Fiber Optic Sensing System for Monitoring of Current Collectors and Catenary of Railways Kerstin Schröder 1 , Manfred Rothhardt 1 , Wolfgang Ecke 1 , Uwe Richter 2 , André Sonntag 2 , Hartmut Bartelt 1 1 Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany 2 Eurailscout Inspection & Analysis b.v., Torellstr. 1, 10243 Berlin. Germany Summary Fiber optic sensors are excellent tools to use for monitoring purposes on high voltage current collectors. Because of their small cross section and electrical neutrality, they are easy to integrate into the current collector strip and are well specialized for detection of high-speed load events. Also the conventional contact force measurement with four force sensors below the collector strips can be simplified by using fiber optic force and acceleration sensors. Keywords: Force Sensors, Structural Health Monitoring, Current Collectors, Fiber Bragg Gratings Introduction This work aims at new needs for diagnostics on trains and electrical infrastructure arising from the deregulation and interoperability of the EU railway track. The contact between overhead contact lines (OCLs) and current collectors/pantographs is an interface between the newly established track and train operators. Permanent monitoring of the load conditions allows prediction of the resulting wear and helps to optimize service and repair cycles on the OCL. Some measurement techniques for OCL monitoring, such as contact force measurement, are already well established. Boundary conditions are defined in an European standard (EN 50317). Other techniques, for instance the detection of disturbances (misalignments or intruders), are still under development or under optimization. Measurements at the interface between OCLs and current collectors with electrical sensors are complex and prone to interferences due to the high electrical voltages and the strong changes of electric and magnetic fields. In contrast, fiber optic sensors, which have advantages as small and electrically immune devices, can easily be applied for such measurements. For this reason research is currently underway to utilize fiber optic sensors for monitoring purposes in current collectors or on OCLs, already in early stage ([1], [2], [3]). Fiber Bragg grating (FBG) sensors have the additional advantage that many sensor elements can be multiplexed along a single optical fiber, and the quantitative load result is derived from a spectral shift, which is immune to light intensity variations. Therefore, they are often the preferred kind of sensors for monitoring purposes on this interface ([4], [5]). Currently, such investigations are focused on the optimization of the sensors and their instrumentation. In this paper, results are reported from the investigation of two different measuring techniques: quantitative logging of fast hit events, and of the stationary acceleration-compensated contact force (Fig. 1). Fig. 1: Pantograph head with overhead contact line, sensitized collector strip carbon und aluminum part of the strip and force sensors below the collector strip. 18. GMA/ITG-Fachtagung Sensoren und Messsysteme 2016 697 DOI 10.5162/sensoren2016/P6.7