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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Controle de sistema de mancais magnéticos ativos para um motor de indução linear tubular. / Control system applied to active magnetic bearings for a tubular linear induction motor.

Monaco, Leandro Henrique 08 October 2012 (has links)
Para aplicações de extração de petróleo de poços em terra foi desenvolvido pelo Laboratório de Eletromagnetismo Aplicado (LMAG) da Escola Politécnica da Universidade de São Paulo um protótipo de motor de indução linear tubular (MILT), onde o movimento axial do secundário do motor aciona diretamente a bomba de extração situada no fundo do poço. Numa segunda etapa, foi prevista a substituição dos mancais mecânicos por dois mancais magnéticos ativos (AMBs), que permitem melhor movimentação e praticamente nenhum atrito, reduzindo o desgaste causado por impurezas contidas no petróleo extraído, e consequentemente os esforços de manutenção. Todavia, o protótipo atual possui apenas um mancal magnético, e o outro é mecânico. O presente trabalho apresenta a instalação do segundo mancal magnético ao protótipo do MILT, e propõe realizar o controle do sistema de mancais magnéticos para o MILT, tendo em vista um problema multivariável, onde as posições do secundário do motor em relação aos dois mancais são correlacionadas, bem como as ações de controle sobre os mesmos. O trabalho faz uma revisão do sistema atual com um AMB, abordando sua concepção física, modelagem e o controlador, e tal controlador é replicado para o segundo AMB. Um novo modelo é apresentado, considerando o comportamento multivariável dos dois AMBs, e um sistema de controle robusto multivariável é projetado, através da técnica LQG/LTR. Resultados de simulação do novo controlador são analisados e comparados com os resultados experimentais do controlador atual aplicado aos dois AMBs, e apresentam-se as conclusões. / For onshore oil extraction applications, a tubular linear induction motor (TLIM) prototype was developed by Applied Electromagnetism Laboratory (LMAG) of Escola Politécnica da Universidade de São Paulo, on which the axial movement of the motor secondary drives the suction pump, placed in the down hole of the oil well. In a second step, it was planned to replace the mechanical bearings by two Active Magnetic Bearings (AMB), in order to have better movement and practically no friction, reducing damages caused by impurities in the oil, thus reducing maintenance effort. Nevertheless, the actual prototype has only one AMB, being the other one a mechanical bearing. This paper presents the installation of the second AMB onto TLIM prototype, and a proposal to implement the control algorithm for the TLIM magnetic bearing system, considering now a multivariable problem, where the position of the motor secondary for both AMB are related, as well as control efforts. The present work review the actual system with only one AMB, approaching its physical construction, mathematical model and applied control system; and this control system is applied to the second AMB. A new model is presented, considering the AMB system multivariable behavior, and a multivariable robust control system is then designed, using LQG/LTR approach. Simulation results for the new controller are analyzed and compared to experimental results from the actual controller applied to both AMB, and some conclusions are presented.
32

Realisierung einer prototypischen Hardwarelösung für ein inverses Pendel / FPGA-only Based Closed-loop Control for a Very Compact Inverted Pendulum with Kalman Filter

Berger, Benjamin 17 February 2011 (has links) (PDF)
Ziel der Arbeit ist die anschauliche Demonstration der Leistungsfähigkeit von Hardware- Systemen zur Regelung instabiler Systeme am Beispiel des Inversen Pendels. Dabei handelt es sich um das Balancieren eines Stabes, einem Standard-Problem der Regelungstechnik. Es wird die Konzeption und Implementierung einer Hardware-Regelung in einem FPGA-Prototypenboard zur Realisierung dieser Aufgabe beschrieben. Die Regelung basiert mit LQR-Entwurf und Kalman-Filter auf klassischen Methoden der Regelungstechnik. Zur Demonstration der Regelung wurde ein mechanischer Aufbau vorgenommen, an dem die Funktionsfähigkeit des Inversen Pendels praktisch gezeigt wurde.
33

Controle de sistema de mancais magnéticos ativos para um motor de indução linear tubular. / Control system applied to active magnetic bearings for a tubular linear induction motor.

