Modelling and Simulation of Sea Traffic and a Visualization-based Collision Avoidance Support System

Safety of vessel transit in congested sea areas such as busy ports and coastal waters is a key issue for navigation officers and traffic operators. With performance improvement of observation devices and introduction of new information systems, vessel traffic service is expected to play a larger role in supporting the officers onboard. Increase in amount of available information demands higher ability of critical situation awareness and operational decision-making in complex situations. Computer support for these tasks is of the highest importance. However, the development and evaluation of support systems for marine traffic is challenging since existing ship manoeuvring simulators do not present rich scenarios involving interesting situations occurring in appropriate ambient traffic. In this paper, the work on a sea borne traffic model in the sea traffic simulation system SEATRAS and a visual support system for management of critical traffic situations has been reported. An algorithm to generate traffic flow from observation data and ship motion model has been developed to represent the movements of the vessels in congested areas. Visualization-based Collision Avoidance Support System (VCASS) calculates and displays the information of collision risks based on traffic flow data, which is shared with the simulation system using local area network. A case study of an actual collision incident in Tokyo Bay has been simulated to illustrate the capability of the proposed systems.