Filtern
Erscheinungsjahr
Dokumenttyp
- Beitrag zu einem Tagungsband (56) (entfernen)
Sprache
- Englisch (48)
- Deutsch (7)
- Mehrsprachig (1)
Referierte Publikation
- nein (56) (entfernen)
Schlagworte
- Nano aerial robot (5)
- Drop test (4)
- Gas sensors (4)
- Monitoring (4)
- RFID sensors (4)
- Structural health monitoring (4)
- Swarm (4)
- Air quality monitoring (3)
- Gas source localization (3)
- Hazardous scenarios (3)
- LoRaWAN (3)
- Mobile Robot Olfaction (3)
- Multisensor system (3)
- Smart structures (3)
- VOC (3)
- Air quality (2)
- Chemical sensing (2)
- Concrete (2)
- Condition monitoring (2)
- Dangerous goods (2)
- Data-fusion (2)
- Electronic nose (2)
- Embedded sensor (2)
- Environment (2)
- Funksensorik (2)
- Gas sensing (2)
- Gas storage areas (2)
- Indoor air quality (2)
- Long term monitoring (2)
- Membrane-based gas sensing (2)
- Mikrodrohne (2)
- Mobile sensing system (2)
- Multi-sensor system (2)
- Passive RFID (2)
- Quadrocopter (2)
- RFID (2)
- SHM (2)
- Safety management (2)
- Sensornetzwerk (2)
- Sensors (2)
- Sensors in concrete (2)
- Smart sensors (2)
- Spectroscopy (2)
- Strukturüberwachung (2)
- Subsurface monitoring (2)
- Accelerometer (1)
- Aerial robot olfaction (1)
- Ammonia gas sensor (1)
- Analysis (1)
- Anemotaxis (1)
- Artificial potential field (1)
- Autonomous UAV (1)
- Autonomous micro UAV (1)
- Bauteilmonitoring (1)
- Berlin Main Station (1)
- Bio-inspired (1)
- Biologically inspired robots (1)
- Bridge components (1)
- Calibration of electrical quantities (1)
- Calibration of force (1)
- Calibration of temperature (1)
- Chemotaxis (1)
- Cone Calorimeter (1)
- Data fusion (1)
- Dehnungsmessstreifen (1)
- Differential displacements (1)
- Digital Certificates (1)
- Digitalisation (1)
- Distributed linear sensor (1)
- Distributed multifunctional sensor (1)
- Drop (1)
- DuraBASt (1)
- Early-damage-detection (1)
- Eindringmodul (1)
- Electronic transport documents (1)
- Embedded (1)
- Embedded systems (1)
- Emmbedded sensor (1)
- Energy harvesting (1)
- Faser-Bragg Gitter (1)
- Fiber bragg grating (1)
- Fiber optical sensing (1)
- Fire retardancy (1)
- Fluorescence (1)
- Fluoreszenzlöschung (1)
- GC-MS (1)
- Gas detection (1)
- Gas detector (1)
- Gas distribution mapping and gas source localization (1)
- Gas distribution modeling (1)
- Gas distribution modelling (1)
- Gas storage sites (1)
- Gasfreisetzung (1)
- Gefährdungsbeurteilung (1)
- High impact shock application (1)
- Hochdynamische Untersuchungen (1)
- Hopkinson bar (1)
- Hopkinson pressure bar (1)
- Hopkinson-Stab (1)
- Humidity sensors (1)
- Hydraulic levelling system (1)
- Hydrogen technology (1)
- Härtevergleichsplatten (1)
- Impact (1)
- Indoor Localization (1)
- Inertial measurement unit (1)
- Inertial navigation system (1)
- Instrumentierte Eindringprüfung (1)
- Intumescence (1)
- Klebstoffe (1)
- Kraftabhängige Funktion (1)
- Lamb-waves (1)
- Laser-based displacement measuring system (1)
- Localization (1)
- Localization of gas sources (1)
- Magnetic field (1)
- Magneto-optischer Sensor (1)
- Magnetostrictive metal coating (1)
- Magnetostriktive Beschichtung (1)
- Maschinennachgiebigkeit (1)
- Measurement (1)
- Measurement uncertainty (1)
- Methane measuring (1)
- Micro UAV (1)
- Miniaturized sensor device (1)
- Mobile Robot (1)
- Mobile robot olfaction (1)
- Moisture measurements (1)
- Multi sensor device (1)
- Multi-Hop WSN (1)
- Multi-sensor device (1)
- Multichannel measuring (1)
- Multihop (1)
- NDT Inspection (1)
- Nano UAV Swarm (1)
- Nanocomposites (1)
- New sensor principles (1)
- Nitroaromaten (1)
- Non-destructive evaluation (1)
- Odor localization (1)
- Olfaction (1)
- Passive sensor interface (1)
- Pattern recognition methods (1)
- Person tracking (1)
- Piezoresistive accelerometer (1)
- Plume tracking (1)
- Prototyp (1)
- Pump control (1)
- Quadrokopter (1)
- Quality Infrastructure (1)
- Quantification of gas concentrations (1)
- RAM packages (1)
- RFID Sensor systems (1)
- RFID based sensors (1)
- Radioactive (1)
- Reactive plume tracking (1)
- Red Phosphorus (1)
- Robotik (1)
- Schadensfrüherkennung (1)
- Selbstkalibrierung (1)
- Selective permeability (1)
- Self-diagnostic fiber optical sensor (1)
- Sensor (1)
- Sensor calibration and validation (1)
- Sensor planning (1)
- Setup and Validation (1)
- Single cable system (1)
- Spatially distributed monitoring (1)
- Sphärische Indenter (1)
