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[en] AN INTRODUCTION TO ROBUST CONTROL WITH APPLICATIONS TO FLEXIBLE STRUCTURES / [es] INTRODUCCIÓN AL CONTROL ROBUSTO CON APLICACIONES Y EXTRUCTURAS FLEXIBLES / [pt] UMA INTRODUÇÃO AO CONTROLE ROBUSTO COM APLICAÇÕES E ESTRUTURAS FLEXÍVEISCARLOS EDUARDO INGAR VALER 29 August 2001 (has links)
[pt] Este trabalho tem como objetivos principais a apresentação,
análise e síntese de sistemas de controle por realimentação
de saídas com características robustas. São consideradas
incertezas no modelo do tipo não estruturada ( dinâmica não
modelada ) e estruturada ( valores desconhecidos nos
parâmetros ), distúrbios ( entradas desconhecidas ) e
ruídos no sensor. Ênfase especial é dada ao projeto de
sistemas de controle implementados usando observadores de
estado, que representam um tipo especial de sistemas de
controle por realimentação de saídas. Uma revisão dos
principais tipos de observadores é feita, incluíndo
observadores robustos com capacidade de rejeição e
estimação simultânea de distúrbios, comparando suas
características através de um exemplo. Logo após, o sistema
resultante, quando observadores de estado são introduzidos
na lei de controle, é analisado em presença de incertezas,
mostrando a limitação na validade do Princípio da
Separação. Técnicas modernas de controle robusto são usadas
para melhorar as propriedades de robustez dos sistems de
controle, entre elas: Recuperação da Função de
Transferência da Malha (LTR) e Controle H-infinito. É
mostrado também, que através de uma escolha conveniente dos
parâmetros livres do controle LQG, é possível sintetizar
controladores robustos. Estas técnicas são usadas para
resolver problemas específicos no controle de estruturas
flexíveis, incluíndo perturbações na entrada da planta,
incertezas paramétricas. As técnicas aplicadas no presente
trabalho demonstram eficácia e simplicidade. / [en] This work intends to present an introduction to the
analysis and syntesis of output feedback control systems
with robust characteristics. They are considered
unstructured ans structured model uncertainties,
disturbances, unknown inputs and noise. It is given a
special emphasys on the control systems which were
implemented by the use of state observers, which represents
a special type of output feedback control systems. A review
of the principais types of observers are done, including
robust observers with interesting characteristics such as
the capacity of simultaneous rejection and estimation of
disturbances, and their features are compared in an
example. After that, it is done an analysis of the
resultant systems when state observers are introduced in
the control system in the presence of uncertainties,
showing limitations to apply the Separation Principle.
Modern techniques of robust control are used to enhance the
properties of robustness of the control systems, such as
Loop Transfer Recovery (LTR) technique and H(infinito)
control.It is also shown that an adequate choice of the
free parameters in the LQC control allows to synthetize
robust controllers. These techniques are used to solve
specific problems in the control of flexible structures,
including disturbances in the plant input, uncertainties
caused by unmodeled dynamic in high frequency ( spillover
problem ) and parametric uncertainties. The techniques
applied in this work show effectiveness and simplicity. / [es] Este trabajo tiene como objetivos principales la
presentación, análisis y síntesis de sistemas de control
por realimentación de salidas con características robustas.
Son consideradas incertidumbres en el modelo del tipo no
extructurada (dinámica no modelada) y extructurada (valores
desconocidos en los parámetros), distúrbios (entradas
desconocidas) y ruidos en el sensor. Se le dedica especial
atención al proyecto de sistemas de control que fue
implementado utilizando observadores de estado, que
representan un tipo especial de sistemas de control por
realimentación de salidas. Se realiza una revisión de los
principales tipos de observadores, incluyendo observadores
robustos con capacidad de rechazo y estimación simultánea
de disturbios, comparando sus características a través de
un ejemplo. Seguidamente se analiza, en presencia de
incertidumbre, el sistema que resulta al introducir
observadores de estado en la ley de control, mostrando las
limitaciones en la validez del Principio de la Separación.
