Cyclic Performance Monitoring-Based Fault-Tolerant Funnel Control of Unknown Nonlinear Systems With Actuator Failures

This article is concerned with the problem of fault detection, isolation, and compensation for the multiple-input single-output nonlinear systems in the face of actuator failures. It is focused on the cases of possibly simultaneous failures and unknown inherent nonlinear dynamics, which render the existing solutions infeasible. To conquer these challenges, a novel fault-tolerant funnel control approach based on cyclic performance monitoring and switching mode rearrangement is devised. It detects and locates the faulty actuators and achieves reference tracking with the predefined rate and accuracy, no matter whether the actuator fails or not. It also exhibits a significant simplicity, without parameter identification or function approximation and with less switching modes than other fault isolation algorithms. The theoretical findings are illustrated by a simulation study on a high-speed train.