@article{ZengKellnerLienland2016, author = {Zeng, Li and Kellner, Florian and Lienland, Bernhard}, title = {Rucksackprobleme in der Praxis - schnelle Entscheidungen schwer gemacht}, series = {HMD - Praxis der Wirtschaftsinformatik}, volume = {53}, journal = {HMD - Praxis der Wirtschaftsinformatik}, number = {3}, doi = {10.1365/s40702-016-0207-z}, pages = {310 -- 322}, year = {2016}, abstract = {Unternehmen sind h{\"a}ufig mit Situationen konfrontiert, in denen schnell Entscheidungen bez{\"u}glich der Auswahl mehrerer Handlungsalternativen gefunden werden m{\"u}ssen. Mathematische Verfahren k{\"o}nnen hierbei unterst{\"u}tzen, z. B. f{\"u}r die Ermittlung einer ersten Diskussionsbasis. Verf{\"u}gbare Softwarel{\"o}sungen errechnen zwar h{\"a}ufig optimale Ergebnisse, zeigen jedoch Schw{\"a}chen bei der praktischen Anwendbarkeit. So ist eine Einarbeitung in komplexe Optimierungssoftware f{\"u}r die teilweise sporadisch auftretenden Probleme in der Regel f{\"u}r Unternehmen nicht m{\"o}glich, unter anderem auch unter Anbetracht der teilweise hohen Kosten der Standardsoftware und dem ben{\"o}tigten hohen Einarbeitungsaufwand. Gerade Problemstellungen in Fachbereichen, die nicht auf mathematische Probleml{\"o}sung spezialisiert sind, m{\"u}nden daher regelm{\"a}ßig in Ineffizienzen. Basierend auf den in der Literatur diskutierten L{\"o}sungsans{\"a}tzen wurde ein praxisorientierter Ansatz zur Entscheidungsunterst{\"u}tzung f{\"u}r Rucksackprobleme bzw. 0-1 Probleme mithilfe von Genetischen Algorithmen (GA) entwickelt und technisch in Microsoft Excel® umgesetzt. Ein Praxistest bei einem chinesischen Textilunternehmen belegt erh{\"o}hte Effektivit{\"a}t und Effizienz. Die Software kann kostenfrei nach MIT Lizenz unter http://www.solvega.de/ heruntergeladen werden.}, language = {de} } @inproceedings{ZengerSchmidtKroedel2013, author = {Zenger, A. and Schmidt, Jochen and Kr{\"o}del, M.}, title = {Towards the Intelligent Home: Using Reinforcement-Learning for Optimal Heating Control}, series = {Advances in Artificial Intelligence, Proceedings of the 36th Annual Conference on AI, volume 8077 of Lecture Notes in Artificial Intelligence}, booktitle = {Advances in Artificial Intelligence, Proceedings of the 36th Annual Conference on AI, volume 8077 of Lecture Notes in Artificial Intelligence}, publisher = {Springer}, year = {2013}, abstract = {We propose a reinforcement learning approach to heating control in home automation, that can acquire a set of rules enabling an agent to heat a room to the desired temperature at a defined time while conserving as much energy as possible. Experimental results are presented that show the feasibility of our method.}, language = {en} } @inproceedings{Zentgraf2017, author = {Zentgraf, Peter}, title = {ANALYTICAL ATTITUDE DETERMINATION FROM A SPECIFIC RATE PROFILE}, series = {40th ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE, Breckenridge, Colorado, USA}, booktitle = {40th ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE, Breckenridge, Colorado, USA}, year = {2017}, abstract = {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.}, language = {en} } @inproceedings{Zentgraf2019, author = {Zentgraf, Peter}, title = {Generieren einer Strecken{\"u}bertragungsfunktion aus gemessenen Ein-/Ausgangsdaten}, series = {AALE 2019 - 16. Fachkonferenz "Autonome und intelligente Systeme in der Automatisierungstechnik" 28.02.2019 - 01.03.2019 in Heilbronn, Deutschland}, booktitle = {AALE 2019 - 16. Fachkonferenz "Autonome und intelligente Systeme in der Automatisierungstechnik" 28.02.2019 - 01.03.2019 in Heilbronn, Deutschland}, year = {2019}, abstract = {Zur L{\"o}sung einer regelungstechnischen Entwurfsaufgabe ben{\"o}tigt