Research Of Intelligent Vehicle Navigation System Integrated GPS/GIS/GPRS

With the development of automobile industry, the car ownership has a great growth in our country, meanwhile it also brings the problem of traffic congestion. Traffic information is the most important information for driver, and based on current traffic information, driver can effectively avoid the traffic jam sections. But the traditional vehicle navigation system is a single individual, it can not reflect the real-time traffic information to the electronic map, and it can not avoid the congested road automatically based on the real-time traffic information. To solve this problem, the paper put forward a scheme of intelligent vehicle navigation system that integrated Global Positioning System(GPS),Geographical Information System(GIS) and General Packet Radio Service (GPRS).First the paper analyzes the system structure and working principle of GPS,GIS and GPRS, describe the hardware and software design of vehicle terminal in detail. The vehicle terminal as an embedded GIS system is divided four layer, and they are hardware layer, bootloader layer, operating system layer and software layer. Hardware layer introduces the working principle and advantages of the ARM development board, GPS receiver and GPRS data transmission unit. Bootloader layer introduces the driver U-boot and its advantages. Operating system layer introduces the operating system Windows CE. Software layer introduces the software development model of the vehicle terminal system, and achieve the key function that include pan and zoom electronic map, location query, shortest path search and exchange information between vehicle terminal and information centers.Second, the paper decribes the system structure of information center, the information center is composed by electronic map operations management module, the database operations module and information module. And the paper introduces the key technologies in each module. They include that modifications of the traffic information, the method of electronic map echo, the method of connection to the database and update database and the method of communication between vehicle terminal to information center.Finally the paper put forward a Dijkstra shortest path algorithm based on minimum heap, and it introduces the data structures and realization of the algorithm, and it tested the algorithm by using five sets of data. The results show that the algorithm is able to search of the shortest path completely and it is better than other shortest algorithm in the efficiency.