Research on Compensation Redundancy Control for Basic Force Boosting Failure of Electro-Booster Brake System 2020-01-0216

As a new brake-by-wire solution, the electro-booster (Ebooster) brake system can work with the electronic stability program (ESP) equipped in the real vehicle to realize various excellent functions such as basic force boosting (BFB), active braking and energy recovery, which is promoting the development of smart vehicles. Among them, the BFB is the function of Ebooster's servo force to assist the driver's brake pedal force establishing high-intensity braking pressure. After the BFB function failure of the Ebooster, it was not possible to provide sufficient brake pressure for the driver's normal braking, and eventually led to traffic accidents. In this paper, a compensation redundancy control strategy based on ESP is proposed for the BFB failure of the self-designed Ebooster. Firstly, introduced the working principle of Ebooster and ESP, and a suitable pressure-building circuit was selected for the dual brake actuator system; Secondly, after the BFB failure of Ebooster, the rule-based strategy of braking awareness recognition was designed. Thirdly, a layered closed-loop compensation control strategy is designed based on the ESP to restore the pressure building capacity of the hydraulic system. Finally, based on dSPACE products, a hardware-in-the-loop (HiL) experimental bench with dual brake actuators including ESP and Ebooster was built for algorithm verification. The HiL experiment results show that after the BFB failure of Ebooster, the designed compensation redundancy control algorithm can restore the Pressure-Volume (P-V) characteristics of the brake system just like Ebooster's conventional BFB mode, and improve vehicle driving safety.