Ingénierie systèmes basée sur les modèles appliquée à la gestion et l'intégration des données de conception et de simulation : application aux métiers d'intégration et de simulation de systèmes aéronautiques complexes

The aim of this doctoral thesis is to contribute to the facilitation of design, integration and simulation activities in the aeronautics industry, but more generally in the context of collaborative complex product development. This objective is expected to be achieved through the use and improvement of digital engineering capabilities. During the last decade, the Digital Mock-Up (DMU) – supported by Product Data Management (PDM) systems – became a key federating environment to exchange/share a common 3D CAD model-based product definition between co-designers. It enables designers and downstream users(analysts) to access the geometry of the product assembly. While enhancing 3D and 2D simulations in a collaborative and distributed design process, the DMU offers new perspectives for analysts to retrieve the appropriate CAD data inputs used for Finite Element Analysis (FEA), permitting hence to speed-up the simulation preparation process. However, current industrial DMUs suffer from several limitations, such as the lack of flexibility in terms of content and structure, the lack of digital interface objects describing the relationships between its components and a lack of integration with simulation activities and data.This PhD underlines the DMU transformations required to provide adapted DMUs that can be used as direct input for large assembly FEA. These transformations must be consistent with the simulation context and objectives and lead to the concept of “Product View” applied to DMUs andto the concept of “Behavioural Mock-Up” (BMU). A product view defines the link between a product representation and the activity or process (performed by at least one stakeholder) that use or generate this representation as input or output respectively. The BMU is the equivalent of the DMU for simulation data and processes. Beyond the geometry, which is represented in the DMU,the so-called BMU should logically link all data and models that are required to simulate the physical behaviour and properties of a single component or an assembly of components. The key enabler for achieving the target of extending the concept of the established CAD-based DMU to the behavioural CAE-based BMU is to find a bi-directional interfacing concept between the BMU and its associated DMU. This the aim of the Design-Analysis System Integration Framework (DASIF) proposed in this PhD. This framework might be implemented within PLM/SLM environments and interoperate with both CAD-DMU and CAE-BMU environments. DASIF combines configuration data management capabilities of PDM systems with MBSE system modelling concepts and Simulation Data Management capabilities.This PhD has been carried out within a European research project: the CRESCENDO project, which aims at delivering the Behavioural Digital Aircraft (BDA). The BDA concept might consist in a collaborative data exchange/sharing platform for design-simulation processes and models throughout the development life cycle of aeronautics products. Within this project, the Product Integration Scenario and related methodology have been defined to handle digital integration chains and to provide a test case scenario for testing DASIF concepts. These latter have been used to specify and develop a prototype of an “Integrator Dedicated Environment” implemented in commercial PLM/SLM applications. Finally the DASIF conceptual data model has also served as input for contributing to the definition of the Behavioural Digital Aircraft Business Object Model: the standardized data model of the BDA platform enabling interoperability between heterogeneous PLM/SLM applications and to which existing local design environments and new services to be developed could plug.L’objectif de cette thèse est de contribuer au développement d’approches méthodologiques et d’outils informatiques pour développer les chaînes d’intégration numériques en entreprise étendue. Il s’agit notamment de mieux intégrer et d’optimiser les activités de conception, d’intégration et de simulation dans le contexte du développement collaboratif des produits/systèmes complexes.La maquette numérique (DMU) – supportée par un système de gestion de données techniques (SGDT ou PDM) – est devenue ces dernières années un environnement fédérateur clé pour échanger et partager une définition technique et une représentation 3D commune du produit entre concepteurs et partenaires. Cela permet aux concepteurs ainsi qu’aux utilisateurs en aval (ceux qui sont en charge des simulations numériques notamment) d’avoir un accès à la géométrie du produit virtuel assemblé. Alors que les simulations numériques 3D et 2D prennent une place de plus en plus importante dans le cycle de développement du produit, la DMU offre de nouvelles perspectives à ces utilisateurs pour récupérer et exploiter les données CAO appropriées et adaptées pour les analyses par éléments finis. Cela peut ainsi permettre d’accélérer le processus de préparation du modèle de simulation. Cependant, les environnements industriels de maquettes numériques sont actuellement limités dans leur exploitation par : - un manque de flexibilité en termes de contenu et de structure, - l’absence d’artefact numérique 3D permettant de décrire les interfaces des composants de l’assemblage, - un manque d’intégration avec les données et activités de simulation.Cette thèse met notamment l’accent sur les transformations à apporter aux DMU afin qu’elles puissent être utilisées comme données d’entrée directes pour les analyses par éléments finis d’assemblages volumineux (plusieurs milliers de pièces). Ces transformations doivent être en cohérence avec le contexte et les objectifs de simulation et cela nous a amené au concept de « vue produit » appliquée aux DMUs, ainsi qu’au concept de « maquette comportementale » (BMU). Une « vue produit » définit le lien entre une représentation du produit et l’activité ou le processus utilisant ou générant cette représentation. La BMU est l’équivalent de la DMU pour les données et les processus de simulation. Au delà des géométries discrétisées, la dénommée BMU devrait, en principe, lier toutes les données et les modèles qui seront nécessaires pour simuler le comportement d’un ou plusieurs composants. L’élément clé pour atteindre l’objectif d’élargir le concept établi de la DMU (basée sur des modèles CAO) à celui de la BMU (basée sur des modèles CAE), est de trouver un concept d’interface bidirectionnel entre la BMU et sa DMU associée. C’est l’objectif du « Design-Analysis System Integration Framework » (DASIF) proposé dans cette thèse de doctorat. Ce cadre a vise à être implémenté au sein d’environnements PLM/SLM et doit pouvoir inter-opérer à la fois avec les environnements CAD-DMU et CAE-BMU. DASIF allie les fonctionnalités de gestion de données et de configuration des systèmes PDM avec les concepts et formalismes d’ingénierie système basée sur les modèles (MBSE) et des fonctionnalités de gestion des données de simulation (SDM). Cette thèse a été menée dans le cadre d’un projet de recherche européen : le projet CRESCENDO qui vise à développer le « Behavioural Digital Aircraft » (BDA) qui a pour vocation d’être la« colonne vertébrale » des activités de conception et simulation avancées en entreprise étendue. Le concept du BDA doit s’articuler autour d’une plateforme collaborative d’échange et de partage des données de conception et de simulation tout au long du cycle de développement et de vie des produits aéronautiques. [...

