Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-02-24T14:44:47Z No. of bitstreams: 1 marceloribeiro.pdf: 3015247 bytes, checksum: 325fa8dffab659edce18dc9c5f1f485c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-02-24T15:39:52Z (GMT) No. of bitstreams: 1 marceloribeiro.pdf: 3015247 bytes, checksum: 325fa8dffab659edce18dc9c5f1f485c (MD5) / Made available in DSpace on 2017-02-24T15:39:52Z (GMT). No. of bitstreams: 1 marceloribeiro.pdf: 3015247 bytes, checksum: 325fa8dffab659edce18dc9c5f1f485c (MD5) Previous issue date: 2013-04-01 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A construção de edifícios, especialmente os mais esbeltos, requer uma análise apurada do comportamento dinâmico da estrutura. Tais estruturas são sujeitas a movimentos induzidos pelo vento, entre outras forças, o que pode causar efeitos indesejáveis tais como desconforto para os usuários ou até mesmo causar o colapso estrutural. Neste cenário, os sistemas de controle são utilizados a fim de atenuar a vibração excessiva. Dentre estes sistemas, aqueles que utilizam respostas dinâmicas das estruturas para a determinação das forças de controle, de um modo geral, quando adequadamente construídos, têm um desempenho satisfatório. Pode-se destacar o sistema de controle com retroalimentação. No entanto, o uso desses controladores em edifícios requer uma certa quantidade de testes e simulações, uma vez que os problemas em qualquer fase do processo de controle pode transformar um controlador ativo em um excitador, o que obviamente não é desejável. Neste trabalho foi realizada uma análise numérica de um modelo de sistema estrutural sujeito a forças dinâmicas de vento, onde as vibrações foram controladas por meio de um sistema de controle ativo. As forças de excitação foram obtidas por análise da fluidodinâmica computacional e as forças de controle foram obtidas aplicando a técnica de controle ótimo. Esta etapa constitui uma das primeiras fases do projeto de um controle. / The construction of buildings, especially the most slender, requires a detailed analysis of the structural dynamic behavior. Such structures are subject to movements induced by the wind and other forces, which can cause undesirable effects such as discomfort for the user or even cause the structural collapse. In this scenario, control systems are used to mitigate excessive vibration. Among these systems, those using dynamic responses of the structures to determine control forces, in general, when properly constructed, have satisfactory performance as control systems with feedback. However, the use of these controllers in buildings requires a certain amount of tests and simulations, since problems at any stage of the control process, may transform an active controller into an excitator, which is obviously undesirable. In this work a numerical analysis of a structural model subject to dynamic wind forces was performed. The excitation forces were obtained by computational uid dynamics analysis and control forces were obtained by applying the technique of optimal control. The present analysis is one of the first phases of a control design.

Orientador: Alberto Luiz Serpa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-25T12:10:51Z (GMT). No. of bitstreams: 1 CanahuireCabello_RuthVanessa_D.pdf: 5994310 bytes, checksum: 0f754dbcbe2bce27101f33806ca7f190 (MD5) Previous issue date: 2014 / Resumo: A síntese de controle H-infinito de estruturas flexíveis pode levar à obtenção de controladores de alta ordem. Estes controladores podem apresentar dificuldades para a implementação prática acarretando atrasos de resposta no sistema. Para evitar esse problema, este trabalho apresenta duas sínteses de controladores H-infinito de ordem reduzida por realimentação de saída. Para este propósito, são formulados dois problemas de otimização para a obtenção de controladores de ordem reduzida considerando que as matrizes de estado do controlador estão na forma canônica controlável e canônica modal. As duas sínteses propostas estão baseadas na minimização da norma H-infinito garantindo a estabilidade do sistema em malha fechada. Outro problema considerado neste trabalho são os efeitos de saturação dos atuadores sobre o sistema controlado. A saturação, quando presente no sistema, pode levar a uma perda de desempenho e as vezes à instabilidade da planta. Para tratar o problema de saturação é proposto um problema de otimização baseado no projeto de compensadores anti-windup. A abordagem proposta usa a síntese do problema H-infinito para minimizar diretamente os efeitos do sinal de saturação sobre o sinal de desempenho. Finalmente, as formulações são verificadas no controle ativo de vibração sobre um modelo teórico e em uma bancada experimental com uma viga de alumínio engastada-livre. Os métodos mostraram ter bom desempenho garantindo a estabilidade do sistema em malha fechada. Os problemas de otimização são resolvidos usando algoritmos genéticos e alguns aspectos numéricos são discutidos / Abstract: The H-infinity controller synthesis for flexible structures leads to full-order controllers. This can represent difficulties for practical controller implementation arising delay in the system response. To avoid this difficulty, this work presents two reduced order H-infinity controllers synthesis based on output feedback. For this goal, it is formulated two optimization problem to obtain a reduced order controller in its state-space controllable canonical form and