Predictive statistical modeling shows promise in accurately predicting academic performance for students enrolled in online programs. This approach has proven effective in accurately identifying students who are at-risk enabling instructors to provide instructional intervention. While the potential benefits of statistical modeling is significant, implementations have proven to be complex, costly, and difficult to maintain. To address these issues, the purpose of this study is to develop a fully integrated, automated predictive modeling system (PMS) that is flexible, easy to use, and portable to identify students who are potentially at-risk for not succeeding in a course they are currently enrolled in. Dynamic and static variables from a student system (edX) will be analyzed to predict academic performance of an individual student or entire class. The PMS model framework will include development of an open-source Web application, application programming interface (API), and SQL reporting services (SSRS). The model is based on knowledge discovery database (KDD) approach utilizing inductive logic programming language (ILP) to analyze student data. This alternative approach for predicting academic performance has several unique advantages over current predictive modeling techniques in use and is a promising new direction in educational research.

Die vorliegende Arbeit beschäftigt sich mit der analytischen Modellierung und Optimierung synthetischer Jet-Aktuatoren, welche zur aktiven Strömungsbeeinflussung genutzt werden können. Ein in der Literatur bekanntes eindimensionales Modell wird ausführlich hergeleitet und an gemessene Geschwindigkeitsspektren verschiedener Jet-Aktuatoren angepasst. Der Einfluss jedes Modellparameters wird separat untersucht. Außerdem wird ein empirischer Zusammenhang zwischen Membranresonanzfrequenz und Luftkammervolumen angegeben, mit dessen Hilfe synthetische Jet-Aktuatoren mit größtmöglichen Strömungsgeschwindigkeiten durch die Düse konstruiert werden können.

[pt] Simuladores de movimentos são sistemas mecatrônicos que reproduzem as principais atitudes e movimentos de um veículo. Neste estudo serão analisados simuladores baseados em mecanismos com 3 e 6 graus de liberdade. No segundo caso, o mecanismo é capaz de reproduzir todos os ângulos de atitude (rolagem, arfagem e guinada) e todos os deslocamentos lineares (lateral, vertical e longitudinal) com limitações, porém com amplitude suficiente de modo a possibilitar os principais movimentos associados ao veículo. O uso de transdutores de deslocamento linear nestes mecanismos articulados introduzem elevados efeitos de inércia, além de aumentar a massa dos mesmos, diminuindo sua relação carga/peso e sua eficiência. Atualmente, o grande desenvolvimento de sensores do tipo unidade de medição inercial (IMU) aumentou a disponibilidade destes no mercado e reduziu muito seu custo. Como se trata de acelerômetros triaxiais em conjunto com girômetros também triaxiais, sensores como este podem ser usados para determinar a posição e a orientação no espaço de mecanismos com seis graus de liberdade, como a Plataforma Stewart. Neste trabalho será desenvolvida uma metodologia para modelagem da cinemática de mecanismos paralelos baseada nos derivativos de suas matrizes jacobianas. Esta metodologia é avaliada em um mecanismo paralelo plano de três graus de liberdade e em uma Plataforma Stewart. Com a metodologia de modelagem validada, é implementada uma estratégia de controle baseada no uso de um sensor tipo central inercial para o controle de posição, velocidade e aceleração destes mecanismos. Os resultados das simulações indicam a possibilidade do uso destes sensores nestes tipos de equipamentos e apontam para a necessidade de avaliar esta metodologia em testes experimentais. / [en] Movement simulators are mechatronic systems that reproduce the main attitudes and movements of a vehicle. In this study are examined simulators based on 3 and 6 degrees of freedom mechanisms. In the second case, the mechanism is able to reproduce all the attitude angles (roll, pitch and yaw) and all the linear displacements (sway, heave and surge) with limitations, but with sufficient amplitude to enable the main movements associated with the vehicle. The use of linear displacement transducers in these articulated mechanisms introduce high inertia effects and increase the mass, decreasing the load/weight ratio and efficiency. Currently, the great development of the inertial central type sensors (IMU – Inertial measurement unit) increased the availability of these transducers on market and greatly reduced cost. Since this is a conjunct of triaxial accelerometers with triaxial gyrometers, sensors such as these ones can be used to determine the position and orientation in space of mechanisms with six degrees of freedom, such as the Stewart Platform. In this work it will be developed a methodology for modeling the kinematics of parallel mechanisms based on derivatives of their jacobian matrices. This methodology is evaluated in a planar parallel mechanism of three degrees of freedom and on a Stewart Platform. With the modeling methodology validated, a control strategy based on the use of an inertial unit type sensor for controlling the position, velocity and acceleration of these mechanisms is implemented. The simulations results indicate the possibility of using these sensors in these types of equipment and point to the need to evaluate this methodology in experimental tests.

