Contact-less transfer of energy has always been a desired feature for systems that require reliable and durable power transfer across their moving parts. In rotary equipment in particular, slip-rings are the established solution with off-the-shelf and customised solutions readily available in the market. Despite the mature technology, slip-rings suffer wear and are prone to arcing, making frequent maintenance a necessity. In this project a rotating transformer is proposed as an alternative solution for contact-less transfer of energy across the revolving frame of an airborne electronic-scanning radar. This thesis is based on the hypothesis that the Phase-Shifted Full Bridge (PSFB) topology can efectively utilise the parasitic components of the rotating transformer to achieve efficient (over 90%) power conversion at the kW range. The first part of this work concentrates on the study of the magnetic interface and its electrical properties. Initially the magnetic structure of the transformer is studied in order to gain understanding of the effects of the physical layout of the component to its electrical behaviour. The problems of low magnetising and increased leakage inductance are quantified by measurements, calculations and finite element analysis. An accurate electrical model is built and used to calculate the transformer voltage and current gain. The second part of the research programme aims at the compilation of a design strategy for a PSFB incorporating a rotating transformer. An algorithm is presented, that optimises the magnetic component structure in order to achieve minimum switching losses and spread the conduction losses between the transformer and power switches. The last stage involves the evaluation of the design algorithm through prototyping and testing. Some topological variations are tested and compared with the original conventional PSFB converter. The thesis concludes with a discussion of the results and future challenges.

Detection and monitoring of the damage created by the corrosion of the steel reinforcement in concrete structures is a challenging and multidisciplinary problem. Economical monitoring strategy that is long-term and nondestructive requires low-cost, battery-free, wireless sensors. Our Electronic Structural Surveillance (ESS) platform uses battery-free passive resonant circuit (tag) as a sensor. The tag is magnetically coupled to an external reader coil. It is interrogated/read remotely in a non-contact (wireless) manner and the state of the sensor is determined from a swept frequency impedance measurement. When paired with the correct sensing element (transducer), the tag can be used for a variety of sensing applications for example, chemical & biochemical sensors. A circuit model of the reader and tag for such a universal battery-free wireless sensor platform is developed. The interaction between design and detection limit is examined. The dependence of the measured signal strength and read range on the various reader and tag circuit parameters is analyzed. Since the values of the circuit of the coils are dependent on their geometries, the effect of specific coil geometry is evaluated and design recommendations are made. / text

Bc. David Morávek Tyre temperature measurement on moving vehicle with of infrared pyrometer OS100 MT, IAE, 2008, page 70, picture 41 Problemacy of recording the temperature and tyre pressure on driven car is processed in this diploma work. Suitable measuring chain was set up. Censor holders for this type of measurement were designed and produced. Driving exams and tests are depicted in this work, too. We came to the conclusion that tyre temperature depends on lengthways and transverse acceleration of the car and also on it’s load.

Approved for public release, distribution is unlimited / In this thesis, a series of experiments were performed to characterize the material properties of InGaAs/GaAs for use in a two-color quantum-well IR photodetector (QWIP) design. Results from room temperature studies using cathodoluminescence and photoluminescence indicated light emission at 858 nm and 1019 nm from GaAs and InGaAs, respectively. Using a direct transport imaging technique, an edge dislocation pattern was observed and shown to be confined to the InGaAs layer of the material. A dislocation density measurement was performed and was shown to be less than 2000 lines/cm. Quantitative intensity level measurements indicated fluctuation in the region of dislocations to be less than 30% of the signal to background level. Finally, a spot mode study using the direct transport imaging method was performed to evaluate the feasibility of using this technique for contact-less diffusion length measurements. / Civilian, Department of Air Force

