• Title/Summary/Keyword: fuzzy logic approach

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Sensorless speed control of a Switched Reluctance Motor using intelligent controller (지능 제어기를 이용한 SRM 센서리스 속도제어에 관한 연구)

  • 최재동;김민태;오성업;황영성;김영록;성세진
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.179-183
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    • 1999
  • This paper describes a new method for indirect sensing of the rotor position in switched reluctance motors using fuzzy logic algorithm. Through a novel fuzzy algorithm, the complete SRM magnetizing characterization is first constructed, and then used to estimate the rotor position. And also, the optimized phase is selected by phase selector. To demonstrate the promise of this approach, the proposed rotor position estimation algorithm is simulated for variable speed range.

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Block and Fuzzy Techniques Based Forensic Tool for Detection and Classification of Image Forgery

  • Hashmi, Mohammad Farukh;Keskar, Avinash G.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1886-1898
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    • 2015
  • In today’s era of advanced technological developments, the threats to the authenticity and integrity of digital images, in a nutshell, the threats to the Image Forensics Research communities have also increased proportionately. This happened as even for the ‘non-expert’ forgers, the availability of image processing tools has become a cakewalk. This image forgery poses a great problem for judicial authorities in any context of trade and commerce. Block matching based image cloning detection system is widely researched over the last 2-3 decades but this was discouraged by higher computational complexity and more time requirement at the algorithm level. Thus, for reducing time need, various dimension reduction techniques have been employed. Since a single technique cannot cope up with all the transformations like addition of noise, blurring, intensity variation, etc. we employ multiple techniques to a single image. In this paper, we have used Fuzzy logic approach for decision making and getting a global response of all the techniques, since their individual outputs depend on various parameters. Experimental results have given enthusiastic elicitations as regards various transformations to the digital image. Hence this paper proposes Fuzzy based cloning detection and classification system. Experimental results have shown that our detection system achieves classification accuracy of 94.12%. Detection accuracy (DAR) while in case of 81×81 sized copied portion the maximum accuracy achieved is 99.17% as regards subjection to transformations like Blurring, Intensity Variation and Gaussian Noise Addition.

Design Fuzzy Controller for the Ball Positioning System Based on the Knowledge Acquisition and Adaptation

  • Hyeon Bae;Jung, Jae-Ryong;Kim, Sungshin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.7
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    • pp.603-610
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    • 2001
  • Industrial processes are normally operated by skilled humans who have the cumulative and logical information about the system. Fuzzy control has been investigated for many application. Intelligent control approaches based on fuzzy logic have a chance to include human thinking. This paper represents modeling approach based upon operators knowledge without mathematical model of the system and optimize the controller. The experimented system is constructed for sending a ball to the goal position using wind of two DC motors in the predefined path. A vision camera to mimic human eyes detects the ball position. The system used in this experiment could be hardly modeled by mathematical methods and ould not be easily controlled by conventional manners. The controller is designed based on the input-output data and experimental knowledge obtained by trials, and optimized under the predefined performance criterion. And this paper shows the data adaptation for changeable operating condition. When the system is driven in the abnormal condition with unconsidered noise, the new optimal operating parameters could be defined by adjusting membership functions. Thus, this technique could be applied in industrial fields.

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Integrating Fuzzy based Fault diagnosis with Constrained Model Predictive Control for Industrial Applications

  • Mani, Geetha;Sivaraman, Natarajan
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.886-889
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    • 2017
  • An active Fault Tolerant Model Predictive Control (FTMPC) using Fuzzy scheduler is developed. Fault tolerant Control (FTC) system stages are broadly classified into two namely Fault Detection and Isolation (FDI) and fault accommodation. Basically, the faults are identified by means of state estimation techniques. Then using the decision based approach it is isolated. This is usually performed using soft computing techniques. Fuzzy Decision Making (FDM) system classifies the faults. After identification and classification of the faults, the model is selected by using the information obtained from FDI. Then this model is fed into FTC in the form of MPC scheme by Takagi-Sugeno Fuzzy scheduler. The Fault tolerance is performed by switching the appropriate model for each identified faults. Thus by incorporating the fuzzy scheduled based FTC it becomes more efficient. The system will be thereafter able to detect the faults, isolate it and also able to accommodate the faults in the sensors and actuators of the Continuous Stirred Tank Reactor (CSTR) process while the conventional MPC does not have the ability to perform it.

