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An extension of the invariance principle for switched T-S fuzzy systems

Valentino, Michele Cristina; Faria, Flávio Andrade; Oliveira, Vilma Alves de
Fonte: IEEE; European Control Association (EUCA); Zurich Publicador: IEEE; European Control Association (EUCA); Zurich
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.27%
In this work, we propose an extension of the invariance principle for switched T-S fuzzy systems using an auxiliary function V for the convex combination of the subsystems which applies to unstable subsystems. The results are given in terms of LMIs. Numerical examples illustrate the effectiveness of the proposed design methods.; CNPq Proc 142246/2010-7, 150838/2012-3 e 304985/2009-0

Genetic generation of fuzzy knowledge bases: new perspectives; Geração genética de bases de conhecimento fuzzy: novas perspectivas

Cintra, Marcos Evandro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/04/2012 EN
Relevância na Pesquisa
56.45%
This work focus on the genetic generation of fuzzy systems. One of the main contribution of this work is the proposal of the FCA-BASED method, which generates the genetic search space using the formal concept analysis theory by extracting rules from data. The experimental evaluation results of the FCA-BASED method show its robustness, producing a good trade-off between the accuracy and the interpretability of the generated models. Moreover, the FCA-BASED method presents improvements to the DOC-BASED method, a previously proposed approach, related to the reduction of the computational cost for the generation of the genetic search space. In order to tackle high dimensional datasets, we also propose the FUZZYDT method, a fuzzy version of the classic C4.5 decision tree, a highly scalable method that presents low computational cost and competitive accuracy. Due to these characteristics, FUZZYDT is used in this work as a baseline method for the experimental evaluation and comparisons of other classic and fuzzy classification methods. We also include in this work the use of the FUZZYDT method to a real world problem, the warning of the coffee rust disease in Brazilian crops. Furthermore, this work investigates the task of feature subset selection to address the dimensionality issue of fuzzy systems. To this end...

Improving the stability conditions of TS fuzzy systems with fuzzy Lyapunov functions

Faria, Flávio A.; Silva, Geraldo N.; Oliveira, Vilma A.; Cardim, Rodrigo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 10881-10886
ENG
Relevância na Pesquisa
66.35%
In this paper, the fuzzy Lyapunov function approach is considered for stabilizing continuous-time Takagi-Sugeno fuzzy systems. Previous linear matrix inequality (LMI) stability conditions are relaxed by exploring further the properties of the time derivatives of premise membership functions and by introducing a slack LMI variable into the problem formulation. The stability results are thus used in the state feedback design which is also solved in terms of LMIs. Numerical examples illustrate the efficiency of the new stabilizing conditions presented. © 2011 IFAC.

Reducing the conservatism of LMI-based stabilisation conditions for TS fuzzy systems using fuzzy Lyapunov functions

Faria, Flávio A.; Silva, Geraldo N.; Oliveira, Vilma A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1956-1969
ENG
Relevância na Pesquisa
66.43%
In this article, the fuzzy Lyapunov function approach is considered for stabilising continuous-time Takagi-Sugeno fuzzy systems. Previous linear matrix inequality (LMI) stability conditions are relaxed by exploring further the properties of the time derivatives of premise membership functions and by introducing slack LMI variables into the problem formulation. The relaxation conditions given can also be used with a class of fuzzy Lyapunov functions which also depends on the membership function first-order time-derivative. The stability results are thus extended to systems with large number of rules under membership function order relations and used to design parallel-distributed compensation (PDC) fuzzy controllers which are also solved in terms of LMIs. Numerical examples illustrate the efficiency of the new stabilising conditions presented. © 2013 Copyright Taylor and Francis Group, LLC.

A fuzzy Lyapunov function approach for stabilization and control of switched TS fuzzy systems

Faria, Flávio Andrade; Valentino, Michele C.; Oliveira, Vilma A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 4817-4834
ENG
Relevância na Pesquisa
66.29%
In this work, sufficient conditions for the existence of switching laws for stabilizing switched TS fuzzy systems via a fuzzy Lyapunov function are proposed. The conditions are found by exploring properties of the membership functions and are formulated in terms of linear matrix inequalities (LMIs). Stabilizing switching conditions with bounds on the decay rate solution and H1 performance are also obtained. Numerical examples illustrate the effectiveness of the proposed design methods.

