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CHEMICAL ENGINEERINGTRANSACTIONS 
 

VOL. 66, 2018 

A publication of 

 

The Italian Association 
of Chemical Engineering 
Online at www.aidic.it/cet 

Guest Editors:Songying Zhao, Yougang Sun, Ye Zhou 
Copyright © 2018, AIDIC ServiziS.r.l. 

ISBN978-88-95608-63-1; ISSN 2283-9216 

Study on Vehicle Electronic Stability Program Control 

Algorithm under Electronic Mechanical Braking 

Zhen Wang, Zhehao Hong, Yumeng Wang, Jinjun Zheng* 

College of Automobile Engineering, Jilin University, Changchun 130012, China 

wangzhen@jlu.edu.cn 

This paper aims to understand the vehicle electronic stability program control algorithm under electronic 

mechanical braking. Methods: ADAMS/Flex is used for research. The simulation results are analyzed, and the 

process and model of vehicle braking are analyzed. The results show that the design is effective. Through the 

analysis of the process and model, it is proved that the motor speed is up to 1125deg/s in a short time. It is 

basically consistent with the rated motor speed 190r/min of the motor, which shows the validity and 

correctness of this design. 

1. Introduction 

Automobiles are one of the most important tools for people to travel in modern society. At present, most 

automobiles are driven by the electronic mechanical brake system. This system is mainly used as a brake 

actuator, and its main core is the motor drive component. However, the emergence of electro mechanical 

braking system has replaced the traditional hydraulic or pneumatic braking mode, which has effectively 

improved the shortcomings of traditional vehicle braking methods. In order to better understand the electronic 

mechanical braking system, on the basis of previous theoretical research, the control algorithm of the 

electronic stability program under electronic mechanical braking is studied. 

The research ideas of this paper are as follows: First of all, the simulation analysis of the braking performance 

of the EMB rigid flexible coupling system is carried out mainly by the combined simulation technology of 

ADAMS and ANSYS, and the stability of the braking of the EMB system is studied emphatically, and the test 

bench is built to verify and analyze the EMB system. In this regard, it has a guiding significance for the 

development of the EMB system. Secondly, according to the analysis and comparison of the representative 

EMB implementation scheme, the optimized EMB actuator structure is selected for a certain sample model, so 

as to realize the type selection design of the concrete structure, and complete the dimension modeling and 

assembly according to the specific parameters. In addition, in order to verify the effectiveness of the design in 

this paper, a rigid flexible coupling dynamic simulation model of the EMB system is established, and the effect 

of the brake disc and brake block deformation on the braking performance is considered, and the equivalent 

model of the flywheel is established. The moment of rotational inertia of the whole vehicle is equivalent to a 

single wheel, and the dynamic model of a single brake is simulated. 

2. Literature review 

With the rapid development of the automobile industry and the continuous improvement of the road traffic 

facilities, the automobile has gradually become a step tool for people. People are enjoying the comfort and 

convenience of the car and put forward higher requirements for the safety performance of the car. Research 

by the Zang and others showed that, according to the German Insurance Association and the automotive 

safety association, the analysis of the causes of serious traffic accidents showed that 60% of the death traffic 

accidents were caused by the side crash, and 30%-40% was caused by overspeed, sudden change or 

operation (Zang et al., 2017). Automobile safety, energy saving and environmental protection are the main 

direction of the development of the automobile industry. With the development of the society and the progress 

of automobile technology, the traffic and transportation industry present the trend of high speed, non-

                                

 
 

 

 
   

                                                  
DOI: 10.3303/CET1866124 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Please cite this article as: Wang Z., Hong Z., Wang Y., Zheng J., 2018, Study on vehicle electronic stability program control algorithm under 
electronic mechanical braking, Chemical Engineering Transactions, 66, 739-744  DOI:10.3303/CET1866124   

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professional and dense traffic, and how to improve the safety is one of the important topics of modern 

automobile research. The safety of the car includes active safety and passive safety. Active safety refers to 

how to minimize or avoid the occurrence of traffic accidents through the design of the vehicle. Passive safety 

means that the vehicle is designed to minimize the damage to the crew in the event of an accident. In the 

study, Gong and others pointed out that the brake system of the car is the key to determine the vehicle's 

active safety. How to design the brake system and make it have a good braking performance is always an 

important issue for the vehicle researchers. In recent years, due to the progress of vehicle technology and the 

improvement of vehicle speed, this importance is becoming more and more obvious (Gong et al., 2015). 

At present, the research on vehicle braking mainly focuses on braking control, including the theory and 

method of braking control, and the adoption of new control technology (Zhai et al., 2016). The anti-lock 

braking system (ABS) adjusts the brake pressure according to the attachment characteristics of the tire and 

ground at different slip rates to prevent the wheel from locking in the car. By making full use of the ground 

adhesion coefficient, the high ground braking force can be obtained, the braking distance of the car is 

shortened, the direction stability of the automobile braking is improved and the tire wear is reduced. This 

technology has played an important role in improving vehicle safety and reducing accident losses. It is one of 

the most important active safety technologies in the automotive industry. 

The automobile anti-skid control system (Anti Slip Regulation) is called ASR for short, also known as Traction 

Control System (TCS) (Ko et al., 2014). It is an electronic control system applied to wheel skid resistance 

following ABS. Its function is to control the slip ratio within a certain range when the vehicle accelerates, thus 

to prevent the driving wheel from sliding rapidly. Its function is to increase traction; the two is to maintain the 

stability of the vehicle. Driving on a slippery road, the driving wheel is easy to skid without ASR's car 

acceleration; if the rear driven-vehicle is easy to tail, it is easy to get out of control in the direction of the front 

drive. When ASR is used, it will not or can alleviate this phenomenon when the car accelerates. When turning, 

if the wheel skidding occurs, the whole vehicle will shift to one side. When ASR is used, the vehicle will follow 

the correct route. Electronic Stability Program controls the system (Moon et al., 2014) for short ESP. The ESP 

system, which appeared in the middle of the 90s, is another major leap in automotive active safety following 

the anti-lock braking system of the automobile and the anti-skid control system of the automobile (Yim, 2015). 

The ESP system is used to control the dynamic performance of vehicles and wheels under the critical 

condition of reaching the adhesion limit between the tire and the road surface. ESP will greatly improve the 

stability of the wheels and vehicles when the vehicle is in full braking or partial braking, sliding, driving, engine 

drag and braking, shift transition and transition from drive to brake. By controlling and distributing the 

longitudinal and lateral forces of the tire, the vehicle will travel as much as possible along the driver's desired 

path, reduce the risk of vehicle slip, improve the handling and stability of the vehicle, and establish a 

predictable vehicle behaviour system adapted to the experience of the driver. 

Gao and others think that with the continuous development of vehicle chassis dynamics control, integrated 

control is the direction of future development (Gao et al., 2014), Brake by wire system BBW (brake-by-wire) 

arises at the historic moment. The wire brake system is different from the traditional brake system. It cancels 

the mechanical connection between the brake pedal and the brake actuator, and completely gets rid of the 

limitations of the traditional brake system. At present, the BBW has been applied to medium and high-class 

cars. The concept of wire control technology originated from aviation field and was first applied to aircraft 

manufacturing. People call it "wire-controlled flight control technology". Line control flight control technology 

has been successfully run on military and commercial aircraft for more than 20 years after its rigorous test of 

security, reliability and maneuverability. At present, it is also applied to high-tech land warfare equipment. 

Aviation and military applications have proved that wire control technology (X-by-Wire) is reliable and efficient. 

With the further development and wide application of electronic technology, this concept has been introduced 

into the field of vehicle manufacturing, and the application of line control steering, linear control throttle and 

line control technology on vehicles has emerged. With its superior performance, wire control technology is 

becoming more and more popular among the world's major auto manufacturers. This technique can 

emancipate the driver from a variety of tedious operations in the driving car and assist the driver in handling 

emergencies in a critical time, thus improving the handling stability and safety of the vehicle. This technology 

is listed as one of the ten new technologies of automobile in 2000. The technology of line control will bring a 

revolution to the automobile industry (Fang, 2017). It will become the core of the future development of 

intelligent vehicle technology. The line controlled BBW system, which is formed by the line control technology 

and the automobile brake system, has gradually replaced the traditional hydraulic and mechanical systems as 

the trend of the development of braking technology. A linear brake system is a multi-functional braking system, 

such as the brake antilock system ABS (Antilock Braking System), the electronic braking force distribution 

EBD (Electronic Brakeforce Distribution), the vehicle stability control ESP (Electronic Stability Program) or the 

ESC (Electronic Stability Control). The traction control system TCS (Traction Control System) and other 

existing braking system functions, and through the vehicle wired network, each system is organically 

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integrated into a complete functional system. The emergence of the brake by wire system has brought great 

changes to the design of vehicle braking characteristics, providing the conditions for future intelligent vehicle 

control. 