L’interface entre le silicium amorphe (a-Si:H) et le silicium cristallin (c-Si) est un constituent clés de cellules solaires à haut rendement reposant sur des procédés à basse température. Trois propriétés de l’interface déterminent le rendement des cellules solaires à hétérojonction de silicium: les décalages de bandes entre a-Si:H et c-Si, les défauts d’interface et la courbure de bande dans c-Si. Ces trois aspects sont traités dans ces travaux de thèse.Dans un premier un temps, un calcul analytique de la courbure de bande dans c-Si est développé. Il repose sur l’approximation d’une densité d’état (DE) constante dans la bande interdite de a-Si:H. L’influence des principaux paramètres de la structure sur la courbure de bande est étudiée : décalage de bande, densité d’état dans a-Si:H, défaut d’interface, etc. La présence d’un effet de confinement quantique est discutée. Grâce à une comparaison entre ces calculs et des mesures de conductance planaire en fonction de la température sur des structures (p)a-Si:H/(n)c-Si et (n)a-Si:H/(p)c-Si, les décalages de bande de valence et de conduction ont pu être estimés à 0.36 eV et 0.15 eV respectivement. En outre, il est montré que le décalage de la bande de valence est indépendant de la température, alors que le décalage de la bande de conduction suit les évolutions des bandes interdites de c-Si et a-Si:H. Ces mesures tendent à prouver que le ‘branch point’ dans a-Si:H est indépendant du dopage.Ensuite, les calculs analytiques sont approfondis pour prendre en compte différents aspects de la structure complète incorporée dans les cellules : contact avec un oxyde transparent conducteur, présence d’une couche de a-Si:H non-dopée à l’interface. A l’aide de simulations numériques et à la lumière de mesures de conductance planaire conjuguées à des mesures de la qualité de passivation de l’interface, des pistes pour optimiser les cellules à hétérojonction sont commentées. En particulier, il est montré qu’un optimum doit être trouvé entre une bonne passivation et une courbure de bande suffisante. Ceci peut être accompli par un réglage fin des propriétés de la couche tampon (épaisseur, dopage), du contact (travail de sortie élevé) et de l’émetteur (p)a-Si:H (densité de défauts et épaisseur). En particulier, un émetteur avec une DE importante conduit paradoxalement à de meilleures performances.Enfin, un nouveau type d’interface a été développé. La surface de c-Si a été oxydée volontairement dans de l’eau pure dé-ionisée à 80 °C avant le dépôt de (p)a-Si:H afin d’obtenir une structure (p)a-Si:H/SiO2/(n)c-Si. A l’aide d’un modèle de courant par effet tunnel implémenté dans le logiciel de simulation numérique AFORS-HET, l’effet d’une couche à grande bande interdite (comme c’est le cas pour SiO2) sur les performances de cellules est étudié : le facteur de forme et le courant de court-circuit sont extrêmement réduits. En revanche, une couche de SiO2 n’a que peu d’impact sur les propriétés optiques de la structure. Expérimentalement, les échantillons réalisés montrent une qualité de passivation à mi-chemin entre le cas sans couche tampon et le cas avec (i)a-Si:H : ceci est expliqué par la présence d’une charge fixe négative dans l’oxyde. La courbure de bande dans c-Si est moins affectée par la présence d’une couche d’oxyde que d’une couche de (i)a-Si:H. Les cellules solaires réalisées démontrent que le concept a le potentiel d’aboutir à de hauts rendements : sur des structures non-optimisées, une tension de court-circuit supérieure à 650 mV a été démontrée, alors que l’oxyde ne semble pas limiter le transport de charge. / The interface between amorphous silicon (a-Si:H) and crystalline silicon (c-Si) is the building block of high efficiency solar cells based on low temperature fabrication processes. Three properties of the interface determine the performance of silicon heterojunction solar cells: band offsets between a-Si:H and c-Si, interface defects and band bending in c-Si. These three points are addressed in this thesis.First, an analytical model for the calculation of the band bending in c-Si is developed. It assumes a constant density of states (DOS) in the a-Si:H band gap. The influence of most parameters of the structure on the band bending is studied: band offsets, DOS in a-Si:H, interface defects, etc. The presence of quantum confinement at the interface is discussed. Analytical calculations and temperature dependent planar conductance measurements are compared such that the band offsets on both (p)a-Si:H/(n)c-Si and (n)a-Si:H/(p)c-Si can be estimated: the valence band offset amounts 0.36 eV while the conduction band offset is 0.15 eV. In addition, it is shown that the valence band offset is independent