Thales (Belgium)

Multiphase machines are well known for their fault-tolerant capability. Star-connected multiphase machines have fault tolerance in an open circuit. For an inverter switch short-circuit fault, it is possible to keep a smooth torque of a permanent magnet synchronous machine if the currents of the faulty phases are determined and their values are acceptable. This paper investigates fault-tolerant operations of an open-end five-phase drive, i.e., a multiphase machine fed with a dual-inverter supply. Inverter switch short-circuit fault is considered and handled with a simple solution. Original theoretical developments are presented. Simulation and experimental results validate the proposed strategy.

NOMAD is a spectrometer suite on board ESA's ExoMars trace gas orbiter due for launch in January 2016. NOMAD consists of two infrared channels and one ultraviolet and visible channel allowing the instrument to perform observations quasi-constantly, by taking nadir measurements at dayside and nightside, and during solar occultations. In this paper, the design, manufacturing, and testing of the two infrared channels are described. We focus upon the optical working principle in these channels, where an echelle grating, used as a diffractive element, is combined with an acousto-optical tunable filter, used as a diffraction order sorter.

Abstract Signal and image processing applications require a lot of computing resources. For low-volume applications like in professional electronics applications, FPGA are used in combination with DSP and GPP in order to reach the performances required by the product roadmaps. Nevertheless, FPGA designs are static, which raises a flexibility issue with new complex or software defined applications like software-defined radio (SDR). In this scope, dynamic partial reconfiguration (DPR) is used to bring a virtualization layer upon the static hardware of FPGA. During the last decade, DPR has been widely studied in academia. Nevertheless, there are very few real applications using it, and therefore, there is a lack of feedback providing relevant issues to address in order to improve its applicability. This paper evaluates the interest and limitations when using DPR in professional electronics applications and provides guidelines to improve its applicability. It makes a fair evaluation based on experiments made on a set of signal and image processing applications. It identifies the missing elements of the design flow to use DPR in professional electronics applications. Finally, it introduces a fast reconfiguration manager providing an 84-time improvement compared to the vendor solution.

This paper provides a detailed description of the Energetic Particle Telescope (EPT) accommodated on board the PROBA-V satellite launched on May 7th, 2013 on a LEO, 820 km altitude, 98.7 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> inclination and a 10:30-11:30 Local Time at Descending Node. The EPT is an ionizing particle spectrometer that was designed based on a new concept and the most advanced signal processing technologies: it performs in-flight electron and ion discrimination and classifies each detected particle in its corresponding physical channels from which the incident spectrum can be readily reconstructed. The detector measures electron fluxes in the energy range 0.5-20 MeV, proton fluxes in the energy range 9.5-300 MeV and He-ion fluxes between 38 and 1200 MeV. The EPT is a modular configurable instrument with customizable maximum energy, field of view angle, geometrical factor and angular resolution. Therefore, the features of the currently flying instrument may slightly differ from those described in past or future configurations. After a description of the instrument along with the data acquisition and analysis procedures, the first particle fluxes measured by the EPT will be shown and discussed. The web-site located at http://web.csr.ucl.ac.be/csr_web/probav/ which daily displays measured fluxes and other related studies will also be briefly described.

This paper analyzes two fault-tolerant dual-multiphase motor drives, a series-connected topology, and a standard H-bridge topology. Previous studies have shown that the series connected topology is appropriate to an aerospace application and has lower peak current in degraded mode in comparison with the H-bridge topology, which may consequently diminish the system's weight and cost. This paper extends the study to compare different control strategies of these structures under two fault conditions: short-circuit of an inverter's switch and an open-phase of the machine. The control strategies analyzed in this paper do not impact the fundamental current or the torque generation, but the amplitudes of some harmonics in degraded mode are expected to be narrowed down in order to reduce the inverter's size. Some analyses of maximum voltage and peak current in degraded mode have been used for inverter dimensioning. Experimental results are shown and compared to the simulated ones to confirm the validity of this study.

