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69th International Astronautical Congress: #InvolvingEveryone, IAC 2018

作者： Thiel, Markus Senese, Samuel Sedlmaier, Thomas Redlich, Daniel Mulser, Marco Van Der Veen, Egbert Jan Pambaguian, Laurent Rodrigues, GonÃ§alo Zaltron, Paolo Brinkers, Sanneke Aumund-Kopp, Claus Klein, Sebastian Domagala, Tim Kwast, Sander McLoughlin, Anthony Eick, Matthias Melzer, Christian BrÃ¼ckner, Frank Ricardo, JoÃ£o Barroqueiro, Bruno OHB System AG Manfred-Fuchs-Str. 1 WeÃŸlingD-82234 Germany ESTEC European Space Technology Centre Keplerlaan 1 AG NoordwijkNL-2200 Netherlands TNO Netherlands Organisation for Applied Scientific Research Stieltjesweg 1 DelftNL-2628CK Netherlands Fraunhofer IFAM Wiener Strasse 12 Bremen28359 Germany IABG mbH Einsteinstrasse 20 Ottobrunn85521 Germany Materialise NV Technologielaan 15 Leuven3001 Belgium SRON Netherlands Institute for Space Research Sorbonnelaan 2 UtrechtNL-3584 CA Netherlands Altair Engineering GmbH Edisonstrasse 3 UnterschleissheimD-85716 Germany RUAG Space Germany GmbH Am Glaswerk 6 CoswigD-01640 Germany Fraunhofer IWS Winterbergstrasse 28 DresdenD-01277 Germany LluleÃ¥ University of Technology LuleÃ¥971 87 Sweden Active Space Technologies S.A. Parque Industrial de Taveiro Lote 12 Coimbra3045-508 Portugal Department of Mechanical Engineering Centre for Mechanical Technology and Automation GRIDS Research Group University of Aveiro Campus UniversitÃ¡rio de Santiago Aveiro3810-193 Portugal

Additive Manufacturing (AM) technology has shown impressive new opportunities and convincing results over the last years, mainly in terrestrial applications. Today, it has proven to represent a completely new approach to shape complex mechanical parts, with enormous potential for optimization of dedicated parameters. Numerous possibilities shine up for the aerospace industry, among others, and let engineers dream of mechanical parts which only some years ago looked like science fiction. OHB system has been involved in the development of Additive Manufacturing since more than five years via several ESA studies, DLR-funded projects and by significant internal R&D activities. These projects and studies have convinced us of the potential of AM for future satellite platforms, instruments and payloads. A new dimension of freedom in generating shapes and geometries is opened, offering more flexibility for optimizing the parts and components according to functional and performance requirements. On the other hand, the efforts of qualifying an AM part to flight worthiness are significantly higher than for conventional manufacturing technologies, taking into account all the required aspects of material and production process control, inspection and testing. A concise trade-off has to be performed for each potential use case to find out whether these high efforts and resulting costs are justified by the benefits of the new technology in terms of e.g. light weighting, ease of integration and performance improvement. The paper will introduce the OHB AM roadmap, which has been developed jointly by OHB experts from both sites in Bremen and Oberpfaffenhofen, following in-depth analysis of the potential impact of the technology on space systems. It will furthermore provide an overview of applications where AM is expected to offer extraordinary opportunities. Among these 'high-potential' applications are the two following topics: â€¢ opto-mechanical assemblies (isostatic structures, o

关键词： 3D printers

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Zero Defect Manufacturing Strategies for Reduction of Scrap and Inspection Effort in Multi-stage Production systems

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Procedia CIRP 2018年 67卷 368-373页

作者： Florian Eger Daniel Coupek Davide Caputo Marcello Colledani Mariluz Penalva Jon Ander Ortiz Hermann Freiberger Gernot Kollegger Institute for Control Engineering of Machine Tools and Manufacturing Units Seidenstr. 36 Stuttgart 70174 Germany GKN Aerospace Engine Systems Norway Kirkegårdsveien 45 N-3616 Kongsberg Norway Politecnico di Milano Department of Mechanical Engineering Via la Masa 1 20156 Milan Italy Tecnalia Research & Innovation Mikeletegi 7 Donostia-San Sebastián 20009 Spain IK4-Ideko Arriaga Industrialdea 2 Elgoibar 20870 Spain ABF Industrielle Automation GmbH Deggendorfstrae 6 A-4030 Linz nxtControl GmbH Aumühlweg 3/B1 A-2544 Leobersdorf Austria

Multi-stage production systems offer a huge potential for defect compensation and defect propagation avoidance on system level, in contrast to current single-stage solutions, in order to reduce scrap and to minimize time-consuming and cost-intensive quality control. Integration of additional sensor systems and sophisticated analysis of the acquired signals enable strategies in the field of downstream compensation, inline rework and enhanced process control without including additional process and inspection stages. The presented strategies are validated in three emerging European industrial sectors (aerospace, railway and medical) yielding a universal solution for zero defect manufacturing in multi-stage production systems.

