Distributed fuzzy adaptive fault-tolerant control with unknown time-varying power drift signals and asymmetric dead-zones

Abstract

In this study, we consider the distributed fuzzy fault-tolerant control (FTC) problem for a class of interconnected nonlinear systems with multiple unknown time-varying power drift signals, asymmetric actuator, and output dead-zones. Based on our proposed dead-zone models, an effective distributed finite-time adaptive FTC strategy is developed. In previous studies, the unknown system powers were assumed to be positive odd integers that are greater than or equal to one and their boundaries were also assumed to be positive odd integers, but we relax these assumptions, where the powers are assumed to be unknown time-varying bounded real functions and their boundaries are real constants, and not necessarily positive odd integers. In addition, the proposed output dead-zone approximation model can achieve full approximation within a limited adjustable range, rather than the asymptotic approximation found in previous studies. Theoretical analysis proves that the tracking error of each subsystem converges to a small neighborhood of the origin in finite time. Finally, a simulated coupled inverted pendulum example is presented to demonstrate the validity of the proposed FTC strategy.