A method for establishing a ship safety domain oriented to collision risk judgment

Ship Domain (SD) is an important concept for the navigational safety of ships that can be used to determine the risk of ship collision. In this paper, we propose a method to establish a Ship Safety Domain Oriented to Collision Risk Judgment (CRSD), which considers the quantified collision risk in the process of establishing the ship domain, therefore the CRSD model is more suitable for risk judgment. Firstly, Automatic Identification System (AIS) data of paired ships are analyzed through using the ship collision risk detection model, and the cases with high collision risk are counted. Then, considering the relationship between ship domain and ship's length, the selected cases are classified according to the ship's length of Own Ship (OS), and the angle when OS encounters with Target Ship (TS) is quantified to get the relationship between the radius of the ship domain and ship's length at different angles so that the shape of CRSD can be obtained. Finally, the CRSD is analyzed and the results show that the CRSD model is consistent with the International Regulations for Preventing Collisions at Sea (COLREGs) that is suitable to be applied to ship collision avoidance risk judgment.