• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.37-44
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• 2021

This study is implemented as a sensor-less position controller capable of multi-turn detection to replace the expensive absolute encoder used in the turret servo system. For sensor-less control, the position information of the rotor is essential. For this, a magnetic flux estimator was implemented from the mathematical model of IPMSM used in the turret servo system. The position of the rotor and the angular velocity of the rotor were obtained using the rotor magnetic flux calculated from the magnetic flux estimator. Using the zero-crossing technique, one pulse was generated for each rotation of the estimated rotor magnetic flux to measure the number of multi-turns. Simulation and experiment results confirmed the usefulness of the proposed method.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.197-199
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• 2009

본 논문에서는 매입형 영구자석 동기기 (Interior Permanent Magent Synchronous Motor)를 이용한 풍력발전 시스템에서의 효과적인 단위 전류 당 최대 토크 (Maximum Torque Per Amper) 제어를 위해 필요한 파라미터인 영구자석 회전자의 초기위치 및 동기 인덕턴스를 측정하는 방법을 보인다. IPMSM을 이용한 풍력 발전 시스템의 경우 기동 토크를 제대로 발생 시키고, 돌극성으로 나타나는 릴럭턴스 토크를 효과적으로 이용하기 위해서는 정확한 회전자의 초기위치 및 인덕턴스 값이 반드시 필요하다. 제안하는 고주파 입력 시험은 역기전력 성분이 발생하지 않아서 이때의 고정자 전류를 해석하여 모터의 회전 없이 현재의 회전자의 위치 및 인덕턴스 값을 측정할 수 있다. 실험 결과를 바탕으로 제안하는 방법의 타당성을 보인다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1865-1874
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• 2013

In this paper, a design method of speed and position estimator based on unscented Kalman filter is proposed for the no sensor control of IPMSM(Interior Permanent Magnet Synchronous Motor). The proposed method is simple more than the estimator designed with rotation axis for current measurement. Also the proposed state estimator is designed including nonlinear terms of the estimator. The controller which constructed using nonlinear back-stepping control method is operated speed and current control using the estimated speed and currents information. Through simulation, the performance of the designed estimator is compared to the estimator which is designed to synchronize d-q axis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1570-1576
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• 2000

하드디스크의 고용량화 추세에 따라 헤드의 정밀한 위치제어를 위한 큰 대역폭의 트랙추적 서보 시스템의 필요성이 대두되고 있다. 이에 작은 신호의 마찰을 제거하고 대역폭을 높이는 방법 중 하나인 2단구동기 트랙추적제어를 실시하여 큰 대역폭의 트랙 추적 서보시스템을 구성하는 방법에 대해 연구하였다. 2단구동기는 조동구동기(기존 하드디스크의 VCM)와 전단형 압전체를 부착한 미동구동기로 구성하였다. 미동구동기의 Hinge구조는 트랙 방향의 공진 주파수와 출력변위를 만족시키기 위한 구조로 설계하였다. 제어기는 notch filter와 PI 보상기를 사용하는 조동구동기와 notch filter와 PD 보상기를 사용하는 미동구동기를 다양한 구조로 구성한 것들을 비교하였다. 2단구동기는 VCM만을 사용하여 트랙 추적을 할 때보다 트랙 편심을 잘 추적하며, 기계적 공진과 VCM의 비선형성에 의해 제한된 대역폭을 개선시키는 효율적인 방법임을 확인하였다.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.98-106
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• 1997

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed position synchronizing control system is constituted with speed and synchronizing controller. The speed controller is aimed at the following to speed reference. Furthermore, it is designed to guarantee low sensitivity under some disturbance as well as robustness against model uncertainties using $H_{\infty}$technique. The synchronizing controller is designed to keep minimizing the position error using PID control law which is considered to reduce the dimension of transfer function in the control system. Especially, the proposed method can be easily conducted by controlling only slave axis speed, because it, has variable structure which is decided to master and slave axis by the sign of synchronizing error. Therfore, the master axis which is smaller influenced than another axes by disturbance can be controlled without reducing or increasing its speed for precise position synchronization. The effectiveness of the proposed method is sucessfully confirmed through many experiments.s.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.1
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• pp.46-56
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• 1991