To sum up, the above research work has done a deep research on vehicle braking control, but there are few 

researches on integrated control. Therefore, based on the above research status, this paper mainly studies 

the electronic stability program control algorithm under electronic mechanical braking. The characteristics of 

the high-speed switch valve of the important hydraulic components in the hydraulic regulator of the EHB 

system are discussed in depth. The hydraulic regulator of the electronic hydraulic brake system EHB 

(Electronic Hydraulic Brake System) is modelled and the dynamic characteristics of the hydraulic system are 

simulated and analysed by AMESim. To prove the validity and rationality of the vehicle stability control 

algorithm, the vehicle stability control algorithm is simulated by using open loop control and closed loop control 

respectively by using AMESim, CarSim and matlab/Simulink simulation environment. 

3. Methods 

ADAMS/Flex is used to input the brake disc and the modal neutral files of the brake block flexible body 

generated by ANSYS into ADAMSF/View, and move it to the appropriate position, as shown in Figure 1. 

 

Figure 1: Import of brake disc and brake block flexible body in Adams 

It is necessary to verify whether the brake disc and brake block flexible body are distorted after being 

introduced into A. The correctness of the model is verified by obtaining the mass, the moment of inertia and 

the center of mass of the brake disc and the flexible body of the brake block flexible body. 

This paper is a dimensional model of the actuating mechanism of the electronic brake system for vehicles built 

in the CATIA environment. By using the simdesign interface module, its 3D model can be imported into the 

ADAMS to complete the assembly between the rigid body and the flexible body. The EMB rigid flexible 

coupling system after assembly is shown as shown in Figure 2 below. 

 

Figure 2: EMB rigid flexible coupling system 

The EMB system executor is a rigid flexible coupling system composed of several rigid bodies and flexible 

bodies. In order to simulate the real motion situation of the EMB system during the braking process, the 

motion relationship between components should be abstracted as the corresponding kinematic pair in 

ADAMS. Through these identified kinematic pairs, the independent components of the EMB system are linked 

together to form an integrated system. 

When the driver's brake signal is received by the EMB system, the DC torque motor decelerated by rotor 

output torque through planetary gear reducer, and the rotational motion of the low speed and high torque is 

converted into the straight motion of the nut, and the nut pushes one side of the brake block to press the brake 

disc. The counteraction of reaction of the lead screw acts as a driving force to drive the subject into the 

opposite direction. 

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In ADAMS/View, loads mainly include the external load, the internal load and the special load. The external 

load is mainly the force applied to the system, the moment and the gravity. The internal load is mainly the 

flexible connection between the parts, such as the spring, the buffer, etc. The special load refers to the contact 

force and the friction force on constraints. This paper focuses on the special loads such as EMB system 

applied gear to W, Contact force between the brake disc and brake module. 

When two construction surfaces are exposed, a special contact force is produced in the position of contact. 

The contact force mainly includes intermittent contact and continuous contact of two kinds. In the case of 

continuous contact, the system defines contact as a form of nonlinear spring, the resistance of material is 

taken as the energy loss, and the elastic modulus is regarded as spring stiffness. In ADAMS, there are two 

kinds of methods of calculating the contact force, namely, the compensation method and the impact function 

method. The compensation method needs to determine the penalty coefficient and the compensation 

coefficient. The penalty coefficient indicates the depth of the two components that contact each other. The 

greater the penalty coefficient is, the greater the contact stiffness is. The less the depth of a component 

entering another component is, the greater the penalty coefficient is, and the computation result may not 

converge. If penalty coefficient is too small, it cannot reflect the real contact between two components of F. 

The compensation coefficient represents the loss of energy between two components. When the contact force 

is defined by the impact function method, the Impact function is used to calculate the contact force. The 

unilateral collision force is approximately calculated by the nonlinear spring resistance method. W hen two 

components enter into each other, they will produce elasticity, and the relative speed between the two 

components will produce resistance. 

In this paper, the contact type of brake disc and brake block is set as flexible body to flexible body.In addition 

to axial contact force and tangential friction in process of flexible body contact between brake disc and brake 

block, tangential friction realizes the braking effect by producing braking torque. 

The contact parameters are defined as follows, 

Spring force stiffness factor K=100000 

Nonlinear force field index e=3 

Maximum damping coefficient c=1 

Penetrationdistance d=F0.001. 

The rigid-flexible coupling model of EMB system actuator with load and constraint is shown in figure 24 as 

below. 

 

Figure 3: the rigid flexible coupling model of EMB system actuator is applied to load and constraint 

3.1 The calculation on equivalent rotational inertia of the whole vehicle 

In this paper, as the whole vehicle model has not been built, if it needs to act real vehicle braking process in 

the simulation analysis, the rotational inertia of the rotating parts and motion translational inertia of the whole 

vehicle should be equalized as inertia flywheel applied to brake disc. As the inertia flywheel and brake disc are 

fixed connected and coincident, with the changes upon rotational inertia of inertia flywheel, the simulation of 

actual driving conditions under different load could be realized. 

