A hybrid approach to underwater docking of AUVs with cross-current

This paper proposes a docking maneuver for an underactuated autonomous underwater vehicle (AUV) to dock into a funnel shaped docking station. The novelty of the proposed approach is enabling an underactuated AUV that is unable to control its sway motion, to dock with no crab angle, in the presence of cross-currents. Docking without a crab angle can be beneficial in cases where the geometry of the docking station entrance does not allow entering with crab angles. In order to successfully dock under such restrictions, a path planner and two guidance laws are proposed. By properly switching between the two guidance laws, it is possible for the vehicle to slide cross-current into the docking station.