@inproceedings{UlmerBraunChengetal.2021, author = {Ulmer, Jessica and Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Adapting augmented reality systems to the users' needs using gamification and error solving methods}, series = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0}, volume = {104}, booktitle = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, doi = {10.1016/j.procir.2021.11.024}, pages = {140 -- 145}, year = {2021}, abstract = {Animations of virtual items in AR support systems are typically predefined and lack interactions with dynamic physical environments. AR applications rarely consider users' preferences and do not provide customized spontaneous support under unknown situations. This research focuses on developing adaptive, error-tolerant AR systems based on directed acyclic graphs and error resolving strategies. Using this approach, users will have more freedom of choice during AR supported work, which leads to more efficient workflows. Error correction methods based on CAD models and predefined process data create individual support possibilities. The framework is implemented in the Industry 4.0 model factory at FH Aachen.}, language = {en} } @inproceedings{Huening2021, author = {H{\"u}ning, Felix}, title = {Sustainable changes beyond covid-19 for a second semester physics course for electrical engineering students}, series = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?}, booktitle = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?}, isbn = {978-2-87352-023-6}, pages = {1424 -- 1428}, year = {2021}, abstract = {The course Physics for Electrical Engineering is part of the curriculum of the bachelor program Electrical Engineering at University of Applied Science Aachen. Before covid-19 the course was conducted in a rather traditional way with all parts (lecture, exercise and lab) face-to-face. This teaching approach changed fundamentally within a week when the covid-19 limitations forced all courses to distance learning. All parts of the course were transformed to pure distance learning including synchronous and asynchronous parts for the lecture, live online-sessions for the exercises and self-paced labs at home. Using these methods, the course was able to impart the required knowledge and competencies. Taking the teacher's observations of the student's learning behaviour and engagement, the formal and informal feedback of the students and the results of the exams into account, the new methods are evaluated with respect to effectiveness, sustainability and suitability for competence transfer. Based on this analysis strong and weak points of the concept and countermeasures to solve the weak points were identified. The analysis further leads to a sustainable teaching approach combining synchronous and asynchronous parts with self-paced learning times that can be used in a very flexible manner for different learning scenarios, pure online, hybrid (mixture of online and presence times) and pure presence teaching.}, language = {en} } @inproceedings{KernImaniVashianiTimmermanns2021, author = {Kern, Alexander and Imani Vashiani, Anahita and Timmermanns, Tobias}, title = {Threat for human beings due to touch voltages and body currents caused by direct lightning strikes in case of non-isolated lightning protection systems using natural components}, series = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, booktitle = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-1-6654-2346-5}, doi = {10.1109/ICLPandSIPDA54065.2021.9627465}, pages = {8 Seiten}, year = {2021}, abstract = {For typical cases of non-isolated lightning protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal fa{\c{c}}ades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS. As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal fa{\c{c}}ade is used the threat for human beings touching is usually very low, if the fa{\c{c}}ade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp.}, language = {en} } @inproceedings{PfeifferBalcGebhardt2021, author = {Pfeiffer, Johann and Balc, N. and Gebhardt, Andreas}, title = {Studie zur Untersuchung der Auswirkung von Fr{\"a}sbahnstrategien auf die Oberfl{\"a}chenqualit{\"a}t von mittels SLM gefertigten Metallteilen}, series = {Tagungsband 21. Nachwuchswissenschaftler*innenkonferenz}, booktitle = {Tagungsband 21. Nachwuchswissenschaftler*innenkonferenz}, publisher = {Verlag Ernst-Abbe-Hochschule Jena}, address = {Jena}, isbn = {978-3-932886-36-2}, pages = {99 -- 102}, year = {2021}, abstract = {F{\"u}r die Herstellung von metallischen Bauteilen wird in der heutigen Zeit eine Vielzahl von Verfahren auf dem Markt angeboten. Dabei stehen die additiven im Wettbewerb zu den konventionellen Verfahren. Die erreichbaren Oberfl{\"a}chenqualit{\"a}ten der additiven sind nicht mit denen spanender Verfahren vergleichbar. F{\"u}r diesen Beitrag wurde analysiert, ob sich ein mittels Selektivem Laserschmelzen (SLM) additiv hergestellter Edelstahl hinsichtlich seiner Oberfl{\"a}chenqualit{\"a}t nach der Zerspanung von einem umgeformten konventionell hergestellten Edelstahl gleicher Sorte unterscheidet.}, language = {de} } @inproceedings{EnglhardWeberArent2021, author = {Englhard, Markus and Weber, Tobias and Arent, Jan-Christoph}, title = {Efficiency enhancement for CFRP-Prepregautoclave manufacturing by means of simulation-assisted loading optimization}, series = {Proceedings of SAMPE Europe Conference 2021}, booktitle = {Proceedings of SAMPE Europe Conference 2021}, pages = {8 Seiten}, year = {2021}, abstract = {A new method for improved autoclave loading within the restrictive framework of helicopter manufacturing is proposed. It is derived from experimental and numerical studies of the curing process and aims at optimizing tooling positions in the autoclave for fast and homogeneous heat-up. The mold positioning is based on two sets of information. The thermal properties of the molds, which can be determined via semi-empirical thermal simulation. The second information is a previously determined distribution of heat transfer coefficients inside the autoclave. Finally, an experimental proof of concept is performed to show a cycle time reduction of up to 31\% using the proposed methodology.