.610.455 kg. dengan menggunakan persamaan yang sama dapat dihitung pengurangan emisi pada tahun ke-2 sampai tahun ke-5. jadi total pengurangan emisi di bandung dari tahun 2012 sampai tahun 2015 mempunyai rincian sebagai berikut; untuk emisi co2 sebesar 1.096.795 kg, emisi co sebesar 23.690.772 kg, emisi �ox sebesar 18.755.195 kg, emisi hc sebesar 2.763.923 kg, dan emisi partikel sebesar 23.493.349 kg. selanjutnya perhitungan pengurangan emisi untuk kabupaten/kota yang lain menggunakan cara yang serupa seperti perhitungan di atas. total pengurangan emisi selama 5 tahun untuk setiap kabupaten/kota dapat dilihat pada tabel 7 di bawah ini. tabel 7. pengurangan emisi (kg) selama 5 tahun. kabupaten dan kota co2 co �ox hc partikel depok 250.201 5.404.342 4.278.437 630.507 5.359.305 cibinong 243.807 5.266.220 4.169.091 614.392 5.222.335 bogor 204.393 4.414.889 3.495.120 515.070 4.378.098 bekasi 608.517 13.143.967 10.405.641 1.533.463 13.034.434 cikarang 282.958 6.111.882 4.838.573 713.053 6.060.950 karawang 109.312 2.361.139 1.869.235 275.466 2.341.463 purwakarta 40.415 872.953 691.088 101.845 865.679 cirebon 116.515 2.516.724 1.992.407 293.618 2.495.751 bandung 1.218.665 26.323.164 20.839.172 3.071.036 26.103.804 total 3.074.783 66.415.280 52.578.764 7.748.450 65.861.819 journal of mechatronics, electrical power, and vehicular technology vol. 01, �o 2, 2010 iss� 2087-3379 51 dari data pada tabel 7 dapat dihitung besarnya cdm yang dihasilkan yaitu dengan pengurangan emisi 1 ton co2 akan menghasilkan $10. perhitungan cdm ini sesuai menggunakan persamaan (11) di atas. sebagai contoh kabupaten/kota bandung, pada tahun pertama (2011) cdm untuk co2 dengan persamaan cdm (co2) = (em(co2)/1000) * $ 10 menghasilkan $ 1.219. untuk co menggunakan persamaan cdm (co) = (em(co)/1000) * $ 10 menghasilkan $ 1.219 dan untuk hc menggunakan persamaan cdm (hc) = (em(hc)/1000) * $ 10 menghasilkan $ 3.071. sedangkan perhitungan cdm di bandung untuk tahun ke-2 sampai tahun ke-5 menggunakan perhitungan yang serupa seperti perhitungan di atas, sehingga total cdm selama 4 tahun yaitu untuk cdm (co2) sebesar $10.968, cdm (co) sebesar $236.908, dan cdm (hc) sebesar $27.639. perhitungan cdm di kabupaten/kota lainnya tertera pada tabel 8 di bawah ini. tabel 8. perhitungan cdm . kabupaten dan kota 2011 2012 2013 2014 2015 depok $ 6.285,40 $ 9.426,78 $ 12.569,92 $ 15.713,06 $ 18.855,32 cibinong $ 6.124,51 $ 9.186,76 $ 12.249,01 $ 15.311,27 $ 18.372,64 bogor $ 5.134,53 $ 7.700,91 $ 10.269,06 $ 12.836,32 $ 15.402,70 bekasi $ 15.285,77 $ 22.929,54 $ 30.571,54 $ 38.214,43 $ 45.858,19 cikarang $ 7.108,33 $ 10.661,18 $ 14.214,91 $ 17.770,39 $ 21.324,12 karawang $ 2.745,74 $ 4.118,17 $ 5.491,48 $ 6.865,67 $ 8.238,10 purwakarta $ 1.015,48 $ 1.522,77 $ 2.030,07 $ 2.537,37 $ 3.046,43 cirebon $ 2.926.86 $ 4.390,72 $ 5.853,71 $ 7.316,70 $ 8.780,57 bandung $ 30.613,74 $ 45.919,74 $ 61.224,85 $ 76.531,72 $ 91.838,59 total $ 77.240,36 $ 115.856,57 $ 154.474,55 $ 193.096,93 $ 231.716,66 perhitungan cdm dari tabel 8 berdasarkan hasil perhitungan co2, co dan hc yang dikonversi ke cdm. total keseluruhan cdm yang dihasilkan selama 5 tahun sebesar us$ 772.385. cdm ini dapat dijual dalam bentuk cer ke negara-negara dunia ketiga yang mempunyai tingkat polusi udara yang tinggi seperti pakistan iran, atau india. selain itu, cer dapat dijual ke negara-negara industri maju seperti amerika, kanada, atau china. v. kesimpula� da� sara� dari hasil analisa dan perhitungan yang telah dilakukan, dapat diambil beberapa kesimpulan sebagai berikut: 1. konversi dari bbm ke bbg pada kendaraan mempunyai banyak manfaat. salah satunya yaitu pengurangan penggunaan bbm yang berarti pengurangan import minyak. hal ini dapat membantu pemerintah dalam mengurangi subsidi bbm. selain itu, program konversi ini mengurangi emisi gas buang pada kendaraan bermotor. 2. kabupaten/kota di propinsi jawa barat yang paling berpotensi berdasarkan banyaknya jumlah kendaraan dan telah adanya jaringan pipa gas adalah depok, cibinong, bogor, dan bekasi. sementara bandung sangat berpotensi karena banyaknya jumlah kendaraan meskipun belum ada jaringan pipa gasnya. 3. jumlah kendaraan roda 4 di kabupaten/kota yang berpotensi tersebut sebanyak 878.505 unit dan pada tahun pertama kendaraan tersebut dikonversi ke bbg sebanyak 10% dan kenaikan setiap tahunnya sebesar 5%. total kendaraan yang dikonversi selama lima tahun sebanyak 263.554 unit. 4. dengan banyaknya populasi kendaraan yang dikonversi tersebut, maka spbg yang harus disediakan selama 5 tahun adalah sebanyak 351 spbg. total tersebut didapat berdasarkan perhitungan 1 spbg yang dapat melayani 750 kendaraan. 5. dengan investasi sebesar 3,16 triliyun rupiah dapat diperoleh keuntungan sebesar 14,9 triliun rupiah yang berupa penghematan subsidi dan penghematan bahan bakar. 6. melalui pengurangan emisi co2, co dan hc selama 5 tahun sebesar 3.074,8 ton akan menghasilkan clean development mechanism (cdm) sebesar us$ 772.385. 7. bila program konversi ini berjalan sesuai rencana maka industri peralatan konversi di dalam negeri juga akan berkembang pesat, dan secara otomatis jumlah lapangan kerja juga akan meningkat pula. pengurangan subsidi bbm dan polusi udara melalui kebijakan program konversi dari bbm ke bbg untuk kendaraan di propinsi jawa barat (vita s, agus h, ridwan as, hendri ms, estiko r, a hapid) pp. 43-52 52 daftar pustaka [1] kantor menko perekonomian, “kajian pembiayaan investasi transportasi perkotaan dengan skema debt-for-nature swap”, 2004. [2] subdit pemantauan pencemaran. (2009). uji b dalam darah anak-anak sekolah dasar di bandung pada tahun 2008. [online]. available: http://www.bplhdjabar.go.id/index.php/bid ang-pengendalian/subid-pemantauanpencemaran/247-uji-pb-dalam-darah-anakanak-sekolah-dasar-di-bandung-padatahun-2008, diakses 8 juli 2010. [3] norris, j. et al, “light goods vehicle co2 emission study: task report for task 5 assesment of the potential for co2 emissions reduction”, the department for transport harwell didcot. 2009. [4] standar nasional indonesia. (2009) peralatan konversi bahan bakar gas bumi bertekanan (compressed �atural gas/c�g) pada kendaraan bermotor. [online]. available: http://websisni.bsn.go.id/index.php/sni_ma in/sni/cari_simple/18/, diakses 17 maret 2010. [5] australian new zealand standard, “natural gas (ng) fuel system for vehicle engines”, fifth edition ed. sydney: standard australia and standard new zealand, 2009. [6] international standard. (2008, february) ngv shop forums. [online]. available: http://ngvshop.com/board/index.php?boa rd=6.0, diakses 19 maret 2010. [7] kementrian esdm, bpmigas. [online]. available: www.bpmigas.com, diakses 20 agustus 2010. mev journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2022.v13.125-136 2088-6985 / 2087-3379 ©2022 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: s. mejiartono et al., “numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application,” journal of mechatronics, electrical power, and vehicular technology, vol. 13, no. 2, pp. 125-136, dec. 2022. numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application sarid mejiartono a, *, muhammad fathul hikmawan b, aditya sukma nugraha b, c a faculty of mechanical and aerospace engineering, bandung institute of technology jl. ganesa no.10, lb. siliwangi, bandung, 40132, indonesia b research center for smart mechatronics, national research and innovation agency (brin) kawasan bandung cisitu, jl. sangkuriang, dago, coblong, bandung, 40135, indonesia c department of mechanical engineering, national taiwan university of science and technology taipei, 10672, taiwan received 18 july 2022; 1st revision 11 october 2022; 2nd revision 29 october 2022; 3rd revision 12 november 2022; 4th revision 18 november 2022; accepted 21 november 2022; published online 29 december 2022 abstract the use of a pump as opposed to a turbine/pump as turbine (pat) for off-grid electrification applications is one of the important ways to be considered in efforts to equalize electrical energy in indonesia. the main problem in pat applications is how to predict pump performance if applied as a turbine to find out its best characteristics and efficiency points. this study discusses a method to find pump performance specifications when using a pump with a mixed flow type as a turbine for micro hydro power plants. the numerical method by utilizing computational fluid dynamics (cfd) based software simulations that have been proven to be accurate according to previous studies was selected for use in obtaining predictions of the pump characteristics as turbines. then the pat characteristics of the cfd simulation results are validated by conducting direct testing. the results of the cfd numerical simulation using ansys fluent software show the performance curve of a mixed flow pump operated as a turbine at various rotating speeds. the highest efficiency for each rotating speed ranges from 35-40 %. the test results directly show the pat characteristics, that the performance range is close to the numerical simulation results with a difference of 10 %. copyright ©2022 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: pump as turbine (pat); micro hydro power plant; computational fluid dynamics (cfd). i. introduction the improvement and equitable distribution of the economic development of each country will not be able to be realized without building its energy availability. electrical energy is one of the most vital and necessary forms of energy in society today. the need for electrical energy in each region will inevitably continue to be needed along with the growth of the needs of its population. study [1] stated that indonesia's energy needs in 2025 are 170.8, 154.7, and 150.1 mtoe, respectively, based on energy mix (em), sustainable development (sd), and low carbon (lc) scenarios. many studies are also carried out to predict the addition of energy needs in every region. in [2] has conducted research on the prediction of electricity demand by utilizing artificial neural networks (ann). in indonesia, research on predicting energy consumption has been conducted by [3][4] recently. on the other hand, the problem of the availability of fossil energy continues to decrease and certainly cannot be renewed anymore. one of the keys to answering all these problems is renewable energy. various studies continue to be carried out in developing technology to be able to absorb and utilize renewable energy as much as possible. the renewable energy potentials owned by each region continue to be sought and studied to be utilized as well as possible. indonesia, with its location and geographical conditions, has the potential for very abundant renewable energy resources, one of which is water resources. with its heavy rainfall and topographical conditions, indonesia was awarded more than 5,000 watersheds. the utilization of these water resources can be done * corresponding author. tel: +62-81275730779, +62-85643591995 e-mail: sarid.mejiartono@gmail.com https://dx.doi.org/10.14203/j.mev.2022.v13.125-136 https://dx.doi.org/10.14203/j.mev.2022.v13.125-136 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2022.v13.125-136 https://dx.doi.org/10.14203/j.mev.2022.v13.125-136 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.125-136&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1088/1755-1315/753/1/012038 https://doi.org/10.1088/1755-1315/753/1/012038 https://doi.org/10.1088/1755-1315/753/1/012038 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 126 by building hydroelectric power plants and micro hydro power plants to take advantage of small potentials in remote areas. various studies on potentials in watersheds in indonesia have been carried out, some of which have been carried out by [5][6][7]. the area, location, and geographical conditions of indonesia, on the other hand, are one of the factors inhibiting the equitable fulfillment of electrical energy throughout its territory, apart from the factor of the amount of energy that can be produced by electricity companies. the micro-hydroelectric power plant scheme by utilizing pumps as turbines (pat) for remote off-grid electrification can be used as a way to equalize electrical energy in indonesia. the pat system for micro hydro power plants in remote areas is very promising, especially because it is very economical. several studies on the technoeconomical, costs, and advantages of pat applications for micro hydro power plants have been carried out, among others by [8][9]. in addition, pat has various other advantages, including the ease of availability, availability for various heads and flows, simple construction, and it also allows one to significantly reduce design and maintenance costs compared to traditional turbine applications. in general, pat has a lower efficiency when compared to conventional water turbines. however, in the application of pat for micro hydro power plants in remote areas, efficiency is not the main criterion in its selection. the efficiency problem, in this case, can be solved slightly by means of operating the pat around its maximum efficiency point. however, the main and most challenging problem in pat applications is how to predict performance at its best efficiency point. several studies have been conducted related to efforts to obtain predictions of pump performance when used as a turbine. research conducted by [10] pays attention to the benefits of computational fluid dynamics (cfd) for studying pat. [11] presents a detailed analysis of three-dimensional flow and predicts pump as turbine (pat) performance. the speed triangle in turbine mode is calculated analytically and evaluated numerically by cfd. the rate characteristics of the internal flow have also been investigated by [12] performed on conventional centrifugal pumps using cfd software. in his research, the sst k-ω turbulence model was used. that is a combination of the standard k-ε model and the standard k-ω model. the advantage of using this combined model is that it can capture small flows in viscous layers with the advantages of the standard k-ε model in the region of the persistent turbulent core [13] has conducted an experimental study to determine the effect of viscosity on the performance of the pat system. prediction of pat performance when working at different rotational speeds is carried out by [14]. research studying irreversible energy losses in pat was introduced by [15] based on the point of view of the second law of thermodynamics as well as the theory of entropy generation [16]. it has also introduced a method for predicting pat performance based on theory and numerically in a single stage centrifugal pump operated as a turbine. the surface roughness effect of the impeller/pump blade used as a turbine has been studied by [17]. another study introducing a new theoretical method for predicting the best efficiency points of pat has been worked out by [18], where the theory is based on the principle of matching impeller-volute, which is then validated using three centrifugal pumps with specific speeds. investigations into centrifugal pump experiments used as turbines (pat) also have been conducted by [19][20]. the results of such experiments can be known and shown that the pump operates at a higher head and discharge value if it is synchronized in turbine mode and the best efficiency point (bep) is lower than bep in pump mode. studies to increase the effectiveness of pat applications, among others, have been carried out by [21][22]. besides being able to be applied to micro hydro power plants, this pat system is also widely used in energy recovery systems. the pat is attached to the water distribution channel system to function as a water pressure reduction in the water line as well as a producer of electrical energy. several pat studies for applications on these water distribution line systems have been conducted by [23][24][25]. most of the literature that discusses the prediction of pumps applied as turbines uses pumps with a centrifugal type. it is still rare to investigate mixed flow type pumps to be applied as pat. this article discusses one way to find pump performance specifications when it is used as a turbine for micro hydro power plants using a pump with a mixed flow type. the numerical method by utilizing computational fluid dynamics (cfd) based software simulations that have been proven to be accurate according to previous studies was selected for use in obtaining predictions of pump characteristics as turbines. then the pat characteristics of the cfd simulation results are validated by conducting direct testing. ii. materials and methods backflow pump testing to operate the pump as a turbine was carried out to test the results obtained from numerical simulations. then, the data obtained by simulation and testing are compared to obtain validation of the analysis results. the mixed flow pump used as the object of this pat research is the pn-indra surabaja type sb60-10 pump. this pump is an inventory of the fluid machinery laboratory, ftmd itb. the physical form of the pump is shown in figure 1. in modeling, the rear pump housing is called discharge and the front pump housing is called (a) (b) (c) figure 1. (a) front pump housing; (b) rear pump housing; (c) impeller https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.3390/en14206456 https://doi.org/10.3390/en14206456 https://doi.org/10.1016/j.apenergy.2019.03.018 https://doi.org/10.1016/j.apenergy.2019.03.018 https://doi.org/10.1016/j.apenergy.2019.03.018 https://doi.org/10.3390/w13152134 https://doi.org/10.3390/w13152134 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2016.03.092 https://doi.org/10.1016/j.renene.2016.03.092 https://doi.org/10.1016/j.renene.2018.04.084 https://doi.org/10.1016/j.renene.2018.04.084 https://doi.org/10.1088/1755-1315/15/4/042023 https://doi.org/10.1088/1755-1315/15/4/042023 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2012.06.002 https://doi.org/10.1016/j.renene.2012.06.002 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w12040958 https://doi.org/10.1016/j.egypro.2016.11.163 https://doi.org/10.1016/j.egypro.2016.11.163 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 127 suction. in the pump catalog, there is pump specification data, including discharge, head, power, and rotational speed, as shown in table 1. the next section is a simulation process using ansys fluent software with a choice of fluid flow (fluent) mode. the simulation process consists of four stages, namely geometry, mesh, setup, and solution & result. a. geometry modeling fluid through the pump is modeled using the help of solidworks software, then imported into ansys software for further simulation using fluid flow (fluent). the pump model based on the modeling results is shown in figure 2. figure 2(a) is the isometric view of the pump model and figure 2(b) is the piece/cutting side view. figure 3 is the boundary condition for each computational model of the components. figure 3(a) is the inlet fluid flow, figure 3(b) is the outlet, and figure 3(c) is the casing/wall. the blade boundary condition is shown in figure 3(d), and the hub is shown in figure 3(e). b. meshing process at the meshing stage using tetrahedron mesh, the volume of fluid is divided into smaller elements. in the case of very complex geometries, these tetrahedral meshes are easy to generate and thus save a lot of time [26]. because of that consideration, this type of mesh was chosen in this case. the meshing process is carried out using the default condition as the initial reference to produce mesh criteria that are considered in accordance with the physical condition of the model. it is simulated using a fluent solver with two criteria, namely skewness and minimum orthogonal quality. the average skewness score is 0.236 and the minimum qualifies mesh orthogonal quality is above 0.1, which is 0.17819. the meshing results of the computational pump model are shown in figure 4. the mesh statistics of the model are shown in table 2. the mesh element in table 2 is 4,683,249. even though it is quite good in terms of skewness and orthogonality, this number of mesh elements needs a validation process in the next process with a mesh independence test so that the mesh elements are considered representative of the analysis process. table 1. mixed flow pump specification data material amount specification debit 150 m3/hour head 10 m power 7.46 kw rotational speed 2,000 rpm table 2. mesh statistics statistic value node 2,451,941 elements 4,683,249 mesh metric orthogonal quality minimum 0.20235 maximum 0.99998 average 0.91322 standard deviation 8.6438e-002 (a) (b) figure 2. (a) full view fluid volume; (b) piece (a) (b) (c) (d) (e) figure 3. named selection: (a) inlet; (b) outlet; (c) casing; (d) blade; (e) hub s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 128 c. simulation settings the setup stage is intended to make the initial setup before simulating using fluent. in the processing options section, parallel (local machine) is selected and replaces the values contained in the solver processes column according to the capabilities of the computer used. the arrangement is carried out in several categories contained in the solution stage consisting of selecting a scale into millimeters (mm), a steady condition, the gravity of -9.81 in columns y, angularvelocity is changed to rpm, and the solver type is selected to pressure-based. on the models menu, the viscous mode is selected. the models used are komega sst, production limiter & constants model value for alpha*_inf = 1, alpha_inf = 0.52, beta*_inf = 0.09 and a1 = 0.31. the k-omega sst model is widely used in solving complex turbo engine problems and there are many walls where a boundary layer is formed due to the flow of fluid through it. the material used as the working fluid is water (waterliquid <h20>) with a constant density of 998.2 kg.m-3 & a viscosity constant of 0.001003 kg.m-3. in the cell zone conditions menu, the parameters that are set are the material and movement behavior of each body. for discharge and suction, the material is arranged into water. as for the impeller, in addition to adjusting the type of material to water, the rotational motion mode can be adjusted by selecting the frame motion option. the rotational motion of the impeller has a positive x rotary axis vector, so column x is assigned a value of 1 and the other axis is assigned a value of 0. the size of the impeller rotational speed is set in the rotational velocity section of the speed column (rpm) of 2,000 rpm. the relative specification chosen is absolute so that the reference of the rotary axis is a global coordinate defined in the geometry created. meanwhile, in the boundary conditions menu, the boundary conditions of the pump model are regulated as simulated as turbines. setting boundary conditions including movement behavior on the walls of the blade and hub, as well as the pressure on the inlet and outlet sides of the pump. blades and hubs are defined as walls that move with a rotating motion relative to the rotation of the impeller on the x-axis with a relative velocity magnitude of 0 rpm. it shows that the direction and rotational speed of the blade wall and hub are the same as the impeller, which is the reference of the two parts, so the moving wall motion is chosen, motion is chosen relative to adjacent cell zone-rotational, and the shear condition is chosen no slip with 0.5 wall roughness-constant. the pressure on the outlet side is set by 0 pa (gauge) by considering the outlet side as a reference to the size of the pump moved head. for pressure regulation on the inlet side, the pressure column is set as large as the head moved by the pump. in addition to the magnitude of the pressure value, the setting is also carried out by selecting the k and omega modes, where k is the kinetic energy of turbulence, ω = specific dissipation rate and i = intensity of turbulence. the values entered for turbulent kinetic energy and specific dissipation rate use equation (1) and equation (2), 𝐾 = 3 2 �𝑉𝑎𝑎𝑎𝐼� 2 (1) 𝜔 = 𝐾 0,5 𝐶𝜇 0,250,09𝐷 (2) cµ expresses a constant empirically whose value is 0.09. using preliminary guesses of the average velocity on the inlet and outlet sides, the calculation results for turbulent kinetic energy were obtained by 0.002155 m 2.s-2, and the specific dissipation rate was obtained by 26.04661.s-2. in the turbo topology menu, the definition is carried out on a surface named at the geometry stage discussed earlier. in solution initialization, the mode chosen is standard initialization, with compute from the selected side inlet and reference frame is absolute. then, the gauge pressure is filled with the inlet side pressure to be simulated of 97923.42 and y-velocity is filled with the initial guess of the flow speed on the inlet side by -4. after all the parameters in the input, then carry out the simulation running process by setting the number of iterations so that they converge. d. installation experiment test to assist in data collection in testing mixed flow pumps as turbines, several supporting equipment is needed, namely pumps, ac motors, gate valves, butterfly valves, flow meters, torsions, manometers, and tachometers. the test installation begins with drawing up a pump that will be used to drain the water in the pipeline and then flow into the pat system. the series of test benches in the test installation can be seen through the pid diagram in figure 5. in figure 6 of the pump installation arrangement, the pump shaft is connected to an ac motor or using a clutch. the suction pump is connected to the pipe until it is submerged in water, while the pump discharge part is connected to the gate valve, then the gate valve is connected to the reservoir using pipes and elbows. figure 4. meshing results s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 129 the arrangement of the pat installation starts from the reservoir, pipe, and elbow to connect the butterfly valve. then the butterfly valve is connected to the inlet side of the pump as turbine (pat) using pipes and elbows. on the pipe is placed a flow meter to measure the flow rate of water in the pipe. in the inlet pipe and pat outlet, a hole is attached to each tap and manometer. the torque meter is paired by means of being connected to the pat shaft. the arrangement of the pat installation is shown in figure 7. e. testing work steps the testing process begins with the position of the gate valve fully closed and the butterfly valve open. then, the ac motor is turned on to run the pump. after 10 seconds, the gate valve is slowly opened until the water can begin to flow to fill the reservoir. water will then flow past the butterfly valve to the inlet side of the pat and enters the pat, causing the pat to work and the pat shaft to rotate. the manometer will show the pressure difference readings of the inlet side and the pat outlet. the flow meter is turned on to a stable flow speed. the torque meter begins to have functioned until the rotating speed of the pat shaft is reduced to 800 rpm and 400 rpm. the data taken are the rotating speed of the pat shaft, the torque generated, the pressure difference of the inlet and outlet sides, and the speed of water flow in the pipeline. iii. results and discussions a. simulation results the iteration process of convergent immolation is achieved after the residual values of continuity, xy-z velocity, k, and omega have passed the specified error limit. the iteration data are in the form of torque as shown in table 3. from these data it can be seen that the total torque is -38.80641 nm with a total coefficient of -0.99503614. figure 5. test bench diagram figure 6. assembly of pump figure 7. assembly of pat s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 130 the iteration data in the form of the mass rate is shown in table 4. from the data in the table, it can be seen that there is no significant difference between the mass flow at the inlet and outlet, where the inlet is 74.07208 kg/s and the outlet is 74.27893 kg/s. the data that has been obtained is collected for each rotational speed. the simulations were performed at 400, 800, 1480, 1800, and 2000 rpm. however, the data shown in table form are only the turbine discharge, head, power, and efficiency at 400 and 800 rpm in table 5 and table 6. the data in the two tables are then loaded into a graph shown in figures 8-10. b. validation of numerical simulation results to prove that the simulation that has been carried out is valid, a mesh independency test process is carried out. in this process, the number of mesh elements is varied against a variable that will be taken as data, namely the mass rate of flow. the purpose of the mesh independency test is to see the number of elements that are considered representative for later use in the analysis process. the results of the mesh independency test are shown in table 7. it can be seen from the results of the mesh independency test that the more the number of mesh elements, the mass rate obtained will be smaller. at the change in the number of mesh elements of 4,683,249 to 5,428,728, it can be seen that the change in the mass rate is very small; the decrease is only 0.638 %. therefore, the number of mesh elements of 4,683,249 can be used for the numerical simulations. c. simulation result analysis any numerical simulation data that has been obtained can be processed into various points that can be arranged into regression curves that can describe the characteristics of pat. the curves of the pat numerical simulation results for various rotating speeds and performance parameters are shown in figures 8-10. figure 8 shows the curve graph of power vs. discharge. it can be seen that pat has demonstrated characteristics that correspond to the theoretical basis. the curve for each rotating speed tends to be linear, then for each rotating speed that increases, the gradient of the curve also increases. however, this does not directly mean that efficiency will also increase, and it should be looked at further on the efficiency vs. discharge curve. figure 9 shows that pat demonstrated characteristics corresponding to the theoretical basis. the curve for each rotating speed tends to be linear, then for each rotating speed that increases, the gradient of the curve also increases. this suggests that at an increased rotating speed of pat and for the same flow discharge, the torque generated will be greater. however, this does not directly mean that efficiency will also increase, and it should be looked at further on the efficiency vs. discharge curve. table 3. torque output results of moments-moment center (0 0 0) moment axis (1 0 0) zone moments (n-m) coefficients pressure viscous total pressure viscous total wall-28 0 0 0 0 0 0 wall-27 0 0.00013802982 0.00013802983 0 3.5392265e-06 3.5392265e-06 wall-25 3.8660795e-07 -5.5352484e-06 -5.5352484e-06 9.9130242e-09 -1.4192944e-07 -1.3201642e-07 wall-24 2.4576884e-06 5.9013209e-06 8.3590094e-06 6.3017651e-08 1.5131952e-07 2.1433357e-07 blade -43.9333 0.32219332 -43.611107 -1.1264948 0.0082613671 -1.1182335 hub -0.0035930499 0.12629554 0.12988859 9.2129484e-05 0.003238347 0.003330476 casing-discharge-solid -0.049116374 0.0018930088 -0.047223364 -0.0012593942 4.8538687e-05 -0.0012108555 casing-suction -3.8783185e-07 5.0647869 5.0647869 -9.9444067e-09 0.12986633 0.12986632 casing-discharge-solid -0.20231247 -0.16026746 -0.16026746 -0.0051874991 0.001078077 -0.0041094221 casing-impeller -0.0033532127 -0.17927596 -0.18262917 -8.5979812e-05 -0.0045968194 -0.0046827992 net -44.184487 5.3780762 -38.80641 -1.1329355 0.13789939 -0.99503614 table 4. mass rate output result parameters value unit inlet outlet mass flow 74.07208 74.27893 kg/s swirl number -1.34498 -0.68598 average total pressure 120000 1203.964 pa average radial flow angle -89.9994 6.846271 deg average theta flow angle -51.0569 30.13422 deg engr. passage loss coefficient -12.34489 norm. passage loss coefficient 0.989967 efficiency-hydraulic 20.74779 % axial forces -1810.518 nm torque -43.66385 n average mass-weighted table 5. numerical simulation data pat 400 rpm q (m3/h) h (m) p (w) ƞ (%) 266.66 12.13 1,617.37 18.38 255.04 11.12 1,434.62 18.60 238.22 9.90 1,242.79 19.37 221.66 8.59 1,087.94 21.01 197.86 7.08 873.88 22.95 180.05 6.07 767.14 25.82 160.79 5.06 635.04 28.71 138.10 4.05 473.43 31.13 112.14 3.04 319.49 34.46 83.99 2.03 160.39 34.61 45.05 1.02 5.68 4.56 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 131 figure 10 shows a parabolic curve with a critical point in the form of a maximum point. for an increased pat rotating speed, the curve will shift towards the right. meanwhile, the maximum efficiency value of each rotating speed does not differ much, which ranges from 35 % to 40 %. the discharge indicating the maximum efficiency point on the curve is the pat operating point for each rotating speed. from the discharge, the pat head and power indicating the pat operating point for each rotating speed can also be determined when returning to the head vs. discharge curve and the power vs. discharge curve. the pat operating points are indicated by a square-shaped symbol on each curve and are also shown in table 8. based on the data shown in table 8, the optimal operating point of each turbine rotation is directly proportional to the value of each test parameter. if a comparison of the pump performance curve and pat is carried out, the simulation results are in one graph, where the pump curve is displayed on the positive abscess and the pat curve on the negative abscess. this curve is shown in figure 11. figure 8. head vs. pat discharge for various rotating speeds figure 9. power vs debit of pat discharge for various rotating speeds table 6. numerical simulation data pat 800 rpm q (m3/h) h (m) p (w) ƞ (%) 242.23 13.15 2,588.27 29.88 232.34 12.14 2,349.16 30.62 215.96 11.14 2,124.46 32.48 201.12 9.92 1,870.00 34.48 189.30 9.12 1,645.06 35.05 176.44 8.11 1,449.23 37.26 160.26 7.10 1,108.96 35.86 140.71 6.09 738.90 31.73 117.65 5.08 547.19 33.69 95.26 4.07 284.79 27.04 58.01 3.06 26.73 5.54 table 7. results of the mesh independency test ∑ mesh element mass rate (kg/m) error (%) 3,572,720 54.9988 3,878,440 51.846 5.731 4,683,249 49.921 3.712 5,428,728 49.6031 0.638 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 132 based on the curve obtained in figure 11, it shows that the trend of the curve tends to decrease in each bep. this is due to a decrease in the head (h), which is directly proportional to the increase in discharge (q). based on the comparison of the head vs. discharge curve of the pump and the pat obtained, the value of the pump operating point and pat at various rotating speeds can be known through table 9. based on the curves and table above, it can be seen that for the same rotating speed, the pat has an operating point at a lower discharge compared to the operating point of the pump, but at a larger head. then, for the same one rotating speed, the highest efficiency of the pat is also lower than the highest efficiency of the pump. d. blade pressure contour analysis figure 12 (a) shows the pressure contours on the rear at side view, while figure 12 (b) shows the isometric view of the impeller. the simulation results show that the maximum pressure contours are 1,227 x 105 pa and the minimum pressure contours are -1,401,105 pa. in these two pictures show the contours of the pressure on the pat impeller blade. in both images, in contrast to dynamic pumps in general, it can be seen that the flow of water entering through the pat mashes the blade and hub parts of the impeller thoroughly. this can be understood because the inlet channel is in the radial direction and its located perpendicular to the rotary axis of the impeller, in contrast to dynamic pumps which generally have blade-offending channels. this results in a stream of water pounding the hub will cause losses because the impact located perpendicular to the rotating axis of the impeller causes the moment arm on the impeller not to form, so that the energy from the flow cannot be converted into the desired torque. this factor can also be used as a reason for the low efficiency of pat in this mixed flow pump. e. pat test results tests performed on mixed flow pumps as turbines can only be performed for rotational speeds of 400 rpm and 800 rpm. this is due to the limitations of the testing equipment, where the pump used for testing is only able to provide a maximum head of 2 meters for load less pat rotation. the pat test data are shown in table 10 table 8. pat optimal operating points at various rotating speeds. rpm optimal operating point q (m3/h) h (m) power (w) efficiency (%) 400 104.80 2.79 281.33 35.98 800 166.23 7.63 1.231.56 35.52 1,480 177.12 15.22 2.704.28 38.48 1,800 214.21 21.04 4.483.75 39.87 2,000 240.52 26.13 6.456.83 37.63 table 9. comparison of pump and pat operating points at various rotating speeds rpm pump pat q (m3/h) h (m) efficiency (%) q (m3/h) h (m) efficiency (%) 1,480 228.28 4.46 54.58 -177.12 15.22 38.48 1,800 268.24 6.81 59.17 -214.21 21.04 39.87 2,000 310.14 8.13 61.13 -240.52 26.13 37.63 figure 10. efficiency vs. debit of pat discharge for various rotating speeds s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 133 and table 11. table 10 shows the simulation results in the form of discharge, head, power and turbine efficiency at 400 rpm. table 11 shows the simulation results in the form of discharge, head, power and turbine efficiency at 800 rpm where the data in the two tables are then loaded into a graph shown in figure 13, figure 14, and figure 15. f. analysis of test results the results of tests carried out on the pat show that for the head, power, and discharge at a rotational speed of 400 rpm, it is not so much different from the curve of the simulation results, but for other parameters, each rpm is quite far different. the most noticeable differences are the head and discharge for a rotational speed of 800 rpm, as well as the efficiency of each rotating speed. the test results in various factors that result in losses in pat operations. the most important disadvantage is friction on the shaft. this is because, in numerical simulations, the pat shaft and its supporting components, such as bearings and figure 11. curve head vs debit of discharge pump and pat (a) (b) figure 12. pressure contours on the rear: (a) side view; (b) isometric view impeller table 10. test data on pat at a rotational speed of 400 rpm q (m3/h) h (m) p (w) ƞ (%) 51.88 0.82 10.89 9.42 74.21 1.51 21.33 7.00 73.55 1.83 23.16 6.30 70.92 1.95 22.99 6.10 74.21 1.91 26.28 6.80 51.88 0.78 10.85 9.85 73.55 1.47 21.04 7.15 72.89 1.77 22.88 6.52 70.27 1.90 22.71 6.25 73.55 1.87 25.93 6.91 51.22 0.77 10.66 9.98 72.89 1.45 20.81 7.21 72.24 1.78 22.63 6.45 69.61 1.90 22.46 6.24 72.89 1.89 25.71 6.86 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 134 lubricants, are not modeled. a comparison of the performance of the test results with the simulation results can be seen in figure 13, figure 14, and figure 15. based on the test and simulation analysis graphs, as seen in figure 13, the comparison between the head (h) and discharge (q) trend graph tends to increase during testing and simulation. while in figure 14, the test analysis graph between power (p) and discharge (q) shows that the trend tends to increase both at the time of testing and simulation. the graph of test analysis and simulation of efficiency (η) to discharge (q) is shown in figure 15. the simulation results show that the efficiency of each pat rotating speed tends to increase from discharge 49 m3/h to 110 m3/h. pat efficiency with a speed of 400 rpm began to decrease after passing discharge above 110 m3/h. meanwhile, the pat efficiency with a speed of 800 rpm only started to decline after the water debit was above 175 m3/h. the experimental results show that efficiency tends to increase as the flow rate increases. this shows conformity with the simulation results. however, it has not been validated as to what discharge the efficiency of each pat cycle will decrease. table 11. test data on pat at a rotational speed of 800 rpm q (m3/h) h (m) p (w) ƞ (%) 76.18 1.23 13.06 5.11 76.83 1.51 18.24 5.78 76.18 1.61 20.45 6.11 76.83 1.68 20.60 5.87 75.52 1.15 12.78 5.38 76.18 1.45 18.14 6.01 75.52 1.58 20.12 6.17 76.18 1.62 20.28 6.02 74.86 1.18 12.81 5.32 75.52 1.43 17.82 6.06 74.86 1.58 20.00 6.19 75.52 1.61 20.16 6.08 figure 13. comparison curve of head vs discharge test and simulation results figure 14. power vs discharge comparison curve of test and simulation results s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 135 iv. conclusion this paper has discussed a method for predicting the performance characteristics of a mixed flow type pump when applied as a turbine (pat) for remote rural micro hydro applications. research to predict the performance of a mixed flow pump which is operated as a turbine at various rotational speeds is carried out using the cfd numerical simulation method. the results obtained are shown in a performance curve. it is known that the highest efficiency for each rotating speed ranges from 35-40 %. the validation of the numerical simulation results is carried out by conducting experiments. the test results show the characteristics of pat, namely the performance range that is close to the results of the numerical simulation with a difference of 10 %. to get more convincing simulation validation results, it is recommended to carry out more simulations in the range of rotational speed/flow rate variations according to the rotational speed of the test equipment capacity. experimental work by connecting a pat with a generator is considered for further work. acknowledgments our gratitude goes to mr. ir. i nengah diasta, m.t., for the permission given to use the the material for this research and to publish this paper. we would like to thank also to all those who have helped and supported in the process of preparing this manuscript. declarations author contribution s. mejiartono: writing original draft, writing review & editing, conceptualization, formal analysis, investigation, visualization, resources, software. m.f. hikmawan: writing original draft, writing review & editing, conceptualization, formal analysis, investigation, visualization, resources, software. a.s. nugraha: visualization, supervision. