• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.30-32
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• 2005

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and floor decreases suddenly, the robot begins slip. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. First of all, this paper shows that conventional PI control can not be applied to a wheeled robot of the light weight. Secondly, proposed fuzzy logic is applied to the Takagi-Sugeno model for the configuration of fuzzy sets. For the design of Takagi-Sugeno model and fuzzy rule, proposed algorithm uses FCM(Fuzzy c-mean clustering method) algorithm. The proposed fuzzy logic controller(FLC) is pretty useful with prevention of the slip phenomena for the controller performance in the re-adhesion control strategy.

• 전력전자학회논문지
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• 제4권6호
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• pp.531-538
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• 1999

본 논문에서는 퍼지 논리에 기초를 둔 DC-DC converter를 위한 범용 FLC는 기존의 제어기와 비교할 때, 오버슈트 문제와 파라메터 변화에 대한 민감도 면에서 향상된 성능을 나타내었다. 이러한 성능 향상은 FLC 규칙들이 다양한 동작 영역에서 각각 적합하게 설정됨으로써 소신호 응답과 대산호 응답 모두 효과적으로 동작하도록 설계되었기 때문이다. 그 적용 예로 부스터(booster)에 대한 시뮬레이션 결과는 제안된 제어 기법의 타당성을 보여주고 있다.

• 조명전기설비학회논문지
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• 제28권11호
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• pp.17-25
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• 2014

This paper proposes a novel maximum power point tracking (MPPT) system using a fuzzy logic control (FLC) algorithm for robust in-environment changing. The power available at the output of a photovoltaic (PV) cell continues to change with radiation and temperature because a solar cell exhibits nonlinear current-voltage characteristics. Therefore, the maximum power point (MPP) of PV cells varies with radiation and temperature. The MPPT methods are used in PV systems to make full utilization of the PV array output power, which depends on radiation and temperature. The conventional MPPT control methods such as constant voltage (CV), perturbation and observation (PO) and incremental conductance (IC) have been studied but these methods are problematic in that they fail to take into account the changing environment. The proposed FLC controller is based on the fuzzy control algorithm and facilitates robust control with the environmental changes. Also, the PV systems applied FLC controller is modeled by PSIM and the response characteristics of the FLC method according to environmental variations are analyzed through comparison with the performance of conventional methods. The validity of this controller is shown through response results.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권1호
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• pp.48-55
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• 2005

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and floor decreases suddenly, the robot begins slip. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. First of all, this paper shows that conventional PI control can not be applied to a wheeled robot of the light weight. Secondly, proposed fuzzy logic is applied to the Takagi-Sugeno model for the configuration of fuzzy sets. For the design of Takagi-Sugeno model and fuzzy rule, proposed algorithm uses FCM(Fuzzy c-mean clustering method) algorithm. In additionally, this algorithm adjusts the driving torque for restraining re-slip. The proposed fuzzy logic controller(FLC) is pretty useful with prevention of the slip phenomena for the controller performance in the re-adhesion control strategy, These procedures are implemented using a Pioneer 2-DXE wheeled robot parameter.

• 한국지진공학회논문집
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• 제9권2호통권42호
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• pp.37-46
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• 2005

현재까지 많은 스마트 면진시스템이 제안되었고 연구되어 왔다. 본 연구에서는 스마트 면진시스템의 면진장치와 보조감쇠 장치로서 새로운 형태의 마찰진자시스템(FPS)과 MR 감쇠기를 각각 사용한다. 퍼지로직제어기(FLC)가 고유의 견실성과 비선형 및 불확실성을 쉽게 다룰 수 있는 능력이 있기 때문에 MR 감쇠기의 감쇠력을 조절하는데 FLC를 사용한다. 또한 FLC의 성능을 최적화 하기 위해서는 유전자알고리즘(GA)을 사용한다. GA를 사용함으로써 소속함수의 형상을 조절하는 것뿐만 아니라 적절한 퍼지제어규칙을 결정할 수 있다. 이를 위하여 본 연구에서는 부분개선 유전자알고리즘을 사용하였다. 이 방법은 유전자의 특정부분을 향상시키는데 효율적이다. FPS와 MR 감쇠기의 동적거동을 표현하기 위해서는 뉴로?퍼지 모델을 사용한다. FLC의 최적설계를 위하여 본 연구에서 제안된 방법의 효율성은 여러 가지 역사지진을 사용하여 계산된 동적응답을 기초로 하여 평가한다. 예제해석결과 제안된 방법은 적절한 퍼지규칙을 찾을 수 있고 GA로 최적화된 FLC는 수동제어기 뿐만 아니라 전문가의 지식에 기반한 FLC와 전통적인 준능동제어기보다 더 좋은 성능을 발휘한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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• pp.143-153
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• 1997

