Path Following Control of the Underactuated Ship Based on Redefined Output Model-Free Adaptive Control

Controlling a ship to follow a desired path is crucial for achieving a high degree of autonomy in intelligent ship sailing. In this paper, a redefined output model-free adaptive control(RO-MFAC) scheme is proposed for automatic ship path following control. First, a MFAC scheme only requires the input data of the rudder angle of the ship system and the output data of the yaw angle is proposed. Then introduce the linear sum of both heading angle and angular velocity as the redefined output to achieve better control by stabilizing ship heading. Continuously correct the input data of the rudder angle to change the ship's direction by the difference between the output data and the ideal state. This algorithm doesn't need the explicit model information of the ship. So that, the complex modelling process of the ship can be avoided. Simulation results show that the scheme based on RO-MFAC provides an ideal control effect and good applicability to different complex operation processes of intelligent ships.