state-space modal canonical form. The two proposed synthesis are based on the minimization of the H-infinity norm ensuring the stability of the closed loop system. Another problem considered in this work is related to the effects of saturation of the actuators on the controlled system. The saturation in the system can lead to a performance loss and occasionally to the instability of the plant. An optimization problem based on anti-windup compensator design is proposed to treat this problem. The proposed approach uses the H-infinity controller synthesis to minimize directly the saturation effects on the performance signal. Finally, the formulations are verified in the active control of vibration of a theoretical model and a cantilever aluminium beam is used on an experimental bench. The methods proposed presented good performance in terms of the stability of the closed loop system. The optimization problems are solved using genetic algorithms and some numerical aspects are discussed / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutora em Engenharia Mecânica

Orientador: Paulo Roberto Gardel Kurka / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T11:40:22Z (GMT). No. of bitstreams: 1 Izuka_JaimeHideo_D.pdf: 4550690 bytes, checksum: d283c500cecbc7a038784ba35f0f73df (MD5) Previous issue date: 2013 / Resumo: A utilização de braços manipuladores flexíveis em veículos de exploração foi o motivador deste trabalho. Estas estruturas têm como vantagens a sua massa reduzida e a capacidade de suportar grandes deformações sem que o limite de elasticidade seja excedido. O controle das vibrações de sua extremidade livre é essencial para uma aplicação prática. Neste contexto, este trabalho tem como objetivo a determinação de um modelo dinâmico para uma estrutura longa e flexível, visando o seu controle de vibração. A estrutura considerada possui seção variável, semelhante a uma viga telescópica. Considera-se ainda que a estrutura esteja sujeita a uma grande deformação causada pelas ações de tendão de tração, peso próprio e cargas concentradas. O modelo dinâmico consiste na adaptação de uma malha de elementos finitos de baixa ordem à configuração da linha de deformação estática da viga. A vibração a ser controlada consiste das pequenas oscilações que ocorrem em torno da posição de equilíbrio da viga deformada. O modelo dinâmico encontrado para a estrutura é utilizado no projeto de um controlador de vibrações, ativado por forças exercidas no tendão de tração, responsável pela deformação estática da própria viga. Comparações com a literatura, bem como resultados experimentais comprovam a validade do modelo empregado para a caracterização do sistema. Simulações numéricas mostram o sucesso de uso do modelo no projeto de um controlador ativo de vibrações / Abstract: The use of flexible manipulator arms in exploration vehicles was the motivation of this work. The advantages of such structures are their light weight and the capability to withstand large displacements without exceeding their specified elastic limit. The control of vibrations of its free end is essential for a practical application. In this context, the objective of this study is to determine a dynamic model for a long and flexible structure, aiming its vibration control. The structure has a variable section, similar to a telescopic beam. Large deformation behavior of the structure is considered. Concentrated loads, self-weight of the structure and tendon traction are the loads applied to the structure. The model dynamics is described by a low order finite element mesh, which is adapted to the geometry defined by the static deformation of the beam. The vibrations to be controlled are the small oscillations about the equilibrium position of the deformed beam. The dynamic model found for the structure is applied to design an active vibration controller. The controller forces are applied though the tendon traction cables, which is also responsible for the static deformation of the beam itself. Comparison with literature as well as experimental results prove the validity of the model used to characterize the system. Numerical simulations show the success of using the model in the design of an active vibration controller / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

Orientador: Alberto Luiz Serpa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica. / Made available in DSpace on 2018-08-20T02:31:41Z (GMT). No. of bitstreams: 1 Mourao_KellenTazianiFernandes_M.pdf: 2493356 bytes, checksum: 4d9ad466fb48ec6e3f81311c9fd467b1 (MD5) Previous issue date: 2012 / Resumo: Neste trabalho foi utilizado o controle H'infinito' para atenuar vibrações em estruturas mecânicas. São utilizadas desigualdades matriciais lineares para encontrar o controlador ótimo. Sensores e atuadores são incorporados ao projeto e para determinar o melhor local onde devem ser fixados na estrutura são utilizadas duas metodologias: uma pela menor norma H'infinito' de malha fechada e a outra pela maior norma H''infinito' de malha aberta. Para modelar a estrutura a ser controlada é usado o método de elementos finitos. Após determinadas as posições ótimas para alocar sensores e atuadores, foram projetados controladores H''infinito' com filtros de ponderação escolhidos via algoritmos genéticos. Para projetar o controlador H'infinito' utilizou-se o modelo reduzido da planta, desconsiderando os modos residuais. São escolhidos filtros de ponderação via algoritmos genéticos para determinar as faixas de frequência de interesse com o intuito de projetar um controlador menos conservador e evitar o fenômeno de spillover, e consequentemente, que a malha fechada se torne instável. Os exemplos de aplicação foram realizados sobre uma estrutura flexível do tipo viga. Os resultados mostraram que os controladores projetados, após o posicionamento ótimo de sensores e atuadores e escolhidas das funções de ponderação via algoritmos genéticos, minimizaram a amplitude de vibração da estrutura garantindo a estabilidade do sistema / Abstract: In this work it was used the H'infinite' control to atenuate vibrations in mechanical structures. Linear matrix inequalities are used to find the optimal controller. Sensors and actuators are incorporated into the project. To determine the best place to allocate them in the structure two methods are used: the first is based on the highest closed-loop H'infinite' norm and the second is based on the lowest open-loop H'infinite' norm. The structure to be controlled was modeled through the finite element method. After determining the optimal placement to allocate sensors and actuators, the loop was closed and H'infinite' controllers were designed with weighting filters that were chosen via genetic algorithms for both cases of positioning. To design the H'infinite' controller, a reduced model of the plant was used, disregarding the residual modes. Weighting filters are found through genetic algorithms to determine the frequency bands of interest in order to design a controller with less conservatism and avoiding the phenomenon of spillover, and consequently, unstable closed loop. The application examples were based in a flexible beam structure. The results showed that the designed controllers, after the optimal placement of sensors and actuators and choosing the best parameters for the weighting functions, minimized the amplitude of vibration of the structure, ensuring system stability / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

L'observation des exoplanètes pose deux problèmes : le contraste entre la planète et l'étoile et leur très faible séparation. L'une des techniques permettant de résoudre ces difficultés est l'interférométrie en frange noire : deux pupilles sont recombinés pour faire une interférence destructive sur l'étoile, et leur base est réglée pour que l'interférence soit constructive sur la planète. Cependant, pour garantir une extinction suffisante de l'étoile, la différence de trajet optique entre les faisceaux doit être de l'ordre du nanomètre, et le pointage meilleur que le centième de tache d'Airy, malgré les perturbations extérieures.Pour valider les points critiques d'une telle mission spatiale, un démonstrateur de laboratoire, PERSÉE, a été défini par un consortium dirigé par le CNES et incluant l'IAS, le LESIA, l'ONERA, l'OCA et Thales Alenia Space puis intégré à l'Observatoire de Meudon. Ce banc simule une mission spatiale dans son ensemble (interféromètre et cophasage nanométrique). Son objectif est de délivrer et maintenir une extinction de 10^-4 stabilisé à mieux que 10^-5 sur plusieurs heures, en présence de perturbations typiques que l'on injecte.Mon travail de thèse a consisté à intégrer le banc en étapes successives et à développer des procédures d'étalonnage. Ceci m'a aidé à caractériser les différents éléments critiques séparément avant de les regrouper. Après avoir mis en œuvre les boucles de contrôle du cophasage, leur analyse précise m'a permis de réduire à 0,3 nm rms le résidu de différence de marche, et à 0,4 % de la tache d'Airy le résidu de tip/tilt, malgré la présence de perturbations d'une dizaine de nanomètres d'amplitude, constituées de plusieurs dizaines de fréquences vibratoires entre 1 et 100 Hz. Cela a été possible grâce à l'implémentation d'un contrôleur linéaire quadratique gaussien, paramétré par la mesure préalable de la perturbation pour la réduire au maximum. Grâce à ces très bons résultats, j'ai pu obtenir un taux d'extinction record sur la bande [1,65 – 2,45] µm de 8,8x10^-6 stabilisé à 9x10^-7 sur quelques heures, soit une décade meilleure que les spécifications initiales. L'extrapolation de ces résultats au cas d'une mission spatiale montre que les performances attendues sont atteignables si le flux disponible est suffisamment important. Avec des télescopes de 40 cm et une fréquence d'asservissement de l'ordre de 100 Hz, des étoiles de magnitude inférieure à 9 devraient être observables. / There are two problems with the observation of exoplanets: the contrast between the planet and the star and their very low separation. One technique solving these problems is nulling interferometry: two pupils are recombined to make a destructive interference on the star, and their base is adjusted to create a constructive interference on the planet. However, to ensure a sufficient extinction of the star, the optical path difference between the beams must be around the nanometer, and the pointing must be better than one hundredth of Airy disk, despite the external disturbances.To validate the critical points of such a space mission, a laboratory demonstrator, PERSÉE, was defined by a consortium led by CNES, including IAS, LESIA, ONERA, OCA and Thales Alenia Space and integrated in Meudon Observatory. This bench simulates the entire space mission (interferometer and nanometric cophasing system). Its goal is to deliver and maintain an extinction of 10^-4 stable at better