关键词： Zero-defect manufacturing Effect elimination Multi-stage Production system

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The influence of sintering process on thermal properties of nano-silver paste

The influence of sintering process on thermal properties of ...

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第十九届国际电子封装技术会议(ICEPT 2018)

作者： Wei Ke Qiaoran Zhang Xiuzhen Lu Shirong Huang Abdelhafid Zehri Johan Liu Yanpei Wu Cheng Zhou Weijuan Xia Lilei Ye SMIT Center School of Automation and Mechanical Engineering Shanghai University ShanghaiChina Electronics Materials and Systems Laboratory Department of Microtechnology and Nanoscience(MC2)Chalm SMIT Center School of Automation and Mechanical Engineering Shanghai University ShanghaiChina Elect Space Research Institute of Electronics and Information Technology Aerospace Science and Technology SHT Smart High Tech AB Hugo Grauers Gata 3ASe 411 33 GothenburgSweden

Nano-silver paste with low sintering temperature and high operation temperature was introduced to the application of bonding materials for GaN and SiC *** properties are critical issues for die attach materials due to the heat dissipation requirements of high power *** influence of sintering process parameters for nano-silver paste on the thermal properties was *** thermal conductivity of sintered nano-silver paste increased with the increase of sintering temperature and sintering time because of the dense structure due to high temperature and long sintering *** improve the thermal property,Ag coated micro-SiC particles were used as an alternative to partly replace pure nano-Ag *** results demonstrate that the SiC particles can reduce the voids and improve the density of the sintered silver ***,the addition of SiC particles can also contribute to the increase of thermal *** a result,the thermal conductivity of sintered silver paste with 1.5 wt.%Ag coated SiC particles was two times as compared to that without SiC particles with the same Ag concentration.

关键词： Thermal conductivity Sintering temperature sintering time nano-silver paste SiC particles

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Flexible Force Sensors: Electrical Breakdown-Induced Tunable Piezoresistivity in Graphene/Polyimide Nanocomposites for Flexible Force Sensor Applications (Adv. Mater. Technol. 8/2018)

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Advanced Materials Technologies 2018年第8期3卷

作者： Yonggang Jiang Mengyang Liu Xing Yan Takahito Ono Lin Feng Jun Cai Deyuan Zhang School of Mechanical Engineering and Automation Beihang University Beijing 100191 China International Research Institute for Multidisciplinary Science Beihang University Beijing 100191 China Graduate School of Engineering and Micro System Integration Center Tohoku University Sendai 980-8579 Japan

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High Direction-changing Frequency Bidirectional DC-DC Converter for Charging/Discharging Applications

High Direction-changing Frequency Bidirectional DC-DC Conver...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Ming Fu Tiecai Li Donglai Zhang Yalin Li China Shenzhen Academy of Aerospace Technology Power Electronic and Motion Control Research Center Harbin Institute of Technology Shenzhen Graduate School Shenzhen Shenzhen China School of Electrical Engineering and Automation Harbin Institute of Technology Harbin China Electrical System Engineering Department Institute of Telecommunication Satellite China Academy of Space Technology Beijing China

Based on the battery charging and discharging regulator (BCDR) in spacecraft power conditioning unit application, a bidirectional DC-DC converter BCDR with high direction-changing frequency is proposed in this paper, including the Weinberg-buck bidirectional DC-DC topology and the corresponding bidirectional control. Additionally, the test on the BCDR prototype shows that BCDR parallel modules could achieve the quick switching between charging and discharging with the direction-changing frequency meeting the requirement of 1 kHz, the regulated power bus of small voltage ripple, and high charging and discharging efficiency, in agreement with the expected design.

关键词： Integrated circuits Partial discharges Switches Batteries Power conditioning DC-DC power converters Regulators

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Improving a two-equation eddy-viscosity turbulence model to predict the aerodynamic performance of thick wind turbine airfoils

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Journal of Physics: Conference Series 2018年第1期974卷

