Coordinated Electro-Hydraulic Composite Braking Method for Improving Energy Recovery in Emergency Braking

To enhance braking performance and energy recovery efficiency during emergency braking, an electro-hydraulic composite braking method integrating anti-lock braking system (ABS) based on model predictive control (MPC) is proposed. The proposed method ensures precise control of the tire slip ratio to effectively prevent wheel lock-up while maximizing the braking force generated from tire-road interaction. Leveraging the fast response of motors and the wide controllable range of hydraulic torque, regenerative and friction braking are coordinated within an optimization problem, which enables adaptive adjustment of regenerative and hydraulic braking torques, ensuring efficient energy recovery and braking safety at the same time. A unified optimization framework is designed to simultaneously consider braking torque fluctuation, slip ratio tracking, and braking deceleration, with computational redundancy significantly reduced. Finally, the hardware-in-the-loop (HIL) testing under different conditions are carried out. The results show that the braking distance reduced by 7.3 m, and the state of charge (SOC) is increased by 5.1%, which demonstrate the effectiveness of the proposed method in ensuring both braking performance and energy recovery efficiency.