@article{KunkelGebhardtMpofuetal.2019, author = {Kunkel, Maximilian Hugo and Gebhardt, Andreas and Mpofu, Khumbulani and Kallweit, Stephan}, title = {Quality assurance in metal powder bed fusion via deep-learning-based image classification}, series = {Rapid Prototyping Journal}, volume = {26}, journal = {Rapid Prototyping Journal}, number = {2}, issn = {1355-2546}, doi = {10.1108/RPJ-03-2019-0066}, pages = {259 -- 266}, year = {2019}, language = {en} } @article{RaffeisAdjeiKyeremehVroomenetal.2020, author = {Raffeis, Iris and Adjei-Kyeremeh, Frank and Vroomen, Uwe and Westhoff, Elmar and Bremen, Sebastian and Hohoi, Alexandru and B{\"u}hrig-Polaczek, Andreas}, title = {Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {Art. 3401}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app10103401}, pages = {1 -- 15}, year = {2020}, abstract = {As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni-Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8\% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s-1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20\% to 31\% (V), as well as from 16\% to 25\% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced.}, language = {en} } @inproceedings{BraunChengDoweyetal.2020, author = {Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Survey on Security Concepts to Adapt Flexible Manufacturing and Operations Management based upon Multi-Agent Systems}, series = {2020 IEEE 29th International Symposium on Industrial Electronics (ISIE)}, booktitle = {2020 IEEE 29th International Symposium on Industrial Electronics (ISIE)}, doi = {10.1109/ISIE45063.2020.9152210}, year = {2020}, language = {en} } @article{FrankoDuKallweitetal.2020, author = {Franko, Josef and Du, Shengzhi and Kallweit, Stephan and Duelberg, Enno Sebastian and Engemann, Heiko}, title = {Design of a Multi-Robot System for Wind Turbine Maintenance}, series = {Energies}, volume = {13}, journal = {Energies}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en13102552}, pages = {Article 2552}, year = {2020}, abstract = {The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to the large scale of wind turbines. Technical climbers are required to work at significant heights, even in bad weather conditions. Furthermore, a skilled labor force with sufficient knowledge in repairing fiber composite material is rare. Autonomous mobile systems enable the digitization of the maintenance process. They can be designed for weather-independent operations. This work contributes to the development and experimental validation of a maintenance system consisting of multiple robotic platforms for a variety of tasks, such as wind turbine tower and rotor blade service. In this work, multicopters with vision and LiDAR sensors for global inspection are used to guide slower climbing robots. Light-weight magnetic climbers with surface contact were used to analyze structure parts with non-destructive inspection methods and to locally repair smaller defects. Localization was enabled by adapting odometry for conical-shaped surfaces considering additional navigation sensors. Magnets were suitable for steel towers to clamp onto the surface. A friction-based climbing ring robot (SMART— Scanning, Monitoring, Analyzing, Repair and Transportation) completed the set-up for higher payload. The maintenance period could be extended by using weather-proofed maintenance robots. The multi-robot-system was running the Robot Operating System (ROS). Additionally, first steps towards machine learning would enable maintenance staff to use pattern classification for fault diagnosis in order to operate safely from the ground in the future.}, language = {en} } @article{CosmaKesslerGebhardtetal.2020, author = {Cosma, Cosmin and Kessler, Julia and Gebhardt, Andreas and Campbell, Ian and Balc, Nicolae}, title = {Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed}, series = {Materials}, volume = {13}, journal = {Materials}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma13040905}, pages = {1 -- 18}, year = {2020}, abstract = {To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 μm and just 10\% of them hold a diameter less than 21.18 μm. SLM parameters under consideration include laser power up to 200 W, 250-1500 mm/s scanning speed, 80 μm hatch spacing, 35 μm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20\% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L.