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Dynamic modeling of additive manufacturing process chains for end-use part manufacturing

Procedia CIRP 2021年 104卷 500-505页

作者： Mathias Wiese Antal Dér Alexander Leiden Tim Abraham Christoph Herrmann Sebastian Thiede Polymer Additive Manufacturing Center AUDI AG Auto-Union-Straße 1 Ingolstadt 85045 Germany Chair of Sustainable Manufacturing and Life Cycle Engineering Institute of Machine Tools and Production Technology Technische Universität Braunschweig Langer Kamp 19b Braunschweig 38106 Germany Fraunhofer Institute for Surface Engineering and Thin Films (IST) Bienroder Weg 54 E Braunschweig 38108 Germany Chair of Manufacturing Systems Department Design Production and Management University of Twente Drienerlolaan 5 Enschede 7522NB The Netherlands

Integration of additive manufacturing (AM) into series production demands for comprehensive methods and tools. An agent-based process chain simulation framework is proposed to embed AM into a cyber-physical production system. A multi-dimensional evaluation supports the planning of AM process chains as well as their day-to-day operation. The detailed evaluation possibilities down to product and single simulation event level are illustrated by a case study, in which an automotive exterior part is produced using the multi-jet fusion technology. Multiple possible process chain configurations are assessed based on their modeled key performance indicators, summarized in a energy value stream map.

关键词： Additive manufacturing Process chain simulation Rapid manufacturing Cyber-physical production systems Energy value stream analysis Multi-jet fusion

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Carotid Sound Signal Artifact Detection based on Discrete Wavelet Transform Decomposition

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Current Directions in Biomedical engineering 2021年第2期7卷 299-302页

作者： Fuentealba, Patricio Salvi, Rutuja Henze, Jasmin Burmann, Anja Boese, Axel Ataide, Elmer Spiller, Moritz Illanes, Alfredo Friebe, Michael IDTM GmbH Recklinghausen Germany Instituto de Electricidad y Electrónica Facultad de Ciencias de la Ingeniería Universidad Austral de Chile Valdivia Chile Fraunhofer Institute for Software and Systems Engineering Dortmund Germany HealthTec Innovation Laboratory Otto-von-Guericke-University + MEDICS GmbH Magdeburg Germany Division of Nuclear Medicine Department of Radiology + INKA Application Driven Research Innovation Laboratory Otto-von-Guericke University Magdeburg Germany HealthTec Innovation Laboratory Surgical Audio Guidance Otto-von-Guericke-University Magdeburg Germany HealthTec Innovation Laboratory Otto-von- Guericke-University Magdeburg + IDTM GmbH Recklinghausen Germany

Auscultation methods allow a non-invasive diagnosis of cardiovascular diseases like atherosclerosis based on blood flow sounds of the carotid arteries. Since this process is highly dependent on the clinician's experience, it is of great interest to develop automated data processing techniques for objective assessment. We have recently proposed a computerassisted auscultation system that we use to acquire carotid blood flow sounds. In this work, we present an approach for detecting artifacts within the blood flow sound caused by swallowing or coughing events. For this purpose, we first decompose the signal using a discrete wavelet transform (DTW). Then, we compute an energy ratio between the DWT scales associated with the signal information with and without artifacts using a sliding window of 1 s length. Evaluation based on Kruskal-Wallis and Wilcoxon rank-sum tests shows a statistically significant difference (p-value © 2021 by Walter de Gruyter Berlin/Boston.

关键词： Discrete wavelet transforms

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Utilizing Acoustic Emission Signals to Evaluate BEoL Stack Damages of Two Different Sample systems Caused by Cu-Pillar Shear-Off

Utilizing Acoustic Emission Signals to Evaluate BEoL Stack D...