Se utilizan técnicas modernas de control robusto para
mejorar las propriedades de robustez de los sistems de
control, entre ellas: Recuperación de la Función de
Transferencia de la Malla (LTR) y Control H-infinito. Se
muestra también, que a través de una selección conveniente
de los parámetros libres del control LQG, es posible
sintetizar controladores robustos. Estas técnicas se
utilizan para resolver problemas específicos en el control
de extructuras flexibles, incluyendo perturbaciones en la
entrada de la planta e incertidumbres paramétricas. Las
técnicas aplicadas en este trabajo demuestran eficiencia y
simplicidad.
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Modélisation et commande de microrobots magnétiquement guidés dans le système cardiovasculaire / Modeling and control of a magnetically guided microrobot in cardiovascular systemArcese, Laurent 22 November 2011 (has links)
La chirurgie minimalement invasive est aujourd’hui une thématique de recherche particulièrement active. Un traitement thérapeutique ciblé et la possibilité d’établir un diagnostic précis grâce à l’utilisation de systèmes miniaturisés peuvent considérablement améliorer de nombreuses pratiques médicales. Le recours à des microrobots actionnés à distance et naviguant dans le système cardiovasculaire ouvre de nouvelles perspectives. L’objectif de cette thèse est de proposer un socle théorique solide concernant i) la modélisation d’un microrobot naviguant dans le système cardiovasculaire, ii) l’élaboration de lois de commande et d’observateurs assurant un bon suivi de trajectoire depuis la zone d’injection jusqu’à une zone cible. La modélisation du système fait intervenir de nombreuses forces : forces hydrodynamiques, forces surfaciques (électrostatique, van der Waals, stériques), forces de contact et poids apparent du microrobot. Ce microrobot est contrôlé dans le système cardiovasculaire par l’application de champs ou de gradients de champ magnétique selon le design du microrobot. La prise en compte de l’ensemble des forces aboutit à une représentation d’état sous la forme d’un système non-linéaire affine en la commande avec dérive comportant de nombreux paramètres physiologiques incertains. Une trajectoire de référence optimisée est déduite du modèle. L’approche de commande adoptée est établie à partir de critères de stabilité du système. Le système étant non-linéaire, une commande de type Lyapunov stabilisante est développée suivant une approche de type backstepping. L’estimation de certains paramètres physiologiques est rendue possible par une commande de type backstepping adaptatif. Un observateur grand gain reconstruit l’état complet du système nécessaire au calcul de la commande. La stabilité et la robustesse de l’ensemble sont établies au travers de nombreuses simulations en présence de bruits de mesure et d’erreurs paramétriques. / Minimally invasive medical procedures are currently an active research aera. A drug targeted therapy and the possibility of establishing an accurate diagnosis through the use of miniaturized systems can greatly improve many medical practices. The use of untethered microrobots navigating in the cardiovascular system opens new perspectives. The objective of this PhD work is to provide a theoretical approach on i) the modeling of a microrobot navigating in the cardiovascular system, ii) the development of control laws and observers to ensure a fine tracking from the injection to a target area. Modeling such as system involves many forces : hydrodynamic forces, surface forces (electrostatic, van derWaals, steric), contact forces and apparent weight of the microrobot. This microrobot is controlled in the cardiovascular system by the application of magnetic fields or magnetic field gradients according to the design of the microrobot. The consideration of all the forces leads to a state representation in the form of a nonlinear system with many physiological uncertain parameters, but gives us sufficient informations to plan an optimal trajectory. The control approach is established based on stability consideration. A Lyapunov-stabilizing control is then developed using a backstepping approach. An adaptive backstepping control law estimates some physiological parameters. A high gain observer reconstructs the full state of the system required for implementing the control approach. Robustness and stability of the controller with respect to noise measurement, parameters variations and uncertainties are illustrated by simulations.
