Based On Ais / Ecdis, Maritime Collision Avoidance Research

Making a comprehensive survey of the developing shipping technology history, Human error is the man course of collision accidents at sea.There are mainly two ways to increase the safety of the vessels' navigating in the sea recently: one is depending on the vessel traffic service when ships arrive at harbors; the other one is depending on the rules of vessel collision when ships navigating in the sea. Radar is regarded as the mainly observation equipment of the two approaches which used to supervise and identify ships. Although the function of radar keeping on being improved, its disadvantages are still exist. With the rapid developing of technology of communication and computers, AIS is born to live and will be stronger and stronger.The main application field of AIS is the vessel collision and vessel traffic service, AIS has provided the unprecedented vessels tag information and high real time and accurate parameter of ships navigating. It can provide more information, better real time and stronger anit-jamming than radar, also it has other virtues such as transmitting over obstacles. In a word, AIS can bring the revolutionary progress to the supervision of the vessels navigating in the sea.The main function of the electronic chart display and information system(ECDIS) promotes the navigation security, it not only displays the electronic nautical chart on the computer, more over also is real-time navigation monitoring and the display system integrated each kind of correlated navigation information for the officers, it will to enhance the technology of navigation to a brand-new altitude. Because ECDIS is foundation and processes the platform of each kind of information, it provides the first floor on the support for the navigation automatic. Because all information needed can be obtained on the monitor, officers can grasp the situation through ECDIS comprehensively which the ships locates, sot the officers may not need to examine the nautical chart, the radar, GPS, the meteorological facsimile chart separately and so on, only needs the pilot to coordinate and to process each kind of unusual situation. ECDIS already was the paper nautical chart simple substitute not merely, it hasbecome core of all navigations information.The improvement of automatic collision system is the key of reducinghuman error and increasing navigation safety.This dissertation focuses on the researching in the foundation of AIS/ ECDIS integration.1 . The use the ship's position, the heading information which obtained from AIS and this ship GPS, calculates out the basic parameter of avoidence collsion: D, TB, DCPAand TCPA;2, in ship's encountering, the estimation for the collision risk index from the coming vessel is the foundation to adopt suitable measure. The paper applies the judge model of math, uses DCPA, TAPA, of the coming ship as the evaluation norm, and draws into the subordinate function of criticality which is composed of the relative shun field to judge the criticality of the ship's encountering objectively and effectively and provide the reasonable basis for ship's safe collision avoidance.3, After obtaining the decision-making basis of CRI, produces the new course made good through the mathematical model which the ships should change drives to, again produces the best compass course for avoiding collision through the computation.