than 10^-5 over a few hours in the presence of typical injected disturbances.My thesis work consisted in integrating the bench in successive stages and to develop calibration procedures. This helped me to characterize the critical elements separately before grouping them. After having implemented the control loops of the cophasing system, their precise analysis helped me to reduce down to 0.3 nm rms the residual OPD, and 0.4 % of the Airy disk the residual tip/tilt, despite disturbances of tens of nanometers, consisting of several tens of vibrational frequencies between 1 and 100 Hz. This has been achieved by the implementation of a linear quadratic Gaussian controller, parameterized by the preliminary measurement of the disturbance to minimize. Thanks to these excellent results, I obtained on the band [1.65 – 2.45] µm a record null rate of 8.8x10^-6 stabilized at 9x10^-7 over a few hours, a decade better than the original specifications. An extrapolation of these results to the case of a space mission shows that the expected performance is achievable if the available flux is sufficiently important. With telescopes of 40 cm and a control frequency around 100 Hz, stars brighter than magnitude 9 should be observable.

New materials and new fabrication techniques in turbomachinery lead to monolithic<p>structures with extremely low damping which may be responsible for severe vibrations<p>and possible high-cycle fatigue problems. To solve this, various techniques<p>of damping enhancement are under investigation. The present work is focused on<p>piezoelectric shunt damping.<p>This thesis considers the RL shunt damping of rotationally periodic structures using<p>an array of piezoelectric patches, with an application to a bladed drum representative<p>of those used in turbomachinery. Due to the periodicity and the cyclic symmetry of<p>the structure, the blade modes occur by families with very close resonance frequencies,<p>and harmonic shape in the circumferential direction; the proposed RL shunt<p>approaches take advantage of these two features.<p>When a family of modes is targeted for damping, the piezoelectric patches are<p>shunted independently on identical RL circuits, and tuned roughly on the average<p>value of the resonance frequencies of the targeted modes. This independent<p>configuration offers a damping solution effective on the whole family of modes, but<p>it requires the use of synthetic inductors, which is a serious drawback for rotating<p>machines.<p>When a specific mode with n nodal diameters has been identified as critical and<p>is targeted for damping, one can take advantage of its harmonic shape to organize<p>the piezoelectric patches in two parallel loops. This parallel approach reduces considerably<p>the demand on the inductors of the tuned inductive shunt, as compared<p>to independent loops, and offers a practical solution for a fully passive integration<p>of the inductive shunt in a rotating structure.<p>Various methods are investigated numerically and experimentally on a cantilever<p>beam, a bladed rail, a circular plate, and a bladed drum. The influence of blade<p>mistuning is also investigated. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Dans les générateurs de vapeurs (GV), les tubes du circuit primaire sont sujets aux chocs et aux forces de couplage auto-excitatrices nommées forces fluides élastiques.Il est crucial, lors du dimensionnement des GV, de maîtriser la dynamique de ces tubes, ainsi que d'estimer au mieux les efforts mécaniques auxquels ils sont soumis.En effet, cela permet aux ingénieurs d'optimiser la durée de vie des installations et d’augmenter le rendement des centrales électriques.Le but de la présente thèse est de trouver une technique d'essai hybride, basée sur le contrôle actif des vibrations, pour reproduire la contribution modale des forces de couplage sur un tube. En effet, les expériences en milieu réel, dans les conditions que l'on trouve dans les GV, sont hors de prix et très difficiles à reproduire. Dans ces travaux de recherche, une structure de test interagit avec un modèle numérique, qui modélise le fluide, à travers un système de contrôle actif en temps réel. Dans un premier temps les efforts mécaniques appliqués sur le tube sont caractérisés, puis un système de contrôle, constitué de transducteurs et de la carte de contrôle, est conçu pour générer les forces de couplage sur le tube, en prenant en considération les non-linéarités dues aux impacts. / In steam generators, the primary loop tubes are subjected to fluid-elastic couplingforces and impacts. Understanding the dynamic of these tubes is crucial when designingsteam generators. Mastering coupling and impacts forces would allow engineers toimprove the design of structure components and would optimize the tube lifetime, whileimproving the overall performances of power plant.The aim of the current research is to provide a hybrid test technique reproducingthe modal coupling forces on a tube, since experiments on fluid are expensive anddifficult to set up. In this work, the experimental structure interacts with a numericalmodel (which models the fluid-elastic coupling forces) via a real time controller and aset of transducers. First, we characterize the coupling and impact forces, and then, anactive vibration control approach is set up to reproduce the modal contribution of fluidelasticforces on the tube, taking in consideration the non-linearities due to the impacts.

