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Increasing Resilience of Production Systems by Dynamic Context Modelling and Process Adaption

Procedia CIRP 2023年 118卷 282-287页

作者： Tim Wunderlich Jonas Hansert Sandro Koch Robert Heinrich Thomas Schlegel Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 09126 Chemnitz Germany Karlsruhe University of Applied Sciences Moltkestr. 30 76133 Karlsruhe Germany Karlsruhe Institute of Technology Am Fasanengarten 5 76131 Karlsruhe Germany Institute of Mechatronic Engineering Technische Universität Dresden 01062 Dresden Germany

The requirements for cyber-physical production systems (CPPS) grow steadily, leading to increased complexity of such systems. To address issues due to reconfiguration or failures, we present an approach to creating a context model of the CPPS components during runtime and to detect deviations from the planned production processes. Furthermore, we present a concept for modelling production processes that allows for dynamic process adaption during runtime. We then utilize this process adaption and the context model to cope with unforeseen failures and increase the resilience of the system. Finally, we evaluate the feasibility of our approach by applying it to an Industry 4.0 production system.

关键词： resilience cyber-physical production systems process adaption context awareness

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Nonlinearity of balanced mems loudspeakers: Optical experiments and numerical modeling using time-harmonic signals 27

Nonlinearity of balanced mems loudspeakers: Optical experime...

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27th International Congress on Sound and Vibration, ICSV 2021

作者： Melnikov, Anton Michael, Stolz Wall, Franziska Kaiser, Bert Mrosk, Andreas Schuffenhauer, David Monsalve, Jorge Sergiu, Langa Schenk, Hermann A.G. Ehrig, Lutz Conrad, Holger Ahnert, Maik Schenk, Harald Fraunhofer Institute for Photonic Microsystems IPMS Dresden Germany Arioso Systems GmbH Dresden Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden Germany Brandenburg Technical University Cottbus-Senftenberg BTU Micro and Nano Systems Cottbus Germany

ISBN: (纸本)9788378807995

A recently introduced novel actuator class, called the nano electrostatic drive (NED), uses the electrostatic actuation to generate large deflections of elastic structures. The NED principle was recently successfully applied to create an all silicon loudspeaker based on micro-electro-mechanical systems (MEMS) technology. Such MEMS audio transducers cover the full frequency range required for high fidelity audio applications. High fidelity audio reproduction also demands minimizing harmonic distortions substantially below 1 %. A major advance in this direction is combining the NED principle with a push-pull driving scheme in a balanced design (BNED), eliminating even harmonics. The practical implementation of a BNED design is however demanding. The nature of the Coulomb force, the impact of stress stiffening and the large deformations required for generating high sound pressures, to name a few aspects, potentially contribute to the harmonic distortion and therefore need advanced experimental methods and simulation models to allow for an apt design. In this paper, we report first results of an experimental technique, combining an optical microscope with a high-speed camera, capable of analyzing the local details of the actuator movement at frame rates of 50,000 frames per second. Dynamic features, such as the excitation of harmonics and intermodulations become clearly visible. These experimental results are then used to scrutinize and refine our multi physics FEM simulations. © "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021. All rights reserved.

关键词： Loudspeakers

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Laser structuring with DLIP technology of tungsten carbide with different binder content 12

Laser structuring with DLIP technology of tungsten carbide w...

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12th CIRP Conference on Photonic Technologies, LANE 2022

作者： Teicher, Uwe Baumann, Robert Bouraoui, Yasmine Achour, Anas Ben Lasagni, Andrés Fabián Ihlenfeldt, Steffen Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany Institute for Manufacturing Technology Technische Universität Dresden George-Baehr-Str. 3c Dresden01069 Germany Fraunhofer Institute for Material and Beam Technology IWS Winterbergstraße 28 Dresden01277 Germany Institute of Mechatronic Engineering Technische Universität Dresden Helmholtzstraße 7a Dresden01069 Germany

In machining, tool wear is one of the main influence factors for the resulting quality of the product. Several wear mechanisms have to be addressed to prevent unwanted deterioration of the tool integrity. For aluminium alloys, adhesion of the workpiece material on the cutting tool is one of the most challenging wear mechanisms. Engineering surface microtopographies has been proved as a convenient strategy to tackle this issue. Particularly, the direct laser interference patterning (DLIP) technique enables the integration of periodic structures on the micrometer or sub-micrometer scale. In this study the structuring of tungsten carbide with different cobalt content is presented. The interference of two laser beams leads to periodic line-like structures with a spatial period of 5.5 µm. A maximum structure depth of 2.2 µm is reached by controlling the processing parameters. Moreover, the wettability of the structured samples was analyzed by contact angle measurements with selected cooling lubricants, revealing a hydrophilic behavior with a decreased contact angle of 10°. This work gives an insight into the possibilities of structuring tungsten carbide materials with a picosecond laser source in combination with an innovative beam shaping setup from the point of view of an analysis to explore the formation of structured surfaces and their wetting behavior with cooling lubricants. © 2022 The Authors. Published by Elsevier B.V.