}, language = {en} } @inproceedings{NikolovskiRekeElsenetal.2021, author = {Nikolovski, Gjorgji and Reke, Michael and Elsen, Ingo and Schiffer, Stefan}, title = {Machine learning based 3D object detection for navigation in unstructured environments}, series = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, booktitle = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, publisher = {IEEE}, isbn = {978-1-6654-7921-9}, doi = {10.1109/IVWorkshops54471.2021.9669218}, pages = {236 -- 242}, year = {2021}, abstract = {In this paper we investigate the use of deep neural networks for 3D object detection in uncommon, unstructured environments such as in an open-pit mine. While neural nets are frequently used for object detection in regular autonomous driving applications, more unusual driving scenarios aside street traffic pose additional challenges. For one, the collection of appropriate data sets to train the networks is an issue. For another, testing the performance of trained networks often requires tailored integration with the particular domain as well. While there exist different solutions for these problems in regular autonomous driving, there are only very few approaches that work for special domains just as well. We address both the challenges above in this work. First, we discuss two possible ways of acquiring data for training and evaluation. That is, we evaluate a semi-automated annotation of recorded LIDAR data and we examine synthetic data generation. Using these datasets we train and test different deep neural network for the task of object detection. Second, we propose a possible integration of a ROS2 detector module for an autonomous driving platform. Finally, we present the performance of three state-of-the-art deep neural networks in the domain of 3D object detection on a synthetic dataset and a smaller one containing a characteristic object from an open-pit mine.}, language = {en} } @inproceedings{RitschelStenzelCzarneckietal.2021, author = {Ritschel, Konstantin and Stenzel, Adina and Czarnecki, Christian and Hong, Chin-Gi}, title = {Realizing robotic process automation potentials: an architectural perspective on a real-life implementation case}, series = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, booktitle = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, editor = {Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885797081}, issn = {1617-5468}, doi = {10.18420/informatik2021-108}, pages = {1303 -- 1311}, year = {2021}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through a simple emulation of user input and output by software robots. Hence, it can be assumed that no changes of the used software systems and existing Enterprise Architecture (EA) is required. In this short, practical paper we discuss this assumption based on a real-life implementation project. We show that a successful RPA implementation might require architectural work during analysis, implementation, and migration. As practical paper we focus on exemplary lessons-learned and new questions related to RPA and EA.}, language = {en} } @inproceedings{FiedlerGottschlichMuellerMelcher2021, author = {Fiedler, Gerda and Gottschlich-M{\"u}ller, Birgit and Melcher, Karin}, title = {Online-Pr{\"u}fungen mit STACK Aufgaben}, series = {Tagungsband ASIM Workshop STS/GMMS/EDU 2021}, booktitle = {Tagungsband ASIM Workshop STS/GMMS/EDU 2021}, editor = {Liu-Henke, Xiaobo and Durak, Umut}, publisher = {ARGESIM Verlag}, address = {Wien}, isbn = {978-3-901608-69-8}, doi = {10.11128/arep.45}, pages = {173 -- 178}, year = {2021}, abstract = {Wir stellen hier exemplarisch STACK Aufgaben vor, die frei von der Problematik sind, welche sich durch diverse Kommunikationswege und (webbasierte) Computer Algebra Systeme (CAS) ergibt. Daher sind sie insbesondere f{\"u}r eine Open-Book Online Pr{\"u}fung geeignet, da eine faire Pr{\"u}fungssituation gew{\"a}hrleistet werden kann.}, language = {de} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska}, title = {Numerical investigation of micromix hydrogen flames at different combustor pressure levels}, series = {The Proceedings of the International Conference on Power Engineering (ICOPE)}, booktitle = {The Proceedings of the International Conference on Power Engineering (ICOPE)}, doi = {10.1299/jsmeicope.2021.15.2021-0237}, pages = {4 Seiten}, year = {2021}, abstract = {This study investigates the influence of pressure on the temperature distribution of the micromix (MMX) hydrogen flame and the NOx emissions. A steady computational fluid dynamic (CFD) analysis is performed by simulating a reactive flow with a detailed chemical reaction model. The numerical analysis is validated based on experimental investigations. A quantitative correlation is parametrized based on the numerical results. We find, that the flame initiation point shifts with increasing pressure from anchoring behind a downstream located bluff body towards anchoring upstream at the hydrogen jet. The numerical NOx emissions trend regarding to a variation of pressure is in good agreement with the experimental results. The pressure has an impact on both, the residence time within the maximum temperature region and on the peak temperature itself. In conclusion, the numerical model proved to be adequate for future prototype design exploration studies targeting on improving the operating range.}, language = {en} } @inproceedings{HorikawaOkadaYamaguchietal.2021, author = {Horikawa, Atsushi and Okada, Kunio and Yamaguchi, Masato and Aoki, Shigeki and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Combustor development and engine demonstration of micro-mix hydrogen combustion applied to M1A-17 gas turbine}, series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions}, booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions}, doi = {10.1115/GT2021-59666}, pages = {13 Seiten}, year = {2021}, abstract = {Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B\&B-AGEMA have investigated the possibility of low NOx micro-mix hydrogen combustion and its application to an industrial gas turbine combustor. From 2014 to 2018, KHI developed a DLN hydrogen combustor for a 2MW class industrial gas turbine with the micro-mix technology. Thereby, the ignition performance, the flame stability for equivalent rotational speed, and higher load conditions were investigated. NOx emission values were kept about half of the Air Pollution Control Law in Japan: 84ppm (O2-15\%). Hereby, the elementary combustor development was completed. From May 2020, KHI started the engine demonstration operation by using an M1A-17 gas turbine with a co-generation system located in the hydrogen-fueled power generation plant in Kobe City, Japan. During the first engine demonstration tests, adjustments of engine starting and load control with fuel staging were investigated. On 21st May, the electrical power output reached 1,635 kW, which corresponds to 100\% load (ambient temperature 20 °C), and thereby NOx emissions of 65 ppm (O2-15, 60 RH\%) were verified. Here, for the first time, a DLN hydrogen-fueled gas turbine successfully generated power and heat.}, language = {en} }