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Máquinas, inscrições e observador : o problema da visualização do conhecimento numa abordagem sistêmicaDiehl, Rafael January 2010 (has links)
Nesta tese, argumenta-se que as inscrições são a interface a partir da qual é possível considerar metodologicamente a condição de observadores na visualização do conhecimento. Para isso, considera-se os limites dos sistemas formais, a crise da representação e o modelo da Máquina de Turing como afirmações da condição encarnada do conhecer. Nesse contexto, a noção de informação mostra-se indício de uma transição paradigmática entre um modelo de conhecimento representacional, no qual a posição de um observador frente às representações não entra na configuração analisada, e um modelo sistêmico, que exige a consideração de diferentes níveis de organização e suas limitações que emergem da autorreferência. Propõe-se a noção superfície de inscrição para abordar a relação entre operatividades mecânicas, como a encontrada nos computadores, e o domínio consensual da linguagem que permite explicar um mundo entendido como realidade. Essa noção é forjada como um artifício teóricometodológico para evitar, em contextos educativos e de pesquisa, a reificação de uma posição frente aos quadros explicativos que reforça dicotomias tipo natureza-cultura e deslegitima o potencial enunciativo de qualquer ser humano. O artifício é proposto em três campos de análise e legibilidade: o campo das condições técnicas das superfícies; a estabilização de uma posição de observação diante das superfícies de inscrição; e o contexto político do uso de tais superfícies para compartilhar e explicar. / On this thesis, we discuss that the inscriptions are the interface from which it is possible to consider the conditions of observers methodologically on the knowledge visualization; therefore, we consider the formal systems limits, the representation crisis, and the Turing Machine Model as affirmations of the embodied condition of knowledge. In this context, the notion of information proves to be an indicative of a paradigmatic shift from a representational model of knowledge, in which the position of an observer in the face of representations does not infer the configuration that was analyzed, and a systemic model, which demands consideration of different levels of organization and its limitations that emerge from self-reference. We propose the notion of inscription surface to tackle the relation of different kinds of mechanical operability, as the one found in computers, and the consensual domain of language that helps one to explain a world perceived as reality. This notion is forged as a theoretic-methodological stratagem to avoid, in educational and research contexts, the reification of a position related to the explanatory frameworks that reinforces dichotomies such as nature-culture and delegitimizes the enunciative potential of any humanbeing. The stratagem is proposed in three fields of analysis and readability: the field of technical conditions of the surfaces; a position of observation stabilization on the inscription surfaces, and the political context of the use of such surfaces to share and explain.
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Landscape, memory and secrecy : the Cold War archaeology of the Royal Observer CorpsClarke, Robert January 2016 (has links)
This project covers the development of a model framework intended to allow researchers of the archaeology of the Cold War to recognise a range of behaviours played out on military sites. The order and chaos model developed and utilised in this thesis introduces a heterotopian landscape populated by the Royal Observer Corps. Through a process of archaeological fieldwork a number of behavioural traits are recognised and discussed here for the first time. The group in question is fully researched, providing a historiography of the practice played out during the groups life-cycle. The landscape archaeology is discussed and contextualised by narration from the volunteers who once operated the posts. A range of case studies are introduced confirming the validity of the order and chaos model and potential for application elsewhere. Finally, the findings are discussed in detail and a proposal for the next step in the research are revealed.