Autotuning the Intel HLS Compiler using the Opentuner Framework

High level synthesis (HLS) tools can be used to improve design flow and decrease verification times for field programmable gate array (FPGA) and application specific integrated circuit (ASIC) design. The Intel HLS Compiler is a high level synthesis tool that takes in untimed C/C++ as input and generates production-quality register transfer level (RTL) code that is optimized for Intel FPGAs. The translation does, however, require multiple iterations and manual optimizations to get comparable synthesized results to that of a solution written in a hardware descriptive language. The synthesis results can vary greatly based upon coding style and optimization techniques, and typically require an in-depth knowledge of FPGAs to fully optimize the translation which limits the audience of the tool. The extra abstraction that the C/C++ source code presents can also make it difficult to meet more specific design requirements; this includes designs to meet specific resource usage or performance based metrics. To improve the quality of results generated by the Intel HLS Compiler without a manual iterative process that requires an in-depth knowledge of FPGAs, this research proposes a method of automating some of the optimization techniques that improve the synthesized design through an autotuning process. The proposed approach utilizes the PyCParser library to parse C source files and the OpenTuner Framework to autotune the synthesis to provide a method that generates results that better meet the needs of the designer's requirements through lower FPGA resource usage or increased design performance. Such functionality is not currently available in Intel's commercial tools. The proposed approach was tested with the CHStone Benchmarking Suite of C programs as well as a standard digital signal processing finite impulse response filter. The results show that the commercial HLS tool can be automatically autotuned through placeholder injection using a source parsing tool for C code and using the OpenTuner Framework to autotune the results. For designs that are small in nature and include conducive structures to be autotuned, the results indicate resource usage reductions and/or performance increases of up to 40% as compared to the default Intel HLS Compiler results. The method developed in this research also allows additional design targets to be specified through the autotuner for consideration in the synthesized design which can yield results that are better matched to a design's requirements

