车载终端是属于车辆监控系统的一部分，是智能交通系统（ITS）的重要环节。它将先进的全球卫星定位技术、数据库技术和现代通信技术与嵌入式计算机系统于一体，实现了车辆定位、导航和实时信息发布等功能，为用户提供便捷的服务，帮助用户能够准确、安全、快速地获得车辆信息，到达目的地。 本论文通过对车载终端系统的研究，根据其要求成本低、体积小、性能可靠等问题，提出了一种基于北斗和GPRS车载终端的设计方案。该方案中采用了嵌入式系统的设计思想，以ARM9处理器为硬件平台，扩展其他外设，完成了硬件电路的设计。软件方面采用嵌入式Linux操作系统，并在此基础上进行应用软件设计。该车载终端可以进行北斗数据的接收和记录，实现车载终端系统的定位，并结合GPRS无线传输技术及以太网信息传输技术实现数据传输，这种多信道通信方式，提高了数据传输的效率与安全，降低了数据传输的误码率。 本课题在硬件上设计了以三星公司S3C2440A处理器为核心的控制电路，包括存储器、内存及电源电路等，并实现了UM220北斗模块、WG-8010 GPRS模块和以太网模块与S3C2440A处理器的数据交换；软件上采用linux操作系统，完成了系统的裁剪、编译和移植。并在linux操作平台下使用QT软件设计用户界面程序，通过多线程编程的方法完成串口通讯的设计和北斗定位数据的提取及发送。 本车载终端具有多种通信方式，以GPRS、以太网通信主，北斗通信为辅，防止在特殊情况下通信中断的现象发生。信道选择采用灰色关联分析法，对其各个属性值进行处理，通过关联度确定最优信道的选择。 最后对此嵌入式车载终端系统进行了实验验证，实验证明linux系统与QT图形用户界面可移植到ARM处理器中，采集了车辆定位信息。为北斗和GPRS在车载终端中的应用打下了基础，对进一步研究提出了建议和展望。

The vehicle terminal is a part of the vehicle monitoring system. It is also an important part of intelligent transportation system (ITS). It is applied to the global satellite positioning technology, database technology and communication technology. They and embedded computer system are set in one body. It achieves the function such as vehicle positioning, navigation and real-time information. It provides users with convenient services, helping users to be able to accurate, safety, vehicle information quickly and then reaches the destination. This thesis mainly discusses the characteristics of the vehicle terminal system. According to the requirements of low cost, small volume, reliable performance, this dissertation put forward a design scheme based on beidou and GPRS car terminal.The program uses embedded system design ideas with ARM9 processor as the hardware platform, expansion of other peripherals to complete the design of the hardware circuit. Based on the embedded Linux operating system, this dissertation designs the application software. The data of Beidou can be received and recorded by the car terminal and then realize the positioning function of the vehicle terminal system. Combining with GPRS wireless transmission technology and Ethernet information transmission technology, the car termical system can realize data transmission. This multi-channel communication method can improve the efficiency and safety of the data transmission, reducing the error rate of data transmission. This topic on hardware design for samsung S3C2440A processor as the core of control circuit, including memory and power supply circuit and achieves the UM220 beidou module, GPRS module and Ethernet module WG - 8010 with the S3C2440A processor data exchange. As for software design, this dissertation uses linux operating system to achieve cutting, compiling and transplanting of it. It makes use of QT to design user interface program for Linux operating platform. Completing serial communication design and beidou positioning data extraction and send by using the method of multithreaded programming. This vehicle terminal has many kinds of communication mode, consisting of GPRS, Ethernet communication and Beidou communication is complementary to prevent the communication interrupt occur under special circumstances. Channel selection uses gray relational analysis to deal with the value of their individual properties, which can determine by the degree of association channel selection. Finally, this embedded vehicle terminal system validated by experiment. The experiment proves that the Linux system with the QT graphical user interface can be transplanted into the ARM processor .It successfully collects vehicle positioning information. Through this experiment of the analysis for the beidou and GPRS application in the vehicle terminal laid the foundation for the application, some suggestions and prospect for further researches can be put forward.