TY - CONF A1 - Schilder, Constanze A1 - Kohlhoff, Harald A1 - Hofmann, Detlef A1 - Habel, Wolfgang ED - Boller, C. T1 - Structure-integrated fibre-optic strain wave sensor for pile testing and monitoring of reinforced concrete piles T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 (Proceedings) T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 2012-07-03 PY - 2012 SN - 978-3-940283-41-2 VL - 1 SP - 523 EP - 530 CY - Berlin AN - OPUS4-26279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Werner, Klaus-Dieter A1 - Erdmann, Jessica A1 - Eggeringhaus, Bärbel A1 - Kammermeier, Michael A1 - Schukar, Marcus A1 - Basedau, Frank A1 - Bartholmai, Matthias A1 - Lazik, D. A1 - Ebert, Sebastian T1 - Setup of a large scale soil test field with CO2 injection for testing a novel distributed subsurface monitoring system for gas storage areas T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) N2 - One of the main unsolved issues of under-ground storages for, e.g., CO2, H2, and natural gas is the comprehensive surveillance of these areas with reasonable effort and costs. Conventional sensors (e.g., soil air probes or borehole probes), however, can only be used for punctual or locally limited measurements; further their application can cause structural influences (invasive application). In this paper, we describe in detail the setup of a CO2 injection soil test field. This test field will be used to enhance and validate an innovative ap-proach for distributed subsurface monitoring of gas storage areas. To the author’s knowledge, this is the first time that, for this purpose, a test field is built in an application relevant scale. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 KW - Large scale soil test field KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fiber optical sensing PY - 2014 SN - 978-3-00-046740-0 SP - 238 EP - 239 AN - OPUS4-31527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kohlhoff, Harald T1 - Determining the spatial form of rock samples in triaxial testing cells - a fiber-optic measurement concept T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) N2 - Rocks and stone are common construction materials in geomechanics. Great difficulties arise from the inhomogeneous nature of the mechanicalhydraulic materials behavior and their materials properties. However, well-tried mathematically based engineering concepts are only valid if reliable figures of the materials properties are known. One of the important measurement tools is the triaxial fest cell. Essentially used for conducting crack and creep tests, they apply mechanical pressure to the front sides of a cylindrical rock sample. Additionally, the rock sample is exposed to a triaxial pressure by creating a hydraulic pressure inside the test cell to simulate the original environmental conditions which can be found at the site where the rock samples were extracted. Deformation measuring sensors inside the test cell are exposed to those extreme conditions as well; sensor designs have to withstand pressures up to 2000 bar. In this work, a novel fiber based deformation sensor is presented in detail. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 PY - 2014 SN - 978-3-00-046740-0 SP - 126 EP - 127 AN - OPUS4-31727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüllmann, Dino A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. ED - Bársony, I. ED - Zolnai, Z. ED - Battistig, G. T1 - Embedded control of a PMSM servo drive without current measurements T2 - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016 N2 - A permanent-magnet synchronous motor (PMSM) servo drive for lightweight robotic platforms that have a high torque demand at low rotational speeds has been developed. First, a current-independent torque controller is derived and cascaded with a speed and position controller, while merely an encoder is used as a sensor device in combination with a speed estimator. Finally, the speed estimator output is compared to gyroscope measurements and the overall functioning is verified on a real system. T2 - 30th Eurosensors Conference - Eurosensors 2016 CY - Budapest, Hungary DA - 04.09.2016 KW - BLDC KW - PMSM KW - Motor control KW - Servo drive KW - Optical incremental encoder PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-388973 DO - https://doi.org/10.1016/j.proeng.2016.11.487 SN - 1877-7058 VL - 168 SP - 1671 EP - 1675 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-38897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Johann, Sergej A1 - Kohlhoff, Harald A1 - Gawlitza, Kornelia A1 - Bell, Jérémy A1 - Mansurova, Maria A1 - Tiebe, Carlo A1 - Bartholmai, Matthias T1 - Semi-automatic Gas Measurement Device Based on Fluorescent Multi-gas Sensors T2 - Proceedings of the IEEE Sensors 2019 N2 - This paper describes the development of a semi-automatic gas measurement device presenting potentially a broad range of applications, noteworthy in the agricultural sector. Non-reversible fluorescent molecular sensors were designed and syn-thesized. Upon, integration into a hydrogel matrix with an optimal ratio of co-solvents, the sensors reacting