Optimization Research Of Traveling Wave Method In Railway Cable Fault Detection

The railway signal cable is the information transmission channel between the train command system and the train operation.The detection of the signal cable is one of the guarantees for the safe operation of the train.The fault detection and fault location of railway signal cables are related to the safety of railway transportation.Based on the traveling wave method,this paper studies the fault detection model and detection method of railway signal cables.The application of Time Domain Reflectometry(TDR)and Spread Spectrum Time Domain Reflectance(SSTDR)in signal cable detection is studied emphatically.Firstly,this article combines the propagation characteristics of the cable to establish a fault detection model for the signal cable.According to traveling wave transmission and fault types,a time-domain reflection simulation model was established,and an algorithm for quickly distinguishing fault types was designed.Based on this,a prototype was made for verification.On-line detection methods: Sequence Time Domain Reflectometry(STDR)and Spread Spectrum Time Domain Reflectometry,the basic principles,fault location algorithms and the characteristics of test signals are studied.The transmission sequence of the test signal was optimized,and the optimal test signal sequence was determined.Secondly,to solve the problem that the accuracy of the SSTDR detection method decreases during long-distance cable detection,it is found that the test signal superimposed in the collected signal has a greater impact on the test result.A fault detection scheme for signal synchronization algorithm is designed,and an optimized algorithm for fault detection is given.Without increasing hardware cost and storage space,the test signal superimposed in the collected signal is filtered out,which improves the calculation result.The ability to identify cross-correlation peaks.Finally,build a physical verification module,use DDS direct frequency synthesis technology,and use FPGA to generate test signals.Different distances and different faults are tested,and the results show that the scheme designed in this paper can quickly realize fault location and fault identification.There are 53 pictures,4 tables,and 60 references.