TY - CONF A1 - Köppe, Enrico T1 - Magnetic field detection with an advanced FBG-based sensor device N2 - A high-performance fiber Bragg grating-based (FBG) sensor device for the detection of small magnetic fields has been developed. Based on a smart multilayer coating exposed over the physical length of the FBG, magnetic fields exhibited by rotating machine parts, power generators or current cable can easily be detected, analysed and evaluated. Consequently, this innovative, in-process and non-contact inspection method leads to an increase in quality and reliability of high-performing machine parts, devices and cables. The basic physical concept is based on a magnetostrictive multilayer coating system that strains the high-resolution FBG element. Subsequently, a fixed relationship between induced magnetic field and wavelength change of the FBG element forms the characteristic sensitivity curve. Intensive tests regarding the characterisation of the magnetic field FBG sensor have been carried out and its performance has been evaluated. T2 - EuroSensors XXX 2016 CY - Budapest, Hungary DA - 04.09.2016 KW - Strain KW - Fiber Bragg grating KW - Magnetostriction KW - Magnetic field PY - 2016 AN - OPUS4-37364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Frank A1 - Köppe, Enrico A1 - Daum, Werner T1 - Tracking deformation history in split Hopkinson pressure bar testing N2 - The stress vs. strain curve of materials is affected the rate of imposed straining. Among the methods for dynamic testing the technique known as 'split Hopkinson pressure bar' (SHPB) has evolved into the most widely used one to exert high-speed straining. The theory behind it comprises simple equations to compute stress and strain. The reliability of the strain analysis can be assessed by digital image correlation (DIC). The present results indicate that the visually observed strain is smaller than predicted by theory. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Digitale Bildkorrelation (DIC) KW - Dynamische Tests KW - Spannungs-Dehnungs-Kurve KW - Digital image correlation (DIC) KW - Dynamic testing KW - Split Hopkinson pressure bar (SHPB) KW - Stress-strain curve PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.017 SN - 2214-7853 VL - 3 IS - 4 SP - 1139 EP - 1143 PB - Elsevier CY - Oxford AN - OPUS4-34487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schadow, Florian A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Dohse, E. A1 - Köppe, Enrico T1 - Focusing air-coupled ultrasonic transducers based on ferroelectrets N2 - Rising importance of composite lightweight structures in aircraft and automobile industries increases the demand on reliable non-destructive testing methods for these structures. Air-coupled ultrasonic testing emerged to suit these requirements as it does not require any liquid coupling medium. In conventional air-coupled ultrasonic transducers, matching layers are used in order to decrease the impedance mismatch between transducer and air. Matching layers can be omitted by using ferroelectrets, which are charged cellular polymers having ferroelectric and piezoelectric properties. Especially a low Young’s modulus, low density and low sound velocity of cellular polypropylene (cPP) are properties being required for well-matched air-coupled ultrasonic transducers. In our contribution we show recent enhancements of cPP transducers resulting in focused sound fields and thus improved lateral sensitivity. The influence of different transmitter apertures was evaluated using measurements of the emitted sound field. Further we show a transmission of a test specimen of carbon-fiber-reinforced plastic (CFRP) containing artificial damages. Results of focused transducers were compared to planar ferroelectret transducers, as well as to conventional air-coupled transducers. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - München, Germany DA - 13.06.2016 KW - Air-coupled ultrasonic testing KW - Ferroelectrets KW - Cellular polypropylene KW - Focused sound fields KW - Focused transducers PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355116 UR - http://www.ndt.net/search/docs.php3?showForm=off&id=19453 SP - 1 EP - 8 AN - OPUS4-35511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Vivien A1 - Köppe, Enrico A1 - Hofmann, Detlef A1 - Westphal, Anja A1 - Sahre, Mario A1 - Gong, Xin A1 - Bartholmai, Matthias A1 - Beck, Uwe T1 - Magnetic field detection with an advanced FBG-based sensor device N2 - A high-performance fiber Bragg grating-based (FBG) sensor device has been developed for the detection of small magnetic fields. Based on a smart multilayer jacket around the fibre over the physical length of the FBG, magnetic fields generated by rotating machine parts, power generators or power cable can be easily detected, analysed and evaluated. Consequently, this innovative, on-line and non-contact inspection method results in an increase in quality and reliability of high-performing machine parts, devices and cables. The basic physical principle is based on a magnetostrictive multilayer system that strains the high-resolution FBG element in presence of magnetic fields. Subsequently, a fixed relationship between induced magnetic field and wavelength change of the FBG element describes the characteristic sensitivity curve. Intensive tests regarding characterisation of this magnetic field FBG sensor have been carried out and its performance has been evaluated. T2 - 30th Eurosensors Conference, EUROSENSORS 2016 CY - Budapest, Hungary DA - 04.09.2016 KW - Fiber Bragg grating KW - Magnetostriction KW - Strain KW - Magnetic field PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-376703 DO - https://doi.org/10.1016/j.proeng.2016.11.445 SN - 1877-7058 VL - 168 SP - 1270 EP - 1274 PB - Elsevier Ltd. AN - OPUS4-37670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Frank A1 - Köppe, Enrico A1 - Daum, Werner T1 - Tracking deformation history in split Hopkinson pressure bar testing N2 - The stress vs. strain curve of materials is affected the rate of imposed straining. Among the methods for dynamic testing the technique known as 'split Hopkinson pressure bar' (SHPB) has evolved into the most widely used one to exert high-speed straining. The theory behind it comprises simple equations to compute stress and strain. The reliability of the strain analysis can be assessed by digital image correlation (DIC). The present results indicate that the visually observed strain is smaller than predicted by theory. T2 - 32nd Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Split Hopkinson pressure bar (SHPB) KW - Digital image correlation (DIC) KW - Digitale Bildkorrelation (DIC) KW - Dynamic testing KW - Dynamische Tests KW - Stress-strain curve KW - Spannungs-Dehnungs-Kurve PY - 2015 SN - 978-80-554-1094-4 SP - 174 EP - 175 PB - University of Zilina, Slovakia CY - Zilina AN - OPUS4-35656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Subaric-Leitis, Andreas A1 - Wilk, Tabea T1 - Auswertung der Messunsicherheit eines Multisensorsystems zur Weg- und Positionsbestimmung sich bewegender Objekte in Gebäuden N2 - In den letzten Jahren ist die Bestimmung der Position eines sich bewegenden Objektes eine immer interessanter werdende Information geworden. Die aktuelle Position oder der zurückgelegte Weg wird mittels miniaturisierter integrierter 3D-Sensoren bestimmt. Durch die Integration dieser Sensoren in moderne Smartphones oder in spezielle robuste Hardware sind die Anwendungsgebiete vielseitig. Die ermittelte Position innerhalb von Gebäuden ist dabei für den Kaufmann innerhalb eines Shoppingcenters aber auch für den Feuerwehrmann im Einsatz wichtig. Für den Kaufmann bedeutet es durch gezielte Angebote potenzielle Kunden anzusprechen und damit seinen Umsatz zu steigern. Für den Einsatzleiter der Feuerwehr ist die genaue Position seiner Feuerwehrmänner im Einsatz lebensrettend und bietet damit eine zusätzliche Sicherheit für die Einsatzkraft. Das hier vorgestellte Multisensorsystem, allgemein als Inertialsystem bezeichnet, und das darauf angewendete Verfahren zur Positionsbestimmung wird in diesem Bericht vorgestellt und näher beschrieben. Die systematischen und zufälligen Messunsicherheitsbeiträge des Inertialsystems und deren Auswirkungen auf die Bestimmung der aktuellen Position und somit auf den resultierenden zurückgelegten Weg werden erörtert. T2 - 7. VDI-Fachtagung Messunsicherheit 2015 - Messunsicherheit praxisgerecht bestimmen - Prüfprozesse in der industriellen Praxis CY - Braunschweig, Germany DA - 19.11.2015 