At the on-line control method FLC(Fuzzy Logic Controller) is stronger to the disturbance than a classical controller and its overshoot of the initialized value is excellent. The fuzzy controller can do a proper control, though it doesn't know the mathematical model of the system or the parameter value. But to make the control rule of the fuzzy controller through an expert's experiance has a changes of the control system, the control rule is fixed, it can't adjust to the environment changes of the control system, the controller output value has a minute error and it can't convergence correctly to the desired value[1][2]. There are many ways to eliminate the minute error[3][4][5], but in this paper suggests EP-FNNIC(Fuzzy Neurla Network Intelligence Controller) intelligence controller which combines FLC with NN(Neural Network) and EP(Evolution Programming). The output characteristics of EP-FNNIC controller will be compared and analyzed with FLC. It will be showed that this EP-FN IC controller converge correctly to the desirable value without any error. The convergence speed, overshoot, rising time, error of steady state of controller of these two kinds also will be compared.

• 한국정보처리학회논문지
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• 제1권3호
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• pp.319-326
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• 1994

자동제어는 그 대상이 근사적 수식화가 가능한 선형시스템에 주로 적용되고 있다. 제어대상에 대한 수학적 모델링이 명확하게 결정되지 않는 경우에는 사람이 직접 제 어하는 수동제어를 하게 된다. 본 논문에서는 수영장과 같이 거의 전적으로 숙력가의 경험에 의존하고 있는 수동제어를 자동제어가 가능하게 FLC(Fuzzy Logic Controller) 를 구축하고, 여기서 사용되는 지식을 가장 최적의 상태로 유지하기 위해 genetic 알고리즘을 사용하여 전문가로부터 얻어온 지식을 개선한다. 또한 규칙부와 소속함수 는 동시에 수정되도록 알고리즘을 설계하여 수동제어보다 제어 성능이 향상됨을 보인 다.

• 전자공학회논문지B
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• 제33B권3호
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• pp.17-27
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• 1996

More fuzzy hardware are expected to be utilized in the future to construct fuzzy logic controllers (FLCs). It is hard to find an existing fuzzy hardware which is adopting advanced functions such as self-tuning algorithm in addition to the conventional inference calculation. That is mainly because conventional self-tuning algorithms designed to implement with some hardware circuits is required for fuzzy hardwares to have self-tuning capability. As a first step toward the feature, a novel self-tuning algorithm is proposed in this paper. Based on the search method, the main idea of the proposed algorithm is to detemine valid ranges of input variables of an FLC in order to maximize performance indices fo the control system. The performance indices are so ismple as to be realized by hardware circuit. in dadditon to the conventional scaling-factor adjustment, the algorithm adjusts offset values as well, which, in effect, modifies fuzzy rules of the FLC. To justify the performance of the proposed algorithm, a simulation study is executed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1114-1115
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• 2007

In this paper, a new speed sensorless control based on a fuzzy compensator are proposed for the interior permanent magnet synchronous motor (IPMSM) drives. The conventional proportional plus integrate(PI) control are very sensitive to step change of the command speed, parameter variations and load disturbance. To cope with these problems of the PI control, the estimated speeds are compensated by using the fuzzy logic controller (FLC). In the FLC used by the speed compensator of the IPMSM, the system control parameters are adjusted by the fuzzy rule based system, which is a logical model of the human behavior for process control. The effectiveness of algorithm is confirmed by the experiments.

• 동력기계공학회지
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• 제20권6호
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• pp.11-19
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• 2016

A variable speed refrigeration system(VSRS) has been received high attention for energy saving ability. This paper investigates effects of design factors such as membership function range and sampling time to control performances for systematical designing fuzzy logic controller of the VSRS. Some comparisons of control performance between the fuzzy and PI are conducted including comparative evaluation of robustness against noise by using computer simulations. The simulation results showed that the fuzzy is very useful design method for engineers in the industrial fields which have big noises system and deal with inherent nonlinear system like the VSRS.