A study of decomposition of a group of ships for preliminary forecasting of dangerous approaching

Abstract

The conducted studies of emerging situations of dangerous approaching of several ships revealed the existence of classification of ships that are target ships relative to the base ship. These target ships can be dangerous, safe, safe but dangerous under certain conditions. In turn, dangerous that require the maneuver of standard collision avoidance, as well as the targets that require the maneuver of emergency collision avoidance. It is proved that the specified classification of ships can be carried out using the belonging of target ships to different subsets, which depend on their motion parameters relative to the base ship.This made it possible to view a group of several ships as a set of targets.Experimental studies using computer simulations confirmed that decomposition of the ship approaching situation into subsets, each of which is different from the other in relative motion parameters, is possible. These parameters are relative course, bearing, maximum allowable closest point of approach for normal and emergency maneuvering, time until reaching the closest point of approach. The speed ratio between of the base and target ships, the ratio of the closest point of approach and the maximum allowable distance also affect the belonging to a certain subset.This suggests that there is a clear dependence of the collision probability of ships on their belonging to different subsets, which can be calculated for each ship participating in the collision avoidance maneuver. It is shown that when the base ship performs the collision avoidance maneuver, there are changes in relative motion parameters, and hence the belonging of surrounding target ships to different subsets.Thus, there are grounds to argue that using the specified classification of target ships, preliminary forecasted belonging of ships to different subsets can be calculated. The probability of dangerous approaching and/or collision of ships can also be calculated for each course alternation of the base ship relative to each of the surrounding target ships.