An Active Disturbance Rejection Controller for ship steering

An Active Disturbance Rejection Controller (ADRC) was proposed for ship steering to overcome the classic PID defects. The traditional PID control has a wide application on ship autopilot because of its simple structure and obvious efforts. But because of the strong nonlinearity, uncertainty of ship´s movement and the dynamic restraints of rudder, the PID control method can not control the ship perfectly. So an Active Disturbance Rejection Controller (ADRC) was proposed for ship steering. The ADRC is inherited from PID method and developed by improving the classic PID defects. This paper introduces the principle, characteristics and learning algorithm of the ADRC. Then design the ADRC ship controller and apply it to ship steering control. At last, simultate this controlling method for ship steering in consideration of disturbances of wind, wave and current and without them respectively. And by comparing with the results under control of PID controller to show that the ADRC can improve the control performance and has better adapt ability and strong robustness to the ship model.