Fuzzy state observer based command-filtered adaptive control of uncertain nonlinear systems

This paper is devoted to the precise tracking control problem of uncertain nonlinear systems in strict feedback form with unmeasured states. Adaptive fuzzy observer is designed to reconstruct system states with nonlinear feedback term. The weight update laws of fuzzy systems are developed by observer error. Meanwhile, the output feedback control signal is designed based on the obtained fuzzy observer and nonlinear differentiator. The stability of the whole closed-loop system is shown to be ultimately uniformly bounded(UUB) by Lyapunov method. Finally, results performing on numerical example validate the effectiveness of the proposed control scheme.