On asymptotic fixed-time controller design for uncertain nonlinear systems with pure state constraints

This study investigates the problem of asymptotic fixed-time tracking control (AFXTTC) for uncertain nonlinear systems (UNS) subject to pure state constraints. To study this problem, we define asymptotic fixed-time stability (AFXTS) and thus a criterion for determining AFXTS. Dynamic surface control (DSC) is combined with fuzzy logic systems (FLSs) to construct a new adaptive fuzzy asymptotic fixed-time controller. A barrier Lyapunov function (BLF) is introduced to ensure that constraints on all states are satisfied. The proposed criterion is used to analyze the AFXTS of the system, and the effectiveness and superiority of the theoretical analysis results are verified through simulations.