Nonlinear switched diving control for under-actuated autonomous underwater vehicles

In this paper, the diving control for the non-neural buoyantng Remus-like [1] under-actuated autonomous underwater vehicle (UAUV) with one thruster in the aft end of the hull, which is equipped with two stern planes and two rudder planes mounted in a cruciform pattern near the aft end of the hull, is considered. The small gain control is usually used to drive the under-actuated autonomous underwater vehicle (UAUV) to dive to the desired depth in order to avoid the stall phenomenon resulting from the pitch angle bigger than critical value. But in this case the UAUV maybe dive slowly to the desired depth. In this paper, nonlinear switched diving control is considered in order to drive the UAUV to dive as fast as possible to the desired depth in the case of avoiding the appearance of stall. The effectiveness of the proposed control is illustrated through extensive simulations.