A design method for booster motor of brake-by-wire system based on intelligent electric vehicle

The brake-by-wire(BBW)system is an essential part of the intelligent electric vehicle,which is determination of the braking safety and recovery efficiency.To design a safe and efficient booster motor,the design of booster motor for BBW system is discussed in this paper.Through comparative analysis,experimental simulation and assessment argument,the scheme of designing a booster motor for brake-by-wire system is completely described.First,the mainstream structure of the BBW system and the main challenges it faces in the assisted motor are discussed.Second,comparing the motors of different types and structures,the motor body and control system scheme suitable for the characteristics of the booster motor system are determined.Then,through the simulation analysis of the ansoft and matlab,the optimization scheme of the motor and performance improvement are proposed.Further,through the actual design of a set of the booster motor system,the safe and efficient motor designing are verified,and the problems involving functional safety are discussed.Finally,focus on the problem while simulation and experiment,some important countermeasures to improve current technology and prospect of in-depth study are pointed out.

Blended Regenerative Anti-Lock Braking System and Electronic Wedge Brake Coordinate Control Ensuring Maximal Energy Recovery and Stability of All-Wheel-Motor-Drive Electric Vehicles

ABS is an active safety system which showed a valuable contribution to vehicle safety and stability since it was first introduced. Recently, EVs with in-wheel-motors have drawn increasing attention owing to their greatest advantages. Wheels torques are precisely and swiftly controlled thanks to electric motors and their advanced driving techniques. In this paper, a regenerative-ABS control RABS is proposed for all-in-wheel-motors-drive EVs. The RABS is realized as a pure electronic braking system called brake-by-wire. A coordination strategy is suggested to control RABS compromising three layers. First, wheels slip control takes place, and braking torque is calculated in the higher layer. In the coordinate interlayer, torque is allocated between actuators ensuring maximal energy recovery and vehicle stability. While in the lower layer, actuator control is performed. The RABS effectiveness is validated on a 3-DOF EVSimulink model through two straight-line braking manoeuvres with low and high initial speeds of 50 km/h and 150 km/h, respectively. Both regular and emergency braking manoeuvres are considered with ABS enabled and disabled for comparison. Simulation results showed the high performance of the proposed RABS control in terms of vehicle stability, brake response, stopping distance, and battery re-charging.

Pressure-tracking control of a novel electro-hydraulic braking system considering friction compensation

This work presents an integrated pressure-tracking controller for a novel electro-hydraulic brake(EHB) system considering friction and hydraulic disturbances. To this end, a mathematical model of an EHB system, consisting of actuator and hydraulic sub-systems, is derived for describing the fundamental dynamics of the system and designing the controller. Due to sensor inaccuracy and measurement noise, a Kalman filter is constructed to estimate push rod stroke for generating desired master cylinder pressure. To improve pressure-tracking accuracy, a linear friction model is generated by linearizing the nonlinear Tustin friction model, and the unmodeled friction disturbances are assumed unknown but bounded. A sliding mode controller is designed for compensating friction disturbances, and the stability of the controller is investigated using the Lyapunov method. The performance of the proposed integrated controller is evaluated with a hardware-in-the-loop(HIL) test platform equipped with the EHB prototype. The test results demonstrate that the EHB system with the proposed integrated controller not only achieves good pressure-tracking performance, but also maintains robustness to friction disturbances.

A New Type of Automotive Braking Actuator for Decentralized Electro-hydraulic Braking System

This paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system( DEHB) to replace the traditional automobile braking system. The actuator of this system is driven by an electrical motor instead of the conventional vacuum booster to make the brake pressure be linearity controlled quickly. Therefore,the system has the advantages of quick response speed,good control performance and simple structure. Firstly,an overview of the actuator and the whole DEHB system is shown. Secondly,the possibility of this new kind of actuator working for the system is ensured based on some braking theories. Thirdly,the appropriate dynamic simulations are done to get some results to show the relations of different parameters and the effect of braking. Eventually,the proper parameters are determined to build a test bench which shows that DEHB system can achieve the maximum pressure of 13 MPa within 100 ms after parametric optimization,and meanwhile,the actuator is able to reduce pressure quickly after maintaining high pressure. All of the bench test results can meet with the design requirements and real demand of vehicle and this actuator may improve vehicle braking effect in the future. Besides,this actuator can be widely applied to the regenerative braking system because of its linear braking performance.