Research on Electro-Hydraulic Composite ABS Control for Distributed Driving EV

Pan Jin1, Pan Hao2, Pei Xiaofei3, Chen Zhenfu2, Zhang Jie1 1. Zhejiang Wanxiang Precision Industry Co., Ltd., Hangzhou 311202; 2. Hubei Key Laboratory of Advanced Technology （ of Automotive Components, Wuhan University of Technology, Wuhan 430070; 3. School of Automotive Engineering, Wuhan University of Technology, Wuhan 430070） Abstract According to the characteristics of distributed driving electric vehicle that the regenerative braking torque【 】and the hydraulic braking torque could be regulated independently, a hierarchical control strategy for electro- hydraulic composite ABS is proposed. In the upper control layer, a slip rate control based on integral sliding mode is introduced. In the lower control layer, the electro- hydraulic braking torque distribution based on the mode switching is achieved between the regenerative braking and hydraulic braking. According to the regulation coefficient, torque demand, maximum regenerative braking torque and threshold of hydraulic braking torque, torque distribution is divided into seven control modes. The ABS simulation tests are implemented on the high/low adhesion road with different initial speed. The results show that the wheel- slip control precision is improved for electro- hydraulic composite ABS, and the hydraulic braking torque maintains relatively stable with the fast compensation of regenerative braking. Key words: Distributed driving electric vehicle, Electro- hydraulic composite braking, ABS, Sliding-mode control, Braking torque distribution