Adaptive modeling of a ship trajectory in collision situations atsea

摘要

For given circumstances (i.e., a collision situation at sea), adecision support system should help the operator to choose a propermanoeuvre, teach him/her good habits, and enhance his/her generalintuition on how to behave in similar situations in the future. Bytaking into account certain boundaries of the manoeuvring region, alongwith information on navigation obstacles and other moving ships, theproblem of avoiding collisions at sea is reduced to a dynamicoptimization task with static and dynamic constraints. A modifiedversion of the EP/N (Evolutionary Planner/Navigator) has been used as amajor component of a such decision support system. ϑEP/N++computes a safe-optimum path of a ship in a given static and dynamicenvironment; on the basis of this algorithm, a safe trajectory of theship in a collision situation is determined. The introduction of a timeparameter, together with time-varying constraints representing movableships, are the main features of the new system. Sample results of shiptrajectories obtained for typical navigation situations are presented inthe paper