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

作者： Zhang, Hao Kuschmierz, Robert Löser, Michael Ihlenfeldt, Steffen Shi, Shengyu Czarske, Jürgen Laboratory of Measurement and Sensor System Techniques Technische Universität Dresden Dresden01062 Germany Institute of Mechatronic Engineering TU Dresden Dresden Germany Key Laboratory of Polymer Processing Engineering of Ministry of Education National Engineering Research Center of Novel Equipment for Polymer Processing School of Mechanical and Automobile Engineering South China University of Technology Guangzhou510640 China

ISBN: (纸本)9780995775145

Vibrations of milling tools, especially of slender end mills, are one of the main contributors to shape deviations of machined work pieces in the milling process. For milling machines, the vibration behaviour depends on the spindle speed and end mill properties. Numerical models can help to predict vibrational behaviour and reduce vibrations. This requires measuring the frequency response of the end mill. We propose a system for investigating the frequency response function inside of a milling machine under different rotational speeds. It consists of an automated impact unit generating vibrations with a known force and a novel Mach-Zehnder interferometer based sensor. The sensor enables simultaneous axial distance and lateral velocity measurement at fast rotating surfaces with submicron uncertainty and measurement rates up to 50 kHz. The bidirectional vibration frequencies are estimated by the signal-processing algorithm depending on the geometric relationship of the displacement in two directions. © 2019 European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 19th International Conference and Exhibition, EUSPEN 2019. All rights reserved.

关键词： Frequency response

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Dynamic adaptive optical image correction for velocimetry

Dynamic adaptive optical image correction for velocimetry

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Adaptive Optics: Analysis, Methods & systems, AOMS 2018

作者： Büttner, Lars Teich, Martin Radner, Hannes Czarske, Jürgen Technische Universität Dresden Faculty of Electrical and Computer Engineering Laboratory of Measurement and Sensor System Techniques Helmholtzstraße 18 Dresden01069 Germany

Imaging, correlation-based velocity measurements through time-varying optical distortions are presented for application in microfluidics. Using a deformable membrane mirror and an iterative FPGA-based optimization pro... 详细信息

ISBN: (纸本)9781943580446

关键词： Geometrical optics

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Miniaturized interferometric 3-D sensor for shape measurement inside of cutting lathes

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Procedia CIRP 2018年 77卷 46-49页

作者： Hao Zhang Robert Kuschmierz Jürgen Czarske Laboratory of Measurement and Sensor System Techniques Faculty of Electrical and Computer Engineering Technische Universität Dresden Dresden 01062 Germany

We propose an in-situ coordinate measurement machine based on a Mach-Zehnder interferometer. The sensor system enables the simultaneous measurement of axial distance and lateral velocity at rough and fast rotating objects. This allows to guarantee ever-decreasing tolerances, measurements of surface profile, roundness and absolute diameter of workpieces inside of lathes. With a camera based detection, measurement uncertainties below 100 nm can be achieved. Furthermore, cameras allow an in-situ calibration of the measurement system. By employing coherent fiber bundles, a robust probe without active parts in the lathe was realized. An extended measurement volume was achieved for a 3-D shape measurement without scanning.

关键词： in-situ on-line shape diameter metrology interferometry control of machining operations

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Ultrasound flow mapping of 3D turbulent liquid metal flows

Ultrasound flow mapping of 3D turbulent liquid metal flows

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2017 IEEE International Ultrasonics Symposium, IUS 2017

作者： Thieme, Norman Buchner, Karl Nauber, Richard Buttner, Lars Patzold, Olf Czarske, Jurgen Laboratory for Measurement and Sensor System Techniques TU Dresden Germany TU Freiberg Germany

ISBN: (纸本)9781538633830

Conductive fluids, e.g. metallic melts, can be driven by magnetic fields, which is a branch of magnetohydrodynamics (MHD). MHD can be used for driving a melt flow during the crystal growth of photovoltaic silicon in order to improve the mass and heat transfer in the melt for better structural and electrical properties of the silicon crystals. However, the optimal application of MHD requires a good understanding of the flow, which is generally complex and unsteady during crystal growth. Substantial knowledge about the flow is usually gained through numerical simulations and MHD model experiments at room temperature. For model experiments, a comprehensive flow mapping of complex and unsteady flow phenomena is required. © 2017 IEEE.

