A Study on Strategic Collision Avoidance Based on Planned Route and Navigational Information Transmitted by AIS

Abstract

After AIS (Automatic Identification System) was introduced into marine traffic, there are many researches to make it useful for marine traffic management and safe navigation. However, navigators do not usually use all functions of AIS because of its inconvenient display and complicated data inputting. In order to improve the safety and efficiency of ship operations, PTMS (Port Traffic Management System) has been developed from 2001. In this study, the optimal route is calculated based on the information of planned routes and speeds of target ships transmitted by AIS using Dynamic Programming. As the results of simulations, it was found that in a congested waters with dangerous crossing encounters, if only altering course of own ship is not sufficient for safe and efficient navigation, reducing speed of own ship is effective to shorten passage time and also navigate safely. Furthermore, in order to confirm the effectiveness of the optimal route, data of vessel traffic obtained from radar observation of Tokyo Bay and AIS actual data received from AIS of training ship "Shioji Maru" were used to carry out some simulations. From the results, it was found that in the congested waters such as the north of Naka-no-Se Traffic Route and the south of Uraga Suido Traffic Route, it is very beneficial to decide a safe and fast route if own ship knows other ships' planned routes and speed information.