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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Análise dos tempos máximos de chaveamento dos modos de operação de um grupo gerador diesel após ilhamento / Analysis of the maximum switching times of the operating modes for a diesel generator set after islanding

Agnoletto, Elian João 21 July 2015 (has links)
A produção de energia elétrica por fontes de geração distribuída (GD) vem se tornando cada vez mais presente no sistema elétrico de potência. De modo geral, os sistemas de GD conectados à rede de distribuição operam controlando potências ativa e reativa, enquanto que no modo isolado, a frequência e a tensão. Sendo assim, após a ocorrência de um ilhamento deve haver alteração no modo de operação da GD para garantir a estabilidade da frequência e da tensão no subsistema ilhado. Ainda, se o modo de operação não for alterado após o ilhamento, os dispositivos de proteção podem atuar desligando a GD. Portanto, o tempo decorrido até a alteração do modo de operação desempenha um papel importante na indicação se a GD permanecerá ou não em funcionamento após a ocorrência do ilhamento. Neste trabalho, são determinados os tempos máximos para chaveamento dos modos de operação de um grupo motor gerador diesel (GMG) operando como GD, utilizando controladores clássicos (CCs) e controladores fuzzy (CFs). Foram analisadas as influências do desbalanço entre as potências geradas e consumidas, do tipo de carga conectada ao subsistema ilhado e do comprimento do alimentador nos tempos máximos. Para evidenciar possíveis vantagens da estratégia de controle não linear, é utilizada uma metodologia na qual o ajuste dos ganhos dos CFs é realizado a partir dos ajustes de referência dos CCs. Devido ao ganho variável que a estratégia não linear adiciona às ações de controle, a utilização de CFs nas malhas do GMG permitiu maiores tempos de chaveamento para determinadas faixas de operação, quando comparado com a utilização de CCs. / Distributed generation (DG) is becoming more present in the electrical power system. In general, when a DG is connected to the grid, the DG works with the active and reactive power control loops. Therefore, after an islanding occurrence, the DG must change the operation control mode from power control to voltage and frequency control to maintain the system stability. If the operation mode is not changed after islanding, the protective devices are sensitized and the DG is disconnected. Therefore, the time elapsed until the operation mode changes has an important role in the indication if the DG remains in operation or not after islanding. In this work, the maximum times for switching the operating control mode of a diesel generator set, working as a DG, are analysed using a classical control strategy (CC) and a fuzzy control strategy (FC). The influence of the power imbalance, load types and the feeder distance on the maximum available time to switch the operation control mode is investigated. To highlight the advantages of a nonlinear control strategy, is used a methodology in which the tuning of the FCs gains is performed from the CCs which are used as reference. Due to the variable gain added by the nonlinear strategy, the FC allowed higher switching times than the CC.
82

Έλεγχος μηχανής συνεχούς ρεύματος τροφοδοτούμενης από τριφασικό πλήρως ελεγχόμενο αντιστροφέα

