Experimental assessment of an uncertainty-bounds estimator for an integral sliding disturbance observer

This paper presents an experimental evaluation of an uncertainty-bounds estimation algorithm for an integral sliding-mode disturbance observer. When applying a sliding-mode disturbance observer to compensating for unknown disturbances, it is usually difficult to determine the required switching gain whose magnitude should be large than some uncertainty bounds so as to ensure a sliding motion. In this paper, an uncertainty-bounds estimator is incorporated into the integral sliding-mode disturbance observer to adaptively determine the upper bounds on the norm of the uncertainties. Moreover, experimental studies are conducted on a two-link robotic manipulator to investigate the effectiveness of the uncertainty-bounds estimator.