On a Computer Aided Maneuvering System in Harbours

In the present report, an attempt is done to develop a computer aided maneuvering system in harbours. The system contains two functions. The first is to make a plan to lead a ship to a berth and the second is to carry out the plan. To make the plan, an approaching pattern is selected and it is built up as a combination of elemental maneuvering patterns. The trajectory from the initial state to the final one is designed.To assure maneuvering safety, following two concepts are employed ; a false goal and margins of control forces. The first means that a ship approaches to the false goal placed in front of a berth, instead of approaching to the real one. The latter is to design the trajectory with enough margins of control forces.To lead a ship to the berth, both of feedback and feedforward controls are utilized along the designed trajectory. A simplified mathematical model of maneuvering motions are used to determine control forces. The control forces are supplied in quantized forms by tugs.A simulation result is finally reported to show a successful approach along the idea proposed in the present study.