• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.557-560
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• 2015

자동초점이란 영상을 획득하는 시스템에서 고정된 촬상면에 자동으로 초점이 맺히도록 렌즈를 구동시키는 방식으로 컴퓨터비전과 카메라 등에서 매우 중요하게 사용된다. 소형 카메라의 경우 자동초점에서 렌즈구동부인 actuator의 기술은 대량생산이 이용이하고, 위치센서가 불필요하며, 회로구성이 용이한 VCM방식이 널리 사용되고 있으며, 구동의 안정성에 비해 크기와 소음이 큰 스테핑모터 방식, 크기는 가장 작지만 납 함유문제 및 습도 취약성을 갖는 피에조 방식이 있다. 그 외에 액체렌즈방식이 있는데, 소형 구조에 저전력의 장점이 있지만 화질 및 신뢰성 검증 그리고 고압이 필요한 특징을 가지는 구조도 있다. 본 논문에서 5Mpixel급 이미지 센서를 통해 획득한 영상의 선예도를 이용하여 VCM의 actuator처럼 액체렌지를 제어하여 자동으로 초점을 맞추는 제어방식을 구현하고 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.105.5-105
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• 2002

Digital Polymer Motor (DPM) based on dielectric elastomer is presented. It includes all the supplementary parts for actuation such as micro-controller, DC-DC converter etc. DPM can be operated by itself with the program embedded and controlled via serial interface with PC. The actuator accomplishes bidirectional actuation and compliance controllability, which are important characteristics for a biomimetic artificial muscle actuator. DPM accomplish these requirements without any mechanical substitute or complicated algorithms. Its basic concepts and working principles are addressed with modeling and simulation and the compliance controllability are verified by conducting several experiments. $\textbullet$ Polymer, Dielectric, Biomimetic

• 한국공작기계학회논문집
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• 제11권5호
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• pp.65-72
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system(100mm stroke and $\pm$ l0nm positioning accuracy) with single plane X-Y stage are materialized.

• 소음진동
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• 제7권2호
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• pp.301-310
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• 1997

This paper presents active noise control method to form the near-field quiet zone for passengers in an automobile. The actuator model including interior acoustic plant, speaker and amplifier is experimentally identified in forms of auto-regressive and moving average by means of least mean square algorithm, The digital controller is composed of the regulator and Kalman filter to be designed based on LQG (linear quadratic gaussian). If the actuator model is prefiltered with digital filter to be properly designed for concentrating control performance index on the frequency band of primary noise source, LQG design approach can be effectively applied for the design of headset controller. Experimental results demonstrate that near-field quiet zone showing about 10dB noise reduction at microphone position can be formed using the headset located at passenger seat.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.740-742
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• 2005

In the past, a mobile phone had only a function of communication. Recently, new functions such as an mp3 player and a camera are added in a mobile phone. For the application of a camera module to a mobile phone, the size of the camera module needs to become smaller than a general Digital Camera. Furthermore, it is also required that the performance of the camera module in a mobile phone be the same as that of a Digital Camera. In order to fulfill these requirements, the camera module should have functions such as Auto Focus, Zoom, the shutter and the aperture. Therefore, we introduce a simple and effective actuator and propose the shutter composed of solenoid.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.39.1-39
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• 2002

We present nanoactuators and nanodetectors for high-precision Micro Electro Mechanical System (MEMS) applications. Major technical difficulties in the high-precision MEMS are arising from the fabrication uncertainty and electrical noise problems. In this paper, we present high-precision actuators and detectors, overcoming the technical limitations placed by the conventional MEMS technology. For the nano-precision actuation, we present a nonlinearly modulated digital actuator (NMDA). NMDA composed of a digital microactuator and a nonlinear micromechanical modulator. The nonlinear micromechanical modulator is intended to purify the actuation errors in the stroke of the digital a...

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.619-620
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• 2006

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.322-326
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• 1990

The solution of problems in the automation of mold manufacturing process are high speed and resolution. To catch two problems at once, digital servo system will be essential replacing the analog servo system. In this paper, we tried some hardware/software approach including, designing basic structure, modeling of servo actuator, and designing & simulating of velocity & position controller. Finally, we constructed the hardware for 1 axis digital servo controller of NC system. As a result we obtained the design technics of digital servo systems for high speed NC system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.670-674
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• 2002

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.155-159
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• 2004

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dydnamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However the research for dynamic characteristics is very deficient. In this paper, the helical suing are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidicrectional actuator was fabricated and experimented for its performance.