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IEEE sensorS

作者： Felix Laub Christoph Haugwitz Gianni Allevato Julian Seiler Rolf Findeisen Mario Kupnik Measurement and Sensor Technology Group Technische Universität Darmstadt Germany

Air-coupled ultrasonic non-destructive testing (NDT) enables the inspection of composite materials for defects. In this paper, we investigate non-contact defect detection based on Lamb waves by using two dedicated air-coupled ultrasonic phased arrays, i.e. one for transmission and one for reception. The major challenge is the signal detection of the reflected leaky Lamb wave originating from the defect, despite a strong interfering signal, i.e. the direct air-path wave, causing a so-called blind zone. Therefore, we exploit the angular difference of the reflected leaky Lamb wave and the direct air-path wave by applying high-resolution direction of arrival $(\text{DoA})$ estimation algorithms, i.e. MVDR beamformer (Capon) and MUSIC algorithms, as well as image deconvolution methods, i.e. CLEAN and Richardson-Lucy algorithms. First, we assess the signal detection capability by using Monte Carlo simulations considering realistic non-ideal array elements. Second, we validate the simulations by conducting testbed measurements, which show that conventional beamforming (CBF), MVDR and MUSIC are capable of fully air-coupled defect detection, even when the direct air-path wave is impinging. We conclude that the blind zone can be eliminated and show that the MUSIC algorithm excels in highlighting the reflected leaky Lamb wave.

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Early Detection of Faillure in Conveyor Chain Systems by Wireless sensor Node

Early Detection of Faillure in Conveyor Chain Systems by Wir...

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IEEE sensorS

作者： Ghada Bouattour Lidu Wang Sajidah Al-Hammouri Jiachen Yang Christian Viehweger Olfa Kanoun Professorship for Measurement and Sensor Technology Technische Universitat Chemnitz Chemnitz Germany

In the ever-growing industrial landscape, the early detection of failures in machines with high accuracy becomes more and more crucial and essential to safe and dependable operations. Based on this concept, a machine learning algorithm is investigated for early detection of failure for conveyor chain systems. The proposed approach is based on the integration of wireless sensor nodes in the conveyor chain to measure the vibrations. The collected data has been acquired in different working conditions including slight imbalances as well as early failure scenarios that do affect the plastic chain. The data was collected using a conveyor chain with a length of 2 meters and with programmable speed and movement scenarios. Furthermore, different loads and forces have been considered during the data collection to mimic real applications in the lab. The selection of features to avoid correlation between them is considered. After comparison between different machine learning algorithms, the C-SVM algorithm is selected with an accuracy of 96.5%, which guarantees high precision and selectivity to the failures.

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A Gas Imaging sensor System of Automotive Exhaust Plumes for Remote Emission Sensing Application Basing on Schlieren Imaging An Approach to Visualize and Size Vehicle Exhaust Plumes

A Gas Imaging Sensor System of Automotive Exhaust Plumes for...

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IEEE sensorS

作者： Hafiz Hashim Imtiaz Paul Schaffer Martin Kupper Alexander Bergmann Institute of Electrical Measurement and Sensor Systems University of Technology Graz Austria

In this work we present a system for remote emission sensing (RES), focusing on a system for optical gas imaging, to enable direct concentration measurements by a Tunable Diode Laser Absorption Spectroscopy (TDLAS) technique. The technique is basing on background oriented schlieren imaging to give a robust information of the exhaust plume size, thus the absorption length of the laser. We present the description of the system, our approach of AI-based image processing and verification results. The gas imaging system was tested on-road and characterized in lab with controlled gas mixtures. First results from lab characterization and on-road measurements prove the feasibility of the approach, i.e. exhaust plumes of passing cars are reliably detected and the sizes of plumes are then calculated appropriately.

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CAPACITIVE CALIBRATION CAPABILITIES IN AN EMFC BALANCE 24

CAPACITIVE CALIBRATION CAPABILITIES IN AN EMFC BALANCE

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24th IMEKO TC3 Conference on measurement of Force, Mass and Torque 2022, Together with the 14th TC5 Conference on the measurement of Hardness, the 6th TC16 Conference on Pressure and Vacuum measurement, and the 5th TC22 Conference on Vibration measurement

作者： Cherkasova, V. Fröhlich, T. Institute for Process Measurement and Sensor Technology Technische Universität Ilmenau PF 10 05 65 Ilmenau98684 Germany

ISBN: (纸本)9781713870203

The article describes the possibilities of calibrating the force constant in an electromagnetic force compensation (EMFC) load cell using the electrostatic force compensation principle. The static and dynamic principles of calibration of the Kibble balance for the electrostatic force constant, as well as calibration by means of compensation of the electrostatic force by the electromagnetic force, are considered. The combination of the two compensation principles in the load cell allows the measurement of forces in the range of 20 pN to 2.2 mN and ensures traceability to national standards. The relative uncertainty in the measurement of forces of about 100 nN is estimated to be about 0.001. © 2023 *** All Rights Reserved.

