• Transactions on Control, Automation and Systems Engineering
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• 제2권1호
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• pp.13-18
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• 2000

In this paper, an Adaptive Evolutionary Computation(AEC) is proposed. AEC uses a genetic algorithm(GA) and an evolution strategy (ES) in an adaptive manner is order to take merits of two different evolutionary computations: global search capability of GA and local search capability of ES. In the reproduction procedure, proportions of the population by GA and ES are adaptively modulated according to the fitness. AEC is used to design the membership functions and the scaling factors of fuzzy logic controller (FLC). To evaluate the performances of the proposed FLC, we make an experiment on FLC for the speed control of an actual DC series motor system with nonlinear characteristics. Experimental results show that the proposed controller has better performance than that of PD controller.

• 전자공학회논문지SC
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• 제45권1호
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• pp.1-8
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• 2008

자유롭고 빠르게 이동할 수 있도록 도와주는 개인 이동 수단인 two-wheel balancing vehicle은 inverted pendulum 시스템의 원리를 이용한 것으로, 최근 들어 많은 연구가 이루어지고 있고 이를 이용한 제품이 실제 사용되고 있다. 본 논문에서는 일반적인 PID 제어이론을 이용한 two-wheel balancing vehicle에 대한 제어성능을 개선시키는 새로운 제어방식을 제안한다. 제안한 방식은 퍼지 PD+I 제어방식으로 향상된 PID 제어의 일종으로 2개의 입력과 1개의 출력을 가진 퍼지시스템에 적분 신호를 더함으로써 출력신호를 만든다. 퍼지시스템의 비선형성은 시간공정에서 비례신호와 미분신호의 가중치를 변화함으로써 최적의 출력제어신호를 만들어낸다. 제안한 퍼지 PD+I 제어방식의 유용성을 알아보기 위해 two-wheel balancing mobile robot에 대해 시뮬레이션과 실험의 결과를 통해, 제안한 퍼지 PD+I 제어방식이 일반적인 PID 방식보다 우수한 성능을 가지고 있음을 알 수가 있다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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• pp.283-286
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• 2003

Generally, the repeater in CDMA(Code Division Multiple Access) included HPA(HI-Power Amplifier) to amplifier communication signals. Also, HPA contained PD(Predistortor) to maintain the linearization of amplifier characteristics A configuration component of PD have been used electricity nonlinear devices such that diode. But this diode takes many influences at the circumstance temperature. Consequently, st can't maintain output linearization, and drop the communication Duality. The manufacturer set bias of the circuit to the manual at the first out of ware-house low. But the Q-point changes according to the change of the high temperature or low temperature. Therefore, we designed a system to maintain the Q-point by FDM(Fuzzy Decision Maker) in this paper.

• 한국항해학회지
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• 제5권2호
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• pp.59-88
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• 1981

Many studies have been done in the field of fuzzy logic theory, but it's application is not so much, and particularly, there isn't any application to the ship's steering system, until now. This paper is to survey the effect of application of fuzzy logic control to the ship's steering system. The controller is made up of a set of Linguistic Control Rules which are conditional linguistic statements connecting the inputs and the output, and take the inputs derived from the errors, that is, deviation angle and it's angular velocity. These two variables together give information about the state of the steering system, and the Linguistic Control Rules are implemented on the digital computer. The characteristics of this system were investigated through the computer simulation and satisfactory results compared with that of the conventional PD controller were obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.34-36
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• 2000

This paper proposes the design of SVC adaptive fuzzy logic controller(AFLC) using Tabu search and neural network. We tuned the gain of input-output variables of fuzzy logic controller and weights of neural network using Tabu search. Neural network used to tune the output gain of FLC adaptively. We have weights of neural network learned using back propagation algorithm. We performed the nonlinear simulation on an single-machine infinite system to prove the efficiency of the proposed method. The proposed AFLC showed the better performance than PD controller in terms of the settling time and damping effect, for power system operation condition.

• Journal of Power Electronics
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• 제11권4호
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• pp.393-400
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• 2011

The main objective of this paper is to control the speed of Nonlinear Hybrid Electric Vehicle (HEV) by controlling the throttle position. Various control techniques such as well known Proportional-Integral-Derivative (PID) controller in conjunction with state feedback controller (SFC) such as Pole Placement Technique (PPT), Observer Based Controller (OBC) and Linear Quadratic Regulator (LQR) Controller are designed. Some Intelligent control techniques e.g. fuzzy logic PD, Fuzzy logic PI along with Adaptive Controller such as Self Organizing Controller (SOC) is also designed. The design objective in this research paper is to provide smooth throttle movement, zero steady-state speed error, and to maintain a Selected Vehicle (SV) speed. A comparative study is carried out in order to identify the superiority of optimal control technique so as to get improved fuel economy, reduced pollution, improved driving safety and reduced manufacturing costs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.37-39
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• 2000

This paper describes the application of Fuzzy Logic Controller (FLC) to Thyristor Controlled Series Capacitor (TCSC) which can have significant impact on Power system dynamics. The function of the FLC is to control the firing angle of the TCSC. We tuned the scaling factors of the FLC using Tabu Search. The proposed FLC is used for damping the low frequency oscillations caused by disturbances such as the sudden changes of small of large loads or the outages in the generators or transmission lines. To evaluate usefulness of the proposed FLC. we performed the computer simulation for single-machine infinite system. The response of FLC is compared with that of PD controller optimized using Tabu Search. Simulation results that the FLC shows the better control performance than PD controller.

• 대한전기학회논문지:전력기술부문A
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• 제50권12호
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• pp.561-567
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• 2001

This paper describes the application of Fuzzy Logic Controller (FLC) to Thyristor Controlled Series Capacitor (TCSC) which can have significant impact on power system dynamics. The function of the FLC is to control the firing angle of the TCSC. We tuned the scaling factors of the FLC using Tabu Search. The proposed FLC is used for damping the low frequency oscillations caused by disturbances such as the sudden changes of small or large loads or the outages in the generators or transmission lines. To evaluate usefulness of the proposed FLC, we performed the computer simulation fur single-machine infinite system. The response of FLC is compared with that of PD controller optimized using Tabu Search. Simulation results that the FLC shows better control performance than PD controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.360-363
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• 1993

Fuzzy Logic Control immitating human decision making process is a novel control strategy based on expert's experience and knowledge and many process designers are developing its applications. But it is difficult to obtain a set of rules from human operator. And there is a limitation on adjusting to environmental changes. In this paper, we proposed adaptive fuzzy algorithm to overcome these difficulties using weights added to the rules. To verify the validity of this control strategy, we have implemented this algorithm for a DC servo motor with PD-type fuzzy controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2221-2223
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• 2004

본 논문에서는 유전알고리즘을 기반으로 하여 설계된 광 디스크 드라이브의 광학헤드 구동기용 퍼지 PI/PD 제어기를 제안한다. 본 논문에서 제안하는 제어기는 광디스크 드라이브의 광학헤드용 구동기의 포커싱 서보계, 트랙킹 서보계를 제어할 수 있는 퍼지 제어기이며 유전알고리즘을 통해 최적의 퍼지 규칙을 도출한다. 그리고 이를 토대로 모의실험을 수행한다.