Now showing 1 - 10 of 289
  • Publication
    Auf dem Weg zur Anwendung von Produktentstehungsmethoden
    ( 2010)
    Krause, F.-L.
    Obwohl es hinsichtlich der Produktentstehung eine Vielzahl von Forschungsergebnissen für die Rechneranwendung gibt, ist dieses Potenzial beim Stand der Technik nicht in die Entwicklung von Konstruktionsmethoden einbezogen worden. Zurückzuführen ist das vor allem auf Kommunikationsprobleme zwischen System- und Produktentwickler. Eine Lösung für diesen Umstand bieten Assistenzsysteme als Anwendungssysteme, die mit den Eigenschaften der Basissysteme arbeiten und dabei nur über eine begrenzte Menge von Eingabemöglichkeiten verfügen. Assistenzsysteme können für ein Produkt oder eine Produktgruppe ausgelegt werden. Fragestellungen, die bisher im Unternehmen nicht bearbeitet wurden, wie beispielsweise Ressourcenschonung oder Energieeffizienz können durch beauftragte Module Bestandteil der Bearbeitung und damit Teil der Lösung werden. Das Wissen der Produktentwickler kann für die Systementwicklung nutzbar gemacht werden, weil die Produktentwickler gleichzeitig die Systementwickler sind. Zur Erstellung des Anwendungsassistenzsystems sollten Produktentwickler Konfigurationsassistenzsysteme benutzten können. Konfigurationsassistenzsysteme sind auf den Kenntnisstand der Produktentwickler angepasste Systeme zur Generierung von Anwendungsassistenzsystemen. Für den Produktverantwortlichen stellt sich das Anwendungsassistenzsystem als ein Spezialsystem dar, das auf seine Aufgabe zugeschnitten ist. Trotz der gewollten Beschränkung können die Fähigkeiten des Systems äußerst komplex sein. Das in gleicher Weise aufgebaute Konfigurationsassistenzsystem sollte von Systemexperten entwickelt werden. Die Benutzerfreundlichkeit der Systeme wird dadurch erreicht, indem die Basissysteme nicht mit der Gesamtheit ihrer Funktionen zur Verfügung gestellt werden, sondern nur die im Kontext des Vorganges benötigten Funktionen wählbar sind. Die Vorgehensweise ist insgesamt auf die betreffenden Produkte bzw. Produktgruppen angepasst. Der Aufwand für die Konfiguration eines Anwendungsassistenzsystems lohnt sich immer dann, wenn im Sinne von Anpassungskonstruktionen die Aufgaben in ähnlicher Form wiederholend gestellt werden. In die Systeme können alle gewünschten Aufgaben aus dem Produktlebenszyklus einbezogen werden.
  • Publication
    Competing in engineering design - the role of virtual product creation
    ( 2010)
    Stark, R.
    ;
    Krause, F.-L.
    ;
    Kind, C.
    ;
    Rothenburg, U.
    ;
    Müller, P.
    ;
    Hayka, H.
    ;
    Stöckert, H.
    Product creation is facing the next level of fundamental changes. Global demands are growing substantially to achieve energy efficient and sustainable value creation networks for production, products and services without compromising traditional success factors such as time to market, cost and quality. To stay competitive within such an environment development partners in industry and public sectors will require new interplay solutions for engineering design execution, domain knowledge representation, expert competence utilization and digital assistance systems. This scenario offers the chance for virtual production creation solutions to become critical for the future by offering unique engineering capabilities, which have not yet been explored or deployed. The paper investigates key elements of modern Virtual Product Creation - such as agile process execution, functional product modeling and context appropriate information management - towards their competitive role in satisfying increasing numbers of product requirements, in delivering robust systems integration and in ensuring true sustainable product lifecycle solutions.
  • Publication
    Competing in engineering design - the role of virtual product creation
    ( 2009)
    Stark, R.
    ;
    Krause, F.-L.
    ;
    Kind, C.
