Apesar do esforço despendido pelas comunidades acadêmica e industrial (artigos, patentes e protótipos de laboratório), as Máquinas de Cinemática Paralela - MCPs - ainda apresentam uma participação inexpressiva no mercado de máquinasferramentas e robôs. Uma das razões para este fato são os seus baixos índices de acurácia e repetibilidade, em comparação aos das máquinas de usinagem convencionais. Este trabalho apresenta a avaliação dos mapeamentos de flexibilidade e da 1ª freqüência natural sobre o posicionamento da peça de trabalho e direções preferenciais de usinagem, dentro do espaço de trabalho disponível de uma máquina-ferramenta de cinemática paralela. Atualmente esta análise tem sido realizada em máquinas de cinemática paralela utilizando-se do princípio dos trabalhos virtuais ou parcialmente envolvendo este método e o método dos elementos finitos com a superposição linear dos resultados de ambos. Este trabalho apresenta análise de flexibilidade, utilizando apenas o método dos elementos finitos, aplicada a uma arquitetura paralela do tipo 2PRS+2PUS, com 4 graus de liberdade (duas translações - Y e Z - e duas rotações - \'teta\'x e \'teta\'YG), denominada Tetraglide. Em todas as análises feitas o grau de liberdade \'teta\'YG foi mantido constante, \'teta\'YG = 0°. Desta forma todas as análises ocorreram sobre o plano YZ. A partir dessa análise de flexibilidade são avaliadas as cargas axiais nas barras, que unem os atuadores à plataforma móvel ao longo do espaço de trabalho, determinando-se onde ocorre flambagem. Após isto, ainda com o método dos elementos finitos, obtém-se a 1ª freqüência natural ao longo de cada espaço de trabalho com orientação constante, uma vez que o conhecimento desta freqüência é fator importante na avaliação do comportamento estrutural dinâmico de máquinas-ferramentas. Após estas análises, analisam-se parâmetros estruturais em análises de sensibilidade visando maximizar a menor 1ª freqüência natural observada em cada espaço de trabalho com orientação constante. / In spite of the effort spent by the academic and industrial communities (goods, patents and laboratory prototypes), the Parallel Kinematics Machines - PKMs - they still present an inexpressive participation in the market of machine-tools and robots. One of the reasons for this fact is their low indexes of accuracy and precision, in comparison with the machines of conventional milling. This work presents the evaluation of the compliance mapping (kinetostatic analysis) and natural frequency about the positioning of the work piece and milling preferential directions, inside the available workspace of a parallel kinematics machine tool. At present this analysis has been accomplished in parallel kinematics machine using the virtual work principle or partially involving this method and the finite element method, with the overlap of the results of both. This work presents a compliance analysis just using the finite element method in parallel kinematics machine of type 2PRS+2PUS with 4 degrees of freedom (two moves - Y and Z - and two rotations - \'teta\'x e \'teta\'YG), denominated Tetraglide. In all of the done analyses the degree of freedom \'teta\'YG was maintained constant, \'teta\'YG = 0°. This way all of the analyses occurred on the plan YZ. Starting from the compliance analysis the axial loads are evaluated in the bars, which connect the actuators to the movable platform along the workspace, determining where the buckling occurs. After this, with the finite element method, 1st natural frequency is obtained along each constant-orientation workspace, once the knowledge of this frequency is important factor in the evaluation of the dynamic structural behavior of machine-tools. After these analyses, structural parameters are analyzed in sensibility analyses seeking to maximize to smallest 1st natural frequency observed in each constant-orientation workspace.

