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 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 - 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 N2 - Reinforced concrete piles are used when structures are constructed on soft ground, because it is necessary to transfer the loads into deeper strata with a sufficient bearing capacity. Usually, static and dynamic pile tests are carried out in order to determine the pile’s behaviour and possible damages. The dynamic measurements can show the bearing behaviour and the structural integrity by using the theory of one-dimensional wave propagation. Commonly, the sensors are installed on the top of the pile head or embedded near the pile head. With the purpose of receiving more precise information about the pile features, now, a string of sensors is embedded at different levels of the pile. A fibre optic strain wave sensor has already been developed by Schallert. The sensor is based on the principle of the extrinsic Fabry-Perot interferometer and was already tested in laboratory and full-scale field tests with precast driven piles. It was possible to detect the introduced deformation caused by the static loading and the dilatational wave during dynamic low-strain as well as high-strain loading. Although the full-scale tests were successful, the high demands on the economy of the sensor required the optimisation of the sensor design. After laboratory tests with the optimised sensor, a cast-in-situ bored pile has been built at the BAM Test Site Technical Safety in Horstwalde, South of Berlin. In order to enable the comparison of the signals, additional fibre Bragg grating sensors, temperature sensors and resistance strain gauge sensors are embedded into the pile. In this paper, the optimised sensor and the setup of the cast-in-situ bored pile along with results of the conducted pile tests are shown together with an outlook on further field-tests in progress. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 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 - Lohrke, Heiko A1 - Kohlhoff, Harald A1 - Erdmann, Jessica A1 - Winkler, Nicolas P. A1 - Neumann, Patrick P. T1 - Combined GNSS/Visual Inter-Robot Tracking Method for Open-Path Gas Tomography N2 - Methane emissions are a significant environmental and safety concern, yet many gas tomography systems intended to measure them require manual alignment, reliable high-bandwidth links, or fiducials. We present a lightweight, fully autonomous framework enabling line-of-sight inter-robot Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurements without such constraints. A sensor robot equipped with a gimbal-mounted TDLAS unit tracks a reflector robot bearing an illuminated, color-controllable target. Coarse localization is achieved via RTK-GNSS, with vision-based fine tracking and passive time synchronization handled onboard. The system, based on off-the-shelf Pixhawk controllers and ArduPilot firmware, was validated in a 15m × 7m outdoor trial. Despite GNSS inaccuracies and deliberate occlusion by a methane-filled bag, the system retained lock, recovered from visual loss in under one second, and captured a 2800 ppm·m plume signature. These results demonstrate robust, scalable methane sensing for mobile gas tomography or standalone leak detection. Core components are released open-source to support future deployment. T2 - IEEE SENSORS 2025 CY - Vancouver, BC, Kanada DA - 19.10.2025 KW - Gas tomography KW - Tracking KW - Robot KW - Methane KW - TDLAS PY - 2025 SN - 979-8-3315-4467-6 DO - https://doi.org/10.1109/SENSORS59705.2025.11330519 SP - 1 EP - 4 PB - IEEE CY - Piscataway, NJ, USA AN - OPUS4-65615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -