1,726,337 research outputs found
H2, H∞ and H2/H∞ controls applied to an underactuated manipulator robot
No full textEste trabalho apresenta os resultados da aplicação de três técnicas de controle utilizadas no projeto e implementação do controle de um manipulador subatuado planar de três juntas em série e de elos rígidos, projetado e construído pela Universidade Carnegie Mellon, EUA. Devido ao alto grau de não-linearidade deste sistema, seria muito difícil implementar um controlador H2, H∞ ou H2/H∞ que atuasse sozinho. Assim, propõe-se a utilização de um método de controle combinado: torque computado/H2, H∞ ou H2/H∞. No controle combinado, a porção correspondente ao torque computado lineariza e pré-compensa a dinâmica do modelo da planta nominal, enquanto a porção correspondente ao controle H2, H∞ ou H2/H∞ realiza uma pós-compensação dos erros residuais, que não foram completamente eliminados pelo método torque computado. Testes de acompanhamento de trajetória e testes de robustez são realizados aqui para comprovar a eficiência destes controladores, com resultados de implementação bastante satisfatórios.This work presents the application results of three control techniques used for the control design and implementation of a serial planar underactuated manipulator with three joints and rigid links, designed and built by the Carnegie Mellon University, USA. Due to the high non-linearity degree of this system, it would be very difficult to implement an H2, H∞ or H2/ H∞ control which would actuate on the system by itself. Therefore, it is proposed a combined control method: computed torque/ H2, H∞ or H2/H∞. In the combined control, the portion corresponding to the computed torque linearizes and pre-compensates the dynamics of the nominal model, while the portion corresponding to the H2, H∞ or H2/H∞ control realizes a pos-compensation of the residual errors, not completely removed by the computed torque method. Trajetory tracking and robustness tests are performed here to demonstrate the efficiency of these controllers, with very satisfatory implementation results
H2, H∞ and H2/H∞ controls applied to an underactuated manipulator robot
No full textEste trabalho apresenta os resultados da aplicação de três técnicas de controle utilizadas no projeto e implementação do controle de um manipulador subatuado planar de três juntas em série e de elos rígidos, projetado e construído pela Universidade Carnegie Mellon, EUA. Devido ao alto grau de não-linearidade deste sistema, seria muito difícil implementar um controlador H2, H∞ ou H2/H∞ que atuasse sozinho. Assim, propõe-se a utilização de um método de controle combinado: torque computado/H2, H∞ ou H2/H∞. No controle combinado, a porção correspondente ao torque computado lineariza e pré-compensa a dinâmica do modelo da planta nominal, enquanto a porção correspondente ao controle H2, H∞ ou H2/H∞ realiza uma pós-compensação dos erros residuais, que não foram completamente eliminados pelo método torque computado. Testes de acompanhamento de trajetória e testes de robustez são realizados aqui para comprovar a eficiência destes controladores, com resultados de implementação bastante satisfatórios.This work presents the application results of three control techniques used for the control design and implementation of a serial planar underactuated manipulator with three joints and rigid links, designed and built by the Carnegie Mellon University, USA. Due to the high non-linearity degree of this system, it would be very difficult to implement an H2, H∞ or H2/ H∞ control which would actuate on the system by itself. Therefore, it is proposed a combined control method: computed torque/ H2, H∞ or H2/H∞. In the combined control, the portion corresponding to the computed torque linearizes and pre-compensates the dynamics of the nominal model, while the portion corresponding to the H2, H∞ or H2/H∞ control realizes a pos-compensation of the residual errors, not completely removed by the computed torque method. Trajetory tracking and robustness tests are performed here to demonstrate the efficiency of these controllers, with very satisfatory implementation results
Alguns aspectos algébricos e lógicos dos C∞-Anéis
