【作者】 刘庆敏；

【导师】 田岚；

【作者基本信息】 山东大学 ， 信号与信息处理， 2009， 硕士

【摘要】 嵌入式系统是当前最为热门的研究领域之一,也是“后PC时代”最有发展前景的方向之一。目前,它已经被广泛地应用于信息家电、手持通信设备、仪器仪表、汽车、航空航天、工业控制以及数据采集等应用领域,为人们的工作和生活带來了极大的便利。其中,GPRS DTU是嵌入式系统在工业控制和数据采集领域的重要应用,它可以实现将串口数据通过GPRS网络进行数据传输,提供了无线备份链路,增强了数据传输的可靠性。伴随着对智能化的需求日益增长,提出了智能化GPRS DTU的概念。除了原有的基本功能,还需要增加智能化功能模块,比如支持自动心跳、保持永久在线,支持远程登录,远程Web管理,远程自动更新等。这样就极大地节省了后期维护费用,降低了成本。因此,对智能化GPRS DTU的研究具有广泛的意义和良好的商业前景。本文主要是设计并实现智能化GPRS DTU的应用平台,对关键技术进行了深入研究。首先从理论的层次介绍了嵌入式系统的基本概念和设计流程,在理论研究和项目实践的基础上,总结了抓住本质、分层整合、协同分工、情景分析等学习方法;介绍GPRS DTU硬件平台的组成,以ATMEL公司的AT91RM9200为核心控制单元,以Telit的GM862作为GPRS功能模块,以实现工业级指标要求;总结出Linux下ELF文件转换为binary文件的方法,然后重点解决了U-boot应用于AT91RM9200重映射机制的修正,设计出面向智能化GPRS DTU的嵌入式混合文件系统(Cramfs+JFFS2+Initramfs),针对该文件系统对Linux-2.6.20进行了移植和裁剪;最后以串口/Ethemet数据网关的设计来说明应用开发的基本模型。本系统研发的关键技术均已获得相应的成果,对智能化GPRS DTU的发展给予了有力的技术支持。更多还原

【Abstract】 Nowadays, embedded systems are one of the most popular research fields and will be the most promising direction of the Post-PC Era. It’s widely used in Information Appliances (IA), hand-held communications equipment, instrumentation, automotive, aerospace, industrial control, data acquisition and so on. It has brought great convenience for people to work and live.GPRS DTU is an important application of embedded systems in the fields of industrial control and data acquisition. Its function is to transmiss serial data through GPRS network and to provide a wireless back up link. Therefore it improves the reliability of data transmission. With the growing demand for intelligence, the concept of intelligent GPRS DTU is put forward. In addition to the original basic functions, more intelligent modules need to be provided, such as maintaining a permanent on-line by automatic heartbeat, remote access, web remote management, automatic updates and so on. It could save the cost of maintenance and is more cost-effective and therefore the research on intelligent GPRS DTU has broad sense and good business prospects.This paper is aimed to design and implement GPRS DTU intelligent application platform and to deeply analyze the key technology on intelligent functions. First of all, the basic concept and design process of embedded systems are introduced based on the theoretical level, and some methods are summed up, such as seizing the essence, hierarchical integration, coordination division, scene analysis and so on; second, introduce GPRS DTU hardware platform, which adopts ATMEL’s AT91RM9200 as core control unit and Telit’s GM862 as GPRS module in order to achieve industrial-level requirement; third, sum up the method to convert Linux ELF format file to a binary file, and then focus on correcting U-boot’s unreasonable application on AT91RM9200’s remap mechanism and realizing the independence of U-boot’s boot mode; fourth, an embedded hybrid filesystem (Cramfs+JFFS2+Initramfs) for intelligent GPRS DTU design scheme is proposed, which is a key module of intelligent GPRS DTU. Meanwhile, port and customize Linux-2.6.20 kernel based on the needs of EFS and applications; finally, illustrate the basic theorial model of application development using design scheme of serial/Ethernet data gateway.The key technology on research and development of the GPRS DTU intelligent platform has got good results and gives a strong technical support for intelligent GPRS DTU.更多还原