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] e. erdiwansyah, m. mahidin, h. husin, n. nasaruddin, k. khairil, m. zaki, et al., "investigation of availability, demand, targets, and development of renewable energy in 2017–2050: a case study in indonesia," international journal of coal science & technology, vol. 8, pp. 483-499, 2021. [2] y. e. unutmaz, a. demirci, s. m. tercan, and r. yumurtaci, "electrical energy demand forecasting using artificial neural network," in 2021 3rd international congress on humancomputer interaction, optimization and robotic applications (hora), pp. 1-6, 2021. [3] i. w. ngarayana, j. sutanto, and k. murakami, "predicting the future of indonesia: energy, economic and sustainable environment development," in iop conference series: earth and environmental science, p. 012038, 2021. [4] a. s. ahmar, "a comparison of α-sutte indicator and arima methods in renewable energy forecasting in indonesia," int. j. eng. technol, vol. 7, pp. 20-22, 2018. [5] r. a. subekti, "survey potensi pembangkit listrik tenaga mikro hidro di kuta malaka kabupaten aceh besar propinsi nanggroe aceh darussalam," journal of mechatronics, electrical power, and vehicular technology, vol. 1, pp. 5-12, 2012. [6] e. k. bawan, a. d. palintin, and e. a. patandianan, "analisis potensi energi terbarukan pembangkit listrik tenaga mikrohidro di manokwari selatan," jurnal penelitian saintek, vol. 26, pp. 24-34, 2021. [7] m. a. isa, p. sudjono, t. sato, n. onda, i. endo, a. takada, et al., "assessing the sustainable development of micro-hydro power plants in an isolated traditional village west java, indonesia," energies, vol. 14, p. 6456, 2021. [8] a. morabito and p. hendrick, "pump as turbine applied to micro energy storage and smart water grids: a case study," figure 15. head vs discharge comparison curve of test and simulation results https://mev.lipi.go.id/ https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1007/s40789-020-00391-4 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1109/hora52670.2021.9461186 https://doi.org/10.1088/1755-1315/753/1/012038 https://doi.org/10.1088/1755-1315/753/1/012038 https://doi.org/10.1088/1755-1315/753/1/012038 https://doi.org/10.1088/1755-1315/753/1/012038 http://dx.doi.org/10.14419/ijet.v7i1.6.12319 http://dx.doi.org/10.14419/ijet.v7i1.6.12319 http://dx.doi.org/10.14419/ijet.v7i1.6.12319 https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.14203/j.mev.2010.v1.5-12 https://doi.org/10.14203/j.mev.2010.v1.5-12 http://dx.doi.org/10.21831/jps.v26i1.37311 http://dx.doi.org/10.21831/jps.v26i1.37311 http://dx.doi.org/10.21831/jps.v26i1.37311 http://dx.doi.org/10.21831/jps.v26i1.37311 https://doi.org/10.3390/en14206456 https://doi.org/10.3390/en14206456 https://doi.org/10.3390/en14206456 https://doi.org/10.3390/en14206456 https://doi.org/10.1016/j.apenergy.2019.03.018 https://doi.org/10.1016/j.apenergy.2019.03.018 s. mejiartono et al. / journal of mechatronics, electrical power, and vehicular technology 13 (2022) 125-136 136 applied energy, vol. 241, pp. 567-579, 2019. [9] m. stefanizzi, t. capurso, g. balacco, m. binetti, s. m. camporeale, and m. torresi, "selection, control and technoeconomic feasibility of pumps as turbines in water distribution networks," renewable energy, vol. 162, pp. 12921306, 2020. [10] f. plua, v. hidalgo, p. a. lópez-jiménez, and m. pérez-sánchez, "analysis of applicability of cfd numerical studies applied to problem when pump working as turbine," water, vol. 13, p. 2134, 2021. [11] d. štefan, m. rossi, m. hudec, p. rudolf, a. nigro, and m. renzi, "study of the internal flow field in a pump-as-turbine (pat): numerical investigation, overall performance prediction model and velocity vector analysis," renewable energy, vol. 156, pp. 158-172, 2020. [12] x. su, s. huang, x. zhang, and s. yang, "numerical research on unsteady flow rate characteristics of pump as turbine," renewable energy, vol. 94, pp. 488-495, 2016. [13] s. abazariyan, r. rafee, and s. derakhshan, "experimental study of viscosity effects on a pump as turbine performance," renewable energy, vol. 127, pp. 539-547, 2018. [14] s. yang, f. kong, w. jiang, and x. qu, "research on rotational speed to the influence of pump as turbine," in iop conference series: earth and environmental science, p. 042023, 2012. [15] m. m. ghorani, m. h. s. haghighi, a. maleki, and a. riasi, "a numerical study on mechanisms of energy dissipation in a pump as turbine (pat) using entropy generation theory," renewable energy, vol. 162, pp. 1036-1053, 2020. [16] s. s. yang, s. derakhshan, and f. y. kong, "theoretical, numerical and experimental prediction of pump as turbine performance," renewable energy, vol. 48, pp. 507-513, 2012. [17] d. zariatin, d. rahmalina, e. prasetyo, a. suwandi, and m. sumardi, "the effect of surface roughness of the impeller to the performance of pump as turbine pico power plant," journal of mechanical engineering and sciences, vol. 13, pp. 4693-4703, 2019. [18] t. lin, z. zhu, x. li, j. li, and y. lin, "theoretical, experimental, and numerical methods to predict the best efficiency point of centrifugal pump as turbine," renewable energy, vol. 168, pp. 31-44, 2021. [19] y. han and l. tan, "influence of rotating speed on tip leakage vortex in a mixed flow pump as turbine at pump mode," renewable energy, vol. 162, pp. 144-150, 2020. [20] j. c. alberizzi, m. renzi, m. righetti, g. r. pisaturo, and m. rossi, "speed and pressure controls of pumps-as-turbines installed in branch of water-distribution network subjected to highly variable flow rates," energies, vol. 12, p. 4738, 2019. [21] o. fecarotta, h. m. ramos, s. derakhshan, g. del giudice, and a. carravetta, "fine tuning a pat hydropower plant in a water supply network to improve system effectiveness," journal of water resources planning and management, vol. 144, p. 04018038, 2018. [22] m. perez-sanchez, f. j. sánchez-romero, h. m. ramos, and p. a. lópez-jiménez, "improved planning of energy recovery in water systems using a new analytic approach to pat performance curves," water, vol. 12, p. 468, 2020. [23] m. postacchini, g. darvini, f. finizio, l. pelagalli, l. soldini, and e. di giuseppe, "hydropower generation through pump as turbine: experimental study and potential application to small-scale wdn," water, vol. 12, p. 958, 2020. [24] a. carravetta, l. antipodi, u. golia, and o. fecarotta, "energy saving in a water supply network by coupling a pump and a pump as turbine (pat) in a turbopump," water, vol. 9, p. 62, 2017. [25] m. rossi, m. righetti, and m. renzi, "pump-as-turbine for energy recovery applications: the case study of an aqueduct," energy procedia, vol. 101, pp. 1207-1214, 2016. [26] m. sosnowski, j. krzywanski, k. grabowska, and r. gnatowska, "polyhedral meshing in numerical analysis of conjugate heat transfer," in epj web of conferences, p. 02096, 2018. https://doi.org/10.1016/j.apenergy.2019.03.018 https://doi.org/10.1016/j.renene.2020.08.108 https://doi.org/10.1016/j.renene.2020.08.108 https://doi.org/10.1016/j.renene.2020.08.108 https://doi.org/10.1016/j.renene.2020.08.108 https://doi.org/10.1016/j.renene.2020.08.108 https://doi.org/10.3390/w13152134 https://doi.org/10.3390/w13152134 https://doi.org/10.3390/w13152134 https://doi.org/10.3390/w13152134 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2020.03.185 https://doi.org/10.1016/j.renene.2016.03.092 https://doi.org/10.1016/j.renene.2016.03.092 https://doi.org/10.1016/j.renene.2016.03.092 https://doi.org/10.1016/j.renene.2018.04.084 https://doi.org/10.1016/j.renene.2018.04.084 https://doi.org/10.1016/j.renene.2018.04.084 https://doi.org/10.1088/1755-1315/15/4/042023 https://doi.org/10.1088/1755-1315/15/4/042023 https://doi.org/10.1088/1755-1315/15/4/042023 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2020.08.102 https://doi.org/10.1016/j.renene.2012.06.002 https://doi.org/10.1016/j.renene.2012.06.002 https://doi.org/10.1016/j.renene.2012.06.002 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.15282/jmes.13.1.2019.24.0394 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.12.040 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.1016/j.renene.2020.08.033 https://doi.org/10.3390/en12244738 https://doi.org/10.3390/en12244738 https://doi.org/10.3390/en12244738 https://doi.org/10.3390/en12244738 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.1061/(asce)wr.1943-5452.0000961 https://doi.org/10.3390/w12020468 https://doi.org/10.3390/w12020468 https://doi.org/10.3390/w12020468 https://doi.org/10.3390/w12020468 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w12040958 https://doi.org/10.3390/w9010062 https://doi.org/10.3390/w9010062 https://doi.org/10.3390/w9010062 https://doi.org/10.3390/w9010062 https://doi.org/10.1016/j.egypro.2016.11.163 https://doi.org/10.1016/j.egypro.2016.11.163 https://doi.org/10.1016/j.egypro.2016.11.163 https://doi.org/10.1051/epjconf/201818002096 https://doi.org/10.1051/epjconf/201818002096 https://doi.org/10.1051/epjconf/201818002096 introduction ii. materials and methods iii. results and discussions conclusion acknowledgments references mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university jl. grafika no. 2, yogyakarta, 55281, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia ocktaeck lim, ph.d. school of mechanical engineering university of ulsan daehakro 93, nam-gu 44610 ulsan, korea, republic of prof. juan carlos alvarez dept. electrical engineering, university of oviedo calle san francisco, 1, 33003 oviedo, asturias, spain prof. dr. murat lüy department of electrical and electronic engineering, kırıkkale universitesi ankara yolu 7. km, 71450 yahşihan/kırıkkale, turkey prof. istván patkó óbuda university, budapest, 6. doberdó str., budapest h-1034 hungary dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. irhan febijanto the agency for the assesment and application of technology kawasan puspiptek serpong tangerang selatan, indonesia dr. narankhuu jamsran thomas air llc, mongolia "tushig" center 204, seoul street23, 4th khoroo, sukhbaatar district, ulaanbaatar, mongolia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university jl. grafika no.2, yogyakarta 55281, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, lyonel-feininger-str. 28, 80807 munchen, germany dr. si steve li electromechanical system development, general electric global research centre 610 london square drive, clifton park, ny12065, united states anusua ghosh school of electrical and information engineering, university of south australia 101 currie st, adelaide sa 5001, australia ir. arko djajadi, ph.d. swiss german university edutown bsd city – tangerang 15339, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang jl. semarang no. 5, malang, jawa timur, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii dr. ir. rizqon fajar, m.sc. the agency for the assesment and application of technology gd. 230 kawasan puspiptek serpong tangerang selatan, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney camperdown nsw 2006, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) kampus eepis/pens, jl. raya its sukolilo, surabaya 60111, indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. trina fizzanty center for science and technology development studies – lipi widya graha lipi, 8th fl, jl. jendral gatot subroto kav. 10 jakarta, indonesia anna maria sri asih, s.t., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university jl. grafika no. 2 yogyakarta 55281, indonesia dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, jl. mayjen haryono 167 malang, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta jl. ir. sutami 36a, surakarta, 57126, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales unsw campus, building 17, r 131, canberra act 2610, australia. dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember campus its keputih, surabaya 60111, indonesia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia kampus ui depok 16424 depok, jawa barat, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau kampus bina widya, simpang baru, tampan, kota pekanbaru, riau 28293, indonesia pudji irasari, m.sc.rer.nat. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. sunit hendrana research center for physics lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university jl. grafika no. 2, yogyakarta 55281, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan 93 daehak-ro, mugeo-dong, namgu, ulsan, south korea yusie rizal, ph.d. cand. dept. engineering science, national cheng kung university no. 1 號, dasyue rd, east district, tainan city, 701, taiwan. dr. yuliadi erdani politeknik manufaktur bandung jl. kanayakan no. 21 dago, bandung – 40135, indonesia dr. joga dharma setiawan faculty of engineering, diponegoro university jl. prof h. soedarto, sh., tembalang, semarang 50275, indonesia esa prakasa, ph.d. research centre for informatics – lipi komp lipi jl. sangkuriang, bld 20, 3rd fl, bandung 40135, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. widodo budi santoso research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, bld 60, 2nd fl, bandung 40135, indonesia kadek heri sanjaya, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia suprapto, ph.d. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 viii departement of electronics engineering, yogyakarta state university jl. colombo no.1, karang malang, caturtunggal, di yogyakarta 55281, indonesia dr. ir. yoyon ahmudiarto, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. edwar yazid research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university 1095 dalgubeol-daero, dalseo-gu, daegu 42601, korea, republic of dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional jl. ph.h. mustafa no. 23, bandung, jawa barat, indonesia alexander christantho budiman, ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. rina ristiana technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. anto tri sugiarto, m.eng. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung jl. ganesha no. 10, bandung 40135, indonesia dr. eng. aam muharam, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr.eng. edy riyanto, s.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. anwar muqorobin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia bambang wahono, m.eng., ph.d. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ghalya pikra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia vita susanti, s.kom. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia hendri maja saputra, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia dr. natalita maulani nursam research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia dr. joko hariyono, s.t., m.eng. government of yogyakarta special region komplek kepatihan, danurejan yogyakarta, indonesia yusuf nur wijayanto, ph.d. research centre for electronics and telecommunication komp lipi jl. sangkuriang, blg 20, 4th fl, bandung 40135, indonesia dr. edi kurniawan, s.t., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. deni shidqi khaerudini, s.si., m.eng. research centre for physics – lipi gedung 440, kawasan puspiptek serpong, banten 15314, indonesia dr. irwan purnama, m.sc.eng. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia achmad praptijanto, s.t., m.d.m research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sunarto kaleg, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia midriem mirdanies, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 ix sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia erie martides, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia agus risdiyanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia rudi darussalam, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia aditya nugraha, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia ahmad rajani, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia amin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia maulana arifin, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia budi azhari, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia henny sudibyo, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andri joko purwanto, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia andry masri, m.sn. department of product design, faculty of art and design, institut teknologi nasional jl. ph.h. mustofa no.23, bandung, jawa barat, indonesia roni permana saputra, m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia sudirja, m.t. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia veny luvita, m.t. technical implementation unit for instrumentation development – lipi komp lipi jl. sangkuriang, blg 30, bandung 40135, indonesia mulia pratama, s.t., m.eng. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia asep nugroho, s.si, m.eng, m.sc. research centre for electrical power and mechatronics – lipi komp lipi jl. sangkuriang, blg 20, 2nd fl, bandung 40135, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 x publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (national research and innovation agency). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xi 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident, they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xii crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiv presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xv instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xvi • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor, city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software mev mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2012 rcepm lipi all rights reserved doi: 10.14203/j.mev.2012.v3.65-72 a review of atomic layer deposition for nanoscale devices review deposisi lapisan tipis untuk peralatan skala nano edy riyanto a, b, c, *, estiko rijanto b, budi prawara b a state key laboratory for modification of chemical fibers and polymer materials, college of material science and engineering, donghua university, shanghai 201620, people’s republic of china b research centre for electrical power & mechatronics, indonesian institute of sciences, komp lipi jl cisitu 21/54d, gd 20, bandung 40135, indonesia c plasma physics & application laboratory, college of science, donghua university, shanghai 201620, people’s republic of china received 14 october 2012; accepted 31 october 2012 published online 18 december 2012 abstract atomic layer deposition (ald) is a thin film growth technique that utilizes alternating, self-saturation chemical reactions between gaseous precursors to achieve a deposited nanoscale layers. it has recently become a subject of great interest for ultrathin film deposition in many various applications such as microelectronics, photovoltaic, dynamic random access memory (dram), and microelectromechanic system (mems). by using ald, the conformability and extreme uniformity of layers can be achieved in low temperature process. it facilitates to be deposited onto the surface in many variety substrates that have low melting temperature. eventually it has advantages on the contribution to the wider nanodevices. key words: thin coating, atomic layer deposition, nanoscale devices. abstrak atomic layer deposition (ald) adalah teknik penumbuhan lapisan tipis yang menggunakan reaksi kimia jenuh antara gas pendahulu untuk mendapatkan deposisi lapisan skala nano. teknik ini menjadi subyek yang sangat menarik saat ini untuk deposisi lapisan sangat tipis pada berbagai aplikasi seperti mikroelektronik, photovoltaic, dynamic random access memory (dram) dan sistem mikroelektromekanik (mems). dengan menggunakan ald keseragaman dan penglarasan dari lapisan dapat dicapai pada temperatur proses yang rendah. deposisi lapisan dengan teknik ini dapat digunakan pada beragam substrat yang memiliki temperatur leleh yang rendah. keuntungan dari ald adalah teknik deposisi ini memiliki kontribusi yang luas untuk aplikasi peralatan skala nan.o kata kunci: lapisan tipis, atomic layer deposition, peralatan skala nano. i. introduction atomic layer deposition (ald) is a technology which can be used to fabricate a very high-quality thin films based on alternate selflimiting surface chemical reactions which have extreme uniformity on the three-dimensional structures, high density, low porosity, freedom from defect [1-4], with conformality and precise thickness control [5-7]. it has been applied in the numerous advanced technologies for the fabrication of nanoscale thin films such as microelectronics, complementary metal oxide semiconductor (cmos) transistors, dram memory, mems/nems, energy conversion, photovoltaics, and display devices [8-12] that require precise control of film properties in thickness, uniformity, and conformability. atomic layer deposition is a technique which is originally developed to produce thin films for electroluminescent displays, but was later adopted for other substrate as well [13]. this technique is a thin film growth technique that relies on two sequential, self-limiting surface reactions between gas phase precursor molecules and a solid surface as illustrated in fig. 1 [14-17]. the films formed by sequential pulsing of two or * corresponding author. tel: +62-22-2503055 e-mail: edy.riyanto@lipi.go.id http://dx.doi.org/10.14203/j.mev.2012.v3.65-72 e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 66 more reactants, using purging with inert gas between the precursor pulses to avoid gas-phase reactions [17]. due to self-limited film growth mechanism, the film deposited by ald has shown excellent step coverage and conformality [6], because the reactions are driven to completion during every reaction cycle [18]. the surface is exposed to reactant a, which react to initial surface sites. then, after the product from reaction a are purged, the surface is exposed to reactant b. this reaction regenerates the initial functional groups and prepares the surface for the next exposure to reactant a. the thickness is grown to the desired thickness by repeating this ab sequence [19, 20]. the reactor is purged with an inert gas between the precursor pulses [21]. with a proper adjustment of the experimental conditions the process proceeds via saturative steps [21]. under such conditions the growth is stable and the thickness increase is constant in each deposition cycle [21]. as the reactions are self-limiting, ald does not require line-of-sight for deposition and high surface area to volume structures, and complex geometries can be conformally coated [19, 20]. in the case of al2o3 ald, in the first half-reaction trimethylaluminum (al(ch3)3) molecules react with hydroxyl (-oh) groups attached to the surface, until a saturation of available reaction sites is reached. in the second half-reaction the surface is oxidized by water vapor (thermal ald) or in oxygen plasma (plasma-assisted ald) to form aluminum oxide [22]. precursor chemistry plays a key role in ald, the precursor must of course be volatile and thermally stable. these are may be gases, liquids, or solids. precursors must chemisorb on the surface or react rapidly with the surface group and react aggressively with each other. in that way, it is possible to reach the saturation stage in a short time (less than 1 s) and thereby ensure a reasonable deposition rate [21]. this paper aims to provide information on the latest developments in thin film deposition technology by atomic layer deposition method and its application. ii. description of system a. the schematic of ald system fig. 2 shows the ald flow reactor designed for the substrate coating. two separate precursor chambers are connected to the main reactor separately by valves 4, respectively. each precursor tube is connected with inert gas that is controlled by a mass flow controller. the pressure inside the reactor is monitored by pressure measurement gauges. valve 10 and the vacuum pump are used for controlling the pressure inside the reactor. fig. 3 shows the schematic illustration of the constructed ald. the ald consist of the reaction chamber part and the supply part for reactants, carrier gases and purge gases. the illustration of the fig. 2 are as follow, (1) reaction chamber, (2) shower head, (3) substrate holder, (4) reactant canister, (5) carrier & purge gas, (6) diaphragm valve, (7) vacuum gauge, (8) mass flow controller, (9) control system. the typically gas flow mechanism of the existing ald systems are generally classified fig.1. a schematic drawing of the ab reaction sequence during atomic layer deposition process [19, 20]. fig. 2. schematic of ald process (1.precursor a, 2.precursor b, 3.gas cylinder, 4.precursor control valve, 5.control valve, 6.check valve, 7.substrate, 8.ald chamber, 9.pressure gauge, 10.needle valve, 11.vacuum pump). 8 7 1 2 3 4 4 6 5 5 9 10 11 inlet outlet fig. 3. schematic illustration of the ald construction [23]. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 67 into two categories, these are the laminar gas flow type which have advantages on the high material utilization efficiency and minimization of the reaction volume with inherently disadvantages on the thickness non-uniformity due to source depletion at inlet area makes it unsuitable for large area deposition, on the other hand the shower-head type has uniform source flux, but a long purge time due to the large reaction volume and the low conductance of the shower-head hole makes it difficult to realize a pure ald process [24]. b. reaction mechanism the mechanisms that have been identified for bonding gaseous reactants on solid supports in a saturating manner are illustrated with molecule mln used as an example. in mln, m is a central metal atom, l is a ligand attached to it and n is the number of ligands. mln can be represented al(ch3)3 [25]. the most common example of saturating gassolid reactions is ligand exchange reaction, where the reactant molecule (mln) is split and one of its ligands (l) combines with a surface group (a) to form a volatile compound that is released as a gaseous reaction product (al) [25]. symbol ׀׀ denotes the surface. mln-1 + al (g) (1) – ׀׀ a + mln (g) – ׀׀ water and trimethylaluminum are commonly used as precursors in the deposition of al2o3 by using atomic layer deposition [26, 27]. al2o3 is one of the most attractive and extensively studied materials by ald [4, 18, 26], because of its chemical and thermal stability, and good adhesion to the various materials [28]. on the alumina coating, it was previously shown that when h2o is used as a source for oxygen, al2o3 is formed by the chemical exchange between al(ch3)3 and h2o [4,29], it can be used to illustrate the basic principles of ald. al2o3 is a binary material. the binary reaction for al2o3 is [4,16]: 2 al(ch3)3 + 3 h2o al2o3 + 6 ch4 (2) this binary reaction can be devided into two reactions to define al2o3 ald [15, 20,30,31,32]: aloh* + al(ch3)3 aloal(ch3)2* + ch4 alch3* + h2o aloh* + ch4 (3) where asterisks indicate the surface species. al2o3 ald can be deposited at the low temperatures required for coating polymers. the al2o3 ald films are amorphous and extremely conformal to the underlying substrate [31]. iii. growth theory the requirements of the amorphous materials growth are the surface mobility of the adsorbed precursor fragment should be so low that the precursor fragment is localized at the point where it first adheres to the surface, as well as the network of reactive sites should provide more location possibilities than the atomic arrangement for the film material. this can be achieved if the adsorbed precursor fraction is capable of forming bonds to both bridging and terminating atoms. an experimental example for film formation under such condition could be growth of al2o3 by al(ch3)3 and h2o. this system has a flexibility in the network of reactive sites in the way that al(ch3)x may form relatively strong bonds to both terminating and bridging oxygen atoms, and thus disturb a repetitive construction pattern needed in order to form a crystalline material [17]. al2o3 ald is a particularly robust and welldefined ald system [14], and can be considered a rather typical and “ideal” ald process [26]. al2o3 ald films can be pinhole-free as demonstrated by electrical instruments and can be deposited on polymer substrates [14]. one basic condition for a successful ald process is that the binding energy of a monolayer chemisorbed on a surface is higher than the binding energy of subsequent layers on top of the formed layer, that it can be controlled by the reaction temperature. the temperature must be kept low enough to keep the monolayer on the surface until the reaction with the second reactant occurs, but high enough to re-evaporate or break the chemisorption bond. the greater the difference between the bond energy of a monolayer and the bond energies of the subsequent layers, the better the self-controlling characteristics of the process [33]. it is correlated to the basic technique of ald that it depends on the difference between chemisorption and physisorption. the physisorption involves the weak van der waal's forces, whereas chemisorption involves the formation of relatively strong chemical bonds and requires some activation energy, therefore it may be slow and not always reversible. the chemisorptions will dominate at the certain temperatures, which correspond to the best condition of ald operating. on the other hand the chemisorption is the reason that the process is self-controlling and insensitive to the pressure and substrate changes. it is due to the only one of atomic or molecular layer can be adsorbed at the same time [33]. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 68 iv. characteristic of ald growth temperature is one of the three parameters, together with the reactant and the surface, that determine the amount and the type of species adsorbed in irreversible, saturating chemisorptions [26]. fig. 4 shows the growth rate of ald as a function of growth temperature, illustrating general growth characteristics. when the ald process is performed at temperatures which provide sufficient thermal energy for the chemical reactions, the growth rate usually remains constant with self-terminating reactions [8, 26, 34]. this temperature range is often called the “ald process window”. this nearly constant growth rate for a range of growth temperature during ald provides better reproducibility in film thickness than those of other deposition methods [8, 18]. if the growth temperatures are greater than the ald window temperature, the growth rate usually increases. it is due to the thermal decomposition of the precursor which leads to disturb the self limitation mechanism [8]. the distinctive feature of ald is that the reactions are saturative, which makes the films growth self-limiting. experimentally it can be verified by observing that the deposition rate per cycle stabilizes to a constant level with increasing precursor pulse time or dose. the self-limiting growth ensures that each cycle deposits the same amount of material on all surfaces independent of the precursor dose received as long as the dose is high enough to saturate the reactions [35]. as a consequence, the ald methods offers excellent large area uniformity, conformality and film thicknesses are accurately controlled simply by the number of deposition cycles applied [35, 36]. two factors have been identified to cause the saturation of the surface with adsorbed species in a selfterminating gas-solid reaction, these are steric hindrance of the ligands and the number of reactive sites. steric hindrance of the ligands can cause the ligands of the chemisorbed species to shield part of the surface from being accessible to the reactant [26]. one of the most important characteristic of ald is the ability to deposit relatively high quality films at low growth temperatures. however, thermal activation for precursor molecule adsorption and surface reaction with reactant is necessary for ald, thus substrate heating is required. for a certain material systems such as al2o3 ald which using tma and water, it is possible to deposit relatively pure films at growth temperature lower than 100°c [37, 38]. although the film density was lower and the hydrogen content in the film was higher compared to film deposited at elevated growth temperatures, the film properties were relatively good with smooth surfaces and low leakages currents [37, 38]. increased ald cycle time is necessary at lower temperatures because of the slower reaction rates and longer required purge times for h2o reactant [38]. the studies have shown that ald process temperature for polymers application should be limited to lower than 150°c [37]. most of polymers do not have reactive nucleation sites for ald [37, 39]. it makes complicate for the ald surface reactions. many polymers, such as polyethylene and polypropylene are saturated hydrocarbons that lack typical chemical functional groups such as hydroxyl (-oh) species [36, 39]. al2o3 ald is remarkably robust and has demonstrated an ability to deposit al2o3 films on nearly every substrate. the ability of al2o3 to deposit with low temperature on a variety substrates led to the judgment that al2o3 ald was a good candidate for the deposition of inorganic films on polymers [39]. although, the polymer substrates that do not have reactive nucleation sites can be coated by the penetration of tma molecules [18], the existence of reactive sites is very important. it has an effect on the quality of the films that will be achieved. ald on polymer surfaces containing surface groups receptive to ald nucleation, such as –oh and other polar groups is expected to produce more uniform and conformal film coverage, without substantial subsurface fig. 5. growth mechanism of al2o3 ald on the inorganic polymer [18]. fig. 4. general growth characteristics of ald a function of growth temperature. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 69 growth [40]. reactant penetration and subsurface inorganic nucleation in a polymer film can negatively effects material properties. subsurface oxide growth can also impede the performance of ald barrier layers formed on polymers films [41]. the growth mechanism of ald onto the polymer substrate that does not have surface functional group is depicted as fig.5. it have shown that the precursor of al(ch3)3 diffuses into the near surface region of the polymer (a), cluster of the ald material form in the near surface region as a result of bimolecular reaction between the two ald precursors (b) , the clusters grow and eventually begin to coalesce (c), a continuous film is formed that prevents the diffusion of additional precursor into the polymer (d), and it will be continued that the ald materials grows linearly on the continuous ald film [18]. because of the covalent bonding, the adhesion of ald-grown al2o3 layer with the substrate is commonly excellent. biopolymers which typically have functional surface groups contribute to improve the bonding between the substrate and the al2o3 layer. it is the possibility that has made the biopolymeric materials more interesting substrates to create efficient gas and moisture barrier materials when combined with a thin al2o3 coating than regular oil-based polymers, such as polyethylene, polypropylene, or polyethylene terephthalate, for instance [42]. the ability to deposit films at low growth temperature is very attractive for polymer-based devices and for coating heat-sensitive materials such as polymers and biomaterials. the growth temperature for metal ald is generally higher than that for oxide ald, partially due lower reactivity of reducers than oxidizers [37]. v. ald for nanotechnology application a. mems devices micro electro mechanical systems (mems) comprise a variety of functional mechanical devices fabricated on length scales from fractions of a micrometer to millimeters [43,44] that offers considerable potential due to small size, small weight, and low power of fabricated devices which can enable compelling advantages in certain product specifications [45,46]. some of the applications of mems are motion sensing, optical switching, mechanical actuators [43, 47, 48], chemical sensors [43,48], and photonic applications [43,49]. adhesion, friction and wear at the nanometer size scale become critical and can be detrimental to the efficiency, power output and reliability of mems devices [50,51]. al2o3 atomic layer deposition with 10 nm thickness in mems devices application has been applied on the wear resistant films of the surfacemicromachined (smm) devices [20,43,52]. in order to achieved 10 nm of al2o3 was deposited using 100 cycles of trimethylaluminum (al(ch3)3) and water (h2o) as precursors. fig. 6(b) shows the cross section image of the structure of the hub [43]. the aluminum oxide (al2o3) deposited film as examined in three locations of the structure. locations 1-3 are points of examination of the ald film by tem. location 1 is on the top of the gear surface, which is possible to be exposed by direct line-ofsight to the gas source. location 2 is on the underside of the gear, shadowed from the gas source, and location 3 is at the end of a long channel inside the hub structure with the film thickness ranges of all of those are from 10 nm at location 1 to 10.5 nm at location 3 [43]. b. dynamic random access memory (dram) the data storage in drams is based on introducing a charge into the memory capacitor. the charge must be repeatedly refreshed (“dynamic”), the time interval between the fig. 6. (a) mems microengine, consist of a gear turning on a hub. an electrostatic comb-drive actuator (not shown) drives the gear. the structure uses 3 μm thick polycrystalline si for mechanical structures. the sacrificial oxide has been removed to release the device. (b) cross section of the hub showing the contact surfaces of the gear and hub, and the buried channel in the interior of the hub [43]. fig. 7. tem cross section images of location 1-3 [43]. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 70 refreshments depending on the leakage current through the capacitor. the charge storage capacity of the capacitor is determined by its capacitance, which can be increased by decreasing the thickness of the dielectric layer, by using a dielectric material with a higher dielectric constant [49, 53], or by increasing the active capacitor area [53]. in the stacked dram memory cells, the capacitors are fabricated above the silicon substrate. fig.8. shows the examples of stacked capacitor structures. in trenched dram memory cells, the memory capacitors are buried into the silicon substrate. the capacitors are fabricated into high aspect ratio trenches, and thus have high effective surface areas [53], which can be contributed by ald process [49]. vi. summary ald has shown the reliability on the application of microelectronics, mems, dram, and many other nanoscale devices with accurately controlled thickness of thin films by the number of deposition cycles applied. one of the most important factors that have effect on the deposited thickness and uniformity is the temperature which can be indicated by using the range of ald window process. at the certain temperatures, the chemisorptions will dominate to achieve the best condition of ald operating with the process is self-controlling and insensitive to the pressure and substrate changes. in the coating application by tma molecules as precursor, the ald can be used to be deposited onto the substrates that have or without reactive nucleation sites, especially on the polymer substrates. subsurface growth mechanism occurred as initial growth onto the hydrophobic polymers. although it can be grown, the existence of reactive sites is very important to obtain the quality of the films with outstanding properties. references [1] p.s. maydannik, t.o. kääriäinen, d.c. cameron, “an atomic layer deposition process for moving flexible substrate,” chemical engineering journal, vol.171, pp.345-349, 2011. [2] e. langereis, m. creatore, s.b.s. heil, m.c.m. van de sanden, and w.m.m. kessels, “plasma-assisted atomic layer deposition of al2o3 moisture permeation barriers on polymers,” applied physics letters, vol.89, article number: 081915, 2006. [3] k.-s.an, w. co, k. sung, s.s. lee, and y. kim, “preparation of al2o3 thin films by atomic layer deposition using dimethylaluminum isopropoxide and water and their reaction mechanisms,” bulletin of the korean chemical society, vol.24, pp.1659-1663, 2003. [4] t.k. minton, b. wu, j. zhang, n.f.lindholm, j. o.patchen, s.m. george, and m.d. groner, “protecting polymers with atomic layer deposition coatings,” acs applied materials and interfaces, vol.2, pp.2515-2520, 2010. [5] v.r. rai, v. vandalon, and s. agarwal, “surface reaction mechanisms during ozone and oxygen plasma assisted atomic layer deposition of aluminum oxide,” langmuir, vol.26, pp.13732-13735, 2010. [6] j.-h. ahn, s.-h. kwon, j.-h. kim, j.-y. kim, and s.w. kang, “theoritical simulation of surface evolution using the random deposition and surface relaxation for metal oxide film in atomic layer deposition,” journal of material science and technology, vol.26, pp.371-374, 2010. [7] x. jiang., r. chen., s.f. bent., “spacial control over atomic layer deposition using microcontact-printed resists,” surface & coatings technology, vol.201, pp.8799-8807, 2007. [8] h. kim, “characteristic and applications of plasma enhanced-atomic layer deposition,” thin solid films, vol.519, pp.6639-6644, 2011. [9] r.l. puurunen., “growth per cycle in atomic layer deposition: a theoretical fig. 8. (a) example of a simple stacked dram capacitor structure, (b) concave stacked dram capacitor structure [53]. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 71 model, chemical vapor deposition,” vol.9, pp.249-257, 2003. [10] w.-s. jeon., s. yang., c.-s. lee., s.-w. kang., “atomic layer deposition of al2o3 thin films using trimethyl aluminum and isopropyl alcohol,” journal of the electrochemical society, vol.149, pp.c306c310, 2002. [11] k. tapily., j.e. jakes., d.s. stone., p. shrestha., d. gu., h. baumgart., a.a. elmustafa., “nanoindentation investigation of hfo2 and al2o3 films grown by atomic layer deposition,” journal of the electrochemical society, vol.155, pp.h545h551, 2008. [12] v. sammelselg., r. rammula., j. aarik., a. kikas., k. kooser., t. käämbre., “xps and afm investigation of hafnium dioxide thin films prepared by atomic layer deposition on silicon,” journal of electron spectroscopy and related phenomena, vol.156, pp.150-154, 2007. [13] r.beetstra, u. lafont, j. nijenhuis, e.m. kelder, and j.r.v. ommen, “atmospheric pressure process for coating particles using atomic layer deposition,” chemical vapor deposition, vol.15, pp.227-233, 2009. [14] r. cooper, h.p. upadhyaya, t.k. minton, m.r. berman, x. du, s.m. george, “protection of polymer from atomicoxygen erosion using al2o3 atomic layer deposition coatings,” thin solid films, vol.516, pp.4036-4039, 2008. [15] c.a. wilson, r.k. grubbs, and s.m. george, “nucleation and growth during al2o3 atomic layer deposition on polymers,” chemistry of materials, vol.17, pp.56255634, 2005. [16] s.d. elliot, “predictive process design: a theoretical model of atomic layer deposition,” computational materials science, vol. 33., pp.20-25, 2005. [17] o. nilsen, o.b. karlsen, a. kjekshus, h. vjellvag, “simulation of growth dynamics in atomic layer deposition. part i. amorphous films,” thin solid films, vol. 515, pp.4527-4537, 2007. [18] s.m. goerge, “atomic layer deposition: an overview,” chemical reviews, vol. 110, pp.111-131, 2010. [19] k. lahtinen., p. maydannik., p. johansson., t. kääriäinen, d.c. cameron., j. kuusipalo, “utilization of continuous atomic layer deposition process for barrier enhancement of extrusion-coated paper,” surface & coatings technology, vol.205, pp.39163922, 2011. [20] n.d. hoivik., j.w. elam., r.j. linderman., v.m. bright., s.m. george., y.c. lee., “atomic layer deposited protective coatings for micro-electromechanical systems,” sensors and actuators a, vol.103, pp.100-108, 2003. [21] m. leskela, m. ritala, “atomic layer deposition: from precursors to thin structures,” thin solid films, vol.409, pp.138-146, 2002. [22] f. werner, w. stals, r. görtzen, b. veith, r. brendel, j. schmidt, “high-rate atomic layer deposition of al2o3 for the surface passivation of si solar cells,” energy procedia, vol.8, pp.301-306, 2011. [23] s.j. noh, s.k. lee, e.h. kim, y.j. kong, “construction of an atomic layer deposition system for nano-device application,” current applied physics, vol.6, pp.171-173, 2006. [24] j. kim, k. chakrabarti, j. lee, k.-y. oh, c. lee, “effect of ozone on the properties of the al2o3 thin films prepared by atomic layer deposition,” materials chemistry and physics, vol.78, pp.733-738, 2003. [25] r. puurunen, “preparation by atomic layer deposition and characterization of catalyst supports surfaced with aluminium nitride,” academic dissertation, helsinki university of technology, finland, 2002. [26] r.l. puurunen, “surface chemistry of atomic layer deposition: a case study for the trimethylaluminum/water process,” journal of applied physics, vol.97, article number: 121301, 2005. [27] a.k. roy, w. baumann, l. könig, g. baumann, s. schulze, m. hietschold, t. mäder, d.j. nestler, b. wielage, w.a. goedel, “atomic layer deposition (ald) as a coating tool for reinforcing fibers,” analytical and bioanalytical chemistry, vol.396, pp.1913-1919, 2010. [28] y.zhang., d. sehjete., a. abdulagatov., z. gibbs., a. cavanagh., r. yang., s. george., y.-c. lee., “investigation of the defect density in ultra-thin al2o3 films grown using atomic layer deposition,” surface & coatings technology, vol.205, pp.33343339, 2011. [29] y.-h. kim, y.-h. choi, j.-h. kim, j.-k. park, w.-t. ju, k.-h. paek, y.-s. hwang, “characterizations of atmospheric pressure ejected plasma sources,” surface and coating technology, vol.174, pp.535-540, 2003. [30] http://www.cambridgenanotech.com/cnprupl oads/ald tutorial.pdf. e. riyanto et al. / mechatronics, electrical power, and vehicular technology 03 (2012) 65-72 72 [31] c.a. wilson., j.a. mccormick., a.s. cavanagh., d.n. goldstein., a.w. weimer., s.m. george., “tungsten atomic layer deposition on polymers,” thin solid films, vol.516, pp.6175-6185, 2008. [32] f.h. fabreguette., s.m. george., “letter xray mirrors on flexible polymer substrates fabricated by atomic layer deposition,” thin solid films, vol.515, pp.7177-7180, 2007. [33] http://depts.washington.edu/cmditr/mediawi ki/index.php?title=atomic_layer_depositio n_ald. [34] m. putkonen., l. niinistö., “organometallic precursors for atomic layer deposition,” topics in organometallic chemistry, vol.9, pp.135-145, 2005. [35] m. houssa, high-k gate dielectrics, institute of physics publishing, bristol and philadelphia, (2004). [36] t.o. kääriäinen, p. maydannik, d.c. cameron, k. lahtinen, p. johansson, j. kuusipalo, “atomic layer deposition on polymer based flexible packaging materials: growth characteristics and diffusion barrier properties,” thin solid films, vol.519, pp.3146-3154, 2011. [37] h. kim, h.-b.-r. lee, and w.-j. maeng, “applications of atomic layer deposition to nanofabrication and emerging nanodevices,” thin solid films, vol.517, pp.2563-2580, 2009. [38] .d. groner, f.h. fabreguette, j.w. elam, and s.m. george, “low-temperature al2o3 atomic layer deposition,” chemistry of materials, vol.16, pp.639-645, 2004. [39] j.d. ferguson, a.w. weimer, and s.m. goerge, “atomic layer deposition of al2o3 films on polyethylene pasrticles,” chemistry of materials, vol.16, pp.56025609, 2004. [40] g.k. hyde, g. scarel, j.c. spagnola, q. peng, et.al, “atomic layer deposition and abrupt wetting transition on nonwoven polypropylene and woven cotton fabrics,” langmuir, vol.26, pp.2550-2558, 2010. [41] j.s. jur, j.c. spagnola, k. lee, b. gong, and g.n. parsons, “temperature-dependent subsurface growth during atomic layer deposition on polypropylene and cellulose fibers,” langmuir, vol.26, pp.8239-8244, 2010. [42] t. hirvikorpi, m.v.-nissi, j. nikkola, a. harlin, m. karppinen, “thin al2o3 barrier coating onto temperature-sensitive packaging materials by atomic layer deposition,” surface and coating technology, vol.205, pp.5088-5092, 2011. [43] t.m. mayer., j.w. elam., p.g. kotula., r.s. goeke., s.m. george., “atomic layer deposition of wear-resistant coatings for microelectromechanical devices,” applied physics letter, vol.82, pp.2883-2885, 2003. [44] j.g. korvink, and a. greiner., semiconductors for micro and nanotechnology-an introduction for engineers, wiley vch, weinheim, germany, 2002. [45] d.m. tanner., t.b. parson., a.d. corwin., j.a. walraven., j.w. wittwer., b.l. boyce., s.r. winzer., “invited paper science-based mems reliability methodology,” microelectronics reliability, vol.47, pp.1806-1811, 2007. [46] d.m. tanner., “mems reliability: where are we now?,” microelectronics reliability, vol.49, pp.937-940, 2009. [47] m. bao., w. wang., “future of microelectromechanical systems (mems),” sensors and actuators a, vol.56, pp.135141, 1996. [48] s.m. spearing., “materials issues in microelectromechanical systems (mems),” acta materialia, vol.48, pp.179-196, 2000. [49] r. doering, y. nishi, handbook of semiconductor manufacturing technology, crc press, second edition, chapter 14, page.14-1 – 14-37. [50] m. palacio., b. bushan., “wear detection of candidate mems/nems lubricant films using atomic force microscopy-based surface potential measurements,” scripta materialia, vol.57, pp.821-824, 2007. [51] i.s.y. ku., t. reddyhoff., a.s. holmes., h.a. spikes., “wear of silicon surfaces in mems,” wear, vol.271, pp.1050-1058, 2011. [52] t.w. scharf., s.v. prasad., m.t. dugger., p.g. kotula., r.s. goeke., r.k. grubbs., “growth, structure, and tribological behavior of atomic layer-deposited tungsten disulphide solid lubricant coatings with applications to mems,” acta materialia, vol.54, pp.4731-4743, 2006. [53] t. aaltonen, atomic layer deposition of noble metal thin films, academic dissertation, university of helsinki, helsinki, finland, (2005). mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.81-88 the performance of eeg-p300 classification using backpropagation neural networks arjon turnip *, demi soetraprawata technical implementation unit for instrumentation development indonesian institute of sciences kompleks lipi gd. 30, jl. sangkuriang, bandung, indonesia received 09 november 2012; received in revised form 19 february 2013; accepted 25 february 2013 published online 24 december 2013 abstract electroencephalogram (eeg) recordings signal provide an important function of brain-computer communication, but the accuracy of their classification is very limited in unforeseeable signal variations relating to artifacts. in this paper, we propose a classification method entailing time-series eeg-p300 signals using backpropagation neural networks to predict the qualitative properties of a subject’s mental tasks by extracting useful information from the highly multivariate non-invasive recordings of brain activity. to test the improvement in the eeg-p300 classification performance (i.e., classification accuracy and transfer rate) with the proposed method, comparative experiments were conducted using bayesian linear discriminant analysis (blda). finally, the result of the experiment showed that the average of the classification accuracy was 97% and the maximum improvement of the average transfer rate is 42.4%, indicating the considerable potential of the using of eeg-p300 for the continuous classification of mental tasks. keywords: eeg-p300 classification, backpropagation neural networks, blda, accuracy, transfer rate. i. introduction for several years, people have sought for a non muscular channel between the brain and the out world so that they can control peripherals by thinking. with the production of advanced bioinstruments for recording and amplifying the signals as well as cheap and powerful personal computers, this dream was realized and braincomputer interface (bci) was developed. signals from the brain are acquired by electrodes on the scalp and be processed to extract specific features that reflect the user’s intentions. the bci must select and extract features that can be controlled by the user and translate those features into device commands correctly and efficiently. for this purpose, brain activity must be monitored. today there existed various techniques to accomplish these problems [1–8]. among these methods, almost all bcis reported the data having been based on eeg. there are two main approaches to detect the user’s commands from eeg. in the first approach the subject concentrates on a few mental tasks. the different concentration on each mental task will produce a different eeg pattern. the bci (especially the classifier) can then be trained to classify those patterns. several bcis system (e.g. [1, 9-14]) are based on the type of the pattern recognition approach. in the second approach the user has to learn the self-regulation of his or her eeg responses, for example to change therhythm amplitude [12]. there are various properties in eeg that can be used as a base for bci such as rhythmic brain activity (i.e., delta, theta, alpha, and beta) [7], event-related potentials (erps), event-related desynchronization (erd) and event-related synchronization (ers) [1, 9, 13]. however, the present study is focused on the using of erp properties. the erp most commonly utilized is p300. p300, as noted in the journal science, was discovered originally by samuel sutton, et al. [15], and represented the unpredictable stimuli presented in an oddball paradigm, in which lowprobability targets were mixed with highprobability ones. for this paradigm, the subject is * corresponding author. phone: +62-22-2503053, fax: +62-22-2504577 e-mail: jujhin@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.81-88 a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 82 told to respond a rare stimulus that occurs randomly and infrequently among other, frequent stimuli [7]. the presence, magnitude, topography, and time of the response signal are often used as metrics of cognitive function in the decision of making processes. in this paper we propose a classification method for time series eeg signals that incorporates with a backpropagation neural network (bpnn), which has been well developed in the field of speech recognition. in order to examine the performance (i.e., accuracy and transfer rate) improvements of the proposed eeg classification method, comparative experiments were conducted using bayesian linear discriminant analysis (blda). the structure of the paper is as follows. in section 2, the subject population, the experiments that were conducted, and the methods used for data preprocessing are described. classification using the bpnn model is explained in section 3. results and discussions are presented in section 4. conclusions are drawn in section 5. ii. methods the data set used in this study was obtained from the website of the epfl bci group (http://bci.epfl.ch/p300) [6]. the data have been recorded according to the 10-20 international standards from the 32 electrode configurations [13]. each recorded signal has a length of 820 samples with a sampling rate of 2048 hz. a sixchoice signal paradigm was tested using a population of five disableand four able-bodied subjects. the subjects were asked to count silently the number of times a prescribed image flashed on a screen. four seconds after a warning tone, six different images (a television, a telephone, a lamp, a door, a window, and a radio) were flashed in a random order [6]. each of the image flash lasted for 100 ms, and for the following 300 ms no image was flashed (i.e., the inter-stimulus interval was 400 ms). each subject completed four recording sessions. each of the sessions consisted of six runs with one run for each of the six images. the duration of one run was approximately one minute and the duration of one session, including set up of electrodes and short breaks between runs, was approximately 30 min. our goal is to discriminate all possible combinations of the pairs of mental tasks from each other using the corresponding eeg signals. before the classification and validation are performed, several preprocessing operations, including down sampling, windsorizing, scaling, feature vector construction, and desired output construction, were applied to the data. the eeg was down sampled from 2048 hz to 32 hz by selecting each 64th sample from the band passfiltered data. not all of the measured eeg signals are electrical activity of the brain. many potential changes detected in eeg are from other sources. these changes are called artifacts, and their sources can be the equipment or the subject. the data sets consist of the data matrix, events matrix, stimuli, targets, and targets counted. the data matrix contained the raw eeg. the events matrix contained the time-points at when the flashes (events) occurred. the stimulus is an array containing a sequence of flashes. the entries had value between 1 and 6, and each entry corresponded to a flash of one image on the screen. the variable target contained the index of the image in which the user focusing on. for example, if a target equaled three, the user counted the number of the flashes of the lamp. together with the number of events, this variable can be used to determine if the user was actually concentrating. the extracted features then were fed into the recurrent multilayered perceptro neural networks with decent optimization algorithm. for the test, the hold out method was used, in which 75% of the data is used for training and 25% for test. it is difficult to compare the performances of the bci systems, because the pertinent studies present the results in different ways. however, in the present study, the comparison is made based on the accuracy and the transfer rate. perhaps, accuracy is the most important aspect in any bci. if a bci will be used in control applications, the accuracy is obviously crucial. furthermore, the transfer rate is also very important. the speed of a particular bci is affected by the trial length, how long one selection will take. this time should be short to enhance a bci’s communication effectiveness. the amount of information communicated per time unit (the transfer rate) is a standard measure of a communication system. the transfer rate depends on both the speed and the accuracy of the selection. if a trial has n possible selections and each selection has the same probability to be the desired selection, and if p denotes the probability that the desired choice is actually selected, the probability for the remaining (undesired) selections being selected will be (1-p)/(n-1). the bit rate (bits/trial) of each selection then can be expressed as [6, 12, 14, 16]: 𝑏𝑏 = 𝑙𝑙𝑙𝑙𝑙𝑙2 (𝑁𝑁) + 𝑃𝑃𝑙𝑙𝑙𝑙𝑙𝑙2 (𝑃𝑃) + (1 − 𝑃𝑃𝑃𝑃𝑙𝑙𝑙𝑙𝑙𝑙2 1−𝑃𝑃𝑁𝑁−1 (1) the transfer rate (bits per minute) is equal to b multiplied by the average speed of selection s (trial per minute, which is equal to the reciprocal a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 83 of the average time required for one selection). therefore, based on the data sets information, the desired output signal is developed. in the present study, the algorithm developed using the bpnn model was used for classification. for four of the disabled subjects and four of the able-bodied subjects, classification accuracies and transfer rates obtained are significantly beyond those reported previously by hoffmann, vesin, and ebrahimi [6], sellers, et al. [12], and wolpaw, et al. [14]. iii. backpropagation neural networks artificial neural networks have been proposed in the fields of information and neural sciences following the research in the mechanisms and structures of the brain. this has led the development of new computational models for solving complex problems such as pattern recognition, rapid information processing, learning and adaptation, classification, identification and modeling, speech, vision and control systems [17-21]. the network architecture includes statistical and dynamical, single and multilayer as well as feedback (recurrent) networks has been presented. one of the most difficult problems that still take great scientists interest is learning. special attention has been paid to the most efficient learning algorithm for multilayer networks, namely backpropagation. the backpropagation algorithm allows exponential acquisition of input-output mapping knowledge within multilayer networks. if a pattern is submitted and its classification is determined to be erroneous, the current least mean-square classification error is reduced. the error is expressed as [22]: 𝐸𝐸𝑗𝑗 = 1 2 ∑ �𝑑𝑑𝑗𝑗 − 𝑦𝑦𝑗𝑗 �𝑥𝑥𝑖𝑖, 𝑤𝑤𝑖𝑖𝑗𝑗 �� 𝑇𝑇 𝑛𝑛 𝑖𝑖=1 �𝑑𝑑𝑗𝑗 − 𝑦𝑦𝑗𝑗 𝑥𝑥𝑖𝑖 , 𝑤𝑤𝑖𝑖𝑗𝑗 (2) where 𝑑𝑑𝑗𝑗 denotes the desired output of node j corresponding to input 𝑥𝑥𝑖𝑖 , 𝑛𝑛 is the number of training patterns and 𝑦𝑦𝑗𝑗�𝑥𝑥𝑖𝑖, 𝑤𝑤𝑖𝑖𝑗𝑗 � denotes the vector output of the networks corresponding to input 𝑥𝑥𝑖𝑖 and weight matrix 𝑤𝑤 = �𝑤𝑤𝑖𝑖𝑗𝑗 �. during the association or classification phase, the trained neural network itself operates in a feed-forward manner. therefore the error will be a function of the weights of the input and the output layers. the backpropagation algorithm is a gradient descent method minimizing the mean square error between the actual and target outputs of a multilayer perceptron. using the sigmoid non linearity: 𝑓𝑓(𝑛𝑛𝑛𝑛𝑛𝑛𝑖𝑖) = 1 1−𝑛𝑛−𝑛𝑛𝑛𝑛𝑛𝑛 (3) the backpropagation algorithm consists of some steps. first, initialize all weights and node offsets to small random values. second, present continuous input vector 𝑥𝑥𝑖𝑖 and specify desired output 𝑑𝑑𝑗𝑗 . the output vector elements are set to zero values except for the vector that correspond to the class of the current input. third, calculate the actual output vector y using the sigmoid non linearity. fourth, adjust the weights by the following equation: 𝑤𝑤𝑖𝑖𝑗𝑗 (𝑛𝑛 + 1) = 𝑤𝑤𝑖𝑖𝑗𝑗 (𝑛𝑛) + η δ j𝑥𝑥𝑖𝑖 (4) where 𝑑𝑑𝑗𝑗 is the sensitivity of node 𝑗𝑗. fifth, repeat the steps from the second step. a better approach is a cross-validation technique, which stops training when the error on a separate validation set reaches a minimum. figure 1 shows the structure of the bpnn-based classification algorithm. we observe records a vector of eeg signals 𝑥𝑥(𝑛𝑛) = [𝑥𝑥1 (𝑛𝑛), 𝑥𝑥2 (𝑛𝑛), … , 𝑥𝑥𝑚𝑚 (𝑛𝑛)]𝑇𝑇 from a multiple-input/multiple-output nonlinear dynamical system. the objective is to find an inverse system, termed a reconstruction system with backpropagation neural networks (bpnn), in order to estimate the primary input source of brain signals 𝑠𝑠(𝑛𝑛) = [𝑠𝑠1 (𝑛𝑛), 𝑠𝑠2 (𝑛𝑛), … , 𝑠𝑠𝑛𝑛 ]𝑇𝑇 corresponding to particular stimulus, which are represented by 𝑦𝑦(𝑛𝑛) = [𝑦𝑦1 (𝑛𝑛), 𝑦𝑦2 (𝑛𝑛), … , 𝑦𝑦𝑛𝑛 (𝑛𝑛)]𝑇𝑇. this program is used to train a set of prototypes from the recorded data. each prototype corresponds to one particular stimulus. the classifier then will use these prototypes in the classification of the eeg signals. in order to train a new set of prototypes, the processed data of one recording is loaded into the program. the stimuli are labeled in the data. the data is then divided into training and validation sets in such a way that the three first sessions go to the training set and the one remaining session goes to the validation set. the thresholds will affect how figure 1. structure of bpnn-based classification algorithm a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 84 easily the signals (data sets) are classified as belonging to one of the stimuli and how easily they are rejected. the classifier computes probability values for a signal belonging to each of the stimuli included in the data set. then the highest probability value is chosen, and this value is compared to the probability threshold. if the value exceeds the threshold, the sample is classified to the corresponding stimuli, otherwise it is rejected. after the number of the iterations and the thresholds are adjusted, the training of the new prototypes can begin. during the training, a new set of prototypes are trained in each iteration. after the training finished, the weight matrices corresponding to each iteration are reviewed. the best prototypes then can be saved to be used later in the validation set. iv. result and discussion the ability to measure and classify single-trial responses from specific brain regions has important theoretical and practical implications for both basic and applied research. for brain research, the ability to measure single-trial erps is one of the important steps toward the understanding of how the relative timing of neuronal activity can affect learning and how memory of a particular experience can be encoded rapidly with a single or very few exposures. in clinical applications, the ability to obtain such measures in a computationally efficient manner could allow functionally meaningful brain signals to be extracted and used to generate better input and feedback signals for brain computer interfaces. in the present study, a bpnn classifier was used. in order to cope with nonlinearly separable problems, additional layers of neurons placed between the input layer and the output neuron are needed, leading to the multilayer perceptron architecture. at the outset, the structure of the network is chosen, after the validation pattern appears in the graph window, and the network initialization values are introduced. each subsequent layer has a weight coming from the previous layer. the performance is measured according to the specified performance function such as mean square error. the convergence of the mean square errors to zero, shown in figure 2, verifies the performance of the network. the data sets for subject 5 were not included in the simulation since the subject misunderstood the instructions given before the experiment. comparative plots of the classification accuracies and transfer rates (obtained with the bpnn and blda methods and averaged over four sessions based on the eight electrode configurations) for the disable (s1 s4) and able-bodied subjects (s6 s9) are respectively depicted in figure 3 and figure 4. all of the subjects (with bpnn), except the subjects 6 and 9, achieved an average classification accuracy of 100% after eight blocks of stimulus presentations are averaged (i.e., 19.2 s). however, subject 9, compared with blda, still achieved an average classification accuracy of 100% after sixteen blocks of stimulus presentations are averaged. the reason for the poorer performance of subject 9 might be fatigue. subject 6 reported that he accidentally concentrated on the wrong stimulus during one run in session 1 [6]. shown alongside the classification accuracies using bpnn for all of the subjects, in table 1, are the corresponding 95% confidence intervals. according to the individual subject performances in table 2, subject 1 had the best improvement (4.9%) of the average classification accuracy over all of the experiments. moreover, this subject showed an improvement for all of the configurations. however, subject 8 had the worst improvement (0.3%) of average classification accuracy over all of the experiments (table 2). the transfer rates corresponding to the classification accuracies for the different electrode configurations (i.e. consisting of 4, 8, 16, and 32 electrodes) using both classification algorithms (bpnn and blda) combined, were tested. the results showed that a significant improvement in classification accuracy (for all of the configurations) and average transfer rate (except for configuration iv with 32 electrodes) was obtained. the maximum average transfer rate, mean transfer rate, and standard deviations for all of the combinations of classification algorithms and electrode configurations are listed in table 3. figure 2. network’s performance according to mean squares errors a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 85 table 3 shows that the maximum average transfer rates for subjects 6 and 7 in configuration iii, obtained with the blda algorithm, were better than those obtained with the bpnn algorithm. however, the maximum average transfer rates (i.e., s1-s4, s6-s9, and all of the subjects) obtained with the bpnn algorithm were better that those obtained with the blda 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) bpnn blda subject 4 accuracy transfer rate 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) subject 2 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 3 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 1 figure 3. comparison of classification accuracy and transfer rate plots (averaged over four sessions based on eight electrode configurations) obtained with bpnn and blda for disabled subjects (subjects 14) 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) bpnn blda subject 9 accuracy transfer rate 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 t ra ns fe r ra te ( bi ts /m in ) subject 7 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) time (s) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 8 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 a cc ur ac y (% ) 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 0 5 10 15 20 25 30 35 40 45 50 subject 6 figure 4. comparison of classification accuracy and transfer rate plots (averaged over four sessions based on eight electrode configurations) obtained with bpnn and blda for able-bodied subjects (subjects 69) a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 86 algorithm. these improvements can be seen in table 4. in the work of hoffmann, et al. (2008), the maximum average transfer rate was about 15.9 bits/min for the disabled subjects and 29.3 bits/min for the able-bodied subjects. in the present study, improvements of the maximum average transfer rates for the same electrode configurations are achieved (i.e. about 21.4 bits/min for the disabled subjects and 35.9 bits/min for the able-bodied subjects). table 1. average classification accuracy (%) subject bpnn-4 bpnn-8 bpnn-16 bpnn-32 blda-4 blda-8 blda-16 blda-32 s1 89.8 92.7 93.7 92.1 82.3 87.9 87.2 91.3 s2 90.8 94.3 95.6 92.1 80.0 91.7 91.7 92.1 s3 97.5 98.6 98.8 97.7 95.8 97.3 97.3 97.3 s4 96.9 96.9 97.2 97.6 93.5 95.2 97.1 97.9 s6 92.5 92.8 94.2 92.7 90.6 91.3 91.9 92.7 s7 98.5 97.3 97.4 99.1 93.5 95.8 98.8 98.8 s8 98.8 97.9 98.7 99.8 95.8 98.5 99.6 100 s9 94.1 95.9 96.8 95.2 85.6 90.2 96.3 95.6 average (s1–s4) 93.8±4.0 95.6±2.6 96.3±2.2 94.9±3.2 87.9±7.9 93.0±4.1 93.3±4.8 94.6±3.5 average (s6-s9) 96.0±3.1 95.9±2.3 96.8±1.9 96.7±3.3 91.4±4.4 94.0±3.9 96.6±3.5 96.8±3.3 average (all) 94.9±3.5 95.8±2.3 96.5±1.9 95.8±3.2 89.7±6.2 93.5±3.8 95.0±4.3 95.7±3.3 table 2. improvement of average classification accuracy (%) subject/ configuration i ii iii iv average (i–iv) s1 7.5 4.8 6.5 0.8 4.9 s2 10.8 2.6 3.9 0.0 4.3 s3 1.7 1.3 1.5 0.4 1.2 s4 3.4 1.7 0.1 -0.3 1.2 s6 1.9 1.5 2.3 0.0 1.4 s7 5.0 1.5 -1.4 0.3 1.4 s8 3.0 -0.6 -0.9 -0.2 0.3 s9 8.5 5.7 0.5 -0.4 3.6 average (s1–s4) 6.7 2.8 3.2 0.2 3.2 average (s6-s9) 5.0 2.2 0.1 -0.1 1.8 average (all) 5.8 2.5 1.6 0.1 2.5 table 3. maximum average transfer rate subject bpnn-4 bpnn-8 bpnn-16 bpnn-32 blda-4 blda-8 blda-16 blda-32 s1 11.2 12.5 14.3 14.9 8.8 8.8 7.7 13.0 s2 9.7 13.0 15.4 12.4 6.8 10.8 11.4 11.2 s3 25.0 35.0 38.3 24.7 21.9 24.7 24.7 21.9 s4 19.0 25.2 28.9 31.3 14.9 19.3 21.9 29.8 s6 26.0 27.0 24.3 34.1 25.9 25.9 25.9 34.1 s7 32.3 38.3 35.0 41.1 22.3 22.3 38.7 38.7 s8 43.8 51.4 57.1 64.6 38.7 49.4 56.0 64.6 s9 18.7 27.0 30.8 26.5 17.0 19.3 22.3 17.0 average (s1–s4) 16.2±7.2 21.4±10.8 24.2±11.5 20.8±8.8 13.1±6.8 15.9±7.5 16.4±8.2 19.0±8.6 average (s6-s9) 30.2±10.6 35.9±11.6 36.8±14.2 41.6±16.5 26.0±9.2 29.3±13.7 35.7±15.2 38.6±19.7 average (all) 23.2±11.2 28.7±13.0 30.5±13.7 31.2±16.5 19.5±10.2 22.6±12.5 26.1±15.3 28.8±17.6 a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 87 v. conclusions the results presented in this study show that, compared with the blda algorithm, a better extraction result can be obtained by using the backpropagation neural networks (bpnn) algorithm for single-trial erps based on the p300 component from specific brain regions. with bpnn, the data indicate that a p300-based bci system can communicate for the disable-and able-bodied subjects respectively at the rate of 21.4 bits/min and 35.9 bits/min. the average of 100% classification accuracy is achieved after eight blocks for disabled subjects and after five blocks for able-bodied subjects. these results indicate that the system allowed several disabled users to achieve transfer rates significantly beyond those reported previously in the literatures. however, if in the future many subjects are going to be tested and computation time is an issue, the bpnn model will appear to be the best choice. to improve our results, we are currently investigating the effect of averaging the output of the classifier over the consecutive windows as well as the effects of other preprocessing methods in artifact-effect reduction. acknowledgement this research was funded by the thematic program year of 2013 (no. 3425.001.013) through the unit of technical implementation for instrumentation development division (deputy for scientific services), indonesian institute of sciences, indonesia. references [1] e. donchin, et al. the mental prosthesis: assessing the speed of a p300-based brain– computer interface. ieee trans. rehabil. eng., 2000, 8(2): 174-179. [2] p. jezzard, et al. functional mri: an introduction to the methods[m]. oxford university press, 2001. [3] m. hamalainen, et al. magnetoencephalography theory, instrumentation, and applications to noninvasive studies of the working human brain. reviews of modern physics, 1993, 65(2): 413-497. [4] b. e. hillner, et al. impact of positron emission tomography/computed tomography and positron emission tomography (pet) alone on expected management of patients with cancer: initial results from the national oncologic pet registry. journal of clinical oncology, 2008, 26(13): 2155-2161. [5] f. jouret, et al. single photon emissioncomputed tomography (spect) for functional investigation of the proximal tubule in conscious mice. ajp renal physiology, 2010, 298(2): 454-460. [6] u. hoffmann, et al. an efficient p300-based brain–computer interface for disabled subjects. journal of neuroscience methods, 2008, 167(1): 115-125. [7] e. niedermeyer and f. l. da silva. electroencephalography [m]. 