【作者】 石向亭；

【导师】 陈思国；

【作者基本信息】 吉林大学 ， 计算机应用技术， 2011， 硕士

【摘要】 随着通讯技术的发展和地理信息系统技术的广泛应用,使得可以缓解城市交通问题的中心导航系统成为导航系统研究的热点。中心导航系统与以往自主导航系统最大的不同点是,原有导航系统根据静态的地理信息为用户进行导航,中心导航系统则是既考虑路网信息,又根据道路状况,为用户进行实时、准确的导航；同时导航终端系统地图数据通过服务器下载,终端不存储电子地图数据和复杂智能交通系统应用,通过车载终端与导航中心的数据交换协议进行数据交互,车载导航终端将成为一个纯粹的人机接口(HMI, Human Machine Interface),从而极大地降低其设计和实现复杂度。本文设计了基于IPv6的车载中心导航仪,对中心导航仪的三个重要模块进行详细介绍。首先介绍了地图匹配模块,地图匹配其所需的路网数据通过无线网络从导航中心的服务器下载,设计了基于对路网分块的方法路网数据预取和更新策略,实现地图匹配功能；同时介绍了导航诱导模块,该模块实现通过网络下载局部放大数据和路径规划数据,进行导航功能；地图显示功能是导航系统的重要功能,为了保障地图显示的实时性,选择使用地图图形数据分块存储和地图显示二级缓存的方法来提高地图传输和显示效率,实现了地图实时显示性。更多还原

【Abstract】 With the rapid development of Chinese economy, the congestion of urban traffic has been brought into focus among people. The development of communication technology and the widely use of geographical information systems technology, Central navigation system has been brought into focus among the navigation, because it can relieve urban traffic congestion. The most difference between central navigation system and autonomous navigation system is that center navigation system provides real time and accurate navigation, according to road network information and road conditions. At the same time the navigation terminal system download map data through network from map data server, the terminal does not store the electronic map data and the complexity application of intelligent transportation systems. Only defines the center vehicle terminal and the navigation data exchange protocol, car navigation terminal will be a purely man-machine interface (HMI, Human Machine Interface), which greatly reduces the complexity of the design and implementation. Also, this design philosophy and the social development of China’s current high-speed, fast network and roadside POI (Point of Interest) fit with the update, but if not handled properly on the center of the network delay will cause a lot of the effect of navigation.This paper studied central navigation terminal system based on IPv6 not only provides navigation services and information services, but it also can provide remote diagnose and repair function through the wireless network. Navigation system terminal map data download from the server, The Center navigation system needs to solve the biggest problem is that how ensure the terminal system get the map data in real time. This navigation device solves well the navigation effect of network transmission.First, this paper designed and implemented a map matching module, the necessary road network data is downloaded through the wireless network server in real time from the navigation center server. Designed road network data pre-fetch and update policies during network transmission based on the map block. The vehicle experiment test the feasibility of real-time map-matching downloading data service from a central network through the wireless network. Second, this map designed and implemented the navigation guide function, it downloads data (local amplification data and path planning data) by the network, guide user according to real-time traffic, provide user road path planning function. Third, this paper designed and implemented the map display function is an important function, in order to ensure the real-time map display, chooses to use the map block storage and the secondary cache data to improve transfer and display map graphic efficiency. It design navigation center server and the terminal graphical data communication protocol and the terminal store graphics data structure, the system achieves effective e-map data which includes real-time navigation information transmission between the terminal and the server. To meet the ream-time demand of the e-map updating in the terminal, it put forward an online e-map data pre-fetch and updating strategy. Simulation and test-bed test both show that the system can achieve good online and real-time e-map distribution by using CDMA.更多还原