Geometric Path Planning for High Speed Marine Craft

We propose a new geometric algorithm for path planning of maritime vehicles, which partially meets the Convention on the International Regulations (COLREGs) for preventing collisions at sea. To carry out risk assessment with obstacles, one of the decision variables used is the intersection of the Line-of-Sight (LOS) with the obstacle's position. For dynamic obstacles, that position is based on the projection of the obstacle moving forward in time assuming a constant speed and heading. Following a positive risk of collision, a (starboard or portside) manoeuvre is applied. The algorithm is designed to adhere to COLREGs steering rules automatically, in particular, rules 13-16. Unlike using a binary decision variable for risk assessment, which is a common method of choice in the literature, the proposed approach utilises a fuzzy risk index to determine the level of collision risk, minimising the occurrence of false positives. The computational complexity of the proposed algorithm is relatively low making it appealing for real-time implementation. We report encouraging results via simulation analysis for a range of scenarios involving both static and dynamic obstacles.