5th ed. lippincott williams & wilkins, 2005. [8] e. m. izhikevich. dynamical systems in neuroscience: the geometry of excitability and bursting [m]. the mit press, cambridge, massachusetts, london, england, 2007. [9] d. huang, et al. decoding human motor activity from eeg single trials for a discrete two-dimensional cursor control. journal of neural engineering, 2009, 6(4): 046005. [10] d. liu, z. pang, and s. r. lloyd. a neural network method for detection of obstructive sleep apnea and narcolepsy based on pupil table 4. improvement of maximum average transfer rate (%) subject/ configuration i ii iii iv average (i–iv) s1 27.3 42.0 85.7 14.6 42.4 s2 42.6 20.4 35.1 10.7 27.2 s3 14.2 41.7 55.1 12.8 30.9 s4 27.5 30.6 32.0 5.0 23.8 s6 0.4 4.2 -6.2 0.0 -0.4 s7 44.8 71.7 -9.6 6.2 28.3 s8 13.2 4.0 2.0 0.0 4.8 s9 10.0 39.9 38.1 55.9 36.0 average (s1–s4) 23.9 34.7 47.7 9.6 29.0 average (s6-s9) 16.2 22.6 3.1 7.7 12.4 average (all) 19.0 26.9 16.9 8.3 17.8 a. turnip and d. soetraprawata / mechatronics, electrical power, and vehicular technology 04 (2013) 81-88 88 size and eeg. ieee trans. neural netw., 2008, 19(2): 308-318. [11] f. nijboer, et al. a p300-based braincomputer interface for people with amyotrophic lateral sclerosis. clinical neurophysiology, 2008, 119(8): 1909-1916. [12] e. w. sellers, et al. a p300 event-related potential brain–computer interface (bci): the effects of matrix size and inter stimulus interval on performance. biological psychology, 2006, 73(3): 242-252. [13] b. o. peters, et al. automatic differentation of multichannel eeg signals. ieee trans. biomed. eng., 2001, 48(1): 111-116. [14] j. r. wolpaw, et al. brain–computer interface technology: a review of the first international meeting. ieee trans. rehabil. eng., 2000, 8(2): 164-173. [15] s. sutton, et al. evoked potential correlates of stimulus uncertainty. science, 1965, 150(700): 1187-1188. [16] d. j. mcfarland, et al. brain-computer interface (bci) operation: optimizing information transfer rates. biological psychology, 2003, 63(3): 237-251. [17] s. jaiyen, et al. a very fast neural learning for classification using only new incoming datum. ieee trans. neural netw., 2010, 21(3): 1750-1761. [18] y. washizawa. feature extraction using constrained approximation and suppression. ieee trans. neural netw., 2010, 21(2): 201-210. [19] s. ozawa, et al. a multitask learning model for online pattern recognition. ieee trans. neural netw., 2009, 20(3): 430-445. [20] s.s. ge, et al. hand gesture recognition and tracking based on distributed locally linear embedding. image and vision computing, 2008, 26(12): 1607-1620. [21] y. yang, et al. facial expression recognition and tracking for intelligent human-robot interaction. intelligent service robotics. 2008, 1(2): 143-157. [22] d. graupe. princiles of artificial neural networks[m]. 2nd ed. world scientific publishing co. pte. ltd. vol. 6, 2007. introduction methods backpropagation neural networks result and discussion conclusions mev journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mev.lipi.go.id p-issn 2087-3379 vi journal of mechatronics, electrical power, and vehicular technology international peer reviewers acknowledgement the editor of mev would like to thank the wisdom and advice of many individuals who dedicated their considerable time and expertise in safeguarding the quality and high standard of academic integrity of the journal. we are greatly indebted to the expertise, dedication, and expeditious response of the following individuals for reviewing at least one and, in some cases, many manuscripts for the journal from early 2010 until today. prof. ir. jamasri, ph.d. department of mechanical and industrial engineering, gadjah mada university, indonesia prof. dr. ir. suhono h supangkat, m.eng., cgeit. school of electrical engineering and informatics, institut teknologi bandung, indonesia prof. dr. ir. zainal abidin mechanical and aerospace engineering, institut teknologi bandung, indonesia prof. dr. ir. r. danardono agus sumarsono, dea., pe. department of mechanical engineering, university of indonesia, indonesia prof. sasongko pramono hadi department of electrical engineering, gadjah mada university, indonesia prof. juan carlos alvarez dept. electrical engineering, university of oviedo, spain prof. dr. murat lüy department of electrical and electronic engineering, kırıkkale universitesi, turkey prof. istván patkó óbuda university, budapest, hungary dr. ir. iman k reksowardojo mechanical and aerospace engineering, institut teknologi bandung, indonesia dr. irhan febijanto, m.eng research center for sustainable production system and life cycle assessment brin, indonesia dr. narankhuu jamsran thomas air llc, mongolia dr. ir. edi leksono, m.eng. engineering physics, institut teknologi bandung, indonesia ahmad agus setiawan, s.t., m.sc., ph.d. department of engineering physics, faculty of engineering, gadjah mada university, indonesia dr. larissa lorenz bauhaus luftfahrt e.v, germany dr. si steve li electromechanical system development, general electric global research centre, united states anusua ghosh school of electrical and information engineering, university of south australia, australia ir. arko djajadi, ph.d. swiss german university, indonesia ir. endra joelianto, ph.d. engineering physics, institut teknologi bandung, indonesia aji prasetya wibawa, ph.d. dept of electrical engineering, state university of malang, indonesia dr. ir. rizqon fajar, m.sc. research center for transportation technology brin, indonesia dr. tushar ahmed school of aerospace, mechanical and mechatronic engineering, the university of sydney, australia dr. endra pitowarno, m.eng. electronics engineering, polytechnic institute of surabaya (eepis) , indonesia hendro nurhadi, dipl.ing., ph.d. department of mechanical engineering institut teknologi sepuluh nopember, indonesia dr. trina fizzanty research center for education brin, indonesia anna maria sri asih, s.t., m.m., m.sc., ph.d. mechanical & industrial engineering department, gadjah mada university, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii dr.eng. anindito purnowidodo, m.eng. mechanical engineering dept., brawijaya university, indonesia dr. adha imam cahyadi department of electrical engineering, gadjah mada university , indonesia dr. wahyudi sutopo, s.t., m.si. industrial engineering, universitas sebelas maret surakarta, indonesia dr. fendy santoso autonomous system laboratory, school of engineering and information technology, the university of new south wales, australia dr. dimas anton asfani, s.t., m.t. department of electrical engineering institut teknologi sepuluh nopember, indonesia dr. ir. feri yusivar, m.eng. department of electrical engineering, university of indonesia, indonesia dr. agfianto eko putra, m.sc. department of computer and electronic science, gadjah mada university, indonesia dr. feblil huda, s.t., m.t. department of mechanical engineering, universitas riau, indonesia pudji irasari, m.sc.rer.nat. research center for energy conversion and conservation brin, indonesia dr. sunit hendrana research center for physics lipi, indonesia dr. eka firmansyah department of electrical engineering and information technology, gadjah mada university, indonesia dr. arwindra rizqiawan, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia laksono kurnianggoro, ph.d. department of electrical engineering, university of ulsan, south korea yusie rizal, ph.d. cand. dept. engineering science, national cheng kung university, taiwan dr. yuliadi erdani politeknik manufaktur bandung, indonesia dr. joga dharma setiawan faculty of engineering, diponegoro university, indonesia dr. esa prakasa, m.t. research center for data and information sciences brin, indonesia dr. agus purwadi, m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia slamet riyadi, s. ds., m.ds., ph.d. product design department faculty of art and design, institut teknologi bandung, indonesia dr. ir. hilwadi hindersah school of electrical engineering and informatics, institut teknologi bandung, indonesia dr. widodo budi santoso research center for smart mechatronics brin, indonesia kadek heri sanjaya, ph.d. research center for smart mechatronics brin, indonesia suprapto, ph.d. departement of electronics engineering, yogyakarta state university, indonesia dr. ir. yoyon ahmudiarto, m.sc. research center for energy conversion and conservation brin, indonesia dr.-ing. moch ichwan research centre for electrical power and mechatronics – lipi, indonesia dr. edwar yazid research center for smart mechatronics brin, indonesia dr. eng. handityo aulia putra department of computer engineering, keimyung university, korea, republic of dr. caecilia sri wahyuning department of industrial engineering, institut teknologi nasional, indonesia alexander christantho budiman, ph.d. research center for transportation technology brin, indonesia dr. rina ristiana research center for transportation technology brin, indonesia dr. anto tri sugiarto, m.eng. research center for smart mechatronics brin, indonesia dr. ary setijadi prihatmanto, s.t., m.t. school of electrical engineering and informatics, institut teknologi bandung, indonesia dr. eng. aam muharam, m.t. research center for transportation technology brin, indonesia dr.eng. edy riyanto, s.t. research center for advanced material brin, indonesia dr. anwar muqorobin, m.t. research center for energy conversion and conservation brin, indonesia bambang wahono, m.eng., ph.d. research center for smart mechatronics brin, indonesia ghalya pikra, m.t. research center for smart mechatronics brin, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 viii rifa rahmayanti, m.sc. research centre for electrical power and mechatronics – lipi, indonesia vita susanti, s.kom. research center for smart mechatronics brin, indonesia hendri maja saputra, m.t. research center for smart mechatronics brin, indonesia dr. natalita maulani nursam research center for electronics – brin, indonesia dr. joko hariyono, s.t., m.eng. government of yogyakarta special region, indonesia yusuf nur wijayanto, ph.d. research center for electronics – brin, indonesia dr. edi kurniawan, s.t., m.eng. research center for photonics brin, indonesia dr. deni shidqi khaerudini, s.si., m.eng. research center for advanced material brin, indonesia dr. irwan purnama, m.sc.eng. research center for smart mechatronics brin, indonesia achmad praptijanto, s.t., m.d.m research center for smart mechatronics brin, indonesia sunarto kaleg, m.t. research center for transportation technology brin, indonesia kristian ismail, m.t. research centre for electrical power and mechatronics – lipi, indonesia midriem mirdanies, m.t. research center for smart mechatronics brin, indonesia sapdo utomo, m.t. research centre for electrical power and mechatronics – lipi, indonesia erie martides, m.t. research center for advanced material brin, indonesia agus risdiyanto, m.t. research center for energy conversion and conservation brin, indonesia rudi darussalam, m.eng. research center for energy conversion and conservation brin, indonesia dr. hanif fakhrurroja, s.si., m.t. research center for smart mechatronics brin, indonesia aditya sukma nugraha, m.t. research centre for electrical power and mechatronics – lipi, indonesia ahmad rajani, m.eng. research center for energy conversion and conservation brin, indonesia amin, m.t. research center for transportation technology brin, indonesia maulana arifin, m.t. research center for energy conversion and conservation brin, indonesia budi azhari, m.eng. research center for smart mechatronics brin, indonesia henny sudibyo, m.eng. research center for energy conversion and conservation brin, indonesia andri joko purwanto, m.t. research center for smart mechatronics brin, indonesia andry masri, m.sn. department of product design, faculty of art and design, institut teknologi nasional, indonesia roni permana saputra, m.eng. research center for smart mechatronics brin, indonesia sudirja, m.t. research center for transportation technology brin, indonesia dr. eng. eka rakhman priandana, s.t., m.t. research center for energy conversion and conservation brin, indonesia dr. suyoto, m.t. research center for telecommunication – brin, indonesia oka mahendra, m.t research center for smart mechatronics brin, indonesia veny luvita, m.t. research center for environmental and clean technology brin, indonesia mulia pratama, s.t., m.eng. research center for smart mechatronics brin, indonesia asep nugroho, s.si, m.eng, m.sc. research center for smart mechatronics brin, indonesia jalu ahmad prakosa, s.si., m.eng. research center for photonics brin, indonesia dr. dyah kusuma dewi, s.t., m.t. research center for smart mechatronics brin, indonesia ridwan arief subekti, s.t., m.si. research center for energy conversion and conservation brin, indonesia dr. harry septanto m.t. research center for smart mechatronics brin, indonesia ass. prof. ir. april lia hananto, ph.d universitas buana perjuangan karawang, indonesia journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 ix publication ethics and malpractice statement journal of mechatronics, electrical power, and vehicular technology (hence mev) is a journal aims to be a leading international peer-reviewed platform and an authoritative source of information. we publish original research papers, review articles and case studies focused on mechatronics, electrical power, and vehicular technology as well as related topics that has neither been published elsewhere in any language, nor is it under review for publication anywhere. this following statement clarifies ethical behavior of all parties involved in the act of publishing an article in this journal, including the author, the editor, the reviewer, and the publisher (national research and innovation agency). this statement is based on cope’s best practice guidelines for journal editors. duties of authors 1. reporting standards: authors should present an accurate account of the original research performed as well as an objective discussion of its significance. researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation. a manuscript should contain sufficient detail and references to permit others to replicate the work. fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable. manuscripts should follow the submission guidelines of the journal. 2. originality and plagiarism: authors must ensure that they have written entirely original work. the manuscript should not be submitted concurrently to more than one publication unless the editors have agreed to co-publication. relevant previous work and publications, both by other researchers and the authors’ own, should be properly acknowledged and referenced. the primary literature should be cited where possible. original wording taken directly from publications by other researchers should appear in quotation marks with the appropriate citations. 3. multiple, redundant, or concurrent publications: author should not in general submit the same manuscript to more than one journal concurrently. it is also expected that the author will not publish redundant manuscripts or manuscripts describing same research in more than one journal. submitting the same manuscript to more than one journal concurrently constitutes unethical publishing behavior and is unacceptable. multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced 4. acknowledgement of sources: authors should acknowledge all sources of data used in the research and cite publications that have been influential in influential in determining the nature of the reported work. proper acknowledgment of the work of others must always be given. 5. authorship of the paper: the authorship of research publications should accurately reflect individuals’ contributions to the work and its reporting. authorship should be limited to those who have made a significant contribution to conception, design, execution or interpretation of the reported study. others who have made significant contribution must be listed as co-authors. in cases where major contributors are listed as authors while those who made less substantial, or purely technical, contributions to the research or to the publication are listed in an acknowledgement section. authors also ensure that all the authors have seen and agreed to the submitted version of the manuscript and their inclusion of names as co-authors. 6. disclosure and conflicts of interest: all authors should clearly disclose in their manuscript any financial or other substantive conflict of interest that might be construed to influence the results or interpretation of their manuscript. all sources of financial support for the project should be disclosed. 7. fundamental errors in published works: if the author discovers a significant error or inaccuracy in the submitted manuscript, then the author should promptly notify the journal editor or publisher and cooperate with the editor to retract or correct the paper. 8. hazards and human or animal subjects: the author should clearly identify in the manuscript if the work involves chemicals, procedures or equipment that have any unusual hazards inherent in their use. duties of editor 1. publication decisions: based on the review report of the editorial board, the editor can accept, reject, or request modifications to the manuscript. the validation of the work in question and its importance to researchers and readers must always drive such decisions. the editors may be guided by the policies of the journal's editorial board and constrained by such legal requirements as shall then be in force regarding libel, copyright infringement and plagiarism. the editors may confer with other editors or reviewers in making this decision. editors have to take responsibility for everything they publish and should have procedures and policies in place to ensure the quality of the material they publish and maintain the integrity of the published record. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 x 2. review of manuscripts: editor must ensure that each manuscript is initially evaluated by the editor for originality. the editor should organize and use peer review fairly and wisely. editors should explain their peer review processes in the information for authors and also indicate which parts of the journal are peer reviewed. editor should use appropriate peer reviewers for papers that are considered for publication by selecting people with sufficient expertise and avoiding those with conflicts of interest. 3. fair play: the editor must ensure that each manuscript received by the journal is reviewed for its intellectual content without regard to sex, gender, race, religion, citizenship, etc. of the authors. an important part of the responsibility to make fair and unbiased decisions is the upholding of the principle of editorial independence and integrity. editors are in a powerful position by making decisions on publications, which makes it very important that this process is as fair and unbiased as possible. 4. confidentiality: the editor must ensure that information regarding manuscripts submitted by the authors is kept confidential. editors should critically assess any potential breaches of data protection and patient confidentiality. this includes requiring properly informed consent for the actual research presented, consent for publication where applicable. 5. disclosure and conflicts of interest: the editor of the journal will not use unpublished materials disclosed in a submitted manuscript for his own research without written consent of the author. editors should not be involved in decisions about papers in which they have a conflict of interest duties of reviewers 1. confidentiality: information regarding manuscripts submitted by authors should be kept confidential and be treated as privileged information. they must not be shown to or discussed with others except as authorized by the editor. 2. acknowledgement of sources: manuscript reviewers must ensure that authors have acknowledged all sources of data used in the research. reviewers should identify relevant published work that has not been cited by the authors. any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. the reviewers should notify the journal immediately if they come across any irregularities, have concerns about ethical aspects of the work, are aware of substantial similarity between the manuscript and a concurrent submission to another journal or a published article, or suspect that misconduct may have occurred during either the research or the writing and submission of the manuscript; reviewers should, however, keep their concerns confidential and not personally investigate further unless the journal asks for further information or advice. 3. standards of objectivity: review of submitted manuscripts must be done objectively and the reviewers should express their views clearly with supporting arguments. the reviewers should follow journals’ instructions on the specific feedback that is required of them and, unless there are good reasons not to. the reviewers should be constructive in their reviews and provide feedback that will help the authors to improve their manuscript. the reviewer should make clear which suggested additional investigations are essential to support claims made in the manuscript under consideration and which will just strengthen or extend the work 4. disclosure and conflict of interest: privileged information or ideas obtained through peer review must be kept confidential and not used for personal advantage. reviewers should not consider manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the papers. in the case of double-blind review, if they suspect the identity of the author(s) notify the journal if this knowledge raises any potential conflict of interest. 5. promptness: the reviewers should respond in a reasonable time-frame. the reviewers only agree to review a manuscript if they are fairly confident, they can return a review within the proposed or mutually agreed time-frame, informing the journal promptly if they require an extension. in the event that a reviewer feels it is not possible for him/her to complete review of manuscript within stipulated time then this information must be communicated to the editor, so that the manuscript could be sent to another reviewer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xi crossmark policy page all articles published in mev receive a doi and are permanently published. this applies regardless of the outcome of the peer review that follows after publication. all content, including articles that have not (yet) passed peer review, is permanently archived in portico. all versions of all articles that have passed peer review will be archived in pubmed and elsewhere. authors can revise, change and update their articles by publishing new versions, which are added to the article’s history; however, the individual versions, once published, cannot be altered or withdrawn and are permanently available on the mev website. mev participates in the crossmark scheme, a multi-publisher initiative that has developed a standard way for readers to locate the current version of an article. by applying the crossmark policies, mev is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. clicking on the crossmark logo (at the top of each mev article) will give you the current status of an article and direct you to the latest published version; it may also give you additional information such as new referee reports. in order to maintain the integrity and completeness of the scholarly record, the following policies will be applied when published content needs to be corrected; these policies take into account current best practice in the scholarly publishing and library communities: correction to an article in traditional journals, where articles are peer reviewed before publication, corrections (or errata) are published to alert readers to errors in the article that became apparent following the publication of the final article. by contrast, articles in mev undergo peer review post publication and publication is not ‘final’ as new versions can be added at any stage. possible mistakes that come to light during the peer review process may be highlighted in the published referee reports, which are part of the article. authors can publish revised versions, and any errors that become apparent during peer review or later can be corrected through the publication of new versions. corrections and changes relative to the previous version are always summarized in the ‘amendments’ section at the start of a new version. retraction articles may be retracted for several reasons, including: • honest errors reported by the authors (for example, errors due to the mixing up of samples or use of a scientific tool or equipment that is found subsequently to be faulty) • research misconduct (data fabrication) • duplicate or overlapping publication • fraudulent use of data • clear plagiarism • unethical research for any retracted article, the reason for retraction and who is instigating the retraction will be clearly stated in the retraction notice. the retraction notice will be linked to the retracted article (which usually remains on the site) and the article will be clearly marked as retracted (including the pdf). an article is usually only retracted at the authors’ request or by the publisher in response to an institutional investigation. it is important to note in the context of mev's publication model, that ‐ as in traditional journals ‐ a retracted article is not ‘unpublished’ or ‘withdrawn’ in order for it to be published elsewhere. the reasons for retraction are usually so serious that the whole study, or large parts of it, are not appropriate for inclusion in the scientific literature anywhere. the content of a retracted article would only be removed where legal limitations have been placed upon the publisher, copyright holder or author(s), for example, if the article is clearly defamatory or infringes others’ legal rights, or if the article is the subject of a court order. in such cases, the bibliographic information for the article will be retained on the site along with information regarding the circumstances that led to the removal of the content. under rare circumstances, for example, if false or inaccurate data have been published that, if acted upon, pose a serious health risk, the original incorrect version(s) may be removed and a corrected version published. the reason for this partial removal would be clearly stated on the latest version. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xii preparing the manuscript formatting requirements please use the author submission template available online at mev journal website. to use the template, kindly ‘save as’ the ms word file to your document, then copy and paste your document. to copy and paste the text into the template, please use ‘special paste’ and choose ‘unformatted text’. papers not prepared in accordance with author guidelines and manuscripts with number of mistakes will have to be pre-rejected by editor. download the ‘author submission template’ docx http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx if your article includes any videos and/or other supplementary material, this should be included in your supplementary file at initial submission for peer review purposes. word processing software the manuscript should contain at least 2.000 words and should not exceed 25 pages including embedded figures and tables, contain no appendix, and the file should be in microsoft office (.doc/.docx) or open office (.odt) format. the paper should be prepared in a4 paper (210 mm x 297 mm) using 25 mm for left margin and 2 mm for the top, bottom, and right margin. no need to alter page number in this template as the page number will be reordered at preprinting process. the whole manuscript body should be in one column, using font type times new roman (tnr), font size 12, first line indent 5 mm, and 1.5 line spacing. please make sure that you use as much as possible normal fonts in your documents. special fonts, such as fonts used in the far east (japanese, chinese, korean, etc.) may cause problems during processing. to avoid unnecessary errors, you are strongly advised to use the ‘spellchecker’ function of ms word. section headings divide your article into clearly defined and numbered sections. the abstract is not included in section numbering. use this numbering also for internal cross-referencing: do not just refer to 'the text'. any subsection may be given a brief heading. each heading should appear on its own separate line. heading should be made in four levels. level five cannot be accepted. • heading level 1; heading 1 should be written in title case, left aligned, bold, 14 tnr, and roman numbered followed by a dot. • heading level 2; heading 2 should be written title case, left aligned, bold, 12 tnr, capital arabic numbered followed by a dot. • heading level 3; heading 3 should be written title case, left aligned, italic, 12 tnr, numbered by arabic number followed by closed bracket • heading level 4; heading 4 is not recommended, however, it could still be accepted with the format of sentence case, left indent 5 mm, hanging indent 5 mm, italic, 12 tnr, numbered by small cap followed by a closed bracket. • heading level 5; heading level 5 cannot be accepted in the manuscript. article structure the manuscript should begin with title, abstract, and keyword(s) followed by the main text. the main text should consist of at least imrad structure, except for the review article: introduction, method/material, result and discussion, and conclusion; followed by acknowledgement and references. introduction state the objectives of the work and provide an adequate background, state of the art, and should be avoiding a detailed literature survey or a summary of the results. explain how you addressed the problem and clearly state the aims of your study. material and methods provide sufficient details to allow the work to be reproduced by an independent researcher. methods that are already published should be summarized and indicated by a reference. if quoting directly from a previously published method, use quotation marks and also cite the source. any modifications to existing methods should also be described. a theory section (if necessarily added) should extend, not repeat, the background to the article already dealt with in the introduction and lays the foundation for further work. a calculation section represents a practical development from a theoretical basis. results and discussion results should be clear and concise. discussion should explore the significance of the results of the work, not repeat them. avoid extensive citations and discussion of published literature. the following components should be covered in the discussion section: how do your results relate to the original question or objectives outlined in the introduction section (what)? do you provide interpretation scientifically for each of your results or findings http://www.mev.lipi.go.id/mevfiles/mev_author_submission_template_17.1.docx journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiii presented (why)? are your results consistent with what other investigators have reported (what else)? or are there any differences? conclusions the main conclusions of the study may be presented in a short conclusions section, which may stand alone or form a subsection of a discussion or results and discussion section. the conclusion section should lead the reader to the important matter of the paper. suggestion or recommendation related to further research can also be added but not to confuse the research with an uncompleted work. acknowledgements collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. list here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). appendices it is not recommended to use appendices in mev journal submission. essential title page information title the title of the manuscript should be concise and informative, less than 15 words, title case, centered, bold. titles are often used in information-retrieval systems. the title should be accurate, unambiguous, specific, and completely identify the main issue of the paper. avoid abbreviations and formulae where possible. author names and affiliations author names should not contain academic title, official rank, or professional position. please clearly indicate the given name(s) and last/family name(s) -full name if possibleof each author and check that all names are accurately spelled. present the authors' affiliation addresses (where the actual work was done) below the names. write clear affiliation of all authors. affiliation includes name of department/unit, (faculty), the name of university/institution, complete postal address, and country. all contributing author should be shown in contribution order. corresponding author clearly indicate the corresponding author clearly for handling all stages of pre-publication, refereeing, and post-publication. this responsibility includes answering any future queries about methodology and materials. ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. present/permanent address if an author has moved since the work described in the article was done, or was visiting at the time, a 'present address' (or 'permanent address') may be indicated as a footnote to that author's name. the address at which the author actually did the work must be retained as the main, affiliation address. superscript arabic numerals are used for such footnotes. abstract and keywords abstract abstract should be concise and factual, contains neither pictures nor tables, and should not exceed 250 words. the abstract should state briefly the purpose of the research, reserch methods, the principal results, and major conclusions. an abstract is often presented separately from the article, so it must be able to stand alone. for this reason, references should be avoided, but if essential, then cite the author(s) and year(s). also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. graphical abstract a graphical abstract is optional. its use is encouraged as it draws more attention to the online article. the graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. graphical abstracts should be submitted as a supplementary file in the online submission system. image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. the image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. preferred file types: tiff, eps, pdf or ms office files. you can view example graphical abstracts on our information site. keywords the keywords should be avoiding general and plural terms and multiple concepts. be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. these keywords will be used for indexing purposes. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xiv instruments abbreviations, acronyms, and units define abbreviations and acronyms at the first time they are used in the text, even after they have been defined in the abstract. abbreviations such as ieee, si, mks, cgs, sc, dc, and rms do not have to be defined. do not use abbreviations in the title or heads unless they are unavoidable. use either si (mks) or cgs as primary units. (si units are encouraged.) english units may be used as secondary units (in parentheses). an exception would be the use of english units as identifiers in trade, such as “3.5-inch disk drive.”avoid combining si and cgs units, such as current in amperes and magnetic field in oersteds. this often leads to confusion because equations do not balance dimensionally. if you must use mixed units, clearly state the units for each quantity that you use in an equation. do not mix complete spellings and abbreviations of units: “wb/m2” or “webers per square meter,” not “webers/m2.” spell units when they appear in text: “...a few henries,” not “...a few h.” use a zero before decimal points: “0.25,” not “.25.” use “cm3,” not “cc”. math formulae mathematical equation should be clearly written, numbered orderly, and should be an editable text prepared using ms equation editor (not in image format) and should also be separated from the surrounding text. be sure that the symbols in your equation have been defined before or immediately following the equation. use “(1),” not “eq. (1)” or “equation (1),” except at the beginning of a sentence: “equation (1) is ...”. italicize roman symbols for quantities and variables, but not greek symbols. use a long dash rather than a hyphen for a minus sign. header-footer and hyperlink header and footer including page number must not be used. all hypertext links and section bookmarks will be removed from papers. if you need to refer to an internet email address or url in your paper, you must type out the address or url fully in regular font. footnotes footnotes should be avoided if possible. necessary footnotes should be denoted in the text by consecutive superscript letters. the footnotes should be typed at the foot of the page in which they are mentioned, and separated from the main text by a short line extending at the foot of the column. figure and table figure should be in grayscale, and if it made in color, it should be readable (if it later printed in grayscale). a caption should be sequentially numbered with arabic numerals and comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. the lettering on the artwork should be clearly readable and in a proportional measure and should have a finished, printed size of 8 pt for normal text and no smaller than 6 pt for subscript and superscript characters. use words rather than symbols or abbreviations when writing figure axis labels to avoid confusing the reader. as an example, write the quantity “magnetization,” or “magnetization, m,” not just “m.” if including units in the label, present them within parentheses. do not label axes only with units. in the example, write “magnetization (a/m)” or “magnetization (a ( m(1),” not just “a/m.” do not label axes with a ratio of quantities and units. for example, write “temperature (k),” not “temperature/k.” figures should have a brief description in the main body of the manuscript. insert figures and tables after they are cited in the text. for layouting purpose, please provide high resolution figure (≥300dpi) in .tif/.jpg/.jpeg. low-quality scans are not acceptable. figures and tables should be embedded and not supplied separately. moreover, kindly avoid mentioning the position of figure/table e.g. “figure below” or “table as follow” because the position will be rearranged in layouting process. do not put boxes around your figures to enclose them. we suggest that you use a text box to insert a graphic (which is ideally at least 300 dpi resolution tiff or eps file with all fonts embedded) because this method is somewhat more stable than directly inserting a picture. to have non-visible rules on your frame, use the msword “format” pull-down menu, select text box > colors and lines to choose no fill and no line. electronic artwork general points: • make sure you use uniform lettering and sizing of your original artwork. • preferred fonts: arial (or helvetica), times new roman (or times), symbol, courier. • number the illustrations according to their sequence in the text. • use a logical naming convention for your artwork files. formats regardless of the application used, when your electronic artwork is finalized, please 'save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): • eps (or pdf): vector drawings. embed the font or save the text as 'graphics'. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 xv • tiff (or jpg): color or grayscale photographs (halftones): always use a minimum of 300 dpi. • tiff (or jpg): bitmapped line drawings: use a minimum of 1000 dpi. • tiff (or jpg): combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required. please do not: • supply files that are optimized for screen use (e.g., gif, bmp, pict, wpg); the resolution is too low. • supply files that are too low in resolution. • submit graphics that are disproportionately large for the content. figure captions ensure that each illustration has a caption. a caption should comprise a brief title (not on the figure itself) and a description of the illustration. keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. figure caption of a single line must be centered whereas multi-line captions must be justified tables please submit tables as editable text and not as images. number tables consecutively with arabic numerals in accordance with their appearance in the text. place footnotes below the table body and indicate them with superscript lowercase letters. be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. please avoid using vertical rules and shading in table cells. construction of references references are recommended using ieee referencing style. please ensure that every reference cited in the text is also present in the reference list (and vice versa). references should be listed at the end of the paper and numbered in the order of their appearance in the text. the template will number citations consecutively within brackets [1]. the sentence punctuation follows the bracket [2]. refer simply to the reference number, as in [3]— do not use “ref. [3]” or “reference [3]” except at the beginning of a sentence: “reference [3] was the first ...” unpublished results and personal communications are not recommended in the reference list but may be mentioned in the text. if these references are included in the reference list, they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'unpublished results' or 'personal communication'. citation of a reference as 'in press' implies that the item has been accepted for publication. wikipedia, personal blog, or non-scientific website is not allowed to be taken into account. primary references should be at least 80% from at least fifteen references. references should be taken from the late ten years. avoid bulk references such as [1–9]. avoid excessive self-citations (no more than 20%). if possible, article’s doi should be given for each reference list. reference formatting there are two types of references, i.e., electronics sources and nonelectronics sources. sample of correct formats for various types of references are as follows • book: author, title. edition, editor, city, state or country: publisher, year, pages. • part of book: author, “title”, in book, edition, editor, city, state or country: publisher, year, pages. • periodical: author, “title”, journal, volume (issue), pages, month, year. • proceeding: author, “title”, in proceeding, year, pages. • unpublished paper: author, “title”, presented at conference/ event title, city, state or country, year. • paten/standart: author, “title”, patent number, month day, year. • technical report: author, “title”, company, city, state or country, tech. rep. number, month, year. three pieces of information are required to complete each reference from electronics sources: 1) protocol or service; 2) location where the item is to be found; and 3) item to be retrieved. sample of correct formats for electronics source references are as follows: • book: author. (year, month day). title. (edition) [type of medium]. volume (issue). available: site/path/file. • periodical: author. (year, month). title. journal. [type of medium]. volume (issue), pages. available: site/path/file. • papers presented at conferences: author. (year, month). title. presented at conference title. [type of medium]. available: site/path/file. • reports and handbooks: author. (year, month). title. company. city, state or country. [type of medium]. available: site/path/file. reference management software every article submitted to mev journal shall use reference management software that supports citation style language styles, such as mendeley and zotero, as well as endnote®. formatting requirements word processing software section headings article structure introduction material and methods results and discussion conclusions acknowledgements appendices essential title page information title author names and affiliations corresponding author present/permanent address abstract and keywords abstract graphical abstract keywords instruments abbreviations, acronyms, and units math formulae header-footer and hyperlink footnotes figure and table electronic artwork figure captions tables construction of references reference formatting reference management software the influence of two cylinder diesel engine modification(idi to di) on its performance and emission mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 accreditation number: 432/akred-lipi/p2mi-lipi/04/2012 www.mevjournal.com © 2013 rcepm lipi all rights reserved doi: 10.14203/j.mev.2013.v4.17-24 the influence of two cylinder diesel engine modification (idi to di) on its performance and emission yanuandri putrasari*, arifin nur, aam muharam research centre for electrical power and mechatronics, indonesian institute of sciences kompleks lipi gd. 20, jl. sangkuriang, bandung, indonesia received 18 march 2013; received in revised form 3 may 2013; accepted 3 may 2013 published online 30 july 2013 abstract modification of combustion system from indirect injection (idi) to direct injection (di) was carried out on the two cylinder diesel engine, followed with tests for performance and emission. the modification from idi to di was conducted on a two cylinder diesel engine by removing the pre-chamber from the inside of the cylinder head, replacing the injector and its position to the top of the combustion chamber directly and also replacing the original piston with a piston that has a bowl on the crown. performance and emission tests were conducted on 1,500 rpm with loads that vary from 0, 10, 20, 30, 40, 50, to 60 nm. the investigation results of the diesel engine modification from idi to di showed several interesting phenomena. further research is needed in order to increase the engine performance and reduce its emission. keywords: diesel, idi, di, performance, emission. i. introduction diesel engine has been widely used as power source in many devices or vehicles to help human life such as generator, ship, car, train, heavy duty vehicle, and etc [1, 2]. it has excellent superiority in high thermal efficiency, low fuel consumption, good endurance and durability compared to gasoline engine, gas turbine, steam turbine, and stirling engine [3-5]. diesel engine is an engine which is included in the internal combustion engine category and usually called as compression ignition engine. in the compression ignition engine, the properties of fuel and the injection system have a significant effect on engine performance and its emissions. combustion process on compression ignition engine is started when fresh air enters the combustion chamber. the diesel fuel is injected into the combustion chamber near the end of compression stroke, so the ignition occurred automatically due to the self ignition properties of diesel fuel and the increasing of the pressure and temperature resulted from air compressed in the chamber [6]. diesel engine is divided into two categories based on the combustion system i.e. indirect injection diesel engine (idi) and direct injection diesel engine (di) [7]. the first technology of compression ignition engine is indirect injection diesel engine (idi). idi system operates when the fresh air is compressed in combustion chamber while diesel fuel is injected in prechamber or swirl chamber near the end of compression stroke. the swirl effect of the air on pre chamber or swirl chamber, high pressure, and temperature are the main factor in this system [6]. disadvantage of indirect injection (idi) system is combustion takes longer duration due to the flame propagation on the shape of combustion chamber that causing the heat dissipated on combustion wall becomes higher. lower compression ratio and longer combustion process on idi system lead to lower thermal efficiency than di system [8, 9]. the advantage of idi system is it is more adaptive to low quality of fuel and low noise. nowadays fuel quality becomes better and legislation becomes stricter. research and development institutions and automobile manufacturers pay more focused on current technology i.e. direct injection diesel engine (di), turbo diesel intercooler (tdi) or homogeneous charge compression ignition (hcci). schematic diagram of the diesel combustion system for idi and di as discussed by huang [1] is depicted in figure 1. figure 1 (a) * corresponding author: tel: 022-2503055; fax: 022-2504773 e-mail: y.putrasari@gmail.com http://dx.doi.org/10.14203/j.mev.2013.v4.17-24 y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 18 shows schematic diagram for diesel engine with di combustion system. in the di system, diesel fuel is directly injected into combustion chamber near the end of compression stroke. the ignition is occurred at the local mixture on combustion chamber that generates the premix burning period then the flame propagates to the centre of combustion chamber (diffusion burning period) at the same chamber. so, in the di system, diesel fuel is injected directly into main chamber and the combustion is started and ended in the same chamber. figure 1 (b) shows the schematic diagram of idi combustion system of diesel engine. its working process is different from di system. the combustion process starts at local mixture on pre-chamber then the flame is propagated to the main chamber. modification of diesel engine was implemented because the existing engine is using idi system. another consideration is that in order to obtain better thermal efficiency and low fuel consumption, modification is cheaper than buying new diesel engine with di system to obtain better thermal efficiency and low fuel consumption. on the other hand, modification of idi diesel system into di system is needed to characterize the performance of di system as base data for the future development on hcci system. many literatures have discussed diesel engine of both di and idi combustion systems and the utilization of alternative fuel for the engine, as described by huang [1]. however many literatures described separately and rarely discussed performance and emission test result of a diesel engine modified from idi to di. therefore, this paper will describe the influence of modification of diesel engine 2 cylinder 1630 cc (idi to di) on the performance and its emissions. the information from this paper would be useful for researcher or academician who are interested or dedicate their research activity in the field of diesel engine. ii. investigation procedure investigation procedure in this study is divided into three sections as follow: a. engine testing installation the schematic diagram of engine testing installation is depicted in figure 2. the study was conducted by connecting the diesel engine with an eddy current dynamometer type schenk w70. the dynamometer was used to measure speed and load of the engine. the avl fuel balance, tgs hotwire anemometer, 4-gas analyzer, smoke meter, and temperature sensor were also installed on each position to measure fuel consumption, air intake velocity, gas emission, smoke index, and temperature of the engine, respectively. meanwhile, the crank angle sensor was attached on the crankshaft to determine the crank position. the pressure transducer type kistler 6061b as shown in figure 3 was installed in combustion chamber to measure the combustion pressure. the first tested diesel engines was fujikawa type 295d two cylinder idi made in china, and the second one was the first engine which modified to di with the same testing procedure. the diesel engine specification that used in this study is presented in table 1. figure 1. diesel engine combustion system (a) di and (b) idi [1] y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 19 b. modification process of diesel engine from idi to di the modification of diesel engine was conducted by closing the pre-chamber in the cylinder head using tin cast as shown in figure 4. after finished, it was then drilled with 25 mm diameter straight forward to the top of the cylinder to put cylinder iron bar (bushing) that had been prepared based on the injector that would be used. the bushing was used as adapter or buffer for the injector. the original injector was replaced using the other injector that usually used in diesel engine yanmar type tf 155r-di with the injection capacity and pressure that was slightly bigger and higher. the reason for using this injector is it was easy to look for and assumed that they have the same flow rate based on cylinder volume (815 cc/cylinder @ fujikawa 295d and 800 cc single cylinder @ yanmar 135r-di). the injector specification that was used in this study is presented in table 2. the screws and nuts of the old injector were replaced appropriately according to the new injector condition. to obtain an appropriate piston bowl for di diesel engine the piston of the diesel engine yanmar type tf 155 r-di was used with several modifications on its ring groove, piston pin hole, and reducing the length of the piston by reducing it for about 2 mm, as similar with previous study [10]. the weight of this piston was slightly heavier than the original part of the engine, so that it might have influenced the engine performances. the original piston shape of idi 1 2 3 4 8 12 6 13 10 5 9 7 11 14 15 legend: 1. air filter 10. crank angle sensor 2. air flow meter 11. amplifier 3. fuel balance 12. data acquisition system 4. fuel tank 13. monitor 5. motor diesel 14. temperature display 6. clutch 15. oil temperature sensor 7. dynamometer 16. emission meter display 8. dynamometer control 17. emission sensor 9. pressure sensor 16 17 figure 2. schematic diagram of engine testing installation figure 3. pressure transducer installation figure 4. cylinder head modification injector hole no. 2 injector hole no. 1 y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 20 system and yanmar tf 135r-di are shown in figure 5. meanwhile, the other parts such as piston pin and connecting rod used were still the genuine parts from the original engine. the last modification done after the engine was operated on di system was varying the injection timing by changing the position of injection pump until the appropriate condition was obtained. c. engine testing the engine testing conducted was referred to laboratory standard iso 17025 [11] emission testing standard iso 8178 [12] and diesel testing standard iso 3046 [13]. the engine was operated at 1,500 rpm using diesel fuel “solar“ as the brand for diesel fuel from the national enterprises pt. pertamina, tbk. with load variations of 0, 10, 20, 30, 40, 50, and 60 nm. the parameters from every condition of the operated engine were imep, fuel consumption, air intake air flow, oil temperature, air inlet and exhaust temperature, water temperature both inlet and outlet of radiator, smoke and co2 emission. the imep and fuel consumption data were recorded twice at each stage of testing processes. every measurement device and sensor was calibrated and has accuracy and uncertainty based on its specifications. the accuracy and calculated uncertainty of the measurement device in this study are presented in table 3. iii. results and discussion a. influence of modification of idi to di on the imep value the mean effective pressure is the appropriate parameter for engine comparison in terms of design and output, due to independency from size and/or engine speed [14], in this case this refers to indicated mean effective pressure (imep). the indicated power can be calculated from the indicated mean pressure [14]. figure 6 shows graph of imep comparison of diesel engine idi and di at 1,500 rpm. it can be seen that the imep value tended to increase due to the increasing engine load at 1,500 rpm engine speed, both for idi and di modified diesel engines. however, the testing result showed that imep value from idi diesel engine was higher than di modified diesel engine. the calculated indicated power would show that power of the diesel engine idi system was higher than that of the diesel engine modified to di system. this result was on contrary to the theory that has been discussed in several literatures [1, 8, 9, 15, 16]. this occurred due to the modification that was not successful table 1. engine specification data specification data type 4 stroke diesel engine number of valve 4 air intake system naturally aspirated number of cylinder/ type 2 / vertical volume (cc) 1,630 cc diameter x stroke 95 x 115 mm compression ratio 19 : 1 maximum torque 96.9 nm at 1,500 rpm maximum power 13.5 kw at 1,500 rpm fuel system 1. idi 2. then modified to di table 3. accuracy and calculated uncertainty of measurement measurement accuracy soot density +1 g/m3 co +5 % hc +20 ppm speed +5 rpm torque +0.2 nm calculation result uncertainty (%) fuel volume velocity +2 power +1 specific fuel consumption +1.5 efficiency +1.5 figure 5. the piston shape; (left) the existing idi engine; (right) yanmar tf 135r-di table 2. injector specification data specification original modification pressure 190 ± 5 bar 200 bar nozzle hole 1 4 injection volume/cycle 0.88 ml 1.01 ml y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 21 and that caused a power loss. the power loss could occur because of the absence of combustion (misfire), injection timing, incorrect shape of combustion chamber, and lower compression ratio. b. influence of modification of idi to di on the bsfc and lambda value figure 7 shows the comparison of brake specific fuel consumption (bsfc). from the figure it can be seen that the bsfc value tended to decrease with the increasing load value of both diesel engines idi and di. like the imep, the bsfc value of idi diesel engines was greater than di modified engines. this indicated failure modification. bsfc values of di diesel engine in general are bigger than the idi diesel engine’s which also indicates a failure modification in term of performance. normally, the idi engine should be higher in fuel consumption than the di engine due to double combustion processes i.e. which are firstly, combustion occurs for a half of fuel in pre-chamber then secondly, continue in main chamber which needs a longer time than di engine to finish a combustion process [9]. the lambda values were calculated and presented as a graph in figure 8 to clarify economic property in term of diesel engine fuel consumption. in this study, the lambda value was resulted from the calculation based on fuel consumption and air intake measurement. referring to the literature [17] increasing lambda value shows lean combustion and decreasing lambda value show rich combustion. in the diesel engine, the best lambda value is about 1.2 until 1.6 and the lambda value for idi engine is lower than di engine [7]. the results of this study were not in accordance with the existing data in the literature [7]. the reason for this condition might have been the idi injector has been replaced with higher capacity injector. besides, the piston replacement with several modifications was able to cause the air intake of di became engine lower than idi engine’s. c. influence of modification of idi to di on the smoke index (bosch index) emission formation on diesel engine depends on fuel properties (cetane number, flash point, and etc), combustion system, load and injection timing. figure 9 shows the comparison of smoke emission from idi diesel engine and modified diesel engine di. the graphs show that the percentage of smoke emission on di diesel engine was significantly greater than idi diesel engine system. the lower smoke value on idi diesel engine happened due to the correct injection operation (volume) and two steps of combustion process. the first step is called premix burning period. the premix burning figure 6. imep comparison of diesel engine idi and di at 1,500 rpm figure 8. lambda comparison of diesel engine idi and di at 1,500 rpm figure 7. bsfc comparison of diesel engine idi and di at 1,500 rpm y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 22 period began when the slightly rich fuel mixture in the pre-chamber ignited due to the increasing of pressure and temperature of compression stroke. the combustion process in pre chamber led to the flame propagation from pre chamber to the main chamber. the pressure and temperature in main chamber would increase due to the flame propagation. the swirl effect occurred due to the flame propagation, pressure, and design of pre chamber. the second step was the diffusion burning period or the combustion in main chamber. since the swirl passage was far from the main chamber, the flame propagation would slightly be restricted and would cause a stratified combustion. the stratified combustion means longer combustion duration. longer duration of combustion process provides more time to the air and fuel in main chamber to form a good flammability mixture. the proper air fuel mixture will generate a complete combustion in combustion chamber, and will produce lower smoke percentage. meanwhile, in the modified di system, fuel was directly injected to the main chamber at the end of compression stroke. ignition occurred in the local mixture in combustion chamber which had stoichiometric air-fuel ratio, then propagated to the rich region mixture. the air and fuel in combustion chamber only had a little time to form a proper mixture. when the local stoichiometric mixture was igniting, the flame propagation occurred and burnt all of the mixture in combustion chamber spontaneously. the advantage of spontaneous combustion is higher pressure in combustion chamber to push the piston. the disadvantage of this system is the short preparation time to mix the air and fuel properly. in di diesel system, the shape of combustion chamber is the main parameter to optimize the performance of diesel engine. the incorrect shape of combustion chamber will generate the poor performance and high emission. therefore, the smoke emission of idi diesel system in this experiment was lower than di modified system. it was in accordance with what that has been discussed by huang [1]. d. influence of modification of idi to di on co emissions incomplete combustion on diesel engine happens when fuel cannot mix completely with air on combustion chamber. in diesel engines, the correct operation of injectors and injector pump is essential for correct combustion. if too much fuel is supplied or a dribbling injector supplies fuel after most of the air has been used, excessive heat that generated by burning of the fuel mixture will lead the deformation of co and smoke [16, 18]. figure 10 shows the comparison of co emission from diesel engine idi and di. from the figure, it can be seen that co emission from diesel engine with idi system was reduced with the increasing engine load. the co emission increased with the increasing engine load for diesel engine with di system. overall, the co emission of diesel engine with idi system was significantly lower than that of diesel engine modified di system. co is the medium product of hydrocarbon based fuel, so that the co emission is resulted from incomplete combustion [19]. it has been reported before [1] that combustion from idi system can be more completed than combustion in di system related to the design of combustion system. the co emission from idi was lower than di, due to the different injection sac volume from modified injector, more nozzle hole (4 holes) and incorrect spray pattern of the injector to the piston bowl. thus, the fuel was over supplied to the chamber. meanwhile, the modified piston probably had inappropriate piston bowl. the injector also figure 10. co emission comparison of diesel engine idi and di at 1,500 rpm figure 9. smoke comparison of diesel engine idi and di at 1,500 rpm y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 23 probably was not in good position and the ring piston probably had a bigger gap. thus, the combustion was uncompleted and the co emission of modified diesel engine di was higher than diesel engine idi systems. iv. conclusion modification of 2 cylinder 1630 cc diesel engine from idi to di system has been conducted. the engine was successfully operated in di system. from overall investigation it was indicated that the modification of 2 cylinder 1630 cc diesel engine from idi to di system was unsuccessful both of performance and its emission. the unsuccessful modification happened due to the incorrect injector flow rate, lower compression ratio, injector position to the piston bowl, and injection timing. the di injector had higher flow rate than the original injector (approximately 12.87% higher). the bigger piston bowl from yanmar tf135r-di generated lower compression ratio in di engine. this condition caused the idi engine to have 19:1 compression ratio and di modified system to have 17:1 compression ratio. the incorrect injector position and injection timing produced more stratified mixture in combustion chamber. stratification of air-fuel mixture in di combustion chamber system is an undesired condition because it will generate local mixture that has stoichiometric air-fuel ratio which will ignite earlier. by adjusting the injection timing, reshaping the combustion chamber, increasing compression ratio, and increasing injection pressure the performance and emission of di diesel engine is expected to be better. acknowledgement this project is financially supported by indonesian institute of sciences research centre for electrical power and mechatronics through the kompetitif lipi 2011 research project. the assistance of mr. ahmad dimyani and mr. mulia pratama in conducting the experiments in internal combustion engine laboratory is also highly appreciated. references [1] j. huang, et al., "experimental study of the performance and emission characteristics of diesel engine using direct and indirect injection systems and different fuels," fuel processing technology, vol. 92, pp. 1380-1386, 2011. [2] m. gomaa, et al., "trade-off between nox, soot and egr rates for an idi diesel engine fuelled with jb5," world academy of science, engineering and technology, vol. 38, p. 6, 2010. [3] a. nur, "pengaruh pergeseran waktu injeksi terhadap performa dan opasitas motor diesel," presented at the semnas teknik mesin 3, 2008. [4] w.