PY - 2015 SN - 978-3-18-092269-0 SN - 0083-5560 N1 - Serientitel: VDI-Berichte – Series title: VDI-Berichte IS - 2269 SP - 173 EP - 181 PB - VDI-Verl. AN - OPUS4-35118 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Edel, M. A1 - Köppe, Enrico T1 - An advanced method for pedestrian dead reckoning using BLSTM-RNNs N2 - Location estimation and navigation, especially on smartphones has shown great progress in the past decade due to its low cost and ability to work without additional infrastructure. However, a challenge is the positioning, both in terms of step detection, step length approximation as well as heading estimation, which must be accurate and robust, even when the use of the device is varied in terms of placement or orientation. In this paper, we propose a scheme for retrieving relevant information to detect steps and to estimate the correct step length from raw inertial measurement unit (IMU) data. This approach uses Bidirectional Long Short-Term Memory Recurrent Neural Networks (BLSTM-RNNs). Designed to take contextual information into account, the network can process data gathered from different positions, resulting in a system, which is invariant with respect to transformation and distortions of the input patterns. An experimental evaluation on a dataset produced from 10 individuals demonstrates that this new approach achieves significant improvements over previous attempts and increase the current state-of-the-art results even in the presence of variations and degradations. We achieved a mean classification rate of 98.5% and a standard deviation of 0.70 for 10000 different test sequences and an average error of 1.45% regarding the step length. Thus is the best result on the task gathered in the experiments compared with competing techniques. T2 - IPIN 2015 - 6th International conference on indoor positioning and indoor navigation CY - Banff, Alberta, Canada DA - 13.10.2015 KW - Indoor positioning KW - Inertial tracking KW - Dead reckoning KW - Deep learning KW - Machine learning PY - 2015 SN - 978-1-4673-8402-5 DO - https://doi.org/10.1109/IPIN.2015.7346954 SN - 2162-7347 SP - Paper 1570149259, 1 EP - 6 AN - OPUS4-35119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Daum, Werner A1 - Gong, Xin A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Schukar, Vivien A1 - Westphal, Anja A1 - Sahre, Mario A1 - Beck, Uwe T1 - New self diagnostic fiber optical sensor technique for structural health monitoring N2 - Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 PY - 2015 SN - 978-80-554-1094-4 SP - 1 EP - 2 CY - Zilina AN - OPUS4-35173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico T1 - Auswertung der Messunsicherheit eines Multisensorsystems zur Wege- und Positionsbestimmung sich bewegender Objekte in Gebäuden T2 - VDI/VDE-Mess- und Automatisierungstechnik, Messunsicherheit praxisgerecht bestimmen, Prüfprozesse in der industriellen Praxis CY - Braunschweig, Germany DA - 2015-11-19 PY - 2015 AN - OPUS4-35032 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Hofmann, Detlef A1 - Daum, Werner T1 - Absolut messendes EFPI-Messsystem N2 - In diesem Paper wird ein absolut messendes faseroptisches Messsystem zur Bestimmung des Gap-Abstandes von niedrig reflektierenden losen und festen extrinsischer Fabry-Pérot Interferometer (EFPI) vorgestellt. Die häufigste Methode zur Bestimmung von Dehnungen oder Bewegungen durch EFPI-Sensoren ist eine kontinuierliche relative Ermittlung einer Veränderung mit einer nachträglichen Auswertung. Unterbrechungen in der Datenerfassung oder Fehler bei der Interferenzstreifen-Auswertung führen zu einer nicht abschätzbaren Messunsicherheit. Damit war es bis dato nicht möglich, eine absolute Veränderung von eingesetzten EFPI-Sensoren zu bestimmen. Mit dem an der BAM entwickelten Verfahren, ist dies jetzt möglich, die absolute Veränderung zu bestimmen. Dieses System namens 'EFPI-Scan' wird in dem Papier dargestellt werden. T2 - Sensoren und Messsysteme 2014 - 17. ITG/GMA-Fachtagung CY - Nürnberg, Germany DA - 03.06.2014 PY - 2014 SN - 978-3-8007-3622-5 SN - 0932-6022 N1 - Serientitel: ITG-Fachbericht – Series title: ITG-Fachbericht VL - 250 SP - P16.2, 1 EP - 3 PB - VDE Verlag GmbH AN - OPUS4-32644 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -