• Title/Summary/Keyword: Fuzzy factor

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Performance Assessment System using Fuzzy Reasoning Rule (펴지 추론 규칙을 이용한 수행 평가 시스템)

  • Kim Kwang Baek;Cho Jae Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.1 s.33
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    • pp.209-216
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    • 2005
  • Performance assessment has Problems about possibilities of assessment fault by appraisal, fairness, reliability, and validity of grading, ambiguity of grading standard, difficulty about objectivity security etc. This study proposes fuzzy Performance assessment system to solve problem of the conventional performance assessment. This Paper presented an objective and reliable performance assessment method through fuzzy reasoning, design fuzzy membership function and define fuzzy rule analyzing factor that influence in each sacred ground of performance assessment to account principle subject. Also, performance assessment item divides by formation estimation and subject estimation and designed membership function in proposed performance assessment method. Performance assessment result that is worked through fuzzy Performance assessment system can pare down burden about appraisal's fault and provide fair and reliable assessment result through grading that have correct standard and consistency to students.

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Fuzzy Controller of Three-Inertia Resonance System designed by Differential Evolution

  • Ikeda, Hidehiro;Hanamoto, Tsuyoshi
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.184-189
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    • 2014
  • In this paper, a new design method of vibration suppression controller for multi-inertia (especially, 3-ineritia) resonance systems is proposed. The controller consists of a digital fuzzy controller for speed loop and a digital PI controller for current minor loop. The three scaling factor of the fuzzy controller and two PI controller gains are determined by Differential Evolution (DE). The DE is one of optimization techniques and a kind of evolutionary computation technique. In this paper, we have applied the DE/rand/1/bin strategy to design the optimal controller parameters. Comparing with the conventional design algorithm, the proposed method is able to shorten the time of the controller design to a large extent and to obtain accurate results. Finally, we confirmed the effectiveness of the proposal method by the computer simulations.

A Study on Fuzzy Temperature Control for the Barrels of Injection Molding Machine using PC based PLC (PC 기반 PLC를 이용한 사출성형기 배럴의 퍼지 온도 제어에 관한 연구)

  • 김훈모
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.10
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    • pp.768-773
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    • 2003
  • Injection molding has been widely used for the mass production of a plastic product. With the development of the relative technique, various injection molding techniques have been developed and we could get more precise plastic product. The temperature of a melting resin is an important factor in the injection molding and this temperature has direct influence on the quality of a plastic product. In the present injection molding machine, the deriation of a temperature controlled by PID control method is within 2$^{\circ}C$ in the injection molding machine but PID control method takes too much time to stabilize after preheating and its overshoot is so big. We applied fuzzy control to alleriate the problem. In this research, we experimented the fuzzy temperature control with the usage of PC based PLC.

A Study on the Color Membership Computation Method using Fuzzy Color Model (패지 컬러 모델을 이용한 컬러의 소속 정도를 결정하는 방법에 관한 연구)

  • Kim, Dae-Won;Lee, Kwang. H.
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.262-264
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    • 2002
  • In this paper we focused on the color representation prob1em based on fuzzy set theory. The main factor is the determination or computation of color membership function and color difference formula. The mathematical formula to calculate the color difference should generate a uniform color scaling, and due to this reason we adopted a CIELAB color- space as a fundamental feature space. With the help of the CIELAB color space we created a new color model, referred to fuzzy color model, which can represent the ambiguous characteristics underlying colors. Based on the proposed color difference formula between fuzzy colors, we could obtain the membership computation method of an arbitrary color for a given color family.

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Multisensor-Based Navigation of a Mobile Robot Using a Fuzzy Inference in Dynamic Environments (동적환경에서 퍼지추론을 이용한 이동로봇의 다중센서기반의 자율주행)

  • 진태석;이장명
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.11
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    • pp.79-90
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    • 2003
  • In this paper, we propose a multisensor-based navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments using multi-ultrasonic sensor. Instead of using “sensor fusion” method which generates the trajectory of a robot based upon the environment model and sensory data, “command fusion” method by fuzzy inference is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor using fuzzy inference is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we performed simulations in PC as well as experiments with IRL-2002. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

