Sistemas de levitação magnética são inerentemente não-lineares e, quando con- trolados digitalmente, normalmente, esbarram em limitações do hardware empregado. O objetivo desta tese é apresentar aspectos teóricos e práticos durante a aplicação da teoria de controle H1 não-linear em sistemas de levitação magnética. A primeira con- tribuição desta tese é apresentar um procedimento de projeto de um controlador H1 não-linear que utiliza funções de ponderação com dinâmica, obtidas a partir do projeto de um controlador H1 linear. Assim como no caso linear, essas funções de ponderação possibilitam a rejeição de perturbações, ruídos de sensor, aumento da robustez, den- tre outras especificações. A segunda contribuição é apresentar um procedimento de conversão de uma rotina implementada em ponto-flutuante para ponto-fixo, utilizando minimização de norma l1, que foi implementada em um DSP de 32 bits em ponto- fixo. Resultados experimentais também são apresentados, nos quais a performance do controlador não-linear é especificamente avaliada na fase inicial de levitação. / Electromagnetic suspension systems are inherently nonlinear and often face hard- ware limitation when digitally controlled. The goal of this thesis is to present theoretical and practical aspects during the nonlinear H1 control applied on an electromagnetic suspension system. The first contribution is the design of a nonlinear H1 controller, including dynamic weighting functions, obtained from a linear H1 controller. Just as in the linear case, this dynamic weighting functions provide the disturbance and noise sensor rejection, robustness improvement, among other specifications. The second con- tribution is to present a procedure able to translate a floating-point algorithm into a fixed-point algorithm by using l1 norm minimization due to conversion error, which was then implemented into a 32-bit fixed-point DSP. Experimental results are also pre-sented, in which the performance of the nonlinear controller is evaluated specifically in the initial suspension phase.

Sistemas de levitação magnética são inerentemente não-lineares e, quando con- trolados digitalmente, normalmente, esbarram em limitações do hardware empregado. O objetivo desta tese é apresentar aspectos teóricos e práticos durante a aplicação da teoria de controle H1 não-linear em sistemas de levitação magnética. A primeira con- tribuição desta tese é apresentar um procedimento de projeto de um controlador H1 não-linear que utiliza funções de ponderação com dinâmica, obtidas a partir do projeto de um controlador H1 linear. Assim como no caso linear, essas funções de ponderação possibilitam a rejeição de perturbações, ruídos de sensor, aumento da robustez, den- tre outras especificações. A segunda contribuição é apresentar um procedimento de conversão de uma rotina implementada em ponto-flutuante para ponto-fixo, utilizando minimização de norma l1, que foi implementada em um DSP de 32 bits em ponto- fixo. Resultados experimentais também são apresentados, nos quais a performance do controlador não-linear é especificamente avaliada na fase inicial de levitação. / Electromagnetic suspension systems are inherently nonlinear and often face hard- ware limitation when digitally controlled. The goal of this thesis is to present theoretical and practical aspects during the nonlinear H1 control applied on an electromagnetic suspension system. The first contribution is the design of a nonlinear H1 controller, including dynamic weighting functions, obtained from a linear H1 controller. Just as in the linear case, this dynamic weighting functions provide the disturbance and noise sensor rejection, robustness improvement, among other specifications. The second con- tribution is to present a procedure able to translate a floating-point algorithm into a fixed-point algorithm by using l1 norm minimization due to conversion error, which was then implemented into a 32-bit fixed-point DSP. Experimental results are also pre-sented, in which the performance of the nonlinear controller is evaluated specifically in the initial suspension phase.

