Vector Field-Based Guidance Method for Collision Avoidance of Unmanned Surface Vehicles

Autonomous vessels have become a popular research topic. This work extends the study of the ship simulator and develops a vector field-based guidance method for collision avoidance when a ship is proceeding to the arrival port. Vector field-based guidance method integrates a risk factor when pilots lead large ships into a port and follow specific guidelines to avoid colliding with shorelines. An area near the port is a vector field to guide the ship into the harbor. This vector field consists of a straight-line vector field and a circular vector field to form unified commands to steer the ship. During the berthing, the vessel follows the vector field for guiding into the pier, or if there is an obstacle, a risk index will be calculated to perform avoidance. The feasibility of this work is verified by implementing the vector field guidance method into a ship simulator developed by Ship and Ocean Industries R&D Center. This ship simulator involves wind, wave, and current influences on ship motions. The simulation combines the vector field-based guidance method and the risk index in a ship simulator. The results show that it is promising to guide port entry safely in a crowded harbor in various situations.