REEXAMINING THE NICOSIA-TOMEI ROBOT OBSERVER-CONTROLLER FROM A BACKSTEPPING PERSPECTIVE

Many robot controllers require not only link position measurements but also link velocity measurements; however, most robotic systems are on ly equipped with link position measurement devices, To address this pr oblem, we present an observer-based controller for the link position t racking, output feedback control of robot manipulators, The approach i s based on an observed integrator backstepping procedure which allows us to obtain a semi-global exponential stability result for the link p osition-velocity tracking error, Implementation of the proposed contro ller on a two-link direct-drive manipulator produces results which ind icate good link position tracking performance and robustness against p ayload variations.