Straight Running Stability Control Based on Optimal Torque Distribution for a Four in-wheel Motor Drive Electric Vehicle

An electronic stability control algorithm is proposed for a four in-wheel motor independent-drive electric vehicle (4MIDEV) utilizing traction torques distributed to separated motor driving systems to improve vehicle stability. A 2-DOF vehicle dynamics model, an upper level controller, and a torque distribution algorithm are designed for the straight running stability control system. A 2-DOF dynamics model is used to get the reference dynamics parameters according to the driver's intention and the realistic vehicle status; the upper level controller is used to adjust yaw moment in order to ensure the yaw stability and get ideal yaw moment.; and the lower level controller is used to distribute yaw moment to four driving motors. Then the stability control strategy is validated by simulation. The vehicle dynamics model is built in Carsim, while the straight running control strategy proposed in this paper built in MATLAB/Simulink. In this paper, the wheel speed, the lateral offset distance and the yaw rate of the proposed control strategy are compared with those without control, in the maneuvers of μ-split road and washboard road According to the result, it can be concluded that the straight running stability control strategy can improve the stability of the 4MIDEV, and decrease the reliance on driver in emergency situations.