Leandro Henrique Monaco 08 October 2012 (has links)
Para aplicações de extração de petróleo de poços em terra foi desenvolvido pelo Laboratório de Eletromagnetismo Aplicado (LMAG) da Escola Politécnica da Universidade de São Paulo um protótipo de motor de indução linear tubular (MILT), onde o movimento axial do secundário do motor aciona diretamente a bomba de extração situada no fundo do poço. Numa segunda etapa, foi prevista a substituição dos mancais mecânicos por dois mancais magnéticos ativos (AMBs), que permitem melhor movimentação e praticamente nenhum atrito, reduzindo o desgaste causado por impurezas contidas no petróleo extraído, e consequentemente os esforços de manutenção. Todavia, o protótipo atual possui apenas um mancal magnético, e o outro é mecânico. O presente trabalho apresenta a instalação do segundo mancal magnético ao protótipo do MILT, e propõe realizar o controle do sistema de mancais magnéticos para o MILT, tendo em vista um problema multivariável, onde as posições do secundário do motor em relação aos dois mancais são correlacionadas, bem como as ações de controle sobre os mesmos. O trabalho faz uma revisão do sistema atual com um AMB, abordando sua concepção física, modelagem e o controlador, e tal controlador é replicado para o segundo AMB. Um novo modelo é apresentado, considerando o comportamento multivariável dos dois AMBs, e um sistema de controle robusto multivariável é projetado, através da técnica LQG/LTR. Resultados de simulação do novo controlador são analisados e comparados com os resultados experimentais do controlador atual aplicado aos dois AMBs, e apresentam-se as conclusões. / For onshore oil extraction applications, a tubular linear induction motor (TLIM) prototype was developed by Applied Electromagnetism Laboratory (LMAG) of Escola Politécnica da Universidade de São Paulo, on which the axial movement of the motor secondary drives the suction pump, placed in the down hole of the oil well. In a second step, it was planned to replace the mechanical bearings by two Active Magnetic Bearings (AMB), in order to have better movement and practically no friction, reducing damages caused by impurities in the oil, thus reducing maintenance effort. Nevertheless, the actual prototype has only one AMB, being the other one a mechanical bearing. This paper presents the installation of the second AMB onto TLIM prototype, and a proposal to implement the control algorithm for the TLIM magnetic bearing system, considering now a multivariable problem, where the position of the motor secondary for both AMB are related, as well as control efforts. The present work review the actual system with only one AMB, approaching its physical construction, mathematical model and applied control system; and this control system is applied to the second AMB. A new model is presented, considering the AMB system multivariable behavior, and a multivariable robust control system is then designed, using LQG/LTR approach. Simulation results for the new controller are analyzed and compared to experimental results from the actual controller applied to both AMB, and some conclusions are presented.
34

Recherche, développement et réalisation d'un contrôleur de Fabry-Perot de nouvelle génération / Research, development and realization of a new generation Fabry-Perot controller

Ouattara, Issa 25 June 2015 (has links)
L’équipe Physique des Galaxies du Laboratoire d’Astrophysique de Marseille a développé un nouveau type d'interféromètre de Fabry-Perot, équipé de trois actionneurs piézoélectriques amplifiés et de trois capteurs capacitifs permettant le contrôle de l'espacement et du parallélisme des lames de verres de l'ordre de 200 µm avec une précision de positionnement du nm.L'objectif visé de ce manuscrit, composé de 3 parties, est le pilotage de cet interféromètre. La première partie, composée des chapitres 1 et 2, présente les généralités sur l'interférométrie de Fabry-Perot puis décrit les instruments 3DNTT et BTFI où seront installés l'interféromètre de nouvelle génération et son contrôleur associé. La conception et la réalisation d'un amplificateur hybride en vue de la réduction des non-linéarités des actionneurs piézoélectriques mettent fin à cette partie.La deuxième partie, chapitres 3 et 4, décrit le développement et la réalisation du contrôleur. Pour cela, une démarche basée sur le concept du Co-design a été adoptée.Le contrôleur ainsi réalisé est composé d'une carte de développement Microzed dont le cœur est un système sur puce de la série Zynq 7000 EPP et d'une carte d'interfaçage comportant des convertisseurs 3 ADC et 3 DAC et des circuits d'alimentation. La troisième et dernière partie, chapitres 5 et 6, traite de la modélisation d'état de l’interféromètre de Fabry-Perot et de son contrôle : un contrôle classique basé sur la régulation PID et un contrôle robuste et optimal basé sur le filtrage de KALMAN. Cette dernière partie conclut sur les perspectives pouvant découler des contributions de ce travail sur le contrôle et la commande Fabry-Perot. / The Physics of Galaxies Team of Laboratoire d'Astrophysique de Marseille (LAM) has developed a new type of Fabry-Perot, with three amplified piezoelectric actuators and three capacitive sensors to control the spacing and parallelism of mirror plates of approximately 200 µm with a positioning accuracy of 3 nm.The purpose of this manuscript, consisting of 3 parts is the control of this interferometer.The first part, consisting of Chapters 1 and 2 presents the general interferometry Fabry-Perot and then describes 3DNTT and BTFI instruments which will be installed the next generation interferometer and its associated controller. The design and implementation of a hybrid amplifier to reduce non-linearities of the piezoelectric actuators (hysteresis and creep) end this first part.The second part, Chapters 3 and 4, describes the development and implementation of the controller.For this, an approach based on codesign concept was adopted. The thus achieved controller consists of a Microzed development board whose heart is a system on chip of the 7000 series Zynq EPP (FPGA + Dual-Core ARM Cortex A9) and an interface card with converters (3 ADC and 3 DAC) and power supply circuits.For the finalization of the controller, two steps are necessary: hardware design in Xilinx Vivado and software design in Xilinx SDK.The third and final section, chapters 5 and 6 deals with the Fabry-Perot space-state modeling and its control: a classic control based on PID control and a robust and optimal control based on KALMAN filtering. This last part concludes the outlook may result from contributions of this work on the monitoring and control of the Fabry-Perot.
35

