• Nuclear Engineering and Technology
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• 제24권2호
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• pp.183-192
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• 1992

한국 표준 원전의 부하추종운전 능력 향상을 위하여 노심 축 방향 출력분포 제어에 기존의 regulating bank와는 별개의 heavy bank를 사용하는 노심 제어 기법인 Mode K를 제시하였다 이 경우 heavy bank는 제어할 수 있는 축방향 출력 변화의 범위가 크며, 또한 bank의 움직임과 축 방향 출력 변화가 단조적 관계를 항상 유지할 수 있으므로 운전을 용이하게 할 뿐 아니라 자동제어가 가능하도록 한다. Mode K기법을 이용한 노심 제어 자동화는 부하추종운전에 대한 운전원의 부담을 경감시킬 수 있으며, 특히 주파수 제어 운전등 미리 예측되지 않은 부하변동에 응동할 수 있는 능력을 갖게 한다. 표준 원전의 참조 발전소인 영광 3,4호기의 운전을 모의 계산함으로써 Mode K 의 설계 개념을 평가하였는데 그 결과를 통하여 한국 표준 원전의 실제적 부하추종운전을 위하여 Mode K 기법을 적절하게 사용할 수 있음을 입증하였다.

• International Journal of Ocean System Engineering
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• 제1권1호
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• pp.16-27
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• 2011

The depth and heading control of an autonomous underwater vehicle (AUV) are considered to follow the predetermined depth and heading angle. The proposed control algorithm was based on a sliding mode control, using estimated hydrodynamic coefficients. The hydrodynamic coefficients were estimated employing conventional nonlinear observer techniques, such as sliding mode observer and extended Kalman filter. Using the estimated coefficients, a sliding mode controller was constructed for a combined diving and steering maneuver. The simulated results of the proposed control system were compared with those of a control system that employed true coefficients. This paper demonstrated the proposed control system, and discusses the mechanisms that make the system stable and accurately follow the desired depth and heading angle in the presence of parameter uncertainty.

• 디지털융복합연구
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• 제12권10호
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• pp.425-431
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• 2014

본 연구는 ATOM Phantom을 이용하여 선량, 화질을 비교 분석 하여 Volume mode의 유용성 밝혀 소아 CT 검사에 적극적으로 사용하기 위함이다. Helical mode Noise와 Volume mode의 Noise, HU, SNR은 p>0.05 이므로 통계적으로 유이한 차이가 없음을 알 수 있었다. 각 부위별 선량값은 모두 p>0.05 이므로 통계적 유이한 차이가 없었으나 DLP값이 Helical mode보다 Volume mode가 더 낮게 측정되었다. 유효선량 역시 Volume mode가 Helical mode 보다 낮음을 알 수 있었다. 정성적 분석에서는 Mode에 따른 조건 별로 각각 Helical: 2.6, 3.3, 4.36 Volume: 2.8, 3.64, 4.44, Mode별 Follow up 영상평가 결과로는 Helical mode가 3.8 Volume mode가 3.83점으로 큰 차이가 없는 것으로 나타났다. 5세 이하의 소아 CT검사에 있어서 640-MDCT Volume scan이 Helical mode와 비교해 낮은 선량으로 영상의 질이 큰 차이가 없기에 소아 CT 검사에는 유용 하다고 생각된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.325-325
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• 2000

This paper proposes a modified adaptive sliding mode control which improve the performance by making the system follow the nominal trajectories controlled by nominal controller. This method is used for the system with unknown parameter uncertainty and bounded uncertainties.

• Journal of information and communication convergence engineering
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• 제2권3호
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• pp.198-201
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• 2004

In this paper, the discrete optimal control is made to have the robust property of Sliding mode controller. A augmented system with a virtual state is constructed for this objective and noble sliding surface is constructed based on this system. The sliding surface is the same as the optimal control trajectory in the original system. The states follow the optimal trajectory even if there exist uncertainties. The reaching phase problem of sliding mode control is disappear in this method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.151-154
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• 2001

This paper propose a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI. The new active common mode voltage damper is consisted of a half-bridge inverter and a common mode transformer with a blocking capacitor. Principle of the active common mode damper is as follow; by applying the compensation voltage which has the same amplitude and opposite polarity to the PWM inverter system. So, common mode voltage and high frequency leakage current can be reduced. Simulated and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.947-948
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• 2006

This paper proposes a robust posture stabilization control method for wheeled mobile robots. To solve the robust posture stabilization, we introduce reference generation mode, reference tracking mode, and reference regulation mode. In reference generation mode, a kinematic time-invariant controller is used to generate the reference trajectory which starts from the initial posture of the actual robot to the desired posture. In reference tracking mode, a sliding mode position controller is employed in such a way that the actual robot can follow the reference trajectory in the desired forward or backward moving direction, even in the presence of the disturbances in the dynamics. In reference regulation mode, a sliding mode heading direction controller is used such that the actual robot can maintain the desired posture against the disturbances. In this way, robust posture stabilization can be achieved at almost all global regions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.225-225
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• 2000

We propose the hybrid robust controller for TDC(Time Delay Control) and SMC(Sliding Mode Control) method. TDC and SMC deal with the time-varying system parameters, unknown dynamics and unexpected disturbance. This controller is applied to follow the desired reference model for the uncertain time-varying overhead crane. The control performance is evaluated through simulation. The theoretical results indicate That the proposed controller shows excellent performance to an overhead crane with the uncertain time-varying parameters and disturbance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.22.4-22
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• 2001

In this paper, the discrete optimal control is made to have the robust property of sliding mode controller. A augmented system with a virtual state is constructed for this objective and noble sliding surface is constructed based on this system. The sliding surface is the same as the optimal control trajectory in the original system. The states follow the optimal trajectory even if there exist uncertainties. The reaching phase problem of sliding mode control is desappear in this method.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.134-137
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• 2017

Follow-me function of drones is new and attractive for selfie drone users, where the drone autonomously follows and capture the user. Currently the products use the difference between GPS's in the drone and user side mobile GCS, but the targeting accuracy is not satisfactory owing to the low accuracy of GPS data, often the order of ten meters. We designed a new follow-me mode algorithm that utilizes the accuracy of visual tracking algorithm and the reliability of GPS-based. The experiment shows that proposed follow-me can capture much accurately the target user in the center of video content than GPS-only methods, and recover the vision algorithm failure quickly in 5-10 seconds.