• 대한전기학회논문지
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• 제37권7호
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• pp.427-433
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• 1988

본 논문에서는 계통을 분할하여 분할된 지역간의 경계선로에 대학 조류측정을 하여 계통을 축소하는데 근거한 계통분할 알고리즘을 제시한다. 즉 전력계통을 여러개의 종속계통으로 나누면 반그시 경계선로가 파생되는데 이 경계선로 조류를 정확히 추정할 수 있으면 각 종속계통에 대한 상태추정을 개별적으로 행할 수 있으므로 각 종속계통에 대한 경계선로 조류를 추정하는 면밀한 방법을 제시하였다. 까라서, 제시된 알고리즘을 쓰면 종속계통에서 상태추정을 개별적으로 수행할 수 있기 때문에 계산시간과 메모리 용량을 현저히 줄일 수 있다. 제시된 알고리즘을 IEEE 샘플계통에 적용하여 설계통 적용 가능성을 보였다.

• 제어로봇시스템학회논문지
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• 제22권10호
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• pp.788-796
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• 2016

Bearing and frequency measurements of TMA (Target Motion Analysis) in passive line array SONAR have lower bearing rate and frequency doppler, and are not detected or tracked continuously because of various ocean environments. This is a main reason to effect the TMA performance and it takes a long time to get TMA solutions. We propose the bearing and frequency TMA(BFTMA) using accumulative batch estimation to solve the TMA problem of line array passive SONAR. The accumulative batch estimation structure is based on MLE (Maximum Likelihood Estimation) but used accumulative measurements. The accumulative batch estimation is applied for the BFTMA with nonlinear Kalman filter to estimate the target range, speed and course. Simulation and sea data analysis were carried out to verify the performance and applicability of the proposed techniques.

• 물과 미래
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• 제27권1호
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• pp.89-99
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• 1994

현재까지 국내의 홍수예측업무는 과거에 수집된 자료집단을 이용한 변수추정에 의하여 시행되고 있으나, 최근 여러 가지 순환추정 알고리즘을 적용한 홍수예측 또는 변수추정에 관한 많은 연구가 이루어지고 있다. 본 논문은 실시간 홍수예측 및 변수추정에 관한 연구로서, 특히 강우-유출모형의 상태 및 매개변수의 동시추정에 관한 추계학적 현상을 고려하였다. 홍수예측에 관한 시스템은 $\phi$ 지수에 의한 유효강우의 산정과 지체효과를 고려한 n개의 비선형 저수지모형에 의한 홍수축적으로 구성하였다. 그리고 변수추정모형과 홍수추적 모형을 상호연계하여 변수를 포함하는 확대 상태-공간모형으로 상태 및 매개변수의 동시추정에 관한 시스템을 구성하였다. 상태-공간모형에 대한 상태 및 변수추정기법으로 GLS 추정과 MAP 추정에 대하여 비교 검토하였다. 모형의 식별을 위한 민감도 분석은 추정변수의 공분산 행렬을 사용하였다.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.174-180
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• 1996

The friction is one of the nonlinearities to be considered in the precise position control of a system which has electromechanical components. The friction has complicated nonlinear characteristics and depends on the velocity, the position and the time. The conventional fixed friction compensator and the controller based on linear control theory may cause the steady state position error or oscillation. The plant to be controlled in this study is a positioning system with a linear brushless DC motor(LBLDCM). The system behaves like a 4th-order model including the compliance and the friction. In this study, the plant model is simplified to a 2nd-order model to reduce the computation in on- line estimation. Also, to reduce the computation time, only the friction is estimated on-line while the mass and the viscous damping coefficient are fixed to the values obtained from off-line estimation. The validity of the proposed scheme is illustrated with the computer simulation and the experiment where the friction is compensated by using the estimation.

• 로봇학회논문지
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• 제11권4호
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• pp.300-309
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• 2016

This paper proposes a method for motion estimation of consecutive cameras using 3-D straight lines. The motion estimation algorithm uses two non-parallel 3-D line correspondences to quickly establish an initial guess for the relative pose of adjacent frames, which requires less correspondences than that of current approaches requiring three correspondences when using 3-D points or 3-D planes. The estimated motion is further refined by a nonlinear optimization technique with inlier correspondences for higher accuracy. Since there is no dominant line representation in 3-D space, we simulate two line representations, which can be thought as mainly adopted methods in the field, and verify one as the best choice from the simulation results. We also propose a simple but effective 3-D line fitting algorithm considering the fact that the variance arises in the projective directions thus can be reduced to 2-D fitting problem. We provide experimental results of the proposed motion estimation system comparing with state-of-the-art algorithms using an open benchmark dataset.

• 한국철도학회논문집
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• 제9권2호
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• pp.237-243
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• 2006

Deicing system is to melt frost or ice freezed in catenary line when the temperature is lower than $0^{\circ}C$ in winter. The principle of deicing system is to melt frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, we present technique for estimating deicing current and process for determination of deicing section in the conventional line. Deicing impedance is estimated using Carson-Pollaczek equation, and current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of deicing system. For the determination of the final deicing section, we verified estimated value comparing with experiment value of deicing impedance and current division ratio of catenary line and messenger line using low voltage experiment. Finally, we verified the validity of estimation technique and process using a simulated test data of real deicing system operation in the Chungju Substation, Chungbuk line.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.454-455
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• 2010

This paper surveys recent works in line impedance estimation. Inverters used in distribution system are often connected to the grid through LCL filter. Different methods are investigated for estimating the line impedance. Advantages and disadvantages with brief summary for each method are presented. Simulation results for a specified grid are shown for two main different methods and the results are compared with estimation error.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2002년도 춘계학술대회
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• pp.257-262
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• 2002

There are two methodologies to increase transport capacity of railway. The one is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. All of these is intended to increase transport capacity by improving line capacity So far, we treat line capacity as the criteria for evaluating investment alternatives or for restricting tram frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that change dynamically according to operational condition, so there is a need of new line capacity estimation system. The Purpose of this paper is to present a new line capacity estimation system based on the probability simulation and its applications.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.122-127
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• 2002

There are two methodologies to increase transport capacity of railway. The one is to invest railroad equipment or vehicles, and the other to improve operation efficiency through operation optimization. All of these is intended to increase transport capacity by improving line capacity. So far, we treat line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that change dynamically according to operational condition, so there is a need of new line capacity estimation system. The Purpose of this paper is to present a new line capacity estimation system based on the probability simulation and its applications.

• 전력전자학회논문지
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• 제5권1호
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• pp.88-94
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• 2000

본 논문에서는 벡터제어용 유도전동기에 대한 파라미터 추정기법을 제시하였다. 이 제어기법은 실제 운전시의 상태와 동일한 조건하에 추정하므로 고성능의 토크제어가 요구되는 연속공정라인과 같은 산업현장에 용이하게 적용할 수 있다. 또한 출력전압의 추정에 의해 전압센서와 측정장치 같은 부가적인 하드웨어가 필요치 않으며, 추정오차에 대한 고정자 전압의 변동을 관찰함으로써 정확하고 매우 안정적인 추정값을 얻는다. 제안된 기법의 타당성 및 유용성은 모의시험장치와 실제 현장라인의 적용을 통하여 입증하였다.