Automatic collision avoidance algorithm based on route-plan-guided artificial potential field method

Abstract

With respect to navigation practices and real-ship applications, this study provided a stable and reliable technical program for automatic ship navigation. First, an improved route-plan-guided artificial potential field (APF) method was presented by balancing the attractive and repulsive forces, resolving the irrationality and swaying of the collision avoidance (CA) strategy, and extending the applicability of the International Regulations for Preventing Collisions at Sea (COLREGS). Second, a fast local path planning (FLPP) method was proposed based on the high-precision ship motion model to obtain the expected CA results in advance, and to promote its acceptance and application by the navigators. Third, a dynamic goal-guided APF method was proposed to navigate a ship to return to its route plan upon completing the CA procedure. A series of CA experiments for different ships and encountering situations were conduct in a simulated environment. Although the varying maneuverability influenced the CA procedure and results, the CA processes and trends were identical, and the track zone width was within 0.10 nm in restricted waters. The real-time CA track sufficiently aligned with the FLPP results, and the ship was able to rapidly return to its route plan and remained within the cross track limit (XTL) according to the set return parameters.