Iontophoresis is a process which enhances skin permeation of ionized species by using an electrical field as driving force. The aim of the present study was to investigate whether transdermal iontophoresis of fentanyl or sufentanil could induce therapeutic plasma levels and antinociceptive effect. Fentanyl and sufentanil were introduced in an acidic buffer (acetate buffer 0.01 M at pH 5) at 40 micrograms/mL. A platinum electrode was clamped in an hydrophilic foam soaked with the drug solution and linked to the anode. A cathodic foam reservoir was filled with saline solution. The device was applied on the abdominal skin of hairless rats and direct current (0.17 mA/cm2) was applied for 1 h. Opioid plasma concentrations were monitored. In the experimental conditions used, iontophoresis strongly increased transdermal permeation of the drugs as compared to diffusion. A 1.5 h Tmax was observed. The maximal plasma levels after 1.5 h were 29.3 +/- 14 ng/mL for fentanyl and 29.1 +/- 14 ng/mL for sufentanil. The plasma level of the narcotics decreased slowly after iontophoresis was terminated. Iontophoretic transdermal permeation of fentanyl and sufentanil in rats induced analgesic effects as measured by the tail-flick test. These effects lasted for about 4 h. Thus, transdermal iontophoresis with a miniaturized device is effective for the controlled and pulsatile or sustained delivery of synthetic opiates for pain management in humans. As compared to classical patches, it could reduce the lag time before reaching steady state and allow variable drug release rate.

A fast full-wave scheme is presented for the analysis of large printed antenna arrays, making use of the macrobasis functions (MBFs) technique. The interaction between MBFs is computed efficiently through a combination of the contour-fast Fourier transform (C-FFT) and interpolatory MBF-based techniques, which effectively deal with different parts of the printed structure. Substantial improvement is introduced to C-FFT by adding up the FFT tables before interpolating, which dramatically reduces the memory required to store the tables and accelerates the method-of-moment matrix filling time. The current on the antenna array and embedded element patterns (EEPs) are then rapidly obtained. Furthermore, an optimization method relying on sequential convex optimization and the fast full-wave scheme is proposed for the array synthesis. At each optimization iteration, EEPs are precomputed and assumed to be locally constant, which enables the implementation of convex programming to rapidly optimize the antenna positions. The EEPs are then quickly updated for the new antenna positions. The scheme enables the efficient inclusion of mutual coupling in array synthesis problems. Numerical results are presented and discussed for the synthesis of linear and planar arrays made of printed bowtie antennas.

A recent synthesis paradigm for tailoring the far-field radiation of leaky wave (LW) radiating metasurface (MTS) antennas is reviewed and experimentally validated. The considered antennas are realized with electrically small patches printed on a planar grounded dielectric slab. The patch layer is modeled as an impedance sheet whose spatial variation is initially designed to provide the desired LW effect from a prespecified surface wave (SW) excitation.

The extracellular matrix (ECM), composed of interlinked proteins outside of cells, is an important component of the human body that helps maintain tissue architecture and cellular homeostasis. As people age, the ECM undergoes changes that can lead to age-related morbidity and mortality. Despite its importance, ECM aging remains understudied in the field of geroscience. In this review, we discuss the core concepts of ECM integrity, outline the age-related challenges and subsequent pathologies and diseases, summarize diagnostic methods detecting a faulty ECM, and provide strategies targeting ECM homeostasis. To conceptualize this, we built a technology research tree to hierarchically visualize possible research sequences for studying ECM aging. This strategic framework will hopefully facilitate the development of future research on interventions to restore ECM integrity, which could potentially lead to the development of new drugs or therapeutic interventions promoting health during aging.

Depletion mode insulated gate AlGaN/GaN power switching HEMTs were evaluated for stability under heavy-ion irradation. Experiments were performed for different types of heavy-ion species, values of gate bias, drain bias, and device geometry. For the insulated gate AlGaN/GaN devices, an as-of-yet unobserved single-event occurred, which we have termed single-event switching (SES). These SES events occurred next to previously observed single-event gate rupture (SEGR) events. It was found that the SES events were gate leakage dependent and stopped occurring above a certain threshold value of gate leakage. Statistical analysis showed that the cross section for single SES events exhibited a lognormal distribution with a median value close to the gate area, and the capture cross section exhibited a slight voltage dependence. The gate leakage after irradiation, on the other hand, was exponentially distributed and was strongly voltage and geometry dependent, indicating an electric field dependency.

MEX Experience Module is a part of CARMEN2 instrument launched in June 22 2008 aboard JASON2 satellite. This scientific instrument is dedicated to the study of the effects of space radiation environment on various electronic devices. Among all the phenomena studied in this experiment, this paper focuses on the data collected on destructive SEEs: Latch-up on commercial SRAMs and Burnout on power MOSFETs.

