계류선을 이용한 선박 자동 계선법에 관한 연구

A Study on Automatic Berthing System Using Mooring Line

The system is an automatic berthing system using the mooring line. It is to use mooring line for berthing process, and only consists of a mooring device equipped on a ship. The berthing process maintain parallel with quay by controlling breast line of forward-side and aft-side. The dynamic characteristics of ship are analyzed according to the influence of the mooring lines, and the berthing stability is ensured by controlling the torque and angular velocity of the hydraulic motor connected to the mooring line. To validate the berthing stability, numerical analysis and control experiments are performed in conditions of a changing center of gravity with even-keel and trim by stern. The variables affecting the berthing stability are estimated in different settings by analyzing the non-linearity of the ship due to the mooring line. System modeling is done using the bond graphs method, and PID controller is designed using the reference model. The control program comprises a synchronous control system based on the characteristics derived by the numerical analysis, and it is designed using a conditional equation to ensure stability. A tank test is conducted to verify the usefulness of the control program and the suggested method to ensure berthing stability.