Nonparametric Laguerre estimation in the multiplicative censoring model

International audienceWe study the model $Y_i=X_iU_i, \; i=1, \ldots, n$ where the $U_i$'s are {\em i.i.d.} with $\beta(1,k)$ density, $k\ge 1$, the $X_i$'s are {\em i.i.d.}, nonnegative with unknown density $f$. The sequences $(X_i), (U_i),$ are independent. We aim at estimating $f$ on ${\mathbb R}^+$ from the observations $(Y_1, \dots, Y_n)$. We propose projection estimators using a Laguerre basis. A data-driven procedure is described in order to select the dimension of the projection space, which performs automatically the bias variance compromise. Then, we give upper bounds on the ${\mathbb L}^2$-risk on specific Sobolev-Laguerre spaces. Lower bounds matching with the upper bounds within a logarithmic factor are proved. The method is illustrated on simulated data

Mise en place d’un réseau EtherCAT pour un système de contrôle d’ascenseur

National audienceL'initiative d'introduire un réseau de terrain au niveau de la nouvelle génération des ascenseurs doit apporter une évolution majeure en terme de sûreté de fonctionnement et de maintenance. L'aspect innovant de ce projet est le fait d'introduire une hiérarchie dans la chaine de sécurité à travers l'architecture maître/esclaves, avec un temps de réponse assez réduit et de proposer des capacités d'adaptation rapide aux exigences de la norme ( 3 boîtiers de contrôles sont désormais imposés dans le fond de fosse)

Sobolev-Hermite versus Sobolev nonparametric density estimation on R

International audienceIn this paper, our aim is to revisit the nonparametric estimation of f assuming that f is square integrable on R, by using projection estimators on a Hermite basis. These estimators are defined and studied from the point of view of their mean integrated squared error on R. A model selection method is described and proved to perform an automatic bias variance compromise. Then, we present another collection of estimators, of deconvolution type, for which we define another model selection strategy. Considering Sobolev and Sobolev-Hermite spaces, the asymptotic rates of these estimators can be computed and compared: they are mainly proved to be equivalent. However, complexity evaluations prove that the Hermite estimators have a much lower computational cost than their deconvolution (or kernel) counterparts. These results are illustrated through a small simulation study

Développement d'un réseau de capteurs sans fils permettant une solution embarquée de géolocalisation -Application aux glissements de terrain

International audienceLa recherche dans le domaine des capteurs est en train de vivre une révolution importante, ouvrant des perspectives d'impacts significatifs dans de nombreux domaines comme le contrôle et la préservation de l'environnement ; les catastrophes naturelles sont de plus en plus fréquentes et sont à l'origine de préjudices socio-économiques souvent graves et coûteux. La prévision de ces risques, notamment en ce qui concerne les glissements de terrain, est dès lors indispensable. Notre objectif est d'instrumenter les versants instables avec un maillage de capteurs actifs dans le but de suivre en continu toute déformation. Ces réseaux possèdent souvent des ressources limitées en énergie, ce qui impose l'utilisation des protocoles et technologies de communication (Wifi, Zigbee, LoRa …) de façon à consommer une énergie minimale

La sécurité des ascenseurs avec des communications Ethernet-Based Real-Time

National audiencel'évolution des systèmes de contrôle industriels tendent vers des infrastructures de plus en plus connectées, ce qui les rendent plus dépendantes de réseaux et de protocoles de communication utilisés. Plusieurs travaux existants se sont focalisés sur la fiabilité de ces systèmes et la robustesse de leurs modèles de contrôle en cas de pannes ou de dysfonctionnement. Ces travaux n'ont pas considéré l'aspect réseau qui est devenu un vecteur d'attaque important étant donné l'utilisation de protocoles de communication pour l'échange des informations entre les équipements. Les conséquences de ces attaques, parfois deviennent extrêmement dévastatrices. En effet, récemment ces réseaux sont devenus la cible de plusieurs attaques en exploitant des vulnérabilités présentes dans les couches logicielles ou protocolaires de leurs équipements. Dans le cadre de la nouvelle génération de commande de l'ascenseur, un cas de transition sera analysé à partir d'un composant électrique/électrotechnique au réseau de composants électroniques communiqués dans le cadre de la sécurité du système de déplacement d'un ascenseur. La proposition repose sur la sécurité des modules IP interconnectés entre eux, qui supportent un protocole temps réel industriel (Powerlink, EtherCat et Sercos). Cette proposition représente un des démonstrateurs du projet collaboratif avec un noyau déterministe sûr de fonctionnement par construction

