Hybrid stepper motors are small electrical motors with high torque production, compared with other electrical motors of the same size. Hybrid stepper motors are reliable in open-loop systems, in Sinusoidal mode, but with a drawback of high power consumption. The power consumption may be reduced by Field-Oriented Control, but this control mode requires a positioning sensor, adding size and cost to the system. This Master’s Thesis explores the possibilities of observer-based Field-Oriented Control on a two-phase hybrid stepper motor without using a positioning sensor, run on a microprocessor and executed during the interrupt scheduling routine, coded in C/C++.

The original idea of the thesis was realized to control the electric drive of the rotor with a special feature. Without using a complex mechanism, the angle of each blade of the rotor can be controlled individually. The blades are fixed independently to a permanent magnet and the housing encompassing the rotor contains coils. By powering the coils, the whole rotor turns into a permanent magnet motor and by using a control algorithm, each blade can be separately driven. In the first chapter, the introduction to the main idea of the research project is described along with working principle of rotor blade. The basic concept of blade angle is introduced. The second chapter is the state of Technique. In this chapter, the working principle and basics of permanent magnet synchronous machine and brushless motor with mathematical model is described. Also, space vector pulse width modulation and double acting piezoelectric actuator model for helicopter rotor are explained. The third chapter is the overall description of the initial status of the research project. This part includes the basic principle of the control system, sensorless field-oriented control of Permanent Magnet Synchronous Machine (PMSM). Also, the motor parameters calculated from the python script of motor design are listed in tabular form. The fourth chapter focuses on control strategy implementation. First of all, the criteria for selecting the microcontroller are described. After that, the structure of the program with a flow chart was explained. Also, a short description is mentioned of how space vector pulse width modulation is applied. The main function of the position and speed controller with block diagram is explained. Moreover, back-EMF based observer and EKF-based observer are described. In the fourth chapter, the initial problem of the research project is discussed. To overcome this problem, a set of experiments is carried out. In the last chapter, the result of the experiment with proper explanation is summarized. Further on the future work to solve the problem is listed.

Esta tesis doctoral profundiza, desde el punto de vista de la ecología y la biodemografía humanas, en el estudio de la población chilena austral de la Isla Grande de Tierra del Fuego, especialmente en lo que se refiere a la caracterización de la historia reproductora y el análisis de la fecundidad de las mujeres de la población. Con tal fin se analizan dos fuentes de información. Por un lado, encuestas de fecundidad a mujeres en edad posreproductora representativas de la población fueguina nacidas entre 1912 y 1956. Por otro lado, la reconstrucción de familias a partir de la interrelación de los registros de matrimonios, nacimientos y defunciones de sus habitantes desde 1897 hasta 1997 obtenidos en las oficinas del Registro Civil de Punta Arenas y de Porvenir. Se hace especial énfasis en la descripción de los distintos sucesos que caracterizan la historia reproductiva de las mujeres. Desde el inicio de su intervalo fecundo con la menarquia y el establecimiento de la única o diversas uniones conyugales, hasta el nacimiento de sus diversos hijos y la aparición de la menopausia, final de su periodo fecundo. Multitud de parámetros biológicos interesan en esta tesis doctoral, en relación con variables de la madre o de la evolución en distintas generaciones de una misma familia: el tamaño de las familias, la incidencia de la aborción espontánea y los métodos anticonceptivos cuando los hubo, la longitud de los intervalos protogenésico e intergenésicos (espacio entre los hijos), las edades de las madres al nacimiento de sus hijos, la paridad de los diversos nacimientos, y todos los factores biológicos, socioculturales o ambientales que pueden influir en estos y otros parámetros. Para el análisis de la fecundidad se realizan dos aproximaciones bien distintas e independientes que aportan resultados similares e información complementaria. En primer lugar, se realiza un análisis de los principales determinantes de la fecundidad y de su evolución temporal mediante el modelo agregativo de Bongaarts y Potter. A continuación, se profundiza en las interconexiones de los distintos eventos e intervalos de la historia reproductiva de las mujeres y se propone un modelo que las explique significativamente a partir del path analysis. Entre las conclusiones del presente estudio destaca que la fecundidad de las mujeres fueguinas está condicionada por diversos factores que la limitan y que actúan a través de los determinantes próximos. Fundamentalmente, los patrones de nupcialidad (la relativamente tardía entrada al matrimonio, la separación y viudedad tempranas y la incidencia del celibato definitivo) y el uso extendido de técnicas anticonceptivas modernas, aunque también las características que definen el patrón de espaciamiento de la descendencia, son esenciales para explicar los niveles de fecundidad alcanzados por la población fueguina. / "Reproductive history and fertility analysis of women from Tierra del Fuego" TEXT:This is a biodemographic study of the population of Chilean part of Tierra del Fuego and we are interested in establishing the fertility model of the population. The reproductive history of 182 women in postreproductive life or near menopause from this population was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement and their reproductive years were spent in the island. Bongaarts' aggregative method and path analysis have been applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. Also family reconstitution has been used to complete the characterization of reproductive pattern of women from Tierra del Fuego. For this purpose we analyze civil registers of marriages, births and deaths of Fuegian people located in Punta Arenas (Magellanic capital) and Porvenir (Fuegian capital) from 1897 to 1997.The reproductive history of women is characterized by a long fertile span, a short childbearing period and a low fertility. Age at menarche is relatively late and age of women at first birth is mainly determined by the late age at marriage. Use of contraception is related to both spacing and stopping behavior. A late age of women at marriage, the rhythm of conception and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.

