A Model-based transformation process to validate and implement high-integrity systems

Despite numerous advances, building High-Integrity Embedded systems remains a complex task. They come with strong requirements to ensure safety, schedulability or security properties; one needs to combine multiple analysis to validate each of them. Model-Based Engineering is an accepted solution to address such complexity: analytical models are derived from an abstraction of the system to be built. Yet, ensuring that all abstractions are semantically consistent, remains an issue, e.g. when performing model checking for assessing safety, and then for schedulability using timed automata, and then when generating code. Complexity stems from the high-level view of the model compared to the low-level mechanisms used. In this paper, we present our approach based on AADL and its behavioral annex to refine iteratively an architecture description. Both application and runtime components are transformed into basic AADL constructs which have a strict counterpart in classical programming languages or patterns for verification. We detail the benefits of this process to enhance analysis and code generation. This work has been integrated to the AADL-tool support OSATE2

An implementation of the behavior annex in the AADL-toolset Osate2

AADL is a modeling language to design and analyze High-Integrity Distributed and Real-time systems. Embedded sub-languages published as AADL annexes extend an AADL model to enhance analysis. The behavior annex specifies the behavior of an AADL application model. An implantation of this annex allows to perform behavior analysis. In addition, as there are several AADL annexes, the implementation of generic mechanisms to support each one of them is challenging. The behavior annex is a valid candidate to illustrate these challenges by combining several sub-languages. In this paper we expose our experiment to support the behavior annex in the reference AADL toolset OSATE2. This one, supports the AADL version 2 by providing a front-end and a set of analysis plug-ins to analyze an AADL model

Distributed Simulation of Heterogeneous and Real-time Systems

This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-defined manner. This work leverages existing frameworks to facilitate the integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation

Une approche intégrée pour la validation et la génération de systèmes critiques par raffinement incrémental de modèles architecturaux

The increasing complexity of distributed realtime and embedded (DRE) systems and their implication in various domains imply new design and development methods. In safety- criticial domains such as space, aeronautical, transport or medicine, their failure could result in the failure of the mission, or in dramatic damages such as human losses. This particular class of systems comes with strong requirements to satisfy safety, reliability and security properties. The Model-driven Engineering (MDE) introduces the concept of «model» - an abstract description of the system and a set of tools (editor, transformation engine, code generator) to simplify and automatize the design, the validation and the implementation of the system. Thus, various abstractions are realized using different domain-specific modeling languages in order to assess one particular aspect of the system and to re-use model-based analysis tools and generative technologies. These various representations may share some commonalities but the consistency between them is hard to validate (for example : Is the analyzed system the same as the generated one ?).This PhD thesis leverages MDE concepts and mechanisms, to enhance the reliability of the model-based development process of DRE systems. Our approach is based on the definition of the architectural and behavioral modeling language AADLHI Ravenscar, a restriction of AADL (Architecture Analysis & Design Language) and its behavioral annex. This subset of AADL constructs, comes up with a semantic close to the one of an imperative programming language, to drive both the analysis and the code generation of the application components and its relying execution platform (middleware) components...L’augmentation de la complexité des systèmes temps-réel répartis embarqués (TR2E) et leur implication dans de nombreux domaines de notre quotidien imposent de nouvelles mé thodes de réalisation. Dans les domaines dits critiques (transport, médecine...) ces systèmes doivent satisfaire des contraintes dures pour garantir leur bon fonctionnement et éviter toutes défaillances qui engendreraient des conséquences financières ou humaines dramatiques. L’Ingénierie Dirigée par les Modèles (IDM) introduit le “modèle” - i.e. une description abstraite du système - et un ensemble d’outils (édition, transformation...) permettant la simplification et l’automatisation des étapes de conception, de validation et de génération du système. Ainsi, différentes abstractions du système sont élaborées dans des formalismes spécifiques de manière à couvrir un aspect du système et à permettre la réutilisation des outils d’analyse et de génération existants. Cependant, ces multiples représentations évoluent à des niveaux d’abstractions différents et il n’est pas toujours évident de mettre en corrélation système analysé et système généré. Ce travail de thèse exploite les concepts et les mécanismes offerts par l’IDM pour améliorer la fiabilité du processus de réalisation des systèmes critiques basé sur les modèles. L’approche que nous avons définie repose sur la définition du langage de modélisation architecturale et comportementale AADL-HI Ravenscar - un sous-ensemble du langage AADL (Architecture Analysis & Design Language) et de son annexe comportementale - contraint pour permettre conjointement l’analyse et la génération de l’ensemble des composants de l’application y compris de son exécutif, avec une sémantique proche d’un langage de programmation impératif..

