TY - CONF A1 - Winkler, Nicolas P. A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Erdmann, Jessica A1 - Schaffernicht, Erik A1 - Lilienthal, Achim J. T1 - Development of a Low-Cost Sensing Node with Active Ventilation Fan for Air Pollution Monitoring N2 - A fully designed low-cost sensing node for air pollution monitoring and calibration results for several low-cost gas sensors are presented. As the state of the art is lacking information on the importance of an active ventilation system, the effect of an active fan is compared to the passive ventilation of a lamellar structured casing. Measurements obtained in an urban outdoor environment show that readings of the low-cost dust sensor (Sharp GP2Y1010AU0F) are distorted by the active ventilation system. While this behavior requires further research, a correlation with temperature and humidity inside the node shown. T2 - SMSI 2021 Conference: Sensor and Measurement Science International CY - Online meeting DA - 03.05.2021 KW - Wireless sensing node KW - Air pollution KW - Sensor network KW - Environmental monitoring PY - 2021 DO - https://doi.org/10.5162/SMSI2021/D3.5 VL - 2021 SP - 260 EP - 261 AN - OPUS4-52607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkler, Nicolas P. A1 - Johann, Sergej A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. T1 - Revisiting Environmental Sensing Nodes: Lessons Learned and Way Forward N2 - Setting up sensors for the purpose of environmental monitoring should be a matter of days, but often drags over weeks or even months, preventing scientists from doing real research. Additionally, the newly developed hardware and software solutions are often reinventing existing wheels. In this short paper, we revisit the design of our environmental sensing node that has been monitoring industrial areas over a span of two years. We share our findings and lessons learned. Based on this, we outline how a new generation of sensing node(s) can look like. T2 - SMSI 2023 Conference Sensor and Measurement Science International CY - Nuremberg, Germany DA - 08.05.2023 KW - Sensing node KW - Sensor network KW - Environmental monitoring KW - Low-cost KW - LoRaWAN PY - 2023 SN - 978-3-9819376-8-8 DO - https://doi.org/10.5162/SMSI2023/C5.1 SP - 173 EP - 174 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-57454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Johann, Sergej A1 - Erdmann, Jessica A1 - Winkler, Nicolas P. ED - Kourkoulis, S. K. T1 - The RASEM System: A Technical Overview N2 - Occupational health is an important topic, especially in industry, where workers are exposed to airborne by-products (e.g., dust particles and gases). Therefore, continuous monitoring of the air quality in industrial environments is crucial to meet safety standards. For practical and economic reasons, high-quality, costly measurements are currently only carried out sparsely, both in time and space, i.e., measurement data are collected in single day campaigns at selected locations only. The project “Robot-assisted Environmental Monitoring for Air Quality Assessment in Industrial Scenarios” (RASEM) addresses this issue by bringing together the benefits of both – low- and high-cost – measuring technologies enabling costefficient long-term air quality monitoring in realtime: A stationary network of low-cost sensors that is augmented by mobile units carrying high-quality sensors. By mapping the distribution of gases and particles in industrial environments with the proposed RASEM system, measures can be identified to improve on-site working conditions much faster than using traditional methods. In this paper, we detail the technical aspects of RASEM and introduce the mobile platforms used. T2 - 38th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Poros, Greece DA - 20.09.2022 KW - RASEM KW - Dust sensor KW - Low-cost KW - Sensor network KW - Ground Robot KW - Aerial Robot PY - 2022 SP - 1 EP - 2 CY - Athens, Greece AN - OPUS4-55915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter A1 - Kohlhoff, Harald A1 - Helmerich, Rosemarie A1 - Daum, Werner ED - Aulova, Alexandra ED - Rogelj Ritonja, A. ED - Emri, I. T1 - Long-Term measurement of vertical displacements at the outer concrete bridges of the Berlin Main Station N2 - Berlin Main Station is the largest multi-level station in Europe. Its daily passenger number amounts to over 300.000. Structures built for such a large number of people require a high-level safety standard. The station was built on the inner city site of the historic Lehrter Bahnhof. The conditions for building and start of operation were challenging by several reasons. The typical sandy ground with a high level of groundwater makes the permanent static stability of such a complex structure difficult. Several completed, ongoing, and planned construction activities in the immediate vicinity of the station influence the ground settlement of the whole area. On basis of the structural design an impact prediction was calculated, which expected certain vertical displacements particularly between the single columns of the outer concrete bridges of the building. These columns support the glass roof construction, which only allows a defined limit of displacement. In order to avoid damage, a concept for monitoring and adjusting potentially occurring displacements was developed for installation at the outer bridges of the station. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Berlin Main Station KW - Differential displacements KW - Hydraulic levelling system KW - Laser-based displacement measuring system KW - Monitoring KW - Strain measurements PY - 2016 SN - 978-961-94081-0-0 SP - 166 EP - 167 CY - Ljubljana AN - OPUS4-37646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüllmann, Dino A1 - Kohlhoff, Harald A1 - Erdmann, Jessica A1 - Neumann, Patrick P. ED - Aulova, Alexandra ED - Rogelj Ritonja, A. ED - Emri, I. T1 - Current-independent torque control of PMSM servo drives N2 - A permanent-magnet synchronous motor (PMSM) is controlled using measurements from a digital, optical incremental encoder. The motor speed is estimated from these measurement. Basic performance results are presented. T2 - 33rd Danubia Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - BLDC KW - PMSM KW - Motor control KW - Servo drive PY - 2016 SN - 978-961-94081-0-0 SP - 172 EP - 173 PB - Narodna in univerzitetna knjižnica CY - Ljubljana, Slovenia AN - OPUS4-37813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Niels A1 - Hüllmann, Dino A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. ED - Cosmi, F. T1 - A concept for an aerial-based landfill monitoring system N2 - Aerial based robots constitute a safe and suitable approach to remote gas-sensing. This paper describes a new concept , incorporating existing UAVs and newly developed gas sensors. The presented autonomous system is able to perform gas source localization and gas distribution mapping. T2 - 34th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Gassensor KW - Multicopter KW - UAV KW - Olfaction PY - 2017 SN - 978-88-8303-863-1 SP - 179 EP - 181 PB - University of Trieste, Italy CY - Trieste, Italy AN - OPUS4-42122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Detlefsen, Malte A1 - Hüllmann, Dino A1 - Kohlhoff, Harald ED - Cosmi, Francesca T1 - A low-cost cable-suspended parallel manipulator for testing 3D olfaction algorithms N2 - Cable-suspended parallel manipulators have been a topic of research for multiple decades and called special attention in the fields of simulations. However, they are also well-suited for the simple evaluation of aerial-based mobile robot olfaction (MRO) algorithms, such as gas source localization and gas distribution mapping. Based on an open source framework for 3D printers, we designed a low-cost underconstrained, cable-suspended parallel manipulator. Computations are carried out purely on an Atmel ATmega2560 microcontroller. T2 - 34rd Danubia - Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Cable-suspended parallel manipulator KW - 3D KW - Mobile Robot Olfaction PY - 2017 SN - 978-88-8303-863-1 SP - 171 EP - 172 CY - Trieste AN - OPUS4-42316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüllmann, Dino A1 - Paul, Niels A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. A1 - Lilienthal, A. J. ED - Eberhardsteiner, J. ED - Růžička, M. ED - Cosmi, F. T1 - Measuring rotor speed for wind vector estimation on multirotor aircraft N2 - For several applications involving multirotor aircraft, it is crucial to know both the direction and speed of the ambient wind. In this paper, an approach to wind vector estimation based on an equilibrium of the principal forces acting on the aircraft is shown. As the thrust force generated by the rotors depends on their rotational speed, a sensor to measure this quantity is required. Two concepts for such a sensor are presented: One is based on tapping the signal carrying the speed setpoint for the motor controllers, the other one uses phototransistors placed underneath the rotor blades. While some complications were encountered with the first approach, the second yields accurate measurement data. This is shown by an experiment comparing the proposed speed sensor to a commercial non-contact tachometer. T2 - 34th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Wind vector estimation KW - Rotor speed KW - UAV KW - Tachometer PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S2214785318321114 DO - https://doi.org/10.1016/j.matpr.2018.08.139 SN - 2214-7853 VL - 5 IS - 13 SP - 26703 EP - 26708 PB - Elsevier CY - Amsterdam, Netherlands AN - OPUS4-47097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh A1 - Kadoke, Daniel A1 - Fischer, Michael A1 - Kohlhoff, Harald A1 - Weisbrich, S. A1 - Neitzel, F. ED - Pastramă, Ştefan Dan ED - Constantinescu, Dan Mihai T1 - A small-scale test bridge for measurement- and model-based structural analysis N2 - To examine the capability to detect and localise damage using the Measurement- and Model-based Structural Analysis (MeMoS), a small-scale truss bridge (1520 mm × 720 mm × 720 mm) made of aluminium profiles is built as a test specimen for this purpose. The truss frame of the test bridge is made of aluminium profiles with a sophisticated design of the cross-sectional area. In comparison, with solid profiles, only a fraction of the material is needed to produce the profiles, while their bending resistance decreases slightly. The profiles are built into a truss frame by connecting them by means of fastening sets made of steel. The bridge model is mounted on four steel bearings which each of them consist of a cylinder arranged between two plates. Fixed bearings are made by holding onto one end of the bridge. The bridge is subjected by an external load by placing a heavy object beneath it. At the same time, measurements can be conducted below the bridge. Therefore, the bridge specimen is elevated by attaching it on a pedestal with four columns. Damages can be induced by loosening the fastening pieces. T2 - 35th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Sinaia, Romania DA - 25.09.2018 KW - Adjustment calculation KW - Finite element method KW - Damage detection and localisation KW - Structural analysis KW - Photogrammetry PY - 2018 SN - 978-606-23-0874-2 SP - 23 EP - 24 PB - PRINTECH CY - Bukarest AN - OPUS4-46116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüllmann, Dino A1 - Kohlhoff, Harald A1 - Erdmann, Jessica A1 - Neumann, Patrick P. ED - Pastramă, D. Ş. ED - Constantinescu, D. M. T1 - Control of a spherical parallel manipulator with three degrees of freedom N2 - In robotic applications, it is often necessary to orient a sensor quickly. Spherical parallel manipulators (SPM) are well suited for this purpose since they offer superior dynamics and structural stiffness as compared to serial manipulators. To control them, however, the kinematic equations have to be known. In this paper, a SPM with three degrees of freedom and the kinematic equations describing its mechanical properties are presented. T2 - 35th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Sinaia, Romania DA - 25.09.2018 KW - Spherical parallel manipulator KW - Control KW - 3 DoF PY - 2018 SN - 978-606-23-0874-2 SP - 159 EP - 160 PB - PRINTECH CY - Bukarest AN - OPUS4-46141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -