High-speed rail track health online monitoring method based on phi-OTDR

Abstract

The invention discloses a phi-OTDR-based high-speed rail track health online monitoring method, which uses existing communication optical fibers laid along a railway for sensing to capture vibration information of the railway after a train passes by. The method comprises the following steps: organizing data into a waterfall plot with gray scale representing intensity according to a time axis, performing wavelet decomposition filtering, extracting a track generated by train running by adopting an edge extraction algorithm based on dynamic programming, and dividing two regions before and after the track; making time-frequency analysis on the track area and the areas before and after the track, extracting a wheeltrack vibration characteristic frequency spectrum and a steel rail resonance characteristic frequency spectrum, and obtaining a wheeltrack vibration characteristic frequency and a steel rail resonance characteristic frequency through a characteristic frequency spectrum extractionalgorithm; continuously repeating the monitoring process to obtain the change of the steel rail vibration characteristics along with time, and establishing a corresponding database; comparing the newly acquired data with the data in the database and updating the database to realize real-time health monitoring of the train and the steel rail.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to an online monitoring method for high-speed rail track health based on φ-OTDR. Background technique [0002] The safety of high-speed rail operation has always been a major issue related to economic development and personal safety. In order to ensure the safety and smoothness of high-speed rail transportation and improve operational efficiency, it is necessary to monitor the health status of high-speed rail tracks in real time. However, the electrical sensing elements currently used have poor moisture-proof and anti-electromagnetic interference capabilities, and are unstable under harsh monitoring conditions. When used in complex monitoring environments for a long time, faults such as zero point drift are prone to occur, which greatly On the other hand, the transmission distance of electrical signals in the channel is very short, it is difficult to form a large-scal...

AI Technical Summary

Problems solved by technology

However, the optical fiber is often prevented from being in the cable groove with a certain distance from the rail, and does not directly contact the rail and roadbed, and keeps a certain distance from the rail. The efficiency of vibration coupling to the optical fiber is low, which leads to more stringent requirements for sensitivity.

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