-j. lee, et al., "assessment of energy performance and air pollutant emissions in a diesel engine generator fueled with water-containing ethanol–biodiesel– diesel blend of fuels," energy, vol. 36, pp. 5591-5599, 2011. [5] l. xing-cai, et al., "effect of cetane number improver on heat release rate and emissions of high speed diesel engine fueled with ethanol–diesel blend fuel," fuel, vol. 83, pp. 2013-2020, 2004. [6] h. permana, "beberapa pengetahuan dasar mengenai mesin diesel," buletin itp, vol. ii, pp. 25-29, 1996. [7] f. j. wallacae, "the theory of compression ignition engine," in diesel engine reference book, b. challen and r. baranescu, eds., 2nd ed oxford: butterworth-heinemann, 1999, pp. 3-26. [8] c. d. rakopoulos, et al., "study of combustion in a divided chamber turbocharged diesel engine by experimental heat release analysis in its chambers," applied thermal engineering, vol. 26, pp. 1611-1620, 2006. [9] k. b. binder, "diesel engine combustion," in handbook of diesel engine, k. mollenhauer and h. tschoeke, eds., 1st ed heidelberg: springer verlag, 2010, pp. 61-75. [10] a. nur, et al., "the effect of ethanoldiesel blends on the performance of a direct injection diesel engine," mechatronics, electrical power, and vehicular technology vol. 03, pp. 49-56, 2012. [11] iso, "reciprocating internal combustion engine-performance," vol. 3046-3, ed: iso, 2006. [12] iso, "general competence of testing and calibration," vol. 17025, ed: iso, 2005. [13] iso, "reciprocating internal combustion engines-exhaust emission measurement," vol. 8178-1, ed: iso, 2006. y. putrasari et al./ mechatronics, electrical power, and vehicular technology 04 (2013) 17-24 24 [14] w. w. pulkrabek, engineering fundamentals of the internal combustion engine. new jersey: prentice hall, 1997. [15] j. b. heywood, internal combustion engine fundamentals; chapter 10: combustion in compression-ignition engines. new york: mcgraw-hill, 1988. [16] j. v. gerpen, "diesel combustion and fuels," in diesel engine reference book, b. challen and r. baranescu, eds., 2nd ed oxford: butterworth-heinemann, 1999, pp. 90-104. [17] j. b. heywood, internal combustion engine fundamentals; chapter 3: thermochemistry of fuel-air mixtures. new york: mcgraw-hill, 1988. [18] acl engine manual no. 413, 1st ed. waterloo: gregory's scientific publications, 1991. [19] r. c. engineer, "exhaust emissions,” in diesel engine reference book," in diesel engine reference book, b. c. a. r. baranescu, ed., ed oxford: butterworthheinemann, 1999, pp. 473-483. introduction investigation procedure engine testing installation modification process of diesel engine from idi to di engine testing results and discussion influence of modification of idi to di on the imep value influence of modification of idi to di on the bsfc and lambda value influence of modification of idi to di on the smoke index (bosch index) influence of modification of idi to di on co emissions conclusion mev front cover journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 aim and scope journal of mechatronics, electrical power, and vehicular technology (mev) is an internationally peer-reviewed journal aims to provide authoritative global source of scientific information for researchers and engineers in academia, research institutions, government agencies, and industries. the journal publishes original research papers, review articles and case studies focused on: mechatronics: including control system, robotic, cnc machine, sensor, signal processing, electronics, actuator, and mechanical dynamics. electrical power: including power generation, transmission system, new and renewable energy, turbine and generator design and analysis, grid system, and source assessment. vehicular technology: including electric/hybrid vehicle design and analysis, vehicle on grid, fuel efficiency, and safety analysis. mev's vision is to become an international platform with high scientific contribution for the global community. mev's mission is presenting important results of work, whether in the form of research, development, application, or design. imprint mev is published by national research and innovation agency (brin) formerly indonesian institutes of sciences (lipi). issn print: 2087-3379 issn electronics: 2088-6985 electronics edition is available at: https://mev.lipi.go.id all published article are embedded with doi number affiliated with crossref doi prefix 10.14203 publication frequency mev is managed to be issued twice in every year. the first issue should be in the mid of the year (july) and the second issue is at the end of the year (december). peer review policy mev reviewing policies are: every submitted paper will be reviewed by at least two peerreviewers. reviewers are unaware of the identity of the authors, and authors are also unaware of the identity of reviewers (double blind review method). reviewing process will consider novelty, objectivity, method, scientific impact, conclusion, and references. accreditation mev is sinta 1 accredited by kementerian pendidikan, kebudayaan, riset, dan teknologi republik indonesia via national journal accreditation (arjuna) accreditation platform. https://sinta.kemdikbud.go.id/j ournals/profile/814 postal address mev journal secretariat: research center for smart mechatronics, national research and innovation agency (brin) kst samaun samadikun brin jl. sangkuriang, dago, kec. coblong, bandung, west java, 40135 indonesia business hour: monday to friday 08:00 to 16:00 gmt+7 e-mail: jmev@brin.go.id ; sekretariat@mevjournal.com https://mev.lipi.go.id/ https://sinta.kemdikbud.go.id/journals/profile/814 https://sinta.kemdikbud.go.id/journals/profile/814 mailto:jmev@brin.go.id mailto:sekretariat@mevjournal.com journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 online submissions if you already have a username/password for journal of mechatronics, electrical power, and vehicular technology? go to login at: https://mev.lipi.go.id/mev/login need a username/password? go to registration at: https://mev.lipi.go.id/mev/user/r egister registration and login are required to submit items online and to check the status of current submissions. copy editing and proofreading every article accepted by mev journal shall be an object to grammarly® writingenhancement program conducted by mev journal editorial board. reference management every article submitted to mev journal shall use reference management software e.g. endnote® or mendeley. open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. processing charges every article submitted to mev journal will not have any article processing charges. this includes submission, peer-reviewing, editing, publishing, maintaining and archiving, and allows immediate access to the full text versions of the articles. plagiarism check plagiarism screening will be conducted by mev editorial board using crossref similarity checktm powered by ithenticate®. crossmark every article will be published along with crossmark button in the pdf and in the online abstract page. crossmark gives readers quick and easy access to the current status of a piece of content. cited-by published article will be equipped with crossref cited-by service. cited-by lets publishers show authors and readers what other crossref content is citing their content. indexing & abstracting mev has been covered by these following indexing services: ebscohost, google scholar, directory of open access journal (doaj), science and technology index (sinta), crossref, indonesian scientific journal database (isjd), indonesian publication index (ipi), citeulike, cite factor, academic journal database, researchbib, bielefeld academic search engine (base), worldcat, sherpa romeo, index copernicus, open academic journal index (oaji), open access articles, road: the directory of open access scholarly resources, toronto public library, western theological seminary, ghent university library, and electronic journals library. currently, mev has been completed csab review and accepted for scopus inclusion cc license mev journal by national research and innovation agency (brin) allows reuse and remixing of its content under a cc by-ncsa creative commons attribution-noncommercialsharealike 4.0 international license. permissions beyond the scope of this license may be available at https://mev.lipi.go.id. if you are a nonprofit or charitable organization, your use of an nclicensed work could still run afoul of the nc restriction, and if you are a for-profit entity, your use of an nclicensed work does not necessarily mean you have violated the term. https://mev.lipi.go.id/mev/login https://mev.lipi.go.id/mev/user/register https://mev.lipi.go.id/mev/user/register http://www.brin.go.id/ http://www.brin.go.id/ http://www.brin.go.id/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ http://creativecommons.org/licenses/by-nc-sa/4.0/ https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 editor-in-chief dr. haznan abimanyu, dip.ing. research organization for energy and manufacture brin indonesia associate editor (main handling editor) yanuandri putrasari, ph.d. research center for smart mechatronics – brin indonesia international editorial board prof. rosli bin abu bakar faculty of mechanical engineering, universiti malaysia pahang, malaysia prof. dr. estiko rijanto research center for smart mechatronics – brin, indonesia prof. tapan kumar saha electrical engineering, the university of queensland, australia prof. muhammad nizam, s.t., m.t., ph.d. department of mechanical engineering, universitas sebelas maret surakarta, indonesia prof. josep m rossell control, dynamics and applications (codalab), department of mathematics universitat politècnica de catalunya (upc), spain prof. dr. tagawa yasutaka tokyo university of agriculture and technology, japan prof. tatacipta dirgantara mechanical and aerospace engineering, bandung institute of technology, indonesia prof. dr. bambang riyanto trilaksono school of electrical engineering and informatics, bandung institute of technology, indonesia prof. keum shik hong dept. of mechanical engineering, pusan national university, korea, republic of prof. taufik director of electric power institute, california polytechnique, united states prof. dr. adi soeprijanto dept. of electrical engineering, institut teknologi sepuluh nopember (its), indonesia assoc. prof. hazim moria department of mechanical engineering, yanbu industrial college, saudi arabia assoc. prof. john young school of engineering and it, the university of new south wales, australian defence force academy, australia assoc. prof. roonak daghigh university of kurdistandisabled, sanandaj, iran, islamic republic of asst. prof. mohammad h. yazdi mechanical eng. dept., islamic azad university, iran, islamic republic of dr. jose guivant school of mechanical and manufacturing engineering, the university of new south wales, australia dr. ahmad fudholi solar energy research institute, universiti kebangsaan malaysia, malaysia dr. ali h.a. al-waeli solar energy research institute, universiti kebangsaan malaysia, malaysia george anwar, ph.d. university of california, united states dr. agus sunjarianto pamitran dept. of mechanical engineering, university of indonesia, indonesia riza muhida, ph.d. information system, bandar lampung university, indonesia dr.eng. budi prawara research organization for electronics and informatics – brin, indonesia advisory editor prof. ocktaeck lim school of mechanical engineering, university of ulsan, korea, republic of prof. dr. endra joelianto engineering physics, bandung institute of technology, indonesia javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/741') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/743') javascript:openrtwindow('http://www.mevjournal.com/index.php/mev/about/editorialteambio/745') journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 © 2022 national research and innovation agency. some rights reserved. this journal and the individual contributions contained in it are protected under copyright by national research and innovation agency. and the following terms and conditions apply to their use: open access policy mev journal provides immediate open access to its content on the principle that making research freely available to the public to supports a greater global exchange of knowledge. copyright notice authors who publish with this journal agree to the following terms: • authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a creative commons attribution license that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. • authors are able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. • authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after the acceptance and during the editing process, as it can lead to productive exchanges, as well as earlier and greater citation of published work privacy statement the names and email addresses entered in this journal site will be used exclusively for the stated purposes of this journal and will not be made available for any other purpose or to any other party. notice no responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 i journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 foreword from editor-in-chief welcome to the latest issue in 2022 of the journal of mechatronics, electrical power, and vehicular technology (mev), a peer-reviewed and broad-scope international journal. this issue consists of ten papers written by authors from different countries, such as australia, china, india, indonesia, japan, malaysia, philippines, taiwan, united kingdom, and vietnam. we are pleased in this issue to present a diverse range of articles and papers that cover a wide range of topics within the field of mechatronics, electrical power, and vehicular technology. one of the standout contributions in this issue is a paper by rupesh and tegampure on the dnn control technique in the photovoltaic system. this research has the potential to significantly impact the way we approach treatment in this area, and we are thrilled to have the opportunity to share this work with our readers. we are also pleased to feature an article by ramadiansyah et al. on the numerical investigation of the effect of ocean depth variations on the manipulator joint torque. this work provides development a mathematical model of a ship mounted two-dof manipulator considering the ship dynamics and characterization of the ship motions. in addition to these articles, we have several other papers that cover a wide range of topics, including an overview of early termination of pv-dg microgrid system, a method to find pump performance specifications when using a pump with a mixed flow type as a turbine for micro hydro power plants, investigation the impact of lightning masts placement on underground cables within high voltage substations, examination the strength of the universal joint after it was loaded with torsion, long-term forecasting for growth of electricity load based on customer sectors, optimization take-off position control of the bicopter model by investigating lqr cost matrices variation in actual experiments, plumbing leakage detection system with water level detector controlled by programmable logic controller, and a novel solution to deal with the complicated electronic circuitry for speed controller and too complex mechanical design of rotating mechanism of an orbital shaker. we hope that you will find this issue to be a valuable resource, and we look forward to continuing to bring you the latest research and insights in the field of mechatronics, electrical power, and vehicular technology. bandung, december 2022 editor-in-chief journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 ii list of contents experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs) jalu ahmad prakosa, hai wang, edi kurniawan, swivano agmal, muhammad jauhar kholili ................................................................................................................................................... 101-112 numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system mohamad luthfi ramadiansyah, edwar yazid, cheng yee ng ............................................. 113-124 numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application sarid mejiartono, muhammad fathul hikmawan, aditya sukma nugraha ..................... 125-136 plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a sri hartanto, desmayadi ................................................................................................................. 137-146 design, construction, and evaluation of transformer-based orbital shaker for coffee micropropagation edwin romeroso arboleda ............................................................................................................. 147-156 cascade feedforward neural network and deep neural network controller on photovoltaic system with cascaded multilevel inverters: comparison on standalone and grid integrated system mailugundla rupesh, vishwanath shivalingappa tegampure ............................................. 157-178 torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials hartono yudo, andi setiawan, ocid mursid, muhammad iqbal .......................................... 179-188 effect of lightning mast placement on underground power cable jacket stress within high voltage substations mostafa nazih..................................................................................................................................... 189-200 journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 iii component degradation and system deterioration: an overview of early termination of pv-dg microgrid system tinton dwi atmaja, dalila mat said, sevia mahdaliza idrus, ahmad fudholi, nasarudin ahmad, dian andriani, ahmad rajani, sohrab mirsaeidi, haznan abimanyu ................. 201-213 long-term forecasting for growth of electricity load based on customer sectors sujito, ridho riski hadi, langlang gumilar, abdullah iskandar syah, moh. zainul falah, tran huy duy ...................................................................................................................................... 214-221 complete articles can be found at https://mev.lipi.go.id https://mev.lipi.go.id/ journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 journal of mechatronics, electrical power, and vehicular technology volume 13, issue 2, 2022 iv abstracts sheet e-issn: 2088-6985 p-issn: 2087-3379 the descriptions given are free terms. this abstract sheet may be reproduced without permission or change. jalu ahmad prakosa a, hai wang b, edi kurniawan a, swivano agmal c, muhammad jauhar kholili c (a research center for photonics, national research and innovation agency (brin), indonesia; b discipline of engineering and energy, murdoch university, australia; c research center for quantum physics, national research and innovation agency (brin), indonesia) experimental studies of linear quadratic regulator (lqr) cost matrices weighting to control an accurate take-off position of bicopter unmanned aerial vehicles (uavs) journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 101-112, 17 ill, 5 tab, 27 ref. controller design for airplane flight control is challenged to achieve an optimum result, particularly for safety purposes. the experiment evaluated the linear quadratic regulator (lqr) method to research the optimal gain of proportionalintegral-derivative (pid) to hover accurately the bicopter model by minimizing error. the 3 degree of freedom (dof) helicopter facility is a suitable bicopter experimental simulator to test its complex multiple input multiple output (mimo) flight control model to respond to the challenge of multipurpose drone control strategies. the art of lqr setting is how to search for appropriate cost matrices scaling to optimize results. this study aims to accurately optimize take-off position control of the bicopter model by investigating lqr cost matrices variation in actual experiments. from the experimental results of weighted matrix variation on the bicopter simulator, the proposed lqr method has been successfully applied to achieve asymptotic stability of roll angle, although it yielded a significant overshoot. moreover, the overshoot errors had good linearity to weighting variation. despite that, the implementation of cost matrices is limited in the real bicopter experiment, and there are appropriate values for achieving an optimal accuracy. moreover, the unstable step response of the controlled angle occurred because of excessive weighting. (author) keywords: experimental evaluation; cost matrices; lqr; bicopter; mimo flight control. mohamad luthfi ramadiansyah a, edwar yazid a, cheng yee ng b (a research center for smart mechatronics, national research and innovation agency (brin), indonesia; b department of civil and environmental engineering, universiti teknologi petronas, malaysia) numerical investigation of the effect of ocean depth variations on the dynamics of a ship mounted two-dof manipulator system journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 113-124, 10 ill, 7 tab, 32 ref. the dynamics of a ship need to be considered in the development of a manipulator system that will be applied to the ocean-based operation. this paper aims to investigate the effect of ocean depth variations on the ship motion as disturbances to a ship-mounted two-dof (degrees of freedom) manipulator joint torque using an inverse dynamics model. realization is conducted by deriving the mathematical model of a two-dof manipulator system subject to six-dof ship motion, which is derived by using lagrange-euler method. it is then combined with numerical hydrodynamic simulation to obtain the ship motions under ocean depth variations, such as shallow (50 m), intermediate (750 m), and deep (3,000 m) waters. finding results show that randomness of the ship motions appears on the manipulator joint torque. in the azimuth link, maximum joint torque is found in shallow water depth with an increment of 8.271 n.m (285.69 %) from the undisturbed manipulator. meanwhile, the maximum joint torque of the elevation link is found in intermediate water depth with an increment of 53.321 n.m (6.63 %). however, the difference between depth variations is relatively small. this result can be used as a baseline for sizing the electrical motor and developing the robust control system for the manipulator that is mounted on the ship by considering all ocean depth conditions. (author) keywords: two-dof manipulator; inverse dynamics; ship motion; ocean depth; hydrodynamic response. sarid mejiartono a, muhammad fathul hikmawan b, aditya sukma nugraha b, c (a faculty of mechanical and aerospace engineering, bandung institute of technology, indonesia; b research center for smart mechatronics, national research journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 v and innovation agency (brin), indonesia; c department of mechanical engineering, national taiwan university of science and technology, taiwan) numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 125-136 15 ill, 11 tab, 26 ref. the use of a pump as opposed to a turbine/pump as turbine (pat) for off-grid electrification applications is one of the important ways to be considered in efforts to equalize electrical energy in indonesia. the main problem in pat applications is how to predict pump performance if applied as a turbine to find out its best characteristics and efficiency points. this study discusses a method to find pump performance specifications when using a pump with a mixed flow type as a turbine for micro hydro power plants. the numerical method by utilizing computational fluid dynamics (cfd) based software simulations that have been proven to be accurate according to previous studies was selected for use in obtaining predictions of the pump characteristics as turbines. then the pat characteristics of the cfd simulation results are validated by conducting direct testing. the results of the cfd numerical simulation using ansys fluent software show the performance curve of a mixed flow pump operated as a turbine at various rotating speeds. the highest efficiency for each rotating speed ranges from 35-40 %. the test results directly show the pat characteristics, that the performance range is close to the numerical simulation results with a difference of 10 %. (author) keywords: pump as turbine (pat); micro hydro power plant; computational fluid dynamics (cfd). sri hartanto a, desmayadi b (a teknik elektro, universitas krisnadwipayana, indonesia; b nissinbou industries, inc, japan) plumbing leakage detection system with water level detector controlled by programmable logic controller type omron cpm2a journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 137-146, 10 ill, 5 tab, 26 ref. there is a chance of leakage in the plumbing caused by water pressure in the pipes, improper installation of pipe connections, or external influences, such as earthquakes. plumbing leakage that is detected too late can cause damage to other systems. it is necessary to have a plumbing leakage detection system to detect a leak in the plumbing. therefore, in this research, a plumbing leakage detection system is designed with a water level detector (wld) controlled by a programmable logic controller (plc) type omron cpm2a. the method used in this research is designing the optimal model form of the system, which is distinguished by designing hardware and software, testing the devices, such as power supply, wld, and channel relay module (crm), and making conclusions. from the results of this research, it was found that the system works well in detecting leakage of plumbing, as indicated by all transistors' ability to work well where the electrodes (e1 and e2) are connected by water. the transistor in the wld module will work as a switch or transistor in the saturation position. in this research, it can be seen that even though there is a leakage from the relay contacts of 1.8 vdc, it is still considered in a safe condition because to provide a trigger to the 3b3d module, a minimum of 12 vdc is required. in addition, when the relay is not working or off, the measurement at the normally closed (nc) terminal is 12 vdc. (author) keywords: channel relay module (crm); leakage detection; programmable logic controller (plc); water level detector (wld). edwin romeroso arboleda (department of computer and electronics engineering, cavite state university, philippines) design, construction, and evaluation of transformer-based orbital shaker for coffee micropropagation journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 147-156, 23 ill, 2 tab, 25 ref. this study offers a novel solution to deal with the complicated electronic circuitry for speed controller and too complex mechanical design of rotating mechanism of an orbital shaker. the developed prototype used a transformer that varies the supply voltage to control the speed of rotation of the orbital shaker. the prototype has five speed levels which depend on the input voltage. these speeds are 180 rpm at 12 v, 258 rpm at 15 v, 360 rpm at 18 v, 427 rpm at 21 v, and 470 rpm at 24 v. the prototype was tested to run continuously for 48 hours for each speed level, with speed being measured every hour using a tachometer. statistical computation shows that the speed remains constant for the entire 48 hour period. evaluation of results shows that the speed controller and the novel mechanical design for the orbital shaking motion achieved their functions. for this reason, it can be concluded that the prototype is durable and safe for use in orbital shaking applications. (author) keywords: dc motor; orbital shaker; rotating mechanism; speed controller; step-down transformer. mailugundla rupesh a, vishwanath shivalingappa tegampure b (a department of electrical & electronics engineering, india; b department of electronics & communication engineering, india) cascade feedforward neural network and deep neural network controller on photovoltaic system with cascaded multilevel inverters: comparison on standalone and grid integrated system journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 157-178, 31 ill, 2 tab, 21 ref. the introduction of a micro-grid-based power generation network will help to meet the demands of consumers while reducing environmental impact. several industrialized and emerging countries allocate considerable resources to renewable energy-based power generation and invest significant sums of money in this area. this study examines the challenges involved with electricity generation through photovoltaic (pv) systems and the integration of the same with the grid to mitigate power quality issues and improve the power factor for various loading conditions. an innovative multilayer inverter for grid-connected pv systems has been developed to enhance the voltage profile and resulted in a drop in total harmonic distortion (thd). a cascade multilevel inverter (associated with a gridintegrated pv system and managed using multiple innovative artificial intelligence controllers) was developed in this research project. various advanced intelligent controllers, such as cascade feedforward neural networks journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 www.mevjournal.com p-issn 2087-3379 vi (cffnn) and deep neural networks (dnn), have been analyzed under various operating situations and observed that the thd of voltage, current at the grid, and the load is less than 3 % as per the ieee 519 standards along with this power factor is maintained nearly unity for the gridconnected system. the quality of power in terms of voltage, frequency, total harmonics distortion, and power factor are improved by using a novel deep neural network algorithm in a cascaded multilevel inverter and verified according to ieee 1547 and ieee 519 standards to determine the efficacy of the proposed system. (author) keywords: cascaded feedforward neural network; deep neural network; multilevel inverter; photovoltaic system; total harmonics distortion. hartono yudo a, andi setiawan a, ocid mursid a, muhammad iqbal b (a department of naval architecture, faculty of engineering, diponegoro university, indonesia; b department of naval architecture, ocean, and marine engineering, university of strathclyde, united kingdom) torsional strength analysis of universal joint’s zp-11a due to yokes modification and materials journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 179-188, 15 ill, 8 tab, 20 ref. the study examined the strength of the universal joint after it was loaded with torsion. it used different materials that can withstand tensile stress in accordance with accepted principles and made modifications to the yoke as a result of the topology optimization process. the topology optimization determined that the yoke's part needed to withstand load without changing its dimensions and minimize stress distribution. according to the results, the maximum shear stress on the spider of the original universal joint model made of jis-sf590a steel was 84.57 mpa, the shear stress on the yoke component was 30.84 mpa, and the maximum von mises was 341.1 mpa. as a result of using jis-sf590a steel, yoke modification 3 has produced a reduction in shear stress of 12.97 % and a reduction in von mises stress of 35.33 % from the original yoke. this is the most efficient design of yoke and also this modified yoke form provides a wider elevation angle and is easier to manufacture. (author) keywords: shear stress; topology optimization; universal joint; von mises. mostafa nazih (future energy, ghd pty ltd, australia) effect of lightning mast placement on underground power cable jacket stress within high voltage substations journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 189-200, 17 ill, 1 tab, 30 ref. this study aims to investigate the impact of lightning masts placement on underground cables within high voltage substations. while the subject of lightning discharges near to underground cables has been covered with open cable runs and wind farms in many papers, this study focuses on lightning events within high voltage substations considering the associated effective zones, which were not covered in the available literature. substations built within areas prone to high lightning activity experience frequent discharges that cause the potential rise of the earthing system into hundreds of kilovolts. the potentials propagating within the soil and the earthing grid affect underground cables jackets terminated within the substation. the numerical analysis of the problem is carried out using current distribution, electromagnetic fields, grounding and soil structure analysis (cdegs) software engine for different configurations of lightning mast placements with varied separation, electrode placement and length, soil resistivity, and lightning current. study findings indicate that provision of lightning masts/down conductors as far as possible or at least twice the effective zone radius from cable termination/route electrodes ensures relatively lower stress voltages. electrodes with effective zone radius length placed as close as possible to lightning masts further reduce the attainable jacket stress voltages. (author) keywords: substation earthing; lightning mast placement; high voltage; underground cable; effective zone radius. tinton dwi atmaja a, b, c, dalila mat said a, c, sevia mahdaliza idrus a, c, ahmad fudholi b, d, nasarudin ahmad a, dian andriani e, f, ahmad rajani a, b, c, sohrab mirsaeidi g, haznan abimanyu h, (a faculty of electrical engineering, universiti teknologi malaysia, malaysia; b research centre for energy conversion and conservation, national research and innovation agency, indonesia, c centre of electrical energy system, institute of future energy, utm, malaysia; d solar energy research institute, universiti kebangsaan malaysia, malaysia; e faculty of civil engineering, universiti teknologi malaysia, malaysia; f research organization for life sciences & environment, national research and innovation agency, indonesia; g school of electrical engineering, beijing jiaotong university, china; h research organization for energy and manufacture, national research and innovation agency, indonesia) component degradation and system deterioration: an overview of early termination of pv-dg microgrid system journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 201-213, 9 ill, 3 tab, 100 ref. degradation of components and system failure within the microgrid system is deteriorating the performance of electrification. the aim of this study is to discuss the relationship and connections between issues resulting from degradation and deterioration in the microgrid system, in addition to introducing the prominent impacts which may eventually lead to the premature termination of the microgrid system. this study explored the microgrid degradation and deterioration issues within four microgrid sections: generation section, storage section, transmission section, and distribution section. subsequently, this study analyzes, derives, and classifies all emerging issues into four types of prominent impacts. the degradation and deterioration invoked many component performance issues into four main damaging outcomes, namely (i) deteriorated transmission line yielded issues regarding expected energy not achieved; (ii) energy deficit and unpredicted blackout come after the depth of discharge (dod) reduction and invoke a loss of power supply; (iii) a shorter battery life cycle, shorter transformer lifespan, and decreased dg lifetime concluded as a shorter microgrid life expectancy; and (iv) rapid microgrid broke down and the crash of the key component inadvertently fastened the time to failure and gave rise to the early failure of a microgrid system. it is envisaged that the discussion in this study can provide useful mapped information for the researcher, stakeholder, operator, and other parties for thoroughly addressing various degradation and deterioration issues and anticipating the early termination of the microgrid system. (author) journal of mechatronics, electrical power, and vehicular technology e-issn 2088-6985 https://mev.lipi.go.id p-issn 2087-3379 vii keywords: expected energy not achieved; shorter lifespan; early failure; microgrid termination; loss of power supply. sujito a, ridho riski hadi b, langlang gumilar a, abdullah iskandar syah b, moh. zainul falah b, tran huy duy c (a intelligent power and advance energy system, jurusan teknik elektro, universitas negeri malang, indonesia; b electrical engineering, electrical engineering department, universitas negeri malang, indonesia; c electrical engineering department, dalat university, vietnam) long-term forecasting for growth of electricity load based on customer sectors journal of mechatronics, electrical power, and vehicular technology, 2022, vol. 13, no. 2, p. 214-221, 2 ill, 7 tab, 37 ref. the availability of electrical energy is an important issue. along with the growth of the human population, electrical energy also increases. this study addresses problems in the operation of the electric power system. one of the problems that occur is the power imbalance due to scale growth between demand and generation. alternative countermeasures that can be done are to prepare for the possibility that will occur in the future or what we are familiar with forecasting. forecasting using the multiple linear regression method with this research variable assumes the household sector, business, industry, and public sectors, and is considered by the influence of population, gross regional domestic product, and district minimum wage. in forecasting, it is necessary to evaluate the accuracy using mean absolute percentage error (mape). mape evaluation results show a value of 0.142 % in the household sector, 0.085 % in the business sector, 1.983 % in the industrial sector, and 0.131 % in the total customer sector. (author) keywords: district minimum wage; gross regional domestic product; long-term forecasting; mean absolute percentage error; multiple linear regression. foreword from editor-in-chief list of contents mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.35-46 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: h. luthfiyah et al., “an optimized stator and rotor design of squirrel cage induction motor for emu train,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 35-46, july 2023. an optimized stator and rotor design of squirrel cage induction motor for emu train hilda luthfiyah a, *, okghi adam qowiy a, arga iman malakani b, dwi handoko arthanto c, fauzi dwi setiawan a, teddy anugrah ramanel d, gilang mantara putra e, syamsul kamar a, asep andi suryandi f, g a research center for transpostation technology, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia b research center for hydronamics technology, national research and innovation agency (brin) jl. hidrodinamika, surabaya, 60112, indonesia c research center for accelarator technology, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia d research center for energy conversion and conservation, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia e research center for artificial intelligence and cyber security, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia f research center for process and manufacturing industry technology, national research and innovation agency (brin) puspiptek, south tangerang city, indonesia g electrical and electronic engineering, the university of manchester office 40, mecd eng a 5th floor, po box 88, manchester m13 9pl, united kingdom received 17 november 2022; 1st revision 21 december 2022; 2nd revision 6 february 2023; accepted 3 march 2023; published online 31 july 2023 abstract this paper aims to objectively calculate the 480-kw squirrel cage induction motor (scim) design for the electric multiple unit (emu) trains. this is done by optimizing the stator slot and rotor slot design to get efficiency and power factor targets. the stator slot design is achieved by limiting the width and height of the stator slot pitch according to the specified range. a depthto-width ratio is used according to the range to optimize the design of the rotor bar slot. the design process of the induction motor consists of three steps: it determines the specification design target, calculates the specified parameters of the induction motor, and simulates the design to obtain the most optimal motor design using ansys maxwell. the simulation performance values obtained an efficiency of 92.547 % and a power factor of 0.915. this value is obtained from the optimization of the rotor slot and has met the minimum requirements of efficiency and power factor in designing a scim. the design proposed in this paper can be developed and applied in the indonesian domestic railway manufacturing industry. copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: squirrel cage induction motor; stator slot; rotor slot; motor efficiency; motor power factor. i. introduction railways with electric-powered trains use a distributed traction system known as electric multiple unit (emu). emu has several advantages, such as low energy consumption with the pollutionfree operation, good traction and braking performance, and operational reliability with optimal redundancy [1][2]. an induction motor (im) is a type of motor that is reliable to be applied in emu trains. this characteristic has made them the first choice of train designers and builders [3]. most im are chosen as electric vehicle engines because they are known for their sturdy construction, cheaper production costs, and ease of control [4]. in particular, the type of motor widely used for the train propulsion system is squirrel cage induction motor (scim). the advantage of scim is it has a smaller size and lighter weight than other types of motors, e.g. dc motor, wound * corresponding author. tel: +62-8563159453 e-mail address: hilda.luthfiyah@brin.go.id https://dx.doi.org/10.14203/j.mev.2023.v14.35-46 https://dx.doi.org/10.14203/j.mev.2023.v14.35-46 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev/index https://dx.doi.org/10.14203/j.mev.2023.v14.35-46 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2022.v13.