• 전기학회논문지
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• 제67권11호
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• pp.1555-1561
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• 2018

Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

• 한국안광학회지
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• 제20권2호
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• pp.133-140
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• 2015

목적: 본 연구에서는 축 안정화 디자인이 상이한 두 토릭소프트콘택트렌즈의 회전축과 회전량이 자세와 응시방향에 따라 달라지는 지를 알아보았다. 방법: 20~30대 52안을 대상으로, Lo-Torque$^{TM}$디자인 및 ASD 디자인(accelerated stabilized design) 토릭소프트콘택트렌즈를 피팅한 후 정면을 포함한 5가지 응시방향과 누운 자세에서의 회전량을 측정하였다. 결과: 정자세에서 정면 및 수직방향 응시 시 Lo-Torque$^{TM}$ 디자인 렌즈는 코쪽, ASD 디자인 렌즈는 귀쪽으로 회전하는 비율이 높은 것으로 나타났다. 수평방향 응시시에는 두 렌즈 모두 응시방향과 반대로 축회전이 일어났다. 위쪽을 응시할 때의 회전량이 가장 작았으며 코쪽을 응시할 때의 회전량이 가장 많았다. $5^{\circ}$ 이내의 회전량을 보인 경우는 정면과 수직방향을 응시할 때의 Lo-Torque$^{TM}$ 디자인 렌즈에서 더 많았으며, 수평방향 응시 시에는 ASD 디자인 렌즈에서 더 많았다. 또한, 누운 직후에는 Lo-Torque$^{TM}$ 디자인 렌즈의 회전량이 더 적었으나 1분 후에는 ASD 디자인 렌즈의 회전량이 더 적었다. 결론: 본 연구에서는 토릭소프트콘택트렌즈 착용 후 응시방향 및 자세에 의해 유발되는 축회전이 축 안정화 디자인에 따라 달라짐을 확인하였다.

• 전기학회논문지
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• 제60권12호
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• pp.2386-2391
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• 2011

Tracking and detecting targets by the millimeter wave seeker is affected by moving of platform. In order to perform the tracking performance, stabilization of a millimeter wave seeker which consists of 2-axis gimbals was considered in this study. The feasibility of the analysis and the 2-axis gimbal servo system modeling design were verified along with some simulation results.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.470-477
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• 2022

EOTS for drones is showing another aspect of market expansion in detection and recognition areas previously occupied by artificial satellites. The two-axis EOTS for drones controls the vibration or disturbance caused by the drone during the mission so that EOTS can accurately recognize the goal. Vibration generated by drones is transmitted to EOTS. Therefore, it is essential to develop a stabilization controller that attenuates vibrations transmitted from drones so that EOTS can maintain the viewing angle. Therefore, it is necessary to standardize drone disturbance and secure the performance of EOTS disturbance attenuation controller optimized for disturbance level through this. In this paper, a method of standardizing drone disturbance applied to EOTS is studied, through which EOTS controller simulation is performed and stabilization controller shape is selected and designed.

• 한국소음진동공학회논문집
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• 제20권4호
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• pp.361-372
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• 2010

Optical image stabilization is a technique to compensate the image blurring caused by some vibrations of camera at the exposure time. Pitching and yawing of camera are sensitive to the image quality so they are usually compensated by optical image stabilization. Corresponding pitching and yawing of a camera, a lens or the image sensor is translated in two-axis direction and then the optical path of camera is adjusted. In this paper, two-axis OIS actuator for mobile camera module is suggested and designed. The actuator is a voice-coil actuator that uses the electromagnetic force of voice-coil to make compensation motions. And ball bearing is used to reduce friction force. Magnetic attractive force between magnets and yokes acts as a preload and magnet springs. Prototype actuator is fabricated to measure the friction force and to verify the feasibility of the OIS actuator with ball bearing. At last, the actuator is improved in consideration of driving force and friction force. Design of experiments is used for designing the actuator.

• 한국정보통신학회논문지
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• 제2권4호
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• pp.539-544
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• 1998

This paper presents the stabilization of a shipboard satellite antenna system. Hardware systems composing the pedestal, pedestal control unit and antenna control unit are designed and stabilization control law is obtained. A model on each control axis is derived and its parameters are estimated using a genetic algorithm, and the optimal state controller is designed based on the estimated model. An experimental result demonstrates the effectiveness of the proposed system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.367-370
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• 1991

There are many kinds of drift source in angular velocity feedback stabilization system. We discussed and analyzed the source of drift, and suggest the drift compensation method for null drift system. In this paper, the performance of drift compensators is tested and proved by real 2 axis mirror stabilization system and computer simulation.

• 항공우주시스템공학회지
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• 제7권4호
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• pp.12-17
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• 2013

Control Moment Gyroscope(CMG) is one of the most efficient momentum exchange devices for satellite attitude control and essential device for agile maneuver system. This paper presents the details of a designed Single Gimbal CMG with a constant speed momentum wheel and single axis attitude control unstable to stable. In order to keep the naturally unstable equivalent point, it should be controlling the gimbal constantly. The experimental data are compared with theoretical result and requirements are used to verify their performance specifications.

• 한국ITS학회 논문지
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• 제15권1호
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• pp.102-108
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• 2016

비행중인 드론에는 매우 다양한 주파수 성분의 진동이 발생되고, 이러한 진동 환경에서 드론에 장착된 카메라로부터 깨끗하고 안정된 영상을 획득하기 위해서는 짐발 시스템의 안정화 설계가 필요하다. 짐발 시스템은 카메라 모듈을 지지하는 구조와 외부로 부터의 진동을 차단하면서 정확한 각도를 추종하는 안정화기로 구성된다. 본 논문에서는 짐발시스템의 한 축에 대한 동역학 모델을 세우고 이에 대한 고전적인 PID제어기를 적용하여 본다. 또한 시스템에 대한 동적 모델 없이 Intelligent-PID 제어기를 설계하고, 두 제어기의 성능을 MATLAB/Simulink을 이용한 시뮬레이션으로 비교하여 본다. 이들을 통하여, Intelligent-PID 제어기는 동역학 모델을 거의 필요로 하지 않고도 설계가 가능하고, 모델의 특성이 변하여도 제어기의 파라미터를 재조정할 필요가 없이 진동을 차단하고 각도를 추종 할 수 있는 제어강인성을 보인다.

• 한국정밀공학회지
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• 제27권12호
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• pp.119-124
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• 2010

In this paper, thermal stabilization design of a new concept compact machining center has been investigated. A new concept machining center adopted a new X-axis as a NC rotary table. A New concept compact machining center is designed that spindle speed, feed rate and NC Rotary table speed are 12,000rpm, 60m/min and 110rpm each. The analysis is carried out by using FEM simulation Solidworks, CATIA and ANSYS. This paper is focused on the thermal deformation according to temperature distribution of a spindle system and feed drive system. Heat transfer analysis is performed according to heat source and atmosphere contact parts. As a result, this compact machining center is designed as a thermally stable structure.