Interferometer Fiber Optic Gyroscope (IFOG) has established as critical sensor for advance navigation systems. Sensor coil is known to be heart of IFOG. The bias drift and scale factor performance of IFOG depend on the sensor coil. The environmental perturbations like vibration, shock, temperature and magnetic field can affect the measured phase difference between the counter propagating beams, thereby introducing a bias error resulting in degradation of IFOG performance. In general these factors are both time varying and unevenly distributed throughout the coil producing a net undesirable phase shift due to variations in the optical light path, which is undistinguishable from the rotation induced signal. The development of sensor coil for high performance includes selection of optical fiber, spool material, coil winding technique and potting adhesive. In the thesis, the effects of various perturbations like temperature, vibration and magnetic field on the sensor coil are analysed, which degrades the gyro performance. The effect of temperature and vibration can be reduced by proper selection of spool material, winding method and by applying adhesive during the winding of sensor coil. The effect of magnetic field can be reduced by using the high birefringence polarization maintaining fiber with shorter beat length, shielding the sensor coil and reducing the number of twist during the winding. Design and fabrication of the sensor coil is done for control grade & navigation grade FOG with fiber length of 100 m and 1000 m respectively with the polarization maintaining fiber of two different manufacturer Fiber Core, UK and Nufern, USA selected based upon the beat length and Numerical Aperture so that sensor coil has minimum effect of magnetic field and the bending of fiber. Presently the spool material used is Aluminium alloy (HE15) for the ease of fabrication and easily availability of material. The Quadrupolar winding is done to reduce the thermal gradient effects. The indigenously developed special adhesive is applied layer by layer to reduce the environmental effects. In order to study the lifetime of sensor coil accelerated aging test (85°C, RH 85 %) for 30 days is also carried out.

