Design of adaptive sliding mode controller for robust yaw stabilization of in-wheel-motor-driven electric vehicles

A robust yaw stability control system is designed to stabilize the vehicle yaw motion. Since the vehicles undergo changes in parameters and disturbances with respect to the wide range of driving condition, e.g., tire-road conditions, a robust control design technique is required to guarantee system stability. In this paper, a sliding mode control methodology is applied to make vehicle yaw rate to track its reference with robustness against model uncertainties and disturbances. A parameter adaptation law is applied to estimate varying vehicle parameters with respect to road conditions and is incorporated into sliding mode control framework. The control performance of the proposed control system is evaluated through computer simulation using CarSim vehicle model which proved to give a good description of the dynamics of an experimental in-wheel-motor- driven electric vehicle. Moreover, field tests were carried out to verify the effectiveness of the proposed adaptive sliding mode controller.