A Role-based Multi-agent Model for Concurrent Navigation Systems

1. INTRODUCTION Since the eighties constant augmentation of the demand on worldwide maritime transportation together with acute economical competition have increased the pressure on ship owners and commercial fleets. Crews are often reduced to a minimum and sometimes to even one officer of the watch in the deck. In order to counterbalance these negative effects on safety navigation, and to facilitate the task of navigation officers, a new generation of automated-navigation systems has appeared over the past years. Those include the Automatic Radar Plotting Aids (ARPA) [1], Automatic Identification System (AIS) [2] and Electronic Charts Display Information System [3]. The ARPA is currently one of the most frequently implemented systems for automatic navigation. It is based on a radar system that makes tracking of ships possible, and derives important navigation information such as the Closest Point of Approach (i.e. minimal distance that separates two ships whose routes are crossing) and the Time to Closest Point of approach (TCPA). The AIS is a communication system that allows exchange of navigation data between ships and navigation authorities (one VHF transmitter, two VHF Time Division Multiple Access receivers and one VHF Digital Selective Calling receiver). It is a solution comparable to aeronautic transponders. The ECDIS is an electronic mapping tool that includes GPS information, navigation tools, route planning and warning functionalities. It can also integrate ARPA and AIS data. These automated navigation systems are part of the resources used by an officer of the watch, contributing thus to safe navigation. Further work in the development of