Comparing Control Strategies fora Satcom on the Move Antenna / Jämförelse av reglerstrategier för stabilisering av antenn i mobil satellittjänst

Hellberg, Joakim, Sundkvist, Axel January 2020 (has links)
Satellite communication is a widely known method for communicating with remote or disaster-strickenplaces. Sometimes, thecommunication can be a matter of life and death,and it is thus vital that it works well. For two-way communication (such as internet) it is necessary for the antenna on Earth to point towards the satellite with a pointing error not larger than a few tenths of a degree. For example, regulations decided by the authorities in the U.S. forbid pointing errors larger than 0.5°. In some cases the antenna on Earth has to be moving while satellite communication is maintained. Such cases can be when the antenna is mounted to a vehicle, and the antenna thus has to compensate for the vehicle’s movement in order to point at the satellite. This application of satellite communication is called Satcom on the Move (SOTM). By constructing a Simulink model of an entire SOTM-system, including vehicle dynamics, satellite position, signal behavior, sensors, and actuators, different control strategies can be compared. This thesis compares the performance of an H2- and an LQG-controller for a static initial acquisition case, and a dynamic inertial stabilization case. The static initial acquisition case is performed with a search algorithm (SpiralSearch) aiming to find the satellite signalin the shortest possible time for a given initial pointing error. The dynamic inertial stabilization case is performed by allowing the simulated vehicle to drive in a slalom pattern and over uneven grounds. The controllers are designed based on modern control theory.The conclusion of this thesis is that the H2-controller performs slightly better in the static testcase,whereastheLQG-controller performs slightly better in the dynamic test cases. However, the results are greatly influenced by the tuning of the controllers, meaning that the comparison is not necessarily true for the controllers rather than the tuning parameters. / Satellitkommunikation är en allmänt känd metod för att kommunicera med avlägsna eller katastrofdrabbade platser. Ibland kan kommunikationen vara en fråga om liv och död, och det är därför viktigt att den fungerar bra. För tvåvägskommunikation (som internet) är det nödvändigt att antennen på jorden pekar mot satelliten med ett pekfel som inte är större än några tiondels grader. Exempelvis finns det lagar i USA som förbjuder pekfel större än 0,5°. I vissa fall måste antennen på jorden röra sig medan satellitkommunikation upprätthålls. Sådana fall kan vara när antennen är monterad på ett fordon och antennen således måste kompensera för fordonets rörelse för att peka mot satelliten. Denna applikation av satellitkommunikation kallas Satcom on the Move(SOTM). Genom att konstruera en simulinkmodell av ett fullständigt SOTM-system, inklusive fordonsdynamik, satellitposition, signalbeteende, sensorer och ställdon, kan olika reglerstrategier jämföras. Denna avhandling jämför en H2 - och en LQG-regulator för ett statiskt fall, samt ett dynamiskt fall. Det statiska fallet utförs med en sökalgoritm (spiralsökning) som syftar till att hitta en specifik satellitsignal på kortast möjliga tid för ett givet initialt pekfel. Det dynamiska fallet utförs genom att låta det simulerade fordonet köra i slalommönster och på ojämnt underlag. Regulatorerna är designade baserade på modern kontrollteori.  Slutsatsen av denna avhandling är att H2-regulatorn presterar något bättre i det statiska testfallet, medan LQG-regulatorn presterar något bättre i de dynamiska testfallen. Resultaten påverkas emellertid kraftigt av de designade reglerparametrarna, vilket innebär att jämförelsen inte nödvändigtvis är sann för kontrollerna, utan snarare förde specifika reglerparametrarna.
36

