• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.11-14
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• 2001

원자력 발전소의 증기 발생기는 증기량과 급수량에 대한 비 최소위상 특성과 비선형성, 그리고 입력 제한 특성을 가지고 있다. 이러한 특성들은 증기 발생기의 효과적인 수위 제어에 어려움을 주고 있다. 본 논문에서는 게인 스케줄링 기법과 변형된 슬라이딩 모드 제어 기법을 이용한 원전 증기 발생기 제어기를 제안한다. 또한 앞먹임 구조를 가진 PI 제어기를 설계하여 저출력 영역에서 제안된 슬라이딩 모드 제어기와 성능을 비교한다. 모의 실험 결과 제안된 슬라이딩 모드 제어기가 최대 수위, 최소 수위, 그리고 안정화 시간 면에서 개선된 성능을 보였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.6
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• pp.505-511
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• 2015

Solid oxide fuel cell operate at high temperature ($800{\sim}1000^{\circ}C$). High temperature have an advantage of system efficiency, but a weak durability. In this study, linear state space controller is designed to handle the temperature of solid oxide fuel cell system for proper thermal management. System model is developed under simulink environment with Thermolib$^{(R)}$. Since the thermally optimal system integration improves efficiency, very complicated thermal integration approach is selected for system integration. It shows that temperature response of fuel cell stack and catalytic burner are operated at severe non-linearity. To control non-linear temperature response of SOFC system, gain scheduled linear quadratic regulator is designed. Results shows that the temperature response of stack and catalytic burner follows the command over whole ranges of operations.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1162-1170
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• 2001

This paper proposes a practical gain-scheduling control law considering robust stability and performance of Linear Parameter Varying(LPV) systems in the presence of nonlinearities and uncertainties. The proposed method introduces LMI-based pole placement synthesis and also associates with a recently developed fuzzy control system based on Takagei-Sugenos fuzzy model. The sufficient conditions for robust controller design of linearized local dynamics and robust stabilization of fuzzy control systems are reduced to a finite set of Linear Matrix inequalities(LMIs) and solved by using co-evolutionary algorithms. The proposed method is applied to the longitudinal acceleration control of high performance aircraft with linear and nonlinear simulations.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.1
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• pp.1-6
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• 2015

In this paper, a fuzzy control method is used for balancing a single-wheel robot. A single-wheel robot controlled by the PD control method becomes easily unstable since the flywheel tends to lean against one direction. In the previous research, we have used the gain scheduling method. To remedy this problem, in this paper, a fuzzy compensation technique is proposed to compensate for the balancing angle. The fuzzy control method compensates offset values at the balancing angle to prevent the gimbal from falling against one direction. Experimental studies of the balancing control performance of a single-wheel mobile robot validate the proposed control method.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.162-169
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• 2008

Dynamic characteristics of a control valve, which plays an important role in thrust control of liquid rocket engines, have been analysed by AMESim simulator modeling. A speed control method has been proposed for the control of the valve equipped with a BLDC motor and the performances of this control method have been proved in making a comparison between the predictions of simulation and experimental results. Moreover, it is shown that a control valve with a second pre-filter is enough stable to the flow disturbances. The speed control method for BLDC motor is more simpler than PI gain scheduling method for the application in complex flow system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.210-217
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• 2014

This paper presents experimental studies on controlling one-wheel robot, GYROBO. The previous one has the problem of falling down because the inside gimbal leans against one direction to make it balancing. This structural problem has been solved by redesigning the system. Gains obtained through experimental tasks are used as a gain scheduling method so that GYROBO is more stabilized. A line trajectory following control task is performed to test the driving control as well.

• Journal of the Korean Solar Energy Society
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• v.38 no.2
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• pp.1-13
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• 2018

This paper deals with the NREL (National Renewable Energy Laboratory) 5-MW reference wind turbine. The controller which include MPPT (Maximum power point tracking) control algorithm and tower load reduction control algorithm was designed by MATLAB Simulink. This paper propose a tower damper algorithm to improve the existing tower damper algorithm. To improve the existing tower damper algorithm, proposed tower damper algorithm were applied the thrust sensitivity scheduling and PI control method. The thrust sensitivity scheduling was calculated by thrust force formula which include thrust coefficient table. Power and Tower root moment DEL (Damage Equivalent Load) was set as a performance index to verify the load reduction algorithm. The simulation were performed 600 seconds under the wind conditions of the NTM (Normal Turbulence Model), TI (Turbulence Intensity)16% and 12~25m/s average wind speed. The effect of the proposed tower damper algorithm is confirmed through PSD (Power Spectral Density). The proposed tower damper algorithm reduces the fore-aft moment DEL of the tower up to 6% than the existing tower damper algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.229-236
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• 2014

In this paper, the guidance laws and controllers for the gliding guided artillery munition is studied. The gliding guided artillery munition has wings for gliding to increase a range; therefore previous guidance laws and controllers for the guided munition could not be applied. Concepts of vector field guidance and proportional navigation guidance are applied for mid-term and terminal guidance, respectively. The gliding guided artillery munition is operated within wide altitude and speed areas; therefore, the controllers are designed for each area, and gain-scheduling and the linear interpolation technique is applied to compute the appropriate gains.