Estrategias para controle de pragas : sistemas p-fuzzy com controle hibrido; Strategies for pests control : p-fuzzy systems with hybrid control

Luiz Rafael dos Santos
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 01/09/2008 PT
Relevância na Pesquisa
66.47%
O objetivo deste trabalho é propor um modelo utilizando Sistemas Baseados em Regras Fuzzy (SBRF) que possa controlar, do ponto de vista teórico, uma determinada espécie, considerada como praga em uma lavoura ou plantação. Faz-se primeiro uma introdução à Teoria dos Conjuntos Fuzzy, bem como aos sistemas especialistas fuzzy que utilizam regras de inferência, através do método de inferência de Mamdani e que utilizem o método de defuzzificação por centro de massa. Logo após, são abordados os conceitos de Sistemas Dinâmicos P-Fuzzy uni e bidimensionais desenvolvidos por Silva [24] e Cecconelo [7]. É proposto um novo tipo de Sistema Dinâmico P-fuzzy para modelar a dinâmica populacional, de uma espécie ou de um sistema presa-predador, que leve em conta fatores extrínsecos da(s) espécie(s) envolvida(s). Estes fatores são representados por uma Condição Ambiental, que é definida e acoplada aos Sistemas P-fuzzy usuais. Ainda, usando um controlador fuzzy propomos um sistema de controle híbrido com controladores biológicos e químicos (biocidas) em que as espécies que interagem estão sujeitas também às condições ambientais. Simulações e experimentos computacionais feitos com o auxílio da Fuzzy Logic Toolbox do software Matlab são realizados e seus resultados são comentados; The aim of this work is to propose determined model...

Controle de sistemas nebulosos Takagi-Sugeno usando relaxações LMIs; LMI relaxations for control design of Takagi-Sugeno fuzzy systems

Eduardo Stockler Tognetti
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/12/2011 PT
Relevância na Pesquisa
66.32%
A principal contribuição dessa tese é a proposta de novas condições, em termos de desigualdades matriciais lineares, para a análise de estabilidade e síntese de controladores de sistemas nebulosos Takagi-Sugeno, casos discretos e contínuos no tempo. A lei de controle considerada é por realimentação de estados, sendo que para sistemas contínuos no tempo são também projetados controladores de realimentação de saída estática e dinâmica, de ordem arbitrária. São adotados como critérios de desempenho os custos garantidos H2 e H?. As funções de Lyapunov propostas, mais gerais que as existentes na literatura, são construídas como a combinação nebulosa de funções quadráticas nos estados, polinomiais homogêneas de grau arbitrário em termos das funções de pertinência do sistema nebuloso. As funções de pertinência são modeladas em um espaço definido pelo produto Cartesiano de simplexos no mesmo instante de tempo, no caso contínuo, ou em múltiplos instantes de tempo, permitindo o projeto de controladores com memória finita de parâmetros presentes e passados, no caso discreto. Em sistemas contínuos, as variáveis premissas usadas na lei de controle podem ser escolhidas pelo projetista, de acordo com a disponibilidade ou não para implementação em tempo real...

Stability analysis of Takagi-Sugeno fuzzy systems via LMI: methodologies based on a new fuzzy Lyapunov function

Mozelli,Leonardo Amaral; Palhares,Reinaldo Martinez
Fonte: Sociedade Brasileira de Automática Publicador: Sociedade Brasileira de Automática
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
66.34%
Stability analysis of TS fuzzy systems can be much improved by resorting to fuzzy Lyapunov functions, since they are parameterized by membership functions and can better characterize the time-varying feature of these systems by means of the information regarding the first time-derivative of the membership functions. In this paper an enhanced fuzzy Lyapunov function is used to develop stability conditions that evaluate also the second time-derivative of membership functions, improving the time-varying characterization of TS systems. By using diferent strategies to consider the information regarding such derivatives and employing some numerical tools that decouple system from Lyapunov function matrices new LMI tests are developed. Numerical examples illustrate the effectiveness of those methodologies.

