Controle em modo dual adaptativo robusto aplicado a um sistema de geração de energia elétrica

Synchronous machines, widely used in energy generation systems, require constant voltage and frequency to obtain good quality of energy. However, for large load variati- ons, it is difficult to maintain outputs on nominal values due to parametric uncertainties, nonlinearities and coupling among variables. Then, we propose to apply the Dual Mode Adaptive Robust Controller (DMARC) in the field flux control loop, replacing the tradi- tional PI controller. The DMARC links a Model Reference Adaptive Controller (MRAC) and a Variable Structure Model Reference Adaptive Controller (VS-MRAC), incorpora- ting transient performance advantages from VS-MRAC and steady state properties from MRAC. Moreover, simulation results are included to corroborate the theoretical studies.

Controle adaptativo com desacoplamento aplicado a um sistema de tanques acoplados MIMO

O controle de sistemas MIMO (Multiple Input Multiple Output) é muitas vezes realizado por várias malhas de controladores clássicos que operam com restrições e apresentam baixo desempenho. Técnicas de controle adaptativo são uma alternativa interessante para aumentar o rendimento desses sistemas, como por exemplo os controladores MRAC (Model Reference Adaptive Control), que quando bem projetados, permitem que a dinâmica da planta seja escolhida de maneira a seguir um modelo de referência. O presente trabalho apresenta uma estratégia de desacoplamento para um sistema MIMO de três tanques acoplados e o projeto de um controlador MRAC para o mesmo.

Controle adaptativo com desacoplamento aplicado a um sistema de tanques acoplados MIMO

O controle de sistemas MIMO (Multiple Input Multiple Output) é muitas vezes realizado por várias malhas de controladores clássicos que operam com restrições e apresentam baixo desempenho. Técnicas de controle adaptativo são uma alternativa interessante para aumentar o rendimento desses sistemas, como por exemplo os controladores MRAC (Model Reference Adaptive Control), que quando bem projetados, permitem que a dinâmica da planta seja escolhida de maneira a seguir um modelo de referência. O presente trabalho apresenta uma estratégia de desacoplamento para um sistema MIMO de três tanques acoplados e o projeto de um controlador MRAC para o mesmo.

Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

Utilizando a porta paralela para controle remoto de um dispositivo

VALENTIM, R. A. M.; NOGUEIRA, I. A.;ROCHA NETO, A. F. Utilizando a porta paralela para controle remoto de um dispositivo. Revista da FARN, Natal, v. 2, p. 103-114, 2002.

Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo

BRITTO, Ricardo S.; MEDEIROS, Adelardo A. D.; ALSINA, Pablo J. Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo. In: SIMPÓSIO BRASILEIRO DE AUTOMAÇÃO INTELIGENTE,8., 2007, Florianópolis. Anais... Florianópolis: SBAI, 2007.

SISAL - Um sistema supervisório para elevação artificial de petróleo

MEDEIROS, Adelardo A. D. et al. SISAL - Um Sistema Supervisório para Elevação Artificial de Petróleo. In: Rio Oil and Gas Expo Conference, 2006, Rio de Janeiro, RJ. Anais... Rio de Janeiro, 2006.

Impactos da adoção de sistemas de informação no judiciário: pesquisa com usuários do sistema processual virtual em um juizado especial federal

The Information Technology (IT) is increasing his applicability to business, both private and public companies. It is necessary the adequate use of the new technologies and get cooperation and technology acceptance of the system. People tend to resist to the changes, contributing so that the technology is rejected or even it is not recognized as promoting of the changes. This study is relevant and aim to evaluate the impacts of new technologies, considering their users as fundamental factors in the change process. The survey analyzed the advantages and the barriers of the system use in three federal special judicial of Rio Grande do Norte, with data collected in May of 2007, through the application of questionnaires to thirty eight users of the virtual system CRETA. The users' perception was evaluated, under the optics of five variables: efficiency, image, agility, ease of use and quality. Starting from the obtained results, it was evidenced that the implementation of the system felt accordingly the expected and it reached the objectives intended that were: the velocity and efficiency in the path of the lawsuits, larger productivity, resulting in a better quality of the final work introduced to the citizen and proportionate an improvement in the organizational image of the judiciary power

Ação de polissacarídeos sulfatados de Fucus Vesiculosus na Hemostasia e no sistema complemento

