TY - JOUR A1 - Neumann, Patrick P. A1 - Hirschberger, Paul A1 - Bartholmai, Matthias ED - Zemčík, R. ED - Krystek, J. T1 - Influence of rotor downwash on vertically displaced nanobots in flight N2 - One challenge associated with navigating a nano aerial robot swarm indoors in unstructured environments is, i.a., the limited air space. To avoid an over-regulation of the available indoor air space (e.g., prohibit copters to fly above each other), a safety region around each copter must be defined. In this paper, we investigate the impact of the downwash of a nano-drone on the stability of another nearby nano-drone. In the experiments, we found out that this downwash has a negative influence of a second nano-drone in a distance of around 1 m vertically and 0.2 m horizontally. Based on the obtained data, we developed a model describing the above-mentioned safety region to enable a safe operation of the swarm in these environments with fewer constraints. T2 - 36th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Pilsen, Czech Republic DA - 24.09.2019 KW - Mobile Robot Olfaction KW - Nano aerial robot KW - Swarm KW - Collision-free navigation KW - Safety region model PY - 2020 DO - https://doi.org/10.1016/j.matpr.2020.03.047 VL - 32 IS - 2 SP - 108 EP - 111 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-50673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Schriever, Robert A1 - Schartel, Bernhard T1 - Influence of external heat flux and coating thickness on the thermal insulation properties of two different intumescent coatings using cone calorimeter and numerical analysis N2 - Polymeric intumescent coatings are fire protective materials that increase their thermal resistance when exposed to high temperatures to prevent building structures from damage. The idea of the investigation was to develop a simple test method to determine the time dependent thermal conductivity of intumescent coatings. Therefore steel plates were coated with two different intumescent systems. During cone calorimeter tests the temperature at the back side of the coated plates was measured. These results were used to calculate the time dependent thermal resistance of the protective layer with the simulation program IOPT2D for different external heat fluxes and different layer thickness. KW - Intumescent coatings KW - Thermal resistance KW - Cone calorimetry KW - Numerical analysis PY - 2003 DO - https://doi.org/10.1002/fam.823 SN - 0308-0501 SN - 1099-1018 VL - 27 IS - 4 SP - 151 EP - 162 PB - Heyden CY - London AN - OPUS4-2633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Kammermeier, Michael A1 - Koeppe, Tabea A1 - Werner, Klaus-Dieter ED - Nicoletto, G. ED - Pastrama, S.D. ED - Emri, I. T1 - High dynamic measurement of strain and acceleration using a multichannel measuring system with single cable serial connection N2 - Strain and acceleration measurement during high dynamic drop tests, e.g., of containments for dangerous goods is performed using high speed multichannel measuring systems. So far established and operated systems need a cable connection of every strain gauge and acceleration sensor with the measuring device, often counting up to a number of more than 100 cables, corresponding to the number of applied sensors. The result is a massive cable harness consisting of all single cables, which is difficult to handle and causes a number of practical problems. An innovative approach is proposed by using a single cable measuring system, consisting of measuring modules with data bus connection and local data acquisition. Promising results were presented in a previous study. This paper follows up with additional results from full-scale testing of a further enhanced single cable system for the application in drop tests. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Multichannel measuring KW - Single cable serial connection KW - Dangerous goods container KW - Drop test KW - High impact testing PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.023 SN - 2214-7853 VL - 3 IS - 4 SP - 931 EP - 935 PB - Elsevier Ltd. AN - OPUS4-35689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Bennetts, V.H. A1 - Lilienthal, A.J. A1 - Bartholmai, Matthias A1 - Schiller, J.H. T1 - Gas source localization with a micro-drone using bio-inspired and particle filter-based algorithms N2 - Gas source localization (GSL) with mobile robots is a challenging task due to the unpredictable nature of gas dispersion, the limitations of the currents sensing technologies, and the mobility constraints of ground-based robots. This work proposes an integral solution for the GSL task, including source declaration. We present a novel pseudo-gradient-based plume tracking algorithm and a particle filter-based source declaration approach, and apply it on a gas-sensitive micro-drone. We compare the performance of the