3.2 Results and analysis 

After the establishment of EMB system rigid flexible affinity model in the ADAMS, the braking performance 

such as braking force, brake response time, braking distance require simulation analysis, and verification on 

the rationality of the selection design on simulation should be carried out through comparing the theoretical 

calculation results and national standard brake laws and regulations. In addition, with the test bench setup for 

EMB system actuator braking performance, the braking force produced by locked-rotor state of torque motor 

and parameter of elimination on brake clearance time of actuators are tested to suggest the rationality of the 

scheme selection and the selected design results through the simulation analysis and experimental validation. 

After point C, the car begins to generate braking force and decelerate. From point C to point C is the time 

required for braking force growth of disc brake EMB system, namely the braking action time. And from point e 

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to point f is the braking duration of T3 of EMB system brake, the braking force and deceleration speed remain 

unchanged. And then from point f to point g is the braking force eliminating period. The braking response 

process of automobile is shown in figure 4. 

 

Figure4: Vehicle braking response process 

The whole braking process of EMB system includes four processes, namely the reaction time of the driver 

receiving brake signal, the action time of the brake, the braking force continuity and brake elimination. Braking 

distance refers to the vehicle movement distance start from driver beginning to contact with the brake pedal to 

the car stop, which determined by the main factors of the action time of the brake and maximum braking 

deceleration. 

The electromechanical actuator is one of the most important parts of the which is distinguished from the 

hydraulic brake. The dynamic response of the EMB braking system is faster than that of the hydraulic braking 

system because the motor could directly drive the gear reducer in electromechanical braking system. In the 

rigid flexible affinity model in ADAMS, in order to be able to accurately predict the braking efficiency of EMB 

system, the motor rotor in dynamic model requires the initial conditions of simulation. The motor approximately 

works under no-load speed at the eliminating brake clearance stage, and as the brake block contact with the 

brake disc, motor speed quickly reduces to completely blocked, and to regulate output torque through 

changing armature voltage. The DC motor mathematical model is set up to drive the motor before the start of 

the simulation conveniently. 

In this paper, the driving motor of the EMB system is the permanent magnet DC torque motor, and its 

equivalent circuit diagram is shown in figure 5. 

 

Figure 5: Equivalent circuit of rare earth permanent magnet DC torque motor 

When actuators in EMB system are in the eliminating brake clearance stage, the brake clearance of disc 

brake is generally between 0.1 and 0.3 imnPq as reference, thus in this paper the brake clearance time on 

both sides of brake disc is set of 0.1 mm, with the motor starting voltage of 24 v and the simulation time of 0.1 

s. FIG. 6 shows the simulation results of eliminating brake clearance time in EMB system. 

 

Figure 6: Clearance time 

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As you can see in the above figure, the torque motor start running at the approximate no-load speed, and the 

inside brake block near the screw nut contacts with brake disc at 0.044 s, and then the inside brake block is 

resistant, thus axial reaction force of screw rod act on the misprinted with bearing thrust, which lead to the 

italic displacement along sliding pin to drive the lateral brake block move to brake disc, finally the clamping of 

brake disc is completed at the time of 0.078 s that the brake housing drives the lateral brake block contact with 

the brake disc. The motor reaches the no-load speed within a very short time after starting, so the clearance 

time of the lateral brake clearance is shorter than that of the inner one. After 0.085s, the brake clearance is 

completely eliminated, and the inner and outer brake block act on the brake disc simultaneously to generate 

the brake clamping force, which meets the design requirements of automobile braking clearance elimination. 

The motor speed reaches 1125deg/s in a short time, which is basically consistent with the rated no-load speed 

of 190r/min of the motor. 

4. Conclusion 

In order to understanding for automotive electronic mechanical brake system, ADAMS/Flex is applied to input 

the neutral file in brake disc and brake block in flexible body modal generated by ANSYS into ADAMSF/View, 

and then move it to the right location and expound the adjustment results. Later it will also import and 

assemble the rigid body in ADAMS, then calculation of the restrictions of EMB coupling system with rigid and 

flexible, applied load of EMB coupling system, the definition of contact parameters of brake disc and brake 

block, the equivalent rotational inertia of the vehicle could be carried out. Finally in order to demonstrate the 

validity of this study, that the process and model of simulation and the analysis of the process and model 

proves that the motor rotation speed could reach 1125 deg/s in a short period of time, which is basically 

consistent with the rated no-load speed of 190r/min of the motor, thus it illustrates the validity and correctness 

of the design in this paper. 

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