• 전기학회논문지
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• 제64권12호
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• pp.1742-1747
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• 2015

An improved transfer alignment method for a strap-down inertial navigation system (SDINS) is presented here. The alignment accuracy in conventional method is vulnerable to the data latency of a Master INS (MINS) in high maneuverable platforms. We propose a time delay compensation equation considering higher-order terms in the attitude measurement equation of the Kalman filter. The equation incorporates additional information including angular rate, angular acceleration and linear acceleration from the MINS. Simulation results show that the transfer alignment accuracy is significantly improved in the high dynamic environment by incorporating the latency compensation technique.

• 한방재활의학과학회지
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• 제20권2호
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• pp.89-99
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• 2010

Objectives : This study was designed to analyze the pattern of asymmetrical alignment. Methods : This study was carried out with the data from comprehensive medical testing. 91 subjects aged 30-39 were evaluated by full spine AP X-ray. For pelvis, innominate measurement(IM), off centering measurement(OCM), ilium shadow measurement(ISM), major axis of obturator foramen(MaF), minor axis of obturator foramen(MiF) were analyzed. Spinal curvature and height of shoulder girdle were analyzed. Results : 1. In pelvis, It. posterior-inferior and it. inflare combination pattern was 38 cases(42.8%). 2. In spinal curvature, "reverse S" curve was 45 cases(49.4%) and "reverse C" curve was 30 cases(33%). 3. In shoulder girdle, It. superior pattern was 42 cases(46.1 %) and It. superior pattern was 39 cases(42.9%). 4. In whole body analysis, It. posterior-inferior and It. inflare pelvis, "reverse S" spinal curvature and It. superior shoulder girdle combination patten was 11 cases(12.1 %). This pattern is similar to Kendall's right handedness pattern and Zink's common compensatory pattern. Conclusions : Results from this investigation showed asymmetrical alignment in 30-39 years-old adults. This results are expected to contribute to classifying the alignment pattern in clinic and systemic treatment.

• 한국정밀공학회지
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• 제20권6호
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• pp.88-95
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• 2003

This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand fur high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The geometrical relationship between PCB, cameras, and xy$\theta$ stage is derived, and analytical equations for alignment errors are also obtained. The unknown parameters including camera declining angles and etc. can be obtained by initialization process. Finally, the proposed algorithm is verified by experiments by using test bench.

• 대한기계학회논문집A
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• 제39권9호
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• pp.879-884
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• 2015

인쇄전자는 필름과 같이 유연한 웹 위에 기능성 잉크를 인쇄하여 전자소자 및 회로를 만들어내는 기술로써, 대면적 및 고속 대량 생산에 적합하며 유연소재의 전자소자를 만들어 낼 수 있는 차세대 공정기술이다. 이러한 롤투롤 인쇄전자 공정의 상용화를 위해서는 웹의 정밀 위치 측정이 요구되므로 본 연구의 선행연구를 통해 수 마이크로미터 측정 정밀도를 가진 광학 측정 시스템을 제안하였다. 하지만 선행연구의 횡 방향 측정은 웹 전체가 횡 방향으로 밀림 현상이 발생한 경우 이를 인지 할 수 없는 한계를 가지고 있다. 본 연구에서는 선행연구의 이송방향 웹 위치 측정 정밀도는 유지하며 웹의 횡 방향 위치에 따라 정렬패턴에서 반사되는 광량 차이를 이용한 웹의 횡 방향 위치 측정 시스템을 제안하였고 신뢰성을 확인하였다.

