Introducing Behavior in Function Blocks

Colloque sans acte à diffusion restreinte. nationale.National audienceFor developing an efficient and dependable control system, it is necessary to construct a model, which can fully describe its control structure, function and behaviour. To ensure interoperability between components, function blocks should be used. Nevertheless, the behaviour is not enough precise for validating temporal interoperability. We propose to add to function blocks a behaviour model. It provides a runtime machine allowing simulation

A symbolic cost model for asynchronous parallel programs with structured dependences

Rapport interne.We propose to associate a symbolic cost to a asynchronous parallel program. In contrast to classical approaches, we take into account all the dynamic asynchronism related to the different initial states that generate dynamic independences. We introduce an asynchronous intermediate model called SCP. It only imposes static independences allowing a sequential lecture of programs. To compute the symbolic cost, we condition the existence of a dependence by annotating it with a predicate on program variables. To evaluate the cost in the initial environment, predicates are transformed by a backward method based on the model Weakest Liberal Preconditions Calculus. The resulting symbolic cost is parameterized by the initial environment and integrates dynamic dependences

Component based deployment of industrial control systems: a hybrid scheduling approach

This paper deals with the IEC 61499 standard. A function block (FB) is an event triggered component and an application is a distributed FBs network on several devices. We consider these devices as multi-tasking PLCs. To validate the temporal behavior inside a device, we propose a hybrid scheduling approach combining off-line and on-line policies. This approach transforms application blocks into tasks thanks to the off-line policy. Then, it checks their required on-line feasibility. On the other hand, we propose also a temporal charcaterization of exchanged messages between devices to check also their online feasibility

A degraded scheduling generation of a component based application

This paper deals with control applications designed using the component-based standard IEC 61499. In this standard, a function block is an event triggered component and an application is a function blocks network. Supposing end to end delays on applications behavior, the hard temporal validation of FBs networks may be not feasible. We propose to weaken these delays by tolerance constraints deduced from specifications. Exploiting the (m, k) model to specify these constraints, we propose a schedulability analysis generating a degraded scheduling to use by a sequencer at run-time

A Distributed Algorithm for the Validation of Timed State Machines

Colloque avec actes et comité de lecture. internationale.International audienceIn this paper, we propose an a priori validation technique for time critical systems modelized thanks to timed automata. We validate the model of a given system using a hybrid method combining exhaustive exploration and simulation. For critical parts of the state machine, the exhaustive exploration produces a deterministic proof and a symbolic computation of the resulting clocks and constraints with regard to the initial ones. We can perform simulations of the complete state machine substituting these critical parts with the corresponding symbolic computation. In this paper, we propose an algorithm to automatically partition the automata into independent parts. Therefore, it is possible to parallelize the exhaustive analysis. || Dans ce papier, nous proposons une technique de validation a priori pour les systèmes temps critiques modélisés par des automates temporisés. Nous validons le modèle d'un système en utilisant une méthode hybride qui combine l'exploration exhaustive et l

A hybrid scheduling approach of centralized component based control applications

http://ieeexplore.ieee.org/This paper deals with the component based standard IEC 61499. A function block (FB) is an event triggered component and an application is a network of FBs. This network is centralized in a multi-tasking PLC. To validate the temporal behavior of the application blocks, we propose a hybrid scheduling approach combining off-line and on-line policies. The off-line policy allows to generate pre-schedulings for FBs. We associate one pre-scheduling to one task of the PLC. We apply then an existing schedulability condition to check the feasibility of these tasks

A static scheduling generator for the deployment of a component based application

This paper proposes a static scheduling of an application designed using the IEC 61499 standard. In this standard, a function block (FB) is an event triggered component and an application is a FBs network. According to specifications, we propose temporal constraints on the application behavior. To verify these constraints, we propose to transform the application blocks into a particular tasks system with precedence constraints. The purpose is to exploit previous works on scheduling. In addition, we propose a schedulability analysis generating an accessibility graph of the application. This graph allows the construction of a static scheduling to use by a sequencer at run-time

Proteus, des web services pour les systèmes de maintenance

Colloque avec actes et comité de lecture. nationale.National audienceLe projet PROTEUS a comme objectif de fournir une plate-forme et les concepts génériques pour construire des systèmes de e-maintenance industrielle incluant les systèmes existants d'acquisition de données, de contrôle - commande, de gestion de la maintenance, d'aide au diagnostic, de gestion de la documentation, etc. Le but de la plate-forme est non seulement d'intégrer des outils existants, mais aussi de prévoir l'évolution de celle-ci au travers de l'introduction de nouveaux services. Les concepts de Web services, d'ontologie et de services génériques associés à des modèles génériques des données sont au centre de la solution en cours de développement. En effet, ces techniques permettent de garantir l'interopérabilité de systèmes hétérogènes. Cet article décrit les principes de la solution en s'appuyant sur un exemple de processus et un scénario typique de maintenance corrective. De plus, il décrit les résultats préliminaires obtenus lors des premières expérimentations

PROTEUS – Creating Distributed Maintenance Systems through an Integration Platform

International audienceThis paper is based on the results from the project PROTEUS sponsored by the French Ministry of Economy, Finance and Industry and the Federal Ministry of Education and Research of Germany under the label of European Commission Initiative ITEA. It presents the architecture and the basic concepts of an integration platform, which constitutes the framework of systems implementing the tasks dedicated to remote maintenance, as well as other applications, for large and medium scale industrial installation. The approach illustrated here is useful for executing any maintenance strategy by implementing the relevant means for controlling workflow between several system components as well as the component's integration itself. The paper first points out the need for designing such a maintenance-oriented platform, continues with a requirements analysis to a global maintenance system followed by the description of the fundamentals of a maintenance application integration system. Finally a sample implementation of a maintenance scenario is given

Layout of a specification guide

Manuel technique.The goal of this presentation is to provide a guide to specify web services using UML diagrams