In this paper, the authors discuss a fully automatic berthing system and actual tests using a small training ship, Shioji Maru. The ship is about 440 gross tonnage and furnished with a controllable pitch propeller, a bow thruster and a stern thruster to which a computer can easily be linked. The system developed is composed of an electro-optical position measuring system and the computer software necessary for manoeuvring the ship.

The electro-optical position measuring system can measure a distance between the ship and a target on a berth within 4 cm accuracy and cover an area out to about 100 m range. The manoeuvring is divided into two stages. The first one is from a start line to a transition point off the final berth. At this point, the ship must be stopped in an alongside attitude to the berth. In the second stage, the ship is pushed by the thrusters in an athwartships direction towards the berth and the final speed at the berth must be limited to within 0.5 ms. The computer software generates an appropriate strategy following an approach line which has been determined in advance.

According to the actual tests under slightly rough sea conditions, the system could manoeuvre the ship along the approach line by a direct path and maintain her final speed within the predetermined limit.