Ce mémoire décrit la conception, la modélisation et la commande d’un manipulateur pneumatique,fondé sur un principe de traction aérodynamique original. De puissants jets d’air verticauxpermettent de créer un flux d’air horizontal pour manipuler des objets sans contact. Les objetssont maintenus en constante lévitation sur la surface grâce à un coussin d’air, et peuvent positionnés selon trois degrés de libert´ du plan, grâce à la combinaison adéquate et distribuéede jets d’air verticaux. Nous détaillons la conception d’un prototype original de manipulateurexploitant ce principe fluidique. Ce prototype a été intégré dans une plate-forme expérimentaleafin de valider le principe de manipulation : le système permet de déplacer des objets à unevitesse atteignant 180 mm/s. Nous avons modélisé le fonctionnement de la surface selon plusieursméthodes. Un premier modèle comportemental, fond´e sur des données expérimentales, aété établi. Il permet de simuler l’´evolution de la position d’un objet sur la surface, selon un degréde liberté . Deux modèles de connaissance, fond´es sur une étude aérodynamique fondamentale,donnent l’´evolution de la position de l’objet selon respectivement deux et trois degrés de libertédu plan. Chacun des modèles a été validé expérimentalement. Nous avons synthétisé différentscontrˆoleurs afin d’asservir la position de l’objet : un premier, de type PID, et un second, de typerobuste (méthode H1). La commande de un, puis deux degrés de liberté du système, a permisd’atteindre de bonnes performances : temps de réponse d’environ 2 s et dépassement souventinférieur à 5%. Nous avons également étudié un micro-manipulateur pneumatique permettant ded´eplacer des objets de taille millimétrique selon deux directions, grâce à des jets d’air inclinés.Ces objets peuvent atteindre des vitesses de 123 mm/s. La résolution du positionnement estinférieure à 0.4 μm. / This thesis presents the design, the modeling and the control of a pneumatic manipulatorbased on an original aerodynamic traction principle. An horizontal air flow is induced by strongvertical air jets in order to manipulate objects without contact. The objects are maintained inconstant levitation on an air cushion. Three degrees of freedom positioning of the objects canbe realized thanks to the right combination of distributed air jets. The design of an originalmanipulator using this aerodynamic principle is detailed. The device has been integrated in anexperimental setup in order to validate the manipulation principle : objects can reach velocityof 180 mm/s. Several models of the system have been established. A first model, based on experimentaldata, gives the evolution of the 1 DOF-position of an object on the device. Twoother models, based on a fundamental aerodynamic study, respectively give the evolution of the2- and 3-DOF position of the objet. The three models have been validated experimentally. Inorder to control the position of the object, different controllers have been designed : a PID oneand a robust H1 one. The control of one and two degrees of freedom of the device gives goodperformances : settling time of around 2 s and overshoot less than 5% in most of the cases. Wehave also studied a micro-manipulator that is able to position millimetric sized objects, in twodirections, thanks to inclined air jets. Objects can reach velocity of 123 mm/s, and the resolutionof the positioning is less than 0.4 μm.

Studium chování opticky zachycených částic nám umožňuje porozumět základním fyzikálním jevům plynoucím z interakce světla a hmoty. Předkládaná práce podává vysvětlení zesílení tažné síly působící na opticky svázané částice ve strukturovaném světelném poli, tzv. tažném svazku. Ukazujeme, že pohyb dvou opticky svázaných objektů v tažném svazku je silně závislý na jejich vzájemné vzdálenosti a prostorové orientaci, což rozšiřuje možnosti manipulace hmoty pomocí světla. Následně se práce zaměřuje na levitaci opticky zachycených částic ve vakuu. Představujeme novou metodologii na charakterizaci vlastností slabě nelinearního Duffingova oscilátoru reprezentovaného opticky levitující částicí. Metoda je založena na průměrování trajektorií s určitou počáteční pozicí ve fázovém prostoru sestávajícím z polohy a rychlosti částice a poskytuje informaci o parametrech oscilátoru přímo ze zaznamenaného pohybu. Náš inovativní postup je srovnán s běžně užívanou metodou založenou na analýze spektrální hustoty polohy částice a za využití numerických simulací ukazujeme její použitelnost i v nízkých tlacích, kde nelinearita hraje významnou roli.

Cieľom práce je aplikácia lokálnych aproximátorov pre riadenie reálnych mechatronických sústav pomocou metódy dopredného riadenia predstavujúcej zaujímavú alternatívu k metódam využívajúcim globálne aproximátory. Po ukážkových príkladoch funkcie lokálnych aproximátorov bol navrhnutý algoritmus implementovaný pre riadenie dvoch sústav, elektronickej škrtiacej klapky a výukového modelu magnetickej levitácie, predstavujúcich vysoko nelineárne a nestabilné sústavy. Skúmali sme, či riadiaci algoritmus bude mať pozitívny vplyv na presnosť regulácie, ďalej bola skúmaná jeho schopnosť prispôsobiť sa zmene parametrov sústavy a tiež prípadná možnosť jeho implementácie pre mikrokontrolér znížením vzorkovacej frekvencie. Výsledky ukázali, že riadenie založené na lokálnych modeloch zlepšilo riadenie v porovnaní s jednoduchým PID regulátorom a že má schopnosť adaptability. Veľmi výhodné sa zdá byť jeho použitie pre zariadenia umožnujúce vzorkovaciu frekvenciu do 1 kHz.

