A Multi-Threat Avoidance Maneuver Generator

Collision avoidance systems have grown in importance with the increases in both traffic density and vessel size. The main requirements on the avoidance maneuvers are that they: (1) be consistent with the rules; (2) account for ship maneuvering limitations; (3) include a return-to- original-course trajectory; and (4) take into account errors introduced by the sensors and other operating/procedural factors. A candidate multi-threat avoidance maneuver generator was formulated, implemented on a real- time processor, and validated for various ship encounter geometries with up to five ships. The maneuver generator provides the simplest possible avoidance trajectory, for each of the encountering ships, consisting of up to five turn and straight segments. A four-ship encounter scenario illustrates the effectiveness of the algorithm. This maneuver generator can be used to aid ships in avoiding collisions in a timely manner. However, further shipboard tests remain to be performed prior to the widespread operational deployment of collision avoidance systems with this capability.