}, language = {en} } @inproceedings{BraunChengLaietal.2019, author = {Braun, Sebastian and Cheng, Chi-Tsun and Lai, Chow Yin and Wollert, J{\"o}rg}, title = {Microservice Architecture for Automation - Realization by the example of a model-factory's manufacturing execution system}, series = {Proceedings of the 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, booktitle = {Proceedings of the 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, pages = {33 -- 37}, year = {2019}, language = {en} } @inproceedings{GerhardsSchleserOtten2019, author = {Gerhards, Benjamin and Schleser, Markus and Otten, Christian}, title = {Advancements of mobile vacuum laser welding for industrial thick sheet applications}, series = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, booktitle = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, pages = {1 -- 8}, year = {2019}, language = {en} } @inproceedings{GerhardsSchleserOttenetal.2019, author = {Gerhards, Benjamin and Schleser, Markus and Otten,, Christian and Schwarz, Alexander and Gebhardt, Andreas}, title = {Innovative Laser Beam Joining Technology for Additive Manufactured Parts}, series = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, booktitle = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, pages = {1 -- 8}, year = {2019}, language = {en} } @inproceedings{EichlerSkupinThurnetal.2019, author = {Eichler, Fabian and Skupin, Marco and Thurn, Laura and Kasch, Susanne and Schmidt, Thomas}, title = {Operating limits for beam melting of glass materials}, series = {Modern Technologies in Manufacturing (MTeM 2019)}, volume = {299}, booktitle = {Modern Technologies in Manufacturing (MTeM 2019)}, number = {Article 01004}, doi = {10.1051/matecconf/201929901004}, pages = {8 Seiten}, year = {2019}, abstract = {Laser-based Additive Manufacturing (AM) processes for the use of metals out of the powder bed have been investigated profusely and are prevalent in industry. Although there is a broad field of application, Laser Powder Bed Fusion (LPBF), also known as Selective Laser Melting (SLM) of glass is not fully developed yet. The material properties of glass are significantly different from the investigated metallic material for LPBF so far. As such, the process cannot be transferred, and the parameter limits and the process sequence must be redefined for glass. Starting with the characterization of glass powders, a parameter field is initially confined to investigate the process parameter of different glass powder using LPBFprocess. A feasibility study is carried out to process borosilicate glass powder. The effects of process parameters on the dimensional accuracy of fabricated parts out of borosilicate and hints for the post-processing are analysed and presented in this paper.}, language = {en} } @inproceedings{AbbasThurnKessleretal.2019, author = {Abbas, Karim and Thurn, Laura and Kessler, Julia and Eichler, Fabian}, title = {Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads}, series = {Modern technologies in manufacturing (MTeM 2019)}, volume = {299}, booktitle = {Modern technologies in manufacturing (MTeM 2019)}, number = {Article 01009}, doi = {10.1051/matecconf/201929901009}, pages = {8 Seiten}, year = {2019}, language = {en} } @inproceedings{LuftGebhardtBalc2019, author = {Luft, Angela and Gebhardt, Andreas and Balc, Nicolae}, title = {Challenges of additive manufacturing in production systems}, series = {Modern technologies in manufacturing (MTeM 2019)}, volume = {299}, booktitle = {Modern technologies in manufacturing (MTeM 2019)}, number = {Article 01003}, doi = {10.1051/matecconf/201929901003}, pages = {6 Seiten}, year = {2019}, language = {en} } @article{PancContiuBocanetetal.2019, author = {Panc, Nicolae and Contiu, Glad and Bocanet, Vlad and Thurn, Laura and Sabau, Emilia}, title = {The influence of cutting technology on surface wear hardness}, series = {Academic Journal of Manufacturing Engineering}, volume = {17}, journal = {Academic Journal of Manufacturing Engineering}, number = {3}, issn = {1583-7904}, pages = {205 -- 210}, year = {2019}, language = {en} } @inproceedings{UlmerBraunLaietal.2019, author = {Ulmer, Jessica and Braun, Sebastian and Lai, Chow Yin and Cheng, Chi-Tsun and Wollert, J{\"o}rg}, title = {Generic integration of VR and AR in product lifecycles based on CAD models}, series = {Proceedings of The 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, booktitle = {Proceedings of The 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, year = {2019}, language = {en} } @article{BucurLazarescuPopetal.2019, author = {Bucur, Alexandru and Lazarescu, Lucian and Pop, Grigore Marian and Achimas, Gheorghe and Gebhardt, Andreas}, title = {Tribological performance of biodegradable lubricants under different surface roughness of tools}, series = {Academic Journal of Manufacturing Engineering}, volume = {17}, journal = {Academic Journal of Manufacturing Engineering}, number = {1}, issn = {1583-7904}, pages = {172 -- 178}, year = {2019}, language = {en} } @article{SchwarzGebhardtSchleseretal.2019, author = {Schwarz, Alexander and Gebhardt, Andreas and Schleser, Markus and Popoola, Patricia}, title = {New Welding Joint Geometries Manufactured by Powder Bed Fusion from 316L}, series = {Materials Performance and Characterization 8}, journal = {Materials Performance and Characterization 8}, number = {in press}, issn = {2379-1365}, doi = {10.1520/MPC20180096}, year = {2019}, language = {en} } @inproceedings{EngemannBadriWenningetal.2019, author = {Engemann, Heiko and Badri, Sriram and Wenning, Marius and Kallweit, Stephan}, title = {Implementation of an Autonomous Tool Trolley in a Production Line}, series = {Advances in Service and Industrial Robotics. RAAD 2019. Advances in Intelligent Systems and Computing, vol 980}, booktitle = {Advances in Service and Industrial Robotics. RAAD 2019. Advances in Intelligent Systems and Computing, vol 980}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-19648-6}, doi = {10.1007/978-3-030-19648-6_14}, pages = {117 -- 125}, year = {2019}, language = {en} } @inproceedings{RieperGebhardtStucker2016, author = {Rieper, Harald and Gebhardt, Andreas and Stucker, Brent}, title = {Process parameters for Selective Laser Melting of AgCu7}, series = {DDMC, Fraunhofer Direct Digital Manufacturing Conference, 3}, booktitle = {DDMC, Fraunhofer Direct Digital Manufacturing Conference, 3}, publisher = {Fraunhofer-Verlag}, address = {Stuttgart}, isbn = {978-3-8396-1001-5}, pages = {171 -- 176}, year = {2016}, language = {en} } @incollection{FranzenSteckenPfaffetal.2019, author = {Franzen, Julian and Stecken, Jannis and Pfaff, Raphael and Kuhlenk{\"o}tter, Bernd}, title = {Using the Digital Shadow for a Prescriptive Optimization of Maintenance and Operation : The Locomotive in the Context of the Cyber-Physical System}, series = {Advances in Production, Logistics and Traffic}, booktitle = {Advances in Production, Logistics and Traffic}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-13535-5}, doi = {10.1007/978-3-030-13535-5_19}, pages = {265 -- 276}, year = {2019}, abstract = {In competition with other modes of transport, rail freight transport is looking for solutions to become more attractive. Short-term success can be achieved through the data-driven optimization of operations and maintenance as well as the application of novel strategies such as prescriptive maintenance. After introducing the concept of prescriptive maintenance, this paper aims to prove that vehicle-focused applications of this approach indeed have the potential to increase attractiveness. However, even greater advantages can be activated if data from the horizontal network of the vehicle is available. Drawing on the state of the art in research and technology in the field of cyber-physical systems (CPS) as well as digital twins and shadows, our work serves to design a system of systems for the horizontal interconnection of a rail vehicle and to conceptualize a draft for a digital twin of a locomotive.}, language = {en} } @inproceedings{WiesenEngemannLimpertetal.2018, author = {Wiesen, Patrick and Engemann, Heiko and Limpert, Nicolas and Kallweit, Stephan}, title = {Learning by Doing - Mobile Robotics in the FH Aachen ROS Summer School}, series = {European Robotics Forum 2018, TRROS18 Workshop}, booktitle = {European Robotics Forum 2018, TRROS18 Workshop}, pages = {47 -- 58}, year = {2018}, language = {en} } @inproceedings{PfaffMelcherFranzen2018, author = {Pfaff, Raphael and Melcher, Karin and Franzen, Julian}, title = {Rare event simulation to optimise maintenance intervals of safety critical redundant subsystems}, series = {Proceedings of the European Conference of the PHM Society}, volume = {4}, booktitle = {Proceedings of the European Conference of the PHM Society}, number = {1}, pages = {1 -- 6}, year = {2018}, language = {en} } @article{FranzenPindersPfaffetal.2018, author = {Franzen, Julius and Pinders, Erik and Pfaff, Raphael and Enning, Manfred}, title = {RailCrowd's virtual fleets: Make most of your asset data}, series = {Deine Bahn}, journal = {Deine Bahn}, number = {9}, publisher = {Bahn-Fachverlag}, address = {Berlin}, issn = {0948-7263}, pages = {11 -- 13}, year = {2018}, abstract = {For smaller railway operators or those with a diverse fleet, it can be difficult to collect sufficient data to improve maintenance programs. At the same time, new rules such as entity in charge of maintenance - ECM - regulations impose an additional workload by requiring a dedicated maintenance management system and specific reports. The RailCrowd platform sets out to facilitate compliance with ECM and similar regulations while at the same time pooling anonymised fleet data across operators to form virtual fleets, providing greater data insights.