Le domaine des matériaux intelligents et des structures adaptatives constitue un domaine de recherche consacré à la conception de structures architecturées ayant la faculté de modifier leur comportement en réponse à un stimulus externe. Le travail proposé dans cette thèse porte sur l’analyse et la conception d’un système pour le contrôle vibroacoustique adaptatif. Il s’attache à la conception d’une interface active faite de transducteurs piézo-électriques disposés en réseau bidimensionnel. Chaque transducteur est shunté individuellement par un circuit électronique externe synthétisant une capacité négative. Cette stratégie de contrôle se base sur le couplage multipysique entre la plaque et les circuit électroniques mis en communication et permet de contrôler les ondes se propageant au sein de la structure. Le dispositif ainsi créé est qualifié de métacomposite. La performance du metacomposite a été évaluée par le biais de nombreux essais numériques et expérimentales. Du point de vue modélisation, l’analyse a été réalisée à l’aide du théorème de Bloch adapté aux systèmes piézo-élastiques à deux dimensions. Par la suite, une procédure d’optimisation a été utilisée dans le but de sélectionner les paramètres de shunt électrique les plus appropriés.Un prototype du guide d’ondes a été fabriqué et testé. Les résultats montrent clairement que ce dispositif permet de modifier les propriétés vibratoires de la structure porteuse, que ce soit en terme d’atténuation ou de trasmission. Enfin, un modèle éléments finis de la plaque a été utiliser afin d’évaluer la robustesse de la stratégie de contrôle proposée vis-à-vis d’une modification des paramètres du circuit, de la topologie del’interface active ou des propriétés de la plaque contrôlée. / Smart materials is an active research area devoted to the design of structured materials showingphysical properties that can be modified in response to an external stimulus.This study focuses on the analysis and design of adaptive system for vibroacoustic control. Theresearch investigates the design of a active interface made of piezoelectric transducers arranged ina two-dimensional lattice. Each transducer is individually shunted to an external electric circuitsynthesizing a negative capacitance effect. It allows to control waves propagating inside a structuretaking advantage of the multi-field coupling between the structural plate and the electrical circuitsshunting the piezoelectric patches.The performance of the metacomposite has been evaluated through numerous numerical andexperimental tests. The smart wave-guide has been analyzed by using the Bloch theorem appliedto two-dimensional piezo-elastic systems. Subsequently an optimization procedure has been usedwith the purpose to select the most appropriate set of circuit’s parameters.A prototype of the smart waveguide has been manufactured and tested. The results results clearlyshow the filtering and attenuating capabilities of this device.Finally a finite element model of the finite extent smart plate has been considered in order toasses the robustness of the proposed control strategy respect to a modification of the circuit’sparameters, the topology of the active interface and the properties of the controlled plate.A brief review conclude the work delineating which aspects of the design should be modified inorder to obtain a device suitable for industrial applications.

