07 Fakultät Konstruktions-, Produktions- und Fahrzeugtechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/8
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Item Open Access Walking without impacts as a motion/force control problem(1992) Blajer, Wojciech; Schiehlen, WernerThe paper deals with the synthesis of control for impactless bipedal walking. In order of avoid impulses, both the specified motion of the biped and its ground reactions are controlled, yielding a combined motion and force control problem. A method for modeling and solving such problems is proposed. and then illustrated by the example of an impactless planar walk of a seven-link bipedal robot. Some numerical results of the motion simulation are reported.Item Open Access A combined distance and surface profile measurement system for industrial applications : a european project(1994) Docchio, Franco; Perini, Umberto; Tiziani, Hans J.The paper reports the design, development and characterization of an electrooptical equipment suitable for distance measurements and three-dimensional gauging of surfaces of industrial interest. The equipment comprises a dual-wavelength heterodyne interferometer for absolute distance measurements with a range of 20 m and an accuracy of 0.1 mm, that is integrated with a macroscopic scale, adaptive profilometer for threedimensional measurement of the shape to 1 mm. The performance of the equipment is well suited for effective operation in industrial metrology. The equipment has been developed by three partners, namely the Dipartimento di Elettronica per I’Automarione of the University of Brescia, the Sezione Diagnostica Elettroottica of ClSE, Milan, and the lnstitut for technische Optik of the University of Stuttgart, in the framework of a European Project partially funded by the Community Bureau of Reference.Item Open Access Robust Design Methodology for the development of commercial vehicle braking systems(2015) Kemmler, Stefan; Leopold, Tobias; Fricke, Jens; Bertsche, BerndToday’s product requirements demand an ever increasing functionality for the same space and usually the same number of components. Thereby, the quality, reliability and robustness of these products should be preserved or even be increased. This target conflict cannot be solved without compromises. The research community between the Institute of Machine Components (IMA), University of Stuttgart, and the Knorr-Bremse Systeme für Nutzfahrzeuge GmbH is seeking for new solutions for these challenges. The new approaches for designing robust and reliable products are being implemented directly in a current development project of an innovative Air Disc Brake (ADB). With “Systematic Method for Axiomatic Robustness-Testing” (SMART), reliability methods and the basic concept of Robust Design methodology are related to the Taguchi Method. SMART is based on three phases: System, Parameter and Tolerance Design; accordingly, the sample phases of VDA (Association of German Automotives) are used as milestones. In the System Design, SMART focuses on the decreasing complexity according to the functional dependences of the DPs, thus precluding early random failures. In the Parameter Design phase, SMART gives the developer an approach for modeling an adaptive simulation model (SIM-SMART). This model also enables the simulation of random and possible fatigue failures in addition to the nominally robust DPs. In the early stage of product development, reliability predictions are possible. In the iterative Tolerance Design phase, the final tolerance limits for robust and reliable products are defined with consideration of compromises in terms of costs, quality and technical feasibility. With the application of SMART, a design concept of a new generation of an ADB with less complexity is created. The extensive functions for flexible function studies are modeled with the objective of SIM-SMART. Accordingly to this model, parameter studies for determination of the nominal adjustment levels can be performed and their random and fatigue failures modeled. In conclusion, more accurate reliability test strategies are recommended using the definition of tolerance limits. The cost aspect and technical feasibility are also taken into account. So far, SMART has not been added to the iterative Tolerance Design phase. With this paper, the method is not only extended to this phase, but also sufficiently validated. In addition, SMART can predict and analyze random failures. With its three coherent and iterative phases, it is an as yet unpublished and unimplemented approach for designing even more robust and reliable products. Robust Design Methodology and reliability methods are fundamental building blocks for products with high quality requirements. SMART presents an approach to support the designing of robust, reliable, highly functional and innovative ADB.Item Open Access Phase shifting in an oblique incidence interferometer(1991) Boebel, Doris; Packroß, Bernd; Tiziani, Hans J.The evaluation of the interference pattern of a prism interferometer by a phase-stepping technique is described. The required phase shift is achieved by moving the surface under test perpendicular to the hypotenuse of the prism. Limits of this phase-shifting technique are discussed. A calibration method of the phase shift between the interferograms for the adjustable sensitivity of the interferometer is shown. Finally measurements of technical surfaces are presented.Item Open Access Mathematical modeling of signal transduction pathways in mammalian cells at the example of the EGF induced MAP kinase cascade and TNF receptor crosstalk(2004) Schoeberl, Birgit; Gilles, Ernst Dieter (Prof. Dr.