A Fault-Tolerant Trajectory Tracking Strategy of Four-Wheel Independent Drive Electric Vehicles Using Super-Twisting Sliding Model Control

Vehicle actuator faults can lead to loss of control, deviating from the intended trajectory, and even collisions or rollovers. Four-wheel independent drive electric vehicles (FWIDEVs) incorporate a redundant drive structure, thereby providing the ability for fault-tolerant control (FTC). However, ensuring both vehicle stability and trajectory tracking accuracy simultaneously in the event of vehicle faults remains a challenging issue. To address this issue, this article proposes a FTC strategy based on the super-twisting sliding mode (STSM) framework. First, front wheel steering angle compensation with trigger mechanism is introduced to enhance the vehicle's performance under fault conditions, with the corresponding vehicle model derived. Then, the hierarchical STSM-FTC strategy is designed based on the proposed model. In the upper layer, an STSM controller with an adaptive parameter tuning law is designed to enhance the robustness of the system. In the lower layer, a torque distribution algorithm is introduced to further ensure vehicle stability by using quadratic programming (QP). Finally, simulation and experiments demonstrated that the proposed strategy achieves significant improvements in accuracy and stability compared to existing strategies.