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Máquinas, inscrições e observador : o problema da visualização do conhecimento numa abordagem sistêmicaDiehl, Rafael January 2010 (has links)
Nesta tese, argumenta-se que as inscrições são a interface a partir da qual é possível considerar metodologicamente a condição de observadores na visualização do conhecimento. Para isso, considera-se os limites dos sistemas formais, a crise da representação e o modelo da Máquina de Turing como afirmações da condição encarnada do conhecer. Nesse contexto, a noção de informação mostra-se indício de uma transição paradigmática entre um modelo de conhecimento representacional, no qual a posição de um observador frente às representações não entra na configuração analisada, e um modelo sistêmico, que exige a consideração de diferentes níveis de organização e suas limitações que emergem da autorreferência. Propõe-se a noção superfície de inscrição para abordar a relação entre operatividades mecânicas, como a encontrada nos computadores, e o domínio consensual da linguagem que permite explicar um mundo entendido como realidade. Essa noção é forjada como um artifício teóricometodológico para evitar, em contextos educativos e de pesquisa, a reificação de uma posição frente aos quadros explicativos que reforça dicotomias tipo natureza-cultura e deslegitima o potencial enunciativo de qualquer ser humano. O artifício é proposto em três campos de análise e legibilidade: o campo das condições técnicas das superfícies; a estabilização de uma posição de observação diante das superfícies de inscrição; e o contexto político do uso de tais superfícies para compartilhar e explicar. / On this thesis, we discuss that the inscriptions are the interface from which it is possible to consider the conditions of observers methodologically on the knowledge visualization; therefore, we consider the formal systems limits, the representation crisis, and the Turing Machine Model as affirmations of the embodied condition of knowledge. In this context, the notion of information proves to be an indicative of a paradigmatic shift from a representational model of knowledge, in which the position of an observer in the face of representations does not infer the configuration that was analyzed, and a systemic model, which demands consideration of different levels of organization and its limitations that emerge from self-reference. We propose the notion of inscription surface to tackle the relation of different kinds of mechanical operability, as the one found in computers, and the consensual domain of language that helps one to explain a world perceived as reality. This notion is forged as a theoretic-methodological stratagem to avoid, in educational and research contexts, the reification of a position related to the explanatory frameworks that reinforces dichotomies such as nature-culture and delegitimizes the enunciative potential of any humanbeing. The stratagem is proposed in three fields of analysis and readability: the field of technical conditions of the surfaces; a position of observation stabilization on the inscription surfaces, and the political context of the use of such surfaces to share and explain.
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Utilização de modelos de falhas e observadores de estado em estruturas reticuladas /Watanabe, Larissa. January 2010 (has links)
Orientador: Gilberto Pechoto de Melo / Banca: Amarildo Tabone Paschoalini / Banca: Yukio Kobayashi / Resumo: Nos últimos anos, tem havido um grande interesse das indústrias no desenvolvimento de novas técnicas de detecção e localização de falhas, pois se preocupam cada vez mais com a segurança, havendo assim, a necessidade de supervisão e monitoramento dos sistemas para que as falhas sejam evitadas ou sanadas o mais rápido possível. Determinados parâmetros em sistemas reais como massa, rigidez e amortecimento, podem variar devido ao aparecimento de falhas ou ao próprio desgaste natural dos componentes. Um aparecimento de trincas pode provocar perdas econômicas ou até conduzir a situações perigosas com paradas abruptas das máquinas e/ou equipamentos. Através do auxílio de modelos teóricos bem definidos, métodos de identificação de parâmetros, observadores de estado e auxílio à decisão foi possível desenvolver uma metodologia para detecção e localização de trincas em estruturas reticuladas, dando ênfase às tridimensionais. Foi possível detectar e localizar a trinca já no seu início e acompanhar sua propagação para uma possível parada programada. Foi utilizada a metodologia dos observadores de estado, que pode reconstruir os estados não medidos ou os valores provenientes de pontos de difícil acesso no sistema. Foi construída uma estrutura reticulada no Laboratório para validação da metodologia desenvolvida e os resultados foram bastante satisfatórios / Abstract: In recent years there has been a great interest of industry in developing new techniques for detection and location of faults, because they worry more about security, so there is the need for supervision and monitoring systems so that failures are avoided or remedied as soon as possible. Certain parameters in real systems such as mass, stiffness and damping can vary due to some failures to own or wear and tear of components. An appearance of cracks can cause economic loss or even lead to dangerous situations with abrupt stopping of machines and/or equipment. Through the aid of well-defined theoretical models, methods of parameter identification, state observers and aid the decision was possible to develop a methodology for detecting and locating cracks in frame structures, emphasizing the three-dimensional. It was possible to detect and locate the crack already in its early stages and monitor its spread to a possible shutdown. Methodology was applied for observer status, which can reconstruct the unmeasured states or values from points of difficult access in the system. A reticulated structure was built at the Laboratory for validation of the methodology and the results were very satisfactory / Mestre