Fucans are a family of sulfated homo and teropolysaccharides respectively, composed mainly of a- (1®2) and a- (1®3) linked by L-fucose residues. Properties such as the ability to act as an anti-contraceptive, to reduce cholesterol levels, and to act as an anti-tumor agent are much related. We have focused our attention on the anticoagulant properties, platelet aggregation, hemorrhagic activity and complement system in vitro of commercial fucoidan (F) and their purified fractions (F1, F2 and F3) from Fucus vesiculosus obtained from fractionation of the fucoidan with different concentrations of acetone 1, 2 and 3v. These compounds were chemically characterized and the fucoidan (F) was modified by desulfation. The anticoagulant activity of the compounds was assessment by activated partial thromboplastin time (APTT) and prothrombine time assay (PT) using citrated normal human plasma. The results of APPT test showed that F, F1 and F2 have high anticoagulants activities 240.0 s (5 µg). The F3 showed 73.7 s in the same concentrations. The results obtained with PT test to F, F1, F2 and F3 were 81.5 s, 120.0 s, 57.1 and 32.5 s respectively with 50 µg. The dessulfated polymer showed a decrease in the anticoagulant activity in these two tests. Platelet aggregation assay was measured turbidimetrically with platelet aggregometer by method of Born. The aggregation platelet with F and fractions F1, F2 and F3 exhibited a two-phase answer in the concentration of 5 mg/mL with maximum aggregation of 76.36 ± 10.3% ; 69.54 ± 9.40%; 75.94 ± 9.01%; 51.13 ± 9.59% respectively. However, was observed a hipoaggregate profile F (15.17 ± 5.2%), F1 (7.40 ± 3.04 %), F2 (19.1 ± 5.41%) and F3 (5.09 ± 3.02%) at 0.1 mg/mL. The hemorrhagic activity assay was carried in Wistar rats and showed that these compounds have low hemorrhagic effect when compared to heparin. The complement system ( alternative pathway was made using non-sensibilized rabbit red blood cells The results of complement system essay showed that F , F2 and F3 have action inhibitory in relation to the group control 0.544, 0.697, 0.622 and 0.958 respectively The results showed that these compounds have action on this system. Interaction of the polisaccharides with proteins C3 and C4 showed that the fraction F1 stimulated the activity assay hemolytic using red blood cells

Estudo comparativo do desempenho de controladores robustos aplicados a um sistema de tanques acoplados.

Currently the uncertain system has attracted much academic community from the standpoint of scientific research and also practical applications. A series of mathematical approaches emerge in order to troubleshoot the uncertainties of real physical systems. In this context, the work presented here focuses on the application of control theory in a nonlinear dynamical system with parametric variations in order and robustness. We used as the practical application of this work, a system of tanks Quanser associates, in a configuration, whose mathematical model is represented by a second order system with input and output (SISO). The control system is performed by PID controllers, designed by various techniques, aiming to achieve robust performance and stability when subjected to parameter variations. Other controllers are designed with the intention of comparing the performance and robust stability of such systems. The results are obtained and compared from simulations in Matlab-simulink.

Um sistema para a inferência de variáveis usando redes neurais artificiais

This work aims to obtain a low-cost virtual sensor to estimate the quality of LPG. For the acquisition of data from a distillation tower, software HYSYS ® was used to simulate chemical processes. These data will be used for training and validation of an Artificial Neural Network (ANN). This network will aim to estimate from available simulated variables such as temperature, pressure and discharge flow of a distillation tower, the mole fraction of pentane present in LPG. Thus, allowing a better control of product quality

Sistema inteligente para apoio à decisão na operação de uma malha de escoamento de petróleo

The petroleum production pipeline networks are inherently complex, usually decentralized systems. Strict operational constraints are applied in order to prevent serious problems like environmental disasters or production losses. This paper describes an intelligent system to support decisions in the operation of these networks, proposing a staggering for the pumps of transfer stations that compose them. The intelligent system is formed by blocks which interconnect to process the information and generate the suggestions to the operator. The main block of the system uses fuzzy logic to provide a control based on rules, which incorporate knowledge from experts. Tests performed in the simulation environment provided good results, indicating the applicability of the system in a real oil production environment. The use of the stagger proposed by the system allows a prioritization of the transfer in the network and a flow programming

Controle aplicado a poços com método de elevação e bombeio centrífugo submerso

The Electrical Submersible Pumping is an artificial lift method for oil wells employed in onshore and offshore areas. The economic revenue of the petroleum production in a well depends on the oil flow and the availability of lifting equipment. The fewer the failures, the lower the revenue shortfall and costs to repair it. The frequency with which failures occur depends on the operating conditions to which the pumps are submitted. In high-productivity offshore wells monitoring is done by operators with engineering support 24h/day, which is not economically viable for the land areas. In this context, the automation of onshore wells has clear economic advantages. This work proposes a system capable of automatically control the operation of electrical submersible pumps, installed in oil wells, by an adjustment at the electric motor rotation based on signals provided by sensors installed on the surface and subsurface, keeping the pump operating within the recommended range, closest to the well s potential. Techniques are developed to estimate unmeasured variables, enabling the automation of wells that do not have all the required sensors. The automatic adjustment, according to an algorithm that runs on a programmable logic controller maintains the flow and submergence within acceptable parameters avoiding undesirable operating conditions, as the gas interference and high engine temperature, without need to resort to stopping the engine, which would reduce the its useful life. The control strategy described, based on modeling of physical phenomena and operational experience reported in literature, is materialized in terms of a fuzzy controller based on rules, and all generated information can be accompanied by a supervisory system

Atrás das grades: redes sociais, habitus e interação social no sistema carcerário do RN

Esta tesis trata de discutir y entender los diversos tipos de redes sociales y formas de interacción social presentes en el sistema penitenciario de Rio Grande do Norte. Nuestro problema se basa en un incremento significativo en las tasas de encarcelamiento y la prisión en Brasil y el mundo en los últimos diez años. Asimismo, la aparición del crimen organizado ya, en cierta medida, el control de las prisiones brasileñas, como el Comando Vermelho (CV) y el Primeiro Comando da Capital (PCC), una consecuencia directa de las terribles condiciones de las prisiones de Brasil y aumento de la violencia y el crimen en nuestro país. Para resolver el problema, se optó por utilizar las categorías de análisis de Michel Foucault (prisión y la disciplina), Pierre Bourdieu (habitus y campo), Ervirng Goffman (institución total, de interacción, de fachada y de equipo) y Mark Granovetter, Ricardo Abramovay e João Peixoto, entre otros, la nueva sociología económica (Redes, nodos y lazos) como principal apoyo. También construyó una revisión histórica de la cárcel en Brasil y Rio Grande do Norte hasta llegar al objeto. Esto, en términos de investigación cualitativa, se sumergió en el mundo de las prisiones Dr. Francisco Nogueira Fernandes, conocido como Penitenciario de Alcaçuz, ubicado en el municipio de Nísia Bosque, Rio Grande do Norte. Penitenciaría del Estado de origen, las casas de Alcaçuz seiscientos cuarenta y tres reclusos, divididos en cinco pabellones, un total de ciento cuarenta y siete células. Mediante la observación sistemática y la entrevista cualitativa s semi-estructurada como las principales fuentes de recopilación de datos, hemos tratado de explicar el universo que acabamos de analizar por las Ciencias Sociales. Nos dimos cuenta de que, para cumplir con la escena nacional, regaliz viola de manera flagrante lo que se denomina en la Constitución de 1988 y LEP (Ley de Ejecución Penal), sin tener en cuenta los derechos de los individuos a una porción de una oración con un mínimo de dignidad. Se ha demostrado que las personas que permean el universo proviene de un ambiente de la prisión, la sociabilidad violenta, sedo también tienen un habitus precario. La prisión, espacio disciplinario y un tipo específico de interacción social marcada por el control, contribuye a la profundización de habitus, pero que muestra que no es también como un espacio cerrado en absoluto, sino un lugar donde penetran las redes y dinámicas muy social. Al mismo tiempo, se encontró que más de la presencia de "grupos organizados" es el espacio en las cárceles para la interacción social y las redes sociales que pasan dentro y fuera de su espacio

Do controle de constitucionalidade dos atos jurisdicionais transitados em julgado

The following study aims to verify in which hypothesis res judicata, when it comes of an unconstitutional decision, shall not prevail over Constitution. It displayed the characteristics of formal and material constitutional systems. It debated the concepts of existence, validity and efficacy of juridical rules and acts. It dissertated about the idea of Constitution s superiority and about the birth of the judicial review of constitutionality. It focused some contemporary models of this judicial review and its historical evolution in Brazil, showing its effects towards the current Constitution. It sustained that the decision given by Supremo Tribunal Federal during abstract control of rules must bind even legislative bodies, preventing them to produce the same rules previously declared unconstitutional. It held up that all parts of the decision of Supremo Tribunal Federal oblige, even the juridical arguments employed, in both diffused and concentrated reviews. It showed that, despite these models of review live together in Brazil, our constitutional system preferred the concentrated one, considering one only court over the other constitutional organs. It discussed about res judicata with the purpose of clarifying its juridical nature, its objective and subjective limits and its regulation in collective demands. It explained that the material res judicata is an effect of a decision which cannot be reviewed, which makes the law s will free of discussion, binding the contendants and avoiding that other courts, judging future demands about the same object, may decide differently. It showed how the regulation of res judicata in collective demands, in respect oh their subjective limits, is useful to demonstrate that it is not the material law who must adapt itself to res judicata as traditionally thought, but res judicata, as a warranty of juridical certainty and security, who must be shaped from the debated rule. It presented to view the main doctrinal conceptions about res judicata s review in the hypothesis of unconstitutional judgement. It concluded that the decisions forged by unconstitutional rules or interpretations reputed not compatible to the Constitution by Supremo Tribunal Federal, in spite of it can make res judicata, may be reviewed beyond the term to file a recissory claim, since while the debated law is still valid, no matter if its decision was before or after the res judicata. At the end, it asserted that, when it is not legally authorized, the judicial review of res judicata is not admissible, after the term to file a recissory claim, under the argument that there was no direct violation to the constitutional principle or rule