}, language = {en} } @inproceedings{GaoBabilonPfaffetal.2018, author = {Gao, H. and Babilon, Katharina and Pfaff, Raphael and Gan, F. and Reich, A.}, title = {Model of wheel-rail contact for sanding and adhesion enhancement}, series = {Proceedings of the 11th International Conference on Contact Mechanics and Wear of Rail/wheel Systems, CM 2018}, booktitle = {Proceedings of the 11th International Conference on Contact Mechanics and Wear of Rail/wheel Systems, CM 2018}, isbn = {978-946186963-0}, pages = {314 -- 321}, year = {2018}, language = {en} } @inproceedings{BueckingPfaffDirksmeier2018, author = {B{\"u}cking, Henrik and Pfaff, Raphael and Dirksmeier, Roger}, title = {Sensor positioning and thermal model for condition monitoring of pressure gas reservoirs in vehicles}, series = {Proceedings of the Fourth European Conference of the Prognostics and Health Management Society, Utrecht, Netherlands, 2018}, booktitle = {Proceedings of the Fourth European Conference of the Prognostics and Health Management Society, Utrecht, Netherlands, 2018}, pages = {5 Seiten}, year = {2018}, language = {en} } @inproceedings{ThurnGebhardt2018, author = {Thurn, Laura and Gebhardt, Andreas}, title = {Strategy of Education on Materials for Students}, series = {Conference Proceedings: „New Perspectives in Science Education"}, booktitle = {Conference Proceedings: „New Perspectives in Science Education"}, address = {Florence, Italy}, isbn = {978-88-6292-976-9}, pages = {156 -- 161}, year = {2018}, language = {en} } @book{GebhardtKesslerThurn2019, author = {Gebhardt, Andreas and Kessler, Julia and Thurn, Laura}, title = {3D printing : understanding additive manufacturing}, edition = {2. Auflage}, publisher = {Hanser}, address = {M{\"u}nchen}, isbn = {978-1-56990-702-3}, pages = {XVI, 204 Seiten}, year = {2019}, language = {en} } @inproceedings{FateriGebhardtRenftle2015, author = {Fateri, Miranda and Gebhardt, Andreas and Renftle, Georg}, title = {Additive manufacturing of drainage segments for cooling system of crucible melting furnaces}, series = {Advanced Processing and Manufacturing Technologies for Structural and Multifunctional Materials II, International Symposium on Advanced Processing and Manufacturing Technologies for Structural and Multifunctional Materials, ICACC 15, 39th International Conference on Advanced Ceramics and Composites, Daytona Beach, FL, US, Jan 25-30, 2015}, booktitle = {Advanced Processing and Manufacturing Technologies for Structural and Multifunctional Materials II, International Symposium on Advanced Processing and Manufacturing Technologies for Structural and Multifunctional Materials, ICACC 15, 39th International Conference on Advanced Ceramics and Composites, Daytona Beach, FL, US, Jan 25-30, 2015}, publisher = {Wiley}, address = {Hoboken}, issn = {0196-6219}, doi = {10.1002/9781119211662.ch14}, pages = {123 -- 131}, year = {2015}, language = {en} } @inproceedings{FerreinSchifferKallweit2018, author = {Ferrein, Alexander and Schiffer, Stefan and Kallweit, Stephan}, title = {The ROSIN Education Concept - Fostering ROS Industrial-Related Robotics Education in Europe}, series = {ROBOT 2017: Third Iberian Robotics Conference}, booktitle = {ROBOT 2017: Third Iberian Robotics Conference}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-70836-2}, doi = {10.1007/978-3-319-70836-2_31}, pages = {370 -- 381}, year = {2018}, language = {en} } @article{MichauxMatternKallweit2018, author = {Michaux, F. and Mattern, P. and Kallweit, Stephan}, title = {RoboPIV: how robotics enable PIV on a large industrial scale}, series = {Measurement Science and Technology}, volume = {29}, journal = {Measurement Science and Technology}, number = {7}, publisher = {IOP}, address = {Bristol}, issn = {1361-6501}, doi = {10.1088/1361-6501/aab5c1}, pages = {074009}, year = {2018}, abstract = {This work demonstrates how the interaction between particle image velocimetry (PIV) and robotics can massively increase measurement efficiency. The interdisciplinary approach is shown using the complex example of an automated, large scale, industrial environment: a typical automotive wind tunnel application. Both the high degree of flexibility in choosing the measurement region and the complete automation of stereo PIV