    ;
    Rothenburg, U.
    ;
    Müller, P.
    ;
    Stöckert, H.
    Product creation is facing the next level of fundamental changes. Global demands are growing substantially to achieve energy efficient and sustainable value creation networks for products, production and services without compromising traditional success factors such as time to market, cost and quality. To stay competitive within such an environment development partners in industry and public sectors will require new interplay solutions for engineering design execution, domain knowledge representation, expert competence utilization and digital assistance systems. This scenario offers the chance for virtual production creation solutions to become critical for the future by offering unique engineering capabilities which have not yet explored or deployed. The paper investigates key elements of modern virtual product creation such as agile process execution, functional product modeling and context appropriate information management towards their competitive role in satisfying increasing numbers of product requirements, in delivering robust systems integration and in ensuring true sustainable product lifecycle solutions.
  • Publication
    Evolutionary optimization of mass-spring models
    ( 2009)
    Völlinger, U.
    ;
    Stier, H.
    ;
    Priesnitz, J.
    ;
    Krause, F.-L.
    With present available solutions the interactive simulation of flexible parts in Virtual Reality (VR) applications is still a problem. Due to missing possibilities for the physically correct representation of deformation characteristics the informative capability of such simulations is reduced clearly. Considering the deformation of flexible parts is advantageous for a lot of applications like dynamic assembly/disassembly simulations or essential for virtual surgery simulations. Discrete approaches for simulations like mass-spring models are computationally efficient and can handle large deformations. Therefore they are suitable for real-time simulations, hence often used in interactive deformation simulations. There are however a few drawbacks concerning this model. The behaviour of this model is dependent on mesh resolution and topology. The main problem is to find suitable parameters for the spring elements. There is no analytic solution for direct distribution of ma terial properties in triangle or tetrahedral meshes. One approach to address the problem of finding appropriate mesh parameters is to use learning algorithms like simulated annealing, genetic algorithms or neural networks. Our method to identify the spring constants and simultaneously optimize the topology of the mesh is based on evolutionary algorithms. On this behalf, we combined functions for estimation, selection, recombination, and mutation inspired by biological evolution, which we adopted on a set of initialized meshes. Our method is suitable for triangle and tetrahedral meshes. Physically plausible deformation behaviour can be obtained by the optimized models within a certain scope of load. Compared to reference deformations, the initial deviation can be reduced by approximately 90% applying the optimization process.
  • Publication
  • Publication
    Nachhaltigkeit durch virtuelle Produktentwicklung
    ( 2007)
    Krause, F.-L.
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    Hayka, H.
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    Kind, C.
    ;
    Rothenburg, U.
  • Publication
    Usability of hybrid, physical and virtual objects for basic manipulation tasks in virtual environments
    ( 2007)
    Krause, F.-L.
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    Israel, J.H.
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    Neumann, J.
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    Feldmann-Wüstefeld, T.
    Integrating physical and virtual environments has been shown to improve usability of virtual reality (VR) applications. Objects within these mixed realities (MR (Milgram and Kishino, 1994)) can be hybrid physical/virtual objects that are physically manipulatable and have flexible shape and texture. We compare usability of hybrid objects for basic manipulation tasks (rotation, positioning) to physical and virtual objects. The results suggest that hybrid objects are manipulated faster than virtual objects, but not more accurately. Physical objects outperform both hybrid and virtual objects in terms of speed and accuracy. On the other hand, users felt most stimulated by the virtual objects, followed by the hybrid and physical objects. The study shows that hybrid objects "work" in virtual environments, but further investigations regarding the factors influencing their usability are needed.
  • Publication
    Virtual product development as an engine for innovation
    ( 2007)
    Krause, F.-L.
    ;
    Jansen, H.
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    Kind, C.
    ;
    Rothenburg, U.
  • Publication
    Collaborative engineering
    ( 2007)
    Krause, F.-L.
    ;
    Hayka, H.
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    Langenberg, D.