of temperature whereas the conduction band offset follows the evolutions of c-Si and a-Si:H band gaps with temperature. A discussion of these results in the frame of the branch point theory for band line-up leads to the conclusion that the branch point in a-Si:H is independent of the doping.Then, analytical calculations are developed further to take into account the real solar cell structure where the a-Si:H/c-Si structure is in contact with a transparent conductive oxide and an undoped buffer layer is present at the interface. Measurements of the planar conductance and of the interface passivation quality are interpreted in the light of analytical calculations and numerical simulations to open a way towards a method for the optimization of silicon heterojunction solar cells. It is particularly shown that a trade-off has to be found between a good passivation quality and a significant band bending. This can be realized by tuning the buffer layer properties (thickness, doping), the TCO-contact (high work function) and the emitter (defect density and thickness). Interestingly, an emitter with a high DOS leads to better cell performances.Finally, a new type of interface has been developed, that was not applied to heterojunction solar cells so far. The c-Si surface has been oxidized in deionized water at 80 °C before the (p)a-Si:H emitter deposition such that (p)a-Si:H/SiO2/(n)c-Si structures were obtained. A tunneling current model has been developed, implemented in the 1D numerical device simulator AFORS-HET and used to study the effect of a wide band gap interfacial layer (as it is the case for SiO2) on cell performance: the fill-factor and the short-circuit current are dramatically reduced for thick and high barriers. However, a SiO2 layer has only little impact on optical properties. Fabricated samples show a passivation quality halfway between samples with no buffer layer and with an (i)a-Si:H buffer layer: this is explained by the presence of a negative fixed charge in the oxide. The band bending in (n)c-Si is higher with an oxide layer than with an (i)a-Si:H buffer layer. Solar cells demonstrate that this new concept has the potential to achieve high power conversion efficiencies: for non-optimized structures, an open-circuit voltage higher than 650 mV has been demonstrated, while the oxide does not seem to create a barrier to charge transport.

La thèse se base sur la recherche des possibilités de caractérisation du son aérien de sources sonores arbitraires. A cette fin, une approche particulière est étudiée à l’endroit où la caractérisation de la source est faite via une surface d’interface qui enveloppe totalement ou partiellement la source physique. Deux descripteurs qui dépendent de la fréquence sont definis au travers d’une telle surface: la pression sonore bloquée et l’impédance de la source. Le précédent représente la pression sonore créée par le système d’exploitation source qui agit sur la surface enveloppante quand elle est rendue immobile. Cette dernière représente le rapport des amplitudes de réponse de pression et les amplitudes de vitesse d’excitation normales au travers de la surface. La surface enveloppante définit un volume d’air qui contient la source physique appelée l’espace source. Les deux descripteurs définis sur l’espace source, la pression bloquée et l’impédance de la source sont montrés comme étant intrinsèques à la source, c’est-à-dire indépendants de l’espace acoustique environnant. Une fois définis, ces descripteurs permettent de trouver la pression sonore et la vitesse particulaire normale à la surface de l’interface quand l’espace source est couplé à un espace récepteur arbitraire, c’est-à-dire une pièce. Cela permet alors la prédiction du son dans l’espace récepteur. Les conditions de couplage nécessitent que l’espace récepteur soit caractérisé en utilisant la même surface enveloppante telle que l’espace source. En acceptant de garder à l’esprit la simplicité de la mesure, la surface enveloppante a été conçue vu qu’elle comporte une ou plusieurs surfaces rectangulaires planes. Le défi de la recherche était alors d’obtenir une impédance significative de la surface au travers de la surface plane rectangulaire (continue) ainsi que celle de la pression bloquée compatible avec la formulation de l’impédance. Cela a conduit à une décomposition dans l’espace de la pression sonore et de la vitesse des particules au sein du nombre fini des composants, chacun défini par une amplitude complexe et une distribution dans l’espace particulière. De cette façon, la pression bloquée se réduit à un vecteur d’amplitude de pression complexe, tandis que l’impédance devient une matrice de pression et des rapports d’amplitudes