Design Method of Ship's Position Keeping Control System and Verification by Field Tests

High-accuracy fixed position keeping has come to be demanded with ships having special duties such as cable laying ships, ocean research ships and bridge construction ships for improving the accuracy and efficiency of works on ships. This paper presents a design method of position keeping control system used by the optimal regulator theory. Its practicality has been verified by field tests in a cable laying ship, which consisted of 3 kinds of tests, that is, a midship position keeping control, a bow-position keeping control and a stern-position keeping control while changing a set of heading by using a propeller, a bow thruster and a stern thruster.