Apesar do esforço despendido pelas comunidades acadêmica e industrial (artigos, patentes e protótipos de laboratório), as Máquinas de Cinemática Paralela - MCPs - ainda apresentam uma participação inexpressiva no mercado de máquinasferramentas e robôs. Uma das razões para este fato são os seus baixos índices de acurácia e repetibilidade, em comparação aos das máquinas de usinagem convencionais. Este trabalho apresenta a avaliação dos mapeamentos de flexibilidade e da 1ª freqüência natural sobre o posicionamento da peça de trabalho e direções preferenciais de usinagem, dentro do espaço de trabalho disponível de uma máquina-ferramenta de cinemática paralela. Atualmente esta análise tem sido realizada em máquinas de cinemática paralela utilizando-se do princípio dos trabalhos virtuais ou parcialmente envolvendo este método e o método dos elementos finitos com a superposição linear dos resultados de ambos. Este trabalho apresenta análise de flexibilidade, utilizando apenas o método dos elementos finitos, aplicada a uma arquitetura paralela do tipo 2PRS+2PUS, com 4 graus de liberdade (duas translações - Y e Z - e duas rotações - \'teta\'x e \'teta\'YG), denominada Tetraglide. Em todas as análises feitas o grau de liberdade \'teta\'YG foi mantido constante, \'teta\'YG = 0°. Desta forma todas as análises ocorreram sobre o plano YZ. A partir dessa análise de flexibilidade são avaliadas as cargas axiais nas barras, que unem os atuadores à plataforma móvel ao longo do espaço de trabalho, determinando-se onde ocorre flambagem. Após isto, ainda com o método dos elementos finitos, obtém-se a 1ª freqüência natural ao longo de cada espaço de trabalho com orientação constante, uma vez que o conhecimento desta freqüência é fator importante na avaliação do comportamento estrutural dinâmico de máquinas-ferramentas. Após estas análises, analisam-se parâmetros estruturais em análises de sensibilidade visando maximizar a menor 1ª freqüência natural observada em cada espaço de trabalho com orientação constante. / In spite of the effort spent by the academic and industrial communities (goods, patents and laboratory prototypes), the Parallel Kinematics Machines - PKMs - they still present an inexpressive participation in the market of machine-tools and robots. One of the reasons for this fact is their low indexes of accuracy and precision, in comparison with the machines of conventional milling. This work presents the evaluation of the compliance mapping (kinetostatic analysis) and natural frequency about the positioning of the work piece and milling preferential directions, inside the available workspace of a parallel kinematics machine tool. At present this analysis has been accomplished in parallel kinematics machine using the virtual work principle or partially involving this method and the finite element method, with the overlap of the results of both. This work presents a compliance analysis just using the finite element method in parallel kinematics machine of type 2PRS+2PUS with 4 degrees of freedom (two moves - Y and Z - and two rotations - \'teta\'x e \'teta\'YG), denominated Tetraglide. In all of the done analyses the degree of freedom \'teta\'YG was maintained constant, \'teta\'YG = 0°. This way all of the analyses occurred on the plan YZ. Starting from the compliance analysis the axial loads are evaluated in the bars, which connect the actuators to the movable platform along the workspace, determining where the buckling occurs. After this, with the finite element method, 1st natural frequency is obtained along each constant-orientation workspace, once the knowledge of this frequency is important factor in the evaluation of the dynamic structural behavior of machine-tools. After these analyses, structural parameters are analyzed in sensibility analyses seeking to maximize to smallest 1st natural frequency observed in each constant-orientation workspace.

Indoor Positioning Systems (IPS) using the existing WLAN have won growing interest in the last years, it can be a perfect supplement to provide location information of users in indoor environments where other positioning techniques such as GPS, are not much effective. The thesis manuscript proposes a new approach to define a WLAN-based indoor positioning system (WLAN-IPS) as a combinatorial optimization problem to guarantee the requested communication quality while optimizing the positioning error. This approach is characterised by several difficult issues we tackled in three steps.At first, we designed a WLAN-IPS and implemented it as a test framework. Using this framework, we looked at the system performance under various experimental constraints. Through these experiments, we went as far as possible in analysing the relationships between the positioning error and the external environmental factors. These relationships were considered as evaluation indicators of the positioning error. Secondly, we proposed a model that defines all major parameters met in the WLAN-IPS from the literature. As the original purpose of the WLAN infrastructures is to provide radio communication access, we introduced an additional purpose which is to minimize the location error within IPS context. Two main indicators were defined in order to evaluate the network Quality of Service (QoS) and the positioning error for Location-Based Service (LBS). Thirdly, after defining the mathematical formulation of the optimisation problem and the key performance indicators, we proposed a mono-objective algorithm and a multi-objective algorithm which are based on Tabu Search metaheuristic to provide good solutions within a reasonable amount of time. The simulations demonstrate that these two algorithms are highly efficient for the indoor positioning optimization problem.

