• 제목/요약/키워드: 3D profile measurement

검색결과 122건 처리시간 0.023초

High Precision Measurement of 3D Profile Using Confocal Differential Heterodyne Interferometer

  • Kim Taejoong;Lee SeungWoo;Gweon Dae-Gab
    • Journal of the Optical Society of Korea
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    • 제9권1호
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    • pp.22-25
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    • 2005
  • The differential heterodyne interferometer (DHI) is suitable for precise measurement of step height and line width, since its differential configuration can significantly reduce disturbances from the environment [1,2]. Like most phase measuring interferometers, however, the DHI is limited, in that it can obtain only the phase from 0 to 2π, because of the sinusoidal nature of the optical interference involved. Thus, the measurable step height is limited to one quarter of the wavelength of the light source. This study describes a confocal differential heterodyne interferometer (CDHI) for measuring step heights of several micrometers, with a high resolution and line width with high repeatability. The CDHI has a simple structure and rapid measurement speed.

스테레오 카메라의 양안 시차를 이용한 거리 계측의 고속 연산 알고리즘 (An Efficient Algorithm for 3-D Range Measurement using Disparity of Stereoscopic Camera)

  • 김재한
    • 한국정보통신학회논문지
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    • 제5권6호
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    • pp.1163-1168
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    • 2001
  • 거리 계측 시스템은 물체까지의 거리를 삼차원 좌표계에서 측정하는 장치이다. 군용 장비나 건설, 항해, 검사 조립, 로봇 비전 등에 널리 사용되는 무접촉식 원격 거리 계측(ranging) 시스템은 자동화 응용에 매우 중요하다. 계측 방식은 active와 passive방식으로 구분되는데, active방식은 laser나 microwave, 초음파 등의 time of flight를 이용하거나 레이저 조사(illumination)에 대한 카메라 영상을 해석하는 등의 다양한 방식이 있으나 장치가 복잡하며, passive 방식은 stereo camera의 양안영상을 이용하거나 focus특성을 이용하는 방식 등이 있으나 대부분 연산시간이 많이 요구된다. 본 연구에서는 수동식 스테레오 카메라에서 양안시차를 산출하여 triangulation으로 목표전의 거리를 측정하는 방식에서, 연산 시간이 많이 소요되는 과정을 고속으로 처리하는 새로운 방식을 제안하였다. 즉, 목표점에서의 양안 edge 영상을 구하고, 이 영상의 projection profile을 cross correlation하여, 시차를 고속으로 산출해 거리를 구하는 알고리즘을 제안하였으며, 이 방식의 효율성을 실험 결과를 통하여 보였다.

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평행 광축에서의 위상측정 형상측정법에 관한 연구 (A Study on the Phase Measuring Profilometry with Parallel-optical-axes)

  • 정경민;박윤창;박경근
    • 한국정밀공학회지
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    • 제17권6호
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    • pp.210-217
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    • 2000
  • Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and it's high sensitivity. Especially when projecting a grid pattern over the object, the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, the projection moire are compared with the PMP mathematically, and it is shown that PMP can generate moire image with simple mathematical computations. Experimental works are also carried out showing the same results. It is shown that using a single gird pattern, moire image can be obtained directly without any mathematical operation when some conditions are satisfied.

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단일격자 이송을 이용한 영사식 3차원 물체 형상 측정에 관한 연구 (A Study on the measurement of 3-D Object with Single Grating Shiftings)

  • 박윤창;정경민
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 춘계학술대회 논문집
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    • pp.187-192
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    • 1999
  • Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially when projecting a grid pattern over the object, the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, the projection moire are compared with the PMP mathematically, and it is shown that PMP can generate moire image with simple mathematical computations. Experimental works are also carried out showing the same results. It is shown that using a single gird pattern, moire image can be obtained directly without any mathematical operation when some conditions are satisfied.

