Sainte-Foy-lès-Lyon, France
Sainte-Foy-lès-Lyon, France

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Cheng I.,University of Alberta | Shen R.,University of Alberta | Moreau R.,Ampere Laboratory | Brizzi V.,Bordeaux Regional Hospital | Basu A.,University of Alberta
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014 | Year: 2014

Endovascular surgery is performed by placing a catheter through blood vessels. Due to the fragility of arteries and the difficulty in controlling a long elastic wire to reach the target region, training plays an extremely important role in helping a surgeon acquire the required complex skills. Virtual reality simulators and augmented reality systems have proven to be effective in minimally invasive surgical training. These systems, however, often employ pre-captured or computer-generated medical images. We have developed an augmented reality system for ultrasound-guided endovascular surgical training, where real ultrasound images captured during the procedure are registered with a pre-scanned phantom model to give the operator a realistic experience. Our goal is to extend the planning and training environment to deliver a system for computer assisted remote endovascular surgery where the navigation of a catheter can be controlled through a robotic device based on the guidance provided by an endovascular surgeon. © 2014 IEEE.

Arnal E.,Sherpa Engineering Company | Anthierens C.,Institute of Movement science UMR 6233 | Bideaux E.,AMPERE Laboratory
IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM | Year: 2011

This paper presents recent investigations on modeling and control of the luminous atmosphere in buildings. The luminous atmosphere desired by the occupants is defined by the amount and the distribution of light entering the room. These criteria reflect the mean optic state of the room. In tertiary building, the rooms generally have several artificial and natural light sources, this is why the light controller developed here is based on an optimization method to determine the best distribution of light flows among all the sources. The optimal solution is computed by considering various goals like minimizing the energy consumption. In this paper, the authors present a new extension of the luminous atmosphere controller that prevents glare caused by the daylight from occurring in the room. Detection of outdoor dazzling sources is performed by a fisheye video camera fixed on the building envelope. A numerical method is then used to determine the areas of potential glare within the room and to define operating limits on actuators in order to reject them. To show the impact of glare rejection on the luminous atmosphere controller, the authors have simulated the control in a room equipped with automated Venetian blinds and lights during a whole day. © 2011 IEEE.

El Falahi K.,Ampere Laboratory | Allard B.,Ampere Laboratory | Tournier D.,Ampere Laboratory | Bergogne D.,Ampere Laboratory
2010 6th International Conference on Integrated Power Electronics Systems, CIPS 2010 | Year: 2011

This paper presents the experimental characterization of commercial SOI MOSFET drivers from room temperature to 200°C and beyond. Parameters such as current amplitude, delay time, rise time and fall time of the output waveforms of the drivers are monitored. The test results will be discussed, and will help produce the specifications of an integrated SOI-based driver with the necessary functionality to drive an inverter up to 220°C ambient temperature. © VDE VERLAG GMBH.

Mrad R.,STMicroelectronics | Pillonnet G.,University Claude Bernard Lyon 1 | Morel F.,CNRS Ampere Laboratory | Vollaire C.,Ampere Laboratory | Nagari A.,STMicroelectronics
IEEE Transactions on Power Electronics | Year: 2015

Class-D audio amplifiers are switching circuits that produce serious Electromagnetic (EM) emissions and disturb the surrounding electronics. In order to reduce these emissions, electromagnetic compatibility (EMC) filters with ferrite beads are used. However, ferrite beads contain magnetic materials that have a nonlinear behavior. Thus, they have an unfavorable impact on the system audio quality. The common ferrite bead models do not take into account nonlinear phenomena. Thus, to predict the impact on the signal quality, this paper models the ferrite bead using the Jiles-Atherton magnetic material theory. The presented model provides the designers with a tool to quantify the effect of EMC filters on the total harmonic distortion (THD) of audio amplifiers. The simulated and measured results show that the tested ferrite bead have a negative effect on the audio signal for a wide range of amplitudes and can increase the THD up to 37 dB. Finally, this paper highlights the impact of the magnetic material type on the audio distortion by simulating the same component with different types of materials. © 1986-2012 IEEE.

Ducharne B.,CNRS Laboratory of Electrical Engineering and Ferroelectricity | Garbuio L.,Grenoble Institute of Technology | Lallart M.,CNRS Laboratory of Electrical Engineering and Ferroelectricity | Guyomar D.,CNRS Laboratory of Electrical Engineering and Ferroelectricity | And 2 more authors.
IEEE Transactions on Power Electronics | Year: 2013

Applications of piezoelectric actuators have increased dramatically during the past few decades. However, the capacitive nature of such devices makes their use delicate, especially in terms of power supply, as the instantaneous power may be much greater than the average effective power. This paper places particular focus on the description of a nonlinear technique for piezoelectric actuator control. This technique enables us to significantly increase the energy transfer efficiency of the device by reducing the reactive part of the power. Such an approach has the inverse effect of the well-known synchronized switch damping technique developed to reduce vibrations in smart structures. The proposed solution consists in disconnecting the driving voltage source from the piezoelectric element and switching the system to a passive electrical network at each occurrence of a voltage extremum. This switching strategy is designed to annihilate the reactive energy supplied by the voltage source and to decrease the active energy while ensuring a constant output power. Suppressing the reactive energy is particularly interesting for limiting the dimensions and energy requirements of power supplies. Compared to classical methods, the direct supply of both simulations and experimental validations has demonstrated the effectiveness of the proposed technique for eliminating all of the reactive energy and reducing the active power at frequencies close to the resonant one, while maintaining similar mechanical performances. © 2012 IEEE.