proposed system in simulations and real-world experiments against two commonly used tracking algorithms adapted for aerial exploration missions. KW - Autonomous micro UAV KW - Chemical and wind sensing KW - Gas source localization KW - Particle filter PY - 2013 DO - https://doi.org/10.1080/01691864.2013.779052 SN - 0169-1864 SP - 725 EP - 738 PB - VNU Sciences Pr. CY - Utrecht AN - OPUS4-28010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Hirschberger, Paul A1 - Bartholmai, Matthias ED - Holl, H. T1 - Flying ant robot for chemical trail detection and localization N2 - This paper presents first advances in the area of aerial chemical trail following. For that purpose, we equipped a palm-size aerial robot, based on the Crazyflie 2.0 quadrocopter, with a small lightweight metal oxide gas sensor for measuring evaporated ethanol from chemical trails. To detect and localize a 5 cm wide chemical trail, a detection criterion was developed that uses only relative changes in the transient phase of the sensor response. The reduction in signal strength dependence improves the robustness of its application. We tested our setup in first crossing-trail experiments showing that our flying ant robot can correlate an odor hit with the chemical trail within 0.14 m. Principally, this could enable aerial chemical trail following in the future. T2 - 37th Danubia - Adria Symposium on Advances in Experimental Mechanics CY - Linz, Austria DA - 21.09.2021 KW - Aerial robot KW - Trail following KW - Trail detection KW - Localization PY - 2022 DO - https://doi.org/10.1016/j.matpr.2022.02.594 SN - 2214-7853 VL - 62 SP - 2462 EP - 2465 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-54507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mansurova, Maria A1 - Gotor, Raúl A1 - Johann, Sergej A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias A1 - Rurack, Knut A1 - Bell, Jérémy T1 - Fluorescent Hydrophobic Test Strips with Sterically Integrated Molecular Rotors for the Detection of Hydrocarbons in Water and Soil with an Embedded Optical Read-Out N2 - Contamination of natural bodies of water or soil with oils and lubricants (or generally, hydrocarbon derivatives such as petrol, fuels, and others) is a commonly found phenomenon around the world due to the extensive production, transfer, and use of fossil fuels. In this work, we develop a simple system for the on-field detection of total petroleum hydrocarbons (TPHs) in water and soil. The test is based on the measurement of the fluorescence signal emitted by the molecular rotor 2-[ethyl[4-[2-(4-nitrophenyl)ethenyl]phenyl]amino]ethanol (4-DNS-OH). This dye is embedded in a hydrophobic polymeric matrix (polyvinylidene fluoride), avoiding interactions with water and providing a robust support for use in a test strip fashion. Together with the strips, an embedded optical system was designed for fluorescence signal read-out, featuring a Bluetooth low-energy connection to a commercial tablet device for data processing and analysis. This system works for the detection and quantification of TPHs in water and soil through a simple extraction protocol using a cycloalkane solvent with a limit of detection of 6 ppm. Assays in surface and sea waters were conclusive, proving the feasibility of the method for in-the-field operation. KW - Test strip KW - Sensor KW - Smartphone KW - Fluorescence KW - Test Streifen KW - Sensoren KW - Fluoreszenz KW - Petrol KW - Öl PY - 2023 DO - https://doi.org/10.1021/acs.energyfuels.3c01175 SN - 0887-0624 SP - 1 EP - 6 PB - American Chemical Society CY - Washington, United States AN - OPUS4-57892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartelmeß, Jürgen A1 - Zimmek, David A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph A1 - Schäferling, M. T1 - Fibre optic ratiometric fluorescence pH sensor for monitoring corrosion in concrete N2 - In this communication a novel concept for pH sensing is introduced which is specifically adapted to monitor carbonation induced corrosion in concrete structures. The method is based on a ratiometric measurement principle, exploiting the pH sensitive colour switching of thymol blue in the basic pH regime and the emissive properties of two different (Zn)CdSe/ZnS core shell quantum dots. The transition point of thymol blue in a Hydrogel D4 matrix was determined to be at around pH 11.6, which fits ideally to the intended application. Next to the fundamental spectroscopic characterization of the ratiometric response, a new design for a sensor head, suitable for the incorporation into concrete matrices is presented. Toward this, a manufacturing process was developed which includes the preparation of a double layer of polymers containing either thymol blue or a quantum dot mixture inside a porous ceramic tube. Results of a proof-of-priciple performance test of the sensor head in solutions