关键词： Tungsten carbide

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A CAD-based workflow and mechanical characterization for additive manufacturing of tailored lattice structures 29

A CAD-based workflow and mechanical characterization for add...

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29th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2018

作者： Koch, P. Korn, H. Kordass, R. Holtzhausen, S. Schoene, C. Mueller, B. Stelzer, R. Institute of Machine Elements and Machine Design TU Dresden Dresden Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden Germany

Lattice structures are highly recommended for lightweight applications and cost reduction in additive manufacturing (AM). Currently, parts with lattice structures are still mainly used for illustrative purposes and rarely in industrial products. One important reason is that, due to their high dependency on macro- and micro-geometry, the mechanical properties of manufactured structures are difficult to predict. Thus, even and precise struts are needed. In this paper, a workflow for fabrication of lattice structures with strut-diameters from 150 µm to 400 µm on commercial laser beam melting (LBM) systems is presented. Based on a CAD-integrated user-interface for lattice design, a customized slicing algorithm determines database-aided suitable exposure parameters which ensure that the properties of the manufactured struts will just be as specified upon design. Subsequently, compression tests are performed in order to verify the established workflow. The developed tool enables designers to integrate AM-specific geometries into their components with little specific experience in AM. © Solid Freeform Fabrication 2018: Proceedings of the 29th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2018. All Rights Reserved.

关键词： 3D printers

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A survey on modeling and forecasting the energy consumption in discrete manufacturing 27

A survey on modeling and forecasting the energy consumption ...

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27th CIRP Life Cycle Engineering Conference, LCE 2020

作者： Reinhardt, Heiner Bergmann, Jan-Peter Münnich, Marc Rein, David Putz, Matthias Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany

The manufacturing industry faces environmental challenges due to its high electrical energy demand. Measures for improving the energy efficiency of manufacturing processes are applied to reduce the total energy consumption while eco-friendly renewable energy sources are harnessed increasingly. However, the volatile nature of renewables drives a change in energy allocation and the electrical grid. Both energy efficiency and energy allocation may benefit from accurate energy consumption modeling and forecasting. In this paper we constitute the state of the art of existing modeling techniques in the domain of discrete manufacturing and derive future research activities. © 2020 The Author(s). Published by Elsevier B.V.

关键词： Energy efficiency

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Temporal analysis of event-discrete alarm data for improved manufacturing 53

Temporal analysis of event-discrete alarm data for improved ...

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53rd CIRP Conference on Manufacturing Systems, CMS 2020

作者： Reinhardt, Heiner Bergmann, Jan-Peter Stoll, Anke Putz, Matthias Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany

Efficient response to machine failures is crucial for improving machine availability. In practice, the number of alarms occurring during the operation of manufacturing systems could overwhelm even experienced machine operators. Manufacturing execution systems (MES) therefore often allow for alarm data acquisition as well as its filtering and aggregation to reduce the occurring information overload. However, manual configuration of these systems may be cumbersome and time-consuming. Hence, we propose an event-discrete method for temporal alarm data analysis to support the configuration process. © 2020 The Authors.

关键词： Knowledge management

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A novel approach for increasing the traceability of 3D printed medical products

A novel approach for increasing the traceability of 3D print...

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作者： Matvieieva, Nataliia Neupetsch, Constanze Oettel, Markus Makdani, Varun Drossel, Welf- Guntram Fraunhofer Institute for Machine Tools and Forming Technology Iwu Nöthnitzer Straße 44 Dresden Germany

According to the European Medical Device Directive (MDR (EU) 2017/745), medical products of all risk classes are obliged to be labelled with Unique Device Identification Codes (UDI). In order to meet the requirements of the MDR, a novel method of identification for additively manufactured metallic products was developed at the fraunhofer institute for machine tools and forming technology (iwu). The method provides a product traceability within its production process and during the whole product lifespan, and also functions as a counterfeit protection. This paper shows the integration of a unique identification during an additive manufacturing process for a titanium part. The readout of the integrated identification was executed using ultrasonic and eddy current methods, as well as micro computed tomography. Obtained results are discussed in the paper. © 2020 by Walter de Gruyter Berlin/Boston 2020.

