Ships Based On Ais Collision Avoidance System Applied Research

Automatic identification system (AIS) provides a new means of collision avoidance for ships by utilizing its advanced communication method with high accurate information, which includes much information available for collision avoidance. The AIS is expected to play more and more important role in the safety of navigation. With the compulsory implementation of AIS and being widely equipped onboard ship, the collision avoidance system based AIS technology (named AACS- AIS Anti-collision system hereafter) is a promising technology for safety navigation.The paper covers mainly the following aspects of AACS technology:Coming up with the considerations on the application of ship-borne AIS based on the collection and analysis of research essays published domestically and internationally, and the considerations on the features and characteristics of collision avoidance. Conducting researches by dividing AACS into three types, i.e, ship-borne AIS, shore-borne (installations at VTS center) and portable AIS for pilot's use. Designing basic AACS framework according to international standard, and explaining detailedly each part of the AACS.Giving out in-depth researches and discussions for the data-processing of AACS, providing the system state equation, KALMAN filter equation and filter's calculate flow, and coming up with the methods to avoid filter's volatilization in the paper. Researching on the acquisition and processing method of basic navigation data such as ship's position, course, speed, time, CPA and TCPA. Designing AACS' hardware framework with DSP, CPLD, Flash, special keyboard, LCD monitor and peripheral circuits in the paper, which give the AACS the standard communication interface and good human-machine interface. Programming the AACS's software . including DSP'S program under Tl' sCCS environment, CPLD's logic program under MAX + PLUS II environment, system program under visual C ++ and so on.In the practices, AACS can judge the existence of risk of collision by receiving AIS simulated signals. If such a risk does exist, the AACS then acknowledges it, gives out alarming signals and transmits them through the AIS. Experimentation has proved AACS has the advantages such as fast responding to risks, easy operation, low price, which make it a promising technology in securing a safer shipping.