Adaptive sliding mode fault-tolerant control for nonlinearly chaotic systems against network faults and time-delays

The robust fault-tolerant control (FTC) problem against network faults and time-delays of a class of nonlinearly coupled chaotic systems is addressed in this paper. Two kinds of faults on networks, that is, network deterioration and signal attenuations, and a perturbation caused by general nonlinear couplings and time-varying bounded delays are considered in the FTC chaotic system designs. A sliding mode control strategy is proposed, guaranteeing the compensation of the faulted and perturbed couplings by means of adaptive estimations of unknown controller parameters. It is shown that, through Lyapunov stability theory, the proposed adaptive sliding mode controllers are successful in ensuring the achievement of asymptotic synchronization of chaotic systems even in the case of faulted and perturbed couplings. The proposed controller is tested by simulation on a unified chaotic system.