Sistemas p-Fuzzy modificados para dinâmicas populacionais: modelagens e simulações; Modified p-Fuzzy systems for population dynamics: modeling and simulation

Ferreira, Thiago Fernando
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
66.51%
O grande desafio da modelagem matemática é descrever fenômenos naturais para fazer previsões e tomar decisões. O uso de equações de diferenças e equações diferenciais ordinárias tem sido ferramenta essencial na modelagem de fenômenos populacionais. A viabilidade e aplicabilidade de sistemas parcialmente fuzzy (p-fuzzy) na modelagem de fenômenos descritos por equações diferenciais já foi estudada anteriormente. A proposta deste trabalho é apresentar sistemas p-fuzzy modificados (cujas funções de pertinência são alteradas por uma potencia) e sistemas p-fuzzy modificados no tempo (em que as funções de pertinência são alteradas a cada iteração, no tempo) que descrevem uma melhor aproximação às soluções determinísticas para alguns modelos de dinâmica populacional, do que os sistemas p-fuzzy sem modificações. Os sistemas p-fuzzy modificados foram obtidos numericamente por meio de programas no Matlab para determinar a potência e a função que altera as potências adequadamente, calculando o menor erro entre a solução analítica e os sistemas p-fuzzy modificados para alguns modelos de dinâmica populacional. Constatamos que o sistema p-fuzzy modificado no tempo para o modelo do controle de pragas é mais conveniente em relação ao sistema p-fuzzy sem modificações; e modificado por potência...

Induced ℓ2 control of discrete-time Takagi-Sugeno fuzzy systems with time-varying delays via dynamic output feedback; Induced l2 control of discrete-time Takagi-Sugeno fuzzy systems with time-varying delays via dynamic output feedback

Su, X.; Shi, P.; Wu, L.; Karimi, H.; Yang, R.
Fonte: IEEE; USA Publicador: IEEE; USA
Tipo: Conference paper
Publicado em //2012 EN
Relevância na Pesquisa
66.34%
This paper is concerned with analyzing a novel model transformation of discrete-time Takagi-Sugeno (T-S)fuzzy systems with time-varying delays and applying it to dynamic output feedback (DOF) controller design. A new auxiliary model is proposed by employing a new approximation for time-varying delay state, and then delay partitioning method is used to analyze the scaled small gain of this auxiliary model. A sufficient condition on discrete-time T-S fuzzy systems with time-varying delays, which guarantees the corresponding closed-loop system to be asymptotically stable and has an induced ℓ2 disturbance attenuation performance, is derived by employing the scaled small gain theorem. Then the solvability condition for the induced ℓ2 DOF control is also established, by which the DOF controller can be found by solving a set of linear matrix inequalities (LMIs).; Xiaojie Su, Peng Shi, Ligang Wu, Hamid Reza Karimi and Rongni Yang

Reliable H∞ control for discrete-time fuzzy systems with infinite-distributed delay; Reliable H infinity control for discrete-time fuzzy systems with infinite-distributed delay

Wu, Z.G.; Shi, P.; Su, H.; Chu, J.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc Publicador: IEEE-Inst Electrical Electronics Engineers Inc
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
66.29%
In this paper, the problem of reliable H∞ control is investigated for discrete-time Takagi-Sugeno (T-S) fuzzy systems with infinite-distributed delay and actuator faults. A discrete-time homogeneous Markov chain is used to represent the stochastic behavior of actuator faults. In terms of a stochastic fuzzy Lyapunov functional, a sufficient condition is proposed to ensure that the resultant closed-loop system is exponentially stable in the mean-square sense with an H∞ performance index. Based on the derived condition, the reliable H∞ control problem is solved, and an explicit expression of the desired controller is also given. The case of no failure in the actuator is also considered. A numerical example is given to demonstrate that our results are effective and less conservative.; Zheng-Guang Wu, Peng Shi, Hongye Su, and Jian Chu

A novel control design on discrete-time Takagi-Sugeno fuzzy systems with time-varying delays

