Vehicle Adaptive Control for Underwater Intervention Including Thrusters Dynamics

This paper investigates the effects of including the thruster dynamics within the full-dimensional adaptive control of an underwater vehicle. In particular, the intervention case, i.e., small movements around a steady reference trajectory and the presence of the ocean current, are of interest. The thruster dynamics influences the closed loop causing undesirable effects if not properly taken into account. Furthermore, as known, the adaptive control can fail if the performed trajectory is not sufficiently exciting causing eventually the dynamic parameters drift and bursting phenomena. Therefore, for the intervention case, these drawbacks of the adaptive control have to be considered. In particular, a reduced version of the controller, taking into account only the persistent dynamic effects, is implemented. Finally, numerical simulations validate the discussion made.