• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.151-156
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• 1997

본 논문은 저비용이면서 정확한 제어를 수행하는 새로운 퍼지 제어기의 VHDL 설계 및 FPGA 구현을 자동적으로 수행하는 통합 개발 환경(IDE : Integrated Development Environment)을 다룬다. 이를 위해 FLC의 자동 설계 및 구현의 전 과정을 하나의 환경 내에서 개발 가능하게 하는 퍼지 제어기 자동 설계 및 구현 시스템 (FLC Automatic Design and Implementation Station :FADIS)을 개발하였는데 이 시스템은 다음 기능을 포함한다. (1) 원하는 퍼지 제어기의 설계 파라메터를 입력받아 이로부터 FLC를 구성하는 각 모듈의 VHDL 코드를 자동적으로 생성한다. (2) 생성된 각 모듈의 VHDL 코드가 원하는 동작을 수행하는지를 Synopsys사의 VHDL Simulator상에서 시뮬레이션을 수행한다. (3) Synopsys사의 FPGA Compiler에 의해 VHDL 코드를 합성하여 FLC의 각 구성 모듈을 얻는다. (4) 합성된 모듈은 Xilinx사의 XactSTep 6.0에 의해 최적화 및 배치, 배선이 이루어진다. (5) 얻어진 Xilinx rawbit 파일은 VCC사의 r2h에 의해 C 언어의 header 파일 형태의 하드웨어 object로 변환된다. (6) 하드웨어 object를 포함하는 응용 제어 프로그램의 실행 파일을 재구성 \ulcorner 능한 FPGA 시스템 상에 다운로드한다. (7) 구현된 FLC의 동작 과정은 구현된 FLC와 제어 target 사이의 상호 통신에 의해 모니터링한다. 트럭 후진 주차 제어에 사용하는 퍼지 제어기 설계 및 구현의 전 과정을 FADIS상에서 수행하여 FADIS가 완전하게 동작하는지를 확인하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.5
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• pp.83-97
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• 1998

This paper developes an integrated environment CAD system that can design and implement an accurate and cost-effective FLC automatically. For doing this, an integrated development environment (IDE) (called FADIS; FLC Automatic Design and Implementation Station) is built by the seemless coupling of many existing. CAD tools in an attempt to the FADIS performs various functions such that (1) i~utomatically generate the VHDL components appropriate for the proposed FLC architecture from the various design parameters (2) simulate the generated VHDL code on the Synopsys's VHDL Simulator, (3) automatically compiler, (4) generate the optimized, placed, and routed rawbit files from the synthesized modules by Xilinx's XactStep 6.0, (5) translate the rawbit files into the downloadable ex- [:cution reconfigurable FPGA board (VCC's EVCI), and (7) continuously monitor the control status graphically by communicating the FLC with the controlled target via S-bus. The developed FADIS is tested for its validity by carrying out the overall procedures of designing and implementing the FLC required for the truck-backer upper control, the reduction of control execution time due to the controller's FPGA implementation is verified by comparing with other implementations.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.37-46
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• 2005

To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1183-1187
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• 1993

The objective of this study is to design a fuzzy logic controller(FLC) which controls the position of excavator's attachment a noble FLC is proposed, which is based on simple control rules while offering easy tuning of control parameters by utilizing real operation characteristics of an operator. The proposed FLC consists of two parts, the proportional controller part and the FLC part. Experiments are carried out on a test bed which is built around a commercial excavator. The controller is applied to bhe leveling of excavator's bucket tip, which is one of the main functions in an excavator's operation.

• Honam Mathematical Journal
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• v.44 no.3
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• pp.391-401
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• 2022

In this study, we investigate the explicit characterization of spherical curves using the Flc (Frenet like curve) frame in Euclidean 3-space. Firstly, the axis of curvature and the osculating sphere of a polynomial space curve are calculated using Flc frame invariants. It is then shown that the axis of curvature is on a straight line. The position vector of a spherical curve is expressed with curvatures connected to the Flc frame. Finally, a differential equation is obtained from the third order, which characterizes a spherical curve.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.386-389
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• 2008

Forming limit diagram is created by graphical illustration indicating major and minor strain. In order to provide the criterion for forming safety, FLC(forming limit curve) need to be fitted to the diagram. However, the standard method for the strain measurement and FLC plotting are not fixed yet, which results in inconvenience in digitalized analysis. In this study, new construction method for FLC was suggested in order to minimize operator dependency. For this purpose, major and minor strain were measured automatically and analyzed. Then, a second order equation is adopted to fit the FLC. Optimized by response surface method was performed to ensure particular characteristics of the FLC.

• Journal of Drive and Control
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• v.17 no.1
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• pp.44-50
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• 2020

For the requirement of accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Because of the complexity of humanoid robot dynamics, the TDC (time-delay control) is practical because it does not require a dynamic model. However, there occurs a considerable error due to discontinuous non-linearities. To solve this problem, the TDC-FLC (fuzzy logic compensator) is applied to humanoid robots. The applied controller contains three factors: a TDE (time-delay estimation) factor, a desired error dynamic factor, and FLC to suppress the TDE error. The TDC-FLC is easy to execute because it does not require complicated humanoid dynamic calculations and the heuristic fuzzy control rules are intuitive. TDC-FLC is implemented on the whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the TDC-FLC for humanoid robots.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1624-1632
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• 2009

In this study, we introduce the design methodology of an optimized Interval Type-2 fuzzy controller. The fixed MF design of type-1 based FLC leads to the difficulty of rule-based control design for representing the linguistically uncertain expression. In the Type-2 FLC as the expanded type of Type-1 FLC, we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. Type-2 FLC has a robust characteristic in the unknown system with unspecific noise when compared with Type-1 FLC. Through computer simulation as well as practical experiment, we compare their performance by applying both the optimized Type-1 and Type-2 fuzzy cascade controllers to ball and beam system. To evaluate each controller performance, we consider controller characteristic parameters such as maximum overshoot, delay time, rise time, settling time and steady-state error.

• Journal of Mechanical Science and Technology
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• v.17 no.2
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• pp.187-196
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• 2003

In this paper, a new methodology of evolutionary computations - An Adaptive Evolutionary Algorithm (AEA) is proposed. AEA uses a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner in order to take merits of two different evolutionary computations : global search capability of GA and local search capability of ES. In the reproduction procedure, the proportions of the population by GA and ES are adaptively modulated according to the fitness. AEA is used to. designing fuzzy logic controller (FLC) for a high-angle-of-attack flight system for a super-maneuverable version of F-18 aircraft. AEA is used to determine the membership functions and scaling factors of an FLC. The computer simulation results show that the FLC has met both robustness and performance requirements.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.469-476
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• 2005

To date, many viable smart base isolation systems have been proposed. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively. A fuzzy logic controller (FLC) is used to modulate the MR damper. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. Neuro-fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find appropriate fuzzy rules and the GA-optimized FLC outperforms not only a passive control strategy but also a human-designed FLC and a conventional semi-active control algorithm.