@inproceedings{WittigRuettersBragard2024, author = {Wittig, M. and R{\"u}tters, Ren{\´e} and Bragard, Michael}, title = {Application of RL in control systems using the example of a rotatory inverted pendulum}, series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-02-3}, doi = {10.33968/2024.53}, pages = {241 -- 248}, year = {2024}, abstract = {In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.}, language = {en} } @misc{Huening2024, author = {H{\"u}ning, Felix}, title = {Positionssensorvorrichtung}, year = {2024}, abstract = {Die Erfindung betrifft eine Positionssensorvorrichtung zur Bestimmung einer Absolutposition eines beweglichen ersten Teils relativ zu einem ortsfesten zweiten Teil mit einem mit dem beweglichen ersten Teil gekoppelter Codek{\"o}rper, der dazu eingerichtet ist, eine Codespur mit einer Mehrzahl von in Spurrichtung aufeinanderfolgenden Codeelementen zu enthalten zur Bildung eines Codewortes, mit einer magnetischen Detektionseinrichtung zur Detektion der Codespur, wobei die Detektionseinrichtung zum einen an dem Codek{\"o}rper befestigte und entlang der Spurrichtung in einem solchen Abstand gegenpolig zueinander angeordnete Permanentmagneten aufweist, dass der Abstand mit einer vorgegebenen L{\"a}nge der jeweiligen Codeelemente {\"u}bereinstimmt, und zum anderen eine Anzahl von ortsfest und quer zu dem Codek{\"o}rper versetzt angeordnete Wiegandsensoren aufweist, wobei der Abstand des Wiegandsensors zu einer Erstreckungsebene der Permanentmagneten derart gew{\"a}hlt ist, dass bei {\"U}berdeckung des Wiegandsensors durch den Permanentmagneten ein Wiegandpuls in dem Wiegandsensor induziert wird.}, language = {de} } @inproceedings{KramerBragardRitzetal.2024, author = {Kramer, Pia and Bragard, Michael and Ritz, Thomas and Ferfer, Ute and Schiffers, Tim}, title = {Visualizing, Enhancing and Predicting Students' Success through ECTS Monitoring}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578652}, pages = {5 Seiten}, year = {2024}, abstract = {This paper serves as an introduction to the ECTS monitoring system and its potential applications in higher education. It also emphasizes the potential for ECTS monitoring to become a proactive system, supporting students by predicting academic success and identifying groups of potential dropouts for tailored support services. The use of the nearest neighbor analysis is suggested for improving data analysis and prediction accuracy.}, language = {en} } @article{SchoppRohrbachLangeretal.2024, author = {Schopp, Christoph and Rohrbach, Felix and Langer, Luc and Heuermann, Holger}, title = {Detection of welding wire length by active S11 measurement}, series = {IEEE Transactions on Plasma Science}, journal = {IEEE Transactions on Plasma Science}, number = {Early Access}, publisher = {IEEE}, issn = {0093-3813 (Print)}, doi = {10.1109/TPS.2024.3356659}, pages = {1 -- 6}, year = {2024}, abstract = {A novel method to determine the extruded length of a metallic wire for a directed energy deposition (DED) process using a microwave (MW) plasma jet with a straight-through wire feed is presented. The method is based on the relative comparison of the measured frequency response obtained by the large-signal scattering parameter (Hot-S) technique. In the practical working range, repeatability of less than 6\% for a nonactive plasma and 9\% for the active plasma state is found. Measurements are conducted with a focus on a simple solution to decrease the processing time and reduce the integration time of the process into the existing hardware. It is shown that monitoring a single frequency for magnitude and phase changes is sufficient to achieve good accuracy. A combination of different measurement values to determine the length is possible. The applicability to different diameter of the same material is shown as well as a contact detection of the wire and metallic substrate.}, language = {en} } @techreport{HoffmannUllrich2024, type = {Working Paper}, author = {Hoffmann, Sarah and Ullrich, Anna Valentine}, title = {30 Minuten FDM f{\"u}r HAW. Ein Informationsformat f{\"u}r Forschende an HAW in NRW}, doi = {10.5281/zenodo.12569282}, pages = {1 Seite}, year = {2024}, abstract = {Wie kann man das Thema Forschungsdatenmanagement (FDM) konkret und anwendbar f{\"u}r Forschende gestalten, die bisher noch wenig Kontakt damit hatten? Auf diese Frage gibt das Konzept „30 Minuten FDM f{\"u}r HAW. Ein Informationsformat f{\"u}r Forschende an HAW in NRW" eine Antwort. Es entstand als Projektarbeit im Zertifikatskurs Forschungsdatenmanagement 2023/24}, language = {de} } @article{WindmuellerSchapsZantisetal.2024, author = {Windm{\"u}ller, Anna and Schaps, Kristian and Zantis, Frederik and Domgans, Anna and Taklu, Bereket Woldegbreal and Yang, Tingting and Tsai, Chih-Long and Schierholz, Roland and Yu, Shicheng and Kungl, Hans and Tempel, Hermann and Dunin-Borkowski, Rafal E. and H{\"u}ning, Felix and Hwang, Bing Joe and Eichel, R{\"u}diger-A.