TY - JOUR A1 - Zillmer, M. A1 - Karlinger, Peter A1 - Zentgraf, Peter A1 - Würtele, M. A1 - Grimm, G. A1 - Wolf, W. T1 - Vorausschauende Zylindertemperierung BT - Modellprädiktive Regelung verkürzt den Aufheizvorgang und erhöht die Energieeffizienz JF - Kunststoffe KW - Modellprädikative Regelung KW - Aufheizvorgang Y1 - 2016 IS - 10/2016 ER - TY - CHAP A1 - Zenz, Vitus A1 - Muscat, Dirk A1 - Strübbe, Nicole T1 - Development of a new granulate feeding system for gas pressurized extrusion processes T2 - ANTEC 2023 N2 - One major problem of a continuous process like plastic extrusion is their incapability to deal with non-local gas pressure. This is an inherent problem because a continuous process has an open end in the feeding port where pressure can escape. In this study a novel feeding system was developed to enable granulate feeding into gas pressurized processes inside a single- or twin-screw extruder. With this apparatus gas pressure can be applied inside the extrusion process. The apparatus separates the pressurized extruder from the dosing equipment that feeds the extruder. It keeps the pressure inside the system while continuously feeding new material into the process. A small-scale prototype was designed for proof-of concept. The small size of the prototype was able to handle small amounts of granulates of around 100 - 200 g/h. An applied gas pressure of 8 bar was achieved. In future optimizations, throughput can be increased and maximum applied gas pressure towards 15-20 bar. KW - Plastic feeding KW - Granulate KW - Extrusion KW - Compounding KW - Reactive Extrusion Y1 - 2023 PB - SPE ANTEC ER - TY - JOUR A1 - Zenz, Vitus A1 - Muscat, Dirk A1 - Strübbe, Nicole T1 - So wird Bernsteinsäure aus Holzreststoffen gewonnen JF - Plastverarbeiter N2 - Die effiziente Umwandlung von lignocellulosehaltiger Biomasse wie Restholz ist eine wissenschaftliche sowie technologische Herausforderung weltweit. Die Technische Hochschule Rosenheim entwickelt gemeinsam mit Partnern ein neues Verfahren zur Herstellung von Bernsteinsäure aus Holzreststoffen. KW - Bernsteinsäure KW - Reaktive Extrusion Y1 - 2023 VL - 2023 IS - 04 SP - 22 EP - 25 PB - Hüthig GmbH CY - Heidelberg ER - TY - CHAP A1 - Zentgraf, Peter A1 - Reggio, D. T1 - MAGNETIC RATE DAMPING FOR SATELLITES IN LEO T2 - 32nd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE N2 - This article deals with the topic of damping the rates of a satellite after separation from the launcher by sensing the rates with magnetometers or gyroscopes and actually damping it with torquerods or thrusters. In literature problems of this kind are treated by linearization which is not adequate here due to the high nonlinearity of the problem caused by the high gyroscopic torque. This paper addresses the observability and controllability of the rate dynamics for symmetric satellite bodies. Furthermore, robust stability of any bodies is investigated by means of the Krasovskii–LaSalle principle which is a variant of Ljapunov’s Second Method. It is found that – apart from one exception - the system is robustly stable for certain conditions depending only on the gain matrix and not depending on the orbit, moments of inertia or initial conditions. The exception is that of the intuitive case of an equator type orbit, in which the satellite rotates around the magnetic field lines, in this case the satellite’s rate cannot be damped. Several design configurations are analysed with respect to their performance and cost: Rate damping with magnetometers or gyroscopes as sensors, and torquerods and thrusters as actuators. The results are evaluated with respect to the time to reach the desired rate, the propellant and the power equivalent battery mass used. The goal is to use the results to allow an AOCS equipment and architecture trade-off at an early project phase. The design of the rate damping control of the SWARM project is presented as an example and demonstrated with simulations. KW - Magnetic Rate Damping KW - Satellites KW - symmetric satellite bodies Y1 - 2018 ER - TY - JOUR A1 - Zentgraf, Peter A1 - Huber, Michaela T1 - Störgrößenkompensation in geregelten Systemen - Eine einfache Methode T1 - Compensating for disturbances in control systems - Demonstrating the practical benefits of a simple method JF - atp magazin N2 - Ein gutes Modell der Regelstrecke erhöht die Erfolgsaussicht, eine in der Simulation gut funktionierende Regelung in der Praxis genauso gut betreiben zu können. Gute Modelle eröffnen auch noch weitere Perspektiven: Sind die störenden Einflüsse auf den Regelkreis, die Störgrößen, die Messfehler und die Ungenauigkeiten im Simulationsmodell insgesamt kleiner als die Genauigkeitsanforderungen an die Regelgröße, dann kann man durch entsprechende Filterung des Eingangssignals sogar auf eine Rückführung der Regelgröße sogar verzichten. Andernfalls lassen sich deren Auswirkung auf die Regelgröße durch eine Rückführung verkleinern. Der Prozess kann für schnelle und hochgenaue Anwendungen durch die vorgestellte Methode weiter verbessert werden, wenn die störenden Einflüsse auf den Regelkreis direkt geschätzt und gleich kompensiert werden, bevor sie sich in der Regelgröße bemerkbar machen können. N2 - Control design engineers prefer precise models of a plant because these increase the chances to successfully transfer the design from simulation to reality. Furthermore, if the influence of disturbances, the noise content of the signals, and the model inaccuracy are small enough, then an open loop control might be sufficient. Otherwise, a feedback control loop is required to reduce the impact of the disturbances on the controlled variable. Using the method presented here, the time needed to reduce the impact during the process can be shortened significantly by directly estimating and compensating for the effects caused by disturbances and noise before these become noticeable in the controlled variable. KW - Regelstrecke KW - Regelkreis Y1 - 2022 VL - 2022 IS - 04 ER - TY - GEN A1 - Zentgraf, Peter A1 - Erb, S. ED - Zentgraf, Peter T1 - IMPACT OF ELECTRIC PROPULSION UNCERTAINTY ON ORBIT PREDICTION N2 - This paper analyses the achievable performance of the orbit prediction for a geostationary satellite using clusters of electrical propulsion (EP) thrusters for station-keeping and a star tracker based attitude control system. The challenge in the orbit prediction is that the real electrical propulsion thrust is known with limited accuracy only. In combination with thrust pointing errors, these inaccuracies can accumulate to large orbit position errors during long low thrust burn arcs. The discrepancy between real and predicted satellite position is determined in terms of probability and as a worst case scenario. KW - Orbit prediction KW - Electric propulsion KW - Satellite position Y1 - 2018 ER - TY - JOUR A1 - Zentgraf, Peter A1 - Bernatzky, Andreas A1 - Hager, Ralf A1 - Heigl, Martin A1 - Huber, Michaela A1 - Vogl, Georg A1 - Wolf, Christopher A1 - Zeitler, Adrian T1 - Hagelnavigator RO-BERTA für ein Hagelabwehrflugzeug JF - CRISIS PREVENTION Das Fachmagazin für Gefahrenabwehr, Innere Sicherheit und Katastrophenhilfe KW - Hagel Y1 - 2021 VL - 2021 IS - 2 SP - 38 EP - 40 ER - TY - CHAP A1 - Zentgraf, Peter A1 - Berge, S. A1 - Chasset, C. A1 - Filippi, H. A1 - Gottzein, E. A1 - Gutiérrez-Cañas, I. A1 - Hartrampf, M. A1 - Krauss, P. A. A1 - Kuehl, C. A1 - Lübke- Ossenbeck, B. A1 - Mittnacht, M. A1 - Montenbruck, O. A1 - Müller, C. A1 - Rueda Boldo, P. A1 - Truffi, A. ED - American Astronautical Society, T1 - PREPARING THE GPS-EXPERIMENT FOR THE SMALL GEO MISSION T2 - 