-Ing. Dr. h.c. mult.)In this work we apply mathematical modeling to signal transduction networks in mammalian cells. In particular, we have developed models for a survival pathway, the EGF induced MAP kinase cascade and an apoptotic signal trans-duction network the TNF receptor crosstalk. The models presented here are based on and were validated with own experimental data. In the field of signal transduction the major proteins involved and their interactions are fairly well known and biochemically characterized . One characteristic of signal transduction networks is that they are highly interconected by positive and negative feedbacks. Therefore, the dynamics of these networks can not be understood by intuition alone. Mathematical modeling has proven to be a valuable tool in engineering that deals effectively with complexity. In both casese were able to verify hypotheses, which were obtained by the models, experimentally. This work shows that mathematical modeling in combination with quantitative experimental data can give new insights into the potential mechanisms of intracellular signal transduction and regulation.Item Open Access Optimierung des Fahrverhaltens(1992) Langenbeck, Bernhard; Leister, Günter; Schiehlen, Werner; Kutzbach, Heinz-DieterDas Fahrverhalten von Traktoren wird durch eine Vielzahl von Konstruktionsparametern bestimmt. Durch gegenseitige Abhängigkeiten der Parameter gestaltet sich die Suche nach einer geeigneten Parameterkombination aufwendig. Ein Verfahren zur Optimierung von mechanischen Systemen, die durch Mehrkörpermodelle beschrieben werden können, wird auf das Fahrverhalten eines Traktors angewendet.Item Open Access Yb:CaF2 thin-disk laser(2014) Wentsch, Katrin Sarah; Weichelt, Birgit; Günster, Stefan; Druon, Frederic; Georges, Patrick; Abdou Ahmed, Marwan; Graf, ThomasWe present Ytterbium-doped CaF2 as a laser active material with good prospects for high-power operation in thin-disk laser configuration owing to its favorable thermal properties. Thanks to its broad emission bandwidth the material is also suitable for the generation of ultra-short pulses. The properties of the crystal as well as the challenges related to the coating, polishing, mounting and handling processes which are essential to achieve high power laser oscillation in thin-disk configuration are discussed. A wavelength tunability of 92 nm is demonstrated, which confirms the potential of Yb:CaF2 for the generation of ultra-short pulses. An output power of 250 W with an optical efficiency of ηopt = 47% was measured in CW multimode thin-disk laser operation with a pump spot diameter of 3.6 mm. Using a smaller pump spot diameter of 1 mm the fundamental mode output power was 13 W with an optical efficiency of ηopt = 34%.Item Open Access Berührungsloses Meßverfahren zur Beurteilung der Struktur bearbeiteter Holzoberflächen(1991) Heisel, Uwe; Tröger, Johannes; Fischer, Andreas; Steinhoff, RalfDie Beurteilung der Struktur bearbeiteter Oberflächen von Holz und Holzwerkstolfen ist meßtechnisch eine anspruchsvolle Aufgabenstellung. So ist bei mechanisch abtastenden Verfahren die Größe des Radius der Tastspitze und deren Kegelform ein entscheidender begrenzender Faktor dafür, welche Feinheiten der abgetasteten Oberfläche noch erlaßt werden können. Beispielsweise sind offene angeschnittene Poren kaum darstellbar bzw. von anderen "Oberflächenfehlern" schwer zu unterscheiden. Ebenso spielt die Auflagekraft der Tastspitze eine das Meßergebnis beeinflussende Rolle, da es gegebenenfalls zu Deformationen oder Zerstörung der empfindlichen Zellstruktur der Oberfläche kommen kann. Ferner erlauben Tastschnittgeräte im allgemeinen nur ein linienförmiges Abtasten der Holzoberfläche. Eine Darstellung der räumlichen Struktur der zu beurteilenden Oberfläche ist nur mit erheblichen Zeitaufwand möglich. Der Firma UBM aus Ettlingen ist es gelungen, ein Meßverfahren für höchste Ansprüche zu entwickeln, das auf einem berührungslosen Meßprinzip beruht.Item Open Access Chemical process control : present status and future needs ; the view from European industry(1991) Schuler, Hans; Allgöwer, Frank; Gilles, Ernst DieterNot only in Europe, chemical process control is characterized by a broad invasion of distributed control systems into chemical plants. The information integration from process control up to business management is a great challenge of today which follows from the overall computerization of production. Most of the recent progress in process automation results from the application of computer science paradigms to control systems, and of advanced developments in field instrumentation. Despite these advances and the considerable progress made in process control theory, there is only limited acceptance and application of modern advanced process control methodologies in industrial practice. This paper is an attempt to summarize the European discussion on the reasons for these facts.Item Open Access DAMOS-C ein neutrales Datenformat zur standardisierten Anbindung von MKS an Simulationssysteme mit offener Systemarchitektur(1994) Thomson, Bernd; Neerpasch, Uwe; Schiehlen, WernerDer Arbeitskreis "Simulation der Systemdynamik des Fahrzeuges in der deutschen Automobilindustrie" der Firmen AUDI, BMW, MB/DB, Porsche und VW hat ein Simulationskonzept mit weitgehend offener Systemarchitektur zur Behandlung dynamischer Vorgänge im Fahrzeug erarbeitet. Grundgedanke dabei war, ein flexibles und sehr allgemein für alle Fragestellungen im Bereich mechatronischer Systeme einsetzbares Simulationswerkzeug auf Basis voneinander unabhängiger, kommerziell verfügbarer Software-Bausteine zur rechnergestützten Modellbildung mechanischer, hydraulischer und elektronischer Teilsysteme standardmäßig verfügbar zu machen. Im vorliegenden Beitrag wird am Beispiel einer prototypischen Integration der MKS-Modellerstellungssoftware, auf Basis einer im OFG-5chwerpunktprogramm "Dynamik von Mehrkörpersystemen (MKS)" entwickelten Datenkapsel DAMOS-C, die grundlegende Funktionalität dieser Vorgehensweise vorgestellt.