Robust controller design for a class of nonlinear robot manipulators with actuator dynamics

A robust controller is proposed to achieve accurate tracking for a class of nonlinear uncertain robot manipulators with actuator dynamics. A dynamic model is derived that incorporates the manipulator dynamics with the actuator dynamics. The parameter uncertainty in the model is quantified using the linear parameterization technique. The proposed switching controller guarantees the global asymptotic stability. To rectify the chattering caused by the switching action of the controller, the controller is modified into a smoothed form by putting a boundary layer around the sliding surface. It is shown that the smoothing controller guarantees the uniform ultimate boundedness of the actual trajectory. Simulation results show the feasibility and excellent tracking performance of the controller.