complexes de la vitesse de défauts de de décompositions ont été recherchés dans le détail: la méthode harmonique de surface et la méthode du patch. Le premier se rapproche de la pression de surface et de la vitesse normale par des combinaisons de fonctions de surface trigonométriques en 2D tandis que ce dernier partage la surface en petites parcelles et intervient sur chaque parcelle de façon discrète en utilisant les valeurs moyennes du patch. / The thesis investigates possibilities of air-borne sound characterisation of arbitrary sound sources. To this end a particular approach is studied where the source characterisation is done via an interface surface which fully or partially envelopes the physical source. Two frequency dependent descriptors are defined across such a surface: the blocked sound pressure and the source impedance. The former represents the sound pressure created by the operating source which acts on the enveloping surface when this is made immobile. The latter represents the ratio of pressure response amplitudes and normal velocity excitation amplitudes across the surface. The enveloping surface defines an air volume containing the physical source, called the source space. The two source descriptors defined on the source space, the blocked pressure and the source impedance, are shown to be intrinsic to the source, i.e. independent of the surrounding acoustical space. Once defined, these descriptors allow one to find the sound pressure and normal particle velocity at the interface surface when the source space is coupled to an arbitrary receiver space, i.e. a room. This in turn allows for sound prediction in the receiver space. The coupling conditions require that the receiver space is characterised using the same enveloping surface as the source space. Bearing the measurement simplicity in mind, the enveloping surface has been conceived as consisting of one or several rectangular plane surfaces. The research challenge was then to obtain meaningful surface impedance across a (continuous) rectangular plane surface as well as the blocked pressure compatible with impedance formulation. This has led to a spatial decomposition of sound pressure and particle velocity into finite number of components, each defined by a complex amplitude and a particular spatial distribution. In this way the blocked pressure reduces to a vector of complex pressure amplitudes while the impedance becomes a matrix of pressure and velocity complex amplitude ratios. Two decomposition methods have been investigated in detail: the surface harmonic method and the patch method. The former approximates the surface pressure and normal velocity by combinations of 2D trigonometric surface functions while the latter splits the surface into small patches and treats each patch in a discrete way, using patch-averaged values.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Este trabalho apresenta as características básicas de uma máquina elétrica com fluxo axial, ímãs permanentes, rotor duplo e estator com enrolamentos toroidais montado entre os rotores. A máquina foi construída no Laboratório de Máquinas Elétricas, Acionamentos e Energia da Escola de Engenharia da UFRGS. O trabalho contém modelos analíticos para as induções magnéticas dos ímãs permanentes e dos enrolamentos de armadura. A partir dos modelos foram desenvolvidas expressões para o cálculo de forças eletromotrizes e de conjugados, sendo utilizado um software de matemática simbólica para realização dos cálculos. É apresentada uma comparação entre os resultados obtidos através do modelo analítico e os resultados obtidos por simulação numérica. Alguns resultados são comparados também com valores experimentais. As expressões para o cálculo de conjugado desenvolvido pela máquina serão detalhadas em uma etapa posterior. Foi obtida uma razoável coerência entre os dados comparados. / This work presents the basic features of an axial flux, permanent magnet, double rotor and toroidal windings mounted between the rotors. The machine was built in the Laboratory of Electrical Machines, Drives and energy of the School of Engineering of the Federal University of Rio Grande do Sul. The work contains analytical models of permanent magnets and armature windings magnetic inductions. Based in models, expressions of electromotive forces and torques were derived. The calculations were performed with a symbolical mathematical software. It is presented a comparison between results obtained with analytical model and results of the numerical simulation. Some comparisons include experimental results. The expressions of machine torque will be detailed in a next phase. The compared results present an acceptable conformity.

Les principaux objectifs de la thèse sont de proposer des modèles dynamiques pour décrire la circulation routière en adaptant des modèles de la mécanique des fluides et à partir de ces modèles de concevoir et mettre en œuvre des algorithmes de contrôle. La circulation routière est considérée comme un système complexe organisé dans une structure décentralisée à trois niveaux: au plus haut niveau il y a le réseau routier, décomposé, au niveau suivant, en objets routiers (tronçons et intersections), aussi décomposés, au dernier niveau, en éléments (segments) routiers.La thèse est organisée en six chapitres. Le premier chapitre présente les problèmes spécifiques aux réseaux de circulation routière, ainsi que des modèles et des algorithmes de contrôle trouvés dans la littérature. Le deuxième chapitre présente les principaux outils nécessaires pour décrire un modèle de trafic macroscopique et des façons pour représenter le flux de véhicules. Dans le troisième chapitre, des modèles dynamiques sont proposés pour différents segments et tronçons routiers. Le quatrième chapitre est consacré à la conception d’algorithmes pour le contrôle du trafic et l’optimisation de la circulation, y compris une analyse de robustesse pour évaluer la tolérance du système aux non-linéarités du modèle. Le cinquième chapitre présente une stratégie de contrôle pour le réseau routier, en utilisant la représentation par des modèles à compartiments et le concept de dynamique positive. Dans le dernier chapitre de la thèse, les contributions de l’auteur sont mises en évidence et quelques perspectives pour le développement ultérieur de la recherche sont présentées / The main objectives of this thesis are to propose dynamic models in order to describe road traffic by adapting models of fluid mechanics and based on these models to design and implement control algorithms. Road traffic is seen as a complex system organized in a decentralized structure. At the highest level of complexity there is the traffic network, considered as a part of a city’s road infrastructure. At the next level, the network is decomposed into traffic objects represented by road sections (streets) and intersections. At the last level of complexity there are the road segments that are parts of a road section.The thesis is organized into six chapters. The first chapter presents specific problems of road traffic networks, as well as control models and algorithms found in literature. The second chapter presents the main tools needed to describe a macroscopic traffic model, and some ways of representing the flow of vehicles. In the third chapter, dynamic models are proposed for different road segments and sections. The fourth chapter is devoted to designing algorithms for traffic control and optimization, including a robustness analysis to evaluate the system’s tolerance to model nonlinearities. The fifth chapter presents a control strategy for the road network, using the representation with compartmental models and the concept of positive dynamic. In the last chapter of the thesis, the author’s contributions are highlighted and some perspectives for further development of the research are presented

This work develops an exact logical operation model to predict the performance of the all-optical shared-memory architecture (OSMA) class of packet switches and provides a means to obtain a reasonable approximation of OSMA switch performance within certain types of networks, including the Banyan family. All-optical packet switches have the potential to far exceed the bandwidth capability of their current electronic counterparts. However, all-optical switching technology is currently not mature. Consequently, all-optical switch fabrics and buffers are more constrained in size and can cost several orders of magnitude more than those of electronic switches. The use of shared-memory buffers and/or links with multiple parallel channels (channel grouping) have been suggested as ways to maximize switch performance with buffers of limited size. However, analysis of shared-memory switches is far more difficult than for other commonly used buffering strategies. Obtaining packet loss performance by simulation is often not a viable alternative to modeling if low loss rates or large networks are encountered. Published models of electronic shared-memory packet switches (ESMP) have primarily involved approximate models to allow analysis of switches with a large number of ports and/or buffer cells. Because most ESMP models become inaccurate for small switches, and OSMA switches, unlike ESMP switches, do not buffer packets unless contention occurs, existing ESMP models cannot be applied to OSMA switches. Previous models of OSMA switches were confined to isolated (non-networked), symmetric OSMA switches using channel grouping under random traffic. This work is far more general in that it also encompasses OSMA switches that (1) are subjected to bursty traffic and/or with input links that have arbitrary occupancy probability distributions, (2) are interconnected to form a network and (3) are asymmetric.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.