The Research And Implementation Of The Distributed Railway Signal Microcomputer Monitoring System

The railway signal equipment is important rail infrastructure. Signal equipment malfunctions or runs out of the normal status, which may cause trains delay or even cause safety accidents. It is necessary to do a systematic monitoring and maintenance of all kinds of signal equipment. Modern railway signal microcomputer monitoring system, which uses advanced science technology and management technology, monitors the signal devices in many aspects, and provides a scientific basis for electrical department to grasp the current state of equipment and accident analysis, and can make the execution of warning and alarming on the malfunctions.In the existing Microcomputer Monitoring System, the state of signal devices is collected by the isolated sampling units in the machine room, and is connected to the various types of acquisition machines by laying a certain amount of sampling lines. Then the collected state data is converted and handled by the acquisition machines, and is gathered to the station computer. Deploying and maintaining the sampling lines needs lots of work and high requirement, and the situation of the mixed lines may occur. Besides, some state acquisition tasks of Microcomputer Monitoring System need to be carried out in the field of outdoor signal equipment. The status information of the outdoor signal equipment is processed by the devices in the machine room through the long distance communication cables. Though the data transfer is efficient and the reliability is high through the cables, the cable is deployed and maintained difficultly in some circumstances, and even worse,the destruction of some cable may cause accidents. According to the characteristics and needs of railway signal equipment, this article presents a kind of distributed monitoring system, based on the wireless sensor network.In the paper, the wireless smart sensor units, which replace the sampling lines, acquisition machines indoor and the long distance cables outdoor, are placed near by monitoring points in monitoring indoor or near by the signal equipment outdoor. The state data of monitoring object is collected and processed by the wireless smart sensor units, and is transmitted to the station computer. The new generation of wireless sensor network technology is a combination of wireless communication technology, intelligent sensor technology, microprocessor technology, distributed information processing technology and so on. It not only can collect the data about the monitoring objects and area, but also can organize the hoc networks, according to the different monitoring requirements. Therefore, variety of data will be collected and transited effectively. The wireless sensor network is a new direction technology for monitoring signal equipment. The wireless sensor network adopted in design can expand the monitoring scope, and can solve some difficulty, which the existing computer monitoring system is not easy to monitor in some special cases.This paper elaborates the development process, hierarchical structure and related function of the railway signal microcomputer monitoring system in detail, and summarizes the wireless sensor network technology, related communication protocol and ZigBee wireless communication technology. Based on analyzing the monitoring function requirements, it designs a distributed monitoring system based on ZigBee network. According to the different monitoring objects and monitoring range, the system is divided into outdoor monitoring system and indoor monitoring system. According to the two systems, two kinds of corresponding wireless communication network structure are designed. In addition, the hardware design of the communication module and the function module, with the software analysis and design of the mesh and star wireless communication structure, acquisition module are the key points of this paper. Finally, this paper briefly analyzed the influence factors on the system of network performance, and put forward some related method to increase the monitoring distance and reduce the node power consumption.