Collision risk assessment for large LNG ship entering port

Due to the inherently hazardous nature of liquefied natural gas (LNG), preventing collision involving LNG ship is crucial for ensuring navigation safety. This paper considers LNG ship as own ship and employs the Nonlinear Velocity Obstacle (NLVO) algorithm to assess the collision risk during entering port. The evaluation metrics utilized in this study include the ship domain and safety zone, which serve as indicators of collision risk. In contrast to traditional methods, NLVO accommodates nonlinear velocity and course variations of target ship. A scenario has been designed to illustrate the efficacy of the NLVO algorithm, with results indicating that this approach can effectively evaluate collision risk and provide actionable decisions for pilots.