An Adaptive Control Method for Ship Path Tracking Accounting for Ship-Ship Hydrodynamic Interaction

Due to the advances of shipbuilding technology, ships are gradually developing in the direction of large-scale and intellectualization. However, the hydrodynamic interaction has been pronounced as the increase in dimensions of ships and has become a significant influencing factor of ships sailing in restricted waters, and the accuracy of ship motion control is limited due to the complex environmental disturbances. Based on the potential flow theory the Hess & Smith panel method, the ship hydrodynamic interaction is calculated in real time, and based on the MMG equation, an adaptive path tracking control method is devised that can be integrated with motions of equation of ships moving in restricted waters. Through frequency domain transformation, the ship response model in restricted waters is simplified to a ship dynamic model, and the model missing terms in the simplified process is adaptively estimated. Accounting for the computational efficiency of hydrodynamic interaction, a path tracking controller for ships in restricted waters is designed based on PD control method with appropriate parameters. By comparing the control effect of PD controller in the model without adaptive estimation and adaptive estimation model, the effectiveness of adaptive estimation is verified.