Su, X.; Shi, P.; Wu, L.; Song, Y.D.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc Publicador: IEEE-Inst Electrical Electronics Engineers Inc
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
66.25%
This paper focuses on analyzing a new model transformation of discrete-time Takagi-Sugeno (T-S) fuzzy systems with time-varying delays and applying it to dynamic output feedback (DOF) controller design. A new comparison model is proposed by employing a new approximation for time-varying delay state, and then, a delay partitioning method is used to analyze the scaled small gain of this comparison model. A sufficient condition on discrete-time T-S fuzzy systems with time-varying delays, which guarantees the corresponding closed-loop system to be asymptotically stable and has an induced ℓ2 disturbance attenuation performance, is derived by employing the scaled small-gain theorem. Then, the solvability condition for the induced ℓ2 DOF control is also established, by which the DOF controller can be solved as linear matrix inequality optimization problems. Finally, examples are provided to illustrate the effectiveness of the proposed approaches.; Xiaojie Su, Peng Shi, Ligang Wu, and Yong-Duan Song

Network-based robust passive control for fuzzy systems with randomly occurring uncertainties

Wu, Z.G.; Shi, P.; Su, H.; Chu, J.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc Publicador: IEEE-Inst Electrical Electronics Engineers Inc
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
66.2%
This paper investigates the problem of robust passive control for networked fuzzy systems, where randomly occurring uncertainties, variable sampling intervals, and constant network-induced delay are taken into account. A discontinuous Lyapunov functional is introduced for the closed-loop systems, which takes full advantage of the sawtooth structure of the time-varying interval delay induced by sample-and-hold and signal transmission. A sufficient condition is proposed to ensure the closed-loop system to be robustly stochastically passive. Then, the problem of robust passive control is solved. Two examples are utilized to illustrate the advantages and effectiveness of the results that are proposed in this paper.; Zheng-Guang Wu, Peng Shi, Hongye Su, and Jian Chu

Human activity recognition based on evolving fuzzy systems

Iglesias, José Antonio; Angelov, Plamen; Ledezma, Agapito; Sanchis, Araceli
Fonte: World Scientific Publishing Company Publicador: World Scientific Publishing Company
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/article Formato: application/pdf
Publicado em //2010 ENG
Relevância na Pesquisa
66.22%
Environments equipped with intelligent sensors can be of much help if they can recognize the actions or activities of their users. If this activity recognition is done automatically, it can be very useful for different tasks such as future action prediction, remote health monitoring, or interventions. Although there are several approaches for recognizing activities, most of them do not consider the changes in how a human performs a specific activity. We present an automated approach to recognize daily activities from the sensor readings of an intelligent home environment. However, as the way to perform an activity is usually not fixed but it changes and evolves, we propose an activity recognition method based on Evolving Fuzzy Systems; This work has been partially supported by the Spanish Government under project TRA2007-67374-C02-02

Memórias associativas L-fuzzy com ênfase em memórias associativas fuzzy intervalares; L-fuzzy associative memories with an emphasis on interval-valued fuzzy associative memories

Tiago Schuster
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/01/2015 PT
Relevância na Pesquisa
56.44%
As últimas décadas têm testemunhado a emergência de uma variedade de abordagens à resolução de problemas com base na computação em reticulados como, por exemplo, as redes neurais morfológicas e os modelos neurocomputação e de raciocínio fuzzy em reticulados. Usamos aqui o termo "reticulado'' no sentido dado no trabalho seminal de Birkhoff. A teoria dos reticulados nasceu da álgebra booleana e tem um grande leque de aplicações como a análise de conceitos formais, a inteligência computacional, a teoria dos conjuntos fuzzy e a morfologia matemática (MM). A MM em reticulados completos representa a base teórica para uma série de modelos de inteligência computacional conhecidos como redes neurais morfológicas (MNNs), que incluem as memórias associativas morfológicas em tons de cinza e as memórias associativas morfológicas fuzzy (FMAMs). As últimas décadas têm testemunhado a emergência de uma variedade de abordagens à resolução de problemas com base na computação em reticulados como, por exemplo, as redes neurais morfológicas e os modelos neurocomputação e de raciocínio fuzzy em reticulados. Usamos aqui o termo "reticulado'' no sentido dado no trabalho seminal de Birkhoff. A teoria dos reticulados nasceu da álgebra booleana e tem um grande leque de aplicações como a análise de conceitos formais...