Μιχαλόπουλος, Ιωάννης 07 July 2015 (has links)
Σήμερα η ανάγκη για δημιουργία ποιοτικών και φθίνων και ανταγωνιστικών βιομηχανικών προϊόντων έχει σαν αποτέλεσμα να χρειαζόμαστε αυτοματισμούς και αυτόματο έλεγχο ηλεκτρικών μηχανών με μεγάλη ακρίβεια και αδιάλειπτη λειτουργία απο διαταραχές του περιβάλλοντος . Επιπλέον το ενεργειακό πρόβλημα που είναι από τα σπουδαιότερα προβλήματα του πλανήτη και του ανθρώπου σήμερα οδηγούν στην ανάγκη ελαχιστοποίησης των ενεργειακών απωλειών με αποτέλεσμα συνήθως να επιθυμούμε λειτουργία των ηλεκτρομηχανικών συστημάτων με μηδενική κατανάλωση/ παραγωγή άεργου ισχύος . Η Ηλεκτρική μηχανή συνεχούς ρεύματος με διέγερση σε σειρά χρησιμοποιείται λόγω των ιδιαίτερων χαρακτηριστικών της σε πολλές εφαρμογές που χρειάζονται υψηλή ροπή εκκίνησης όπως ανυψωτικά μηχανήματα, σιδηροδρομικά οχήματα. Οι ανορθωτές με ελεγχόμενη έναυση αλλά και σβέση κατά PWM προτιμούνται έναντι των διόδων και των θυρίστορς γιατί μας δίνουν περισσότερες δυνατότητες ελέγχου . Η Μοντελοποίηση , σχεδιασμός συστήματος ελέγχου, ευστάθειας του συστήματος για την μηχανή συνεχούς ρεύματος οδηγούμενης από τριφασικό ανορθωτή ερευνάται. Γίνεται εξαγωγή του μοντέλου, στο τριφασικό σύστημα και στο πλαίσιο park, με βάση την δυναμική ανάλυση Εuler -Lagrange . Για την εξαγωγή του μοντέλου γίνεται ακόμα χρήση του Averaging Analysis . Ανάλυση που βασίζεται στην παθητικότητα μάς δείχνει ότι το σύστημα είναι ευσταθές πεπερασμένης εισόδου-πεπερασμένης κατάστασης. Οι ελεγκτές που αναπτύσσονται σε αυτή τη εργασία είναι ο ασαφής ελεγκτής, ο νευροασαφής που χρησιμοποιούνται ευρέως σε μη γραμμικά συστήματα στην βιομηχανία, ο PI σειριακός (cascade) ελεγκτής που συνηθίζεται στις ηλεκτρικές μηχανές. Τέλος επιχειρείται ο σχεδιασμός ενός PI ελεγκτή με υπολογισμό κερδών από νευροασαφή εκτιμητή. Ο ασαφής ελεγκτής σχεδιάζεται με πρόβλεψη σφάλματος και επιτυγχάνει πολύ καλή ρύθμιση των στροφών και καλό έλεγχο στης αέργου ισχύος, εξομοιώσεις επιβεβαιώνουν την απόδοση του ελεγκτή. Ομοίως ισχύουν για τον νευροασαφή ελεγκτή με το πλεονέκτημα μικρότερου υπολογιστικού χρόνου αλλά μειονεκτεί μεγαλύτερης εμφάνισης ενός μόνιμου σφάλματος. Ο PI σειριακός (cascade) επιτυγχάνει άριστη ρύθμιση αέργου ισχύος και καλή ρύθμιση στροφών ενώ ο PI casacde- Anfis μας δίνει ελαφριά καλύτερα αποτελέσματα αλλά αφήνει αρκετές δυνατότητες για περαιτέρω σχεδιασμό και έρευνα. Επίσης γίνεται κάποια ανάλυση για εξαγωγή συμπερασμάτων ευστάθειας και σύγκλισης για τα σύστημα κλειστού βρόχου. Τα αποτελέσματα τα επιβεβαιώνουμε και τα συγκρίνουμε μέσω εξομοιώσεων. / Nowadays , the demand for precise control in industrial applications require the design and development of advanced controllers. Also the energy problem which is one of the most important global problems lead to the need of high energy efficient systems. In industrial applications in most cases ,due to the energy problem , we desire operation with unity power factor. The dc series connected motor is preferred in many application such as railway and levitating systems due to its high starting torque. We choose the 3 -phase pulse width modulation rectifier because of its many capabilities comparison with thyristor rectifiers. Modeling, control design and stability analysis of series connected dc motor fed by three-phase PWM ac/dc voltage converter are investigated. The designed controllers are fuzzy , neuro fuzzy, PI cascade and Anfis- pi cascade controller. The model is obtained via Euler -Lagrange dynamic analysis. Also we used the averaging analysis in order to determine the dynamic model of the system in a-b-c frame and d-q park's frame. We prove the ISS stability of the open loop system based on passivity analysis. The fuzzy use a predictive logic based on the acceleration of the motor, we result excellent precise control of angular velocity and a satisfied control of reactive power. Neuro Fuzzy controller has the same effectiveness with less computational effort but has a possibility to occur a small permanent error in angular velocity. PI cascade controller has as a result a excellent response at reactive power and good response in angular velocity with more less computational effort. ANFIS -PI cascade controller have a bit better results from PI-cascade controllers but it leaves hopes for more optimum designs in feature. Furthermore there are some stability and convergence analysis for the closed loop system. Simulation results verify the effectiveness of each controller for comparison.
83

