• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.457-460
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• 1998

Recently, the research of the FPD(Flat Panel Display)which is substituted for CRT(Cathode Ray Tube) has been widely progressed. But most equipment that are used for production of FPD are expensive and we must import these equipment. Among these equipment, most important one is a auto-alignment system. In this paper, we present a high speed, high precision auto-alignment system, in which a PLD auto tuning algorithm, 1-dimensional CCD(Dcharge Coupled Device) camera, vision board, and vision data processing algorithm are included.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.32-35
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• 1997

A recent development in the Flat Panel Display(FPD) industry requires an auto-alignment system which is operated in high speed and high precision. In the FPD production process, aligning photo-mask with respect to guide mark printed in the glass should be accomplished in the accuracy of sub-micron order. So the system has high bandwidth and needs a dedicated control system which is fast and robust enough to control linear motors in precise manner. Proposed auto-alignment system structure in this presentation which consists of the master controller board, the DSP position controller board which controls 3 axis precision linear motors, the servo system and the man machine interface software. Designed and tuned under repeated experiments, the proposed system showed a reasonable performance in the aspect of rise time and steady state error.

• International Journal of Aeronautical and Space Sciences
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• 제3권1호
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• pp.86-94
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• 2002

The initial alignment of inertial platform for navigation system was considered. An adaptive filtering technique is developed for the system with unknown and varying sway disturbance. It is assumed that the random sway motion is the second order ARMA(Auto Regressive Moving Average) model and performed parameter identification for unknown parameters. Designed adaptive filter contain both a Kalman filter and a self-tuning filter. This filtering system can automatically adapt to varying environmental conditions. To verify the robustness of the filtering system, the computer simulation was performed with unknown and varying sway disturbance.

• 한국정밀공학회지
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• 제17권9호
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• pp.75-80
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• 2000

Although laser interferometer is widely accepted as a tool for measurement of motion accuracy the set-up procedure is time-consuming because of the strict requirement on alignment between laser head and optic units. This paper presents a 4-axis auto-aligning system which is useful for easy set-up of laser interferometer so as to evaluate precision of a 2-axis feeding system. This paper proposes two ideas for alignment in laser interferometer set-up: one is use of mirror and retroreflectors. and the other is taking advantage of the pre-defined movement and peculiar characteristic of retroreflecotrs. The pros and cons of the two methods are discussed. Illustrative experimental results are presented in which the developed system is applied to a XY table.

• 한국정밀공학회지
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• 제22권5호
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• pp.80-86
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• 2005

Optical performance evaluation results and an interference fringe pattern analysis of alignment errors for an optical head of a near-field receding (NFR) system are presented. The focusing unit is an optical head of a NFR system and is composed of a solid immersion lens (SIL) and an objective lens (OL). Generally, the size of the focusing unit is smaller than that of the conventional optical recording head. Hence there are difficulties to assemble the small focusing unit precisely. We composed an evaluation system with an interferometer and evaluated some focusing unit samples aligned and assembled by manual and present the obtained results. Using the conventional optical tool, Code V, a tolerance analysis of the alignment error between the SIL and the objective lens and an interference pattern analysis for the assembly error are executed. Then, through an analysis of the simulation results, the conceptual auto-alignment methodology using a neural network approach is considered.

• 한국항공우주학회지
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• 제48권12호
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• pp.987-995
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• 2020

고성능 탑재체들과 자세제어 센서들 간의 정밀정렬은 인공위성의 정확한 자세지향 및 높은 지향 안정성을 위해 필수적이다. 위성 개발사들은 조립 및 시험기간 동안 위성 정렬을 위해 데오드라이트 측정 시스템을 주로 사용한다. 데오드라이트 측정 시 시선 방향 오차, 수평축의 오차, 수직방향 인덱스 오차 그리고 수직축 오차로 인해 측정오차가 발생할 수 있다. 이러한 오차들 뿐 아니라 다수의 데오드라이트를 사용한 측정 시 발생할 수 있는 오차들을 정렬큐브 측정실험을 통해 분석하였다. 정렬큐브 측정실험을 기반으로 정렬측정 정확도를 향상시킬 수 있는 방법이 제안되었고, 측정 결과 위성의 설계 요구조건도 만족시킬 수 있었다.

• 자동차안전학회지
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• 제4권1호
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• pp.27-32
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• 2012

Recently, in order to reduce traffic accident related fatalities, increasing number of studies are conducted regarding the vehicle safety enhancement devices. But very few studies about test procedures and requirements for vehicle safety systems are being carried out. Since BSD, as one of the most important safety features, is installed on a new vehicle, its performance test method has to be evaluated. Independent factors irrelevant to the device types including collision position, vehicle speed and closing speed are used to calculate test distance away from the current vehicle. Effect of roadway geometry as radius of curvature is introduced to propose possible misjudgement of following vehicle as adjacent one. The study results would be utilized to enhance the test procedure of BSD performance.

• 한국정밀공학회지
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• 제27권2호
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• pp.70-77
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• 2010

This study proposed an auto focusing method for a multi-focus image in assembling lens modules in digital camera phones. A camera module in a camera phone is composed of a lens barrel, an IR glass, a lens mount, a PCB board and aspheric lenses. Alignment among the components is one of the important factors in product quality. Auto-focus is essential to adjust image quality of an IR glass in a lens holder, but there are two focal points in the captured image due to thickness of IR glass. So, sharpness, probability and a scale factor are defined to find desired focus from a multi-focus image. The sharpness is defined as clarity of an image. Probability and a scale factors are calculated using pattern matching with a registered image. The presented algorithm was applied to a lens assembly machine which has 5 axes, two vacuum chucks and an inspection system. The desired focus can be determined on the local maximum of the sharpness, the probability and the scale factor in the experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1793-1796
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• 2005

The auto-collimation by using theodolite has been accomplished for the straight measurement and the horizontality adjustment. But according to the procedure of auto-collimation or composition of the measurement equipment, an error of the measurement can be occurred. Therefore, this paper accomplished the research for enhancement of measurement accuracy according to measurement procedure of auto-collimation. For that, it has been compared the study of the combination of several precise measurement equipment with using of several theodolite.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.341-342
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• 2006