作者： Galih Bangga Tri Kusumadewi Go Hutomo Ahmad Sabila Taurista Syawitri Herlambang Setiadi Muhamad Faisal Raditya Wiranegara Yongki Hendranata Dwi Lastomo Louis Putra Stefanus Kristiadi Institute of Aerodynamics and Gas Dynamics University of Stuttgart Stuttgart Germany Mechanical Engineering Department Institut Teknologi Sepuluh Nopember Surabaya Indonesia School of Manufacturing System and Mechanical Engineering Sirindhorn International Institute of Technology Thammasat University Thailand Toyota SO Department Astra International Ltd. Indonesia Civil Engineering Department Universitas Brawijaya Malang Indonesia Mechanical Engineering Department Universitas Muhammadiyah Surakarta Surakarta Indonesia School of Information Technology & Electrical Engineering The University of Queensland Brisbane Australia Non-Installation Top Range Department Berca Schindler Lifts Ltd. Indonesia Graduate Institute of Automation and Control National Taiwan University of Science and Technology Taiwan School of Aerospace Transport and Manufacturing Cranfield University United Kingdom Mechanical Engineering Department Texas A&M University College Station United States PUI-PT Mechatronics and Industrial Automation Research Center Intitut Teknologi Sepuluh Nopember Surabaya Indonesia Mechanical Engineering Department Politecnico di Milano Milan Italy Aeronautics Department Imperial College of Science Technology and Medicine London United Kingdom

Numerical simulations for relatively thick airfoils are carried out in the present studies. An attempt to improve the accuracy of the numerical predictions is done by adjusting the turbulent viscosity of the eddy-viscosity Menter Shear-Stress-Transport (SST) model. The modification involves the addition of a damping factor on the wall-bounded flows incorporating the ratio of the turbulent kinetic energy to its specific dissipation rate for separation detection. The results are compared with available experimental data and CFD simulations using the original Menter SST model. The present model improves the lift polar prediction even though the stall angle is still overestimated. The improvement is caused by the better prediction of separated flow under a strong adverse pressure gradient. The results show that the Reynolds stresses are damped near the wall causing variation of the logarithmic velocity profiles.

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Attitude determination and disturbance estimation based on adaptive Kalman filter for nano-satellite

Attitude determination and disturbance estimation based on a...

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International Conference on Control, automation and systems

作者： Sung Hyuk Choi Chan Gook Park Department of Mechanical and Aerospace Engineering Seoul National University Seoul 151-742 Republic of Korea Department of Mechanical Engineering Seoul National University / Automation and System Research Institute Seoul 151-742 Republic of Korea

ISBN: (纸本)9781467390583

Nano-satellite has payload limitation to minimize weight and cost then minimum number of attitude sensors can be loaded which are sun sensor, magnetometer and gyroscope. However, The sun sensor cannot be used during eclipse, nano-satellite keeps estimating attitude with model propagator. Which contains the uncertainty, torque disturbance. For small satellite has too low moment of inertia to vulnerable to disturbance relatively. In this reason torque disturbance can be critical point to estimate attitude using propagator. The recursive attitude determination algorithm using Kalman filter is very widely used. For this reasons, attitude determination algorithms based on adaptive extended Kalman filter with disturbance torque are introduced. Which are P-scaling, Q-scaling and Q-estimation technic. In this paper, it is assumed disturbance torque represents the model uncertainty. This research shows it is possible to estimate the disturbance, angular rate and attitude of the satellites through the simulation. To solve the attitude determination problem for nano-satellite, It is possible to estimate not only attitude but also disturbance through the adaptive algorithms.

关键词： Satellite Dynamics Nano-satellite Extended Kalman Filter Space Environment Torque Disturbance Eclipse

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Enhancing BEM simulations of a stalled wind turbine using a 3D correction model

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Journal of Physics: Conference Series 2018年第1期974卷

作者： Galih Bangga Go Hutomo Taurista Syawitri Tri Kusumadewi Winda Oktavia Ahmad Sabila Herlambang Setiadi Muhamad Faisal Yongki Hendranata Dwi Lastomo Louis Putra Stefanus Kristiadi Ilmi Bumi Institute of Aerodynamics and Gas Dynamics University of Stuttgart Stuttgart Germany Mechanical Engineering Department Institut Teknologi Sepuluh Nopember Surabaya Indonesia Toyota SO Department Astra International Ltd. Indonesia Mechanical Engineering Department Universitas Muhammadiyah Surakarta Surakarta Indonesia School of Manufacturing System and Mechanical Engineering Sirindhorn International Institute of Technology Thammasat University Thailand Project Support and Cost Control Division Indoturbine Ltd. Jakarta Indonesia Civil Engineering Department Universitas Brawijaya Malang Indonesia School of Information Technology & Electrical Engineering The University of Queensland Brisbane Australia Non-Installation Top Range Department Berca Schindler Lifts Ltd. Indonesia Graduate Institute of Automation and Control National Taiwan University of Science and Technology Taiwan Mechanical Engineering Department Texas A&M University College Station United States PUI-PT Mechatronics and Industrial Automation Research Center Intitut Teknologi Sepuluh Nopember Surabaya Indonesia Mechanical Engineering Department Politecnico di Milano Milan Italy Aeronautics Department Imperial College of Science Technology and Medicine London United Kingdom Materials Engineering Department Institut Teknologi Sepuluh Nopember Surabaya Indonesia