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IEEE International Workshop Integrated Reliability

作者： Jendrik Silomon André Clausner Ehrenfried Zschech Group Innovation – Special Materials and Surface Engineering Volkswagen AG Wolfsburg Germany Microelectronics and Nanoanalytic Fraunhofer Institute for Ceramic Technologies and Systems IKTS Dresden Germany

ISBN: (数字)9781728170589

ISBN: (纸本)9781728170596

In this work, a novel approach is introduced to identify and categorize damages occurring in the back end of line (BEoL) stack utilizing acoustic emission (AE) measurements. The damages in this experimental approach are induced by a tribo-indenter system shearing off copper (Cu-) pillars with a customized tip. The research focuses on the comparison of the acoustic signals of two sample systems manufactured by GLOBALFOUNDRIES. One test vehicle (TV) is a 28 nm technology chip bumped with round Cu-pillars and the other one a 22 nm technology chip bumped with oblong pillars. Several Cu-pillar shear-off experiments with different parameters were performed on single Cu-pillars of both sample systems. To trigger different damage modes, the shear height on the round pillars was varied as well as the shear angle on the oblong pillars. The force-progression over time and the AE signal during the shear process were recorded and aligned with the resulting damage. The acoustic emission data was analyzed further by comparing the shape, the amplitude, and the occurring frequencies of the respective signals. For the latter, a Fast Fourier Transformation (FFT) was applied. The different AE signals showed specific characteristics depending on the damage mode and the sample system used. These results suggest that the AE technique is a suitable tool to provide valuable additional information regarding the BEoL stack stability evaluation.

关键词： Force Shape Acoustics Acoustic measurements TV Stability criteria Acoustic emission

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The channel as a traffic Sensor: Vehicle detection and classification based on radio fingerprinting

arXiv

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arXiv 2020年

作者： Sliwa, Benjamin Piatkowski, Nico Wietfeld, Christian Communication Networks Institute TU Dortmund University Dortmund44227 Germany Media Engineering Group Fraunhofer Institute for Intelligent Analysis and Information Systems IAIS Sankt Augustin53757 Germany

—Ubiquitously deployed Internet of Things (IoT)based automatic vehicle classification systems will catalyze data-driven traffic flow optimization in future smart cities and will transform the road infrastructure itself into a dynamically sensing Cyber-physical System (CPS). Although a wide range of different traffic sensing systems has been proposed, the existing solutions are not yet able to simultaneously satisfy the multitude of requirements, e.g., accuracy, robustness, cost-efficiency, and privacy preservation. In this paper, we present a novel approach, which exploits radio fingerprints – multidimensional attenuation patterns of wireless signals – for accurate and robust vehicle detection and classification. The proposed system can be deployed in a highly cost-efficient manner as it relies on off-the-shelf embedded devices which are installed into existing delineator posts. In a comprehensive field evaluation campaign, the performance of the radio fingerprinting-based approach is analyzed within an experimental live deployment on a German highway, where it is able to achieve a binary classification success ratio of more than 99% and an overall accuracy of 93.83% for a classification task with seven different classes. Copyright © 2020, The Authors. All rights reserved.

关键词： Intelligent systems

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Design and fabrication of 4h-sic mosfets with optimized jfet and p-body design

Design and fabrication of 4h-sic mosfets with optimized jfet...

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Asia-Pacific Conference on Silicon Carbide and Related Materials, APCSCRM 2019

作者： Ni, Weijiang Wang, Xiaoliang Feng, Chun Xiao, Hongling Jiang, Lijuan Li, Wei Wang, Quan Li, Mingshan Schlichting, Holger Erlbacher, Tobias Key Lab of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences Beijing100083 China Center of Materials Science and Optoelectronics Engineering and School of Microelectronics University of Chinese Academy of Sciences Beijing100083 China Beijing Century Goldray Semiconductor Co. Ltd Beijing100176 China Fraunhofer Institute for Integrated Systems and Device Technology IISB Erlangen91058 Germany

ISBN: (纸本)9783035736427

In this paper, 4H-SiC planar MOSFETs were designed and fabricated. By using TCAD tool, the trade-off between on-resistance and maximum gate oxide electric field was optimized. With optimized gate oxide growth process, the gate oxide’s critical electric field of 9.8 MV/cm and the effective barrier height of 2.57 eV between SiO2 and 4H-SiC were obtained. The field effective mobility with different p-body doping was compared and studied. The MOS interface state density of 1.12E12 cm-2 eV-1 at EC-EIT = 0.21 eV and channel mobility of 19.3 cm2 /Vs at VGS = 20 V were obtained. The fabricated MOSFET’s on-resistance of 6.4 mΩcm2 was obtained with hexagonal cell structure which is very consistent with the simulation results. © 2020 Trans Tech Publications Ltd, Switzerland.

关键词： Silicon carbide

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Ultrafast tm-doped fiber cpa system delivering gw-level peak power pulses at 100 w average power

Ultrafast tm-doped fiber cpa system delivering gw-level peak...

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Specialty Optical Fibers, SOF 2020

作者： Wang, Ziyao Heuermann, Tobias Gebhardt, Martin Lenski, Mathias Gaida, Christian Jauregui, Cesar Limpert, Jens Institute of Applied Physics Abbe Center of Photonics Friedrich-Schiller-Universitat Jena Albert-Einstein-Str. 15 Jena07745 Germany Helmholtz-Institute Jena Frobelstieg 3 Jena07743 Germany Active Fiber Systems GmbH Ernst-Ruska-Ring 11 Jena07745 Germany Fraunhofer Institute for Applied Optics and Precision Engineering Albert-Einstein-Str. 7 Jena07745 Germany

In this contribution, we present a Tm-doped fiber chirped pulse amplifier system delivering 108 W of average output power at 417 kHz repetition rate with 250 fs pulse duration and close to 1 GW of pulse peak power. &#... 详细信息

ISBN: (纸本)9781943580798

关键词： Pulse repetition rate

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Mid-infrared frequency combs and staggered spectral patterns in χ(2)microresonators

arXiv

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arXiv 2022年

作者： Amiune, Nicolas Fan, Zhiwei Pankratov, Vladislav V. Puzyrev, Danila N. Skryabin, Dmitry V. Zawilski, Kevin T. Schunemann, Peter G. Breunig, Ingo Laboratory for Optical Systems Department of Microsystems Engineering-IMTEK University of Freiburg Georges-Köhler-Allee 102 Freiburg79110 Germany Department of Physics University of Bath England BathBA2 7AY United Kingdom BAE Systems Inc. MER15-1813 P.O. Box 868 NashuaNH03061-0868 United States Fraunhofer Institute for Physical Measurement Techniques IPM Georges-Köhler-Allee 301 Freiburg79110 Germany

The potential of frequency comb spectroscopy has aroused great interest in generating mid-infrared frequency combs in the integrated photonic setting. However, despite remarkable progress in microresonators and quantum cascade lasers, the availability of suitable mid-IR comb sources remains scarce. Here, we present a new approach for the generation of mid-IR microcombs through cascaded three-wave-mixing. By pumping a CdSiP2microresonator at 1.55 μm wavelength with a low power continuous wave laser, we generate χ(2)frequency combs at 3.1 μm wavelength, with a span of about 30 nm. We observe ordinary combs states with a line spacing of the free spectral range of the resonator, and combs where the sideband numbers around the pump and half-harmonic alternate, forming staggered patterns of spectral lines. Our scheme for mid-IR microcomb generation is compatible with integrated telecom lasers. Therefore, it has the potential to be used as a simple and fully integrated mid-IR comb source, relying on only one single material. © 2022, CC BY.

关键词： Quantum cascade lasers

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Sub-2-Cycle Carrier-Envelope-Phasestabilized 110W, 1.1mJ Laser

Sub-2-Cycle Carrier-Envelope-Phasestabilized 110W, 1.1mJ Las...