man ein Simulationsmodell der Regelstrecke. Entweder ben{\"o}tigt man es, weil es die meisten Entwurfsverfahren zur Bestimmung der Reglerparameter als gegeben voraussetzen oder weil man das Verhalten des Regelkreises zur Verifikation des gew{\"u}nschten Verhaltens gefahrlos simulieren m{\"o}chte, 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 h{\"o}heren Semester, die zum ersten Mal mit Regelungstechnik in Ber{\"u}hrung kommen, ein m{\"o}glichst allgemein anwendbares Verfahren zur Bildung von Strecken{\"u}bertragungsfunktionen an die Hand zu geben, das von der Theorie her vollst{\"a}ndig transparent und allein mit dem aus der Mathematik bisher Gelernten „verstehbar" f{\"u}r sie ist. Grunds{\"a}tzlich gibt es zwei verschiedene Arten, ein Simulationsmodell der Regelstrecke zu gewinnen: Bei der physikalischen oder theoretischen Modellbildung werden physikalische Erhaltungss{\"a}tze auf den idealisierten sprich vereinfachten technischen Vorgang angewendet und nach den gew{\"a}hlten 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 {\"u}ber mehr oder weniger aufw{\"a}ndige Optimierungsverfahren die simulierte Antwort an die gemessene Antwort an.}, language = {de} } @article{Zentgraf2019, author = {Zentgraf, Peter}, title = {Ein neues Verfahren zur Modellierung linearer Systeme - Experimentelle Modellbildung mit Ein- und Ausgangsdaten}, series = {atp magazin}, volume = {2019}, journal = {atp magazin}, number = {11/12}, year = {2019}, abstract = {Es wird ein Verfahren zum Simulieren von Vorg{\"a}ngen vorgestellt, das auf der Messung des Eingriffs in ein reales System und dessen gemessener Reaktion beruht. Das Verfahren ist vollst{\"a}ndig transparent, denn die notwendigen theoretischen Voraussetzungen zum Verst{\"a}ndnis des Verfahrens bestehen nur aus Lehrinhalten aus dem Bachelorstudium f{\"u}r Ingenieure: das L{\"o}sen linearer DGLs mit konstanten Koeffizienten, die Laplace-Transformation und die Methode der kleinsten Quadrate. Es kommt ohne nichtlineare Optimierer oder Iterationen aus, weil die L{\"o}sung in zwei analytischen Gleichungen ausgedr{\"u}ckt werden kann. Das Verfahren hat in der Praxis ein großes Einsatzspektrum, denn es ist auf stabile und instabile Systeme mit und ohne D{\"a}mpfung anwendbar. F{\"u}r die Wahl des Eingangssignals gibt es keine Einschr{\"a}nkung und die Anfangsbedingungen k{\"o}nnen mitgesch{\"a}tzt werden. Das Verfahren kann im offenen und im geschlossenen Regelkreis eingesetzt werden.}, language = {de} } @inproceedings{Zentgraf2023, author = {Zentgraf, Peter}, title = {Non-Rest to non-Rest Reference Slews for Agile Imaging Satellites With LQ-minimized Angular Momentum}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, doi = {10.2514/6.2023-2173}, year = {2023}, abstract = {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.}, language = {en} } @inproceedings{ZentgrafBergeChassetetal.2010, author = {Zentgraf, Peter and Berge, S. and Chasset, C. and Filippi, H. and Gottzein, E. and Guti{\´e}rrez-Ca{\~n}as, I. and Hartrampf, M. and Krauss, P. A. and Kuehl, C. and L{\"u}bke- Ossenbeck, B. and Mittnacht, M. and Montenbruck, O. and M{\"u}ller, C. and Rueda Boldo, P. and Truffi, A.}, title = {PREPARING THE GPS-EXPERIMENT FOR THE SMALL GEO MISSION}, series = {33rd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE}, booktitle = {33rd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE}, editor = {American Astronautical Society,}, year = {2010}, abstract = {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.}, language = {en} } @inproceedings{ZentgrafBergeEdforsetal.2009, author = {Zentgraf, Peter and Berge, S. and Edfors, A. and Olsson, T. and Pionnier, G. and Bj{\"o}rk, M. and Chasset, C. and Nordeb{\"a}ck, T. and Rieschel, M. and L{\"u}bke- Ossenbeck, B.}, title = {Advanced AOCS Design on the First Small GEO Telecom Satellite}, series = {60th International Astronautical Congress, Oct. 12 -16, 2009, Daejon, South Korea}, booktitle = {60th International Astronautical Congress, Oct. 12 -16, 2009, Daejon, South Korea}, year = {2009}, abstract = {The advanced Attitude and Orbit Control System (AOCS) design of the Small GEO platform is now being adapted for the first commercial mission. The Small GEO telecommunications satellite is a new development to fill a niche in the telecom industry for small platforms weighing about 1.5 tonnes and targeting payloads of 300 kg and 3 kW. The first mission will launch into Geostationary Transfer Orbit (GTO). Small GEO is being developed by a Consortium led by OHBSystem AG. The Swedish Space Corporation is a partner in the Consortium and supplies the AOCS and Electric Propulsion (EP) subsystems. The project is currently in Phase C and the first mission will fly in 2012. This article gives an overview of the AOCS development status. The AOCS architecture is a three-axis stabilized system using reaction wheels for attitude control, star trackers for attitude determination, and EP for orbit control. The AOCS software is being developed using model-based design techniques and test driven development. Results from subsystem level testing of flight code will be presented. The AOCS design is characterized by a number of advances in technology beyond traditional telecom satellite designs. Perhaps the largest deviation from a traditional design is complete reliance on EP for orbit control. Angular momentum management of the reaction wheels relies solely upon EP in the nominal modes. The EP is not used in the safe modes and therefore a cold gas system is included On-board. The cold gas system uses Xenon, the same fuel used by the EP. Another advance is the reliance upon APS-based star trackers. APS (Active Pixel Sensor) star trackers have a number of advantages over their CCD-based cousins in terms of robustness. The traditional fine sun sensor is simplified to a fault tolerant system of solar cells giving low, but more than adequate, accuracy. In addition, a GPS sensor will be flown on-board as an experiment.}, language = {en} } @article{ZentgrafBernatzkyHageretal.2021, author = {Zentgraf, Peter and Bernatzky, Andreas and Hager, Ralf and Heigl, Martin and Huber, Michaela and Vogl, Georg and Wolf, Christopher and Zeitler, Adrian}, title = {Hagelnavigator RO-BERTA f{\"u}r ein Hagelabwehrflugzeug}, series = {CRISIS PREVENTION Das Fachmagazin f{\"u}r Gefahrenabwehr, Innere Sicherheit und Katastrophenhilfe}, volume = {2021}, journal = {CRISIS PREVENTION Das Fachmagazin f{\"u}r Gefahrenabwehr, Innere Sicherheit und Katastrophenhilfe}, number = {2}, pages = {38 -- 40}, year = {2021}, language = {de} } @misc{ZentgrafErb2009, author = {Zentgraf, Peter and Erb, S.}, title = {IMPACT OF ELECTRIC PROPULSION UNCERTAINTY ON ORBIT PREDICTION}, editor = {Zentgraf, Peter}, year = {2009}, abstract = {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.}, language = {en} } @article{ZentgrafHuber2022, author = {Zentgraf, Peter and Huber, Michaela}, title = {St{\"o}rgr{\"o}ßenkompensation in geregelten Systemen - Eine einfache Methode}, series = {atp magazin}, volume = {2022}, journal = {atp magazin}, number = {04}, year = {2022}, abstract = {Ein gutes Modell der Regelstrecke erh{\"o}ht die Erfolgsaussicht, eine in der Simulation gut funktionierende Regelung in der Praxis genauso gut betreiben zu k{\"o}nnen. Gute Modelle er{\"o}ffnen auch noch weitere Perspektiven: Sind die st{\"o}renden Einfl{\"u}sse auf den Regelkreis, die