Finite‐time adaptive fault‐tolerant control for output‐constrained interconnected systems with unknown control coefficients

Abstract

AbstractThis article studies the adaptive finite‐time tracking control problem for a class of output‐constrained nonlinear interconnected systems with unknown actuator faults and parametric uncertainties. By integrating the lower bounds of unknown virtual control coefficients into the Lyapunov functions design, an adaptive control strategy is proposed on the basis of adaptive estimations and some smooth functions, which make the controller effectively compensate the effects of unknown virtual control coefficients, unknown interconnected terms, and other uncertain nonlinear functions. Besides, the controller can also compensate the effect of actuator faults by fusing a two‐step design method into the backstepping design framework. Simultaneously, in view of the output constraint requirements, a barrier Lyapunov function is introduced, and it is a more general one that can reckon with time‐varying asymmetric output constraints. Furthermore, in light of the finite‐time stability criterion, all the signals of system are bounded and the tracking performance can be guaranteed in a finite time. Finally, the effectiveness of the proposed method is validated by some simulation results.