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arXiv 2020年

作者： Fox, Colin Cui, Tiangang Neumayer, Markus Department of Physics University of Otago Dunedin New Zealand School of Mathematics Monash University Melbourne Australia Institute of Electrical Measurement and Sensor Systems Graz University of Technology Graz Austria

Bayesian modelling and computational inference by Markov chain Monte Carlo (MCMC) is a principled framework for large-scale uncertainty quantification, though is limited in practice by computational cost when implemented in the simplest form that requires simulating an accurate computer model at each iteration of the MCMC. The delayed acceptance Metropolis–Hastings MCMC leverages a reduced model for the forward map to lower the compute cost per iteration, though necessarily reduces statistical efficiency that can, without care, lead to no reduction in the computational cost of computing estimates to a desired accuracy. Randomizing the reduced model for the forward map can dramatically improve computational efficiency, by maintaining the low cost per iteration but also avoiding appreciable loss of statistical efficiency. Randomized maps are constructed by a posteriori adaptive tuning of a randomized and locally-corrected deterministic reduced model. Equivalently, the approximated posterior distribution may be viewed as induced by a modified likelihood function for use with the reduced map, with parameters tuned to optimize the quality of the approximation to the correct posterior distribution. Conditions for adaptive MCMC algorithms allow practical approximations and algorithms that have guaranteed ergodicity for the target distribution. Good statistical and computational efficiencies are demonstrated in examples of calibration of large-scale numerical models of geothermal reservoirs and electrical capacitance tomography. Copyright © 2020, The Authors. All rights reserved.

关键词： Computational efficiency

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Recapitulation and comparative study for Photovoltaic Maximum Power Point Tracking techniques in particular sensor quality

Recapitulation and comparative study for Photovoltaic Maximu...

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IEEE Palestinian International Conference on Electrical and Computer Engineering (PICECE)

作者： Hala Jarallah El Khozondar Lee Jun yong Alexander W. Koch Islamic University of Gaza Gaza Plestine Institute for Measurement Systems and Sensor Technology German Institute for Science and Technology Singapore Institute for Measurement Systems and Sensor Technology Technische Universitaet Muenchen TUM Muenchen Germany

In this study, a review on several maximum power point tracking (MPPT) algorithms is given. MPPT algorithms have three major categories: Conventional methods, Advanced Soft Computing methods and Hybrid algorithms. MPPT algorithms are significant to operate the photovoltaic energy conversion systems as close as possible to the MPP resulting in photovoltaic (PV) arrays with high efficiency. In this review, the MPPT algorithms implementation complexity, the complete procedure and its effects in the PV output were given with special attention to the sensors used in the system in the first portion. Further, different MPPT algorithms for PV systems are highlighted with examples, it's parameters like complexity, and sensors used are described. In the end, the MPPT algorithms for PV systems were compared, reviewed and reported. The ultimatum of this work is to provide a survey reference for users of PV based power generation and valued information for researchers of this particular field.

关键词： Maximum power point trackers Complexity theory Photovoltaic systems Artificial neural networks Fuzzy logic Solar energy

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Influence of different cooling strategies during hard turning of AISI 52100 - part I: thermo-mechanical load, tool wear, surface topography and manufacturing accuracy

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Procedia CIRP 2020年 87卷 77-82页

作者： Stephan Basten Benjamin Kirsch Werner Ankener Marek Smaga Tilmann Beck Julian Uebel Jörg Seewig Jan C. Aurich Institute for Manufacturing Technology and Production Systems TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany Institute of Materials Science and Engineering TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany Institute for Measurement and Sensor Technology TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany

This paper presents a characterization of the turning process for finishing of AISI 52100 in martensitic heat treatment state at various cooling conditions. With regard to the cooling conditions, LN 2 -cooling, CO 2 snow cooling at varied mass flows, sub-zero metalworking fluids (MWF) at varied supply temperatures, and dry machining were examined. The tool temperatures, the process forces, the tool wear, the surface topography as well as the dimensional deviations of the workpiece caused by unintended alterations of the depth of cut due to a thermal expansion or contraction of the workpiece are analyzed. The application of MWF supplied at 20 °C results in an unchanging thermo-mechanical load in the tool-work interface and surface topography as well as in a high manufacturing accuracy. Dry machining leads to an increasing depth of cut of up to 10 %, resulting in radial dimensional errors. Cryogenic machining and using the sub-zero MWF supplied at -30 °C exhibit a different behavior due to high cooling effects: the depth of cut is reduced up to 10 %, also leading to radial dimensional errors. However, even though the depth of cut and thus the undeformed chip cross section is affected by up to 10 % depending the cooling condition, the mechanical load remains approximately constant during single cuts. In part II, the surface and near surface microstructure morphology of the workpieces is characterized.

关键词： cryogenic turning surface integrity accuracy error hard machining precicion turning

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Influence of different cooling strategies during hard turning of AISI 52100 – part II: characterization of the surface and near surface microstructure morphology

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Procedia CIRP 2020年 87卷 119-124页

作者： Werner Ankener Julian Uebel Stephan Basten Marek Smaga Benjamin Kirsch Jörg Seewig Jan C. Aurich Tilmann Beck Institute of Materials Science and Engineering TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany Institute for Measurement and Sensor Technology TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany Institute for Manufacturing Technology and Production Systems TU Kaiserslautern Gottlieb-Daimler-Str. 67663 Kaiserslautern Germany

This two-part paper addresses the impact of seven different cooling conditions on the finishing process as well as the resulting surface and near-surface microstructure morphology of the rolling bearing steel AISI 52100 in martensitic heat treatment state. The applied cooling strategies are liquid nitrogen (LN 2 -) cooling, CO 2 -snow cooling at varied mass flows, sub-zero metalworking fluids (MWF) at varied supply temperatures, and dry machining. Part II of the paper concerns the changes in surface roughness, examined by an angle resolved scatter light sensor, micro hardness measurement, microstructure observations, residual stress and phase composition analyses in the near-surface area, caused by the turning process, that is characterized in Part I. The lowest cooling performance, i.e. dry machining, results in low compressive axial residual stresses and a high proportion of retained austenite at the near-surface area. High cooling performance strategies like CO 2 cooling or sub-zero MWF show an opposite distribution of the mentioned parameters, wherein the coolants’ lubrication effect is an important aspect. Microstructural differences resulting from the process parameters used in these investigations tend to be less significant. Thus, they do not allow reliable assignment of the microstructure to the cooling strategies used. However, different cooling conditions show an impact on residual stresses, phase distribution and surface topography of the workpieces to varying extents.

关键词： cryogenic turning surface integrity micro structure

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Tracking of Magnetic Micromotors in Confined Channels Through Scattering Tissue

Tracking of Magnetic Micromotors in Confined Channels Throug...

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IEEE International Conference on Nano/Molecular Medicine and Engineering (NANOMED)

作者： Azaam Aziz Dmitriy Karnaushenko Nektarios Koukourakis Jürgen W. Czarske Oliver G. Schmidt Mariana Medina-Sánchez Institute for Integrative Nanosciences Leibniz Institute for Solid State and Materials Research Dresden Germany Chair of Measurement and Sensor System Technique and Competence Center BIOLAS TU Dresden School of Engineering Dresden Germany Cluster of Excellence Physics of Life TU Dresden Germany and Faculty of Physics School of Science Dresden TU Germany Professorship of Material Systems for Nanoelectronics Chemnitz University of Technology Chemnitz Germany

ISBN: (纸本)9781665458573

The field of small-scale microdevices is growing rapidly towards the development of tethered/untethered microsensors and therapeutic agents that can move through narrow vascular networks in living organisms to diagnose and treat for example vascular diseases. However, imaging and localization of such microdevices are challenging under scattering tissue due to the lack of high spatial and temporal resolution that compromises the penetration depth and therefore the application scenario. Here, we report the tracking of magnetically-driven rolling micromotors (20 µm in diameter) through scattering tissue (1.2 mm thickness) using reflective infrared (IR) imaging. This technique provides high spatiotemporal resolution for the tracking of micro-agents in a narrow vascular network. As a potential application, we suggest the use of such micro-agents as micro-viscosimeters, in which by analyzing their dynamics, one can extract some basic information on the surrounding fluid properties which might be related to certain health status.