This paper is concerned with the numerical simulation of mechanical structures subjected to pyroshocks. In practice, the methodology is applied on the pyroshock test facility, which is used by Thales to qualify the electronic equipment intended to be embarked onboard of spatial vehicles. This test facility involves one plate or two plates linked by screw bolts. The tested device is mounted on one side while the explosive charge is applied on the other side. The main issue of this work is to be able to tune, by simulation, the parameters of the facility (number of plates, material of plate, number of bolts, amount of explosive, etc.) so as to get the required level of solicitation during the test. The paper begins by an introduction presenting the state of the art in terms of pyroshock modeling, followed by a description of the shock response spectrum (SRS) commonly used to represent the test specifications of an embarked equipment. It turns out that there is a lack of computational techniques able to predict the dynamic behavior of complex structures subjected to high frequency shock waves such as explosive loads. Three sections are then devoted to the simulation of the pyrotechnic test, which involves on one hand a model of the structure and on the other hand an appropriate representation of the impulsive load. The finite element method (FEM) is used to model the dynamic behavior of the structure. The FEM models of several instances of the facility have been updated and validated up to 1000Hz by comparison with the results of experimental modal analyses. For the excitation source, we have considered an approach by equivalent mechanical shock (EMS), which consists in replacing the actual excitation by a localized force applied on the FEM model at the center of the explosive device. The main originality of the approach is to identify the amplitude and duration of the EMS by minimizing the gap between the experimental and numerical results in terms of the SRS related to several points of the facility. The identification has been performed on a simple plate structure for different amounts of explosive. The methodology is then validated in three ways. Firstly, it is shown that there is a good agreement between experimental and numerical SRS for all the points considered to identify the EMS. Secondly, it appears that the energy injected by the EMS is well correlated with the amount of explosive. Lastly, the EMS identified on one structure for a given amount of explosive leads to coherent responses when applied on other structures. A parametric study is finally performed, which shows the influence of the thickness of the plate, the material properties, the localization of the EMS, and the addition of a local mass. The different obtained results show that our pyroshock model allows to efficiently estimate the acceleration levels undergone by the electronic equipment during a pyroshock and, in this way, to predict some eventual electrical failures, such as the chatter of electromagnetic relays.

The present paper describes several technological topics featured in a new prototype of anode/beam supply for 5 kW Power Processing Unit (PPU), dedicated to be compatible with many thruster types and operating modes thanks to a configurable output stage and wide output voltage range. The achievements in terms of power density and cost reduction are attributed to a new electrical topology (Dual Active Bridge) allowing better current form factor and hence lower losses, but also to wide-bandgap semiconductors and to a new, high-power, high-voltage transformer. A versatile digital control has been implemented to be compatible with all output configurations and to use additional degree of freedom in the control loop to minimize certain losses.

Athough side-channel attacks appeared more than two decades ago, they remain very little discussed by security professionals outside the academia or very specific sectors (e.g., smartcard industry, governments). However, with the increasing generalisation of Internet of Things systems, they are a threat that can no longer be ignored by the operational world. This work aims to demonstrate that side-channel attacks can be practically achieved by an attacker, with reasonable means, effort, knowledge, and time. For this purpose, the contribution of this work is twofold. First, it is shown how a side-channel attack setup exploiting power leakages through electro-magnetic radiations, and making use of general-purpose and affordable equipment, can be built. The acquisition of attack power traces is made thanks to a Red Pitaya STEMlab platform coupled with a home-built radio front-end. Second, it is shown how an attack can be conducted against targets that are representative of Internet of Things devices: 8-bit and 32-bit Arduino boards.

This paper describes analytical and simulation tools to analyze the effects of Open Switch Fault (OSF) and Open Phase Fault (OPF) on five-phase PMSM designed for aerospace applications. For such applications, the fault tolerance and the reliability of the drive (PMSM and the power converter) are important to take into account for design. The addressed work aims essentially to analyze the dynamic of the measured phase currents in post-fault operation with a real-time fault diagnostic purpose in the VSI. The paper starts with a presentation of the electric drive system structure and its control used in pre-fault and post-fault operation. Then, fault effects analysis (FEA) on the system will be considered. All results are verified analytically and through simulation software using Matlab/Simulink®. The theoretical development and the simulation results show that the five-phase PMSM under inverter faults presents typical characteristics which can be used as better input variables for designing a high performance real-time fault diagnostic and classification process.

