TY - GEN A1 - Köppe, Enrico A1 - Augustin, D. A1 - Köppe, Tabea A1 - Subaric-Leitis, Andreas A1 - Liers, A. A1 - Schiller, J. ED - Gartner, G. ED - Huang, H. T1 - Application of the inertial navigation system 3D-self-calibration-method for the minimization of the measurement uncertainty N2 - For the accuracy of inertial navigation systems for indoor localization it is important to get high quality sensor data of the multi-sensor system. This can be realized using high quality sensors or the developed 3D-self-calibration-method for low cost sensors. Based on the calibration procedure of the accelerometer (ACC) and the magnetic field sensor (MAG), the additional integration of the gyroscope (GYRO) leads to a reduction of the indoor positioning error. This improves both the approximation for the accelerometer, the magnetic field sensor and the gyroscope so that the standard deviation of a single sensor is minimized. There are errors in the whole system. To determine these error sources it is important to define the measurement uncertainty. In this paper it is presented that the measurement uncertainty can be reduced by the application of the developed 3D-self-calibration method. T2 - 11th International Symposium on Location Based Services CY - Vienna, Austria DA - 26.11. 2014 KW - 3D sensor KW - 3D calibration method KW - Indoor localization KW - Measurement uncertainty PY - 2014 SN - 978-3-319-11878-9 DO - https://doi.org/10.1007/978-3-319-11879-6_8 SN - 1863-2246 N1 - Geburtsname von Köppe, Tabea: Wilk, T. - Birth name of Köppe, Tabea: Wilk, T. N1 - Serientitel: Lecture Notes in Geoinformation and Cartography (LNG&C) – Series title: Lecture Notes in Geoinformation and Cartography (LNG&C) SP - 105 EP - 117 PB - Springer AN - OPUS4-32430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Liers, A. A1 - Schiller, J. T1 - Radio-based multi-sensor system for person tracking and indoor positioning N2 - Sensor based person tracking is a challenging topic. The main objective is positioning in areas without GPS connection, i.e. indoors. A research project is carried out at BAM, Federal Institute for Materials Research and Testing, to develop and to validate a multi-sensor system for 3D localization. It combines body motion sensing and a guard system for the tracking and recording of the status of persons. The so named BodyGuard system was designed for sensor-based monitoring and radio-based transmission of the movement of a person. Algorithms were developed to transform the sensor data into a spatial coordinate. This paper describes how the BodyGuard system operates, which main components were used in the system, how the individual sensor data are converted into 3D motion data, with which algorithms the individual sensors are processed, how individual errors are compensated and how the sensor data are merged into a 3D Model. Final objective of the BodyGuard system is to determine the exact location of a person in a building, e.g. during fire-fighting operations. T2 - WPNC '12 - 9th Workshop on positioning, navigation and communication 2012 CY - Dresden, Germany DA - 2012-03-15 KW - Wireless sensor network (WSN) KW - Embedded systems KW - Sensor calibration and validation KW - Person tracking KW - Inertial navigation system KW - Inertial measurement unit PY - 2012 IS - PS 11 SP - 1 EP - 7 CY - Dresden AN - OPUS4-26028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prager, Jens A1 - Gravenkamp, Hauke A1 - Rahman, Mehbub-Ur A1 - Köppe, Enrico T1 - Einsatz geführter Wellen für die Ultraschallprüfung N2 - Der Einsatz geführter Wellen für die zerstörungsfreie Prüfung mit Ultraschall eröffnet neue Möglichkeiten, räumlich ausgedehnte Bauteile mit begrenzter Zugänglichkeit auf ihre Integrität zu prüfen und gewinnt daher zunehmend an Bedeutung. Dieser Artikel behandelt die physikalischen Grundlagen der Schallausbreitung. Deren Verständnis bildet die Grundlage für die Entwicklung geeigneter Prüfsysteme. An Beispielen werden verschiedene Möglichkeiten zur Simulation der Schallausbereitung vorgestellt. Aktuelle Lösungsansätze zur Prüfung von plattenförmigen Strukturen und von Rohrleitungen werden beschrieben, wobei besonders auf die Sensortechnik und die speziellen Anforderungen an die Prüfhardware eingegangen wird. ----------------------------------------------------------------------------------------------------------------------------------- Guided waves are widely used for non-destructive testing using ultrasound. Recently, the method has become increasingly important for integrity tests of spatially extended components with limited accessibility. This article discusses the basic physics of the sound propagation of guided waves. Their understanding forms the basis for the successful development of adapted inspection systems. Examples for simulating the wave propagation using different methods are presented. Current approaches for the inspection of plate-like structures and pipelines are described with focus on sensor technology and the specific requirement on the test hardware. KW - Zerstörungsfreie Prüfung KW - Geführte Wellen KW - Ultraschallprüfung KW - Non-destructive evaluation KW - Guided waves KW - Ultrasound PY - 2012 DO - https://doi.org/10.1524/teme.2012.0168 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 79 IS - 5 SP - 251 EP - 261 PB - Oldenbourg CY - München AN - OPUS4-26206 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Prager, Jens T1 - Device concept for the generation of guided waves for early damage detection N2 - In this study a method for early damage detection is investigated based on the directed excitation and measuring of Lamb waves (guided waves). The objective is to make a statement about the practicability of a Lamb wave generator (LWG) and about the application relevant parameters (specimen materials and dimensions, wave characteristics, excitation, transmission und reflection). Guided waves enable an effective differentiation of structural and defective indications as well as a classification of different defect types. For the investigations, a LWG was developed which combines the advantages of the single excitation of a piezoelectric actuator and the possibility of a group excitation. Algorithms were developed to identify and analyze damage patterns (cracks, wholes, weakening). T2 - Eurosensors XXVI CY - Kraków, Poland DA - 2012-09-09 KW - Lamb wave KW - Guided wave KW - DDS KW - SHM KW - Early damage detection PY - 2012 DO - https://doi.org/10.1016/j.proeng.2012.09.363 SN - 1877-7058 VL - 47 SP - 1185 EP - 1188 PB - Elsevier AN - OPUS4-27552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Köppe, Enrico A1 - Prager, Jens ED - Boller, C. T1 - Early damage detection of structural defects using guided waves N2 - Limited access to the object of relevance is often an essential problem in testing routines, e.g. for non-destructive testing of industry facilities or components of means of transportation. The presented project is about the development of a non-destructive testing method for application over great distances (up to 100 m). The method is based on directed excitation and measuring of Lamb waves (guided waves). It enables an effective differentiation of structural and defective indications as well as a classification of different defect types. The advantage of guided waves is the ability of propagation over great distances. This offers innovative possibilities for the investigation of large or difficult to access constructions. The testing method can be helpful in a broad variety of applications. It is useable for the characterization of plane or cylindrical, thin-walled surfaces of metal or fiber laminated materials. Particularly the investigation of aircraft wings and other aerospace components as well as the investigation of pipelines are addressed fields of application. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 KW - Lamb-waves KW - Ultrasound KW - Non-destructive evaluation KW - Early-damage-detection KW - Structural health monitoring PY - 2012 SN - 978-3-940283-41-2 VL - 2 SP - 1471 EP - 1478 CY - Berlin AN - OPUS4-26240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Augustin, D. A1 - Liers, A. A1 - Schiller, J. T1 - Self-calibration-method for an inertial navigation system with three 3D sensors N2 - Inertial Navigation Systems with three 3D sensors are used to localize moving persons. The accuracy of the localization depends on the quality of the sensor data of the multi-sensor system. In order to improve the accuracy, a self-calibration process based on the automatic 3D calibration was developed. Based on the calibration procedure of the accelerometer (ACC) and the magnetic field sensor (MAG), the additional integration of the gyroscope (GYRO) leads to a reduction of the indoor positioning error. This improves both the approximation for the accelerometer and the magnetic field sensor so that the standard deviation of a single sensor is minimized. A new calibration procedure of the gyroscope and the accuracy improvement of the localization of a moving person are presented. T2 - ISISS 2014 - 1st IEEE International Symposium on Inertial Sensors and Systems CY - Laguna Beach, CA, USA DA - 25.02.2014 KW - Global Positioning System KW - Accelerometers KW - Calibration KW - Gyroscopes KW - Inertial navigation KW - Magnetic field measurement KW - Magnetic sensors KW - Sensor fusion KW - 3D sensor KW - ACC KW - GYRO KW - MAG KW - Accelerometer KW - Automatic 3D calibration KW - Gyroscope KW - Indoor positioning error reduction KW - Inertial navigation system KW - Magnetic field sensor KW - Moving person localization KW - Multisensor system KW - Self-calibration-method PY - 2014 SN - 978-1-4799-0915-5 DO - https://doi.org/10.1109/ISISS.2014.6782522 SP - 93 EP - 96 AN - OPUS4-32428 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 - 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 - JOUR A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Daum, Werner A1 - Gong, Xing 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 KW - Self-diagnostic fiber optical sensor KW - Magnetostrictive metal coating KW - Magnetic field KW - Fiber bragg grating PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.038 SN - 2214-7853 VL - 3 IS - 4 SP - 1009 EP - 1013 AN - OPUS4-37131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Schadow, Florian A1 - Köppe, Enrico A1 - Dohse, Elmar ED - Chimenti, D. E. ED - Bond, L. J. T1 - Focusing of ferroelectret air-coupled ultrasound transducers N2 - Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers. T2 - 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Minneapolis, Minnesota, USA DA - 26.07.2015 KW - Ferroelectret KW - Transducer KW - Air-coupled KW - Ultrasonic KW - Focusing PY - 2016 SP - 080001 PB - AIP Publishing CY - Melville, NY, USA AN - OPUS4-35955 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -