Velocity observer-based fuzzy adaptive control of multi-link robotic manipulators

This paper introduces a velocity observer-based fuzzy adaptive control scheme for nonlinear multi-link manipulator robot system with actuator dynamics. The system has uncertainty and unknown state derivative. The proposed approach combines the dynamic fuzzy logic system (DFLS) and nonlinear observer to deal with the tracking control problem of multi-link manipulator system. At first, the nonlinear system is transferred to a strict-feedback affine-like form. Then, we adopt the DFLS to approximate the nonlinear unknown functions and the observer is used to estimate the unmeasured states. Based on the Lyapunov approach, the adaptive laws of DFLS are obtained and the stability of the closed-loop system is guaranteed. Finally, simulation and experimental results are introduced to illustrate the effectiveness of our approach.