关键词： Calibration

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Plasma-Treated Polyimide Film Modified by Liquid Epitaxially Grown HKUST-1 MOFs for Sensing Application

Plasma-Treated Polyimide Film Modified by Liquid Epitaxially...

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Impedance Spectroscopy (IWIS), International Workshop on

作者： Oumayma Otay Amir Mrayeh Ge Shi Tianqi Lu Anurag Adiraju Salma Bizid Olfa Kanoun Ayoub Haj Said Center for Research on Microelectronics and Nanotechnology Sousse Tunisia Professorship of Measurement and Sensor Technology Chemnitz University of Technology Chemnitz Germany

ISBN: (数字)9798331507626

ISBN: (纸本)9798331507633

Metal-organic framework (MOFs) materials have the potential to be used in electrochemical sensors thanks to their porous nature, high surface area, and periodic lattice structures. However, the insulating nature of pristine MOFs is one of the drawbacks that limit their applicability in electrochemical sensors. Several works have proposed their integration with carbon nanomaterials to enhance the conductivity. On the other hand, Laser-induced graphene (LIG) is a one-step method to fabricate conductive graphene-based electrodes on flexible substrates such as Kapton. In this regard, this research proposes a novel methodology to fabricate surface-mounted MOFs (SURMOF) and LIG-based composite electrodes on Kapton. The Kapton sheet is modified with HKUST-1 MOF by alternative immersions in precursor solutions to achieve layer-by-layer (LbL) deposition and growth. Hence, Kapton is pre-treated with plasma to enhance the hydrophilicity by introducing oxygen functional groups on the surface which was confirmed with contact angle measurements. Different precursor materials were investigated for the LBL growth of HKUST-1. The obtained SURMOF on Kapton was characterized by spectroscopic methods. Finally, UV laser interaction with HKUST-1-modified Kapton led to the formation of LIG. The electrochemical performance of LIG on modified Kapton was compared with bare LIG. The proposed methodology is promising to realize flexible, easy-to-fabricate LIG-MOF'S electrodes for electrochemical sensors.

关键词： Electrodes Surface impedance Spectroscopy Sensitivity Polyimides sensor phenomena and characterization Stability analysis sensors Surface treatment Substrates

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Shielding of Eddy Current Displacement sensors with a Single Backside Shield

Shielding of Eddy Current Displacement Sensors with a Single...

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IEEE sensorS

作者： G. Gruber M. Neumayer B. Schweighofer H. Wegleiter Christian Doppler Laboratory for Measurement Systems for Harsh Operating Conditions Institute of Electrical Measurement and Sensor Systems Graz University of Technology Graz Austria

ISBN: (数字)9798350363517

ISBN: (纸本)9798350363524

Eddy current displacement sensors (ECDS) are essential for accurate position measurement in heavy industries. For instance, in steel plants, position sensor systems often need to measure large displacements and withstand high temperatures, dirt, and dust exposure. Various protective measures, such as metal shields or chain curtains, create a restricted environment for such sensors and cause interference. Shielding techniques must be used to reduce this interference. However, due to spatial restrictions, established shielding techniques cannot always be applied. This study presents a design approach for a single-coil ECDS that reduces the effects of metal objects on the measurement signal by using a single backside shield. The accuracy of the proposed measurement system is improved by integrating shielding measures and selecting a suitable measurement frequency. This improvement is demonstrated through the lab measurements. The measures provide a basis for reliable position measurement with ECDS in harsh environments.

关键词： Temperature measurement Temperature sensors Coils Current measurement Metals Interference Position measurement sensors Frequency measurement Eddy currents

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Enhancing electrical and mechanical by Sn doping in BCZT for high performance nanogenerators 19

Enhancing electrical and mechanical by Sn doping in BCZT for...

