In order to improve the braking performance of electric vehicles, a novel brake-by-wire actuator based on an electro-magnetic linear motor was designed and manufactured. For the purpose of braking force regulation accuracy and high robust performance, the state observer and the anti-disturbance controller were designed in this paper after describing the actuator structure, braking principle, and mathematical model. The simulation and experimental results showed that the brake actuator responded rapidly, since its response time was only 15 ms. Compared to traditional PID (Proportion Integration Differentiation) methods, the controller proposed in this paper is able to regulate the braking force more precisely and has better anti-disturbance performance, thus the braking process can be accurately controlled according to the driver’s demand. The vehicle simulation results showed that the braking distance and braking time were shortened by 12.19% and 15.54%, respectively compared with those of the conventional anti-lock brake system (ABS) in the same braking conditions.

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The brake-by-wire actuator was considered to be the next generation of vehicle brake, which uses cables to transmit signals and energy, and uses electric motor instead of hydraulic element or pneumatic element. This paper designs a new type of brake-by-wire actuator based on the special linear motor. First, the structure, composition and working principle of the linear motor are explained. Secondly, the caliper structure and amplification mechanism of the actuator are designed. Thirdly, the controller and control strategy based on dSPACE platform are introduced in detail. Finally, the electromechanical parameters of actuator were identified, and the experiment of the linear motor and brake-by-wire actuator were completed. The experiment results show that the new actuator has the advantages of fast braking response, low control difficulty and high control accuracy, etc. In conclusion, this paper provides a new design scheme for the brake-by-wire actuator, and has the potential to further research and replace the traditional hydraulic braking system.

In order to effectively improve the vehicle safety, this paper proposed an electronic brake force distribution scheme and an anti-lock brake scheme for passenger car based on a novel brake-by-wire system. The brake-by-wire system was introduced at first, then the electronic brake force distribution scheme and anti-lock brake scheme are designed after analyzing of brake system and vehicle model. At last, the experiment is accomplished to prove the feasibility of the novel brake-by-wire actuator, and the co-simulations of vehicle based on Matlab/Simulink and AMESim are accomplished for typical braking process to prove the superiority of proposed brake-by-wire system and brake scheme. On the one hand, the experiment and simulation results show that the proposed electronic brake force distribution scheme is able to distribute the braking force according to braking intensity and conditions. So the β curve can as close as possible to the I curve. On the other hand, the anti-lock brake scheme is able to accurately regulate the wheel slip rate and adapt to different brake intensity. So the anti-lock brake scheme processes strong robust performance.KEY WORDS: brake-by-wire, linear motor, electric brake force distribution, anti-lock brake, fuzzy control (B1)