A ideia de usar redes neurais biologicamente inspiradas na computação tem sido amplamente utilizada nas últimas décadas. O fato essencial neste paradigma é que um neurônio pode integrar e processar informações, e esta informação pode ser revelada por sua atividade de pulsos. Ao descrever a dinâmica de um único neurônio usando um modelo matemático, uma rede pode ser implementada utilizando um conjunto desses neurônios, onde a atividade pulsante de cada neurônio irá conter contribuições, ou informações, da atividade pulsante da rede em que está inserido. Neste trabalho é apresentado um controlador de posição no eixo Z utilizando fusão de sensores baseado no paradigma de Redes Neurais Recorrentes. O sistema proposto utiliza uma Máquina de Estado Líquido (LSM) para controlar o robô colaborativo BAXTER. O framework foi projetado para trabalhar em paralelo com as LSMs que executam trajetórias em formas fechadas de duas dimensões, com o objetivo de manter uma caneta de feltro em contato com a superfície de desenho, dados de sensores de força e distância são alimentados ao controlador. O sistema foi treinado utilizando dados de um controlador Proporcional Integral Derivativo (PID), fundindo dados de ambos sensores. Resultados mostram que a LSM foi capaz de aprender o comportamento do controlador PID em diferentes situações. / The idea of employing biologically inspired neural networks to perform computation has been widely used over the last decades. The essential fact in this paradigm is that a neuron can integrate and process information, and this information can be revealed by its spiking activity. By describing the dynamics of a single neuron using a mathematical model, a network in which the spiking activity of every single neuron will get contributions, or information, from the spiking activity of the embedded network. A positioning controller based on Spiking Neural Networks for sensor fusion suitable to run on a neuromorphic computer is presented in this work. The proposed framework uses the paradigm of reservoir computing to control the collaborative robot BAXTER. The system was designed to work in parallel with Liquid State Machines that performs trajectories in 2D closed shapes. In order to keep a felt pen touching a drawing surface, data from sensors of force and distance are fed to the controller. The system was trained using data from a Proportional Integral Derivative controller, merging the data from both sensors. The results show that the LSM can learn the behavior of a PID controller on di erent situations.

La diversité des maladies des patients de réanimation fait que l’environnement technologique de soins intensifs est composé de nombreux systèmes de monitorage de constantes physiologiques, permettant à l’équipe soignante de déterminer un traitement adapté au patient. De plus en plus de systèmes ont une fonction d’assistance à la prescription ou aux soins afin de réduire la charge de travail et mentale des infirmières exigées par certains traitements ou protocoles. Ces systèmes informatisés facilitent l’intégration du protocole et de l’information disponible dans les signaux et peuvent aboutir à des systèmes de complexité élevée. La question de l’évaluation de la qualité de la réalisation et de la balance bénéfice/risque pour les patients liée à l’usage de nouveaux systèmes d’assistance se pose alors. Un problème consiste à mener cette évaluation a priori dès la conception du protocole ou de l’algorithme. Ce travail de thèse donne un exemple de méthode pour un système d’assistance au contrôle de la glycémie des patients de réanimation : l’évaluation est menée depuis la conception de l’algorithme de contrôle jusqu’à une étude clinique de grande ampleur. L’origine du dispositif étudié vient de ce que les patients présentent souvent une hyperglycémie liée au stress à leur arrivée en réanimation (l’augmentation de l’insulino-résistance, l’administration de certaines de drogues ou la déficience en insuline inhibent la réponse physiologique à l’augmentation de la glycémie). Un problème vient alors de ce que, d’une part, l’hyperglycémie prolongée étant associée à une morbidité voire une mortalité accrue, contrôler la glycémie est bénéfique, et d’autre part réduire la glycémie fait courir le risque d’épisodes hypoglycémiques pendant le séjour en