A Method for Automatic Collision Avoidance in Confined Waters

With the increasing complexity of maritime traffic, new approaches are needed to support navigators with additional technical systems and automatic functions to ensure safe navigation. This paper presents a method for optimal, automatic collision avoidance maneuvers in confined waters, such as in ports. Three automatically operating vehicles are involved in the cooperative scenario, which reflects typical encounter situations near port structures, head-on and crossing. The individual initial trajectories of the vessels would lead to collisions. To prevent collisions, a central guidance system calculates avoidance trajectories with defined minimum distances to each other. The centralized approach is based on the solution of an optimal control problem that allows the total energy consumption for the maneuvers of the three vehicles to be minimized. The paper describes the scenario design to test automatic maneuvering in ports with crewed vessels in a nautically valid manner. The optimization method, including its constraints, is explained in detail and simulation results are presented.