- Standard gas generator (1)
- Strain measurements (1)
- Structural Health Monitoring (1)
- Structure health monitoring (1)
- Suche und Lokalisierung von gasförmigen Gefahrstoffquellen (1)
- System adhesive/ strain gauge (1)
- Temperaturabhängige Prüfung (1)
- Temperature and Frequency Compensation (1)
- Temperature behavior (1)
- Temperature calibration (1)
- Temperature characteristics (1)
- Temperature dependent and high dynamic load tests (1)
- Temperaturkompensation (1)
- Test (1)
- Tomographic reconstruction of gas plumes (1)
- Trail detection (1)
- Trail following (1)
- Transmission characteristics (1)
- Tunable Diode Laser Absorption Spectroscopy (TDLAS); UAV-REGAS (1)
- UHF antenna (1)
- Ultrasound (1)
- Urban air monitoring (1)
- Vereinfachtes Verfahren (1)
- WLAN (1)
- WiFi (1)
- Wireless sensor network (WSN) (1)
- Wireless sensors (1)
- poultry odorous air monitoring (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (22)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (22)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (3)
- 1 Analytische Chemie; Referenzmaterialien (2)
- 1.9 Chemische und optische Sensorik (2)
- 3 Gefahrgutumschließungen; Energiespeicher (1)
- 3.3 Sicherheit von Transportbehältern (1)
- 6 Materialchemie (1)
- 6.7 Materialsynthese und Design (1)
- 8.6 Faseroptische Sensorik (1)
Temperature characteristics of a piezoresistive accelerometer for high impact shock application
(2018)
This study presents the characterization of a piezoresistive accelerometer damped with silicon oil for the application in drop tests carried out at BAM. Experiments were performed with the Hopkinson Bar method in close correlation to the real-world application conditions. The results point out certain limitations regarding the temperature influence and the frequency response. Additional experiments were performed with a gas damped type of piezoresistive accelerometer, which has superior specifications, particularly for low temperatures. The results allow for a comparison.
In preliminary work, gas sensors in linear form based on the measuring principle of gas selective permeability through a membrane were developed and introduced for the detection and quantification of gas concentrations. In this study, first experimental results are presented for adapting the technology for measuring methane (CH4). A material with suitable selective permeability was identified and utilized in a sensor setup containing the gas selective membrane and a reference membrane, both integrated in a measuring cell, to which a gas stream with defined CH4 concentrations was applied. The results prove the sensor's capability for measuring methane and indicate further application potential of the method, e.g., as a robust field monitoring technology, since CH4 is the major component of natural gas, town gas, and fracking gas.
Long-term completely embedded sensor systems offer innovative possibilities for structural health monitoring of concrete structures. Measuring of relevant parameters, e.g., temperature, humidity, or indication of corrosion can be performed with low energy sensors. This allows to implement passive RFID sensor systems without cable connection and battery, which are power supplied exclusively by the electromagnetic field from the external reader device. To evaluate characteristics and conditions of this concept, a systematical investigation of the transmission characteristics with variation of relevant parameters, as communication frequency, installation depth, type of concrete, moisture content, etc. is currently carried out in an interdisciplinary research project at BAM. First results are presented in this paper.
Embedded wireless sensor systems for long-term SHM and corrosion detection in concrete components
(2017)
State-of-the-art communication standards like RFID and Bluetooth Low Energy enable the development of sensor systems which can be completely embedded into concrete components for long-term SHM and early damage detection. Objective of the project KonSens which is carried out at BAM is the development, implementation, and validation of sensors for measuring of Parameters relevant for corrosion, like moisture, pH value, and electrical conductivity, inside steel reinforced concrete components. The primarily addressed application is detection and evaluation of corrosion processes in concrete bridges.
