Adaptive fixed-time tracking control of nonlinear systems with unmodeled dynamics

The article explores the fixed-time tracking control (FTTC) problem of strict-feedback nonlinear systems with unmodeled dynamics and dynamic disturbances. For the first time, a novel fixed-time dynamic signal is presented to address unmodeled dynamics. Associating adaptive backstepping control technology and fixed-time Lyapunov stability theory, an adaptive FTTC strategy is constructed, which guarantees that all signals of the closed-loop system are bounded and the tracking error can converge to a small region of zero within a fixed-time range. Finally, two simulation results illustrate the feasibility and validity of the suggested strategy.