A Method to Monitor Railway Tracks' Foreign Body Invasion Based on Phase Sensitive Optical Fiber Sensing Technology

A new method based on phase-sensitive optical fiber sensing technology (Φ-OTDR) is presented in this paper. The method first uses Φ-OTDR to acquire the original signal of railway tracks vibration for a while, then conducts filtering, short-time Fourier transform and auto-regressive model spectrum estimation of the original signal, After analyzing the frequency signal feature, we can determine whether any events have happened on the track, Finally, invasion events can be distinguished by comparing the signals between the position and the adjacent ones. This method only uses the existing rail cable, without additional workload of construction, and can achieve a wide range of distributed detection, which has important potential application value for railway operation safety and disaster prevention.