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State Estimation for Truck and Trailer Systems using Deep Learning / Tillståndsskattning med hjälp av djupinlärning för lastbilar med dolly och semitrailerArnström, Daniel January 2018 (has links)
High precision control of a truck and trailer system requires accurate and robust state estimation of the system. This thesis work explores the possibility of estimating the states with high accuracy from sensors solely mounted on the truck. The sensors used are a LIDAR sensor, a rear-view camera and a RTK-GNSS receiver. Information about the angles between the truck and the trailer are extracted from LIDAR scans and camera images through deep learning and through model-based approaches. The estimates are fused together with a model of the dynamics of the system in an Extended Kalman Filter to obtain high precision state estimates. Training data for the deep learning approaches and data to evaluate and compare these methods with the model-based approaches are collected in a simulation environment established in Gazebo. The deep learning approaches are shown to give decent angle estimations but the model-based approaches are shown to result in more robust and accurate estimates. The flexibility of the deep learning approach to learn any model given sufficient training data has been highlighted and it is shown that a deep learning approach can be viable if the trailer has an irregular shape and a large amount of data is available. It is also shown that biases in measured lengths of the system can be remedied by estimating the biases online in the filter and this improves the state estimates.
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Máquinas, inscrições e observador : o problema da visualização do conhecimento numa abordagem sistêmicaDiehl, Rafael January 2010 (has links)
Nesta tese, argumenta-se que as inscrições são a interface a partir da qual é possível considerar metodologicamente a condição de observadores na visualização do conhecimento. Para isso, considera-se os limites dos sistemas formais, a crise da representação e o modelo da Máquina de Turing como afirmações da condição encarnada do conhecer. Nesse contexto, a noção de informação mostra-se indício de uma transição paradigmática entre um modelo de conhecimento representacional, no qual a posição de um observador frente às representações não entra na configuração analisada, e um modelo sistêmico, que exige a consideração de diferentes níveis de organização e suas limitações que emergem da autorreferência. Propõe-se a noção superfície de inscrição para abordar a relação entre operatividades mecânicas, como a encontrada nos computadores, e o domínio consensual da linguagem que permite explicar um mundo entendido como realidade. Essa noção é forjada como um artifício teóricometodológico para evitar, em contextos educativos e de pesquisa, a reificação de uma posição frente aos quadros explicativos que reforça dicotomias tipo natureza-cultura e deslegitima o potencial enunciativo de qualquer ser humano. O artifício é proposto em três campos de análise e legibilidade: o campo das condições técnicas das superfícies; a estabilização de uma posição de observação diante das superfícies de inscrição; e o contexto político do uso de tais superfícies para compartilhar e explicar. / On this thesis, we discuss that the inscriptions are the interface from which it is possible to consider the conditions of observers methodologically on the knowledge visualization; therefore, we consider the formal systems limits, the representation crisis, and the Turing Machine Model as affirmations of the embodied condition of knowledge. In this context, the notion of information proves to be an indicative of a paradigmatic shift from a representational model of knowledge, in which the position of an observer in the face of representations does not infer the configuration that was analyzed, and a systemic model, which demands consideration of different levels of organization and its limitations that emerge from self-reference. We propose the notion of inscription surface to tackle the relation of different kinds of mechanical operability, as the one found in computers, and the consensual domain of language that helps one to explain a world perceived as reality. This notion is forged as a theoretic-methodological stratagem to avoid, in educational and research contexts, the reification of a position related to the explanatory frameworks that reinforces dichotomies such as nature-culture and delegitimizes the enunciative potential of any humanbeing. The stratagem is proposed in three fields of analysis and readability: the field of technical conditions of the surfaces; a position of observation stabilization on the inscription surfaces, and the political context of the use of such surfaces to share and explain.