关键词： Stimulated emission Fluid dynamics Scattering Optical imaging Spatiotemporal phenomena Optical scattering Optical reflection

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Erratum to “Static and Dynamic Pressure measurement in Flight Test Application With Optical Fabry–Pérot sensors”

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IEEE Transactions on Instrumentation and measurement 2021年 70卷

作者： Sascha U. Kienitz Laura Lohr Markus J. Schmid Alexander W. Koch PolyTech Wind Power Technology Germany GmbH Munich Germany Institute for Measurement Systems and Sensor Technology Technical University Munich Munich Germany

In the above article [1] , (5) on page 3, a typo was observed when preparing a new manuscript. This equation was added with respect to the decision of major revision. The initial template for the revision contained the correct formulae, but based on most likely a formatting issue on the main author’s side from with (4), the equation was mixed up with (5). Unfortunately, this mistake was not observed by reviewers or the coauthors.

关键词： Optical variables measurement Adaptive optics Pressure measurement Optical sensors

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Rapid Fault Diagnosis of Photovoltaic Panels Under Outdoor Environmental Conditions

Rapid Fault Diagnosis of Photovoltaic Panels Under Outdoor E...

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IEEE Instrumentation and measurement technology Conference

作者： Christian Schuss Kari Remes Kimmo Leppänen Juha Saarela Tapio Fabritius Bernd Eichberger Timo Rahkonen Optoelectronics and Measurement Techniques (OPEM) Research Unit University of Oulu Finland Mettler-Toledo GmbH SBU AutoChem Switzerland Institute of Electronic Sensor Systems Graz University of Technology Austria Circuits and Systems (CAS) Research Unit University of Oulu Finland

ISBN: (数字)9781728144603

ISBN: (纸本)9781728144610

This paper investigates opportunities to rapidly detect defects in photovoltaic (PV) panels. It is worth noting that a defect in a single PV cell can significantly reduce the output power of a PV panel and, thereby, of an entire PV array. Hence, it is crucial to detect faults in PV panels and replace them within PV power plants. In this paper, we utilise synchronized thermography (ST) to obtain infrared (IR) images under outdoor environmental conditions. We illustrate how IR-images obtained under changing irradiation and different angles can be analysed to rapidly detect defects in PV panels. Our technique allows maintenance staff to quickly identify PV panels with defects on the site of a PV power plant.

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Mechanical properties of an adjustable weighing cell prototype 19

Mechanical properties of an adjustable weighing cell prototy...

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19th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2019

作者： Darnieder, Maximilian Pabst, Markus Fröhlich, Thomas Zentner, Lena Theska, René Department of Mechanical Engineering Technische Universität Ilmenau Institute for Design and Precision Engineering Precision Engineering Group Department of Mechanical Engineering Technische Universität Ilmenau Institute for Process Measurement and Sensor Technology Process Measurement Technology Group Germany Department of Mechanical Engineering Technische Universität Ilmenau Compliant Systems Group Germany

