【作者】 王磊；

【导师】 刘文生；

【作者基本信息】 大连交通大学 ， 计算机应用， 2007， 硕士

【摘要】 随着嵌入式微机控制技术和现场总线技术的发展，现代列车的过程控制已从集中型的直接数字控制系统发展成为基于网络的分布式控制系统。IEC-61375—列车通讯网络(TCN)标准是IEC联合UIC经过十年的工作，提出的一个用于规范车载设备数据通讯标准，列车通讯网络分为用于连接各节可动态编组的车辆的列车级通讯网WTB和用于连接车辆内固定设备的车辆通讯网络MVB。基于分布式控制的MVB(多功能车辆总线)是IEC61375-1(1999)TCN的标准方案，与WTB(绞线式列车总线)构成的列车通讯总线具有实时性强、可靠性高的特点。作为MVB设备上唯一专用核心器件MVBC(多功能车辆总线控制器)，其生产技术为国外少数厂商所垄断，因此，国内对于MVB总线的研究和应用也受到国外技术封锁和价格等因素的限制。为了对MVB作广泛深入的研究和应用，自主开发MVBC是首要任务。正是基于这种原因，本文对TCN中的MVB技术进行了仔细的研究，分析比较了MVB同其他几种通用现场总线的异同。并在深入理解MVB的通信机制的基础上，按照多功能车辆总线的标准，设计了数字信号处理器(DSP)+可编程逻辑阵列(CPLD)的MVB控制系统。该设计的核心部分包含一个用于链路层和网络层的微控制器，一个用于执行物理层的编码／解码器(CPLD)和总线驱动器，以实现从节点通信。论文详细介绍了TCN的体系结构和MVB的基本原理，从理论上对其进行了分析，通过与IEEE802.3和以太网中广泛使用的载波监听多点接入(CSMA／CD)数据链路控制方式进行的对比分析，表明MVB传送过程数据时在吞吐率、时延等方面均具有优势。虽然在传送消息数据时，CSMA／CD优势较明显，但考虑到其MAC最短帧长的限制和阻塞信号造成的信道浪费，以及所选用的退避算法不能保证通信的可靠性和及时性，因此MVB更适合应用于实时性和安全性要求非常高的列车通信网控制系统。设计给出了系统总体和各功能模块框图以及详细的硬件原理图，用Verilog HDL程序实现了CPLD内部模块的功能，在MAXPLUSII集成软件开发环境下做了调试仿真，给出了仿真试验结果，并对试验结果做了详细的分析。更多还原

【Abstract】 With the development of the technology of embedded microcontrol and field bus, the process control of modern train has developed from concentrated direct digital control system to distributed control system which based on network.IEC-61375-Train Communication Network(TCN) Standard is IEC association with UIC adopted a standard for standardizing the communication of device data on train,TCN is divided into train level communication network—WTB which is used for connecting each dynamically organized vehicle and vehicle level communication network - MVB which is used for connecting fixed devices in vehicle. MVB which based on contributed control is part of IEC61375-1(1999)TCN, together with WTB has strong time-critical characteristic and high reliability.MVBC(Multifunction Vehicle Bus Controler) is the only core part in MVB devices. The technology of its production is monopolized by foreign manufacturers, therefore research and application of MVB is limited by much factor,such as technology blockage. For researching and applying MVB,developing MVBC is the first task by ourselves. Therefore ,the paper focus on the the technology of MVB of TCN , analyzes and compares the differences between MVB and other kind of field bus. A control system which based on "DSP+CPLD Architecture" is designed according to MVB standard. The main part of this scheme includes a microcontroller for the link and network layers, a CPLD for the implementation of Encoder/Decoder of the physical layer, to perform a slave node in a MVB communication.MVB is higher advantage and latency time of MVB is lower than those of CSMA/CD (Carrier Sense Multiple Acess) during transmitting process data. Although the performance of CSMA/CD is better during transmitting message data, with respect to the extra spend caused by the limitation of minimum data field size in MAC frame and the jam signal when collision, and the selected back-off algorithm which can not assure a high reliability and real time communication. MVB is a deterministic and robust field bus more suitable for safety-sensitive systems which can operate in harsh and disturbed environments, for example inside railway vehicles of the train communication network.The paper give the whole system fuction module diagram and ciucuit principle picture in detail,and the code of interior function module which based on Verilog HDL. The simulation result which uses MAXPLUSII is given and analysed.更多还原