Abstract High-density interconnect (HDI) printed circuit boards (PCBs) and associated assemblies are essential to allow space projects to benefit from the ever increasing complexity and functionality of modern integrated circuits such as field-programmable gate arrays, digital signal processors and application processors. Increasing demands for functionality translate into higher signal speeds combined with an increasing number of input/outputs (I/Os). To limit the overall package size, the contact pad pitch of the components is reduced. The combination of a high number of I/Os with a reduced pitch places additional demands onto the PCB, requiring the use of laser-drilled microvias, high-aspect ratio core vias, and small track width and spacing. Although the associated advanced manufacturing processes have been widely used in commercial, automotive, medical, and military applications, reconciling these advancements in capability with the reliability requirements for space remains a challenge. Two categories of the HDI technology are considered: two levels of staggered microvias (basic HDI) and (up to) three levels of stacked microvias (complex HDI). In this article, the qualification of the basic HDI technology in accordance with ECSS-Q-ST-70-60C is described. At 1.0-mm pitch, the technology passes all testing successfully. At .8-mm pitch, failures are encountered during interconnection stress testing and conductive anodic filament testing. These failures provide the basis for updating the design rules for HDI PCBs.

Herein, tunneling aluminum oxide (Al 2 O 3 ) passivation layers are demonstrated to be a candidate for hole collecting, passivating contacts when coupled with a boron‐doped surface. These very thin Al 2 O 3 films (1.5–3 nm) are deposited using spatial atomic layer deposition (ALD) on boron diffused (110–115 Ω □ −1 ) hydrophilic surfaces operating as metal–insulator–semiconductor (MIS) contacts. The emitter saturation current density values of ≈57 fA cm −2 are achieved for the Al 2 O 3 film thicknesses of 2 nm before metallization. At this same thickness, the contact resistivity values of 33 mΩ cm 2 are obtained after metallization. Most importantly, the boron diffusion, wet chemical surface preparation, and spatial ALD of Al 2 O 3 used to create these MIS structures are all performed with industrially relevant equipment on Cz wafers.

A monolithic Gallium-Nitride (GaN) Half Bridge with integrated gate drivers, floating supplies, level-shifters and a dead time control is presented. The design has been realized in a 200V Gallium-Nitride on Silicon-on-Isolator (GaN-on-SOI) technology with Deep Trench Isolation (DTI), using enhancement type high voltage and low voltage GaN devices. The power stage and analog/digital functionality are integrated on a single die. The resulting power module has been tested up to 10A loading and 5MHz switching frequency, achieving a peak power stage efficiency of 98.3%. The integrated gate drivers provide a delay matching within 2ns. This work successfully demonstrates the capabilities of GaN integrated circuits (IC) in power management applications. Moreover, it clears the path towards fully replacing pure Silicon (Si) or Si-GaN hybrid DC-DC converter modules with fully integrated monolithic GaN counterparts.

This paper deals with the fault effects analysis and diagnosis in 6-Φ PMSM designed for aerospace applications. The addressed work aims to analyze the features offered by the space vector theory applied to these systems for fault detection and identification purposes. The paper starts with a presentation of the overall electric drive system structure and its control. Then, fault effects analysis under faulty operation mode of the 6-leg voltage source inverter is presented considering the space vector theory. Based on such analysis, an accurate FDI process is designed for these applications. All results are verified analytically and through simulation software using Matlab/Simulink.

As the trend in reconfigurable electronics goes towards strong integration, FPGA devices are becoming more and more interesting. They are already used for safety-critical applications such as avionics (Hispano-Suiza, 2005). Latest FPGA's also enable new techniques such as dynamic partial reconfiguration (DPR), allowing new possibilities in terms of performance and flexibility. Their use in safety-critical systems is considered as impossible nowadays since they must be strictly validated, and DPR brings many new issues. Indeed, the tools used for DPR must be certified, which is barely impossible for the current DPR tools provided by the vendors. We have developed a simple flow upon the usual static one for Xilinx FPGA's that does not require any support of the vendor tools for DPR. This lessens the complexity of tools certification, and make a step towards enabling the certification of DPR for safety-critical applications. Moreover, under strong hypotheses, and by using safe design principles, we show how the complexity of certifying DPR can be reduced.