No full textAs pointed out by I. Moerdijk and G. Reyes in [63], C∞-rings have been studied specially for their use in Singularity Theory and in order to construct topos models for Synthetic Differential Geometry. In this work, we follow a complementary trail, deepening our knowledge about them through a more pure bias, making use of Category Theory and accounting them from a logical-categorial viewpoint. We begin by giving a comprehensive systematization of the fundamental facts of the (equational) theory of C∞-rings, widespread here and there in the current literature - mostly without proof - which underly the theory of C∞-rings. Next we develop some topics of what we call a ∞Commutative Algebra, expanding some partial results of [66] and [67]. We make a systematic study of von Neumann-regular C∞-rings (following [2]) and we present some interesting results about them, together with their (functorial) relationship with Boolean spaces. We study some sheaf theoretic notions on C∞-rings, such as ∞(locally)-ringed spaces and the smooth Zariski site. Finally we describe classifying toposes for the (algebraic) theory of ∞ rings, the (coherent) theory of local C∞-rings and the (algebraic) theory of von Neumann regular C∞-rings.Conforme observado por I. Moerdijk e G. Reyes em [63], os anéis C∞ têm sido estudados especialmente tendo em vista suas aplicações em Teoria de Singularidades e para construir toposes que sirvam de modelos para a Geometria Diferencial Sintética. Neste trabalho, seguimos um caminho complementar, aprofundando nosso conhecimento sobre eles por um viés mais puro, fazendo uso da Teoria das Categorias e os analisando a partir de pontos de vista algébrico e lógico-categorial. Iniciamos o trabalho apresentando uma sistematização abrangente dos fatos fundamentais da teoria (equacional) dos anéis C∞, distribuídos aqui e ali na literatura atual - a maioria sem demonstrações - mas que servem de base para a teoria. Na sequência, desenvolvemos alguns tópicos do que denominamos Álgebra Comutativa C∞, expandindo resultados parciais de [66] e [67]. Realizamos um estudo sistemático dos anéis C∞ von Neumann-regulares - na linha do estudo algébrico realizado em [2]- e apresentamos alguns resultados interessantes a seu respeito, juntamente com sua relação (funtorial) com os espaços booleanos. Estudamos algumas noções pertinentes à Teoria de Feixes para anéis ∞, tais como espaços (localmente) ∞anelados e o sítio de Zariski liso. Finalmente, descrevemos toposes classicantes para a teoria (algébrica) dos anéis C∞, a teoria (coerente) dos anéis locais C∞ e a teoria (algébrica) dos anéis C∞ von Neumann regulares
O morfismo de Chern-Weil-Lecomte para L∞-álgebras
No full textIn this thesis we extend the Chern-Weil-Lecomte morphism to the setting of extensions of L∞-algebras together with a representation up to homotopy. This morphism takes values in the L∞-algebra cohomology with coefficients in a graded vector space. We prove that this construction is natural and that the L∞-algebra cohomology is invariant by equivariant L∞-quasi-isomorphisms. As an application we obtain a Chern-Weil-Lecomte morphism for principal 2-bundles over a Lie groupoid that admit a 2-connection form.Nesta tese, estendemos o morfismo de Chern-Weil-Lecomte para o contexto de extensões de L∞-álgebras junto com uma representação a menos de homotopia. Este morfismo toma valores na cohomologia de uma L∞-álgebra com coeficentes em um espaço vetorial graduado. Provamos que esta construção é natural e que a cohomologia é invariante por quasi-isomorfismos equivariantes de L∞-álgebras. Como aplicação obtemos um morfismo de Chern-Weil-Lecomte para 2-fibrados principais sobre grupoides de Lie que admitem uma 2-conexão
Estudos espectroscópicos e estruturais dos polímeros de coordenação 2D, ∞[Tb(DPA)(HDPA)] e ∞[Gd(DPA)(HDPA)] Structural and spectroscopic studies of the 2D coordination polymers, ∞[Tb(DPA)(HDPA)] and ∞[Gd(DPA)(HDPA)]
No full textThis paper presents the synthesis of the coordination polymers ∞[Ln(DPA)(HDPA)] (DPA=2,6-pyridinedicarboxylate; Ln= Tb and Gd), their structural and spectroscopic properties. The structural study reveals that the ∞[Ln(DPA)(HDPA)] has a single Ln+3 ion coordinated with two H2DPA ligands in tridentade coordination mode, while two others H2DPA establish a syn-bridge with a symmetry-related Ln3+, forming a two-dimensional structure. The spectroscopic studies show that ∞[Tb(DPA)(HDPA)] compound has high quantum yield (q x≈ 50.0%), due to the large contribution of radiative decay rate. Moreover triplet level is localized sufficiently over the emitter level 5D4 of theTb3+ ion, avoiding a retrotransference process between these states
H∞-control of differential-algebraic-equation systems