Optimal placement of sensor and actuator for sound-structure interaction system

Suwit, Pulthasthan, Information Technology & Electrical Engineering, Australian Defence Force Academy, UNSW January 2006 (has links)
This thesis presents the practical and novel work in the area of optimal placement of actuators and sensors for sound-structure interaction systems. The work has been done by the author during his PhD candidature. The research is concentrated in systems with non-ideal boundary conditions as in the case in practical engineering applications. An experimental acoustic cavity with five walls of timber and a thin aluminium sheet fixed tightly on the cavity mouth is chosen in this thesis as a good representation of general sound-structure interaction systems. The sheet is intentionally so fixed that it does not satisfy ideal boundary conditions. The existing methods for obtaining optimal sensor-actuator location using analytic models with ideal boundary conditions are of limited use for such problem with non-ideal boundary conditions. The method presented in this thesis for optimal placement of actuators and sensors is motivated by energy based approach and model uncertainty inclusion. The optimal placement of actuator and sensor for the experimental acoustic cavity is used to construct a robust feedback controller based on minimax LQG control design method. The controller is aimed to reduce acoustic potential energy in the cavity. This energy is due to the structure-borne sound inside the sound-structure interaction system. Practical aspects of the method for optimal placement of actuator and sensors are highlighted by experimental vibration and acoustic noise attenuation for arbitrary disturbance using feedback controllers with optimal placement of actuator and sensor. The disturbance is experimentally set to enter the system via a spatial location different from the controller input as would be in any practical applications of standard feedback disturbance rejections. Experimental demonstration of the novel methods presented in this thesis attenuate structural vibration up to 13 dB and acoustic noise up to 5 dB for broadband frequency range of interest. This attenuation is achieved without the explicit knowledge of the model of the disturbance.
37

Conception de lois de commande à hautes performances pour l'optique adaptative des grands / très grands télescopes

Correia, Carlos 18 March 2010 (has links) (PDF)
L'optique adaptative (OA) permet de corriger les effets induits par la turbulence atmosphérique, qui dégradent la résolution des télescopes et donc la qualité des images. Introduits dans les années 1990, les systèmes d'OA deviennent désormais tomographiques, permettant l'analyse du volume turbulent pour une correction à grand champ. Ceci s'accompagne d'une forte augmentation de la complexité des OA des futurs grands télescopes. Les nouveaux concepts d'OA souvent à grands nombres de degrés de liberté (GNDL) requièrent des lois de commande innovantes respectant les contraintes temps réel. Plusieurs aspects originaux sont abordés. Pour les GNDL, le point d'entrée est le choix de la base de représentation de la phase. Deux voies sont explorées : avec une formulation zonale, des méthodes Fourier sont étudiées pour la reconstruction statique de front d'onde ; une nouvelle stratégie combinant méthodes Fourier et méthodes itératives est développée pour adapter la commande optimale linéaire quadratique gaussienne (LQG) aux GNDL. On traite ensuite le problème des dynamiques temporelles des grands miroirs déformables. Pour des dynamiques linéaires, la commande optimale minimisant la variance résiduelle est obtenue comme solution d'un problème LQG à temps discret. Ceci permet aussi de quantifier la dégradation de performances pour des commandes sous-optimales. Cette approche est appliquée à la commande des miroirs de basculement destinés aux grands télescopes. On montre que négliger la dynamique conduit à une dégradation significative des performances. Une autre application est traitée : la coordination d'un miroir lent et d'un miroir rapide (concept woofer-tweeter).
38

Control of Torsionalpendulum on Containercranes / Reglering av torsionspendel på containerkranar