Face aux mutations sociales, environnementales et technologiques de notre société, la capacité de résoudre les problèmes complexes devient un incontournable. Les nouvelles philosophies du « faire » et l’élan collaboratif au sein du milieu de travail hypermoderne ne se reflètent pas systématiquement dans le design. En essayant de suivre le rythme d’un monde en transformation constante, le design d’aujourd’hui peine à se mettre à jour. Les théories portant sur l’innovation collaborative présentent des réponses pour répondre aux problèmes complexes en prônant la pratique d’une conduite à projet fluide, ou autrement dit, éco-auto-ré-organisationnelle. Or, faute d’outil opératoire, l’innovation collaborative reste encore au stade conceptuel, voire utopique. Cette thèse a comme objectif d’apporter une réflexion sur les conduites de et à projet en design dans le monde d’aujourd’hui. Partant d’un exemple précis, à savoir le Hackathon, elle explore les nouvelles façons de penser, de faire et de créer des solutions à partir d’une dynamique tout à fait innovatrice, basée sur une éthique et une pratique propre à la nouvelle société du « faire » inspirée, notamment, des hackers. Le Hackathon est ainsi analysé à travers une grille d’analyse nommée le Gyroscope du projet qui permet de souligner les principaux éléments constitutifs de la conduite à projet en relation les uns avec les autres et de saisir les spécificités requises pour que la conduite puisse répondre aux indicateurs théoriques de l’innovation collaborative. L’analyse démontre non seulement que le Hackathon est effectivement une application concrète d’une nouvelle éthique de travail, mais que sa force se trouve dans les premières étapes de la conceptualisation du projet. La question que cette analyse soulève est donc : Est-il possible d’envisager de l’étendre sur l’ensemble du processus de développement, soit de l’idéation à l’implantation ? Cette recherche présente une lecture archéologique de la discipline du design qui permet de souligner des figures emblématiques du projet à travers les périodes historiques qui ont marqué le design. La proposition d’une nouvelle figure, le Hacking design, souligne l’impact des transformations engendrées par l’hypermodernisme sur la pratique de cette discipline et le rôle du praticien, concluant ainsi que la pensée du design (Design thinking) est dorénavant dépassée par une éthique de travail qui va au-delà d’une pensée, mais implique une nouvelle posture épistémologique. De nombreuses disciplines contigües au Design, dont la Gestion, l’Entrepreneuriat et l’Ingénierie, présentent ainsi un intérêt marqué pour le Design qu’ils perçoivent comme une réponse tributaire au succès de l’innovation collaborative au sein des organisations. Les attentes envers le Design, de sa théorie à sa pratique, sont donc grandes. / Today’s hypermodern working environment is experiencing important social, environmental and technological changes pressing actors to acquire the know-how to solve complex problems. The new philosophy of "doing" and the rise of working collaboration strategies arising in our hypermodern society are not systematically reflected in design’s practice. Indeed, by trying to keep pace with a world in constant change, today's design discipline is struggling to keep up. The theories on collaborative innovation present some answers to develop this know-how by advocating a practice that deploys fluidity in projects or, in other words, an eco-auto-re-organisational strategy. However, in the absence of a practical and operational tool, collaborative innovation is still at the conceptual and utopian stage. This thesis aims to rethink project management in our hypermodern world. Starting from a specific example, the Hackathon, it explores new ways of thinking, doing and creating solutions based on an entirely innovative dynamics, grounded on an ethic and a practice specific to the new society of "doing" and inspired, in particular, by the hackers. The Hackathon is thus analyzed through an analytic grid called the Gyroscope of the project through which the actors, the actions and the organisation of the project are evaluated. The Gyroscope makes it possible to identify the project’s components in relation to each other and to understand the requirements needed to carry out each project according to the theoretical indicators of collaborative innovation. The analysis not only demonstrates that the Hackathon is indeed a concrete application of a new work ethic, but that its strength is in the early stages of the project’s conceptualization. The question that this analysis raises is: Is it possible to consider extending it to the whole development process, from ideation to implementation? This research presents an archaeological reading of the discipline of design which allows to identify the emblematic figures of the project through the historical periods that marked the design. The proposal of a new figure, the Hacking design, highlights the impact of hypermodernism's transformations on the practice of this discipline and the role of the practitioner, thus concluding that Design Thinking is now overtaken by an ethic of work that goes beyond a way of thinking, but involves a new epistemological posture. Many disciplines contiguous to Design, including Management, Entrepreneurship and Engineering, have therefore a strong interest in Design, which they perceive as a response to the success of collaborative innovation within organizations. The expectations towards the discipline of Design, from its theory to its practice are, therefore, very high.

Dans cette thèse, en collaboration avec l'entreprise AéroDRONES, le Laboratoire Bordelais de Recherche en Informatique et l'INRIA, nous abordons le problème de la perception de l'environnement à partir d'une caméra embarquée sur un drone léger. Nous avons conçu, développé et validé de nouvelles méthodes de traitement qui optimisent l'exploitation des données produites par des systèmes de prise de vue aéroportés bas coût. D'une part, nous présentons une méthode d'autocalibrage de la caméra et de la tourelle d'orientation, sans condition spécifique sur l'environnement observé. Ensuite nous proposons un nouvel algorithme pour extraire la rotation de la caméra calibrée entre deux images (gyroscope visuel) et l'appliquons à la stabilisation vidéo en temps réel. D'autre part, nous proposons une méthode de géoréférencement des images par fusion avec un fond cartographique existant. Cette méthode permet d'enrichir des bases de données de photos aériennes, en gérant les cas de non-planéité du terrain. / The last decade has seen the emergence of many Unmanned Aerial Vehicles (UAV) which are becoming increasingly cheap and miniaturized. A mounted video-camera is standard equipment and can be found on any such UAVs. In this context, we present robust techniques to enhance autonomy levels of airborne vision systems based on mini-UAV technologies. First, we present a camera autocalibration method based on central projection based image \dimension{2}-invariants analysis and we compare it to classical Dual Image of the Absolute Conic (DIAC) technique. We present also a method to detect and calibrate turret's effectors hierarchy. Then, we propose a new algorithm to extract a calibrated camera self-rotation (visual gyroscope) and we apply it to propose a real-time video stabilizer with full perspective correction.

