Sliding mode variable structure control for the stability of independent drive electric vehicle

For fully taking the advantage of the feature of independence and controllability of two side motors in two-motor independent drive electric vehicle to enhance its stability, an eight-DOF human-vehicle closed-loop dynamics simulation platform is set up, incorporating single-point preview driver model for arbitrary path and 'magic formula' tire model. Based on sliding mode variable structure control theory, three different sliding mode variable structure controllers with constant approaching rate are designed with two side motors as actuators and yaw rate, mass-center sideslip angle and both yaw rate and mass-center sideslip angle as control variables respectively. The results of stability control simulation show that all three different controllers can effectively enhance the handling stability of vehicle in extreme working conditions, among which, the controller with both yaw rate and mass-center sideslip angle as control variables achieves the best results.