A Study on the Optimal Tracking Control System Design for Automatic Ship Berthing

In this study, a control system design method for realizing automatic ship berthing in the harbour area is considered. In general, the control system for berthing have been issued as a simple root tracking problem without complex harbour environment. The harbour is crowded with many ships such that the berthing root to the quay side is too complex and not easy to approach there. Therefore, in this study, the authors set the berthing root to two approaching modes which are defined as the ballistic and final phase. In the ballastic mode, the vessel moves using all actuators. And in the final mode, the vessel uses two side thrusters for keeping it in parallel moving. For obtaining good root tracking performance without tracking error in the steady state, a servo-system with an integrator is designed based on LMI approach. Simulation results using a vessel model are given such that the specified control performance is verified.