Detta projekt syftar till att undersöka om det går att kurskorrigera en av Weda AB:s poolrengöringsrobotar med hjälp av ett MEMS-gyroskop. Den valda rengöringsroboten styrs idag av en PLC, och konceptet är att komplettera styrenheten med ett MEMS gyroskop som kan detektera kursavvikelser. Undersökandet av möjligheterna för implementeringen börjar med att samla information om MEMS gyroskopens funktion och i vilka tekniker de används idag. Vidare utförs beräkningar mot Wedas definition av rak kurs, det resulterade i för höga krav på känsligheten i gyroskopet. Trots det otillfredsställande resultatet beslutar Weda att projektet ska fortsätta undersöka gyroskopets möjligheter. En marknadsundersöknings med 9 tillverkningsföretag genomförs i syfte att se vad marknaden erbjuder för MEMS gyroskop idag. Sedan konsulteras distribueringsföretaget Avnet som bidrar med sina kunskaper, erfarenheter och rekommendationer för konceptet. Ett av de framstående gyroskopen i undersökningen användes för att genomföra två tester. Syftet av dem var att simulera olika situationer som rengöringsroboten kan utsättas för. Resultatet visar att repetitionsnoggrannheten är god men att gyroskopet inte är tillförlitligt i låga hastigheter, vilket är en dålig egenskap för rengöringsroboten W2000 som körs med en hastighet 0,2 m/s. Testresultatet diskuterades med Bosch och dem tror att gyroskopets automatiska kalibrering är orsaken till att det inte ger tillförlitliga mätdata vid låga hastigheter. / During this project the possibilities to monitor and adjust the direction of a pool cleaning robot with a MEMS gyroscope are evaluated. The robot chosen for the evaluation is manufactured by Weda AB. The concept is to add a MEMS gyroscope to the robot, which will give the control unit (PLC) feedback regarding the direction of the robot. The evaluation includes general information about MEMS gyroscopes, where they are used, common built in errors etc. To be able to select a suitable MEMS gyroscope the needed sensitivity is calculated. The needed sensitivity is based on requirements from Weda AB. The evaluation also includes a market survey which shows that the needed sensitivity cannot be fulfilled by products available on the market. The market survey is based on nine manufacturing companies and a recommendation from a distribution company called Avnet. One of the prominent MEMS gyroscopes was used to carry out two tests. The tests were designed to mimic motions of the pool cleaning robot. The test result shows that the gyroscope has good repetition accuracy, but it is not trustworthy when the rotation speed is low. The test result was discussed with the manufacturer and they think that the non positive result is caused by the automatic calibration.

Approved for public release; distribution in unlimited. / This thesis develops and implements a Control Moment Gyroscope (CMG) steering law, controller and active balancing system for a three-axis satellite simulator (TASS). The CMGs are configured in a typical pyramid configuration (the fourth CMG position being null). The development was done primarily with simulation and experiments utilizing Real Time Workshop and XPC Target of MATLAB and SIMULINK. The TASS is a double circular platform mounted on a spherical air bearing with the center of rotation (CR) about the approximate physical geometric center of the simulator. The TASS utilizes three moveable masses in the three body axes for balancing which actively eliminate any center of gravity (CG) offset and return the CG to the CR. The TASS supports an optics payload designed to acquire, track and point a received laser beam onto an off-satellite target. The target may be stationary or moving. Actively balancing the TASS reduces the torque output requirement for the CMGs while maintaining either a stabilized level platform or a particular commanded attitude. Reduction or elimination of torque output from the CMGs results in a more stabilized platform, less structural induced vibration, less jitter in payload optics and less power required in spacecraft applications. / Lieutenant Commander, United States Navy