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IMPROVEMENTS IN INVERTER MODELING AND CONTROLLiu, Xiao 01 January 2017 (has links)
In this dissertation, the generalized averaging method models for inverters, reactive power control methods for photovoltaic inverters, and a noise immunity improvement for hybrid position observers for brushless dc motor drives are studied.
Models of inverters and other converters based on averaging have been widely used in numerous simulation applications. Generalized averaging can be applied to model both average and switching behavior of converters while retaining the faster run times associated with average-value models. Herein, generalized average models for single- and three-phase pulse width modulation inverters are proposed. The modulation signal for the proposed model could be either a sinusoidal waveform without high order harmonics or a sinusoidal waveform with third-harmonic injection. And this generalized average models also can apply for modeling three-phase pulse width modulation inverters with varying modulation signal frequency in the reference frame. These models are based on a quasi-Fourier series representation of the switching functions that includes fundamental and switching frequency components as well as sideband components of the switching frequency. The proposed models are demonstrated both in simulation and experimentally and are found to accurately portray both the fundamental and the switching behavior of the inverter. In particular, the use of sideband components allows accurate representation of the variation in switching ripple magnitude that occurs in the steady state. The generalized average models are found to have simulation run times that are significantly faster than those associated with detailed models. Therefore, the proposed generalized average models are suitable for simulation applications in which both accuracy (including the switching behavior) and fast run times are required (e.g., long simulation times, systems with multiple converters, and repeated simulations).
Variations in the output power of intermittent renewable sources can cause significant fluctuations of distribution system voltage magnitudes. Reactive power control methods that employ the reactive power capability of photovoltaic three-phase inverters to mitigate these fluctuations are proposed. These control methods cause the three-phase inverters to substitute reactive output power for real output power when fluctuations in the solar power are experienced, allowing the fluctuations to be controlled. Performance metrics for assessing the ability of these controllers to perform this mitigation are defined. The controllers are examined using the IEEE 123-bus feeder distribution system, and it is found that the controllers can effectively mitigate voltage magnitude fluctuations and that the appropriate choice of controller depends on the performance metrics of interest.
Finally, a noise immunity improvement for hybrid position observers for brushless dc motor drives is proposed. A finite state machine is used to detect Hall-effect sensor transitions to determine if these transitions are true transitions or the result of momentary glitches. This filter causes a delay in the detection of the Hall-effect sensors that is compensated in the proposed observer. The proposed observer is compared in simulations with the original hybrid position observer under both non-noisy and noisy conditions for both constant and variable speed operation, and it has good performance even under high noise and variable speed conditions.
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A Journey Through the Land of Model-View-* Design PatternsSyromiatnikov, Artem January 2014 (has links)
Every software program that interacts with a user requires a user interface. Model-View-Controller (MVC) is a common design pattern to integrate a user interface with the application domain logic. MVC separates the representation of the application domain (Model) from the display of the application's state (View) and user interaction control (Controller). However, studying the literature reveals that a variety of other related patterns exists, which we denote with Model-View-* (MV*) design patterns. This thesis discusses existing MV* patterns classified in three main families: Model-View-Controller (MVC), Model-View-View Model (MVVM), and Model-View-Presenter (MVP). We take a practitioners' point of view and emphasize the essentials of each family as well as the differences. The study shows that the selection of patterns should take into account the use cases and quality requirements at hand, and chosen technology. We illustrate the selection of a pattern with an example of our practice. The study results aim to bring more clarity in the variety of MV* design patterns and help practitioners to make better grounded decisions when selecting patterns.
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