A Control and Fault-Tolerant Strategy Based on Electromechanical Brake System

With the development of automobile electrification and intelligent technology, vehicles have higher and higher requirements for braking systems. On the one hand, they are required to have active braking functions and be easy to integrate with other control systems in the chassis domain; on the other hand, the system is required to minimize oil pollution and be able to recover as much braking energy as possible in cooperation with the upper-level control strategy under the premise of ensuring pedal force to increase the cruising range of electric vehicles. The composite braking system based on electromechanical brake (EMB) is a wire-controlled decoupled composite braking system that can not only meet the needs of brake pedal feel, but also achieve continuous and precise control of composite braking force, and can effectively take into account the braking energy recovery rate, braking safety and braking comfort. In addition, the current EMB technology is still immature and has a high failure rate, so it is very meaningful to study the fault-tolerant control of EMB. This paper mainly studies the control strategy of the electromechanical brake system. Firstly, the EMB actuator is selected, designed and calculated, and the system is modeled. Secondly, the EMB multi-stage closed-loop control strategy is designed based on the permanent magnet synchronous motor vector control method. Finally, for the two working conditions of EMB single wheel failure and two-wheel failure on the opposite side, a rule-based braking force redistribution strategy is designed. The effectiveness of the EMB control strategy and failure control is verified through Simulink simulation.