THE EFFECT OF HYDRO-METEOROLOGY ON SHIP COLLISION AVOIDANCE IN HEAVY TRAFFIC AREAS WITH A SIMPLIFIED SIMULATION MODEL

Abstract

On the basis of the ship collision avoidance steering system in calm water developed by the authors, this paper upgrades the numerical simulation model by considering various hydro meteorological factors for ships with nonuniform movement. A real-time simulator was used for the numerical simulation of the container ship. To clarify the validity of the maneuvering mathematical model, sea trial results for the container ship were compared with the results for the present simulation system in terms of turn trajectory. In this study, a numerical technique based on Nomoto's second-order model was employed to investigate the turning characteristics of a container ship. The maneuvering indices were obtained from numerical simulations using the Newton-Raphson method and a regression technique. Both simple and complex collision avoidance cases were selected to verify the proposed ship collision avoidance system with respect to different hydrometeorological conditions; the results were then compared with those of the ship collision avoidance steering system in calm water. This simplified maneuvering model, based on the database of maneuvering parameters, was extremely effective in finding the helm angle for ship collision avoidance in heavy traffic areas. Under adverse hydrometeorological conditions, maneuvering a ship for collision avoidance is more difficult than under calm water conditions because the safety distance is closer when a larger rudder angle is required.