The Residual-Evaluation Based Event-Triggered Mechanism for Four-Wheel Independent Drive Vehicle Fault Tolerant Control

Exploding increment of electric control units in the new-generation electric vehicles could be poised to diminish the system's reliability. To this end, this article presents a residual-evaluation based event-triggered mechanism (ETM) fault tolerant control framework to ensure the controller's performance as well as address the potential faults in steer-by-wire (SbW) system. First, compared with conventional ETM, a residual evaluation function is formulated as a convex solution using linear matrix Inequalities, based on which the optimal tradeoff could be achieved between robustness of the uncertainty disturbance and the sensitivity to faulty signal. Then, the threshold of residual evaluation is determined by considering transmission errors, uncertain disturbances, and fault signals. Taking into account the faults in the SbW system, the stochastic model predive controller is thus developed to obtain additional direct yaw moment, as well as ensuring the vehicle lateral stability and path tracking performance. Furthermore, chance constraints will be incorporated to guarantee that the lateral stability index is confined within the safety boundary of phase plane. Finally, the effectiveness of the proposed architecture is verified through hardware-in-loop experiments. The results illustrate that our proposed controller possesses better path tracking and lateral stability performance while controller area network resources could also be reduced.