10,636 research outputs found

    Applications integration for manufacturing control systems with particular reference to software interoperability issues

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    The introduction and adoption of contemporary computer aided manufacturing control systems (MCS) can help rationalise and improve the productivity of manufacturing related activities. Such activities include product design, process planning and production management with CAD, CAPP and CAPM. However, they tend to be domain specific and would generally have been designed as stand-alone systems where there is a serious lack of consideration for integration requirements with other manufacturing activities outside the area of immediate concern. As a result, "islands of computerisation" exist which exhibit deficiencies and constraints that inhibit or complicate subsequent interoperation among typical MCS components. As a result of these interoperability constraints, contemporary forms of MCS typically yield sub-optimal benefits and do not promote synergy on an enterprise-wide basis. The move towards more integrated manufacturing systems, which requires advances in software interoperability, is becoming a strategic issue. Here the primary aim is to realise greater functional synergy between software components which span engineering, production and management activities and systems. Hence information of global interest needs to be shared across conventional functional boundaries between enterprise functions. The main thrust of this research study is to derive a new generation of MCS in which software components can "functionally interact" and share common information through accessing distributed data repositories in an efficient, highly flexible and standardised manner. It addresses problems of information fragmentation and the lack of formalism, as well as issues relating to flexibly structuring interactions between threads of functionality embedded within the various components. The emphasis is on the: • definition of generic information models which underpin the sharing of common data among production planning, product design, finite capacity scheduling and cell control systems. • development of an effective framework to manage functional interaction between MCS components, thereby coordinating their combined activities. • "soft" or flexible integration of the MCS activities over an integrating infrastructure in order to (i) help simplify typical integration problems found when using contemporary interconnection methods for applications integration; and (ii) enable their reconfiguration and incremental development. In order to facilitate adaptability in response to changing needs, these systems must also be engineered to enable reconfigurability over their life cycle. Thus within the scope of this research study a new methodology and software toolset have been developed to formally structure and support implementation, run-time and change processes. The tool set combines the use of IDEFO (for activity based or functional modelling), IDEFIX (for entity-attribute relationship modelling), and EXPRESS (for information modelling). This research includes a pragmatic but effective means of dealing with legacyl software, which often may be a vital source of readily available information which supports the operation of the manufacturing enterprise. The pragmatism and medium term relevance of the research study has promoted particular interest and collaboration from software manufacturers and industrial practitioners. Proof of concept studies have been carried out to implement and evaluate the developed mechanisms and software toolset

    An overview of decision table literature 1982-1995.

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    This report gives an overview of the literature on decision tables over the past 15 years. As much as possible, for each reference, an author supplied abstract, a number of keywords and a classification are provided. In some cases own comments are added. The purpose of these comments is to show where, how and why decision tables are used. The literature is classified according to application area, theoretical versus practical character, year of publication, country or origin (not necessarily country of publication) and the language of the document. After a description of the scope of the interview, classification results and the classification by topic are presented. The main body of the paper is the ordered list of publications with abstract, classification and comments.

    Ship product modelling

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    This paper is a fundamental review of ship product modeling techniques with a focus on determining the state of the art, to identify any shortcomings and propose future directions. The review addresses ship product data representations, product modeling techniques and integration issues, and life phase issues. The most significant development has been the construction of the ship Standard for the Exchange of Product Data (STEP) application protocols. However, difficulty has been observed with respect to the general uptake of the standards, in particular with the application to legacy systems, often resulting in embellishments to the standards and limiting the ability to further exchange the product data. The EXPRESS modeling language is increasingly being superseded by the extensible mark-up language (XML) as a method to map the STEP data, due to its wider support throughout the information technology industry and its more obvious structure and hierarchy. The associated XML files are, however, larger than those produced using the EXPRESS language and make further demands on the already considerable storage required for the ship product model. Seamless integration between legacy applications appears to be difficult to achieve using the current technologies, which often rely on manual interaction for the translation of files. The paper concludes with a discussion of future directions that aim to either solve or alleviate these issues

    Graduate Catalog Center for Computer and Information Sciences

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    Digital Twins of production systems - Automated validation and update of material flow simulation models with real data

