Adaptive Predefined-Time Fuzzy Control for Nonlinear Systems Subject to Unknown Control Direction and Mismatched Disturbances Based on Command Filter Technique

This article proposes an adaptive predefined-time event triggered fuzzy tracking control strategy for strict-feedback nonlinear systems with unknown control direction and mismatched disturbances by applying command filters. The Nussbaum-type function is employed to tackle the unknown control direction problem, and the fuzzy logic systems (FLSs) are applied to model the nonlinear functions. And then, command filters are adopted to deal with the problems of complexity explosion, and the event-triggered technique is exploited to conserve communication resources. With the help of backstepping mechanism and predefined-time stability theory, the constructed adaptive control scheme is proposed to ensure all signals in the closed-loop system are bounded and that the tracking error converges to a residual set. Finally, a simulation example proves the validity of presented control mechanism.