A Fuzzy Controller for Robust Control of Induction Motor Drive System (유도전동기 드라이브 시스템의 강인성 제어를 위한 퍼지 제어기)

  • 정동화
    • Journal of the Korean Society of Safety
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    • v.14 no.4
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    • pp.108-113
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    • 1999
  • This paper presents a study on fuzzy speed and flux controller used in a vector control of a CRPWM(Current Ragulated PWM) induction motor drive. In this paper, an approach for an easier design of the fuzzy controller is presented in order to obtain the desired value for the response time with minimal overshoot and to improve the steady state performance for speed step commands. The fuzzy controller is constructed only upon the knowledge of the motor behaviour and the desired speed response, and provides fast and robust control by reducing the effects of nonlinearities, parameter changes and load disturbance. The results of applying the fuzzy logic controller to an IM drive system are compared with those obtained by application of a conventional PI controller. The fuzzy controller provided a better response than the PI controller.

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H-infinity Discrete Time Fuzzy Controller Design Based on Bilinear Matrix Inequality

  • Chen M.;Feng G.;Zhou S.S.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.2
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    • pp.127-137
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    • 2006
  • This paper presents an $H_{\infty}$ controller synthesis method for discrete time fuzzy dynamic systems based on a piecewise smooth Lyapunov function. The basic idea of the proposed approach is to construct controllers for the fuzzy dynamic systems in such a way that a Piecewise smooth Lyapunov function can be used to establish the global stability with $H_{\infty}$ performance of the resulting closed loop fuzzy control systems. It is shown that the control laws can be obtained by solving a set of Bilinear Matrix Inequalities (BMIs). An example is given to illustrate the application of the proposed method.

Fuzzy Classification Rule Learning by Decision Tree Induction

  • Lee, Keon-Myung;Kim, Hak-Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.44-51
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    • 2003
  • Knowledge acquisition is a bottleneck in knowledge-based system implementation. Decision tree induction is a useful machine learning approach for extracting classification knowledge from a set of training examples. Many real-world data contain fuzziness due to observation error, uncertainty, subjective judgement, and so on. To cope with this problem of real-world data, there have been some works on fuzzy classification rule learning. This paper makes a survey for the kinds of fuzzy classification rules. In addition, it presents a fuzzy classification rule learning method based on decision tree induction, and shows some experiment results for the method.

An Overview of Unsupervised and Semi-Supervised Fuzzy Kernel Clustering

  • Frigui, Hichem;Bchir, Ouiem;Baili, Naouel
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.4
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    • pp.254-268
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    • 2013
  • For real-world clustering tasks, the input data is typically not easily separable due to the highly complex data structure or when clusters vary in size, density and shape. Kernel-based clustering has proven to be an effective approach to partition such data. In this paper, we provide an overview of several fuzzy kernel clustering algorithms. We focus on methods that optimize an fuzzy C-mean-type objective function. We highlight the advantages and disadvantages of each method. In addition to the completely unsupervised algorithms, we also provide an overview of some semi-supervised fuzzy kernel clustering algorithms. These algorithms use partial supervision information to guide the optimization process and avoid local minima. We also provide an overview of the different approaches that have been used to extend kernel clustering to handle very large data sets.

Development of Single-phase Fuzzy TPR for temperature control (온도제어를 위한 단상용 Fuzzy TPR 개발에 관한 연구)

  • Hong, Sung-Hun;Kang, Moon-Sung
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1053-1055
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    • 1996
  • This paper proposes a Fuzzy TPR having the control function to a TPR used for the conversion of electricity in industrial field. The Fuzzy TPR based on the Fuzzy Logic Control technique is composed of the parts to calculate the low-level value and the high-level value. These values are calculated by error and change in error which are refer to the look-up table. To show the usefulness of the proposed Fuzzy TPR, it is applied to industrial temperature control system. In the results of experiment, we see that the system is able to fast reach steady-state, and for our approach to be robust to external disturbance than the method using the conventional TPR.

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A Generalized Intuitionistic Fuzzy Soft Set Theoretic Approach to Decision Making Problems

  • Park, Jin-Han;Kwun, Young-Chel;Son, Mi-Jung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.11 no.2
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    • pp.71-76
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    • 2011
  • The problem of decision making under imprecise environments are widely spread in real life decision situations. We present a method of object recognition from imprecise multi observer data, which extends the work of Roy and Maji [J Compu. Appl. Math. 203(2007) 412-418] to generalized intuitionistic fuzzy soft set theory. The method involves the construction of a comparison table from a generalized intuitionistic fuzzy soft set in a parametric sense for decision making.