Robust control of remotely operated vehicle in the vertical plane

This paper addresses the problem of stabilizing and trajectory tracking control of a remotely operated vehicle (ROV-Observer) in the vertical plane. The underwater vehicle is not actuated in the pitch direction and cannot be locally asymptotically stabilized by continuous feedbacks which are functions of the state only. In the present note, exponential convergence is obtained by considering time-varying feedbacks which are only continuous. Furthermore, using the backstepping technique and the tracking error dynamics, the system states are stabilized by forcing the tracking errors to an arbitrarily small neighborhood of zero.