O presente trabalho tem por objetivo a implementação de algoritmos de controle do tipo PID com sintonia automática de seus parâmetros para controle de processos térmicos de primeira ordem mais tempo morto. Existe um grande número de métodos para a sintonia automática, os quais requerem informações variadas sobre o processo. A sintonia automática dos parâmetros do controlador escolhida para implementação é baseada no método da realimentação a relê que utiliza o ganho estático e o período e amplitude críticos do processo e pode ser facilmente adotada na indústria. Este método foi implementado em um controlador industrial microprocessado que utiliza um microcontrolador da família 8051. A correta identificação dos parâmetros críticos do processo presume a geração de oscilações simétricas durante a realimentação a relê. O algoritmo de sintonia automática desenvolvido inclui correção em tempo real da amplitude do relê para evitar identificação falsa de um ciclo da oscilação e da assimetria na saída do processo durante a realimentação a relê. A implementação do algoritmo é simples e direta em termos de programação no ambiente de microcontroladores mesmo em linguagem de baixo nível (assembly). São apresentados resultados de simulação e os resultados experimentais realizados em um aparelho industrial comercial. / The objective of this work is the implementation of a PID control algorithm with auto-tuning for a thermal first order process plus dead-time. There is a number of methods for the auto-tuning of PID controllers which require different information on the process. The auto-tuning algorithm is implemented in a industrial controller based on the 8051 microcontroller family. The auto-tuning method considered for implementation is based on the relay feedback procedure which require the process steady state gain and the ultimate point on the Nyquist plot and can be easily adopted by industry. The method is also suited for pre-tuning adaptive controllers. The auto-tuning method used assume symmetrical oscillations during the relay feedback experiment to render the correct ultimate point on the Nyquist plot The proposed auto-tuning algorithm includes on-line correction for asymmetry oscillation and relay amplitude to avoid false capture of the limit cycle. The symmetrical oscillations are ensured by a DC bias signal added to the relay output. The algorithm is simply and straight to be written in a microcontroller programming language. Experimental results accomplished in a industrial PID auto-tuner are presented.

L’utilisation d’antennes miniatures à haute sensibilité basées sur le principe des lignes de transmission a permis, lors de l’étude de pathologies chez l’Homme ou le petit animal , une amélioration significative de la qualité des images obtenues en micro Imagerie par Résonance Magnétique (IRM). Les performances élevées de ces antennes et leurs dimensions réduites entrainent cependant des difficultés critiques pour traiter et conditionner le signal de Résonance Magnétique Nucléaire (RMN) détecté. Plus particulièrement, le réajustement de la fréquence de résonance de l’antenne de détection, au cours d’une expérience d’IRM, ne peut être réalisé à l’aide de composants rapportés, comme c’est le cas avec les antennes d’IRM conventionnelles, ceci afin de ne pas dégrader leurs performances.Notre étude a consisté à développer deux techniques d’accord originales et dédiées aux antennes miniatures à lignes de transmission. Ces techniques sont basées sur le déplacement micrométrique d’un élément d’accord à proximité de l’antenne entrainant une variation de l’environnement électromagnétique de celle-ci, et donc de la fréquence de résonance, par couplage (diélectrique ou inductif). L’ensemble des résultats obtenus (par des caractérisations expérimentales, des simulations numériques et des modélisations analytiques) a servi de base à la conception et la réalisation d’un dispositif de micro-déplacement chargé d’assurer le réglage fin de la fréquence de résonance à travers le déplacement de l’élément d’accord.La mise en œuvre d’une antenne accordée à l’aide du dispositif a été réalisée au sein d’un imageur à 4,7 T. Des images de démonstration sur fantôme ont été obtenues et validées, montrant ainsi la pertinence d’un tel dispositif et la faisabilité de systèmes résonants auto-accordés dédiés à l’IRM haute sensibilité. / The use of miniature transmission lines coils, in the study of diseases in humans or small animals, has allowed for significant improvements in Micro Magnetic Resonance Imaging (MRI). The high sensitivity of such coils combined with their small size, however, leads to critical problems in treating and conditioning the detected Nuclear Magnetic Resonance (NMR) signal. In particular, the adjustment of the resonant frequency of these detection coils, during a MRI experiment, cannot be achieved using reported components, as is the case of conventional MRI coils, in order not to degrade their performances.We have developed two original tuning techniques for such coils. These techniques are based on the micrometric displacement of a tuning element near the coil surface, which modifies the electromagnetic environment of the coil by coupling, resulting in a change of the resonant frequency. The obtained results have enabled the design and construction of a micro-displacement device responsible for the fine tuning of the coil, through the displacement of a tuning element.The tuned coil and micro-device have been implemented in a 4.7 T MRI. Sample images were obtained and validated, showing the relevance and feasibility of using an auto-tuning resonant system, dedicated to high sensitivity MRI.

