城轨列车传感器网络数据传输实时性能研究

发布时间：2019-06-06 18:16

【摘要】：本文依托于城轨列车传感器网络接入节点、复合节点与测试评估平台项目(国家863计划),对城轨列车传感器网络平台的建设进行了设计研究。国内的城市轨道列车上采用的列车控制技术多从国外引进,缺少自己的知识产权。尤其是目前没有独立的、大容量的、成套的列车运行安全状态实时感知系统,为列车的安全、可靠、准时运行提供保证,因此针对我国城市轨道运行安全特性,建立一套标准化、系统化的城轨列车传感器网络意义重大。首先,对传感器网络功能结构、网络结构、传感器数据的传输进行分析,提出了传感器网络中存在的技术问题。还指出了影响网络通信实时性的主要因素,在建立城轨传感器网络应主要解决网络关键节点调度策略问题,以满足平台实时性的要求。其次,设计一个城轨列车传感器网络数据传输平台,此平台可仿真实际运行的网络和系统。在平台中引入工业以太网通信技术。从传感器网络的功能需求角度出发,设计网络中的功能节点；从网络可靠性角度出发设计网络功能节点的组网方式,建立一个由数据采集层、数据接入层、数据传输层以及数据处理层组成的四层网络结构；根据功能节点的功能定义选择设备,搭建物理平台；设计数据传输模拟系统,实现平台的数据传输功能。再次,分析在城轨列车传感器网络数据传输平台中,影响网络通信延迟的主要因素,得出排队延迟的影响最大。为了降低数据的排队延迟,在IEEE802.1P标准帧结构中引入截止期限字段,并在网络关键节点处设计了优先级队列下FCFS与EDF相结合的调度策略。利用opnet仿真技术验证改进调度策略的有效性。最后,对城轨列车传感器网络中的延迟模型做了改进,利用改进的延迟模型评价平台的传输实时性能。网络演算算法中的服务曲线根据联合调度策略的工作原理进行定义。计算城轨列车传感器网络数据传输平台端对端传输的网络时延,分析结果得出网络时延小于数据的发送周期。由此可见,数据传输平台实时性能可以得到保证。
[Abstract]:Based on the access node of urban rail train sensor network, composite node and test and evaluation platform project (National 863 Plan), the construction of urban rail train sensor network platform is designed and studied in this paper. Most of the train control technologies used in domestic urban rail trains are introduced from abroad and lack of their own intellectual property rights. Especially at present, there is no independent, large capacity, complete set of train operation safety real-time sensing system, which provides a guarantee for the safety, reliability and punctual operation of the train, so in view of the safety characteristics of urban rail operation in our country, It is of great significance to establish a set of standardized and systematic urban rail train sensor networks. Firstly, the function structure, network structure and sensor data transmission of sensor network are analyzed, and the technical problems existing in sensor network are put forward. The main factors affecting the real-time performance of network communication are also pointed out. In order to meet the real-time requirements of the platform, the key node scheduling strategy of the network should be solved in the establishment of urban rail sensor network. Secondly, a data transmission platform of urban rail train sensor network is designed, which can simulate the actual running network and system. Industrial Ethernet communication technology is introduced into the platform. From the point of view of the functional requirements of sensor networks, the functional nodes in the network are designed. From the point of view of network reliability, the networking mode of network function nodes is designed, and a four-layer network structure composed of data acquisition layer, data access layer, data transmission layer and data processing layer is established. According to the function definition of the function node, the equipment is selected, the physical platform is built, and the data transmission simulation system is designed to realize the data transmission function of the platform. Thirdly, the main factors that affect the network communication delay in the data transmission platform of urban rail train sensor network are analyzed, and it is concluded that the queuing delay has the greatest influence. In order to reduce the queuing delay of data, the deadline field is introduced into the IEEE802.1P standard frame structure, and the scheduling strategy of combining FCFS and EDF under priority queue is designed at the key nodes of the network. Opnet simulation technology is used to verify the effectiveness of the improved scheduling strategy. Finally, the delay model in urban rail train sensor network is improved, and the improved delay model is used to evaluate the transmission real-time performance of the platform. The service curve in the network calculus algorithm is defined according to the working principle of the joint scheduling strategy. The network delay of end-to-end transmission of urban rail train sensor network data transmission platform is calculated, and the analysis results show that the network delay is less than the transmission period of the data. Thus it can be seen that the real-time performance of the data transmission platform can be guaranteed.
【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】：U270.38

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