Diagnosis of Rail Circuits by Means of Fiber-Optic Cable

Abstract

For the safety of train traffic, the most important step is the introduction of a new type of rail circuits – fiber-optic rail circuits. The high sensitivity of the fiber optic cable to external influences (deformation, vibration) is an important property both for detection mechanical damage of rails and wheel sets and positioning the rolling stock. The branches of the fiber-optical cable through mechanical amplifiers perform both the functions of the information perception element - the sensor and the conducting channel of the transmitted information. Using OTDR (Optical Time Domain Reflectometer), based on the analysis of the backscattered light signal, the form of the physical impact that caused the bending is determined. By the time between the emission of the light signal and the receiving of the backscattered signal, position of damage is calculated. The novel method offered in the article gives us the opportunity to detect dropped or damaged wheel-set in the rolling stock and it helps us to detect the station-to-station block occupation of the rolling stock. It also gives us the possibility to ascertain precise location of occupation of the station-to-station block by the rolling stock and to determine a place of the worn dropped or damaged rail. By means of this method, we can identify the spoiled rolling stock and detect overheated boxes in the rolling stock. This method also allows us to control the load on the rolling stock axles. The paper illustrates the schematic diagram and the algorithm of the proposed system developed by the authors.