33rd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE N2 - This paper deals with the preparation of the Small GEO mission and the accommodation of a GPS receiver as an experiment. The expected benefits of using the GPS receiver for Small GEO are explained. The feasibility of using GPS for position determination is investigated by simulation using a MosaicGNSS receiver, which was stimulated by a Spirent RF signal generator. A procedure, how to evaluate flight data on ground is outlined. Success criteria of the experiment and the minimal size of the downlink stream required and reserved for the receiver TM are presented. KW - GPS KW - geosynchronous mission KW - Small GEO telecommunications satellite Y1 - 2018 ER - TY - CHAP A1 - Zentgraf, Peter T1 - ANALYTICAL ATTITUDE DETERMINATION FROM A SPECIFIC RATE PROFILE T2 - 40th ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE, Breckenridge, Colorado, USA N2 - The problem dealt with in this paper is the analytical determination of the attitude of a rigid body which undergoes a given rate profile. Usually the attitude is determined by solving the kinematic differential equation numerically. For long lasting movements the outcome can cost computation time plus encountered losses in accuracy, which can be disturbing especially in optimization problems. This contribution solves the kinematic differential equation for certain rate profiles exactly and compares the results in accuracy and computation time with the standard procedures. KW - Attitude determination KW - kinematic differential equation KW - satellites Y1 - 2017 ER - TY - CHAP A1 - Zentgraf, Peter T1 - Generieren einer Streckenübertragungsfunktion aus gemessenen Ein-/Ausgangsdaten T2 - AALE 2019 - 16. Fachkonferenz "Autonome und intelligente Systeme in der Automatisierungstechnik" 28.02.2019 - 01.03.2019 in Heilbronn, Deutschland N2 - Zur Lösung einer regelungstechnischen Entwurfsaufgabe benötigt man ein Simulationsmodell der Regelstrecke. Entweder benötigt man es, weil es die meisten Entwurfsverfahren zur Bestimmung der Reglerparameter als gegeben voraussetzen oder weil man das Verhalten des Regelkreises zur Verifikation des gewünschten Verhaltens gefahrlos simulieren möchte, bevor man den Regler in dem realen geschlossenen Regelkreis verwendet. Die Motivation zur Entwicklung des hier vorgestellten Verfahrens ist es, Bachelor-Studenten der Ingenieurswissenschaften aus dem höheren Semester, die zum ersten Mal mit Regelungstechnik in Berührung kommen, ein möglichst allgemein anwendbares Verfahren zur Bildung von Streckenübertragungsfunktionen an die Hand zu geben, das von der Theorie her vollständig transparent und allein mit dem aus der Mathematik bisher Gelernten „verstehbar“ für sie ist. Grundsätzlich gibt es zwei verschiedene Arten, ein Simulationsmodell der Regelstrecke zu gewinnen: Bei der physikalischen oder theoretischen Modellbildung werden physikalische Erhaltungssätze auf den idealisierten sprich vereinfachten technischen Vorgang angewendet und nach den gewählten Ein- bzw. Ausgangssignalen umgeformt. Diese Vorgehensweise kann sehr zeitaufwendig sein und hinzukommt, dass Parameter des Modells meist unbekannt sind. Bei der experimentellen Modellbildung geht man von einem gemessenen Ein- bzw. Ausgangssignal aus und gleicht über mehr oder weniger aufwändige Optimierungsverfahren die simulierte Antwort an die gemessene Antwort an. KW - Regelungstechnik Y1 - 2019 ER - TY - JOUR A1 - Zentgraf, Peter T1 - Ein neues Verfahren zur Modellierung linearer Systeme - Experimentelle Modellbildung mit Ein- und Ausgangsdaten T1 - A new method for modelling linear systems - Experimental modelling using input/output data JF - atp magazin N2 - Es wird ein Verfahren zum Simulieren von Vorgängen vorgestellt, das auf der Messung des Eingriffs in ein reales System und dessen gemessener Reaktion beruht. Das Verfahren ist vollständig transparent, denn die notwendigen theoretischen Voraussetzungen zum Verständnis des Verfahrens bestehen nur aus Lehrinhalten aus dem Bachelorstudium für Ingenieure: das Lösen linearer DGLs mit konstanten Koeffizienten, die Laplace-Transformation und die Methode der kleinsten Quadrate. Es kommt ohne nichtlineare Optimierer oder Iterationen aus, weil die Lösung in zwei analytischen Gleichungen ausgedrückt werden kann. Das Verfahren hat in der Praxis ein großes Einsatzspektrum, denn es ist auf stabile und instabile Systeme mit und ohne Dämpfung anwendbar. Für die Wahl des Eingangssignals gibt es keine Einschränkung und die Anfangsbedingungen können mitgeschätzt werden. Das Verfahren kann im offenen und im geschlossenen Regelkreis eingesetzt werden. N2 - A novel method is presented for simulating technical processes on the basis of measured reaction of a system excited by a known input signal. The method is fully transparent and involves only linear differential equations, Laplace transformations, and the least squares method. There is no need for a nonlinear optimizer or an algorithm requiring iterations, and the solutions can be expressed by two linear matrix equations. The method can be used for a wide range of practical applications because the initial conditions can also be estimated it is applicable for stable or unstable systems, for open or closed loop systems and for dynamic processes in progress. KW - Experimentelle Modellbildung KW - Simulation KW - Lineare DGL KW - Einfachheit KW - experiment-based modelling KW - simulation KW - linear differential equations KW - simplicity Y1 - 2019 VL - 2019 IS - 11/12 ER - TY - CHAP A1 - Zentgraf, Peter T1 - Non-Rest to non-Rest Reference Slews for Agile Imaging Satellites With LQ-minimized Angular Momentum T2 - AIAA SCITECH 2023 Forum N2 - This paper shows a full parametrization non-rest to non-rest slew maneuvers using polynomials. A new modelling formulation is developed which on one hand satisfies exactly the given boundary conditions as well as the kinematic differential equation of the rotating body exactly. The idea is to determine one part of the unknown coefficients by the kinematical boundary conditions and to use the other part as free design parameters to shape the dynamic in between the boundary conditions. In addition, a least squares problem is formulated in order to minimize the angular momentum of the slew. This approach allows optimal slew maneuvers as well as low computational need such that an onboard usage is possible. Y1 - 2023 U6 - https://doi.org/10.2514/6.2023-2173 ER - TY - CHAP A1 - Yilmaz, Tugce A1 - Mari, Jorge A1 - Asam, Johann A1 - Kirner, Michael A1 - List, Andreas A1 - Fantauzzo, Lucia A1 - Seliger, Norbert T1 - AC Cycling Testing of SiC MOSFET Power Module T2 - Proccedings International exhibition and conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management (PCIM 2025) N2 - This paper details the development of an accelerated AC cycling test bench for evaluating the aging mechanisms of SiC MOSFET power modules. Contrary to classical HTGS and DGS which only exercise gate source stresses the AC Cycler switched under high voltage and current. Operating for about 235 hours, the system maintained stable thermal conditions thanks to an integrated cooling system. Key precursors of aging, such as increases in threshold voltage and on-state resistance were identified using static characterization curve tracer before and after the test. Gate charge and Vdson were also measured on-line with specially developed gate drivers. KW - power module KW - SiC KW - power cycling testing KW - MOSFET Y1 - 2025 SN - 978-3-8007-6541-6 U6 - https://doi.org/10.30420/566541341 SP - 2562 EP - 2567 PB - VDE VERLAG GMBH CY - Berlin ER - TY - CHAP A1 - Yalamanchili, R. A1 - Schlee, S. A1 - Märkl, M. A1 - King, F. A. T1 - Enhanced Time-Optimal Filter-Based Point-to-Point Trajectory Generation with Vibration Suppression T2 - The 10th International Conference on Mechatronics and Robotics Engineering (ICMRE), Milan, Italy, 2024 KW - Vibration Suppression Y1 - 2024 ER - TY - CHAP A1 - Wolfgang, E. A1 - Lefranc, G. A1 - Seliger, Norbert A1 - Berg, H. A1 - Licht, T. T1 - Zuverlässige Leistungselektronik für die Automobiltechnik T2 - ETG-Tagung Bauelemente der Leistungselektronik und ihre Anwendungen KW - Power electronics Y1 - 2023 PB - ETG CY - Bad Nauheim ER - TY - CHAP A1 - Wolfgang, E A1 - Seliger, Norbert A1 - Lugert, G A1 - Riepl, T T1 - High-temperature power electronics: challenges and opportunities T2 - Proceedings of the 2nd International Conference on Integrated Power Systems (CIPS) Y1 - 2023 SP - 43 EP - 51 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Langhals, H. T1 - A method for sorting of plastics with an apparatus specific quantum efficiency approach T2 - 2019 IEEE Sensors Applications Symposium (SAS) N2 - Today, the automatic separation of polymers from each other in an industrial scale is an unsolved problem. In laboratory environments, two methods are known whereby plastic is sorted either by color or by fluorescence decay time measurements that require fast synchronization and thus expensive equipment. A simple and pragmatic process is proposed to separate plastics from each other: all fluorescent photons are counted in relation to the absorbed photons. A theoretical model and an experimental setup are built in order to determine an apparatus specific quantum efficiency. KW - polymer KW - plastic sorting KW - fluorescence KW - quantum efficiency Y1 - 2019 UR - https://ieeexplore.ieee.org/document/8706034 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Optical identification of car tire particles on soil using fluorescence lifetime imaging microscopy T2 - Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES), Technical Digest Series (Optica Publishing Group, 2022) N2 - Tire wear is one of the major contributors of environmental pollution by microplastic. FD-FLIM in combination with an image processing algorithm are successfully applied to detect tyre wear on soil. KW - Diode lasers KW - Fluorescence lifetime imaging KW - Image processing KW - Image processing algorithms KW - Phase modulation KW - Phase shift Y1 - 2022 U6 - https://doi.org/10.1364/ES.2022.ETu3H.3 SP - ETu3H.3 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Non-destructive evaluation of treated polyethylene terephthalate films by fluorescence lifetime imaging T2 - 2021 IEEE Sensors Applications Symposium (SAS) N2 - The fluorescence decay time allows to identify and distinguish polymers from each other. Three differently treated biaxially-oriented polyethylene terephthalate films are examined with two excitation wavelengths of 445 and 488nm. The fluorescence decay time is dependent of the treatment method of the films and is a means for identification. KW - polymer KW - polymer identification KW - fluorescence lifetime imaging KW - fluorescence KW - FD-FLIM Y1 - 2021 U6 - https://doi.org/10.1109/SAS51076.2021.9530008 SP - 1 EP - 5 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Investigation of the Impact of CaCO3 Concentrations on the Fluorescence Lifetime of Polypropylene T2 - 2022 Conference on Lasers and Electro-Optics (CLEO) N2 - The impact of fillers on the fluorescence lifetime of polymers is still unknown. Investigating polypropylene containing different CaCO 3 concentrations using FD-FLIM show an exponential increase in fluorescence lifetime proportional to the CaCO 3 density in polypropylene. KW - Fluorescence KW - Lasers and electrooptics KW - Plastics KW - Electrooptical waveguides Y1 - 2022 SP - 1 EP - 2 ER -