Emulation of control strategies through machine learning in manufacturing simulations :
Abbildung von Steuerungslogiken durch maschinelles Lernen für die Simulation von Produktionssystemen. - In: Simulation in production and logistics 2015, (2015), S. 481-490
In the context of discrete-event simulation of production and logistics systems, modelling an exact representation of the real system is needed for obtaining sound and reliable results. The automatic generation of simulation models is an approach for saving time and effort for creating models and, therefore, it is a recurring issue in modelling methodology research. In automatic model generation, the approximation of dynamic behaviour is a challenging problem. This is for example the case when the dispatching and scheduling of production jobs needs to be adequately emulated, but the underlying rules are unknown. In previous work, we presented an approach for approximating dynamic behaviour through artificial neural networks. In this paper, we propose an improved approach and investigate its suitability again with artificial neuronal networks as well as with other data mining and supervised machine learning methods.
Knowledge discovery in manufacturing simulations. - In: SIGSIM PADS'15, ISBN 978-1-4503-3565-2, (2015), S. 3-12
Discrete event simulation studies in a manufacturing context are a powerful instrument when modeling and evaluating processes of various industries. Usually simulation experts conduct simulation experiments for a predetermined system specification by manually varying parameters through educated assumptions and according to a prior defined goal. Moreover, simulation experts try to reduce complexity and number of simulation runs by excluding parameters that they consider as not influential regarding the simulation project scope. On the other hand, today's world of big data technology enables us to handle huge amounts of data. We therefore investigate the potential benefits of designing large scale experiments with a much broader coverage of possible system behavior. In this paper, we propose an approach for applying data mining methods on simulation data in combination with suitable visualization methods in order to uncover relationships in model behavior to discover knowledge that otherwise would have remained hidden. For a prototypical demonstration we used a clustering algorithm to divide large amounts of simulation output datasets into groups of similar performance values and depict those groups through visualizations to conduct a visual investigation process of the simulation data.
Towards HLA-based optimistic synchronization with CSPs. - In: SIGSIM PADS'15, ISBN 978-1-4503-3565-2, (2015), S. 97-98
The High Level Architecture for Modeling and Simulation (HLA) comes with the promise of facilitating interoperability between a wide variety of simulation systems. HLA's time management offers a unique support for heterogeneous time advancement schemes and differentiates HLA from other general interoperability standards. While it has been shown that HLA is applicable for connecting commercial off-the-shelf simulation packages (CSPs), the usage of HLA time management in this specific application area is virtually always limited to conservative synchronization. In this paper, we investigate HLA's capabilities concerning optimistic synchronization and the imposed requirements on CSPs. For the first time, we outline its use in combination with a CSP, namely the Simulation Language with Extensibility (SLX). We report on initial performance results and potential limitations in the current HLA 1516.1-2010 standard and its interpretation by RTI vendors.
Automatic generation of route networks for microscopic traffic simulations. - In: Winter Simulation Conference (WSC), 2014, ISBN 978-1-4799-7487-0, (2014), S. 2848-2859
Microscopic traffic simulation is a well-accepted simulation approach for simulation problems where the effects of individual driver behavior and/or vehicle interactions need to be taken into account at a fairly detailed level. Such problems include the optimization of traffic light controls patterns or the design of lane layouts at intersections. Such simulation models typically require very detailed and accurate models of the underlying road networks. The manual creation of such networks constitutes a high effort, limiting the simulated area in practical applications to the absolutely necessary. With the increased availability of satellite based geographical data we investigate, if and how such data can be automatically transformed into route networks with adequate level of detail for microscopic traffic simulation models. We further outline the design of data structures for an extensible simulation framework for microscopic traffic simulation which is capable of including different types of publically available data sources.
