Vehicle yaw stability-control system design based on sliding mode and backstepping control approach

A yaw stability-control system is designed to make vehicle yaw rate follow its reference in this paper. Based on the sliding-mode and backstepping approach, the cascade control system is combined with a tire/road force observer and a yaw stability controller. The tire/road force observer considers wheel longitudinal force as an unknown input to wheel dynamics and uses the sliding-mode method to reconstruct it. The yaw stability controller is designed based on a model about vehicle yaw rate, and the wheel dynamics were chosen according to the vehicle situation. In backstepping framework, brake torque is calculated in two steps. The performance is evaluated in a critical cornering maneuver situation through simulation with a multibody vehicle dynamics software, and the result indicates that the proposed controller can significantly maintain vehicle stability for active safety.