St{\"o}rgr{\"o}ßen, die Messfehler und die Ungenauigkeiten im Simulationsmodell insgesamt kleiner als die Genauigkeitsanforderungen an die Regelgr{\"o}ße, dann kann man durch entsprechende Filterung des Eingangssignals sogar auf eine R{\"u}ckf{\"u}hrung der Regelgr{\"o}ße sogar verzichten. Andernfalls lassen sich deren Auswirkung auf die Regelgr{\"o}ße durch eine R{\"u}ckf{\"u}hrung verkleinern. Der Prozess kann f{\"u}r schnelle und hochgenaue Anwendungen durch die vorgestellte Methode weiter verbessert werden, wenn die st{\"o}renden Einfl{\"u}sse auf den Regelkreis direkt gesch{\"a}tzt und gleich kompensiert werden, bevor sie sich in der Regelgr{\"o}ße bemerkbar machen k{\"o}nnen.}, language = {de} } @inproceedings{ZentgrafReggio2009, author = {Zentgraf, Peter and Reggio, D.}, title = {MAGNETIC RATE DAMPING FOR SATELLITES IN LEO}, series = {32nd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE}, booktitle = {32nd ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE}, year = {2009}, abstract = {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.}, language = {en} } @inproceedings{ZenzMuscatStruebbe2023, author = {Zenz, Vitus and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Development of a new granulate feeding system for gas pressurized extrusion processes}, series = {ANTEC 2023}, booktitle = {ANTEC 2023}, publisher = {SPE ANTEC}, year = {2023}, abstract = {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.}, language = {en} } @article{ZenzMuscatStruebbe2023, author = {Zenz, Vitus and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {So wird Bernsteins{\"a}ure aus Holzreststoffen gewonnen}, series = {Plastverarbeiter}, volume = {2023}, journal = {Plastverarbeiter}, number = {04}, publisher = {H{\"u}thig GmbH}, address = {Heidelberg}, pages = {22 -- 25}, year = {2023}, abstract = {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 Bernsteins{\"a}ure aus Holzreststoffen.}, language = {de} } @article{ZieglerSpindler1993, author = {Ziegler, Felix and Spindler, Uli}, title = {An ammonia refrigerator with an absorption circuit as economizer}, series = {International Journal of Refrigeration}, journal = {International Journal of Refrigeration}, number = {7/93}, pages = {230 -- 239}, year = {1993}, language = {en} } @article{ZillmerKarlingerZentgrafetal.2016, author = {Zillmer, M. and Karlinger, Peter and Zentgraf, Peter and W{\"u}rtele, M. and Grimm, G. and Wolf, W.}, title = {Vorausschauende Zylindertemperierung}, series = {Kunststoffe}, journal = {Kunststoffe}, number = {10/2016}, year = {2016}, language = {de} } @book{ZimmermannBeneken2000, author = {Zimmermann, J. and Beneken, Gerd}, title = {Verteilte Komponenten und Datenbankanbindung . Mehrstufige Architekturen mit SQLJ und Enterprise JavaBeansTM 2.0 (Allgemein: Datenbanken)}, publisher = {Addison-Wesley}, address = {M{\"u}nchen}, publisher = {Technische Hochschule Rosenheim}, year = {2000}, abstract = {Mehrstufige Architekturen mit SQLJ und Enterprise JavaBeans Datenbankanbindung und Erstellung von Komponenten sind ein essentieller Bestandteil von Java-Anwendungen. Bei Java-Schnittstellen r{\"u}ckt der neue ANSI-Standard SQLJ f{\"u}r relationale und objektrelationale Datenbanken immer mehr in den Blickpunkt. Bei mehrstufigen Architekturen ist dar{\"u}ber hinaus die Komponentenbildung unabdingbar, und dabei entwickelt sich EJB zu einem De-facto-Standard. Nach einer grundlegenden Einf{\"u}hrung geht es im zweiten Teil des Buches um Java-Schnittstellen zu Datenbanken: JDBC, ODMG und SQLJ8. Wie EJB-Komponenten erstellt werden und auf Java-Datenbanken zugreifen, wird im dritten Teil beschrieben.}, language = {de} } @inproceedings{ZinsserSchmidtNiemann2003, author = {Zinßer, T. and Schmidt, Jochen and Niemann, H.