réanimation. Dans ce cas, optimiser la balance bénéfice/risque est encore un problème ouvert. Bien qu’il existe de nombreux travaux sur la modélisation de la pharmacodynamique du système glucose-insuline, peu de travaux exploitent ces modèles pour fournir un système de contrôle fonctionnel, testé et industrialisable. La thèse présente un système de contrôle glycémique ainsi qu’une méthode d’évaluation généralisable à d’autres systèmes, qui teste numériquement les performances techniques et cliniques de ce type de systèmes sur des patients virtuels. Les résultats d’une étude clinique réelle sont aussi présentés. / The variety of ICU patients diseases implies that technological environment of critical care is composed of many vital signs monitoring systems, allowing the medical team to determine appropriate treatment to the patient. More and more systems have a decision-making support function to reduce the mental and physical workload of nurses required for certain treatments or protocols. These computerized systems facilitate the integration of the protocol and the information available in the signals and can lead to systems of high complexity. The issue of assessing the performances and the benefit/risk balance for the patient related to the use of new support systems arises. The problem is to conduct this evaluation a priori, during the design process of the protocol or algorithm. This work provides an example of a method to support the control of blood glucose in the ICU system evaluation is conducted for the design of the control algorithm to a large-scale clinical study.The origin of the studied device comes from the fact that patients often experience hyperglycemia due to stress upon their arrival in the ICU (increased insulin resistance, administration of interacting drugs or insulin deficiency inhibit the physiological response to the blood sugar increase). A problem then is that, on the one hand, as sustained hyperglycemia is associated with an increased morbidity or mortality, controlling glycaemia reduces risks, but, on the other hand, reducing blood sugar exposes to the risk of hypoglycemia during the ICU stay. In this case, optimizing benefit/risk ratio is still an open problem.Although there are many studies on modeling the pharmacodynamics of glucose-insulin system, few works use these models to provide a functional, tested and industrialized control system. The thesis presents a glycemic control system and a generalized method of evaluation with other systems, which tests digitally technical and clinical performances of such systems on virtual patients. The results of a real clinical trial are also presented.

De manière générale, les turbomachines sont des machines tournantes permettant la conversion des différents types d’énergie. Ces dernières sont composées d’une partie mécanique en rotation, appelée rotor, interagissant avec un fluide. La rotation a donc un rôle clé pour ces machines et la liaison entre les parties fixes et les parties tournantes, appelée palier, est primordiale pour un fonctionnement fiable et optimal. Les turbomachines supportées par des paliers magnétiques actifs (PMAs) sont de plus en plus utilisées par les industriels notamment grâce à l’absence de contact direct entre parties fixes et parties tournantes, permettant un gain d’énergie et une réduction des émissions de CO2. La plupart du temps, ces machines sont « embarquées » et reposent sur des supports mobiles. Les mouvements générés par ces supports doivent être considérés dans la prévision du comportement dynamique des turbomachines afin d’améliorer les designs en conséquence. Cette thèse est une contribution à l’étude des turbomachines supportées par des PMAs sujettes à de fortes sollicitations extérieures. L’approche est numérique et expérimentale. L’utilisation d’un banc d’essais académique composé d’un système rotor-PMA, aux propriétés d’une turbomachine industrielle, a permis de tester les modèles développés pour des cas de sollicitations extérieures de type séisme et choc, générées grâce à l'excitateur 6-axes de l'equipex PHARE. Il est montré que le modèle permet la bonne prévision du comportement réel de la machine. Cet outil pourra donc être utilisé pour des designs de type industriel. / Turbomachines are rotating machines enabling the conversion of the different