Four-wheel-steering Vehicle Control via Sliding Mode Strategy

It presents a sliding mode strategy integrated with rear angle and yaw moment to control the four-wheel-steering vehicle. The slip angle and yaw rate of vehicle gravity center are controlled variables. One input of sliding mode controller is the front steering angle which is measured by sensor, while others are estimated values of disturbance bound and the errors of slip angle and yaw rate. Furthermore, the disturbance bound estimator, and sliding mode controller of rear wheel angle and yaw moment are designed based on the dynamic model and ideal vehicle steering model. The results show that the sliding mode control strategy presents good performance and robustness under different driving conditions. After changing vehicle parameters, it found that maneuverability and stability of the vehicle was guaranteed through tracking the yaw rate and zero degree of side slip angle.