El fuego bacteriano, causado por Erwinia amylovora, es una enfermedad muy importante a nivel comercial y económico porque afecta a plantas de la familia de las rosáceas y es especialmente agresiva en manzano (Pyrus malus) y peral (Pyrus communis), así como en plantas ornamentales (Crataegus, Cotoneaster o Pyracantha). Esta enfermedad está distribuida por todo el mundo en zonas climáticas templadas de Amércia del Norte, Nueva Zelanda, Japón, Israel, Turquí y Europa. En España, el fuego bacteriano fue detectado por primera vez en 1995 en el norte del País (Euskadi) y más tarde en nuevos focos aparecidos en otras áreas. La enfermedad puede ser controlada comercialmente mediante la aplicación de pesticidas quimicos (derivados de cobre, antibioticos). Sin embargo, muchos de los productos químicos presentan baja actividad o causan fitotoxicidad, y la estreptomicina, el producto más eficaz, esta prohibido en muchos países, incluyendo España. Por tanto, en ausencia de apropiados agentes químicos, el control biológico se contempla como una buena alternativa. En el presente trabajo, un agente de control biológico, Pseudomonas fluorescens EPS62e, ha sido seleccionada de entre 600 aislados de las especies P. fluorescens y Pantoea agglomerans obtenidos de flores, frutos y hojas de plantas de la familia de las rosáceas durante una prospección llevada a cabo en varias áreas geográficas de España. La cepa ha sido seleccionada por su capacidad de suprimir la infecciones producidas por E. amylovora frutos inmaduros, flores y brotes de peral en condiciones de ambiente controlado, presentando unos niveles de control similares a los obtenidos mediante el control químico usando derivados de cobre o antibióticos. La cepa además ha mostrado la capacidad de colonizar y sobrevivir en flores y heridas producidas en frutos inmaduros en condiciones de ambiento controlado pero también en flores en condiciones de campo. La exclusión de E. amylovora medinate la colonización de la superficie, el consumo de nutrientes, y la interacción entre las células del patógeno y del agente de biocontrol es la principal causa de la inhibición del fuego bacteriano por la cepa EPS62e. Estas características constituyen aspectos interesantes para un desarrollo efectivo de la cepa EPS62e como un agente de biocontrol del fuego bacteriano en condiciones comerciales. / Fire blight, caused by Erwinia amylovora is a serious disease of rosaceous plants with great commercial and economic interest that is distributed over the world. Disease may be controlled commercially by the application of chemicals (copper compounds, antibiotics). Many chemical agents have low activity or cause phytotoxicity, and streptomycin, the most effective antibiotic, is not approved for use in many countries, including Spain. Therefore, in the absence of suitable chemical control agents, biological control could provide a useful alternative. In the present work, a biological control agent, Pseudomonas fluorescens EPS62e, has been selected among 600 isolates of P. fluorescens and Pantoea agglomerans obtained from flowers, fruits and leaves of rosaceous plants in a survey performed through several geographic areas of Spain. This strain has been selected for its capacity to suppress immature fruit, blossom and shoot infections caused by E. amylovora, under controlled environment conditions, providing control levels similar to chemical control with copper or antibiotic compounds. The strain has also shown the capacity to colonize and survive well in flowers and wounds on immature fruit under controlled environment conditions but also in flowers under natural conditions. Pre-emptive exclusion of the pathogen E. amylovora by surface colonization and nutrients depletion, and cell-to-cell interaction appear to be the main mechanisms of biocontrol. These characteristics constitute interesting traits for an effective development as a fire blight biological control agent under commercial conditions.