Branca X.,STERICSSON | Allard B.,Ampere Laboratory | Allard B.,INSA Lyon | Lin-Shi X.,Ampere Laboratory | And 2 more authors.
IEEE Transactions on Power Electronics | Year: 2013

Listening music with a headset is now a classical feature of mobile phones. A linear amplifier is still employed to drive the headset as the audio quality must challenge dedicated audio players with somewhat 100 dB of signal-to-noise ratio. This feature must also have the lowest impact on the platform autonomy, size, and cost. A symmetrical power supply is required by such audio amplifiers due to the standard jack connector of headsets. Using an inductive switch mode power supply (SMPS) is the most energy efficient solution to supply audio amplifiers from a battery. Classically, two dc/dc converters are employed to generate the required two symmetrical supply rails from a standard Lithium-Ion battery. It is at the cost of numerous bulky and expensive external components. A solution to reduce the number of external passive components is to consider a single-inductor, bipolar-outputs, (SIBO) dc/dc converter. An early prototype of such a converter has been realized on a 130-nm silicon process and offers primary results, nonoptimal but promising. The feedback control structure is studied based on a small signal model that serves to define the pairing of the loops for designing a decentralized controller. A set of controllers is designed by a pole placement technique and transient performances are demonstrated on audio patterns thanks to a piecewise linear model of the converter. Eighty percent peak efficiency is measured with the primary demonstrator but latter simulation results yield an expected improvement to 90%. The audio specifications appear very constraintful and the proposed SMPS does not meet entirely the latter figures. Limitations are detailed. However, many other applications can benefit from the proposed SIBO dc/dc converter. © 2012 IEEE.

Lahyani A.,MMA Laboratory | Venet P.,AMPERE Laboratory | Guermazi A.,University of Sfax | Troudi A.,University of Sfax
2012 1st International Conference on Renewable Energies and Vehicular Technology, REVET 2012 | Year: 2012

This work presents the study of the reduction in battery stresses by using supercapacitors (SC's) in a 500 kVA rated UPS. We aim at investigating the optimal SC-battery combination versus the SC's cost. This investigation is threefold; first, supercapacitors and battery models developed using Matlab/Simulink® are presented and validated. Second, the architecture and the simulation of the designed system combining the two types of storage devices are shown. The study emphasizes on UPS autonomous running for grid faults lasting few minutes, the supercapacitors supply the transient demand of power and the battery is responsible for the smoothness requirement of energy. Third, extensive simulations are carried out to determine the gain in battery RMS current, the gain in energy losses, the energy efficiency and the elimination rate of surge load power. These four performance parameters are determined by simulation and then analyzed. They reflect the potential decrease in battery stresses due to the SC's. A thorough analysis involving optimal study proposes to draw the optimal SC's number and filter constant from the variation of the aforementioned parameters versus the cost of the SC's. © 2012 IEEE.

Ghanes M.,ENSEA Cergy | Trabelsi M.,Qatar University | Lin-Shi X.,Ampere Laboratory | Barbot J.-P.,ENSEA Cergy | And 3 more authors.
International Journal of Robust and Nonlinear Control | Year: 2014

As capacitor voltages are necessary for the three-cell DC-DC chopper control, the estimation of such voltages by an observer is attractive solution in terms of cost. However, due to the hybrid behavior of this structure, the capacitor voltages may be partially or even not observable for a given switching configuration. In other words, the observability matrix associated to the capacitor voltages never has a full rank. In order to make the observer conceivable, this paper proposes a new design by establishing sufficient conditions under which the capacitor voltages can be reconstructed within appropriate specific switching sequence and not necessarily instantly. An interconnected high gain observer is then designed for the considered structure. Furthermore, the analysis of convergence is given according to specific switching sequence, and the bounds of the observer tuning parameters are numerically verified. A significant load current benchmark including a three-cell chopper is used as prototype to show the performance and the effectiveness of the proposed observer. Copyright © 2013 John Wiley & Sons, Ltd.

Hamad H.,Ampere Laboratory | Raynaud C.,Ampere Laboratory | Bevilacqua P.,Ampere Laboratory | Tournier D.,Ampere Laboratory | And 2 more authors.
Applied Physics Letters | Year: 2014

Using a pulsed green laser with a wavelength of 532 nm, a duration pulse of ∼1 ns, and a mean power varying between 1 and 100 mW, induced photocurrents have been measured in 4H-SiC bipolar diodes. Considering the photon energy (2.33 eV) and the bandgap of 4H-SiC (3.2 eV), the generation of electron-hole pair by the conventional single photon absorption process should be negligible. The intensity of the measured photocurrents depends quadratically on the power beam intensity. This clearly shows that they are generated using two-photon absorption process. As in conventional OBIC (Optical Beam Induced Current), the measurements give an image of the electric field distribution in the structure under test, and the minority carrier lifetime can be extracted from the decrease of the photocurrent at the edge of the structure. The extracted minority carrier lifetime of 210 ns is consistent with results obtained in case of single photon absorption. © 2014 AIP Publishing LLC.

Redondo-Iglesias E.,IFSTTAR LTE | Redondo-Iglesias E.,AMPERE Laboratory | Venet P.,University Claude Bernard Lyon 1 | Pelissier S.,IFSTTAR LTE
2015 10th International Conference on Ecological Vehicles and Renewable Energies, EVER 2015 | Year: 2015

This paper presents a methodology for modelling the capacity loss of Lithium ion cells in accelerated ageing tests. We have considered the state-of-charge drift during calendar ageing tests due to irreversible capacity losses. © 2015 European Union.

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