types of energy. The latter are composed of a rotating mechanical part, called rotor, interacting with a fluid. Therefore, rotation play a key role in these machines and the mechanical link between the fixed and the rotating parts, called bearing, is essential for reliable and optimal operations. Turbomachines supported by active magnetic bearings (AMBs) are increasingly used by industrial companies, especially thanks to the absence of direct contact between fixed and rotating parts, enabling energy savings and reduction of CO2 emissions. Most of the time, these machines are "on-board" and are fixed on mobile supports. The motions generated by these supports must be considered in the prediction of the dynamic behaviour of turbomachinery in order to improve the designs accordingly. This PhD is a contribution to the study of turbomachines supported by AMBs subjected to strong external base motions. The approach is numerical and experimental. The use of an academic scale test rig comprising a rotor-AMB system, with the properties of an industrial turbomachine, allowed to test the developed models for cases of external solicitations such as earthquake and shock, thanks to the 6-axis shaker of the equipex PHARE. It is shown that the model provides good predictions of the behaviour of the machine for the tested cases. This tool can therefore be used for industrial designs.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-07-18T19:13:43Z No. of bitstreams: 1 HiltonSantos.pdf: 3137200 bytes, checksum: a7b77b12eeb29959ab49e7ef675229d9 (MD5) / Made available in DSpace on 2017-07-18T19:13:43Z (GMT). No. of bitstreams: 1 HiltonSantos.pdf: 3137200 bytes, checksum: a7b77b12eeb29959ab49e7ef675229d9 (MD5) Previous issue date: 2017-06-27 / The emergence of new industrial plants with great complexity and the need to improve the operation of existing plants has fostered the development of high performance control systems, these systems must not only meet the design specifications, such as merit figures, but also operate at minimal cost and impacts at environment. Motivated by this demand, it is presented in this dissertation the development of methods for on-line tuning of control system parameters, ie, a methodology is presented for the on-line tuning of adaptive and optimal PID controllers via Artificial Neural Networks(ANNs). The approach developed in this dissertation is based on three PID controllers parameters. [Artificial neural networks with radial base functions and Model Predictive Control (MPC). From the union of these approaches a general formulation of an Adaptive-optimal PID controller via artificial neural networks with on-line tuning was presented. The on-line tuning methodology for the ANN parameters is presented in the context of MPC, predicting plant output. For the PID controller, we proposed a modification of the standard structure in order to adapt the error function. The adjustment of the PID controller parameters and the prediction of the optimally plant output, are performed by the ANN-RBF weights adjustments. In addition, an indoor implementation of the control system were proposed for the positioning of a photovoltaic panel. The performance evaluations of the proposed system were obtained from computational experiments results that were based on mathematical models and hardware experiments, that were obtained from a reduced model of a photovoltaic panel. Finally, a comparison between the proposed methodology with the classical PID controller were performed and the proposed methodology presented to be more flexible to the insertion of new performance metrics and the results achieved from the ANN, were better than the ones obtained by the classical PID tuning, such as: Ziegler-Nichols or trial and error. / O surgimento de novas plantas industriais com grande complexidade e a necessidade de melhorar a operação das plantas já existentes tem fomentado o desenvolvimento de sistemas de controle de alto desempenho, estes sistemas devem atender não só as especificações de projeto, tal como: figuras de mérito, mas também devem operar com um custo mínimo e sem causar impactos desastrosos para o meio ambiente. Motivados por esta demanda, apresenta-se nesta dissertação o desenvolvimento de métodos para sintonia online dos parâmetros dos sistemas de