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Abstract

The civil aircraft's electrical flight control system has been changed to take benefit of technical improvements. New technologies, when mature, can be incorporated in aircrafts. Evolutions are considered towards a digital network between computers and actuators/sensors, and more distributed processing for actuators and sensors. Thus, new architectures are possible for future aircraft systems. The difficulty is to achieve the same safety and availability requirements with additional operational reliability (required by airlines). The challenge that faces the engineers is to design mass-produced fault-tolerant systems with reasonable cost. Analysis of existing electrical flight control system architectures of the Airbus and Boeing airplanes as well as future requirements drive us to introduce a brief overview for an incremental methodology of architectural design process based on progressive requirements injection.

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Abstract

The civil aircraft's electrical flight control system has been changed to take benefit of technical improvements. New technologies, when mature, can be incorporated in aircrafts. Evolutions are considered towards a digital network between computers and actuators/sensors, and more distributed processing for actuators and sensors. Thus, new architectures are possible for future aircraft systems. The difficulty is to achieve the same safety and availability requirements with additional operational reliability (required by airlines). The challenge that faces the engineers is to design mass-produced fault-tolerant systems with reasonable cost. Analysis of existing electrical flight control system architectures of the Airbus and Boeing airplanes as well as future requirements drive us to introduce a brief overview for an incremental methodology of architectural design process based on progressive requirements injection.

Mots-Clés / Keywords

Résumé

L'aboutissement aux Commandes de Vol Électriques (CDVE) des avions civils actuels s'est fait par étapes, après une longue maturation des différentes technologies mises en place. La prochaine étape est l'emploi de réseaux numériques (à la place des liaisons analogiques) entre les calculateurs et les capteurs/actionneurs, et une distribution de l'intelligence vers ces derniers. De nouvelles architectures de systèmes de CDVE sont donc envisageables. La problématique visée dans cet article est de répondre aux mêmes exigences de sécurité et de disponibilité qu'avant, ainsi qu'aux exigences croissantes (des compagnies aériennes) de fiabilité opérationnelle. L'étude des pratiques actuelles chez Airbus et Boeing, puis des exigences pour les avions de future génération, conduit à introduire les grandes lignes de notre proposition de démarche de conception incrémentale d'architectures répondant aux exigences considérées.

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Abstract

This chapter presents the specification of dependability benchmarks for general-purpose operating systems with respect to application erroneous behavior, and shows examples of benchmark results obtained for various versions of Windows and Linux operating systems. The benchmark measures are: operating system robustness (as regards possible erroneous inputs provided by the application software to the operating system (OS) via the application programming interface), the OS reaction, and restart times in the presence of faults. Two workloads are used for implementing the benchmark: PostMark, a file system performance benchmark for operating systems, and the Java Virtual Machine (JVM) middleware, a software layer on top of the OS allowing applications in Java language to be platform independent.

Abstract

This paper addresses the fault tolerance issues concerning the input-output ports (IOPs) of future multicore chips built up using massively defective nanotechnologies. Recall that the IOPs are critical to system dependability as they constitute bottlenecks for all communications between the chip and external resources. Various levels of modular redundancy in the IOPs are being considered for which we calculate the probability to maintain correct operation. We also calculate the cost attached to the proposed protective designs for the IOP, in terms of circuitry overhead.

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Abstract

SESAME (Software Environment for Software Analysis by Mutation Effects) is a fault injection tool using mutation as the target fault model. It has been used for 15 years to support dependability research at LAAS-CNRS. A salient feature of SESAME is that it is multi-language. This made it possible to inject faults into software written in assembly languages, procedural languages (Pascal, C), a data-flow language (LUSTRE), as well as in a declarative language for temporal planning in robotics. This paper provides an overview of the tool, and reports on its use in experimental research addressing either fault removal or fault tolerance topics.