A Guidance and Maneuvering Control System Design with Anti-collision Using Stream Functions with Vortex Flows for Autonomous Marine Vessels

TL;DR

This paper introduces a novel guidance and maneuvering control system for autonomous marine vessels using stream functions with vortex flows, enabling effective collision avoidance in complex, dynamic environments while adhering to maritime safety regulations.

Contribution

It extends static flow-based guidance methods to dynamic environments by incorporating vortex flows and recursive stream function updates for real-time waypoint decisions.

Findings

Successfully avoids collisions in simulated dense marine traffic

Handles complex dynamic obstacles with simple, tunable flow models

Produces smooth, feasible vessel paths considering ship dynamics

Abstract

Autonomous marine vessels are expected to avoid inter-vessel collisions and comply with the international regulations for safe voyages. This paper presents a stepwise path planning method using stream functions. The dynamic flow of fluids is used as a guidance model, where the collision avoidance in static environments is achieved by applying the circular theorem in the sink flow. We extend this method to dynamic environments by adding vortex flows in the flow field. The stream function is recursively updated to enable on the fly waypoint decisions. The vessel avoids collisions and also complies with several rules of the Convention on the International Regulations for Preventing Collisions at Sea. The method is conceptually and computationally simple and convenient to tune, and yet versatile to handle complex and dense marine traffic with multiple dynamic obstacles. The ship dynamics are taken into account, by using B\'{e}zier curves to generate a sufficiently smooth path with feasible curvature. Numerical simulations are conducted to verify the proposed method.