Passivity-based controller-observer for robot manipulators

This paper deals with the velocity-observer based controller to solve the trajectory tracking problem for rigid robot manipulators, without using the velocity measurement. A remarkable feature of this observer-controller is that it originates from energy reshaping arguments, by analogy with the passivity-based methodology to robot control. Under assumption that the velocities are bounded, it is shown that the whole control system (robot plus controller plus observer) is semi-global asymptotically stable, and an estimate region of attraction is also given. Finally, simulation results on two-link manipulator are provided to illustrate the effectiveness of the controller-observer.