No full textIn this paper H∞ control of high index and non-regular linear differential-algebraic-equation systems is addressed. Based on a generalization of the bounded real lemma (BRL) to index one systems, all linear output feedback controllers in standard, ie non-descriptor, state space form solving the H∞ control problem can be characterized via biaffine matrix inequalities (BMIs). In a second step a congruence transformation and a subsequent change of variables show that certain linear matrix inequalities (LMIs) necessarily must hold in order to admit a solution of the H∞ control problem. However, these conditions are not sufficient. Necessary and sufficient conditions for the existence of a controller solving the H∞ control problem are derived as BMIs of reduced order compared to the original characterization via the BRL. The approach is illustrated by a simple example
Underactuated manipulator robot control via H2, H∞, H2/H∞, and µ-synthesis approaches: a comparative study
No full textABSTRACT This paper deals with robust control of underactuated manipulator robots. It presents a comparative study of four combined controllers H2, H∞ , H2/H∞ and µ-synthesis, pluscomputed torque method. These controllers are applied in an actual underactuated manipulator robot with 3 degrees of freedom, of which joints can be configured as active or passive ones. The study performed in this paper compares the robustness of each controller when different disturbances are considered
On extension of isometries between unit spheres of L∞ and E
No full textIn this paper, we study the extension of isometries between the unit spheres of L∞ and a normed space E. We find a condition under which an isometric mapping between the unit spheres can be extended to a linear isometry on the whole space L∞ .Keywords: Isometric mapping, unit sphere, L∞ Quaestiones Mathematicae 31(2008), 209–21
Antenna Control With Pi, Lqg And H∞ Controllers
No full textTez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2010Bu tez çalışmasının amacı, klasik PI (proportional-and integral) kontrolör ile modern LQG (Doğrusal Kuadratik Gauss) ve H∞ kontrolörlerini Matlab/Simulink’de uydu anten kontrol sistemi için modelleyerek performanslarını gözlemlemektir. Ayrıca, notch filtresi ile PI kontrolörün hibridlenmesi sonucu elde edilen bir kontrolör de anten sistemine uygulanarak performansı diğer kontrol yöntemleriyle kıyaslanmıştır. Çalışmada PI, LQG and H∞ kontrolör özellikleri, performansları, kıyaslamalar ve parametre ayar yaklaşımı sunulmuşur. Anten sistemi matematiksel modeli ile, kontrolör tasarım ve gerçeklenmesi de bu çalışma kapsamındadır. Simülasyonlar PI kontrolörün uygulama olarak kolay olduğunu; sabit ve güvenilir bir performans sergilediğini gösterir. Ancak, bu performans yüksek kazançlarda antende oluşan osilasyonlardan dolayı sınırlıdır. LQG ve H∞ kontrolörler ise daha gelişmiş optimal takip kontrolörlerdir. Bu kontrolörlerin uygulanması ile takip doğruluğu bir adım daha ileri götürülmüş fakat anten donanımından dolayı sınırlanmıştır. Sonuçta hala anten takip doğruluğu yazılıma bağlı olarak sınırlı bir seviyeye kadar performans gösterdiği ve birçok faktörde iyileşme ile arttırılacağı belirtilmiştir. Lineer kontrol durumları tanımlanarak ayrı ayrı dizayn edilen kontrolörlerin performanslarını anlamak için Matlab/Simulink’de simülasyon blokları kurularak tasarımların verimliliği ortaya konulmuştur.The goal of this thesis is to use classical PI (proportional-and integral) and, modern LQG (Linear Quadratic Gaussian) and H∞ controllers, designed via Matlab and Simulink, to manipulate overall antenna system performance. In addition, the performance of the controller, obtained as a result of hybridization of PI controller and notch filters, is compared with other control methods by being applied the antenna system. The properties, performances, comparisons, and tuning of the PI, LQG and H∞ controllers are presented. The mathematical modeling of the antenna control system, and the design and implementation of the controllers are all presented within the context of this study. Simulations show that PI controllers are easy to install and provide stable and reliable performance. However, this performance is limited due to oscillations of the antenna at high gains. H∞ and LQG are more sophisticated optimal tracking controllers. The implementation of these controllers takes the pointing improvement one step further, but is restricted by hardware limitations. After all, antenna-tracking accuracy is still limited due to the software up to a level of performance that can be increased with improvement on many factors. In order to understand the performance of linear control methods, Matlab/Simulink simulation blocks are used to understand the efficiency of different designs.Yüksek LisansM.Sc
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