controle, ie, apresenta-se uma metodologia para a sintonia online de controladores PID adaptativo e ótimo via Redes Neurais Artificiais (RNAs). A abordagem desenvolvida nesta dissertação tem base as ações dos controladores PID de três termos, redes neurais artificiais com funções de base radial e Controle preditivo baseado em modelo (MPC - Model Predictive Control), a partir da união destas abordagens elabora-se a formulação geral do controlador PID Adaptativo-Ótimo via redes neurais artificiais, com sintonia online. A metodologia de ajuste online dos parâmetros da RNA está no contexto do MPC para predição de saída da planta. Para o caso do controlador PID, tem-se a modificação da estrutura padrão com o objetivo de adaptação em função do erro. O ajuste dos termos do controlador PID e da predição da saída na planta, de forma ótima, é realizada pelo ajustes dos pesos da RNA-RBF. Além disso, apresenta-se a implementação indoor do sistema de controle desenvolvido para o posicionamento de um painel fotovoltaico. As avaliações de desempenho do sistema proposto são obtidos de resultados de experimentos computacionais que são baseados em modelos matemáticos e experimentos em hardware que são obtidos de um modelo reduzido de um painel fotovoltaico. Por fim, comparando o PID clássico com o controlador desenvolvido constatou-se que este último apresenta mais flexibilidade para inserir novas métricas de desempenho e os resultados atingidos são melhores do que os parâmetros obtidos por meio da sintonia do PID clássica, tais como: métodos de Ziegler-Nichols ou tentativa e erro

Η παρούσα διδακτορική διατριβή αναφέρεται σε έδρανα ολίσθησης. Συγκεκριμένα, αναφέρεται στο σχεδιασμό και την κατασκευή ενός νέου, πρωτότυπου υβριδικού εδράνου ολίσθησης, το οποίο έχει τη δυνατότητα να λειτουργεί είτε ως υδροδυναμικό, είτε ως ενεργό ηλεκτρομαγνητικό, είτε ως υβριδικό, δηλαδή υδροδυναμικό και ενεργό ηλεκτρομαγνητικό ταυτόχρονα. Προκειμένου να πραγματοποιηθεί ο σχεδιασμός και η κατασκευή του συγκεκριμένου υβριδικού εδράνου ολίσθησης, έγιναν υπολογισμοί και προσομοίωση του υδροδυναμικού πεδίου για τα υδροδυναμικά έδρανα ολίσθησης και του ηλεκτρομαγνητικού πεδίου για τα ηλεκτρομαγνητικά έδρανα στο πρόγραμμα ANSYS. Η προσομοίωση των υβριδικών εδράνων ολίσθησης έγινε με επαναληπτική διαδικασία μεταξύ του υδροδυναμικού και του ηλεκτρομαγνητικού πεδίου προκειμένου να υπολογίζεται το κάθε επιθυμητό μέγεθος. Για το σχεδιασμό του υβριδικού εδράνου ολίσθησης χρησιμοποιήθηκε το σχεδιαστικό πρόγραμμα CATIA. Για την προσομοίωση του ελέγχου του υβριδικού εδράνου ολίσθησης, χρησιμοποιήθηκε το πρόγραμμα Matlab, το οποίο ενεργοποιεί το πρόγραμμα Ansys για τον υπολογισμό των χαρακτηριστικών του υδροδυναμικού και του ηλεκτρομαγνητικού πεδίου του εδράνου και το Simulink module του Matlab για τον υπολογισμό των χαρακτηριστικών του ελέγχου, ώστε να γίνονται όλοι οι απαραίτητοι υπολογισμοί αυτοματοποιημένα. Τέλος, έγιναν υπολογισμοί και προσομοίωση δυναμικής περιστρεφόμενων αξόνων, με στήριξη του ρότορα σε δύο έδρανα και δίσκο προσαρμοσμένο στον ρότορα, στο πρόγραμμα Matlab, με σύνδεση με το Ansys για τον υπολογισμό των συντελεστών ελαστικότητας και απόσβεσης και το Simulink module του Matlab για τον υπολογισμό των χαρακτηριστικών του ελέγχου, με σκοπό την ολοκληρωμένη ανάλυση του συστήματος. Συμπερασματικά, μέσω της συγκεκριμένης διδακτορικής διατριβής αποδεικνύεται πως ο σχεδιασμός, η λειτουργία και η κατασκευή του συγκεκριμένου πρωτότυπου υβριδικού εδράνου ολίσθησης είναι εφικτά, και από τα αποτελέσματα προκύπτει πως η λειτουργία ενός τέτοιου υβριδικού εδράνου ολίσθησης, έχει πολλά πλεονεκτήματα σε σχέση με άλλα έδρανα στήριξης περιστρεφόμενων αξόνων, είτε αυτά είναι απλά είτε υβριδικά και μπορεί να εφαρμοστεί είτε σε εργαστηριακό επίπεδο είτε σε βιομηχανικές εφαρμογές. / The present doctoral thesis refers to hydrodynamic journal bearings. Specifically, it refers to the design and construction of a new, innovative hybrid journal bearing, which has the ability to function either as hydrodynamic or active magnetic or hybrid, i.e. both hydrodynamic and active magnetic, at the same time. In order to be performed the design and construction of the specific hybrid journal bearing, calculations and simulation of the hydrodynamic field for the hydrodynamic journal bearings in the program ANSYS, have been made. The