Vers le diagnostic embarqué de défaillances dans les systèmes à événements discrets : application au domaine automobile

Cette thèse, réalisée dans le cadre d'une convention CIFRE entre ACTIA et le LAAS/CNRS, porte sur la détection et le diagnostic de défaillances fugitives dans les systèmes embarqués, avec une application dans le domaine automobile. Les méthodes proposées sont basées sur un modèle à événements discrets représentant le comportement observable du système surveillé en fonctionnement normal. L'étape de détection consiste à comparer la séquence d'événements observables émis par le système surveillé et la séquence d'événements attendus par le modèle. L'étape de localisation donne l'ensemble des événements potentiellement responsables des défauts observés. Cette étape se base sur l'approche "diagnostiqueur" développée par (Sampath et al., 1998), dont le principe repose sur la compilation hors-ligne de l'information de diagnostic dans une structure de données (appelé diagnostiqueur) qui relie efficacement les observations aux fautes lors du diagnostic en ligne. Cette thèse a abouti au développement de plusieurs applications permettant le diagnostic de défauts fugitifs et intermittents. Les travaux ont été validés sur un banc de test représentant une architecture réseau utilisée dans les véhicules de transports urbains (bus, métro...).This thesis deals with the diagnosis of behavior functions in the embedded network systems and especially in the automotive systems. It is focused on the localization of intermittent faults in discrete events systems. The proposed methods are based on a discrete events model representing the normal functioning of the observable behavior of the monitored system. The detection step consists of a comparison between the flow of observable events emitted by the monitored system and the flow foreseen by the model. A localization mechanism, based on the diagnoser approach (Sampath et al., 1998), points out the set of events potentially responsible for the faults. The aim of this approach is to get the diagnosis information into a data structure (off-line) which efficiently joins the observations with the faults during the on-line diagnosis. This thesis have lead to the building of many applications for the intermittent fault diagnosis. This works have been validated on a test bench representing the network used in the city transports (bus, subways...)

Usinage à Grande Vitesse - Modélisation analytique de la coupe orthogonale et validation expérimentale

Nous présentons dans cette étude le modèle analytique de la coupe orthogonale développé au LPMM. La modélisation de la bande primaire de cisaillement est couplée à une analyse thermique à l'interface outil-copeau. Une loi de frottement dépendante de la température moyenne est introduite afin de reproduire les observations expérimentales. En effet, lorsque la vitesse de coupe ou l'avance augmentent, la température tend à croître et ainsi, à réduire le coefficient de frottement, et les efforts de coupe. Pour toutes les conditions de coupe, un bon accord est observé entre la modélisation et les résultats expérimentaux pour l'acier AISI 1050

An experimental analysis of abrasive water jet engraving of Italian marbles / Analisi sperimentale del processo di marcatura su marmi italiani tramite getto d’acqua ad alta pressione con abrasivo

English: This article concerns characterizing and optimizing the process of water-jet engraving on stone materials through experimental analysis. The purpose is to find possible relationships between work parameters for an abrasive water-jet and the geometrical parameters created by grooves. Samples of White Carrara and Perlato of Coreno marbles were used in testing. An optical profilometer was used to measure the transversal profile of the groove, objectively characterized by a number of measurements described in the article, including two parameters of visual quality. Statistical analysis made it possible to indicate optimal settings to enter on the basis of desired results; for example, increases in width, depth or the degree of groove contrast. Italian: Questo articolo affronta la caratterizzazione e ottimizzazione del processo di incisione di materiali lapidei mediante water jet attraverso un’analisi sperimentale. La finalità è trovare possibili relazioni tra parametri impostati per la lavorazione, tramite idrogetto con abrasivo, e parametri geometrici ricavati dai solchi. Per questo studio sono stati analizzati dei campioni di marmo Bianco di Carrara e di Perlato di Coreno. Per mezzo di un profilometro ottico è stato possibile misurare il profilo trasversale del solco, caratterizzato in maniera oggettiva tramite alcune misure descritte nell’articolo, inclusi due parametri di qualità visiva. Attraverso un’analisi statistica è stato possibile indicare le impostazioni ottimali da settare in base al risultato desiderato: es. aumento della larghezza, profondità o livello di contrasto del solco

Analysis of adiabatic shear banding in orthogonal cutting of Ti alloy

This work is focused on the numerical analysis of adiabatic shear banding in orthogonal cutting of Ti6Al4V alloy. Segmented chip results from adiabatic shear banding, depending on the competition of thermal softening and strain and strain rate hardening. The influence of cutting velocity and feed in the chip segmentation is studied. Also the role of friction at the tool-chip interface and the effect of rheological parameters of the constitutive equation are analyzed. Experimental tests obtained from previous work of the authors [Molinari A, Musquar C, Sutter G, Adiabatic shear banding in high speed machining of Ti-6Al-4V experiments and modeling, Int J Plast, vol. 18, 2002, p. 443-4591 and others were used as a reference to validate the models. Cutting forces and the mechanism of plastic flow localization are analyzed in terms of frequency of segmentation and shear band width and compared to experimental data.The financial support of this work to the Ministry of Economy and Competitiveness of Spain with the project DPI2011-25999 and to the Universidad Carlos III de Madrid —Banco de Santander for the program "Chair ofExcellence". This work was also supported by the French State through the program “Investmentin the future” operated by the NationalResearch Agency (ANR) and referenced byLabEx DAMAS.Publicad

Silicone-coated non-woven polyester dressing enhances reepithelialisation in a sheep model of dermal wounds

Negative-pressure wound therapy (NPWT) also known as V.A.C. (Vacuum-assisted closure), is widely used to manage various type of wounds and accelerate healing. NPWT has so far been delivered mainly via opencell polyurethane (PU) foam or medical gauze. In this study an experimental setup of sheep wound model was used to evaluate, under NPWT conditions, the performance of a silicone-coated non-woven polyester (N-WPE) compared with PU foam and cotton hydrophilic gauze, used as reference materials. Animals were anesthetized with spontaneous breathing to create three 3 9 3 cm skin defects bilaterally; each animal received three different samples on each side (n = 6 in each experimental group) and was subjected to negative and continuous 125 mmHg pressure up to 16 days. Wound conditions after 1, 8 and 16 days of treatment with the wound dressings were evaluated based on gross and histological appearances. Skin defects treated with the silicone-coated N-WPE showed a significant decrease in wound size, an increase of re-epithelialization, collagen deposition and wound neovascularisation, and a minimal stickiness to the wound tissue, in comparison with gauze and PU foam. Taken all together these findings indicate that the silicone-coated N-WPE dressing enhances wound healing since stimulates higher granulation tissue formation and causes minor tissue trauma during dressing changes

SeaClouds: An Open Reference Architecture for Multi-Cloud Governance

A. Brogi, J. Carrasco, J. Cubo, F. D'Andria, E. Di Nitto, M. Guerriero, D. Pérez, E. Pimentel, J. Soldani. "SeaClouds: An Open Reference Architecture for Multi-Cloud Governance". In B. Tekinerdogan et al. (Eds.): ECSA 2016, LNCS 9839, pp. 334–338, 2016.We present the open reference architecture of the SeaClouds solution. It aims at enabling a seamless adaptive multi-cloud management of complex applications by supporting the distribution, monitoring and reconfiguration of app modules over heterogeneous cloud providers.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech