Fuzzy adaptive tracking control for switched nonlinear systems with full time-varying state constraints

In this paper, a novel fuzzy adaptive tracking control scheme is presented for a class of nonstrict-feedback uncertain switched nonlinear systems by taking into account constraint. The considered switched nonlinear system contains unknown nonlinearities. In the design process, firstly, the problem of state constraints is coped with by utilizing the asymmetric time-varying barrier Lyapunov functions (TABLFs), and the problem of "explosion of complexity" is solved by dynamic surface control (DSC) technology. Secondly, fuzzy logic systems (FLSs) are utilized to approximate the unknown nonlinear dynamics. Under the framework of adaptive control design, the switched adaptive state feedback controller is designed, which can guarantee all states cannot violate their constrained sets. Then, based on the Lyapunov function and average dwell time (ADT) approach, the theoretical analysis is provided for the closed-loop systems within constraint performance bounded. Finally, a numerical example is proposed to further elaborate the effectiveness of the presented control scheme. (C) 2019 Elsevier B.V. All rights reserved.