measurements are presented. The setup consists of a combination of three robots, individually used as a 6D traversing unit for the laser illumination system as well as for each of the two cameras. Synchronised movements in the same reference frame are realised through a master-slave setup with a single interface to the user. By integrating the interface into the standard wind tunnel management system, a single measurement plane or a predefined sequence of several planes can be requested through a single trigger event, providing the resulting vector fields within minutes. In this paper, a brief overview on the demands of large scale industrial PIV and the existing solutions is given. Afterwards, the concept of RoboPIV is introduced as a new approach. In a first step, the usability of a selection of commercially available robot arms is analysed. The challenges of pose uncertainty and importance of absolute accuracy are demonstrated through comparative measurements, explaining the individual pros and cons of the analysed systems. Subsequently, the advantage of integrating RoboPIV directly into the existing wind tunnel management system is shown on basis of a typical measurement sequence. In a final step, a practical measurement procedure, including post-processing, is given by using real data and results. Ultimately, the benefits of high automation are demonstrated, leading to a drastic reduction in necessary measurement time compared to non-automated systems, thus massively increasing the efficiency of PIV measurements.}, language = {en} } @article{KunkelGebhardtMpofuetal.2018, author = {Kunkel, Maximilian Hugo and Gebhardt, Andreas and Mpofu, Khumbaulani and Kallweit, Stephan}, title = {Statistical assessment of mechanical properties of selective laser melted specimens of stainless steel}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {98}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {5-8}, publisher = {Springer}, address = {London}, issn = {0268-3768}, doi = {10.1007/s00170-018-2040-8}, pages = {1409 -- 1431}, year = {2018}, abstract = {The rail business is challenged by long product life cycles and a broad spectrum of assembly groups and single parts. When spare part obsolescence occurs, quick solutions are needed. A reproduction of obsolete parts is often connected to long waiting times and minimum lot quantities that need to be purchased and stored. Spare part storage is therefore challenged by growing stocks, bound capital and issues of part ageing. A possible solution could be a virtual storage of spare parts which will be 3D printed through additive manufacturing technologies in case of sudden demand. As mechanical properties of additive manufactured parts are neither guaranteed by machine manufacturers nor by service providers, the utilization of this relatively young technology is impeded and research is required to address these issues. This paper presents an examination of mechanical properties of specimens manufactured from stainless steel through the selective laser melting (SLM) process. The specimens were produced in multiple batches. This paper interrogates the question if the test results follow a normal distribution pattern and if mechanical property predictions can be made. The results will be put opposite existing threshold values provided as the industrial standard. Furthermore, probability predictions will be made in order to examine the potential of the SLM process to maintain state-of-the-art mechanical property requirements.}, language = {en} } @inproceedings{SchleupenEngemannBagherietal.2016, author = {Schleupen, Josef and Engemann, Heiko and Bagheri, Mohsen and Kallweit, Stephan}, title = {The potential of SMART climbing robot combined with a weatherproof cabin for rotor blade maintenance}, series = {17th European Conference on Composite Materials - ECCM, Munich, Germany}, booktitle = {17th European Conference on Composite Materials - ECCM, Munich, Germany}, pages = {1 -- 8}, year = {2016}, language = {en} } @inproceedings{KleineKallweitMichauxetal.2016, author = {Kleine, Harald and Kallweit, Stephan and Michaux, Frank and Havermann, Marc and Olivier, Herbert}, title = {PIV Measurement of Shock Wave Diffraction}, series = {18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon}, booktitle = {18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon}, pages = {1 -- 14}, year = {2016}, language = {en} } @inproceedings{ThurnBalcGebhardtetal.2017, author = {Thurn, Laura and Balc, Nicolae and Gebhardt, Andreas and Kessler, Julia}, title = {Education packed in technology to promote innovations: Teaching Additive Manufacturing based on a rolling Lab}, series = {Modern Technologies in Manufacturing (MTeM 2017 - AMaTUC)}, booktitle = {Modern Technologies in Manufacturing (MTeM 2017 - AMaTUC)}, issn = {2261-236X}, doi = {10.1051/matecconf/201713702013}, pages = {6 Seiten}, year = {2017}, language = {en} } @inproceedings{Pfaff2017, author = {Pfaff, Raphael}, title = {Analysis of Big Data Streams to obtain Braking Reliability Information for Train Protection systems}, series = {Asia-Pacific Conference of the Prognostics and Health Management Society}, booktitle = {Asia-Pacific Conference of the Prognostics and Health Management Society}, pages = {1 -- 7}, year = {2017}, language = {en} } @inproceedings{PfaffShahidiEnning2017, author = {Pfaff, Raphael and Shahidi, Parham and Enning, Manfred}, title = {Connected freight rail rolling stock: a modular approach integrating sensors, actors and cyber physical systems for operational advantages and condition based maintenance}, series = {Asia-Pacific Conference of the Prognostics and Health Management Society}, booktitle = {Asia-Pacific Conference of the Prognostics and Health Management Society}, pages = {1 -- 7}, year = {2017}, language = {en} } @inproceedings{ShahidiPfaffEnning2017, author = {Shahidi, Parham and Pfaff, Raphael and Enning, Manfred}, title = {The connected wagon - a concept for the integration of vehicle side sensors and actors with cyber physical representation for condition based maintenance}, series = {First International Conference on Rail Transportation}, booktitle = {First International Conference on Rail Transportation}, pages = {1 -- 8}, year = {2017}, language = {en} } @inproceedings{PfaffMoshiriReichetal.2017, author = {Pfaff, Raphael and Moshiri, Amir and Reich, Alexander and G{\"a}bel, Markus}, title = {Modelling of the effect of sanding on the wheel-rail adhesion area}, series = {First International Conference on Rail Transportation}, booktitle = {First International Conference on Rail Transportation}, pages = {1 -- 7}, year = {2017}, language = {en} } @inproceedings{PfaffSchmidtEnning2017, author = {Pfaff, Raphael and Schmidt, B. D. and Enning, Manfred}, title = {Towards inclusion of the freight rail system in the industrial internet of things - Wagon 4.0}, series = {Stephenson Conference, London, March 2017}, booktitle = {Stephenson Conference, London, March 2017}, pages = {1 -- 10}, year = {2017}, language = {en} } @inproceedings{EngemannWiesenKallweitetal.2018, author = {Engemann, Heiko and Wiesen, Patrick and Kallweit, Stephan and Deshpande, Harshavardhan and Schleupen, Josef}, title = {Autonomous mobile manipulation using ROS}, series = {Advances in Service and Industrial Robotics}, booktitle = {Advances in Service and Industrial Robotics}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-61276-8}, doi = {10.1007/978-3-319-61276-8_43}, pages = {389 -- 401}, year = {2018}, language = {en} } @inproceedings{ThurnGebhardt2017, author = {Thurn, Laura and Gebhardt, Andreas}, title = {Arousing Enthusiasm for STEM: Teaching 3D Printing Technology}, series = {Conference Proceedings: New Perspectives in Science Education}, booktitle = {Conference Proceedings: New Perspectives in Science Education}, publisher = {liberiauniversitaria.it}, address = {Padua}, isbn = {978-88-6292-847-2}, pages = {87 -- 92}, year = {2017}, language = {en} } @inproceedings{KesslerBalcGebhardtetal.2017, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas and Abbas, Karim}, title = {Basic research on lattice structures focused on the reliance of the cross sectional area and additional coatings}, series = {The 4th International Conference on Computing and Solutions in Manufacturing Engineering 2016 - CoSME'16}, booktitle = {The 4th International Conference on Computing and Solutions in Manufacturing Engineering 2016 - CoSME'16}, edition = {Vol. 94}, doi = {10.1051/matecconf/20179403008}, pages = {7 S.}, year = {2017}, language = {en} } @inproceedings{SchleupenEngemannBagherietal.2017, author = {Schleupen, Josef and Engemann, Heiko and Bagheri, Mohsen and Kallweit, Stephan and Dahmann, Peter}, title = {Developing a climbing maintenance robot for tower and rotor blade service of wind turbines}, series = {Advances in Robot Design and Intelligent Control : Proceedings of the 25th Conference on Robotics in Alpe-Adria-Danube Region (RAAD16)}, booktitle = {Advances in Robot Design and Intelligent Control : Proceedings of the 25th Conference on Robotics in Alpe-Adria-Danube Region (RAAD16)}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-49058-8}, doi = {10.1007/978-3-319-49058-8_34}, pages = {310 -- 319}, year = {2017}, language = {en} } @inproceedings{KesslerBalcGebhardt2016, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas}, title = {Basic research on lattice structures focused on the strut shape and welding beads}, series = {Physics Procedia}, volume = {Vol. 83}, booktitle = {Physics Procedia}, issn = {1875-3884}, doi = {10.1016/j.phpro.2016.08.086}, pages = {833 -- 838}, year = {2016}, language = {en} } @article{KilicRaatschenKoerfgenetal.2017, author = {Kilic, S. A. and Raatschen, Hans-J{\"u}rgen and K{\"o}rfgen, B. and Apaydin, N. M. and Astaneh-Asl, A.