Robust Adaptive Trajectory Tracking Control for Robot Manipulator With Friction Disturbances

A robust adaptive trajectory tracking control strategy is proposed in this paper for the trajectory tracking problem of the robot manipulator with friction disturbances. Firstly, a robot manipulator trajectory controller with a friction model is designed using the backstepping method, and a first-order filter is applied to deal with the complex derivation problem of the virtual control input. Then, a disturbance observer is designed to estimate the external time-varying disturbances online. We use an adaptive law to update the parameters of the observer. The Lyapunov theory proved the closed-loop system to be semi-globally asymptotically stable. The simulation results show that the robot manipulator can overcome the external disturbances well and track the trajectory quickly and accurately. The control scheme effectively improves the tracking accuracy of the system.