Adaptive Fuzzy Fault-Tolerant Control with Non-affine Nonlinear Actuator Failures

This brief presents a solution to the fault tolerant control problem for nonlinear systems subject to nonlinear non-affine actuator faults and external disturbance. To address the system nonlinearities and actuator faults, fuzzy inference systems are introduced into the controller construction. To this end, two controllers are proposed where the first one is an adaptive controller designed to mitigate system uncertainties and actuator faults, whereas the second one is a robust term aimed at reducing the approximation discrepancy and also to handle external disturbances. The proposed scheme enables automatic handling of external disturbances and actuator faults through online adaptation of the controller. The Butterworth filter is employed to overcome the algebraic loop issue, ensuring the best estimation of the ideal controller. The stability analysis is conducted using Lyapunov second method. Numerical simulations are performed to validate the effectiveness of the controller.