Output regulation of Euler-Lagrange systems based on error and velocity feedback

This paper considers robust output regulation of uncertain Euler-Lagrange (EL) systems by error (or relative position) and velocity feedback. We shall develop an adaptive internal model approach for the problem. Particularly, the proposed control law does not require apriori knowledge of reference signal and its derivatives, which are commonly assumed in literature. It enables a self-learning mechanism of the closed-loop EL systems where the adaptive internal model-based controller is able to learn the desired trajectories and adapt itself to the uncertain plant parameters. We also present a numerical example to illustrate the proposed result.