Ασαφής έλεγχος ανάστροφου εκκρεμούς φορτίου (cart-ball) με χρήση προγραμματιζόμενου λογικού ελεγκτή

Τζώρτζης, Δημήτριος 04 November 2014 (has links)
Σκοπός της παρούσας διπλωματικής είναι ο έλεγχος ενός ανάστροφου εκκρεμούς φορτίου πλατφόρμας-σφαίρας (cart-ball) με χρήση ασαφούς ελέγχου ο οποίος υλοποιείται σε ηλεκτρονικό υπολογιστή στο περιβάλλον προγραμματισμού National Instruments LabVIEW 2009. Το φυσικό σύστημα αποτελείται από μία μεταλλική πλατφόρμα σταθερά προσδεδεμένη σε ένα γραμμικό άξονα της εταιρίας FESTO. Για την κίνηση του άξονα χρησιμοποιείται τριφασικός ηλεκτρικός σερβοκινητήρας, επίσης της FESTO, ο έλεγχος του οποίου γίνεται με χρήση ειδικού προγραμματιζόμενου ελεγκτή της ίδιας εταιρίας. Πάνω στην μεταλλική πλατφόρμα έχει τοποθετηθεί μία αψίδα παράλληλη στη διεύθυνση κίνησης της πλατφόρμας. Πάνω στην αψίδα έχουν δημιουργηθεί δύο οδηγοί επικαλυμμένοι με σκόνη γραφίτη σε μορφή κόλλας, η οποία τους κάνει ηλεκτρικά αγώγιμους. Ο ένας από τους οδηγούς έχει τάση 10V στα άκρα του ενώ το ένα άκρο του άλλου αγωγού είναι γειωμένο. Στόχος του αυτομάτου ελέγχου είναι να ισορροπήσει πάνω στην αψίδα μία μεταλλική σφαίρα. Η μεταλλική σφαίρα βραχυκυκλώνει τους δύο αγώγιμους οδηγούς και κατ' αυτό τον τρόπο, με την αρχή του ροοστάτη, λαμβάνεται η θέση της σφαίρας. Η μέτρηση της τιμής της θέσης της σφαίρας όπως και η θέση και η ταχύτητα της πλατφόρμας, οι οποίες λαμβάνονται από τον ελεγκτή του κινητήρα, εισάγονται στον υπολογιστή, μέσω ειδικής κάρτας Εισόδου/Εξόδου (Ε/Ε) της εταιρίας National Instruments, όπου λαμβάνονται από το LabVIEW και οδηγούνται στον ασαφή ελεγκτή που υλοποιείται στο ίδιο πρόγραμμα. Η ταχύτητα της σφαίρας λαμβάνεται επίσης υπ' όψιν στον αυτόματο έλεγχο και προκύπτει στο LabVIEW από παραγώγιση της θέσης της σφαίρας. Το ασαφές σύστημα αποτελείται από πέντε συναρτήσεις συμμετοχής για τη μεταβλητή της θέσης, τρεις συναρτήσεις συμμετοχής για τη μεταβλητή της ταχύτητας και εφτά συναρτήσεις συμμετοχής για την έξοδο του ελεγκτή που εκφράζει την επιθυμητή ταχύτητα της πλατφόρμας. Ο συμπερασμός γίνεται με χρήση 22 κανόνων. Η έξοδος του ασαφούς ελεγκτή εκφράζεται με μια τιμή από -10V έως +10V. Η έξοδος από τον ασαφή ελεγκτή οδηγείται πάλι μέσω της ειδικής κάρτας Ε/Ε στον προγραμματιζόμενο ελεγκτή του κινητήρα της FESTO ο οποίος ελέγχει κατάλληλα το ρεύμα τυλίγματος του κινητήρα ώστε να επιτευχθεί η επιθυμητή ταχύτητα. Η περίοδος του ελέγχου είναι 100 ms. Τα αποτελέσματα του ελέγχου του πιο πάνω συστήματος κρίνονται γενικά ικανοποιητικά δεδομένης της ισχυρής αστάθειας που το χαρακτηρίζει. / The subject of the thesis is the automatic control of an inverted pendulum consisting of a cart and a ball. We used fuzzy control to balance the ball on top of an arch. The controller was created in LabView 2009.
84