Compliance flow: an intelligent workflow management system to support engineering processes

This work is about extending the scope of current workflow management systems to support engineering processes. On the one hand engineering processes are relatively dynamic, and on the other their specification and performance are constrained by industry standards and guidelines for the sake of product acceptability, such as IEC 61508 for safety and ISO 9001 for quality. A number of technologies have been proposed to increase the adaptability of current workflow systems to deal with dynamic situations. A primary concern is how to support open-ended processes that cannot be completely specified in detail prior to their execution. A survey of adaptive workflow systems is given and the enabling technologies are discussed. Engineering processes are studied and their characteristics are identified and discussed. Current workflow systems have been successfully used in managing "administrative" processes for some time, but they lack the flexibility to support dynamic, unpredictable, collaborative, and highly interdependent engineering processes. [Continues.

Visualising and scaling information in a flight operations schedule

Flygprestanda AB supplies IT services for airline operations, management and control. The system delivered to facilitate this is the Flight Operation Control System or FOCS. This thesis addresses the Schedule View service included in the FOCS system. The Schedule View is a tool where the user gets an overview of aircrafts and planned flights. In addition aircrafts and flights can be added and modified. It is crucial that the usability is not hampered by the number of aircrafts and their respective flights. Since Flygprestanda's customers vary in size, from large airlines to single aircraft customers (business jet), the Schedule View should be able to fulfil all needs. With an iterative work process we will locate flaws in the user interface, and design and implement improvements. To ensure quality of our implemented solutions an evaluation phase will be included in the iterative work process. The results of our evaluation activities will be presented as a framework for service implementation in this domain

Development of a standard framework for manufacturing simulators

Discrete event simulation is now a well established modelling and experimental technique for the analysis of manufacturing systems. Since it was first employed as a technique, much of the research and commercial developments in the field have been concerned with improving the considerable task of model specification in order to improve productivity and reduce the level of modelling and programming expertise required. The main areas of research have been the development of modelling structures to bring modularity in program development, incorporating such structures in simulation software systems which would alleviate some of the programming burden, and the use of automatic programming systems to develop interfaces that would raise the model specification to a higher level of abstraction. A more recent development in the field has been the advent of a new generation of software, often referred to as manufacturing simulators, which have incorporated extensive manufacturing system domain knowledge in the model specification interface. Many manufacturing simulators are now commercially available, but their development has not been based on any common standard. This is evident in the differences that exist between their interfaces, internal data representation methods and modelling capabilities. The lack of a standard makes it impossible to reuse any part of a model when a user finds it necessary to move from one simulator to another. In such cases, not only a new modelling language has to be learnt but also the complete model has to be developed again requiring considerable time and effort. The motivation for the research was the need for the development of a standard that is necessary to improve reusability of models and is the first step towards interchangability of such models. A standard framework for manufacturing simulators has been developed. It consists of a data model that is independent of any simulator, and a translation module for converting model specification data into the internal data representation of manufacturing simulators; the translators are application specific, but the methodology is common and illustrated for three popular simulators. The data model provides for a minimum common model data specification which is based on an extensive analysis of existing simulators. It uses dialogues for interface and the frame knowledge representation method for modular storage of data. The translation methodology uses production rules for data mapping

Implications and Limitations of Securing an InfiniBand Network

The InfiniBand Architecture is one of the leading network interconnects used in high performance computing, delivering very high bandwidth and low latency. As the popularity of InfiniBand increases, the possibility for new InfiniBand applications arise outside the domain of high performance computing, thereby creating the opportunity for new security risks. In this work, new security questions are considered and addressed. The study demonstrates that many common traffic analyzing tools cannot monitor or capture InfiniBand traffic transmitted between two hosts. Due to the kernel bypass nature of InfiniBand, many host-based network security systems cannot be executed on InfiniBand applications. Those that can impose a significant performance loss for the network. The research concludes that not all network security practices used for Ethernet translate to InfiniBand as previously suggested and that an answer to meeting specific security requirements for an InfiniBand network might reside in hardware offload