BASIC RESEARCH ON AN EXPERT SYSTEM FOR NAVIGATION AT SEA - COLLISION AVOIDANCE EXPERT SYSTEM

This report is concerned with an expert system for collision avoidance, as one subsystem of an expert system for navigation at sea, while an expert system for coping with collision accident was developed as one of the subsystems in 1986. In this report, the authors have dealt with the collision avoidance facility in order to generalise the system. The purpose of this system is to provide a captain or a navigator with consultative advice to avoid collision. Two methods to represent the risk level of collision are used; i)the method by the rule-of-thumb and the rule of the Regulations for Preventing Collision at Sea, and ii)the method using the value of TCPA and DCPA. The results of experimental simulations of this system are summarised as follows. 1) Actions shown by this system to avoid collision agreed approximately with the rule-of-thumb; and 2) The time required for one series of inference and display is about 20 seconds per one target.