A multi-closed loop pressure control in electro-hydraulic brake system for electric vehicle

To validate and further improve the performance of pressure-building of an electro-hydraulic brake (EHB) system for electric vehicle, a simplified EHB framework based on permanent magnet synchronous motor (PMSM) is proposed in this paper. Except for the control logic, the hydraulic brake actuator in the proposed EHB system is analysed and modelled in AMESim. Then, the output characteristics of the hydraulic brake actuator model are studied and analysed, which prove the validity of the actuator model established in AMESim. Then, the hydraulic brake actuator based on the PMSM is analysed and modelled in Simulink. Then, according to the models of the hydraulic actuator, a multi-closed loop pressure control strategy is proposed and is applied in the co-simulation based on AMESim and Simulink. The research and simulation results show that the average pressure of the front and rear brake wheel cylinders can reach the target within 0.2 s, and the PMSM output rotate speed tracks the target well. The multi-closed loop pressure control strategy proposed in this paper shows a faster response in pressure-building, which can be regarded as a significant advantage of electro-hydraulic brake system.