Bäck, Pär January 2004 (has links)
<p>A container crane of STS-type, Ship To Shore, consists of a spreader hanging underneath a railrunning trolly. As the container is under the influence of wind, it is likely that it starts to turn in a torsional pendulum. This report handles how the torsional pendulum of a container crane can be damped. </p><p>A number of different models have been developed to analyze how different placement of the actuators affects the system. Two differens types of controllers, LQG and MPC, have been developed and applied to these models. The different models and controlers were evaluated and compared by studying simulation results in timedomain. Moreover in order to make the simulations more realistic, a wind model has been developed and applied. </p><p>The models and controllers have been analyzed with bodediagrams and sensitivity functions. </p><p>The analyses shows clearly that the best placement of the actuators for control of the torsional pendulum on an STS-crane is in the trolly, pulling and relaxing the wires. This control is best handled by a state feedback control (LQG). Furthermore, the control should in this way, with addition of in the horizontalplane movable suspensions in the trolly, work acceptably in the whole operational area of a STS-crane.</p>
39

Control of Torsionalpendulum on Containercranes / Reglering av torsionspendel på containerkranar

Bäck, Pär January 2004 (has links)
A container crane of STS-type, Ship To Shore, consists of a spreader hanging underneath a railrunning trolly. As the container is under the influence of wind, it is likely that it starts to turn in a torsional pendulum. This report handles how the torsional pendulum of a container crane can be damped. A number of different models have been developed to analyze how different placement of the actuators affects the system. Two differens types of controllers, LQG and MPC, have been developed and applied to these models. The different models and controlers were evaluated and compared by studying simulation results in timedomain. Moreover in order to make the simulations more realistic, a wind model has been developed and applied. The models and controllers have been analyzed with bodediagrams and sensitivity functions. The analyses shows clearly that the best placement of the actuators for control of the torsional pendulum on an STS-crane is in the trolly, pulling and relaxing the wires. This control is best handled by a state feedback control (LQG). Furthermore, the control should in this way, with addition of in the horizontalplane movable suspensions in the trolly, work acceptably in the whole operational area of a STS-crane.
40

Controladores Robustos LQG/LTR com AÃÃo Integral Aplicados ao Controle de Geradores EÃlicos Interligados ao Sistema de DistribuiÃÃo de Energia ElÃtrica Baseados em MÃquinas de InduÃÃo Duplamente Alimentada / Robust Controller LQG/LTR with Integral Action Applied to Control of Wind Generators connected to Distribution Power System based on Doubly Fed Induction Machine

Vandilberto Pereira Pinto 27 January 2012 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Na presente tese, propÃe-se um controlador robusto LQG/LTR (Linear Quadratic Gaussian with Loop Transfer Recovery) com aÃÃo integral (LQG/LTRI) em uma nova aplicaÃÃo para o ajuste dos controladores do conversor do lado da mÃquina e do conversor do lado rede elÃtrica em um sistema de conversÃo eÃlica utilizando um gerador de induÃÃo duplamente alimentado (Doubly-Fed Induction Generator - DFIG). A metodologia de controle proposta assegura a robustez em relaÃÃo à rejeiÃÃo do erro de rastreamento, insensibilidade a variaÃÃes paramÃtricas, alÃm de permitir que erros de medida e modelagem sejam incorporados no projeto. Testes de robustez e desempenho foram realizados para variaÃÃes dos parÃmetros internos da mÃquina e variaÃÃes de referÃncia de velocidade. Resultados de simulaÃÃo e experimentais, obtidos em um protÃtipo de laboratÃrio com uma mÃquina de 2kW sÃo apresentados para validar e demonstrar o bom desempenho e robustez do controlador proposto comparado com os controladores clÃssicos Proporcional-Integral (PI) em um sistema de geraÃÃo eÃlica com mÃquinas DFIG. / It is proposed in this thesis a LQG/LTR robust controller (Linear Quadratic Gaussian with Loop Transfer Recovery) with integral action (LQG/LTRI) in a new application for gain tuning for the rotor side converter and grid side converter in a wind energy conversion system (WECS) with Doubly-Fed Induction Generator(DFIG). The proposed control method assures the robustness with respect to the tracking error rejection, insensitivity to parameter variations and permits that measurement and modeling errors are incorporated in the project. Robustness and performance tests were performed for variations of machine internal parameters and speed. Simulation and experimental results, obtained from a laboratory prototype that uses a 2 kW machine are presented to validate and demonstrate the robustness and performance of the proposed controller through the comparison with the proportional and integral (PI) controller employed in a wind energy conversion system with DFIG.

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