Autonomous docking of a feeder vessel

Autonomous sailing is seen as one of the possible solutions to cope with the decrease in qualified personnel, to minimise the risk to humans and ships in challenging conditions, and to decrease the environmental impact of the transport sector. Autonomous sailing is not limited to moving the vessel safely through the seas, but it also includes docking the vessel. A feeder vessel that distributes cargo spends a relative large percentage of its time on (un)docking, compared to a seafaring cargo vessel. Automating this part of the operation might save significantly on resources. The objective of this work is to automatically approach a dock for an underactuated vessel. It comprises the design of a time-dependent trajectory, as well as a controller that can track this trajectory. The solution is tailored for our 71m long feeder vessel designed for the EU-H2020 Moses project. The focus is on approaching the dock from cruising speed until the speed of the vessel is near-zero. The result of the study is a high-fidelity time simulation that shows the behaviour of the vessel in combination with the control system when it approaches a dock. From these simulations it can be concluded that the ship can approach the dock with only azimuthing thrusters to a speed when the bow thrusters become effective. The then fully actuated vessel might be safely docked with a dynamical positioning system