A Hybrid A*-APF Path Planning Method for Ships Entering the Berthing Waters

Abstract

Ship berthing is a critical and high-risk phase of navigation that requires highly precise path planning in environments with numerous obstacles. This paper presents a two-stage hybrid path planning approach designed to improve both safety and manoeuvrability during berthing operations. The first stage involves constructing an accurate environmental model based on berth characteristics. In the second stage, an enhanced A* algorithm is introduced with a directional consistency penalty to generate globally feasible paths with improved continuity. To further enhance local obstacle avoidan ce and edge-following capabilities, the artificial potential field method is applied. The resulting path is coupled with a ship dynamics model and a dynamic look-ahead strategy combined with PID control is employed to enable closed-loop heading and speed tracking. Simulation results show that the proposed method significantly enhances path smoothness and obstacle clearance. Specifically, the average heading change is reduced to 2.51° and the minimum obstacle distance increases from 15.12 to 39.04 m. This approach offers a practical and effective solution for autonomous berthing in constrained port environments.