Nonlinear vehicle dynamics control for EV with 4 in-wheel motors

In this paper, a motion follow controller for a 4-wheel-drive electric vehicle based on one track non-linear vehicle model and variable structure control (VSC) theory was designed. Combining the controller with optimal control allocation algorithm which takes into account of longitudinal/lateral force couple characteristic for tire under critical situation, we designed the vehicle stability control system. By using veDYNA, the double lane change simulation was carried out to verify the validity of control method. The results of simulation show the proposed control method could stabilize vehicle well under critical situation. The reference model plays an important role at stabilizing vehicle attitude, but inevitably alters the steering characteristic, which brings certain conservative. Actual control allocation could match the general requirement well by taking into account of tire force characteristic.