Faunhofer Project Center for Production Management and Informatics PMI

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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.

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An inverse economic lot-sizing approach to eliciting supplier cost parameters

2014 , Egri, Péter , Kis, Tamás , Kovács, András , 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.

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Design and assessment of quality control loops for stable business processes

2012 , Schmitt, Robert , Monostori, László , Glöckner, Henrik , Viharos, Zsolt János

Due to their open and dynamic character, business processes in lack of adequate feedback mechanisms tend to become unstable in case of unanticipated disturbances or target adjustments. In order to face this challenge and to ensure entrepreneurial quality the implementation of quality control loops is proposed, whose design is derived from cybernetics. The paper discusses requirements for the characteristics of quality control loops and presents a new approach for their assessment implemented in software. The developed tool also serves as a knowledge exchange platform since it provides an opportunity for exchanging standardized control loop elements.

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Applying model-reconstruction by exploring MES and PLC data for simulation support of production systems

2012 , Pfeiffer, András , Kádár, Botond , Popovics, Gergely , Kardos, Csaba , Vén, Zoltán , Kemény, Lorinc , Monostori, László

The paper introduces a discrete-event simulation-based decision supporting system aiming at automatically mirroring the current state of a large-scale material handling system of a production system in a digital model and supporting the analysis of diverse control settings and rules. The discrete-event digital model is built in an automated way and all the data necessary for the model are taken from a manufacturing execution system (MES) and additionally directly from programmable logic controllers (PLC). Main focus is given to present the results of the PLC program code processing method (code mapping) generating a structured dataset, as well as the model-reconstruction method for the simulation software. The easy-of-use support tool is intended to be used both in planning and operation phases of an automotive manufacturing company, thus the capabilities of model reconstruction and simulation are tested on real-world data.

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Cyber-physical systems in manufacturing

2016 , Monostori, László , Kádár, Botond , Bauernhansl, Thomas , Kondoh, Shinsuke , Kumara, Soundar R. , Reinhart, Gunther , Sauer, Olaf , Schuh, Günther , Sihn, Wilfried , 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.

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Planning of remote laser welding processes

2013 , Erdös, Gábor , Kemény, Zsolt , Kovács, András , 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.

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Uniform Data Structure for Production Simulation

2012 , Popovics, Gergely , Kardos, Csaba , Kemény, Lorinc , Gyulai, Dávid , Monostori, László

One of the most widespread techniques to evaluate various aspects of a manufacturing system is discrete-event simulation (DES). However, building a simulation model of a manufacturing system is a difficult task and requires special competence. The majority of simulation studies aimed at analyzing a certain problem by a specific simulation model created by experts. This approach requires relatively high financial expenditures. The paper introduces an ongoing research aimed at developing an application to reduce the costs of a draft simulation study. The input of the simulation models in the proposed methodology is based on ISA-95 standardized data structure. The instantiated input data set can be stored both in MS Excel, XML files or an SQL database. Having the complete input a simulation model can be created automatically without simulation expertise.

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Capacity management for assembly systems with dedicated and reconfigurable resources

2014 , Gyulai, Dávid , Kádár, Botond , Kovács, András , 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.

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Methodology and data-structure for a uniform system's specification in simulation projects

2013 , Kardos, Csaba , Popovics, Gergely , Kádár, Botond , 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.

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Complexity in engineering design and manufacturing

2012 , ElMaraghy, Waguih , ElMaraghy, Hoda A. , Tomiyama, Tetsuo , 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.

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