Ce travail de thèse décrit l’application de méthodes d’analyse innovantes à la caractérisation des propriétésmécaniques et électriques de matériaux composites.Le Chapitre premier dresse un état de l’art des fondamentaux théoriques et pré requis nécessaires à lacompréhension du manuscrit. Un regard critique permet de dégager une stratégie pour l’analyse, basée d’une partsur des méthodes holographiques numériques et d’autre part sur des techniques de mesure diélectrique.Le Chapitre second est dédié au choix de la méthode d’holographie numérique. En particulier, la configurationimage montre quelques particularités qui sont analysées en détail : le rôle du diaphragme d'ouverture du systèmed'imagerie. Nous concluons que la méthode d’holographie de Fresnel présente des avantages d’achromatismepour les applications avec plusieurs longueurs d’onde.Le 3ème Chapitre présente deux applications de l’holographie numérique au contrôle de structures compositesincorporées avec des pastilles piézoélectriques dédiées à l’émission acoustique. Nous avons démontré en premiertemps, la possibilité d’analyser par holographie numérique de Fresnel en temps moyenné le comportementvibratoire des poutres composites excitées harmoniquement. Dans un second temps, on a montré que les pastillesutilisées influencent le comportement mécanique des matériaux en régime statique.Le Chapitre 4 présente l’analyse expérimentale et numérique des structures composites soumises à un essai decisaillement en flexion trois points rapprochés. Nous présentons les résultats obtenus pour des applications à deséchantillons lin/époxy et lin/carbone/époxy.Le 5ème Chapitre aborde l’analyse des propriétés diélectriques des composites renforcés par fibres de lin. Deuxtechniques expérimentales sont mises en oeuvre : la calorimétrie différentielle à balayage (DSC) et l’impédancemètre de type Novocontrol. Nous concluons que les fibres de lin seules dans le composite sont moinshydrophiles que celles incorporées avec des fibres de carbone, ce qui explique la meilleure adhérencefibres/matrice dans le premier cas. / This PhD thesis describes the application of innovative analytical methods for the characterization of mechanicaland electrical properties of composite materials.The first chapter provides a state of the art of theoretical fundamentals and prerequisites needed to understandthe manuscript. A critical survey leads to a strategy for the analysis, based partly on digital holographic methodsand dielectric techniques.The second chapter is devoted to the choice of method of digital holography. In particular, this configurationshows some features that are analyzed in detail: the role of the aperture stop of the imaging system. We concludethat the Fresnel holography method has the advantage of achromatism for applications with multiplewavelengths.The third chapter presents two applications of digital holography control of composite structures with embeddedpiezoelectric patches dedicated to acoustic emission. We first demonstrate the possibility of analyzing thevibration behavior of composite beams using time averaged digital holography. Then, it was shown that thepellets used influence the mechanical behavior of materials under static conditions.Chapter 4 presents the experimental and numerical analysis of composite structures subjected to a shear test inclose three-point bending. We present the results obtained for samples with linen / flax and epoxy / carbon /epoxy.The last chapter deals with the analysis of the dielectric properties of composites reinforced with flax fibersstudied in the preceding chapter. We conclude that the flax fibers incorporated in the composite are lesshydrophilic than those incorporated with carbon fibers, which explains the improved adhesion fiber / matrix inthe first case.

(Spatio-temporale) Blind Source Separation (BSS) eignet sich für die Verarbeitung von Multikanal-Messungen im Bereich der kontaktlosen Biosignalerfassung. Ziel der BSS ist dabei die Trennung von (z.B. kardialen) Nutzsignalen und Störsignalen typisch für die kontaktlosen Messtechniken. Das Potential der BSS kann praktisch nur ausgeschöpft werden, wenn (1) ein geeignetes BSS-Modell verwendet wird, welches der Komplexität der Multikanal-Messung gerecht wird und (2) die unbestimmte Permutation unter den BSS-Ausgangssignalen gelöst wird, d.h. das Nutzsignal praktisch automatisiert identifiziert werden kann. Die vorliegende Arbeit entwirft ein Framework, mit dessen Hilfe die Effizienz von BSS-Algorithmen im Kontext des kamera-basierten Photoplethysmogramms bewertet werden kann. Empfehlungen zur Auswahl bestimmter Algorithmen im Zusammenhang mit spezifischen Signal-Charakteristiken werden abgeleitet. Außerdem werden im Rahmen der Arbeit Konzepte für die automatisierte Kanalauswahl nach BSS im Bereich der kontaktlosen Messung des Elektrokardiogramms entwickelt und bewertet. Neuartige Algorithmen basierend auf Sparse Coding erwiesen sich dabei als besonders effizient im Vergleich zu Standard-Methoden. / (Spatio-temporal) Blind Source Separation (BSS) provides a large potential to process distorted multichannel biosignal measurements in the context of novel contact-less recording techniques for separating distortions from the cardiac signal of interest. This potential can only be practically utilized (1) if a BSS model is applied that matches the complexity of the measurement, i.e. the signal mixture and (2) if permutation indeterminacy is solved among the BSS output components, i.e the component of interest can be practically selected. The present work, first, designs a framework to assess the efficacy of BSS algorithms in the context of the camera-based photoplethysmogram (cbPPG) and characterizes multiple BSS algorithms, accordingly. Algorithm selection recommendations for certain mixture characteristics are derived. Second, the present work develops and evaluates concepts to solve permutation indeterminacy for BSS outputs of contact-less electrocardiogram (ECG) recordings. The novel approach based on sparse coding is shown to outperform the existing concepts of higher order moments and frequency-domain features.