Emocijų atpažinimas tiriant žmogaus fiziologinius parametrus / Emotion recognition on researching human physiological parameters

Marozas, JULIUS, Marozas, Julius 25 August 2008 (has links)
Emocijų atpažinimas, tiriant žmogaus fiziologinius parametrus, yra labai aktualus šiuolaikinės informatikos mokslo uždavinys. Šio darbo siekis yra suprojektuoti emocijų atpažinimo sistemos prototipą, kurį su minimaliais kaštais galima būtų pritaikyti įvairiose emocijomis grindžiamose sistemose. Pateikiamas tokios sistemos koncepcinis modelis, susidedantis iš aparatūrinės įrangos ir programinio modelių. Fiziologinių signalų stiprinimui naudojami AD620 ir OP97 operaciniai stiprintuvai. Analoginio signalo keitimas ir perdavimas į kompiuterį atliekamas naudojant Atmega16 mikrovaldiklį. Schemų testavimui naudojamas kompiuterinis oscilografas (PCS500). Atliekamas skaitmeninio signalo filtravimo metodų tyrimas. Pristatomi fiziologinių parametrų fiksavimo metodų (EKG, SC) atpažinimo algoritmai, pagrįsti SVW algoritmu. Atliekama HRV spektrinė analizė į dažninę sritį, naudojant Furjė transformacijas. Pateikiama praplėsta neraiškioji valdymo sistema, kuri iš fiziologinių parametrų (HR, HRVL, HRVH, SCR, STpirštas, STgalva) išveda susijaudinimo–valentingumo laipsnius. Pagal šiuos laipsnius išvedamos emocijos. Aptariami sukurtų algoritmų, realizuojant juos realioje aplinkoje, nauji elgsenos charakteristikų ypatumai. / Very important task of modern computer science is emotion recognition by human physiological parameters. The purpose of this work is to design a prototype of emotion recognition system, which could be possible customize in various emotions systems with minimal costs. There is representing such system conceptual model, which consists from them realization hardware and programme models. For amplifying the physiological signals is using instrumental AD620 and high precision OP97 operations amplifiers. Analogical signal converting to digital and transmitting to the computer redundant by Atmega16 microcontroller. For electrical schemas testing is using oscillograph (PCS500) connected on the computer. It is redundant analysis for digital signal filtering methods. There is presenting the recognition algorithms, based on SVW algorithm, for physiological parameters fixing methods (ECG, SC). For HRV spectral analyze in frequency domain it is using Furies transformations. There is extended fuzzy control system, which deduces arousal–valence levels from physiological parameters (HR, HRVL, HRVH, SCR, STfinger, SThead). By theses levels is deduces emotions. The new characteristical singularities of designed algorithms in real environment are also discussed.
85

Estratégia de controle fuzzy para um grupo motor gerador a diesel operando isolado ou conectado à rede de distribuição / A fuzzy control strategy for a diesel generating set under stand-alone and grid-connected operations

