The modified artificial potential fields method in collision situations at sea

This paper proposes a modified artificial potential fields (APF) method for collision avoidance at sea. The concept of artificial potentials used herein is derived from fields generated by electric charges. Attractive and repulsive forces are determined, accounting for the positions of an own vessel and a target vessel. The own vessel and its goal are considered as opposite charges. There is an attractive force between them, while the own vessel and target vessels or obstacles are considered as charges with a repulsive force between them. The values of these forces depend on the coefficients of attraction and repulsion. To solve a particular collision situation, the modified method of artificial potential fields is used. Due to the specific nature of the vessels’ movement, additional factors affecting the values of the attraction and repulsive forces are considered, as opposed to solutions used for robots. The main purpose of this article is to present the method for determining the coefficients of the APF method. This method will be used to avoid collisions at sea. From an analysis of factors influencing the execution of the vessel maneuver in a collision situation, a modified method for determining the attraction and repulsion coefficients is proposed. A case study of collision avoidance in a vessel encounter situation is also conducted.