}, title = {Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries}, series = {ACS Applied Materials \& Interfaces}, volume = {16}, journal = {ACS Applied Materials \& Interfaces}, number = {30}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {39181-3919}, doi = {10.1021/acsami.4c03729}, pages = {14 Seiten}, year = {2024}, abstract = {Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use.}, language = {en} } @techreport{BarnatArntzBerneckeretal.2024, type = {Working Paper}, author = {Barnat, Miriam and Arntz, Kristian and Bernecker, Andreas and Fissabre, Anke and Franken, Norbert and Goldbach, Daniel and H{\"u}ning, Felix and J{\"o}rissen, J{\"o}rg and Kirsch, Ansgar and Pettrak, J{\"u}rgen and Rexforth, Matthias and Josef, Rosenkranz and Terstegge, Andreas}, title = {Strategische Gestaltung von Studieng{\"a}ngen f{\"u}r die Zukunft: Ein kollaborativ entwickeltes Self-Assessment}, series = {Hochschulforum Digitalisierung - Diskussionspapier}, journal = {Hochschulforum Digitalisierung - Diskussionspapier}, publisher = {Stifterverband f{\"u}r die Deutsche Wissenschaft}, address = {Berlin}, issn = {2365-7081}, pages = {16 Seiten}, year = {2024}, abstract = {Das Diskussionspapier beschreibt einen Prozess an der FH Aachen zur Entwicklung und Implementierung eines Self-Assessment-Tools f{\"u}r Studieng{\"a}nge. Dieser Prozess zielte darauf ab, die Relevanz der Themen Digitalisierung, Internationalisierung und Nachhaltigkeit in Studieng{\"a}ngen zu st{\"a}rken. Durch Workshops und kollaborative Entwicklung mit Studiendekan:innen entstand ein Fragebogen, der zur Reflexion und strategischen Weiterentwicklung der Studieng{\"a}nge dient.}, language = {de} } @techreport{BirmansTamborninoUllrich2024, type = {Working Paper}, author = {Birmans, Katrin and Tambornino, Philipp and Ullrich, Anna Valentine}, title = {Bevor Sie Coscine nutzen - Handreichung f{\"u}r Forschende an HAW}, doi = {10.5281/zenodo.12158546}, pages = {2 Seiten}, year = {2024}, abstract = {Um die Forschungsdatenmanagement-Plattform Coscine optimal f{\"u}r Forschungsprojekte nutzen zu k{\"o}nnen, ist es sinnvoll, einige Fragen im Vorhinein zu kl{\"a}ren. So k{\"o}nnen aufwendige {\"A}nderungen der Datenverwaltung im Nachhinein vermieden werden. Hierzu bietet die Handreichung hilfreiche Leitfragen und Erl{\"a}uterungen f{\"u}r Forschende und FDM-Service-Personal an HAW in NRW (DH.NRW-Hochschulen). FDM-Service-Mitarbeitende k{\"o}nnen die Handreichung in ihrer Beratung zu Coscine einsetzen und mit der Eingabemaske in der Kopfzeile des Dokuments auf ihre Hochschule anpassen.}, language = {de} } @inproceedings{RuettersBragardDolls2024, author = {R{\"u}tters, Ren{\´e} and Bragard, Michael and Dolls, Sarah}, title = {The Inverted Rotary Pendulum: Facilitating Practical Teaching in Advanced Control Engineering}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578937}, pages = {5 Seiten}, year = {2024}, abstract = {This paper outlines a practical approach to teach control engineering principles, with an inverted rotary pendulum, serving as an illustrative example. It shows how the pendulum is embedded in an advanced course of control engineering. This approach is incorporated into a flipped-classroom concept, as well as classical teaching concepts, offering students practical experience in control engineering. In addition, the design of the pendulum is shown, using a Raspberry Pi as the target platform for Matlab Simulink. This pendulum can be used in the classroom to evaluate the controller design mentioned above. It is analysed if the use of the pendulum generates a deeper understanding of the learning contents.}, language = {en} } @inproceedings{BeckerBragard2024, author = {Becker, Tim and Bragard, Michael}, title = {Low-Voltage DC Training Lab for Electric Drives - Optimizing the Balancing Act Between High Student Throughput and Individual Learning Speed}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578902}, pages = {8 Seiten}, year = {2024}, abstract = {After a brief introduction of conventional laboratory structures, this work focuses on an innovative and universal approach for a setup of a training laboratory for electric machines and drive systems. The novel approach employs a central 48 V DC bus, which forms the backbone of the structure. Several sets of DC machine, asynchronous machine and synchronous machine are connected to this bus. The advantages of the novel system structure are manifold, both from a didactic and a technical point of view: Student groups can work on their own performance level in a highly parallelized and at the same time individualized way. Additional training setups (similar or different) can easily be added. Only the total power dissipation has to be provided, i.e. the DC bus balances the power flow between the student groups. Comparative results of course evaluations of several cohorts of students are shown.}, language = {en} }