Imperfect dynamical systems

Abstract

This paper proposes a finite-time fault-tolerant trajectory tracking control for a quadrotor system against external disturbances, parametric uncertainties and actuator faults without the need of fault diagnosis mechanism. First, a finite-time fault-tolerant control based on a multivariable integral terminal sliding mode control (TSMC) is proposed to separately accommodate the parametric uncertainties and actuator faults. Then, combined with an adaptive law, an adaptive fault-tolerant control (AFTC) is employed to eliminate the requirement of the prior knowledge on the uncertainty bounds and achieve high-precision trajectory tracking in a finite time. Besides, a finite-time exact observer (FEO) is incorporated to estimate and compensate for the disturbances in a finite time while keeping the control gains of AFTC to small values. The promising features of the proposed fault-tolerant control scheme include finite-time convergence and insensitivity to multiple faults and disturbances. The finite-time stability of the closed-loop system is proved by Lyapunov theory. Finally, the effectiveness of the proposed method is validated through extensive numerical simulations for a variety of working scenarios.