@inproceedings{46957, abstract = {{Modern companies often face various challenges in concept development of products or systems. Design engineers prepare initial concepts as 3D models. These are then simulated by computational engineers. If requirements are not met, this necessitates an iterative process that runs between the design and computation departments until a valid concept is created. Design methods such as topology optimization are often used here. The upcoming result is then attempted to be adapted to certain manufacturing processes. These iteration loops can sometimes take a very long time, since the model construction and structural optimization generate large computational efforts. The present work shows on an example a methodical approach, which represents a first proof of concept, to solving this problem, including a description of methods and techniques, as well as possible problems in a detailed analysis concerning training data for neural networks and their abstraction capabilities. It is evident that additional research work needs to be conducted for further utilization in order to address all arising questions.}}, author = {{Ott, Manuel and Meihöfener, Niclas and Mozgova, Iryna}}, booktitle = {{Proceedings of the 34rd Annual International Solid Freeform Fabrication Symposium 2023}}, editor = {{Ott, Manuel}}, location = {{Austin, Texas, United States}}, title = {{{Methodical Approach to Reducing Design Time by using Neural Networks in Early Stages of Concept Development}}}, year = {{2023}}, } @article{47122, abstract = {{AbstractFeCo alloys are important materials used in pumps and motors in the offshore oil and gas drilling industry. These alloys are subjected to marine environments with a high NaCl concentration, therefore, corrosion and catastrophic failure are anticipated. So, the surface dissolution of additively manufactured FeCo samples is investigated in a quasi-in situ manner, in particular, the pitting corrosion in 5.0 wt pct NaCl solution. The local dissolution of the same sample region is monitored after 24, 72, and 168 hours. Here, the formation of rectangular and circular pits of ultra-fine dimensions (less than 0.5 µm) is observed with increasing immersion time. In addition, the formation of a corrosion-inhibiting surface layer is detected on the sample surface. Surface dissolution leads to a change in the surface structure, however, no change in grain shape or grain size is noticed. The surface topography after local dissolution is correlated to the grain orientation. Quasi-in situ analysis shows the preferential dissolution of high-angle grain boundaries (HAGBs) leading to a change in the fraction of HAGBs and low-angle grain boundaries fraction (LAGBs). For the FeCo sample, a potentiodynamic polarisation test reveals a corrosion potential (Ecorr) of − 0.475 V referred to the standard hydrogen electrode (SHE) and a corrosion exchange current density (icorr) of 0.0848 A/m2. Furthermore, quasi-in situ experiments showed that grains oriented along certain crystallographic directions are corroding more compared to other grains leading to a significant decrease in the local surface height. Grains with a plane normal close to the $$\langle {1}00\rangle$$ ⟨ 100 ⟩ direction reveal lower surface dissolution and higher corrosion resistance, whereas planes normal close to the $$\langle {11}0\rangle$$ ⟨ 110 ⟩ direction and the $$\langle {111}\rangle$$ ⟨ 111 ⟩ direction exhibit a higher surface dissolution.}}, author = {{Pramanik, Sudipta and Krüger, Jan Tobias and Schaper, Mirko and Hoyer, Kay-Peter}}, issn = {{1073-5623}}, journal = {{Metallurgical and Materials Transactions A}}, keywords = {{Metals and Alloys, Mechanics of Materials, Condensed Matter Physics}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Quasi-In Situ Localized Corrosion of an Additively Manufactured FeCo Alloy in 5 Wt Pct NaCl Solution}}}, doi = {{10.1007/s11661-023-07186-7}}, year = {{2023}}, } @inproceedings{46813, abstract = {{Modelling of dynamic systems plays an important role in many engineering disciplines. Two different approaches are physical modelling and data‐driven modelling, both of which have their respective advantages and disadvantages. By combining these two approaches, hybrid models can be created in which the respective disadvantages are mitigated, with discrepancy models being a particular subclass. Here, the basic system behaviour is described physically, that is, in the form of differential equations. Inaccuracies resulting from insufficient modelling or numerics lead to a discrepancy between the measurements and the model, which can be compensated by a data‐driven error correction term. Since discrepancy methods still require a large amount of measurement data, this paper investigates the extent to which a single discrepancy model can be trained for a physical model with additional parameter dependencies without the need for retraining. As an example, a damped electromagnetic oscillating circuit is used. The physical model is realised by a differential equation describing the electric current, considering only inductance and capacitance; dissipation due to resistance is neglected. This creates a discrepancy between measurement and model, which is corrected by a data‐driven model. In the experiments, the inductance and the capacity are varied. It is found that the same data‐driven model can only be used if additional parametric dependencies in the data‐driven term are considered as well.}}, author = {{Wohlleben, Meike Claudia and Muth, Lars and Peitz, Sebastian and Sextro, Walter}}, booktitle = {{Proceedings in Applied Mathematics and Mechanics}}, issn = {{1617-7061}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics}}, publisher = {{Wiley}}, title = {{{Transferability of a discrepancy model for the dynamics of electromagnetic oscillating circuits}}}, doi = {{10.1002/pamm.202300039}}, year = {{2023}}, } @article{44312, abstract = {{Zusammenfassung Aufgrund aktueller Transformationsprozesse kommt der automatisierten und ressourceneffizienten Fertigung hochfester Leichtbauteile eine steigende Bedeutung zu, beispielsweise im Flugzeug- und Fahrzeugbau. Für kleine Losgrößen bietet sich hier insbesondere das Fertigungsverfahren des Drückwalzens an. Der konventionelle, industriell genutzte Drückwalzprozess stößt allerdings aufgrund der Prozesskomplexität hinsichtlich der Reproduzierbarkeit an seine Grenzen. Dies wird in der Praxis teilweise durch personengebundenes Erfahrungswissen kompensiert. Auch ist es nicht möglich, Bauteileigenschaften definiert einzustellen. Aus diesem Grund bietet der Einsatz einer neuartigen Eigenschaftsregelung Chancen zur Weiterentwicklung des Fertigungsprozesses und die Möglichkeit zur Prozessautomatisierung. Hier werden die Werkzeugbahnen abhängig einer Online-Eigenschaftsmessung über eine zusätzliche Reglerkaskade manipuliert. Die Entwicklung einer solchen Eigenschaftsregelung erfordert den Einsatz geeigneter, modellbasierter Entwurfsmethoden. In diesem Beitrag wird daher ein regelungstechnisches Systemmodell für das Drückwalzen metastabiler austenitischer Edelstähle vorgestellt. Das Simulationsmodell weist aufgrund seiner Echtzeitfähigkeit neben dem Einsatz als reines Entwurfsmodell weitere Nutzungsmöglichkeiten z.B. in Beobachtern auf und grenzt sich somit von domänenspezifischen Simulationstools wie der FEM ab.}}, author = {{Kersting, Lukas and Arian, Bahman and Rozo Vasquez, Julian and Trächtler, Ansgar and Homberg, Werner and Walther, Frank}}, issn = {{0178-2312}}, journal = {{at - Automatisierungstechnik}}, keywords = {{Electrical and Electronic Engineering, Computer Science Applications, Control and Systems Engineering}}, number = {{1}}, pages = {{68--81}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Echtzeitfähige Modellierung eines innovativen Drückwalzprozesses für die eigenschaftsgeregelte Bauteilfertigung}}}, doi = {{10.1515/auto-2022-0106}}, volume = {{71}}, year = {{2023}}, } @inproceedings{44315, abstract = {{Abstract. Climate change, rare resources and industrial transformation processes lead to a rising demand of multi-complex lightweight forming parts, especially in aerospace and automotive sectors. In these industries, flow forming is often used to produce cylindrical forming parts by reducing the wall thickness of tubular semifinished parts, e.g. for the production of hydraulic cylinders or gear shafts. The complexity and functionality of flow forming workpieces could be significantly increased by locally graded microstructure and geometry structures. This enables customized complex hardness distributions at wear surfaces or magnetic QR codes for a unique, tamper-proof product identification. The production of those complex, 2D (axial and angular) graded forming parts currently depicts a great challenge for the process and requires new solutions and strategies. Hence, this paper proposes a novel control strategy that includes online measurements from an absolute encoder to determine the angular workpiece position. Workpieces of AISI 304L stainless steel with 2D-graded structures are successfully manufactured using this new strategy and analyzed regarding the possible accuracy and resolution of the gradation. At this point, a dependency of the gradations on the sensor and actuator dynamics, accuracy and geometry could be noted. It is further evaluated how the control strategy could be extended by an observer-based closed-loop property control approach to enhance the accuracy of the suggested strategy. }}, author = {{Kersting, Lukas and Arian, Bahman and Rozo Vasquez, Julian and Trächtler, Ansgar and Homberg, Werner and Walther, Frank}}, booktitle = {{Materials Research Proceedings}}, issn = {{2474-395X}}, publisher = {{Materials Research Forum LLC}}, title = {{{Control strategy for angular gradations by means of the flow forming process}}}, doi = {{10.21741/9781644902479-220}}, year = {{2023}}, } @article{44318, author = {{Rozo Vasquez, Julian and Arian, Bahman and Kersting, Lukas and Walther, Frank and Homberg, Werner and Trächtler, Ansgar}}, journal = {{Metals}}, title = {{{Detection of phase transformation during plastic deformation of metastable austenitic steel AISI 304L by means of X-ray diffraction pattern analysis}}}, year = {{2023}}, } @inproceedings{47234, author = {{Sehlmeyer, Birte and Kampmann, Rebecca and Scheidemann, Claus and Hemsel, Tobias and Getzlaff, Mathias }}, booktitle = {{Frühjahrstagung 2023, Sektion Kondensierte Materie (SKM)}}, location = {{Dresden}}, title = {{{Burst Mode of Ultrasonic Resonant Oscillations for Stimulation and Destruction of Tumor Cells}}}, year = {{2023}}, } @inproceedings{47235, author = {{Kampmann, Rebecca and Sehlmeyer, Birte and Scheidemann, Claus and Hemsel, Tobias and Getzlaff, Mathias}}, booktitle = {{Frühjahrstagung 2023, Sektion Kondensierte Marterie (SKM)}}, location = {{Dresden}}, title = {{{Burst Mode Characteristics of an Ultrasonic Transducer for Treatment of Cancer Cells}}}, year = {{2023}}, } @inproceedings{56626, author = {{Holzmüller, Maik and Gong, Yi and Bader, Fabian and Henke, Armin and Homberg, Werner}}, booktitle = {{Lecture Notes in Mechanical Engineering}}, isbn = {{9783031410222}}, issn = {{2195-4356}}, publisher = {{Springer Nature Switzerland}}, title = {{{Numerical Approach to Model a Novel Electrohydraulic Incremental Forming Process for the Manufacture of Pillow Plate Heat Exchangers}}}, doi = {{10.1007/978-3-031-41023-9_69}}, year = {{2023}}, } @misc{56827, abstract = {{Zusammenfassung: Die Erfindung betrifft ein Verkehrsleitsystem für die Steuerung von Lichtsignalanlagen aufweisend: • Eingänge für Verkehrszustandsermittlungsverfahren abhängig von verschiedenen Sensoren, wobei die Sensoren einen aktuellen Verkehrszustand eines zugeordneten Verkehrsabschnitts ermitteln, • Statusregister, die den aktuellen Status der gesteuerten Lichtsignalanlagen speichern, • Phasenregister, die alle möglichen Verkehrsleitphasen, die durch die Lichtsignalanlagen