Now showing 1 - 10 of 18
  • Publication
    Complementary research and education opportunities - a comparison of learning factory facilities and methodologies at TU Wien and MTA SZTAKI
    ( 2016)
    Kemeny, Zsolt
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    Nacsa, János
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    Erdos, Gábor
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    Glawar, Robert
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    Sihn, Wilfried
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    Monostori, László
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    Ilie-Zudor, Elisabeth
    Typical learning factories are characterized by selective simplification or scaling-down of complex and large-scale production processes, while also safely containing risks in the case of process failures inherent to experimental and didactic activities. The variety of aspects preserved by these scaled-down environments allow different approaches to be taken in research and education. The paper compares two facilities, at TU Wien and at MTA SZTAKI in Budapest, respectively, and highlights differences in their modes of operation, the resulting variations of course-based vs. project-based didactic approaches, as well as their place in technical higher education.
  • Publication
    Robotisiertes Laser-Fernschweißen
    ( 2016)
    Monostori, László
    Das Ziel des Projekts ist die Verbesserung der Bearbeitungsgeschwindigkeit, die Erhöhung der Prozessflexibilität und der Energieeffizienz. Zudem sollen die realen und virtuellen Prozesse verknüpft werden, um eine Remote-Offline-Programmierung zu ermöglichen.
  • Publication
    Cyber-physical systems in manufacturing
    ( 2016)
    Monostori, László
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    Kádár, Botond
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    Kondoh, Shinsuke
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    Kumara, Soundar R.
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    Reinhart, Gunther
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    Schuh, Günther
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    Sihn, Wilfried
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    Ueda, Kanji
    One of the most significant advances in the development of computer science, information and communication technologies is represented by the cyber-physical systems (CPS). They are systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-accessing and data-processing services available on the Internet. Cyber-physical production systems (CPPS), relying on the latest, and the foreseeable further developments of computer science, information and communication technologies on one hand, and of manufacturing science and technology, on the other, may lead to the 4th industrial revolution, frequently noted as Industrie 4.0. The paper underlines that there are significant roots in general - and in particular to the CIRP community - which point towards CPPS. Expectations towards research in and implementation of CPS and CPPS are outlined and some case studies are introduced. Related new R&D challenges are highlighted.
  • Publication
    A holistic approach for quality oriented maintenance planning supported by data mining methods
    ( 2016)
    Glawar, Robert
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    Kemeny, Zsolt
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    Nemeth, Tanja
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    Matyas, Kurt
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    Monostori, László
    ;
    Sihn, Wilfried
    Appropriate maintenance measures, which are carried out at the right time are a key factor to secure plant availability, product quality and process efficiency in modern manufacturing systems. Established maintenance strategies oftentimes lack in combining these strongly related aspects. They are not capable to anticipate in a holistic way and therefore lead to unnecessarily high maintenance efforts, wasted resources and the occurrence of quality and availability impairments. In order to realize a holistic and anticipatory approach for maintenance planning, a methodology which consistently compiles and correlates various data via ""cause and effect"" coherences is depicted. By breaking down the production facilities on component level a basis is set to link condition monitoring data, wear data, quality and production data by using data mining methods. This framework enables the identification of maintenance-critical conditions and the prediction of failure moments and quality deviations.
  • Publication
    An inverse economic lot-sizing approach to eliciting supplier cost parameters
    ( 2014)
    Egri, Péter
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    Kis, Tamás
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    Kovács, András
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    Váncza, József
    Recent literature on supply chain coordination offers a wide range of game theoretic and optimization approaches that ensure efficient planning in the supply chain, but assume that the involved parties have complete information about each other. However, in reality, complete information is rarely available, and those models alone do not present any incentive for the parties to reveal their private information, e.g., the cost parameters that they use when solving their planning problems. This paper proposes an inverse lot-sizing model for eliciting the cost parameters of a supplier from historic demand vs. optimal delivery lot-size pairs, gathered during repeated earlier encounters. It is assumed that the supplier solves a single-item, multi-period, uncapacitated lot-sizing problem with backlogs to optimality to calculate its lot-sizes, and the buyer is aware of this fact. The inverse lot-sizing problem is reformulated to an inverse shortest path problem, which is, in tu rn, solved as a linear program. This model is used to compute the ratios of the supplier's cost parameters, i.e., the setup, the holding, and the backlog cost parameters consistent with all the historic samples. The elicited cost parameters can be used as input for various game theoretic or bilevel optimization models for supply chain coordination. Computational experiments on randomly generated problem instances indicate that the approach is very efficient in predicting future supplier actions from the historic records.
  • Publication
    Capacity management for assembly systems with dedicated and reconfigurable resources
    ( 2014)
    Gyulai, Dávid
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    Kádár, Botond
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    Kovács, András
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    Monostori, László
    Managing changes and disturbances resulted by fluctuating order streams and diverse product portfolios requires efficient capacity management decisions and production planning strategies. High volume products can be produced cost efficiently on dedicated assembly lines, while the assembly of low runners is more efficient on reconfigurable lines. In the paper a hierarchical planning decision workflow is introduced to assign the products to dedicated and reconfigurable lines, and to optimize the system configuration and the production plan of the reconfigurable system in an integrated way. The proposed solution is demonstrated through the results of an industrial case study.
  • Publication
    Methodology and data-structure for a uniform system's specification in simulation projects
    ( 2013)
    Kardos, Csaba
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    Popovics, Gergely
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    Kádár, Botond
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    Monostori, László
    In the last few decades the evaluation and analysis of manufacturing systems' behavior and their performance became very important. Digital enterprise technologies, as for example discrete-event simulation (DES), are effective tools both in production related decision making processes and in structure and performance analysis of manufacturing systems. However, building a discrete-event based simulation model of a manufacturing system is a difficult task and requires special competence. The majority of simulation studies are aimed at analyzing a certain problem by a specific simulation model created by experts with a relatively high financial expenditure. The paper introduces an ongoing research aimed at developing a framework to reduce the efforts spent on draft simulation studies by simplifying and accelerating the process of model building. The proposed modeling methodology uses a uniform data structure which is a production oriented implementation of the ANSI/ISA-95 standard and supports the creation of models without simulation software specific knowledge. The supporting data structure enables the development and application of proprietary simulation engines tailored for specific problems. The paper compares the traditional and the proposed methodologies and also introduces the first experiments gained on specific test -cases. In our approach the simulation models are created automatically and independently from simulation tools which will be presented through the examples of both commercial and self-developed applications.
  • Publication
    Planning of remote laser welding processes
    ( 2013)
    Erdös, Gábor
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    Kemény, Zsolt
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    Kovács, András
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    Váncza, József
    The paper discusses the technical background of the remote laser welding (RLW) technology, its novel opportunities and implications for planning processes. Our ultimate goal is to develop a complete off-line programming toolbox for RLW which can provide an automated method for computing close-to-optimal robot programs. We suggest a workflow for the complete planning process, and propose new models and algorithms for solving the sequencing of welding tasks in conjunction with path planning, as well as for generating the inverse kinematics of the robot. The paper summarizes results of first computational experiments in an automotive case study using an industrial robot. The proposed method leads to a substantial reduction in the cycle time of the welding operation compared to an earlier approach.
  • Publication
    Complexity in engineering design and manufacturing
    ( 2012)
    ElMaraghy, Waguih
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    ElMaraghy, Hoda A.
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    Tomiyama, Tetsuo
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    Monostori, László
    This paper reviews the breadth of complexity of the design process, products, manufacturing, and business. Manufacturing is facing unprecedented challenges due to increased variety, market volatility and distributed global manufacturing. A fundamental residue of globalization and market uncertainty is the increasing complexity of manufacturing, technological and economic systems. The nature and sources of complexity in these areas are reviewed and complexity modeling and management approaches are discussed. Enterprises that can mitigate the negative aspects of complexity while managing its positives should thrive on the continuous change and increasing complexity. To reap these benefits in the future, manufacturing companies need to not only adopt flexible technical solutions but must also effectively innovate and manage complex socio-technical systems.
  • Publication
    Designing cooperation mechanisms for supply chains
    ( 2012)
    Váncza, József
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    Egri, Péter
    The paper defines generic requirements towards cooperative planning in the nucleus of any supply network that is constituted by a pair of autonomous manufacturer and supplier who possess asymmetric information on demand forecast and costs, respectively. Then a novel way is suggested for investigating this problem by means of the apparatus of mechanism design. The analysis results in some provable generic properties as for efficiency and truthfulness, and shows the impossibility of fair cost and profit sharing. Further on, design principles towards a payment scheme are devised that provide incentive for the partners to cooperate in order to minimize costs. This payment can be considered the price for a flexible supply service. As examples, the generic framework is instantiated with two particular cooperative supply mechanisms.