Abstract: In the regenerative braking of distributed drive electric vehicles on a long slope, the failure of one side motor can significantly weaken the braking strength and cause deviation due to imbalanced braking on both sides. Although cutting off the braking torque of the opposite side motor and actively compensating hydraulic braking can ensure the braking efficiency of the vehicle, it is impossible to correct deviation and continue to feedback energy. To solve the above problems, a new electromechanical hydraulic composite control method is explored based on the invented distributed/centralized dual-mode coupling drive system and electro-hydraulic braking system. Firstly, the feasibility of using the dual-mode coupling drive system for regenerative braking after a single motor failure is analyzed; Then, the vehicle dynamics modeling and controller design are conducted, and a model predictive control method combined with vector control to address the issue of poor precision in composite brake control is proposed; Finally, the composite control effect is verified through the hardware in the loop simulation. The research results indicate that, in addition to torque truncation and hydraulic compensation control, differential drive using the non-failed motor can ensure braking safety after the braking failure of one side motor. Afterwards, switching the two motors distributed drive to a single motor centralized drive can continue to perform regenerative braking and ensure the expected braking performance. The proposed electromechanical hydraulic composite control improves control accuracy by 64.83%, and the braking energy recovery value by 58.70%, effectively ensuring vehicle braking safety and energy recovery capability.

Key words: distributed drive, regenerative braking failure, dual-mode coupling drive, electromechanical hydraulic composite control, model predictive control