Self-tuning Regulators Used for Ship Course Keeping

Abstract

On the basis of self-tuning regulators attention is given to theoretical and practical aspects dealing with the application of adaptive control to ship course keeping. In this papar a LQG optimal controller is developed which avoids the diffioulty of solving Riccati equation on line. An extended state vector Kalman filter is designed to improve its robustness and convergence. Parameters in both the LQG controller and Kalman filter are estimated by rernrsive least square identification so that the scheme has a high degree of adaptability in the time-variant environment. The control strategies are implemented in a microcamputerized adaptive control unit which has been attached to the autopilot on board “YUHONG” and undergone the sea trials. Results of experiment show that self-tuning regulators reduce the propulsion losses in addition to keeping the course satisfactorily.