In this paper, the variable speed control of permanent magnet synchronous motor driven by a sinus¬oidal PWM inverter based on maximum torque sensitivity is presented. The developed torque or speed control is achieved by the field orientation technique. For the field orientation, the resolver is used as the rotor positioning sensor mounted on the motor shaft without pull-out of the synchonism at any speed. To show the validity of proposed control method, the simulation and experimental results are provided. The advantages of the proposed control method are to achieve the fast current and speed responses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.506-515
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• 2015

In this paper, we propose a group playback synchronization method using adaptive synchronization delay time by the bit rate of media to synchronize a play position of streaming media between mobile smart devices. This method consists of streaming server-side and client-side synchronization algorithms based on synchronization delay time which includes connection time, control packet transmission time, streaming data buffering time, and synchronization processing time. We implement the Android media player application with synchronization support using the proposed algorithms and present the result of performance evaluation.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.82-88
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• 2009

Low costed position sensor or sensorless control method is generally used in the motor control for home appliance because of the material cost and manufacture standard restriction. In conventional sensorless method, the stator resistance and back-EMF coefficient are varied by the motor speed and load torque variation. Therefore, position error occurred when the motor is operated by sensorless control method because of these variations. In this paper, the compensation method is proposed for sensorless position error using 2 hall sensors.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.427-436
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• 2002

This paper presents an implementation of high-dynamic performance of position sensorless motion control system of Reluctance Synchronous Motor(RSM) drives for an industrial servo system with direct torque control(DTC). The problems of high-dynamic performance and maximum efficiency RSM drives controlled by DTC are saturation of stator linkage flux and nonlinear inductance characteristics with various load currents. The accurate estimation of the stator flux and torque are obtained using stator flux observer of which a saturated inductance $L_d$ and $L_q$ can be compensated by adapting from measurable the modulus of the stator current and rotor position. To obtain fast torque response and maximum torque/current with varying load current, the reference command flux is ensured by imposing $I_{ds} = I_{qs}$. This control strategy is proposed to achieve fast response and optimal efficiency for RSM drive. In order to prove rightness of the suggested control algorithm, the actual experiment carried out at $\pm$20 and $\pm$1500 rpm. The developed digitally high-performance motion control system shown good response characteristic of control results and high performance features using 1.0kW RSM which has 2.57 Ld/Lq salient ratio.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.348-351
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• 2003

항로표지(Aids to Navigation)란 빛, 형상, 색채, 전파, 음향 등으로 안전한 항로를 표시하여 선박 항행의 안전성을 확보하기 위하여 인위적으로 설치하는 시설이다. 특히, 등대(Lighthouse)는 항로표지 중 가장 중요한 것으로 선박이 육지나 주요 변침점(Turning Point) 또는 선박 위치를 확인하기 위하여 연안에 설치하거나 항만의 소재, 항구 등을 나타내기 위하여 설치한 구조물이다. 본 논문에서는 선박의 입ㆍ출항에 관련하여 선박의 안전을 위해서 설치되어 있는 등대의 효율적인 관리 및 운영을 위한 등대 동기 제어 시스템의 개발에 관한 연구이다. 이를 위해서, 등대 동기 제어 시스템은 하드웨어(컨트롤 박스)와 소프트웨어(제어 프로그램)로 나누어 구성하였다. 하드웨어 모듈은 등대와 선박의 입ㆍ출항에 관한 업무를 담당하는 관제소 사이의 인터페이스를 제공한다. 즉, 등대의 점멸등 제어를 위한 제어부와 등대와 관리 시스템사이의 데이터 전송을 위한 통신 인터페이스를 마이크로컨트롤러의 한 종류인 PIC(Programmable Interrupt Controller)를 이용하여 구성하였다. 소프트웨어 모듈은 시스템 운영자가 등대를 간편하고 효율적으로 관리하기 위해서 GUI(Graphical User Interface) 형태의 인터페이스를 제공한다.