Giann Braune Reis 01 April 2014 (has links)
Esta tese propõe uma estratégia de controle fuzzy para um grupo motor gerador a diesel como uma fonte de geração distribuída, cobrindo a parte mecânica do sistema que é composta por controle de velocidade e de potência ativa, a parte elétrica do sistema composta por controle de tensão e potência reativa, e também o controle de sincronismo com a rede de distribuição. A estratégia de controle foi baseada em lógica fuzzy que usou uma superfície de controle fixa para os controladores fuzzy. Foram investigados os distúrbios causados pelo efeito de conexão com a rede e da conexão de um motor de indução, um retificador não controlado e uma carga RLC. Resultados de simulação para fluxo de potência no modo conectado foram obtidos usando um alimentador padrão IEEE -1547. Os resultados de simulação obtidos para os modos isolado e conectado usando o controlador fuzzy foram superiores comparados aos resultados obtidos com um controlador comercial. Uma bancada experimental também foi usada para analisar a resposta do sistema no modo isolado com o controlador fuzzy proposto e com o controlador comercial para fins de comparação. Nesse contexto, espera-se com este trabalho contribuir para o desenvolvimento de pesquisas na área de controle e processamento de energia, uma vez que, soluções para a produção de energia utilizando a geração distribuída têm importância estratégica e têm sido foco de investimento e discussões por parte de governos, empresas e universidades. / This thesis proposes a control strategy for a diesel generating set as a distributed generation source covering the mechanical part of the system which includes speed and active power control, the electrical part of the system which includes voltage and reactive power control, and also the synchronism control with the grid. The control strategy was based on a fuzzy logic which used a fixed controller surface for the fuzzy controllers. The effect of the disturbances caused by the grid connection and the disturbances caused by the activation of a induction motor, non controled rectifier and a RLC load types were investigated. Power flow simulation results for the grid-connected mode was obtained with a IEEE -1547 standard feeder. The simulations results for both stand-alone and gridconnected operations using fuzzy controllers were superior when compared to commercial methods. An experimental setup was also used to analyze the system responses under isolated mode with the proposed fuzzy controller and with the commercial controllers for comparison proposes. In this context, it is expected that this work contributes to the development of control and energy processing research area, since solutions for energy production using distributed generation have strategic importance and have been the focus of investment and discussions from governments, companies and universities.
86

Contribution à la commande d'un train de véhicules intelligents / Contribution to intelligent vehicle platoon control

Zhao, Jin 02 September 2010 (has links)
Ce mémoire est consacré à la mise en œuvre de commandes d'un train de véhicules intelligents sur autoroute ayant pour objectifs principaux de réduire la congestion et d’améliorer la sécurité routière. Après avoir présenté l'état de l'art sur des systèmes de conduite automatisée, des modèles de la dynamique longitudinale et latérale du véhicule sont présentés. Ensuite, des stratégies de contrôle longitudinal et latéral sont étudiées.D'abord, le contrôle longitudinal est conçu pour être hiérarchique avec un contrôleur de niveau supérieur et un contrôleur de niveau inférieur. Pour celui de niveau supérieur, une régulation d'inter-distance SSP (Safety Spacing Policy) est proposée. Nous avons constaté que la SSP peut assurer la stabilité de la chaîne et la stabilité des flux de trafic et augmenter ainsi la capacité de trafic. Puis, pour celui de niveau inférieur, une loi de commande floue coordonnée est proposée pour gérer l'accélérateur et le freinage. Ensuite, une loi de commande multi-modèle floue est conçue pour le contrôle latéral. De plus, pour réaliser des transformations lisses entre les différentes opérations latérales, une architecture de contrôle hiérarchique est proposée. Puis, l'intégration des commandes longitudinale et latérale est étudiée. Enfin, l'estimation des variables d’états du véhicule est discutée. Un filtre de Kalman-Bucy est conçu pour estimer les états du véhicule. En outre, un prototype de véhicule intelligent à échelle réduite est également présenté. Les performances des divers algorithmes de commande proposés ont été testées par simulations, et les résultats ont été confirmés par les premières expériences en utilisant le prototype / This PhD thesis is dedicated to the control strategies for intelligent vehicle platoon in highway with the main aims of alleviating traffic congestion and improving traffic safety. After a review of the different existing automated driving systems, the vehicle longitudinal and lateral dynamic models are derived. Then, the longitudinal control and lateral control strategies are studied respectively. At first, the longitudinal control system is designed to be hierarchical with an upper level controller and a lower level controller. For the upper level controller, a safety spacing policy (SSP) is proposed. It is shown that the proposed SSP can ensure string stability, traffic flow stability and improve traffic capacity. Then, a coordinated throttle and brake fuzzy controller (lower level controller) is designed, in which a logic switch is designed to coordinate the two actuators (throttle and brake pedals). Second, for the lateral control, a multi-model fuzzy controller is designed. And a hierarchical lateral control architecture is also proposed, which can effectuate flexible switch between different lateral operations. After that, the integration of the longitudinal controller and lateral controller is also studied. Finally, the estimation of vehicle states is discussed. A Kalman-Bucy filter is designed to estimate vehicle states in lateral dynamics. Moreover, a reduced scale multi-sensor intelligent vehicle prototype is also presented. The performances of the divers control algorithms proposed in this thesis have been tested in numerical simulations, and the first step experiments with the reduced scale vehicle prototype gave encouraging results
87

