Collision avoidance maneuver planning based on adaptive ship domain

In classical navigation, calculations of key parameters are performed through vector operations relative to points or circles. This approach does not adequately account for the dynamic characteristics of targets and therefore increases the risk of accidents. To improve navigational safety, the use of an adaptive navigation safety zone is proposed, formed by groups of foci that incorporate both the invariant characteristics of own ship, such as its dimensions, and dynamic parameters arising from current conditions. Correct assessment of hazards around a ship employing an adaptive navigation safety zone, which represents a complex closed curve, requires a revision of standard computational algorithms used to assess navigational safety and perform collision avoidance maneuvers. This paper proposes a method for determining whether a target lies outside or inside such a boundary and for forming a speed maneuver using a compression ratio coefficient when the target is located within the safety zone. The tasks of calculating the current and predicted (recommended) lines of relative motion are addressed in order to predict target movement and provide the operator or system with new courses for taking action to avoid collision in ample time or, when the target is already within the safety zone, for performing a maneuver to eliminate the hazard. The task of calculating the distance from the boundary to the target is also addressed. The proposed methods and mathematical models have been validated by computer simulation and have demonstrated positive results in terms of both safety and optimization, allowing the system to be integrated on board modern ships.