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냉각탑용 축류팬 형상 정밀도 측정 시스템 (Surface Profile Measuring System for Axial Fan of Cooling Towers)

  • 강재관;이광일
    • 한국정밀공학회지
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    • 제22권4호
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    • pp.151-158
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    • 2005
  • An important component of a cooling tower is an axial fan, and there happens distortion in its shape which brings significant loss of efficiency. In this paper, a surface profile measuring system for large size axial fan of cooling towers is developed. A laser sensor is used as a measuring device and aluminum profiles and stepping motors are engaged into the system as frame structure and driving devices respectively. The measuring data are compared to the design data to compute the distortion of the axial fans. Two types of errors, axial and twist errors, are used to represent the precision of axial fan distortion. Genetic algorithm is used to solve the optimization problem during computing the precision. Results are displayed three dimensionally in a solid-modeler as well as 2-D drawings to help users find it with ease.

도로면 측정 분석 시스템 개발 및 국내 도로면 특성평가 응용 연구 (Development of the Road Profiling System and Evaluation of Korean Roads Roughness Characteristics)

  • 손성효;허승진
    • 한국자동차공학회논문집
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    • 제11권3호
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    • pp.192-197
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    • 2003
  • The ‘AEIPR’(Accelerometer Established Inertial Profiling Reference) method has been applied to measure the road profile. The dynamic road profiling method using AEIPR has the advantages of cost effectiveness, measuring speed and relatively high reliability. However, it is required to improve the double integration algorithm to get the measurement results with the accuracy of hither level. In the first part of this paper, the effective double integration algorithm is suggested and the ‘Road Profiler’ software is developed on the basis of the algorithm. Road profiling tests are performed using the developed ‘Road Profiler’ system on the specially designed tracks for the durability tests and the various types of pubic roads. Test results are shown and evaluated by the international road evaluation indicies and classification.

피치가변격자를 이용한 자유곡선 형상측정에 관한 연구 (A Study on the Measurement of 3-D object, make use of grid fringe generator)

  • 박윤창;정경민;박경근;장석준
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.19-22
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    • 2000
  • Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially, when projecting a grid pattern over the object the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, new method for grid pattern generation system by polygonal mirror and Laser Diode. This system is applied the projection moire and the PMP.

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Partial Spectrum Detection and Super-Gaussian Window Function for Ultrahigh-resolution Spectral-domain Optical Coherence Tomography with a Linear-k Spectrometer

  • Hyun-Ji, Lee;Sang-Won, Lee
    • Current Optics and Photonics
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    • 제7권1호
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    • pp.73-82
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    • 2023
  • In this study, we demonstrate ultrahigh-resolution spectral-domain optical coherence tomography with a 200-kHz line rate using a superluminescent diode with a -3-dB bandwidth of 100 nm at 849 nm. To increase the line rate, a subset of the total number of camera pixels is used. In addition, a partial-spectrum detection method is used to obtain OCT images within an imaging depth of 2.1 mm while maintaining ultrahigh axial resolution. The partially detected spectrum has a flat-topped intensity profile, and side lobes occur after fast Fourier transformation. Consequently, we propose and apply the super-Gaussian window function as a new window function, to reduce the side lobes and obtain a result that is close to that of the axial-resolution condition with no window function applied. Upon application of the super-Gaussian window function, the result is close to the ultrahigh axial resolution of 4.2 ㎛ in air, corresponding to 3.1 ㎛ in tissue (n = 1.35).

성인 남자의 흡연상태에 따른 영양섭취, 혈압, 혈액 성상 및 지질패턴 비교연구 (Comparative Study on Nutrient Intakes, Blood Pressure and Serum Lipid Profile of Korean Adult Men According to Smoking Status)

