Extended Nicosia??Tomei velocity observer-based robot-tracking control

This study presents an observer-based control of robot manipulators for velocity estimation and trajectory tracking. The proposed scheme does not require the velocity feedback because velocity measurements may not be available because of cost and noise. The author introduces parameters involving the tracking and estimation errors and their derivatives into the observer-controller. Exploiting the structural properties, the author proposes the new combined form of observer-controller to ensure the closed loop stability of the tracking and estimation. Moreover, the author shows that the proposed controller-observer scheme achieves semi-globally exponential stability results for tracking errors and estimation errors. The proposed observer-controller facilitates the stability analysis and explicitly extends Nicosia-Tomei observer-based tracking control. To validate the proposed scheme, the author conducts numerical simulation of a two-link robot. The simulation results clearly indicate that the proposed scheme improves the error convergence for both trajectory tracking and velocity estimation.