angesteuert werden können, speichern, • eine Fuzzy-Logik (F) zur Vorselektion von möglichen Verkehrsleitphasen basierend auf einem aktuellen Verkehrszustand, wobei für jede mögliche Verkehrsleitphase basierend auf dem aktuellen Verkehrszustand ein Prioritätswert ermittelt wird, wobei für die weitere Verarbeitung nur eine vorbestimmte Anzahl von vorselektierten nachfolgenden Verkehrsleitphasen anhand der Priorität ausgewählt wird, • wobei die so vorausgewählten Verkehrsleitphasen einer modellprädiktiven Regelung mit einer Verkehrsprädiktionssimulation (MPC) zugeführt werden, wobei die Regelung basierend auf den Phasenfolgen (gebildet aus den vorselektierten Verkehrsleitphasen), dem aktuellen Verkehrszustand und dem aktuellen Status der gesteuerten Lichtsignalanlagen eine geeignete prädiktive zeitliche Phasensteuerung ermittelt, wobei die Schaltzeitpunkte der Phasenfolgen durch ein Optimierungsverfahren berechnet werden, • wobei die so ermittelte prädiktive zeitliche Phasensteuerung keine, eine oder mehrere zu schaltenden Folgephasen mit den ermittelten Schaltzeitpunkten aufweist, • wobei anhand der Bewertungen der einzelnen prädiktiven zeitlichen Phasensteuerungen ermittelt wird, welche der prädiktiven zeitlichen Phasensteuerungen zur weiteren Steuerung der Lichtsignalanlagen ausgewählt und verwendet wird.}}, author = {{Malena, Kevin and Link, Christopher and Gausemeier, Sandra and Trächtler, Ansgar}}, title = {{{Vorrichtung und Verfahren zur echtzeit-basierten dynamischen Verkehrszuordnung für zumindest zwei nachfolgende Fahrbahnen}}}, year = {{2023}}, } @phdthesis{56937, abstract = {{Ein Trend in der Produktion sind individualisierte Produkte und damit eine höhere Variantenvielfalt, die idealerweise durch effiziente Produktionsprozesse hergestellt werden. Effizienz bedeutet in diesem Fall, dass die Produkte kostengünstig und bedarfsgerecht hergestellt werden. Der Trend geht hierbei auch in der Massenproduktion zu einer flexiblen Produktion, um das gebundene Kapital zu reduzieren und zeitnah auf Kundenwünsche reagieren zu können. Dies führt zu einem häufigeren Umrüsten der Werkzeuge in den Maschinen und somit zu einem immer häufigeren Einrichten der Prozesse.In dieser Arbeit wird eine Systematik für ein adaptives Einrichtassistenzsystem entwickelt, welches den Maschinenbediener beim Einrichten mithilfe eines definierten Vorgehens durch den Prozess leitet. Der Bediener wird dabei unterstützt die momentane Produktqualität zu bewerten und bekommt einen quantitativen Vorschlag zur Variation der Justagemöglichkeiten. So kann der Einrichtprozess zielgerichteter und fehlerfreier durchgeführt werden. Ermöglicht wird dies durch die Abbildung des notwendigen Expertenwissens in datengetriebenen Modellen. Mithilfe des so abgebildeten Expertenwissens werden optimierte Einstellungen berechnet und am Werkzeug eingestellt. Es ist nicht davon auszugehen, dass das virtualisierte Expertenwissen die Realität allumfassend abbilden und alle akuten Umwelteinflüsse messtechnisch ermittelt werden können. Etwaige Abweichungen der Produktqualität werden direkt in der entwickelten Optimierung und bei Bedarf mithilfe der vorgeschlagenen Kompensationsstrategie eliminiert.Die Systematik wird anhand eines Folgeverbundprozesses validiert. Nach der Analyse des Prozesses werden die wesentlichen Komponenten für das System entwickelt und mithilfe von Versuchen und Simulationen die Funktionsfähigkeit erfolgreich nachgewiesen.