Railway Vibration Signal's Detection And Research Based On ?-OTDR

In recent years,the rapid development of high-speed railway in our country has put forward higher requirements for railway operation safety detection and monitoring technology.At present,the railway safety monitoring technology has many disadvantages,such as high complexity,high maintenance cost,poor ability to resist electromagnetic interference and so on.Phase-Sensitive Optical Time-Domain Reflectometer(?-OTDR)distributed optical fiber sensing system is a kind of distributed sensing system based on optical fiber sensing and transmission.The?-OTDR system has many advantages,such as simple system,low maintenance cost,strong ability to resist electromagnetic interference and can achieve a wide range of distributed detection.This paper introduces the basic principle of ?-OTDR technology and railway safety monitoring technology research status,the main content of the research is the innovation of using ?-OTDR technology applied to the railway operation safety testing and monitoring,collecting and processing the rail vibration signal in real time,informed the train driving trajectory and foreign invasion track information.This paper mainly completed the following aspects of research work:1.The first chapter introduces the background and significance of the research.This paper mainly introduces the research and application status of railway operation safety field,including train track detection and foreign body intrusion track detection.2.The second chapter introduce the basic principle of ?-OTDR and its application.In the third chapter,we applies the ?-OTDR technology into the field of railway transportation,introduces the experimental environment,and uses the?-OTDR technology to realize the real-time and continuous acquisition of the vibration signal.3.This paper designs a method based on the ?-OTDR technology of train track detection to realize the real-time detection of the train track.The method uses the?-OTDR technology to collect the real-time track vibration signa and wavelet denoising,calculate the different time signal,the threshold processing and low-pass filtering,and the extraction of signal amplitude of feature,judging the feature of amplitude to determine the effective signal train,analysis of the effective signal by train for different time travel,to obtain the position of the train,the train speed and driving direction.4.This paper designs a method based on the ?-OTDR technology to detect the railway foreign body intrusion.This method is used to simulate some abnormal events artificially such as the invasion of railway tracks and landslides,and the continuous acquisition of railway vibration signals by using the ?-OTDR technology.Wavelet denoising,short-time Fourier transform and autoregressive model spectrum estimation processing to extract the frequency characteristics of the signal,through the analysis of the frequency characteristics of the signal,to determine whether the monitoring sections of track arbitrary position have any incidents,according to the position's around position to distinguish the normal train travel from the foreign invasion.