Adaptive fuzzy output tracking control of robot manipulators with unknown input saturations

This paper addresses the challenge of adaptive trajectory tracking control for robot manipulators in the presence of structural uncertainties, external disturbances, and unknown nonlinear input saturation. Fuzzy logic systems are employed to approximate both unknown structural uncertainty and the virtual controller term. We adopt a straightforward design approach to handle nonlinear input saturation, while also estimating the norm of the weight matrix and the upper bound of unknown parameters using an adaptive law. Leveraging the backstepping method, we propose an adaptive fuzzy controller. We demonstrate that the proposed control scheme guarantees the uniform asymptotic stability of the robot manipulators. Finally, simulation studies are conducted to showcase the effectiveness of the proposed control strategy.