关键词： Laser beams

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Robust entropy search for safe efficient Bayesian optimization 24

Robust entropy search for safe efficient Bayesian optimizati...

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Proceedings of the Fortieth Conference on Uncertainty in Artificial Intelligence

作者： Dorina Weichert Alexander Kister Sebastian Houben Patrick Link Gunar Ernis Fraunhofer Institute for Intelligent Analysis and Information Systems IAIS Sankt Augustin Germany VP.1 eScience Federal Institute for Materials Research and Testing BAM Berlin Germany University of Applied Sciences Bonn-Rhein-Sieg Sankt Augustin Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany and Institute of Mechatronic Engineering TUD Dresden University of Technology Dresden Germany

The practical use of Bayesian Optimization (BO) in engineering applications imposes special requirements: high sampling efficiency on the one hand and finding a robust solution on the other hand. We address the case of adversarial robustness, where all parameters are controllable during the optimization process, but a subset of them is uncontrollable or even adversely perturbed at the time of application. To this end, we develop an efficient information-based acquisition function that we call Robust Entropy Search (RES). We empirically demonstrate its benefits in experiments on synthetic and real-life data. The results show that RES reliably finds robust optima, outperforming state-of-the-art algorithms.

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Enhancing cooling tower performance with condition monitoring and machine learning based drift detection

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Procedia CIRP 2022年 112卷 146-150页

作者： Sina Nahvi Stefan Polster Sebastian Melzer Anke Stoll Marc Münnich Stefan Mannstadt Philipp Klimant Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany Multi Kühlsysteme GmbH Zschorlauer Straße 56 08280 Aue Germany

Process cooling is crucial to many manufacturing processes. To monitor the performance of a cooling tower, it was equipped with extensive sensors for internal and environmental data acquisition. The aim is to improve reactive and predictive maintenance by estimating the actual condition as well as predicting defective behavior of the cooling tower. We designed a method, which derives the degree of defect from data of the non-defective cooling tower. A concept drift detection approach was implemented, which monitors the model estimation error of a multilayer perceptron model. Increasing model estimation error indicates changing system behavior and increasing risk of failure.

关键词： Condition monitoring Fault detection Neural Network Concept drift Cooling Tower

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Study on flushing condition for improving silver deposition in silver nano-powder mixed EDM 22

Study on flushing condition for improving silver deposition ...

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22nd International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2022

作者： Bui, Viet D. Meinshausen, Ann-Kathrin Berger, Thomas Martin, André Harnisch, Karsten Bertrand, Jessica Schubert, Andreas Chemnitz University of Technology Institute for Machine Tools and Production Processes Professorship Micromanufacturing Technology Reichenhainer Str. 70 Chemnitz09126 Germany Otto-von-Guericke University Magdeburg Department of Orthopaedic Surgery Leipziger Str. 44 Magdeburg39120 Germany Fraunhofer Institute for Machine Tools and Forming Technology Reichenhainer Str. 88 Chemnitz09126 Germany

ISBN: (纸本)9781998999118

Silver nano-powder mixed electrical discharge machining (PMEDM) has demonstrated its applicability for antibacterial surface modification. However, previous PMEDM studies indicated that jet flushing leads to a low powder concentration in the spark gap, which was the main reason for a low deposited silver content. Internal flushing with different dielectric pressures was therefore proposed and will be investigated in this study. To do so, Ti-6Al-4V hollow tool electrodes with an outer diameter of 3 mm and an inner diameter of 2.5 mm are selected to machine Ti-6Al-4V samples. Silver nano-powders with a size of 50 nm to 60 nm are suspended in the hydrocarbon-based dielectric fluid at a 5 g/l powder concentration. Surface roughness and resulting silver content and distribution on the modified surface are analysed and discussed. Results show that internal flushing significantly increases the deposited silver content when high pressure of the dielectric fluid was applied. In addition, with careful control, the internal flushing is a promising strategy for improving the uniformity of the deposited silver distribution. © European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 22nd International Conference and Exhibition, EUSPEN 2022. All rights reserved.

关键词： Surface roughness

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