ISBN: (纸本)9780995775145

Weighing cells based on the principle of electromagnetic force compensation are highly sensitive force measuring devices. A compliant mechanism with thin flexure hinges constitutes the mechanical basis of the balance. The weighing cells are the core components of high-performance vacuum mass comparators, e.g. for the comparison of one kilogram mass standards. According to the mechanical models, the achievable sensitivity of the measurement device is only limited by the adjustment resolution. Without further measures, the vertical adjustment of small trim masses represents a trade-off between resolution and tilt sensitivity. The numerical test of the underlying adjustment concept by finite element models reveals that the objectives of a high sensitivity and a low tilt sensitivity can be achieved simultaneously by a meaningful combination of adjustment measures. This represents a promising concept for the further enhancement of vacuum mass comparators. The prototypes are planar weighing cell structures for a flexible choice of the manufacturing process. The planar mechanism facilitates the comparison between models and measurements. The weighing cells for a nominal mass of 300g are experimentally investigated. The measurement of tilt reactions is enabled by the use of a precision tilt table as base for the weighing cell. Properties like stiffness and tilt sensitivity are determined as a function of the adjustment parameters. This way the mechanical models are verified, and the property enhancement of the weighing cell is evaluated. © 2019 European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 19th International Conference and Exhibition, EUSPEN 2019. All rights reserved.

关键词： Cells

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Frequency Band Broadening and Charge Density Enhancement of a Vibrational Triboelectric Nanogenerator with Two Stoppers

SSRN

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SSRN 2022年

作者： Qi, Youchao Liu, Guoxu Kuang, Yang Wang, Lu Zeng, Jianhua Lin, Yuan Zhou, Han Zhu, Meiling Zhang, Chi CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and Sensor Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing101400 China College of Engineering Mathematics and Physical Sciences University of Exeter ExeterEX4 4QF United Kingdom School of Nanoscience and Technology University of Chinese Academy of Sciences Beijing100049 China State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies Collaborative Innovation Center of Suzhou Nano Science and Technology Xi’an Jiaotong University Xi’an710049 China Center on Nanoenergy Research School of Physical Science and Technology Guangxi University China

Vibrational triboelectric nanogenerators (V-TENG) can be used to harvest broadband vibration energy due to the nonlinear impact force induced by a stopper. However, V-TENGs with a single stopper have limited bandwidth and surface charge density, which has limited their application in wideband vibration energy harvesting. Herein, a V-TENG with two stoppers is proposed for frequency band broadening and charge density enhancement. The theoretical analysis and experimental validation have indicated the V-TENG with two stoppers could improve the bandwidth by 75% compared with one stopper at a gap distance of 0.5 mm. Moreover, a charge pump can be constructed with two output channels, which has improved surface charge density by about 14 times. With the frequency varying from 18 to 38 Hz, the V-TENG can continually power 400 LEDs and charge a commercial capacitor quickly. This work has shown an encouraging method for enhancing the performance of V-TENGs, which also has great prospects in harvesting wideband vibration energy from machines, cars, ships, and human motions for self-powered electronics. © 2022, The Authors. All rights reserved.

关键词： Nanogenerators

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Trans-scale Nanofabrication with Nanopositioning and Nanomeasuring Machines

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IFAC-PapersOnLine 2019年第15期52卷 151-156页

作者： Andreas Meister Laura Weidenfeller Johannes Kirchner Martin Hofmann Rostyslav Mastylo Roland Füßl Johann Reger Eberhard Manske Institute for Process Measurement and Sensor Technology Technische Universität Ilmenau Germany Institute for Automation and Systems Engineering Technische Universität Ilmenau Germany Institute of Microelectronics and Nanoelectronics Technische Universität Ilmenau Germany

Nanofabrication in macroscopic working areas addresses the manipulation with nanometer precision in large scale working areas of several hundred millimeters. In order to reduce the fabrication time of large objects, high dynamic position tracking is required. The position and orientation of the nanopositioning and nanomeasuring machine have to be controlled permanently to compensate external disturbances like ground motion, sound waves, et cetera. Many applications have strict demands on following the track, e.g. to reduce the line roughness. High performant data and signal processing and efficient control algorithms are required to overcome these challenges. This work presents the nanopositioning and measuring machine as well as the utilized control system. Several scanning and fabrication experiments have been carried out in order to demonstrate the performance of the setup.

关键词： Precision systems, Micro-/Nanosystems sensors measurement systems

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