• 한국항공우주학회지
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• 제37권1호
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• pp.28-35
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• 2009

본 논문에서는 목표비행체의 궤도운동 특성과 정지궤도에 있는 추적위성의 자세운동 특성을 결합하여 목표비행체를 추적하는 것과 동시에 지상국과 항상 교신할 수 있는 자세틀을 형성할 수 있는 관계식을 유도하였다. 형성되는 자세틀을 유지하기 위해서 추적위성이 고기동 자세변환을 수행할 수 있으므로 고기동에서도 특이점을 갖지 않는 MRP 변수를 사용하였다. 또한, 여러 목표비행체에 대해 연속 추적이 가능하도록 자동으로 자세틀을 변환할 수 있는 관계식을 제시하고 시뮬레이션을 통해 자세틀 유지비행과 연속 추적 성능을 확인하였다. 본 논문에서 제시한 자세틀 유지비행은 고정밀 센서를 이용하지 않아도 지상장비를 통해 목표비행체 궤도만 제공되면 추적위성이 항상 지상과 교신하면서 목표비행체를 추적할 수 있음을 보였다.

• 제어로봇시스템학회논문지
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• 제20권12호
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• pp.1231-1237
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• 2014

본 논문에서는 축소 차수 외란 관측기를 이용하여 외란이 있는 이종 다개체 시스템을 위한 협조 추종 제어기를 제안하였다. 이를 위해 우선 주어진 제어 문제가 외란과 모델 불확실성을 가지는 시스템을 위한 강인 제어 문제로 변환 될 수 있음을 보이고 변환된 문제에 외란 관측기 기반의 동적 협조 추종 제어기를 설계하였다. 모의 실험을 통해서 제안하는 이종 다개체 시스템의 협조 추종을 성공적으로 달성함을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.498-502
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• 1986

A generalized singular linear quadratic control technique is developed to design an optimal trajectory tracking system. The output feedback control law is designed using this technique. The feedback gain matrix is synthesized to minimize tracking errors with pole placement capability to satisfy the control activity requirements. An applications to a bank-to-turn missile coordinated autopilot system design is presented.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1072-1079
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• 2014

This paper introduces a coordinated droop control for the stand-alone DC micro-grid, which is composed of photo-voltaic generator, wind power generator, engine generator, and battery storage with SOC (state of charge) management system. The operation of stand-alone DC micro-grid with the coordinated droop control was analyzed with computer simulation. Based on simulation results, a hardware simulator was built and tested to analyze the performance of proposed system. The developed simulation model and hardware simulator can be utilized to design the actual stand-alone DC micro-grid and to analyze its performance. The coordinated droop control can improve the reliability and efficiency of the stand-alone DC micro-grid.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.22-29
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• 2004

This paper studies the coordinated trajectory control of an excavator as a kind of robotic manipulators driven by hydraulic actuators. Hydraulic robot system has many non-linearity in dynamics and kinematics, and strong coupling among joints(or hydraulic cylinders). This paper proposes a combined controller frame of the adaptive robust control(ARC) and the sliding mode control(SMC) for the trajectory tracking control of the excavator to preserve the advantages of the both methods while overcoming their drawbacks, namely, asymptotic stability of adaptive system for parametric uncertainties and guaranteed transient performance of sliding mode control for both parametric uncertainties and external disturbance. The suggested control technique is applied for the tracking of a straight-line motion of end-effector of manipulators, and through computer simulations, its trajectory tracking performances and the robustness to payload variation and uncertainties are illustrated.

• 항공우주기술
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• 제10권1호
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• pp.116-121
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• 2011

나로우주센터 추적레이더가 획득한 실시간 위치 정보는 발사통제시스템에서 위치, 속도, 비행궤도 표시, 예상궤도 진입여부 및 안전을 위한 비행종료시점 판단 등의 중요한 데이터로 사용된다. 추적레이더에서 발사통제시스템으로 전송하는 표적의 위치 정보는 추적레이더 중심의 좌표값 데이터이며, 발사통제시스템에서 추적레이더로 전송하는 Slaving 데이터는 발사대 중심의 좌표값 데이터이다. 이렇듯 추적레이더와 발사통제시스템 간의 송수신 데이터는 각 시스템에 맞게 적절하게 좌표 변환이 수행되어야 한다. 본 연구에서는 나로우주센터 추적레이더 간의 상호 데이터 송수신 및 발사통제시스템과의 데이터 통신에 사용되는 각각의 좌표계 및 좌표계 간의 좌표 변환에 대해 기술하였다.

• 한국전문물리치료학회지
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• 제12권3호
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• pp.39-45
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• 2005

Tracking is an experimental paradigm that can be used to study information processing in continuous movements involving accurate, ongoing control of motor performance. The purpose of this study was to identify the effects of knee tracking performance. Six patients with hemiplegia and six age-matched controls participated in the study. The tracking test was administrated. It was composed with regular ranges of $0^{\circ}C$ to $40^{\circ}C$ and randomized range .2 to .4 Hz. Using the Mann-Whitney U test, a comparison was made between subjects who had suffered from stroke and subjects who were well coordinated. The Wilcoxon Matched Pairs Signed Ranks Test was used to compare and analyze the paretic and nonparetic sides of the stroke patients. The results of study were as follows: accuracy index of the tracking test was significantly higher on the control side than paretic and nonparetic sides. Accuracy index scores were significantly higher for nonparetic sides with stroke compared with paretic sides with stroke. This study shows tracking is impaired in paretic and nonparetic knee of subjects with stroke.

• Journal of Power Electronics
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• 제9권2호
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• pp.320-333
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• 2009

A Photovoltaic (PV) system's power output varies with the change of climate. Frequency deviations, tie line voltage swings are caused by the varying PV power when large PV power from several PV systems is fed in the utility. In this paper, to overcome these problems, a simple coordinated control method for smoothing the variations of combined PV power from multiple PV systems is proposed. Here, output power command is formed in two steps: central and local. Fuzzy control is used to produce the central smoothing output power command considering insolation, variance of insolation and absolute average of frequency deviation. In local step, a simple coordination is kept between the central power command and the local power commands by producing a common tuning factor. Power converters are used to achieve the same output power as local command power employing PI control law for each of the PV generation systems. The proposed method is compared with the method where conventional Maximum Power Point Tracking (MPPT) control is used for each of the PV systems. Simulation results show that the proposed method is effective for smoothing the output power variations and feasible to reduce the frequency deviations of the power utility.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.60-62
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• 2005

In this study, the automatic tracking algorithm tracing a human face is proposed by using YCbCr color coordinated information and its thermal properties expressed in terms of thermal indexes in an infra-red image. The facial candidates are separately estimated in CbCr color and infra-red domain, respectively with applying the morphological image processing operations and the geometrical shape measures for fitting the elliptical features of a human face. The identification of a true face is accomplished by logical 'AND' operation between the refined image in CbCr color and infra-red domain.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권9호
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• pp.577-579
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• 2005

In this study, the automatic tracking algorithm tracing a human face is proposed by using YCbCr color coordinated information and its thermal properties expressed in terms of thermal indexes in an infra-red image. The facial candidates are separately estimated in CbCr color and infra-red domain, respectively with applying the morphological image processing operations and the geometrical shape measures for fitting the elliptical features of a human face. The identification of a true face is accomplished by logical 'AND' operation between the refined image in CbCr color and infra-red domain.