In contrast to cable connected sensors, embedded wireless sensors avoid any pathways for intrusion of moisture and chemicals, e.g., chlorides which could trigger corrosion activity. To allow for long-term, ideally life-time operation, the once embedded sensor systems must work highly energy efficient. One option are passive RFID sensor systems, which work without battery. The energy is transmitted to the system through the electromagnetic field, even to operate sensors. A crucial parameter is the transmission depth in concrete. First experiments with RFID sensors working at frequencies of 13.56 MHz (HF) and 868 MHz (UHF) embedded in concrete specimen resulted positive for transmission depths of up to 13 cm, which is quite promising, considering that corrosion would appear first at the top level of rebars.
A second generation of passive RFID sensor systems has been implemented with improved antenna design. Current experiments using these systems focus on the Transmission characteristics in terms of transmission depths and the impact of concrete moisture. Low-energy humidity sensors are used and analysed regarding their capability for measuring the material moisture. Additionally, a relation between transmitted power to the embedded sensor and the moisture content of the concrete specimen caused by energy absorption can be presumed and is under systematic investigation.
Wireless sensor network for long-term structural health monitoring of buildings and infrastructures
(2009)
Damage commonly occurs in buildings when a component fails suddenly with a
partial or total collapse as a consequence. This type of event leads to serious damage to property
and if it is a bridge or a large hall, then people in particular are at risk. The often great age of
bridges and the increasing volume of traffic (particularly heavy traffic) which they are expected
to carry are in clear contradiction to each other. Thus the probability increases that the loadbearing
capacity of a bridge decreases rapidly and often unnoticed with sometimes dire
consequences.
In order to prevent such accidents, the Federal Institute for Materials Research and Testing is
currently developing a special radio-based, self-configuring measuring system in cooperation
with the Berlin-based ScatterWeb Company. This measuring system consists of a number of
identically designed sensor nodes which are self-sustaining, need no wiring, can act as both
transmitters and receivers and are equipped with a special sensor technology making long-term
monitoring of buildings or engineering facilities possible. The sensor unit uses strain gauges for
stress analysis and contains interfaces for additional sensors. The system in particular applies to
buildings and structures for transport and traffic and large-scale industrial facilities, where a
subsequent wiring installation is difficult or impossible.
The combination of radio-frequency identification (RFID) tags with different types of sensors offers excellent potential for applications with regard to identification, diagnosis, and monitoring. This should be demonstrated by means of two examples of actual developments carried out by the Federal Institute for Materials Research and Testing (BAM). The Identification and diagnosis of concrete components is a major task in the maintenance of critical infrastructure, for instance concrete bridges with heavy traffic volume. A feasibility study investigates the application of RFID sensor systems for this task. The second example reviews the transportation of dangerous goods. Using modern technologies enables promising possibilities to reduce accidents and to avoid non-conformity with transportation regulations. Project results demonstrate an innovative technical solution for monitoring of dangerous goods transports with RFID sensor systems.
Piezoresistive accelerometers use a strain-sensing element, generally made of semiconductor material, e.g., silicon to convert the mechanical motion into an electrical signal. This element is usually designed in form of a cantilever beam loaded with a mass. Acceleration causes bending of the beam, which produces a change of electrical resistance proportional to the applied acceleration.
Main advantages of piezoresistive accelerometers in comparison to other types, e.g., piezoelectric and capacitive, is their robust and highly dynamic behavior, which qualifies them for application in high impact shock applications. Mechanical damping is typically implemented with silicon oil in a way that the output signal is undistorted over a wide frequency range. These characteristics principally qualify them for the application in drop tests carried out at BAM, for which they are calibrated over the frequency range from 1 to 4 kHz. However, using silicon oil for damping, has the drawback of temperature dependent change of its viscosity, leading to temperature dependent deviation of the accelerometer’s sensitivity.
This study presents experimental results of the temperature behavior of a piezoresistive accelerometer with a dynamic range up to ±5000 g.
This type of accelerometer is applied for drop tests which are partially performed at temperatures of -40 or +100 °C.
Multichannel measuring systems are used to measure strains and accelerations during drop tests of containments for dangerous goods. Conventional systems require cabling of each sensor and co-falling of the cable harness, causing problems in the test preparation and execution. Promising results of a single cable measuring system, consisting of measuring modules with data bus connection and local data acquisition were obtained in laboratory investigations and full-scale drop tests.
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.
In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen.
Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann.
Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten.
Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht.
The present paper describes the development of a sensor material that changes its fluorescence in the presence of gaseous ammonia in a relevant concentration range. The implementation into a semi-automatic gas measurement device enables low-cost, precise, simple and fast monitoring of low con-centrations of harmful gases, like ammonia, and hence can help to improve the climate monitoring in livestock housing, barns or stables.
In the present paper the development of a semi-automated device for long-term monitoring of gaseous ammonia is described. A sensor material was produced that changes its optical properties in the pres-ence of low concentrations of ammonia in air. The implementation into an electronic device enables precise, simple, economic and fast monitoring of low concentrations of harmful gases, like ammonia, and hence can help to improve the climate monitoring in livestock housing, barns or stables.
Because ammonia and its reaction products can cause considerable damage to human health and ecosystems, there is a need for reliably operating and reversibly interacting sensor materials to monitor traces of gaseous ammonia in ambient air, which at best can be used on-site for in-the-field measurements. Herein, the development of a sensor material for gaseous ammonia in the lower ppm to ppb range using optical fluorescence as transduction mechanism is presented. A fluorescent dye, which shows reversible fluorescence enhancement in the presence of ammonia is incorporated into a polymer matrix, the latter to ensure the accumulation of ammonia. The sensor material is integrated into a prototype of a miniaturized sensor device, facilitating long-term operation. To calibrate the optical sensor system a gas standard generator, producing standard gas mixtures, is used, leading to a sensitivity down to lower ppm concentrations of ammonia.
The project SIGRID investigates and assesses possibilities to enhance the safety and security of
dangerous goods transports through the use of the latest RFID-technology. This technology can be used to
greatly enhance the transparency of the supply chain and aid logistics companies in complying with regulations.
In the context of SIGRID, customized RFID-Sensor-Tags have been developed that monitor dangerous
goods during transport and help to prevent hazards by allowing timely countermeasures. In the case of a dangerous
goods accident, the available information about the type, amount and condition of the dangerous goods
can be used to accurately inform the relief forces. Unavailable or inaccurate information represents a significant
problem for the relief forces. This often leads to a delay in the rescue operation, because relief forces
must be aware of the substances involved to protect themselves effectively against them. SIGRID aims to
close this information gap. To verify the practicability of the underlying concepts, a demonstrator will be
build and tests of realistic scenarios will be conducted.
Design and Implementation of Smart Multisensor Monitoring System for Safe Workplaces with LoRaWAN
(2020)
This project addresses the application of safe workplaces in offices and chemical laboratories where indoor air quality plays an important role. The LoRaWAN (Long Range Wide Area Network) is used as a communication interface to make important sensor data globally accessible. The goal of the development is to create a sensor node and an online and offline solution that collects the data from the sensor nodes and stores it on a local server or in a cloud. In cooperation with the companies WISTA GmbH and IONOS, a test sensor network is going to be established in the Berlin-Adlershof area.
This paper deals with the development and investi-gation of a volatile organic compound (VOC) system for differ-ent scenarios. The integrated multi-sensor unit can detect dif-ferent gases through the integrated 3-fold VOC sensor, where-by a continuous measurement takes place. The system-integrated flow control, with pump and flow sensor, allows the gas molecules to be transported directly to the VOC sensor. The entire measurement is permanently stored on an integrat-ed Secure Digital (SD) card. If the previously determined limit range is exceeded, an alarm is generated. Due to the combina-tion of different components, numerous applications are possi-ble. The system is the first step or a tool towards further devel-opments in the field of gas sensors and is primarily used for the validation of chemically based gas sensors, and it is still largely extended by application-specific influences.
This paper is a further research on the topic of the complete embedding of radio frequency identification (RFID) sensors in concrete. The focus is on the antenna of the transponder. Earlier investigations of different RFID technologies, embedded in concrete, showed a difference in energy transmission. The transmission through concrete at ultra high frequency (UHF), in spite of the large signal range, does not match the targeted application specific task. Therefore, the antenna characteristics have been examined more closely. The antenna is an important component for the application of RFID. Through the antenna, energy and data transfer takes place, so it is important to design an optimal antenna to accomplish a maximum embedding depths in concrete. To identify the optimal antenna geometry, different UHF antenna types were selected and investigated. An experimental comparison was performed to gain more information about the damping behavior and antenna characteristics in concrete.
Structural Health Monitoring (SHM) has become very important in today's rapidly developing time. High buildings, large bridges and complex technical structures need to be monitored continuously and this over long periods.
Visual monitoring cannot evaluate the internal condition of building structures. Thus, material embedded sensors are needed. Cable connection of these sensors pose the disadvantage of weak spots and water intrusion. For concrete embedded sensors the use of batteries is not convenient, because of limited lifetime, difficult charging, and generation of electrical waste.. Hence, monitoring should be implemented preferentially with firmly embedded passive RFID sensor modules. However, since the concrete structure forms an electromagnetically reflective and absorbing barrier, only limited energy can be transmitted to the module. This project requires a highly energy-saving system, which can record different sensor parameters at critical points.