跨平台嵌入式地理信息系统关键技术研究

发布时间：2018-11-27 12:46

【摘要】：嵌入式GIS作为当今GIS领域研究的一个重要方向,具有广阔的应用前景。但由于受到嵌入式环境平台多样性和资源有限性的影响,大多数嵌入式GIS都是针对具体的嵌入式软硬件环境进行设计,功能相对简单,无法实现软件的跨平台应用。本文主要针对上述问题,着重研究嵌入式GIS跨平台的实现方法,并以此为基础,研究嵌入式GIS实现过程中的关键技术。主要研究内容如下:1.分析了嵌入式GIS的研究背景、相关理论与技术现状。阐明了嵌入式GIS的研究背景与意义,总结了嵌入式GIS特点、与桌面GIS的技术差异及其相关的实现技术与方法,详细分析了嵌入式GIS国内外研究现状和发展趋势,并指出了其中存在的主要问题。2.对嵌入式GIS跨平台的相关技术进行了深入研究,并在此基础上设计了跨平台嵌入式GIS的体系结构。该体系结构按照层次化结构进行设计,在底层硬件平台和操作系统之上增加了GIS应用中间件平台,使得GIS软件的开发不再依赖于具体的运行环境,具有跨平台的特性。在GIS应用中间件平台上设计了GIS功能组件层,提出将嵌入式GIS的各项功能封装设计为可重用的GIS功能组件,从而提高软件代码的复用性。3.设计了嵌入式GIS应用中间件—EGIS_MW平台。EGIS_MW平台的体系结构分为系统抽象层和GIS服务框架层。其中系统抽象层设计了操作系统适配器EGIS_OSAdapter类和图形绘制接口EGIS_OSDrawlnterface类,并将图形绘制功能封装于EGIS_OSAdapter类中,通过其对外提供GIS应用所需要的各种操作系统服务的统一接口。GIS服务框架层是以系统抽象层为基础,针对嵌入式系统的特点,设计了适合嵌入式GIS应用的GUI窗口系统、扩展图形接口、文件处理接口和定点计算接口。在GIS服务框架层中,GUI窗口系统采用面向对象方式进行设计,将窗口和常用的控件封装成类,通过观察者模式来管理消息传递;扩展图形接口主要是对系统抽象层中的点、线、面和文本的图形绘制接口进行扩展,设计了更为丰富的图形绘制接口;跨平台文件处理接口主要是利用EGIS_File类进行文件操作,在文件读取时自动将地理空间数据的字节序转换为本机字节序,实现跨平台的文件读取;定点计算接口主要是通过EGIS_FixedCalculate类将浮点运算转换为定点运算,从而大大提高了嵌入式GIS分析应用的实时性。4.研究了嵌入式GIS跨平台地图显示技术。对电子地图的特点和地图显示的平台相关性进行了分析研究,在此基础上,总结出在嵌入式环境下进行地图显示必须解决跨平台与高效显示两个方面问题;设计了基于EGIS_MW平台的地图显示引擎体系结构,并在此基础上实现了跨平台的地图显示符号库,从而使地图显示引擎具有完全的平台无关性;设计了适应于嵌入式环境多尺度表达的多源数据混合组织模型,并针对数据组织模型建立了地理空间数据的多级混合索引;设计了适应于嵌入式GIS地图显示的基于多缓存的并行调度显示算法,并通过实验验证了算法以及数据组织模型的高效性。5.研究了嵌入式GIS中的路径规划技术。分析了嵌入式GIS路径规划的特点,从而得到嵌入式环境下路径规划模块的设计原则;设计了满足嵌入式GIS路径规划跨平台应用的基于EGIS_MW平台的体系结构,在该体系结构中,主要是基于EGIS_MW平台提供的文件接口和定点计算接口进行路径规划模块的设计;研究并设计了路网数据的物理存储和内存组织结构,对于路网数据的物理存储采用适应于嵌入式环境多尺度表达的多源数据混合组织模型进行组织和存储,对于路径计算时内存中路网数据的组织按照前向关联边结构进行存储;提出了满足实时导航应用的基于转换路网的分层搜索A*算法,通过实验验证了算法能够识别并处理各种交通管制信息以及交叉口延误的影响,并且具有很高的运算效率,能够完全满足嵌入式GIS实时导航的应用需求。本文的研究成果已经在笔者开发的多个具有不同软硬件环境的嵌入式GIS中得到了应用,实际应用表明:基于本文的研究成果可以快速实现满足实用要求的跨平台嵌入式GIS应用软件,对于促进嵌入式GIS快速移植与扩展应用具有重要的理论意义和实用价值。
[Abstract]:The embedded GIS is an important direction in the field of GIS, and has a wide application prospect. However, due to the diversity of the embedded environment and the limitation of resources, most embedded GIS is designed for the specific embedded software and hardware environment, and the function is relatively simple, and the cross-platform application of the software cannot be realized. Based on the above-mentioned problems, this paper focuses on the implementation of the embedded GIS platform, and based on this, the key technology in the implementation of the embedded GIS is studied. The main content of the study is as follows: 1. The research background, relevant theory and technology status of the embedded GIS are analyzed. This paper expounds the research background and significance of the embedded GIS, summarizes the characteristics of the embedded GIS, the technical differences with the desktop GIS and the related implementation techniques and methods, and analyzes the present situation and the development trend of the embedded GIS at home and abroad, and points out the main problems. In this paper, the cross-platform technology of embedded GIS is deeply studied, and the architecture of cross-platform embedded GIS is designed. The architecture is designed according to the hierarchical structure, and the GIS application middleware platform is added on the bottom hardware platform and the operating system, so that the development of the GIS software is no longer dependent on the specific operating environment and has the characteristics of cross-platform. The GIS function component layer is designed on the GIS application middleware platform, and the function package of the embedded GIS is designed as a reusable GIS function component, so that the reusability of the software code is improved. The embedded GIS application middleware and EEGIS _ MW platform are designed. The architecture of the EGIS _ MW platform is divided into the system abstraction layer and the GIS service framework layer. The system abstraction layer is designed with the EDIS _ OSAdapter class and the drawing interface EGIS _ OSDrawlnterface class of the operating system adapter, and the graphics rendering function is encapsulated in the EGIS _ OSAdapter class, and the unified interface of the various operating