Sparse Fuzzy Systems Generation and Fuzzy Rule Interpolation: A Practical Approach

Chong, A; Gedeon, Tamas (Tom); Kovacs, Sz.; Koczy, Laszlo T.
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
66.33%
In this paper, we explore the use of a sparse fuzzy system generation technique in conjunction with simple projection-based fuzzy rule interpolation, to generate sparse fuzzy systems with relatively few rules whilst still achieving reasonable system accur

Separated antecedent and consequent learning for Takagi-Sugeno fuzzy systems

Botzheim, Janos; Lughofer, Edwin; Klement, Erich Peter; Gedeon, Tamas (Tom); Koczy, Lazlo
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
66.35%
In this paper a new algorithm for the learning of Takagi-Sugeno fuzzy systems is introduced. In the algorithm different learning techniques are applied for the antecedent and the consequent parameters of the fuzzy system. We propose a hybrid method for th

XFSL: A tool for supervised learning of fuzzy systems

Moreno Velo, Francisco José; Baturone, I.; Sánchez-Solano, Santiago; Barriga, Angel
Fonte: Conselho Superior de Investigações Científicas Publicador: Conselho Superior de Investigações Científicas
Tipo: Comunicación de congreso Formato: 301775 bytes; application/pdf
ENG
Relevância na Pesquisa
66.29%
This paper presents Xfsl, a tool for the automatic tuning of fuzzy systems using supervised learning algorithms. The tool provides a wide set of learning algorithms, which can be used to tune complex systems. An important issue is that Xfsl is integrated into the fuzzy system development environment Xfuzzy 3.0, and hence, it can be easily employed within the design flow of a fuzzy system.; This work has been partially supported by the Spanish CICYT Project TIC98-0869 and the FEDER Project 1FD97-0956-C3-02.; Peer reviewed

VLSI design of universal approximator neuro-fuzzy systems

Baturone, I.; Sánchez-Solano, Santiago; Barriga, Angel; Jiménez Fernández, Carlos Jesús; Senhadji, Raouf; López, D. R.
Fonte: Conselho Superior de Investigações Científicas Publicador: Conselho Superior de Investigações Científicas
Tipo: Comunicación de congreso Formato: 164109 bytes; application/pdf
ENG
Relevância na Pesquisa
66.34%
Neuro-fuzzy systems can theoretically solve any problem since they are universal approximators. Besides, they combine the advantages of the neuro and fuzzy paradigms. This paper describes and compares the different strategies that can be adopted to implement the learning and inference mechanisms involved in a neuro-fuzzy system. CAD tools, most of them integrated into the fuzzy system development environment Xfuzzy 2.0, have been developed to assist the designer in the implementation of neuro-fuzzy systems in FPGAs or ASICs.; This work has been partially supported by the Spanish CICYT Project TIC98-0869 and the FEDER Project 1FD97-0956-C3-02.; Peer reviewed

Design issues for the VLSI implementation of universal approximator fuzzy systems

Baturone, I.; Sánchez-Solano, Santiago; Barriga, Angel; Huertas-Díaz, J. L.
Fonte: Institute of Electrical and Electronics Engineers Publicador: Institute of Electrical and Electronics Engineers
Tipo: Comunicación de congreso Formato: 41145 bytes; application/pdf
ENG
Relevância na Pesquisa
66.29%
Comunicación presentada al "CSCC'99" celebrado en Atenas en Julio de 1999.; Several VLSI realizations of fuzzy systems have been proposed in the literature in the recent years. They employ analog or digital circuitry, offering more or less programmability, implementing different inference methods, with different types of membership functions as well as different antecedents’ connectives. This paper centers this wide design space by fixing several parameters that allow efficient VLSI implementations of programmable fuzzy systems featuring first, second and third order accurate approximation. Hardware requirements are discussed and compared from the point of view of approximation capability or precision, thus attempting to a formalization that has never been applied before to the field of fuzzy hardware.; This work has been partially supported by the Spanish CICYT Project TIC98-0869.; Peer reviewed