LQG approach for the high-precision track control of ships

Design ideas and experiences gained during the development of an adaptive high precision track controller for ships are summarised. The controller is installed on a number of different ships, using a variety of position measurement systems. The design follows the spirit of the LQG paradigm combined with a model following feedforward strategy. The ship is kept to a manoeuvring trajectory through a combination of feedforward and LQG feedback control. The variances and weighting coefficients for the LQG controller are chosen systematically. The large number of design parameters is reduced by appropriate model scaling. In addition, a decomposition structure of the Kalman filter is exploited to reveal the important tuning parameters.