An intelligent method of ship's trajectory planning at sea

In a navigation situation at sea, the decision support system should help the operator to choose a proper manoeuvre in given circumstances, teach him good habits, and enhance his general intuition on how to behave in similar situations in future. An accepted approach in those cases is a multiple criterion decision problem. In the paper a modified version of the evolutionary planner /navigator algorithm, has been used as a major component of such a decision support system for computing the near optimum trajectory of a ship in given environment. By taking into account certain boundaries of the manoeuvring region, along with navigation obstacles and other moving ships, the problem of avoiding collisions at sea was reduced to a dynamic optimisation task with static and dynamic constraints. The introduction of a time parameter and moving constraints representing passing ships is the main distinction of the new system. Sample results, having the form of ship trajectories obtained using the program for typical navigation situations are given.