simulation of the hybrid journal bearings has been made with iterative process, between the hydrodynamic and active magnetic field, so that every desired magnitude can be calculated. For the design of the hybrid journal bearing, the designing program CATIA has been used. For the simulation of the control of the hybrid journal bearing, the program Maltab has been used, which activates the program Ansys, for the calculation of the features of the hydrodynamic and active magnetic field of the bearing and the Simulink module of Maltab, for the calculation of the features of control, so that all necessary calculations can be made automated. Finally, calculations and simulation of rotor dynamics, with support of the rotor in two bearings and disc adjusted to the rotor, in Maltab, in connection to Ansys, for the calculation of the elastic and damping coefficients and the Simulink module of Maltab, for the calculation of the features of control, have been made, having as a purpose the complete analysis of the system. In conclusion, through the specific doctoral thesis, it is proved that the design, function and construction of the specific, new hybrid journal bearing, can be achieved and the results show that the function of such a hybrid journal bearing, has many advantages compared to other bearings of support of rotors, either they are simple or hybrid and it can be applied either to laboratory level or industrial applications.

This master thesis deals with the virtual gate position and liquid level control system. The main characteristics of automatic control systems, fuzzy logic systems, their properties and formation principles are reviewed. Conventional and advanced control methods are presented pointing out their benefits, drawbacks and problems to be solved. Physical modelling and simulation issues are also discussed. Physical, mathematical, simulation and animation models of the system are produced. Position and level controllers are designed. The simulation of gate position and liquid level control processes is performed. The simulation model is built up using MATLAB Simulink and Fuzzy Logic Toolbox. The simulation results prove that the proportional controller fits very well for controlling gate position. However, the results of liquid level control “upwards” using PI controller are only satisfactory. Unsatisfactory results are obtained using the same controller for liquid level control “downwards”. Substantially better results are achieved using fuzzy logic controller. The models produced can be useful for further investigations and learning purposes.

Depuis la création des moteurs à combustion interne, les recherches sur les moteurs essence et diesel se sont développées indépendamment. Afin de réduire les temps et les coûts de développement d’un moteur, une approche unifiée de conception serait intéressante. Dans ce cadre, le contrôle et la mise au point des moteurs à combustion interne pourrait être elle aussi unifiée. Bien évidemment, ce contrôle doit être stable, robuste vis-à-vis des disparités de fabrication, comme de fonctionnement. Cette thèse porte alors sur une démarche unifiée, pour les moteurs essence comme pour les moteurs diesel, afin d’obtenir un contrôle robuste de la chaîne d’air du moteur. La chaîne d’air du moteur contient les éléments permettant de contrôler la quantité et les proportions d’air et de gaz neutres dans le cylindre (Recirculation des gaz d’échappement, papillon d’admission, turbocompresseur). Cette démarche unifiée de commande, permettant de contrôler les systèmes monovariables, tout comme multivariables non carrés (nombre d’entrées différent du nombre de sorties), contient plusieurs étapes : identification d’un modèle du système, analyse du système permettant d’en déduire une structure de contrôle, synthèse d’un contrôleur autour d’un nominal, vérification de la robustesse en stabilité, tests du contrôle. Le couplage des entrées vers les sorties, les non linéarités sont pris en compte lors de la synthèse du contrôleur. Cette méthode de conception a été validée sur plusieurs applications dont un moteur essence et un moteur diesel. Des résultats expérimentaux sur un banc moteur diesel haute dynamique ont montrés que la commande multivariable permettait de réduire les émissions d’oxydes d’azote. / Since the creation of