使用开源平台和HTML5 Canvas构建福州市区实时路况WebGIS系统

发布时间：2018-09-18 15:56

【摘要】：面对福州市道路交通日益增大的压力,改善城市道路交通拥堵、提高居民出行效率不仅需要加强城市道路基础设施建设,构建实时路况系统合理引导居民出行也具有重要意义。本文构建的福州市实时路况WebGIS系统能够将实时交通路况信息以可视化的形式展现,能够实现普通用户使用PC端和移动终端设备对路况信息以路况地图的方式进行浏览。另外,系统提供的基于实时路况的最优路径分析功能,让用户能够随时、随地对当前交通状况进行分析,并且提供依据当前路况的最优路径选择方案,辅助用户进行提前绕行决策,最终达到合理引导居民出行,提高居民出行效率的目的。在分析总结当前以C/S、B/S及RIA方式构建的各主流实时路况WebGIS系统实现方式利弊的基础上,针对传统WebGIS矢量数据在浏览器中缺乏可视化统一标准以及采用地图切片方式响应速度慢的现状,本文提出采用HTML5Canvas技术作为PC端和移动终端实时路况的表现方式,并且创建了能够加载单个矢量图层的客户端API——MapCanvas1.0。为解决MapCanvas1.0在加载单个矢量文件时存在响应速度慢、耗费流量的弊端。本研究中引入“矢量瓦片”概念,提出矢量瓦片生成和存储的操作规范,在原有MapCanvas1.0的基础上构建了能够加载矢量瓦片的客户端API——MapCanvas2.0,并且基于MapCanvas2.0实现了福州市实时路况在浏览器端的展现。经过试验证明,采用MapCanvas2.0加载矢量瓦片的方式对地图进行渲染能够有效避免查询路况时造成的流量损耗、提高响应速度、增强用户体验。本文系统服务器端采用开源平台构建,设计并研发了实时路况的路况信息采集模块和最优路径查询模块。在实时采集路况信息以辅助客户端显示的同时,系统提供基于当前路况通过输入起点、终点位置进行最优路径查询的功能。此外,服务器端具有良好的跨平台和可移植性特点,可大大减少系统开发、维护的成本。福州市实时路况系统的结构合理性,体现了软件设计中以数据为核心、可扩展性、开放性、安全性的特点。客户端采用以HTML5Canvas作为客户端绘制路况的方式不仅解决了采用瓦片方式加载速度慢、耗费流量的问题,也使得WebGIS在客户端矢量数据表现方式上具备统一标准,增强了跨平台性,并且“矢量瓦片”技术的提出和应用促使系统客户端渲染速度得到明显提高。系统采用开源平台构建节约开发成本的同时,增强了系统的跨平台特性。实验证明,系统能够满足用户使用PC端或移动终端对实时路况的查询、分析等需求,凭借其渲染速度快、节省流量的优点增强了用户体验,从而达到了缓解城市道路交通压力的目的。
[Abstract]:Facing the increasing pressure of road traffic in Fuzhou, it is of great significance to improve urban road traffic congestion and improve residents' travel efficiency not only by strengthening the construction of urban road infrastructure, but also by constructing real-time road condition system to guide residents to travel reasonably. The real time traffic condition WebGIS system in this paper can display the real-time traffic information in a visual form, and can realize that ordinary users can use PC terminal and mobile terminal equipment to browse the road condition information in the way of road condition map. In addition, the system provides an optimal path analysis function based on real-time road conditions, which enables users to analyze the current traffic conditions at any time and anywhere, and provides an optimal path selection scheme based on the current road conditions. In order to guide the residents to travel reasonably and improve the travel efficiency, the auxiliary users make advance detour decision. On the basis of analyzing and summing up the advantages and disadvantages of the realization of the mainstream real-time WebGIS system based on C / S / S and RIA, In view of the lack of unified visual standard for traditional WebGIS vector data in the browser and the slow response speed of map slicing, this paper proposes to use HTML5Canvas technology as the representation of real time traffic conditions of PC terminal and mobile terminal. And create a client API--MapCanvas1.0. that can load a single vector layer In order to solve the problem that the response speed is slow and the flow is consumed when MapCanvas1.0 loads a single vector file. In this study, the concept of "vector tile" is introduced, and the operation specification for the generation and storage of vector tile is proposed. Based on the original MapCanvas1.0, the client API--MapCanvas2.0, which can load the vector tile is constructed, and the real-time traffic condition of Fuzhou is displayed on the browser side based on MapCanvas2.0. It is proved by experiments that rendering the map by MapCanvas2.0 loading vector tile can effectively avoid the flow loss caused by querying the road condition, improve the response speed and enhance the user experience. The system server is constructed with open source platform, and the real-time traffic information collection module and the optimal path query module are designed and developed. While collecting the road condition information in real time to assist the client to display, the system provides the function of the optimal path query based on the current road condition through the input starting point and the end point. In addition, the server has good cross-platform and portability, which can greatly reduce the cost of system development and maintenance. The structure rationality of the real time road condition system in Fuzhou reflects the characteristics of data as the core, expansibility, openness and security in the software design. Using HTML5Canvas as the client to draw the road condition not only solves the problem that the loading speed is slow and consumes the flow by using the tile method, but also makes the WebGIS have a unified standard in the representation of vector data on the client side, and enhances the cross-platform property. And the development and application of vector tile technology can improve the rendering speed of the system client. The system uses open-source platform to construct and saves development cost, and enhances the cross-platform characteristic of the system at the same time. Experimental results show that the system can meet the needs of users using PC terminal or mobile terminal to query and analyze the real-time traffic conditions. With the advantages of fast rendering speed and saving traffic, the system enhances the user experience. In order to alleviate the pressure of urban road traffic.
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：U495;P208

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