Pseudomonas fluorescens EPS62e es va seleccionar com a agent de biocontrol del foc bacterià per la seva eficàcia en el control de Erwinia amylovora. En aquest treball es van desenvolupar mètodes de traçabilitat que van permetre la seva detecció específica i quantificació. Mitjançant les tècniques RAPD i U-PCR es van obtenir fragments d'amplificació diferencial per EPS62e que es van seqüenciar i caracteritzar com marcadors SCAR per dissenyar una PCR en temps real. La PCR a temps real es va utilitzar simultàniament amb mètodes microbiològics per estudiar l'adaptabilitat epifítica de EPS62e en pomera i perera. L'ús combinat de mètodes microbiològics i moleculars va permetre la identificació de tres estats fisiològics de EPS62e: la colonització activa, l'entrada en un estat de viable però no cultivable, i la mort cel·lular. Aquest treball mostra que EPS62e està ben adaptada a la colonització de flors a camp, encoratjant la seva utilització dins d'una estratègia de control biològic contra el foc bacterià. / Pseudomonas fluorescens EPS62e was selected as a reliable biological control agent of fire blight for its high efficacy controlling Erwinia amylovora infections. In the present work, monitoring methods which allowed EPS62e specific detection and quantification were developed. RAPD and U-PCR fingerprints were used to obtain differential amplified fragments from EPS62e that were sequence characterized as SCAR markers. A real-time PCR was developed on the basis of the strain-specific SCAR markers, and was used simultaneously with microbiological methods to study the environmental fate of EPS62e in apple and pear orchards. The combined use of both microbiological and molecular methods permitted the identification of three physiological states for EPS62e, which consisted of active colonization, survival and entry into a viable but nonculturable state, and cell death. The present work shows that EPS62e is well adapted for blossom colonisation in the field, and encourages its utilisation in a fire blight.

An optimization of a servo system for a satellite antenna system wasperformed. A brushless DC motor with an angle encoder was used, whoseangular velocity had to be controlled with great precision. Specializedhardware was used to implement field oriented control to directlycontrol the torque and magnetic flux of the motor. Multiple velocitycontrollers were tested for the closed servo system, which controlledthe amplitude of the motor current to achieve the given reference valuefor the angular velocity. A PI regulator was tested and evaluated aslacking in terms of precision, which was caused by low resolution of theerror signal for the angular velocity of the motor. This in turn wascaused by low resolution of the angular velocity measurement. Theanguluar velocity error signal was filtered to combat this, and a feedforward method was implemented where the reference value for the angularvelocity was integrated over time to generate a reference value for theangular position. Since the angular position could be measured withbetter precision, a better error signal based on the angular positioncould be generated which was then used as input to another regulatorwhose output signal was added to the original regulator to increase theaccuracy of the system significantly. The two regulator output signalswere then weighted based on the reference value for the angularvelocity. This was done because the two regulators performed well fordifferent velocity bands, which this method took into consideration. Thefinal servosystem fullfilled the set requirements by a good margin.

A permanent magnet synchronous motor is a type of motor that is used in several different application areas, not least in an autonomous robots where it is the motor that drives the wheels. Today, many actors choose simulation as a tool to save money and time when product tests are performed. This thesis covers both the process of modeling a permanent magnet synchronous motor and regulating it at low speeds, in a simulation environment. As previously mentioned, the motor is a permanent magnet synchronous motor and is a direct-driven outrunner, which means that the motor and the wheel are combined and that the rotor is spinning outside the stator. On current robots in production, there is a gear ratio between the motor and wheels to be able to regulate the motor at higher speeds and thus generate a torque. The gearing contributes to losses and is an extra cost, so the examination of a direct-drive motor is interesting. The direct-drive motor has a lower working speed and is therefore by some reasons more difficult to regulate when applying torque load to the motor. The motor is equipped with current sensors and a position sensor, which has a certain resolution. The position sensor is speed-dependent in the sense that at lower RPMs fewer measurements are obtained, which is a problem when regulating the motor. The thesis examines two different control strategies, one of which is a more classic PI control that is often used on the market in various systems and the other is model predictive control (MPC). The latter is an online optimization where, with the help of information about the system, an optimal input signal is calculated and applied. Two different non-linear Kalman filters are also examined, which are implemented with the two different control strategies, to estimate the speed with the help of the measurements from current and the position sensor. The conclusion is an ideal motor model that mimics the physical motor. MPC is able to regulate the motor between 0-50 RPM, both with and without applied torque and even better with speed estimation from a Kalman filter. The PI controller is not able to regulate the motor at 2 RPM but for speeds at 10 RPM and greater, however with over-/undershoot after an acceleration.

The objective of the dissertation is to develop simplified analytical models for typical linear-motion and rotary-motion energy-conversion systems under active DC excitation without tedious numerical-simulation effort, and provide practical implementation of the models in optimal-design and thermal-protection aspects. The model of a vacuum automatic circuit recloser (a typical linear-motion system under DC excitation) is first developed in the form of a non-linear discontinuous eighth-order dynamic system. The model is then used to simulate the transient mechanical and electromagnetic performance during the opening and closing movements of the recloser. Such a model is not found in the literature. Although the model is based on certain simplifying assumptions, the result is validated by high-speed-camera measurements. In addition, the impact of key design variables is explored, based on which an improved recloser design is proposed, and helps to optimize capital and production costs without degrading performance. Further analytical investigation is carried out in modeling an inverter-fed induction motor (IM) (a typical rotary-motion system) with active DC injection. The IM is closed-loop controlled via two popular motor-control algorithms, namely, the direct-torque-control (DTC) algorithm and field-oriented-control (FOC) algorithm. Quantitative relationships between the changes of various machine variables during the active DC excitation are provided in the theoretical analysis. The developed DC-injection model is further simplified for practical implementation. The developed IM model under DC injection results in practical ways to excite a proper amount of DC current directly or indirectly into IM stator windings via different closed-loop motor-control algorithms. In a DTC motor-drive system, the modeling work makes it possible to excite the DC current indirectly inside the motor by superimposing a stator-flux-linkage-bias command in the flux-control loop or a torque-ripple command in the torque-control loop. The proposed flux-linkage-injection and torque-injection methods are the first novel efforts to implement the DC-signal-injection method in a DTC motor-drive system. In addition, the analysis carried out in a standard FOC drive system brings about an improved DC-current-injection approach: the torque ripple in this method is significantly mitigated compared to all existing DC-injection methods in FOC systems. The proposed DC-injection methods, either in a DTC or an FOC system, lead to a simple, low-cost, accurate, and non-invasive thermal-monitoring scheme for closed-loop-controlled IMs, where the stator temperature is indirectly estimated from stator resistance. Furthermore, considering inverter non-idealities, there is a challenge for a typical inverter drive to accurately estimate the DC component of motor terminal voltages. The existing methods are extended to provide a complete study of the real-time signal-processing technique for both DTC and FOC algorithms, and are finally implemented in a custom-built programmable motor-drive system. The experimental results demonstrate that the proposed technique gives accurate and robust stator-temperature estimation, regardless of the operating conditions and cooling modes. The analytical modeling method for the linear-motion and rotary-motion energy-conversion systems can be further extended to other power devices with similar mechanisms, and implemented in optimal design, control, and thermal-protection areas.

Made available in DSpace on 2016-04-26T20:20:46Z (GMT). No. of bitstreams: 1 Marcelino Andre Stein.pdf: 1124431 bytes, checksum: c1ffbf0839b099ad8f101e78bf0f31fa (MD5) Previous issue date: 2012-03-21 / This study aims to discuss the main legal and economic aspects of flags of convenience (FOC). Its specific objectives, are to help reduce dependence by Brazilian users of shipping services provided by carriers that make extensive use of flags of convenience. As justification for the study, we note that it is an important issue for long-term strategic interests of the Brazilian State. The development of a long-term State Maritime Policy is critical to a Country that has one of the largest coasts and internal waterway networks in the world. The hypothesis addressed in this work is the study of the major legal and economic aspects of flags of convenience as well as the possibility of using the WTO through the GATS, to combat this practice or, alternatively, adapt it to the entire international maritime community so all Countries and their Merchant Marines can enjoy the same legal framework. The method is inductive, since the author will depart from particular issues to achieve generalized conclusions. This method extends the freedom of the researcher, allowing him to consult a variety of sources, so that, intuitively, the author can reach the proposed result. Emphasis will be given to the impact that these flags of convenience cause to the development of a Brazilian Maritime Power as well as a Brazilian strong Merchant Marine and possibilities of using the WTO Word Trade Organization, to curb this practice. It is argued that this practice violates the GATS (General Agreement on Tariffs and Services) rules, highlighting unfair competition in the international maritime market / Esta dissertação tem como objetivo geral contribuir para a redução da dependência dos usuários brasileiros de serviços de transportes marítimos prestados pelos navios de bandeiras de conveniência. Trata-se de tema importante para os interesses estratégicos de longo prazo do Estado brasileiro, o que justifica a relevância desta pesquisa. A elaboração de uma Política Marítima de Estado, de longo prazo, é fundamental para um país que tem uma das maiores costas e malhas hidroviárias do mundo. A hipótese desta pesquisa sustenta que o estudo dos principais aspectos jurídicos e econômicos das bandeiras de conveniência, bem como a possibilidade de uso da Organização Mundial do Comércio, através do Acordo Geral de Tarifas e Serviços GATS (General Agreement on Trade in Services - GATS), para combater tal prática, ou adequá-la para que toda a comunidade marítima internacional possa dela usufruir. O método utilizado é o indutivo, pois partir-se-á de questões particulares para conclusões generalizadas. Este método amplia a liberdade do pesquisador, ao lhe dar a liberdade de beber em diversas fontes para que, intuitivamente, chegue ao resultado proposto. Será dada ênfase ao impacto que tais bandeiras causam na construção do Poder Marítimo brasileiro e possibilidades de uso da Organização Mundial do Comércio para coibir tal prática. Sustenta-se que tal prática viola o GATS tendo em vista a concorrência desleal no mercado internacional marítimo

L'hypothalamus latéral (LHA) est impliqué dans un grand nombre de fonctions dont les principales sont la régulation du métabolisme énergétique et des états de vigilance. L'objectif de ce travail est de caractériser les grandes divisions du LHA et d'analyser leur implication dans le cycle veille / sommeil et la prise alimentaire. Une comparaison de la distribution de différents marqueurs hypothalamiques révélés par immunohistochimie ou hybridation in situ a permis de mettre en évidence cinq domaines dans le LHA. L'implication de chacun des domaines dans des conditions expérimentales liées aux états d'éveil ou à la prise alimentaire a été définie à partir de l'expression d'un marqueur d'activation neuronale, la protéine c-Fos. LeLHA antérieur et le LHA tubéral, chacun divisé en deux domaines rostral et caudal, sont composés de neurones localisés de manière diffuse et sont impliqués dans les phénomènes d'activation générale du système nerveux central. Le LHA mamillaire est renommé LHA prémamillaire à partir de l'étude de la distribution des ARNm GAD et préprotachykinine, et est composé de différents noyaux caractérisés par l'expression de marqueurs spécifiques.Parmi eux, les noyaux parasousthalamique (PSTN) et calbindine (CbN) sont activés lors d'exposition à des goûts de valeur hédonique positive. Les analyses hodologiques ont montré que ce complexe nucléaire reçoit des projections CGRP du noyau parabrachial et projette dansle noyau central de l'amygdale. Il est également connecté avec le cortex insulaire. Ces différentes structures sont impliquées dans les circuits de la gustation et de la récompense. Le PSTN et le CbN sont donc intégrés dans différentes voies de régulation du comportement de prise alimentaire. Enfin, les données morpho fonctionnelles obtenues pour le LHA sont mises en relation avec des réseaux impliquant diverses structures cérébrales telles que le télencéphale basal, le thalamus ou le mésencéphale. / The lateral hypothalamic area (LHA) is involved in many functions, but mainly in food intakeor sleep / wake cycle regulation. The aim of this study is to characterize the main regions inthe LHA and to analyze their involvement in the sleep / wake cycle and food intake. Acomparison of the distribution of different hypothalamic markers labeled byimmunohistochemistry or in situ hybridization highlights five domains in the LHA. Theimplication of each domain in different experimental conditions linked to arousal or foodintake is analyzed by studying the expression of the c-Fos protein as a neuronal activationmarker. Neurons in the anterior and tuberal LHA, both divided into rostral and caudaldomains, are distributed in a diffuse way and are activated under arousal conditions. Themammillary LHA, renamed the premammillary LHA on the basis of GAD andpreprotachykinin mRNA expression, is composed of several nuclei characterized by specificmarker expression. Among them, the parasubthalamic nucleus (PSTN) and the calbindinnucleus (CbN) are activated by ingestion of compounds with a positive taste. Theconnectional analysis showed that these two structures receive CGRP projections from theparabrachial nucleus and projects into the central nucleus of the amygdala. The PSTN / CbNcomplex is also connected with the insular cortex. These different structures are known to beinvolved in gustatory and reward circuitries; the PSTN and the CbN are thus integrated innetworks controlling the food intake behavior. Finally, the morphofunctional data obtainedfor the LHA demonstrate that this region is connected to other networks involving variouscerebral structures such as the basal telencephalon, the thalamus or the mesencephalon.