Collision avoidance at sea

Abstract

The problem of collision avoidance between surface ships may be examined from the perspective of either macro or micro collision avoidance. In macro collision avoidance the pilot of a ship would try for maintaining a given mileage separation between his own ship and others. Micro collision avoidance would be concerned with manoeuvres between ships of less than a given separation distance. Analysis of the two situations is different. In macro collision avoidance the other ships would often be maintaining constant speed and heading. Attention would be focused on keeping other ships out of an appropriate circle about the center of ones own ship. In micro collision avoidance other ships would in general be manoeuvering. The actual shape of the ships may be important in determining appropriate manoeuvers for own ship. In both macro and micro collision avoidance, qualitative game/control theory is useful for the determination of critical barriers and manoeuvre Results obtained this way for two ships are compared with some collision avoidance guidelines in actual use.