On-Line Trajectory Planning in Collision Situations at Sea by Evolutionary Computation-Experiments

Abstract

In a collision situation at sea, the decision support system should help the operator to choose a proper manoeuvre in a given navigational situation, teach him good habits, and enhance his general intuition on how to behave in similar situations in the future. An accepted approach here is the use of a multiple criterion decision problem based system. A new version of the υEP/N++ (Evolutionary Planner /Navigator) algorithm equipped with an on - line mode has been used, as a major component of such a system, for computing the near optimum trajectory of a ship in given environment. Taking into account existing boundaries of the manoeuvring region, navigational obstacles, and moving strange ships, the problem of avoiding collisions at sea was reduced to a dynamic optimisation task with static and dynamic constrains. The introduction of the time parameter, moving constrains representingapproaching ships, and the on-line mode are the main distinctions of the newly introduced system. The paper presents selected results in the form of ship trajectories obtained for typical navigation situations.