Active Manipulator-Aided Docking of Underactuated Autonomous Underwater Vehicles

Underwater docking stations (DS) are essential for subsea resident autonomous underwater vehicles (AUV). Com-monly, the DS is passive and the AUV is designed with sufficient maneuverability to achieve docking. In this work, we propose an alternative approach for an AUV with low maneuverability by equipping the DS with a robotic manipulator arm to actively catch the approaching vehicle. In particular, we present kinematic analysis tools tailored towards the docking task and a dockability metric to determine and evaluate suitable docking poses. By means of this analysis, an optimal approach path can be determined for the AUV to follow during the docking process. To demonstrate the feasibility of active docking, preliminary experiments were conducted in a control environment using a hardware-in-the-loop (HITL) simulator and a simple control architecture. The experimental results are further analyzed to investigate the limitations of the approach.