Operating experience with a high-precision track controller for commercial ships

This article summarizes operating experience with a commercially produced track controller for ships, which has been installed on a considerable number of different ships, using a variety of position measurement systems. The controller is supplied with waypoint and radius information. Based on this information, it constructs a full manoeuvre trajectory for track changes. The ship is kept to this reference path using feedforward control from the trajectory construction in combination with LQG feedback control. The Kalman filter can be adapted to the characteristics of the particular position measurement system. Detailed performance results are presented for both track-keeping and track-changing phases, recorded during a recent voyage of a Norwegian ferry.