Research on control strategy of electric-hydraulic hybrid anti-lock braking system of an electric passenger car

Equipped with the regenerative braking system, electric vehicle coordinates friction braking and regenerative braking appropriately in normal braking conditions and activates anti-lock braking system (ABS) in emergency braking conditions. This paper mainly focuses on the control strategy of electric-hydraulic blended brake for ABS control of an electric passenger car. According to the variation of the adhesion coefficient under different roads, the maximum adhesion force and the optimal slip ratio are calculated in real-time. Then, the control strategy of electric-hydraulic hybrid ABS, in which regenerative braking and hydraulic braking are coordinated in order to obtain the maximum available road adhesion and guarantee vehicle´s braking stability, is proposed. Based on the control strategy developed, simulations and test-bench experiments are carried out. Simulation and test results indicate that braking stability and control performance of vehicle on different roads are guaranteed by the proposed hybrid ABS control, validating the feasibility and the effectiveness of the algorithms. Compared with conventional hydraulic ABS, the electric-hydraulic hybrid ABS, ensuring better braking performance on various road surfaces, provides a good solution to active safety control of EVs.