}, title = {FE Model of the Fatih Sultan Mehmet Suspension Bridge Using Thin Shell Finite Elements}, series = {Arabian Journal for Science and Engineering}, volume = {42}, journal = {Arabian Journal for Science and Engineering}, number = {3}, publisher = {Springer Nature}, issn = {2191-4281}, doi = {10.1007/s13369-016-2316-y}, pages = {1103 -- 1116}, year = {2017}, abstract = {This paper presents the results of an eigenvalue analysis of the Fatih Sultan Mehmet Bridge. A high-resolution finite element model was created directly from the available design documents. All physical properties of the structural components were included in detail, so no calibration to the measured data was necessary. The deck and towers were modeled with shell elements. A nonlinear static analysis was performed before the eigenvalue calculation. The calculated natural frequencies and corresponding mode shapes showed good agreement with the available measured ambient vibration data. The calculation of the effective modal mass showed that nine modes had single contributions higher than 5 \% of the total mass. They were in a frequency range up to 1.2 Hz. The comparison of the results for the torsional modes especially demonstrated the advantage of using thin shell finite elements over the beam modeling approach.}, language = {en} } @article{ScheidweilerTriesch2016, author = {Scheidweiler, Robert and Triesch, Eberhard}, title = {A note on the duality between matchings and vertex covers in balanced hypergraphs}, series = {Journal of Combinatorial Optimization}, volume = {32}, journal = {Journal of Combinatorial Optimization}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {1573-2886}, doi = {10.1007/s10878-015-9887-5}, pages = {639 -- 644}, year = {2016}, abstract = {We present a new Min-Max theorem for an optimization problem closely connected to matchings and vertex covers in balanced hypergraphs. The result generalizes Kőnig's Theorem (Berge and Las Vergnas in Ann N Y Acad Sci 175:32-40, 1970; Fulkerson et al. in Math Progr Study 1:120-132, 1974) and Hall's Theorem (Conforti et al. in Combinatorica 16:325-329, 1996) for balanced hypergraphs.}, language = {en} } @article{BeckenbachScheidweiler2016, author = {Beckenbach, Isabel and Scheidweiler, Robert}, title = {Perfect ƒ-Matchings and ƒ-Factors in Hypergraphs - A Combinatorial Approach}, series = {Discrete Mathematics}, volume = {240}, journal = {Discrete Mathematics}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2192-7782}, doi = {10.1016/j.disc.2017.05.005}, pages = {2499 -- 2506}, year = {2016}, abstract = {We prove characterizations of the existence of perfect ƒ-matchings in uniform mengerian and perfect hypergraphs. Moreover, we investigate the ƒ-factor problem in balanced hypergraphs. For uniform balanced hypergraphs we prove two existence theorems with purely combinatorial arguments, whereas for non-uniform balanced hypergraphs we show that the ƒ-factor problem is NP-hard.}, language = {en} } @article{KosterScheidweilerTieves2016, author = {Koster, Arie and Scheidweiler, Robert and Tieves, Martin}, title = {A flow based pruning scheme for enumerative equitable coloring algorithms}, series = {A flow based pruning scheme for enumerative equitable coloring algorithms}, journal = {A flow based pruning scheme for enumerative equitable coloring algorithms}, doi = {10.48550/arXiv.1607.08754}, pages = {1 -- 30}, year = {2016}, abstract = {An equitable graph coloring is a proper vertex coloring of a graph G where the sizes of the color classes differ by at most one. The equitable chromatic number is the smallest number k such that G admits such equitable k-coloring. We focus on enumerative algorithms for the computation of the equitable coloring number and propose a general scheme to derive pruning rules for them: We show how the extendability of a partial coloring into an equitable coloring can be modeled via network flows. Thus, we obtain pruning rules which can be checked via flow algorithms. Computational experiments show that the search tree of enumerative algorithms can be significantly reduced in size by these rules and, in most instances, such naive approach even yields a faster algorithm. Moreover, the stability, i.e., the number of solved instances within a given time limit, is greatly improved. Since the execution of flow algorithms at each node of a search tree is time consuming, we derive arithmetic pruning rules (generalized Hall-conditions) from the network model. Adding these rules to an enumerative algorithm yields an even larger runtime improvement.