On the use of AIS binary messages for exchanging navigational intentions in encounter situation

摘要

This paper proposes a Navigational Intention Exchange Support System (NIESS) using AIS binary message. Usually, assessing collision risks, decision making for taking collision avoidance actions and planning the avoidance manoeuvre are carried out based on an Officer of the Watch's predicted behaviour of encountered ships. Therefore, unexpected change of encountered ship's manoeuvre or improper prediction may cause near misses and collisions. Actually, many seafarers demand to have clear information of encountered ship's navigational intention such as "Passing down Port to Port". VHF voice communication is effective way for exchanging such information. Actually, Automatic Identification System (AIS) increases VHF voice communication because the AIS function for identify target ship's name makes it easy to point a target ship for calling.[1] However, VHF voice communication still has shortcomings such as linguistic barriers and misunderstanding of voice messages. To overcome the shortcomings, information exchange system using internationally agreed coded data is useful. To realize effective navigational intention exchange, a communication system based on AIS binary message is designed called Navigational Intention Exchange Support System (NIESS). The NIESS is a software for handling AIS binary messages and for a user interface which displays exchanging information on RADAR screen and which arrows to send demanded information. The information is exchanged between ships with each ship's NIESS. This paper illustrates the concept of NIESS, the way and contents of information exchange by AIS binary message and future prospects for the NIESS.