Novel Finite-Time Adaptive Fuzzy Fault-Tolerant Control for Fractional-Order Nonlinear Systems and Its Applications

To address the finite-time tracking control problem for fractional-order nonlinear systems (FONSs) with actuator faults and external disturbance, a novel strategy of the finite-time adaptive fuzzy fault-tolerant controller is presented in this paper by utilizing the finite-time stability theory and fractional-order dynamic surface control scheme combined with backstepping method. A new lemma is developed for analyzing the finite-time stability of FONSs in terms of fractional differential inequality, which modifies some existing results. Fuzzy logic systems are adopted to identify unknown nonlinear characteristics in FONS. In order to compensate for the influence of unknown external disturbance and estimation error for fuzzy logic systems, an auxiliary function is employed to estimate the upper bound of parameters online. Furthermore, a global coordinate transformation is first introduced initially to decouple the fractional-order dynamic system of a specific class of underactuated single-link flexible manipulator systems, thereby transforming it into lower triangular systems. Simulation analyses and experimental results verify the feasibility and effectiveness of finite-time tracking control algorithm.