Observer-Based Adaptive Decentralized Control for Interconnected Time-Delay Nonlinear Fully Actuated Systems With Nonsmooth Actuator Dynamics

This article investigates the observer-based adaptive decentralized control problem for a class of uncertain interconnected nonlinear fully actuated systems (FAS), considering nonsmooth actuator dynamics including actuator failures and unknown control gains. Based on the dynamic gain scaling technique, a dynamic state observer is constructed. By utilizing the high-order FAS (HOFAS) approach, an adaptive decentralized output feedback controller is designed and a closed-loop structure of the fully actuated subsystems is derived. This structure takes actuator loss of effectiveness, unknown control gains, and unstructured uncertainties into account in the interconnected time-delay subsystems. By selecting suitable Lyapunov-Krasovskii (L-K) functionals, the time-delay terms can be removed, ensuring that all signals of the overall closed-loop system converge to a bounded region. Finally, two simulation examples validate the efficacy of the proposed strategy.