system services required by the GIS application is provided through the system abstraction layer. The GIS service framework layer is based on the system abstraction layer, and designs the GUI window system, the extended graphic interface, the file processing interface and the fixed point calculation interface which are suitable for the embedded GIS application based on the characteristics of the embedded system. in the GIS service framework layer, the GUI window system is designed by adopting an object-oriented mode, the window and the common control are encapsulated into classes, and the message passing is managed through the observer mode; and the extended graphics interface is mainly a point and a line in the system abstraction layer, the cross-platform file processing interface is mainly used for file operation by using the EGIS _ File class, and the byte order of the geospatial data is automatically converted into the byte order of the machine when the file is read, and the fixed point calculation interface is mainly used for converting the floating point operation into a fixed point operation through the EGIS _ FixedCalculation class, so that the real-time property of the embedded GIS analysis application is greatly improved. The cross-platform map display technology of embedded GIS is studied. Based on the analysis of the characteristics of the electronic map and the platform dependence of the map display, the two aspects of cross-platform and high-efficiency display of the map display in the embedded environment are summarized, and the architecture of the map display engine based on the EGIS _ MW platform is designed. on the basis of which, a cross-platform map display symbol library is realized, so that the map display engine has full platform independence; and a multi-source data mixed organization model suitable for multi-scale expression of the embedded environment is designed, and a multi-level mixed index of the geospatial data is established for the data organization model, a parallel scheduling display algorithm based on the multi-cache is designed for displaying the embedded GIS map, and the high efficiency of the algorithm and the data organization model is verified through experiments. The path planning technology in embedded GIS is studied. The characteristics of the embedded GIS path planning are analyzed, the design principle of the path planning module under the embedded environment is obtained, the architecture of the EGIS _ MW platform based on the embedded GIS path planning and cross-platform application is designed, The design of the path planning module is mainly based on the file interface and the fixed-point calculation interface provided by the EGIS _ MW platform, and the physical storage and the memory organization structure of the road network data are researched and designed, the physical storage of the road network data is organized and stored by adopting a multi-source data mixed organization model which is suitable for multi-scale expression of the embedded environment, and the organization of the road network data in the memory is stored according to the front related edge structure for the path calculation; A hierarchical search A * algorithm for real-time navigation applications is presented, which can identify and process various traffic control information and the influence of intersection delay, and have a high operational efficiency. and the application requirement of the embedded GIS real-time navigation can be fully met. The research results of this paper have been applied in a number of embedded GIS with different hardware and software environments, and the practical application shows that the application software of the cross-platform embedded GIS which can meet the practical requirements can be quickly realized based on the research results of this paper. It is of great theoretical and practical value to promote the application of embedded GIS.
【学位授予单位】：解放军信息工程大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：P208

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