New lift safety architecture to meet PESSRAL requirements

ISBN : 978-1-4799-8171-7International audienceAs part of new lift control generation, we will analyze a transition case from an electrical/electro-mechanical components to a networked control system. The main element we focus on in the lift system is the safety chain. This paper will describe the analysis of dependability requirements (IEC 61508) for the next electronic lift control

Performance analysis of Ethernet Powerlink protocol: Application to a new lift system generation

International audienceTo ensure control, present lifts use the Controller Area Network (CAN) bus for transmitting commands between components. Although it is largely adopted in the industrial process, CAN is not able to guarantee a sufficient throughput to transmit multimedia data or to meet the requirements of some safety standards. In this paper, we present a transition case from electrical/electromechanical components to a networked control system. The main element we focus on in the lift system is the safety chain. We propose to build the lift communication system around real-time Ethernet for more efficiency, smartness and safety. Furthermore, the use of the openSAFETY protocol as a safety layer over the real-time Ethernet allows the achievement of the required Safety Integrity Level (SIL). This adopted solution should meet the adopted standard IEC 61508 requirements

Port-Hamiltonian model and load balancing for DC-microgrid lift systems

This paper considers the problem of modeling a multi-source lift system where power balancing-realized through a power DC bus-should be optimally controlled. The system includes the mechanical part, a Salient Permanent Magnet Synchronous Machine (SPMSM), a battery energy storage unit, a super-capacitor, a solar panel (PV) generation unit as well as the corresponding converters to DC-links. This microgrid is connected to a three-phase utility (external) grid. A port-Hamiltonian model is proposed for the system. It includes the descriptions of nonlinear characteristics and the limitations for each components as well as some typical operation demands. Then, different optimization objectives are formulated in view of an efficient energy management within the microgrid system

Towards unified tooling for easing the qualification of medical normed environments

International audienceMedical confined environments are characterized by a very stringent set of standards and regulations, depending on a wide range of parameters. These are very difficult to handle because of the lack of appropriate tools to qualify before use, monitor during use and audit after use. Providing these tools requires to tackle the complexity of gathering all the different elements of the environment profile (building topology, standards and rules, instrumentation) in a single model which could be statically validated and dynamically checked against events. This article both focuses on introducing the context of medical confined environment regulation and issues faced when trying to design and implement qualification and monitoring tools, and on presenting the approach and work in progress

PLC sensor IPv6 networking interoperabe with WSN

International audienceTechnology evolution have made possible to connect all kind of devices to IP network. This becomes an evident objective for sensors networks research. In this paper, we investigate the possibility of using IPv6 for sensor networks connected through powerline communication (PLC) non-wireless mediums and demonstrate possible interoperability. Our work is based on the adaptation of the IEEE 802.15.4 standard protocol. It is constrained by the low-power, lossy and low data-rate context of powerline transceiver that uses pulse modulation. Our aim is to provide interoperability features regarding others mediums with a robust and reliable communication stack for smart metering, home control or home area networks applications. This document propose the first adaptation of the IEEE 802.15.4 commons standard on PLC medium. Following this standard interface, we demonstrate the possibility to carry out data on PLC with great reliability, and low power energy requirement using our WPCTMphysical layer (standing for Watt Pulse Communication (WPC)). Relying on this adaptation, we then focus on the convergence of the IPv6 protocol at the network level, with the 6LoWPAN adaptation. We also present our initial implementation of the RPL setup and routing protocol. This allows for a full network layer stack and results in efficient routing in our low power, low data-rate and lossy network context. Thus, we finally demonstrate interoperability with a real testbed between powerline and wireless sensor networks running IEEE 802.15.4/6LoWPAN/IPv6/RPL stacks. We conclude about the interest of such interoperability for the real usage of sensor networks with a feedback from field's applications deployment and our future work