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19th IEEE International Multi-Conference on Systems, Signals and Devices, SSD 2022

作者： Sarra, Misaaoui Ayda, Bouhamed Hamadi, Khemakhem Olfa, Kanoun Faculty of Sciences of Sfax Tunis Sfax Tunisia Teschnische Universität Chemnitz Chair for Measurement and Sensor Technology Chemnitz Germany

ISBN: (数字)9781665471084

ISBN: (纸本)9781665471084

Flexible and environment friendly piezoelectric nanogenerators are attracting substantial attention due to environmental constraints and ecological considerations of energy harvesting. In this paper, self-poled and bio-flexible piezoelectric nanogenerators (BF -PEN G) were developed based on lead-free BCZT and BCZT-0.02Sn nanoparticles that were synthesized using sol-qel method and embedded with PDMS polymer. To investigate the impact of doping, electrical and mechanical characterizations were conducted as well piezoelectric measurements. The results illustrate that PENG containing BCZT doped with 0.02 Sn shows higher performance comparing to PENG with BCZT. It can generate open circuit voltage of 4V under vibration shaker and 30 V under gentle finger tapping. This good piezoelectric performance is related to the enhanced mechanical behavior in addition to the enhanced conductivity with the integration of Sn within BCZT nanoparticle. © 2022 IEEE.

关键词： Nanoparticles

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A Wiener Filter Based Band-Pass FIR Differentiator with Zero Delay

A Wiener Filter Based Band-Pass FIR Differentiator with Zero...

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IEEE Instrumentation and measurement technology Conference

作者： M. Neumayer H. Wegleiter T. Bretterklieber Christian Doppler Laboratory for Measurement Systems for Harsh Operating Conditions Institute of Electrical Measurement and Sensor Systems Graz University of Technology Graz Austria

ISBN: (数字)9798350380903

ISBN: (纸本)9798350380910

The calculation of signal derivatives is a sensitive operation in digital signal processing. This is due to the high pass nature of the derivative operation and the subsequent noise amplification. Bandlimited differentiator designs based on FIR approximations are therefore commonly used. Another prominent technique is Savitzky-Golay-filtering to design FIR differentiators. However, all of these techniques introduce a temporal shift by the (constant) group delay of the odd FIR filters. In this work we present a FIR differentiator design for band-pass signals based on a Wiener filter approach. Therefore, the differentiation task is treated as a signal estimation problem, which leads to a delay free FIR differentiator. The design specifications for the filter, e.g. the bandwidth, are formulated in the frequency range. The properties and performance of the approach are presented by means of comparative simulation studies.

关键词： Band-pass filters Wiener filters Finite impulse response filters Simulation Frequency-domain analysis Noise Delays

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Simulated bubble oscillations in gearboxes for electrified vehicles 14

Simulated bubble oscillations in gearboxes for electrified v...

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14th International Conference on Recent Advances in Structural Dynamics, RASD 2024

作者： Hafner, Lukas Holzbrecher, Jonas Wiedenmann, Matthias Hieronymus, Timm Schwarzer, Steffen Dohnal, Fadi Evamo - Pump Technology Solutions PS GmbH Berlin Germany Research Center for Microtechnology Vorarlberg University of Applied Sciences Dornbirn Austria Institute of Measurement and Sensor Technology UMIT TIROL - Private University for Health Sciences and Health Technology Hall in Tirol Austria Institute for Drive Technology Aalen University of Applied Sciences Aalen Germany

The shift in drive concepts from internal combustion engines to electrified vehicles is changing the demands on drive machines and their associated subsystems. A well-known phenomenon in oil-lubricated transmissions is the unavoidable mixing of air with the oil during operation. The so-called oil-air-dispersion that occurs can be measured on the basis of the air bubble size and air bubble size distribution in the oil in a dispersion spectrum that occurs depends on geometry, speed and torque. Due to the increase in speed by several orders of magnitude in electrified vehicles, the speed- and torque-based vibration excitation of the transmission changes both in the excitation frequencies and in the excitation amplitudes. This brings physical effects into focus that previously played no role in drive technology. One of these physical effects is vibration-induced cavitation, which generates high pressures and temperatures and has negative effects on both the oils used and the mechanical components. The vibration behavior of air bubbles in oil is calculated using the Gilmore model from a realistic bubble size and relevant excitation frequencies. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Internal combustion engines

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Test bench for the investigation of road temperature measurement

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measurement: sensors 2025年

作者： Marin, Sebastian Fröhlich, Thomas Augustin, Silke Schalles, Marc Krapf, Gunter Beerel, Joseph Technische Universität Ilmenau Institute of Process Measurement and Sensor Technology IlmenauPF 100 565 Germany

The road temperature is used as an indicator for the winter maintenance service. Consequently, it should be determinated within a known measurement uncertainty. Investigations in road weather stations revealed inconsistencies in the evaluation of the road temperature according to different measurement principles. In order to systematically investigate the differences that occurred in the measured road surface temperature, a test bench that enables simulation of the road temperature and the ambient conditions was built. This test bench will be presented in this article. © 2024

关键词： Surface temperature

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