Observer-based Adaptive Fuzzy Control for Strict-feedback Nonlinear Systems with Prescribed Performance and Dead Zone

This paper proposes an observer-based fuzzy controller for strict-feedback nonlinear systems. A fuzzy state observer is designed to estimate unmeasurable system states via a fuzzy logic system to approximate the unknown nonlinear functions of the system. A tangent prescribed performance function is utilized to gather the tracking error in a small neighborhood of the origin. The control input is designed to deal with the dead-zone property of the system. The proposed controller can guarantee that all the signals in the closed-loop system are semi-globally, uniformly, and ultimately bounded. Simulation results demonstrate the effectiveness of the proposed controller.