Torque distribution and stability control of distributed drive electric vehicles considering torque loss and wheel slip

The hub motor of a distributed drive vehicle, as the main executing structure of the drive system, may produce varying degrees of torque loss during operation, which directly lead to the deterioration in the yaw stability of the vehicle and wheel slip especially when the vehicle is driving on low adhesion road. In this paper, a coordinated torque distribution control strategy considering wheel slip is proposed in the case of hub motor torque loss. By designing a torque constraint to prevent wheel slip and a torque distribution strategy considering torque loss, the four-wheel torque is distributed coordinately. Among the torque constraints, the fuzzy threshold method and the nonlinear feedback method are used to calculate the desired wheel torque, and then the torque constraint method considering wheel slip is designed based on particle swarm extension control theory, which can switch the torque constraint mode adaptively. To ensure the stability of the vehicle, the stability criterion is designed based on the phase plane and the yaw moment controller is designed by the sliding mode algorithm. The torque distribution strategy considering the torque loss is combined with the torque loss of the hub motor and the normal wheel torque distribution is reconstructed by the quadratic programming method. Finally, the proposed torque coordination distribution strategy is verified by simulation and hardware-in-the-loop test to prove the effectiveness of the control strategy.