【作者】 张俊平；

【导师】 诸昌钤；

【作者基本信息】 西南交通大学 ， 交通信息工程及控制， 2002， 硕士

【摘要】 列车通信网络(TCN)是铁路列车车辆之间和车辆内部可编程设备互联传送控制、检测与诊断信息的数据通信网络。国际电工委员会(IEC)为此制定了IEC61375-1 TCN标准。然而在国内有关TCN技术除少量引进外，尚未形成具有自主知识产权的列车网络产品。有关支持IEC 61375-1标准的产品有限，而且价格昂贵。鉴于上述情况，本文对TCN技术进行深入研究以掌握其核心技术。 TCN的西大特点是：(1)为了保证数据传送时间的确定性，IEC 61375-1标准在链路层采用轮询机制；(2)由于列车编组经常变化，导致列车总线网络设备地址变化，为此IEC 61375-1设计了列车初运行过程，以实现列车组成变化后车辆地址的自动分配。 本文主要内容分为两部分：1．绞线式列车总线(WTB)初运行模拟系统。该系统在实验室局域网(100M总线型结构)环境下基于Windows98和C++Builder 5．0平台利用Windows Socket编程技术开发完成，着重实现初运行过程中车辆节点的命名。程序运行结果表明系统可以模拟IEC 61375-1中初运行的功能。2．在归一化条件下对MVB轮询访问方式与CSMA／CD介质访问方式的分析比较。由于IEC 61375-1规定的数据通信速率为1Mbps，而一般以太网速率很高，为便于比较，进行归一化处理，都归算到1Mbps。对MVB和CSMA／CD在同等条件下所能达到的吞吐率、时延等指标分析计算，并由Matlab绘出曲线图。分析结果表明MVB在吞吐率、时延等方面均具有优势。然而考虑到两方面的因素：(1)Ethernet采用的IEEE802．3标准指定的MAC帧最短数据域长是368位，不够时应装入填充比特，造成不必要的开销，而IEC 61375-1规定的最短过程数据仅为16位，最长不过256位；(2)由于归一化速率为1Mbps，而实际的Ethernet传输速率远远高于1Mbps。因此用CSMA／CD实现MVB轮询的功能还是可行的。更多还原

【Abstract】 Train Communication Network (TC.N) is a data communi cat ion network in which all control, detection and diagnosis information are carried for interconnecting programmable equipments between and within rail vehicles. The International Electrotechnical Commission (TEC) has constituted a TON standard ?DEC 61375-1. However, no train network products with independent knowledge property have been developed but few technologies relevant to TON been introduced in our country. On the other hand, products supporting IEC 61375-1 are limited with high price. Deep research on TCN technology is made in this paper considering above cases.Two notable characteristics of TCN are as follows: (1) Polling MAC strategy is adopted in link layer by IEC 61375-1 to ensure the certainty of data transmission time; (2) Train inauguration procedure is devised to realize the automatic allocation of rail vehicle address in the network.The paper consists of two nain parts: 1. A sinulating system ofWire Twisted Bus (WTB) inauguration. The system was completed usingWindows Socket programming technology based on Windows98 andC++Builder 5.0 station under the environment of our laboratory LAN(100M bus topology). The naming of vehicle nodes during inaugurationis emphasized. It is also indicated that the system may simulatefunctions prescribed in IEC 61375-1 by running the program. 2. Theanalysis and comparison between Multifunction Vehicle Bus (MVB)polling MAC mode and CSMA/CD MAC mode under normalizing condition.Normalization processing was made for contrast in that data rateregulated in IEC 61375-1 is 1 Mbps, while the data rate of generalEthernet is very high. Thus the normalizing rate is 1 Mbps. Theperformances such as throughput and time delay, etc. with respect toMVB and CSMA/CD under the same condition were analyzed. Moreover thecurves according to computing results were plotted by Matlab. Analysisresults show that MVB predominates at aspects of throughput and delay. Two pieces of reason which cause this result are: (1) IEEE 802. 3 standard adopted in Ethernet designates 368 bits minimum data field size in MAC fraae, filling bits will be loaded if data length is shorter than 368 bits, which causes extra spending. On the contrary, the naxiauB process data length in IEC 61375-1 is only 256 bits. (2) Actual Ethernet rate may be lOMbps, lOOMbps, lOOOMbps, which is far higher than 1VL Consequently it is likely that CSMA/CD fulfill functions of MVB polling strategy.更多还原