<p>  </p> <p>A harmonic oscillator is a ubiquitous tool in various disciplines of engineering and physics for sensing and energy transduction. The degrees of freedom, low noise oscillation, and efficient input-output coupling are important metrics when designing sensors and transducers using such oscillators. The ultimate examples of such oscillators are quantum mechanical oscillators coherently transducing information or energy. Atoms are oscillators whose degrees of freedom can be controlled and probed coherently by means of light. Elegant techniques developed during the last few decades have enabled us to use atoms, for example, to build exquisite quantum sensors such as clocks with the precision of <1 second error over the lifetime of the universe, to store and transduce information of various forms and also to develop quantum processors. Similar to atoms, mechanical oscillators can also be controlled ultimately to their single vibrational quanta and be used for similar sensing and transduction applications.</p> <p><br></p> <p>In this thesis, we explore both atomic and mechanical systems and develop a toolbox to build an effective atom-light interface and light-oscillator interface for controlling such atomic and mechanical oscillators and use them in sensing and storage applications. Primarily, we study two disparate platforms: 1) rare-earth ions in solids integrated into photonic chips as a compact and heterogeneous platform and 2) nanoscopic and macroscopic oscillators interfaced with light and magnetic field to isolate them from environmental noise. </p> <p><br></p> <p>Rare earth (RE) ions in crystals have been identified as robust optical centers and promising candidates for quantum communication and transduction applications. Lithium niobate (LN), a novel crystalline host of RE ions, is considered as a viable material for photonic system integration because of its electro-optic and integration capability. This thesis first experimentally reports the activation and characterization of LN crystals implanted with Yb and Er ions and describes their scalable integration with a silicon photonic chip with waveguide and resonator structures. The evanescent coupling of light emitted from Er ions with optical modes of waveguide and microcavity and modified photoluminescence (PL) of Er ions from the integrated on-chip Er:LN-Si-SiN photonic device with quality factor of 104 have been observed at room temperature. This integrated platform can ultimately enable developing quantum memory and provide a path to integrate more photonic components on a single chip for applications in quantum communication and transduction.</p> <p><br></p> <p>Optomechanical systems are also considered as candidates for light storage and sensing. In this thesis, we also present results of the theoretical study of coherent light storage in an array of nanomechanical resonators. The majority of the thesis is focusing on an optomechanical sensing experiment based on levitation. An oscillator well isolated from environmental noise can be used to sense force, inertia, torque, and magnetic field with high sensitivity as the interaction with these quantities can change the amplitude or frequency of the oscillator’s vibration, which can be accurately measured by light. It has been proposed that such levitated macroscopic objects could be used as quantum sensors and transducers at their quantum ground states. They are also proposed as a platform to test fundamental physics such as detecting gravitational waves, observing macroscopic quantum entanglement, verifying the spontaneous collapse models, and searching for dark matter.</p> <p><br></p> <p>In particular, we consider superconducting levitation of macroscopic objects in vacuum whose positions are measured by light. We build an optomechanical platform based on a levitated small high reflective (HR)-coated mirror above a superconductor disk. We use this levitated mirror at ambient conditions to detect the magnetic field with a sensitivity on the order of <em>pT/sqrt(Hz).</em> Moreover, the levitated mirror is used as the end mirror of a Fabry–Pérot cavity to create an optical resonance that could be used to study coherent radiation pressure forces. The platform provides a sensitive tool to measure the various forces exerted on the mirror and it offers the possibility of the coherent optical trapping of macroscopic objects and precision gravity sensing. Moreover, we study the nonlinear dissipation and mode coupling of a levitated HR-coated magnetic mirror above a superconducting disk in vacuum conditions. We observe that by exciting one vibrational mode of the mirror, the vibrational noise of another mode can be significantly suppressed by a factor of 60. We attribute this unique noise suppression mechanism to the mode coupling and nonlinear dissipation caused by the driven magnetic inhomogeneity of the levitated object. Such a suppression mechanism can enable cooling certain modes independent of their detection and position in the spectrum, which may be promising for precision sensing applications.</p>