http://dx.doi.org/10.1109/WSC.2014.7020126
Webbasierte Animation von Simulationsläufen auf Basis des Core Manufacturing Simulation Data (CMSD) Standards. - In: ASIM 2014, 22. Symposium Simulationstechnik, 3. bis 5. September 2014, HTW Berlin; Tagungsband, (2014), S. 63-70
Animation von Simulationsläufen ist für viele Anwendungen ein nicht zu unterschätzendes Hilfsmittel. Die Nutzungsmöglichkeiten sind hierbei mannigfaltig, sie reichen von der Validierung der Modelle bis hin zur Ergebnispräsentation von Simulationsstudien. Dem Nutzen steht mitunter aber auch ein nicht zu unterschätzender Aufwand gegenüber, gerade im Kontext der automatischen webbasierten Simulation sind oft geeignete Animationen nicht verfügbar. Im Rahmen dieses Papers wird ein Ansatz vorgestellt, welcher ein bestehendes Framework zur automatischen Modellgenerierung, -initialisierung und Simulationsdurchführung inklusive Ergebnisauswertung auf Basis des Core Manufacturing Simulation Data (CMSD) Standards um die Möglichkeit der vollständig automatischen webbasierten Animation erweitert. Hierzu wird neben der Diskussion der Grundlagen der Animation das bestehende Framework und der dem Framework zugrunde liegende CMSD-Standard vorgestellt. Des Weiteren werden verschiedene Implementierungstechnologien vom Streamen von Videos über das Nutzen von Plug-Ins wie Flash oder Java Applets bis hin zu modernen Techniken wie HTML 5, CSS3 und JavaScript kritisch beleuchtet. Abschließend wird eine prototypische Implementierung mittels HTML 5 Canvas und den JavaScript Frameworks JQuery und KineticJS vorgestellt.
Methoden zur teilautomatischen Generierung von Emulationsmodellen. - In: Simulation in Produktion und Logistik 2013, (2013), S. 741-750
Emulation models as the basis for virtual commissioning of control software and hardware are traditionally built manually and require a high amount of time and effort for building them. This paper addresses this issue by discussing different options for a semi-automatic generation of emulation models. We discuss different scenarios (from automatic emulation model generation to model transformation approaches) to and the associated benefits and requirements. Based on a comparison of the different scenarios, we discuss the economic efficiency and the applicability of all scenarios. Finally we present a prototypical implementation of a method for transforming a simulation model originally used for planning purposes into an emulation model used for virtual commissioning.
Using crowdsourced geographic information from OpenStreetMap for discrete event simulation of logistic systems. - In: 46th Annual Simulation Symposium (ANSS 2013), ISBN 978-1-62748-030-7, (2013), S. 11-18
This article investigates the usability of crowd sourced geographical information from systems such as OpenStreetMap (OSM) for logistic simulation. Our investigations are motivated by the need to efficiently and quickly build simulation models containing complex infrastructure elements such as streets, rails, waterways, and their junctions. We, therefore, discuss the representation of such data in geographical information systems as well as possible export and import mechanisms. We further suggest transformations of the exported data for facilitating its use for logistics simulation.We finally introduce a prototype based on OSM data of the Volkswagen AG plant in Wolfsburg (Germany) and report some performance results.
A new web based method for distribution of simulation experiments based on the CMSD standard. - In: Proceedings of the 2012 Winter Simulation Conference (WSC), ISBN 978-1-4673-4779-2, (2012), insges. 12 S.
This article introduces a novel methodology for web based distribution of simulation experiments. The approach is related to themes such as web based applications, cloud computing or applications as a service, which have been recurring topics in scientific papers for years. The methodology is based on automatic model generation, initialization, and result analysis under usage of the CMSD standard. All user interactions are performed in web based user interfaces. Of special importance is that different simulations tools can be used in parallel without any additional effort. Furthermore the simulation tool actually used is transparent to the user. The applicability of our methodology is demonstrated for different production scenarios.
http://dx.doi.org/10.1109/WSC.2012.6464985
Model generation in SLX using CMSD and XML stylesheet transformations. - In: Proceedings of the 2012 Winter Simulation Conference (WSC), ISBN 978-1-4673-4779-2, (2012), insges. 11 S.
This article introduces a novel methodology for automatic simulation model generation. The methodology is based on the usage of XML stylesheet transformations for generating the actual source code of the target simulation system. It is therefore especially well-suited for all language-based simulation systems. The prerequisite for using the methodology is an appropriate representation of the system under investigation in the Core Manufacturing Simulation Data (CSMD) format. The applicability of our methodology is demonstrated for the simulation language SLX as well as for the visualization system Proof Animation.
http://dx.doi.org/10.1109/WSC.2012.6464981
Using protocol state machines to support simulation-based emulation projects. - In: Modelling and Simulation 2012, ISBN 978-90-77381-73-1, (2012), S. 234-238
Emulation is used to offer a simulated material flow system for the process of control software development and commissioning. The integration of Manufacturing Execution Systems (MES) with an emulation model is an error prone process and involves multiple stakeholders, including emulation engineers and control engineers. Typically, there is no complete formal description of the interface communication between the MES and the emulation model. This article suggests the use of protocol state machines to firstly formally describe the interface communication and secondly analyze emulation experiments based on the log files of the involved systems. The article further presents a case study and a prototype which have successfully applied the concept of protocol state machines.