• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.40.6-40
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• 2001

Fuzzy controls are widely used in industrial fields using experts knowledge base for its high degree of performance. Genetic Algorithm(GA) is one of the numerical method that has an advantage of optimization. In this paper, we present an acquisition method of fuzzy rules using genetic algorithm. Knowledge of the system is the key to generating the control rules. As these rules, a system can be more stable and it reaches the control goal the faster. To get the optimal fuzzy control rules and the membership functions, we use the GA instead of the experts knowledge base. Information of the system is coded the chromosome with suitable phenotype. Then, it is operated by genetic operator, and evaluated by evaluation function. Passing by the decoding process with the fittest chromosome, the genetic algorithm can tune the fuzzy rules and the membership functions automatically ...

• Journal of the Korean Society for Precision Engineering
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• v.24 no.3 s.192
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• pp.140-146
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• 2007

To understand adhesive phenomena, we need to get force curve between two surfaces. And it is said that high stiffness force analysis system is needed to get precise force curve and more information of the surfaces. Usually the stiffness of the force measurement system is under the order of 10N/m. The stiffer force measurement system, however, results in more information on the surface, because higher stiffness lead to the wider range of force curves, secondly because the force curve obtained through the stiffer one describes more precise relationship between relative tip-sample separation and interaction force. In this paper, considering for stiffness and resolution, the cantilever was designed and we made adhesion force measurement apparatus with high stiffness and high resolution, so we measured adhesive force between Ag-ball and wafer.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2624-2626
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• 2000

The stabilization controls of coupled tank system and ball-beam system are difficult control tasks because of their high order time delay, nonlinearity and structural unstability. Fuhermore, a series of classical methods such as a conventional PID and a full state feedback controller(FSFC) based on the local linearizations have narrow stabilizable regions. Therefore, in this paper, in order to stabilize two representative nonlinear system mentioned above, a Sliding Mode Controller based on a Real Variable Elitist Genetic Algorithm(RVEGA SMC) was proposed.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.505-507
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• 1998

In this paper, a simple hierarchical fuzzy inference system using structured Takagi-Sugeno type fuzzy inference units(SFIUs) is proposed. The number of fuzzy rules of the proposed HFIS is minimum in the sense of that only the number of partitions of each system variables, not of intermediate outputs of layered fuzzy controllers, are concerned. And resulted number of fuzzy rules is a summation of partition in each system variables. Gradient descent algorithm is used for adaptation of fuzzy rules. The ball and beam control is performed in computer simulation to illustrate the performance of the proposed controller.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.630-632
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• 1997

A fuzzy controller is based on o fuzzy logic that is so effective to represent uncertain phenomena of real world end mote its approximation. In this paper, A fuzzy controller which equipped with adaptive control algorithm is described. Proposed fuzzy controller applied to a boll on boon system shows a good performance.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.5
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• pp.598-603
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• 2007

To solve the rule explosion problem in multi-input fuzzy system, a method of converting a given fuzzy system to 2 layered hierarchical fuzzy system has been reported, where at the 1st layer, linearly independent fuzzy rule vectors generated from the given fuzzy system are used and, at the 2nd layer, linear combinations of these independent fuzzy rule vectors are used. In this paper, the steapest descent algorithm is presented to learn the fuzzy rule vectors and related coefficients for the equivalent 2 layered hierarchical structure. By simulation of learning of ball and beam control system, the feasibility of proposed learning scheme is shown.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.55-56
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• 2008

본 연구에서는 볼빔 시스템 제어에 대해 particle swarm optimization을 이용한 최적 퍼지 cascade 제어기 설계 방법을 소개한다. 볼빔 시스템은 모터, 빔과 움직이는 볼로 구성되며 볼의 위치를 제어하는 시스템이다. 본 논문에서는 많은 분야에서 제어 성능이 우수한 퍼지제어기를 cascade 형식으로 설계하여 볼빔 시스템을 제어한다. 퍼지 cascade 제어구조는 1차 제어기와 2차 제어기로 구성되어 있다. 최적 퍼지 제어기를 설계하기 위하여 PSO를 사용한다. PSO는 초기값에 영향이 석고 일반적인 탐색알고리즘과 달리 조기 수렴의 문제점을 극복한다. 본 논문에서 퍼지 제어기와 기존의 PB 제어기의 성능을 비교 분석한다.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.121-126
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• 2002

WC/C multilayered films were deposited by arc ion plating and magnetron sputter hybrid system with various $C_2$H$_2$ flow rates and bias voltages. The coatings have been characterized with respect to their chemical composition (Glow Discharge Optical Emission Spectroscopy), hardness(Knoop micro-hardness), residual stress(Laser beam bending) and friction coefficient(Ball on disc type wear test). Deposition rate, microhardness and residual stress of WC/C films were observed to increase with increasing the $C_2$$H_2$ flow rates. The highest hardness and residual stress were measured to be 26.5 GPa and 1.1GPa for, WC/C film deposited at substrate bias of -100V. WC/C multilayered film was obtained very low friction coefficient(~0.1).

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1948-1949
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• 2011

본 논문은 볼빔시스템 제어에 대해 입자군집최적화(Particle Swarm Optimization; PSO)을 이용한 최적 퍼지제어기 설계방법을 연구한다. 볼빔 시스템은 모터와 빔, 움직이는 볼로 구성되며 볼의 위치제어를 기본 동작으로 한다. 본 논문에서는 제어성능이 우수한 퍼지제어기를 사용하여 제어시스템을 설계하는데, 퍼지제어구조는 1차 제어기와 2차 제어기로 구성되고, 최적 퍼지제어기 설계를 위해 PSO를 사용하며 PSO는 초기값에 영향이 적고 일반적인 탐색알고리즘과 달리 초기 수렴의 문제를 극복한다. 본 논문에서는 퍼지제어기와 기존의 PD 제어기의 성능비교를 시도 하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.65-66
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• 2015

슬라이딩 모드 제어는 모델의 불확실성과 파라미터 변동, 외란으로부터 자유로운 강인제어의 한 방법으로 설계가 용이하고 트래킹 퍼포먼스가 우수하여 널리 쓰이는 제어 방법 중 하나이다. 본 논문에서는 Ball and Beam 시스템에 대해 슬라이딩 모드 제어기를 설계하고 제어시스템을 구현하였다. 매트랩을 활용한 시뮬레이션을 통해 그 제어기의 성능을 검증하였다.