}, language = {en} } @article{RieperGebhardtStucker2016, author = {Rieper, Harald and Gebhardt, Andreas and Stucker, Brent}, title = {Selective Laser Melting of the Eutectic Silver-Copper Alloy Ag 28 wt \% Cu}, series = {RTejournal - Forum f{\"u}r Rapid Technologie}, volume = {13}, journal = {RTejournal - Forum f{\"u}r Rapid Technologie}, issn = {1614-0923}, url = {http://nbn-resolving.de/nbn:de:0009-2-44141}, year = {2016}, abstract = {The aim of this work was to perform a detailed investigation of the use of Selective Laser Melting (SLM) technology to process eutectic silver-copper alloy Ag 28 wt. \% Cu (also called AgCu28). The processing occurred with a Realizer SLM 50 desktop machine. The powder analysis (SEM-topography, EDX, particle distribution) was reported as well as the absorption rates for the near-infrared (NIR) spectrum. Microscope imaging showed the surface topography of the manufactured parts. Furthermore, microsections were conducted for the analysis of porosity. The Design of Experiments approach used the response surface method in order to model the statistical relationship between laser power, spot distance and pulse time.}, language = {en} } @article{HaagZontarSchleupenetal.2014, author = {Haag, S. and Zontar, D. and Schleupen, Josef and M{\"u}ller, T. and Brecher, C.}, title = {Chain of refined perception in self-optimizing assembly of micro-optical systems}, series = {Journal of sensors and sensor systems}, volume = {3}, journal = {Journal of sensors and sensor systems}, number = {1}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, issn = {2194-878X}, doi = {10.5194/jsss-3-87-2014}, pages = {87 -- 95}, year = {2014}, abstract = {Today, the assembly of laser systems requires a large share of manual operations due to its complexity regarding the optimal alignment of optics. Although the feasibility of automated alignment of laser optics has been shown in research labs, the development effort for the automation of assembly does not meet economic requirements - especially for low-volume laser production. This paper presents a model-based and sensor-integrated assembly execution approach for flexible assembly cells consisting of a macro-positioner covering a large workspace and a compact micromanipulator with camera attached to the positioner. In order to make full use of available models from computer-aided design (CAD) and optical simulation, sensor systems at different levels of accuracy are used for matching perceived information with model data. This approach is named "chain of refined perception", and it allows for automated planning of complex assembly tasks along all major phases of assembly such as collision-free path planning, part feeding, and active and passive alignment. The focus of the paper is put on the in-process image-based metrology and information extraction used for identifying and calibrating local coordinate systems as well as the exploitation of that information for a part feeding process for micro-optics. Results will be presented regarding the processes of automated calibration of the robot camera as well as the local coordinate systems of part feeding area and robot base.}, language = {en} } @book{GebhardtHoetter2016, author = {Gebhardt, Andreas and H{\"o}tter, Jan-Steffen}, title = {Additive manufacturing : 3D printing for prototyping and manufacturing}, publisher = {Hanser Publishers}, address = {Munich}, isbn = {978-1-56990-582-1 ; 978-1-56990-583-8}, pages = {591 S.}, year = {2016}, language = {en} } @inproceedings{NakagawaKallweitMichauxetal.2016, author = {Nakagawa, Masaki and Kallweit, Stephan and Michaux, Frank and Hojo, Teppei}, title = {Typical Velocity Fields and Vortical Structures around a Formula One Car, based on Experimental Investigations using Particle Image Velocimetry}, series = {SAE International Journal of Passenger Cars - Mechanical Systems}, booktitle = {SAE International Journal of Passenger Cars - Mechanical Systems}, issn = {1946-4002}, doi = {10.4271/2016-01-1611}, pages = {18 S.}, year = {2016}, language = {en} }