【作者】 刘峰；

【导师】 文远保； 陈晓苏；

【作者基本信息】 华中科技大学 ， 计算机系统结构， 2007， 硕士

【摘要】 车辆监控系统是智能交通系统的一部分,其基本功能是车辆实时定位与状态监控。传统的基于客户/服务器C/S(Clint/Server)结构的车辆监控系统存在着用户无法快捷方便地获取信息,可扩展性差,系统建设与维护成本高等弊端。因此实现基于浏览器/服务器B/S(Brower/Server)结构的车辆监控系统已经成为目前研究的热点。通过对网络GIS(Geographic Information System)、Ajax(Asynchronous JavaScript and Extensible Markup Language)和GIS Web Services等关键技术的研究与分析,针对当前B/S结构的车辆监控系统中由于安装插件扩充浏览器功能而带来的系统安全性差、客户端部署复杂等问题,结合实际应用需求,采用Ajax和GIS Web Services相结合的模式设计并实现了一种基于B/S结构的车辆监控系统。阐述了系统的工作原理、体系结构及主要功能,详细设计了系统的数据库及实时监控、轨迹回放、路径规划、地图匹配、坐标转换等主要功能模块。以系统设计为基础,分别描述了系统客户端与服务器端的工作流程,说明了客户端核心模块Ajax引擎及服务器端GIS Web Services功能模块的实现,分析了GIS Web Services地图操作功能以及定位功能的实现过程。在浏览器端不需要安装任何插件的情况下,采用Ajax引擎异步调用GIS Web Services的方式实现了系统的功能。实验表明,在网络带宽不变的情况下,采用Ajax和GIS Web Services相结合模式的车辆监控系统,降低了浏览器与服务器之间的通讯量,提高了地图的加载速度,解决了在因特网上进行车辆监控时的车辆定位、动态跟踪、轨迹回放、最短路径等关键技术难题,具有一定的实用价值。更多还原

【Abstract】 Vehicle monitoring system is a part of intelligent transportation system. Its basic function is real-time vehicle positioning and condition monitoring of vehicles. It costs a lot to develop and deploy traditional vehicle monitoring systems based on C/S (Clint/Server) structure which has poor scalability. By them, users can not access to information quickly and conveniently too. Therefore, the vehicle monitoring system based on B/S (Browser/Server) structure has become the mainstream.With the research and analysis of WebGIS (Web Geographic Information System), Ajax (Asynchronous JavaScript and XML), GIS Web Services and other key technologies, a B/S mode vehicle monitoring system based on Ajax and GIS Web Services is designed to solve problems such as poor system security and complex Client deployment caused by plug-ins usually installed in the browser. The system’s principle, architecture and main functions are introduced. Database and main modules, such as real-time monitoring, track intervals, path planning, map matching and coordinate conversion, are designed in detail.According to the system’s architecture, the work flows of browser and server are introduced respectively. Ajax engine, the core component of browser, and the GIS Web Services in the server are realized. It has also been analyzed that how map operating and vehicle positioning functions can be realized. All in all, the system functions are implemented by the way that Ajax engine invokes GIS Web Services asynchronously.Experiments show that with unchanged network bandwidth, the vehicle monitoring system based on Ajax and GIS Web Services can reduce the communication between server and browser and can increase the speed of map loading. The technological difficulties of monitoring vehicle on Internet, such as real-time positioning, dynamic tracking, track intervals and shortest path, are solved. This system is valuable in practice.更多还原