}, title = {Performance Analysis of Nearest Neighbor Algorithms for ICP Registration of 3-D Point Sets}, series = {Vision, Modeling, and Visualization 2003}, booktitle = {Vision, Modeling, and Visualization 2003}, year = {2003}, abstract = {There are many nearest neighbor algorithms tailor made for ICP,but most of them require Special input data like range Images or triangle meshes. We focus on efficient nearest neighbor algorithms that do not impose this limitation, and thus can also be used with 3-D point sets generated by structure-frommotion techniques. We shortly present the evaluated algorithms and introduce the modifications we made to improve their efficiency. In particular, several enhancements to the well-known k-D tree algorithm are described. The first part of our Performance Analysis consists of Experiments on synthetic point sets, whereas the second part features experiments with the ICP algorithm on real point sets. Both parts are completed by a thorough evaluation of the obtained results.}, language = {en} } @inproceedings{ZinsserSchmidtNiemann2003, author = {Zinßer, T. and Schmidt, Jochen and Niemann, H.}, title = {A Refined ICP Algorithm for Robust 3-D Correspondence Estimation}, series = {Proceedings of the IEEE International Conference on Image Processing, volume 2, pages 695-698, Barcelona, Spain}, booktitle = {Proceedings of the IEEE International Conference on Image Processing, volume 2, pages 695-698, Barcelona, Spain}, year = {2003}, abstract = {Robust registration of two 3-D point sets is a common problem in computer vision. The iterative closest point (ICP) algorithm is undoubtedly the most popular algorithm for solving this kind of problem. In this paper, we present the Picky ICP algorithm, which has been created by merging several extensions of the standard ICP algorithm, thus improving its robustness and computation time. Using pure 3-D point sets as input data, we do not consider additional information like point color or neighborhood relations. In addition to the standard ICP algorithm and the Picky ICP algorithm proposed in this paper, a robust algorithm due to Masuda and Yokoya and the RICP algorithm by Trucco et al. are evaluated. We have experimentally determined the basin of convergence, robustness to noise and outliers, and computation time of these four ICP based algorithms}, language = {en} } @inproceedings{ZinsslerSchmidtNiemann2005, author = {Zinßler, T. and Schmidt, Jochen and Niemann, H.}, title = {Point Set Registration with Integrated Scale Estimation}, series = {Proceedings of the Eighth International Conference on Pattern Recognition and Image Processing (PRIP 2005), pages 116-119, Minsk, Republic of Belarus}, booktitle = {Proceedings of the Eighth International Conference on Pattern Recognition and Image Processing (PRIP 2005), pages 116-119, Minsk, Republic of Belarus}, year = {2005}, abstract = {Wepresentaniterativeregistrationalgorithmfor aligning two differently scaled 3-D point sets. It extends the popular Iterative Closest Point (ICP) algorithm by estimating a scale factor between the two point sets in every iteration. The presented algorithm is especially useful for the registration of point sets generated by structure-frommotion algorithms, which only reconstruct the 3-D structure of a scene upto scale. LiketheoriginalICPalgorithm,thepresentedalgorithm requires a rough pre-alignment of the point sets. In order to determine the necessary accuracy of the pre-alignment, wehaveexperimentallyevaluatedthebasinofconvergence of the algorithm with respect to the initial rotation, translation, andscale factor between the two point sets.}, language = {en} }