Environnement de coopération de simulation pour la conception de systèmes cyber-physiques

La conception de systèmes cyber-physiques (CPS) est une activité complexe qui requiert l’utilisation de plusieurs méthodes et outils pendant le processus de développement. L’objectif du travail présenté est de fournir un moyen de simuler plusieurs types de modèles réalisés à plusieurs niveaux dans la phase de conception. Nous avons développé un environnement de co-simulation permettant la coopération de deux outils de simulation open source : Ptolemy II et HLA/CERTI. Ptolemy II permet la modélisation hiérarchique de systèmes hétérogènes tandis qu’HLA/CERTI permet des simulations distribuées interopérables (parfois en intégrant des éléments matériels). Dans le papier, nous détaillons les points communs et différences sémantiques de la gestion du temps. Trois nouveaux objets Ptolemy : un attribut HlaManager ainsi que deux acteurs, HlaPublisher et HlaSubscriber, ont été développés afin de réaliser l’interface entre les deux outils de simulation. Une étude de cas est détaillée à la fin du papier

Distributed Simulation of Heterogeneous and Real-time Systems

This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-definedmanner. This work leverages existing frameworks to facilitatethe integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation

Les pratiques évaluatives en éducation physique à l'ordre d'enseignement collégial Rapport d'analyse du sondage /

Titre de l'écran-titre (visionné le 8 avril. 2013

An integrated approach to validate and generate high-integrity systems by incremental refinement of architectural models

L’augmentation de la complexité des systèmes temps-réel répartis embarqués (TR2E) et leur implication dans de nombreux domaines de notre quotidien imposent de nouvelles mé thodes de réalisation. Dans les domaines dits critiques (transport, médecine...) ces systèmes doivent satisfaire des contraintes dures pour garantir leur bon fonctionnement et éviter toutes défaillances qui engendreraient des conséquences financières ou humaines dramatiques. L’Ingénierie Dirigée par les Modèles (IDM) introduit le “modèle” - i.e. une description abstraite du système - et un ensemble d’outils (édition, transformation...) permettant la simplification et l’automatisation des étapes de conception, de validation et de génération du système. Ainsi, différentes abstractions du système sont élaborées dans des formalismes spécifiques de manière à couvrir un aspect du système et à permettre la réutilisation des outils d’analyse et de génération existants. Cependant, ces multiples représentations évoluent à des niveaux d’abstractions différents et il n’est pas toujours évident de mettre en corrélation système analysé et système généré. Ce travail de thèse exploite les concepts et les mécanismes offerts par l’IDM pour améliorer la fiabilité du processus de réalisation des systèmes critiques basé sur les modèles. L’approche que nous avons définie repose sur la définition du langage de modélisation architecturale et comportementale AADL-HI Ravenscar - un sous-ensemble du langage AADL (Architecture Analysis & Design Language) et de son annexe comportementale - contraint pour permettre conjointement l’analyse et la génération de l’ensemble des composants de l’application y compris de son exécutif, avec une sémantique proche d’un langage de programmation impératif...The increasing complexity of distributed realtime and embedded (DRE) systems and their implication in various domains imply new design and development methods. In safety- criticial domains such as space, aeronautical, transport or medicine, their failure could result in the failure of the mission, or in dramatic damages such as human losses. This particular class of systems comes with strong requirements to satisfy safety, reliability and security properties. The Model-driven Engineering (MDE) introduces the concept of «model» - an abstract description of the system and a set of tools (editor, transformation engine, code generator) to simplify and automatize the design, the validation and the implementation of the system. Thus, various abstractions are realized using different domain-specific modeling languages in order to assess one particular aspect of the system and to re-use model-based analysis tools and generative technologies. These various representations may share some commonalities but the consistency between them is hard to validate (for example : Is the analyzed system the same as the generated one ?).This PhD thesis leverages MDE concepts and mechanisms, to enhance the reliability of the model-based development process of DRE systems. Our approach is based on the definition of the architectural and behavioral modeling language AADLHI Ravenscar, a restriction of AADL (Architecture Analysis & Design Language) and its behavioral annex. This subset of AADL constructs, comes up with a semantic close to the one of an imperative programming language, to drive both the analysis and the code generation of the application components and its relying execution platform (middleware) components..

Behavioral Modular Description of Fault Tolerant Distributed Systems with AADL Behavioral Annex

International audienceAADL is an architecture description language intended for model-based engineering of high-integrity distributed systems. The AADL Behavior Annex (AADL-BA) is an extension allowing the refinement of behavioral aspects described through an AADL architectural description. When implementing Distributed Real-time Embedded system (DRE), fault tolerance concerns are integrated by applying replication patterns. We considered a simplified design of the primary backup replication pattern as a running example to analyze the modeling capabilities of AADL and its annex. Our contribution lies in the identification of the drawbacks and benefits of this modeling language for accurate description of the synchronization mechanisms integrated in this example

Architectural and Behavioral Modeling with AADL for Fault Tolerant Embedded Systems

International audienceAADL is an architecture description language intended for model-based engineering of high-integrity systems. The AADL Behavior Annex is an extension allowing the refinement of behavioral aspects described through AADL. When implementing Distributed Real-time Embedded system, fault tolerance concerns are integrated by applying replication patterns. We considered a simplified design of the primary backup replication pattern to express the modeling capabilities of AADL and its annex. Our contribution intends to give accurate description of the synchronization mechanisms integrated in this example