【作者】 刘明辉；

【导师】 张凡；

【作者基本信息】 北京交通大学 ， 交通信息工程及控制， 2007， 硕士

【摘要】 随着经济的不断发展,城市交通拥堵的状况不断加剧,智能交通系统(ITS)作为一种解决交通拥堵问题的全新方法,在国内外迅速发展起来。车载监控系统是ITS的重要组成部分,它可以实时、准确的掌握车辆的运行状况、道路的拥挤状况,及时进行对车辆的调度,避免交通堵塞,确保车辆和道路处于健康的工作状态,对它的研究具有很大的经济效益和社会效益。本文首先分析了现有的车载监控系统的设计原则及工作原理。目前车载监控系统的无线传输部分大多采用GSM通信系统,通过GSM承载的数据通信业务,实际应用的传输时延不小于6秒,难以满足系统实时性较高的需求。继GSM后出现的GPRS通信技术采用了分组交换、最高传输速率达171.2Kbps、通信费用低,较GSM通信系统中的电路交换、传输速率慢、资源利用率低、通信费用高等缺点,GPRS通信技术优势明显。因此采用GPRS通信技术来替代GSM无线数据传输部分成为车载监控系统的发展方向。本文通过对GPS卫星定位理论、卫星数据的处理分析与研究,提出了基于指数平滑的处理方法和载波相位平滑处理方法,大大提高了信息的精度。本文以GPS卫星定位系统为基础,以ARM嵌入式系统作为硬件平台,以GPRS无线通信技术为依托,建立了一套公交信息系统。系统采用了Win Socket进行通信,解决GPRS通信网络和Internet网络融合与连接的问题,同时提出的子网分配方案解决了监控终端分布问题。更多还原

【Abstract】 With the development of economic,the condition of city traffic block becomes more and more aggravated, as a new method of resolving the traffic block called ITS,develops quickly in our country. The monitor system for car is the most important part of the ITS, for it can really master the condition of running car promptly and accurately the condition of the road block, and manage the running cars promptly to avoid the traffic block, and make the cars and roads in well working condition.so the research of ITS can make tremendous and benefic of society and economic.This paper analyses the designing and working principle of existing monitor system for car firstly. from these monitor system for car we can find that most the wireless transmission system of these monitor system for car use the GSM communication system,the business data communication rely on the GSM whose delay of transmission can be less than six seconds actually,so it can not satisfy the requirement of the system promptly. after the technical of GSM ,another new technical of GPRS appears, the GPRS was the technical of group exchange, the higher speed of transmission can be up to 171.2Kbps , with the lower expenditure.the GSM was the technical of circuit exchange , the shortage of GSM is that the transmission speed is lower, the utilization rate of resource is lower and the expenditure is higher , contrast to the shortage of GSM , the advantage of GPRS is obvious , so the usage the GPRS in the wireless transmission instead of GSM will be the development direction of monitor system for car. After the research of the theory of GPS satellite fixed position and the data of satellite, this paper puts forward of index smoothness and carrier wave smoothness, this method can raise processing precision higherly. on the basis of GPS fixed position system , ARM embedded system and the technical of GPRS wireless communication ,we can establish a new set of public traffic information system.this system was the winsocket technology to communicate, resolve the problem of communication net join , and use the subnet distribution to resolve the problem of distribution of monitor terminal.更多还原