O objetivo deste trabalho é apresentar um novo tipo de sistema de levitação baseado na força de interação magnética entre uma bobina de núcleo não-magnético e um imã permanente, em casos de simetria axial entre os dispositivos, nos moldes do problema 23 proposto no TEAM Workshop. Este tema é bastante atual e vários métodos têm sido estudados e propostos em razão da complexidade na determinação precisa das forças sobre os imãs permanentes imersos em um campo magnético em um circuito magnético aberto. O primeiro grande desafio deste trabalho é obter uma expressão analítica para esta força de interação magnética em casos de simetria axial usando o método de cargas magnéticas ligadas. Para tal, algumas hipóteses simplificadoras foram adotadas como considerar o campo magnético gerado pela bobina aproximadamente uniforme em toda a face do imã permanente e assumir que a magnetização do imã é constante e independente da variação de sua distância para a bobina. Pretende-se aproveitar o sistema implementado neste trabalho como bancada experimental no Laboratório de Controle da Universidade de São Paulo. Foi projetado um controlador PID através de ferramentas gráficas obedecendo a alguns critérios de desempenho, tanto no domínio do tempo como no domínio da freqüência. Uma vez sintonizado, foi utilizado o toolbox Real-Time Windows Target do Simulink e a placa de aquisição PCI 6221 (da National Instruments) para controlar em tempo real a planta de levitação em malha fechada. Os resultados experimentais foram muito satisfatórios de modo que o modelo analítico foi considerado válido. O sistema apresentou boas características como, por exemplo, um bom acompanhamento do sinal de referência, mesmo em grandes excursões, erro de regime nulo, levitação estável em distâncias relativamente grandes e uma boa estabilidade radial. O uso de dois sensores Hall mostrou-se eficiente na determinação da posição do imã permanente. / The objective of this work is to present a new kind of levitation system based on the interaction force between a non-magnetic core coil and a permanent magnet, in the case of axial symmetry between devices, as proposed by TEAM Workshop problem 23. This theme is very current and various methods have been studied and proposed in face of the complexity in determining precisely the force over permanent magnets immersed in a magnetic field in an open magnetic circuit. The first big challenge of this work is to obtain an analytical expression for this interaction magnetic force in the case of axial symmetry using the equivalent magnetic charge method. For this, some simplifying hypothesis have been adopted like considering the magnetic field created by the coil approximately uniform over all the permanent magnets face and assuming that magnets magnetization is constant and independent of the variation of its distance to the coil. The system implemented in this work is intended to be used as an experimental bench for the Laboratory of Control of Sao Paulo University. A PID controller was projected by means of graphical tools according to some criteria for performance, both in the field of time as in the frequency domain. Once tuned, the toolbox Real-Time Windows Target of Simulink and the PCI-6221 acquisition board (of National Instruments) were used to control in real time the levitation plant in closed loop. The experimental results were very satisfactory so that the analytical model was considered valid. The system showed good characteristics as, for instance, a good tracking of reference signal, even in large excursions of it, null stationary error, stable levitation at relatively big gaps and a good radial stability. The use of two Hall-effect sensors proved to be efficient in the determination of permanent magnets position.

