On-line characterization of impacts on electrical train current collectors using integrated optical fiber grating sensor network

Abstract

A sensor network consisting of unified fiber grating based temperature and strain sensor pads has been developed for integration in carbon/aluminum composite current collector strips, and has been tested in electrical trains on commercial railways. The fiber optic sensor network measures value and position of both contact forces and impacts under real-time conditions, immediately at the high voltage location of the interface between overhead contact line and current collector.

Smart current collector—fibre optic hit detection system for improved security on railway tracks

“…The wavelength detection of the FBG sensor is based on a compact polychromator unit with an imaging diffractive grating. The linear photodiode array with 72 discrete elements is placed close to the focal plane of the home-made diffraction-grating array spectrometer (figure 3 of [7,8]). Using an spectrometer input fibre of appropriate diameter and numerical aperture, the beam shape of each of the FBG spectral reflection peaks can be tuned to obtain a Gaussian beam shape covering two respective photodiodes of the array.…”

“…We tested on the following tracks: Three examples are chosen to be presented in the following, additional examples are provided in [8].…”

“…They are installed immediately inside the CC to reduce disturbing mechanical interfaces and inertia (figure 1). Previous investigations on CCs with these so-called fibre Bragg gratings (FBGs) were published in [7,8,18]. An approach to use this sensor concept to measure the contact force is discussed in [1].…”

Optical Fibre Sensors: a Current Perspective

“…In the example of wind turbines the vibrational signals have been used to provide input to control systems to optimise the blade orientation and the angle of the generator system with respect to the prevailing wind. Fibre gratings have also been used in specialised structural evaluation projects associated with, for example, electric trains [14] where they have successfully monitored the mechanical response of new pantograph designs and vehicle induced movement of newly installed railway tracks.…”

Properties of Specialist Fibres and Bragg Gratings for Optical Fiber Sensors

“…The projected market size of optical fiber sensors generally is expected to exceed $US 1.6 billion in 2014, up from the 2007 figure of $US 235 million [1]. Grating technologies are increasingly pervasive within this market finding applications ranging from biomedical, chemical, and cosmetic [2][3][4][5][6] to structural health monitoring (SHM) of buildings, vehicles, aircraft, bridges, trains, and windmills [7][8][9][10][11][12][13][14][15][16][17][18][19]. Two important characteristics dominate the criteria of gratings for sensing applications: temperature and strain/pressure sensitivity, both of which are affected by the type of optical fibre and the performance parameters not only of the grating itself but also of the type of fibre and the required packaging.…”