Electro-hydraulic composite stability control for regenerative braking failure of in-wheel motors drive electric vehicle

Abstract

The in-wheel motor simplifies the structure of drive system and improves dynamic performance of vehicle. However, the regenerative braking failure of unilateral motor could greatly reduce braking strength and cause the instability of vehicle. The existing control methods are difficult to guarantee the braking performance and driving stability at the same time. To resolve this fail-safe problem, an electro-hydraulic composite stability control method is proposed and verified. Firstly, the vehicle model, the in-wheel motor model, and the hydraulic braking system model are built. Secondly, the electro-hydraulic composite stability control method is proposed and a stability controller based on model predictive control algorithm is designed to solve the problems of model uncertainty and external interference in the control process. Thirdly, the control effect of proposed method is compared with torque truncation control, hydraulic compensation control, and yaw stability control. Finally, the electro-hydraulic composite stability control method proposed in this paper is verified and tested on the real vehicle. The results show that the combination of the torque truncation control, the hydraulic compensation control, and yaw stability control could improve the driving stability of vehicle and meet the demand of braking intensity.