关键词： Magnetic field measurement Ultrasonic variables measurement Magnetohydrodynamics Metals Fluid flow measurement Ultrasonic imaging Magnetic fields

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Investigation of the propagation of measurement uncertainty in two-step method 18

Investigation of the propagation of measurement uncertainty ...

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18th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2018

作者： Shi, Shengyu Kuschmierz, Robert Czarske, Jürgen Qu, Jinping Zhang, Hao Lin, Jing Key Laboratory of Polymer Processing Engineering of Ministry of Education National Engineering Research Center of Novel Equipment for Polymer Processing School of Mechanical and Automobile Engineering South China University of Technology Guangzhou510640 China Laboratory for Measurement and Sensor System Techniques Technische Universitat Dresden Dresden01069 Germany State Key Laboratory for Manufacturing System Engineering School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China School of Reliability and Systems Engineering Beihang University Xueyuan Road No. 37 Haidian District Beijing China

ISBN: (纸本)9780995775121

The multi-step method is one of the most classical error separation techniques capable of recovering the spindle error and the roundness error from the composite probe signals. However, its accuracy decreases due to the harmonic suppression problem (HSP). Increasing the number of measurements can reduce the suppressed harmonics, but leads to lengthy measurement procedure. For simplifying the measurement procedure, the two-step method (TSM) was proposed by utilizing the harmonic calculation. Unfortunately, TSM is also subject to HSP. Hence, the focus of this paper is to reveal the mechanism of HSP in TSM, from the perspective of propagation of measurement uncertainty. To achieve this aim, first, a Laplace Transform based algorithm for TSM is proposed. Then, the system model is developed in accordance to the algorithm, and subsequently, the propagation of measurement uncertainty in TSM is theoretically analysed. Ultimately, Monte Carlo simulations are carried out for verification. © 2018 CURRAN-CONFERENCE. All rights reserved.

关键词： Laplace transforms

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Diffraction-limited axial scanning in thick biological tissue employing an aberration correcting adaptive lens

arXiv

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arXiv 2018年

作者： Philipp, Katrin Lemke, Florian Scholz, Stefan Wallrabe, Ulrike Wapler, Matthias C. Koukourakis, Nektarios Czarske, Jürgen W. Technische Universität Dresden Laboratory for Measurement and Sensor System Techniques Helmholtzstraße 18 Dresden01069 Germany University of Freiburg Laboratory for Microactuators Department of Microsystems Engineering-IMTEK Georges-Köhler-Allee 102 Freiburg79110 Germany Helmholtz Centre for Environmental ResearchUFZ Department of Bioanalytical Ecotoxicology Leipzig Germany

Diffraction-limited focusing deep into biological tissue is challenging due to spherical aberrations that lead to a broadening of the focal spot particularly in axial direction. While the diffraction-limit can be restored employing aberration correction with a deformable mirror or spatial light modulator, a bulky optical setup results due to the required beam-folding. We propose a bi actor adaptive lens, that enables axial scanning and at the same time correction of specimen induced spherical aberrations while offering a compact setup. Using the bi-actor lens in a confocal microscope, we show diffraction limited axial scanning up to 340 µm deep inside a phantom specimen. Applying this technique for in-vivo measurements of zebrafish embryos with reporter gene-driven fluorescence in the thyroid gland reveals substructures of thyroid follicles. Copyright © 2018, The Authors. All rights reserved.

关键词： Aberrations

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Wave front sensor-less adaptive optics based on sharpness metrics for particle image velocimetry

arXiv

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arXiv 2017年

作者： Teich, M. Grottke, J. Radner, H. Büttner, L. Czarske, J.W. Technische Universität Dresden Faculty of Electrical and Computer Engineering Laboratory for Measurement and Sensor System Techniques Helmholtzstrasse 18 Dresden01062 Germany

Optical distortions can significantly deteriorate the measurement accuracy in imaging systems. Such distortions can occur at fluctuating phase boundaries as well as multiple-phase flows and result from the accompanied refractive index changes. Due to multiple reflexes arising from a fluid flow setup, the usage of a wave front sensor (WFS) can be hindered. In this work we outline a wave front sensor-less approach which includes iterative aberration correction with a fast deformable mirror (DM). A combination of sharpness metric (SM) image evaluation and iterative optimization is demonstrated. The SM was measured for each image while adjusting seven Zernike modes (after Noll index enumeration) in their amplitude. The SM is used as an indicator for wave front aberrations without using a wave front sensor to correct wave front distortions that are generated by the DM. The proposed method allows for the reduction of systematic measurement uncertainties in fluid flow measurement techniques as particle image velocimetry (PIV). Five different sharpness metrics are demonstrated for reliable sharpness maximization with a deformable mirror of 69 elements. A systematic linear search (LS) algorithm was applied in order to find the optimal mirror shape. The reduction of measurement uncertainty for PIV measurements is shown. The iterative approach offers a way to reduce static or slowly changing wave front distortions in a fluid flow setup where a WFS is not applicable. Copyright © 2017, The Authors. All rights reserved.

关键词： Velocity measurement

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Transmission of multiple independent signals through a multimode fiber using optical wavefront shaping

Transmission of multiple independent signals through a multi...

引用

Adaptive Optics: Analysis, Methods and systems, AO 2016

作者： Haufe, Daniel Koukourakis, Nektarios Büttner, Lars Czarske, Jürgen W. TU Dresden Laboratory of Measurement and Sensor System Techniques Helmholtzstr. 18 Dresden01162 Germany

The transmission of multiple independent signals through a multimode fiber using individually shaped wavefronts for each signal by a segmented spatial light modulator is proposed, having perspectives due to scalabilit... 详细信息

ISBN: (纸本)9781943580156

关键词： Multimode fibers

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Transmission of individual optical signals through a multimode fiber using digital optical phase conjugation

Transmission of individual optical signals through a multimo...

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Frontiers in Optics, FiO 2016

作者： Büttner, Lars Haufe, Daniel Koukourakis, Nektarios Czarske, Jürgen W. Technische Universität Dresden Laboratory of Measurement and Sensor System Techniques Helmholtzstraße 18 Dresden01062 Germany

Transmission through a multimode fiber is demonstrated using phase conjugation. Using multiple windows of a spatial light modulator allows asynchronous imaging through the fiber. Potential for optogenetics and communi... 详细信息

ISBN: (纸本)9781943580194

关键词： Multimode fibers

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Modular ultrasound velocimeter for adaptive flow mapping in liquid metals

Modular ultrasound velocimeter for adaptive flow mapping in ...

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IEEE International Ultrasonics Symposium

作者： Richard Nauber Hannes Beyer Kevin Mader Christian Kupsch Norman Thieme Lars Buttner Jurgen Czarske Laboratory of Measurement and Sensor System Techniques (MST) TU Dresden 01062 Germany

ISBN: (纸本)9781467398985

Understanding the complex interaction of conductive fluids and time-varying magnetic fields is the main goal of research in magnetohydrodynamics (MHD). Customized magnetic fields can be used to optimize flows in technical and industrial processes involving liquid metals. For example the performance of batteries with replaceable liquid electrolytes, such as zinc slurry energy storage systems, can be improved by magnetically influencing the flow of the electrolyte. However, necessary experimental studies are often limited by the performance of flow instrumentation for opaque liquids. We present a modular research platform for flow mapping in liquid metals, the phased array ultrasound Doppler velocimeter (PAUDV). It is based on the pulsed-wave ultrasound Doppler principle in combination with the phased array technique to provide an electrically steerable sound field, enabling novel applications in MHD research. The ability to dynamically focus the ultrasound beam allows to resolve smaller flow structures in planar measurements compared to fixed-beam sensors. The PAUDV can be applied to flows in narrow channels and two velocity components can be measured with only one acoustical access via the cross beam technique. Fast electrical traversing of the measurement volume allows to obtain and visualize turbulence statistics. A two-point correlation function can be retrieved by interleaving velocity measurements at two focal points of varying distance. The PAUDV consists of a modular electronics unit with up to eight beamformer cards, capable of driving a total of 256 channels. Each channel can be individually configured regarding the excitation pattern (three-level quantization, 64 samples) and the delay (1.6 ns resolution). Data acquisition and processing is implemented on multiple FPGAs, control and data visualization are performed on a PC. The capabilities of the modular research platform PAUDV are demonstrated on measurements in the alloy gallium-indium-tin at room tempe

关键词： liquid metals Flowcharts Volume measurement velocity component velocimeters Modularity magnetohydrodynamics PHASED ARRAY techniques narrow passage Flow Doppler Ultrasonography Data visualisation data acquisition and processing magnetic field

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