Adaptive Control for Uncertain High-Order Fully Actuated Nonlinear Systems With Deferred Constraint

This paper addresses the stabilization of nonlinear strict-feedback systems subject to deferred constraint by employing the higher-order fully actuated (HOFA) system approach. Initially, the constrained systems are converted to unconstrained systems by invoking a shift function and a time-dependent transformation function. Additionally, fuzzy logic systems (FLSs) are leveraged to approximate unknown nonlinearities. Building on the backstepping technique and leveraging the HOFA system approach, an adaptive fuzzy controller is designed. It is rigorously demonstrated that all signals within closed-loop systems remain bounded and that the output signal does not violate the deferred constraint. Finally, the proposed control scheme's efficacy is confirmed through its application to single-link robotic systems.