Experiments in on-line mode trajectory planning at sea by evolutionary algorithm

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 in those cases is a multiple criterion decision problem. In the chapter a new version of the vEP/N++ (Evolutionary Planner/Navigator) [17] algorithm with on-line mode has been used as a major component of such a decision support system for computing the near optimum trajectory of a ship in a 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 has been reduced to a dynamic optirnisation task with static and dynamic constraints. The introduction of a time parameter and moving constraints representing passing ships, as well as the online mode are the main distinguishing features of the new system. The results having the form of ship trajectories obtained using the program for typical navigation situations are given.