O objetivo deste trabalho é apresentar um novo tipo de sistema de levitação baseado na força de interação magnética entre uma bobina de núcleo não-magnético e um imã permanente, em casos de simetria axial entre os dispositivos, nos moldes do problema 23 proposto no TEAM Workshop. Este tema é bastante atual e vários métodos têm sido estudados e propostos em razão da complexidade na determinação precisa das forças sobre os imãs permanentes imersos em um campo magnético em um circuito magnético aberto. O primeiro grande desafio deste trabalho é obter uma expressão analítica para esta força de interação magnética em casos de simetria axial usando o método de cargas magnéticas ligadas. Para tal, algumas hipóteses simplificadoras foram adotadas como considerar o campo magnético gerado pela bobina aproximadamente uniforme em toda a face do imã permanente e assumir que a magnetização do imã é constante e independente da variação de sua distância para a bobina. Pretende-se aproveitar o sistema implementado neste trabalho como bancada experimental no Laboratório de Controle da Universidade de São Paulo. Foi projetado um controlador PID através de ferramentas gráficas obedecendo a alguns critérios de desempenho, tanto no domínio do tempo como no domínio da freqüência. Uma vez sintonizado, foi utilizado o toolbox Real-Time Windows Target do Simulink e a placa de aquisição PCI 6221 (da National Instruments) para controlar em tempo real a planta de levitação em malha fechada. Os resultados experimentais foram muito satisfatórios de modo que o modelo analítico foi considerado válido. O sistema apresentou boas características como, por exemplo, um bom acompanhamento do sinal de referência, mesmo em grandes excursões, erro de regime nulo, levitação estável em distâncias relativamente grandes e uma boa estabilidade radial. O uso de dois sensores Hall mostrou-se eficiente na determinação da posição do imã permanente. / The objective of this work is to present a new kind of levitation system based on the interaction force between a non-magnetic core coil and a permanent magnet, in the case of axial symmetry between devices, as proposed by TEAM Workshop problem 23. This theme is very current and various methods have been studied and proposed in face of the complexity in determining precisely the force over permanent magnets immersed in a magnetic field in an open magnetic circuit. The first big challenge of this work is to obtain an analytical expression for this interaction magnetic force in the case of axial symmetry using the equivalent magnetic charge method. For this, some simplifying hypothesis have been adopted like considering the magnetic field created by the coil approximately uniform over all the permanent magnets face and assuming that magnets magnetization is constant and independent of the variation of its distance to the coil. The system implemented in this work is intended to be used as an experimental bench for the Laboratory of Control of Sao Paulo University. A PID controller was projected by means of graphical tools according to some criteria for performance, both in the field of time as in the frequency domain. Once tuned, the toolbox Real-Time Windows Target of Simulink and the PCI-6221 acquisition board (of National Instruments) were used to control in real time the levitation plant in closed loop. The experimental results were very satisfactory so that the analytical model was considered valid. The system showed good characteristics as, for instance, a good tracking of reference signal, even in large excursions of it, null stationary error, stable levitation at relatively big gaps and a good radial stability. The use of two Hall-effect sensors proved to be efficient in the determination of permanent magnets position.

L’objectif de cette thèse est le développement d’un nouveau capteur de forcemulti-axes destiné à mesurer les composantes de friction impliquées dans lecontact doigt/objet lors la micromanipulation dextre. Des études théoriques etdes simulations par éléments finis ont conduit à la conception de ce capteurMEMS piézorésistif composé d’une plate-forme centrale munie d’une microbille,entourée d’une table compliante. D’après les résultats de simulations, ce capteur estcapable de mesurer indépendamment les forces normales et de frottement (couplageréciproque inférieure à 1%) avec une bonne sensibilité. Différents runs de fabricationnous ont permis d’obtenir des dispositifs exploitables. La structure mécanique de cescapteurs a été validée par la mesure des fréquences de résonance qui sont en accordavec les résultats de simulation. Des premiers résultats expérimentaux en termesde mesure de force ont ensuite été obtenus grâce au développement d’un banc detest (structure robotique, actionneurs, caméras, etc.). Nous nous sommes égalementintéressés à la problématique de l’étalonnage des capteurs de micro et nanoforceà l’aide de ressorts magnétiques reliés à des masses mesurables. Nous avons, danscette optique, mis au point une stratégie d’estimation et de compensation passivedes perturbations mécaniques en utilisant un principe différentiel. Cette approchea été appliquée à un capteur de nanoforce basé sur la lévitation diamagnétique et aabouti à des résultats prometteurs : une résolution inférieure au nanonewton a puêtre obtenue. / Sensor enabling to characterize the finger/object contact involved in dexterousmicromanipulation. Theoretical studies and finite elements simulations have lead tothe conception of this piezoresistive MEMS sensor composed of a central platformwith a micro-ball and surrounded by a compliant table. According to the simulationresults, this sensor is able to independently measure the normal and friction forces(crosstalk less than 1 %) with a good sensitivity. Several runs of fabrication allowedus to obtain usable devices. The mechanical structure of such sensors has beenvalidated by the measurement of resonance frequencies that are consistent with thesimulation results. The first experimental results in terms of force measurement werethen obtained through the development of a test bench (robotic structure, actuators,cameras, etc.). We were also interested in the problem of calibration of micro andnanoforce sensors using magnetic springs connected to measurable masses. In thiscontext, we developed an estimation strategy and a passive rejection of mechanicaldisturbances using a differential principle. This approach was applied to a nanoforcesensor based on the diamagnetic levitation and yielded promising results: a resolutionlower the nanonewton level could be obtained.