  • 최미경;조혜경;승정자
    • 한국식품영양과학회지
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    • 제35권2호
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    • pp.164-170
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    • 2006
  • 본 연구에서는 흡연율이 높은 성인 남자에 있어 흡연상태에 따라 비흡연군(47명), 흡연군(58명), 흡연경험군(44명)으로 나눠 영양섭취와 혈압, 혈액 성상 및 지질패턴을 비교분석하였다. 전체대상자의 평균 연령, 신장, 체중, 체질량지수 각각 54.7세, 165.8 cm, 67.3 kg, $24.5\;kg/m^2$이었으며, 흡연 상태에 따른 세 군간 유의한 차이가 없었다. 1일 평균 에너지와 단백질 섭취량은 각각 1740.9 kcal와 59.69 g이었으며, 흡연군간 유의한 차이가 없었다. 엽산 섭취량은 비흡연군 $324.2{\mu}g$, 흡연군 $235.1{\mu}g$, 흡연경험군 $272.7{\mu}g$으로 흡연군이 유의하게 낮았으나, 콜레스테롤 섭취량은 비흡연군 175.6mg, 흡연군 232.5 mg, 흡연경험군 154.3 mg으로 흡연군이 유의하게 높았다. 1일 총 식품 섭취량은 비흡연군 1250.0 g, 흡연군 1180.1 g, 흡연경험군 1237.5 g으로 세 군간 유의한 차이가 없었다. 버섯류의 섭취량은 비흡연군 1.5g, 흡연군 0.4g, 흡연경험군 4.8 g으로 흡연군이 유의하게 낮은 반면, 난류의 섭취량은 세 군 각각 8.3 g, 17.8 g, 4.4 g으로 흡연군이 유의하게 높았다. 전체대상자의 적혈구수와 혈청 GOT, GPT는 각각 $4598.2\times1000/mm^2$, 27.3 U/L, 27.3 U/L이었으며 비흡연군, 흡연군, 흡연경험군간 유의한 차이가 없었다. 그러나 백혈구수, 헤마토크릿, 헤모글로빈 농도는 흡연군이 각각 $6727.7/mm^3,\;45.9\%$, 14.7g/dL로 비흡연군($4921.5/mm^3,\;43.4\%$, 13.9 g/dL)이나 흡연경험군($5845.4/mm^3,\;44.2\%$, 13.9 g/dL)보다 유의하게 높았다. 전체대상자의 평균 혈압은 128.3/75.5 mmHg이었으며, 혈청 콜레스테롤, 중성지방, HDL-콜레스테롤, LDL-콜레스테롤, 동맥경화지수는 각각 180.2 mg/dL, 160.8 mg/dL, 41.5 mg/dL, 106.5 mg/dL, 3.5로 흡연상태에 따른 세 군간 유의한 차이가 없었다. 그러나 흡연군의 중성지질 농도는 비흡연군보다 유의하게 높았다. 이상의 연구결과를 종합할 때 흡연자는 비흡연자보다 엽산 섭취가 낮고 콜레스테롤 섭취가 높았으며, 백혈구수, 헤마토크릿과 헤모글로빈, 중성지질 함량이 높게 나타나 흡연이 일부 영양소의 섭취와 혈액성상에 변화를 초래하는 것으로 보여진다. 또한 흡연경험자는 비흡연자와 영양소 섭취와 혈액성상에 유의한 차이를 보이지 않아 흡연으로 인한 일부 영양소 섭취와 혈액성상의 변화는 금연으로 인해 비흡연 상태로 회복되는 것으로 생각된다. 따라서 흡연자를 대상으로 한 금연 교육이 우선적으로 요구되며, 흡연으로 인한 영양섭취의 변화가 인체에 미치는 영향을 설명 할 수 있는 직접적이고 세부적인 연구를 통해 흡연자의 영양 문제점과 그에 따른 식사관리 방안이 마련되어야 할 것이다.

고경사 자유곡면 측정을 위한 파장변조 층밀리기 간섭계 (Wavelength Scanning Lateral Shearing Interferometer for Freeform Surface Measurement)

  • 이혁교;김영식;이주형;양호순;이윤우
    • 한국정밀공학회지
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    • 제31권3호
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    • pp.199-205
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    • 2014
  • We propose a new variant of lateral shearing interferometer with a tunable laser source that enables 3D surface profile measurements of freeform optics with high speed, high vertical resolution, large departure, and large field-of-view. We have verified the proposed technique by comparing our measurement result with that of an existing technique and measuring a representative sample of freeform optics. Moreover, we propose a new algorithm that is able to compensate the rotational inaccuracy.