Motor-electric anti-lock braking by ideal wheel deceleration curve in battery electric vehicle

Friction-hydraulic braking system employs friction to dissipate kinetic energy, and motor-electric braking system utilizes an electric motor to convert kinetic energy into electric energy. To achieve rapid stopping and recover some energy, battery electric vehicles require adopting the motor to realize the anti-lock braking function, primarily by reducing friction-hydraulic operation. This is especially challenging for the motor-electric anti-lock braking system, for which almost all characteristics of the motor-electric differ from the friction-hydraulic. Many studies on anti-lock braking systems mainly focus on wheel slip ratio control, and some other research is related to wheel deceleration control. In this article, a parameter-tuned sliding mode control approach is designed to realize the optimal wheel deceleration by the motor-electric torque control, and an ideal wheel deceleration curve is developed as the optimal. A proportional-integral observer is used to compute the road adhesion coefficient. Real vehicle experiments are performed using a battery electric vehicle to illustrate the effectiveness of the designed approach. According to the obtained results and statistical analysis, the designed motor-electric anti-lock braking control approach based on wheel deceleration improves the braking performance of the vehicle.