• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.2
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• pp.83-92
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• 1989

This paper presents a load frequency control by optimal linear tracking, which can be well adapted to practical power systems with successive load disturbances. Conventional Load Frequency Controls (LEC's) have a feedback control scheme of the state error deviated from the post-disturbance steady state. This requires the modification of reference everytime the system encounters load changes. In this study, a new feedback scheme of LEC is developed by using the optimal linear tracking method with a fixed reference. As a result, the proposed LFC, which requires no reference modification, can be efficiently applied to power systems with successive disturbances such as load changes due to the on-off operations of reclosers or feeder switches. Another feature of the proposed LFC is that it adopts an algorithm to calculate an optimal post-fault steady state with the consideration of control input changes. The proposed LFC has been tested for a 2-area power system, which shows that it can be well adapted to successive load disturbances with good frequency response.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.2
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• pp.207-216
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• 1991

In the case that the robot manipulator should respond to the variance and uncertainty of the environment in performing preforming precision tasks, it is indispensable that the robot utilizes the various sensors for intrlligence. In this paper, the robot force control method is implemented with a force/torque sensor, two personal computers, and a PUMA 560 manipulator for performing the various application tadks. The hybrid position/force control method is used to control the force and position axis separately. An interface board is designed to read the force/torque sensor output into the computer. Since the two computers should exchange the information quickly, a common memory board is designed. Before the algorithms of application tasks are developed, the basic force commands must be supplied. Thus, the MOVE-UNTIL command is used at the discrete time instant and, the MOVE-COMPLY is used at the continuous time instant for receiving the force feedback information. Using the two basic force commands, three application algorithms are developed and implemented for edge-following, insertion, and grinding tasks.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1140-1142
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• 1996

In this paper, a fixed-horizon $H_{\infty}$ tracking control (HTC) for continuous time-varying systems is proposed in state-feedback case. The solution is obtained via the dynamic game theory. From HTC, an intervalwise receding horizon $H_{\infty}$ tracking control (IHTC) for continuous periodic systems is obtained using the intervalwise strategy. The conditions under which IHTC stabilizes the closed-loop system are proposed. Under proposed stability conditions, it is shown that IHTC guarantees the $H_{\infty}$-norm bound.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.263-265
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• 2009

In order to improve the output efficiency of the PV system, we adopt maximum power point tracking(MPPT) techniques. This paper analyzes a two-mode MPPT method based on the variable step size incremental conductance method and constant voltage MPPT method. Compared with the conventional MPPT method, the proposed method can effectively improve the MPPT speed and maximize the efficiency with the irradiation and temperature changing. In this paper, a theoretical analysis is provided and feasibility of this method is proved by simulation.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.401-404
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• 2001

본 연구에서는 표면 부착형 영구자석 전동기(PMSM)의 회전자 부착 자석 변동에 따른 영향과 변동위치를 검출하는 기법에 대하여 연구하였다. 회전자 표면부착 영구자석의 변동은 사용조건에 따른 변화와 자석 단품에 의한 영향으로 구분해 볼 수 있고, 이들 변화 요인 중 제어장치에 치명적인 자석에 의한 변화를 고려하였다. 따라서 자석의 변동 현상중 고밀도 자성체의 하나인 네오드늄_보론_철 계열의 고에너지적을 갖는 자석의 산화 방지를 위한 표면 부식 등의 현상에 의한 자편의 완전 이탈을 가정하고 이와 같은 이탈현상이 발생한 경우의 현상과 일반적으로 사용되는 인크리멘탈 엔코더를 적용한 이탈 발생위치를 추적하는 방법을 보였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.496-499
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• 2006

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuate on the variations of insolation, temperature and loads. To obtain maximum power from solar cell, photovoltaic system cell power system usually requires maximum power point tracking controller. This paper propose Maximum power point tracking method using zero slope of differential value of maximum power. The power compare method traces to maximum power point rapidly but oscillate on the maximum power point largely, when quantity insolation variation is big. The power compare method is traces to maximum power point slowly but oscillate maximum point on the maximum power point smally, when quantity insolation variation is small. To solve two problem of the power compare method, designed zero slope of differential value of maximum power.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.27-32
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• 2015

A maximum power point tracking (MPPT) algorithm using fuzzy controller was considered. MPPT method was implemented based on the voltage and reference PV voltage value was obtained from Artificial Neural Network (ANN)-model of PV modules. Therefore, measuring only the PV module voltage is adequate for MPPT operation. Fuzzy controller is used to directly control dc-dc buck converter. The simulation results have been used to verify the effectiveness of the algorithm. The proposed method is compared with conventional PO(perturbation & observation), IC(Incremental Conductance) method. The nonlinearity and adaptiveness of fuzzy controller provided good performance under parameter variations such as solar irradiation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.209-212
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• 2006

This paper presents design and implementation methods of the eye-controlled mouse using the real-time tracking of the three dimensional gazing point. The proposed method is based on three dimensional data processing of eye images in the 3D world coordinates. The system hardware consists of two conventional CCD cameras for acquisition of stereoscopic image and computer for processing. And in this paper, the advantages of the proposed algorithm and test results are described.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.856-861
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• 2011

The mobile robot controller is designed to track the target and to maintain the formation at the same time. Formation control is included in mobile robot controller by extending the trajectory tracking algorithm. The dynamic model of mobile robot is used with kinematic model considering the practical physical parameters of mobile robot. The dynamic model of mobile robot transforms velocity control input of kinematic model into torque control input which is the practical control input of mobile robot. Formation controller of mobile robot is designed to satisfy Lyapunov stability by backstepping method. The designed formation controller is applied to the mobile robot for various target movements and simulated to confirm the Lyapunov stability.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1763-1764
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• 2015

사이버나이프 시스템은 독특한 형태의 정위적 방사선 치료를 수행하는 로봇 팔을 이용하는 방사선 수술 시스템으로 치료 중 환자의 호흡 등에 따른 신체의 움직임에도 1mm 이내의 오차 범위에서 정확하게 방사선을 조사해야하며, 여러 병소를 동시에 치료할 수 있다. 사이버나이프 시스템은 로봇 팔, 선형 가속기, 병소 위치 추적 장치, 방사선 조사 스케줄러와 같은 다양한 모듈들이 통합된 시스템으로, 이를 통합 제어하기 위한 주제어 시스템이 필요하다. 본 논문에서는 본 연구원에서 개발하고자 하는 사이버나이프 주제어 시스템의 설계에 관하여 기술한다.