| 1.IntroductionWith the need of road and traffic and the development of modern high technology, Intelligent Transportation Monitor System (ITMS) is widely applied as a new generation of traffic system. ITMS integrates advanced information technology, transmission technology of data communication, electronic sensing technology, electronic control technology and computer network and information processing technology, and applies to traffic management system, and establishes an effective, real-time, exact and efficient transportation management system. ITMS is researched and developed to establish the relation of road, vehicle, driver and supervisor and make the supervisor and driver master the vehicle condition. The traffic automation and intelligent vehicle are achieved to alleviate the road congestion, to promote transportation efficiency and vehicle security, to obtain fast, punctual, convenient and comfortable public transportation.Control center of the traffic is the key technology of ITMS. which exchanges information between vehicle and intelligent control center to make the users know the road condition and traffic flux, to offer multimedia information (e.g. text, picture, video and audio) to the users and remind the users. The structure plan is different among the navigation system, in general the navigation system comprises of on-vehicle, wireless system and supervising system of ground center (short for base system).2. Major content of the thesisBecause of various kinds of relations, control center of the traffic in this text is the administrative system of the command center on the ground monitors in fact. The system comprises of on-vehicle computer, GPS receiver and others. The process of System of control center is as follows: Car-mounted GPS terminal station is distributed in each moving at the vehicle, which receives GPS satellite fix message to responsible for, and in a situation that the control center demands to send back to the data, through the data controller it can solve the position coordinate of the vehicle place, the coordinate data passes wireless MODEM (GSM module ) which accords with GSM standard after dealing with, utilizing the form of short information to send the information , such as position , state , serial number of the vehicle ,etc. to GSM common network , GSM common network conveys the receive message of orient vehicle to the receiver of the control center. The geographical information system with the computer system matches after processing of computer system and serial mouth in the control center, and the computer comes out on real-time. On the other hand, each road test center sends the traffic of each highway section to GSM network through certain way of encoding too, and is showed in the computer system of the control center, it makes the control center alleviate the traffic pressure according to the dispatcher of the traffic jam of each highway section with real-time state vehicle. In addition , the systematic computer of control center needs to utilize communication module to carry on wireless communication, which returns condition information and receiver control information. The above is the hardware of on-vehicle system, in auto-navigation system the hardware is not complex, so the main task is the software.The whole system software comprises of mobile vehicle location and GIS, in which the former is made up of optimizing road network, receiving and processing GPS data, transforming coordinate, location and correction of vehicle location; the later is made up of making electronic map, the scan and scale of electronic map, location of various objects, drawing distribution picture, the select of bus plan, the management of database and help information. During the process of the vehicle going, through receiving and dealing with GPS data from satellite(for example, longitude, latitude, speed, time, direction, etc.) it conveys to the control center of the traffic. Then traffic monitoring system makes a reservation on electronic map (e.g. Electronic map of...
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