Made available in DSpace on 2017-07-10T19:24:05Z (GMT). No. of bitstreams: 1 Marcelo Alan Primo.pdf: 3445063 bytes, checksum: 29c3b04fea727923f8cfb2b19dba08d7 (MD5) Previous issue date: 2007-07-06 / The uniformity of the application in the soil of fertilizers is an important factor in the efficiency of use of the fertilizers and his effect stop plants. The distributors of fertilizers to I throw demand her some basic tunings in what concerns to the flow and work width. The rehearsals of work width and distribution uniformity are of difficult execution for the farmer for they demand equipments, resources and complex methods. Therefore, this work had as objective evaluates alternative collectors to turn more accessible the tuning and evaluation of distributors of fertilizers solid her throw. The work was accomplished in the Agrarian Foundation of Agricultural Research - FAPA, located in the district of Among Rivers, municipal district of Guarapuava - Paraná. Four different groups of collectors were used: i) Collectors built according to the norm ISO 5690/1; ii) Collectors of polyethylene (plastic trays) with soubrette to avoid the material rebound; iii) Collectors formed by boxes of milk long life; iv) Collectors formed by vases of polyethylene (Number 3,5). To the evaluation of the strip of traverse distribution, the collectors were distributed side by side parallel amongst themselves, forming a traverse line to the displacement of the tractor and distributor. A tractor was used Ford, model 7630, in which distributors were coupled: Jan, model Lancer Master 1200; Incomagri, model Sembra 1300-P AH; and Nogueira, model Rota Flow. The alternative collectors presented a larger retention than the established collectors. This relative difference among the collections was larger in the extremities of the distribution profile. The width executes of work obtained for the coefficients of variation of 12,5, 15, 17,5 and 20% varied among the collectors in the different courses. The collector that more it resembled each other the norm were the vases of polyethylene. It was observed that the height of the collectors went more important for his/her efficiency of what his/her collection area. / A uniformidade da aplicação no solo de fertilizantes é um importante fator na eficiência de uso dos fertilizantes e seu efeito para as plantas. Os distribuidores de fertilizantes a lanço exigem algumas regulagens básicas no que concerne à vazão e largura de trabalho. Os ensaios de largura de trabalho e uniformidade de distribuição são de difícil execução para o agricultor por exigirem equipamentos, recursos e métodos complexos. Portanto, este trabalho teve como objetivo avaliar coletores alternativos para tornar mais acessível a regulagem e avaliação de distribuidores de fertilizantes sólidos a lanço. O trabalho foi realizado na Fundação Agrária de Pesquisa Agropecuária FAPA, localizada no distrito de Entre Rios, município de Guarapuava - Paraná. Foram utilizados quatro diferentes conjuntos de coletores: i) Coletores construídos segundo a norma ISO 5690/1; ii) Coletores de polietileno (bandejas plásticas) com sombrite para evitar o ricochete de material; iii) Coletores formados por caixas de leite longa vida; iv) Coletores formados por vasos de polietileno (Número 3,5). Para a avaliação da faixa de distribuição transversal, os coletores foram distribuídos lado a lado paralelos entre si, formando uma linha transversal ao deslocamento do trator e distribuidor. Foi utilizado um trator Ford, modelo 7630, no qual foram acoplados distribuidores: Jan, modelo Lancer Master 1200; Incomagri, modelo Sembra 1300-P AH; e Nogueira, modelo Rota Flow. Os coletores alternativos apresentaram uma retenção maior que os coletores normatizados. Esta diferença relativa entre as coletas foi maior nas extremidades do perfil de distribuição. A largura efetiva de trabalho obtida para os coeficientes de variação de 12,5, 15, 17,5 e 20% variou entre os coletores nos diferentes percursos. O coletor que mais se assemelhou a norma foram os vasos de polietileno. Observou-se que a altura dos coletores foi mais importante para sua eficiência do que a sua área de coleta.