of different pH and in cement specimens are presented, with encouraging results paving the way for future field tests in concrete. KW - Fiber optic sensing KW - PH monitoring in concrete KW - Embedded sensors KW - Ratiometric fluorescence PY - 2020 DO - https://doi.org/10.1039/c9an02348h VL - 145 IS - 6 SP - 2111 EP - 2117 PB - Royal Society of Chemistry AN - OPUS4-50381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter A1 - Kammermeier, Michael A1 - Köppe, Enrico T1 - Erprobung eines Messsystems mit Datenbus und dezentraler Datenspeicherung für den Einsatz bei Fallprüfungen N2 - Zur Untersuchung der Sicherheit von Behältern für den Transport und die Lagerung von Gefahrstoffen und -gütern werden Fallprüfungen durchgeführt. Die Aufpralldynamik und die strukturmechanischen Einwirkungen auf den Behälter werden mittels Beschleunigungsaufnehmern und Dehnungsmessstreifen erfasst. Dabei kommen derzeit Vielkanalmesssysteme zum Einsatz, die eine Verkabelung jeder einzelnen Messstelle und somit das Mitfallen eines Kabelbaums erfordern, wodurch Probleme bei der Versuchsvorbereitung und Durchführung entstehen. Die Verwendung eines Messsystems mit Datenbus und dezentraler Datenspeicherung bietet diesbezüglich einen vielversprechenden Lösungsansatz. KW - Vielkanalmesssystem KW - Datenbus KW - Gefahrstoffe KW - Behälter KW - Fallprüfung KW - Hopkinsonstab KW - Multichannel measuring system KW - Data bus KW - Dangerous goods KW - Container KW - Drop test KW - Hopkinson bar PY - 2009 DO - https://doi.org/10.1524/teme.2009.0945 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 76 IS - 10 SP - 447 EP - 454 PB - Oldenbourg CY - München AN - OPUS4-20284 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Hüllmann, Dino A1 - Bartholmai, Matthias ED - Pastramă, Ş. D. ED - Constantinescu, D. M. T1 - Concept of a gas-sensitive nano aerial robot swarm for indoor air quality monitoring N2 - In this paper, we introduce a nano aerial robot swarm for indoor air quality monitoring applications such as occupational health and safety of (industrial) workplaces. The concept combines a robotic swarm composing of nano Unmanned Aerial Vehicles (nano UAVs), based on the Crazyflie 2.0 quadrocopter, and small lightweight metal oxide gas sensors for measuring the Total Volatile Organic Compound (TVOC) in ppb and estimating the eCO2 (equivalent calculated carbon-dioxide) concentration in ppm. TVOC is a measure for the indoor air quality. An indoor localization and positioning system will be used to estimate the absolute 3D position of the swarm like GPS. Based on this novel indoor air quality monitoring concept, the development and validation of new algorithms in the field of Mobile Robot Olfaction (MRO) are planned, namely gas source localization and gas distribution mapping. A test scenario will be built up to validate and optimize the gas-sensitive nano aerial robot swarm for the intended applications. T2 - 35th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Sinaia, Romania DA - 25.09.2018 KW - Nano aerial robot KW - UAV KW - Swarm KW - Indoor air quality KW - Monitoring KW - Concept PY - 2019 DO - https://doi.org/10.1016/j.matpr.2019.03.151 SN - 2214-7853 VL - 12 IS - 2 SP - 470 EP - 473 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-48055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Petrov, Sergej A1 - Neumann, Patrick P. A1 - Werner, Klaus-Dieter A1 - Wosniok, Aleksander A1 - Lazik, D. A1 - Bartholmai, Matthias ED - Nicoletto, G. ED - Pastrama, S.D. ED - Emri, I. T1 - Concept for investigating mechanical and thermal impacts on distributed subsurface gas monitoring N2 - A multifunctional sensor in line shape was developed and introduced in previous work for measuring of gas concentrations, temperature change, and strain. A current field study focuses on a spatially distributed monitoring of subsurface CO 2 gas storage sites in near real time. Mechanical impacts, e.g., caused by construction work, denudation, and seismic activity, can affect the integrity of underground gas storage sites. Thermal or moisture impacts, e.g., caused by weather conditions, can influence the gas Distribution behavior. In this paper, we briefly describe the setup of a CO 2 injection soil test field. This setup contains actuating elements for the investigation of mechanical and thermal impacts on distributed subsurface gas monitoring. A concept is given for evaluating these impacts and first experimental results are presented. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Linear sensor KW - Distributed sensor KW - Monitoring of CO 2 KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fibre optical sensing PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.060 SN - 2214-7853 VL - 3 IS - 4 SP - 1124 EP - 1128 PB - Elsevier Ltd. AN - OPUS4-35688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -