Control-oriented modelling of a hybrid AUV

This paper introduces a control-oriented model for a class of autonomous underwater vehicles (AUVs) characterized by an actuation system that includes propellers, internal weight motion and ballast charge/discharge. Since this kind of actuation combines the actuation of both oceanic gliders and self-propelled AUVs, these vehicles are termed hybrid vehicles. The modelling results are employed in the definition of an adaptive backstepping control, using a fuzzy approximator in terms of Gaussian function in order to cope with model uncertainties and disturbances. Lyapunov stability of the control is proved and simulations are shown for a typical water sampling operation.