Synchronization and tracking control of 4WISBW system considering the differences in the characteristics of corner modules

To enhance vehicle stability and safety, the four-wheel independent steer-by-wire (4WISBW) system has garnered significant attention. However, the characteristics of corner modules, including model parameters uncertainty and disturbance torque, directly contribute to the deterioration of dynamic response in tracking control. And the differences in the characteristics leading to reduced synchronization performance in the 4WISBW system and hindering effective coordination. To enhance the synchronization and tracking control performance of the 4WISBW system, a novel control strategy, coupled with the fictitious master-generalized mean deviation coupling structure (FMGMDCS), is proposed. Firstly, the corner module dynamic model and the vehicle dynamic model are established. Subsequently, the impact of the differences in the characteristics on the system's tracking and synchronization control is analyzed. Next, the FMGMDCS and the angle synchronization controller based on a new reaching law sliding mode control (NRLSMC) are proposed to compensate for synchronization errors in the 4WISBW system caused by the differences in the characteristics of corner modules. Finally, a radial basis function neural network fast terminal sliding mode control (RBF-FTSMC) steering angle tracking controller is designed to enhance the tracking performance of corner modules. Simulation and experimental results indicate that the proposed control strategy can effectively solve the synchronization problem of the 4WISBW system and improve the system's tracking performance.