Presentation of AIS Target Data on a Visualization-based Collision Avoidance Support System for High Speed Craft Operating in Congested Waterways

摘要

A visualization-based collision avoidance support system (VCASS) that is particularly designed for high-speed craft (HSC) operating in congested waterways has been developed. VCASS focuses on visually presenting the collision risk of multiple targets and selection of feasible evasive manoeuvres by judging the tip of own ship's velocity vector in relation to cone-shaped collision danger regions to acquired targets in true motion. The key input parameters required are the position and velocity vectors of targets and own ship's motion parameters. The target size is important information to the HSC navigator when considering collision risk and amount of evasive action necessary in order to pass with a minimum safe distance margin. Exact information of ship dimensions is broadcast by the ship borne Automatic Identification System (AIS), which is a key source for supplying vital information to own ship of surrounding ship traffic as a supplement to radar based target detection. The primary target data input to VCASS is suggested to be AiS with radar data as the secondary source. The collision danger regions to acquired targets are displayed according to a target selection procedure that is based on user-selected DCPA and TCPA limits as well as the speed surplus compared to surrounding sea traffic. VCASS with AIS target data inputs is capable of supporting early decision-making of complicated and congested traffic situations and therefore enables course-evasive manoeuvres to be made by the HSC navigator well in advance of a developing situation.