Braking Force Coordination Control Strategy for Electric Vehicles Considering Failure Conditions

This paper presents a braking force coordination control strategy for electric vehicles based on a hierarchical control architecture. The proposed strategy integrates electronic brakeforce distribution (EBD), direct yaw control (DYC), anti-lock braking system (ABS), and braking force reconstruction functions to effectively enhance braking stability under brake actuator failure conditions. First, a full-vehicle model is established to investigate the braking force coordination process during braking. Then, by analyzing the coupling relationship between the yaw moment and DYC control, a dynamic ABS/DYC coordination strategy is developed. A dynamic computation model of the braking force limited weight coefficient is established, and a three-level braking force coordination mechanism is constructed according to the braking force limited state of each wheel. This mechanism achieves integrated coordination and reconstruction of longitudinal and lateral braking forces. Considering road adhesion, failure sequence, and failure location, eleven typical verification scenarios are designed. Simulation results show that, compared with uncoordinated control methods, the proposed method not only can effectively handle with muti-wheel failure scenarios, but also can reduce the braking distance by up to 7.05% and the lateral deviation by 26.74%, effectively improving the braking safety of electric vehicles.