Made available in DSpace on 2017-07-10T17:11:52Z (GMT). No. of bitstreams: 1 Texto completo - Rosiney.pdf: 7631119 bytes, checksum: 43c0461bb49060121b74d945a88d53d4 (MD5) Previous issue date: 2012-11-26 / The present work proposes a study of the dynamics of a gyroscope using simulated data of an analytical model by comparing with experimental data. Classical mechanical modeling approaches are used to identify the equilibrium points, stability and verification of the regions where the motion equations of the gyroscope can present regular or chaotic behavior. The Lyapunov exponents are identified through the standard method, Eckmann-Ruelle Method, Wolf method with time series and the 0-1 test. The results achieved illustrate the main advantages and drawbacks of each method and allow to observe qualitatively and quantitatively information about the motion of the gyroscope used. / Este trabalho propõe um estudo da dinâmica de um giroscópio usando dados de simulação de um modelo analítico comparando com dados experimentais. Verifica-se a modelagem usando mecânica clássica, estudo de pontos de equilíbrio, estabilidade e verificação de regiões onde o movimento do giroscópio pode ficar regular ou caótico. Os expoentes de Lyapunov são identificados usando o método padrão, método de Eckmann-Ruelle, método deWolf com séries temporais e o teste 0-1. Os resultados alcançados nesta dissertação permitiram comparar as principais vantagens e desvantagens de cada um dos métodos e extrair informações qualitativas e quantitativas sobre o movimento do giroscópio em estudo.

Sensing rotation has been an essential topic in navigation and many other applications. Gyroscopes based on propagation of light beams over fixed distances have gained interest with the development of the laser. Since the 1970s, with the development of fiber optics these laser based gyroscopes have developed into compact devices, which can fit in the palm of your hand. In this thesis, we describe and analyze the development of a fiber-optic gyroscope. Fiber optic gyroscopes (also called fiber gyro or FOG) have been under development for different types of applications for more than 30 years all around the world. The physical basis of the fiber gyro is the Sagnac effect that was discovered in the early 1900s and is named after its discoverer. In this work, we first explain the principle of operation of the Sagnac effect and we derive the fundamental formulations in order to have an analytical understanding of the theory. Then, we examine the fiber optic gyro configuration component by component, starting with the laser diode pumped broadband light emitting Erbium-doped superfluorescent source. In addition, the principle of phase modulation, electro-optic phase modulators, fiber optic cables and fiber winding techniques, such as quadrupolar winding is explained within the context of development of the FOG. v The FOG that was assembled was based on circulation and sensing of broadband light centered around 1550nm. The fiber coil was 5km long in order to increase sensitivity in the FOG device. Since single-mode fibers were used steps were taken to ensure successful operation even with polarization dependent errors. The constructed system demonstrated a low sensitivity with a large uncertainty while sensing typical rotation rates. Reasons behind the errors and low sensitivity, as well as improvements that can be made are discussed.