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ mailto:hilda.luthfiyah@brin.go.id h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 36 rotor induction motor (wrim), and wound rotor synchronous motor (wrsm). in addition, scim has minimal ground disturbance for the traction motor due to the removal of brushes and commutator. the effect of removing the instrument is that it can save costs and reduce maintenance time [5]. research on the optimization of im design in electric-powered trains has grown rapidly. among them is im design optimization on stator slots, rotor slots, and rotor shafts with finite element analysis (fem) analysis using matlab [6][7][8]. with the same tools matlab, im optimization was done with air gap variations to get the best efficiency and power factor [9]. in other research, design optimization im was done by selecting slot types and materials to achieve optimal motor efficiency and performance using different tools, namely ansys maxwell [10][11]. another method was introduced for motor optimization using the taguchi and fuzzy optimization method sequentially [12]. in indonesian railways, an electric-based railway drive system has been implemented. the current emu trains in indonesia use traction motors with output power 100 kw and 180 kw [13][14]. another type of electric train used in indonesia is diesel electric multiple unit (demu) which uses a traction motor with 550 kw output power [15]. high speed train (hst) in the world, which has a speed of 250300 km/h, uses traction motor with specifications between 300-1200 kw [16][17][18]. in indonesia, the jakarta-bandung high-speed train is currently being built with a maximum operating speed of 350 km/h which is fully managed by the chinese government [19]. however, in indonesia itself there is no research on hst designation im that accommodates indonesia hst specification, namely with a speed of 250-300 km/h. based on these findings, this research design and optimize a 480 kw scim to be applied as a traction motor of an emu train. by optimizing the scim design, it can achieve maximum efficiency and power factor targets. the 480 kw scim is the first emu-type induction motor for hst in the indonesian domestic railway manufacturing industry. the design process for a scim through stator and rotor slot geometry optimization to get the best motor performance based on efficiency and power factor values with minimum targets that must be achieved. the formulated scim design was then validated using the ansys maxwell. the simulation results of the proposed design have been proven to work on target. this paper is organized as follows. an explanation of the steps in optimizing the design of an induction motor with its mathematical calculations, along with the characteristics of the induction motor as a railway traction motor, is presented in section ii. section iii reviews the results of the design optimization method and is reported along with the electromagnetic-thermal analysis of the optimal solution. finally, the conclusion and points for some future extensions are given in section iv. ii. materials and methods a. design stage im design is a process of iteration to achieve the expected target. the optimization is completed by analytical or numerical solution techniques. the optimization method uses the initial design and constraints to solve the problem. in science, parametric solutions with limited steps or iterative methods converging to heuristic solutions or algorithms satisfying proximate solutions are used. however, several parameters are allowed to be optimized at the same time. to find the highest performance, this paper uses two optimization steps according to the complete design procedure [20], as shown in figure 1. 1. design target setting: the traction motor is used to drive the emu train. the design must achieve the appropriate performance, such as target torque, maximum power, and shaft speed range. 2. selection of motor type and size: the selected motor must have high efficiency and be easy to maintain. the size of the motor will affect the speed, torque, and power. a comparison of similar traction motors was conducted, then confirmed with the available space in the bogie of a high-speed emu train. 3. mathematical modeling of the technical specifications of the traction motor: the derivation of the equation of the traction motor is used for calculations in obtaining the stator and rotor designs, which are the main components of the traction motor. when selecting the number of poles and slots of the traction motor, it is necessary to consider the rotational speed, harmonic slots in the air gap, and leakage inductance. then the number of poles selected must be able to be implemented at the targeted speed and torque. in addition, a factor is used in determining the number of figure 1. research methodology flowchart h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 37 poles and slots in the traction motor, namely the dimensions motor. 4. optimization of the stator and the rotor topology: first, the volume size on the stator is calculated. then, select and count the number of stator slots, the number of slot conductors, coils, and windings. the design of this stator includes the dimensions of the stator slot. perform the calculation of the length of the air gap. then, the diameter of the rotor, the number of rotor slots, and the dimensions of the shaft. this rotor design also includes the rotor slot sizes in the selected type. 5. im performance analysis: im performance analysis to get an idea of the traction motor design performance. motor performance assessment is taken from the efficiency and power factor generated when the traction motor is simulated. 6. design evaluation: design evaluation is used to determine the feasibility of the traction motor technical specifications that have been prepared. b. specification design target based on performance requirements and field conditions, the general technical specifications of im as a traction system can be seen in table 1. the scim design specifications in table 1 are sourced from similar research and input from expert traction motor engineers. some of the factors considered in designing an im are that the motor should have efficiency and power factor according to the requirements for a high starting torque. to achieve the performance, it is necessary to define the details of the induction motor design: the length of the stator, the diameter of the stator, the width of the air gap, the shape of the stator slot, and the rotor slot, and others [21][22]. this process can be seen in the research methodology in figure 1. c. mathematical modelling the im calculation uses several stages of the equation [23][24]. calculation of input from apparent power, as equation (1), 𝑆 = ℎ.𝑝.𝑥 0.746 𝜂 cos𝜙 = 𝑃 𝜂 cos𝜙 (1) where 𝑆 is apparent power in kva, 𝑃 is active power in kw, 𝜂 is efficiency, and cos 𝜙 is power factor. synchronous rotation speed in rpm is calculated with equation (2), 𝑛𝑚 = 2.60.𝑓 𝑝 (2) where 𝑛𝑚 is synchronous rotation speed in rpm, 𝑓 is frequency in hz, and 𝑝 is number of poles. count rated torque, which is defined as equation (3) 𝑇𝑠 = 5250 𝑥 𝑆 𝑛𝑚 (3) measuring the main dimensions of the motor, namely the diameter and length of the motor, using equation (4) 𝐷2𝑙𝑎 = 𝑣𝑇𝑇𝑠 (4) where 𝐷 is stator inner diameter, 𝑙𝑎 is stacking length, 𝑣𝑇 is volume constant, and 𝑇𝑠 is rated torque. 1) stator topology stator bore diameter is defined by equation (5) 𝐷 = 𝐷𝑜−0.647 1.175+1.03/𝑝 (5) where 𝐷 is stator inner diameter, 𝐷𝑜 is outside diameter, and 𝑝 is number of poles. determining the number of stator slots through equation (6) 𝑆1 = 𝑝 𝑥 𝑞 𝑥 𝑚 (6) where 𝑆1 is the number of stator slots, 𝑝 is the number of poles, 𝑞 is the number of pole/slot/phase, and 𝑚 is the number of phases. measuring the stator slot pitch, that is the distance measured between the stator gear and the slot along the diameter of the stator hole. stator slot pitch (𝜆1 ) is obtained through equation (7) 𝜆1 = 𝜋𝐷 𝑆1 (7) the stator slot width (bs1) obtained by the range of limitations of 𝜆1 using equation (8) 0.5 𝜆1 ≤ bs1 ≤ 0.6𝜆1 (8) as for getting the stator slot depth (ds1) on the following stator slot width range using equation (9) 2bs1 ≤ ds1 ≤ 4bs1 (9) based on figure 2, the width of the stator slot consists of a conductor of coil side and slot liner. the table 1. design specifications of scim parameter type/value type scim number of phases 3 phases number of poles 4 poles input voltage 2300 vac output capacity 480 kw frequency 85 hz rotational speed 5600 rpm cooling forced ventilation operating temperature 75 oc figure 2. stator slot design h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 38 coil side consists of two sides with a liner slot that functions as ground insulation on the stator slot component. while the height of the slot is composed of a conductor of coil side, coil separator, slot liner, and slot wedge. from figure 2 to get the stator slot width ( bs1 ) and the stator slot depth ( ds1 ) in equation (8). 2) rotor topology to get the dimensions of the rotor, it begins by determining the number of rotor slots through equation (10) 𝑆1 − 𝑆2 = ±3𝑘𝑝 (𝑘 = 1, 2, 3, . . . ) (10) where 𝑆2 is the number of rotor slots. the air gap affects the magnetization of the required current. the distance of the air gap, obtained by equation (11) 𝛿 = 0.2 + 2√𝐷𝐷 (11) where 𝛿 is air gap distance, 𝐷 is stator inner diameter, and 𝐷 is the stator core length. rotor diameter (𝐷𝑟) obtained using equation (12) 𝐷𝑟 = 𝐷 − 2𝛿 (12) in figure 3, in designing an im, it is necessary to pay attention to the rotor width (br1, br2) and the rotor depth (dr1, dr2). the rotor slot in figure 3 is designed with the rotor slot open with the width of the rotor bar (br2) that must fit to avoid excessive rotor leakage reactance. designing the rotor slots must be precise so that the cross-sectional area of the rotor rod meets the tolerable current density. the current density of the rotor rod is affected by the height of the rotor bar slot (dr1, dr2). determine the height and width of the rotor slots by using a depthto-width ratio (rdw) with a range of 3 ≤ 𝑟𝑟𝑟 ≤ 6 through equation (13) and equation (14) br1 = � 𝑠𝑏 𝑟𝑟𝑟 � 1/2 (13) dr1 − dr2 = (𝑟𝑟𝑟𝑟𝑏)1/2 (14) where br1 is the rotor bar width, dr1 − dr2 is the rotor bar depth, 𝑟𝑟𝑟 is the depth-to-width ratio and 𝑟𝑏 is the cross-section area of the rotor bar. d. induction motor characteristics the performance of im is usually measured on torque and output power. the graph is divided into three parts: when the torque is constant, the power is constant, and the slip is limited, as shown in figure 4. when the torque region is constant, the voltage-frequency ratio (v/f) is constant; it causes the engine output power to increase linearly proportional to the increase in supply power. when the supply frequency continues to increase, it results in a constant motor current. at the same time, the air gap flux decreases; this condition occurs when the power area is constant. when the slip area is limited, when the engine is operating, it will maximize the torque output and reduce the motor's outgoing power. the acceleration of the traction system ability on the incline and maximum speed is characteristic of the torque and power of the induction motor [24][25]. figure 3. rotor slot design figure 4. induction motor performance characteristics h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 39 as an electric traction system, the induction motor must meet the following requirements: starting and rising at low speed, it should have high torque, while at high speed in the cruising area, it should have high power; fast torque response with high efficiency when the speed and torque range is wide; reliable and resistant in various operating conditions of the train and when regenerative braking has high efficiency [26][27]. the characteristics of im performance measured by ansys maxwell are power factor, efficiency, and developed torque. the input power factor is equation (15) 𝑃𝑃 = cos(∠ ⩂1− ∠ṽ1) (15) pf is the power factor, ∠ ⩂1 is phase voltage angle, and ∠ṽ1 is phase current angle. the efficiency is the percentage ratio of output and input power using equation (16) 𝜂 = 𝑃𝑜 𝑃𝑖 𝑥 100% (16) 𝜂 is efficiency, 𝑃𝑜 is output power, and 𝑃𝑖 is input power. developed torque is obtained by dividing developed power by shaft speed using equation (17) 𝑇𝑟 = 𝑃𝑑 𝜔𝑚 (17) 𝑇𝑟 is developed torque, 𝑃𝑟 is developed power, and 𝜔𝑚 is shaft speed. requirements on the design of the 480-kw scim: • η ≥ 90 % • pf ≥ 0.85 • pout = 480 kw iii. results and discussions a. initial design the design specifications of the scim in table 1 are then simulated and validated. this motor is given a dimension limitation of 500 mm. the minimum requirement for the motor is an efficiency value of 90 % with a minimum power factor of 0.85. then the motor is modeled using the derivation results of equation (1) until equation (17). so that from the results of the mathematical modeling above, we get the geometric dimensions of the stator slots and rotor slots. figure 5 is a description of the cross-sectional geometry type of the stator slots, where in ansys rmxprt module is referred to type 6. this model is used because it makes it easier in production or manufacturing. in the stator slot optimization test, the variables that must be considered are hs0, hs1, hs2 as the height of the stator slot. the stator slot widths are bs1 and bs2. table 2 being the stator slot design specification to be verified and validated is obtained from equation (8) and equation (9). the dimensions of the stator slots in table 2 are obtained from the calculation of the parts of the slot stators, which can be seen in figure 2. furthermore, in the motor design, the crosssectional geometry type of the rotor slot from type 4 in ansys rmxprt is shown in figure 6. in the rotor slot, the height of the rotor is divided into three parts, namely hr0, hr1, and hr2. as for the width of the rotor, it consists of br0, br1, and br2. in detail, the dimensions of each variable can be seen in table 3. detailed dimensions of the rotor slot are obtained from equation (13) and equation (14). based on the scim design specification data shown in table 1, the dimensions of the stator slot in table 2 and the rotor slots in table 3, simulations were carried out using ansys maxwell. this simulation is used to obtain scim performance values at the initial design. the result indicates that to get an output power of 480 kw; the required input power is 519.78 kw. then, the efficiency value is obtained 92.35 %, pf of 0.90, and mechanical shaft torque of 1807.44 nm. table 2. stator slot dimension name value unit hs0 0.4 mm hs1 3.2 mm hs2 40 mm bs1 16 mm bs2 13 mm table 3. rotor slot dimension name value unit hr0 3 mm hr1 0 mm hr2 43 mm br0 4 mm br1 7 mm br2 7 mm air gap 1 mm figure 6. rotor slot geometry type figure 5. stator slot geometry type h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 40 b. optimize stator slot and rotor slot the iteration to obtain the best im performance was carried out by changing the design of the stator slot: the size of the depth and width of the stator slot (hs2 and bs2), as shown in figure 5. the hs2 and bs2 values are obtained from the range of the stator slot width values (bs1) function given by equation (8). the value of bs2 is changed to be the same as bs1. design optimization of stator slot width (bs2) is in the range of 0.5𝜆1 , 0.55𝜆1 , 0.6𝜆1 acccording equation (8). then, the stator slot depth range (ds1) is about the depth of hs2 obtained from the overall stator slot height size minus the stator wedge slot size. the stator wedge slot is 3.615 mm. iteration of the motor stator slot design to get the best motor performance in the motor depth range (hs2), equation (9) with range 2bs1, 3bs1, and 4bs1. the simulations were carried out without changing the rotor slot design shown in table 3. the simulations results in motor performance characteristics that can be seen in table 4. from table 4, changes in the dimensions of the stator slots (hs2 and bs2) affect the efficiency and power factor. with an hs2 value of 24 mm and a bs2 of 13 mm, the smallest efficiency value is 87.143 %, but the pf value is 0.913. on the other hand, the largest hs2 value is 49 mm, with a bs2 of 13 mm. the highest efficiency value is 92.477 %, with the lowest pf is 0.884. then, the rotor slot design optimization is done to get the best induction motor performance. the variables that affect the rotor design are the width and height of the rotor. the induction motor rotor slot has a bar depth-to-width ratio (rdw) ratio in 3 rdw ≤ 6. an optimization test to get the rotor bar height value is obtained by multiplying the rdw variable per one level, which is 3, 4, 5, and 6. meanwhile, the rotor width is obtained by dividing rdw by the rotor bar area. the rdw value used has the same variables, namely 3, 4, 5, and 6. the optimization of the rotor slot using the stator slot design is in table 2. the simulation results of the design optimized rotor slot can be seen in table 5. from table 5, for the rotor slot design, the optimum design was obtained by setting the motor's efficiency target to above 90 % and pf 0.85. the highest efficiency value is 92.547 %, with a pf value is 0.915. changes in hr2, br0, and br2 resulted in an efficiency greater than 92 %. shaft torque is rated at ±1804-1806 nm with a minimum pf in the range of 0.89 to 0.91. the optimized design has reached the minimum required target from this rotor slot simulation. c. performance characteristics analysis table 6 contains a comparison of motor performance values resulting from the optimization of rotor slots and stator slots. the dimensions of the stator slot and rotor slot in the initial design and s6 resulted in efficiency values of 92.353 % and 92.712 %, with a pf of less than 0.9. meanwhile, during the optimization of stator slots and rotor slots in s2, the lowest efficiency value was 87,143 %, with a fairly high pf of 0.913. the most optimal geometric dimensions of stator and rotor slots were obtained at r6 with an efficiency value of 92.547 %, pf 0.915, and the lowest rated slip of 0.005. this rated slip value is close to zero, which means that the mechanical rotational speed will approach the synchronous speed in this operation. the simulation uses the ansys maxwell analytical tool to obtain the characteristics of the im. figure 7 shows the visualization of the magnetic flux density and figure 8 shows flux lines from the most optimal scim design (r6). magnetic flux is defined as the number of magnetic force lines passing through a surface. figure 7 shows that at a speed of 2539.2 rpm and a rotor position of 83.52 degrees, the largest magnetic flux density value is 2.4286 tesla. based on figure 7 and figure 8, it can be compared that when the lines of magnetic force increase, the value of the magnetic flux density also increases. the magnetic flux in an induction motor is table 4. optimize stator slot geometry no hs2 bs2 shaft torque (nm) η (%) pf s1 21 13 1809.50 87.211 0.915 s2 24 13 1808.01 87.143 0.913 s3 33 13 1808.21 91.421 0.904 s4 35 13 1806.76 91.805 0.902 s5 40 13 1807.44 92.353 0.898 s6 44 13 1806.64 92.712 0.895 s7 49 13 1808.79 92.477 0.884 table 5. optimize rotor slot geometry no hr2 br0 br1 = br2 shaft torque (nm) η (%) pf r1 35 5 8 1807.87 92.408 0.912 r2 35 5 9 1806.27 92.475 0.915 r3 35 5 10 1803.97 92.527 0.917 r4 39 5 8 1806.29 92.432 0.908 r5 39 5 9 1806.72 92.497 0.912 r6 39 5 10 1805.38 92.547 0.915 h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 41 generated from the current flowing in the stator coil. the magnitude of the current that varies at any time on each phase in the stator coil produces a different magnetic flux, as seen in figure 7. there are areas with different colors. with the magnetic flux in the stator coil, a current will be induced in the rotor, as shown in the magnetic flux line in figure 8. as a result of the current in the rotor and the magnetic field in the stator, it can rotate the rotor. figure 9 shows the value of the magnetic flux density in the air gap between the stator and rotor sections. the magnetic flux density at the ends of the stator and rotor can reach a value of 2.4286 tesla, which is the largest value. this can be due to the largest magnetic field induction found in that part. in the air gap section, there is also a magnetic flux value because that section is also passed by magnetic field lines. table 6. simulation of scim parameters initial design s2 s6 r6 stator slot geometry hs0 (mm) 0.4 0.4 0.4 0.4 hs1 (mm) 3.2 3.2 3.2 3.2 hs2 (mm) 40 24 44 40 bs1 (mm) 16 16 16 16 bs2 (mm) 13 13 13 13 rotor slot geometry hr0 (mm) 3 3 3 3 hr1 (mm) 0 0 0 0 hr2 (mm) 43 43 43 39 br0 (mm) 4 4 4 4 bs1 (mm) 7 7 7 7 bs2 (mm) 7 7 7 7 performance input power (kw) 519.78 550.68 518.124 518.72 output power (kw) 480.03 479.88 480.363 480.058 mechanical shaft torque (nm) 1807.44 1808.01 1808.64 1805.38 efficiency (%) 92.353 87.143 92.712 92.547 power factor 0.899 0.913 0.895 0.915 rated slip 0.006 0.007 0.006 0.005 rated shaft speed (rpm) 2536.17 2534.57 2536.22 2539.2 figure 7. magnetic flux density of the im design h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 42 figure 10 shows the graph of the flux linkage on the stator coil of an scim r6 in table 6. flux linkage is defined as the value of the magnetic flux through a coil. the graph shows an average linkage flux value of ±3.20 wb. in addition, it can be observed that there is a shift in the phase angle due to the difference in the phase angle of the current flowing in the stator coil in the form of a 3-phase electric current. figure 11 shows the graph of core loss on an scim r6. core loss is defined as losses in iron which is the total of eddy current losses, hysteresis losses, and additional/excess losses. based on the graph in figure 5, it can be observed that at the beginning of the rotation, the core loss value is high, and it decreases when it reaches a steady state. figure 12 shows the graph of the losses in the scim r6 design such as the core loss is losses in iron, the solid loss is electrical losses for “solid” or “single”” type conductors, the stranded loss is ohmic or resistance losses of “stranded” type conductors for a 3-phase machine, and mechanical loss in the simulation is losses in the shaft of the motor. in figure 12, it can be observed that the value of the losses fluctuates at the beginning of the motor rotation and decreases when it reaches a steady state. figure 8. magnetic flux lines of the im design figure 9. air gap flux density of the im design h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 43 figure 13 shows the average loss value of the scim r6 design. the average total motor losses value is 16.8167 kw. the average total loss value is the sum of the average core loss, solid loss, stranded loss, and mechanical loss, as shown in table 7. basically, the calculation of the core loss depends on the particular steel type and the sheet thickness. the solid loss depends on the distribution of the eddy current density and stranded loss depends on the resistances of the coils that influence of coil wire length and wire cross-section.the performance characteristics of the torque-speed motor is shown in figure 14. when the speed is low, between 115 to ±2500 rpm, which indicates a constant torque region, the torque is in a high and constant condition of figure 10. flux linkages of the im design figure 11. core loss of the im design figure 12. losses of the im design table 7. motor induction losses no losses value (kw) 1 average core loss 3.3913 2 average solid loss 2.0772 3 average mechanical loss 0 4 average stranded loss 11.3482 average total losses 16.8167 h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 44 ±1800 nm. then, it decreases when the speed is above 2500 rpm. in figure 15, the power-speed performance shows three states. when the speed is 115 to ±2500 rpm, the power increases from 21 to 480 kw. when the power increases from 2500 rpm to 4100 rpm, the power states at a constant value 480 kw at constant power region. then, the rotational speed is above 4929 rpm; the power shows a downward trend representing slip limited region. besides that, ansys maxwell produces a flat cross-sectional shape from scim which can be seen figure 13. average losses of the im design figure 14. torque-speed characteristics of the optimal im design figure 15. power-speed characteristics of the optimal im design h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 45 in figure 16. the figure shows the core part of scim consists of stator cores and rotor cores. a comprehensive 3d model of the scim has been created too, which can be seen in figure 17. the simulation shows a visualization of the dimensions of the stator, rotor, winding stator, rotor bar, and shaft parts. iv. conclusion in this research, we have shown that the in this paper, the scim design has been conducted by optimizing the stator slot and rotor slot design to get efficiency and power factor targets. the motor with specifications: 3-phase, 4-pole, 480 kw output power, 2300 vac input voltage operated at a frequency of 85 hz. this design has been simulated using ansys maxwell. the stator-rotor slot design is optimized by changing the stator-rotor slot size based on each parameter's range limit. from the simulation, it is found that optimization on the rotor slot affects the efficiency of the motor to be better than optimization on the stator slot. the best scim performance value obtained is a size geometry slot stator hs0 of 0.4 mm, hs1 of 3.2 mm, hs2 of 40 mm, bs1 of 16 mm, and bs2 of 13 mm. the geometry size of the rotor slot is hr0 of 3 mm, hr1 of 0 mm, hr2 of 39 mm, br0 of 5 mm, br1 of 10 mm, and br2 of 10mm. from the size of the stator slot and the rotor slot dimensions, the obtained efficiency is 92.547 % with a power factor of 0.915, a rated shaft speed of 2536.17 rpm, and a rated slip of 0.005. the data shows the highest efficiency value, the optimal power factor value, with the smallest slip rated value. from the optimization to get the best scim design performance, the minimum losses are obtained and produce the optimal dimension of scim. hopefully, the result from this study can be developed and applied in the indonesian domestic railway manufacturing industry, especially for emu trains. acknowledgements this work was partly supported by research center for transportation technology and research center for process and manufacturing industry technology, national research and innovation agency, indonesia. declaration author contribution h. luthfiyah: writing original manuscript, writing review & editing, conceptualization, formal analysis, investigation, visualization, supervision. o.a. qowiy: writing original draft, writing review & editing, conceptualization, investigation, validation, data curation. a.i malakani: formal analytics, resources, software, conceptualization, data curation, visualization, reviewing & editing. d.h. arthanto: formal analysis, resources, software, conceptualization, visualization. f.d. setiawan: formal analysis, resources, software, visualization, writing review & editing. t.a. ramanel: formal analysis, resources. g.m. putra: formal analysis, resources, software, review & editing. s. kamar: formal analysis, resources, oversight, funding acquisition. a.a. suryandi: review & editing, supervision. figure 16. scim flat cross section figure 17. 3d model of scim h. luthfiyah et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 35-46 46 funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] k. sato, h. kato, and t. fukushima, “outstanding technical features of traction system in n700s shinkansen new generation standardized high speed train,” ieej journal of industry applications, vol. 10, no. 4, pp. 402–410, 2021. [2] z. wu, c. gao, and t. tang, “an optimal train speed profile planning method for induction motor traction system,” energies (basel), vol. 14, no. 16, p. 5153, aug. 2021. [3] s. nategh, d. lindberg, r. brammer, a. boglietti, and o. aglen, “review and trends in traction motor design: electromagnetic and cooling system layouts,” in 2018 xiii international conference on electrical machines (icem), pp. 2600–2606, 2018. [4] w. cai, x. wu, m. zhou, y. liang, and y. wang, “review and development of electric motor systems and electric powertrains for new energy vehicles,” automotive innovation, vol. 4, no. 1, pp. 3–22, 2021. [5] s. nategh et al., “a review on different aspects of traction motor design for railway applications,” ieee trans ind appl, vol. 56, no. 3, pp. 2148–2157, 2020. [6] j. liang, j. w. jiang, b. bilgin, and a. emadi, “shaft design for electric traction motors,” ieee transactions on transportation electrification, vol. 4, no. 3, pp. 720–731, 2018. [7] r. ikeda, s. yusya, and k. kondo, “study on design method for increasing power density of induction motors for electric railway vehicle traction,” in 2019 ieee international electric machines & drives conference (iemdc), pp. 1545–1550, 2019. [8] s. enache, a. campeanu, m. a. enache, i. vlad, and m. popescu, “new aspects in optimal design of asynchronous motors used in light railway traction,” in 2020 international symposium on power electronics, electrical drives, automation and motion (speedam), pp. 606–611, 2020. [9] a. a. suryandi, c. s. a. nandar, d. r. mandasari, and k. yulianto, “a 250 kw three phase induction motor design for electric bow thruster,” in 2018 international conference on electrical engineering and computer science (icecos), pp. 247–252, 2018. [10] t. m. masuku, r.-j. wang, m. c. botha, and s. gerber, “design strategy of traction induction motors,” in 2019 southern african universities power engineering conference/robotics and mechatronics/pattern recognition association of south africa (saupec/robmech/prasa), pp. 316–321, 2019. [11] f. d. wijaya, i. imawati, m. yasirroni, and a. i. cahyadi, “effect of different core materials in very low voltage induction motors for electric vehicle,” journal of mechatronics, electrical power, and vehicular technology, vol. 12, no. 2, pp. 95–103, dec. 2021. [12] x. sun, z. shi, and j. zhu, “multiobjective design optimization of an ipmsm for evs based on fuzzy method and sequential taguchi method,” ieee transactions on industrial electronics, vol. 68, no. 11, pp. 10592–10600, 2021. [13] a. setiyoso, h. hindersyah, a. purwadi, and a. rizqiawan, “design of traction motor 180kw type scim for krl (emu) jabodetabek re-powering project,” in 2014 international conference on electrical engineering and computer science (iceecs), pp. 341–344, 2014. [14] a. setiyoso, k. hadi, l. n. mulyani, r. sipahutar, and y. p. p. kesawa, “design of traction motor 100kw for lrt rolling stock in jabodebek – indonesia,” in 2022 7th international conference on electric vehicular technology (icevt), pp. 153– 156, 2022. [15] a. s. hartono, roosdiatmoko, t. widodo, a. iswanto, y. haroen, and p. a. dahono, “development of new drive system of diesel electric multiple unit (demu) for indonesia railway,” in 4th ieee international conference on power electronics and drive systems. ieee peds 2001 indonesia. proceedings (cat. no.01th8594), vol. 2, pp. 489–493, 2001. [16] m. torrent, j. perat, and j. jiménez, “permanent magnet synchronous motor with different rotor structures for traction motor in high speed trains,” energies (basel), vol. 11, no. 6, p. 1549, jun. 2018. [17] h. zhao, j. liang, and c. liu, “high-speed emus: characteristics of technological development and trends,” engineering, vol. 6, no. 3, pp. 234–244, 2020. [18] g. wu et al., “pantograph–catenary electrical contact system of high-speed railways: recent progress, challenges, and outlooks,” railway engineering science, vol. 30, no. 4, pp. 437–467, 2022. [19] a. purba, “the challenge of developing high-speed rail projects: recent evidence from developing countries,” international journal of geomate, vol. 18, no. 70, pp. 99–105, 2020. [20] d.-k. lee and j.-s. ro, “analysis and design of a highperformance traction motor for heavy-duty vehicles,” energies (basel), vol. 13, no. 12, p. 3150, jun. 2020. [21] m. j. akhtar and r. k. behera, “optimal design of stator and rotor slot of induction motor for electric vehicle applications,” iet electrical systems in transportation, vol. 9, no. 1, pp. 35– 43, mar. 2019. [22] p. irasari, k. wirtayasa, p. widiyanto, m. f. hikmawan, and m. kasim, “characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications,” journal of mechatronics, electrical power, and vehicular technology, vol. 12, no. 1, pp. 1–9, jul. 2021. [23] j. j. cathey, electric machines: analysis and design applying matlab. mcgraw-hill, 2001. [24] i. boldea and s. a. nasar, “the induction machines design handbook,” crc press, 2018. [25] n. zhao and n. schofield, “an induction machine design with parameter optimization for a 120-kw electric vehicle,” ieee transactions on transportation electrification, vol. 6, no. 2, pp. 592–601, 2020. [26] s. j. rind, m. jamil, and a. amjad, “electric motors and speed sensorless control for electric and hybrid electric vehicles: a review,” in 2018 53rd international universities power engineering conference (upec), 2018, pp. 1–6. [27] k. s. mohammad and a. s. jaber, “comparison of electric motors used in electric vehicle propulsion system,” indonesian journal of electrical engineering and computer science, vol. 27, no. 1, pp. 11–19, jul. 2022. https://mev.lipi.go.id/ https://doi.org/10.1541/ieejjia.20012560 https://doi.org/10.1541/ieejjia.20012560 https://doi.org/10.1541/ieejjia.20012560 https://doi.org/10.1541/ieejjia.20012560 https://doi.org/10.3390/en14165153 https://doi.org/10.3390/en14165153 https://doi.org/10.3390/en14165153 https://doi.org/10.1109/icelmach.2018.8506817 https://doi.org/10.1109/icelmach.2018.8506817 https://doi.org/10.1109/icelmach.2018.8506817 https://doi.org/10.1109/icelmach.2018.8506817 https://doi.org/10.1109/icelmach.2018.8506817 https://doi.org/10.1007/s42154-021-00139-z https://doi.org/10.1007/s42154-021-00139-z https://doi.org/10.1007/s42154-021-00139-z https://doi.org/10.1007/s42154-021-00139-z https://doi.org/10.1109/tia.2020.2968414 https://doi.org/10.1109/tia.2020.2968414 https://doi.org/10.1109/tia.2020.2968414 https://doi.org/10.1109/tte.2018.2859409 https://doi.org/10.1109/tte.2018.2859409 https://doi.org/10.1109/tte.2018.2859409 https://doi.org/10.1109/iemdc.2019.8785087 https://doi.org/10.1109/iemdc.2019.8785087 https://doi.org/10.1109/iemdc.2019.8785087 https://doi.org/10.1109/iemdc.2019.8785087 https://doi.org/10.1109/speedam48782.2020.9161847 https://doi.org/10.1109/speedam48782.2020.9161847 https://doi.org/10.1109/speedam48782.2020.9161847 https://doi.org/10.1109/speedam48782.2020.9161847 https://doi.org/10.1109/speedam48782.2020.9161847 https://doi.org/10.1109/icecos.2018.8605242 https://doi.org/10.1109/icecos.2018.8605242 https://doi.org/10.1109/icecos.2018.8605242 https://doi.org/10.1109/icecos.2018.8605242 https://doi.org/10.1109/icecos.2018.8605242 https://doi.org/10.1109/robomech.2019.8704761 https://doi.org/10.1109/robomech.2019.8704761 https://doi.org/10.1109/robomech.2019.8704761 https://doi.org/10.1109/robomech.2019.8704761 https://doi.org/10.1109/robomech.2019.8704761 https://doi.org/10.14203/j.mev.2021.v12.95-103 https://doi.org/10.14203/j.mev.2021.v12.95-103 https://doi.org/10.14203/j.mev.2021.v12.95-103 https://doi.org/10.14203/j.mev.2021.v12.95-103 https://doi.org/10.14203/j.mev.2021.v12.95-103 https://doi.org/10.1109/tie.2020.3031534 https://doi.org/10.1109/tie.2020.3031534 https://doi.org/10.1109/tie.2020.3031534 https://doi.org/10.1109/tie.2020.3031534 https://doi.org/10.1109/iceecs.2014.7045274 https://doi.org/10.1109/iceecs.2014.7045274 https://doi.org/10.1109/iceecs.2014.7045274 https://doi.org/10.1109/iceecs.2014.7045274 https://doi.org/10.1109/iceecs.2014.7045274 https://doi.org/10.1109/icevt55516.2022.9924690 https://doi.org/10.1109/icevt55516.2022.9924690 https://doi.org/10.1109/icevt55516.2022.9924690 https://doi.org/10.1109/icevt55516.2022.9924690 https://doi.org/10.1109/icevt55516.2022.9924690 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.1109/peds.2001.975365 https://doi.org/10.3390/en11061549 https://doi.org/10.3390/en11061549 https://doi.org/10.3390/en11061549 https://doi.org/10.3390/en11061549 https://doi.org/10.1016/j.eng.2020.01.008 https://doi.org/10.1016/j.eng.2020.01.008 https://doi.org/10.1016/j.eng.2020.01.008 https://doi.org/10.1007/s40534-022-00281-2 https://doi.org/10.1007/s40534-022-00281-2 https://doi.org/10.1007/s40534-022-00281-2 https://doi.org/10.1007/s40534-022-00281-2 https://www.researchgate.net/publication/341796313_the_challenge_of_developing_high-speed_rail_projects_recent_evidence_from_developing_countries https://www.researchgate.net/publication/341796313_the_challenge_of_developing_high-speed_rail_projects_recent_evidence_from_developing_countries https://www.researchgate.net/publication/341796313_the_challenge_of_developing_high-speed_rail_projects_recent_evidence_from_developing_countries https://www.researchgate.net/publication/341796313_the_challenge_of_developing_high-speed_rail_projects_recent_evidence_from_developing_countries https://doi.org/10.3390/en13123150 https://doi.org/10.3390/en13123150 https://doi.org/10.3390/en13123150 https://doi.org/10.1049/iet-est.2018.5050 https://doi.org/10.1049/iet-est.2018.5050 https://doi.org/10.1049/iet-est.2018.5050 https://doi.org/10.1049/iet-est.2018.5050 https://doi.org/10.14203/j.mev.2021.v12.1-9 https://doi.org/10.14203/j.mev.2021.v12.1-9 https://doi.org/10.14203/j.mev.2021.v12.1-9 https://doi.org/10.14203/j.mev.2021.v12.1-9 https://doi.org/10.14203/j.mev.2021.v12.1-9 https://www.semanticscholar.org/paper/electric-machines%3a-analysis-and-design-applying-cathey/996b7c0db0331502ca58a9778b9d0ddd341944c5 https://www.semanticscholar.org/paper/electric-machines%3a-analysis-and-design-applying-cathey/996b7c0db0331502ca58a9778b9d0ddd341944c5 https://doi.org/10.1201/9781315222592 https://doi.org/10.1201/9781315222592 https://doi.org/10.1109/tte.2020.2993456 https://doi.org/10.1109/tte.2020.2993456 https://doi.org/10.1109/tte.2020.2993456 https://doi.org/10.1109/tte.2020.2993456 https://doi.org/10.1109/upec.2018.8541871 https://doi.org/10.1109/upec.2018.8541871 https://doi.org/10.1109/upec.2018.8541871 https://doi.org/10.1109/upec.2018.8541871 https://doi.org/10.11591/ijeecs.v27.i1.pp11-19 