Nowadays wind turbine rotors are usually employed with pitch control mechanisms to avoid deep stall conditions. Despite that, wind turbines often operate under pitch fault situation causing massive flow separation to occur. Pure Blade Element Momentum (BEM) approaches are not designed for this situation and inaccurate load predictions are already expected. In the present studies, BEM predictions are improved through the inclusion of a stall delay model for a wind turbine rotor operating under pitch fault situation of -2.3° towards stall. The accuracy of the stall delay model is assessed by comparing the results with available Computational Fluid Dynamics (CFD) simulations data.

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面向生物医学临床应用的激光微加工功能表面

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engineering 2018年第6期 172-190页

作者：胡国庆管凯卢立斌张佳茹聂璐管迎春 School of Mechanical Engineering and Automation Beihang University Hefei Innovation Research Institute Beihang University Department of Oncology Center of ExcellenceBOE Hefei Digital Hospital Co.Ltd. Beijing Long March Space Vehicle Research Institute First Academy of the China Aerospace Corporation National Engineering Laboratory of Additive Manufacturing for Large Metallic Components Beihang University

金属医用材料以其高强度、强抗断性、优良的导电性和良好的生物相容性等特点,在医疗器械中日益得到广泛应用。但金属医用材料表面生物性能的不足在很大程度上限制了其进一步的应用。激光微加工是一种增强材料表面性能的先进技术,本文系... 详细信息

金属医用材料以其高强度、强抗断性、优良的导电性和良好的生物相容性等特点,在医疗器械中日益得到广泛应用。但金属医用材料表面生物性能的不足在很大程度上限制了其进一步的应用。激光微加工是一种增强材料表面性能的先进技术,本文系统验证、展示激光微加工医用金属生物材料镁合金和钛合金的可行性,阐述其在细胞黏附和液体活检的应用前景。本文研究激光与材料的相互作用、材料微结构演化和表面性能,分析相关细胞行为和表面增强拉曼散射效应。实验结果表明,细胞在激光微加工表面黏附性能好,并可沿预先设计结构方向生长。此外,激光功能表面可显著增强拉曼信号,增强因子可达6×10～3以上。

关键词：激光微加工功能表面金属合金生物相容性表面增强拉曼散射

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A Survey of Bitmap Index Compression Algorithms for Big Data

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Tsinghua Science and Technology 2015年第1期20卷 100-115页

作者： Zhen Chen Yuhao Wen Junwei Cao Wenxun Zheng Jiahui Chang Yinjun Wu Ge Ma Mourad Hakmaoui Guodong Peng the Research Institute of Information Technology Tsinghua University Tsinghua National Laboratory for Information Science and Technology (TNList) Tsinghua University Department of Electronic Engineering Tsinghua University Department of Physics Tsinghua University Department of Aerospace Engineering Tsinghua University Department of Automation Tsinghua University Department of Computer Science and Technology Tsinghua University Department of Mechanical Engineering Tsinghua University

With the growing popularity of Internet applications and the widespread use of mobile Internet, Internet traffic has maintained rapid growth over the past two decades. Internet Traffic Archival systems（ITAS） for packets or flow records have become more and more widely used in network monitoring, network troubleshooting, and user behavior and experience analysis. Among the three key technologies in ITAS, we focus on bitmap index compression algorithm and give a detailed survey in this paper. The current state-of-the-art bitmap index encoding schemes include： BBC, WAH, PLWAH, EWAH, PWAH, CONCISE, COMPAX, VLC, DF-WAH, and VAL-WAH. Based on differences in segmentation, chunking, merge compress, and Near Identical（NI） features, we provide a thorough categorization of the state-of-the-art bitmap index compression algorithms. We also propose some new bitmap index encoding algorithms, such as SECOMPAX, ICX, MASC, and PLWAH＋, and present the state diagrams for their encoding algorithms. We then evaluate their CPU and GPU implementations with a real Internet trace from CAIDA. Finally, we summarize and discuss the future direction of bitmap index compression algorithms. Beyond the application in network security and network forensic, bitmap index compression with faster bitwise-logical operations and reduced search space is widely used in analysis in genome data, geographical information system, graph databases, image retrieval, Internet of things, etc. It is expected that bitmap index compression will thrive and be prosperous again in Big Data era since 1980s.

关键词： Internet traffic big data traffic archival network security bitmap index bitmap compression algorithm

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