Development Of Electromagnetic Environment Monitoring System For Urban Railway Station Equipment Room

With the rapid development of urbanization in China,the construction of urban rail transport is also developing rapidly.The urban rail transport which can transport passengers quickly,safely and comfortably is able to relieve the traffic tension in cities effectively.Communication and signal system plays a key role in the security operation of urban rail transport.Electromagnetic disturbance in space can affect the stability of communication system,so that it is very important to ensure that the electromagnetic environment of the communication equipment room can meet the requirements.This thesis analyzes the demand of the electromagnetic environment monitoring system used in the equipment room for communication system of urban rail transport station,and introduces the functional design of electromagnetic environment monitoring system in order to make sure the development direction of the system as well as the realized function.This thesis designs the architecture of system hardware which is combined with the results of field investigation that acquire from 11 communication equipment rooms of subway station in a city,and investigates key indicators and performance of instruments from different companies in the market.The instruments and equipments which selected can meet the actual needs after analysis.This thesis takes LabVIEW programming software as the development platform to design the architecture of system software,and introduces the designed idea as well as realized method of four core modules,including instrument and equipment control module,data processing module,data statistics module as well as data access & Web publishing module.The instrument and equipment control module mainly realizes the function of real-time communication with host-computer and automatic collection of monitoring data.Data processing module mainly realizes the function of raw data processing and curve drawing.Data statistics module mainly realizes the function of mathematical statistics,curve statistics and early warning information statistics.Data access & Web publishing module mainly realizes the function of storage and traceback of monitoring data as well as Web publishing of host-computer interface.This thesis designs and optimizes the host-computer operation interface of the system.Interface is divided into real-time monitoring interface and historical data traceback interface.The designed interface has good operability,friendliness and readability.This thesis introduces the verification test of the developed system.The verification test site is a semi-anechoic chamber of the Institute of Electromagnetic Compatibility,Beijing Jiaotong University.This test judges the effectiveness and reliability of the developed system by comparing the reference value measured by the field strength probe with the results obtained by the system monitoring whether they can meet a reasonable error range.The arrangement points of field strength monitoring probe and measuring antenna refer sampling points of field uniformity calibration test.Test site and instruments refer radiation immunity test.But the content of this verification test is different from the above two tests.After verification,the monitoring results of the developed system can meet the validity and reliability.The developed system can monitor the electromagnetic environment sensitive area of the equipment room for communication system in real time for a long time.The system can mark and record the frequency points that exceed safety limits and their corresponding amplitudes as well as current time,so that users can find abnormal electromagnetic environment data information in time,and ensure that the space electromagnetic environment of the equipment room for communication system can meet the requirements.