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    Um eine gute Wirtschaftlichkeit und Nachhaltigkeit zu erzielen, müssen Produktionssysteme über lange Zeiträume mit einer hohen Produktivität betrieben werden. Dies stellt produzierende Unternehmen insbesondere in Zeiten gesteigerter Volatilität, die z.B. durch technologische Umbrüche in der Mobilität, sowie politischen und gesellschaftlichen Wandel ausgelöst wird, vor große Herausforderungen, da sich die Anforderungen an das Produktionssystem ständig verändern. Die Frequenz von notwendigen Anpassungsentscheidungen und folgenden Optimierungsmaßnahmen steigt, sodass der Bedarf nach Bewertungsmöglichkeiten von Szenarien und möglichen Systemkonfigurationen zunimmt. Ein mächtiges Werkzeug hierzu ist die Materialflusssimulation, deren Einsatz aktuell jedoch durch ihre aufwändige manuelle Erstellung und ihre zeitlich begrenzte, projektbasierte Nutzung eingeschränkt wird. Einer längerfristigen, lebenszyklusbegleitenden Nutzung steht momentan die arbeitsintensive Pflege des Simulationsmodells, d.h. die manuelle Anpassung des Modells bei Veränderungen am Realsystem, im Wege. Das Ziel der vorliegenden Arbeit ist die Entwicklung und Umsetzung eines Konzeptes inkl. der benötigten Methoden, die Pflege und Anpassung des Simulationsmodells an die Realität zu automatisieren. Hierzu werden die zur Verfügung stehenden Realdaten genutzt, die aufgrund von Trends wie Industrie 4.0 und allgemeiner Digitalisierung verstärkt vorliegen. Die verfolgte Vision der Arbeit ist ein Digitaler Zwilling des Produktionssystems, der durch den Dateninput zu jedem Zeitpunkt ein realitätsnahes Abbild des Systems darstellt und zur realistischen Bewertung von Szenarien verwendet werden kann. Hierfür wurde das benötigte Gesamtkonzept entworfen und die Mechanismen zur automatischen Validierung und Aktualisierung des Modells entwickelt. Im Fokus standen dabei unter anderem die Entwicklung von Algorithmen zur Erkennung von Veränderungen in der Struktur und den Abläufen im Produktionssystem, sowie die Untersuchung des Einflusses der zur Verfügung stehenden Daten. Die entwickelten Komponenten konnten an einem realen Anwendungsfall der Robert Bosch GmbH erfolgreich eingesetzt werden und führten zu einer Steigerung der Realitätsnähe des Digitalen Zwillings, der erfolgreich zur Produktionsplanung und -optimierung eingesetzt werden konnte. Das Potential von Lokalisierungsdaten für die Erstellung von Digitalen Zwillingen von Produktionssystem konnte anhand der Versuchsumgebung der Lernfabrik des wbk Instituts für Produktionstechnik demonstriert werden

    Synergy of the Developed 6D BIM Framework and Conception of the nD BIM Framework and nD BIM Process Ontology

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    The author developed a unified nD framework and process ontology for Building Information Modeling (BIM). The research includes a framework developed for 6D BIM, nD BIM, and nD ontology that defines the domain and sub-domain constructs for future nD BIM dimensions. The nD ontology defines the relationships of kinds within any new proposed dimensional domain for BIM. The developed nD BIM framework and ontology takes into account the current 2D-5D BIM dimensions. There is a synergy between the 6D and nD framework that allows the nD framework and ontology to be utilized as a unified template for future dimensional development. Future dimensions for BIM are referred as nD dimensions. The Architecture, Engineering, Construction, and Facility Management (AEC/FM) industries are suffering from many problems in the area of interoperability among BIM dimensions. All nD dimensions must be interoperable. The congestion between interoperable dimensions and communication among AEC/FM stakeholders are the main problems to be resolved. The objective of the research is to solve these problems by utilizing one single nD framework and ontology for nD BIMs. The AEC/FM industries can benefit from the developed 6D framework, nD framework and nD process ontology. nD dimensions must have ontological rules that clearly define the new dimension. The AEC/FM needs non-abstract dimensions to succeed in the areas of seamless dimensional integration, interoperability, round tripping of dimensional data, and precise collaboration among stakeholders. Defined dimensions allow future dimensions to be implemented in an integrated workflow. nD ontology demonstrates new dimensional domain K\u27 shall be defined while also explicitly defining its subset-domains {K1, K2…Kn}, and subset domains K shall contain some x information for interoperability among dimensions that are within K\u27. The research contributions are the framework and ontology for nD BIM. The author conducted case studies that validate the nD methodology. The case studies show that the methodology of the input, output, control and mechanism are correct and the theory can be utilized in application for the AEC/FM and is applicable for other industries. Other contributions include the custom web-based BimServer that serves as the central repository for harvesting all control data within nD BIMs and allows all stakeholders to participate on projects in real-time via an embedded virtual environment in the BimServer. The nD BIM methodology consists of one object-oriented parametric product data model as the input and the output. A relational database is the mechanism for the nD BIM process that distributes the dimensional data. The database is the crux of the nD BIM and it allows the interoperability between the nD dimensions and querying of the nD parametric product data

    An approach to resource modelling in support of the life cycle engineering of enterprise systems

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    Enterprise modelling can facilitate the design, analysis, control and construction of contemporary enterprises which can compete in world-wide Product markets. This research involves a systematic study of enterprise modelling with a particular focus on resource modelling in support of the life cycle engineering of enterprise systems. This led to the specification and design of a framework for resource modelling. This framework was conceived to: classify resource types; identify the different functions that resource modelling can support, with respect to different life phases of enterprise systems; clarify the relationship between resource models and other modelling perspectives provide mechanisms which link resource models and other types of models; identify guidelines for the capture of information - on resources, leading to the establishment of a set of resource reference models. The author also designed and implemented a resource modelling tool which conforms to the principles laid down by the framework. This tool realises important aspects of the resource modeffing concepts so defined. Furthermore, two case studies have been carried out. One models a metal cutting environment, and the other is based on an electronics industry problem area. In this way, the feasibility of concepts embodied in the framework and the design of the resource modelling tool has been tested and evaluated. Following a literature survey and preliminary investigation, the CIMOSA enterprise modelling and integration methodology was adopted and extended within this research. Here the resource modelling tool was built by extending SEWOSA (System Engineering Workbench for Open System Architecture) and utilising the CIMBIOSYS (CINI-Building Integrated Open SYStems) integrating infrastructure. The main contributions of the research are that: a framework for resource modelling has been established; means and mechanisms have been proposed, implemented and tested which link and coordinate different modelling perspectives into an unified enterprise model; the mechanisms and resource models generated by this research support each Pfe phase of systems engineering projects and demonstrate benefits by increasing the degree to which the derivation process among models is automated
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