This thesis reports the development of micromachined accelerometers and gyroscopes that can be used for micromachined inertial measurement units (IMUs). Micromachined IMUs started to appear in the market in the past decade as low cost, moderate performance alternative in many inertial applications including military, industrial, medical, and consumer applications. In the framework of this thesis, a number of accelerometers and gyroscopes have been developed in three different fabrication processes, and the operation of these fabricated devices is verified with extensive tests. In addition, the fabricated accelerometers were combined with external readout electronics to obtain hybrid accelerometer systems, which were tested in industrial test facilities. The accelerometers and gyroscopes are designed and optimized using the MATLAB analytical simulator and COVENTORWARE finite element simulation tool. First set of devices is fabricated using a commercial foundry process called SOIMUMPs, while the second set of devices is fabricated using the electroplating processes developed at METU-MET facilities. The third set of devices is designed for a new advanced process based on DRIE, which is under development. Mechanical and electrical test results of the fabricated accelerometers and gyroscopes are in close agreement with the designed values. The testing of the SOI and nickel accelerometers is also performed in industrial test environments. In order to perform these tests, accelerometers are hybrid connected to commercially available capacitive readout circuits. These accelerometer systems require only two DC supply voltages for operation and provide an analog output voltage related to the input acceleration. The industrial tests show that the SOI accelerometer system yields a 799 &micro / g/&amp / #8730 / Hz average noise floor, a 1.8 mg/&amp / #8730 / Hz peak noise floor, a 22.2 mV/g sensitivity, and a 0.1 % nonlinearity, while the nickel accelerometer system yields a 228 &micro / g/&amp / #8730 / Hz average noise floor, a 375 &micro / g/&amp / #8730 / Hz peak noise floor, a 1.02 V/g sensitivity, and a 0.23 % nonlinearity. Long-term drift components of the accelerometers are determined to be smaller than 20 mg. These systems are the highest performance micromachined accelerometer systems developed in Turkey, and they can be used in implementation of a national inertial measurement unit.

In this thesis, recently developed Blended Inverse (B-inverse) steering law is applied to two different redundant actuator systems. First, repeatability of Binverse is demonstrated on a redundant robotic manipulator. Its singularity avoidance and singularity transition performance is also demonstrated on the same actuator system. It is shown that B-inverse steering law provides singularity avoidance, singularity transition and repeatability. Second, its effectiveness is demonstrated for an Integrated Power and Attitude Control - Control Moment Gyroscope (IPAC-CMG) cluster, which can perform energy management and attitude control functions simultaneously. For this purpose, an IPAC-CMG flywheel is conceptually designed. A control policy is developed for the energy management.

Made available in DSpace on 2014-12-17T14:56:18Z (GMT). No. of bitstreams: 1 AndersonBNS_DISSERT.pdf: 1465627 bytes, checksum: c03d80fd5309916ed15fcc6c0a45c8a8 (MD5) Previous issue date: 2013-10-07 / No espa?o tridimensional, um corpo r?gido qualquer pode efetuar transla??es e ou rota??es em rela??o a cada um de seus eixos. Identificar com precis?o o deslocamento realizado por um corpo ? fundamental para alguns tipos de sistemas em engenharia. Em sistemas de navega??o inercial tradicionais, utilizam-se aceler?metros para reconhecer a acelera??o linear e girosc?pios para reconhecer a velocidade angular registrada durante o deslocamento. O girosc?pio, entretanto, ? um dispositivo de custo mais elevado e com alto consumo de energia quando comparado a um aceler?metro. Essa desvantagem deu origem a pesquisas a respeito de sistemas e unidades de medidas inerciais que n?o utilizam girosc?pios. A ideia de utilizar apenas aceler?metros para calcular o movimento linear e angular surgiu no in?cio da d?cada de 60 e vem se desenvolvendo atrav?s de modelos que variam no n?mero de sensores, na maneira como estes s?o organizados e no modelo matem?tico que ? utilizado para derivar o movimento do corpo. Esse trabalho prop?e um esquema de configura??o para constru??o de uma unidade de medida inercial que utiliza tr?s aceler?metros triaxiais. Para identificar o deslocamento de um corpo r?gido a partir deste esquema, foi utilizado um modelo matem?tico que utiliza apenas os nove sinais de acelera??o extra?dos dos tr?s sensores. A proposta sugere que os sensores sejam montados e distribu?dos em formato de L . Essa disposi??o permite a utiliza??o de um ?nico plano do sistema de coordenadas, facilitando assim a instala??o e configura??o destes dispositivos e possibilitando a implanta??o dos sensores em uma ?nica placa de circuito integrado. Os resultados encontrados a partir das simula??es iniciais demonstram a viabilidade da utiliza??o do esquema de configura??o proposto