internal combustion engines, research on gasoline and diesel engines were developed independently. To reduce the time and cost of developing an engine, a unified design approach would be interesting. In this context, control and development of internal combustion engines could also be unified. Obviously, this control must be stable, robust with respect to manufacturing disparities and operating points. This thesis then focuses on a unified approach for gasoline engines as well as diesel engines, to achieve a robust of the air path. The engine air path contains the information needed to control the amount and proportions of air and neutral gases in the cylinder (exhaust gas recirculation, throttle valve, turbocharger). This unified approach to control monovariable systems, as well as non-square multivariable systems (number of inputs different from the number of outputs), consists of several steps: identification of a model of the system, system analysis to deduce a control structure, synthesis of a controller around a nominal model, check robust stability, control tests. The coupling inputs to outputs and nonlinearities are taken into account during the synthesis of the controller. This design method has been validated in several applications including a gasoline engine and a diesel engine. Experimental results on a diesel engine high dynamics test bench have shown that the multivariable control results in lower emissions of nitrogen oxides.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-11-08T12:05:44Z No. of bitstreams: 1 JOSÉ NILTON SILVA - TESE (PPGEQ) 2013.pdf: 1910479 bytes, checksum: 59c6bfc5fdbee46bc17470e9b2c8c2e5 (MD5) / Made available in DSpace on 2018-11-08T12:05:44Z (GMT). No. of bitstreams: 1 JOSÉ NILTON SILVA - TESE (PPGEQ) 2013.pdf: 1910479 bytes, checksum: 59c6bfc5fdbee46bc17470e9b2c8c2e5 (MD5) Previous issue date: 2013-08-01 / Este trabalho trata do desenvolvimento de uma metodologia baseada nos conceitos clássicos de estatística e probabilidade para a análise e avaliação da robustez da estabilidade e do desempenho de sistemas de controle, particularmente àqueles que usam o PID (Proporcional, Integral, Derivativo) como lei de controle. Visando estabelecer as condições para a aplicação da metodologia, um sistema de identificação do processo foi desenvolvido de forma recursiva, no qual modelos de convolução e fenomenológico foram empregados como representação do modelo e processo, agrupado a um procedimento de auto sintonia, necessário para considerar os parâmetros de sintonia como variáveis aleatórias e, por conseguinte as raízes da equação característica do sistema em malha fechada.O mapeamento da região de robustez tem sido realizado a partir das raízes da equação característica, considerando a distância estatística como a métrica representativa da robustez da estabilidade a qual permite estabelecer a região com certo grau de significância.Os resultados obtidos demonstram o potencial analítico exigido pela metodologia, permitindo também a análise online, com baixo esforço computacional e operacional mostrando ser um poderoso instrumento de avaliação de sistema de controle. / This study discusses the development of a methodology based on classical concepts of statistics and probability to analyze and evaluate the robustness of the stability and performance of the control system, particularly those that use the PID as control law. To establish the conditions for the application of the methodology, a recursive system identification method process was developed, in which convolution and phenomenological models were used to represent model and process, together with a self-tuning procedure that is necessary to consider tuning parameters as random variables, and hence the roots of the characteristic equation of the closed loop system. The mapping of the region of robustness has been achieved from the roots of the characteristic equation, considering the statistical distance as the metric represented to the robustness of stability which allows the region to establish a degree of significance. The results obtained demonstrate the potential analytical and evaluation required by the methodology, allowing such analysis also "online" with low computational effort and operational proving to be a powerful tool in the analysis of control system.