selectively to ammonia were illuminated by excitation light to produce a concentration-correlated fluorescence emission. An automated mechanical-elec-trical device initiates a given gas mixture and thus simulates con-centrations similar to a threshold value. The aim of this project is to develop a sensor or a low-cost method which can monitor low concentrations of harmful gases and aid in their elimination or regulation in livestock housing, barns or stables. T2 - IEEE Sensors 2019 CY - Montreal, Canada DA - 27.10.2019 KW - gas analysis KW - fluorescence KW - embedded sensor KW - spectroscopy KW - environment KW - agricultural economy PY - 2019 SN - 978-1-7281-1634-1 SP - 88 EP - 92 PB - IEEE AN - OPUS4-49506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Johann, Sergej A1 - Mansurova, Maria A1 - Kohlhoff, Harald A1 - Gkertsos, Aris A1 - Neumann, Patrick P. A1 - Bell, Jérémy A1 - Bartholmai, Matthias T1 - Wireless Mobile Sensor Device for in-situ Measurements with Multiple Fluorescent Sensors T2 - Proceedings of the IEEE Sensors 2018 N2 - This paper describes a wireless mobile prototype able to perform optical measurements by means of a miniatur-ized spectrometer for low light analysis, e.g. fluorescent sensors. Evaluations, calculations, calibration management and result display are performed by a computer or a standard tablet. The device was designed primarily to detect traces of oil in drinking or ground water and for the analyses of crude oils. However, it can also address a wide range of fluorescent sensors. The fast and user-friendly inspection of water quality or oil properties, as well as the adaptability and mobility, make the device attractive for a variety of users. Further application areas could be easily imple-mented by adapting the optics and the software (database, data processing and calibration plots, etc.) T2 - IEEE Sensors 2018 CY - New Delhi, India DA - 28.10.2018 KW - Wireless mobile sensor device KW - Fluorescent sensor KW - Embedded system KW - Water quality KW - Oil PY - 2018 SN - 978-1-5386-4707-3 SP - 1067 EP - 1070 PB - IEEE CY - New Delhi, India AN - OPUS4-46556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Hüllmann, Dino A1 - Krentel, Daniel A1 - Kluge, Martin A1 - Kohlhoff, Harald A1 - Lilienthal, A. J. T1 - Gas Tomography Up In The Air! T2 - Proceedings of the IEEE Sensors 2018 N2 - In this paper, we present an autonomous aerial robot to reconstruct tomographic 2D slices of gas plumes in outdoor environments. Our platform, the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS) combines a lightweight Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile octocopter. The TDLAS sensor provides integral gas concentration measurements but no information regarding the distance traveled by the laser diode's beam or the distribution of the gas along the optical path. We complemented the set-up with a laser rangefinder and apply principles of Computed Tomography (CT) to create a model of the spatial gas distribution from these integral concentration measurements. To allow for a rudimentary ground truth evaluation of the applied gas tomography algorithm, we set up a unique outdoor test environment based on two 3D ultrasonic anemometers and a distributed array of 10 infrared gas transmitters. We present first results showing the 2D plume reconstruction capabilities of the system under realistic conditions. T2 - IEEE Sensors 2018 CY - New Delhi, India DA - 28.10.2018 KW - Aerial robot KW - TDLAS KW - Gas tomography KW - Plume PY - 2018 SN - 978-1-5386-4707-3 SP - 396 EP - 398 PB - IEEE AN - OPUS4-46477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Kohlhoff, Harald A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Habel, Wolfgang A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Georgi, Steven A1 - Herten, M. ED - Jaroszewicz, L.R. T1 - Static and dynamic pile testing of reinforced concrete piles with structure integrated fibre optic strain sensors T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors (Proceedings) N2 - Static and dynamic pile tests are carried out to determine the load bearing capacity and the quality of reinforced concrete piles. As part of a round robin test to evaluate dynamic load tests, structure integrated fibre optic strain sensors were used to receive more detailed information about the strains along the pile length compared to conventional measurements at the pile head. This paper shows the instrumentation of the pile with extrinsic Fabry-Perot interferometers sensors and fibre Bragg gratings sensors together with the results of the conducted static load test as well as the dynamic load Tests and pile integrity tests. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Static load test KW - Dynamic load test KW - Pile integrity test KW - Extrinsic Fabry-Perot interferometer KW - Fibre Bragg grating KW - Structure integrated sensor KW - Fibre optic strain sensor PY - 2013 SN - 978-0-81949-634-8 DO - https://doi.org/10.1117/12.2026813 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 700 EP - 703 AN - OPUS4-28854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -