Adaptive Fault-Tolerant Control for 4WID-4WIS Electric Vehicles under Steering System Failures

The four-wheel independent drive and four-wheel independent steering (4WID-4WIS) configuration enhances distributed control in intelligent electric vehicles. As a typical over-actuated system, its application in distributed control can provide various fault-tolerant control solutions to ensure vehicular safety. This paper proposes a hierarchical tire force allocation strategy for the 4WID-4WIS configuration based on constraint optimization. Additionally, it introduces an adaptive fault-tolerant control specifically for steering system failures. When steering failures arise, the fault-tolerant control system discerns the fault and sustains trajectory tracking performance using fuzzy control and control reallocations. Simulation results demonstrate that our strategy maintains trajectory tracking control performance, even under complete steering failures. In contrast, the vehicle loses control without fault-tolerant control, resulting in significant trajectory tracking errors in identical fault scenarios and raising the risk of serious traffic accidents.