Design of adaptive compensators for the control of robot manipulators robust to unknown structured and unstructured parameters

Abstract

In this paper, a new adaptive-robust control approach for robot manipulators is developed. The adaptive-robust control law is not only robust to unknown structured parameters but also robust to unknown unstructured parameters such as unstructured joint friction and disturbances. The bounded disturbances and unstructured model are taken into account in a dynamic model and it is assumed that the structured and unstructured parameters are unknown. The structured and unstructured parameters are distinguished between parameters and these parameters are treated separately. Next, new parameter estimation functions are developed for each of the 2 uncertainty groups. After that, the developed dynamic adaptive compensators for the unknown structured and unknown unstructured parameters are combined and the control law is formulated by the combination of the compensators, including the proportional-derivative feedforward control. Based on the Lyapunov theory, the uniform ultimate boundedness of the tracking error is obtained.