Disturbance-Observer-Based Tracking Control for A Two-Link Robotic Manipulators with External Disturbances

Abstract

In this paper, two tracking control laws are designed for two-link robotic manipulators with external disturbances. A new nonlinear disturbance observer (NDO) is studied, and the global asymptotic stability of the given disturbance observer is guaranteed by appropriate assumptions on the system parameters and the physical structure. By utilizing the NDO, a nonlinear tracking controller is presented in the present of dissipation force and friction force. The tracking errors converge to zero by tuning the designed parameters. In addition, the sliding-mode-based tracking controller is also discussed. A simulation example is given to show the validity of the control algorithms.