高速铁路车地无线数据传输高可靠性和高实时性的研究与实现

发布时间：2018-10-25 19:37

【摘要】：随着我国经济建设的快速发展,我国的铁路建设也有了日新月异的发展,但是在我国铁路网络中占重要地位的高速铁路信息化还存在着各种技术难题。高速铁路信息化对于高速列车的运维有重要的意义,通过基于无线公网的运维数据通信,使得地面监控系统对列车的实时状况及时了解,可以方便做出列车的每日例行入库检查、检修的安排,提高了高速列车的运维效率。因此高速列车上基于无线公网的数据传输是高速铁路信息化管理的一个关键技术,然而由于在高速列车上的无线通信环境较为恶劣,导致无线数据传输的可靠性和实时性很难有较高的保障,这成为高速铁路信息化又一个瓶颈。基于无线公网的无线数据传输,面对我国现有的公共网络提供商的通信环境,很难通过网络本身对高速列车的无线数据通信在短期内有较大的改观。因此,本文提出在应用层优化数据传输的策略,对数据的发送和接收做出相应的控制,提高数据通信的可靠性和实时性。本文主要工作如下： 1.在可靠性方面,本文通过采用诸多保护措施来保障数据传输的可靠性,同时保障列车运行时车载无线通信设备无人值守运行环境的可靠性。采用有限状态机的方式提高软件设计的可靠性,便于网络状态控制；通过使用守护进程对无线通信软件进行无人值守的软保护,当通信软件由于不可预估的故障发生时,会造成软件工作异常,这时守护进程可以对软件进行自恢复；当守护进程无法对软件进行自恢复时,本文通过硬件看门狗对其进行重新上电自恢复；本文在应用层采用有应答的和分包发送的策略以提高数据的传输成功率。 2.对于实时性方面,本文采用基于无线信号强度预测的发送策略,降低数据发送失败的概率；通过数据分类传输,将数据可以按类存储,减少公有信息的重复发送；通过数据压缩的方法,减少数据发送的数据量,发送数据量的减少也就提高了数据通信的实时性。最后通过在运行的高速列车上进行实际测试以及一些仿真实验的验证,结果表明,本文提出的保障车地数据通信的可靠性和实时性的诸多方法确实有很好的效果,完全可以满足高速列车运维的实际需要,同时一部分优化方法已经在本实验室开发的无线数据传输装置(WTD)应用,并且在高速列车上运行,效果良好。
[Abstract]:With the rapid development of our country's economic construction, the railway construction of our country has also been developing with each passing day, but there are still various technical problems in the informationization of high-speed railway, which occupies an important position in the railway network of our country. High-speed railway informatization is of great significance to the operation and maintenance of high-speed trains. Through the operation and maintenance data communication based on wireless public network, the ground monitoring system can understand the real-time status of trains in a timely manner. The operation and maintenance efficiency of high-speed trains can be improved by making daily routine storage inspection and maintenance arrangement. Therefore, data transmission based on wireless public network on high-speed train is a key technology of high-speed railway information management. However, the wireless communication environment on high-speed train is relatively bad. It is difficult to guarantee the reliability and real-time of wireless data transmission, which becomes another bottleneck of high-speed railway informatization. The wireless data transmission based on the wireless public network, facing the communication environment of the public network provider in our country, it is very difficult to improve the wireless data communication of the high-speed train through the network itself in the short term. Therefore, this paper proposes a strategy to optimize data transmission in the application layer, to control the transmission and reception of data, and to improve the reliability and real-time performance of data communication. The main work of this paper is as follows: 1. In terms of reliability, this paper adopts many protection measures to ensure the reliability of data transmission and the reliability of the unattended environment of the on-board wireless communication equipment while the train is running. The finite state machine is used to improve the reliability of the software design and facilitate the network state control. By using daemons to protect the wireless communication software unattended, when the communication software occurs due to unpredictable failures, the software work will be abnormal, and the daemon can self-recover the software. When the daemons can not recover the software, the hardware watchdog is used to reboot the daemons. In order to improve the success rate of data transmission, this paper adopts responsive and sub-sent strategies in the application layer. 2. In the aspect of real-time, this paper adopts a transmission strategy based on the prediction of wireless signal strength to reduce the probability of data transmission failure, through data classification transmission, the data can be stored by class, and the repeated transmission of public information can be reduced. Through the method of data compression, the amount of data sent is reduced, and the reduction of the amount of data sent improves the real-time performance of data communication. Finally, through the actual test on the running high-speed train and the verification of some simulation experiments, the results show that the methods proposed in this paper to ensure the reliability and real-time performance of the vehicle-ground data communication are indeed very effective. It can fully meet the practical needs of high-speed train operation and maintenance. At the same time, some of the optimization methods have been applied in (WTD), a wireless data transmission device developed in our laboratory, and run on the high-speed train with good results.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U29-39;TN92

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