Cette thèse se propose d’appliquer un contrôle actif modal aux instruments de musique de la famille des cordes. Les objectifs principaux sont de proposer une démarche et des méthodes adaptées permettant l’application de ce type de contrôle, d’explorer les possibilités qu’il offre et d’en étudier les effets sur les instruments. Tout d’abord, les types de contrôle existants et leurs applications aux instruments de musique sont rapidement présentés. Le constat que les paramètres modaux des instruments sont de bons descripteurs de ses attributs perceptifs mène à choisir la méthode de contrôle actif modal dont le formalisme est présenté. Afin de répondre à des problématiques propres aux instruments de musique, comme par exemple modifier l’amplitude de vibration des modes de la structure, des méthodes dérivées d’un contrôle d’état modal sont proposées. Une méthode d’adimensionnement en temps du modèle utilisé dans le système de contrôle ainsi qu’une méthode de contrôle des états dérivé et proportionnel sont présentées. Le contrôle est ensuite appliqué expérimentalement sur un monocorde, une guitare et un violoncelle. Pour cela, un système de contrôle temps réel fonctionnant grâce à un environnement libre est développé. Les possibilités offertes par ce type de contrôle ainsi que ses limites sont explorées grâce à ces montages expérimentaux. Enfin, un cas particulier de phénomène régissant le fonctionnement des instruments de musique à cordes est étudié à l’aide du dispositif de contrôle proposé. Le couplage corde/table d’harmonie est observé, étudié analytiquement puis contrôlé. Afin de confronter le contrôle actif à d’autres méthodes d’investigation, les résultats du contrôle sont comparés à ceux obtenus à l’aide d’une méthode de synthèse sonore. / This PhD thesis deals with modal active control applied to string musical instruments. Its main goals are to propose an approach and adapted methods to apply this kind of control, to investigate its possibilities and to study its effects on musical instruments. First, a short presentation of the different methods of active control and their applications to musical intruments is done. While the modal parameters of musical instruments are believed to be good descriptors of their perceptual attributs, the modal active control method is chosen for this work. Adapted methods from modal state control are used to answer to specific issues related to musical instruments. To modify the amplitude of the vibration modes, a time-dimensionless model and a derivative and proportionnal modal state method are proposed. Then, these control methods are experimentally applied to a single string instrument, a guitar and a cello. A real time control system based on a free and opensource framework is developped. The possibilities and the limits of modal state control are studied using this experimental setup. Finally, a case of a complex phenomenon contributing to the sound production in string instruments is studied thanks to the developped control system. The coupling between the string and the soundboard is observed, analytically studied and controlled. The results obtained with control and with a synthesis method are studied to compare this two investigation methods.

[pt] O controle passivo de vibrações em edifícios usando absorsores pendulares tem sido bastante estudado na literatura técnica e usado na pratica em edifícios altos como o Taipei-101 em Taiwan. Como a frequência do pêndulo depende apenas do seu comprimento e da aceleração da gravidade, para sintonizar a frequência do pêndulo com a do edifício, tem-se como única variável de projeto o comprimento do pêndulo. Entretanto, em muitos casos, o comprimento necessário e o espaço requerido não se coadunam com o projeto. Nestes casos pode-se substituir o pêndulo clássico por um sistema pendular equivalente composto por uma massa que se movimenta sobre uma superfície curva, permitindo maior flexibilidade no projeto do absorsor, já que o comprimento do pêndulo torna-se irrelevante e a forma da superfície curva pode ser otimizada. Em virtude do movimento da massa sobre a superfície curva, novas forças de inércia e amortecimento não encontradas no pêndulo clássico podem aparecer. No presente trabalho um sistema pendular composto de uma massa que se desloca através de suportes rolantes sobre uma superfície curva é proposto para controle das oscilações de estruturas sob excitação de base. Este sistema pendular tem a vantagem de poder ser usado tanto como um amortecedor pendular de massa sintonizada (APMS) quanto como isolador de base pendular (IBP). Como o sistema pendular pode, em certos casos, apresentar grandes rotações, barreiras que limitam o movimento são propostas, gerando forças de impacto cuja eficiência no controle de vibrações é aqui investigada. / [en] The passive vibration control of buildings using pendulum absorber has been extensively studied in the technical literature and used in high buildings such as the Taipei-101 in Taiwan. Since the frequency of the pendulum depends only on its length and the acceleration of gravity, to tune the frequency of the pendulum to that of the building, its length is the sole design variable. However, in many cases, the pendulum length and the space required for its installation are not consistent with the design. In these cases one can replace the classic pendulum with an equivalent pendulum system comprising a mass that moves on a curved surface, allowing greater flexibility in the absorber design as the length of pendulum becomes irrelevant and the shape of the curved surface can be optimized. Because of the mass movement on the curved surface, new inertia and stiffness forces not found in the classic pendulum may appear. In the present work a pendulum system comprising a mass that moves through rolling bearings on a curved surface is proposed for control of the oscillations of structures under base excitation. This pendulum system has the advantage of being used both as a pendulum tuned mass damper (APMS) and as a base isolation pendulum system (IBP). As the pendulum system can, in certain cases, display large rotations, barriers which limit its movement are proposed, generating impact forces whose efficiency in vibration control is here investigated.