La localisation des personnes et des objets à l’intérieur des bâtiments basée sur les réseaux WLAN connaît un intérêt croissant depuis quelques années ; ce système peut être un parfait complément pour fournir des informations de localisation statique ou dynamique dans des environnements où les techniques de positionnement telles que GPS ne sont pas efficaces. Le manuscrit de thèse propose une nouvelle approche pour définir un système WLAN de positionnement indoor (WLAN-IPS) comme un problème d'optimisation combinatoire afin de garantir à la fois une qualité de communication et une minimisation de l'erreur de positionnement via le réseau. Cette approche est caractérisée par plusieurs questions difficiles que nous abordons en trois étapes.Dans un premier temps, nous avons conçu un réseau WLAN-IPS et mis en œuvre une plateforme de test. Nous avons examiné la performance du système sous diverses contraintes expérimentales et nous nous sommes penchés sur l'analyse des relations entre l'erreur de positionnement et les facteurs environnementaux externes. Ces relations ont permis de proposer des indicateurs pour évaluer l'erreur de positionnement. Ensuite nous avons proposé un modèle physique qui définit tous les paramètres majeurs rencontrés en WLAN-IPS à partir de la littérature. L'objectif initial des infrastructures WLAN étant de fournir un accès radio de qualité au réseau, nous avons introduit un objectif supplémentaire qui est de minimiser l'erreur de localisation dans le contexte IPS. Deux indicateurs principaux ont été définis afin d'évaluer la qualité de service (QoS) et l'erreur de localisation pour LBS (Location-Based Services). Enfin après avoir défini la formulation mathématique du problème d'optimisation et les indicateurs clés de performance, nous avons proposé un algorithme mono-objectif et un algorithme multicritère basés sur Tabu Search et Variable Neighborhood Search pour fournir des bonnes solutions en temps raisonnable. Les simulations montrent que ces deux algorithmes sont très efficaces pour le problème d'optimisation que nous avons posé. / Indoor Positioning Systems (IPS) using the existing WLAN have won growing interest in the last years, it can be a perfect supplement to provide location information of users in indoor environments where other positioning techniques such as GPS, are not much effective. The thesis manuscript proposes a new approach to define a WLAN-based indoor positioning system (WLAN-IPS) as a combinatorial optimization problem to guarantee the requested communication quality while optimizing the positioning error. This approach is characterised by several difficult issues we tackled in three steps.At first, we designed a WLAN-IPS and implemented it as a test framework. Using this framework, we looked at the system performance under various experimental constraints. Through these experiments, we went as far as possible in analysing the relationships between the positioning error and the external environmental factors. These relationships were considered as evaluation indicators of the positioning error. Secondly, we proposed a model that defines all major parameters met in the WLAN-IPS from the literature. As the original purpose of the WLAN infrastructures is to provide radio communication access, we introduced an additional purpose which is to minimize the location error within IPS context. Two main indicators were defined in order to evaluate the network Quality of Service (QoS) and the positioning error for Location-Based Service (LBS). Thirdly, after defining the mathematical formulation of the optimisation problem and the key performance indicators, we proposed a mono-objective algorithm and a multi-objective algorithm which are based on Tabu Search metaheuristic to provide good solutions within a reasonable amount of time. The simulations demonstrate that these two algorithms are highly efficient for the indoor positioning optimization problem.

In Intelligent Transport Systems (ITS), specifically in autonomous driving operations, accurate vehicle localization is essential for safe operations. The localization accuracy depends on both position and positioning error estimates. Technologies aiming to improve positioning error estimation are required and are currently being researched. This project has investigated machine learning algorithms applied to positioning error estimation by assessing relevant information obtained from a GNSS receiver and adding environmental information  coming from a camera mounted on a radio controlled vehicle testing platform. The research was done in two stages. The first stage consists of the machine learning algorithms training and testing on existing GNSS data coming from Waysure´s data base from tests ran in 2016, which did not consider the environment surrounding the GNSS receiver used during the tests. The second stage consists of the machine learning algorithms training and testing on GNSS data coming from new test runs carried on May 2019, which include the environment surrounding the GNSS receiver used. The results of both stages are compared. The relevant features are obtained as a result of the machine learning decision trees algorithm and are presented. This report concludes that there is no statistical evidence indicating that the tested environmental input from the camera could improve positioning error estimation accuracy with the built machine learning models. / Inom Intelligenta transportsystem (ITS), specifikt för självkörande fordon, så är en exakt fordonspositionering en nödvändighet för ökad trafiksäkerhet. Positionsnoggrannheten beror på estimering av både positionen samt positionsfelet. Olika tekniker och tillämpningar som siktar på att förbättra positionsfeluppskattningen behövs, vilket det nu forskas kring. Denna uppsats undersöker olika maskininlärningsalgoritmer inriktade på estimering av positionsfel. Algoritmerna utvärderar relevant information från en GNSS-mottagare, samt information från en kamera om den kringliggande miljön. En GNSS-mottagare och kamera monterades på en radiostyrd mobil testplattform för insamling av data.  Examensarbetet består av två delar. Första delen innehåller träning och testning av valda maskininlärningsalgoritmer med GNSS-data tillhandahållen av Waysure från tester gjorda under 2016. Denna data inkluderar ingen information från den omkringliggande miljön runt GNSS-mottagaren. Andra delen består av träning och testning av valda maskininlärningsalgoritmer på GNSS-data som kommer från nya tester gjorda under maj 2019, vilka inkluderar miljöinformation runt GNSS-mottagaren. Resultaten från båda delar analyseras. De viktigaste egenskaper som erhålls från en trädbaserad modell, algoritmens beslutsträd, presenteras. Slutsatsen från denna rapport är att det inte går att statistiskt säkerställa att inkludering av information från den omkringliggande miljön från en kamera förbättrar noggrannheten vid estimering av positionsfelet med de valda maskininlärningsmodellerna.