Real-Time Position and Speed Monitoring of Trains Using Phase-Sensitive OTDR

• Published in: IEEE photonics technology letters Vol. 26; no. 20; pp. 2055 - 2057
• Main Authors: Peng, Fei, Duan, Ning, Rao, Yun-Jiang, Li, Jin
• Format: Journal Article
• Language: English
• Published: New York IEEE 15-10-2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Monitoring; Optical fiber cables; Optical fiber sensors; Optical fibers; Rail transportation; Railroads; Railway engineering; Railways; Real time; Safety; Trains; Vibration; Vibrations; optical time-domain reflectometry (OTDR); railway safety; vibration measurement; Optical fiber sensor
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2014.2346760

It is essential to carry out real-time position and speed monitoring of trains to ensure the safety of railway operation. In this letter, the phase-sensitive optical-time-domain reflectometry (Φ-OTDR) is demonstrated to overcome the drawbacks of the track circuit, which is widely used and has the risk to be damaged by lightening, for the first time. A long sensing cable, buried nearby to two parallel railways, is used to detect the vibration signals generated by trains with Φ-OTDR and the real-time vibration signals of the trains are extracted/quantified by wavelet denoising. With the edge detection by normalized sliding variance, the operation status of two nearby trains, including their relative position and speed, are obtained over a 10.2-km measurement length in real time. This letter offers a new passive way for safety monitoring of railway operation.