TCN数据传输实时性与可靠性的研究与实现

【作者】 陈楚；

【导师】 彭军；

【作者基本信息】 中南大学 ， 通信与信息系统， 2005， 硕士

【摘要】 列车通信网(TCN,Train Communication Network)是将列车上各智能部件连在一起的网络,它由多功能车辆总线和绞线式列车总线组成。为了列车的安全行使,列车通信网中的数据传输必须迅速和可靠。现有的局域网技术无法保证数据传输的实时性和可靠性。列车通信网是采用实时性协议的主从式网络,它针对数据的重要程度有两种不同的数据传输方式:周期性数据传输和非周期性数据传输。它在保证数据传输实时性的同时还能对数据差错进行严格的控制,因此很好的满足了现代列车对控制和信息传输的高性能要求。 本文首先研究了列车通信网的体系结构和网络中的两种数据的传输技术,对列车通信网上报文定时进行了详细分析,采用基于特征周期的变量轮询法来实现列车通信网中变量数据传输的实时性。针对列车通信网中的特殊帧格式和信号表示方式,提出在列车通信网中使用帧头、长度、编码规则和校验码来共同检测数据帧的正确性。并根据列车通信网的特点采用“半比特检错法”,使车辆总线数据帧能够在使用8比特作为校验和的情况下,仍能保持很高的检错率。最后,在成功搭建一个小型列车通信网的基础上,实现了网络中变量数据的实时通信,并采用基于曼彻斯特码元扩充和一种改进的校验和算法,编程实现了列车通信网中的数据差错控制。为实现列车通信网正常运行和列车安全行驶打下了坚实的基础。更多还原

【Abstract】 Train Communication Network (TCN) is a network that connects various intelligent parts in train. It covers multifunction vehicle bus and wire train bus. Rapidity and reliability are needed in data communication of TCN for security of train. Existing local network technology can’t ensure the real-time and reliability of data communication, TCN is a master-slave network which adopts real-time protocol, it has two different data communication modes according to the important degree of data, which are periodic data communication and non-periodic data communication. Data error can be strictly controlled when the real time of data communication, so the high-powered requirement of control and information communication of modern train can be satisfied well.The architecture and communication technology of two types of data of TCN are studied firstly, the method of data polling based on individual period is adopted to achieve the real time of process data on TCN by analyzing the message time of train bus detailedly. The method of using frame head checking, length checking, coding rule checking and check code checking to examine the correctness of data frame in TCN aiming at the special format of frame and the expression mode of signal is proposed. "Semi-bit error detection method" according to the characteristic of TCN is used to make train data frame maintain very high error detection rate using 8 bit as check sum. At last, the real time communication of network data and data error control based on extending Manchester code and an improved CRC algorithm in TCN are implemented based on constructing a small TCN successfully. Firm basis is made for normal running of TCN and safety of the train.更多还原