• 한국정밀공학회지
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• 제26권11호
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• pp.77-84
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• 2009

Alignment error of the BGA lithography equipment is mainly caused by the dimensional change of the BGA panel which is generated during the manufacturing processes. To minimize the alignment error, 'mark alignment' algorithm in place of 'center alignment' algorithm was proposed and the optimal solution for the algorithm was derived by simple analytic form. The developed algorithm distributes evenly the alignment error over the whole panel which was evaluated by the numerical simulation. Finally, the developed algorithm was implemented to the controller of the lithography equipment and the alignment error was measured at the fiducial mark location. From the measurement, it is also concluded that the developed alignment algorithm be effective to reduce the maximum value of alignment error.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.154-159
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• 2013

Alignment tolerance for EO/IR airborne camera using common optic is an important factor in stabilization accuracy and geo-pointing accuracy. Before airborne camera is mounted on the aircraft, defining alignment tolerance and verification of it is essential in production as well as research and development. In this paper we establish basic concept on the definition and elements of alignment tolerance for airborne camera and propose how to measure each of those elements. Components and the measurement sequence of alignment tolerance are as follows: 1) tolerance of alignment between EO and IR LOS. 2) tolerance of sensor alignment. 3) tolerance of position reporting accuracy. 4) tolerance of mount alignment

• 한국정밀공학회지
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• 제20권6호
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• pp.96-104
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• 2003

This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand for high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The centers of fiducial marks are obtained by using moment, gradient method. The first method is calculating the centroid by using first moment of blob, and the latter method is calculating the center of the circle whose equation is obtained by curve-fitting the boundaries of fiducial mark. The operating system used to implement the whole set-up is carried in Window 98 (or NT) environment. Finally we implemented this system to PCB screen printer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.80-82
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• 2007

We have developed a series of fluorinated dimethacrylate copolymers. Our work has covered the synthesized derivatives of alignment materials, characterized the pretilt angle and uniformity of liquid crystal alignment layer. The pretilt angle can be tailored by using the fluorinated copolymer. Excellent uniformity was achieved as shown in experimental results.

• 대한방사선치료학회:학술대회논문집
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• 대한방사선치료학회 2005년도 춘계학술대회 초록집
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• pp.19-22
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• 2005

방사선 종양학과에서 실시하고 있는 일일 정도관리 항목인 out put laser alignment, field size, SSD indicator 점검을 간편하고 정확하게 할 수 있도록 phantom 모양의 daily check device를 설계하고 제작하였다. 본 장치를 사용하여 4개월(2005. $2\~5$)월 동안 4대의 선형가속기 일일 정도관리에 사용한 곁과 측정과정이 편리하고 시간이 단축되어 일일점검의 효율성이 향상 되었고, 출력선량 측정은 각 장비별로 ${\pm}\;2\%$ 이내였으며 laser, field size, SSD indicator 는 ${\pm}\;1mm$ 이내의 범위에서 측정되었다. 일일 정도관리 기록을 기초로 하여 월간, 연간 정도관리의 객관적인 기초 자료로 활용할 수 있었다. 제작된 daily check device는 기존 상품화된 고가의 측정 장비를 대체 사용가능하게 함으로써 비용절감 효과가 기대되며, 향후 장치 재질의 견고성 및 가벼운 소재의 개발이 필요할 것으로 사료된다.

• 대한기계학회논문집A
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• 제36권11호
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• pp.1399-1404
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• 2012

인공위성은 우주궤도에서의 임무수행 및 작동 특성을 가지고 있기 때문에 수리 불가능한 특성을 지니고 있다. 따라서 인공위성에 사용되는 탑재체들이 정상적인 기능을 발휘하기 위해서는 정확한 조립 및 설치가 되어야 한다. 또한 극심한 발사환경과 우주환경에서 변화와 이상이 발생하지 않아야 하므로 발사환경시험, 우주환경시험 전 후로 정렬 측정이 수행되어 부품 및 시스템 레벨에서의 변화에 대한 측정이 요구되어지는 실정이다. 최근 중 대형 산업품에 대한 비접촉식 3차원 정밀 측정 장비가 개발되고 있다. 이러한 장비 중 하나인 데오도라이트 측정 시스템이 항공우주산업에 널리 활용되고 있다. 따라서 본 논문에서는 다목적실용위성의 자세제어에 사용되는 이중 추력기 모듈의 각도를 데오도라이트를 이용하여 정렬 측정 및 이에 대한 신뢰도 분석을 수행하였다.