Made available in DSpace on 2017-05-12T14:47:21Z (GMT). No. of bitstreams: 1 Marcelo Alan Primo.pdf: 3445063 bytes, checksum: 29c3b04fea727923f8cfb2b19dba08d7 (MD5) Previous issue date: 2007-07-06 / The uniformity of the application in the soil of fertilizers is an important factor in the efficiency of use of the fertilizers and his effect stop plants. The distributors of fertilizers to I throw demand her some basic tunings in what concerns to the flow and work width. The rehearsals of work width and distribution uniformity are of difficult execution for the farmer for they demand equipments, resources and complex methods. Therefore, this work had as objective evaluates alternative collectors to turn more accessible the tuning and evaluation of distributors of fertilizers solid her throw. The work was accomplished in the Agrarian Foundation of Agricultural Research - FAPA, located in the district of Among Rivers, municipal district of Guarapuava - Paraná. Four different groups of collectors were used: i) Collectors built according to the norm ISO 5690/1; ii) Collectors of polyethylene (plastic trays) with soubrette to avoid the material rebound; iii) Collectors formed by boxes of milk long life; iv) Collectors formed by vases of polyethylene (Number 3,5). To the evaluation of the strip of traverse distribution, the collectors were distributed side by side parallel amongst themselves, forming a traverse line to the displacement of the tractor and distributor. A tractor was used Ford, model 7630, in which distributors were coupled: Jan, model Lancer Master 1200; Incomagri, model Sembra 1300-P AH; and Nogueira, model Rota Flow. The alternative collectors presented a larger retention than the established collectors. This relative difference among the collections was larger in the extremities of the distribution profile. The width executes of work obtained for the coefficients of variation of 12,5, 15, 17,5 and 20% varied among the collectors in the different courses. The collector that more it resembled each other the norm were the vases of polyethylene. It was observed that the height of the collectors went more important for his/her efficiency of what his/her collection area. / A uniformidade da aplicação no solo de fertilizantes é um importante fator na eficiência de uso dos fertilizantes e seu efeito para as plantas. Os distribuidores de fertilizantes a lanço exigem algumas regulagens básicas no que concerne à vazão e largura de trabalho. Os ensaios de largura de trabalho e uniformidade de distribuição são de difícil execução para o agricultor por exigirem equipamentos, recursos e métodos complexos. Portanto, este trabalho teve como objetivo avaliar coletores alternativos para tornar mais acessível a regulagem e avaliação de distribuidores de fertilizantes sólidos a lanço. O trabalho foi realizado na Fundação Agrária de Pesquisa Agropecuária FAPA, localizada no distrito de Entre Rios, município de Guarapuava - Paraná. Foram utilizados quatro diferentes conjuntos de coletores: i) Coletores construídos segundo a norma ISO 5690/1; ii) Coletores de polietileno (bandejas plásticas) com sombrite para evitar o ricochete de material; iii) Coletores formados por caixas de leite longa vida; iv) Coletores formados por vasos de polietileno (Número 3,5). Para a avaliação da faixa de distribuição transversal, os coletores foram distribuídos lado a lado paralelos entre si, formando uma linha transversal ao deslocamento do trator e distribuidor. Foi utilizado um trator Ford, modelo 7630, no qual foram acoplados distribuidores: Jan, modelo Lancer Master 1200; Incomagri, modelo Sembra 1300-P AH; e Nogueira, modelo Rota Flow. Os coletores alternativos apresentaram uma retenção maior que os coletores normatizados. Esta diferença relativa entre as coletas foi maior nas extremidades do perfil de distribuição. A largura efetiva de trabalho obtida para os coeficientes de variação de 12,5, 15, 17,5 e 20% variou entre os coletores nos diferentes percursos. O coletor que mais se assemelhou a norma foram os vasos de polietileno. Observou-se que a altura dos coletores foi mais importante para sua eficiência do que a sua área de coleta.

I April 2018 an experiment was conducted at the university of Bergen in collaboration with Novelda using the XeThru range-doppler radar. The goal of the experiment was to record data on rats using XeThru radar and by using traditional medical sensors, to see if a XeThru radar can be used instead of the traditional sensors. The data from the experiment consisted of data saved as EDF (European Data Format) from the traditional sensors, radar data and video. The rest goal of this thesis was to analyze the different data types. Then to look at the radar data with the goal of seeing if respiration detection on rats was possible and try to create a radar pro le for use on rats. This report focuses on only one of the rats from the experiment, because this rat was recorded using a video camera. In a preliminary project a python program had been written to use on the EDF data. The program was expanded upon in this thesis to optimize the performance. The python program took the EDF data and extracted the desired signal, data from a muscle sensor, and plotted it, making it possible to analyze. For the radar data Matlab was used, since Novelda already had the tools to process the data using that program. This worked using parameter les to set all the necessary settings to do a playback and change the radar and processing settings. The work then consisted of changing the parameters to get the best results on the data from the rats. A parameter le was created for use on rats that was based on the parameter le for respiration detection on adult humans. The conclusion on the EDF data was that it was not possible to nd a pattern for respiration using the muscle sensor. The radar data fortunately yielded better results. After much testing and optimization it was possible to get good respiration detection on rat 7. Some of the e ndings was possible noise problems and sources. The radar was mounted to the rack holding the cages. This meant it was susceptible to vibration noise form the other rats in the same rack and to the construction work being done at the university. Another problem with mounting of the radar was that is was to close to the cage, because the rat slept close to the wall of the cage closest to the radar. Then the problem of directly coupled energy interfered with the actual signal form the radar. It is still unclear if a radar sensor can replace the traditional sensors, but it is very possible to detect respiration on rats. With some more work, and possible a new experiment xing the noise sources, can make it possible.

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A large body of literature exists regarding linear and nonlinear dynamic absorbers, but the vast majority of it deals with linear primary structures. However, nonlinearity is a frequency occurrence in engineering applications. Therefore, the present thesis focuses on the mitigation of vibrations of nonlinear primary systems using nonlinear dynamic absorbers. Because most existing contributions about their design rely on optimization and sensitivity analysis procedures, which are computationally demanding, or on analytic methods, which may be limited to small-amplitude motions, this thesis sets the emphasis on a tuning procedure of nonlinear vibration absorbers that can be computationally tractable and treat strongly nonlinear regimes of motion. The proposed methodology is a two-step procedure relying on a frequency-energy based approach followed by a bifurcation analysis. The first step, carried out in the free vibration case, imposes the absorber to possess a qualitatively similar dependence on energy as the primary system. This gives rise to an optimal nonlinear functional form and an initial set of absorber parameters. Based upon these initial results, the second step, carried out in the forced vibration case, exploits the relevant information contained within the nonlinear frequency response functions, namely, the bifurcation points. Their tracking in parameter space enables the adjustment of the design parameter values to reach a suitable tuning of the absorber. The use of the resulting integrated tuning methodology on nonlinear vibration absorbers coupled to systems with nonlinear damping is then investigated. The objective lies in determining an appropriate functional form for the absorber so that the limit cycle oscillation suppression is maximized. Finally, the proposed tuning methodology of nonlinear vibration absorbers may impose the use of complicated nonlinear functional forms whose practical realization, using mechanical elements, may be difficult. In this context, an electro-mechanical nonlinear vibration absorber relying on piezoelectric shunting possesses attractive features as various functional forms for the absorber nonlinearity can be achieved through proper circuit design. The foundation of this new approach are laid down and the perspectives are discussed.

This thesis deals with development and synthesis of organic chromophores for dye sensitized solar cells. The chromophores are divided into three components; donor, linker and acceptor. The development of efficient organic chromophores for dye sensitized solar cells starts off with one new organic chromophore, D5. This chromophore consists of a triphenylamine moiety as an electron donor, a conjugated linker with a thiophene moiety and cyanoacrylic acid as an electron acceptor and anchoring group. Alternating the donor, linker or acceptor moieties independently, would give us the tool to tune the HOMO and LUMO energy levels of the chromophores. The following parts of this thesis regard this development strategy. The contributions to the HOMO and LUMO energy levels were investigated when alternating the linker moiety. Unexpected effects of the solar cell performances when increasing the linker length were revealed, however. In addition, the effect of an alternative acceptor group, rhodanine-3-acetic acid, in combination with different linker lengths was investigated. The HOMO and LUMO energy level tuning was once again successful. Electron recombination from the semiconductor to the electrolyte is probably the cause of the poor efficiencies obtained for this series of dyes. Finally, the development of functionalized triphenylamine based donors and the contributions from different substituents to the HOMO and LUMO energy levels and as insulating layers were investigated. This strategy has so far been the most successful in terms of reaching high efficiencies in the solar cell. A top overall efficiency of 7.79 % was achieved. / QC 20100716

Positive systems, which carry the well known property of confining the state, output, and/or input variables to the nonnegative orphant, are of great practical importance, as the nonnegative property occurs quite frequently in numerous applications and in nature. These type of systems frequently occur in hydrology where they are used to model natural and artificial networks of reservoirs; in biology where they are used to describe the transportation, accumulation, and drainage processes of elements and compounds like hormones, glucose, insulin, and metals; and in stocking, industrial, and engineering systems where chemical reactions, heat exchanges, and distillation processes take place. The interest of this dissertation is in two key problems: positive stabilization and the positive servomechanism problem. In particular, this thesis outlines the necessary and sufficient conditions for the stabilization of positive linear time-invariant (LTI) systems using state feedback control, along with providing an algorithm for constructing such a stabilizing regulator. Moreover, the results on stabilization also encompass the two problems of the positive separation principle and stabilization via observer design. The second, and most emphasized, problem of this dissertation considers the positive servomechanism problem for both single-input single-output (SISO) and multi-input multi-output (MIMO) stable positive LTI systems. The study of the positive servomechanism problem focuses on the tracking problem of nonnegative constant reference signals for unknown/known stable SISO/MIMO positive LTI systems with nonnegative unmeasurable/measurable constant disturbances via switching tuning clamping regulators (TcR), linear quadratic clamping regulators (LTQcR), and ending with MPC control. Finally, all theoretical results on the positive servomechanism problem are justified via numerous experimental results on a waterworks system.