[en] INTELLIGENT CONTROL STRATEGIES FOR SEVERE SLUG MITIGATION IN OIL PRODUCTION PLANTS / [pt] ESTRATÉGIAS DE CONTROLE INTELIGENTE PARA MITIGAÇÃO DE GOLFADAS SEVERAS EM SISTEMAS DE PRODUÇÃO DE PETRÓLEO

DINART DUARTE BRAGA 23 March 2018 (has links)
[pt] Um dos maiores desafios da produção de petróleo offshore é garantir um escoamento regular do reservatório até a unidade de processamento da produção. Entre os fenômenos que podem dificultar esta tarefa está o estabelecimento de um escoamento em golfadas no riser de produção, caracterizado por oscilações periódicas e de grande amplitude nas vazões do sistema, que diminuem a eficiência da planta de separação, sujeitam equipamentos a esforços cíclicos e causam graves descontroles de processo. Por esta razão, foram desenvolvidas nas últimas décadas diversas soluções que visam a evitar a formação das golfadas, ou ao menos, atenuar suas consequências. Entre as soluções mais promissoras estão os controladores que evitam a formação das golfadas através da manipulação ativa da válvula choke e os controladores que amortecem as golfadas nos vasos separadores da planta de processo. Neste trabalho, estas estratégias de controle são revisitadas sob a óptica do controle inteligente, possibilitando a obtenção de resultados fora do alcance dos controladores lineares. Além de um modelo computacional que descreve um sistema de produção do poço ao vaso separador, também foram desenvolvidos neste trabalho dois controladores inteligentes. O primeiro deles é um controlador anti-golfada de arquitetura híbrida Fuzzy-PID, que é capaz de suprimir as golfadas mesmo em sistemas desprovidos de medições submarinas e com válvula choke lenta. O segundo é um controlador amortecedor de golfadas fuzzy, otimizado por um algoritmo genético, com alta capacidade de atenuação das golfadas e capaz de manter o nível dentro de uma faixa considerada segura. Ambos os controladores são testados em diversos cenários e têm seus resultados comparados aos obtidos por controladores lineares. / [en] One of the major challenges of offshore oil production is to ensure a regular flow from the reservoir to the production processing unit. Among the phenomena that may hamper this task is the establishment of slug flow in the production riser, characterized by periodic oscillations of large amplitude in the system flow rates, which reduce the efficiency of the separation plant, subject equipment to cyclical fatigue and cause serious process instabilities. For this reason, several solutions that aim at avoiding the formation of slugs or, at least, mitigating their consequences have been developed in the last decades. Among the most promising solutions are controllers that prevent the formation of slugs by actively manipulating the choke valve and controllers that dampen the slugs in the vessels of the separation plant. In this work, these control strategies are revisited from perspective of intelligent control, allowing the obtainment of results beyond the reach of linear controllers. In addition to a computational model that comprises a production system from the well to the separation vessel, two intelligent controllers were developed in this work. One of them is a hybrid Fuzzy-PID anti-slug controller that is capable of suppressing slugs even in systems without submarine measurements available and with slow choke valve. The other one is a fuzzy slug damping controller, optimized by a genetic algorithm, with high slug attenuation capacity and able to maintain the level within a specified range. Both controllers are tested in several scenarios and have their results compared to those obtained by linear controllers.
88

Modelagem e controle fuzzy

Costa, José Luis January 2017 (has links)
Orientador: Prof. Dr. Daniel Miranda Machado / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2017. / Este trabalho têm como objetivo demonstrar a utilização da modelagem em lógica fuzzy na tomada de decisões, em particular na escolha da taxa SELIC de modo antecipado, utilizando alguns dos parâmetros que servem para a decisão pelo COPOM (Comitê de política monetária), ao final poderemos verificar que o resultado real é compatível com o resultado fuzzy, podendo portanto este tipo de modelagem ser utilizada em outras situações. Também veremos a utilização da lógica fuzzy para controle de proximidades, quando temos uma incerteza de quanto um objeto estará perto de um obstáculo, como resultado veremos através de algumas execuções do programa que será mais adequado utilizar a lógica fuzzy do que a lógica clássica. Para essas aplicações utilizaremos as linguagens de programação R e Kturtle, sendo um diferencial pois são gratuitas e possibilitam a criação de outras aplicações. Teremos antes a demostração da teoria da lógica fuzzy necessária para as aplicações propostas. / The purpose of this dissertation is to demonstrate the use of fuzzy logic modeling in decision making, particularly in the selection of the SELIC rate in advance, using some of the parameters that serve for the decision by the COPOM (Monetary Policy Committee). We verify that the actual result is compatible with the fuzzy result, so that this type of modeling can be used in other situations. We will also see the use of fuzzy logic for neighborhood control when we have an uncertainty about how much an object will be close to an obstacle, as a result we will see through some program executions that it will be more appropriate to use fuzzy logic than classical logic. For these applications we will use the programming languages R and Kturtle, being an advantage because they are free and allow the creation of other applications. We will first develop of the fuzzy logic theory required for the proposed applications.
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Sistemas de controle fuzzy neural e neural adaptativo destinados ao controle de pressão em rede de distribuição de água

Moura, Geraldo de Araújo 21 November 2016 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-05-30T13:07:14Z No. of bitstreams: 1 - Geraldo Moura -.pdf: 5891648 bytes, checksum: 9ca720ba25a16879f0da2a9a837d1f4b (MD5) / Made available in DSpace on 2017-05-30T13:07:14Z (GMT). No. of bitstreams: 1 - Geraldo Moura -.pdf: 5891648 bytes, checksum: 9ca720ba25a16879f0da2a9a837d1f4b (MD5) Previous issue date: 2016-11-21 / This work deals with pressure control in water distribution networks to promote the optimization of hydraulic loads in order to minimize water losses in the pipes and energy in the corresponding pumping system. Therefore, a neural fuzzy control system (NFCS) beyond the adaptive neural control system (ANCS) were developed. These control systems have been tested and evaluated on experimental bench. The neural fuzzy control system (NFCS) involves techniques of artificial neural network (ANN) and fuzzy logic. The adaptive neural control system (ANCS) used a ANN Perceptron type multilayer by backpropagation technique and gradient descent with Levenberg-Marquardt optimizer. The pressure control will be through the frequency inverter with frequency adjustments in real time, which will act on pump motor assembly installed in the trial bench hydraulic network. Control systems NFCS and ANCS, in this work, were confronted in order to promote a comparative analysis between controllers. The results showed that the ANCS reached a performance index greater than NFCS almost entirely. Finally it was added a logic filter to supervisory control and data acquisition system (SCADA) to make the ANCS able to alternately control the minimum pressure points from the distribution network of experimental bench. Both control systems, ANCS and NFCS were developed in programming environment LabVIEW® / Este trabalho tem como objetivo o controle de pressão em redes de distribuição de água, a fim promover a otimização das cargas hidráulicas, buscando minimizar as perdas de água nas tubulações e de energia no correspondente sistema de bombeamento. Para tanto foram elaborados um sistema de controle fuzzy neural (SCFN) e um sistema de controle neural adaptativo (SCNA). Esses sistemas de controle foram testados e avaliados em uma bancada experimental. O sistema de controle fuzzy neural (SCFN) envolve técnicas de rede neural artificial (RNA) e lógica fuzzy. O sistema de controle neural adaptativo (SCNA) utilizou uma RNA do tipo Perceptron de múltiplas camadas, através da técnica de retropropagação (backpropagation) e gradiente descendente com otimizador de Levenberg-Marquardt. O controle de pressão é realizado através do conversor de frequência, com ajustes da frequência, em tempo real (on-line), que atuará sobre conjunto motor bomba (CMB) instalado na rede hidráulica da bancada experimental. Os sistemas de controle SCFN e o SCNA, apresentados neste trabalho, foram confrontados a fim de promover uma análise comparativa entre os controladores. Os resultados demonstraram que o SCNA apresentou especificações superiores ao SCFN em quase sua totalidade. Finalmente foi acrescentado um filtro lógico ao SCADA (supervisory control system and data acquisition) para tornar o SCNA capaz de controlar alternadamente a pressão mínima dentre pontos da rede de distribuição da bancada experimental. Ambos os sistemas de controle, SCFN e SCNA foram desenvolvidos em ambiente de programação LabVIEW®.
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Aplicação da lógica fuzzy no controle da cristalização de um sistema de refrigeração por absorção com par brometo de lítio / Appication of fuzzy logic in control the crystallization of an absorption refrigeration system with pair water lithium bromide

Marques, João Erivando Soares 01 December 2010 (has links)
Made available in DSpace on 2015-05-08T15:00:02Z (GMT). No. of bitstreams: 1 parte1.pdf: 2575179 bytes, checksum: 8796ecfea1de6030d7f2f9efa941e491 (MD5) Previous issue date: 2010-12-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work presents theoretical and experimental study of a system of control for a steam generator. This system was developed to control the crystallization of a cooling system for absorption. The control system maintains the pressure generator above the zone of crystallization of diagram temperature pressure-saturated solution concentration of LiBr-water. The control is accomplished through simultaneous use of the relay and the frequency converter. The frequency converter acts in engine speed of pump firing of condenser cooling tower, while the relay operates directly into the burner of the generator, consecutively in thermal power of combustion. The control system can act in any pressure reference values above the zone of crystallization of absorption cooling system. In the control flow control techniques were used and fuzzy Modeling and control power thermal combustion, on-off control. Ten different experiments were conducted, which proved the efficiency of the system of control. / Neste trabalho apresenta-se o estudo teórico e experimental de um sistema de controle para um gerador de vapor. Este sistema foi desenvolvido para controlar a cristalização de um sistema de refrigeração por absorção. O sistema de controle mantém a pressão do gerador acima da zona de cristalização do diagrama temperatura-pressãoconcentração de solução saturadas do LiBr-água. O controle é realizado por meio do uso simultâneo do relé e o conversor de freqüência. O conversor de freqüência atua na velocidade do motor de acionamento da bomba da torre de resfriamento do condensador, enquanto o relé opera no queimador do gerador, consecutivamente na potência térmica de combustão. O sistema de controle pode atuar em quaisquer valores de referência de pressão acima da zona de cristalização do sistema de refrigeração por absorção. No controle da vazão foram utilizados técnicas de controle e modelagem Fuzzy e para controlar a potência térmica combustão, o controle on-off. Foram realizados dez experimentos diferentes, que comprovam a eficiência do sistema de controle.

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