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Angers, France

Morel C.,ESEO Group | Rusu D.P.,Technical University of Cluj Napoca
Advances in Electrical and Computer Engineering | Year: 2011

This paper describes bifurcation phenomena of a photovoltaic system. The studied photovoltaic (PV) system includes a solar panel, a boost converter, a maximum power point tracking (MPPT) controller and a storage device. Computer simulations are performed to capture the effects of variation of some chosen parameters on the qualitative behavior of the system. The impact of the maximum power point (MPP) current and voltage variations due to luminosity changes is determinate, as well as the load variation. The stability of the system is analyzed using the state transition matrix over one switching cycle (the monodromy matrix) including the state transition matrices during each switching (the saltation matrices). This investigation is important to predict nonlinear phenomena and for the components dimensioning for a proper functioning. © 2011 AECE. Source

Beaudoux O.,ESEO Group | Blouin A.,French Institute for Research in Computer Science and Automation | Barais O.,University of Rennes 1 | Jezequel J.-M.,University of Rennes 1
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

Collections are omnipresent within models: collections of references can represent relations between objects, and collections of values can represent object attributes. Consequently, manipulating models often consists of performing operations on collections. For example, transformations create target collections from given source collections. Similarly, constraint evaluations perform computation on collections. Recent research works focus on making such transformations or constraint evaluations active (i.e. incremental, or live). However, they propose their own solutions to the issue by the introduction of specific languages and/or systems. This paper proposes a mathematical formalism, centered on collections and independent of languages and systems, that describes how the implementation of standard operations on collections can be made active. The formalism also introduces a reversed active assignment dedicated to bidirectional operations. A case study illustrates how to use the formalism and its Active Kermeta implementation for creating an active transformation. © 2010 Springer-Verlag. Source

Beaudoux O.,ESEO Group | Blouin A.,French Institute for Research in Computer Science and Automation | Barais O.,University of Rennes 1 | Jezequel J.-M.,University of Rennes 1
Proceedings of the 2011 SIGCHI Symposium on Engineering Interactive Computing Systems, EICS 2011 | Year: 2011

Modern GUI toolkits propose the use of declarative data bindings to link the domain data to their presentations. These approaches work fine for defining simple bindings, but require an increasing programming effort as soon as the bindings become more complex. In this paper, we propose the use of active operations for specifying and implementing UI data bindings to tackle this issue. We demonstrate that the proposed approach goes beyond the usual declarative data bindings by combining the simplicity of the declarative approaches with the expressiveness of active operations. Copyright 2011 ACM. Source

Ayed A.,ESEO Group | Dubois T.,University of Bordeaux 1 | Levant J.-L.,Atmel Corporation | Duchamp G.,University of Bordeaux 1
Microelectronics Reliability | Year: 2015

In this paper, the failure mechanism of an embedded analog-to-digital converter (ADC) is studied and its immunity modeling with regard to electromagnetic interferences is presented. Failure causes are identified based on off-chip immunity measurements and without specific knowledge of the ADC's design. Disturbances coupling paths inside the ADC have been recognized as well as the conversion error mechanism. Then, immunity of the ADC is modeled using the ICIM-CI (Integrated Circuit Immunity Model for Conducted Immunity) black-box modeling approach. We show the interest of using the direct power injection (DPI) measurement technique for both analyzing and modeling the immunity of complex integrated circuits. © 2015. Source

Doumiati M.,ESEO Group | Martinez J.,CNRS GIPSA Laboratory | Sename O.,CNRS GIPSA Laboratory | Dugard L.,CNRS GIPSA Laboratory | Lechner D.,MA Laboratory
Control Engineering Practice | Year: 2016

Road profile acts as a disturbance input to the vehicle dynamics and results in undesirable vibrations affecting the vehicle stability. An accurate knowledge of this data is a key for a better understanding of the vehicle dynamics behavior and active vehicle control systems design. However, direct measurements of the road profile are not trivial for technical and economical reasons, and thus alternative solutions are needed. This paper develops a novel observer, known as a virtual sensor, suitable for real-time estimation of the road profile. The developed approach is built on a quarter-car model and uses measurements of the vehicle body. The road roughness is modeled as a sinusoidal disturbance signal acting on the vehicle system. Since this signal has unknown and time-varying characteristics, the proposed estimation method implements an adaptive control scheme based on the internal model principle and on the use of Youla-Kučera (YK) parameterization technique (also known as Q-parameterization). For performances assessment, estimations are comparatively evaluated with respect to measurements issued from Longitudinal Profile Analyzer (LPA) and Inertial Profiler (IP) instruments during experimental trials. The proposed method is also compared to the approach provided in Doumiati, Victorino, Charara, and Lechner (2011), where a stochastic Kalman filter is applied assuming a linear road model. Results show the effectiveness and pertinence of the present observation scheme. © 2015 Elsevier Ltd. Source

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