Design of GA-Fuzzy Controller for Position Control and Anti-Swing in Container Crane (컨테이너 크레인의 위치제어 및 흔들림 억제를 위한 GA-퍼지 제어기 설계)

  • 허동렬
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.05a
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    • pp.16-21
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    • 2000
  • In this paper we design a GA-fuzzy controller for position control and anti-swing at the destination point. Applied genetic algorithm is used to complement the demerit such as the difficulty of the component selection of fuzzy controller namely scaling factor membership function and control rules. lagrange equation is used to represent the motion equation of trolley and load in order to obtain mathematical modelling. Simulation results show that the proposed control technique is superior to a conventional optimal control in destination point moving and modification.

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Design of FACTS Controller for Oscillation Damping of Power System (전력계통 동요억제를 위한 FACTS 제어기 설계)

  • Chung, M.K.;Wang, Y.P.;Chung, H.H.;Lee, J.P.;Hur, D.R.;Chung, D.I.
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.196-198
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    • 2005
  • In this paper, we design the Thyristor Controlled Series Capacitor(TCSC) supplementary controller for oscillation damping of power system. Here the supplementary controller is designed as a fuzzy logic-based precompensation approach for TCSC. This scheme is easily implemented simply by adding a fuzzy precompensator to an existing TCSC. And we optimize the fuzzy precompensator with a genetic algorithm for complements the demerit such as the difficulty of the component selection of fuzzy controller, namely, scaling factor, membership function and control rules. Simulation results show that the proposed control technique is superior to a conventional method in dynamic responses over the wide range of operating conditions and is convinced robustness and reliableness in view of structure.

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The Realization of MPPT Controller Using Fuzzy Controller for Photovoltaic System (퍼지제어기를 이용한 태양광발전시스템의 MPPT 제어기 구현)

  • Cho, Geum-Bae;Choi, Yeon-Ok;Baek, Hyung-Lae
    • Journal of the Korean Solar Energy Society
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    • v.24 no.2
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    • pp.89-96
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    • 2004
  • PV system is easy to operate and maintain than the other power generating system since it generally contains no moving parts, operates silently and requires very little maintenance. A solar cell generates DC power from sunlight whose power is different at any instance according to condition of irradiation and temperature variables. In order to improve the system utility factor and efficiency of energy conversion, it is desirable to operate the PV system at maximum power point of solar cell under different condition This paper describes the experimental results of the PV system contain solar modules and a DC-DC converter(boost type chopper) using fuzzy controller. The experimental results show that the PV system always operates at maximum power point of solar cells having stabilized output voltage waveform with relatively small ripple component.

Fuzzy Hybrid Control of Rhino XR-2 Robot (Rhino XR-2 로보트의 퍼지 혼성 제어)

  • Byun, Dae-Yeal;Sung, Hong-Suk;Lee, Kwae-Hi
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.299-303
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    • 1993
  • There can be two methods in control systems: one is to use a linear controller, the other is to use a nonlinear controller. The PID controller and the fuzzy controller can be said to belong the linear and the nonlinear controller respectively. In this paper, a new hybrid controller which is consist of the linear PID controller of which the gain is tuned and the nonlinear self tuning fuzzy controller is proposed. In the PID controller, an algorithm which parameterizes the proportional, the intergral, and the derivative gain as a single parameter is used to improve the performance of the PID controller. In the self tuning fuzzy controller, an algorithm which changes the shape of the triangle membership function and changes the scaling factor which is multiplied to the error and the error change. The evaluation of the performance of the suggested algorithm is carried on by the simulation for the Rhino XH-2 robot manipulator with 5 links revolute joints.

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A Study on the Fuzzy Demand Control Technique (퍼지 디맨드 예측제어기법 연구)

  • Seong, Ki-Chul;Yoon, Sang-Hyun;Kang, Min-Kyu;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.169-171
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    • 1999
  • This paper presents a new demand control technique using fuzzy logic. Generally, predictive demand control method often brings about a large number of control actions and undesirable alarm during the beginning stage of the demand period. To solve this problem, a fuzzy predictive algorithm is proposed. The main idea of the method is the determination of sensitivity factor by using fuzzy logic. The performance of the proposed algorithm is tested through a case study.

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