}}, author = {{Gräler, Manuel}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}}, title = {{{Entwicklung adaptiver Einrichtassistenzsysteme für Produktionsprozesse}}}, doi = {{10.17619/UNIPB/1-1894}}, volume = {{417}}, year = {{2023}}, } @misc{42997, author = {{Almohammad, Ahmad and Neukötter, Moritz}}, title = {{{Untersuchung dehnrheologischer Eigenschaften - Suspensionen auf Basis von Polymerlösungen }}}, year = {{2023}}, } @misc{56951, author = {{Otto, Moritz and Neukötter, Moritz}}, title = {{{Konstruktion einer Vorrichtung zur Probenherstellung für das Sermanat-Dehnrheometer}}}, year = {{2023}}, } @misc{56953, author = {{Gunasagran, Sharin Kumar and Neukötter, Moritz}}, title = {{{Automatisierung der Auswertungen rheologischer Messungen (Studienarbeit)}}}, year = {{2023}}, } @misc{42995, author = {{Al Mamoun, Mohamed and Neukötter, Moritz}}, title = {{{Evaluation of self-built low-budget particle sensors (Study Project)}}}, year = {{2023}}, } @inproceedings{44102, author = {{Neukötter, Moritz and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, location = {{Athens}}, title = {{{Instabilities of Polymer Melt Suspensions under Uniaxial Extension (Poster)}}}, year = {{2023}}, } @inproceedings{34171, abstract = {{State estimation when only a partial model of a considered system is available remains a major challenge in many engineering fields. This work proposes a joint, square-root unscented Kalman filter to estimate states and model uncertainties simultaneously by linear combinations of physics-motivated library functions. Using a sparsity promoting approach, a selection of those linear combinations is chosen and thus an interpretable model can be extracted. Results indicate a small estimation error compared to a traditional square-root unscented Kalman filter and exhibit the enhancement of physically meaningful models.}}, author = {{Götte, Ricarda-Samantha and Timmermann, Julia}}, booktitle = {{12th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2022)}}, keywords = {{joint estimation, unscented transform, Kalman filter, sparsity, data-driven, compressed sensing}}, location = {{Canberra, Australien}}, number = {{1}}, pages = {{85--90}}, title = {{{Estimating States and Model Uncertainties Jointly by a Sparsity Promoting UKF}}}, doi = {{https://doi.org/10.1016/j.ifacol.2023.02.015}}, volume = {{56}}, year = {{2023}}, } @inproceedings{44326, abstract = {{Low-quality models that miss relevant dynamics lead to major challenges in modelbased state estimation. We address this issue by simultaneously estimating the system’s states and its model inaccuracies by a square root unscented Kalman filter (SRUKF). Concretely, we augment the state with the parameter vector of a linear combination containing suitable functions that approximate the lacking dynamics. Presuming that only a few dynamical terms are relevant, the parameter vector is claimed to be sparse. In Bayesian setting, properties like sparsity are expressed by a prior distribution. One common choice for sparsity is a Laplace distribution. However, due to disadvantages of a Laplacian prior in regards to the SRUKF, the regularized horseshoe distribution, a Gaussian that approximately features sparsity, is applied instead. Results exhibit small estimation errors with model improvements detected by an automated model reduction technique.}}, author = {{Götte, Ricarda-Samantha and Timmermann, Julia}}, booktitle = {{IFAC-PapersOnLine}}, keywords = {{joint estimation, unscented Kalman filter, sparsity, Laplacian prior, regularized horseshoe, principal component analysis}}, location = {{Yokohama, Japan}}, number = {{2}}, pages = {{869--874}}, title = {{{Approximating a Laplacian Prior for Joint State and Model Estimation within an UKF}}}, volume = {{56}}, year = {{2023}}, } @inproceedings{48482, author = {{Götte, Ricarda-Samantha and Klusmann, Jo Noel and Timmermann, Julia}}, booktitle = {{Proceedings - 33. Workshop Computational Intelligence: Berlin, 23.-24. November 2023}}, location = {{Berlin, Germany}}, pages = {{113--123}}, title = {{{Data-driven identification of disturbances using a sliding mode observer}}}, doi = {{10.5445/KSP/1000162754}}, year = {{2023}}, } @inproceedings{48476, author = {{Hesse, Michael and Timmermann, Julia and Trächtler, Ansgar}}, booktitle = {{2023 European Control Conference (ECC)}}, publisher = {{IEEE}}, title = {{{Hybrid Optimal Control for Dynamical Systems using Gaussian Process Regression and Unscented Transform*}}}, doi = {{10.23919/ecc57647.2023.10178368}}, year = {{2023}}, }