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Advanced Solid State Lasers, ASSL 2021 - Part of Laser Congress, LAC 2021

作者： Hädrich, Steffen Tschernajew, Maxim Shestaev, Evgeny Stutzki, Fabian Walther, Nico Just, Florian Karl, Florian Herrfurth, Oliver Seres, Imre Jójárt, Péter Várallyay, Zoltán Börzsönyi, Adám Müller, Michael Grebing, Christian Hoff, Dominik Eidam, Tino Limpert, Jens Active Fiber Systems GmbH Ernst-Ruska-Ring 17 Jena07745 Germany Abbe Center of Photonics Institute of Applied Physics Friedrich-Schiller-University Jena Albert-Einstein-Str. 15 Jena07745 Germany ELI-ALPS ELI-HU Non-Profit Ltd. H-6728 Szeged Wolfgang Sandner utca 3. Hungary Fraunhofer Institute for Applied Optics and Precision Engineering Albert-Einstein-Str. 7 Jena07745 Germany Single Cycle Instruments Hans-Knöll-Str.6 Jena07745 Germany Helmholtz-Institute Jena Fröbelstieg 3 Jena07743 Germany

ISBN: (纸本)9781557528209

We present a sub-2 cycle laser system combining high average power, pulse energy and repetition rate with CEP-stable operation making this system an ideal driver for next-generation attosecond sources. The system is based on a fiber-chirped pulse amplification system incorporating coherent combination of 8 amplifier channels. The latter emits 300fs pulses, which are post-compressed down to the few-cycle regime in a two-stage multi-pass cell (MPC) nonlinear pulse compression. The first multi-pass cell is based on standard dielectric mirrors and achieves 1.7mJ, © 2021 The Author(s).

关键词： Pulse repetition rate

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Fine structure of second-harmonic resonances in χ(2) optical microresonators

arXiv

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arXiv 2021年

作者： Szabados, Jan Amiune, Nicolás Sturman, Boris Breunig, Ingo Laboratory for Optical Systems Department of Microsystems Engineering - IMTEK University of Freiburg Georges-Köhler-Allee 102 Freiburg79110 Germany Institute of Automation and Electrometry Russian Academy of Sciences Koptyug Avenue 1 Novosibirsk630090 Russia Fraunhofer Institute for Physical Measurement Techniques IPM Georges-Köhler-Allee 301 Freiburg79110 Germany

Owing to the discrete frequency spectrum of whispering gallery resonators (WGRs), the resonance and phase-matching conditions for the interacting waves in the case of second-harmonic generation (SHG) cannot generally be fulfilled simultaneously. To account for this, we develop a model describing SHG in WGRs with non-zero frequency detunings at both the pump and second-harmonic frequencies. Our model predicts strong distortions of the line shape of pump and second-harmonic resonances for similar linewidths at both frequencies;for much larger linewidths at the second-harmonic frequency, this behavior is absent. Furthermore, it describes the SHG efficiency as a function of detuning. Experimentally, one can change the WGR eigenfrequencies, and thus the relative detuning between pump and second-harmonic waves by a number of means, for example electro-optically and thermally. Using a lithium niobate WGR, we show an excellent quantitative agreement for the SHG efficiency between our experimental results and the model. Also, we show the predicted distortions of the pump and second-harmonic resonances to be absent in the lithium niobate WGR, but present in a cadmium silicon phosphide WGR, as expected from the linewidths of the resonances involved. Copyright © 2021, The Authors. All rights reserved.

关键词： Nonlinear optics

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Studying Drink-Serving Service Robots in the Real World*

Studying Drink-Serving Service Robots in the Real World*

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IEEE International Workshop on Robot and Human Communication (ROMAN)

作者： Rosalyn Melissa Langedijk Cagatay Odabasi Kerstin Fischer Birgit Graf Department of Design & Communication University of Southern Denmark Sønderborg Denmark Department of Robot and Assistive Systems Fraunhofer-Institute for Production Engineering and Automation IPA Stuttgart Germany

ISBN: (数字)9781728160757

ISBN: (纸本)9781728160764

Field studies where robots are tested in real life settings bring different challenges for researchers, robotics scientists and users. In this paper, we address some of the challenges we encountered when testing two different drink-serving service robots in the wild. We collect challenges from three different experiments. Two experiments were conducted in elderly care facilities, while a third experiment took place in the lobby of a concert hall. We focus on the challenges that researchers face during the preparation phase and the on-set deployment phase when testing robots in the wild. We point to potential difficulties that may arise and present some practical solutions to the issues encountered. Our results suggest that lab studies do not sufficiently prepare the researcher for research 'in the wild'.

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