Observer-based robust adaptive fuzzy tracking control in robot arms

In this paper, an observer-based robust adaptive fuzzy tracking control for rigid robotic systems is presented with plant unknown. It is assumed that only the joint angular positions are measured, the joint angular velocities are estimated via a fuzzy observer. First, we design a nonlinear observer based on fuzzy basis functions (FBF) to estimate the joint angular velocities in which a fuzzy logic system is introduced to learn these unknown dynamics by an adaptive algorithm. Then, an indirect adaptive fuzzy controller based on observer is presented. The developed control scheme is simple and computationally efficient, since it does not require a knowledge of either the mathematical model or the parameterization of the robotic dynamics. Simulation results demonstrate the applicability of the proposed method in order to achieve desired performance.