A ideia de usar redes neurais biologicamente inspiradas na computação tem sido amplamente utilizada nas últimas décadas. O fato essencial neste paradigma é que um neurônio pode integrar e processar informações, e esta informação pode ser revelada por sua atividade de pulsos. Ao descrever a dinâmica de um único neurônio usando um modelo matemático, uma rede pode ser implementada utilizando um conjunto desses neurônios, onde a atividade pulsante de cada neurônio irá conter contribuições, ou informações, da atividade pulsante da rede em que está inserido. Neste trabalho é apresentado um controlador de posição no eixo Z utilizando fusão de sensores baseado no paradigma de Redes Neurais Recorrentes. O sistema proposto utiliza uma Máquina de Estado Líquido (LSM) para controlar o robô colaborativo BAXTER. O framework foi projetado para trabalhar em paralelo com as LSMs que executam trajetórias em formas fechadas de duas dimensões, com o objetivo de manter uma caneta de feltro em contato com a superfície de desenho, dados de sensores de força e distância são alimentados ao controlador. O sistema foi treinado utilizando dados de um controlador Proporcional Integral Derivativo (PID), fundindo dados de ambos sensores. Resultados mostram que a LSM foi capaz de aprender o comportamento do controlador PID em diferentes situações. / The idea of employing biologically inspired neural networks to perform computation has been widely used over the last decades. The essential fact in this paradigm is that a neuron can integrate and process information, and this information can be revealed by its spiking activity. By describing the dynamics of a single neuron using a mathematical model, a network in which the spiking activity of every single neuron will get contributions, or information, from the spiking activity of the embedded network. A positioning controller based on Spiking Neural Networks for sensor fusion suitable to run on a neuromorphic computer is presented in this work. The proposed framework uses the paradigm of reservoir computing to control the collaborative robot BAXTER. The system was designed to work in parallel with Liquid State Machines that performs trajectories in 2D closed shapes. In order to keep a felt pen touching a drawing surface, data from sensors of force and distance are fed to the controller. The system was trained using data from a Proportional Integral Derivative controller, merging the data from both sensors. The results show that the LSM can learn the behavior of a PID controller on di erent situations.

Made available in DSpace on 2014-06-11T19:27:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-11Bitstream added on 2014-06-13T18:55:43Z : No. of bitstreams: 1 guirao_phf_me_ilha.pdf: 1687835 bytes, checksum: 03fd61b5a3923d210d53985b49bab6bd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho apresenta-se uma análise teórica do desempenho de um sistema de controle ativo de vibrações de rotores utilizando mancais magnéticos. Trata-se de uma alternativa de controle ativo de vibrações de rotores onde um sistema adaptativo feedforward é empregado sobreposto ao sistema de controle feedback dos mancais magnéticos. O desempenho de algumas arquiteturas de controle, tanto em termos de vibração global como em vibração local do rotor, foi analisado dando ênfase na variação do ganho proporcional e derivativo do controlador PID, que compõe o circuito de controle do mancal magnético ativo. Também foi analisado o efeito da posição e do número de sensores de erro, bem como o efeito do mancal atuador utilizado, sobre o desempenho das estratégias de controle. O sistema de controle foi aplicado em um modelo teórico de rotor desenvolvido pelo método da matriz de impedância. / In this work a theoretical analysis of the performance of a system which actively controls vibrations of rotors using magnetic bearings is presented. The proposed system of control is an alternative of active control of rotor vibrations in which an adaptive feedforward system superimposed on the feedback control system of the magnetic bearings is used. The performance of some control architectures was analyzed, in terms of global vibration as in terms of local vibration of the rotor, giving emphasis in the variation of the proportional and derivative gain of the PID controller of the control circuit of the active magnetic bearings. Furthermore, the performance of the vibration control system was analyzed considering the effect of the number and position of the error sensors, as well as the effect of the magnetic bearing employed as actuator. The control system was applied in a theoretical rotor model developed by the matrix impedance method.