Adaptive fuzzy output feedback dynamic surface sliding mode control for a nonlinear dynamic system

Abstract

Friction and deadzone nonlinearities in the nonlinear dynamic systems act often the main obstacles for higher motion control. It is difficult to achieve effective motion compensation for these types of nonlinearities by traditional linear control methodology without the aid of a proper estimation scheme on nonlinearity. Here, we present an adaptive fuzzy dynamic surface control scheme combined with state and nonlinearity observer and sliding mode control to estimate immeasurable state and compensate undesirable uncertainty on motion control for a strict output feedback nonlinear dynamic system. The adaptive laws of the fuzzy, friction and deadzone observer are derived from the recursive steps of the dynamic surface control. The boundedness and convergence of the closed-loop system are guaranteed by a Lyapunov stability analysis. The performance of the proposed control scheme is verified through simulation and experiment on the robot manipulator.