https://doi.org/10.11591/ijeecs.v27.i1.pp11-19 https://doi.org/10.11591/ijeecs.v27.i1.pp11-19 https://doi.org/10.11591/ijeecs.v27.i1.pp11-19 i. introduction ii. materials and methods a. design stage b. specification design target c. mathematical modelling 1) stator topology 2) rotor topology d. induction motor characteristics iii. results and discussions a. initial design b. optimize stator slot and rotor slot c. performance characteristics analysis iv. conclusion acknowledgements declaration author contribution funding statement competing interest additional information references mev journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 journal of mechatronics, electrical power, and vehicular technology e-issn: 2088-6985 p-issn: 2087-3379 mev.lipi.go.id doi: https://dx.doi.org/10.14203/j.mev.2023.v14.55-61 2088-6985 / 2087-3379 ©2023 national research and innovation agency this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/) mev is scopus indexed journal and accredited as sinta 1 journal (https://sinta.kemdikbud.go.id/journals/detail?id=814) how to cite: e. n. irawan et al., “analyzing the growth and trends of vertical axis wind turbine research: insight from a bibliometric study,” journal of mechatronics, electrical power, and vehicular technology, vol. 14, no. 1, pp. 55-61, july 2023. analyzing the growth and trends of vertical axis wind turbine research: insight from a bibliometric study elysa nensy irawan a, b, *, nuur wachid abdul majid c, liptia venica a, fahrur aslami d, goro fujita e a department of mechatronics and artificial intelligence, universitas pendidikan indonesia bandung, 40154, indonesia b functional control system, shibaura institute of technology tokyo, 135-8548, japan c department of system and information technology education, universitas pendidikan indonesia bandung, 40154, indonesia d department of computer engineering, universitas wiralodra indramayu, 45213, indonesia e department of electrical engineering, shibaura institute of technology tokyo, 135-8548, japan received 14 march 2023; 1st revision 25 may 2023; 2nd revision 31 may 2023; 3rd revision 6 june 2023; 4th revision 11 june 2023 accepted 13 june 2023; published online 31 july 2023 abstract bibliometric analysis research has been done for vertical axis wind turbine (vawt). this study aims to determine the growth of vawt research, the number of vawt studies in various countries and the most influential authors to find opportunities for research collaboration, and the challenges of future vawt research. research data was taken from scopus in 1801 articles from 1970-2021. the software used for data interpretation was vosviewer 1.6.19 and tableau public 2022.2. based on the analysis, vawt research has tended to increase from 1970-2021, although there was a decrease from 1987-2006. the country that has conducted the most vawt research is china, while the author with the highest number of citations is from italy. the most dominant research topic related to vawt research is computational fluid dynamics (cfd), which is 50.14 % of the total. a future challenge related to vawt research is finding a suitable turbulence model for each type of vawt or finding an airfoil optimization method so that a model with better performance is obtained. opportunities for research collaboration can be carried out with china or an author with the highest number of citations who has expertise in the field of cfd . copyright ©2023 national research and innovation agency. this is an open access article under the cc by-nc-sa license (https://creativecommons.org/licenses/by-nc-sa/4.0/). keywords: bibliometric analysis; tableau public 2022.2 software; vertical axis wind turbine (vawt); vosviewer 1.6.19 software. i. introduction development of renewable energy is currently increasing rapidly [1] due to the stated policies scenario (steps) policy which seeks to reduce carbon dioxide (co2) emissions by 55 % in 2030 compared to 1990 [2]. basically, many renewable energies are produced by various sources, such as the sun, wind, ocean waves, ocean currents, and so on [3]. in the asia pacific region, wind energy is a renewable energy source with great potential to be developed, even from 2008–2018, the development of wind energy has continued to increase [4]. especially in indonesia, the implementation of wind energy has increased every year since 2017 until now. moreover, president jokowi installed the largest wind energy installation in indonesia, with a capacity of 75 mw in july 2018 [5]. not only that, studies on the implementation of wind energy have been attempted in various fields, for example, at airports [6]. * corresponding author. tel: +62-83-856610862 e-mail address: elysanensy@upi.edu https://dx.doi.org/10.14203/j.mev.2023.v14.55-61 http://u.lipi.go.id/1436264155 http://u.lipi.go.id/1434164106 https://mev.lipi.go.id/mev https://mev.lipi.go.id/mev https://dx.doi.org/10.14203/j.mev.2023.v14.55-61 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://sinta.kemdikbud.go.id/journals/detail?id=814 https://crossmark.crossref.org/dialog/?doi=10.14203/j.mev.2017.v8.1-10&domain=pdf https://creativecommons.org/licenses/by-nc-sa/4.0/ e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 56 the challenge for the development of wind energy in indonesia is the relatively low wind speed [5]. in fact, to be able to rotate horizontal axis wind turbine (hawt) that is commonly developed in indonesia, wind speeds of 5–7 m/s are required [7]. however, there is a type of wind turbine that can rotate at lower wind speeds, namely the vertical axis wind turbine (vawt) [8]. according to [9], vawt has more advantages than hawt. however, the efficiency of vawt is still less than hawt. so, for vawt development, a lot of innovation is still needed to improve its performance. and currently, research is being intensively carried out to improve the performance of the vawt, as was done by [10][11][12]. so far, there are many methods that can be applied to determine ongoing research trends, for example, meta-analysis, literature review, mapping review, bibliometric analysis, and so on [13]. among all these methods, bibliometric analysis has advantages. for example, it can easily provide final information on research opportunities, can provide information on collaboration opportunities easily, and so on [14]. with these various advantages, bibliometrics is one of the most popular literature review methods and has been used in various fields, for example, electric vehicle control strategy [15], food studies [16], renewable energy [17], and so on. however, so far, there has been no bibliometric analysis in the field of vawt. therefore, this research was conducted on the topic of bibliometric analysis for vawt with the main objective of providing information to readers about the vawt research growth, the country that does the most research on vawt, opportunities for vawt research collaboration, and challenges to future vawt research. ii. materials and methods bibliometric analysis is a method for identifying research trends from a specific topic quantitatively [18]. there are three main stages in bibliometric study, as shown in figure 1. based on figure 1, the most important thing is data visualization. the author can use many software to interpret data, but in this case, the author uses vosviewer 1.6.19 and tableau public 2022.2 software. then data collection can be obtained from many sources, but in this case, the author uses scopus. vawt research publication data were obtained from scopus from the beginning until 2021. scopus was used as the data source in this study because scopus provides high-quality data for bibliometric analysis [19]. the keyword used to search articles on scopus explorer is "vertical axis wind turbine". the number of articles found is 2411. however, limitations were given to the articles to be reviewed, which are english-language articles, journals, and published articles, so that 1801 articles that met these criteria were obtained. all data relating to the article, such as the author's name, number of citations, affiliation, keywords, abstract, and so on, are exported in csv format. the data that has been obtained from scopus is then processed using the openrefine software. the purpose of using this software is to do keyword clustering. keywords from all articles that have similar meanings are grouped so that there is no meaning bias. data visualization was performed using vosviewer 1.6.19 and tableau public 2022.2 openaccess software. these two software make data visualization more attractive in various forms. by using two software, a graph of the growth of vawt research publications, a map of the country with the number of vawt research publications, and linkages between keywords from the articles obtained can be displayed. finally, the analysis was carried out with the aim of knowing the growth of vawt research publications, opportunities for research collaboration through data on countries and authors who conducted vawt research, and ideas or challenges for future vawt research. iii. results and discussions data that has been interpreted using vosviewer 1.6.19 and tableau public 2022.2 software is analyzed as follows. figure 1. stages in bibliometric analysis • scopus • openrefine software 1. data collection • vosviewer 1.6.19 software • tableau public 2022.2 2. data visualization • vawt research growth • the growth of vawt research in various countries • challenges to future vawt research ideas 3. analysis e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 57 a. introduction vawt research growth based on data obtained from scopus, there have been 1801 articles on the topic of vawt since it was first conducted in 2021. the first research published on scopus was conducted in 1970. until 2021, the number of studies on vawt has fluctuated but tends to increase, as shown in figure 2. research published in 1970 was conducted by butler b. l., blackwell b. f. with the title “the application of laminated wooden blades to a twometer darrieus type vertical axis wind turbine” [20]. he introduced and conducted experimental testing of lauan plywood as a suitable material for darrieus propellers on a small scale. since then, until 1986, vawt research published in scopus has tended to increase. the dominant vawt research studied during this period was darrieus. during this period, most researchers focused their research on obtaining an economical darrieus design. in fact, during this period, commercial darrieus wind farms were also built in india [21] and canada [22]. however, there was a decrease in vawt research from 1987 to 2006 because it was triggered by several things, one of which was a failure in the development of a wind farm related to power transmission, which destroyed the turbine blades. turbine prototypes that had already been built were also dismantled in the early 1990s [23]. from 2007 to 2021, vawt research published on scopus continued to increase. this was triggered by efforts to reduce co2 emissions held by various countries in the world and stated in the kyoto protocol [24]. since the issuance of the kyoto protocol, in the period 2008–2012, industrialized countries must be able to reduce co2 emissions by 5 %. therefore, one of the efforts they can make to meet this target is through the development of renewable energy, one of which is wind energy. b. vawt research in various countries and opportunities for research collaboration along with the incessant efforts to reduce co2 emissions, many countries in the world are starting to participate in conducting vawt research. the number of studies on vawt by various countries in the world is shown in figure 3. the country map is made using tableau public 2022.2 software. tableau public 2022.2 software has a database for country map coordinates, when combined with the number of journal publications data in each country that has been obtained, the contours in figure 3 can be generated. in figure 3, the number of publications is also stated in the map, for example, 26 publications for indonesia, 86 publications for japan, 16 publications for australia, and so on. the country that has developed the most vawt research is china, with a total of 15.27 % scopus publications. china ranks second in the world regarding energy consumption [25]. china is determined to reduce co2 emissions by 40–45 % from 2005 to 2020 [26]. because wind energy is the most mature and economical renewable energy in china, it has great potential to be developed [27]. it is estimated that wind power installation in china is 66.9 gw in 2030 [28]. in fact, since february 2010, the chinese government has issued a policy that every coastal province must make an offshore wind power development plan under the supervision of the national energy bureau and national marine bureau [27]. then, based on the number of publications in all countries, data on the ten authors with the most citations are shown in table 1. the number of citations relates to how influential the author is on the research topic. based on the data in table 1, the two authors with the highest number of citations are figure 2. growth of vawt research published on scopus e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 58 at the same institution, namely università degli studi di firenze. bianchini, a. is an assistant professor at the department of industrial engineering, università degli studi firenze, florence, italy. he has a research interest in the field of setup and control of measurement systems, particularly concerning dynamic pressure and temperature measurement, wind tunnel external aerodynamics, and performance tests of turbomachines. meanwhile, balduzzi, f. is a research fellow at the department of industrial engineering of the university of florence. he works in the field of computational fluid dynamics (cfd) analysis of fluid machines and energy systems. the laboratories of these two authors provide renewable energy applications which are supported by adequate energy conversion machines and cfd software. however, the implementation of vawt development is not much done in italy because italy is currently hampered by several concurrent problems, the length of the authorization process being the most significant. due in large part to the environmental impact assessment (eia's) legally binding conclusion, the approval process for wind farms typically takes five and a half years [29]. so cfd simulation research on wind energy began to be started and studied by the most cited author as a preliminary study of vawt development in his country. thus, based on an analysis of the number of countries that have implemented the most vawt development, the greatest opportunities for research collaboration can be carried out in china because it has easier policies for vawt development and good technology. as for cfd research for vawt, there is an opportunity to collaborate with bianchini, a. and balduzzi, f. because both have high expertise in vawt cfd, as evidenced by the high number of citations to their articles. figure 3. country map of vawt research publications table 1. top 10 authors with the number of citations no. author number of citation affiliation scopus id 1. bianchini, a. 467 università degli studi firenze, florence, italy 50560948100 2. balduzzi, f. 397 università degli studi firenze, florence, italy 54792610900 3. blocken, b. 378 technische universiteit eindhoven, eindhoven, netherlands 55906535400 4. rezaeiha, a.. 368 ku leuvendisabled, 3000 leuven, belgium 55602401600 5. ferrara, g.. 359 università degli studi di firenzedisabled, florence, italy 36720039300 6. ferrari, i. 299 department of energy, systems, territory and construction engineering, the university of pisa, largo lucio lazzarino, pisa 56122, italy 7101737239 7. paraschivoiu, i. 269 polytechnique montréaldisabled, montreal, canada 7003702851 8. kamada, y. 246 mie universitydisabled, tsu, japan 7102943566 9. maeda, t. 239 mie universitydisabled, tsu, japan 7404540215 10. dabiri, j.o. 227 california institute of technologydisabled, pasadena, united states 6602215129 e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 59 c. vawt research trends and challenges research challenges can be analyzed through ongoing research trends. this trend can be seen from the relevance and number of keywords that are mostly used by researchers. linkage data between vawt research topic keywords from 2012 to 2021 is shown in figure 4. the data is analyzed in the last ten years to learn the latest ongoing research. the keywords linkage map was created using vosviewer 1.6.19 software. by inputting the data obtained from scopus, the map can be interpreted as figure 4 through the tools available in the software. the size of the circle indicates how many keywords are used. the bigger the circle, the more keywords are used. based on that data, the three most used keywords were vertical axis wind turbine with 799 usages, computational fluid dynamics with 346 usages, and wind turbine with 163 usages. in contrast, the least used keyword is aerodynamic loads, with seven usages. when reviewed by year, the yellow keywords are the most recent research keywords. one of the most recent research keywords is airfoil optimization. along with the development of society in the 5.0 era, artificial intelligence (ai) technology is also used in vawt research. many researchers optimize airfoil geometry using ai. for example, [30], performs airfoil geometry optimization using a genetic algorithm. he optimized the s809. as a result, the optimized s809 can increase the power coefficient (cp) by 128 %. another research regarding airfoil optimization using ai was also carried out by [31]. he optimized naca0012 using machine learning. the result is that the optimized naca0012 can increase the lift coefficient (cl) by 86.44 % and reduce the drag coefficient (cd) by 0.80 %. of all the airfoil optimization studies that have been carried out, the challenge is the optimization method used to produce better performance. regarding airfoil optimization, the performance of the optimized airfoil needs to be tested. since the existence of vawt research, the most widely used vawt performance testing method is computational fluid dynamics (cfd). as much as 51.14 % of the total scopus-published documents conducted cfd research. the popular software used by researchers to do cfd is ansys fluent. the first published vawt numerical research on scopus was conducted by [32] in 2013. he used the commercial software ansys 11.0. at that time, he had considered design parameters such as solidity, aspect ratio, pressure coefficient, and so on to achieve a power output of 1 kw, and the tests were carried out in extreme wind conditions where the maximum deflection and bending stress values were determined at maximum aerodynamics and centrifugal forces. thus, he obtained a design that has high strength and lower material consumption. since then, numerical research has become popular among researchers. cfd research is the main concern for researchers because cfd is a very useful tool for evaluating the aerodynamic performance of vawts. several cfd studies have focused on evaluating ways to improve the performance of a vawt, such as pitch angle optimization, airfoil optimization, solidity optimization, and so on. however, the biggest figure 4. keywords on the vawt research e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 60 challenge in doing cfd is finding configurations in the cfd process so that accurate results are obtained. what researchers are currently doing to improve cfd accuracy includes determining the increment angle, domain size, and turbine revolutions. research on the effect of increment angle on cfd accuracy has been carried out by [33][34][35]. these studies have examined the effect of increment angles from 0.03° to 10°. as a result, the smaller the increment angle, the more accurate the results, but it will also take a long computation time. based on research [35], cfd with an increment angle of 1° has been able to produce good accuracy and does not take longer computation time compared to an increment angle of less than 1°. research on the effect of domain size has also been carried out by [36][37][38]. these studies examine the effect of domain size on the accuracy of cfd results. the downstream domain size tested ranges from less than 10d to more than 50d, and d is turbine diameter. while the upstream domain sizes tested varied from less than 5d to 15d. research on the effect of turbine revolutions has been carried out [39]. this study examines the effect of turbine revolutions on cfd accuracy, starting from the fourth turbine rotation up to the 100th. as a result, the fifth turbine rotation can provide sufficiently accurate results without taking so long computation time. regarding the study of cfd in vawt, the biggest challenge is determining the turbulence model to use because, basically, the turbulence model for each vawt case can provide different accuracy. when using ansys fluent software, there are lots of turbulence models. therefore, there is an opportunity to conduct research on the suitability of the turbulence model for each type of vawt so that when someone wants to do a cfd vawt, they can easily find references regarding what turbulence model is suitable for their vawt type. this was conveyed because although there have been many cfd studies in the field of vawt, so far, there has not been an article that examines the tubule cfd model that is suitable for each vawt model. iv. conclusion the growth of vawt research from the beginning to 2021 has been analyzed using a bibliometric method. the results show that vawt research tends to increase from the beginning to 2021, even though it experienced a decline in the 1987–2006 range. in its growth, the country that conducted the most vawt research was china, while the authors with the highest number of citations came from italy. based on all articles conducting vawt research, cfd research dominates 51.14 % of the total. based on the analysis that has been done, the challenge for future vawt research is to determine the suitability of the turbulence model for each type of vawt or to find optimization methods to obtain airfoils with better performance. research collaborations have the potential to be carried out in china or by collaborating with the author with the highest number of citations with expertise in the cfd field. acknowledgements the authors would like to thank the indonesian universitas pendidikan indonesia for providing funding for this research. we also thank the department of mechatronics and artificial intelligence, universitas pendidikan indonesia for providing facilities for data collection. declarations author contribution all authors contributed equally as the main contributor of this paper. all authors read and approved the final paper. funding statement this research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors. competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. additional information reprints and permission: information is available at https://mev.lipi.go.id/. publisher’s note: national research and innovation agency (brin) remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. references [1] j. l. holechek, h. m. e. geli, m. n. sawalhah, and r. valdez, “a global assessment: can renewable energy replace fossil fuels by 2050?,” sustainability, vol. 14, no. 8, art. no. 8, jan. 2022. [2] “stated policies scenario (steps) – global energy and climate model – analysis,” iea. [accessed: may 24, 2023]. [3] a. qazi et al., “towards sustainable energy: a systematic review of renewable energy sources, technologies, and public opinions,” ieee access, vol. pp, pp. 1–1, may 2019. [4] asian development bank and renewable energy policy network for the 21st century, “asia and the pacific renewable energy status report,” renewable energy policy network for the 21st century, jun. 2020. [5] d. l. pristiandaru and n. a. pambudi, “wind energy in indonesia:,” indonesian journal of energy, vol. 2, no. 2, art. no. 2, aug. 2019. [6] e. n. irawan, b. p. saputro, i. a. dharma, warjono, m. putra, and m. s. muntini, “an analysis of hybrid energy design for yogyakarta international airport (yia),” j. phys.: conf. ser., vol. 1951, no. 1, p. 012032, jun. 2021. [7] b. winarno, i. basuki, and a. safi’i, “design horizontal axis wind turbine with three blades,” jeemecs (journal of electrical engineering, mechatronic and computer science), vol. 1, jul. 2018. [8] m. a. al-rawajfeh and m. r. gomaa, “comparison between horizontal and vertical axis wind turbine,” ijape, vol. 12, no. 1, p. 13, mar. 2023. [9] m. khudri johari, m. azim a jalil, and m. faizal mohd shariff, “comparison of horizontal axis wind turbine (hawt) and vertical axis wind turbine (vawt),” ijet, vol. 7, no. 4.13, p. 74, oct. 2018. [10] w.-h. chen, j.-s. wang, m. chang, j. mutuku, and a. hoang, “efficiency improvement of a vertical-axis wind turbine using a deflector optimized by taguchi approach with modified additive method,” energy conversion and management, vol. 245, p. 114609, oct. 2021. https://mev.lipi.go.id/ https://doi.org/10.3390/su14084792 https://doi.org/10.3390/su14084792 https://doi.org/10.3390/su14084792 https://www.iea.org/reports/global-energy-and-climate-model/stated-policies-scenario-steps https://www.iea.org/reports/global-energy-and-climate-model/stated-policies-scenario-steps https://doi.org/10.1109/access.2019.2906402 https://doi.org/10.1109/access.2019.2906402 https://doi.org/10.1109/access.2019.2906402 https://doi.org/10.22617/spr200173-2 https://doi.org/10.22617/spr200173-2 https://doi.org/10.22617/spr200173-2 https://doi.org/10.22617/spr200173-2 https://doi.org/10.33116/ije.v2i2.37 https://doi.org/10.33116/ije.v2i2.37 https://doi.org/10.33116/ije.v2i2.37 https://doi.org/10.1088/1742-6596/1951/1/012032 https://doi.org/10.1088/1742-6596/1951/1/012032 https://doi.org/10.1088/1742-6596/1951/1/012032 https://doi.org/10.1088/1742-6596/1951/1/012032 https://doi.org/10.26905/jeemecs.v1i1.2076 https://doi.org/10.26905/jeemecs.v1i1.2076 https://doi.org/10.26905/jeemecs.v1i1.2076 https://doi.org/10.26905/jeemecs.v1i1.2076 https://doi.org/10.11591/ijape.v12.i1.pp13-23 https://doi.org/10.11591/ijape.v12.i1.pp13-23 https://doi.org/10.11591/ijape.v12.i1.pp13-23 https://www.researchgate.net/publication/328448645_comparison_of_horizontal_axis_wind_turbine_hawt_and_vertical_axis_wind_turbine_vawt https://www.researchgate.net/publication/328448645_comparison_of_horizontal_axis_wind_turbine_hawt_and_vertical_axis_wind_turbine_vawt https://www.researchgate.net/publication/328448645_comparison_of_horizontal_axis_wind_turbine_hawt_and_vertical_axis_wind_turbine_vawt https://www.researchgate.net/publication/328448645_comparison_of_horizontal_axis_wind_turbine_hawt_and_vertical_axis_wind_turbine_vawt https://doi.org/10.1016/j.enconman.2021.114609 https://doi.org/10.1016/j.enconman.2021.114609 https://doi.org/10.1016/j.enconman.2021.114609 https://doi.org/10.1016/j.enconman.2021.114609 https://doi.org/10.1016/j.enconman.2021.114609 e.n. irawan et al. / journal of mechatronics, electrical power, and vehicular technology 14 (2023) 55-61 61 [11] s. mitchell, i. ogbonna, and k. volkov, “improvement of selfstarting capabilities of vertical axis wind turbines with new design of turbine blades,” sustainability, vol. 13, p. 3854, mar. 2021. [12] y. jiang, c. he, p. zhao, and t. sun, “investigation of blade tip shape for improving vawt performance,” journal of marine science and engineering, vol. 8, no. 3, art. no. 3, mar. 2020. [13] h. snyder, “literature review as a research methodology: an overview and guidelines,” journal of business research, vol. 104, pp. 333–339, aug. 2019. [14] n. donthu, s. kumar, d. mukherjee, n. pandey, and w. m. lim, “how to conduct a bibliometric analysis: an overview and guidelines,” journal of business research, vol. 133, apr. 2021. [15] m. r. wahid, d. zakaria, e. n. irawan, and e. joelianto, “control strategy in electric vehicle: a visualized bibliometric analysis,” international journal of sustainable transportation technology, vol. 5, no. 1, art. no. 1, apr. 2022. [16] m. öğretmenoğlu, s. göktepe, and o. atsız, “a bibliometric analysis of food studies: evidence from british food journal,” journal of multidisciplinary academic tourism, vol. 7, pp. 67– 79, nov. 2021. [17] a. rosokhata, m. minchenko, l. khomenko, and o. chygryn, “renewable energy: a bibliometric analysis,” e3s web of conferences, vol. 250, p. 03002, jan. 2021. [18] a. mathankar, “bibliometrics: an overview,” international journal of library and information science, vol. 7, jun. 2018. [19] j. baas, m. schotten, a. plume, g. côté, and r. karimi, “scopus as a curated, high-quality bibliometric data source for academic research in quantitative science studies,” quantitative science studies, vol. 1, pp. 1–10, jan. 2020. [20] m. islam, a. fartaj, and r. carriveau, “analysis of the design parameters related to a fixed-pitch straight-bladed vertical axis wind turbine,” wind engineering, vol. 32, no. 5, pp. 491– 507, oct. 2008. [21] p. n. shankar, “development of vertical axis wind turbines,” proc. indian acad. sci. (engg. sci.), vol. 2, no. 1, pp. 49–66, mar. 1979. [22] j. d. katzberg, w. d. stewart, and h. berwald, “a progress report on an isolated darrieus wind electrical system,” in [proceedings] wescanex ’91, pp. 164–170, may 1991. [23] e. möllerström, p. gipe, j. beurskens, and f. ottermo, “a historical review of vertical axis wind turbines rated 100 kw and above,” renewable and sustainable energy reviews, vol. 105, pp. 1–13, may 2019. [24] e. h. nyekwere, “commercializing international environmental protection: a review of the kyoto protocol to the united nations framework convention on climate change and its market-based mechanisms,” international affairs and global strategy, vol. 86, no. 0, p. 21, july 2020. [25] t. yin, “the diversity of energy consumption structure, energy efficiency and carbon emissions: evidence from shaanxi, china,” plos one, vol. 18, p. e0285738, may 2023. [26] “wen jiabao: china’s carbon intensity reduction target has been demonstrated for a long time by eight departments,” [accessed: nov. 24, 2022]. [27] y. wang et al., “where is the most feasible, economical, and green wind energy? evidence from high-resolution potential mapping in china,” journal of cleaner production, vol. 376, p. 134287, sep. 2022. [28] x. deng et al., “offshore wind power in china: a potential solution to electricity transformation and carbon neutrality,” fundamental research, nov. 2022. [29] l. sensi et al., “re-powering italian wind farms: a feasibility study from theory to practice,” journal of physics: conference series, vol. 2385, p. 012107, dec. 2022. [30] y. kim, a. al-abadi, and a. delgado, “strategic blade shape optimization for aerodynamic performance improvement of wind turbines,” in oil and gas applications; supercritical co2 power cycles; wind energy, seoul, south korea: american society of mechanical engineers, vol. 9, jun. 2016, p. v009t46a009. [31] x. song, l. wang, and x. luo, “airfoil optimization using a machine learning-based optimization algorithm,” j. phys.: conf. ser., vol. 2217, no. 1, p. 012009, apr. 2022. [32] m. s. hameed and s. k. afaq, “design and analysis of a straight bladed vertical axis wind turbine blade using analytical and numerical techniques,” ocean engineering, vol. 57, pp. 248– 255, jan. 2013. [33] e. n. irawan, s. sitompul, k.-i. yamashita, and g. fujita, “the effect of rotor radius ratio on the performance of hybrid vertical axis wind turbine savonius-darrieus nrel s809,” journal of energy and power technology, vol. 5, no. 1, art. no. 1, jan. 2023. [34] m. s. siddiqui, m. h. khalid, a. w. badar, s. muhammad, and t. asim, “parametric analysis using cfd to study the impact of geometric and numerical modeling on the performance of a small scale horizontal axis wind turbine,” energies, vol. 15, p. 505, jan. 2022. [35] d. satrio, i. k. utama, and m. mukhtasor, “the influence of time step setting on the cfd simulation result of vertical axis tidal current turbine,” journal of mechanical engineering and sciences, vol. 12, pp. 3399–3409, mar. 2018. [36] g. santo, peeters, w. van paepegem, and j. degroote, “fluid– structure interaction simulations of a wind gust impacting on the blades of a large horizontal axis wind turbine,” energies, vol. 13, p. 509, jan. 2020. [37] q. mo, h. guan, s. he, y. liu, and r. guo, “guidelines for the computational domain size on an urban-scale vawt,” journal of physics: conference series, vol. 1820, p. 012177, mar. 2021. [38] y. abu-zidan, p. mendis, and t. gunawardena, “optimising the computational domain size in cfd simulations of tall buildings,” heliyon, vol. 7, p. e06723, apr. 2021. [39] a. rezaeiha, h. montazeri, and b. blocken, “towards accurate cfd simulations of vertical axis wind turbines at different tip speed ratios and solidities: guidelines for azimuthal increment, domain size and convergence,” energy conversion and management, vol. 156, pp. 301–316, jan. 2018. https://doi.org/10.3390/su13073854 https://doi.org/10.3390/su13073854 https://doi.org/10.3390/su13073854 https://doi.org/10.3390/su13073854 https://doi.org/10.3390/jmse8030225 https://doi.org/10.3390/jmse8030225 https://doi.org/10.3390/jmse8030225 https://doi.org/10.1016/j.jbusres.2019.07.039 https://doi.org/10.1016/j.jbusres.2019.07.039 https://doi.org/10.1016/j.jbusres.2019.07.039 https://doi.org/10.1016/j.jbusres.2021.04.070 https://doi.org/10.1016/j.jbusres.2021.04.070 https://doi.org/10.1016/j.jbusres.2021.04.070 https://doi.org/10.31427/ijstt.2022.5.1.4 https://doi.org/10.31427/ijstt.2022.5.1.4 https://doi.org/10.31427/ijstt.2022.5.1.4 https://doi.org/10.31427/ijstt.2022.5.1.4 https://doi.org/10.31822/jomat.2022-7-1-67 https://doi.org/10.31822/jomat.2022-7-1-67 https://doi.org/10.31822/jomat.2022-7-1-67 https://doi.org/10.31822/jomat.2022-7-1-67 https://doi.org/10.1051/e3sconf/202125003002 https://doi.org/10.1051/e3sconf/202125003002 https://doi.org/10.1051/e3sconf/202125003002 https://doi.org/10.34218/ijlis.7.3.2018.002 https://doi.org/10.34218/ijlis.7.3.2018.002 https://doi.org/10.1162/qss_a_00019 https://doi.org/10.1162/qss_a_00019 https://doi.org/10.1162/qss_a_00019 https://doi.org/10.1162/qss_a_00019 https://doi.org/10.1260/030952408786411903 https://doi.org/10.1260/030952408786411903 https://doi.org/10.1260/030952408786411903 https://doi.org/10.1260/030952408786411903 https://doi.org/10.1007/bf02899755 https://doi.org/10.1007/bf02899755 https://doi.org/10.1007/bf02899755 https://doi.org/10.1109/wescan.1991.160541 https://doi.org/10.1109/wescan.1991.160541 https://doi.org/10.1109/wescan.1991.160541 https://doi.org/10.1016/j.rser.2018.12.022 https://doi.org/10.1016/j.rser.2018.12.022 https://doi.org/10.1016/j.rser.2018.12.022 https://doi.org/10.1016/j.rser.2018.12.022 https://doi.org/10.7176/iags/86-03 https://doi.org/10.7176/iags/86-03 https://doi.org/10.7176/iags/86-03 https://doi.org/10.7176/iags/86-03 https://doi.org/10.7176/iags/86-03 https://doi.org/10.1371/journal.pone.0285738 https://doi.org/10.1371/journal.pone.0285738 https://doi.org/10.1371/journal.pone.0285738 http://www.chinadaily.com.cn/hqzx/2009-12/17/content_9190425.htm http://www.chinadaily.com.cn/hqzx/2009-12/17/content_9190425.htm http://www.chinadaily.com.cn/hqzx/2009-12/17/content_9190425.htm https://doi.org/10.1016/j.jclepro.2022.134287 https://doi.org/10.1016/j.jclepro.2022.134287 https://doi.org/10.1016/j.jclepro.2022.134287 https://doi.org/10.1016/j.jclepro.2022.134287 https://doi.org/10.1016/j.fmre.2022.11.008 https://doi.org/10.1016/j.fmre.2022.11.008 https://doi.org/10.1016/j.fmre.2022.11.008 https://doi.org/10.1088/1742-6596/2385/1/012107 https://doi.org/10.1088/1742-6596/2385/1/012107 https://doi.org/10.1088/1742-6596/2385/1/012107 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1115/gt2016-56836 https://doi.org/10.1088/1742-6596/2217/1/012009 https://doi.org/10.1088/1742-6596/2217/1/012009 https://doi.org/10.1088/1742-6596/2217/1/012009 https://doi.org/10.1016/j.oceaneng.2012.09.007 https://doi.org/10.1016/j.oceaneng.2012.09.007 https://doi.org/10.1016/j.oceaneng.2012.09.007 https://doi.org/10.1016/j.oceaneng.2012.09.007 https://doi.org/10.21926/jept.2301001 https://doi.org/10.21926/jept.2301001 https://doi.org/10.21926/jept.2301001 https://doi.org/10.21926/jept.2301001 https://doi.org/10.21926/jept.2301001 https://doi.org/10.3390/en15020505 https://doi.org/10.3390/en15020505 https://doi.org/10.3390/en15020505 https://doi.org/10.3390/en15020505 https://doi.org/10.3390/en15020505 https://doi.org/10.15282/jmes.12.1.2018.9.0303 https://doi.org/10.15282/jmes.12.1.2018.9.0303 https://doi.org/10.15282/jmes.12.1.2018.9.0303 https://doi.org/10.15282/jmes.12.1.2018.9.0303 https://doi.org/10.3390/en13030509 https://doi.org/10.3390/en13030509 https://doi.org/10.3390/en13030509 https://doi.org/10.3390/en13030509 https://doi.org/10.1088/1742-6596/1820/1/012177 https://doi.org/10.1088/1742-6596/1820/1/012177 https://doi.org/10.1088/1742-6596/1820/1/012177 https://doi.org/10.1016/j.heliyon.2021.e06723 https://doi.org/10.1016/j.heliyon.2021.e06723 https://doi.org/10.1016/j.heliyon.2021.e06723 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 https://doi.org/10.1016/j.enconman.2017.11.026 introduction ii. materials and methods iii. results and discussions a. introduction vawt research growth b. vawt research in various countries and opportunities for research collaboration c. vawt research trends and challenges iv. conclusion acknowledgements declarations author contribution funding statement competing interest additional information references